KR100789574B1 - Scanning micromirror - Google Patents

Abstract

A scanning micro-mirror is provided to allow the scanning micro-mirror to be fabricated through a micro-machining process and apply to various beam scanning systems such as a high-functional scanning system and a system of demanding static displacement by preventing the deterioration of optical performance. A scanning micro-mirror includes a substrate(110) having an opening region. A first Gimbal(140) having a ring shape is coupled with the substrate through a first elastic body(144) on the opening region to move with the first elastic body used as a rotational axis. A second Gimbal(130) having a ring shape is coupled with the first Gimbal through a second elastic body(142) in an inside of the first Gimbal to move with the second elastic body used as a rotational axis. A mirror plate(120) is coupled with a reinforcement rim(122) through a connecting body(124) in an inside of the reinforcement rim to move with first, second and third elastic bodies used as a rotational axis. The reinforcement rim is connected with the second Gimbal through the third elastic body(132).

Description

Scanning micromirror

1 is a perspective view schematically showing a projection display structure using a conventional two-axis scanning micromirror.

Figure 2 is a perspective view schematically showing the structure of a projection display using a conventional one-axis scanning micromirror and galvanometric mirror.

3 schematically illustrates the structure of a scanning display system in which a typical scanning micromirror is implemented in combination with a laser array.

4 is a top perspective view showing the structure of a scanning micromirror according to an embodiment of the present invention.

5 is an enlarged perspective view illustrating a gamble structure of a scanning micromirror according to an exemplary embodiment of the present invention.

FIG. 6 is a side cross-sectional view of the scanning micromirror shown in FIG. 4 based on the X-X 'axis. FIG.

FIG. 7 is a side cross-sectional view based on the Y-Y 'axis of the scanning micromirror shown in FIG. 4; FIG.

8 is a bottom perspective view showing the structure of a scanning micromirror according to an embodiment of the present invention.

9 is an enlarged bottom perspective view illustrating a gamble structure of a scanning micromirror according to an exemplary embodiment of the present invention.

10 is a diagram illustrating the basic driving principle of the magnet and the coil provided in the scanning micromirror according to the embodiment of the present invention.

11 is a diagram illustrating a two-axis driving principle when the coil of the scanning micromirror according to the embodiment of the present invention is provided with two lines.

12 is a diagram illustrating a two-axis driving principle when the coil of the scanning micromirror according to the embodiment of the present invention is provided in one line.

13 is a plan view showing a structure in which a coil of a scanning micromirror according to an embodiment of the present invention is disposed on a first gamble, a second gamble, and a mirror plate;

FIG. 14 is a diagram illustrating a simulation result of a resonant mode of a scanning micromirror according to a first embodiment of the present invention by finite element analysis. FIG.

15 is a graph illustrating frequency waveforms of resonance modes of a scanning micromirror according to an exemplary embodiment of the present invention.

16 is a top view illustrating a structure in which a coil of a scanning micromirror is single-layer wound to three input / output lines according to an exemplary embodiment of the present invention.

17 is a top view illustrating a structure in which a coil of a scanning micromirror is wound in two layers with two input / output lines according to an exemplary embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

100: scanning micromirror according to the present invention

110: substrate 120: mirror plate

122: reinforced frame 124: connecting body

130: second gimbal 132: third elastic body

140: first gimbal 142: second elastic body

144: first elastic body 150: coil

160: magnet 162: support

164: ring magnet 166: cylindrical magnet

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device, and more particularly, a scanning micromirror that forms an image or reads data by scanning a beam emitted from a light source into a 1D or 2D region. It is about.

Along with the development of optical device technology, various technologies that use light as an input / output terminal and information transfer medium of various information are emerging, such as a barcode scanner or a basic scanning laser display. A typical example is a technique of scanning and using a beam emitted from a light source. In particular, recently, a system using high spatial resolution beam scanning has been developed, and such a system is a projection display system having excellent high-resolution primary color reproducibility using laser scanning. ), HMD (Head Mounted Display), and laser printer.

This beam scanning technique requires a scanning mirror having various scanning speeds and scanning ranges (angular displacements, tilting angles), depending on the application. Conventional beam scanning requires a galvanic mirror. And the angle of incidence between the incident light and the reflective surface of the driven mirror, such as a rotating polygon mirror).

Scanning speeds of several to tens of hertz (Hz) can be realized when using galvanic mirrors, and scanning speeds of several kilohertz (kHz) can be realized when using polygonal mirrors. That is, in the case of the polygon mirror, since the polygon mirror is mounted on the motor that rotates at high speed, the scanning speed is proportional to the rotational angular velocity of the polygon mirror, which is dependent on the rotational speed of the drive motor, thus limiting the conventional motor rotation speed. Due to the limitation in increasing the scanning speed, there is a disadvantage that it is difficult to reduce the volume and power consumption of the entire 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.

