CN117930494A

CN117930494A - Micro mirror device

Info

Publication number: CN117930494A
Application number: CN202211253477.1A
Authority: CN
Inventors: 虞涛
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-10-13
Filing date: 2022-10-13
Publication date: 2024-04-26

Abstract

The invention discloses a micro-mirror device, which comprises a reflecting mirror, a support column, a driving component and a supporting structure, wherein the upper surface of the reflecting mirror is a reflecting surface, the lower surface of the reflecting mirror is connected with the support column, the driving components connected to the supporting structure are respectively arranged on two opposite sides of the circumference of the support column, the driving component comprises a piezoelectric driving element and an actuating mechanism, the support column is supported by the actuating mechanism, and the actuating mechanism is driven by the stretching deformation of the piezoelectric driving element along the transverse direction to generate height variation so as to drive the reflecting mirror to deflect. The invention adopts a piezoelectric driving mode, realizes vertical height lifting by the transverse telescopic action, has small driving loss, is easy to manufacture, effectively reduces the control difficulty, and has convenient control and good stability.

Description

Micro mirror device

Technical Field

The present invention relates to the field of microelectromechanical systems, and in particular, to a micromirror device.

Background

A digital micromirror device (Digtial Micromirror Devices, DMD), which is a micro-electro-mechanical-MECHANICAL SYSTEM (MEMS) system with electronic input and optical output, is a core device of a DLP projection system, and is generally composed of hundreds of thousands to millions of micro-mirrors distributed in a matrix, each micro-mirror corresponds to a pixel, and the imaging pattern and its characteristics are determined by controlling the rotation and time domain response (determining the reflection angle and dead time of light) of the micro-mirror, which is a novel, all-digital device, and the micro-mirror array and CMOS SRAM are integrated on the same chip by using the MEMS technology. Each micromirror unit in the digital micromirror device is an independent unit, and can be turned over by different angles independently to reflect light to the illumination light path or the absorption light path, the main structure of the micromirror unit of the existing digital micromirror device comprises four layers, the first layer is a micromirror in a floating state, made of aluminum alloy, the second layer is a torsion beam-hinge connecting the micromirror, and the addressing electrode of the micromirror, the third layer is a metal layer, including the addressing electrode of the torsion beam, the bias/reset electrode, and the landing platform of the micromirror (limiting mirror deflection by ±12° or ±10°), the fourth layer is a static memory (RAM) using a standard CMOS process of a large scale integrated circuit, the micromirror is connected to the torsion beam, and the torsion beam is suspended on two hinge support posts by hinges, which are connected to the bias/reset electrode, which provides a bias voltage for each micromirror unit, there are two conductive channels for each micromirror unit, and the addressing electrode of the arm beam and the static memory of the digital micromirror are connected to the bottom layer of the torsion beam. In operation of the digital micromirror device, deflection (positive and negative) of the micromirror is individually controlled by changing binary states of the underlying CMOS control circuit and the lens reset signal, specifically, applying a bias voltage, wherein +5v (digital 1) is applied to one of the addressing electrodes and the other addressing electrode is grounded (digital 0), so that an electrostatic field is formed between the micromirror and the addressing electrode of the micromirror, the torsion beam and the addressing electrode of the torsion beam, thereby generating an electrostatic moment, causing the micromirror to rotate about the torsion beam until contacting the landing platform, and the micromirror unit will be locked in that position until the reset signal occurs. The existing digital micromirror device adopts an electrostatic control structure, and has low driving efficiency, high control difficulty and high complexity.

Disclosure of Invention

The invention aims to solve the technical problems and the technical task provided by the invention are to improve the prior art, provide a micro-mirror device and solve the problems of high control difficulty and high complexity of an electrostatic control structure adopted by a digital micro-mirror device in the prior art.

