An automatic detection device for an optical module

Abstract

The present invention relates to an automatic detection device for an optical module. The device includes a working robot, an angle positioning camera, a detection device, a controller and a scattering projection plate. The controller is used to control the working robot, the angle positioning camera and the detection device. The scattering projection plate is located on the optical path of the optical module. The working robot is used to adjust the position and pose of the optical module with the assistance of the angle positioning camera. The detection device is used to detect the optical performance of the optical module. The present invention uses an angle positioning camera and a working robot to realize the loading and unloading of the optical module, its angle correction, positioning test, etc., avoiding problems such as inaccurate position and low efficiency caused by manual operation, and avoiding manual contamination of the optical module, ensuring the test accuracy. By using a scattering projection plate and the height of the projection plate can be adjusted according to the test requirements, the quality test of the speckle pattern is more accurate, and at the same time, the volume of the entire device is reduced.

Description

Technical Field

[0001] The present invention relates to the field of optical detection of optical modules, and particularly to an automatic detection device for optical modules. Background Art

[0002] Optical modules are widely used in fields such as mobile phones, robots, and various intelligent vision hardware markets, and include infrared modules, RGB modules, projection modules, etc. Before these optical modules are put on the market, they must undergo a series of strict performance tests. For example, for an infrared structured light projection module, tests such as optical power, wavelength, and speckle quality are carried out. By outputting the results of these tests, qualified optical modules can be screened out.

[0003] However, there are few records of optical detection devices for testing optical power, wavelength, speckle quality, etc. in the prior art, and there is still a lack in terms of automation. Manual loading and unloading and product sorting are required, which are prone to human errors. At the same time, fixing the optical module to be tested on the fixture is also prone to position deviation, hard contact tilt, etc., thus affecting the accuracy of detection. Therefore, the optical detection device needs to be improved in terms of detection efficiency, accuracy, etc. Summary of the Invention

[0004] In order to solve the deficiencies of the prior art in terms of detection efficiency, accuracy, etc., the present invention proposes an automatic detection device for optical modules.

[0005] The automatic detection device for optical modules includes: an operation robot, an angle positioning camera, a detection device, a controller, and a diffusive projection plate. The controller is used to control the operation robot, the angle positioning camera, and the detection device; the diffusive projection plate is located on the optical path of the optical module;

[0006] The operation robot is used to adjust the pose of the optical module with the assistance of the angle positioning camera;

[0007] The detection device is used to detect the optical performance of the optical module.

[0008] In some embodiments of the present invention, the automatic detection device further includes a barcode reader, which is connected to the controller and controls the scanning head of the barcode reader to align with the identification code on the optical module.

[0009] In some embodiments of the present invention, the automatic detection device further includes an upper machine plate. The operation robot, the angle positioning camera, the detection device, and the controller are all located on the upper machine plate; the diffusive projection plate is located below the upper machine plate, forming a lower machine plate.

[0010] In some embodiments of the present invention, the detection device includes one or more detection instruments such as a power meter, a spectrometer, a projection pattern test device, etc.

[0011] In some embodiments of the present invention, the work robot includes a robotic arm, an identification camera, and a vacuum pressure sensor, all of which are connected to the controller.

[0012] In some embodiments of the present invention, a position-in-place power-on sensor and a flexible circuit board clamping cover are provided on the robotic arm; the position-in-place power-on sensor has a power-on proximity switch, and the power-on proximity switch is connected to the flexible circuit board clamping cover.

[0013] In some embodiments of the present invention, the robotic arm has a vacuum adsorption part, and the vacuum adsorption part also has a semiconductor cooler.

[0014] In some embodiments of the present invention, the projection pattern testing device includes a center and local acquisition camera, a calibration camera, and a peripheral acquisition camera; the center and local acquisition camera, the calibration camera, the peripheral acquisition camera, and the optical module are located on the back of the upper machine board and are all located above the scattering projection board.

