Assembling and correcting tool and assembling and correcting method for debugging optical axis

Abstract

The embodiment of the invention discloses an assembly and calibration tool and method for debugging an optical axis, and the assembly and calibration tool is configured in AA machine equipment, and comprises a reference platform, a first installation frame, a second installation frame, and a test pattern plane plate. The assembling and correcting method comprises the steps that the reference platform is horizontally corrected, so that any position of the reference platform is in a horizontal state; respectively calibrating the parallelism between the test chart plane plate and the reference platform and the parallelism between the third mounting position and the reference platform through a collimating laser; determining the position of a main optical axis through a camera on the first mounting position, and adjusting the horizontal position of the third mounting position to enable the center of the third mounting position to coincide with the position of the main optical axis; a dial indicator is fixed on the reference platform, and the dial indicator is used to cooperate with the sensing module to be installed to complete positioning. According to the assembling and calibrating tool and method, a laser collimation mode is matched with camera point location extraction, personal errors can be effectively eliminated, and the precision of the assembling and calibrating process of AA machine table equipment is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of optical axis debugging, and in particular to a calibration tool and a calibration method for debugging an optical axis. Background Art

[0002] With the increasing demand for automotive lenses, the key process equipment in the production process of automotive camera modules, that is, the equipment for processing automotive camera modules - AA (Active Alignment) machines have become the mainstream camera and sensor module coupling assembly equipment in the factory's mass production. The existing AA equipment is mainly composed of automatic loading and unloading, plasma cleaning, lens AA, lens dispensing, glue shape inspection, and ultraviolet light curing. Among them, the six-axis automatic alignment accuracy directly affects the imaging quality of the camera module and is the core part of its process technology. Therefore, the optical axis concentricity and tilt angle debugging of the AA equipment are crucial.

[0003] However, the current AA machines generally use mechanical limiters and laser rangefinders to adjust the concentricity and parallelism of the central optical axis. For optical equipment, the accuracy of debugging is lacking. Summary of the invention

[0004] The main purpose of the present invention is to provide a calibration tool and calibration method for debugging the optical axis, so as to solve the problem that the optical axis debugging accuracy of AA machine equipment cannot meet the requirements in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solution: a calibration tool for debugging an optical axis, the calibration tool comprising:

[0006] A reference platform, wherein the reference platform is assembled in the AA machine equipment;

[0007] A first mounting frame is arranged on the reference platform, wherein the first mounting frame has a first mounting position for mounting an industrial camera, a second mounting position for mounting a beam splitter prism, and a third mounting position for mounting a teleconverter, which are sequentially distributed in the same vertical direction;

[0008] A second mounting frame arranged on the reference platform and a collimating laser mounted on the second mounting frame, the collimating laser being used to emit laser light to a beam splitter prism mounted on the second mounting position and forming a reflection light path through the beam splitter prism; and

[0009] A test pattern plane plate is arranged in parallel above the reference platform, wherein the test pattern plane plate comprises a protective glass and a test pattern and is used for receiving the reflected light of the reflected light path.

[0010] On the other hand, at least one embodiment of the present invention further provides a calibration method for debugging an optical axis, the calibration method is applied to the calibration tool as described above, and the calibration method comprises:

[0011] Correcting the reference platform horizontally so that any position of the reference platform is in a horizontal state;

[0012] Calibrate the parallelism between the test plane plate and the reference platform by using the collimating laser, and calibrate the parallelism between the third mounting position and the reference platform by using the collimating laser;

[0013] According to the position of the main optical axis, the horizontal positions of the test chart plane plate and the third installation position are respectively adjusted so that the corner points of the test chart plane plate and the center of the third installation position coincide with the position of the main optical axis;

[0014] A micrometer is fixed on the reference platform, and the micrometer is used in conjunction with the sensor loading platform to complete positioning.

[0015] For example, in the calibration method provided by at least one embodiment of the present invention, the step of calibrating the parallelism between the test pattern plane plate and the reference platform by the collimated laser comprises:

[0016] Measuring the vertical heights of the light spots of the collimated laser at different positions and the surface of the reference platform, and adjusting the collimated laser so that the laser output direction is inclined at an angle less than 2′ with the surface of the reference platform;

[0017] The laser beam of the collimated laser is reflected onto the test pattern plane plate by the beam splitter prism installed on the second installation position; wherein an aperture hole is installed on a side of the beam splitter prism close to the test pattern plane plate;

[0018] The tilt angle of the test chart plane plate is adjusted so that the reflected light path passes through the aperture hole again after being reflected by the protective glass of the test chart plane plate, thereby completing the parallelism calibration between the test chart plane plate and the reference platform.

