KR20060124079A - Mems scanning micromirror and dual-axis electromagnetic mems scanning micromirror device - Google Patents

Abstract

A MEMS scanning micromirror and a dual-axis electromagnetic MEMS scanning micromirror device are provided to increase the scanning speed and range by improving structural safety and optical property of the scanning micromirror. A dual-axis electromagnetic MEMS(Micro Electro Mechanical System) scanning micromirror device includes a circular micromirror(301), a pair of inner elastic bending structures, a gimbal(302), and a pair of outer elastic bending structures(304). The circular micromirror includes a mirror film having a reflective surface, and a frame structure supporting the micromirror film. The inner and outer inner elastic bending structures support the micromirror and the gimbal. The inner elastic bending structures are arranged to be symmetrical with each other on an X-X' axis passing through the center of the micromirror. The micromirror rotates around the X-X' axis.

Description

Scanning micromirror and electromagnetic force-driven biaxial scanning micromirror device {MEMS scanning micromirror and Dual-axis electromagnetic MEMS scanning micromirror device}

1 is a view schematically showing an example of a scanning apparatus using a polygon mirror according to the prior art.

2A to 2B are schematic diagrams illustrating a scanning principle of a scanning apparatus using a micromirror according to the prior art.

3A to 3B are perspective views showing one embodiment of the scanning micromirror of the present invention.

4A-4B are perspective views of one embodiment of the micromirror portion of the scanning micromirror of the present invention.

5A-5C are perspective views of other embodiments of the micromirror portion of the scanning micromirror of the present invention.

6 is a plan view from above of an embodiment of an electromagnetic force driven scanning micromirror device of the present invention.

7A to 7B are perspective views showing another embodiment of the electromagnetic force driven scanning micromirror device of the present invention.

FIG. 8 is a view of the embodiment of the electromagnetically driven scanning micromirror device of the present invention with the conductors in a plan view from above.

9A to 9B are perspective views showing one embodiment of a magnetic field supply unit of the electromagnetic force driven scanning micromirror device of the present invention.

10 is a cross-sectional view taken along line AA ′ of FIG. 8 of an embodiment of the electromagnetic force driven scanning micromirror device of the present invention.

FIG. 11 is a view from above of an embodiment of the electromagnetically driven scanning micromirror device of the present invention, with a portion of the lead shown together.

12 is a plan view, as seen from above, of an embodiment of the electromagnetically driven scanning micromirror device of the present invention, with a portion of the lead shown together.

{Description of major symbols in the drawing}

301,601,701,801: Micromirror

302,602,702,802: gimbal

303,603,703,803: Internal Elastic Flexural Structures

304,604,804: External Elastic Flexural Structures

401,501: Mirror Plate

402: frame structure

403,503: torsion beam

504: Diamond Array Frame Structure

505: etching hole

506: diamond array frame structure thinner toward the end

711,811: first mirror drive coil

712,812: second mirror drive coil

813: First Gamble Drive Coil

814: second gamble drive coil

901 support

902: internal magnet

903: External magnet

The present invention relates to an optical scanning device for modulating a path of reflected light by operating a micromirror that reflects input light by applying a predetermined current. The scanning micromirror device according to the present invention scans a beam emitted from a light source to a predetermined area of a one-dimensional line or a two-dimensional surface to form an image such as an image or to read data such as a position or an image. It can be applied to confocal microscopes, barcode scanners, scanning displays and various sensors. In addition to the scanning, it is also applicable to an optical switch element for arbitrarily adjusting the path of the reflected light.

Recently, with the development of optical device technology, various technologies that use light as a medium for input / output terminals and information transmission of various information are emerging. Scanning and using beams from light sources is one of the traditional applications of this technology, such as barcode scanners and basic scanning laser displays. Such beam scanning technology requires various scanning speeds and scanning ranges depending on the application cases. Conventional beam scanning is implemented by adjusting the incident angle between the reflection surface of the driven mirror and the incident light such as a galvanic mirror or a rotating polygon mirror. How to do it is mainstream. Galvanic mirrors are suitable for applications requiring scan rates of several to tens of hertz (Hz), and polygon mirrors can achieve scan rates of several kilohertz (kHz).

With the development of various technologies, efforts have recently been made to apply beam scanning technology to new devices or to further improve the performance of existing applications employing these technologies. Projective display systems, head mounted displays, and laser printers are good examples. In systems requiring beam scanning requiring such high spatial resolution, a scanning mirror that can realize a high scanning speed and a large angular displacement is typically required. In the case of using a conventional polygon mirror, a motor that rotates at high speed is required. Since the polygon mirror is attached, the scanning speed is limited in increasing the scanning speed due to the limitation of the normal motor rotational speed in proportion to the rotational angular velocity of the polygon mirror and further in proportion to the rotational speed of the drive motor. The disadvantage is that it is difficult to reduce the volume and power consumption of the system. In addition, the mechanical friction noise of the drive motor unit must be fundamentally solved, and it is difficult to expect cost reduction due to the complicated structure.

