Depth sensing lens and depth sensing lens module array

Abstract

The present application provides a depth perception lens, characterized in that the depth perception lens sequentially includes at least one optical element along the optical path from the object side to the image side. The at least one optical element is arranged along the optical axis of the depth perception lens. The at least one optical element includes a first superlens, and a first microstructure is provided on one surface of the first superlens. The focal length of the depth perception lens is f, the entrance pupil diameter of the depth perception lens is EPD, and the overall mechanical length of the depth perception lens is TTL, satisfying the following relational expressions: 1.53 < f / EPD < 1.60, 2.33 < TTL / EPD < 3.20. Within this range, the depth perception lens of the present application can achieve an enlarged aperture while shortening the overall mechanical length of the optical system, so as to facilitate the integration of the depth perception lens into various terminals in a smaller size.

Description

Technical Field

[0001] The present application relates to a depth perception lens, and more particularly to a depth perception lens that combines a refractive system and a diffractive system. Background Art

[0002] Depth sensing modules provide spatial perception capabilities and are widely used in smartphones and head-mounted display technologies (AR, VR, or MR). In recent years, smartphone and head-mounted display technologies have developed rapidly, and lightweight and compact structures are the future development trend.

[0003] Existing technologies use Time of Flight (TOF) technology for depth perception. TOF technology works by transmitting laser light at a transmitter and receiving it at a receiver. A computer uses the time difference between transmission and reception to generate depth data related to the object, thereby constructing a three-dimensional image. Depth-sensing lenses on the receiver are typically used specifically for 3D recognition, and within the industry, depth-sensing modules are also being miniaturized and lightweighted.

[0004] Mobile devices such as smartphones or tablets require a depth perception module that is lightweight, compact, and capable of capturing high-resolution depth information. However, in the prior art, the depth perception lens at the receiving end generally uses a refractive lens. The refractive lens uses the light deflection effect to focus the laser signal from the transmitting end. However, due to the structural defects of the refractive lens, the size of the depth perception module in the prior art cannot be well controlled. As photoelectric sensors become more compact and powerful, the resolution of depth information is also required to be improved. The refractive depth perception module used in mobile phones and AR devices has difficulty in achieving a lower height while having a large focusing capability.

[0005] As a mainstream technology in the 3D sensing field, TOF technology offers advantages such as long distance, high precision, and anti-interference, making it the preferred choice for facial and gesture recognition. Consumer electronics, especially AR / VR, prioritize wearing and user comfort, placing extremely light and thin demands on the size and weight of optical systems.

[0006] Current TOF lenses generally use 3-piece or 4-piece traditional refractive lenses, some of which even include glass lenses, resulting in relatively high material and assembly costs. To obtain a depth perception lens with high imaging quality (such as a TOF lens with a large aperture), multiple spherical lenses or several aspherical lenses are usually required in the refractive depth perception module to correct related aberrations. However, this also brings many negative effects. For example, if multiple spherical lenses are used, it will increase the size and length of the lens itself, and the better the imaging correction, the more spherical lenses are needed, and the two cannot be well balanced; if aspherical lenses are used, or aspherical lenses are used in combination with spherical lenses, the manufacturing cost will be greatly increased; it is difficult for existing depth perception lenses to meet the standards of controllable large aperture and aberrations under the conditions of thin and light volume and low cost. Summary of the Invention

[0007] In view of the above problems, the present application provides a depth perception lens, characterized in that the depth perception lens sequentially includes at least one optical element along the optical path from the object side to the image side. The at least one optical element is arranged along the optical axis of the depth perception lens. The at least one optical element includes a first metasurface lens, and a first microstructure is provided on one surface of the first metasurface lens. The focal length of the depth perception lens is f, the entrance pupil diameter of the depth perception lens is EPD, and the overall mechanical length of the depth perception lens is TTL, satisfying the following relational expressions: 1.53 < f / EPD < 1.60, 2.33 < TTL / EPD < 3.20. Within this range, the depth perception lens of the present application can achieve an enlarged aperture while shortening the overall mechanical length of the optical system, thereby facilitating the integration of the depth perception lens into various terminals in a smaller size.

[0008] The present application provides a depth perception lens module array, which includes a transmitting module for transmitting laser signals to the outside, and a receiving module for receiving the returned laser signals. The receiving module includes the depth perception lens of the present application. The overall mechanical length of the depth perception lens is TTLJ, and the overall mechanical length of the transmitting module is TTLF, satisfying 0.95 < TTLJ / TTLF < 1.05. The overall mechanical length of the depth perception lens is less than that of the transmitting module, thereby facilitating the integration of the depth perception lens module array into various terminals in a smaller size.

[0009] Through the understanding of the subsequent description and drawings, the further objectives and advantages of the present application will be fully reflected. Brief Description of the Drawings

[0010] The above and other purposes, features, and advantages of the present application will become more apparent through a more detailed description of the embodiments of the present application in conjunction with the accompanying drawings. The accompanying drawings are intended to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the drawings, the same reference numerals generally represent the same components or steps.

[0011] Figure 1 The optical system structure diagram of one embodiment of the present application is shown.

[0012] Figure 2 FIG. 1 shows a schematic structural diagram of a metalens according to an embodiment of the present application.

[0013] Figure 3 A schematic diagram of the design of a metalens according to an embodiment of the present application is shown.

[0014] Figure 4 The optical system structure diagram of another embodiment of the present application is shown.

[0015] Figure 5 An optical performance diagram of another embodiment of the present application is shown.

[0016] Figure 6 The figure shows the structure of an optical system according to another embodiment of the present application.

[0017] Figure 7 The optical performance diagram of yet another embodiment of the present application is shown.

