Miniaturized large target surface projection lens

Abstract

The application relates to a miniaturized large-target-surface projection lens, which comprises, in sequence along the direction of an optical axis, a first lens with positive focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with positive focal power, a fifth lens with negative focal power, a sixth lens with positive focal power, a seventh lens with positive focal power, an eighth lens with positive focal power, a ninth lens with negative focal power, a tenth lens with positive focal power, an eleventh lens with negative focal power, a twelfth lens with positive focal power and a thirteenth lens with positive focal power; and the miniaturized large-target-surface projection lens is also provided with reasonable focal lengths and total lengths, so that the lens has small volume, high resolution, large image surface, and can meet the severe use requirements under the environment of-40 DEG C to 85 DEG C, and has high yield in mass production.

Description

Technical Field

[0001] This invention belongs to the field of optical lens technology, specifically relating to a miniaturized large-target projection lens. Background Technology

[0002] With the booming development of the new energy vehicle industry, the demand for in-vehicle entertainment systems is becoming increasingly diversified. Among them, projection equipment has attracted much attention due to its ability to provide a large-screen viewing experience within limited spaces. However, in the pursuit of miniaturization and large-area projection, existing technologies face a series of challenges. Traditional projectors, due to their large size, are difficult to adapt to the compact space layout inside vehicles, which has become a major obstacle to their application in the automotive field. In addition, under complex operating environments such as high temperature, low temperature, and vibration, the performance of traditional projectors is often significantly reduced, and the improvement of resolution also encounters bottlenecks. These factors together limit the effective application of traditional projectors in automotive spaces.

[0003] To overcome size limitations, a number of smaller projectors have emerged on the market. These mini projectors generally use aspherical lenses, thus meeting the basic requirements of clarity and TV distortion while maintaining a small size. However, the use of plastic aspherical lenses has brought new problems. Plastic lenses are prone to aging and wear, and are difficult to clean after getting dirty. They are also not resistant to high temperatures and high brightness environments. These problems severely shorten the lifespan of the projector and limit its usage conditions. To improve durability and optical performance, some mini projectors have begun to try using glass as the processing material for aspherical lenses. Although glass lenses perform well in terms of durability and optical performance, their processing places strict requirements on the lens thickness ratio and the ratio of aperture to thickness. This means that for the same aperture, the thickness of a glass lens needs to be more than doubled, which undoubtedly increases production costs and manufacturing difficulty. In addition, when the precision requirements for processing glass aspherical curved surfaces are high, the limitations on the lens shape will be further increased, which is not conducive to mass production.

[0004] In summary, miniaturization and large-area projection lenses face numerous challenges under current technology, including the bulky size and limited performance of traditional projectors, the poor durability of plastic lenses in small projectors, and the difficulty and high cost of processing glass lenses. Therefore, developing a projection lens that can meet the requirements of miniaturization, achieve large-area projection, and possess good durability and optical performance is particularly important. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by proposing a miniaturized large target projection lens. This lens has a small size, large target area, and high resolution, while meeting the stringent usage requirements in environments ranging from -40℃ to 85℃, and achieving a high yield in mass production.

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

[0007] The present invention proposes a miniaturized large target projection lens, comprising 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, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with positive optical power, an eighth lens with positive optical power, a ninth lens with negative optical power, a tenth lens with positive optical power, an eleventh lens with negative optical power, a twelfth lens with positive optical power, and a thirteenth lens with positive optical power, all arranged sequentially along the optical axis. Each lens is a glass spherical lens.

[0008] The miniaturized large target projection lens also includes an aperture stop, which is located between the sixth and seventh lenses, or between the seventh and eighth lenses;

[0009] Furthermore, the miniaturized large-target projection lens also meets the following conditions:

[0010] 13.13≤f≤15.8;54≤OAL≤57

[0011] Where f is the effective focal length of the miniaturized large-target projection lens, in mm; OAL is the on-axis distance from the object side of the first lens to the image side of the thirteenth lens, in mm.

[0012] Preferably, the first lens is a convex-plano lens or a convex-concave lens, the second lens is a convex-concave lens, the third lens is a convex-concave lens, the fourth lens is a biconvex lens or a plano-convex lens, the fifth lens is a biconcave lens, the sixth lens is a plano-convex lens or a convex-plano lens, the seventh lens is a biconvex lens, the eighth lens is a biconvex lens or a concave-convex lens, the ninth lens is a convex-concave lens, the tenth lens is a biconvex lens or a concave-convex lens, the eleventh lens is a biconcave lens, the twelfth lens is a biconvex lens, and the thirteenth lens is a biconvex lens. The miniaturized large-target projection lens also satisfies the following conditions:

[0013] <![CDATA[56.10<f1<68.9]]> <![CDATA[23.37<R 11 <32.52]]> <![CDATA[66.01<R 12 <131.2]]> <![CDATA[-33.36<f2<-25.5]]> <![CDATA[17.05<R 21 <23.89]]> <![CDATA[8.18<R 22 <10.52]]> <![CDATA[-34.76<f3<-27.02]]> <![CDATA[22.02<R 31 <34.78]]> <![CDATA[10.02<R 32 <11.35]]> <![CDATA[24.25<f4<31.35]]> <![CDATA[34.86<R 41 <285.9]]> <![CDATA[-210.59<R 42 <-30.5]]> <![CDATA[-18.66<f5<-17.2]]> <![CDATA[-45.51<R 51 <-20.32]]> <![CDATA[10.12<R 52 <16.8]]> <![CDATA[35.3<f6<91.2]]> <![CDATA[45.52<R 61 <+∞]]> <![CDATA[-220.7<R 62 <-42.27]]> <![CDATA[18.7<f7<21.2]]> <![CDATA[-12.6<R 71 <107.9]]> <![CDATA[-∞<R 72 <-15.17]]> <![CDATA[33.1<f8<99.8]]> <![CDATA[-135.1<R 81 <25.95]]> <![CDATA[-49.7<R 82 <-14.01]]> <![CDATA[-39.5<f9<-19.2]]> <![CDATA[-216.6<R 91 <517.29]]> <![CDATA[19.42<R 92 <22.6]]> <![CDATA[15.05<f 10 <29.95]]> <![CDATA[-166.5<R 101 <187.9]]> <![CDATA[-17.2<R 102 <-9.01]]> <![CDATA[-11.6<f 11 <-8.01]]> <![CDATA[-13.53<R 111 <-8.9]]> <![CDATA[-9.96<R 112 <34.9]]> <![CDATA[19.23<f 12 <21.9]]> <![CDATA[24.28<R 121 <35.78]]> <![CDATA[-22.16<R 122 <-18.37]]> <![CDATA[24.5<f 13 <28.6]]> <![CDATA[42.93<R 131 <56.3]]> <![CDATA[-69.7<R 132 <-41.2]]>

