Linear secondary mirror focusing device

Abstract

The invention provides a linear secondary mirror focusing device, and the device comprises a secondary mirror installation seat which is used for installing a secondary mirror to be focused; the linear displacement assembly is connected with the secondary mirror mounting seat, and the linear displacement assembly is used for driving the secondary mirror mounting seat to linearly move; one end of the piezoelectric driving assembly is in contact with the linear displacement assembly, and the piezoelectric driving assembly is used for driving the linear displacement assembly to perform bidirectional linear displacement through a contact point so as to focus the secondary mirror. The problem of secondary mirror focusing in the field of laser communication is solved, linear focusing of the secondary mirror is completed in a stepping piezoelectric actuation mode, the precision and efficiency of a focusing system are improved, and precision and miniaturization of a focusing device are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser communication, and particularly to a linear secondary mirror focusing device. Background Art

[0002] In the technical field of laser communication, due to the impact and vibration of the system and the changes of external environmental factors such as temperature and pressure, the focal plane of the optical system will produce a certain amount of offset, and secondary mirror zoom is required to ensure the coupling efficiency and robustness of the optical system. Therefore, a high-precision and high-stability secondary mirror focusing device will be an important part of the laser communication terminal.

[0003] In the related art, the secondary mirror focusing devices of telescopes mainly adopt screw-nut focusing and cam focusing, and use motors to drive, converting the linear motion of the motors into linear motion. The screw-nut focusing has a simple structure and a lower requirement for machining accuracy, but complex motor control is required to ensure the accuracy; the cam focusing has a higher accuracy but a larger size, and requires strict machining accuracy. At the same time, when these two focusing mechanisms convert the rotational motion of the motor into linear motion, it is easy to cause return error and generate additional frictional load, which has a certain impact on the working accuracy and efficiency of the device. Summary of the Invention

[0004] The present invention provides a linear secondary mirror focusing device to solve the above technical problems.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An embodiment of the present invention provides a linear secondary mirror focusing device, including: a secondary mirror mounting seat for mounting the secondary mirror to be focused; a linear displacement assembly connected to the secondary mirror mounting seat, the linear displacement assembly being used to drive the secondary mirror mounting seat to move linearly; a piezoelectric driving assembly, one end of the piezoelectric driving assembly being in contact with the linear displacement assembly, the piezoelectric driving assembly being used to drive the linear displacement assembly to perform bidirectional linear displacement through the contact point so as to focus the secondary mirror.

[0007] The linear secondary mirror focusing device provided by the present invention further has the following additional technical features:

[0008] According to an embodiment of the present invention, the above linear secondary mirror focusing device further includes: a displacement detection assembly for detecting and feeding back the displacement of the linear displacement assembly.

[0009] According to an embodiment of the present invention, the linear displacement assembly includes: a linear guide rail, two sets of pressing block gaskets, two sets of ceramic balls, two sets of ceramic ball pressing blocks, a guide rail limiting block, a main body, and a rear cover. Among them, the linear guide rail is connected to the secondary mirror mounting seat, and the linear guide rail performs linear displacement under the action of the piezoelectric drive assembly to complete the focusing operation of the secondary mirror. Each set of ceramic ball pressing blocks, in cooperation with a set of pressing block gaskets and a set of ceramic balls, are respectively arranged on both sides of the linear guide rail to apply radial pressure to the linear guide rail; the guide rail limiting block cooperates with the structure of the main body to limit the maximum displacement of the linear guide rail; the rear cover is connected to the main body.

[0010] According to an embodiment of the present invention, the piezoelectric drive assembly includes: a rhombus preload; a ceramic wafer, which is bonded to the end of the rhombus preload as the contact point with the linear guide rail; a preload spring, one end of which is connected to the rhombus preload; a set screw, one end of which is connected to the other end of the preload spring, and the set screw is threadedly connected to the main body to apply a centripetal force to the ceramic wafer to make the ceramic wafer closely fit the linear guide rail; a piezoelectric ceramic, which is tightly installed in the rhombus structure of the rhombus preload, and the maximum plastic deformation of the rhombus structure is greater than the electrostrictive amount generated by the piezoelectric ceramic.

[0011] According to an embodiment of the present invention, the displacement detection assembly includes: a sensor adapter rod, a sensor gland, an LVDT (Linear Variable Displacement Transducer) displacement sensor core rod, and a housing. Among them, the sensor gland and the housing are fixed to the main body, and the LVDT displacement sensor core rod is fixedly connected to the linear guide rail through the sensor adapter rod to detect and feedback the displacement of the linear guide rail.