In order to solve the technical problems, the technical scheme of the invention is as follows:

The utility model provides a micromirror device, includes speculum, pillar, drive assembly and bearing structure, the upper surface of speculum is the reflecting surface, the lower surface of speculum is connected with the pillar on the two opposite sides in pillar circumference are provided with respectively and connect on bearing structure the drive assembly, the drive assembly includes piezoelectricity actuating element and actuating mechanism, the pillar by actuating mechanism supports, actuating mechanism by the piezoelectricity actuating element produces along horizontal flexible deformation drive in order to produce the high variation drive of producing the speculum deflection. The micro mirror device adopts a piezoelectric driving mode, has a simple structure and good compactness, and because the two sides of the support column are respectively connected with the actuating mechanism support of the driving assembly, the actuating mechanism on one side of the support column can drive the support column to deflect and incline, namely, the deflection and incline of the driving mirror are realized, the driving loss is small, the manufacturing is easy, the control difficulty is effectively reduced, the transverse stretching action can be realized by applying voltage to the piezoelectric driving element, the deflection of the mirror is realized, the control is convenient, the stability is good, a single micro mirror device only needs a simple circuit to drive, a complex driving circuit is not needed, the complexity in the development of a subsequent digital micro mirror device is simplified, and the cost is reduced.

Further, the driving assembly comprises an actuating layer, the actuating layer is an arched layer with high middle parts and low two ends, the middle part of the actuating layer is in transmission connection with the support column, and the distance between the two ends of the actuating layer is adjusted by the piezoelectric driving element along transverse telescopic deformation so that the height of the middle part of the actuating layer is changed to drive the reflecting mirror to deflect. The distance between two ends of the actuating layer is changed through the transverse telescopic deformation of the piezoelectric driving element, and the actuating layer is extruded and pulled, so that the actuating layer is deformed, the middle part of the actuating layer is changed in height, namely, the transverse telescopic movement is changed into vertical height lifting through the cooperation of the piezoelectric driving element and the actuating layer.

Furthermore, the two ends of the actuating layer are connected to the piezoelectric driving element at intervals along the transverse expansion direction of the piezoelectric driving element, so that the structure is simple and the implementation is easy.

Further, in the state that the voltage is not applied to the piezoelectric driving element, the included angle between the actuating layer and the transverse stretching direction of the piezoelectric driving element is 0-30 degrees, the stretching action of a small length in the transverse direction can realize the lifting of a large size in the vertical direction, namely, the piezoelectric driving element can generate enough height change in the middle of the actuating layer to enable the deflection angle of the reflecting mirror to meet the requirement only by carrying out small stretching deformation, and the vertical lifting distance can be 11.5-10 times of the transverse stretching distance when the included angle is 0-30 degrees, so that the driving voltage of the piezoelectric driving element can be reduced, the power consumption is reduced, the size of a device is reduced, and the structural compactness is improved.

Furthermore, the actuating layer is formed by connecting the first flat plate layer and the second flat plate layer at an included angle, so that the middle part of the actuating layer is high, the two ends of the actuating layer are low, the actuating layer is simple in structure, easy to implement and manufacture, and good in structural stability.

Further, the piezoelectric driving element comprises a first electrode layer, a piezoelectric material layer and a second electrode layer which are sequentially stacked, the structure is simple, the piezoelectric material layer can be deformed in a stretching mode along the transverse direction by applying voltage to the first electrode layer and the second electrode layer, the stretching, shortening and deformation of the piezoelectric material layer can be controlled by regulating voltage polarity and voltage, and finally the deflection inclination direction and angle of the reflecting mirror can be controlled.

Further, the supporting structure comprises a substrate layer, the substrate layer is arranged below the bottom surface of the piezoelectric driving element, a supporting layer is arranged between the bottom surface of the piezoelectric driving element and the basic layer, the supporting layer is supported in the middle of the piezoelectric driving element so that the piezoelectric driving element is in a cantilever state from the middle of the piezoelectric driving element to two ends in the stretching direction, the structure is simple, the piezoelectric driving element can be stably supported, the piezoelectric driving element is only partially connected with the supporting layer, the piezoelectric driving element can be fully and effectively stretched and deformed when voltage is applied, and the stretching and deformation of the piezoelectric driving element is prevented from being interfered.

Further, the supporting layer is a conducting layer electrically connected with the first electrode layer on the bottom surface of the piezoelectric driving element, so that voltage is conveniently applied to the piezoelectric driving element to drive the piezoelectric driving element to stretch and deform, and the design of a driving circuit is facilitated.

