Image Forming Apparatus and Image Forming Method

• US 20120127488A1
• Filed: 11/09/2011
• Published: 05/24/2012
• Est. Priority Date: 11/19/2010
• Status: Abandoned Application

• Current Assignee: KYOCERA Document Solutions, Inc. (Kyocera Corporation)
• Original Assignee: Kyocera MITA Corporation (Kyocera Corporation)
• Inventors: Nakatsuji, Hiroomi
• Application Number:
  US13/292,592
• Publication Number:
  US 20120127488A1
• Time in Patent Office: Days
• US Class Current: 358/1.1
• CPC Class Codes: G03G 15/5025 by measuring the original characteristics, e.g. contrast, density
• CPC Class Codes: G03G 15/556 for toner consumption, e.g. pixel counting, toner coverage detection or toner density measurement

Abstract

An image forming apparatus has: (a) a character-area identifying unit that identifies a character area in image data, and (b) a screen processing unit that performs a screen process of an area in the image data other than the character area by using a first dot growth pattern, and performs a screen process of the character area by using a second dot growth pattern different from the first dot growth pattern.

Claims

1. An image forming apparatus, comprising:

a character-area identifying unit that identifies a character area in image data; and

a screen processing unit that performs a screen process of an area in the image data other than the character area by using a first dot growth pattern, and performs a screen process of the character area by using a second dot growth pattern different from the first dot growth pattern.

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

the screen processing unit applies dot growth along the second dot growth pattern by changing both the number of dots and dot intensity according to a pixel value in the image data.

3. The image forming apparatus according to claim 2, wherein:

the screen processing unit sets the dot intensity corresponding to a pixel value in the character area lower than the dot intensity corresponding to the same pixel value in the area other than the character area.

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

a photoconductor;

an exposure device that scans a beam on the photoconductor to form an electrostatic latent image for toner development; and

a controller that controls light exposure of the beam from the exposure device to the photoconductor;

wherein the controller sets an exposure period of the beam, and the screen processing unit changes the dot intensity by changing the exposure period on a pixel in the character area according to a pixel value of the pixel.

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

a photoconductor;

an exposure device that scans a beam on the photoconductor to form an electrostatic latent image for toner development; and

a controller that controls light exposure of the beam from the exposure device to the photoconductor;

wherein the controller sets an exposure period of the beam, and the screen processing unit changes the dot intensity by changing the exposure period on a pixel in the character area according to a pixel value of the pixel.

6. The image forming apparatus according to claim 4, wherein:

the length of the exposure period for a pixel in the character area is set shorter than a scanning period for the pixel, and the exposure period is set in the center of the scanning period.

7. The image forming apparatus according to claim 5, wherein:

the length of the exposure period for a pixel in the character area is set shorter than a scanning period for the pixel, and the exposure period is set in the center of the scanning period.

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

the screen processing unit performs both screen processes for the character area and for the area other than the character area with a same screen ruling.

9. The image forming apparatus according to claim 1, wherein:

the screen processing unit performs a screen process for the character area with a screen ruling higher than a screen ruling of the area other than the character area.

10. The image forming apparatus according to claim 1, wherein:

the screen processing unit performs both screen processes with the first dot growth pattern and with the second growth pattern with a same screen angle.

11. An image forming method, comprising the steps of:

(a) identifying a character area in image data; and

(b) performing a screen process of an area in the image data other than the character area by using a first dot growth pattern, and a screen process of the character area by using a second dot growth pattern different from the first dot growth pattern.