Ophthalmic lens surface microlens array and method for measuring the refractive power thereof

Abstract

This invention discloses a refractive measurement device and method for a microlens array on the surface of a spectacle lens. The refractive measurement device for the microlens array includes: a test module for accommodating a spectacle lens to be tested, the surface of which includes a microlens array; a light source module for providing a variable-aperture and collimated measurement beam; the measurement beam covers and passes through the microlens array; and a receiving module for simultaneously receiving the measurement beam after it has passed through the microlens array and obtaining its intensity distribution, determining the refractive value of each microlens based on the changes in the intensity distribution. This invention not only improves the accuracy of refractive measurement using a microlens array but also improves the measurement efficiency of the microlens array.

Description

Technical Field

[0001] This invention relates to the field of spectacle lens refractive power measurement, and more particularly to a device and method for measuring the refractive power of a microlens array on the surface of spectacle lenses. Background Technology

[0002] Myopia is an eye condition where distant objects cannot be seen clearly, but near objects can be seen clearly. The reason for this blurred vision is that distant objects are focused onto the area in front of the retina, appearing as blurry speckles on the retina. Scientific evidence confirms that the primary cause of myopia and its progression is the elongation of the eye axis, which is closely related to peripheral retinal defocus. When the focal point falls in front of the retina, it is called myopic defocus; when it falls behind the retina, it is called hyperopic defocus. In myopic eyes, the central retina exhibits myopic defocus, while the periphery exhibits hyperopic defocus. The eyeball has a characteristic of relying on peripheral retinal imaging to induce eyeball development, especially in adolescents under 18. If peripheral retinal imaging exhibits hyperopic defocus, the eyeball will further elongate, and myopia will continue to develop. Myopia has already become a serious problem affecting the growth of children and adolescents. Physiologically, myopia leads to changes in the shape of the eyeball, including axial length, corneal thickness, anterior chamber, and lens. In high myopia, the average thickness and width of the lens increase even more. These structural changes lead to changes in intraocular pressure. As the degree of refractive error increases, the intraocular pressure will continue to rise, and myopia will continue to worsen. If left unchecked, it will develop into high myopia.

[0003] The most traditional and direct way to correct myopia is to wear single-vision glasses. These glasses use the refractive power generated by the curved surfaces at the front and back of the lens to compensate for the eye's refractive error, allowing distant objects to be accurately imaged on the retina. However, while ordinary single-vision glasses can ensure clear vision at the macula of the retina, peripheral vision remains hyperopic. For teenagers, wearing single-vision glasses only guarantees clear vision for a short period and cannot effectively inhibit the further progression of myopia.

[0004] Orthokeratology lenses, a special type of rigid gas-permeable contact lens, improve vision by altering the convergence shape of the cornea. While they can inhibit myopia to some extent, as contact lenses, they can cause some damage to the cornea. Furthermore, since they are designed for children, maintaining proper eye hygiene is crucial for them, as infections are easily contracted. Defocus soft contact lenses, as a myopia control product, create peripheral myopic defocus through their annular refractive precipitate, which can inhibit myopia progression to some extent. However, to ensure image quality and reduce distortion, the amount of peripheral myopic defocus produced by defocus soft contact lenses is relatively small; therefore, their effect on myopia control is limited.

[0005] Defocused contact lenses have greater market potential due to their low cost and better myopia control effect. The fundamental reason for their better myopia control effect lies in the ring-shaped array of microlenses arranged on their front surface. These microlenses can provide peripheral myopia defocus of several diopters to the human eye, which is much greater than that of defocused soft contact lenses, effectively inhibiting the increase of myopia. In addition, for the microlens array with a certain distance between them, while providing peripheral myopia defocus, it does not significantly reduce the clarity of the human eye in observing the surroundings, ensuring the comfort of the wearer.

[0006] However, there has always been a lack of effective methods for measuring the actual refractive power of microlens arrays on the front surface of defocused lens frames. Traditional methods for measuring lens refractive power include focimeter scanning, Hartmann sensor measurement, Rownchi grating method, and Moiré deflection method. These methods all have significant drawbacks, such as being time-consuming to measure refractive power, or only being able to measure the average refractive power of the microlens array, resulting in low accuracy and significant errors in measuring the refractive power of individual microlenses. Traditional methods for measuring the refractive power of microlens arrays include the angle method, magnification measurement method, microscopic measurement method, sagittal measurement method, and relief depth measurement method. However, these methods are only applicable to the refractive power measurement of microlens arrays with a planar base surface. For the refractive power measurement of defocused lens frames, which have microlens arrays on curved surfaces, there is currently a lack of targeted and accurate measurement methods. First, the front surface of the defocusing lens has curvature and refractive properties. Furthermore, the rear surface of the defocusing lens has various shapes, including cylindrical, toric, and freeform surfaces, in addition to the typical spherical surface. These variations affect the overall intensity distribution of the test beam, significantly increasing the error in the refractive measurement of the microlenses on the front surface. Second, the refractive properties of the rear surface are significantly affected by the diffraction effect of the microlenses, which ranges from millimeters to hundreds of micrometers in diameter. This results in a noticeable deviation between the actual refractive value and the value calculated based on the actual microlens contour. Finally, measuring the refractive power of each microlens in the microlens array on the defocusing lens surface is time-consuming and inconsistent. Summary of the Invention

[0007] The main objective of this invention is to provide a refractive measurement device and method for a microlens array on the surface of a spectacle lens, aiming to solve the technical problem of how to improve the accuracy and efficiency of refractive measurement using a microlens array.

