Image forming method, image forming apparatus, and printer mater

Abstract

In relation to a superimposed image obtained by superimposing second image data on first image data in which respective pixels are arranged in a staggered pattern, an image forming apparatus discriminates a region where the second image data is superimposed from a region where the second image data is not superimposed. When forming an image in a region determined as the region where the second image data is not superimposed in the superimposed image, the printing mechanism is controlled based on a first control pattern. When forming an image in a region determined as the region where the second image data is superimposed in the superimposed image, the printing mechanism is controlled based on a second control pattern different from the first control pattern.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

FIG. 1 is a block diagram schematically showing a structure of an image processing apparatus to which a first to a fourth image processing methods according to the present invention are applied;

FIG. 2 is a view showing an arrangement example of dots when heat generators in a thermal head are alternately driven;

FIG. 3A is a view showing a temperature distribution when all heat generators are driven;

FIG. 3B is a view showing a temperature distribution when adjacent heat generators are alternately driven;

FIG. 4 is a view showing an example of an arrangement of pixels in image data;

FIG. 5 is a view showing an example of image data obtained by converting respective pixels in the image data depicted in FIG. 4 into an arrangement having a staggered pattern;

FIG. 6 is a flowchart for explaining a flow of processing by a first image processing method;

FIG. 7A is a view showing an example of first image data;

FIG. 7B is a view showing an example where respective pixels in the image data depicted in FIG. 7A are rearranged into a staggered pattern;

FIG. 8A is a view showing a binary image as second image data superimposed on the first image data;

FIG. 8B is a view showing an example of image data obtained by superimposing such a binary image as depicted in FIG. 8A on the first image data in which respective pixels are arranged in a staggered pattern;

FIG. 8C is a view showing an example of a peripheral region of a pixel on which a pixel of the second image data is superimposed in the image data depicted in FIG. 8B;

FIG. 8D is a view showing an example of a peripheral region of a pixel on which a pixel of the second image data is not superimposed in the image data depicted in FIG. 8B;

FIG. 9 is a view showing an example of a printed matter created by the first image processing method;

FIG. 10A is a view showing an example of a fluorescent image having a region where all pixels are printed (an all-pixel aligned part) and a region where pixels arranged in a staggered pattern are printed (an alternate pixel aligned part);

FIG. 10B is a view showing a multi-gradation image superimposed and printed on a fluorescent image;

FIG. 10C is a view showing an example of a binary image superimposed and printed on a fluorescent image;

FIG. 11 is a view showing a state where a multi-gradation image and a binary image are superimposed and printed on a fluorescent image;

FIG. 12 is a flowchart for explaining a flow of processing by a second image processing method;

FIG. 13 is a view showing an example of a printed matter created by the second image processing method;

FIG. 14A is a view showing a temperature distribution of heat generators in a thermal head;

FIG. 14B is a view showing an example of application pulses to heat generators that provide such a temperature distribution as shown in FIG. 14A;

FIG. 15 is a view showing a state of an arrangement of pixels in image data where all pixels are effective;

FIG. 16 is a view showing a state of an arrangement of pixels in image data where adjacent pixels are thinned out;

FIG. 17 is a flowchart for explaining a flow of processing by a third image processing method; and

FIG. 18 is a flowchart for explaining a flow of processing by a fourth image processing method.

Claims

1. An image forming method of forming an image on a recording medium by using a printing mechanism, comprising: discriminating a region where second image data is superimposed from a region where the second image data is not superimposed in relation to a superimposed image obtained by superimposing the second image data on first image data in which respective pixels are arranged in a staggered pattern;controlling the printing mechanism based on a first control pattern when forming an image in a region determined as the region where the second image data is not superimposed in the superimposed image; andcontrolling the printing mechanism based on a second control pattern different form the first control pattern when forming an image in a region determined as the region where the second image data is superimposed in the superimposed image.

2. The image forming method according to claim 1, further comprising: inputting the first image data;converting respective pixels in the input first image data into an arrangement having a staggered pattern; andproducing a superimposed image in which the second image data is superimposed on the first image data in which the respective pixels are converted into the arrangement having the staggered pattern.

3. The image forming method according to claim 1, wherein the first data is a multi-gradation image, and the second image data is a binary image.

4. The image forming method according to claim 1, wherein the printing mechanism sequentially forms in a sub-scanning direction a plurality of pixels along a main scanning direction,controlling the printing mechanism in accordance with a continuous line number counted every two lines when forming an image in the region where the second image data is not superimposed based on control with the first control pattern; andcontrolling the printing mechanism in accordance with a continuous line number counted every line when forming an image in the region where the second image data is superimposed by using the printing mechanism controlled based on the second control pattern.

5. The image forming method according to claim 4, wherein the printing mechanism is constituted of a plurality of heat generators aligned in the main scanning direction, andthe control in accordance with the continuous line number is control of controlling heat stored in each heat generator.

6. An image forming method of forming an image on a recording medium by using a printing mechanism, comprising: discriminating a region where an image is formed in a specific region on a recording medium from a region where an image is formed in a region other than the specific region;controlling the printing mechanism based on a first control pattern when forming an image in the region other than the specific region; andcontrolling the printing mechanism based on a second control pattern different from the first control pattern when forming an image in the specific region.

7. The image forming method according to claim 6, wherein the printing mechanism is constituted of a plurality of heat generators, andthe first and the second control patterns are patterns of controlling energies supplied to the heat generators, respectively.

