Imaging light path structure under energy coupling angle

Abstract

The invention discloses an imaging light path structure under an energy coupling angle. The imaging light path structure comprises a front-end imaging objective lens, a double-telecentric relay optics, a tail-end objective lens and a camera which are sequentially arranged in the direction of an optical axis, the front-end imaging objective lens is connected with the first group of objective lenses of the double-telecentric relay optics, and the image plane of the front-end imaging objective lens coincides with the object plane of the first group of objective lenses of the double-telecentric relay optics; the last group of objective lens of the double telecentric relay optics is connected with the tail end objective lens, and the image plane of the last group of objective lens coincides with the object plane of the latter objective lens; and the tail end objective lens is connected with the camera. According to the invention, the breakthrough of the image transmission characteristic between the front-end imaging objective lens and the double-telecentric relay objective lens is realized from the angle of energy coupling, that is, the front-end imaging objective lens has no special requirement of telecentric image space, and high-resolution imaging can be realized only by using one common imaging lens, so that the cost of constructing an optical path is reduced, and the optical path does not need to be designed on the whole; according to the invention, the modular design is realized, the device is easy to install and adjust, and the device has the advantages of high imaging resolution, large luminous flux and low cost.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic confinement fusion device research, and in particular to an imaging optical path structure under an energy coupling angle. Background Art

[0002] In the field of magnetic confinement fusion plasma, imaging monitoring of high-temperature plasma is necessary. Plasma visible light radiation imaging can observe the displacement, boundary and plasma-wall interaction (PWI) of plasma, and is an important diagnosis for maintaining the safe operation of magnetic confinement fusion devices. Due to the high magnetic field intensity, severe high-energy particle radiation and line radiation of high-temperature plasma, electronic devices such as imaging detectors (CCD or CMOS) are forced to be away from the device, otherwise the operation of the imaging detector will be seriously affected, which puts forward the hardware requirements for long optical path image transmission. Especially for the current monitoring needs of burning plasma, the total length of the imaging optical path is in the range of tens of meters (about 30 to 40 meters), which poses a great challenge to the assembly and debugging accuracy of the long optical path and the operational reliability.

[0003] At present, two approaches are usually used to achieve long-distance image transmission: one is based on image transmission fiber bundles, and the other is based on relay optics of multiple lens groups. The advantage of the former is that the fiber bundle can transmit images in a soft and bent state, but the imaging resolution will be limited by the core diameter of the single fiber bundle; the advantage of the latter is that the imaging resolution can be very high, but the existing technical solutions are often complicated and costly: most of them require the use of optical design software for integrated optical path design, such as endoscope and periscope structures, and have strict requirements on the installation and positioning process of the lenses. In particular, for the 30 to 40 meter long optical path designed in an integrated manner using optical design software, its installation and adjustment will be very difficult, so it is difficult to achieve good imaging resolution. Summary of the invention

[0004] The purpose of the present invention is to provide an imaging optical path structure under an energy coupling angle in view of the problems that the existing optical imaging technology solutions based on multiple lenses are often complicated and costly, and the installation and positioning processes of the lenses are strictly required. Only the front-end imaging lens and the relay optical path are designed separately in a modular manner, and then the front-end lens and the relay optical path are assembled to achieve high-quality imaging, without the need to use optical design software such as ZEMAX to design a long optical path as a whole.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention provides an imaging optical path structure under an energy coupling angle, comprising a front-end imaging objective lens, a double telecentric relay optics, a tail-end objective lens and a camera which are sequentially arranged along an optical axis direction; the front-end imaging objective lens is connected to a first group of objective lenses of the double telecentric relay optics, and an image plane of the former coincides with an object plane of the latter; the last group of objective lenses of the double telecentric relay optics is connected to the tail-end objective lens, and an image plane of the former coincides with an object plane of the latter; the tail-end objective lens is connected to the camera.

[0007] As a preferred embodiment of the present invention, the dual telecentric relay optics includes a plurality of dual telecentric relay objective lens groups, wherein the dual telecentric relay objective lens group includes two dual telecentric objective lenses symmetrically placed head to head, and the object planes of the two dual telecentric objective lenses coincide with each other; the image planes of the two dual telecentric objective lenses in adjacent dual telecentric relay objective lens groups coincide with each other.

[0008] As a preferred solution of the present invention, the two bi-telecentric objective lenses in the same bi-telecentric relay objective lens group have the same magnification.

[0009] As a preferred solution of the present invention, the magnifications of the bi-telecentric objective lenses in different bi-telecentric relay objective lens groups are the same or different.

[0010] As a preferred embodiment of the present invention, the magnification of the bi-telecentric objective lens is 1×, 0.5×, 0.33×, 0.25× and 0.18×.

