Eyepiece system and near-eye display device

Abstract

An eyepiece system and a near-eye display device. The eyepiece system (10) includes a plurality of lenses arranged in sequence along the same optical axis from the image side to the object side, the refractive index of the plurality of lenses being greater than 1.65, and the total length of the system of the plurality of lenses along the main optical axis being less than or equal to 25 mm. In the disclosed embodiment, the refractive index of each lens included in the eyepiece system (10) is greater than 1.65, so that the total length of the system of the plurality of lenses is reduced while the eyepiece system (10) has a high refractive power, so as to ensure that the eyepiece system (10) has a high imaging quality and realize the miniaturization of the eyepiece system (10).

Description

Technical Field

[0001] The present disclosure relates to the field of near-eye display technologies, and particularly to an eyepiece system and a near-eye display device. Background Art

[0002] NED (Near-Eye Display) refers to using optical technologies to guide the image light emitted by a micro-image light source to the user's pupil through an eyepiece system, and realizing a virtual and magnified image in the near-eye range of the user, so as to provide intuitive image, video or text information to the user. Currently, near-eye display technologies on the market are usually widely applied to VR (Virtual Reality) systems, AR (Augmented Reality) systems, MR (Mixed Reality) systems, etc.

[0003] As the user's requirements for the interactivity and immersion of virtual images, text and other information are getting higher and higher, related near-eye display devices such as head-mounted displays, AR glasses, and VR helmets have received more favor from people.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present disclosure is to provide an eyepiece system and a near-eye display device, which can realize the miniaturization of the eyepiece system, and further realize the miniaturization of the near-eye display device.

[0006] According to one aspect of the present disclosure, an eyepiece system is provided, which is applied to a near-eye display device. The eyepiece system includes:

[0007] A plurality of lenses arranged in sequence along the same optical axis from the image side to the object side. The refractive indices of the plurality of lenses are all greater than 1.65, and the total system length of the plurality of lenses along the principal optical axis is less than or equal to 25 millimeters.

[0008] According to the eyepiece system of the present disclosure, the plurality of lenses are arranged in the same straight line direction.

[0009] According to the eyepiece system of the present disclosure, the optical power of the eyepiece system is greater than or equal to 50m -1 , and less than or equal to 65m -1 .

[0010] According to the eyepiece system of the present disclosure, the plurality of lenses include, arranged in sequence along the same optical axis from the image side to the object side:

[0011] The first lens, having a convex image side and a concave or flat object side;

[0012] The second lens, having a convex image side and a concave object side;

[0013] The third lens, having a convex image side and a concave object side;

[0014] The fourth lens, having a convex image side and a concave object side;

[0015] The fifth lens, having a convex image side and a convex object side, or having a convex image side and a flat object side;

[0016] The sixth lens, having a concave image side and a convex object side;

[0017] The seventh lens, having a convex image side and a concave object side; or having a flat image side and a convex object side.

[0018] For the eyepiece system according to the present disclosure, the first lens, the second lens, the third lens, the fifth lens, and the seventh lens are all positive-power lenses, and the fourth lens and the sixth lens are both negative-power lenses.

[0019] For the eyepiece system according to the present disclosure, the image sides and object sides of multiple lenses are all spherical surfaces; or,

[0020] The image side and object side of the first lens, the object side of the second lens, the image side and object side of the third lens, the image side and object side of the fourth lens, the image side and object side of the fifth lens, the image side and object side of the sixth lens, and the object side of the seventh lens are all spherical surfaces, and the image side of the second lens and the image side of the seventh lens are both aspherical surfaces; or,

[0021] The image side and object side of the first lens, the object side of the second lens, the image side and object side of the third lens, the image side and object side of the fourth lens, the image side and object side of the fifth lens, the object side of the sixth lens, and the object side of the seventh lens are all spherical surfaces, and the image side of the second lens, the image side of the sixth lens, and the image side of the seventh lens are all aspherical surfaces.

[0022] For the eyepiece system according to the present disclosure,

[0023] The central thickness of the first lens is greater than or equal to 2.6 mm and less than or equal to 3.4 mm;

[0024] The central thickness of the second lens is greater than or equal to 1.4 mm and less than or equal to 2.1 mm;

[0025] The central thickness of the third lens is greater than or equal to 2.4 mm and less than or equal to 3.5 mm;

[0026] The central thickness of the fourth lens is greater than or equal to 1.3 mm and less than or equal to 1.6 mm;

[0027] The central thickness of the fifth lens is greater than or equal to 1.7 mm and less than or equal to 2.4 mm;

[0028] The central thickness of the sixth lens is greater than or equal to 0.5 mm and less than or equal to 2.4 mm;

[0029] The central thickness of the seventh lens is greater than or equal to 1.8 mm and less than or equal to 3.8 mm.

[0030] For the eyepiece system according to the present disclosure,

[0031] The radius of curvature of the image side of the first lens is greater than or equal to 10 mm and less than or equal to 20 mm, and the radius of curvature of the object side is greater than or equal to 30 mm;

[0032] The radius of curvature of the image side of the second lens is greater than or equal to 5 mm and less than or equal to 20 mm, and the radius of curvature of the object side is greater than or equal to 5 mm and less than or equal to 25 mm;

[0033] The radius of curvature of the image side of the third lens is greater than or equal to 5 mm and less than or equal to 15 mm, and the radius of curvature of the object side is greater than or equal to 15 mm and less than or equal to 55 mm;

[0034] The radius of curvature of the image side of the fourth lens is greater than or equal to 15 mm and less than or equal to 55 mm, and the radius of curvature of the object side is less than or equal to 10 mm;

[0035] The radius of curvature of the image side of the fifth lens is greater than or equal to 5 mm and less than or equal to 110 mm, and the radius of curvature of the object side is greater than or equal to 10 mm;

[0036] The radius of curvature of the image side of the sixth lens is less than or equal to 50 mm, and the radius of curvature of the object side is greater than or equal to 10 mm and less than or equal to 40 mm;

[0037] The radius of curvature of the image side of the seventh lens is greater than or equal to 5 mm, and the radius of curvature of the object side is greater than or equal to 10 mm and less than or equal to 50 mm.

