阅读说明：本技术 双焦距系统折反式天文望远镜 (Catadioptric astronomical telescope with dual focal length system ) 是由 赵跃东 末永豊 于 2019-09-23 设计创作，主要内容包括：本专利提供一种双焦距系统折反式天文望远镜,它通过特殊光路系统很好地校正了轴上和轴外像差,镜筒长度短,实现了在一个镜筒上满足长焦和短焦。它包括位于同一光轴上的主折射镜一、主折射镜二、主反射镜、主折射镜三；主折射镜一采用中心开孔的平凸正透镜,主折射镜一中心开孔处安装主折射镜三的镜座,主折射镜三的镜座上可拆卸连接有折反镜组或者会聚镜组；主折射镜二采用平凹负透镜；主反射镜是凹面为反射面的平凹镜,中心开孔,主反射镜中心开孔处设置会聚透镜；折反镜组是由副折射镜和副反射镜两者集成的一个组件；使用长焦距的情况下,主折射镜二在光路中折射三次,主折射镜三和副折射镜折射两次,使用短焦距的情况下,主折射镜二折射两次。(The patent provides a bifocal system refraction and reflection type astronomical telescope, which corrects the on-axis and off-axis aberration well through a special optical path system, has short lens cone length, and realizes that long focus and short focus are satisfied on one lens cone. The device comprises a primary refractor I, a primary refractor II, a primary reflector and a primary refractor III which are positioned on the same optical axis; the first primary refractor adopts a plano-convex positive lens with a central hole, a third primary refractor seat is arranged at the central hole of the first primary refractor, and a catadioptric group or a convergent group is detachably connected to the third primary refractor seat; the second primary refractor adopts a plano-concave negative lens; the main reflector is a plano-concave mirror with a concave surface as a reflecting surface, the center of the main reflector is provided with an opening, and a convergent lens is arranged at the center of the opening of the main reflector; the catadioptric group is an assembly formed by integrating a secondary refractor and a secondary reflector; under the condition of using the long focal length, the second primary refractor refracts three times in the light path, the third primary refractor refracts twice with the secondary refractor, and under the condition of using the short focal length, the second primary refractor refracts twice.)

1. The catadioptric astronomical telescope of the bifocal system, its characteristic is: the device comprises a primary refractor I (1), a primary refractor II (2), a primary reflecting mirror (3) and a primary refractor III (4) which are positioned on the same optical axis; the primary refractor I (1) adopts a plano-convex positive lens with a central opening, a lens base of a primary refractor III (4) is arranged at the central opening of the primary refractor I (1), and a catadioptric group or a converging group is detachably connected to the lens base of the primary refractor III (4); the second primary refractor (2) adopts a plano-concave negative lens; the main reflector (3) is a plano-concave mirror with a concave surface as a reflecting surface, the center of the plano-concave mirror is provided with an opening, and a convergent lens (7) is arranged at the central opening of the main reflector (3);

the catadioptric lens group is an assembly formed by integrating a secondary refractor (5) and a secondary reflector (6);

During long-focus observation, a catadioptric lens group is connected to a lens seat of a primary refractor III (4), light rays sequentially reach a primary reflector (3) through a primary refractor I (1) and a primary refractor II (2), the light rays are reflected by the primary reflector (3), then reach an auxiliary reflector (6) through the primary refractor II (2), the primary refractor III (4) and an auxiliary refractor (5), the light rays reflected by the auxiliary reflector (6) are converged to a focal plane behind a telescope through a converging lens (7) after passing through the auxiliary refractor (5), the primary refractor III (4) and the primary refractor II (2);

During short-focus observation, a converging lens group is connected to a lens base of the primary refractor III (4), light sequentially reaches the primary reflector (3) through the primary refractor I (1) and the primary refractor II (2), and then enters the converging lens group through the primary refractor II (2) and the primary refractor III (4) after passing through reflected light of the primary reflector (3), and is converged to a front image focal plane (13) of the telescope through the converging lens group.

