Electronically gated paper aligner system
AssigneeInternational Business Machines Corporation
InventorsRobert B. Barker, Ronald V. Davidge, David K. Gibson, George W. Van Cleave
Life of this patent
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Abstract
In a xerographic image transfer device, copy sheets are sequentially aligned and position sensed before introduction to the image transfer zone. The position sensing is used to compare the copy sheet location with the position of the image panel on a moving photoconductor. The timing and velocity profile of the copy sheet drive after the position sensing is arranged so that the copy sheet arrives in registry with the image panel and at the same velocity.
Claims14
A sheet handling device adapted to feed sheets in synchronism with an image on the surface of a moving photoconductor comprising:
- conveying means operable to transport sheets along a predetermined path toward the photoconductor;
- sensing means disposed relative to said predetermined path for generating a first signal representative of the passing of a sheet along said path;
- means operable for generating a second signal corresponding to the location of an image zone on the photoconductor;
- and
- controller means responsive to said first and second signals for controlling the velocity of said conveying means for synchronously engaging the sheet with the photoconductor image zone as the sheet exits said predetermined path.
In a xerographic device having a moving photoconductor on which an image panel is located, a source of copy sheets and means for transferring images from the panel to the copy sheets, an improvement comprising:
- means for sequentially conveying copy sheets along a path from the copy sheet source, said conveying means including a belt;
- means for retaining the sheets in a relatively fixed position with respect to said belt, and means for moving said belt;
- means for aligning a side edge of each copy sheet on said conveying means with a reference line parallel to the direction of movement of said belt;
- means producing an output signal indicative of passage of sheet leading edges past a predetermined location relative to said conveying means for sheets aligned by said aligning means;
- and
- control means monitoring movement of the photoconductor image panel and responsive to said output signal producing means for actuating said belt moving means so that the copy sheet leading edge engages the photoconductor image panel leading edge with a common velocity therebetween prior to image transfer to the copy sheet from the photoconductor by the transferring means.
The method of synchronously engaging a copy sheet with an image zone of a moving photoconductor comprising the steps of:
- transporting the copy sheet along a path toward the photoconductor;
- sensing the arrival of the copy sheet at a predetermined location along said path;
- monitoring the position of the photoconductor image zone;
- determining the velocity profile for movement of the copy sheet from said predetermined location to registry with the photoconductor image zone so that the copy sheet and photoconductor move with a common velocity at the time of registry;
- and
- moving the copy sheet from said predetermined location into registry with the photoconductor image zone in conformity with said velocity profile.
Dependencies are inferred from the claim text.