Apparatus and method for accurately scanning a light beam across tracks of a recording medium

Abstract

A lens is accelerated on a coarse tracking carriage while enabling a lens position servo, which moves the carriage so that the lens returns to a neutral position on the carriage. After the beam spot becomes fast enough, the carriage is accelerated and decelerated until the beam spot arrives near a destination track; then, the lens is decelerated on the carriage to stop on the destination track. The method does not require a stop at each track which is to be crossed. In a second method, the carriage is first accelerated while the fine tracking servo is enabled to trace a start track. After the carriage becomes fast enough that eccentricity of the tracks will not prohibit a correct jump, the fine tracking servo is disabled. The beam spot is then moved by a lens lock force which returns the lens to the neutral position on the carriage. The carriage is further accelerated and decelerated, and then the lens is decelerated in the same manner as the first method.

What is claimed is: 
     
       1. A method of track jumping of a plurality of coaxial or spiral recording tracks on a recording medium of an optical recording apparatus, the recording medium having eccentric recording tracks, the optical apparatus having: fine tracking means for moving a light beam spot on the recording medium, along essentially radial directions of the tracks;   carriage means capable of moving along an essentially radial direction of the tracks, having the fine tracking means installed thereon, the fine tracking means movable on the carriage means over the tracks along essentially radial directions of the tracks and having a neutral position on the carriage means;   light detecting means for detecting a light reflected from the recording medium so as to generate a tracking error signal;   fine tracking control means capable of servo controlling the beam spot by moving the fine tracking means on the carriage means according to the tracking error signal for the beam spot to trace a particular one of the tracks;   carriage tracking control means for moving the carriage means; and   position servo means for keeping the fine tracking means at a neutral position on the carriage means by moving the carriage means according to a position signal, the position signal becoming zero when the fine tracking means is at the neutral position and becoming positive or negative when deviating from the neutral position to an inward direction or to an outward direction on the recording medium respectively, comprising the steps of: (a) accelerating the beam spot by accelerating the fine tracking means until a speed of the beam spot exceeds an absolute radial speed of the eccentric tracks, while the fine tracking servo control of the beam spot is disabled and the position servo means is kept enabled;   (b) further accelerating the beam spot by moving the carriage means;   (c) decelerating the beam spot by decelerating the carriage means until the speed of the beam spot reaches a predetermined speed below which the fine tracking control is possible;   (d) counting a number of zero crossings in the tracking error signal since the track jumping was initiated, whereby a track number where the beam spot is currently located is acquired; and   (e) decelerating the beam spot by decelerating the fine tracking means on the carriage means according to a difference of the counted number of crossed tracks and instructed number of track jumping to reach a destination track where the beam spot is to stop.     
     
     
       2. A method according to claim 1, wherein said step (a) further comprises the substeps of: (a1) measuring a time interval between zero-crossings in the tracking error signal, for each track crossing, while the beam spot is moving;   (a2) obtaining a time interval difference between the time interval of zero crossings and a first predetermined time interval which corresponds to a first predetermined speed faster than the absolute radial speed of the eccentric tracks; and   (a3) accelerating or decelerating the beam spot by accelerating/decelerating the fine tracking means according to the time interval difference so as to make the time interval of the zero-crossings essentially equal to the first predetermined time interval, without stopping the beam spot at each track.   
     
     
       3. A method according to claim 1, wherein said step (e) further comprises the sub-steps of: (e1) measuring a first time interval between zero-crossings in the tracking error signal, for each track crossing, while the beam spot is moving;   (e2) obtaining a time difference between the first time interval of zero-crossings and a second predetermined time interval; and   (e3) accelerating or decelerating the beam spot according to the time difference so as to make the time interval of the zero-crossings essentially equal to the second predetermined time interval, without stopping the beam spot at each track.   
     
     
       4. A method according to claim .[.2 or.]. 3, wherein said measuring substep utilizes a second time interval between zero-crossings in the tracking error signal determined by an interval of adjacent transitions of zero-crossings, the transitions being from one polarity to an opposite polarity, the zero-crossings being generated when the beam spot passes a centre of each track. 
     
     
       5. A method according to claim 3, further comprising the steps of: repeating said steps (a) through (c) with respectively renewed predetermined time interval and a renewed instructed track, the renewed predetermined time interval being longer than the previous predetermined time interval, the renewed instructed track being closer to the destination track than the previously instructed track.   
     
     
       6. A method according to claim 5, wherein said repeating step utilizes a fixed predetermined time interval which is chosen long enough, and a final instructed track which is chosen near enough to the destination track, for the beam spot to be able to stop surely at the destination track. 
     
     
       7. A method according to claim 1, wherein said step (c) is repeated until the beam spot arrives at a track whose track number is calculated by a program prepared in advance according to an instructed number of tracks to be jumped. 
     
     
       8. A method according to claim 7, wherein said step (c) is repeated for a number of tracks determined by a program to be approximately half of the instructed number of tracks to be jumped. 
     
     
       9. A method according to claim 1 .[.or 3.]., wherein said step (e) is carried out while the position servo means is enabled. 
     
