IP Library › Granted Patent US 7,539,429
Granted Patent B2
US 7,539,429 · App. 11/438,352 · Granted May 26, 2009

Image forming apparatus having a stable image density

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Quick Facts
Patent No.
US 7,539,429
App. No.
11/438,352
Granted
May 26, 2009
Kind
B2
Abstract

An image forming apparatus is provided capable of preventing fog from happening and obtaining more stable image density, which includes an image carrier; a charging section for charging surface of the image carrier; an exposing section for forming an electrostatic latent image on the image carrier; a developing section for making developer adhere to the electrostatic latent image formed on the image carrier so as to form a visible image; a transferring section to transfer the visible image onto a transfer member; a density detecting section to detect a density of the visible image; a development voltage setting section to set a development; a charge voltage setting section to set a difference between the charge voltage and the development into a value in a predetermined range; and an exposure quantity setting section to set an appointed exposure quantity with respect to the charge voltage.

Claims (61)

1. An image forming apparatus, comprising:

an image carrier;

a charging section which is provided with a charge voltage and charges surface of said image carrier;

an exposing section for forming an electrostatic latent image on the surface of said image carrier;

a developing section which is provided with a development voltage and makes developer adhere to said electrostatic latent image formed on said image carrier so as to form a visible image;

a transferring section to transfer said visible image onto a transfer member;

a density detecting section to detect a density of said visible image on said transfer member;

a development voltage setting section to set a development voltage to be provided to said developing section based on said density detected by said density detecting section;

a charge voltage setting section to set a difference between said charge voltage provided to said charging section and said development voltage set by said development voltage setting section into a value in a predetermined range; and

an exposure quantity setting section to set an appointed exposure quantity with respect to said charge voltage.

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

an environment information detecting section to detect environment information in the image forming apparatus; and

an environment table to memorize voltage according to said detected environment information,

wherein according to said detected environment information, a difference between said charge voltage provided to said charging section and said development voltage set by said development voltage setting section is set into a value in predetermined range.

3. The image forming apparatus according to claim 2 ,

wherein said environment information is either of temperature and humidity in the image forming apparatus.

4. The image forming apparatus according to claim 3 , further comprising:

a print information detecting section to detect print information; and

a temporality setting table to memorize voltage according to said detected print information,

wherein according to said detected print information, a difference between said charge voltage provided to said charging section and said development voltage set by said development voltage setting section is set into a value in predetermined range.

5. The image forming apparatus according to claim 4 ,

wherein said print information is the number of print sheets.

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

a print information detecting section to detect print information; and

a temporality setting table to memorize voltage according to said detected print information,

wherein according to said detected print information, a difference between said charge voltage provided to said charging section and said development voltage set by said development voltage setting section is set into a value in predetermined range.

7. The image forming apparatus according to claim 6 ,

wherein said print information is the number of print sheets.

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

a print information detecting section to detect print information; and

a temporality setting table to memorize voltage according to said detected print information,

wherein according to said detected print information, a difference between said charge voltage provided to said charging section and said development voltage set by said development voltage setting section is set into a value in predetermined range.

9. The image forming apparatus according to claim 8 ,

wherein said print information is the number of print sheets.

10. An image forming apparatus, comprising:

an image carrier;

a charging section which is provided with a charge voltage and charges surface of said image carrier;

a exposing section for forming an electrostatic latent image on the surface of said image carrier;

a developing section which is provided with a development voltage and makes developer adhere to said electrostatic latent image formed on said image carrier so as to form a visible image;

a transferring section to transfer said visible image onto a transfer member;

a density detecting section to detect a density of said visible image on said transfer member;

a development voltage setting section to set a development voltage to be provided to said developing section based on said density detected by said density detecting section;

a potential detecting section to detect surface voltage of said visible image;

a charge voltage setting section to set a difference between said charge voltage provided to said charging section and said development voltage set by said development voltage setting section into a value in a predetermined range on the basis of said surface voltage detected by said potential detecting section; and

an exposure quantity setting section to set an appointed exposure quantity with respect to said charge voltage.

11. The image forming apparatus according to claim 10 ,

wherein said potential detecting section is to detect a visible image potential on said image carrier.

12. The image forming apparatus according to claim 11 ,

wherein said potential detecting section is a potential sensor.

13. The image forming apparatus according to claim 10 ,

wherein said potential detecting section is to detect a visible image potential on said transfer member.

14. The image forming apparatus according to claim 13 ,

wherein said potential detecting section is a potential sensor.

15. The image forming apparatus according to claim 10 ,

wherein said potential detecting section is to detect a visible image potential on said developing section.

16. The image forming apparatus according to claim 15 ,

wherein said potential detecting section is a potential sensor.

17. The image forming apparatus according to claim 15 ,

wherein said potential detecting section is a development electric current detecting circuit.

18. The image forming apparatus according to claim 10 ,

wherein said potential detecting section is a potential sensor.

Assignments (1)
MERGER Recorded Mar 14, 2022
From: OKI DATA CORPORATION
To: OKI ELECTRIC INDUSTRY CO., LTD.
Reel/Frame 059365/0145 →