Refraction and reflection telescope system

Abstract

The invention provides a catadioptric telescope system which comprises a reflection secondary mirror M2, a reflection primary mirror M1, a meniscus positive lens A, a biconcave negative lens B, a biconvex positive lens C and a meniscus positive lens D. A light hole is formed in the middle of the reflection primary mirror M1, light rays are reflected to the reflection secondary mirror M2 through the reflection primary mirror M1, then the light rays are reflected by the reflection secondary mirror M2 to pass through the light hole, and the light rays pass through the biconcave negative lens B, the biconvex positive lens C and the meniscus positive lens D. And finally, the light passes through the meniscus positive lens A, the biconcave negative lens B, the biconvex positive lens C and the meniscus positive lens D in sequence. The catadioptric telescope system provided by the invention can realize the following beneficial effects: the used wavelength is 900-1700 nm; an image space MTF: gt; 50 lp / mm at 0.4 atm; f number: F / # = 2.6; the focal length is 760 mm; the distortion is less than 0.8%; the linear light blocking ratio is gt; 0.4 part; an RMS wavefront error: lt; 0.18 lambda.

Description

Technical Field

[0001] This invention relates to the field of telescope technology, and in particular to a catadioptric telescope system. Background Technology

[0002] The advantages of catadioptric telescopes lie in combining the strengths of both refracting and reflecting mirrors, such as low chromatic aberration, bright imaging, short telescope body, large aperture, strong light output, and wide field of view, making them suitable for sky survey photography and observing celestial objects such as nebulae. In recent years, catadioptric telescope technology has continued to advance. For example, in 2021, the Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, proposed a catadioptric imaging telescope optical system that corrects spherical aberration through lens assemblies and uses folding mirrors to refract the optical path. Most of the optical surfaces are spherical, resulting in high image quality and low manufacturing cost. In 2022, Shenzhen Qianhai Dawang Technology Co., Ltd. designed a pillar-type catadioptric sightseeing telescope with a tube length only 2-3 times the aperture, achieving a combination of large aperture, long focal length, and portability.

[0003] However, there is still room for improvement in the performance of these existing catadioptric telescopes in various aspects. Summary of the Invention

[0004] In view of this, the present invention proposes a catadioptric telescope system that can image catadioptric reflections in the wavelength range of 0.9um-1.7um, and features wide band, large aperture and high resolution.

[0005] The specific technical solution of the present invention is as follows:

[0006] A catadioptric telescope system includes a secondary mirror M2, a primary mirror M1, a meniscus lens A, a biconcave negative lens B, a biconvex positive lens C, and a meniscus lens D arranged in sequence. The primary mirror M1 has a light aperture in the center. Light rays are reflected by the primary mirror M1 to the secondary mirror M2, then reflected again by the secondary mirror M2 and pass through the light aperture, and finally pass through the meniscus lens A, the biconcave negative lens B, the biconvex positive lens C, and the meniscus lens D in sequence.

[0007] Furthermore, the meniscus positive lens A is made of heavy barium flint glass, the biconcave negative lens B is made of heavy flint glass, the biconvex positive lens C is made of heavy crown glass, and the meniscus positive lens D is made of heavy lanthanum flint glass.

[0008] Furthermore, the meniscus positive lens A is made of H-ZBAF3 glass, the biconcave negative lens B is made of H-ZF52N glass, the biconvex positive lens C is made of H-ZK9 glass, and the meniscus positive lens D is made of H-ZLAF55F glass.

[0009] Furthermore, the focal length f of the primary reflecting mirror M1 M1 Meets the requirement of 600mm <f M1<800mm.

[0010] Furthermore, the focal length f of the primary reflecting mirror M2 M2 Meets: -150mm <f M2 <-500mm.

[0011] Furthermore, the focal length f of the meniscus lens A A Meets the requirement of 150mm <f A <200mm.

[0012] Furthermore, the focal length f of the biconcave negative lens B B Meets the following requirements: -220mm <f B <-180mm.

[0013] Furthermore, the focal length f of the biconvex positive lens C C Meets the requirement of 150mm <f C <200mm.

[0014] Furthermore, the focal length f of the meniscus lens D D Meets: -200mm <f D <-150mm.

