Off-axis star guider, astronomical telescope star guiding assembly and astronomical telescope
By combining the focusing device with the optical path coupler, the problems of precision and cumbersome operation when adjusting the position of the prism or mirror in the existing off-axis star guide are solved, and precise adjustment and simple operation without disassembling the equipment are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU ASTROASIS VISION TECH CO LTD
- Filing Date
- 2025-05-29
- Publication Date
- 2026-05-12
AI Technical Summary
Existing off-axis star guides cannot be precisely adjusted when adjusting the position of prisms or reflectors, and the operation is cumbersome, requiring the equipment to be disassembled for adjustment.
It adopts a combination structure of a focuser and an optical coupler. The focuser drives the optical coupler and the guide camera to move synchronously, so as to achieve precise adjustment of the position of the prism or reflector without disassembling the equipment.
It enables precise adjustment of the prism or reflector position, is easy to operate, requires no additional tools, and improves efficiency and accuracy.
Smart Images
Figure CN224232038U_ABST
Abstract
Description
Technical Field
[0001] This utility model specifically relates to an off-axis guide, a guide component for an astronomical telescope, and an astronomical telescope, belonging to the field of astronomical observation and photography technology. Background Technology
[0002] In astronomical observation and deep-sky photography, a guiding system is typically used to correct the telescope's pointing in real time to compensate for star drift caused by Earth's rotation, telescope tracking errors, or mechanical deformation. One commonly used technique is the off-axis guide (OAG). The off-axis guide extracts a portion of the light from the edge of the field of view for guiding the star without affecting the main imaging optical path, thus achieving high-precision telescope tracking correction. Compared to traditional independent guide mirrors or coaxial guides, OAGs offer advantages such as compact structure, shared optical path, and reduced mechanical deformation errors, and are widely used in deep-sky photography, planetary observation, and other fields.
[0003] The core principle of an off-axis guide is to use a beam splitter or mirror to extract a small portion of light from the edge region of the main imaging path and guide it to the guide camera. Because the guide path and the main imaging path share the same optical system, the guiding error caused by mechanical deformation in traditional guide mirrors can be avoided.
[0004] A typical off-axis guide consists of the following components: Main optical path interface: connects the telescope to the main camera (such as a DSLR or astronomical CCD). Beam splitter / mirror: located at the edge of the optical path, not affecting the main imaging area. Guide camera interface: usually an M42 thread or a 1.25-inch standard interface, compatible with mainstream guide cameras. Focusing mechanism: some high-end OAGs are equipped with a screw-type focus mount for precise focusing. Off-axis guides use prisms or mirrors to extract a small portion of light from the edge of the main optical path to guide the star. If the prism or mirror is too close to the center of the optical path, it will obstruct the main camera; if it is too close to the edge, the poor image quality and low signal-to-noise ratio of the edge light will affect the guiding effect. Therefore, the position of the prism or mirror needs to be precisely adjusted, as close to the center of the optical path as possible, while avoiding obstruction of the main camera.
[0005] In most off-axis guides, the prism or mirror is mounted on a cylindrical structure (prism post), which is fixed to the main structure of the off-axis guide with screws. When the prism position needs to be adjusted, the fixing screws are loosened, and then the position of the prism post relative to the center of the optical path is manually moved to adjust the prism or mirror position. This method has two drawbacks: because the prism post is moved manually, the position of the prism or mirror cannot be precisely adjusted; and for ease of operation when moving the prism post, the off-axis guide usually needs to be removed from the telescope or other equipment before adjusting the prism or mirror position, making the process cumbersome. While some off-axis guides have a double-helix focusing mechanism to adjust the position of the guiding camera, this mechanism cannot be used to adjust the position of the prism or mirror. Utility Model Content
[0006] The main objective of this invention is to provide an off-axis guide, a guide assembly for an astronomical telescope, and an astronomical telescope, thereby overcoming the shortcomings of the prior art.
