High-pixel, large-FOV, small-aperture optical system and head-mounted device

Abstract

The application discloses a high-pixel, large-visual angle and small-caliber optical system and a head-mounted device, which mainly comprises six lenses, the number of lenses is reasonable, the structure is simple, the effective focal length and the optical power of the lenses are reasonably distributed, the imaging quality of the optical system is improved, the optical system has the advantages of high pixels and a large visual angle, meanwhile, the configuration of a large aperture can increase the light quantity of the optical system and the imaging quality is higher, so that the head-mounted optical system has greater competitiveness in the head-mounted device market.

Description

Technical Field

[0001] This application relates to the field of optical imaging, and in particular to a high-pixel, wide-angle, small-aperture optical system for head-mounted optical systems and head-mounted devices for their applications. Background Technology

[0002] With technological advancements and the needs of socio-economic development, virtual reality (VR) technology has developed rapidly, giving rise to head-mounted devices (such as VR glasses). Conventional head-mounted devices, in addition to optical systems that track the user's head, eyes, facial expressions, and hands, also include a see-through optical system. This system enhances the user's perception of their surroundings and improves the device's sustainability. Currently used see-through optical systems have relatively low pixel counts and narrow field of view. Achieving high pixel counts while simultaneously increasing the field of view and expanding the user's field of vision is crucial for user safety and will give the product greater market competitiveness. Summary of the Invention

[0003] To overcome the problems of low pixel count and small field of view that are common in existing optical systems used in head-mounted devices, this application provides a high-pixel, wide-angle, and small-aperture optical system, which has the advantages of high pixel count, wide-angle, and small aperture.

[0004] A high-pixel, wide-angle, small-aperture optical system, consisting of a first lens, a second lens, an aperture stop, a third lens, a fourth lens, a fifth lens, and a sixth lens in sequence along the optical axis from the object plane to the image plane;

[0005] The object-side surface of the first lens is convex, the image-side surface is concave, and its optical power is negative.

[0006] The object-side surface of the third lens is convex, the image-side surface is convex, and its optical power is positive.

[0007] The object-side surface of the fourth lens is convex, and the image-side surface is concave.

[0008] The image-side surface of the fifth lens is convex, and its optical power is positive.

[0009] The optical power of the sixth lens is negative;

[0010] The optical system satisfies the following condition: 1.8 <f*tan(HFOV) / DT11<2.2;

[0011] Where f is the effective focal length of the optical system, HFOV is half of the maximum field of view of the optical system, and DT11 is the maximum effective radius of the object side of the first lens.

[0012] The high-pixel, wide-angle, small-aperture optical system described above satisfies the following relationship: 0.5 < |f1+f2| / |f1-f2| < 2.6;

[0013] 0.9 < |f3-f4| / |f3+f4| < 4.0;

[0014] Where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, and f4 is the effective focal length of the fourth lens.

[0015] The high-pixel, wide-angle, small-aperture optical system described above satisfies the following relationship: 0.3 <f / f4+f / f3<1.3;

[0016] -2.1 <f6 / f<-0.7;

[0017] 1.9 < (f - f12) / f < 3.1;

[0018] Where f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f6 is the effective focal length of the fourth lens, f is the effective focal length of the optical system, and f12 is the effective combined focal length of the first and second lenses.

[0019] The high-pixel, wide-angle, small-aperture optical system described above satisfies the following relationship: 0.9 < |f12 / f23| < 2.4;

[0020] 0.4 <f123 / f234<1.1;

[0021] Where f12 is the effective combined focal length of the first and second lenses, f23 is the effective combined focal length of the second and third lenses, f123 is the effective combined focal length of the first, second and third lenses, and f234 is the effective combined focal length of the second, third and fourth lenses.

[0022] The high-pixel, wide-angle, small-aperture optical system described above satisfies the following relationship: 3.8 < (R1 + R2) / R2 < 6.3;

[0023] 1.6 < (R5 - R6) / R5 < 2.7;

[0024] Wherein, R1 is the radius of curvature of the object side of the first lens, R2 is the radius of curvature of the image side of the first lens, R5 is the radius of curvature of the object side of the third lens, and R6 is the radius of curvature of the image side of the third lens.

[0025] The high-pixel, wide-angle, small-aperture optical system described above satisfies the following relationship: 1.0 <R9 / R12+R10 / R11<2.4;

[0026] Wherein, R9 is the radius of curvature of the object side of the fifth lens, R10 is the radius of curvature of the image side of the fifth lens, R11 is the radius of curvature of the object side of the sixth lens, and R12 is the radius of curvature of the image side of the sixth lens.

[0027] In the high-pixel, wide-angle, small-aperture optical system described above, the maximum effective radius DT11 of the object side of the first lens is ≤2.1; and / or

[0028] The F-number of the optical system is 2.2.

[0029] The high-pixel, wide-angle, small-aperture optical system described above has the following requirements: FOV (field of view) and TTL (total optical length): 105°≤FOV≤112°, TTL≤8.9mm.

