US3736406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermographic print head and method of making same
Assignee: RCA Corp
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Filing: 1972-06-21
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Granted: 1973-05-29
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Expires: 1992-06-21
Abstract
Abstract A thermographic print head for encoding labels on thermographic paper is made by a method of depositing, on an electrically insulating substrate, first and third layers of electrically conductive material separated by a second layer of insulating material. The first layer comprises a plurality of separated terminal leads, and the third layer comprises a plurality of separated concentric ring conductors, each of which is connected to selected terminals of the first layer through vias in the separating second layer of electrically insulating material.
Inventors
- 👤 J Vossen
- 👤 Neill J O
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:37
CPC Classifications
G; G06; G06K; G06K1/00; G06K1/12; G06K1/126; B; B41; B41M; B41M5/00; B41M5/26
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
110 words
A thermographic print head comprising: an electrically insulating substrate, a first layer of electrically conductive material comprising a plurality of separated terminal leads disposed on a surface of said substrate, a second layer of electrically insulating material disposed over portions of said separated terminal leads and portions of said surface of said substrate between said terminal leads, a plurality of vias formed in said second layer, each of said vias extending to said first layer, and a third layer of electrically conductive material comprising a plurality of separated conductors disposed over said second layer, each of said conductors extending to, and contacting, two of said terminal leads through said vias.
Claim 2
Dependent Claim
110 words
A thermographic print head comprising: an electrically insulating substrate, a first layer of electrically conductive material comprising a plurality of separated terminal leads disposed on a surface of said substrate, a second layer of electrically insulating material disposed over portions of said separated terminal leads and portions of said surface of said substrate between said terminal leads, a plurality of vias formed in said second layer, each of said vias extending to said first layer, and a third layer of electrically conductive material comprising a plurality of separated conductors disposed over said second layer, each of said conductors extending to, and contacting, two of said terminal leads through said vias.
Claim 3
Dependent Claim
22 words
A thermographic print head as described in claim 1, wherein a fourth layer of electrically insulating material is disposed over said conductors.
Claim 4
Dependent Claim
62 words
A thermographic print head as described in claim 2, wherein each of said second and fourth layers comprises sputtered glass having a melting point in excess of 490*C and a thermal expansion of about 3.3 X 10 6/*C, and said second layer is a composite of a bottom layer of said sputtered glass and a top layer of chemically vapor-deposited borosilicate glass.
Claim 5
Dependent Claim
95 words
A thermographic print head as described in claim 1, wherein said plurality of conductors comprises a plurality of concentric rings, and said plurality of terminal leads comprises a relatively large common terminal lead and a plurality of relatively much narrower elongated terminal leads, each of said rings being connected to said common terminal lead and to a separate one of said elongated terminal leads through a selected pair of said vias, respectively, the vias in each of said pairs of vias being spaced 180* from each other, with respect to the center of said rings.
Claim 6
Dependent Claim
57 words
A thermographic print head as described in claim 4, wherein each of a plurality of said elongated terminal leads extends in a radial direction from a point in common, said elongated terminal leads have exposed terminal connecting portions that are parallel to each other, and a fourth layer of electrically insulating material is disposed over said rings.
Claim 7
Dependent Claim
30 words
A thermographic print head as described in claim 1, wherein the ratio of the sheet resistivity of said third layer to that said first layer is between 2.7 and 10.
Claim 8
Dependent Claim
35 words
A thermographic print head as described in claim 6, wherein said second layer has a thickness of about 50,000A, and said first layer has a sheet resistivity of between 0.075 and 0.185 ohms per square.
Claim 9
Dependent Claim
33 words
A thermographic print head as described in claim 1, wherein said first layer is a composite layer of a relatively thin lower layer of chromium and a relatively thicker upper layer of molybdenum.
Claim 10
Dependent Claim
18 words
A thermographic print head as described in claim 1, wherein said first and said third layers comprise molybdenum.
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) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |