SHORT-RANGE WIRELESS AUDIO COMMUNICATIONS USING INDUCTION

摘要

A communications system includes portable stereo headphones having an inductive receiver and a portable audio source. The source generates a magnetic field based on a modulated audio signal. The inductive receiver includes one or more transducers and associated electronics for receiving the magnetic field and recovering the audio signal. The portable source (e.g., a portable compact disc or tape player, or a portable radio) modulates the audio signal and then generates the magnetic field using one or more transducers and associated electronics. The audio signal typically is music and/or voice recorded on a magnetic tape or on a compact disc. The headphones can be provided in various configurations including an arrangement worn over the head with speakers that cover or partially cover the ears of the user or an arrangement of the concha type in which the speaker fits into one or both of the user's ears without a strap across the head. In the strap-across-the-head configuration, the inductive receiver can be disposed in or on the strap, or in or on one of the speakers. In the concha type configuration, the inductive receiver can be encapsulated into the small device that gets inserted into the user's ear(s). Because only a relatively small amount of power is required to receive and generate magnetic induction fields, the power sources in the headphones and the portable source needed to power the inductive receiver and to generate the magnetic field, respectively, are relatively small in size and weight.