Light source device, lighting device and detection system

Abstract

The utility model discloses a light source device, a lighting device and a detection system, and belongs to the technical field of machine vision detection. The light source device comprises a light-emitting element used for emitting a first light beam, and the first light beam has a preset divergence angle; the convergence element is used for converging the first light beam and converging the first light beam into a second light beam, and the second light beam has a preset convergence angle; the light uniformizing element comprises a light uniformizing part, the light uniformizing part is provided with a light inlet surface and a light outlet surface, the light inlet surface is used for receiving the second light beam, the light uniformizing part is used for uniformizing the second light beam into a third light beam, the light outlet surface is used for emitting the third light beam, and the third light beam is provided with a preset light spot on the light outlet surface; and the imaging element is used for guiding the third light beam and imaging the preset light spot to a measured object. The light source device provided by the utility model enables the brightness of light spots irradiated on a measured object to be more uniform.

Description

[Technical field]

[0001] The utility model relates to the field of machine vision detection, in particular to a light source device, a lighting device and a detection system for machine vision detection. [Background technology]

[0002] Machine vision inspection is widely used in the inspection of industrial products. It displays the inspected objects in an image and has the advantage of quickly and accurately inspecting the inspected objects compared to previous visual inspection methods.

[0003] The machine vision inspection system includes an illumination device and an image detection device. The illumination device is used to project illumination light onto the object to be inspected. The illumination light is captured by the image detection device after being reflected or scattered by the object to be inspected, and an image of the surface of the object to be inspected is displayed, and then the object to be inspected is inspected based on the obtained image.

[0004] For tiny products such as semiconductor chips, the appearance, defects, and logos of the objects to be inspected are even smaller in size, so the light beam irradiating the object to be inspected is required to have a stronger light intensity and more uniform brightness. [Contents of the utility model]

[0005] The utility model aims to provide a light source device, an illumination device and a detection system, so as to project a uniform light spot.

[0006] In a first aspect, the utility model provides a light source device, comprising:

[0007] A light emitting element, configured to emit a first light beam, wherein the first light beam has a preset divergence angle;

[0008] A converging element, used for converging the first light beam into a second light beam, wherein the second light beam has a preset converging angle;

[0009] A light homogenizing element, comprising a light homogenizing portion, the light homogenizing portion having a light incident surface and a light exiting surface, the light incident surface is used to receive the second light beam, the light homogenizing portion is used to homogenize the second light beam into a third light beam, the light exiting surface is used to emit the third light beam, wherein the third light beam has a preset light spot on the light exiting surface; and

[0010] An imaging element is used to guide the third light beam and image the preset light spot onto the object to be measured.

[0011] In some possible implementations, the light-emitting element includes at least two LED light-emitting chips, and the at least two LED light-emitting chips are used to emit light beams of at least two different wavelengths.

[0012] In some possible implementations, the light emitting element includes:

[0013] an excitation light source, configured to emit excitation light; and

[0014] The wavelength conversion element receives the excitation light and converts at least a portion of the excitation light into a converted light having a wavelength different from that of the excitation light.

[0015] In some possible implementations, the first light beam has a divergence angle of not less than 120 degrees.

[0016] In some possible implementations, a convergence angle of the second light beam is no greater than 50 degrees.

[0017] In some possible implementations, the converging element includes:

[0018] A collecting lens, used for collecting the first light beam and reducing the divergence angle of the first light beam;

[0019] The converging lens receives the first light beam from the collecting lens and converges the first light beam into a converging light beam.

[0020] In some possible implementations, the light homogenizing element includes:

[0021] The light guide rod has a preset length, the light guide rod has a light incident surface for receiving the first light beam and a light exit surface for emitting the second light beam, the light guide portion includes the light guide rod, the light guide rod is used to propagate the second light beam and internally reflect the second light beam multiple times in the direction of travel of the second light beam.

[0022] In some possible implementations, the length of the light guide rod is not less than 10 mm.

[0023] In a second aspect, the utility model provides a lighting device, comprising the light source device as described above.

