High-precision establishment and transmission method of optical axis of telescope primary mirror

Abstract

The present application relates to optical system adjustment technology field, especially a kind of high-precision establishment and transmission method of telescope primary mirror optical axis, comprising: using first theodolite is aimed at interferometer by primary mirror center hole, then the angle of first theodolite represents the angle of primary mirror optical axis;Cuboid prism is installed on the side wall of primary mirror assembly structure member, and aiming is carried out using second theodolite, the angle of second theodolite represents the angle of cuboid prism in current state;Rotating first theodolite and second theodolite are mutually aimed at, establish the relationship of both, determine the angle deviation of cuboid prism current angle and primary mirror optical axis, and according to angle deviation value, the angle of cuboid prism is adjusted accordingly, until cuboid prism optical axis and primary mirror optical axis are coaxial, complete the replacement of cuboid prism optical axis to primary mirror optical axis, realize the establishment and transmission of primary mirror optical axis.The process of using this method to establish primary mirror optical axis is simple, easy to operate, and the established optical axis is high in precision and good in stability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of optical system adjustment, and particularly relates to a high-precision establishment and transmission method of a main mirror optical axis of a telescope. BACKGROUND

[0002] In an optical system, optical axis precision is a very important parameter, and the optical axis precision will directly affect the imaging quality and stability of the optical system. The higher the optical axis precision, the better the imaging quality and the stronger the imaging stability of the optical system. Conversely, the lower the optical axis precision, the worse the imaging quality and the weaker the imaging stability of the optical system. Therefore, in the design and manufacture of an optical system, optical axis precision is a very important consideration.

[0003] In an optical telescope, the main mirror is usually used as a reference of the entire telescope system, and the secondary mirror, the tertiary mirror, the subsequent optical path and the terminal are arranged on the basis of the main mirror as a reference. The optical axis of the main mirror becomes the installation reference of the subsequent optical elements and the terminal, and affects the installation precision of the subsequent optical elements and the terminal, and determines the optical imaging quality and stability of the entire telescope system. In other words, the optical axis of the main mirror is the optical axis of the telescope system, and therefore the high-precision establishment and transmission of the optical axis of the main mirror is very important.

[0004] At present, most telescope systems do not mark the optical axis of the main mirror during adjustment, and the optical axis of the main mirror cannot be accurately found, resulting in deviations in the optical system pointing, off-axis field image quality and design. Although a few telescope systems involve the establishment of the optical axis of the main mirror during adjustment, the establishment method is complicated, resulting in a large amount of work and calculation, and the precision is insufficient. SUMMARY

[0005] Therefore, the present application aims to provide a high-precision establishment and transmission method of the optical axis of the main mirror of a telescope, which is simple and easy to operate.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0007] A high-precision establishment and transmission method of the optical axis of the main mirror of a telescope, comprising the following steps:

[0008] S1. Building a detection light path for detecting the surface shape of the main mirror of the telescope installed on the main mirror support structure; wherein the detection light path comprises an interferometer and a compensator installed with a standard plane lens, and when the detection light path is aligned with the main mirror of the telescope, the main mirror of the telescope, the compensator and the interferometer are coaxial;

[0009] S2. Using the first electronic autocollimator, aiming the standard plane mirror through the central hole of the main mirror of the telescope, recording the azimuth angle a1 and the elevation angle b1 of the first electronic autocollimator, and using the self-function of the first electronic autocollimator to clear the azimuth angle a1;

[0010] S3. Installing the cubic prism on the side wall of the main mirror support structure through the prism fixing seat, aiming the cubic prism using the second electronic autocollimator, and recording the azimuth angle a2 and the elevation angle b2 of the second electronic autocollimator;

[0011] S4. Rotating the first electronic autocollimator and the second electronic autocollimator to mutually aim, at this time recording the azimuth angle a1' of the first electronic autocollimator, and using the self-function of the second electronic autocollimator to clear the azimuth angle a2;

[0012] S5. Rotating the second electronic autocollimator to re-aim the cubic prism, and recording the azimuth angle a2' and the elevation angle b2' of the second electronic autocollimator again;

[0013] S6. Adjusting the azimuth angle and the elevation angle of the cubic prism to make the optical axis of the cubic prism completely coaxial with the optical axis of the main mirror of the telescope; wherein the condition that the optical axis of the cubic prism is coaxial with the optical axis of the main mirror of the telescope is as follows:

[0014] a2'=180°-a1';

[0015] b2'=b1.

