Patent EP0369347A2 successfully refreshed from Google Patents.
EP0369347A2
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Thermal print head
Assignee: Casio Computer Co Ltd
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Filing: 1989-11-10
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Granted: —
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Expires: 2009-11-10
Abstract
Abstract Disclosed is a thermal print head (1) in which heating resistance elements (14) are arranged with high density. The thermal print head comprises a head substrate (10), formed of a single-crystal silicon wafer, and a print driver circuit element (3, 4). The print driver circuit element (3, 4), which is formed by doping the head substrate (10) directly with an impurity, is composed of an MOS-FET. A FET used to form the single-crystal silicon substrate (10) has high electrical mobility, and serves to improve the operating speed of the thermal print head (1). Each heating resistance element (14), whose base material is polycrystalline silicon, is adjusted to a predetermined resistance value by being subjected to diffusion of an impurity. The resistance elements (14) are formed on a protuberance (12) which is formed on the head substrate (10). Thus, the portion of an insulating protective film (15) which corresponds to the protuberance (12) projects outward from the rest, thereby ensuring contact with a printing sheet. An earthing diode (16, 17) or laminate structure is used for an earth line of each heating resistance elements (14) so that the resistance element (14) is situated close to a side edge portion of the head substrate (10).
Inventors
- 👤 Takeshi C/O Pat. Dep. Development Div Wakabayashi
- 👤 Tsuneo C/O Pat. Dep. Development Division Ochi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 18:51
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/335; B41J2/33555; B41J2/3357; B41J2/3359
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
110 words
A thermal print head comprising: a single-crystal semiconductor substrate (10); a print driver circuit element (3, 4, 5) formed by implanting an impurity into a predetermined region of said semiconductor substrate (10); a polycrystalline silicon layer (14) formed on said semiconductor substrate (10) and including a low resistance region (A) for heating; a thin film conductor (24, 28) for wiring, said conductor (24, 28) connecting said print driver circuit element (3, 4) and said polycrystalline silicon layer (14); an external connecting terminal (11) connected to said thin film conductor; and an insulating protective film (15) covering said print driver circuit element (3, 4, 5) and said polycrystalline silicon layer (14).
Claim 2
Dependent Claim
80 words
The thermal print head according to claim 1, characterized in that said print driver circuit element (3, 4) includes a shift register element (3a) for successively shifting print data inputted from said external connecting terminal (11), a latch circuit element for latching the data in said shift register element (3a), and a current supply element (4) for supplying electric current for heating to said low resistance region (A) in accordance with the data held in said latch circuit element (3b).
Claim 3
Dependent Claim
31 words
The thermal print head according to claim 2, characterized in that said shift register element (3a), latch circuit element (3b), and current supply element (4) are each formed of an MOS-FET.
Claim 4
Dependent Claim
29 words
The thermal print head according to claim 2, characterized in that said shift register element (3a) and said latch circuit element (3b) are each formed of a complementary MOS-FET.
Claim 5
Dependent Claim
22 words
The thermal print head according to claim 2, characterized in that said current supply element (4) is formed of an N-type-channel MOS-FET.
Claim 6
Dependent Claim
29 words
The thermal print head according to claim 1, characterized in that said external connecting terminal (1) is formed projecting outward from the surface of said insulating protective film (15).
Claim 7
Dependent Claim
139 words
A thermal print head comprising: a single-crystal semiconductor substrate (10); a print driver circuit element (3, 4) formed by implanting an impurity into a predetermined region of said semiconductor substrate (10); a polycrystalline silicon layer (14) formed on said semiconductor substrate (10) and including a low resistance region (A) for heating; a thin film conductor (24, 28) for wiring, said conductor (24, 28) connecting said print driver circuit element (3, 4, 5) and said polycrystalline silicon layer (14); a protuberant layer (12) interposed between said semiconductor substrate (10) and said polycrystalline silicon layer (14); and an insulating protective film (15) covering said print driver circuit element (3, 4, 5) and said polycrystalline silicon layer (14); a part of said insulating protective film which corresponds to said polycrystalline silicon layer (14) projecting from the rest of said protective film (15).
