Printing apparatus and platen

Patent metadata

Field	Value
Publication number	US-9802426-B2
Application number	US-201615160382-A
Country	US
Kind code	B2
Filing date	May 20, 2016
Priority date	May 27, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A platen includes: a plurality of supporting portions capable of supporting a sheet; negative pressure chambers, to which a negative pressure is supplied, so as to suck a sheet facing the supporting portions to the supporting portions; and ink receiver and that receive ink ejected from a printhead to the outside of the sheet supported by the supporting portions. The plurality of supporting portions are arranged in a sheet width direction (i.e., an X direction) transverse a sheet conveyance direction. The plurality of negative pressure chambers are disposed in a manner corresponding to the plurality of supporting portions, respectively.

First claim

What is claimed is:

1. A printing apparatus comprising:
a printhead configured to eject ink;
a sheet conveying unit configured to convey a sheet in a first direction, and
a platen unit configured to support the sheet to be printed by negative pressure suction,
the platen unit comprising:
a plurality of supporting portions each having a suction hole, arranged in a second direction perpendicular to the first direction;
a plurality of negative pressure chambers, arranged in the second direction and disposed under the supporting portions in a gravitational direction, each configured to supply a negative pressure to one or more of the supporting portions through the suction hole; and
an ink groove configured to receive ink ejected from the printhead to an outside of the sheet supported by the supporting portions,
wherein the ink groove has a shape extending in the second direction and is disposed outside the supporting portions in the first direction, and a bottom of the ink groove locates lower than a top inner surface of each one of the negative pressure chambers in the gravitational direction.

2. The printing apparatus according to claim 1 , wherein the platen unit further comprises an ink absorber disposed at the ink groove, and a bottom of the ink absorber locates lower than the top inner surface of each one of the negative pressure chambers in the gravitational direction.

3. The printing apparatus according to claim 1 , further comprising an adjusting unit configured to individually adjust the supply of the negative pressure to each of the plurality of negative pressure chambers.

4. The printing apparatus according to claim 3 , wherein
the adjusting unit adjusts the supply of the negative pressure such that the negative pressure is supplied to the negative pressure chambers corresponding to the supporting portions that support the sheet while no negative pressure is supplied to the negative pressure chambers corresponding to the supporting portions that do not support the sheet.

5. The printing apparatus according to claim 3 , wherein the adjusting unit is disposed in each of the plurality of negative pressure chambers, the adjusting unit including a valve configured to interrupt the negative pressure supplied from a negative pressure generating unit and a unit configured to switch the opening or closing of the valve.

6. The printing apparatus according to claim 5 , wherein the adjusting unit includes, on a common shaft, cam mechanisms configured to switch the opening or closing of the valves, respectively, so that upon rotation of the shaft, the opening/closing of each of the valves is switched at a cam phase of each of the cam mechanisms.

7. The printing apparatus according to claim 5 , wherein out of the plurality of negative pressure chambers, no valve is disposed at the negative pressure chamber corresponding to the supporting portion that supports a sheet all the time.

8. The printing apparatus according to claim 5 , wherein a common second negative pressure chamber communicating with the plurality of negative pressure chambers via the valves is disposed under the plurality of negative pressure chambers.

9. The printing apparatus according to claim 1 , wherein the supporting portion, the negative pressure chamber, and the ink groove are formed into a single resin-molded component part that forms the platen unit.

10. A platen unit for supporting a sheet to be printed comprising:
a plurality of supporting portions each having a suction hole to support the sheet by negative pressure suction, arranged in a sheet widthwise direction;
a plurality of negative pressure chambers, arranged in the sheet widthwise direction and disposed under the supporting portions in a gravitational direction, each configured to supply a negative pressure to one or more of the supporting portions through the suction hole; and
an ink groove configured to receive ink ejected from the printhead to an outside of the sheet supported by the supporting portions,
wherein the ink groove has a shape extending in the sheet widthwise direction and is disposed beside the supporting portions, and a bottom of the ink groove locates lower than a top inner surface of each one of the negative pressure chambers in the gravitational direction.

11. The platen unit according to claim 10 , further comprising an ink absorber disposed at the ink groove, wherein a bottom of the ink absorber locates lower than the top inner surface of each one of the negative pressure chambers in the gravitational direction.

Assignees

• Canon Kk

Inventors

• Onuma Takahide
• Kurata Tetsuji
• Ogasawara Seiji
• Tsukuda Masakazu
• Saito Yasunori

Classifications

• B41J2/185

  Ink-collectors; Ink-catchers · CPC title

• B41J11/0085 Primary

  Using suction for maintaining printing material flat (on rotatable drums B41J13/226) · CPC title

• B41J11/06

  Flat page-size platens {or smaller flat platens having a greater size than line-size platens (B41J11/0085 takes precedence)} · CPC title

• B41J11/0065

  Means for printing without leaving a margin on at least one edge of the copy material, e.g. edge-to-edge printing · CPC title

• B41J11/0005 Primary

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