Optical scanning device comprising a bent actuator coil

Abstract

The invention relates to an optical scanning device ( 17 ) for scanning an information track which is present on an information carrier ( 9 ). The scanning device comprises a radiation source ( 31 ), a lens system ( 43 ) with an optical axis ( 45 ) for focusing a radiation beam ( 47 ) supplied by the radiation source into a scanning spot ( 55 ) on the information carrier, and a focusing actuator ( 65 ) for displacing the lens system relatively to a basic part ( 29 ) of the scanning device in a direction parallel to the optical axis. The actuator comprises an electric coil ( 69 ) which is arranged around the lens system and provided with a passage ( 95 ) for a radiation beam path ( 49 ) which extends in a direction perpendicular to the optical axis. According to the invention, the electric coil is provided around the lens system by means of a winding process, the passage being provided in the coil by bending the parts ( 97 ) of the coil wires which are present near the radiation beam path, in a direction substantially parallel to the optical axis. In a preferred embodiment, said parts of the coil wires are bent during the winding process by means of a mandrel which is present in the passage during the winding process. In this manner, the optical scanning device according to the invention can be manufactured in a simple manner by means of a reduced number of process steps. The optical scanning device according to the invention can be used in an optical disc player according to the invention.

1 - 6 . (canceled)  
     
     
         7 . An optical scanning device comprising: 
 an optical lens system with an optical axis for focusing a radiation beam into a scanning spot; and    an actuator for displacing the lens system relative to a layer of an information carrier in a direction parallel to the optical axis to position the spot on the information carrier layer, the actuator including an electric coil arranged around the optical axis, the coil being a continuous series of wire portions interconnected by bends around bend axis that are substantially parallel to the optical axis, the wire portions including:    wire portions extending linearly substantially perpendicular to the optical axis; and    further wire portions with bends about axis being substantially perpendicular to the optical axis to form a passage through the coil for a path of the radiation beam, the path extending substantially perpendicular to the optical axis.    
     
     
         8 . An optical scanning device comprising: 
 an optical lens system with an optical axis for focusing a radiation beam into a scanning spot; and    an actuator for displacing the lens system relative to a layer of an information carrier in a direction parallel to the optical axis to position the spot on the information carrier layer, the actuator including an electric coil arranged around the optical axis, the coil comprising wiring that all extends substantially perpendicular to the optical axis except for a single local bend around a path for the radiation beam.    
     
     
         9 . An optical scanning device comprising: 
 an optical lens system with an optical axis for focusing a radiation beam into a scanning spot;    an actuator for displacing the lens system relative to a layer of an information carrier in a direction substantially parallel to the optical axis to position the spot on the information carrier layer, the actuator including an electric coil arranged around the optical axis, the electric coil being a continuous series of wire portions interconnected by bends, the wire portions having width and longitudinal direction that define a respective plane containing each respective wire portions, each wire portion defining a substantially different plane, the wire portions that define three of the planes extend linearly and substantially perpendicular to the optical axis and the wire portions in one of the planes that are bent to form a passage through the coil for a path of the radiation beam, the path extending substantially perpendicular to the optical axis.    
     
     
         10 . An optical scanning device comprising: 
 an optical lens system with an optical axis for focusing a radiation beam into a scanning spot;    an actuator for displacing the lens system relative to a layer of an information carrier in a direction parallel to the optical axis to position the spot on the information carrier layer, the actuator including an electric coil arranged around the optical axis, the coil being a continuous series of wire portions interconnected by bends, the wire portions having width and generally longitudinal directions that define respective planes containing the wire portions, each plane having one direction that is substantially parallel to the optical axis; and    one of the wire portions having bends to provide a passage through the coil for a path of the radiation beam, the path extending substantially perpendicular to the optical axis.    
     
     
         11 . An optical scanning device comprising: 
 an optical lens system with an optical axis for focusing a radiation beam into a scanning spot;    an actuator for displacing the lens system relative to a layer of an information carrier in a direction parallel to the optical axis to position the spot on the information carrier layer, the actuator including an electric coil arranged around the optical axis, the coil being a continuous series of wire portions interconnected by bends, the wire portions having a widths and generally longitudinal directions that define respective planes containing the wire portions, the wire portions including wire portions that extend perpendicular to the optical axis linearly between bends and a wiring portion that includes first parts that extend perpendicular to the optical axis and other parts that are transverse to the first parts to form a local passage through the coil for a path of the radiation beam, the path extending substantially perpendicular to the optical axis.    
     
     
         12 . An optical scanning device comprising: 
 an optical lens system with an optical axis for focusing a radiation beam into a scanning spot;    an actuator for displacing the lens system relative to a layer of an information carrier in a direction parallel to the optical axis to position the spot on the information carrier layer, the actuator including an electric coil arranged around the optical axis, the coil being a continuous series of wire portions interconnected by bends, the wire portions including portions that extend linearly between bends and a wiring portion that includes a local displacement around the radiation beam to form a passage through the coil for a path of the radiation beam, the direction of the displacement being substantially parallel to the optical axis, the path extending substantially perpendicular to the optical axis.    
     
