WO2019210736A1 - Projection lens - Google Patents

Abstract

Provided is a projection lens. The projection lens comprises, from an imaging side to an image source side along an optical axis: a first lens (E1), a second lens (E2) and a third lens (E3). The first lens (E1) has a positive focal power; the second lens (E2) has a negative focal power, and a near imaging side surface thereof is a concave surface while a near image source side thereof is a convex surface; and the third lens (E3) has a positive focal power, and a near imaging side surface thereof is a convex surface. The total effective focal length f of the projection lens and the center thickness CT2 of the second lens (E2) on the optical axis satisfy 3.0 ≤ f/CT2 < 5.5.

Description

Projection lens

Cross-reference to related applications

The present application claims priority to and the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the present disclosure.

Technical field

The present application relates to a projection lens, and more particularly, to a projection lens including three lenses.

Background technique

In recent years, with the continuous advancement of imaging technology, the application range of projection lenses has become wider and wider, and interactive projection devices have gradually emerged. In order to meet the requirements of miniaturized electronic devices and interactive, the projection lens needs to have a large field of view and good imaging quality while ensuring miniaturization to ensure image information acquisition.

However, the conventional projection lens usually eliminates various aberrations by increasing the number of lenses, and improves the resolution, which causes an increase in the total length of the projection lens, which is disadvantageous for miniaturization of the lens. On the other hand, a larger field of view causes the distortion of the projection lens to be difficult to control, and the image quality is poor, which is not conducive to the projection of accurate image information.

Summary of the invention

The present application provides a projection lens that is applicable to miniaturized electronic devices that at least solves or partially addresses at least one of the above disadvantages of the prior art.

The present application provides a projection lens that includes, in order from the imaging side to the image source side along the optical axis, a first lens, a second lens, and a third lens. Wherein, the first lens may have a positive power; the second lens may have a negative power, the near imaging side may be a concave surface, the near image source side may be a convex surface; the third lens may have a positive power, and the near imaging side thereof Can be convex.

In one embodiment, the total effective focal length f of the projection lens and the center thickness CT2 of the second lens on the optical axis may satisfy 3.0 ≤ f / CT2 < 5.5.

In one embodiment, the center thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens at the maximum effective radius may satisfy 0.5<CT2/ET2≤1.6.

In one embodiment, the center thickness CT2 of the second lens on the optical axis and the separation distance T12 of the first lens and the second lens on the optical axis may satisfy 0.3<CT2/T12<1.0.

In one embodiment, the effective focal length f1 of the first lens and the total effective focal length f of the projection lens may satisfy 1.0<f1/f<1.3.

In one embodiment, the total effective focal length f of the projection lens and the effective focal length f2 of the second lens may satisfy -3.0 < f / f2 < 0.

In one embodiment, the effective focal length f2 of the second lens and the effective focal length f3 of the third lens may satisfy -2.5 < f2 / f3 < -0.5.

In one embodiment, the radius of curvature R4 of the near image source side of the second lens and the radius of curvature R3 of the near imaging side of the second lens may satisfy 1.5 < R4 / R3 < 5.0.

In one embodiment, the total effective focal length f of the projection lens and the radius of curvature R2 of the near image source side of the first lens may satisfy -1.9 <f/R2<-1.3.

In one embodiment, the intersection of the near image source side and the optical axis of the second lens to the effective radius apex of the second lens near image source side is the distance SAG22 on the optical axis and the intersection of the near imaging side and the optical axis of the second lens to The distance SAG21 of the effective radius apex of the near-imaging side of the second lens on the optical axis satisfies 0.8<SAG22/SAG21<1.3.

In one embodiment, the refractive index N1 of the first lens and the refractive index N2 of the second lens may satisfy (N1+N2)/2≤1.63.

In one embodiment, the entrance pupil diameter EPD of the projection lens and the diagonal IH of the image source region of the projection lens may satisfy 0.2<EPD/IH<0.7.

In one embodiment, the total effective focal length f of the projection lens and the half IH of the diagonal of the image source region of the projection lens may satisfy 0.8 < f / IH ≤ 1.3.

In one embodiment, the maximum effective radius DT11 of the near-imaging side of the first lens and the maximum effective radius DT31 of the near-imaging side of the third lens may satisfy 0.2<DT11/DT31<0.5.

In one embodiment, the near image source side of the third lens may be convex; the total effective focal length f of the projection lens and the curvature radius R6 of the near image source side of the third lens may satisfy -1.0<f/R6<0.

In one embodiment, the near image source side of the third lens may be a concave surface; the effective focal length f2 of the second lens and the effective focal length f3 of the third lens may satisfy −2.5<f2/f3≤−1.1; the second lens is near The radius of curvature R4 of the image side and the radius of curvature R3 of the near image side of the second lens may satisfy 1.6<R4/R3<2.5; and the center thickness CT2 of the second lens on the optical axis is with the first lens and the second lens The separation distance T12 on the optical axis can satisfy 0.3<CT2/T12≤0.6.

The present invention adopts three lenses, and the projection lens has a large field of view by rationally selecting the lens material and rationally distributing the power, the surface shape, the center thickness of each lens, and the on-axis spacing between the lenses. Angle, miniaturization, and at least one beneficial effect that can be applied to the infrared band.

DRAWINGS

Other features, objects, and advantages of the present invention will become more apparent from the description of the appended claims. In the drawing:

1 is a schematic structural view of a projection lens according to Embodiment 1 of the present application;

2A to 2B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 1;

3 is a schematic structural view of a projection lens according to Embodiment 2 of the present application;

4A to 4B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 2;

FIG. 5 is a schematic structural diagram of a projection lens according to Embodiment 3 of the present application;

6A to 6B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 3;

FIG. 7 is a schematic structural diagram of a projection lens according to Embodiment 4 of the present application;

8A to 8B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 4;

FIG. 9 is a schematic structural diagram of a projection lens according to Embodiment 5 of the present application;

10A to 10B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 5;

FIG. 11 is a schematic structural view of a projection lens according to Embodiment 6 of the present application;

12A to 12B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 6;

FIG. 13 is a schematic structural diagram of a projection lens according to Embodiment 7 of the present application;

14A to 14B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 7;

15 is a schematic structural view of a projection lens according to Embodiment 8 of the present application;

16A to 16B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 8;

17 is a schematic structural view of a projection lens according to Embodiment 9 of the present application;

18A to 18B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 9;

19 is a schematic structural view of a projection lens according to Embodiment 10 of the present application;

20A to 20B respectively show a distortion curve and a contrast curve of the projection lens of Embodiment 10;

21 is a schematic structural view of a projection lens according to Embodiment 11 of the present application;

22A to 22B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 11;

23 is a schematic structural view of a projection lens according to Embodiment 12 of the present application;

24A to 24B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 12;

25 is a schematic structural view of a projection lens according to Embodiment 13 of the present application;

26A to 26B are respectively a distortion curve and a contrast curve of the projection lens of Embodiment 13.

detailed description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is only illustrative of the exemplary embodiments of the present application, and is not intended to limit the scope of the application. Throughout the specification, the same drawing reference numerals refer to the same elements. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in the present specification, the expressions of the first, second, etc. are used to distinguish one feature from another, and do not represent any limitation of the feature. Thus, the first lens discussed below may also be referred to as a second lens, and the second lens may also be referred to as a first lens, without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of the lens have been somewhat exaggerated for convenience of explanation. Specifically, the spherical or aspherical shape shown in the drawings is shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the spherical or aspherical shape shown in the drawings. The drawings are only examples and are not to scale.

