Large-aperture low-distortion projection lens

Abstract

The utility model discloses a large-aperture low-distortion projection lens which is composed of a lens barrel, a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens. The two ends of the lens barrel penetrate through each other to form an installation cavity, and the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens and the sixth lens are all arranged in the installation cavity and are sequentially arranged from the image source side to the imaging side along the optical axis. The product is formed by arranging six lenses in a lens cone, the number of the lenses is small, the structure is simple, the focal length (EFL) of the product is 85 mm, the total length (TOTR) is 113.6 mm, the aperture (F number) is 1.8, and the image plane is 52 mm. A use test shows that the maximum field of view of the product is 8.5000 Deg, the distortion after projection imaging of the product is smaller than 1%, the maximum angle of view of the product relative to illumination is larger than 0.9, the large aperture and low distortion are achieved, and the product has a wide application prospect. And the use requirements are completely met.

Description

Technical Field

[0001] The utility model relates to the technology of lens field, in particular to a large aperture low distortion projection lens. Background Art

[0002] The optical imaging system is composed of a group of optical lenses to achieve clear focusing and zooming functions of light source imaging, and the projection angle is controlled between 1° and 5°. Pattern pieces can be added to the lens group to achieve clear projection images of specific patterns. The integrated optical projection system composed of the light source and the optical lens is referred to as "LED projector". The LED projector is arranged in a vertical and horizontal form to form a projection array, which projects the light source imaging (light spot) on the interface to form a light spot array. The light spot array forms grayscale changes under program control to achieve pattern changes. The above systems are collectively referred to as LED projection lamps. The projection interface can be a reflective material, such as the exterior wall of a building, the surface of a sculpture, a mountain, etc., the interior decoration surface, the ground, etc. The projection interface can also be a translucent material, such as an outdoor membrane structure, an interior decorative tensile membrane structure, a translucent stone, an acrylic translucent board, etc.

[0003] The lens is an important part of the projection lamp. Its main structure includes a lens barrel and a lens group. The lens group is arranged in the lens barrel. The lens group is composed of multiple lenses. At present, although the imaging clarity of the lens is high, the number of lenses is very large, the structure is complex, and it is difficult to achieve a large aperture and low distortion, which cannot meet the needs of use. Therefore, it is necessary to improve the current projection lens. Utility Model Content

[0004] In view of this, the present invention aims to address the deficiencies in the prior art, and its main purpose is to provide a large aperture and low distortion projection lens, which can effectively solve the problems of the existing projection lenses having a complex structure and being difficult to achieve a large aperture and low distortion.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A large aperture low distortion projection lens, comprising a lens barrel, a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens; both ends of the lens barrel are penetrated to form a mounting cavity, the first lens, the second lens, the third lens, the aperture, the fourth lens, the fifth lens and the sixth lens are all arranged in the mounting cavity and arranged in sequence from the image source side to the imaging side along the optical axis;

[0007] The front end surface of the first lens is a first convex surface, and the rear end surface of the first lens is a first concave surface;

[0008] The front end surface of the second lens is a second convex surface, and the rear end surface of the second lens is a second concave surface;

[0009] The front end surface of the third lens is a third convex surface, and the rear end surface of the third lens is a third concave surface;

[0010] The front end surface of the fourth lens is a fourth concave surface, and the rear end surface of the fourth lens is a fifth concave surface;

[0011] The front end surface of the fifth lens is a sixth concave surface, and the rear end surface of the fifth lens is a fourth convex surface;

[0012] The front end surface of the sixth lens is a fifth convex surface, and the rear end surface of the sixth lens is a sixth convex surface.

[0013] As a preferred solution, the lens barrel is an integrated structure, a retaining ring is convexly provided on the inner edge of the front end of the lens barrel, a limiting ring is convexly provided on the inner edge of the rear end of the lens barrel, and a first positioning ring, a second positioning ring, a third positioning ring, a fourth positioning ring, a fifth positioning ring and a sixth positioning ring are arranged in the mounting cavity; the first positioning ring cooperates with the retaining ring to be positioned by snap-fitting, the first positioning ring abuts against the periphery of the front end surface of the first lens, the second positioning ring is clamped between the first lens and the second lens, the third positioning ring is clamped between the second lens and the third lens, the fourth positioning ring is clamped between the third lens and the fourth lens, the fifth positioning ring is clamped between the fourth lens and the fifth lens, the sixth positioning ring is clamped between the fifth lens and the sixth lens, and the periphery of the rear end surface of the sixth lens abuts against the front end surface of the limiting ring, the structure is simple, and the assembly is convenient.