[0014] Among them, f1~f 13 The focal lengths of the first to thirteenth lenses are listed in mm; R 11 R 21 R 31 R 41 R 51 R 61 R 71 R 81 R 91 R 101 R 111 R 121 R131 The following are the radii of curvature of the object-side surfaces of the first to thirteenth lenses, in mm; R 12 R 22 R 32 R 42 R 52 R 62 R 72 R 82 R 92 R 102 R 112 R 122 R 132 The radii of curvature of the image-side surfaces of the first to thirteenth lenses are in mm, respectively; "-" indicates the negative direction.

[0015] Preferably, the miniaturized large-target projection lens also meets the following conditions:

[0016]

[0017] Where D is the entrance pupil diameter, in mm.

[0018] Preferably, the miniaturized large-target projection lens also meets the following conditions:

[0019]

[0020] Wherein, SD1 is the edge ray height of the object side of the first lens, and SD13 is the edge ray height of the image side of the thirteenth lens.

[0021] Preferably, the miniaturized large-target projection lens also meets the following conditions:

[0022] -1% ≤ DIST ≤ -0.5%, RI ≥ 60%

[0023] Wherein, FOV is the full field of view of the maximum field of view, DIST is the maximum optical distortion from the center to the edge of the field of view, and RI is the relative illumination of the miniaturized large target projection lens on the image plane.

[0024] Preferably, the miniaturized large-target projection lens also meets the following conditions:

[0025] 6≤th4+th6+th11+th13≤11

[0026] Where th4 is the median thickness of the fourth lens, th6 is the median thickness of the sixth lens, th11 is the median thickness of the eleventh lens, and th13 is the median thickness of the thirteenth lens, all in mm.

[0027] Preferably, the miniaturized large-target projection lens also meets the following conditions:

[0028] 115≤abv10+abv12≤160

[0029] Where abv10 is the Abbe number of the tenth lens and abv12 is the Abbe number of the twelfth lens.

[0030] Preferably, the miniaturized large-target projection lens also meets the following conditions:

[0031]

[0032] Where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens, in mm.

[0033] Preferably, the miniaturized large-target projection lens also includes a prism, which is located between the thirteenth lens and the image plane.

[0034] Preferably, the miniaturized large-target projection lens also meets the following conditions:

[0035] CRA≤2.0°, 20mm≤FFL≤30mm

[0036] Wherein, CRA is the maximum incident angle of the miniaturized large-target projection lens on the image plane, and FFL is the on-axis distance from the image side of the thirteenth lens to the image plane.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] This lens employs a thirteen-element spherical glass architecture, reducing costs while ensuring image quality. Its compact structure, with a total length under 57mm, is achieved through the rational allocation of optical power, ensuring a small overall size. Furthermore, the skillful distribution of glass lenses corrects various aberrations, improving edge sharpness and thus enhancing image quality. A maximum aperture of F1.95 allows for higher light output, and the optimal use of complementary materials ensures the lens remains in focus within a temperature range of -40℃ to +85℃, resulting in more stable performance. The minimum throw ratio is 1.266, making it compatible with a wide range of optical components. The 0.47” DMD chip with a 105% offset achieves a large target surface of Φ16mm, high pixel count, and good image quality. It can provide sufficient projection brightness and size, and the projected image is clear and sharp, meeting the requirements of 1080P resolution, high contrast, and accurate color reproduction. Compared with the plastic aspherical and glass aspherical surfaces used in traditional projection equipment, the glass spherical surface used in this invention not only ensures the advantages of automotive-grade high temperature and vibration resistance, but also ensures processability. By converting the large assembly tolerance into a smaller bonding tolerance, the assembly processability is improved, which greatly improves the mass production yield of the lens. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the miniaturized large target projection lens of Embodiment 1 of the present invention;

[0040] Figure 2 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the miniaturized large target projection lens of Embodiment 1 of the present invention are shown below.

[0041] Figure 3 This is the MTF diagram of the miniaturized large target projection lens of Embodiment 1 of the present invention;

[0042] Figure 4 This is a schematic diagram of the miniaturized large target projection lens of Embodiment 2 of the present invention;

[0043] Figure 5 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the miniaturized large target projection lens of Embodiment 2 of the present invention are shown below.

[0044] Figure 6 This is the MTF diagram of the miniaturized large target projection lens of Embodiment 2 of the present invention;

[0045] Figure 7 This is a schematic diagram of the miniaturized large target projection lens of Embodiment 3 of the present invention;

[0046] Figure 8 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the miniaturized large target projection lens of Embodiment 3 of the present invention are shown below.

[0047] Figure 9 The MTF diagram of the miniaturized large target projection lens in Embodiment 3 of the present invention;

[0048] Figure 10 This is a schematic diagram of the miniaturized large target projection lens of Embodiment 4 of the present invention;

[0049] Figure 11 The longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the miniaturized large target projection lens of Embodiment 4 of the present invention are shown below.

[0050] Figure 12 This is the MTF diagram of the miniaturized large target projection lens in Embodiment 4 of the present invention.

[0051] Explanation of reference numerals in the attached diagram: L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; L7, seventh lens; L8, eighth lens; L9, ninth lens; L10, tenth lens; L11, eleventh lens; L12, twelfth lens; L13, thirteenth lens; L14, prism; STO, aperture stop; CG, protective glass; IMA, image plane. Detailed Implementation

[0052] 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.

