Abstract: A light beam deflector employs first and second surface elastic waves to diffract guided waves split from a single light beam introduced into an optical waveguide. The surface elastic waves are generated respectively by first and second tilted-finger chirped interdigital transducers or curved-finger interdigital transducers which are arranged such that the first and second guided waves emittted out of the optical waveguide will scan a surface along respective aligned scanning lines, the ends of which scanning lines are adjacent to each other. The light beam deflector allows a large image to be recorded or read out because it has a wide deflection angle range. The first and second interdigital transducers may alternatively be arranged such that the first and second guided waves emitted out of the optical waveguide will scan the surface without overlapping each other.

Abstract: Reverse phase-controlled dimming of an a.c.-powered load is accomplished by switching power to the load on and off during each half cycle. In one embodiment of the present invention, power is switched on when line voltage is substantially equal to load voltage and off at a selected time later in the half cycle or at any time that the voltage across the switch exceeds a predetermined value. Preferably, switching is accomplished with a pair of field effect transistors. The load preferably includes a capacitor from load hot to neutral. The present circuit permits quiet dimming of incandescent lamp loads without the need for complex circuitry. It is particularly well adapted for dimming low voltage lamps using a solid state transformer.

Abstract: A plasma switch employs a cold cathode which yields secondary electrons to sustain a plasma within the switch. The cathode is provided with a series of perturbations which increase the effective cathode surface area exposed to the plasma and increase the average effective path lengths of secondary electrons emitted from the cathode and the probability of such electrons having ionizing collisions with gas molecules within the switch. The interior cathode surface is provided with a coating formed from chromium or a chromium mixture. Chromium combines a high rate of secondary electron emission with low sputtering and other advantageous properties for plasma switch operation. Various types of chromium-plated perturbations are described.

Abstract: An inverter is made up of a parallel circuit as a voltage resonance circuit, and a first diode, which are connected in series between both ends of a power source. The parallel resonance circuit includes the primary winding of an output transformer of the leakage type, and a resonance capacitor. The first diode is connected at the cathode to the primary winding of the output transformer. The secondary winding of the output transformer is coupled with a load such as a discharge lamp. The cathode and anode of the first diode are respectively connected to the collector and emitter of a transistor. A series circuit of a second diode and capacitor is connected across the collector-emitter path of the transistor. The second diode is forwardly arranged with respect to the transistor. A voltage detector comprises the capacitor and two resistors which are connected in series, and connected across the capacitor. The output voltage is derived from the node of those resistors.