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:
Aug. 19, 1997
Filed:
Jun. 26, 1995
Takahiro Ushiro, Kawasaki, JP;
Kazuki Miyamoto, Yokohama, JP;
Naoyuki Ohki, Yokohama, JP;
Shinichi Takata, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A fluorescent lamp controller for an original-document exposing apparatus includes a detection circuit for detecting the quantity of light emitted by a fluorescent lamp, an actuator for applying between filaments of the fluorescent lamp a voltage having a duty that is determined in accordance with the quantity of light detected, and a preheating circuit for preheating each of the filaments of the fluorescent lamp by applying a preheating voltage. According to the present invention, the actuator applies, between the filaments of the fluorescent lamp, a voltage having a duty which is smaller than the full duty regardless of a result of the quantity of light detected in a predetermined period at a start of turning the fluorescent lamp on, and the preheating circuit applies the preheating voltage to each of the filaments of the fluorescent lamp simultaneously with the application of the turning on voltage.