| 摘要 |
PURPOSE: To allow its own transmitter to identify automatically an opposite transmitter to be connected to its own transmitter through a channel when plural optical space transmitters are installed close to the opposite transmitter side. CONSTITUTION: An optical modulator 150 is made up of mainly an optical reflector consisting of a liquid crystal shutter 29 and a corner cube prism 30 located close to the shutter 29, an identification signal generating circuit 32 and a liquid crystal drive circuit 33 controlling switchingly the liquid crystal shutter 29 coincident with an identification code specific to the optical space transmitter provided with the optical reflector. The optical modulator 150 is added to the opposite optical space transmitter to allow its own transmitter to emit a laser beam and the optical modulator 150 modulates the laser beam into a modulated light coincident with an identification code and the modulation light is fed back to its won transmitter. Its own transmitter receives the modulation light and demodulates it to decide the opposite transmitter. The optical modulator may be made up of a liquid crystal shutter, a convex lens and a mirror placed to a focus of the convex lens. |
