High-resolution projection lens

Abstract

The invention discloses a high-resolution projection lens, which comprises a first lens group, an aperture diaphragm, a second lens group, a prism and a DMD chip which are sequentially arranged from an amplification side to a reduction side along an optical axis direction, and is characterized in that the first lens group and the second lens group both have positive focal power and comprise at least one lens, each lens is a spherical lens, and the aperture diaphragm is arranged between the first lens group and the second lens group; the following conditions are met: 5.3 lt; fa / f00lt; 5.6); 2.1 lt; fb / f00lt; 2, 4; wherein fa is the focal length of the first lens group, fb is the focal length of the second lens group, f00 is the effective focal length of the high-resolution projection lens, and the unit is mm. The projection lens is high in resolution, good in imaging quality, convenient to process and assemble and low in cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of projection lenses, and particularly relates to a high-resolution projection lens. Background Art

[0002] With the rapid development of semiconductor technology, projection display technology has been continuously progressing, and projection devices have gradually been applied to the fields of home, business, education, and industrial inspection. At the same time, the requirements for projection display technology are also getting higher and higher, such as high-definition pictures, high-brightness images, rich colors, and high-contrast displays.

[0003] Due to the requirement of high resolution for projection lenses, a larger F-number can reduce aberrations and improve the uniformity of edge image quality. However, the design of large-aperture projection lenses is itself complex and costly, and affected by the complex optical path design of projection lenses, such as the combination of prisms and mirrors at the rear end, which makes it difficult to reduce the size of the projection lens. In order to match the projection lens with the prism, a longer back working distance needs to be reserved, increasing the design difficulty.

[0004] In addition, in some existing projection lens technologies, there are also other ways to improve projection quality. For example, by adopting aspherical and free-form surface technologies in optical design, the design difficulty of the optical system can be reduced to a certain extent, and the system structure can be simplified. However, the processing cost of aspherical and free-form surface technologies is high, and the assembly is difficult, which will increase costs and reduce production efficiency. In addition, technologies such as DLP, LCoS, and XPR are used in the opto-mechanical system to achieve high resolution of the projection lens. Among them, the XPR technology can achieve better balance between cost and performance compared with other technologies, and can be compatible with high frame rates to promote the popularization of 4K projection. However, the XPR technology has certain requirements for the resolution (MTF) of the projection lens. For example, the MTF in the mid-frequency range (50 - 150 lp / mm) needs to be greater than 0.6 to ensure the sharpness of the image edge and texture details, and the MTF at high frequency 185 lp / mm needs to be greater than 0.3 to resolve the sub-pixel displacement signal generated by XPR, and the full field of view needs to ensure consistency, and the requirements for chromatic aberration and aberration are also very strict. Therefore, in view of the problem that it is difficult to balance the aberration, F-number, distortion, and cost of projection lenses in the prior art, a high-resolution projection lens is proposed. Summary of the Invention

[0005] The purpose of the present invention is to propose a high-resolution projection lens aiming at the above problems, which has high resolution, good imaging quality, is convenient for processing and assembly, and has low cost.

[0006] To achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0007] A high-resolution projection lens proposed by the present invention includes a first lens group, an aperture stop, a second lens group, a prism, and a DMD chip, which are sequentially arranged along the optical axis direction from the magnifying side to the reducing side, where:

[0008] Both the first lens group and the second lens group have positive optical powers and include at least one lens. Each lens is a spherical lens and satisfies the following conditions:

[0009] 5.3 < fa / f00 < 5.6; 2.1 < fb / f00 < 2.4;

[0010] Wherein, fa is the focal length of the first lens group, fb is the focal length of the second lens group, and f00 is the effective focal length of the high-resolution projection lens, and the unit of all is mm.

[0011] Preferably, the first lens group includes a first lens with positive optical power, a second lens with negative optical power, a third lens with negative optical power, a fourth lens with positive optical power, and a fifth lens with positive optical power, which are sequentially arranged along the optical axis direction from the magnifying side to the reducing side; the second lens group includes a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power, a ninth lens with negative optical power, a tenth lens with positive optical power, and an eleventh lens with positive optical power, which are sequentially arranged along the optical axis direction from the magnifying side to the reducing side. The ninth lens and the tenth lens form a cemented lens with negative optical power.

