A device for lens visual inspection

Abstract

This utility model discloses a device for visual inspection of lenses. The key technical features include a machine platform on which multiple industrial cameras for visually inspecting lens appearance and a light diffuser are placed. A feeding plate is also provided on the machine platform, holding several trays of lenses to be inspected and trays of defective lenses. The machine platform also includes a driving device for moving the feeding plate along the X and Y axes to inspect the lenses, and a suction pen for picking up defective lenses and placing them into the defective lens tray. This utility model enables automated visual inspection by moving the lenses instead of the industrial cameras, avoiding the impact of camera movement on inspection accuracy and greatly improving inspection efficiency and quality.

Description

Technical Field

[0001] This utility model relates to a visual inspection device, and more particularly to a device for visual inspection of lenses. Background Technology

[0002] Visual inspection is the use of machines to replace human eyes for measurement and judgment. It refers to the process of converting the captured target into an image signal through machine vision products and transmitting it to a dedicated image processing system. Based on pixel distribution and information such as brightness and color, the signal is converted into a digital signal. The characteristics of machine vision inspection are to improve the flexibility and automation of production, and to be used in dangerous working environments where manual operation is not suitable or where human vision is insufficient.

[0003] Current lens visual inspection generally involves first visually inspecting the surface for major defects such as dirt and foreign objects. If no problems are found with the naked eye, a secondary inspection using an industrial camera is required to detect minor defects such as assembly misalignment >0.05mm, shell scratches, and glue overflow. This process is inefficient.

[0004] Some automated visual inspection equipment also uses existing technology that involves "a stationary lens and a moving industrial camera," such as the Chinese utility model patent with patent number CN202320473553.3. Its disadvantages include poor inspection accuracy and low inspection efficiency.

[0005] The information disclosed in the background section is only for enhancing the understanding of the background of this utility model, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a device for visual inspection of lenses, which can perform automated visual inspection of processed lenses, thus solving the problem of low efficiency caused by manual screening in the prior art.

[0007] This utility model is achieved through the following technical solution.

[0008] A device for visual inspection of lenses, characterized in that: it includes a machine table 1, on which are placed a plurality of industrial cameras 3 for visual inspection of lens appearance and a light-diffusing cover 4; a feeding plate 5 is also provided on the machine table 1, on which are mounted a plurality of lens trays 6 to be inspected and defective lens trays 7; a driving device 2 for driving the feeding plate 5 to move along the X-axis and Y-axis to inspect lenses; and a suction pen 8 for picking up defective lenses and placing them in the defective lens trays 7.

[0009] The device for lens vision inspection as described above is characterized in that: three industrial cameras 3 and three corresponding light-diffusing masks 4 are provided above the machine base 1, and the light-diffusing masks 4 are respectively located directly below the industrial cameras 3.

[0010] The device for lens vision inspection as described above is characterized in that: a first support 9 is provided on the machine base 1, a first slide rail 10 is provided on the first support 9 and a first adjusting screw 11 for adjusting the accuracy of the industrial camera 3 moving up and down along the first slide rail 10 is provided on the first support 9, and three second slide rails 12, an L-shaped plate 14 that can move up and down along the second slide rails 12, and a second adjusting screw 13 for adjusting the accuracy of the movement of the L-shaped plate 14 are respectively provided on the first support 9, and three light uniform covers 4 are respectively fixed on the three L-shaped plates 14.

[0011] The device for lens vision inspection as described above is characterized in that: an industrial camera 3 and a light-diffusing cover 4 are provided below the machine base 1, the industrial camera 3 below the machine base 1 is arranged opposite to one of the industrial cameras 3 above the machine base 1, and the industrial camera 3 below the machine base 1 and its light-diffusing cover 4 can be adjusted to move up and down along the slide rail.

[0012] The device for lens visual inspection as described above is characterized in that: an opening 101 is provided on the machine base 1, and a second bracket 15 for mounting the industrial camera 3 and a third bracket 16 for mounting the light-diffusing cover 4 are respectively fixed on both sides of the opening 101.

[0013] The device for lens visual inspection as described above is characterized in that: the suction pen 8 is disposed on the first bracket 9.

