A high-resolution projection lens

Abstract

The application discloses a high-resolution projection lens, comprising a first lens group, an aperture diaphragm, a second lens group, a prism and a DMD chip which are sequentially arranged along the optical axis direction from the magnification side to the reduction side, wherein the first lens group and the second lens group both have positive focal lengths and comprise at least one lens, each lens is a spherical lens, and the following conditions are met: 5.3 < fa / f00 < 5.6; 2.1 < fb / f00 < 2.4; 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 units are all mm. The projection lens has high resolution, good imaging quality, is convenient to process and assemble, and is low in cost.

Description

Technical Field

[0001] This invention belongs to the field of projection lens technology, and specifically relates to a high-resolution projection lens. Background Technology

[0002] With the rapid development of semiconductor technology and the continuous advancement of projection display technology, projection equipment has been gradually applied to home, business, education and industrial inspection fields. 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 high resolution requirements of projection lenses, a larger F-number can reduce aberrations and improve edge image uniformity. However, the design of large-aperture projection lenses is inherently complex and costly. Furthermore, the complex optical path design of projection lenses, such as the combination of prisms and reflectors at the rear, makes it difficult to reduce the size of projection lenses. In order to match the projection lens with the prism, a longer back working distance needs to be maintained, which increases the design difficulty.

[0004] In addition, existing projection lens technologies offer other ways to improve projection quality. For example, using aspherical and freeform surface technologies in optical design can reduce the design complexity of the optical system and simplify its structure. However, aspherical and freeform surface technologies are costly to manufacture and difficult to assemble, increasing costs and reducing production efficiency. Furthermore, technologies such as DLP, LCoS, and XPR are used in the optical engine system to achieve high resolution in projection lenses. Among these, XPR technology strikes a better balance between cost and performance compared to other technologies and is compatible with high frame rates, promoting the widespread adoption of 4K projection. However, XPR technology places certain requirements on the projection lens's median resolution (MTF). For instance, in the mid-frequency range (50~150 lp / mm), the MTF needs to be greater than 0.6 to ensure image edge sharpness and texture detail, while in the high-frequency range (185 lp / mm), the MTF needs to be greater than 0.3 to resolve the sub-pixel shift signal generated by XPR. Consistency across the entire field of view is also crucial, and strict requirements are placed on chromatic aberration and other aberrations. Therefore, to address the problem that existing technologies struggle to balance aberrations, F-number, distortion, and cost in projection lenses, a high-resolution projection lens is proposed. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by proposing a high-resolution projection lens that has high resolution, good image quality, is easy to manufacture and assemble, and has low cost.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The present invention proposes a high-resolution projection lens, comprising a first lens group, an aperture stop, a second lens group, a prism, and a DMD chip arranged sequentially along the optical axis from the magnification side to the reduction side, wherein:

[0008] Both the first and second lens groups have positive optical power and include at least one lens, each of which is a spherical lens, and satisfy the following conditions:

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

[0010] Where 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, all in 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, arranged sequentially along the optical axis 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, arranged sequentially along the optical axis from the magnifying side to the reducing side, wherein the ninth lens and the tenth lens constitute a cemented lens with negative optical power.

[0012] Preferably, the high-resolution projection lens also meets 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] Where f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, and f11 correspond to the focal lengths of the first to eleventh lenses, respectively, in mm.

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

[0019] If the surface shape of other surfaces remains unchanged, the reducing side surface of the first lens is flat, and the magnifying side surface of the fifth lens is convex.

[0020] Preferably, the high-resolution projection lens also meets the following conditions:

[0021] 40 <R11<60;-140 <R12<-120;20<R21<40;1<R22<20;

[0022] -30 <R31<-10;15< R32 < 35;-55<R41<-34;-10<R42<-30;

[0023] -200 < R51 < -50; -10 <R52<-40;10<R61<30;-80<R62<-60;

[0024] 50 <R71<80;10<R72<30;20<R81<50;-50<R82<-20;

[0025] -30 <R91<-10;10<R92<30;10<R101<30;-40<R102<-10;

[0026] 40 <R111<70;-50<R112<-30;

[0027] Wherein, R11, R21, R31, R41, R51, R61, R71, R81, R91, R101, and R111 correspond to the radii of curvature of the magnifying side surfaces of the first to eleventh lenses, respectively, and R12, R22, R32, R42, R52, R62, R72, R82, R92, R102, and R112 correspond to the radii of curvature of the reducing side surfaces of the first to eleventh lenses, respectively, in mm.

