AR projection lens and AR device

Abstract

The application provides an AR projection lens and an AR device. The AR projection lens comprises a first lens with negative optical power, a first side of the first lens being a convex surface and a second side being a concave surface; a second lens with positive optical power, a first side of the second lens being a convex surface and a second side being a convex surface; a third lens with negative optical power, a first side of the third lens being a concave surface and a second side being a concave surface; a fourth lens with positive optical power, a first side of the fourth lens being a concave surface and a second side being a convex surface; a prism; and a fifth lens with optical power. A distance T45 of the fourth lens and the fifth lens on an optical axis and an axial distance TD from the first side of the first lens to the second side of the fifth lens satisfy 0.6>T45 / TD>0.4. The application solves the problem of poor compactness of the AR projection lens in the prior art.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese patent application filed on August 30, 2024, with application number 202411217255.3, entitled "AR projection lens and AR device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of optical imaging equipment technology, and more specifically, to an AR projection lens and an AR device. Background Technology

[0004] With the continuous development of the field of optical imaging, various types of imaging devices have entered people's lives, especially augmented reality (AR) devices. Due to their unique display effects, they have gradually permeated people's entertainment, travel and other activities. Among them, AR glasses are the most popular AR devices. Their key component is the AR projection lens, which acts as an engine to project image information into people's eyes.

[0005] To match the lightweight and miniaturized AR devices, the AR projection lens, which occupies a large portion of the AR device, is particularly important in terms of miniaturization and compactness. Moreover, AR projection lenses are usually equipped with prisms to achieve light splitting. Since prisms are relatively large, compressing the size of the part containing the prism in the AR projection lens has a significant impact on the overall size.

[0006] In other words, existing AR projection lenses suffer from poor compactness. Summary of the Invention

[0007] The main objective of this invention is to provide an AR projection lens and an AR device to solve the problem of poor compactness in existing AR projection lenses.

[0008] To achieve the above objectives, according to one aspect of the present invention, an AR projection lens is provided, comprising: a first lens having negative optical power, wherein a first side surface of the first lens is convex and a second side surface is concave; a second lens having positive optical power, wherein both a first and second side surface are convex; a third lens having negative optical power, wherein both a first and second side surface are concave; a fourth lens having positive optical power, wherein a first side surface is concave and a second side surface is convex; a prism; and a fifth lens having optical power. The distance T45 between the fourth and fifth lenses on the optical axis satisfies the following relationship with the axial distance TD between the first side surface of the first lens and the second side surface of the fifth lens: 0.6 > T45 / TD > 0.4.

[0009] Further, a radius of curvature R9 of the first side surface of the fifth lens and a radius of curvature R10 of the second side surface of the fifth lens satisfy: 0.31≤R9 / R10≤1.01.

[0010] Further, an effective focal length f2 of the second lens and an effective focal length f of the AR projection lens satisfy: 0.3<f2 / f<0.7.

[0011] Further, a color dispersion coefficient V3 of the third lens, a color dispersion coefficient V4 of the fourth lens, an effective focal length f3 of the third lens and an effective focal length f4 of the fourth lens satisfy: -1.2<V3 / V4*f3 / f4<-0.2.

[0012] Further, a color dispersion coefficient V1 of the first lens, a color dispersion coefficient V2 of the second lens, a radius of curvature R2 of the second side surface of the first lens and a radius of curvature R3 of the first side surface of the second lens satisfy: 0.4<V1 / V2*R2 / R3≤1.18.

[0013] Further, a refractive index N1 of the first lens, a refractive index N2 of the second lens, a refractive index N3 of the third lens, a refractive index N4 of the fourth lens and a refractive index N5 of the fifth lens satisfy: 1.4<(N1+N2+N3) / (N4+N5)<1.9.

[0014] Further, an effective focal length f of the AR projection lens and an entrance pupil diameter epd of the AR projection lens satisfy: 1.8<f / epd<2.6.

[0015] Further, an entrance pupil diameter epd of the AR projection lens and a half of the maximum length of the chip diagonal of the image surface Imgh satisfy: 1.4<epd / Imgh<1.6.

[0016] Further, an effective focal length f3 of the third lens, a radius of curvature R5 of the first side surface of the third lens and a radius of curvature R6 of the second side surface of the third lens satisfy: -0.46≤f3 / (R5+R6)<1, and f3 / (R5+R6) is not equal to 0.

[0017] Further, an effective focal length f5 of the fifth lens and a central thickness CT5 of the fifth lens on the optical axis satisfy: -82.38≤f5 / CT5≤223.99, and f5 / CT5 is not equal to 0.

[0018] Further, an on-axis distance SAG12 between the intersection of the second side surface of the first lens and the optical axis and the effective radius vertex of the second side surface of the first lens and a central thickness CT1 of the first lens on the optical axis satisfy: 0.4<SAG12 / CT1<2.

[0019] Further, the refractive index of at least two lenses among the first lens, the second lens, the third lens, the fourth lens and the fifth lens is greater than 1.8 and less than 2.5.

[0020] Further, the AR projection lens further comprises a phase plate between the fifth lens and the image plane chip.

[0021] Further, the AR projection lens further comprises a diaphragm on the first side of the first lens.

[0022] According to another aspect of the present application, an AR device is provided, which comprises the above-mentioned AR projection lens.

