초록 ▼

A pressure adjustment mechanism can provide ink to a subtank with the inside of the subtank being opened to outside air, by using a low driving force. A liquid tank holds liquid to be used by a printing apparatus. The liquid tank has a structure in which a capacity of the liquid tank can be changed

A pressure adjustment mechanism can provide ink to a subtank with the inside of the subtank being opened to outside air, by using a low driving force. A liquid tank holds liquid to be used by a printing apparatus. The liquid tank has a structure in which a capacity of the liquid tank can be changed so as to generate a negative pressure in the liquid tank. The liquid tank includes a case having an opening at one side of the tank, and a flexible film that covers the opening, and a compressed spring in the tank for pressing the film outwards.

대표청구항 ▼

The invention claimed is: 1. An inkjet apparatus, comprising: an inkjet head; and a liquid tank that holds liquid supplied from a cartridge and that supplies liquid to the inkjet head, the liquid tank including: a flexible film configured to close an opening of a case forming the liquid tank; a spr

The invention claimed is: 1. An inkjet apparatus, comprising: an inkjet head; and a liquid tank that holds liquid supplied from a cartridge and that supplies liquid to the inkjet head, the liquid tank including: a flexible film configured to close an opening of a case forming the liquid tank; a spring member, provided inside the liquid tank, configured to press the flexible film in a direction towards the outside of the liquid tank to generate a negative pressure from a state having no negative pressure in the liquid tank; a pressing member provided outside the liquid tank, configured to press the flexible film against the spring member in the liquid tank from the outside of the liquid tank to change the amount of the negative pressure in the liquid tank; and a liquid providing opening configured to receive liquid from the cartridge into the liquid tank. 2. The inkjet apparatus according to claim 1, the liquid tank further including: an air releasing opening that is opened and closed so that an inside of the liquid tank is opened and closed to outside air, wherein the capacity of the liquid tank is decreased by pressing the flexible film by the pressing member in a state having no negative pressure in the liquid tank while the air releasing opening is opened, and thereafter, the liquid is provided inside the liquid tank, the air releasing opening is closed and the pressing member is released so that the capacity of the liquid tank is increased by a pressure of the spring member and a negative pressure is generated in the liquid tank. 3. The inkjet apparatus according to claim 2, the liquid tank further comprising an air releasing valve, provided at the air releasing opening, for keeping the air releasing opening closed. 4. The inkjet apparatus according to claim 2, wherein a position of the liquid providing opening is lower than a position of the air releasing opening. 5. The inkjet apparatus according to claim 1, the liquid tank further comprising a reverse flow prevention valve configured to prevent liquid from flowing in reverse from the liquid providing opening. 6. The inkjet apparatus according to claim 5, wherein the reverse flow prevention means include valve means for preventing liquid from flowing in reverse from the liquid providing opening, or a fluid resistance part that produces large fluid resistance. 7. The inkjet apparatus according to claim 1 or 2, the liquid tank further comprising a displacement member that moves in accordance with change of the capacity of the liquid tank. 8. The inkjet apparatus according to claim 7, wherein an amount of movement of the displacement member is larger than an amount of deformation of the liquid tank that indicates the change of the capacity of the liquid tank. 9. The inkjet apparatus according to claim 7, wherein liquid providing to the liquid tank is controlled based on a position of the displacement member. 10. The inkjet apparatus according to claim 7, wherein the displacement member has a function of changing the capacity of the liquid tank. 11. The inkjet apparatus according to claim 7, wherein the displacement member is made of a material having high thermal conductivity. 12. The inkjet apparatus according to claim 1, the liquid tank further comprising at least two detection electrodes tat are provided at an upper part of an inside of the liquid tank, extend to respective different depths of the liquid tank, and detect a level of liquid in the liquid tank. 13. The inkjet apparatus according to claim 1, the liquid tank further comprising: at least two detection electrodes, provided at an upper part of the inside of the liquid tank, for detecting a level of liquid inside the liquid tank; and an air extraction space that communicates with the air releasing opening, wherein one of the detection electrodes is provided at the air extraction space. 14. The inkjet apparatus of claim 13, wherein the liquid tank further comprising at least one throttling part that is formed by making a part of the air extraction space narrow, and said one of the detection electrodes is provided at the throttling part. 15. The inkjet apparatus according to claim 1, the liquid tank further comprising a valve that is provided at the liquid providing opening and is opened and closed in accordance with a pressure inside the liquid tank. 16. The inkjet apparatus according to claim 1 or 2, the liquid tank further comprising: a second spring member, provided inside the liquid tank, for maintaining a negative pressure inside the liquid tank. 17. The inkjet apparatus according to claim 1, wherein liquid providing to the liquid tank is stopped after the liquid providing opening is filled with the liquid. 