2. The dual focal length system catadioptric astronomical telescope of claim 1, wherein: the converging lens group is an assembly formed by integrating a first converging lens (11) and a second converging lens (12).

3. The bifocal system catadioptric astronomical telescope of claim 1 or 2, wherein: the main mirror (3) is movable along an optical axis.

4. The dual focal length system catadioptric astronomical telescope of claim 1, wherein: the light emitted by the convergent lens (7) is converged to a focal plane at the rear image side of the telescope through the steering of the steering mirror.

5. The dual focal length system catadioptric astronomical telescope of claim 1, wherein: the digital camera is used for photographing, and the focal plane at the rear image side of the telescope is the position of the target surface of the digital camera.

6. The dual focal length system catadioptric astronomical telescope of claim 1, wherein: it also includes CCD receiver for observation, the focal plane of the front image of the telescope is the target surface position of the CCD receiver.

Technical Field

The technology relates to an astronomical telescope, in particular to a double-focal-length system catadioptric astronomical telescope with switchable long focus and short focus.

Background

Conventional catadioptric astronomical telescopes are of the schmidt and macsutov types. Schmidt adopts an aspheric thin lens as a correcting mirror, is matched with a spherical reflector, has strong light power and large field of view, is suitable for shooting large-area photos in a sky area, particularly has a remarkable shooting effect on dark and weak stars, and has the defects of high aspheric processing difficulty and high price. The macstoff type uses a meniscus lens as a correction lens, all its surfaces are spherical, easy to process, and has the disadvantage of small field of view and high demand for glass. In a conventional catadioptric telescope, each lens barrel can only satisfy a telescope structure with one focal length, such as: under the same caliber, the short focal length has large numerical aperture, high brightness and clear image, and is most suitable for observing dark star clouds and star groups; the long focal length is high, so that the fine structure on the surface of the planet can be seen, and if the two observations are simultaneously met, two telescopes are needed.

Disclosure of Invention

The purpose of this patent is to provide a bifocal system refraction and reflection type astronomical telescope, its whole lenses are the sphere, and processing is easy, and it has corrected epaxial and off-axis aberration well through special optical path system, and lens cone length is short to realized satisfying long focus and short focus on a lens cone, had big visual field simultaneously, hi-lite, high magnification and high resolution's effect.

The technical scheme adopted by the patent is that the dual-focal-length system catadioptric astronomical telescope comprises a primary refractor I1, a primary refractor II 2, a primary reflector 3 and a primary refractor III 4 which are positioned on the same optical axis; the primary refractor I1 adopts a plano-convex positive lens with a central opening, a lens base of a primary refractor III 4 is arranged at the central opening of the primary refractor I1, and a catadioptric group or a convergent lens group is detachably connected to the lens base of the primary refractor III 4; the second primary refractor 2 adopts a plano-concave negative lens; the main reflector 3 is a plano-concave mirror with a concave surface as a reflecting surface, the center of the main reflector is provided with an opening, and a convergent lens 7 is arranged at the center of the opening of the main reflector 3;

The catadioptric group is an assembly formed by integrating a secondary refractor 5 and a secondary reflector 6;

During long-focus observation, a catadioptric group is connected to a lens seat of a primary refractor III 4, light sequentially reaches a primary reflector 3 through a primary refractor I1 and a primary refractor II 2, passes through light reflected by the primary reflector 3, then reaches an auxiliary reflector 6 through the primary refractor II 2, the primary refractor III 4 and an auxiliary refractor 5, and light reflected by the auxiliary reflector 6 is converged to a focal plane of a rear image of a telescope through a converging lens 7 after passing through the auxiliary refractor 5, the primary refractor III 4 and the primary refractor II 2;

During short-focus observation, a converging lens group is connected to a lens base of the primary refractor III 4, light sequentially reaches the primary reflector 3 through the primary refractor I1 and the primary refractor II 2, and then enters the converging lens group through the primary refractor II 2 and the primary refractor III 4 after being reflected by the primary reflector 3, and is converged to the front image space focal plane 13 of the telescope through the converging lens group.