On the other hand, in the case of a scanning device using a micromirror, bidirectional scanning is possible, and a high scanning speed of several tens of kHz can be realized.

1 is a perspective view schematically showing a projection display structure using a general two-axis scanning micromirror.

As shown in FIG. 1, the biaxial scanning micromirror can be biaxially driven through the gamble 2 and the mirror plate 1, and independent driving signals are input to the gamble 2 and the mirror plate 1, respectively. The shape in which the input light L1 is reflected and scanned into the two-dimensional image L2 is shown.

As such, in order to implement two-axis scanning using a micromirror, a method of using a two-axis scanning micromirror with a gimbal structure, a method of using a separate one-axis scanning mirror for two driving axes, a scanning micromirror and a galvanometric Or a mirror or laser array.

FIG. 2 is a perspective view schematically illustrating the structure of a projection display using a general uniaxial scanning micromirror and a galvanometric mirror, and FIG. 3 is a schematic view of a structure of a scanning display system in which a general scanning micromirror is combined with a laser array. It is a figure shown.

According to FIG. 2, the light incident from the light source 1 is reflected by the micromirror 3 via the optical system 2 composed of several lenses. At this time, the magnet 4 is provided on the side of the micromirror 3 to form an electromagnetic field, and the micromirror is driven in the horizontal direction to convert incident light into line segments on the x-axis. The converted light is composed of components on the y-axis by the galvanometric mirror driven in the vertical direction, thereby producing a two-dimensional image L3 as a whole.

In addition, according to FIG. 3, the light source, that is, the laser array 6 configures and scans the light of the horizontal component and the light on the x-axis, and the lens 7 evenly arranges the light and transmits it to the micromirror 8. The micromirror 8 is vertically driven to form a two-dimensional image L4 by reflecting light.

In this case, a two-axis scan for display requires a high scan rate of several tens of kHz in the horizontal direction, while a relatively low speed of several tens of Hz is required in the vertical direction. Resonant driving method is used to secure the angle, and forced driving method is used in the vertical direction.

However, in the case of the conventional constant power drive scanning micromirror using the comb electrode in the vertical direction, the high alignment accuracy of the movable part or the rotor and the fixed part or stator in the manufacturing process In order to increase the rotation angle, there is a difficulty in manufacturing a structure having a high aspect ratio. In addition, both the movable comb-shaped electrode attached to the mirror plate and the fixed comb-shaped electrode adjacent thereto have a disadvantage of acting as a factor of increasing damping during driving.

The present invention is manufactured through a micromachining process or a micromachining process, and can be applied to both uniaxial or biaxial driving methods, and can realize a faster scanning speed and a wider driving angle (scanning range). Structural stability to high speed operation is secured, and optical performance is prevented from being degraded according to conventional physical operations, so that scanning is applicable to various beam scanning systems such as a high performance scanning system requiring high spatial resolution and a system requiring static displacement. It is an object to provide a micromirror.

Scanning micromirror according to the present invention comprises a substrate having an open area; A ring-shaped first gimbal coupled to the substrate on the open area through a first elastic body and driven with the first elastic body as a rotation axis; A ring-shaped second gimbal coupled to the inside of the first gimbal through a second elastic body and driven using the second elastic body as a rotating shaft; A mirror plate coupled to the inside of the second gamble through a third elastic body and driven using the first elastic body, the second elastic body, and the third elastic body as a rotating shaft; A coil coupled to the elastic body, the gimbal, and the mirror plate to form an electromagnetic field to generate a driving force; And a magnet coupled to the bottom surface side of the substrate and forming an electromagnetic field together with the coil.

In addition, the scanning micromirror according to the present invention is located between the mirror plate and the second gamble, connected to the mirror plate through a plurality of connecting bodies, and connected to the second gamble through the third elastic body, And a reinforcing frame driven together with the mirror plate using the third elastic body as a rotation axis.

In addition, the second elastic body and the third elastic body of the scanning micromirror according to the present invention are located on a straight line to provide a rotation axis of the second gimbal and the mirror plate, and the first elastic body is the second elastic body and the It is positioned perpendicular to the axis of rotation of the third elastic body is characterized in that to provide a rotation axis of the first gamble.

In addition, the elastic body of the scanning micromirror according to the present invention comprises one or more torsion bars, the torsion bar is characterized in that the combination of one or more forms of straight or curved.