[0018] Figure 8 The figure shows the structure of an optical system according to another embodiment of the present application.

[0019] Figure 9 The optical performance diagram of yet another embodiment of the present application is shown.

[0020] Figure 10 The figure shows the structure of an optical system according to another embodiment of the present application.

[0021] Figure 11 The optical performance diagram of yet another embodiment of the present application is shown.

[0022] Figure 12 The figure shows the structure of an optical system according to another embodiment of the present application.

[0023] Figure 13 The optical performance diagram of yet another embodiment of the present application is shown.

[0024] Figure 14 is a structural diagram of an optical system according to yet another embodiment of the present application.

[0025] Figure 15 2 is a structural diagram showing the depth perception lens module array of the present application. DETAILED DESCRIPTION

[0026] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0027] In the description of the present invention, it should be noted that, for directional words, such as the terms "center", "horizontal", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions and positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0029] The terms "comprises" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, product or apparatus.

[0030] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct, contact, or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0031] Attachment Figure 1Fig. 0 shows an embodiment of a depth perception lens of the present application. The depth perception lens 1 includes at least one optical element in sequence from the object side to the image side along the optical path. The at least one optical element is arranged along the optical axis of the depth perception lens 1. The at least one optical element includes a first metasurface lens 10, and a microstructure is provided on one side surface of the first metasurface lens 10. The distribution of the microstructure satisfies the following formula:

[0032]

[0033] where C1i represents the binary surface coefficient of the metasurface lens, normR1 represents the normalized radius, and R1 is the radial position of the metasurface lens.

[0034] The focal length of the depth perception lens 1 is f, the entrance pupil diameter of the depth perception lens 1 is EPD, and the overall mechanical length of the depth perception lens 1 is TTL. It satisfies the following relationship: 1.53 < f / EPD < 1.60, so that the optical system of the depth perception lens 1 has a relatively large aperture number, which is beneficial to increasing the light input and further improving the imaging quality. In addition, the depth perception lens 1 satisfies 2.33 < TTL / EPD < 3.20. Within this range, the depth perception lens 1 of the present application can achieve an enlarged aperture while shortening the overall mechanical length of the optical system, so as to facilitate the integration of the depth perception lens 1 into various terminals in a smaller size.

[0035] In the present application, the first metasurface lens 10 includes a first substrate 101 and a first microstructure 102. The first microstructure 102 is provided on one side of the first substrate 101. The first substrate 101 can be made of glass or amorphous silicon material (amorphous silicon, a-Si). It can be manufactured by a semiconductor-level process in a batch transfer manner. The first microstructure 102 in the present application is made of amorphous silicon material (amorphous silicon, a-Si). The first microstructure 102 in the present application is a nano-column array with different diameters, so as to realize the diffraction of incident light in the gaps with a size of several hundred nanometers between the nano-columns, thereby realizing the phase modulation of the incident light.

[0036] The microstructures in the present application can also adopt shapes such as cylinders, rings, and squares. Since these shapes are easy to process, they can be replicated in batches. The first microstructure 102 in the present application can be a nano-structure arranged in an array-like regular pattern. The nano-structure is preferably square, and the nano-structure can be hexagonal. A nano-cylinder can be provided at the center of each square or hexagonal nano-structure. Those skilled in the art should know that in the manufacturing process, the first microstructure 102 can be provided on one side surface of the first substrate 101, or on the other side surface of the substrate, or the first microstructure 102 can be provided on both surfaces of the substrate.

[0037] In this embodiment, the aperture stop 50 is disposed in front of the first substrate 101, thereby achieving the effect of reducing the optical height by placing the aperture in front. In this embodiment, the color filter 40 is disposed behind the first microstructure 102 to achieve the effect of filtering light of a specific wavelength.

[0038] The first microstructure 102 of the present application has the same height along the optical axis O direction. The first microstructure 102 is rotationally symmetrically arranged by multiple nanostructures. Along the radial direction of the first microstructure 102, the nanostructures at different positions from the center to the maximum radius are different. The difference in the nanostructures can be different in size or shape, thereby achieving different phase responses of the nanostructures at different radial positions to light, so that the first microstructure 102 can achieve phase modulation from light near the optical axis to edge light.

[0039] Those skilled in the art will understand that a metalens is a two-dimensional planar lens composed of a metasurface structure, while a refractive lens is a three-dimensional lens made of transparent material, consisting of two spherical surfaces or a spherical surface and a flat surface. A metalens utilizes a metasurface with subwavelength thickness to focus light, thereby achieving optical transformation; a refractive lens, based on the laws of light refraction, achieves focusing or imaging by altering the light's propagation path. Those skilled in the art will also understand that the same unit structure responds differently to light fields at different incident angles. A metalens is designed based on the response of its micro- and nanostructured units to the light field, which is known as its "angular response." Inconsistency in angular response can cause the actual phase of the metalens to deviate from the designed target phase at non-perpendicular incidence, thereby introducing additional wavefront aberrations. The magnitude of wavefront aberrations directly affects the performance of the optical system, including resolution, depth of focus, and contrast. This problem primarily arises during the design and fabrication of the metalens. Designers need to accurately predict and adjust the angular response of each micro- and nanostructured unit to ensure the overall performance of the metalens in real-world applications. Furthermore, the manufacturing process must be sufficiently precise to ensure that the actual shape and size of each micro- and nanostructured unit conform to the designed value. In the present application, in order to overcome this "angle response" problem, the first microstructure 102 of the first metalens 10 is selected to have a unit structure in which the relative phase remains stable within the direction angle of 0-40 degrees and the azimuth angle of 0-180 degrees and the transmittance is greater than 0.98, thereby ensuring that the performance of the optical system, such as resolution, depth of focus, contrast, etc., is relatively excellent.

