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:
Jan. 19, 1999
Filed:
Apr. 25, 1997
K Trent Christensen, Boise, ID (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A toner detecting system includes an image forming apparatus having a toner reservoir. A toner sensor of the system has a toner sensing element of piezoelectric material, the toner sensor carried within the toner reservoir to detect a toner level condition. A driver of the system is disposed to structurally excite at least a portion of the toner sensor when the portion is not immersed in toner, the excited at least a portion stressing the toner sensing element so as to impart a detectable output signal indicative of flexing of the toner sensor. A detector of the system is configured to receive the detected output signal and detect the toner level condition.