TW202405412A - Automatic optical inspection equipment for automatically correcting light source including a light source module, a camera module, a photoelectric sensor, and an information processing module - Google Patents

Abstract

The invention relates to automatic optical inspection equipment that can automatically correct a light source, which includes a light source module, a camera module, a photoelectric sensor, and an information processing module. The light source module can emit light toward an object to be tested; the camera module is used for receiving the light source and image from the object to be tested; the photoelectric sensor can be located in front of or behind one lens of the camera module, and after receiving the light source from the object to be tested, a corresponding electronic signal is generated; the information processing module can receive the electronic signal from the photoelectric sensor, and can determine that the brightness value represented by the electronic signal is different from the preset brightness value, so as to automatically adjust the light intensity emitted by the light source module, so that the brightness value represented by the adjusted light intensity can be the same or substantially the same as the preset brightness value.

Description

Automatic optical inspection equipment for automatic light source correction

The present invention relates to automatic optical inspection equipment, and in particular, to an automatic optical inspection equipment that achieves a correction effect by adjusting the brightness of a real light source.

Press, with the complexity of various electronic components or modules and the large number of items that must be inspected one by one, the traditional manual visual inspection (Visual Inspection) can no longer bear the load. Therefore, the industry generally uses automatic optical inspection (Automated Optical Inspection). Automated Optical Inspection (AOI) equipment is used to inspect various electronic components or modules to completely overcome the fatigue caused by inspection personnel performing visual inspections for a long time, thereby greatly improving inspection efficiency and being able to detect detected Various types of defects and their degrees are quantified with relevant data, which can be used as a strong basis for improving various related processes in the future.

Following on from the above, AOI equipment uses optical instruments to obtain the surface condition of the finished product, and then uses computer image processing technology to detect defects such as foreign objects or pattern abnormalities. Among them, AOI equipment can be roughly divided into front-illuminated light sources, back-illuminated light sources and Different lighting methods such as side-illuminated light sources can meet different inspection needs. At the same time, through good light source design, the success rate of automated computer vision inspection can be improved. However, in actual use, since each AOI equipment has machine differences, such as differences in light sources/optical paths/optical lengths, etc., therefore, if the industry sets each AOI equipment with the same parameters, the result will be Different imaging results.

In view of this, how can the industry obtain the same or substantially the same image when calibrating each AOI equipment without being affected by machine differences, thereby effectively improving the detection performance and accuracy of the object to be tested? , that is, it has become an important issue that many industry players in the electronics industry are still working hard to study and urgently want to solve. It is also an important issue that the present invention intends to discuss here.

In view of the fact that there is still room for improvement in the existing AOI equipment, the applicant adheres to the research spirit of excellence and, after a long period of hard research and experiments, finally developed an automatic optical inspection equipment of the present invention that can automatically correct the light source. With the advent of the present invention, a better correction method can be provided to the industry.

One object of the present invention is to provide an automatic optical inspection equipment that can automatically correct the light source, including a light source module, a camera module, a photoelectric sensor and an information processing module, wherein the light source module can Emit light toward an object to be measured; the camera module is used to receive the light source and image from the object to be measured; the photoelectric sensor can be located in front or behind one of the lenses of the camera module, and after receiving the The light source from the object to be measured generates a corresponding electronic signal; the information processing module can receive the electronic signal from the photoelectric sensor, and can determine that the brightness value represented by the electronic signal is different from the In the case of a preset brightness value, the light intensity emitted by the light source module is automatically adjusted so that the brightness value represented by the adjusted light intensity can be the same or substantially the same as the preset brightness value. In this way, the automatic optical The inspection equipment corrects the images captured by multiple automatic optical inspection equipment by adjusting the actual light intensity received by the object to be tested, and adjusts the grayscale value of the images captured by the automatic optical inspection equipment. They can all be close to the same or the difference value is very small.