[0007] To achieve the aforementioned objectives, the technical solution adopted by this utility model includes:
[0008] A first aspect of this utility model provides an off-axis star guide for extracting a portion of light from the edge region of the main imaging optical path and guiding it to a star guide camera. It includes: a connecting body, a focusing mechanism, and an optical path coupler. The focusing mechanism is fixedly connected to the connecting body, and the optical path coupler is movably coupled to the connecting body and the focusing mechanism.
[0009] The focusing device and the optical coupler are configured together to form a guiding optical path. The connecting body is used to connect to the telescope and / or the main camera and to access the main imaging optical path between the telescope and the main camera. The optical coupler is used to guide a portion of the light in the main imaging optical path into the guiding optical path. The optical coupler has a first connection structure, which is used to be detachably connected to the guiding camera. When the optical coupler is connected to the guiding camera, the optical coupler and the guiding camera can be synchronously driven by the focusing device to move along the axis of the focusing device, thereby changing the radial position of the optical coupler in the main imaging optical path.
[0010] A second aspect of this utility model provides a guiding assembly for an astronomical telescope, comprising: a guiding camera and the aforementioned off-axis guiding device, wherein a portion of the guiding camera is fitted inside the focusing device and is detachably connected to the focusing device, and the guiding camera is provided with a second connecting structure, the second connecting structure being detachably connected to a first connecting structure located on the optical path coupler;
[0011] When the first connection structure and the second connection structure are separated, and the guide camera is connected to the focuser, the guide camera can be driven by the focuser to move along the axis of the focuser independently; when the first connection structure and the second connection structure are connected, and the guide camera is connected to the focuser, the guide camera and the optical coupler can be driven by the focuser to move along the axis of the focuser simultaneously.
[0012] A third aspect of this utility model provides an astronomical telescope having the aforementioned off-axis guide or the aforementioned astronomical telescope guide assembly.
[0013] Compared with the prior art, the advantages of this utility model include: the astronomical telescope guiding component provided by the embodiment of this utility model, wherein the focusing device, as part of the off-axis guiding device, can not only be used to focus the guiding camera, but also to precisely adjust the position of the prism or reflector. When adjusting the position of the prism or reflector using the focusing device, it can be operated without removing the off-axis guiding device from the telescope or other equipment, without the need for other additional tools, making it convenient to use, and the position of the prism or reflector can be accurately determined. Attached Figure Description
[0014] To more clearly illustrate the technical solutions in the embodiments of this application 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 recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0015] Figure 1 This is a schematic diagram of the structure of a guide assembly for an astronomical telescope provided in a typical embodiment of this utility model;
[0016] Figure 2 This is a side view of a guide assembly for an astronomical telescope provided in a typical embodiment of this utility model;
[0017] Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure of the middle BB section;
[0018] Figure 4 This is a schematic diagram of the guiding camera in a typical embodiment of this utility model;
[0019] Figure 5 This is a schematic diagram of the optical coupler in a typical embodiment of this utility model;
[0020] Figure 6This is a schematic diagram of the structure of the guide camera and the optical coupler in a typical embodiment of this utility model. Detailed Implementation
[0021] In view of the shortcomings of the prior art, the inventor of this case, through long-term research and extensive practice, has come up with the technical solution of this utility model. The following will further explain the technical solution, its implementation process, and its principles.
[0022] A first aspect of this utility model provides an off-axis star guide for extracting a portion of light from the edge region of the main imaging optical path and guiding it to a star guide camera. It includes: a connecting body, a focusing mechanism, and an optical path coupler. The focusing mechanism is fixedly connected to the connecting body, and the optical path coupler is movably coupled to the connecting body and the focusing mechanism.
[0023] The focusing device and the optical coupler are configured together to form a guiding optical path. The connecting body is used to connect to the telescope and / or the main camera and to access the main imaging optical path between the telescope and the main camera. The optical coupler is used to guide a portion of the light in the main imaging optical path into the guiding optical path. The optical coupler has a first connection structure, which is used to be detachably connected to the guiding camera. When the optical coupler is connected to the guiding camera, the optical coupler and the guiding camera can be synchronously driven by the focusing device to move along the axis of the focusing device, thereby changing the radial position of the optical coupler in the main imaging optical path.
