KR100270813B1 - Movable micro mirror for a video display apparatus - Google Patents

Abstract

PURPOSE: A moving micro mirror for an image display device is provided to prevent strength and elasticity weakness by connecting a pillar member to a pin member without connection to a center electrode. CONSTITUTION: An electrode(102) consisting of center, right and left electrodes is formed on a substrate(100). A staple member(106) is installed at the center electrode of the electrode(120) so as to be supported by a support(110). The staple(106) supports a pin member(104) so as to be rotated. The pin member(104) is integrated with a reflector(108), which has a top surface as a reflection surface and a bottom surface as a contact surface to be contact with the center electrode. The reflector(108) is connected to the pin member(104) and is horizontally floated toward an upper direction of the substrate(100).

Description

Movable Micro Mirror for Image Display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable type micromirror for an image display device. In particular, the movable type for an image display device having an axis of rotational movement in which the projection direction of an image changes as the reflecting surface contacts left and right with an axis pinned to be movable left and right Relates to a micro mirror.

A key component of the micromirrors constituting the image display apparatus is a micromirror array chip that displays an image by reflecting light pixel by pixel. Currently, micromirror array chips are known as electrostatically driven micromirrors and piezoelectrically driven micromirrors.

Hereinafter, the electrostatically-driven micromirror array chip, in particular, the movable micromirror will be described.

A movable micro mirror array chip is produced by arranging mirrors two-dimensionally by the number of pixels, and reflecting each mirror according to a signal of a pixel of an image to adjust color and brightness. Such a mirror is separated from the substrate 10 by the reflector 18 and the reflector 18 which form a reflecting surface for reflecting light, as shown in FIGS. 1 (a) and 1 (b) of the accompanying drawings. It is composed of a pillar member 12 for supporting the reflector 18, a reflector 18 and the pillar member 12, and a flexure hinge 14 inclined with elastic force. . The lower surface of each mirror includes a driver for driving the mirror and a drive circuit for controlling the drive signal.

A movable micro mirror for an image display device having such a structure is disclosed in US Pat. No. 5,083,857.

The movable micromirror for an image display apparatus known by this patent publication operates as follows.

That is, when voltage is applied to the electrode fabricated below the reflector, that is, on the substrate, and a potential difference is generated between the reflector and the electrode, electrostatic attraction occurs, and torque is generated to pull the reflector toward the electrode to rotate the flexure hinge about its axis. If this torque value is greater than the restoring force by the torsion spring of the flexure hinge, the reflector is tilted. If this value is greater than a certain threshold, the reflector continues to tilt and touch the substrate. At this time, when the reflected light enters the screen, the switch is on, and when the light is inclined to the opposite side, the switch is turned off. The brightness and color are controlled by adjusting the on / off state of the switch. This is called a digital method.

2 (a) and 2 (b) in the accompanying drawings are structures having a pivoting hinge structure bearing the staple shaft portion.

A conventionally known hinge type structure according to this figure is as follows.

That is, a staple (hereinafter referred to as a bearing member) 24 formed on the substrate, a pin member 26 supported by the bearing member 24 to be rotatable while being supported on the substrate, and at the pin member 26. It extends in a horizontal state consists of a structure 28 that rotates with the pin member.

The movable micromirror having the flexure hinge of the torsional rotation causes the flexure hinge portion that connects the reflector of the rigid body to the substrate to be twisted or bent, so that the fatigue phenomenon of the flexure hinge limits the life of the device. The flexure hinge has a thin thickness of 0.1 μm, which moves the micromirror, and it is only natural that the life span is shortened because elastic deformation is performed about 21 billion times when the life of the image display device is assumed to be 5 years. Therefore, there has been a demand for improvement.

Therefore, it is necessary to fundamentally change the torsion structure of the flexure hinge and to fundamentally correct the fatigue phenomenon of the hinge as the flexure hinge portion connecting the reflector and the substrate is twisted or bent.

The present invention seeks to improve the structural problem of such a joint structure of a conventional movable micro mirror for image display.

That is, the present invention provides a hinged micromirror based on the principle of rotation without a shaft structure in which a flexure hinge portion connecting the reflector and the substrate is twisted or bent, such as a movable micromirror having a flexure hinge of torsional rotation.

In particular, in the hinge structure, the reflector is freely expandable, and the hinge part is intended to provide an extended rotation structure of the micromirror having a hinge structure that allows precise operation by the rotational force.

Figure 1 (a) is an exploded perspective view of a conventionally known micro mirror.

Fig. 1 (b) is an assembled sectional view of Fig. 1 (a).

Figure 2 (a) is a perspective view of a structure having a conventional pivoting hinge structure.

(B) is sectional drawing of FIG.

Figure 3 is a perspective view of one embodiment of the present invention.

4 is a perspective view of another embodiment of the present invention.

