Thermal sensing fluid ejection assembly and method

Patent metadata

Field	Value
Publication number	US-9044942-B2
Application number	US-201013818421-A
Country	US
Kind code	B2
Filing date	Sep 30, 2010
Priority date	Sep 30, 2010
Publication date	Jun 2, 2015
Grant date	Jun 2, 2015

Abstract

A fluid ejection assembly includes a fluid slot formed in a die. The assembly also includes a nozzle column is formed along a side of the fluid slot. The assembly also includes a pair of thermal sensors to measure die temperature at the middle of the nozzle column and at a first end of the nozzle column.

First claim

What is claimed is:

1. A fluid ejection assembly comprising:
a pair of fluid slots formed in a die, the pair of slots forming a rib with a first end, a second end, and a center between the first and second ends;
a first column of nozzles disposed on and along a side of the rib;
a pair of thermal sensors located on the rib, the pair of thermal sensors comprising a first thermal sensor located on the center of the rib; and
a heater located on the rib, wherein the heater is in addition to any firing resistors.

2. The fluid ejection assembly of claim 1 , wherein the heater is located at the first end of the rib.

3. The fluid ejection assembly of claim 1 , wherein the heater is located at the center of the rib.

4. The fluid ejection assembly of claim 1 , further comprising a third thermal sensor located at the second end of the rib.

5. The fluid ejection assembly of claim 4 , further comprising a heater located on the rib, wherein the heater is in addition to any firing resistors.

6. The fluid ejection assembly of claim 5 , wherein the heater is located on the center of the rib.

7. The fluid ejection assembly of claim 5 , wherein the heater comprises a plurality of heaters.

8. The fluid ejection assembly of claim 7 , wherein one of said plurality of heaters is located at the first end of the rib and a second of the plurality of heaters is located at the second end of the rib.

9. The fluid ejection assembly of claim 8 , wherein one of the plurality of heaters is located on the center of the rib.

10. The fluid ejection assembly of claim 1 , wherein a thermal control circuit is located on the rib.

11. The fluid ejection assembly of claim 1 , wherein the pair of thermal sensors are configured to generate a control signal for the heater.

12. The fluid ejection assembly of claim 11 , wherein logic to generate the control signal for heater is located on the rib.

13. The fluid ejection assembly of claim 1 , further comprising a second rib with a second column of nozzles and a fourth thermal sensor, wherein output of a thermal sensor on the first rib and output of the fourth thermal sensor on the second rib are used to generate a control signal for the heater on the first rib.

14. A thermal inkjet printing device comprising:
a fluid ejection die having a fluid supply slot and first and second columns of nozzles to eject fluid drops; and
a heating system disposed on the die to maintain a temperature profile across a surface of the die through selective application of heat to different areas of the die in response to temperature data sensed at different areas of the die, the heating system comprising a plurality of sensors and a plurality of heaters,
wherein the heating system compensates for thermal gradients both parallel to and not parallel to the nozzle columns.

15. A thermal inkjet printing device as in claim 14 , wherein the heating system further comprises a heater located at the center of the die, wherein the heater is in addition to any firing resistors.

16. A thermal inkjet printing device as in claim 14 , wherein heat applied in an area of the die is applied by turning a heater on and off with a duty cycle proportional to a temperature difference between two thermal sensors on the die.

17. A thermal inkjet printing device as in claim 14 , further comprising a second column of nozzles parallel to the first column of nozzles, wherein the heating system reduces variation in temperature between the first and second columns of nozzles.

18. A thermal inkjet printing device comprising:
a die with a first rib and a second rib, each rib being defined by a pair of slots;
a first thermal sensor located on the first rib;
a second thermal sensor located on the second rib;
a heater located on the first rib;
a control signal to drive the heater based on a difference in temperature between the first and second thermal sensors.

19. A thermal inkjet printing device as in claim 18 , wherein the heater is in addition to any firing resistors.

Assignees

• Browning Robert N K
• Gardner James
• Martin Eric
• Van Brocklin Andrew L
• Hunter Mark
• Hewlett Packard Development Co

Inventors

• Browning Robert N K
• Gardner James
• Martin Eric
• Van Brocklin Andrew L
• Hunter Mark

Classifications

• B41J2/04528

  aiming at warming up the head · CPC title

• B41J2/135 Primary

  Nozzles · CPC title

• B41J2/0458

  controlling heads based on heating elements forming bubbles · CPC title

• B41J2/14153

  Structures including a sensor · CPC title

• B41J2/04563

  detecting head temperature; Ink temperature · CPC title