[0040] Attachment Figure 2The schematic diagram of the structure of the first microstructure of the first metalens of the present application is shown. In this embodiment, the first microstructure 102 adopts a basic structure of 9 unit columns. In the present application, 9 unit columns can be selected or other numbers can be selected. When the incident light changes within the direction angle of 0-40 degrees and the azimuth angle of 0-180 degrees, the phase of the light passing through the unit column changes less than the design value, so as to achieve the advantage of a wide incident angle and have the desired phase modulation effect within a specific direction angle and azimuth angle range.

[0041] The first microstructures 102 are arranged periodically, and the phase distribution of the first superlens 10 is rotationally symmetric along the radial direction of the first superlens 10, thereby achieving full transmission of light through the first superlens 10, further achieving the modulation effect of the first superlens 10 on light, thereby achieving a phase adjustment effect on light.

[0042] Those skilled in the art will appreciate that the metalens in this application uses a gradual, continuous surface to change the direction of the light beam. The substrates of the metalens in this application are flat, and the period of the microstructures provided on the substrate is very small. Therefore, the surface of the metalens is highly discrete, and the metalens can adjust the direction of the light beam by introducing a phase change.

[0043] Simply put, the superlens uses the phase gradient to change the direction of the light beam, which is completely different from a conventional refractive lens. Since the unit structure of the superlens is very discrete, the unit structure of this application designs the gap between the pillars as a whole. Since the gap between the pillars can play a diffraction role, each circle of microstructures in this application needs to be calculated, and the step distance between each circle of microstructures is about 300nm, which can improve the applicability of the superlens of this application, thereby increasing the aperture of the superlens and achieving a large aperture effect.

[0044] The transmittance of the metalens designed in this application is above 0.98, thereby ensuring that the light transmittance of the metalens is high and meeting the clear imaging requirements of the depth perception lens 1.

[0045] Reference Attachment Figure 3 As shown, the metalens in this application is based on the response of the microstructure to the light field. The inventors found that the same unit structure responds differently to light fields at different incident angles. As a result, when the incidence is non-perpendicular, the actual phase of the metalens deviates from the designed target phase. This introduces additional wave aberrations, resulting in a decrease in the performance of the optical system. To address this problem, this application improves the selection and testing method of the metalens unit structure. In addition to scanning the unit structure size, it also adds scanning of the azimuth and direction angles.

[0046] Attached Figure 3The first picture above, starting from the left, shows the phase change of microstructure unit columns of different diameters when parallel light enters at an azimuth angle of 0-40 degrees. When the incident angle is not 0 degrees, there are different degrees of deviation from the target phase. This situation shows that microstructure unit columns of different diameters will also have different phase changes under the same incident angle. From the first picture starting from the left, we can know that microstructures of specific diameters can meet the phase modulation of longer wavelengths.

[0047] Attached Figure 3 The second picture from the left shows the prior art method for selecting different microstructures. Before the improvement, the actual phase of the metalens deviated from the target phase at different angles.

[0048] Attached Figure 3 The third and fourth figures from the left are schematic diagrams of the azimuth and direction angles of the microstructures of this application. In order to achieve a scanning range covering all possible incident directions in the entire hemispherical space, all microstructures in the metalens are scanned at specific azimuth and direction angles. The microstructures of this application meet the conditions of phase uniformity and amplitude transmittance as close to 1 as possible within the specific ranges of 0-40 degrees of direction angle and 0-180 degrees of azimuth angle.

[0049] In this application, at least one group of 8-9 unit microstructures is selected to meet the 0-2Pi phase coverage. The phase of the 8-9 unit structure maintains the target phase within the incident angle range expressed in a specific range, and the amplitude transmittance is close to 1. Figure 3 In the bottom diagram, the angle θ with the dotted line in the diagram is They represent the azimuth and direction angles, respectively. Within the stated range of incident angles, the designed metalens meets the ideal phase requirements, does not introduce additional phase difference, and ensures high focusing efficiency.

[0050] In this application, the depth perception lens 1 acts as a receiver for the laser with a wavelength of 940nm. The depth perception lens 1 can receive the light with a wavelength of 940nm reflected from the object. During depth perception, the calculator establishes the depth data of the object based on the time difference between emission and reception. The microstructure designed in this application can make the phase shift of the light in the working band cover the range of 0-2Pi, which can increase the effect of precision recognition. Figure 2 It illustrates a structural design method of the present application, which mainly designs a basic number and arrangement of unit columns according to the selected working wavelength light (940nm light in this application). In this application, 8-9 unit columns can be selected. When the incident angle of these 8-9 unit columns changes from 0 to 40 degrees, the phase of the light passing through the unit columns does not change.

[0051] In this application, the field of view angle of the depth perception lens 1 is greater than 80 degrees. The depth perception lens 1 in this application has the characteristics of a field of view angle greater than 80 degrees, a large aperture Fno <= 1.6, and a small total length TTL <= 3 mm, so as to be able to reduce the size of the depth perception lens 1, and further enable the depth perception lens 1 to be integrated into various terminals with a smaller size.

[0052] More specifically, the working wavelength of the depth perception lens 1 in this application is in the near-infrared band of 940nm ± 10nm. Therefore, the depth perception lens 1 in this application can receive light with a wavelength of 940nm reflected from an object. When performing depth perception, the calculator establishes depth data of the object based on the time difference from transmission to reception. In this embodiment, the size of the metasurface lens is relatively small, enabling a miniaturized design.

