Optical read/write apparatus

Abstract

An optical read/write apparatus as an embodiment of the present invention includes: a light-splitting element configured to split a light beam emitted from a light source into multiple light beams including a write beam and a read beam; an optical system configured to converge the write and read beams onto the same track on an optical storage medium; a photodetector including a light receiving element configured to detect the read beam reflected from the optical storage medium and output an electrical signal; and a divider configured to generate a read signal by dividing the signal detected by the light receiving element by a signal that represents a write modulated component and that is obtained by detecting a part of the light beam emitted from the light source.

What is claimed is: 
     
         1 . An optical read/write apparatus with the ability to write data on a track on an optical storage medium and read the data that has been written on the track in parallel, the apparatus comprising:
 a light source;   an optical modulator configured to modulate the emission power of the light source according to the data to be written;   a light-splitting element configured to split a light beam emitted from the light source into multiple light beams including a write beam and a read beam;   an optical system configured to converge the write and read beams onto the same track on the optical storage medium so that while a write operation is being performed, the same location on the optical storage medium is scanned with the write beam before being scanned with the read beam;   a photodetector including a light receiving element configured to detect the read beam reflected from the optical storage medium and output an electrical signal; and   a divider configured to generate a read signal by dividing the signal detected by the light receiving element by a signal that represents a write modulated component of the light beam and that is obtained by detecting a part of the light beam emitted from the light source.   
     
     
         2 . The optical read/write apparatus of  claim 1 , wherein the light-splitting element is a diffraction grating. 
     
     
         3 . The optical read/write apparatus of  claim 1 , further comprising a front-monitor diode configured to output the signal representing the write modulated component of the light beam by detecting that part of the light beam emitted from the light source,
 wherein the divider generates the read signal by dividing the output of the light receiving element by the output of the front-monitor diode.   
     
     
         4 . The optical read/write apparatus of  claim 1 , wherein if the light receiving element is called a first light receiving element, the photodetector further includes a second light receiving element configured to output a signal representing the write modulated component of the light beam by detecting a part of the light beam that has been split by the light-splitting element and reflected from the optical storage medium, and
 wherein the divider generates the read signal by dividing the output of the first light receiving element by the output of the second light receiving element.   
     
     
         5 . The optical read/write apparatus of  claim 1 , wherein if the read beam is called a first read beam and if the light receiving element is called a first light receiving element, the light-splitting element splits the light beam emitted from the light source into multiple light beams including the write beam, the first read beam and a second read beam, and
 wherein the optical system is configured to converge the write beam and the first and second read beams onto the same track on the optical storage medium so that while a write operation is being performed, the same location on the optical storage medium is scanned with the write beam before being scanned with the first read beam and also scanned with the second read beam before being scanned with the write beam, and   wherein the photodetector includes a second light receiving element configured to detect the second read beam reflected from the optical storage medium and output an electrical signal, and   wherein the divider generates the read signal by dividing the output of the first light receiving element by the output of the second light receiving element.   
     
     
         6 .- 22 . (canceled)