Eyepieces and observation equipment

Abstract

The present invention discloses an eyepiece and observation equipment. The eyepiece includes a housing and a refractive lens group installed in the inner cavity of the housing. The refractive lens group forms an optical axis corresponding to the housing. The refractive lens group includes, from the object side to the image side, a first biconvex spherical lens, a second meniscus spherical lens, a third biconvex spherical lens, a fourth biconvex spherical lens, a fifth meniscus spherical lens, and a sixth biconcave spherical lens. The concave surface of the second meniscus spherical lens is arranged toward the image side, and the concave surface of the fifth meniscus spherical lens is arranged toward the object side. In the technical solution provided by the present invention, by arranging the six spherical lenses mentioned above, an eyepiece with a large exit pupil diameter is provided.

Description

Technical Field

[0001] The present invention relates to the field of acoustic technology, in particular to an eyepiece and an observation device. Background Art

[0002] As an optical system near the eye, the eyepiece is typically used in conjunction with an objective lens to magnify the image formed by the lens, enabling various devices such as telescopes and microscopes. Currently, they are widely used in the military, industrial instrumentation, security, and medical industries. For example, as a night vision device, it can be paired with a low-light-level objective lens or a long-wave infrared objective lens to form a helmet-mounted telescope for individual combat, allowing clear observation of the enemy and the surrounding environment at night.

[0003] The most critical factors for night vision goggles are weight, portability, and a large eyepiece exit pupil diameter. They must be suitable not only for static use but also for observation in motion. Furthermore, they must have good image quality and a wide diopter adjustment range. To optimize image quality and weight, eyepieces currently on the market typically have smaller target surfaces, smaller exit pupil diameters, use aspherical lenses, or shorten the diopter adjustment range. A small exit pupil diameter can affect image clarity if the eye is slightly offset from the center of the eyepiece. Summary of the Invention

[0004] The main purpose of the present invention is to provide an eyepiece and an observation device, aiming to provide an eyepiece with a large exit pupil diameter.

[0005] To achieve the above-mentioned objectives, the present invention proposes an eyepiece, wherein the eyepiece includes a shell and a refractive lens group installed in the inner cavity of the shell, the refractive lens group corresponding to forming an optical axis in the shell, and the refractive lens group includes, from the object side to the image side, a first biconvex spherical lens, a second meniscus spherical lens, a third biconvex spherical lens, a fourth biconvex spherical lens, a fifth meniscus spherical lens, and a sixth biconcave spherical lens, wherein the concave surface of the second meniscus spherical lens is arranged toward the eyepoint side, and the concave surface of the fifth meniscus spherical lens is arranged toward the object side.

[0006] Optionally, the first biconvex spherical lens has a positive optical power; and / or,

[0007] The optical power of the second meniscus spherical lens is negative; and / or,

[0008] The third biconvex spherical lens has a positive optical power; and / or,

[0009] The fourth biconvex spherical lens has a positive optical power; and / or,

[0010] The optical power of the fifth meniscus spherical lens is positive; and / or,

[0011] The sixth biconcave spherical lens has negative optical power.

[0012] Optionally, the total focal length of the eyepiece is f, the focal length of the first biconvex spherical lens is f1, the focal length of the second meniscus spherical lens is f2, the focal length of the third biconvex spherical lens is f3, the focal length of the fourth biconvex spherical lens is f4, the focal length of the fifth meniscus spherical lens is f5, and the focal length of the sixth biconcave spherical lens is f6; wherein,

[0013] 0.8<f1 / f<1.5;and / or,

[0014] -1.5<f2 / f<-0.8;and / or,

[0015] 1<f3 / f<2;and / or,

[0016] 1<f4 / f<2;and / or,

[0017] 2<f5 / f<3.5;and / or,

[0018] -1.5<f6 / f<-0.5.

[0019] Optionally, the dispersion coefficient of the first biconvex spherical lens is Vd1, 30<Vd1<50; and / or,

[0020] The dispersion coefficient of the second meniscus spherical lens is Vd2, 15<Vd2<35; and / or,

[0021] The dispersion coefficient of the third biconvex spherical lens is Vd3, 30<Vd3<50; and / or,

[0022] The dispersion coefficient of the fourth biconvex spherical lens is Vd4, 30<Vd4<50; and / or,

[0023] The dispersion coefficient of the fifth meniscus spherical lens is Vd5, 15<Vd5<30; and / or,

[0024] The dispersion coefficient of the sixth biconcave spherical lens is Vd6, 15<Vd6<30.

