| 摘要 |
PURPOSE:To eliminate a false reflection pulse and to enable measuring of even a short distance, by a method wherein a threshold, amplitude-discriminating a reflection pulse, is converted as a voltage whose magnitude varies depending on a time resulting from the start which is conducted by means of an oscillating pulse of laser light, and the voltage is caused to differ each time laser light is emitted. CONSTITUTION:Laser light of a Q switch oscillator 1 is focused by an optical system 2 and emitted toward a target, and a part thereof starts a monostable multivibrator 5 and a pulse counting part 17 through a detector 3, amplifier 4. Reflecting light from the target is recieved by an optical system 6, it is detected by a photomultiplier 7, and after amplified 8, it is added to a monostable multivibrator 14. The multivibrator 14 is triggered by a stop pulse exceeding a threshold trigger level, it is polarity inversed by an inverter 16, and is added to the counting part 17 to display a distance to the target. This changes values of a capacitor 15 and a bias resistance 13 each time a transmitting pulse is transmitted, which results in erasing a false reflecting pulse and in enabling to perform a measurement of a distance of and a detection of even a target located at a short distance. |
