Depth sensing lens and depth sensing lens module array

Abstract

The invention provides a depth sensing lens, which is characterized in that the depth sensing lens sequentially comprises at least one optical element from an object side to an image side along an optical path, the at least one optical element is arranged along an optical axis of the depth sensing lens, and the at least one optical element comprises a first super lens, a first micro structure is arranged on the surface of one side of the first super lens, the focal length of the depth sensing lens is f, the entrance pupil diameter of the depth sensing lens is EPD, the total mechanism length of the depth sensing lens is TTL, and the following relational expressions are met: 1.53 lt; f / EPDlt; 1.60, 2.33 lt, 1.60, 2.33 lt; tTL / EPDlt; and 3.20, within the range, the depth sensing lens can enlarge the aperture and shorten the total length of the mechanism of the optical system at the same time, so that the depth sensing lens can be conveniently integrated on each terminal with 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 perception modules can provide spatial perception capabilities and are widely used in the fields of smartphones and head-mounted display technology (AR, VR or MR). In recent years, smartphones and head-mounted display technology have developed rapidly, and lightweight and compact structures are the future development trend.

[0003] In the existing technology, there is a solution that uses TOF (Time of Flight) technology for depth perception. The working principle of TOF technology is that the transmitting end emits laser, the receiving end receives laser, and the calculator establishes depth data related to the object based on the time difference from emission to reception, thereby constructing a three-dimensional image. Generally, the depth perception lens on the receiving end is specifically used for 3D recognition. In the industry, the depth perception module is also developing towards miniaturization and lightweight.

[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, which uses the light deflection effect to converge the laser signal at 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 a greater convergence capability and is difficult to have a lower height at the same time.

[0005] As the mainstream technology in the field of 3D perception, TOF technology has the advantages of long distance, high precision and anti-interference, and is the first choice for face recognition, gesture recognition, etc. The principles of wearing comfort and use comfort followed by consumer electronics, especially AR / VR, have put forward the requirements of extreme "lightness" and "thinness" for the volume and weight of the optical system.

[0006] Current TOF lenses generally adopt 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 a 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 a combination of aspherical lenses and spherical lenses is used, the manufacturing cost will be greatly increased; it is difficult for existing depth perception lenses to meet the standards of both a large aperture and controllable aberrations under the conditions of being thin, light, 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 metalens. A first microstructure is provided on one surface of the first metalens. 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, thus 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, thus 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. Description of the Drawings

[0010] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used 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 accompanying drawings, the same reference numerals generally represent the same components or steps.

[0011] Figure 1 A structural diagram of an optical system according to an embodiment of the present application is shown.

[0012] Figure 2 A schematic structural diagram of a metalens according to an embodiment of the present application is shown.

[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 A structural diagram of an optical system according to 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 optical system structure diagram of another embodiment of the present application is shown.

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

[0018] Figure 8 The optical system structure diagram of another embodiment of the present application is shown.

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

[0020] Fig.10 The optical system structure diagram of another embodiment of the present application is shown.

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

[0022] Fig.12 The optical system structure diagram of another embodiment of the present application is shown.

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

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

[0025] Fig.15 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 here.

[0027] In the description of the present invention, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, 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 the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0029] The terms "including" 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 comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0030] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, a contact connection, or an indirect connection through an intermediate medium, and it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Attached Figure 1Illustrates an implementation of a depth perception lens of the present application, where the depth perception lens 1 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 1, and the at least one optical element includes a first metalens 10, and a microstructure is provided on one side surface of the first metalens 10, and the distribution of the microstructure satisfies the following formula:

[0032]

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

[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, which satisfies the following relational expression: 1.53 < f / EPD < 1.60, such that the optical system of the depth perception lens 1 has a relatively large aperture number, which is beneficial to increasing the light input amount, 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 depth perception lens 1 to be integrated into various terminals in a smaller size.

[0035] In the present application, the first metalens 10 includes a first substrate 101 and a first microstructure 102; wherein, the first microstructure 102 is provided on one side of the first substrate 101, and the first substrate 101 can be made of glass or amorphous silicon material (amorphous silicon, a-Si), and semiconductor-level processes can be used to achieve mass transfer manufacturing. 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 an array of nanocolumns with different diameters, so as to achieve diffraction of incident light in the gaps with a size of several hundred nanometers between the nanocolumns, thereby realizing phase modulation of the incident light.

