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US4712930A Expired / Lapsed US ⏱️ 0.0 years remaining

Gradation thermal printhead and gradation heat transfer printing apparatus

Assignee: Panasonic Holdings Corp
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Filing: 1986-09-04
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Granted: 1987-12-15
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Expires: 2006-09-04
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Abstract

Abstract A gradation thermal printhead having a plurality of heat generating elements each having a heat generating body connected between a pair of electrodes, the electric resistance value of the heat generating body being locally increased in one or more portions thereof. Disclosed also is a gradation heat transfer printing apparatus making use of the gradation thermal printhead mentioned above and employing an energy controlling means for varying the voltage or pulse width of the signal pulse voltage applied to the thermal printhead, thereby allowing a control of the area of the printed dot corresponding to one heat generating element, i.e., the density of printing, thus attaining a gradation control of the printed image.

Inventors

  • 👤 Susumu Maruno
  • 👤 Shinobu Nakata
  • 👤 Michinori Nagahiro
  • 👤 Seiko Minamide

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 20:25
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40025; H04N1/40031; B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/345

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 66 words
A gradation thermal printhead comprising a plurality of heat generating elements arranged in a line, each of said heat generating elements having a pair of electrodes and a heat generating body connected between said electrodes, said heat generating body having an electric resistance value distribution such that the resistance value is changed in a staggered manner at least in the direction of connection to said electrodes.
Claim 2
Dependent Claim 66 words
A gradation thermal printhead comprising a plurality of heat generating elements arranged in a line, each of said heat generating elements having a pair of electrodes and a heat generating body connected between said electrodes, said heat generating body having an electric resistance value distribution such that the resistance value is changed in a staggered manner at least in the direction of connection to said electrodes.
Claim 3
Dependent Claim 35 words
A gradation thermal printhead according to claim 1, wherein said staggered manner of variation in the electric resistance value is formed by at least one of notches and apertures formed in said heat generating body.
Claim 4
Dependent Claim 156 words
A gradation heat transfer printing apparatus comprising: a gradation thermal printhead having a plurality of heat generating elements arranged in a line, each of said heat generating elements having a pair of electrodes and a heat generating body connected between said electrodes, said heat generating body having an electric resistance value distribution such that the resistance value is varied in a staggered manner at least in the direction of connection to said electrodes; and an energy controlling means for controlling the energy applied to said thermal printhead; said apparatus employing a heat transfer ink sheet having a base film and a color material layer formed as a transfer medium on said base film; whereby the area of transfer of said color material layer corresponding to one heat generating element is varied through the control of the electric energy applied to said thermal printhead by said energy controlling means, thereby attaining a gradation printing of an image.
Claim 5
Dependent Claim 156 words
A gradation heat transfer printing apparatus comprising: a gradation thermal printhead having a plurality of heat generating elements arranged in a line, each of said heat generating elements having a pair of electrodes and a heat generating body connected between said electrodes, said heat generating body having an electric resistance value distribution such that the resistance value is varied in a staggered manner at least in the direction of connection to said electrodes; and an energy controlling means for controlling the energy applied to said thermal printhead; said apparatus employing a heat transfer ink sheet having a base film and a color material layer formed as a transfer medium on said base film; whereby the area of transfer of said color material layer corresponding to one heat generating element is varied through the control of the electric energy applied to said thermal printhead by said energy controlling means, thereby attaining a gradation printing of an image.
Claim 6
Dependent Claim 37 words
A gradation heat transfer printing apparatus according to claim 3, wherein said staggered manner of variation in the electric resistance value is formed by at least one of notches and apertures formed in said heat generating body.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-12-14 1991-06-15 1991-12-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-12-14 1995-06-15 1995-12-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-12-14 1999-06-15 1999-12-15 $7700.00 Window Closed / Lapsed

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