[0015] In some embodiments of the present invention, the optical module, the center and local acquisition camera, the calibration camera, and the peripheral acquisition camera are on the same horizontal plane.

[0016] In some embodiments of the present invention, the scattering projection board includes glass or an aluminum plate, and a white cardboard is pasted on its surface or white latex paint is sprayed, and the roughness is 0.05 - 0.1 mm.

[0017] The beneficial effects of the present invention are as follows:

[0018] By using an angle positioning camera and a work robot, the loading and unloading of the optical module, its angle calibration, positioning test, etc. are realized, avoiding problems such as inaccurate position and low efficiency in manual operation, and avoiding manual contamination of the optical module, ensuring the test accuracy. In view of the characteristic that the speckle of structured light changes in the depth direction, a scattering projection board is used to display the speckle pattern at a specific depth, and the height of the projection board can be adjusted according to the test requirements, so that the quality test of the speckle pattern is more accurate, and at the same time, the volume of the entire device is reduced. In some embodiments of the present invention, by using a barcode numbering, the measured speckles and product numbers are put into one-to-one correspondence, further improving the test efficiency and the qualified rate.

[0019] Other advantages and beneficial effects in some embodiments of the present invention will be further described through examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of an automatic detection device according to an embodiment of the present invention.

[0021] Figure 2It is a schematic structural diagram of a working robot according to an embodiment of the present invention.

[0022] Figure 3 It is a schematic structural diagram of a robotic arm according to an embodiment of the present invention.

[0023] Figure 4 It is a schematic structural diagram of a projection pattern testing device according to an embodiment of the present invention.

[0024] Figure 5 It is a schematic flowchart of an embodiment of the present invention. Detailed implementation manners

[0025] The present invention will be described in detail below with reference to the accompanying drawings through specific embodiments to better understand the present invention. However, the following embodiments do not limit the protection scope of the present invention. In addition, it should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. The components shown in the drawings only include those related to the present invention, rather than being drawn according to the number, shape, and size of the components in actual implementation. The shape, quantity, and ratio of each component in actual implementation can be changed according to needs, and the layout form of its components may also be more complex.

[0026] It should be noted that although the projection module detected in the embodiments of the present invention refers to an infrared structured light projection module, the detection device in the embodiments can also be used to detect any other different types of optical modules. The following only takes a structured light projection module that projects a speckle pattern as an example for illustration.

[0027] Figure 1 It is a schematic structural diagram of an automatic detection device according to an embodiment of the present invention. The automatic detection device includes an upper machine plate 107 and a lower machine plate 108. A series of detection components and a controller are provided on the upper machine plate 107 (in this embodiment, the controller is implemented by a computer 106, but in some embodiments, the controller can be a separate component independent of the computer). The lower machine plate 108 is a scattering (diffuse) projection plate. Through scattering, the camera located on the upper machine plate 107 can capture the speckle pattern for analysis, so that the detection of the speckle can be carried out on the upper machine plate 107, thus reducing the volume of the entire device. The upper machine plate 107 specifically includes a working robot 101, a material tray 102, a barcode reader 103, an angle positioning camera 104, a detection device 105, and a computer 106, etc.

[0028] The operation robot 101 is the automated core component of the device, which is used to realize the loading and unloading of the optical module to be tested and adjust the position and pose of the optical module to be tested. The material tray 102 can accommodate multiple optical modules, such as a projection module with a size of approximately 5*5*5 mm. Each module is attached with an identification code with a size of approximately 3*4 mm. In this embodiment, these identification codes are two-dimensional codes, and these identification codes are read by the code reader 103 and output the corresponding numbers. The identification code on each optical module to be tested is unique and corresponds to different numbers. The code reader 103 can automatically scan and obtain these unique numbers, so as to accurately know the optical performance of each optical module to be tested. Once these optical modules are put into specific products for use, the information of the optical modules used in the products can be mastered, which is convenient for subsequent tracking and maintenance of these products.

