| 摘要 |
<p>Described is a portable directional receiver (fig. 2). It comprises a non-visual communicator, a self-contained source of electrical energy, a detector (D1) for receiving a sensed continuous frequency modulated infrared signal, and electronics (Q2, Q3, Q4) converting the sensed signal into intelligible non-visual communication emanating from the communicator both in the presence and in the absence of an ambient background of light energy, such as sunlight. The device is adapted for use by the visually impaired in finding desired locations from which suitable modulated infrared signals are continuously emitted.</p> |