1 is a view schematically showing an example of a scanning apparatus using a polygon mirror according to the prior art.

As shown in the above example, the input light 111 emitted from the light source 101 passes through the optical system 102 such as various lenses and is reflected by the polygon mirror 103. By rotating the polygon mirror 103 attached on the motor using the motor 104, the reflected light 112 can be scanned in a predetermined direction 114 defined by the rotation direction 113 of the polygon mirror. In the case of a scanning device using a polygon mirror, it is possible to implement relatively fast scanning in one direction, but there is a limitation in applying it to a display of high resolution.

2A to 2B are schematic diagrams illustrating a scanning principle of a scanning apparatus using a micromirror according to the prior art.

As shown in FIG. 2A, as the micromirror 201 rotates the torsion beams 202 formed on both sides thereof, the path of the reflected light 212 is changed to implement beam scanning. In the case of a scanning device using a micromirror, bidirectional scanning is possible, and a high scanning speed of several tens of kilohertz (kHz) can be realized. However, when the micromirror is driven in such a severe condition, as shown in FIG. The so-called dynamic deformation phenomenon occurs to cause the shape and characteristics of the reflective surface and the reflected light 212 to be distorted.

Therefore, in order to implement a high performance optical scanning device, it is necessary to select a material and a structure of a micromirror that can suppress such dynamic deformation. Conventional scanning micromirror devices using a comb-shaped electrode in the vertical direction require high alignment accuracy of the movable part and the fixed part in the manufacturing process, and the difficulty of manufacturing the structure to have a high aspect ratio in order to increase the rotation angle have. In addition, both the movable comb-shaped electrode attached to the mirror plate and the fixing part comb-shaped electrode adjacent thereto have a disadvantage of acting as a factor of increasing attenuation during driving.

SUMMARY OF THE INVENTION An object of the present invention devised to solve the above problems is to provide a scanning micromirror capable of suppressing dynamic deformation and realizing a high scanning speed and a wide scanning range.

Another object of the present invention is to provide a scanning micromirror device which can be driven by an electromagnetic force to significantly lower the driving voltage and improve structural stability and optical performance compared to the conventional micromirror to realize a fast scan speed and a wide scan range. There is.

In order to solve the above problems, the scanning micromirror of the present invention includes: a micromirror unit including a mirror plate thin film having a reflective surface reflecting input light and a frame structure supporting the mirror plate thin film; Each end of the micromirror portion is connected to include a pair of internal elastic bending structure for supporting the micromirror portion.

In the present invention, the scanning micromirror is a pair to which the other end of each of the pair of internal elastic flexural structures are connected and one end of each of the gimbals and the gimbles surrounding the micromirror portions to support the gimbals. It is preferable to further include an outer elastic flexural structure of.

In the present invention, the reflective surface is preferably formed of at least one selected from a metal or a dielectric or a stack of a metal and a dielectric.

In the present invention, the frame structure is preferably formed by arranging at least one or more unit frame structures in an array form, the frame structure is to use a diamond-shaped frame or having an empty space therein or the micromirror portion It is more preferable to further have one or more features selected from those that become thinner toward the ends.

In the present invention, the micromirror portion is preferably circular.

In the present invention, the gamble is preferably in the form of a circular ring.

In the present invention, the inner elastic flexural structure or the outer elastic flexural structure is preferably at least one selected from cantilever beam and torsion beam, respectively.

In the present invention, the pair of internal elastic flexural structures are respectively connected to the micromirror at two points each end is symmetrical with respect to a point of the central portion of the micromirror portion, the two points connected to the internal elastic flexural structure It is preferable that the micromirror portion is formed to be rotatable about a connecting axis about a central axis.

In the present invention, the pair of outer elastic flexural structure is connected to the gimbles at two points each end is symmetrical with respect to a point of the center of the gimbal, respectively, about the axis connecting the two points connected to the external elastic flexural structure It is preferable that the gimbals are formed to rotate in an axis.

In the present invention, it is preferable that the inner elastic flexural structure and the outer elastic flexural structure are connected to each other so that the axes in which they are located are perpendicular to each other.

The electromagnetic force driven scanning micromirror device of the present invention comprises: a magnetic field supply for forming a magnetic field over the entire area of the device; Located above the magnetic field supply unit, a mirror driving thin film is formed on one surface of which a current can flow, and a mirror structure on which the reflective surface reflects the input light is formed, and a frame structure supporting the mirror plate thin film. A micromirror unit in which an electromagnetic force acts by an interaction between a magnetic field by the magnetic field supply unit and a current flowing through the conductive wire; And a pair of internal elastic bending structures each end of which is connected to the micromirror part to support the micromirror part.

