Methods, devices and systems for detecting lens eccentricity

Abstract

This invention discloses a method, apparatus, and system for detecting lens eccentricity. The method includes: acquiring an actual projected image formed by multiple preset light beams passing through a lens to be tested and reaching the focal plane of an image sensor; determining the optical center coordinates of the lens to be tested based on the actual projected image and a reference projected image; wherein the reference projected image is a projected image formed by the multiple preset light beams reaching the focal plane of the image sensor without beam deflection; acquiring the geometric center coordinates of the lens to be tested; and determining the eccentricity value of the lens to be tested based on the optical center coordinates and the geometric center coordinates.

Description

Technical Field

[0001] This invention relates to the field of lens technology, and more specifically, to a method, apparatus, and system for detecting lens eccentricity. Background Technology

[0002] Prescription lenses (Rx lenses) are custom-made lenses based on a doctor's prescription, used to correct vision problems such as myopia, hyperopia, and astigmatism. Measuring the deviation between the lens's optical center and geometric center is a crucial quality control step during manufacturing and fitting to ensure the lenses provide optimal vision correction.

[0003] Currently, commonly used methods for measuring eccentricity are all approximate. For example, visual inspection involves the inspector visually checking the alignment of the lens with the frame to determine if the optical center of the lens is aligned with the center of the pupil. These methods all rely on the inspector's professional experience and have low accuracy in eccentricity measurement. Summary of the Invention

[0004] One objective of this invention is to provide a new technical solution for detecting lens eccentricity.

[0005] According to a first aspect of the present invention, a method for detecting the eccentricity of a lens is provided, comprising:

[0006] Acquire the actual projected image formed by multiple preset light beams passing through the lens to be detected and reaching the focal plane of the image sensor;

[0007] The optical center coordinates of the lens to be tested are determined based on the actual projected image and the reference projected image; wherein, the reference projected image is the projected image formed by the plurality of preset beams reaching the focal plane of the image sensor without beam deflection;

[0008] Obtain the geometric center coordinates of the lens to be tested;

[0009] The eccentricity value of the lens to be tested is determined based on the optical center position coordinates and the geometric center position coordinates.

[0010] Optionally, the reference projection image includes a reference projection point corresponding to each of the plurality of preset beams, and the actual projection image includes an actual projection point corresponding to each of the plurality of preset beams. Determining the optical center coordinates of the lens to be tested based on the actual projection image and the reference projection image includes:

[0011] Based on the position coordinates of the actual projection point of each of the plurality of preset beams in the actual projection image and the position coordinates of the reference projection point in the reference projection image, determine the position offset value corresponding to each of the plurality of preset beams;

[0012] The optical center coordinates of the lens to be tested are determined based on the position offset value corresponding to each of the plurality of preset beams.

[0013] Optionally, determining the optical center coordinates of the lens to be tested based on the position offset value corresponding to each of the plurality of preset beams includes:

[0014] The effective optical thickness and beam deflection angle of each of the plurality of preset beams are obtained; wherein, the effective optical thickness is the optical path length of the beam in the lens to be tested;

[0015] Based on the position offset value corresponding to each of the plurality of preset beams, the effective optical thickness, and the beam deflection angle, the prism power corresponding to each of the plurality of preset beams is determined;

[0016] The optical center coordinates of the lens to be tested are determined based on the prism power corresponding to each of the plurality of preset beams.

[0017] Optionally, acquiring the actual projected image formed by multiple preset light beams passing through the lens to be detected and reaching the focal plane of the image sensor includes:

[0018] When the lens to be tested is parallel to the image sensor, an actual projected image is obtained by multiple preset light beams passing through the lens to be tested and reaching the focal plane of the image sensor.

[0019] Optionally, the optical center position coordinates are the position coordinates of the optical center in the first pixel coordinate system, and the geometric center position coordinates are the position coordinates of the geometric center in the second pixel coordinate system. Determining the eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates includes:

[0020] Acquire visual images of the lens to be tested captured by a vision camera;

[0021] Based on the visual image and the actual projected image, determine the coordinate transformation relationship between the first pixel coordinate system and the second pixel coordinate system;

[0022] According to the coordinate transformation relationship, the position coordinates of the optical center in the first pixel coordinate system and the position coordinates of the geometric center in the second pixel coordinate system are transformed into position coordinates in the same pixel coordinate system to obtain the transformed optical center position coordinates and the transformed geometric center position coordinates.

[0023] The eccentricity value of the lens to be tested is determined based on the converted optical center position coordinates and the converted geometric center position coordinates.

[0024] Optionally, determining the eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates includes:

[0025] The measured eccentricity value of the lens to be tested is determined based on the optical center position coordinates and the geometric center position coordinates.

[0026] If the measured eccentricity value is less than or equal to the eccentricity threshold, the measured eccentricity value shall be taken as the eccentricity value of the lens to be tested.

[0027] Optionally, the step of determining the eccentricity threshold includes:

[0028] Obtain the eccentricity value corresponding to each of the multiple standard lenses; wherein, the eccentricity value of each standard lens is determined based on the optical center position coordinates and the geometric center position coordinates of the standard lens;

[0029] The eccentricity threshold is determined based on the multiple eccentricity values ​​corresponding to the multiple standard lenses.

