Mitigating effects of crosstalk in an inkjet head

Patent metadata

Field	Value
Publication number	US-9751302-B1
Application number	US-201615058085-A
Country	US
Kind code	B1
Filing date	Mar 1, 2016
Priority date	Mar 1, 2016
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

Systems and methods of mitigating the effects of crosstalk in an inkjet head. An inkjet head has ink channels that jet droplets of a liquid material using piezoelectric actuators. Drive waveforms provided to the piezoelectric actuators include jetting pulses that cause activation of the piezoelectric actuators to jet the droplets from the ink channels. When crosstalk exists between the ink channels of the inkjet head due to the piezoelectric actuators, the amplitude of the jetting pulses are modified to mitigate the crosstalk between the ink channels.

First claim

We claim:

1. A system comprising:
an inkjet head comprising a plurality of ink channels in a row that jet droplets of a liquid material onto a medium using piezoelectric actuators;
a jetting pulse generator that selectively provides drive waveforms to the piezoelectric actuators in the row, wherein the drive waveforms include jetting pulses that cause activation of the piezoelectric actuators to jet the droplets from the ink channels; and
a compensation controller that identifies a crosstalk value indicating a type of crosstalk between the ink channels in the row for the inkjet head, and modifies the drive waveforms output by the jetting pulse generator and selectively provided to the piezoelectric actuators to increase an amplitude of each of the jetting pulses or decrease the amplitude of each of the jetting pulses based on the type of crosstalk.

2. The system of claim 1 wherein:
the compensation controller increases the amplitude of each of the jetting pulses responsive to negative crosstalk between the ink channels.

3. The system of claim 2 wherein:
the compensation controller adjusts a leading edge of the jetting pulses to exceed a target jetting voltage.

4. The system of claim 1 wherein:
the compensation controller decreases the amplitude of each of the jetting pulses responsive to positive crosstalk between the ink channels.

5. The system of claim 4 wherein:
the compensation controller adjusts a leading edge of the jetting pulses below a target jetting voltage.

6. The system of claim 1 further comprising:
a droplet analyzer;
the jetting pulse generator provides the drive waveforms to the piezoelectric actuators in adjacent ink channels; and
the droplet analyzer measures jetting characteristics of the droplets jetted from the adjacent ink channels, and compares the jetting characteristics of the droplets to target characteristics to identify the type of crosstalk.

7. The system of claim 6 wherein:
the jetting characteristics comprise a velocity of the droplets.

8. The system of claim 6 wherein:
the jetting characteristics comprise a mass of the droplets.

9. A method of mitigating crosstalk in an inkjet head, wherein the inkjet head includes a plurality of ink channels in a row that jet droplets of a liquid material onto a medium using piezoelectric actuators, the method comprising:
selectively providing drive waveforms to the piezoelectric actuators in the row with a jetting pulse generator, wherein the drive waveforms include jetting pulses that cause activation of the piezoelectric actuators to jet the droplets from the ink channels;
identifying a crosstalk value indicating a type of crosstalk between the ink channels in the row for the inkjet head; and
modifying the drive waveforms output by the jetting pulse generator and selectively provided to the piezoelectric actuators to increase an amplitude of each of the jetting pulses or decrease the amplitude of each of the jetting pulses based on the type of crosstalk.

10. The method of claim 9 wherein modifying the drive waveforms comprises:
increasing the amplitude of each of the jetting pulses responsive to negative crosstalk between the ink channels.

11. The method of claim 10 wherein increasing the amplitude of the jetting pulses comprises:
adjusting a leading edge of the jetting pulses to exceed a target jetting voltage.

12. The method of claim 9 wherein modifying the drive waveforms comprises:
decreasing the amplitude of each of the jetting pulses responsive to positive crosstalk between the ink channels.

13. The method of claim 12 wherein decreasing the amplitude of the jetting pulses comprises:
adjusting a leading edge of the jetting pulses below a target jetting voltage.

14. The method of claim 9 further comprising:
identifying the crosstalk between the ink channels in the inkjet head by:
providing the drive waveforms to the piezoelectric actuators in adjacent ink channels;
measuring jetting characteristics of the droplets jetted from the adjacent ink channels; and
comparing the jetting characteristics of the droplets to target characteristics to identify the type of crosstalk.

15. The method of claim 14 wherein:
the jetting characteristics comprise a velocity of the droplets.

16. The method of claim 14 wherein:
the jetting characteristics comprise a mass of the droplets.

17. A system comprising:
a drive circuit that connects to an inkjet head having ink channels in a row that jet droplets of a liquid material onto a medium using piezoelectric actuators;
the drive circuit selectively provides drive waveforms to the piezoelectric actuators, wherein the drive waveforms include jetting pulses that cause activation of the piezoelectric actuators to jet the droplets from the ink channels; and
the drive circuit identifies a crosstalk value indicating a type of crosstalk between the ink channels in the row for the inkjet head, and modifies the drive waveforms selectively provided to the piezoelectric actuators to increase an amplitude of each of the jetting pulses or decrease the amplitude of each of the jetting pulses based on the type of crosstalk.

18. The system of claim 17 wherein:
the drive circuit increases the amplitude of the jetting pulses responsive to negative crosstalk between the ink channels.

19. The system of claim 17 wherein:
the drive circuit decreases the amplitude of the jetting pulses responsive to positive crosstalk between the ink channels.

Assignees

• Nishimura Hiroshi
• Nobumori Shogo
• Ricoh Co Ltd

Inventors

• Nishimura Hiroshi
• Nobumori Shogo

Classifications

• B41J2/0459

  Height of the driving signal being adjusted · CPC title

• B41J2/04596

  Non-ejecting pulses · CPC title

• B41J2/04586

  controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type · CPC title

• B41J2/04588

  using a specific waveform · CPC title

• B41J2/04525 Primary

  reducing occurrence of cross talk · CPC title