Optical lens assembly and head-mounted device

Abstract

An optical lens assembly and a head-mounted device, the optical lens assembly includes five lenses, the five lenses are sequentially a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an enlargement side to a reduction side. Each lens has an enlargement side surface facing an enlargement side direction and a reduction side surface facing a reduction side direction. The second lens enlargement side surface near an optical axis is concave. At least one surface of at least one of the five lenses includes at least one inflection point. When certain conditions are met, better image brightness and sufficient mechanical configuration space can be provided.

Description

Technical Field

[0001] This disclosure relates to an optical lens assembly, and more particularly to a miniaturized optical lens assembly for use in a head-mounted device. Background Technology

[0002] With the rapid development of technology, electronic devices equipped with optical lenses are being used in a wider range of applications, and the requirements for optical lenses are becoming more diverse. Since it is not easy for traditional optical lenses to achieve a balance between requirements such as image quality, sensitivity, aperture size, size, or viewing angle, this invention provides an optical lens to meet these requirements. Summary of the Invention

[0003] This disclosure provides an optical lens assembly and a head-mounted device that can provide a wider field of view, better image brightness, and sufficient space for mechanical configuration.

[0004] This disclosure provides an optical lens assembly comprising five lenses, which are sequentially arranged from magnification side to reduction side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Each lens has a magnifying surface facing the magnification direction and a reduction surface facing the reduction direction. The magnifying surface of the second lens is concave near the optical axis. At least one surface of at least one of the five lenses includes at least one inflection point. The optical lens assembly further includes an aperture, the distance from the aperture to the reduction-side conjugate surface on the optical axis being SL, the radius of curvature of the magnifying surface of the second lens being R3, the radius of curvature of the reduction-side surface of the second lens being R4, the distance from the magnifying surface of the first lens to the reduction-side conjugate surface on the optical axis being TL, the thickness of the second lens on the optical axis being CT2, the thickness of the third lens on the optical axis being CT3, the thickness of the fourth lens on the optical axis being CT4, and the minimum thickness of all lenses in the optical lens assembly on the optical axis being CTmin. The distance on the optical axis from the reducing side surface to the reducing side conjugate surface of the five lenses is BL. The effective diameter of the aperture of the optical lens group is Ds. The maximum image height of the optical lens group is ImgH. The optical axis spacing between the first and second lenses is T12. The optical axis spacing between the second and third lenses is T23. The optical axis spacing between the third and fourth lenses is T34. The optical axis spacing between the fourth and fifth lenses is T45. These conditions must satisfy the following conditions: (R3+R4) / (R3-R4) < 0.50; 0.98 < SL / TL < 2.50; 0.65 < CT2 / CT4 < 4.50; 3.80 < CT3 / CTmin < 10.0; 0.55 < CT3 / BL; 0.70 < Ds / ImgH < 3.0; and 0.25 < T12 / (T23+T34+T45) < 4.0.

[0005] This disclosure provides an optical lens assembly comprising five lenses, which are sequentially arranged from the magnifying side to the reducing side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Each lens has a magnifying side surface facing the magnifying side direction and a reducing side surface facing the reducing side direction. The second lens has a concave surface near the optical axis on its magnifying side surface. The third lens has a convex surface near the optical axis on its magnifying side surface. At least one lens in the optical lens assembly has at least one inflection point on at least one magnifying side surface or reducing side surface. The optical lens group also includes an aperture, the distance from the aperture to a conjugate surface on the narrowing side along the optical axis is SL, the radius of curvature of the magnifying side surface of the second lens is R3, the radius of curvature of the narrowing side surface of the second lens is R4, the distance from the magnifying side surface of the first lens to its conjugate surface on the optical axis is TL, the thickness of the first lens on the optical axis is CT1, the thickness of the second lens on the optical axis is CT2, the thickness of the third lens on the optical axis is CT3, the thickness of the fourth lens on the optical axis is CT4, the thickness of the fifth lens on the optical axis is CT5, the spacing between the first and second lenses on the optical axis is T12, the maximum spacing between all adjacent lenses in the optical lens group on the optical axis is ATmax, the maximum distance between the optically effective area of ​​the magnifying side surface of the first lens and the optical axis is Y11, the maximum distance between the optically effective area of ​​the narrowing side surface of the fifth lens and the optical axis is Y52, the effective diameter of the aperture of the optical lens group is Ds, and the maximum image height of the optical lens group is ImgH, which satisfies the following condition: (R3+R4) / (R3-R4) < 0.25; 0.98 < SL / TL < 2.50; 0.40 < CT2 / CT4 < 4.50; 0 < CT1 / CT3 < 1.50; 3.0 < CT3 / CT5 < 7.0; 0.90 < CT2 / T12 < 5.0; 0.60 < T12 / ATmax ≤ 1.0; 0.65 < Y11 / Y52 < 1.50; and 1.0 < Ds / ImgH < 3.0.

[0006] According to this disclosure, a head-mounted device is provided, comprising an image display system. The image display system can be divided into two sides, each side comprising a projection module and an image transmission module. Each projection module includes at least one projection lens group, which includes the aforementioned optical lens group and an image source.

[0007] This disclosure provides a head-mounted device comprising a light field imaging display system. The light field imaging display system is divided into two sides, each side comprising a projection module and an image transmission module. The projection module comprises at least three projection lens groups, each comprising the aforementioned optical lens group and an image source, wherein the fifth lens is a final lens. At least one lens in each optical lens group is made of plastic and has an aspherical surface. Each optical lens group also includes an aperture, the distance on the optical axis from the magnifying surface of the first lens to the reducing surface of the final lens is TD, and the aperture value of the optical lens group is Fno, which satisfies the following conditions: 1.0 mm < TD < 30.0 mm; and 0.80 < Fno < 2.50.

[0008] When (R3+R4) / (R3-R4) satisfies the above conditions, it is beneficial to move the aperture closer to the magnification side to meet the mechanical design of the electronic device.

[0009] When SL / TL meets the above conditions, the aperture position of the system can be balanced to provide sufficient space for the mechanism.

[0010] When CT2 / CT4 meet the above conditions, the center thickness of the second and fourth lenses can be balanced to improve manufacturing yield.

[0011] When CT3 / CTmin meets the above conditions, it can be ensured that the third lens has sufficient thickness to provide the main refractive force of the optical lens group.

[0012] When the CT3 / BL meets the above conditions, the back focal length of the optical lens group can be effectively controlled to avoid the device from becoming too large.

[0013] When Ds / ImgH meets the above conditions, the range of light entering and exiting the optical lens group can be effectively increased, thereby increasing the image brightness.

[0014] When T12 / (T23+T34+T45) satisfies the above conditions, it can ensure that there is sufficient optical path adjustment space between the first lens and the second lens to reduce the angle between the principal ray and the conjugate surface on the narrowing side.

[0015] When CT1 / CT3 meet the above conditions, the excessive thickness of the center of the first lens can be avoided, thus limiting the field of view.

[0016] When CT3 / CT5 meets the above conditions, the control capability of the third lens in the optical lens group can be enhanced, and the fifth lens can be made into a correction lens to correct off-axis aberrations.

[0017] When CT2 / T12 meets the above conditions, the proportional relationship between the second lens itself and its space can be balanced to simultaneously satisfy manufacturability and yield.

[0018] When T12 / ATmax meets the above conditions, it can be ensured that the first lens and the second lens have sufficient space to facilitate the adjustment of the optical path.

[0019] When Y11 / Y52 meets the above conditions, it can facilitate the optical path reversal of the optical lens group, thereby reducing the angle between the principal ray and the conjugate surface on the narrowing side.

[0020] When TD meets the above conditions, it can ensure the miniaturization of the optical lens group, which is beneficial for its application in various electronic devices.

[0021] When Fno meets the above conditions, the amount of light passing through the optical lens group can be controlled, thereby increasing the image brightness. Attached Figure Description

[0022] Figure 1 A schematic diagram illustrating an optical lens assembly according to a first embodiment of the present disclosure;

[0023] Figure 2 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the first embodiment.

[0024] Figure 3 A schematic diagram illustrating an optical lens assembly according to a second embodiment of the present disclosure;

[0025] Figure 4 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the second embodiment.

[0026] Figure 5 A schematic diagram illustrating an optical lens assembly according to a third embodiment of the present disclosure;

[0027] Figure 6 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the third embodiment.

[0028] Figure 7 A schematic diagram illustrating an optical lens assembly according to the fourth embodiment of this disclosure;

[0029] Figure 8 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the fourth embodiment.

[0030] Figure 9 A schematic diagram illustrating an optical lens assembly according to the fifth embodiment of this disclosure;

[0031] Figure 10 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the fifth embodiment.

[0032] Figure 11 A schematic diagram illustrating an optical lens assembly according to the sixth embodiment of this disclosure;

[0033] Figure 12 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the sixth embodiment.

