Electronic drive systems and methods

• US 6,419,335 B1
• Filed: 11/24/2000
• Issued: 07/16/2002
• Est. Priority Date: 11/24/2000
• Status: Expired due to Term

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.), Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Crowley, Joseph M., Galambos, Paul C., Gooray, Arthur M., Givler, Richard C., Peter, Frank J., Roller, George J., Zavadil, Kevin R., Lindenfelser, William M.
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): DUDDING, ALFRED E
• Application Number:
  US09/718,480
• Time in Patent Office: 599 Days
• Field of Search: 347/9, 347/54
• US Class Current: 347/9
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2002/043 Electrostatic transducer

Abstract

An electronic drive system applies a drive signal to an electrostatically actuated device such that a resulting electric field has a constant force. In various exemplary embodiments, the electronic drive system applies a drive signal to an electrostatically actuated fluid ejector that has a piston and a faceplate including a nozzle hole. A dielectric fluid to be ejected is supplied between the piston and the faceplate. The drive signal is applied to one of the piston and the faceplate. The drive signal generates an electric field across the fluid between the piston and the faceplate. The electric field causes the piston to be electrostatically attracted towards the faceplate so that a jet or drop of fluid is ejected through the nozzle hole of the faceplate. According to exemplary embodiments, the drive signal is from a constant current source or is reduced over the course of its lifetime. Further, according to various exemplary embodiments, the drive signal is of a suitable high frequency to reduce the potential of electrochemical reactions or electrical breakdown, or both. The drive signal may also be a bi-polar drive signal to reduce the possibility of electrochemical reactions.

Claims

1. An electronic drive method for an electrostatically actuated device having a first electrode on a first part and a second electrode on a second part that is displaceable relative to the first part, the method comprising:

applying an electronic drive signal to at least one of the first electrode and the second electrode; and

generating an electrical field with a constant strength between the first part and the second part as the second part is displaced relative to the first part.

2. The electronic drive method according to claim 1, wherein the electronic drive signal is applied using a constant current source.

3. The electronic drive method according to claim 1, wherein the electronic drive signal is a high frequency signal.

4. The electronic drive method according to claim 1, wherein the electronic drive signal is a bi-polar pulse train.

5. The electronic drive method according to claim 1, wherein a magnitude of an applied voltage of the electronic drive signal is reduced over a pulse interval of the signal.

6. The electronic drive method according to claim 5, wherein the electronic drive signal is a high frequency signal.

7. The electronic drive method according to claim 5, wherein the electronic drive signal is a bi-polar pulse train.

8. The electronic drive method according to claim 5, wherein the applied voltage of the electronic drive signal is used to drive a liquid ejector and is reduced as a function of the displacement of a movable member of the liquid ejector.

9. The electronic drive method according to claim 8, wherein the applied voltage of the electronic drive signal varies directly with the distance of the displacement of the moveable member.

10. The electronic drive method according to claim 8, wherein the applied voltage of the electronic drive signal varies indirectly with the distance of the displacement of the moveable member through a function of time.

11. An electronic drive system for an electrostatically actuated device, comprising:

an electrostatically actuated device having a movable member and a stationary member; and

a drive signal source that applies an electronic drive signal to one of the movable member and the stationary member such that an electrical field with a constant field strength is generated between the movable member and the stationary member.

12. The electronic drive system according to claim 11, wherein the drive signal source comprises a constant current source.

13. The electronic drive system according to claim 11, wherein the drive signal source comprises a high frequency source.

14. The electronic drive system according to claim 11, wherein the drive signal source comprises a bi-polar voltage source.

15. The electronic drive system according to claim 11, wherein the drive signal source comprises a variable voltage source that reduces an applied voltage of the electronic drive signal over a pulse interval of the signal.

16. The electronic drive system according to claim 15, wherein the variable voltage source is a high frequency source.

17. The electronic drive system according to claim 15, wherein the variable voltage source is bi-polar.

18. The electronic drive system according to claim 15, further comprising:

a position sensor that monitors a displacement of the movable member; and

a feedback mechanism connecting the position sensor to the variable voltage source such that the applied voltage of the electronic drive signal is reduced as a function of the displacement of a movable member.

19. The electronic drive system according to claim 15, further comprising:

a timing control communicating with the variable voltage source such that the applied voltage of the electronic drive signal is reduced as a function of time.