In addition, the magnet of the scanning micromirror according to the present invention is a ring-shaped magnet; Cylindrical magnets spaced apart from inside the ring magnet; And it characterized in that it comprises a support for coupling the ring-shaped magnet and the cylindrical magnet on the bottom side.

In addition, the second gamble and the mirror plate of the scanning micromirror according to the present invention are forcibly driven based on the rotation axis of the first elastic body when a low frequency first frequency signal is applied to the coil. When the second frequency signal of the band is applied, it is characterized in that the resonance drive based on the rotation axis of the second elastic body and the third elastic body.

In addition, the elastic body of the scanning micromirror according to the present invention is composed of two parts which are located opposite to each other, the coil is a single wire and single layer structure, and constitutes a first gamble path from one side of the first elastic body to one side of the second elastic body. After forming one side semi-circular path of the second gamble, and penetrates the mirror plate from the other side second elastic body to the one side second elastic body, and constitutes a first gamble path from the second elastic body to the other first elastic body A first coil part; And constructing a first gamble path from the first elastic body to the other second elastic body, penetrating the mirror plate from the second elastic body to the second elastic body, and configuring the other half-circle path of the second gimbal. And a second coil part constituting a first gamble path from the other second elastic body to the other first elastic body.

In addition, the elastic body of the scanning micromirror according to the present invention is composed of two parts that are respectively opposed to each other, the coil is a double wire and a multi-layer structure, branched from the input line of one side of the first elastic body is circular on the first gamble A first coil part forming a path and forming an output line with the other first elastic body; And the first coil part is insulated from the first elastic body and enters the second gimbal through one side second elastic body, forms a circular path on the second gimbal, and then passes the other first elastic body through the other second elastic body. It characterized in that it comprises a second coil portion for forming the output line from the elastic body.

In addition, the elastic body of the scanning micromirror according to the present invention is composed of two parts that are opposed to each other, the coil is a double wire and single-layer structure, bidirectional on the first gamble from the first elastic body to the other first elastic body, respectively A first coil part and a second coil part constituting a semicircular path; And a second entry into the second gimbal from the first elastic body on one side through the second elastic body, and form a circular path on the second gimbal, and then form an output line to the other first elastic body through the second elastic body on the other side. It characterized in that it comprises a coil unit.

Hereinafter, a scanning micromirror according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

4 is a top perspective view showing the structure of a scanning micromirror 100 according to an embodiment of the present invention, Figure 5 is an enlarged top perspective view showing a gamble structure of the scanning micromirror 100 according to an embodiment of the present invention. to be.

6 is a side cross-sectional view based on the X-X 'axis of the scanning micromirror 100 shown in FIG. 4, and FIG. 7 is a Y-Y' axis of the scanning micromirror 100 shown in FIG. Side cross-sectional view as a reference.

First, referring to FIGS. 4 and 5, the scanning micromirror 100 according to the present invention includes a substrate 110, a first elastic body 144, a first gimbal 140, and a second elastic body. 142, a second gimbal 130, a third elastic body 132, a reinforcement rim 122, a connector 124, a mirror plate 120, and a coil 150. It is made to look at each component as follows.

An opening (the opening is shown as having a rectangular shape in the drawing, but may have a circular shape corresponding to the gamble structure) is formed on the substrate 110, and the first gamble 140 and the first opening are formed in the opening 110. The two gimbals 130, the reinforcement frame 122, and the mirror plate 120 are sequentially disposed.

The mirror plate 120 is connected to the reinforcement frame 122 through the connecting body 124, the reinforcement frame 122 is connected to the second gamble 130 through the third elastic body 132.

The mirror plate 120 may be formed of a laminated structure including a metal and a dielectric. The mirror plate 120 may have a flat structure with a uniform thickness or a convex center portion thicker than an outer portion.

In addition, the second gamble 130 is connected to the first gamble 140 through the second elastic body 142 and the first gamble 140 is connected to the substrate 110 through the first elastic body 144. The mirror plate 120, the reinforcement frame 122, the first gamble 140, and the second gamble 130 are supported on the substrate 110, and the first elastic body 144, the second elastic body 142, and the first elastic body 142 are formed on the substrate 110. Each of the three elastic bodies 132 may flow at a predetermined rotation angle.

The first elastic body 144, the second elastic body 142, and the third elastic body 132 are each composed of two parts, and are positioned at opposite ends to support the structure.

The reinforcement frame 122 is a component for preventing the mirror plate 120 from being thermally deformed (for example, the mirror plate may be distorted due to external heat) or fluttering when moving (dynamic deformation). The mirror plate 120 is connected to the plurality of connectors 124 and flows in the same direction and rotation angle with the mirror plate 120.

