Macro-micro composite piezoelectric phase shifter

Abstract

The invention relates to the technical field of phase shifters, and discloses a macro-micro composite piezoelectric phase shifter which comprises a fixing frame, an adjusting frame, an elastic connecting assembly, a shell, a lens support and a piezoelectric actuator. The adjusting frame is arranged on the first cavity of the fixing frame. The elastic connecting assembly is arranged between the fixing frame and the adjusting frame. The lens support is arranged on the shell and covers the opening of the second cavity. The piezoelectric actuator is used for driving the lens support to be close to or away from the shell. The screw assembly is used for pushing the adjusting frame to be close to or away from the fixing frame, and the adjusting frame drives the shell and the lens support to move and is used for achieving deflection of the lens support. According to the invention, the deflection of the X-axis and the Y-axis can be manually adjusted, the ultra-fast stepping can be electrically controlled and adjusted, and the lens adjustment and the image shift stepping are combined, so that the device can be more conveniently applied to image shift, interference measurement and the like. The overall structure is reasonable and compact, space is saved, and meanwhile high precision and stability of precise positioning are guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of phase shifters, and more specifically, relates to a macro-micro composite piezoelectric phase shifter. Background Art

[0002] The phase shifter is designed specifically for optical detection phase shift applications and is also a very important component in a phase shift interferometer. Phase shift interference technology is widely used in precision optical measurement and the calibration and quality control of interference instruments. Phase shift interference technology introduces a known phase shift to generate interference images with a phase difference. By analyzing these interference images, the performance parameters of optical components or systems, such as surface shape, displacement, refractive index, etc., can be accurately measured. The function of the phase shifter is to generate an accurate movement at the micron level so that an accurate phase difference is generated in the interference image. The measurement error of the phase shift interferometer depends to a large extent on the phase shift error, that is, the movement error of the phase shifter. Existing phase shifters have the following problems: 1. The displacement adjustment method is single. The deflection adjustment of the lens and the image shift step are completed by independent mechanisms respectively, with a complex structure, occupying a large space, and being inconvenient for the integration of various optical systems; 2. The accuracy and stability of repeated positioning need to be improved.

[0003] Based on the above, the problem to be solved currently is to provide a macro-micro composite piezoelectric phase shifter with high accuracy, good stability, a compact structure, and capable of realizing X-axis and Y-axis deflection and Z-axis positioning. Summary of the Invention

[0004] The purpose of the present invention is to provide a macro-micro composite piezoelectric phase shifter, aiming to solve the problems in the prior art that the piezoelectric phase shifter cannot simultaneously achieve high-precision positioning of the X-axis, Y-axis deflection, and Z-axis, the accuracy and stability of repeated positioning are poor, and the structure is complex.

[0005] The present invention is realized as follows. A macro-micro composite piezoelectric phase shifter includes:

[0006] A fixed frame, which is provided with a first cavity and a first through hole;

[0007] An adjustment frame, which is arranged on the first cavity, and the adjustment frame is provided with a second through hole corresponding to the first through hole;

[0008] An elastic connection assembly, which is arranged between the fixed frame and the adjustment frame;

[0009] A housing, which includes a second cavity with an opening on one side. The housing sequentially passes through the first through hole and the second through hole and is fixed on the adjustment frame. The opening of the housing is close to the adjustment frame;

[0010] A lens bracket, which is arranged on the housing and covers the opening of the second cavity;

[0011] A piezoelectric actuator is disposed within the second cavity. Both ends of the piezoelectric actuator are respectively connected to the housing and the lens holder, and are used to drive the lens holder to approach or move away from the housing.

[0012] A screw component is disposed between the fixed frame and the adjustment frame, and is used to push the adjustment frame to approach or move away from the fixed frame; the adjustment frame drives the housing and the lens holder to move, so as to realize the deflection of the lens holder.

[0013] Further, the piezoelectric actuator includes a spacer, a pressure block, and a piezoelectric ceramic; the spacer and the pressure block are disposed opposite to each other, the pressure block is connected to the housing, the spacer is connected to the lens holder, the piezoelectric ceramic is annular and sleeved on the outer periphery of the spacer and the pressure block, and the spacer is an elastic structure, which is used to apply a pre-tightening force between the housing and the lens holder.