[0030] Optionally, the method further includes:

[0031] If the measured eccentricity value is greater than the eccentricity threshold, the eccentricity error value is determined based on the measured eccentricity value and the eccentricity threshold.

[0032] If the eccentricity error value is within the preset tolerance range and the number of times the eccentricity error value appears in historical eccentricity tests is greater than or equal to the number threshold, the eccentricity threshold is corrected according to the eccentricity error value to obtain the corrected eccentricity threshold.

[0033] If the measured eccentricity value is less than or equal to the corrected eccentricity threshold, the measured eccentricity value shall be used as the eccentricity value of the lens to be tested.

[0034] According to a second aspect of the present invention, an unmanned aerial vehicle (UAV) control device is also provided, comprising a memory and a processor, the memory being used to store executable instructions; the processor being used to operate according to the control of the instructions to perform the method as described in the first aspect of the present invention.

[0035] According to a third aspect of the present invention, a lens eccentricity detection system is also provided, comprising a light source, an image sensor, and a lens eccentricity detection device as described in the second aspect, wherein the light source is used to emit a plurality of preset light beams, the image sensor is used to acquire actual projected images formed by the plurality of preset light beams through the lens to be tested on its focal plane, and to send them to the lens eccentricity detection device.

[0036] One beneficial effect of this invention is that by acquiring the actual projected image formed by multiple preset light beams passing through the lens under test and reaching the focal plane of the image sensor, and determining the optical center coordinates of the lens under test based on the actual projected image and a reference projected image, the accuracy of determining the optical center can be improved compared to the approximate measurement method of existing related technologies. Furthermore, by acquiring the geometric center coordinates of the lens under test, and determining the eccentricity value of the lens under test based on the optical center coordinates and the geometric center coordinates, the accuracy of lens eccentricity detection can be improved. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0038] Figure 1 This is a schematic diagram of the hardware structure of a lens eccentricity detection system according to an embodiment of the present invention;

[0039] Figure 2 This is a schematic flowchart of a lens eccentricity detection method according to an embodiment of the present invention;

[0040] Figure 3(a) is a schematic diagram of a reference projection image according to an example of the present invention;

[0041] Figure 3(b) is a schematic diagram of an actual projected image according to an example of the present invention;

[0042] Figure 3(c) is a schematic diagram of the deflection of an actual projected image and a reference projected image according to an example of the present invention;

[0043] Figure 4 This is a schematic diagram of the structure of a lens eccentricity detection system according to an example of the present invention;

[0044] Figure 5 This is a schematic diagram of the structure of a lens eccentricity detection device according to an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of a lens eccentricity detection system according to an embodiment of the present invention. Detailed Implementation

[0046] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0047] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0048] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0049] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0051] <Hardware Configuration>

[0052] Figure 1 This is a block diagram of the hardware configuration of a lens eccentricity detection system 100 according to an embodiment of the present invention.

[0053] like Figure 1 As shown, the lens eccentricity detection system 100 includes a light source 1000, an image sensor 2000, and a lens eccentricity detection device 3000.

[0054] The light source 1000 can be used to emit multiple preset beams.

[0055] The light source 1000 can be an array of beams or a single beam. When the light source 1000 is a single beam, multiple preset beams can be achieved by emitting beams from different preset positions.

[0056] These multiple preset beams can be parallel or non-parallel; there is no limitation here.

[0057] Image sensor 2000 is used to acquire the actual projected image formed on the focal plane of the lens under test by multiple preset beams, and send it to the lens eccentricity detection device 3000.

[0058] The image sensor 2000 can be a charge-coupled device (CCD) sensor, a complementary metal-oxide-semiconductor (CMOS) sensor, etc., and is not limited here.

[0059] The lens to be tested can be an eyeglass lens, such as myopia, hyperopia, presbyopia lenses, and progressive multifocal lenses, or it can be a camera lens, telescope lens, microscope lens, projector lens, etc.

[0060] Those skilled in the art should understand that the specific type of lens to be tested is not limited herein. That is to say, the lens eccentricity detection method of the embodiments of this application can be applied to prescription lenses or other lenses, and is not limited herein.

[0061] The lens eccentricity detection device can be an electronic device, such as a computer or mobile phone, or other devices, which are not limited here.

[0062] The lens eccentricity detection device is used to determine the optical center position coordinates of the lens to be tested based on the actual projected image and the reference projected image, and then determine the eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates.

[0063] In this embodiment, refer to Figure 1 As shown, the lens eccentricity detection device 3000 may include a processor 3100, a memory 3200, an interface device 3300, a communication device 3400, a display device 3500, an input device 3600, a speaker 300, a microphone 3800, etc.

[0064] Processor 3100 may be a mobile processor. Memory 3200 includes, for example, ROM (Read-Only Memory), RAM (Random Access Memory), and non-volatile memory such as a hard disk. Interface device 3300 includes, for example, a USB interface and a headphone jack. Communication device 3400 is capable of wired or wireless communication. Communication device 3400 may include short-range communication devices, such as any device that performs short-range wireless communication based on short-range wireless communication protocols such as Hilink, WiFi (IEEE 802.11), Mesh, Bluetooth, ZigBee, Thread, Z-Wave, NFC, UWB, and LiFi. Communication device 3400 may also include long-range communication devices, such as any device that performs WLAN, GPRS, or 2G / 3G / 4G / 5G long-range communication. Display device 3500 is, for example, an LCD screen or a touch screen. Display device 3500 is used to display the actual projected image or the eccentricity value of the lens under test. Input device 3600 may include, for example, a touch screen or a keyboard. Users can input / output voice information through speaker 3700 and microphone 3800.

