Wavefront correction deformable mirror device

Abstract

The invention relates to the technical field of deformable mirrors, in particular to a wavefront correction deformable mirror device which comprises a mirror body and a main mirror chamber, a connecting assembly is arranged between the mirror body and the main mirror chamber, a plurality of actuator assemblies are installed on the main mirror chamber, and the connecting assembly comprises a supporting piece and a protective piece which are installed on the main mirror chamber. The actuator assembly comprises an adhesive head, an off-axis correction flexible joint, a driver, an axial pre-tightening piece and a pressing piece which are sequentially arranged and connected together. The supporting piece is matched with the off-axis correction flexible joint, the adaptability of the device in different temperature environments is effectively improved, the assembly difficulty is reduced, the convenience and efficiency of assembly and maintenance are improved, meanwhile, the pre-tightening force is increased between the actuator assembly and the mirror body, the response speed and precision of the actuator are improved, and the service life of the actuator assembly is prolonged. The stability and the reliability of the optical system are integrally and effectively improved, and the pre-tightening force between the actuator assembly and the lens body can be adjusted after the axial pre-tightening piece is pressed by the pressing piece.

Description

Technical Field

[0001] The present invention relates to the technical field of deformable mirrors, and particularly to a wavefront correction deformable mirror device. Background Art

[0002] With the wide application of modern optical systems in high-precision imaging and optical measurement, especially in the field of deep ultraviolet (DUV) optical imaging, wavefront correction has become one of the key technologies to ensure system performance. Wavefront aberration is caused by various errors or imperfections in the optical system, which will seriously affect the imaging quality. In the deep ultraviolet optical band, the imaging quality requirements of the objective lens are extremely high, and it is particularly sensitive to wavefront errors. Even a tiny aberration may cause image blurring or distortion. Therefore, wavefront correction of deep ultraviolet objective lenses has become an important technical problem.

[0003] Wavefront correction is mainly achieved by driving the mirror surface to deform through the displacement of actuators. The correction accuracy and speed of existing wavefront correction deformable mirror devices still need to be further improved. Their correction accuracy and speed are easily affected by environmental temperature changes and installation errors. Due to the difference in the thermal expansion coefficients of materials, the deformation of the deformable mirror will be significantly affected by temperature fluctuations, resulting in unstable wavefront correction of the deformable mirror in different working environments, and thus reducing its correction accuracy. Secondly, the number of actuators is large and the installation space is limited. The installation accuracy requirements are high and the installation adjustment is difficult. Therefore, existing wavefront correction deformable mirror devices are prone to installation errors, which reduce the correction accuracy and speed, and then reduce the stability and reliability of the optical system. Summary of the Invention

[0004] The present invention provides a wavefront correction deformable mirror device to solve the problems in related technologies that the wavefront correction deformable mirror device is easily affected by environmental temperature changes and installation errors, resulting in reduced correction accuracy and speed, and further affecting the stability and reliability of the optical system.

[0005] The present invention provides a wavefront correction deformable mirror device, which includes a mirror body and a main mirror chamber. A connection assembly is provided between the mirror body and the main mirror chamber. A plurality of actuator assemblies are installed on the main mirror chamber. The mirror body is installed on one side of the main mirror chamber through the connection assembly. The actuator assemblies are loaded into the main mirror chamber from the other side and connected to the mirror body, and the plurality of actuator assemblies are evenly distributed in an array. The connection assembly includes a support member and a protective member installed on the main mirror chamber. The support member is connected to the side surface of the mirror body and is a single-degree-of-freedom flexible hinge structure, and is used to automatically compensate for the deformation difference between the mirror body and the support member due to temperature changes; the protective member limits the mirror body from the end face. The actuator assembly includes an adhesive head, an off-axis correction flexure, a driver, an axial pre-tightening member, and a pressing member that are arranged in sequence and connected together. The adhesive head is connected to the mirror body. The main mirror chamber limits the adhesive head in the radial direction to form a first limiting area. The pressing member is threadedly connected to the main mirror chamber and presses the axial pre-tightening member to form a pre-tightening force between the actuator assembly and the mirror body. The axial pre-tightening member is threadedly connected to the driver. After the pressing member is tightened, the pre-tightening force between the actuator assembly and the mirror body is adjusted by rotating the axial pre-tightening member.