Optionally, the information processing module includes a computer device and a first signal controller. The first signal controller can be connected to the computer device, and can control the intensity of light emitted by the light source module, and can also receive By receiving the light source and image from the camera module and receiving the electronic signal from the photoelectric sensor, the computer device or the first signal controller can determine that the brightness value represented by the electronic signal is different from the default value. If the brightness value is specified, the light intensity emitted by the light source module is automatically adjusted.

Optionally, the information processing module includes a computer device, a first signal controller and a second signal controller, the first signal controller can be connected to the computer device and the second signal controller respectively, and Can receive the light source and image from the camera module, the second signal controller can control the light intensity emitted by the light source module, and can also receive the electronic signal from the photoelectric sensor. The second signal controller The device can automatically adjust the light intensity emitted by the light source module when it determines that the brightness value represented by the electronic signal is different from the preset brightness value.

Optionally, the automatic optical inspection equipment further includes a mirror element located between the object under test and the lens of the camera module.

Optionally, the mirror element is a reflector, a refractor or a prism.

Optionally, the lens element is a transmission optical lens assembly.

In order to facilitate the review committee to have a further understanding of the purpose, technical features and effects of the present invention, the detailed description is as follows:

In order to make the purpose, technical content and advantages of the present invention more clear, the disclosed embodiments of the present invention will be further described in detail below in conjunction with specific implementation modes and with reference to the accompanying drawings. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification, and the present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be based on different viewpoints and applications. , various modifications and changes can be made without departing from the concept of the present invention. In addition, it should be stated in advance that the drawings of the present invention are only schematic illustrations and are not drawn according to actual dimensions. Although this article may provide examples of parameters containing specific values, it should be understood that the parameters do not need to be exactly equal to the corresponding values, but can be Approximate corresponding values within acceptable error tolerances or design constraints. In addition, unless the context clearly indicates or defines otherwise, the meanings of "a" and "the" in the present invention include the plural.

It should be understood that the embodiments used anywhere in the description of the present invention, including the use of any terms, are only illustrative and in no way limit the scope and meaning of the present invention or any terms. Likewise, the present invention is not limited to the various embodiments disclosed in the specification. Although the terms first, second, third, etc. may be used herein to describe various elements, each element should not be limited by the foregoing terms. The foregoing terms are mainly used to distinguish one element from another element and should not be used in any way. components impose no substantial limitations and should not limit the order in which the individual components may be assembled or arranged in a practical application. In addition, the directional terms mentioned in the embodiments, such as "front", "back", "left", "right", etc., are only for reference to the directions of the drawings. Therefore, the directional terms used are illustrative and not intended to limit the scope of the invention. In addition, the term "or" used in this article shall include any one or combination of more of the associated listed items depending on the actual situation.

Furthermore, the terms "substantially" or "approximately" used in this article may refer to a value within a range of deviations from a specific value that can be recognized or determined by those skilled in the art. Or the average of complex values, including taking into account certain specific errors that may occur when measuring the specific value due to the limitations of the measurement system or equipment. For example, the value mentioned substantially can include A range of ±5%, ±3%, ±1%, ±0.5%, ±0.1% and one or more standard deviations of that particular value.

The present invention is an automatic optical inspection equipment that can automatically correct the light source, and multiple automatic optical inspection equipments 1 can form an automatic optical inspection system. Different from the previous gray-scale image correction concept, the present invention detects and adjusts the real light source. (such as luminous flux, illumination, etc.) to perform correction, so that each automatic optical inspection equipment 1 receives the light source and image from the object T to be tested, and has the same or substantially the same brightness, thereby making the automatic optical inspection equipment 1 have the same or substantially the same brightness. The images captured by the optical inspection device 1 can be exactly the same or substantially the same.

In one embodiment, please refer to Figure 1. The automatic optical inspection equipment 1 includes a light source module 11, a camera module 12, a photoelectric sensor 13 and an information processing module 14. Among them, the light source module 11 can emit light toward an object T to be tested, and the camera module 12 can receive the light source and image from the object T to be tested. Furthermore, according to actual usage requirements, the light source module 11 The camera module 12 and the camera module 12 can be located on the same side of the object T (ie, front-illuminated light source), or the light source module 11 and the camera module 12 can be located on different sides of the object T (i.e., front-illuminated light source). That is, a back-illuminated light source), or the light source module 11 can be located on the side of the object T, and the light projected by the light source module 11 is nearly parallel to the plane of the object T (i.e., side illumination). (type light source), etc., in other words, as long as the light projected by the light source module 11 is enough to illuminate the predetermined position of the object T, the corresponding light source and image at the place where the object T is illuminated by the light are sufficient to be illuminated by the Just take the camera module 12 and get it.