In the present invention, it is preferable that the reflective surface and the frame structure have similar characteristics to the reflective surface and the frame structure of the aforementioned scanning micromirror.

In the present invention, the mirror driving conductor is preferably formed in a pair symmetrical with respect to one point of the central portion of the micromirror portion.

In the present invention, the micromirror portion is preferably circular.

In an embodiment of the present invention, the electromagnetically driven scanning micromirror device may include a gamble driving lead through which the other end of each of the internal elastic bending structures may be connected, and the current may flow around the micromirror portion, and the magnetic field and the gamble by the magnetic field supply unit. It is preferable to further include a gimbal in which the electromagnetic force due to the interaction of the current flowing in the driving conductor and a pair of external elastic flexural structures connected to one end of the gimbal to support the gimbal. .

In the present invention, the gimble driving lead is preferably made of a pair symmetrical about the axis connecting the two points connected to the outer elastic structure gimble.

In the present invention, the gamble is preferably in the form of a circular ring.

In the present invention, it is preferable that the internal elastic flexural structure and the external elastic flexural structure have similar characteristics to the internal elastic flexural structure and the external elastic flexural structure of the aforementioned scanning micromirror.

In the present invention, the magnetic field supply unit preferably has a support and at least one permanent magnet attached and fixed on the support.

In the present invention, the permanent magnet is preferably composed of a cylindrical inner magnet and a hollow cylindrical outer magnet surrounding the inner magnet at a predetermined interval.

The electromagnetic force driven scanning micromirror array of the present invention is obtained by arranging the electromagnetic force driven scanning micromirror device in the form of a matrix consisting of a predetermined number of rows and a predetermined number of columns on a plane.

The optical scanning device of the present invention is characterized by using the electromagnetic force driven scanning micromirror device.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In adding reference numerals to components of the following drawings, it is determined that the same components have the same reference numerals as much as possible even if displayed on different drawings, and it is determined that they may unnecessarily obscure the subject matter of the present invention. Detailed descriptions of well-known functions and configurations will be omitted.

3A to 3B are perspective views showing one embodiment of the scanning micromirror of the present invention, in which FIG. 3A is viewed from the side in which the reflective surface of the micromirror is formed, and FIG. 3B is viewed from the side in which the conductive wire is formed. If it is.

In the embodiment of FIGS. 3A to 3B, the scanning micromirror may include an innermost circular micromirror portion 301, an internal elastic flexural structure 303 having one end connected to the micromirror portion, and the micromirror portion from outside. The other ends of the inner elastic flexural structure surrounding each other is connected, and includes a gimbal 302 having a circular ring shape, and an outer elastic flexural structure 304 each end connected to the gimbal.

In the above embodiment, the micromirror unit 301 includes a mirror plate thin film having a reflective surface for reflecting light incident on one surface and a frame structure supporting the mirror plate thin film. The reflective surface is preferably formed of at least one selected from a metal or a dielectric or a stack of a metal and a dielectric. Details of the frame structure will be described with reference to FIGS. 4A to 4B and 5A to 5C.

The inner elastic flexural structure 303 and the outer elastic flexural structure 304 respectively support the micromirror portion and the gamble, the shape of which may be any one and the other end, and can be selected from cantilever or torsion beams. It is preferable that it is 1 or more types.

In this embodiment, the pair of internal elastic flexural structures 303 are located on the X-X 'axis passing through the center of the micromirror portion and connected in a symmetrical form, and the micromirror portion is connected to the X-X' axis. Can rotate around the center.

In the embodiment, the pair of outer elastic flexural structure 304 is located on the Y-Y 'axis passing through the center of the gamble and connected in a symmetrical form, the gamble is about the Y-Y' axis Can rotate.

In the above embodiment, the X-X 'axis on which the inner elastic stretching structure is placed and the Y-Y' axis on which the outer elastic stretching structure is placed are on the same plane and orthogonal to the center point of the micromirror portion.

The gamble 302 may have any shape as long as the gamble 302 is surrounded by an outer side of the plane on which the micromirror part is placed and does not block a path in which light is directed toward the reflective surface on which the micromirror part is formed. It is preferable that the entire outline has a circular shape. In particular, as shown in the above embodiment, the micromirror portion 301 is circular, and the gamble 302 is preferably formed in the shape of a circular ring lying on the same plane as the micromirror portion.

4A to 4B are perspective views of one embodiment of the micromirror portion of the scanning micromirror of the present invention, in which FIG. 4A is viewed from above and FIG. 4B is viewed from below.

4A to 4B, the micromirror portion is supported by an internal elastic flexural structure represented by two torsion beams 403, and the torsion beam is rotated about its axis. Since the thickness of the mirror plate 401 has a relatively small value compared to the thickness of the frame structure 402, the size of the dynamic deformation during the driving of the mirror is determined by the lower frame structure. The light efficiency of can be obtained.

