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:
Feb. 23, 2010
Filed:
Aug. 10, 2007
Hideaki Inoue, Musashimurayama, JP;
Hideaki Inoue, Musashimurayama, JP;
Casio Computor Co., Ltd., Tokyo, JP;
Abstract
A light sourceof a projection unitAM modulates an electric current supplied to a built-in LED. The projection unitprojects the modulated light on a projection screen. A photoreceiverreceives, with a time lag, a reflected portion of the modulated light from the screen, which corresponds to a time required for the light to travel from its projection to its reception. A calculation unitacquires a phase difference between the projected light and its reflection at a respective one of a plurality of points on the screen, acquires a distance from the projector to the respective one of the plurality of points on the screen, and then acquires an inclination angle of the screen. Because the distance from the projector to a respective one of the plurality of points on the screen is acquired based on the corresponding phase difference, the measurement accuracy is improved compared to the triangular distance measuring method. The projector requires no distance measurement-only light source, thereby reducing the size of the projector.