Optical system and vehicle-mounted lens

Abstract

The utility model discloses an optical system and a vehicle-mounted lens. The optical system sequentially comprises a first spherical lens with a positive focal length, a second spherical lens with a negative focal length, a third spherical lens with a positive focal length, a super lens with a positive focal length, a fourth spherical lens, a fifth spherical lens with a positive focal length, a sixth spherical lens with a negative focal length and a seventh spherical lens with a negative focal length from the object side to the image side along the optical axis. The surface, away from the object side, of the fourth spherical lens protrudes towards the object side. Wherein the fifth spherical lens is at least glued with the sixth spherical lens. According to the utility model, through the focal power distribution of the spherical lenses and the use of the bonding lens, the optical system has high resolution. Moreover, in any two adjacent lenses in the optical system, the lens diameter of the lens close to the object side is greater than or equal to the lens diameter of the lens close to the image side, so that the optical lens corresponding to the optical system provided by the invention can be installed from one side, and the installation yield can be improved.

Description

Technical Field

[0001] The present application relates to the field of lenses, and in particular to an optical system and a vehicle-mounted lens. Background Art

[0002] The vehicle lens is an important part of the vehicle camera, which is installed on the car to achieve various functions such as image acquisition and video recording. Vehicle cameras can be divided into many types according to the installation location, including front view, surround view, rear view, side view and built-in camera. These lenses play a vital role in the driving safety and monitoring of the vehicle.

[0003] In the prior art, a vehicle-mounted lens usually has a large number of lenses. Since each lens has a certain error during installation, the accumulation of multiple lenses will cause a large overall installation error of the vehicle-mounted lens, making the installation of the vehicle-mounted lens more difficult and resulting in a low installation yield of the vehicle-mounted lens. Utility Model Content

[0004] In view of the above technical problems, the embodiments of the present application provide an optical system and a vehicle-mounted lens, aiming to improve the installation yield of the vehicle-mounted lens.

[0005] According to one aspect of an embodiment of the present application, an optical system is disclosed, wherein the optical system includes, in order from the object side to the image side along the optical axis, a first spherical lens, a second spherical lens, a third spherical lens, a super lens, a fourth spherical lens, a fifth spherical lens, a sixth spherical lens and a seventh spherical lens; the first spherical lens is a positive lens; the second spherical lens is a negative lens; the third spherical lens is a positive lens; the super lens is a positive lens; the surface of the fourth spherical lens away from the object side is convex toward the object side; the fifth spherical lens is a positive lens; the sixth spherical lens is a negative lens; the seventh spherical lens is a negative lens;

[0006] The fifth spherical lens is at least glued to the sixth spherical lens; any two adjacent lenses satisfy: the lens diameter of the lens close to the object side is greater than or equal to the lens diameter of the lens close to the image side.

[0007] In some embodiments, the optical system satisfies:

[0008]

[0009] Wherein, Δλ is the difference between the maximum working wavelength and the minimum working wavelength of the optical system, is the phase provided by the superlens, and x represents the distance from the center of the superlens along the radial direction of the superlens.

[0010] In some embodiments, the optical system satisfies:

[0011]

[0012] Wherein, n7 is the refractive index of the seventh spherical lens, EXP is the exit pupil diameter of the optical system, and R L2 is the curvature radius of the surface of the seventh spherical lens close to the image side.

[0013] In some embodiments, the optical system satisfies:

[0014]

[0015] Wherein, the D1 is the aperture of the first spherical lens, the F# is the F number of the optical system, the EPD is the entrance pupil diameter of the optical system, and the FOV is the field of view angle of the optical system.

[0016] In some embodiments, the optical system satisfies:

[0017]

[0018] Among them, the R L1 is the curvature radius of the surface of the seventh spherical lens close to the object side, and the R L2 is the curvature radius of the surface of the seventh spherical lens close to the image side.

[0019] In some embodiments, the optical system satisfies:

[0020]

[0021] Wherein, the TTL is the total optical length of the optical system, the CT4 is the center thickness of the fourth spherical lens, the CT5 is the center thickness of the fifth spherical lens, and the CT6 is the center thickness of the sixth spherical lens.

[0022] In some embodiments, the optical system satisfies:

[0023]

[0024] Among them, the f m is the focal length of the metalens, and f is the effective focal length of the optical system.

[0025] In some embodiments, when the fifth spherical lens is only cemented with the sixth spherical lens, the optical system satisfies:

[0026]

[0027] Wherein, f5 is the focal length of the fifth spherical lens, and vd5 is the Abbe number of the fifth spherical lens, f6 is the focal length of the sixth spherical lens, and v d6 is the Abbe number of the sixth spherical lens.

[0028] In some embodiments, the fifth spherical lens is also cemented to the fourth spherical lens.

[0029] In some embodiments, the optical system satisfies:

[0030]

[0031] Wherein, f4 is the focal length of the fourth spherical lens, and v d4 is the Abbe number of the fourth spherical lens, f5 is the focal length of the fifth spherical lens, and v d5 is the Abbe number of the fifth spherical lens, f6 is the focal length of the sixth spherical lens, and v d6 is the Abbe number of the sixth spherical lens.

[0032] In some embodiments, the surface of the first spherical lens close to the object side is convex toward the object side, and the surface of the first spherical lens away from the object side is convex toward the object side; the surface of the second spherical lens close to the object side is convex toward the image side, and the surface of the second spherical lens away from the object side is convex toward the object side; the surface of the third spherical lens close to the object side is convex toward the image side, and the surface of the third spherical lens away from the object side is convex toward the image side; the surface of the fourth spherical lens close to the object side is convex toward the object side, and the surface of the fourth spherical lens away from the object side is convex toward the object side; the surface of the fifth spherical lens close to the object side is convex toward the object side, and the surface of the fifth spherical lens away from the object side is convex toward the image side; the surface of the sixth spherical lens close to the object side is convex toward the image side, and the surface of the sixth spherical lens away from the object side is convex toward the image side; the surface of the seventh spherical lens close to the object side is convex toward the image side, and the surface of the seventh spherical lens away from the object side is convex toward the image side;

[0033] or,

[0034] The surface of the first spherical lens close to the object side is convex toward the object side, and the surface of the first spherical lens away from the object side is convex toward the object side; the surface of the second spherical lens close to the object side is convex toward the image side, and the surface of the second spherical lens away from the object side is convex toward the object side; the surface of the third spherical lens close to the object side is convex toward the image side, and the surface of the third spherical lens away from the object side is convex toward the image side; the surface of the fourth spherical lens close to the object side is convex toward the image side, and the surface of the fourth spherical lens away from the object side is convex toward the object side; the surface of the fifth spherical lens close to the object side is convex toward the object side, and the surface of the fifth spherical lens away from the object side is convex toward the image side; the surface of the sixth spherical lens close to the object side is convex toward the image side, and the surface of the sixth spherical lens away from the object side is convex toward the image side; the surface of the seventh spherical lens close to the object side is convex toward the image side, and the surface of the seventh spherical lens away from the object side is convex toward the image side.

[0035] In some embodiments, the optical system further includes an aperture, and the aperture is disposed on a surface of the superlens close to the object side, or the aperture is disposed on a surface of the third spherical lens close to the image side.

[0036] In some embodiments, a surface of the fourth spherical lens close to the object side is convex toward the object side.

[0037] In some embodiments, a surface of the fourth spherical lens close to the object side is convex toward the image side.

[0038] A second aspect of an embodiment of the present application provides a vehicle-mounted lens, comprising: an imaging sensor and the above-mentioned optical system; the imaging sensor is arranged on the image plane of the optical system.

