Abstract: A parabolic light emitter incorporates a solid state light emitter embedded in a transparent body formed with one planar surface and an opposing surface formed as a paraboloid, the outer surface of which is coated with a light reflecting material. In one embodiment, a reflective member is interposed between the light emitter and the planar surface.

Abstract: A photoelectric touch input panel has a plurality of crossed light beams which are broken by an object, the position coordinates of which are identified as outputs. Two spaced apart beam surfaces are provided, and the interrelationship between the beams in the two planes is employed to distinguish between interrupting objects on the basis of their size, attitude, and velocity characteristics. The number of beams broken in any beam plane is counted to determine the relative size of the object, or to determine the center line of the interrupting object. The beams in any beam plane are selected in accordance with the relative significance of the various beams, and interrupted beams are pulsed more rapidly than non-interrupted beams. The light-emitting devices of the various beam planes are constructed as an integral unit.

Abstract: A photoelectric touch input panel has a plurality of crossed light beams which are broken by an object, the position coordinates of which are identified as outputs. Two spaced apart beam surfaces are provided, and the interrelationship between the beams in the two planes is employed to distinguish between interrupting objects on the basis of their size, attitude, and velocity characteristics. The number of beams broken in any beam plane is counted to determine the relative size of the object, or to determine the center line of the interrupting object. The beams in any beam plane are selected in accordance with the relative significance of the various beams, and interrupted beams are pulsed more rapidly than non-interrupted beams. The light-emitting devices of the various beam planes are constructed as an integral unit.

Abstract: A dynamic level shifter for photoelectric touch panels incorporating a plurality of photoelectric transducers periodically senses the ambient light level, immediately before the interval when each transducer can receive a pulse of radiant energy during normal operation of the panel. The output of the phototransducer during the such interval is compared with the output during the previous ambient interval, to develop a signal indicative of the presence or absence of the pulse, irrespective of ambient light fluctuations.