Image forming apparatus and method for selecting an optimal image space frequency for an output image

• US 20020131061A1
• Filed: 03/13/2002
• Published: 09/19/2002
• Est. Priority Date: 03/16/2001
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Aoyagi, Masato, Takahashi, Hiroshi
• Granted Patent: US 7,315,402 B2
• Time in Patent Office: Days
• US Class Current: 358/1.2
• CPC Class Codes: H04N 1/2307 Circuits or arrangements for the control thereof, e.g. using a programmed control device, according to a measured quantity H04N1/27, H04N1/29 take precedence
• CPC Class Codes: H04N 1/2315 according to characteristics of the reproducing apparatus, e.g. capability
• CPC Class Codes: H04N 1/2323 according to characteristics of the reproducing medium, e.g. type, size or availability
• CPC Class Codes: H04N 1/2369 Selecting a particular reproducing mode from amongst a plurality of modes, e.g. paper saving or normal, or simplex or duplex
• CPC Class Codes: H04N 1/3935 with modification of image resolution, i.e. determining the values of picture elements at new relative positions
• CPC Class Codes: H04N 1/4055 producing a clustered dots or a size modulated halftone pattern

Abstract

An image forming apparatus includes an image forming device configured to form an output image using at least two or more image space frequencies and an image size acquisition device configured to recognize a size of the output image. A switching device is configured to select one of the at least two or more image frequencies for the output image according to the size of the output image recognized by the image size acquisition device and to switch the image forming device so as to form the output image using the one of two or more image frequencies.

Claims

1. An image forming apparatus, comprising:

an image forming device configured to form an output image by at least two or more image space frequencies;

an image size acquisition device configured to recognize a size of the output image; and

a switching device configured to select one of the at least two or more image frequencies for the output image according to the size of the output image recognized by the image size acquisition device and to switch the image forming device so as to form the output image by the one of the at least two or more image frequencies.

4. The image forming apparatus according to claim 1,

wherein the switching device is configured to select the one of the at least two or more image frequency for the output image and to switch the image forming device so as to form the output image using the one of the at least two or more image frequencies in a multi-step manner.

7. The image forming apparatus according to claim 1,

wherein the switching device selects the one of the at least two or more image frequencies for the output image by comparing the size of the output image recognized by the image size acquisition device with a predetermined criterion output image size.

8. The image forming apparatus according to claim 7,

wherein the predetermined criterion image size is based on a visual characteristic.

9. The image forming apparatus according to claim 1,

wherein the size of the output image recognized by the image size acquisition device includes a size of a side of the output image in a predetermined direction, and

wherein the switching device selects the one of at least two or more image space frequencies for the output image based on the size of a side of the output image in the predetermined direction.

10. The image forming apparatus according to claim 1,

wherein the size of the output image recognized by the image size acquisition device includes sizes of the output image in vertical and horizontal directions, and

wherein the switching device selects the one of at least two or more image space frequencies for the output image based on the sizes of the output image in vertical and horizontal directions.

11. The image forming apparatus according to claim 1,

wherein the switching device is configured to calculate area of the output image from the size of the output image recognized by the image size acquisition device and to select the one of at least two or more image space frequencies for the output image based on the area.

12. The image forming apparatus according to claim 1,

wherein the image size acquisition device is configured to recognize, when the output image includes a plurality of output images in a same page, respective sizes of the plurality of output images in the same page, and

wherein the switching device is configured to select, when the output image includes a plurality of output images in a same page, one of the at least two or more image space frequencies for the plurality of output images in the same page based on one of the respective sizes of the plurality of output images in the same page recognized by the image acquisition device, and to switch the image forming device so as to form each of the plurality of output images in the same page using the one of at least two or more image space frequencies.

13. The image forming apparatus according to claim 1,

wherein the image size acquisition device is configured to recognize, when the output image includes a plurality of output images in a same file, respective sizes of the plurality of output images in the same file, and

wherein the switching device is configured to select, when the output image includes a plurality of output images in a same file, one of the at least two or more image space frequencies for the plurality of output images in the same file based on one of the respective sizes of the plurality of output images in the same file recognized by the image acquisition device, and to switch the image forming device so as to form each of the plurality of output images in the same file using the one of at least two or more image space frequencies.

14. The image forming apparatus according to claim 1,

wherein the image forming device includes a plurality of dither patterns, each having a substantially same basic tone.

17. The image forming apparatus according to claim 14,

wherein the plurality of dither patterns have predetermined screen angles respectively that are substantially identical to each other.

18. The image forming apparatus according to claim 15,

wherein the plurality of dither patterns have predetermined screen angles respectively that are substantially identical to each other.

