Apparatus and method for automatically controlling discharge fusion arc radius to produce fiber lens

Abstract

The present application relates to the technical field of optical fiber production, and particularly relates to an automatic control discharge arc radius optical fiber lens production equipment and method, which comprises a camera system and a discharge arc equipment; the discharge arc equipment is used for discharging the polished conical optical fiber; the camera system is used for automatically detecting the size and eccentricity of the conical optical fiber arc. Further comprising a light spot quality analyzer arranged at the optical fiber outlet, which is used for analyzing the light spot quality of the conical optical fiber. The discharge arc equipment comprises a discharge positive electrode and a discharge negative electrode, and the conical optical fiber is placed between the two electrodes. The present application realizes real-time automatic measurement of the profile size of the optical fiber lens based on machine vision, connects the upstream and downstream processes, and thus realizes one-stop full-automatic production process of the optical fiber lens. The problems of low automation level and low production efficiency in the production process of the existing optical fiber lens are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical fiber production, and particularly relates to an equipment and method for producing optical fiber lens by automatically controlling discharge arc radius. BACKGROUND

[0002] The optical fiber lens is an important device widely used in optical communication and semiconductor laser industry, and typical applications are, for example, at the light emitting point outlet of a semiconductor laser chip, using the optical fiber lens can greatly improve the efficiency of laser coupling into the optical fiber.

[0003] In the industry, precise grinding equipment and electrode discharge equipment are generally used to process the end of the optical fiber with a diameter of 125 microns into a specific shape of a wedge or a cone with a circular arc at the tip, for example, as shown in Figure 1 which is the shape of a conical lens optical fiber. The typical production process is as follows:

[0004] 1. The optical fiber is clamped to the grinding equipment, and the grinding equipment grinds the end of the optical fiber into the required shape (such as a wedge, a cone, etc.), such as Figure 1 with a 90-degree included angle A;

[0005] 2. The ground optical fiber is clamped to the discharge arc equipment for the second time, and the discharge equipment melts the sharpest end of the optical fiber lens into a circular arc through multiple electrode discharges, such as Figure 1 with a radius R of 7 microns (at the present stage, the operator usually observes the change of the circular arc on the microscope screen with the naked eye, and controls the number of electrode discharges to make the radius close to 7 microns);

[0006] 3. The optical fiber lens with a circular arc is clamped to the light spot quality analysis equipment for the third time. A 1000nm laser is transmitted through the other end of the optical fiber, and the laser is emitted from the circular arc area of the conical tip after being conducted by the optical fiber. The light spot quality analyzer is used to test the light spot, and the defective products are removed;

[0007] 4. The optical fiber lens with a qualified light spot is clamped to the high-power microscope for the fourth time, and the operator measures the included angle A of each face of the lens, the size of the circular arc R, and the eccentricity of the circular arc, etc. using the line drawing software, and the defective products outside the tolerance range are removed.

[0008] 5. Pack the qualified products

[0009] As can be seen from the above process, the optical fiber is transferred between multiple stations and clamped multiple times in the entire process, which can easily cause damage to the fragile optical fiber lens invisible to the naked eye, increasing the defective rate.

[0010] Moreover, since the size measurement process is usually in the fourth step, if the shape size measured in the fourth step is problematic, all the previous working steps are wasted time.

[0011] Therefore, the production process of the existing optical fiber lens is low in automation level and low in production efficiency. An automatic production device and method capable of reducing the clamping times and monitoring the size in real time (stopping the subsequent processing of defective products) in the production process is urgently needed. SUMMARY

[0012] Based on the technical problems existing in the background art, the present application provides an automatic control discharge arc radius production optical fiber lens device and method, which realizes real-time automatic measurement of the profile size of the optical fiber lens based on machine vision, connects the upstream and downstream processes, and thus realizes one-stop full-automatic production process of the optical fiber lens. The problems of low automation level and low production efficiency in the production process of the existing optical fiber lens are solved.

[0013] The present application provides the following technical scheme: an automatic control discharge arc radius production optical fiber lens device, comprising a camera system and a discharge arc device;

[0014] The discharge arc device is used for discharging the polished conical optical fiber; and the camera system is used for automatically detecting the size and eccentricity of the conical optical fiber arc.