[0029] Since each optical module to be tested has a unique number, which can be read by the code reader 103 during the detection process, in this way, the optical performance detection of the optical module to be tested changes from simply qualified (OK) or unqualified (NG) to the recording of optical performance characteristics, that is, the corresponding recording of the performance of the optical module to be tested one by one. For example, when a certain performance is detected as NG, the optical module can be returned to the processing process, and after further processing of the NG item, the detection can be continued. At this time, the computer 106 will retrieve its historical detection results according to the number, and only need to detect the NG item again, which greatly improves the detection efficiency and the yield rate.

[0030] The angle positioning camera 104 can assist the operation robot in adjusting the position and pose of the optical module to be tested. In one embodiment, the angle positioning camera 104 is used to take pictures of the angle of the optical module sucked by the operation robot 101. When the picture shows that the angle of the sucked optical module has changed compared with the preset angle, the controller will control the operation robot 101 to automatically correct the angle of the sucked optical module, so that the detection angle of the optical module to be tested is always consistent with the preset angle, avoiding inaccurate detection caused by the change of the position of the optical module to be tested. The fixing method of the angle positioning camera 104 is not limited to the fixing method shown in the figure.

[0031] The detection device 105 is used to detect the optical performance of the optical module. In one embodiment, the detection device 105 is composed of one or more detection instruments such as a light power meter, a spectrometer, a projection pattern testing device, etc. The light power meter is used to test the light power of the optical module, the spectrometer is used to test the emission wavelength of the optical module, and the smaller the wavelength change, the more stable the optical module. The projection pattern testing device is used to detect the light coding pattern (speckle) emitted by the optical module, such as the speckle area, density, and the size of a single speckle projected by the structured light projection module, etc., and make one-to-one records in combination with the unique identification code on the optical module to be tested read by the barcode scanner 103.

[0032] The operation robot 101 sequentially passes by the material tray 102, the barcode scanner 103, and the angle positioning camera 104, and finally sends the optical module to be tested to the corresponding test position of the detection device 105 for corresponding performance detection. The computer 106 processes the system to output the detection result. The entire detection process and analysis algorithm are controlled by the computer 106, and its process is as Figure 5 shown. In one embodiment, the material tray 102 can place 25 - 50 materials at a time. The material tray 102 includes a qualified (OK) tray, a non - qualified (NG) tray, and a tray for materials to be tested. Generally, 2 - 3 OK trays are set according to different wavelength bands emitted by the optical module to be tested for classified placement. When the operation robot 101 sucks the optical module to be tested from the tray for materials to be tested and completes the optical performance detection, if the detection result shows qualified, the operation robot 101 will return the optical module to the OK tray, otherwise it will return it to the NG tray, thus quickly completing the classification of materials. And during the whole detection process, the operation robot 101 sucks, detects, classifies, and places the dishes, avoiding adverse effects such as soiling and damage to the materials caused by manual operation.

[0033] In one embodiment, if it is known through subsequent detection after scanning the code that a certain index of an optical module to be tested is unqualified, then after the robot 101 returns it to the NG tray, it will be further allocated to the corresponding processing procedure to process and improve the unqualified optical module. When it enters the detection stage again, the computer 106 can call out its historical detection results and control the detection device to only detect its unqualified detection items.

