Ink jet recording apparatus, method of replenishing ink to subtank in the apparatus, and method of checking the replenished amount of ink

• US 20020024543A1
• Filed: 07/05/2001
• Published: 02/28/2002
• Est. Priority Date: 11/05/1999
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kobayashi, Atsushi, Kumagai, Toshio, Usui, Minoru, Tamura, Noboru, Kimura, Hitotoshi, Mano, Takashi, Tojyo, Hiroaki, Aruga, Yoshiharu, Suzuki, Kazunaga
• Granted Patent: US 6,796,627 B2
• Time in Patent Office: Days
• US Class Current: 347/7
• CPC Class Codes: B41J 2/17509 Whilst mounted in the printer
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17523 Ink connection
• CPC Class Codes: B41J 2/17526 Electrical contacts to the cartridge
• CPC Class Codes: B41J 2/17553 Outer structure
• CPC Class Codes: B41J 2/17566 Ink level or ink residue control
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/17573 using optical means for ink level indication
• CPC Class Codes: B41J 2002/17576 using a floater for ink level indication

Abstract

In an ink jet recording apparatus, a recording head is mounted on a carriage which reciprocately moves in a widthwise direction of recording paper. A subtank is mounted on the carriage for supplying ink. A main tank stores ink which is replenished to the subtank. An ink amount detector detects an amount of ink stored in the subtank. A replenishment controller controls replenishment of ink stored in the main tank to the subtank, in accordance with the ink amount detected by the ink amount detector.

Claims

1. An ink jet recording apparatus comprising:

a recording head, mounted on a carriage which reciprocately moves in a widthwise direction of recording paper;

a subtank, mounted on the carriage for supplying ink;

a main tank, storing ink which is replenished to the subtank;

an ink amount detector, which detects an amount of ink stored in the subtank; and

a replenishment controller, which controls replenishment of ink stored in the main tank to the subtank, in accordance with the ink amount detected by the ink amount detector.

2. The recording apparatus as set forth in claim 1, wherein the replenishment controller is provided in a replenishment passage which connects the main tank and the subtank.

3. The recording apparatus as set forth in claim 2, further comprising a compressor, which applies pressure to the main tank for replenishing ink stored therein to the subtank,

wherein the replenishment controller includes an ink replenishing valve which is opened or closed by a control signal generated by the ink amount detector.

4. The recording apparatus as set forth in claim 1, wherein the replenishment controller includes a pump, which is operated in accordance with the ink amount detected by the ink amount detector, for replenishing ink stored in the main tank to the subtank.

5. The recording apparatus as set forth in claim 1, wherein the replenishment controller includes a pump for replenishing ink stored in the main tank to the subtank, and a pump controller which controls the pump in accordance with a drive signal sent to the recording head.

6. The recording apparatus as set forth in claim 1, wherein the ink amount detector includes a float member floating on ink stored in the subtank, and an output generator which generates an electrical output in accordance with a floating position of the float member, which changes according to the stored ink amount.

7. The recording apparatus as set forth in claim 1, wherein the ink amount detector detects the ink amount stored in the subtank by calculating an amount of ink ejected or sucked from the recording head.

8. The recording apparatus as set forth in claim 6, wherein the output generator includes a permanent magnet disposed on the float member, and a magnetoelectric element which generates the electrical output in accordance with a magnetic flux density, which changes according to the position of the float member.

9. The recording apparatus as set forth in claim 8, wherein the magnetoelectric element is a hall element.

10. The recording apparatus as set forth in claim 9, wherein a plurality of magnetoelectric elements are arranged so as to generate output signals having different phases in accordance with a movement of the permanent magnet provided with the float member.

11. The recording apparatus as set forth in claim 10, wherein at least two magnetoelectric elements are arranged above and below a predetermined level of ink such that both elements are able to detect the magnetic flux generated from the permanent magnet so that at least three ink levels are recognized.

12. The recording apparatus as set forth in claim 11, wherein the magnetoelectric elements are arranged such that the following states are recognized by the output signals therefrom:

a first state indicating an ink end state;

a second state indicating the ink replenishment needs starting;

a third state indicating the ink replenishment needs terminating; and

a fourth state indicating an ink overflow state.