[0053] Still referring to the attached Figure 1 As shown, in this embodiment, the first metasurface lens 10 includes a first substrate 101. The substrate is generally made of glass and can transmit light of different wavelengths, especially light with a wavelength of 940nm ± 10nm. It is provided on one surface of the substrate and has first microstructures 102 with a special shape and arranged in a regular array. The first microstructures 101 can be square or regular hexagonal. At the center of each square or hexagonal microstructure unit, a micro-nano structure is provided. According to the requirements of different embodiments, the first microstructures 102 can be provided on the first surface of the first substrate 101, or the second surface, or on both the upper and lower surfaces of the substrate.

[0054] In this embodiment, the cross-section of the first microstructures 102 in the height direction can be circular, square, hollow ring, hollow square, cross-shaped, etc. According to different requirements, the microstructures can be set into different shapes to meet different design needs.

[0055] The overall length of the mechanism of the depth perception lens 1 in this application is TTL, which satisfies the following conditions:

[0056] 2.05 < TTL < 2.958. Satisfying this relationship can help compress the overall length of the optical system and make the lens structure more compact.

[0057] The overall length of the mechanism of the depth perception lens 1 in this application is TTL, and the maximum imaging height of the optical system of the depth perception lens 1 is ImgH, which can satisfy the following conditions:

[0058] 1.76 < TTL / ImgH < 2.24. This relationship can enable the optical system of the depth perception lens 1 in this application to have a larger imaging area and at the same time make the overall length of the optical system shorter.

[0059] The maximum imaging height in the optical system of the depth perception lens 1 of the present application is ImgH, and the focal length of the optical system of the depth perception lens 1 of the present application is f, which satisfies the following conditions:

[0060] 0.82 < ImgH / f < 0.92. Satisfying this relationship can help expand the field angle of the optical system, thereby increasing the range of the画面acquired by the depth perception lens 1, and further being able to expand the shooting range of the depth perception lens 1, so as to improve the..., so that the optical system can be made...

[0061] The distance from the image-side surface of the lens / metalens closest to the image plane in the optical system to the imaging plane on the optical axis is BFL, and the entrance pupil diameter of the optical system is EPD, which can satisfy the following conditions:

[0062] 0.65 < BFL / EPD < 1.49. This relationship can help balance the length of the back focal length and the aperture size in the optical system, enabling the optical system to take into account the imaging brightness while shortening the back focal length.

[0063] Reference appendix Figure 6 As shown, in some other embodiments, the depth perception lens 1 further includes a second metalens 20. The second metalens 20 further includes a second substrate 201 and a second microstructure 202. The second microstructure 202 is disposed on one side surface of the second substrate 201. The distribution of the second microstructure 202 satisfies the foregoing content, and the second microstructure 202 also satisfies the conditions that the phase uniformity and amplitude transmittance are as close as possible to 1 within the direction angle of 0 - 40 degrees and the azimuth angle of 0 - 180 degrees of the incident light, so as to weaken the influence of the "angle response". The second microstructure 202 of the second metalens 20 is a nanostructure extending on a plane perpendicular to the optical axis, and the basic shape of the nanostructure is a symmetric structure such as a cylinder, a ring or a square. The first microstructure 102 of the first metalens 10 covers a range of 0 - 2pi for the phase transformation of the incident light. The second microstructure 202 is a nanostructure with a relative phase that remains stable and a transmittance greater than 0.98 within the direction angle of 0 - 40 degrees and the azimuth angle of 0 - 180 degrees of the incident light. The second microstructure 202 is a nanostructure with a relative phase that remains stable and a transmittance greater than 0.98 within the direction angle of 0 - 40 degrees and the azimuth angle of 0 - 180 degrees of the incident light, so that the designed metalens meets the ideal phase requirements, does not introduce additional phase differences, and ensures a high focusing efficiency.

[0064] Specifically, the distribution of the second microstructure satisfies the following formula:

[0065]

[0066] It should be noted that the text contains some inaccuracies and unclear expressions in the original Chinese, which may affect the accuracy of the translation. For example, "从而能够的扩大该深度感知镜头1的拍摄范围" and "从而能够使得该光学系统," seem to be incomplete or incorrect sentences. The translation is made as accurately as possible based on the existing text.Wherein, C2i represents the binary surface coefficient of the second metalens, normR2 represents the normalized radius of the second metalens, R2 represents the radial position of the second metalens, the second microstructure of the second metalens is a nanostructure extending on a plane perpendicular to the optical axis, and the basic shape of the nanostructure is a symmetrical structure of a cylinder, a ring or a square. The phase transformation of the first microstructure of the first metalens to the incident light covers the range of 0-2pi. The second microstructure is a nanostructure in which the relative phase remains stable within the direction angle of 0-40 degrees and the azimuth angle of 0-180 degrees of the incident light and the transmittance is greater than 0.98. The second microstructure is a nanostructure in which the relative phase remains stable within the direction angle of 0-40 degrees and the azimuth angle of 0-180 degrees of the incident light and the transmittance is greater than 0.98.

[0067] In some embodiments, the depth sensing lens 1 includes an aperture stop 50, a first metalens 10, a second metalens 20, and a color filter 40 in order from the object side to the image side along the optical path. The first microstructure 102 is disposed on the image side of the first metalens 10, and the second microstructure 202 is disposed on the image side of the second metalens 20.

[0068] Table 1 below gives the numerical ranges of various conditional formulas of this application and the actual numerical values ​​of various embodiments:

[0069]

[0070] Various specific embodiments of the present application are given below.

[0071] <Example 1>

[0072] Attachment Figure 4 A first embodiment of the depth sensing lens 1 of the present application is illustrated. In this embodiment, the depth sensing lens 1 includes an aperture stop 50, a first metalens 10, and a color filter 40, in order from the object side to the image side, along the optical path. A first microstructure 102 is provided on the image side of the first metalens 10. In this embodiment, a single microstructure is provided on a single optical surface of a single lens, resulting in a simple structure and ease of assembly. The depth sensing lens 1 of this embodiment has a high assembly yield.