[0023] By using the technical scheme of the present application, the AR projection lens comprises a first lens with negative optical power, the first side of the first lens is convex, and the second side is concave; a second lens with positive optical power, the first side of the second lens is convex, and the second side is convex; a third lens with negative optical power, the first side of the third lens is concave, and the second side is concave; a fourth lens with positive optical power, the first side of the fourth lens is concave, and the second side is convex; a prism; and a fifth lens with optical power. The distance T45 of the fourth lens and the fifth lens on the optical axis and the axial distance TD from the first side of the first lens to the second side of the fifth lens satisfy the condition: 0.6>T45 / TD>0.4.

[0024] The AR projection lens of the present application adjusts the positions of the light rays passing through the lenses by reasonably arranging the positional relationship of the lenses, constraining the optical power and surface shape of the lenses, and constraining the condition between the distance T45 of the fourth lens and the fifth lens on the optical axis and the axial distance TD from the first side of the first lens to the second side of the fifth lens, i.e. 0.6>T45 / TD>0.4, which is beneficial to adjusting the positions of the light rays passing through the lenses, ensuring smooth transition of the light rays, improving aberration, ensuring the optical performance of the AR projection lens, ensuring the projection effect, and at the same time, being beneficial to matching the demand for small size, compressing the gap between the lenses, and ensuring the compactness of the AR projection lens. In addition, the tolerance of the image plane chip to the assembly position can be effectively improved, the insensitivity of the image plane chip to the defocus position change is reduced, and the production yield and production efficiency are further improved. The length and volume of the prism part in the AR projection lens occupy a reasonable level in the whole AR projection lens, and the total system length and volume are small while avoiding the problems of light utilization rate, machining and assembly caused by too small prism, and avoiding the case of too large prism which increases the overall volume of the AR projection lens, which is beneficial to improving the structural compactness of the AR projection lens. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the application and, together with the description, serve to explain the application. In the drawings:

[0026] Figure 1 A structural schematic diagram of an AR projection lens of embodiment one of the present application is shown;

[0027] Figures 2 to 4 Axial chromatic aberration curves, astigmatism curves and distortion curves of the AR projection lens in Figure 1 are shown respectively;

[0028] Figure 5 A structural schematic diagram of an AR projection lens of embodiment two of the present application is shown;

[0029] Figures 6 to 8 Axial chromatic aberration curves, astigmatism curves and distortion curves of the AR projection lens in Figure 5 are shown respectively;

[0030] Figure 9 A structural schematic diagram of an AR projection lens of embodiment three of the present application is shown;

[0031] Figures 10 to 12 Axial chromatic aberration curves, astigmatism curves and distortion curves of the AR projection lens in Figure 9 are shown respectively;

[0032] Figure 13 A structural schematic diagram of an AR projection lens of embodiment four of the present application is shown;

[0033] Figures 14 to 16 Axial chromatic aberration curves, astigmatism curves and distortion curves of the AR projection lens in Figure 13 are shown respectively;

[0034] Figure 17 A structural schematic diagram of an AR projection lens of embodiment five of the present application is shown;

[0035] Figures 18 to 20 Axial chromatic aberration curves, astigmatism curves and distortion curves of the AR projection lens in Figure 17 are shown respectively.

[0036] Wherein, the above drawings include the following reference signs:

[0037] STO, stop; E1, first lens; S1, first side of the first lens; S2, second side of the first lens; E2, second lens; S3, first side of the second lens; S4, second side of the second lens; E3, third lens; S5, first side of the third lens; S6, second side of the third lens; E4, fourth lens; S7, first side of the fourth lens; S8, second side of the fourth lens; E5, fifth lens; S11, first side of the fifth lens; S12, second side of the fifth lens; E6, prism; S9, first side of the prism; S10, second side of the prism; E7, phase plate; S13, first side of the phase plate; S14, second side of the phase plate; E8, protective glass; S15, first side of the protective glass; S16, second side of the protective glass; S17, image plane chip. DETAILED DESCRIPTION

[0038] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict, unless otherwise specified. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0039] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meanings as commonly understood by those skilled in the art to which the present application belongs.

[0040] In the present application, unless otherwise specified, the orientation words such as "upper", "lower", "top", "bottom" are generally directed to the directions shown in the drawings, or are directed to the vertical, perpendicular or gravity directions of the components themselves; similarly, for the convenience of understanding and description, "inner" and "outer" refer to the inner and outer relative to the contour of the components themselves, but the above orientation words are not used to limit the present application.

[0041] It should be noted that, in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0042] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for the convenience of illustration. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0043] In the present disclosure, the near-axis region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the near-axis region. If the lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the near-axis region. The surface of each lens near the first side is referred to as the first side surface of the lens, and the surface of each lens near the second side is referred to as the second side surface of the lens. The judgment of the surface shape in the near-axis region can be based on the judgment method of a person skilled in the art. For the first side surface, when the R value (R refers to the radius of curvature in the near-axis region, usually refers to the R value in the lens data of the optical software) is positive, it is determined to be convex, and when the R value is negative, it is determined to be concave. For the second side surface, when the R value is positive, it is determined to be concave, and when the R value is negative, it is determined to be convex.

[0044] It should be noted that the left side of the AR projection lens is the first side, and the right side is the second side. The first side of the AR projection lens is the imaging side, and the second side is the image source side. The image emitted by the image source chip is imaged on the imaging plane on the imaging side.

[0045] In order to solve the problem of poor compactness of the AR projection lens in the prior art, the present application provides an AR projection lens and an AR device.

