TOF receiving optical system and TOF receiving optical lens
By designing a reasonable TOF receiving optical system structure, including multiple aspherical lenses and superlenses, the problem of excessive volume of the existing TOF receiving optical system is solved, and a miniaturized TOF receiving optical system is realized, which is suitable for smaller electronic devices.
Patent Information
- Application Number
- CN202421878223.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-05
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2034-08-05
AI Technical Summary
The existing TOF receiving optical systems are large in size and are difficult to install in smaller electronic devices without affecting the imaging quality.
A TOF receiving optical system is designed, including a first aspherical lens, an ultralens, a second aspherical lens, a third aspherical lens and a fourth aspherical lens along the optical axis. Through reasonable power distribution and lens structure, the total optical length is shortened to reduce the volume.
The volume of the TOF receiving optical system is significantly compressed without sacrificing imaging quality, making it suitable for smaller electronic devices, and expanding the scope of application.
Smart Images
Figure CN222825733U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical systems, and in particular to a TOF receiving optical system and a TOF receiving optical lens. Background Art
[0002] TOF modules are widely used in virtual reality, face recognition, smart home, autonomous driving, machine vision and other fields. As electronic devices are generally developing towards miniaturization, the installation space left for TOF modules in electronic devices equipped with TOF modules is usually small, which means that TOF modules need to be compressed to a certain extent without sacrificing imaging quality in order to expand their scope of application.
[0003] Since the size of the TOF receiving optical system in the prior art is usually relatively large, the TOF receiving optical system may not be installed in an electronic device with a relatively small size. Utility Model Content
[0004] In response to the above technical problems, the embodiments of the present application provide a TOF receiving optical system and a TOF receiving optical lens, aiming to provide a TOF receiving optical system and a TOF receiving optical lens with good imaging quality and small size.
[0005] According to one aspect of an embodiment of the present application, a TOF receiving optical system is disclosed, and the TOF receiving optical system includes, in order from the object side to the image side along the optical axis: a first aspheric lens, a super lens, a second aspheric lens, a third aspheric lens and a fourth aspheric lens; the optical power of the first aspheric lens is positive, the object side surface of the first aspheric lens is convex to the object side, and the image side surface of the first aspheric lens is convex to the object side; the optical power of the super lens is positive; the optical power of the second aspheric lens is negative, the object side surface of the second aspheric lens is convex to the image side, and the image side surface of the second aspheric lens is convex to the image side; the optical power of the third aspheric lens is positive, and the object side surface of the third aspheric lens is convex to the image side; the optical power of the fourth aspheric lens is negative;
[0006] The TOF receiving optical system meets the following requirements: Among them, the f m is the focal length of the superlens, and f is the effective focal length of the TOF receiving optical system.
[0007] In some embodiments, the TOF receiving optical system satisfies: Wherein, Δλ is the difference between the maximum wavelength and the minimum wavelength of the working band of the TOF receiving optical system, is the phase of the superlens, and x is the distance between the point on the superlens and the center of the superlens.
[0008] In some embodiments, the TOF receiving optical system satisfies: Wherein, n1 is the refractive index of the first aspheric lens, EPD is the entrance pupil diameter of the TOF receiving optical system, and R F1 is the radius of curvature of the object side of the first aspheric lens, and the K F1 is the cone coefficient of the object side surface of the first aspheric lens.
[0009] In some embodiments, the TOF receiving optical system satisfies: Among them, the R L1 is the radius of curvature of the object side of the fourth aspheric lens, and the R L2 is the curvature radius of the image side surface of the fourth aspheric lens, and the K L1 is the cone coefficient of the object side of the fourth aspheric lens, and the K L2 is the cone coefficient of the image-side surface of the fourth aspheric lens.
[0010] In some embodiments, the TOF receiving optical system satisfies: Among them, the TTL is the total optical length of the TOF receiving optical system, the CT1 is the center thickness of the first aspheric lens, the CT3 is the center thickness of the second aspheric lens, the CT4 is the center thickness of the third aspheric lens, and the CT5 is the center thickness of the fourth aspheric lens.
[0011] In some embodiments, the TOF receiving optical system satisfies: Among them, the R L1 is the radius of curvature of the object side of the fourth aspheric lens, and the R L2 is the curvature radius of the image side surface of the fourth aspheric lens, n4 is the refractive index of the fourth aspheric lens, and CT5 is the center thickness of the fourth aspheric lens.
[0012] In some embodiments, the TOF receiving optical system satisfies: Wherein, the EPD is the entrance pupil diameter of the TOF receiving optical system, and f is the effective focal length of the TOF receiving optical system.
[0013] In some embodiments, the TOF receiving optical system satisfies: i >1.6; vd i <25, where n iis the minimum value of the refractive index of the first aspheric lens, the second aspheric lens, and the fourth aspheric lens, vd i is the maximum value of the Abbe numbers of the first aspheric lens, the second aspheric lens, and the fourth aspheric lens.
[0014] In some embodiments, the TOF receiving optical system further includes an aperture, and the aperture is disposed on the object side of the first aspheric lens; or, the aperture is disposed between any two adjacent lenses.
[0015] A second aspect of an embodiment of the present application provides a TOF receiving optical lens, wherein the TOF receiving optical lens comprises: an imaging detector and a TOF receiving optical system as described in any one of the above items.
[0016] The TOF receiving optical system provided by the present application includes, from the object side to the image side along the optical axis, a first aspheric lens, a super lens, a second aspheric lens, a third aspheric lens and a fourth aspheric lens in sequence; the optical power of the first aspheric lens is positive, the object side surface of the first aspheric lens is convex to the object side, and the image side surface of the first aspheric lens is convex to the object side; the optical power of the super lens is positive; the optical power of the second aspheric lens is negative, the object side surface of the second aspheric lens is convex to the image side, and the image side surface of the second aspheric lens is convex to the image side; the optical power of the third aspheric lens is positive, and the object side surface of the third aspheric lens is convex to the image side; the optical power of the fourth aspheric lens is negative. The TOF receiving optical system satisfies: Among them, f m is the focal length of the metalens, and f is the effective focal length of the TOF receiving optical system. The TOF receiving optical system provided in the present application has a short total optical length. Therefore, the TOF receiving optical system is small in size and can be applied to various small electronic devices, with a large application range. The TOF receiving optical system has good processability while having better imaging quality through reasonable optical focal length distribution, which can be convenient for mass production. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and other objects, features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.
[0018] Figure 1 A schematic diagram of the architecture layout of a TOF receiving optical system in one embodiment of the present application is shown.
[0019] Figure 2 A chromatic aberration diagram of a TOF receiving optical system in one embodiment of the present application is shown.
[0020] Figure 3 A distortion diagram of the TOF receiving optical system in one embodiment of the present application is shown.
[0021] Figure 4 A vertical axis chromatic aberration diagram of a TOF receiving optical system in one embodiment of the present application is shown.
