Optical lens and near-eye display device

Abstract

The present invention provides an optical lens and a near-eye display device, which include a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in the reverse direction of light transmission; the first lens has positive focal power, and the light incident surface of the first lens is a convex surface; the second lens has positive focal power, the light exit surface of the second lens is a convex surface, and the light incident surface of the second lens is a concave surface; the third lens has positive focal power, the light exit surface of the third lens is a convex surface, and the light incident surface of the third lens is a convex surface; the fourth lens has negative focal power, and the light incident surface of the fourth lens is a concave surface; the fifth lens has positive focal power, and the light exit surface of the fifth lens is a convex surface; the sixth lens has focal power, and the light exit surface of the sixth lens is a concave surface. The optical lens provided by the present invention has at least one or more advantages such as telephoto, large field of view, low distortion, and the ability to match large-size image sources.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and in particular to an optical lens and a near-eye display device. Background Art

[0002] With the continuous advancement of optoelectronic devices and communication technology, virtual reality (VR) technology, as the forefront of the new generation of information technology, has achieved leapfrog development, and its forms and types are becoming increasingly diverse, and it is constantly being used in military, medical, education and consumer fields. Among them, head-mounted display devices usually transmit and amplify the information on the display screen through an optical system, and finally output it to the human eye. Therefore, the human eye receives the enlarged virtual image of the display screen, thereby achieving the purpose of large-screen viewing. At present, head-mounted display devices are developing in the direction of being more miniaturized, thinner, easier to wear, and lighter. At the same time, large field of view, low distortion and visual comfort have also become key evaluation indicators for the quality of head-mounted displays. Large field of view brings better immersion, low distortion and high image quality determine the visual comfort.

[0003] In order to meet these requirements, the optical system needs to achieve large field of view, low distortion, high image quality and other indicators at the same time. However, an increase in the field of view often leads to an increase in distortion. Therefore, meeting the above optical performance at the same time poses a huge challenge to the design of the optical system and the optimization of aberrations. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having one or more advantages such as telephoto, large field of view, low distortion, and the ability to match large-size image sources.

[0005] The technical solution adopted by the present invention is:

[0006] An optical lens, comprising six lenses, wherein the optical lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in sequence along the reverse direction of light transmission; the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens each comprise a light incident surface and a light exit surface, and the light incident surface and the light exit surface are arranged oppositely on the surface of each lens; the first lens has positive focal power, and the light incident surface of the first lens is a convex surface; the second lens has positive focal power, and the light exit surface of the second lens is a convex surface, and the light incident surface of the second lens is a concave surface; the third lens has positive focal power, and the light exit surface of the third lens is a convex surface, and the light incident surface of the third lens is a convex surface; the fourth lens has negative focal power, and the light incident surface of the fourth lens is a concave surface; the fifth lens has positive focal power, and the light exit surface of the fifth lens is a convex surface; the sixth lens has focal power, and the light exit surface of the sixth lens is a concave surface;

[0007] The total optical length TTL of the optical lens, the effective focal length f of the optical lens and the maximum field of view FOV of the optical lens satisfy the following conditions: <TTL / (f×tan(FOV / 2))<2.3。

[0008] The present invention also provides a near-eye display device, which includes, in sequence along the direction of light signal transmission: an image source and the above-mentioned optical lens; the image source is used to emit a light signal, and the light signal includes image information; the optical lens is arranged in the light emitting direction of the image source, and the sixth lens is arranged closer to the image source than the first lens, and the optical lens is used to modulate the light signal emitted by the image source and transmit it to the human eye.

[0009] Compared with the prior art, the optical lens provided by the present invention has a large field of view angle, low distortion and telephoto characteristics through a specific surface shape setting and reasonable optical focal length distribution. The large field of view angle can provide a wide field of view display effect, giving users a better experience. The lens has a telephoto characteristic, which can better present larger local details, making the picture more focused and compact, thereby meeting the needs; at the same time, the optical lens also has a larger image surface and higher resolution, which can match a large-size image source to achieve high-definition imaging, improve imaging quality, and bring users an excellent sensory experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0011] Figure 1 It is a schematic diagram of the structure of a near-eye display device provided in an embodiment of the present invention.