[0036] The microstructure in the present application can also adopt shapes such as cylinders, rings, and squares. Since such shapes are easy to process, they can be replicated in batches. The first microstructure 102 in the present application can be an array of regularly arranged nanostructures. The nanostructures are preferably square, and the nanostructures can be regular hexagons. A nanocylinder can be provided at the center of each square or regular hexagon nanostructure. 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, so as to achieve the effect of reducing the optical height by placing the stop 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 composed of a plurality of nanostructures arranged rotationally symmetrically. 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 may be in size or in 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 should know that for a superlens, a superlens is a two-dimensional plane lens composed of a supersurface structure; while a refractive lens is a three-dimensional lens made of a transparent material, and its structure includes two spherical surfaces or a spherical surface and a plane. A superlens uses a supersurface with a sub-wavelength thickness to focus light, thereby achieving optical transformation; a refractive lens achieves focusing or imaging by changing the propagation path of light according to the law of refraction of light. Those skilled in the art should know that the same unit structure has different responses to light fields at different incident angles, and a superlens is designed based on the response of a micro-nano structure unit to a light field, which is called "angle response". The inconsistency of the angle response will cause the actual phase of the superlens to deviate from the designed target phase when the incidence is not vertical, thereby introducing additional wave aberrations. The size of the wave aberration will directly affect the performance of the optical system, including resolution, depth of focus, contrast, and so on. This problem mainly occurs in the design and manufacturing process of the superlens. Designers need to accurately predict and adjust the angle response of each micro-nano structure unit to ensure the performance of the overall superlens in the actual use environment. At the same time, the manufacturing process also needs to be precise enough to ensure that the actual shape and size of each micro-nano structure unit are consistent with the design value. In the present application, in order to overcome the problem of "angle response", the first microstructure 102 of the first metalens 10 in the present application is selected to have a unit structure in which the relative phase remains stable and the transmittance is above 0.98 within the direction angle of 0-40 degrees and the azimuth angle of 0-180 degrees, thereby ensuring that the performance of the optical system, such as resolution, depth of focus, contrast, etc., is relatively excellent.

[0040] Attached 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, so that it has 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, so that the light can be fully transmitted through the first superlens 10, and the first superlens 10 can further modulate the light to achieve the phase adjustment effect on the light.

[0042] Those skilled in the art should know that the superlens in the present application uses a gradual and continuous surface to change the direction of the light beam. The substrate of the superlens in the present application is flat, and the period of the microstructure arranged on the substrate is very small. Therefore, the surface discreteness of the superlens is very high, and the superlens 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 the present 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 the present 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 the present application, thereby increasing the aperture of the superlens and achieving a large aperture effect.

[0044] The transmittance of the metalens designed in the present 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 Figure 3 As shown, the metalens in this application responds to the light field based on the microstructure. The inventors found that the same unit structure responds differently to light fields at different incident angles, resulting in the actual phase of the metalens deviating from the designed target phase when the incidence is not vertical, which will introduce additional wave aberrations, thereby causing the performance of the optical system to deteriorate. In order to solve this problem, this application improves the selection and testing method of the metalens unit structure, and adds additional scanning of the azimuth and direction angles on the basis of scanning the unit structure size.

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

[0047] Attached Figure 3 The second picture from the left is the prior art. Before the improvement of the selection method of different microstructures, the actual phase of the metalens deviates 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 in the microstructures of the present 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 specific direction angles. The microstructure of the present application satisfies the conditions that the phase uniformity and amplitude transmittance are as close to 1 as possible within a specific range, i.e., a direction angle of 0-40 degrees and an azimuth angle of 0-180 degrees.

[0049] In the present application, at least one group of 8-9 unit structures of microstructures is selected to meet the 0-2Pi phase coverage. Within the incident angle range expressed within a specific range, the phase of the 8-9 unit structures maintains the target phase, and the amplitude transmittance is close to 1. Figure 3 In the bottom diagram, the angle θ and 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 and emitter, and the laser wavelength is 940nm. The depth perception lens 1 can receive the light with a wavelength of 940nm reflected from the object. When sensing the depth, the calculator establishes the depth data of the object according to the time difference from emission to reception. The microstructure designed in this application can make the phase change of the light in the working band cover the interval of 0-2Pi, which can increase the effect of precision recognition. Figure 2 A structural design method of the present application is illustrated, which mainly designs a basic number and arrangement of unit columns according to the selected working band light (940nm light in the present application). 8-9 unit columns can be selected in the present application. When the incident angle of these 8-9 unit columns changes from 0 to 40 degrees, the phase 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 that the size of the depth perception lens 1 can be reduced, and further enables the depth perception lens 1 to be integrated into various terminals with a smaller size.