18. The inkjet apparatus according to claim 1 or 2, the liquid tank comprising a part that divides an inside of the liquid tank into two rooms and isolates the rooms from each other so that one of the rooms holds one liquid, and the other of the rooms holds another liquid. 19. The inkjet apparatus of claim 1, further comprising a liquid providing device, wherein the liquid providing device provides liquid to an inside of the liquid tank from outside the liquid tank, and supplies liquid to the inkjet head of the printing apparatus from the liquid tank. 20. The inkjet apparatus according to claim 19, wherein the liquid providing device provides liquid to the inside of the liquid tank by using difference in a pressure head. 21. The inkjet apparatus according to claim 19, further comprising a driving member that is provided on a member for fixing the liquid tank thereon and moves so as to change the capacity of the liquid tank. 22. The inkjet apparatus according to claim 21, further comprising a restriction member for restricting an amount of movement of the driving member. 23. The inkjet apparatus according to claim 21, wherein the driving member is provided on the member for fixing the liquid tank such that a gap exists between the liquid tank and the driving member, and the liquid providing device includes a spring member for maintaining the gap. 24. The inkjet apparatus of claim 19, wherein the liquid providing device provides liquid to the inside of the liquid tank by selecting either a state where the inside of the liquid tank is opened to outside air or a state where the inside of the liquid tank is closed from outside air. 25. An inkjet apparatus as described in claim 24, wherein the liquid is ink, and the inkjet apparatus uses the liquid providing device to supply ink to the inkjet head from the liquid tank, and the inkjet printing apparatus further comprises means for wiping a nozzle surface of the inkjet head before the negative pressure is generated inside the liquid tank. 26. The inkjet apparatus of claim 19 wherein the liquid providing device opens or closes an air releasing opening of the liquid tank in accordance with a surrounding temperature. 27. The inkjet apparatus of claim 19 wherein the liquid providing device includes an opening/closing driving member that is provided on a member for fixing the liquid tank and moves so as to open and close the air releasing opening of the liquid tank. 28. The inkjet apparatus according to claim 27, further comprising a restriction member for restricting an amount of movement of the opening/closing driving member that moves so as to open and close the air releasing opening, or further comprising a restriction member for restricting an amount of movement of the opening/closing driving member. 29. The inkjet apparatus according to claim 28, wherein the opening/closing driving member is provided on a member for fixing the liquid tank such that a gap exists between between the liquid tank and the opening/closing driving member, and the liquid providing device further comprises a second spring member for maintaining the gap. 30. An inkjet apparatus as described in claim 19, further comprising an inkjet head, comprising the liquid providing device described in claim 19, wherein the liquid is ink, and the inkjet apparatus uses the liquid providing device to supply ink to the inkjet head from the liquid tank. 31. An inkjet apparatus as described in claim 1, further comprising an inkjet head, wherein the liquid is ink, and the inkjet apparatus supplies ink to the inkjet head from the liquid tank. 32. The inkjet apparatus according to claim 31, further comprising a wiper configured to wire a nozzle surface of the inkjet head before the negative pressure is generated inside the liquid tank. 33. An ink cartridge comprising: the inkjet apparatus described in claim 1, wherein liquid is ink, and the inkjet head is integrally formed on the liquid tank. 34. A pressure adjustment mechanism for an inkjet head device, comprising: a head that ejects ink; a carriage that mounts the head thereon and moves; a subtank that is mounted on the carriage, temporarily holds ink provided from a cartridge, and provides the temporarily held ink to the head; a lever that is moved to adjust a pressure inside the subtank; and diving means for moving the lever selectively to a first position of the lever or a second position of the lever, wherein the subtank includes pressure adjustment means that have air releasing control means and negative pressure control means, the air releasing control means are provided on a side wall of the subtank, enable an inside of the subtank to be opened to outside air, and enable the inside of the subtank to be closed from outside air, and the negative pressure control means generate a negative pressure inside the subtank, the lever acts on the pressure adjustment means at the first position of the lever when the carriage is at a second position of the carriage, and the acting on the pressure adjustment means by the lever is released at the second position of the lever, the driving means include a cam that acts on the lever so as to move the lever, and means for rotating the cam, and when the carriage is at a first position of the carriage where the lever does not act on the pressure adjustment means even if the lever is moved to the first position of the lever, the lever is moved by the driving means to the first position of the lever, and the carriage is moved to the second position of the carriage with the lever being at the first position of the lever to perform air releasing control for the subtank and negative pressure control for the subtank. 