[0030] In the high-pixel, wide-angle, small-aperture optical system described above, the first lens is a spherical lens;

[0031] The second, third, fourth, fifth, and sixth lenses are aspherical lenses.

[0032] On the other hand, embodiments of this application also provide a head-mounted device.

[0033] A head-mounted device includes at least an optical lens, the optical lens housing the aforementioned high-pixel, wide-angle, small-aperture optical system.

[0034] Compared with the prior art, the beneficial effects of this application are as follows:

[0035] The optical system and head-mounted device of this invention are mainly composed of 6 lenses. The number of lenses is reasonable and the structure is simple. By reasonably allocating the effective focal length and optical power of the lenses, the imaging quality of the optical system is improved. It has the advantages of high pixel count and wide angle. At the same time, the large aperture configuration can increase the amount of light entering the optical system and achieve higher imaging quality, making the head-mounted optical system more competitive in the head-mounted device market. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0037] Figure 1 This is a schematic diagram of the structure of the optical system or head-mounted device according to Embodiment 1 of this application;

[0038] Figure 2 This is an on-axis chromatic aberration, astigmatism, and distortion curve of the optical system or head-mounted device of Embodiment 1 of this application;

[0039] Figure 3 This is an MTF curve of the optical system or head-mounted device of Embodiment 1 of this application;

[0040] Figure 4 This is a schematic diagram of the structure of the optical system or head-mounted device according to Embodiment 2 of this application;

[0041] Figure 5 This is an on-axis chromatic aberration, astigmatism, and distortion curve of the optical system or head-mounted device of Embodiment 2 of this application;

[0042] Figure 6 This is the MTF curve of the optical system or head-mounted device of Embodiment 2 of this application;

[0043] Figure 7 This is a schematic diagram of the structure of the optical system or head-mounted device according to Embodiment 3 of this application;

[0044] Figure 8 This is an on-axis chromatic aberration, astigmatism, and distortion curve of the optical system or head-mounted device of Embodiment 3 of this application;

[0045] Figure 9 This is an MTF curve of the optical system or head-mounted device of Embodiment 3 of this application;

[0046] Figure 10 This is a schematic diagram of the structure of the optical system or head-mounted device according to Embodiment 4 of this application;

[0047] Figure 11 This is an on-axis chromatic aberration, astigmatism, and distortion curve of the optical system or head-mounted device of Embodiment 4 of this application;

[0048] Figure 12 This is the MTF curve of the optical system or head-mounted device of Embodiment 4 of this application;

[0049] Figure 13 This is a schematic diagram of the structure of the optical system or head-mounted device according to Embodiment 5 of this application;

[0050] Figure 14 This is an on-axis chromatic aberration, astigmatism, and distortion curve of the optical system or head-mounted device of Embodiment 5 of this application;

[0051] Figure 15 This is the MTF curve of the optical system or head-mounted device of Embodiment 5 of this application. Detailed Implementation

[0052] like Figure 1-15 As shown, a high-pixel, wide-angle, small-aperture optical system is composed of a first lens E1, a second lens E2, an aperture stop STO, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and an infrared filter E7, arranged sequentially from the object plane to the image plane along the optical axis.

[0053] The object side of the first lens E1 is convex, and the image side is concave, and its optical power is negative;

[0054] The object side of the third lens E3 is convex, and the image side is convex, and its optical power is positive;

[0055] The object side of the fourth lens E4 is convex, and the image side is concave;

[0056] The image side of the fifth lens E5 is convex, and its optical power is positive;

[0057] The optical power of the sixth lens E6 is negative;

[0058] The optical system of the embodiment of the present invention mainly consists of six lenses. The number of lenses is reasonable and the structure is simple. By reasonably distributing the effective focal length and optical power of the optical imaging system, the size of the system can be effectively compressed, the characteristics of a large wide angle can be realized, and it has the advantages of high pixels, large wide angle and small aperture. It can increase the light input of the optical system and higher imaging quality, making the head-mounted optical system more competitive in the head-mounted device market.

[0059] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following condition: 1.8 < f * tan(HFOV) / DT11 < 2.2; where f is the effective focal length of the optical system, HFOV is half of the maximum field angle of the optical system, and DT11 is the maximum effective radius of the object side of the first lens E1. By reasonably distributing the effective focal length of the optical imaging system, half of the maximum field angle of the optical imaging system, and the maximum effective radius of the object side of the first lens E1, the size of the system can be effectively compressed, and the characteristics of a large wide angle can be realized.

[0060] Further, as a preferred embodiment of the present invention rather than a limitation, the effective focal length f1 of the first lens E1 and the effective focal length f2 of the second lens E2 satisfy: 0.5 < |f1 + f2| / |f1 - f2| < 2.6. By reasonably controlling the focal length ratio of the first lens E1 and the second lens E2, the optical system can satisfy the large field angle range and at the same time obtain a high imaging resolution. Exceeding the upper limit of the relationship, the refractive power of the first lens E1 and the second lens E2 is insufficient, and it is difficult for large-angle light rays to enter the optical system, which is not conducive to expanding the field angle range of the optical system; below the lower limit of the relationship, the refractive power of the first lens E1 and the second lens E2 is too strong, and strong astigmatism and chromatic aberration are easily generated, which is not conducive to the high-resolution imaging characteristics.

