Ink-jet printer

• US 6,334,658 B1
• Filed: 11/05/1998
• Issued: 01/01/2002
• Est. Priority Date: 11/06/1997
• Status: Expired due to Term

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: Suzuki, Shogo
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): DUDDING, ALFRED E
• Application Number:
  US09/186,289
• Time in Patent Office: 1,153 Days
• Field of Search: 347/7, 347/19
• US Class Current: 347/7
• CPC Class Codes: B41J 2/1752 Mounting within the printer
• CPC Class Codes: B41J 2/17566 Ink level or ink residue control
• CPC Class Codes: B41J 2/17593 Supplying ink in a solid state
• CPC Class Codes: B41J 2002/17569 based on the amount printed or to be printed

Abstract

The invention provides an ink-jet printer for enabling precise and automatic detection of an ink jetting failure in an ink-jet head. When ink in an ink tank decreases up to an ink supplement level, a fixed quantity of ink in the shape of a pellet is supplied the number of jetted ink droplets corresponding to print data and the like, are counted, and the printing operation is executed. When ink again decreases up to quantity for ink to be supplemented, the calculated ink consumed quantity calculated based upon the counted number of jetted ink droplets and the quantity of ink in the ink pellets, are compared. If both are not equal, it is determined that an ink jetting failure has occurred. Then, after a maintenance operation is executed, ink is again supplied and the printing operation is continued.

Claims

1. An ink-jet printer, comprising:

an ink tank that stores ink;

an ink-jet head that jets ink in the ink tank onto a recorded medium according to a driving signal;

a detector that detects the consumed quantity of ink in the ink tank;

a calculation unit that calculates the consumed quantity of ink in the ink tank according to the driving signal; and

a determination unit that, upon consumption of a predetermined amount of ink as determined by the detector, compares the ink consumed quantity calculated by the calculation unit and the ink consumed quantity detected by the detector, the determination unit determining that an ink jetting failure has occurred in the ink-jet head if a difference between the ink consumed quantity calculated by the calculation unit and the ink consumed quantity detected by the detector is greater than a predetermined quantity.

2. The ink-jet printer according to claim 1, further comprising:

a maintenance unit that cleans the ink jetted path of the ink-jet head; and

a maintenance controller that executes cleaning by the maintenance unit when the determination unit determines that an ink jetting failure has occurred.

3. The ink-jet printer according to claim 1, wherein the detector detects at least a decrease of ink in the ink tank.

4. The ink-jet printer according to claim 3, wherein the detector detects when ink is required to be supplemented.

5. The ink-jet printer according to claim 1, wherein the detector detects at least that ink in the ink tank decreases up to a first reference value and that the ink decreases up to a second reference value different from the first reference value.

6. The ink-jet printer according to claim 5, wherein the calculation unit calculates the consumed quantity of ink after the detector detects that ink in the ink tank has decreased to the first reference value.

7. The ink-jet printer according to claim 1, wherein the calculation unit comprises a setting unit that sets a number of jetted ink droplets before ink is required to be supplemented.

8. The inkjet printer according to claim 7, wherein the determination unit determines that an ink jetting failure has occurred in the ink-jet head based upon the number of jetted ink droplets set by the setting unit.

9. The ink-jet printer according to claim 1, further comprising:

a ink supply unit that supplies a predetermined quantity of ink into the ink tank; and

a supply controller that instructs the ink supply unit to supply ink when the determination unit determines that ink is required to be supplemented.

10. A method for operating an ink-jet printer, comprising:

jetting ink from an ink tank that stores ink onto a recorded medium according to a driving signal;

detecting the consumed quantity of ink in the ink tank;

calculating the consumed quantity of ink in the ink tank according to the driving signal;

comparing the ink consumed quantity calculated in the calculating step and the ink consumed quantity detected in the detecting step; and

upon consumption of a predetermined quantity of ink, determining that an ink jetting failure has occurred in the ink-jet head if a difference between the ink consumed quantity calculated in the calculating step and the ink consumed quantity detected in the detecting step is greater than a predetermined quantity.

11. The method according to claim 10, further comprising:

cleaning the ink jetted path of the inkjet head; and

controlling execution of cleaning when the determining step determines that an ink jetting failure has occurred.

12. The method according to claim 10, wherein the detecting step detects at least a decrease of ink in the ink tank.

13. The method according to claim 12, wherein the detecting step detects when ink is required to be supplemented.

14. The method according to claim 10, wherein the detecting step detects at least that ink in the ink tank decreases up to a first reference value and that the ink decreases up to a second reference value different from the first reference value.

15. The method according to claim 14, wherein the consumed quantity of ink is calculated in the calculation step after the detection step detects that ink in the ink tank has decreased to the first reference value.

16. The method according to claim 10, further comprising setting a number of jetted ink droplets before ink is required to be supplemented.

17. The method according to claim 16, wherein the determining step determines that an ink jetting failure has occurred in the ink-jet head based upon the number of jetted ink droplets set in the setting step.

18. The method according to claim 10, further comprising:

supplying a predetermined quantity of ink into the ink tank; and

executing the supplying step when the determining step determines that ink is required to be supplemented.

19. A storage medium for storing programs for operating an ink-jet printer, comprising:

a program for jetting ink from an ink tank that stores ink onto a recorded medium according to a driving signal;

a program for detecting the consumed quantity of ink in the ink tank;

a program for calculating the consumed quantity of ink in the ink tank according to the driving signal;

a program for, upon consumption of a predetermined quantity of ink, comparing the ink consumed quantity calculated in the calculating program and the ink consumed quantity detected in the detecting program; and

a program for determining that an ink jetting failure has occurred in the ink-jet head if a difference between the ink consumed quantity calculated in the calculating program and the ink consumed quantity detected in the detecting program is greater than a predetermined quantity.