International Business Machines Corporation

Gary W Jorgenson

Craig Steven Cambier

Kenneth A Bushaw

Lawrence Paul Trubell

Ronald D Gillingham

Gary W Corner

Michael A Steffes

Clyde L Manning

A linear image sensor and the video channel associated with the sensor are calibrated to maximize the video signal available. The sensor is limited in output by saturation of the CCD analog shift registers in the sensor. The channel is limited by the range of the analog-to-digital converter in the channel. The useable video signal is maximized by calibrating the sensor relative to its saturation condition and by adjusting the gain of the video channel relative to the range of the analog-to-digital converter. The sensor is calibrated by adjusting its exposure to illumination. The adjustment may be made by adjusting the illumination source or by changing the sampling interval for the sensor. The gain is adjusted by using a variable gain amplifier. A microprocessor monitors the digitized video signal and controls the exposure and gain to calibrate the sensor and channel.

Method and apparatus for calibrating a linear array scanning system

A fluorescent lamp is adjusted in illumination intensity by controlling the DC current in the lamp during each alternate direct current flow through the lamp. The magnitude of the current applied to the lamp is set each time the direction of current through the lamp is switched, and the current change between switch times is limited. Inductors are used as current change limiting devices so that in each direction of current flow through the lamp, the current can not rapidly change. The amount of current is set, and the direction of current flow is switched when a current monitor detects that the current through one of the inductors is equal to the current desired for the operating point of the lamp. In this way, uniform selectable illumination levels may be achieved even though the lamp is operating in the negative resistance portion of its resistance characteristic.

Method and apparatus for variable current control of a negative

A motor control circuit for providing high acceleration currents by providing a driver comprising a transistor operating in the saturated region in parallel with a transistor operated in the nonsaturated region. The saturated transistor supplies the heavy accelerating current while the nonsaturated transistor is controlled to provide an increasing current through the accelerating period to make up for drops in the current flows through the saturated transistor due to build up of back emf in the motor.

High current acceleration servomotor driver

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Longmont, CO, United States of America

Gary W Jorgenson