[0034] Figure 13 A schematic diagram illustrating an optical lens assembly according to the seventh embodiment of this disclosure;

[0035] Figure 14 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the seventh embodiment.

[0036] Figure 15 A schematic diagram illustrating an optical lens assembly according to the eighth embodiment of this disclosure;

[0037] Figure 16 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the eighth embodiment.

[0038] Figure 17 A schematic diagram illustrating an optical lens assembly according to the ninth embodiment of this disclosure;

[0039] Figure 18 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the ninth embodiment.

[0040] Figure 19 A schematic diagram illustrating the configuration of the superlens in the optical lens group according to the fifth embodiment of this disclosure;

[0041] Figure 20A A perspective view of a head-mounted device according to the tenth embodiment of this disclosure is shown;

[0042] Figure 20B Drawing according to Figure 20A A schematic diagram of the head-mounted device;

[0043] Figure 21 A system schematic diagram of a head-mounted device according to the eleventh embodiment of this disclosure is shown;

[0044] Figure 22A A system schematic diagram illustrating a head-mounted device according to the twelfth embodiment of this disclosure; and

[0045] Figure 22B It is a drawing according to Figure 22A A schematic diagram of the projection module in the head-mounted device.

[0046] [Symbol Explanation]

[0047] 100, 200, 300: Head-mounted devices

[0048] 110: Image display system

[0049] 310: Light Field Imaging Display System

[0050] 101, 201, 301: Users

[0051] 111, 211, 311: Projection modules

[0052] 311a: Projection lens assembly

[0053] 1, 2, 3, 4, 5, 6, 7, 8, 9, 1111, 3111: Optical lens group

[0054] 1112, 3112: Image source

[0055] 112, 212, 312: Image transmission modules

[0056] 2121: Optical path conversion element

[0057] ST: Aperture

[0058] E1: First lens

[0059] E2: Second lens

[0060] E3: Third Lens

[0061] E4: Fourth Lens

[0062] E5: Fifth Lens

[0063] E6: Filter element

[0064] E7: Super Lens

[0065] RCS: Reducing Lateral Conjugate Surface

[0066] OA1: First optical axis

[0067] OA2: Second optical axis

[0068] OA3: Third optical axis

[0069] LF, LF1, LF2: Optical path switching elements

[0070] LG: Lens Group Detailed Implementation

[0071] With advancements in stereoscopic display technology, and to overcome user discomfort caused by common stereoscopic display technologies (such as the inability of display devices to simulate the muscle contractions and eye movements required for stereoscopic vision), the industry is now employing light field technology to improve the observer's visual experience. However, to balance the size limitations of existing light field technology, smaller optical lenses with larger apertures are designed to achieve better stereoscopic display effects within a limited space.

[0072] This disclosure provides an optical lens assembly comprising five lenses, which are arranged sequentially from the magnifying side to the reducing side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; each lens has a magnifying side surface facing the magnifying side direction and a reducing side surface facing the reducing side direction. The fifth lens may be the last lens in the optical lens assembly, but this disclosure is not limited thereto.

[0073] The first lens can have positive refractive power, which facilitates the aperture to move towards the magnification side, ensuring that more light is received and improving image brightness. The magnification side surface of the first lens can be convex near the optical axis, and the reduction side surface of the first lens can also be convex near the optical axis. This effectively distributes the refractive power of the lens surface, avoiding excessive curvature on a single surface.

[0074] The second lens can have negative refractive power, which helps to receive light with a wide angle of view and optimize light at different wavelengths. The magnifying side surface of the second lens can be concave near the optical axis, which helps to expand the image viewing angle. The constricting side surface of the second lens can be convex near the optical axis, thereby limiting the incident angle of light and avoiding total internal reflection.

[0075] The third lens can have positive refractive power, providing the main converging power of the optical lens group to avoid excessive overall length. The magnifying side surface of the third lens can be convex near the optical axis, which facilitates control of the optical path of the optical lens group, reducing the angle between the principal ray and the conjugate surface on the reducing side. The reducing side surface of the third lens is also convex near the optical axis, thereby improving the symmetry of the optical lens group and optimizing image quality.

[0076] The fourth lens can have negative refractive power, which can balance the aberrations produced by the third lens to improve image quality. The magnifying side surface of the fourth lens can be concave near the optical axis, which can complement the third lens. The reducing side surface of the fourth lens can be convex near the optical axis, which can balance the aberrations of the optical lens group.

[0077] The fifth lens can have negative refractive power, which can balance the viewing angle of the optical lens group to meet the practical characteristics of the device. The narrowing side surface of the fifth lens near the optical axis can be concave, thereby controlling the back focal length of the optical lens group to avoid excessive size.

[0078] In an optical lens group, at least one magnifying or reducing surface of at least one lens includes at least one inflection point. This facilitates the correction of peripheral aberrations while avoiding a reduction in peripheral image brightness. Specifically, at least one surface of the third lens may include at least one inflection point, which controls the angle of light refraction and reduces stray light generation. At least one surface of the fourth lens may include at least one inflection point, which corrects coma and astigmatism. At least one surface of the fifth lens may include at least one inflection point, which facilitates distortion correction.

[0079] The optical lens group may further include an aperture. The distance from the aperture to the conjugate plane on the reducing side along the optical axis is SL, and the distance from the magnifying side surface of the first lens to the conjugate plane on the reducing side along the optical axis is TL, which satisfy the following conditions: 0.95 < SL / TL < 4.0. Thereby, it can ensure that light can be fully utilized to enhance the image brightness. Additionally, it can also satisfy the following conditions: 0.98 < SL / TL < 2.50. Moreover, it can also satisfy the following conditions: 1.0 ≤ SL / TL < 1.80.

[0080] The radius of curvature of the magnifying side surface of the second lens is R3, and the radius of curvature of the reducing side surface of the second lens is R4, which satisfy the following conditions: (R3 + R4) / (R3 - R4) < 0.50. Thereby, it is beneficial for the aperture to approach the magnifying side direction to meet the mechanical design of the electronic device. Additionally, it can also satisfy the following conditions: (R3 + R4) / (R3 - R4) < 0.25. Moreover, it can also satisfy the following conditions: -10.0 < (R3 + R4) / (R3 - R4) < 0.25. Moreover, it can also satisfy the following conditions: -10.0 < (R3 + R4) / (R3 - R4) < 0. Moreover, it can also satisfy the following conditions: -10.0 < (R3 + R4) / (R3 - R4) < -1.0.

[0081] The thickness of the second lens along the optical axis is CT2, and the thickness of the fourth lens along the optical axis is CT4, which satisfy the following conditions: 0.40 < CT2 / CT4 < 9.0. Thereby, it can balance the central thicknesses of the second lens and the fourth lens to improve the manufacturing yield. Additionally, it can also satisfy the following conditions: 0.65 < CT2 / CT4 < 4.50. Moreover, it can also satisfy the following conditions: 0.85 < CT2 / CT4 < 2.50.

[0082] The thickness of the third lens along the optical axis is CT3, and the minimum value of the thicknesses of all lenses in the optical lens group along the optical axis is CTmin, which satisfy the following conditions: 1.60 < CT3 / CTmin < 10.0. Thereby, it can ensure that the third lens has sufficient thickness to provide the main refractive power of the optical lens group. Additionally, it can also satisfy the following conditions: 2.20 < CT3 / CTmin < 7.0. Moreover, it can also satisfy the following conditions: 3.80 < CT3 / CTmin < 7.0.

[0083] The thickness of the third lens along the optical axis is CT3, and the distance from the reducing side surface of the fifth lens to the conjugate plane on the reducing side along the optical axis is BL, which satisfy the following conditions: 0.55 < CT3 / BL. Thereby, it can effectively control the back focal length of the optical lens group to avoid the device volume from being too large.

[0084] The effective diameter of the aperture of the optical lens group is Ds, and the maximum image height of the optical lens group is ImgH, which satisfies the following condition: 0.70 < Ds / ImgH < 3.0. This effectively increases the range of light entering and exiting the optical lens group, thereby increasing image brightness. Additionally, it also satisfies the following condition: 1.0 < Ds / ImgH < 2.0.

[0085] The optical axis spacing between the first and second lenses is T12, between the second and third lenses is T23, between the third and fourth lenses is T34, and between the fourth and fifth lenses is T45. This spacing satisfies the condition: 0.25 < T12 / (T23+T34+T45) < 9.0. This ensures sufficient optical path adjustment space between the first and second lenses to reduce the angle between the principal ray and the conjugate plane on the narrowing side. Additionally, it also satisfies the condition: 0.45 < T12 / (T23+T34+T45) < 4.0.

[0086] The thickness of the first lens along the optical axis is CT1, and the thickness of the third lens along the optical axis is CT3, satisfying the following condition: 0 < CT1 / CT3 < 1.50. This avoids the first lens's center thickness being too large, thus limiting the viewing angle. Additionally, it also satisfies the following condition: 0.25 < CT1 / CT3 < 0.90.

