Claims
- 1. A printing head for thermally printing on a recording medium by using an electrically resistive layer provided on a film or ribbon or on said recording medium, said printing head comprising:
- a ceramic substrate, and a plurality of recording electrodes disposed on said substrate, each of said plurality of electrodes including an electrical contact portion for electrically contacting said electrically resistive layer of said film, ribbon or recording medium, each electrode cooperating with another of said electrodes to apply a voltage to said electrically resistive layer, thereby energizing a portion of the electrically resistive layer so that the energized portion of said electrically resistive layer generates Joule heat;
- said substrate comprising a material having a low wear resistance; and
- the electrical contact portion of each recording electrode having a thickness of at least one micron, and consisting essentially of an electrically conductive material for resisting oxidation deterioration of the electrodes, said electrically conductive material being selected from the group consisting of nitrides each of which contains at least one element selected from the group consisting of chromium, titanium, tantalum, zirconium and niobium.
- 2. A printing head according to claim 1, wherein said substrate and said each recording electrode are heat-treated at a temperature between 400.degree. C. and 1000.degree. C. in a non-oxidizing atmosphere containing nitrogen, to thereby provide said electrical contact portion consisting essentially of one of said nitrides.
- 3. A printing head according to claim 2, wherein said temperature ranges from 800.degree. C. to 1000.degree. C.
- 4. A printing head according to claim 2, wherein said non-oxidizing atmosphere consists essentially of a gas selected from the group consisting of: N.sub.2 atmosphere; N.sub.2 +H.sub.2 atmosphere; and N.sub.2 +H.sub.2 +H.sub.2 O atmosphere.
- 5. A printing head according to claim 2, wherein said non-oxidizing atmosphere consists essentially of an NH.sub.3 atmosphere.
- 6. A printing head according to claim 1, wherein said substrate and said each recording electrode are formed by firing said material having a low wear resistance and said electrically conductive material at a temperature between 400.degree. C. and 1000.degree. C. in a non-oxidizing atmosphere containing nitrogen, to thereby provide said electrical contact portion consisting essentially of one of said nitrides.
- 7. A printing head according to claim 1, wherein said electrical contact portion of said each recording electrode is coated with an electroplating or electroless plating layer.
- 8. A printing head according to claim 7, wherein said plating layer consists essentially of Cu.
- 9. A printing head according to claim 7, wherein said plating layer consists essentially of a material selected from the group consisting of Ni, Ni-B, Ni-P, and Au.
- 10. A printing head according to claim 1, wherein said substrate of said printing head is formed of a glass ceramic which includes mica.
- 11. A printing head according to claim 1, wherein the wear resistance of said substrate is lower than that of said recording electrodes.
- 12. A printing head according to claim 1, wherein said substrate has a hardness lower than that of said recording electrodes.
- 13. A printing head according to claim 1, wherein said substrate has a Knoop hardness lower than 1500 Kg/mm.sup.2.
- 14. A printing head according to claim 1, wherein each of said electrodes consists essentially of a single layer.
- 15. A printing head according to claim 1, wherein each of said electrodes consists essentially of a plurality of layers superposed on each other.
- 16. A printing head according to claim 1, 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 the direction of feed of said ink film.
- 17. A printing head according to claim 1, wherein said plurality of electrodes consist of a plurality of low-potential electrodes, and a common high-potential electrode.
- 18. A printing head according to claim 1, wherein said plurality of electrodes consist of a plurality of high-potential electrodes, and a common low-potential electrode.
- 19. A printing head according to claim 1, wherein said electrically conductive material is a nitride which contains chromium.
Priority Claims (1)
Number |
Date |
Country |
Kind |
61-82480 |
Apr 1986 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 251,849, filed Oct. 3, 1988, now abandoned, which in turn is a continuation-in-part of application Ser. No. 033,730, filed Apr. 3, 1987, abandoned.
US Referenced Citations (5)
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Non-Patent Literature Citations (2)
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Continuations (1)
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Number |
Date |
Country |
Parent |
251849 |
Oct 1988 |
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Continuation in Parts (1)
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Number |
Date |
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Parent |
33730 |
Apr 1987 |
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