[0012] Preferably, the high-resolution projection lens also satisfies the following conditions:

[0013] 4.5 < f1 / f00 < 4.8; -2.4 < f2 / f00 < -2.1; -1.1 < f3 / f00 < -0.8;

[0014] 2.2 < f4 / f00 < 2.5; 2.8 < f5 / f00 < 3.1; 2.2 < f6 / f00 < 2.5;

[0015] -2.0 < f7 / f00 < -1.7; 2.1 < f8 / f00 < 2.4; -1 < f9 / f00 < -0.7;

[0016] 1.5 < f10 / f00 < 1.8; 1.8 < f11 / f00 < 2.1;

[0017] Wherein, f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11 correspond to the focal lengths of the first lens to the eleventh lens in sequence, and the unit is mm.

[0018] Preferably, the magnifying side surface of the first lens is concave, and the reducing side surface is convex; the magnifying side surface of the second lens is concave, and the reducing side surface is concave; the magnifying side surface of the third lens is convex, and the reducing side surface is concave; the magnifying side surface of the fourth lens is convex, and the reducing side surface is convex; the magnifying side surface of the fifth lens is convex, and the reducing side surface is convex; the magnifying side surface of the sixth lens is concave, and the reducing side surface is convex; the magnifying side surface of the seventh lens is concave, and the reducing side surface is concave; the magnifying side surface of the eighth lens is concave, and the reducing side surface is convex; the magnifying side surface of the ninth lens is convex, and the reducing side surface is concave; the magnifying side surface of the tenth lens is concave, and the reducing side surface is convex; the magnifying side surface of the eleventh lens is concave, and the reducing side surface is convex.

[0019] Preferably, the high-resolution projection lens further satisfies the following conditions:

[0020] 40 < R11 < 60; -140 < R12 < -120; 20 < R21 < 40; 1 < R22 < 20;

[0021] -30 < R31 < -10; 15 < R32 < 35; -55 < R41 < -34; -10 < R42 < -30;

[0022] -200 < R51 < -50; -10 < R52 < -40; 10 < R61 < 30; -80 < R62 < -60;

[0023] 50 < R71 < 80; 10 < R72 < 30; 20 < R81 < 50; -50 < R82 < -20;

[0024] -30 < R91 < -10; 10 < R92 < 30; 10 < R101 < 30; -40 < R102 < -10;

[0025] 40 < R111 < 70; -50 < R112 < -30;

[0026] Wherein, R11, R21, R31, R41, R51, R61, R71, R81, R91, R101, R111 correspond to the curvature radii of the magnifying side surfaces of the first to eleventh lenses in sequence, and R12, R22, R32, R42, R52, R62, R72, R82, R92, R102, R112 correspond to the curvature radii of the reducing side surfaces of the first to eleventh lenses in sequence, with the unit of mm.

[0027] Preferably, the high-resolution projection lens further satisfies the following conditions:

[0028] 1.5 < T1 < 4.0; 1.0 < T2 < 3.5; 0.85 < T3 < 1.5; 2.5 < T4 < 4.0;

[0029] 4.0 < T5 < 5.5; 4.0 < T6 < 5.5; 0.9 < T7 < 2.0; 2.0 < T8 < 4.0;

[0030] 0.8 < T9 < 3.0; 3.0 < T10 < 5.0; 2.5 < T11 < 4.5; 0.09 < t01 < 0.2;

[0031] 4.7 < t02 < 5.5; 1.5 < t03 < 3; 9.5 < t04 < 17; 15 < t05 < 26.5;

[0032] 0.1 < t06 < 0.75; 1.0 < t07 < 1.5; 0.5 < t08 < 1.5; 0.1 < t09 < 2.5;

[0033] Wherein, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11 respectively correspond to the thicknesses of the first lens to the eleventh lens, with the unit of mm, t01 is the air gap between the first lens and the second lens, t02 is the air gap between the second lens and the third lens, t03 is the air gap between the third lens and the fourth lens, t04 is the air gap between the fourth lens and the fifth lens, t05 is the air gap between the fifth lens and the sixth lens, t06 is the air gap between the sixth lens and the seventh lens, t07 is the air gap between the seventh lens and the eighth lens, t08 is the air gap between the eighth lens and the ninth lens, and t09 is the air gap between the tenth lens and the eleventh lens.

[0034] Preferably, the first lens group further includes a vignetting diaphragm, and the vignetting diaphragm is located between the fourth lens and the fifth lens, or the vignetting diaphragm is located between the aperture stop and the sixth lens.

[0035] Preferably, the high-resolution projection lens further satisfies the following conditions:

[0036] 11 < TTL / H < 12.2; 0.25 < BFL / TTL < 0.277

[0037] Wherein, TTL is the total length of the high-resolution projection lens, H is the image height of the imaging surface on the reduced side of the high-resolution projection lens, and BFL is the back focal length of the high-resolution projection lens.

