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. 23, 2004
Filed:
May. 23, 2002
Yen-Hui Wang, Hsinchu, TW;
King Billion Electronics Co., Ltd., Hsinchu Hsien, TW;
Abstract
An optical signal detection apparatus and method for a computer mouse compares two output signals of a first photo-transistor and a second photo-transistor to obtain a reference signal. Then a pulse signal generating unit utilizes the reference signal to generate a series of pulse signals each occurring when the voltage level of the reference signal is changed. Thereafter a sample and hold circuit samples and holds the voltage value of the output signals of the photo-transistors at the moments that pulse signals are generated. A dynamic reference voltage generating unit uses the sampled voltage values to calculate a dynamic reference voltage. The voltage level of the dynamic reference voltage is varied with the output signals of the photo-transistors. By using the dynamic reference voltage to compare with the output signals of the photo-transistors, the on/off statuses of the photo-transistors can be precisely detected.