As used herein, a paraxial region refers to a region near the optical axis. If the surface of the lens is convex and the position of the convex surface is not defined, it indicates that the surface of the lens is convex at least in the paraxial region; if the surface of the lens is concave and the position of the concave surface is not defined, it indicates that the surface of the lens is at least in the paraxial region. Concave. The surface of each lens near the image source side is referred to as the near image source side, and the surface of each lens near the imaging side is referred to as the near imaging side.

It is also to be understood that the terms "comprising", "including", "having", "include","," However, it is not excluded that one or more other features, elements, components, and/or combinations thereof are present. Moreover, when an expression such as "at least one of" appears after the list of listed features, the entire listed features are modified instead of the individual elements in the list. Further, when describing an embodiment of the present application, "may" is used to mean "one or more embodiments of the present application." Also, the term "exemplary" is intended to mean an example or an illustration.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having meaning consistent with their meaning in the context of the related art, and will not be interpreted in an idealized or overly formal sense unless This is clearly defined in this article.

It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings.

The features, principles, and other aspects of the present application are described in detail below.

The projection lens according to an exemplary embodiment of the present application may include, for example, three lenses having powers, that is, a first lens, a second lens, and a third lens. The three lenses are sequentially arranged along the optical axis from the imaging side to the image source side.

In an exemplary embodiment, the first lens may have a positive power; the second lens may have a negative power, the near imaging side may be a concave surface, the near image source side may be a convex surface; and the third lens may have a positive power The near imaging side may be convex.

In an exemplary embodiment, the near image source side of the first lens may be convex.

Properly configuring the power and shape of each lens can effectively shorten the total length of the lens and meet the needs of miniaturization.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 3.0≤f/CT2<5.5, where f is the total effective focal length of the projection lens and CT2 is the center thickness of the second lens on the optical axis. More specifically, f and CT2 can further satisfy 3.08 ≤ f / CT2 ≤ 5.33. Satisfying the conditional formula 3.0 ≤ f / CT2 < 5.5, is conducive to shortening the total length of the lens.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression (N1+N2)/2≤1.63, where N1 is the refractive index of the first lens and N2 is the refractive index of the second lens. More specifically, N1 and N2 may further satisfy 1.53 ≤ (N1 + N2)/2 ≤ 1.63. The use of a material with a lower refractive index allows the system to have a better dispersion effect and can effectively save costs.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression -3.0 < f / f2 < 0, where f is the total effective focal length of the projection lens and f2 is the effective focal length of the second lens. More specifically, f and f2 can further satisfy -2.44 ≤ f / f2 ≤ -0.30. Reasonably assigning the total effective focal length of the projection lens and the effective focal length of the second lens can effectively control the deflection of the light, reduce the sensitivity of the lens, and at the same time help to reduce the spherical aberration, astigmatism, etc. of the optical system, and is advantageous for improving the projection lens. Imaging quality.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 0.8<SAG22/SAG21<1.3, wherein the SAG22 is effective for the intersection of the near image source side and the optical axis of the second lens to the second lens near image source side. The on-axis distance of the radius apex, SAG21 is the on-axis distance from the intersection of the near-imaging side of the second lens and the optical axis to the apex of the effective radius of the near-imaging side of the second lens. More specifically, SAG22 and SAG21 can further satisfy 0.87 ≤ SAG22 / SAG21 ≤ 1.24. The thickness of the second lens is reasonably configured to make the edge-to-center brightness uniform, thereby effectively improving the contrast, thereby improving the imaging quality of the projection lens.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 1.0<f1/f<1.3, where f1 is the effective focal length of the first lens and f is the total effective focal length of the projection lens. More specifically, f1 and f can further satisfy 1.07 ≤ f1/f ≤ 1.18. The conditional expression 1.0<f1/f<1.3 is satisfied, so that the total effective focal length of the projection lens and the effective focal length of the first lens are more rationally distributed, thereby facilitating correction of the spherical aberration of the projection lens and improving the imaging quality of the projection lens.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression -2.5 < f2 / f3 < -0.5, where f2 is the effective focal length of the second lens and f3 is the effective focal length of the third lens. More specifically, f2 and f3 can further satisfy -2.14 ≤ f2 / f3 ≤ -0.73. The conditional expression -2.5 < f2 / f3 < -0.5 is satisfied, so that the distribution of the power of the second lens and the third lens is more reasonable, thereby facilitating correction of the field curvature of the projection lens and improving the imaging quality of the projection lens.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 1.5<R4/R3<5.0, where R4 is the radius of curvature of the near image source side of the second lens, and R3 is the near imaging side of the second lens. Radius of curvature. More specifically, R4 and R3 may further satisfy 1.67 ≤ R4 / R3 ≤ 4.86. The conditional expression 1.5<R4/R3<5.0 is satisfied, so that the curve of the second lens is smoother and the shape is more uniform, so that the total length of the projection lens can be effectively reduced, and the angle of view of the projection lens can be increased.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 0.8<f/IH≤1.3, where f is the total effective focal length of the projection lens, and IH is half the diagonal length of the image source region. More specifically, f and IH can further satisfy 0.87 ≤ f / IH ≤ 1.29. Reasonably configuring the total effective focal length and image height of the projection lens can effectively reduce the distortion and improve the processing technology of the lens, and at the same time, it can improve the edge brightness of each lens and improve the image quality of the projection lens.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 0.2<EPD/IH<0.7, wherein the EPD is the entrance pupil diameter of the projection lens, and IH is half the diagonal length of the image source region. More specifically, EPD and IH can further satisfy 0.35 ≤ EPD / IH ≤ 0.64. Reasonable configuration of the entrance lens diameter and image height of the projection lens can effectively control the size of the projection lens, reduce the volume of the projection lens, and realize the miniaturization of the projection lens.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 0.5<CT2/ET2≤1.6, where CT2 is the center thickness of the second lens on the optical axis, and ET2 is the second lens at the maximum effective radius. Edge thickness. More specifically, CT2 and ET2 can further satisfy 0.73 ≤ CT2 / ET2 ≤ 1.51. By controlling the center of the second lens and the thickness of the edge, the incident angle of the light on the near image source side of the second lens can be effectively controlled, and the imaging quality of the projection lens is improved.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression -1.9 < f / R2 < - 1.3, where f is the total effective focal length of the projection lens, and R2 is the radius of curvature of the near image source side of the first lens . More specifically, f and R2 may further satisfy -1.75 ≤ f / R2 ≤ -1.36. By controlling the total effective focal length of the projection lens and the radius of curvature of the near-source side of the first lens, the off-axis aberration of the optical system can be corrected, thereby effectively improving the imaging quality of the projection lens.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 0.2<DT11/DT31<0.5, wherein DT11 is the maximum effective radius of the near imaging side of the first lens, and DT31 is the near imaging side of the third lens. The maximum effective radius. More specifically, DT11 and DT31 can further satisfy 0.26 ≤ DT11 / DT31 ≤ 0.39. By optimally configuring the maximum effective radius of the near-imaging side of the first lens and the near-imaging side of the third lens, the structural size of the projection lens can be effectively controlled, which is beneficial to the assembly process of the lens; at the same time, the projection lens can be effectively improved. Imaging quality.

