Ink jet head driving device

Patent metadata

Field	Value
Publication number	US-9302475-B2
Application number	US-201313973116-A
Country	US
Kind code	B2
Filing date	Aug 22, 2013
Priority date	Aug 27, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A driving device of an ink jet head including a plurality of ejection channels, including a plurality of driving waveform generation portions that are provided which respectively correspond to the plurality of ejection channels, a random number generation portion that generates a random number, and a connection portion. The driving waveform generation portions receive printing data and correction data, generate a driving signal of the ejection channels on the basis of the received printing data, correct a waveform of the driving signal by using the received correction data, and then output the corrected waveform to the correction data and to the corresponding ejection channels. The connection portion connects the random number generation portion of the driving waveform generation portions such that a random number is supplied to each of the driving waveform generation portions as correction data having a value independent for each of the driving waveform generation portions.

First claim

What is claimed is:

1. A driving device of an ink jet head including a plurality of ejection channels, comprising:
a plurality of driving waveform generation portions that are provided so as to respectively correspond to the plurality of ejection channels, receive printing data and correction data, generate a driving signal of the ejection channels on the basis of the received printing data, correct a waveform of the driving signal by using the received correction data, and output the corrected waveform to the corresponding ejection channels;
a random number generation portion that generates a pseudorandom number formed by a plurality of bits; and
a connection portion that connects the random number generation portion to the respective driving waveform generation portions, wherein the connection portion connects the random number generation portion to the respective driving waveform generation portions such that the same bit of the pseudorandom number is supplied to bits having different weights of the correction data to be input to at least two driving waveform generation portions.

2. The device according to claim 1 ,
wherein the connection portion connects the random number generation portion to the respective driving waveform generation portions with random manner.

3. The device according to claim 1 , wherein the random number generation portion generates a pseudorandom number formed by a plurality of bits smaller than a total number of bits of correction data to be input to the respective driving waveform generation portions.

4. The device according to claim 1 ,
wherein an ink jet head driving device in which a plurality of ejection channels included in an ink jet head are divided into two or more groups, and the ejection channels included in the same group are driven together,
wherein a plurality of driving waveform generation portions are provided so as to respectively correspond to a plurality of ejection channels included in any one group among the plurality of ejection channels, correct a waveform of the driving signal by using the received correction data, and then output the corrected waveform to corresponding ejection channels,
further comprising:
a pseudorandom number updating portion that updates a pseudorandom number generated by the random number generation portion each time the group of the ejection channels which are driven together is changed.

5. The device according to claim 1 , further comprising:
a plurality of adding portions that are provided so as to respectively correspond to the driving waveform generation portions, and add second correction data related to the ejection channels to correction data from the connection portion,
wherein correction data additional values obtained through the addition by the adding portions are respectively supplied to the corresponding driving waveform generation portions as correction data.

6. A driving device of an ink jet head including a plurality of ejection channels, comprising:
a plurality of driving waveform generation portions that are provided so as to respectively correspond to the plurality of ejection channels, receive printing data and correction data, generate a driving signal of the ejection channels on the basis of the received printing data, correct a waveform of the driving signal by using the received correction data, and then output the corrected waveform to the corresponding ejection channels;
a random number generation portion that generates a pseudorandom number formed by a plurality of bits; and
a connection portion that connects the random number generation portion to the respective driving waveform generation portions,
wherein the connection portion connects the random number generation portion to the respective driving waveform generation portions such that the same bit of the pseudorandom number does not overlap bits having the same weight of the correction data to be input to the respective driving waveform generation portions.

7. The device according to claim 6 ,
wherein an ink jet head driving device in which a plurality of ejection channels included in an ink jet head are divided into two or more groups, and the ejection channels included in the same group are driven together,
wherein a plurality of driving waveform generation portions are provided so as to respectively correspond to a plurality of ejection channels included in any one group among the plurality of ejection channels, correct a waveform of the driving signal by using the received correction data, and then output the corrected waveform to corresponding ejection channels,
further comprising:
a pseudorandom number updating portion that updates a pseudorandom number generated by the random number generation portion each time the group of the ejection channels which are driven together is changed.

8. The device according to claim 6 , further comprising:
a plurality of adding portions that are provided so as to respectively correspond to the driving waveform generation portions, and add second correction data related to the ejection channels to correction data from the connection portion,
wherein correction data additional values obtained through the addition by the adding portions are respectively supplied to the corresponding driving waveform generation portions as correction data.

9. An ink jet recording apparatus comprising:
a plurality of ink jet heads each having a plurality of ejection channels;
a printing controller; and
cable wires connecting between the ink jet heads and the printing controller, wherein the ink jet heads further comprising:
driving waveform generation portions giving driving waveform to the respective ejection channels,
a random number generation portion that generates a pseudorandom number formed by a plurality of bits,
an initializing portion which initializes the random number generation portion with an initial value,
a data reception portion which receive printing data from the printing controller via the cable wires;
a connection portion that connects the random number generation portion to the respective driving waveform generation portions;

wherein the driving waveform generation portions change the driving waveform based on the received printing data and the pseudorandom number, and the connection portion connects the random number generation portion to the respective driving waveform generation portions such that the same bit of the pseudorandom number is supplied to bits having different weights of the correction data to be input to at least two driving waveform generation portions.

10. The device according to claim 9 , wherein the initial values of at least two ink jet heads are different each other.

11. An ink jet recording apparatus according to claim 10 , wherein the plurality of the ink jet heads are arranged in the direction of the nozzle arrangement of each ink jet heads, and the difference of the initial values of each ink jet heads prevents a cyclic regularity in a print density having cycle length of a nozzle width of the ink let heads.

12. An ink jet recording apparatus according to claim 10 ,
wherein the plurality of the ink jet heads are arranged perpendicular to the direction of the nozzle arrangement of each ink jet heads,
wherein the difference of the initial values of each ink jet heads prevents an emphasis in a print density unevenness caused by the pseudorandom number.

13. An ink jet recording apparatus according to claim 10 ,
wherein the plurality of the ink jet heads are arranged perpendicular to the direction of the nozzle arrangement of each ink jet heads,
wherein at least 2 of the ink jet heads ejects differe

Assignees

• Toshiba Tec Kk

Inventors

• Nitta Noboru
• Hiyoshi Teruyuki
• Kimura Mamoru
• Yoshimaru Tomohisa

Classifications

• B41J2/04541

  Specific driving circuit · CPC title

• B41J2/04588 Primary

  using a specific waveform · CPC title

• B41J2/04508

  aiming at correcting other parameters · CPC title

• B41J2/0451

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

• B41J2/04573

  Timing; Delays · CPC title