Liquid crystal shutter control circuit for a video camera having a synchronized strobe flash

摘要

A liquid crystal shutter, mounted on the side of a lens in a video camera, includes a pair of polarizing filters with a liquid crystal cell between them. A pulse generator generates a pulse for a predetermined length of time that is synchronized with a vertical synchronizing signal of a television signal. A controller controls an electrical field of the liquid crystal shutter to allow light from an object to be transmitted through the liquid crystal shutter in response to the pulse. Such liquid crystal shutter, having no mechanical moving parts, is much more durable than a mechanical shutter and can be easily maintained. In addition, the shutter apparatus, because it is controlled electrically, can work at high speed and can be easily synchronized with other systems.