     
         13 . An optical scanning device comprising: 
 an optical lens system with an optical axis for focusing a radiation beam into a scanning spot;    a first actuator for displacing the lens system relative to a layer of an information carrier in a direction parallel to the optical axis to position the spot on the information carrier layer, the actuator including a first electric coil arranged around the optical axis, the first coil including: a continuous series of wire portions interconnected by bends having axis parallel to the optical axis, the wire portions including linear portions and one bent portion that is bent to form a passage through the first coil for a path for the radiation beam, the path extending substantially perpendicular to the optical axis; and    a second actuator for displacing the lens system relative to tracks of the information carrier layer in a direction perpendicular to the optical axis to position the spot on a track of the layer, the second actuator including a second coil and a third coil being linear portions of wire interconnected by bends that are perpendicular to the optical axis, the second and third coils of the second actuator extending over respective portions of the first coil of the first actuator.    
     
     
         14 . An optical scanning device comprising: 
 a basic part;    an optical lens system with an optical axis for focusing a radiation beam into a scanning spot;    a holder for the lens system;    an actuator for displacing the lens system relative to the basic part in a direction parallel to the optical axis to position the spot on the information carrier layer, the actuator including an electric coil wound around the holder about the optical axis, the coil extending around the optical axis, the coil being a continuous series of wire portions interconnected by bends having bend axis parallel to the optical axis, the wire portions defining planes having a direction parallel to the optical axis, the wire portions include linear portions extending linearly between the bends and a bent wire portion that bends around the radiation beam to form a passage through the coil for a path of the radiation beam, the path extending substantially perpendicular to the optical axis;    and wherein the basic part is connected to the holder by spring bars, at least two of the spring bars being connected to the coil to energize the coil.    
     
     
         15 . A method for producing a scanning device, the method comprising: 
 providing a holder for an optical lens system having an optical axis for focusing a radiation beam into a scanning spot on a layer of an information carrier;    winding wire about the holder to form a first coil around the optical axis;    bending a part of the wire of the first coil in a direction parallel to the optical axis to provide a passage for a path of the radiation beam, the wiring of the first coil extending substantially perpendicular to the optical axis except around the passage.    
     
     
         16 . The method of  claim 15  further comprising winding wire around the holder over the first coil to form a second and a third coil, the second and third coils being on opposite respective sides of the optical axis, the second and third coils each having wire portions that extend over the first coil, the first coil being electrically insulated from the second and third coils.  
     
     
         17 . The method of  claim 15  in which the part of the wire is bent around the passage by a mandrill inserted into the passage as the wire is wound to form the first coil.  
     
     
         18 . The method of  claim 15  in which the part of the wire is bent around the passage after the wire is wound to form the first coil.  
     
     
         19 . The method of  claim 15  further comprising attaching the optical system to the holder.  
     
     
         20 . The method of  claim 15  further comprising: 
 providing a basic part of the scanning device, the basic part including a mirror positioned to deflect the radiation beam between the direction of the path and the direction of the optical axis; and  
 connecting the holder to the basic part using spring bars, the spring bars being connected to energize the first coil and energize the second and third coils independently from energizing the first coil.  
 
     
     
         21 . A scanning device produced by the method of  claim 15 .  
     
     
         22 . An optical recorder and/or player comprising: 
 a table for holding an optical information carrier, the table being rotatable about an axis of rotation to rotate the information carrier;    an optical scanning device;    a displacement device for moving the scanning device in the radial direction with respect to the axis of rotation;    and wherein the scanning device includes:    a basic part connected to the displacement device;    an optical lens system with an optical axis for focusing a radiation beam into a scanning spot;    an actuator for displacing the lens system relative to the basic part in a direction parallel to the optical axis to position the spot on the information carrier layer, the actuator including an electric coil arranged around the optical axis, the coil being a continuous series of wire portions interconnected by bends around axis that are substantially parallel to the optical axis, the wire portions including portions extending linearly and substantially perpendicular to the optical axis, and a wire portion that is bent to form a passage through the coil for a path of the radiation beam, the path extending substantially perpendicular to the optical axis.    
     
     
         23 . A holder for an optical lens system, comprising: 
 a frame for attaching the lens system, the lens system having an optical axis, the frame having an opening for the optical axis;    an actuator for displacing the lens system relative to a layer of an information carrier in a direction parallel to the optical axis to position the spot on the layer, the actuator including an electric coil wound about the frame and around the optical axis, the coil being a continuous series of wire portions interconnected by bends around axis that are parallel to the optical axis, the wire portions including linear portions and a bent portion forming a passage through the coil for a path of the radiation beam, the path extending substantially perpendicular to the optical axis.    
     
     
         24 . The scanning device of  claim 7  wherein: 
 all the wire portions of the coil extend substantially perpendicular to the optical axis except at the passage through the coil;  
 all the bends of the coil between the wire portions are about axis that are substantially parallel to the optical axis except at the passage through the coil;  
 the wire portions having width and longitudinal directions that define respective planes containing the wire portions;  
 each wire portion defines a different plane;  
 each plane has one direction that is substantially parallel to the optical axis;  
 the passage is a displacement in at least a part of one of the wire portions, the displacement being in a direction in the plane of the wire portion;  
 the passage is a local displacement of only a part of one of the wire portions, the displacement bending around the radiation beam, the direction of the displacement being substantially parallel to the optical axis;  
 the scanning device further comprising a second actuator for displacing the lens system relative to tracks of the information carrier layer in a direction perpendicular to the optical axis to position the spot on a track of the layer, the coil of the first actuator being a first coil, the second actuator including a second coil and a third coil, the second and third coils of the second actuator extending over respective portions of the first coil of the first actuator;  
 the scanning device further comprising: a holder to which the lens system is attached and about which wire is wound to form the coil; and a basic part to which the holder is connected by spring bars, at least two of the spring bars being connected to the coil to energize the coil.