[0019] For example, in the calibration method provided by at least one embodiment of the present invention, the step of calibrating the parallelism between the third mounting position and the reference platform by the collimated laser includes:

[0020] Measuring the vertical heights of the light spots of the collimated laser at different positions and the surface of the reference platform, and adjusting the collimated laser so that the laser output direction has an inclination angle of less than 2′ with the surface of the reference platform;

[0021] The laser light of the collimated laser is reflected onto the reflective flat crystal by the beam splitter prism installed on the second mounting position; wherein the beam splitter prism is installed with an aperture hole on a side close to the test pattern plane plate, and the reflective flat crystal is placed on the third mounting position;

[0022] The inclination angle of the third mounting position is adjusted so that the reflected light path passes through the aperture hole again after being reflected by the reflective flat crystal, thereby completing the parallelism calibration between the third mounting position and the reference platform.

[0023] For example, in the calibration method provided by at least one embodiment of the present invention, the horizontal positions of the test chart plane plate and the third mounting position are respectively adjusted according to the position of the main optical axis so that the corner points of the test chart plane plate and the center of the third mounting position coincide with the position of the main optical axis, including:

[0024] Installing an industrial camera at the first installation position;

[0025] The test pattern of the test plane plate is photographed by the industrial camera, and the corner point positions in the test pattern are obtained by a corner point extraction algorithm; wherein the test pattern also includes a light spot formed by the collimated laser, and the position of the light spot is the main optical axis position;

[0026] Adjusting the horizontal position of the test pattern plane so that the corner point position coincides with the light spot position;

[0027] Determining a center position of the third installation position;

[0028] The horizontal position of the third installation position is adjusted so that the light spot of the collimating laser passes through the center position.

[0029] For example, in the calibration method provided by at least one embodiment of the present invention, the horizontal position of the third mounting position is adjusted so that the spot of the collimated laser passes through the center position, and then the method further includes:

[0030] Installing a teleconverter on the third mounting position, and photographing a test image and a light spot formed by a laser with an industrial camera to determine whether the corner point position coincides with the light spot;

[0031] If yes, the concentricity calibration of the teleconverter and the lens is completed.

[0032] For example, in the calibration method provided by at least one embodiment of the present invention, the micrometer is fixed on the reference platform, and the micrometer is used in conjunction with the sensor loading platform to complete the positioning, including:

[0033] Fix the micrometer at the preset position of the reference platform and remove the collimating laser and the beam splitter prism;

[0034] Move the sensor loading platform in a first direction and determine a first positioning position by a micrometer;

[0035] Move the sensor loading platform in a second direction and determine a second positioning position by a micrometer;

[0036] The sensor loading platform is moved in a third direction, and a third positioning position is determined by a micrometer.

[0037] For example, in the calibration method provided by at least one embodiment of the present invention, the spot diameter of the collimated laser is less than 2 mm.

[0038] For example, in the calibration method provided by at least one embodiment of the present invention, the light-transmitting diameter of the aperture is between 1 mm and 2.5 mm.

[0039] For example, in the calibration method provided by at least one embodiment of the present invention, the beam splitter prism is one of a flat beam splitter, a cubic beam splitter, a thin film beam splitter, a polka dot beam splitter or a special prism beam splitter.

[0040] For example, in the calibration method provided by at least one embodiment of the present invention, the camera is an industrial camera with a resolution higher than 2048×2048, and the effective focal length of the lens is between 16 mm and 50 mm.

[0041] Compared with the existing optical axis debugging method or related process, the calibration tool and calibration method for debugging the optical axis of the present invention have at least the following beneficial effects: by using the calibration tool in conjunction with the AA machine equipment, the parallelism of the equipment is first calibrated by laser collimation, wherein the teleconverter can extend the distance of the optical axis, so that the laser light path is in the calibration method of the present application, that is, normal incidence and reflection on a specific object, to ensure high-precision consistency, and achieve high-precision parallelism of the reference platform, teleconverter and test plane plate; on this basis, calibration is performed in conjunction with camera point extraction, and after determining the main optical axis, the horizontal position of the test plane plate and the third mounting bracket is adjusted to achieve pixel-level concentricity deviation control. The calibration method of the present invention avoids the problem of poor accuracy caused by adjusting the optical axis by mechanical limit method and manual operation, and can achieve a higher-precision calibration effect, which is beneficial to the actual use of AA machine equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A structural schematic diagram of an embodiment of a calibration tool for debugging an optical axis provided by the present invention;

[0043] Figure 2 A schematic flow chart of an embodiment of a calibration method for debugging an optical axis provided by the present invention;

[0044] Figure 3 A test pattern photographed by an industrial camera in an embodiment of the present invention;

[0045] Figure 4 A first state diagram of a test chart and a main optical axis during calibration using the calibration tool of the present invention;

[0046] Figure 5 A second state diagram of the test diagram and the main optical axis during the calibration process using the calibration tool of the present invention;

[0047] Explanation of the serial numbers: 10, reference platform; 20, first mounting bracket; 21, first mounting position; 211, industrial camera; 22, second mounting position; 221, beam splitter; 23, third mounting position; 231, teleconverter; 30, second mounting bracket; 31, collimating laser; 40, test pattern plane plate.