[0052] More specifically, the operating 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 between transmission and 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, particularly light with a wavelength of 940nm ± 10nm. A first microstructure 102 with a special shape and arranged in an array pattern is provided on one surface of the substrate. The first microstructure 101 can be square or hexagonal. A micro-nano structure is provided at the center of each square or hexagonal microstructure unit. According to the requirements of different embodiments, the first microstructure 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 microstructure 102 in the height direction can be circular, square, hollow ring, hollow square, cross-shaped, etc. According to different requirements, the microstructure 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 of view angle of the optical system, thereby increasing the range of the image obtained by the depth perception lens 1, further expanding the shooting range of the depth perception lens 1, and thus enabling the optical system to...

[0061] The distance from the image-side surface of the lens / superlens closest to the image plane to the imaging plane on the optical axis in the optical system 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] Refer to the attached... Figure 6 As shown, in some other embodiments, the depth perception lens 1 further includes a second superlens 20. The second superlens 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. The second microstructure 202 also satisfies the condition that the phase uniformity and the 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 superlens 20 is a nanostructure extending on a plane perpendicular to the optical axis. The basic shape of the nanostructure is a symmetric structure such as a cylinder, a ring, or a square. The phase transformation of the first microstructure 102 of the first superlens 10 covers the interval of 0 - 2pi for the incident light. The second microstructure 202 is a nanostructure with a relative phase remaining 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 remaining 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 superlens 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] Among them, C2i represents the binary surface coefficient of the second superlens, normR2 represents the normalized radius of the second superlens, R2 represents the radial position of the second superlens, the second microstructure of the second superlens 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 first microstructure of the first superlens covers the interval of 0-2pi for the phase change of the incident light, 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 for the incident light and the transmittance is greater than 0.98, and 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 for 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 super lens 10, a second super lens 20 and a color filter 40 in sequence from the object side to the image side along the optical path, wherein the first microstructure 102 is disposed on the image side of the first super lens 10, and the second microstructure 202 is disposed on the image side of the second super lens 20.

[0068] Table 1 below gives the numerical ranges of various conditional formulas of the present 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] Attached Figure 4 The 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 sequence from the object side to the image side along the optical path, wherein 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, and the structure is simple, so it is easy to assemble. 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 more than 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, which is 12.5lp / mm. The peak value of 0.8 means that the peak value of MTF is greater than 0.8, F1 represents the central 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, the optical performance is still maintained at a high level, which can provide consumers with a better user experience on a small-size lens.

[0075] In this embodiment, the TTL of the depth sensing lens 1 is 2.2 mm, and the total optical length is small, so it is easy to be miniaturized. The following Table 1 shows the parameters of Embodiment 1:

[0076]

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

[0078] Table 2 Super Lens 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] Attached Figure 6 The second embodiment of the depth perception lens of the present application is illustrated. In this embodiment, the depth perception lens 1 includes an aperture stop 50, a first super lens 10, a second super lens 20 and a color filter 40 in sequence from the object side to the image side along the optical path, wherein the image side of the first super lens 10 is provided with a first microstructure 102, and the image side of the second super lens 20 is provided with a second microstructure 202. In this embodiment, the combination of the first super lens 10 and the second super lens 20 can share the optical focal length required by each super lens, thereby reducing optical distortion. On the other hand, in this embodiment, the first super lens 10 and the second super lens 20 can be used to achieve optical imaging, and a smaller total optical length can be ensured. The first super lens 10 has a positive optical focal length to achieve light convergence imaging, and the second super lens 20 also has a positive optical focal length, so that the light can be further converged to achieve imaging.

[0081] In this embodiment, the illumination of the depth perception lens 1 can reach more than 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, which is 12.5lp / mm. The peak value of 0.8 means that the peak value of MTF is greater than 0.8, F1 represents the central 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, the optical performance is still maintained at a high level, which can provide consumers with a better user experience on a small-size lens.

[0082] In this embodiment, the TTL of the depth sensing lens 1 is 2.958 mm, and the total optical length is small, so it is easy to miniaturize. The following Table 3 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 as shown in Table 4:

[0085]

[0086]

[0087] <Example 3>

[0088] Attached Figure 8 The third embodiment of the depth perception lens of the present application is illustrated. In this embodiment, the depth perception lens 1 includes an aperture stop 50, a first metalens 10, a second metalens 20 and a color filter 40 in sequence from the object side to the image side along the optical path, wherein 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 focal length required by each metalens, thereby reducing optical distortion. On the other hand, in this embodiment, the first metalens 10 and the second metalens 20 can be used to achieve optical imaging, which can ensure a smaller total optical length.