[0039] The optical system provided by the present application includes a first spherical lens, a second spherical lens, a third spherical lens, a super lens, a fourth spherical lens, a fifth spherical lens, a sixth spherical lens and a seventh spherical lens in order from the object side to the image side along the optical axis; the first spherical lens is a positive lens; the second spherical lens is a negative lens; the third spherical lens is a positive lens; the super lens is a positive lens; the surface of the fourth spherical lens away from the object side is convex to the object side; the fifth spherical lens is a positive lens; the sixth spherical lens is a negative lens; the seventh spherical lens is a negative lens; wherein the fifth spherical lens is at least glued to the sixth spherical lens. In the present application, each spherical lens is used to provide a larger optical focal length and correct the main aberration of the paraxial light at the same time. The super lens is used to provide a smaller optical focal length, mainly correcting the residual aberration of the full field of view and the spherical aberration of the edge field of view. Through the distribution of the focal length of each spherical lens and the use of glued lenses, the optical system has a higher resolution. Furthermore, among any two adjacent lenses in the optical system, the lens diameter of the lens close to the object side is greater than or equal to the lens diameter of the lens close to the image side, so that the optical lens corresponding to the optical system provided by the present application can be installed from one side, which is beneficial to reducing installation errors and improving installation yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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.

[0041] Figure 1 A schematic diagram of the architecture layout of an optical system in an embodiment of the present application is shown.

[0042] Figure 2 The MTF field of view curve diagram of the optical system in one embodiment of the present application is shown.

[0043] Figure 3 A field curvature diagram of an optical system in an embodiment of the present application is shown.

[0044] Figure 4 A distortion diagram of an optical system in an embodiment of the present application is shown.

[0045] Figure 5 A vertical axis chromatic aberration diagram of an optical system in an embodiment of the present application is shown.

[0046] Figure 6 A schematic diagram of the architecture layout of an optical system in an embodiment of the present application is shown.

[0047] Figure 7 The MTF field of view curve diagram of the optical system in one embodiment of the present application is shown.

[0048] Figure 8 A field curvature diagram of an optical system in an embodiment of the present application is shown.

[0049] Fig. 9 A distortion diagram of an optical system in an embodiment of the present application is shown.

[0050] Fig.10 A vertical axis chromatic aberration diagram of an optical system in an embodiment of the present application is shown.

[0051] Fig.11 A schematic diagram of the architecture layout of an optical system in an embodiment of the present application is shown.

[0052] Fig.12 The MTF field of view curve diagram of the optical system in one embodiment of the present application is shown.

[0053] Fig.13 A field curvature diagram of an optical system in an embodiment of the present application is shown.

[0054] Fig.14 A distortion diagram of an optical system in an embodiment of the present application is shown.

[0055] Fig.15 A vertical axis chromatic aberration diagram of an optical system in an embodiment of the present application is shown.

[0056] Reference numerals

[0057] 100. Optical system;

[0058] 1. The first spherical lens;

[0059] 2. The second spherical lens;

[0060] 3. The third spherical lens;

[0061] 4. Super lens; 41. Structural surface;

[0062] 5. The fourth spherical lens;

[0063] 6. Fifth spherical lens;

[0064] 7. Sixth spherical lens;

[0065] 8. Seventh spherical lens

[0066] 9. Aperture;

[0067] A, object plane; B, image plane; S, optical axis. DETAILED DESCRIPTION

[0068] 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.

[0069] 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 unclear.

[0070] The present application provides an optical system. The prior art that is closest to the specifications to be achieved by the present application is Chinese Patent CN115826200A. Chinese Patent CN115826200A discloses a low-cost high-definition vehicle-mounted front-view lens, and the effective focal length of the lens is close to the effective focal length of the optical system provided by the present application. The lens diameter of a lens in the middle of the vehicle-mounted lens is smaller than the lens diameter of the lenses on both sides thereof, so that when installing the vehicle-mounted lens, a fixing piece needs to be set at the corresponding position of the lens barrel to fix the lens, and then other lenses are installed from both sides of the lens. Since the introduction of the fixing piece will bring additional assembly tolerance, the assembly yield of the vehicle-mounted lens is low.

[0071] See also Figure 1 , Figure 1 FIG. 1 shows a schematic diagram of the structure layout of an 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 left side of the leftmost lens is the object side, and the object plane A is located on the object side. The right side of the rightmost lens is the image side, 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.

[0072] The optical system 100 includes a first spherical lens 1, a second spherical lens 2, a third spherical lens 3, a super lens 4, a fourth spherical lens 5, a fifth spherical lens 6, a sixth spherical lens 7 and a seventh spherical lens 8. The first spherical lens 1, the second spherical lens 2, the third spherical lens 3, the super lens 4, the fourth spherical lens 5, the fifth spherical lens 6, the sixth spherical lens 7 and the seventh spherical lens 8 are arranged in sequence from the object plane A to the image plane B along the optical axis S.

[0073] The first spherical lens 1 is a meniscus lens, which is a positive lens. The surface of the first spherical lens 1 close to the object plane A is convex toward the object plane A, and the surface of the first spherical lens 1 far from the object plane A is convex toward the object plane A.

[0074] The second spherical lens 2 is a double concave lens, which is a negative lens. The surface of the second spherical lens 2 close to the object plane A is convex toward the image plane B, and the surface of the second spherical lens 2 far from the object plane A is convex toward the object plane A.

[0075] The third spherical lens 3 is a meniscus lens, which is a positive lens. The surface of the third spherical lens 3 close to the object plane A is convex toward the image plane B, and the surface of the third spherical lens 3 away from the object plane A is convex toward the image plane B.

[0076] The superlens 4 is an optical modulation device obtained by setting a structural surface 41 on a substrate, and the structural surface 41 is composed of a plurality of micro-nano structures arranged, and a medium is filled between the micro-nano structures. The medium filled between the micro-nano structures includes but is not limited to air or other materials that are transparent in the working band of the superlens 4. According to the phase modulation method adopted, the various parameters of the micro-nano structure can be adaptively configured using a matching phase modulation formula, so that the superlens 4 can achieve corresponding optical performance.

[0077] The super lens 4 is a positive lens, which is used to converge light and correct aberrations. The structure surface 41 is set on the surface of the super lens 4 close to the object surface A, or the structure surface 41 is set on the surface of the super lens 4 close to the image surface B. Figure 1 , Figure 6 and Fig.11 The structural planes 41 are all arranged on the surface of the metalens 4 close to the object plane A, but it should be noted that the structural plane 41 arranged on the surface of the metalens 4 close to the object plane A and the structural plane 41 arranged on the surface of the metalens 4 close to the image plane B have the same effect, that is, the structural plane 41 is arranged on the surface of the metalens 4 close to the object plane A, or the structural plane 41 is arranged on the surface of the metalens 4 close to the image plane B. Both are within the protection scope of this application. In addition, the structural plane 41 can be arranged in one layer, two layers, or three layers or more.

[0078] The metalens 4 provides different focal lengths in different wavelengths, and the metalens 4 combined with other lenses of the optical system 100 can correct the chromatic aberration of the optical system 100.

[0079] The focal length of the fourth spherical lens 5 can be positive or negative. The surface of the fourth spherical lens 5 away from the object surface A is convex toward the object surface A.

[0080] In some embodiments, the surface of the fourth spherical lens 5 close to the object plane A is convex toward the object plane.

[0081] In some embodiments, the surface of the fourth spherical lens 5 close to the object plane A is convex toward the image plane.

[0082] The fifth spherical lens 6 is a double convex lens, which is a positive lens. The surface of the fifth spherical lens 6 close to the object plane A is convex toward the object plane A, and the surface of the fifth spherical lens 6 away from the object plane A is convex toward the image plane B. The fifth spherical lens 6 is at least glued to the sixth spherical lens 7 .

[0083] The sixth spherical lens 7 is a meniscus lens, which is a negative lens. The surface of the sixth spherical lens 7 close to the object plane A is convex toward the image plane B, and the surface of the sixth spherical lens 7 far from the object plane A is convex toward the image plane B.

[0084] The seventh spherical lens 8 is a meniscus lens, which is a negative lens. The surface of the seventh spherical lens 8 close to the object plane A is convex toward the image plane B, and the surface of the seventh spherical lens 8 away from the object plane A is convex toward the image plane B.

