IMAGE FORMING APPARATUS

• US 20200133359A1
• Filed: 10/26/2018
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Abandoned Application

• Current Assignee: Toshiba Tec Corporation (Toshiba Corporation)
• Original Assignee: Toshiba Tec Corporation (Toshiba Corporation)
• Inventors: HASEGAWA, Satoshi
• Application Number:
  US16/172,469
• Publication Number:
  US 20200133359A1
• Time in Patent Office: Days
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24

Abstract

An image forming apparatus includes a power supply key, a latch switch and a processor. The latch switch is connected to a signal line of the power supply key and configured to maintain a state of a power supply in response to pressing on the power supply key when the latch switch is in an ON state. The processor is configured to perform control to set the state of the latch switch to an OFF state in a first mode corresponding to a state in which the image forming apparatus is not connected with an external device, and to set the state of the latch switch to the ON state in a second mode corresponding to a state in which the image forming apparatus is connected with the external device.

Claims

1. An image forming apparatus, comprising:

a power supply key;

a latch switch connected to a signal line of the power supply key and configured to maintain a state of a power supply in response to pressing on the power supply key when the latch switch is in an ON state; and

a processor configured to perform control to set the state of the latch switch to an OFF state in a first mode, the first mode corresponding to a state in which the image forming apparatus is not connected with an external device, and to set the state of the latch switch to the ON state in a second mode, the second mode corresponding to a state in which the image forming apparatus is connected with the external device.

2. The image forming apparatus according to claim 1, further comprising:

a first circuit, connected with a signal line of the latch switch, to which power from a first DC power supply relating to the first mode is supplied in response to the pressing on the power supply key or in response to the ON state of the latch switch, and configured to raise a second DC power supply relating to the second mode based on supply of power from the first DC power supply; and

a second circuit configured to operate based on supply of power from the second DC power supply, and to raise a third DC power supply relating to startup of the processor.

3. The image forming apparatus according to claim 2, wherein

the second DC power supply is higher in power than the first DC power supply, and the third DC power supply is higher in power than the second DC power supply.

4. The image forming apparatus according to claim 2, wherein

the first circuit is configured to raise the second DC power supply based on the supply of power from the first DC power supply according to the ON state of the latch switch in response to recovery of an AC power supply after the AC power supply is turned off,

the second circuit is configured to raise the third DC power supply based on the supply of power from the second DC power supply, and

the processor is started based on supply of power from the third DC power supply.

5. The image forming apparatus according to claim 4, wherein

the processor is configured to switch an operation mode of the processor to either the first mode or the second mode based on startup in response to recovery of the AC power supply after the AC power supply is turned off.

6. The image forming apparatus according to claim 4, wherein

the processor is configured to:

perform control to set the latch switch to the OFF state from the ON state based on startup in response to recovery of the AC power supply after the AC power supply is turned off,

determine whether the image forming apparatus is connected with or not connected with the external device,

perform control to switch the state of the latch switch from the OFF state to the ON state and lower the third DC power supply according to a determination result indicating that the image forming apparatus is connected with the external device, and

perform control to maintain the state of the latch switch in the OFF state and lower the second DC power supply and the third DC power according to a determination result indicating that the image forming apparatus is not connected with the external device.

7. The image forming apparatus according to claim 6, wherein

the second DC power supply is higher in power than the first DC power supply, and the third DC power supply is higher in power than the second DC power supply.

8. A method of operating an image forming apparatus including a power supply key and a latch switch connected to a signal line of the power supply key, the method comprising:

maintaining a state of a power supply in response to pressing on the power supply key when the latch switch is in an ON state;

performing control to set the state of the latch switch to an OFF state in a first mode, the first mode corresponding to a state in which the image forming apparatus is not connected with an external device; and

setting the state of the latch switch to the ON state in a second mode, the second mode corresponding to a state in which the image forming apparatus is connected with the external device.

9. The method according to claim 8, further comprising:

supplying power from a first DC power supply relating to the first mode to a first circuit, connected with a signal line of the latch switch, in response to the pressing on the power supply key or in response to the ON state of the latch switch;

raising a second DC power supply relating to the second mode based on supply of power from the first DC power supply;

operating a second circuit based on supply of power from the second DC power supply; and

raising a third DC power supply relating to startup of a processor performing the control to set the state of the latch switch.

10. The method according to claim 9, wherein

the second DC power supply is higher in power than the first DC power supply, and the third DC power supply is higher in power than the second DC power supply.

11. The method to claim 9, further comprising:

raising the second DC power supply based on the supply of power from the first DC power supply according to the ON state of the latch switch in response to recovery of an AC power supply after the AC power supply is turned off,

raising the third DC power supply based on the supply of power from the second DC power supply, and

starting the processor based on supply of power from the third DC power supply.

12. The method according to claim 11, further comprising:

switching an operation mode of the processor to either the first mode or the second mode based on startup in response to recovery of the AC power supply after the AC power supply is turned off.

13. The method according to claim 11, further comprising:

performing control to set the latch switch to the OFF state from the ON state based on startup in response to recovery of the AC power supply after the AC power supply is turned off,

determining whether the image forming apparatus is connected with or not connected with the external device;

performing control to switch the state of the latch switch from the OFF state to the ON state and lower the third DC power supply according to a determination result indicating that the image forming apparatus is connected with the external device; and

performing control to maintain the state of the latch switch in the OFF state and lower the second DC power supply and the third DC power according to a determination result indicating that the image forming apparatus is not connected with the external device.

14. The method according to claim 13, wherein

the second DC power supply is higher in power than the first DC power supply, and the third DC power supply is higher in power than the second DC power supply.