IMAGE FORMING APPARATUS CAPABLE OF SETTING A PARAMETER USED IN FORMING AN IMAGE BASED ON A DETECTED CHANGE IN A VALUE OF TINT

• US 20170371262A1
• Filed: 06/21/2017
• Published: 12/28/2017
• Est. Priority Date: 06/27/2016
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Uchiyama, Akihiko
• Granted Patent: US 10,168,634 B2
• Time in Patent Office: Days
• CPC Class Codes: G03G 15/0178 using more than one reusable electrographic recording member, e.g. one for every monocolour image
• CPC Class Codes: G03G 15/0189 primary transfer to an intermediate transfer belt G03G15/0184 takes precedence
• CPC Class Codes: G03G 15/5008 Driving control for rotary photosensitive medium, e.g. speed control, stop position control
• CPC Class Codes: G03G 15/5041 Detecting a toner image, e.g. density, toner coverage, using a test patch G03G15/553 takes precedence
• CPC Class Codes: G03G 15/5058 using a test patch

Abstract

An image forming apparatus includes a CPU configured to change a parameter value used to control a developer bearing amount and form a plurality of patches for different parameter values changed, and a color sensor configured to measure the plurality of patches thereby acquiring color information thereof. The CPU detects, from values of color information of the plurality of patches, a value of the color information at which a change greater than or equal to a predetermined threshold value occurs, and the CPU sets a parameter used in forming an image based on the detected value of color information.

Claims

1. An image forming apparatus comprising:

a plurality of forming units respectively corresponding to a plurality of colors, each forming unit including a photosensitive member on which a latent image is formed and a developing unit configured to develop, using a developer, the latent image formed on the photosensitive member thereby forming a developer image;

a control unit configured to change a parameter used to control a developer bearing amount and control the forming units to form a plurality of detection images according to different parameters; and

a color measurement unit configured to measure a plurality of values of tint according to the plurality of detection images formed by the forming units,

the control unit being configured to specify a value, among the plurality of values of tint, showing a change in tint greater than or equal to a predetermined amount, and set a parameter for use in forming the image depending on the value showing the change in tint greater than or equal to the predetermined amount.

2. The image forming apparatus according to claim 1, wherein the control unit is configured to specify a specific detection image corresponding to the value of tint showing the change in tint greater than or equal to the predetermined amount, and setting a parameter used in forming the specific detection image as a parameter for use in forming the image.

3. The image forming apparatus according to claim 1, wherein

the plurality of developing units are driven independently of each other, and

the parameter is a peripheral speed of each developing unit.

4. The image forming apparatus according to claim 3, the control unit is configured such that in a case where the plurality of detection images are formed for different peripheral speeds of the developing unit, fixed image data is used in forming the plurality of detection images.

5. The image forming apparatus according to claim 3, wherein the control unit is configured such that in a case where the plurality of detection images are formed for different peripheral speeds of the developing unit, as for detection images of a same color for different peripheral speeds of the developing unit, forming of the detection images is performed at predetermined time intervals.

6. The image forming apparatus according to claim 5, wherein the control unit is configured such that in a case where at any of the plurality of values of tint, a change in tint greater than or equal to the predetermined amount does not occur, a peripheral speed smaller than the greatest peripheral speed of the developing unit used in forming the plurality of detection images is set as the peripheral speed of the developing unit used in forming the image.

7. The image forming apparatus according to claim 1, wherein the parameter is image data.

8. The image forming apparatus according to claim 7, wherein the control unit is configured such that in a case where the plurality of detection images are formed for different image data, as for detection images of a same color for different image data, forming of the detection images is performed at predetermined time intervals.

9. The image forming apparatus according to claim 7, wherein the control unit is configured such that in a case where the plurality of detection images are formed for different image data, detection images of a same color for different image data are formed in a sequential order.

10. The image forming apparatus according to claim 9, wherein

the image data is bit data, and

the control unit is configured such that in a case where at any of the plurality of values of tint, a change in tint greater than or equal to the predetermined amount does not occur, a value smaller than or equal to a maximum value capable of being represented by the bit data is set as image data used in forming the image.

11. The image forming apparatus according to claim 1, further comprising a voltage applying unit configured to apply a voltage to the developing unit,

wherein the parameter is the voltage applied to the developing unit from the voltage applying unit.

12. The image forming apparatus according to claim 11, wherein the control unit is configured such that in a case where the plurality of detection images are formed for different voltages applied to the developing unit from the voltage applying unit, the different voltages changed by amounts from a predetermined initial voltage, image data of the plurality of detection images is fixed.

13. The image forming apparatus according to claim 11, wherein the control unit is configured such that in a case where the plurality of detection images are formed for different voltages applied to the developing unit from the voltage applying unit, the different voltages changed by amounts from a predetermined initial voltage, as for detection images of a same color for different voltages applied to the developing unit, forming of the detection images is performed at predetermined time intervals.

14. The image forming apparatus according to claim 13, wherein the control unit is configured such that in a case where at any of the plurality of values of tint, a change in tint greater than or equal to the predetermined amount occurs, a voltage within the range in which the voltage is changed is set as the development voltage used in forming the image.

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

a charging unit configured to charge the photosensitive member, and

an exposure unit configured to form a latent image on the photosensitive member charged by the charging unit,

wherein the parameters are the potential of the photosensitive member charged by the charging unit and a latent image contrast value determined by an amount of exposure light provided by the exposure unit.

16. The image forming apparatus according to claim 1, wherein

the developer is a two-component developer including toner and a carrier, and

the parameter is a mixing ratio between the toner and the carrier.

17. The image forming apparatus according to claim 1, wherein the control unit is configured to determine a hue angle for each of the plurality of detection images based on a result of color measurement performed by the color measurement unit, and detect, from the plurality of detection images, a detection image at which a change in the hue angle occurs.

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

a transfer unit configured to transfer a toner image formed on the photosensitive member to a recording material, and

a fixing unit configured to fix the detection image transferred to the recording material by the transfer unit,

wherein the color measurement unit is configured to measure the detection image on the recording material fixed by the fixing unit.

19. The image forming apparatus according to claim 18, further comprising a duplex conveying path configured such that a recording material having an image formed on a first side of the recording material is conveyed along the duplex conveying path to form an image on a second side of the recording material,

wherein the color measurement unit is disposed in the duplex conveying path.

20. The image forming apparatus according to claim 1, further comprising a detection unit configured to detect a density of a developer image,

wherein the control unit is configured to correct a tone of an image based on a result of detection performed by the detection unit in terms of a density of a developer image formed using a parameter used in forming a particular detection image.