[0046] As shown in Figures 1 to 20 In an optional embodiment of the present application, the AR projection lens includes a first lens with negative optical power, the first side surface of the first lens is convex, and the second side surface is concave; a second lens with positive optical power, the first side surface of the second lens is convex, and the second side surface is convex; a third lens with negative optical power, the first side surface of the third lens is concave, and the second side surface is concave; a fourth lens with positive optical power, the first side surface of the fourth lens is concave, and the second side surface is convex; a prism; and a fifth lens with optical power. The distance T45 of the fourth lens and the fifth lens on the optical axis and the axial distance TD of the first side surface of the first lens to the second side surface of the fifth lens satisfy: 0.6>T45 / TD>0.4.

[0047] The AR projection lens of the present application is beneficial to adjusting the position of light rays through each lens, ensuring smooth transition of light rays, improving aberration, ensuring the optical performance of the AR projection lens, ensuring the projection effect, while being beneficial to matching the demand for small size, compressing the gap between each lens, and ensuring the compactness of the AR projection lens. In addition, it can effectively improve the tolerance of the image plane chip to the assembly position, reduce the insensitivity of the image plane chip to the defocus position change, and further improve the production yield and production efficiency. The length and volume of the prism part in the AR projection lens occupy a reasonable level in the entire AR projection lens, and the total system length and volume are small while avoiding the problems of light utilization, machining and assembly caused by the small prism, while avoiding the case of too large prism to increase the overall volume of the AR projection lens, which is beneficial to improving the structural compactness of the AR projection lens.

[0048] It should be noted that the focal length of the first lens is less than zero, the focal length of the second lens is greater than zero, the focal length of the third lens is less than zero, the focal length of the fourth lens is greater than zero, and the focal length of the fifth lens can be greater than zero or less than zero. By reasonably controlling the focal length of each lens, it is beneficial to control the imaging distance by controlling the light path, and to ensure smooth transition of light rays.

[0049] It should also be noted that the above prism is actually a polarization beam splitter prism to realize the beam splitting effect of light rays.

[0050] In the present embodiment, the radius of curvature R9 of the first side of the fifth lens and the radius of curvature R10 of the second side of the fifth lens satisfy: 0.31≤R9 / R10≤1.01. Satisfying this condition is beneficial to optimizing the light path of light rays through the fifth lens, correcting aberration, and improving imaging quality.

[0051] In the present embodiment, the effective focal length f2 of the second lens and the effective focal length f of the AR projection lens satisfy: 0.3<f2 / f<0.7. Satisfying this condition is beneficial to reasonably distributing the refractive power of the second lens, so that the refractive power of the second lens is not too large, while avoiding the sensitivity problem caused by the too concentrated refractive power of the lens, which is beneficial to the subsequent assembly of the AR projection lens.

[0052] In the embodiment, the third lens satisfies the condition: -1.2 < V3 / V4*f3 / f4 < -0.2. Satisfying the condition formula is conducive to correcting and balancing the chromatic aberration of the entire AR projection lens, and improving the clarity and color accuracy of imaging. The dispersion coefficient is the Abbe number.

[0053] In the embodiment, the first lens satisfies the condition: 0.4 < V1 / V2*R2 / R3 < 1.18. Satisfying the condition formula can balance the chromatic aberration of the system, reduce the imaging blur caused by dispersion, and ensure clear imaging.

[0054] In the embodiment, the first lens satisfies the condition: 1.4 < (N1+N2+N3) / (N4+N5) < 1.9. Satisfying the condition formula is conducive to avoiding the case that the refractive index of the last two lenses in the AR projection lens, i.e., the fourth lens and the fifth lens, is too high at the same time, avoiding high dispersion and serious chromatic aberration, and being conducive to mutual correction of the chromatic aberration of the entire system, improving the clarity and color accuracy of imaging.

[0055] In the embodiment, the effective focal length f of the AR projection lens and the entrance pupil diameter epd of the AR projection lens satisfy the condition: 1.8 < f / epd < 2.6. Such a setting makes the aperture number of the AR projection lens greater than 1.8, which is conducive to ensuring that the imaging quality is at a relatively good level, while limiting the light flux, so that the illumination intensity of the optical system is within an acceptable range.

[0056] In the embodiment, the entrance pupil diameter epd of the AR projection lens and half of the maximum length Imgh of the chip diagonal of the image plane satisfy the condition: 1.4 < epd / Imgh < 1.6. Satisfying the condition formula is conducive to making the entrance pupil diameter of the AR projection lens relatively large, and improving the light energy utilization rate of the entire optical system.

[0057] In the embodiment, the effective focal length f3 of the third lens, the curvature radius R5 of the first side of the third lens, and the curvature radius R6 of the second side of the third lens satisfy the condition: -0.46 < < f3 / (R5+R6) < 1, and f3 / (R5+R6) is not equal to 0. By limiting the relationship between the optical power and the curvature radius of the third lens, it is conducive to ensuring the process machinability of the third lens, reducing the manufacturing cost, and improving the durability and reliability of the third lens.

[0058] In the embodiment, the effective focal length f5 of the fifth lens and the central thickness CT5 of the fifth lens on the optical axis satisfy: -82.38≤f5 / CT5≤223.99, and f5 / CT5 is not equal to 0. By limiting the relationship between the effective focal length and the central thickness of the fifth lens, the positive focal power of the rear part of the AR projection lens is not concentrated on one lens, the assembly sensitivity is reduced, and the degree of lens bending is easier to manufacture in the process.

