SU922507A1 - Device for measuring article geometric dimensions - Google Patents

Description

(5) DEVICE FOR MEASURING GEOMETRIC

PRODUCT SIZES

The invention relates to a measuring technique and can be used to measure the geometric dimensions of products. A device for measuring parameters is known, which contains a scanistor, a sawtooth voltage generator, two adders and two load resistances Ci. A disadvantage of the device is high sensitivity to interference due to the type of sweep voltage and the pass-through capacity of the scanstor, as well as the large dependence of the output signal on temperature. lecturer-emitter junction. The closest to the proposed technical essence and the achieved result is a device for measuring the geometrical dimensions of the product, comprising an optical system, a scanner and a video signal extraction unit, an offset source and a linear sweep unit. the latter are respectively connected to the dividing bus of the scanistor 2}. The drawback of the device is the instability of the resolution, in particular, due to a change in the collector-emitter junction temperature of the scanner caused, for example, by a change in the ambient temperature, by the action of light and infrared sources on the scanstor. The purpose of the invention is to stabilize the resolution of the device. The goal is achieved by the fact that it is equipped with a thermal converter connected to the scanner, the outputs of which are connected to the displacement source and to the linear sweep former, and the latter are controlled. The drawing shows the block diagram of the device. The device consists of an optical syrtem 1, scanstor 2, having

a three-layer structure, a block 3 for extracting a video signal connected to the scanner 2, an offset source 4 and a linear sweep former 5 controlled by a transducer and a thermal converter 6 connected to the latter and to the scanner 2 case, and a heat-conducting material 7 through which the thermal converter is connected 6, and the scanistor 2 and the measured product 8.

The measured article 8 is projected by the optical system 1 onto the photosensitive layer of the scanner 2, on which the light image is transformed, the sweep of this image is performed by an equipotential zero point resulting from the algebraic addition of the instantaneous voltages taken from the linear sweep 5 and the bias source , made controllable, the initial voltage of which is set in advance. When the temperature of the collector-emitter junction of the scanner 2 changes, the thermal converter 6 will react to this change, its output will affect the input of the bias source t, will change the voltage on the dividing bus of the scanner 2 so that the resolution of the scanner presented

- EO

In the form of N

De

where E (J is the bias voltage amplitude;

Л Е - the aperture of the scanning boundary in volt terms, will be a constant value. At the same time, the signal from the thermal converter

6, affecting the input of the linear sweep generator 5, changes the amplitude value of the sweep voltage to the magnitude of the voltage on the dividing bus of the scanor 2, since

This is necessary for the equipotential zero point to pass through the entire photosensitive layer of the scanistor 2.

Claims (2)

1. Author's certificate of the USSR 551A98, cl. G 01 B 7/02, 1977. 2. USSR author's certificate ff 381868, cl. G 01 B 7/02, 1973 (prototype).