Ink-supply system for a dot matrix printer

• US 5,158,377 A
• Filed: 11/30/1990
• Issued: 10/27/1992
• Est. Priority Date: 05/22/1984
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Suzuki, Takashi, Miyazawa, Yoshinori, Matsuzawa, Masanao
• Primary Examiner(s): WIECKING, DAVID
• Application Number:
  US07/620,411
• Time in Patent Office: 697 Days
• Field of Search: 400/124 IW, 400/470, 400/471, 400/471.1, 400/126, 346/140 R, 346/140 PD, 101/97, 101/98, 101/333, 101/335, 101/364
• US Class Current: 400/124.1
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/255 Arrangement of the print ends of the wires
• CPC Class Codes: B41J 2/305 Ink supply apparatus ink ribbons, ink-ribbon mechanisms B41J31/00 - B41J35/00

Abstract

An ink-supply system for a dot matrix printer including an ink-supply tank formed with an ink supply delivery port having an opening for passage of ink from the ink-supply tank. An ink absorbing member formed of a porous material is mounted within the ink-supply tank and compressed relative to at least another region of the ink absorbing member at least in the region thereof facing the opening of the ink supply delivery port.

Claims

1. A dot matrix printer comprising:

printing means for applying ink in a dot matrix to effect printing; and

an ink supply means for delivering ink to said printing means comprising;

an ink-supply tank;

an ink absorbing member formed of a porous material contained within said ink-supply tank; and

means projecting into said ink-supply tank and formed with an opening for receiving and transmitting ink from said ink absorbing member for delivery to said printer head, said ink absorbing member having a surface facing said opening, at least the entire region of said ink absorbing member of said surface facing the opening of said ink receiving and transmitting means being compressed so as to change the porosity of said region relative to at least another region of the ink absorbing member.

2. The dot matrix printer of claim 1, wherein said ink-supply tank includes a wall facing said ink receiving and transmitting means, said ink absorbing member being compressingly contained in the space intermediate said wall and said ink receiving and transmitting means.

3. The dot matrix printer of claim 2, wherein said wall of said ink-supply tank facing said ink receiving and transmitting means is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member.

4. The dot matrix printer of claim 2, wherein said ink absorbing member carries substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank, said ink-supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface.

5. The dot matrix printer of claim 4, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

6. The dot matrix printer of claim 4, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

7. The dot matrix printer of claim 6, wherein said wall of said ink-supply tank facing said ink receiving and transmitting means is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member, at least a portion of said projections extending from the inner wall surface of said cover means.

8. The dot matrix printer of claim 4, wherein said projections are formed in an inner wall surface of said wall of said ink-supply tank facing said ink receiving and transmitting means.

9. The dot matrix printer of claim 8, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

10. The dot matrix printer of claim 1, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

11. The dot matrix printer of claim 1, wherein said ink absorbing member comprises at least two separate porous members disposed as stacked layers, one of said porous members which is closer to said ink receiving and transmitting means being made of a porous material having a smaller average pore size than the porous material of the other porous member more remote from said ink receiving and transmitting means.

12. The dot matrix printer of claim 1 wherein the ink absorbing member is held in compression in the vicinity of said ink receiving and transmitting means by said ink-supply tank.

13. A dot matrix printer comprising:

printing means for applying ink in a dot matrix to effect printing; and

an ink supply means for delivering ink to said printing means comprising;

an ink-supply tank;

an ink absorbing member formed of a porous material contained within said ink-supply tank, said ink absorbing member carrying substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank; and

means projecting into said ink-supply tank and formed with an opening for receiving and transmitting ink from said ink absorbing member for delivery to said printer head, said ink absorbing member having a region facing said opening, at least the region of said ink absorbing member facing the opening of said ink receiving and transmitting means being compressed relative to at least another region of the ink absorbing member.

14. The dot matrix printer of claim 13, said ink supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

15. A dot matrix printer, comprising:

printing means for applying ink in a dot matrix to effect printing; and

an ink supply means for delivering ink to said printing means comprising;

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank; and

an ink absorbing member substantially filling said ink-supply tank and being formed of a porous material mounted within said tank, said ink absorbing member having a region facing said opening and being compressingly contained by the ink-supply tank against the ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member.

16. The dot matrix printer of claim 15, wherein said ink-supply tank includes a wall facing said ink-supply delivery port, at least a portion of the ink absorbing member being compressingly contained in the space between said ink-supply delivery port and said wall of said ink tank.