[0022] Figure 5 A schematic diagram of the architecture layout of a TOF receiving optical system in one embodiment of the present application is shown.
[0023] Figure 6 A chromatic aberration diagram of a TOF receiving optical system in one embodiment of the present application is shown.
[0024] Figure 7 A distortion diagram of the TOF receiving optical system in one embodiment of the present application is shown.
[0025] Figure 8 A vertical axis chromatic aberration diagram of a TOF receiving optical system in one embodiment of the present application is shown.
[0026] Fig. 9 A schematic diagram of the architecture layout of a TOF receiving optical system in one embodiment of the present application is shown.
[0027] Fig.10 A chromatic aberration diagram of a TOF receiving optical system in one embodiment of the present application is shown.
[0028] Fig.11 A distortion diagram of the TOF receiving optical system in one embodiment of the present application is shown.
[0029] Fig.12 A vertical axis chromatic aberration diagram of a TOF receiving optical system in one embodiment of the present application is shown.
[0030] Reference numerals
[0031] 100. TOF receiving optical system;
[0032] 10. A first aspheric lens;
[0033] 20. Super lens; 210. Substrate; 220. Micro-nano structure;
[0034] 30. A second aspheric lens;
[0035] 40. a third aspheric lens;
[0036] 50. a fourth aspheric lens;
[0037] 60. Aperture;
[0038] A, object plane; B, image plane; S, optical axis. DETAILED DESCRIPTION
[0039] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present application will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.
[0040] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present application. However, those skilled in the art will appreciate that the technical solution of the present application may be practiced while omitting one or more of the specific details, or other modules, components, etc. may be adopted. In other cases, known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring the present application and making the various aspects of the present application obscure.
[0041] See also Figure 1 , Figure 1 FIG. 1 shows a schematic diagram of the architecture layout of a TOF receiving optical system 100 in an embodiment of the present application, wherein the optical axis S is the center line of the light beam. Figure 1 In the figure, the object to be measured is located on the left side of the leftmost lens, that is, the object side is located on the left side of the leftmost lens, and the object plane A is located on the object side. The image formed by the TOF receiving optical system 100 is located on the right side of the rightmost lens, that is, the image side is located on the right side of the rightmost lens, and the image plane B is located on the image side. Therefore, the direction from the object plane A to the image plane B along the optical axis S is consistent with the direction from the object side to the image side along the optical axis S.
[0042] In the present application, the surface of each optical element closer to the object side of the two surfaces along the optical axis S direction is the object side of the optical element, and the surface of each optical element closer to the image side of the two surfaces along the optical axis S direction is the image side of the optical element. The side of each optical element closer to the object side along the optical axis S direction is the object side of the optical element, and the side of each optical element closer to the image side along the optical axis S direction is the image side of the optical element.
[0043] Please refer again Figure 1 The TOF receiving optical system 100 includes a first aspheric lens 10, a super lens 20, a second aspheric lens 30, a third aspheric lens 40 and a fourth aspheric lens 50. The first aspheric lens 10, the super lens 20, the second aspheric lens 30, the third aspheric lens 40 and the fourth aspheric lens 50 are arranged in sequence along the optical axis S from the object side to the image side.
[0044] The first aspheric lens 10 has a positive refractive power, an object-side surface of the first aspheric lens 10 is convex toward the object side, and an image-side surface of the first aspheric lens 10 is convex toward the object side.
[0045] The optical power of the superlens 20 is positive. The superlens 20 includes a substrate 210 and a micro-nano structure 220. The micro-nano structure 220 is a sub-wavelength structure, and the micro-nano structure 220 is arranged on the object side of the substrate 210 and / or the image side of the substrate 210. According to the phase modulation method adopted, the corresponding phase modulation formula can be adaptively used to configure various parameters of the micro-nano structure 220, so that the superlens 20 has the expected optical performance.
[0046] The refractive power of the second aspheric lens 30 is negative, the object side surface of the second aspheric lens 30 is convex toward the image side, and the image side surface of the second aspheric lens 30 is convex toward the image side.
[0047] The third aspherical lens 40 has positive refractive power, and the object side surface of the third aspherical lens 40 is convex toward the image side.
[0048] The fourth aspherical lens 50 has negative refractive power.
[0049] The TOF receiving optical system 100 satisfies conditional formula 1: Among them, f m is the focal length of the super lens 20, and f is the effective focal length of the TOF receiving optical system 100. m , f have the same dimension, both are length units, such as millimeters.
[0050] Conditional formula 1 reflects the ratio of the focal length of the metalens 20 to the effective focal length of the TOF receiving optical system 100. Conditional formula 1 shows that the optical focal length provided by the metalens 20 in the TOF receiving optical system 100 is much smaller than the optical focal length of the TOF receiving optical system 100. The main function of the metalens 20 is to provide spherical aberration correction in the edge field of view and aberration compensation in the full field of view to improve the imaging quality of the TOF receiving optical system 100. The upper limit of conditional formula 1 is used to ensure that the metalens 20 has the expected optical focal length to achieve the light adjustment within the system length, thereby ensuring that the metalens 20 has the ability to provide spherical aberration correction in the edge field of view and aberration compensation in the full field of view. The lower limit of conditional formula 1 can avoid the optical focal length provided by the metalens 20 being too large. If the optical focal length provided by the metalens 20 is too large, it will cause the compensation provided by the metalens 20 to be too large, which will introduce a large chromatic aberration, which is not conducive to improving the imaging quality of the TOF receiving optical system 100.
[0051] The TOF receiving optical system 100 provided by the present application has a short total optical length, so the TOF receiving optical system 100 is small in size and can be applied to various small electronic devices, having a wide range of applications. The TOF receiving optical system 100 has good processability while having good imaging quality through reasonable optical focal length distribution, and can be easily mass-produced.
[0052] In some embodiments, the micro-nano structure 220 is disposed on a surface of the substrate 210 close to the object side.
[0053] In some embodiments, the micro-nano structure 220 is disposed on the object-side surface of the substrate 210 .
[0054] In some embodiments, the micro-nano structure 220 is disposed on the lowered image-side surface.
[0055] In some embodiments, the object-side surface of the substrate 210 and the image-side surface of the substrate 210 are both provided with a micro-nano structure 220 , so that the metalens 20 has a higher degree of freedom in design.
[0056] In some embodiments, the micro-nano structure 220 is a positive micro-nano structure.
[0057] In some embodiments, the micro-nano structure 220 is a negative micro-nano structure.
[0058] In some embodiments, the micro-nano structure 220 is provided with a layer to make the processing technology of the superlens 20 compatible with the existing semiconductor processing technology, which can facilitate the processing and manufacturing of the superlens 20.
[0059] In some embodiments, the micro-nano structure 220 has two or more layers, so that the superlens 20 has a larger optical focal length that meets the expected requirements.