[0014] As a preferred solution, the outer periphery of the aperture is fitted and fixed to the inner periphery of the fourth positioning ring, so that the assembly is simple and stable.

[0015] As a preferred solution, the front end of the lens barrel is in a trumpet shape, and the rear end of the lens barrel is in a multi-section cylindrical shape.

[0016] As a preferred solution, the lens barrel is made of plastic, and the first positioning ring, the second positioning ring, the third positioning ring, the fourth positioning ring, the fifth positioning ring and the sixth positioning ring are all made of aluminum alloy, with good structural strength.

[0017] Compared with the prior art, the utility model has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that:

[0018] This product is composed of six lenses arranged in a lens barrel, with a small number of lenses and a simple structure. The focal length (EFL) of this product is 85mm, the total length (TOTR) is 113.6mm, the aperture (F number) is 1.8, and the image plane is 52mm. After use testing, the maximum field of view of this product is 8.5000Deg, the distortion of this product after projection imaging is less than 1%, and the maximum viewing angle of relative illumination of this product is greater than 0.9, achieving large aperture and low distortion, which fully meets the needs of use.

[0019] In order to more clearly illustrate the structural features and functions of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of an assembly perspective view of a preferred embodiment of the utility model;

[0021] Figure 2 It is a three-dimensional schematic diagram of the assembly of the preferred embodiment of the utility model from another angle;

[0022] Figure 3 It is an exploded view of a preferred embodiment of the utility model;

[0023] Figure 4 It is an exploded view from another angle of the preferred embodiment of the utility model;

[0024] Figure 5 It is a cross-sectional view of a preferred embodiment of the utility model;

[0025] Figure 6 It is a side view of vertical axis chromatic aberration in a preferred embodiment of the utility model;

[0026] Figure 7 It is a distorted side view of a preferred embodiment of the utility model;

[0027] Figure 8 It is a side view of the relative illumination in the preferred embodiment of the utility model.

[0028] Description of the accompanying drawings:

[0029] 10. Lens tube 11. Mounting cavity

[0030] 12. Snap ring 13. Limit ring

[0031] 21. first lens 211. first convex surface

[0032] 212, first concave surface 22, second lens

[0033] 221, second convex surface 222, second concave surface

[0034] 23. Third lens 231. Third convex surface

[0035] 232, third concave surface 24, aperture

[0036] 25. Fourth lens 251. Fourth concave surface

[0037] 252, fifth concave surface 26, fifth lens

[0038] 261, sixth concave surface 262, fourth convex surface

[0039] 27. Sixth lens 271. Fifth convex surface

[0040] 272, sixth convex surface 31, first positioning ring

[0041] 32. Second positioning ring 33. Third positioning ring

[0042] 34. Fourth positioning ring 35. Fifth positioning ring

[0043] 36. Sixth positioning ring. DETAILED DESCRIPTION

[0044] Please refer to Figures 1 to 5 As shown, it shows the specific structure of a preferred embodiment of the utility model, which is composed of a lens barrel 10, a first lens 21, a second lens 22, a third lens 23, an aperture 24, a fourth lens 25, a fifth lens 26 and a sixth lens 27.

[0045] Both ends of the lens barrel 10 are penetrated to form a mounting cavity 11. In the present embodiment, the lens barrel 10 is an integrated structure. A retaining ring 12 is convexly provided on the inner edge of the front end of the lens barrel 10, and a limiting ring 13 is convexly provided on the inner edge of the rear end of the lens barrel 10. The front end of the lens barrel 10 is horn-shaped, and the rear end of the lens barrel 10 is multi-section cylindrical. The lens barrel 10 is made of plastic, has a simple structure, and is easy to manufacture.