[0085] Any two adjacent lenses among the first spherical lens 1, the second spherical lens 2, the third spherical lens 3, the metalens 4, the fourth spherical lens 5, the fifth spherical lens 6, the sixth spherical lens 7 and the seventh spherical lens 8 satisfy: the lens diameter of the lens close to the object plane A is greater than or equal to the lens diameter of the lens close to the image plane B. For example, the second spherical lens 2 and the third spherical lens 3 are adjacent, and the lens diameter of the second spherical lens 2 is greater than or equal to the lens diameter of the third spherical lens 3, so that the optical lens corresponding to the optical system 100 provided in the present application can be installed from one side, which is conducive to reducing installation errors.

[0086] In some embodiments, the fifth spherical lens 6 is only cemented and connected to the sixth spherical lens 7 to form a doublet.

[0087] In some embodiments, the fifth spherical lens 6 is further cemented and connected to the fourth spherical lens 5 , that is, the fourth spherical lens 5 , the fifth spherical lens 6 and the sixth spherical lens 7 are cemented and connected to form a triplet lens.

[0088] In the present application, each spherical lens is used to provide a larger optical power and correct the main aberration of the paraxial light. The super lens 4 is used to provide a smaller optical power, mainly correcting the residual aberration of the full field of view and the spherical aberration of the edge field of view. Through the distribution of the optical power of each spherical lens and the use of cemented lenses, the optical system has a higher resolution. At the same time, the optical system 100 also has the advantages of suitable high and low temperature compensation, good reliability, high coaxiality and easy processing. In addition, in any two adjacent lenses of the optical system 100 provided by the present application, the lens diameter of the lens close to the object plane A is greater than or equal to the lens diameter of the lens close to the image plane B, so that the optical lens corresponding to the optical system 100 provided by the present application can be installed from one side, which is conducive to reducing installation errors and improving installation yield.

[0089] In some embodiments, the optical system 100 satisfies Condition 1:

[0090]

[0091] Wherein, Δλ is the difference between the maximum working wavelength and the minimum working wavelength of the optical system 100, that is, the wavelength difference. The unit of Δλ is a length unit, and the larger the wavelength difference, the larger the negative chromatic aberration brought by the metalens 4. is the phase provided by the superlens 4, and its unit is 2πrad. x represents the distance between any point on the structural surface 41 and the center of the superlens 4 along the radial direction of the superlens 4, and its unit is the length unit. The unit of x is the same as the unit of Δλ, for example, both are nanometers. Therefore, represents the phase slope of the structural surface 41 of the metalens 4. The phase slope represents the magnitude of the negative chromatic aberration introduced by the structural surface 41. It represents the maximum value of the phase slope of the structural surface 41 of the super lens 4. The upper limit of conditional expression 1 is used to ensure that the positive chromatic aberration brought by each spherical lens can be compensated by the super lens 4, and the lower limit of conditional expression 1 is used to avoid excessive chromatic aberration compensation introduced by the super lens 4.

[0092] Furthermore, the phase distribution of the structural surface 41 satisfies the following formula:

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] Wherein, r is the distance from the center of the superlens 2 to any nanostructure; λ is the operating wavelength of the superlens 2; is any phase related to the working wavelength of the superlens 2; (x, y) is the mirror coordinate of the superlens; a i and b i are real coefficients.

[0102] In some embodiments, the fifth spherical lens 6 is only glued to the sixth spherical lens 7, and the optical system 100 satisfies conditional formula 2:

[0103]

[0104] Wherein, f5 is the focal length of the fifth spherical lens 6, v d5 is the Abbe number of the fifth spherical lens 6, f6 is the focal length of the sixth spherical lens 7, v d6 is the Abbe number of the sixth spherical lens 7.

[0105] For conditional expression 2, f i It can represent the monochromatic aberration of each lens to a certain extent, v di The upper limit of conditional expression 2 ensures the correction of monochromatic aberration of the optical system 100 , and the lower limit of conditional expression 2 ensures the correction of chromatic aberration of the optical system 100 .

[0106] In some embodiments, the fifth spherical lens 6 is also glued with the fourth spherical lens 5, that is, the fourth spherical lens 5, the fifth spherical lens 6 and the sixth spherical lens 7 form a triple glued lens. At this time, the optical system 100 satisfies the conditional formula 3:

[0107]

[0108] Wherein, f4 is the focal length of the fourth spherical lens 5, v d4 is the Abbe number of the fourth spherical lens 5, f5 is the focal length of the fifth spherical lens 6, v d5 is the Abbe number of the fifth spherical lens 6, f6 is the focal length of the sixth spherical lens 7, v d6 is the Abbe number of the sixth spherical lens 7.

[0109] For conditional formula 3, f i It can represent the monochromatic aberration of each lens to a certain extent, v di The upper limit of conditional expression 3 guarantees the correction of monochromatic aberration of the optical system 100 , and the lower limit of conditional expression 3 guarantees the correction of chromatic aberration of the optical system 100 .

[0110] In some embodiments, the optical system 100 satisfies Condition 4:

[0111]

[0112] Wherein, n7 is the refractive index of the seventh spherical lens 8. EXP is the exit pupil diameter of the optical system 100, which is the diameter of the light beam emitted from the optical system 100, and its unit is a length unit. L2 is the curvature radius of the surface of the seventh spherical lens 8 close to the image plane B, and its unit is a length unit. L2 The dimension is the same as the exit pupil diameter EXP of the optical system 100, for example, both are millimeters. For conditional expression 4, its upper and lower limits ensure that the back focus and the incident angle of the main light are within a reasonable range.

[0113] In some embodiments, the optical system 100 satisfies Condition 5:

[0114]

[0115] Wherein, D1 is the aperture of the first spherical lens 1, which is the maximum diameter of the light allowed to pass through the first spherical lens 1, and its unit is a length unit. F# is the F number of the optical system 100, which is also called the aperture, and is the ratio of the focal length of the optical system 100 to the entrance pupil diameter. EPD is the entrance pupil diameter of the optical system 100, and its unit is a length unit. The entrance pupil diameter EPD of the optical system 100 and the aperture D1 of the first spherical lens 1 have the same dimension, for example, both are millimeters. FOV is the field of view of the optical system 100, and its unit is degrees.

[0116] Conditional formula 5 guarantees the aperture and image plane size of the optical system 100. The upper limit of conditional formula 5 limits the aperture of the optical system 100 to an acceptable range, so that it is not too large to increase the volume of the entire optical system 100. The lower limit of conditional formula 5 ensures that the image plane size and entrance pupil diameter of the optical system 100 meet the preset requirements and are adapted to the field of view, so that they are not too large or too small.

[0117] In some embodiments, the optical system 100 satisfies Conditional Formula 6:

[0118]

[0119] Among them, R L1 is the curvature radius of the surface of the seventh spherical lens 8 close to the object surface A, R L2 is the curvature radius of the surface of the seventh spherical lens 8 close to the image plane B.

[0120] Conditional formula 6 represents the light-gathering ability and processability of the seventh spherical lens 8. The lower limit of conditional formula 6 is used to ensure that the surface of the seventh spherical lens 8 close to the object surface A and the surface close to the image surface B have a suitable radius of curvature, which is easy to center. The upper limit of conditional formula 6 is used to ensure the light-gathering ability of the seventh spherical lens 8, which helps to reduce the aberration of the optical system 100 and control the back focus size of the optical system 100.

[0121] In some embodiments, the optical system 100 satisfies conditional equation 7:

[0122]

[0123] Among them, TTL (Total Track Length, abbreviated as TTL, total optical length) is the total optical length of the optical system 100, and the total optical length is the distance from the center of the surface of the first spherical lens 1 close to the object plane A to the image plane, and its unit is the length unit. In the present application, the center thickness of each spherical lens is the thickness of each spherical lens on the optical axis S. CT4 is the center thickness of the fourth spherical lens 5, and its unit is the length unit. CT5 is the center thickness of the fifth spherical lens 6, and its unit is the length unit. CT6 is the center thickness of the sixth spherical lens 7, and its unit is the length unit. The total optical length TTL, the center thickness CT4 of the fourth spherical lens 5, the center thickness CT5 of the fifth spherical lens 6, and the center thickness CT6 of the sixth spherical lens 7 have the same dimension, for example, all are millimeters.

