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.

Date of Patent:
Dec. 16, 1997

Filed:

Apr. 23, 1996
Applicant:
Inventors:

Tomoaki Kodama, Hadano, JP;

Kazuyoshi Hibiya, Odawara, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02F / ;
U.S. Cl.
CPC ...
250221 ; 2502 / ;
Abstract

The light selected by a selection circuit 3 at a light emitting side and emitted from a light emitting element 1 such as a LED is converted to a specifically modulated light by an oscillation circuit 11. The light received by a light receiving element 2 such as a phototransistor at the receiving side is amplified by an amplifier circuit 6, and a detection circuit 12 detects whether a specifically modulated light is received. The H/L detection circuit 13 determines the presence/absence of a light interruption to produce a signal of either H (high level) or L (low level). Also, the signal from the oscillator 11 of the emission side is received by the receiving side and compared with the received signal to determine whether the same signal as emitted from the emitting element has been actually received.


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