[0065] In this embodiment, the memory 3200 of the lens eccentricity detection device 3000 is used to store instructions for controlling the processor 3100 to operate to at least execute the lens eccentricity detection method according to any embodiment of the present invention. Those skilled in the art can design the instructions according to the disclosed scheme of the present invention. How the instructions control the processor to operate is well known in the art and will not be described in detail here.

[0066] Despite Figure 1 The invention illustrates multiple devices of the lens eccentricity detection device 3000; however, the invention may refer to only some of these devices. For example, the lens eccentricity detection device 3000 may refer only to the memory 3200, the processor 3100, and the display device 3500.

[0067] In this embodiment, the lens eccentricity detection device implements the method according to any embodiment of the present invention based on the actual projected image to determine the eccentricity value of the lens to be tested.

[0068] <Method Implementation>

[0069] Figure 2 This is a schematic flowchart of a lens eccentricity detection method according to an embodiment of the present invention, which can be implemented by a lens eccentricity detection device 3000.

[0070] according to Figure 2 As shown, the lens eccentricity detection method of this embodiment may include the following steps S2100 to S2400:

[0071] Step S2100: Obtain the actual projected image formed by multiple preset beams passing through the lens to be tested and reaching the focal plane of the image sensor.

[0072] In this embodiment, multiple preset beams can be emitted from an array beam, or from an optical fiber bundle, grating, beam splitter, microlens array, LED matrix, laser diode array, etc., or they can be formed by a single unit beam emitted from different emission positions.

[0073] Those skilled in the art should understand that the method of generating multiple preset beams is not limited here.

[0074] Multiple preset beams can be parallel or non-parallel; there is no limitation here.

[0075] Image sensors can be charge-coupled device (CCD) sensors, complementary metal-oxide-semiconductor (CMOS) sensors, etc., and are not limited here.

[0076] The lens to be tested can be an eyeglass lens, such as prescription lenses for nearsightedness or farsightedness, or other lenses such as camera lenses; there are no restrictions here.

[0077] When performing eccentricity detection on the lens to be tested, the lens to be tested is located between the light source emitting the multiple preset beams and the image sensor. The multiple preset beams pass through the lens to be tested and form an actual projected image on the focal plane of the image sensor.

[0078] For example, such as Figure 4 The diagram shows a schematic of a lens eccentricity detection system, which includes a light source 1 and an image sensor 2. The light source 1 is a planar beam array, emitting multiple pre-set parallel beams. During eccentricity detection of the lens 3 under test, the lens 3 is positioned between the light source 1 and the image sensor 2, so that the multiple pre-set beams pass through the lens 3 and form an actual projected image on the image sensor 2.

[0079] If the lens under test is not parallel to the focal plane of the image sensor, on the one hand, the multiple preset beams may focus at different positions on the focal plane, resulting in a blurred or distorted actual projected image; on the other hand, the multiple preset beams will undergo unnecessary refraction when passing through the lens under test, thus producing distortion on the focal plane of the image sensor. These distortions and aberrations in the actual projected image caused by the non-parallelism between the lens under test and the focal plane of the image sensor will further lead to a deviation in the optical center determined based on the actual projected image, resulting in inaccurate off-center detection results. Therefore, to avoid affecting the accuracy of optical center measurement due to the non-parallelism between the lens under test and the focal plane of the image sensor, the lens under test and the focal plane of the image sensor should be adjusted to be parallel before acquiring the actual projected image.

[0080] Based on this, in some embodiments, step S2100, acquiring the actual projected image formed by multiple preset light beams passing through the lens to be detected and reaching the focal plane of the image sensor, includes:

[0081] When the lens to be tested is parallel to the image sensor, an actual projected image is obtained by multiple preset light beams passing through the lens to be tested and reaching the focal plane of the image sensor.

[0082] In this embodiment, the actual projected image is acquired when the lens to be tested is parallel to the focal plane of the image sensor.

[0083] For example, such as Figure 4 As shown, the focal plane of the image sensor is placed horizontally. In order to make the lens to be tested parallel to the image sensor, it is only necessary to place the lens to be tested horizontally.

[0084] In one example, the lens to be tested can be a spherical lens. In this case, a spherical molding fixture can be built based on the bearing surface of the spherical lens. After the spherical lens is placed into the spherical molding fixture, the top, bottom, left and right sides of the spherical lens are pressed with spring clips to make the spherical lens horizontal.

[0085] In this example, the support surface can be the edge where the spherical lens contacts the frame. Using this support surface as a reference, a spherical conforming fixture is created that matches the shape and curvature of the spherical lens. Placing the spherical lens into the conforming fixture ensures that the curvature of the lens matches that of the fixture. After placing the spherical lens into the fixture, spring clips are used to press the lens firmly in all directions, ensuring uniform contact between the lens and the fixture, thus placing the lens horizontally.

