KR102331643B1 - Scanning micromirror - Google Patents

Abstract

The present invention provides a main body including a front side, a rear side and a side surface, a display unit mounted on the front side and outputting screen information, and an overlapping area overlapped with the display unit to be reciprocally movable along one direction on the display unit. and a speaker module mounted on the main body and a controller for moving the speaker module based on output state information of the screen information.

Description

Scanning Micromirror

The present invention relates to a scanning micromirror including a dummy coil.

With the development of optical device technology, various technologies using light as input/output terminals of various information and as a medium for information transmission are emerging. As such technologies, there is a technology that scans and uses a beam emitted from a light source, such as a barcode scanner or a basic level scanning laser display.

In particular, recently, a system using high spatial resolution beam scanning has been developed, and such a system includes a high-resolution, high-resolution primary color reproduction using laser scanning, a projection-type display system, a head mounted display (HMD), and a laser printers, etc.

This beam scanning technology requires a scanning micromirror having various scanning speeds and scanning ranges, that is, various angular displacements and tilting angles depending on application cases. Existing beam scanning is driven using a galvanic mirror or a rotating polygon mirror, and is implemented by adjusting the angle of incidence between the reflective surface of the mirror and the incident light.

Such a scanning micromirror is a MEMS device mainly used for a display and a range finder/Lidar. The scanning micromirror is a driving element capable of spatially modulating an optical path, and a driving force can be obtained through various methods.

As a method for obtaining the driving force, there is a method using an electrostatic force, an electromagnetic force, and a piezoelectric force. In general, a scanning micromirror using electromagnetic force obtains a driving force by using the Lorentz force generated when a current flows through a coil formed on an element located in a magnetic field created by a permanent magnet.

The driving shaft of such a scanning micromirror consists of an X-axis and a Y-axis, and the rotation of the X-axis corresponds to a low-speed scan in the vertical direction and generally determines the number of frames of the display. Y-axis rotation corresponds to a high-speed scan in the horizontal direction and usually determines the display resolution. The X-axis rotation is forcibly driven at a speed of about 60 Hz, and the Y-axis rotation is resonantly driven in the range of about 19 kHz to 44 kHz depending on the resolution. Various motion resonance modes are formed by the physical structure of the scanning micromirror element. About 6 resonance modes before about 18 kHz and about 9 resonance modes before about 28k may be formed.

When these modes occur during mirror driving, various types of image quality degradation occur. As the driving frequency increases, more modes exist and are more likely to operate. Such abnormal behavior can be reduced by maintaining higher precision in device manufacturing process tolerances, but higher precision means lower yield and is accompanied by higher manufacturing cost.

In order to increase the horizontal resonant frequency of the scanning micromirror, it is necessary to reduce the moment of inertia. Since the size of the mirror must be increased to increase the resolution, it is desirable to reduce the thickness of the device in order to reduce the moment of inertia. Accordingly, the scanning micromirror includes a silicon structure formed symmetrically with respect to an operating axis, and a winding portion formed asymmetrically on the silicon structure and made of a plated metal. As the silicon structure gradually becomes thinner, the influence of the windings formed asymmetrically during the rotation of the scanning micromirror increases.

Due to the asymmetric structure of the winding part, a driving force is generated in a direction deviating from a preset driving shaft, so that more modes are operated.

Accordingly, an object of the present invention is to provide a scanning micromirror with improved yield by preventing asymmetric rotation.

In order to achieve the above object of the present invention, a scanning micromirror according to an embodiment of the present invention includes a winding and a magnet formed on one surface of an outer gimble and an inner gimble to form an electromagnetic field to generate a driving force, and the and a dummy winding portion formed in an area where windings are not arranged. The dummy winding part and the winding are formed to be symmetrical with respect to the rotation axis of the scanning microphone mirror.

According to an embodiment of the present invention, in order to implement symmetrical rotation, a second winding part formed in some of the first to fourth regions and a dummy winding part formed in the other of the first to fourth regions are included. In addition, the mass of the dummy winding portion may be formed to be substantially the same as the mass of the second winding portion formed in the partial region, and the shape thereof may be the same.