[0012] Figure 2 Schematic diagram of the structure of the optical lens provided in Example 1 of the present invention.

[0013] Figure 3 This is a dot pattern of the optical lens provided in Example 1 of the present invention.

[0014] Figure 4 This is a field curvature curve diagram of the optical lens provided in Example 1 of the present invention.

[0015] Figure 5 This is an MTF curve diagram of the optical lens provided in Example 1 of the present invention.

[0016] Figure 6 Schematic diagram of the structure of the optical lens provided in Example 2 of the present invention.

[0017] Figure 7 This is a dot pattern of the optical lens provided in Example 2 of the present invention.

[0018] Figure 8 This is a field curvature curve diagram of the optical lens provided in Example 2 of the present invention.

[0019] Fig. 9 This is an MTF curve diagram of the optical lens provided in Example 2 of the present invention.

[0020] Fig.10 Schematic diagram of the structure of the optical lens provided in Example 3 of the present invention.

[0021] Fig.11 This is a dot pattern of the optical lens provided in Example 3 of the present invention.

[0022] Fig.12 This is a field curvature curve diagram of the optical lens provided in Example 3 of the present invention.

[0023] Fig.13 This is an MTF curve diagram of the optical lens provided in Example 3 of the present invention.

[0024] Fig.14 Schematic diagram of the structure of the optical lens provided in Example 4 of the present invention.

[0025] Fig.15 This is a dot pattern of the optical lens provided in Example 4 of the present invention.

[0026] Fig.16 This is a field curvature curve diagram of the optical lens provided in Example 4 of the present invention.

[0027] Fig.17 This is an MTF curve diagram of the optical lens provided in Example 4 of the present invention.

[0028] Fig.18 This is a schematic diagram of the structure of the optical lens provided in Example 5 of the present invention.

[0029] Fig.19 This is a dot pattern of the optical lens provided in Example 5 of the present invention.

[0030] Fig. 20 This is a field curvature curve diagram of the optical lens provided in Example 5 of the present invention.

[0031] Fig.21 This is an MTF curve diagram of the optical lens provided in Example 5 of the present invention.

[0032] Fig. 22 This is a schematic diagram of the optical path of the near-eye display device provided in Example 6 of the present invention.

[0033] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0034] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application, and are not intended to limit the scope of the present 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.

[0035] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0036] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0037] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region.

[0038] It should also be understood that the terms "comprises", "including", "having", "includes" 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. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0039] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0040] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will detail the present application with reference to the accompanying drawings and in conjunction with the embodiments.

[0041] The present invention provides an optical lens. The optical lens is used to modulate the optical signal emitted by the image source and transmit it to the entrance pupil side of the human eye. The optical lens is arranged in the light-emitting direction of the image source, that is, the emission surface of the image source is the light-emitting side of the optical signal. Along the reverse direction of the light transmission (i.e., from the entrance pupil side of the human eye to the image source surface), it sequentially includes a diaphragm, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, and there is an air gap between any two adjacent lenses. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens each include an incident light surface and an exit light surface, and the incident light surface and the exit light surface are oppositely arranged on the surface of each lens. It can be understood that the surface of each lens close to the image source is called the incident light surface of the lens, and the surface of each lens close to the entrance pupil side of the human eye is called the exit light surface of the lens. The diaphragm is the entrance pupil of the imaging of this optical system. The human eye is at the position of the diaphragm, enabling the human eye to observe the best imaging effect.

[0042] In some embodiments, the first lens may have a positive optical power. The exit light surface of the first lens can be a concave surface, a convex surface, or a flat surface, and the incident light surface of the first lens is a convex surface. The second lens may have a positive optical power. The exit light surface of the second lens is a convex surface, and the incident light surface of the second lens is a concave surface. The third lens may have a positive optical power. The exit light surface of the third lens is a convex surface, and the incident light surface of the third lens is a convex surface. The fourth lens has a negative optical power. The exit light surface of the fourth lens can be a concave surface or a convex surface, and the incident light surface of the fourth lens is a concave surface. The fifth lens may have a positive optical power. The exit light surface of the fifth lens is a convex surface, and the incident light surface of the fifth lens can be a concave surface or a convex surface. The sixth lens may have a positive optical power or a negative optical power. The exit light surface of the sixth lens is a concave surface, and the incident light surface of the sixth lens can be a concave surface or a convex surface.

