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.

Date of Patent:
Apr. 09, 1991

Filed:

Nov. 06, 1989
Applicant:
Inventors:

Yasushi Koichi, Yamato, JP;

Norimasa Sohmiya, Soka, JP;

Kazunori Karasawa, Tokyo, JP;

Assignee:

Ricoh Company, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03G / ;
U.S. Cl.
CPC ...
355246 ;
Abstract

A method applicable to an image forming apparatus which is implemented by an electrophotographic procedure for maintaining that the density of images to be produced by the apparatus is adequate at all times. When the density of a toner image of a reference image or a predetermined pattern sensed by the image density sensor lies in a predetermined adequate range, a sensing level associated with the toner density sensor responsive to the toner density of a developer is not changed. When the density of the toner image does not lie in the adequate range, it is determined that at least the sensing level of the toner density sensing being used at that time has to be changed. Then, whether or not the sensed density of the toner image of the reference image exists in a range in which the image density is controllable is determined. If the sensed density lies in the controllable range, the sensing level of the density sensor being used at that time is suitably changed in response to the sensed density of the toner image. If otherwise, i.e., when the image density sensor is in a fault, toner density control is continued without changing the sensing level of the toner image sensor being used.


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