In the above embodiment, the frame structure may be applied to any type of structure in which the mass decreases toward the mirror end, and the width decreases or the thickness becomes thinner, as in the embodiment, toward the mirror end.

5A-5C are perspective views of one embodiment of a micromirror portion of the scanning micromirror of the present invention.

5A to 5B are cases in which the micromirror includes a frame structure having a different shape from that of the embodiment of FIG. 4B, and the rest of the components except for the frame structure are the same as those of the embodiment of FIG. 4B.

FIG. 5A illustrates a frame structure formed by arranging at least one unit frame structure 504 in an array form. In particular, the unit frame structure is formed as a diamond-shaped frame which is reduced in width toward the mirror end. When the frame structure is formed as shown in FIG. 5A, the overall rigidity of the mirror plate thin film may be increased while obtaining the same dynamic deformation reduction effect as compared with the case of using one frame structure as shown in FIG. 4B.

FIG. 5B illustrates a case in which an etching hole 505 is formed in the frame structure 504 of the array form of FIG. 5A, and may further reduce the mass and inertia of the frame structure. The etching hole may be formed in various ways according to the level of those skilled in the art, but in the present invention, it is preferable that the etching hole is formed in a hexagonal shape in a honeycomb form.

FIG. 5C illustrates a case in which the diamond array frame structure of FIG. 5A includes a frame structure 506 formed to become thinner toward the mirror end, than when the diamond unit frame of FIG. 5A uses an array of frames. The mass and inertia of the frame can be significantly reduced.

6 is a plan view from above of an embodiment of the electromagnetic force driven scanning micromirror device of the present invention, showing the rest of the magnetic field supply except the bottom.

In the embodiment of FIG. 6, the electromagnetically driven scanning micromirror device includes an innermost micromirror portion 601, a gimbal 602 that surrounds the micromirror portion just outside, the outermost substrate 605, and the A pair of internal elastic flexural structures 603 are respectively connected therebetween, and a pair of external elastic flexural structures 604 respectively connected between the outermost substrates.

In the above embodiment, the configuration of the micromirror portion 601 is not significantly different from the micromirror portion of the embodiment of FIG. 7 and will be described with reference to FIG. 7.

In the above embodiment, the inner elastic flexural structure 603 and the outer elastic flexural structure 604 is preferably at least one selected from cantilever beam and torsion beam, respectively.

In this embodiment, the internal elastic flexural structure 603 is formed of a pair formed in a shape symmetrical with each other, one end of each of the pair is two points symmetrical with respect to a point of the central portion of the micromirror portion 601 Is connected to the micromirror unit. The micromirror may rotate about the gimbal 602 about the X-X 'axis, which is an axis connecting the two points in which the internal elastic flexural structure is connected to the micromirror. The rotational motion will be described with reference to FIG. 11.

In this embodiment, the outer elastic flexural structure 604 is formed of a pair formed in a shape symmetrical with each other, one end of each of the pair at two points symmetrical with respect to one point of the center of the gimbal 602 Is connected to the gamble. The gamble may rotate about the substrate 605 about a Y-Y 'axis, which is an axis connecting two points connected to the external elastic flexural structure. The rotational motion will be described with reference to FIG. 12.

In the above embodiment, the micromirror unit 601 rotates about the X-X 'axis and the gimble 602 to which the micromirror unit is connected may rotate about the Y-Y' axis, thereby allowing the micromirror to rotate. The part has different angular displacements for both axes X_X 'and Y-Y', and the whole electromagnetically driven scanning micromirror device can adjust the scanning in two directions.

When the X-X 'axis and the Y-Y' axis are orthogonal to each other on the same plane as shown in the above embodiment, the light reflected from the reflection surface formed on one surface of the micromirror portion is scanned for all the ranges of the 3D space. Therefore, the X-X 'axis on which the inner elastic stretching structure is placed and the Y-Y' axis on which the outer elastic stretching structure is placed are preferably orthogonal to each other on the same plane.

7A to 7B are perspective views illustrating all parts of the electromagnetic force driven scanning micromirror device of the present invention except for the magnetic field supply unit. FIG. 7A is a view of the same embodiment when the reflective surface of the micromirror unit is formed. 7B is the case seen from the surface side in which the conducting wire was formed. 7A to 7B also illustrate an embodiment of the scanning micromirror of the present invention.

In the embodiment of FIGS. 7A to 7B, the micromirror portion 701 has a circular outer shape, and a mirror driving wire through which a current flows is formed on one side thereof and reflects the input light on the other side thereof. A mirror plate thin film having a reflective surface and a frame structure supporting the mirror plate thin film and having a diamond-shaped unit frame structure arranged in an array form, and a pair of internal elastic bending structures 703 configured to be symmetrical to each other, respectively One end of is connected to the micromirror portion at a point symmetrical with respect to the micromirror center point.