According to an embodiment of the present invention, the winding is formed on one surface of the outer gimble and at least a portion of the dummy winding portion is formed on the other surface of the outer gimble in order to prevent a driving error due to the movement of current to the dummy winding portion. .

According to the present invention, by forming at least one dummy winding part in a region of the outer gimble where the winding part is not formed, it is possible to balance the scanning micromirror.

The mass of the dummy winding portion formed in one region may be substantially the same as the mass of the winding portion formed in the remaining region corresponding to the one region, and the dummy winding portion and one region of the winding portion may have substantially the same shape. Accordingly, when the scanning micromirror rotates in the X and Y axes, it is possible to solve the problem of asymmetry in which the rotation axis is changed.

In addition, the winding part is formed on one surface of the gimble, at least a part of the dummy winding part is formed on the other surface of the gimble, and a part of the dummy winding part formed on the other surface is disposed closer to the second elastic body and a part of the dummy winding part formed on the one surface. . Accordingly, since the contact between the winding portion and the dummy winding portion is cut off, a problem in which current flows through the dummy winding portion can be prevented.

1 is a view of a scanning micromirror viewed from one direction according to an embodiment of the present invention.
2A and 2B are conceptual views for explaining an arrangement structure of a winding unit according to an embodiment;
3A and 3B are perspective views of FIG. 2B taken in a first axial direction as viewed from one direction;
3C is a conceptual diagram for explaining an arrangement structure of a dummy winding unit according to another embodiment;
4 is a plan view illustrating an arrangement of a winding unit according to another embodiment;
5A and 5B are plan views illustrating an arrangement of a winding unit according to another embodiment;

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and overlapping descriptions thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and should not be construed as limiting the technical spirit disclosed herein by the accompanying drawings.

The technology disclosed herein relates to an optical scanning device that modulates a path of reflected light by applying a predetermined current to actuate a micromirror that reflects input light. In addition, the scanning micromirror according to the embodiments disclosed herein is configured to form information such as an image by scanning a beam emitted from a light source in a one-dimensional (line) or two-dimensional (plane) predetermined area. do. Accordingly, the scanning micromirror of the present invention can be applied to a laser printer that reads data such as position and image, a confocal microscope, a barcode scanner, a scanning display, and various sensors. In addition to scanning, it can also be applied to an optical switch device that arbitrarily adjusts the path of reflected light.

However, the technology disclosed in the present specification is not limited thereto, and may be applied to all application fields such as all optical scanning devices, devices, and optical scanning methods to which the technical idea of the above technology can be applied.

1 is a perspective view of a scanning micromirror according to an embodiment of the present invention.

Referring to FIG. 1 , the scanning micromirror according to this embodiment includes a mirror plate 51 that reflects light, a third elastic body 52 , a fourth elastic body 54 , a fifth elastic body 56 , and an inner gimble 53 . ), an outer gimble 55, a winding unit (not shown), a magnetic body (not shown), and a control unit (not shown).

The mirror plate 51 is formed to reflect light, and the third elastic body 52 is provided around the mirror plate 51 and is connected to the inner gimble 53 . The outer gimble 55 is formed to surround the inner gimble 53 , and the fourth elastic body 54 elastically connects the outer gimble 55 and the inner gimble 53 . The outer gimble 55 is connected to the support part 57 . The fifth elastic body 56 connects the outer gimble 55 and the support part 57 . The support part 57 supports the outer gimble 55 when the outer gimble 55 is twisted about the fifth elastic body 56 as an axis. That is, the support part 57 supports the outer gimble 55 while the outer gimble 55 rotates.

The scanning micromirror 50 is provided in the inner gimble 53 and the outer gimble 55, and a winding part (not shown) through which current flows and a magnetic material (not shown) forming a magnetic field around the winding part (not shown). city) is further included. The winding part may be formed of a metal such as Ti, Cr, Cu, Au, Ag, Ni, Al, or indume tin oxide (ITO), a conductive polymer, or a combination thereof.