[0053] 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 to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application.

[0054] This application's miniaturized large-area projection lens effectively solves the shortcomings of traditional projectors in terms of size limitations and small projection area in vehicle spaces. Its compact design allows the projection device to better adapt to the limited space inside a vehicle, while the all-glass architecture and large aperture ensure high-quality projection even in harsh in-vehicle environments. This lens not only enhances the performance of in-vehicle entertainment systems but also provides consumers with a more immersive and comfortable viewing experience.

[0055] A miniaturized large-target projection lens includes a first lens L1 with positive optical power, a second lens L2 with negative optical power, a third lens L3 with negative optical power, a fourth lens L4 with positive optical power, a fifth lens L5 with negative optical power, a sixth lens L6 with positive optical power, a seventh lens L7 with positive optical power, an eighth lens L8 with positive optical power, a ninth lens L9 with negative optical power, a tenth lens L10 with positive optical power, an eleventh lens L11 with negative optical power, a twelfth lens L12 with positive optical power, and a thirteenth lens L13 with positive optical power, all arranged sequentially along the optical axis. Each lens is a glass spherical lens.

[0056] The miniaturized large target projection lens also includes an aperture stop STO, which is located between the sixth lens L6 and the seventh lens L7, or between the seventh lens L7 and the eighth lens L8.

[0057] Furthermore, the miniaturized large-target projection lens also meets the following conditions:

[0058] 13.13≤f≤15.8;54≤OAL≤57

[0059] Where f is the effective focal length of the miniaturized large-target projection lens, in mm; OAL is the on-axis distance from the object side of the first lens L1 to the image side of the thirteenth lens L13, in mm.

[0060] The system comprises several lenses: a first lens L1 with positive optical power, providing sufficient light height for the edge field of view, which helps reduce optical distortion at the edges and provides a solution for small-diameter front-end lenses; a second lens L2 with negative optical power, which can quickly compress light height and, together with the first lens L1, reduce head size; a third lens L3 with negative optical power, which can share the optical power of the second lens L2, providing a deflection angle for edge rays, smoothing the light, and reducing field aberrations; a fourth lens L4 with positive optical power, which provides higher light height on convex surfaces, offering some field curvature compensation and resulting in high MTF concentration of the optical system; a fifth lens L5 with negative optical power, which, together with the fourth lens L4, forms a negative-positive lens combination, causing most primary aberrations of opposite signs to cancel each other out, ultimately obtaining higher-order aberrations beneficial to the aberration balance of the system, thereby compensating for residual aberrations in other lens components; a sixth lens L6 with positive optical power, which has a high refractive index, can effectively compress the system length, making the system more compact and miniaturized; and a seventh lens L7 with positive optical power, which connects to the front... The rear lens group smooths the light path near the STO aperture stop, helping to reduce lens sensitivity and improve product yield and reliability. The eighth lens, L8, with positive power and a high Abbe number, reduces chromatic aberration introduced into the system. The ninth lens, L9, with negative power and a lower Abbe number, works in conjunction with the eighth lens L8 to reduce chromatic aberration across the entire system. The tenth lens, L10, also with positive power and a high Abbe number material, further reduces chromatic aberration and works in conjunction with the negative lens group. The ninth lens (L9) forms a complementary relationship in terms of chromatic aberration and spherical aberration; the eleventh lens (L11) with negative optical power and the twelfth lens (L12) with positive optical power can form a cemented doublet, or a cemented triplicate with the tenth lens (L10), which can greatly reduce the overall chromatic aberration of the system, ensure low levels of axial and transverse chromatic aberration, and achieve clarity for both monochromatic and mixed-color light; the thirteenth lens (L13) with positive optical power has a high refractive index and a flat surface, which helps to reduce spherical aberration and correct the incident angle of the principal ray.

[0061] The stop-to-focus (STO) aperture can be positioned between the sixth lens (L6) and the seventh lens (L7), or between the seventh lens (L7) and the eighth lens (L8). The STO divides the front and rear lens groups; the object-side lenses of the STO form the front lens group, and the image-side lenses form the rear lens group. Located in the center of the lens, the STO helps balance the vertical light rays at the edges of the field of view, ensuring edge brightness while reducing the principal ray angle of the lens, allowing the lens to better match the projection light system.

[0062] Additionally, f can be 13.432, 15.615, 14.712, 13.993, or 13.13 mm. Meeting the above conditions, a 0.47” DMD chip with a 105% offset allows the lens to have a wide angle of view, projecting the required image size at short distances. Exceeding the upper limit results in a smaller lens angle and a smaller image size; falling below the lower limit increases the lens angle, requiring a more complex lens design, thus failing to meet the miniaturization and low-cost requirements. OAL can be 55.6, 56, 56.2, or 57 mm. Meeting the above conditions allows the lens to have a small, compact size, meeting miniaturization requirements; exceeding the upper limit fails to meet miniaturization requirements; falling below the lower limit compresses the lens space, hindering sharpness improvement, increasing material costs, and potentially leading to excessive costs.

[0063] In one embodiment, the first lens L1 is a convex-plano lens or a convex-concave lens, the second lens L2 is a convex-concave lens, the third lens L3 is a convex-concave lens, the fourth lens L4 is a biconvex lens or a plano-convex lens, the fifth lens L5 is a biconcave lens, the sixth lens L6 is a plano-convex lens or a convex-plano lens, the seventh lens L7 is a biconvex lens, the eighth lens L8 is a biconvex lens or a concave-convex lens, the ninth lens L9 is a convex-concave lens, the tenth lens L10 is a biconvex lens or a concave-convex lens, the eleventh lens L11 is a biconcave lens, the twelfth lens L12 is a biconvex lens, and the thirteenth lens L13 is a biconvex lens. The miniaturized large target projection lens also satisfies the following conditions:

