| 摘要 |
PURPOSE:To achieve miniaturization and improvement in reliability by providing an electro-optical chopper part disposed with liquid crystal having transparent electrodes between polarizer and analyzer and modulating incident infrared rays with time by applying voltage. CONSTITUTION:If molicule arrays of liquid crystal 12 are so disposed between two sheets of optical materials 13 gaving transparent electrodes 14 as to be parallel with the materials 13 and rotate 90 deg. and the thickness of the oiquie crysral is made larger than the wavelength of infraered rays, then the arraying of molecules vary with both and the angle of polarization of incident ligh rotates 90 deg.. If this is placed between polarizing plates of mutually parallel polarization directions, incident infrared rays do not transmit therethrough. When voltage is applied to the electrode films 14 by a liquid crystal driving circuit 17, electrode fields are produced between the films 14, causing the molecualr arrays to tilt parallel with the electric fields. Then, the incident infrared rays transmit without receiving the rotation of the plane of polarization. If this operation is repeated and the driving frequency of the applied voltage to the liquid crystal is changed, the time modulation of the incident infrared rays may be operated and the electro-optical chopper may be contained in the apparatus, thus miniaturization and reliability improvement may be achieved. |