[0038] Preferably, each lens is a glass spherical lens and satisfies the following conditions:

[0039] 1.48 < Nd < 2.0, 17 < Vd < 80;

[0040] Wherein, Nd is the refractive index and Vd is the Abbe number;

[0041] The size of the DMD chip is 8.707 mm × 4.918 mm, the pixel size is 0.0045 mm, and the transmittance of the entire lens assembly is greater than 85% at a wavelength of 450 nm and greater than 90% at a wavelength of 650 nm.

[0042] Preferably, the high-resolution projection lens adopts an image-space telecentric optical path and satisfies the following conditions:

[0043] 1.2 < TR = (2 * f00) / H < 1.5; WD = 20 inch to 50 inch;

[0044] F = f00 / D = 2.2; CRA < 1.0°;

[0045] Wherein, TR is the projection ratio, H is the image height of the imaging surface on the reduction side of the high-resolution projection lens, WD is the working distance of the high-resolution projection lens, F is the F-number of the high-resolution projection lens, D is the relative aperture, and CRA is the telecentricity.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] The high-resolution projection lens includes a first lens group, an aperture stop, a second lens group, a prism, and a DMD chip arranged in sequence along the optical axis direction from the magnification side to the reduction side. The first lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; the second lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens. The ninth lens and the tenth lens are cemented lenses, which are beneficial for correcting secondary spectra. All lenses are glass spherical lenses, with low cost, high thermal stability, easy processing, and simple assembly; and by reasonably setting the parameters of each lens, the relative illumination of the entire field of view is higher than 0.7, especially the relative illumination of the 0.8 field of view is higher than 0.85, the optical distortion can reach within 1.5%, the vertical chromatic aberration and the spot diagram of the entire field of view are both less than 0.5 pixel, the imaging quality is good, and on the basis of the MTF of the resolution of 111 lp / mm > 0.6, it is compatible with the XPR technology to achieve high-definition pictures, high-brightness images, and projection displays with rich colors, obtaining a low-cost, small-distortion, 1080P high-resolution projection effect, and improving the user experience. Description of the Drawings

[0048] Figure 1 It is the optical structure diagram of the high-resolution projection lens according to Embodiment 1 of the present invention;

[0049] Figure 2 It is the MTF diagram of the transfer function of each field of view of the high-resolution projection lens according to Embodiment 1 of the present invention;

[0050] Figure 3Spot diagram of the high-resolution projection lens according to Embodiment 1 of the present invention;

[0051] Figure 4 Field curvature and distortion diagram of the high-resolution projection lens according to Embodiment 1 of the present invention;

[0052] Figure 5 Lateral chromatic aberration diagram of the high-resolution projection lens according to Embodiment 1 of the present invention;

[0053] Figure 6 Optical structure diagram of the high-resolution projection lens according to Embodiment 2 of the present invention;

[0054] Figure 7 MTF diagram of the transfer function of each field of view of the high-resolution projection lens according to Embodiment 2 of the present invention;

[0055] Figure 8 Spot diagram of the high-resolution projection lens according to Embodiment 2 of the present invention;

[0056] Figure 9 Field curvature and distortion diagram of the high-resolution projection lens according to Embodiment 2 of the present invention;

[0057] Figure 10 Lateral chromatic aberration diagram of the high-resolution projection lens according to Embodiment 2 of the present invention;

[0058] Figure 11 Optical structure diagram of the high-resolution projection lens according to Embodiment 3 of the present invention;

[0059] Figure 12 MTF diagram of the transfer function of each field of view of the high-resolution projection lens according to Embodiment 3 of the present invention;

[0060] Figure 13 Spot diagram of the high-resolution projection lens according to Embodiment 3 of the present invention;

[0061] Figure 14 Field curvature and distortion diagram of the high-resolution projection lens according to Embodiment 3 of the present invention;

[0062] Figure 15 Lateral chromatic aberration diagram of the high-resolution projection lens according to Embodiment 3 of the present invention.

[0063] Explanation of reference numerals: G1, the first lens group; STO, the aperture stop; G2, the second lens group; G3, the prism; G4, the protective glass; 1, the first lens; 2, the second lens; 3, the third lens; 4, the fourth lens; AV, the vignetting stop; 5, the fifth lens; 6, the sixth lens; 7, the seventh lens; 8, the eighth lens; 9, the ninth lens; 10, the tenth lens; 11, the eleventh lens. Detailed implementation manners

[0064] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0065] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present application. The terms used in the specification of the present application herein are only for the purpose of describing specific embodiments, and are not intended to limit the present application.