[0046] The first lens 21, the second lens 22, the third lens 23, the aperture 24, the fourth lens 25, the fifth lens 26 and the sixth lens 27 are all arranged in the mounting cavity 11 and arranged in sequence from the image source side to the imaging side along the optical axis; the front end face of the first lens 21 is a first convex surface 211, and the rear end face of the first lens 21 is a first concave surface 212; the front end face of the second lens 22 is a second convex surface 221, and the rear end face of the second lens 22 is a second concave surface 222; The front end face of the third lens 23 is a third convex surface 231, and the rear end face of the third lens 23 is a third concave surface 232; the front end face of the fourth lens 25 is a fourth concave surface 251, and the rear end face of the fourth lens 25 is a fifth concave surface 252; the front end face of the fifth lens 26 is a sixth concave surface 261, and the rear end face of the fifth lens 26 is a fourth convex surface 262; the front end face of the sixth lens 27 is a fifth convex surface 271, and the rear end face of the sixth lens 27 is a sixth convex surface 272.

[0047] In this embodiment, the refractive index of the first lens 21 is 1.6385, the Abbe number of the first lens 21 is 55.45, the curvature radius of the first convex surface 211 is 75.234 mm, the thickness of the first convex surface 211 is 9.56 mm, the curvature radius of the first concave surface 212 is -1681 mm, and the thickness of the first concave surface 212 is 0.7 mm; the refractive index of the second lens 22 is 1.6204, the Abbe number of the second lens 22 is 60.34, the curvature radius of the second convex surface 221 is 38.245 mm, and the thickness of the second convex surface 22 The thickness of the second concave surface 222 is 12.85 mm, the radius of curvature of the second concave surface 222 is -118.87 mm, and the thickness of the second concave surface 222 is 1.43 mm; the refractive index of the third lens 23 is 1.647769, the Abbe number of the third lens 23 is 33.84, the radius of curvature of the third convex surface 231 is 220.187 mm, and the thickness of the third convex surface 231 is 4.39 mm, the radius of curvature of the third concave surface 232 is -29.462 mm, and the thickness of the third concave surface 232 is 6.33 mm; the radius of curvature of the aperture 24 is 6 8.947mm, the thickness of the aperture 24 is 4.22; the refractive index of the fourth lens 25 is 1.64769mm, the Abbe number of the fourth lens 25 is 33.84, the curvature radius of the fourth concave surface 251 is -41.775mm, the thickness of the fourth concave surface 251 is 2.5mm, the curvature radius of the fifth concave surface 252 is -148.91mm, and the thickness of the fifth concave surface 252 is 2.98mm; the refractive index of the fifth lens 26 is 1.6204, the Abbe number of the fifth lens 26 is 60.34, and the curvature radius of the sixth concave surface 261 is -148.91mm, and the thickness of the fifth concave surface 252 is 2.98mm; The radius of curvature is -271.5mm, the thickness of the sixth concave surface 261 is 7.82mm, the radius of curvature of the fourth convex surface 262 is 39.55mm, and the thickness of the fourth convex surface 262 is 0.7mm; the refractive index of the sixth lens 27 is 1.6385, the Abbe number of the sixth lens 27 is 55.45, the radius of curvature of the fifth convex surface 271 is 64.478mm, and the thickness of the fifth convex surface 271 is 8.94mm, the radius of curvature of the sixth convex surface 272 is 238.86mm, and the thickness of the sixth convex surface 272 is 1.16mm.

[0048] Furthermore, the installation cavity 11 is provided with a first positioning ring 31, a second positioning ring 32, a third positioning ring 33, a fourth positioning ring 34, a fifth positioning ring 35 and a sixth positioning ring 36. The first positioning ring 31 is positioned by buckling with the snap ring 12, the first positioning ring 31 is against the periphery of the front end surface of the first lens 21, the second positioning ring 32 is sandwiched between the first lens 21 and the second lens 22, the third positioning ring 33 is sandwiched between the second lens 22 and the third lens 23, the fourth positioning ring clamp 34 is sandwiched between the third lens 23 and the fourth lens 25, the fifth positioning ring 35 is sandwiched between the fourth lens 25 and the fifth lens 26, the sixth positioning ring 36 is sandwiched between the fifth lens 26 and the sixth lens 27, and the periphery of the rear end surface of the sixth lens 27 is against the front end surface of the limit ring 13, the structure is simple, and the assembly is convenient. The outer periphery of the aperture 24 is fixedly attached to the inner periphery of the fourth positioning ring 34, and the assembly is simple and stable. In addition, the first positioning ring 31 , the second positioning ring 32 , the third positioning ring 33 , the fourth positioning ring 34 , the fifth positioning ring 35 and the sixth positioning ring 36 are all made of aluminum alloy and have good structural strength.

