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:
Jun. 25, 1991
Filed:
Aug. 02, 1988
Shigeru Yoda, Mishima, JP;
Kouji Nitto, Takatsuki, JP;
Omron Tateisi Electronics Company, Kyoto, JP;
Abstract
There is provided an optical card information recording/playing back apparatus comprising: an optical system for irradiating a light beam for reproducing recorded information onto information recording tracks of the optical card on which pit trains indicative of recording information are formed; a photo detector for receiving the reflected light from the optical card and outputting a photo sensing signal; a pit correspondence signal producing circuit for detecting a peak of the photo sensing signal and producing a pit correspondence signal which changes in correspondence to a pit position on the basis of the result of the peak detection; a frequency/voltage converter for converting a frequency of the pit correspondence signal to a voltage; and a discrimination signal producing circuit for comparing a voltage output of the frequency/voltage converter with a reference value and producing an information presence/absence discrimination signal.