[0124] The upper limit of conditional formula 7 limits the total optical length of the optical system 100 and the total thickness of the fourth spherical lens 5, the fifth spherical lens 6 and the sixth spherical lens 7 to not be less than a certain ratio. Since the total optical length is limited by a preset value, and thicker lenses help reduce the field curvature of the optical system 100, the fourth spherical lens 5, the fifth spherical lens 6 and the sixth spherical lens 7 are appropriately thickened to reduce the field curvature of the optical system 100. The lower limit of conditional formula 7 is used to limit the thickness of the fourth spherical lens 5, the fifth spherical lens 6 and the sixth spherical lens 7 to avoid the thickness of the fourth spherical lens 5, the fifth spherical lens 6 and the sixth spherical lens 7 being too large. The thickness of the fourth spherical lens 5, the fifth spherical lens 6 and the sixth spherical lens 7 within a reasonable range can reserve space for other lenses and air gaps, which is convenient for matching the material and curvature of the lens to eliminate chromatic aberration.

[0125] In some embodiments, the optical system 100 satisfies Conditional Equation 8:

[0126]

[0127] Among them, f m is the focal length of the metalens 4, and its unit is the length unit. f is the effective focal length of the optical system 100, and its unit is the length unit. m The dimension is the same as the effective focal length f of the optical system 100, for example, millimeters.

[0128] Conditional formula eight is mainly used for aberration compensation of the entire field of view and spherical aberration correction of the edge field of view. The upper limit of conditional formula eight ensures that the metalens 4 has a certain focal length, and can complete light adjustment within the length of the optical system 100 to ensure the compensation capability of aberrations, etc. The lower limit of conditional formula eight is to avoid overcompensation caused by providing a large focal length of the metalens 4. If the focal length of the metalens 4 is too large, it will bring greater dispersion to the optical system 100.

[0129] In some embodiments, the optical system 100 further includes an aperture 9, which is used to adjust the total amount of light entering the optical system 100. The aperture 9 is disposed on the surface of the metalens 4 close to the object plane A, or the aperture 9 is disposed on the surface of the third spherical lens 3 close to the image plane B.

[0130] In some embodiments, the fourth spherical lens 5 is a meniscus lens, and is a positive lens. The surface of the fourth spherical surface close to the object surface A is convex toward the object surface A.

[0131] In some embodiments, the fourth spherical lens 5 is a biconcave lens, which is a negative lens. The surface of the fourth spherical lens 5 close to the object plane A is convex toward the image plane B.

[0132] In summary, the conventional lenses of the optical system 100 in the present application are all spherical lenses, which have the advantages of simple structure and low cost compared to the optical system 100 with aspherical lenses. Each spherical lens is used to provide a larger optical focal length and correct the main aberration of the paraxial light. The super lens 4 is used to provide a smaller optical focal length, mainly correcting the residual aberration of the full field of view and the spherical aberration of the edge field of view. Through the distribution of the optical focal length of each spherical lens and the use of a cemented lens, the lens has a higher resolution. At the same time, the optical system 100 also has the advantages of suitable high and low temperature compensation, good reliability, high coaxiality and easy processing.

[0133] The present application illustratively provides three optical systems 100 that meet usage requirements in three embodiments. Next, the optical system 100 provided by each embodiment of the present application is described in detail.

[0134] Example 1

[0135] Figure 1 A schematic diagram of the architecture layout of the optical system 100 in Example 1 provided in the present application is shown. In Example 1, the optical system 100 includes, along the optical axis S from the object plane A to the image plane B, a first spherical lens 1, a second spherical lens 2, a third spherical lens 3, a super lens 4, a fourth spherical lens 5, a fifth spherical lens 6, a sixth spherical lens 7 and a seventh spherical lens 8, wherein the fourth spherical lens 5, the fifth spherical lens 6 and the sixth spherical lens 7 are glued together to form a triplet lens.

[0136] Table 1. Some parameters of the optical system 100

[0137]

[0138]

[0139] As can be seen from Table 1, the optical system 100 in this embodiment has an operating band of 400 nanometers to 700 nanometers, which meets the working requirements of the visible light band. The F number (aperture) of the optical system 100 is 1.6, which can greatly increase the amount of light entering the optical system 100, and collect as much energy as possible entering the optical system 100 when the image sensor has a low response to light energy, thereby ensuring excellent imaging quality. The field of view angle of the optical system 100 is 34.4°. At the same time, the total optical length is only 30 mm, which fully meets the requirements of the optical system 100 for miniaturization and thinness, and is conducive to the control of its volume.

[0140] Starting from the first spherical lens 1 , along the optical axis S from the object plane A to the image plane B, each surface in the optical system 100 is numbered, and the parameters of each surface are summarized to obtain the following Table 2.

[0141] Table 2. Parameters of various surfaces in the optical system 100 provided in Example 1

[0142] Surface serial number Surface type Curvature radius (mm) Thickness(mm) Refractive Index Abbe number 1 Spherical 13.3 2.4 1.80 46.6 2 Spherical 45.3 1.3 - - 3 Spherical -24.5 1.0 1.60 38.0 4 Spherical 12.6 1.7 - 5 Spherical -18.2 3.8 1.83 42.7 6 Spherical -14.5 0.1 - - 7 Aperture unlimited 0 - - 8 Metasurface unlimited 0.725 1.46 67.8 9 Spherical unlimited 0.1 - - 10 Spherical 10.4 4.4 1.72 47.9 11 Spherical 30.0 4.0 1.60 68.3 12 Spherical -8.0 2.1 1.76 26.6 13 Spherical -17.0 4.4 - - 14 Spherical -6.6 1.0 1.52 64.2 15 Spherical -20.0 3.0 - - 16 Spherical unlimited - - -

[0143] For each surface in Table 2, surface 1 is the surface of the first spherical lens 1 close to the object plane A, and surface 2 is the surface of the first spherical lens 1 close to the image plane B. Surface 3 is the surface of the second spherical lens 2 close to the object plane A, and surface 4 is the surface of the second spherical lens 2 close to the image plane B. Surface 5 is the surface of the third spherical lens 3 close to the object plane A, and surface 6 is the surface of the third spherical lens 3 close to the image plane B. Surface 7 is the aperture 9, surface 8 is the surface of the metalens 4 close to the object plane A, the micro-nano structure is provided on surface 8, and surface 9 is the surface of the metalens 4 close to the image plane B. Surface 10 is the surface of the fourth spherical lens 5 close to the object plane A, surface 11 is the cemented surface of the surface of the fourth spherical lens 5 close to the image plane B and the surface of the fifth spherical lens 6 close to the image plane B. Surface 12 is the cemented surface of the surface of the fifth spherical lens 6 close to the image plane B and the surface of the sixth spherical lens 7 close to the object plane A, and surface 13 is the surface of the sixth spherical lens 7 close to the image plane B. Surface 14 is the surface of the seventh spherical lens 8 close to the object plane A, and surface 15 is the surface of the seventh spherical lens 8 close to the image plane B. Surface 16 is the image plane.

[0144] Surface 1 is a spherical surface, the radius of curvature of surface 1 is 13.3 mm, and the distance between surface 1 and surface 2 is 2.4 mm. Surface 2 is a spherical surface, the radius of curvature of surface 2 is 45.3 mm, the distance between surface 2 and surface 3 is 1.3 mm, and the material between surface 2 and surface 3 is air. The refractive index of the first spherical lens 1 is 1.80, the Abbe number of the first spherical lens 1 is 46.6, and the material of the first spherical lens 1 is glass.