[0048] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] The terms "first", "second", "third" in this application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", "third" can expressly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the embodiments of this application, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the steps or units listed, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0051] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0052] Active Alignment technology is an advanced process for achieving high-precision alignment during the assembly of optical modules, also known as the AA process. The AA process technology monitors the position and posture of optical components in real time during assembly, and uses a precise motion control system to make active adjustments to ensure that key components such as lenses and sensors achieve the best relative position and angle, thereby significantly improving the imaging quality and overall performance of the module. This technology is particularly critical for the production of high-end camera modules. The AA process technology can effectively overcome the dimensional deviations and assembly errors in traditional assembly methods, improve product consistency and yield, and is an important innovation in the field of modern optical manufacturing.

[0053] At present, the equipment that applies AA process technology is usually called AA machine. The main functions include automatic loading and unloading, plasma cleaning, lens AA, lens dispensing, glue shape inspection, ultraviolet light curing, etc. Among them, the lens AA part is to align the lens and the sensor. Generally, a six-axis automatic alignment method is used. The accuracy of this alignment method directly affects the imaging quality of the camera module, such as image blur, color distortion, poor product consistency, etc. Therefore, before using the AA machine to actively align the camera lens and the sensor, it is necessary to ensure that the equipment or calibration system itself has high-precision alignment specifications-that is, the concentricity and parallelism of the optical axis and the calibration object. In the existing AA machine, the adjustment of parallelism generally uses a laser rangefinder to measure the distance between the test chart (chart) and the teleconverter mounting table. For example, for measurements within 200 meters, the accuracy of the laser rangefinder is about 2mm. According to this accuracy, according to the inverse tangent function relationship, it can be deduced that this calibration method can ensure that the inclination angle of the teleconverter does not exceed 2.8°, that is:

[0054]

[0055] The parallelism tolerance of the current mainstream teleconverter design generally needs to be controlled within 0.2°, and the optical calibration process cannot meet this requirement, which will cause test deviation. As for concentricity calibration, it mainly relies on mechanical limit adjustment to adjust the optical axis center. The calibration accuracy depends on the machining accuracy of the structural parts, which is relatively low for optical equipment. At the same time, the fixture itself has tolerances, and there are subjective errors in manual operation during rotation, which will also cause deviations in the calculation of the optical axis center, resulting in the calibration accuracy of concentricity not being able to achieve high precision.

[0056] In view of the disadvantages of the current optical active alignment and calibration technology in AA machines, this application proposes a calibration tool and method for debugging the optical axis, so as to significantly improve the calibration accuracy of the lens and sensor.

[0057] One embodiment of the present application provides a calibration tool for debugging an optical axis, see Figure 1 The calibration tooling includes: a reference platform 10, a first mounting frame 20, a second mounting frame 30 and a test plane 40; wherein the reference platform 10 is assembled in the AA machine device; the first mounting frame 20 is arranged on the reference platform 10, and the first mounting frame 20 is in the same vertical direction - for example Figure 1 From bottom to top, there are arranged in sequence a first mounting position 21 for mounting an industrial camera 211, a second mounting position 22 for mounting a beam splitter prism 221, and a third mounting position 23 for mounting a teleconverter 231; a second mounting bracket 30 is arranged on the reference platform 10, and the second mounting bracket 30 is used to mount a collimated laser 31, and the collimated laser 31 is used to emit laser light to the beam splitter prism 221 mounted on the second mounting position 22 and form a reflected light path by the beam splitter prism 221; a test pattern plane plate 40 is arranged in parallel above the reference platform 10, including a protective glass layer and a test pattern layer, and is used to receive reflected light of the reflected light path.

[0058] Specifically, the calibration tool can be installed and fixed in the AA machine equipment in the form of a marble platform as a reference platform 10 to form a calibration system with the tool as a whole. By adjusting and cooperating with the tool, it can maintain a consistent posture with the AA machine equipment, and then adjust the parallelism and concentricity of the calibration system as a whole through the tool to actively align the lens and sensor. Among them, the first mounting frame 20 is configured with mounting positions for installing different calibration elements, such as an industrial camera 211, a dichroic prism 221, and a teleconverter 231. It should be noted that in the above embodiment, the first mounting position 21, the second mounting position 22, and the third mounting position 23 are separable or detachable from the objects they are installed. Although the present application describes the installation object of each mounting position, other necessary elements can also be installed if possible, such as the reflective flat crystal involved in the embodiment of the calibration method, which will be described in detail later. The second mounting bracket 30 is mounted on one side of the first mounting bracket 20. When the collimated laser 31 is installed, the laser light path emitted from it can reach the beam splitter prism 221 and be reflected onto the test pattern plane plate 40, and then be reflected again by the test pattern plane plate 40 (the protective glass layer) to return the light path.