[0073] The first super lens 10 has positive optical power to achieve light focusing and imaging.

[0074] In this embodiment, the illumination of the depth perception lens 1 can reach over 90%, and the MTF of 1 / 4Nq is greater than 0.8 at the peak values ​​of F1-F9. In this application, Nq refers to the Nyquist test frequency, and 1 / 4Nq here refers to 1 / 4 of the Nyquist test frequency, that is, 12.5lp / mm. The peak value of 0.8 means that the MTF peak value is greater than 0.8. F1 represents the center field of view, and F9 represents the 0.8 field of view. Although the depth perception lens 1 of this embodiment has a simple structure, its optical performance is still maintained at a high level, which can provide consumers with a better user experience on a small-sized lens.

[0075] In this embodiment, the depth sensing lens 1 has a TTL of 2.2 mm and a short total optical length, making it easy to miniaturize. Table 1 below shows the parameters of Example 1:

[0076]

[0077] The phase information of the first superlens 10 in this embodiment is shown in Table 2 below:

[0078] Table 2 Superlens Central wavelength 940nm Normalized radius 1mm C1 -2.7029E+03 C2 8.8815E+02 C3 -2.7906E+03 C4 4.6864E+03 C5 -4.2462E+03 C6 1.8410E+03 C7 -7.2016E+01 C8 -2.5250E+02 C9 8.8906E+01 C10 -9.3228E+00

[0079] <Example 2>

[0080] Attachment Figure 6 A second embodiment of the depth sensing lens of the present application is illustrated. In this embodiment, the depth sensing lens 1 includes, in order from the object side to the image side, an aperture stop 50, a first metalens 10, a second metalens 20, and a color filter 40. The image side surface of the first metalens 10 is provided with a first microstructure 102, and the image side surface of the second metalens 20 is provided with a second microstructure 202. In this embodiment, the combination of the first metalens 10 and the second metalens 20 can share the optical power required by each metalens, thereby reducing optical distortion. Furthermore, in this embodiment, optical imaging can be achieved using the first metalens 10 and the second metalens 20, thereby ensuring a short total optical length. The first metalens 10 has a positive optical power to achieve light convergence for imaging, and the second metalens 20 also has a positive optical power to further converge light for imaging.

[0081] In this embodiment, the illumination of the depth perception lens 1 can reach over 90%, and the MTF of 1 / 4Nq is greater than 0.8 at the peak values ​​of F1-F9. In this application, Nq refers to the Nyquist test frequency, and 1 / 4Nq here refers to 1 / 4 of the Nyquist test frequency, that is, 12.5lp / mm. The peak value of 0.8 means that the MTF peak value is greater than 0.8. F1 represents the center field of view, and F9 represents the 0.8 field of view. Although the depth perception lens 1 of this embodiment has a simple structure, its optical performance is still maintained at a high level, which can provide consumers with a better user experience on a small-sized lens.

[0082] In this embodiment, the TTL of the depth sensing lens 1 is 2.958 mm, and the total optical length is short, so it is easy to miniaturize. Table 3 below shows the parameters of Example 2:

[0083]

[0084] The phase information of the first superlens 10 and the second superlens 20 in this embodiment is shown in Table 4 below:

[0085]

[0086]

[0087] <Example 3>

[0088] Attachment Figure 8 A third embodiment of the depth-sensing lens of the present application is illustrated. In this embodiment, the depth-sensing lens 1 includes, in order from the object side to the image side, an aperture stop 50, a first metalens 10, a second metalens 20, and a color filter 40. The image-side surface of the first metalens 10 is provided with a first microstructure 102, and the image-side surface of the second metalens 20 is provided with a second microstructure 202. In this embodiment, the combination of the first metalens 10 and the second metalens 20 can share the optical power required by each metalens, thereby reducing optical distortion. Furthermore, in this embodiment, optical imaging can be achieved using the first metalens 10 and the second metalens 20, thereby minimizing the total optical length.

[0089] The first super lens 10 has a positive optical power to achieve light convergence and imaging. The second super lens 20 also has a positive optical power, thereby further converging the light to achieve imaging.

[0090] In this embodiment, by sacrificing distortion, the illumination of the outermost field of view (field 1) of the depth perception lens 1 in this embodiment is made ≥ 60%, thereby achieving MTF greater than 0.95 and 0.8 at 12.5 lp / mm and 25 lp / mm in the F9 field of view, respectively, ensuring good performance in the remaining fields of view.

[0091] In this embodiment, the TTL of the depth sensing lens 1 is 2.958 mm, and the total optical length is short, so it is easy to miniaturize. The following Table 5 shows the parameters of Example 3:

[0092]

[0093] The phase information of the first superlens 10 and the second superlens 20 in this embodiment is shown in Table 6 below:

[0094] Table 6 Super Lens 1 Super Lens 2 Central wavelength 940nm 940nm Normalized radius 1mm 1mm C1 -1.6237E+03 -1.6868E+03 C2 1.5060E+03 1.0006E+03 C3 -1.7701E+04 -2.6068E+03 C4 8.8331E+04 4.9016E+03 C5 -2.4182E+05 -3.6749E+03 C6 3.4081E+05 -4.0887E+02 C7 -1.4149E+05 1.6097E+03 C8 -2.2517E+05 2.3395E+02 C9 3.0409E+05 -7.7753E+02 C10 -1.0894E+05 1.8939E+02

[0095] <Example 4>

[0096] Attachment Figure 10 A fourth embodiment of the depth-sensing lens 1 of the present application is illustrated. In this embodiment, the depth-sensing lens 1 includes, in order from the object side to the image side, an aperture stop 50, a first metalens 10, a first lens 30, and a color filter 40 along the optical path. A first microstructure 102 is provided on the object side of the first metalens 10. This embodiment utilizes the first metalens 10 to assist in optical imaging, thereby achieving a shorter overall optical length.