[0024] In a third aspect, the utility model provides a detection system, comprising:

[0025] An illumination device, used for projecting illumination light onto the object to be measured, wherein the illumination device comprises the light source device as described above; and

[0026] The detection device receives the illumination light from the object to be detected and obtains the image information of the object to be detected according to the illumination light.

[0027] Beneficial effects of the utility model:

[0028] The light source device of the utility model forms a preset light spot with uniform brightness on the light emitting surface of the light homogenizing element, and the imaging element images the preset light spot onto the measured object, so that the light spot irradiated onto the measured object has the characteristic of uniform brightness.

Brief Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0030] Figure 1 A schematic diagram of a detection system according to an embodiment of the present application.

[0031] Description of reference numerals:

[0032] 2. Object to be measured;

[0033] 10. Light source device; 30. Image acquisition device; 31. Field of view;

[0034] 100, light emitting element; 101, converging element; 102, light homogenizing element; 103, imaging element; 104, first light beam; 105, second light beam; 106, third light beam;

[0035] 1010, collecting lens; 1011, converging lens;

[0036] 1020, light guiding portion; 1021, light incident surface; 1022, light emitting surface. [Specific implementation method]

[0037] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0038] Figure 1 An exemplary illustration of a detection system of an embodiment of the present application is shown. The detection system of the embodiment of the present application includes an illumination device and a detection device, wherein the illumination device is used to project illumination light to the object 2 to be detected, and at least part of the illumination light is reflected or scattered after being incident on the surface of the object 2 to be detected, and the detection device is used to obtain the illumination light reflected or scattered by the object 2 to be detected, and then obtain image information of the object 2 to be detected.

[0039] The lighting device at least includes a light source device 10 and a carrier (not shown in the figure), the light source device 10 is used to generate illumination light for detecting the object 2, and the carrier is used to support the light source device 10, including but not limited to fixing, positioning, and adjusting the light source device 10. Figure 1 The light source device 10 according to the embodiment of the present application is described.

[0040] like Figure 1 The light source device 1 of the embodiment of the present application includes a light emitting element 100 , a converging element 101 , a light homogenizing element 102 and an imaging element 103 . The light-emitting element 100 is used to emit a first light beam 104, wherein the first light beam 104 has a preset divergence angle; the converging element 101 is used to converge the first light beam 104 and converge the first light beam 104 into a second light beam 105, wherein the second light beam 105 has a preset convergence angle; the light homogenizing element 102 includes a light homogenizing portion 1020, the light homogenizing portion 1020 has an incident surface 1021 and a light emitting surface 1022, the light incident surface 1021 is used to receive the second light beam 105, the light homogenizing portion 1020 is used to homogenize the second light beam 105 into a third light beam 106, the light emitting surface 1022 is used to emit the third light beam 106, wherein the third light beam 106 has a preset light spot on the light emitting surface 1022; the imaging element 103 is used to guide the third light beam 106 and image the preset light spot onto the object 2 to be measured.

[0041] The light emitting element 100 is, for example, selected as a point light source, that is, the light emitted by the light emitting element 100 can be equivalent to being emitted from a light point and gradually expands as the light beam propagates. In one example, the first light beam 104 emitted by the light emitting element 100 has a divergence angle of not less than 120 degrees. The divergence angle of the first light beam 104 emitted by the light emitting element 100 is, for example, less than 180 degrees. In some examples, the divergence angle of the first light beam 104 emitted by the light emitting element is, for example, less than 150 degrees.