[0089] The first super lens 10 has a positive optical focal length to achieve light convergence and imaging, and the second super lens 20 also has a positive optical focal length, so as to further converge 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 ≥ 60%, thereby achieving MTF greater than 0.95 and 0.8 at 12.5lp / mm and 25lp / mm in the F9 field of view, respectively, thereby 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 small, so it is easy to be miniaturized. 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] Attached Fig.10 The fourth 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, a first lens 30 and a color filter 40 in sequence from the object side to the image side along the optical path, wherein a first microstructure 102 is provided on the object side of the first metalens 10. In this embodiment, the first metalens 10 is used to assist in optical imaging, so that a smaller total optical length can be achieved.

[0097] In this embodiment, the aperture stop 50 is arranged 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 positive optical power to achieve light convergence and imaging, and the first lens 30 also has 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 a concave surface, and the first lens image side surface 302 is a convex surface, thereby improving the resolution of the depth perception lens 1 .

[0100] 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 ≥50%.

[0101] In this embodiment, a first microstructure 102 is provided on the object side of the first metalens 10, which ensures that the first metalens 10 has a smaller effective aperture. In this embodiment, the effective diameter of the first microstructure 102 on the object side 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 can be kept small, thereby reducing the manufacturing cost of the first metalens 10. Thus, the MTF of the F9 field of view at 12.5lp / mm and 25lp / mm is 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 small, so it is easy to miniaturize. The following Table 7 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 Super Lens 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] Attached Fig.12 The fifth embodiment of the depth perception lens 1 of the present application is illustrated. In this embodiment, the depth perception lens 1 includes an aperture stop 50, a first lens 30, a first metalens 10, a second lens 60 and a color filter 40 in order from the object side to the image side along the optical path, wherein a first microstructure 102 is provided on the object side of the first metalens 10. In this embodiment, the first metalens 10 is used to assist in optical imaging, which can achieve a shorter total optical length. In this embodiment, the aperture stop 50 is arranged in front of the entire optical system, which is conducive to reducing the total 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 a convex surface, and the first lens image side surface 302 is a concave surface, 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 a concave surface, and the second lens image side surface 602 is a convex surface, 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, so as to reduce spherical aberration, coma and other defects.

[0113] 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 that it can 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, compared with the solution of Embodiment 4, the effective focal length of the depth perception lens 1 can be increased while keeping the total optical length of the depth perception lens 1 substantially unchanged. On the other hand, by providing two lenses with a positive focal power and a negative focal power, 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 of the first superlens 10, which ensures that the first superlens 10 has a smaller effective aperture. In this embodiment, the effective diameter of the first microstructure 102 on the object side of the first superlens 10 is only 1.13 mm. Since the first microstructure 102 has a positive optical focal length, the size of the first superlens 10 can be ensured to be smaller, thereby reducing the manufacturing cost of the first superlens 10.

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

[0117]

[0118]

[0119] The phase information of the first superlens 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] Attached Fig.14 The sixth 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 lens 30, a first super lens 10, and a second lens 60 in sequence from the object side to the image side along the optical path, wherein a first microstructure 102 is provided on the object side of the first super lens 10. In this embodiment, the first super lens 10 is used to assist in optical imaging, so as to achieve a smaller total optical length.

[0125] In this embodiment, the aperture stop 50 is arranged 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 a convex surface, and the first lens image side surface 302 is a concave surface, 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 a concave surface, and the second lens image side surface 602 is a convex surface, 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, so as to reduce spherical aberration, coma and other defects.

[0129] 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 that it can 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 perception lens 1 can be increased while keeping the total optical length of the depth perception lens 1 substantially unchanged. On the other hand, by providing two lenses with positive and negative focal powers, the field of view of the depth perception lens 1 can be increased.

[0131] In this embodiment, a color filter film 70 is also provided on the image side of the first super lens 10. The color filter film 70 is an infrared cut-off film to filter infrared light, thereby ensuring that the captured image can be close to the perception of the human eye. In this embodiment, compared with the solution of providing a color filter 40 in other embodiments, the color filter film 70 is provided on the image side of the first super lens 10 in this embodiment, which can reduce the color filter 40 structure in the optical system, thereby achieving the role of the first super lens 10 replacing the color filter 40, and further reducing the total optical length of the depth perception lens 1 in this embodiment, and can achieve a size advantage of the total optical length within 2.05 mm.

[0132] Attached Fig.15The diagram shows the situation in which the transmitting module 1001 and the receiving module 1002 in the present application are mounted in a terminal such as a mobile phone. For the sake of the beauty 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 neater visual perception. 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 mounted in a terminal such as a mobile phone. For the sake of the beauty 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 neater 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 2.5 mm, and the sizes of the two are relatively close, which can ensure that when the depth perception lens module array 100 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.