[0066] As Figures 1 - 15 shown, a high-resolution projection lens includes a first lens group G1, an aperture stop STO, a second lens group G2, a prism G3, and a DMD chip, which are sequentially arranged along the optical axis direction from the magnifying side to the reducing side, where:

[0067] Both the first lens group G1 and the second lens group G2 have positive optical powers and include at least one lens, and each lens is a spherical lens and satisfies the following conditions:

[0068] 5.3 < fa / f00 < 5.6; 2.1 < fb / f00 < 2.4;

[0069] wherein, fa is the focal length of the first lens group G1, fb is the focal length of the second lens group G2, and f00 is the effective focal length of the high-resolution projection lens, and the units are all mm.

[0070] Among them, the high-resolution projection lens includes a first lens group G1 with positive optical power, an aperture stop STO, a second lens group G2 with positive optical power, a prism G3, and a DMD chip, which are sequentially arranged along the optical axis direction from the magnifying side to the reducing side. A protective glass G4 can also be arranged between the prism G3 and the DMD chip to protect the DMD chip. All lenses are glass spherical lenses, which are low in cost, high in thermal stability, easy to process, and simple to assemble.

[0071] In one embodiment, the first lens group G1 includes a first lens 1 with a positive focal power, a second lens 2 with a negative focal power, a third lens 3 with a negative focal power, a fourth lens 4 with a positive focal power, and a fifth lens 5 with a positive focal power, which are sequentially arranged along the optical axis direction from the magnifying side to the reducing side; the second lens group G2 includes a sixth lens 6 with a positive focal power, a seventh lens 7 with a negative focal power, an eighth lens 8 with a positive focal power, a ninth lens 9 with a negative focal power, a tenth lens 10 with a positive focal power, and an eleventh lens 11 with a positive focal power, which are sequentially arranged along the optical axis direction from the magnifying side to the reducing side. The ninth lens 9 and the tenth lens 10 form a cemented lens with a negative focal power.

[0072] Among them, the first lens group in this embodiment includes 5 coaxial spherical lenses, and the second lens group includes 6 coaxial spherical lenses.

[0073] In one embodiment, the high-resolution projection lens also satisfies the following conditions:

[0074] 4.5 < f1 / f00 < 4.8; -2.4 < f2 / f00 < -2.1; -1.1 < f3 / f00 < -0.8;

[0075] 2.2 < f4 / f00 < 2.5; 2.8 < f5 / f00 < 3.1; 2.2 < f6 / f00 < 2.5;

[0076] -2.0 < f7 / f00 < -1.7; 2.1 < f8 / f00 < 2.4; -1 < f9 / f00 < -0.7;

[0077] 1.5 < f10 / f00 < 1.8; 1.8 < f11 / f00 < 2.1;

[0078] Among them, f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11 respectively correspond to the focal lengths of the first lens 1 to the eleventh lens 11, with the unit of mm.

[0079] In one embodiment, the magnifying side surface of the first lens 1 is concave, and the reducing side surface is convex; the magnifying side surface of the second lens 2 is concave, and the reducing side surface is concave; the magnifying side surface of the third lens 3 is convex, and the reducing side surface is concave; the magnifying side surface of the fourth lens 4 is convex, and the reducing side surface is convex; the magnifying side surface of the fifth lens 5 is convex, and the reducing side surface is convex; the magnifying side surface of the sixth lens 6 is concave, and the reducing side surface is convex; the magnifying side surface of the seventh lens 7 is concave, and the reducing side surface is concave; the magnifying side surface of the eighth lens 8 is concave, and the reducing side surface is convex; the magnifying side surface of the ninth lens 9 is convex, and the reducing side surface is concave; the magnifying side surface of the tenth lens 10 is concave, and the reducing side surface is convex; the magnifying side surface of the eleventh lens 11 is concave, and the reducing side surface is convex.

[0080] Among them, the first lens 1 is a biconvex positive lens, which can effectively reduce the beam height and reduce the field aberration; the fourth lens 4 is a meniscus lens, which can minimize the spherical aberration to the greatest extent. The ninth lens 9 and the tenth lens 10 form a cemented lens, which can correct the secondary spectrum.

