US4679056A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal head with invertible heating resistors
Assignee: TDK Corp
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Filing: 1985-09-26
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Granted: 1987-07-07
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Expires: 2005-09-26
Abstract
Abstract A thermal head comprising heating resistors with their temperature coefficient of resistance being negative at normal temperature and invertible to be positive as the temperature rises.
Inventors
- 👤 Mikiya Kobayashi
- 👤 Takeshi Nakada
- 👤 Michio Arai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:24
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/335; B41J2/33505; B41J2/33515; B41J2/3355; B41J2/33555; B41J2/3357
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
65 words
A thermal head comprising heating resistors with their temperature coefficient of resistance being negative at normal temperature and invertible to be positive as the temperature rises, wherein the temperature coefficient of resistance of the heating resistors is from -500 to 0 ppm/° C. for 25°-150° C. and from 100 to 500 ppm/° C. for 25°-300° C., as represented by the average temperature coefficient of resistance.
Claim 2
Dependent Claim
65 words
A thermal head comprising heating resistors with their temperature coefficient of resistance being negative at normal temperature and invertible to be positive as the temperature rises, wherein the temperature coefficient of resistance of the heating resistors is from -500 to 0 ppm/° C. for 25°-150° C. and from 100 to 500 ppm/° C. for 25°-300° C., as represented by the average temperature coefficient of resistance.
Claim 3
Dependent Claim
17 words
The thermal head according to claim 1, wherein the heating resistors are made of a boron-doped polysilicone.
Claim 4
Dependent Claim
25 words
The thermal head according to claim 2, wherein said polysilicone contains boron at a concentration of from 10 +17 to 10 +20 /cm 3 .
Claim 5
Dependent Claim
51 words
A thermal head comprising heating resistors with their temperature coefficient of resistance being negative at normal temperature and invertible to be positive as the temperature rises, wherein the heating resistors are made of a boron-doped polysilicone containing boron at a concentration of from 10 +17 to 10 +20 /cm 3 .
Claim 6
Dependent Claim
51 words
A thermal head comprising heating resistors with their temperature coefficient of resistance being negative at normal temperature and invertible to be positive as the temperature rises, wherein the heating resistors are made of a boron-doped polysilicone containing boron at a concentration of from 10 +17 to 10 +20 /cm 3 .
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) | 1990-07-06 | 1991-01-05 | 1991-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-06 | 1995-01-05 | 1995-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-06 | 1999-01-05 | 1999-07-07 | $7700.00 | Window Closed / Lapsed |