[0006] In a possible implementation manner, the thread connection direction between the axial pre-tightening member and the driver is opposite to the thread connection direction between the pressing member and the main mirror chamber.

[0007] In a possible implementation manner, an internal hexagonal adjustment area is provided on the axial pre-tightening member, and a through groove is opened on the pressing member. An external internal hexagonal wrench passes through the through groove and cooperates with the internal hexagonal adjustment area to control the rotation of the axial pre-tightening member.

[0008] In a possible implementation manner, an annular groove is opened on the axial pre-tightening member. The pressing member includes a connection seat provided with an annular platform. The annular platform cooperates with the annular groove to limit the axial pre-tightening member in the radial direction, and the annular platform is threadedly connected to the main mirror chamber.

[0009] In a possible implementation manner, the plurality of actuator assemblies are axially symmetrically distributed in a hexagon.

[0010] In a possible implementation manner, the number of the support members and the protective members is several, and both are evenly distributed along the circumference of the mirror body and the support members and the protective members are alternately distributed in sequence.

[0011] In a possible implementation manner, a plurality of convex points are provided on the mirror body, and the convex points correspond to the actuator assemblies one by one. Grooves matching the convex points are opened on the adhesive heads.

[0012] One or more of the above technical solutions in the embodiments of the present invention have at least one of the following technical effects: 1. The present invention uses a support member in cooperation with an off-axis correction flexure to effectively improve the adaptability of the present invention in different temperature environments, reduce the assembly difficulty, improve the convenience and efficiency of assembly and maintenance. At the same time, a pre-tightening force is increased between the actuator assembly and the mirror body, improving the speed and accuracy of actuator response. Overall, the stability and reliability of the optical system are effectively improved. Moreover, the pre-tightening force between the actuator assembly and the mirror body can be adjusted after the pressing member presses the axial pre-tightening member, effectively improving the convenience of maintenance disassembly, installation and adjustment of the present invention, and ensuring the stability and reliability of the long-term operation of the optical system.

[0013] 2. In the present invention, the thread connection direction between the axial pre-tightening member and the driver is opposite to the thread connection direction between the pressing member and the main mirror chamber. An internal hexagon adjustment area is provided on the axial pre-tightening member. By cooperating the internal hexagon wrench with the internal hexagon adjustment area, the rotation of the axial pre-tightening member can be controlled, further improving the convenience of maintenance and installation adjustment. Moreover, the pressing member and the main mirror chamber will not become loose during the process of increasing the pre-tightening force, ensuring the stability of the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of the mirror body and the main mirror chamber of a wavefront correction deformable mirror device provided by an embodiment of the present invention.

[0015] Figure 2 is a schematic partial structural diagram of a wavefront correction deformable mirror device provided by an embodiment of the present invention.

[0016] Figure 3 is a schematic cross-sectional structural diagram of a wavefront correction deformable mirror device provided by an embodiment of the present invention.

[0017] Figure 4 is Figure 3 the enlarged view of part A in

[0018] Figure 5 is a schematic structural diagram of an actuator assembly of a wavefront correction deformable mirror device provided by an embodiment of the present invention.

[0019] Figure 6 is a schematic structural diagram of a support member of a wavefront correction deformable mirror device provided by an embodiment of the present invention.

[0020] In the figure: 1. Mirror body; 2. Main mirror chamber; 3. Connection assembly; 31. Support member; 32. Protective member; 4. Actuator assembly; 41. Adhesive head; 42. Off-axis correction flexure; 43. Driver; 44. Axial pre-tightening member; 45. Pressing member; 451. Ring platform; 452. Connection seat; 46. Internal hexagon adjustment area; 47. Through groove; 48. Ring groove; 49. Groove; 5. Bump. Detailed Embodiments

[0021] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following detailed description of the specific embodiments of the present invention will be given in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described below, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0022] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 5 A wavefront correction deformable mirror device, including a mirror body 1 and a main mirror chamber 2. There is a connection assembly 3 between the mirror body 1 and the main mirror chamber 2. A number of actuator assemblies 4 are installed on the main mirror chamber 2. The mirror body 1 is installed on the front side of the main mirror chamber 2 through the connection assembly 3. The actuator assemblies 4 are inserted into the main mirror chamber 2 from the rear side and connected to the mirror body 1, and the actuator assemblies 4 can also be disassembled and replaced from the rear side. A number of actuator assemblies 4 are distributed symmetrically in a hexagon (as shown in Figure 2 ), a total of nineteen independent actuator assemblies 4. The actuator assemblies 4 are responsible for adjusting the shape of the mirror body 1 in real time, accurately correcting the wavefront error, improving the imaging accuracy of the deep ultraviolet objective lens, and ensuring the imaging quality.