[0060] For the superlens 20, the position of the micro-nano structure 220, the positive and negative sides of the micro-nano structure 220, and the number of layers of the micro-nano structure 220 can be freely combined as long as the superlens 20 has the expected performance.
[0061] In some embodiments, the phase distribution of the metalens 20 satisfies the following formula:
[0062]
[0063] Wherein, r is the distance from the center of the superlens 20 to any micro-nanostructure 220, λ is the central wavelength of the working band of the superlens 20, is the phase constant, (x, y) is the two-dimensional coordinate of the surface of the metalens 20, a i 、b i 、a ij 、b ijare all real coefficients, N is the number of phase coefficients, f m is the focal length of the superlens 20.
[0064] Further, in some embodiments, the TOF receiving optical system 100 satisfies conditional formula 2: Among them, f m is the focal length of the super lens 20, and f is the effective focal length of the TOF receiving optical system 100. m , f have the same dimension, both are length units, such as millimeters.
[0065] Conditional expression 2 is used to more accurately control the optical focal length of the metalens 20 , so that the metalens 20 can provide spherical aberration correction in the edge field of view and aberration compensation in the full field of view in accordance with expectations, which is beneficial to improving the imaging quality of the TOF receiving optical system 100 .
[0066] In some embodiments, the TOF receiving optical system 100 satisfies conditional equation 3: Wherein, Δλ is the difference between the maximum wavelength and the minimum wavelength of the working band of the TOF receiving optical system 100. For example, assuming that the working band of the TOF receiving optical system 100 is a nanometer to b nanometer, and b is greater than a, then Δλ=(ba) nanometers. The unit of "2π" in conditional formula 4 is rad. is the phase of the superlens 20, The unit of is 2πrad. x is the distance between a point on the metalens 20 and the center of the metalens 20. The dimension of Δλ is the same as that of x, both of which are length units, such as millimeters.
[0067] is the change in the phase of the superlens 20, dx is the change in the distance between a point on the superlens 20 and the center of the superlens 20, is the phase gradient of the superlens 20, The unit is 2πrad / mm. represents the maximum value of the phase gradient of the metalens 20, and the magnitude of the phase gradient represents the magnitude of the negative chromatic aberration introduced by the metalens 20. The lower limit of conditional formula 4 can ensure that the metalens 20 has sufficient and expected refractive power, and the upper limit of conditional formula 4 can avoid the metalens 20 from introducing excessive chromatic aberration, thereby ensuring the imaging quality of the TOF receiving optical system 100.
[0068] In some embodiments, the TOF receiving optical system 100 satisfies conditional formula 4: Wherein, n1 is the refractive index of the first aspheric lens 10, EPD (Entrance Pupil Diameter, referred to as EPD) is the entrance pupil diameter of the TOF receiving optical system 100, R F1is the radius of curvature of the object side of the first aspheric lens 10, K F1 is the cone coefficient of the object side surface of the first aspherical lens 10. EPD, R F1 have the same dimension, which is a unit of length, such as millimeter.
[0069] The upper limit and lower limit of conditional expression 4 are used to ensure that the incident angle and the clear aperture of the TOF receiving optical system 100 are within the processing range.
[0070] In some embodiments, the TOF receiving optical system 100 satisfies Condition 5: Among them, R L1 is the radius of curvature of the object side surface of the fourth aspherical lens 50, R L2 is the curvature radius of the image side surface of the fourth aspherical lens 50, K L1 is the cone coefficient of the object side surface of the fourth aspherical lens 50, K L2 is the conic coefficient of the image side surface of the fourth aspherical lens 50. L1 , R L2 have the same dimension, which is a unit of length, such as millimeter.
[0071] Conditional formula 5 reflects the light-gathering ability and processability of the fourth aspheric lens 50. The lower limit of conditional formula 5 ensures that the difference in curvature radius between the object side and the image side of the fourth aspheric lens 50 is appropriate, making the fourth aspheric lens 50 easy to process, and at the same time helps to control the angle between the object side and the image side of the fourth aspheric lens 50 and the incident light so that it is not too large. The upper limit of conditional formula 5 can ensure that the fourth aspheric lens 50 has the expected light-gathering ability, helps to reduce the aberration of the TOF receiving optical system 100, and controls the size of the optical back focal length of the TOF receiving optical system 100.
[0072] In some embodiments, the TOF receiving optical system 100 satisfies conditional formula 6: Wherein, TTL (Total Track Length, TTL for short) is the total optical length of the TOF receiving optical system 100, CT1 is the center thickness of the first aspheric lens 10, and in the present application, the center thickness of each lens is the thickness of the corresponding lens on the optical axis S. CT3 is the center thickness of the second aspheric lens 30, CT4 is the center thickness of the third aspheric lens 40, and CT5 is the center thickness of the fourth aspheric lens 50. TTL, CT1, CT3, CT4, and CT5 have the same dimension, which is a length unit, such as millimeters.
[0073] The conditional formula six is used to limit the total optical length of the TOF receiving optical system 100, and the conditional formula six is also used to limit the ratio of the total optical length of the TOF receiving optical system 100 to the total thickness of the first aspheric lens 10, the second aspheric lens 30, the third aspheric lens 40, and the fourth aspheric lens 50. Since a thick lens helps to reduce the field curvature of the TOF receiving optical system 100, but a thick lens increases the total optical length, the upper limit of the conditional formula six is used to limit the total optical length of the TOF receiving optical system 100, so that the TOF receiving optical system 100 has a smaller volume, and the field curvature of the TOF receiving optical system 100 can also be controlled. The upper limit of the conditional formula six can avoid the thickness of the thick lens being too thick, and the thickness of the thick lens is not too thick to leave space for other lenses and air gaps, so that the chromatic aberration of the TOF receiving optical system 100 can be eliminated by matching the lens material and curvature.
[0074] In some embodiments, the TOF receiving optical system 100 satisfies conditional equation 7: Among them, R L1 is the radius of curvature of the object side surface of the fourth aspherical lens 50, R L2 R is the curvature radius of the image side surface of the fourth aspheric lens 50, n4 is the refractive index of the fourth aspheric lens 50, and CT5 is the center thickness of the fourth aspheric lens 50. L1 , R L2 , CT5 have the same dimension, both are length units, such as millimeters.
[0075] Conditional expression 7 constrains the focal length of the fourth aspherical lens 50 , which can ensure that the light can be converged onto the image plane B and can be adapted to the incident angle of the image detector adapted to the TOF receiving optical system 100 .
[0076] In some embodiments, the TOF receiving optical system 100 satisfies Conditional Formula 8: Wherein, EPD is the entrance pupil diameter of the TOF receiving optical system 100, and f is the effective focal length of the TOF receiving optical system 100. EPD and f have the same dimension, both of which are length units, such as millimeters. Conditional formula eight ensures that the TOF receiving optical system 100 achieves a balance between the amount of light entering and the imaging quality.
