CN209764029U - Detection device for detecting three-dimensional shape of object - Google Patents

Abstract

The utility model discloses a detection apparatus for be used for detecting three-dimensional shape of object belongs to optical imaging technical field. The detection device comprises a projection unit and an imaging acquisition unit, wherein the imaging acquisition unit comprises a camera and a telecentric lens arranged on the camera, and the telecentric lens is arranged right above an object; the projection unit comprises at least three projection light machines; the at least three projection light machines are circumferentially and uniformly distributed on the periphery of the telecentric lens by taking the optical axis of the telecentric lens as a central axis; the reflector assembly is arranged below the light-emitting surface of each projection light machine; and the grating stripes generated by the projection light machine are reflected by the reflecting mirror assembly to reach an object. The utility model discloses a to the multidirectional projection of object to get rid of because the shadow region that the object shape is complicated to cause, improve the integrality of object three-dimensional formation of image.

Description

A detection device for detecting the three-dimensional shape of an object

technical field

The utility model relates to the technical field of optical imaging, in particular to a detection device for detecting the three-dimensional shape of an object.

Background technique

In the electronics manufacturing industry, it is often necessary to detect the three-dimensional shape of the circuit board, components and solder paste that fixes the components, check whether the dimensions meet the standards, and improve the yield. The commonly used three-dimensional shape detection method is the phase measurement method, that is, projecting a sinusoidal grating on the object to be detected through the projection light machine, and using the lens to collect the image, and then moving the phase of the grating by 1/4 cycle, and then collecting the image; and so on , a total of four image acquisitions under different phases are carried out, and the acquired image data is transferred to relevant software for processing to complete the complete imaging of the three-dimensional shape of the object.

Using the projection light machine of the existing detection device to project the object, for the three-dimensional object with complex shape and structure, it is easy to produce a shadow area on the object, which will affect the object to present a complete three-dimensional image.

Therefore, it is urgent to provide a detection device for detecting the three-dimensional shape of an object to solve the above problems.

Utility model content

The purpose of the utility model is to provide a detection device for detecting the three-dimensional shape of an object, which can project the object from multiple directions and effectively remove the shadow area caused by the complex shape of the object.

In order to achieve the above purpose, the following technical solutions are provided:

A detection device for detecting the three-dimensional shape of an object, comprising a projection unit and an imaging acquisition unit, the imaging acquisition unit includes a camera and a telecentric lens arranged on the camera, the telecentric lens is arranged on the front of the object above;

The projection unit includes at least three projection light machines; at least three projection light machines are uniformly distributed in the circumferential direction around the telecentric lens with the optical axis of the telecentric lens as the central axis.

Further, the projection unit also includes an optical path conversion mechanism; the optical path conversion mechanism includes at least three reflector assemblies, and one reflector assembly is arranged under the light-emitting surface of each projector; The grating fringes generated by the projection light machine are reflected on the optical path through the reflector assembly until reaching the object.

Further, the reflector assembly includes a first reflector and a second reflector, the first reflector is arranged close to the optical axis of the telecentric lens, and the second reflector is far away from the optical axis of the telecentric lens optical axis setting;

The reflective surface of the first reflector is set away from the optical axis of the telecentric lens, the reflective surface of the second reflector is set towards the optical axis of the telecentric lens, and the grating stripes of the projection light engine The object is projected onto the object through the reflection of the reflection surface of the first reflection mirror and the reflection surface of the second reflection mirror in sequence.

Further, the angle range between the reflective surface of the first reflector and the optical axis of the telecentric lens is [68°, 72°]; the reflective surface of the second reflector and the telecentric lens The angle range between the optical axes of the lenses is [43°, 47°].

Further, the projection unit also includes an adjustment frame, each of the projection optical machines is arranged on the upper part of the adjustment frame through an optical machine bracket, and each of the mirror assemblies is installed on the said adjustment frame through a mirror bracket. Adjust the lower part of the stand.

Further, the position of the optomechanical support relative to the adjustment frame is adjustable.

Further, the mirror support includes a first sub-support and a second sub-support, the first reflector is arranged on the first sub-support, and the second reflector is arranged on the second sub-support; The first sub-bracket is fixed on the lower part of the adjustment frame;

The position of the second sub-bracket relative to the adjustment frame is adjustable.

