| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light receiving and emitting integrated device which can be connected to an IC for optical pickup of a discrete package type independently of the use of a knife edge method for a focus servo signal. <P>SOLUTION: In a light receiving and emitting integrated device 41, light emitted from a semiconductor laser 23 is branched to first to third light by a diffraction grating 24, the first to the third light reflected by an optical recording medium 14 are divided by a hologram element 43 divided into four first to fourth regions, the first light out of divided first to third light is received and detected by four light receiving segments (A, B, C, D) provided in a light receiving element 44. And a focus servo signal is obtained by the knife edge method using a detected output of the first light received and detected by four light receiving segments (A, B, C, D). <P>COPYRIGHT: (C)2006,JPO&NCIPI |
