David J Nienaber, 583480 Mirror Ln, Cincinnati, OH 45248

4553141, Nov 12, 1985

Sep 21, 1982

6/420759

Michael D. Flasza - Schaumburg IL
David K. Nienaber - Des Plaines IL

Zenith Electronics Corporation - Glenview IL

G09G 128

340703

A color monitor includes R G and B gain blocks, in the form of balanced multipliers, and a potentiometer picture control for supplying a common DC gain control voltage to the differentially coupled transistor pairs in the gain blocks. A common black level control adjusts the zero level for the signals. Changes in gain control voltage do not affect black level or color balance of the picture tube display.

4863233, Sep 5, 1989

May 12, 1988

7/193464

David K. Nienaber - Rolling Meadows IL
Gary G. Schoeffel - Island Lake IL

Zenith Electronics Corporation - Glenview IL

G02B 636
H04B 328
G02F 100
H04N 312

350 9620

An EMR containment system coupling an EMR contained computer chassis and a wide band video monitor includes three plastic fiber optic cables terminated in a plug at each end. The computer chassis includes a socket having an electrically conductive surface in which three cylindrical fiber optic wave guides are positioned, each having at least a 3/1 ratio of length to diameter. Optical diodes are positioned at the end of each wave guide for coupling wide band R, G and B video and sync signals to and from the fiber cables when the plugs are seated within the sockets. A microswitch communicates with the rear of one of the sockets and is physically operable by a removable actuator carried by the mating plug for selecting between monochrome and color monitors.

5394020, Feb 28, 1995

Dec 30, 1992

7/998282

David K. Nienaber - Rolling Meadows IL

Zenith Electronics Corporation - Glenview IL

H03K 406

327140

A vertical ramp generator includes a voltage controllable charge current source and a switched discharge current source coupled across a ramp capacitor. A pair of comparators coupled to first and second reference potentials are supplied with the ramp capacitor voltage and drive a flip/flop, the output of which operates the discharge current source. A sync signal voltage is injected into the output of one of the comparators. Another comparator compares the ramp capacitor voltage with a third reference potential corresponding to the midpoint of the desired ramp voltage to control the switching of a pair of current sources that supply a square wave current to a correction capacitor which develops a DC correction voltage. The duty cycle of the square wave current is a function of the deviation of the ramp capacitor voltage from the third reference potential. The correction voltage controls the amount of current supplied by the charge current source.