Further, the reflector bracket also includes a connecting rod, which is fixedly connected to the first sub-bracket and the second sub-bracket; there are two connecting rods, and the two connecting rods are arranged symmetrically. It is arranged on both sides of the first sub-support and the second sub-support.

Further, the position of the connecting rod relative to the second sub-bracket is adjustable, so as to adapt to the change of the position of the second sub-bracket on the adjustment frame.

Further, a two-dimensional light source is also provided between the telecentric lens and the object; the two-dimensional light source includes an upper overhead light source and a lower ring light source, and the ring light source cooperates with the overhead light source Used to acquire a color two-dimensional image of the object.

Compared with the prior art, the utility model has the beneficial effects:

1) The utility model realizes the multi-directional projection of the object by setting at least three projection light machines, so as to remove the shadow area caused by the complex shape of the object and improve the integrity of the three-dimensional imaging of the object;

2) The camera of the present utility model is equipped with a telecentric lens, and the image magnification ratio obtained by the telecentric lens within a certain object distance range will not change with the change of the object distance, and there is no strabismus and Occlusion improves the accuracy of the 3D data of the object.

Description of drawings

Fig. 1 is the perspective view of detection device in the utility model embodiment;

Fig. 2 is the front view of detection device in the utility model embodiment;

Fig. 3 is a schematic structural view of the projection unit in the embodiment of the present invention;

Fig. 4 is a schematic diagram of the structure of the projection light machine installed on the adjustment frame in the embodiment of the present invention;

Fig. 5 is a schematic structural view of the reflector assembly arranged on the adjustment frame in the embodiment of the present invention.

Reference signs:

1-imaging acquisition unit; 11-camera; 12-telecentric lens;

2-projection unit; 21-projection optical engine; 22-reflector assembly; 221-first reflector; 222-second reflector; 23-optical engine support; 231-first strip hole; 24-reflector Bracket; 241-the first sub-support; 242-the second sub-support; 243-connecting rod; 2431-the third strip hole; 25-adjusting frame; 251-the first threaded hole; 252-the second strip hole;

3-two-dimensional light source; 31-overhead light source; 32-ring light source;

4- Object.

Detailed ways

In order to make the technical problems solved by the utility model, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the utility model will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only Some embodiments of the utility model, but not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present utility model.

As shown in Figures 1-2, this embodiment discloses a detection device for detecting the three-dimensional shape of an object, which includes a projection unit 2 and an imaging acquisition unit 1, and the imaging acquisition unit 1 includes a camera 11 and a remote sensor configured on the camera 11 The telecentric lens 12 and the telecentric lens 12 are arranged directly above the object 4 to collect images of the object 4 . The telecentric lens 12 is based on its unique optical characteristics: high resolution, ultra-wide depth of field, ultra-low distortion and unique parallel light design, etc., so that the image magnification obtained by the telecentric lens 12 within a certain range of object distance will not It changes with the change of the object distance, and there is no squint and occlusion when shooting the object 4 with a height, which improves the accuracy of the three-dimensional data of the object 4 .

The projection unit 2 is arranged on the periphery of the telecentric lens 12 to provide a light source for the object 4; specifically, the projection unit 2 includes a projection light machine 21 and an optical path conversion mechanism. The reflection of the light path reaches the object 4, forming a light spot on the object 4, and the telecentric lens 12 receives the light reflected by the object 4 to realize image collection. If the three-dimensional shape of the object 4 is more complicated, the projection light machine 21 will only form one light spot on the object 4, which will obviously cause more shadows on the object, so that the imaging acquisition unit 1 cannot accurately collect the three-dimensional shape of the object, affecting Accurate imaging of object 4. Therefore as shown in Figure 1-2, in the present embodiment, projection unit 2 is provided with at least three projection light machines 21; The optical axis of 12 is the central axis, and it is evenly distributed in the circumferential direction around the periphery of the telecentric lens 12, thereby ensuring that grating stripes in multiple directions can be projected onto the object 4 and reducing shadows on the object 4.