[0015] The catadioptric telescope system of the present invention can achieve the following beneficial results:

[0016] Wavelength used: 900-1700nm;

[0017] Image-sized MTF: >0.4@50lp / mm;

[0018] F-number: F / # = 2.6;

[0019] Focal length: 760mm;

[0020] Distortion: less than 0.8%;

[0021] Linear light blocking ratio: >0.4;

[0022] RMS wavefront error: <0.18λ. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the optical system structure of the present invention;

[0025] Figure 2 The graph shows the RMS wavefront variation with field of view in the range of 0.9µm-1.7µm for Example 1.

[0026] Figure 3 This is a graph showing the MTF variation in Example 1;

[0027] Figure 4 This is the lateral chromatic aberration diagram of Example 2 in the 900-1700nm range;

[0028] Figure 5 This is a graph showing the variation of RMS wavefront aberration with wavelength under different fields of view in Example 2.

[0029] Figure 6 This is a graph showing the MTF variation in Example 3;

[0030] Figure 7 The field curvature and distortion curves are from Example 3.

[0031] In the diagram: 1-reflecting secondary mirror M2, 2-reflecting primary mirror M1, 3-meniscus positive lens A, 4-biconcave negative lens B, 5-biconvex positive lens C, 6-meniscus positive lens D. Detailed Implementation

[0032] 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.

[0033] Example 1

[0034] See optical structure Figure 1 In this embodiment, a catadioptric telescope system includes a secondary mirror M2, a primary mirror M1, a meniscus lens A, a biconcave negative lens B, a biconvex positive lens C, and a meniscus lens D arranged in sequence. The primary mirror M1 has a light aperture in the middle. Light is reflected by the primary mirror M1 to the secondary mirror M2, then reflected by the secondary mirror M2 and passed through the light aperture, and finally passes through the meniscus lens A, the biconcave negative lens B, the biconvex positive lens C, and the meniscus lens D in sequence.

[0035] The meniscus positive lens A is made of heavy barium flint glass, the biconcave negative lens B is made of heavy flint glass, the biconvex positive lens C is made of heavy crown glass, and the meniscus positive lens D is made of heavy lanthanum flint glass. Specifically, the meniscus positive lens A is made of H-ZBAF3 glass, the biconcave negative lens B is made of H-ZF52N glass, the biconvex positive lens C is made of H-ZK9 glass, and the meniscus positive lens D is made of H-ZLAF55F glass.

[0036] In this embodiment, the focal length f of the primary reflecting mirror M1 is... M1 Satisfy: f M1 =661.39mm.

[0037] In this embodiment, the focal length f of the primary mirror M2 is... M2 Satisfy: f M2 = -351.4mm.

[0038] In this embodiment, the focal length f of the meniscus lens A is... A Satisfy: f A =175.45mm.

[0039] In this embodiment, the focal length f of the biconcave negative lens B is... B Satisfy: f B = -197.07mm.

[0040] In this embodiment, the focal length fC of the biconvex positive lens C satisfies: fC = 164.46 mm.

[0041] In this embodiment, the focal length fD of the meniscus lens D satisfies: f D = -173.80mm.

[0042] The distribution and detailed parameters of the catadioptric telescope system in this embodiment are shown in Table 1.

[0043] Table 1. Lens distribution and detailed parameters in Example 1

[0044] Surface serial number radius / mm Thickness / mm Material Component number 1 unlimited 400.00 2 -1322.78 -388.31 MIRROR Primary mirror M1 3 -702.80 408.31 MIRROR Secondary mirror M2 4 86.60 16.02 H-ZBAF3 Meniscus lens A 5 349.29 10.17 6 -247.95 6.00 H-ZF52N Biconcave negative lens B 7 446.84 97.37 8 340.66 11.18 H-ZK9 Biconvex positive lens C 9 -138.54 60.96 10 -31.30 5.00 H-ZLAF55F Meniscus lens D 11 -43.20 35.00

[0045] The catadioptric telescope system of this embodiment can achieve the following technical specifications:

[0046] Wavelength used: 900-1700nm.

[0047] RMS wavefront error: <0.17λ, such as Figure 2 As shown, within the wavelength range, the RMS wavefront error is close to the diffraction limit.

[0048] Image square MTF: >0.45@50lp / mm, such as Figure 3As shown, this frequency is the same as the requirement for CCD.