[0042] In some embodiments of the present application, the light-emitting element 100 includes an LED light-emitting chip. The light emitted by the LED light-emitting chip has the characteristics of Lambertian distribution, so the first light beam 104 emitted by the LED light-emitting chip has a preset divergence angle. The light-emitting element 100 may also include at least two LED light-emitting chips, and the light beams emitted by the at least two LED light-emitting chips are mixed to obtain the first light beam 104. The at least two LED light-emitting chips can be arranged in an array, or they can be combined in other preset ways. Among them, at least two LED light-emitting chips can be set so that the light beams they emit have the same wavelength, so the light amount of the first light beam 104 can be increased by the combination of at least two LED light-emitting chips, and then after passing through the converging element 101, the uniform light element 102 and the imaging element 103 in the subsequent light path, the illumination light projected onto the object 2 to be measured has a higher brightness. At least two LED light-emitting chips can also be configured to emit at least two different wavelengths of light beams. When detecting the object 2 to be detected, based on the different material properties of the object 2 to be detected, different wavelengths of illumination light can show different effects. For example, blue light has a short wavelength and weak penetration, so it is more effective when detecting defects such as scratches. Infrared light has a long wavelength and strong penetration, and can be used to detect substances below the surface through the surface of the object. Therefore, when at least two LED light-emitting chips emit at least two different wavelengths of light beams, the ability to detect different material properties of the object 2 to be detected can be improved. In addition, in some examples, a drive control device can be set to drive at least two LED light-emitting chips to drive at least two LED light-emitting chips to partially or fully turn on or off.

[0043] In some embodiments of the present application, the light-emitting element 100 includes an excitation light source and a wavelength conversion element (not shown). The excitation light source is used to emit excitation light. The emitted excitation light is incident on the wavelength conversion element. The wavelength conversion element has a wavelength conversion material. The wavelength conversion material converts at least part of the incident excitation light into a converted light with a different wavelength range. Exemplarily, the excitation light source emits blue excitation light, the wavelength conversion element has a yellow fluorescent material, the blue excitation light is incident on the yellow fluorescent material, and the yellow fluorescent material converts at least part of the blue excitation light into a yellow converted light. Exemplarily, the excitation light source can be selected as a laser diode. The laser diode is used to emit laser light. The laser has the characteristics of high energy density and high collimation. The wavelength conversion element converts at least part of the laser light into a converted light. The emitted converted light not only has a high brightness, but also has a Lambertian distribution of the converted light emitted through the wavelength conversion element.

[0044] The converging element 101 is used to change the diverging first light beam 104 into a converging second light beam 105, so as to couple the second light beam 105 into the light homogenizing element 102. The converging element 101 is, for example, one or more optical elements with refractive power, such as lenses.

[0045] In some embodiments of the present application, the converging element 101 can be configured as a focusing lens, which is used to receive the first light beam 104 emitted by the light-emitting element 100, and converge the divergent first light beam 104 into a converging second light beam 105. The focusing lens has a focus facing in front of one side of the light-guiding element 102. The light-guiding element 102 can be arranged near the focal position of the focusing lens to couple the second light beam 105 into the light-guiding element 102. The focusing lens can be configured with fewer optical elements to achieve the collection of the first light beam 104 and the coupling of the second light beam 105.

[0046] In some embodiments of the present application, the converging element 101 may be configured to include at least two optical elements. For example, the converging element 101 includes a collecting lens 1011 and a converging lens 1012. The collecting lens 1011 is used to receive the first light beam 104 emitted from the light emitting element 100 and reduce the divergence angle of the first light beam 104. In some examples, the collecting lens 1011 is configured to be a collimating lens element, for example, for converging the first light beam 104 into a parallel light beam having approximately 90 degrees. In some examples, the collecting lens 1011 is used to converge the first light beam 104 into a divergent light beam having a certain divergence angle, for example, the divergence angle after convergence is greater than 90 degrees. The converging lens 1012 is used to receive the first light beam 104 after convergence from the collecting lens 1011, and further converge the first light beam 104, so that the first light beam 104 converges from a divergent or collimated light beam to a converging second light beam 105. The converging lens 1012 has a focus in front of the light guide element 102. The light guide element 102 can be arranged near the focal position of the converging lens 1012. The converging lens 1012 is configured to make the converged second light beam 105 have a convergence angle of not more than 50 degrees. Exemplarily, the convergence angle of the second light beam 105 is selected to be, for example, 20-40 degrees or 25-35 degrees. In some cases, the convergence angle of the second light beam 105 can be selected to be, for example, approximately 30 degrees. Of course, the converging element 101 can be configured with more optical elements, such as adding an optical lens and a collecting lens 1011 and a converging lens 1012 to realize a multi-stage convergence of the divergence angle of the first light beam 104, and adding a lens element for shaping and eliminating phase differences of the first light beam 104, etc., which is not limited in this application. In these embodiments, the converging element 101 includes a multi-stage lens element that converges the first light beam 104 step by step, which can improve the collection efficiency of the first light beam 104 emitted by the light-emitting element 100, so that the third light beam 106 subsequently emitted through the light-homogenizing element 102 has a higher brightness.

