ELECTRIC DIMMING DEVICE AND ITS DRIVING METHOD

摘要

The present invention relates to an electrical dimmer device and its driving method applicable to, for example, an image pickup unit and a display unit. In the present invention, when a control signal for stop adjustment is changed from its current value of stop adjustment (+/-VX1) to a larger value (+/-VY1) (when the light transmissivity of a positive type liquid crystal is raised, or when the light transmissivity of a negative type liquid crystal is lowered), the control signal is temporarily varied to an intermediate value (+/-VZ1) which is still larger than the larger value (+/-VY1). The energy of the still larger value (+/-VZ1) and a time during which that varied value is applied are determined in accordance with predetermined values. By doing so, it is possible to make a response speed when changing the light transmissivity extremely faster and thus attain a response time of, e.g. one field period of time or less required for a stop mechanism of video camera.