A high-pixel, wide-angle, compact optical system and head-mounted device

Abstract

The present invention discloses a high-pixel, wide-angle, compact optical system and head-mounted device, which are mainly composed of 6 lenses. The number of lenses is reasonable and the structure is simple. By reasonably allocating the effective focal length of the optical imaging lens, the on-axis distance from the object side of the first lens E1 to the imaging surface, and the ratio of half the diagonal length of the effective pixel area on the imaging surface, the light deflection angle is small, which can effectively reduce the sensitivity of the optical imaging lens, and can achieve ultra-thin, high-pixel and wide-angle optical imaging lenses. It can also be easily injection-molded and have a high assembly yield. The structure is compact and has good imaging quality, making the see-through optical system more competitive in the head-mounted device market.

Description

Technical Field

[0001] The present application relates to the field of optical imaging, and in particular to a high-pixel, wide-angle, compact optical system for use in a see-through optical system and a head-mounted device thereof. Background Art

[0002] With the development of computer technology, various wearable devices have emerged. Devices such as AR (Augmented Reality), VR (Virtual Reality), MR (Mediated Reality), and XR are gaining increasing attention. Existing head-mounted devices are equipped with optical systems with see-through functions, which allow users to see the real environment of the surrounding boundary area without removing the wearable device. The currently used see-through optical systems have low pixel count and a small field of view. How to achieve high pixel count while increasing the field of view of the optical system and expanding the range that users can see is extremely important for user safety and can make the product more competitive in the market. Summary of the Invention

[0003] In order to overcome the common problems of low pixels and small field of view in existing see-through optical systems, the present application provides a high-pixel, wide-angle, compact optical system with the advantages of high pixels and wide angle, and good imaging quality.

[0004] A high-pixel, wide-angle, compact optical system, which consists of a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens, and a sixth lens 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 and image-side surface of the third lens are 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 has positive optical power;

[0009] The image side surface of the sixth lens is concave and has negative optical power;

[0010] The optical system meets the following conditions:

[0011] 2.2 <f / EPD<2.5;

[0012] 1.2 <f / TTL*ImagH<1.5;

[0013] Wherein, f is the effective focal length of the optical system, EPD is the entrance pupil diameter of the optical system, TTL is the on-axis distance from the object side of the first lens to the imaging surface, and ImgH is half the diagonal length of the effective pixel area on the imaging surface.

[0014] The high-pixel, wide-angle, compact optical system described above satisfies the following relationship:

[0015] 3.2 <f5 / |(f5+f6)|<6.2;

[0016] 2.3<|(f3-f1) / f3|<3.1;

[0017] 1.8<(f5-f6) / f<3.0;

[0018] Wherein, f1 is the effective focal length of the first lens, f3 is the effective focal length of the third lens, f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f is the effective focal length of the optical system.

[0019] The high-pixel, wide-angle, compact optical system described above satisfies the following relationship:

[0020] The optical system satisfies the following relationship:

[0021] 2.7<(R1+R2) / R2<3.6;

[0022] 1.5<(R5-R6) / R7<2.8;

[0023] 3.4 <R12+|R10 / R11|<6.4;

[0024] Among them, R1 is the curvature radius of the object side of the first lens, R2 is the curvature radius of the image side of the first lens, R5 is the curvature radius of the object side of the third lens, R6 is the curvature radius of the image side of the third lens, R7 is the curvature radius of the object side of the fourth lens, R10 is the curvature radius of the image side of the fifth lens, R11 is the curvature radius of the object side of the sixth lens, and R12 is the curvature radius of the image side of the sixth lens.

[0025] The high-pixel, wide-angle, compact optical system as described above satisfies the following relationship:

[0026] 1.8 <TTL / (CT1+CT2+CT3+CT4+CT5+CT6)<2.2;

[0027] Wherein, TTL is the on-axis distance from the object side of the first lens to the imaging plane, CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, CT4 is the center thickness of the fourth lens on the optical axis, CT5 is the center thickness of the fifth lens on the optical axis, and CT6 is the center thickness of the sixth lens on the optical axis.

[0028] The high-pixel, wide-angle, compact optical system as described above satisfies the following relationship:

[0029] 4.7<(DT11+DT12) / (DT62-DT61)<7.2;

[0030] Among them, DT11 is the maximum effective radius of the object side of the first lens, DT12 is the maximum effective radius of the image side of the first lens, DT61 is the maximum effective radius of the object side of the sixth lens, and DT62 is the maximum effective radius of the image side of the sixth lens.

