CN204255308U - A kind of large area object plane degree pick-up unit - Google Patents

Abstract

A large-area object flatness detection device is provided, including a base (1), a hydraulic device (2), a workbench (4), a dust cover (5), a vertical support plate (6) and a (5) Measuring mechanism. The measuring mechanism includes a rod-shaped support frame (9), a grating support (16), a grating (7), a displacement table (8), a slider (12) and a load support (15), and the load support (15) is loaded with horizontal The moving CCD camera (14) and the light source (10), the optical center of the CCD camera (14) and the light source (10) are located in the same horizontal plane, and the CCD camera (14) and the light source (10) face the grating (7) to take pictures and emit light respectively , the control device is connected with the displacement platform (8) and controls its movement up and down. The large-area object flatness detection device of the utility model can quickly and accurately measure the three-dimensional shape of a large plane, and has low cost and simple operation.

Description

A large-area object flatness detection device

technical field

The technology of the utility model relates to the field of optical detection, in particular to a non-contact device for quickly and accurately measuring the flatness of large-area objects, in particular to a full-field measuring device based on shadow mole technology.

Background technique

At present, the widely used flatness detection method is to take a certain number of sample points on the surface of the object to be detected, measure the height of these sample points, and then use a specific formula to calculate, and use the calculation results to characterize the flatness of a surface. This measurement method, due to point-by-point measurement, cannot accurately reflect the flatness of a surface when the selected measurement sample points are few. However, when there are many sample points to be measured, the detection speed is bound to be affected. There are also some full-field measuring instruments using other methods on the market, but they are expensive and have a small measurement area, which limits their application in industrial testing.

Utility model content

The purpose of this utility model is to overcome the above-mentioned shortcoming of existing equipment. In order to realize the combination of measurement accuracy and measurement speed of large-area objects, the utility model provides a novel flatness detection device. The device can be applied to flatness measurement of large-area panels such as mobile phone panels, notebook computer panels, and tablet computer panels. It can not only accurately reflect the three-dimensional shape of large-area panels, but also has fast measurement speed, low price, simple operation, and occupies The area is small, the surface of the workpiece is not damaged, and the requirements for the working environment are not high, which can meet the requirements of online inspection for large-scale assembly line production.

The large-area object flatness detection device of the present utility model comprises

The base 1 acts as a stable support, and its upper and lower surfaces are horizontally parallel to each other;

The hydraulic device 2 is stably supported on the base 1, and its upper and lower surfaces are horizontally parallel to each other;

The workbench 4 is located on the hydraulic device 2 and moves up and down under the control of the hydraulic device 2, and its upper and lower surfaces are parallel to each other horizontally;

Dustproof cover 5, it is casing, and the bottom is open, and for ease of installation, there is a gap at the place where it contacts rod-shaped support frame 9 at the back;

The vertical support plate 6 is located on the base 1, the rear side of the hydraulic device 2, the workbench 4 and the dust cover 5, and is fixedly connected with the base 1, the hydraulic device 2 and the dust cover 5 respectively;

It is characterized in that it also includes a measuring mechanism that is integrally located in the dust cover 5, and the measuring mechanism includes

Rod-shaped support frame 9, which is vertically fixed on the front side of support plate 6;

The rest of the components from bottom to top are

Grating bracket 16, which is installed horizontally, is fixedly connected with displacement table 8;

grating 7, which is installed horizontally on the grating support 16;

The displacement table 8 is fixedly connected with the rod-shaped support frame 9, and is fixedly connected with the grating support 16, and is used to control the grating 7 to move up and down;

Slider 12, it can slide up and down along support frame 9;

Load bracket (15), it is fixedly connected with slide block 12, is loaded with horizontally movable CCD camera 14 and light source 10 on it, wherein CCD camera 14 faces grating 7 to take pictures, light source 10 faces grating 7 to emit light, and the light of CCD camera The core 14 and the light source 10 are located in the same horizontal plane;

The control device is connected with the displacement platform 8 and controls its movement up and down.

