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:
Nov. 08, 2005
Filed:
Mar. 14, 2000
Katsuyuki Kobayashi, Yokohama, JP;
Masahide Hasegawa, Yokohama, JP;
Kiwamu Kobayashi, Yokohama, JP;
Masaaki Kanashiki, Yokohama, JP;
Atsushi Tanaka, Yamato, JP;
Yuichiro Yoshimura, Kamakura, JP;
Katsuyuki Kobayashi, Yokohama, JP;
Masahide Hasegawa, Yokohama, JP;
Kiwamu Kobayashi, Yokohama, JP;
Masaaki Kanashiki, Yokohama, JP;
Atsushi Tanaka, Yamato, JP;
Yuichiro Yoshimura, Kamakura, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
The invention aims to provide a coordinate input apparatus having high detection reliability and high efficiency and to control the influence of ambient light using a simple structure. The apparatus detects a light spot flashing on and off in a predetermined cycle and incident at a desired position on a coordinate input screen, and includes a detection device having photoelectric conversion elements corresponding to N pixels for detecting a light spot coordinate. The difference between signals from photoelectric elements in light emission state and in light non-emission state at each N pixel is found, and the smaller of the difference signals of the m-th pixel having the maximum difference signal is set as a threshold value. Effective pixels are identified based on the threshold value, and the coordinate is calculated by using the difference data of the selected effective pixels.