[0061] Furthermore, as a preferred embodiment of the present invention rather than a limitation, the effective focal length f3 of the third lens E3 and the effective focal length f4 of the fourth lens E4 satisfy: 0.9 < |f3 - f4| / |f3 + f4| < 4.0. By limiting the effective focal lengths of the third lens E3 and the fourth lens E4 of the optical imaging system within a reasonable range, the contributions of spherical aberration and coma of the third lens E3 and the fourth lens E4 can be effectively constrained, and after balancing, their sensitivity can be kept at a reasonable level.

[0062] Furthermore, as a preferred embodiment of the present invention rather than a limitation, the effective focal length f3 of the third lens E3, the effective focal length f4 of the fourth lens E4, and the effective focal length f of the optical system satisfy: 0.3 < f / f4 + f / f3 < 1.3. By reasonably controlling the range of the above formula, reasonable positive third-order spherical aberration and negative fifth-order spherical aberration can be contributed, balancing the negative third-order spherical aberration and positive fifth-order spherical aberration generated by the third lens E3 and the fourth lens E4, so that the system has smaller spherical aberration and ensures good imaging quality of the on-axis field.

[0063] Furthermore, as a preferred embodiment of the present invention rather than a limitation, the effective focal length f6 of the fourth lens E4 and the effective focal length f of the optical system satisfy: -2.1 < f6 / f < -0.7. By constraining the ratio of the optical power of the sixth lens E6 to the effective focal length of the optical imaging system within a reasonable range, the remaining spherical aberration after balancing can be used to balance the spherical aberration generated by the first five lenses, thereby finely adjusting and controlling the spherical aberration of the system and strengthening the precise control of the aberration of the on-axis field.

[0064] Furthermore, as a preferred embodiment of the present invention rather than a limitation, the effective focal length f of the optical system and the effective combined focal length f12 of the first lens E1 and the second lens E2 satisfy: 1.9 < (f - f12) / f < 3.1. The first lens E1 provides negative refractive power for the optical system, and the sixth lens E6 provides positive or negative refractive power for the optical system. By using two lenses with positive and negative refractive powers, it is beneficial to the mutual correction of aberrations. Exceeding the upper limit of the relationship, the refractive power of the lens combination is too small, which is likely to generate large marginal aberrations and chromatic aberrations, and is not conducive to improving the resolution performance; exceeding the lower limit of the relationship, the overall refractive power of the first lens E1 and the second lens E2 is too strong, making the lens group prone to serious astigmatism, which is not conducive to the improvement of imaging quality.

[0065] Further, as a preferred embodiment of the present invention rather than a limitation, the effective combined focal length f12 of the first lens E1 and the second lens E2, and the effective combined focal length f23 of the second lens E2 and the third lens E3 satisfy: 0.9 < |f12 / f23| < 2.4. By defining the ratio range of the combined focal length of the first lens E1 and the second lens E2 and the combined focal length of the second lens E2 and the third lens E3, it not only ensures excellent image quality of the optical system but also ensures good processability of the system.

[0066] Further, as a preferred embodiment of the present invention rather than a limitation, the effective combined focal length f123 of the first lens E1, the second lens E2 and the third lens E3, and the effective combined focal length f234 of the second lens E2, the third lens E3 and the fourth lens E4 satisfy: 0.4 < f123 / f234 < 1.1. Satisfying the above relationship is conducive to the transmission of a large-angle light beam through and into the aperture STO, realizing the wide-angleization of the optical system and being conducive to the improvement of the image plane brightness of the large-angle field of view. Exceeding the upper limit of the relationship, the bending force of the front lens group is too strong, and serious astigmatism is likely to occur in the large-angle marginal field of view, reducing the marginal resolution; below the lower limit of the relationship, the bending force of the front lens group is insufficient, which is not conducive to the wide-angleization of the optical system.

[0067] Further, as a preferred embodiment of the present invention rather than a limitation, the curvature radius R1 of the object side of the first lens E1 and the curvature radius R2 of the image side of the first lens E1 satisfy: 3.8 < (R1 + R2) / R2 < 6.3. By controlling the curvature radii of the object side and the image side of the first lens E1, the total deflection angles of the object side and the image side of the first lens E1 at the marginal field of view can be reasonably controlled within a reasonable range, and the sensitivity of the system can be effectively reduced.

[0068] Further, as a preferred embodiment of the present invention rather than a limitation, the curvature radius R5 of the object side of the third lens E3 and the curvature radius R6 of the image side of the third lens E3 satisfy: 1.6 < (R5 - R6) / R5 < 2.7. By defining the ratio range of the curvature radii of the object side and the image side of the third lens E3, the shape of the third lens E3 can be effectively constrained, and then the aberration contribution rates of the object side and the image side surfaces of the third lens E3 can be effectively controlled to effectively balance the aberration related to the aperture band of the system, and further effectively improve the imaging quality of the system.