[0014] Further, a connecting rod is provided on one side of the lens holder close to the housing; the spacer includes a first step structure and a fourth through hole; the pressure block includes a second step structure and a columnar body, and the columnar body is provided with a connection hole for accommodating the connecting rod; the connecting rod passes through the fourth through hole and extends into the connection hole to be connected to the pressure block; the piezoelectric ceramic is sleeved on the first step structure and the second step structure.

[0015] Further, the screw component includes a screw, a screw sleeve threadedly connected to the screw, and a first ball and an adjustment block disposed within the first cavity;

[0016] A third through hole is provided on the side wall of the adjustment frame, and the screw sleeve is disposed within the third through hole; the screw passes through the screw sleeve and extends into the first cavity, and the end of the screw abuts against one side of the first ball, and the other side of the first ball abuts against the adjustment block; the adjustment block is disposed at the bottom of the adjustment frame, and the adjustment block is provided with a sliding groove allowing the first ball to roll, and the adjustment block drives the adjustment frame to approach or move away from the fixed frame under the push of the first ball.

[0017] Further, the adjustment frame is configured as a rectangle or a rectangle-like shape with chamfers, and the number of the screw components is 2. The two adjustment blocks are respectively disposed in the diagonal direction of the rectangle or the rectangle-like shape, and are used to push the adjustment frame to deflect around the X axis or around the Y axis;

[0018] Two adjacent sides of the adjustment frame are respectively parallel to the X axis and the Y axis, and the X axis and the Y axis are the plane rectangular coordinate axes.

[0019] Further, a second ball for support is also provided between the adjusting frame and the fixing frame, and grooves for accommodating the second ball are correspondingly provided on the adjusting frame and the fixing frame.

[0020] Further, the included angle formed by the connection lines between the centers of the second ball and the centers of the two adjusting blocks is a right angle or an approximate right angle.

[0021] Further, the chute forms a certain angle with the plane at the bottom of the adjusting frame.

[0022] Further, the elastic connection assembly includes a tension spring, a first pull rod and a second pull rod; both ends of the tension spring are respectively connected to the first pull rod and the second pull rod;

[0023] The fixing frame is provided with a blind hole or a through hole for installing the first pull rod, and the adjusting frame is provided with a blind hole or a through hole for installing the second rod.

[0024] Further, a connection frame for connecting with an external mechanism is also provided on the side wall of the fixing frame.

[0025] The beneficial effects of the macro-micro composite piezoelectric phase shifter provided by the present invention are as follows:

[0026] The setting of the screw rod assembly of the present invention can realize the manual control of the deflection angles of the lens in the X-axis and Y-axis directions; the setting of the piezoelectric actuator can realize the ultra-fast stepping of electric control, combining the lens adjustment with the image shift stepping, making it more convenient for applications such as image shift and interference measurement. The present invention supports two methods of macro manual adjustment and micro electric drive, can be integrated with most existing optical devices, and greatly improves the overall performance of the system. The macro-micro composite piezoelectric phase shifter of the present invention supports modular design, which is convenient for users to flexibly adjust and expand functions according to needs and adapt to the integration requirements of various optical systems.

[0027] The present invention adopts the structural design of direct drive by piezoelectric ceramics combined with a piezoelectric actuator, has a fast response speed, accurate positioning, can realize rapid progressive phase shift, can realize high-precision position adjustment at the nanometer level, and is suitable for dynamic optical systems.

