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. 12, 2008
Filed:
Feb. 17, 2005
Syoji Kasai, Hitachinaka, JP;
Toshiharu Amazawa, Hitachinaka, JP;
Katsuyoshi Kurisaki, Hitachinaka, JP;
Syoji Kasai, Hitachinaka, JP;
Toshiharu Amazawa, Hitachinaka, JP;
Katsuyoshi Kurisaki, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The invention provides a platform gate door device equipped with highly reliable photoelectric obstacle detectors that do not malfunction by disturbance light that moves, such as sunlight. The platform gate door device comprises a platform gate doorinstalled on a platform at a position where passengers get on and off a vehicle; a door control devicefor opening and closing the platform gate door; at least two photoelectric obstacle detectorsdisposed between the platform gate doorand the vehicle for detecting a presence of an obstacle, wherein each obstacle detectorhas a light emitterand a light receiverdisposed on either side of an openingof the platform gate door, and wherein the obstacle detectorsare arranged so that the direction of emission from the light emitters are mutually inversed; and a switching meansfor activating one of the plurality of obstacle detectors.