OPTICAL SIGNAL TRANSMITTER, OPTICAL SIGNAL RECEIVER, AND OPTICAL SIGNAL TRANSMITTER-RECEIVER

摘要

PURPOSE: To obtain the indoor optical space transmitter in which safety to eyes is secured. CONSTITUTION: A light emitting element 7 emitting an infrared ray whose wavelength is 1.4 to 1.6μm is used for a light source, a light of the light emitting element 7 is modulated and emitted in an indoor space and reflected in an indoor structure member such as a ceiling 1 or a wall 2 to transmit the light and it is received by a light receiving element 8 for transmission of a digital signal. In this case, the indoor structure is structured to scatter the light so as to disturb the wave front of the light. Moreover, the light emitted from the light emitting element 7 is emitted via a scattering plate or the like to disturb the wave front of the light before the signal light is emitted to free space.