[0008] To achieve the above objectives, the present invention provides a refractive measurement device for a microlens array on the surface of a spectacle lens, comprising:

[0009] A test module for accommodating a spectacle lens to be tested; the surface of the spectacle lens to be tested includes a microlens array.

[0010] A light source module for providing a variable-aperture and collimated measurement beam; the measurement beam covers and passes through the microlens array;

[0011] The receiving module simultaneously receives the measurement beam after passing through the microlens array and obtains its intensity distribution, and determines the refractive value of each microlens based on the change in the intensity distribution.

[0012] Optionally, the receiving module includes a surface photoelectric sensor that moves along the optical axis of the measurement beam to obtain the intensity distribution at different moving positions or moving distances.

[0013] Optionally, the receiving module further includes a data processor, which obtains the movement position or movement distance corresponding to the intensity distribution.

[0014] Optionally, the intensity distribution includes the intensity of the light spot formed on the front surface of the lens.

[0015] Optionally, the test module further includes a compensation element, the front surface of which is complementary to the rear surface of the lens under test.

[0016] Optionally, the test module further includes a compensation element, the rear surface of which has the same radius of curvature as the front surface of the lens under test, or the rear surface of the compensation element is a plane.

[0017] Optionally, the refractive index of the compensation element is the same as that of the microlens array under test.

[0018] Optionally, the test module further includes a matching medium disposed between the lens under test and the compensation element; the matching medium is a fluid or a flexible solid material; the fluid is a refractive index matching liquid, and the flexible solid material can be a transparent plastic, rubber, or a highly viscous material such as glycerin, silicone oil, or silicone.

[0019] Optionally, the refractive measurement device of the microlens array further includes a sampling module for splitting the test beam into a first beam and a second beam.

[0020] Optionally, the light source module includes an adjustable aperture and a collimating lens.

[0021] Furthermore, to achieve the above objectives, this application also provides a method for refractive measurement of a microlens array on the surface of an ocular lens, comprising,

[0022] A collimated beam with a variable aperture is formed as a measurement beam;

[0023] Adjust the aperture of the measurement beam so that the measurement beam covers and passes through the array of microlenses to be measured;

[0024] Simultaneously, the measurement beam after passing through the microlens array is received, and its intensity distribution is obtained;

[0025] The refractive value of each microlens is determined based on the change in the intensity distribution.

[0026] The refractive measurement device and method for microlens arrays on the surface of spectacle lenses provided by the present invention, on the one hand, the light source module can form a collimated beam with a variable aperture. The beam aperture can be adaptively adjusted according to the size of the microlens array being measured, ensuring that the measurement beam can cover the microlens array being measured at one time. This enables simultaneous measurement of multiple microlenses in the microlens array without the need for individual illumination and measurement of each microlens. Therefore, it can achieve rapid measurement, avoid the problem of long measurement time in traditional measurement techniques for microlenses, and improve measurement efficiency.

[0027] On the other hand, by employing a compensation element to compensate for the refraction of the measurement beam by the rear surface of the microlens under test, interference from various surface types such as spherical, aspherical, cylindrical, complex, and freeform surfaces of the rear surface of the microlens under test, as well as processing errors, on the refractive power measurement is avoided, thus improving the accuracy of microlens refractive measurement. Secondly, the sampling module divides the measurement beam into a first beam and a second beam, using the second beam as a reference point to determine the intensity distribution of the first beam, eliminating interference from the light source itself and the measurement environment, further improving the measurement accuracy.

[0028] Third, by combining the use of flexible compensation elements to compensate the rear surface of the lens under test with focal length measurement of the front surface of the lens under test, the refractive power measurement of microlenses is realized when the surface parameters of the front and rear surfaces of the lens under test are unknown. This achieves the effect of rapid, comprehensive and accurate measurement of microlens parameters of any lens. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the refractive measurement device of the microlens array on the surface of the spectacle lens of the present invention;

[0030] Figure 2 (a) is a diagram showing the intensity distribution of the focused beam of the surface photoelectric sensor of the refractive measurement device of the microlens array on the surface of the eyeglass lens of the present invention at a certain moving distance; Figure 2 (b) is the intensity variation curve of the locally focused beam formed by three randomly selected microlenses when the surface photoelectric sensor moves at different distances;

[0031] Figure 3 This is a schematic diagram of another embodiment of the refractive measurement device for the microlens array on the surface of the spectacle lens of the present invention;

[0032] Figure 4a and 4b are schematic diagrams of the specific structure of the test module in the refractive measurement device of the microlens array on the surface of the eyeglass lens of the present invention.