The third elastic body 132 is a component that acts as a kind of spring (torsion bar), and serves as a rotating shaft at both ends of the mirror plate 120 (including the reinforcement frame 122), the mirror plate ( When 120 is driven to provide a restoring torque (Torque).

The second elastic body 142 also serves as a kind of spring, and acts as a rotating shaft at both ends of the second gamble 130, and provides a restoring force torque when the second gamble 130 is driven.

The first elastic body 144 also serves as a kind of spring, and serves as a rotation axis at both ends of the first gamble 140, and provides a restoring force torque when the first gamble 140 is driven.

The second elastic body 142 and the third elastic body 132 are positioned in a straight line to form the same axis, and the first elastic body 144 is perpendicular to the second elastic body 142 and the third elastic body 132. In order to realize two-axis driving, the first and second gimbals 140 and 130 are biaxially driven by the first elastic body 144 and the second elastic body 142, and the mirror plate 120 And the reinforcement frame 122 may be driven with the angular displacement amplified by the force transmitted through the third elastic body 132.

The driving mode of the scanning micromirror 100 according to the present invention will be described later with reference to FIGS. 14 and 15.

The mirror plate 120, the reinforcement frame 122, the first gamble 140, and the second gamble 130 may be manufactured in any form, but may flow in two axes so that the reflection (irradiation) region of each axis may be provided. It is preferable that it is circular or elliptical.

The elastic bodies 144, 142, and 132 may have a form of a cantilever, a torsion beam, a meander beam, or the like.

4 and 5, the first elastic body 144, the first gamble 140, the second elastic body 142, the second gamble 130, the third elastic body 132, and the mirror plate 120. A coil 150 is formed on an upper surface of the magnet 150, and a magnet (see FIGS. 10 to 12; 160) is coupled to the bottom of the substrate 110. When a current is supplied to the coil 140, the magnet 160 is formed. ), It interacts with the magnetic field and generates the physical force, that is, the Lorentz force.

The first gamble 140, the second gamble 130, and the mirror plate 120 coupled to the coil 150 by the force of the Lorentz flow about two axes.

The coil 150 may be made of a metal such as Ti, Cr, Cu, Ag, Ni, Al, or a single material such as ITO (Indium Tin Oxide), a conductive polymer, or a combination thereof, and the details of the coil 150 The structure and the flow of current will be described later in detail with reference to FIGS. 13, 16, and 17.

Referring to FIG. 6, a side cross-sectional view of the scanning micromirror 100 is shown based on the X-X 'axis (first elastic body 144 axis) shown in FIG. 4, and the first elastic body 144 is shown in FIG. It is formed thinner than the third elastic body 132, it can be seen that the second gimbal 130 is coupled to the first gamble 140 side.

The second gamble 130 is coupled to the first gamble 140 by considering the position and the direction of the magnetic field generated from the magnet 160 under the substrate 110. At this time, Lorentz's force is the most. Well communicated.

However, in this case, the separation distance between the second gamble 130 and the first gamble 140 is shortened, and the second elastic body 142 is also formed short so that a sufficient driving force cannot be generated.

Therefore, the second gamble 130 has a shape in which a portion connected to the second elastic body 142 is bent toward the mirror plate 120, and the second elastic body 142 is connected to the bent portion, thereby forming a second elastic body. 142 may be formed long.

Referring to FIG. 7, a cross-sectional side view of the scanning micromirror 100 is illustrated based on the Y-Y ′ axis (the second elastic body 142 and the third elastic body 132 axis) shown in FIG. 4. The second elastic body 142 is thinner than the third elastic body 132.

Thus, the first elastic body 144 and the second elastic body 142 is formed thinner than the third elastic body 132, the first elastic body 144 and the second elastic body 142 serves as a rotation axis for biaxial drive On the other hand, because the third elastic body 132 serves to transmit the rotational force generated from the gimbals (130, 140) to the mirror plate (120).

Although not shown in the drawings, an insulating layer is formed between the surface of each component to which the coil 150 is coupled, and two electrode pads are provided on the upper surface of the substrate 110 to provide current to the coil 150. Can be.

Two portions of the first elastic body 144 connected to both ends of the first gamble 140 are connected to two electrode pads, respectively.

8 is a bottom perspective view showing the structure of a scanning micromirror 100 according to an embodiment of the present invention, Figure 9 is a bottom perspective view showing an enlarged view of the gamble structure of the scanning micromirror 100 according to an embodiment of the present invention. to be.