[0031] The high-pixel, wide-angle, compact optical system as described above satisfies the following relationship:

[0032] 2.0 <f1234 / f2345<3.6;

[0033] Wherein, f1234 is the effective combined focal length of the first lens, the second lens, the third lens and the fourth lens, and f2345 is the effective combined focal length of the second lens, the third lens, the fourth lens and the fifth lens.

[0034] As described above, the high-pixel, wide-angle, compact optical system has a full field of view (FOV) and a total optical length (TTL) that satisfy the following requirements: 104°≤FOV≤111°, and TTL≤10.4 mm.

[0035] In the high-pixel, wide-angle, compact optical system described above, the first lens is a spherical lens, and the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are aspherical lenses.

[0036] In the high-pixel, wide-angle, compact optical system described above, the maximum effective radius DT11 of the object side of the first lens is ≤2.5;

[0037] The F number of the optical system is 2.2-2.5.

[0038] A head-mounted device comprises at least an optical lens, in which the above-mentioned high-pixel, wide-angle, compact optical system is installed.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] The optical system and head-mounted device of the embodiment of the present invention are mainly composed of 6 lenses, with a reasonable number of lenses and a simple structure. By reasonably allocating the effective focal length of the optical imaging lens, the on-axis distance from the object side of the first lens E1 to the imaging surface, and the ratio of half the diagonal length of the effective pixel area on the imaging surface, the light deflection angle is small, which can effectively reduce the sensitivity of the optical imaging lens, and can achieve ultra-thin, high-pixel and wide-angle optical imaging lenses. It can also be easily injection-molded and have a high assembly yield. It has a compact structure and good imaging quality, making the see-through optical system more competitive in the head-mounted device market. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments.

[0042] Figure 1 1 is a schematic structural diagram of the optical system or head-mounted device according to Example 1 of the present application;

[0043] Figure 2 axial chromatic aberration, astigmatism, and distortion curves of the optical system or head-mounted device of Example 1 of the present application;

[0044] Figure 3 2 is a schematic structural diagram of an optical system or head-mounted device according to Embodiment 2 of the present application;

[0045] Figure 4 axial chromatic aberration, astigmatism, and distortion curves of the optical system or head-mounted device of Example 2 of the present application;

[0046] Figure 5 2 is a schematic structural diagram of an optical system or head-mounted device according to Embodiment 3 of the present application;

[0047] Figure 6 axial chromatic aberration, astigmatism, and distortion curves of the optical system or head-mounted device of Example 3 of the present application;

[0048] Figure 7 2 is a schematic structural diagram of an optical system or head-mounted device according to Embodiment 4 of the present application;

[0049] Figure 8 axial chromatic aberration, astigmatism, and distortion curves of the optical system or head-mounted device of Example 4 of the present application;

[0050] Figure 9 Schematic diagram of the structure of the optical system or head-mounted device according to Example 5 of the present application;

[0051] Figure 10 This is a graph showing the on-axis chromatic aberration, astigmatism, and distortion of the optical system or head-mounted device of Example 5 of the present application. Detailed implementation manners

[0052] As shown Figure 1-10 in the figure, a high-pixel, large-angle, and compact optical system is composed of a first lens E1, a second lens E2, an aperture STO, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and an infrared filter E7 in sequence along the optical axis from the object plane to the image plane:

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

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

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

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

[0057] The image side surface of the sixth lens E6 is concave, and the optical power is negative;

[0058] Furthermore, as a preferred implementation manner of the present invention rather than a limitation, the effective focal length f of the optical system and the entrance pupil diameter EPD of the optical system satisfy: 2.2 < f / EPD < 2.5; by limiting the ratio of the effective focal length of the optical imaging system to the entrance pupil diameter, the optical imaging system has the characteristic of a large aperture.

[0059] Furthermore, as a preferred implementation manner of the present invention rather than a limitation, the optical system satisfies the following conditions: 1.2 < f / TTL*ImagH < 1.5; where f is the effective focal length of the optical system, EPD is the entrance pupil diameter of the optical system, TTL is the on-axis distance from the object side surface of the first lens E1 to the imaging plane, and ImgH is half of the diagonal length of the effective pixel area on the imaging plane. By reasonably allocating the ratio of the effective focal length of the optical imaging lens, the on-axis distance from the object side surface of the first lens E1 to the imaging plane, and half of the diagonal length of the effective pixel area on the imaging plane, the light deflection angle is small, the sensitivity of the optical imaging lens can be effectively reduced, the optical imaging lens can be thinned, high-pixel, and large-angle, and it is easy to be injection-molded and has a high assembly yield.