[0028] The overall structure of the present invention is reasonable and compact, saves space while ensuring high precision and stability of precise positioning, and is suitable for optical devices that require a compact layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The front view of the macro-micro composite piezoelectric phase shifter provided by the present invention;

[0030] Figure 2 The Figure 1 A-A direction sectional view of the macro-micro composite piezoelectric phase shifter of the present invention;

[0031] Figure 3 The Figure 1 sectional view of the macro-micro composite piezoelectric phase shifter provided by the present invention in the B-B direction;

[0032] Figure 4 Exploded view of the macro-micro composite piezoelectric phase shifter provided by the present invention;

[0033] Figure 5 Partial exploded view of the macro-micro composite piezoelectric phase shifter provided by the present invention;

[0034] Figure 6 Schematic three-dimensional structure diagram of the fixing bracket provided by the present invention;

[0035] Figure 7 Schematic three-dimensional structure diagram of the spacer provided by the present invention;

[0036] Figure 8 Front view of the elastic connection assembly provided by the present invention;

[0037] In the figure: 1 - fixing bracket; 11 - first cavity; 12 - first through hole; 13 - third through hole; 2 - adjusting bracket; 21 - second through hole; 3 - elastic connection assembly; 31 - tension spring; 32 - first pull rod; 33 - second pull rod; 4 - housing; 41 - second cavity; 5 - lens bracket; 51 - connecting rod; 6 - piezoelectric actuator; 61 - spacer; 611 - first step structure; 612 - fourth through hole; 62 - pressing block; 621 - second step structure; 622 - columnar body; 623 - connection hole; 63 - piezoelectric ceramic; 7 - screw assembly; 71 - screw; 72 - screw sleeve; 73 - first ball; 74 - adjusting block; 741 - chute; 75 - locking nut; 8 - second ball; 9 - connecting frame; 10 - first bolt. Specific embodiments

[0038] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0040] In the drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be construed as a limitation of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0041] Referring to Figure 1-8 shown, it is a preferred embodiment provided by the present invention.

[0042] The macro-micro composite piezoelectric phase shifter includes a fixing frame 1, an adjusting frame 2, an elastic connection assembly 3, a housing 4, a lens holder 5, a piezoelectric actuator 6, and a screw assembly 7. Referring to Figure 1-3 .

[0043] The fixing frame 1 is provided with a first cavity 11. Referring to Figure 6 . A first through hole 12 is provided in the middle of the bottom surface of the fixing frame 1. The adjusting frame 2 is arranged above the first cavity 11 of the fixing frame 1. A second through hole 21 is provided in the middle of the adjusting frame 2 corresponding to the first through hole 12. The elastic connection assembly 3 is arranged between the fixing frame 1 and the adjusting frame 2 for elastically connecting the fixing frame 1 and the adjusting frame 2.

[0044] The housing 4 includes a second cavity 41 with an opening on one side. The housing 4 sequentially passes through the first through hole 12 and the second through hole 21 and is fixed to the adjusting frame 2. The opening of the housing 4 is close to one side of the adjusting frame 2. Preferably, the housing 4 and the adjusting frame 2 are connected by bolts. Threaded holes are provided on the side walls of the adjusting frame 2 and the housing 4, and the bolts pass through the threaded holes of the adjusting frame 2 and the housing 4 to fixedly connect the housing 4 and the adjusting frame 2.

[0045] The lens holder 5 is arranged on the housing 4 and covers the opening of the second cavity 41. The piezoelectric actuator 6 is arranged in the second cavity 41. Both ends of the piezoelectric actuator 6 are respectively connected to the housing 4 and the lens holder 5, and are used to drive the lens holder 5 to approach or move away from the housing 4, so that the lens holder 5 realizes a nanoscale linear motion in the Z-axis direction, and the Z-axis is the direction perpendicular to the plane of the lens holder 5.

[0046] The screw assembly 7 is arranged between the fixing frame 1 and the adjusting frame 2 and is used to push the adjusting frame 2 to approach or move away from the fixing frame 1. Referring to Figure 5 . The adjusting frame 2 drives the housing 4 and drives the lens holder 5 to move, thereby realizing the deflection of the lens holder 5.