[0077] In some embodiments, the TOF receiving optical system 100 satisfies the conditional formula 9: i >1.6; vd i <25, where n i is the minimum value of the refractive index of the first aspheric lens 10, the second aspheric lens 30, and the fourth aspheric lens 50, that is, the refractive index of the first aspheric lens 10, the second aspheric lens 30, and the fourth aspheric lens 50 are all greater than 1.6. iis the maximum value of the Abbe numbers of the first aspheric lens 10 , the second aspheric lens 30 , and the fourth aspheric lens 50 , that is, the Abbe numbers of the first aspheric lens 10 , the second aspheric lens 30 , and the fourth aspheric lens 50 are all less than 25.
[0078] Conditional formula nine constrains the material distribution of the TOF receiving optical system 100, which can ensure that the first aspheric lens 10, the second aspheric lens 30, the third aspheric lens 40, and the fourth aspheric lens 50 all have sufficiently strong refractive power, thereby greatly shortening the total optical length of the TOF receiving optical system 100. The larger chromatic aberration caused by the first aspheric lens 10, the second aspheric lens 30, the third aspheric lens 40, and the fourth aspheric lens 50 can be compensated by the super lens 20.
[0079] The TOF receiving optical system 100 further includes an aperture 60 , which is used to control the amount of light entering the TOF receiving optical system 100 , thereby ensuring that the TOF receiving optical system 100 can work effectively and generate high-quality images.
[0080] In some embodiments, the aperture 60 is disposed on the object side of the first aspheric surface, specifically:
[0081] (1) The aperture 60 is located on the object side of the first aspheric lens 10, and the aperture 60 is spaced apart from the first aspheric lens 10;
[0082] (2) The aperture 60 is located on the object side surface of the first aspheric lens 10 , that is, the aperture 60 is disposed in contact with the object side surface of the first aspheric lens 10 .
[0083] In some embodiments, the aperture 60 is disposed between any two adjacent lenses, specifically:
[0084] (1) The aperture 60 is located between the first aspheric lens 10 and the super lens 20, and the aperture 60 is attached to the image side surface of the first aspheric lens 10;
[0085] (2) The aperture 60 is located between the first aspheric lens 10 and the super lens 20, and the aperture 60 is spaced apart from the first aspheric lens 10 and the super lens 20;
[0086] (3) The aperture 60 is located between the first aspheric lens 10 and the super lens 20, and the aperture 60 is arranged in contact with the object side surface of the super lens 20;
[0087] (4) The aperture 60 is located between the super lens 20 and the second aspheric lens 30, and the aperture 60 is arranged in contact with the image side surface of the super lens 20;
[0088] (5) The aperture 60 is located between the super lens 20 and the second aspheric lens 30, and the aperture 60 is spaced apart from the super lens 20 and the second aspheric lens 30;
[0089] (6) The aperture 60 is located between the metalens 20 and the second aspheric lens 30, and the aperture 60 is attached to the object side surface of the second aspheric lens 30;
[0090] (7) The aperture 60 is located between the second aspheric lens 30 and the third aspheric lens 40, and the aperture 60 is arranged in contact with the image side surface of the second aspheric lens 30;
[0091] (8) The aperture 60 is located between the second aspheric lens 30 and the third aspheric lens 40, and the aperture 60 is spaced apart from the second aspheric lens 30 and the third aspheric lens 40;
[0092] (9) The aperture 60 is located between the second aspheric lens 30 and the third aspheric lens 40, and the aperture 60 is attached to the object side surface of the third aspheric lens 40;
[0093] (10) The aperture 60 is located between the third aspheric lens 40 and the fourth aspheric lens 50, and the aperture 60 is arranged in contact with the image side surface of the third aspheric lens 40;
[0094] (11) The aperture 60 is located between the third aspheric lens 40 and the fourth aspheric lens 50, and the aperture 60 is spaced apart from the third aspheric lens 40 and the fourth aspheric lens 50;
[0095] (12) The aperture 60 is located between the third aspheric lens 40 and the fourth aspheric lens 50 , and the aperture 60 is disposed in contact with the object side surface of the fourth aspheric lens 50 .
[0096] In some embodiments, the TOF receiving optical system 100 further includes a filter (not shown), which is disposed at any position in the optical path and is used to filter light outside the working band to improve imaging quality.
[0097] In some embodiments, the filter is a coating (not shown), and the filter is disposed on the object side or image side of any lens. Since the coating is thin, when the filter is a coating, the total optical length of the TOF receiving optical system 100 can be further compressed.
[0098] The TOF receiving optical system 100 provided in this embodiment has the following benefits:
[0099] (1) The total optical length is less than 2.25 mm;
[0100] (2) F number less than 2.2;
[0101] (3) The MTF (Modulation Transfer Function, MTF for short) at the cutoff frequency of 100lp / mm with maximum field of view is greater than 0.35;
[0102] (4) Vertical axis chromatic aberration is less than 1um and distortion is less than 10%.
[0103] The present application exemplarily provides three TOF receiving optical systems 100 that meet usage requirements in three embodiments. Next, the TOF receiving optical systems 100 provided in the various embodiments of the present application are introduced in detail.
[0104] Example 1
[0105] Figure 1 The schematic diagram of the architecture layout of the TOF receiving optical system 100 provided in Example 1 is shown. The TOF receiving optical system 100 provided in Example 1 includes, from the object plane A to the image plane B along the optical axis S, an aperture 60, a first aspheric lens 10, a super lens 20, a second aspheric lens 30, a third aspheric lens 40 and a fourth aspheric lens 50 in sequence, wherein the micro-nano structure 220 is disposed on the object side of the substrate 210, the filter is a coating, and the filter is disposed on the object side of the super lens 20. Some parameters of the TOF receiving optical system 100 provided in Example 1 are shown in Table 1-1.
[0106] Table 1-1. Partial parameters of the TOF receiving optical system 100 provided in Example 1
[0107] parameter data Total optical length (TTL) 2.1mm Maximum field of view (2ω) 84° F-number 2.2 Effective focal length 2.05mm Working band Near infrared (920nm-960nm)
[0108] As can be seen from Table 1-1, the operating wavelength band of the TOF receiving optical system 100 is 920 nm to 960 nm. The total optical length of the TOF receiving optical system 100 is relatively short, only 2.1 mm, so the volume of the TOF receiving optical system 100 provided in Example 1 is relatively small.
[0109] Along the optical axis S from the object plane A to the image plane B, starting from the aperture 60, each surface in the TOF receiving optical system 100 is numbered, and the parameters of each surface are summarized to obtain the following Table 1-2.