[0097] In this embodiment, the aperture stop 50 is placed in front of the entire optical system, which is beneficial to reducing the total optical length of the entire optical system.

[0098] The first super lens 10 has a positive optical power to achieve light convergence and imaging. The first lens 30 also has a positive optical power, so as to further converge the light to achieve imaging.

[0099] The first lens 30 includes a first lens object-side surface 301 and a first lens image-side surface 302 , wherein the first lens object-side surface 301 is concave and the first lens image-side surface 302 is convex, thereby improving the resolution of the depth perception lens 1 .

[0100] In this embodiment, the distortion is sacrificed so that the illumination of the outermost field of view (field 1) of the depth perception lens 1 in this embodiment is ≥50%.

[0101] In this embodiment, a first microstructure 102 is provided on the object-side surface of the first metalens 10, ensuring that the first metalens 10 has a relatively small effective aperture. In this embodiment, the effective diameter of the first microstructure 102 on the object-side surface of the first metalens 10 is only 1.04 mm. Since the first microstructure 102 has a positive optical power, the size of the first metalens 10 is relatively small, thereby reducing the manufacturing cost of the first metalens 10. As a result, MTFs in the F9 field of view at 12.5 lp / mm and 25 lp / mm are greater than 0.95 and 0.8, respectively, ensuring good performance in the remaining fields of view.

[0102] In this embodiment, the TTL of the depth sensing lens 1 is 2.958 mm, and the total optical length is short, so it is easy to miniaturize. Table 7 below shows the parameters of Example 4:

[0103]

[0104] The phase information of the first superlens 10 in this embodiment is shown in Table 8 below:

[0105] Table 8 Superlens Central wavelength 940nm Normalized radius 1mm C1 -1.5140E+03 C2 3.8308E+03 C3 -3.7518E+04 C4 1.9347E+05 C5 -4.7276E+05 C6 7.4950E+05 C7 1.9170E+06 C8 -8.3919E+06 C9 -4.0122E+07 C10 1.2528E+08

[0106] In this embodiment, the aspheric sag coefficient of the first lens 30 is as shown in Table 9:

[0107] Table 9 The object-side surface of the first lens 30 The image side surface of the first lens 30 K -4.7541E+01 -9.3469E-01 A4 -4.5158E-01 -9.6100E-02 A6 4.4948E-01 4.9608E-01 A8 2.7860E+00 -8.1220E-01 A10 -3.2816E+00 -1.1625E+00 A12 1.1053E+00 4.3298E+00 A14 2.8462E+01 7.5662E+00 A16 -6.1687E+01 -1.3979E+01 A18 0 0 A20 0 0

[0108] <Example 5>

[0109] Attachment Figure 12 A fifth embodiment of the depth-sensing lens 1 of the present application is illustrated. In this embodiment, the depth-sensing lens 1 includes, in order from the object side to the image side, an aperture stop 50, a first lens 30, a first metalens 10, a second lens 60, and a color filter 40. The object side surface of the first metalens 10 is provided with a first microstructure 102. This embodiment utilizes the first metalens 10 to assist in optical imaging, thereby reducing the overall optical length. In this embodiment, the aperture stop 50 is positioned in front of the entire optical system, which helps reduce the overall optical length of the entire optical system.

[0110] The first lens 30 includes a first lens object-side surface 301 and a first lens image-side surface 302 , wherein the first lens object-side surface 301 is convex and the first lens image-side surface 302 is concave, thereby improving the resolution of the depth perception lens 1 .

[0111] The second lens 60 includes a second lens object-side surface 601 and a second lens image-side surface 602 , wherein the second lens object-side surface 601 is concave and the second lens image-side surface 602 is convex, thereby improving the resolution of the depth perception lens 1 .

[0112] The object side surface 601 of the second lens is an aspherical surface, and the image side surface 602 of the second lens is also an aspherical surface, thereby reducing defects such as spherical aberration and coma.

[0113] The first metalens 10 has a positive optical power to achieve light convergence and imaging. The first lens 30 also has a positive optical power to further converge the light to achieve imaging. The second lens 60 has a negative optical power to reduce aberration.

[0114] In this embodiment, by providing two lenses, the effective focal length of the depth perception lens 1 is increased while maintaining a substantially unchanged overall optical length, compared to the solution of Example 4. Furthermore, by providing two lenses with a combination of positive and negative optical powers, the field of view of the depth perception lens 1 can be increased.

[0115] In this embodiment, a first microstructure 102 is provided on the object-side surface of the first metalens 10, ensuring that the first metalens 10 has a relatively small effective aperture. In this embodiment, the effective diameter of the first microstructure 102 on the object-side surface of the first metalens 10 is only 1.13 mm. Since the first microstructure 102 has a positive optical power, the size of the first metalens 10 can be kept relatively small, thereby reducing the manufacturing cost of the first metalens 10.