[0087] The thickness of the third lens on the optical axis is CT3, and the thickness of the fifth lens on the optical axis is CT5, satisfying the following condition: 1.20 < CT3 / CT5 < 9.0. This enhances the control capability of the third lens within the optical lens group, while simultaneously making the fifth lens a corrective lens to correct off-axis aberrations. Additionally, it also satisfies the following condition: 3.0 < CT3 / CT5 < 7.0.

[0088] The thickness of the second lens on the optical axis is CT2, and the distance between the first and second lenses on the optical axis is T12, satisfying the following condition: 0.90 < CT2 / T12 < 5.0. This balances the proportional relationship between the second lens itself and its space, simultaneously satisfying manufacturability and yield. Additionally, it also satisfies the following condition: 1.0 < CT2 / T12 < 3.0.

[0089] The distance between the first lens and the second lens on the optical axis is T12, and the maximum value of the distances between all adjacent lenses in the optical lens group on the optical axis is ATmax, which satisfies the following condition: 0.45 < T12 / ATmax ≤ 1.0. Thereby, it can ensure that the first lens and the second lens have sufficient space to facilitate the adjustment of the optical path. Additionally, it can satisfy the following condition: 0.60 < T12 / ATmax ≤ 1.0. Moreover, it can satisfy the following condition: 0.80 < T12 / ATmax ≤ 1.0.

[0090] The maximum distance between the optical effective area of the magnifying side surface of the first lens and the optical axis is Y11, and the maximum distance between the optical effective area of the reducing side surface of the fifth lens and the optical axis is Y52, which satisfies the following condition: 0.45 < Y11 / Y52 < 2.0. Thereby, it can facilitate the turning of the optical path of the optical lens group to reduce the angle between the chief ray and the reducing side conjugate surface. Additionally, it can satisfy the following condition: 0.65 < Y11 / Y52 < 1.50.

[0091] The perpendicular distance between the inflection point closest to the optical axis on the magnifying side surface or the reducing side surface of the third lens and the optical axis is Yc3, and the focal length of the optical lens group is f, which satisfies the following condition: 0.05 < Yc3 / f < 5.0. Thereby, it can help correct the field curvature, meet the miniaturization characteristics, and make the Petzval surface of the optical lens group flatter. In addition, the perpendicular distance between the inflection point closest to the optical axis on the magnifying side surface or the reducing side surface of the fourth lens and the optical axis is Yc4, and the focal length of the optical lens group is f, which can satisfy the following condition: 0.05 < Yc4 / f < 5.0. In addition, the perpendicular distance between the inflection point closest to the optical axis on the magnifying side surface or the reducing side surface of the last lens and the optical axis is Yc5, and the focal length of this optical lens group is f, which can satisfy the following condition: 0.05 < Yc5 / f < 5.0. Thereby, it can further correct the field curvature and meet the miniaturization characteristics.

[0092] The minimum value of the Abbe numbers of all lenses in the optical lens group is Vdmin, which satisfies the following condition: 5.0 < Vdmin < 21.0. Thereby, it can help the optical lens group correct the chromatic aberration ability. Additionally, it can satisfy the following condition: 5.0 < Vdmin < 20.0.

[0093] The maximum value of the refractive indices of all lenses in the optical lens group is Nmax, which satisfies the following condition: 1.70 < Nmax < 1.80. Thereby, it can increase the system control ability of the said lens to achieve good imaging quality in a limited space.

[0094] The aperture value of the optical lens group is Fno, which satisfies the following condition: 0.80 < Fno < 2.0. This allows control over the amount of light passing through the optical lens group, thereby increasing image brightness. Additionally, it satisfies the following condition: 0.80 < Fno < 2.50. Furthermore, it satisfies the following condition: 0.80 < Fno < 1.85.

[0095] The third lens can contain the largest effective diameter of all the lenses. This allows for a balance between the lens sizes on the magnifying and reducing sides of the optical lens group, making it more symmetrical.

[0096] The Abbe number of the fifth lens is V5, which satisfies the following condition: 10.0 < V5 < 50.0. This gives the fifth lens strong optical path control and balances the aberrations of the optical lens group. Additionally, it can also satisfy the following condition: 10.0 < V5 < 25.0. Furthermore, it can also satisfy the following condition: 10.0 < V5 < 20.0.

[0097] The optical lens group has a focal length of f, with the first lens having a focal length of f1, the second lens having a focal length of f2, and the third lens having a focal length of f3. These focal lengths satisfy the following condition: 0.10 < (|f / f1|+|f / f2|) / |f / f3| < 1.70. This allows for effective control of the refractive power configuration at the magnification end of the optical lens group, thereby enhancing the weight distribution of the third lens.

[0098] The maximum value of the principal ray angle among all principal ray angles in the optical lens group is CRAmax, which satisfies the following condition: 0 ≤ CRAmax < 22.0. This mitigates the angle between the principal ray and the conjugate plane on the narrowing side, ensuring the brightness of the peripheral image.

[0099] At least one lens in the optical lens group can be made of plastic and has an aspherical surface. This effectively reduces production costs, increases design freedom, facilitates the optimization of off-axis aberrations, and aids in mass production. Additionally, at least three lenses in the optical lens group can be made of plastic.

[0100] At least one lens in the optical lens group can be made of glass. This improves the heat resistance of the optical lens group, allowing it to adapt to different environmental conditions.

[0101] The absolute value of the focal length of the third lens is the smallest of the absolute values ​​of the focal lengths of all lenses in the optical lens group. This improves the symmetry of the refractive power of the optical lens group, which is beneficial for correcting aberrations.

[0102] The distance between the first and second lenses on the optical axis can be the largest among all the distances between adjacent lenses. This allows for effective control of light rays with a wide angle of view, facilitating a larger range of light entering and exiting.

[0103] The distance TD along the optical axis from the magnifying side surface of the first lens to the reducing side surface of the last lens satisfies the following condition: 0.50 mm < TD < 50.0 mm. This ensures the miniaturization of the optical lens assembly, facilitating its application in various electronic devices. Furthermore, it also satisfies the following conditions: 1.0 mm < TD < 30.0 mm. Moreover, it also satisfies the following conditions: 2.0 mm < TD < 15.0 mm. Furthermore, it also satisfies the following conditions: 3.0 mm < TD < 9.0 mm.

[0104] The distance along the optical axis from the magnifying side surface of the first lens to the shrinking side surface of the last lens is TD. The sum of the thicknesses of all lenses in the optical lens group along the optical axis is ΣCT, which satisfies the following condition: 1.0 < TD / ΣCT < 1.40. This improves the space utilization of the optical lens group while achieving miniaturization.

[0105] The effective diameter of the aperture of the optical lens group is Ds, and the distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the last lens is TD, which satisfies the following condition: 0.45 < Ds / TD < 1.0. This allows for an increase in the amount of light emitted by the optical lens group while controlling its overall size.

[0106] In an optical lens group, at least three lenses have an Abbe number greater than 10.0 and less than 50.0. This ensures that the lens material in the optical lens group has sufficient ability to control light, balancing the focusing positions of light at different wavelengths and preventing image overlap. Additionally, at least four lenses in the optical lens group have an Abbe number greater than 10.0 and less than 50.0.

[0107] The various technical features in the optical lens assembly disclosed above can be combined and configured to achieve the corresponding effects.

[0108] It must be noted that when the optical lens group is a projection lens group, the conjugate surface on the narrowing side is an image source; when the optical lens group is an imaging lens group, the conjugate surface on the narrowing side is an imaging surface.

[0109] The optical lens assembly disclosed herein can be made of glass or plastic. If the lens is made of glass, the flexibility in configuring the refractive power of the optical lens assembly is increased, and glass lenses can be manufactured using techniques such as grinding or molding. If the lens is made of plastic, production costs can be effectively reduced. Furthermore, spherical or aspherical (ASP) surfaces can be incorporated into the lens surface. Spherical lenses reduce manufacturing difficulty, while aspherical surfaces provide more controllable variables to reduce aberrations, decrease the number of lenses, and effectively reduce the overall length of the optical lens assembly disclosed herein. Aspherical surfaces can be manufactured using methods such as plastic injection molding or molding glass lenses.

[0110] The optical lens assembly disclosed herein allows for the selective addition of additives to any (or more) lens materials to produce light absorption or interference effects, thereby altering the lens's transmittance for specific wavelengths of light and reducing stray light and color shift. For example, the additives may filter out light in the 600nm-800nm ​​wavelength range to reduce excess red or infrared light; or they may filter out light in the 350nm-450nm wavelength range to reduce blue or ultraviolet light. Therefore, the additives prevent specific wavelengths of light from interfering with imaging. Furthermore, the additives can be uniformly mixed into plastic and manufactured into lenses using injection molding technology. Additionally, the additives can also be deposited on the lens surface to provide the aforementioned effects.

