ON-VEHICLE DEVICE

PROBLEM TO BE SOLVED: To provide an on-vehicle device that can perform full-duplex communication in at least part of an area where the on-vehicle device can communicate with a light emitter/receiver of an optical beacon.SOLUTION: A set of light transmission and reception units 2a (or 2b) includes an LED group 21a (or 21b) for transmitting an optical signal and a photodiode 22a (or 22b) for receiving an optical signal. A light shielding unit blocks light between the LED group 21a (or 21b) and the photodiode 22b (or 22a) between the light transmission and reception units 2a and 2b. Either a full-duplex communication method or a half-duplex communication method is selected according to an optical signal received by the photo diode 22a and/or the photodiode 22b.SELECTED DRAWING: Figure 3 【課題】光ビーコンの投受光器との通信が可能な領域内の少なくとも一部で全二重通信が行える車載機を提供する。【解決手段】１組の送受光部２ａ（又は２ｂ）に光信号を送信するＬＥＤ群２１ａ（又は２１ｂ）と光信号を受信するフォトダイオード２２ａ（又は２２ｂ）とが含まれており、送受光部２ａ及び２ｂの間でＬＥＤ群２１ａ（又は２１ｂ）及びフォトダイオード２２ｂ（又は２２ａ）の間が遮光部で遮光されている。そして、フォトダイオード２２ａ及び／又はフォトダイオード２２ｂで受信した光信号に応じて、全二重通信方式又は半二重通信方式の何れかの通信方式を選択する。【選択図】図３