[0064] <![CDATA[56.10<f1<68.9]]> <![CDATA[23.37<R 11 <32.52]]> <![CDATA[66.01<R 12 <131.2]]> <![CDATA[-33.36<f2<-25.5]]> <![CDATA[17.05<R 21 <23.89]]> <![CDATA[8.18<R 22 <10.52]]> <![CDATA[-34.76<f3<-27.02]]> <![CDATA[22.02<R 31 <34.78]]> <![CDATA[10.02<R 32 <11.35]]> <![CDATA[24.25<f4<31.35]]> <![CDATA[34.86<R 41 <285.9]]> <![CDATA[-210.59<R 42 <-30.5]]> <![CDATA[-18.66<f5<-17.2]]> <![CDATA[-45.51<R 51 <-20.32]]> <![CDATA[10.12<R 52 <16.8]]> <![CDATA[35.3<f6<91.2]]> <![CDATA[45.52<R 61 <+∞]]> <![CDATA[-220.7<R 62 <-42.27]]> <![CDATA[18.7<f7<21.2]]> <![CDATA[-12.6<R 71 <107.9]]> <![CDATA[-∞<R 72 <-15.17]]> <![CDATA[33.1<f8<99.8]]> <![CDATA[-135.1<R 81 <25.95]]> <![CDATA[-49.7<R 82 <-14.01]]> <![CDATA[-39.5<f9<-19.2]]> <![CDATA[-216.6<R 91 <517.29]]> <![CDATA[19.42<R 92 <22.6]]> <![CDATA[15.05<f 10 <29.95]]> <![CDATA[-166.5<R 101 <187.9]]> <![CDATA[-17.2<R 102 <-9.01]]> <![CDATA[-11.6<f 11 <-8.01]]> <![CDATA[-13.53<R 111 <-8.9]]> <![CDATA[-9.96<R 112 <34.9]]> <![CDATA[19.23<f 12 <21.9]]> <![CDATA[24.28<R 121 <35.78]]> <![CDATA[-22.16<R 122 <-18.37 <!-- 5 -->]]> <![CDATA[24.5<f 13 <28.6]]> <![CDATA[42.93<R 131 <56.3]]> <![CDATA[-69.7<R 132 <-41.2]]>

[0065] Among them, f1~f 13 The focal lengths of lenses L1 through L13 are listed in mm; R 11 R 21 R 31 R 41 R 51 R 61 R 71 R 81 R 91 R 101 R 111 R 121 R 131 The following are the radii of curvature of the object-side surfaces of lenses L1 through L13, in mm; R 12 R 22 R 32 R 42 R 52 R 62 R 72 R 82 R 92 R 102 R112 R 122 R 132 The radii of curvature of the image-side surfaces of lenses L1 through L13 are in mm, respectively; "-" indicates the negative direction.

[0066] By reasonably limiting the focal length, shape, and radius of curvature of each lens, it is beneficial to achieve miniaturization and large target surface design of the projection lens, thereby obtaining good imaging quality.

[0067] In one embodiment, the miniaturized large target projection lens also satisfies the following condition:

[0068]

[0069] Where D is the entrance pupil diameter, in mm.

[0070] Specifically, the f / D ratio can be 1.98, 1.995, 2.019, 2.014, or 2.03. Meeting these conditions indicates a lens with a large aperture, suitable for both low-cost, low-light projection devices and high-light projection devices. This gives the lens a wide range of applications, meeting the needs of most projection scenarios on the market.

[0071] In one embodiment, the miniaturized large target projection lens also satisfies the following condition:

[0072]

[0073] Wherein, SD1 is the edge ray height of the object side of the first lens L1, and SD13 is the edge ray height of the image side of the thirteenth lens L13.

[0074] Specifically, SD1 / SD13 can be: 1.057, 1.25, 1.191, 1.301, 1.202. Meeting the above conditions, the aperture of the first lens L1 and the thirteenth lens L13 are very close, allowing the head and tail diameters of the structure to be essentially the same. This facilitates miniaturization of the overall projection design, reduces the exposed projection area, improves integration, reduces discomfort from exposure, and enhances the aesthetics of the projection device within the vehicle's interior space. Exceeding the upper limit results in an excessively large head size, reducing the aesthetics of the application; falling below the lower limit results in an excessively small head size, increasing design difficulty and requiring more lenses to compensate for optical distortion caused by the small head, which is detrimental to cost reduction.

[0075] In one embodiment, the miniaturized large target projection lens also satisfies the following condition:

[0076] -1% ≤ DIST ≤ -0.5%, RI ≥ 60%

[0077] Wherein, FOV is the full field of view of the maximum field of view, DIST is the maximum optical distortion from the center to the edge of the field of view, and RI is the relative illumination of the miniaturized large target projection lens on the image plane IMA.

[0078] Specifically, FOV / DIST can be: -60.2, -71.3, -80.6, -79.2, -62.6, in ° / %. Meeting these conditions ensures that, under wide-angle FOV conditions, the maximum optical distortion can be controlled within a reasonable range, and is suitable for all-glass distortion compensation, keeping the lens's FOV and DIST within a reasonable range, guaranteeing low distortion in projection size and image frame. Additionally, DIST can be: -0.88%, -0.76%, -0.6%, -0.65%, -0.55%. Meeting these conditions ensures that lens optical distortion is within a reasonable range; at this point, the projected TV distortion is less than 0.5%, and the human eye can hardly perceive the image distortion, contributing to improved viewing comfort. Exceeding this range results in excessive optical distortion, causing significant image distortion and potentially causing viewing discomfort. RI can be: 68%, 71%, 75%, 65%, 78%. Meeting the above conditions ensures good illumination uniformity within an offset range of 105%, preventing vignetting caused by excessively low edge illumination. Beyond this range, relatively low illumination makes vignetting more likely, affecting viewing comfort.

[0079] In one embodiment, the miniaturized large target projection lens also satisfies the following condition:

[0080] 6≤th4+th6+th11+th13≤11

[0081] Where th4 is the median thickness of the fourth lens L4, th6 is the median thickness of the sixth lens L6, th11 is the median thickness of the eleventh lens L11, and th13 is the median thickness of the thirteenth lens L13, all in mm.

