| 摘要 |
PURPOSE:To hear the favorite contents of respective persons without a restriction sense and comfortably and to facilitate the fitting by modulating an infrared light corresponding to a sound signal, radiating it to a space in a vehicle room by a main body part and photodetecting and demodulating the radiated infrared light and making it into the sound signal by a receiver part. CONSTITUTION:The equipment is composed of a main body part provided at a vehicle and fitted at a car body side and a receiver part 5 at a crew side. The main body modulates infrared light beams corresponding to a sound signal, a transmitting part 4 to radiate it to the space in a vehicle room is provided, and a receiver part 5 photodetects the infrared light radiated from the main body part, demodulates it, makes it into a sound signal and the acoustic reproduction is executed. The receiver part 5 receives the light beams with a photodiode 5a, selects it with a tuning circuit 5b, demodulates it to the sound signal with a demodulator 5c, amplifies it with an amplifier 5d and drives an earphone 5e. Into a case 5f, the tuning circuit 5b and a subsequent circuit part are stored. Thus, the favorite contents of respective persons can be heared without the restriction sense of an action by a lead wire, etc., and comfortably in the same room. |