[0015] Preferably, it further comprises a light spot quality analyzer arranged at the optical fiber outlet, which is used for analyzing the light spot quality of the conical optical fiber.

[0016] Preferably, the discharge arc device comprises a discharge positive electrode and a discharge negative electrode, and the conical optical fiber is placed between the two electrodes.

[0017] Preferably, the conical optical fiber is installed on a rotating shaft, and the rotating shaft is used to drive the conical optical fiber to rotate.

[0018] Preferably, the rotating shaft is installed on a Y-axis and an X-axis, which are used to adjust the displacement of the conical optical fiber in the X direction and the Y direction.

[0019] Preferably, it further comprises a grinding disc and a grinding motor, and the grinding motor is used to drive the grinding disc to rotate and polish the conical optical fiber.

[0020] The X-axis and the Y-axis are used for transferring the conical optical fiber between the polishing station and the detection station.

[0021] An automatic control discharge arc radius production optical fiber lens method, comprising the following steps:

[0022] S1, grinding the optical fiber head to a specified conical shape, and moving the optical fiber clamp to the electrode discharge position;

[0023] S2, the side camera automatically identifies the conical angle through machine vision; in the case of qualified angle, the electrode discharge is started to fuse the arc;

[0024] After each discharge, the side camera automatically measures the radius of the arc, while the spot quality analyzer at the fiber optic outlet analyzes the quality of the spot.

[0025] S3. Repeated discharges are performed until the external dimensions and light spot meet the standards, resulting in a qualified product.

[0026] Preferably, in step S2, the side camera simultaneously and automatically measures the eccentricity of the arc center relative to the optical fiber central axis.

[0027] Preferably, the process of the camera automatically detecting the size and eccentricity of the arc in real time in step S2 is as follows:

[0028] S21. Take a picture of the fiber optic head with a side camera, and use visual software to find the boundary outline of the cone and its position in the picture;

[0029] S22. The obtained conical boundary contour line is segmented, and the boundary points in the segmented area are divided into different arrays, namely, the arc area a, the conical edge area b and c, and the straight edge area d and e.

[0030] S23. Perform arc fitting on the boundary points of the arc region a. This function can simultaneously obtain the arc radius value and the arc center coordinate information.

[0031] S24. Perform line fitting on the cone boundary points in the cone-shaped edge regions b and c. The angle between the two lines is the cone angle.

[0032] S25. Traverse the boundary points in the straight line edge regions d and e, keep only the outermost boundary points, and then perform straight line fitting;

[0033] S26. Generate the corresponding centerline based on the two straight lines in step S25, i.e. the central axis of the optical fiber. Calculate the perpendicular distance from the center coordinates of the arc obtained in step S23 to the centerline, i.e., the eccentricity of the arc on the optical fiber.

[0034] Preferably, the side camera measures the arc radius, arc center coordinates, cone angle, and arc eccentricity on the optical fiber at intervals.

[0035] This invention provides an equipment and method for automatically controlling the arc melting radius in the production of fiber optic lenses. The entire production process requires only one machine at a single workstation; a single clamping and start-up completes the fully automated process. This significantly reduces the complexity of the fiber optic lens production process, minimizes material losses caused by cumbersome manual operations and logistics transfers, and greatly improves the automation level and yield rate of fiber optic lens production. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the present invention;

[0037] Figure 2 This is a schematic diagram of the image segmentation process in machine vision according to the present invention.

[0038] In the diagram: 1. Tapered optical fiber; 2. Camera system; 3. Spot quality analyzer; 4. Discharge positive electrode; 5. Discharge negative electrode; 6. Rotation axis; 7. Y-axis; 8. X-axis; 9. Grinding disc; 10. Grinding motor. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] like Figure 1 As shown, the present invention provides a technical solution: an equipment for automatically controlling the arc melting radius to produce fiber optic lenses, comprising a camera system 2 and an arc melting device;

[0041] The discharge arc melting device is used to discharge the polished tapered optical fiber 1; the discharge arc melting device includes a discharge positive electrode 4 and a discharge negative electrode 5, and the tapered optical fiber 1 is disposed between the two for discharging the tapered optical fiber 1; the camera system 2 is used to automatically detect the size and eccentricity of the arc of the tapered optical fiber 1.