[0011] As a preferred solution of the present invention, the front-end imaging objective lens is a fixed-focus lens or a zoom lens of different types.

[0012] As a preferred embodiment of the present invention, the fixed-focus lens is a structural type selected from the group consisting of a telephoto objective lens, a reverse telephoto objective lens, a three-piece objective lens, a Ruscha objective lens, a Dago objective lens, a double Gauss objective lens and a Tobcon objective lens.

[0013] As a preferred embodiment of the present invention, the front-end imaging objective lens is a double Gaussian objective lens structure.

[0014] As a preferred embodiment of the present invention, the tail end objective lens is a bi-telecentric objective lens or an object-side telecentric objective lens.

[0015] As a preferred solution of the present invention, the numerical apertures of the front-end imaging objective lens, the dual-telecentric relay optics and the rear-end objective lens match each other.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] From the perspective of energy coupling, the present invention achieves a breakthrough in the image transmission characteristics between the front-end imaging objective lens and the dual-telecentric relay objective lens, that is, the front-end imaging objective lens has no special requirements for image-side telecentricity, and high-resolution imaging can be achieved using only one ordinary imaging lens, which greatly reduces the cost of building the optical path; and the front-end imaging objective lens can be flexibly replaced according to different field of view requirements without the need to design the optical path as a whole; the optical path structure of the present invention realizes a modular design, is easier to assemble and adjust, and has the advantages of high imaging resolution, large luminous flux and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0019] Figure 1 Schematic diagram of the imaging optical path structure under the energy coupling angle in the present invention;

[0020] Figure 2 This is a diagram showing the imaging principle of the dual telecentric relay objective lens of the present invention;

[0021] Figure 3 It is a schematic diagram of the matching relationship between the image-side aperture angle of the front-end imaging objective lens and the object-side aperture angle of the double telecentric relay optics in the present invention;

[0022] Figure 4 This is a picture of the plasma inside the Chinese Circulator taken using the imaging optical path structure of the present invention.

[0023] Marks and corresponding parts names in the attached drawings:

[0024] 1- front imaging objective lens, 2- double telecentric relay optics, 2.1 and 2.2- double telecentric relay objective lens set, 2.1.1, 2.1.2, 2.2.1 and 2.2.2- double telecentric objectives, 3- rear objective lens. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0027] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0030] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0031] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces), unless otherwise clearly and specifically defined.

[0032] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0033] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0034] In the field of magnetic confinement fusion plasma, when imaging and monitoring high-temperature plasma, in order to avoid affecting the imaging detector, it is necessary to use long-distance image transmission to achieve it. Currently, two approaches are usually used: image transmission fiber bundles and relay optics based on multi-lens groups. The advantage of the former is that the fiber bundle can transmit images in a soft and bent state, but the imaging resolution will be limited by the core diameter of the single fiber bundle; the advantage of the latter is that the imaging resolution can be very high.

[0035] However, among the existing technologies based on multi-lens relay optics, most require the use of optical design software for integrated optical path design, and the lens assembly and adjustment process has strict requirements, and the scheme is complex and costly. Even if the relay optics part of some optical paths utilizes a double telecentric lens group, it is still restricted to the image-side telecentric design of the front-end lens.

[0036] Based on this, the inventors, after in-depth research, proposed an imaging optical path structure under the energy coupling angle, which uses multiple groups of double-telecentric relay objectives to transmit the imaging of the front-end objective lens. The optical path is simple and easy to adjust, and a modular design is realized; and the front-end imaging lens does not have the special requirements of image-side telecentricity in the prior art, and only requires an ordinary imaging lens to achieve high-quality imaging; at the same time, the field of view can be changed by replacing the fixed-focus objective lens at the front end, or a zoom lens can be directly installed to achieve the change of the field of view, without the need to design the optical path as a whole; this solution can not only be directly applied to the field of magnetic confinement fusion plasma, but it is also suitable for other industrial fields with harsh imaging environments as a tool for long optical path image transmission.

[0037] Please refer to Figures 1 to 4 An imaging optical path structure under an energy coupling angle provided in an embodiment of the present application comprises a front-end imaging objective lens 1, a double telecentric relay optics 2, a rear-end objective lens 3 and a camera arranged in sequence along the optical axis direction; the front-end imaging objective lens 1 is connected to the first group of objective lenses of the double telecentric relay optics 2, and the image plane of the former coincides with the object plane of the latter; the last group of objective lenses of the double telecentric relay optics 2 is connected to the rear-end objective lens 3, and the image plane of the former coincides with the object plane of the latter; the rear-end objective lens 3 is connected to the camera.