The reflective surface is preferably formed of at least one selected from a metal or a dielectric or a stack of a metal and a dielectric.

In the embodiment, the frame structure is a diamond-shaped unit frame structure is arranged in an array form, the configuration is not significantly different from any one of the embodiment shown in Figs. 5a to 5c except that the overall outline is in the shape of a circle. not.

In the embodiment of FIG. 7B, the current flows into the micromirror portion through the internal elastic flexural structure, passes through the outer half of the micromirror portion, traverses the micromirror portion in the radial direction, and passes through when entering the micromirror portion. Two conductors, symmetrically shaped, first and second mirror drive coils 711, 712 are shown arranged to exit the micromirror portion through the elastic flexural structure. The arrangement of the two conductors and the electromagnetic force generated by the interaction between the current flowing through the two conductors and the magnetic field will be described with reference to FIGS. 8 and 11.

The above embodiment shows the rest of the embodiments of the electromagnetic force driven scanning micromirror device of the present invention except for the magnetic field supply in the device for adjusting the scanning in one axis direction. When the other end not connected to the micromirror portion of the pair of inner elastic flexural structures is directly connected to the outside and driven with a magnetic field supply part at the bottom thereof, the micromirror portion is rotated while being supported by the internal elastic flexural structure, so that the entire electromagnetic force The drive scanning micromirror device adjusts the scanning in the direction of one axis. In the embodiment of FIG. 6, there is no gamble and an external elastic stretching structure, and thus the micromirror portion is directly connected to an external substrate and rotates about an X-X 'axis to control scanning.

FIG. 8 is a plan view from above of an embodiment of the electromagnetically driven scanning micromirror device of the present invention, showing the arrangement of the conductors in FIG.

The embodiment of FIG. 8 is represented by further including four electrodes and eight electrodes provided on the substrate in the configuration of the embodiment of FIG. 6. Hereinafter, four conductors of the first and second gamble driving coils and the first and second mirror driving coils will be described in detail with reference to FIG. 8.

The first mirror drive coil 811 is connected at both ends to the first mirror drive coil electrode 1821 and the first mirror drive coil electrode 2822, respectively, and the upper portion of the pair of external elastic bending structures. It is provided over a thing, a gamble, a left side of a pair of internal elastic flexural structures, and a micromirror part. The second mirror drive coil 812 is connected at both ends to the second mirror drive coil electrode 182 and the second mirror drive coil electrode 2 824 at the bottom thereof, and the bottom of the pair of outer elastic bending structures. One, the gamble, the right of the pair of internal elastic flexural structures, and the micromirror portion.

The first gamble driving coil 813 is connected to both ends of the first gamble driving coil electrode 1 825 on the upper side and the first gamble driving coil electrode 2 826 on the lower side thereof, and has a pair of external elastic bending structures. It is placed over the gamble. The second gamble driving coil 814 is connected to both ends of the second gamble driving coil electrode 1 827 and the second second gamble driving coil electrode 2 828 at the bottom thereof, and has a pair of external elastic bending structures. It is placed over the gamble.

As shown in the above embodiment, the first and second gamble driving coils are preferably arranged in a symmetrical manner with respect to the Y-Y 'axis, which is an axis connecting two points connected to the external elastic flexural structure. Do.

As shown in the above embodiment, the first mirror driving coil and the second mirror driving coil are arranged at one point of the central portion of the micromirror portion, particularly in the case where the micromirror portion is formed in a circular shape and symmetrical with respect to the center point thereof. desirable.

9A to 9B are perspective views showing an embodiment of a magnetic field supply unit of the electromagnetic force driven scanning micromirror device of the present invention, and in particular, FIG. 9B illustrates an embodiment of a path through which a current flows over the magnetic field supply unit in the present invention. .

In the embodiment of FIG. 9A, the magnetic field supply unit surrounds the inner magnet at a predetermined distance from the support 901 and two permanent magnets provided on the support, and a cylindrical inner magnet 902 provided at the center of the support. A hollow cylindrical outer magnet 903 is included.

In the embodiment of FIG. 9B, a path through which a current flows is located on a plane located above and parallel to the plane on which the magnetic field supply of the embodiment of FIG. 9A lies, and a predetermined line on the plane passing vertically upward of the center point of the magnetic field supply ( It is composed of a pair symmetrical to L) and formed to include a semicircle shape in the center of each straight line.

In this embodiment, the current flows from the upper left to the lower right in the paths through which the current flows to the left and the right, and the magnetic field Br of a component extending radially from the center of the magnetic field supply part affects the path through which the current flows. give. The electromagnetic force is generated by the interaction between the current and the magnetic field. In a straight portion of the two current paths, the direction of the current and the direction of the radial component of the magnetic field are parallel to each other, so that an electromagnetic force having a significant magnitude is related to the action of the present invention. However, in the shape of the semicircle, the electromagnetic force is generated in the downward direction in the path through which the current on the left flows and upward in the path through which the current on the right flows.

