SPEED MEASURING INSTRUMENT AND SPEEDING VIOLATION VEHICLE REGULATORY SYSTEM

摘要

PROBLEM TO BE SOLVED: To accurately measure the traveling speed of a target vehicle from a vehicle traveling in parallel by irradiating a light beam to the traveling object vehicle with an optical range finder, and measuring the traveling time from the change quantity of the ranging data per unit time. SOLUTION: This speed measuring instrument with an optical range finder is provided on a speed monitoring/recording device 2 of a monitoring vehicle 1, and toward a travel lane is irradiated obliquely with a light beam 20 in advance. When the tip of an object vehicle 3 enters a position A, the tip of the light beam 20 is reflected, and the optical range finder outputs the range L1 of range information. Upon receiving it, a counter starts the measurement of the predetermined time T. The range information becomes shorter, from L1 to L2 until the vehicle 3 further travels and its tip reaches a position B. When the vehicle 3 goes beyond the position B, the light beam 20 is reflected on the side face of the vehicle 3, and the range is kept unchanged at L2. When the vehicle 3 travels further, the light beam 20 is no longer shielded by the vehicle 3, and a far range is shown just like no traveling vehicle exists. An arithmetic circuit divides a range change quantity L' during the time T, by the time T, to calculate the traveling speed of the vehicle 3.