[0069] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following relationship: 1.0 < R9 / R12 + R10 / R11 < 2.4; where R9 is the curvature radius of the object side surface of the fifth lens E5, R10 is the curvature radius of the image side surface of the fifth lens E5, R11 is the curvature radius of the object side surface of the sixth lens E6, and R12 is the curvature radius of the image side surface of the sixth lens E6. By controlling the curvature radii of the object side and image side of the fifth lens E5 and the sixth lens E6 within a reasonable range, the contributions of the astigmatism on the object side and image side surfaces can be effectively controlled, and thus the image quality in the intermediate field of view and aperture band can be effectively and reasonably controlled.

[0070] Further, as a preferred embodiment of the present invention rather than a limitation, the maximum effective radius DT11 of the object side surface of the first lens E1 ≤ 2.1, with a simple structure, can effectively compress the size of the system and achieve the characteristics of a large wide angle.

[0071] Further, as a preferred embodiment of the present invention rather than a limitation, the F number of the optical system is 2.2, with a compact structure, facilitating processing and installation. At the same time, the configuration of a large aperture can increase the light input of the optical system and provide higher imaging quality, making the head-mounted optical system more competitive in the market.

[0072] Further, as a preferred embodiment of the present invention rather than a limitation, the full field of view FOV of the optical system satisfies: 105° ≤ FOV ≤ 112°, which can enable the optical system to meet the requirement of a large field of view.

[0073] Further, as a preferred embodiment of the present invention rather than a limitation, the total optical length TTL of the optical system satisfies: TTL ≤ 8.9 mm. This design can reduce the total optical length and effectively miniaturize the lens of the head-mounted optical system configured in the present invention.

[0074] Further, as a preferred embodiment of the present invention rather than a limitation, the first lens E1 is a spherical lens; the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, and the sixth lens E6 are aspherical lenses, having the advantages of high pixels, large wide angle, and small aperture. At the same time, the configuration of a large aperture can increase the light input of the optical system and provide higher imaging quality.

[0075] Specifically, as a preferred embodiment of the present invention rather than a limitation, as Figure 1-3 shown in Embodiment 1, it sequentially includes, along the optical axis from the object side to the image side: a first lens E1, a second lens E2, a STO, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, an infrared filter E7, and an imaging surface S15.

[0076] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0077] In this embodiment 1, the focal length of the first lens E1 is f1 = -3.30mm, the focal length of the second lens E2 is f2 = 11.13mm, the focal length of the third lens E3 is f3 = 3.01mm, the focal length of the fourth lens E4 is f4 = -5.06mm, the focal length of the fifth lens E5 is f5 = 3.95mm, the focal length of the sixth lens E6 is f6 = -5.87mm, the lens focal length is f = 2.90mm, the total optical length TTL = 8.87mm, ImgH = 2.85mm, HFOV = 52.55°, and f / EPD = 2.20. The surface type, radius of curvature, thickness, and material parameters of each lens are shown in Table 1.

[0078] Table 1: Basic parameters of the optical system in Example 1

[0079] Face number Surface type Radius of curvature (mm) Thickness (mm) Material OBJ spherical endless 2000 S1 spherical 4.9431 0.8478 1.91,35.25 S2 spherical 1.7219 0.9661 S3 aspherical -7.6241 0.6308 1.66,20.38 S4 aspherical -3.8925 0.6647 STO spherical endless -0.1324 S5 aspherical 4.0469 0.9832 1.54,55.77 S6 aspherical -2.4616 0.0300 S7 aspherical 4.8831 0.6086 1.66,20.38 S8 aspherical 1.8995 0.1499 S9 aspherical 3.9183 1.0000 1.54,55.77 S10 aspherical -4.2279 1.1814 S11 aspherical 7.1764 0.7386 1.66,20.38 S12 aspherical 2.4325 0.1906 S13 spherical endless 0.2100 1.52,64.17 S14 spherical endless 0.8012 S15 spherical endless

[0080] Furthermore, in Table 1, the object-side surface and image-side surface of any one of the second lens E2 to the sixth lens E6 are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0081]

[0082] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 2 gives the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for each aspherical surface that can be used in the first embodiment.

[0083] Table 2: Aspherical correlation values ​​of the lens surface in Example 1

[0084]

[0085] Figure 2The on-axis chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 1 are shown. On-axis chromatic aberration represents the deviation of the focal point of light of different wavelengths after passing through the lens; astigmatism represents the curvature of the meridional image plane and the sagittal image plane; distortion represents the magnitude of distortion corresponding to different image heights.

[0086] Figure 3 The MTF curve of the optical imaging lens of Example 1 is shown, which represents the MTF values ​​in the meridional and sagittal directions of different fields of view at different spatial frequencies.