[0028] Preferably, the high-resolution projection lens also meets the following conditions:

[0029] 1.5 <T1<4.0;1.0<T2<3.5;0.85<T3<1.5;2.5<T4<4.0;

[0030] 4.0 <T5<5.5;4.0<T6<5.5;0.9<T7 < 2.0;2.0<T8<4.0;

[0031] 0.8 <T9<3.0;3.0<T10<5.0;2.5<T11<4.5;0.09<t01 <0.2;

[0032] 4.7 <t02 <5.5;1.5< t03 <3;9.5< t04 <17;15< t05 <26.5;

[0033] 0.1< t06 <0.75; 1.0< t07 <1.5; 0.5< t08 <1.5; 0.1< t09 <2.5;

[0034] Wherein, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, and T11 correspond to the thicknesses of the first to eleventh lenses, in mm, respectively. t01 is the air gap between the first and second lenses, t02 is the air gap between the second and third lenses, t03 is the air gap between the third and fourth lenses, t04 is the air gap between the fourth and fifth lenses, t05 is the air gap between the fifth and sixth lenses, t06 is the air gap between the sixth and seventh lenses, t07 is the air gap between the seventh and eighth lenses, t08 is the air gap between the eighth and ninth lenses, and t09 is the air gap between the tenth and eleventh lenses.

[0035] Preferably, the first lens group further includes a vignetting stop, which is located between the fourth lens and the fifth lens, or between the aperture stop and the sixth lens.

[0036] Preferably, the high-resolution projection lens also meets the following conditions:

[0037] 11 <TTL / H<12.2;0.25<BFL / TTL<0.277

[0038] Where TTL is the total length of the high-resolution projection lens, H is the image height of the image plane on the reduced side of the high-resolution projection lens, and BFL is the back focal length of the high-resolution projection lens.

[0039] Preferably, each lens is a glass spherical lens, and satisfies the following conditions:

[0040] 1.48 <Nd<2.0,17<Vd<80;

[0041] Where Nd is the refractive index and Vd is the Abbe number;

[0042] The DMD chip measures 8.707mm × 4.918mm, with a pixel size of 0.0045mm. The overall transmittance of all lenses is greater than 85% at a wavelength of 450nm and greater than 90% at a wavelength of 650nm.

[0043] Preferably, the high-resolution projection lens adopts an image-side telecentric optical path and meets the following conditions:

[0044] 1.2 <TR=(2 f00) / H <1.5; WD=20inch~50inch;

[0045] F=f00 / D=2.2; CRA<1.0°;

[0046] Where TR is the projection ratio, H is the image height of the image plane on the reduced 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.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] This high-resolution projection lens includes a first lens group, an aperture stop, a second lens group, a prism, and a DMD chip, arranged sequentially along the optical axis 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 and tenth lenses are cemented lenses, which are beneficial for correcting the second-order spectrum. Furthermore, all lenses are glass spherical lenses, which are inexpensive, have high thermal stability, and are easy to manufacture. Assembly is simple; and by reasonably setting the parameters of each lens, the relative illumination across the entire field of view is higher than 0.7, and in particular, the relative illumination at the 0.8 field of view is higher than 0.85. The optical distortion can be kept within 1.5%, and the transverse chromatic aberration and dot plot are both less than 0.5 pixels across the entire field of view, resulting in good image quality. Based on a resolution of 111 lp / mm and MTF>0.6, it is compatible with XPR technology to achieve high-definition images, high-brightness images, and rich color projection display, achieving low cost, low distortion, and 1080P high-resolution projection effect, thus improving the user experience. Attached Figure Description

[0049] Figure 1 This is an optical structure diagram of the high-resolution projection lens in Embodiment 1 of the present invention;

[0050] Figure 2The MTF plots of the high-resolution projection lens in Embodiment 1 of the present invention are shown below.

[0051] Figure 3 This is a dot plot of the high-resolution projection lens in Embodiment 1 of the present invention;

[0052] Figure 4 This is a field curvature distortion diagram of the high-resolution projection lens in Embodiment 1 of the present invention;

[0053] Figure 5 This is a transverse chromatic aberration diagram of the high-resolution projection lens in Embodiment 1 of the present invention;

[0054] Figure 6 This is an optical structure diagram of the high-resolution projection lens in Embodiment 2 of the present invention;

[0055] Figure 7 The MTF plots of the high-resolution projection lens in Embodiment 2 of the present invention are shown below.

