A large field of view telescope optical system

Abstract

The application discloses a large-view-field telescope optical system and belongs to the technical field of telescope manufacturing, characterized in that, from the object side to the image side, an objective lens first lens, an objective lens second lens, an objective lens third lens, a focusing mirror, a half-pentagonal prism, a roof prism, an eyepiece first lens, an eyepiece second lens, an eyepiece third lens, an eyepiece fourth lens, an eyepiece fifth lens and an eyepiece sixth lens are sequentially arranged; the magnification is 12 times; the entrance pupil diameter is 49 mm; the pupil diameter is 4.18 mm; the field of view is 5.6 degrees; and the eye point distance is 16.4 mm.

Description

Technical Field

[0001] This invention relates to the field of telescope manufacturing technology, specifically to a large field-of-view telescope optical system. Background Technology

[0002] With the continuous development of processing technology and design concepts, the market share of roof prism telescopes is constantly increasing. The key to a roof prism lies in the presence of a ridge surface. This ridge surface is a roof-shaped reflecting surface sandwiched between two reflecting surfaces within the light path. The edges of these two surfaces are located in the center of the light path, so some roof prisms show a dividing line in the middle. This can be understood as splitting the light beam in two and then reassembling it. However, currently, roof prism telescopes on the market have a relatively small field of view. Summary of the Invention

[0003] The purpose of this invention is to provide a large field-of-view telescope optical system to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a large field-of-view telescope optical system, characterized in that: from the object side to the image side, the following are arranged in sequence: objective lens first, objective lens second, objective lens third, focusing lens, semi-pentagonal prism, roof prism, eyepiece first, eyepiece second, eyepiece third, eyepiece fourth, eyepiece fifth, and eyepiece sixth. The first and second objective lenses form a cemented lens. The first objective lens is a concave-convex lens with its convex surface facing the object side. The second objective lens is a biconvex lens. The third objective lens is a concave-convex lens with its convex surface facing the object side. The focusing lens is a concave-convex lens with its convex surface facing the object side. The first and second eyepiece lenses are placed close together. The first eyepiece lens is a biconcave lens. The second eyepiece lens is a concave-convex lens with its concave surface facing the object side. The third and fourth eyepiece lenses form a cemented lens. The third eyepiece lens is a biconcave lens. The fourth eyepiece lens is a biconvex lens. The fifth eyepiece lens is a biconvex lens. The sixth eyepiece lens is a concave-convex lens with its convex surface facing the object side. Only these 10 lenses in the optical system have optical power.

[0005] As a preferred technical solution, the first objective lens has an object-side radius of curvature of 206.50 mm, an image-side radius of curvature of 70.815 mm, a center thickness of 2.0 mm, is made of H-ZBAF21 glass, and has a diameter of 51 mm; the second objective lens has an object-side radius of curvature of 70.815 mm, an image-side radius of curvature of -335.10 mm, a center thickness of 7.0 mm, is made of H-FK61B glass, and has a diameter of 51 mm; the third objective lens has an object-side radius of curvature of 67.508 mm, an image-side radius of curvature of -335.10 mm, and a center thickness of 2.0 mm, is made of H-FK61B glass, and has a diameter of 51 mm. The focusing lens has an object-side radius of curvature of 398.20 mm, a center thickness of 5.6 mm, is made of H-K9L glass, and has a diameter of 50 mm. The focusing lens has an object-side radius of curvature of 454.90 mm, an image-side radius of curvature of 72.866 mm, a center thickness of 2.0 mm, is made of H-QK3L glass, and has a diameter of 25 mm. The first eyepiece lens has an object-side radius of curvature of -23.637 mm, an image-side radius of curvature of 52.086 mm, a center thickness of 2.0 mm, is made of H-K9L glass, and has a diameter of 23 mm. The second eyepiece lens has an object-side radius of curvature of -58.843 mm, an image-side radius of curvature of -19.355 mm, a center thickness of 5.5 mm, is made of H-BAK7 glass, and has a diameter of 23 mm. The third eyepiece lens has an object-side radius of curvature of -30.342 mm, an image-side radius of curvature of 20.29 mm, a center thickness of 2.0 mm, is made of H-ZF52GT glass, and has a diameter of 25 mm. The fourth eyepiece lens has an object-side radius of curvature of 20.29 mm and an image-side radius of curvature of -20 mm. The first eyepiece has an object-side radius of curvature of 29mm, a center thickness of 9.7mm, is made of glass H-LAK51A, and has a diameter of 25mm; the second eyepiece has an object-side radius of curvature of 63.97mm, an image-side radius of curvature of -63.97mm, a center thickness of 3.8mm, is made of glass H-LAK7A, and has a diameter of 26mm; the third eyepiece has an object-side radius of curvature of 17.243mm, an image-side radius of curvature of 200.00mm, a center thickness of 5.7mm, is made of glass H-QK3L, and has a diameter of 24mm.

