EP0241304A2
Expired / Lapsed
EP
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Thermal printing apparatus
Assignee: NGK Insulators Ltd
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Filing: 1987-04-10
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Granted: —
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Expires: 2007-04-10
Abstract
Abstract A printing apparatus, for printing on a recording medium by using an ink film which has an electrically resistive layer and a thermally fusible and transferable ink layer, has a thermal head which has a substrate (6) and a plurality of recording electrodes (7) disposed on the substrate. Each electrode has a contact portion (8) held in contact with the resistive layer of the ink film. The contact portions of two electrodes cooperate to energize the electrically resistive layer of the ink film, so that the energized portion generates Joule heat for softening the ink material and transferring the softened ink material onto a recording medium. To give the head the desired wear resistance, the substrate (6) of the thermal head is made of a material having a low wear resistance, and at least the contact portion (8) of each electrode (7) is made of an electrically conductive material which has a major component which is a metal silicide; at least one of the metals chromium, titanium, tantalum, zirconium, hafnium and niobium; or at least one alloy or metal compound which contains at least one of those metals.
Inventors
- 👤 Yukihisa Takeuchi
- 👤 Tetsuo Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 16:33
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/335; B41J2/33505; B41J2/3351; B41J2/33515; B41J2/3355; B41J2/33555; B41J2/3357; B41J2/3359; B41J2/345
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
216 words
A printing apparatus for printing on a recording medium by using an ink film which has an electrically resistive layer and an ink layer consisting of an ink material which is thermally fusible and transferable to said recording medium, said printing apparatus comprising: a printing head which has a substrate (6) and a plurality of recording electrodes (7;9) disposed on said substrate, each of said plurality of electrodes including a contact portion (8) which in use is held in contact with said electrically resistive layer of said ink film, and adapted to cooperate with another electrode or electrodes to apply a voltage to said electrically resistive layer, thereby energizing a portion of the electrically resistive layer so that the energized portion generates Joule heat for softening said ink material on said energized portion and transferring the softened ink material onto said recording medium, characterized in that at least part of said contact portion (8) of each said recording electrode (7,9) consists essentially of an electrically conductive material which has a major component which is a metal silicide; at least one of the metals chromium, titanium, tantalum, zirconium, hafnium and niobium; at least one alloy which contains at least one of said metals; or at least one metal compound which contains at least one of said metals.
Claim 2
Dependent Claim
216 words
A printing apparatus for printing on a recording medium by using an ink film which has an electrically resistive layer and an ink layer consisting of an ink material which is thermally fusible and transferable to said recording medium, said printing apparatus comprising: a printing head which has a substrate (6) and a plurality of recording electrodes (7;9) disposed on said substrate, each of said plurality of electrodes including a contact portion (8) which in use is held in contact with said electrically resistive layer of said ink film, and adapted to cooperate with another electrode or electrodes to apply a voltage to said electrically resistive layer, thereby energizing a portion of the electrically resistive layer so that the energized portion generates Joule heat for softening said ink material on said energized portion and transferring the softened ink material onto said recording medium, characterized in that at least part of said contact portion (8) of each said recording electrode (7,9) consists essentially of an electrically conductive material which has a major component which is a metal silicide; at least one of the metals chromium, titanium, tantalum, zirconium, hafnium and niobium; at least one alloy which contains at least one of said metals; or at least one metal compound which contains at least one of said metals.
Claim 3
Dependent Claim
36 words
A printing apparatus according to claim l, wherein each of said recording electrodes (7;9) consists essentially of an electrically conductive material which has a major component consisting of at least one of chromium, titanium and tantalum.
Claim 4
Dependent Claim
50 words
A printing apparatus according to claim 1, wherein each of said recording electrodes (7;9) consists essentially of an electrically conductive material which has a major component consisting of at least one of: molybdenum chromium alloy; a molybdenum chromium compound; molybdenum silicide; tungsten silicide; chromium silicide; titanium silicide; and tantalum silicide.
Claim 5
Dependent Claim
28 words
A printing apparatus according to any one of claims 1 to 3, wherein said substrate (6) of said printing head consists of a glass ceramic which includes mica.
Claim 6
Dependent Claim
29 words
A printing apparatus according to any one of claims 1 to 4, wherein the wear resistance of said substrate (6) is lower than that of said recording electrodes (7;9).
Claim 7
Dependent Claim
26 words
A printing apparatus according to any one of claims 1 to 5 wherein said substrate has a hardness lower than that of said recording electrodes (7;9).
Claim 8
Dependent Claim
27 words
A printing apparatus according to any one of claims 1 to 6 wherein said substrate (6) has a hardness lower than 1500 Kg/mm 2 of Knoop hardness.
Claim 9
Dependent Claim
23 words
A printing apparatus according to any one of claims 1 to 7 wherein each of said electrodes (7) consists of a single layer.
Claim 10
Dependent Claim
29 words
A printing apparatus according to any one of claims I to 7 wherein each of said electrodes (9) consists of a plurality of layers (9a,9b) superposed on each other.
Claim 11
Dependent Claim
39 words
A printing apparatus according to claim 9 wherein one or more of said layers (9a,9b) which provides a part of said contact portion consists of an electrically conductive material other than said electrically conductive material defined in claim 1.
Claim 12
Dependent Claim
59 words
A printing apparatus according to any one of claims 1 to 10 wherein said plurality of electrodes consist of a plurality of high-potential electrodes, and a plurality of low-potential electrodes, said high-potential and- low-potential electrodes being disposed alternately in a spaced apart relation with each other, in a direction perpendicular to a direction of feed of said ink film.
Claim 13
Dependent Claim
29 words
A printing apparatus according to any one of claims 1 to 10 wherein said plurality of electrodes consist of a plurality of low-potential electrodes, and a common high-potential electrode.
Claim 14
Dependent Claim
29 words
A printing apparatus according to any one of claims 1 to 10 wherein said plurality of electrodes consist of a plurality of high-potential electrodes, and a common low-potential electrode.
Claim 15
Dependent Claim
28 words
A printing apparatus according to any one of the preceding claims, wherein said electrodes (7;9) are covered, except at their contact portions, by an electrically insulating protective layer.
References Cited (Backward Citations)
No citation records indexed.
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