[0016] Further, when the optical axis of the cubic prism is not completely coaxial with the optical axis of the main mirror of the telescope, the deviations of the azimuth angle a2' and the elevation angle b2' of the cubic prism in the current state from the ideal values are calculated, and the azimuth angle and the elevation angle of the cubic prism are adjusted according to the deviation values until a2=180°-a1', b2=b1.

[0017] Further, the cubic prism is bonded on the prism fixing seat, threaded holes are processed on the side wall of the main mirror support structure, the prism fixing seat is fixed on the side wall of the main mirror support structure through screws, and a through hole is processed on the prism fixing seat, the diameter of the through hole being greater than the diameter of the screw.

[0018] Further, the adjustment of the azimuth angle of the cubic prism is realized through the adjustment of the screw in the through hole.

[0019] Further, the adjustment of the elevation angle of the cubic prism is realized by grinding the bottom surface of the prism fixing seat.

[0020] Compared with the prior art, the present application can achieve the following beneficial effects:

[0021] 1. The method for establishing the optical axis of the primary mirror is simple, easy to operate, and has high precision and good stability.

[0022] 2. The method can establish and transfer the optical axis from the three-dimensional space level, that is, the relative relationship between any line and surface features in space and the optical axis can be determined, thereby accurately guiding the telescope system adjustment and ensuring the system performance. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which form a part of this application, are intended to provide further understanding of the application and are incorporated herein for a description of the application. The description of the application and its illustrations are intended to explain the application without imposing undue limitation on the application. In the drawings:

[0024] Figure 1 FIG. 1 is a schematic diagram of the principle of the high-precision establishment and transfer method of the optical axis of the primary mirror of a telescope according to an embodiment of the application.

[0025] Legend of the drawings: interferometer 1, standard plane lens 2, compensator 3, primary mirror 4, primary mirror support structure 5, cubic prism 6, prism fixing seat 7, first electronic autocollimator theodolite 8, second electronic autocollimator theodolite 9, primary mirror optical axis 10, cubic prism optical axis 11. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the application clearer and more understandable, the application will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the application, and do not constitute a limitation on the application.

[0027] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0028] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more features. In the description of the application, unless otherwise stated, the meaning of "multiple" is two or more.

[0029] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0030] The present application will be described in detail below with reference to Figure 1 and in conjunction with the embodiments.

[0031] As Figure 1 shown, the present application provides a high-precision establishment and transmission method for the optical axis of a telescope primary mirror, comprising the following steps:

[0032] S1. Building a detection light path for detecting the surface shape of a telescope primary mirror 4 (hereinafter referred to as primary mirror 4) mounted on a primary mirror support structure 5.

[0033] After the primary mirror 5 is processed, the detection light path is built to detect the surface shape of the primary mirror 4, which includes an interferometer 1 and a compensator 3. A standard plane lens 2 is mounted on the interferometer 1 for cooperation detection. The interferometer 1 emits a plane wave to realize the surface shape detection of the primary mirror 5. The compensator 3 includes two or more pieces of optical glass, which are pre-assembled in high precision and position according to the design requirements.

[0034] When the detection light path is aligned with the primary mirror 4, the primary mirror 4, the compensator 3 and the interferometer 1 must be completely coaxial.

[0035] S2. Using the first electronic autocollimator theodolite 8 to aim the standard plane lens 2 through the center hole of the primary mirror 4, recording the azimuth angle α1 and the elevation angle β1 of the first electronic autocollimator theodolite, and using the self-function of the first electronic autocollimator theodolite to clear the azimuth angle α1.

[0036] Since the azimuth angle of the first electronic autocollimator theodolite 8 is a relative value, and the elevation angle is an absolute value with the earth as a reference, when the first electronic autocollimator theodolite 8 aims at the standard plane lens 2, the azimuth angle α1 is cleared by using the self-function of the first electronic autocollimator theodolite 8, and the azimuth α1 and the elevation angle β1 of the first electronic autocollimator theodolite 8 at this time are recorded, wherein the azimuth angle α1 = 0°, and the elevation angle β1 is the elevation angle of the primary mirror optical axis 10.

