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US5319389A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of abnormal state detection for ink jet recording apparatus

Assignee: Canon Inc
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Filing: 1992-10-07
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Granted: 1994-06-07
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Expires: 2012-10-07
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Abstract

Abstract An ink jet recording apparatus records information by ejecting ink droplets onto a recording medium. The ink jet recording apparatus has a recording head; driving circuits, measuring circuit, and a judging unit. The recording head has ejection outlets and ink liquid passages connecting to the ejection outlets respectively, an electro-thermal converting element being disposed in each of the ink liquid passages, for generating thermal energy for ejecting the ink droplets. The driving circuits drive the electro-thermal converting element to generate the thermal energy enough to eject the ink droplet. The measuring circuit individually measures a resistance value of the electro-thermal converting element when the driving circuits drive the electro-thermal converting element. The judging unit judges presence of an abnormal state in the ink liquid passage according to the resistance value.

Inventors

  • 👤 Kazue Ikeda
  • 👤 Toshihiko Ujita
  • 👤 Kenjiro Watanabe

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 23:03
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/165; B41J2/16579

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 85 words
A method for inspecting a substrate, on which are disposed a plurality of electro-thermal converting elements and wiring for supplying the plurality of electro-thermal converting elements with electric signals, said method comprising the steps of: dividing the plurality of electro-thermal converting elements into a plurality of blocks; and judging a presence of an abnormal state in each of the electro-thermal converting elements of each of the blocks by supplying each of the electro-thermal converting elements of each of the blocks sequentially with the electric signals.
Claim 2
Independent Claim 85 words
A method for inspecting a substrate, on which are disposed a plurality of electro-thermal converting elements and wiring for supplying the plurality of electro-thermal converting elements with electric signals, said method comprising the steps of: dividing the plurality of electro-thermal converting elements into a plurality of blocks; and judging a presence of an abnormal state in each of the electro-thermal converting elements of each of the blocks by supplying each of the electro-thermal converting elements of each of the blocks sequentially with the electric signals.
Claim 3
Dependent Claim 23 words
A method according to claim 1, wherein a timing of a supply of said electric signals in each of the blocks is equal.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-06-06 1997-12-06 1998-06-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-06-06 2001-12-06 2002-06-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-06-06 2005-12-06 2006-06-07 $7700.00 Window Closed / Lapsed

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