[0034] Figure 2Schematic structural diagram of a working robot according to an embodiment of the present invention. The working robot includes a robotic arm 201, an identification camera 202, a vacuum pressure sensor 203, a controller 204, etc. Among them, the robotic arm 201 is used to pick up the optical module to be tested from the material tray. The identification camera 202 is used on the one hand to take pictures to identify whether there is material on the material tray, so as to avoid the robotic arm 201 colliding with the material tray hard and causing damage to the robotic arm 201. If the robotic arm 201 touches an empty material tray, it may damage the internal components of the working robot, resulting in inaccurate subsequent detection. On the other hand, the identification camera 202 is used to take pictures to identify the status of the OK tray and the NG tray after the detection is completed. For example, when the OK tray and the NG tray are full, it prompts to replace the empty OK tray and NG tray, so that the robotic arm 201 can accurately discharge the material and avoid collisions caused by stacking between the modules. When the identification camera 202 takes a picture above the material tray to be tested and the system identifies that the material tray to be tested is an empty tray or there is not much remaining material according to the picture result, it will prompt to replace the material tray to be tested through the computer. The vacuum pressure sensor 203 is used to judge whether the robotic arm 201 has successfully picked up the material. If the robotic arm 201 fails to pick up the material, it will try to pick up the material for the second time. If the second pick-up fails, the robotic arm 201 will pick up the next material to be tested in sequence for detection, and the remaining materials to be tested that have not been successfully picked up will be put into the next material tray for further detection. In this way, there is no need for manual intervention during the material picking process, greatly saving the detection time. The controller 204 is used to control a series of actions of the working robot, etc. In this embodiment, the misidentification rate during the system operation is less than 5%.

[0035] Figure 3 Schematic structural diagram of the robotic arm according to an embodiment of the present invention. The robotic arm shown in the figure further includes a in-place power-on sensor 301, a flexible printed circuit (FPC) clamp cover 302, etc. In the figure, 303 is the optical module to be tested adsorbed.

[0036] After a part of the robotic arm connected to the vacuum pressure sensor adsorbs the optical module 303 to be tested, the FPC cover 302 is driven to cover the end part of the optical module 303 to be tested. Among them, the optical module 303 to be tested includes a lens part for projecting light beams and a flexible printed circuit board (PCB) part for power supply. After the FPC cover is driven to be buckled with the PCB part of the optical module 303 to be tested, the module can be lit when the FPC cover is powered on. The in-place power-on sensor is located beside the PCB of the adsorbed optical module 303 to be tested. The in-place power-on sensor has a power-on proximity switch. When the in-place power-on sensor determines through the proximity sensing principle that the optical module 303 to be tested has reached the corresponding test position of the detection device, where the test position refers to the position where the optical module 303 to be tested reaches the positions where the optical power meter, spectrometer, projection pattern test device, etc. are located, the power-on proximity switch powers on the FPC cover and thus lights up the optical module 303 to be tested, so that the laser emitter projects structured light for optical performance testing.

[0037] In one embodiment, the robotic arm has a vacuum adsorption part. The robotic arm uses vacuum to adsorb the optical module 303 to be tested. The adsorption method is to adsorb from the back side avoiding the lens of the optical module 303 to prevent dirt on the light-emitting lens of the optical module 303 from affecting the detection accuracy. In addition, the adsorption part of the robotic arm for adsorbing the optical module 303 to be tested also has a thermoelectric cooler (TEC) to control the optical module 303 to be tested to always maintain within a constant detection temperature range, avoiding the temperature rise caused by the heat generation of the optical module 303 to be tested during the detection process and affecting the detection accuracy. After the robotic arm carries the optical module 303 to be tested through the barcode reader, it controls the FPC cover to cover the PCB part of the optical module 303 to be tested, and then the angle positioning camera takes pictures of the adsorbed optical module 303 to be tested. If the system identifies through the pictures that the angle of the optical module 303 has changed, it controls the working robot to perform angle correction on the adsorbed optical module 303 to be tested. Since the FPC cover will cause vibrations, pulling, etc. to the optical module 303 to be tested when covering the PCB of the optical module 303 to be tested, the FPC cover needs to be buckled with the PCB part of the optical module 303 to be tested before correcting the angle to ensure that the position of the optical module 303 to be tested will not change again, avoiding inaccurate detection caused by the change of the adsorption angle of the optical module 303 to be tested.