[0038] For the eyepiece system according to the present disclosure, the object side of the third lens and the image side of the fourth lens are both spherical surfaces and have the same radius of curvature;

[0039] The object side of the third lens and the image side of the fourth lens are glued together with an optical adhesive.

[0040] According to the eyepiece system described in the present disclosure,

[0041] The refractive index of the first lens is greater than or equal to 1.72 and less than or equal to 1.74;

[0042] The refractive index of the second lens is greater than or equal to 1.78 and less than or equal to 1.84;

[0043] The refractive index of the third lens is greater than or equal to 1.65 and less than or equal to 1.80;

[0044] The refractive index of the fourth lens is greater than or equal to 1.80 and less than or equal to 1.95;

[0045] The refractive index of the fifth lens is greater than or equal to 1.75 and less than or equal to 1.85;

[0046] The refractive index of the sixth lens and the refractive index of the seventh lens are both greater than or equal to 1.70 and less than or equal to 1.80.

[0047] According to the eyepiece system described in the present disclosure,

[0048] The Abbe number of the first lens and the Abbe number of the third lens are both greater than or equal to 45 and less than or equal to 60;

[0049] The Abbe number of the second lens and the Abbe number of the fifth lens are both greater than or equal to 40 and less than or equal to 50;

[0050] The Abbe number of the fourth lens, the Abbe number of the sixth lens, and the Abbe number of the seventh lens are all greater than or equal to 20 and less than or equal to 30.

[0051] According to the eyepiece system described in the present disclosure, the material of the lens is glass or resin.

[0052] According to one aspect of the present disclosure, there is provided a near-eye display device, comprising:

[0053] An image source for outputting image light;

[0054] The eyepiece system described in the above one aspect, disposed in the light-emitting direction of the image source.

[0055] The embodiments of the present disclosure at least include the following technical effects:

[0056] In the embodiments of the present disclosure, the refractive indices of the lenses included in the eyepiece system are all greater than 1.65. In this way, on the premise that the eyepiece system has a high refractive power, the total length of the system of multiple lenses is reduced to ensure miniaturization of the eyepiece system while ensuring high imaging quality of the eyepiece system.

[0057] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0059] Figure 1 It is a schematic structural diagram of an eyepiece system provided for the embodiments of the present disclosure.

[0060] Figure 2 It is a schematic optical path diagram of an eyepiece system provided for the embodiments of the present disclosure.

[0061] Figure 3 It is a schematic structural diagram of another eyepiece system provided for the embodiments of the present disclosure.

[0062] Figure 4 It is a schematic structural diagram of yet another eyepiece system provided for the embodiments of the present disclosure.

[0063] Figure 5 It is an MTF curve diagram of an eyepiece system provided for the embodiments of the present disclosure.

[0064] Figure 6 It is a spot diagram of an eyepiece system provided for the embodiments of the present disclosure.

[0065] Figure 7 It is an MTF curve diagram of another eyepiece system provided for the embodiments of the present disclosure.

[0066] Figure 8 It is a spot diagram of another eyepiece system provided for the embodiments of the present disclosure.

[0067] Figure 9 It is an MTF curve diagram of yet another eyepiece system provided for the embodiments of the present disclosure.

[0068] Figure 10 It is a spot diagram of yet another eyepiece system provided for the embodiments of the present disclosure.

[0069] Figure 11MTF curve graph of another eyepiece system provided by the embodiments of the present disclosure.

[0070] Figure 12 Spot diagram of another eyepiece system provided by the embodiments of the present disclosure.

[0071] Figure 13 MTF curve graph of yet another eyepiece system provided by the embodiments of the present disclosure.

[0072] Figure 14 Spot diagram of yet another eyepiece system provided by the embodiments of the present disclosure.

[0073] Reference numerals:

[0074] 10. Eyepiece system; 20. Micro display screen; 30. Pupil. Detailed implementation manners

[0075] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures, and thus their detailed descriptions will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0076] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the icon to another component, these terms are used in this specification only for convenience, for example, according to the directions of the examples described in the accompanying drawings. It can be understood that if the device of the icon is turned upside down, the component described as "upper" will become the component described as "lower". When a structure is "on" another structure, it may mean that a structure is integrally formed on another structure, or that a structure is "directly" disposed on another structure, or that a structure is "indirectly" disposed on another structure through another structure.

[0077] The terms "a", "an", "the", "said" and "at least one" are used to indicate the existence of one or more elements / components / etc.; the terms "comprising" and "having" are used to mean an open inclusion and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc.; the terms "first", "second" and "third", etc. are only used as labels and are not a limitation on the quantity of their objects.

[0078] With the continuous development of near-eye display technology, for smart wearable devices, taking AR glasses as an example, in order to meet the usage requirements of consumer-grade glasses, users have an increasing demand for the smaller volume of AR glasses. Therefore, while ensuring the image quality of near-eye display in smart wearable devices, miniaturization needs to be achieved.