13. The recording apparatus as set forth in claim 2, wherein the replenishment controller blocks ink communication when an operation power of the apparatus is turned off.

14. The recording apparatus as set forth in claim 3, wherein the ink replenishing valve includes a diaphragm valve, a slide shaft provided in a substantially center portion of the diaphragm valve, and an actuator which moves the slide shaft in an axial direction thereof to open or close the diaphragm valve.

15. The recording apparatus as set forth in claim 14, wherein the replenishing valve includes a case which accommodates the diaphragm valve therein, so that an aperture formed on the case is opened or closed by the diaphragm valve.

16. The recording apparatus as set forth in claim 14, wherein the center portion of the diaphragm valve is horizontally movable.

17. The recording apparatus as set forth in claim 16, wherein a tube for replenishing ink to the subtank is vertically connected to the case;

and

wherein a first ink supply passage connecting the main tank and the diaphragm valve and a second ink supply passage connecting the diaphragm valve and the ink replenishing tube are arranged so as to extend perpendicularly to each other.

18. The recording apparatus as set forth in claim 14, wherein the actuator is an electromagnetic plunger.

19. The recording apparatus as set forth in claim 18, wherein the ink replenishing valve includes a pivotal lever member;

and

wherein a driving force of the electromagnetic plunger is acted on one end of the lever member so that the driving force is transmitted to the slide shaft via the other end of the lever member.

20. The recording apparatus as set forth in claim 18, wherein the diaphragm valve is opened when the electromagnetic plunger is activated, and is closed when the electromagnetic plunger is not activated.

21. The recording apparatus as set forth in claim 1, wherein the ink amount detector includes an ink end detector which determines that the main tank is in an ink end state when an ink amount replenished to the subtank is less than a predetermined level which indicates an ink full state, even if a time period spent for the ink replenishment is a predetermined time period or more.

22. The recording apparatus as set forth in claim 3, further comprising a timer, which starts counting a time period when the ink replenishing valve is opened;

wherein the ink amount detector includes a consumed ink amount calculator, which calculates an ink amount consumed in the subtank;

wherein the ink replenishing valve is opened when the consumed ink amount calculated by the consumed ink amount calculator is a predetermined value or more;

wherein the ink replenishing valve is closed when the ink amount detector detects that the replenished ink amount in the subtank is a predetermined level or more, which indicates an ink full state; and

wherein the ink amount detector includes an ink end detector which determines that the main tank is in an ink end state when the ink amount detector does not detect the ink full state, even if the timer counts a predetermined time period.

23. The recording apparatus as set forth in claim 22, the ink amount detector includes a residual ink amount detector, which detects an ink amount remaining in the main tank,

wherein the determination of the ink end detector is made effective when the residual ink detector detects that the residual ink amount is a predetermined amount or less.

24. The recording apparatus as set forth in claim 23, wherein the consumed ink amount calculator and the residual ink amount detector respectively calculate the consumed ink amount and the residual ink amount by multiplying coefficients which are respectively provided in association with ink ejection for printing, ink ejection for flushing, and ink suction for cleaning.

25. The recording apparatus as set forth in claim 22, wherein the ink amount detector includes a float member floating on ink stored in the subtank, an output generator which generates an electrical output in accordance with a floating position of the float member, which changes according to the stored ink amount.

26. The recording apparatus as set forth in claim 3, wherein the replenishment controller forcibly closes the ink replenishment valve when a predetermined time period is elapsed after the ink replenishment valve is opened.

27. The recording apparatus as set forth in claim 26, wherein a recovery operation is performed when the ink amount detector detects an ink overflow state in which the ink amount stored in the subtank is a predetermined value or more.

28. The recording apparatus as set forth in claim 26, wherein the ink amount detector rechecks the ink overflow state after the recovery operation is completed.

29. The recording apparatus as set forth in claim 28, wherein a printable condition of the apparatus is continued when the ink overflow state is not detected by the rechecking.

30. The recording apparatus as set forth in claim 28, wherein an error condition of the apparatus is recognized when the ink overflow state is detected by the rechecking.

