US4626871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal print head wear bar
Assignee: GID ACQUISITION Co
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Filing: 1985-02-08
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Granted: 1986-12-02
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Expires: 2005-02-08
Abstract
Abstract A thermal print head for use in thermal printing apparatus has a pattern of conductive lines for energizing a resistive member overlying a portion of the lines to generate discrete heated spots on the resistive member. A screen-printed protective coating over a portion of the pattern is adapted to reduce the abrasive effect of grit particles carried on the medium to be printed. The coating comprises a layer of dried and fired material formed of a ceramic/glass overglaze composition mixed with fine metallic oxide particles.
Inventors
- 👤 Richard C. Schuessler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:05
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/335; B41J2/33505; B41J2/3353; B41J2/33555; B41J2/3357
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
135 words
A thermal print head for use in thermal printing apparatus, said print head comprising: a substrate; a pattern of conductive lines on said substrate; a resistive member overlying a portion of said lines, said lines adapted to generate discrete heated spots on said resistive member in response to excitation of said conductive lines; and a screen-printed protective coating over a portion of said pattern and adapted to reduce the abrasive effect of grit particles carried on a medium to be printed which is passed over said protective coating and resistive member, said coating comprising a layer of dried and fired material formed of a ceramic/glass overglaze composition mixed with fine metallic oxide particles, wherein said particles comprise zirconium oxide, said zirconium oxide constituting approximately 5 to 15 percent, by weight, of said overglaze composition/particle mixture.
Claim 2
Dependent Claim
135 words
A thermal print head for use in thermal printing apparatus, said print head comprising: a substrate; a pattern of conductive lines on said substrate; a resistive member overlying a portion of said lines, said lines adapted to generate discrete heated spots on said resistive member in response to excitation of said conductive lines; and a screen-printed protective coating over a portion of said pattern and adapted to reduce the abrasive effect of grit particles carried on a medium to be printed which is passed over said protective coating and resistive member, said coating comprising a layer of dried and fired material formed of a ceramic/glass overglaze composition mixed with fine metallic oxide particles, wherein said particles comprise zirconium oxide, said zirconium oxide constituting approximately 5 to 15 percent, by weight, of said overglaze composition/particle mixture.
Claim 3
Dependent Claim
21 words
A thermal print head according to claim 1, said coating having a height less than the height of said resistive member.
Claim 4
Dependent Claim
36 words
A thermal print head according to claim 2, said coating further comprising a second layer of smooth, hard dielectric glass between said conductive lines and said first-named layer, said second layer being harder than said layer.
Claim 5
Dependent Claim
15 words
A thermal print head according to claim 3, said first layer having a matte finish.
Claim 6
Dependent Claim
20 words
A thermal print head according to claim 1, said metallic oxide particles having sizes ranging from 0.5 to 2.0 microns.
Claim 7
Dependent Claim
24 words
A thermal print head according to claim 1, said layer, before drying and firing, having a viscosity of approximately 5,000 centipoise at 70° Fahrenheit.
Claim 8
Dependent Claim
23 words
A thermal print head according to claim 1, wherein the proportion of ceramic/glass overglaze composition to said particles is approximately 9:1, by weight.
Claim 9
Dependent Claim
31 words
A thermal print head according to claim 1, wherein said particles also comprise aluminum oxide, said aluminum oxide constituting approximately 10 to 0 percent, by weight, of said overglaze composition/particle mixture.
Claim 10
Dependent Claim
90 words
A protective coating for protecting electronic circuitry from abrasive particles carried on a tape passing over said circuitry in rubbing contact therewith, said protective coating being a mixture comprising, in a predetermined proportion, a fused ceramic/glass overglaze composition and fine metallic oxide particles, wherein said particles comprise zirconium oxide, said zirconium oxide constituting approximately 5 to 15 percent, by weight, of said overglaze composition/particle mixture, and wherein said coating, before fusing, has a viscosity of approximately 5,000 centipoise at 70° Fahrenheit, so as to be suitable for application by screen-printing.
Claim 11
Dependent Claim
90 words
A protective coating for protecting electronic circuitry from abrasive particles carried on a tape passing over said circuitry in rubbing contact therewith, said protective coating being a mixture comprising, in a predetermined proportion, a fused ceramic/glass overglaze composition and fine metallic oxide particles, wherein said particles comprise zirconium oxide, said zirconium oxide constituting approximately 5 to 15 percent, by weight, of said overglaze composition/particle mixture, and wherein said coating, before fusing, has a viscosity of approximately 5,000 centipoise at 70° Fahrenheit, so as to be suitable for application by screen-printing.
Claim 12
Dependent Claim
13 words
A protective coating according to claim 9, said coating having a matte finish.
Claim 13
Dependent Claim
19 words
A protective coating according to claim 9, said metallic oxide particles having sizes ranging from 0.5 to 2.0 microns.
Claim 14
Dependent Claim
22 words
A protective coating according to claim 9 wherein the proportion of ceramic/glass overglaze compostiion to said particles is approximately 9:1, by weight.
Claim 15
Dependent Claim
30 words
A protective coating according to claim 9, wherein said particles also comprise aluminum oxide, said aluminum oxide constituting approximately 10 to 0 percent, by weight, of said overglaze composition/particle mixture.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-01 | 1990-06-02 | 1990-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-01 | 1994-06-02 | 1994-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-01 | 1998-06-02 | 1998-12-02 | $7700.00 | Window Closed / Lapsed |