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:
Jul. 27, 2021

Filed:

Feb. 21, 2020
Applicants:

Benq Intelligent Technology (Shanghai) Co., Ltd, Shanghai, CN;

Benq Corporation, Taipei, TW;

Inventor:

Shih-Pin Chen, Taoyuan, TW;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J 1/46 (2006.01); G02B 26/00 (2006.01); G03B 21/20 (2006.01); G01J 1/44 (2006.01);
U.S. Cl.
CPC ...
G01J 1/46 (2013.01); G02B 26/008 (2013.01); G03B 21/2006 (2013.01); G01J 2001/4473 (2013.01);
Abstract

A light detection circuit for a projector is provided. The light detection circuit includes: a light transistor for receiving and sensing reflected light from a side of a color wheel driving motor of the projector, wherein the side of the color wheel driving motor includes a dark region and a bright region; a bias unit coupled to the light transistor for providing a bias voltage; an operation amplifier including a positive input coupled to the bias unit, a negative input coupled to the light transistor and the bias unit, and an output, the base unit providing the bias voltage to the positive input; and a feedback resistor coupled between the negative input of the operation amplifier and the output, wherein, a resistance of the feedback resistor causes the light transistor to be operated in a linear region.


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