Printer media feed encoder apparatus and method
AssigneeHewlett-Packard Company
InventorsRichard A. Kelley, Bruce G. Johnson
Life of this patent
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Abstract
A printer with a media feed apparatus has a media tray with a surface for supporting a stack of media sheets. A wave drive mechanism above the stack support surface has a media contact element operable to make contact with a top sheet of a media stack in the tray while moving in a feed direction to shift the top sheet in the feed direction. An encoder above the tray operates to detect motion of the top sheet. A controller may monitor the encoder to determine the speed of sheet motion, and set the speed of the wave drive mechanism to maintain the sheet motion above a threshold.
Claims20
A printer with a media feed apparatus comprising:
- a media tray having an upper media stack support surface;
- a wave drive mechanism above the stack support surface and having a media contact element operable to make contact with a top sheet of a media stack in the tray while moving in a feed direction to shift the top sheet in the feed direction;
- and
- an encoder above the tray and operable to detect motion of the top sheet.
A method of individuating a top sheet from a stack of media comprising:
- operating a wave drive mechanism over the top sheet to advance the sheet toward the stack;
- monitoring the motion of the sheet;
- and
- in response to monitoring, maintaining a rate of advance of the sheet above a preselected threshold.
A media sheet feed apparatus comprising:
- a media tray having an upper media stack support surface suitable for supporting a stack of media;
- a wave drive mechanism above the stack support surface and having a media contact element operable to shift a top sheet in a feed direction;
- and
- a controller connected to the wave drive mechanism and operable in response to depletion of the stack of media to increase the speed of operation of the wave drive mechanism.
Dependencies are inferred from the claim text.