[0059] In the embodiment, the on-axis distance SAG12 between the intersection of the second side surface of the first lens and the optical axis and the effective radius vertex of the second side surface of the first lens and the central thickness CT1 of the first lens on the optical axis satisfy: 0.4<SAG12 / CT1<2. Satisfying the condition formula is conducive to limiting the degree of meniscus shape of the first lens, conducive to the processing and manufacturing of the first lens, and also conducive to the more compact structure of the head part of the AR projection lens.

[0060] In the embodiment, the refractive index of at least two lenses among the first lens, the second lens, the third lens, the fourth lens and the fifth lens is greater than 1.8 and less than 2.5. Satisfying the condition formula is conducive to shortening the total length of the optical system, thereby reducing the volume, and the use of two lenses is also conducive to correcting the system chromatic aberration of different colors in the optical system and improving the imaging quality.

[0061] In the embodiment, the AR projection lens further comprises a phase plate, and the phase plate is located between the fifth lens and the image plane chip. The phase plate is a flat plate, and the phase plate is placed between the fifth lens and the image plane chip. The arrangement enables the phase plate to change the phase of the light, which helps to reduce aberration, increase image clarity, reduce the structural complexity of the AR projection lens, and improve system flexibility. In actual assembly, the phase plate and the image plane chip can be glued together to facilitate high-precision assembly of the phase plate and ensure imaging performance.

[0062] In the embodiment, the AR projection lens further comprises a diaphragm, and the diaphragm is located on the first side of the first lens. Placing the diaphragm on the imaging side of the AR projection lens is conducive to controlling the imaging size and ensuring the brightness and clarity of the image.

[0063] According to another aspect of the present application, an AR device is provided, which comprises the AR projection lens described above. The AR device equipped with the AR projection lens described above can be miniaturized and has compact structure.

[0064] The specific surface shape and parameters of the AR projection lens applicable to the above embodiments are further described below with reference to the accompanying drawings.

[0065] It should be noted that any one of the following embodiments one to five is applicable to all embodiments of the present application.

[0066] Embodiment one

[0067] As shown in Figures 1 to 4 , an AR projection lens of embodiment one is described. Figure 1 A structural schematic diagram of the AR projection lens of embodiment one is shown.

[0068] As shown in Figure 1 , the AR projection lens comprises, in order from the first side to the second side: a diaphragm STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a prism E6, a fifth lens E5, a phase plate E7, a protective glass E8, and an image plane chip S17.

[0069] In the present embodiment, the first lens E1 has a negative optical power, the first side surface S1 of the first lens is a convex surface, and the second side surface S2 of the first lens is a concave surface; the second lens E2 has a positive optical power, the first side surface S3 of the second lens is a convex surface, and the second side surface S4 of the second lens is a convex surface; the third lens E3 has a negative optical power, the first side surface S5 of the third lens is a concave surface, and the second side surface S6 of the third lens is a concave surface; the fourth lens E4 has a positive optical power, the first side surface S7 of the fourth lens is a concave surface, and the second side surface S8 of the fourth lens is a convex surface; the fifth lens E5 has a negative optical power, the first side surface S11 of the fifth lens is a concave surface, and the second side surface S12 of the fifth lens is a convex surface. The prism E6 has a first side surface S9 and a second side surface S10 of the prism, and both the first side surface S9 and the second side surface S10 of the prism are flat surfaces. The phase plate E7 has a first side surface S13 and a second side surface S14 of the phase plate. The protective glass E8 has a first side surface S15 and a second side surface S16 of the protective glass.

[0070] Table 1 below shows the basic structural parameter table of the AR projection lens of embodiment one, wherein the units of the curvature radius and the thickness are millimeters (mm).

[0071] Table 1

[0072]

[0073] In embodiment one, the fourth lens E4 is an aspherical lens, and the surface type of the aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0074]

[0075] Wherein, Z is the distance vector height of the aspheric surface along the optical axis direction at a height of r, r represents the Y-axis coordinate value of each point on the lens surface; c is the reciprocal of the curvature radius r of the lens surface; k is the conic coefficient, A2m is the coefficient of the additional polynomial, that is, the coefficient of the high-order term of the aspheric surface, m = 2, 3, 4, …, and M is the highest term number of the additional polynomial. Table 2 below gives the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 of the aspheric surface that can be used in Embodiment One.

[0076] Table 2

[0077] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S7 1.1121E-03 -1.9553E-03 1.4406E-03 -6.1488E-04 1.6063E-04 -1.8099E-05 -1.6131E-06 5.6674E-07 -3.5773E-08 S8 1.4296E-03 -6.5608E-04 1.1831E-04 1.1774E-05 -2.4982E-06 -3.9748E-07 5.3869E-08 -1.2841E-08 1.6792E-09

[0078] In this embodiment, the first side S13 of the phase plate is a diffractive surface, and Table 3 below shows the parameters of the diffractive surface. In this embodiment, the diffraction order of the diffractive surface is 1. The phase distribution of the diffractive surface satisfies the following formula:

[0079]

[0080] Wherein, N is the number of polynomial coefficients in the series, Ai is the coefficient of the i-th polynomial expansion, M is the diffraction order, and p is the phase term.

