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:
Mar. 09, 2004
Filed:
Dec. 05, 2001
Kunio Satou, Hitachinaka, JP;
Takahiro Yamada, Hitachinaka, JP;
Hitoshi Kida, Hitachinaka, JP;
Shinya Kobayashi, Hitachinaka, JP;
Kazuo Shimizu, Hitachinaka, JP;
Hitachi Printing Solutions, Ltd., Kanagawa-Ken, JP;
Abstract
When positively charged ink droplets from a defective nozzle impact a negatively charged deflector electrode , the positive charge on condenser flows to the ground via a FET of a photo-coupler . As a result, the electric discharge occurs by an amount equivalent to the charging amount of the ink droplets clinging on the electrode . Because a switching signal is “1”, the ON resistance of the photo-coupler is large, and the ON resistance of the FET of the photo-coupler is small. Accordingly, the discharge due to the charged ink droplets is detected as a large detection voltage and amplified by an operational amplifier . Because the charger voltage of the condenser is static and has no noise, even when the detection output is highly amplified, noise during the detection is suppressed.