Specifically, the projection optical machine 21 includes an optical-mechanical light source, a lens, a prism, and a digital micromirror chip. The lens is located between the optical-mechanical light source and the prism, and the prism is located between the lens and the digital micromirror chip. Lenses, prisms, and digital micromirror chips generate grating stripes. Using digital micromirror chips can directly phase-shift the grating stripes, which is easier to control than traditional physical gratings, and the grating stripes generated are also clearer. visible.

In order to realize that the grating stripes of each projection light machine 21 can accurately reach the object 4, the optical path conversion mechanism includes at least three reflector assemblies 22, and the number of reflector assemblies 22 is the same as the number of projection light machines 21 In a corresponding relationship, a reflector assembly 22 is provided directly below the light emitting surface of each projection light engine 21 , and the reflector assembly 22 is evenly distributed around the periphery of the telecentric lens 12 in the circumferential direction. Specifically, the reflector assembly 22 includes a first reflector 221 and a second reflector 222, the first reflector 221 is arranged close to the optical axis of the telecentric lens 12, and the second reflector 222 is arranged away from the optical axis of the telecentric lens 12 The reflective surface of the first reflector 221 is set away from the optical axis of the telecentric lens 12, and the reflective surface of the second reflector 222 is set towards the optical axis of the telecentric lens 12, and the grating stripes of the projection light machine 21 pass through the first reflector successively 221 and the reflection of the reflection surface of the second mirror 222 are finally projected onto the object 4 (as shown by the dotted line in FIG. 2 ). In this embodiment, each projection light engine 21 and corresponding two reflectors are all positioned at the same orientation on the periphery of the telecentric lens 12. Since the precision of the telecentric lens 12 is high and the required spot size is small, the above-mentioned setting at the same orientation can The optical path is shortened, and the size of the light spot projected on the object 4 is reduced, so the requirements for the use of the telecentric lens 12 can be met.

As shown in Figure 2, in the present embodiment, the included angle between the reflective surface of the first reflector 221 and the optical axis of the telecentric lens 12 is set to be α ₁ , the reflective surface of the second reflector 222 and the telecentric lens 12 The included angle between the optical axes is β ₁ , the angle range of α ₁ is [68°, 72°], and the angle range of β ₁ is [43°, 47°].

During specific implementation, the detection device can optionally be provided with four, five, six or more projection light machines 21, projecting light spots from more directions, and avoiding the shadow caused by the complex three-dimensional shape of the object 4 as much as possible; at the same time , it is necessary to maintain a plurality of projection light machines 21 evenly distributed on the outer periphery of the telecentric lens 12, and each projection light machine 21 can be equipped with a reflector assembly 22 located in the same orientation to complete the conversion of the optical path.

The grating fringes projected by each light projector 21 are projected by the reflector assembly 22 disposed below it to form a light spot on the object 4 . In the case of setting a plurality of projection light machines 21, only when the light spots formed by the multiple projection light machines 21 on the object 4 are overlapped, can it be ensured that the telecentric lens 12 can accurately obtain the image information of the object 4; Due to the problem that the light spots of the projection light machine 21 cannot be completely overlapped due to errors, the position of the projection light machine 21 and the second reflector 222 of the reflector assembly 22 under the projection light machine 21 can be fine-tuned during the installation process. Then the propagation path of the light is changed to realize the adjustment of the position of the light spot. In order to achieve the above purpose, as shown in Figure 3-5, the projection unit 2 also includes an adjustment frame 25, each projection light engine 21 is set on the upper part of the adjustment frame 25 through the light engine bracket 23, and each reflector assembly 22 The reflector bracket 24 is arranged on the lower part of the adjusting frame 25 . Integrating the projection light engine 21 and the reflector assembly 22 through the bracket structure can improve the compactness of the entire detection device and reduce the manufacturing cost of the device.

For the projection light machine 21, in order to realize the position adjustment of the projection light machine 21 relative to the adjustment frame 25, optionally, the adjustment frame 25 is provided with a first threaded hole 251, and the bottom of the light machine support 23 is provided with a first threaded hole 251. The strip hole 231, the bolt passes through the first strip hole 231 and the first threaded hole 251 in turn, and the projection light machine 21 is fixed on the adjustment frame 25, and the different positions of the first strip hole 231 can be adjusted by adjusting the bolt. The position of the projector light machine 21 is adjusted relative to the frame 25 . Optionally, in this embodiment, the first strip-shaped hole can be set on the adjustment frame 25 , and the first threaded hole can be set on the optical-mechanical support 23 , so that the position of the optical-mechanical support 23 can also be adjusted. The optomechanical support 23 can also adopt other structures to realize position adjustment relative to the adjustment frame 25 , which will not be repeated here.