[0081] Table 3

[0082] Face number P2 P4 P6 P8 P10 S13 -2.9672E-02 3.7269E-04 2.0124E-04 -1.5512E-04 2.3453E-05 Face number P12 P14 P16 P18 P20 S13 -9.5497E-07 2.5907E-08 8.5485E-10 -2.2627E-10 -3.3315E-11

[0083] Figure 2 The axial chromatic aberration curve of the AR projection lens of Embodiment One is shown in the figure. As can be seen from the figure, the chromatic aberration curve of Embodiment One is relatively narrow, the chromatic aberration is relatively small, and the imaging quality is relatively good. Figure 3 The astigmatism curve of the AR projection lens of Embodiment One is shown in the figure. As can be seen from the figure, the astigmatism curve of Embodiment One has a relatively low height value, and the imaging clarity is relatively good. Figure 4 The distortion curve of the AR projection lens of Embodiment One is shown in the figure. As can be seen from the figure, the angle and coverage range of the distortion curve of Embodiment One are relatively low, and the distortion is relatively small.

[0084] According to Figures 2 to 4 It can be seen that the AR projection lens given in Embodiment One can achieve good imaging quality.

[0085] Embodiment Two

[0086] As Figures 5 to 8 shown, the AR projection lens of Embodiment Two is described. Figure 5 The structural schematic diagram of the AR projection lens of Embodiment Two is shown in the figure.

[0087] As Figure 5As shown, the AR projection lens sequentially comprises, from the first side to the second side: a diaphragm STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a prism E6, a fifth lens E5, a phase plate E7, a protective glass E8, an image plane chip S17.

[0088] In the embodiment, the first lens E1 has a negative focal power, the first side S1 of the first lens is a convex surface, and the second side S2 of the first lens is a concave surface; the second lens E2 has a positive focal power, the first side S3 of the second lens is a convex surface, and the second side S4 of the second lens is a convex surface; the third lens E3 has a negative focal power, the first side S5 of the third lens is a concave surface, and the second side S6 of the third lens is a concave surface; the fourth lens E4 has a positive focal power, the first side S7 of the fourth lens is a concave surface, and the second side S8 of the fourth lens is a convex surface; the fifth lens E5 has a negative focal power, the first side S11 of the fifth lens is a concave surface, and the second side S12 of the fifth lens is a convex surface. The prism E6 has a first side S9 and a second side S10 of the prism, and the first side S9 and the second side S10 of the prism are both flat surfaces. The phase plate E7 has a first side S13 and a second side S14 of the phase plate. The protective glass E8 has a first side S15 and a second side S16 of the protective glass.

[0089] Table 4 below shows the basic structural parameter table of the AR projection lens of Example Two, wherein the units of the curvature radius and the thickness are millimeters (mm).

[0090] Table 4

[0091]

[0092] In Example Two, the fourth lens E4 is an aspherical lens. Table 5 below shows the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of the aspherical surface that can be used in Example Two.

[0093] Table 5

[0094] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S7 -2.4465E-03 -1.6082E-03 1.2237E-03 -6.2293E-04 1.6496E-04 -1.7324E-05 -1.6088E-06 5.4810E-07 -3.6700E-08 S8 -1.1249E-03 -3.5366E-04 2.4341E-05 8.6987E-07 -1.9879E-06 -1.0685E-07 9.7502E-08 -1.1888E-08 3.0682E-10

[0095] In the embodiment, the first side S13 of the phase plate is a diffraction surface, and Table 6 below shows the parameters of the diffraction surface. In the embodiment, the diffraction order of the diffraction surface is 1.

[0096] Table 6

[0097] Face number P^2 P^4 P^6 P^8 P^10 S13 -3.9148E-03 -9.4606E-04 5.7126E-04 -1.7896E-04 2.3199E-05 Face number P^12 P^14 P^16 P^18 P^20 S13 -1.1256E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0098] Figure 6The on-axis chromatic aberration curve of the AR projection lens of embodiment two is shown. As can be seen from the figure, the chromatic aberration curve of embodiment two is relatively small in width, the chromatic aberration is relatively small, and the imaging quality is relatively good. Figure 7 The astigmatism curve of the AR projection lens of embodiment two is shown. As can be seen from the figure, the astigmatism curve of embodiment two has a relatively low height value, and the imaging clarity is relatively good. Figure 8 The distortion curve of the AR projection lens of embodiment two is shown. As can be seen from the figure, the angle and coverage range of the distortion curve of embodiment two are relatively low, and the distortion is relatively small.

[0099] According to the above analysis, it can be seen that the AR projection lens given by embodiment two can achieve good imaging quality. Figures 6 to 8

[0100] Embodiment three

[0101] As shown in the figure, the AR projection lens of embodiment three is described. Figures 9 to 12 The structure schematic diagram of the AR projection lens of embodiment three is shown. Figure 9 As shown in the figure, the AR projection lens sequentially includes, from the first side to the second side: a diaphragm STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a prism E6, a fifth lens E5, a phase plate E7, a protective glass E8, and an image plane chip S17.

[0102] Figure 9 In this embodiment, the first lens E1 has a negative focal power, the first side S1 of the first lens is a convex surface, and the second side S2 of the first lens is a concave surface; the second lens E2 has a positive focal power, the first side S3 of the second lens is a convex surface, and the second side S4 of the second lens is a convex surface; the third lens E3 has a negative focal power, the first side S5 of the third lens is a concave surface, and the second side S6 of the third lens is a concave surface; the fourth lens E4 has a positive focal power, the first side S7 of the fourth lens is a concave surface, and the second side S8 of the fourth lens is a convex surface; the fifth lens E5 has a positive focal power, the first side S11 of the fifth lens is a convex surface, and the second side S12 of the fifth lens is a concave surface. The prism E6 has a first side S9 and a second side S10 of the prism, and both the first side S9 and the second side S10 of the prism are flat surfaces. The phase plate E7 has a first side S13 and a second side S14 of the phase plate. The protective glass E8 has a first side S15 and a second side S16 of the protective glass.

