EP0454133A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Thermal print head trimming apparatus and method for trimming resistance of a thermal print head
Assignee: Panasonic Holdings Corp
•
Filing: 1991-04-25
•
Granted: —
•
Expires: 2011-04-25
Abstract
Abstract A thermal print head trimming apparatus trims the resistances of heating resistor elements (4a). The apparatus divides the measured resistance data into plural groups by their variation range, and applies pulse signal of high-voltage by a probe electrode (6) to the heating resistor elements (4a) in the plural groups except a group that includes the lowest resistance values of the heating resistor elements (4a). Thereby the whole resistances of the heating resistor elements (4a) in the thermal print head are trimmed to agree with the lowest resistance values.
Inventors
- 👤 Nobuyuki Yoshiike
- 👤 Yoshihiro Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 03:14
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/345; H; H01; H01C; H01C17/00; H01C17/22; H01C17/26; H01C17/265; H01C17/267
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
72 words
A thermal print head trimming apparatus comprising: a power supply circuit for generating voltage of pulse signal for trimming operation; a resistance measuring circuit for measuring resistance of a heating resistor; a movable stage control unit for moving a movable stage holding thereon a thermal print head relatively with a probe electrode; and an operation control unit for controlling said power supply circuit, said resistance measuring circuit and said stage control unit.
Claim 2
Dependent Claim
32 words
A thermal print head trimming apparatus in accordance with claim 1 wherein said operation control unit has a clock circuit for commonly synchronizing said power supply circuit and said stage control unit.
Claim 3
Dependent Claim
64 words
A thermal print head comprising; a common electrode which is formed on a substrate; individual electrodes which are formed on said substrate and have electrode terminals and probe contact portions for contacting a probe electrode; and a heating resistor which are formed on and between said common electrode and said individual electrodes to electrically connect therebetween; a protective layer which covers said heating resistor.
Claim 4
Independent Claim
48 words
A method for trimming resistance of a thermal print head comprising steps of dividing heating resistor elements into predetermined groups based on resistance data of said heating resistor elements, and applying pulse signal of a predetermined voltage to each group for trimming resistance of the thermal print head.
Claim 5
Dependent Claim
48 words
A method for trimming resistance of a thermal print head in accordance with claim 4 wherein said application of pulse signal during a scanning of a probe electrode on individual electrodes formed on a substrate, to electrically connected to said heating resistor elements covered by a protective layer.
Claim 6
Dependent Claim
34 words
A method for trimming resistance of a thermal print head in accordance with claim 5 wherein said application of pulse signal are made at the same time as the scanning on said individual electrodes.
Claim 7
Dependent Claim
50 words
A method for trimming resistance of a thermal print head in accordance with claim 5 wherein said application of pulse signal is made only to those heating resistor elements which have resistance exceeding the predetermined range, after measuring resistance of the whole heating resistor elements of said thermal print head.
Claim 8
Dependent Claim
23 words
A method for trimming resistance of the thermal print head in accordance claim 5 wherein said probe electrode scans in a stepwise scanning.
Claim 9
Dependent Claim
73 words
A method for trimming resistance of the thermal print head in accordance with claim 4 wherein said dividing of said heating resistor elements is made after measuring resistance of the whole heating resistor elements of said thermal print head, said application of pulse signal is made to each group except that which includes the lowest resistance value, thereby to trim the resistance of the whole heating resistor elements to the lowest resistance value.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.