Furthermore, the supporting layer and the first electrode layer are integrated into a whole, so that the structure is simple, and the implementation and the manufacture are easy.

Further, still include the torsion arm roof beam, the torsion arm roof beam supports and connects on bearing structure, the pillar is connected on the torsion arm roof beam, actuating mechanism is connected with the torsion arm roof beam and is driven with the torsion of drive torsion arm roof beam the speculum deflects, and piezoelectric drive element carries out vertical lift along the middle part of the flexible area action layer of horizontal, and the middle part of action layer is driven torsion arm roof beam again, finally realizes the deflection of speculum, and the speculum passes through the pillar and supports on the torsion arm roof beam, can better ensure the stability of speculum.

Further, the drive assembly is located directly below the lower surface of the mirror and the drive assembly does not extend beyond the projected area when the mirror is undeflected. The structure is compact, the occupied space is small, the size of the whole micro-mirror device is equivalent to that of the reflecting mirror, the integration level can be improved, high resolution is realized on the DMD chip with small size, the details of the image are clearly and accurately displayed, and the distortion generated by the image in the imaging process is reduced.

Compared with the prior art, the invention has the advantages that:

the micro-mirror device adopts a piezoelectric driving mode, has a simple structure and good compactness, the transverse telescopic action of the piezoelectric driving element realizes vertical height lifting so as to drive the reflecting mirror to deflect and incline, the driving loss is small, the manufacturing is easy, the control difficulty is effectively reduced, the control is convenient, the stability is good, a single micro-mirror device only needs a simple circuit for driving, a complex driving circuit is not needed, the complexity in the development of subsequent digital micro-mirror devices is simplified, and the cost is reduced.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a micromirror device according to a first embodiment of the invention;

FIG. 2 is a schematic side view of a drive assembly;

FIG. 3 is a schematic diagram of the operating principle of the drive assembly;

FIG. 4 is a schematic side view of another embodiment of a drive assembly;

FIG. 5 is a schematic diagram of a third side view of a drive assembly;

FIG. 6 is a schematic diagram of the overall structure of a micromirror device according to a second embodiment of the invention;

fig. 7 is a schematic diagram of the overall structure of a micromirror device according to a third embodiment of the invention.

In the figure:

Mirror 1, support 11, drive unit 2, piezoelectric drive element 21, first electrode layer 211, piezoelectric material layer 212, second electrode layer 213, actuation layer 22, first plate layer 221, second plate layer 222, support structure 3, substrate layer 31, support layer 32, support post 33, and torsion beam 4.

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The embodiment of the invention discloses a micromirror device which has the advantages of simple structure, good compactness, easy manufacture, convenient and simple control and high driving efficiency.