[0082] Specifically, th4+th6+th11+th13 can be 9.29, 8.38, 7.6, 10.37, 7.2, and 6.8 mm. Due to the distribution of optical power, the fourth lens L4, sixth lens L6, eleventh lens L11, and thirteenth lens L13 are often made of materials with high refractive indexes. High refractive index materials, due to their inherent characteristics, have low short-wavelength transmittance. To enhance the short-wavelength transmittance of the lens, the thickness of the high refractive index material must be strictly controlled. Meeting the above conditions, the overall thickness of the high refractive index material can be controlled within a reasonable range, ensuring a small difference between the short-wavelength and long-wavelength transmittance of the lens and avoiding color temperature deviation problems. Exceeding the upper limit, the fourth lens L4, sixth lens L6, eleventh lens L11, and thirteenth lens L13 become too thick, easily causing low short-wavelength transmittance, affecting the color temperature and brightness of the projected image. Below the lower limit, the lens thickness is too thin, which is not conducive to processing.

[0083] In one embodiment, the miniaturized large target projection lens also satisfies the following condition:

[0084] 115≤abv10+abv12≤160

[0085] Where abv10 is the Abbe number of the tenth lens L10, and abv12 is the Abbe number of the twelfth lens L12.

[0086] Specifically, abv10 + abv12 can be: 135.62, 153.78, 147.94, 120.37, 155.32. The tenth lens L10 and the twelfth lens L12 are made of low-refractive-index, high-Abbe-number materials, and their material range is close to that of negative dn / dt (refractive-index temperature coefficient) materials, satisfying the above conditions. The selection of suitable negative dn / dt materials for the tenth lens L10 and the twelfth lens L12 compensates for the excessive expansion and contraction of the rear focal length at high and low temperatures, enabling the lens to achieve an optically athermal design. This allows it to meet the temperature range of -40℃ to 85℃ in automotive applications, and without plastic lenses; that is, when using an all-glass structure, high temperatures can be covered up to 105℃. Beyond this limit, the material selection does not meet the high and low temperature compensation requirements.

[0087] In one embodiment, the miniaturized large-target projection lens satisfies the following condition:

[0088]

[0089] Where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens.

[0090] Specifically, f1 / (f2+f3) can be: -1.037, -0.97, -1.075, -1.23, -1.16. Satisfying the above conditions, the first lens L1, the second lens L2, and the third lens L3 form a positive-negative-negative combination, limiting the effective focal length to a reasonable range. This allows for the use of positive-negative combination lenses to achieve a small aperture, low distortion, reduced aberrations, improved overall sharpness, and high resolution. Exceeding this range results in uneven optical power distribution, making it difficult to achieve a small-head solution.

[0091] In one embodiment, the miniaturized large target projection lens further includes a prism L14, which is located between the thirteenth lens L13 and the image plane IMA.

[0092] Prism L14 is an equivalent flat plate used to converge light from different light sources, such as providing appropriate reflection and refraction angles for each light ray. This is a well-known technique and will not be described further here.

[0093] In one embodiment, the miniaturized large target projection lens also satisfies the following condition:

[0094] CRA≤2.0°, 20mm≤FFL≤30mm

[0095] Wherein, CRA is the maximum incident angle of the miniaturized large-target projection lens on the image plane IMA, and FFL is the on-axis distance from the eleventh lens L11 to the image plane IMA.

[0096] Specifically, CRA can be: 0.8, 1.7, 1.0, 1.5, 0.6, in degrees. Meeting these conditions ensures the lens's telecentricity is within a small range, guaranteeing alignment between the lens and the light output direction, improving light output efficiency from the center to the edge of the image, and preventing uneven brightness. Exceeding this range results in excessive telecentricity, easily leading to low light output efficiency and affecting image brightness and uniformity. Additionally, FFL can be: 23.2, 20.5, 25.6, 27.83, 29.6, in mm. Meeting these conditions allows the lens to be matched with a larger back focal length, providing ample prism space and light output / heat dissipation space, and accommodating more projection engines. Exceeding the upper limit results in an excessively large back focal length, increasing lens design difficulty and cost; below the lower limit, the back focal length is too small, hindering illumination path arrangement and engine heat dissipation, affecting the user experience.

[0097] For ease of understanding, the following detailed embodiments are provided. The reference wavelength for the effective focal length, Abbe number, and refractive index in each embodiment is 520 nm.

[0098] Example 1:

[0099] like Figure 1As shown, in this embodiment, the miniaturized large-area projection lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture stop STO, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, a prism L14, a protective glass CG, and a DMD chip (image plane IMA), wherein the tenth lens L10, the eleventh lens L11, and the twelfth lens L12 form a cemented triplet lens. The effective focal length of this optical system is f = 15.61 mm, the aperture number Fno = 2.0, the maximum image plane size is 16 mm, and the on-axis distance OAL from the object-side surface of the first lens L1 to the image-side surface of the thirteenth lens L13 is 56 mm. Therefore, this optical system can achieve high resolution, miniaturization, and a large image plane.

[0100] Specifically, the values ​​of the lens parameters in this embodiment are shown in Table 1 below:

[0101] Table 1

[0102] Face number Surface type Radius of curvature (mm) Thickness (mm) Refractive index Abbe number OBJ spherical unlimited 1182.000 S1 spherical 27.815 3.768 1.618 63.39 S2 spherical 106.137 0.154 S3 spherical 23.796 3.059 1.589 61.25 S4 spherical 8.802 3.696 S5 spherical 34.665 1.123 1.487 70.44 S6 spherical 11.305 3.162 S7 spherical 263.918 1.670 1.923 20.88 S8 spherical -30.951 0.303 S9 spherical -21.324 1.117 1.497 81.61 S10 spherical 16.798 2.000 S11 spherical 48.520 1.285 2.001 29.13 S12 spherical -156.319 0.860 STO(S13) spherical unlimited 4.321 S14 spherical 38.465 4.836 1.691 54.82 S15 spherical -20.143 0.107 S16 spherical -132.169 1.489 1.589 61.25 S17 spherical -32.201 0.668 S18 spherical 515.296 1.788 1.847 23.78 S19 spherical 19.842 1.659 S20 spherical 180.921 4.992 1.569 71.30 S21 spherical -9.037 1.100 1.785 25.72 S22 spherical 24.887 7.885 1.569 71.30 S23 spherical -18.954 1.427 S24 spherical 43.933 3.530 1.946 17.94 S25 spherical -68.309 9.826 S26 spherical unlimited 16.000 1.713 53.83 S27 spherical unlimited 0.600 S28 spherical unlimited 1.100 1.510 62.91 S29 spherical unlimited 0.303 IMA spherical unlimited 0.000