     
       10. A method of track jumping of a plurality of coaxial or spiral recording tracks on a recording medium of an optical apparatus, the recording medium having eccentric tracks, the optical apparatus having: fine tracking means for moving a beam spot on the recording medium along essentially radial directions of the tracks;   carriage means capable of moving along an essentially radial direction of the tracks, having the fine tracking means installed thereon, the fine tracking means movable on the carriage means over the tracks along an essentially radial direction of the tracks, and having a neutral position on the carriage means;   .Iadd.position detection means for detecting a position of the fine tracking means with respect to the carriage means and for outputting a position signal;.Iaddend.   light detecting means for detecting a light reflected from the recording medium so as to generate a tracking error signal;   fine tracking control means capable of servo controlling the beam spot by moving the fine tracking means on the carriage means according to the tracking error signal for the beam spot to trace a particular one of the tracks; and   carriage tracking control means for moving the carriage means, comprising the steps of: (a) accelerating the carriage means while enabling the fine tracking control means for the beam spot which allows the beam spot to maintain its position at a start track at which the beam spot is located when the track jumping is instructed;   (b) disabling the fine tracking control means, when the position signal reaches a predetermined level, whereby the fine tracking means returns to the neutral position and the beam spot crosses the tracks;   (c) further accelerating the beam spot by further accelerating the carriage means until the beam spot reaches a predetermined track;   (d) decelerating the beam spot by decelerating the carriage means until a speed of the beam spot reaches a predetermined speed below which the fine tracking control is possible;   (e) counting a number of zero crossings in the tracking error signal since the track jumping was initiated, whereby the track number where the beam spot is currently located is acquired; and   (f) moving the beam spot by moving the fine tracking means on the carriage means according to a difference of the counted number of crossed tracks and an instructed number of track jumps so as to reach a destination track where the beam spot is to stop.     
     
     
       11. A method according to claim 10, wherein said step (f) further comprises the substeps of: (f1) measuring a time interval between zero-crossings in the tracking error signal, while the beam spot is moving, for each track;   (f2) obtaining a time interval difference between the time interval of zero-crossings and a first predetermined time interval; and   (f3) accelerating or decelerating the beam spot according to the time difference so as to make the time interval of the zero-crossings essentially equal to the first predetermined time interval, without stopping the beam spot at each track.   
     
     
       12. A method according to claim 11, wherein said measuring substep utilizes a second time interval between zero-crossings in the tracking error signal determined by an interval of adjacent transitions of zero-crossings, the transitions being from one polarity to an opposite polarity, the zero-crossings being generated when the beam spot passes a centre of each track. 
     
     
       13. A method according to claim 11, further comprising the steps of: repeating the steps (a) through (c) with respectively renewed predetermined time interval and a renewed instructed track, the renewed predetermined time interval being longer than the previous predetermined time interval, the renewed instructed track being closer to the destination track than the previous instructed track.   
     
     
       14. A method according to claim 13, wherein said repeating step utilizes a fixed predetermined time interval which is chosen long enough, and a final instructed track which is chosen near enough to the destination track, for the beam spot to be able to stop surely at the destination track. 
     
     
       15. A method according to claim 10, wherein said step (b) is continued until the beam spot arrives at a track whose track number is calculated by a program prepared in advance according to an instructed number of tracks to be jumped. 
     
     
       16. A method according to claim 15, wherein said step (c) is repeated for a number of tracks determined by a program to be approximately half of the instructed number of tracks to be jumped. 
     
     
       17. A method according to claim 10 .[.or 11.]., wherein said step (f) is carried out while the position servo means is enabled, the position servo means keeping the fine tracking means at a neutral position on the carriage means by moving the carriage means according to a position signal, the position signal becoming zero when the fine tracking means is at the neutral position on the carriage means and becoming positive or negative when deviating from the neutral position to one direction or to the opposite direction respectively. 
     
     
       18. A method of controlling track jumping of a plurality of recording tracks on a recording medium of an optical recording apparatus, the recording medium having eccentric tracks, the optical apparatus having: fine tracking means for moving a light beam spot on the recording medium along essentially radial directions of the tracks, the fine tracking means being movable on a carriage means and having a neutral position on the carriage means, and being capable of causing the beam spot to cross a track;   light detecting means for detecting a light reflected from the beam spot so as to generate a tracking error signal; and   fine tracking control means capable of servo controlling the beam spot by moving the fine tracking means on the carriage according to the tracking error signal which allows the beam spot to trace a particular one of the tracks, comprising the steps of: (a) measuring a time interval between .[.ero-crossings.]. .Iadd.zero-crossings .Iaddend.in the tracking error signal, for each track crossing, while the beam spot is crossing to each adjacent track;   (b) obtaining a time interval difference between the time interval of .[.ero-crossings.]. .Iadd.zero-crossings .Iaddend.and a first predetermined time interval; and   (c) accelerating or decelerating the beam spot by accelerating or decelerating the fine tracking means on the carriage according to the time difference, so as to make the time interval of the .[.ero-crossings.]. .Iadd.zero-crossings .Iaddend.essentially equal to the first predetermined time interval, without stopping the beam spot at each track.     
     
     
       19. A method according to claim 18, further comprising the substeps of: repeating steps (a) through (c) with the predetermined time interval renewed.   
     
     
       20. A method according to claim 18 .[.or 19.]., wherein said steps (a) through (c) are carried out while the carriage is stationarily fixed. 
     
     
       21. A method according to claim 18 .[.or 19.]., wherein said steps (a) through (c) are carried out while the position servo means is enabled, the position servo means keeping the fine tracking means at the neutral position of the carriage means by moving the carriage means according to a position signal, the position signal becoming zero when the fine tracking means is at the neutral position on the carriage means and becoming positive or negative when deviating from the neutral position to one direction or to the opposite direction respectively. 
     
     
       22. A method according to claim 18 .[.or 19.]., wherein said measuring step utilizes a time interval between zero-crossings in the tracking error signal measured by an interval of adjacent zero-crossings, the transition being from a first polarity to an opposite polarity, the zero-crossings being generated when the beam spot passes a centre of each track. 
     
