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US 5,209,589 AGranted
Apparatus and method for minimizing printer scan error
AssigneeApple Computer, Inc.
InventorAnitta L. Bliss
Life of this patent
Estimating the term…
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AssigneeApple Computer, Inc.
InventorAnitta L. Bliss
Estimating the term…
In a printer assembly including a printhead which moves in a first direction for printing on a sheet of paper, roller means having an outer cylindrical periphery that engages the sheet of paper at successive tangent points on the periphery for moving the paper in a second perpendicular direction, and driving means for rotating the roller means, an apparatus for correcting certain pre-established errors in the positioning of the sheet of paper by the roller means is described. The apparatus comprises means for controlling the driving means such that the driving means rotates the roller means in order to move the sheet of paper in a way which eliminates the pre-established errors. An arrangement for determining certain pre-established errors in the positioning of the sheet of paper by the roller means is also described. The arrangement comprises light reflecting means coupled to the roller means, light emitting and sensing means for projecting a beam of light onto the light reflecting means while the roller means is rotating, and for measuring radius at the successive tangent points on the entire periphery of the roller means to determine the pre-established errors, and storage means for storing data corresponding to the pre-established errors measured by the light emitting and sensing means. A method for correcting certain pre-established errors in the positioning of the sheet of paper by the roller means and a method for determining the certain pre-established errors in the positioning of the sheet of paper by the roller means are also described.
For use in a printer assembly including a printhead which moves in a first direction for printing on a sheet of paper, roller means having an outer cylindrical periphery that engages said sheet of paper at successive tangent points on said periphery for moving the paper in a second perpendicular direction, and driving means for rotating said roller means, an arrangement for determining certain pre-established errors in the positioning of said sheet of paper by said roller means, comprising:
In a printer assembly including a printhead which moves in a first direction for printing on a sheet of paper, roller means having an outer cylindrical periphery that engages said sheet of paper at successive tangent points on said periphery for moving the paper in a second perpendicular direction, and driving means for rotating said roller means, a method for correcting certain pre-established errors in the positioning of said sheet of paper by said roller means, comprising the steps of:
For use in a printer assembly including a printhead which moves in a first direction for printing on a sheet of paper, roller means having an outer cylindrical periphery that engages said sheet of paper at successive tangent points on said periphery for moving the paper in a second perpendicular direction, and driving means for rotating said roller means, a method for determining certain pre-established errors in the positioning of said sheet of paper by said roller means, comprising the steps of:
Dependencies are inferred from the claim text.