[0006] As a preferred technical solution, the distance between the second and third objective lenses along the optical axis is 0.5 mm, the distance between the third objective lens and the focusing lens is 58.5 mm, the distance between the focusing lens and the semi-pentaprism is 22.22 mm, the distance between the roof prism and the first eyepiece lens is 9.3 mm, the distance between the second and third eyepiece lenses is 16.27 mm, the distance between the fourth and fifth eyepiece lenses is 0.3 mm, and the distance between the fifth and sixth eyepiece lenses is 0.3 mm.

[0007] As a preferred technical solution, the focusing lens can be moved 3mm towards the object side and 7.5mm towards the image side for focusing.

[0008] The beneficial effects achieved by the invention are: The optical system of this application has a magnification of 12x, an entrance pupil diameter of 49mm, a pupil diameter of 4.18mm, a field of view of 5.6°, an eyepoint distance of 16.4mm, and a minimum focusing distance of 4.0m. The objective lens group consists of a first objective lens, a second objective lens, a third objective lens, and a focusing lens, with a focal length of 180.942mm. The eyepiece group consists of a first eyepiece to a sixth eyepiece, with a focal length of 15.44mm. Attached Figure Description

[0009] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the optical system of the present invention; Figure 2 This is a dot diagram of the present invention; Figure 3 This is the field distortion diagram of the present invention; Figure 4 This is the aberration map of the present invention. Detailed Implementation

[0010] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] like Figure 1 As shown, the present invention provides the following technical solution: a large field-of-view telescope optical system, characterized in that: from the object side to the image side, the following are arranged in sequence: objective lens 1, objective lens 2, objective lens 3, focusing lens 4, semi-pentagonal prism 5, roof prism 6, eyepiece lens 7, eyepiece lens 8, eyepiece lens 9, eyepiece lens 4, eyepiece lens 10, eyepiece lens 11, and eyepiece lens 12; Objective lens 1 and objective lens 2 form a cemented lens. Objective lens 1 is a concave-convex lens with the convex surface facing the object side. Objective lens 2 is a biconvex lens. Objective lens 3 is a concave-convex lens with the convex surface facing the object side. Focusing lens 4 is a concave-convex lens with the convex surface facing the object side. Eyepiece lens 7 and eyepiece lens 8 are placed close together. Eyepiece lens 7 is a biconcave lens. Eyepiece lens 8 is a concave-convex lens with the concave surface facing the object side. Eyepiece lens 9 and eyepiece lens 10 form a cemented lens. Eyepiece lens 9 is a biconcave lens. Eyepiece lens 10 is a biconvex lens. Eyepiece lens 11 is a biconvex lens. Eyepiece lens 12 is a concave-convex lens with the convex surface facing the object side. Only the above 10 lenses in the optical system have optical power.