[0033] Figure 5 (a) is the actual light intensity distribution map collected at a certain moving position when the rear surface of the lens under test is a spherical surface and no compensation element is added; Figure 5 (b) is the actual light intensity distribution map of the focal plane of the microlens acquired at a certain moving position when the rear surface of the lens under test is a free-form surface and no compensation element is added. Figure 5 (c) is the actual light intensity distribution obtained at a certain moving position when the radii of curvature of the front surface of the lens under test and the rear surface of the compensating element are equal, and the rear surface of the lens under test and the front surface of the compensating element are spherical surfaces with equal radii of curvature.

[0034] Figure 6 This is a schematic diagram of the third embodiment of the refractive measurement device for the microlens array on the surface of the spectacle lens of the present invention;

[0035] Figure 7 This is a schematic flowchart of the refractive measurement method for the microlens array on the surface of the spectacle lens of the present invention;

[0036] Figure 8 This is a graph showing the change in light intensity of locally focused beams formed by different microlenses before and after normalization, as the moving distance of the surface photoelectric sensor changes.

[0037] Explanation of icon numbers:

[0038] label name label name 1 Light source module 2 Shaping Module 3 Sampling module 4 Test Module 5 Receiver module 11 light source 21 Aperture 41 The lens to be tested 411 microlens array 51 Surface photoelectric sensor 1 52 Data processor 12 objective lens 13 small hole 22 collimating lens 43 Compensation elements 413 The back surface of the lens under test 431 Front surface of compensation element 412 Front surface of the lens under test 432 rear surface of compensation element 42 Refractive index matching liquid 31 Beam splitter 32 Surface photoelectric sensor 2 414 The "gap" between microlenses 45 Flexible materials 46 Transparent rigid flat plate

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0042] Example 1

[0043] Figure 1 A schematic diagram of an embodiment of a refractive measurement device for a microlens array on the surface of a spectacle lens provided by the present invention includes: a light source module 1, a test module 4, and a receiving module 5;

[0044] The light source module 1 outputs a collimated measurement beam with a variable aperture. It includes a light source 11 and a shaping module 2. The light source 11 can be a surface light source with uniform light intensity distribution. The shaping module 2 includes an adjustable aperture stop 21. The uniform beam emitted from the surface light source passes through the adjustable aperture stop to form a measurement beam matching the size of the microlens array under test. By adjusting the aperture of the adjustable aperture stop, it can be ensured that the measurement beam can cover the entire microlens array under test, guaranteeing that the subsequent receiving module 5 can simultaneously test the refractive power of all microlenses under test. This significantly shortens the refractive measurement time for all microlens arrays under test and improves measurement efficiency. The shaping module 2 may also include a beam expander or reducer (not shown in the figure) for collimating the beam, improving energy utilization, and reducing light energy loss.

[0045] Light source 11 can also be a point light source; see the following text for details on its structure. Figure 3 The description.

[0046] Test module 4 includes a lens under test 41, which includes a microlens array 411 to be tested. After the measurement beam passes through the microlens array 411, it is locally focused at each microlens under test, forming a locally focused beam. To shorten the focal length of the focused beam, a converging lens or a reflecting mirror (not shown in the figure) may be placed behind the lens under test 41.

[0047] The receiving module 5 is used to simultaneously receive the measurement beam after passing through the microlens array, that is, to simultaneously receive the locally focused beam of each microlens under test in the microlens array 41, and obtain its intensity distribution. The receiving module 5 includes a surface photoelectric sensor 51 and a data processor 52. The surface photoelectric sensor 51 is, for example, a surface CCD array, which moves from one end to the other along the optical axis of the measurement beam, and simultaneously records the light intensity distribution of the focused beam at different moving positions, that is, the change of intensity distribution with moving position or moving distance; while the data processor 52 obtains the moving position or moving distance of the surface photoelectric sensor 51 corresponding to the light intensity distribution.

[0048] The specific working process of the refractive measurement device for the microlens array is as follows: The aperture of the aperture stop 21 is controlled so that the light source module 1 emits a collimated measurement beam capable of covering the entire microlens array 411 under test. After transmission through the microlens array 411, the beam is focused by each microlens of the array, forming a locally focused beam, which is received by the surface photoelectric sensor 51 of the receiving module 5 at different moving positions. The initial position of the surface photoelectric sensor 51 can optionally be close to the lens 41 under test. Starting from the initial position, it gradually moves towards the other end along the optical axis of the focused beam, simultaneously recording the light intensity distribution at different moving positions.

[0049] See Figure 2(a) When the radii of curvature of the front and rear surfaces of the lens under test 41 are the same or both are zero, the actual focused beam intensity distribution is obtained at the same moving position. The M bright spots in the figure are formed by the M microlenses of the microlens array under test. Each microlens i will form a corresponding bright spot on the surface photoelectric sensor 51. The bright spots correspond one-to-one with the microlenses, and the number of bright spots is the same as the number of microlenses. The M bright spots constitute the focused beam intensity distribution.

