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:
Aug. 07, 1984
Filed:
May. 13, 1982
Tsuyoshi Ono, Yamato, JP;
Fumiaki Ohno, Fujisawa, JP;
Victor Company of Japan, Ltd., Yokohama, JP;
Abstract
A separation band detecting circuit is used in an automatic program selection record player which has a photodetector which moves together with a tone arm and comprises a light-emitting element for emitting light against the surface of the record and a photosensitive element for receiving the light reflected at the record surface and producing an output in accordance with the light quantity of the received reflected light. The detecting circuit comprises an operational amplifier supplied with the output of the photodetector to its one input terminal, and a time constant circuit connected to the other input terminal of said operational amplifier, for giving a threshold level with respect to the operational amplifier and giving a time constant with respect to the level fluctuation in the threshold value. The time constant circuit varies the threshold level with a time constant, according to an input signal level to the one input terminal of the operational amplifier. The operational amplifier inverts its output when the relationship between amplitudes of the input signal level and the threshold level reverses.