[0110] Table 1-2. Parameters of various surfaces in the TOF receiving optical system 100 provided in Example 1
[0111] Surface serial number Surface type Curvature radius (mm) Thickness(mm) Refractive Index and Abbe Number of Materials 1 Aperture unlimited -0.15 - 2 Aspheric 0.76 0.3 1.64，23.5 3 Aspheric 1.67 0.1 - 4 Structural surface unlimited 0.2 1.46，67.8 5 Spherical unlimited 0.1 - 6 Aspheric -4.2 0.2 1.65，21.5 7 Aspheric -5.3 0.2 - 8 Aspheric -2.0 0.2 1.64，23.5 9 Aspheric -0.6 0.1 - 10 Aspheric -0.74 0.3 1.64，23.5 11 Aspheric 2.06 0.4 - 12 Image plane - - -
[0112] For each surface in Table 1-2, surface 1 is the aperture 60, surface 2 is the object side surface of the first aspheric lens 10, and surface 3 is the image side surface of the first aspheric lens 10. Surface 4 is the object side surface of the super lens 20. Since the micro-nano structure 220 is arranged on the object side surface of the substrate 210, surface 4 is recorded as the structural surface, and surface 5 is the image side surface of the super lens 20. Surface 6 is the object side surface of the second aspheric lens 30, and surface 7 is the image side surface of the second aspheric lens 30. Surface 8 is the object side surface of the third aspheric lens 40, and surface 9 is the image side surface of the third aspheric lens 40. Surface 10 is the object side surface of the fourth aspheric lens 50, and surface 11 is the image side surface of the fourth aspheric lens 50. Surface 12 is the image surface B.
[0113] As can be seen from Table 1-2, the radius of curvature of surface 1 is infinite, that is, surface 1 is a plane, and the distance between surface 1 and surface 2 is -0.15 mm, where the negative sign in "-0.15 mm" means that surface 2 is 0.15 mm protruding from the surface toward the object side, and the material between surface 1 and surface 2 is air. Surface 2 is an aspherical surface, the radius of curvature of surface 2 is 0.76 mm, the distance between surface 2 and surface 3 is 0.3 mm, and the refractive index and Abbe number of the material between surface 2 and surface 3 are 1.64 and 23.5 respectively. Surface 3 is an aspherical surface, the radius of curvature of surface 3 is 1.67 mm, the distance between surface 3 and surface 4 is 0.1 mm, and the material between surface 3 and surface 4 is air. The radius of curvature of surface 4 is infinite, that is, surface 4 is a plane, the distance between surface 4 and surface 5 is 0.2 mm, and the refractive index and Abbe number of the material between surface 4 and surface 5 are 1.46 and 67.8 respectively. Surface 5 is a spherical surface, and the radius of curvature of surface 5 is infinite, that is, surface 5 is a plane, the distance between surface 5 and surface 6 is 0.1 mm, and the material between surface 5 and surface 6 is air. Surface 6 is an aspherical surface, and the radius of curvature of surface 6 is -4.2 mm, the distance between surface 6 and surface 7 is 0.2 mm, and the refractive index and Abbe number of the material between surface 6 and surface 7 are 1.65 and 21.5 respectively. Surface 7 is an aspherical surface, and the radius of curvature of surface 7 is -5.3 mm, the distance between surface 7 and surface 8 is 0.2 mm, and the material between surface 7 and surface 8 is air. Surface 8 is an aspherical surface, and the radius of curvature of surface 8 is -2.0 mm, the distance between surface 8 and surface 9 is 0.2 mm, and the refractive index and Abbe number of the material between surface 8 and surface 9 are 1.64 and 23.5 respectively. Surface 9 is an aspherical surface, the radius of curvature of surface 9 is -0.6 mm, the distance between surface 9 and surface 10 is 0.1 mm, and the material between surface 9 and surface 10 is air. Surface 10 is an aspherical surface, the radius of curvature of surface 10 is -0.7 mm, the distance between surface 10 and surface 11 is 0.3 mm, and the refractive index and Abbe number of the material between surface 10 and surface 11 are 1.64 and 23.5 respectively. Surface 11 is an aspherical surface, the radius of curvature of surface 11 is 2.05, the distance between surface 11 and surface 12 is 0.4 mm, and the material between surface 11 and surface 12 is air.
[0114] Surface 2, surface 3, surface 6, surface 7, surface 8, surface 9, surface 10, and surface 11 are all even-order aspheric surfaces, and their surface shapes satisfy the following relationship:
[0115]
[0116] Among them, Z(r) is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of r along the optical axis SS; c is the curvature of the aspherical surface, c=1 / R, R is the radius of curvature of the aspherical surface; k is the cone coefficient; A, B, C, D... are the aspherical coefficients. The values of k, A, B, C, D... of surface 2, surface 3, surface 6, surface 7, surface 8, surface 9, surface 10, and surface 11 can all be obtained from Table 1-3.
[0117] Table 1-3. Coefficients of the even-order aspheric surfaces in the TOF receiving optical system 100 provided in Example 1
[0118] Surface serial number k A B C D E F G 2 9.5E-03 -6.7E-02 8.1E-01 -3.3E+00 -4.0E+01 2.3E+02 -4.9E+02 0.0E+00 3 -6.8E-01 3.1E-01 -8.2E+00 5.2E+01 -3.3E+02 4.1E+02 1.9E+03 0.0E+00 6 8.3E+01 -3.3E-01 -3.4E+00 4.3E+01 -3.2E+02 1.9E+03 -5.7E+03 0.0E+00 7 -4.3E+00 -5.1E-01 -1.3E+00 1.6E+01 -3.9E+01 5.7E+01 -5.8E+01 0.0E+00 8 7.1E+00 2.9E-01 2.0E-01 -2.0E+01 1.0E+02 -2.2E+02 1.9E+02 0.0E+00 9 -1.1E+00 2.6E+00 -4.3E+00 2.7E+00 1.0E+00 -2.5E+00 1.0E+00 0.0E+00 10 -6.3E+00 3.4E-01 -8.2E-01 1.1E+00 -7.5E-01 2.7E-01 -3.8E-02 0.0E+00 11 -5.9E+01 -1.9E-01 1.4E-01 -1.4E-01 9.6E-02 -4.8E-02 1.2E-02 0.0E+00
[0119] Please refer to Table 1-3. For surface 2, k is 9.5E-03, A is -6.7E-02, B is 8.1E-01, C is -3.3E+00, D is -4.0E+01, E is 2.3E+02, F is -4.9E+02, and G is 0.0E+00. The coefficients of the even-order aspheric surfaces of surface 3, surface 6, surface 7, surface 8, surface 9, surface 10, and surface 11 can be found in Table 1-3 with reference to surface 2, and will not be described one by one in this embodiment.