[0086] In another example, if the lens to be tested does not have a clear or stable positioning reference, the lens to be tested can be placed on a 5-axis platform, and then the reflection eccentricity of the lens to be tested can be adjusted to 0 by adjusting the 5-axis platform, so that the lens to be tested is placed horizontally.

[0087] In this example, the 5-axis platform can be an adjustment platform with five degrees of freedom, allowing for precise adjustment of the position and orientation of the lens under test placed on it in space. These five degrees of freedom include three translations (up / down, left / right, forward / backward) and two rotations (rotation and tilt). By placing a light source or reflector on the convex surface (outward-facing side) of the lens under test, the position of the reflected light can be observed, allowing the calculation of the deviation between the reflected light and the expected path, thus obtaining the reflection eccentricity. If the lens under test is placed horizontally, the reflected light will be reflected directly back to the direction of the light source; if the lens under test is not placed horizontally, the reflected light will deviate from its original direction. By adjusting the lens under test on the 5-axis platform until the reflected light completely returns to the position of the light source, i.e., the reflection eccentricity is 0, this indicates that the lens under test is placed horizontally.

[0088] According to the embodiments of this application, by acquiring the actual projected image formed by multiple preset beams passing through the lens to be tested and reaching the focal plane of the image sensor when the lens to be tested is parallel to the focal plane of the image sensor, a clear actual projected image can be obtained, thereby improving the accuracy of determining the optical center based on the actual projected image.

[0089] Step S2200: Determine the optical center coordinates of the lens to be tested based on the actual projected image and the reference projected image.

[0090] In this embodiment, since the light beam passing through the optical center of the lens under test does not deflect, the coordinates of the optical center of the lens under test can be determined based on the actual projected image and the reference projected image. The reference projected image is the projection image formed by the multiple preset light beams reaching the focal plane of the image sensor without beam deflection.

[0091] The optical center of the lens to be tested can be determined by means of feature point matching, image registration, machine learning, beam analysis, etc., based on the reference projection image and the actual projection image. No specific method is specified here.

[0092] Determining the optical center by feature point matching can be achieved, for example, by identifying corresponding feature points, such as the center or edge features of the light spot, in the reference projection image and the actual projection image, and then determining the offset of the optical center by matching these feature points.

[0093] Determining the optical center through image registration can be achieved, for example, by aligning a reference projection image and the actual projection image using image registration techniques, and then determining the position of the optical center by comparing transformation parameters.

[0094] Determining the optical center through beam analysis can be achieved, for example, by analyzing the propagation path of the beam in a reference projection image and an actual projection image, and by comparing the changes in the beam's deflection angle and position.

[0095] The optical center coordinates of the lens under test can be either the position coordinates of the optical center of the lens under test in the first pixel coordinate system, or the position coordinates of the optical center of the lens under test in the lens's coordinate system. The first pixel coordinate system can be a coordinate system constructed based on the actual projected image. The lens's coordinate system is a coordinate system constructed based on the geometric parameters of the lens under test.

[0096] In some embodiments, the reference projection image includes a reference projection point corresponding to each of the plurality of preset beams, and the actual projection image includes an actual projection point corresponding to each of the plurality of preset beams.

[0097] For example, as shown in FIG3(a), the reference projection image includes a reference projection point corresponding to each of a plurality of preset beams, and as shown in FIG3(b), the actual projection image includes the actual projection point corresponding to each of the plurality of preset beams.

[0098] In these embodiments, step S2200, which determines the optical center position coordinates of the lens to be tested based on the actual projected image and the reference projected image, includes steps S2200.1 to S2200.2.

[0099] Step S2200.1: Determine the position offset value corresponding to each of the multiple preset beams based on the position coordinates of the actual projection point of each beam in the actual projection image and the position coordinates of the reference projection point in the reference projection image.

[0100] In this embodiment, the position coordinates of the actual projected point in the actual projected image and the position coordinates of the reference projected point in the reference projected image are identified. The position coordinates of the projected point here can be the center position coordinates of the projected point or the edge position coordinates of the projected point; there is no limitation here.

[0101] It is important to note that the position coordinates of the reference projection point and the position coordinates of the actual projection point must correspond. That is, when the position coordinates of the reference projection point are the center position coordinates of the reference projection point, the position coordinates of the actual projection point are also the center position coordinates of the actual projection point. When the position coordinates of the reference projection point are the edge position coordinates of the reference projection point, the position coordinates of the actual projection point are also the edge position coordinates of the actual projection point.

[0102] Based on the position coordinates of the actual projection point and the position coordinates of the reference projection point for each of the multiple preset beams, determine the position offset value for each of the multiple preset beams.

[0103] The position offset value corresponding to any beam can be the distance between the actual projection point and the reference projection point of the beam in the first pixel coordinate system. The position offset value can be composed of the horizontal (X-axis) offset and the vertical (Y-axis) offset in the first pixel coordinate system.

[0104] For example, as shown in FIG3(c), it shows the position offset of the reference projection point of the reference projection image in FIG3(a) and the actual projection point of the actual projection image in FIG3(b) in the horizontal direction of the first pixel coordinate, i.e., the X-axis direction.

[0105] In one embodiment, the position offset value corresponding to each of the multiple preset beams can be obtained by performing step S2200.1 using a focimeter.

