Long-focus large-zoom projection optical system and projection equipment

Abstract

The invention relates to the technical field of optical imaging, and discloses a long-focus large-zoom projection optical system and projection equipment. The optical system is sequentially provided with eleven lenses from the object side to the image side, wherein the eleven lenses are coaxially arranged and sequentially comprise 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 and the eleventh lens from the object side to the image side. An aperture diaphragm is arranged between the sixth lens and the seventh lens; the focal powers of the lenses from the object side to the image side are negative, negative, negative, positive, positive, positive, positive, negative, positive, positive and positive in sequence; the first lens and the second lens are plastic aspheric lenses, the eleventh lens is a glass aspheric lens, the rest lenses are spherical lenses, the third lens and the fourth lens are connected in a gluing mode, and the seventh lens, the eighth lens and the ninth lens are connected in a gluing mode. According to the invention, the focal power of each lens is set, and the range of the focal power is ensured to be large, so that a large focal length variation range is achieved, and the larger the focal length range is, the higher the zoom ratio is.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to a long-focus large-magnification projection optical system and a projection device. Background Art

[0002] At present, projection display has been gradually applied to various fields such as education, family, military, transportation, office, etc. The projection display market is vast, but the lens, as one of the core technologies in projection display, is difficult to design and process. The focal length of telephoto projection lenses in the existing technology can be changed in a relatively small range and cannot meet actual needs; for those with a large zoom range, it is impossible to take into account the cost, resolution, temperature and defocus at the same time, which greatly affects the use effect of consumers.

[0003] Therefore, there is an urgent need to develop a long-focus, large-magnification projection optical system to solve the above problems. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a long-focus large-zoom projection optical system and a projection device, and provides a long-focus projection optical system that can provide high definition and a large zoom ratio under different conditions.

[0005] In a first aspect, a first object of the present invention is to provide a long focal length large zoom projection optical system, comprising: The optical system is provided with eleven lenses arranged coaxially from the object side to the image side: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens from the object side to the image side; an aperture stop is provided between the sixth lens and the seventh lens; The optical power of each lens from the object side to the image side is: negative, negative, negative, positive, positive, positive, positive, positive, negative, positive, positive, positive, positive; among them, The first lens and the second lens are plastic aspheric lenses, the eleventh lens is a glass aspheric lens, and the remaining lenses are spherical lenses. The third lens and the fourth lens are glued together, and the seventh lens, the eighth lens and the ninth lens are glued together.

[0006] Further, the first lens is a concave-convex lens, and the object-side surface of the first lens is a convex surface; The second lens is a biconcave lens; The third lens is a biconcave lens; The fourth lens is a biconvex lens, and the object side surface of the fourth lens is a convex surface; The fifth lens is a concave-convex lens, and the object side surface of the fifth lens is a convex surface; The sixth lens is a meniscus lens, and the object side surface of the sixth lens is a concave surface; The seventh lens is a meniscus lens, and the object side surface of the seventh lens is a convex surface; The eighth lens is a biconcave lens; The ninth lens is a biconvex lens; The tenth lens is a biconvex lens; The eleventh lens is a biconvex lens.

[0007] Furthermore, the focal lengths of the lenses from the object side to the image side are f1, f2, f3, f4, f5, f6, f7, f8, f9, f 10 and f 11 ,in: -30<f1<28, -75<f2<-72, -35<f3<39, 39<f4<45, 500<f 5<550, 37<f6<40, 25<f7<30, -8<f8<-9, 18<f9<22, 50<f 10 <55,38<f 11 <45.

[0008] Furthermore, the refractive indexes of the lenses from the object side to the image side are n1, n2, n3, n4, n5, n6, n7, n8, n9, n10, n11, n12, n13, n14, n15, n16, n17, n18, n19, n20, n30, n4, n5, n6, n7, n8, n9, n10, n11, n12, n1 10 and n 11 ; 1.40≤n1≤1.60, 1.40≤n2≤1.60, 1.70≤n3≤1.90, 1.60≤n4≤2.00, 1.50≤n5≤1.70, 1.60≤n6≤1.80, 1.50≤n7≤1.70, 1.70≤n8≤1.90, 1.70≤n9≤1.80,1.40≤n 10 ≤1.60, 1.8≤n 11 ≤2.0.

[0009] Furthermore, the dispersion coefficients of the lenses from the object side to the image side are v1, v2, v3, v4, v5, v6, v7, v8, v9, v 10 and v 11 ;in: 50.0≤v1≤70.0, 50.0≤v2≤70.0, 30.0≤v3≤60.0, 20.0≤v4≤40.0, 40.0≤v5≤70.0, 30.0≤v6≤60.0, 20.0≤v7≤60.0, 20.0≤v8≤40.0, 50.0≤v9≤70.0,50.0≤v 10 ≤70.0,10.0≤v 11≤30.0.