[0079] An embodiment of the present disclosure provides a schematic structural diagram of an eyepiece system 10. As Figure 1 shown, the eyepiece system 10 includes a plurality of lenses sequentially arranged along the same optical axis from the image side to the object side. The refractive indices of the plurality of lenses are all greater than 1.65, and the overall system length TL of the plurality of lenses along the principal optical axis is less than or equal to 25 millimeters.

[0080] In the embodiment of the present disclosure, the refractive indices of the respective lenses included in the eyepiece system 10 are all greater than 1.65. Thus, on the premise that the eyepiece system 10 has a high refractive power, the overall system length TL of the plurality of lenses L is reduced. When the overall system length of the plurality of lenses is reduced, the focal length of the eyepiece system 10 is synchronously reduced, so as to achieve the miniaturization of the eyepiece system 10 while ensuring that the eyepiece system 10 has a high imaging quality.

[0081] Among them, the refractive ratio of the eyepiece system (overall system length / effective focal length) is greater than 1. The overall system length TL of the plurality of lenses refers to the distance between the image side of the lens farthest from the microdisplay 20 among the plurality of lenses along the principal optical axis and the center of the microdisplay 20. Optionally, the overall system length of the plurality of lenses along the principal optical axis can also be less than or equal to 21 millimeters to further achieve the miniaturization of the eyepiece system 10. Exemplarily, the overall system length of the plurality of lenses along the principal optical axis is 19 millimeters, 20 millimeters, or 21 millimeters.

[0082] The eyepiece system 10 is usually used in combination with the microdisplay 20, and the microdisplay 20 and the eyepiece system 10 are distributed along the optical path propagation direction. As Figure 2 shown, the image light emitted by the microdisplay 20 is incident on the incident light side of the eyepiece system 10, and is refracted by the eyepiece system 10 for collimation and magnification; the refracted light is emitted from the exit light side of the eyepiece system 10 and is incident into the user's pupil 30, so as to provide intuitive image, video or text information to the user within the user's near-eye range.

[0083] Among them, the microdisplay 20 can be a microdisplay using a screen such as LCD, OLED, LCOS or LED, and the screen size of the microdisplay 20 is 0.3 inches to 0.5 inches.

[0084] In the embodiment of the present disclosure, the material of the lenses included in the eyepiece system 10 can be glass, can be resin, or can also be plastic. The materials of the plurality of lenses can all be the same, can all be different, or can also be not all the same.

[0085] The number of lenses L included in the eyepiece system 10 can be five, six, seven, eight, etc., as long as the total system length TL of the multiple lenses can be less than or equal to 25 millimeters. The embodiments of the present disclosure do not limit this.

[0086] Optionally, the multiple lenses are arranged in the same linear direction. In this way, by arranging the multiple lenses in the same linear direction, the situation where the eyepiece system has a large size in the radial direction of the lenses is avoided.

[0087] Optionally, the multiple lenses are arranged in sequence along the same optical axis. In order to effectively reduce the total system length of the eyepiece system 10, the physical radius of the middle lens can be set to be the smallest. The concave surfaces of some image-side lenses located on the image side of the middle lens all face the object side, and the physical radius of the image-side lenses increases in the direction away from the object side; the concave surfaces of some object-side lenses located on the object side of the middle lens all face the image side, and the physical radius of the object-side lenses increases in the direction away from the image side. In this way, the image-side lenses and object-side lenses on both sides of the middle lens can be moved as close as possible to the middle lens to reduce the total system length of the eyepiece system 10.

[0088] Among them, when the total number of lenses included in the eyepiece system 10 is odd, the middle lens can be the lens in the middle of the multiple lenses, or a lens adjacent to the middle lens. When the total number of lenses included in the eyepiece system 10 is even, the middle lens can be any one of the two lenses in the middle of the multiple lenses.

[0089] Optionally, the optical power of the eyepiece system 10 is greater than or equal to 50m -1 , and less than or equal to 65m -1 . In this way, the eyepiece system 10 can converge and refract the image light emitted by the micro display screen 20 to ensure the effect of directivity magnification of the image light. At the same time, the exit pupil area exiting to the pupil 30 is 5 millimeters * 17 millimeters, and the distortion is less than 3%. In this way, the advantages of a large exit pupil, small distortion, or even no distortion of the virtual image are realized. Of course, in addition to any value within the above range, the optical power of the eyepiece system 10 can also be other values, as long as it can ensure the directivity magnification effect of the eyepiece system 10 on the image light.

[0090] Next, an example will be given with the eyepiece system 10 including seven lenses.

[0091] As Figure 1 or Figure 2 shown, the multiple lenses include: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7, which are arranged in sequence along the same optical axis from the image side to the object side.

[0092] Optionally, the image side of the first lens L1 is convex, and the object side is concave or flat; the image side of the second lens L2 is convex, and the object side is concave; the image side of the third lens L3 is convex, and the object side is concave; the image side of the fourth lens L4 is convex, and the object side is concave; the image side of the fifth lens L5 is convex, and the object side is convex, or its image side is convex and the object side is flat; the image side of the sixth lens L6 is concave, and the object side is convex; the image side of the seventh lens L7 is convex, and the object side is concave; or the image side is flat and the object side is convex. As shown in the figure, the shaping of the image light by the cooperation of the convex surface, concave surface and flat surface is realized by seven lenses, so as to achieve high-quality imaging quality, that is, to improve the imaging quality of the picture of the eyepiece system 10.

[0093] Among them, the above-mentioned image side refers to the curved surface of the lens closer to the pupil 30 along the direction of the same optical axis, and the object side refers to the curved surface of the lens closer to the micro display screen 20 along the direction of the same optical axis.