[0120] See also Figure 2 , Figure 2 : shows a field curvature diagram of the TOF receiving optical system 100 provided in Example 1, Figure 2 The horizontal axis is the field curvature, and its unit is millimeters. Figure 2 The vertical axis is the Y-axis field of view, and its unit is degree. Figure 2 The field curvatures of 920 nm, 940 nm, and 960 nm light in the meridional and sagittal directions are shown in the figure. Since the field curvature curves of 920 nm, 940 nm, and 960 nm light in the meridional direction are relatively concentrated, the field curvature curves of 920 nm, 940 nm, and 960 nm light in the meridional direction are not distinguished and are uniformly labeled as T curves; the field curvature curves of 920 nm, 940 nm, and 960 nm light in the sagittal direction are not distinguished and are uniformly labeled as S curves. Figure 2 It can be seen that the maximum field curvature of the TOF receiving optical system 100 in the sagittal direction under light with a wavelength of 940 nanometers is 0.029 mm, and the maximum field curvature of the TOF receiving optical system 100 in the meridional direction under light with a wavelength of 940 nanometers is 0.110 mm, which meets the requirements for field curvature in the excellent imaging quality standard.
[0121] See also Figure 3 , Figure 3 : shows a distortion diagram of the TOF receiving optical system 100 provided in Example 1, Figure 3 The horizontal axis is distortion, and its unit is percentage. Figure 3The vertical axis is the Y-axis field of view, and its unit is degree. Figure 3 1 and 2 show the distortion of the TOF receiving optical system 100 under light of 920 nanometers, 940 nanometers, and 960 nanometers, respectively. Since the three curves almost overlap, the three curves are not distinguished. Figure 3 It can be seen that the maximum distortion of the TOF receiving optical system 100 is 7.38%.
[0122] See also Figure 4 , Figure 4 The vertical axis chromatic aberration diagram of the TOF receiving optical system 100 provided in Example 1 under light with wavelengths of 920 nanometers, 940 nanometers, and 960 nanometers is shown. Figure 4 The horizontal axis is the position of light of different wavelengths on the vertical axis image plane B, in microns. Figure 4 The vertical axis is the field of view, and its unit is degree. Figure 4 There are three curves in total, among which the wavelength of the M1 curve located at 0 micrometers on the horizontal axis is 940 nanometers, the wavelength of the M2 curve is 920 nanometers, and the wavelength of the M3 curve is 960 nanometers. Figure 4 It can be seen that within the full field of view, the maximum vertical chromatic aberration is less than 1 micron, the chromatic aberration is small, and the dispersion is not obvious, which meets the requirements for chromatic aberration in the excellent imaging quality standard.
[0123] Example 2
[0124] Figure 5 The schematic diagram of the architecture layout of the TOF receiving optical system 100 provided in Example 2 is shown. The TOF receiving optical system 100 provided in Example 2 includes, from the object plane A to the image plane B along the optical axis S, an aperture 60, a first aspheric lens 10, a super lens 20, a second aspheric lens 30, a third aspheric lens 40 and a fourth aspheric lens 50, wherein the micro-nano structure 220 is provided on the object side of the substrate 210, the filter is a coating, and the filter is provided on the object side of the super lens 20. Some parameters of the TOF receiving optical system 100 provided in Example 2 are shown in Table 2-1.
[0125] Table 2-1. Partial parameters of the TOF receiving optical system 100 provided in Example 2
[0126] parameter data Total optical length (TTL) 2.25mm Maximum field of view (2ω) 84° F-number 1.95 Effective focal length 2.02mm Working band Near infrared (920nm-960nm)
[0127] As can be seen from Table 2-1, the operating wavelength band of the TOF receiving optical system 100 is 920 nm to 960 nm. The total optical length of the TOF receiving optical system 100 is relatively short, only 2.25 mm, so the volume of the TOF receiving optical system 100 provided in Example 2 is relatively small.
[0128] Along the optical axis S from the object plane A to the image plane B, starting from the aperture 60, each surface in the TOF receiving optical system 100 is numbered, and the parameters of each surface are summarized to obtain the following Table 2-2.
[0129] Table 2-2. Parameters of various surfaces in the TOF receiving optical system 100 provided in Example 2
[0130] Surface serial number Surface type Curvature radius (mm) Thickness(mm) Refractive Index and Abbe Number of Materials 1 Aperture unlimited -0.18 - 2 Aspheric 0.76 0.3 1.64，23.5 3 Aspheric 1.6 0.1 - 4 Structural surface unlimited 0.2 1.46，67.8 5 Spherical unlimited 0.1 - 6 Aspheric -4.7 0.3 1.65，21.5 7 Aspheric -5.3 0.2 - 8 Aspheric -2.2 0.2 1.53，56.0 9 Aspheric -0.6 0.1 - 10 Aspheric -0.71 0.3 1.64，23.5 11 Aspheric 2.22 0.45 - 12 Image plane - - -
[0131] For the analysis of Table 2-2, please refer to Example 1, and no further analysis will be given in this example.
[0132] Surface 2, surface 3, surface 6, surface 7, surface 8, surface 9, surface 10, and surface 11 are all even-order aspheric surfaces, and their surface shapes satisfy the following relationship:
[0133]
[0134] Among them, Z(r) is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of r along the optical axis SS; c is the curvature of the aspherical surface, c=1 / R, R is the radius of curvature of the aspherical surface; k is the cone coefficient; A, B, C, D... are the aspherical coefficients. The values of k, A, B, C, D... of Surface 2, Surface 3, Surface 6, Surface 7, Surface 8, Surface 9, Surface 10, Surface 11 can all be obtained from Table 2-3.
[0135] Table 2-3. Coefficients of the even-order aspheric surfaces in the TOF receiving optical system 100 provided in Example 2
[0136]
[0137]
[0138] The method for looking up the coefficients of the even-order aspheric surfaces of Surface 2, Surface 3, Surface 6, Surface 7, Surface 8, Surface 9, Surface 10, and Surface 11 from Table 2-3 can be referred to Example 1, and will not be elaborated one by one in this embodiment.
[0139] See also Figure 6 , Figure 6 : shows a field curvature diagram of the TOF receiving optical system 100 provided in Example 2, Figure 6 The horizontal axis is the field curvature, and its unit is millimeters. Figure 6 The vertical axis is the Y-axis field of view, and its unit is degree. Figure 6The field curvatures of 920 nm, 940 nm, and 960 nm light in the meridional and sagittal directions are shown in the figure. Since the field curvature curves of 920 nm, 940 nm, and 960 nm light in the meridional direction are relatively concentrated, the field curvature curves of 920 nm, 940 nm, and 960 nm light in the meridional direction are not distinguished and are uniformly labeled as T curves; the field curvature curves of 920 nm, 940 nm, and 960 nm light in the sagittal direction are not distinguished and are uniformly labeled as S curves. Figure 6 It can be seen that the maximum field curvature of the TOF receiving optical system 100 in the sagittal direction under light with a wavelength of 940 nanometers is 0.05 mm, and the maximum field curvature of the TOF receiving optical system 100 in the meridional direction under light with a wavelength of 940 nanometers is 0.114 mm, which meets the requirements for field curvature in the excellent imaging quality standard.