[0037] S3. Install the cube prism 6 on the side wall of the primary mirror support structure 5 through the prism fixing seat 7, aim the cube prism 6 by the second electronic autocollimator theodolite 9, and record the azimuth angle α2 and the elevation angle β2 of the second electronic autocollimator theodolite 9.

[0038] A threaded hole is processed on the side wall of the primary mirror support structure 5, a through hole is processed on the prism fixing seat 7, the cube prism 6 is glued on the prism fixing seat 7 by epoxy resin, the prism fixing seat 7 and the cube prism 6 are fixed on the side wall of the primary mirror support structure 5 as a whole through a screw, the diameter of the through hole on the prism fixing seat 7 is larger than the diameter of the screw, so that there is a gap between the screw and the through hole, which facilitates the adjustment of the azimuth angle of the cube prism 6, and the elevation angle of the cube prism 6 is realized by grinding the bottom surface of the prism fixing seat 7.

[0039] The azimuth angle α2 and the elevation angle β2 represent the angles of the installed cube prism 6 in the current state.

[0040] S4. Rotate the first electronic autocollimator theodolite 8 and the second electronic autocollimator theodolite 9 to mutually aim, at this time, record the azimuth angle α1` of the first electronic autocollimator theodolite 8, and clear the azimuth angle α2 by the function of the second electronic autocollimator theodolite 9.

[0041] Rotate the first electronic autocollimator theodolite 8 and the second electronic autocollimator theodolite 9 by a certain angle to mutually aim, the purpose is to establish the relationship between the first electronic autocollimator theodolite 8 and the second electronic autocollimator theodolite 9, so as to determine the angle deviation between the current angle of the cube prism 6 and the primary mirror optical axis 10, and adjust the azimuth angle and the elevation angle of the cube prism 6 according to the angle deviation.

[0042] S5. Rotate the second electronic autocollimator theodolite 9 to re-aim the cube prism 6, and record the azimuth angle α2` and the elevation angle β2` of the second electronic autocollimator theodolite again.

[0043] Rotate the second electronic autocollimator theodolite 9 by a certain angle to re-aim the cube prism 6, at this time, record the azimuth angle α2` and the elevation angle β2` of the second electronic autocollimator theodolite, and the elevation angle β2` represents the current elevation angle of the cube prism optical axis 11.

[0044] S6. Adjust the azimuth angle and the elevation angle of the cube prism 6 to make the cube prism optical axis 11 completely coaxial with the primary mirror optical axis 10.

[0045] The cube prism optical axis 11 and the primary mirror optical axis 10 being completely coaxial needs to meet the following conditions:

[0046] α2` = 180° - α1`;

[0047] β2` = β1.

[0048] From the above conditions, setting the azimuth angle a1 to zero is to obtain the included angle between the line connecting the first electronic autocollimator theodolite 8 and the second electronic autocollimator theodolite 9 and the primary mirror optical axis 10, i.e. the azimuth angle a1 ', when the first electronic autocollimator theodolite 8 and the second electronic autocollimator theodolite 9 are mutually sighted. Setting the azimuth angle a2 to zero is to obtain the included angle between the line connecting the first electronic autocollimator theodolite 8 and the second electronic autocollimator theodolite 9 and the cubic prism optical axis 11, i.e. the azimuth angle a2 ', when the first electronic autocollimator theodolite 8 and the second electronic autocollimator theodolite 9 are mutually sighted.

[0049] When the azimuth angle a2'and the elevation angle b2'are ideal values, the azimuth angle a1'and the azimuth angle a2'are complementary angles, and the elevation angle b2'is equal to the elevation angle b1, so the cubic prism optical axis 11 and the primary mirror optical axis 10 are completely coaxial.

[0050] When the cubic prism optical axis 11 and the primary mirror optical axis 10 are not completely coaxial, the azimuth angle a2'and the elevation angle b2'deviate from the ideal values, and the azimuth angle and the elevation angle of the cubic prism 6 are adjusted according to the deviation values, so as to realize the adjustment of the azimuth angle a2'and the elevation angle b2 ', until a2 = 180°- a1 ', b2 = b1, and thus the high-precision replacement of the cubic prism optical axis 11 to the primary mirror optical axis 10 is completed, and the high-precision establishment and transmission of the primary mirror optical axis 10 are realized.

[0051] More specifically, the adjustment of the azimuth angle of the cubic prism 6 is realized by the adjustment of the screw in the through hole, and the adjustment of the elevation angle of the cubic prism 6 is realized by grinding the bottom surface of the prism fixing seat 7.