     
       23. A method according to claim 18 .[.or 19.]., wherein said steps (b) and (c) utilize a fixed predetermined time interval which is chosen long enough, and a final instructed track which is chosen near enough to the destination track, for the fine tracking means to be able to stop surely at the destination track. 
     
     
       24. A method of changing a position of an optical beam having a beam spot relative to a plurality of tracks of a recording medium from a start track to a destination track, the recording medium having eccentric recording tracks, comprising the steps of: (a) accelerating the beam spot until .[.the.]. .Iadd.a .Iaddend.beam spot speed in a direction substantially perpendicular to the tracks exceeds an absolute radial speed of the eccentric recording tracks of the recording medium before a first track to be crossed is actually crossed;   (b) controlling the beam spot speed to maintain the beam spot speed at or below a first predetermined speed at which the beam spot can be stopped at a destination track;   (c) counting a number of .Iadd.the .Iaddend.tracks crossed since .[.the start of.]. said .Iadd.accelerating started in .Iaddend.step (a); and   (d) decelerating the beam spot based on a difference between the counted number of tracks crossed and a number of tracks to be crossed from the start track to the destination track while ensuring that the beam spot speed does not fall below the absolute radial speed of the eccentric tracks until a last track to be crossed is actually crossed.   
     
     
       25. A method according to claim 24, .[.wherein said step (b).]. further .[.comprises.]. .Iadd.comprising .Iaddend.the .[.substeps.]. .Iadd.steps .Iaddend.of: .[.(b1).]. (.Iadd.e) .Iaddend.measuring a time interval for a track crossing while the beam spot is moving;   .[.(b2).]. (.Iadd.f) .Iaddend.obtaining a .Iadd.first .Iaddend.time interval difference between the time interval for the track crossing and a first predetermined time interval which corresponds to a .[.second.]. predetermined speed faster than the absolute radial speed of the .[.eccentric.]. tracks; and   .[.(b3).]. (.Iadd.g) .Iaddend.accelerating or decelerating the beam spot .[.by accelerating or decelerating the beam spot.]. according to the time interval .[.so as.]. to make the time interval of the track crossings essentially equal to the first predetermined time interval without stopping the beam spot at each track.   
     
     
       26. A method according to claim 25, wherein said .[.substep (b1).]. .Iadd.measuring in step (e) .Iaddend.comprises measuring a second time interval corresponding to one-half of a track crossing, and   wherein said .[.substep (b2).]. .Iadd.obtaining in step (f) .Iaddend.comprises obtaining a second time interval difference between the second time interval corresponding to one-half of a track crossing and a second predetermined time interval.   
     
     
       27. A method according to claim 25, wherein said substep .[.(b1).]. (.Iadd.e) .Iaddend.comprises measuring a third time interval corresponding to one-quarter of a track crossing, and   wherein said substep .[.(b2).]. (.Iadd.f) .Iaddend.comprises obtaining a third time interval difference between the third time interval corresponding to one-quarter of a track crossing and a third predetermined time interval.   
     
     
       28. A method according to claim 24, .[.wherein said step (d).]. further .[.comprises.]. .Iadd.comprising .Iaddend.the .[.substeps.]. .Iadd.steps .Iaddend.of: .[.(d1).]. (.Iadd.e) .Iaddend.measuring a time interval of a track crossing while the beam spot is moving;   .[.(d2).]. (.Iadd.f) .Iaddend.obtaining a time interval difference between the time interval for the track crossing and a first predetermined time interval; and   .[.(d3).]. (.Iadd.g) .Iaddend.decelerating the beam spot according to the time interval difference .[.so as.]. to make the time interval of the track crossing essentially equal to the first predetermined time interval without stopping the beam spot at each track.   
     
     
       29. A method according to claim 28, wherein said .[.substep (d1).]. .Iadd.measuring in step (e) .Iaddend.comprises measuring a second time interval corresponding to one-half of a track crossing, and wherein said .[.substep (d2).]. .Iadd.obtaining in step (f) .Iaddend.comprises obtaining a second time interval difference between the second time interval corresponding to one-half of a track crossing and a second predetermined time interval.   
     
     
       30. A method according to claim 28, wherein said .[.substep (d1).]. .Iadd.measuring in step (e) .Iaddend.comprises measuring a .[.third.]. .Iadd.second .Iaddend.time interval corresponding to one-quarter of a track crossing, and   wherein said .[.substep (d2).]. .Iadd.obtaining in step (f) .Iaddend.comprises obtaining a .[.third.]. .Iadd.second .Iaddend.time interval difference between the .[.third.]. .Iadd.second .Iaddend.time interval corresponding to one-quarter of a track crossing and a .[.third.]. .Iadd.second .Iaddend.predetermined time interval.   
     
     
       31. A method according to claim 28, further comprising .[.the steps of:.]. repeating said .[.substeps (d1).]. .Iadd.measuring in step (e) .Iaddend.and .[.(d3).]. .Iadd.said decelerating in step (g) .Iaddend.with a renewed predetermined time interval. 
     
     
       32. A method according to claim 24, wherein said .Iadd.controlling in .Iaddend.step (b) is carried out until the beam spot reaches a predetermined track whose number is calculated by a program prepared in advance according to the number of tracks to be crossed from the start track to the destination track. 
     