[0047] The piezoelectric actuator 6 includes a cushion block 61, a pressing block 62, and a piezoelectric ceramic 63. Referring to Figure 4。The spacer block 61 and the pressing block 62 are oppositely arranged. The piezoelectric ceramic 63 is arranged in a ring shape. The piezoelectric ceramic 63 is sleeved on the outer perimeters of the spacer block 61 and the pressing block 62. Two ends of the piezoelectric ceramic 63 are respectively connected to the spacer block 61 and the pressing block 62. One sides of the spacer block 61 and the pressing block 62 away from the piezoelectric ceramic 63 are respectively connected to the lens holder 5 and the housing 4. Preferably, the pressing block 62 and the bottom of the housing 4 are connected by a first bolt 10. The spacer block 61 is of an elastic structure and is used for applying a pre-tightening force between the housing 4 and the lens holder 5. When a voltage is applied to the piezoelectric ceramic 63, the piezoelectric ceramic 63 elongates and generates a displacement, thereby pushing the spacer block 61 and pushing the lens holder 5 to move in a direction away from the housing 4. When the voltage is removed, the piezoelectric ceramic 63 restores its length, thereby driving the spacer block 61 and pushing the lens holder 5 to move in a direction close to the housing 4, that is, under the action of the piezoelectric actuator 6, the lens holder 5 realizes a nanoscale linear motion in the Z-axis direction, and thus realizes an ultra-fast step image shift.

[0048] Preferred solution of the piezoelectric actuator 6: A connecting rod 51 is provided on one side of the lens holder 5 close to the housing 4. The spacer block 61 includes a first stepped structure 611 and a fourth through hole 612, referring to Figure 7 。The pressing block 62 includes a second stepped structure 621 and a columnar body 622. The cross sections of the first stepped structure 611 and the second stepped structure 621 are in a convex shape. The first stepped structure 611 and the second stepped structure 621 are oppositely arranged. The columnar body 622 is provided with a connection hole 623 for accommodating the connecting rod 51. The connecting rod 51 passes through the fourth through hole 612 and extends into the connection hole 623 to be connected to the pressing block 62. The piezoelectric ceramic 63 is preferably in a circular ring shape and is sleeved on the first stepped structure 611 and the second stepped structure 621. Two ends of the piezoelectric ceramic 63 are respectively connected to the first stepped structure 611 and the second stepped structure 621. The present invention adopts a structure design of directly driving by the piezoelectric ceramic 63 and combining with the piezoelectric actuator 6, which has a fast response speed, accurate positioning, can realize rapid progressive phase shift, and is applicable to a dynamic optical system.

[0049] Preferred solution 1 of the screw assembly 7: The screw assembly 7 includes a screw 71, a screw sleeve 72, a first ball 73 and an adjusting block 74 disposed in the first cavity 11. The screw 71 is provided with an external thread, and the screw sleeve 72 is provided with an internal thread. The screw sleeve 72 is sleeved outside the screw 71 through a threaded connection, and the screw 71 can move along the screw sleeve 72. The side wall of the fixing frame 1 is provided with a third through hole 13, and the screw sleeve 72 is fixed in the third through hole 13. The screw 71 penetrates through the screw sleeve 72 and extends into the first cavity 11. The end of the screw 71 abuts against one side of the first ball 73. The other side of the first ball 73 abuts against the adjusting block 74. The adjusting block 74 is fixed to the bottom of the adjusting frame 2. The adjusting block 74 is provided with a chute 741 for allowing the first ball 73 to roll. Preferably, the cross section of the chute 741 is a V-shaped groove. The chute 741 forms a certain angle with the bottom plane of the adjusting frame 2. Through the inclined chute 741, the distance between the adjusting frame 2 and the fixing frame 1 can be changed. The adjusting block 74 drives the adjusting frame 2 to approach or move away from the fixing frame 1 under the push of the first ball 73. A locking nut 75 is also sleeved outside the fixing frame 1 on the screw 71. The locking nut 75 is locked on the screw 71 through an internal thread. The locking nut 75 can set the stroke of the screw 71.

