CN217277931U

CN217277931U - Deformed defect grid imaging structure

Info

Publication number: CN217277931U
Application number: CN202221018034.XU
Authority: CN
Inventors: 和江镇; 王岩松; 方志斌; 王郑; 孔维增; 秦学文
Original assignee: Focusight Technology Co Ltd
Current assignee: Focusight Technology Co Ltd
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-08-23
Anticipated expiration: 2032-04-29

Abstract

The utility model relates to a deformation defect grid imaging structure, which comprises a sheet material to be measured, an area-array camera component and a grid light source; an included angle between the light-emitting surface of the grid light source and an imaging point of the sheet material to be detected in the flowing direction of the sheet material to be detected is 55-62 degrees, and the distance between the central point of the light-emitting surface of the grid light source and the imaging point of the sheet material to be detected is 200-350 mm; the included angle between the central extension line of the area array camera assembly and the imaging point of the sheet stock to be detected in the non-flowing direction of the sheet stock to be detected is 55-62 degrees, and the distance between the lens central point of the area array camera assembly and the imaging point of the sheet stock to be detected is 400-500 mm. The utility model discloses a grid station imaging mode can detect the defect that the degree of difficulty is high on original check out test set, including the impression of low degree, mild indentation etc. will be higher than on the detectability with conventional grating formation of image on the formation of image.

Description

Deformed defect grid imaging structure

Technical Field

The utility model belongs to the technical field of the visual inspection technique and specifically relates to a deformation defect grid imaging structure.

Background

At present, a grating station is generally adopted for detecting the surface defects of the reflective sheet materials; the grating station consists of a coaxial light source, a grating, a line scanning camera, a lens, a bracket and a transmission mechanism.

During detection, a sheet material to be detected is placed on the air suction belt, a coaxial light source irradiates the surface of the sheet material through a grating to form reflected light in the opposite direction, and the reflected light is imaged by a line scanning camera; when the surface of the sheet material has deformation defects, the grating can be distorted, and the defects of the sheet material can be detected by detecting the distortion of the grating stripes.

However, as the grating stations are subjected to one-dimensional detection, the defects that the reflection is affected only in the flow channel direction are detected, the sensitivity to the defects is low, if the deformation defect of the sheet material is smaller than the interval of the gratings or the transverse width of the sheet material is smaller than the interval of the two gratings, the deformation of the imaging line is very unobvious, and the defects are missed to be detected; in addition, the position of the belt hole of the air suction belt has the phenomenon of deformation, so that the false detection of the optical grating is serious.

Meanwhile, aiming at the strip defects, if the defects are parallel to the flow channel direction or completely perpendicular to the flow channel direction, imaging deformation is not obvious, and missing detection is easy. The small plano-concave defects only have a small amount of line segment broken lines in the imaging of the grating, and the broken line shape represented by uneven edges of the sheet materials is very similar, so that the over-inspection is caused, and the yield is reduced.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is: the deformation defect grid imaging structure is provided, and deformation defects on the surface of a reflective sheet material, such as point-like stamping, slight indentation and the like, can be detected.

The utility model provides a technical scheme that its technical problem adopted is: a deformation defect grid imaging structure comprises a sheet stock to be detected, which is placed on an air suction belt; an area-array camera component and a grid light source are respectively arranged above the sheet material to be detected; the area array camera assembly and the grid light source are respectively connected with the PLC; the sheet stock to be detected is conveyed to an imaging and image-picking position through an air suction belt, the PLC sends an image-picking trigger signal to the area array camera assembly, and simultaneously triggers a grid light source to light and pick images; the included angle between the light-emitting surface of the grid light source and the imaging point of the sheet material to be detected in the flowing direction of the sheet material to be detected is 55-62 degrees, and the distance between the central point of the light-emitting surface of the grid light source and the imaging point of the sheet material to be detected is 200-350 mm; the included angle between the central extension line of the area array camera assembly and the imaging point of the sheet stock to be detected in the non-flow direction of the sheet stock to be detected is 55-62 degrees, and the distance between the lens central point of the area array camera assembly and the imaging point of the sheet stock to be detected is 400-500 mm.