If both ends of the path through which the entire current flows are fixed, the electromagnetic force generated in the shape of the semicircle is the torque T causing the rotational movement about the line L, the reference of which the path through which the current flows is symmetric with each other. As a result, the path through which the entire current flows is rotated.

10 is a cross-sectional view taken along line AA ′ of FIG. 8 of an embodiment of the electromagnetically driven scanning micromirror device of the present invention with one embodiment of the magnetic field supply shown in FIG. 9A below the micromirror. .

In the embodiment of FIG. 10, the electromagnetically driven scanning micromirror device has a magnetic field supply having a support 901 located below and two permanent magnets, an inner magnet 902 and an outer magnet 903 attached thereon, above the magnetic field supply. A micromirror portion 801 having a conductive line located at the center facing downward, a gimbal 802 that surrounds the micromirror portion just outside the same plane in which the micromirror portion is placed, and a substrate that surrounds the gimbal at the outermost portion ( 805).

The electromagnetic force driven scanning micromirror device of the present invention can adjust scanning about two axes. For this purpose, it is efficient to use a radial magnetic field directed from the center to the outside on a plane on which a mirror plate is formed. In order to increase the radial component of the magnetic field, at least one permanent magnet provided by the magnetic field supply unit on the support is preferably cylindrical.

Only one permanent magnet may be used for the magnetic field supply unit, but as shown in the above embodiment, the hollow cylindrical outer magnet 903 surrounding the inner magnet is spaced apart from the inner magnet 902 at a predetermined interval 904. It is more preferable to use two permanent magnets. In this embodiment, the inner magnet is magnetized in the vertical upward direction, the outer magnet is magnetized in the vertical downward direction so that a magnetic field B extending radially from the center acts on the micromirror portion, the radial magnetic field B. Is significantly larger in size than there is only one inner magnet magnetized vertically upward. As the magnitude of the magnetic field increases, the magnitude of the total electromagnetic force also increases in proportion to the magnitude of the magnetic field, so that the electromagnetic force driving scanning micromirror can be driven with a relatively small current.

In this embodiment, the higher the relative permeability of the material of the support 901 disposed under the entire permanent magnet region, the higher the symmetry of the magnetic field caused by the permanent magnet, and thus the radial The electromagnetic force caused by the magnetic field in directions other than the directions cancels out more efficiently. Therefore, the support is preferably formed of a material having a high specific permeability.

FIG. 11 is a plan view from above of an embodiment of an electromagnetic force driven scanning micromirror device of the present invention, showing a portion associated with the rotational motion of the micromirror portion.

11 shows only a part of FIG. 8, except that only the first and second mirror driving coils 811 and 812 are displayed among the four conductive wires, and the rest of the configuration is the same as that of FIG. 9.

In the above embodiment, a current flows from the first mirror drive coil electrode 1821 to the first mirror drive coil electrode 2 822 in the first mirror drive coil 811, and the second mirror drive coil 812. The current flows from the second mirror drive coil electrode 182 to the second mirror drive coil electrode 2 824. The magnetic field supplying portion in which the central portion is located directly below the central portion of the micromirror portion is the same as the embodiment of FIG. 8A and forms a magnetic field extending radially from the center point of the micromirror portion.

In the above embodiment, in the other parts of the first and second mirror drive coils, the direction of the magnetic field and the current are parallel so that no electromagnetic force is generated or the conductors flowing in the opposite directions are adjacent to each other, so that the magnetic field and the current interact. Although the electromagnetic force due to almost does not work, in the portion of the shape of the two semicircles formed along the end of the micromirror portion 801, a significant electromagnetic force is generated and acts in relation to the operation of the present invention.

The electromagnetic force caused by the current flowing in the upper semicircle corresponding to the first mirror driving coil 811 among the shapes of the two semicircles is generated in a downward direction, and is applied to the lower semicircle corresponding to the second mirror driving coil 812. The electromagnetic force caused by the flowing current is generated in the upward direction.

Electromagnetic forces acting on two coils formed along the ends of the micromirror portion 801 move the micromirror portion, and the entire micromirror portion is placed on the gimbal 802 placed on the same plane by the internal elastic flexural structure 803. It is connected and supported, thereby causing a rotational movement about an axis of the plane on which the internal elastic flexural structure is placed. The degree of rotational motion is dependent on the magnitude of the generated electromagnetic force, which depends primarily on the magnitude of the current flowing through the first and second mirror drive coils, rather than the adjustment of the magnitude of the magnetic field or the distance between the magnetic field supply and the micromirror portion. When the magnitude of the electromagnetic force is reduced, the micromirror portion returns to the state before the rotational movement by the repulsive force by the internal elastic flexural structure made of an elastic body.

12 is a plan view from above of an embodiment of an electromagnetic force driven scanning micromirror device of the present invention, showing a portion related to the rotational motion of the gimbal.