[0038] Figure 4 is a schematic structural diagram of a projection pattern test device according to an embodiment of the present invention, as Figure 4As shown in the figure, the projection pattern (speckle) testing device is composed of a projection module 401 to be tested, a central and local acquisition camera 402, a calibration camera 403, a peripheral acquisition camera 404, a projection board 405, etc. Among them, the central and local acquisition camera 402, the calibration camera 403, the peripheral acquisition camera 404, and the projection module 401 to be tested are located on the back of the upper machine board and are all above the projection board 405. The projection module 401 to be tested projects a speckle pattern downward through the hole positions on the front of the upper machine board. In one embodiment, the projection module 401 to be tested, the central and local acquisition camera 402, the calibration camera 403, and the peripheral acquisition camera 404 are on the same horizontal plane. The central and local acquisition camera 402 is used to acquire the speckle pattern projected by the projection module. The calibration camera 403 is used to correct the distortion generated during camera shooting. The peripheral acquisition camera 404 is used to acquire the speckle pattern at the edge part of the projection board 405 to prevent inaccurate detection caused by the central and local acquisition camera 402 being unable to acquire all the speckle patterns on the projection board 405. The above settings adopt the calculation principle of the structured light depth imaging system, which simplifies the detection and analysis algorithm and also ensures the accuracy of the detected speckle pattern quality. In this embodiment, a specific reflective material is coated on the projection board 405, and the reflective type is used to detect the speckle. That is, after the projection module 401 to be tested projects a speckle pattern, the central and local acquisition camera 402, the calibration camera 403, and the peripheral acquisition camera 404 capture the light beam reflected back through the projection board 405 to analyze the speckle pattern situation. Thus, from the perspective of the depth imaging principle of practical applications, the acquisition camera can always capture the actual situation of the speckle pattern from the front of the projection board 405.

[0039] In this embodiment, the details of the projection board 405 are as follows: Projection board material: glass or aluminum plate; Surface treatment: stick white cardboard or spray white latex paint; Roughness: 0.05 - 0.1 mm; Distance from the module height: 700 mm, board length, width and thickness: 1400 * 1200 * 12 mm (when the maximum field of view); According to the module test requirements, the adjustable range of the height of the projection board is 400 - 800 mm. The projection board 405 designed in this way can scatter the structured light speckles into the fields of view of the central and local acquisition camera 402, the calibration camera 403, the peripheral acquisition camera 404, etc., ensuring clarity and no distortion, and facilitating photographing and detection.

[0040] The process of the existing manually operated feeding detection equipment generally includes: manually picking up materials and placing them in the fixture (1 - 2 materials can be placed), manually covering the fixture cover, entering the barcode scanner for scanning, entering the integrating sphere for corresponding performance testing, and the fixture ejecting and manually taking out the materials and sorting them on the tray. Different from the existing detection scheme, the process of automatically detecting the optical properties of the material to be tested in the present invention includes (see details in Figure 5 ):

[0041] S1: Start the operation robot. The recognition camera takes a picture above the material tray. The system then identifies whether there is material on the material tray. If the tray is empty, it prompts to replace it with a material tray loaded with the material to be tested.

[0042] S2: After determining that there is material on the material tray, the operation robot opens the FPC clamp cover. The robotic arm starts to adsorb the material to be tested. The vacuum pressure sensor determines that the robotic arm has successfully adsorbed the material to be tested and proceeds to the next step. Otherwise, the robotic arm makes a second adsorption attempt. If the second adsorption fails, the robotic arm directly adsorbs the next material to be tested.

[0043] S3: As the operation robot adsorbs the material to be tested and passes by the barcode reader, after reading the material number corresponding to the identification code on the material to be tested, it closes the FPC clamp cover. The angle positioning camera takes a picture. The system determines whether the angle of the adsorbed material to be tested has changed. If so, the operation robot automatically corrects the angle of the material to be tested; (i.e., Figure 5 the secondary positioning and photographing in

[0044] S4: The in-position power-on sensor on the operation robot determines whether the material to be tested has entered the test position. If so, it powers on the FPC clamp cover and lights up the material to be tested, and starts tests such as optical power, wavelength, and speckle tests.

