Compact clamping type telescopic double-view-field optical system

Abstract

The invention provides a compact clamping type telescopic double-view-field optical system, and belongs to the technical field of optical detection.The compact clamping type telescopic double-view-field optical system comprises a narrow-view-field telescopic system and a wide-view-field telescopic system, the working face of a narrow-view-field primary mirror and the working face of a wide-view-field primary mirror face the same side, and the working face of the narrow-view-field primary mirror and the working face of the wide-view-field primary mirror are arranged in a staggered mode; telescopic exit pupil positions of the narrow-view-field telescopic system and the wide-view-field telescopic system coincide, the telescopic exit pupil calibers are consistent, when a narrow view field works, the narrow-view-field reflex reflector directly faces a center hole of the narrow-view-field primary mirror, the wide-view-field telescopic eyepiece group is located between the narrow-view-field reflex reflector and the wide-view-field reflex reflector, and the wide-view-field telescopic eyepiece group is located between the narrow-view-field reflex reflector and the wide-view-field reflex reflector. Emergent light of the wide-view-field telescopic eyepiece group is all positioned on the back surface of the narrow-view-field reflex reflector; when the wide view field works, the narrow view field reflex reflector is located outside the emergent light range of the wide view field telescopic eyepiece group. The optical system is compact in structure, and the problem that the obscuration ratio of a wide view field is large after zooming of a card type system is solved.

Description

Technical Field

[0001] The present application relates to the field of optical detection, and in particular to a compact card-type telescopic dual-field optical system. Background Art

[0002] In order to meet the needs of long-distance target reconnaissance and detection, the optical system needs to be designed with a long focal length and a large aperture. However, due to the limitation of lens materials, large-aperture optical systems generally adopt a cassette structure, which is divided into a total reflection type and a catadioptric type. The catadioptric structure is relatively more compact and suitable for the limited space volume of aviation aircraft.

[0003] For aviation airborne reconnaissance systems, in order to achieve the requirement of rapid imaging of the array, a fast mirror needs to be placed in the parallel optical path, which requires the optical system to have a telephoto optical path and emit parallel light. On the other hand, in order to achieve a wider range of scanning, the system also has a wide field of view requirement. If the magnification is changed in the card-type system, it will greatly increase the difficulty of design and make it difficult to correct the aberration; in addition, because the size of the secondary mirror is limited by the narrow field of view, the wide field of view obstruction ratio will be very large, which will seriously affect the wide field of view imaging effect. Summary of the invention

[0004] In view of this, the present application provides a compact card-type telephoto dual-field optical system, which solves the problem of large obstruction ratio of wide field of view in the prior art.

[0005] The present application provides a compact card-type telescopic dual-field optical system adopts the following technical solution:

[0006] A compact cassette telescope dual-field optical system, comprising a narrow-field telescope system and a wide-field telescope system, wherein the narrow-field telescope system comprises a narrow-field primary mirror, a narrow-field secondary mirror, a narrow-field telescope eyepiece group and a narrow-field folding reflector, and the wide-field telescope system comprises a wide-field primary mirror, a wide-field secondary mirror, a wide-field telescope eyepiece group and a wide-field folding reflector;

[0007] The working surface of the narrow field of view primary mirror and the working surface of the wide field of view primary mirror face the same side, and the working surface of the narrow field of view primary mirror and the working surface of the wide field of view primary mirror are arranged alternately;

[0008] The narrow field of view telescope system comprises a narrow field of view primary mirror, a narrow field of view secondary mirror, a narrow field of view telescope eyepiece group and a narrow field of view folding reflector in sequence along the optical path, wherein the narrow field of view telescope eyepiece group is located in the central opening of the narrow field of view primary mirror, the narrow field of view folding reflector is located on the back of the narrow field of view primary mirror, and the narrow field of view folding reflector is directly opposite to the central opening of the narrow field of view primary mirror;

[0009] The wide-field telescope system comprises a wide-field primary mirror, a wide-field secondary mirror, a wide-field folding reflector and a wide-field telescope eyepiece group in order along the optical path, wherein the wide-field folding reflector and the wide-field telescope eyepiece group are both located on the back of the wide-field primary mirror, and the wide-field folding reflector faces the central hole of the wide-field primary mirror;

[0010] Among them, the field of view angle of the narrow field of view telescope system is smaller than the field of view angle of the wide field of view telescope system, the telescope exit pupil positions of the narrow field of view telescope system and the wide field of view telescope system coincide, and the telescope exit pupil diameters are consistent, and the switching between wide field of view and narrow field of view operation is achieved by cutting the narrow field of view folding reflector into or out of the optical path.

