Optical lens

Abstract

The application provides an optical lens, which comprises five lenses arranged along an optical axis from an exit pupil side to an image source side in sequence: an aperture; a first lens with positive focal power, wherein a material side is a convex surface and an image side is a concave surface; a second lens with positive focal power, wherein a material side is a convex surface and an image side is a concave surface; a third lens with negative focal power, wherein a material side is a convex surface and an image side is a concave surface; a fourth lens with negative focal power, wherein a material side is a concave surface; and a fifth lens with positive focal power, wherein a material side is a convex surface and an image side is a concave surface. The optical lens has the effects of small volume, light weight, short total length and large aperture.

Description

Technical Field

[0001] This invention relates to the technical field of imaging lenses, and particularly to an optical lens. Background Technology

[0002] With the rapid development of technology, the applications of projection lenses are becoming more diversified. The diverse application environments of lenses require maintaining stable performance and image quality.

[0003] The display eyepiece is the core optical component of AR glasses. Its key indicators, such as image quality, weight, and size, directly affect the user experience and comfort when wearing AR glasses. People have higher requirements for the optical engine system in this type of portable product in terms of size, weight, and image quality. Currently, the optical engines used in augmented reality glasses and other products on the market are large and heavy, making it difficult to meet the needs of increasingly miniaturized and lightweight smart glasses. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide an optical lens that at least solves the shortcomings of the above-mentioned technology.

[0005] This invention proposes an optical lens with a total of five lenses, arranged along the optical axis from the exit pupil side to the image source side as follows:

[0006] Aperture;

[0007] The first lens with positive optical power has a convex object side and a concave image side.

[0008] A second lens with positive optical power has a convex object-side surface and a concave image-side surface;

[0009] A third lens with negative optical power has a convex object side and a concave image side.

[0010] The fourth lens has negative optical power and its object side is concave.

[0011] The fifth lens with positive optical power has a convex object side and a concave image side.

[0012] Wherein, the total optical length TTL of the optical lens, the air gap T23 between the third lens and the second lens on the optical axis, and the air gap T34 between the fourth lens and the third lens on the optical axis satisfy: 3.5 < TTL / (T34-T23) < 5.2.

[0013] Furthermore, the total optical length (TTL) of the optical lens satisfies: TTL≤5.65mm.

[0014] Furthermore, the aperture value FNO of the optical lens satisfies: FNO≤1.8.

[0015] Furthermore, the effective focal length f1 of the first lens and the combined effective focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: 23 < |f1×f345| < 55.

[0016] Furthermore, the radius of curvature R11 of the first lens object side at the optical axis, the thickness CT1 of the first lens on the optical axis, and the refractive index nd of the first lens material satisfy: 5 < (R11 / CT1) × nd < 10.

[0017] Furthermore, the effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -3 < f4 / f < 0.

[0018] Furthermore, the radius of curvature R41 of the object side of the fourth lens at the optical axis, the radius of curvature R42 of the image side of the fourth lens at the optical axis, and the thickness CT5 of the fifth lens at the optical axis satisfy: -3≤R41 / (R42×CT5)≤1.5.

[0019] Furthermore, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < 3.1.

[0020] Furthermore, the outer diameter D11 of the object surface of the first lens, the outer diameter D31 of the object surface of the second lens, the radius of curvature R32 of the image surface of the second lens at the optical axis, and the effective focal length f of the optical lens satisfy: 1.4 < (D11 + D31) × R32 / f < 2.0.

[0021] Compared with the prior art, the beneficial effects of the present invention are: the optical lens of this application achieves the effects of small size, light weight, short total length and large aperture by reasonably matching the lens shape and optical power combination of each lens.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0024] Figure 1 This is a schematic diagram of the optical lens structure according to Embodiment 1 of the present invention;

[0025] Figure 2 The field curvature diagram and distortion diagram of the optical lens according to Embodiment 1 of the present invention are shown.