Example 1

As shown in fig. 1 and 2, a micromirror device mainly comprises a reflecting mirror 1, a support 11, a driving component 2 and a supporting structure 3, wherein the upper surface of the reflecting mirror 1 is a reflecting surface, the lower surface of the reflecting mirror 1 is connected with the support 11, the driving components 2 are respectively arranged at two opposite sides of the periphery of the support 11, the driving component 2 comprises a piezoelectric driving element 21 which is elastically deformed along the transverse direction when voltage is applied, the piezoelectric driving element 21 is supported and connected with the supporting structure 3, the top of the piezoelectric driving element 21 is provided with an actuating layer 22, the actuating layer 22 is an arch-shaped layer with high middle part and low ends, the two ends of the actuating layer 22 are connected with the piezoelectric driving element 21 at intervals along the extending and contracting direction of the piezoelectric driving element 21, a gap layer is formed between the actuating layer 22 and the top surface of the piezoelectric driving element 21, the gap height of the gap layer is reduced from the middle part to the two ends in the extending and contracting direction of the piezoelectric driving element 21, the support 11 is supported and connected with the middle part of the actuating layer 22, the piezoelectric driving component 2 is supported and connected with the middle part of the actuating layer 22 along the opposite sides, the two symmetrical driving component 2 is arranged at the opposite sides of the periphery of the support 11, the piezoelectric driving element 21 is elastically deformed along the extending and contracting direction along the two ends of the extending and contracting direction of the piezoelectric driving element 21, the piezoelectric element 21 is further connected with the two ends of the piezoelectric driving element 21, and the piezoelectric element 21 is deformed along the two ends are arranged along the extending and contracting direction of the middle layer 11 and the extending and contracting along the direction of the middle layer 21, specifically, when a voltage is applied to the piezoelectric driving element 21 of one of the driving units 2 to cause it to shorten, the distance between the two ends of the actuating layer 22 is reduced, that is, the actuating layer 22 is pressed toward the middle thereof, so that the height of the middle of the actuating layer 22 is increased, and since one side of the support 11 is connected to the middle of the actuating layer 22, the side of the support 11 is raised, thereby causing the support 11 to deflect and tilt, that is, the mirror 1 is driven to deflect and tilt, the micromirror device according to the present embodiment has a microstructure of micrometer scale, the support 11 and the middle of the actuating layer 22 can be directly connected without being connected by a hinge mechanism, and when the height of the middle of the actuating layer 22 on one side of the support 11 is increased and the height of the middle of the actuating layer 22 on the other side of the support 11 is unchanged, the connection between the support 11 and the middle of the actuating layer 22 can deform to a certain extent to achieve the deflection and tilt of the support 11. When the micro mirror device in this embodiment is disposed in the light path, the mirror 1 is driven to deflect by a piezoelectric driving manner, so that light is reflected to the required light path according to requirements, and only a simple circuit is required for driving, so that the micro mirror device has a simple and compact structure, small driving efficiency and convenient control.

The piezoelectric driving element 21 is mechanically deformed by an inverse piezoelectric effect, that is, when a voltage is applied to the piezoelectric material in the polarization direction, the piezoelectric material deforms, and after the voltage is removed, the deformation of the piezoelectric material disappears. Specifically, as shown in fig. 2, the piezoelectric driving element 21 is a composite layer structure, which includes a first electrode layer 211, a piezoelectric material layer 212 and a second electrode layer 213 that are sequentially stacked from bottom to top, and three layers of materials are stacked and connected together by a deposition processing manner, where the first electrode layer 211 and the second electrode layer 213 are made of conductive materials, specifically, materials such as platinum and molybdenum, and the piezoelectric material layer 212 is made of materials such as barium titanate BT, lead zirconate titanate PZT, modified lead zirconate titanate, lead metaniobate, lead barium lithium niobate PBLN, modified lead titanate PT, lead magnesium niobate PMN, aluminum nitride AlN, scandium-doped aluminum nitride ScAlN, and the like, which is not particularly limited. Specifically, when the first electrode layer 211 is grounded and the second electrode layer 213 is connected to a positive voltage, the piezoelectric material layer 212 deforms in the lateral direction, when the first electrode layer 211 is grounded and the second electrode layer 213 is connected to a negative voltage, the piezoelectric material layer 212 deforms in the lateral direction, the mechanical deformation amount and the expansion direction of the piezoelectric material layer 212 are related to the material characteristics of the piezoelectric material layer 212 and the magnitude and polarity of the voltage applied to the piezoelectric driving element 21, the magnitude of the deflection angle of the mirror 1 is related to the magnitude of the voltage applied to the piezoelectric driving element 21, and the larger the applied voltage is, the larger the shortening deformation amount of the piezoelectric driving element 21 is, the larger the lifting amount in the middle of the actuation layer 22 is, so that the deflection angle of the mirror 1 is larger, that is, the deflection angle of the mirror 1 is controlled by controlling the magnitude of the voltage applied to the piezoelectric driving element 21. In this embodiment, the piezoelectric material layer 212 is mainly used to shorten and deform to drive the middle part of the actuating layer 22 to rise so as to raise one side of the mirror 1 for deflection, and when the opposite deflection is needed, a voltage is applied to the piezoelectric driving element 21 of the other side driving component 2 so as to raise the other side of the mirror 1 for deflection.