[0103] like Figure 1 As shown, surface number OBJ represents the object surface, and surface numbers S1, S3, S5, S7, S9, S11, S14, S16, S18, S20, S21, S22, S24, S26 to S28 represent the object surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the prism L14, and the protective glass CG, respectively. Surface numbers S2, S4, S6, S8, and S10 represent the object surface of the protective glass CG. S12, S15, S17, S19, S21, S22, S23, S25, and S27 to S29 represent, respectively, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the prism L14, and the image-side surface of the protective glass CG. The cemented surface of the cemented lens assembly is considered as one surface. STO represents the aperture stop, i.e., surface number S13, and surface number IMA represents the imaging surface (image plane) of the DMD chip. The DMD chip is a Digital Micromirror Device (DMD).

[0104] Figure 2The longitudinal spherical aberration diagram (LONGITUD INAL SPHERICAL ABER.) of the optical system represents the deviation of the convergence focal point of light rays of different wavelengths after passing through the lens. The vertical axis of the LONGITUD spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the image plane to the intersection of the ray and the optical axis. As shown in the LONGITUD spherical aberration diagram, in this embodiment, the deviation of the convergence focal point of light rays of different wavelengths tends to be consistent, effectively suppressing blur or halo in the image, and the difference between single-wavelength and polychromatic wavelengths is small. Figure 2 It also includes the field curvature diagrams of the optical system, where the S-curve represents the sagittal field curvature at a wavelength of 520 nm, and the T-curve represents the meridional field curvature at a wavelength of 520 nm. As can be seen from the figure, the field curvature of the optical system is small, and the field curvature and astigmatism of each field of view are well corrected. Figure 2 It also includes the optical system distortion diagram. As can be seen from the diagram, the image distortion caused by the main beam is small, and the imaging quality of the system is excellent. Figure 3 The graph shows the relationship between MTF and frequency under different fields of view. The center and edges of the field of view exhibit clear imaging at various frequencies, and the MTF for all fields of view is greater than 0.59 at the limiting frequency of 93 lp / mm. In summary, the longitudinal spherical aberration, field curvature, and distortion of this optical system are well controlled, resulting in excellent imaging quality.

[0105] Example 2:

[0106] like Figure 4 As shown, in this embodiment, the miniaturized large-area projection lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture stop STO, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, a prism L14, a protective glass CG, and a DMD chip (image plane IMA), wherein the eleventh lens L11 and the twelfth lens L12 form a cemented doublet. The effective focal length of this optical system is f = 14.713 mm, the aperture number Fno = 2.03, the maximum image plane is 16 mm, and the on-axis distance OAL from the object side of the first lens L1 to the image side of the thirteenth lens L13 is 55.93 mm; it can be seen that this optical system can achieve the effects of high resolution, miniaturization, and a large image plane.

[0107] Specifically, the values ​​of the lens parameters in this embodiment are shown in Table 2 below:

[0108] Table 2

[0109]

[0110]

[0111] like Figure 4 As shown, surface number OBJ represents the object surface, and surface numbers S1, S3, S5, S7, S9, S11, S13, S16, S18, S20, S22, S23, S25, S27 to S29 represent the object surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the prism L14, and the protective glass CG, respectively. Surface numbers S2, S4, S6, S8, and S10 represent the object surface of the protective glass CG. S12, S14, S17, S19, S21, S23, S24, S26, S28 to S30 represent, respectively, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the prism L14, and the image-side surface of the protective glass CG. The cemented surface of the cemented lens assembly is considered as one surface. STO represents the aperture stop, i.e., surface number S15. Surface number IMA represents the imaging surface (image plane) of the DMD chip. The DMD chip is a Digital Micromirror Device (DMD).

[0112] Figure 5 The longitudinal spherical aberration diagram (LONGITUD INAL SPHERICAL ABER.) of the optical system represents the deviation of the convergence focal point of light rays of different wavelengths after passing through the lens. The vertical axis of the LONGITUD spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the image plane to the intersection of the ray and the optical axis. As shown in the LONGITUD spherical aberration diagram, in this embodiment, the deviation of the convergence focal point of light rays of different wavelengths tends to be consistent, effectively suppressing blur or halo in the image, and the difference between single-wavelength and polychromatic wavelengths is small. Figure 5 It also includes the field curvature diagrams of the optical system, where the S-curve represents the sagittal field curvature at a wavelength of 520 nm, and the T-curve represents the meridional field curvature at a wavelength of 520 nm. As can be seen from the figure, the field curvature of the optical system is small, and the field curvature and astigmatism of each field of view are well corrected. Figure 5It also includes the optical system distortion diagram. As can be seen from the diagram, the image distortion caused by the main beam is small, and the imaging quality of the system is excellent. Figure 6 The graph shows the relationship between MTF and frequency under different fields of view. The center and edges of the field of view exhibit clear imaging at various frequencies, and the MTF for all fields of view is greater than 0.58 at the limiting frequency of 93 lp / mm. In summary, the longitudinal spherical aberration, field curvature, and distortion of this optical system are well controlled, resulting in excellent imaging quality.

[0113] Example 3:

[0114] like Figure 7 As shown, in this embodiment, the miniaturized large-area projection lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture stop STO, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, a prism L14, a protective glass CG, and a DMD chip (image plane IMA), wherein the tenth lens L10, the eleventh lens L11, and the twelfth lens L12 form a cemented triplet lens. The effective focal length of this optical system is f = 13.993 mm, the aperture number Fno = 2.01, the maximum image plane size is 15.8 mm, and the on-axis distance OAL from the object-side surface of the first lens L1 to the image-side surface of the thirteenth lens L13 is 55.25 mm. Therefore, this optical system can achieve high resolution, miniaturization, and a large image plane.

