发明名称 |
An apparatus and method for correcting offset and gain drift present during communication of data |
摘要 |
<p>The present invention is directed to a system and method for compensating for offset and gain drift in a fast scan direction during an image forming process. To achieve compensation, the present invention samples a plurality of permanently darkened pixels upon powering up image sensors and circuitry therefor and during a sub-scanning process of an image and feeds this information into an offset value generating circuit. The offset generating circuit continually adjusts a pixel offset voltage according to a difference between sequential samples of the permanently darkened pixel, thereby compensating for fast scan offset drift. The present invention also samples a plurality of active pixels during a scanning of a calibration strip. From this scan, a gain corrective value is calculated. The present invention then samples active pixels during a scanning of a platen background. In response to this sampling, the gain corrective value is continually adjusted according to a difference between sequential samples of the platen background, thereby compensating for fast scan gain drift. The present invention can also compensate and balance transfer functions for a plurality of communication channels in a multi-channel system by using the same target values and same reference signals for each channel. <IMAGE></p> |
申请公布号 |
EP0862320(A2) |
申请公布日期 |
1998.09.02 |
申请号 |
EP19980108508 |
申请日期 |
1994.07.01 |
申请人 |
XEROX CORPORATION |
发明人 |
GUSMANO, DONALD J.;LOVETTE, WHYNN V.;HAYES, FREDERICK O.;ROSSI, ROBERT J. |
分类号 |
H04N1/19;G06T1/00;H04N1/401;H04N1/407;(IPC1-7):H04N1/407 |
主分类号 |
H04N1/19 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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