[0094] Example 1, as Figure 1 or Figure 2 shown, the image side of the first lens L1 is convex, and the object side is concave; the image side of the second lens L2 is convex, and the object side is concave; the image side of the third lens L3 is convex, and the object side is concave; the image side of the fourth lens L4 is convex, and the object side is concave; the image side of the fifth lens L5 is convex, and the object side is convex; the image side of the sixth lens L6 is concave, and the object side is convex; the image side of the seventh lens L7 is convex, and the object side is concave.

[0095] Example 2, as Figure 3 shown, the image side of the first lens L1 is convex, and the object side is flat; the image side of the second lens L2 is convex, and the object side is concave; the image side of the third lens L3 is convex, and the object side is concave; the image side of the fourth lens L4 is convex, and the object side is concave; the image side of the fifth lens L5 is convex, and the object side is convex; the image side of the sixth lens L6 is concave, and the object side is convex; the image side of the seventh lens L7 is convex, and the object side is convex.

[0096] Example 3, as Figure 4 shown, the image side of the first lens L1 is convex, and the object side is concave; the image side of the second lens L2 is convex, and the object side is concave; the image side of the third lens L3 is convex, and the object side is concave; the image side of the fourth lens L4 is convex, and the object side is concave; the image side of the fifth lens L5 is convex, and the object side is flat; the image side of the sixth lens L6 is concave, and the object side is convex; the image side of the seventh lens L7 is flat, and the object side is convex.

[0097] Optionally, the image side and object side of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 can be spherical surfaces or aspherical surfaces. Of course, the image side or object side of some lenses can also be flat surfaces.

[0098] Example 1: The image side and object side of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are all spherical surfaces.

[0099] Example 2: The image side and object side of the first lens L1, the object side of the second lens L2, the image side and object side of the third lens L3, the image side and object side of the fourth lens L4, the image side and object side of the fifth lens L5, the image side and object side of the sixth lens L6, and the object side of the seventh lens L7 are all spherical surfaces. The image side of the second lens L2 and the image side of the seventh lens L7 are both aspherical surfaces.

[0100] Example 3: The image side and object side of the first lens L1, the object side of the second lens L2, the image side and object side of the third lens L3, the image side and object side of the fourth lens L4, the image side and object side of the fifth lens L5, the object side of the sixth lens L6, and the object side of the seventh lens L7 are all spherical surfaces. The image side of the second lens L2, the image side of the sixth lens L6, and the image side of the seventh lens L7 are all aspherical surfaces.

[0101] Among them, for the case where the curved surface is a spherical surface, its surface shape satisfies the following first formula:

[0102]

[0103] In the above first formula, z is the sag of the spherical surface, c is the radius of curvature of the curved surface, k is the conic coefficient of the curved surface, which takes the constant 0 for a spherical surface, and r is the physical radius of the lens corresponding to the curved surface.

[0104] For the case where the curved surface is an aspherical surface, its surface shape satisfies the following second formula:

[0105]

[0106] In the above second formula, z is the sag of the aspherical surface, c is the radius of curvature of the curved surface, k is the conic coefficient of the curved surface, r is the physical radius of the lens corresponding to the curved surface, and A 2i is the 2*i - order coefficient of the aspherical surface, where i is an integer greater than or equal to 1.

[0107] Generally, for the multi - order coefficients of an aspherical surface, the fourth - order coefficient with i = 2 and the sixth - order coefficient with i = 3 are usually considered; of course, the second - order coefficient with i = 1, the eighth - order coefficient with i = 4, etc. can also be considered, and it can be determined according to the actual situation.

[0108] Optionally, the central thickness of the first lens L1 is greater than or equal to 2.6 mm and less than or equal to 3.4 mm, the central thickness of the second lens is greater than or equal to 1.4 mm and less than or equal to 2.1 mm, the central thickness of the third lens L3 is greater than or equal to 2.4 mm and less than or equal to 3.5 mm, the central thickness of the fourth lens L4 is greater than or equal to 1.3 mm and less than or equal to 1.6 mm, the central thickness of the fifth lens L5 is greater than or equal to 1.7 mm and less than or equal to 2.4 mm, the central thickness of the sixth lens L6 is greater than or equal to 0.5 mm and less than or equal to 2.4 mm, and the central thickness of the seventh lens L7 is greater than or equal to 1.8 mm and less than or equal to 3.8 mm. Thus, by limiting the central thickness of each lens, it is convenient to make the total system length TL of the eyepiece system 10 composed of seven lenses smaller. Among them, the above-mentioned central thickness refers to the thickness of the lens along the direction of the principal optical axis.

[0109] In addition, for the intermediate spacing between two adjacent lenses, it can be determined according to the surface profiles of the opposite surfaces of the two adjacent lenses. Specifically, if the surface profiles of the opposite surfaces of two adjacent lenses match, the central spacing between the two adjacent lenses can be 0; if the surface profiles of the opposite surfaces of two adjacent lenses do not match (the radii of curvature are different), then in order to avoid interference between the two lenses, it is necessary to determine the central spacing between the two adjacent lenses in combination with the radii of curvature of the two opposite surfaces. Further, for two adjacent lenses with a non-zero central spacing, in order to further ensure the collimation and magnification effect of the image light, the central spacing between the two adjacent lenses is greater than or equal to 0.1 mm.