[0043] In some embodiments, the total optical length TTL of the optical lens, the effective focal length f of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 2 < TTL / (f × tan(FOV / 2)) < 2.3. Meeting the above conditions can enable the optical system to obtain a smaller total optical length and at the same time obtain a larger field of view, and can better meet the development direction of head-mounted display devices.

[0044] In some embodiments, the display area length IH of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 1.3 < IH / f < 1.4. Meeting the above conditions can enable the lens to have a larger image plane, be able to match a larger-sized image source to achieve high-definition imaging, and effectively improve the user's visual experience; at the same time, it can enable the lens to have a longer focal length and can improve the natural realism of the imaging picture.

[0045] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.3 < f1 / f < 3; the effective focal length f of the optical lens and the radius of curvature R2 of the incident light surface of the first lens satisfy: -2 < R2 / f < -0.7. Meeting the above conditions is beneficial for the light to have a larger field of view range after exiting the first lens, thereby providing a larger eye movement range and a better immersive experience for the user.

[0046] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.5 < f2 / f < 4; the radius of curvature R3 of the light-emitting surface of the second lens and the radius of curvature R4 of the incident light surface of the second lens satisfy: 0.1 < R3 / R4 < 0.7. Meeting the above conditions can further accelerate and converge the light into the human eye, reduce the total system length, and better realize the miniaturization of the system.

[0047] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.2 < f3 / f < 3; the radius of curvature R5 of the light-emitting surface of the third lens and the radius of curvature R6 of the incident light surface of the third lens satisfy: -3.5 < R5 / R6 < -1. Meeting the above conditions can enable the third lens to have better light-gathering ability, better converge the light at the large field of view angle, which is beneficial for reducing the correction difficulty of the marginal field aberration and improving the imaging quality of the system at the large field of view.

[0048] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.5 < f4 / f < -0.7. Meeting the above conditions is beneficial for reasonably balancing the aberrations brought by the first, second, and third lenses, while improving the resolution quality of the marginal field of view and achieving high imaging quality of the optical lens.

[0049] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.8 < f5 / f < 20. Meeting the above conditions can effectively converge the light emitted from the image source side, which is beneficial for matching a larger-sized image source to achieve high-definition imaging.

[0050] In some embodiments, the effective focal length f of the optical lens and the radius of curvature R9 of the light-emitting surface of the fifth lens satisfy: 1.2 < R9 / f < 3.5. Meeting the above conditions, by reasonably controlling the surface shape of the fifth lens, is beneficial for correcting optical distortion and aberration and improving the imaging quality of the optical lens.

[0051] In some embodiments, the focal length f1 of the first lens and the focal length f4 of the fourth lens satisfy: -2.7 < f1 / f4 < -1. Meeting the above conditions, by reasonably setting the focal length ratio of the first lens and the fourth lens, the light can enter the system at a relatively gentle angle, which is beneficial for correcting various aberrations of the optical lens and improving the imaging quality of the optical lens.

[0052] In some embodiments, the central thickness CT5 of the fifth lens and the central thickness CT6 of the sixth lens satisfy: 1.1 < CT5 / CT6 < 3.5; the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 1.4 < CT3 / CT4 < 2.5. Meeting the above conditions, by reasonably distributing the central thicknesses of the lenses, it is beneficial to improve the noise resistance of the optical lens, improve the production yield, and at the same time make the structure of the optical lens compact, realizing the miniaturization of the optical lens.

[0053] In some embodiments, the clear aperture semi-diameter DM11 of the light-emitting surface of the first lens and the clear aperture semi-diameter DM62 of the light-incident surface of the sixth lens satisfy: 0.72 < DM11 / DM62 < 0.85. Meeting the above conditions, by setting the aperture relationship of the first and last lenses in the lens, while ensuring that as much light as possible enters the system, the exit angle of the light is increased, better realizing the large viewing angle of the lens, thereby providing a larger eye movement range and a better immersive experience for the user.