[0081] In one embodiment, the high-resolution projection lens further satisfies the following conditions:

[0082] 40 < R11 < 60; -140 < R12 < -120; 20 < R21 < 40; 1 < R22 < 20;

[0083] -30 < R31 < -10; 15 < R32 < 35; -55 < R41 < -34; -10 < R42 < -30;

[0084] -200 < R51 < -50; -10 < R52 < -40; 10 < R61 < 30; -80 < R62 < -60;

[0085] 50 < R71 < 80; 10 < R72 < 30; 20 < R81 < 50; -50 < R82 < -20;

[0086] -30 < R91 < -10; 10 < R92 < 30; 10 < R101 < 30; -40 < R102 < -10;

[0087] 40 < R111 < 70; -50 < R112 < -30;

[0088] Among them, R11, R21, R31, R41, R51, R61, R71, R81, R91, R101, R111 respectively correspond to the radii of curvature of the magnifying side surfaces of the first lens 1 to the eleventh lens 11, and R12, R22, R32, R42, R52, R62, R72, R82, R92, R102, R112 respectively correspond to the radii of curvature of the reducing side surfaces of the first lens 1 to the eleventh lens 11, with the unit of mm.

[0089] In one embodiment, the high-resolution projection lens further satisfies the following conditions:

[0090] 1.5 < T1 < 4.0; 1.0 < T2 < 3.5; 0.85 < T3 < 1.5; 2.5 < T4 < 4.0;

[0091] 4.0 < T5 < 5.5; 4.0 < T6 < 5.5; 0.9 < T7 < 2.0; 2.0 < T8 < 4.0;

[0092] 0.8 < T9 < 3.0; 3.0 < T10 < 5.0; 2.5 < T11 < 4.5; 0.09 < t01 < 0.2;

[0093] 4.7 < t02 < 5.5; 1.5 < t03 < 3; 9.5 < t04 < 17; 15 < t05 < 26.5;

[0094] 0.1 < t06 < 0.75; 1.0 < t07 < 1.5; 0.5 < t08 < 1.5; 0.1 < t09 < 2.5;

[0095] Among them, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11 respectively correspond to the thicknesses of the first lens 1 to the eleventh lens 11, with the unit of mm, t01 is the air gap between the first lens 1 and the second lens 2, t02 is the air gap between the second lens 2 and the third lens 3, t03 is the air gap between the third lens 3 and the fourth lens 4, t04 is the air gap between the fourth lens 4 and the fifth lens 5, t05 is the air gap between the fifth lens 5 and the sixth lens 6, t06 is the air gap between the sixth lens 6 and the seventh lens 7, t07 is the air gap between the seventh lens 7 and the eighth lens 8, t08 is the air gap between the eighth lens 8 and the ninth lens 9, and t09 is the air gap between the tenth lens 10 and the eleventh lens 11.

[0096] In one embodiment, the first lens group G1 further includes a vignetting diaphragm AV, which is located between the fourth lens 4 and the fifth lens 5, or the vignetting diaphragm AV is located between the aperture stop STO and the sixth lens 6. Among them, the vignetting diaphragm AV can reduce the aperture towards the magnifying side lenses (i.e., each lens in the first lens group G1), and adjust the telecentricity CRA < 1.0° of the high-resolution projection lens.

[0097] In one embodiment, the high-resolution projection lens further satisfies the following conditions:

[0098] 11 < TTL / H < 12.2; 0.25 < BFL / TTL < 0.277

[0099] Among them, TTL is the total length of the high-resolution projection lens, H is the image height of the imaging surface on the reducing side of the high-resolution projection lens, and BFL is the back focal length of the high-resolution projection lens.

[0100] In one embodiment, each lens is a glass spherical lens and satisfies the following conditions:

[0101] 1.48 < Nd < 2.0, 17 < Vd < 80;

[0102] Among them, Nd is the refractive index and Vd is the Abbe number;

[0103] The size of the DMD chip is 8.707 mm × 4.918 mm, the pixel size is 0.0045 mm, and the transmittance of the whole set of lenses is greater than 85% at a wavelength of 450 nm and greater than 90% at a wavelength of 650 nm.

[0104] In one embodiment, the high-resolution projection lens adopts an image-side telecentric optical path and satisfies the following conditions:

[0105] 1.2 < TR = (2*f00) / H < 1.5; WD = 20 inch to 50 inch;

[0106] F = f00 / D = 2.2; CRA < 1.0°;

[0107] Among them, TR is the projection ratio, H is the image height of the imaging surface on the reducing side of the high-resolution projection lens, WD is the working distance of the high-resolution projection lens, F is the F-number of the high-resolution projection lens, D is the relative aperture, and CRA is the telecentricity.

