ELECTRIC DIMMING DEVICE AND ITS DRIVING METHOD

摘要

An electric dimming device used in an imaging device or a display device, and a method for driving the device. When a diaphragm adjusting control signal is changed from the current diaphragm adjusting value (+/-VX1) to a large value (+/-VY1) (that is, when the light transmittance of a positive liquid crystal is raised the light transmittance of a negative liquid crystal is lowered), a period for which the value (+/-VZ1) is larger than the large value (+/-VY1). The energy and time of this large value (+/-VZ1) are determined according to a preset value. Therefore, the response speed of when the light transmittance can be remarkably raised, and a rate of change of one or less field period required as the diaphragm mechanism of a video camera can be realized.