[0012] The first objective lens 1 has an object-side radius of curvature of 206.50 mm, an image-side radius of curvature of 70.815 mm, a center thickness of 2.0 mm, is made of H-ZBAF21 glass, and has a diameter of 51 mm. The second objective lens 2 has an object-side radius of curvature of 70.815 mm, an image-side radius of curvature of -335.10 mm, a center thickness of 7.0 mm, is made of H-FK61B glass, and has a diameter of 51 mm. The third objective lens 3 has an object-side radius of curvature of 67.508 mm and an image-side radius of curvature of 39 mm. 8.20mm, center thickness 5.6mm, material H-K9L glass, diameter 50mm; focusing lens 4 has an object-side radius of curvature of 454.90mm, an image-side radius of curvature of 72.866mm, center thickness 2.0mm, material H-QK3L glass, diameter 25mm; eyepiece first lens 7 has an object-side radius of curvature of -23.637mm, an image-side radius of curvature of 52.086mm, center thickness 2.0mm, material H-K9L glass, diameter 23mm; eyepiece second... Lens 8 has an object-side radius of curvature of -58.843 mm, an image-side radius of curvature of -19.355 mm, a center thickness of 5.5 mm, is made of H-BAK7 glass, and has a diameter of 23 mm. Eyepiece 9 has an object-side radius of curvature of -30.342 mm, an image-side radius of curvature of 20.29 mm, a center thickness of 2.0 mm, is made of H-ZF52GT glass, and has a diameter of 25 mm. Eyepiece 10 has an object-side radius of curvature of 20.29 mm and an image-side radius of curvature of -20.29 mm. The first eyepiece has a center thickness of 9.7 mm, is made of H-LAK51A glass, and has a diameter of 25 mm. The second eyepiece has an object-side radius of curvature of 63.97 mm, an image-side radius of curvature of -63.97 mm, a center thickness of 3.8 mm, is made of H-LAK7A glass, and has a diameter of 26 mm. The third eyepiece has an object-side radius of curvature of 17.243 mm, an image-side radius of curvature of 200.00 mm, a center thickness of 5.7 mm, is made of H-QK3L glass, and has a diameter of 24 mm.

[0013] Along the optical axis, the distance between the second objective lens 2 and the third objective lens 3 is 0.5 mm, the distance between the third objective lens 3 and the focusing lens 4 is 58.5 mm, the distance between the focusing lens 4 and the semi-pentagonal prism 5 is 22.22 mm, the distance between the roof prism 6 and the first eyepiece lens 7 is 9.3 mm, the distance between the second eyepiece lens 8 and the third eyepiece lens 9 is 16.27 mm, the distance between the fourth eyepiece lens 10 and the fifth eyepiece lens 11 is 0.3 mm, and the distance between the fifth eyepiece lens 11 and the sixth eyepiece lens 12 is 0.3 mm. The focusing lens 4 can be moved 3 mm towards the object side and 7.5 mm towards the image side for focusing.

[0014] Figure 1 This is an optical path diagram of the present invention, mainly showing the structure and positional relationship of the optical lenses of the present invention. The optical system of this application has a magnification of 12x, an entrance pupil diameter of 49mm, a pupil diameter of 4.18mm, a field of view of 5.6°, an eyepoint distance of 16.4mm, and a minimum focusing distance of 4.0m. The objective lens group consists of the first objective lens, the second objective lens, the third objective lens, and the focusing lens, with a focal length of 180.942mm. The eyepiece group consists of the first eyepiece to the sixth eyepiece, with a focal length of 15.44mm.

[0015] Figure 2 This is a dot plot of the present invention. The visible light wavelength is 400-700nm. The dot plot selects three wavelength bands for description, namely 486.133nm, 587.562nm, and 656.273nm. In principle, the more concentrated the light spot is, the more concentrated the display energy is, and the higher the imaging quality is. The light spot of the present invention is relatively concentrated, and the imaging quality is very high.

[0016] Figure 3 This is a field curvature distortion diagram from this invention application. Field curvature distortion is mainly used to describe the deformation of the image plane edge after imaging. The maximum distortion in this application is 6.5%, and the image plane will bend at the edge after imaging.

[0017] Figure 4 This is the aberration diagram of this application. The aberration diagram describes the change curve of the entire field of view from the center to the edge. In principle, the more concentrated and overlapping the curves are, the better the imaging quality. This application selects the aberrations at six field of view points. Since the aberration diagram of this application is a half-field curve, the field of view of the entire optical system is twice that of the half-field. The fields of view of this application are 0°, 0.87°, 1.45°, 2.0503°, 2.4650°, and 2.9°, and the wavelengths are 0.486µm, 0.587µm, and 0.656µm, respectively. It can be seen from the aberration diagram that under the same field of view at different wavelengths, the three curves have a high degree of overlap, and the imaging quality is also good.