5 is a cross-sectional view of FIG. 4.

Fig. 6 is a schematic cross-sectional view showing the present invention's turning action.

Figure 7 is a partially enlarged perspective view of the present invention when the plurality of bearing members are implemented.

8 is a partially enlarged perspective view of another embodiment of the water bearing member of the present invention.

9A to 9E are schematic side views of various embodiments of the present pin member.

10A to 10B are schematic plan views of various embodiments of the present pin member.

※ Explanation of symbols for main parts of drawing

100: substrate ... 102: electrode

104: pin member .. 106: bearing member

108: Reflector ..... 110: Stand

200: substrate ...... 202: electrode

204: pin member .. 206: bearing member

208: Reflector .... 210: pillar member

In order to achieve the above object, the present invention provides a micromirror for an image display apparatus in which a hinge portion and a reflector are formed on an electrode formed on a substrate to generate an electrostatic attraction around the hinge portion to achieve image reflection. Fin members protruding to both sides to form a hinge axis; A bearing member configured to rotatably hold the pin member; And a reflector connected to the pin member and floating horizontally with a predetermined gap above the substrate, the movable micromirror structure for an image display device in which the pin member is rotated.

A plurality of the bearing members having such a feature may be installed at the same time. In addition, the bearing member preferably forms a sufficient gap so that the pin member of the rectangular cross section in the inner space is rotatable, one end of the side is blocked and the other end is opened to prevent the axial flow of the pin member. Do.

The pin member is preferably carried out in a circular, semi-circular cross-section to increase the precision of the rotational force. In addition, the both edge portions of the pin member and the corresponding portions of the substrate correspond to the uneven portions to widen the rotation thereof.

In particular, in the present invention, by forming a vertical pillar member between the fin member and the reflector, the reflecting area of the reflector can be freely designed to a sufficient size, in which case the reflector pivoting left and right by electrostatic attraction has a restoring force in a specific direction. The position on the substrate of the vertical center point can be freely designed.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 of the accompanying drawings is a perspective view of an embodiment of the present invention, at least three electrodes forming a center electrode and a left and right electrodes on the substrate 100 having an insulating layer as a whole based on a silicon wafer. 102 is formed. The center electrode of the electrode 102 is provided with a bearing member (Staple) 106 supported by the pedestal 110, the bearing member 106 is rotatably supporting the pin member (Pin) 104 to be described later do.

The fin member 104 is formed integrally with the reflector 108, but is a protruding pin that is integrally attached to the bottom half of the reflector 108 with the separate fins horizontally or protrudes on both sides of the reflector 108. It can be carried out. The reflector 108 has a top surface as a reflecting surface and forms a contact surface through which electricity is applied by contacting a center electrode formed on the substrate 100 on the bottom surface thereof, and is connected to the pin member 104 to provide a predetermined gap upwardly above the substrate 100. Left horizontally.

Such a pin member 104 and the bearing member 106 realize a hinge function by the combination thereof.

In addition, this invention can be implemented as shown in FIG. FIG. 5 is a cross sectional view of FIG. 4, in which at least three electrodes 202 are formed on the substrate 200. The bearing member 206 is connected to one of the center electrodes of the electrode 202, and the pin member 204 is formed to be rotatably supported by the bearing member 206. The pillar member 210 is formed above the pin member 204. The pillar member 210 floats above the left and right electrodes 202 upward and forms a reflector 208 on which the upper surface forms a reflective surface. The reflector 208 of the fin member 204 as described above forms a center of gravity so as to retract when tilted left and right in a state supported by the bearing member 206.

6 is a schematic cross-sectional view showing the rotational effect of the present invention. According to this figure, the restoring force varies depending on the position on the pin member 204 of the reflector 108 which rotates left and right with electrostatic attraction.

The pillar member 210 formed between the pin member 204 and the reflector 208 may be implemented in one or more to correspond to the extension of the length of the pin member 204. 7 shows a case where a plurality of water bearing members of the present invention are implemented.

As described above, the bearing members 106 and 206 of the present invention extend in the front-to-rear direction in the form in which both ends are cut, and protrude as high as the central portion thereof to form an inner space.

Therefore, the pin members 104 and 204 are placed on the inner bottom surface of the fusion portion. 8 is a view illustrating a state in which the water-retaining member of the present invention is closed differently as one end of both ends. Therefore, in this case, both ends of the pin members 104 and 204 are blocked to prevent the left and right flow.

9A to 9E illustrate various cross-sectional structures of the pin member when the pin member and the pillar member 210 of the present invention are connected.

That is, the pin members 104 and 204 of Fig. 9A show rectangular cross sections applied to all the pin members shown in Figs. The pin members 104 and 204 have a circular cross section as shown in Fig. 9 (b), a semicircular cross section as shown in Figs. 9 (e) shows the pin member of the triangular cross section.