As a further improvement of the catadioptric astronomical telescope with the dual focal length system, the converging lens group is an assembly formed by integrating a first converging lens 11 and a second converging lens 12.

As a further improvement to the above-described bifocal catadioptric astronomical telescope, the primary mirror 3 is movable along the optical axis.

as a further improvement of the double-focal-length system catadioptric astronomical telescope, the telescope further comprises a steering mirror, and light rays emitted by the convergent lens 7 are converged to an image focal plane 9 behind the telescope through the steering of the steering mirror.

as a further improvement of the catadioptric astronomical telescope with the double focal length system, the catadioptric astronomical telescope further comprises a digital camera for taking pictures, and the focal plane at the back image side of the telescope is the target plane position 10 of the digital camera.

as a further improvement of the catadioptric astronomical telescope with the double focal length system, the telescope also comprises a CCD receiver for observation, and the focal plane 13 on the front image side of the telescope is the target plane position of the CCD receiver

The beneficial effect of this technique:

the technology is characterized in that a catadioptric lens group or a converging lens group is detachably connected to a lens base of a primary refractor III 4 positioned at a central opening of a primary refractor I1, and the catadioptric lens group or the converging lens group can be replaced according to use requirements. The long-focus system observation is realized when the catadioptric lens group is used, and the short-focus system observation is realized when the convergent lens group is used.

For a long-focus system, imaging light is introduced into the inner cavity of the lens barrel through the primary refractor I1, reaches the primary reflector 3 through the primary refractor II 2, is reflected through the primary refractor II 2 for the second time, and then reaches the secondary reflector 6 through the primary refractor III 4 and the secondary refractor 5, light coming out of the secondary reflector 6 is refracted through the secondary refractor 5 and the primary refractor III 4 for the second time, passes through the primary refractor II 2 for the third time, and finally is imaged at a rear image space focal plane (a visual observation image plane 9 or a digital camera target surface 10) of the astronomical telescope through the convergent lens 7.

The catadioptric lens group is replaced by a group of convergent lens group, so that short focal length and large numerical aperture can be realized.

under the condition of using a long focal length, the second primary refractor 2 refracts three times in a light path, the third primary refractor 4 and the secondary refractor 5 refract twice, and under the condition of using a short focal length, the second primary refractor 2 refracts twice, which is equivalent to that a symmetrical structure is used in an optical system, so that spherical aberration, coma aberration, chromatic aberration, off-axis astigmatism, field curvature, distortion and other aberrations are well eliminated.

The light path is refracted for many times, and under the condition of long focal length, the length of the lens barrel is only 1/5 of the focal length.

Drawings

FIG. 1 is a schematic diagram of a tele system;

FIG. 2 is a schematic diagram of a short focus system;

In the figure, 1 is a primary refractor-1

2 is a primary refractor two

3 is a main mirror

4 is a primary refractor III

5 is a secondary refractor

6 is a sub-reflector

7 is a converging lens

8 is a plane mirror

9 is visual observation image plane (telescope rear image square focal plane)

10 is the target surface of the digital camera (telescope back image square focal plane)

11 is a converging lens

12 is a converging lens 2

And 13 is a telescope front image space focal plane (CCD target plane).

Detailed Description

The following detailed description of the present patent refers to the accompanying drawings and detailed description.

Referring to fig. 1, a bifocal system catadioptric astronomical telescope is shown when a tele system is used.

