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. 09, 2016
Filed:
Oct. 19, 2015
Stanley Electric Co., Ltd., Meguro-ku, Tokyo, JP;
Ryohei Ikeno, Yokohama, JP;
Takao Saito, Tokyo, JP;
STANLEY ELECTRIC CO., LTD., Tokyo, JP;
Abstract
A video projection apparatus includes: a light source; an optical deflector having a mirror for reflecting light to project a view field, an actuator for rocking the mirror with an axis of the mirror and a sensor provided in the vicinity of the actuator; and a control unit. The control unit generates a sine-wave voltage applied to the actuator and a cosine-wave voltage; calculates a first convolution between the sine-wave voltage and a sense voltage from the sensor; calculates a second convolution between the cosine-wave voltage and the sense voltage; converts an orthogonal coordinate formed by the first convolution and the second convolution into a polar coordinate formed by a radius component and an angle component; and sweeps the frequency of the first and second voltages so that the frequency is defined as a resonant frequency when the radius component is maximum.