[0024] Furthermore, the connecting body has a first channel extending along its own axis. When the connecting body is connected to the telescope and / or the main camera, the first channel is located on the main imaging optical path of the telescope and the main camera. The focusing device has a second channel extending along its own axis. The focusing device is used to connect to the guiding camera and to focus the guiding camera. The optical path coupler has a third channel extending along its own axis. One end of the optical path coupler is disposed in the second channel, and the other end is disposed in the first channel. The third channel is connected to the first channel and the second channel. The optical path coupler, the third channel, and the second channel together form the guiding optical path.
[0025] Furthermore, the optical path coupler includes a mounting frame and an optical path beam splitter. The first end of the mounting frame is disposed in the first channel, the second end is disposed in the second channel, the third channel is disposed inside the mounting frame, the optical path beam splitter is disposed at the first end of the mounting frame, and the first connecting structure is located at the second end.
[0026] Furthermore, the optical path beam-splitting element includes a beam-splitting prism or a reflector.
[0027] Furthermore, the connecting body is a ring structure, and the connecting body encloses to form the first channel. The focusing device is arranged radially on the outside of the connecting body, and the axial direction of the focusing device is parallel to the radial direction of the connecting body. The connecting body is also provided with a fourth channel extending radially, which communicates with the first channel and the second channel. The portion of the mounting bracket near the first end extends into the first channel from the fourth channel. The radial dimension of the second end is larger than the radial dimension of the other portions. The second end also serves as a limiting structure to restrict the distance the optical coupler moves radially along the connecting body.
[0028] Furthermore, the connecting body is also provided with a first locking screw, which is threadedly connected to the connecting body and is used to lock or unlock the optical coupler.
[0029] Furthermore, the first connection structure is a threaded structure or a mortise and tenon structure.
[0030] Furthermore, the focusing device is provided with a dial indicating the focusing stroke, and the dial is provided with stroke scale lines indicating the focusing stroke.
[0031] Furthermore, the focusing device is a double-helix focusing device.
[0032] A second aspect of this utility model provides a guiding assembly for an astronomical telescope, comprising: a guiding camera and the aforementioned off-axis guiding device, wherein a portion of the guiding camera is fitted inside the focusing device and is detachably connected to the focusing device, and the guiding camera is provided with a second connecting structure, the second connecting structure being detachably connected to a first connecting structure located on the optical path coupler;
[0033] When the first connection structure and the second connection structure are separated, and the guide camera is connected to the focuser, the guide camera can be driven by the focuser to move along the axis of the focuser independently; when the first connection structure and the second connection structure are connected, and the guide camera is connected to the focuser, the guide camera and the optical coupler can be driven by the focuser to move along the axis of the focuser simultaneously.
[0034] Furthermore, the astronomical telescope guide assembly also includes a second locking screw, which is disposed on the outer cylinder of the focuser and is used at least to lock or unlock the guide camera, the outer cylinder being capable of telescoping along its own axis.
[0035] Furthermore, when the guide camera is not connected to the focuser, the guide camera can generate relative linear motion along the axis of the focuser and / or relative rotational motion around the axis of the focuser.
[0036] Furthermore, the first connecting structure and the second connecting structure are connected by mortise and tenon joints or threaded connections.
[0037] Furthermore, the second connection structure is a mortise and tenon structure or a threaded structure.
[0038] Furthermore, the second connection structure is located at the end of the guide camera near the optical coupler.
[0039] A third aspect of this utility model provides an astronomical telescope having the aforementioned off-axis guide or the aforementioned astronomical telescope guide assembly.
[0040] The following will provide a further explanation of the technical solution, its implementation process, and its principles, in conjunction with the accompanying drawings and specific implementation examples.