[0050] For a specific microlens i in the microlens array 411 under test, the surface photoelectric sensor 51 will receive multiple bright spots with different light intensity values ​​corresponding to that microlens i at different moving positions or distances. It's easy to understand that N moving positions will result in N bright spots. The intensity reaches its maximum when the surface photoelectric sensor 51 is located at the focal point of that microlens i. (See also...) Figure 2 (b) In the figure, the horizontal axis represents the moving distance of the surface photoelectric sensor 51, and the vertical axis represents the intensity value of the bright spot formed by a certain microlens. For the same microlens i, different intensity values ​​are obtained at different moving distances, forming a curve showing the change of bright spot intensity value with moving distance. The three curves in the figure represent the curves of bright spot intensity change with moving distance formed by three different microlenses. From the trend of the curves in the figure, it can be seen that each curve has a maximum intensity value, and the corresponding moving distance is the focal length of the microlens.

[0051] The data processor 52 obtains multiple focused beam intensity distribution maps recorded by the surface photoelectric sensor 51 as it moves continuously, along with the corresponding movement positions. Each movement position corresponds to one focused beam intensity distribution map. Assuming the spatial coordinate position of microlens i is (x, y), based on its coordinate position, N intensity values ​​I1, I2, ... I1 are extracted from the N focused beam intensity distribution maps to represent the bright spot corresponding to microlens i. N Find the maximum value among these N intensity values, and determine the moving position or moving distance f of the surface photoelectric sensor 51 corresponding to the maximum intensity value. i That is, the focal length of microlens i, calculated according to the diopter formula D. i =1 / f i The refractive value of the i-th microlens is obtained. Here, i = 1, 2, ..., M, where M is the number of microlenses in the microlens array. The same process is applied to each of the M microlenses in turn to obtain the refractive values ​​of all microlenses.

[0052] Using a surface-type photoelectric sensor, the locally focused beam formed by each microlens in the microlens array under test can be received simultaneously to obtain an intensity distribution map. The data processor 52 processes the acquired intensity distribution map in a unified manner. Compared with the prior art, the present invention does not require measuring each microlens in the microlens array under test one by one, thus avoiding the time-consuming defect of measuring the refractive power of microlenses in the microlens array and improving the measurement efficiency.

[0053] It is foreseeable that the present invention is not only applicable to the measurement of microlens arrays of eyeglass lenses, but also applicable to the measurement of other optical elements having microlens arrays.

[0054] Example 2

[0055] See Figure 3 This is another embodiment of the present invention. In this embodiment, the light source module 1 may employ... Figure 1 In addition to the surface light source shown, a point light source can also be used, including a light source 11, an objective lens 12, a pinhole 13, and a shaping module 2. The beam emitted by the light source 11 is focused by the objective lens 12 onto the pinhole 13, forming a point light source with suitable brightness and uniformity after the pinhole 13. The light source 11 can be an incoherent light source or a coherent light source. Furthermore, the point light source can also be obtained directly from the light source 11 through the pinhole 13. The shaping module 2 includes an adjustable aperture 21 and a collimating lens 22. By adjusting the aperture of the adjustable aperture 21, the size of the measurement beam is adjusted. The collimating lens 22 can be a single lens or a combination of multiple lenses. The beam emitted by the point light source is converted by the shaping module 2 into a measurement beam with a variable aperture and collimation.

[0056] In this embodiment, the specific structure of the test module 40 is as follows: Figure 4 As shown in (a), the device includes a spectacle lens 41 under test with a microlens array 411 under test, and a compensation element 43. The compensation element 43 is made of the same material as the microlens array 411 under test. The surface profile of the front surface of the compensation element 43 is complementary to that of the spectacle lens 41 under test. During measurement, the rear surface 413 of the spectacle lens 41 under test and the front surface 431 of the compensation element are placed in contact. The complementary surface profile can be understood as follows: if the surface profile of the spectacle lens 41 under test is convex at a certain position, then the corresponding position of the compensation element is concave, so that after compensation, the spectacle lens 41 under test has uniformity in the refraction of the light beam at different positions on the same cross section. Preferably, the radius of curvature of the rear surface 432 of the compensation element is set to be equal to that of the front surface 412 of the spectacle lens 41 under test.

[0057] The compensation element 43 can compensate for the refraction of the light beam by the front and rear surfaces 413 of the microlens array 41 under test, so that the light at different positions on the cross section of the measurement beam has the same optical path after passing through the "microlens array under test + refractive index matching liquid + compensation element" structure. This makes the focusing characteristics of the light beam at each position basically consistent, which avoids the inconsistency in focusing at different positions of the microlens array 411 under test due to the surface shape of the microlens array under test and the presence of surface processing errors, thus improving the accuracy of microlens refractive power testing.