[0116] In this embodiment, the TTL of the depth sensing lens 1 is 2.19 mm, and the total optical length is short, so it is easy to miniaturize. Table 10 below shows the parameters of Example 5:

[0117]

[0118]

[0119] The phase information of the first metalens 10 in this embodiment is shown in Table 11 below:

[0120] Table 11 First super lens 10 Central wavelength 940nm Normalized radius 1mm C1 -1.9132E+03 C2 -1.4782E+03 C3 7.9478E+03 C4 2.2227E+03 C5 -7.9240E+04 C6 3.1460E+05 C7 -4.1475E+05 C8 6.3806E+05 C9 -3.0101E+05 C10 7.0834E+05

[0121] In this embodiment, the aspheric sag coefficients of the first lens 30 and the second lens 60 are as shown in Table 12:

[0122]

[0123] <Example 6>

[0124] Attachment Figure 14 A sixth embodiment of the depth-sensing lens 1 of the present application is illustrated. In this embodiment, the depth-sensing lens 1 includes, in order from the object side to the image side, an aperture stop 50, a first lens 30, a first metalens 10, and a second lens 60. A first microstructure 102 is provided on the object side of the first metalens 10. This embodiment uses the first metalens 10 to assist in optical imaging, thereby achieving a shorter overall optical length.

[0125] In this embodiment, the aperture stop 50 is placed in front of the entire optical system, which is beneficial to reducing the total optical length of the entire optical system.

[0126] The first lens 30 includes a first lens object-side surface 301 and a first lens image-side surface 302 , wherein the first lens object-side surface 301 is convex and the first lens image-side surface 302 is concave, thereby improving the resolution of the depth perception lens 1 .

[0127] The second lens 60 includes a second lens object-side surface 601 and a second lens image-side surface 602 , wherein the second lens object-side surface 601 is concave and the second lens image-side surface 602 is convex, thereby improving the resolution of the depth perception lens 1 .

[0128] The object side surface 601 of the second lens is an aspherical surface, and the image side surface 602 of the second lens is also an aspherical surface, thereby reducing defects such as spherical aberration and coma.

[0129] The first metalens 10 has a positive optical power to achieve light convergence and imaging. The first lens 30 also has a positive optical power to further converge the light to achieve imaging. The second lens 60 has a negative optical power to reduce aberration.

[0130] In this embodiment, by providing two lenses, the effective focal length of the depth-sensing lens 1 can be increased while maintaining a substantially unchanged overall optical length. Furthermore, by providing two lenses with a combination of positive and negative optical powers, the field of view of the depth-sensing lens 1 can be increased.

[0131] In this embodiment, a color filter film 70 is further provided on the image-side surface of the first metalens 10. This color filter film 70 is an infrared cutoff film that filters infrared light, thereby ensuring that the captured image is close to the perception of the human eye. Compared to other embodiments in which a color filter 40 is provided, the color filter film 70 provided on the image-side surface of the first metalens 10 in this embodiment can reduce the number of color filters 40 in the optical system, thereby enabling the first metalens 10 to replace the color filter 40. This further reduces the overall optical length of the depth perception lens 1 in this embodiment, achieving a size advantage of an overall optical length of less than 2.05 mm.

[0132] Attachment Figure 15The diagram shows the situation in which the transmitting module 1001 and the receiving module 1002 in this application are mounted on a terminal such as a mobile phone. In order to make the mobile phone beautiful, mobile phone manufacturers often require that the end faces of visible optoelectronic modules, such as camera modules and depth perception modules, are set as flush as possible, so as to obtain a neater visual experience. In this embodiment, the total length of the receiving module 1002 and the transmitting module 1001 in the depth perception module array is made within 2.5 mm, and the sizes of the two are relatively close, which can ensure that when the depth perception module array is mounted on the mobile phone, the upper end faces of the receiving module 1002 and the transmitting module 1001 can be relatively flush, so as to obtain a neater appearance of the camera module array.

[0133] In this application, the transmitting module 1001 and the receiving module 1002 need to be installed in a terminal such as a mobile phone. For the sake of the aesthetics of the mobile phone, mobile phone manufacturers often require that the end faces of the visible optoelectronic modules, such as the camera module and the depth perception module, are set as flush as possible, so as to obtain a relatively neat visual experience. In this embodiment, the total length of the receiving module 1002 and the transmitting module 1001 in the depth perception lens module array 100 can be made within 2.5mm, and the sizes of the two are relatively close. This can ensure that when the depth perception lens module array 100 is installed on the mobile phone, the upper end faces of the receiving module 1002 and the transmitting module 1001 can be relatively flush, thereby obtaining a relatively neat appearance.

[0134] In this embodiment, the TTL of the receiving module 1002 is 2.2 mm. Since the total length of the depth sensing lens 1 in this embodiment is relatively small, it is easier to implement a miniaturized design.

[0135] Attachment Figure 15 A depth sensing lens module array 100 is illustrated, which includes a transmitting module 1001, which is used to transmit laser signals to the outside world, and a receiving module 1002, which is used to receive returned laser signals. The receiving module 1002 includes any one of the depth sensing lenses 1 described above in this application. The total length of the receiving module 1002 is TTLJ, and the total length of the transmitting module 1001 is TTLF, which satisfies the following condition: 0.95<TTLJ / TTLF<1.05.

[0136] In this embodiment, the total length (TTL) of the depth perception lens 1 of the receiving module 1002 is 2.2 mm, and the total length (TTLF) of the transmitting module 1001 is 2.3 mm. In this embodiment, the total length of the depth perception lens is smaller than the total length of the transmitting module, thereby achieving the effect of reducing the height.

[0137] Generally speaking, the structure of the transmitting module 1001 is simple, and it only includes a light source chip and a lens group of 1-2 lenses. In the prior art, the height of the transmitting module 1001 is much smaller than the height of the receiving module 1002. However, with the design of the small-size depth perception lens 1 of the present application, the height difference between the receiving module 1002 and the transmitting module 1001 can be shortened, so as to obtain a depth perception lens module array 100 with a flush surface. This can improve the aesthetics of the depth perception lens module array and at the same time improve the accuracy of depth perception.