[0145] Surface 3 is a spherical surface, the radius of curvature of surface 3 is -24.5 mm, and the distance between surface 3 and surface 4 is 1.0 mm. Surface 4 is a spherical surface, the radius of curvature of surface 4 is 12.6 mm, the distance between surface 4 and surface 5 is 1.7 mm, and the material between surface 4 and surface 5 is air. The refractive index of the second spherical lens 2 is 1.60, the Abbe number of the second spherical lens 2 is 38.0, and the material of the second spherical lens 2 is glass.

[0146] Surface 5 is a spherical surface, the radius of curvature of surface 3 is -18.2 mm, and the distance between surface 5 and surface 6 is 3.8 mm. Surface 6 is a spherical surface, the radius of curvature of surface 6 is -14.5 mm, the distance between surface 6 and surface 7 is 0.1 mm, and the material between surface 6 and surface 7 is air. The refractive index of the third spherical lens 3 is 1.83, the Abbe number of the third spherical lens 3 is 42.7, and the material of the third spherical lens 3 is glass.

[0147] The curvature radius of surface 8 is infinite, that is, surface 8 is a plane, and the distance between surface 8 and surface 9 is 0.725 mm. The curvature radius of surface 9 is infinite, that is, surface 9 is a plane, and the distance between surface 9 and surface 10 is 0.1 mm, and the material between surface 9 and surface 10 is air. The equivalent refractive index of superlens 4 is 1.46, the equivalent Abbe number of superlens 4 is 67.8, and the material of superlens 4 is silicon dioxide.

[0148] The surface 10 is a spherical surface, the curvature radius of the surface 10 is 10.4 mm, and the distance between the surface 10 and the surface 11 is 4.4 mm. The refractive index of the fourth spherical lens 5 is 1.72, the Abbe number of the fourth spherical lens 5 is 47.9, and the material of the fourth spherical lens 5 is glass.

[0149] The surface 11 is a spherical surface, the curvature radius of the surface 11 is 30 mm, and the distance between the surface 11 and the surface 12 is 4.0 mm. The refractive index of the fifth spherical lens 6 is 1.60, the Abbe number of the fifth spherical lens 6 is 68.3, and the material of the fifth spherical lens 6 is glass.

[0150] Surface 12 is a spherical surface, the radius of curvature of surface 12 is -8.0 mm, and the distance between surface 12 and surface 13 is 2.1 mm. Surface 13 is a spherical surface, the radius of curvature of surface 13 is -17.0 mm, and the distance between surface 13 and surface 14 is 4.0 mm. The refractive index of the sixth spherical lens 7 is 1.76, the Abbe number of the sixth spherical lens 7 is 26.6, and the material of the sixth spherical lens 7 is glass.

[0151] Surface 14 is a spherical surface, the radius of curvature of surface 14 is -6.6 mm, and the distance between surface 14 and surface 15 is 1.0 mm. Surface 15 is a spherical surface, the radius of curvature of surface 15 is -20 mm, and the distance between surface 15 and surface 16 is 3.0 mm. The refractive index of the seventh spherical lens 8 is 1.52, the Abbe number of the sixth spherical lens 7 is 64.2, and the material of the seventh spherical lens 8 is glass.

[0152] See also Figure 2 , Figure 2 The MTF (Modulation Transfer Function, MTF for short) field of view curve of the optical system 100 provided in Example 1 is shown. MTF is also called modulation transfer function, which is an important indicator for describing the imaging quality of the optical system 100. The larger the MTF value, the better the imaging quality. Figure 2 The sagittal curve S1 and the meridional curve T1 of the MTF of 120lp / mm spatial frequency as the field of view changes, and the sagittal image curve S2 and the meridional image curve T2 of the MTF of 200lp / mm spatial frequency as the field of view changes are listed. Figure 2 The horizontal axis in is the field of view in the Y-axis direction. Figure 2 The vertical axis in is the MTF value. It can be seen from the above four curves that the MTF of the optical system 100 within the 17.2° (2ω=34.4°) field of view is always greater than 0.45, so the optical system 100 has a good imaging quality.

[0153] See also Figure 3 , Figure 3 The field curvature of the optical system 100 provided in Example 1 under visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns is shown, wherein L1, L2, L3, L4 and L5 are the field curvatures of visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns in the meridional direction, and L6, L7, L8, L9 and L10 are the field curvatures of visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns in the sagittal direction. Figure 3 It can be seen that the maximum difference in field curvature of the central field of view is 0.08 mm, and the maximum difference in field curvature of the edge field of view is 0.09 mm, which meets the requirements for field curvature in the excellent imaging quality standard.

[0154] Figure 4 The distortion of the optical system 100 provided in Example 1 under visible light with wavelengths of 0.435 μm, 0.486 μm, 0.546 μm, 0.587 μm and 0.656 μm is shown ( Figure 4A total of five curves are shown in FIG, but the gaps between the five curves are extremely small, resulting in the five curves almost overlapping). Figure 4 The horizontal axis is the degree of image distortion, and its unit is percentage. Figure 4 The vertical coordinate is the normalized field of view in the positive direction of the Y axis. Therefore, the maximum distortion of the optical system 100 is -2.1%. Therefore, the distortion of the optical system 100 is small, and the distortion requirement of the excellent imaging quality standard is met.

[0155] Figure 5 The vertical axis chromatic aberration of the optical system 100 at wavelengths of 0.587 microns, 0.486 microns, 0.656 microns and 0.435 microns is shown in Example 1, with the position of the visible light with a wavelength of 0.546 microns and the image plane focus as the reference, wherein: Figure 5 The middle curves M1, M2, M3, M4 and M5 represent visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns respectively. Figure 5 It can be seen that the vertical axis chromatic aberration of the optical system 100 is within the range of 1 micron, which meets the requirements of the excellent imaging quality standard for vertical axis chromatic aberration.

[0156] Example 2

[0157] Figure 6 A schematic diagram of the architecture layout of the optical system 100 in Example 2 provided in the present application is shown. In Example 2, the optical system 100 includes, along the optical axis S from the object plane A to the image plane B, a first spherical lens 1, a second spherical lens 2, a third spherical lens 3, a super lens 4, a fourth spherical lens 5, a fifth spherical lens 6, a sixth spherical lens 7 and a seventh spherical lens 8, wherein the fifth spherical lens 6 and the sixth spherical lens 7 are glued together to form a double glued lens.

[0158] Table 3. Some parameters of the optical system 100

[0159] parameter data System volume (TTL) 27.3mm Field of view (2ω) 34.4° F-number 1.65 Effective focal length 15.23mm Working band Visible light (400nm-700nm)

[0160] As can be seen from Table 3, the optical system 100 in this embodiment has an operating band of 400 nanometers to 700 nanometers, which meets the working requirements of the visible light band. The F number (aperture) of the optical system 100 is 1.65, which can greatly increase the amount of light entering the optical system 100, and collect as much energy as possible entering the optical system 100 when the image sensor has a low response to light energy, thereby ensuring excellent imaging quality. The field of view angle of the optical system 100 is 34.4°. At the same time, the total optical length is only 27.3 mm, which fully meets the requirements of the optical system 100 for miniaturization and thinness, and is conducive to the control of its volume.

[0161] Starting from the first spherical lens 1 , along the optical axis S from the object plane A to the image plane B, each surface in the optical system 100 is numbered, and the parameters of each surface are summarized to obtain the following Table 4.