[0025] Optionally, the eyepiece further includes an aperture located on the optical axis, and the aperture is arranged close to a side of the first biconvex spherical lens close to the eye point.

[0026] Optionally, the length of the eyepiece is D, and the total focal length of the eyepiece is f, wherein D / f<1.5.

[0027] Optionally, at least one of the first biconvex spherical lens, the second meniscus spherical lens, the third biconvex spherical lens, the fourth biconvex spherical lens, the fifth meniscus spherical lens, and the sixth biconcave spherical lens is made of glass.

[0028] Optionally, the eyepiece further includes an OLED or an image intensifier located on the optical axis, and the OLED or the image intensifier is arranged close to the object side of the sixth biconcave spherical lens.

[0029] The present invention provides an observation device, which includes an eyepiece. The eyepiece includes a shell and a refractive lens group installed in the inner cavity of the shell. The refractive lens group forms an optical axis corresponding to the shell. The refractive lens group includes, from the object side to the image side, a first biconvex spherical lens, a second meniscus spherical lens, a third biconvex spherical lens, a fourth biconvex spherical lens, a fifth meniscus spherical lens, and a sixth biconcave spherical lens. The concave surface of the second meniscus spherical lens is arranged toward the image side, and the concave surface of the fifth meniscus spherical lens is arranged toward the object side.

[0030] Optionally, the observation equipment includes night vision goggles, a microscope or a helmet telescope.

[0031] In the technical solution provided by the present invention, the lens comprises, from the object side to the image side, a first biconvex spherical lens, a second meniscus spherical lens, a third biconvex spherical lens, a fourth biconvex spherical lens, a fifth meniscus spherical lens, and a sixth biconcave spherical lens, wherein the concave surface of the second meniscus spherical lens is arranged toward the eye point side, and the concave surface of the fifth meniscus spherical lens is arranged toward the object side. The large aperture of the first biconvex spherical lens enables the human eye to move in a wider range, thereby achieving a large exit pupil diameter. The second meniscus spherical lens is used to offset the eye point. Eliminate the astigmatism and chromatic aberration produced by the front lens, the third biconvex spherical lens is mainly used to offset the distortion and chromatic aberration brought by the second lens, the fourth biconvex spherical lens is mainly used to change the direction of light, speed up focusing, and shorten the total length, the fifth meniscus spherical lens can offset the field curvature and chromatic aberration brought by the negative lens, and the sixth biconcave spherical lens is used to offset the spherical aberration, field curvature and other aberrations brought by the front lens, while lengthening the back focal length to achieve the effect of ±5D diopter adjustment. By setting the above six spherical lenses, an eyepiece with a large exit pupil diameter is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0033] Figure 1 A schematic structural diagram of an embodiment of an eyepiece provided by the present invention;

[0034] Figure 2 for Figure 1 Schematic diagram of the structure of the eyepiece at the center of the human eye's φ5mm pupil offset;

[0035] Figure 3 for Figure 1 The MTF curve of the eyepiece at room temperature facing the center of the exit pupil diameter;

[0036] Figure 4 for Figure 1 The MTF curve of the eyepiece in the center of the human eye with a pupil offset of φ5mm;

[0037] Figure 5 for Figure 1 MTF curve of the eyepiece at -40℃;

[0038] Figure 6 for Figure 1 MTF curve of the eyepiece at high temperature +60℃;

[0039] Figure 7 for Figure 1 The distortion curve of the eyepiece at room temperature facing the center of the exit pupil diameter.

[0040] Description of Figure Numbers:

[0041]

[0042] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0044] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0045] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] Eyepieces, as optical systems near the eye, are typically used in conjunction with an objective lens to magnify the image formed by the lens, enabling various devices such as telescopes and microscopes. They are currently widely used in the military, industrial instrumentation, security, and medical industries. For example, in night vision devices, they can be paired with low-light-level or long-wave infrared lenses to form helmet-mounted telescopes, enabling clear observation of the enemy and surrounding environment at night. Key considerations for night vision devices are weight and size, portability, a large eyepiece exit pupil diameter, and excellent image quality and a wide diopter adjustment range. To optimize image quality and weight, current eyepieces often utilize smaller target surfaces, smaller exit pupil diameters, aspherical surfaces, or a shorter diopter adjustment range. A small exit pupil diameter can affect image clarity if the eye is slightly offset from the center of the eyepiece.