[0010] Furthermore, an image biasing mirror, an illumination prism and a light valve are sequentially arranged on the image side of the eleventh lens.

[0011] In a second aspect, a second object of the present invention is to provide a projection device, comprising a long-focus and large-magnification projection optical system as described in the first aspect.

[0012] The embodiments of the present invention have the following technical effects: The present application sets eleven lenses, and by setting the optical focal length of each lens, a larger range of optical focal length is ensured, thereby having a larger focal length variation range. The larger the focal length range, the higher the zoom ratio, achieving a projection frame within the range of 50 inches to 120 inches; The present application also improves the aberration to the greatest extent through the setting of the bonding parts and the shapes of each lens, ensuring that there is no false focus at high temperature; the focal length, refractive index, dispersion coefficient, etc. of each lens are precisely designed to further ensure the ability of the optical system to deflect light; This application achieves a large zoom under long focal length conditions, thereby increasing the application scenarios and is more suitable for application scenarios that require long-distance projection and high magnification, such as large conference rooms, classrooms, theaters, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a structural schematic diagram of a long-focus large-zoom projection optical system provided by an embodiment of the present invention; Figure 2 : is a schematic diagram of TV distortion provided by an embodiment of the present invention. In the left coordinate system, the horizontal coordinate represents the magnitude of field curvature, in units of mm, and the vertical coordinate represents the normalized image height; in the right coordinate system, the horizontal coordinate represents the magnitude of distortion, in units of %, and the vertical coordinate represents the normalized image height; Figure 3 is a diagram of light spots under different field of view conditions on an imaging screen provided by an embodiment of the present invention; Figure 4is a light fan diagram provided by an embodiment of the present invention; the 10 diagrams respectively represent 10 normalized fields of view, and the two diagrams in each field of view respectively represent the aberrations in the x-axis direction and the y-axis direction symmetrical with the optical axis as the center of the optical system; the horizontal axis direction in each diagram is the pupil height position under the field of view condition, and the vertical axis direction is the error between each wavelength of light and the main light; In the figure, 1 is the first lens; 2 is the second lens; 3 is the third lens; 4 is the fourth lens; 5 is the fifth lens; 6 is the sixth lens; 7 is the seventh lens; 8 is the eighth lens; 9 is the ninth lens; 10 is the tenth lens; 11 is the eleventh lens; 12 is the aperture stop; 13 is the image biasing mirror; 14 is the prism; 15 is the light valve. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0016] Example 1

[0017] First of all, it is explained that the image biasing filter is a polarizing filter or a polarizing filter, which is used to improve the resolution. The resolution is improved by the vibration of the galvanometer.

[0018] Zoom refers to the ability of a lens to change its focal length, usually expressed as a zoom factor, which refers to the ratio of the longest focal length to the shortest focal length of a zoom lens. Telephoto and high-zoom lenses usually have a higher zoom factor, which can achieve clear monitoring and detail capture of distant targets.

[0019] Figure 1 Schematic diagram of a long focal length and large zoom projection optical system provided by an embodiment of the present invention. Figure 1 The optical system is provided with eleven lenses arranged coaxially from the object side to the image side: from the object side to the image side, they are a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10 and an eleventh lens 11; an aperture stop 12 is provided between the sixth lens 6 and the seventh lens 7; the setting of the aperture stop 12 can control the amount of light entering the rear lens, adjust the depth of field and the aperture size, and avoid affecting the clarity of the image.

[0020] The focal powers of the lenses from the object side to the image side are: negative, negative, negative, positive, positive, positive, positive, negative, positive, positive, positive; the focal power determines the convergence and divergence of the optical system on the light beam, and the range of variation of the focal power determines the range of focal length variation that the zoom system can achieve. The larger the range of variation of the focal power, the larger the zoom range that the zoom system can achieve, that is, it has a high zoom ratio; The present application ensures a large optical power range through the coordinated design of optical power, thereby achieving a large zoom, and the projection frame can reach 50 inches to 120 inches, while the existing optical system projection frame is 50 to 100 inches.

[0021] Specifically, the first lens 1 and the second lens 2 are plastic aspheric lenses, which can control light more accurately, improve optical performance, improve imaging quality, and reduce aberrations. Plastic aspheric lenses have relatively low manufacturing costs and are easy to mass produce.

[0022] The eleventh lens 11 is a glass aspherical lens, and the other lenses are spherical lenses. The glass aspherical lens ensures that the light is focused more accurately, reduces optical aberrations, especially spherical aberrations, provides a clearer view and higher imaging accuracy, and improves the clarity and accuracy of the image.