17. The dot matrix printer of claim 16, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member.

18. The dot matrix printer of claim 15, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

19. The dot matrix printer of claim 15, wherein said ink absorbing member comprises at least two separate porous members disposed as stacked layers, one of said porous members which is closer to said ink-supply delivery port being made of a porous material having a smaller average pore size than the porous material of the other porous member more remote from said ink-supply delivery port.

20. The dot matrix printer of claim 16, wherein said ink absorbing member carries substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank, said ink-supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface.

21. The dot matrix printer of claim 20, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

22. The dot matrix printer of claim 21, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member, said ink-supply tank cover including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface, at least a portion of said projections extending from the inner wall surface of said cover.

23. The dot matrix printer of claim 20, wherein said projections are formed in an inner wall surface of said wall of said ink-supply tank facing said ink-supply delivery port.

24. The dot matrix printer of claim 23, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

25. The dot matrix printer of claim 20, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

26. A dot matrix printer comprising:

printing means for applying ink in a dot matrix to effect printing; and

an ink supply means for delivering ink to said printing means comprising;

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank; and

an ink absorbing member formed of a porous material mounted within said tank, said ink absorbing member having a region facing said opening and being compressingly contained by the ink-supply tank against the ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member, said ink absorbing member carrying substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank.

27. The dot matrix printer of claim 26, said ink supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

28. A dot matrix printer, comprising:

printing means for applying ink in a dot matrix to effect printing; and

an ink supply means for delivering ink to said printing means comprising;

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank and a wall facing said ink-supply delivery port; and

an ink absorbing member substantially filling said ink-supply tank and being formed of a porous material mounted within said tank, said ink absorbing member having a region forming said opening and being compressingly contained in the space defined between said wall facing said ink-supply delivery port and said ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member.

29. The dot matrix printer of claim 28, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member.

30. The dot matrix printer of claim 28, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

31. A dot matrix printer comprising:

printing means for applying ink in a dot matrix to effect printing; and

an ink supply means for delivering ink to said printing means comprising;

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank and a wall facing said ink-supply delivery port; and

an ink absorbing member formed of a porous material mounted within said tank, said ink absorbing member having a region forming said opening and being compressively contained in the space defined between said wall facing said ink-supply delivery port and said ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member, said ink absorbing member carrying substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank.

32. The dot matrix printer of claim 31, said ink supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface and including means for providing ambient air to the space betwen said ink absorbing member and said wall surface.

33. The dot matrix printer of claim 32, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member, at least a portion of said projections extending from the inner wall surface of said cover means.

34. The dot matrix printer of claim 31, and including an inner wall surface of said wall of said ink-supply tank facing said ink-supply delivery port having projections to provide a space between said ink absorbing member and said wall surface.

35. The dot matrix printer of claim 34, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

36. The dot matrix printer of claim 31, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

37. A dot matrix printer comprising:

printing means for applying ink in a dot matrix to effect printing; and

an ink supply means for delivering ink to said printing means comprising;

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank; and

an ink absorbing member formed of a porous material mounted within said ink-supply tank and having a surface facing said opening of said ink-supply delivery port, at least the entire region of said ink absorbing member at said surface facing said opening of said ink-supply delivery port being compressed so as to change the porosity of said region relative to at least another region of the ink absorbing member.

38. The dot matrix printer of claim 37, wherein said ink-supply tank includes a wall facing said ink-supply delivery port, at least a portion of the ink absorbing member being compressingly contained in the space between said ink-supply delivery port and said wall of said ink tank.

39. The dot matrix printer of claim 38, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply the compressive force to effect compression of said ink absorbing member.

40. The dot matrix printer of claim 38, wherein said ink absorbing member carries substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the desired capacity of the ink-supply tank, said ink-supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface.

41. The dot matrix printer of claim 40, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

42. The dot matrix printer of claim 41, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply the compressive force to effect compression of said ink absorbing member, at least a portion of said projections extending from the inner wall, surface of said cover means.

43. The dot matrix printer of claim 40, wherein said projections are formed in an inner wall surface of said wall of said ink-supply tank facing said ink-supply delivery port.

44. The dot matrix printer of claim 43, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

45. The dot matrix printer of claim 40, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

46. The dot matrix printer of claim 37, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

47. The dot matrix printer of claim 37, wherein said ink absorbing member comprises at least two separate porous members disposed as stacked layers, one of said porous members which is closer to said ink-supply delivery port being made of a porous material having a smaller average pore size than the porous material of the other porous member more remote from said ink-supply delivery port.

48. The dot matrix printer of claim 37, wherein the ink absorbing member is held in compression in the vicinity of said ink-supply delivery port by said ink-supply tank.