[0108] The high-resolution projection lens consists of eleven glass lenses. The first lens 1 on the magnification side is a positive lens, which reduces the height of the light rays, facilitating the reduction of the front-end aperture of the lens and the volume of the lens. The third lens 3 shares the optical power of the second lens 2, provides a deflection angle for the marginal rays, reduces the field aberration, and improves the resolution of the lens. If the vignetting diaphragm AV is arranged between the fourth lens 4 and the fifth lens 5, it can block the light, cut off the light beam with a large incident angle, reduce the aberration of the marginal field, and the vignetting diaphragm AV is located in front of the aperture stop STO and close to the magnification side. While improving the system performance (aberration, field curvature, resolution), reducing its aperture can reduce the telecentricity of the system; the sixth lens 7 is a biconvex lens, which effectively reduces the height of the light rays emerging from the aperture stop STO, reduces the aperture aberration, and the material with its low refractive index and high Abbe number can effectively compensate for the blurring of the projection image under high and low temperatures; the seventh lens 7 is a negative lens, which forms a positive-negative combination with the sixth lens 6 to effectively improve the projection performance of the projection system; the eighth lens 8 is a biconvex lens, which can effectively smooth the light trend, reduce the system sensitivity, improve the system yield, reduce the cost, and uses a material similar to that of the sixth lens 6, both of which are materials with low refractive index and high Abbe number, further compensating for the back focal shift caused by high and low temperatures; the ninth lens 9 and the tenth lens 10 form a doublet lens group, which can effectively correct the chromatic aberration, spherical aberration and coma of the projection system and improve the system performance; the eleventh lens 11 is used as the field lens in the projection system, placed at the reduction end of the projection system, close to the prism G3 to compensate for the field curvature and distortion in the system, which helps to improve the resolution.

[0109] For easy understanding, the following will be elaborated in detail through specific embodiments.

[0110] Embodiment 1:

[0111] As Figures 1 - 5 shown, in this embodiment, a protective glass G4 is further provided between the DMD chip and the prism G3 to protect the DMD chip, and the working distance WD = 1190mm, F = 2.2, TR = 1.474, TTL / H = 12.18.

[0112] The parameters such as the surface type, radius of curvature, thickness, and material of each lens are shown in the data in Table 1:

[0113] Table 1

[0114]

[0115]

[0116] According to the above parameters, as Figure 2As shown, it is the MTF (Modulation Transfer Function) graph of each field image plane of a high-resolution projection lens at a working distance WD = 1190 mm. The abscissa is the spatial frequency, and the ordinate is the OTF (Optical Transfer Function) modulus value. The full field @110 lp / mm > 0.6, and the curve is close to the diffraction limit, indicating that the imaging quality of the lens is clear. As Figure 3 shown, it is the spot diagram, and the size of the RMS points in the full field is less than 0.5 pixel. As Figure 4 shown, it is the field curvature and distortion graph. The abscissa is the field curvature bending value and the distortion percentage, and the ordinate is the image height. Among them, it can be seen that the sagittal and meridional maximum field curvatures < 0.04, and the absolute value of the maximum distortion < 1.2%. As Figure 15 shown, it is the lateral chromatic aberration graph, and the lateral chromatic aberration of all wavelengths is less than 2.2 μm. It can be seen that this high-resolution projection lens has good imaging quality and high resolution.

[0117] Embodiment 2:

[0118] As Figures 6 - 10 shown, in this embodiment, a protective glass G4 is further provided between the DMD chip and the prism G3 to protect the DMD chip, and the working distance WD = 1136 mm, F = 2.2, TR = 1.389, TTL / H = 11.

[0119] The parameters such as the surface type, radius of curvature, thickness, and material of each lens are shown in the data in Table 2:

[0120] Table 2

[0121]

[0122]

[0123] According to the above parameters, as Figure 7 shown, it is the MTF graph of each field image plane of a high-resolution projection lens at a working distance WD = 1136 mm. The abscissa is the spatial frequency, and the ordinate is the OTF modulus value. The full field @110 lp / mm > 0.7, and the curve is close to the diffraction limit, indicating that the imaging quality of the lens is clear. As Figure 8 shown, it is the spot diagram, and the size of the RMS points in the full field is less than 0.35 pixel. As Figure 9 shown, it is the field curvature and distortion graph. The abscissa is the field curvature bending value and the distortion percentage, and the ordinate is the image height. Among them, it can be seen that the sagittal and meridional maximum field curvatures < 0.03, and the absolute value of the maximum distortion < 1.0%. As Figure 10 shown, it is the lateral chromatic aberration graph, and the lateral chromatic aberration of all wavelengths is less than 2.0 μm. It can be seen that this high-resolution projection lens has good imaging quality and high resolution.