     
       33. A method of changing a position of an optical beam having a beam spot .Iadd.moving at a beam spot speed .Iaddend.relative to a plurality of tracks of a recording medium from a start track to a destination track, the recording medium having eccentric recording tracks, comprising the steps of: (a) maintaining a position of the beam spot transmitted by a lens connected to a carriage, at a start track using a lens moving apparatus while the carriage is accelerated using a carriage moving apparatus until the carriage speed in a direction substantially perpendicular to the tracks is greater than or equal to a first predetermined speed;   (b) releasing the lens from maintaining the position at the start track so that the beam spot moves in the direction substantially perpendicular to the tracks;   (c) decelerating the beam spot transmitted by the lens connected to the carriage using at least one of the lens moving apparatus and the carriage moving apparatus until the beam spot speed reaches a second predetermined speed at or below which at least one of the carriage moving apparatus and the lens moving apparatus are operable to stop the beam spot at the destination track;   (d) counting a number of tracks crossed .Iadd.by the beam spot .Iaddend.since the .Iadd.beam spot left the .Iaddend.start .[.of said step (a).]. .Iadd.track.Iaddend.; and   (e) decelerating at least one of the carriage and the lens using at least one of the carriage moving apparatus and the lens moving apparatus, respectively, based on .[.the.]. .Iadd.a .Iaddend.difference between the .[.counted.]. number of tracks crossed and .[.the.]. .Iadd.a .Iaddend.number of tracks to be crossed from the start track to the destination track while ensuring that the beam spot speed does not fall below .[.the.]. .Iadd.an .Iaddend.absolute radial speed of .Iadd.the tracks caused by .Iaddend.the eccentric .Iadd.recording .Iaddend.tracks until the last track to be crossed is actually crossed. .Iadd.34. A method according to claim 2, wherein said measuring in substep (a1) utilizes a second time interval between zero-crossings in the tracking error signal determined by an interval of adjacent transitions of zero-crossings, the transition being from one polarity to an opposite polarity, the zero-crossings being generated when the beam spot passes a center of each track..Iaddend..Iadd.35. A method according to claim 3, wherein said decelerating in step (e) is carried out while the position servo means is enabled..Iaddend..Iadd.36. A method according to claim 11, wherein said moving in step (f) is carried out while position servo means is enabled, the position servo means keeping the fine tracking means at a neutral position on the carriage means by moving the carriage means according to a position signal, the position signal becoming zero when the fine tracking means is at the neutral position on the carriage means and becoming positive or negative when deviating from the neutral position to one direction or to the opposite direction, respectively..Iaddend..Iadd.37. A method according to claim 19, wherein said steps (a) through (c) are carried out while the carriage is stationarily fixed..Iaddend..Iadd.38. A method according to claim 19, wherein said steps (a) through (c) are carried out while position servo means is enabled, the position servo means keeping the fine tracking means at the neutral position of the carriage means by moving the carriage means according to a position signal, the position signal becoming zero when the fine tracking means is at the neutral position on the carriage means and becoming positive or negative when deviating from the neutral position to one direction or to the opposite direction, respectively..Iaddend..Iadd.39. A method according to claim 19, wherein said measuring in step (a) utilizes a time interval between zero-crossings in the tracking error signal measured by an interval or adjacent zero-crossings, the transition being from a first polarity to an opposite polarity, the zero-crossings being generated when the beam spot passes a center of each track..Iaddend..Iadd.40. A method according to claim 19, wherein said steps (b) and (c) utilize a fixed predetermined time interval which is chosen long enough, and a final instructed track which is chosen near enough to the destination track, for the fine tracking means to be able to stop surely at the destination track..Iaddend..Iadd.41. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage for moving the beam spot across the recording tracks of the recording disk medium, said movement control apparatus comprising:   fine tracking means, mounted on the carriage, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling the carriage; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means to accelerate the beam spot in a radial direction of the recording disk medium so that the beam spot speed exceeds an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks when the beam spot located on a start track is moved to a destination track..Iaddend..Iadd.42. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage for moving the beam spot across the recording tracks of the recording disk medium, said movement control apparatus comprising:   fine tracking means, mounted on the carriage, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling the carriage; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means to accelerate the beam spot using said fine tracking means to exceed an absolute radial speed of the recording track caused by an eccentricity of the recording disk medium and then further controlling said second control means to accelerate the beam spot using the carriage after the beam spot is accelerated by controlling   
     
     
        said first control means..Iaddend..Iadd.43.  A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage for moving the beam spot across the recording tracks of the recording disk medium, said movement control apparatus comprising: fine tracking means, mounted on the carriage, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling the carriage; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means and said second control means to decelerate the beam spot in a radial direction of the recording disk medium at a deceleration speed which exceeds an absolute radial speed of the recording tracks, after the beam spot is decelerated toward a destination track by the carriage and while the beam spot is further   
     
     
        approaching the destination track..Iaddend..Iadd.44.  A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage for moving the beam spot across the recording tracks of the recording disk medium, said movement control apparatus comprising: fine tracking means, mounted on the carriage, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling the carriage; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said second control means to decelerate the beam spot using said carriage means, and then controlling said first control means to further decelerate the beam spot using said fine tracking means before the beam spot speed is decelerated by the carriage to less than an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks..Iaddend..Iadd.45. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage for moving the beam spot across the recording tracks of the recording disk medium, said movement control apparatus comprising:   fine tracking means, mounted on the carriage, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling the carriage; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means to decelerate the beam spot using said fine tracking means, while the beam spot is decelerated by the carriage and before the beam spot speed is decelerated by the carriage to less than an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk medium. .Iadd.46. A movement control apparatus according to claim 45,   wherein said third control means includes speed determination means for determining whether the beam spot speed has fallen below a predetermined speed, and   wherein said third control means controls said first control means to start deceleration of the beam spot by said fine tracking means after said speed determination means determines that the beam spot speed has fallen below   
     