Referring to FIG. 8, the bottom surface of the substrate 110 is etched to form a first trench 180, and the above-described components 144, 140, 142, 130, and 132 are formed by the first trench 130. , 122, 124, and 120 may be formed, and the first trench 130 may provide a space in which the first gamble 140, the second gamble 130, and the mirror plate 120 may move.

Referring to FIG. 9, the second trench 182 and the third trench 184 are etched to thinly form the first elastic body 144 and the second elastic body 142, which is a first elastic body. This is to reduce the spring constant of the 144 and the second elastic body 142.

A magnet is coupled below the first trench 180 of the substrate 110, which will be described below.

10 is a diagram illustrating the basic driving principle of the magnet 160 and the coil 150 provided in the scanning micromirror 100 according to an embodiment of the present invention, and FIG. 11 is a scanning microcomputer according to an embodiment of the present invention. When the coil 150 of the mirror 100 is provided with two lines, it is a diagram illustrating the principle of biaxial driving, and FIG. 12 is a diagram illustrating the coil 150 of the scanning micromirror 100 according to an embodiment of the present invention. In the case of a line, it is a diagram illustrating a two-axis driving principle.

As described above, in order for the first gamble 140 and the second gamble 130 to flow about two axes by the force of Lorentz, the shape and arrangement of the magnet 160 are important. Forms a radial magnetic field outward from the center on the plane. Through this magnetic field shape, the two-axis drive can be best implemented.

First, referring to FIG. 10, the magnet 160 includes a large cylindrical magnet 166, a ring magnet 164, and a support 162, and the cylindrical magnet 166 is positioned inside the ring magnet 144. do.

The ring magnet 144 and the cylindrical magnet 166 has a space concentrically spaced, which is to ensure the space in which the electromagnetic field is formed, the ring magnet 164 and the cylindrical magnet 166 is the same thickness and the support 162 is coupled to the top surface.

In order to maximize the radial magnetic field, the ring magnet 164 and the cylindrical magnet 166 are magnetized in opposite directions, and the support 162 may be made of a material such as pure iron having a high relative permeability. .

Referring to FIG. 10, on the substrate 110 (that is, the mirror plate 120, the first elastic body 144, the first gamble 140, the second elastic body 142, the second gamble 130, and the third elastic body) The shape of the coil 150 formed on the mirror plate 120 is illustrated above the magnet 160, and the coil 150 is disposed concentrically with respect to the center of the cylindrical magnet 166. .

First, when the current 2I flows through the first electrode pad (one side of the first elastic body 144), the current 2I is branched from the circular coil and simultaneously proceeds in both directions. 2 electrode pads (the other side of the first elastic body 144) are combined and flow out.

In this way, when the same amount of current (I) of the line symmetry flows on the coil 150, they are subjected to the vertical force (F) by the radial magnetic field (H _r ), which is represented by the following equation (1) The torque T is applied.

Here, "r ₁ " means the radius of the circular coil,

"μ" means permeability of air,

"H _r " means Radial Magnetic Field Intensity.

Therefore, independent torques (T _vertical and T _horizontal ) are provided with respect to two rotation shafts orthogonal to each other (the rotation shaft formed by the second elastic body 142 and the third elastic body 132 and the rotation shaft formed by the first elastic body 144). To do this, two coils 150 are electrically separated as shown in FIG. 11.

Referring to FIG. 11, a circular coil 150 having a large diameter at the bottom thereof is a portion coupled to the first gamble 140, and a circular coil 150 having a relatively small diameter at the top thereof is coupled to the second gimbal 130. In this case, the current I _v flowing in the lower coil and the current I _h flowing upward are used independently for driving the vertical axis and the horizontal axis.

However, instead of using an electrically separated coil 190 as shown in FIG. 11, but using one coil 150 line as shown in FIG. 12, the winding structure may be changed to allow torque in two axial directions. Can be.

At this time, since the current flows in the opposite direction to the portion where the upper coil and the lower coil are connected, no force is applied, and in the two parallel windings passing through the center of the upper coil, a horizontal force rather than a torque is theoretically applied. Done.

Thus, if two coils (upper circular coil and lower circular coil of FIG. 12) disposed in the first gamble 140 and the second gamble 130 are formed through one coil line, unlike one in FIG. There must be an input stage and an output stage, and the same current (I _v ) flows in the two portions, so that independent control of torque applied in the vertical and horizontal directions is impossible.

However, different structures of the winding supporting structure, that is, the first gamble 140, the second gamble 130, the mirror plate 120, and the elastic bodies 144, 142, and 132 may be independently distributed. Two-axis drive can be implemented, and in this case, the structure of the scanning micromirror 100 can be simplified and the manufacturing process is reduced, thereby reducing the manufacturing cost.