[0047] The light homogenizing element 102 includes a light guiding portion 1020, which is configured to be made of, for example, glass or resin material. The light guiding portion 1020 has a light incident surface 1021 and a light emitting surface 1022. The second light beam 105 from the converging element 101 is coupled into the light guiding portion 1020 via the light incident surface 1021 and continues to propagate inside the light guiding portion 1020. While propagating the second light beam 105, the light guiding portion 1020 homogenizes the second light beam 105 to homogenize the second light beam 105 into a third light beam 106 with uniform light distribution. The second light beam 106 is emitted via the light emitting surface 1022. The third light beam 106 forms a preset light spot having a shape matching that of the light emitting surface 1022 at the light emitting surface 1022 of the light guiding portion 102. The preset light spot has a uniform light distribution due to the homogenizing effect of the light guiding portion 102. Therefore, after the preset light spot is imaged onto the object 2 to be measured via the imaging element 103, it can evenly illuminate the object 2 to be measured.

[0048] In some embodiments of the present application, the light guide 1020 is configured to have an elongated structure, which propagates the second light beam 105 along its length direction, and in the process of propagating the second light beam 105, the light guide 1020 uses the inner wall of its peripheral side to internally reflect the second light beam 105 multiple times, thereby changing the light distribution of the second light beam 105 and homogenizing the second light beam 105. In some examples, the light guide 1020 is set as a light guide rod, and the light guide rod can be made of an optical medium such as glass or resin material, which has a refractive index greater than that of air. During the propagation of the second light beam 105 in the light guide rod, the light incident on the light guide 1020 at a large angle is totally internally reflected on the inner wall of the light guide rod, thereby homogenizing the second light beam 105 through multiple total internal reflections. The light guide rod can be set as a cylindrical structure, for example, and its cross-sectional shape is set as a circle or a polygon. The length of the light guide rod can be set to be not less than 10 mm to fully homogenize the second light beam 105. Considering factors such as increased light loss, increased size and cost due to excessive length of the light guide rod, the length of the light guide rod may be selected to be no more than 100 mm, or no more than 50 mm.

[0049] The side of the light guide rod is set as a polished surface, and the polished surface is obtained by a polishing process, for example. If the side of the light guide rod has a certain degree of roughness, there will be many microstructures at the interface between the light guide rod and the air. The light whose part of the existence of these microstructures is greater than the critical angle corresponding to the total reflection can also be transmitted from the side of the light guide rod through the microstructure. By polishing the side of the light guide rod, the smoothness of the side of the light guide rod is improved, the existence of microstructures is effectively reduced, which is conducive to improving the light utilization rate and uniformity.

[0050] The light incident surface of the light guide rod and / or the light exit surface of the light guide rod are also set as polished surfaces. When the light incident surface of the light guide rod and / or the light exit surface of the light guide rod have a certain degree of roughness, the light incident surface and / or the light exit surface have many microstructures. Since the light guide rod and the air are optical media with different refractive indices, the presence of these microstructures will change the angle distribution of the second light beam 105 incident on the inside of the light guide rod and / or the third light beam 106 emitted through the light exit surface of the light guide rod, resulting in a decrease in the uniformity of the third light beam 106 emitted through the light exit surface of the light guide rod. Therefore, by setting the light incident surface and / or the light exit surface of the light guide rod as polished surfaces, the uniformity of the third light beam 106 emitted through the light exit surface of the light guide rod can be improved.