The winding part (not shown) may also be formed on the mirror plate 51 .

The scanning micromirror 50 transmits a current flowing through the winding unit (not shown) so that the mirror plate 51 and the inner gimble 53 rotate out of phase with each other about the third elastic body 52 as an axis. Control. In addition, the scanning micromirror 50 controls the outer gimble 55 to rotate the fifth elastic body 56 about its axis. The control unit controls the frequency, direction, magnitude, etc. of the current flowing in the winding part, and receives the interaction of the magnetic field as an external force so that the mirror plate 51 and the inner and outer gimbals 53 and 55 are third , driven to rotate based on the fourth and fifth elastic bodies (52, 54, 56).

One area of the scanning micromirror 50 according to the present embodiment rotates based on at least some of the X-axis and the Y-axis that are perpendicular to each other.

2A and 2B are conceptual views for explaining an arrangement structure of a winding unit according to an exemplary embodiment. The scanning micromirror 50 includes first and second magnets 611 and 613 that radially form a magnetic field, a first winding portion 64 , and first and second dummy winding portions 71 and 72 . .

Although the inner gimble 53 and the outer gimble 55 are not shown in FIG. 2A , the first winding part 64 may be formed in at least one area of the outer gimble 55 and the inner gimble 53 . have.

1, 2A and 2B, the first winding portion 64 starts from one side of the support portion 57, passes through the fifth elastic body 56, and is a quadrant on the outer gimble 55. to form Next, the first winding portion 64 is branched into two winding portions at a point where it is connected to the inner gimble 53 through the fourth elastic body 54 . The two branched windings form two semicircles on the inner gimble 53 and again pass through the fourth elastic body 54 to form another quadrant on the outer gimble 55, and pass through the fifth elastic body 56 It extends to the other side of the support portion (57).

That is, the first winding unit 64 includes a first winding formed in four quadrants of the inner gimble 53 to form a circle, and a second winding formed in one region of the first to fourth quadrants. can

Although the drawing shows that the second winding is formed on the second and fourth quadrants among the first to fourth quadrants, the region where the second winding is formed is not limited thereto, and may be changed in design. have.

FIG. 2B is a plan view of the scanning micromirror in which the first winding portion 64 of FIG. 2A is formed.

Referring to FIGS. 2A and 2B , when a current 2I is applied to one side of the support part 57 , a current 2I flows in a quadrant formed on the outer gimble 55 . Since it is branched into two windings via the fourth elastic body 54 , a current I flows through each winding formed in the inner gimble 53 .

A current of 2I flows in a clockwise direction in the second quadrant of the outer gimble 55, and an I current flows in a counterclockwise direction in the second quadrant of the inner gimble 53, so that the I current flows clockwise in the second quadrant. It receives the same electromagnetic force that flows in the same direction. As in the present embodiment, the scanning micromirror having one winding unit may implement two-axis driving by varying the frequency of the driving current.

The inner gimble 53 and the outer gimble 55 of the scanning micromirror 50 according to the present invention may be made of an insulating silicon material. The winding part may be formed on one surface of the insulating silicon material. In addition, an insulating layer (not shown) may be formed under the winding portion to be electrically insulated from other components having a shape of the winding portion.

In order to reduce the moment of inertia of the scanning micromirror 50, in order to improve the resolution formed by the driving angle of the scanning micromirror 50 and the diameter of the mirror, it is preferable to increase the size of the mirror, and to increase the diameter of the mirror. It is preferable to reduce the thickness of the inner gimble 53 and the outer gimble 55 of the silicon material in order to reduce the increased moment of inertia.