[0059] In order to facilitate understanding of the functions and effects that can be achieved by the structural design of the installation and calibration tooling in this embodiment, it is necessary to use the installation and calibration method and process for specific explanation. Please refer to the embodiments below for details.

[0060] At least one embodiment of the present invention further provides a calibration method for debugging an optical axis, the calibration method is applied to the calibration tooling in the previous embodiment, see Figure 2 , the calibration method includes:

[0061] Step S1, horizontally calibrating the reference platform so that any position of the reference platform is in a horizontal state;

[0062] In the process of installation or calibration, theoretically, it is only necessary to ensure the high-precision consistency between the reference platform (or the entire installation and calibration tool) and the AA machine equipment for subsequent calibration operations. However, considering the actual working state, the reference platform as the base of the installation and calibration tool can be pre-calibrated for horizontality. The purpose of this step is actually to ensure the consistency between the installation and calibration tool and the AA machine equipment. It should be understood that the "horizontal" in the horizontal correction reference platform refers to the level above the AA machine equipment or relative to the AA machine equipment, and whether the AA machine equipment is in a horizontal state is not related to this embodiment.

[0063] Specifically, the horizontal correction can be achieved through a spirit level, that is, using a spirit level - placing the spirit level at the four corners of the reference platform or other positions, coordinating the lifting and lowering of the fixed foot cup, and adjusting it so that the spirit level is in a horizontal state at any position of the reference platform.

[0064] Step S2, calibrating the parallelism between the test plane plate and the reference platform, and between the third mounting position and the reference platform respectively by using a collimated laser;

[0065] Step S2 is to use the calibration tool to calibrate the parallelism of the AA machine equipment. More precisely, the calibration tool is used to calibrate the parallelism between the test plane and the reference platform, and the third mounting position (teleconverter) and the reference platform. This not only ensures that the necessary elements for active alignment of the AA machine equipment are in a high-precision parallel state, but also exists in the calibration process as a necessary condition for subsequent concentricity calibration. Specifically, the parallelism calibration process can be divided into two aspects: the test plane and the reference platform, and the third mounting position and the reference platform, and the calibration of these two aspects does not have to be in a strict order, as long as the calibration purpose can be achieved.

[0066] An optical test chart is an important tool for evaluating and calibrating the performance of optical equipment. It usually includes a series of patterns or marks designed to test specific types of optical properties, such as resolution, color reproduction, contrast, uniformity, etc. For example, the chart in the test chart plane in this application can be a quarter-square black and white block pattern (such as Figure 3 shown).

[0067] Preferably, the spot diameter of the collimated laser is less than 2 mm. A smaller spot diameter will ensure higher precision when the reflected light and the incident light have the same optical path.

[0068] The following steps are included in the parallelism calibration between the test plane and the reference platform:

[0069] Measure the vertical height of the collimated laser spot at different positions with respect to the reference platform surface, and adjust the output direction of the collimated laser so that the inclination angle between the laser output direction and the reference platform surface is less than 2′;

[0070] The laser emission direction of the collimated laser is the fundamental condition to ensure the ultimate high precision of the assembly and calibration tooling and method of the present application. After the collimated laser is assembled, the vertical height of the light spot is measured at different positions in its laser emission direction (relative to the reference platform). The inclination angle can be calculated by the inverse tangent function, and based on this, the output direction of the collimated laser can be adjusted until the inclination angle reaches the required range.

[0071] For example, two positions are taken at a distance of 100mm and 2000mm from the emission port of the collimated laser, and the vertical heights of the two positions to the surface of the reference platform are measured using a height gauge. The position of the light spot is continuously adjusted so that the vertical height difference between the light spot and the surface of the reference platform at the two positions is within 1mm. The trigonometric function relationship can be used to determine that the inclination angle of the laser emission direction and the surface of the reference platform is less than 2′, that is, within 0.034°. Compared with the existing parallelism calibration that can achieve an accuracy of inclination angle within 2.8°, this process establishes the necessary condition for higher-precision calibration - high-precision parallelism between the laser emission direction and the surface of the reference platform.

[0072] The light path of the collimated laser is reflected to the test chart plane plate by the beam splitter prism installed on the second installation position; wherein an aperture hole is installed on the side of the beam splitter prism close to the test chart plane plate;

[0073] Preferably, the beam splitter prism is one of a flat beam splitter, a cubic beam splitter, a film beam splitter, a polka dot beam splitter or a dedicated prism beam splitter.

[0074] Preferably, the aperture diameter is between 1 mm and 2.5 mm, which can match the laser spot for passing through, and the smaller the aperture, the higher the debugging accuracy, wherein a diameter of 1 mm is the optimal size.