In this embodiment, when it is required to drive the mirror 1 to deflect in the forward direction, the piezoelectric driving element 21 of the left driving unit 2 in fig. 1 is in a state where no voltage is applied, and only the piezoelectric driving element 21 of the right driving unit 2 is applied with a voltage so that the height of the middle part of the left actuating layer 22 is not changed, and only the height of the middle part of the right actuating layer 22 is changed, and the voltage is applied so that the piezoelectric driving element 21 on the left is compressed and shortened, and the height of the middle part of the right actuating layer 22 is increased so that the right side of the mirror 1 is increased to realize deflection tilting; when the mirror 1 is required to be reversely deflected, reverse control is performed to drive the mirror 1 to be reversely deflected, namely, an upper voltage is applied to the piezoelectric driving element 21 on the left side, and the voltage applied to the piezoelectric driving element 21 on the right side is released, so that the height of the middle part of the actuating layer 22 on the left side becomes high, and the height of the middle part of the actuating layer 22 on the right side is restored to original, so that the left side of the mirror 1 becomes high to realize reverse deflection tilting; no voltage is applied to the piezoelectric driving elements 21 of the driving assemblies 2 on the left and right sides, the heights of the middle portions of the actuating layers 22 on the both sides are at the initial heights, and the mirror 1 is in the non-deflected intermediate state. The driving control mode can be adopted to realize the switching of the reflecting mirror 1 between three states of positive deflection angle, 0 degree and negative deflection angle, the deflection angle of the reflecting mirror 1 is related to the voltage applied to the piezoelectric driving element 21, the larger the applied voltage is, the larger the deformation of the piezoelectric driving element 21 is, the larger the height change of the middle part of the actuating layer 22 is, and the larger the deflection angle of the reflecting mirror 1 is, so that the deflection angle of the reflecting mirror 1 is controlled by controlling the voltage value applied to the piezoelectric driving element 21. Naturally, the driving assemblies 2 on both sides may be driven and controlled simultaneously, that is, the piezoelectric driving elements 21 on one side apply a forward voltage, and the piezoelectric driving elements 21 on the other side apply a reverse voltage, so that one of the piezoelectric driving elements 21 on both sides is elongated and deformed, the other is shortened and deformed, and the middle of the actuating layer 22 on both sides is lowered and raised, so that the deflection and inclination of the driving mirror 1 can be realized.

In the embodiment, the height of the middle part of the actuating layer 22 is raised and lowered by the stretching action of the piezoelectric driving element 21 in the transverse direction so as to drive the reflecting mirror 1 to deflect and incline, in order to ensure that the deflection angle of the reflecting mirror 1 meets the requirement, the height variation of the middle part of the actuating layer 22 needs to meet the requirement, the embodiment adopts a structure of combining the piezoelectric driving element 21 and the actuating layer 22, can realize that the middle part of the actuating layer 22 generates enough height variation by the small stretching deformation in the transverse direction, specifically, the actuating layer 22 is deposited by adopting a metal material, can also be amorphous silicon, a nonmetallic film material and the like, ensures that the actuating layer has rigidity so as to play a stable supporting role and simultaneously ensures that the actuating layer can deform so as to adjust the height, the layer thickness of the actuating layer 22 is 0.05-1 mu m, the thickness of the actuating layer 22 is set according to the whole size of the micro mirror device, in the micro mirror device according to this embodiment, when the outside diameter of the micro mirror device is 5-20 μm, the span of the actuating layer 22 is smaller than 5-10 μm, the thickness of the actuating layer 22 is preferably 0.05-0.2 μm, the angle between the actuating layer 22 and the transverse expansion direction of the piezoelectric driving element 21 is 0-30 ° in the state that no voltage is applied to the piezoelectric driving element 21, the small amount of the piezoelectric driving element 21 in the transverse direction can generate a large variation amount in the height of the middle part of the actuating layer 22, the principle that the height of the middle part of the actuating layer 22 is changed by the transverse expansion deformation driving of the piezoelectric driving element 21 in the transverse direction is shown in fig. 3, i is the variation amount in the transverse direction, i is the length of the connecting line from the middle part of the actuating layer 22 to the end part of the actuating layer 22, a is the angle between the connecting line from the middle part of the actuating layer 22 to the end part of the actuating layer 22 and the transverse direction when no voltage is applied to the piezoelectric driving element 21, α' is the angle between the line from the middle of the actuating layer 22 to the end of the actuating layer 22 and the lateral direction after the voltage is applied to the piezoelectric driving element 21, and o is the height variation of the middle of the actuating layer 22, and the formula can be obtained from the figure:

