System and method for controlling energy characteristics of an inkjet printhead

• US 6,575,548 B1
• Filed: 02/19/1999
• Issued: 06/10/2003
• Est. Priority Date: 10/28/1997
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Ross, Graham, Corrigan, George H. III, Wade, John M
• Primary Examiner(s): HALLACHER, CRAIG ALAN
• Application Number:
  US09/253,447
• Time in Patent Office: 1,572 Days
• Field of Search: 347/9, 347/14, 347/19
• US Class Current: 347/19
• CPC Class Codes: B41J 2/04506 aiming at correcting manufacturing tolerances
• CPC Class Codes: B41J 2/0451 for detecting failure, e.g. clogging, malfunctioning actuator
• CPC Class Codes: B41J 2/04528 aiming at warming up the head
• CPC Class Codes: B41J 2/04541 Specific driving circuit
• CPC Class Codes: B41J 2/04543 Block driving
• CPC Class Codes: B41J 2/04563 detecting head temperature; Ink temperature
• CPC Class Codes: B41J 2/0457 Power supply level being detected or varied
• CPC Class Codes: B41J 2/04573 Timing; Delays
• CPC Class Codes: B41J 2/0458 controlling heads based on heating elements forming bubbles
• CPC Class Codes: B41J 2/04581 controlling heads based on piezoelectric elements
• CPC Class Codes: B41J 2/0459 Height of the driving signal being adjusted
• CPC Class Codes: B41J 2/04591 Width of the driving signal being adjusted
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions

Abstract

This present invention is embodied in a printing system and protocol for providing efficient control of energy characteristics of an inkjet printhead. The printing system includes a controller, a power supply and a printhead assembly having a memory device and a distributive processor integrated with an ink driver. The distributive processor maintains energy characteristics of the printhead assembly within preprogrammed acceptable boundaries.

Claims

1. An inkjet printing apparatus forming at least a portion of a printing system, the printing system including a printer portion including a system controller that provides printing system control signals, the printing apparatus comprising:

a printhead assembly mechanically and electrically coupled to the printer portion and including an integrated energy setpoint register that stores an amount of energy to be delivered to emit ink with a low temperature setpoint register that corresponds to a minimum acceptable operating temperature and a fault setpoint register that corresponds to a maximum acceptable operating temperature.

3. The inkjet printing apparatus of claim 1, further comprising a plurality of ink drop generators that emit the ink in response to the control signals and an integrated memory device with calibration information stored therein, wherein the system controller accesses the memory device and uses the calibration information for performing tests.

4. The inkjet printing apparatus of claim 3, wherein the tests are used to determine optimal operating conditions for the printing apparatus and for storing and using the optimal operating conditions.

5. The inkjet printing apparatus of claim 3, wherein performing tests further comprises observing a pulse width truncation flag for each group.

6. The inkjet printing apparatus of claim 3, wherein the drop generators are grouped into sections and further comprising a device for determining a maximum operating voltage by varying the operating voltage such that none of the sections truncate.

7. The printing apparatus as set forth in claim 4, wherein using the operating conditions comprises increasing a printer power supply voltage in small incremental steps and firing the resistors at each step until a group flag shows truncation.

9. The inkjet printing apparatus of claim 3, further comprising a substrate having a front surface and an opposing back surface and ink ejection elements being formed on the front surface.

2. An inkjet printing apparatus forming at least a portion of a printing system, the printing system including a printhead assembly, the printhead assembly including a plurality of drop generators, the printing apparatus comprising:

an energy setpoint register integrated with the printhead assembly and including a low temperature setpoint register that corresponds to a minimum acceptable operating temperature and a fault setpoint register that corresponds to a maximum acceptable operating temperature; and

a printer portion adapted to receive the printhead assembly and including a system controller configured to provide data to the energy setpoint register, the data indicative of an amount of energy to be delivered to the plurality of drop generators.

8. The inkjet printing apparatus of claim 2, further comprising:

a media moving mechanism;

a printhead support mechanism that supports the printhead assembly in relation to the media moving mechanism; and

an ink supply for providing ink to the printhead.

10. The inkjet printing apparatus of claim 2, further comprising an integrated memory device with calibration information stored therein, wherein the controller accesses the memory device and uses the calibration information for performing tests.

11. The inkjet printing apparatus of claim 10, wherein the tests are used to determine optimal operating conditions for the printing apparatus and for storing and using the optimal operating conditions.

12. The printing apparatus as set forth in claim 11, wherein using the operating conditions comprises increasing a printer power supply voltage in small incremental steps and firing the resistors at each step until a group flag shows truncation.

13. A printing method comprising:

corresponding a low temperature setpoint register of an energy setpoint register to a minimum acceptable operating temperature;

corresponding a fault setpoint register of the energy setpoint register to a maximum acceptable operating temperature;

configuring a controller to automatically provide data to the energy setpoint register; and

automatically using the data to determine an amount of energy to be delivered to a plurality of drop generators.

14. The method of claim 13, further comprising storing calibration information on an integrated memory device and accessing the memory device and using the calibration information for performing tests.

15. The method claim 14, determining optimal operating conditions from the tests for printing, and storing and using the optimal operating conditions.

16. The method of claim 14, wherein performing tests further comprises observing a pulse width truncation flag for each group.

17. The method of claim 15, wherein using the operating conditions comprises increasing a printer power supply voltage in small incremental steps and firing the drop generators at each step until a group flag shows truncation.

18. The method of claim 13, wherein the drop generators are defined by sections, each section having electrical components with associated electrical characteristics.

19. The method of claim 18, further comprising:

selecting a testing range;

measuring the electrical characteristics of the electrical components over the testing range;

calculating an optimal calibration value for the electrical characteristics of each section; and

storing the optimal calibration values.

20. The method of claim 19, further comprising sending a firing pulse to the electrical components, wherein the firing pulse has an associated pulse width, minimum over-energy and maximum over-energy.

21. The method of claim 20, wherein selecting testing range further comprises selecting the pulse width, minimum over-energy and maximum over-energy and measuring the electrical characteristics further comprises measuring a turn-on voltage of each section for the selected pulse width.

22. The method of claim 20 wherein calculating an optimal calibration value further comprises calculating an operating voltage from the selected minimum over-energy.