[0075] After completing the parallel calibration between the laser emission direction and the reference platform surface, install the beam splitter prism on the second installation position. According to the installation position relationship of the components of the calibration tooling, the beam splitter prism is located directly below the third installation position (teleconverter). Select a suitable beam splitter prism, such as a 90° beam splitter prism, and make the prism surface perpendicular to the emission direction of the collimated laser, so that the light spot output by the collimated laser passes through the prism and is reflected perpendicularly to the reference platform surface toward the test chart plane. In particular, an aperture hole is installed on the side of the beam splitter prism facing the test chart plane to limit the size of the light beam or field of view (imaging range). The aperture hole can further constrain the spot diameter. Similar to the preferred spot diameter of less than 2 mm, high-precision optical path (optical axis) debugging can also be guaranteed.

[0076] After the laser light path is reflected by the beam splitter to the test chart plane, it will be reflected again due to the protective glass layer on the test chart plane. According to the principle of light reflection, when the light path is incident in the normal direction, the direction will be reversed. Assuming that the parallelism between the test chart plane and the exit direction of the laser (the reference platform surface) is within the expected calibration range, the light path reflected from the test chart plane will pass through the aperture again.

[0077] In actual calibration work, the horizontal reference platform is used as the reference system. The test plane may be tilted. In this case, it is necessary to adjust it in the horizontal direction to achieve the above-mentioned expected state. This can be achieved through the following steps:

[0078] Adjust the tilt angle of the test chart plane plate so that the light spot reflected by the protective glass layer of the test chart plane plate passes through the aperture hole again to complete the parallelism calibration between the test chart plane plate and the reference platform.

[0079] In the actual calibration tooling of the AA machine, the distance between the reference platform and the test chart plane is between 900mm and 1200mm. When the light reflection spot passes through the aperture hole on the dichroic prism, the inclination of the reference platform and the test chart plane is less than 2′ through the inverse tangent function relationship. This can be used to determine whether the test chart plane and the reference platform are parallel to the calibration standard.

[0080] In particular, during this parallelism calibration process, the optical axis distance can be extended through a teleconverter to extend the distance in the incident and reflected directions of the laser light path, further improving the calibration accuracy.

[0081] Similarly, in the parallelism calibration between the third installation position and the reference platform, the following steps are included:

[0082] Measure the vertical height of the collimated laser spot at different positions with respect to the reference platform surface, and adjust the output direction of the collimated laser so that the inclination angle between the laser output direction and the reference platform surface is less than 2′;

[0083] The calibration of the parallelism between the laser emission direction of the collimating laser and the surface of the reference platform is the same as in the previous embodiment and will not be repeated here.

[0084] A reflective flat crystal is placed on the third mounting position; specifically, since the third mounting position is used to install the teleconverter, it can be understood that it exists in the form of a frame surrounding the structure. The principle of installing the reflective flat crystal on the third mounting position is the same as the reflection process of the laser on the test chart plane plate. The purpose is to debug the parallelism between the third mounting position and the surface of the reference platform, that is, the parallelism between the teleconverter and the surface of the reference platform.

[0085] Preferably, the surface PV of the reflective flat crystal is better than λ / 10@632.8nm, which can avoid light beam distortion to a large extent.

[0086] The light path of the collimated laser is reflected to the reflective flat crystal by the beam splitter prism installed on the second installation position; wherein an aperture hole is installed on the side of the beam splitter prism close to the test chart plane plate;

[0087] Referring to the actual distance between the teleconverter and the upper surface of the beam splitter prism of 400mm-700mm, when the reflected light spot passes through the aperture hole on the upper surface of the beam splitter prism, the inclination angle between the teleconverter and the reference platform is less than 3′.

[0088] Adjust the inclination angle of the third mounting position so that the light spot after being reflected by the reflection flat crystal passes through the aperture hole again, completing the parallelism calibration between the third mounting position and the reference platform.

[0089] In the aforementioned embodiments, no matter whether it is the parallelism calibration between the test chart plane plate or the third mounting position and the reference platform, the principles and conditions used are the same, that is, a reference object that is highly parallel to the surface of the reference platform is established with the help of laser, and a dichroic prism with an aperture is designed, and the optical path is adjusted by absolute right-angle reflection to make the laser reflect in the normal (or approximate normal) direction on the test chart plane plate and the third mounting position respectively, and the reflected light path or the reflected light spot passes through the aperture again, so as to adjust the inclination angle of the test chart plane plate and the third mounting position with a high-precision vertical relationship, so that they can achieve a more stringent parallelism standard with the reference platform.

