| 摘要 |
PURPOSE:To convert the directivity of transmitted data, by providing a lens device capable of changing a focal point to the front face of a light source for data transmission. CONSTITUTION:When the transmission data from a terminal IN is at logic 1, a transistor(TR) 1 turns on, a current flows to an infrared-ray emitting diode D to emit it. The infrared-ray lighted from the diode D is transmitted to the outside through a lens device LA. When the data of logic 0 level is inputted to the terminal IN, the TR1 is turned off, no current flows to the diode D, which is not emitted. The lens L is fixed to a movable lens barrel P1, and the P1 is inserted slidably toward f1 or f2 of a fixed lens barrel P2 fixed to the front face of the light emitting diode D. In moving the lens L toward, the f1, the infrared ray is emitted in the range of B and the directivity is spread. In moving the lens L toward the f2, the infrared-ray is emitted in the range A and the directivity is narrowed. |