Therefore, in the embodiment of the present invention, it is assumed that the winding structure shown in FIG. 12 is used, and the coil structure shown in FIG. 12 is three-dimensionally illustrated to explain the principle, and is actually disposed on a plane.

13 is a plan view showing a structure in which the coil 150 of the scanning micromirror 100 according to the embodiment of the present invention is disposed on the first gamble 140, the second gamble 130, and the mirror plate 120. to be.

Referring to FIG. 13, the coil 150 is formed of one patterned metal layer, and the path of current is explained as follows.

When a current is supplied to the first elastic body 144 connected to one side of the first gamble 140, the current flows branched from both sides of the circular coil of the first gamble 140.

The current branched to both sides enters the circular coil on the second gamble 130 through the second elastic bodies 142 on both sides, and the coil 150 on the second gamble 130 and the mirror plate 120 is semicircular. Two parts of the coil are formed opposite each other.

The current entered through the second elastic body 142 on one side flows along the semicircular coil (second gamble 130) on one side and passes through the mirror plate 120, and then again the second elastic body 142 on the one side. To reach.

Meanwhile, the current entered through the second elastic body 142 on the other side flows through the mirror plate 120 (that is, two coil lines penetrate the mirror plate 120), and the semicircular coil on the other side (second After flowing along the gamble 130, the second elastic body 142 is approached again.

The current reaching the second elastic body 142 on the one side and the second elastic body 142 on the other side flows through the remaining sections of the first gamble 140, respectively, and is joined to the other side of the first gamble 140. It is output to the first elastic body 144.

Here, the current flowing through the coils (which are two coil lines arranged in parallel) on the first gamble 140, the second gamble 130, and the mirror plate 120 may include the second elastic body 142 and the third elastic body ( 132) as an axis, the upper part and the lower part flow in the same direction, that is, linearly symmetric with respect to the axis.

The coil structure implemented as one line through the structure is radially identical to the structure of the coil 150 implemented as individual lines according to the first gamble 140, the second gamble 130, and the mirror plate 120. Can form a magnetic field.

14 is a diagram illustrating a simulation result of the resonance mode of the scanning micromirror 100 according to the first embodiment of the present invention by finite element analysis.

Figure 14 (a) is a simulation of the first resonance mode, (b) is a simulation of the fourth resonance mode, (c) is a simulation of the sixth resonance mode, (d) The seventh resonance mode is simulated.

The two-axis drive according to the present invention is a drive for rotating the first elastic body 144 to the axis (A-A 'axis), and the second elastic body 142 and the third elastic body 132 to the axis (B-B' axis) Is implemented by a combination of driving rotations, and the resonance modes are classified according to these combinations.

Among these, the driving modes related to the two-axis driving are the first resonant mode, the fourth resonant mode, the sixth resonant mode, and the seventh resonant mode as shown in FIG. 14, and in particular, the scanning micromirror 100 according to the present invention is In the seventh resonance mode, the mirror plate 120 is driven with a significantly amplified angular displacement.

In the first resonant mode illustrated in FIG. 14A, each component including the first gimbal 140, the second gimbal 130, and the mirror plate 120 includes the axis of the first elastic body 144. A ') and rotates (referred to as "force mode" by reference).

In the fourth resonance mode illustrated in FIG. 14B, each component including the first gamble 140, the second gamble 130, and the mirror plate 120 includes a second elastic body 142 and a third elastic body ( 132 is a mode in which the axis B-B 'is rotated. (C) In the sixth resonance mode shown in the drawing, each component part includes the second elastic body 142 and the third elastic body 132. B ') is rotated but the rotation direction of the first gamble 140 and the second gamble 130 is in the opposite direction.

In addition, in the seventh resonance mode illustrated in FIG. 14D, each component portion is rotated using the second elastic body 142 and the third elastic body 132 as the axis B-B ', and the mirror plate 120 is rotated. ) And the first gamble 140 are rotated in the same direction, and the second gamble 130 is a driving mode that rotates in the opposite direction.

When the direction of rotation of the mirror plate 120 and the second gamble 130 is in the opposite direction, it is generally referred to as "resonant mode".

The above-described resonance modes can be shifted according to the shape, density, modulus of elasticity, and spring constant of each component of the scanning micromirror 100, and can change the transition order and resonance frequency of each resonance mode. have.

As mentioned above, the scanning micromirror 100 according to the present invention exhibits key driving characteristics in the seventh resonance mode, and is applied to the mirror plate 120, the first gamble 140, and the second gamble 130. Depending on factors such as the corresponding inertia ratio, spring constant ratio of the third elastic body 132 and the first elastic body 142, the angle of rotation of the mirror plate 120 in the seventh resonance mode may be significantly increased. Can be.