[0058] A refractive index matching fluid 42 may be included between the spectacle lens 41 and the compensation element 43 to eliminate air between the front surfaces of the spectacle lens 41 and the compensation element 43. This fluid has a refractive index equal to or approximately equal to that of the defocus lens 41 and the compensation element 43, further improving the accuracy of the microlens diopter measurement. A certain thickness of refractive index matching fluid is formed between the microlens array under test and the compensation element. Therefore, for the same compensation element, it can compensate for microlens arrays under test with varying surface shapes within a certain range, expanding the measurement range and improving the adaptability of this measuring device.

[0059] Reference Figure 5 This is an example of the actual light intensity distribution map collected by the surface photoelectric sensor 51. Figure 5 (a) When the rear surface 413 of the lens under test is spherical and no compensation element 43 is added, at a certain moving position, the surface photoelectric sensor 51 collects the actual light intensity distribution map of the focal plane of the microlens. Although the spacing between the focused light spots of each microlens is evenly distributed, the curvature of the rear surface affects the focusing of the microlens, resulting in a very large beam focusing distance or even causing the beam to diverge and not converge, and the calculated refractive value has a large error. Figure 5 (b) When the rear surface 413 of the lens under test is a freeform surface and no compensation element 43 is added, at a certain moving position, the surface photoelectric sensor 51 collects the actual light intensity distribution map of the focal plane of the microlens. Due to the influence of the freeform surface, the spacing between the focused light spots of each microlens is unevenly distributed, and each microlens has different focusing characteristics due to the influence of the freeform surface, resulting in a large error in the calculated refractive value. Figure 5 (c) When the radii of curvature of the front surface 412 of the lens under test and the rear surface 432 of the compensation element are equal, and the rear surface 413 of the lens under test and the front surface 431 of the compensation element are spherical surfaces with equal radii of curvature, at a certain moving position, the actual light intensity distribution map obtained shows that the focused light spot intensity of each microlens is basically equal and the spacing is uniformly distributed.

[0060] Compare Figure 5It can be seen that by using a compensation element to compensate for the refraction of the front and rear surfaces of the lens 41 under test, the interference of the front and rear surface shape and processing error of the lens 41 under test on the measurement beam is eliminated, and the ideal focused beam intensity distribution of the microlens array can be obtained, thereby improving the accuracy of microlens array refractive measurement.

[0061] Optionally, the rear surface 432 of the compensation element can be a sphere or a plane.

[0062] This measuring device is suitable for situations where the rear surface of the spectacle lens 41 to be tested has a spherical, cylindrical, complex, or freeform surface shape.

[0063] Example 3

[0064] In the above embodiments, optionally, a sampling module 3 is also included, located between the light source module 1 and the test module 3. The following description uses Embodiment 2 as an example. Of course, it can be understood that the sampling module 3 can also be applied in Embodiment 1 in the same way.

[0065] See appendix Figure 6 The sampling module 3 includes a beam splitter 31 and a surface photoelectric sensor 32, used to split the test beam into a first beam and a second beam. The second beam serves as a reference light to calibrate the intensity distribution of the first beam, which refers to the intensity values ​​of the test beam at various positions on a certain cross-section. The surface photoelectric sensor 32 receives the intensity distribution of the second beam. Due to the potential non-uniformity of the intensity distribution of the light source itself, and stray light from the external environment, the intensity of the measurement beam can also become non-uniform, all of which can interfere with the measurement. Therefore, this invention uses a reference light to calibrate the measurement beam to compensate for the non-uniformity of the beam incident on the spectacle lens 41 under test, thereby eliminating interference from the light source itself or the external environment and further improving the measurement accuracy.

[0066] Figure 6 This is a specific embodiment of sampling module 3. A beam splitter 31, such as a semi-transparent mirror or a dichroic mirror, splits the measurement beam into reflected and transmitted light with a certain intensity ratio. The reflected light serves as the reference light, and the transmitted light serves as the measurement light. Alternatively, other beam splitting methods can be used, such as fiber optic beam splitters or gratings.

[0067] One specific implementation of the calibration is as follows: The data processor 52 is connected to the surface photoelectric sensor 41 and the surface photoelectric sensor 32 respectively, and obtains the light intensity distribution of the second beam and the intensity distribution map of the locally focused beam. The pixel values ​​at the same position of the two are subtracted or divided to eliminate the interference of the uneven intensity distribution of the measurement beam on the measurement.

[0068] Of course, the calibration process is not limited to the above methods. Other conventional methods in the field can be used, including linear function transformation, logarithmic function transformation, etc.

[0069] Example 4

[0070] Furthermore, based on the above embodiments of the refractive measurement device for a microlens array on the surface of a spectacle lens according to the present invention, a method for refractive measurement of a microlens array on the surface of a spectacle lens according to the present invention is proposed, referring to... Figure 7 The flowchart, the method includes:

[0071] Step S10: A collimated beam with a variable aperture is formed as a measurement beam;

[0072] The light source module 1 is used to form a collimated beam with a variable aperture, which is used as a measurement beam, thus enabling it to be applied to microlens arrays of different sizes.