[0049] F-number: F / # = 2.6.

[0050] Focal length: 760mm.

[0051] Distortion: 0.67%.

[0052] Linear light blocking ratio: 0.45.

[0053] Example 2

[0054] See optical structure Figure 1 In this embodiment, a catadioptric telescope system includes a secondary mirror M2, a primary mirror M1, a meniscus lens A, a biconcave negative lens B, a biconvex positive lens C, and a meniscus lens D arranged in sequence. The primary mirror M1 has a light aperture in the middle. Light is reflected by the primary mirror M1 to the secondary mirror M2, then reflected by the secondary mirror M2 and passed through the light aperture, and finally passes through the meniscus lens A, the biconcave negative lens B, the biconvex positive lens C, and the meniscus lens D in sequence.

[0055] The meniscus positive lens A is made of heavy barium flint glass, the biconcave negative lens B is made of heavy flint glass, the biconvex positive lens C is made of heavy crown glass, and the meniscus positive lens D is made of heavy lanthanum flint glass. Specifically, the meniscus positive lens A is made of H-ZBAF3 glass, the biconcave negative lens B is made of H-ZF52N glass, the biconvex positive lens C is made of H-ZK9 glass, and the meniscus positive lens D is made of H-ZLAF55F glass.

[0056] In this embodiment, the focal length f of the primary reflecting mirror M1 is... M1 Satisfy: f M1 =661_39mm.

[0057] In this embodiment, the focal length f of the primary mirror M2 is... M2 Satisfy: f M2 = -350.4mm.

[0058] In this embodiment, the focal length f of the meniscus lens A is... A Satisfy: f A =174.45mm.

[0059] In this embodiment, the focal length f of the biconcave negative lens B is... B Satisfy: f B = -194.07mm.

[0060] In this embodiment, the focal length f of the biconvex positive lens C is... C Satisfy: f C =169.06mm.

[0061] In this embodiment, the focal length f of the meniscus lens D is... D Satisfy: f D = -177.80mm.

[0062] The distribution and detailed parameters of the catadioptric telescope system in this embodiment are shown in Table 2.

[0063] Table 2. Lens distribution and detailed parameters in Example 2

[0064] Surface serial number radius / mm Thickness / mm Material Component number 1 unlimited 400.00 2 -1321.78 -389.31 MIRROR Primary mirror M1 3 -700.80 407.31 MIRROR Secondary mirror M2 4 86.40 16.22 H-ZBAF3 Meniscus lens A 5 349.09 10.12 6 -247.85 6.15 H-ZF52N Biconcave negative lens B 7 446.74 97.27 8 340.76 10.18 H-ZK9 Biconvex positive lens C 9 -138.64 60.86 10 -31.60 5.10 H-ZLAF55F Meniscus lens D 11 -43.14 34.90

[0065] The catadioptric telescope system of this embodiment can achieve the following technical specifications:

[0066] Wavelength used: 900-1700nm.

[0067] Vertical color difference: less than 6µm, such as Figure 4 As shown.

[0068] RMS wavefront error: <0.14λ, such as Figure 5 As shown, they are all close to the diffraction limit.

[0069] Image-sized MTF: >0.5@35lp / mm.

[0070] F-number: F / # = 2.6.

[0071] Focal length: 760mm.

[0072] Distortion: 0.68%.

[0073] Linear light blocking ratio: 0.45.

[0074] Example 3

[0075] See optical structure Figure 1 In this embodiment, a catadioptric telescope system includes a secondary mirror M2, a primary mirror M1, a meniscus lens A, a biconcave negative lens B, a biconvex positive lens C, and a meniscus lens D arranged in sequence. The primary mirror M1 has a light aperture in the middle. Light is reflected by the primary mirror M1 to the secondary mirror M2, then reflected by the secondary mirror M2 and passed through the light aperture, and finally passes through the meniscus lens A, the biconcave negative lens B, the biconvex positive lens C, and the meniscus lens D in sequence.

[0076] The meniscus positive lens A is made of heavy barium flint glass, the biconcave negative lens B is made of heavy flint glass, the biconvex positive lens C is made of heavy crown glass, and the meniscus positive lens D is made of heavy lanthanum flint glass. Specifically, the meniscus positive lens A is made of H-ZBAF3 glass, the biconcave negative lens B is made of H-ZF52N glass, the biconvex positive lens C is made of H-ZK9 glass, and the meniscus positive lens D is made of H-ZLAF55F glass.

