Optical information recording apparatus and method

Abstract

Recording of information by utilizing a holography to each information recording area while moving a record medium having information recording areas by means of a practical light source. For recording of information on an information recording area ( 7 ) of a record medium, an irradiated position ( 101 ) is moved so that the irradiated position ( 101 ) with information light and recording reference light may follow on information recording area ( 7 ) which moves for a predetermined period. Thus, one information recording area ( 7 ) keeps on being irradiated with information light and recording reference light, so that information is recorded on this information recording area ( 7 ) in interference patterns due to the interference of the information light with the recording reference light.

1 . An optical information recording apparatus for recording information on a recording medium by irradiating the recording medium with recording light, the recording medium includes an information recording layer in which information is recorded using holography and a servo layer in which servo information is formed, the optical information recording apparatus comprising: 
 a recording laser for emitting recording laser light used to generate the recording light;    a servo laser for emitting servo laser light with a wavelength which differs from a wavelength of the recording laser light, the servo laser being used for performing servo to determine a position of the recording light on the recording medium; and    recording means for recording information on the recording medium by generating the recording light using the recording laser light and irradiating the information recording layer of the recording medium with the recording light, and for performing servo by irradiating the servo layer with the servo laser light, wherein    the recording means comprises: 
 an information light generating means for generating information light carrying information by spatially modulating the recording laser light,  
 recording reference light generating means for generating recording reference light using the recording laser light, and  
 a recording optical system for coaxially irradiating the recording medium with the information light and the recording reference light, the information being recorded on the recording medium by interference patterns that are generated by interference between the information light and the recording reference light.  
   
     
     
         2 . The optical information recording apparatus according to  claim 1 , further comprising control means for controlling emission of the recording laser light from the recording laser and emission of the servo laser light from the servo laser.  
     
     
         3 . The optical information recording apparatus according to  claim 2 , wherein the recording medium has the servo layer in which address information is recorded, the recording means irradiating the servo layer with the servo laser light and reproducing address information, the control means determining whether a current state is a servo state or a recording of information state based on reproduced address information.  
     
     
         4 . The optical information recording apparatus, according to  claim 2 , wherein the recording medium has the servo layer, the recording means irradiating the servo layer with the servo laser light and performing servo, the control means preventing emission of the recording laser light from the recording laser when the servo laser light is irradiating the servo layer.  
     
     
         5 . The optical information recording apparatus according to  claim 2 , wherein the control means selectively performs emission of the recording laser light from the recording laser and emission of the servo laser light from the servo laser based on whether a current state is a servo state or a recording of information state.  
     
     
         6 . The optical information recording apparatus according to  claim 1 , wherein the recording reference light generation means comprises a spatial modulator for spatially modulating a phase of the recording laser light to generate the recording reference light.  
     
     
         7 . An optical information reproducing apparatus for reproducing information from a recording medium by irradiating the recording medium with reproducing light, the recording medium including an information recording layer in which information is recorded using recording light by holography, and a servo layer in which servo information is formed, the optical information reproducing apparatus comprising: 
 a reproducing laser for emitting reproducing laser light used to generate reproducing light, the reproducing laser light having a same wavelength as a recording laser light used to generate the recording light;    a servo laser for emitting servo laser light with a wavelength which differs from a wavelength of the reproducing laser light, the servo laser being used for performing servo to determine a position of the reproducing light on the recording medium; and    reproducing means for reproducing information from the recording medium by generating the reproducing light using the reproducing laser light and irradiating the information recording layer of the recording medium with the reproducing light, and for performing servo by irradiating the servo layer on the recording medium with the servo laser light.    
     
     
         8 . The optical information reproducing apparatus according to  claim 7 , further comprising control means for controlling emission of the reproducing laser light from the reproducing laser and emission of the servo laser light from the servo laser.  
     
     
         9 . The optical information reproducing apparatus according to  claim 7 , wherein the reproducing means comprises: 
 reproducing reference light generating means for generating reproducing reference light using the reproducing laser light; and    a reproducing optical system for illuminating the information recording layer with the reproducing reference light generated by the reproducing reference light generating means and for collecting a reproduction light generated at the information recording layer when illuminated with the reproducing reference light, the reproducing reference light and the reproduction light being coaxial.    
     
     
         10 . The optical information reproducing apparatus according to  claim 8 , wherein the recording medium has the servo layer on which address information is recorded, the reproducing means reproducing address information by irradiating the servo layer with the servo laser light, the control means determining whether a current state is a servo state or a reproducing information state based on reproduced address information.  
     
     
         11 . The optical information reproducing apparatus according to  claim 8 , wherein the recording medium has the servo layer, the reproducing means irradiating the servo layer with the servo laser light and performing servo, the control means preventing the emission of the reproducing laser light from the reproducing laser when the servo laser light is irradiating the servo layer.  
     
     
         12 . The optical information reproducing apparatus according to  claim 8 , wherein the control means selectively performs emission of the reproducing laser light from the reproducing laser and emission of the servo laser light from the servo laser based on whether a current state is a servo state or a reproducing of information state.  
     
     
         13 . The optical information reproducing apparatus according to  claim 9 , wherein the reproducing reference light generating means has a spatial modulator for spatially modulating a phase of the reproducing laser light to generate the reproducing reference light.