[0111] In the optical lens group provided in this disclosure, if the lens surface is aspherical, it means that the entire or a portion of the optically effective area of ​​the lens surface is aspherical.

[0112] In the optical lens assembly provided in this disclosure, if the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface can be convex near the optical axis; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface can be concave near the optical axis. In the optical lens assembly provided in this disclosure, if the lens has positive or negative refractive power, or the focal length of the lens, it can refer to the refractive power or focal length of the lens near the optical axis.

[0113] In the optical lens group disclosed herein, the inflection point is the intersection of the positive and negative changes in the curvature of the lens surface.

[0114] The conjugate surface of the optical lens group disclosed herein can be a plane or a curved surface with any curvature, depending on the corresponding electronic photosensitive element, particularly a curved surface with a concave surface facing the object side. Furthermore, when the optical lens group of this disclosure is used as an imaging optical system, one or more imaging correction elements (such as planar elements) can be selectively arranged between the lens closest to the conjugate surface and the conjugate surface in the imaging optical path to achieve image correction (such as image curvature). The optical properties of the imaging correction element, such as curvature, thickness, refractive index, position, and surface shape (convex or concave, spherical or aspherical, diffractive surface, and Fresnel surface, etc.), can be adjusted according to the requirements of the imaging device. Generally, a preferred configuration of the imaging correction element is to place a thin plano-concave element with a concave surface facing the object side near the optical lens group.

[0115] In addition, the optical lens assembly provided in this disclosure may include at least one aperture stop, such as an aperture stop, glare stop, or field stop, which helps to reduce stray light and improve image quality.

[0116] In the optical lens assembly disclosed herein, the aperture configuration can be either a front aperture or a central aperture. A front aperture means the aperture is positioned between the magnifying side and the first lens, while a central aperture means the aperture is positioned between the first lens and the conjugate surface of the reducing side. A front aperture allows for a longer distance between the exit pupil of the optical lens assembly and the conjugate surface of the reducing side, resulting in a telecentric effect and increasing the image reception efficiency of the CCD or CMOS sensor. A central aperture helps to expand the field of view of the optical lens assembly, giving it the advantages of a wide-angle lens.

[0117] This disclosure may appropriately incorporate a variable aperture element, which can be a mechanical component or a light-regulating element, capable of electrically or signal-controlled aperture size and shape. The mechanical component may include movable parts such as blade assemblies or shielding plates; the light-regulating element may include masking materials such as filter elements, electrochromic materials, or liquid crystal layers. The variable aperture element can enhance image adjustment capabilities by controlling the amount of light entering the image or the exposure time. Furthermore, the variable aperture element can also be the aperture of this disclosure, allowing adjustment of image quality, such as depth of field or exposure speed, by changing the aperture value.

[0118] The optical lens group disclosed herein can also be applied in various electronic devices such as three-dimensional (3D) image capture, digital cameras, mobile products, digital tablets, smart TVs, network monitoring equipment, motion-sensing game consoles, dashcams, reversing cameras, wearable products, and drones.

[0119] This disclosure provides a head-mounted device comprising an image display system. The image display system may be divided into two sides, each side comprising a projection module and an image transmission module. Each projection module includes at least one projection lens group, which may include the aforementioned optical lens group and an image source.

[0120] This disclosure provides a head-mounted device comprising a light field imaging display system. The light field imaging display system can be divided into two sides, each side comprising a projection module and an image transmission module. Each projection module includes at least three projection lens groups, each projection lens group comprising an optical lens group and an image source. The optical lens group comprises at least three lenses, which sequentially include a first lens and a last lens from the magnification side to the reduction side. At least one lens in all the lenses of the optical lens group is made of plastic and has an aspherical surface. The optical lens groups in the head-mounted device can be the aforementioned optical lens groups or optical lens groups that satisfy any of the aforementioned conditions, but are not limited thereto.

[0121] Each projection module may contain at least three projection lens groups, which can provide information on different focus positions, allowing users to adapt more naturally to the distance of the image. In addition, the projection module may also contain a single projection lens group, and this disclosure is not limited thereto.

[0122] In a head-mounted device, the image transmission module can be a waveguide element. This allows images to be transmitted within a limited space, achieving a lightweight design. Alternatively, the image transmission module can also be an optical path deflection mirror assembly, but this disclosure is not limited to this.

[0123] Each projection lens assembly may include an element with a metasurface. This allows for optical path control within a very small space. Specifically, a metasurface is an optical design structure that controls light and electromagnetic wave characteristics (such as phase, amplitude, and polarization) at a subwavelength scale. This structure effectively expands the modulation range of the optical refractive index while maintaining an ultra-thin volume; it can specifically be a metalens.

[0124] Furthermore, the projection module on one side of the light field imaging display system contains between five and fifteen projection lenses. This allows for a balance between device lightweighting and light field imaging quality.

[0125] The image source may be DLP or LCD, but this disclosure is not limited thereto. This allows for sufficient brightness and quality in the projected image.

[0126] Based on the above implementation methods, specific embodiments are presented below and described in detail with reference to the accompanying drawings.

[0127] <First Embodiment>

[0128] Please refer to Figure 1 as well as Figure 2 ,in Figure 1 A schematic diagram of an optical lens assembly 1 according to a first embodiment of the present disclosure is shown. Figure 2 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the first embodiment. Figure 1 It is understood that the optical lens group 1 of the first embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction side conjugate surface RCS. The optical lens group 1 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0129] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is concave near the optical axis, both of which are aspherical. In addition, the reducing side surface of the first lens contains a point of inflection.

[0130] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis. Both are aspherical.

[0131] The third lens E3 has positive refractive power and is made of glass. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the third lens contains a point of inflection.

[0132] The fourth lens E4 has positive refractive power and is made of glass. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the fourth lens each contain a point of inflection.

[0133] The fifth lens, E5, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is also concave near the optical axis; both are aspherical. Additionally, the magnifying side surface of the fifth lens contains a point of inflection.

[0134] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 1.

[0135] The equations for the aspherical surfaces of the above lenses are expressed as follows:

[0136]

[0137] in:

[0138] X: The displacement parallel to the optical axis from the intersection of the aspherical surface and the optical axis to a point on the aspherical surface at a distance Y from the optical axis;

[0139] Y: The perpendicular distance between a point on the aspherical curve and the optical axis;

[0140] R: Radius of curvature;

[0141] k: cone coefficient; and

[0142] Ai: The i-th order aspherical coefficient.

[0143] In the optical lens group 1 of the first embodiment, the focal length of the optical lens group 1 is f, the aperture value (f-number) of the optical lens group 1 is Fno, and half of the maximum field of view in the optical lens group 1 is HFOV, with the following values: f = 7.20 mm; Fno = 1.49; and HFOV = 22.5 degrees.

[0144] In the optical lens group 1 of the first embodiment, the refractive index of the first lens E1 is N1, the refractive index of the second lens E2 is N2, the refractive index of the third lens E3 is N3, the refractive index of the fourth lens E4 is N4, and the refractive index of the fifth lens E5 is N5. The maximum value of the refractive index of all lenses in the optical lens group 1 is Nmax, which satisfies the following condition: Nmax = 1.744; wherein, in the first embodiment, N1 = 1.544, N2 = 1.686, N3 = 1.744, N4 = 1.744, N5 = 1.669, therefore, the maximum value of the refractive index of all lenses in the optical lens group 1, Nmax, is N3 and N4.

[0145] In the optical lens group 1 of the first embodiment, the Abbe number of the first lens E1 is V1, the Abbe number of the second lens E2 is V2, the Abbe number of the third lens E3 is V3, the Abbe number of the fourth lens E4 is V4, and the Abbe number of the fifth lens E5 is V5. The minimum Abbe number among all lenses in the optical lens group 1 is Vdmin, which satisfies the following conditions: V5 = 19.5; and Vdmin = 18.4. In the first embodiment, V1 = 56.0, V2 = 18.4, V3 = 44.8, V4 = 44.8, and V5 = 19.5. Therefore, the minimum Abbe number among all lenses in the optical lens group is Vdmin = V2.

