Abstract: The present invention relates to a light source device and particularly to a light source device which can be applied to a light source apparatus of a liquid crystal display apparatus which utilizes a flat plane type light source. The present invention provides a large size, light weight and thin flat plane light source which ensures uniform high level brightness to the entire part of display panel.

Abstract: A light source device disposing light sources at both end faces of the transparent plate in which a surface of the transparent plate in the side of an observer (front surface) is formed as the inclined and curved surface in view of limiting reduction in quantity of light per unit area at the observing area being far from the light source within a certain level, the one surface of the transparent plate is formed as the rough surface to diffuse the incident light, the other surface of the transparent plate is formed as a mirror-surface, and a reflecting layer having a high lightness is disposed at the lower side of the transparent plate in order to provide sufficient luminance for observers.

Abstract: A liquid crystal display device comprising a liquid crystal module including liquid crystal display panel having a plurality of liquid crystal picture elements arranged in a matrix form, and driving circuits for applying driving signals to signal electrodes and to scanning electrodes of the liquid crystal display panel, respectively; a control circuit for controlling the operation of the liquid crystal module; a first circuit for dividing frequency of a timing signal given by the control circuit and producing a first signal of lower frequency; and a second circuit for inverting the first signal of lower frequency once per frame period and generating a second signal to reverse the polarity of voltages applied to liquid crystal display elements with its period .tau..sub.M" satisfying the inequality2.0.ltoreq..tau..sub.F (the frame period)/.tau..sub.M" .ltoreq.6.0.

Abstract: Between a liquid crystal module and a control circuit for controlling said liquid crystal module, there are provided that a counter circuit for counting down a timing signal given by said control circuit and an exclusive-OR circuit whose inputs are square wave pulses delivered from said counter circuit and square wave pulses given by said control circuit with a period of twice the frame period. The polarity of voltages applied to liquid crystal module is reversed by square wave pulses delivered from the exclusive-OR circuit with frequency higher than the frame frequency.