For the reflector assembly 22, the reflector bracket 24 includes a first sub-support 241 and a second sub-support 242, the first reflector 221 is located on the first sub-support 241, and the second reflector 222 is located on the second sub-support. On the bracket 242; the first sub-bracket 241 is optionally fixed on the lower part of the adjustment frame 25 through a bolt structure. The top of the second sub-bracket 242 is provided with a second threaded hole, and the adjusting frame 25 is provided with a second bar-shaped hole 252, and the bolt passes through the second bar-shaped hole 252 and the second threaded hole successively, and the second sub-support 242 is fixed. On the adjustment frame 25; by adjusting the different positions of the bolts in the second strip hole 252, the position of the second sub-support 242 relative to the adjustment frame 25 and the first sub-support 241 can be adjusted, that is, the position of the second reflector 222 relative to the first sub-support 241 can be adjusted. The position of the first mirror 221. Optionally, in this embodiment, the second bar-shaped hole can be set on the second sub-bracket 242, while the second threaded hole is set on the adjustment frame 25, and the position of the second sub-bracket 242 can also be adjusted. . The second sub-bracket 242 can also adopt other structures to achieve position adjustment relative to the adjustment frame 25, which will not be repeated here.

Furthermore, after the adjustment of the positions of the projection light engine 21 and the reflector assembly 22 is completed, the detection device will inevitably move, or be subjected to external impact, etc., which will cause vibration of the internal structure. The relative positions of the two reflectors change during this process, causing the projection of the light spot to be misplaced. The reflector bracket 24 is set to also include a connecting rod 243, and the connecting rod 243 is fixedly connected to the first sub-support 241 and the second sub-support 242, so that in the detection device When the vibration occurs, the relative position of the first reflector 221 and the second reflector 222 does not change, and the light can be projected according to the original emission angle. Specifically, there are two connecting rods 243 , and the two connecting rods 243 are symmetrically arranged on both sides of the first sub-frame 241 and the second sub-frame 242 . For each connecting rod 243 , one end of the connecting rod 243 is fixedly connected to the first sub-bracket 241 , and the other end is fixedly connected to the second sub-bracket 242 optionally through a bolt structure. One end that the connecting rod 243 is connected with the second branch bracket 242 is provided with a third strip hole 2431, and the side wall of the second branch bracket 242 is provided with a third threaded hole, and the bolt passes through the third strip hole and the third thread successively. The holes fix the connecting rod 243 to the second branch bracket 242 . When the position of the second sub-bracket 242 on the adjustment frame 25 changes, the position of the bolt in the third bar-shaped hole 2431 can be correspondingly changed to adapt to the change of the relative position of the second sub-bracket 242 and the first sub-bracket 241 .

It can be seen from the above that the detection device can adjust the position of the light spot by adjusting the projection light engine 21 , and can also adjust the position of the light spot by adjusting the second reflector 222 . In order to improve the adjustment efficiency, simplify the adjustment steps, and make the light spot adjustment have a certain benchmark, the projection light machines 21 are grouped, and the projection light machines 21 of a certain group are fixed, but the corresponding second reflector 222 is adjustable. A group of projection light engines 21 can be adjusted, but the corresponding second reflector 222 is fixed, so that the rapid adjustment of spot overlap can be realized with as few operations as possible. Taking a detection device with four projection light machines 21 as an example, the four projection light machines 21 include a first projection light machine, a second projection light machine, a third projection light machine, and a fourth projection light machine arranged clockwise. Correspondingly, the quantity of reflector assembly 22 is also four, which are respectively the first reflector assembly, the second reflector assembly, the third reflector assembly and the first reflector assembly which are sequentially arranged in the clockwise direction Four reflecting mirror assemblies, the first reflecting mirror assembly is arranged directly below the first projection light engine. When adjusting the coincidence of the light spots, the positions of the first projection light machine and the third projection light machine relative to the adjustment frame 25 are adjustable, the positions of the second projection light machine and the fourth projection light machine are fixed relative to the adjustment frame 25, and the first reflector The second reflector 222 of the mirror assembly and the second reflector 222 of the third reflector assembly are fixed relative to the position of the adjustment frame 25, and the second reflector 222 of the second reflector assembly and the fourth reflector assembly The position of the second reflector 222 relative to the adjustment frame 25 is adjustable. In this way, first by adjusting the positions of the first projection light machine and the third projection light machine, the light spots of the two can overlap, and then use the light spot as a reference to adjust the second reflector 222 and the fourth reflector assembly of the second reflector assembly. The second reflector 222 of the reflector assembly realizes the coincidence of the light spots of the second projection light machine and the fourth projection light machine.