[0073] Step S20: Adjust the aperture of the measurement beam so that the measurement beam covers and passes through the microlens array to be measured;

[0074] The light source module 1 includes a shaping module. By adjusting the aperture of the adjustable aperture in the shaping module, the aperture of the measurement beam can be adjusted to ensure that the measurement beam covers the entire array of microlenses under test. This allows the subsequent receiving module 5 to simultaneously measure the refractive power of all microlenses under test, thereby improving measurement efficiency.

[0075] Step S20 further includes: Step S21, dividing the measurement beam into a first beam and a second beam, and receiving the intensity distribution of the second beam. The second beam serves as a reference beam for calibrating the intensity distribution of the first beam, thereby eliminating inhomogeneities in the measurement beam caused by the light source or external environment and improving measurement accuracy.

[0076] Step S20 further includes: step S22, performing refractive compensation on the microlens array to be tested.

[0077] A compensation element 43 is used to compensate for the refraction of the light beam by the front and / or rear surface 413 of the spectacle lens under test. The compensation element 43 is made of the same material as the microlens array 41 under test, and the surface profile of the front surface of the compensation element 43 is complementary to that of the rear surface of the spectacle lens under test. After compensation, the refraction of the light beam by the microlens array under test at different positions on the same cross section is uniform, thereby eliminating the interference caused by the surface profile or processing error of the rear surface of the spectacle lens under test. The radius of curvature of the rear surface of the compensation element 43 is equal to that of the front surface of the spectacle lens under test, eliminating the interference caused by the refraction of the light beam by the front surface of the spectacle lens under test.

[0078] A refractive index matching fluid is also included between the microlens array 41 under test and the compensation element to eliminate air between them. Preferably, the radius of curvature of the rear surface 432 of the compensation element is set to be equal to that of the front surface 412 of the spectacle lens 41 under test. After compensation, the optical path of light at different positions on the measurement beam cross section is consistent after passing through the "microlens array under test + refractive index matching fluid + compensation element" structure, thereby making the focusing characteristics of the beam at each position basically consistent. This avoids the inconsistency in focusing at different positions of the microlens array 41 under test due to the surface shape of the microlens array under test and the existence of surface processing errors, thus improving the accuracy of microlens diopter testing.

[0079] Optionally, the rear surface 332 of the compensation element can be a sphere or a plane.

[0080] Step S30: Simultaneously receive the measurement beam after passing through the microlens array and obtain its intensity distribution;

[0081] When the measurement beam passes through the array of microlenses under test, it is focused by each microlens, forming multiple locally focused beams. A receiving module simultaneously receives these multiple locally focused beams to construct an intensity distribution map, enabling rapid measurement of the microlens array. The receiving module uses a surface-type photoelectric sensor for receiving.

[0082] For the same receiving location, the intensity distribution map is as follows: Figure 5 As shown, the light beam is formed by focusing the measurement beam through the microlens array under test. Each microlens forms a bright spot, and the number of bright spots in the intensity distribution diagram is the same as the number of microlenses in the microlens array under test.

[0083] Step S30 further includes: Step S31, calibrating the intensity distribution of the locally focused beam. Due to the potential inhomogeneity of the intensity distribution of the light source itself, and stray light from the external environment, the intensity of the measurement beam can also become uneven, all of which can interfere with the measurement. By using a second beam separated from the measurement beam as a reference beam to calibrate the intensity distribution of the first beam, interference from the light source itself or the external environment is eliminated, further improving the measurement accuracy.

[0084] The calibration process can be as follows: obtain the intensity distribution of the second beam and the intensity distribution of the locally focused beam, and perform subtraction or division operations on the pixel values ​​at the same locations of the two. Of course, it is not limited to the above method; the calibration process can employ other conventional methods in this field, including linear function transformation, logarithmic function transformation, etc.

[0085] Step S40: Determine the refractive value of each microlens based on the change in intensity distribution.

[0086] During the aforementioned receiving process, the position or distance of the surface photoelectric sensor 51 in the receiving module 5 is constantly changing, thus the obtained intensity distribution varies with the moving position or moving distance. For a specific microlens i in the microlens array 411 under test, the surface photoelectric sensor 51 will receive multiple bright spots with different light intensity values ​​corresponding to that microlens i at different moving positions or moving distances. It is easy to understand that N moving positions will result in N bright spots with different light intensity values. The final obtained intensity distribution maps are N images, each containing M bright spots formed by M microlenses, with each microlens corresponding to one bright spot.

[0087] Step S40 further includes: step S41, normalizing the intensity values ​​of the N bright spots formed by the same microlens.

[0088] Specifically, based on the spatial coordinates (x, y) corresponding to the center point of the i-th microlens, the intensity values ​​I corresponding to the N bright spots formed by the i-th microlens are extracted from the N intensity distribution maps obtained from the moving positions or distances of the N different photoelectric sensors. n For n = 1, 2, ..., N, we obtain the curve I(z) based on the change of the intensity value with the moving distance, and then normalize the curve.

