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:
Sep. 15, 1998
Filed:
Jun. 03, 1996
Makoto Nukui, Tokyo, JP;
Shuzo Seo, Tokyo, JP;
Takeharu Shin, Tokyo, JP;
Nobuhiro Tani, Tokyo, JP;
Yukihiro Ishizuka, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A casing, including a grip portion and a head portion, houses a pair of light sources for illumination, an image sensing device, an optical system for forming an image on the image sensing device, a photosensor for detecting the luminance of symbol reading area, a signal processing circuit, and a light quantity detection circuit. The housing extends from the head portion towards the symbol reading area. An ambient light window is provided in the housing for introducing ambient light into the symbol reading area. A light source driving circuit controls an amount of light emitted by the light source, by increasing or decreasing the amount of light, such that the combined ambient light and light source illumination is between predetermined levels. A selector is provided for selecting between a first mode, in which a maximum illumination is decreased to an upper limit of an acceptable illumination range, and a second mode, in which a minimum illumination is increased to a lower limit of an acceptable illumination range.