In addition, please refer to FIG. 1 again. The camera module 12 at least includes a lens 121 and an imaging unit 122. The lens 121 can have different structures such as a single lens or multiple lenses, and can even include a lens for displacing the lens. voice coil motor and other components; the imaging unit 122 has the function of obtaining images and imaging, for example, Complementary Metal-Oxide Semiconductor (CMOS) specification or Charge Coupled Device (CCD) image sensors, image processors and other components, but are not limited to this. In addition, the camera module 12 can allow external light sources and images to fall on the imaging unit 122 through the lens 121, thereby obtaining clear (focused) images.

Furthermore, please refer to FIG. 1 again. The photoelectric sensor 13 can be located in front of the lens 121. In the position of FIG. 1, the photoelectric sensor 13 is located on the right side of the lens 121. However, in this case, In another embodiment of the invention, as shown in FIG. 2 , the photoelectric sensor 13 can be located behind the lens 121 , for example, integrated into the camera module 12 , but is not limited to this. As shown in FIG. 2 In terms of position, the photoelectric sensor 13 is located on the left side of the lens 121 . In addition, the photoelectric sensor 13 can receive the light source (such as reflection/refraction) from the object T and generate a corresponding electronic signal. In other words, as the photoelectric sensor 13 receives The intensity of the light source is different, and the electronic signals generated will also be different. In addition, a mirror element 15 can be disposed between the object T and the lens 121 of the camera module 12. Depending on the lighting method, the mirror element 15 can be a reflector, a refractor or a prism. (The aspect shown in Figure 1), or it can be a transmission optical lens group (the aspect shown in Figure 2).

Please refer to FIG. 1 again. The information processing module 14 can receive electronic signals from the photoelectric sensor 13. In this embodiment, the information processing module 14 includes a computer device 140 (including a tablet computer, Desktop computers, notebook computers and other related microcomputer products) and a first signal controller 141, but not limited to this, as long as the information processing module 14 can complete the subsequent process, whether it is a single device or multiple devices, All belong to what is called the information processing module 14 of the present invention. In addition, the first signal controller 141 is electrically connected to the computer device 140, the light source module 11, the camera module 12 and the photoelectric sensor 13 respectively, wherein the first signal controller 141 and the computer device 140 are connected to each other. They can send/receive messages to each other, receive light sources and images from the camera module 12 , and transmit the aforementioned images to the computer device 140 . The first signal controller 141 can also send light control information to the light source module 11 to control and change the light intensity emitted by the light source module 11, and the first signal controller 141 can also receive the photoelectric sensor. Electronic signal from device 13.

Continuing with the above, please refer to FIG. 1 again. In this embodiment, the first signal controller 141 can calculate the corresponding brightness value according to the electronic signal, and compares the calculated brightness value with a preset value. Compare the brightness value. When the calculated brightness value is different from the preset brightness value, the first signal controller 141 can automatically adjust the light intensity emitted by the light source module 11 according to the judgment result. For example, when the third After a signal controller 141 determines that the calculated brightness value is lower than the preset brightness value, it can increase the light intensity emitted by the light source module 11; when the first signal controller 141 determines that the calculated brightness value is When the value is higher than the preset brightness value, it can reduce the intensity of light emitted by the light source module 11 . In addition, in other embodiments of the present invention, the judgment process of the first signal controller 141 can be executed by the computer device 140, that is, the first signal controller 141 can directly transmit the electronic signal to the computer device. 140, for the computer device 140 to make a judgment and adjust the light intensity emitted by the light source module 11 through the first signal controller 141.

