FREE-SPACE OPTICAL COMMUNICATION DEVICE WITH DUST-PROOF GLASS PROCESSED IN WATER REPELLENT TREATMENT

PROBLEM TO BE SOLVED: To provide a free-space optical communication device for performing information transmission by using light passing through the open air capable of preventing communication failures caused by rainwater flowing down a front glass. SOLUTION: The free-space optical communication device for performing the information transmission by using light passing through the open air comprises a beam lighting unit provided with an optical system for emitting a parallel light bundle, and a light receiving unit provided with an optical system for condensing the light emitted from the beam lighting unit. The beam lighting unit and the light receiving unit are disposed opposite to each other. The device has an optical element forming part of the optical system of the beam lighting unit and for preventing dust, etc. The optical element is processed for water repellency on the surfaces in contact with the open air. COPYRIGHT: (C)2004,JPO