It can be deduced that:

the method further comprises the following steps:

Assuming that α is 5 ° and that iota is set to 10 μm, for example, the piezoelectric driving element 21 is shortened by 0.06 μm as a whole, the unilateral shortening fluctuation amount i=0.03 μm, as calculated by the above formula, is obtained, the height of the middle part of the actuating layer 22 is raised by 0.293 μm, and the height fluctuation amount of the middle part of the actuating layer 22 is about 10 times the deformation amount of the piezoelectric driving element 21 in the lateral direction, that is, a sufficiently large height fluctuation amount is achieved in the middle part of the actuating layer 22 due to the small expansion and contraction deformation amount of the piezoelectric driving element 21 in the lateral direction, so that the deflection tilt angle of the mirror 1 reaches the requirement, the deformation amount of the piezoelectric driving element 21 is small, the voltage to be applied is small, the power consumption can be reduced, and the structural compactness can be advantageously improved.

In this embodiment, the actuating layer 22 is an arched layer with a middle part with two ends being high and low formed by connecting the first plate layer 221 and the second plate layer 222 at an included angle, which is simple in structure, good in stability and easy to implement, and the length of the first plate layer 221 and the second plate layer 222 is the length iota of the connecting line from the middle part of the actuating layer 22 to the end part of the actuating layer 22 in the formula, so that the variation of the middle height of the actuating layer 22 can be conveniently and accurately controlled, and the deflection and inclination angle of the reflecting mirror 1 can be accurately controlled. The actuating layer 22 may have other shapes and structures, and as shown in fig. 4 and 5, the actuating layer 22 may have an arc-shaped plate layer, a trapezoid-shaped plate layer, or the like.

The method for manufacturing the actuating layer 22 includes depositing a photoresist layer on the top surface of the piezoelectric driving element 21, etching the top surface of the photoresist layer to form the outline of the lower surface of the actuating layer 22 by gray scale lithography, depositing the actuating layer 22 on the top surface of the photoresist layer, depositing two ends of the actuating layer 22 connected to the piezoelectric material layer 212, etching the photoresist between the actuating layer 22 and the piezoelectric driving element 21 completely, so that a gap layer is formed between the actuating layer 22 and the piezoelectric driving element 21, and the telescopic deformation of the piezoelectric driving element 21 can drive the actuating layer 22 to deform to adjust the height of the middle part of the actuating layer 22, and depositing the generating support 11 and the reflecting mirror 1 in the middle part of the actuating layer 22.

The piezoelectric driving element 21 is supported and connected to the supporting structure 3, so that the piezoelectric driving element 21 can be stably supported and further the mirror 1 can be stably supported, and meanwhile, the piezoelectric driving element 21 needs to be ensured to be free from being deformed without interference, for example, one end of the piezoelectric driving element 21 in the telescopic direction is supported and connected to the supporting structure 3, so that the piezoelectric driving element 21 is in a cantilever state as a whole, and the piezoelectric driving element 21 can be stably supported and deformed without interference and can also stably support the mirror 1. Specifically, in this embodiment, the support structure 3 includes a substrate layer 31, the substrate layer 31 is located below the bottom surface of the piezoelectric driving element 21, a support layer 32 is disposed between the bottom surface of the piezoelectric driving element 21 and the base layer, the support layer 32 is smaller than the bottom surface area of the piezoelectric driving element 21, and the support layer 32 is only supported in the middle of the piezoelectric driving element 21, so that the piezoelectric driving element 21 is in a cantilever state from the middle to two ends in the stretching direction, and in this way, the piezoelectric driving element 21 can be stably supported, and meanwhile, the stretching deformation of the piezoelectric driving element 21 is not hindered, so that the piezoelectric driving element 21 can be freely stretched and deformed to drive the deformation of the actuating layer 22 to drive the mirror 1 to deflect and tilt. The substrate layer 31 may include a base layer, an insulating layer and a top layer, which are sequentially deposited from bottom to top, the base layer is a silicon layer, the insulating layer may be made of insulating materials such as silicon dioxide, silicon nitride, and aluminum oxide, the top layer may be a silicon layer, the supporting layer 32 is a conductive layer electrically connected to the first electrode layer 211 on the bottom surface of the piezoelectric driving element 21, the supporting layer 32 is formed on the substrate layer 31 in a deposition manner, and the supporting layer 32 and the first electrode layer 211 may be integrated into a whole, that is, the middle part of the first electrode layer 211 has a structure protruding downward to form the supporting layer 32, and the thickness of the supporting layer 32 is 0.05-0.5 μm, so that the piezoelectric driving element 21 can freely perform expansion deformation, and simultaneously, the overall height of the micromirror device is reduced, and the structural compactness is improved.