[0047] In order to solve the above problems, the present invention provides an eyepiece 100, Figure 1 This is a specific embodiment of the eyepiece 100 provided by the present invention. Figures 2 to 7 Schematic diagram of the technical indicators of the eyepiece 100 provided by the present invention.

[0048] See also Figure 1 The eyepiece 100 includes a shell and a refractive lens group installed in the inner cavity of the shell, the refractive lens group forms an optical axis corresponding to the shell, and the refractive lens group includes a first biconvex spherical lens 1, a second meniscus spherical lens 2, a third biconvex spherical lens 3, a fourth biconvex spherical lens 4, a fifth meniscus spherical lens 5, and a sixth biconcave spherical lens 6 from the object side to the image side, wherein the concave surface of the second meniscus spherical lens 2 is arranged toward the image side, and the concave surface of the fifth meniscus spherical lens 5 is arranged toward the object side.

[0049] It's important to note that existing eyepiece designs have a small exit pupil diameter, so the eyepoint can only be placed at the center of the exit pupil. If the eye strays from the optical axis during movement, such as when walking or riding in a vehicle, the image formed at the eyepoint will be unclear. Furthermore, similar eyepiece lenses have a short diopter adjustment range, typically only ±3D, making them unsuitable for people with severe myopia or hyperopia, as they cannot be adjusted to a comfortable position for the eye.

[0050] In the technical solution provided by the present invention, the lens comprises, from the object side to the image side, a first biconvex spherical lens 1, a second meniscus spherical lens 2, a third biconvex spherical lens 3, a fourth biconvex spherical lens 4, a fifth meniscus spherical lens 5, and a sixth biconcave spherical lens 6. The concave surface of the second meniscus spherical lens 2 is arranged toward the image side, and the concave surface of the fifth meniscus spherical lens 5 is arranged toward the object side. The large aperture of the first biconvex spherical lens 1 allows the human eye to move in a wider range, thereby achieving a large exit pupil diameter. The second meniscus spherical lens 2 is used to To offset the astigmatism and chromatic aberration produced by the front lens, the third biconvex spherical lens 3 is mainly used to offset the distortion and chromatic aberration brought by the second lens. The fourth biconvex spherical lens 4 is mainly used to change the direction of light, speed up focusing, and shorten the total length. The fifth meniscus spherical lens 5 can offset the field curvature and chromatic aberration brought by the negative lens. The sixth biconcave spherical lens 6 is used to offset the spherical aberration, field curvature and other aberrations brought by the front lens, and at the same time lengthen the back focal length to achieve the effect of ±5D diopter adjustment. By setting the above-mentioned six spherical lenses, an eyepiece 100 with a large exit pupil diameter is provided.

[0051] It should be noted that the basic parameters of the eyepiece 100 with a large exit pupil diameter in this embodiment are shown in Table 1, where the units of the curvature radius and thickness are both millimeters (mm).

[0052] Table 1

[0053]

[0054] Specifically, in one embodiment, the first biconvex spherical lens 1 has a positive optical power; and / or the second meniscus spherical lens 2 has a negative optical power; and / or the third biconvex spherical lens 3 has a positive optical power; and / or the fourth biconvex spherical lens 4 has a positive optical power; and / or the fifth meniscus spherical lens 5 has a positive optical power; and / or the sixth biconcave spherical lens 6 has a negative optical power. Preferably, the first biconvex spherical lens 1 has a positive optical power; the second meniscus spherical lens 2 has a negative optical power; the third biconvex spherical lens 3 has a positive optical power; the fourth biconvex spherical lens 4 has a positive optical power; the fifth meniscus spherical lens 5 has a positive optical power; and the sixth biconcave spherical lens 6 has a negative optical power. This setting, through the reasonable distribution of lens optical power, adjustment of glass shape and material combination, effectively eliminates chromatic aberration and secondary spectrum, so that the spherical aberration, coma, astigmatism, etc. on each lens compensate and cancel each other to achieve a clear imaging effect.

