Ink-jet recording apparatus and method using asynchronous masks

• US 5,818,474 A
• Filed: 06/27/1994
• Issued: 10/06/1998
• Est. Priority Date: 06/30/1993
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Otsuka, Naoji, Arai, Atsushi, Takahashi, Kiichiro, Yano, Kentaro, Nakata, Kazuhiro, Iwasaki, Osamu, Kanematsu, Daigoro, Sasaki, Masao
• Primary Examiner(s): Barlow, Jr., John E.
• Assistant Examiner(s): Hallacher, Craig A.
• Application Number:
  US08/266,498
• Time in Patent Office: 1,562 Days
• Field of Search: 347/12, 347/13, 347/15, 347/43, 347/115, 347/172, 347/232, 358/298, 395/109
• US Class Current: 347/15
• CPC Class Codes: G06K 15/107 Mask selection

Abstract

Random masks each having a given size and defining a random array of non-record pixel locations and record pixel locations are placed in association with record areas in mask registers. Using the placed masks, record data is thinned-out and supplied to a recording head. An image is then recorded. Thus, since thinning-out masks do not have periodicity, any inherent density nonuniformity loses periodicity. Consequently, high-definition images can be produced.

Claims

1. A recording apparatus for recording using a recording head having a plurality of recording elements, said apparatus comprising:

scan controlling means for controlling the recording head to scan the same record area of a recording medium a plurality of times;

producing means for producing a plurality of random masks, each random mask having a predetermined size and defining a random arrangement of non-record pixel locations and record pixel locations;

thinning-out means for thinning out record data using said random masks produced by said producing means, said random masks being utilized as thinning-out masks for each record area; and

record controlling means for forming thinned-out images by printing the record data thinned out by said thinning-out means, during respective scans, and thus completing an image.

2. A recording apparatus according to claim 1, wherein said scan controlling means controls the recording head to scan the same record area of the recording medium a plurality of times by changing divided areas of the recording head.

3. A recording apparatus according to claim 1, further comprising storage means for storing a plurality of random masks.

4. A recording apparatus according to claim 1, further comprising:

checking means for checking whether or not said random masks produced by said producing means are consistent with a predetermined mask; and

prohibiting means for prohibiting certain random masks from being used as thinning-out masks when the certain random masks are consistent with said predetermined mask.

5. A recording apparatus according to claim 1, further comprising the recording head, wherein said recording head discharges ink from a plurality of ink-jet nozzles.

6. A recording apparatus according to claim 5, wherein said recording head discharges the ink by way of heat.

7. A recording apparatus according to claim 1, wherein said recording apparatus is incorporated in a copying machine.

8. A recording apparatus according to claim 1, wherein said recording apparatus is incorporated in a facsimile machine.

9. A recording apparatus according to claim 1, wherein said recording apparatus is incorporated in a computer terminal.

10. A recording apparatus for recording using a recording head having a plurality of recording elements, said apparatus comprising:

scan controlling means for controlling the recording head to scan the same record area of a recording medium a plurality of times;

selecting means for randomly selecting a plurality of masks each having a predetermined size and defining an arrangement of non-record pixel locations and record pixel locations;

thinning-out means for thinning out record data using said masks selected by said selecting means, said randomly-selected masks being utilized as thinning-out masks for each record area; and

record controlling means for forming thinned-out images by recording the record data thinned out by said thinning-out means, during respective scans, and thus completing an image.

11. A recording apparatus according to claim 10, further comprising the recording head, wherein said recording head discharges ink from a plurality of ink-jet nozzles.

12. A recording apparatus according to claim 11, wherein said recording head discharges the ink by way of heat.

13. A recording apparatus according to claim 10, wherein said recording apparatus is incorporated in a copying machine.

14. A recording apparatus according to claim 10, wherein said recording apparatus is incorporated in a facsimile machine.

15. A recording apparatus according to claim 10, wherein said recording apparatus is incorporated in a computer terminal.

16. A recording apparatus for recording using a recording head having a plurality of recording elements, said apparatus comprising:

scan controlling means for controlling the recording head to scan the same record area of a recording medium a plurality of times;

producing means for producing a plurality of random masks each having a predetermined size and defining a random array of non-record pixel locations and record pixel locations;

selecting means for randomly selecting a plurality of masks each having a predetermined size and defining an array of non-record pixel locations and record pixel locations;

synthesizing means for synthesizing said masks randomly selected by said selecting means with said random masks produced by said producing means so as to produce synthetic masks providing different thinning-out ratios from said random masks;

thinning-out means for thinning out record data using said synthetic masks produced by said synthesizing means, said synthetic masks being utilized as thinning-out masks for each record area; and

recording controlling means for forming thinned-out images by recording the record data thinned out by said thinning-out means, during respective scans, and thus completing an image.

17. A recording apparatus according to claim 16, further comprising the recording head, wherein said recording head discharges ink from a plurality of ink-jet nozzles.

18. A recording apparatus according to claim 17, wherein said recording head discharges the ink by way of heat.

19. A recording apparatus according to claim 16, wherein said recording apparatus is incorporated in a copying machine.

20. A recording apparatus according to claim 16, wherein said recording apparatus is incorporated in a facsimile machine.

21. A recording apparatus according to claim 16, wherein said recording apparatus is incorporated in a computer terminal.

