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. 20, 1999
Filed:
Nov. 18, 1996
Akira Shimura, Kawasaki, JP;
Shuichi Yamazaki, Fujimi, JP;
Tomohiro Nakajima, Machida, JP;
Masaki Narita, Tokyo-to, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A method and apparatus that prevent degradation of an image quality due to a change of a beam pitch in a subscanning direction of each optical beam on a record medium. At a given time, for example, when power is first turned on, a CPU detects a beam pitch on a record medium, e.g., a photosensitive drum, by using a CCD line image sensor. If the detected value differs from a value set according to a currently-selected scanning density, an LD arrangement change motor is rotated via a motor driver so that the beam pitch matches the set value so as to change an arrangement of laser diodes in a laser diode array. Control over the beam pitch occurs for a variety of conditions including control at regular intervals, power-on events, or when a scanning density specification signal indicates a different beam pitch than the detected beam pitch. Similarly, adjustment over the beam pitch is not typically made during a copying operation.