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:
Apr. 02, 2002
Filed:
Jun. 10, 1998
Yoshimasa Kunimatsu, Niwa, JP;
Minoru Morikawa, Niwa, JP;
Shigeru Hayashi, Niwa, JP;
Sadao Kokubu, Niwa, JP;
Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho, Aichi-ken, JP;
Abstract
A method and apparatus are provided for reliably detecting a touch operation in a touch sensitive control surface, despite the influence of light or the existence of an obstruction. In the touch tracer, LEDs and phototransistors for detecting a touch position on the input pad are arranged to form parallel optical axes in the vertical direction and the horizontal direction. The optical axes of the LEDs and the phototransistors are alternately arranged in opposite directions to the adjacent optical axis. Moreover, the front surface of the phototransistor is closed except for an aperture that forms an optical axis only between opposing LEDs. The apertures are divided in half into top and bottom portions by a light-shielding film. Because of the light-shielding film, the phototransistor does not receive any light interference from the adjacent LED or incidental sunlight.