The primary refractor 1 adopts a plano-convex positive lens, low dispersion glass is selected, the effective light-passing aperture is 200mm, the center of the primary refractor is perforated, the center of the hole and the center of the optical axis of the lens are concentric, and the two optical surfaces are plated with broadband antireflection films. The second primary refractor 2 adopts a plano-concave negative lens, low dispersion glass is selected, broadband antireflection films are plated on two optical surfaces, and light rays in the second primary refractor 2 pass through the system for three times, so that the functions of three lenses are born, off-axis aberration can be mutually offset, and the lens barrel is greatly shortened. The first primary refractor 1 and the second primary refractor 2 are both adjustable in center. The main reflector 3 is designed to be flat and concave, the concave surface is plated with a high-reflectivity aluminum film and a protective film, the reflectivity can reach 99.5%, an adjusting mechanism is arranged behind a main reflector 3 seat, the main reflector 3 is ensured to coincide with the centers of optical axes of the first main refractor 1 and the second main refractor 2, the main reflector 3 can move back and forth, and far and near targets are imaged on a primary image surface (an image surface 9 for visual observation or a target surface 10 of a digital camera). The third primary refractor 4 is a negative meniscus lens, the secondary refractor 5 is a positive meniscus lens, the optical surfaces of the third primary refractor and the secondary refractor are coated with a broadband antireflection film, and light rays pass through the third primary refractor 4 and the secondary refractor 5 twice, so that off-axis aberration can be mutually counteracted, and the size of the lens barrel can be shortened. The secondary reflector 6 is of a plano-convex structure, and a high-reflection aluminum film and a protective film are plated on the convex surface. The lens base of the primary refractor III 4 is arranged at the central hole of the primary refractor I1, the secondary refractor 5 and the secondary reflector 6 are integrated on one component (namely, the catadioptric group), and are connected with the lens base of the primary refractor III 4 through threads, and the catadioptric group can be conveniently replaced by the convergent catadioptric group through threaded connection, so that the short-focus system can work. The converging lens 7 is a biconvex positive lens and converges the imaging light beam of the front system to the rear image focal plane of the telescope. The plane mirror 8 deflects the imaging light by 90 deg., which makes the instrument more ergonomic. The plane reflector 8 can also be replaced by a right-angle prism or a half-pentagonal prism, the half-pentagonal prism forms a positive image, and a target on the observation ground can be selected. If a digital camera is needed for taking a picture, a camera interface can be selected to replace the plane reflectors 8 and 10 to be the target surfaces of the digital camera.

Referring to fig. 2, a dual focal length system catadioptric astronomical telescope is shown when a short focal length system is used.

the primary refractor 1 adopts a plano-convex positive lens, low dispersion glass is selected, the effective light-passing aperture is 200mm, the center of the primary refractor is perforated, the center of the hole and the center of the optical axis of the lens are concentric, and the two optical surfaces are plated with broadband antireflection films. The second primary refractor 2 adopts a plano-concave negative lens, low dispersion glass is selected, the two optical surfaces are coated with broadband antireflection films, light rays in the second primary refractor 2 pass through the system twice, and the functions of the two lenses are born, so that off-axis aberration can be mutually offset, and the lens barrel is greatly shortened. The first primary refractor 1 and the second primary refractor 2 are both adjustable in center. The main reflector 3 is designed to be plano-concave, the concave surface is plated with a high-reflectivity aluminum film and a protective film, the reflectivity can reach 99.5%, an adjusting mechanism is arranged behind a reflector base of the main reflector 3, the main reflector 3 is guaranteed to coincide with the centers of optical axes of the first main refractor 1 and the second main refractor 2, the main reflector 3 can move back and forth, and far and near targets are made to be imaged on a focal plane (a CCD target surface 13) in the front image space. The converging lens group consists of a converging lens I11 and a converging lens II 12, wherein the converging lens I11 is a positive meniscus thick lens, the converging lens II 12 is a positive meniscus lens, and optical surfaces of the converging lens I11 and the converging lens II 12 are coated with a broadband antireflection film, so that light is focused on a CCD target surface 13 to form an image. The first converging lens 11 and the second converging lens 12 are integrated on one component (namely a converging lens group), and are connected with the lens base of the third primary refractor 4 through threads, and the converging lens group can be conveniently replaced by a catadioptric lens group through threaded connection, so that the work of a long-focus system is realized.

The aperture of the astronomical telescope is 200mm, the long focal length is 2000mm, and the short focal length is 1000 mm. In the tele mode, the length of the barrel is only 1/5 of the focal length (the conventional configuration is 1/3 of the focal length).