[0124] Embodiment 3:

[0125] As shown in Figures 11 - 15 In this embodiment, a protective glass G4 is further provided between the DMD chip and the prism G3 in the high-resolution projection lens to protect the DMD chip, and the working distance WD = 1136 mm, F = 2.2, TR = 1.389, TTL / H = 12.18.

[0126] The parameters such as the surface type, radius of curvature, thickness, and material of each lens are shown in the data in Table 3:

[0127] Table 3

[0128]

[0129]

[0130] According to the above parameters, as shown in Figure 12 is the MTF graph of each field image plane of the high-resolution projection lens when the working distance WD = 1136 mm. The abscissa is the spatial frequency, and the ordinate is the OTF modulus value. The full field @110 lp / mm > 0.6, and the curve is close to the diffraction limit, indicating that the imaging quality of the lens is clear. As shown in Figure 13 is the spot diagram, and the size of the RMS points in the full field is less than 0.4 pixel. As shown in Figure 14 is the field curvature and distortion graph. The abscissa is the field curvature bending value and the distortion percentage, and the ordinate is the image height. It can be seen that the sagittal and meridional maximum field curvatures < 0.04, and the absolute value of the maximum distortion < 1.2%. As shown in Figure 15 is the lateral chromatic aberration graph, and the lateral chromatic aberration of all wavelengths is less than 2.3 μm. It can be seen that the high-resolution projection lens has good imaging quality and high resolution.

[0131] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0132] The above-described embodiments only represent the embodiments of the present application that are described in more specific and detailed ways, but should not be construed as limiting the scope of the application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A high-resolution projection lens, characterized in that: The high-resolution projection lens comprises a first lens group (G1), an aperture stop (STO), a second lens group (G2), a prism (G3) and a DMD chip which are sequentially arranged along the optical axis from the magnification side to the reduction side, wherein: The first lens group (G1) and the second lens group (G2) both have positive refractive power and include at least one lens, each of which is a spherical lens and satisfies the following conditions: 5.3 <fa / f00<5.6;2.1<fb / f00<2.4; Wherein, fa is the focal length of the first lens group (G1), fb is the focal length of the second lens group (G2), and f00 is the effective focal length of the high-resolution projection lens, all in units of mm.

2. The high-resolution projection lens according to claim 1, wherein: The first lens group (G1) comprises a first lens (1) with positive focal power, a second lens (2) with negative focal power, a third lens (3) with negative focal power, a fourth lens (4) with positive focal power and a fifth lens (5) with positive focal power, which are sequentially arranged from the magnification side to the reduction side along the optical axis; the second lens group (G2) comprises a sixth lens (6) with positive focal power, a seventh lens (7) with negative focal power, an eighth lens (8) with positive focal power, a ninth lens (9) with negative focal power, a tenth lens (10) with positive focal power and an eleventh lens (11) with positive focal power, which are sequentially arranged from the magnification side to the reduction side along the optical axis; the ninth lens (9) and the tenth lens (10) form a cemented lens with negative focal power.

3. The high-resolution projection lens according to claim 2, wherein: The high-resolution projection lens also meets the following conditions: 4.5 <f1 / f00<4.8;-2.4<f2 / f00<-2.1;-1.1<f3 / f00<-0.8; 2.2 <f4 / f00<2.5;2.8<f5 / f00<3.1;2.2<f6 / f00<2.5; -2.0 <f7 / f00<-1.7;2.1<f8 / f00<2.4;-1<f9 / f00<-0.7; 1.5 <f10 / f00<1.8;1.8<f11 / f00<2.1; Among them, f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, and f11 correspond to the focal lengths of the first lens (1) to the eleventh lens (11) respectively, and the unit is mm.

4. The high-resolution projection lens according to claim 2, wherein: The magnifying side surface of the first lens (1) is concave, and the reducing side surface is convex; the magnifying side surface of the second lens (2) is concave, and the reducing side surface is concave; the magnifying side surface of the third lens (3) is convex, and the reducing side surface is concave; the magnifying side surface of the fourth lens (4) is convex, and the reducing side surface is convex; the magnifying side surface of the fifth lens (5) is convex, and the reducing side surface is convex; the magnifying side surface of the sixth lens (6) is concave, and the reducing side surface is convex; the magnifying side surface of the seventh lens (7) is concave, and the reducing side surface is concave; the magnifying side surface of the eighth lens (8) is concave, and the reducing side surface is convex; the magnifying side surface of the ninth lens (9) is convex, and the reducing side surface is concave; the magnifying side surface of the tenth lens (10) is concave, and the reducing side surface is convex; the magnifying side surface of the eleventh lens (11) is concave, and the reducing side surface is convex.

