| 摘要 |
A stereophonic audio system including a device for providing a stereophonic signal, such as an audio receiver. An infrared transmitter connected to the receiver converts the audio signal to an infrared signal to be radiated throughout a signal area. Within this signal area is disposed a pair of loudspeakers, each selecting a separate portion of the infrared signal, converting that one portion of the infrared signal to an audible sound signal, and radiating the sound throughout a listening area. Each loudspeaker includes a filter for selecting the one infrared signal which applies to it. The transmitter includes a plug engageable with a headphone jack of the receiver for electrically connecting the transmitter to the receiver and an infrared diode array for radiating the signal within the signal area. Each of the loudspeakers includes a photodiode arrangement for receiving the infrared light carrying the transmission signal from the transmitter and passing it to the respective filter, an amplifier for amplifying the signal, and speaker elements for receiving the signal from the amplifier and converting it to sound signals, for radiating in the listening area. To avoid the necessity of any wires leading to the loudspeakers, each is battery operated, and includes a power saver circuit to reduce power loss whenever no signal is received from the transmitter. The transmitter also includes a power saver circuit to disable the diode array whenever it receives no signal from the receiver. |