[0060] Furthermore, as a preferred embodiment of the present invention rather than a limitation, the effective focal length f5 of the fifth lens E5 and the effective focal length f6 of the sixth lens E6 satisfy: 3.2 < f5 / |(f5 + f6)| < 6.2; by reasonably distributing the proportion of the optical power of the fifth and sixth optical elements close to the image plane within a reasonable range, it is possible to balance the remaining spherical aberration after balancing to balance the spherical aberration generated by the first four elements, thereby finely adjusting and controlling the spherical aberration of the system and strengthening the precise control of the axial field aberration.

[0061] Furthermore, 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 f3 of the third lens E3 satisfy: 2.3 < |(f3 - f1) / f3| < 3.1; by reasonably controlling the range of the above formula, it is possible to contribute reasonable positive third-order spherical aberration and negative fifth-order spherical aberration to balance the negative third-order spherical aberration and positive fifth-order spherical aberration generated by the first lens E1 and the third lens E3, so that the system has a small spherical aberration and ensures good imaging quality of the axial field.

[0062] Furthermore, as a preferred embodiment of the present invention rather than a limitation, the effective focal length f5 of the fifth lens E5, the effective focal length f6 of the sixth lens E6, and the effective focal length f of the optical system satisfy: 1.8 < (f5 - f6) / f < 3.0; by restricting the effective focal lengths of the fifth lens E5, the sixth lens E6, and the optical imaging system within a reasonable range, it is possible to control the contribution of its coma within a reasonable range, so that the image quality of the axial field and off-axis field will not degenerate significantly due to the contribution of coma.

[0063] Furthermore, 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: 2.7 < (R1 + R2) / R2 < 3.6; by controlling the curvature radii of the object side and image side of the first lens E1, it is possible to reasonably control the total deflection angle of the object side and image side of the first lens E1 at the edge field within a reasonable range, and effectively reduce the sensitivity of the system.

[0064] Furthermore, 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, the curvature radius R6 of the image side of the third lens E3, and the curvature radius R7 of the object side of the fourth lens E4 satisfy: 1.5 < (R5 - R6) / R7 < 2.8; by reasonably controlling the ratio of the curvature radii of the object sides of the third and fourth lenses, the contribution of the astigmatism of the image side of the fourth lens E4 is within a reasonable range to balance the accumulated astigmatism of the previous system, so that the optical system has relatively good imaging quality in both the meridional plane and the sagittal plane.

[0065] Further, as a preferred embodiment of the present invention rather than a limitation, the radius of curvature R10 of the image side of the fifth lens E5, the radius of curvature R11 of the object side of the sixth lens E6, and the radius of curvature R12 of the image side of the sixth lens E6 satisfy: 3.4 < R12 + |R10 / R11| < 6.4; by controlling the radii of curvature of the object side and the image side of the fifth lens E5 and the sixth lens E6, it is possible to reasonably control the incident angle of the chief ray of each field of view of the optical imaging lens on the image plane, meeting the requirements of the incident angle of the chief ray in the optical system design.

[0066] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following relationship: 1.8 < TTL / (CT1 + CT2 + CT3 + CT4 + CT5 + CT6) < 2.2; where TTL is the on-axis distance from the object side of the first lens E1 to the imaging plane, CT1 is the central thickness of the first lens E1 on the optical axis, CT2 is the central thickness of the second lens on the optical axis, CT3 is the central thickness of the third lens E3 on the optical axis, CT4 is the central thickness of the fourth lens E4 on the optical axis, CT5 is the central thickness of the fifth lens E5 on the optical axis, and CT6 is the central thickness of the sixth lens E6 on the optical axis. By controlling the ratio range of the on-axis distance from the object side of the first lens E1 to the imaging plane to the total thickness of all lenses on the optical axis, it is possible to reasonably control the range of the remaining distortion after balancing, enabling the system to have good distortion performance.

[0067] Further, as a preferred embodiment of the present invention rather than a limitation, the optical system satisfies the following relationship: 4.7 < (DT11 + DT12) / (DT62 - DT61) < 7.2; where DT11 is the maximum effective radius of the object side of the first lens E1, DT12 is the maximum effective radius of the image side of the first lens E1, DT61 is the maximum effective radius of the object side of the sixth lens E6, and DT62 is the maximum effective radius of the image side of the sixth lens E6. By limiting the maximum effective radii of the object side and the image side of the first lens E1 and the sixth lens E6 within a reasonable range, it is possible to reduce the size of the lens, meet the miniaturization of the lens, and improve the resolution. <于

[0068] Further, as a preferred embodiment of the present invention rather than a limitation, the effective combined focal length f1234 of the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and the effective combined focal length f2345 of the second lens E2, the third lens E3, the fourth lens E4, and the fifth lens E5 satisfy: 2.0 < f1234 / f2345 < 3.6; by limiting the above sub-formulas within a reasonable range, on the one hand, it is beneficial to control the incident ray height of the light beam entering the optical system to reduce the high-order aberration of the optical system and the outer diameter of the lens; on the other hand, it can correct the influence of the field curvature generated by the front lens group on the resolution.