[0110] Optionally, the radius of curvature of the image side of the first lens L1 is greater than or equal to 10 mm and less than or equal to 20 mm, and the radius of curvature of the object side is greater than or equal to 30 mm; the radius of curvature of the image side of the second lens L2 is greater than or equal to 5 mm and less than or equal to 20 mm, and the radius of curvature of the object side is greater than or equal to 5 mm and less than or equal to 25 mm; the radius of curvature of the image side of the third lens L3 is greater than or equal to 5 mm and less than or equal to 15 mm, and the radius of curvature of the object side is greater than or equal to 15 mm and less than or equal to 55 mm; the radius of curvature of the image side of the fourth lens L4 is greater than or equal to 15 mm and less than or equal to 55 mm, and the radius of curvature of the object side is less than or equal to 10 mm; the radius of curvature of the image side of the fifth lens L5 is greater than or equal to 5 mm and less than or equal to 110 mm, and the radius of curvature of the object side is greater than or equal to 10 mm; the radius of curvature of the image side of the sixth lens L6 is less than or equal to 50 mm, and the radius of curvature of the object side is greater than or equal to 10 mm and less than or equal to 40 mm; the radius of curvature of the image side of the seventh lens L7 is greater than or equal to 5 mm, and the radius of curvature of the object side is greater than or equal to 10 mm and less than or equal to 50 mm.

[0111] Among them, for the curvature radii of the image side and object side of each lens, if the surface types of the two opposite surfaces are both spherical surfaces and the curvature radii are equal, the corresponding two lenses can be glued together to reduce the number of individual components, thereby improving the assembly efficiency of the eyepiece system 10.

[0112] Exemplarily, the object side of the third lens L3 and the image side of the fourth lens L4 are both spherical surfaces and have the same curvature radius; as Figure 1 or Figure 2 shown, the object side of the third lens L3 is glued to the image side of the fourth lens L4 to achieve the gluing of the third lens L3 and the fourth lens L4.

[0113] Among them, the third lens L3 and the fourth lens L4 can be glued together by an optical adhesive such as an optical curing adhesive or an epoxy resin adhesive. Of course, the third lens L3 and the fourth lens L4 can also be glued together by a light-transmitting adhesive, and the embodiments of the present disclosure do not limit this.

[0114] Optionally, the refractive index of the first lens L1 is greater than or equal to 1.72 and less than or equal to 1.74; the refractive index of the second lens L2 is greater than or equal to 1.78 and less than or equal to 1.84; the refractive index of the third lens L3 is greater than or equal to 1.65 and less than or equal to 1.80; the refractive index of the fourth lens L4 is greater than or equal to 1.80 and less than or equal to 1.95; the refractive index of the fifth lens L5 is greater than or equal to 1.75 and less than or equal to 1.85; the refractive indices of the sixth lens L6 and the seventh lens L7 are both greater than or equal to 1.70 and less than or equal to 1.80. Thus, by limiting the refractive indices of the respective lenses, through the cooperation of the refractive indices among the seven lenses, the refractive power of the eyepiece system 10 is enhanced to reduce the overall system length TL of the eyepiece system 10 and simultaneously reduce the focal length of the eyepiece system 10.

[0115] Optionally, the Abbe numbers of the first lens L1 and the third lens L3 are both greater than or equal to 45 and less than or equal to; the Abbe numbers of the second lens L2 and the fifth lens L5 are both greater than or equal to 40 and less than or equal to; the Abbe numbers of the fourth lens L4, the sixth lens L6, and the seventh lens L7 are all greater than or equal to 20 and less than or equal to 30. Thus, by limiting the Abbe numbers of the respective lenses of the eyepiece system 10, after the dispersion effects of the respective lenses on the image light are coordinated, the dispersion of the image light is reduced to improve the imaging quality of the eyepiece system 10.

[0116] Optionally, the first lens L1, the second lens L2, the third lens L3, the fifth lens L5, and the seventh lens L7 are all positive power lenses, and the fourth lens L4 and the sixth lens L6 are both negative power lenses.

[0117] Among them, for the image light emitted by the microdisplay 20, it can be collimated and magnified through the converging refraction of the seventh lens L7, the diverging refraction of the sixth lens L6, the converging refraction of the fifth lens L5, the diverging refraction of the fourth lens L4, and the converging refractions of the third lens L3, the second lens L2, and the first lens L1, and the exit pupil area exiting to the pupil 30 is 5 mm * 17 mm, and the distortion is less than 3%. In this way, the advantages of a large exit pupil, small distortion, or even no distortion of the virtual image are achieved.

[0118] Exemplarily, in combination with the case where the third lens L3 and the fourth lens L4 are cemented as described above, the optical power of the first lens L1 is greater than or equal to 32 m -1 and less than or equal to 48 m -1 , the optical power of the second lens L2 is greater than or equal to 12 m -1 and less than or equal to 26 m -1 , the optical power of the cemented lens (the third lens L3 and the fourth lens L4) is greater than or equal to -68 m -1 and less than or equal to -45 m -1 , the optical power of the fifth lens L5 is greater than or equal to 52 m -1 and less than or equal to 80 m -1 , the optical power of the sixth lens L6 is greater than or equal to -55 m -1 and less than or equal to -25 m -1 , the optical power of the seventh lens L7 is greater than or equal to 50 m -1 and less than or equal to 65 m -1 .

[0119] Of course, in the embodiments of the present disclosure, for the sixth lens and the seventh lens, it is also possible that the sixth lens is a positive optical power lens and the seventh lens is a negative optical power lens. Exemplarily, the optical power of the sixth lens is greater than 0 and less than or equal to 8 m -1 , the optical power of the seventh lens is greater than or equal to -15 m -1 and less than 0.

[0120] Embodiment 1. The present disclosure shows the parameters of the seven lenses included in the eyepiece system 10 in Table 1 below.

