Control apparatus and control method of the same

Patent metadata

Field	Value
Publication number	US-9868282-B2
Application number	US-201615153004-A
Country	US
Kind code	B2
Filing date	May 12, 2016
Priority date	May 27, 2015
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A control apparatus including a power supply unit configured to supply electric power, comprises: a capacitor connected to a power supply line extending from the power supply unit to a printhead; a discharge circuit configured to release charge stored in the capacitor; and a control unit configured to control a current value during a discharge operation by the discharge circuit, such that the current value increases as a voltage value of the capacitor decreases.

First claim

What is claimed is:

1. A control apparatus including a power supply unit configured to supply electric power, comprising:
a capacitor connected to a power supply line extending from the power supply unit to a printhead;
a discharge circuit configured to release charge stored in the capacitor; and
a control unit configured to control a current value during a discharge operation by the discharge circuit, such that the current value increases as a voltage value of the capacitor decreases, and
wherein the control unit controls the current value during the discharge operation by the discharge circuit, such that an amount of generated heat of the discharge circuit, which is obtained based on a difference between the voltage value of the capacitor and GND, and the current value during the discharge operation by the discharge circuit, does not exceed an allowable loss of the discharge circuit.

2. The apparatus according to claim 1 , wherein if the voltage value of the capacitor decreases from a first voltage value to a second voltage value, the control unit increases a value of a current flowing through the discharge circuit from a first current value to a second current value, such that an amount of generated heat of the discharge circuit does not exceed an allowable loss of the discharge circuit, and if the voltage value of the capacitor does not decrease from the first voltage value to the second voltage value, the control unit maintains the first current value.

3. The apparatus according to claim 1 , wherein after the discharge operation is complete, the control unit performs switching such that the value of the current flowing through the discharge circuit is restricted to a value smaller than that during the discharge operation.

4. The apparatus according to claim 1 , wherein after the discharge operation is complete, the control unit maintains an operation of the discharge circuit by switching such that a high-impedance state is obtained.

5. The apparatus according to claim 1 , wherein the control unit reduces the current value during the discharge operation by the discharge circuit, such that an amount of generated heat of the discharge circuit, which is obtained from a product of a difference between the voltage value of the capacitor and GND, and the current value during the discharge operation by the discharge circuit, does not exceed an allowable loss of the discharge circuit.

6. The apparatus according to claim 1 , further comprising the printhead.

7. A control method of a control apparatus which comprises:
a power supply unit configured to supply electric power;
a capacitor connected to a power supply line extending from the power supply unit to a printhead; and
a discharge circuit configured to release charge stored in the capacitor,
wherein the control method comprises:
controlling a current value during a discharge operation by the discharge circuit, such that the current value increases as a voltage value of the capacitor decreases, and
wherein the current value is controlled during the discharge operation by the discharge circuit, such that an amount of generated heat of the discharge circuit, which is obtained based on a difference between the voltage value of the capacitor and GND, and the current value during the discharge operation by the discharge circuit, does not exceed an allowable loss of the discharge circuit.

8. The method according to claim 7 , wherein if the voltage value of the capacitor decreases from a first voltage value to a second voltage value, a value of a current flowing through the discharge circuit is increased from a first current value to a second current value, such that an amount of generated heat of the discharge circuit does not exceed an allowable loss of the discharge circuit, and if the voltage value of the capacitor does not decrease from the first voltage value to the second voltage value, the first current value is maintained.

9. The method according to claim 7 , wherein the control method further comprises: after the discharge operation is complete, performing switching such that the value of the current flowing through the discharge circuit is restricted to a value smaller than that during the discharge operation.

10. The method according to claim 7 , wherein the control method further comprises: after the discharge operation is complete, maintaining an operation of the discharge circuit by switching such that a high-impedance state is obtained.

11. The method according to claim 7 , wherein the current value is reduced during the discharge operation by the discharge circuit, such that an amount of generated heat of the discharge circuit, which is obtained from a product of a difference between the voltage value of the capacitor and GND, and the current value during the discharge operation by the discharge circuit, does not exceed an allowable loss of the discharge circuit.

12. The method according to claim 7 , wherein the control apparatus further comprises the printhead.

Assignees

• Canon Kk

Inventors

• Ishikawa Shinya
• Ogasawara Yasufumi
• Okita Hisao
• Sakai Takashi
• Oshika Toru

Classifications

• B41J2/04515 Primary

  preventing overheating · CPC title

• B41J2/0458

  controlling heads based on heating elements forming bubbles · CPC title

• B41J2/04555

  detecting current · CPC title

• B41J2/0452

  reducing demand in current or voltage · CPC title

• B41J29/393 Primary

  Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns} · CPC title