For the projection optical engine 21 whose position is not adjustable relative to the adjustment frame 25, the first strip hole 231 is optionally not provided on the optical engine bracket 23, but a threaded hole is directly opened to complete the installation of the optical engine bracket 23 and the adjustment frame 25. connection, or use other fixed structures to connect; similarly, with respect to the second reflector 222 whose position is not adjustable with respect to the adjustment frame 25, the second strip-shaped hole 252 is optionally no longer provided on the adjustment frame 25, and also directly The connection between the adjustment frame 25 and the second sub-support 242 is completed by opening threaded holes, or other fastening structures are used for connection.

The detection device in this embodiment can also realize the collection of two-dimensional images of the object 4 . In order to realize this function, a two-dimensional light source 3 is provided between the telecentric lens 12 and the object 4 . When shooting a two-dimensional image, the projection light engine 21 is turned off, and the two-dimensional light source 3 provides a light source for the telecentric lens 12 to acquire the two-dimensional image of the object 4 . Specifically, the two-dimensional light source 3 includes an upper overhead light source 31 and a lower ring light source 32 . The overhead light source 31 is arranged with three-color lamps, with three channels of red (R), green (G), and blue (B). By selecting different channel combinations, different colors of light can be irradiated. When it irradiates the copper foil And low-angle objects, it can make the image color uniform without distortion. The inner surface of the ring light source 32 is arranged with four layers of lights, which are respectively the first layer of lights, the second layer of lights, the third layer of lights and the fourth layer of lights arranged from bottom to top, the first layer of lights, the second layer of lights and the third layer lights are all monochromatic lights, and the first layer lights, the second layer lights and the third layer lights include three colors of red, green and blue. Optionally, in this embodiment, the color of the first layer of lights can be set to be red, the color of the second layer of lights to be green, and the color of the third layer of lights to be blue; or optionally, the color of the first layer of lights can be set Green, the color of the lights on the second layer is red, and the color of the lights on the third layer is blue, and the distribution of other types of colors will not be repeated here. The fourth layer of light is a three-color light with three channels of R, G, and B. By choosing different channel combinations, different colors of light can be irradiated. The ring light source 32 is used in conjunction with the overhead light source 31 to obtain a color two-dimensional image of the object 4 . Further, a light-transmitting hole (not shown in the figure) is opened in the middle of the overhead light source 31. After the light from the two-dimensional light source 3 hits the object 4, it is reflected by the surface of the object 4 and passes through the light-transmitting hole. After reaching the telecentric lens 12, the object imaging is realized. For the telecentric lens 12, it requires that the light incident into the telecentric lens 12 is parallel to the optical axis of the telecentric lens 12, so the diameter of the light transmission hole of the overhead light source 31 will ensure that it is at least larger than the telecentric lens 12. Only when the outer diameter of the lens is large can it be ensured that the light rays reflected by the object 4 reach the telecentric lens 12 in parallel. Optionally, the overhead light source 31 may be a flat light source, and the flat light source illuminates downward. When a flat light source is used, since it is necessary to open a larger-sized light-transmitting hole on the flat light source, this will undoubtedly reduce the number of lamps on the flat light source, thereby reducing the brightness of the flat light source, making the light irradiated on the object 4 smaller. Less, resulting in darker images. Therefore, preferably, the overhead light source 31 in this embodiment adopts a cone-shaped light source, and the cone-shaped light source is a trumpet-shaped structure with a narrow top and a wide bottom. Compared with the flat light source, more lamps can be arranged on the inner surface of the conical light source, and the horn-shaped structure can play the role of gathering light, and more light can be irradiated on the object 4, so that the image is no longer dark.

