Zoom projection optical system and projection apparatus

Abstract

This invention proposes a zoom projection optical system and projection device. Based on the field of optical imaging technology, the zoom projection optical system includes a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with positive optical power, a fourth lens group with positive optical power, a fifth lens group with positive optical power, a sixth lens group with positive optical power, a galvanometer, a prism, a protective glass, and a light-emitting chip. The second, third, fourth, and fifth lens groups are movable along the optical axis to zoom the zoom projection optical system. The first lens group moves along the optical axis to focus the zoom projection optical system. The sixth lens group is fixed. The technical solution provided by this invention, by employing a six-element structure and rationally setting the optical power and materials of the fourteen lenses, achieves a zoom projection optical system with high magnification, large aperture, good thermal stability, and high image quality.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, and in particular to a zoom projection optical system and projection device. Background Technology

[0002] In recent years, with the development of projection technology, projectors have been widely used in home, education, and office settings. Most projection devices on the market are direct projection types. Zoom projectors, however, are highly favored because they allow for continuous adjustment of the image size without changing the projection distance.

[0003] Common projectors on the market usually have a variable aperture to improve image contrast and image quality. However, in some large zoom lenses, when the aperture is adjusted to the maximum, aberrations are often generated, resulting in poor image quality. When the aperture is adjusted to the minimum, light decay and thermal defocusing often occur, which also leads to poor image quality. Therefore, it is impossible to simultaneously meet the requirements of large zoom, large aperture, good thermal stability and high image quality. Summary of the Invention

[0004] The main objective of this invention is to propose a zoom projection optical system and projection device, aiming to provide a zoom projection optical system with large zoom, large aperture, good thermal stability, and high imaging quality.

[0005] To achieve the above objectives, the present invention proposes a zoom projection optical system. The zoom projection optical system has an object side and an image side arranged opposite to each other along the optical axis. The zoom projection optical system includes, from the object side to the image side, a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with positive optical power, a fourth lens group with positive optical power, a fifth lens group with positive optical power, a sixth lens group with positive optical power, a galvanometer, a prism, a protective glass, and a light-emitting chip. The second, third, fourth, and fifth lens groups are movable along the optical axis to zoom the zoom projection optical system. The first lens group moves cooperatively along the optical axis to focus the zoom projection optical system. The sixth lens group is fixed.

[0006] The first lens group includes a first lens with negative optical power, a second lens with negative optical power, and a third lens with negative optical power arranged sequentially from the object side to the image side;

[0007] The second lens group includes a fourth lens with positive optical power;

[0008] The third lens group includes a fifth lens with positive optical power;

[0009] The fourth lens group includes a sixth lens with positive optical power;

[0010] The fifth lens group includes a seventh lens with positive optical power, an eighth lens with negative optical power, a ninth lens with positive optical power, a tenth lens with negative optical power, an eleventh lens with positive optical power, a twelfth lens with negative optical power, and a thirteenth lens with positive optical power, arranged sequentially from the object side to the image side.

[0011] The sixth lens group includes a fourteenth lens with positive optical power;

[0012] The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens, the thirteenth lens, and the fourteenth lens are all glass lenses.

[0013] In one embodiment, the zoom projection optical system further includes an aperture stop disposed between the sixth lens and the seventh lens.

[0014] In one embodiment, the second and ninth lenses are aspherical lenses, and the first, third, fourth, fifth, sixth, seventh, eighth, tenth, eleventh, twelfth, thirteenth, and fourteenth lenses are spherical lenses.

[0015] In one embodiment, the seventh lens is cemented to the eighth lens, and the tenth, eleventh, and twelfth lenses are cemented to each other.

[0016] In one embodiment, the first lens is a concave-convex lens, and its object-side surface is convex.

[0017] The second lens is a concave-convex lens, and its object-side surface is convex.

[0018] The third lens is a biconcave lens;

[0019] The fourth lens is a concave-convex lens, and its object-side surface is concave.