[0106] Step S2200.2: Determine the optical center position coordinates of the lens to be tested based on the position offset value corresponding to each of the plurality of preset beams.

[0107] For example, the incident point of the beam corresponding to the smallest position offset value among multiple preset beams can be used as the optical center position coordinate of the lens under test.

[0108] For example, the prism power of each of the multiple preset beams can be determined based on the position offset value, effective optical thickness, and beam deflection angle of each beam. The projection point (reference projection point or actual projection point) corresponding to the minimum prism power can be used as the optical center position coordinate of the lens to be tested.

[0109] In some embodiments, step S2200.2, which determines the optical center position coordinates of the lens to be tested based on the position offset value corresponding to each of the plurality of preset beams, includes steps SA1 to SA3.

[0110] Step SA1: Obtain the effective optical thickness and beam deflection angle for each of the multiple preset beams.

[0111] In this embodiment, the effective optical thickness is the optical path length of the light beam in the lens under test. The beam deflection angle is the deflection angle of the light beam after passing through the lens under test. For each light beam, there is a corresponding effective optical thickness and a beam deflection angle.

[0112] In one embodiment, the effective optical thickness and beam deflection angle of each of a plurality of preset beams can be measured by a focimeter.

[0113] In this embodiment, the focimeter indirectly calculates the effective optical thickness by measuring the change in focal length of the light beam before and after passing through the lens under test. The focimeter uses a specific optical system (such as a beam splitter or a mirror) to measure the deflection angle of the light beam after passing through the lens under test.

[0114] Those skilled in the art should understand that the method of measuring the effective optical thickness and beam deflection angle of a beam using a focimeter is well known in the art and will not be elaborated here.

[0115] Step SA2: Determine the prism power of each of the multiple preset beams based on the position offset value, effective optical thickness, and beam deflection angle of each beam.

[0116] In this embodiment, prism diopter refers to the ability of the lens under test to deflect a light beam. For each of the multiple preset light beams, the prism diopter corresponding to each beam is calculated using the prism diopter calculation formula.

[0117] The formula for calculating prism power is as follows:

[0118]

[0119] Where Δ represents prism power, measured in diopters, and 1 diopter represents a beam deflection of 1 meter (1 meter radian). d is the beam position offset. 0 is the beam deflection angle, measured in degrees or radians (rad). L is the effective optical thickness, measured in meters (m).

[0120] Step SA3: Determine the optical center coordinates of the lens to be tested based on the prism power corresponding to each of the multiple preset beams.

[0121] In one example, the position coordinates of the projection point (reference projection point or actual projection point) corresponding to the beam with a prism power of 0 in the first pixel coordinates can be used as the optical center position coordinates of the lens to be tested.

[0122] In another example, the position coordinates of the projection point (reference projection point or actual projection point) of the beam with the smallest prism power among multiple preset beams can be used as the optical center position coordinates of the lens to be tested in the first pixel coordinates.

[0123] According to the embodiments of this application, the optical center position coordinates of the lens to be tested are determined based on the prism power corresponding to each of the multiple preset beams. Compared with the method of directly determining the optical center position coordinates based on the position offset value corresponding to each of the multiple preset beams, the accuracy of determining the optical center can be improved, thereby improving the accuracy of eccentricity detection.

[0124] Step S2300: Obtain the geometric center coordinates of the lens to be tested.

[0125] In this embodiment, the coordinates of the geometric center position can be determined based on a vision system, a contact measurement system, or other methods; no limitation is made here.

[0126] After the above system determines the geometric center coordinates of the lens to be tested, it can send the determined geometric center coordinates to the lens eccentricity detection device so that the lens eccentricity detection device can perform eccentricity detection.

[0127] In some embodiments, the lens eccentricity detection device can be a processor of a vision system, that is, the lens eccentricity detection device executes the relevant image processing algorithm of the vision system to determine the geometric center position coordinates of the lens to be detected.

[0128] In these embodiments, step S2300, which obtains the geometric center position coordinates of the lens to be tested, includes steps S2300.1 to S2300.3.

[0129] Step S2300.1: Acquire the visual image captured by the visual camera.

[0130] For example, such as Figure 4 As shown, the lens of the vision camera 4 is opposite to the focal plane of the image sensor 2 and is located above the light source 1, and has captured a visual image of the lens to be tested.

[0131] Step S2300.2: Identify the contour of the visual image and construct the contour model of the lens to be detected.

[0132] In this embodiment, an image processing algorithm is used to identify the outline edge of the lens to be detected in the visual image. After identifying the edge of the lens, a series of discrete points are taken on that edge. A mathematical model (such as polynomial fitting, circle fitting, or more complex curve fitting algorithms) is then used to fit these points, thereby constructing a contour model of the lens to be detected. During the fitting process, the least squares method or other optimization techniques can also be used to find the best-fit contour.

[0133] Step S2300.3: Determine the geometric center coordinates of the lens to be tested based on the contour model of the lens to be tested.

[0134] In this embodiment, the contour center, i.e. the geometric center, of the lens to be tested can be calculated by fitting the contour model.

[0135] For circular or elliptical lenses under test, the geometric center is the center point of the geometric shape. For lenses with more complex shapes, the contour center may be the centroid or centroid of the shape obtained through calculation.