[0050] Preferred solution 2: The adjusting frame 2 is set as a rectangle or a rectangle-like shape with chamfers. The number of the screw assemblies 7 is 2. Preferably, there is a long screw 71 and a short screw 71, and the two screws 71 are arranged in parallel. The adjusting blocks 74 are respectively disposed in the diagonal directions of the rectangle or rectangle-like shape of the adjusting frame 2 for pushing the adjusting frame 2 to deflect around the X axis or around the Y axis. Two adjacent sides of the adjusting frame 2 are respectively parallel to the X axis and the Y axis. The X axis and the Y axis are the plane rectangular coordinate axes, and the Z axis is perpendicular to the plane where the X axis and the Y axis are located, that is, the X axis, the Y axis and the Z axis are the space rectangular coordinate axes.

[0051] Further, a second ball 8 for supporting the adjustment frame 2 when it deflects is also provided between the adjustment frame 2 and the fixed frame 1. Corresponding grooves for accommodating the second ball 8 are provided on the adjustment frame 2 and the fixed frame 1, preferably hemispherical grooves. The second ball 8 is rotatably arranged in the two grooves. Preferably, the included angle formed by the connection lines between the centers of the second ball 8 and the centers of two adjustment blocks 74 is a right angle or approximately a right angle. Let the connection line between the second ball 8 and one adjustment block 74 be parallel to the X-axis, and the connection line between the second ball 8 and one adjustment block 74 be parallel to the Y-axis. Manually adjust the movement of the screw assembly 7 corresponding to the adjustment block 74 on the X-axis. The adjustment frame 2 is supported by the second ball 8 and the screw assembly 7 corresponding to the adjustment block 74 on the Y-axis to realize deflection around the Y-axis. Manually adjust the movement of the screw assembly 7 corresponding to the adjustment block 74 on the Y-axis. The adjustment frame 2 is supported by the second ball 8 and the screw assembly 7 corresponding to the adjustment block 74 on the X-axis to realize deflection around the X-axis. The setting of the screw assembly 7 of the present invention can realize manual control of the deflection angles of the X-axis and Y-axis of the lens holder 5. The setting of the piezoelectric actuator 6 can realize ultra-fast stepping of electric control. Combining lens adjustment with image shift stepping makes it more convenient for applications such as image shift and interference measurement. The present invention supports two methods of macro manual adjustment and micro electric drive, can be integrated with most existing optical devices, and greatly improves the overall performance of the system.

[0052] Preferred solution of the elastic connection assembly 3: The elastic connection assembly 3 includes a tension spring 31, a first pull rod 32 and a second pull rod 33, refer to Figure 8 . The two ends of the tension spring 31 are respectively connected to the first pull rod 32 and the second pull rod 33. The fixed frame 1 is provided with a blind hole or a through hole for installing the first pull rod 32. The adjustment frame 2 is provided with a blind hole or a through hole for installing the second rod. The side wall of the fixed frame 1 is also provided with a connection frame 9 for connecting with an external mechanism. The overall structure of the present invention is reasonable, compact and stable, saving space while ensuring high precision of precise positioning and stability of operation, and is suitable for optical devices requiring a compact layout.

[0053] The present invention is not limited thereto, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A macro-micro composite piezoelectric phase shifter, characterized in that: include: A fixing frame (1) provided with a first cavity (11) and a first through hole (12); An adjustment frame (2) disposed on the first cavity (11), the adjustment frame (2) being provided with a second through hole (21) corresponding to the first through hole (12); An elastic connection component (3) disposed between the fixing frame (1) and the adjusting frame (2); A shell (4), comprising a second cavity (41) with an opening on one side, the shell (4) sequentially passing through the first through hole (12) and the second through hole (21) and being fixed on the adjustment frame (2), the opening of the shell (4) being close to the adjustment frame (2); A lens holder (5), which is arranged on the housing (4) and covers the opening of the second cavity (41); a piezoelectric actuator (6) disposed in the second cavity (41), wherein two ends of the piezoelectric actuator (6) are respectively connected to the housing (4) and the lens holder (5), and is used to drive the lens holder (5) to move closer to or farther from the housing (4); A screw assembly (7) is arranged between the fixing frame (1) and the adjusting frame (2) and is used to push the adjusting frame (2) to move closer to or away from the fixing frame (1); the adjusting frame (2) drives the housing (4) and the lens holder (5) to move, so as to achieve deflection of the lens holder (5).

