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. 25, 2003
Filed:
Feb. 14, 2001
Yoshiyuki Imanaka, Kasawaki, JP;
Shinji Takagi, Kawasaki, JP;
Ichiro Saito, Yokohama, JP;
Toshiharu Inui, Yokohama, JP;
Kentaro Yano, Yokohama, JP;
Tetsuhito Ikeda, Tokyo, JP;
Masao Kato, Utsunomiya, JP;
Katsuhiko Takahashi, Yokohama, JP;
Muga Mochizuki, Yokohama, JP;
Kenichi Saito, Kawasaki, JP;
Tomonori Sato, Kawasaki, JP;
Toru Kubokawa, Hiratsuka, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
The present invention allows the detection of ink in a printing head that can be widely applied to various printing systems by significantly simplifying its configuration. There are a heater for supplying an energy to eject ink, a driver for driving the heater, and a detection electrode capable of detecting a voltage variation that arises between the heater and the driver and that depends on the driving of the heater. Furthermore, an insulating film that covers the surface of the detection electrode protects the detection electrode from chemical or physical change. Furthermore, a reference element group or a reference unit that produces a signal as a reference of the detection signal avoids the influence of noise. Furthermore, an energy-generating element and another signal source improve the accuracy of ink detection. A drive pulse which is insufficient to eject ink may be supplied to the heater to improve the accuracy of ink detection.