[0121] Table 1

[0122]

[0123]

[0124] In Table 1 above, f is the focal length, TL is the total system length, k is the conic coefficient, FOV is the field of view angle, R is the radius of curvature, T is the central thickness, L is the center distance between itself and the adjacent lens or micro display on the object side, Φ is the optical power (the third lens and the fourth lens are cemented), n is the refractive index, and V is the Abbe number. Additionally, the positive or negative sign of the radius of curvature of the image side and the object side refers to the relative position of the center of the curved surface with respect to the corresponding surface. By way of example, the center of the image side of the first lens L1 is located on the object side of the image side, and the center of the object side of the fifth lens is located on the image side of the object side.

[0125] Figure 5 This is the MTF (Modulation Transfer Function) curve graph of the eyepiece system 10 shown in Table 1 provided by Embodiment 1 of the present disclosure. Figure 6 This is the spot diagram of the eyepiece system 10 shown in Table 1 provided by Embodiment 1 of the present disclosure. Figure 5 In the horizontal axis, the spatial frequency is represented, which represents the number of line pairs per millimeter, with the unit of 1p / mm. The vertical axis represents the percentage of the imaging quality reaching the physical object condition, ranging from 0 to 1.

[0126] From Figure 5 and Figure 6 it can be seen that the MTF of the eyepiece system 10 is greater than 0.45@50lp / mm, that is, when the spatial frequency is 50lp / mm, the imaging quality reaches at least 45% of the physical object condition, and the RMS (Root Mean Square) radius of the central field of view of the eyepiece system 10 is less than 5μm. This indicates that the size of the blur spot of the eyepiece system 10 is small, the imaging quality is excellent, and the distortion is imperceptible to the human eye, so as to achieve a high-quality imaging effect.

[0127] Embodiment 2: The present disclosure shows the parameters of the seven lenses included in the eyepiece system 10 in Table 2 below.

[0128] Table 2

[0129]

[0130]

[0131] In Table 2 above, f is the focal length, TL is the total system length, k is the conic coefficient, FOV is the field of view angle, R is the radius of curvature, T is the central thickness, L is the center distance between itself and the adjacent lens or micro display on the object side, Φ is the optical power (the third lens and the fourth lens are cemented), n is the refractive index, and V is the Abbe number. Additionally, the positive or negative sign of the radius of curvature of the image side and the object side refers to the relative position of the center of the curved surface with respect to the corresponding surface. By way of example, the center of the image side of the first lens L1 is located on the object side of the image side, and the center of the object side of the fifth lens is located on the image side of the object side.

[0132] Figure 7 This is the MTF (Modulation Transfer Function) curve graph of the eyepiece system 10 shown in Table 2 provided in the first embodiment of the present disclosure. Figure 8 This is the spot diagram of the eyepiece system 10 shown in Table 2 provided in the first embodiment of the present disclosure. Figure 7 The horizontal axis represents the spatial frequency, which represents the number of line pairs per millimeter, with the unit of 1p / mm, and the vertical axis represents the percentage of the imaging quality reaching the actual object condition, ranging from 0 to 1.

[0133] From Figure 7 and Figure 8 it can be seen that the MTF of the eyepiece system 10 is greater than 0.45@50lp / mm, that is, when the spatial frequency is 50lp / mm, the imaging quality reaches at least 45% of the actual object condition, and the RMS (Root Mean Square) radius of the central field of view of the eyepiece system 10 is less than 6.5μm. This shows that the size of the blur spot of the eyepiece system 10 is small, the imaging quality is excellent, and the distortion is imperceptible to the human eye, so as to achieve high-quality imaging effects.

[0134] Embodiment 3: The present disclosure shows the parameters of the seven lenses included in the eyepiece system 10 in combination with Table 3 and Table 4 as follows.

[0135] Table 3

[0136]

[0137] Table 4

[0138]

[0139]

[0140] In the above Table 3 and Table 4, f is the focal length, TL is the total length of the system, k is the conic coefficient, FOV is the field of view angle, R is the radius of curvature, T is the central thickness, L is the center distance between itself and the adjacent lens or micro display on the object side, Φ is the optical power (the third lens and the fourth lens are cemented), n is the refractive index, V is the Abbe number, A 4 、A 6 . is the 2*i - order coefficient of the aspherical surface, where i is an integer greater than or equal to 1. In addition, the positive and negative of the radius of curvature of the image side and the object side refer to the relative position of the center of the curved surface and the corresponding surface. By way of example, the center of the image side of the first lens L1 is located on the object side of the image side, and the center of the object side of the fifth lens is located on the image side of the object side.

[0141] Figure 9The MTF (Modulation Transfer Function) curve graph of the eyepiece system 10 shown in Table 3 and Table 4 provided in the first embodiment of the present disclosure. Figure 10 The spot diagram of the eyepiece system 10 shown in Table 3 and Table 4 provided in the first embodiment of the present disclosure. Figure 9 The horizontal axis is the spatial frequency, representing the number of line pairs per millimeter, with the unit of 1p / mm, and the vertical axis represents the percentage of the imaging quality reaching the physical object condition, ranging from 0 to 1.

[0142] From Figure 9 and Figure 10 it can be seen that the MTF of the eyepiece system 10 is greater than or equal to 0.6 @ 50lp / mm, that is, when the spatial frequency is 50lp / mm, the imaging quality reaches at least 60% of the physical object condition, and the RMS (Root Mean Square) radius of the central field of view of the eyepiece system 10 is less than 3μm. This shows that the size of the blur spot of the eyepiece system 10 is small, the imaging quality is excellent, and the distortion is imperceptible to the human eye, so as to achieve high-quality imaging effects.