[0041] In a typical implementation case, please refer to Figure 1 and Figure 2 A guiding assembly for an astronomical telescope includes a guiding camera 100 and an off-axis guiding device 200. The guiding camera 100 is detachably mounted on the off-axis guiding device 200, which is detachably mounted on the telescope. The off-axis guiding device 200 is used to extract a portion of the light from the edge region of the telescope's main imaging optical path and guide it to the guiding camera 100.
[0042] For details, please refer to Figure 3 The overall structure of the off-axis guide 200 is the same as that of the existing conventional off-axis guide 200. The off-axis guide 200 includes a connecting body 210, a focusing device 220, and an optical path coupler 230. The focusing device 220 is fixedly mounted on the connecting body 210, and the optical path coupler 230 is movably coupled with the connecting body 210. The guide camera 100 is mounted on the focusing device 220. The connecting body 210 is used to connect to the telescope and / or the main camera and to access the main imaging optical path between the telescope and the main camera. The focusing device 220 and the optical path coupler 230 are configured together to form a guide optical path. The optical path coupler 230 is used to guide part of the light in the main imaging optical path into the guide optical path. The guide camera 100 is located on the guide optical path.
[0043] More specifically, the connecting body 210 has a ring structure, forming a first channel. The focusing device 220 is fixedly disposed on the outside of the connecting body 210 along its radial direction, and its axial direction is parallel to the radial direction of the connecting body 210. The focusing device 220 has a second channel that extends along its own axial direction and is connected to the first channel. A portion of the optical coupler 230 is disposed in the second channel inside the focusing device 220, and another portion is disposed in the first channel of the connecting body 210. The optical coupler 230 has a third channel that extends along its own axial direction and is connected to the first channel and the second channel. In this configuration, the optical coupler 230, together with the third channel and the second channel, forms the guiding optical path. When the connecting body 210 is connected to the telescope and / or the main camera, the first channel is located on the main imaging optical path between the telescope and the main camera (it can also be understood that the first channel is part of the main imaging optical path). The optical coupler 230 located in the first channel can extract light from the main imaging optical path and guide this part of the light to the guiding camera 100 along the guiding optical path. The above is the basic structure for the off-axis guiding star 200 to extract part of the light from the autonomous imaging optical path and guide it to the guiding camera 100. Of course, this is also a basic structure known in the art, and its specific implementation principle will not be explained or described in detail here.
[0044] Specifically, the optical coupler 230 includes a mounting frame 231 and an optical beam splitter 232. The first end of the mounting frame 231 is disposed in the first channel, the second end is disposed in the second channel, and the third channel is disposed inside the mounting frame 231. The optical beam splitter 232 is disposed at the first end of the mounting frame 231, wherein the optical beam splitter 232 includes a beam splitter prism or a reflector, etc.
[0045] Specifically, the portion of the optical coupler 230 extending into the first channel needs to be as close as possible to the center of the optical path within the first channel (which can be understood as the axis of the first channel), while simultaneously avoiding obstructing the main imaging optical path of the main camera. Therefore, the relative position of the optical coupler 230 and the connecting body 210 needs to be adjusted. Thus, the optical coupler 230 is in movable cooperation with the connecting body 210, and the optical coupler 230 can move radially along the connecting body 210. At the same time, in order to fix the optical coupler 230 in the required position and orientation, the connecting body 210 is also provided with a first locking screw 240. The first locking screw 240 is threadedly connected to the connecting body 210, and one end of the first locking screw 240 passes through the connecting body 210 radially and abuts against the optical coupler 230. By turning the first locking screw 240, the optical coupler 230 can be locked and unlocked.
[0046] Specifically, the connecting body 210 is also provided with a fourth channel extending radially therefrom. The fourth channel communicates with the first channel and the second channel. The portion of the mounting bracket 231 near the first end extends into the first channel from the fourth channel. The radial dimension of the second end is greater than the radial dimension of the other portions. The second end also serves as a limiting structure to restrict the distance the optical coupler 230 moves radially along the connecting body 210.
