The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 19, 1993
Filed:
Apr. 26, 1991
Minoru Ohyama, Sagamihara, JP;
Tetsuhiro Yamazaki, Yokohama, JP;
Hiroshi Inoue, Yokosuka, JP;
Toshio Konno, Hoya, JP;
Victor Company of Japan, Ltd., Yokohama, JP;
Abstract
There is provided an optical pickup which emits a reading light to an optical disc having a pit in which information is stored and reads the information by means of the 0th order reflected light reflected from the pit and the diffracted light generated on the pit by diffraction effect. The optical pickup comprises a semiconductor laser for generating the reading light, a first photodiode for generatign a first electric signal corresponding to the intensity of the 0th order reflected light incident thereto, a second photodiode for generating a second electric signal corresponding to the intensity of the diffracted light incident thereto, a light focusing and guiding device for focusing the reading light to the pit and guiding the 0th order reflected light to the first photodiode, a light guiding device for guiding the diffracted light to the second photodiode and an operation device for generating an output signal by taking difference between the first and the second electric signals.