[0090] After completing the parallelism calibration between the test image plane plate and the reference platform, and between the third installation position and the reference platform, the concentricity calibration of the test image plane plate and the third installation position is also required. The concentricity calibration is also achieved with the help of the laser as a reference object. Compared with the parallelism calibration, the applied conditions also include a camera. In fact, the prior art also uses an industrial camera to shoot the test image to achieve concentricity calibration. The difference is that the embodiment of the present application is to calibrate the position information extracted by the camera point in the form of a laser reference object, which will achieve a higher level of improvement in calibration accuracy. Therefore, after step S2, it also includes:

[0091] Step S3, adjusting the horizontal positions of the test pattern plane plate and the third installation position respectively according to the position of the main optical axis, so that the corner points of the test pattern plane plate and the center of the third installation position coincide with the position of the main optical axis;

[0092] Specifically, step S3 mainly realizes the concentricity adjustment of the test diagram plane plate and the third installation position, and the adjustment method is to calibrate by using the laser of the collimated laser as a reference. After completing the parallelism calibration step, the optical path of the laser emitted by the laser after being reflected by the dichroic prism and reaching the test diagram plane plate is close to being absolutely perpendicular to the test diagram plane plate, and its optical path or optical axis has a good reference significance for the concentricity calibration of the test diagram plane plate and the third installation position in the calibration tool. The concentricity of the test diagram plane plate and the third installation position can be specifically calibrated by the following process: installing an industrial camera on the first installation position; photographing the test pattern of the test diagram plane plate by the industrial camera, and obtaining the corner point position in the test pattern by the corner point extraction algorithm; wherein the test pattern also includes a light spot formed by the collimated laser, and the position of the light spot is the main optical axis position; adjusting the horizontal position of the test diagram plane plate so that the corner point position coincides with the position of the light spot; determining the center position of the third installation position; adjusting the horizontal position of the third installation position so that the light spot of the collimated laser passes through the center position.

[0093] After the parallelism calibration is completed, the test pattern and the laser spot position need to be photographed with the help of an industrial camera. At this time, the aperture hole installed on the beam splitter prism needs to be removed so that the industrial camera can capture the image of the test pattern.

[0094] like Figure 4 As shown in FIG. 1 , the image captured by the industrial camera for corner point extraction is shown in FIG. 1 , where the center point of the black and white block pattern at the center is the “corner point” position in this embodiment. After the collimated laser emits the laser and is reflected by the beam splitter prism, the test pattern and laser spot position captured by the industrial camera are shown in FIG. Figure 4As shown, it can be seen that the laser spot at this time does not coincide with the corner point position in the test image, so it is necessary to adjust the position of the test image plane in the horizontal direction so that the corner point position in the test image coincides with the laser spot; it can be understood that this process can be controlled and adjusted using the AA machine in conjunction with the corner point extraction algorithm. For example, the AA machine is connected to a computer device, and a plane rectangular coordinate system with pixel-level accuracy is established for the test pattern photographed by the industrial camera through the computer device, and the corner point position coordinates and the laser spot coordinates are read. Then, the computer program is used to control the movement of the test image plane so that the corner point position coordinates coincide with the laser spot coordinates. Unlike the existing mechanical limit method for calibrating concentricity, the establishment of this rectangular coordinate system is based on the picture taken by the industrial camera. When processed by a computer, it can theoretically be magnified several times or dozens of times to achieve pixel-level accuracy. For example, the picture is enlarged so that each pixel is a coordinate point, and the position of the test image plane is adjusted to align the corner point with the laser spot. The deviation can be controlled within 0.1 pixels, that is, the deviation is less than 0.5μm, until it reaches the following. Figure 5 The effect shown is that a significant improvement in accuracy can be achieved compared to the existing concentricity calibration method, thereby completing the calibration of the corner point position of the test plane plate and the laser optical axis.

[0095] After determining the position of the plane plate of the test diagram, that is, determining the position of the main optical axis, it is further necessary to calibrate the concentricity of the third mounting position and the main optical axis. It has been explained in the above embodiments that the third mounting position is applied in the form of a mounting frame of an enclosing structure, such as a square or circular outline. When calibrating the concentricity of the third mounting position and the main optical axis, it is necessary to determine the center of the third mounting position, and use the main optical axis (laser optical path) to align it to achieve the calibration of the concentricity. The third mounting position is a circular frame, and determining its center is to determine the center of the circular outline. For example, a diameter direction x can be determined by a steel ruler first, and the horizontal position of the third mounting position can be adjusted so that the laser spot passes through the midpoint of the diameter. The steel ruler can be moved or rotated, and the adjustment in the x direction can be performed again at a position perpendicular to the x direction. While determining the center of the third mounting position, the concentricity adjustment is also completed.

[0096] It should be noted that the above examples are only examples for explaining how to determine the center of the third mounting position. When faced with third mounting positions of different forms, those skilled in the art can determine the center position and calibrate the concentricity based on the prior art and common knowledge, and this embodiment does not limit this.