22. A recording apparatus for recording using a recording head having a plurality of recording elements, said apparatus comprising:

scan controlling means for controlling the recording head to scan a same record area of a plurality of record areas of a recording medium a plurality of times;

specifying means for specifying a plurality of groups of different masks, each group corresponding to a record area of the plurality of record areas and each of the different masks defining an arrangement of non-record pixel locations and record pixel locations, for use as thinning-out masks for a respective record area, wherein groups of masks corresponding to different record areas are different from each other;

thinning-out means for thinning out record data using said different masks specified by said specifying means; and

record controlling means for forming thinned-out images by recording the record data thinned out by said thinning-out means, during respective scans controlled by said scan controlling means, and thus completing an image.

23. A recording apparatus according to claim 22, wherein said specifying means specifies certain ones of said masks for each record scan.

24. A recording apparatus according to claim 22, wherein said specifying means specifies certain ones of said masks for respective divided areas of the recording head.

25. A recording apparatus according to claim 22, wherein said specifying means varies periodicities in specifying said masks.

26. A recording apparatus according to claim 22, wherein said specifying means produces a plurality of complementary masks using a single mask.

27. A recording apparatus according to claim 22, further comprising the recording head, wherein said recording head discharges ink from a plurality of ink-jet nozzles.

28. A recording apparatus according to claim 27, wherein said recording head discharges the ink by way of heat.

29. A recording apparatus according to claim 22, wherein said recording apparatus is incorporated in a copying machine.

30. A recording apparatus according to claim 22, wherein said recording apparatus is incorporated in a facsimile machine.

31. A recording apparatus according to claim 22, wherein said recording apparatus is incorporated in a computer terminal.

32. A recording method for recording using a recording head having a plurality of recording elements, said method comprising the steps of:

producing a plurality of random masks each having a predetermined size and defining a random arrangement of non-record pixel locations and record pixel locations;

thinning out record data using the random masks produced in the producing step, the random masks being utilized as thinning-out masks for each record area; and

controlling the recording head to scan the same record area of a recording medium a plurality of times, forming thinned-out images by recording thinned-out record data during respective scans, and thus completing an image.

33. A recording method according to claim 32, wherein during image forming the recording head discharges ink from a plurality of ink-jet nozzles.

34. A recording method according to claim 33, wherein the recording head discharges the ink by way of heat.

35. A recording method for recording using a recording head having a plurality of recording elements, said method comprising the steps of:

randomly selecting a plurality of masks each having a predetermined size and defining an arrangement of non-record pixel locations and record pixel locations;

thinning out record data using the masks selected in said selecting step, said random masks being utilized as thinning-out masks for each record area; and

controlling the recording head to scan the same record area of a recording medium a plurality of times, forming thinned-out images by recording thinned-out record data during respective scans, and thus completing an image.

36. A recording method according to claim 35, wherein during image forming the recording head discharges ink from a plurality of ink-jet nozzles.

37. A recording method according to claim 36, wherein the recording head discharges the ink by way of heat.

38. A recording method for recording using a recording head having a plurality of recording elements, said method comprising the steps of:

producing a plurality of random masks each having a predetermined size and defining a random arrangement of non-record pixel locations and record pixel locations;

randomly selecting a plurality of prestored masks each having a predetermined size and defining an array of non-record pixel locations and record pixel locations;

synthesizing the selected prestored masks with the produced random masks so as to produce synthetic masks providing different thinning-out ratios from the random masks;

thinning out record data using the synthetic masks, the synthetic masks being utilized as thinning-out masks for each record area; and

controlling the recording head to scan the same record area of a recording medium a plurality of times, forming thinned-out images by recording thinned-out record data during respective scans, and thus completing an image.

39. A recording method according to claim 38, wherein during image forming the recording head discharges ink from a plurality of ink-jet nozzles.

40. A recording method according to claim 39, wherein the recording head discharges the ink by way of heat.

41. A recording method for recording using a recording head having a plurality of recording elements, said method comprising the steps of:

specifying a plurality of groups of different masks, each group corresponding to a record area of the plurality of record areas and each of the different masks defining an arrangement of non-record pixel locations and record pixel locations, for use as thinning-out masks for a respective record area, wherein groups of masks corresponding to different record areas are different from each other;

thinning out record data using the specified different masks; and

controlling the recording head to scan the same record area of a recording medium a plurality of times, forming thinned-out images by recording thinned-out record data during respective scans, and thus completing an image.

42. A recording method according to claim 41, wherein during image forming the recording head discharges ink from a plurality of ink-jet nozzles.

43. A recording method according to claim 42, wherein the recording head discharges the ink by way of heat.

44. A recording apparatus for recording using a recording head having a plurality of recording elements, said apparatus comprising:

scan controlling means for controlling the recording head to scan a same record area of a plurality of record areas of a recording medium a plurality of times;

specifying means for specifying different kinds of masks, each of which defines an arrangement of non-record pixel locations and record pixel locations, for use as thinning-out masks for respective record areas, wherein said specifying means varies periodicities in specifying said masks;

thinning-out means for thinning out record data using said different kinds of masks specified by said specifying means; and

record controlling means for forming thinned-out images by recording the record data thinned out by said thinning-out means, during respective scans, and thus completing an image.