[0115] Specifically, the values ​​of the lens parameters in this embodiment are shown in Table 3 below:

[0116] Table 3

[0117]

[0118]

[0119] like Figure 7As shown, surface number OBJ represents the object surface, and surface numbers S1, S3, S5, S7, S9, S11, S14, S16, S18, S20, S21, S22, S24, S26 to S28 represent the object surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the prism L14, and the protective glass CG, respectively. Surface numbers S2, S4, S6, S8, and S10 represent the object surface of the protective glass CG. S12, S15, S17, S19, S21, S22, S23, S25, and S27 to S29 represent, respectively, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the prism L14, and the image-side surface of the protective glass CG. The cemented surface of the cemented lens assembly is considered as one surface. STO represents the aperture stop, i.e., surface number S13, and surface number IMA represents the imaging surface (image plane) of the DMD chip. The DMD chip is a Digital Micromirror Device (DMD).

[0120] Figure 8 The longitudinal spherical aberration diagram (LONGITUD INAL SPHERICAL ABER.) of the optical system represents the deviation of the convergence focal point of light rays of different wavelengths after passing through the lens. The vertical axis of the LONGITUD spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the image plane to the intersection of the ray and the optical axis. As shown in the LONGITUD spherical aberration diagram, in this embodiment, the deviation of the convergence focal point of light rays of different wavelengths tends to be consistent, effectively suppressing blur or halo in the image, and the difference between single-wavelength and polychromatic wavelengths is small. Figure 8 It also includes the field curvature diagrams of the optical system, where the S-curve represents the sagittal field curvature at a wavelength of 520 nm, and the T-curve represents the meridional field curvature at a wavelength of 520 nm. As can be seen from the figure, the field curvature of the optical system is small, and the field curvature and astigmatism of each field of view are well corrected. Figure 8 It also includes the optical system distortion diagram. As can be seen from the diagram, the image distortion caused by the main beam is small, and the imaging quality of the system is excellent. Figure 9The graph shows the relationship between MTF and frequency under different fields of view. The center and edges of the field of view exhibit clear imaging at various frequencies, and the MTF for all fields of view is greater than 0.59 at the limiting frequency of 93 lp / mm. In summary, the longitudinal spherical aberration, field curvature, and distortion of this optical system are well controlled, resulting in excellent imaging quality.

[0121] Example 4:

[0122] like Figure 10 As shown, in this embodiment, the miniaturized large-area projection lens includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture stop STO, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, a prism L14, a protective glass CG, and a DMD chip (image plane IMA), wherein the tenth lens L10, the eleventh lens L11, and the twelfth lens L12 form a cemented triplet lens. The effective focal length of this optical system is f = 13.432 mm, the aperture number Fno = 2.02, the maximum image plane size is 15.8 mm, and the on-axis distance OAL from the object-side surface of the first lens L1 to the image-side surface of the thirteenth lens L13 is 55.266 mm. Therefore, this optical system can achieve high resolution, miniaturization, and a large image plane.

[0123] Specifically, the values ​​of the lens parameters in this embodiment are shown in Table 4 below:

[0124] Table 4

[0125] Face number Surface type Radius of curvature (mm) Thickness (mm) Refractive index Abbe number OBJ spherical unlimited 1023.000 S1 spherical 32.430 3.730 1.613 60.38 S2 spherical 131.101 0.516 S3 spherical 21.623 1.121 1.589 61.25 S4 spherical 10.132 3.629 S5 spherical 22.830 1.000 1.620 60.37 S6 spherical 10.113 3.122 S7 spherical 34.978 2.067 2.000 25.46 S8 spherical -81.456 0.372 S9 spherical -40.136 1.370 1.487 70.42 S10 spherical 10.269 1.811 S11 spherical 159.765 2.416 2.000 25.46 S12 spherical -218.758 2.881 STO(S13) spherical unlimited 1.992 S14 spherical 64.319 3.534 1.717 47.92 S15 spherical -16.822 0.128 S16 spherical -19.988 4.653 1.457 90.27 S17 spherical -14.356 1.370 S18 spherical 109.586 1.299 1.673 32.18 S19 spherical 21.476 1.057 S20 spherical 102.175 5.057 1.593 68.34 S21 spherical -9.719 2.313 1.847 23.79 S22 spherical 27.157 5.780 1.593 68.34 S23 spherical -21.158 0.224 S24 spherical 55.384 3.822 1.946 17.94 S25 spherical -42.800 9.830 S26 spherical unlimited 16.000 1.713 53.83 S27 spherical unlimited 0.600 S28 spherical unlimited 1.100 1.510 62.91 S29 spherical unlimited 0.303 IMA spherical unlimited 0.000

[0126] like Figure 10As shown, surface number OBJ represents the object surface, and surface numbers S1, S3, S5, S7, S9, S11, S14, S16, S18, S20, S21, S22, S24, S26 to S28 represent the object surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the prism L14, and the protective glass CG, respectively. Surface numbers S2, S4, S6, S8, and S10 represent the object surface of the protective glass CG. S12, S15, S17, S19, S21, S22, S23, S25, and S27 to S29 represent, respectively, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the prism L14, and the image-side surface of the protective glass CG. The cemented surface of the cemented lens assembly is considered as one surface. STO represents the aperture stop, i.e., surface number S13, and surface number IMA represents the imaging surface (image plane) of the DMD chip. The DMD chip is a Digital Micromirror Device (DMD).