[0020] The fifth lens is a biconvex lens;

[0021] The sixth lens is a biconvex lens;

[0022] The seventh lens is a concave-convex lens, and its object-side surface is concave.

[0023] The eighth lens is a biconcave lens;

[0024] The ninth lens is a biconvex lens;

[0025] The tenth lens is a concave-convex lens, and its object-side surface is convex.

[0026] The eleventh lens is a biconvex lens;

[0027] The twelfth lens is a concave-convex lens, and its object-side surface is concave.

[0028] The thirteenth lens is a concave-convex lens, and its object-side surface is concave.

[0029] The object-side surface of the fourteenth lens is convex, and the image-side surface is planar.

[0030] In one embodiment, the focal length of the first lens group is F1, the focal length of the second lens group is F2, the focal length of the third lens group is F3, the focal length of the fourth lens group is F4, the focal length of the fifth lens group is F5, the focal length of the sixth lens group is F6, and the focal length of the zoom projection optical system at the wide-angle end is f, wherein:

[0031] -20mm<F1<-8mm, 50mm<F2<100mm, 40mm<F3<80mm, 35mm<F4<75mm, 45mm<F5<80mm, 40mm<F6<80mm, - 2.2<F1 / f<-0.84, 5.3<F2 / f<10.6, 4.2<F3 / f<8.5, 3.7<F4 / f<8.0, 4.7<F5 / f<8.5, 4.2<F6 / f<6.4.

[0032] In one embodiment, the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, the focal length of the eighth lens is f8, the focal length of the ninth lens is f9, the focal length of the tenth lens is f10, the focal length of the eleventh lens is f11, the focal length of the twelfth lens is f12, the focal length of the thirteenth lens is f13, and the focal length of the fourteenth lens is f14, wherein:

[0033] -80mm<f1<-50mm, -60mm<f2<-30mm, -60mm<f3<-30mm, 50mm<f4<100mm, 40mm<f5<80mm, 35mm<f6<75mm, 30mm<f7<60mm, -3 0mm<f8<-10mm, 20mm<f9<40mm, -50mm<f10<-20mm, 10mm<f11<30mm, -50mm<f12<-20mm, 10mm<f13<60mm, 20mm<f14<50mm.

[0034] In one embodiment, the temperature coefficient of the refractive index of the ninth lens in the range of 60°C to 80°C is dn9 / dt, the temperature coefficient of the refractive index of the tenth lens in the range of 60°C to 80°C is dn10 / dt, the temperature coefficient of the refractive index of the eleventh lens in the range of 60°C to 80°C is dn11 / dt, and the temperature coefficient of the refractive index of the twelfth lens in the range of 60°C to 80°C is dn12 / dt, wherein:

[0035] 3.1×10 -6 / ℃<dn9 / dt<6×10 -6 / ℃, 0<dn10 / dt<3×10 -6 / ℃,-9×10 -6 / ℃<dn11 / dt<-5×10 -6 / ℃, 3×10 -6 / ℃<dn12 / dt<7×10 -6 / ℃.

[0036] In one embodiment, the diameter of the first lens is D1, and the image plane diameter of the zoom projection optical system is IC, wherein:

[0037] D1 < 44 mm, IC ≤ 16 mm.

[0038] The present invention also proposes a projection device, the projection device including the above-mentioned zoom projection optical system, the zoom projection optical system having an object side and an image side arranged opposite to each other along the optical axis, the zoom projection optical system including a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with positive optical power, a fourth lens group with positive optical power, a fifth lens group with positive optical power, a sixth lens group with positive optical power, a galvanometer, a prism, a protective glass, and a light-emitting chip arranged sequentially from the object side to the image side, wherein the second lens group, the third lens group, the fourth lens group and the fifth lens group are movable along the extension direction of the optical axis to zoom the zoom projection optical system, the first lens group moves cooperatively along the optical axis to focus the zoom projection optical system, and the sixth lens group is fixedly arranged;

