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:
Nov. 10, 1992
Filed:
Feb. 13, 1991
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
A toner empty detecting system for use in an electrophotographic printer. A sensor detects the presence of toner and provides toner-empty or toner-present signals. A first counter is incremented when toner-empty signals are detected at pre-determined time intervals and the first counter is cleared when a toner-present signal is detected. When the first counter reaches a predetermined value (first occurrence), the first counter is cleared and a second counter counts the number of printed pages until the first counter again reaches the same predetermined value (second occurrence). An indicator signals the first and second occurrence. Upon the second occurrence, the values of the first counter, second counter and indicator are compared and a comparison signal is provided. The printing is stopped if the comparison signal indicates that an actual toner-empty condition exists and the toner empty condition is displayed.