摘要:
A liquid crystal display device comprises a liquid crystal layer sandwiched between upper and lower electrode substrates subjected to aligning treatment. The liquid crystal layer includes a nematic liquid crystal added with a chiral material and has a 160.degree.-360.degree. twisted helical structure. A pair of polarizers are disposed adjacent to the electrode substrates with their polarization or absorption axes inclined by respective predetermined angles with respect to the aligning directions of the electrode substrates. At least one of the polarizers is formed by a color polarizer for compensating a wavelength dependence of transmittance (or the coloring due to birefringence) resulting from the anti-coincidence between the polarization or absorption axis of the polarizer and the aligning direction of the electrode substrate, i.e. an optical axis of liquid crystal molecules adjacent to the substrate, so that light emerging from the device becomes approximately achromatic or colorless.
摘要:
A power supply circuit for a high voltage driven device, particularly a magnetron, is described. The power supply circuit comprises first and second switching elements, an inverter circuit including a commutating reactor connected in series with the first and second switching elements and a capacitor connected to a center tap of the commutating reactor, a transformer connected to an output of the inverter circuit, and a third switching element connected in parallel with a series circuit comprising the capacitor, the primary winding of the transformer and a portion of the commutating reactor. When the magnitude of a current flowing in the transformer exceeds a predetermined level, the third switching element is fired to establish a discharge loop for the capacitor through the series circuit whereby the amplitude of the current supplied to the transformer is limited below the predetermined level.