[0136] Step S2400: Determine the eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates.

[0137] In this embodiment, when calculating the eccentricity value, it is necessary to first unify the coordinates of the optical center position and the geometric center position to the same coordinate system before calculating the eccentricity value of the lens to be tested.

[0138] The eccentricity value can be the eccentricity distance between the optical center and the geometric center of the lens under test, or it can be the horizontal and vertical coordinates of the eccentricity between the optical center and the geometric center of the lens under test; there is no limitation here.

[0139] In some embodiments, the optical center position coordinates are the position coordinates of the optical center in a first pixel coordinate system, and the geometric center position coordinates are the position coordinates of the geometric center in a second pixel coordinate system. The first pixel coordinate system is a coordinate system constructed based on the actual projected image of the focal plane of the image sensor, and the second pixel coordinate system is a coordinate system constructed based on the visual image captured by the visual camera.

[0140] In some embodiments, the first pixel coordinate system and the second pixel coordinate system are the same. That is, the position coordinates of the optical center in the first pixel coordinate system are the position coordinates of the optical center in the second pixel coordinate system, and the position coordinates of the geometric center in the second pixel coordinate system are the position coordinates of the geometric center in the first pixel coordinate system. In this case, there is no need to perform coordinate system transformation, and the eccentricity value can be calculated directly.

[0141] In other embodiments, the first pixel coordinate system and the second pixel coordinate system are different. In these embodiments, step S2400, which determines the eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates, includes steps S3100 to S3400.

[0142] Step S3100: Obtain the visual image of the lens to be tested captured by the vision camera.

[0143] Step S3200: Determine the coordinate transformation relationship between the first pixel coordinate system and the second pixel coordinate system based on the visual image and the actual projected image.

[0144] For example, the coordinate transformation relationship between the first pixel coordinate system and the second pixel coordinate system can be obtained based on the position coordinates of the center point of the visual image in the second pixel coordinate system and the position coordinates of the center point of the actual projected image in the first pixel coordinate system.

[0145] Step S3300: According to the coordinate transformation relationship, the position coordinates of the optical center in the first pixel coordinate system and the position coordinates of the geometric center in the second pixel coordinate system are converted into position coordinates in the same pixel coordinate system to obtain the transformed optical center position coordinates and the transformed geometric center position coordinates.

[0146] For example, coordinate transformations can be used to convert the optical center's coordinates in the first pixel coordinate system to its coordinates in the second pixel coordinate system, resulting in the converted optical center coordinates. Alternatively, coordinate transformations can be used to convert the geometric center's coordinates in the second pixel coordinate system to its coordinates in the first pixel coordinate system, resulting in the converted geometric center coordinates.

[0147] Step S3400: Determine the eccentricity value of the lens to be tested based on the converted optical center position coordinates and the converted geometric center position coordinates.

[0148] In some embodiments, step S2400, which determines the eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates, includes steps S5100 and S5200.

[0149] Step S5100: Determine the measured eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates.

[0150] For example, the optical center position coordinates are point O1 (x1, y1), the geometric center position coordinates are point O2 (x2, y2), and the measured eccentricity value is (△x, △y), where Δx = x1 - x2 and Δy = y1 - y2.

[0151] Step S5200: If the measured eccentricity value is less than or equal to the eccentricity threshold, the measured eccentricity value is taken as the eccentricity value of the lens to be tested.

[0152] In this embodiment, the eccentricity threshold can be a single value or a range of values; no limitation is made here.

[0153] The eccentricity threshold can be a preset eccentricity reference value between the optical center and the geometric center of the lens. It characterizes the acceptable error range for eccentricity detection, and can be specifically set based on multiple eccentricity detection values ​​obtained from eccentricity detection of multiple standard lenses.

[0154] According to the embodiments of this application, by setting an eccentricity threshold, when the measured eccentricity value is less than or equal to the eccentricity threshold, the measured eccentricity value is taken as the eccentricity value of the lens to be tested. This ensures that the lens is considered correct only when the eccentricity value is within an acceptable error range (i.e., less than or equal to the eccentricity threshold), thereby improving the accuracy of eccentricity detection.

[0155] In some embodiments, the step of determining the eccentricity threshold includes steps S6100 and S6200.

[0156] Step S6100: Obtain the eccentricity value corresponding to each of the multiple standard lenses.

[0157] In this embodiment, eccentricity detection can be performed on the multiple standard lenses using any of the methods described above. For example, eccentricity detection can be performed using steps S2100 to S2400 to obtain the eccentricity value of each standard lens. The eccentricity value of the standard lens is determined based on the optical center position coordinates and the geometric center position coordinates of the standard lens.

[0158] Step S6200: Determine the eccentricity threshold based on the multiple eccentricity values ​​corresponding to the multiple standard lenses.

[0159] In some examples, the eccentricity threshold is the maximum eccentricity distance value, which is set as the eccentricity threshold among the multiple eccentricity values ​​corresponding to the multiple standard lenses.

[0160] In other examples, the eccentricity threshold includes an x-axis eccentricity threshold and a y-axis eccentricity threshold. The x-axis eccentricity threshold can be determined based on multiple x-axis eccentricity values ​​corresponding to multiple standard lenses, and the y-axis eccentricity threshold can be determined based on multiple y-axis eccentricity values ​​corresponding to multiple standard lenses.

