US 5,973,727 AGranted

Video image viewing device and method

AssigneeNew Light Industries, Ltd.

InventorsStephen P. McGrew, P. David DeVries, Roger F. Wink, David H. Foster

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Abstract

A video image viewing device includes first and second glass plates having a layer of liquid crystal therebetween. A plurality of laser diodes extending along a line near one edge of the first plate are selectively illuminated at an intensity corresponding to the amplitude of a video signal during each of a plurality of video lines. The light propagates through the first plate via total internal reflection not entering the liquid crystal layer until it reaches an area where the refractive index of the liquid crystal is selectively modified. The refractive index may be modified by selectively energizing each of a plurality of horizontal strip electrodes vertically spaced from each other. The electrodes are sequentially energized to frustrate the total internal refraction and thereby cause the light to be transmitted through the liquid crystal layer into the second plate at a location corresponding to the location of video line in a video frame of the video signal. One or more holographic optical elements diffract light passing into the second plate to a predetermined direction, thereby forming a unique virtual image point location for each combination of single electrode pair activation and laser diode activation.

Claims29

Dependent claims

An image display device comprising:

a first plate comprised of a transparent material and having a first refractive index,
a light generator selectively directing light beams into the first plate at a plurality of respective locations along a surface of the first plate, the light beam being directed into the first plate in a manner that causes the light beams to propagate along the first plate with total internal reflection in the first plate,
an index of refraction modulator positioned adjacent the first plate, the index of refraction modulator having a plurality of modulating elements at respective areas spaced apart from each other in the first direction, each of the modulating elements being selectively controllable to either a first refractive index state or a second refractive index state responsive to a respective control signal, the first refractive index state causing the modulating element to have an index of refraction that is sufficiently lower than the index of refraction of the first plate to cause the light beam to remain internally reflected in the first plate in the area of the modulating element, and the second refractive index state causing the modulating element to have an index of refraction that is sufficiently higher than the index of refraction of the first plate to cause the light beam to exit the first plate in the area of the modulating element;
and
an optical element positioned adjacent the index of refraction modulator, the optical element controlling the angle of deflection of light exiting the first plate in the area of the modulating element.

2 more elements

Dependencies are inferred from the claim text.