In one embodiment of the present utility model, the load support (15) is a T-shaped bar placed horizontally, and the slide block 12 is fixedly connected with the rear end of the T-shaped bar. The front end of the T-shaped bar is a section of guide rail, and the T-shaped bar 15 The left and right ends of the front end are respectively equipped with a first slider 11 and a second slider 13, and the first slider 11 and the second slider 13 can slide left and right in the horizontal plane along the guide rail at the front end of the T-shaped bar. CCD camera 14 and light source 10 are respectively fixedly installed on the first slide block 11 and the second slide block 13.

In one embodiment of the utility model, the displacement table 8 adopts a stepping motor that can move up and down;

In one embodiment of the present invention, the large-area object flatness detection device of the present invention further includes several support columns 3 for supporting the workbench 4 .

In a preferred embodiment of the present invention, the number of the supporting columns 3 is four.

In one embodiment of the present invention, a fixture is installed on the workbench 4 for fixing the tested piece.

The large-area object flatness detection device of the utility model can quickly and accurately measure the three-dimensional shape of a large plane, and has low cost and simple operation.

Description of drawings

Figure 1 shows the measurement principle diagram, in the figure, p represents the grating pitch, d represents the vertical distance between the LED light source and the grating, h represents the horizontal distance between the optical center of the CCD camera and the LED line light source, and H represents the distance from the object surface to the grating ;

Fig. 2 shows the overall view of the device, wherein 1. base, 2. hydraulic lifting device, 3. workbench support column, 4. workbench, 5. dust cover, 6. vertical support plate;

Fig. 3 shows the structural diagram of the measuring mechanism, wherein 7. grating and its support, 8. displacement stage, 9. rod support frame, 10. LED line light source, 11. LED light source positioning slider, 12. slider, 13 .CCD positioning slider, 14.CCD camera, 15. Load bracket, 16. Grating bracket.

specific implementation plan

Below in conjunction with accompanying drawing, the utility model is described in further detail.

The utility model realizes flatness detection through the following technical solutions: as shown in Figure 1, a grating is placed on the object to be measured, and when the grating is irradiated with an LED light source, the grating projects a bright and alternate pattern on the surface of the object to be measured. grid line. The grid line is modulated by the three-dimensional topography of the surface of the measured object, resulting in a deformed shadow grid. Due to the overlap between the deformed shadow grating and the reference grating lines, a series of black and white fringes with amplified period are generated, and the fringes contain three-dimensional information of the surface of the object. Phase shifting can be achieved by using a stage to control the grating to move up and down a specific distance. CCD is used to collect fringe images, one is collected for each phase shift, and the phase is shifted 4 times, and the wrapping phase can be obtained through 4 images. Using a computer program to unwrap the phase to obtain the original phase, and then through a certain geometric relationship, the three-dimensional shape of the surface can be obtained.

Figure 2 is an overall view of the device, including a base 1 with a shock-absorbing function. The base 1 can adopt the bottom surface shown in Figure 2, and the top surface is a square platform with a large bottom and a small top, or any other stable base. The shape of the base 1, such as cube, cuboid, cylinder, etc., should be able to stably support the hydraulic device 2 on it. The hydraulic device 2 is used to control the workbench 4 to move up and down, and the hydraulic device 2 is usually in the shape of a square or a cylinder. The workbench 4 is usually a thin square with several support columns 3. The number of support columns 3 is usually 4. The support columns 3 are supported on the hydraulic device 2, and the hydraulic device 2 can control the workbench 4 to move up and down through the support columns 3. . A fixture (not shown) can be installed on the workbench 4, such as a positioning block, or a special fixture made according to the shape of the workpiece, and the fixture is used to fix the position of the workpiece (ie, the measured piece); of course, it is also possible not to install the fixture . According to the thickness of different workpieces, the height of the worktable 4 is controlled by the hydraulic device 2 . In mass production, the thickness of the same kind of workpiece generally does not change much. Generally, it is not necessary to adjust the height of the workbench frequently. It is only necessary to determine the position of the workpiece on the workbench. This is especially suitable for the shape measurement of planar workpieces. Above the workbench 4 is the core part of the device—the measuring mechanism, which is located inside the dust cover 5 . The dustproof cover 5 plays a dustproof effect, and the dustproof cover 5 is a casing with an open bottom, and the dustproof cover 5 is used to include the measuring mechanism.

