Printing media status sensing
AssigneeHewlett-Packard Company
InventorsJames R. Nottingham, Billy L. Knorpp
Life of this patent
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Abstract
A printing media position sensing device provides sheet medium position status information for synchronizing media transfer operations in a hard copy machine using a sheet feeder system. When a sheet is picked and transferred from a stack in a replaceable cartridge, refillable tray, or the like, to the input registration and feed mechanism of the hard copy machine, a detector senses the further exit motion of the picked sheet, thus providing an indication that the input registration and feed mechanism has taken control of the sheet. A signal indicative of this condition is used to release the sheet pick and transfer mechanism associated with the stack so that the sheet is free to leave the stack uninhibited. The exit sensor automatically resets for the next cycle.
Claims15
A print medium status device for a cut-sheet print media apparatus adapted to hold a replenishable stack of cut-sheet media and having a means for transferring a single sheet from said stack to a print media input means of a hard copy machine, said device comprising:
- a sensor, affixed within said cut-sheet print media apparatus and connected to said means for transferring, providing a first signal when a single sheet is located at any position between being in said stack and a position where said single sheet has a leading edge thereof positioned to be fed into said hard copy machine by said input means and a second signal when said input means moves said single sheet out of said any position and feeds said single sheet into said hard copy machine such that said single sheet is released from said means for transferring;
- and
- switching means, operatively coupled to said sensor for switching said sensor from providing said first signal to providing said second signal substantially coincidently with said print media input means inception of feeding said single sheet into said hard copy machine.
A motion detector for a cut-sheet print media picking and transferring apparatus having a stack of cut-sheet print media therein and adapted for use with a hard copy machine having an input mechanism for repetitively receiving consecutive single sheets of media from said apparatus and feeding each of said sheets of media into a hard copy machine printing subsystem, comprising:
- a digital sensor, mounted within said apparatus, providing a first state signal from when said picking and transferring apparatus is set to pick and transfer a sheet from said stack until said sheet is transferred to and moved by said input mechanism;
- and
- toggling means, adapted to come into frictional contact with said sheet as said sheet is fed by said input mechanism into said hard copy machine printing subsystem, for switching said digital sensor from providing said first state signal to providing a second state signal as frictional contact between said toggling means and said sheet being fed move said toggling means, said second state signal causing said sheet to be released by said picking and transferring apparatus.
In a refillable, cut-sheet print media apparatus for use with a hard copy machine, said apparatus having a stack of cut-sheet media therein, a sheet picking and transferring subsystem, and an interface for transferring a sheet from the apparatus to an input mechanism of the hard copy machine via a paper path at a predetermined transfer angle to the planar orientation of said stack, a print medium exit sensor comprising:
- a status sensor, affixed to said apparatus, for providing a first signal to said picking and transferring subsystem indicative of a top sheet of said stack being in any position between atop said stack and a position in which a leading edge of said sheet is engageable with said input mechanism, and for providing a second signal to said picking and transferring subsystem indicative of said sheet being engaged and fed by said input mechanism into said hard copy machine;
- and
- a trigger, coupled to said status sensor and in proximity to said interface such that a sheet engaged and being fed by said input mechanism into said hard copy machine is brought into frictional contact with said trigger due to said paper path transfer angle, said frictional contact causing said trigger to move and thereby change said status sensor from a condition of providing said first signal to a condition of providing said second signal.
Dependencies are inferred from the claim text.