[0146] In the optical lens group 1 of the first embodiment, the thickness of the first lens E1 along the optical axis is CT1, the thickness of the second lens E2 along the optical axis is CT2, the thickness of the third lens E3 along the optical axis is CT3, the thickness of the fourth lens E4 along the optical axis is CT4, and the thickness of the fifth lens E5 along the optical axis is CT5. The minimum thickness of all lenses along the optical axis in the optical lens group 1 is CTmin, and the sum of the thicknesses of all lenses along the optical axis in the optical lens group 1 is ΣCT. The distance between the first lens E1 and the second lens E2 along the optical axis is T12, and the distance between the second lens E2 and the third lens E3 along the optical axis is T12. The distance between the third lens E3 and the fourth lens E4 on the optical axis is T23, the distance between the fourth lens E4 and the fifth lens E5 on the optical axis is T45, the maximum distance between all adjacent lenses in optical lens group 1 on the optical axis is ATmax, the distance on the optical axis from the reducing side surface of the fifth lens to the reducing side conjugate surface RCS is BL, and the distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the last lens is TD (in the first embodiment, that is, the distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the fifth lens), which satisfies the following condition: CT1 / CT3 = 0.41; CT2 / T12 = 1.31; CT2 / CT4 = 1.03; T12 / ATmax = 1.00; CT3 / CT5 = 5.80; CT3 / BL = 1.12; CT3 / CTmin = 5.80; T12 / (T23+T34+T45) = 1.93; and TD / ΣCT = 1.29; wherein, in the first embodiment, the spacing between adjacent lenses on the optical axis refers to the distance between two adjacent mirror surfaces of two adjacent lenses on the optical axis; ΣCT = CT1+CT2+CT3+CT4+CT5.

[0147] In the optical lens group 1 of the first embodiment, the radius of curvature of the magnifying side surface of the second lens is R3, and the radius of curvature of the reducing side surface of the second lens is R4, which satisfies the following condition: (R3+R4) / (R3-R4) = -2.66.

[0148] In the optical lens group 1 of the first embodiment, the focal length of the optical lens group 1 is f, the focal length of the first lens E1 is f1, the focal length of the second lens E2 is f2, and the focal length of the third lens E3 is f3, which satisfies the following condition: (|f / f1|+|f / f2|) / |f / f3| = 0.69.

[0149] In the optical lens group 1 of the first embodiment, the maximum distance between the optical effective area of ​​the magnifying side surface of the first lens and the optical axis is Y11, and the maximum distance between the optical effective area of ​​the reducing side surface of the fifth lens and the optical axis is Y52, which satisfies the following condition: Y11 / Y52 = 1.02.

[0150] In the optical lens group 1 of the first embodiment, the distance from the aperture ST to the conjugate surface RCS on the narrowing side on the optical axis is SL, and the distance from the magnifying side surface of the first lens to the conjugate surface RCS on the narrowing side on the optical axis is TL, which satisfies the following condition: SL / TL = 1.00.

[0151] In the optical lens group 1 of the first embodiment, the distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the last lens is TD (in the first embodiment, it refers to the distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the fifth lens), which satisfies the following condition: TD = 11.47 mm.

[0152] In the optical lens group 1 of the first embodiment, the effective diameter of the aperture of the optical lens group 1 is Ds, the maximum image height of the optical lens group 1 is ImgH, and the distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the last lens is TD (in the first embodiment, it refers to the distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the fifth lens), which satisfies the following conditions: Ds / ImgH = 1.67; Ds / TD = 0.42.

[0153] In the optical lens group 1 of the first embodiment, the maximum value of all principal ray angles of the optical lens group 1 is CRAmax, which satisfies the following condition: CRAmax = 20.12.

[0154] In the optical lens group 1 of the first embodiment, the perpendicular distance between the most inflection point closest to the optical axis on the magnifying or reducing surface of the third lens and the optical axis is Yc3 (in the first embodiment, it is the perpendicular distance between the most inflection point closest to the optical axis on the magnifying surface of the third lens and the optical axis), the perpendicular distance between the most inflection point closest to the optical axis on the magnifying or reducing surface of the fourth lens and the optical axis is Yc4 (in the first embodiment, it is the perpendicular distance between the most inflection point closest to the optical axis on the reducing surface of the fourth lens and the optical axis), and the perpendicular distance between the most inflection point closest to the optical axis on the magnifying or reducing surface of the last lens and the optical axis is Yc5 (in the first embodiment, it is the perpendicular distance between the most inflection point closest to the optical axis on the magnifying surface of the fifth lens and the optical axis). The focal length of the optical lens group is f, which satisfies the following conditions: Yc3 / f = 0.39; Yc4 / f = 0.23; and Yc5 / f = 0.29.

[0155] Please also refer to Table 1 and Table 2 below.

[0156]

[0157]

[0158] Table 1 is... Figure 1The first embodiment provides detailed structural data, where the units for radius of curvature, thickness, and focal length are mm, and surfaces 0-14 sequentially represent surfaces from the magnified side to the reduced side, with the refractive index measured at a reference wavelength. Table 2 shows the aspherical data in the first embodiment, where k represents the cone coefficient in the aspherical curve equation, and A4-A12 represent the 4th-12th order aspherical coefficients of each surface. Furthermore, the tables for the following embodiments are corresponding schematic diagrams and aberration curves for each embodiment. The definitions of the data in the tables are the same as those in Tables 1 and 2 of the first embodiment, and will not be repeated here.

[0159] Additionally, please refer to the table below. In the optical lens group 1 of the first embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0160]

[0161] <Second Embodiment>

[0162] Please refer to Figure 3 as well as Figure 4 ,in Figure 3 A schematic diagram of an optical lens group 2 according to a second embodiment of the present disclosure is shown. Figure 4 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the second embodiment. Figure 3 It is understood that the optical lens group 2 of the second embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction-side conjugate surface RCS. The optical lens group 2 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0163] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the first lens contains a point of inflection.

[0164] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the second lens contains a point of inflection.

[0165] The third lens E3 has positive refractive power and is made of glass. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the third lens contains a point of inflection.

[0166] The fourth lens, E4, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the fourth lens contain three inflection points and two inflection points, respectively.

[0167] The fifth lens, E5, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the fifth lens each contain two inflection points and one inflection point, respectively.

[0168] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 2.

[0169] Please also refer to Table 3 and Table 4 below.

[0170]

[0171]

[0172] In the second embodiment, the equation for the aspherical curve is expressed as in the first embodiment. Furthermore, the definitions of the parameters in the table below are the same as in the first embodiment, and will not be repeated here.

[0173] By referring to Tables 3 and 4, the following data can be calculated:

[0174]

[0175] It should be noted that in the second embodiment, Yc3 in the table above is the vertical distance between the inflection point closest to the optical axis on the magnifying side surface of the third lens and the optical axis, Yc4 is the vertical distance between the inflection point closest to the optical axis on the reducing side surface of the fourth lens and the optical axis, and Yc5 is the vertical distance between the inflection point closest to the optical axis on the reducing side surface of the fifth lens and the optical axis.

[0176] Additionally, please refer to the table below. In the optical lens group 2 of the second embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0177]

[0178] <Third Embodiment>

[0179] Please refer to Figure 5 as well as Figure 6 ,in Figure 5 A schematic diagram of an optical lens group 3 according to a third embodiment of the present disclosure is shown. Figure 6From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the third embodiment. Figure 5 As can be seen, the optical lens group 3 of the third embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction-side conjugate surface RCS. The optical lens group 3 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0180] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the first lens contains a point of inflection.

[0181] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the second lens each contain an inflection point.

[0182] The third lens E3 has positive refractive power and is made of glass. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the third lens contains a point of inflection.

[0183] The fourth lens, E4, has positive refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the fourth lens contain three inflection points and two inflection points, respectively.

[0184] The fifth lens, E5, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the fifth lens each contain two inflection points and one inflection point, respectively.

[0185] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 3.

[0186] Please also refer to Table 5 and Table 6 below.

[0187]

[0188]

[0189] In the third embodiment, the equation for the aspherical curve is expressed as in the first embodiment. Furthermore, the definitions of the parameters in the table below are the same as in the first embodiment, and will not be repeated here.

[0190] By referring to Tables 5 and 6, the following data can be calculated:

[0191]

[0192] It should be noted that in the third embodiment, Yc3 in the table above is the vertical distance between the inflection point closest to the optical axis on the magnifying side surface of the third lens and the optical axis, Yc4 is the vertical distance between the inflection point closest to the optical axis on the reducing side surface of the fourth lens and the optical axis, and Yc5 is the vertical distance between the inflection point closest to the optical axis on the reducing side surface of the fifth lens and the optical axis.

[0193] Additionally, please refer to the table below. In the optical lens group 3 of the third embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0194]

[0195] <Fourth Embodiment>

[0196] Please refer to Figure 7 as well as Figure 8 ,in Figure 7 A schematic diagram of an optical lens group 4 according to the fourth embodiment of this disclosure is shown. Figure 8 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the fourth embodiment. Figure 7 It is understood that the optical lens group 4 of the fourth embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction-side conjugate surface RCS. The optical lens group 4 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0197] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the first lens contains a point of inflection.

[0198] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the second lens contains a point of inflection.

[0199] The third lens E3 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is concave near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the third lens each contain an inflection point.

