Power supply apparatus, printer, and control method

• US 10,245,862 B2
• Filed: 05/23/2016
• Issued: 04/02/2019
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ogasawara, Yasufumi, Sakai, Takashi, Okita, Hisao, Ishikawa, Shinya, Oshika, Toru
• Primary Examiner(s): Luu, Matthew
• Assistant Examiner(s): Kemathe, Lily
• Application Number:
  US15/162,335
• Publication Number:
  US 20160347097A1
• Time in Patent Office: 1,044 Days
• CPC Class Codes: B41J 23/00 Power drives for actions or mechanisms B41J9/00 , B41J19/305 take precedence
• CPC Class Codes: B60L 2270/20 Inrush current reduction, i.e. avoiding high currents when connecting the battery
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 7/02 Conversion of ac power input into dc power output without possibility of reversal
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A power supply apparatus includes a power source unit configured to supply electric power to an electric load, a capacitor connected to a power supply line extending from the power supply unit to the electric load, a charge circuit configured to charge the capacitor while restricting a current value of the electric power supplied from the power source unit, a specifying unit configured to specify a voltage value of the capacitor, a first determination unit configured to determine whether the charge of the capacitor is completed in accordance with the voltage specified by the specifying unit, and a second determination unit configured to determine whether the voltage specified by the specifying unit is equal to or smaller than an error threshold value after the first determination unit determines that the charge of the capacitor is completed.

Claims

1. A power supply apparatus comprising:

a power source circuit configured to supply electric power to an electric load;

a capacitor connected to a power supply line extending from the power source circuit to the electric load and configured to supply electric power to the electric load;

a charge circuit configured to charge the capacitor by supplying a current that is powered by the electric power supplied from the power source circuit;

a detection circuit configured to detect a voltage value of the capacitor; and

a controller configured to, in a case where the detected voltage value of the capacitor reaches a first threshold value,

control the charge circuit to change a current value of the current of the charge circuit from a first current value to a second current value that is smaller than the first current value, wherein the first current value is supplied before the detected voltage value reaches the first threshold value, and wherein the second current value is greater than zero, and

wherein, after the detected voltage value of the capacitor reaches the first threshold value, the controller is further configured to

continually determine, while the second current value is supplied to the capacitor, whether the detected voltage value of the capacitor is smaller than a second threshold value that is smaller than the first threshold value; and

cause a discharge of the capacitor in a case where the controller determines that the detected voltage value of the capacitor is smaller than the second threshold value.

2. The power supply apparatus according to claim 1, wherein the controller is further configured to cause the discharge of the capacitor by causing an increase in a current flow out of the capacitor.

3. The power supply apparatus according to claim 2, wherein the controller is further configured to cause the increase in the current flow out of the capacitor by activating a discharge circuit.

4. The power supply apparatus according to claim 1, wherein the second current value is larger than a natural discharge of the capacitor when connected to the power supply line.

5. The power supply apparatus according to claim 1, wherein, in a case where the controller causes the discharge of the capacitor, the charge circuit and the power source circuit are turned off.

6. The power supply apparatus according to claim 1, wherein, when the capacitor is charged, the charge circuit changes the current value of the current supplied from the charge circuit in accordance with the voltage value detected by the detecting circuit.

7. The power supply apparatus according to claim 6,

wherein the charge circuit changes the current value of the current supplied from the charge circuit such that an amount of generated heat becomes equal to or smaller than an allowable power dissipation of the charge circuit, and

wherein a value for the amount of generated heat is obtained in accordance with (i) a difference between a value of a voltage supplied from the power source circuit and the voltage value of the capacitor detected by the detecting circuit and (ii) the value of the current supplied from the charge circuit.

8. The power supply apparatus according to claim 1, wherein the electric power supplied from the power source circuit when the electric load is to be operated is electric power in which a current value is not restricted.

9. The power supply apparatus according to claim 1, further comprising a discharge circuit configured to perform discharge from the capacitor.

10. The power supply apparatus according to claim 1, further comprising the electric load, wherein the electric load is a print head.

13. The power supply apparatus according to claim 1, wherein the power supply apparatus is configured for a printer.

14. The power supply apparatus according to claim 1, wherein, in a case where the controller determines that the detected voltage value of the capacitor is not smaller than the second threshold value and a condition is met to start an operation, the controller stops determining whether the detected voltage value of the capacitor is smaller than the second threshold value and the controller causes power to be supplied to the electric load from at least one of the power source circuit and the charged capacitor during performance of the operation.

15. The power supply apparatus according to claim 14, wherein, after performance of the operation, the controller resumes determining whether the detected voltage value of the capacitor is smaller than the second threshold value.

11. A printer comprising:

a print head, and

a power supply apparatus, wherein the power supply apparatus includes;

a power source circuit configured to supply electric power to the print head,

a capacitor connected to a power supply line extending from the power source circuit to the print head and configured to supply electric power to the print head,

a charge circuit configured to charge the capacitor by supplying a current that is powered by the electric power supplied from the power source circuit,

a detection circuit configured to detect a voltage value of the capacitor, and

a controller configured to, in a case where the detected voltage value of the capacitor reaches a first threshold value, control the charge circuit to change a current value of the current of the charge circuit from a first current value to a second current value that is smaller than the first current value,

wherein the first current value is supplied before the detected voltage value reaches the first threshold value,

wherein the second current value is greater than zero, and

wherein, after the detected voltage value of the capacitor reaches the first threshold value, the controller is further configured to

continually determine, while the second current value is supplied to the capacitor, whether the detected voltage value of the capacitor is smaller than a second threshold value that is smaller than the first threshold value, and

cause a discharge of the capacitor in a case where the controller determines that the detected voltage value of the capacitor is smaller than the second threshold value.

12. A method for controlling a power supply apparatus having a power source circuit configured to supply electric power to an electric load, a capacitor connected to a power supply line extending from the power source circuit to the electric load and configured to supply electric power to the electric load, and a charge circuit configured to charge the capacitor by supplying a current that is powered by the electric power supplied from the power source circuit, the method comprising:

detecting a voltage value of the capacitor;

determining whether the voltage value of the capacitor has reached a first threshold value;

in a case where the voltage value of the capacitor has reached the first threshold value, controlling the charge circuit to change a current value of a current of the charge circuit from a first current value to a second current value that is smaller than the first current value, wherein the first current value is supplied before the detected voltage value reaches the first threshold value, and wherein the second current value is greater than zero; and

the detected voltage value of the capacitor reaches the first threshold value,

continually determining, while the second current value is supplied to the capacitor, whether the detected voltage value of the capacitor is smaller than a second threshold value that is smaller than the first threshold value, and

causing a discharge of the capacitor in a case where the detected voltage value of the capacitor is smaller than the second threshold value.