[0089] I'(z)=I(z) / I n

[0090] Among them, I n I(z) represents the intensity value at the position corresponding to the i-th microlens in the intensity distribution matrix of the reference beam; I(z) is the curve of the intensity at the center of the i-th microlens as a function of the moving distance z; I'(z) is the curve of the normalized intensity of the i-th microlens as a function of the moving distance z.

[0091] See Figure 8 , Figure 8 This graph shows the relationship between the light intensity at the center of different microlenses and the moving distance of the image receiver. The three curves in the graph represent bright spots formed by three different microlenses, and their intensity values ​​change with the moving distance of the photoelectric sensor. Figure 8 (Above) shows the actual light intensity value as the photoelectric sensor moves a certain distance; Figure 8 (Below) shows the change in intensity value as the photoelectric sensor moves after normalization. As can be seen from the figure, after normalization, the maximum light intensity values ​​of the different curves are equal.

[0092] Step S40 further includes: step S42, obtaining the maximum intensity of the focused beam of each of the microlenses under test;

[0093] The intensity of the received light beam is maximized when the surface-type photoelectric sensor is located at the focal length of a microlens. Record the intensity values ​​of N bright spots formed by the i-th microlens at N different positions, compare these N intensity values, and find the maximum intensity value. For example... Figure 8 As shown below, the light intensity distribution at the center of the i-th microlens after normalization first increases and then decreases with the change in moving distance, indicating the existence of a maximum intensity value. The moving position or distance corresponding to this maximum intensity value is the focal point or focal length of the corresponding microlens. By performing the same operation on different microlenses sequentially, the maximum intensity value of each microlens can be obtained. Understandably, conventional methods in this field can be used to obtain the maximum intensity value, such as graphical methods or curve fitting methods.

[0094] Step S40 further includes: step S43, obtaining the refractive value of each of the microlenses to be tested based on the maximum intensity value.

[0095] The movement distance fi corresponding to the maximum intensity is the focal length of the i-th microlens. The refractive value of the i-th microlens can be obtained from the formula:

[0096] D i =1 / f i

[0097] Where fi is the moving distance corresponding to the maximum light intensity at the center of the i-th microlens, which is the focal length of the i-th microlens; D i This represents the refractive power of the microlens.

[0098] By analogy, the refractive power of each microlens in the microlens array under test can be calculated.

[0099] Furthermore, if the rear surface of the compensating element is spherical or planar, the formula for calculating the refractive value of the microlens is:

[0100] D i =1 / f i -D'

[0101] Where D' represents the equivalent refractive power of the "thick lens" formed by the base of the lens under test and the compensation element. Example 5

[0102] When the refractive power of the front and rear surfaces of the optical element 41 under test is unknown, the following apparatus and method are used for measurement. In this embodiment, the specific structure of the test module 40 is as follows: Figure 4As shown in (b), the difference from other embodiments is that the compensation element is composed of a transparent rigid plate 46 and a flexible material 45 attached thereto. The transparent rigid plate 46 can be a transparent glass plate, plexiglass, etc., and the flexible material 45 can be a transparent plastic, rubber, or a highly viscous material such as glycerin, silicone oil, or silicone. The rigid plate and the flexible material are preferably materials with the same or similar refractive index as the optical element 41 to be tested.

[0103] The refractive measurement method includes the following steps:

[0104] In step S100, a compensation element comprising a flexible material is used to compensate the rear surface 413 of the optical element under test 41 to be planar. By applying appropriate pressure, the flexible material 45 is made to fit tightly against the rear surface of the optical element under test 41, making their surface shapes consistent. At the same time, the air between the flexible material 45 and the optical element under test 41 is eliminated. Thus, without prior knowledge of the refractive power of the rear surface of the optical element under test 41, its surface shape can be made uniform, thereby eliminating the interference caused by the inconsistency of refractive power at various points on the rear surface to the measurement.

[0105] Step S200: Measure the refractive power of the front surface 412 of the optical element 41 under test, i.e., measure the refractive power of the "gap" 414 between the microlenses. The measuring device is the same as that used for measuring the refractive power of the microlenses. Because the refractive power of the "gap" 414 between the microlenses differs, the focal point formed after converging the aligned measurement beam is at a different position on the optical axis of the measurement beam. By moving the position of the surface photoelectric sensor 32 along the optical axis, the light spot formed by the "gap" 414 between the microlenses on the front surface of the optical element 41 under test is received. The location where the light spot intensity reaches its maximum is the focal point. Based on the position of the surface photoelectric sensor 32 along the optical axis at this time, the focal length of the front surface of the optical element 41 under test can be obtained, and its refractive power can be calculated using a formula, denoted as D1.

[0106] Step S300: Measure the refractive power of each microlens. The measuring apparatus and method are the same as in other embodiments.

[0107] Step S400: Calculate the true refractive power of each microlens. The calculation formula is as follows:

[0108] D i =1 / f i -D1-D2

[0109] Among them, f i D is the focal length of the i-th microlens; i D1 represents the true refractive power of the microlens, D2 represents the refractive power of the front surface of the optical element 41 under test, and D2 represents the equivalent refractive power of the "thick lens" formed by the rear surface of the optical element under test and the compensation element.