[0140] See also Figure 7 , Figure 7 : shows a distortion diagram of the TOF receiving optical system 100 provided in Example 2, Figure 7 The horizontal axis is distortion, and its unit is percentage. Figure 7 The vertical axis is the Y-axis field of view, and its unit is degree. Figure 7 1 and 2 show the distortion of the TOF receiving optical system 100 under light of 920 nanometers, 940 nanometers, and 960 nanometers, respectively. Since the three curves almost overlap, the three curves are not distinguished. Figure 7 It can be seen that the maximum distortion of the TOF receiving optical system 100 is 8.85%.
[0141] See also Figure 8 , Figure 8 The vertical axis chromatic aberration diagram of the TOF receiving optical system 100 provided in Example 2 under light with wavelengths of 920 nanometers, 940 nanometers, and 960 nanometers is shown. Figure 8 The horizontal axis is the position of light of different wavelengths on the vertical axis image plane, in microns. Figure 8 The vertical axis is the field of view, and its unit is degree. Figure 8 There are three curves in total, among which the wavelength of the M1 curve located at 0 micrometers on the horizontal axis is 940 nanometers, the wavelength of the M2 curve is 920 nanometers, and the wavelength of the M3 curve is 960 nanometers. Figure 8 It can be seen that within the full field of view, the maximum vertical chromatic aberration is less than 1 micron, the chromatic aberration is small, and the dispersion is not obvious, which meets the requirements for chromatic aberration in the excellent imaging quality standard.
[0142] Example 3
[0143] Fig. 9The schematic diagram of the architecture layout of the TOF receiving optical system 100 provided in Example 3 is shown. The TOF receiving optical system 100 provided in Example 3 includes, from the object plane A to the image plane B along the optical axis S, an aperture 60, a first aspheric lens 10, a super lens 20, a second aspheric lens 30, a third aspheric lens 40 and a fourth aspheric lens 50, wherein the micro-nano structure 220 is arranged on the object side of the substrate 210, the filter is a coating, and the filter is arranged on the image side of the super lens 20. Some parameters of the TOF receiving optical system 100 provided in Example 3 are shown in Table 3-1.
[0144] Table 3-1. Partial parameters of the TOF receiving optical system 100 provided in Example 3
[0145] parameter data Total optical length (TTL) 2.1mm Maximum field of view (2ω) 84° F-number 1.80 Effective focal length 1.79mm Working band Near infrared (920nm-960nm)
[0146] As can be seen from Table 3-1, the operating wavelength band of the TOF receiving optical system 100 is 920 nm to 960 nm. The total optical length of the TOF receiving optical system 100 is relatively short, only 2.1 mm, so the volume of the TOF receiving optical system 100 provided in Example 3 is relatively small.
[0147] Along the optical axis S from the object plane A to the image plane B, starting from the aperture 60, each surface in the TOF receiving optical system 100 is numbered, and the parameters of each surface are summarized to obtain the following Table 3-2.
[0148] Table 3-2. Parameters of various surfaces in the TOF receiving optical system 100 provided in Example 3
[0149] Surface serial number Surface type Curvature radius (mm) Thickness(mm) Refractive Index and Abbe Number of Materials 1 Aperture unlimited -0.22 - 2 Aspheric 0.76 0.3 1.64，24.0 3 Aspheric 1.71 0.1 - 4 Structural surface unlimited 0.2 1.46，67.8 5 Spherical unlimited 0.1 - 6 Aspheric -2.1 0.2 1.65，21.5 7 Aspheric -1.8 0.2 - 8 Aspheric -2.1 0.2 1.64，24.0 9 Aspheric -4.3 0.1 - 10 Aspheric 0.89 0.3 1.66，20.3 11 Aspheric 0.78 0.4 - 12 Image plane - - -
[0150] For the analysis of Table 3-2, please refer to Example 1, and no further analysis will be given in this example.
[0151] Surface 2, surface 3, surface 6, surface 7, surface 8, surface 9, surface 10, and surface 11 are all even-order aspheric surfaces, and their surface shapes satisfy the following relationship:
[0152]
[0153] Among them, Z(r) is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of r along the optical axis SS; c is the curvature of the aspherical surface, c=1 / R, R is the radius of curvature of the aspherical surface; k is the cone coefficient; A, B, C, D... are the aspherical coefficients. The values of k, A, B, C, D... of Surface 2, Surface 3, Surface 6, Surface 7, Surface 8, Surface 9, Surface 10, Surface 11 can all be obtained from Table 3-3.
[0154] Table 3-3. Coefficients of the even-order aspheric surfaces in the TOF receiving optical system 100 provided in Example 3
[0155] Surface serial number K A B C D E F G 2 3.75E-01 -4.25E-02 -1.09E-02 -5.37E-01 -9.11E-01 2.25E+01 -5.73E+01 0.00E+00 3 -1.19E+00 7.51E-02 3.44E-01 8.32E-01 7.09E-01 -2.16E+02 7.67E+02 0.00E+00 6 1.78E+01 -1.31E-01 1.35E+00 -1.73E+01 -2.13E+00 6.40E+02 -1.96E+03 0.00E+00 7 7.29E+00 3.84E-01 -1.46E+00 2.70E+00 5.43E+00 -3.08E+00 1.15E+01 0.00E+00 8 -8.21E+01 2.04E-01 -1.18E+00 1.59E+00 -9.66E-01 1.97E-01 6.87E-02 0.00E+00 9 1.30E+01 -2.02E-02 4.52E-02 2.58E-01 -2.86E-01 1.86E-02 4.51E-02 0.00E+00 10 -8.52E+00 -4.42E-01 -9.31E-01 1.60E+00 -6.98E-01 4.21E-03 3.85E-02 0.00E+00 11 -3.56E+00 -5.30E-01 4.38E-01 -2.51E-01 4.75E-02 1.82E-02 -8.61E-03 0.00E+00
[0156] The method for looking up the coefficients of the even-order aspheric surfaces of Surface 2, Surface 3, Surface 6, Surface 7, Surface 8, Surface 9, Surface 10, and Surface 11 from Table 3-3 can be referred to Example 1, and will not be elaborated one by one in this embodiment.
[0157] See also Fig.10 , Fig.10 : shows a field curvature diagram of the TOF receiving optical system 100 provided in Example 3, Fig.10 The horizontal axis is the field curvature, and its unit is millimeters. Fig.10 The vertical axis is the Y-axis field of view, and its unit is degree. Fig.10 The field curvatures of 920 nm, 940 nm, and 960 nm light in the meridional and sagittal directions are shown in the figure. Since the field curvature curves of 920 nm, 940 nm, and 960 nm light in the meridional direction are relatively concentrated, the field curvature curves of 920 nm, 940 nm, and 960 nm light in the meridional direction are not distinguished and are uniformly labeled as T curves; the field curvature curves of 920 nm, 940 nm, and 960 nm light in the sagittal direction are not distinguished and are uniformly labeled as S curves. Fig.10 It can be seen that the maximum field curvature of the TOF receiving optical system 100 in the sagittal direction is 0.038 mm, and the maximum field curvature of the TOF receiving optical system 100 in the meridional direction is 0.098 mm, which meets the requirements for field curvature in the excellent imaging quality standard.