[0127] Figure 11 The longitudinal spherical aberration diagram (LONGITUD INAL SPHERICAL ABER.) of the optical system represents the deviation of the convergence focal point of light rays of different wavelengths after passing through the lens. The vertical axis of the LONGITUD spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the image plane to the intersection of the ray and the optical axis. As shown in the LONGITUD spherical aberration diagram, in this embodiment, the deviation of the convergence focal point of light rays of different wavelengths tends to be consistent, effectively suppressing blur or halo in the image, and the difference between single-wavelength and polychromatic wavelengths is small. Figure 11 It also includes the field curvature diagrams of the optical system, where the S-curve represents the sagittal field curvature at a wavelength of 520 nm, and the T-curve represents the meridional field curvature at a wavelength of 520 nm. As can be seen from the figure, the field curvature of the optical system is small, and the field curvature and astigmatism of each field of view are well corrected. Figure 11 It also includes the optical system distortion diagram. As can be seen from the diagram, the image distortion caused by the main beam is small, and the imaging quality of the system is excellent. Figure 12The graph shows the relationship between MTF and frequency under different fields of view. The center and edges of the field of view exhibit clear imaging at various frequencies, and the MTF of all fields of view is greater than 0.6 at the limiting frequency of 93 lp / mm. In summary, the longitudinal spherical aberration, field curvature, and distortion of this optical system are well controlled, resulting in excellent imaging quality.

[0128] 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.

[0129] 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 invention patent. 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 all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A miniaturized large target surface projection lens characterized by: The small-size large-target-surface projection lens comprises, sequentially arranged along the optical axis, a first lens (L1) with positive focal power, a second lens (L2) with negative focal power, a third lens (L3) with negative focal power, a fourth lens (L4) with positive focal power, a fifth lens (L5) with negative focal power, a sixth lens (L6) with positive focal power, a seventh lens (L7) with positive focal power, an eighth lens (L8) with positive focal power, a ninth lens (L9) with negative focal power, a tenth lens (L10) with positive focal power, an eleventh lens (L11) with negative focal power, a twelfth lens (L12) with positive focal power, and a thirteenth lens (L13) with positive focal power, the total number of lenses with focal power of the small-size large-target-surface projection lens is 13, the second lens (L2) is a convex-concave lens, the third lens (L3) is a convex-concave lens, the fifth lens (L5) is a double-concave lens, the seventh lens (L7) is a double-convex lens, the ninth lens (L9) is a convex-concave lens, the eleventh lens (L11) is a double-concave lens, the twelfth lens (L12) is a double-convex lens, and the thirteenth lens (L13) is a double-convex lens, each of the lenses is a glass spherical lens; The small-size large-target-surface projection lens further comprises a stop (STO) located between the sixth lens (L6) and the seventh lens (L7), or between the seventh lens (L7) and the eighth lens (L8); And the small-size large-target-surface projection lens further satisfies the following conditions: 13.13≤f≤15.8; 54≤OAL≤57 Wherein, f is the effective focal length of the small-size large-target-surface projection lens, with the unit of mm; OAL is the axial distance from the object side of the first lens (L1) to the image side of the thirteenth lens (L13), with the unit of mm.

2. The miniaturized large target surface projection lens according to claim 1, characterized in that: The first lens (L1) is a convex-flat lens or a convex-concave lens, the fourth lens (L4) is a double-convex lens or a plano-convex lens, the sixth lens (L6) is a plano-convex lens or a convex-flat lens, the eighth lens (L8) is a double-convex lens or a concave-convex lens, the tenth lens (L10) is a double-convex lens or a concave-convex lens, and the small-size large-target-surface projection lens further satisfies the following conditions: Among them, f1~f 13 The focal lengths of the first lens (L1) to the thirteenth lens (L13) are in mm, respectively; R 11 R 21 R 31 R 41 R 51 R 61 R 71 R 81 R 91 R 101 R 111 R 121 R 131 The radii of curvature of the object-side surfaces of the first lens (L1) to the thirteenth lens (L13), in mm, are respectively; R 12 R 22 R 32 R 42 R 52 R 62 R 72 R 82 R 92 R 102 R 112 R 122 R 132 The radii of curvature of the image-side surfaces of the first lens (L1) to the thirteenth lens (L13) are in mm, respectively; "-" indicates the negative direction.

3. The miniaturized large target surface projection lens of claim 1, wherein: The small-size large-target-surface projection lens further satisfies the following conditions: Wherein, D is the entrance pupil diameter, with the unit of mm.

4. The miniaturized large target surface projection lens of claim 1, wherein: The small-size large-target-surface projection lens further satisfies the following conditions: Wherein, SD1 is the edge ray height of the object side of the first lens (L1), and SD13 is the edge ray height of the image side of the thirteenth lens (L13).

5. The miniaturized large target surface projection lens of claim 1, wherein: The small-size large-target-surface projection lens further satisfies the following conditions: Wherein, FOV is the full field of view of the maximum field of view, DIST is the maximum optical distortion from the center to the edge field of view, and RI is the relative illumination of the small-size large-target-surface projection lens on the image plane (IMA).

6. The miniaturized large target surface projection lens of claim 1, wherein: The small-size large-target-surface projection lens further satisfies the following conditions: 6≤th4+th6+th11+th13≤11 Wherein, th4 is the middle thickness of the fourth lens (L4), th6 is the middle thickness of the sixth lens (L6), th11 is the middle thickness of the eleventh lens (L11), th13 is the middle thickness of the thirteenth lens (L13), and the unit is mm.

7. The compact large target surface projection lens of claim 1, wherein: The small-size large-target-surface projection lens also satisfies the following condition: 115≤abv10+abv12≤160 Wherein, abv10 is the Abbe number of the tenth lens (L10), and abv12 is the Abbe number of the twelfth lens (L12).

8. The miniaturized large target surface projection lens of claim 1, wherein: The small-size large-target-surface projection lens also satisfies the following condition: Wherein, f1 is the effective focal length of the first lens (L1), f2 is the effective focal length of the second lens (L2), and f3 is the effective focal length of the third lens (L3), and the unit is mm.

9. The miniaturized large target surface projection lens of claim 1, wherein: The small-size large-target-surface projection lens also comprises a prism (L14) located between the thirteenth lens (L13) and the image surface (IMA).

10. The miniaturized large target surface projection lens according to claim 9, characterized in that: The small-size large-target-surface projection lens also satisfies the following condition: CRA≤2.0°, 20mm≤FFL≤30mm Wherein, CRA is the maximum incident angle of the small-size large-target-surface projection lens at the image surface (IMA), and FFL is the on-axis distance from the image side surface of the thirteenth lens (L13) to the image surface (IMA).

Images