IMAGE FORMING APPARATUS

• US 20140064751A1
• Filed: 08/29/2013
• Published: 03/06/2014
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: Canon Finetech Nisca Incorporated (Canon Inc.)
• Original Assignee: Canon Finetech Incorporated (Canon Inc.)
• Inventors: KUROIWA, IKUYO
• Granted Patent: US 10,036,988 B2
• Time in Patent Office: Days
• US Class Current: 399/31
• CPC Class Codes: G03G 15/0208 by contact, friction or induction, e.g. liquid charging apparatus
• CPC Class Codes: G03G 15/55 Self-diagnostics; Malfunction or lifetime display
• CPC Class Codes: G03G 15/553 Monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of insufficient copy sheet quantity for a job

Abstract

Provided is an image forming apparatus capable of accurately detecting deformation of a roller member. The image forming apparatus configured to form an image by forming an electrostatic latent image on a photosensitive drum (1) and developing the electrostatic latent image by a developer, includes: a rotatable roller member (2) configured to be held in press-contact with the photosensitive drum (1); and a deformation determining unit configured to determine deformation of the roller member (2), and the deformation determining unit configured to detect a value of a current flowing between the roller member (2) and the photosensitive drum (1) in response to application of a voltage to the rotating roller member (2), and determine the deformation of the roller member (2) based on the detection result.

Claims

1. An image forming apparatus configured to form an image by forming an electrostatic latent image on an image bearing member and developing the electrostatic latent image by a developer, the image forming apparatus comprising:

a rotatable roller member configured to be held in press-contact with the image bearing member; and

a deformation determining unit configured to determine deformation of the roller member, and the deformation determining unit configured to determine the deformation of the roller member based on a value of a current flowing between the roller member and the image bearing member in response to application of a voltage to the rotating roller member.

2. An image forming apparatus according to claim 1, wherein the deformation determining unit determines whether the value of the current falls within a predetermined range, and

wherein the predetermined range has a plurality of ranges set in accordance with a level of the deformation of the roller member.

3. An image forming apparatus according to claim 1, wherein a rotating speed of the roller member when the deformation determining unit determines the deformation of the roller member is slower than a rotating speed of the roller member during image formation.

4. An image forming apparatus according to claim 1, wherein a voltage to be applied to the roller member by the deformation determining unit is smaller than a voltage to be applied to the roller member during image formation.

15. An image forming apparatus according to claim 1, wherein the roller member is any one of a charging roller configured to charge the image bearing member, a transfer roller configured to transfer a toner image formed on the image bearing member onto a sheet, and a cleaning roller configured to clean a member to be cleaned.

5. An image forming apparatus configured to form an image by forming an electrostatic latent image on an image bearing member and developing the electrostatic latent image by a developer, the image forming apparatus comprising:

a rotatable roller member configured to be held in press-contact with the image bearing member; and

a deformation determining unit configured to determine deformation of the roller member, and the deformation determining unit configured to determine a deformation level of the roller member based on at least one of a time period in which the roller member is left in a rotation stop state, an environment in which the roller member is left in the rotation stop state, a number of sheets subjected to recording on each of which an image is formed by the image bearing member with use of the roller member, and a resistance value of the roller member.

6. An image forming apparatus configured to form an image by forming an electrostatic latent image on an image bearing member and developing the electrostatic latent image by a developer, the image forming apparatus comprising:

a rotatable roller member configured to be held in press-contact with the image bearing member; and

a restoring unit configured to restore deformation of the roller member, and the restoring unit configured to apply an AC voltage to the roller member when not forming the image.

7. An image forming apparatus according to claim 6, further comprising a deformation determining unit configured to determine the deformation of the roller member,

wherein, when a deformation amount of the roller member determined by the deformation determining unit is large, the restoring unit applies the AC voltage having a frequency higher than a frequency of the AC voltage to be applied when the deformation amount is small.

8. An image forming apparatus according to claim 6, further comprising a deformation determining unit configured to determine the deformation of the roller member,

wherein, when a deformation amount of the roller member determined by the deformation determining unit is large, the restoring unit applies the AC voltage having an amplitude lager than an amplitude of the AC voltage to be applied when the deformation amount is small.

9. An image forming apparatus according to claim 6, further comprising a deformation determining unit configured to determine the deformation of the roller member,

wherein the deformation determining unit is configured to apply a voltage to the rotating roller member, detect a value of a current flowing between the roller member and the image bearing member, and determine the deformation of the roller member based on a result of the detection.

10. An image forming apparatus according to claim 9, wherein the deformation determining unit detects the deformation of the roller member when the value of the current detected in a rotating period of the roller member falls within a predetermined range.

11. An image forming apparatus according to claim 10, wherein the predetermined range has a plurality of ranges set in accordance with a level of the deformation of the roller member.

12. An image forming apparatus according to claim 9, wherein a rotating speed of the roller member when the deformation determining unit determines the deformation of the roller member is slower than a rotating speed of the roller member during image formation.

13. An image forming apparatus according to claim 6, further comprising a deformation determining unit configured to determine a deformation level of the roller member,

wherein the deformation determining unit is configured to determine based on at least one of a time period in which the roller member is left in a rotation stop state, an environment in which the roller member is left in the rotation stop state, a number of sheets subjected to recording on each of which an image is formed by the image bearing member with use of the roller member, and a resistance value of the roller member.

14. An image forming apparatus configured to form an image by forming an electrostatic latent image on an image bearing member and developing the electrostatic latent image by a developer, the image forming apparatus comprising:

a rotatable roller member configured to be held in press-contact with the image bearing member; and

a restoring unit configured to restore deformation of the roller member, and the restoring unit configured to perform different restoring according to the deformation of the roller member.