Furthermore, the grid light source of the utility model comprises a bottom plate and a shell covering the bottom plate, wherein a PCB is arranged in the shell, and LED lamp beads are uniformly distributed on the PCB; a diffusion plate is arranged in the shell and above the LED lamp beads; the glass plate is arranged on the shell, and a checkerboard structure is carved on the surface of the glass plate through laser; the bottom plate is provided with a containing cavity, and the containing cavity is connected with a water-cooling joint; a water tank sealing plate is arranged below the bottom plate; the size of the shell is 350 mm-450 mm; the size of the grid glass plate is 0.5mm x 0.5 mm.

Still further say, LED lamp pearl be the matrix and arrange, LED lamp pearl luminance is 50w lx.

Still further, the area-array camera module of the present invention has 2500 ten thousand imaging pixels.

The beneficial effects of the utility model are that, solved the defect that exists among the background art, adopted grid station imaging mode, can detect the defect that detects the degree of difficulty height on original check out test set, including the impression of low degree, slight indentation, the indentation etc. of curling, higher in the detectability than with conventional grating formation of image on the formation of image.

Drawings

Fig. 1 is a schematic optical path diagram of an imaging structure of the present invention;

fig. 2 is a schematic structural diagram of the grid light source of the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 2 at R;

in the figure: 1. sheet stock to be detected; 2. an area-array camera assembly; 3. a grid light source; 31. a base plate; 32. a housing; 33. a PCB board; 34. a diffusion plate; 35. a glass plate; 36. a water-cooled joint; 37. a water tank sealing plate.

Detailed Description

The invention will now be described in further detail with reference to the drawings and preferred embodiments. These drawings are simplified schematic drawings and illustrate the basic structure of the present invention only in a schematic manner, and thus show only the components related to the present invention.

A deformation defect grid imaging structure as shown in fig. 1, which is used for detecting deformation defects on the surface of a reflective sheet material, such as point-like stamping, light indentation, curl los indentation and the like; comprises a sheet stock 1 to be tested which is arranged on an air suction belt; an area-array camera component 2 and a grid light source 3 are respectively arranged above the sheet material 1 to be detected; an included angle alpha between the light-emitting surface of the grid light source 3 and an imaging point of the sheet material to be detected in the flowing direction of the sheet material to be detected is 60 degrees, and a distance h1 between the central point of the light-emitting surface of the grid light source 3 and the imaging point of the sheet material to be detected is 200 mm; the included angle beta between the central extension line of the area array camera assembly 2 and the imaging point of the sheet stock to be detected in the non-flow direction of the sheet stock to be detected is 60 degrees, and the distance h2 between the lens central point of the area array camera assembly 2 and the imaging point of the sheet stock to be detected is 400 mm.

As shown in fig. 2-3, the grid light source 3 includes a bottom plate 31 and a housing 32, the housing 32 is provided with a PCB 33 therein, LED beads are uniformly arranged in a matrix on the PCB 33, and the brightness of the LED beads is 50 lx. A diffusion plate 34 is arranged in the shell 32 and above the LED lamp beads, and a grid glass plate 35 is arranged on the shell; the grid glass plate is high-performance optical glass with laser engraved checkerboard patterns on the surface, and the size of the shell is 350mm x 450 mm; the size of the grid glass plate is 0.5mm x 0.5 mm. The light source adopts the stroboscopic to arouse and lights, and the advantage is that calorific capacity is little, and luminance can reach brightest peak value 50wlx, and the bottom plate is the aluminum hull, has and holds the chamber, the chamber be connected with water-cooling joint 36, the below of bottom plate is provided with basin closing plate 37 for the light source is from taking water-cooling heat dissipation, can guarantee long-time job stabilization nature and long-life. The shell is the heat dissipation aluminium material, and the shell side has a plurality of louvres.

The area array camera component 2 and the grid light source 3 are respectively connected with a PLC controller; the imaging pixel of the area array camera component 2 is 2500 ten thousand; the sheet stock to be detected is conveyed to an imaging and image-picking position through an air suction belt, the PLC sends an image-picking trigger signal to the area array camera assembly, and simultaneously triggers a grid light source to light and pick images; after the picture is picked, the pictures are sent to an industrial personal computer through a network cable, defects are extracted through an algorithm, interference items are shielded, and defect signals or good product models are output. The algorithm adopts supervised learning to construct a training integration of the confirmed NG sample and the OK sample, can accurately define the defects according to the defect types, and can detect the corresponding defects more accurately through different forms compared with the prior traditional algorithm.