[0055] Specifically, in order to enable the spherical lenses to cooperate with each other to achieve the desired effect, in this embodiment, the total focal length of the eyepiece 100 is f, the focal length of the first biconvex spherical lens 1 is f1, 0.8<f1 / f<1.5, the focal length of the second meniscus spherical lens 2 is f2, -1.5<f2 / f<-0.8, the focal length of the third biconvex spherical lens 3 is f3, 1<f3 / f<2, the focal length of the fourth biconvex spherical lens 4 is f4, 1<f4 / f<2, the focal length of the fifth meniscus spherical lens 5 is f5, 2<f5 / f<3.5, and the focal length of the sixth biconcave spherical lens 6 is f6, -1.5<f6 / f<-0.5.

[0056] Furthermore, in this embodiment, the dispersion coefficient of the first biconvex spherical lens 1 is Vd1, 30<Vd1<50; and / or the dispersion coefficient of the second meniscus spherical lens 2 is Vd2, 15<Vd2<35; and / or the dispersion coefficient of the third biconvex spherical lens 3 is Vd3, 30<Vd3<50; and / or the dispersion coefficient of the fourth biconvex spherical lens 4 is Vd4, 30<Vd4<50; and / or the dispersion coefficient of the fifth meniscus spherical lens 5 is Vd5, 15<Vd5<30; and / or the dispersion coefficient of the sixth biconcave spherical lens 6 is Vd6, 15<Vd6<30. This configuration makes the dispersion of the eyepiece 100 less noticeable and the imaging quality of the lens good. In existing eyepieces, the target surface is usually only 0.4-0.6 inches. Due to its small photosensitive area, the signal-to-noise ratio is high. In this embodiment, a large 1.1-inch target surface is used to achieve high-definition observation, and the field of view angle can reach 35°. The high resolution allows for a wider observation range.

[0057] Furthermore, to improve image quality, in this embodiment, the eyepiece 100 further includes an aperture 7 located on the optical axis. The aperture 7 is positioned near the eye point of the first biconvex spherical lens 1, thereby limiting the aperture of the on-axis light beam and improving image quality. The aperture 7 and the aforementioned six lenses work together to achieve an exit pupil diameter of φ30 mm and an adjustable diopter of ±5D. This meets the needs of different people for myopia or hyperopia, providing more comfortable use.

[0058] Specifically, to expand the scope of use for the eyepiece 100, in this embodiment, the length of the eyepiece 100 is D, and the total focal length of the eyepiece 100 is f, where D / f < 1.5. This arrangement significantly shortens the lens length, reduces the size, and reduces the total weight of the lens to less than 45g. Given such a large entrance pupil diameter, the weight is minimized, reducing the carrying burden.

[0059] Furthermore, in the prior art, similar eyepieces 100 utilize plastic aspheric surfaces to control costs, resulting in poor lens reliability and inability to adapt to harsh environments. To enhance the stability of the eyepiece 100, in one embodiment, at least one of the first biconvex spherical lens 1, the second meniscus spherical lens 2, the third biconvex spherical lens 3, the fourth biconvex spherical lens 4, the fifth meniscus spherical lens 5, and the sixth biconcave spherical lens 6 is made of glass. Preferably, in this embodiment, all six spherical lenses of the eyepiece 100 are made of glass. This, through the rational allocation of lens power and consideration of the thermal expansion coefficient of the glass material, enables clear imaging in environments between -40°C and +60°C, ensuring a high yield in processing and assembly, further reducing costs, while also ensuring high product reliability and meeting military standards.

[0060] Please note that Figures 3 to 6 Using the human eye's 5mm pupil offset as an example, the figure shows minimal performance differences across various states, with good consistency. Excellent performance is maintained at temperatures as low as -40°C and as high as +60°C. At 40lp, MTF is ≥ 0.3 within a 0.8 field of view, demonstrating high image quality. Performance in the offset state is excellent, ensuring clear vision even when the eye is not aligned with the exit pupil center. Furthermore, performance differences across temperature states are minimal, with good consistency, enabling clear imaging at both high and low temperatures without focusing. Figure 7 This is the distortion diagram facing the center of the exit pupil diameter at normal temperature. It can be seen that the distortion is less than 1%, which is very small. The human eye observes the picture without distortion and it is more comfortable.

