The disclosure describes an optically addressable spatial light modulator (OASLM) having a light sensitive member and a distorted helix ferroelectric liquid crystal (DHFLC). In a first embodiment a hydrogenated amorphous silicon (a-Si:H) photodiode layer is in physical contact with the DHFLC layer. In another embodiment an integrated circuit member includes a photosensitive area and an associated metal pad for each OASLM pixel, the metal pads in physical contact with corresponding DHFLC pixel areas. In the first embodiment, a low magnitude AC voltage (less than three to seven volts peak to peak) is connected to the OASLM as operating voltage, preferably in the absence of a DC offset voltage. The OASLM pixel areas of the OASLM are selectively addressed by a writing light wavefront, to thereby activate corresponding pixel areas of the light sensitive member. The voltage/current that is photogenerated in the activated pixels of the photosensitive member cause a current to flow, activating the corresponding DHFLC pixel areas. In an alternate construction of the first embodiment, the OASLM includes an external diode connected thereacross, this diode being operable to dissipate internal charge that may build up in the DHFLC. Reading of the activated DHFLC pixel areas of the DHFLC may be by way of a transmission or a reflection mode.
|IPC||G02F 1/ 135 A I|
|State||Published - 17 Dec 1991|