According to the present invention, it is preferable to implement the resonant drive using the B-B 'axis as the rotation axis during the two-axis drive, and operate the scanning micromirror 100 through the forced drive when the A-A' axis is the rotation axis. Can be.

In particular, the seventh resonant mode is used to realize two-axis driving with a coil arrangement structure of one line like the scanning micromirror 100 according to the present invention, which includes two driving bands separated in two rotation directions. This is possible by applying a frequency signal to the coil 150.

15 is a graph illustrating frequency waveforms of resonance modes of the scanning micromirror 100 according to an exemplary embodiment of the present invention.

FIG. 15A is a waveform of a current input in the first resonance mode (hereinafter referred to as “f1”), and (b) a diagram of a frequency of a current input in the seventh resonance mode (hereinafter, referred to as “f7”. Waveform, and (c) the measurement of the frequency wave when the f1 current and the f7 current are combined.

When the frequency of the current applied in the fourth resonant mode is "f4", when the current f1 and f7 are simultaneously applied to the coil 150, the current of f1 is applied to the path of the coil 150 on the first gamble 140. It acts effectively to induce driving of the first resonant mode, and the current of f7 acts effectively in the path of the coil 150 on the second gimbal 130 to induce driving of the seventh resonance mode.

The first resonant mode is a drive for scanning in the vertical direction of the screen and is forcibly driven at a frequency speed of several tens of Hz (scanned light is scanned) (for example, 60 Hz for a 60-frame image), and the seventh resonant mode. Is a resonant drive at a frequency rate of several tens of kHz as a scan for the horizontal direction of the screen (e.g., in the case of 60 frames of image, the frequency frequency in the vertical direction is the frequency speed in the horizontal direction x 60 ÷ 2). With a frequency speed of about 19 kHz).

When a current of a frequency band significantly lower than f1 is applied, a resonance mode corresponding to a frequency band significantly lower than f1 is forcibly driven instead of the first resonance mode, and the driving direction thereof is the same as that of the first resonance mode.

As such, the frequency of the current is selected so that the resonance modes for the two drive shafts are properly formed, and the shape of the structure such as the magnet 160 should also be designed in accordance with the electromagnetic phenomenon. ), The mirror plate 120, the elastic body 144, 142, 132, etc., the arrangement of the coil 150 should be efficiently designed so that the driving force can be transmitted well.

As described with reference to FIG. 13, the arrangement of the coils 150 for two-axis driving may apply various arrangement methods in addition to a method of using one winding connected in series.

Hereinafter, various arrangement structures of the coil 150 will be described.

16 is a top view illustrating a structure in which the coil 150 of the scanning micromirror 100 is single-layer wound to three input / output lines according to an embodiment of the present invention, and FIG. 17 is a scanning microcomputer according to an embodiment of the present invention. The coil 150 of the mirror 100 is a top view showing a structure in which two layers are wound by two input / output lines.

Referring to FIG. 16, a total of three coils 150a, 150b, and 150c lines are disposed, and a coil portion for driving the first gamble 140 and a coil portion for driving the second gamble 130 are separated. In this case, the coil part for driving the first gamble 140 may be separated into two parts.

That is, the first coil line 150a enters the first elastic body 144 on one side, forms a left semicircular path of the first gamble 140, and then goes out to the first elastic body 144 on the other side, and the third coil line 150c. ) Enters the first elastic body 144 on one side, forms a right semicircular path of the first gamble 140, and exits to the first elastic body 144 on the other side.

In addition, the second coil line 150b constitutes a path of the first gamble 140 from the first elastic body 144 on one side to the second elastic body 142 on the one side, and through the second elastic body 142 on the one side. A circular line on the second gamble 130 is formed.

That is, the current input from the second elastic body 142 on one side flows branched into the upper semi-circular line and the lower semi-circular line of the second gimbal 130, and is output through the second elastic body 142 on the other side to be made of the other side. It flows to the one elastic body 144 side.

Meanwhile, referring to FIG. 17, a total of two coil lines 150a and 150b are disposed, the coil part 150a for driving the first gamble 140 and the coil part for driving the second gamble 150b. 150b is separated.

The arrangement structure illustrated in FIG. 17 is different from the arrangement structure described with reference to FIG. 16, in which the first coil 150a and the third coil 150c are formed as a single line without being separated, and share input / output lines. In order to share the input / output line (that is, form a circular line), the second coil 150b connected to the second gamble 130 is insulated and connected to the upper (or lower) layer.