[0051] The imaging element 103 is used to receive the third light beam 106 emitted from the light homogenizing element 102, and to image the preset light spot of the third light beam 106 at the light exit surface 1022 of the light homogenizing element 102 onto the object 2 to be measured. The imaging element 103 is configured to image the preset light spot onto the object 2 to be measured at a predetermined magnification. For example, the preset magnification can be set to one, that is, the preset light spot is imaged onto the object 2 to be measured at the same ratio. The preset magnification can also be greater than one or less than one, so that the light spot imaged onto the object 2 to be measured has a size that matches the tested area of ​​the object 2 to be measured. The imaging element 103 can be selected as an imaging lens, such as a telecentric lens.

[0052] In some embodiments of the present application, the imaging element 103 is configured to change the traveling direction of the third light beam 106 so as to Figure 1 For example, Figure 1 The third light beam 106 emitted from the light homogenizing element 102 is incident on the imaging element 103 from the horizontal direction, and the imaging element 103 changes the direction of the third light beam 106 to be incident downward on the object 2 to be measured below, so that the space can be reasonably used and the overall size can be reduced. It should be noted that in different scenarios, the direction of the third light beam 106 incident on the imaging element 103 and the direction of the third light beam 106 after being changed by the imaging element 103 are not necessarily limited to Figure 1 The example given in .

[0053] The above is a detailed description of the various components of the light source device of the embodiment of the present application. Figure 1The working principle of the light source device of the embodiment of the present application is generally introduced: when working, the light-emitting element 100 emits a first light beam 104 with a predetermined divergence angle, the converging element 101 collects the first light beam 104 and converges the first light beam 104 into a second light beam 105 with a predetermined convergence angle, so as to couple the second light beam 105 into the light homogenizing element 102, and the second light beam 105 is homogenized by the light homogenizing element 102 during the internal propagation of the light homogenizing element 102, and then the third light beam 105 emitted through the light emitting surface 1022 of the light homogenizing element 102 forms a preset light spot (with uniform light distribution) at the light emitting surface 1022, the imaging element 103 guides the third light beam 105 from the light homogenizing element 102 to the object 2 to be measured, and images the preset light spot formed by the third light beam 105 on the light emitting surface 1022 of the light homogenizing element 102 onto the object 2 to be measured, and then the light spot projected onto the object 2 to be measured maintains the uniformity at the light emitting surface 1022 of the light homogenizing element 102.

[0054] In some embodiments, the converging element 101 is configured to include at least two optical elements, which gradually change the divergence angle of the first light beam 104 emitted by the light-emitting element 100, thereby improving the collection efficiency of the first light beam 104, so that the third light beam 106 finally guided to the object to be measured 2 has a higher brightness, thereby making the light beam irradiated on the object to be measured 2 have the advantages of being both bright and uniform.

[0055] Continue to refer to Figure 1 , the embodiment of the present application also provides a lighting device, such as Figure 1 The lighting device is used to project a detection light beam to the object 2 to be measured. The detection light beam illuminates the surface of the object 2 to be measured and is reflected or scattered from the surface of the object 2 to be measured. By collecting the detection light beam reflected or scattered by the surface of the object 2 to be measured, the image information of the object 2 to be measured is obtained, thereby realizing the detection of the object 2 to be measured.

[0056] In some embodiments, the lighting device includes the light source device as described above, and the light source device, for example, serves as the optical core of the lighting device, and is used to emit a third light beam 106 having a preset light spot to form a uniform light spot on the object 2 to be measured. It can be understood that the third light beam 106 here can be used as a detection beam of the lighting device. The lighting device also includes a carrier (not shown in the figure), which is used to, for example, fix, adjust, and support the light source device, so that the light source device is installed in a specific space and stably completes the function of projecting the third light beam 106.

[0057] The present application also provides a detection system, which is used for machine vision detection, for example, to detect defects, labels, appearance, etc. of the object 2 to be detected. Figure 1The detection device of the embodiment of the present application includes an illumination device and a detection device, wherein the illumination device includes the light source device 10 as described above, the light source device 10 projects a third light beam 106 onto the object 2 to be detected as a detection light beam, and realizes a uniform light spot on the object 2 to be detected, and the third light beam 106 returned from the object 2 to be detected is collected by the detection device, so as to obtain image information of the object 2 to be detected according to the third light beam 106, and the image information includes, for example, defect information, label information, appearance information, etc. of the object 2 to be detected. In the embodiment of the present application, since the light spot formed by the detection light beam projected by the illumination device on the object 2 to be detected has good uniformity, the image information of the object 2 to be detected that can be collected has better contrast, so the detection accuracy and efficiency can be improved.