[0087] Depend on Figure 2 and Figure 3 It can be seen that the optical imaging system given in Example 1 can achieve good imaging quality and has the advantages of high pixel count, wide angle and small aperture.

[0088] Specifically, this is a preferred embodiment of the invention and not a limitation thereof, such as Figure 4-6 As shown in Example 2, the optical axis includes, in sequence from the object side to the image side: a first lens E1, a second lens E2, a STO, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, an infrared filter E7, and an imaging surface S15.

[0089] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0090] In this embodiment 2, the focal length of the first lens E1 is f1 = -4.44mm, the focal length of the second lens E2 is f2 = -100.00mm, the focal length of the third lens E3 is f3 = 2.93mm, the focal length of the fourth lens E4 is f4 = -8.00mm, the focal length of the fifth lens E5 is f5 = 3.69mm, the focal length of the sixth lens E6 is f6 = -3.50mm, the lens focal length is f = 3.14mm, the total optical length TTL = 8.64mm, ImgH = 2.85mm, HFOV = 52.53°, and f / EPD = 2.20. The surface type, radius of curvature, thickness, and material parameters of each lens are shown in Table 3.

[0091] Table 3: Basic parameters of the optical system in Example 2

[0092] Face number Surface type Radius of curvature (mm) Thickness (mm) Material OBJ spherical endless 2000 S1 spherical 7.4389 0.8588 1.91,35.25 S2 spherical 2.4866 0.7665 S3 aspherical -8.1432 1.1471 1.66,20.38 S4 aspherical -9.7954 0.4589 STO spherical endless -0.2244 S5 aspherical 2.9770 0.8575 1.54,55.77 S6 aspherical -3.0108 0.2733 S7 aspherical 2.6565 0.4409 1.66,20.38 S8 aspherical 1.6571 0.2210 S9 aspherical 4.5128 0.9261 1.54,55.77 S10 aspherical -3.2827 1.1080 S11 aspherical -5.9631 0.7477 1.66,20.38 S12 aspherical 4.0416 0.1511 S13 spherical endless 0.2100 1.52,64.17 S14 spherical endless 0.7001 S15 spherical endless

[0093] Furthermore, in Table 3, the object-side surface and image-side surface of any one of the second lens E2 to the sixth lens E6 are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0094]

[0095] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 4 gives the conic coefficients and higher-order term coefficients A4, A6, A8, A10, A12, A14, and A16 that can be used for each aspherical surface in the first embodiment.

[0096] Table 4: Aspherical correlation values ​​of the lens surface in Example 2

[0097]

[0098] Figure 5 The on-axis chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 2 are shown. On-axis chromatic aberration represents the deviation of the focal point of light of different wavelengths after passing through the lens; astigmatism represents the curvature of the meridional image plane and the sagittal image plane; distortion represents the magnitude of distortion corresponding to different image heights.

[0099] Figure 6 The MTF curve of the optical imaging lens of Example 2 is shown, which represents the MTF values ​​in the meridional and sagittal directions of different fields of view at different spatial frequencies.

[0100] Depend on Figure 5 and Figure 6 It can be seen that the optical imaging system given in Example 2 can achieve good imaging quality and has the advantages of high pixel count, wide angle and small aperture.

[0101] Specifically, this is a preferred embodiment of the invention and not a limitation thereof, such as Figure 7-9 As shown in Example 3, the optical structure includes, in sequence from the object side to the image side, the following elements: first lens E1, second lens E2, STO, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, infrared filter E7, and imaging surface S15.

[0102] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being concave and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0103] In this embodiment 3, the focal length of the first lens E1 is f1 = -5.35mm, the focal length of the second lens E2 is f2 = -12.25mm, the focal length of the third lens E3 is f3 = 3.06mm, the focal length of the fourth lens E4 is f4 = 400.00mm, the focal length of the fifth lens E5 is f5 = 3.45mm, the focal length of the sixth lens E6 is f6 = -2.58mm, the lens focal length is f = 3.27mm, the total optical length TTL = 8.51mm, ImgH = 2.85mm, HFOV = 52.73°, and f / EPD = 2.20. The surface type, radius of curvature, thickness, and material parameters of each lens are shown in Table 5.

[0104] Table 5: Basic parameters of the optical system in Example 3

[0105] Face number Surface type Radius of curvature (mm) Thickness (mm) Material OBJ spherical endless 2000 S1 spherical 9.3523 0.8682 1.91,35.25 S2 spherical 3.0766 0.6150 S3 aspherical -18.2922 1.3898 1.66,20.38 S4 aspherical 15.2977 0.2370 STO spherical endless -0.2070 S5 aspherical 2.5168 0.8410 1.54,55.77 S6 aspherical -4.1947 0.4911 S7 aspherical 2.0794 0.4265 1.66,20.38 S8 aspherical 1.9234 0.2630 S9 aspherical 6.1444 1.0776 1.54,55.77 S10 aspherical -2.4871 1.0526 S11 aspherical -2.4275 0.4267 1.66,20.38 S12 aspherical 6.4068 0.1388 S13 spherical endless 0.2100 1.52,64.17 S14 spherical endless 0.6748 S15 spherical endless

[0106] Furthermore, in Table 5, the object-side surface and image-side surface of any one of the second lens E2 to the sixth lens E6 are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0107]

[0108] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 6 gives the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for each aspherical surface that can be used in the first embodiment.