     
        the predetermined speed..Iaddend..Iadd.47.  A movement control apparatus according to claim 46, wherein the predetermined speed is an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks..Iaddend..Iadd.48. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage for moving the beam spot across the recording tracks of the recording disk medium, said movement control apparatus comprising: fine tracking means, mounted on the carriage, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling the carriage;   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means to decelerate the beam spot using said fine tracking means after the beam spot is decelerated by the carriage and before the beam spot speed is decelerated by the carriage to less than an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk medium; and   detection means for detecting a displacement of said fine tracking means from a neutral position of said fine tracking means on the carriage, said second control means controlling the carriage to reduce the displacement of said fine tracking means..Iaddend..Iadd.49. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage for moving the beam spot across the recording tracks of the recording disk medium, said movement control apparatus comprising:   fine tracking means, mounted on the carriage, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling the carriage; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means and said second control means before the beam spot jumps from a start track to a destination track, by accelerating the carriage while the beam spot is maintained at the start   
     
     
        track by said fine tracking means..Iaddend..Iadd.50.  A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage for moving the beam spot across the recording tracks of the recording disk medium, said movement control apparatus comprising: fine tracking means, mounted on the carriage, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling the carriage; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means and said second control means to cause the beam spot to jump from a start track to a destination track by accelerating the carriage until the carriage speed in a direction substantially perpendicular to the recording tracks is at least as fast as a first predetermined speed, while the beam spot is maintained at the start track by said fine tracking means, and then releasing the beam spot from the start track after accelerating the carriage, so that the beam spot moves in the direction substantially perpendicular to the recording tracks..Iaddend..Iadd.51. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, comprising:   fine tracking means for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for measuring a time interval between zero crossings in the tracking error signal;   first control means for controlling said fine tracking means; and   second control means for controlling said first control means based upon the time interval to accelerate and decelerate the beam spot by said fine   
     
     
        tracking means..Iaddend..Iadd.52.  A movement control apparatus according to claim 51, wherein the optical disk apparatus includes a carriage for moving the beam spot across the recording tracks of the recording disk medium, said fine tracking means mounted on the carriage, and wherein said movement control apparatus further comprises third control means for controlling the carriage, said third control means controlled by said second control means to accelerate and decelerate the beam spot based upon the time interval..Iaddend..Iadd.53. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage movable across the recording tracks of the recording disk medium, a first motor coupled to move the carriage, an objective lens movably mounted on the carriage, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks and a second motor coupled to move the objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of the carriage, said movement control apparatus comprising:   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal; and   a processor, operatively connected to said circuit, said counter and the first and second motors, controlling movement of the beam spot from a current recording track to a target recording track by outputting a first acceleration signal to the first motor starting when the beam spot is on the current recording track and continuing until the beam spot speed exceeds an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks, and then outputting a second acceleration signal to the first motor..Iaddend..Iadd.54. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage movable across the recording tracks of the recording disk medium, a first motor coupled to move the carriage, an objective lens movably mounted on the carriage, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks and a second motor coupled to move the objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of the carriage, said movement control apparatus comprising:   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal; and   a processor, operatively connected to said circuit, said counter and the first and second motors, controlling movement of the beam spot by outputting a first acceleration signal to the second motor to accelerate the beam spot and to output a second acceleration signal to the first motor after the beam spot speed increases due to the second motor beyond an absolute radial speed of the recording tracks caused by an eccentricity   
     
     
        of the recording tracks..Iaddend..Iadd.55.  A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage movable across the recording tracks of the recording disk medium, a first motor coupled to move the carriage, an objective lens movably mounted on the carriage, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks and a second motor coupled to move the objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of the carriage, said movement control apparatus comprising: a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal; and   a processor, operatively connected to said circuit, said counter and the first and second motors, controlling movement of the beam spot by outputting a deceleration signal to the second motor to produce a deceleration speed exceeding an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks, after the beam spot is decelerated toward a destination track by the carriage and when the beam spot is approaching a destination track..Iaddend..Iadd.56. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage movable across the recording tracks of the recording disk medium, a first motor coupled to move the carriage, an objective lens movably mounted on the carriage, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks and a second motor coupled to move the objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of the carriage, said movement control apparatus comprising:   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   a processor, operatively connected to said circuit, said counter and the first and second motors, controlling movement of the beam spot when the beam spot approaches a target track by outputting a first deceleration signal to the first motor, and a second deceleration signal to the second motor before the beam spot speed is decelerated by the first motor below an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks..Iaddend..Iadd.57. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage movable across the recording tracks of the recording disk medium, a first motor coupled to move the carriage, an objective lens movably mounted on the carriage, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks and a second motor coupled to move the objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of the carriage, said movement control apparatus comprising:   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   a processor, operatively connected to said circuit, said counter and the first and second motors, controlling movement of the beam spot by outputting deceleration signals to the first and second motors to decelerate the beam spot by the second motor while the beam spot speed being decelerated by the first motor before the beam spot speed is decelerated by the carriage to less than an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks..Iaddend..Iadd.58. An optical disk apparatus comprising:   a carriage movable across a plurality of recording tracks of a recording disk medium;   a first motor which moves said carriage;   an objective lens movable on said carriage means along a radial direction of the recording disk medium, said objective lens impinges a beam spot onto a recording track;   a second motor which moves said objective lens along a radial direction of the recording disk medium;   a circuit which detects a misregistration of the beam spot from a recording track in a radial direction of the recording disk medium, said circuit outputs a tracking error signal;   a counter, operatively connected to said circuit, which counts a number of tracks which the beam spot has crossed, based upon the tracking error signal;   a processor, operatively connected to said circuit, said counter and said first and second motors, controlling movement of the beam spot by outputting a first deceleration signal to said first motor to decelerate the beam spot and then outputting a second deceleration signal to said second motor to decelerate the beam spot by said second motor after the beam spot is decelerated by said first motor and before the beam spot is decelerated by the carriage to less than an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk medium; and   detection means for detecting a displacement of said objective lens from a neutral position of said objective lens on the carriage, said processor controlling the carriage to reduce the displacement of the objective lens in dependence upon the displacement detected by said detection means..Iaddend..Iadd.59. A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including a carriage movable across the recording tracks of the recording disk medium, a first motor coupled to move the carriage, an objective lens movably mounted on the carriage, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks and a second motor coupled to move the objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of the carriage, said movement control apparatus comprising:   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   a processor, operatively connected to said circuit, said counter and the first and second motors, controlling movement of the beam spot before the beam spot jumps from a start track to a destination track, by outputting an acceleration signal to the first motor to accelerate toward the destination track, and outputting a track following signal to the second motor to maintain the beam spot at the start track while the carriage is   
     