[0011] Optionally, the working surfaces of the narrow-field-of-view primary mirror and the wide-field-of-view primary mirror are parabolic surfaces.

[0012] Optionally, the working surfaces of the narrow field of view secondary mirror and the wide field of view secondary mirror are convex hyperbolic surfaces or convex high-order aspherical surfaces.

[0013] Optionally, the optical axis direction of the wide-field telescope eyepiece set is perpendicular to the optical axis direction of the narrow-field telescope eyepiece set.

[0014] When the narrow field of view is working, the wide field of view telescope eyepiece group is located between the narrow field of view folding reflector and the wide field of view folding reflector, and all the outgoing light rays of the wide field of view telescope eyepiece group are located on the back of the narrow field of view folding reflector;

[0015] When the wide field of view is working, the narrow field of view folding reflector is located outside the range of the outgoing light of the wide field of view telescope eyepiece group.

[0016] Optionally, the narrow-field telescope eyepiece group includes four lenses, which are a negative lens, a positive lens, a negative lens and a positive lens in sequence.

[0017] Optionally, the wide-field telescope eyepiece group includes four lenses, which are a negative lens, a positive lens, a positive lens and a negative lens in sequence. The wide-field telescope eyepiece group is used to fold the rear end optical path to the telescope exit pupil position.

[0018] Optionally, the narrow field of view folding reflector and the wide field of view folding reflector are both plane reflectors, and the narrow field of view folding reflector and the wide field of view folding reflector are parallel to each other.

[0019] Optionally, the magnification ratio between the wide field of view and the narrow field of view is 1.5-3 times.

[0020] In summary, this application includes the following beneficial technical effects:

[0021] The present application adopts two cassette telescope structures, and realizes the optical magnification of the cassette system by placing a narrow field of view telescope eyepiece group at the opening position of the main mirror and a wide field of view telescope eyepiece group on the back of the main mirror, and cutting in and out the narrow field of view folding reflector. The system structure is compact and avoids the problem of large wide field of view obstruction ratio after the cassette system is changed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a schematic diagram of the structure of the compact card-type telescope dual-field optical system of this application;

[0024] Figure 2 This is a schematic diagram of the narrow field of view optical path structure in an embodiment of the present application;

[0025] Figure 3 Schematic diagram of the wide field of view optical path structure in the embodiment of the present application.

[0026] Explanation of the accompanying reference numerals: 1. target light; 2. narrow field of view telescope system; 21. narrow field of view primary mirror; 22. narrow field of view secondary mirror; 23. narrow field of view telescope eyepiece group; 24. narrow field of view folding reflector; 3. wide field of view telescope system; 31. wide field of view primary mirror; 32. wide field of view secondary mirror; 33. wide field of view folding reflector; 34. wide field of view telescope eyepiece group; 4. telescope exit pupil position. DETAILED DESCRIPTION

[0027] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0028] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0029] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0030] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show the components related to the present application rather than being drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0031] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0032] An embodiment of the present application provides a compact card-type telescopic dual-field optical system.

[0033] like Figure 1 As shown, a compact cassette telescope dual-field optical system includes a narrow-field telescope system 2 and a wide-field telescope system 3. The narrow-field telescope system 2 includes a narrow-field primary mirror 21, a narrow-field secondary mirror 22, a narrow-field telescope eyepiece group 23, and a narrow-field folding reflector 24. The wide-field telescope system 3 includes a wide-field primary mirror 31, a wide-field secondary mirror 32, a wide-field telescope eyepiece group 34, and a wide-field folding reflector 33. The working surface of the narrow-field primary mirror 21 and the working surface of the wide-field primary mirror 31 face the same side, and the working surface of the narrow primary mirror and the working surface of the wide-field primary mirror 31 are staggered.

[0034] The narrow field of view telescope system 2 comprises a narrow field of view primary mirror 21, a narrow field of view secondary mirror 22, a narrow field of view telescope eyepiece group 23 and a narrow field of view folding reflector 24 in the direction of traveling along the optical path. The narrow field of view telescope eyepiece group 23 is located in the central opening of the narrow field of view primary mirror 21, and the narrow field of view folding reflector 24 is located on the back of the narrow field of view primary mirror 21, and the narrow field of view folding reflector 24 is directly opposite to the central hole of the narrow field of view primary mirror 21.

[0035] The wide field of view telescope system 3 comprises a wide field of view primary mirror 31, a wide field of view secondary mirror 32, a wide field of view folding reflector 33 and a wide field of view telescope eyepiece group 34 in the direction of travel of the optical path. The wide field of view folding reflector 33 and the wide field of view telescope eyepiece group 34 are both located on the back of the wide field of view primary mirror 31, and the wide field of view folding reflector 33 is directly opposite to the center hole of the wide field of view primary mirror 31.