31. The recording apparatus as set forth in claim 27, wherein the recovery operation is either one of an operation for discharging ink from the recording head or an operation for consuming ink.

32. The recording apparatus as set forth in claim 31, wherein the discharging operation is performed by sealing a nozzle formation face of the recording head with a capping member and applying therein negative pressure generated by a suction pump.

33. The recording apparatus as set forth in claim 32, wherein the discharging operation is repeatedly performed;

and

wherein the ink overflow state is checked every time when the discharging operation is performed.

34. The recording apparatus as set forth in claim 33, wherein an error condition is recognized when the ink overflow state is detected even after the discharging operation is repeated at a predetermined number of times.

35. The recording apparatus as set forth in claim 31, wherein the consuming operation is performed by executing a predetermined amount of printing.

36. The recording apparatus as set forth in claim 35, wherein the printing is continued until printing for a subject page is finished.

37. The recording apparatus as set forth in claim 28, wherein an error massage is displayed on a display when the ink overflow state is detected by the rechecking.

38. The recording apparatus as set forth in claim 28, wherein an alarm massage is displayed on a display when the ink overflow state is not detected by the rechecking.

39. The recording apparatus as set forth in claim 1, wherein ink stored in the main tank is replenished to the subtank when the ink amount detector detects that the ink amount stored in the subtank is a predetermined amount or less;

and

wherein the ink amount detector detects an ink low level which is determined as an ink amount capable of remaining in the subtank even after ink consumption by a single cleaning operation.

40. The recording apparatus as set forth in claim 39, wherein the predetermined amount detected by the ink amount detector is an ink amount consumed by a single cleaning operation or more.

41. The recording apparatus as set forth in claim 39, wherein the predetermined amount detected by the ink amount detector is an ink amount, which is defined by subtracting an ink amount replenished during the cleaning operation from an ink amount consumed by a single cleaning operation, or more.

42. The recording apparatus as set forth in claim 1, further comprising:

a timer, which counts a time period in which the apparatus is not operated;

a discharger, which discharges ink stored in the subtank; and

a refilling controller, which controls the discharger and the replenishment controller such that ink stored in the subtank is discharged while replenishing ink stored in the main tank to the subtank, when the apparatus is recovered from the non-operating state and a time period counted by the timer reaches a predetermined time period.

43. The recording apparatus as set forth in claim 42, further comprising a residual ink amount sensor, which detects an ink amount remaining in the subtank which is in the non-operating state,

wherein the predetermined time period is made shorter as less amount of ink is detected by the residual ink sensor.

44. The recording apparatus as set forth in claim 42, wherein a part of ink left in the subtank is discharged when the apparatus is recovered from the non-operating state.

45. The recording apparatus as set forth in claim 1, wherein the ink amount detector includes:

an electrically rewritable memory, provided with the main tank;

a consumed ink amount calculator, which provides information regarding an ink amount consumed in the subtank, which is written in the memory;

a residual ink amount detector, which provides information regarding an ink amount remaining in the main tank, which is written in the memory; and

an ink end detector which provides information regarding whether the main tank is in an ink end state, which is written in the memory.

46. The recording apparatus as set forth in claim 45, wherein the consumed ink amount information and the residual ink amount information are calculated by respectively multiplying the consumed ink amount and the residual ink amount with coefficients which are respectively provided in association with ink ejection for printing, ink ejection for flushing, and ink suction for cleaning.

47. The recording apparatus as set forth in claim 45, wherein the information provided by the ink end detector is associated with an ink end flag provided in the memory.

48. The recording apparatus as set forth in claim 45, wherein the consumed ink amount information and the residual ink amount information are converted into first numeral values which indicate the ink end state of the main tank, when the ink end detector provides information indicating that the main tank is in the ink end state.

49. The recording apparatus as set forth in claim 48, wherein the consumed ink amount information and the residual ink amount information are provided as numeral values, which are incremented or decremented;

wherein the increment and the decrement of the numeral values are stopped at second numeral values which is in the vicinity of the first values; and

wherein the second values are converted into the first values when the ink end detector provides information indicating that the main tank is in the ink end state.