19. The image forming apparatus according to claim 16,

wherein the plurality of dither patterns have predetermined screen angles respectively that are substantially identical to each other.

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

a selecting method setting device configured to set at the switching device a selecting method for selecting the one of at least two or more image space frequencies for the output image.

2. An image forming apparatus, comprising:

an image forming device configured to form an output image by at least two or more image space frequencies;

an output size acquisition device configured to recognize a size of an output sheet for the output image; and

a switching device configured to select one of the at least two or more image space frequencies for the output image according to the size of the output sheet size for the output image recognized by the output size acquisition device and to switch the image forming device so as to form the output image using the one of the at least two or more image space frequencies.

5. The image forming apparatus according to claim 2,

wherein the switching device is configured to select the one of the at least two or more image frequency for the output image and to switch the image forming device so as to form the output image using the one of the at least two or more image frequencies in a multi-step manner.

15. The image forming apparatus according to claim 2,

wherein the image forming device includes a plurality of dither patterns, each having a substantially same basic tone.

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

a selecting method setting device configured to set at the switching device a selecting method for selecting the one of at least two or more image space frequencies for the output image.

3. An image forming apparatus, comprising:

an image forming device configured to form an output image by at least two or more image space frequencies;

an output size acquisition device configured to recognize a size of an output sheet for the output image;

an image size acquisition device configured to recognize a size of the output image; and

a switching device configured to select one of the at least two or more image space frequencies for the output image according to the size of the output sheet for the output image recognized by the output size acquisition device and the size of the output image recognized by the image size acquisition device and to switch the image forming device so as to form the output image using the one of at least two or more image space frequencies.

6. The image forming apparatus according to claim 3,

wherein the switching device is configured to select the one of the at least two or more image frequency for the output image and to switch the image forming device so as to form the output image using the one of the at least two or more image frequencies in a multi-step manner.

16. The image forming apparatus according to claim 3,

wherein the image forming device includes a plurality of dither patterns, each having a substantially same basic tone.

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

a selecting method setting device configured to set at the switching device a selecting method for selecting the one of at least two or more image space frequencies for the output image.

29. The image forming method according to claim 26,

wherein the selecting step selects the one of at least two or more image space frequencies for the output image in a multi-step manner, and

wherein the forming step forms the output image using the one of at least two or more image space frequencies in the multi-step manner.

30. The image forming method according to claim 27,

wherein the selecting step selects the one of at least two or more image space frequencies for the output image in a multi-step manner;

and

wherein the forming step forms the output image using the one of at least two or more image space frequencies in the multi-step manner.

31. The image forming method according to claim 28,

wherein the selecting step selects the one of at least two or more image space frequencies for the output image in a multi-step manner;

and

wherein the forming step forms the output image using the one of at least two or more image space frequencies in the multi-step manner.

32. The image forming method according to claim 26,

wherein the selecting step includes comparing the size of the output image recognized in the image size recognizing step with a predetermined criterion output image size.

33. The image forming method according to claim 32,

wherein in the selecting step the predetermined criterion output image size is based on a visual characteristic.

34. The image forming method according to claim 26,

wherein the recognizing step includes recognizing a size of a side of the output image in a predetermined direction, and

wherein the selecting step includes selecting the one of at least two or more image space frequencies for the output image based on the size of a side of the output image in the predetermined direction.

35. The image forming method according to claim 26,

wherein the recognizing step includes recognizing sizes of the output image in vertical and horizontal directions, and

wherein the selecting step includes selecting the one of at least two or more image space frequencies for the output image based on the sizes of the output image in vertical and horizontal directions.

36. The image forming method according to claim 26,

wherein the selecting step includes calculating area of the output image from the size of the output image recognized in the recognizing step and selecting the one of at least two or more image space frequencies for the output image based on the area.

37. The image forming method according to claim 26,

wherein when the output image includes a plurality of output images in a same page, the recognizing step includes recognizing respective sizes of the plurality of output images in the same page, the selecting step includes selecting one of at least two or more image space frequencies for the plurality of output images in the same page according to one of the respective sizes of the plurality of output images in the same page, and the image forming steps includes forming each of the plurality of output images in the same page using the one of at least two or more image space frequencies selected in the selecting step for the plurality of output images in the same page.

38. The image forming method according to claim 26,

wherein when the output image includes a plurality of output images in a same file, the recognizing step includes recognizing respective sizes of the plurality of output images in the same file, the selecting step includes selecting one of at least two or more image space frequencies for the plurality of output images in the same file, and the image forming step includes forming each of the plurality of output images in the same file using the one of at least two or more image space frequencies selected in the selecting step for the plurality of output images in the same file.

39. The image forming method according to claim 26,

wherein the image forming step includes forming the output image using a plurality of dither patterns, each having a substantially same basic tone.