[0069] Furthermore, as a preferred embodiment of the present invention but not a limitation, the full field of view FOV of the optical system satisfies 104°≤FOV≤111°, so that the optical system can meet the requirements of a large field of view.

[0070] Furthermore, as a preferred embodiment of the present invention but not a limitation, the total optical length TTL of the optical system satisfies: TTL≤10.4 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.

[0071] Furthermore, as a preferred embodiment of the present invention but not limiting, the first lens E1 is a spherical lens, and the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, and the sixth lens E6 are aspherical lenses.

[0072] Furthermore, as a preferred embodiment of the present invention but not limiting, the maximum effective radius DT11 of the object side of the first lens E1 is ≤ 2.5; the structure is simple, which can effectively compress the size of the system and achieve a wide-angle characteristic.

[0073] Furthermore, as a preferred embodiment of the present invention but not a limitation, the optical system has an F number of 2.2-2.5, a compact structure, and is easy to process and install. At the same time, the large aperture configuration can increase the amount of light entering the optical system and higher imaging quality, making the head-mounted optical system more competitive in the market.

[0074] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 1-2 As shown in Example 1, the lens includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, 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.

[0075] 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 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 through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0076] In this embodiment 1, the focal length f1 of the first lens element E1 is -5.64 mm, the focal length f2 of the second lens element E2 is -44.65 mm, the focal length f3 of the third lens element E3 is 3.16 mm, the focal length f4 of the fourth lens element E4 is -23.28 mm, the focal length f5 of the fifth lens element E5 is 5.46 mm, the focal length f6 of the sixth lens element E6 is -3.80 mm, the lens focal length f is 3.93 mm, the total optical length TTL is 9.63 mm, the ImgH is 3.55 mm, the HFOV is 52.54°, and the f / EPD is 2.50. The surface type, curvature radius, thickness, and material parameters of each lens are shown in Table 1:

[0077] Table 1: Basic parameters of the optical system of Example 1

[0078] Face number Surface type Curvature radius (mm) Thickness (mm) Material OBJ spherical surface endless 2000 S1 spherical surface 5.1408 0.9888 1.91,35.25 S2 spherical surface 2.3400 1.1271 S3 Aspheric 36.0680 0.8500 1.66,20.38 S4 Aspheric 16.1836 0.3773 STO spherical surface endless -0.1607 S5 Aspheric 3.3591 0.9283 1.54,55.77 S6 Aspheric -3.1014 0.8280 S7 Aspheric 2.9163 0.4500 1.66,20.38 S8 Aspheric 2.3044 0.1653 S9 Aspheric 7.9652 1.0369 1.54,55.77 S10 Aspheric -4.4384 0.9573 S11 Aspheric -14.1151 1.0000 1.66,20.38 S12 Aspheric 3.1845 0.1897 S13 spherical surface endless 0.2100 1.52,64.17 S14 spherical surface endless 0.6853 S15 spherical surface endless

[0079] Furthermore, in Table 1, the object side and image side of any lens of the second lens E2 to the sixth lens E6 are all aspherical surfaces. The surface shape of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0080]

[0081] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 2 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for various aspheric surfaces that can be used in the first embodiment.

[0082] Table 2: Aspheric surface related values of the lens surface of Example 1

[0083]

[0084] Figure 2 The axial chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 1 are shown. Axial chromatic aberration indicates the deviation of light of different wavelengths from the focal point after passing through the lens; astigmatism indicates the meridional image curvature and sagittal image curvature; and distortion indicates the magnitude of distortion at different image heights. Figure 2 It can be seen that the optical imaging system provided in Example 1 can achieve good imaging quality, and has the advantages of high pixel density and wide angle.

[0085] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 3-4As shown in Example 2, the lens system includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, 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.