In an exemplary embodiment, the projection lens of the present application may satisfy the conditional expression 0.3<CT2/T12<1.0, where CT2 is the center thickness of the second lens on the optical axis, and T12 is the first lens and the second lens in the light. The separation distance on the axis. More specifically, CT2 and T12 can further satisfy 0.36 ≤ CT2 / T12 ≤ 0.96. When the conditional formula 0.3<CT2/T12<1.0 is satisfied, the total length of the lens system can be effectively shortened, the volume of the lens can be reduced, and the lens can be miniaturized.

In an exemplary embodiment, the near image source side of the third lens may be convex. Further, the radius of curvature R6 of the near image source side of the third lens and the total effective focal length f of the projection lens may satisfy -1.0<f/R6<0. More specifically, f and R6 may further satisfy -0.75 ≤ f / R6 < 0. The near-source side of the third lens is convex, which helps to keep the light uniform, no vignetting, and can better correct the distortion.

In an exemplary embodiment, the near image source side of the third lens may be a concave surface. In the case where the near image source side of the third lens is arranged in a concave surface, the lens parameters are further adjusted such that the lens satisfies: -2.5 < f2 / f3 ≤ -1.1, where f2 is the effective focal length of the second lens, and f3 is Effective focal length of the third lens; 1.6 < R4 / R3 < 2.5, where R4 is the radius of curvature of the near image source side of the second lens, R3 is the radius of curvature of the near imaging side of the second lens; and 0.3 < CT2 / T12 ≤ 0.6, where CT2 is the center thickness of the second lens on the optical axis, and T12 is the separation distance of the first lens and the second lens on the optical axis. More specifically, f2 and f3 may further satisfy -2.14 ≤ f2 / f3 ≤ - 1.14; R4 and R3 may further satisfy 1.67 ≤ R4 / R3 ≤ 2.31; and CT2 and T12 may further satisfy 0.37 ≤ CT2 / T12 ≤ 0.59. Such a configuration is advantageous for correcting the field curvature of the projection lens, improving the imaging quality of the projection lens, and effectively shortening the total length of the projection lens and increasing the field of view of the projection lens.

In an exemplary embodiment, the above projection lens may further include at least one aperture to enhance the imaging quality of the lens. Alternatively, an aperture may be disposed between the imaging side and the first lens.

The projection lens according to the above embodiment of the present application may employ, for example, three lenses, by reasonably selecting the material of the lens and rationally distributing the power, the surface shape, the center thickness of each lens, and the on-axis spacing between the lenses. Etc., so that the projection lens has sufficient field of view, miniaturization and the like. The projection lens configured as described above can be used as an interactive projection lens applied to the infrared band.

In the embodiment of the present application, an aspherical mirror surface is often used for each lens. The aspherical lens is characterized by a continuous change in curvature from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, the aspherical lens has better curvature radius characteristics, and has the advantages of improving distortion and improving astigmatic aberration. With an aspherical lens, the aberrations that occur during imaging can be eliminated as much as possible, improving image quality.

However, those skilled in the art will appreciate that the various results and advantages described in this specification can be obtained without varying the number of lenses that make up the projection lens without departing from the technical solutions claimed herein. For example, although three lenses have been described as an example in the embodiment, the projection lens is not limited to including three lenses. The projection lens can also include other numbers of lenses if desired.

A specific embodiment of a projection lens applicable to the above embodiment will be further described below with reference to the drawings.

Example 1

A projection lens according to Embodiment 1 of the present application will be described below with reference to FIGS. 1 to 2B. FIG. 1 is a block diagram showing the structure of a projection lens according to Embodiment 1 of the present application.

As shown in FIG. 1, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 along an optical axis from an imaging side to an image source side.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a concave surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 1 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 1, in which the unit of curvature radius and thickness are both millimeters (mm).

Table 1

As can be seen from Table 1, the near-imaging side and the near-source side of any one of the first lens E1 to the third lens E3 are aspherical. In this embodiment, the face shape x of each aspherical lens can be defined by using, but not limited to, the following aspherical formula:

Where x is the distance of the aspherical surface at height h from the optical axis, and the distance from the aspherical vertex is high; c is the abaxial curvature of the aspherical surface, c=1/R (ie, the paraxial curvature c is the above table) 1 is the reciprocal of the radius of curvature R; k is the conic coefficient (given in Table 1); Ai is the correction coefficient of the a-th order of the aspherical surface. The higher order coefficient A ₄ , A ₆ , A ₈ , A ₁₀ , A ₁₂ , A ₁₄ , A ₁₆ and A _{18 which} can be used for each aspherical mirror surface S1-S6 in the embodiment 1 are given in Table 2 below.

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-1.0029E+00	7.5884E+00	-5.1243E+02	1.6780E+04	-3.2312E+05	3.5420E+06	-2.0327E+07	4.7272E+07
S2	-4.5135E-02	4.1888E-01	-6.1162E+00	2.9685E+01	-4.5099E+01	1.3997E+01	7.1587E+01
S3	-6.6035E-01	4.3582E-01	-1.5408E-01	2.1912E+01	-2.4886E+01	-7.0720E+01	1.0768E+02
S4	-1.8261E-01	-1.4631E-01	1.1810E+01	-6.4205E+01	1.5793E+02	-1.8472E+02	8.3896E+01
S5	-4.9582E-02	3.5081E-01	-5.0811E-01	8.4710E-01	-1.5566E+00	1.4201E+00	-4.9113E-01
S6	1.2371E-01	-1.1124E+00	5.5058E+00	-1.1090E+01	1.0953E+01	-5.4017E+00	1.0649E+00

Table 2

Table 3 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 1, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.26	-1.31	1.01	1.11	44.3

table 3

2A shows a distortion curve of the projection lens of Embodiment 1, which shows the amount of distortion corresponding to the height of different image sources. Fig. 2B shows a phase contrast curve of the projection lens of Embodiment 1, which shows the degree of contrast corresponding to the height of different image sources. 2A and 2B, the projection lens given in Embodiment 1 can achieve good image quality.