[0109] Table 6: Aspherical Correlation Values ​​of Lens Surface in Example 3

[0110]

[0111] Figure 8The on-axis chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 3 are shown. On-axis chromatic aberration represents the deviation of the focal point of light of different wavelengths after passing through the lens; astigmatism represents the curvature of the meridional image plane and the sagittal image plane; distortion represents the magnitude of distortion corresponding to different image heights.

[0112] Figure 9 The MTF curve of the optical imaging lens of Example 3 is shown, which represents the MTF values ​​in the meridional and sagittal directions of different fields of view at different spatial frequencies.

[0113] Depend on Figure 8 and Figure 9 It can be seen that the optical imaging system given in Example 3 can achieve good imaging quality and has the advantages of high pixel count, wide angle and small aperture.

[0114] Specifically, this is a preferred embodiment of the invention and not a limitation thereof, such as Figure 10-12 As shown in Example 4, the following components are arranged sequentially from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a STO, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, an infrared filter E7, and an imaging surface S15.

[0115] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being convex. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0116] In this embodiment 4, the focal length of the first lens E1 is f1 = -4.74mm, the focal length of the second lens E2 is f2 = -14.53mm, the focal length of the third lens E3 is f3 = 2.72mm, the focal length of the fourth lens E4 is f4 = 400.00mm, the focal length of the fifth lens E5 is f5 = 4.27mm, the focal length of the sixth lens E6 is f6 = -2.59mm, the lens focal length is f = 3.35mm, the total optical length TTL = 8.68mm, ImgH = 2.85mm, HFOV = 53.03°, and f / EPD = 2.20. The surface type, radius of curvature, thickness, and material parameters of each lens are shown in Table 7.

[0117] Table 7: Basic parameters of the optical system in Example 4

[0118] Face number Surface type Radius of curvature (mm) Thickness (mm) Material OBJ spherical endless 2000 S1 spherical 18.1204 0.7528 1.91,35.25 S2 spherical 3.4362 0.6962 S3 aspherical 99.9525 1.5200 1.66,20.38 S4 aspherical 8.8045 0.2910 STO spherical endless -0.2610 S5 aspherical 2.2998 0.9477 1.54,55.77 S6 aspherical -3.4436 0.4072 S7 aspherical 2.3053 0.4000 1.66,20.38 S8 aspherical 2.1636 0.3838 S9 aspherical -100.0000 0.9305 1.54,55.77 S10 aspherical -2.2526 1.2157 S11 aspherical -1.7000 0.4000 1.66,20.38 S12 aspherical -100.0000 0.1371 S13 spherical endless 0.2100 1.52,64.17 S14 spherical endless 0.6510 S15 spherical endless

[0119] Furthermore, in Table 7, the object-side surface and image-side surface of any one of the second lens E2 to the sixth lens E6 are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0120]

[0121] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 8 gives the conic coefficients and higher-order term coefficients A4, A6, A8, A10, A12, A14, and A16 for each aspherical surface that can be used in the first embodiment.

[0122] Table 8: Aspherical Correlation Values ​​of Lens Surface in Example 4

[0123]

[0124] Figure 11 The on-axis chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 4 are shown. On-axis chromatic aberration represents the deviation of the focal point of light of different wavelengths after passing through the lens; astigmatism represents the curvature of the meridional image plane and the sagittal image plane; distortion represents the magnitude of distortion corresponding to different image heights.

[0125] Figure 12 The MTF curve of the optical imaging lens of Example 4 is shown, which represents the MTF values ​​in the meridional and sagittal directions of different fields of view at different spatial frequencies.

[0126] Depend on Figure 11 and Figure 12 It can be seen that the optical imaging system given in Example 4 can achieve good imaging quality and has the advantages of high pixel count, wide angle and small aperture.

[0127] Specifically, this is a preferred embodiment of the invention and not a limitation thereof, such as Figure 13-15 As shown in Example 5, the optical axis includes, in sequence from the object side to the image side: a first lens E1, a second lens E2, a STO, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, an infrared filter E7, and an imaging surface S15.

[0128] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0129] In this embodiment 5, the focal length of the first lens E1 is f1 = -3.75mm, the focal length of the second lens E2 is f2 = -19.88mm, the focal length of the third lens E3 is f3 = 2.83mm, the focal length of the fourth lens E4 is f4 = -5.90mm, the focal length of the fifth lens E5 is f5 = 3.80mm, the focal length of the sixth lens E6 is f6 = -3.71mm, the lens focal length is f = 2.97mm, the total optical length TTL = 8.54mm, ImgH = 2.85mm, HFOV = 55.71°, and f / EPD = 2.20. The surface type, radius of curvature, thickness, and material parameters of each lens are shown in Table 9.

