Media stackers

Patent metadata

Field	Value
Publication number	US-10745231-B2
Application number	US-201515760960-A
Country	US
Kind code	B2
Filing date	Nov 30, 2015
Priority date	Nov 30, 2015
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A media stacker (100) comprises a stacking platform (102), a feed mechanism (104), a media arresting mechanism (106) and a controller (108). The feed mechanism conveys media sheets for dispensing onto the stacking platform, wherein the media sheets are dispensed onto the stacking platform with a momentum imparted by the feed mechanism. The media arresting mechanism reduces the momentum of media sheets. The controller determines that a trailing edge of a media sheet is to be dispensed onto the stacking platform, and further control the media arresting apparatus to reduce the momentum of the media sheet in response to the determination.

First claim

The invention claimed is:

1. A media stacker comprising:
a stacking platform having a length and a distal edge from which to hang a portion of a printed media sheet that is disposed on the platform and has a length greater than the length of the stacking platform;
a feed mechanism to convey media sheets longer than the stacking platform for dispensing onto the stacking platform, wherein the media sheets are dispensed onto the stacking platform with a momentum imparted by the feed mechanism such that a portion of each media sheet rests on the stacking platform while a further portion of each media sheet extends beyond, and hangs from the edge of, the stacking platform;
a media arresting mechanism to reduce the momentum of media sheets;
a controller to operate the feed mechanism and media arresting mechanism to dispense a first major portion of a sheet to the stacking platform at a first speed and then a second, subsequent minor portion of the sheet at a second, lower speed by controlling the media arresting apparatus to reduce the momentum of the media sheet when dispensing the second minor portion to the stacking platform, the controller designating a portion of the sheet between the first major portion and the second minor portion as a deceleration portion for transition from the first speed to the second speed; and
a securing element moveable by the controller to apply pressure to fully arrest movement of a sheet when that sheet has been dispensed to the stacking platform;
the controller to operate the feed mechanism and securing element together to prevent a sheet from falling off the distal edge of the stacking platform.

2. A media stacker according to claim 1 wherein the controller is to control the feed mechanism to adjust a speed with which a media sheet is conveyed including an error margin with respect to length of the sheet when dispensing the second minor portion and trailing edge of the media sheet onto the stacking platform.

3. A media stacker according to claim 1 in which the controller is to determine when to reduce to the second, lower speed a speed at which the sheet is dispensed to the stacking platform using a timer and based on a time to dispense a media sheet which is conveyed by the feed mechanism.

4. A media stacker according to claim 1 comprising a trailing edge detector to detect the trailing edge of the media sheet.

5. A media stacker according to claim 1 wherein the securing element is moveable between a securing position, in which it acts to secure at least one media sheet on the stacking platform, and a retracted position; and the controller is to control the position of the securing element responsive to a determination that a media sheet is to be dispensed, wherein the controller controls the securing element to secure a media sheet.

6. A media stacker according to claim 5 in which the controller is to control the securing element responsive to a determination that a media sheet is to be dispensed to move from the securing position to the retracted position, and subsequently from the retracted position to the securing position, thereby securing the dispensed media sheet.

7. A media stacker according to claim 5 wherein the controller is to control the securing element such that there is a predetermined time spent in the retracted position.

8. A media stacker according to claim 5 wherein the securing element comprises a first surface to contact a media sheet on the stacking platform and a second surface to guide the leading edge of a subsequent media sheet to overlie a secured media sheet on the stacking platform.

9. A media stacker according to claim 1 wherein the controller is to determine when to reduce to the second, lower speed a speed at which the sheet is dispensed to the stacking platform by counting revolutions of a roller in the feed mechanism.

10. A media stacker according to claim 1 wherein the second speed is a minimum speed of the feed mechanism.

11. A method comprising
dispensing a sheet of sheet media to a stacking platform such that the sheet, which is longer than the stacking platform, is partially disposed on the stacking platform, but extends beyond and hangs down from a distal edge of the stacking platform, the dispensing comprising:
conveying at least a portion of the sheet of sheet media with a first speed;
determining that a trailing edge of the sheet of sheet media is to be dispensed onto the stacking platform;
slowing a speed at which a trailing portion of the sheet that precedes the trailing edge is dispensed prior to releasing the sheet of sheet media onto the stacking platform with a second speed;
wherein a leading portion of the sheet from a leading edge to the trailing portion of the sheet is dispensed to the stacking platform at the first speed, which is faster than the second speed;
securing a stack of sheet media on a stacking platform in a registration position with a clamping force;
releasing the sheet having the second speed onto the stack parallel to the surface of the stack; and
releasing the stack from the clamping force securing the sheet having a lateral component of velocity parallel to the surface of the stack to the stack by reapplying the clamping force, wherein the clamping force reduces the second speed by arresting the sheet.

12. A method according to claim 11 in which the trailing portion comprises at least an inch of length of the sheet of sheet media.

13. A method according to claim 11 in which the leading portion is a majority of the sheet that is dispensed to the stacking platform at the first speed before conveying of the sheet is reduced to the second, slower speed in response to determining that the trailing portion of the sheet is to be dispensed onto the stacking platform.

14. A printer comprising:
a continuous print mode print engine to print large-scale media sheets of a meter or more in length;
a media stacker to receive and stack the large-scale sheets from the print engine;
a stacking platform of the media stacker, the stacking platform having a length and a distal edge from which to hang a portion of a printed large-scale sheet that is disposed on the platform and has a length greater than the length of the stacking platform;
a feed mechanism to convey the large-scale sheets that are longer than the stacking platform for dispensing onto the stacking platform, wherein the large-scale sheets are dispensed onto the stacking platform with a momentum imparted by the feed mechanism such that a portion of each sheet rests on the stacking platform while a further portion of each sheet extends beyond, and hangs from the edge of, the stacking platform;
a controller to use input from a sensor or a timer to determine when a trailing portion of each sheet is yet to be released to the stacking platform, the trailing portion comprising a predetermined amount of a sheet before a trailing edge of the sheet;
the controller to control a speed control module to control a speed at which successive sheets are conveyed to the stacking platform, wherein a first portion of a length of each sheet is conveyed at a first speed to the stacking platform, and the trailing portion of each sheet is conveyed to the stacking platform at a second speed which is lower than the first speed; and
a securing element moveable by the controller to apply pressure to fully arrest movement of a sheet when that sheet has been dispensed to the stacking platform;
the controller to operate the speed control module and securing element together to prevent a sheet from falling off the distal edge of the stacking platform.

15. The printer of claim 14

Assignees

• Hewlett Packard Development Co Lp

Inventors

• Deocon Mir Javier
• Martin Orue Eduardo
• Ortiz Mompel Josep

Classifications

• B65H2701/1313

  trailing edge · CPC title

• B65H2701/11312

  large formats, i.e. above A3 · CPC title

• B65H2513/20

  Acceleration or deceleration · CPC title

• B65H2513/11

  angular · CPC title

• B65H2301/4212

  of articles substantially horizontal · CPC title