The driving component 2 is located right below the lower surface of the reflector 1, and the driving component 2 does not exceed the projection area range of the reflector 1 when not deflected, specifically, the pillar 11 is connected at the center of the lower surface of the reflector 1, the cross section size of the pillar 11 is smaller than the surface size of the reflector 1, the reflector 1 is connected at the top side of the pillar 11, the middle part of the actuating layer 22 of the driving component 2 is connected at the bottom side of the pillar 11, the size of the piezoelectric driving component 21 in the transverse direction needs to be smaller than the outer diameter size of the reflector 1 so that the driving component 2 does not exceed the projection area range of the reflector 1 when not deflected, thus being beneficial to improving the integration level, the digital micro-mirror device for DLP projection system comprises hundreds of thousands to millions of micro-mirror devices, each micro-mirror device corresponds to one pixel, the smaller the size of the micromirror device, the higher the resolution can be realized on a small-sized chip, which is advantageous for reducing the volume of the projection system and satisfying the miniaturization development, specifically, the surface of the mirror 1 may be rectangular, specifically, may be square, or rectangular, and of course, the mirror 1 may also take other shapes, such as a circle, an ellipse, etc., where the mirror 1 is illustrated as a square, as shown in fig. 1, the normal direction of the surface of the mirror 1 when the deflection is not performed is defined as the Z-axis direction, the surface direction of the mirror 1 when the deflection is not performed is defined as the X-Y plane direction, more specifically, one side of the mirror 1 in the square is the X-axis direction, the other side of the mirror 1 in the square is the Y-axis direction, the driving components 2 are symmetrically disposed on both sides of the support post 11, the symmetry axis between the two side driving units 2 is parallel to the Y-axis direction, and the direction of the expansion and contraction deformation of the piezoelectric driving element 21 of the driving unit 2 is along the Y-axis direction, and when a voltage is applied to the piezoelectric driving element 21 on one side, the middle part of the actuating layer 22 on the side is lifted to lift the side of the mirror 1, so that the deflection axis of the mirror 1 is parallel to the Y-axis direction, which can also be expressed as that the deflection axis of the mirror 1 is parallel to the symmetry axis between the two side driving units 2, and the two side driving units 2 can also be arranged to be distributed on two sides of the strut 11 with the diagonal of the mirror 1 as the symmetry axis, so that the expansion and contraction deformation direction of the piezoelectric driving element 21 of the driving unit 2 is parallel to the diagonal of the mirror 1, and the deflection axis of the mirror 1 is also along the diagonal of the mirror 1.

Example two

As shown in fig. 6, the difference from the first embodiment is that the device further comprises a torsion arm beam 4, the torsion arm beam 4 is supported and connected to the supporting structure 3, the support column 11 is connected to the torsion arm beam 4, the middle part of the actuating layer 22 is connected to the torsion arm beam 4 to drive the torsion arm beam 4 to twist so as to drive the reflector 1 to deflect, specifically, two ends of the torsion arm beam 4 are respectively supported and connected to the substrate layer 31 through support columns so as to form a suspended cross beam, the bottom of the support column 11 is connected to the middle part of the torsion arm beam 4, the middle part of the actuating layer 22 is connected to the torsion arm beam 4 through a support rod extending in the transverse direction, when a voltage is applied to the piezoelectric driving element 21, the piezoelectric driving element 21 deforms transversely so as to drive the actuating layer 22 to change the height of the middle part of the actuating layer 22, and the middle part of the actuating layer 22 drives the torsion arm beam 4 to twist so as to deflect the support column 11, that is to drive the reflector 1 to deflect and tilt.