[0086] 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 through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0087] In this embodiment 2, the focal length f1 of the first lens element E1 is -4.81 mm, the focal length f2 of the second lens element E2 is 18.76 mm, the focal length f3 of the third lens element E3 is 3.63 mm, the focal length f4 of the fourth lens element E4 is -7.04 mm, the focal length f5 of the fifth lens element E5 is 5.06 mm, and the focal length f6 of the sixth lens element E6 is -5.88 mm. The lens focal length f is 3.71 mm, the total optical length TTL is 10.34 mm, the ImgH is 3.55 mm, the HFOV is 52.54°, and the f / EPD is 2.50. The surface type, curvature radius, thickness, and material parameters of each lens are shown in Table 3:

[0088] Table 3: Basic parameters of the optical system of Example 2

[0089] Face number Surface type Curvature radius (mm) Thickness (mm) Material OBJ spherical surface endless 2000 S1 spherical surface 4.8364 0.9128 1.91,35.25 S2 spherical surface 2.0976 1.1647 S3 Aspheric -10.9128 0.7808 1.66,20.38 S4 Aspheric -6.0048 0.6842 STO spherical surface endless -0.1053 S5 Aspheric 4.5718 1.1781 1.54,55.77 S6 Aspheric -3.0977 0.0300 S7 Aspheric 5.1290 0.6415 1.66,20.38 S8 Aspheric 2.3315 0.2139 S9 Aspheric 5.2320 1.0600 1.54,55.77 S10 Aspheric -5.2514 1.5532 S11 Aspheric 18.2134 1.0000 1.66,20.38 S12 Aspheric 3.1630 0.2318 S13 spherical surface endless 0.2100 1.52,64.17 S14 spherical surface endless 0.7813 S15 spherical surface endless

[0090] Furthermore, in Table 3, any one of the object side and image side surfaces of the second lens E2 to the sixth lens E6 is an aspherical surface. The surface shape of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0091]

[0092] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 4 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for various aspheric surfaces that can be used in the first embodiment.

[0093] Table 4: Aspheric surface related values of the lens surface of Example 2

[0094]

[0095] Figure 4 The axial chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 2 are shown. Axial chromatic aberration indicates the deviation of light of different wavelengths from the focal point after passing through the lens; astigmatism indicates the meridional image curvature and sagittal image curvature; distortion indicates the corresponding distortion value at different image heights, which is represented by Figure 4 It can be seen that the optical imaging system provided in Example 2 can achieve good imaging quality, and has the advantages of high pixel density and wide angle.

[0096] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 5-6 As shown in Example 3, the lens includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, 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.

[0097] 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 through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0098] In this embodiment 3, the focal length f1 of the first lens element E1 is -7.62 mm, the focal length f2 of the second lens element E2 is -16.54 mm, the focal length f3 of the third lens element E3 is 3.72 mm, the focal length f4 of the fourth lens element E4 is 400.00 mm, the focal length f5 of the fifth lens element E5 is 4.28 mm, the focal length f6 of the sixth lens element E6 is -3.03 mm, the lens focal length f is 3.94 mm, the total optical length TTL is 9.76 mm, the ImgH is 3.55 mm, the HFOV is 52.23°, and the f / EPD is 2.30. The surface type, curvature radius, thickness, and material parameters of each lens are shown in Table 5:

[0099] Table 5: Basic parameters of the optical system of Example 3

[0100] Face number Surface type Curvature radius (mm) Thickness (mm) Material OBJ spherical surface endless 2000 S1 spherical surface 4.3586 0.8637 1.91,35.25 S2 spherical surface 2.4303 1.1116 S3 Aspheric -24.2226 1.2000 1.66,20.38 S4 Aspheric 20.7704 0.3198 STO spherical surface endless -0.1581 S5 Aspheric 3.8956 0.8423 1.54,55.77 S6 Aspheric -3.7914 0.6094 S7 Aspheric 2.7760 0.4000 1.66,20.38 S8 Aspheric 2.6431 0.3299 S9 Aspheric 8.8214 1.1651 1.54,55.77 S10 Aspheric -2.9699 1.1783 S11 Aspheric -3.8829 0.8154 1.66,20.38 S12 Aspheric 4.6128 0.1775 S13 spherical surface endless 0.2100 1.52,64.17 S14 spherical surface endless 0.6969 S15 spherical surface endless

[0101] Furthermore, in Table 5, any one of the object side and image side surfaces of the second lens E2 to the sixth lens E6 is an aspherical surface. The surface shape of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0102]

[0103] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 6 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for various aspheric surfaces that can be used in the first embodiment.