[0130] Table 9: Basic Parameters of the Optical System in Example 5

[0131] Face number Surface type Radius of curvature (mm) Thickness (mm) Material OBJ spherical endless 2000 S1 spherical 9.5240 0.7643 1.91,35.25 S2 spherical 2.4301 0.7846 S3 aspherical -11.8325 1.0370 1.66,20.38 S4 aspherical -6.4816 0.5537 STO spherical endless -0.2034 S5 aspherical 3.4856 0.8982 1.54,55.77 S6 aspherical -2.4580 0.0471 S7 aspherical 3.0670 0.5423 1.66,20.38 S8 aspherical 1.6032 0.2364 S9 aspherical 5.4677 0.9180 1.54,55.77 S10 aspherical -3.0662 1.0630 S11 aspherical -8.4053 0.8198 1.66,20.38 S12 aspherical 3.6617 0.1606 S13 spherical endless 0.2100 1.52,64.17 S14 spherical endless 0.7064 S15 spherical endless

[0132] Furthermore, in Table 9, the object-side surface and image-side surface of any one of the second lens E2 to the sixth lens E6 are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0133]

[0134] Where x is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula. Table 10 gives the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for each aspherical surface that can be used in the first embodiment.

[0135] Table 10: Aspherical Correlation Values ​​of Lens Surface in Example 5

[0136]

[0137] Figure 14The on-axis chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 5 are shown. On-axis chromatic aberration represents the deviation of the focal point of light of different wavelengths after passing through the lens; astigmatism represents the curvature of the meridional image plane and the sagittal image plane; distortion represents the magnitude of distortion corresponding to different image heights.

[0138] Figure 15 The MTF curve of the optical imaging lens of Example 5 is shown, which represents the MTF values ​​in the meridional and sagittal directions of different fields of view at different spatial frequencies.

[0139] Depend on Figure 14 and Figure 15 It can be seen that the optical imaging system given in Example 5 can achieve good imaging quality and has the advantages of high pixel count, wide angle and small aperture.

[0140] Furthermore, in Examples 1-5, the basic data is shown in Table 11:

[0141] Table 11: Basic Data for Examples 1-5

[0142] Basic data Example 1 Example 2 Example 3 Example 4 Example 5 f1(mm) -3.30 -4.44 -5.35 -4.74 -3.75 f2 (mm) 11.13 -100.00 -12.25 -14.53 19.88 f3 (mm) 3.01 2.93 3.06 2.72 2.83 f4 (mm) -5.06 -8.00 400.00 400.00 -5.90 f5 (mm) 3.95 3.69 3.45 4.27 3.80 f6 (mm) -5.87 -3.50 -2.58 -2.59 -3.71 f(mm) 2.90 3.14 3.27 3.35 2.97 TTL(mm) 8.87 8.64 8.51 8.68 8.54 ImgH(mm) 2.85 2.85 2.85 2.85 2.85 HFOV (°) 52.55 52.53 52.73 53.03 55.71 f / EPD 2.20 2.20 2.20 2.20 2.20

[0143] In further embodiments 1-5, each conditional expression satisfies the conditions in Table 12 below:

[0144] Table 12: Conditions for Each Example 1-5

[0145] Conditional expression Example 1 Example 2 Example 3 Example 4 Example 5 R1 4.94 7.44 9.35 18.12 9.52 R2 1.72 2.49 3.08 3.44 2.43 R5 4.05 2.98 2.52 2.30 3.49 R6 -2.46 -3.01 -4.19 -3.44 -2.46 R9 3.92 4.51 6.14 -100.00 5.47 R10 -4.23 -3.28 -2.49 -2.25 -3.07 R11 7.18 -5.96 -2.43 -1.70 -8.41 R12 2.43 4.04 6.41 -100.00 3.66 f12 -5.72 -4.43 -3.56 -3.30 -5.25 f23 2.47 2.84 3.82 3.29 2.48 f123 2.99 3.70 6.55 4.73 2.91 f234 3.42 3.55 3.49 3.05 3.24 DT11 2.10 2.10 2.10 2.10 2.10 f*tan(HFOV) / DT11 1.80 1.95 2.05 2.12 2.07 |f1+f2| / |f1-f2| 0.54 1.09 2.55 1.97 0.68 |f3-f4| / |f3+f4| 3.93 2.16 0.98 0.99 2.85 f / f4+f / f3 0.39 0.68 1.08 1.24 0.54 f6 / f -2.02 -1.11 -0.79 -0.77 -1.25 (f-f12) / f 2.97 2.41 2.09 1.98 2.77 |f12 / f23| 2.32 1.56 0.93 1.00 2.12 f123 / f234 0.87 1.04 1.88 1.55 0.90 (R1+R2) / R2 3.87 3.99 4.04 6.27 4.92 (R5-R6) / R5 1.61 2.01 2.67 2.50 1.71 R9 / R12+R10 / R11 1.02 1.67 1.98 2.33 1.86

[0146] A head-mounted device includes at least an optical lens, within which is installed the aforementioned high-pixel, wide-angle, small-aperture optical system. The head-mounted optical system configured in this invention has the advantages of high pixel count, wide-angle, and small aperture, and has a compact structure, making it easy to manufacture and install. At the same time, the large aperture configuration can increase the amount of light entering the optical system and achieve higher image quality, making the head-mounted optical system more competitive in the head-mounted device market.