Among the above-mentioned components, except the workbench 4 and the workbench support column 3, the remaining parts are all fixedly connected with the vertical support plate 6. The internal structure of the measurement mechanism limited by the dust cover 5 is as shown in Figure 3: grating 7 from bottom to top, and the grating 7 is horizontally installed on the grating support 16, and its installation method is well known to those skilled in the art. The grating bracket 16 is fixedly connected with the displacement stage 8 . The displacement platform 8 is connected with the computer and is controlled by it. When controlling the phase shift, a certain number of pulses are given to the stepping motor in the translation platform through a computer program to drive the stepping motor to rotate, and the stepping motor drives the translation platform 8, thereby controlling the grating to move up and down to realize the phase shift. The displacement stage is fixed on the rod-shaped support frame 9 through a fastening device such as a screw rod, and the rod-shaped support frame 9 is fixedly connected with the support plate 6 through a fastening device such as a screw rod. within 5. Above the displacement stage is a slide block 12 installed on the rod-shaped support frame 9. The slide block 12 is fastened on the rod-shaped support frame 9 by a fastening device such as a screw, and the position is generally fixed. During calibration, the screw rod can be loosened to adjust the position of the slide block 12 up and down. A horizontally placed load bracket 15 is fixed on the slider 12, the slider 12 is fixedly connected to the rear end of the T-shaped bar 15, the front end of the T-shaped bar 15 is a guide rail, and the plane where the T-shaped bar 15 is located is the same as the grating 7. parallel to the plane. The left and right two ends of T-shaped bar 15 front ends are equipped with first slide block 11 and second slide block 13 respectively, and first slide block 11 and second slide block 13 all can slide left and right along the guide rail of T-shaped bar front end ( But obviously all can not exceed load support 15 middle parts), the same as slide block 12, first slide block 11 and second slide block 13 are respectively fastened on T bar 15 front ends by fastening device such as screw rod after calibration is finished. Left and right ends. On the second slider 13 at the left end, a CCD camera 14 is fixedly installed by a fastening device such as a screw. The CCD camera 14 is installed vertically, and the lens faces the grating 7. After the screw is loosened, the position of the CCD camera 14 can be slightly moved up and down for fine adjustment. . Below the first slider 11 at the right end (that is, on the side facing the grating 7 ), the LED line light source 10 is fixed and horizontally installed, facing the grating 7 to emit light. The optical centers of the LED line light source 10 and the CCD camera 14 are located in the same horizontal plane. Both the CCD camera 14 and the LED line light source 10 are connected to the corresponding power supply, and the output end of the CCD camera 14 is connected to the computer. When the computer controls the phase shift and the CCD camera 14 acquires four phase images, the three-dimensional topography of the workpiece surface can be obtained. According to different flatness characterization methods, combined with corresponding calculation formulas, the workpiece flatness can be calculated.

The fastening means is not limited to the screw rod, but means known to those skilled in the art can be used, such as screws, bolts, positioning pins.

The following is an example of measuring the flatness of a laptop keyboard to illustrate the operation of the device.

1. First choose the appropriate fixture. Since the workbench is flat and the device is for non-contact measurement, the keyboard can be placed directly on it, and only a suitable limit device needs to be selected to determine the position of the keyboard on the horizontal plane.

2. Adjust the height of the workbench. Start the hydraulic device, the workbench rises slowly, and observe the computer image at the same time, and stop rising when clear stripes appear on the screen.

