| 摘要 |
<p>PURPOSE:To realize miniaturization as well as increasing reliability of a printing device, by driving a liquid crystal light valve using a liquid crystal having the desired dielectric anisotropy with a 2-frequency switching signal. CONSTITUTION:The glass substrate 11 having the common electrode is opposed to the glass substrate 12 having the signal electrode, and a liquid crystal layer is held between these two substrata. Then these substrate are put between the polarizing plates which are orthogonal to each other to form a liquid crystal light valve. The dielectric anisotropy of the liquid crystal uses the nematic-type one which becomes positive and negative with the lower and higher frequencies then the cross frequency fc. Thus the liquid crystal molecule turns toward the electric field with application of the signal of low frequency fl and becomes vertical to the electric field direction with application of the signal of high frequency fh respectively. The polarizing directions are set orthogonal to each other on both surfaces of the liquid crystal layer having a twist nematic orientation, and thus the light is cut off with the signal fl and transmits with the signal fh respectively. The signal obtained by switching alternately the above two signals is applied to the common electrode with the adverse-phase fh to the fl applied to the signal electrode each. Then the adverse-phase signal to fh is applied to the signal electrode with the shutter open and the signal fl applied with the closed shutter respectively.</p> |