The utility model utilizes the mirror reflection principle, when the surface of the sheet material is flat and has no deformation defect, the light can enter the lens for molding according to the angle reflection which is the same as the incident angle; when the surface of the sheet is embossed, the reflection direction of the light at the defect is not the same as the incident angle, but is deflected, and the image of the area is distorted and blurred. Defects may be detected by a visual inspection algorithm.

The utility model discloses a grid light source 3 then have following advantage:

1. the lamp beads are uniformly distributed: matrix arrangement; the brightness of the high-brightness LED lamp beads which uniformly emit light can reach 50 wlx;

2. the outer part of the diffusion plate is provided with a diffusion plate with good light transmission and divergence;

3. the outermost part is provided with a grid glass plate processed with high precision;

and moreover, an included angle of 60 degrees is formed between the light source and the flowing direction of the sheet stock to be detected, and an included angle of 6 degrees is not formed between the light source and the non-flowing direction, because the distortion caused by the imaging mode is small, and the defect imaging effect is more obvious.

In addition, the grid station is used for two-dimensional imaging detection, the problem that the imaging sensitivity of the defects in all directions is inconsistent in a one-dimensional system does not exist, in contrast, the sensitivity of the grid station to the defects in all directions is very high, if the radius of the defect is smaller than the size of the grid, the size in all directions is smaller than the size of the grid and is just right in the center of the grid, and the grid can be missed for detection.

The utility model discloses set up negative pressure display device below the belt that induced drafts, can guarantee that wind-force is even to this guarantees that the sheet stock can be adsorbed on the runner and levels. And under the condition that the edge of the sheet material is uneven and the air suction belt cannot be sucked flat, the grid imaging can still be kept clear, only the distance of each grid is shortened, but the edge blurring phenomenon of typical defects cannot occur, the algorithm can still extract the real under-point characteristics and ignore the grid density change, and therefore the phenomenon that the edge of the sheet material with large radian is bent and mistakenly detected as the deformation defect is avoided.

For the strip shape, whether the strip shape is vertical or parallel to the flow channel direction, the grid can obviously generate image deformation, so that the image deformation is detected by an algorithm.

Meanwhile, the small plano-concave defect presents very obvious spiral imaging on the grid and is easy to detect.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A deformed defect grid imaging structure, comprising: comprises a sheet stock to be tested which is placed on an air suction belt; an area-array camera component and a grid light source are respectively arranged above the sheet material to be detected; the area array camera assembly and the grid light source are respectively connected with the PLC; the sheet material to be detected is conveyed to an imaging and image-picking position through an air suction belt, the PLC sends an image-picking trigger signal to the area array camera assembly, and simultaneously triggers the grid light source to light up, so that the image is collected;

the included angle between the light-emitting surface of the grid light source and the imaging point of the sheet material to be detected in the flowing direction of the sheet material to be detected is 55-62 degrees, and the distance between the central point of the light-emitting surface of the grid light source and the imaging point of the sheet material to be detected is 200-350 mm; the included angle between the center extension line of the area array camera assembly and the imaging point of the sheet material to be detected in the non-flow direction of the sheet material to be detected is 55-62 degrees, and the distance between the lens center point of the area array camera assembly and the imaging point of the sheet material to be detected is 400-500 mm.

2. The deformed defect grid imaging structure of claim 1, wherein: the grid light source comprises a bottom plate and a shell covering the bottom plate, a PCB is arranged in the shell, and LED lamp beads are uniformly distributed on the PCB; a diffusion plate is arranged in the shell and above the LED lamp beads; the glass plate is arranged on the shell, and a checkerboard structure is carved on the surface of the glass plate through laser.

3. The deformed defect grid imaging structure of claim 2, wherein: LED lamp pearl be the matrix and arrange, LED lamp pearl luminance is 50 wlx.

4. The deformed defect grid imaging structure of claim 2, wherein: the size of the shell is 350 mm-450 mm; the size of the glass plate is 0.5 mm.

5. The deformed defect grid imaging structure of claim 2, wherein: the bottom plate is provided with a containing cavity, and the containing cavity is connected with a water-cooling joint; a water tank sealing plate is arranged below the bottom plate.

6. The deformed defect grid imaging structure of claim 2, wherein: the imaging pixel of the area-array camera component is 2500 tens of thousands.