[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 carry out miniaturization design.

[0135] Attached Fig.15 A depth sensing lens module array 100 is illustrated, the depth sensing lens module array 100 includes a transmitting module 1001, the transmitting module 1001 is used to transmit a laser signal to the outside, a receiving module 1002, the receiving module 1002 is used to receive a returned laser signal, the receiving module 1002 includes any one of the depth sensing lenses 1 mentioned above in the present application, the total length of the receiving module 1002 is TTLJ, 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, which can improve the beauty of the depth perception lens module array and at the same time improve the accuracy of depth perception.

[0138] The present 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 means that the intersection point 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 the optical system on the object 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, illumination refers to the density of light intensity in a specified direction. In the optical performance diagram of illumination, the horizontal axis represents the size of the field of view, and the vertical axis represents the illumination ratio.

[0142] The present application provides the following optical performance diagrams of the various embodiments. On the whole, the various embodiments of the present 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 1 is a diagram of field curvature, distortion and illumination of Example 1.

[0144] Figure 7 These are the field curvature, distortion and illumination diagrams of Example 2.

[0145] Fig. 9 These are the field curvature, distortion and illumination diagrams of Example 3.

[0146] Fig.11 These are the field curvature, distortion and illumination diagrams of Example 4.

[0147] Fig.13 These are the field curvature, distortion and illumination diagrams of Example 5.

[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 above embodiments. The above embodiments and the specification only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached 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, and 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 super lens, and a first microstructure is disposed on one side surface of the first super lens, wherein the distribution of the first microstructure satisfies the following formula: Wherein, C1i 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 sensing lens is f, the entrance pupil diameter of the depth sensing lens is EPD, and the total length of the depth sensing lens is TTL, which satisfies the following relationship: 1.53 <f / EPD<1.60, 2.33 <TTL / EPD<3.20。 2. The depth sensing lens according to claim 1, wherein: The total length of the depth sensing lens is TTL, and satisfies the following conditions: 2.05 <TTL<2.958。 3. The depth sensing lens according to claim 2, wherein: The maximum imaging height of the depth perception lens is ImgH, which satisfies the following relationship: 1.76<TTL / ImgH<2.

24.

4. The depth perception lens according to claim 3, 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。 5. The depth sensing lens according to claim 4, characterized in that: The distance between the image side surface of the optical element closest to the image plane in the optical system of the depth sensing lens and the imaging plane on the optical axis is BFL, and the entrance pupil diameter of the depth sensing lens is EPD, which satisfies the following relationship: 0.65 <BFL / EPD<1.49。 6. The depth sensing lens according to claim 5, characterized in that: The operating band of the depth perception lens is the near-infrared band of 940±10nm.

7. The depth sensing lens according to claim 6, characterized in that: The aperture value of the depth perception lens is Fno, which satisfies the following relationship: Fno≤1.

6.

8. The depth sensing lens according to claim 7, wherein: The first microstructure of the first superlens 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.

9. The depth sensing lens according to claim 8, characterized in that: The phase transformation of the incident light by the first microstructure of the first superlens covers the interval of 0-2pi.

10. The depth sensing lens according to claim 9, characterized in that: The first microstructure is a nanostructure whose relative phase remains stable within a direction angle of 0-40 degrees and an azimuth angle of 0-180 degrees for incident light and whose transmittance is greater than 0.

98.

11. The depth sensing lens according to claim 10, wherein: The depth perception lens further includes a second super lens, and a second microstructure is disposed on a surface of one side of the second super lens, and the distribution of the second microstructure satisfies the following formula: Among them, C2i represents the binary surface coefficient of the second superlens, normR2 represents the normalized radius of the second superlens, R2 represents the radial position of the second superlens, the second microstructure of the second superlens 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, and the phase transformation of the second microstructure of the second superlens to the incident light covers the interval of 0-2pi, and the second 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.

12. The depth sensing lens according to claim 11, characterized in that: The depth perception lens includes an aperture stop, the first super lens, the second super lens and a color filter in sequence from the object side to the image side along the optical path, wherein a first microstructure is arranged on the image side of the first super lens, a second microstructure is arranged on the image side of the second super lens, the first super lens has a positive optical power, and the second super lens also has a positive optical power.

13. A depth sensing 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 comprises the depth perception lens according to any one of claims 1 to 12, the total length of the depth perception lens is TTL, the total length of the transmitting module is TTLF, and the following conditions are met: 0.95<TTL / TTLF<1.05, the total length of the depth sensing lens is smaller than the total length of the transmitting module.

Images