[0161] In some embodiments, after determining the measured eccentricity value in step S5100, the method further includes: if the measured eccentricity value is greater than the eccentricity threshold, outputting a detection error prompt message.

[0162] In this embodiment, error detection prompts can be output via text, voice, or other means; no specific limitations are imposed here.

[0163] In some cases, the eccentricity threshold may be set improperly, resulting in a detection error message. To avoid the problem of eccentricity detection errors and failure to output eccentricity detection results due to improper eccentricity threshold settings, this application provides a method for dynamically updating the eccentricity threshold.

[0164] Based on this, in some embodiments, after determining the measured eccentricity value in step S5100, the method further includes steps S7100 to S7300.

[0165] Step S7100: If the measured eccentricity value is greater than the eccentricity threshold, determine the eccentricity error value based on the measured eccentricity value and the eccentricity threshold.

[0166] For example, the measured eccentricity value is (Δx, Δy), and the eccentricity threshold is (Δx). max Δy max The eccentricity error value is (△x-Δx). max ,Δy-Δy max ).

[0167] Step S7200: If the eccentricity error value is within the preset tolerance range and the number of times the eccentricity error value appears in the historical eccentricity test is greater than or equal to the number threshold, the eccentricity threshold is corrected according to the eccentricity error value to obtain the corrected eccentricity threshold.

[0168] In this embodiment, a preset tolerance range is set. If the eccentricity error value is not within the preset tolerance range, it indicates that there is a hardware fault, such as the focal plane of the image sensor being tilted, or the camera of the vision camera being tilted. In this case, manual repair by maintenance personnel is required.

[0169] If the eccentricity error value is within the preset tolerance range, it indicates that the error may be caused by an improper eccentricity threshold setting. In this case, historical eccentricity detection data is obtained, which includes the eccentricity value and eccentricity error value corresponding to each historical eccentricity detection. It is then determined whether the eccentricity error value appears in the historical eccentricity detection data. If it does appear, the frequency of its occurrence is checked against a preset frequency threshold. If it does, the eccentricity threshold is adjusted.

[0170] A preset threshold for the number of attempts can be set, such as 100 or 50, and is not limited here.

[0171] Continuing with the example above, with a preset tolerance range of 0.5 and a threshold of 100 times, if the eccentricity error value (Δx - Δx) max ,Δy-Δy max If the eccentricity error value (0.10, 0.30) appears 102 times in the historical eccentricity detection data, then the eccentricity threshold will be corrected to (Δx). max +0.10, Δy max +0.30), which is the corrected eccentricity threshold.

[0172] Step S7300: If the measured eccentricity value is less than or equal to the corrected eccentricity threshold, the measured eccentricity value is taken as the eccentricity value of the lens to be tested.

[0173] In this embodiment, since the eccentricity threshold is corrected, the correct eccentricity detection result can be obtained by comparing the corrected eccentricity threshold with the measured eccentricity value. The problem of being unable to perform eccentricity detection due to improper eccentricity threshold setting is no longer displayed, thus improving the accuracy of eccentricity detection.

[0174] According to embodiments of this application, by acquiring the actual projected image formed by multiple preset light beams passing through the lens under test and reaching the focal plane of the image sensor, and determining the optical center coordinates of the lens under test based on the actual projected image and a reference projected image, the accuracy of determining the optical center can be improved. Furthermore, by acquiring the geometric center coordinates of the lens under test, and determining the eccentricity value of the lens under test based on the optical center coordinates and the geometric center coordinates, the accuracy of lens eccentricity detection can be improved.

[0175] <Device Embodiment>

[0176] Figure 5 This is a schematic block diagram of a lens eccentricity detection device 5000 according to an embodiment of the present invention.

[0177] In this embodiment, as Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of a lens eccentricity detection device 5000 according to one embodiment.

[0178] according to Figure 5 As shown, the lens eccentricity detection device 5000 of this embodiment may include a memory 5200 and a processor 5100.

[0179] Memory 5200 is used to store instructions that control processor 5100 to operate and execute the lens eccentricity detection method of any embodiment of the present invention. Those skilled in the art can design the instructions according to the disclosed scheme of the present invention. How the instructions control the processor to operate is well known in the art and will not be described in detail here.

[0180] <System Implementation Example>

[0181] Figure 6 This is a schematic block diagram of a lens eccentricity detection system 6000 according to an embodiment of the present invention.

[0182] In this embodiment, as Figure 6 As shown, Figure 6 This is a schematic diagram of the structure of a lens eccentricity detection system 6000 according to one embodiment.

[0183] according to Figure 6 As shown, the lens eccentricity detection system 6000 of this embodiment may include a light source 610, an image sensor 620, and a lens eccentricity detection device 630. The light source 610 is used to emit multiple preset light beams, and the image sensor 620 is used to acquire the actual projection image formed by the multiple preset light beams through the lens to be tested on its focal plane, and send it to the lens eccentricity detection device 630.

[0184] In one embodiment, the light source 610 is as follows: Figure 4 The area array beam shown.

[0185] In one embodiment, the system 6000 further includes a vision camera. The vision camera is opposite to the image sensor 620 and is located outside the light source 610.