[0061] Furthermore, the eyepiece 100 also includes an organic light-emitting semiconductor (OLED) or an image intensifier located on the optical axis. The OLED or the image intensifier is disposed near the object side of the sixth biconcave spherical lens 6. Organic light-emitting semiconductors have advantages such as low power consumption, fast response speed, wide viewing angle, high-resolution display, wide temperature characteristics, and relatively light weight. Compared with other products, OLEDs are relatively light in weight and thinner than LCDs. They also have a high shock resistance coefficient and can adapt to harsh environments such as large acceleration and vibration.

[0062] The present invention also provides an observation device, which includes the above-mentioned eyepiece 100. The observation device includes a night vision device, a microscope or a helmet telescope, etc. Since the observation device includes the eyepiece 100, the specific structure of the eyepiece 100 refers to the above-mentioned embodiment. Since the eyepiece 100 of this observation device adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0063] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An eyepiece, characterized in that: The invention comprises a housing and a refractive lens group installed in an inner cavity of the housing, wherein the refractive lens group forms an optical axis corresponding to the housing, and the refractive lens group comprises, from the eye point side to the object side, a first biconvex spherical lens, a second meniscus spherical lens, a third biconvex spherical lens, a fourth biconvex spherical lens, a fifth meniscus spherical lens, and a sixth biconcave spherical lens, wherein the concave surface of the second meniscus spherical lens is arranged toward the eye point side, and the concave surface of the fifth meniscus spherical lens is arranged toward the object side; The optical power of the first biconvex spherical lens is positive; The second meniscus spherical lens has a negative optical power; The third biconvex spherical lens has a positive optical power; The fourth biconvex spherical lens has a positive optical power; The optical power of the fifth meniscus spherical lens is positive; The sixth biconcave spherical lens has a negative optical power; The total focal length of the eyepiece is f, the focal length of the first biconvex spherical lens is f1, the focal length of the second meniscus spherical lens is f2, the focal length of the third biconvex spherical lens is f3, the focal length of the fourth biconvex spherical lens is f4, the focal length of the fifth meniscus spherical lens is f5, and the focal length of the sixth biconcave spherical lens is f6; wherein, 0.8<f1 / f<1.5; -1.5<f2 / f<-0.8; 1<f3 / f<2; 1<f4 / f<2; 2<f5 / f<3.5; -1.5<f6 / f<-0.

5.

2. The eyepiece according to claim 1, wherein The dispersion coefficient of the first biconvex spherical lens is Vd1, 30<Vd1<50; and / or, The dispersion coefficient of the second meniscus spherical lens is Vd2, 15<Vd2<35; and / or, The dispersion coefficient of the third biconvex spherical lens is Vd3, 30<Vd3<50; and / or, The dispersion coefficient of the fourth biconvex spherical lens is Vd4, 30<Vd4<50; and / or, The dispersion coefficient of the fifth meniscus spherical lens is Vd5, 15<Vd5<30; and / or, The dispersion coefficient of the sixth biconcave spherical lens is Vd6, 15<Vd6<30.

3. The eyepiece according to claim 1, wherein The eyepiece further includes an aperture located on the optical axis, and the aperture is arranged close to a side of the first biconvex spherical lens close to the eye point.

4. The eyepiece according to claim 1, wherein The length of the eyepiece is D, and the total focal length of the eyepiece is f, wherein D / f<1.

5.

5. The eyepiece according to claim 1, wherein: At least one of the first biconvex spherical lens, the second meniscus spherical lens, the third biconvex spherical lens, the fourth biconvex spherical lens, the fifth meniscus spherical lens, and the sixth biconcave spherical lens is made of glass.

6. The eyepiece according to claim 1, wherein: The eyepiece further includes an OLED or an image intensifier located on the optical axis, and the OLED or the image intensifier is arranged close to the object side of the sixth biconcave spherical lens.

7. An observation device, characterized in that: Comprising an eyepiece as claimed in any one of claims 1 to 6.

8. The observation device according to claim 7, characterized in that The observation equipment includes night vision goggles, microscopes or helmet telescopes.

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