[0042] The equipment also includes a spot quality analyzer 3 located at the fiber optic outlet, used to simultaneously analyze the spot quality of the tapered fiber 1. After each discharge, the side camera automatically measures the radius of the arc (and the eccentricity of the arc center relative to the fiber's central axis), while the spot quality analyzer 3 at the fiber optic outlet also analyzes the spot quality.

[0043] The equipment also includes a grinding disc 9 and a grinding motor 10, wherein the grinding motor 10 is used to drive the grinding disc 9 to rotate and grind the tapered optical fiber 1;

[0044] A tapered optical fiber 1 is mounted on a rotating shaft 6, which is also mounted on the Y-axis 7 and X-axis 8. This rotating shaft is used to adjust the displacement of the tapered optical fiber 1 in the X and Y directions. The X-axis 8 and Y-axis 7 are used for transporting the tapered optical fiber 1 between the grinding station and the inspection station. The rotating shaft 6 drives the tapered optical fiber 1 to rotate, and can also work in conjunction with the X-axis 8 and Y-axis 7 to rotate the tapered optical fiber 1 to different positions on the grinding disc 9 for grinding.

[0045] A method for automatically controlling the arc melting radius in the production of fiber optic lenses includes the following steps:

[0046] S1. After the optical fiber is clamped, the optical fiber head is ground into the specified tapered shape at the grinding position; the optical fiber clamp moves the optical fiber to the electrode discharge position with the optical fiber.

[0047] S2, the 12-megapixel camera on the side automatically recognizes the conical angle through machine vision;

[0048] If the included angle is within acceptable limits, start the electrode discharge to melt the arc. Generally, it takes more than 5-6 discharges to achieve the required 7-micron arc radius at the tip of the cone.

[0049] After each discharge, the side camera automatically measures the radius of the arc (and the eccentricity of the arc center relative to the optical fiber central axis), while the spot quality analyzer at the optical fiber exit also analyzes the spot quality.

[0050] S3. Perform multiple discharges until the dimensions and spot size meet the standards. (If the dimensions are out of tolerance, move the machine back to the grinding position for rework.)

[0051] In this automated production process, the most critical aspect is the need for a camera to automatically detect the dimensions and eccentricity of the arc in real time; otherwise, full automation cannot be achieved. Therefore, the most important technology lies in the camera's automatic measurement method, such as... Figure 2 As shown, the specific implementation process of step S2 is as follows:

[0052] 1. The 12-megapixel camera on the side takes a picture of the fiber optic head. The software uses the findContours function of the OpenCV vision software library to find the boundary contour of the cone and its position in the image.

[0053] 2. Process the obtained conical boundary contour line as follows: Figure 2 The segmentation process shown divides the boundary points within the segmented region into different arrays;

[0054] 3. The leftmost region 'a' is a circular arc region. The taubinSVD function is used to fit the boundary points of this region to a circular arc. This function can simultaneously obtain the radius value of the circular arc and the coordinates of the center of the circular arc.

[0055] 4. Use the fitLine function to... Figure 2 Line fitting is performed on the conical boundary points in regions b and c, and the angle between the two lines is the angle of the cone.

[0056] 5. Traversal Figure 2 For the boundary points in regions d and e, only the outermost boundary points are retained (i.e., interference points are removed), and then a straight line is fitted.

[0057] 6. Generate the corresponding centerline based on the two straight lines in step 5, i.e. the central axis of the optical fiber. Calculate the perpendicular distance from the center coordinates of the arc obtained in step 3 to the centerline, thus obtaining the eccentricity of the arc on the optical fiber.

[0058] 7. At this point, the machine vision has obtained key dimensional information such as the radius of the arc, the eccentricity of the arc center, and the included angle of the cone;

[0059] 8. The camera measures the above dimensions approximately every 300 milliseconds.

[0060] With automated measurement using machine vision, every step in the production of fiber optic lenses is monitored in real time, preventing the subsequent processing of defective products and greatly improving production efficiency.