[0018] We through the Figures 1-4 Overall, our analysis shows that the optical system has good image quality, high resolution, and high sharpness, but there is some image plane curvature at the edges. Overall, it is a relatively good telescope optical system. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A wide field-of-view telescope optical system, characterized in that: From the object side to the image side, the following lenses are arranged in sequence: first objective lens (1), second objective lens (2), third objective lens (3), focusing lens (4), semi-pentagonal prism (5), roof prism (6), first eyepiece lens (7), second eyepiece lens (8), third eyepiece lens (9), fourth eyepiece lens (10), fifth eyepiece lens (11), and sixth eyepiece lens (12). The first objective lens (1) and the second objective lens (2) form a cemented lens. The first objective lens (1) is a concave-convex lens with the convex surface facing the object side. The second objective lens (2) is a biconvex lens. The third objective lens (3) is a concave-convex lens with the convex surface facing the object side. The focusing lens (4) is a concave-convex lens with the convex surface facing the object side. The first eyepiece lens (7) and the second eyepiece lens (8) are close together. The first eyepiece lens (7) is a biconcave lens. The second eyepiece lens (8) is a concave-convex lens with the concave surface facing the object side. The third eyepiece lens (9) and the fourth eyepiece lens (10) form a cemented lens. The third eyepiece lens (9) is a biconcave lens. The fourth eyepiece lens (10) is a biconvex lens. The fifth eyepiece lens (11) is a biconvex lens. The sixth eyepiece lens (12) is a concave-convex lens with the convex surface facing the object side. Only the above 10 lenses in the optical system have optical power.

2. The large field-of-view telescope optical system according to claim 1, characterized in that: The objective lens (1) has an object-side radius of curvature of 206.50 mm, an image-side radius of curvature of 70.815 mm, a center thickness of 2.0 mm, is made of H-ZBAF21 glass, and has a diameter of 51 mm; the objective lens (2) has an object-side radius of curvature of 70.815 mm, an image-side radius of curvature of -335.10 mm, a center thickness of 7.0 mm, is made of H-FK61B glass, and has a diameter of 51 mm; the objective lens (3) has an object-side radius of curvature of 67.508 mm, an image-side radius of curvature of 3... 98.20mm, center thickness is 5.6mm, material is H-K9L glass, diameter is 50mm; focusing lens (4) has an object-side radius of curvature of 454.90mm, an image-side radius of curvature of 72.866mm, center thickness is 2.0mm, material is H-QK3L glass, diameter is 25mm; eyepiece first lens (7) has an object-side radius of curvature of -23.637mm, an image-side radius of curvature of 52.086mm, center thickness is 2.0mm, material is H-K9L glass, diameter is 23mm; eyepiece second The second lens (8) has an object-side radius of curvature of -58.843 mm, an image-side radius of curvature of -19.355 mm, a center thickness of 5.5 mm, is made of H-BAK7 glass, and has a diameter of 23 mm; the third eyepiece lens (9) has an object-side radius of curvature of -30.342 mm, an image-side radius of curvature of 20.29 mm, a center thickness of 2.0 mm, is made of H-ZF52GT glass, and has a diameter of 25 mm; the fourth eyepiece lens (10) has an object-side radius of curvature of 20.29 mm and an image-side radius of curvature of -20.29 mm. The center thickness is 9.7mm, the material is glass H-LAK51A, and the diameter is 25mm; the fifth eyepiece (11) has an object-side radius of curvature of 63.97mm, an image-side radius of curvature of -63.97mm, a center thickness of 3.8mm, the material is glass H-LAK7A, and the diameter is 26mm; the sixth eyepiece (12) has an object-side radius of curvature of 17.243mm, an image-side radius of curvature of 200.00mm, a center thickness of 5.7mm, the material is glass H-QK3L, and the diameter is 24mm.

3. The large field-of-view telescope optical system according to claim 1, characterized in that: Along the optical axis, the distance between the second objective lens (2) and the third objective lens (3) is 0.5 mm, the distance between the third objective lens (3) and the focusing lens (4) is 58.5 mm, the distance between the focusing lens (4) and the semi-pentagonal prism (5) is 22.22 mm, the distance between the roof prism (6) and the first eyepiece lens (7) is 9.3 mm, the distance between the second eyepiece lens (8) and the third eyepiece lens (9) is 16.27 mm, the distance between the fourth eyepiece lens (10) and the fifth eyepiece lens (11) is 0.3 mm, and the distance between the fifth eyepiece lens (11) and the sixth eyepiece lens (12) is 0.3 mm.

4. The large field-of-view telescope optical system according to claim 1, characterized in that: The focusing lens (4) can be moved 3mm towards the object side and 7.5mm towards the image side for focusing.

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