[0038] According to some embodiments of the present application, the dual-telecentric relay optics 2 includes multiple dual-telecentric relay objective lens groups, and the dual-telecentric relay objective lens group includes two dual-telecentric objective lenses symmetrically placed head to head, and the object planes of the two dual-telecentric objective lenses coincide with each other; the image planes of two dual-telecentric objective lenses in adjacent dual-telecentric relay objective lens groups coincide with each other.

[0039] It should be noted that, for the bi-telecentric objective lens described in this embodiment, the chief rays of different field points are parallel to the optical axis both on the object side and on the image side. Figure 2 The schematic diagram of the imaging of a double telecentric objective lens is shown, where the solid line is the light path of the central field point and the dotted line is the light path of the edge field point.

[0040] According to some embodiments of the present application, the two bi-telecentric objective lenses in the same bi-telecentric relay objective lens group have the same magnification. The magnifications of the bi-telecentric objective lenses in different bi-telecentric relay objective lens groups are the same or different. The magnifications of the bi-telecentric objective lenses can be 1×, 0.5×, 0.33×, 0.25×, 0.18×, etc.

[0041] According to some embodiments of the present application, the front-end imaging objective lens 1 may be a fixed-focus lens or a zoom lens of different types. Among them, the fixed-focus lens may be a structural type selected from a telephoto objective lens, a reverse telephoto objective lens, a three-piece objective lens, a Ruscha objective lens, a Dago objective lens, a double Gauss objective lens, and a Tobgan objective lens. Since the front-end imaging objective lens 1 does not have special requirements for image-side telecentricity, high-resolution imaging can be achieved using only one ordinary imaging lens, which greatly reduces the cost of optical path construction; and the fixed-focus lens can be flexibly replaced according to different field of view requirements, or a zoom lens can be directly installed to achieve changes in the field of view, without the need to use optical design software to design the optical path as a whole.

[0042] According to some embodiments of the present application, the end objective lens 3 may be a bi-telecentric objective lens or an object-side telecentric objective lens. Since the front end of the end objective lens 3 is a bi-telecentric relay optics 2, and the object-side principal ray and the image-side principal ray of the bi-telecentric optics are both parallel to the optical axis, the end objective lens 3 is required to be a bi-telecentric objective lens or an object-side telecentric objective lens.

[0043] According to some embodiments of the present application, the numerical apertures of the front imaging objective lens 1, the dual telecentric relay optics 2 and the rear objective lens 3 are matched with each other to facilitate the collection of light energy from the front objective lens by the rear objective lens.

[0044] Specifically, the following combination Figure 1 The imaging optical path structure in this embodiment is described in detail. Figure 1 In the specific implementation example, the dual telecentric relay optics 2 includes two dual telecentric relay objective lens groups, namely dual telecentric relay objective lens groups 2.1 and 2.2. The dual telecentric relay objective lens groups 2.1 and 2.2 are also arranged in sequence along the optical axis direction.

[0045] The double telecentric relay objective lens set 2.1 includes a pair of identical double telecentric objectives with a magnification of 1×, namely double telecentric objectives 2.1.1 and 2.1.2; the two double telecentric objectives 2.1.1 and 2.1.2 are symmetrically placed "head to head", and the object planes of the two coincide at the position of the intermediate image plane II.

[0046] The double telecentric relay objective lens set 2.2 also includes a pair of identical double telecentric objectives with a magnification of 0.33×, namely double telecentric objectives 2.2.1 and 2.2.2; the two double telecentric objectives 2.2.1 and 2.2.2 are symmetrically placed "head to head", and the object planes of the two coincide at the position of the intermediate image plane IV.

[0047] The image planes of the double telecentric objective 2.1.2 and the double telecentric objective 2.2.1 in the two double telecentric relay objective lens groups 2.1 and 2.2 coincide with each other at the position of the intermediate image plane III.

[0048] In fact, different dual telecentric relay objective lens groups can also use objective lens units with magnifications of 0.5×, 0.25×, and 0.18×, and are placed symmetrically "head to head". By increasing the number of dual telecentric relay objective lens groups along the optical axis, the length of the entire relay optical path can be extended.

[0049] The front imaging objective lens 1 is connected to the first set of double telecentric objective lenses 2.1.1 of the double telecentric relay optics 2, and the image plane of the former coincides with the object plane of the latter at the position of the intermediate image plane I. The front imaging objective lens 1 is an ordinary surveillance lens and does not require image telecentricity. Figure 1 In the figure, the front imaging objective lens 1 is a double Gaussian objective lens structure, which is more beneficial to the light throughput of the entire imaging system. In fact, the front imaging objective lens 1 can be a fixed focus lens of different types or a zoom lens. The so-called different types of fixed focus lenses specifically include telephoto objective lenses, reverse telephoto objective lenses, three-piece objective lenses, Ruscha objective lenses, Dago objective lenses, double Gaussian objective lenses, Tobgan objective lenses, etc.