[0052] The cubic prism 6 is a high-precision plane mirror except the bottom surface, and the angle error between the adjacent surfaces is usually controlled within a very small range, only 2-5", and the angle measurement accuracy of the first electronic autocollimator theodolite 8 and the second electronic autocollimator theodolite 9 can reach 0.5". Ignoring the small amount of eye sighting error inherent in visual optical instruments, the accuracy control of the primary mirror optical axis 10 establishment and transmission can be ensured within 5". Therefore, the primary mirror optical axis 10 established and transmitted by using the method can determine the angular relationship with the features in the spatial dimension, and thus has an important guiding role for optical assembly and adjustment.

[0053] It should be understood that the various forms of flow shown above can be reordered, additional steps added, or steps deleted. For example, the steps described in the present disclosure can be executed in parallel, in series, or in a different order, as long as the desired results of the technical solutions of the present disclosure can be achieved, which is not limited herein.

[0054] The above detailed description does not limit the scope of the application. Various modifications, combinations, sub-combinations and alternatives can be made to the detailed embodiment within the scope of the application. Any modification, equivalent replacement and improvement made without departing from the spirit and principle of the application shall fall within the scope of the application.

Claims

1. A method for high-precision establishment and transmission of the optical axis of a telescope primary mirror, characterized in that, The method comprises the following steps: S1. Constructing a detection light path for detecting the surface shape of a telescope primary mirror installed on a primary mirror support structure; wherein the detection light path comprises an interferometer and a compensator installed with a standard plane mirror, and when the detection light path is aligned with the telescope primary mirror, the telescope primary mirror, the compensator and the interferometer are coaxial; S2. Using a first electronic autocollimator theodolite to aim at the standard plane mirror through the central hole of the telescope primary mirror, recording the azimuth angle α1 and the elevation angle β1 of the first electronic autocollimator theodolite, and using the self-function of the first electronic autocollimator theodolite to clear the azimuth angle α1; S3. Installing a cubic prism on the side wall of the primary mirror support structure through a prism fixing seat, using a second electronic autocollimator theodolite to aim at the cubic prism, and recording the azimuth angle α2 and the elevation angle β2 of the second electronic autocollimator theodolite; S4. Rotating the first electronic autocollimator theodolite and the second electronic autocollimator theodolite to aim at each other, at this time recording the azimuth angle α1' of the first electronic autocollimator theodolite, and using the self-function of the second electronic autocollimator theodolite to clear the azimuth angle α2; S5. Rotating the second electronic autocollimator theodolite to aim at the cubic prism again, and recording the azimuth angle α2' and the elevation angle β2' of the second electronic autocollimator theodolite again; S6. Adjusting the azimuth angle and the elevation angle of the cubic prism to make the optical axis of the cubic prism coaxial with the optical axis of the telescope primary mirror; wherein the coaxial condition of the optical axis of the cubic prism and the optical axis of the telescope primary mirror is as follows: α2`＝180°-α1`； β2`＝β1。 2. The method for high-precision establishment and transfer of the optical axis of a telescope primary mirror according to claim 1, characterized in that, When the optical axis of the cubic prism is not coaxial with the optical axis of the telescope primary mirror, the deviation of the azimuth angle α2' and the elevation angle β2' of the cubic prism in the current state from the ideal value is calculated, and the azimuth angle and the elevation angle of the cubic prism are adjusted according to the deviation values of the azimuth angle and the elevation angle, until α2=180°-α1', β2=β1.

3. The method for high-precision establishment and transfer of the optical axis of a telescope primary mirror according to claim 2, characterized in that, The cubic prism is bonded on the prism fixing seat, threaded holes are processed on the side wall of the primary mirror support structure, the prism fixing seat is fixed on the side wall of the primary mirror support structure through screws, through holes are processed on the prism fixing seat, and the diameter of the through holes is greater than the diameter of the screws.

4. The method for high-precision establishment and transfer of the optical axis of a telescope primary mirror according to claim 3, characterized in that, The azimuth angle of the cubic prism is adjusted through the adjustment of the screws in the through holes.

5. The method for high-precision establishment and transfer of the optical axis of a telescope primary mirror according to claim 2, characterized in that, The elevation angle of the cubic prism is adjusted by grinding the bottom surface of the prism fixing seat.

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