Example 2

A projection lens according to Embodiment 2 of the present application will be described below with reference to FIGS. 3 to 4B. In the present embodiment and the following embodiments, a description similar to Embodiment 1 will be omitted for the sake of brevity. FIG. 3 is a schematic structural view of a projection lens according to Embodiment 2 of the present application.

As shown in FIG. 3, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a concave surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 4 shows the surface type, the radius of curvature, the thickness, the material, and the conical coefficient of each lens of the projection lens of Example 2, wherein the unit of the radius of curvature and the thickness are each mm (mm). Table 5 shows the high order coefficient which can be used for each aspherical mirror in Embodiment 2, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 6 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 2, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 4

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-6.1892E-01	1.2773E-01	-1.2896E+02	5.1658E+03	-1.0686E+05	1.1933E+06	-6.8366E+06	1.5768E+07
S2	-8.3465E-02	-2.2393E-01	-4.2878E-01	1.8694E+01	-1.3104E+02	4.1846E+02	-4.9627E+02
S3	7.5799E-01	-2.4309E+01	1.7488E+02	-6.1961E+02	1.2502E+03	-1.3664E+03	6.2507E+02
S4	5.2612E-01	-6.1181E+00	2.2852E+01	-3.1708E+01	5.2909E+00	2.8883E+01	-2.1059E+01
S5	1.2037E-01	-5.5864E-01	1.3404E+00	-1.5354E+00	6.0539E-01	1.8385E-01	-1.9403E-01
S6	7.4721E-01	-3.1305E+00	6.8474E+00	-8.4486E+00	5.7363E+00	-2.0313E+00	2.9412E-01

table 5

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.46	-1.17	0.96	1.25	39.0

Table 6

Fig. 4A shows a distortion curve of the projection lens of Embodiment 2, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 4B shows a phase contrast curve of the projection lens of Embodiment 2, which shows the degree of contrast corresponding to the height of different image sources. 4A and 4B, the projection lens given in Embodiment 2 can achieve good image quality.

Example 3

A projection lens according to Embodiment 3 of the present application is described below with reference to FIGS. 5 to 6B. FIG. 5 is a schematic structural view of a projection lens according to Embodiment 3 of the present application.

As shown in FIG. 5, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a concave surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 7 shows the surface type, the radius of curvature, the thickness, the material, and the conical coefficient of each lens of the projection lens of Example 3, wherein the units of the radius of curvature and the thickness are each mm (mm). Table 8 shows the high order term coefficients which can be used for each aspherical mirror surface in Embodiment 3, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 9 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 3, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 7

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-6.1980E-01	1.4829E+00	-1.0886E+02	2.6894E+03	-3.8088E+04	3.0423E+05	-1.2765E+06	2.1924E+06
S2	-2.3028E-02	-5.6488E-01	3.8560E+00	-1.4708E+01	3.7359E+01	-5.9567E+01	5.3357E+01
S3	2.8415E-01	-1.5547E+01	1.0535E+02	-3.1863E+02	5.2285E+02	-4.5355E+02	1.6362E+02
S4	2.6411E-01	-2.9520E+00	6.9629E+00	8.5614E+00	-4.4627E+01	5.2762E+01	-2.0821E+01
S5	1.2815E-01	5.5936E-02	-1.7485E+00	5.7071E+00	-8.7590E+00	6.6571E+00	-2.0541E+00
S6	1.1895E+00	-4.2513E+00	8.5299E+00	-1.1025E+01	9.1752E+00	-4.5261E+00	9.8100E-01

Table 8

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.38	-1.18	0.92	1.18	40.4

Table 9

Fig. 6A shows a distortion curve of the projection lens of Embodiment 3, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 6B shows a phase contrast curve of the projection lens of Embodiment 3, which shows the degree of contrast corresponding to the height of the different image sources. 6A and 6B, the projection lens given in Embodiment 3 can achieve good image quality.

Example 4

A projection lens according to Embodiment 4 of the present application is described below with reference to FIGS. 7 to 8B. FIG. 7 is a block diagram showing the structure of a projection lens according to Embodiment 4 of the present application.

As shown in FIG. 7, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a convex surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a concave surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 10 shows the surface type, the radius of curvature, the thickness, the material, and the conical coefficient of each lens of the projection lens of Example 4, wherein the unit of the radius of curvature and the thickness are each mm (mm). Table 11 shows the high order coefficient which can be used for each aspherical mirror in Embodiment 4, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 12 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 4, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 10

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-3.5145E-01	3.3877E+00	-1.2590E+02	2.5101E+03	-3.0438E+04	2.1987E+05	-8.6569E+05	1.4287E+06
S2	4.4621E-02	-9.7582E-01	8.5362E+00	-3.5642E+01	8.9715E+01	-1.2256E+02	7.7019E+01
S3	1.3943E+00	-3.1143E+01	1.9678E+02	-6.1435E+02	1.0632E+03	-9.7281E+02	3.6739E+02
S4	4.2795E-01	-4.0234E+00	5.9908E+00	2.8176E+01	-9.9422E+01	1.1632E+02	-4.8224E+01
S5	9.1110E-02	-9.3198E-02	-6.2305E-01	2.6451E+00	-4.2917E+00	3.2800E+00	-1.0184E+00
S6	6.3528E-01	-2.1613E+00	3.1543E+00	-1.8876E+00	-1.4130E-01	5.5029E-01	-1.4698E-01

Table 11

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.50	-1.25	1.05	1.33	37.9

Table 12

Fig. 8A shows a distortion curve of the projection lens of Embodiment 4, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 8B shows a phase contrast curve of the projection lens of Embodiment 4, which shows the degree of contrast corresponding to the height of different image sources. 8A and 8B, the projection lens given in Embodiment 4 can achieve good image quality.

Example 5

A projection lens according to Embodiment 5 of the present application is described below with reference to FIGS. 9 to 10B. FIG. 9 is a block diagram showing the structure of a projection lens according to Embodiment 5 of the present application.

As shown in FIG. 9, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a convex surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 13 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 5, in which the unit of the radius of curvature and the thickness are each mm (mm). Table 14 shows the high order coefficient which can be used for each aspherical mirror surface in Embodiment 5, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 15 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 5, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 13

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-5.5208E-01	1.0127E+01	-4.5308E+02	1.1436E+04	-1.7137E+05	1.5033E+06	-7.1228E+06	1.3959E+07
S2	1.3662E-02	-5.7846E-02	-2.8482E+00	4.4723E+01	-2.1171E+02	4.8533E+02	-4.5509E+02
S3	1.3256E+00	-2.8217E+01	1.6643E+02	-4.6981E+02	7.2979E+02	-6.2046E+02	2.3818E+02
S4	7.7932E-01	-8.6775E+00	3.2783E+01	-6.7347E+01	9.9683E+01	-1.0211E+02	4.8428E+01
S5	3.5960E-02	2.0474E-01	-2.6623E+00	8.8113E+00	-1.3954E+01	1.0923E+01	-3.4544E+00
S6	2.0064E+00	-8.5164E+00	1.9452E+01	-2.7264E+01	2.3205E+01	-1.1037E+01	2.2359E+00

Table 14

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.28	-1.01	0.86	1.13	41.8

Table 15

Fig. 10A shows a distortion curve of the projection lens of Embodiment 5, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 10B shows a phase contrast curve of the projection lens of Embodiment 5, which shows the degree of contrast corresponding to the height of different image sources. 10A and 10B, the projection lens given in Embodiment 5 can achieve good image quality.

