Image forming apparatus

• US 20050046691A1
• Filed: 08/23/2004
• Published: 03/03/2005
• Est. Priority Date: 08/29/2003
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Katagiri, Shinji, Maebashi, Yoichiro
• Granted Patent: US 7,710,610 B2
• Time in Patent Office: Days
• US Class Current: 347/221
• CPC Class Codes: G03G 15/5058 using a test patch
• CPC Class Codes: G03G 21/04 Preventing copies being made of an original
• CPC Class Codes: G03G 2215/00029 Image density detection
• CPC Class Codes: G03G 2215/00063 Colour
• CPC Class Codes: G03G 2215/0177 Rotating set of developing units

Abstract

An image forming apparatus includes an image forming unit adapted to form images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is registered thereon and superimpose those images to form a color image, a controller configured to control the image forming unit so as to form a patch image of each color for density detection, and a detector configured to detect the density of each of the patch images. The controller controls the image forming unit so as to superimpose the predetermined pattern of the predetermined color upon the patch image of a predetermined color and not to superimpose the predetermined pattern of the predetermined color upon the patch images of the other colors.

Claims

1. An image forming apparatus comprising:

an image forming unit adapted to form images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is registered thereon and superimpose those images to form a color image;

a controller configured to control said image forming unit so as to form a patch image of each color for density detection; and

a detector configured to detect the density of each of said patch images;

wherein said controller controls said image forming unit so as to superimpose said predetermined pattern of said predetermined color upon the patch image of a predetermined color and not to superimpose said predetermined pattern of said predetermined color upon the patch images of the other colors.

2. An image forming apparatus according to claim 1, further comprising an adjusting unit for adjusting an image forming condition of said image forming unit for each color on the basis of a result of detection by said detector.

3. An image forming apparatus according to claim 2, wherein said adjusting unit adjusts a density correction table.

4. An image forming apparatus according to claim 1, wherein said pattern is a pattern representative of discriminating information of the image forming apparatus.

5. An image forming apparatus according to claim 1, wherein said plurality of colors include yellow, magenta, cyan and black, and said predetermined color is yellow.

6. An image forming apparatus including:

an image forming unit adapted to form images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is superimposed thereon and superimpose those images to form a color image;

a controller configured to control said image forming unit so as to form a patch image of each color for density detection; and

a detector configured to detect the density of each of said patch images;

wherein said controller controls said image forming portion so as to superimpose said predetermined pattern of said predetermined color upon said patch images.

7. An image forming apparatus according to claim 6, wherein said controller controls said image forming unit so as to superimpose said predetermined pattern of said predetermined color upon the patch image of each color, and said image forming apparatus further comprises an adjusting unit for adjusting an image forming condition of said predetermined color on the basis of a result of detection by said detector, and adjusting the image forming condition of the other colors on the basis of the result of detection by said detector and the density of said predetermined pattern.

8. An image forming apparatus according to claim 7, wherein said adjusting unit adjusts a density correction table.

9. An image forming apparatus according to claim 6, wherein said pattern is a pattern representative of discriminating information of the image forming apparatus.

10. An image forming apparatus according to claim 6, wherein said plurality of colors include yellow, magenta, cyan and black, and said predetermined color is yellow.

11. An image forming apparatus including:

an image forming unit adapted to form images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is superimposed thereon and superimpose those images one upon another to thereby form a color image;

a controller configured to control said image forming unit so as to form a patch image of each color for density detection; and

superimpose those images one upon another to thereby form a color image;

a controller configured to control said image forming unit so as to four a patch image of each color for density detection;

a detector configured to detect the density of each of said patch images; and

an adjusting unit for adjusting an image forming condition of said predetermined color on the basis of a result of detection by said detector and the density of said predetermined pattern.

12. An image forming apparatus according to claim 11, wherein said adjusting unit adjusts a density correction table.

13. An image forming apparatus according to claim 11, wherein said pattern is a pattern representative of discriminating information of the image forming apparatus.

14. An image forming apparatus according to claim 11, wherein said plurality of colors include yellow, magenta, cyan and black, and said predetermined color is yellow.

15. A controlling method for an image forming apparatus for forming images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is superimposed thereon and superimposing those images one upon another to thereby form a color image, including:

a step of controlling an image forming unit so as to form a patch image of each color for density detection; and

a step of detecting the density of each of said patch images;

wherein at said controlling step, said image forming unit is controlled so that said predetermined pattern of said predetermined color may be superimposed upon the patch image of said predetermined color and said predetermined pattern of said predetermined color may not be superimposed upon the patch images of the other colors.

16. A controlling method for an image forming apparatus for forming images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is superimposed thereon and superimposing those images one upon another to thereby form a color image, including:

a step of controlling an image forming unit so as to form a patch image of each color for density detection; and

a step of detecting the density of each of said patch images;

wherein at said controlling step, said image forming unit is controlled so that said predetermined pattern of said predetermined color may be superimposed upon said patch images.

17. A controlling method for an image forming apparatus for forming images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is superimposed thereon and superimposing those images one upon another to thereby form a color image, including:

a step of controlling an image forming portion so as to form a patch image of each color for density detection;

a step of detecting the density of each of said patch images; and

a step of adjusting an image forming condition of said predetermined color on the basis of a result of detection at said detecting step, and the density of said predetermined pattern.