     
        accelerated by the first motor..Iaddend..Iadd.60.  A movement control apparatus in an optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks, the optical disk apparatus including an objective lens, movable along a radial direction of the recording disk medium, focusing the beam spot onto one of the recording tracks, and a first motor coupled to move the objective lens along the radial direction of the recording disk medium, said movement control apparatus comprising: a circuit to output a tracking error signal indicating a misregistration of the beam spot from one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal; and   a processor, operatively connected to said circuit, said counter and the first motor, to measure a time interval between zero-crossing signals of the tracking error signal and to output at least one of a first acceleration signal and a first deceleration signal to the first motor based upon the time interval..Iaddend..Iadd.61. A movement control apparatus according to claim 60, wherein the optical disk apparatus includes a carriage movable across the recording tracks of the recording disk medium, the objective lens mounted on the carriage and a second motor operatively connected to said processor and coupled to move the carriage..Iaddend..Iadd.62. A movement control apparatus according to claim 61,   wherein said processor outputs at least one of a second acceleration signal and a second deceleration signal to the second motor based upon the time interval..Iaddend..Iadd.63. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   carriage means for moving the beam spot across the recording tracks of the recording disk medium;   fine tracking means, mounted on said carriage means, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling said carriage means; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means to accelerate the beam spot in a radial direction of the recording disk medium so that the beam spot speed exceeds an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks when the beam spot located on a   
     
     
        start track is moved to a destination track..Iaddend..Iadd.64.  An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising: carriage means for moving the beam spot across the recording tracks of the recording disk medium;   fine tracking means, mounted on said carriage means, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling said carriage means; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means to accelerate the beam spot using said fine tracking means to exceed an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk medium and then further controlling said second control means to accelerate the beam spot using said carriage means after the beam spot is accelerated by said fine track means to more than an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks..Iaddend..Iadd.65. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   carriage means for moving the beam spot across the recording tracks of the recording disk medium;   fine tracking means, mounted on said carriage means, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling said carriage means; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling of said first control means and said second control means to decelerate the beam spot in a radial direction of the recording disk medium at a deceleration speed which exceeds an absolute radial speed of the recording tracks, after the beam spot is decelerated toward a destination track by said carriage means and while the beam spot is   
     
     
        approaching the destination track..Iaddend..Iadd.66.  An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising: carriage means for moving the beam spot across the recording tracks of the recording disk medium;   fine tracking means, mounted on said carriage means, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling said carriage means; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said second control means to decelerate the beam spot using said carriage means, and then controlling said first control means to further decelerate the beam spot using said fine tracking means before the beam spot speed is decelerated by said carriage means to less than an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks..Iaddend..Iadd.67. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   carriage means for moving the beam spot across the recording tracks of the recording disk medium;   fine tracking means, mounted on said carriage means, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling said carriage means; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means to decelerate the beam spot using said fine tracking means at a beam spot speed greater than an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk medium while the beam spot is decelerated by said   
     
     
        carriage means..Iaddend..Iadd.68.  An optical disk apparatus according to claim 67, wherein said third control means includes speed determination means for determining whether the beam spot speed has fallen below a predetermined speed, and   wherein said third control means controls said first control means to start deceleration of the beam spot by said fine tracking means after said speed determination means determines that the beam spot speed has fallen below the predetermined speed..Iaddend..Iadd.69. An optical disk apparatus according to claim 68,   wherein the predetermined speed is an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks..Iaddend..Iadd.70. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   carriage means for moving the beam spot across the recording tracks of the recording disk medium;   fine tracking means, mounted on said carriage means, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling said carriage means; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means to decelerate the beam spot using said fine tracking means while the beam spot is decelerated by said carriage means before the beam spot is decelerated by said carriage means to less than an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk medium..Iaddend..Iadd.71. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   carriage means for moving the beam spot across the recording tracks of the recording disk medium;   fine tracking means, mounted on said carriage means, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling said carriage means; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means and said second control means before the beam spot jumps from a start track to a destination track, by accelerating said carriage means while the beam spot is maintained at the start track by said fine tracking means..Iaddend..Iadd.72. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   carriage means for moving the beam spot across the recording tracks of the recording disk medium;   fine tracking means, mounted on said carriage means, for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   first control means for controlling said fine tracking means;   second control means for controlling said carriage means; and   third control means for controlling said first and second control means based upon the number of the recording tracks crossed, said third control means controlling said first control means and said second control means to cause the beam spot to jump from a start track to a destination track by accelerating said carriage means while the beam spot is maintained at the start track by said fine tracking means, and then releasing the beam spot from the start track so that the beam spot moves in the direction substantially perpendicular to the recording tracks at a beam spot speed at least as fast as a predetermined speed in a direction substantially   
     