10A to 10C are schematic plan views in the case where the plate-shaped pin member of the present invention cross section is shown in various embodiments, and FIG. 10A is a pin member 104 and 204. The opposite edges of the substrate 100 and the corresponding portions of the substrate 100 correspond to the uneven portions. In the case of the pin members 104 and 204, the corner portions are axially movable so that they can only move to the upper portions of the rectangular cross sections in common. The range of rotation is limited and it has the ability to expand even below.

In the movable micromirror of the present invention, a bearing member is connected to a central electrode of at least three electrodes formed on the substrate, and a fin member is formed to be rotatable by the bearing member. While maintaining the level from above, the electrostatic attraction is generated by the potential difference generated from the left and right electrodes on the substrate, and thus has an action of being attracted to the electrode side. At this time, conventionally, the elastic member for rotation reversal is generated in the reflector because it has a flexure hinge or a bullet type connection portion instead of the pin member, but in the present invention, one side of the pin member becomes an axis and the other side is raised so that the center of gravity is easily lowered. do. There is no need for elasticity in particular. In particular, the principle of restoration by the center of gravity exerts an effective restoring force even when the reflector is separated from the pin member and connected as a pillar member.

Therefore, when the flexure hinge portion connecting the reflector and the substrate is twisted or bent, such as a movable micromirror having a flexure hinge of a torsional rotation, the lifespan is not long due to fatigue caused by repeated elasticity. The latter provides a hinge structure of the rotational principle having the resilience by the center of gravity such as the latter.

At the same time, in the hinge structure, the reflector structure can be freely expanded while the hinge structure can be provided with a rotating structure of an extended movable micromirror that allows the hinge portion to be operated accurately by the rotational force.

As described above, the present invention is structurally the pillar member is connected to the pin member instead of independently connected to the center electrode and rotates on the basis of the center of gravity of the left and right flow, so that the movable structure connecting portion and the hinge portion of the conventional joint structure are independently the center electrode. As connected to the strength, there is an effect to improve the problem of elastic weakening.

In addition, as a movable micro mirror having a torsionally rotating flexure hinge, the flexure hinge portion connecting the reflector and the substrate is not a twisted or bent shaft structure, but a hinge structure in which the center of gravity is rotated to extend the life. At the same time, this pivoting hinge structure is not eccentric to one surface of the reflector but can be rotated to the left and right in half at its center, so that it can be rotated with less electrostatic attraction than the latter.

In addition, since the hinge structure is connected to the pillar member, the area of the reflector can be freely expanded, and the hinge portion is accurately rotated so as to have an effective reflection angle.

Claims (15)

In the movable micro mirror for an image display device, A reflector floating horizontally above the substrate to receive electrostatic attraction from the electrode; Fin members extending from both sides of the reflector; And And a bearing member for enclosing and supporting an end portion of the reflector so as to be rotatable when the reflector rotates left and right. 2. The movable micromirror for an image display apparatus according to claim 1, wherein said bearing member is at least one. The movable micro-mirror for an image display apparatus according to claim 1, wherein the pin member has a restoring force after the left and right rotation in the inner space of the bearing member. 2. The movable micromirror for an image display apparatus according to claim 1, wherein the bearing member has a cover structure on an outer surface to prevent axial movement of the pin member. 2. The movable micromirror of claim 1, wherein the pin member has a rectangular cross section. 2. The movable micromirror for an image display apparatus according to claim 1, wherein said pin member has an arcuate curved surface with a bottom contact portion having a cross-sectional shape. 2. The movable micromirror for an image display apparatus according to claim 1, wherein at least one fin member extends from the reflector. In the movable micro mirror for arrow apparatus, A reflector floating horizontally above the substrate to receive electrostatic attraction from the electrode; A pillar member vertically extending downward from the bottom of the reflector; Pin members extending from both sides of the lower end of the pillar member; And And a bearing member for enclosing and supporting an end portion of the reflector so as to be rotatable when the reflector rotates left and right. 9. The movable micromirror for an image display apparatus according to claim 8, wherein said bearing member is at least one. 9. The movable micromirror for an image display apparatus according to claim 8, wherein the bearing member blocks an outer surface to prevent axial movement of the pin member. 9. The movable micromirror for an image display apparatus according to claim 8, wherein the pin member has a restoring force after left and right pivoting in an inner space of the bearing member. 12. The movable micromirror for an image display apparatus according to claim 11, wherein the center of gravity of the pillar member is formed below the pillar member rather than the reflector. 9. The movable micromirror for an image display apparatus according to claim 8, wherein the pin member has a rectangular cross section. The movable micromirror for an image display apparatus according to claim 1, wherein at least one pin member is provided. 9. The movable micromirror for an image display apparatus according to claim 8, wherein said pin member has an arcuate curved surface with a bottom contact portion having a cross-sectional shape.

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