[0039] The first lens group includes a first lens with negative optical power, a second lens with negative optical power, and a third lens with negative optical power arranged sequentially from the object side to the image side;

[0040] The second lens group includes a fourth lens with positive optical power;

[0041] The third lens group includes a fifth lens with positive optical power;

[0042] The fourth lens group includes a sixth lens with positive optical power;

[0043] The fifth lens group includes a seventh lens with positive optical power, an eighth lens with negative optical power, a ninth lens with positive optical power, a tenth lens with negative optical power, an eleventh lens with positive optical power, a twelfth lens with negative optical power, and a thirteenth lens with positive optical power, arranged sequentially from the object side to the image side.

[0044] The sixth lens group includes a fourteenth lens with positive optical power;

[0045] The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens, the thirteenth lens, and the fourteenth lens are all glass lenses.

[0046] The technical solution provided by this invention, by setting the first lens group with negative optical power, facilitates the collection of light by the optical system and achieves a larger field of view; by setting the sixth lens group with positive optical power, it undertakes a larger optical power of the system, changes the propagation direction of the beam, corrects aberrations in the off-axis field of view, and is more conducive to the beam forming on the image plane; by setting all lenses as glass lenses, aberrations are effectively improved, ensuring no defocusing under high temperature conditions, and the system has good reliability and a longer light exposure life; by reasonably setting the focal length of each lens group to form an anti-long-range structure, the projection ratio is increased, making it easier to achieve a larger magnification. By using fourteen lenses and reasonably setting the optical power and material of each lens, large aperture aberrations and defocusing caused by high temperature are corrected, realizing a zoom projection optical system with large magnification, large aperture, good thermal stability, and high image quality. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0048] Figure 1 A schematic diagram of the structure of an embodiment of the zoom projection optical system provided by the present invention at the wide-angle end;

[0049] Figure 2 for Figure 1 A schematic diagram of the structure of a medium zoom projection optical system at the telephoto end;

[0050] Figure 3 for Figure 1 A schematic diagram of the spot point (SPOT) of a medium zoom projection optical system at the wide-angle end;

[0051] Figure 4 for Figure 1 MTF diagram of a medium zoom projection optical system at the wide-angle end with an aperture of f / 5;

[0052] Figure 5 for Figure 1 MTF diagram of a medium zoom projection optical system at the wide-angle end;

[0053] Figure 6 for Figure 1 A schematic diagram of the spot point (SPOT) at the telephoto end of a medium zoom projection optical system;

[0054] Figure 7 for Figure 1 A schematic diagram of the MTF (Mean Transformation Factor) at the telephoto end of a medium zoom projection optical system.

[0055] Explanation of icon numbers:

[0056] 1000. Zoom projection optical system; 1. First lens group; 11. First lens; 12. Second lens; 13. Third lens; 2. Second lens group; 21. Fourth lens; 3. Third lens group; 31. Fifth lens; 4. Fourth lens group; 41. Sixth lens; 5. Fifth lens group; 51. Seventh lens; 52. Eighth lens; 53. Ninth lens; 54. Tenth lens; 55. Eleventh lens; 56. Twelfth lens; 57. Thirteenth lens; 6. Sixth lens group; 61. Fourteenth lens; a. Aperture; b. Galvanometer; c. Prism; d. Protective glass; e. Light-emitting chip.

[0057] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0059] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0060] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0061] In recent years, with the development of projection technology, projectors have been widely used in home, education, and office settings. Most projectors on the market are direct projection types. However, they generally suffer from the inability to simultaneously achieve small size, narrow projection area, high resolution, and no defocusing at high temperatures. For example, some lenses use more plastic aspherical lenses to improve resolution, but due to the high heat generated by projectors, these lenses are prone to defocusing at high temperatures, affecting the performance. On the other hand, some lenses have fewer lenses to maintain a small size, thus failing to meet the requirements of high resolution and a wide projection area.