[0077] In this embodiment, the focal length f of the primary reflecting mirror M1 is... M1 Satisfy: f M1 =661.39mm.

[0078] In this embodiment, the focal length f of the primary mirror M2 is... M2 Satisfy: f M2 = -351.4mm.

[0079] In this embodiment, the focal length f of the meniscus lens A is... A Satisfy: f A =175.45mm.

[0080] In this embodiment, the focal length f of the biconcave negative lens B is... B Satisfy: f B = -197.07mm.

[0081] In this embodiment, the focal length f of the biconvex positive lens C is... C Satisfy: f C =164.06mm.

[0082] In this embodiment, the focal length f of the meniscus lens D is... D Satisfy: f D = -173.80mm.

[0083] The distribution and detailed parameters of the catadioptric telescope system in this embodiment are shown in Table 3.

[0084] Table 3. Lens distribution and detailed parameters in Example 3

[0085] Surface serial number radius / mm Thickness / mm Material Component number 1 unlimited 400.00 2 -1323.30 -388.37 MIRROR Primary mirror M1 3 -703.20 408.36 MIRROR Secondary mirror M2 4 86.71 16.03 H-ZBAF3 Meniscus lens A 5 352.14 10.17 6 -246.47 6.00 H-ZF52N Biconcave negative lens B 7 443.45 96.01 8 343.26 11.24 H-ZK9 Biconvex positive lens C 9 -139.76 62.19 10 -31.31 5.00 H-ZLAF55F Meniscus lens D 11 -43.06 35.00

[0086] The catadioptric telescope system of this embodiment can achieve the following technical specifications:

[0087] Wavelength used: 900-1700nm.

[0088] RMS wavefront error: <0.17λ.

[0089] Image-sized MTF: >0.4@50lp / mm, such as Figure 6 As shown.

[0090] F-number: F / # = 2.6.

[0091] Focal length: 760mm.

[0092] Distortion: 0.65%, such as Figure 7 As shown.

[0093] Linear light blocking ratio: 0.45.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A catadioptric telescope system, characterized in that: It includes a secondary mirror M2, a primary mirror M1, a meniscus lens A, a biconcave negative lens B, a biconvex positive lens C, and a meniscus lens D arranged in sequence. The primary mirror M1 has a light aperture in the middle. Light rays are reflected by the primary mirror M1 to the secondary mirror M2, then reflected by the secondary mirror M2 and passed through the light aperture, and finally pass through the meniscus lens A, the biconcave negative lens B, the biconvex positive lens C, and the meniscus lens D in sequence.

2. The catadioptric telescope system as described in claim 1, characterized in that: The meniscus positive lens A is made of heavy barium flint glass, the biconcave negative lens B is made of heavy flint glass, the biconvex positive lens C is made of heavy crown glass, and the meniscus positive lens D is made of heavy lanthanum flint glass.

3. The catadioptric telescope system as described in claim 1, characterized in that: The meniscus positive lens A is made of H-ZBAF3 glass, the biconcave negative lens B is made of H-ZF52N glass, the biconvex positive lens C is made of H-ZK9 glass, and the meniscus positive lens D is made of H-ZLAF55F glass.

4. The catadioptric telescope system as described in claim 1, characterized in that: The focal length f of the primary mirror M1 M1 Meets the requirement of 600mm <f M1 <800mm.

5. The catadioptric telescope system as described in claim 1, characterized in that: The focal length f of the primary mirror M2 M2 Meets: -150mm <f M2 <-500mm.

6. The catadioptric telescope system as described in claim 1, characterized in that: The focal length f of the meniscus lens A A Meets the requirement of 150mm <f A <200mm.

7. The catadioptric telescope system as described in claim 1, characterized in that: The focal length f of the biconcave negative lens B B Meets the following requirements: -220mm <f B <-180mm.

8. The catadioptric telescope system as described in claim 1, characterized in that: The focal length f of the biconvex positive lens C C Meets the requirement of 150mm <f C <200mm.

9. The catadioptric telescope system as described in claim 1, characterized in that: The focal length f of the meniscus lens D D Meets: -200mm <f D <-150mm.

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