In addition to the information processing module 14 described in the foregoing embodiments, in another embodiment of the present invention, as shown in FIG. 2 , the information processing module 14 can be composed of at least a computer device 140, a The first signal controller 141 and a second signal controller 142 are composed of a first signal controller 141 and a second signal controller 142. The difference from the previous embodiment is that the first signal controller 141 can be electrically connected to the computer device 140, the second signal controller 142 and the second signal controller 142 respectively. Camera module 12, the second signal controller 142 can electrically connect the light source module 11 and the photoelectric sensor 13, wherein the first signal controller 141 can receive the light source and image from the camera module 12, The second signal controller can control the intensity of light emitted by the light source module 11 and receive electronic signals from the photoelectric sensor 13 . In addition, the second signal controller 142 can calculate the corresponding brightness value according to the electronic signal, and compare the calculated brightness value with a preset brightness value. When the calculated brightness value is different from the preset brightness value, If the brightness value is set, the second signal controller 142 can automatically adjust the light intensity emitted by the light source module 11 according to the judgment result.

It is worth mentioning here that the aforementioned preset brightness value refers to the light currently emitted by the light source module 11 that irradiates the object T under test. The object T under test should reflect/refract the light source. Corresponding to the light intensity, and the light source of the object T detected by the photoelectric sensor 13, the light intensity should conform to the curve change of the thick dotted line shown in Figure 3A, that is, the grayscale value of each grayscale image corresponding brightness. However, in actual situations, the light source module 11 may be affected by itself or other components or external environmental factors, causing the actual reflected/refracted light intensity (brightness) of the light source by the object T to be measured to be less than expected. The curve changes as shown by the thin solid line in Figure 3A. Therefore, the automatic optical inspection equipment 1 can automatically adjust the light intensity of the light source module 11 according to the light intensity actually detected by the photoelectric sensor 13 (from the light source of the object T), so that the photoelectric sensor 13 The light intensity actually detected by the sensor 13 can coincide with the preset brightness value (as shown in FIG. 3B ), so that the camera module 12 can obtain the light source and image after the aforementioned automatic correction.

Please refer to Figure 1 again. After each automatic optical inspection equipment 1 shoots and obtains an image (such as a grayscale image) of the object T to be tested, the object T to be tested is detected by the photoelectric sensor 13. The measured brightness should be the same or substantially the same. Therefore, the grayscale values of the grayscale images obtained by each automatic optical inspection equipment 1 should be the same or substantially the same. The main reason is that there are currently multiple machines manufactured in the same batch. Cameras, which use image sensors, image processors and other components, usually have very similar camera quality. Therefore, after using the same parameters in these cameras, as long as the brightness from the object T to be measured is the same, it should be inferred that The object T under test is under the same light intensity, so the images captured by it will be the same or substantially the same. Therefore, the automatic optical inspection equipment 1 of the present invention abandons the conventional concept of correcting gray-scale images, and instead uses the photoelectric sensor 13 to correct the light intensity received by the object T to be tested. In other words, the present invention The camera modules 12 of the automatic optical inspection equipment 1 can use the same parameter settings, and only need to correct the light intensity emitted by each light source module 11 .

Following on from the above, in the actual test, when the brightness (the intensity of light actually detected by the photoelectric sensor 13) is the same, the converted grayscale of the grayscale images captured by the two automatic optical inspection equipments 1 is The values are very close, as shown in Table 1 below: [Table 1] brightness The first automated optical inspection equipment Second automated optical inspection equipment 0 0.112446 0.07239 10 19.76917 19.95499 20 40.81377 41.17105 30 61.96928 62.43221 40 83.19742 83.78204 50 104.3767 105.1791 60 126.0003 126.537 70 147.214 147.8178 80 168.2251 169.0204 90 189.2173 190.3624 100 214.9546 215.7934 In addition, according to the results in the above table, it can be seen that the linear change of the regression analysis (Regression analysis) of the automatic optical inspection equipment 1 has a coefficient of determination (R squared) value of "0.997", which is very close to the theoretical data "1", which is better than Generally, the coefficient of determination required for AOI applications is "0.9" which is better.

