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. 02, 1991
Filed:
Apr. 10, 1990
Wataru Yasuda, Yokohama, JP;
Moriyuki Koike, Kawasaki, JP;
Masaki Tokuhashi, Yokohama, JP;
Kouji Ishigaki, Yokohama, JP;
Yoshihiro Abe, Ichikawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An image density control method for an image forming apparatus of the type forming a latent image of a document image on a photoconductive element and developing the latent image to form a toner image by an electrophotographic procedure. A background pattern is implemented as a light pattern having a low density and provided independently of a reference density pattern. The light pattern is illuminated to form a latent image thereof on the photoconductive element, and the latent image is developed by a toner. The density of the resultant toner image is sensed by an image density sensor. Such a procedure allows a change in background density ascribable to contamination, increase in background potential and so forth to be detected. The light pattern may be replaced with a leading edge portion of a document if the leading edge portion has a density corresponding to the background density. Then, the latent image of the background pattern will be formed under exactly the same conditions as the latent image of an ordinary image, i.e., without any limitations as to the position of the pattern.