[0047] If the position of the optical coupler 230 needs to be adjusted using a conventional off-axis guide 200, the focuser 220 and guide camera 100 must first be removed. For more convenient and accurate adjustment of the position of the optical coupler 230, please refer to [link to relevant documentation]. Figure 3 , Figure 4 , Figure 5 and Figure 6 In this invention, a first connecting structure 233 is provided on the optical path coupler 230, and a second connecting structure 110 is provided on the guide camera 100. The first connecting structure 233 and the second connecting structure 110 are detachably connected. When the optical path coupler 230 is connected to the guide camera 100, the optical path coupler 230 and the guide camera 100 can be synchronously driven by the focuser 220 to move along the axial direction of the focuser 220, thereby changing the radial position of the optical path coupler 230 in the main imaging optical path.
[0048] Specifically, when the first connecting structure 233 and the second connecting structure 110 are separated, and the guide camera 100 is connected to the focuser 220, the guide camera 100 can be driven by the focuser 220 to move along the axis of the focuser 220 independently; when the first connecting structure 233 and the second connecting structure 110 are connected, and the guide camera 100 is connected to the focuser 220, the guide camera 100 and the optical path coupler 230 can be driven by the focuser 220 to move along the axis of the focuser 220 simultaneously; when the guide camera 100 and the focuser 220 are not connected, the guide camera can generate relative linear motion along the axis of the focuser 220 and / or relative rotational motion around the axis of the focuser 220.
[0049] Specifically, the structure of the focusing device 220 is known in the art, and the focusing device 220 can be a double-helix focusing device, etc. Specifically, the focusing device 220 mainly includes a coaxially arranged fixed base, an inner cylinder, an outer cylinder, and a scale 221. The fixed base is fixedly arranged on the connecting body 210, and the inner cylinder is fixedly fitted with the fixed base (for example, it can be fixed by a threaded connection). The inner cylinder is arranged inside the outer cylinder, and the scale 221 is driven to move along its own axis by a transmission structure. By turning the scale 221, the outer cylinder can be driven to move along its own axis. The guide camera 100 is partially coaxially arranged inside the outer cylinder. The guide camera 100 can move along the axis of the outer cylinder and change its axial position inside the outer cylinder. The guide camera 100 is connected to the outer cylinder by a second locking screw 250. As is known to those skilled in the art, when the guide camera 100 is locked to the outer cylinder with the second locking screw 250, the guide camera 100 can be moved along the axis of the focusing device 220 by turning the scale 221, thereby achieving focusing.
[0050] As mentioned above, the second end of the mounting bracket 231 in the optical path coupler 230 is located inside the focuser 220. The first connecting structure 233 is located at the second end of the mounting bracket 231 and at one end of the guide camera 100. When the guide camera 100 moves along the axial direction of the outer cylinder, the second connecting structure 110 and the first connecting structure 233 approach each other and can connect. At this time, the optical path coupler 230 is unlocked, and the guide camera 100 and the optical path coupler 230 can be moved simultaneously by rotating the dial 221, thereby achieving accurate adjustment of the position of the optical path coupler 230.
[0051] It should be noted that the portion of the mounting bracket 231 near the first end extends into the first channel from the fourth channel, and the radial dimension of the second end is larger than the radial dimension of the other portions. The second end also serves as a limiting structure to restrict the radial movement distance of the optical coupler 230 along the connecting body 210. Specifically, the second end of the mounting bracket 231 cooperates with the fixing seat of the focusing device 220 to form a limiting structure. The fixing seat is located at the end of the focusing device 220 near the connecting body 210, that is, when the mounting bracket 231 / optical coupler 230 is in position... When the focuser 220 is at its lowest limit position, the mounting bracket 231 / optical path coupler 230 and the focuser 220 are in contact with each other, and the mounting bracket 231 / optical path coupler 230 can no longer move closer to the connecting body 210 along the axis of the focuser 220. At this time, the distance between the front end of the optical path beam splitting element 232 such as the prism in the optical path coupler 230 and the center of the optical axis of the first channel is 8mm (i.e., a known distance). At this time, the position of the optical path beam splitting element 232 can be accurately calculated according to the scale of the dial 221.