[0026] Figure 3This is a schematic diagram of the optical lens structure according to Embodiment 2 of the present invention;

[0027] Figure 4 The field curvature diagram and distortion diagram of the optical lens in Embodiment 2 of the present invention are shown.

[0028] Figure 5 This is a schematic diagram of the optical lens structure according to Embodiment 3 of the present invention;

[0029] Figure 6 The field curvature diagram and distortion diagram of the optical lens according to Embodiment 3 of the present invention are shown.

[0030] Figure 7 This is a schematic diagram of the optical lens structure according to Embodiment 4 of the present invention;

[0031] Figure 8 The images show the field curvature and distortion of the optical lens according to Embodiment 4 of the present invention.

[0032] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0033] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0034] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0035] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0036] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0037] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] The optical lens according to an embodiment of the present invention comprises, in sequence from the exit pupil side to the image source side: an aperture stop, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The aperture stop is preferably located before the first lens. Light from the image source (such as a MicroLED) passes through each lens sequentially and finally exits from the exit pupil, entering the subsequent waveguide sheet.

[0040] In some alternative embodiments, the first, second, and fifth lenses are set to positive optical power, which can converge light, shorten the overall length of the optical system, and reduce the size of the lens. The image side of the third lens is set to a concave surface, which can effectively refract light and obtain a larger image, satisfying the image magnification imaging function of the AR projection lens. The third and fourth lenses are set to negative optical power and are symmetrically distributed, which can effectively eliminate aberrations and improve image quality. By matching the optical power of each lens, aberrations such as astigmatism and field curvature in the optical system can be reduced, improving image quality while making the overall system length smaller.

[0041] In some alternative embodiments, the total optical length (TTL) of the optical lens satisfies: TTL ≤ 5.65 mm. Meeting this condition facilitates achieving an ultra-short total lens length and realizing miniaturization.

[0042] In some alternative embodiments, the aperture value FNO of the optical lens satisfies: FNO ≤ 1.8. Meeting this condition is beneficial for achieving large aperture characteristics, increasing the light transmission of the system, and ensuring sufficient image plane brightness even in darker environments.

[0043] In some optional embodiments, the total optical length TTL of the optical lens, the air gap T23 between the third lens and the second lens on the optical axis, and the air gap T34 between the fourth lens and the third lens on the optical axis satisfy the following condition: 3.5 < TTL / (T34-T23) < 5.2. Meeting this range helps reduce the lens sensitivity and improve the lens production and assembly yield. The comprehensive control of the above conditions allows the projection lens to improve its market competitiveness while meeting the goal of small size design.

[0044] In some optional embodiments, the effective focal length f1 of the first lens and the combined effective focal length f345 of the third, fourth, and fifth lenses satisfy: 23 < |f1×f345| < 55. Meeting this range helps reduce the design sensitivity of the optical system, allowing for a more rational configuration of the refractive power of each lens and improving the imaging quality of the optical system. Simultaneously, it also helps reduce the angle at which light exits the optical system after being refracted by the lens group, thereby reducing the incident angle of light entering the image-side photosensitive element of the optical system, improving the photosensitive performance of the photosensitive element, and ultimately enhancing the imaging quality of the optical system.

[0045] In some optional embodiments, the radius of curvature R11 of the object-side surface of the first lens at the optical axis, the thickness CT1 of the first lens on the optical axis, and the refractive index nd of the first lens material satisfy: 5 < (R11 / CT1) × nd < 10. Satisfying this range allows for a reasonable configuration of the ratio of the radius of curvature of the object-side surface of the first lens at the optical axis to the thickness of the first lens on the optical axis, reducing the sensitivity of the first lens and thus reducing the difficulty of manufacturing the first lens.

[0046] In some alternative embodiments, the effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -3 < f4 / f < 0. Meeting this range facilitates proper refractive power matching of the fourth lens within the optical system, allows for simpler and more flexible surface design of the fourth lens, reduces aberrations, and simplifies the overall aberration correction and image quality balance of the optical system.