[0200] The fourth lens, E4, has negative refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is concave near the optical axis; both are aspherical. In addition, the magnifying side surface of the fourth lens contains a point of inflection.

[0201] The fifth lens, E5, has negative refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is concave near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the fifth lens each contain two inflection points and one inflection point, respectively.

[0202] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 4.

[0203] Please also refer to Table 7 and Table 8 below.

[0204]

[0205]

[0206] In the fourth embodiment, the equation for the aspherical curve is expressed as in the first embodiment. Furthermore, the definitions of the parameters in the table below are the same as in the first embodiment, and will not be repeated here.

[0207] By referring to Tables 7 and 8, the following data can be calculated:

[0208]

[0209] It should be noted that in the fourth embodiment, Yc3 in the table above is the vertical distance between the inflection point closest to the optical axis on the shrinking side surface of the third lens and the optical axis, Yc4 is the vertical distance between the inflection point closest to the optical axis on the magnifying side surface of the fourth lens and the optical axis, and Yc5 is the vertical distance between the inflection point closest to the optical axis on the shrinking side surface of the fifth lens and the optical axis.

[0210] Additionally, please refer to the table below. In the optical lens group 4 of the fourth embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0211]

[0212] <Fifth Embodiment>

[0213] Please refer to Figure 9 as well as Figure 10 ,in Figure 9 A schematic diagram of an optical lens group 5 according to the fifth embodiment of this disclosure is shown. Figure 10 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the fifth embodiment. Figure 9 It is understood that the optical lens group 5 of the fifth embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction-side conjugate surface RCS. The optical lens group 5 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0214] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the first lens contains a point of inflection.

[0215] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the second lens contains a point of inflection.

[0216] The third lens E3 has positive refractive power and is made of glass. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the reducing side surface of the third lens contains a point of inflection.

[0217] The fourth lens, E4, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, both the magnifying and reducing sides of the fourth lens contain an inflection point.

[0218] The fifth lens, E5, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, both the magnifying and reducing sides of the fifth lens contain an inflection point.

[0219] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 5.

[0220] Please also refer to Tables 9 and 10 below.

[0221]

[0222]

[0223] In the fifth embodiment, the equation for the aspherical curve is expressed as in the first embodiment. Furthermore, the definitions of the parameters in the table below are the same as in the first embodiment, and will not be repeated here.

[0224] By referring to Tables 9 and 10, the following data can be calculated:

[0225]

[0226] It should be noted that in the fifth embodiment, Yc3 in the table above is the vertical distance between the inflection point closest to the optical axis on the reduced side surface of the third lens and the optical axis, Yc4 is the vertical distance between the inflection point closest to the optical axis on the reduced side surface of the fourth lens and the optical axis, and Yc5 is the vertical distance between the inflection point closest to the optical axis on the reduced side surface of the fifth lens and the optical axis.

[0227] Additionally, please refer to the table below. In the optical lens group 5 of the fifth embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0228]

[0229] Please refer to the following: Figure 19 The diagram illustrates a configuration of the superlens E7 in the optical lens group 5 according to the fifth embodiment of this disclosure. Figure 19 It is understood that when the optical lens group 5 is applied to the projection lens group, it may also include an element having a super-interface; specifically, the optical lens group 5 also includes a super-interface lens E7, which is disposed between the fifth lens E5 and the filter element E6.

[0230] <Sixth Embodiment>

[0231] Please refer to Figure 11 as well as Figure 12 ,in Figure 11 A schematic diagram of an optical lens group 6 according to the sixth embodiment of this disclosure is shown. Figure 12 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the sixth embodiment. Figure 11 It is understood that the optical lens group 6 of the sixth embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction-side conjugate surface RCS. The optical lens group 6 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0232] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the first lens contains a point of inflection.

[0233] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is also concave near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the second lens each contain an inflection point.

[0234] The third lens E3 has positive refractive power and is made of glass. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the third lens contains a point of inflection.

[0235] The fourth lens, E4, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the fourth lens each contain one inflection point and two inflection points, respectively.

[0236] The fifth lens, E5, has negative refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is concave near the optical axis; both are aspherical. In addition, both the magnifying and reducing sides of the fifth lens contain an inflection point.

[0237] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 6.

[0238] Please also refer to Table 11 and Table 12 below.

[0239]

[0240]

[0241] In the sixth embodiment, the equation for the aspherical curve is expressed as in the first embodiment. Furthermore, the definitions of the parameters in the table below are the same as in the first embodiment, and will not be repeated here.

[0242] By referring to Tables 11 and 12, the following data can be calculated:

[0243]

[0244] It should be noted that in the sixth embodiment, Yc3 in the table above is the vertical distance between the inflection point closest to the optical axis on the magnifying side surface of the third lens and the optical axis, Yc4 is the vertical distance between the inflection point closest to the optical axis on the reducing side surface of the fourth lens and the optical axis, and Yc5 is the vertical distance between the inflection point closest to the optical axis on either the magnifying side surface or the reducing side surface of the fifth lens and the optical axis.

[0245] Additionally, please refer to the table below. In the optical lens group 6 of the sixth embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0246]

[0247] <Seventh Embodiment>

[0248] Please refer to Figure 13 as well as Figure 14 ,in Figure 13 A schematic diagram of an optical lens group 7 according to the seventh embodiment of this disclosure is shown. Figure 14 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the seventh embodiment. Figure 13 It is understood that the optical lens group 7 of the seventh embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction-side conjugate surface RCS. The optical lens group 7 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0249] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the first lens contains a point of inflection.

[0250] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is also concave near the optical axis; both are aspherical. In addition, the magnifying side surface and the reducing side surface of the second lens respectively contain one inflection point and two inflection points.

[0251] The third lens E3 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface and the reducing side surface of the third lens respectively contain two inflection points and one inflection point.

[0252] The fourth lens, E4, has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface and the reducing side surface of the fourth lens each contain two inflection points and one inflection point, respectively.

[0253] The fifth lens, E5, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is also concave near the optical axis; both are aspherical. In addition, the magnifying side surface and the reducing side surface of the fifth lens respectively contain two inflection points and one inflection point.

[0254] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 7.

[0255] Please also refer to Table 13 and Table 14 below.

[0256]

[0257]

[0258] In the seventh embodiment, the equation for the aspherical curve is expressed as in the first embodiment. Furthermore, the definitions of the parameters in the table below are the same as in the first embodiment, and will not be repeated here.

[0259] The following data can be derived by referring to Tables 13 and 14:

[0260]

[0261] It should be noted that in the seventh embodiment, Yc3 in the table above is the vertical distance between the inflection point closest to the optical axis on the magnification side surface of the third lens and the optical axis, Yc4 is the vertical distance between the inflection point closest to the optical axis on the magnification side surface of the fourth lens and the optical axis, and Yc5 is the vertical distance between the inflection point closest to the optical axis on the magnification side surface of the fifth lens and the optical axis.

[0262] Additionally, please refer to the table below. In the optical lens group 7 of the seventh embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0263]

[0264] <Eighth Embodiment>

[0265] Please refer to Figure 15 as well as Figure 16 ,in Figure 15 A schematic diagram of an optical lens group 8 according to the eighth embodiment of this disclosure is shown. Figure 16 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the eighth embodiment. Figure 15 It is understood that the optical lens group 8 of the eighth embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction-side conjugate surface RCS. The optical lens group 8 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0266] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is concave near the optical axis; both are aspherical. In addition, the magnifying side surface and the reducing side surface of the first lens each contain an inflection point.

[0267] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is also concave near the optical axis; both are aspherical. In addition, the reducing side surface of the second lens contains a point of inflection.

[0268] The third lens E3 has positive refractive power and is made of glass. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the third lens each contain an inflection point.

[0269] The fourth lens, E4, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the fourth lens each contain one inflection point and two inflection points, respectively.

[0270] The fifth lens, E5, has positive refractive power and is made of glass. Its magnifying side surface is convex near the optical axis, and its reducing side surface is concave near the optical axis; both are aspherical. In addition, both the magnifying and reducing sides of the fifth lens contain an inflection point.

[0271] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 8.

[0272] Please also refer to Table 15 and Table 16 below.

[0273]

[0274]

[0275] In the eighth embodiment, the equation for the aspherical curve is expressed as in the first embodiment. Furthermore, the definitions of the parameters in the table below are the same as in the first embodiment, and will not be repeated here.

[0276] By referring to Tables 15 and 16, the following data can be calculated:

[0277]

[0278] It should be noted that in the eighth embodiment, Yc3 in the table above is the vertical distance between the inflection point closest to the optical axis on the magnifying side surface of the third lens and the optical axis, Yc4 is the vertical distance between the inflection point closest to the optical axis on the reducing side surface of the fourth lens and the optical axis, and Yc5 is the vertical distance between the inflection point closest to the optical axis on the reducing side surface of the fifth lens and the optical axis.

