Image forming method and image forming apparatus for forming an image by setting various pixels of an exposure pattern as a non-exposure pixel group or a high-output exposure pixel group

Patent metadata

Field	Value
Publication number	US-9933722-B2
Application number	US-201615193480-A
Country	US
Kind code	B2
Filing date	Jun 27, 2016
Priority date	Jun 29, 2015
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

An image forming method is for forming an image using an electrostatic latent image that is formed by exposing a surface of an image bearer in accordance with an image pattern that includes a plurality of image areas in combination. Each of the plurality of image areas includes a plurality of pixels. A part of pixels to be exposed in each of the plurality of image areas is set as a non-exposure pixel group in accordance with a position of any one of the plurality of image areas in the image pattern. Pixels that are different from the non-exposure pixel group in each of the plurality of image areas are set as a high-output exposure pixel group that is exposed with an optical output value that is higher than a predetermined optical output value that is needed to expose the image area.

First claim

What is claimed is:

1. An image forming method, comprising:
identifying a position of a reference area and a position of an image area on a surface of a recording medium for forming thereon an image pattern of an image;
setting a first part of pixels of an exposure pattern that corresponds to a first portion of the image area outside the reference area as a non-exposure pixel group;
setting a second part of the pixels of the exposure pattern that corresponds to a second portion of the image area on an edge of the image area as a high-output exposure pixel group, the first portion and the second portion of the image area being on opposite sides of the image area;
exposing a surface of an image bearer to form an electrostatic latent image on the surface of the image bearer, including exposing a third part of the pixels different from the non-exposure pixel group and the high-output exposure pixel group according to a predetermined optical output value, and exposing the high-output exposure pixel group according to an optical output value that is higher than the predetermined optical output value; and
forming the image on the recording medium based on the electrostatic latent image.

2. The image forming method according to claim 1 , wherein
the position of the reference area is specified in accordance with an average position of the image area and one or more other image areas on the surface of the recording medium for forming thereon one or more other image patterns of the image, and
the image pattern and the one or more other image patterns correspond to a same portion of the image for different color plates.

3. The image forming method according to claim 1 , wherein a width of the first, portion of the image area along a particular scanning direction and a width of the second portion of the image area along the particular scanning direction are the same.

4. The image forming method according to claim 1 , wherein the optical output value for exposing the high-output exposure pixel group is set to 200% of the predetermined optical output value.

5. An image forming method, comprising:
identifying a first position of a first image area on a surface of a recording medium for forming thereon a first image pattern of an image;
identifying a second position of a second image area on the surface of the recording medium for forming thereon a second image pattern of the image, the first image pattern and the second image pattern corresponding to a same portion of the image;
setting a first part of pixels of a first exposure pattern that corresponds to a first portion of the first image area as a first non-exposure pixel group in accordance with the first position and a middle position between the first and second positions;
setting a second part of the pixels of the first exposure pattern that corresponds to a second portion of the first image area on an edge of the first image area as a first high-output exposure pixel group in accordance with a width of the first portion of the first image area, the first portion and the second portion of the first image area being on opposite sides of the first image area;
exposing a surface of an image bearer to form a first electrostatic latent image on the surface of the image bearer, including exposing a third part of the pixels of the first exposure pattern different from the first non-exposure pixel group and the first high-output exposure pixel group according to a predetermined optical output value, and exposing the first high-output exposure pixel group according to an optical output value that is higher than the predetermined optical output value; and
forming the image on the recording medium based on the first electrostatic latent image.

6. The image forming method according to claim 5 , further comprising:
setting a fourth part of pixels of a second exposure pattern that corresponds to a third portion of the second image area as a second non-exposure pixel group in accordance with the second position and the middle position between the first and second positions;
setting a fifth part of the pixels of the second exposure pattern that corresponds to a fourth portion of the second image area on an edge of the second image area as a second high-output exposure pixel group in accordance with a width of the third portion of the second image area, the third portion and the fourth portion of the second image area being on opposite sides of the second image area; and
exposing the surface of the image bearer to form a second electrostatic latent image on the surface of the image bearer, including exposing a sixth part of the pixels of the second exposure pattern different from the second non-exposure pixel group and the second high-output exposure pixel group according to the predetermined optical output value, and exposing the second high-output exposure pixel group according to the optical output value that is higher than the predetermined optical output value,
wherein the forming the image on the recording medium is further based on the second electrostatic latent image.

7. The image forming method according to claim 5 , wherein the optical output value for exposing the high-output exposure pixel group is set to 200% of the predetermined optical output value.

8. The image forming method according to claim 5 , wherein the first image pattern and the second image pattern corresponds to the same portion of the image for different color plates.

9. An image forming apparatus, comprising:
circuitry configured to:
identify a position of a reference area and a position of an image area on a surface of a recording medium for forming thereon an image pattern of an image;
set a first part of pixels of an exposure pattern that corresponds to a first portion of the image area outside the reference area as a non-exposure pixel group; and
set a second part of the pixels of the exposure pattern that corresponds to a second portion of the image area on an edge of the image area as a high-output exposure pixel group, the first portion and the second portion of the image area being on opposite sides of the image area;

an image bearer configured to form the image on the recording medium based on an electrostatic latent image formed on the image bearer; and
an exposure device coupled with the circuitry and configured to expose a surface of the image bearer to form the electrostatic latent image by exposing a third part of the pixels different from the non-exposure pixel group and the high-output exposure pixel group according to a predetermined optical output value, and exposing the high-output exposure pixel group according to an optical output value that is higher than the predetermined optical output value.

10. The image forming apparatus according to claim 9 , wherein
the circuitry is configured to specify the position of the reference in accordance with an average position of the image area and one or more other image areas on the surface of the recording medium for forming thereon one or more other image patterns of the image, and
the image pattern and the one or more other image patterns correspond to a same portion of the image for different color plates.

11. The image forming apparatus according to claim 9 , wherein the circuitry is configured to set the second part of the pixels of the exposure pattern that corresponds to the second portion of the image area as the high-output exposure pixel group in a manner that a width of the first portion of the image area along a particular scanning direction and a width of the second portion of the image area along the particular scanning direction are the same.

12. The image forming apparatus ac

Assignees

• Tachibana Hiroto
• Suhara Hiroyuki
• Ueno Yuichi
• Ricoh Co Ltd

Inventors

• Tachibana Hiroto
• Suhara Hiroyuki
• Ueno Yuichi

Classifications

• G03G15/043 Primary

  with means for controlling illumination or exposure (G03G15/041 takes precedence) · CPC title