3. Image acquisition. At the beginning of the detection, the computer first collects an image, and then gives a certain number of pulses to the stepping motor of the stage, the grating moves up a certain distance, and collects the second image. Repeat the above steps until 4 images are collected and the grating returns to the initial position.

4. Flatness calculation. At this time, the computer will display the first image collected. Drag the mouse to select the area to be detected. After the selection is completed, the computer can directly output the three-dimensional shape of the surface of the object. If the flatness calculation formula is predetermined, the flatness can be directly calculated.

In large-scale production, the batch of the same workpiece is large, and there is no need to repeatedly adjust the workbench and select the area. After each workpiece is installed, the test starts. Through the corresponding program, the measurement area can be automatically selected after the image acquisition is completed. Direct calculation Out of flatness, and then judge whether the workpiece is qualified.

To sum up, the utility model has the advantage that it can quickly and accurately reflect the flatness of objects in the flatness detection of large-area objects. At the same time, the device adopts non-contact measurement, which will not cause any damage to the surface of the workpiece, and has a simple structure, low cost, simple operation, easy automation, and can adapt to online detection in assembly line production. It has a very wide application prospect.

Claims (6)

1. A large-area object flatness detection device, comprising The base (1) acts as a stable support, and its upper and lower surfaces are horizontally parallel to each other; a hydraulic device (2), which is stably supported on the base (1), and whose upper and lower surfaces are horizontally parallel to each other; The workbench (4), which is located on the hydraulic device (2), moves up and down under the control of the hydraulic device (2), and its upper and lower surfaces are parallel to each other horizontally; Dustproof cover (5), it is box body, and the bottom is open, and the place that the back contacts with rod-shaped supporting frame has breach; The vertical support plate (6) is located on the base (1), the rear side of the hydraulic device (2), the workbench (4) and the dust cover (5), and is connected with the base (1), the hydraulic device ( 2) It is fixedly connected with the dust cover (5); It is characterized in that it also includes a measuring mechanism integrally located in the dust cover (5), the measuring mechanism includes a rod-shaped support frame (9), which is vertically fixed on the front side of the vertical support plate (6); The rest of the components from bottom to top are grating support (16), which is installed horizontally; grating (7), which is installed horizontally on the grating support (16); The displacement stage (8), which is fixedly connected with the rod-shaped support frame (9), is fixedly connected with the grating support (16), and is used to control the grating (7) to move up and down; A slide block (12), which can slide up and down along the rod-shaped support frame (9); The load bracket (15), which is fixedly connected with the slide block (12), is loaded with a horizontally movable CCD camera (14) and a light source (10), wherein the CCD camera (14) faces the grating (7) to take pictures, and the light source ( 10) emit light towards the grating (7), and the optical center (14) of the CCD camera and the light source (10) are located in the same horizontal plane; The control device is connected with the displacement platform (8) and controls its movement up and down. 2. large-area object flatness detection device as claimed in claim 1, wherein load support (15) is a T-shaped bar placed horizontally, slide block (12) is fixedly connected with the rear end of T-shaped bar, and T-shaped bar The front end is a section of guide rail, and the left and right ends of the front end of the T-shaped bar (15) are respectively equipped with a first slide block (11) and a second slide block (13), and the first slide block (11) and the second slide block (13) all can slide left and right in horizontal plane along the guide rail of T bar front end, fixedly install CCD camera (14) and light source (10) respectively on the first slide block (11) and the second slide block (13). 3. The large-area object flatness detection device as claimed in claim 1 or 2, wherein the displacement table (8) adopts a stepping motor that can move up and down. 4. The large-area object flatness detection device according to claim 1 or 2, further comprising several support columns (3) for supporting the workbench (4). 5. The large-area object flatness detection device according to claim 4, wherein the number of support columns (3) is four. 6. The large-area object flatness detection device according to claim 1 or 2, wherein a fixture is installed on the workbench (4) for fixing the object under test.