[0279] Additionally, please refer to the table below. In the optical lens group 8 of the eighth embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0280]

[0281] <Ninth Embodiment>

[0282] Please refer to Figure 17 as well as Figure 18 ,in Figure 17 A schematic diagram of an optical lens group 9 according to the ninth embodiment of this disclosure is shown. Figure 18 From left to right, the graphs show the spherical aberration, astigmatism, and distortion curves of the ninth embodiment. Figure 17 It is understood that the optical lens group 9 of the ninth embodiment includes, from the magnification side to the reduction side, an aperture ST, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter element E6, and a reduction-side conjugate surface RCS. The optical lens group 9 includes five lenses (E1, E2, E3, E4, E5), and there are no other interposed lenses between the five lenses.

[0283] The first lens E1 has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface of the first lens contains a point of inflection.

[0284] The second lens E2 has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is convex near the optical axis; both are aspherical. In addition, the magnifying and reducing sides of the second lens each contain an inflection point.

[0285] The third lens E3 has negative refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is concave near the optical axis; both are aspherical. In addition, the magnifying side surface and the reducing side surface of the third lens respectively contain one inflection point and two inflection points.

[0286] The fourth lens, E4, has positive refractive power and is made of plastic. Its magnifying side surface is convex near the optical axis, and its reducing side surface is also convex near the optical axis; both are aspherical. In addition, the magnifying side surface and the reducing side surface of the fourth lens each contain two inflection points and one inflection point, respectively.

[0287] The fifth lens, E5, has negative refractive power and is made of plastic. Its magnifying side surface is concave near the optical axis, and its reducing side surface is also concave near the optical axis; both are aspherical. Additionally, the magnifying side surface of the fifth lens contains a point of inflection.

[0288] The filter element E6 is made of glass and is positioned between the fifth lens E5 and the reduced-side conjugate surface RCS without affecting the focal length of the optical lens group 9.

[0289] Please also refer to Tables 17 and 18 below.

[0290]

[0291]

[0292] In the ninth embodiment, the equation for the aspherical curve is expressed as in the first embodiment. Furthermore, the definitions of the parameters in the table below are the same as in the first embodiment, and will not be repeated here.

[0293] By referring to Tables 17 and 18, the following data can be calculated:

[0294]

[0295] It should be noted that in the ninth embodiment, Yc3 in the table above is the vertical distance between the inflection point closest to the optical axis on the shrinking side surface of the third lens and the optical axis, Yc4 is the vertical distance between the inflection point closest to the optical axis on the magnifying side surface of the fourth lens and the optical axis, and Yc5 is the vertical distance between the inflection point closest to the optical axis on the magnifying side surface of the fifth lens and the optical axis.

[0296] Additionally, please refer to the table below. In the optical lens group 9 of the ninth embodiment, the perpendicular distance Yc between the inflection point closest to the optical axis on each magnifying and reducing side surface of the first to fifth lenses and the optical axis and the focal length f of the optical lens group satisfies the following conditions.

[0297]

[0298] <Tenth Embodiment>

[0299] Figure 20A A perspective view of a head-mounted device 100 according to the tenth embodiment of this disclosure is shown. Figure 20B Drawing according to Figure 20A A system schematic diagram of the head-mounted device 100. Figure 20A and Figure 20B It is understood that the head-mounted device 100 includes an image display system 110 and may include a positioning strap 120 for the user 101 to position the image display system 110 in front of the eyes, so as to provide the user 101 with a stereoscopic image.

[0300] The image display system 110 can be divided into two sides, each side including a projection module 111 and an image transmission module 112. Each projection module 111 includes at least one projection lens group, which includes an optical lens group 1111 and an image source 1112. In the tenth embodiment, the optical lens group 1111 can be any of the optical lens groups in the first to ninth embodiments described above, the image source 1112 can be a DLP or LCD, and the image transmission module 112 can be a waveguide element, but the present disclosure is not limited thereto.

[0301] In this way, the head-mounted device 100 can provide the user with a comfortable visual experience and achieve a lightweight size.

[0302] <Eleventh Embodiment>

[0303] Figure 21 A system schematic diagram of a head-mounted device according to the eleventh embodiment of this disclosure is shown. Figure 21 As can be seen, the head-mounted device (not otherwise indicated) includes an image display system (not otherwise indicated) for the user 201 to view images. The image display system can be divided into two sides, each side including a projection module 211 and an image transmission module 212. Each projection module 211 includes at least one projection lens group, which includes an optical lens group and an image source. The projection module 211 in the eleventh embodiment may be the same as or similar to the projection module 111 in the tenth embodiment, but this disclosure is not limited thereto. It should be noted that in the eleventh embodiment, the image transmission module 212 includes multiple optical path deflection elements 2121, but this disclosure is not limited thereto.

[0304] <Twelfth Embodiment>

[0305] Figure 22A A system schematic diagram of a head-mounted device according to the twelfth embodiment of this disclosure is shown. Figure 22B It is a drawing according to Figure 22A A schematic diagram of the projection module 311 in the head-mounted device. Figure 22A and Figure 22B It is understood that the head-mounted device includes a light field image display system 310 for the user 301 to view images. The light field image display system 310 can be divided into two sides, each side including a projection module 311 and an image transmission module 312.

[0306] In detail, each projection module 311 includes at least three projection lens groups 311a, each of which includes an optical lens group 3111 and an image source 3112. Furthermore, the number of projection lens groups 311a included in the projection module 311 on one side of the light field image display system 310 can be between five and fifteen. This provides a better image display effect.

[0307] Each optical lens group 3111 may include at least three lenses, and at least one lens in the optical lens group 3111 may be made of plastic and have an aspherical surface. In the twelfth embodiment, the optical lens group 3111 may be any of the optical lens groups in the first to ninth embodiments described above, and the image source 3112 may be a DLP or LCD, but the present disclosure is not limited thereto.

[0308] Although the present disclosure has been described above with reference to embodiments, it is not intended to limit the present disclosure. Any person skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the scope defined in the appended claims.

Claims

1. An optical lens assembly, characterized in that, It contains five lenses, which are arranged in order from magnification to reduction: A first lens, a second lens, a third lens, a fourth lens, and a fifth lens; each of the lenses has a magnifying surface facing the magnifying direction and a reducing surface facing the reducing direction; The second lens has a concave surface near the optical axis on its magnifying side surface; at least one of the five lenses has at least one inflection point on at least one surface. The optical lens group also includes an aperture, the distance from the aperture to a conjugate surface on the narrowing side along the optical axis being SL; the radius of curvature of the magnifying side surface of the second lens being R3; the radius of curvature of the narrowing side surface of the second lens being R4; the distance from the magnifying side surface of the first lens to the conjugate surface on the narrowing side along the optical axis being TL; the thickness of the second lens on the optical axis being CT2; the thickness of the third lens on the optical axis being CT3; the thickness of the fourth lens on the optical axis being CT4; and the minimum thickness of all lenses in the optical lens group on the optical axis being CT4. CTmin, the distance on the optical axis from the shrinking side surface of the fifth lens to the conjugate surface of the shrinking side is BL, the effective diameter of the aperture of the optical lens group is Ds, the maximum image height of the optical lens group is ImgH, the optical axis spacing between the first lens and the second lens is T12, the optical axis spacing between the second lens and the third lens is T23, the optical axis spacing between the third lens and the fourth lens is T34, and the optical axis spacing between the fourth lens and the fifth lens is T45, which satisfy the following conditions: (R3+R4) / (R3-R4) < 0.50; 0.98 < SL / TL < 2.50; 0.65 < CT2 / CT4 < 4.50; 3.80 < CT3 / CTmin < 10.0; 0.55 < CT3 / BL; 0.70 < Ds / ImgH < 3.0; and 0.25 < T12 / (T23+T34+T45) < 4.

0.

2. The optical lens assembly as described in claim 1, characterized in that, The fourth lens has negative refractive power.

3. The optical lens assembly as described in claim 1, characterized in that, The fifth lens has negative refractive power.

4. The optical lens assembly as described in claim 1, characterized in that, The first lens has a convex surface near the optical axis on its magnifying side surface, and the first lens has a convex surface near the optical axis on its reducing side surface; the second lens has a convex surface near the optical axis on its reducing side surface; and the third lens has a convex surface near the optical axis on its reducing side surface.

5. The optical lens assembly as described in claim 1, characterized in that, The fifth lens has a concave surface near the optical axis on its narrowing side surface; at least one surface of the fifth lens contains at least one inflection point.

6. The optical lens assembly as described in claim 1, characterized in that, At least one surface of the third lens includes at least one inflection point, and the perpendicular distance between the inflection point closest to the optical axis on the magnifying or reducing surface of the third lens and the optical axis is Yc3. The focal length of the optical lens group is f, and it satisfies the following condition: 0.05 < Yc3 / f < 5.