[0158] See also Fig.11 , Fig.11 : shows a distortion diagram of the TOF receiving optical system 100 provided in Example 3, Fig.11 The horizontal axis is distortion, and its unit is percentage. Fig.11 The vertical axis is the Y-axis field of view, and its unit is degree. Fig.11 1 and 2 show the distortion of the TOF receiving optical system 100 under light of 920 nanometers, 940 nanometers, and 960 nanometers, respectively. Since the three curves almost overlap, the three curves are not distinguished. Fig.11 It can be seen that the maximum distortion of the TOF receiving optical system 100 is 7.86%.
[0159] See also Fig.12 , Fig.12 The vertical axis chromatic aberration diagram of the TOF receiving optical system 100 provided in Example 3 under light with wavelengths of 920 nanometers, 940 nanometers, and 960 nanometers is shown. Fig.12 The horizontal axis is the position of light of different wavelengths on the vertical axis image plane, in microns. Fig.12 The vertical axis is the field of view, and its unit is degree. Fig.12 There are three curves in total, among which the wavelength of the M1 curve located at 0 micrometers on the horizontal axis is 940 nanometers, the wavelength of the M2 curve is 920 nanometers, and the wavelength of the M3 curve is 960 nanometers. Fig.12 It can be seen that within the full field of view, the maximum vertical chromatic aberration is less than 1 micron, the chromatic aberration is small, and the dispersion is not obvious, which meets the requirements for chromatic aberration in the excellent imaging quality standard.
[0160] After summarizing the various parameters of the TOF receiving optical system 100 provided by the above three embodiments, the following Table 4 is obtained. Table 4 is mainly used to illustrate that various conditions satisfied by the TOF receiving optical system 100 provided by the present application are all verified and supported by experiments.
[0161] Table 4. Parameters of the TOF receiving optical system 100 provided in various embodiments
[0162]
[0163]
[0164] The present application also provides a TOF receiving optical mirror (not shown), which includes an imaging detector (not shown) and the above-mentioned TOF receiving optical system 100. The architecture of the TOF receiving optical system 100 can be referred to above and will not be repeated here. The imaging detector is arranged on the image plane B of the TOF receiving optical system 100, and the imaging detector includes but is not limited to CMOS (Complementary Metal Oxide Semiconductor, referred to as CMOS, complementary metal oxide semiconductor) and CCD (Charge Coupled Device, referred to as CCD, charge coupled device).
[0165] Since the volume of the TOF receiving optical system 100 is relatively small, the volume of the TOF receiving optical mirror is also relatively small, so that the TOF receiving optical mirror has a lower requirement for the installation space, and thus the TOF receiving optical mirror has a wider application range in various electronic devices.
[0166] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the utility model disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the appended claims.
Claims
1. A TOF receiving optical system, characterized in that: The TOF receiving optical system includes, in order from the object side to the image side along the optical axis: a first aspheric lens, a super lens, a second aspheric lens, a third aspheric lens and a fourth aspheric lens; the optical power of the first aspheric lens is positive, the object side surface of the first aspheric lens is convex to the object side, and the image side surface of the first aspheric lens is convex to the object side; the optical power of the super lens is positive; the optical power of the second aspheric lens is negative, the object side surface of the second aspheric lens is convex to the image side, and the image side surface of the second aspheric lens is convex to the image side; the optical power of the third aspheric lens is positive, and the object side surface of the third aspheric lens is convex to the image side; the optical power of the fourth aspheric lens is negative; The TOF receiving optical system meets the following requirements: Among them, the f m is the focal length of the superlens, and f is the effective focal length of the TOF receiving optical system.
2. The TOF receiving optical system according to claim 1, characterized in that: The TOF receiving optical system meets the following requirements: Wherein, Δλ is the difference between the maximum wavelength and the minimum wavelength of the working band of the TOF receiving optical system, is the phase of the superlens, and x is the distance between the point on the superlens and the center of the superlens.
3. The TOF receiving optical system according to claim 1, characterized in that: The TOF receiving optical system meets the following requirements: Wherein, n1 is the refractive index of the first aspheric lens, EPD is the entrance pupil diameter of the TOF receiving optical system, and R F1 is the radius of curvature of the object side of the first aspheric lens, and the K F1 is the cone coefficient of the object side surface of the first aspheric lens.
4. The TOF receiving optical system according to claim 1, characterized in that: The TOF receiving optical system meets the following requirements: Among them, the R L1 is the radius of curvature of the object side of the fourth aspheric lens, and the R L2 is the curvature radius of the image side surface of the fourth aspheric lens, and the K L1 is the cone coefficient of the object side of the fourth aspheric lens, and the K L2 is the cone coefficient of the image-side surface of the fourth aspheric lens.
5. The TOF receiving optical system according to claim 1, characterized in that: The TOF receiving optical system meets the following requirements: Among them, the TTL is the total optical length of the TOF receiving optical system, the CT1 is the center thickness of the first aspheric lens, the CT3 is the center thickness of the second aspheric lens, the CT4 is the center thickness of the third aspheric lens, and the CT5 is the center thickness of the fourth aspheric lens.
6. The TOF receiving optical system according to claim 1, characterized in that: The TOF receiving optical system meets the following requirements: Among them, the R L1 is the radius of curvature of the object side of the fourth aspheric lens, and the R L2 is the curvature radius of the image side surface of the fourth aspheric lens, n4 is the refractive index of the fourth aspheric lens, and CT5 is the center thickness of the fourth aspheric lens.
7. The TOF receiving optical system according to claim 1, characterized in that: The TOF receiving optical system meets the following requirements: Wherein, the EPD is the entrance pupil diameter of the TOF receiving optical system, and f is the effective focal length of the TOF receiving optical system.
8. The TOF receiving optical system according to claim 1, characterized in that: The TOF receiving optical system satisfies: i >1.6; vd i <25, where n i is the minimum value of the refractive index of the first aspheric lens, the second aspheric lens, and the fourth aspheric lens, vd i is the maximum value of the Abbe numbers of the first aspheric lens, the second aspheric lens, and the fourth aspheric lens.
9. The TOF receiving optical system according to any one of claims 1 to 8, characterized in that: The TOF receiving optical system further includes an aperture, and the aperture is arranged on the object side of the first aspheric lens; or, the aperture is arranged between any two adjacent lenses.
10. A TOF receiving optical lens, characterized in that: The TOF receiving optical lens comprises: an imaging detector and a TOF receiving optical system as described in any one of claims 1-9.