[0045] S5: The computer outputs the test results. If the test results are qualified, the system controls the operation robot to place the tested material into the OK tray. Otherwise, it places it into the NG tray. Repeat steps S1 - S5 until all materials to be tested are detected and classified.

[0046] The above detection process needs to be carried out in a closed environment with good light-shielding performance. This automatic detection device can be equipped with two or more operation robots to perform detection and classification simultaneously, thereby further improving the detection efficiency.

[0047] Different from the prior art, the embodiment of the present invention provides an automatic detection device. This device is provided with an operation robot, a material tray, a barcode reader, an angle positioning camera, and a detection device, etc. The recognition camera is paired with a vacuum pressure sensor, an in-position power-on sensor, etc. in the operation robot, which can determine whether the operation robot has successfully picked up the material and whether it has reached the test position, etc. During the entire detection process, the operation robot sequentially passes by the material tray, the barcode reader, and the angle positioning camera, and finally sends the material to be tested to the corresponding test position of the detection device for corresponding performance detection, without manual participation in the detection process, achieving the detection requirements of automation, high efficiency, and high precision.

[0048] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several equivalent substitutions or obvious variations can be made, and as long as the performance or use is the same, they should all be regarded as falling within the protection scope of the present invention.

Claims

1. An automatic optical module detection device, characterized in that, include: An operating robot, an angle positioning camera, a detection device, a controller and a scattering projection board, wherein the controller is used to control the operating robot, the angle positioning camera and the detection device; the scattering projection board is located on the optical path of the optical module; The working robot is used to adjust the position and posture of the optical module with the assistance of the angle positioning camera; An upper machine plate, on which the working robot, the angle positioning camera, the detection device, and the controller are all located; the scattering projection board is located below the upper machine plate, forming a lower machine plate; The detection device is used to detect the optical performance of the optical module; The detection device comprises a projection pattern testing device, which comprises a central and local acquisition camera, a correction camera, and a peripheral acquisition camera; the central and local acquisition camera, the correction camera, the peripheral acquisition camera and the optical module are located on the back of the upper machine plate and are all located above the scattering projection plate; the central and local acquisition camera is used to acquire the speckle pattern projected by the optical module, the correction camera is used to correct the distortion generated when the camera is shooting, and the peripheral acquisition camera is used to acquire the speckle pattern at the edge of the projection plate to prevent the central and local acquisition cameras from failing to acquire all the speckle patterns on the projection plate and causing inaccurate detection.

2. The optical module automatic detection device according to claim 1, characterized in that: It also includes a code reader connected to the controller to control the scanning head of the code reader to align with the identification code on the optical module.

3. The optical module automatic detection device according to claim 1, characterized in that: The detection device also includes one or more detection instruments such as an optical power meter and a spectrometer.

4. The optical module automatic detection device according to claim 1, wherein: The operating robot includes a mechanical arm, a recognition camera, and a vacuum pressure sensor, all of which are connected to the controller.

5. The optical module automatic detection device according to claim 4, characterized in that: The mechanical arm is provided with an in-position power-on sensor and a flexible circuit board clamping cover; the in-position power-on sensor has a power-on proximity switch, and the power-on proximity switch is connected to the flexible circuit board clamping cover.

6. The optical module automatic detection device according to claim 5, characterized in that: The mechanical arm is provided with a vacuum adsorption part, and the vacuum adsorption part is also provided with a semiconductor refrigerator.

7. The optical module automatic detection device according to claim 1, wherein: The optical module, the central and local acquisition cameras, the correction camera, and the peripheral acquisition cameras are on the same horizontal plane.

8. The optical module automatic detection device according to claim 1, wherein: The scattering projection board comprises a glass or aluminum board, the surface of which is pasted with white cardboard or sprayed with white latex paint, and the roughness is 0.05-0.1 mm.

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