Method of testing print head, printing method, device for testing print head, and printer

Patent metadata

Field	Value
Publication number	US-9688066-B2
Application number	US-201615287371-A
Country	US
Kind code	B2
Filing date	Oct 6, 2016
Priority date	May 20, 2014
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A plurality of recording elements included in a printed head are grouped into a plurality of groups, a test order is set in units of groups, and a test of the recording elements is periodically performed in units of groups in the set test order. In a case where an abnormality is detected in the recording element as a result of the test, the recording element in which an abnormality is detected is recognized as a retest target, an order of tests is changed through interruption, and a retest of a group including the recording element recognized as a retest target is performed. In a case where an abnormality is detected again in the recording element that is a retest target as a result of the retest, the recording element that is a retest target is recognized as an abnormal recording element.

First claim

What is claimed is:

1. A method of testing a print head comprising a plurality of recording elements, the method comprising:
grouping the plurality of recording elements into a plurality of groups, and setting a test order of the plurality of recording elements in units of groups;
periodically performing a test of the plurality of recording elements in units of groups in the set test order;
recognizing the recording element in which an abnormality is detected, as a retest target, in a case where an abnormality is detected in at least one recording element among the plurality of recording elements in the test;
performing a retest of at least the recording element that is a retest target through interruption before a test to be performed in a test order before a change by changing the test order in a case where the recording element that is a retest target is recognized; and
recognizing the recording element that is a retest target as an abnormal recording element in a case where an abnormality is detected again in the recording element that is a retest target as a result of the retest.

2. The method of testing a print head according to claim 1 , further comprising:
recognizing the recording element that is a retest target, as the retest target, in a case where an abnormality is not detected again in the recording element that is a retest target as a result of the retest, and performing the retest up to a preset number of times through interruption.

3. The method of testing a print head according to claim 1 ,
wherein the print head is an ink jet type of print head,
the recording element is a nozzle included in the print head, and
the abnormal recording element is recognized as an abnormal nozzle.

4. The method of testing a print head according to claim 3 ,
wherein the test and the retest are performed by discharging ink from the nozzle to a medium and reading an image printed on the medium.

5. The method of testing a print head according to claim 3 ,
wherein the nozzles are grouped for each color of the ink discharged from the nozzle.

6. The method of testing a print head according to claim 5 ,
wherein the print head incorporated into a printer is tested during execution of a printing job.

7. The method of testing a print head according to claim 6 ,
wherein the print head is a line head having a width corresponding to a width of a printing medium,
the printer prints an image on the medium with a margin in a single pass, and
the print head is tested during execution of a printing job by discharging ink to a margin region of the medium.

8. A printing method, comprising:
testing a print head using the method of testing a print head according to claim 3 ; and
setting a recognized abnormal nozzle to non-discharge in a case where the abnormal nozzle is recognized, performing non-discharge correction, and printing an image on a medium.

9. A device for testing a print head comprising a plurality of recording elements, the device comprising:
a test order setting unit that groups the plurality of recording elements into a plurality of groups, and sets a test order of the plurality of recording elements in units of groups;
a test unit that periodically performs a test of the plurality of recording elements in units of groups in the test order set by the test order setting unit;
a retest target recognition unit that recognizes the recording element in which an abnormality is detected, as a retest target, in a case where an abnormality is detected in at least one recording element among the plurality of recording elements by the test unit;
a retest unit that performs a retest of at least the recording element that is a retest target through interruption before a test to be performed in a test order before a change by changing the test order in a case where the recording element that is a retest target is recognized; and
an abnormal recording element recognition unit that recognizes the recording element that is a retest target as an abnormal recording element in a case where an abnormality is detected again in the recording element that is a retest target as a result of the retest in the retest unit.

10. The device for testing a print head according to claim 9 , further comprising:
a second retest target recognition unit that recognizes the recording element that is a retest target, as the retest target, in a case where an abnormality is not detected again in the recording element that is a retest target again as a result of the retest in the retest unit,
wherein the retest unit performs the retest up to the preset number of times through interruption.

11. The device for testing a print head according to claim 9 ,
wherein the print head is an ink jet type of print head,
the recording element is a nozzle comprised in the print head, and
the abnormal recording element recognition unit is an abnormal nozzle recognition unit that recognizes the abnormal recording element as an abnormal nozzle.

12. The device for testing a print head according to claim 11 ,
wherein the test unit causes ink to be discharged from the nozzle to a medium, and reads an image printed on the medium to test the nozzle, and
the retest unit causes ink to be discharged from the nozzle to a medium, and reads an image printed on the medium to retest the nozzle.

13. The device for testing a print head according to claim 11 ,
wherein the test order setting unit groups the nozzles for each color of ink discharged from the nozzle, and sets the test order of the nozzles in units of the groups.

14. A printer for printing an image on a medium using an inkjet type of print head comprising a plurality of nozzles, the printer comprising:
a device for testing a print head according to claim 11 ,
wherein the print head is tested during execution of a printing job.

15. The printer according to claim 14 ,
wherein the print head is a line head having a width corresponding to a width of a printing medium,
the printer prints an image on the medium with a margin in a single pass, and
the print head is tested during execution of a printing job by discharging ink to a margin region of the medium.

16. The printer according to claim 14 , further comprising:
a non-discharge correction unit that sets the recognized abnormal nozzle to non-discharge and performs non-discharge correction in a case where the abnormal nozzle recognition unit recognizes the abnormal nozzle.

Assignees

• Fujifilm Corp

Inventors

• Yamanobe Jun
• Kyoso Tadashi
• Sumi Katsuto

Classifications

• B41J2/2146

  for line print heads · CPC title

• B41J2/04558

  detecting presence or properties of a dot on paper · CPC title

• B41J2/2142 Primary

  Detection of malfunctioning nozzles (generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045, B41J2/05; jet deflection sensors B41J2/125; for cleaning purposes B41J2/16579) · CPC title

• B41J2/0451 Primary

  for detecting failure, e.g. clogging, malfunctioning actuator · CPC title

• B41J2025/008

  comprising a plurality of print heads placed around a drum · CPC title