     
        perpendicular to the recording tracks..Iaddend..Iadd.73.  An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising: fine tracking means for moving the beam spot across the recording tracks of the recording disk medium;   means for generating a tracking error signal representative of a displacement of the beam spot in a radial direction of the recording disk medium from one of the recording tracks;   means for obtaining a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   means for measuring a time interval between zero crossings in the tracking error signal;   first control means for controlling said fine tracking means; and   second control means for controlling said first control means based upon the time interval to accelerate and decelerate the beam   
     
     
        spot..Iaddend..Iadd.74.  An optical disk apparatus according to claim 73, further comprising: carriage means for moving the beam spot across the recording tracks of the recording disk medium, said fine tracking means mounted on said carriage means; and   third control means for controlling said carriage means, said third control means controlled by said second control means to accelerate and decelerate the beam spot based upon the time interval..Iaddend..Iadd.75. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   a carriage movable across the recording tracks of the recording disk medium;   a first motor coupled to move said carriage;   an objective lens movably mounted on said carriage means, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks;   a second motor coupled to move said objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of said carriage;   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal; and   a processor, operatively connected to said circuit, said counter and said first and second motors, controlling movement of the beam spot from a current recording track to a target recording track by outputting a first acceleration signal to said first motor starting when the beam spot is on the current recording track and continuing until the beam spot speed exceeds an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks, and then outputting a second   
     
     
        acceleration signal to said first motor..Iaddend..Iadd.76.  An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising: a carriage movable across the recording tracks of the recording disk medium;   a first motor coupled to move said carriage;   an objective lens movably mounted on said carriage means, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks;   a second motor coupled to move said objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of said carriage;   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal; and   a processor, operatively connected to said circuit, said counter and said first and second motors, controlling movement of the beam spot by outputting a first acceleration signal to said second motor to accelerate the beam spot beyond an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk medium and to then output a second acceleration signal to said first motor..Iaddend..Iadd.77. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   a carriage movable across the recording tracks of the recording disk medium;   a first motor coupled to move said carriage;   an objective lens movably mounted on said carriage means, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks;   a second motor coupled to move said objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of said carriage;   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal; and   a processor, operatively connected to said circuit, said counter and said first and second motors, controlling movement of the beam spot by outputting a deceleration signal to said second motor to produce a deceleration speed exceeding an absolute radial speed of the recording tracks caused by an eccentricity of the recording tracks, after the beam spot is decelerated toward a destination track by said carriage and when   
     
     
        the beam spot is approaching the destination track..Iaddend..Iadd.78.  An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising: a carriage movable across the recording tracks of the recording disk medium;   a first motor coupled to move said carriage;   an objective lens movably mounted on said carriage means, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks;   a second motor coupled to move said objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of said carriage;   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   a processor, operatively connected to said circuit, said counter and said first and second motors, controlling said first motor to decelerate the beam spot when the beam spot approaches a target track by outputting a first deceleration signal to said first motor, and further controlling said second motor to further decelerate the beam spot by outputting a second deceleration signal to said second motor before the beam spot speed is decelerated by said first motor below an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk medium..Iaddend..Iadd.79. An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising:   a carriage movable across the recording tracks of the recording disk medium;   a first motor coupled to move said carriage;   an objective lens movably mounted on said carriage means, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks;   a second motor coupled to move said objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of said carriage;   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   a processor, operatively connected to said circuit, said counter and said first and second motors, controlling movement of the beam spot by outputting deceleration signals to said first and second motors to decelerate the beam spot by said second motor while the beam spot speed being decelerated by said first motor and before the beam spot is decelerated by said carriage to less than an absolute radial speed of the recording tracks caused by an eccentricity of the recording disk   
     
     
        medium..Iaddend..Iadd.80.  An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising: a carriage movable across the recording tracks of the recording disk medium;   a first motor coupled to move said carriage;   an objective lens movably mounted on said carriage means, movable along a radial direction of the recording disk medium, focussing the beam spot onto one of the recording tracks;   a second motor coupled to move said objective lens along the radial direction of the recording disk medium to cause the beam spot to move at a beam spot speed in conjunction with movement of said carriage;   a circuit to output a tracking error signal indicating misregistration of the beam spot from the one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal;   a processor, operatively connected to said circuit, said counter and said first and second motors, controlling movement of the beam spot, before the beam spot jumps from a start track to a destination track, by outputting an acceleration signal to said first motor to accelerate toward the destination track, and outputting a track following signal to said second motor to maintain the beam spot at the start track while said carriage is   
     
