METHOD FOR REDUCING PRINTING POSITION ERROR AND IMAGE FORMING APPARATUS USING THE SAME
First Claim
1. A method for reducing a printing position error, the method comprising the steps of:
- (a) driving an encoder wheel as many times as a predetermined number of forward counts at a predetermined initial acceleration, thereby making the edge of a printing paper become separated from a sensing unit and conveyed in a forward direction;
(b) driving the encoder wheel at the predetermined initial acceleration and conveying the printing paper in a backward direction, thereby making the edge of the printing paper become in contact with the sensing unit and generating a number of backward counts;
(c) calculating a difference value between the number of backward counts of the encoder wheel from a start time of the backward driving to a point when the sensing unit detects the edge of the printing paper and the number of forward counts; and
(d) repeating the steps (a) through (c) for a designated number of times while varying the predetermined initial acceleration, and setting an initial acceleration corresponding to a smallest value among the difference values as the initial acceleration for driving the encoder wheel.
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Abstract
An apparatus and method are provided for reducing a printing position error, in which the method includes the steps of (a) driving an encoder wheel as many times as a predetermined number of forward counts at a predetermined initial acceleration, thereby making the edge of a printing paper become separated from a sensing unit and conveyed in a forward direction, (b) driving the encoder wheel at the predetermined initial acceleration and conveying the printing paper in a backward direction, (c) calculating a difference value between the number of backward counts of the encoder wheel from a start time of the backward driving to a point when the sensing unit detects the edge of the printing paper and the number of forward counts, and (d) repeating the steps (a) through (c) for a designated number of times while varying the predetermined initial acceleration, and setting an initial acceleration corresponding to a smallest value among the difference values as the initial acceleration for driving the encoder wheel. Therefore, in the case of separately printing data on one printing paper several times, the resolution of a printed image can be improved by reducing the printing position error.
57 Citations
20 Claims
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1. A method for reducing a printing position error, the method comprising the steps of:
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(a) driving an encoder wheel as many times as a predetermined number of forward counts at a predetermined initial acceleration, thereby making the edge of a printing paper become separated from a sensing unit and conveyed in a forward direction;
(b) driving the encoder wheel at the predetermined initial acceleration and conveying the printing paper in a backward direction, thereby making the edge of the printing paper become in contact with the sensing unit and generating a number of backward counts;
(c) calculating a difference value between the number of backward counts of the encoder wheel from a start time of the backward driving to a point when the sensing unit detects the edge of the printing paper and the number of forward counts; and
(d) repeating the steps (a) through (c) for a designated number of times while varying the predetermined initial acceleration, and setting an initial acceleration corresponding to a smallest value among the difference values as the initial acceleration for driving the encoder wheel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An image forming apparatus, comprising:
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an encoder wheel, which can be driven as many times as a predetermined number of forward counts at a predetermined initial acceleration, thereby making the edge of a printing paper become separated from a sensing unit and conveyed in a forward direction, and which can be driven in a backward direction to feed the printing paper in the backward direction to become into contact with the sensing unit and generate a number of backward counts; and
a driving control unit for calculating a difference value between the number of backward counts of the encoder wheel from a start time of the backward driving to a point when the sensing unit detects the edge of the printing paper and the number of forward counts, wherein, the driving control unit obtains a designated number of the difference values by varying the predetermined initial acceleration, and setting an initial acceleration corresponding to a smallest value among the difference values as the initial acceleration for driving the encoder wheel. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification