Patent ID: 7379674
Filing Date: 2008-05-27
Classification: H04B

Abstract:
1. An optical transmission device configured to perform two-way communication with other optical transmission devices which are spatially separated from the optical transmission device, the optical transmission device comprising: a light-emitting element for convening an electronic signal to an optical signal; a first light-receiving photodetector for signal detection for converting a received optical signal to an electronic signal; at least two other light-receiving photodetectors for position detection, each photodetector including a plurality of light receiving elements separated by a separating band having a width L, for detecting a receiving position of a luminous flux emitted from an other light-emitting element from one of the other optical transmission devices spatially separated from the optical transmission device, wherein each of the other light-receiving photodetectors are separate and independent from the first light-receiving photodetector; and a mirror adjustable so as to align an optical axis of the luminous fluxes emitted from the other light-emitting element from the opposed partner device with an optical axis of the luminous fluxes emitted from said light-emitting element of said optical transmission device in accordance with a detected position by the at least two other light-receiving photodetectors for position detection, wherein said at least two other light-receiving photodetectors for position detection are arranged so that receiving positions of said at least two light-receiving photodetectors are shifted a distance D which is greater than the width L of the separating band with respect to a plane perpendicular to the optical axis of the optical transmission device.