49. A dot matrix printer comprising:

printing means for applying ink in a dot matrix to effect printing; and

an ink supply means for delivering ink to said printing means comprising;

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank; and

an ink absorbing member formed of a porous material mounted within said ink-supply tank and having a region facing said opening of said ink-supply delivery port, at least the region of said ink absorbing member facing said opening of said ink-supply delivery port being compressed relative to at least another region of the ink absorbing member, said ink absorbing member carrying substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank.

50. The dot matrix printer of claim 49, said ink supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

51. A method for supplying ink for a dot matrix printer comprising:

providing an ink absorbing member formed of a porous material mounted within an ink-supply tank and substantially filling the ink-supply tank;

providing means projecting into said ink-supply tank and having an opening for receiving and transmitting ink from said ink absorbing member;

compressing said ink absorbing member relative to at least another region thereof at least in the region of the ink absorbing member facing the opening of said ink receiving and transmitting means; and

withdrawing said ink from said ink-supply tank through the opening of said ink receiving and transmitting means.

52. The method of claim 51, wherein said compression of said ink absorbing member is effected by the securing of a cover means which bears on the ink absorbing member and faces said ink receiving and transmitting means.

53. The method of claim 51, including the further step of applying ink to said ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

54. The method of claim 51, including the step of forming said ink absorbing member of at least two separate porous members disposed as stacked layers, one of said porous members which is closer to said ink receiving and transmitting means being made of a porous material having a smaller average pore size than the porous material of the other porous member more remote from said ink receiving and transmitting means.

55. The method of claim 51, wherein the step of compressing said ink-absorbing member is by the engagement thereof by said ink tank.

56. A method for supplying ink for a dot matrix printer comprising the steps of:

providing an ink absorbing member formed of a porous material mounted within an ink-supply tank;

providing means projecting into said ink-supply tank and having an opening for receiving and transmitting ink from said ink absorbing member;

providing a space between at least an inner wall surface of the ink-supply tank and the ink absorbing member, and including the further step of providing ambient air to said space;

compressing said ink absorbing member relative to at least another region thereof at least in the entire region at the surface of the ink absorbing member facing the opening of said ink receiving and transmitting means so as to change the porosity of the compressed region; and

withdrawing said ink from said ink-supply tank through the opening of said ink receiving and transmitting means.

57. A method for supplying ink for a dot matrix printer comprising:

providing an ink absorbing member formed of a porous material mounted within an ink-supply tank;

applying ink to said ink-supply tank so that said ink absorbing member carries substantially all of the ink that said ink-supply tank was designed to hold;

providing means projecting into said ink-supply tank and having an opening for receiving and transmitting ink from said in absorbing member;

compressing said ink absorbing member relative to at least another region thereof at least in the region of the ink absorbing member facing the opening of said ink receiving and transmitting means; and

withdrawing said ink from said ink-supply tank through the opening of said ink receiving and transmitting means.

58. An ink-supply system for a dot matrix printer head comprising:

an ink-supply tank;

an ink absorbing member formed of a porous material contained within said ink-supply tank; and

means projecting into said ink-supply tank and formed with an opening for receiving and transmitting ink from said ink absorbing member for delivery to said printer head, said ink absorbing member having a surface facing said opening, at least the entire region of said ink absorbing member at said surface facing the opening of said ink receiving and transmitting means being compressed so as to change the porosity of said region relative to at least another region of the ink absorbing member.

59. The ink-supply system of claim 58, wherein said ink-supply tank includes a wall facing said ink receiving and transmitting means, said ink absorbing member being compressingly contained in the space intermediate said wall said ink receiving and transmitting means.

60. The ink-supply system of claim 59, wherein said wall of said ink-supply tank facing said ink receiving and transmitting means is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member.

61. The ink-supply system of claim 59, wherein said ink absorbing member carries substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank, said ink-supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface.

62. The ink-supply system of claim 61, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

63. The ink-supply system of claim 61, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

64. The ink-supply system of claim 63, wherein said wall of said ink-supply tank facing said ink receiving and transmitting means is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member, at least a portion of said projections extending from the inner wall surface of said cover means.

65. The ink-supply system of claim 61, wherein said projections are formed in an inner wall surface of said wall of said ink-supply tank facing said ink receiving and transmitting means.

66. The ink-supply system of claim 65, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

67. The ink-supply system of claim 58, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

68. The ink-supply system of claim 58, wherein said ink absorbing member comprises at least two separate porous members disposed as stacked layers, one of said porous members which is closer to said ink receiving and transmitting means being made of a porous material having a smaller average pore size than the porous material of the other porous member more remote from said ink receiving and transmitting means.

