Printer configured to execute multi-pass printing including printing using large feed amount

Patent metadata

Field	Value
Publication number	US-9662908-B2
Application number	US-201615045604-A
Country	US
Kind code	B2
Filing date	Feb 17, 2016
Priority date	Feb 20, 2015
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A printer performs a multi-pass printing including a (a)-print process, a (b)-print process, and a (c)-print process between the (a)-print process and the (b)-print process. The (c)-print process includes a (c 1 )-pass process, a (c 2 )-pass process, and a process for conveying a sheet feed amount greater than feed amount used in the (a)-print process after the (c 1 )-pass process and before the (c 2 )-pass process. An upstream gradient of dot recording rates of active nozzles used for the (c 1 )-pass process is greater than that for the (a)-print process. A downstream gradient of the dot recording rates for the (c 1 )-pass process is greater than or equal to that for the (a)-print process. A downstream gradient of the dot recording rates of for the (c 2 )-pass process is the same as the upstream gradient for the (c 1 )-pass process.

First claim

What is claimed is:

1. A printer comprising:
a print executing unit including:
a conveying mechanism configured to convey a sheet in a conveying direction;
a print head having a plurality of nozzles arranged in the conveying direction, each of the plurality of nozzles being configured to eject an ink droplet to form a dot on the sheet; and
a main scanning mechanism configured to execute a main scan by moving the print head in a main scanning direction perpendicular to the conveying direction; and

a controller configured to control the print executing unit to perform a multi-pass printing for printing a target image on the sheet with a plurality of pass processes, the plurality of pass processes forming a plurality of partial images respectively, two partial images formed with successive two pass processes overlapping partially, wherein K number of active nozzles consecutively arranged are selected from the plurality of nozzles for each of the plurality of pass processes, dot recording rates of the K number of active nozzles decreasing at an upstream gradient from a nozzle having a maximum dot recording rate among the dot recording rates of the K number of active nozzles toward a most-upstream nozzle of the K number of active nozzles in the conveying direction, the dot recording rates of the K number of active nozzles decreasing at a downstream gradient from a nozzle having the maximum dot recording rate toward a most-downstream nozzle of the K number of active nozzles in the conveying direction,
wherein the controller is further configured to control the print executing unit to perform:
executing an (a)-print process in which the conveying mechanism conveys the sheet a first amount and a pass process is executed with Ka number of active nozzles, the upstream gradient of the dot recording rates of the Ka number of active nozzles used in the (a)-print process being the same as the downstream gradient of the dot recording rates of the Ka number of active nozzles used in the (a)-print process;
executing, after the (a)-print process is executed, a (b)-print process in which the conveying mechanism conveys the sheet and a pass process is executed with Kb number of active nozzles, the upstream gradient of the dot recording rates of the Kb number of active nozzles used in the (b)-print process being the same as the downstream gradient of the dot recording rates of the Kb number of active nozzles used in the (b)-print process; and
executing a (c)-print process after the (a)-print process is executed and before the (b)-print process is executed,

wherein the (c)-print process includes:
executing a (c 1 )-pass process with Kc 1 number of active nozzles, the upstream gradient of the dot recording rates of the Kc 1 number of active nozzles used in the (c 1 )-pass process being greater than at least one of the upstream gradient and the downstream gradient of the dot recording rates of the Ka number of active nozzles used in the (a)-print process, the downstream gradient of the dot recording rates of the Kc 1 number of active nozzles used in the (c 1 )-pass process being greater than or equal to at least one of the upstream gradient and the downstream gradient of the dot recording rates of the Ka number of active nozzles used in the (a)-print process;
conveying the sheet a second amount with the conveying mechanism after the (c 1 )-pass process is executed, the second amount being greater than the first amount; and
executing a (c 2 )-pass process with Kc 2 number of active nozzles after the conveying mechanism conveys the sheet the second amount, the downstream gradient of the dot recording rates of the Kc 2 number of active nozzles used in the (c 2 )-pass process being the same as the upstream gradient of the dot recording rates of the Kc 1 number of active nozzles used in the (c 1 )-pass process.