[0162] Table 4. Parameters of various surfaces in the optical system 100 provided in Example 2

[0163] Surface serial number Surface type Curvature radius (mm) Thickness(mm) Refractive Index Abbe number 1 Spherical 11.0 2.4 1.80 46.6 2 Spherical 27.6 0.8 - - 3 Spherical -27.5 1.0 1.65 33.9 4 Spherical 8.6 2.5 - - 5 Spherical 11.4 2.9 1.91 35.0 6 Spherical -27.5 -0.04 - - 7 Aperture unlimited 1.1 - - 8 Metasurface unlimited 0.725 1.46 67.8 9 Spherical unlimited 0.16 - - 10 Spherical -53.5 1.5 1.62 36.3 11 Spherical 25.6 0.1 - - 12 Spherical 17.0 3.3 1.72 47.9 13 Spherical -5.1 4.2 1.76 26.6 14 Spherical -18.8 1.4 - - 15 Spherical -6.6 2.3 1.52 64.2 16 Spherical -29.2 3.0 - - 17 Spherical unlimited - - -

[0164] For each surface in Table 4, surface 1 is the surface of the first spherical lens 1 close to the object plane A, and surface 2 is the surface of the first spherical lens 1 close to the image plane B. Surface 3 is the surface of the second spherical lens 2 close to the object plane A, and surface 4 is the surface of the second spherical lens 2 close to the image plane B. Surface 5 is the surface of the third spherical lens 3 close to the object plane A, and surface 6 is the surface of the third spherical lens 3 close to the image plane B. Surface 7 is the aperture 9, surface 8 is the surface of the super lens 4 close to the object plane A, the micro-nano structure is provided on surface 8, and surface 9 is the surface of the super lens 4 close to the image plane B. Surface 10 is the surface of the fourth spherical lens 5 close to the object plane A, and surface 11 is the surface of the fourth spherical lens 5 close to the image plane B. Surface 12 is the surface of the fifth spherical lens 6 close to the object plane A, surface 13 is the cemented surface of the surface of the fifth spherical lens 6 close to the image plane B and the surface of the sixth spherical lens 7 close to the object plane A, and surface 14 is the surface of the sixth spherical lens 7 close to the image plane B. Surface 15 is the surface of the seventh spherical lens 8 close to the object plane A, and surface 16 is the surface of the seventh spherical lens 8 close to the image plane B. Surface 17 is the image plane.

[0165] Surface 1 is a spherical surface, the radius of curvature of surface 1 is 11.0 mm, and the distance between surface 1 and surface 2 is 2.4 mm. Surface 2 is a spherical surface, the radius of curvature of surface 2 is 27.6 mm, the distance between surface 2 and surface 3 is 0.8 mm, and the material between surface 2 and surface 3 is air. The refractive index of the first spherical lens 1 is 1.80, the Abbe number of the first spherical lens 1 is 46.6, and the material of the first spherical lens 1 is glass.

[0166] Surface 3 is a spherical surface, the radius of curvature of surface 3 is -27.5 mm, and the distance between surface 3 and surface 4 is 1.0 mm. Surface 4 is a spherical surface, the radius of curvature of surface 4 is 8.6 mm, the distance between surface 4 and surface 5 is 2.5 mm, and the material between surface 4 and surface 5 is air. The refractive index of the second spherical lens 2 is 1.65, the Abbe number of the second spherical lens 2 is 33.9, and the material of the second spherical lens 2 is glass.

[0167] Surface 5 is a spherical surface, the radius of curvature of surface 5 is 11.4 mm, and the distance between surface 5 and surface 6 is 2.9 mm. Surface 6 is a spherical surface, the radius of curvature of surface 6 is -27.5 mm, the distance between surface 6 and surface 7 is -0.04 mm, and the material between surface 6 and surface 7 is air. The refractive index of the third spherical lens 3 is 1.91, the Abbe number of the third spherical lens 3 is 35.0, and the material of the third spherical lens 3 is glass.

[0168] The curvature radius of surface 8 is infinite, that is, surface 8 is a plane, and the distance between surface 8 and surface 9 is 0.725 mm. The curvature radius of surface 9 is infinite, that is, surface 9 is a plane, and the distance between surface 9 and surface 10 is 0.16 mm, and the material between surface 9 and surface 10 is air. The equivalent refractive index of superlens 4 is 1.46, the equivalent Abbe number of superlens 4 is 67.8, and the material of superlens 4 is silicon dioxide.

[0169] The surface 10 is a spherical surface, the radius of curvature of the surface 10 is -53.5 mm, and the distance between the surface 10 and the surface 11 is 1.5 mm. The radius of curvature of the surface 11 is 25.6 mm, and the distance between the surface 11 and the surface 12 is 0.1 mm. The refractive index of the fourth spherical lens 5 is 1.62, the Abbe number of the fourth spherical lens 5 is 36.3, and the material of the fourth spherical lens 5 is glass.

[0170] The surface 12 is a spherical surface, the curvature radius of the surface 12 is 17.0 mm, and the distance between the surface 12 and the surface 13 is 3.3 mm. The refractive index of the fifth spherical lens 6 is 1.72, the Abbe number of the fifth spherical lens 6 is 47.9, and the material of the fifth spherical lens 6 is glass.

[0171] Surface 13 is a spherical surface, the radius of curvature of surface 13 is -5.1 mm, and the distance between surface 13 and surface 14 is 4.2 mm. Surface 14 is a spherical surface, the radius of curvature of surface 14 is -18.8 mm, and the distance between surface 14 and surface 15 is 1.4 mm. The refractive index of the sixth spherical lens 7 is 1.76, the Abbe number of the sixth spherical lens 7 is 26.6, and the material of the sixth spherical lens 7 is glass.

[0172] Surface 15 is a spherical surface, the radius of curvature of surface 15 is -6.6 mm, and the distance between surface 15 and surface 16 is 2.3 mm. Surface 16 is a spherical surface, the radius of curvature of surface 16 is -29.2 mm, and the distance between surface 16 and surface 17 is 3.0 mm. The refractive index of the seventh spherical lens 8 is 1.52, the Abbe number of the seventh spherical lens 8 is 64.2, and the material of the seventh spherical lens 8 is glass.

[0173] See also Figure 7 , Figure 7FIG. 2 shows the MTF field curve of the optical system 100 provided in Example 2. Figure 7 The sagittal curve S1 and the meridional curve T1 of the MTF of 120lp / mm spatial frequency as the field of view changes, and the sagittal image curve S2 and the meridional image curve T2 of the MTF of 200lp / mm spatial frequency as the field of view changes are listed. Figure 7 The horizontal axis in is the field of view in the Y-axis direction. Figure 7 The vertical axis in is the MTF value. It can be seen from the above four curves that the MTF of the optical system 100 within the 17.2° (2ω=34.4°) field of view is always greater than 0.45, so the optical system 100 has a good imaging quality.

[0174] See also Figure 8 , Figure 8 The field curvature of the optical system 100 provided in Example 2 under visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns is shown, wherein L1, L2, L3, L4 and L5 are the field curvatures of visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns in the meridional direction, respectively, and L6, L7, L8, L9 and L10 are the field curvatures of visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns in the sagittal direction, respectively. Figure 8 It can be seen that the maximum difference in field curvature of the central field of view is 0.07 mm, and the maximum difference in field curvature of the edge field of view is 0.16 mm, which meets the requirements for field curvature in the excellent imaging quality standard.

[0175] Fig. 9 The distortion of the optical system 100 provided in Example 2 under visible light with wavelengths of 0.435 μm, 0.486 μm, 0.546 μm, 0.587 μm and 0.656 μm is shown ( Fig. 9 A total of five curves are shown in FIG, but the gaps between the five curves are extremely small, resulting in the five curves almost overlapping). Fig. 9 The horizontal axis is the degree of image distortion, and its unit is percentage. Fig. 9 The vertical coordinate is the field of view in the positive direction of the Y axis. Fig. 9 It can be seen that the maximum distortion of the optical system 100 is -2.0%. Therefore, the distortion of the optical system 100 is relatively small, meeting the distortion requirement of the excellent imaging quality standard.