Example III

As shown in fig. 7, the difference from the first embodiment is that one end of the actuating layer 22 is fixed, the other end is connected to the piezoelectric driving element 21, the piezoelectric driving element 21 can also adjust and change the distance between two ends of the actuating layer 22 along the transverse expansion and contraction deformation so as to deform the actuating layer 22, and further adjust the height of the middle part of the actuating layer 22, and finally realize the deflection tilting of the driving mirror 1, specifically, a support column 33 with the same height as the piezoelectric driving element 21 can be deposited on the substrate layer 31 to support and fix one end of the actuating layer 22, and the other end of the actuating layer 22 is connected to the piezoelectric driving element 21.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that the above-mentioned preferred embodiment should not be construed as limiting the invention, and the scope of the invention should be defined by the appended claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.

Claims

1. The utility model provides a micromirror device, its characterized in that includes speculum (1), pillar (11), drive assembly (2) and bearing structure (3), the upper surface of speculum (1) is the reflecting surface, the lower surface of speculum (1) is connected with pillar (11) on the ascending opposite sides of pillar (11) circumference are provided with respectively connect on bearing structure (3) drive assembly (2), drive assembly (2) include piezoelectricity actuating element (21) and actuating mechanism, pillar (11) are by actuating mechanism supports, actuating mechanism is by piezoelectricity actuating element (21) produce along the flexible deformation drive of transverse in order to produce the high variation drive speculum (1) deflection.

2. Micromirror device according to claim 1, characterized in that the driving component (2) comprises an actuating layer (22), the actuating layer (22) is an arched layer with a middle part higher and lower ends, the middle part of the actuating layer (22) is in transmission connection with the support column (11), and the distance between the two ends of the actuating layer (22) is adjusted by the piezoelectric driving element (21) along the transverse telescopic deformation, so that the height of the middle part of the actuating layer (22) is changed to drive the reflecting mirror (1) to deflect.

3. Micromirror device according to claim 2, characterized in that the two ends of the actuation layer (22) are connected to the piezoelectric driving element (21) at intervals along the transversal telescopic direction of the piezoelectric driving element (21).

4. Micromirror device according to claim 2, characterized in that the angle between the actuating layer (22) and the lateral direction of the piezo-electric drive element (21) is 0-30 ° in the state where no voltage is applied to the piezo-electric drive element (21).

5. The micromirror device according to claim 2, wherein the actuating layer (22) comprises a middle high arch layer and two low arch layers formed by the first plate layer (221) and the second plate layer (222) joined at an angle.

6. The micromirror device according to claim 1, wherein the piezoelectric driving element (21) comprises a first electrode layer (211), a piezoelectric material layer (212) and a second electrode layer (213) stacked in this order.

7. Micromirror device according to claim 1, characterized in that the support structure (3) comprises a substrate layer (31), the substrate layer (31) being located below the bottom surface of the piezoelectric driving element (21), a support layer (32) being arranged between the bottom surface of the piezoelectric driving element (21) and the base layer (), the support layer (32) being supported in the middle of the piezoelectric driving element (21) such that the piezoelectric driving element (21) is cantilevered from its middle towards both ends in the telescoping direction.

8. Micromirror device according to claim 7, characterized in that the support layer (32) is an electrically conductive layer in electrical communication with the first electrode layer (211) of the bottom surface of the piezoelectric driving element (21).

9. Micromirror device according to claim 8, characterized in that the support layer (32) is integrated with the first electrode layer (211).

10. Micromirror device according to claim 1, characterized in that it further comprises a torsion beam (4), the torsion beam (4) being supported and connected to the support structure (3), the support (11) being connected to the torsion beam (4), the actuation mechanism being connected to the torsion beam (4) for driving the torsion beam (4) to twist for driving the deflection of the mirror (1).

11. Micromirror device according to claim 1, characterized in that the driving component (2) is located directly below the lower surface of the mirror (1) and the driving component (2) does not exceed the projection area of the mirror (1) when it is undeflected.