8. The image forming method according to claim 6, wherein the specific region on the recording medium is a region where a background image is formed.

9. The image forming method according to claim 6, wherein the background image is a fluorescent image.

10. The image forming method according to claim 8, wherein the background image has a first region where all pixels are printed and a second region where pixels are thinned out and printed, andthe method further comprising:discriminating a region where an image is formed in the first region of the background image, a region where an image is formed in the second region of the background image, and a region where an image is formed in a region other than the background image from each other;controlling the printing mechanism based on a third control pattern when superimposing and printing an image in the first region of the background image; andcontrolling the printing mechanism based on a fourth control pattern different from the third control pattern when superimposing and printing an image in the second region of the background image.

11. The image forming method according to claim 6, wherein the printing mechanism sequentially prints in a sub-scanning direction a plurality of pixels along a main scanning direction, andthe method further comprises controlling the printing mechanism in accordance with a continuous line number counted every line.

12. The image forming method according to claim 11, wherein the printing mechanism is constituted of a plurality of heat generators aligned in the main scanning direction, andthe control in accordance with the continuous line number is control of controlling heat stored in each heat generator.

13. An image forming apparatus that forms an image on a recording medium by using a printing mechanism, comprising: a discriminating section that discriminates a region where second image data is superimposed from a region where the second image data is not superimposed in relation to a superimposed image obtained by superimposing the second image data on first image data in which respective pixels are arranged in a staggered pattern;a first control section that controls the printing mechanism based on a first control pattern when forming an image in a region determined as the region where the second image data is not superimposed in the superimposed image; anda second control section that controls the printing mechanism based on a second control pattern different from the first control pattern when forming an image in a region determined as the region where the second image data is superimposed in the superimposed image.

14. The image forming apparatus according to claim 13, further comprising: an input section that receives the first image data; anda superimposing section that converts the respective pixels in the first image data input by the input section into an arrangement having a staggered pattern, and generates a superimposed image in which the second image data is superimposed on the first image data in which the respective pixels are converted into the arrangement having the staggered pattern.

15. The image forming apparatus according to claim 13, wherein the printing mechanism sequentially prints in a sub-scanning direction a plurality of pixels along a main scanning direction,the first control section further controls the printing mechanism in accordance with a continuous line number counted every two lines when forming an image in the region where the second image data is not superimposed by using the printing mechanism that is controlled based on the first control pattern, andthe second control section further controls the printing mechanism in accordance with a continuous line number counted every line when forming an image in the region where the second image data is superimposed by using the printing mechanism that is controlled based on the second control pattern.

16. The image forming apparatus according to claim 15, wherein the printing mechanism is constituted of a plurality of heat generators aligned in the main scanning direction, andthe control in accordance with the continuous line number in each of the first control section and the second control section is control of controlling heat stored in each heat generator.

17. An image forming apparatus that forms an image on a recording medium by using a printing mechanism, comprising: a discriminating section that discriminates a region where an image is formed in a specific region on the recording medium from a region where an image is formed in a region other than the specific region;a first control section that controls the printing mechanism based on a first control pattern when forming an image in the region other than the specific region; anda second control section that controls the printing mechanism based on a second control pattern different form the first control pattern when forming an image in the specific region.

18. The image forming apparatus according to claim 17, wherein the specific region on the recording medium is a region where a background image is formed,the background image has a first region where all pixels are printed and a second region where pixels are thinned out and printed,the discriminating section discriminate a region where an image is formed in the first region of the background image, a region where an image is formed in the second region of the background image, and a region where an image is formed in a region other than the background image from each other, andthe second control section controls the printing mechanism based on a third control pattern when superimposing and printing an image in the first region of the background image, and controls the printing mechanism based on a fourth control pattern different from the third control pattern when superimposing and printing an image in the second region of the background image.

19. The image forming apparatus according to claim 17, wherein the printing mechanism sequentially prints in a sub-scanning direction a plurality of pixels along a main scanning direction, andeach of the first control section and the second control section controls the printing mechanism in accordance with a continuous line number counted every line.

20. The image forming apparatus according to claim 19, wherein the printing mechanism is constituted of a plurality of heat generators aligned in the main scanning direction, andthe control by each of the first control section and the second control section in accordance with the continuous line number is control of controlling heat stored in each heat generator.

21. A printed matter on which an image is formed by a printing mechanism, comprising: a region where second image data is not superimposed printed by the printing mechanism controlled based on a first control pattern in a superimposed image obtained by superimposing the second image data on first image data in which respective pixels are arranged in a staggered pattern; anda region where the second image data is superimposed printed based on a second control pattern different from the first control pattern in the superimposed image.

22. The printed matter on which an image is formed by a printing mechanism, comprising: a region other than a specific region where an image is printed by the printing mechanism controlled based on a first control pattern; andthe specific region where an image is printed by the printing mechanism controlled based on a second control pattern different from the first control pattern.

23. The printed matter according to claim 22, wherein the specific region on the recording medium is a region where a background image is formed, andthe region of the background image has a first region where all pixels are printed and a second region where pixels are thinned out and printed, an image is superimposed and printed in the first region of the background image by the printing mechanism controlled based on a thirds control pattern, and an image is superimposed and printed in the second region of the background image by the printing mechanism controlled based on a fourth control pattern different from the third control pattern.