[0056] Figure 8 This is a dot plot of the high-resolution projection lens in Embodiment 2 of the present invention;

[0057] Figure 9 This is a field curvature distortion diagram of the high-resolution projection lens in Embodiment 2 of the present invention;

[0058] Figure 10 This is a transverse chromatic aberration diagram of the high-resolution projection lens in Embodiment 2 of the present invention;

[0059] Figure 11 This is an optical structure diagram of the high-resolution projection lens in Embodiment 3 of the present invention;

[0060] Figure 12 The MTF plots of the high-resolution projection lens in Embodiment 3 of the present invention are shown below.

[0061] Figure 13 This is a dot plot of the high-resolution projection lens in Embodiment 3 of the present invention;

[0062] Figure 14 This is a field curvature distortion diagram of the high-resolution projection lens in Embodiment 3 of the present invention;

[0063] Figure 15 This is a chromatic aberration diagram of the high-resolution projection lens in Embodiment 3 of the present invention.

[0064] Explanation of reference numerals in the attached diagram: G1, first lens group; STO, aperture stop; G2, second lens group; G3, prism; G4, protective glass; 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; AV, vignetting stop; 5, fifth lens; 6, sixth lens; 7, seventh lens; 8, eighth lens; 9, ninth lens; 10, tenth lens; 11, eleventh lens. Detailed Implementation

[0065] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0066] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application.

[0067] like Figures 1-15 As 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 arranged sequentially along the optical axis from the magnification side to the reduction side, wherein:

[0068] Both the first lens group G1 and the second lens group G2 have positive optical power and include at least one lens. Each lens is a spherical lens and satisfies the following conditions:

[0069] 5.3 < fa / f00 < 5.6; 2.1 <fb / f00 <2.4;

[0070] Where 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 mm.

[0071] 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, arranged sequentially along the optical axis from the magnification side to the reduction side. A protective glass G4 can be placed between the prism G3 and the DMD chip to protect the DMD chip. All lenses are glass spherical lenses, which are inexpensive, have high thermal stability, are easy to manufacture, and are simple to assemble.

[0072] In one embodiment, the first lens group G1 includes a first lens 1 with positive optical power, a second lens 2 with negative optical power, a third lens 3 with negative optical power, a fourth lens 4 with positive optical power, and a fifth lens 5 with positive optical power, arranged sequentially along the optical axis from the magnification side to the reduction side; the second lens group G2 includes a sixth lens 6 with positive optical power, a seventh lens 7 with negative optical power, an eighth lens 8 with positive optical power, a ninth lens 9 with negative optical power, a tenth lens 10 with positive optical power, and an eleventh lens 11 with positive optical power, arranged sequentially along the optical axis from the magnification side to the reduction side, wherein the ninth lens 9 and the tenth lens 10 constitute a cemented lens with negative optical power.

[0073] In this embodiment, the first lens group includes five coaxially arranged spherical lenses, and the second lens group includes six coaxially arranged spherical lenses.

[0074] In one embodiment, the high-resolution projection lens also satisfies the following condition:

[0075] 4.5< f1 / f00 <4.8; -2.4< f2 / f00 <-2.1; -1.1< f3 / f00 <-0.8;

[0076] 2.2< f4 / f00 <2.5; 2.8< f5 / f00 <3.1; 2.2< f6 / f00 <2.5;

[0077] -2.0< f7 / f00 <-1.7; 2.1< f8 / f00 <2.4; -1< f9 / f00 <-0.7;

[0078] 1.5< f10 / f00 <1.8; 1.8< f11 / f00 <2.1;

[0079] 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, in mm.

[0080] In one embodiment, the magnifying side surface of the first lens 1 is convex, and the reducing side surface is convex; the magnifying side surface of the second lens 2 is convex, and the reducing side surface is concave; the magnifying side surface of the third lens 3 is concave, and the reducing side surface is concave; the magnifying side surface of the fourth lens 4 is concave, and the reducing side surface is convex; the magnifying side surface of the fifth lens 5 is concave, and the reducing side surface is convex; the magnifying side surface of the sixth lens 6 is convex, and the reducing side surface is convex; the magnifying side surface of the seventh lens 7 is convex, and the reducing side surface is concave; the magnifying side surface of the eighth lens 8 is convex, and the reducing side surface is convex; the magnifying side surface of the ninth lens 9 is concave, and the reducing side surface is concave; the magnifying side surface of the tenth lens 10 is convex, and the reducing side surface is convex; and the magnifying side surface of the eleventh lens 11 is convex, and the reducing side surface is convex.