[0012] The present invention has the following beneficial effects:

[0013] The present invention solves the problem of secondary mirror focusing in the field of laser communication, uses the stepping piezoelectric actuation method to complete the linear focusing of the secondary mirror, improves the accuracy and efficiency of the focusing system, and realizes the precision and miniaturization of the focusing device. Description of the Drawings

[0014] Figure 1 is a cross-sectional schematic view of a linear secondary mirror focusing device according to an embodiment of the present invention;

[0015] Figure 2 is a front view of a linear secondary mirror focusing device according to an embodiment of the present invention;

[0016] Reference numerals: secondary mirror mounting base 1, linear displacement assembly 2, piezoelectric drive assembly 3, displacement detection assembly 4, linear guide 21, two sets of pressure block gaskets 22, two sets of ceramic balls 23, two sets of ceramic ball pressure blocks 24, guide rail limit block 25, main body 26, rear cover 27, diamond preload 31, ceramic wafer 32, preload spring 33, set screw 34, piezoelectric ceramic 35, sensor adapter rod 41, sensor gland 42, LVDT displacement sensor core rod 43 and housing 44. Detailed implementation mode

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] Next, the linear secondary mirror focusing device in the embodiment of the present invention will be described in conjunction with the accompanying drawings.

[0019] Figure 1 is a cross-sectional schematic diagram of a linear secondary mirror focusing device according to an embodiment of the present invention. Figure 2 is a front view of a linear secondary mirror focusing device according to an embodiment of the present invention.

[0020] As Figure 1-2 shown, the linear secondary mirror focusing device includes: a secondary mirror mounting base 1, a linear displacement assembly 2, and a piezoelectric drive assembly 3.

[0021] Among them, the secondary mirror mounting base 1 is used to mount the secondary mirror to be focused; the linear displacement assembly 2 is connected to the secondary mirror mounting base 1, and the linear displacement assembly 2 is used to drive the secondary mirror mounting base to move linearly; one end of the piezoelectric drive assembly 3 contacts the linear displacement assembly 2, and the piezoelectric drive assembly 3 is used to drive the linear displacement assembly 2 to perform bidirectional linear displacement through the contact point to focus the secondary mirror.

[0022] Specifically, the secondary mirror to be focused is mounted on the secondary mirror mounting base 1. The piezoelectric drive assembly 3 can drive the linear displacement assembly 2 to perform bidirectional linear displacement within the stroke through the step-by-step piezoelectric actuation method, thereby driving the secondary mirror to move and realizing the focusing of the secondary mirror. Thus, the problem of secondary mirror focusing in the field of laser communication is solved. The step-by-step piezoelectric actuation method is used to complete the linear focusing of the secondary mirror, improving the accuracy and efficiency of the focusing system, and realizing the precision and miniaturization of the focusing device.

[0023] In an embodiment of the present invention, as Figure 1 shown, the above-mentioned linear secondary mirror focusing device may further include: a displacement detection assembly 4, and the displacement detection assembly 4 is used to detect and feedback the displacement of the linear displacement assembly 2.

[0024] In a specific embodiment of the present invention, as Figure 2 shown, the linear displacement assembly 2 includes: a linear guide rail 21, two groups of press block gaskets 22, two groups of ceramic balls 23, two groups of ceramic ball press blocks 24, a guide rail limit block 25, a main body 26 and a rear cover 27.

[0025] Among them, the linear guide rail 21 is connected to the secondary mirror mounting seat 1, and the linear guide rail 21 performs linear displacement under the action of the piezoelectric drive assembly 3 to complete the focusing action of the secondary mirror. Each group of ceramic ball press blocks 24 cooperates with a group of press block gaskets 22 and a group of ceramic balls 23 and are respectively arranged on both sides of the linear guide rail 21 to apply radial pressure to the linear guide rail 21; the guide rail limit block 25 cooperates with the structure of the main body 26 to limit the maximum displacement of the linear guide rail 21; the rear cover 27 is connected to the main body 26.

[0026] Specifically, the ceramic balls 23 include four, with two in a group. One group of ceramic ball press blocks 24 cooperates with a group of press block gaskets 22 and a group of ceramic balls 23 and are arranged on one side of the linear guide rail 21, and the other group of ceramic ball press blocks 24 cooperates with another group of press block gaskets 22 and another group of ceramic balls 23 and are arranged on the other side of the linear guide rail 21 to ensure the guiding accuracy of the linear guide rail 21. The guide rail limit block 25 cooperates with the structure of the main body 26 to limit the maximum displacement of the linear guide rail 21; the rear cover 27 is connected to the main body 26, playing a role of protection and aesthetics.

[0027] In an embodiment of the present invention, as Figure 1 shown, the piezoelectric drive assembly 3 includes: a rhombus preload 31, a ceramic wafer 32, a preload spring 33, a set screw 34 and a piezoelectric ceramic 35.

[0028] Among them, the ceramic wafer 32 is bonded to the end of the rhombus preload 31 as the contact point with the linear guide rail 21; one end of the preload spring 33 is connected to the rhombus preload 31; one end of the set screw 34 is connected to the other end of the preload spring 33, and the set screw 34 is threadedly connected to the main body 26 to apply a centripetal force to the ceramic wafer 32 to make the ceramic wafer 32 closely fit the linear guide rail 21; the piezoelectric ceramic 35 is tightly installed in the rhombus structure of the rhombus preload 31, and the maximum plastic deformation of the rhombus structure is greater than the electrostrictive amount generated by the piezoelectric ceramic 35.