Example 6

A projection lens according to Embodiment 6 of the present application is described below with reference to FIGS. 11 to 12B. FIG. 11 is a block diagram showing the structure of a projection lens according to Embodiment 6 of the present application.

As shown in FIG. 11, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a convex surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 16 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 6, wherein the units of the radius of curvature and the thickness are each mm (mm). Table 17 shows the high order coefficient which can be used for each aspherical mirror surface in Embodiment 6, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 18 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 6, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 16

Face number	A4	A6	A8	A10	A12	A14	A16	A18	A20
S1	-1.1969E+00	3.1322E+01	-1.4173E+03	4.2564E+04	-8.8143E+05	1.2690E+07	-1.2054E+08	6.6879E+08	-1.6274E+09
S2	1.0478E+00	-2.6355E+01	3.3005E+02	-2.4463E+03	1.1163E+04	-2.5900E+04	2.2928E+04
S3	-6.1000E+00	1.6782E+01	2.5269E+01	2.4124E+01	-6.3420E+02	1.2601E+03	-6.9874E+02
S4	1.6787E-01	-9.5323E+00	5.2690E+01	-1.4951E+02	2.9832E+02	-3.8867E+02	2.2675E+02
S5	2.7753E-01	-1.6256E+00	3.7000E+00	-4.1561E+00	1.9998E+00	1.4795E-01	-3.4933E-01
S6	-1.4582E+00	1.0790E+01	-5.1480E+01	1.4920E+02	-2.6756E+02	2.9915E+02	-2.0258E+02	7.5867E+01	-1.2046E+01

Table 17

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
0.96	-0.54	0.64	0.90	48.6

Table 18

Fig. 12A shows a distortion curve of the projection lens of Embodiment 6, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 12B shows a phase contrast curve of the projection lens of Embodiment 6, which shows the degree of contrast corresponding to the height of different image sources. 12A and 12B, the projection lens given in Embodiment 6 can achieve good image quality.

Example 7

A projection lens according to Embodiment 7 of the present application is described below with reference to FIGS. 13 to 14B. FIG. 13 is a block diagram showing the structure of a projection lens according to Embodiment 7 of the present application.

As shown in FIG. 13, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a convex surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a concave surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 19 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 7, wherein the units of the radius of curvature and the thickness are each mm (mm). Table 20 shows the high order term coefficients which can be used for the respective aspherical mirrors in Embodiment 7, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 21 gives the effective focal lengths f1 to f3 of the respective lenses in Embodiment 7, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 19

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-5.2266E-01	7.4342E+00	-3.7164E+02	1.0270E+04	-1.6614E+05	1.5473E+06	-7.6633E+06	1.5505E+07
S2	1.0749E-02	-1.3238E-01	-3.9429E+00	6.3191E+01	-3.1657E+02	7.7479E+02	-7.8292E+02
S3	1.2437E+00	-2.7953E+01	1.6585E+02	-4.5832E+02	6.7705E+02	-5.3369E+02	1.8986E+02
S4	7.6509E-01	-8.7864E+00	3.4412E+01	-7.5415E+01	1.2083E+02	-1.3024E+02	6.3040E+01
S5	-5.7171E-02	5.4036E-01	-3.6128E+00	1.0641E+01	-1.6327E+01	1.2736E+01	-4.0621E+00
S6	1.8695E+00	-8.0855E+00	1.8799E+01	-2.6944E+01	2.3410E+01	-1.1307E+01	2.3135E+00

Table 20

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.27	-1.00	0.88	1.14	41.2

Table 21

Fig. 14A shows a distortion curve of the projection lens of Embodiment 7, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 14B shows a phase contrast curve of the projection lens of Embodiment 7, which shows the degree of contrast corresponding to the height of the different image sources. 14A and 14B, the projection lens given in Embodiment 7 can achieve good image quality.

Example 8

A projection lens according to Embodiment 8 of the present application is described below with reference to FIGS. 15 to 16B. FIG. 15 is a block diagram showing the structure of a projection lens according to Embodiment 8 of the present application.

As shown in FIG. 15, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a concave surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a concave surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 22 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 8, wherein the units of the radius of curvature and the thickness are each mm (mm). Table 23 shows the high order term coefficients which can be used for the respective aspherical mirrors in Embodiment 8, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 24 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 8, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 22

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-6.0747E-01	-5.0043E-01	-4.8371E+01	1.4939E+03	-2.3032E+04	1.8792E+05	-7.8154E+05	1.3107E+06
S2	-3.9087E-02	-6.9063E-01	4.9317E+00	-2.1518E+01	6.3213E+01	-1.1430E+02	1.0148E+02
S3	2.9803E-01	-1.5924E+01	1.0714E+02	-3.2092E+02	5.2005E+02	-4.4487E+02	1.5828E+02
S4	2.8620E-01	-3.4641E+00	9.5407E+00	1.9768E+00	-3.4461E+01	4.3674E+01	-1.7273E+01
S5	1.6749E-01	-2.9402E-01	-6.2753E-01	3.6972E+00	-6.7088E+00	5.5537E+00	-1.8178E+00
S6	1.2331E+00	-4.7630E+00	9.8880E+00	-1.2914E+01	1.0621E+01	-5.0844E+00	1.0639E+00

Table 23

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.41	-1.20	0.93	1.19	40.0

Table 24

Fig. 16A shows a distortion curve of the projection lens of Embodiment 8, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 16B shows a phase contrast curve of the projection lens of Embodiment 8, which shows the degree of contrast corresponding to the height of different image sources. 16A and 16B, the projection lens given in Embodiment 8 can achieve good image quality.

Example 9

A projection lens according to Embodiment 9 of the present application is described below with reference to FIGS. 17 to 18B. FIG. 17 is a block diagram showing the structure of a projection lens according to Embodiment 9 of the present application.