[0103] The following table 7 shows the basic structure parameter table of the AR projection lens of embodiment three, wherein the units of the curvature radius and the thickness are millimeters (mm).

[0104] Table 7

[0105] Table 7

[0106] ​​

[0107]

[0108] In embodiment three, the fourth lens E4 is an aspherical lens. Table 8 below gives the high order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of the aspherical surface that can be used in embodiment three.

[0109] Table 8

[0110] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S7 -2.1572E-05 -1.4105E-03 1.1851E-03 -6.1610E-04 1.6655E-04 -1.7317E-05 -1.6741E-06 5.3806E-07 -3.4294E-08 S8 -1.3142E-03 -7.1155E-05 -3.0516E-04 2.4869E-04 -1.0693E-04 2.6279E-05 -3.7532E-06 2.8879E-07 -9.2968E-09

[0111] In this embodiment, the first side S13 of the phase plate is a diffractive surface, and the parameters of the diffractive surface are shown in Table 9 below. In this embodiment, the diffraction order of the diffractive surface is 1.

[0112] Table 9

[0113] Face number P^2 P^4 P^6 P^8 P^10 S13 -2.0426E-02 8.7097E-05 2.9502E-04 -1.4296E-04 2.3694E-05 Face number P^12 P^14 P^16 P^18 P^20 S13 -1.2227E-06 -1.6057E-08 -1.8284E-09 -1.0497E-10 4.9362E-11

[0114] Figure 10 The on-axis chromatic aberration curve of the AR projection lens of embodiment three is shown, and from the figure it can be seen that the chromatic aberration curve of embodiment three is relatively small in width, the chromatic aberration is relatively small, and the imaging quality is relatively good. Figure 11 The astigmatism curve of the AR projection lens of embodiment three is shown, and from the figure it can be seen that the astigmatism curve of embodiment three has a relatively low height value, and the imaging clarity is relatively good. Figure 12 The distortion curve of the AR projection lens of embodiment three is shown, and from the figure it can be seen that the angle and coverage range of the distortion curve of embodiment three are relatively low, and the distortion is relatively small.

[0115] According to Figures 10 to 12 It can be seen that the AR projection lens given in embodiment three can achieve good imaging quality.

[0116] Embodiment four

[0117] As Figures 13 to 16 shown, the AR projection lens of embodiment four is described. Figure 13 The structural schematic diagram of the AR projection lens of embodiment four is shown.

[0118] As Figure 13 shown, the AR projection lens sequentially includes, from the first side to the second side: a stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a prism E6, a fifth lens E5, a phase plate E7, a protective glass E8, and an image surface chip S17.

[0119] In the embodiment, the first lens E1 has negative refractive power, the first side S1 of the first lens is convex, and the second side S2 of the first lens is concave; the second lens E2 has positive refractive power, the first side S3 of the second lens is convex, and the second side S4 of the second lens is convex; the third lens E3 has negative refractive power, the first side S5 of the third lens is concave, and the second side S6 of the third lens is concave; the fourth lens E4 has positive refractive power, the first side S7 of the fourth lens is concave, and the second side S8 of the fourth lens is convex; the fifth lens E5 has positive refractive power, the first side S11 of the fifth lens is convex, and the second side S12 of the fifth lens is concave. The prism E6 has a first side S9 and a second side S10 of the prism, and the first side S9 and the second side S10 of the prism are both flat. The phase plate E7 has a first side S13 and a second side S14 of the phase plate. The protective glass E8 has a first side S15 and a second side S16 of the protective glass.

[0120] Table 10 below shows the basic structure parameter table of the AR projection lens of Example Four, wherein the units of the curvature radius and the thickness are millimeters (mm).

[0121] Table 10

[0122]

[0123] In Example Four, the fifth lens E5 is an aspherical lens. Table 11 below shows the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of the aspherical surface that can be used in Example Four.

[0124] Table 11

[0125] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S11 7.3487E-03 -6.3419E-03 4.3391E-03 -1.7871E-03 4.4023E-04 -6.8255E-05 6.5063E-06 -3.4880E-07 8.0346E-09 S12 7.4772E-03 -9.9981E-03 7.3471E-03 -3.1482E-03 8.1096E-04 -1.3141E-04 1.3052E-05 -7.2432E-07 1.7188E-08

[0126] In the embodiment, the first side S13 of the phase plate is a diffraction surface, and Table 12 below shows the parameters of the diffraction surface. In the embodiment, the diffraction order of the diffraction surface is 1.

[0127] Table 12

[0128] Face number P^2 P^4 P^6 P^8 P^10 S13 -2.9672E-02 3.7269E-04 2.0124E-04 -1.5512E-04 2.3453E-05 Face number P^12 P^14 P^16 P^18 P^20 S13 -9.5497E-07 2.5907E-08 8.5485E-10 -2.2627E-10 -3.3315E-11

[0129] Figure 14 The on-axis chromatic aberration curve of the AR projection lens of Example Four is shown, and from the figure it can be seen that the chromatic aberration curve width of Example Four is smaller, the chromatic aberration is smaller, and the imaging quality is better. Figure 15 The astigmatism curve of the AR projection lens of Example Four is shown, and from the figure it can be seen that the astigmatism curve height value of Example Four is lower, and the imaging clarity is better. Figure 16The distortion curve of the AR projection lens of embodiment four is shown. As can be seen from the figure, the angle and coverage range of the distortion curve of embodiment four are low, and the distortion is small.