[0062] The main objective of this invention is to propose a zoom projection optical system and projection device, aiming to provide a zoom projection optical system with large zoom, large aperture, good thermal stability, and high imaging quality.

[0063] Please see Figure 1 and Figure 2This invention proposes a zoom projection optical system 1000, having an object side and an image side arranged opposite to each other along the optical axis. The zoom projection optical system 1000 includes, from the object side to the image side, a first lens group 1 with negative optical power, a second lens group 2 with positive optical power, a third lens group 3 with positive optical power, a fourth lens group 4 with positive optical power, a fifth lens group 5 with positive optical power, a sixth lens group 6 with positive optical power, a galvanometer b, a prism c, a protective glass d, and a light-emitting chip e. The second lens group 2, third lens group 3, fourth lens group 4, and fifth lens group 5 are movable along the optical axis to zoom the zoom projection optical system 1000. The first lens group 1 moves cooperatively along the optical axis to focus the zoom projection optical system 1000. The sixth lens group 6 is fixed. The first lens group 1 includes, from the object side to the image side, a first lens 11 with negative optical power, a second lens 12 with negative optical power, and a sixth lens group 6. The third lens 13 has negative optical power; the second lens group 2 includes a fourth lens 21 with positive optical power; the third lens group 3 includes a fifth lens 31 with positive optical power; the fourth lens group 4 includes a sixth lens 41 with positive optical power; the fifth lens group 5 includes a seventh lens 51 with positive optical power, an eighth lens 52 with negative optical power, a ninth lens 53 with positive optical power, a tenth lens 54 with negative optical power, and an eleventh lens with positive optical power, arranged sequentially from the object side to the image side. Lens 55, a twelfth lens 56 with negative optical power, and a thirteenth lens 57 with positive optical power; the sixth lens group 6 includes a fourteenth lens 61 with positive optical power; the first lens 11, the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 51, the eighth lens 52, the ninth lens 53, the tenth lens 54, the eleventh lens 55, the twelfth lens 56, the thirteenth lens 57, and the fourteenth lens 61 are all glass lenses.

[0064] The technical solution provided by this invention, by setting the first lens group 1 with negative optical power, facilitates the collection of light by the optical system and achieves a larger field of view; by setting the sixth lens group 6 with positive optical power, it undertakes a larger optical power of the system, changes the propagation direction of the beam, corrects aberrations in the off-axis field of view, and is more conducive to the beam forming on the image plane; by setting all lenses as glass lenses, aberrations are effectively improved, ensuring no defocusing under high temperature conditions, and the system has good reliability and a longer light exposure lifespan; by reasonably setting the focal length of each lens group to form an anti-long-range structure, the projection ratio is increased, making it easier to achieve a larger magnification. By using fourteen lenses and reasonably setting the optical power and material of each lens, large aperture aberrations and defocusing caused by high temperature are corrected, realizing a zoom projection optical system 1000 with large magnification, large aperture, good thermal stability, and high image quality.

[0065] Furthermore, the zoom projection optical system 1000 also includes an aperture stop a, which is disposed between the sixth lens and the seventh lens 51. The aperture stop a limits the light beam aperture along the optical axis, blocking some light rays, thereby reducing light spots, improving image contrast, and enhancing image quality. It should be noted that in this design, the distance between the aperture stop a and the seventh lens 51 is greater than 1mm, and the distance between them is fixed, thus providing installation space for the variable aperture.

[0066] Furthermore, the second lens 12 and the ninth lens 53 are aspherical lenses, while the first lens 11, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 51, the eighth lens 52, the tenth lens 54, the eleventh lens 55, the twelfth lens 56, the thirteenth lens 57, and the fourteenth lens 61 are spherical lenses. It should be noted that the characteristic of aspherical lenses is that their curvature changes continuously from the lens center to the lens periphery, unlike spherical lenses which have a constant curvature from the lens center to the lens periphery. By appropriately setting aspherical lenses, it is beneficial to eliminate aberrations and improve the image quality of the lens.