2. The printer according to claim 1 , wherein the conveying mechanism includes:
an upstream holding unit configured to hold the sheet at a position upstream from the print head in the conveying direction; and
a downstream holding unit configured to hold the sheet at a position downstream from the print head in the conveying direction,
wherein the sheet is held under a first state during execution of the (a)-print process, the first state being a state under which the sheet is held by the upstream holding unit and the downstream holding unit,
wherein the sheet is held under a second state during execution of the (b)-print process, the second state being a state under which the sheet is not held by the upstream holding unit and is held by the downstream holding unit, and
wherein a held state of the sheet transitions from the first state to the second state during conveyance of the sheet the second amount in the (c)-print process.

3. The printer according to claim 2 , wherein the upstream holding unit includes:
a holding member for deforming and holding the sheet in a corrugated state, the holding member disposed between a downstream roller and a upstream roller in the conveying direction, the downstream roller disposed at a position downstream from the print head in the conveying direction, the upstream roller disposed at a position upstream from the print head in the conveying direction;
wherein the first state is a state under which the sheet is held by the holding member and the downstream holding unit, and
wherein the second state is a state under which the sheet is not held by the holding member and is held by the downstream holding unit.

4. The printer according to claim 1 , wherein the controller is further configured to select one of a plurality of types of control including first control and second control on a basis of at least one of characteristics of the sheet and a conveying path through which the sheet should be conveyed,
wherein the controller controls the print executing unit to perform a first process including the (a)-print process, the (b)-print process, and the (c)-print process when the first control is selected, and
wherein the controller controls the print executing unit to perform a second process, the second process including the (a)-print process and a (d)-print process, wherein the (d)-print process is different from the (b)-print process and the (c)-print process and excluding conveying the sheet the second amount.

5. The printer according to claim 1 , wherein the (c)-print process includes a plurality of pre-pass processes, the plurality of pre-pass processes including the (c 1 )-pass process, and
wherein at least one of the upstream gradient and the downstream gradient of the dot recording rates of the active nozzles used for one pre-pass process increases, as a number of pre-pass process which has been executed increases.

6. The printer according to claim 5 , wherein a number of active nozzles used for one pre-pass process decreases by an equal amount as the number of the pre-pass process which has been executed increases.

7. The printer according to claim 1 , wherein the (b)-print process includes a (bb)-pass process executed with Kbb number of active nozzles, Kbb being greater than Kc 2 .

8. The printer according to claim 7 , wherein the (b)-print process includes a plurality of executions of the (bb)-pass process,
wherein at least one of the upstream gradient and the downstream gradient of the dot recording rates of the Kbb number of active nozzles used in one (bb)-pass process decreases as a number of the (bb)-pass process which has been executed in the (b)-print process increases.

9. The printer according to claim 8 , wherein Kbb increases by an equal amount as the number of the (bb)-pass process which has been executed increases.

10. The printer according to claim 1 , whe

Assignees

• Brother Ind Ltd

Inventors

• Yoshida Yasunari

Classifications

• B41J13/0009

  control of the transport of the copy material · CPC title

• B41J2/5056

  using dot arrays providing selective dot disposition modes, e.g. different dot densities for high speed and high-quality printing, array line selections for multi-pass printing, or dot shifts for character inclination (B41J2/2132 takes precedence) · CPC title

• B41J11/008 Primary

  Controlling printhead for accurately positioning print image on printing material, e.g. with the intention to control the width of margins · CPC title

• B41J2/2132 Primary

  Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding (methods for local corrections by dot omission, image edge enhancement, or multi-pass mask selection G06K15/102; colour conversion H04N1/40) · CPC title

• B41J11/0005

  Curl smoothing, i.e. smoothing down corrugated printing material, e.g. by pressing means acting on wrinkled printing material · CPC title