[0047] In some optional embodiments, the radius of curvature R41 of the object-side surface of the fourth lens at the optical axis, the radius of curvature R42 of the image-side surface of the fourth lens at the optical axis, and the thickness CT5 of the fifth lens at the optical axis satisfy: -3≤R41 / (R42×CT5)≤1.5. Meeting this range helps control the shape of the fifth lens, reduces the manufacturing difficulty of the fifth lens, comprehensively balances the spherical aberration, chromatic aberration, and field curvature of the optical system, and improves the imaging quality of the optical system.

[0048] In some alternative embodiments, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < 3.1. Satisfying this condition is beneficial for the optical power configuration of the first lens and further reduces the overall system length.

[0049] In some optional embodiments, the outer diameter D11 of the object surface of the first lens, the outer diameter D31 of the object surface of the second lens, the radius of curvature R32 of the image surface of the second lens at the optical axis, and the effective focal length f of the optical lens satisfy: 1.4 < (D11 + D31) × R32 / f < 2.0. Satisfying this range is beneficial for optimizing the lens front diameter while ensuring optical performance, thereby minimizing the overall size and reducing weight.

[0050] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0051] Example 1

[0052] Please see Figures 1 to 2 The figure shows a schematic diagram of the structure of the optical lens in the first embodiment of the present invention. The optical lens includes, in sequence from the exit pupil side to the image source side: aperture stop STO, first lens L1, second lens L2, third lens L3, fourth lens L4, and fifth lens L5.

[0053] The first lens L1 has positive optical power, with its object side S1 being convex and its image side S2 being concave.

[0054] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is concave.

[0055] The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0056] The fourth lens L4 has negative optical power, and its object side S7 is concave, and its image side S8 is concave.

[0057] The fifth lens L5 has positive optical power, with its object side S9 being convex and its image side S10 being concave.

[0058] The relevant parameters of each lens in the optical lens of Example 1 are shown in Table 1-1.

[0059] Table 1-1

[0060]

[0061] The surface profile parameters of the aspherical lens in the optical lens of Example 1 are shown in Table 1-2.

[0062] Table 1-2

[0063]

[0064] Example 2

[0065] Please see Figures 3 to 4 The figure shows a schematic diagram of the structure of the optical lens in the second embodiment of the present invention. The optical lens includes, in sequence from the exit pupil side to the image source side: aperture stop STO, first lens L1, second lens L2, third lens L3, fourth lens L4, and fifth lens L5.

[0066] The first lens L1 has positive optical power, with its object side S1 being convex and its image side S2 being concave.

[0067] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is concave.

[0068] The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0069] The fourth lens L4 has negative optical power, and its object side S7 is concave, and its image side S8 is concave.

[0070] The fifth lens L5 has positive optical power, with its object side S9 being convex and its image side S10 being concave.

[0071] The relevant parameters of each lens in the optical lens of Example 2 are shown in Table 2-1.

[0072] Table 2-1

[0073]

[0074] The surface profile parameters of the aspherical lens in the optical lens of Example 2 are shown in Table 2-2.

[0075] Table 2-2

[0076]

[0077] Example 3

[0078] Please see Figures 5 to 6 The figure shows a schematic diagram of the structure of the optical lens in the third embodiment of the present invention. The optical lens includes, in sequence from the exit pupil side to the image source side: aperture stop STO, first lens L1, second lens L2, third lens L3, fourth lens L4, and fifth lens L5.

[0079] The first lens L1 has positive optical power, with its object side S1 being convex and its image side S2 being concave.

[0080] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is concave.

[0081] The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0082] The fourth lens L4 has negative optical power, and its object side S7 is concave, and its image side S8 is concave.

[0083] The fifth lens L5 has positive optical power, with its object side S9 being convex and its image side S10 being concave.

