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:
Aug. 17, 1993
Filed:
Mar. 25, 1992
Masato Ishii, Kawasaki, JP;
Masanori Tokuhisa, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A toner quantity detecting system has a toner quantity detector (4c) and is capable of accurately detecting the decrease of the quantity of toner contained in the toner container of the developing unit of an image recording apparatus to an upper threshold quantity and to a lower threshold quantity regardless of the inherent output characteristic of the toner quantity detector (4c) and determining a prewarning voltage (E.sub.nep) representing the upper threshold quantity and a warning voltage (E.sub.emp) representing the lower threshold quantity so that the difference between the prewarning voltage (E.sub.nep) and the warning voltage (E.sub.emp) is sufficiently large. The prewarning voltage (E.sub.nep) and the warning voltage (E.sub.emp) are determined on the basis of the inherent output characteristic of the toner quantity detector (4c). The output voltage (E.sub.s) of the toner quantity detector (4c) is compared with the prewarning voltage (E.sub.nep) and the warning voltage (E.sub.emp) to provide a prewarning signal (NAL) upon the reduction of the quantity of the toner to the upper threshold quantity and to provide a warning signal (EAL) upon the reduction of the quantity of the toner to the lower threshold quantity.