[0081] If the surface shape of other surfaces remains unchanged, the reducing side surface of the first lens 1 is a plane, and the magnifying side surface of the fifth lens 5 is a convex surface.

[0082] Among them, the first lens 1 is a biconvex positive lens, which can effectively reduce beam height and decrease field aberration; the fourth lens 4 is a meniscus lens, which can minimize spherical aberration. The ninth lens 9 and the tenth lens 10 form a cemented lens, which can correct the second-order spectrum.

[0083] In one embodiment, the high-resolution projection lens also satisfies the following condition:

[0084] 40 <R11<60;-140 <R12<-120;20<R21<40;1<R22<20;

[0085] -30 <R31<-10;15< R32 < 35;-55<R41<-34;-10<R42<-30;

[0086] -200 < R51 < -50; -10 <R52<-40;10<R61<30;-80<R62<-60;

[0087] 50 <R71<80;10<R72<30;20<R81<50;-50<R82<-20;

[0088] -30 <R91<-10;10<R92<30;10<R101<30;-40<R102<-10;

[0089] 40 <R111<70;-50<R112<-30;

[0090] Wherein, R11, R21, R31, R41, R51, R61, R71, R81, R91, R101, and R111 correspond to the curvature radii of the magnifying 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 reducing side surfaces of the first lens 1 to the eleventh lens 11, respectively, in mm.

[0091] In one embodiment, the high-resolution projection lens also satisfies the following condition:

[0092] 1.5 <T1<4.0;1.0<T2<3.5;0.85<T3<1.5;2.5<T4<4.0;

[0093] 4.0 <T5<5.5;4.0<T6<5.5;0.9<T7 < 2.0;2.0<T8<4.0;

[0094] 0.8 <T9<3.0;3.0<T10<5.0;2.5<T11<4.5;0.09<t01 <0.2;

[0095] 4.7 <t02 <5.5;1.5< t03 <3;9.5< t04 <17;15< t05 <26.5;

[0096] 0.1< t06 <0.75; 1.0< t07 <1.5; 0.5< t08 <1.5; 0.1< t09 <2.5;

[0097] 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 mm, respectively. 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.

[0098] In one embodiment, the first lens group G1 further includes a vignetting stop AV, which is located between the fourth lens 4 and the fifth lens 5, or between the aperture stop STO and the sixth lens 6. The vignetting stop AV can reduce the aperture of the lens facing the magnifying side (i.e., each lens in the first lens group G1) and adjust the telecentricity CRA of the high-resolution projection lens to <1.0°.

[0099] In one embodiment, the high-resolution projection lens also satisfies the following condition:

[0100] 11 <TTL / H<12.2;0.25<BFL / TTL<0.277

[0101] Where TTL is the total length of the high-resolution projection lens, H is the image height of the image plane on the reduced side of the high-resolution projection lens, and BFL is the back focal length of the high-resolution projection lens.

[0102] In one embodiment, each lens is a glass spherical lens, and satisfies the following condition:

[0103] 1.48 <Nd<2.0,17<Vd<80;

[0104] Where Nd is the refractive index and Vd is the Abbe number;

[0105] The DMD chip measures 8.707mm × 4.918mm, with a pixel size of 0.0045mm. The overall transmittance of all lenses is greater than 85% at a wavelength of 450nm and greater than 90% at a wavelength of 650nm.

[0106] In one embodiment, the high-resolution projection lens employs an image-side telecentric optical path and satisfies the following conditions:

[0107] 1.2 <TR=(2 f00) / H <1.5; WD=20inch~50inch;

[0108] F=f00 / D=2.2; CRA<1.0°;

[0109] Where TR is the projection ratio, H is the image height of the image plane on the reduced 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.

