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. 27, 2001
Filed:
May. 21, 1996
Takeshi Kono, Kawasaki, JP;
Atsushi Saito, Yokohama, JP;
Takashi Ono, Yokosuka, JP;
Shinichiro Koori, Kawasaki, JP;
Yukio Nohata, Yokohama, JP;
Shigeyuki Sugiyama, Hiratsuka, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A plurality of ejection openings of an ink-jet head are divided into four blocks and ink ejection is performed for each block. An output of a photosensor which depends upon a number of ejected ink droplets interrupting light at a photosensor is sampled. On a basis of the sensor output, judgement is made whether ejection failure is present of the relevant block. This in ejection openings process is performed sequentially for other blocks. By this, even when a given rate of error is present in detecting precision of the photosensor, since overall number of ejection openings for which the detection is made is smaller, the number of faulty ejection openings which cannot be detected can be made smaller.