[0097] After completing the concentricity calibration between the third mounting position and the main optical axis, theoretically, the concentricity calibration of the teleconverter is also completed. It should be understood that in the technical solution of the present invention, the purpose of the concentricity calibration of the third mounting position is essentially to calibrate the concentricity of the teleconverter. Since the aforementioned embodiment of the present invention is performed under the condition of ignoring the tolerance of the mounting position and the teleconverter, the concentricity between the third mounting position and the main optical axis is regarded as the concentricity between the teleconverter and the main optical axis. In fact, the tolerance of the mounting position and the teleconverter does exist. Therefore, further, after completing the concentricity calibration between the third mounting position and the main optical axis in the above embodiment, a method of verifying the concentricity after actually installing the teleconverter is also provided, that is, after installing the teleconverter, it is judged by observing whether the corner point position of the test pattern coincides with the laser spot.

[0098] Preferably, the resolution of the industrial camera in this embodiment is higher than 2048×2048, and the effective focal length (EFL) of the lens is between 16 mm and 50 mm.

[0099] In the aforementioned steps S1 to S3, the active alignment system calibration of the AA machine equipment is basically completed, but this part mainly involves or affects the camera lens. During the assembly process, it is also necessary to keep the image sensor and the camera lens aligned with good precision for subsequent processes such as dispensing and curing. Therefore, in the above embodiment, after step S3, it also includes:

[0100] Step S4, fixing the micrometer on the reference platform, and using the micrometer in conjunction with the sensor loading platform to complete positioning.

[0101] Specifically, step S4 includes: fixing the micrometer at a preset position of the reference platform, and removing the laser and the dichroic prism; moving the sensor loading platform in a first direction, and determining a first positioning position by means of the micrometer; moving the sensor loading platform in a second direction, and determining a second positioning position by means of the micrometer; moving the sensor loading platform in a third direction, and determining a third positioning position by means of the micrometer.

[0102] In this embodiment, a sensor SUT can be used as a sensor loading platform. The sensor SUT is equipped with a three-axis (X, Y, and Z directions) motor, and in each direction, the motor can lock the position of the SUT in that direction after being powered on. The level of the sensor SUT is adjusted, the collimating laser and the dichroic prism are removed, the micrometer is fixed on the reference platform, the SUT motors X, Y, and Z are all powered off, the SUT is manually moved to the bottom of the micrometer pointer, the motor Z direction is slowly lifted up, the micrometer pointer contacts the platform surface, and then the Z motor is powered on.

[0103] Move the SUT and test the horizontality in the X direction. Power up the Y motor and slowly move the SUT in the X direction to observe the change in the tester pointer scale. Then adjust the X direction level until the pointer moves within the platform surface and the change is within ±2um, then tighten the fixing screw. Then adjust the Y direction level in the same way as the X direction to complete the optical path debugging of the device light.

[0104] In the above embodiment, the X, Y, and Z directions are three directions represented by the horizontal, vertical, and vertical axes in the spatial rectangular coordinate system, which correspond to the actual application environment, that is, the two directions perpendicular to each other on the surface of the reference platform are the X and Y directions, and the direction perpendicular to the surface of the reference platform is the Z direction.

[0105] In the calibration tooling and calibration method for debugging the optical axis of the present invention, the calibration tooling cooperates with the AA machine equipment, and firstly calibrates the parallelism of the equipment by laser collimation, wherein the teleconverter can extend the distance of the optical axis, so that the laser light path is in the calibration method of the present application, that is, normal incidence and reflection on a specific object, to ensure high-precision consistency, and realize high-precision parallelism of the reference platform, the teleconverter and the test chart plane plate; on this basis, the calibration is carried out in conjunction with the camera point extraction, and after determining the main optical axis, the horizontal position of the test chart plane plate and the third mounting frame is adjusted to achieve pixel-level concentricity deviation control, and further, the positioning of the sensor module to be installed in the AA machine equipment is completed by the micrometer and the sensor module to be installed for assembly. The calibration method of the present invention avoids the poor accuracy caused by adjusting the optical axis by mechanical limit method and manual operation, and can achieve a higher-precision calibration effect, which is conducive to the actual use of the AA machine equipment and improves the yield rate of camera lens module assembly.

[0106] The specific implementation methods of the invention are described in detail above, but they are only examples, and the invention is not limited to the specific implementation methods described above. For those skilled in the art, any equivalent modification or substitution of the invention is also within the scope of the invention, therefore, the equalization, modification and improvement made without departing from the spirit and principle of the invention should be included in the scope of the invention.