[0023] Specifically, the third lens 3 and the fourth lens 4 are glued together, and the seventh lens 7, the eighth lens 8 and the ninth lens 9 are glued together. The use of glued lenses effectively corrects chromatic aberration, so that light of different wavelengths is focused at different positions after being refracted by the lenses. By gluing two lenses together, the chromatic aberration of one lens is compensated by the other lens.

[0024] The total optical length of the optical system is kept within 124.126mm, making the structure relatively compact, and the definition reaches above 1080, which can provide clear and delicate image quality. The aperture value is between 2.0 and 2.5, so that clear imaging can be achieved even in weak light; In summary, by adopting eleven lenses and further setting the optical focal length and shape of each lens, the lenses cooperate with each other to realize a large-magnification projection system, and by setting bonding parts, aberrations are corrected, the purpose of not out of focus at high temperature is achieved, and the imaging quality is guaranteed.

[0025] In a preferred embodiment, the first lens 1 is a concave-convex lens, and the object-side surface of the first lens 1 is convex; the second lens 2 is a biconcave lens; the third lens 3 is a biconcave lens; the fourth lens 4 is a biconvex lens, and the object-side surface of the fourth lens 4 is convex; the fifth lens 5 is a concave-convex lens, and the object-side surface of the fifth lens 5 is convex; the sixth lens 6 is a concave-convex lens, and the object-side surface of the sixth lens 6 is concave; the seventh lens 7 is a concave-convex lens, and the object-side surface of the seventh lens 7 is convex; the eighth lens 8 is a biconcave lens; the ninth lens 9 is a biconvex lens; the tenth lens 10 is a biconvex lens; and the eleventh lens 11 is a biconvex lens.

[0026] Detailed settings for focal length and refractive index are made to further ensure the optical system's ability to deflect light: The focal lengths of the lenses from the object side to the image side are f1, f2, f3, f4, f5, f6, f7, f8, f9, f 10 and f 11 ,in: -30<f1<28, -75<f2<-72, -35<f3<39, 39<f4<45, 500<f 5<550, 37<f6<40, 25<f7<30, -8<f8<-9, 18<f9<22, 50<f 10 <55,38<f 11 <45. Through the cooperation of different focal lengths, the optical system of the present application has high pixel, high definition, high color reproduction, etc.

[0027] The refractive index of each lens from the object side to the image side is n1, n2, n3, n4, n5, n6, n7, n8, n9, n 10 and n 11 ; The dispersion coefficients of the lenses from the object side to the image side are v1, v2, v3, v4, v5, v6, v7, v8, v9, v 10 and v 11 ;in: 1.40≤n1≤1.60, 1.40≤n2≤1.60, 1.70≤n3≤1.90, 1.60≤n4≤2.00, 1.50≤n5≤1.70, 1.60≤n6≤1.80, 1.50≤n7≤1.70, 1.70≤n8≤1.90, 1.70≤n9≤1.80,1.40≤n 10 ≤1.60, 1.8≤n 11 ≤2.0; 50.0≤v1≤70.0, 50.0≤v2≤70.0, 30.0≤v3≤60.0, 20.0≤v4≤40.0, 40.0≤v5≤70.0, 30.0≤v6≤60.0, 20.0≤v7≤60.0, 20.0≤v8≤40.0, 50.0≤v9≤70.0,50.0≤v 10 ≤70.0,10.0≤v 11 ≤30.0.

[0028] In summary, by further rationally allocating the concave and convex surfaces, focal length, refractive index and dispersion coefficient of the lens, the system as a whole has the characteristics of large zoom, low cost, high pixel and good heat elimination.

[0029] The image side of the eleventh lens 11 is provided with an image biasing mirror 13, an illumination prism 14 and a light valve 15 in sequence. The image biasing mirror further improves the imaging resolution, and the light valve is used to control whether the light passes through, so as to adjust the brightness and clarity of the projected image; the illumination prism can change the propagation path of the light to achieve a specific lighting effect and ensure that the light intensity is appropriate; the deflection angle of the illumination prism and the incident angle of the light can be calculated by Snell's law: , Among them, n1 and n2 are the refractive indices of the media at the incident and exit ends, respectively. is the angle of incidence, is the angle of refraction.

[0030] Based on the above technical solution, a long-focus projection optical system with large magnification, high resolution, low cost and no false focus at high and low temperatures is realized.

[0031] Example 2

[0032] Based on the optical system in Example 1, the present application provides a specific embodiment: Three representative light beams with different wavelengths are set, namely 0.465um, 0.525um, and 0.643um, and blue, green, and red are used to represent these three wavelengths, and green light is selected as the main wavelength. The three wavelengths of light are passed through the above optical system respectively, and relevant verification is carried out to obtain the following figure, and relevant analysis is carried out according to the content of the figure: Figure 2 The coordinate system on the left side of the center shows that the difference between the image quality in the center and the periphery during imaging is small, while the coordinate system on the right side shows that the imaging distortion is small, meeting the requirement of low distortion.