[0138] This application also discloses optical performance diagrams corresponding to the optical design, and provides optical performance diagrams of field curvature, optical performance diagrams of distortion, and optical performance diagrams of illumination.

[0139] In this application, field curvature refers to the situation where the intersection of the entire light beam does not coincide with the ideal image point. Although a clear image point can be obtained at each specific point, the entire image plane is a curved surface. In the optical performance diagram of field curvature, the horizontal axis represents the image height, and the vertical axis represents the magnitude of the field curvature.

[0140] In this application, distortion refers to the degree of distortion of the image formed by an optical system relative to the object itself. In the optical performance diagram of distortion, the horizontal axis represents the image height and the vertical axis represents the distortion magnitude.

[0141] In this application, illuminance refers to the density of light intensity in a specified direction. In the optical performance diagram of illuminance, the horizontal axis represents the size of the field of view, and the vertical axis represents the illuminance ratio.

[0142] This application provides the following optical performance diagrams of each embodiment. Overall, the embodiments of this application have high optical performance, can obtain high-quality optical information, and the illumination of the entire field of view is relatively reasonable.

[0143] Figure 5 Graphs of field curvature, distortion, and illumination for Example 1 are shown.

[0144] Figure 7 Graphs of field curvature, distortion, and illumination for Example 2 are shown.

[0145] Figure 9 Graphs of field curvature, distortion, and illumination for Example 3 are shown.

[0146] Figure 11 Graphs of field curvature, distortion, and illumination for Example 4 are shown.

[0147] Figure 13 Graphs of field curvature, distortion, and illumination for Example 5 are shown.

[0148] The above describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and description merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A depth perception lens, characterized in that: The depth perception lens includes at least one optical element in sequence from the object side to the image side along the optical path, wherein the at least one optical element is arranged along the optical axis of the depth perception lens, wherein the at least one optical element includes a first metalens, the first metalens has positive optical power, and a first microstructure is provided on one side surface of the first metalens, wherein the distribution of the first microstructure satisfies the following formula: ； Among them, C 1i represents the binary surface coefficient of the first superlens, normR1 represents the normalized radius of the first superlens, R1 represents the radial position of the first superlens, The focal length of the depth perception lens is f, the entrance pupil diameter of the depth perception lens is EPD, and the total length of the depth perception lens is TTL, which satisfies the following relationship: 1.53 <f / EPD<1.60, 2.33 <TTL / EPD<3.20; The total length of the depth sensing lens is TTL, and the following conditions are met: 2.05 <TTL<2.958。 2. The depth perception lens according to claim 1, wherein: The maximum imaging height of the depth perception lens is ImgH, which satisfies the following relationship: 1.76<TTL / ImgH<2.

24.

3. The depth perception lens according to claim 2, wherein the maximum imaging height of the depth perception lens is ImgH, the focal length of the optical system of the depth perception lens is f, and the following relationship is satisfied: 0.82 <ImgH / f<0.92。 4. The depth perception lens according to claim 3, wherein: The distance between the image-side surface of the optical element closest to the image plane in the optical system of the depth perception lens and the imaging plane on the optical axis is BFL, and the entrance pupil diameter of the depth perception lens is EPD, which satisfies the following relationship: 0.65 <BFL / EPD<1.49。 5. The depth perception lens according to claim 4, wherein: The operating wavelength band of the depth perception lens is the near-infrared band of 940±10nm.

6. The depth perception lens according to claim 5, wherein: The first microstructure of the first superlens is a nanostructure extending on a plane perpendicular to the optical axis, and the shape of the nanostructure is a symmetrical structure of a cylinder, a ring or a square.

7. The depth perception lens according to claim 6, wherein: The phase transformation of the incident light by the first microstructure of the first superlens covers the range of 0-2pi.

8. The depth perception lens according to claim 7, wherein: The first microstructure is a nanostructure in which the relative phase of the incident light remains stable within a direction angle of 0-40 degrees and an azimuth angle of 0-180 degrees and the transmittance is greater than 0.

98.

9. The depth perception lens according to claim 8, wherein: The depth perception lens further includes a second super lens, and a second microstructure is provided on one side surface of the second super lens. The distribution of the second microstructure satisfies the following formula: ； Among them, C 2i represents the binary surface coefficient of the second metalens, normR2 represents the normalized radius of the second metalens, R2 represents the radial position of the second metalens, the second microstructure of the second metalens is a nanostructure extending on a plane perpendicular to the optical axis, and the shape of the nanostructure is a symmetrical structure of a cylinder, a ring or a square, and the phase transformation of the incident light by the second microstructure of the second metalens covers the range of 0-2pi, and the second microstructure is a nanostructure in which the relative phase of the incident light remains stable within the direction angle of 0-40 degrees and the azimuth angle of 0-180 degrees and the transmittance is greater than 0.

98.

10. The depth perception lens according to claim 9, wherein: The depth perception lens includes an aperture stop, a first metalens, a second metalens, and a color filter in sequence from the object side to the image side along the optical path, wherein a first microstructure is provided on the image side of the first metalens, a second microstructure is provided on the image side of the second metalens, and the second metalens also has positive optical power.

11. A depth perception lens module array, characterized in that: include: A transmitting module: the transmitting module is used to transmit laser signals to the outside world; A receiving module: The receiving module is used to receive the returned laser signal. The receiving module includes the depth perception lens according to any one of claims 1 to 10. The total length of the depth perception lens is TTL, and the total length of the transmitting module is TTLF. The receiving module satisfies the following conditions: 0.95<TTL / TTLF<1.05, the total length of the depth perception lens is smaller than the total length of the transmitting module.

Images