69. The ink-supply system of claim 58, wherein the ink absorbing member is held in compression in the vicinity of said ink receiving and transmitting means by said ink-supply tank.

70. An ink supply system for a dot matrix printer head comprising:

an ink-supply tank;

an ink absorbing member formed of a porous material contained within said ink-supply tank, said ink absorbing member carrying substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank; and

means projecting into said ink-supply tank and formed with an opening for receiving and transmitting ink from said ink absorbing member for delivery to said printer head, said ink absorbing member having a region facing said opening, at least the region of said ink absorbing member facing the opening of said ink receiving and transmitting means being compressed relative to at least another region of the ink absorbing member.

71. The ink supply system of claim 70, said ink supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

72. An ink-supply system for a dot matrix printer, comprising:

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank; and

an ink absorbing member substantially filling the ink-supply tank and being formed of a porous material mounted within said tank, said ink absorbing member having a region facing said opening and being compressingly contained by the ink-supply tank against the ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member.

73. The ink-supply system of claim 72, wherein said ink-supply tank includes a wall facing said ink-supply delivery port, at least a portion of the ink absorbing member being compressingly contained in the space between said ink-supply delivery port and said wall of said ink tank.

74. The ink-supply system of claim 73, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member.

75. The ink-supply system of claim 72, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

76. The ink-supply system of claim 72, wherein said ink absorbing member comprises at least two separate porous members disposed as stacked layers, one of said porous members which is closer to said ink-supply delivery port being made of a porous material having a smaller average pore size than the porous material of the other porous member more remote from said ink-supply delivery port.

77. An ink-supply system for a dot matrix printer, comprising:

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank; and

an ink absorbing member formed of a porous material mounted within said tank, said ink absorbing member having a region facing said opening and being compressingly contained by the ink-supply tank against the ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member, said ink absorbing member carrying substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank.

78. The ink supply system of claim 77, said ink supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

79. The ink-supply system of claim 78, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply the compressive force to effect compression of said ink absorbing member, at least a portion of said projections extending from the inner wall surface of said cover means.

80. The ink-supply system of claim 77, and including an inner wall surface of said wall of said ink-supply tank facing said ink-supply delivery port having projections to provide a space between said ink absorbing member and said wall surface.

81. The ink-supply system of claim 80, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

82. The ink-supply system of claim 77, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

83. An ink-supply system for a dot matrix printer, comprising:

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank;

an ink absorbing member formed of a porous material mounted within said tank, said ink absorbing member having a region facing said opening and being compressingly contained by the ink-supply tank against the ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member; and

said ink absorbing member substantially filling said ink-supply tank, said ink-supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface.

84. The ink-supply system of claim 83, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

85. An ink-supply system for a dot matrix printer, comprising:

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank and a wall facing said ink-supply delivery port; and

an ink absorbing member substantially filling said ink-supply tank and being formed of a porous material mounted within said tank, said ink absorbing member having a region facing said opening and being compressingly contained in the space defined between said wall facing said ink-supply delivery port and said ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member.

86. The ink-supply system of claim 85, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member.

87. The ink-supply system of claim 85, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

88. An ink-supply system for a dot matrix printer, comprising:

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank and a wall facing said ink-supply delivery port; and

an ink absorbing member formed of a porous material mounted within said tank, said ink absorbing member having a region facing said opening and being compressingly contained in the space defined between said wall facing said ink-supply delivery port and said ink-supply delivery port so that at least the region of the ink absorbing member facing said opening is compressed relative to at least another region of the ink absorbing member, said ink absorbing member carrying substantially all of the ink in said ink-supply tank when saidd ink-supply tank is filled to the designed capacity of the ink-supply tank.

89. The ink suppy system of claim 88, said ink supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

90. The ink-supply system of claim 89, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member, at least a portion of said projections extending from the inner wall surface of said cover means.

91. The ink-supply system of claim 88, and including an inner wall surface of said wall of said ink-supply tank facing said ink-supply deliverly port having projections to provide a space between said ink absorbing member and said wall surface.

92. The ink-supply system of claim 91, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

93. The ink-supply system of claim 88, and including ink impregenated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

94. An ink-supply system for a dot matrix printer comprising:

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank; and

an ink absorbing member formed of a porous material mounted within said ink-supply tank and having a surface facing said opening of said ink-supply delivery port, at least the entire region of said ink absorbing member at said surface facing said opening of said ink-supply delivery port being compressed so as to change the porosity of said region relative to at least another region of said ink absorbing member.