40. The image forming method according to claim 27,

wherein the image forming step includes forming the output image using a plurality of dither patterns, each having a same basic tone.

41. The image forming method according to claim 28,

wherein the image forming step includes forming the output image using a plurality of dither patterns, each having a same basic tone.

42. The image forming method according to claim 26,

wherein in the image forming step the plurality of dither patterns have screen angles of predetermined directions respectively that are substantially identical to each other.

43. The image forming method according to claim 27,

wherein in the image forming step the plurality of dither patterns have □

screen angles of predetermined directions respectively that are substantially identical to each other.

44. Then image forming method according to claim 28,

wherein in the image forming step the plurality of dither patterns have screen angles of predetermined directions respectively that are substantially identical to each other.

45. The image forming method according to claim 26, further comprising the step of:

setting a selecting method for selecting the at least two or more image space frequencies for the output image.

46. The image forming method according to claim 27, further comprising the step of:

setting a selecting method for selecting the at least two or more image space frequencies for the output image.

47. The image forming method according to claim 28, further comprising the step of:

setting a selecting method for selecting the at least two or more image space frequencies for the output image.

51. The computer readable medium according to claim 48,

wherein the selecting step selects the one of at least two or more image space frequencies for the output image in a multi-step manner;

and

wherein the forming step forms the output image using the one of at least two or more image space frequencies in the multi-step manner.

52. The computer readable medium according to claim 49,

wherein the selecting step selects the one of at least two or more image space frequencies for the output image in a multi-step manner;

and

wherein the forming step forms the output image using the one of at least two or more image space frequencies in the multi-step manner.

54. The computer readable medium according to claim 48,

wherein the selecting step includes comparing the size of the output image recognized in the image size recognizing step with a predetermined criterion output image size.

55. The computer readable medium according to claim 54,

wherein in the selecting step the predetermined criterion output image size is based on a visual characteristic.

56. The computer readable medium according to claim 48,

wherein the recognizing step includes recognizing a size of a side of the output image in a predetermined direction, and

wherein the selecting step includes selecting the one of at least two or more image space frequencies for the output image based on the size of a side of the output image in the predetermined direction.

57. The computer readable medium according to claim 48,

wherein the recognizing step includes recognizing sizes of the output image in vertical and horizontal directions, and

wherein the selecting step includes selecting the one of at least two or more image space frequencies for the output image based on the sizes of the output image in vertical and horizontal directions.

58. The computer readable medium according to claim 48,

wherein the selecting step includes calculating area of the output image from the size of the output image recognized in the recognizing step and selecting the one of at least two or more image space frequencies for the output image based on the area.

59. The computer readable medium according to claim 48,

wherein when the output image includes a plurality of output images in a same page, the recognizing step includes recognizing respective sizes of the plurality of output images in the same page, the selecting step includes selecting one of at least two or more image space frequencies for the plurality of output images in the same page according to one of the respective sizes of the plurality of output images in the same page, and the image forming steps includes forming each of the plurality of output images in the same page using the one of at least two or more image space frequencies selected in the selecting step for the plurality of output images in the same page.

60. The computer readable medium according to claim 48,

wherein when the output image includes a plurality of output images in a same file, the recognizing step includes recognizing respective sizes of the plurality of output images in the same file, the selecting step includes selecting one of at least two or more image space frequencies for the plurality of output images in the same file, and the image forming step includes forming each of the plurality of output images in the same file using the one of at least two or more image space frequencies selected in the selecting step for the plurality of output images in the same file.

61. The computer readable medium according to claim 48,

wherein the image forming step includes forming the output image using a plurality of dither patters, each having a substantially same basic tone.

62. The computer readable medium according to claim 49,

wherein the image forming step includes forming the output image using a plurality of dither patterns, each having a same basic tone.

64. The computer readable medium according to claim 48,

wherein in the image forming step the plurality of dither patterns have screen angles of predetermined directions respectively that are substantially identical to each other.

65. The computer readable medium according to claim 49,

wherein in the image forming step the plurality of dither patterns have screen angles of predetermined directions respectively that are substantially identical to each other.

67. The computer readable medium according to claim 48, the image forming operation further comprising the step of:

a selecting method for selecting the at least two or more image space frequencies for the output image.

68. The computer readable medium according to claim 49, the image forming operation further comprising the step of:

setting a selecting method for selecting the at least two or more image space frequencies for the output image.

23. An image forming apparatus, comprising:

image forming means for forming an output image by at least two or more image space frequencies;

image size acquisition means for recognizing a size of the output image; and

switching means for selecting one of the at least two or more image frequencies for the output image based on the size of the output image recognized by the image size acquisition means and for switching the image forming means so as to form the output image using the one of the at least two or more image frequencies.