As shown in FIG. 17, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a concave surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 25 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 9, in which the unit of curvature radius and thickness are both millimeters (mm). Table 26 shows the high order coefficient which can be used for each aspherical mirror surface in Embodiment 9, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 27 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 9, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 25

Face number	A4	A6	A8	A10	A12	A14	A16	A18	A20
S1	-1.0755E+00	2.6961E+01	-1.1840E+03	2.9490E+04	-4.4202E+05	3.8523E+06	-1.7093E+07	2.1367E+07	5.3098E+07
S2	3.6296E-01	-8.4545E+00	7.2369E+01	-3.0870E+02	6.1282E+02	-5.5383E+01	-8.0025E+02
S3	2.7379E+00	-8.8848E+01	7.8062E+02	-3.4706E+03	8.6617E+03	-1.1428E+04	6.1686E+03
S4	-9.6767E-01	6.1297E+00	-4.9050E+01	2.3495E+02	-5.6186E+02	6.5619E+02	-3.0070E+02
S5	-2.5717E-01	1.4933E+00	-4.4257E+00	7.8461E+00	-8.1728E+00	4.6833E+00	-1.1668E+00
S6	-9.0794E-01	4.6693E+00	-1.4584E+01	3.0858E+01	-4.5254E+01	4.5812E+01	-3.0320E+01	1.1597E+01	-1.9194E+00

Table 26

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.17	-0.45	0.56	1.03	44.4

Table 27

Fig. 18A shows a distortion curve of the projection lens of Embodiment 9, which shows the amount of distortion magnitude corresponding to the height of different image sources. Fig. 18B shows a phase contrast curve of the projection lens of Embodiment 9, which shows the degree of contrast corresponding to the height of different image sources. 18A and 18B, the projection lens given in Embodiment 9 can achieve good image quality.

Example 10

A projection lens according to Embodiment 10 of the present application is described below with reference to FIGS. 19 to 20B. FIG. 19 is a block diagram showing the structure of a projection lens according to Embodiment 10 of the present application.

As shown in FIG. 19, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a convex surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 28 shows the surface type, the radius of curvature, the thickness, the material, and the conical coefficient of each lens of the projection lens of Example 10, wherein the units of the radius of curvature and the thickness are each mm (mm). Table 29 shows the high order coefficient which can be used for each aspherical mirror surface in Embodiment 10, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 30 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 10, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 28

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-5.4344E-01	7.5742E+00	-2.9889E+02	6.4500E+03	-8.3777E+04	6.4301E+05	-2.6673E+06	4.5653E+06
S2	4.6526E-02	-1.0958E+00	8.4839E+00	-3.0999E+01	6.6721E+01	-6.9153E+01	2.5180E+01
S3	1.5132E+00	-3.1597E+01	1.9594E+02	-6.0648E+02	1.0601E+03	-1.0123E+03	4.1764E+02
S4	6.9970E-01	-7.8749E+00	2.7604E+01	-4.3336E+01	3.8201E+01	-2.4671E+01	1.0822E+01
S5	6.2514E-02	2.1155E-01	-2.5123E+00	8.0403E+00	-1.2398E+01	9.4769E+00	-2.9318E+00
S6	1.8060E+00	-7.1875E+00	1.5496E+01	-2.0618E+01	1.6900E+01	-7.9127E+00	1.6085E+00

Table 29

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.30	-1.02	0.86	1.14	41.4

Table 30

Fig. 20A shows a distortion curve of the projection lens of Embodiment 10, which shows the amount of distortion magnitude corresponding to the height of different image sources. Fig. 20B shows a phase contrast curve of the projection lens of Embodiment 10, which shows the degree of contrast corresponding to the height of different image sources. 20A and 20B, the projection lens given in Embodiment 10 can achieve good image quality.

Example 11

A projection lens according to Embodiment 11 of the present application is described below with reference to FIGS. 21 to 22B. 21 is a schematic structural view of a projection lens according to Embodiment 11 of the present application.

As shown in FIG. 21, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a convex surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 31 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 11, wherein the units of the radius of curvature and the thickness are each mm (mm). Table 32 shows the high order coefficient which can be used for each aspherical mirror surface in Embodiment 11, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 33 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 11, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 31

Face number	A4	A6	A8	A10	A12	A14	A16	A18	A20
S1	-8.8314E-01	1.8219E+01	-7.4187E+02	1.7436E+04	-2.4724E+05	2.0042E+06	-7.2245E+06	-5.5607E+06	8.1994E+07

S2	7.1464E-01	-1.4348E+01	1.2796E+02	-6.2258E+02	1.6805E+03	-1.7857E+03	1.5959E+01
S3	9.5571E-01	-8.2607E+01	7.8834E+02	-3.6311E+03	9.4202E+03	-1.3034E+04	7.4211E+03
S4	-6.8603E-01	1.3984E+00	-2.1628E+01	1.4623E+02	-3.8954E+02	4.7110E+02	-2.1718E+02
S5	-2.3562E-01	1.1386E+00	-3.2020E+00	5.5612E+00	-5.6798E+00	3.1762E+00	-7.6310E-01
S6	-1.3424E+00	6.7464E+00	-2.1432E+01	4.5723E+01	-6.5670E+01	6.2628E+01	-3.7783E+01	1.2940E+01	-1.9056E+00

Table 32

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.12	-0.38	0.51	0.99	45.5

Table 33

Fig. 22A shows a distortion curve of the projection lens of Embodiment 11, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 22B shows a phase contrast curve of the projection lens of Embodiment 11, which shows the degree of contrast corresponding to the height of different image sources. 22A and 22B, the projection lens given in Embodiment 11 can achieve good image quality.

Example 12

A projection lens according to Embodiment 12 of the present application is described below with reference to FIGS. 23 to 24B. FIG. 23 is a block diagram showing the structure of a projection lens according to Embodiment 12 of the present application.

As shown in FIG. 23, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a convex surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a convex surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 34 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 12, in which the unit of the radius of curvature and the thickness are all millimeters (mm). Table 35 shows the high order coefficient which can be used for each aspherical mirror surface in Embodiment 12, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 36 gives the effective focal lengths f1 to f3 of the respective lenses in Embodiment 12, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 34

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-5.2167E-01	5.0678E+00	-2.8400E+02	8.5411E+03	-1.5091E+05	1.5238E+06	-8.0718E+06	1.7226E+07
S2	-8.8180E-03	-2.4532E-01	-4.3789E+00	7.6412E+01	-4.0349E+02	1.0309E+03	-1.1028E+03
S3	1.0661E+00	-2.7126E+01	1.6279E+02	-4.2768E+02	5.5568E+02	-3.5831E+02	1.1639E+02

S4	6.9061E-01	-9.0478E+00	3.8926E+01	-9.5691E+01	1.7090E+02	-1.9516E+02	9.6550E+01
S5	-1.1867E-01	6.6280E-01	-3.8916E+00	1.1429E+01	-1.7810E+01	1.4136E+01	-4.5763E+00
S6	1.8698E+00	-8.5535E+00	2.0765E+01	-3.0676E+01	2.7141E+01	-1.3210E+01	2.7043E+00

Table 35

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.26	-0.98	0.89	1.17	40.7

Table 36

Fig. 24A shows a distortion curve of the projection lens of Embodiment 12, which shows the amount of distortion magnitude corresponding to the height of different image sources. Fig. 24B shows a phase contrast curve of the projection lens of Embodiment 12, which shows the degree of contrast corresponding to the height of different image sources. 24A and 24B, the projection lens given in Embodiment 12 can achieve good image quality.