[0104] Table 6: Aspheric surface related values of the lens surface of Example 3

[0105]

[0106] Figure 6 The axial chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 3 are shown. Axial chromatic aberration indicates the deviation of light of different wavelengths from the focal point after passing through the lens; astigmatism indicates the meridional and sagittal image curvatures; and distortion indicates the magnitude of distortion at different image heights. Figure 6 It can be seen that the optical imaging system provided in Example 3 can achieve good imaging quality, and has the advantages of high pixel density and wide angle.

[0107] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 7-8 As shown in Example 4, the lens includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, 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.

[0108] 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 through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0109] In this embodiment 4, the focal length f1 of the first lens element E1 is -7.09 mm, the focal length f2 of the second lens element E2 is -30.62 mm, the focal length f3 of the third lens element E3 is 3.54 mm, the focal length f4 of the fourth lens element E4 is -23.88 mm, the focal length f5 of the fifth lens element E5 is 4.33 mm, and the focal length f6 of the sixth lens element E6 is -3.25 mm. The lens focal length f is 3.80 mm, the total optical length TTL is 9.80 mm, the ImgH is 3.55 mm, the HFOV is 160.26°, and the f / EPD is 2.40. The surface type, curvature radius, thickness, and material parameters of each lens are shown in Table 7.

[0110] Table 7: Basic parameters of the optical system of Example 4

[0111] Face number Surface type Curvature radius (mm) Thickness (mm) Material OBJ spherical surface endless 2000 S1 spherical surface 4.4004 0.8423 1.91,35.25 S2 spherical surface 2.3835 1.1924 S3 Aspheric -12.1596 1.1624 1.66,20.38 S4 Aspheric -31.0770 0.3796 STO spherical surface endless -0.1366 S5 Aspheric 4.1583 0.7988 1.54,55.77 S6 Aspheric -3.2777 0.7372 S7 Aspheric 3.4804 0.4101 1.66,20.38 S8 Aspheric 2.7227 0.2660 S9 Aspheric 80.0000 1.1051 1.54,55.77 S10 Aspheric -2.3847 1.3254 S11 Aspheric -4.2455 0.6417 1.66,20.38 S12 Aspheric 4.7311 0.1750 S13 spherical surface endless 0.2100 1.52,64.17 S14 spherical surface endless 0.6893 S15 spherical surface endless

[0112] Furthermore, in Table 7, any one of the object side and image side surfaces of the second lens E2 to the sixth lens E6 is an aspherical surface. The surface shape of each aspherical lens can be defined using, but not limited to, the following aspherical surface formula:

[0113]

[0114] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 8 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for various aspheric surfaces that can be used in the first embodiment.

[0115] Table 8: Aspheric surface related values of the lens surface of Example 4

[0116]

[0117] Figure 8 The axial chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 4 are shown. Axial chromatic aberration indicates the deviation of light of different wavelengths from the focal point after passing through the lens; astigmatism indicates the meridional and sagittal image curvatures; and distortion indicates the magnitude of distortion at different image heights. Figure 8 It can be seen that the optical imaging system provided in Example 4 can achieve good imaging quality, and has the advantages of high pixel density and wide angle.

[0118] Specifically, as a preferred embodiment of the present invention but not limiting, Figure 9-10As shown in Example 5, the lens includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, 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.

[0119] 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 convex 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 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 concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes through each surface S1 to S14 in sequence and is ultimately imaged on the imaging surface S15.

[0120] In this embodiment 5, the focal length f1 of the first lens element E1 is -4.94 mm, the focal length f2 of the second lens element E2 is 58.17 mm, the focal length f3 of the third lens element E3 is 3.43 mm, the focal length f4 of the fourth lens element E4 is -11.53 mm, the focal length f5 of the fifth lens element E5 is 4.73 mm, the focal length f6 of the sixth lens element E6 is -3.80 mm, the lens focal length f is 3.63 mm, the total optical length TTL is 9.87 mm, the ImgH is 3.55 mm, the HFOV is 55.24°, and the f / EPD is 2.40. The surface type, curvature radius, thickness, and material parameters of each lens are shown in Table 9:

[0121] Table 9: Basic parameters of the optical system of Example 5

[0122] Face number Surface type Curvature radius (mm) Thickness (mm) Material OBJ spherical surface endless 2000 S1 spherical surface 6.2874 0.8000 1.91,35.25 S2 spherical surface 2.4739 1.0435 S3 Aspheric 100.0000 1.1319 1.66,20.38 S4 Aspheric -63.4025 0.6236 STO spherical surface endless -0.1603 S5 Aspheric 4.4392 0.8470 1.54,55.77 S6 Aspheric -2.9388 0.4926 S7 Aspheric 4.5291 0.4161 1.66,20.38 S8 Aspheric 2.7484 0.2869 S9 Aspheric -100.0000 0.9819 1.54,55.77 S10 Aspheric -2.4862 1.8822 S11 Aspheric -4.6895 0.4796 1.66,20.38 S12 Aspheric 5.7913 0.1641 S13 spherical surface endless 0.2100 1.52,64.17 S14 spherical surface endless 0.6725 S15 spherical surface endless

