| 摘要 |
PURPOSE:To reduce the displacement of movable plates of an optical shutter to a half as much as before and to reduce the size of peripheral materials, and to obtain the small-sized optical shutter by moving the two movable slit plates in the mutually opposite directions synchronously and intermitting light. CONSTITUTION:The movable plates 41-1 and 41-2 with a slit are provided at the tip of a reinforcing elastic plate 40 equipped with two electrostrictive elements as driving sources, and A1-A1 is superposed upon A0-A0. Then the plates are displaced by W/2 to obtain the maximum aperture rate by the displacement which is a half as large as conventional displacement W. The method of driving the couple of movable plates is out-of-phase relation attains the purpose by making the polarity of the electrostrictive elements opposite to each other when the elements are driven. When the plates are driven electromagnetically, said electrostrictive elements are substituted with permanent magnets which have the different polarities in an electromagnetic field for driving. |