12 shows only a part of FIG. 8, except that only the first and second gamble driving coils 813 and 814 are displayed among the four conductive lines.

In the above embodiment, a current flows from the first gamble drive coil electrode 1 825 to the first gamble drive coil electrode 2 826 in the first gamble drive coil 813, and the second gamble drive coil 814. Current flows from the second gamble driving coil electrode 1 827 to the second gamble driving coil electrode 2 828. The magnetic field supplying portion in which the central portion is located directly below the central portion of the gimbal is the same as the embodiment of FIG. 8A and forms a magnetic field extending radially from the center point of the gimbal.

In the above embodiment, in other parts of the first and second gamble drive coils, the direction of the magnetic field and the current are parallel, so that no electromagnetic force is generated, but in the part of the shape of two semicircles formed along the ends of the gamble, the function of the present invention In relation to this, a significant electromagnetic force is generated and acted upon.

The electromagnetic force generated by the current flowing in the semicircle on the left side corresponding to the first gamble driving coil 813 among the shapes of the two semicircles is generated in a downward direction, and is applied to the current flowing in the semicircle on the right side corresponding to the second gamble driving coil 813. The electromagnetic force is generated in the upward direction.

The electromagnetic force acting on the two coils formed along the ends of the gimbals 802 moves the gimbals, and the entire gimbals are connected to and supported by the substrate 805 lying on the same plane by an external elastic flexural structure 804. The outer elastic flexural structure is rotated about an axis on a plane. The degree of rotational movement is dependent on the magnitude of the generated electromagnetic force, which is primarily dependent on the magnitude of the current flowing through the first and second gimbal drive coils rather than the adjustment of the magnitude of the magnetic field or the distance between the magnetic field supply and the micromirror portion. When the magnitude of the electromagnetic force is reduced, the gamble is returned to the state before the rotational movement by the repulsive force by the external elastic flexural structure made of an elastic body.

The electromagnetic force driven scanning micromirror device of the present invention is easily used to reflect and scan light incident from one light source. It is preferred that the devices be arranged in an array to control the scanning of light incident from a plurality of light sources. When the electromagnetically driven scanning micromirror devices formed through the micromachining technique or the micromachining process are arranged in an array of several predetermined rows and columns, scanning of the wavefront of the light reflecting the light incident on the array can be controlled. .

The electromagnetic force driven scanning micromirror device of the present invention can be used in a conventional conventional optical scanning apparatus using a micromirror. In the conventional conventional optical scanning apparatus, it is preferable to configure the optical scanning apparatus by using the device in place of a driving unit such as a micromirror and an electromagnetic force driver or a step motor for driving the mirror, in which case the optical scanning apparatus is wider. It has a scanning range and a faster scanning speed.

As described above, it has been described with reference to the preferred embodiment of the present invention, but those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

As described above, according to the present invention, the dynamic deformation of the scanning micromirror is suppressed, and a wide scan range and a high scan speed can be realized by two-axis driving.

In addition, according to the present invention, it is possible to apply both the single-axis or two-axis driving method, high productivity, high economical efficiency, can be driven by the electromagnetic force can significantly lower the driving voltage, and compared with the conventional micromirror structural stability and optical The performance is enhanced to provide an electromagnetically driven scanning micromirror device capable of high scan rates and wide scan ranges.

Claims (34)

