| abstract |
Light and image transmission for a precisely controllable time duration is provided by two twisted nematic, liquid crystal cells sandwiched between three polarizers. The first and second polarizers are polarized in a first direction and the third polarizer is polarized in a second direction. If the first cell is not activated, the plane of polarization of light passed by the first polarizer is rotated by the first cell so that the light is absorbed by the second polarizer. If only the first cell is activated, the light and image are passed through the device. If the second cell is activated, the plane of polarization of the light passing through the second cell is no longer rotated so that the light is absorbed by the third polarizer. Circuitry for operating and a camera including the device are also disclosed. |