[0176] Fig.10 The vertical axis chromatic aberration of the optical system 100 at wavelengths of 0.587 micron, 0.486 micron, 0.656 micron and 0.435 micron is shown in Example 2, with the position of the visible light with a wavelength of 0.546 micron and the image plane focus as the reference, wherein: Fig.10 The middle curves M1, M2, M3, M4 and M5 represent visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns respectively. Fig.10 It can be seen that the vertical axis chromatic aberration of the optical system 100 is within the range of 1 micron, which meets the requirements of the excellent imaging quality standard for vertical axis chromatic aberration.

[0177] Example 3

[0178] Fig.11 A schematic diagram of the architecture layout of the optical system 100 in Example 3 provided in the present application is shown. In Example 3, the optical system 100 includes, along the optical axis S from the object plane A to the image plane B, a first spherical lens 1, a second spherical lens 2, a third spherical lens 3, a super lens 4, a fourth spherical lens 5, a fifth spherical lens 6, a sixth spherical lens 7 and a seventh spherical lens 8, wherein the fifth spherical lens 6 and the sixth spherical lens 7 are glued together to form a double glued lens.

[0179] Table 5. Some parameters of the optical system 100

[0180] parameter data System volume (TTL) 30mm Field of view (2ω) 34.4° F-number 1.6 Effective focal length 15.14mm Working band Visible light (400nm-700nm)

[0181] As can be seen from Table 5, the optical system 100 in this embodiment has an operating band of 400 nanometers to 700 nanometers, which meets the working requirements of the visible light band. The F number (aperture) of the optical system 100 is 1.6, which can greatly increase the amount of light entering the optical system 100, and collect as much energy as possible entering the optical system 100 when the image sensor has a low response to light energy, thereby ensuring excellent imaging quality. The field of view angle of the optical system 100 is 34.4°. At the same time, the total optical length is only 30 mm, which fully meets the requirements of the optical system 100 for miniaturization and thinness, and is conducive to the control of its volume.

[0182] Starting from the first spherical lens 1 , along the optical axis S from the object plane A to the image plane B, each surface in the optical system 100 is numbered, and the parameters of each surface are summarized to obtain the following Table 6.

[0183] Table 6. Parameters of various surfaces in the optical system 100 provided in Example 3

[0184]

[0185]

[0186] For each surface in Table 6, surface 1 is the surface of the first spherical lens 1 close to the object plane A, and surface 2 is the surface of the first spherical lens 1 close to the image plane B. Surface 3 is the surface of the second spherical lens 2 close to the object plane A, and surface 4 is the surface of the second spherical lens 2 close to the image plane B. Surface 5 is the surface of the third spherical lens 3 close to the object plane A, and surface 6 is the surface of the third spherical lens 3 close to the image plane B. Surface 7 is the aperture 9, surface 8 is the surface of the metalens 4 close to the object plane A, the micro-nano structure is provided on surface 8, and surface 9 is the surface of the metalens 4 close to the image plane B. Surface 10 is the surface of the fourth spherical lens 5 close to the object plane A, and surface 11 is the surface of the fourth spherical lens 5 close to the image plane B. Surface 12 is the surface of the fifth spherical lens 6 close to the object plane A, surface 13 is the cemented surface of the surface of the fifth spherical lens 6 close to the image plane B and the surface of the sixth spherical lens 7 close to the object plane A, and surface 14 is the surface of the sixth spherical lens 7 close to the image plane B. Surface 15 is the surface of the seventh spherical lens 8 close to the object plane A, and surface 16 is the surface of the seventh spherical lens 8 close to the image plane B. Surface 17 is the image plane.

[0187] Surface 1 is a spherical surface, the radius of curvature of surface 1 is 12.6 mm, and the distance between surface 1 and surface 2 is 3.6 mm. Surface 2 is a spherical surface, the radius of curvature of surface 2 is 25.2 mm, the distance between surface 2 and surface 3 is 1.3 mm, and the material between surface 2 and surface 3 is air. The refractive index of the first spherical lens 1 is 1.80, the Abbe number of the first spherical lens 1 is 46.6, and the material of the first spherical lens 1 is glass.

[0188] Surface 3 is a spherical surface, the radius of curvature of surface 3 is -21.8 mm, and the distance between surface 3 and surface 4 is 1.0 mm. Surface 4 is a spherical surface, the radius of curvature of surface 4 is 8.6 mm, the distance between surface 4 and surface 5 is 2.6 mm, and the material between surface 4 and surface 5 is air. The refractive index of the second spherical lens 2 is 1.65, the Abbe number of the second spherical lens 2 is 33.9, and the material of the second spherical lens 2 is glass.

[0189] Surface 5 is a spherical surface, the radius of curvature of surface 5 is 13.1 mm, and the distance between surface 5 and surface 6 is 3.5 mm. Surface 6 is a spherical surface, the radius of curvature of surface 6 is -19.9 mm, the distance between surface 6 and surface 7 is 0.08 mm, and the material between surface 6 and surface 7 is air. The refractive index of the third spherical lens 3 is 1.91, the Abbe number of the third spherical lens 3 is 35.0, and the material of the third spherical lens 3 is glass.

[0190] The curvature radius of surface 8 is infinite, that is, surface 8 is a plane, and the distance between surface 8 and surface 9 is 0.725 mm. The curvature radius of surface 9 is infinite, that is, surface 9 is a plane, and the distance between surface 9 and surface 10 is 0.29 mm, and the material between surface 9 and surface 10 is air. The equivalent refractive index of superlens 4 is 1.46, the equivalent Abbe number of superlens 4 is 67.8, and the material of superlens 4 is silicon dioxide.

[0191] The surface 10 is a spherical surface, the radius of curvature of the surface 10 is -33.7 mm, and the distance between the surface 10 and the surface 11 is 0.8 mm. The radius of curvature of the surface 11 is 50.2 mm, and the distance between the surface 11 and the surface 12 is 0.94 mm. The refractive index of the fourth spherical lens 5 is 1.62, the Abbe number of the fourth spherical lens 5 is 36.3, and the material of the fourth spherical lens 5 is glass.

[0192] The surface 12 is a spherical surface, the curvature radius of the surface 12 is 14.1 mm, and the distance between the surface 12 and the surface 13 is 3.9 mm. The refractive index of the fifth spherical lens 6 is 1.60, the Abbe number of the fifth spherical lens 6 is 68.0, and the material of the fifth spherical lens 6 is glass.

[0193] Surface 13 is a spherical surface, the radius of curvature of surface 13 is -6.0 mm, and the distance between surface 13 and surface 14 is 3.2 mm. Surface 14 is a spherical surface, the radius of curvature of surface 14 is -12.8 mm, and the distance between surface 14 and surface 15 is 3.7 mm. The refractive index of the sixth spherical lens 7 is 1.76, the Abbe number of the sixth spherical lens 7 is 26.6, and the material of the sixth spherical lens 7 is glass.

[0194] Surface 15 is a spherical surface, the radius of curvature of surface 15 is -7.22 mm, and the distance between surface 15 and surface 16 is 1.5 mm. Surface 16 is a spherical surface, the radius of curvature of surface 16 is -30.6 mm, and the distance between surface 16 and surface 17 is 2.9 mm. The refractive index of the seventh spherical lens 8 is 1.60, the Abbe number of the seventh spherical lens 8 is 56.2, and the material of the seventh spherical lens 8 is glass.

[0195] See also Fig.12 , Fig.12 FIG. 2 shows the MTF field curve of the optical system 100 provided in Example 2. Fig.12 The sagittal curve S1 and the meridional curve T1 of the MTF of 120lp / mm spatial frequency as the field of view changes, and the sagittal image curve S2 and the meridional image curve T2 of the MTF of 200lp / mm spatial frequency as the field of view changes are listed. Fig.12 The horizontal axis in is the field of view in the Y-axis direction. Fig.12The vertical axis in is the MTF value. It can be seen from the above four curves that the MTF of the optical system 100 within the 17.2° (2ω=34.4°) field of view is always greater than 0.45, so the optical system 100 has a good imaging quality.

