Lynn L Ackler

US Patent:

53030648, Apr 12, 1994

Filed:

Feb 20, 1991

Appl. No.:

7/658177

Inventors:

Kent Johnson - Albany CA
Lynn L. Ackler - Alameda CA
David C. Jenkins - Loomis CA
Howard H. Barney - Berkeley CA
Chris A. Brooks - Alameda CA

International Classification:

H04N 146

US Classification:

358406

Abstract:

A calibrated scanner is disclosed. The calibrated scanner includes a sensor board with a Charge Coupled Device (CCD) having two output signals. The sensor board also includes two offset devices, a coarse offset and a fine offset, the coarse offset being connected to the two output signals, the fine offset being connected to one of the output signals. The offsets are adjusted to provide a nonclipping DC bias for the two output signals. The sensor board also includes two gain devices, one gain device being attached to each output signal. The gain devices are adjusted to balance the two output signals. After these adjustments, the saturation level of the CCD is determined. The saturation level information is then used in readjusting the gain and offset devices. After this calibration, a linear correction may be applied to the output signal of the sensor board. The linear correction is accomplished by determining dark and light values of the sensor board.