2. The macro-micro composite piezoelectric phase shifter according to claim 1, characterized in that: The piezoelectric actuator (6) comprises a cushion block (61), a pressure block (62) and a piezoelectric ceramic (63); the cushion block (61) and the pressure block (62) are arranged opposite to each other, the pressure block (62) is connected to the housing (4), the cushion block (61) is connected to the lens holder (5), and the piezoelectric ceramic (63) is annular and sleeved on the outer circumference of the cushion block (61) and the pressure block (62); the cushion block (61) is an elastic structure and is used to apply a pre-tightening force between the housing (4) and the lens holder (5).

3. The macro-micro composite piezoelectric phase shifter according to claim 2, characterized in that: A connecting rod (51) is provided on a side of the lens holder (5) close to the shell (4); the cushion block (61) comprises a first step structure (611) and a fourth through hole (612); the pressing block (62) comprises a second step structure (621) and a columnar body (622); the columnar body (622) is provided with a connecting hole (623) for accommodating the connecting rod (51); the connecting rod (51) passes through the fourth through hole (612) and extends into the connecting hole (623), and is connected to the pressing block (62); and the piezoelectric ceramic (63) is sleeved on the first step structure (611) and the second step structure (621).

4. The macro-micro composite piezoelectric phase shifter according to claim 1, characterized in that: The screw assembly (7) comprises a screw (71), a screw sleeve (72) threadedly connected to the screw (71), and a first ball (73) and an adjustment block (74) arranged in the first cavity (11); The side wall of the fixing frame (1) is provided with a third through hole (13), and the screw sleeve (72) is arranged in the third through hole (13); the screw (71) passes through the screw sleeve (72) and extends into the first cavity (11), the end of the screw (71) abuts against one side of the first ball (73), and the other side of the first ball (73) abuts against the adjustment block (74); the adjustment block (74) is arranged at the bottom of the adjustment frame (2), and the adjustment block (74) is provided with a sliding groove (741) for allowing the first ball (73) to roll, and the adjustment block (74) drives the adjustment frame (2) to approach or move away from the fixing frame (1) under the push of the first ball (73).

5. The macro-micro composite piezoelectric phase shifter according to claim 4, characterized in that: The adjustment frame (2) is configured as a rectangle or a quasi-rectangle with chamfered corners, the number of the screw rod assemblies (7) is 2, and the two adjustment blocks (74) are respectively arranged in the diagonal direction of the rectangle or the quasi-rectangle, and are used to push the adjustment frame (2) to deflect around the X-axis or around the Y-axis; Two adjacent sides of the adjustment frame (2) are respectively parallel to the X-axis and the Y-axis, and the X-axis and the Y-axis are plane rectangular coordinate axes.

6. The macro-micro composite piezoelectric phase shifter according to claim 5, characterized in that: A second ball bearing (8) for supporting is further provided between the adjustment frame (2) and the fixing frame (1), and grooves for accommodating the second ball bearing (8) are correspondingly provided on the adjustment frame (2) and the fixing frame (1).

7. The macro-micro composite piezoelectric phase shifter according to claim 6, characterized in that: The angles formed by the lines connecting the centers of the second rolling ball (8) and the centers of the two adjustment blocks (74) are right angles or approximately right angles.

8. The macro-micro composite piezoelectric phase shifter according to claim 4, characterized in that: The slide groove (741) and the plane of the bottom of the adjustment frame (2) form a certain angle.

9. The macro-micro composite piezoelectric phase shifter according to claim 1, characterized in that: The elastic connection assembly (3) comprises a tension spring (31), a first tension rod (32) and a second tension rod (33); two ends of the tension spring (31) are respectively connected to the first tension rod (32) and the second tension rod (33); The fixing frame (1) is provided with a blind hole or a through hole for mounting the first pull rod (32), and the adjusting frame (2) is provided with a blind hole or a through hole for mounting the second rod (33).

10. The macro-micro composite piezoelectric phase shifter according to claim 1, characterized in that: The side wall of the fixing frame (1) is also provided with a connecting frame (9) for connecting to an external mechanism.

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