ACOUSTIC ANGLE SENSOR Russian patent published in 1995 - IPC

FIELD: measurement technology. SUBSTANCE: angle sensor has laser 1, acoustooptic element 3 connected to high-frequency voltage source 5, mirror mounted on an object to be measured, objective lens 7, photodetector 8 located in the focal plane of the objective lens and coupled with a signal converting unit. The device is characterized in that the acoustooptic element is situated in the path of beams reflected from the mirror at an angle to provide Bragg conditions within the whole range of measurements and a transverse dimension of the element is determined from expression l = 2λ/πϕ_Dsin θ_o where ϕ_D is an angle of natural divergence of laser beams, θ_o is an incidence angle of beams onto the element at which passed beams are in parallel with the principal optic axis of the objective lens, λ is a radiation wave length. The device furthermore has a modulator in the form of a linear voltage generator connected to the high-frequency voltage source and which output is through a differentiating stage is connected to one of the inputs of a flip-flop being a component of the signal conversion unit. The other input of the flip-flop is connected to a pulse amplifier for multiplying pulses from the photodetector. Such construction of the sensor provides widened view zone and enhanced measurement accuracy due to the fact that Bragg conditions are satisfied precisely within the whole measurement range at different values of Bragg angles and to provide an operation of sensor in a pulsed operating mode of the electronic unit at large thickness of the acoustic element. EFFECT: enhanced accuracy and widened measurement range. 3 dwg