[0196] See also Fig.13 , Fig.13 The field curvature of the optical system 100 provided in Example 3 under visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns is shown, wherein L1, L2, L3, L4 and L5 are the field curvatures of visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns in the meridional direction, respectively, and L6, L7, L8, L9 and L10 are the field curvatures of visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns in the sagittal direction, respectively. Fig.13 It can be seen that the maximum difference in field curvature of the central field of view is 0.06 mm, and the maximum difference in field curvature of the edge field of view is 0.07 mm, which meets the requirements for field curvature in the excellent imaging quality standard.

[0197] Fig.14 The distortion of the optical system 100 provided in Example 3 under visible light with wavelengths of 0.435 μm, 0.486 μm, 0.546 μm, 0.587 μm and 0.656 μm is shown ( Fig.14 A total of five curves are shown in FIG, but the gaps between the five curves are extremely small, resulting in the five curves almost overlapping). Fig.14 The horizontal axis is the degree of image distortion, and its unit is percentage. Fig.14 The vertical coordinate is the field of view in the positive direction of the Y axis. Fig.14 It can be seen that the maximum distortion of the optical system 100 is -2.8%. Therefore, the distortion of the optical system 100 is relatively small, meeting the distortion requirement of the excellent imaging quality standard.

[0198] Fig.15 The vertical axis chromatic aberration of the optical system 100 at wavelengths of 0.587 microns, 0.486 microns, 0.656 microns and 0.435 microns is shown in Example 3, with the position of the visible light with a wavelength of 0.546 microns and the image plane focus as a reference, wherein: Fig.15 The middle curves M1, M2, M3, M4 and M5 represent visible light with wavelengths of 0.435 microns, 0.486 microns, 0.546 microns, 0.587 microns and 0.656 microns respectively. Fig.15 It can be seen that the vertical axis chromatic aberration of the optical system 100 is within the range of 1 micron, which meets the requirements of the excellent imaging quality standard for vertical axis chromatic aberration.

[0199] After summarizing the various parameters of the optical systems provided in the above three embodiments, the following Table 7 is obtained. Table 7 is mainly used to illustrate that the various conditions satisfied by the optical system 100 provided in the present application are all verified and supported by experiments.

[0200] Table 7. Parameters of the optical system 100 provided in various embodiments

[0201]

[0202]

[0203] The present application also provides a vehicle-mounted lens (not shown), which includes an imaging sensor (not shown) and the above-mentioned optical system 100, wherein the structure of the optical system 100 can be found above and will not be described herein. The imaging sensor is disposed on the image plane of the optical system 100, and the imaging sensor 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).

[0204] 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. An optical system, characterized in that: The optical system includes, from the object side to the image side along the optical axis, a first spherical lens, a second spherical lens, a third spherical lens, a super lens, a fourth spherical lens, a fifth spherical lens, a sixth spherical lens and a seventh spherical lens in sequence; the first spherical lens is a positive lens; the second spherical lens is a negative lens; the third spherical lens is a positive lens; the super lens is a positive lens; the surface of the fourth spherical lens away from the object side is convex toward the object side; the fifth spherical lens is a positive lens; the sixth spherical lens is a negative lens; the seventh spherical lens is a negative lens; The fifth spherical lens is at least glued to the sixth spherical lens; any two adjacent lenses satisfy: the lens diameter of the lens close to the object side is greater than or equal to the lens diameter of the lens close to the image side.

2. The optical system according to claim 1, characterized in that The optical system satisfies: Wherein, Δλ is the difference between the maximum working wavelength and the minimum working wavelength of the optical system, is the phase provided by the superlens, and x represents the distance from the center of the superlens along the radial direction of the superlens.

3. The optical system according to claim 1, characterized in that The optical system satisfies: Wherein, n7 is the refractive index of the seventh spherical lens, EXP is the exit pupil diameter of the optical system, and R L2 is the radius of curvature of the surface of the seventh spherical lens close to the image side.

4. The optical system according to claim 1, characterized in that The optical system satisfies: Wherein, the D1 is the aperture of the first spherical lens, the F# is the F number of the optical system, the EPD is the entrance pupil diameter of the optical system, and the FOV is the field of view angle of the optical system.

5. The optical system according to claim 1, characterized in that The optical system satisfies: Among them, the R L1 is the curvature radius of the surface of the seventh spherical lens close to the object side, and the R L2 is the radius of curvature of the surface of the seventh spherical lens close to the image side.

6. The optical system according to claim 1, characterized in that The optical system satisfies: Wherein, the TTL is the total optical length of the optical system, the CT4 is the center thickness of the fourth spherical lens, the CT5 is the center thickness of the fifth spherical lens, and the CT6 is the center thickness of the sixth spherical lens.

7. The optical system according to claim 1, characterized in that The optical system satisfies: Among them, the f m is the focal length of the metalens, and f is the effective focal length of the optical system.

8. The optical system according to claim 1, characterized in that When the fifth spherical lens is only glued to the sixth spherical lens, the optical system satisfies: Wherein, f5 is the focal length of the fifth spherical lens, and v d5 is the Abbe number of the fifth spherical lens, f6 is the focal length of the sixth spherical lens, and v d6 is the Abbe number of the sixth spherical lens.

9. The optical system according to claim 1, characterized in that The fifth spherical lens is also cemented and connected to the fourth spherical lens.

10. The optical system according to claim 9, characterized in that The optical system satisfies: Wherein, f4 is the focal length of the fourth spherical lens, and v d4 is the Abbe number of the fourth spherical lens, f5 is the focal length of the fifth spherical lens, and v d5 is the Abbe number of the fifth spherical lens, f6 is the focal length of the sixth spherical lens, and v d6 is the Abbe number of the sixth spherical lens.

11. The optical system according to any one of claims 1 to 10, characterized in that: The surface of the first spherical lens close to the object side is convex toward the object side, and the surface of the first spherical lens away from the object side is convex toward the object side; the surface of the second spherical lens close to the object side is convex toward the image side, and the surface of the second spherical lens away from the object side is convex toward the object side; the surface of the third spherical lens close to the object side is convex toward the image side, and the surface of the third spherical lens away from the object side is convex toward the image side; the surface of the fourth spherical lens close to the object side is convex toward the object side, and the surface of the fourth spherical lens away from the object side is convex toward the object side; the surface of the fifth spherical lens close to the object side is convex toward the object side, and the surface of the fifth spherical lens away from the object side is convex toward the image side; the surface of the sixth spherical lens close to the object side is convex toward the image side, and the surface of the sixth spherical lens away from the object side is convex toward the image side; the surface of the seventh spherical lens close to the object side is convex toward the image side, and the surface of the seventh spherical lens away from the object side is convex toward the image side; or, The surface of the first spherical lens close to the object side is convex toward the object side, and the surface of the first spherical lens away from the object side is convex toward the object side; the surface of the second spherical lens close to the object side is convex toward the image side, and the surface of the second spherical lens away from the object side is convex toward the object side; the surface of the third spherical lens close to the object side is convex toward the image side, and the surface of the third spherical lens away from the object side is convex toward the image side; the surface of the fourth spherical lens close to the object side is convex toward the image side, and the surface of the fourth spherical lens away from the object side is convex toward the object side; the surface of the fifth spherical lens close to the object side is convex toward the object side, and the surface of the fifth spherical lens away from the object side is convex toward the image side; the surface of the sixth spherical lens close to the object side is convex toward the image side, and the surface of the sixth spherical lens away from the object side is convex toward the image side; the surface of the seventh spherical lens close to the object side is convex toward the image side, and the surface of the seventh spherical lens away from the object side is convex toward the image side.

12. The optical system according to any one of claims 1 to 8, characterized in that: The optical system further includes an aperture, and the aperture is disposed on a surface of the super lens close to the object side, or the aperture is disposed on a surface of the third spherical lens close to the image side.

13. A vehicle-mounted lens, characterized in that: include: An imaging sensor and an optical system as claimed in any one of claims 1 to 12; The imaging sensor is arranged on the image plane of the optical system.

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