50. The recording apparatus as set forth in claim 1, wherein the ink amount detector includes a physical detector, which detects that the main tank is in an ink end state.

51. The recording apparatus as set forth in claim 50, wherein the physical detector includes an optical sensor.

52. The recording apparatus as set forth in claim 50, wherein the physical detector includes a mechanical switch.

63. The recording apparatus as set forth in claim 50, wherein the physical detector includes a pair of electrode terminals.

53. A method of replenishing ink stored in a main tank to a subtank mounted on a carriage reciprocately moving in a widthwise direction of recording paper, together with a recording head, which are incorporated in an ink jet recording apparatus, the method comprising the steps of:

applying pressure generated by a compressor to the main tank;

operating an ink replenishing valve provided in a replenishment passage which connects the main tank and the subtank, so as to be opened and closed repeatedly in accordance with an amount of ink stored in the subtank.

54. The replenishing method as set forth in claim 53, wherein the pressure applying step includes the steps of operating the compressor so as to be driven and stopped repeatedly in accordance with a pressure state in an air passage connecting the compressor and the main tank.

55. The replenishing method as set forth in claim 53, wherein the ink replenishing valve is opened when it is detected that the ink amount stored in the subtank is less than a first predetermined volume, and closed when it is detected that a replenished ink amount in the subtank reaches a second predetermined volume;

and

wherein the ink replenishing valve is forcibly closed when a predetermined time period is elapsed after the ink replenishing valve is opened.

56. The replenishing method as set forth in claim 55, further comprising the step of displaying an error message, when the ink replenishing valve is forcibly closed.

59. The checking method as set forth in claim 57, wherein the discharging step includes the steps of:

sealing a nozzle formation face of the recording head with a capping member; and

applying therein negative pressure generated by a suction pump.

60. The checking method as set forth in claim 58, wherein the discharging step includes the steps of:

sealing a nozzle formation face of the recording head with a capping member; and

applying therein negative pressure generated by a suction pump.

57. A method of checking replenishment of ink stored in a main tank to a subtank mounted on a carriage reciprocately moving in a widthwise direction of recording paper, together with a recording head, which are incorporated in an ink jet recording apparatus, the method comprising the steps of:

detecting an ink amount replenished to the subtank;

discharging ink from the recording head when it is detected an ink overflow state in which the replenished ink amount detected by the detecting step exceeds a predetermined value;

checking whether the subtank is in the ink overflow state by detecting again an ink amount replenished to the subtank, after the discharging step;

continuing a printable condition of the apparatus when the ink overflow state is not detected by the checking step; and

determining an error condition of the apparatus when the ink overflow state is detected by the checking step.

58. A method of checking replenishment of ink stored in a main tank to a subtank mounted on a carriage reciprocately moving in a widthwise direction of recording paper, together with a recording head, which are incorporated in an ink jet recording apparatus, the method comprising the steps of:

detecting an ink amount replenished to the subtank;

discharging ink from the recording head when it is detected an ink overflow state in which the replenished ink amount detected by the detecting step exceeds a predetermined value, while incrementing a number of which the ink overflow state is detected;

repeating the discharging step and the incrementing step while comparing the detected number with a predetermined number; and

detecting an error condition of the apparatus when the detected number reaches the predetermined number.

61. A method of checking replenishment of ink stored in a main tank to a subtank mounted on a carriage reciprocately moving in a widthwise direction of recording paper, together with a recording head, which are incorporated in an ink jet recording apparatus, the method comprising the steps of:

detecting an ink amount replenished to the subtank;

performing a predetermined amount of printing when it is detected an ink overflow state in which the replenished ink amount detected by the detecting step exceeds a predetermined value;

checking whether the subtank is in the ink overflow state by detecting again an ink amount replenished to the subtank, after the printing step;

continuing a printable state of the apparatus when the ink overflow state is not detected by the checking step; and

determining an error state of the apparatus when the ink overflow state is detected by the checking step.

62. The checking method as set forth in claim 61, wherein the printing step is continued until printing for a subject page is finished.