[0029] Specifically, the ceramic wafer 32 is bonded to the end of the diamond preload 31, serving as the contact point with the linear guide 21. The two ends of the preload spring 33 are respectively connected to the diamond preload 31 and the set screw 34. The set screw 34 is threadedly connected to the main body 26, thereby applying a centripetal force to the ceramic wafer 32 to make it closely fit the linear guide 21. The piezoelectric ceramic 35 is tightly installed in the diamond structure of the diamond preload 31. Since the maximum plastic deformation of the diamond structure is greater than the electrostrictive amount generated by the piezoelectric ceramic 35, the ceramic wafer 32 fixed at the end of the diamond preload 31 and the piezoelectric ceramic 35 have the same-direction displacement. By controlling the elongation and contraction speeds of the piezoelectric ceramic 35 of the piezoelectric drive assembly 3, the bidirectional linear displacement of the linear guide 21 can be achieved under the action of inertial force.

[0030] In an embodiment of the present invention, as Figure 1 shown, the displacement detection assembly 4 may include: a sensor adapter rod 41, a sensor gland 42, an LVDT displacement sensor core rod 43, and a housing 44. Among them, the sensor gland 42 and the housing 44 are fixed to the main body 26, and the LVDT displacement sensor core rod 43 is fixedly connected to the linear guide 21 through the sensor adapter rod 41 to detect and feedback the displacement of the linear guide 21.

[0031] Specifically, the LVDT displacement sensor core rod 43 is fixedly connected to the linear guide 21 through the sensor adapter rod 41 and moves together with the linear guide 21, so as to detect and feedback the displacement of the linear guide 21.

[0032] In summary, according to the linear secondary mirror focusing device of the embodiment of the present invention, it includes: a secondary mirror mounting seat for mounting the secondary mirror to be focused; a linear displacement assembly connected to the secondary mirror mounting seat for driving the secondary mirror mounting seat to linearly move; a piezoelectric drive assembly, one end of which is in contact with the linear displacement assembly for driving the linear displacement assembly to perform bidirectional linear displacement through the contact point to focus the secondary mirror. Thus, the problem of secondary mirror focusing in the field of laser communication is solved. The linear focusing of the secondary mirror is completed by the step-by-step piezoelectric actuation method, which improves the accuracy and efficiency of the focusing system and realizes the precision and miniaturization of the focusing device.

[0033] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0034] In addition, the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0035] In the present invention, unless otherwise clearly specified and defined, terms such as "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0037] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0038] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A linear secondary mirror focusing device, characterized in that, Comprising: A secondary mirror mount for mounting the secondary mirror to be focused; A linear displacement component connected to the secondary mirror mount and used to drive the secondary mirror mount to linearly move; A piezoelectric drive component, one end of which contacts the linear displacement component, and the piezoelectric drive component is used to drive the linear displacement component to perform bidirectional linear displacement through the contact point to focus the secondary mirror.

2. The linear secondary mirror focusing device according to claim 1, characterized in that, Further comprising: A displacement detection component for detecting and feedbacking the displacement of the linear displacement component.

3. The linear secondary mirror focusing device according to claim 1, wherein The linear displacement component includes: a linear guide rail, two sets of pressure block gaskets, two sets of ceramic balls, two sets of ceramic ball pressure blocks, a guide rail limit block, a main body and a rear cover, wherein, the linear guide rail is connected to the secondary mirror mount, and the linear guide rail performs linear displacement under the action of the piezoelectric drive component to complete the focusing action of the secondary mirror. Each set of ceramic ball pressure blocks, in cooperation with a set of pressure block gaskets and a set of ceramic balls, are respectively arranged on both sides of the linear guide rail to apply radial pressure to the linear guide rail; the guide rail limit block cooperates with the structure of the main body to limit the maximum displacement of the linear guide rail; the rear cover is connected to the main body.

4. The linear secondary mirror focusing device according to claim 3, wherein, The piezoelectric drive component includes: Rhombic preloading; A ceramic wafer bonded to the end of the rhombic preloading as the contact point with the linear guide rail; A preloading spring, one end of which is connected to the rhombic preloading; A set screw, one end of which is connected to the other end of the preloading spring, and the set screw is threadedly connected to the main body to apply a centripetal force to the ceramic wafer to make the ceramic wafer closely fit the linear guide rail; A piezoelectric ceramic tightly installed in the rhombic structure of the rhombic preloading, and the maximum plastic deformation of the rhombic structure is greater than the electrostrictive amount generated by the piezoelectric ceramic.

5. The linear secondary mirror focusing device according to claim 3, characterized in that, The displacement detection component includes: a sensor adapter rod, a sensor gland, an LVDT displacement sensor core rod and a housing. Among them, the sensor gland and the housing are fixed on the main body, and the LVDT displacement sensor core rod is fixedly connected to the linear guide rail through the sensor adapter rod to detect and feedback the displacement of the linear guide rail.

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