Example 13

A projection lens according to Embodiment 13 of the present application is described below with reference to FIGS. 25 to 26B. FIG. 25 is a block diagram showing the structure of a projection lens according to Embodiment 13 of the present application.

As shown in FIG. 25, a projection lens according to an exemplary embodiment of the present application sequentially includes an aperture STO, a first lens E1, a second lens E2, and a third lens E3 from the imaging side to the image source side along the optical axis.

The first lens E1 has a positive refractive power, the near imaging side surface S1 is a concave surface, the near image source side surface S2 is a convex surface, the second lens E2 has a negative refractive power, the near imaging side surface S3 is a concave surface, and the near image source side surface S4 is a convex surface. The third lens E3 has a positive power, the near imaging side surface S5 is a convex surface, and the near image source side surface S6 is a concave surface. Light from the image source S7 sequentially passes through the respective surfaces S6 to S1 and is finally projected onto a target object (not shown) in the space.

Table 37 shows the surface type, radius of curvature, thickness, material, and conical coefficient of each lens of the projection lens of Example 13, wherein the units of the radius of curvature and the thickness are each mm (mm). Table 38 shows the high order term coefficients which can be used for the respective aspherical mirrors in Embodiment 13, wherein each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1. Table 39 gives the effective focal lengths f1 to f3 of the lenses in Embodiment 13, the total effective focal length f of the projection lens, and the maximum half angle of view HFOV of the projection lens.

Table 37

Face number	A4	A6	A8	A10	A12	A14	A16	A18
S1	-6.7529E-01	-3.7121E+01	1.8238E+03	-5.2071E+04	8.6224E+05	-8.2354E+06	4.2107E+07	-8.9066E+07
S2	-8.7509E-02	6.8589E-01	-9.0612E+00	6.2604E+01	-2.6460E+02	7.3642E+02	-6.9510E+02
S3	-1.0053E+00	4.0725E+00	-1.5947E+01	6.9965E+01	-1.4198E+02	1.2616E+02	-3.9512E+01
S4	-4.6059E-01	4.1497E+00	-1.8898E+01	5.1774E+01	-8.0318E+01	6.8366E+01	-2.4489E+01
S5	6.6708E-01	-2.2463E+00	4.6972E+00	-5.9607E+00	4.2922E+00	-1.4813E+00	1.2814E-01

S6

1.5560E-01

-1.7301E+00

5.8220E+00

-1.0342E+01

1.0507E+01

-5.7168E+00

1.2689E+00

Table 38

F1 (mm)	F2 (mm)	F3 (mm)	f(mm)	HFOV(°)
1.34	-3.78	1.77	1.15	44.2

Table 39

Fig. 26A shows a distortion curve of the projection lens of Embodiment 13, which shows the amount of distortion amount corresponding to the height of different image sources. Fig. 26B shows a phase contrast curve of the projection lens of Embodiment 13, which shows the degree of contrast corresponding to the height of different image sources. 26A and 26B, the projection lens given in Embodiment 13 can achieve good image quality.

In summary, Embodiments 1 to 13 respectively satisfy the relationship shown in Table 40.

Conditional formula\example	1	2	3	4	5	6	7
f/f2	-0.85	-1.07	-0.99	-1.06	-1.11	-1.67	-1.14
SAG22/SAG21	1.09	1.01	1.01	1.00	1.04	1.07	1.04
F1/f	1.14	1.17	1.17	1.13	1.13	1.07	1.11
F2/f3	-1.30	-1.22	-1.28	-1.19	-1.17	-0.84	-1.14
R4/R3	2.06	2.07	2.08	2.04	2.28	3.75	2.31
f/IH	1.08	1.22	1.14	1.29	1.09	0.87	1.11
EPD/IH	0.51	0.54	0.62	0.61	0.43	0.46	0.39
CT2/ET2	1.20	1.03	1.03	1.01	1.09	1.12	1.07
f/R2	-1.70	-1.60	-1.50	-1.36	-1.43	-1.75	-1.46
DT11/DT31	0.31	0.33	0.38	0.37	0.29	0.30	0.27
f/CT2	3.98	5.26	4.94	5.33	4.45	3.08	4.41
(N1+N2)/2	1.62	1.62	1.63	1.62	1.62	1.53	1.62
CT2/T12	0.50	0.36	0.37	0.43	0.51	0.96	0.53
f/R6	-0.10	-0.002	0.00	0.57	-0.06	-0.54	0.01

Conditional formula\example	8	9	10	11	12	13
f/f2	-1.00	-2.28	-1.12	-2.64	-1.19	-0.30
SAG22/SAG21	1.01	0.89	1.02	0.87	1.02	1.24
F1/f	1.18	1.14	1.14	1.13	1.08	1.16
F2/f3	-1.28	-0.80	-1.18	-0.73	-1.11	-2.14
R4/R3	2.08	4.25	2.25	4.86	2.35	1.67
f/IH	1.16	1.00	1.11	0.96	1.13	1.12
EPD/IH	0.64	0.54	0.55	0.51	0.35	0.54
CT2/ET2	1.03	0.76	1.05	0.73	1.03	1.51
f/R2	-1.51	-1.68	-1.42	-1.66	-1.49	-1.75
DT11/DT31	0.39	0.33	0.35	0.31	0.26	0.33
f/CT2	5.00	5.21	4.68	5.27	4.42	3.29
(N1+N2)/2	1.63	1.53	1.62	1.53	1.62	1.62
CT2/T12	0.37	0.48	0.47	0.49	0.53	0.59
f/R6	0.04	-0.74	-0.01	-0.75	-0.001	0.73

Table 40

The above description is only a preferred embodiment of the present application and a description of the principles of the applied technology. It should be understood by those skilled in the art that the scope of the invention referred to in the present application is not limited to the specific combination of the above technical features, and should also be covered by the above technical features without departing from the inventive concept. Other technical solutions formed by any combination of their equivalent features. For example, the above features are combined with the technical features disclosed in the present application, but are not limited to the technical features having similar functions.

