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:
Mar. 07, 2000
Filed:
Oct. 24, 1997
Naoyuki Kamei, Nara, JP;
Koichi Eto, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A lamp power supply circuit for an image forming device, which is not provided with a full-wave rectifier and any additional noise reducing circuit but is capable of effectively suppressing inrush current not to produce noise that may cause erroneous operation of the image forming device and affect any external appliance. A lamp lighting control system for use in an image forming device, which can realize soft-starting of an exposure lamp or a fixing heater-lamp by gradually increasing a conducting angle .beta..sub.i (i=0, 1 . . . ) for applying a voltage to a lamp through phase control of an AC power-supply voltage V.sub.AC for an initial period of energizing the exposure lamp or the fixing heater-lamp. Wherein, the conducting angle is gradually increased per even-number unit of cycles of AC power-supply voltage V.sub.AC on the condition that even numbers of cycles in the same unit have the same conducting angle, e.g., .beta..sub.0 =.beta..sub.1 <.beta..sub.2 =.beta..sub.3 <.beta..sub.4 =.beta..sub.5 <.beta..sub.6 =.beta..sub.7 < . . . <.beta..sub.16 =.beta..sub.17.