35. The pressure adjustment mechanism according to claim 34, further comprising: a plurality of subtanks that are mounted on the carriage, have a substantially same structure as that of said subtank, and hold ink whose types are different from each other; a plurality of levers that have a substantially same structure as that of said lever; and a plurality of pressure adjustment means that are respectively provided on the plurality of subtanks, and have a substantially same structure as that of said pressure adjustment means, wherein each of the plurality of pressure adjustment means receive action applied by one of the plurality of levers. 36. The pressure adjustment mechanism according to claim 35, wherein when a series of movements of one of the plurality of levers successively or simultaneously causes some of the plurality of pressure adjustment means to function, ink is provided to some of the plurality of subtanks corresponding to the some of the plurality of pressure adjustment means. 37. The pressure adjustment mechanism according to claim 34, wherein the pressure adjustment means include an air releasing pin that enables an air releasing opening formed on the subtank to be opened and closed so as to perform the air releasing control, the negative pressure means include a negative pressure pin that moves a part of a wall constituting the subtank so as to control a pressure inside the subtank to be a desired negative pressure, the lever presses the air releasing pin and the negative pressure pin at the first position of the lever when the carriage is at the second position of the carriage, and the lever is separated from the air releasing pin and the negative pressure pin at the second position of the lever, and the air releasing pin is separated from the negative pressure pin in a vertical direction. 38. The pressure adjustment mechanism according to claim 34, wherein when the lever acts on the pressure adjustment means and receives a reaction force that is generated from the pressure adjustment means and that causes a stress acting on the lever in a direction of releasing the acting by the lever on the pressure adjustment means, the stress received by the lever acts on the cam towards a center axis of a rotational shaft of the cam so as to restrain movement of the lever caused by the stress. 39. An inkjet printer comprising the pressure adjustment mechanism described in claim 34, wherein the inkjet printer provides ink to an inside of the subtank while the inkjet printer uses the pressure adjustment mechanism so as to adjust a pressure in the subtank. 40. An inkjet apparatus, comprising: an inkjet head that ejects liquid; and a liquid tank that holds liquid supplied from a cartridge and that supplies liquid to the inkjet head, the liquid tank including: a flexible film configured to close an opening of a case forming the liquid tank; a spring member, provided inside the liquid tank, configured to press the flexible film in a direction towards the outside of the liquid tank to generate a negative pressure from a state having no negative pressure in the liquid tank; a liquid providing opening configured to receive liquid from the cartridge into the liquid tank; and an air releasing opening that is opened and closed so that an inside of the liquid tank is opened and closed to outside air. 41. The inkjet apparatus according to claim 40, wherein the liquid tank further comprises a displacement member that moves in accordance with deformation of the flexible film that indicates change of the capacity of the liquid tank. 42. The inkjet apparatus according to claim 41, wherein an amount of movement of the displacement member is larger than an amount of deformation of the flexible film. 43. The inkjet apparatus according to claim 41, wherein liquid providing to the liquid tank is controlled based on a position of the displacement member. 44. The inkjet apparatus according to claim 41, further comprising a displacement detection part configured to detect the deformation of the flexible film by detecting the deformation of the displacement member. 45. The inkjet apparatus according to claim 41, wherein the displacement member rotates on a corner of the liquid tank in accordance with the deformation of the flexible film. 46. The inkjet apparatus according to claim 40, wherein the liquid tank further comprises a detection electrode that is provided at an upper part of an inside of the liquid tank configured to detect a level of liquid in the liquid tank. 47. The inkjet apparatus according to claim 40, wherein the liquid tank further comprises a valve that is provided at the liquid providing opening and is opened and closed in accordance with a pressure inside the liquid tank. 48. The inkjet apparatus according to claim 40, further comprising a liquid providing device that provides liquid to an inside of the liquid tank from outside the liquid tank, and that supplies liquid to the inkjet head of the printing apparatus from the liquid tank. 49. The inkjet apparatus according to claim 48, wherein the liquid providing device provides liquid to the inside of the liquid tank by using difference in a pressure head. 50. The inkjet apparatus according to claim 48, wherein the liquid providing device provides liquid to the inside of the liquid tank by selecting either a state where the inside of the liquid tank is opened to outside air or a state where the inside of the liquid tank is closed from outside air. 51. The inkjet apparatus according to claim 48, wherein the liquid providing device opens or closes an air releasing opening of the liquid tank in accordance with a surrounding temperature. 52. The inkjet apparatus according to claim 40, further comprising a wiper configured to wipe a nozzle surface of the inkjet head before the negative pressure is generated inside the liquid tank.