[0054] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.3 < TTL / f < 1.7. Meeting the above conditions, the ratio of the overall length to the effective focal length of the optical lens can be reasonably controlled, making the optical lens have a shorter overall optical length and effectively reducing the system volume.

[0055] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.3 < f1 / f2 < 1.6; the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -3 < f3 / f4 < -1.4. Meeting the above conditions, by reasonably setting the proportion of the focal lengths of the lenses in the lens, it is beneficial to the smooth transition of light, and at the same time correct various aberrations of the optical lens, improving the imaging quality of the optical lens.

[0056] In some embodiments, the sum ∑CT of the central thicknesses along the optical axis of the first lens to the sixth lens and the overall optical length TTL of the optical lens satisfy: 0.65 < ∑CT / TTL < 0.8. Meeting the above conditions, by reasonably setting the sum of the overall lengths of the lenses, the overall length of the optical system can be effectively adjusted, and the exit pupil distance can be better distributed.

[0057] In some embodiments, the overall optical length TTL of the optical lens and the display area length IH of the image source that the optical lens can match satisfy: 1 < TTL / IH < 1.15. Meeting the above conditions, the overall optical length of the optical lens can be reasonably controlled, ensuring that the optical lens has a small volume while being able to match a larger-sized image source, improving the user's immersive experience.

[0058] In some embodiments, the optical lens satisfies the conditional formula: 35mm < TTL < 38mm, 24mm < f < 26mm, 33mm < IH < 34.5mm; where TTL represents the overall optical length of the optical lens, f represents the effective focal length of the optical lens, and IH represents the length of the display area of the image source that the optical lens can match. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least the characteristics of a long focal length and can match a large-size image source.

[0059] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. Additionally, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The first lens, the third lens, and the fifth lens of the present invention can be made of glass or plastic; the second lens can be made of glass; the fourth lens and the sixth lens can be made of plastic.

[0060] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the second lens of the present invention can adopt an aspherical lens, and the first lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can all adopt spherical or aspherical lenses.

[0061] In various embodiments of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0062] ;

[0063] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, F, G, H are the surface coefficients of the fourth order, sixth order, eighth order, tenth order, twelfth order, fourteenth order, and sixteenth order respectively.

[0064] In addition, the present invention also provides a near-eye display device, which sequentially includes, along the optical signal transmission direction: an image source, and the above-mentioned optical lens; the image source is used for emitting an optical signal, and the optical signal includes image information; the optical lens is disposed in the light-emitting direction of the image source, and the sixth lens is disposed closer to the image source than the first lens, and the optical lens is used for modulating the optical signal emitted by the image source and transmitting it to the human eye.

[0065] The present invention is further described below in multiple 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 table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0066] Example 1

[0067] See also Figure 1 , which is a schematic diagram of the structure of a near-eye display device 600 provided in an embodiment of the present invention, please refer to Figure 2 , which is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention, is used to modulate the optical signal emitted by the image source 10 and transmit it to the entrance pupil side of the human eye. The optical lens 100 is arranged in the light emitting direction of the image source 10, that is, the emitting surface of the image source 10 is the light emitting side of the optical signal. Figure 2 It can be seen that the optical lens 100 is sequentially provided with the following components along the reverse direction of light transmission (i.e., from the entrance pupil side of the human eye to the image source surface S13): the aperture ST, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 each include a light entrance surface and a light exit surface, and the light entrance surface and the light exit surface are arranged on the surface of each lens opposite to each other. It can be understood that the surface of each lens close to the image source 10 is called the light entrance surface of the lens, and the surface of each lens close to the entrance pupil side of the human eye is called the light exit surface of the lens. The aperture is the entrance pupil of the imaging of this optical system, and the human eye is at the aperture position, so that the human eye can observe the best imaging effect.