[0110] This high-resolution projection lens consists of eleven glass lenses. The first lens 1, located on the magnification side, is a positive lens, lowering the light beam height and thus reducing the aperture at the front of the lens, thereby reducing its overall size. The third lens 3 shares the optical power of the second lens 2, providing a deflection angle for edge rays, reducing field aberrations, and improving the lens's resolution. The vignetting stop AV, positioned between the fourth lens 4 and the fifth lens 5, can block large incident angle beams, reducing edge field aberrations. Furthermore, the vignetting stop AV, located before the aperture stop STO and close to the magnification side, improves system performance (aberrations, field curvature, and resolution) while its smaller aperture reduces the system's telecentricity. The sixth lens 7 is a biconvex lens, effectively lowering the light beam height emitted from the aperture stop STO, reducing aperture aberrations. Its low refractive index and high Abbe number material effectively compensates for image blurring under high and low temperatures. The seventh lens 7 is a negative lens, forming a positive-negative pair with the sixth lens 6, effectively improving the projection... The projection performance of the projection system is as follows: The eighth lens 8 is a biconvex lens, which can effectively smooth the light path, reduce system sensitivity, improve system yield, and reduce cost. It is also made of a similar material to the sixth lens 6, which is a low-refractive-index, high-Abbe number material, which further compensates for back focus shift caused by high and low temperatures. The ninth lens 9 and the tenth lens 10 form a cemented doublet lens group, which can effectively correct chromatic aberration, spherical aberration, and coma of the projection system, thereby improving system performance. The eleventh lens 11 is used as the field lens in the projection system and is placed at the shrink end of the projection system, close to the prism G3, to compensate for field curvature and distortion in the system, which helps to improve resolution.

[0111] For ease of understanding, the following detailed explanation is provided through specific embodiments.

[0112] Example 1:

[0113] like Figure 1-5 As shown, in this embodiment, the high-resolution projection lens is further provided with a protective glass G4 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.

[0114] The surface type, radius of curvature, thickness, material, and other parameters of each lens are shown in Table 1.

[0115] Table 1

[0116]

[0117] Based on the above parameters, such as Figure 2As shown, the optical transfer function (MTF) plots of the high-resolution projection lens on each field of view are displayed at a working distance WD=1190mm. The horizontal axis represents spatial frequency, and the vertical axis represents the OTF modulus. The full field of view @110lp / mm > 0.6, and the curve is close to the diffraction limit, indicating clear image quality from the lens. Figure 3 As shown, this is a point plot, where the size of all RMS points across the entire field of view is less than 0.5 pixels. Figure 4 As shown, this is a field curvature distortion diagram. The horizontal axis represents the field curvature value and distortion percentage, and the vertical axis represents the image height. It can be seen that the maximum field curvature for both sagittal and meridional fields is <0.04, and the absolute value of the maximum distortion is <1.2%. Figure 15 As shown, the transverse chromatic aberration diagram shows that the transverse chromatic aberration for all wavelengths is less than 2.2µm. This indicates that the high-resolution projection lens possesses excellent image quality and high resolution.

[0118] Example 2:

[0119] like Figure 6-10 As shown, in this embodiment, the high-resolution projection lens is further provided with a protective glass G4 between the DMD chip and the prism G3 to protect the DMD chip, and the working distance WD=1136mm, F=2.2, TR=1.389, TTL / H=11.

[0120] The surface type, radius of curvature, thickness, material, and other parameters of each lens are shown in Table 2.

[0121] Table 2

[0122]

[0123] Based on the above parameters, such as Figure 7 As shown, the optical transfer function (MTF) plots of the high-resolution projection lens on each field of view are displayed at a working distance WD=1136mm. The horizontal axis represents spatial frequency, and the vertical axis represents the OTF modulus. The full field of view @110lp / mm > 0.7, and the curve is close to the diffraction limit, indicating clear image quality from the lens. Figure 8 As shown, this is a point plot, where the size of all RMS points across the entire field of view is less than 0.35 pixels. Figure 9 The image shown is a field curvature distortion diagram. The horizontal axis represents the field curvature value and distortion percentage, and the vertical axis represents the image height. It can be seen that the maximum field curvature for both sagittal and meridional fields is <0.03, and the absolute value of the maximum distortion is <1.0%. Figure 10 As shown, the transverse chromatic aberration diagram shows that the transverse chromatic aberration for all wavelengths is less than 2.0µm. This indicates that the high-resolution projection lens possesses excellent image quality and high resolution.

[0124] Example 3:

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

[0126] The surface type, radius of curvature, thickness, material, and other parameters of each lens are shown in Table 3.

[0127] Table 3

[0128]

[0129] Based on the above parameters, such as Figure 12 As shown, the optical transfer function (MTF) plots of the high-resolution projection lens on each field of view are displayed at a working distance WD=1136mm. The horizontal axis represents spatial frequency, and the vertical axis represents the OTF modulus. The full field of view @110lp / mm > 0.6, and the curve is close to the diffraction limit, indicating clear image quality from the lens. Figure 13 As shown, this is a point plot, where the size of all RMS points across the entire field of view is less than 0.4 pixels. Figure 14 As shown, this is a field curvature distortion diagram. The horizontal axis represents the field curvature value and distortion percentage, and the vertical axis represents the image height. It can be seen that the maximum field curvature for both sagittal and meridional fields is <0.04, and the absolute value of the maximum distortion is <1.2%. Figure 15 As shown, the transverse chromatic aberration diagram shows that the transverse chromatic aberration for all wavelengths is less than 2.3µm. This indicates that the high-resolution projection lens possesses excellent image quality and high resolution.