[0058] In some embodiments of the present application, the detection device includes an image acquisition device 30, and the image acquisition device 30 is used to collect the third light beam 106 returned by the object 2 to be detected. Figure 1 As shown, in some examples, the image acquisition device 30 and the object 2 to be measured are respectively arranged on both sides of the imaging element 103, and the imaging element 103 receives the third light beam 106 and guides the third light beam 106 to the object 2 to be measured on one side of the imaging element 103, and the third light beam 106 returned from the object 2 to be measured is collected by the image acquisition device 30 through the imaging element 103. The imaging element 103 can be set as an optical element with a predetermined transmission and reflection ratio for the third light beam 106, so that part of the third light beam 106 can be transmitted and part of the third light beam 106 can be reflected. The image acquisition device 30 can be set as a CCD camera, for example, and the CCD camera has a field of view 31 that at least partially covers the object 2 to be measured and the returned third light beam 106. It should be noted that, in different embodiments, the positions of the image acquisition device 30, the object under test 2 and the imaging element 103 can be changed. For example, at least two of the three can be arranged in a manner with a relative tilt angle. For another example, the imaging element 103 and the image acquisition device 30 can be arranged on both sides of the object under test 2, respectively. At this time, after the third light beam 106 guided by the imaging element 103 is irradiated onto the object under test 2, at least part of the third light beam 106 can be incident on the image acquisition device 30 on the other side of the object under test 2 from the surrounding of the object under test 2 or through the object under test 2.

[0059] The above is only an implementation method of the present invention. It should be pointed out that a person skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements are all within the protection scope of the present invention.

Claims

1. A light source device, characterized in that: include: A light emitting element, configured to emit a first light beam, wherein the first light beam has a preset divergence angle; A converging element, used for converging the first light beam into a second light beam, wherein the second light beam has a preset converging angle; A light homogenizing element, comprising a light homogenizing portion, the light homogenizing portion having a light incident surface and a light exiting surface, the light incident surface being used to receive the second light beam, the light homogenizing portion being used to homogenize the second light beam into a third light beam, the light exiting surface being used to emit the third light beam, wherein the third light beam has a preset light spot on the light exiting surface; as well as An imaging element is used to guide the third light beam and image the preset light spot onto the object to be measured.

2. The light source device according to claim 1, characterized in that: The light emitting element comprises at least two LED light emitting chips, and the at least two LED light emitting chips are used to emit light beams of at least two different wavelengths.

3. The light source device according to claim 1, characterized in that: The light emitting element comprises: an excitation light source, configured to emit excitation light; and The wavelength conversion element receives the excitation light and converts at least a portion of the excitation light into a converted light having a wavelength different from that of the excitation light.

4. The light source device according to claim 1, characterized in that: The first light beam has a divergence angle of not less than 120 degrees.

5. The light source device according to claim 1, characterized in that: The convergence angle of the second light beam is no greater than 50 degrees.

6. The light source device according to claim 1, characterized in that: The converging element comprises: A collecting lens, used for collecting the first light beam and reducing the divergence angle of the first light beam; The converging lens receives the first light beam from the collecting lens and converges the first light beam into a converging light beam.

7. The light source device according to claim 1, characterized in that: The light homogenizing element includes a light guide rod, which is used to propagate the second light beam and internally reflect the second light beam multiple times in a traveling direction of the second light beam.

8. The light source device according to claim 7, characterized in that: The length of the light guide rod is not less than 10 mm.

9. A lighting device, characterized in that: The invention comprises the light source device according to any one of claims 1 to 8.

10. A detection system, characterized in that: include: An illumination device for projecting illumination light onto the object to be measured, wherein the illumination device comprises a light source device as claimed in any one of claims 1 to 8; as well as The detection device receives the illumination light from the object to be detected and obtains the image information of the object to be detected according to the illumination light.

Images