| 摘要 |
A light modulating device for use in a projection optical system comprises a visco-elastic light modulating layer (66) disposed over a unidirectionally conductive faceplate (28) of a cathode ray tube for applying an electrical pattern by way of one set of electrodes to the layer in order to form elemental phase diffraction gratings, and a further set of electrodes is provided which are capacitively coupled with the first set of electrodes for supplying electrical signals externally of the tube for controlling the electrical pattern applied by the tube. |
