Image forming apparatus

Patent metadata

Field	Value
Publication number	US-10859939-B2
Application number	US-201916727014-A
Country	US
Kind code	B2
Filing date	Dec 26, 2019
Priority date	Apr 9, 2019
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

An image forming apparatus includes an image carrier that carries an image to be transferred onto a recording medium, a charging member in contact with the image carrier, the charging member that charges the image carrier, an erase unit that erases charge on the image carrier, a current detector that detects a current flowing to the charging member; a forming unit that forms a charged region on a surface of the image carrier, and forms an erased region on the surface of the image carrier using the erase unit, and a state acquisition unit that acquires a deterioration state of the charging member based on (i) a first current flowing in response to applying a voltage from the charging member to the erased region and (ii) a second current flowing in response to applying a voltage from the charging member to the charged region.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image carrier configured to carry an image to be transferred onto a recording medium;
a charging member in contact with the image carrier, the charging member configured to charge the image carrier;
an erase unit configured to erase charge on the image carrier;
a current detector configured to detect a current that flows to the charging member;
a forming unit configured to
form a charged region on a surface of the image carrier, and
form an erased region on the surface of the image carrier using the erase unit; and

a state acquisition unit configured to acquire a deterioration state of the charging member based on (i) a first current that flows in response to applying a voltage from the charging member to the erased region and (ii) a second current that flows in response to applying a voltage from the charging member to the charged region.

2. The image forming apparatus according to claim 1 , wherein
the image carrier is configured to rotate,
the erase unit is disposed upstream of the charging member in a direction in which the image carrier rotates, and
the forming unit is configured to form the charged region and the erased region on the surface of the image carrier by charging the image carrier using the charging member and then switching between turning on and turning off of the erase unit.

3. The image forming apparatus according to claim 2 , wherein the state acquisition unit is configured to acquire a current difference between the first current and the second current as the deterioration state of the charging member.

4. The image forming apparatus according to claim 2 , further comprising:
a change unit configured to change a voltage to be applied from the charging member to the image carrier during image formation, based on the deterioration state of the charging member.

5. The image forming apparatus according to claim 2 , further comprising:
a display configured to display a deterioration level of the charging member based on the deterioration state of the charging member.

6. The image forming apparatus according to claim 2 , wherein when a time after the forming unit forms the charged region and the erased region on the surface of the image carrier until an image forming operation is started is shorter than a predetermined time, the erase unit erases the charge from the surface of the image carrier.

7. The image forming apparatus according to claim 1 , wherein the state acquisition unit is configured to acquire a current difference between the first current and the second current as the deterioration state of the charging member.

8. The image forming apparatus according to claim 7 , further comprising:
a change unit configured to change a voltage to be applied from the charging member to the image carrier during image formation, based on the current difference.

9. The image forming apparatus according to claim 8 , wherein the change unit is configured to change the voltage such that the smaller the current difference is, the higher the voltage to be applied from the charging member to the image carrier during the image formation is.

10. The image forming apparatus according to claim 7 , further comprising:
a display configured to display a deterioration level of the charging member based on the current difference.

11. The image forming apparatus according to claim 10 , wherein as the current difference decreases, the display displays the deterioration level indicating that the charging member more deteriorates.

12. The image forming apparatus according to claim 7 , further comprising:
a display configured to display a warning when the current difference is smaller than a predetermined value.

13. The image forming apparatus according to claim 1 , further comprising:
a change unit configured to change a voltage to be applied from the charging member to the image carrier during image formation, based on the deterioration state of the charging member.

14. The image forming apparatus according to claim 1 , further comprising:
a display configured to display a deterioration level of the charging member based on the deterioration state of the charging member.

15. The image forming apparatus according to claim 1 , wherein when a time after the forming unit forms the charged region and the erased region on the surface of the image carrier until an image forming operation is started is shorter than a predetermined time, the erase unit erases the charge from the surface of the image carrier.

16. An image forming apparatus comprising:
an image carrier configured to carry an image to be transferred onto a recording medium;
a charging member in contact with the image carrier, the charging member configured to charge the image carrier;
an erase unit configured to erase charge on the image carrier;
a current detector configured to detect a current that flows to the charging member;
a forming unit configured to
form a charged region on a surface of the image carrier, and
form an erased region on the surface of the image carrier using the erase unit; and

a change unit configured to change a voltage applied from the charging member to the image carrier during image formation based on (i) a first current that flows in response to applying a voltage from the charging member to the erased region and (ii) a second current that flows in response to applying a voltage from the charging member to the charged region.

17. An image forming apparatus comprising:
image carrying means for carrying an image to be transferred onto a recording medium;
charging means in contact with the image carrying means, the charging means for charging the image carrier;
erase means for erasing charge on the image carrying means;
current detecting means for detecting a current that flows to the charging means;
forming means for
forming a charged region on a surface of the image carrying means, and
forming an erased region on the surface of the image carrying means using the erase means; and

state acquisition means for acquiring a deterioration state of the charging means based on (i) a first current that flows in response to applying a voltage from the charging means to the erased region and (ii) a second current that flows in response to applying a voltage from the charging means to the charged region.

Assignees

• Fuji Xerox Co Ltd

Inventors

• Shintaku Kanji
• Ando Hiroki
• Iida Hirofumi
• Araki Keishi
• Mizoguchi Satoshi
• Oka Hiroki

Classifications

• G03G2215/0463

  Exposure lamp used for scanning · CPC title

• G03G15/0266 Primary

  Arrangements for controlling the amount of charge · CPC title

• G03G15/0275

  Arrangements for controlling the area of the photoconductor to be charged · CPC title

• G03G2215/025

  using contact charging means having lateral dimensions related to other apparatus means, e.g. photodrum, developing roller · CPC title

• G03G15/5016

  User-machine interface; Display panels; Control console · CPC title