[0068] The first lens L1 has positive refractive power, a light exiting surface S1 of the first lens is a concave surface, and a light incident surface S2 of the first lens is a convex surface;

[0069] The second lens L2 has positive refractive power, a light exiting surface S3 of the second lens is a convex surface, and a light incident surface S4 of the second lens is a concave surface;

[0070] The third lens L3 has positive refractive power, a light exiting surface S5 of the third lens is a convex surface, and a light incident surface S6 of the third lens is a convex surface;

[0071] The fourth lens L4 has negative optical power, a light exiting surface S7 of the fourth lens is a concave surface, and a light incident surface S8 of the fourth lens is a concave surface;

[0072] The fifth lens L5 has positive refractive power, a light exiting surface S9 of the fifth lens L5 is a convex surface, and a light incident surface S10 of the fifth lens L5 is a convex surface;

[0073] The sixth lens L6 has negative refractive power, a light exiting surface S11 of the sixth lens L6 is a concave surface, and a light incident surface S12 of the sixth lens L6 is a concave surface;

[0074] In order to better realize the small size of the lens and reduce the cost while making the lens have a better imaging effect, the first lens L1, the second lens L2, and the third lens L3 are all glass aspherical lenses, the fourth lens L4 and the fifth lens L5 are all plastic aspherical lenses, and the sixth lens L6 is a plastic spherical lens.

[0075] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0076] Table 1-1

[0077]

[0078] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0079] Table 1-2

[0080]

[0081] Please refer to Figure 3 , which is a point diagram of the optical system of the optical lens 100. The scale in the figure is 200 (unit: μm), the field of view angle (unit: degree) is shown above each figure, and the corresponding image height (unit: mm) is shown below. It can be seen from the figure that the root mean square radius of the diffuse spot within the 0.5 field of view is less than 8μm, and the root mean square radius of the diffuse spot in the full field of view is less than 12μm, indicating that the image quality of the optical lens 100 is good, the aberration is well corrected, and the diffuse spot is close to the diffraction limit.

[0082] Please refer to Figure 4 , which is a field curvature curve of the optical lens 100, indicating the degree of curvature of light on the meridional image plane and the sagittal image plane, the horizontal axis indicates the offset (unit: mm), and the vertical axis indicates the field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.5mm, indicating that the optical lens 100 can correct the field curvature well.

[0083] Please refer to Figure 5, which is a graph of the MTF (modulation transfer function) of the optical lens 100, where the horizontal axis represents the spatial frequency (unit: lp / mm) and the vertical axis represents the modulation degree of the optical transfer function. It can be seen from the figure that the MTF value of the entire field of view is greater than 0.7 at 16lp / mm, and the curve is compact and falls smoothly, indicating that the optical lens 100 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0084] Example 2

[0085] See also Figure 6 , which is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main differences of this embodiment are: the second lens L2 adopts a glass aspherical lens; the first lens L1, the third lens L3, the fourth lens L4, and the sixth lens L6 all adopt plastic aspherical lenses; the fifth lens L5 adopts a plastic spherical lens; the light incident surface S12 of the sixth lens L6 is a convex surface at the near optical axis; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0086] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0087] Table 2-1

[0088]

[0089] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0090] Table 2-2

[0091]

[0092] from Figure 7 It can be seen that the root mean square radius of the diffuse spot within the 0.5 field of view is less than 10 μm, and the root mean square radius of the diffuse spot in the full field of view is less than 11 μm, which means that the image quality of the optical lens 200 is good, the aberration is well corrected, and it is less affected by diffraction.

[0093] from Figure 8 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±1 mm, indicating that the optical lens 200 can correct the field curvature well.

[0094] from Fig. 9 It can be seen that the MTF value of the whole field of view is greater than 0.68 at 16lp / mm, and the curve is compact and the decline is smooth, which means that the optical lens 200 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0095] Example 3

[0096] See also Fig.10 , which is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main differences of this embodiment are: the first lens L1 and the third lens L3 are both glass spherical lenses; the second lens L2 is a glass aspherical lens; the fourth lens L4 and the sixth lens L6 are both plastic aspherical lenses; the fifth lens L5 is a plastic spherical lens; the sixth lens L6 has positive power; the light exit surface S1 of the first lens L1 is convex, the light incident surface S10 of the fifth lens L5 is concave, and the light incident surface S12 of the sixth lens L6 is convex at the near optical axis; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0097] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0098] Table 3-1

[0099]

[0100] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0101] Table 3-2

[0102]

[0103] from Fig.11 It can be seen that the root mean square radius of the diffuse spot in the whole field of view is less than 10 μm, which means that the image quality of the optical lens 300 is good, the aberration is well corrected, and the imaging quality is good.