[0084] The relevant parameters of each lens in the optical lens of Example 3 are shown in Table 3-1.

[0085] Table 3-1

[0086]

[0087] The surface profile parameters of the aspherical lens in the optical lens of Example 3 are shown in Table 3-2.

[0088] Table 3-2

[0089]

[0090] Example 4

[0091] Please see Figures 7 to 8 The figure shown is a schematic diagram of the structure of the optical lens in the fourth embodiment of the present invention. The optical lens includes, in sequence from the exit pupil side to the image source side: aperture stop STO, first lens L1, second lens L2, third lens L3, fourth lens L4, and fifth lens L5.

[0092] The first lens L1 has positive optical power, with its object side S1 being convex and its image side S2 being concave.

[0093] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is concave.

[0094] The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0095] The fourth lens L4 has negative optical power, and its object side S7 is concave, and its image side S8 is concave.

[0096] The fifth lens L5 has positive optical power, with its object side S9 being convex and its image side S10 being concave.

[0097] The relevant parameters of each lens in the optical lens of Example 4 are shown in Table 4-1.

[0098] Table 4-1

[0099]

[0100] The surface profile parameters of the aspherical lens in the optical lens of Example 4 are shown in Table 4-2.

[0101] Table 4-2

[0102]

[0103] Please refer to Table 5-1 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value FNO, true image height IH, and maximum field of view FOV of the optical lens, as well as the values ​​corresponding to each conditional expression in each embodiment.

[0104] Table 5-1

[0105]

[0106] In summary, the optical lens in the above embodiments of the present invention achieves the effects of small size, light weight, short overall length, and large aperture by reasonably matching the lens shapes and optical power combinations among the lenses.

[0107] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0108] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An optical lens comprising five lenses, characterized in that, Along the optical axis from the exit pupil side to the image source side, the sequence is as follows: Aperture; The first lens with positive optical power has a convex object side and a concave image side. A second lens with positive optical power has a convex object-side surface and a concave image-side surface; A third lens with negative optical power has a convex object side and a concave image side. The fourth lens has negative optical power and its object side is concave. The fifth lens with positive optical power has a convex object side and a concave image side. Wherein, the total optical length TTL of the optical lens, the air gap T23 between the third lens and the second lens on the optical axis, and the air gap T34 between the fourth lens and the third lens on the optical axis satisfy: 3.5 < TTL / (T34-T23) < 5.2; The effective focal length f1 of the first lens and the combined effective focal length f345 of the third lens, the fourth lens and the fifth lens satisfy: 23 < |f1×f345| < 55.

2. The optical lens according to claim 1, characterized in that, The total optical length (TTL) of the optical lens satisfies: TTL≤5.65mm.

3. The optical lens according to claim 1, characterized in that, The aperture value FNO of the optical lens satisfies: FNO≤1.

8.

4. The optical lens according to claim 1, characterized in that, The radius of curvature R11 of the object side of the first lens at the optical axis, the thickness CT1 of the first lens on the optical axis, and the refractive index nd of the first lens material satisfy: 5 < (R11 / CT1) × nd < 10.

5. The optical lens according to claim 1, characterized in that, The effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy the following condition: -3 < f4 / f < 0.

6. The optical lens according to claim 1, characterized in that, The radius of curvature R41 of the object side of the fourth lens at the optical axis, the radius of curvature R42 of the image side of the fourth lens at the optical axis, and the thickness CT5 of the fifth lens at the optical axis satisfy: -3≤R41 / (R42×CT5)≤1.

5.

7. The optical lens according to claim 1, characterized in that, The effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f < 3.

1.

8. The optical lens according to claim 1, characterized in that, The outer diameter D11 of the object surface of the first lens, the outer diameter D31 of the object surface of the second lens, the radius of curvature R32 of the image side surface of the second lens at the optical axis, and the effective focal length f of the optical lens satisfy: 1.4 < (D11 + D31) × R32 / f < 2.0.

Images