Inkjet printer and method for acquiring gap information

Patent metadata

Field	Value
Publication number	US-9511606-B2
Application number	US-201514879927-A
Country	US
Kind code	B2
Filing date	Oct 9, 2015
Priority date	Mar 30, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

An inkjet printer is provided, which is configured to acquire gap information related to a gap between an ink discharging surface and a recording sheet in each individual position of top-formed positions and bottom-formed positions within a predetermined wave-shape generating range, identify, when the predetermined wave-shape generating range includes a partial range in which the recording sheet is not placed, a top-formed position where the gap information has not been acquired and a bottom-formed position where the gap information has not been acquired, within the partial range, complement the unacquired gap information in the identified top-formed position with a value determined based on the respective pieces of gap information acquired in other top-formed positions, and complement the unacquired gap information in the identified bottom-formed position with a value determined based on the respective pieces of gap information acquired in other bottom-formed positions.

First claim

What is claimed is:

1. An inkjet printer comprising:
an inkjet head configured to discharge ink droplets from nozzles formed in an ink discharging surface thereof;
a head scanning unit configured to reciprocate the inkjet head relative to a recording sheet along a scanning direction parallel to the ink discharging surface;
a sheet deforming mechanism configured to deform, in a predetermined range within a movable range of the inkjet head in the scanning direction, the recording sheet in a particular shape that has a plurality of tops and a bottom farther away from the ink discharging surface than the plurality of tops in a particular direction orthogonal to the ink discharging surface, the bottom being positioned between the plurality of tops in the scanning direction; and
a control device configured to:
acquire gap information related to a gap between the ink discharging surface and the recording sheet in each individual position of a plurality of top-formed positions and a bottom-formed position, each top-formed position being a position where a corresponding one of the plurality of tops is formed on the recording sheet, the bottom-formed position being a position where the bottom is formed on the recording sheet;
identify a specific top-formed position where the gap information is not acquired, from among the plurality of top-formed positions; and
complement the gap information that is not acquired in the identified specific top-formed position, with a value determined based on the respective one or more pieces of gap information acquired in one or more top-formed positions other than the identified specific-top-formed position of the plurality of top-formed positions.

2. The inkjet printer according to claim 1 ,
wherein the control device is further configured to determine ink discharging timing to discharge the ink droplets from the nozzles during movement of the inkjet head along the scanning direction, using the gap information in the plurality of top-formed positions and the one or more bottom-formed positions.

3. The inkjet printer according to claim 1 ,
wherein the control device is further configured to provide a notification that it is impossible to properly acquire the gap information, when a number of identified specific top-formed positions is equal to or more than a predetermined number.

4. The inkjet printer according to claim 1 ,
wherein the control device is further configured to:
control the inkjet head and the head scanning unit to print deviation detecting patterns to detect positional deviation values in the scanning direction of the ink droplets discharged from the nozzles onto the plurality of tops and the bottom of the recording sheet that are respectively formed in the plurality of top-formed positions and the bottom-formed position within the predetermined range during movement of the inkjet head along the scanning direction;
read the deviation detecting patterns printed on the recording sheet;
acquire, as the gap information related to the gap between the ink discharging surface and the recording sheet, a positional deviation value of an ink droplet discharged in each individual position of the plurality of top-formed positions and the bottom-formed position, based on the read deviation detecting patterns; and

when a deviation detecting pattern corresponding to one of a top-formed position and a bottom-formed position is not read, determine that the positional deviation value is not acquired in the one of the top-formed position and the bottom-formed position.

5. The inkjet printer according to claim 1 ,
wherein the control device is further configured to:
detect both ends of the recording sheet in the scanning direction; and
identify, from among the plurality of top-formed positions, the specific top-formed position where the gap information is not acquired, based on both the detected ends of the recording sheet.

6. The inkjet printer according to claim 1 ,
wherein the control device is further configured to, when the recording sheet has a width in the scanning direction that is shorter than the predetermined range, identify the specific top-formed position where the gap information is not acquired.

7. An inkjet printer comprising:
an inkjet head configured to discharge ink droplets from nozzles formed in an ink discharging surface thereof;
a head scanning unit configured to reciprocate the inkjet head relative to a recording sheet along a scanning direction parallel to the ink discharging surface;
a sheet deforming mechanism configured to deform, in a predetermined range within a movable range of the inkjet head in the scanning direction, the recording sheet in a particular shape that has a plurality of bottoms and a top closer to the ink discharging surface than the plurality of bottoms in a particular direction orthogonal to the ink discharging surface, the top being positioned between the plurality of bottoms in the scanning direction; and
a control device configured to:
acquire gap information related to a gap between the ink discharging surface and the recording sheet in each individual position of a plurality of bottom-formed positions and a top-formed position, each bottom-formed position being a position where a corresponding one of the plurality of bottoms is formed on the recording sheet, the top-formed position being a position where the top is formed on the recording sheet;
identify a specific bottom-formed position where the gap information is not acquired, from among the plurality of bottom-formed positions; and
complement the gap information that is not acquired in the identified specific bottom-formed position, with a value determined based on the respective one or more pieces of gap information acquired in one or more bottom-formed positions other than the identified specific bottom-formed position of the plurality of bottom-formed positions.

8. The inkjet printer according to claim 7 ,
wherein the control device is further configured to determine ink discharging timing to discharge the ink droplets from the nozzles during movement of the inkjet head along the scanning direction, using the gap information in the plurality of top-formed positions and the bottom-formed position.

9. The inkjet printer according to claim 7 ,
wherein the control device is further configured to provide a notification that it is impossible to properly acquire the gap information, when a number of identified specific bottom-formed positions is equal to or more than a predetermined number.

10. The inkjet printer according to claim 7 .
wherein the control device is further configured to:
control the inkjet head and the head scanning unit to print deviation detecting patterns to detect positional deviation values in the scanning direction of the ink droplets discharged from the nozzles onto the plurality of bottoms and the top of the recording sheet that are respectively formed in the plurality of bottom-formed positions and the top-formed position within the predetermined range during movement of the inkjet head along the scanning direction;
read the deviation detecting patterns printed on the recording sheet;
acquire, as the gap information related to the gap between the ink discharging surface and the recording sheet, a positional deviation value of an ink droplet discharged in each individual position of the plurality of bottom-formed positions and the top-formed position, based on the read deviation detecting patterns; and

when a deviation detecting pattern corresponding to one of a bottom-formed position and the top-formed position is not read, determine that the positional deviation value is not acquired in the one of the top-formed position and th

Assignees

• Brother Ind Ltd

Inventors

• Arakane Satoru

Classifications

• B41J11/0095

  Detecting means for copy material, e.g. for detecting or sensing presence of copy material or its leading or trailing end · CPC title

• B41J29/393

  Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns} · CPC title

• B41J19/145

  Dot misalignment correction · CPC title

• B41J11/005

  Guides in the printing zone, e.g. guides for preventing contact of conveyed sheets with printhead · CPC title

• B41J25/308 Primary

  with print gap adjustment mechanisms · CPC title