[0014] The device for lens vision inspection as described above is characterized in that: the driving device 2 includes a linear motor 17 for driving the feeding plate 5 to move along the X-axis, a motor 18 for driving the feeding plate 5 to move along the Y-axis, and a lead screw transmission mechanism 19.

[0015] The device for lens visual inspection as described above is characterized in that: a cylinder 20 is provided on the first bracket 9 to drive the suction pen 8 to move up and down.

[0016] The device for lens vision inspection as described above is characterized in that: a scale 21 for measuring the displacement of the industrial camera 3 is provided next to the first slide rail 10.

[0017] Compared with the prior art, the present invention has the following advantages.

[0018] 1. This utility model enables automated visual inspection without moving the industrial camera, avoiding the impact of camera movement on inspection accuracy and greatly improving inspection efficiency and quality.

[0019] 2. This utility model features a uniform light cover with independent up-and-down adjustment: achieving "cloudy day" non-directional diffuse reflection illumination, eliminating lens reflections and hot spots, and greatly improving the defect recognition rate; the suction pen is integrated into the first bracket: eliminating the need for an additional robotic arm, resulting in a compact structure and significantly reduced costs; the scale and lead screw fine adjustment: positioning accuracy ±0.1 mm, ensuring precise focus for different lens layers; and the integrated material tray: reducing the number of manual interventions and enabling "one person, multiple machines". Attached Figure Description

[0020] Figure 1 This is a perspective view of the utility model.

[0021] Figure 2 This is one of the perspective views of the present invention after some of the components have been hidden.

[0022] Figure 3 This is the second perspective view of the present invention after some components have been hidden.

[0023] In the diagram: 1 is the machine base; 101 is the opening; 2 is the drive device; 3 is the industrial camera; 4 is the light diffuser; 5 is the feeding plate; 6 is the tray for lenses to be inspected; 7 is the tray for defective lenses; 8 is the suction pen; 9 is the first bracket; 10 is the first slide rail; 11 is the first adjusting screw; 12 is the second slide rail; 13 is the second adjusting screw; 14 is the L-shaped plate; 15 is the second bracket; 16 is the third bracket; 17 is the linear motor; 18 is the motor; 19 is the lead screw transmission mechanism; 20 is the cylinder; 21 is the scale. Detailed Implementation

[0024] The technical features of this utility model will be further described in detail below with reference to the accompanying drawings so that those skilled in the art can understand them.

[0025] A device for lens vision inspection, such as Figures 1 to 3 As shown, the machine includes a machine platform 1, on which are placed multiple industrial cameras 3 for visual inspection of lens appearance and a light-diffusing cover 4. The machine platform 1 is also provided with a feeding plate 5, on which are mounted several trays of lenses to be inspected 6 and trays of defective lenses 7. The machine platform 1 is also provided with a driving device 2 for driving the feeding plate 5 to move along the X-axis and Y-axis to inspect the lenses, and a suction pen 8 for picking up defective lenses and placing them in the trays of defective lenses 7.

[0026] The lens can be an automotive lens containing multiple layers of lenses. In this embodiment, the lens contains four layers, thus requiring four industrial cameras 3 for separate inspection. There are two trays 6 for lenses to be inspected and one tray 7 for defective lenses, both placed on a single loading plate 5. Lenses on both trays 6 are inspected together. Qualified lenses remain stationary, while the positions of defective lenses are marked by a computer. After all inspections are completed, the lenses are transferred together to the defective lens tray 7 using a suction pen 8 for unified storage. The entire process requires only manual loading and unloading, significantly improving inspection efficiency. Furthermore, the use of industrial cameras greatly enhances the quality of inspection compared to visual inspection.

[0027] The suction pen 8 is mounted on the first support 9, and a cylinder 20 is provided on the first support 9 to drive the suction pen 8 to move up and down, facilitating the suction of defective lenses. The driving device 2 includes a linear motor 17 that drives the feeding plate 5 to move along the horizontal X-axis, a motor 18 that drives the feeding plate 5 to move along the horizontal Y-axis, and a lead screw transmission mechanism 19. During the inspection process, the industrial camera 3 and the light distribution cover 4 remain stationary, while the lens is driven to move horizontally by the driving device 2. The lead screw transmission mechanism 19 includes a lead screw and a nut mounted on the lead screw.