Thus, it can be seen that two metal layers are used which are substantially insulated.

Although the present invention has been described above with reference to the embodiments, these are only examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains may have an abnormality within the scope not departing from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not illustrated. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

According to the scanning micromirror according to the present invention, the following effects are obtained.

First, a lighter and smaller scanning micromirror can be implemented by applying semiconductor integrated process and micromachining technology, and thus, an optical scanning device in which the micromirror is integrated can be manufactured.

Second, the optical speed is improved by increasing the irradiation speed and the range of the irradiation angle is wider, and there is an effect that can prevent physical deformation due to the high speed operation through the structural improvement, and modulates the path of the reflected light by a predetermined amount Modulation or each modulation function can be provided.

Third, the micromirror can be manufactured through micromachining technology and semiconductor process without conventional substrate bonding or high precision alignment process, which simplifies the process, reduces the production cost, and can drive the optical scanning device with less voltage. It works.

Claims (9)

A substrate on which an open area is formed; A ring-shaped first gimbal coupled to the substrate on the open area through a first elastic body and driven with the first elastic body as a rotation axis; A ring-shaped second gimbal coupled to the inside of the first gimbal through a second elastic body and driven using the second elastic body as a rotating shaft; A mirror plate coupled to the inside of the second gamble through a third elastic body and driven using the first elastic body, the second elastic body, and the third elastic body as a rotating shaft; A coil coupled to the elastic body, the gimbal, and the mirror plate to form an electromagnetic field to generate a driving force; And And a magnet coupled to the bottom surface side of the substrate and forming an electromagnetic field together with the coil. The method of claim 1, The mirror is positioned between the mirror plate and the second gamble, and is connected to the mirror plate through a plurality of connecting bodies, and is connected to the second gamble through the third elastic body, thereby making the mirror the third elastic body as the rotation axis. Scanning micromirror comprising a reinforcement frame driven with the plate. The method of claim 1, The second elastic body and the third elastic body is located on a straight line to provide a rotation axis of the second gamble and the mirror plate, The first elastic body is a scanning micromirror, characterized in that it is positioned perpendicular to the rotation axis of the second elastic body and the third elastic body to provide a rotation axis of the first gamble. The method of claim 1, wherein the elastic body It consists of one or more torsion bars, The torsion bar is scanning micromirror, characterized in that the combination of one or more of the straight or curved form. The method of claim 1, wherein the magnet is Ring magnets; Cylindrical magnets spaced apart from inside the ring magnet; And Scanning micromirror comprising a support for coupling the ring-shaped magnet and the cylindrical magnet on the bottom side. The method of claim 1, When a low frequency first frequency signal is applied to the coil, the first gamble, the second gamble, and the mirror plate are forcibly driven based on the rotation axis of the first elastic body. And a high frequency second frequency signal is applied to the coil, wherein the second gamble and the mirror plate are resonantly driven with respect to rotation axes of the second elastic body and the third elastic body. The method of claim 1, The elastic body is composed of two parts each located opposite each other, The coil has a single wire structure and a single layer structure, and constitutes a first gimbal path from one side of the first elastic body to one side of the second elastic body, and forms one side semicircular path of the second gimbal, and then from the other side of the second elastic body to the one side of the second elastic body. A first coil part penetrating through a mirror plate and constituting a first gamble path from the second elastic body on one side to the first elastic body on the other side; And constructing a first gamble path from the first elastic body to the other second elastic body, penetrating the mirror plate from the second elastic body to the second elastic body, and configuring the other half-circle path of the second gimbal. And a second coil part constituting a first gamble path from the other second elastic body to the other first elastic body. The method of claim 1, The elastic body is composed of two parts each located opposite each other, The coil has a double wire and a multilayer structure, the first coil part branching from an input line of one side of the first elastic body to form a circular path on the first gimbal and forming an output line of the other side of the first elastic body; And the first coil part is insulated from the first elastic body and enters the second gimbal through one side second elastic body, forms a circular path on the second gimbal, and then passes the other first elastic body through the other second elastic body. Scanning micromirror comprising a second coil portion for forming an output line with an elastic body. The method of claim 1, The elastic body is composed of two parts that are located opposite each other, The coil has a double wire and a single layer structure, and includes a first coil part and a second coil part constituting a semicircular path in both directions on the first gamble from one side of the first elastic body to the other side of the first elastic body; And a second entry into the second gimbal from the first elastic body on one side through the second elastic body, and form a circular path on the second gimbal, and then form an output line to the other first elastic body through the second elastic body on the other side. Scanning micromirror comprising a coil portion.

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