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:
Mar. 07, 2000
Filed:
Dec. 05, 1997
Wen-Ping Cheng, TaoYuan, TW;
Min-Kun Wang, Hsinchu, TW;
Fang-Diahn Guo, Hsinchu, TW;
Chi-Ho Hsu, Taipei, TW;
Holtek Semiconductor Inc., , TW;
Abstract
A photocoupling signal detection circuit for a computer mouse to simplify the design of circuit by tracking the slope change of input voltage waveform and produce a digital output which can detect the movement of computer mouse is disclosed. This signal detection circuit includes a comparator, a state decision circuit, an up/down counter, and a D/A converter. The comparator produces an up/down signal connected to the state decision circuit, then the up/down signal connected to the up/down counter to transfer the up/down signal into a digital signal output. The digital signal connected to a D/A converter for transferring into an analog signal, and the analog signal can be compared with the output signal of an phototransistor. According to the state of up/down signal, the state decision circuit determines if the phototransistor is turned on or turned off and outputs different state signals, based on its determination. The output state signal is further utilized for the detection of a computer mouse.