5. The high-resolution projection lens according to claim 4, wherein: The high-resolution projection lens also meets the following conditions: 40 <R11<60;-140<R12<-120;20<R21<40;1<R22<20; -30 <R31<-10;15<R32<35;-55<R41<-34;-10<R42<-30; -200 <R51<-50;-10<R52<-40;10<R61<30;-80<R62<-60; 50 <R71<80;10<R72<30;20<R81<50;-50<R82<-20; -30 <R91<-10;10<R92<30;10<R101<30;-40<R102<-10; 40 <R111<70;-50<R112<-30; Wherein, R11, R21, R31, R41, R51, R61, R71, R81, R91, R101, and R111 correspond to the curvature radii of the magnification side surfaces of the first lens (1) to the eleventh lens (11), respectively, and R12, R22, R32, R42, R52, R62, R72, R82, R92, R102, and R112 correspond to the curvature radii of the reduction side surfaces of the first lens (1) to the eleventh lens (11), respectively, and the unit is mm.

6. The high-resolution projection lens according to claim 2, wherein: The high-resolution projection lens also meets the following conditions: 1.5 <T1<4.0;1.0<T2<3.5;0.85<T3<1.5;2.5<T4<4.0; 4.0 <T5<5.5;4.0<T6<5.5;0.9<T7<2.0;2.0<T8<4.0; 0.8 <T9<3.0;3.0<T10<5.0;2.5<T11<4.5;0.09<t01<0.2; 4.7 <t02<5.5;1.5<t03<3;9.5<t04<17;15<t05<26.5; 0.1 <t06<0.75;1.0<t07<1.5;0.5<t08<1.5;0.1<t09<2.5; wherein T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, and T11 correspond to the thicknesses of the first lens (1) to the eleventh lens (11), in turn, and are expressed in mm; t01 is the air gap between the first lens (1) and the second lens (2); t02 is the air gap between the second lens (2) and the third lens (3); t03 is the air gap between the third lens (3) and the fourth lens (4); t04 is the air gap between the fourth lens (4) and the fifth lens (5); t05 is the air gap between the fifth lens (5) and the sixth lens (6); t06 is the air gap between the sixth lens (6) and the seventh lens (7); t07 is the air gap between the seventh lens (7) and the eighth lens (8); t08 is the air gap between the eighth lens (8) and the ninth lens (9); and t09 is the air gap between the tenth lens (10) and the eleventh lens (11).

7. The high-resolution projection lens according to claim 2, wherein: The first lens group (1) (G1) further comprises a vignetting stop (AV), wherein the vignetting stop (AV) is located between the fourth lens (4) and the fifth lens (5), or the vignetting stop (AV) is located between the aperture stop (STO) and the sixth lens (6).

8. The high-resolution projection lens according to claim 1, wherein: The high-resolution projection lens also meets the following conditions: 11 <TTL / H<12.2;0.25<BFL / TTL<0.277 Wherein, TTL is the total length of the high-resolution projection lens, H is the image height of the imaging surface of the reduction side of the high-resolution projection lens, and BFL is the back focus of the high-resolution projection lens.

9. The high-resolution projection lens according to claim 1, wherein: Each of the lenses is a glass spherical lens and meets the following conditions: 1.48 <Nd<2.0,17<Vd<80; Where Nd is the refractive index and Vd is the Abbe number; The size of the DMD chip is 8.707 mm×4.918 mm, the pixel size is 0.0045 mm, and the transmittance of all the lenses as a whole is greater than 85% at a wavelength of 450 nm and greater than 90% at a wavelength of 650 nm.

10. The high-resolution projection lens according to claim 1, wherein: The high-resolution projection lens adopts an image-side telecentric optical path and meets the following conditions: 1.2 <TR=(2*f00) / H<1.5;WD=20inch~50inch; F=f00 / D=2.2; CRA<1.0°; Among them, TR is the projection ratio, H is the image height of the imaging surface on the reduction side of the high-resolution projection lens, WD is the working distance of the high-resolution projection lens, F is the F number of the high-resolution projection lens, D is the relative aperture, and CRA is the telecentricity.

Images