24. An image forming apparatus, comprising:

image forming means for forming an output image by at least two or more image space frequencies;

output size acquisition means for recognizing a size of an output sheet for the output image; and

switching means for selecting one of the at least two or more image space frequencies for the output image based on the size of the output sheet for the output image recognized by the output size acquisition means and for switching the image forming means so as to form the output image using the one of the at least two or more image space frequencies.

25. An image forming apparatus, comprising:

image forming means for forming an output image by at least two or more image space frequencies;

output size acquisition means for recognizing a size of an output sheet for the output image;

image size acquisition means for recognizing a size of the output image; and

switching means for selecting one of the at least two or more image space frequencies for the output image based on the size of the output sheet for the output image recognized by the output size acquisition means and the size of the output image recognized by the image size acquisition means and for switching the image forming means so as to form the output image using the one of at least two or more image space frequencies.

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

recognizing a size of an output image;

selecting one of at least two or more image space frequencies for the output image based on the size of the output image recognized in the recognizing step; and

forming the output image using the one of at least two or more image space frequencies selected in the selecting step.

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

recognizing a size of an output sheet for an output image;

selecting one of at least two or more image space frequencies for the output image based on the size of the output sheet for the output image recognized in the recognizing step; and

forming the output image using the one of at least two or more image space frequencies selected in the selecting step.

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

recognizing a size of an output image;

recognizing a size of an output sheet for the output image;

selecting one of at least two or more image space frequencies for the output image based on the size of the output image recognized in the output image size recognizing step and the size of the output sheet for the output image recognized in the output sheet size recognizing step; and

forming the output image using the one of at least two or more image space frequencies selected in the selecting step.

48. A computer readable medium storing computer program instructions which when executed by a computer performs an image forming operation comprising the steps of:

recognizing a size of an output image;

selecting one of at least two or more image space frequencies for the output image based on the size of the output image recognized in the recognizing step; and

forming the output image using the one of at least two or more image space frequencies selected in the selecting step.

49. A computer readable medium storing computer program instructions which when executed by a computer performs an image forming operation comprising the steps of:

recognizing a size of an output sheet for an output image;

selecting one of at least two or more image space frequencies for the output image based on the size of the output sheet for the output image recognized in the recognizing step; and

forming the output image using the one of at least two or more image space frequencies selected in the selecting step.

50. A computer readable medium storing computer program instructions which when executed by a computer performs an image forming operation comprising the steps of:

recognizing a size of an output image;

recognizing a size of an output sheet for the output image;

selecting one of at least two or more image space frequencies for the output image based on the size of the output image recognized in the output image size recognizing step and the size of the output sheet for the output image recognized in the output sheet size recognizing step; and

forming the output image using the one of at least two or more image space frequencies selected in the selecting step.

53. The computer readable medium according to claim 50,

wherein the selecting step selects the one of at least two or more image space frequencies for the output image in a multi-step manner;

and

wherein the forming step forms the output image using the one of at least two or more image space frequencies in the multi-step manner.

63. The computer readable medium according to claim 50,

wherein the image forming step includes forming the output image using a plurality of dither patterns, each having a same basic tone.

66. The computer readable medium according to claim 50,

wherein in the image forming step the plurality of dither patterns have screen angles of predetermined directions respectively that are substantially identical to each other.

69. The computer readable medium according to claim 50, the image forming operation further comprising the step of:

setting a selecting method for selecting the at least two or more image space frequencies for the output image.

70. An image forming apparatus, comprising:

an image forming device configured to form an output image by at least two or more image space frequencies;

an image size acquisition device configured to recognize a size of the output image;

image contents acquisition device configured to recognize contents of the output image; and

switching device configured to select one of the at least two or more image frequencies for the output image according to the size of the output image recognized by the image size acquisition device and the contents of the output image recognized by the image contents acquisition device and to switch the image forming device so as to form the output image using the one of the at least two or more image frequencies.

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

recognizing a size of an output image;

recognizing contents of the output image;

selecting one of at least two or more image space frequencies for the output image based on the size of the output image recognized in the image size recognizing step and the contents of the output image recognized in the image contents recognizing step; and

forming the output image using the one of at least two or more image space frequencies selected in the selecting step.

72. A computer readable medium storing computer program instructions which when executed by a computer performs an image forming operation comprising the steps of:

recognizing a size of an output image;

recognizing contents of the output image;

selecting one of at least two or more image space frequencies for the output image based on the size of the output image recognized in the image size recognizing step and the contents of the output image recognized in the image contents recognizing step; and

forming the output image using the one of at least two or more image space frequencies selected in the selecting step.