Liquid discharge device, liquid discharge control method, and recording medium

Patent metadata

Field	Value
Publication number	US-10065423-B2
Application number	US-201615368897-A
Country	US
Kind code	B2
Filing date	Dec 5, 2016
Priority date	Dec 17, 2015
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

A liquid discharge device includes: a liquid discharge head; a nozzle array disposed on the head in a conveyance direction; a movement driver that moves the head to discharge liquid from the nozzle array in a direction perpendicular to the conveyance direction in a reciprocating manner; a discharge driver that causes the head to discharge the liquid; a conveyor that conveys an object; and a controller that acquires an amount of conveyance of the object by the conveyor over a period during which the head moves from a predetermined position to a position where the head is to discharge the liquid to a target pixel, and determines, on which reciprocating travelling of the head to discharge the liquid and from which nozzle in the nozzle array to discharge the liquid, based on the amount of conveyance.

First claim

The invention claimed is:

1. A liquid discharge device, comprising:
a liquid discharge head;
a nozzle array on the liquid discharge head in a conveyance direction in which an object is conveyed;
a movement driver configured to move the liquid discharge head to discharge a liquid from the nozzle array in a direction perpendicular to the conveyance direction in a reciprocating manner;
a discharge driver configured to instruct the liquid discharge head to discharge the liquid while the movement driver moves the liquid discharge head;
a conveyor configured to convey the object while the movement driver moves the liquid discharge head; and
a controller configured to control discharge of the liquid to a target pixel by,
setting a moving speed of the liquid discharge head by the movement driver and a conveyance speed of the object by the conveyor such that the moving speed remains proportional to the conveyance speed in response to either an acceleration and a deceleration the liquid discharge head, and
determining on which reciprocating travelling of the liquid discharge head to discharge the liquid to the target pixel, and from which nozzle in the nozzle array to discharge the liquid to the target pixel, based on an amount of conveyance of the object by the conveyor over a period during which the liquid discharge head moves from a predetermined position to a position where the liquid discharge head is to discharge the liquid to the target pixel.

2. The liquid discharge device according to claim 1 , wherein
a target nozzle for forward travelling S F of the liquid discharge head is denoted as N F0 and preceding and subsequent backward travelling to the forward travelling S F are denoted as S B ,
a nozzle positioned, upon initiation of operation of backward travelling S B of the liquid discharge head, on an upstream side in the conveyance direction closest to a position of the target nozzle N F0 in the conveyance direction upon initiation of operation of the forward travelling S F of the liquid discharge head is regarded as a target nozzle N B0 for the backward travelling S B ,
an amount of conveyance of the object by the conveyor, from initiation of operation of the forward travelling S F to arrival at a position, where the liquid can be discharged to the target pixel, is denoted as Y,
a quotient and a remainder derived by dividing the amount of conveyance Y by a nozzle pitch NP are denoted as P and Q, respectively, and
the controller controls on which reciprocating travelling of the liquid discharge head to discharge the liquid and from which nozzle in the nozzle array to discharge the liquid according to a value of the remainder Q.

3. The liquid discharge device according to claim 2 , wherein the controller forms a dot of the target pixel by a nozzle N FP at a position P nozzles apart from the target nozzle N F0 on a downstream side in the conveyance direction on the forward travelling S F when the remainder Q is more than or equal to zero and less than one fourth of the nozzle pitch NP,
the controller forms the dot of the target pixel by a nozzle N BP at a position P nozzles apart from the target nozzle N B0 on the upstream side in the conveyance direction in the backward travelling S B when the remainder Q is more than or equal to one fourth and less than three fourths of the nozzle pitch NP, and
the controller forms the dot of the target pixel by a nozzle N FP+1 at a position (P+1) nozzles apart from the target nozzle N F0 on the downstream side in the conveyance direction on the forward travelling S F when the remainder Q is more than or equal to three fourths of the nozzle pitch NP and less than the nozzle pitch NP.

4. The liquid discharge device according to claim 1 , wherein the conveyor conveys the object at a constant speed, and
the movement driver moves the liquid discharge head at a constant speed at least in a region where the liquid discharge head discharges the liquid.

5. The liquid discharge device according to claim 1 , wherein the controller is configured to control the moving speed of the liquid discharge head by the movement driver and the conveyance speed of the object by the conveyor such that the moving speed and the conveyance speed are proportional to each other in both of a region of acceleration and deceleration where the liquid discharge head is either accelerated or decelerated and a region of constant speed where the liquid discharge head moves at a constant speed.

6. The liquid discharge device according to claim 1 , wherein the controller changes image data based on a determination as to whether to form a dot with each of the nozzles in the nozzle array.

7. The liquid discharge device according to claim 6 , wherein the controller performs processing of conversion into data of a bit number allowing the liquid discharge head to discharge and then changes the data of the bit number based on the determination as to whether to form a dot with each of the nozzles in the nozzle array.

8. The liquid discharge device according to claim 1 , wherein the liquid discharge head comprises a plurality of rows of the nozzles, and
the controller performs the control for each of the rows of the nozzles.

9. The liquid discharge device according to claim 1 , wherein the controller is configured to discharge the liquid onto the object during an oblique printing operation by controlling the discharge driver to instruct the liquid discharge head to discharge the liquid while the movement driver moves the liquid discharge head such that the liquid is discharged onto the object without halting conveyance of the object.

10. The liquid discharge device according to claim 1 , wherein the controller is configured to control on which reciprocating travelling of the liquid discharge head to discharge the liquid and from which nozzle in the nozzle array to discharge the liquid according to a remainder Q derived by dividing an amount of conveyance Y of the object by a nozzle pitch NP of the nozzle array.

11. A liquid discharge control method, performed by a liquid discharge device, the liquid discharge device including a nozzle array, a movement driver, a discharge driver, and a conveyor, the nozzle array being disposed in a conveyance direction in which an object is conveyed, the movement driver configured to move a head to discharge a liquid from the nozzle array in a direction perpendicular to the conveyance direction in a reciprocating manner, the discharge driver configured to instruct the head to discharge the liquid while the movement driver moves the head and, the conveyor configured to convey the object while the movement driver moves the head, the method comprising:
setting a moving speed of the head by the movement driver and a conveyance speed of the object by the conveyor such that the moving speed remains proportional to the conveyance speed in response to either an acceleration and a deceleration the head;
determining on which reciprocating travelling of the head to discharge the liquid to a target pixel based on an amount of conveyance of the object by the conveyor over a period during which the head moves from a predetermined position to a position where the head is to discharge the liquid to the target pixel; and
determining from which nozzle in the nozzle array to discharge the liquid to the target pixel based on the amount of conveyance of the object by the conveyor over the period.

12. The liquid discharge control method according to claim 11 , wherein
a target nozzle for forward travelling S F of the head is denoted as N F0 and preceding and subsequent backward travelling to the forward travelling S F are denoted as S B ,
a no

Assignees

• Takagi Yasunobu
• Sakamoto Kaoru
• Ito Yoichi
• Ricoh Co Ltd

Inventors

• Takagi Yasunobu
• Sakamoto Kaoru
• Ito Yoichi

Classifications

• B41J25/005 Primary

  for serial printing movements superimposed to character- or line-spacing movements · CPC title

• B41J2/1433 Primary

  Structure of nozzle plates · CPC title