Note that the above are only preferred embodiments of the present invention and the applied technical principles. Those skilled in the art will understand that the utility model is not limited to the specific embodiments described here, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the utility model. Therefore, although the utility model has been described in detail through the above embodiments, the utility model is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the utility model. The scope of the present invention is determined by the appended claims.

Claims (10)

1. A detection apparatus for detecting a three-dimensional shape of an object, comprising a projection unit (2) and an imaging acquisition unit (1), wherein the imaging acquisition unit (1) comprises a camera (11) and a telecentric lens (12) configured on the camera (11), and the telecentric lens (12) is arranged right above an object (4);

The projection unit (2) comprises at least three projection light machines (21); the at least three projection optical machines (21) are circumferentially and uniformly distributed on the periphery of the telecentric lens (12) by taking the optical axis of the telecentric lens (12) as a central axis.

2. The detection device according to claim 1, wherein the projection unit (2) further comprises an optical path switching mechanism; the light path conversion mechanism comprises at least three reflector assemblies (22), and one reflector assembly (22) is arranged below the light emergent surface of each projection optical machine (21); the grating stripes generated by the projection optical machine (21) are reflected by the reflecting mirror assembly (22) through an optical path and then reach the object (4).

3. the inspection device of claim 2, wherein the mirror assembly (22) includes a first mirror (221) and a second mirror (222), the first mirror (221) being disposed proximate to an optical axis of the telecentric lens (12) and the second mirror (222) being disposed distal from the optical axis of the telecentric lens (12);

The reflecting surface of the first reflecting mirror (221) deviates from the optical axis setting of the telecentric lens (12), the reflecting surface of the second reflecting mirror (222) faces the optical axis setting of the telecentric lens (12), and the grating stripes generated by the projection light machine (21) are sequentially projected onto the object (4) through the reflecting surface of the first reflecting mirror (221) and the reflection of the reflecting surface of the second reflecting mirror (222).

4. the inspection device of claim 3, wherein the reflecting surface of the first mirror (221) is at an angle to the optical axis of the telecentric lens (12) in the range of [68 °, 72 ° ]; the included angle range between the reflecting surface of the second reflecting mirror (222) and the optical axis of the telecentric lens (12) is [43 degrees ] and 47 degrees ].

5. The detection device according to claim 3, wherein the projection unit (2) further comprises an adjusting frame (25), each projection light machine (21) is disposed on an upper portion of the adjusting frame (25) through a light machine support (23), and each mirror assembly (22) is disposed on a lower portion of the adjusting frame (25) through a mirror support (24).

6. The detection device according to claim 5, wherein the position of the opto-mechanical support (23) relative to the adjustment frame (25) is adjustable.

7. The detection device according to claim 5, wherein the mirror support (24) comprises a first sub support (241) and a second sub support (242), the first mirror (221) being provided on the first sub support (241) and the second mirror (222) being provided on the second sub support (242); the first sub-bracket (241) is fixedly arranged at the lower part of the adjusting bracket (25);

the position of the second sub-bracket (242) relative to the adjusting bracket (25) is adjustable.

8. The detection apparatus according to claim 7, wherein the mirror support (24) further comprises a connection rod (243), the connection rod (243) fixedly connecting the first sub support (241) and the second sub support (242); the number of the connecting rods (243) is two, and the two connecting rods (243) are symmetrically arranged on two sides of the first sub-bracket (241) and the second sub-bracket (242).

9. The detection apparatus according to claim 8, characterized in that the position of the connecting rod (243) relative to the second sub bracket (242) is adjustable to accommodate a change in the position of the second sub bracket (242) at the adjustment bracket (25).

10. the detection apparatus according to claim 1, wherein a two-dimensional light source (3) is further arranged between the telecentric lens (12) and the object (4); the two-dimensional light source (3) comprises an upper overhead light source (31) and a lower ring light source (32), the ring light source (32) being used in cooperation with the overhead light source (31) for acquiring a color two-dimensional image of the object (4).