[0052] For example, the focusing stroke of the focusing device 220 is 6mm. One full rotation of the dial 221 corresponds to a 6mm focusing stroke. The dial 221 has six large graduations: 0, 1, 2, 3, 4, and 5. Therefore, for each large graduation the dial 221 rotates, the position of the optical coupler 230 is adjusted by 1mm. There are 20 small graduations between each large graduation, so each small graduation has an adjustment accuracy of 0.05mm. When starting adjustment, the focusing stroke of the focusing device 220 is set to its minimum. During adjustment, the position of the optical beam splitter 232 can be accurately calculated based on the graduations rotated by the dial 221.
[0053] Specifically, the first connecting structure 233 and the second connecting structure 110 can be connected by mortise and tenon joints or threaded connections. Specifically, the first connecting structure 233 and the second connecting structure 110 can be mortise and tenon joints or threaded connections. When the first connecting structure 233 and the second connecting structure 110 are threaded, the first connecting structure 233 can be an external thread structure on the mounting bracket 231, and the second connecting structure 110 can be an internal thread structure on one end of the guide camera 100, etc. For example, the first connecting structure 233 can be an M28.5*0.6 external thread structure, and the second connecting structure 110 can be an M28.5*0.6 internal thread structure.
[0054] The steps for adjusting the position of a prism or mirror using a dual-helix focuser are as follows:
[0055] Screw the internal thread structure at the front end of the guide camera 100 onto the external thread structure at the front end of the mounting bracket 231, thus connecting the guide camera 100 and the optical coupler 230. Loosen the first locking screw 240 of the optical coupler 230 and tighten the second locking screw 250 of the guide camera 100 on the double helix focuser. Rotate the dial 221 on the double helix focuser to raise or lower the position of the prism or reflector. After the prism or reflector is adjusted to the appropriate position, lock the optical coupler 230 with the first locking screw 240 to release the threaded connection between the guide camera 100 and the optical coupler 230. When the dial 221 on the double helix focuser is rotated, the position of the guide camera 100 is adjusted, thereby adjusting the position of the optical coupler 230 as well.
[0056] This utility model provides a star guide assembly for an astronomical telescope, in which the focusing device, as part of the off-axis star guide, can not only be used to focus the star guide camera, but also to precisely adjust the position of the prism or reflector. When adjusting the position of the prism or reflector using the focusing device, it can be operated without removing the off-axis star guide from the telescope or other equipment, without the need for any other additional tools, making it convenient to use, and the position of the prism or reflector can be accurately determined.
[0057] It should be understood that the above embodiments are merely illustrative of the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.
Claims
1. An off-axis guide for extracting a portion of light rays from the edge region of the main imaging optical path and guiding them to a guide camera, characterized in that, include: The system comprises a connecting body, a focusing device, and an optical coupler. The focusing device is fixedly connected to the connecting body, and the optical coupler is movably connected to the connecting body and the focusing device. The focusing device and the optical coupler are configured together to form a guiding optical path. The connecting body is used to connect to the telescope and / or the main camera and to access the main imaging optical path between the telescope and the main camera. The optical coupler is used to guide a portion of the light in the main imaging optical path into the guiding optical path. The optical coupler has a first connection structure, which is used to be detachably connected to the guiding camera. When the optical coupler is connected to the guiding camera, the optical coupler and the guiding camera can be synchronously driven by the focusing device to move along the axis of the focusing device, thereby changing the radial position of the optical coupler in the main imaging optical path.
