Patent EP0300634A1 successfully refreshed from Google Patents.
EP0300634A1
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EP
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Thermal inkjet pen temperature control
Assignee: HP Inc
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Filing: 1988-07-06
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Granted: —
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Expires: 2008-07-06
Abstract
Abstract Thermal inkjet printhead temperature control is provided in a temperature control system responsive to printhead temperature, which in the presence of printhead overheating selectively causes the printhead to stand idle, or, if multiple nozzles are available, shifts to a nozzle which is not overheated, which in the event a nozzle is unused for some time and the dye transport agent may have evaporated leaving a viscous plug in the nozzle employs warm up pulsing and/or nozzle spitting to clear the nozzles, and which when the temperature of the nozzle is below acceptable printing temperatures, nozzle pulsing for warm up and/or nozzle spitting to clear the nozzles, all such decisions and actions being provided in advance of beginning a printing operation.
Inventors
- 👤 James C. Smith
- 👤 Hatem E. Mostafa
- 👤 William J. Walsh
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 16:29
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/04; B41J2/045; B41J2/04501; B41J2/04515; B41J2/04528; B41J2/04563; B41J2/0458; B41J2/04596; B41J2/04598
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
A temperature control system for a thermal inkjet printer, having a printer carriage drive, a printer carriage movable by said printer carriage drive across a printing zone between sweep limit positions and movable to and from a rest position in response to print commands, and having a thermal inkjet printhead mounted on said carriage, comprising: means including print drive circuits coupled to said thermal inkjet printhead for producing electrical pulses for firing inkdrops from said themal inkjet printhead in said printing zone and for stopping said electrical pulses outside of said printing zone; temperature sensor means for sensing the temperature of said thermal inkjet printhead; and means responsive to said temperature sensor means for controlling said means including print drive circuits to maintain the temperature of said thermal inkjet printhead substantially at a predetermined temperature.
Claim 2
Dependent Claim
135 words
A temperature control system for a thermal inkjet printer, having a printer carriage drive, a printer carriage movable by said printer carriage drive across a printing zone between sweep limit positions and movable to and from a rest position in response to print commands, and having a thermal inkjet printhead mounted on said carriage, comprising: means including print drive circuits coupled to said thermal inkjet printhead for producing electrical pulses for firing inkdrops from said themal inkjet printhead in said printing zone and for stopping said electrical pulses outside of said printing zone; temperature sensor means for sensing the temperature of said thermal inkjet printhead; and means responsive to said temperature sensor means for controlling said means including print drive circuits to maintain the temperature of said thermal inkjet printhead substantially at a predetermined temperature.
Claim 3
Dependent Claim
50 words
The invention according to Claim 1, wherein the last named means comprises: means for controlling said printer carriage drive to stop said printer carriage in a sweep limit position and to dwell therein to permit said thermal inkjet printhead to cool when the temperature thereof is above said predetermined temperature.
Claim 4
Dependent Claim
67 words
The invention according to Claim 1, wherein the last named means comprises: means responsive to a print command as said printer carriage is moved from said rest position by said printer carriage drive for causing said means including print drive circuits to apply electric pulses to said thermal inkjet printhead for firing ink drops when the temperature of said thermal inkjet printhead is below said predetermined temperature.
Claim 5
Dependent Claim
67 words
The invention according to Claim 1, wherein the first named means comprises: a power supply coupled to said print drive circuits and controlled by said means responsive to said temperature sensor means so that power supplied to said print drive circuits is reduced for temperatures of said thermal inkjet printhead above said predetermined temperature and increased for temperatures of said thermal inkjet printhead below said predetermined temperature.
Claim 6
Dependent Claim
61 words
The invention according to Claim 1, comprising: means for counting said electrical pulses; means for computing a pulse rate from said electrical pulses; means for determining a quantity representing the intensity of use, i.e., the use profile of said thermal inkjet printhead from said pulse rate; and means responsive to said quantity for additionally controlling said means including print drive circuits.
Claim 7
Dependent Claim
40 words
The invention according to Claim 1, wherein: said means responsive to said temperature sensor means controls said means including print drive circuits to produce electrical pulses of limited duration to warm said thermal inkjet printhead but not to fire inkdrops.
References Cited (Backward Citations)
US4544931A
Cited
DE3546138A1
Cited
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