[0067] Furthermore, to improve the image quality of the optical system, reduce light energy loss, increase imaging clarity, protect the scale surface, and further optimize the manufacturing process to meet design requirements, the seventh lens 51 and the eighth lens 52 are cemented together, and the tenth lens 54, the eleventh lens 55, and the twelfth lens 56 are cemented together. In this way, the reasonable use of cemented components and the reasonable allocation of optical power effectively correct aberrations and achieve a high-temperature, heat-free effect. It also effectively reduces chromatic aberration and improves imaging clarity.

[0068] Specifically, in a preferred embodiment, please refer to Figure 1 The first lens 11 is a concave-convex lens with a convex object-side surface; the second lens 12 is a concave-convex lens with a convex object-side surface; the third lens 13 is a biconcave lens; the fourth lens 21 is a concave-convex lens with a concave object-side surface; the fifth lens 31 is a biconvex lens; the sixth lens 41 is a biconvex lens; the seventh lens 51 is a concave-convex lens with a concave object-side surface; the eighth lens 52 is a biconcave lens; the ninth lens 53 is a biconvex lens; the tenth lens 54 is a concave-convex lens with a convex object-side surface; the eleventh lens 55 is a biconvex lens; the twelfth lens 56 is a concave-convex lens with a concave object-side surface; the thirteenth lens 57 is a concave-convex lens with a concave object-side surface; and the fourteenth lens 61 has a convex object-side surface and a flat image-side surface.

[0069] Further, the focal length of the first lens group 1 is F1, the focal length of the second lens group 2 is F2, the focal length of the third lens group 3 is F3, the focal length of the fourth lens group 4 is F4, the focal length of the fifth lens group 5 is F5, the focal length of the sixth lens group 6 is F6, and the focal length of the zoom projection optical system 1000 at the wide-angle end is f, wherein: -20mm < F1 < -8mm, 50mm < F2 < 100mm, 40mm < F3 < 80mm, 35mm < F4 < 75mm, 45mm < F5 < 80mm, 40mm < F6 < 80mm, -2.2 < F1 / f < -0.84, 5.3 < F2 / f < 10.6, 4.2 < F3 / f < 8.5, 3.7 < F4 / f < 8.0, 4.7 < F5 / f < 8.5, 4.2 < F6 / f < 6.4. This embodiment is a preferred embodiment. By reasonably limiting the relationship between each lens group and its focal length with the optical system, the aberrations of the system are corrected and the imaging quality is improved.

[0070] Further, the focal length of the first lens 11 is f1, the focal length of the second lens 12 is f2, the focal length of the third lens 13 is f3, the focal length of the fourth lens 21 is f4, the focal length of the fifth lens 31 is f5, the focal length of the sixth lens 41 is f6, the focal length of the seventh lens 51 is f7, the focal length of the eighth lens 52 is f8, the focal length of the ninth lens 53 is f9, the focal length of the tenth lens 54 is f10, the focal length of the eleventh lens 55 is f11, the focal length of the twelfth lens 56 is f12, the focal length of the thirteenth lens 57 is f13, and the focal length of the fourteenth lens 11 is f1. The focal length of lens 61 is f14, where: -80mm < f1 < -50mm, -60mm < f2 < -30mm, -60mm < f3 < -30mm, 50mm < f4 < 100mm, 40mm < f5 < 80mm, 35mm < f6 < 75mm, 30mm < f7 < 60mm, -30mm < f8 < -10mm, 20mm < f9 < 40mm, -50mm < f10 < -20mm, 10mm < f11 < 30mm, -50mm < f12 < -20mm, 10mm < f13 < 60mm, 20mm < f14 < 50mm. This embodiment is a preferred embodiment. By combining different lenses and rationally allocating their optical power, the aberrations of the system are corrected, and the image quality is improved.