[0104] from Fig.12 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.4 mm, indicating that the optical lens 300 can correct the field curvature well.

[0105] from Fig.13 It can be seen that the MTF value of the whole field of view is greater than 0.7 at 16lp / mm, and the curve is compact and the decline is smooth, which means that the optical lens 300 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0106] Example 4

[0107] See also Fig.14, which is a schematic diagram of the structure of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, the main differences of this embodiment are: the first lens L1 adopts a glass spherical lens; the second lens L2 and the third lens L3 both adopt glass aspherical lenses; the sixth lens L6 adopts a plastic aspherical lens; the fourth lens L4 and the fifth lens L5 adopt plastic spherical lenses; the light-emitting surface S1 of the first lens L1 is a plane, the light-emitting surface S7 of the fourth lens L4 is a convex surface, and the light-entering surface S12 of the sixth lens L6 is a convex surface at the near optical axis; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0108] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0109] Table 4-1

[0110]

[0111] The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0112] Table 4-2

[0113]

[0114] from Fig.15 It can be seen that the root mean square radius of the diffuse spot in the whole field of view is less than 12 μm, which means that the image quality of the optical lens 400 is good, the aberration is well corrected, and the imaging quality is good.

[0115] from Fig.16 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.8mm, indicating that the optical lens 400 can correct the field curvature well.

[0116] from Fig.17 It can be seen that the MTF value of the whole field of view is greater than 0.65 at 16lp / mm, and the curve is compact and the decline is smooth, which means that the optical lens 400 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0117] Example 5

[0118] See also Fig.18 , shown is a schematic diagram of the structure of an optical lens 500 provided in Example 5 of the present invention. Compared with Example 1, the main differences of this embodiment are: the first lens L1, the second lens L2, the third lens L3, and the fifth lens L5 are all glass aspheric lenses; the fourth lens L4 and the sixth lens L6 are plastic aspheric lenses; the light-emitting surface S7 of the fourth lens L4 is a convex surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0119] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0120] Table 5-1

[0121]

[0122] The surface parameters of the aspheric lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0123] Table 5-2

[0124]

[0125] from Fig.19 It can be seen that the root mean square radius of the diffuse spot in the whole field of view is less than 12 μm, which means that the image quality of the optical lens 500 is good, the aberration is well corrected, and the imaging quality is good.

[0126] from Fig. 20 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.7mm, indicating that the optical lens 500 can correct the field curvature well.

[0127] from Fig.21 It can be seen that the MTF value of the whole field of view is greater than 0.6 at 16lp / mm, and the curve is compact and the decline is smooth, which means that the optical lens 500 has good resolution and contrast, and the imaging at the edge position and the center position has good consistency.

[0128] Please refer to Table 6, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the maximum field of view FOV, the back focal length BFL, and the display area length IH of the image source that the optical lens can match and the corresponding values ​​of each conditional expression in each embodiment.

[0129] Table 6

[0130]

[0131] In summary, the optical lens provided by the present invention has at least the following advantages:

[0132] (1) Through specific surface shape settings and reasonable optical focal length distribution, the optical lens has a larger field of view (FOV ≥ 70°) and telephoto characteristics. The larger field of view can provide a wide field of view display effect, giving users a better experience. The lens has a telephoto characteristic, which can better present larger local details, making the picture more focused and compact, thus meeting the needs.

[0133] (2) The optical lens also has a larger image surface, smaller distortion (distortion within 3%) and higher resolution, which can match large-size image sources to achieve high-definition imaging, improve imaging quality, and bring users an excellent sensory experience.

[0134] Example 6

[0135] See also Fig. 22 , which is a schematic diagram of an optical path in a near-eye display device 600 provided by an embodiment of the present invention, the near-eye display device 600 includes an image source 10, an optical lens (such as the optical lens 100) in any of the aforementioned embodiments of the present application, and the optical lens is located between the human eye 20 and the image source 10. The image information emitted from the image source 10 enters the human eye 20 through the optical lens to form an image, and the human eye 20 can observe a high-definition magnified virtual image, which has an extremely realistic sensory experience.