[0033] Figure 3The figure shows the schematic diagram of the point spot imaging of three wavelengths of light on the screen under different normalized field of view conditions, where IMA represents the image plane. Figure 3 It shows that under different wavelength conditions, the convergence effect of the light spot is good.

[0034] Figure 4 It shows the aberration value between the x-axis and the y-axis. The aberration under different wavelengths of light is very small.

[0035] In summary, the optical system of the present application has high imaging quality while meeting the requirements of a large zoom range, is not out of focus under high temperature conditions, and has low cost.

[0036] Example 3

[0037] Based on the content of Example 1, the present application provides a projection device based on the optical system in Example 1. For other contents, refer to Example 1, and the present application will not elaborate on them.

[0038] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0039] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A long-focus large-zoom projection optical system, characterized in that: The optical system is provided with eleven lenses arranged coaxially from the object side to the image side: from the object side to the image side, they are a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), a sixth lens (6), a seventh lens (7), an eighth lens (8), a ninth lens (9), a tenth lens (10) and an eleventh lens (11); an aperture stop (12) is provided between the sixth lens (6) and the seventh lens (7); The optical power of each lens from the object side to the image side is: negative, negative, negative, positive, positive, positive, positive, positive, negative, positive, positive, positive, positive; among them, The first lens (1) and the second lens (2) are plastic aspheric lenses, the eleventh lens (11) is a glass aspheric lens, and the remaining lenses are spherical lenses. The third lens (3) and the fourth lens (4) are glued together, and the seventh lens (7), the eighth lens (8) and the ninth lens (9) are glued together.

2. The long focal length and large zoom projection optical system according to claim 1, characterized in that: The first lens (1) is a concave-convex lens, and the object side surface of the first lens (1) is a convex surface; The second lens (2) is a biconcave lens; The third lens (3) is a biconcave lens; The fourth lens (4) is a biconvex lens, and the object side surface of the fourth lens (4) is a convex surface; The fifth lens (5) is a concave-convex lens, and the object-side surface of the fifth lens (5) is a convex surface; The sixth lens (6) is a meniscus lens, and the object side surface of the sixth lens (6) is a concave surface; The seventh lens (7) is a meniscus lens, and the object side surface of the seventh lens (7) is a convex surface; The eighth lens (8) is a biconcave lens; The ninth lens (9) is a biconvex lens; The tenth lens (10) is a biconvex lens; The eleventh lens (11) is a biconvex lens.

3. The long focal length and large zoom projection optical system according to claim 1, characterized in that: The focal lengths of the lenses from the object side to the image side are f1, f2, f3, f4, f5, f6, f7, f8, f9, f 10 and f 11 ,in: <h2 style=";text-align:left;direction:ltr">-30<f1<28,-75<f2<-72,-35<f3<39,39<f4<45,500<f5<550,37<f6<40,25<f7<30,-8<f8<-9,18<f9<22,50<f<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> <55,38<f<h2 style=";text-align:left;direction:ltr"> 11 <h2 style=";text-align:left;direction:ltr"> <45。 4. The long focal length and large zoom projection optical system according to claim 1, characterized in that: The refractive index of each lens from the object side to the image side is n1, n2, n3, n4, n5, n6, n7, n8, n9, n 10 and n 11 ; 1.40≤n1≤1.60, 1.40≤n2≤1.60, 1.70≤n3≤1.90, 1.60≤n4≤2.00, 1.50≤n5≤1.70, 1.60≤n6≤1.80, 1.50≤n7≤1.70, 1.70≤n8≤1.90, 1.70≤n9≤1.80,1.40≤n 10 ≤1.60,1.8≤n 11 ≤2.0。 5. The long focal length and large zoom projection optical system according to claim 1, characterized in that: The dispersion coefficients of the lenses from the object side to the image side are v1, v2, v3, v4, v5, v6, v7, v8, v9, v 10 and v 11 ;in: 50.0≤v1≤70.0, 50.0≤v2≤70.0, 30.0≤v3≤60.0, 20.0≤v4≤40.0, 40.0≤v5≤70.0, 30.0≤v6≤60.0, 20.0≤v7≤60.0, 20.0≤v8≤40.0, 50.0≤v9≤70.0,50.0≤v 10 ≤70.0,10.0≤v 11 ≤30.0。 6. The long focal length and large zoom projection optical system according to claim 1, characterized in that: An image biasing mirror (13), an illumination prism (14) and a light valve (15) are sequentially arranged on the image side of the eleventh lens (11).

7. A projection device, characterized in that: It comprises a long-focus and large-magnification projection optical system as described in any one of claims 1 to 6.

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