[0023] Refer to Figure 1 、 Figure 3 and Figure 6 The connection assembly 3 includes a support member 31 and a protective member 32 installed on the main mirror chamber 2. Both the support member 31 and the protective member 32 are detachably and fixedly installed on the main mirror chamber 2 through threaded fasteners. The number of support members 31 is several and they are evenly distributed along the circumference of the mirror body 1, as shown in Figure 1 . The number of support members 31 is three and they are connected to the side surface of the mirror body 1 by bonding, providing a supporting force for the mirror body 1 from the side surface to ensure the stability of the position accuracy of the mirror body 1. And the support member 31 is a single-degree-of-freedom flexible hinge structure. When the environmental temperature changes to cause different deformation amounts of the mirror body 1 and the support member 31, the support member 31 of the single-degree-of-freedom flexible hinge structure will automatically provide appropriate flexible compensation, reducing the wavefront error caused by the inconsistent deformation of the mirror body 1 and the support member 31, and thus improving the stability of the correction performance of the present invention at different temperatures.

[0024] Refer to Figure 1 and Figure 3 The number of protective members 32 is several and the protective members 32 limit the mirror body 1 from the edge of the front end face of the mirror body 1, as shown in Figure 1As shown, the number of protective members 32 is three and they are evenly distributed along the circumferential direction of the mirror body 1. The protective members 32 and the support members 31 are alternately distributed in sequence, improving the evenness of the force on the mirror body 1 and further facilitating the improvement of the stability of the position accuracy of the mirror body 1.

[0025] Refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , the actuator assembly 4 includes an adhesive head 41, an off-axis correction flexure 42, a driver 43, an axial pre-tightening member 44, and a pressing member 45 that are sequentially arranged from front to back and connected together. The adhesive head 41 is connected to the mirror body 1 in an adhesive manner, and the main mirror chamber 2 limits the adhesive head 41 in the radial direction; as Figure 3 shown, a number of installation cavities in the shape of a cylindrical structure for installing the actuator assembly 4 are provided on the main mirror chamber 2. The adhesive head 41 is a circular seat with a frustum on the front side, and the circumferential side surface of the circular seat is in contact with the inner side surface of the installation cavity, thereby playing a role in limiting the adhesive head 41 to a certain extent without affecting the axial movement of the actuator assembly 4; the off-axis correction flexure 42 is connected to the adhesive head 41 by means of a threaded fastener and is connected to the driver 43 by means of bonding, and the off-axis correction flexure 42 is an existing X-Flexure flexure. As Figure 5 shown, the circular cut on the off-axis correction flexure 42 releases the rotational degrees of freedom in two directions perpendicular to the axial direction, effectively absorbing and compensating for the small misalignment errors that occur during the installation process, and correspondingly reducing the requirements for the installation accuracy of the actuator assembly 4. Among them, the driver 43 can be a piezoelectric ceramic motor.

[0026] Refer to Figure 3 , Figure 4 and Figure 5 , the pressing member 45 is threadedly connected to the main mirror chamber 2 and presses the axial pre-tightening member 44. Combining the limitation of the mirror body 1 by the protective member 32 from the front end, a pre-tightening force is stably formed between the actuator assembly 4 and the mirror body 1, improving the response speed and accuracy of the actuator assembly 4, and further improving the correction speed and accuracy of the present invention. Moreover, the axial pre-tightening member 44 is threadedly connected to the driver 43. After the pressing member 45 presses the axial pre-tightening member 44, rotating the axial pre-tightening member 44 can adjust the distance between the pressing member 45 and the driver 43, and further adjust the pre-tightening force between the actuator assembly 4 and the mirror body 1, correspondingly improving the installation and maintenance efficiency and convenience of the deformable mirror device. Among them, the direction of the threaded connection between the axial pre-tightening member 44 and the driver 43 is opposite to the direction of the threaded connection between the pressing member 45 and the main mirror chamber 2. During the process of rotating the axial pre-tightening member 44 to increase the pre-tightening force, the pressing member 45 will not become loose from the main mirror chamber 2, ensuring the stability of its connection.