[0123] Furthermore, in Table 9, any one of the object side and image side surfaces of the second lens E2 to the sixth lens E6 is an aspherical surface. The surface shape of each aspherical lens can be defined using, but not limited to, the following aspherical surface formula:

[0124]

[0125] Where x is the distance from the corresponding point on the aspheric surface to the plane tangent to the vertex of the surface, h is the distance from the corresponding point on the aspheric surface to the optical axis, c is the curvature of the aspheric vertex, k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface shape formula. Table 10 shows the conic coefficients and higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for various aspheric surfaces that can be used in the first embodiment.

[0126] Table 10: Aspheric surface related values of the lens surface of Example 5

[0127]

[0128] Figure 10 The axial chromatic aberration, astigmatism, and distortion curves of the optical imaging lens of Example 5 are shown. Axial chromatic aberration indicates the deviation of light of different wavelengths from the focal point after passing through the lens; astigmatism indicates the meridional and sagittal image curvatures; and distortion indicates the magnitude of distortion at different image heights. Figure 10 It can be seen that the optical system provided in Example 5 can achieve good imaging quality, and has the advantages of high pixel density and wide angle.

[0129] Furthermore, in Examples 1-5, the basic data are shown in Table 11:

[0130] Table 11: Basic data of Examples 1-5

[0131] Basic data Example 1 Example 2 Example 3 Example 4 Example 5 f1(mm) -5.64 -4.81 -7.62 -7.09 -4.94 f2(mm) -44.65 18.76 -16.54 -30.62 58.17 f3(mm) 3.16 3.63 3.72 3.54 3.43 f4(mm) -23.28 -7.04 400.00 -23.88 -11.53 f5(mm) 5.46 5.06 4.28 4.33 4.73 f6(mm) -3.80 -5.88 -3.03 -3.25 -3.80 f(mm) 3.93 3.71 3.94 3.80 3.63 TTL(mm) 9.63 10.34 9.76 9.80 9.87 ImgH(mm) 3.55 3.55 3.55 3.55 3.55 HFOV(°) 52.54 52.26 52.23 53.16 55.24 f / EPD 2.50 2.20 2.30 2.40 2.40

[0132] In further embodiments 1-5, each conditional expression satisfies the conditions in Table 12 below:

[0133] Table 12: Conditions of each conditional formula in Examples 1-5

[0134] Conditional expression Example 1 Example 2 Example 3 Example 4 Example 5 R1 5.14 4.84 4.36 4.40 6.29 R2 2.34 2.10 2.43 2.38 2.47 R5 3.36 4.57 3.90 4.16 4.44 R6 -3.10 -3.10 -3.79 -3.28 -2.94 R7 2.92 5.13 2.78 3.48 4.53 R10 -4.44 -5.25 -2.97 -2.38 -2.49 R11 -14.12 18.21 -3.88 -4.25 -4.69 R12 3.18 3.16 4.61 4.73 5.79 f1234 5.69 10.45 6.62 6.22 7.10 f2345 2.80 2.90 2.77 2.83 2.90 DT11 2.50 2.50 2.50 2.50 2.50 DT12 1.63 1.63 1.73 1.72 1.71 DT61 1.95 2.04 2.07 2.10 2.15 DT62 2.82 2.84 2.81 2.80 2.74 f / TTL*ImagH 1.45 1.28 1.43 1.38 1.31 f5 / |(f5+f6)| 3.28 6.15 3.43 4.02 5.11 |(f3-f1) / f3| 2.78 2.32 3.05 3.00 2.44 (f5-f6) / f 2.36 2.94 1.86 2.00 2.35 (R1+R2) / R2 3.20 3.31 2.79 2.85 3.54 (R5-R6) / R7 2.22 1.50 2.77 2.14 1.63 R12+|R10 / R11| 3.50 3.45 5.38 5.29 6.32 TTL / (CT1+CT2+CT3+CT4+CT5+CT6) 1.83 1.85 1.85 1.98 2.12 (DT11+DT12) / (DT62-DT61) 4.73 5.15 5.73 6.08 7.15 f1234 / f2345 2.03 3.60 2.39 2.20 2.45

[0135] A head-mounted device includes at least an optical lens, in which the above-mentioned high-pixel, ultra-thin, wide-angle optical system is installed. The head-mounted optical system configured by the present invention has the advantages of high pixels and wide angle, a compact structure, and is easy to process and install. At the same time, the large aperture configuration can increase the amount of light entering the optical system and improve the imaging quality, making the head-mounted optical system more competitive in the head-mounted device market.

