| 摘要 |
PURPOSE: To relax tight requirements in the application of an optical back plane in a free space. CONSTITUTION: Requirements of arrangement in optical signal transmission in a free space are relaxed by the use of differential optical transmission. When a signal from an information source is an electric signal, an electronic supplement signal is generated and the signal and the supplement signal are respectively fed to light emitting elements 11, 13. Respective lights emitted from the light emitting elements 11, 13 are collimated by lenses 14, 15 and sent to light receiving lenses 16, 17. The collimated lights are collected by photo detectors 18, 19 that convert the light into an electric signal through the two light receiving lenses 16, 17, and electric signals from the two photo detectors 18, 19 are fed to a differential amplifier 20. The two lenses 14, 15 sending the signal and the supplement signal form a transmission pair and the two lenses 16, 17 receiving the signal and the supplement signal form a reception pair. |