[0186] For example, a vision camera includes a CCD image sensor and a lens.

[0187] This invention can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of the invention.

[0188] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0189] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0190] The computer program instructions used to perform the operations of this invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of the invention.

[0191] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0192] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0193] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0194] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions. It will be known to those skilled in the art that implementation in hardware, implementation in software, and implementation using a combination of software and hardware are equivalent.

[0195] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of the invention is defined by the appended claims.

Claims

1. A method for detecting the eccentricity of a lens, characterized in that, include: Acquire the actual projected image formed by multiple preset light beams passing through the lens to be tested and reaching the focal plane of the image sensor; The optical center coordinates of the lens to be tested are determined based on the actual projected image and the reference projected image; wherein, the reference projected image is the projected image formed by the plurality of preset beams reaching the focal plane of the image sensor without beam deflection; Obtain the geometric center coordinates of the lens to be tested; The eccentricity value of the lens to be tested is determined based on the optical center position coordinates and the geometric center position coordinates.

2. The method according to claim 1, characterized in that, The reference projection image includes a reference projection point corresponding to each of the plurality of preset beams, and the actual projection image includes an actual projection point corresponding to each of the plurality of preset beams. Determining the optical center coordinates of the lens to be tested based on the actual projection image and the reference projection image includes: Based on the position coordinates of the actual projection point of each of the plurality of preset beams in the actual projection image and the position coordinates of the reference projection point in the reference projection image, determine the position offset value corresponding to each of the plurality of preset beams; The optical center coordinates of the lens to be tested are determined based on the position offset value corresponding to each of the plurality of preset beams.

3. The method according to claim 2, characterized in that, Determining the optical center coordinates of the lens to be tested based on the position offset value corresponding to each of the plurality of preset beams includes: The effective optical thickness and beam deflection angle of each of the plurality of preset beams are obtained; wherein, the effective optical thickness is the optical path length of the beam in the lens to be tested; Based on the position offset value corresponding to each of the plurality of preset beams, the effective optical thickness, and the beam deflection angle, the prism power corresponding to each of the plurality of preset beams is determined; The optical center coordinates of the lens to be tested are determined based on the prism power corresponding to each of the plurality of preset beams.

4. The method according to claim 1, characterized in that, The process of acquiring the actual projected image formed by multiple preset light beams passing through the lens to be detected and reaching the focal plane of the image sensor includes: When the lens to be tested is parallel to the image sensor, an actual projected image is obtained by multiple preset light beams passing through the lens to be tested and reaching the focal plane of the image sensor.

5. The method according to claim 1, characterized in that, The optical center position coordinates are the position coordinates of the optical center in the first pixel coordinate system, and the geometric center position coordinates are the position coordinates of the geometric center in the second pixel coordinate system. Determining the eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates includes: Acquire visual images of the lens to be tested captured by a vision camera; Based on the visual image and the actual projected image, determine the coordinate transformation relationship between the first pixel coordinate system and the second pixel coordinate system; According to the coordinate transformation relationship, the position coordinates of the optical center in the first pixel coordinate system and the position coordinates of the geometric center in the second pixel coordinate system are transformed into position coordinates in the same pixel coordinate system to obtain the transformed optical center position coordinates and the transformed geometric center position coordinates. The eccentricity value of the lens to be tested is determined based on the converted optical center position coordinates and the converted geometric center position coordinates.

6. The method according to claim 1, characterized in that, Determining the eccentricity value of the lens to be tested based on the optical center position coordinates and the geometric center position coordinates includes: The measured eccentricity value of the lens to be tested is determined based on the optical center position coordinates and the geometric center position coordinates. If the measured eccentricity value is less than or equal to the eccentricity threshold, the measured eccentricity value shall be taken as the eccentricity value of the lens to be tested.

7. The method according to claim 6, characterized in that, The steps for determining the eccentricity threshold include: Obtain the eccentricity value corresponding to each of the multiple standard lenses; wherein, the eccentricity value of each standard lens is determined based on the optical center position coordinates and the geometric center position coordinates of the standard lens; The eccentricity threshold is determined based on the multiple eccentricity values ​​corresponding to the multiple standard lenses.

8. The method according to claim 6, characterized in that, The method further includes: If the measured eccentricity value is greater than the eccentricity threshold, the eccentricity error value is determined based on the measured eccentricity value and the eccentricity threshold. If the eccentricity error value is within the preset tolerance range and the number of times the eccentricity error value appears in historical eccentricity tests is greater than or equal to the number threshold, the eccentricity threshold is corrected according to the eccentricity error value to obtain the corrected eccentricity threshold. If the measured eccentricity value is less than or equal to the corrected eccentricity threshold, the measured eccentricity value shall be used as the eccentricity value of the lens to be tested.

9. A lens eccentricity detection device, comprising a memory and a processor, the memory for storing executable instructions; the processor for operating under the control of the instructions to perform the method as described in any one of claims 1 to 8.

10. A lens eccentricity detection system, comprising a light source, an image sensor, and a lens eccentricity detection device as described in claim 9, wherein the light source is used to emit a plurality of preset light beams, and the image sensor is used to acquire the actual projection image formed by the plurality of preset light beams through the lens to be tested on its focal plane, and send it to the lens eccentricity detection device.

Images