[0027] Refer to Figure 3And Figure 4 An internal hexagon adjustment area 46 is provided on the axial pre-tightening member 44, and a through slot 47 is formed on the pressing member 45. An external internal hexagon wrench passes through the through slot 47 and cooperates with the internal hexagon adjustment area 46 to control the rotation of the axial pre-tightening member 44, facilitating the adjustment of the pre-tightening force after the deformable mirror device is assembled.

[0028] Refer to Figure 3 And Figure 4 A circular groove 48 is formed on the axial pre-tightening member 44. The pressing member 45 includes a connecting seat 452 provided with a circular platform 451. The circular platform 451 is threadedly connected to the main mirror chamber 2, and the circular platform 451 cooperates with the circular groove 48 to limit the axial pre-tightening member 44 in the radial direction, further improving the assembly accuracy.

[0029] Refer to Figure 2 、 Figure 3 And Figure 5 A plurality of bump 5 with a cylindrical structure are provided on the mirror body 1. The bumps 5 correspond to the actuator assemblies 4 one by one. A groove 49 that cooperates with the bumps 5 is formed on the adhesive head 41. The bumps 5 are inserted into the grooves 49 to connect the adhesive head 41 and the mirror body 1 together. On the one hand, it facilitates the connection and installation, and on the other hand, it is beneficial to improve the connection accuracy and the stability after connection.

[0030] In the embodiments of the present invention, unless otherwise clearly specified and limited, 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 indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" 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", "below" and "beneath" 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.

[0031] In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "arranged", "connected", "installed", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection, or a sliding connection; 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 components. 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 situations.

[0032] The embodiments of the present specific implementation manners are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A wavefront correction deformable mirror device, comprising a mirror body and a primary mirror chamber, characterized in that: A connection assembly is provided between the mirror body and the main mirror chamber, and a plurality of actuator assemblies are installed on the main mirror chamber. The mirror body is installed on one side of the main mirror chamber through the connection assembly, and the actuator assembly is installed into the main mirror chamber from the other side and connected to the mirror body, and the plurality of actuator assemblies are evenly distributed in an array; The connecting assembly includes a support member and a protective member installed on the main mirror chamber. The support member is connected to the side of the mirror body and is a single-degree-of-freedom flexible hinge structure, and is used to automatically compensate for the deformation difference of the mirror body and the support member caused by temperature changes. The protective member limits the mirror body from the end surface; The actuator assembly includes an adhesive head, an off-axis correction joint, a driver, an axial preload and a pressing member which are arranged and connected in sequence. The adhesive head is connected to the mirror body, the pressing member is threadedly connected to the main mirror chamber and presses the axial preload to form a preload force between the actuator assembly and the mirror body, and the axial preload is threadedly connected to the driver. After the pressing member is pressed, the preload force between the actuator assembly and the mirror body is adjusted by rotating the axial preload.

2. A wavefront correction deformable mirror device according to claim 1, characterized in that: The threaded connection direction between the axial preload member and the driver is opposite to the threaded connection direction between the pressing member and the primary mirror chamber.

3. A wavefront correction deformable mirror device according to claim 1 or 2, characterized in that: The axial preload member is provided with an inner hexagonal adjustment area, and the pressing member is provided with a through slot. An external inner hexagonal wrench passes through the through slot and cooperates with the inner hexagonal adjustment area to control the rotation of the axial preload member.

4. A wavefront correction deformable mirror device according to claim 1 or 2, characterized in that: The axial preload member is provided with an annular groove, and the pressing member comprises a connecting seat provided with an annular platform, the annular platform cooperates with the annular groove to limit the axial preload member in radial direction, and the annular platform is threadedly connected with the main mirror chamber.

5. A wavefront correction deformable mirror device according to claim 1, characterized in that: Several of the actuator assemblies are distributed in a hexagonal axisymmetric manner.

6. A wavefront correction deformable mirror device according to claim 1, characterized in that: The number of the supporting members and the protecting members are both several, and both are evenly distributed along the circumference of the mirror body, and the supporting members and the protecting members are alternately distributed in sequence.

7. A wavefront correction deformable mirror device according to claim 1, characterized in that: The mirror body is provided with a plurality of protrusions, which correspond to the actuator components one by one, and the adhesive head is provided with grooves which match the protrusions.

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