To sum up, the present invention adjusts the actual light intensity generated by the light source module 11 so that the camera module 12 of each automatic optical inspection equipment 1 can receive the image of the object to be tested T with the same brightness, and thereby achieve correction effect. In addition, in another embodiment, please refer to FIG. 2 again. In addition to correcting the light intensity of the light source module 11, the second signal controller 142 can also detect the first signal controller in real time. 141 whether there is circuit power output attenuation, so that the first signal controller 141 can be immediately compensated to the normal default output power, so as to prevent the first signal controller 141 from causing the final light source module 11 to be damaged when the circuit power output is attenuated. The received power becomes smaller, resulting in negative effects such as a decrease in brightness, so that the automatic optical inspection equipment 1 can maintain normal production capacity and yield.

According to the above, the above are only preferred embodiments of the present invention. However, the scope of rights claimed by the present invention is not limited thereto. According to those who are familiar with the art, based on the technical content disclosed in the present invention, they can Equivalent changes that can be easily imagined should not depart from the scope of protection of the present invention.

[customary knowledge] without [Invention] 1: Automatic optical inspection equipment 11:Light source module 12:Camera module 121: Lens 122: Imaging unit 13: Photoelectric sensor 14:Information processing module 140:Computer equipment 141:First signal controller 142: Second signal controller 15: Mirror components T: Test object

[Figure 1] is a schematic diagram of the automatic optical inspection equipment according to one embodiment of the present invention; [Figure 2] is a schematic diagram of automatic optical inspection equipment according to another embodiment of the present invention; [Figure 3A] is a schematic diagram of the brightness curve of the automatic optical inspection equipment of the present invention before calibration; [Figure 3B] is a schematic diagram of the brightness curve of the automatic optical inspection equipment of the present invention after calibration; and [Figure 4] is a schematic diagram of regression analysis based on Table 1.

1: Automatic optical inspection equipment

11:Light source module

12:Camera module

121: Lens

122: Imaging unit

13: Photoelectric sensor

14:Information processing module

140:Computer equipment

141:First signal controller

15: Mirror components

T: Test object

Claims (6)

An automatic optical inspection equipment that can automatically correct the light source, including: A light source module is capable of emitting light toward an object to be measured; A camera module used to receive the light source and image from the object under test; A photoelectric sensor is located in front or behind one of the lenses of the camera module, and generates a corresponding electronic signal after receiving the light source from the object to be measured; and An information processing module can receive the electronic signal from the photoelectric sensor, and can automatically adjust the light source module when it is determined that the brightness value represented by the electronic signal is different from the preset brightness value. The intensity of light emitted is such that the brightness value represented by the adjusted light intensity is the same or substantially the same as the preset brightness value. The automatic optical inspection equipment as described in claim 1, wherein the information processing module includes a computer device and a first signal controller, the first signal controller can be connected to the computer device and can control the light source module The light intensity emitted by the set can also receive the light source and image from the camera module, and receive the electronic signal from the photoelectric sensor. The computer equipment or the first signal controller can determine the electronic signal. When the brightness value represented by the signal is different from the preset brightness value, the light intensity emitted by the light source module is automatically adjusted. The automatic optical inspection equipment according to claim 1, wherein the information processing module includes a computer device, a first signal controller and a second signal controller, and the first signal controller can be connected to the computer respectively. The device and the second signal controller can receive the light source and image from the camera module. The second signal controller can control the light intensity emitted by the light source module and can also receive the light source transmitted by the photoelectric sensor. The second signal controller can automatically adjust the light intensity emitted by the light source module when it determines that the brightness value represented by the electronic signal is different from the preset brightness value. The automatic optical inspection equipment according to any one of claims 1 to 3, further comprising a mirror element located between the object to be measured and the lens of the camera module. The automatic optical inspection equipment as described in claim 4, wherein the mirror element is a reflector, a refractor or a prism. The automatic optical inspection equipment as claimed in claim 4, wherein the mirror element is a transmission optical lens group.