0.

7. The optical lens assembly as described in claim 1, characterized in that, The minimum Abbe number among all lenses in this optical lens group is Vdmin, which satisfies the following condition: 5.0 < Vdmin < 21.

0.

8. The optical lens assembly as described in claim 1, characterized in that, The maximum refractive index of all lenses in this optical lens group is Nmax, and the aperture value of this optical lens group is Fno, which satisfies the following condition: 1.70 < Nmax < 1.80; and 0.80 < Fno < 2.

0.

9. The optical lens assembly as described in claim 1, characterized in that, The third lens contains the largest effective diameter of all the lenses.

10. The optical lens assembly as claimed in claim 1, characterized in that, The fifth lens is the final lens. The distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the final lens is TD. The sum of the thicknesses of all lenses in the optical lens group on the optical axis is ΣCT, which satisfies the following condition: 1.0 < TD / ΣCT < 1.

40.

11. The optical lens assembly as claimed in claim 1, characterized in that, The fifth lens is the final lens. The effective diameter of the aperture of the optical lens group is Ds. The distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the final lens is TD, which satisfies the following condition: 0.45 < Ds / TD < 1.

0.

12. The optical lens assembly as claimed in claim 1, characterized in that, The fifth lens is the final lens. The perpendicular distance between the most inflection point closest to the optical axis on the magnifying or reducing surface of the fourth lens and the optical axis is Yc4. The perpendicular distance between the most inflection point closest to the optical axis on the magnifying or reducing surface of the final lens and the optical axis is Yc5. The focal length of the optical lens group is f. The minimum Abbe number among all lenses in the optical lens group is Vdmin, which satisfies the following condition: 0.05 < Yc4 / f < 5.0; 0.05 < Yc5 / f < 5.0; and 5.0 < Vdmin < 20.

0.

13. The optical lens assembly as claimed in claim 1, characterized in that, In this optical lens group, at least three lenses have an Abbe number greater than 10.0 and less than 50.

0.

14. An optical lens assembly, characterized in that, It contains five lenses, which are arranged in order from magnification to reduction: A first lens, a second lens, a third lens, a fourth lens, and a fifth lens; each of the lenses has a magnifying surface facing the magnifying direction and a reducing surface facing the reducing direction; Wherein, the magnifying side surface of the second lens is concave near the optical axis; the magnifying side surface of the third lens is convex near the optical axis; and at least one magnifying side surface or reducing side surface of at least one lens in the optical lens group contains at least one inflection point. The optical lens group further includes an aperture, the distance from the aperture to a conjugate surface on the narrowing side along the optical axis being SL; the radius of curvature of the magnifying side surface of the second lens being R3; the radius of curvature of the narrowing side surface of the second lens being R4; the distance from the magnifying side surface of the first lens to the conjugate surface on the narrowing side along the optical axis being TL; the thickness of the first lens on the optical axis being CT1; the thickness of the second lens on the optical axis being CT2; the thickness of the third lens on the optical axis being CT3; the thickness of the fourth lens on the optical axis being CT4; and the thickness of the fifth lens on the optical axis being CT5. The thickness of the lens on the optical axis is CT5, the distance between the first lens and the second lens on the optical axis is T12, the maximum distance between all adjacent lenses in the optical lens group on the optical axis is ATmax, the maximum distance between the optically effective area of ​​the magnifying side surface of the first lens and the optical axis is Y11, the maximum distance between the optically effective area of ​​the reducing side surface of the fifth lens and the optical axis is Y52, the effective diameter of the aperture of the optical lens group is Ds, and the maximum image height of the optical lens group is ImgH. These conditions must be met: (R3+R4) / (R3-R4) < 0.25; 0.98 < SL / TL < 2.50; 0.40 < CT2 / CT4 < 4.50; 0 < CT1 / CT3 < 1.50; 3.0 < CT3 / CT5 < 7.0; 0.90 < CT2 / T12 < 5.0; 0.60 < T12 / ATmax ≤ 1.0; 0.65 < Y11 / Y52 < 1.50; and 1.0 < Ds / ImgH < 3.

0.

15. The optical lens assembly as described in claim 14, characterized in that, The first lens has positive refractive power; the second lens has negative refractive power; and the third lens has positive refractive power.

16. The optical lens assembly as claimed in claim 14, characterized in that, The fourth lens has a concave surface near the optical axis on its magnifying side.

17. The optical lens assembly as claimed in claim 14, characterized in that, The fourth lens has a convex surface near the optical axis on its narrowing side surface; at least one surface of the fourth lens contains at least one inflection point.

18. The optical lens assembly as claimed in claim 14, characterized in that, The Abbe number of the fifth lens is V5, which satisfies the following condition: 10.0 < V5 < 50.0。 19. The optical lens assembly as claimed in claim 14, characterized in that, The optical lens group has a focal length of f, the first lens has a focal length of f1, the second lens has a focal length of f2, and the third lens has a focal length of f3, satisfying the following conditions: 0.10 < (|f / f1|+|f / f2|) / |f / f3| < 1.

70.

20. The optical lens assembly as claimed in claim 14, characterized in that, The maximum value of all principal ray angles in this optical lens group is CRAmax, which satisfies the following condition: 0 ≤ CRAmax < 22.

0.

21. The optical lens assembly as claimed in claim 14, characterized in that, At least three lenses in this optical lens group are made of plastic; at least one lens in this optical lens group is made of glass.

22. The optical lens assembly as described in claim 14, characterized in that, The absolute value of the focal length of the third lens is the smallest of the absolute values ​​of the focal lengths of all lenses in the optical lens group.

23. The optical lens assembly as described in claim 14, characterized in that, The distance between the first lens and the second lens on the optical axis is the largest among all the optical axis distances between adjacent lenses.

24. A head-mounted device, characterized in that, Include: An image display system, which is divided into two sides, each side including a projection module and an image transmission module; Each of the projection modules includes at least one projection lens group, which includes the optical lens group as described in claim 14 and an image source.

25. A head-mounted device, characterized in that, Include: A light field image display system, which is divided into two sides, each side including a projection module and an image transmission module; The projection module includes at least three projection lens groups, each of which includes an optical lens group as described in claim 1 and an image source, wherein the fifth lens is a final lens. In each optical lens group, at least one lens is made of plastic and has an aspherical surface. Each of these optical lens groups also includes an aperture. The distance on the optical axis from the magnifying side surface of the first lens to the reducing side surface of the last lens is TD. The aperture value of the optical lens group is Fno, which satisfies the following condition: 1.0 mm < TD < 30.0 mm; and 0.80 < Fno < 2.

50.

26. The head-mounted device as claimed in claim 25, characterized in that, At least one magnifying or reducing side surface of at least one lens in each optical lens group includes at least one inflection point; the image transmission module includes a waveguide element.

27. The head-mounted device as claimed in claim 25, characterized in that, The at least three projection lens groups each include an element having an ultra-high-resolution interface.

28. The head-mounted device as claimed in claim 25, characterized in that, The number of projection lenses included in the projection module is between five and fifteen. Among all the lenses in each optical lens group, at least four lenses have an Abbe number greater than 10.0 and less than 50.0; Wherein, the distance on the optical axis from the aperture to the conjugate surface on the narrowing side is SL; the distance on the optical axis from the magnifying side surface of the first lens to the conjugate surface on the narrowing side is TL; the thickness on the optical axis of the first lens is CT1; the thickness on the optical axis of the second lens is CT2; the thickness on the optical axis of the third lens is CT3; the thickness on the optical axis of the fourth lens is CT4; the minimum thickness on the optical axis among all lenses in the optical lens group is CTmin; the effective diameter of the aperture of the optical lens group is Ds; the maximum image height of the optical lens group is ImgH; the first lens and the... The second lens is spaced T12 along the optical axis, the second lens and the third lens are spaced T23 along the optical axis, the third lens and the fourth lens are spaced T34 along the optical axis, the fourth lens and the fifth lens are spaced T45 along the optical axis, the aperture value of the optical lens group is Fno, the maximum distance between all adjacent lenses in the optical lens group along the optical axis is ATmax, the Abbe number of the fifth lens is V5, and the distance from the magnifying side surface of the first lens to the reducing side surface of the last lens along the optical axis is TD, which satisfies the following conditions: 1.0 ≤ SL / TL < 1.80; 0.85 < CT2 / CT4 < 2.50; 3.80 < CT3 / CTmin < 7.0; 1.0 < Ds / ImgH < 2.0; 0.45 < T12 / (T23+T34+T45) < 4.0; 0.80 < Fno < 1.85; 0.25 < CT1 / CT3 < 1.50; 1.0 < CT2 / T12 < 3.0; 0.80 < T12 / ATmax ≤ 1.0; Versions 10.0 < V5 < 25.0; and 3.0 mm < TD < 15.0 mm.

Images