Image forming apparatus, image forming method, and computer-readable storage medium

Patent metadata

Field	Value
Publication number	US-9389573-B2
Application number	US-201514745828-A
Country	US
Kind code	B2
Filing date	Jun 22, 2015
Priority date	Jun 23, 2014
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

An image forming apparatus includes a heat generator configured to generate heat in the image forming apparatus; a converter including a capacitor to convert AC power supplied from an external power supply into DC power for a load unit; a thermoelectric transducer configured to convert the generated heat into DC power for the load unit; a detector configured to detect a voltage of the AC power; and a controller configured to cause the converter to continue supplying the DC power to the load unit when a first elapsed time elapsed since the detected voltage drops below a rated voltage is shorter than a first time period shorter than an upper limit of a period of time over which the capacitor is dischargeable, and cause the thermoelectric transducer to supply the DC power to the load unit when the first elapsed time exceeds the first time period.

First claim

What is claimed is:

1. An image forming apparatus comprising:
a heat generator configured to generate heat depending on operation of the image forming apparatus;
a converter configured to convert AC power supplied from an external power supply into DC power and including a capacitor for smoothing the DC power, the converter being configured to supply the smoothed DC power to a load unit;
a thermoelectric transducer configured to convert the heat generated by the heat generator into DC power and supply the DC power to the load unit in place of the converter;
a detector configured to detect a voltage of the AC power supplied from the external power supply; and
a controller configured to,
when a first elapsed time that is a period of time elapsed since the voltage detected by the detector drops to or below a rated voltage is equal to or shorter than a first time period that is shorter than an upper limit of a period of time over which the capacitor is dischargeable, cause the converter to continue supplying the DC power to the load unit, and
when the first elapsed time exceeds the first time period, cause the thermoelectric transducer to supply the DC power to the load unit.

2. The image forming apparatus according to claim 1 , further comprising a power storage unit, wherein
the controller causes, when a second elapsed time that is a period of time elapsed since the thermoelectric transducer starts supplying DC power to the load unit reaches a second time period that is a period of time over which the thermoelectric transducer can supply DC power to the load unit, the power storage unit in place of the thermoelectric transducer to supply the DC power to the load unit.

3. The image forming apparatus according to claim 2 , wherein the controller sets the first time period of the image forming apparatus operating in a first mode to be longer than the first time period of the image forming apparatus operating in a second mode, load of the load unit in the second mode being larger than load of the load unit in the first mode.

4. The image forming apparatus according to claim 2 , wherein the controller determines an upper limit of a period of time over which the thermoelectric transducer can supply DC power, based on temperature of the heat generator and sets the second time period to the upper limit.

5. The image forming apparatus according to claim 2 , wherein the controller reduces the first time period such that, as the voltage detected by the detector decreases below the rated voltage, the first time period becomes shorter.

6. The image forming apparatus according to claim 1 , wherein
the heat generator generates heat by the AC power supplied from the external power supply, and
the controller turns off, when the voltage detected by the detector drops to or below the rated voltage, the heat generator for a shorter one of a predetermined allowable heat-generation-stop time and the first elapsed time.

7. An image forming method performed in an image forming apparatus that includes a heat generator configured to generate heat depending on operation of the image forming apparatus, a converter configured to convert AC power supplied from an external power supply into DC power and including a capacitor for smoothing the DC power, the converter being configured to supply the smoothed DC power to a load unit, and a thermoelectric transducer configured to convert the heat generated by the heat generator into DC power and supply the DC power to the load unit in place of the converter, the image forming method comprising:
detecting a voltage of the AC power supplied from the external power supply;
causing, when a first elapsed time that is a period of time elapsed since the detected voltage drops to or below a rated voltage is equal to or shorter than a first time period that is shorter than an upper limit of a period of time over which the capacitor is dischargeable, the converter to continue supplying the DC power to the load unit; and
causing, when the first elapsed time exceeds the first time period, the thermoelectric transducer to supply the DC power to the load unit.

8. A non-transitory computer-readable storage medium with an executable program stored thereon and executed by a computer for controlling an image forming apparatus that includes a heat generator configured to generate heat depending on operation of the image forming apparatus, a converter configured to convert AC power supplied from an external power supply into DC power and including a capacitor for smoothing the DC power, the converter being configured to supply the smoothed DC power to a load unit, and a thermoelectric transducer configured to convert the heat generated by the heat generator into DC power and supply the DC power to the load unit in place of the converter, wherein the program instructs the processor to perform:
detecting a voltage of the AC power supplied from the external power supply;
causing, when a first elapsed time that is a period of time elapsed since the detected voltage drops to or below a rated voltage is equal to or shorter than a first time period that is shorter than an upper limit of a period of time over which the capacitor is dischargeable, the converter to continue supplying the DC power to the load unit; and
causing, when the first elapsed time exceeds the first time period, the thermoelectric transducer to supply the DC power to the load unit.

Assignees

• Okada Norikazu
• Shirai Takaaki
• Kasai Takuma
• Maejima Keita
• Yamashita Tomoyuki
• Kubokawa Ryohta
• Tao Satoru
• Ehara Homare
• Ricoh Co Ltd

Inventors

• Okada Norikazu
• Shirai Takaaki
• Kasai Takuma
• Maejima Keita
• Yamashita Tomoyuki
• Kubokawa Ryohta
• Tao Satoru
• Ehara Homare

Classifications

• G03G15/80 Primary

  Details relating to power supplies, circuits boards, electrical connections · CPC title

• G03G15/2039

  with means for controlling the fixing temperature · CPC title