2. The off-axis star guide according to claim 1, characterized in that: The connecting body has a first channel extending along its own axis. When the connecting body is connected to the telescope and / or the main camera, the first channel is located on the main imaging optical path of the telescope and the main camera. The focusing device has a second channel extending along its own axis. The focusing device is used to connect to the guiding camera and to focus the guiding camera. The optical path coupler has a third channel extending along its own axis. One end of the optical path coupler is located in the second channel, and the other end is located in the first channel. The third channel is connected to the first channel and the second channel. The optical path coupler, the third channel, and the second channel together form the guiding optical path.
3. The off-axis star guide according to claim 2, characterized in that: The optical path coupler includes a mounting frame and an optical path beam splitter. The first end of the mounting frame is disposed in the first channel, the second end is disposed in the second channel, the third channel is disposed inside the mounting frame, the optical path beam splitter is disposed at the first end of the mounting frame, and the first connecting structure is located at the second end.
4. The off-axis star guide according to claim 3, characterized in that: The optical path beam-splitting element includes a beam-splitting prism or a reflector.
5. The off-axis star guide according to claim 3, characterized in that: The connecting body is a ring structure, which encloses and forms the first channel. The focusing device is arranged radially on the outside of the connecting body, and the axial direction of the focusing device is parallel to the radial direction of the connecting body. The connecting body is also provided with a fourth channel extending radially, which communicates with the first channel and the second channel. The portion of the mounting bracket near the first end extends into the first channel from the fourth channel. The radial dimension of the second end is larger than the radial dimension of the other portions. The second end also serves as a limiting structure to restrict the distance the optical coupler moves radially along the connecting body.
6. The off-axis star guide according to claim 5, characterized in that: The connecting body is also provided with a first locking screw, which is threadedly connected to the connecting body. The first locking screw is used to lock or unlock the optical coupler.
7. The off-axis star guide according to claim 1, characterized in that: The first connection structure is a threaded structure or a mortise and tenon structure.
8. The off-axis star guide according to claim 1, characterized in that: The focusing device is provided with a dial indicating the focusing stroke, and the dial is provided with stroke scale lines indicating the focusing stroke.
9. The off-axis star guide according to claim 8, characterized in that: The focusing device is a double-helix focusing device.
10. A guide assembly for an astronomical telescope, characterized in that, include: A guiding camera and an off-axis guiding device according to any one of claims 1-9, wherein a portion of the guiding camera is fitted inside the focusing device and is detachably connected to the focusing device, and the guiding camera is provided with a second connection structure, the second connection structure being detachably connected to a first connection structure located on the optical path coupler; When the first connection structure and the second connection structure are separated, and the guide camera is connected to the focuser, the guide camera can be driven by the focuser to move along the axis of the focuser independently; when the first connection structure and the second connection structure are connected, and the guide camera is connected to the focuser, the guide camera and the optical coupler can be driven by the focuser to move along the axis of the focuser simultaneously.
11. The astronomical telescope guide assembly according to claim 10, characterized in that, Also includes: The second locking screw is disposed on the outer cylinder of the focuser and is used at least to lock or unlock the guide camera. The outer cylinder is capable of telescopic movement along its own axis.
12. The astronomical telescope guide assembly according to claim 11, characterized in that: When the guiding camera is not connected to the outer tube, the guiding camera can generate relative linear motion along the axis of the focusing device and / or relative rotational motion around the axis of the focusing device.
13. The astronomical telescope guide assembly according to claim 12, characterized in that: The first connecting structure and the second connecting structure are connected by mortise and tenon joints or threaded connections.
14. The astronomical telescope guide assembly according to claim 13, characterized in that: The second connection structure is a mortise and tenon structure or a threaded structure.
15. The astronomical telescope guide assembly according to claim 12, characterized in that: The second connection structure is located at the end of the guide camera near the optical coupler.
16. An astronomical telescope, characterized in that: The astronomical telescope has an off-axis guideway as described in any one of claims 1-9 or an astronomical telescope guide assembly as described in any one of claims 10-15.