[0136] The above descriptions are provided in conjunction with specific content to provide one or more embodiments, and the specific implementation of the present invention is not limited to these descriptions. Any similarity or similarity with the methods, structures, etc. of the present invention, or any technical deduction or substitution based on the concept of the present invention, shall be considered within the scope of protection of the present invention.

Claims

1. A high-pixel, wide-angle, compact optical system, comprising, along the optical axis, from the object plane to the image plane, a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens, and a sixth lens, characterized in that: The object side surface of the first lens is convex, the image side surface is concave, and its optical power is negative; The object-side surface and image-side surface of the third lens are convex, and its optical power is positive; The object-side surface of the fourth lens is convex, and the image-side surface is concave; The image-side surface of the fifth lens is convex and has positive optical power; The image side surface of the sixth lens is concave and has negative optical power; The first lens is a spherical lens, and the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are aspherical lenses; The optical system meets the following conditions: 2.2 < f / EPD < 2.5; 1.2mm < f / TTL*ImgH < 1.5mm; Where f is the effective focal length of the optical system, EPD is the entrance pupil diameter of the optical system, TTL is the on-axis distance from the object side of the first lens to the imaging surface, and ImgH is half the diagonal length of the effective pixel area on the imaging surface.

2. The high-pixel, wide-angle, compact optical system according to claim 1, characterized in that: The optical system satisfies the following relationship: 3.2 < f5 / |(f5+f6)| < 6.2; 2.3 < |(f3-f1) / f3| < 3.1; 1.8 < (f5-f6) / f < 3.0; Wherein, f1 is the effective focal length of the first lens, f3 is the effective focal length of the third lens, f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f is the effective focal length of the optical system.

3. The high-pixel, wide-angle, compact optical system according to claim 1, characterized in that: The optical system satisfies the following relationship: The optical system satisfies the following relationship: 2.7 < (R1+R2) / R2 < 3.6; 1.5 < (R5-R6) / R7 < 2.8; Among them, R1 is the curvature radius of the object side of the first lens, R2 is the curvature radius of the image side of the first lens, R5 is the curvature radius of the object side of the third lens, R6 is the curvature radius of the image side of the third lens, and R7 is the curvature radius of the object side of the fourth lens.

4. The high-pixel, wide-angle, compact optical system according to any one of claims 1 to 3, characterized in that: The optical system satisfies the following relationship: 1.8 < TTL / (CT1+CT2+CT3+CT4+CT5+CT6) < 2.2; Wherein, TTL is the on-axis distance from the object side of the first lens to the imaging plane, CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, CT4 is the center thickness of the fourth lens on the optical axis, CT5 is the center thickness of the fifth lens on the optical axis, and CT6 is the center thickness of the sixth lens on the optical axis.

5. The high-pixel, wide-angle, compact optical system according to any one of claims 1 to 3, characterized in that: The optical system satisfies the following relationship: 4.7 < (DT11+DT12) / (DT62-DT61) < 7.2; Among them, DT11 is the maximum effective radius of the object side of the first lens, DT12 is the maximum effective radius of the image side of the first lens, DT61 is the maximum effective radius of the object side of the sixth lens, and DT62 is the maximum effective radius of the image side of the sixth lens.

6. The high-pixel, wide-angle, compact optical system according to any one of claims 1 to 3, characterized in that: The optical system satisfies the following relationship: 2.0 < f1234 / f2345 < 3.6; Among them, f1234 is the effective combined focal length of the first lens, the second lens, the third lens and the fourth lens, and f2345 is the effective combined focal length of the second lens, the third lens, the fourth lens and the fifth lens.

7. The high-pixel, wide-angle, compact optical system according to any one of claims 1 to 3, characterized in that: The full field of view (FOV) and total optical length (TTL) of the optical system satisfy the following requirements: 104°≤FOV≤111°, TTL≤10.4 mm.

8. The high-pixel, wide-angle, compact optical system according to any one of claims 1 to 3, characterized in that: The maximum effective radius DT11 of the object side surface of the first lens is ≤2.5 mm.

9. A head-mounted device comprising at least an optical lens, characterized in that: The optical lens is equipped with a high-pixel, wide-angle, compact optical system according to any one of claims 1 to 8.

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