[0071] Furthermore, the temperature coefficient of refractive index of the ninth lens 53 in the range of 60℃ to 80℃ is dn9 / dt, the temperature coefficient of refractive index of the tenth lens 54 in the range of 60℃ to 80℃ is dn10 / dt, the temperature coefficient of refractive index of the eleventh lens 55 in the range of 60℃ to 80℃ is dn11 / dt, and the temperature coefficient of refractive index of the twelfth lens 56 in the range of 60℃ to 80℃ is dn12 / dt, wherein: 3.1×10 -6 / ℃<dn9 / dt<6×10 -6 / ℃, 0<dn10 / dt<3×10 -6 / ℃,-9×10 -6 / ℃<dn11 / dt<-5×10 -6 / ℃, 3×10 -6 / ℃<dn12 / dt<7×10 -6 / ℃. This setting, by reasonably limiting the temperature coefficient of the lens's refractive index, reduces the impact of temperature on the optical system's performance, thus ensuring that the lens remains in focus even when the aperture is stopped down to F-number 5.

[0072] In one embodiment of the present invention, the diameter of the first lens 11 is D1, and the image plane diameter of the zoom projection optical system 1000 is IC, wherein D1 < 44 mm and IC ≤ 16 mm. This design, by limiting the numerical relationships of the aforementioned optical system characteristics, avoids excessively large apertures in the zoom projection optical system 1000, thus meeting the installation space requirements of the final product.

[0073] It is worth mentioning that the surface shape of the aspherical lens in the zoom projection optical system 1000 described in this embodiment should satisfy the following equation:

[0074]

[0075] Where c is the curvature corresponding to the radius; y is the radial coordinate (its unit is the same as the lens length unit); k is the conic conic section coefficient, and A, B, C, D, E, F, G... represent the fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth... aspherical coefficients, respectively. These parameters allow the setting of the shape and size of the aspherical surfaces facing the object and image sides of the lens.

[0076] Specifically, when k < -1, the corresponding lens surface curve is a hyperbola; when k = -1, the corresponding lens surface curve is a parabola; when -1 < k < 0, the corresponding lens surface curve is an ellipse; when k = 0, the corresponding lens surface curve is a circle; and when k > 0, the corresponding lens surface curve is an oval.

[0077] It should be noted that, in one embodiment of the present invention, the basic parameters of the zoom projection optical system 1000 at the wide-angle end are shown in Table 1, where the units of radius of curvature and thickness are millimeters (mm).

[0078] Table 1

[0079]

[0080]

[0081] In this embodiment, the aspherical coefficients of the aspherical lens in the zoom projection optical system 1000 include: the quadratic surface coefficient k, the fourth-order aspherical coefficient A, the sixth-order aspherical coefficient B, the eighth-order aspherical coefficient C, the tenth-order aspherical coefficient D, the twelfth-order aspherical coefficient E, the fourteenth-order aspherical coefficient F, and the sixteenth-order aspherical coefficient G, as shown in Table 2 below.

[0082] Table 2

[0083]

[0084] With the wide-angle end as the zero point, Table 3 below shows the distances moved by the four zoom groups, in mm. Negative values ​​represent movement towards the object plane, and positive values ​​represent movement towards the image plane.

[0085] Table 3

[0086]

[0087] Please refer to Figure 3 This is a schematic diagram of the spot (SPOT) of the zoom projection optical system 1000 at the wide-angle end in this embodiment. It shows the spot imaging of three different wavelengths of light on the screen under a certain field of view, under normalized different field-of-view conditions. Figure 3 It can be seen that the image points of this optical system are small and the colors are more concentrated at different field positions, indicating that the imaging quality is good.