[0036] Among them, the field of view angle of the narrow field of view telescope system 2 is smaller than the field of view angle of the wide field of view telescope system 3, the telescope exit pupil position 4 of the narrow field of view telescope system 2 and the wide field of view telescope system 3 coincide, and the telescope exit pupil diameter is consistent, so that the rear end can be connected to the same imaging component; and the switching between wide field of view and narrow field of view operation is achieved by cutting the narrow field of view folding reflector 24 into or out of the optical path.

[0037] The present application adopts two cassette telescope structures, and realizes the optical magnification of the cassette system by placing the narrow field of view telescope eyepiece group 23 at the opening position of the main mirror and the wide field of view telescope eyepiece group 34 on the back of the main mirror, and cutting in and out the narrow field of view folding reflector 24. The system structure is compact and avoids the problem of large wide field of view obstruction ratio after the cassette system is changed.

[0038] The working surfaces of the narrow-field primary mirror 21 and the wide-field primary mirror 31 are parabolic surfaces.

[0039] The working surfaces of the narrow field of view secondary mirror 22 and the wide field of view secondary mirror 32 are convex hyperbolic surfaces or convex high-order aspherical surfaces.

[0040] like Figure 2 and Figure 3 As shown, the optical axis direction of the wide-field telescope eyepiece group 34 is perpendicular to the optical axis direction of the narrow-field telescope eyepiece group 23. When the narrow field of view is working, the wide-field telescope eyepiece group 34 is located between the narrow-field folding reflector 24 and the wide-field folding reflector 33, and all the outgoing light rays of the wide-field telescope eyepiece group 34 are located on the back of the narrow-field folding reflector 24; when the wide field of view is working, the narrow-field folding reflector 24 is located outside the outgoing light range of the wide-field telescope eyepiece group 34. In one embodiment, the position change of the narrow-field folding reflector 24 can be achieved by a sliding mechanism, which drives the narrow-field folding reflector 24 to move within the outgoing light range of the wide-field telescope eyepiece group 34 and outside the outgoing light range of the wide-field telescope eyepiece group 34.

[0041] The narrow-field telescope eyepiece group 23 includes four lenses, which are negative lens, positive lens, negative lens and positive lens in the direction of light entry. The materials are zinc sulfide, zinc selenide, zinc sulfide and zinc selenide in order. In order to compress the volume and prevent the wide-field telescope light path from being blocked, it is located at the opening position of the main mirror.

[0042] The wide-field telescope eyepiece assembly 34 includes four lenses, which are a negative lens, a positive lens, a positive lens and a negative lens in the direction of light entry. The wide-field telescope eyepiece assembly 34 is used to fold the rear optical path to the telescope exit pupil position 4. The materials are zinc selenide, zinc selenide, single crystal germanium and single crystal silicon in sequence.

[0043] The narrow field of view folding reflector 24 and the wide field of view folding reflector 33 are both plane reflectors, and the narrow field of view folding reflector 24 and the wide field of view folding reflector 33 are parallel to each other. The narrow field of view folding reflector 24 and the wide field of view folding reflector 33 are made of fused quartz.

[0044] The narrow field of view primary mirror 21 and the narrow field of view secondary mirror 22 have real primary image points and form a perfect image on the axis, which is convenient for installation and adjustment.

[0045] The wide-field primary mirror 31 and the wide-field secondary mirror 32 have real primary image points and form perfect images on the axis, which is convenient for installation and adjustment.

[0046] The zoom ratio of the wide field of view and the narrow field of view is 1.5-3 times. In the embodiment of the present application, the compression ratio of the narrow field of view telescope is 12 times, and the compression ratio of the wide field of view telescope is 6 times, that is, the zoom ratio of the wide and narrow field of view is 2 times.

[0047] The working band of the optical system of the present application can be visible light, near infrared, short-wave infrared, medium-wave infrared, long-wave infrared, or any two or more combined bands.

[0048] For a more detailed explanation, the specific parameters of the optical system of the embodiment of the present application are given below: Table 1 shows the design index parameters of a compact card-type telescope dual-field-of-view optical system, Table 2 shows the narrow field-of-view embodiment parameters of a compact card-type telescope dual-field-of-view optical system, and Table 3 shows the wide field-of-view embodiment parameters of a compact card-type telescope dual-field-of-view optical system.