[0061] In the current fiber optic lens manufacturing process, the spatial independence of each process leads to a high defect rate and low production efficiency due to problems such as multiple clamping operations and the inability to perform real-time dimensional control during production.

[0062] In this invention, the entire production process of optical fiber lenses can be fully automated by using only one device at a single workstation, with a single clamping and a click to start. This significantly reduces the complexity of the optical fiber lens production process, minimizes material losses caused by cumbersome manual operations and logistics transfers, and greatly improves the automation level and yield rate of optical fiber lens production.

[0063] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for automatically controlling the arc melting radius to produce fiber optic lenses, implemented based on an equipment for automatically controlling the arc melting radius to produce fiber optic lenses, the equipment for automatically controlling the arc melting radius to produce fiber optic lenses including a camera system (2) and an arc melting device; The discharge arc melting device is used to discharge the polished tapered optical fiber (1); the camera system (2) is used to automatically detect the size and eccentricity of the arc of the tapered optical fiber (1). It also includes a spot quality analyzer (3) installed at the fiber optic outlet, used to analyze the spot quality of the tapered fiber (1). The arc melting device includes a positive discharge electrode (4) and a negative discharge electrode (5), with the tapered optical fiber (1) disposed between them. It also includes a grinding disc (9) and a grinding motor (10), the grinding motor (10) being used to drive the grinding disc (9) to rotate and grind the tapered optical fiber (1). Its features are: Includes the following steps: S1. Grind the fiber optic head into the specified tapered shape, and move the fiber optic clamp with the fiber optic to the electrode discharge position. S2. The side camera automatically identifies the conical angle using machine vision; if the angle is within acceptable limits, it initiates electrode discharge to melt the arc. After each discharge, the side camera automatically measures the radius of the arc, while the spot quality analyzer at the fiber optic outlet analyzes the quality of the spot. In step S2, the side camera simultaneously and automatically measures the eccentricity of the arc center relative to the optical fiber central axis. The process of the camera automatically detecting the size and eccentricity of the arc in real time in step S2 is as follows: S21. Take a picture of the fiber optic head with a side camera, and use visual software to find the boundary outline of the cone and its position in the picture; S22. The obtained conical boundary contour line is segmented, and the boundary points in the segmented area are divided into different arrays, namely, the arc area a, the conical edge area b and c, and the straight edge area d and e. S23. Perform arc fitting on the boundary points of the arc region a, and obtain the arc radius value and the arc center coordinate information at the same time; S24. Perform line fitting on the cone boundary points in the cone-shaped edge regions b and c. The angle between the two lines is the cone angle. S25. Traverse the boundary points in the straight line edge regions d and e, keep only the outermost boundary points, and then perform straight line fitting; S26. Generate the corresponding centerline based on the two straight lines in step S25, i.e. the central axis of the optical fiber. Calculate the perpendicular distance from the center coordinate of the arc obtained in step S23 to the centerline, i.e., the eccentricity of the arc on the optical fiber. S3. Repeated discharges are performed until the external dimensions and light spot meet the standards, resulting in a qualified product.

2. The method for automatically controlling the arc melting radius to produce fiber optic lenses according to claim 1, characterized in that: The side camera measures the radius of the arc, the coordinates of the arc center, the included angle of the cone, and the eccentricity of the arc on the optical fiber at intervals.

3. The method for automatically controlling the arc melting radius to produce fiber optic lenses according to claim 1, characterized in that: The tapered optical fiber (1) is mounted on a rotating shaft (6), which is used to drive the tapered optical fiber (1) to rotate.

4. The method for automatically controlling the arc melting radius to produce fiber optic lenses according to claim 3, characterized in that: The rotating shaft (6) is mounted on the Y-axis (7) and X-axis (8) for adjusting the displacement of the tapered optical fiber (1) in the X and Y directions.

5. The method for automatically controlling the arc melting radius to produce fiber optic lenses according to claim 4, characterized in that: The X-axis (8) and Y-axis (7) are used for the transfer of the tapered optical fiber (1) between the grinding station and the inspection station.

Images