SU1571482A1 - Apparatus for detecting defects of cloth - Google Patents

Abstract

The invention relates to textile engineering and can be used to control any webs, paper, textiles, as well as other materials in the related industries. The aim of the invention is to improve the speed of the device for detecting defects. The device containing the source of light, the system of forming a parallel beam of light and its deflection, two offset from each other in the plane of the textile web of a group of mutually perpendicular translucent mirrors, a corner reflector and a receiving device, additionally introduced a second corner reflector located offset the direction of movement of the canvas. This increases the size of the light spot in the direction of the web, which, in turn, increases the speed of movement of the material, limited by the size of this light spot. 1 il.

Description

The invention relates to textile engineering and can be used to control any webs, paper, textiles, and other materials in the related industries.

The purpose of the invention is to increase speed.

The drawing shows the device, the overall appearance.

A device for detecting defects in a web contains a laser 1, a collimator 2, reflective flat mirrors 3 and 4, a rotating mirror drum 5, a parabolic reflecting mirror 6, an angle mirror 7, a group of translucent mirrors 8 and 9 arranged to the plane of the web, respectively, at an angle of 45 ° and p 45 ° (Fig. 1), an angle mirror 10. The device also includes cylindrical lenses 11, 12 and a unit of photodetectors consisting of light guides 13c fixed by photodetectors 14 at their ends. The photodetectors are located under the web 15 against The corresponding mirror is 8 and 9.

The device works as follows.

The luminous flux generated by the laser 1. passes through the collimator 2 and reflected from the mirror 3, falls on one of the faces of the mirror drum 5 and reflected from it, the mirror 4 and the parabolic reflecting mirror 6. sequentially passes through a group of semi-transparent mirrors 8 and falls on the corner mirror 7. Reflected from the angle mirror 7, the stream of light sequentially passes through

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The panel of the translucent mirrors 9 falls down and the first face of the corner mirror 10, mounted against the corner mirror 7 with some displacement in the direction of the web movement. Due to the presence of this displacement, the beam of light, reflected from the second face of the corner mirror 10, re-incident on the group of mirrors 9, while passing parallel to the first beam at some distance from it. Similarly, other rays will be formed, the distances between which are determined by the relative displacement of the corner mirrors. In this way, light spots stretched along its direction are formed on the controlled web. Textile cloths are monitored across the entire width by rotating the mirror drum 5. In this case, each extended light spot falling on the material being monitored, reciprocates, and the direction of movement of these spots in each of the groups of semi-transparent mirrors at any time. mutually opposite. The increase in the speed of viewing the web in the proposed device in comparison with the known proportional to the length of the light spot on the controlled material and can be calculated by the following formula

K -, VCk -Const,

L-2

where K is the ratio of the speed of the web in the proposed device to the speed of the web in the known;

, is the length of the extended and usual light spot;

VCK is the scanning speed of the light spots (rotational speed of the mirror drum).

The light fluxes that passed through the material under test 15, through corresponding cylindrical lenses 11, 12, are directed to the lateral surface of the respective optical fibers 13 and then propagate along these optical fibers to the photodetectors 14. The physical principle of light propagation in the optical fiber is based on the complete internal reflection of the radiation flux.

on the border of two media with different refractive indices.

; When producing a defect-free web, the change in the amount of luminous flux reaching the photodetector 14 is due only to the unevenness of the web 15 in density. When a defect appears on the web 15, for example, in the form of a discharged column, the magnitude of the luminous flux transmitted through the web increases. At the moment of passage through this section of the light flux, an electrical impulse arises at the output of the corresponding photodetector 14, which, after

appropriate reinforcement and treatment is used to fix this defect.

When using a new-element - the second corner mirror - significantly increases the noise immunity due to

shifting the spectrum of the useful signal to lower frequencies. This is due to the fact that with fixed web speeds, the scanning speed can be significantly reduced.

light spots.

Claims (1)

Invention Formula Defect Detection Device canvases containing a light source and successively one after another a system of forming a parallel light beam and its deflection, the first system of translucent mirrors, a corner reflector, a second system of translucent mirrors mutually perpendicular to the first system of mirrors, located offset from the first system of mirrors in the plane of the textile web and a receiving device, characterized in that, in order to improve speed, the device additionally comprises along the second beam system the mirrors are the second corner reflector located offset from the first corner reflector in the direction of the web motion, while the amount of displacement is not greater than the maximum size of the image on the web in the direction of its motion. 15 p and