[0143] Embodiment 4: The present disclosure shows the various parameters of the seven lenses included in the eyepiece system 10 in conjunction with Table 5 and Table 6 as follows.

[0144] Table 5

[0145]

[0146]

[0147] Table 6

[0148]

[0149] In the above Table 5 and Table 6, f is the focal length, TL is the total length of the system, k is the conic coefficient, FOV is the field of view angle, R is the radius of curvature, T is the central thickness, L is the center distance between itself and the adjacent lens or the micro display on the object side, Φ is the optical power (the third lens and the fourth lens are cemented), n is the refractive index, V is the Abbe number, A 4 、A 6 . is the 2*i order coefficient of the aspheric surface, and i is an integer greater than or equal to 1. In addition, the positive and negative of the radius of curvature of the image side and the object side refer to the relative position of the center of the curved surface and the corresponding surface. By way of example, the center of the image side of the first lens L1 is located on the object side of the image side, and the center of the object side of the fifth lens is located on the image side of the object side.

[0150] Figure 11It is the MTF (Modulation Transfer Function) curve graph of the eyepiece system 10 shown in Table 5 and Table 6 provided in Embodiment 1 of the present disclosure. Figure 12 It is the spot diagram of the eyepiece system 10 shown in Table 5 and Table 6 provided in Embodiment 1 of the present disclosure. Figure 11 The horizontal axis is the spatial frequency, representing the number of line pairs per millimeter, with the unit of 1p / mm, and the vertical axis represents the percentage of the imaging quality reaching the physical object condition, ranging from 0 to 1.

[0151] From Figure 11 and Figure 12 it can be seen that the MTF of the eyepiece system 10 is greater than or equal to 0.65@50lp / mm, that is, when the spatial frequency is 50lp / mm, the imaging quality reaches at least 65% of the physical object condition, and the RMS (Root Mean Square) radius of the central field of view of the eyepiece system 10 is less than 2.5μm. This indicates that the size of the blur spot of the eyepiece system 10 is small, the imaging quality is excellent, and the distortion is imperceptible to the human eye, so as to achieve high-quality imaging effects.

[0152] Embodiment 5: The present disclosure shows the parameters of the seven lenses included in the eyepiece system 10 in conjunction with Table 7 and Table 8 below.

[0153] Table 7

[0154]

[0155]

[0156] Table 8

[0157]

[0158] In the above Table 7 and Table 8, f is the focal length, TL is the total length of the system, k is the conic coefficient, FOV is the field of view angle, R is the radius of curvature, T is the central thickness, L is the center distance between itself and the adjacent lens or the micro display on the object side, Φ is the optical power (the third lens and the fourth lens are cemented), n is the refractive index, V is the Abbe number, A 4 、A 6 . is the 2*i order coefficient of the aspheric surface, and i is an integer greater than or equal to 1. In addition, the positive and negative of the radius of curvature of the image side and the object side refer to the relative position of the center of the curved surface and the corresponding surface. By way of example, the center of the image side of the first lens L1 is located on the object side of the image side, and the center of the image side of the sixth lens is located on the image side of the object side.

[0159] Figure 13This is the MTF (Modulation Transfer Function) curve graph of the eyepiece system 10 shown in Table 7 and Table 8 provided in Embodiment 1 of the present disclosure. Figure 14 This is the spot diagram of the eyepiece system 10 shown in Table 7 and Table 8 provided in Embodiment 1 of the present disclosure. Figure 13 The horizontal axis represents the spatial frequency, which represents the number of line pairs per millimeter, with the unit of 1p / mm, and the vertical axis represents the percentage of the imaging quality reaching the physical object condition, ranging from 0 to 1.

[0160] It can be seen from Figure 13 and Figure 14 that the MTF of the eyepiece system 10 is greater than or equal to 0.5 @ 50lp / mm, that is, when the spatial frequency is 50lp / mm, the imaging quality reaches at least 50% of the physical object condition, and the RMS (Root Mean Square) radius of the central field of view of the eyepiece system 10 is less than 5μm. This shows that the size of the blur spot of the eyepiece system 10 is small, the imaging quality is excellent, and the distortion is imperceptible to the human eye, so as to achieve high-quality imaging effects.

[0161] The present disclosure embodiment also provides a near-eye display device, including: an image source for outputting image light; the eyepiece system 10 described in the above embodiment, which is arranged in the light output direction of the image source.

[0162] Among them, the near-eye display device can be an AR glasses, a VR helmet, etc. The image source can be the above-mentioned micro display screen, or other displays with display functions.

[0163] Combined with the eyepiece system 10 described in the above embodiment, by reducing the total system length TL of the eyepiece system 10, while realizing the miniaturization of the eyepiece system 10, the miniaturization of the near-eye display device is realized. In addition, combined with the high refractive index, central thickness, curvature radii of the image side and object side of each lens included in the eyepiece system 10, it is ensured that the eyepiece system 10 has good imaging quality, so as to ensure that the near-eye display device realizes high-quality imaging.

[0164] Those skilled in the art will readily think of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include well-known knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the appended claims.