[0088] Please refer to Figure 4 This is a schematic diagram of the MTF of the zoom projection optical system 1000 at the wide-angle end and with an aperture value of 5 in this embodiment. At this time, the aperture a will receive a large amount of light emitted from the optical engine, and the temperature of the fifth lens group 5 will reach more than 120°C. It shows the imaging quality of three wavelengths of light, where the horizontal axis represents the number of line pairs and the vertical axis represents the resolution capability. The higher the value of the vertical axis, the stronger the resolution capability and the higher the image quality reproduction. The MTF values ​​are all greater than 0.65, indicating that the imaging quality is very clear.

[0089] Please refer to Figure 5This is a schematic diagram of the MTF of the zoom projection optical system 1000 at the wide-angle end in this embodiment. It shows the imaging quality of three wavelengths of light. The horizontal axis represents the number of line pairs, and the vertical axis represents the resolution capability. The higher the value of the vertical axis, the stronger the resolution capability and the higher the image quality reproduction. The MTF values ​​are all greater than 0.55, indicating that the imaging quality is very clear.

[0090] Please refer to Figure 6 This is a schematic diagram of the spot (SPOT) at the telephoto end of the zoom projection optical system 1000 in this embodiment. It shows the spot imaging of three different wavelengths of light on the screen under different normalized field-of-view conditions. Figure 6 It can be seen that the image points of this optical system are small and the colors are more concentrated at different field positions, indicating that the imaging quality is good.

[0091] Please refer to Figure 7 This is a schematic diagram of the MTF of the zoom projection optical system 1000 at the telescope end in this embodiment. It shows the imaging quality of three wavelengths of light. The horizontal axis represents the number of line pairs, and the vertical axis represents the resolution capability. The higher the value of the vertical axis, the stronger the resolution capability and the higher the image quality reproduction. The MTF values ​​are all greater than 0.7, indicating that the imaging quality is very clear.

[0092] In this embodiment, the zoom projection optical system 1000 has a focal length of 9.42mm at the wide-angle end, an aperture of 1.88, an image plane diameter of 16mm, and a zoom ratio of 1.66x. This ensures that various aberrations of the lens are corrected, improves edge image quality, results in high image quality, has excellent thermal stability, and exhibits minimal thermal defocusing at a brightness of 4000lm-5000lm, making its working performance more stable.

[0093] The present invention also proposes a projection device, which includes the zoom projection optical system 1000 described above. Since the projection device includes the zoom projection optical system 1000, the specific structure of which is described in the above embodiments is as described. As the zoom projection optical system 1000 of this projection device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0094] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A zoom projection optical system, characterized in that, The zoom projection optical system has an object side and an image side arranged opposite to each other along the optical axis. The zoom projection optical system consists of a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with positive optical power, a fourth lens group with positive optical power, a fifth lens group with positive optical power, a sixth lens group with positive optical power, a galvanometer, a prism, a protective glass, and a light-emitting chip, arranged sequentially from the object side to the image side. The second, third, fourth, and fifth lens groups are movable along the optical axis to zoom the zoom projection optical system. The first lens group moves in coordination along the optical axis to focus the zoom projection optical system. The sixth lens group is fixed. The first lens group consists of a first lens with negative optical power, a second lens with negative optical power, and a third lens with negative optical power arranged sequentially from the object side to the image side; The second lens group consists of a fourth lens with positive optical power; The third lens group consists of a fifth lens with positive optical power; The fourth lens group consists of a sixth lens with positive optical power; The fifth lens group consists of a seventh lens with positive optical power, an eighth lens with negative optical power, a ninth lens with positive optical power, a tenth lens with negative optical power, an eleventh lens with positive optical power, a twelfth lens with negative optical power, and a thirteenth lens with positive optical power, arranged sequentially from the object side to the image side. The sixth lens group consists of a fourteenth lens with positive optical power; The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens, the thirteenth lens, and the fourteenth lens are all glass lenses; The focal length of the first lens group is F1, the focal length of the second lens group is F2, the focal length of the third lens group is F3, the focal length of the fourth lens group is F4, the focal length of the fifth lens group is F5, the focal length of the sixth lens group is F6, and the focal length of the zoom projection optical system at the wide-angle end is f, wherein: -20mm<F1<-8mm, 50mm<F2<100mm, 40mm<F3<80mm, 35mm<F4<75mm, 45mm<F5<80mm, 40mm<F6<80mm, - 2.2<F1 / f<-0.84, 5.3<F2 / f<10.6, 4.2<F3 / f<8.5, 3.7<F4 / f<8.0, 4.7<F5 / f<8.5, 4.2<F6 / f<6.4; The focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, the focal length of the eighth lens is f8, the focal length of the ninth lens is f9, the focal length of the tenth lens is f10, the focal length of the eleventh lens is f11, the focal length of the twelfth lens is f12, the focal length of the thirteenth lens is f13, and the focal length of the fourteenth lens is f14, wherein: -80mm<f1<-50mm, -60mm<f2<-30mm, -60mm<f3<-30mm, 50mm<f4<100mm, 40mm<f5<80mm, 35mm<f6<75mm, 30mm<f7<60mm, -3 0mm<f8<-10mm, 20mm<f9<40mm, -50mm<f10<-20mm, 10mm<f11<30mm, -50mm<f12<-20mm, 10mm<f13<60mm, 20mm<f14<50mm.