[0050] The main light from the front imaging objective lens 1 is not telecentric in the image direction, but has a certain angle with the optical axis, such as Figure 3 The angle κ between the off-axis principal ray and the optical axis on the left side of the intermediate image plane I is shown as follows. The image side aperture angle of the front imaging objective lens 1 at a certain field of view is α, as shown in Figure 3 The principal ray of the double telecentric relay objective is parallel to the optical axis in the object and image sides, and the object side aperture angle is γ, as shown in Figure 3 As shown by the solid line in . Therefore, only the portion of the light energy within the aperture angle α is collected by the double telecentric relay objective lens, as shown in the shaded area; the larger the object side aperture angle γ of the double telecentric relay optics, the more conducive it is to the collection of light energy from the front imaging objective lens 1. In addition, the more uniform the illumination of the front imaging objective lens 1 at the intermediate image plane, that is, the larger the angle κ between the off-axis principal ray and the optical axis, the more conducive it is to the collection of light energy.

[0051] The last group of double telecentric objective lens 2.2.2 of double telecentric relay optics 2 is connected to the tail objective lens 3, and the image plane of the former coincides with the object plane of the latter at the position of the intermediate image plane V. The tail objective lens can be a double telecentric objective lens or an object-side telecentric objective lens. Finally, the tail objective lens 3 is connected to the camera. The numerical apertures (or f-numbers) of each sub-optical structure (front-end imaging objective lens 1, double telecentric relay optics 2 and tail objective lens 3) of the entire optical path match each other. For example, if the image-side numerical aperture of the last group of double telecentric objective lens 2.2.2 of double telecentric relay optics 2 is 0.2, the object-side numerical aperture of the tail objective lens 3 should be greater than or equal to 0.2.

[0052] Figure 4 This is a plasma effect diagram inside the Chinese Circulator taken using the imaging optical path structure in this embodiment.

[0053] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An imaging optical path structure under an energy coupling angle, characterized in that: The invention comprises a front-end imaging objective lens, a double telecentric relay optics, a rear-end objective lens and a camera which are sequentially arranged along the optical axis direction; the front-end imaging objective lens is connected to the first group of objective lenses of the double telecentric relay optics, and the image plane of the former coincides with the object plane of the latter; the last group of objective lenses of the double telecentric relay optics is connected to the rear-end objective lens, and the image plane of the former coincides with the object plane of the latter; the rear-end objective lens is connected to the camera.

2. The imaging optical path structure under the energy coupling angle according to claim 1, characterized in that: The dual telecentric relay optics includes a plurality of dual telecentric relay objective lens groups, wherein the dual telecentric relay objective lens group includes two dual telecentric objective lenses symmetrically placed head to head, and the object planes of the two dual telecentric objective lenses overlap; The image planes of two bi-telecentric objectives in an adjacent bi-telecentric relay objective lens group coincide with each other.

3. The imaging optical path structure under the energy coupling angle according to claim 2, characterized in that: The two bi-telecentric objectives in the same bi-telecentric relay objective set have the same magnification.

4. The imaging optical path structure under the energy coupling angle according to claim 2, characterized in that: The magnifications of the bi-telecentric objectives in different bi-telecentric relay objective groups are the same or different.

5. The imaging optical path structure under the energy coupling angle according to claim 2, characterized in that: The bi-telecentric objective has magnifications of 1×, 0.5×, 0.33×, 0.25× and 0.18×.

6. The imaging optical path structure under the energy coupling angle according to claim 1, characterized in that: The front-end imaging objective lens is a fixed-focus lens or a zoom lens of different types.

7. The imaging optical path structure under the energy coupling angle according to claim 6, characterized in that: The fixed-focus lens is a structural type selected from the group consisting of a telephoto objective lens, a reverse telephoto objective lens, a three-piece objective lens, a Ruscha objective lens, a Dago objective lens, a double Gauss objective lens and a Tobgan objective lens.

8. The imaging optical path structure under the energy coupling angle according to claim 7, characterized in that: The front-end imaging objective lens is a double Gaussian objective lens structure.

9. The imaging optical path structure under the energy coupling angle according to claim 1, characterized in that: The tail end objective lens is a bi-telecentric objective lens or an object-side telecentric objective lens.

10. The imaging optical path structure under the energy coupling angle according to claim 1, characterized in that: The numerical apertures of the front imaging objective lens, the dual telecentric relay optics and the rear objective lens match each other.

Images