IP Library Granted Patent US 10,603,921
Granted Patent B2
US 10,603,921 · App. 16/242,039 · Granted Mar 31, 2020

Liquid circulation device and liquid discharge device

Inventor: Kazuhiro Hara (Numazu Shizuoka, JP)
Assignee: TOSHIBA TEC KABUSHIKI KAISHA
B41J2/18B41J2/04548B41J2/04581B41J2/17596H01L41/042B41J2202/12
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Quick Facts
Patent No.
US 10,603,921
App. No.
16/242,039
Granted
Mar 31, 2020
Kind
B2
Abstract

In accordance with an embodiment, a liquid circulation device comprises a plurality of piezoelectric pumps configured to circulate liquid in a replenishing tank to a liquid discharge head through an operation of a piezoelectric actuator thereof; a DC power supply; a switching circuit configured to switch an output of the DC power supply to supply a driving voltage to the piezoelectric actuator of the piezoelectric pump; and a control circuit configured to control the driving voltage by controlling a switching timing of the switching circuit.

Claims (53)

1. A liquid circulation device, comprising:

a plurality of piezoelectric pumps configured to circulate liquid between a replenishing tank and a liquid discharge head through an operation of a piezoelectric actuator thereof;

a DC power supply;

a switching circuit configured to switch an output of the DC power supply to provide a driving voltage to the piezoelectric actuator; and

a control circuit configured to control the driving voltage by controlling a switching timing of the switching circuit.

2. The liquid circulation device according to claim 1 , wherein

the piezoelectric actuator comprises an electrode having a potential that increases in accordance with elapsed time from a start of energization, and

the control circuit controls the driving voltage by controlling a length of energization time of the piezoelectric actuator from the start of the energization to the end of the energization using the switching circuit.

3. The liquid circulation device according to claim 1 , wherein

the switching circuit comprises a full bridge circuit for switching a direction of a driving voltage provided to the piezoelectric actuator.

4. The liquid circulation device according to claim 2 , wherein

the switching circuit comprises a full bridge circuit for switching a direction of a driving voltage provided to the piezoelectric actuator.

5. The liquid circulation device according to claim 3 , wherein

the full bridge circuit comprises four photocouplers.

6. The liquid circulation device according to claim 4 , wherein

the full bridge circuit comprises four photocouplers.

7. A liquid discharge device, comprising:

a liquid discharge head configured to discharge liquid;

a plurality of piezoelectric pumps configured to circulate the liquid between a replenishing tank and the liquid discharge head through an operation of a piezoelectric actuator thereof;

a DC power supply;

a switching circuit configured to switch an output of the DC power supply to provide a driving voltage to the piezoelectric actuator; and

a control circuit configured to control the driving voltage by controlling a switching timing of the switching circuit.

8. The liquid discharge device according to claim 7 , wherein

the piezoelectric actuator comprises an electrode having a potential that increases in accordance with elapsed time from a start of energization, and

the control circuit controls the driving voltage by controlling a length of energization time of the piezoelectric actuator from the start of the energization to the end of the energization using the switching circuit.

9. The liquid discharge device according to claim 7 , wherein

the switching circuit comprises a full bridge circuit for switching a direction of a driving voltage provided to the piezoelectric actuator.

10. The liquid discharge device according to claim 8 , wherein

the switching circuit comprises a full bridge circuit for switching a direction of a driving voltage provided to the piezoelectric actuator.

11. The liquid discharge device according to claim 9 , wherein

the full bridge circuit comprises four photocouplers.

12. The liquid discharge device according to claim 10 , wherein

the full bridge circuit comprises four photocouplers.

13. The liquid discharge device according to claim 7 , wherein

the liquid is inkjet printing ink.

14. The liquid discharge device according to claim 7 , wherein

the liquid discharge device is an inkjet head.

15. A liquid circulation method, comprising:

circulating liquid between a replenishing tank and a liquid discharge head through an operation of a plurality of piezoelectric pumps comprising a piezoelectric actuator;

supplying DC power;

configured to switching an output of the supplied DC power to provide a driving voltage to the piezoelectric actuator using a switching circuit; and

controlling a switching timing of the switching circuit to control the driving voltage.

16. The liquid circulation method according to claim 15 , wherein

the piezoelectric actuator comprises an electrode having a potential that increases in accordance with elapsed time from a start of energization, and further comprising:

controlling a length of energization time of the piezoelectric actuator from the start of the energization to the end of the energization to control the driving voltage.

17. The liquid circulation method according to claim 15 , further comprising:

switching a direction of a driving voltage provided to the piezoelectric actuator using a full bridge circuit.

18. The liquid circulation method according to claim 16 , further comprising:

switching a direction of a driving voltage provided to the piezoelectric actuator using a full bridge circuit.

19. The liquid circulation device according to claim 17 , further comprising:

switching a direction of a driving voltage provided to the piezoelectric actuator using four photocouplers.

20. The liquid circulation device according to claim 18 , further comprising:

switching a direction of a driving voltage provided to the piezoelectric actuator using four photocouplers.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 7, 2024
From: TOSHIBA TEC KABUSHIKI KAISHA
To: RISO TECHNOLOGIES CORPORATION
Reel/Frame 068493/0970 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 8, 2019
From: HARA, KAZUHIRO
To: TOSHIBA TEC KABUSHIKI KAISHA
Reel/Frame 047924/0965 →
Priority Claims (1)
JP 2018-024793 · Feb 15, 2018 · national
Continuity (1)
Related Publication 20190248150A1 · Aug 15, 2019
Cited By (1)
US 12,233,432