Abstract: A projection apparatus includes three liquid crystal panels for independently controlling respective color light components of red, green and blue for a color image to be reproduced. The apparatus further includes devices for subjecting the respective color light components to additive mixture so as to reproduce the color image. Each of the liquid crystal panels is constituted by a nematic type simple matrix liquid crystal panel having twist angle .phi. of its liquid crystal molecule represented by210.degree..ltoreq..phi..ltoreq.300.degree..

Abstract: Disclosed is an improvement of an active matrix type liquid crystal display device using a combination of a specific mixed liquid crystal and a specific polyimide orientation film.

Abstract: A liquid crystal display device which comprises first and second electrode substrates spaced a predetermined distance from each other, a nematic liquid crystal layer added with an optically active material and having a positive dielectric anisotropy, which layer is sandwiched between the first and second electrode substrates such that the liquid crystal molecules exhibit a helical structure in which they are twisted in a predetermined twist angle in a direction across the thickness of the liquid crystal layer, a light detecting element positioned on one side of the first electrode substrate remote from the liquid crystal layer, a polarizing element positioned on one side of the second electrode substrate remote from the liquid crystal layer, and a film-like sheet having a birefringence and disposed between the light detecting element and the first electrode substrate, and/or between the polarizing element and the second electrode substrate.

Abstract: A liquid-crystal display device of the twisted nematic type which comprises (1) a pair of electrode substrates facing each other, each being provided with an orientation membrane, the surface of which is treated by rubbing, and (2) a specific nematic liquid-crystal composition having a positive dielectric anisotropy containing a pyrimidine derivative of formula (I), ##STR1## wherein R.sub.1 and R.sub.2 are each a straight-chain alkyl group of 1 to 12 carbon atoms and containing an optically active substance, sandwiched between the two electrode substrates and arranged so that the axes of the liquid-crystal molecules will be twisted by an angle .phi. in the range of 210.degree..ltoreq..phi..ltoreq.300.degree., which shows excellent multiplex driving characteristics and suitable for use in display units of heavy-duty multiplex driving type.