Claim 8
Dependent Claim
24 words
The thermal print head according to claim 7, characterized in that said protuberant layer (12) is formed as part of said semiconductor substrate (10).
Claim 9
Dependent Claim
20 words
The thermal print head according to claim 7, characterized in that said protuberant layer (51) is formed of glass material.
Claim 10
Dependent Claim
123 words
A thermal print head comprising: a single-crystal semiconductor substrate (10); a print driver circuit element (3, 4) formed in a predetermined region of said semiconductor substrate (10); a plurality of polycrystalline silicon elements (50) arranged on said semiconductor substrate (10) in a line; a plurality of selective conductors (52) connecting said print driver circuit element (3, 4) and one end of each corresponding polycrystalline silicon element (50); an insulating layer (15') covering said polycrystalline silicon elements (50) and said selective conductors (52); and a common conductor (54) formed along the arrangement direction of said selective conductors (52), on as portions of said insulating layer (15') which correspond to said selective conductors, for connecting the respective other ends of said polycrystalline silicon elements (50).
Claim 11
Dependent Claim
228 words
A thermal printing apparatus, comprising: a plurality of thermal print heads (1') each including a substrate (10), a print driver circuit element (3, 4, 8) formed in a predetermined region of said substrate (10); a heating region (A) formed of a number of heating elements (50) formed along one side edge of said substrate (10), a glazed layer (51) for heat accumulation formed between said heating elements (50) and said substrate (10), selective conductors (52) connecting said print driver circuit element (3, 4) and one end of each of said heating element (50a), a common conductor (54) connecting the respective other ends (50b) of said heating elements (50), and a plurality of external connecting terminals (11) connected to said print driver circuit element (3,4); a supporting substrate (61) having a bearing surface carrying said thermal print heads (1') in two lines; and bonding means for bonding said thermal print heads (1') to said supporting substrate (61), wherein said thermal print heads (1') are arranged in two offset lines on said supporting substrate (61) so that the heating region (A) of each print head (1') cannot overlap the heating region (A) of each adjacent print head (1') with respect to the longitudinal direction of said supporting substrate (61), and that the respective one side edges of said substrates (61) of each two adjacent print heads (1') face each other.
Claim 12
Dependent Claim
34 words
The thermal printing apparatus according to claim 11, characterized in that an insulating layer (15') is formed on said selective conductors, (52) and said common conductor (54) is formed on said insulating layer (51).
Claim 13
Independent Claim
120 words
A method for manufacturing a thermal print head, comprising the steps of: forming an insulating layer (13) on a semiconductor substrate (10); forming a gate insulating layer (22, 27, 35) after removing an active region of said insulating layer (13); depositing polycrystalline silicon (36) on said insulating layer (13) and said gate insulating layer (22, 27, 35) and forming heating resistance elements (14) and gate electrodes 23 by etching; implanting an impurity at least into said heating resistance elements (14); implanting an impurity at least into an active region of said semiconductor substrate (10); depositing a low resistance metal (28) to form a wiring conductor; and depositing an insulating protective film (15) on the whole surface of the resulting structure.
Claim 14
Independent Claim
155 words
A method for manufacturing a thermal print head, comprising the steps of: providing a semiconductor wafer (10) which is divisible into a plurality of blocks (1); forming a number of heating resistance elements (14) and print driver circuit elements (3, 4) an each of said blocks of said semiconductor wafer (10), said circuit elements (3, 4) being adapted to heat said heating resistance elements (14) in accordance with print data; forming wiring conductors (28) for connecting said heating resistance elements (14) in each of said blocks (1) to said print drive circuit elements (3, 4) and a plurality of external connecting conductors (1); covering the whole surface of said wafer (10) by means of a protective film (15); removing portions of said protective film (15) which correspond to said external connecting conductors (11) in each said block (1); and cutting said wafer (10) into said individual blocks (1), thereby obtaining each individual thermal print head.
References Cited (Backward Citations)
No citation records indexed.
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