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:
Jul. 24, 2001
Filed:
Dec. 23, 1998
Katsuhide Koga, Mishima, JP;
Tomobumi Nakayama, late of Tokyo, JP;
Isamu Sato, Mishima, JP;
Tatsuhito Kataoka, Numazu, JP;
Yukio Yokoyama, Mishima, JP;
Takayuki Kawakami, Numazu, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An image forming apparatus, including a driving circuit for a multichip laser chip, which can limit or interrupt emission of laser light sources in accordance with a result of comparison of an optical output of each laser light source with a limiting value during time-division control is provided. The apparatus includes a plurality of laser light source, a light-amount control device for controlling an optical output of a laser beam from each of the plurality of laser light sources to a constant amount of light by performing time division processing, and a light detection device for detecting optical outputs of the plurality of laser light sources. The light detection device includes sensor units whose number is smaller than the number of the plurality of laser light sources. The apparatus also includes a limiting-value setting device for setting a limiting value for each optical output, a comparison device for comparing a time-division detection signal for a laser beam detected by the light detection device with the limiting value set by the limiting-value setting means during the time-division light-amount control by the light-amount control device, an emission control device for controlling emission of the plurality of laser light sources in accordance with an output signal from the comparison device, and a recording medium on which an image is formed by the plurality of laser beams.