[0049] Table 1 Design parameters of a compact card-type telescope dual-field optical system

[0050]

[0051] Table 2 Parameters of a compact card-type telescopic dual-field optical system with narrow field of view

[0052]

[0053] Table 3 Parameters of a compact card-type telescopic dual-field optical system with wide field of view

[0054]

[0055] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A compact card-type telephoto dual-field optical system, characterized in that: The invention comprises a narrow-field telescope system (2) and a wide-field telescope system (3), wherein the narrow-field telescope system (2) comprises a narrow-field primary mirror (21), a narrow-field secondary mirror (22), a narrow-field telescope eyepiece group (23) and a narrow-field folding reflector (24), and the wide-field telescope system (3) comprises a wide-field primary mirror (31), a wide-field secondary mirror (32), a wide-field telescope eyepiece group (34) and a wide-field folding reflector (33); The working surface of the narrow-viewing primary mirror (21) and the working surface of the wide-viewing primary mirror (31) face the same side, and the working surface of the narrow-viewing primary mirror and the working surface of the wide-viewing primary mirror (31) are arranged alternately; The narrow field of view telescope system (2) comprises a narrow field of view primary mirror (21), a narrow field of view secondary mirror (22), a narrow field of view telescope eyepiece group (23) and a narrow field of view folding reflector (24) in sequence along the direction of travel of the optical path; the narrow field of view telescope eyepiece group (23) is located in a central opening of the narrow field of view primary mirror (21); the narrow field of view folding reflector (24) is located on the back of the narrow field of view primary mirror (21), and the narrow field of view folding reflector (24) is directly opposite to the central opening of the narrow field of view primary mirror (21); The wide-field telescopic system (3) comprises, in order along the direction of travel of the optical path, a wide-field primary mirror (31), a wide-field secondary mirror (32), a wide-field folding reflector (33) and a wide-field telescopic eyepiece group (34); the wide-field folding reflector (33) and the wide-field telescopic eyepiece group (34) are both located on the back of the wide-field primary mirror (31), and the wide-field folding reflector (33) faces the central hole of the wide-field primary mirror (31); The field of view angle of the narrow field of view telescope system (2) is smaller than the field of view angle of the wide field of view telescope system (3), the telescope exit pupil positions (4) of the narrow field of view telescope system (2) and the wide field of view telescope system (3) overlap, the telescope exit pupil diameters are consistent, and the switching between wide field of view operation and narrow field of view operation is achieved by cutting the narrow field of view folding reflector (24) into or out of the optical path.

2. The compact card-type telephoto dual-field optical system according to claim 1, characterized in that: The working surfaces of the narrow-field-of-view primary mirror (21) and the wide-field-of-view primary mirror (31) are parabolic surfaces.

3. The compact card-type telephoto dual-field optical system according to claim 1, characterized in that: The working surfaces of the narrow field of view secondary mirror (22) and the wide field of view secondary mirror (32) are convex hyperbolic surfaces or convex high-order aspherical surfaces.

4. The compact card-type telephoto dual-field optical system according to claim 1, characterized in that: The optical axis direction of the wide-field telescopic eyepiece set (34) is perpendicular to the optical axis direction of the narrow-field telescopic eyepiece set (23). When the narrow field of view is in operation, the wide field of view telescope eyepiece set (34) is located between the narrow field of view folding reflector (24) and the wide field of view folding reflector (33), and all the outgoing light rays of the wide field of view telescope eyepiece set (34) are located on the back side of the narrow field of view folding reflector (24); When the wide field of view is in operation, the narrow field of view folding reflector (24) is located outside the range of the outgoing light beam of the wide field of view telescope eyepiece group (34).

5. The compact card-type telephoto dual-field optical system according to claim 1, characterized in that: The narrow-field telescopic eyepiece group (23) comprises four lenses, which are a negative lens, a positive lens, a negative lens and a positive lens in sequence.

6. The compact card-type telephoto dual-field optical system according to claim 1, characterized in that: The wide-view telescope eyepiece set (34) comprises four lenses, which are a negative lens, a positive lens, a positive lens and a negative lens in sequence. The wide-view telescope eyepiece set (34) is used to fold the rear optical path to the telescope exit pupil position (4).

7. The compact card-type telephoto dual-field optical system according to claim 1, characterized in that: The narrow field of view folding reflector (24) and the wide field of view folding reflector (33) are both plane reflectors, and the narrow field of view folding reflector (24) and the wide field of view folding reflector (33) are parallel to each other.

8. The compact card-type telephoto dual-field optical system according to claim 1, characterized in that: The wide field of view and narrow field of view have a magnification ratio of 1.5 to 3 times.

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