Claims (34)

1. The projection lens includes, in order from the imaging side to the image source side along the optical axis, a first lens, a second lens, and a third lens, wherein

   The first lens has a positive power;

   The second lens has a negative power, the near imaging side is a concave surface, and the near image source side is a convex surface;

   The third lens has a positive power and a near imaging side thereof is a convex surface;

   The total effective focal length f of the projection lens and the center thickness CT2 of the second lens on the optical axis satisfy 3.0 ≤ f / CT2 < 5.5.
2. The projection lens according to claim 1, wherein a center thickness CT2 of the second lens on the optical axis and an edge thickness ET2 of the second lens at a maximum effective radius satisfy 0.5<CT2/ET2 ≤1.6.
3. The projection lens according to claim 1, wherein a center thickness CT2 of the second lens on the optical axis and a distance between the first lens and the second lens on the optical axis T12 satisfies 0.3<CT2/T12<1.0.
4. The projection lens according to claim 1, wherein an effective focal length f1 of the first lens and a total effective focal length f of the projection lens satisfy 1.0 < f1/f < 1.3.
5. The projection lens according to claim 1, wherein a total effective focal length f of the projection lens and an effective focal length f2 of the second lens satisfy -3.0 < f/f2 < 0.
6. The projection lens according to claim 1, wherein an effective focal length f2 of the second lens and an effective focal length f3 of the third lens satisfy -2.5 < f2 / f3 < - 0.5.
7. The projection lens according to claim 5, wherein a radius of curvature R4 of the near-image source side of the second lens and a radius of curvature R3 of the near-imaging side of the second lens satisfy 1.5<R4/R3<5.0 .
8. The projection lens according to claim 4, wherein a total effective focal length f of the projection lens and a radius of curvature R2 of a near-image source side of the first lens satisfy -1.9 < f / R2 < - 1.3.
9. The projection lens according to claim 1, wherein an intersection of a near-image source side of the second lens and the optical axis to an effective radius vertex of the second lens near-source side is at the optical axis The distance SAG21 of the upper distance SAG22 from the intersection of the near imaging side of the second lens and the optical axis to the effective radius apex of the near imaging side of the second lens on the optical axis satisfies 0.8<SAG22/SAG21< 1.3.
10. The projection lens according to claim 1, wherein a refractive index N1 of the first lens and a refractive index N2 of the second lens satisfy (N1 + N2)/2 ≤ 1.63.
11. The projection lens according to claim 1, wherein an entrance pupil diameter EPD of the projection lens and a half IH of a diagonal length of an image source region of the projection lens satisfy 0.2 < EPD/IH < 0.7.
12. The projection lens according to claim 11, wherein a total effective focal length f of the projection lens and a half IH of a diagonal length of the image source region of the projection lens satisfy 0.8 < f / IH ≤ 1.3.
13. The projection lens according to claim 1, wherein a maximum effective radius DT11 of a near-imaging side of the first lens and a maximum effective radius DT31 of a near-imaging side of the third lens satisfy 0.2<DT11/DT31< 0.5.
14. The projection lens according to any one of claims 1 to 13, wherein a near image source side of the third lens is a convex surface; a total effective focal length f of the projection lens is close to the third lens The radius of curvature R6 of the image source side satisfies -1.0 < f / R6 < 0.
15. The projection lens according to any one of claims 1 to 13, wherein a near image source side of the third lens is a concave surface; an effective focal length f2 of the second lens is effective with respect to the third lens The focal length f3 satisfies -2.5 < f2 / f3 ≤ -1.1.
16. The projection lens according to claim 15, wherein a radius of curvature R4 of the near image source side of the second lens and a radius of curvature R3 of the near image side of the second lens satisfy 1.6 < R4 / R3 < 2.5 .
17. The projection lens according to claim 16, wherein a center thickness CT2 of the second lens on the optical axis and a distance between the first lens and the second lens on the optical axis T12 satisfies 0.3<CT2/T12≤0.6.
18. The projection lens includes, in order from the imaging side to the image source side along the optical axis, a first lens, a second lens, and a third lens, wherein

    The first lens has a positive power;

    The second lens has a negative power, the near imaging side is a concave surface, and the near image source side is a convex surface;

    The third lens has a positive power and a near imaging side thereof is a convex surface;

    The effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy -2.5 < f2 / f3 < -0.5.
19. The projection lens according to claim 18, wherein the total effective focal length f of the projection lens and the effective focal length f2 of the second lens satisfy -3.0 < f / f2 < 0.
20. The projection lens according to claim 18, wherein an intersection of a near-source source side of the second lens and the optical axis to an effective radius vertex of the second lens near-source side is at the optical axis The distance SAG21 of the upper distance SAG22 from the intersection of the near imaging side of the second lens and the optical axis to the effective radius apex of the near imaging side of the second lens on the optical axis satisfies 0.8<SAG22/SAG21< 1.3.
21. The projection lens according to claim 18, wherein a center thickness CT2 of the second lens on the optical axis and an edge thickness ET2 of the second lens at a maximum effective radius satisfy 0.5<CT2/ET2 ≤1.6.
22. The projection lens according to claim 18, wherein a radius of curvature R4 of the near-image source side of the second lens and a radius of curvature R3 of the near-imaging side of the second lens satisfy 1.5 < R4/R3 < 5.0 .
23. The projection lens according to claim 18, wherein an effective focal length f1 of the first lens and a total effective focal length f of the projection lens satisfy 1.0 < f1/f < 1.3.
24. The projection lens according to claim 18, wherein a total effective focal length f of the projection lens and a radius of curvature R2 of a near-image source side of the first lens satisfy -1.9 < f / R2 < - 1.3.
25. The projection lens according to claim 18, wherein an entrance pupil diameter EPD of the projection lens and a half IH of a diagonal length of an image source region of the projection lens satisfy 0.2 < EPD/IH < 0.7.
26. The projection lens according to claim 18, wherein a total effective focal length f of the projection lens and a half IH of a diagonal length of the image source region of the projection lens satisfy 0.8 < f / IH ≤ 1.3.
27. The projection lens according to claim 18, wherein a maximum effective radius DT11 of the near-imaging side of the first lens and a maximum effective radius DT31 of the near-imaging side of the third lens satisfy 0.2 < DT11 / DT31 < 0.5.
28. The projection lens according to claim 21, wherein a total effective focal length f of the projection lens and a center thickness CT2 of the second lens on the optical axis satisfy 3.0 ≤ f / CT2 < 5.5.
29. The projection lens according to claim 21, wherein a center thickness CT2 of the second lens on the optical axis and a distance between the first lens and the second lens on the optical axis T12 satisfies 0.3<CT2/T12<1.0.
30. The projection lens according to claim 18, wherein the refractive index N1 of the first lens and the refractive index N2 of the second lens satisfy (N1 + N2)/2 ≤ 1.63.
31. The projection lens according to any one of claims 18 to 30, wherein a near image source side of the third lens is a convex surface; a total effective focal length f of the projection lens is close to the third lens The radius of curvature R6 of the image source side satisfies -1.0 < f / R6 < 0.
32. The projection lens according to any one of claims 18 to 30, wherein a near image source side of the third lens is a concave surface; an effective focal length f2 of the second lens is effective with the third lens The focal length f3 satisfies -2.5 < f2 / f3 ≤ -1.1.
33. The projection lens according to claim 32, wherein a radius of curvature R4 of the near image source side of the second lens and a radius of curvature R3 of the near image side of the second lens satisfy 1.6 < R4 / R3 < 2.5 .
34. The projection lens according to claim 33, wherein a center thickness CT2 of the second lens on the optical axis and a distance between the first lens and the second lens on the optical axis T12 satisfies 0.3<CT2/T12≤0.6.

Images