[0028] Furthermore, three industrial cameras 3 and three corresponding light-diffusing masks 4 are provided above the machine platform 1, with the light-diffusing masks 4 respectively located directly below the industrial cameras 3. The function of the light-diffusing masks 4 is to homogenize the light, converting the light source above into non-directional diffused light, eliminating specular reflections and hot spots on the lens surface; simulating an ideal lighting environment, as if shooting under a "cloudy sky," to avoid false detections caused by changes in the angle of light.

[0029] Specifically, a first support 9 is provided on the machine base 1. A first slide rail 10 and a first adjusting screw 11 are provided on the first support 9 to adjust the vertical movement accuracy of the industrial camera 3 along the first slide rail 10. Three corresponding first slide rails 10 and first adjusting screws 11 are provided. A scale 21 for measuring the displacement of the industrial camera 3 is provided next to the first slide rail 10. By moving the three industrial cameras 3 up and down, their focal lengths are adjusted, allowing them to detect different layers of lenses. The adjusting screws are used for locking; after the industrial camera 3 and the light-diffusing mask 4 are manually slid to the designated position, they are locked in place using the adjusting screws.

[0030] The first bracket 9 is also provided with three second slide rails 12, an L-shaped plate 14 that can move up and down along the second slide rails 12, and a second adjusting screw 13 for adjusting the moving accuracy of the L-shaped plate 14. The three uniform light covers 4 are respectively fixed on the three L-shaped plates 14.

[0031] Two industrial cameras 3 can be arranged opposite each other above and below the machine tool 1. In this embodiment, one industrial camera 3 and one light-diffusing mask 4 are located below the machine tool 1. The industrial camera 3 below the machine tool 1 is arranged opposite to one of the industrial cameras 3 above the machine tool 1. The industrial camera 3 below the machine tool 1 and its light-diffusing mask 4 can be adjusted to move up and down along a slide rail. The industrial camera 3 below the machine tool 1 is used to detect the bottommost lens element.

[0032] Specifically, an opening 101 is provided on the machine base 1, and a second bracket 15 for mounting the industrial camera 3 and a third bracket 16 for mounting the light-diffusing cover 4 are fixed on both sides of the opening 101.

[0033] Compared with existing technologies that involve "stationary lens and moving industrial camera", the solution proposed in this patent application, which involves "fixed industrial camera and lens moving with the feeding plate", has significant advantages in five dimensions: structure, accuracy, cycle time, stability, and cost. These advantages can be summarized as follows: 1. Higher detection accuracy • Existing technology: Camera movement causes inertial vibration, which can easily cause micro-shaking during imaging, resulting in blurred edges, relatively large repositioning errors, and difficulty in detecting minute defects.

[0034] • This patent: The camera is completely fixed, and only the extremely lightweight feeding plate and tray move slowly in the horizontal plane. The moment of inertia is greatly reduced, the imaging platform has zero shaking, and the measured repeatability error is relatively small, which can stably identify more subtle scratches / offsets.

[0035] 2. Faster cycle time and higher production capacity • Existing technology: The camera needs to be moved over each lens in sequence → focus → take a picture → move again, which results in a relatively large average time consumption per unit.

[0036] • This patent: The feeding plate is equipped with multiple lenses at one time, and the XY linear motor scans continuously, so there is no need to wait for the robotic arm to move back and forth to take pictures; combined with the upper and lower opposing cameras to complete the detection at the same time, the single-piece cycle time is ≤1.8 s, and the production capacity is increased by ≥2.5 times.

[0037] 3. More compact structure and lower cost • Existing technology: requires a three-axis gantry / robot to drive the camera, occupies more than 1 m³ of space, and requires a high-rigidity frame to suppress vibration.

[0038] • This patent: The camera is fixed on the bracket, and the only moving part is the lightweight feeding plate, reducing the overall size of the machine to 0.3m³; the expensive three-axis robot is eliminated, and the hardware cost is reduced by about 30%.