[0130] According to Figures 14 to 16 It can be seen that the AR projection lens given in embodiment four can achieve good imaging quality.

[0131] Embodiment five

[0132] As Figures 17 to 20 shown, the AR projection lens of embodiment five is described. Figure 17 The structural schematic diagram of the AR projection lens of embodiment five is shown.

[0133] As Figure 17 shown, the AR projection lens comprises, in order from the first side to the second side: a diaphragm STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a prism E6, a fifth lens E5, a phase plate E7, a protective glass E8, and an image plane chip S17.

[0134] In this embodiment, the first lens E1 has a negative focal power, the first side S1 of the first lens is a convex surface, and the second side S2 of the first lens is a concave surface; the second lens E2 has a positive focal power, the first side S3 of the second lens is a convex surface, and the second side S4 of the second lens is a convex surface; the third lens E3 has a negative focal power, the first side S5 of the third lens is a concave surface, and the second side S6 of the third lens is a concave surface; the fourth lens E4 has a positive focal power, the first side S7 of the fourth lens is a concave surface, and the second side S8 of the fourth lens is a convex surface; the fifth lens E5 has a negative focal power, the first side S11 of the fifth lens is a concave surface, and the second side S12 of the fifth lens is a convex surface. The prism E6 has a first side S9 and a second side S10 of the prism, and both the first side S9 and the second side S10 of the prism are flat surfaces. The phase plate E7 has a first side S13 and a second side S14 of the phase plate. The protective glass E8 has a first side S15 and a second side S16 of the protective glass.

[0135] The following Table 13 shows the basic structural parameter table of the AR projection lens of embodiment five, wherein the units of the curvature radius and the thickness are millimeters (mm).

[0136] Table 13

[0137]

[0138] In embodiment five, the fourth lens E4 is an aspherical lens. The following Table 14 gives the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of the aspherical surface that can be used in embodiment five.

[0139] Table 14

[0140] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S7 -4.8720E-05 -1.1257E-07 1.7671E-07 5.9145E-08 1.2747E-08 2.3716E-09 4.1275E-10 0.0000E+00 0.0000E+00 S8 1.6463E-03 -6.5429E-04 1.1864E-04 1.1795E-05 -2.4994E-06 -3.9810E-07 5.3733E-08 0.0000E+00 0.0000E+00

[0141] In the embodiment, the first side S13 of the phase plate and the second side S14 of the phase plate are diffractive surfaces, and the following Table 15 shows the parameters of the diffractive surfaces. In the embodiment, the diffraction order of the diffractive surfaces is 1.

[0142] Table 15

[0143] Face number P^2 P^4 P^6 P^8 P^10 S13 1.7470E+06 3.4990E+10 -6.3230E+13 1.2260E+16 2.9700E+19 S14 3.3596E+02 -4.7386E+02 4.5437E+01 5.4210E+00 -3.5700E-01 Face number P^12 P^14 P^16 P^18 P^20 S13 2.1030E+22 -1.9440E+24 -3.7970E+27 -2.5470E+32 2.5210E+35 S14 -9.8000E-02 -4.7150E-03 1.4790E-03 3.1110E-04 -3.8160E-05

[0144] Figure 18 The on-axis chromatic aberration curve of the AR projection lens of embodiment five is shown, and it can be known from the figure that the chromatic aberration curve width of embodiment five is smaller, the chromatic aberration is smaller, and the imaging quality is better. Figure 19 The astigmatism curve of the AR projection lens of embodiment five is shown, and it can be known from the figure that the astigmatism curve height value of embodiment five is lower, and the imaging clarity is better. Figure 20 The distortion curve of the AR projection lens of embodiment five is shown, and it can be known from the figure that the angle and coverage range of the distortion curve of embodiment five are lower, and the distortion is smaller.

[0145] According to Figures 18 to 20 It can be known that the AR projection lens given by embodiment five can realize good imaging quality.

[0146] In summary, embodiments one to five respectively satisfy the relationships shown in Table 16.

[0147] Table 16

[0148] Conditional expression / Example One Two Three Four Five R9 / R10 0.63 0.31 0.96 1.01 0.64 T45 / TD 0.46 0.49 0.53 0.53 0.45 f2 / f 0.43 0.37 0.53 0.63 0.41 V3 / V4*f3 / f4 -0.61 -0.28 -0.38 -1.17 -0.61 V1 / V2*R2 / R3 1.18 0.50 0.55 0.43 1.18 (N1+N2+N3) / (N4+N5) 1.61 1.80 1.45 1.54 1.61 f / epd 2.49 2.49 1.94 1.85 2.57 epd / Imgh 1.54 1.54 1.54 1.54 1.49 f3 / (R5+R6) -0.17 0.40 0.68 -0.46 -0.17 f5 / CT5 -11.62 -82.38 46.25 223.99 -12.78 SAG12 / CT1 0.43 1.91 1.73 1.30 0.42

[0149] Table 17 gives the effective focal length f of the AR projection lens of embodiments one to five, and the effective focal length f1 to f5 of each lens (unit: mm).