     
        accelerated by said first motor..Iaddend..Iadd.81.  An optical disk apparatus directing a beam spot onto a recording disk medium having a plurality of recording tracks to access data on the recording disk medium, said optical disk apparatus comprising: an objective lens, movable along a radial direction of the recording disk medium, focusing the beam spot onto one of the recording tracks;   a first motor coupled to move said objective lens along the radial direction of the recording disk medium;   a circuit to output a tracking error signal indicating a misregistration of the beam spot from one of the recording tracks in a radial direction of the recording disk medium;   a counter, operatively connected to said circuit, to count a number of the recording tracks crossed by the beam spot, based upon the tracking error signal; and   a processor, operatively connected to said circuit, said counter and said first motor, to measure a time interval between zero-crossing signals of the tracking error signal and to output at least one of a first acceleration signal and a first deceleration signal to said first motor   
     
     
        based upon the time interval..Iaddend..Iadd.82.  An optical disk apparatus according to claim 81, further comprising: a carriage movable across the recording tracks of the recording disk medium, said objective lens mounted on said carriage; and   a second motor operatively connected to said processor and coupled to move said carriage..Iaddend..Iadd.83. An optical disk apparatus according to claim 82,   wherein said processor outputs at least one of a second acceleration signal and a second deceleration signal to said second motor based upon the time interval..Iaddend..Iadd.84. A method of changing a position of an optical beam having a beam spot relative to a plurality of tracks of a recording medium from a start track to a destination track, comprising the steps of:   (a) accelerating the beam spot until a beam spot speed in a direction substantially perpendicular to the tracks exceeds an absolute radial speed of the tracks of the recording medium, caused by an eccentricity of the tracks, before a first track to be crossed is actually crossed;   (b) continuing to move the beam spot after said accelerating in step (a) ends; and   (c) obtaining a number of the tracks crossed since said accelerating   
     
     
        started in step (a)..Iaddend..Iadd.85.  A method according to claim 84, further comprising the steps of: (d) measuring a time interval for a track crossing while the beam spot is moving;   (e) obtaining a first time interval difference between the time interval for the track crossing and a first predetermined time interval which corresponds to a predetermined speed faster than the absolute radial speed of the tracks; and   (f) accelerating or decelerating the beam spot according to the time interval to make the time interval of the track crossings essentially equal to the first predetermined time interval without stopping the beam spot at each track..Iaddend..Iadd.86. A method according to claim 85,   wherein said measuring in step (d) comprises measuring a second time interval corresponding to one-half of a track crossing, and   wherein said obtaining in step (e) comprises obtaining a second time interval difference between the second time interval corresponding to one-half of a track crossing and a second predetermined time interval..Iaddend..Iadd.87. A method according to claim 85,   wherein said measuring in step (d) comprises measuring a second time interval corresponding to one-quarter of a track crossing, and   wherein said obtaining in step (e) comprises obtaining a second time interval difference between the second time interval corresponding to one-quarter of a track crossing and a second predetermined time interval..Iaddend..Iadd.88. A method according to claim 84, further comprising the steps of:   (d) measuring a time interval of a track crossing while the beam spot is moving;   (e) obtaining a time interval difference between the time interval for the track crossing and a first predetermined time interval; and   (f) decelerating the beam spot according to the time interval difference to make the time interval of the track crossing essentially equal to the first predetermined time interval without stopping the beam spot at each   
     
     
        track..Iaddend..Iadd.89.  A method according to claim 88, wherein said measuring in step (d) comprises measuring a second time interval corresponding to one-half of a track crossing, and   wherein said obtaining in step (e) comprises obtaining a second time interval difference between the second time interval corresponding to one-half of a track crossing and a second predetermined time interval..Iaddend..Iadd.90. A method according to claim 88,   wherein said measuring in step (d) comprises measuring a second time interval corresponding to one-quarter of a track crossing, and   wherein said obtaining in step (e) comprises obtaining a second time interval difference between the second time interval corresponding to one-quarter of a track crossing and a second predetermined time interval..Iaddend..Iadd.91. A method according to claim 88, further comprising repeating said measuring in step (d) and said decelerating in step (f) with a renewed predetermined time interval..Iaddend..Iadd.92. A method according to claim 84, further comprising the step of (d) controlling the beam spot speed to maintain the beam spot speed no greater than a predetermined speed at which the beam spot can be stopped at the destination track, until the beam spot reaches a predetermined track whose number is calculated by a program prepared in advance according to the number of tracks to be crossed from the start track to the destination track..Iaddend..Iadd.93. A method of stopping an optical beam having a beam spot moving at a beam spot speed relative to a plurality of tracks of a recording medium from a start track to a destination track, comprising the steps of:   (a) decelerating the beam spot transmitted by a lens connected to a carriage using at least one of a lens moving apparatus and a carriage moving apparatus until the beam spot speed reaches a predetermined speed at or below which at least one of the carriage moving apparatus and the lens moving apparatus are operable to stop the beam spot at the destination track;   (b) obtaining a number of tracks crossed by the beam spot since the beam spot left the start track; and   (c) decelerating at least one of the carriage and the lens using at least one of the carriage moving apparatus and the lens moving apparatus, respectively, based on a difference between the number of tracks crossed and a number of tracks to be crossed from the start track to the destination track while ensuring that the beam spot speed does not fall below an absolute radial speed of the tracks caused by an eccentricity of the recording medium until the last track to be crossed is actually crossed..Iaddend..Iadd.94. A method according to claim 93, further comprising the following steps performed prior to steps (a)-(c):   (d) maintaining a position of the beam spot transmitted by the lens, at a start track using the lens moving apparatus while the carriage is accelerated using the carriage moving apparatus until a carriage speed in a direction substantially perpendicular to the tracks is greater than or equal to a second predetermined speed; and   (e) releasing the lens from the position at the start track maintained in step (d) so that the beam spot moves in the direction substantially perpendicular to the tracks..Iaddend.