Claims

1. A calibration tool for debugging an optical axis, characterized in that: The calibration tooling comprises: A reference platform, wherein the reference platform is assembled in the AA machine equipment; A first mounting frame is arranged on the reference platform, wherein the first mounting frame has a first mounting position for mounting an industrial camera, a second mounting position for mounting a beam splitter prism, and a third mounting position for mounting a teleconverter, which are sequentially distributed in the same vertical direction; A second mounting frame arranged on the reference platform and a collimating laser mounted on the second mounting frame, the collimating laser being used to emit laser light to a beam splitter prism mounted on the second mounting position and forming a reflection light path by the beam splitter prism; and A test pattern plane plate is arranged in parallel above the reference platform, wherein the test pattern plane plate comprises a protective glass and a test pattern and is used for receiving the reflected light of the reflected light path.

2. A method for adjusting an optical axis, characterized in that: The calibration method is implemented by the calibration tool as claimed in claim 1, and the calibration method comprises: Correcting the reference platform horizontally so that any position of the reference platform is in a horizontal state; Calibrate the parallelism between the test plane plate and the reference platform by using the collimating laser, and calibrate the parallelism between the third mounting position and the reference platform by using the collimating laser; According to the position of the main optical axis, the horizontal positions of the test chart plane plate and the third installation position are respectively adjusted so that the corner points of the test chart plane plate and the center of the third installation position coincide with the position of the main optical axis; A micrometer is fixed on the reference platform, and the micrometer is used in conjunction with the sensor loading platform to complete positioning.

3. The calibration method according to claim 2, characterized in that: The method of calibrating the parallelism between the test plane plate and the reference platform by the collimated laser comprises: Measuring the vertical heights of the light spots of the collimated laser at different positions and the surface of the reference platform, and adjusting the collimated laser so that the laser output direction is inclined at an angle less than 2′ with the surface of the reference platform; The laser beam of the collimated laser is reflected onto the test pattern plane plate by the beam splitter prism installed on the second installation position; wherein an aperture hole is installed on a side of the beam splitter prism close to the test pattern plane plate; The tilt angle of the test chart plane plate is adjusted so that the reflected light path passes through the aperture hole again after being reflected by the protective glass of the test chart plane plate, thereby completing the parallelism calibration between the test chart plane plate and the reference platform.

4. The calibration method according to claim 2, characterized in that: The step of calibrating the parallelism between the third mounting position and the reference platform by using the collimating laser comprises: Measuring the vertical heights of the light spots of the collimated laser at different positions and the surface of the reference platform, and adjusting the collimated laser so that the laser output direction has an inclination angle of less than 2′ with the surface of the reference platform; The laser light of the collimated laser is reflected onto the reflective flat crystal by the beam splitter prism installed on the second mounting position; wherein the beam splitter prism is installed with an aperture hole on a side close to the test pattern plane plate, and the reflective flat crystal is placed on the third mounting position; The inclination angle of the third mounting position is adjusted so that the reflected light path passes through the aperture hole again after being reflected by the reflective flat crystal, thereby completing the parallelism calibration between the third mounting position and the reference platform.

5. The calibration method according to claim 2, characterized in that: The step of respectively adjusting the horizontal positions of the test pattern plane plate and the third mounting position according to the position of the main optical axis so that the corner points of the test pattern plane plate and the center of the third mounting position coincide with the position of the main optical axis comprises: Installing an industrial camera at the first installation position; The test pattern of the test plane plate is photographed by the industrial camera, and the corner point positions in the test pattern are obtained by a corner point extraction algorithm; wherein the test pattern also includes a light spot formed by the collimated laser, and the position of the light spot is the main optical axis position; Adjusting the horizontal position of the test pattern plane so that the corner point position coincides with the light spot position; Determining a center position of the third installation position; The horizontal position of the third installation position is adjusted so that the light spot of the collimating laser passes through the center position.

6. The calibration method according to claim 5, characterized in that: The step of adjusting the horizontal position of the third installation position so that the spot of the collimated laser passes through the center position further includes: Installing a teleconverter on the third mounting position, and photographing a test image and a light spot formed by a laser with an industrial camera to determine whether the corner point position coincides with the light spot; If yes, the concentricity calibration of the teleconverter and the lens is completed.

7. The calibration method according to claim 2, characterized in that: The method of fixing a micrometer on the reference platform and using the micrometer in conjunction with the sensor loading platform to complete positioning includes: Fix the micrometer at the preset position of the reference platform and remove the collimating laser and the beam splitter prism; Move the sensor loading platform in a first direction and determine a first positioning position by a micrometer; Move the sensor loading platform in a second direction and determine a second positioning position by a micrometer; The sensor loading platform is moved in a third direction, and a third positioning position is determined by a micrometer.

8. The calibration method according to claim 2, characterized in that: The spot diameter of the collimated laser is less than 2 mm.

9. The calibration method according to claim 4, characterized in that: The aperture diameter is between 1 mm and 2.5 mm.

10. The calibration method according to claim 4, characterized in that: The beam splitter prism is one of a flat beam splitter, a cubic beam splitter, a film beam splitter, a polka dot beam splitter or a special prism beam splitter.

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