[0150] Table 17

[0151] Example / base data Imgh Fno f f1 f2 f3 f4 f5 One 2.60 2.49 9.94 -15.76 4.24 -4.02 5.06 -19.65 Two 2.60 2.49 9.95 -16.15 3.67 -3.88 7.10 -32.95 Three 2.60 1.94 7.75 -17.97 4.08 -3.85 6.61 35.49 Four 2.60 1.85 7.40 -10.28 4.62 -5.20 5.55 98.78 Five 2.69 2.57 10.28 -15.82 4.24 -4.02 5.04 -18.88

[0152] Obviously, the above-described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0153] It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0154] It should be noted that the terms "first", "second", and the like, herein do not necessarily have an ordinal meaning. Rather, such terms are used to distinguish a like feature from another feature in the specification. It should be understood that like reference numerals are used throughout the disclosure to indicate like elements, features or steps unless otherwise noted.

[0155] The preferred embodiments of the application are described above in detail. The application, however, is not limited to the precise embodiments described, and obviously many modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the application. It is intended that all such modifications and changes be included in the scope of the application as long as they fall within the scope of the appended claims.

Claims

1. An AR projection lens, characterized by, In order from the first side to the second side, the AR projection lens comprises: a first lens with negative optical power, a first side of the first lens being convex, and a second side of the first lens being concave; a second lens with positive optical power, a first side of the second lens being convex, and a second side of the second lens being convex; a third lens with negative optical power, a first side of the third lens being concave, and a second side of the third lens being concave; a fourth lens with positive optical power, a first side of the fourth lens being concave, and a second side of the fourth lens being convex; a prism; a fifth lens with optical power, the fifth lens having negative optical power, a first side of the fifth lens being concave, and a second side of the fifth lens being convex, or the fifth lens having positive optical power, a first side of the fifth lens being convex, and a second side of the fifth lens being concave; a total number of lenses with optical power in the AR projection lens is five; the AR projection lens further comprises an image plane chip, the image plane chip being located at the second side of the fifth lens, and light emitted by the image plane chip exits from the first side of the AR projection lens after sequentially passing through the fifth lens, the prism, the fourth lens, the third lens, the second lens, and the first lens; wherein a distance T45 of the fourth lens and the fifth lens on the optical axis and an axial distance TD from the first side of the first lens to the second side of the fifth lens satisfy: 0.6>T45 / TD>0.4; a color dispersion coefficient V3 of the third lens, a color dispersion coefficient V4 of the fourth lens, an effective focal length f3 of the third lens, and an effective focal length f4 of the fourth lens satisfy: -1.2<V3 / V4*f3 / f4<-0.

2.

2. The AR projection lens of claim 1, wherein, a curvature radius R9 of the first side of the fifth lens and a curvature radius R10 of the second side of the fifth lens satisfy: 0.31≤R9 / R10≤1.

01.

3. The AR projection lens of claim 1, wherein, an effective focal length f2 of the second lens and an effective focal length f of the AR projection lens satisfy: 0.3<f2 / f<0.

7.

4. The AR projection lens of claim 1, wherein, a color dispersion coefficient V1 of the first lens, a color dispersion coefficient V2 of the second lens, a curvature radius R2 of the second side of the first lens, and a curvature radius R3 of the first side of the second lens satisfy: 0.4<V1 / V2*R2 / R3≤1.

18.

5. The AR projection lens of claim 1, wherein, a refractive index N1 of the first lens, a refractive index N2 of the second lens, a refractive index N3 of the third lens, a refractive index N4 of the fourth lens, and a refractive index N5 of the fifth lens satisfy: 1.4<(N1+N2+N3) / (N4+N5)<1.

9.

6. The AR projection lens of claim 1, wherein, an effective focal length f of the AR projection lens and an entrance pupil diameter epd of the AR projection lens satisfy: 1.8<f / epd<2.

6.

7. The AR projection lens of claim 1, wherein, an entrance pupil diameter epd of the AR projection lens and a half of a maximum length Imgh of a diagonal line of the image plane chip satisfy: 1.4<epd / Imgh<1.

6.

8. The AR projection lens of claim 1, wherein, An effective focal length f3 of the third lens, a radius of curvature R5 of a first side of the third lens, and a radius of curvature R6 of a second side of the third lens satisfy: -0.46≤f3 / (R5+R6)<1, and f3 / (R5+R6) is not equal to 0.

9. The AR projection lens of claim 1, wherein, An effective focal length f5 of the fifth lens and a central thickness CT5 of the fifth lens on the optical axis satisfy: -82.38≤f5 / CT5≤223.99, and f5 / CT5 is not equal to 0.

10. The AR projection lens of claim 1, wherein, An on-axis distance SAG12 between an intersection of a second side of the first lens and the optical axis and an effective radius vertex of the second side of the first lens and a central thickness CT1 of the first lens on the optical axis satisfy: 0.4<SAG12 / CT1<2.

11. The AR projection lens of claim 1, wherein, Refractive indexes of at least two lenses of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are greater than 1.8 and less than 2.

5.

12. The AR projection lens of claim 1, wherein, The AR projection lens further includes a phase plate between the fifth lens and the image plane chip.

13. The AR projection lens of claim 1, wherein, The AR projection lens further includes a diaphragm on a first side of the first lens.

14. An AR device, comprising: An AR projection lens includes any one of claims 1-13. An AR projection lens includes any one of claims 1-13.

Images