Claims

1. An eyepiece system, wherein: Applied to a near-eye display device, the eyepiece system comprises: A plurality of lenses arranged in sequence along the same optical axis from the image side to the object side, the refractive index of the plurality of lenses being greater than 1.65, and the total length of the system of the plurality of lenses along the main optical axis being less than or equal to 25 mm; The plurality of lenses include: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, which are arranged in sequence along the same optical axis from the image side to the object side; the first lens, the second lens, the third lens, the fifth lens and the seventh lens are all positive power lenses, and the fourth lens and the sixth lens are both negative power lenses; The refractive index of the first lens is greater than or equal to 1.72 and less than or equal to 1.74; the refractive index of the second lens is greater than or equal to 1.78 and less than or equal to 1.84; the refractive index of the third lens is greater than or equal to 1.65 and less than or equal to 1.80; the refractive index of the fourth lens is greater than or equal to 1.80 and less than or equal to 1.95; the refractive index of the fifth lens is greater than or equal to 1.75 and less than or equal to 1.80; the refractive index of the sixth lens and the refractive index of the seventh lens are both greater than or equal to 1.70 and less than or equal to 1.80; The Abbe number of the first lens and the Abbe number of the third lens are both greater than or equal to 45 and less than or equal to 60; the Abbe number of the second lens and the Abbe number of the fifth lens are both greater than or equal to 40 and less than or equal to 50; the Abbe number of the fourth lens, the Abbe number of the sixth lens, and the Abbe number of the seventh lens are all greater than or equal to 20 and less than or equal to 30.

2. The eyepiece system of claim 1, wherein: The plurality of lenses are arranged along the same straight line direction.

3. The eyepiece system of claim 1, wherein: The focal length of the eyepiece system is greater than or equal to 50 m -1 , and less than or equal to 65m -1 .

4. The eyepiece system according to any one of claims 1 to 3, wherein: The first lens has a convex image side surface and a concave or flat object side surface; The second lens has a convex image-side surface and a concave object-side surface; The third lens has a convex image-side surface and a concave object-side surface; The fourth lens has a convex image-side surface and a concave object-side surface; a fifth lens having an image-side surface which is convex and an object-side surface which is convex, or having an image-side surface which is convex and an object-side surface which is flat; The sixth lens has a concave image-side surface and a convex object-side surface; The seventh lens has an image-side surface that is convex and an object-side surface that is concave; or an image-side surface that is flat and an object-side surface that is convex.

5. The eyepiece system of claim 1, wherein: The image side surfaces and object side surfaces of the plurality of lenses are spherical surfaces; or, The image side surface and the object side surface of the first lens, the object side surface of the second lens, the image side surface and the object side surface of the third lens, the image side surface and the object side surface of the fourth lens, the image side surface and the object side surface of the fifth lens, the image side surface and the object side surface of the sixth lens, and the object side surface of the seventh lens are all spherical surfaces, and the image side surface of the second lens and the image side surface of the seventh lens are both aspherical surfaces; or, The image side surface and the object side surface of the first lens, the object side surface of the second lens, the image side surface and the object side surface of the third lens, the image side surface and the object side surface of the fourth lens, the image side surface and the object side surface of the fifth lens, the object side surface of the sixth lens, and the object side surface of the seventh lens are all spherical surfaces, and the image side surface of the second lens, the image side surface of the sixth lens, and the image side surface of the seventh lens are all aspherical surfaces.

6. The eyepiece system of claim 1, wherein: The central thickness of the first lens is greater than or equal to 2.6 mm and less than or equal to 3.4 mm; The central thickness of the second lens is greater than or equal to 1.4 mm and less than or equal to 2.1 mm; The central thickness of the third lens is greater than or equal to 2.4 mm and less than or equal to 3.5 mm; The central thickness of the fourth lens is greater than or equal to 1.3 mm and less than or equal to 1.6 mm; The central thickness of the fifth lens is greater than or equal to 1.7 mm and less than or equal to 2.4 mm; The central thickness of the sixth lens is greater than or equal to 0.5 mm and less than or equal to 2.4 mm; The central thickness of the seventh lens is greater than or equal to 1.8 mm and less than or equal to 3.8 mm.

7. The eyepiece system of claim 1, wherein: The radius of curvature of the image side surface of the first lens is greater than or equal to 10 mm and less than or equal to 20 mm, and the radius of curvature of the object side surface is greater than or equal to 30 mm; The radius of curvature of the image side surface of the second lens is greater than or equal to 5 mm and less than or equal to 20 mm, and the radius of curvature of the object side surface is greater than or equal to 5 mm and less than or equal to 25 mm; The radius of curvature of the image side surface of the third lens is greater than or equal to 5 mm and less than or equal to 15 mm, and the radius of curvature of the object side surface is greater than or equal to 15 mm and less than or equal to 55 mm; The radius of curvature of the image side surface of the fourth lens is greater than or equal to 15 mm and less than or equal to 55 mm, and the radius of curvature of the object side surface is less than or equal to 10 mm; The curvature radius of the image side surface of the fifth lens is greater than or equal to 5 mm and less than or equal to 110 mm, and the curvature radius of the object side surface is greater than or equal to 10 mm; The image side surface of the sixth lens has a radius of curvature less than or equal to 50 mm, and the object side surface has a radius of curvature greater than or equal to 10 mm and less than or equal to 40 mm; The radius of curvature of the image side surface of the seventh lens is greater than or equal to 5 mm, and the radius of curvature of the object side surface is greater than or equal to 10 mm and less than or equal to 50 mm.

8. The eyepiece system of claim 7, wherein: The object side surface of the third lens and the image side surface of the fourth lens are both spherical surfaces with the same radius of curvature; The object side surface of the third lens and the image side surface of the fourth lens are bonded together by optical glue.

9. The eyepiece system according to any one of claims 1 to 3, wherein: The lens is made of glass or resin.

10. A near-eye display device, wherein: include: An image source, used to output image light; The eyepiece system described in any one of claims 1 to 9 is arranged in the light emitting direction of the image source.

Images