A one piece hollow watch crystal which prevents the condensation of water on the underside of the crystal of a watch. This crystal is of such construction so that it may be used on the common watch case bezels. The interior space of the device receives demoisturized air or may be vacuumed out.

A linear array of compounded liquid crystal cells comprises a first plurality of linearly aligned cells formed between the opposite surfaces of a pair of parallel plates and a second plurality of linearly aligned (compounding) cells formed between a surface of one of the pair of plates and a third parallel plate. The cells are filled with liquid crystals, and each liquid crystal cell is defined by a pair of oppositely disposed light-transmitting electrodes on the opposite surfaces, respectively,...

A narrow band transmission system using a crystal filter having a pass band width in the order of one hertz and operable over an ambient temperature range of 60.degree. C. The output of a crystal controlled oscillator is mixed with the incoming signal to provide a sum signal as the input to the filter. The oscillator and filter crystals have matched temperature characteristics so that the oscillator frequency and the filter center frequency vary in the same amount with change in temperature.

A crystal growth apparatus suitable for preparing epitaxial films of Group III(a) - V(a) compounds by tipping techniques is described. The novel apparatus includes means for removing deleterious oxides from the surface of source solutions prior to the deposition thereon of seed crystals.

A device characterized by an electronically-tunable optical birefringence over the range of 0.0 to 0.2 for applied voltages below 25 volts rms includes a thin film of a nematic liquid crystal. The tunable birefringence occurs below the threshold for dynamic scattering and is the result of electric-field-induced spatially-uniform molecular reorientation in a well-aligned nematic liquid crystal. Applications for such a cell include display elements, tunable retarders, color modulators and variable...

To provide a uniform composition of the liquid crystal material throughout the device, the interior surfaces of the device are coated or contacted, prior to filling with the liquid crystal material, with certain additive materials normally contained in the liquid crystal material to improve the device performance.

A novel crystal form of ,.alpha.-dimethyl-4-{1-hydroxy-4-{4-(hydroxydiphenylmethyl)-1-piperidinyl} butyl}benzeneacetic acid hydrochloride, processes for its preparation and its pharmaceutical use are disclosed.

A quartz crystal unit using a metallic base and improved in its shock resistance includes a circular plate-like crystal blank having first and second extending electrodes respectively extended from excitation electrodes, first and second L-letter-shaped metallic brackets electrically and mechanically connected to the first and second extending electrodes at the outer circumferential portion of the crystal blank, first and second lead wires constituted as hermetic terminals penetrating the metall...

A transistor oscillator has a piezoelectric crystal vibrator incorporated therein for the stabilization of the oscillation frequency and for producing an oscillator which may oscillate with a subharmonic of said crystal vibrator and with a middle wave range frequency.

A quartz-crystal oscillator comprises an oscillating stage and a buffering stage. The oscillating stage has a resonance circuit including a quartz-crystal unit and a capacitor, and an inverting amplifier amplifying a resonance frequency component of the resonance circuit due to feedback oscillation. The buffering stage is provided for outputting the output of the oscillating stage by reducing the amplitude thereof, and has first and second MOS FETs of the same conductive type arranged in series ...