[0136] The image source 10 is used to emit a light signal, and the light signal includes image information. Specifically, the image source 10 can be one of a display screen such as Micro LED, OLED, LCD, LCOS, M-OLED, etc. More specifically, in this embodiment, the image source 10 can use a 1.3-inch Micro OLED display screen, which can provide high-definition image information for the optical lens.

[0137] The optical lens is arranged in the light emitting direction of the image source 10 , and the sixth lens in the optical lens is arranged closer to the image source 10 than the first lens. The optical lens is used to modulate the light signal emitted by the image source 10 and transmit it to the human eye 20 .

[0138] The near-eye display device 600 may be VR glasses, VR helmets, head-mounted display devices, etc. Since the above optical lens has a large field of view angle and telephoto characteristics, the large field of view angle can provide a wide field of view display effect, improve the user's sense of immersion, and thus bring a better experience to the user. The lens has a telephoto characteristic, which can better present larger local details, making the picture more focused and compact, thereby meeting the needs. At the same time, the optical lens also has a larger image surface and a higher resolution. The light signal image modulated by the optical lens is bright and clear, with better effects, and the picture projected to the human eye is clearer. Therefore, the near-eye display device equipped with the optical lens has at least the characteristics of a wide field of view and high image quality, which can effectively improve the user's visual experience and comfort.

[0139] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0140] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, comprising six lenses, characterized in that: The optical lens sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens along the reverse direction of light transmission; the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens each include an incident light surface and an exit light surface, and the incident light surface and the exit light surface are oppositely arranged on the surface of each lens; The first lens has a positive optical power, and the incident light surface of the first lens is a convex surface; The second lens has a positive optical power, the exit light surface of the second lens is a convex surface, and the incident light surface of the second lens is a concave surface; The third lens has a positive optical power, the exit light surface of the third lens is a convex surface, and the incident light surface of the third lens is a convex surface; The fourth lens has a negative optical power, and the incident light surface of the fourth lens is a concave surface; The fifth lens has a positive optical power, and the exit light surface of the fifth lens is a convex surface; The sixth lens has an optical power, and the exit light surface of the sixth lens is a concave surface; Wherein, the total optical length TTL of the optical lens, the effective focal length f of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 2 < TTL / (f×tan(FOV / 2)) < 2.

3.

2. The optical lens according to claim 1, characterized in that: The length IH of the display area of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 1.3 < IH / f < 1.

4.

3. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.3 < f1 / f < 3; the effective focal length f of the optical lens and the curvature radius R2 of the incident light surface of the first lens satisfy: -2 < R2 / f < -0.

7.

4. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.5 < f2 / f < 4; the curvature radius R3 of the exit light surface of the second lens and the curvature radius R4 of the incident light surface of the second lens satisfy: 0.1 < R3 / R4 < 0.

7.

5. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.2 < f3 / f < 3; the curvature radius R5 of the exit light surface of the third lens and the curvature radius R6 of the incident light surface of the third lens satisfy: -3.5 < R5 / R6 < -1.

6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.5 < f4 / f < -0.

7.

7. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.8 < f5 / f < 20; the effective focal length f of the optical lens and the curvature radius R9 of the exit light surface of the fifth lens satisfy: 1.2 < R9 / f < 3.

5.

8. The optical lens according to claim 1, characterized in that: The focal length f1 of the first lens and the focal length f4 of the fourth lens satisfy: -2.7 < f1 / f4 < -1.

9. The optical lens according to claim 1, characterized in that: The central thickness CT5 of the fifth lens and the central thickness CT6 of the sixth lens satisfy: 1.1 < CT5 / CT6 < 3.5; the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 1.4 < CT3 / CT4 < 2.

5.

10. The optical lens according to claim 1, characterized in that: The semi-aperture DM11 of the light exiting surface of the first lens and the semi-aperture DM62 of the light incident surface of the sixth lens satisfy: 0.72 <DM11 / DM62<0.85。 11. A near-eye display device, characterized in that: The optical signal transmission direction includes: an image source, an optical lens according to any one of claims 1 to 10; The image source is used to emit a light signal, and the light signal includes image information; The optical lens is arranged in the light emitting direction of the image source, and the sixth lens is arranged closer to the image source than the first lens. The optical lens is used to modulate the light signal emitted by the image source and transmit it to the human eye.

Images