A micromirror unit including a mirror plate thin film having a reflective surface reflecting input light and a frame structure supporting the mirror plate thin film; Scanning micromirror including a pair of internal elastic stretching structure, each end of which is connected to the micromirror portion to support the micromirror portion. According to claim 1, The other end of each of the pair of inner elastic flexural structure is connected to each other and the gimbal (gimbal) surrounding the micromirror portion and a pair of outer elastic to support the gimbal A scanning micromirror further comprising an flexing structure. The scanning micromirror according to any one of claims 1 to 3, wherein the reflective surface is formed of at least one selected from a metal or a dielectric or a stack of a metal and a dielectric. The scanning micromirror of claim 1, wherein the frame structure is formed by arranging at least one unit frame structure in an array form. The scanning micromirror of claim 4, wherein the unit frame structure uses a diamond frame. 5. The scanning micromirror of claim 4, wherein the unit frame structure has an empty space therein. The scanning micromirror of claim 4, wherein the unit frame structure becomes thinner toward the end of the micromirror portion. The scanning micromirror according to any one of claims 1 to 3, wherein the micromirror portion is circular. The scanning micromirror according to any one of claims 1 to 4, wherein the internal elastic flexural structure is at least one selected from cantilever beams and torsion beams. The micromirror assembly as claimed in claim 1, wherein the pair of internal elastic flexural structures are respectively connected to the micromirror portions at two points, each end of which is symmetrical with respect to one point of the central portion of the micromirror portion, And a micromirror portion configured to rotate in a central axis about an axis connecting two points to which the internal elastic flexural structure is connected. The scanning micromirror according to claim 2, wherein the gamble is in the form of a circular ring. The scanning micromirror according to claim 2, wherein the outer elastic flexural structure is at least one selected from cantilever beams and torsion beams. The pair of outer elastic flexural structures of claim 2, wherein each of the pair of outer elastic flexural structures is connected to the gamble at two points each end of which is symmetrical with respect to one point of the center of the gamble, and connects two points to which the external elastic flexural structures are connected. Scanning micromirror, characterized in that the gimbal is formed to rotate the axis about the axis. 3. The scanning micromirror of claim 2, wherein the inner elastic flexural structure and the outer elastic flexural structure are connected to each other such that axes in which they are positioned are perpendicular to each other. A magnetic field supply forming a magnetic field over the entire area of the device; Located above the magnetic field supply unit, a mirror driving thin film is formed on one surface of which a current can flow, and a mirror structure on which the reflective surface reflects the input light is formed, and a frame structure supporting the mirror plate thin film. A micromirror unit in which an electromagnetic force acts by an interaction between a magnetic field by the magnetic field supply unit and a current flowing through the conductive wire; And a pair of internal elastic flexural structures, each end of which is connected to the micromirror portion, to support the micromirror portion. 16. The electromagnetic force driving scanning micromirror device according to claim 15, wherein the reflective surface is formed of at least one selected from a metal or a dielectric or a stack of a metal and a dielectric. The electromagnetic force driven scanning micromirror device of claim 15, wherein the frame structure is formed by arranging at least one unit frame structure in an array. 18. The electromagnetic force driven scanning micromirror device according to claim 17, wherein the unit frame structure uses a diamond frame. 18. The electromagnetic force driven scanning micromirror device according to claim 17, wherein the unit frame structure has an empty space therein. 18. The scanning device of claim 17, wherein the unit frame structure becomes thinner toward the end of the micromirror portion. 16. The electromagnetic force driven scanning micromirror device according to claim 15, wherein the mirror driving lead is formed in a pair symmetrical with respect to one point of the central portion of the micromirror portion. 16. The electromagnetic force driven scanning micromirror device according to claim 15, wherein the micromirror portion is circular. 16. The electromagnetic force driven scanning micromirror device according to claim 15, wherein the internal elastic flexural structure is at least one selected from cantilever beams or torsion beams. 16. The method of claim 15, wherein the pair of internal elastic stretching structures are respectively connected to the micromirror portion at two points each end is symmetrical with respect to a point of the central portion of the micromirror portion, An electromagnetic force driven scanning micromirror device, characterized in that the micromirror portion is formed to rotate about a central axis connecting a dot. 16. The method of claim 15, wherein the other end of each of the pair of internal elastic flexural structure is connected to the micro-mirror portion is provided with a gimble driving lead that can flow the current, the magnetic field by the magnetic field supply and the gimble driving lead Electromagnet drive characterized in that it further comprises a gimbal (gimbal) to move the movement due to the interaction of the current flowing in the movement and a pair of external elastic flexural structure that is connected to each end of the gimbal to support the gamble. Scanning Micromirror Device. 26. The electromagnetic force driven scanning micromirror device according to claim 25, wherein the gimble driving lead is a pair symmetrical about an axis connecting two points connected to the external elastic structure. 27. The electromagnetic force driven scanning micromirror device according to claim 25, wherein the gamble is in the form of a circular ring. 26. The electromagnetic force driven scanning micromirror device according to claim 25, wherein the outer elastic flexural structure is at least one selected from cantilever beams or torsion beams. 26. The method of claim 25, wherein the pair of outer elastic flexural structures are each connected to the gamble at two points each end is symmetrical with respect to a point of the center of the gimbal, the gimbal is connected to the external elastic flexural structure An electromagnetic force driven scanning micromirror device, characterized in that it is formed so as to be able to rotate about a substrate about an axis connecting two points. 26. The electromagnetic force driven scanning micromirror device according to claim 25, wherein the internal elastic flexural structures and the external elastic flexural structures are respectively connected such that the axes in which they are positioned are perpendicular to each other. 16. The electromagnetic force driven scanning micromirror device according to claim 15, wherein the magnetic field supply portion includes a support and at least one permanent magnet attached to and fixed on the support. 32. The electromagnetic force driven scanning micromirror device of claim 31, wherein the permanent magnet comprises a cylindrical inner magnet and a hollow cylindrical outer magnet surrounding the inner magnet at a predetermined interval. An electromagnetic force driven scanning micromirror array according to claim 15, wherein the electromagnetic force driven scanning micromirror device is arranged in a matrix consisting of a predetermined number of rows and a predetermined number of columns on a plane. 16. An optical scanning device using the electromagnetic force driven scanning micromirror device of claim 15.

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