SU1721482A1 - Device for flaw detection of light guides - Google Patents

Abstract

The invention relates to a control and measuring technique. The goal is to improve the reliability of flaw detection and increase its efficiency. For this, the proposed device contains lighting and recording systems. The lighting system includes a light source 1, a condenser 3. a swiveling mirror 4 and a focusing lens 5. The last two elements have holes in their centers, the axes of which coincide with the axis of the guides of the light guide being investigated 6. By means of a lighting system, radiation is introduced into the light guide through its side surface . The radiation scattered by defects falls on three micro-lenses 7. located at 120 ° & with respect to the axis of the guides, and through the optical fiber converters 8 and the forming optical system 9 and 10 is transmitted to the array photodetector. Three projections of the portion of the light guide 6 are analyzed by the information processing unit. 2 Il. cl

Description

The invention relates to measuring technique, in particular to devices for non-destructive testing of materials, and can be used in the electronic, optomechanical and chemical industries.

A device is known for determining the location of defects in optical fibers, which contains a light source that provides input of radiation into a controlled optical fiber through its input end face, and a recording system containing sequentially located input reel, four drums enclosed in a lightproof casing and installed in pairs in two mutually perpendicular planes , and the output reel, Each of the drums is covered with an electronographic layer and is equipped with a toroidal reflector, an electronic marker, an electronic congestion and apparatus for removal of charge.

The disadvantages of this device are: the inability to control the optical fibers in the manufacturing process, the impossibility of defectoscopy of rigid optical fibers, the difficulties associated with determining the geometric dimensions of defects, and their classification.

Closest to the invention is a device for inspection of optical fibers, containing guides for the studied optical fiber, a lighting system. including a light source, a condenser and rotary mirrors, as well as a recording system that includes three micro-lenses located 120 ° relative to the axis of the guides of the investigated fiber. Micro lenses are optically coupled to a photodetector, which is connected to an electronic signal processing unit.

The recording part in this device consists of two identical parts when monitoring the optical fibers in the air and in the immersion liquid.

The radiation is formed in the form of two three-angle beams, which simultaneously irradiate two parts of the object, one of which is located in the immersion liquid with a refractive index close to the material of the object. In the near zone 7 shadow patterns are formed, according to the position of the boundaries of which the cross-sectional shape of the object is estimated.

The known device does not allow to identify all types of defects that are possible in the optical fibers, which reduces the reliability of flaw detection and, in addition, measurements in the immersion fluid do not allow the optical fibers to be monitored during their manufacture.

The aim of the invention is to increase the reliability of flaw detection and increase its efficiency.

Figure 1 presents a diagram of a device; figure 2 is a structural diagram of a signal processing unit.

Radiation from a halogen metal lamp 1 using a spherical reflector 2, a condenser 3, a swivel mirror 4, and a focusing lens 5 located in a metal casing is introduced into the drawn fiber 6 through its side surface in the immediate vicinity of the control point. Mirror 4 and lens 5 are cut in half and have holes in the center for the fiber. The radiation emerging from the fiber 6 is recorded by a recording system consisting of three micro-lenses 7 located 120 ° in the plane of the perpendicular axis of the fiber, three optical converters 8 and two short-focus lenses 9 and 10. Micro-lenses 7 form an image of three projections of the optical fiber 6 at the ends of the optical fiber converters 8 From the other ends of the converters assembled into a bundle, the image of the projections using the forming optical system 9 and 10 is focused on the working surface of the television camera 11 mat photodetector. The video signal from the camera 11 is supplied to the video monitoring device 12 and in parallel to the block 13 for processing and inputting a television signal into the microcomputer 14.

Micro lenses 7 are fixed on the base, which can be moved in two mutually perpendicular directions using microscrews. On the base there is a handle, by rotation of which the micro-lenses and the light source housing are removed from the working area, freeing the hole for pulling the light guide and refueling it into the pulling mechanism. In this case, the halves of the rotary mirror 4 and the focusing lens 5 are moved apart.

The diagram of the processing unit and the input of a television signal in a microcomputer Electronics-60 "(figure 2) consists of a clock selector 15, a shaper 16 time intervals, a filter 17, a threshold device 18, a time selector 19 and a device 20 for digital processing and data input into a microcomputer,

The video signal from the television camera enters the sync-selector 15, where frame and line sync pulses are supplied from the input to the shaper 16 time intervals, which generates pulses of the line number and pulses of line selection. Analog video signal processing is carried out using a filter 17, a threshold device 18 and a time selector 19. These nodes perform binary video signal processing and present the information of a television line in the form of logical levels of O or 1. Filter 17 is used to suppress the high-frequency components of the clock frequency of a television camera.

The extracted signal is fed to a threshold device 18, on the comparators of which pulses X, Y, Z are formed, which correspond to the diameter of the fiber, the distance from the boundary of the projection of the fiber to the defect, and the width of the defect. The threshold levels of the comparators are controlled by potentiometers. From the output of the comparators, an information signal in the form of rectangular pulses X, Y, Z enters the time selector 19, which selects three working lines that carry information about the three projections of the fiber, at the beginning, middle, and end of each half-frame of the image using the line selection pulses coming from shaper 16 time intervals. From the output of the selector 19, information signals X, Y, Z are fed to the digital processing and input device 20, which is structurally combined with the standard I5 interface. This device is designed for digital processing and input into the microcomputer Electronics-60 '' of the three coordinates X, Y, Z formed in the time interval of one television line. The formation of signals X, Y, Z is interconnected and occurs during each odd television line. In this case, the first horizontal pulse resets the counters of the digital processing unit, and as signals X, Y, Z arrive, they are filled with pulses from the high-frequency generator. The formation of the X coordinate ends last. By cutting this pulse, a Strobe signal is generated, which records the counter data in the form of sixteen-digit binary numbers in the corresponding buffer registers. After a program survey, the data of these registers are entered into the memory of the microcomputer and the digital processing unit is ready for the next cycle of work.

The device operates as follows.

By turning the handle on the base for attaching micro-lenses 7, micro-lenses and a source of 1 light source are removed from the working space, the light guide 6 is passed through the hole and inserted into the pulling mechanism, micro-lenses 7 and the light source 1 are put into working position, the light source 1, television the camera 11 and the video monitoring device 12, with two microscrews on the base, adjust the device so that on the screen of the video monitoring monitor there is a clear image of three projections drawn from etovoda located one above the other, include a microcomputer, run programs, and on-screen keyboard settings gaining defects that need to be discarded.

Claims (1)

Claim A device for defectoscopy of optical fibers, comprising guides for the optical fiber, an illumination system including a sequentially located light source, a condenser and a rotary mirror, as well as a recording system including three micro-lenses located 120 ° relative to the axis of the guides, optically coupled to a photodetector electrically connected with a signal processing unit, characterized in that, in order to increase the reliability and efficiency of flaw detection, the output of the lighting system The focusing lens is updated, and three fiber-optic converters are added to the recording system, optically coupled by the input ends with micro-lenses, and a forming optical system, coupled to the photodetector, while the optical axis of the light source and capacitor is perpendicular to the axis of the guides, the focusing lens and the swivel mirror are made with holes in their centers, the axes of which coincide with the axis of the guides, the output ends of the fiber-optic converters are connected into a bundle and combined with the object plate knock-forming optical system and the photodetector matrix is formed.