[0147] The above description provides one or more embodiments in conjunction with specific content, and does not imply that the specific implementation of the present invention is limited to these descriptions. Any methods or structures that are similar to or identical to those of the present invention, or any technical deductions or substitutions made based on the concept of the present invention, should be considered within the scope of protection of the present invention.

Claims

1. A high-pixel, large-FOV, small-aperture optical system, sequentially comprising a first lens, a second lens, a stop, a third lens, a fourth lens, a fifth lens and a sixth lens along an optical axis from an object plane to an image plane, characterized in that: the first lens has a convex object side and a concave image side, and has a negative power; the third lens has a convex object side and a convex image side, and has a positive power; the fourth lens has a convex object side and a concave image side; the fifth lens has a convex image side, and has a positive power; the sixth lens has a negative power; the optical system satisfies the following conditions: 1.8 < f*tan (HFOV) / DT11 < 2.2; wherein f is an effective focal length of the optical system, HFOV is half of a maximum field of view angle of the optical system, and DT11 is a maximum effective radius of the object side of the first lens; the optical system satisfies the following relationships: 0.5 < |f1+f2| / |f1-f2| < 2.6; 0.9 < |f3-f4| / |f3+f4| < 4.0; wherein f1 is an effective focal length of the first lens, f2 is an effective focal length of the second lens, f3 is an effective focal length of the third lens, and f4 is an effective focal length of the fourth lens; the optical system satisfies the following relationships: 0.3 < f / f4+f / f3 < 1.3; -2.1 < f6 / f < -0.7; 1.9 < (f-f12) / f < 3.1; wherein f3 is an effective focal length of the third lens, f4 is an effective focal length of the fourth lens, f6 is an effective focal length of the fourth lens, f is an effective focal length of the optical system, and f12 is an effective combined focal length of the first lens and the second lens; the optical system satisfies the following relationships: 0.9 < |f12 / f23| < 2.4; 0.4 < f123 / f234 < 1.1; wherein f12 is an effective combined focal length of the first lens and the second lens, f23 is an effective combined focal length of the second lens and the third lens, f123 is an effective combined focal length of the first lens, the second lens and the third lens, and f234 is an effective combined focal length of the second lens, the third lens and the fourth lens; the optical system satisfies the following relationships: 3.8 < (R1+R2) / R2 < 6.3; 1.6 < (R5-R6) / R5 < 2.7; wherein R1 is a curvature radius of the object side of the first lens, R2 is a curvature radius of the image side of the first lens, R5 is a curvature radius of the object side of the third lens, and R6 is a curvature radius of the image side of the third lens; the optical system satisfies the following relationships: 1.0 < R9 / R12+R10 / R11 < 2.4; wherein R9 is a curvature radius of the object side of the fifth lens, R10 is a curvature radius of the image side of the fifth lens, R11 is a curvature radius of the object side of the sixth lens, and R12 is a curvature radius of the image side of the sixth lens; a maximum effective radius DT11 of the object side of the first lens is less than or equal to 2.1; and / or an F number of the optical system is 2.2; a full field of view angle FOV and a total track length TTL of the optical system satisfy 105° ≤ FOV ≤ 112° and TTL ≤ 8.9 mm. ​ ​ ​ ​ ​ ​ ​ ​ 2. The high-pixel, large-aperture, small-diameter optical system according to claim 1, characterized by, ​ ​ ​ ​ 3. The high-pixel, large-aperture, small-diameter optical system according to claim 1, characterized by, ​ ​ ​ ​ ​ 4. The high-pixel, large-aperture, small-diameter optical system according to claim 1, characterized by, ​ ​ ​ ​ 5. The high-pixel, large-aperture, small-diameter optical system according to any one of claims 1 to 4, characterized by, ​ ​ ​ ​ 6. The high-pixel, large-aperture, small-diameter optical system according to any one of claims 1 to 4, characterized by, ​ ​ ​ 7. The high-pixel, large-aperture, small-diameter optical system according to any one of claims 1 to 4, characterized by, ​ ​ 8. The high-pixel, large-aperture, small-diameter optical system according to any one of claims 1 to 4, characterized by, ​ 9. The high-pixel, large-aperture, small-diameter optical system according to any one of claims 1 to 4, characterized by, The first lens is a spherical lens. The second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are aspherical lenses.

10. A head-mounted device comprising at least an optical lens, characterized in that, The optical lens is installed with the high-pixel, wide-angle and small-diameter optical system according to any one of claims 1-9.

Images