95. The ink-supply system of claim 94, wherein said ink-supply tank includes a wall facing said ink-supply delivery port, at least a portion of the ink absorbing member being compressingly contained in the space between said ink-supply delivery port and said wall of said ink tank.

96. The ink-supply system of claim 95, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member.

97. The ink-supply system of claim 95, wherein said ink absorbing member carries substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank, said ink-supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface.

98. The ink-supply system of claim 97, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

99. The ink-supply system of claim 98, wherein said wall of said ink-supply tank facing said ink-supply delivery port is a cover means bearing on said ink absorbing member when assembled to said ink-supply tank to at least in part apply a compressive force to effect compression of said ink absorbing member, at least a portion of said projections extending from the inner wall surface of said cover means.

100. The ink-supply system of claim 97, wherein said projections are formed in an inner wall surface of said wall of said ink-supply tank facing said ink-supply delivery port.

101. The ink-supply system of claim 100, and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

102. The ink-supply system of claim 97, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

103. The ink-supply system of claim 94, and including ink impregnated in the ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

104. The ink-supply system of claim 94, wherein said ink absorbing member comprises at least two separate porous members disposed as stacked layers, one of said porous members which is closer to said ink-supply delivery port being made of a porous material having a smaller average pore size than the porous material of the other porous member more remote from said ink-supply delivery port.

105. The ink-supply system of claim 94, wherein the ink absorbing member is held in compression in the vicinity of said ink-supply delivery port by said ink-supply tank.

106. An ink-supply system for a dot matrix printer comprising:

an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from said ink-supply tank; and

an ink absorbing member formed of a porous material mounted within said ink-supply tank and having a region facing said opening of said ink-supply delivery port, at least the region of said ink absorbing member facing said opening of said ink-supply delivery port being compressed relative to at least another region of said ink absorbing member, said ink absorbing member carrying substantially all of the ink in said ink-supply tank when said ink-supply tank is filled to the designed capacity of the ink-supply tank.

107. The ink supply system of claim 106, said ink-supply tank including an inner wall surface having projections to provide a space between said ink absorbing member and said wall surface and including means for providing ambient air to the space between said ink absorbing member and said wall surface.

108. A method for supplying ink to a dot matrix printer comprising:

providing an ink absorbing member formed of a porous material within an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from the ink-supply tank;

compressing said ink absorbing member relative to at least another region thereof at least in the entire region at a surface of said ink absorbing member facing said opening of said ink-supply delivery port so as to change the porosity of said compressed region; and

withdrawing ink from said ink-supply tank through the opening in said ink-supply delivery port.

109. The method of claim 108, wherein said compression of said ink absorbing member is effected by the securing of a cover means which bears on the ink absorbing member and faces said ink-supply delivery port.

110. The method of claim 108, including the further step of applying ink to said ink absorbing member under a pressure sufficiently low to substantially eliminate air bubbles in the ink absorbing member.

111. The method of claim 108, including the step of forming said ink absorbing member of at least two separate porous members disposed as stacked layers, one of said porous members which is closer to said ink-supply delivery port being made of a porous material having a smaller average pore size than the porous material of the other porous member more remote from said ink-supply delivery port.

112. The method of claim 108, wherein the step of compressing said ink-absorbing member is by the engagement thereof by said ink tank.

113. A method for supplying ink to a dot matrix printer comprising the steps of:

providing an ink absorbing member formed of a porous material within an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from the ink-supply tank, said ink absorbing member being selected to substantially fill the ink-supply tank;

compressing said ink absorbing member relative to at least another region thereof at least in the region of said ink absorbing member facing said opening of said ink-supply delivery port; and

providing a space between at least an inner wall surface of the ink-supply tank and the ink absorbing member, and including the further step of providing ambient air to said space;

withdrawing ink from said ink-supply tank through the opening in said ink-supply delivery port.

114. A method for supplying ink to a dot matrix printer comprising the steps of:

providing an ink absorbing member formed of a porous material within an ink-supply tank formed with an ink-supply delivery port having an opening for the passage of ink from the ink-supply tank;

applying ink to said ink-supply tank so that said ink absorbing member carrier substantially all of the ink that said ink-supply tank was designed to hold;

compressing said ink absorbing member relative to at least another region thereof at least in the region of said ink absorbing member facing said opening of said ink-supply delivery port; and

withdrawing ink from said ink-supply tank through the opening in said ink-supply delivery port.