[0110] In this embodiment, the order of steps S20 and S30 can be interchanged.

[0111] The present invention achieves the following beneficial effects:

[0112] On the one hand, the light source module can form a collimated beam with a variable aperture. The beam aperture can be adaptively adjusted according to the size of the microlens array under test, ensuring that the measurement beam can cover the microlens array under test at one time. This enables simultaneous measurement of multiple microlenses in the microlens array without the need for individual illumination and measurement of each microlens. Therefore, it can achieve rapid measurement, avoiding the problem of long measurement time in traditional measurement techniques for microlenses and improving measurement efficiency.

[0113] On the other hand, by employing a compensation element to compensate for the refraction of the measurement beam by the rear surface of the microlens under test, interference caused by various surface shapes such as spherical, aspherical, cylindrical, complex, and freeform surfaces of the rear surface of the microlens under test, as well as processing errors, is avoided in the refractive power measurement, thus improving the accuracy of microlens refractive measurement. Secondly, the sampling module divides the measurement beam into a first beam and a second beam, using the second beam as a reference point to determine the intensity distribution of the first beam, eliminating interference from the light source itself and the measurement environment, and improving the measurement accuracy.

[0114] Third, by combining the use of flexible compensation elements to compensate the rear surface of the lens under test with focal length measurement of the front surface of the lens under test, the refractive power measurement of microlenses is realized when the surface parameters of the front and rear surfaces of the lens under test are unknown. This enables rapid, comprehensive and accurate measurement of microlens parameters for any lens.

[0115] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0116] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0117] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0118] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. An apparatus for measuring the refractive power of a surface microlens array of an ophthalmic lens, characterized in that, include: A test module for accommodating a spectacle lens to be tested, the surface of which includes a microlens array; A light source module for providing a variable-aperture and collimated measurement beam; the measurement beam covers and passes through the microlens array; The receiving module simultaneously receives the measurement beam after passing through the microlens array and obtains its intensity distribution, and determines the refractive value of each microlens based on the change in the intensity distribution; The receiving module includes a surface photoelectric sensor, which moves along the optical axis of the measurement beam to obtain the intensity distribution at different moving positions or moving distances. The refractive measurement device further includes a sampling module disposed between the light source module and the test module, used to split the measurement beam into a first beam and a second beam, wherein the second beam serves as a reference light for calibrating the intensity distribution of the first beam; The receiving module further includes a data processor, which obtains the moving position or moving distance corresponding to the intensity distribution. Among them, for microlens i of the microlens array, the surface photoelectric sensor will receive multiple bright spots with different light intensity values ​​corresponding to microlens i at different moving positions or moving distances, forming a curve of the intensity value of the bright spot changing with the moving distance. The moving distance corresponding to the maximum intensity value in the curve is the focal length of the microlens. The data processor acquires multiple focused beam intensity distribution maps recorded by the surface photoelectric sensor as it moves continuously, as well as the corresponding moving positions, with each moving position corresponding to one focused beam intensity distribution map; For microlens i in the microlens array, based on the spatial coordinates of microlens i, N intensity values ​​of the bright spot corresponding to microlens i are extracted from the multiple focused beam intensity distribution maps. The maximum intensity value is then determined from these N values, and the moving position or distance f of the surface-type photoelectric sensor corresponding to the maximum intensity value is determined. i The focal length of microlens i is used, and the diopter is calculated according to the formula D. i =1 / f i We obtain the refractive value of microlens i, where i = 1, 2, ..., M, and M is the number of microlenses in the microlens array.

2. The refractive measurement device of claim 1, wherein, The test module also includes a compensation element, the front surface of which is complementary to the rear surface of the lens under test.

3. The refractive measurement device of claim 1, wherein, The test module also includes a compensation element, the rear surface of which has the same radius of curvature as the front surface of the lens under test, or the rear surface of the compensation element is a plane.

4. The refractive measurement device of claim 2 or 3, wherein, The test module also includes a matching medium disposed between the optical element under test and the compensation element.

5. The refractive measurement device of claim 4, wherein, The matching medium is a fluid or a flexible solid material.

6. The refractive measurement device of claim 1, wherein, The intensity distribution includes the intensity of the light spot formed on the front surface of the lens.

7. A method of measuring the power of a surface microlens array of an ophthalmic lens, characterized in that, The refractive measurement method for the microlens array on the surface of the spectacle lens, applied to the refractive measurement device for the microlens array on the surface of the spectacle lens as described in claim 1, includes the following steps: A collimated beam with a variable aperture is formed as a measurement beam; Adjust the aperture of the measurement beam so that the measurement beam covers and passes through the array of microlenses to be measured; Simultaneously, the measurement beam after passing through the microlens array is received, and its intensity distribution is obtained; The refractive value of each microlens is determined based on the change in the intensity distribution.

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