2. The zoom projection optical system as described in claim 1, characterized in that, The zoom projection optical system also includes an aperture stop, which is disposed between the sixth lens and the seventh lens.

3. The zoom projection optical system as described in claim 1, characterized in that, The second and ninth lenses are aspherical lenses, while the first, third, fourth, fifth, sixth, seventh, eighth, tenth, eleventh, twelfth, thirteenth, and fourteenth lenses are spherical lenses.

4. The zoom projection optical system as described in claim 1, characterized in that, The seventh lens is cemented to the eighth lens, and the tenth lens, eleventh lens, and twelfth lens are cemented to each other.

5. The zoom projection optical system as described in claim 1, characterized in that, The first lens is a concave-convex lens, and its object-side surface is convex. The second lens is a concave-convex lens, and its object-side surface is convex. The third lens is a biconcave lens; The fourth lens is a concave-convex lens, and its object-side surface is concave. The fifth lens is a biconvex lens; The sixth lens is a biconvex lens; The seventh lens is a concave-convex lens, and its object-side surface is concave. The eighth lens is a biconcave lens; The ninth lens is a biconvex lens; The tenth lens is a concave-convex lens, and its object-side surface is convex. The eleventh lens is a biconvex lens; The twelfth lens is a concave-convex lens, and its object-side surface is concave. The thirteenth lens is a concave-convex lens, and its object-side surface is concave. The object-side surface of the fourteenth lens is convex, and the image-side surface is planar.

6. The zoom projection optical system as described in claim 5, characterized in that, The temperature coefficient of refractive index of the ninth lens in the range of 60℃ to 80℃ is dn9 / dt, the temperature coefficient of refractive index of the tenth lens in the range of 60℃ to 80℃ is dn10 / dt, the temperature coefficient of refractive index of the eleventh lens in the range of 60℃ to 80℃ is dn11 / dt, and the temperature coefficient of refractive index of the twelfth lens in the range of 60℃ to 80℃ is dn12 / dt, wherein: 3.1×10 -6 / ℃<dn9 / dt<6×10 -6 / ℃,0<dn10 / dt<3×10 -6 / ℃,-9×10 -6 / ℃<dn11 / dt<-5×10 -6 / ℃,3×10 -6 / ℃<dn12 / dt<7×10 -6 / ℃。 7. The zoom projection optical system as described in claim 1, characterized in that, The diameter of the first lens is D1, and the diameter of the image plane of the zoom projection optical system is IC, wherein: D1 < 44 mm, IC ≤ 16 mm.

8. A projection device, characterized in that, Includes the zoom projection optical system as described in any one of claims 1 to 7.

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