[0130] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0131] The embodiments described above are merely specific and detailed examples of the embodiments described in this application, and should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A high-resolution projection lens, characterized in that: The 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, arranged sequentially along the optical axis from the magnification side to the reduction side. The high-resolution projection lens has eleven lenses with optical power, wherein: The first lens group (G1) and the second lens group (G2) both have positive optical power and include at least one lens. Each of the lenses is a spherical lens and satisfies the following conditions: 5.3 < fa / f00 < 5.6; 2.1 <fb / f00 <2.4; Where 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 mm. The first lens group (G1) includes a first lens (1) with positive optical power, a second lens (2) with negative optical power, a third lens (3) with negative optical power, a fourth lens (4) with positive optical power, and a fifth lens (5) with positive optical power, arranged sequentially along the optical axis from the magnification side to the reduction side; the second lens group (G2) includes a sixth lens (6) with positive optical power, a seventh lens (7) with negative optical power, an eighth lens (8) with positive optical power, a ninth lens (9) with negative optical power, a tenth lens (10) with positive optical power, and an eleventh lens (11) with positive optical power, arranged sequentially along the optical axis from the magnification side to the reduction side, wherein the ninth lens (9) and the tenth lens (10) form a cemented lens with negative optical power. The magnifying side surface of the first lens (1) is convex, and the reducing side surface is convex; the magnifying side surface of the second lens (2) is convex, and the reducing side surface is concave; the magnifying side surface of the third lens (3) is concave, and the reducing side surface is concave; the magnifying side surface of the fourth lens (4) is concave, and the reducing side surface is convex; the magnifying side surface of the fifth lens (5) is concave, and the reducing side surface is convex; the magnifying side surface of the sixth lens (6) is convex, and the reducing side surface is convex; the magnifying side surface of the seventh lens (7) is convex, and the reducing side surface is concave; the magnifying side surface of the eighth lens (8) is convex, and the reducing side surface is convex; the magnifying side surface of the ninth lens (9) is concave, and the reducing side surface is concave; the magnifying side surface of the tenth lens (10) is convex, and the reducing side surface is convex; the magnifying side surface of the eleventh lens (11) is convex, and the reducing side surface is convex. If the surface shape of other surfaces remains unchanged, the shrinking side surface of the first lens (1) is a plane, and the magnifying side surface of the fifth lens (5) is a convex surface.

2. The high-resolution projection lens as described in claim 1, characterized in that: 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; Wherein, 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) in mm.

3. The high-resolution projection lens as described in claim 1, characterized in that: 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; Among them, R11, R21, R31, R41, R51, R61, R71, R81, R91, R101, and R111 correspond to the curvature radii of the magnifying side surfaces of the first lens (1) to the eleventh lens (11) in sequence, and R12, R22, R32, R42, R52, R62, R72, R82, R92, R102, and R112 correspond to the curvature radii of the reducing side surfaces of the first lens (1) to the eleventh lens (11) in sequence, in mm.

4. The high-resolution projection lens as described in claim 1, characterized in that: 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 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).

5. The high-resolution projection lens as described in claim 1, characterized in that: The first lens group (1) (G1) further includes a vignetting stop (AV), which is located between the fourth lens (4) and the fifth lens (5), or between the aperture stop (STO) and the sixth lens (6).

6. The high-resolution projection lens as described in claim 1, characterized in that: 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 image plane on the reduced side of the high-resolution projection lens, and BFL is the back focal length of the high-resolution projection lens.

7. The high-resolution projection lens as described in claim 1, characterized in that: All of the lenses are glass spherical lenses and satisfy the following conditions: 1.48 <Nd<2.0,17<Vd<80; Where Nd is the refractive index and Vd is the Abbe number; The DMD chip has a size of 8.707mm × 4.918mm and a pixel size of 0.0045mm. The overall transmittance of all the lenses is greater than 85% at a wavelength of 450nm and greater than 90% at a wavelength of 650nm.

8. The high-resolution projection lens as described in claim 1, characterized in that: 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°; Where TR is the projection ratio, H is the image height of the image plane on the reduced 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.

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