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:
Jun. 08, 1993
Filed:
Sep. 17, 1990
Masayuki Tanaka, Hyogo, JP;
Kunio Tsuboi, Hyogo, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
An image forming apparatus is loaded with a developing device capable of being easily exchanged, and a toner sensor for detecting a toner density is provided in association with the developing device. An output signal of the toner sensor approaches 0 V as a weight of a developer becomes small. Therefore, when the output signal from the toner sensor is detected prior to an agitating screw is operated when a power source is turned-on, it is possible to determine whether a developing device attached at that time is an unused or used one in accordance with the output signal. In addition, the output of the toner sensor when the developing device is an unused one is stored in a backed-up memory as a reference value for controlling a toner density during an actual operation.