[0049] The assembly process of this embodiment is described in detail as follows:

[0050] During assembly, first, the diaphragm 24 is fixed on the fourth positioning ring 34, and then the sixth lens 27, the sixth positioning ring 36, the fifth lens 26, the fifth positioning ring 35, the fourth lens 25, the fourth positioning ring 34, the third lens 23, the third positioning ring 33, the second lens 22, the second positioning ring 32, the first lens 21 and the first positioning ring 31 are sequentially installed into the installation cavity 11 from the front end opening of the installation cavity 11 from front to back. After being installed in place, the sixth lens 27 abuts against the limiting ring 13, and the first positioning ring 31 cooperates with the snap ring 12 to be positioned. At this time, the sixth lens 27, the sixth positioning ring 36, the fifth lens 26, the fifth positioning ring 35, the fourth lens 25, the fourth positioning ring 34, the third lens 23, the third positioning ring 33, the second lens 22, the second positioning ring 32 and the first lens 21 are clamped between the limiting ring 13 and the snap ring 12, thereby achieving assembly.

[0051] The focal length (EFL) of this product is 85mm, the total length (TOTR) is 113.6mm, the aperture (F number) is 1.8, and the image plane is 52mm. After use and testing, Figure 6 As shown, the maximum field of view of this product is 8.5000Deg. Figure 7 As shown in the figure, the distortion of the projected image of this product is less than 1%. Figure 8 As shown, the maximum viewing angle of the relative illumination of this product is greater than 0.9.

[0052] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A large aperture low distortion projection lens, characterized in that: The lens barrel is composed of a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens; both ends of the lens barrel are penetrated to form a mounting cavity, and the first lens, the second lens, the third lens, the aperture, the fourth lens, the fifth lens and the sixth lens are all arranged in the mounting cavity and arranged in sequence from the image source side to the imaging side along the optical axis; The front end surface of the first lens is a first convex surface, and the rear end surface of the first lens is a first concave surface; The front end surface of the second lens is a second convex surface, and the rear end surface of the second lens is a second concave surface; The front end surface of the third lens is a third convex surface, and the rear end surface of the third lens is a third concave surface; The front end surface of the fourth lens is a fourth concave surface, and the rear end surface of the fourth lens is a fifth concave surface; The front end surface of the fifth lens is a sixth concave surface, and the rear end surface of the fifth lens is a fourth convex surface; The front end surface of the sixth lens is a fifth convex surface, and the rear end surface of the sixth lens is a sixth convex surface.

2. The large aperture low distortion projection lens according to claim 1, characterized in that: The lens barrel is an integrated structure, a retaining ring is convexly provided on the inner edge of the front end of the lens barrel, a limiting ring is convexly provided on the inner edge of the rear end of the lens barrel, and a first positioning ring, a second positioning ring, a third positioning ring, a fourth positioning ring, a fifth positioning ring and a sixth positioning ring are arranged in the mounting cavity; the first positioning ring cooperates with the retaining ring for snap positioning, the first positioning ring abuts against the periphery of the front end surface of the first lens, the second positioning ring is clamped between the first lens and the second lens, the third positioning ring is clamped between the second lens and the third lens, the fourth positioning ring is clamped between the third lens and the fourth lens, the fifth positioning ring is clamped between the fourth lens and the fifth lens, the sixth positioning ring is clamped between the fifth lens and the sixth lens, and the periphery of the rear end surface of the sixth lens abuts against the front end surface of the limiting ring.

3. The large aperture low distortion projection lens according to claim 2, characterized in that: The outer periphery of the aperture is fitted and fixed to the inner periphery of the fourth positioning ring.

4. The large aperture low distortion projection lens according to claim 2, characterized in that: The front end of the lens barrel is in a trumpet shape, and the rear end of the lens barrel is in a multi-section cylindrical shape.

5. The large aperture low distortion projection lens according to claim 2, characterized in that: The lens barrel is made of plastic, and the first positioning ring, the second positioning ring, the third positioning ring, the fourth positioning ring, the fifth positioning ring and the sixth positioning ring are all made of aluminum alloy.

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