[0039] 4. Improved system stability and maintainability • Existing technology: Frequent camera start-stop cycles result in cable bending more than 1 million times per month, leading to a high fatigue breakage rate in the wiring harness; heavy loads on the guide rails and motors increase the failure rate.

[0040] • This patent: The camera and light source are stationary, with no power cable dragging, increasing the mean time between failures (MTBF) by more than 3 times; the moving parts are only low-load linear motors, extending the maintenance cycle from 2 months to 1 year.

[0041] 5. More convenient debugging and replacement • Existing technology: Each time the lens model is changed, the three-axis robot coordinate system needs to be recalibrated, which takes 2–3 hours.

[0042] • This patent: The camera is fixed and equipped with a scale, requiring only fine adjustment of the focal plane in the Z direction; the XY travel can be switched with one click via software parameters, and the changeover time is less than 10 minutes, achieving "one-click changeover".

[0043] In summary, this patent, through the reverse design of "fixed camera and moving tray", not only solves the bottleneck of accuracy and stability caused by camera movement, but also significantly improves detection efficiency and reduces equipment costs, thus constituting a substantial improvement over the prior art.

[0044] The embodiments described herein are merely preferred embodiments of the present invention and are not intended to limit the concept and scope of the invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the design concept of the present invention shall fall within the protection scope of the present invention.

Claims

1. A device for lens visual inspection, characterized in that: The machine includes a machine platform (1), on which are placed multiple industrial cameras (3) for visual inspection of lens appearance and a light-diffusing mask (4). The machine platform (1) is also provided with a feeding plate (5), on which are mounted several lens trays (6) to be inspected and unqualified lens trays (7). The machine platform (1) is also provided with a driving device (2) for driving the feeding plate (5) to move along the X-axis and Y-axis to inspect the lens, and a suction pen (8) for grabbing unqualified lenses and placing them on the unqualified lens tray (7).

2. The device for lens visual inspection according to claim 1, characterized in that: The machine platform (1) is equipped with three industrial cameras (3) and three corresponding light-diffusing masks (4) above it. The light-diffusing masks (4) are respectively located directly below the industrial cameras (3).

3. The device for lens visual inspection according to claim 2, characterized in that: A first support (9) is provided on the machine base (1). A first slide rail (10) and a first adjusting screw (11) for adjusting the up-and-down movement accuracy of the industrial camera (3) along the first slide rail (10) are provided on the first support (9). Three second slide rails (12), an L-shaped plate (14) that can move up and down along the second slide rail (12), and a second adjusting screw (13) for adjusting the movement accuracy of the L-shaped plate (14) are also provided on the first support (9). Three light-diffusing covers (4) are fixed on the three L-shaped plates (14) respectively.

4. The device for lens visual inspection according to claim 2, characterized in that: An industrial camera (3) and a light-diffusing cover (4) are provided below the machine platform (1). The industrial camera (3) below the machine platform (1) is positioned opposite to one of the industrial cameras (3) above the machine platform (1). The industrial camera (3) below the machine platform (1) and its light-diffusing cover (4) can be adjusted to move up and down along the slide rail.

5. The device for lens vision inspection according to claim 4, characterized in that: An opening (101) is provided on the machine base (1), and a second bracket (15) for mounting the industrial camera (3) and a third bracket (16) for mounting the light-diffusing cover (4) are fixed on both sides of the opening (101).

6. The apparatus for lens vision inspection according to claim 3, characterized in that: The suction pen (8) is mounted on the first bracket (9).

7. The device for lens visual inspection according to claim 1, characterized in that: The driving device (2) includes a linear motor (17) that drives the feeding plate (5) to move along the X-axis, a motor (18) that drives the feeding plate (5) to move along the Y-axis, and a lead screw transmission mechanism (19).

8. The apparatus for lens visual inspection according to claim 3, characterized in that: A cylinder (20) is provided on the first bracket (9) to drive the suction pen (8) to move up and down.

9. The apparatus for lens visual inspection according to claim 3, characterized in that: A scale (21) for measuring the displacement of the industrial camera (3) is provided next to the first slide rail (10).

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