In the scanning micromirror 50 according to the present invention, the first and second dummy winding portions 71 and 72 are formed on the outer gimble 55 made of silicon. In the first and second dummy winding portions 71 and 72 , the first winding portion 64 is not formed in the first to fourth regions of the outer gimble 55 corresponding to the first to fourth quadrants. It is formed in an area that does not

The first dummy winding portion 71 is formed in the first quadrant region of the outer gimble 55 where the first winding portion 64 is not formed. In addition, the second dummy winding portion 72 is formed in a third quadrant region of the outer gimble 55 . That is, the first and second dummy winding parts 71 and 72 are formed on the external gimble 55 where the first winding part 64 is not formed. The first and second dummy winding parts 71 and 72 may be made of substantially the same material as the first winding part 64 , and may be formed together with the first winding part 64 .

In addition, each of the first and second dummy winding portions 71 and 72 is formed to have substantially the same shape as one region of the first winding portion 64 disposed on the second and fourth quadrants. That is, the sum of the masses of the first and second dummy winding portions 71 and 72 is substantially equal to the sum of the masses of some of the first winding portions 64 on the second and fourth quadrants.

Referring to FIG. 2B , the first and second dummy winding parts 71 and 72 form a separation distance d so that the first winding part 64 does not come into contact with each other. In particular, the first dummy winding part 71 is formed to be spaced apart from the first winding part 64 formed on the fifth elastic body 56 . Accordingly, the movement of the current to the first and second dummy winding units 71 and 72 is blocked.

For example, masking is performed on the structure made of a silicon material of the scanning micromirror 50, and the first winding part 64 and the first and second dummy winding parts made of the metal material ( 71, 72) can be formed together. In this case, one region of the structure made of the silicon material is covered so that the metal material is not formed at the separation distance in the masking process.

According to the present invention, the scanning micromirror can be balanced by forming at least one dummy winding part in an area where one winding part formed in one of the inner gimble and the outer gimble is not formed.

3A and 3B are perspective views viewed from one direction of a cross-section taken in the first axial direction of FIG. 2B. Referring to FIG. 3A , the first dummy winding part 71 and the first winding part 64 are formed on substantially the same surface of the silicon material structure.

Meanwhile, referring to FIG. 3B , when the first winding portion 64 is formed on the first surface of the silicon material structure, the first dummy winding portion 71 is formed on the first surface of the silicon material structure. is formed on the second surface facing the That is, the first winding portion 64 and the first and second dummy winding portions 71 and 72 are formed on different surfaces of the structure.

According to the present embodiment, since the first and second dummy winding units 71 and 72 are cut off from contact with the first winding unit 64, it is possible to prevent a defect in which current flows through the dummy winding unit.

3C is a conceptual diagram illustrating an arrangement structure of a dummy winding unit according to another exemplary embodiment. The first dummy winding portion 71 of the scanning micromirror according to the present embodiment includes first and second metal members 71a and 71b, and the second dummy winding portion 72 includes third and fourth metal members 71a and 71b. made of metal members 72a and 72b. The first and second metal members 71a and 71b may correspond to shapes obtained by cutting the first dummy winding part 71 of FIG. 3A , but are not limited thereto.

The first winding part 64 is formed on the front surface of the scanning micromirror, and the first metal member 71a and the third metal member 72a are formed. The first and third metal members 71a and 72a are formed on the outer gimble 55 adjacent to the fourth elastic body 54 .

The second and fourth metal members 71b and 72b are formed on the rear surface. The second and fourth metal members 71b and 72b are formed in a region adjacent to the fifth elastic body 56 . The first and second metal members 71a and 71b are formed in separate regions so as not to overlap each other, and the third and fourth metal members 72a and 72b are formed so as not to overlap each other. The first to fourth metal members 71a, 71b, 72a, and 72b are uniformly disposed on the outer gimble 55 on the scanning micromirror.

According to this embodiment, it is possible to block the contact between the winding portion on the fifth elastic body 56 and the dummy winding portion, thereby minimizing the defect rate.

4 is a plan view illustrating an arrangement of a winding unit according to another embodiment. Unlike the winding portion of FIG. 2B in which one winding portion is branched into two winding portions and combined again, the winding portion of FIG. 4 includes second and third winding portions 65 and 66 .

As shown in FIG. 4 , the second and third winding parts 65 and 66 start from one side of the support part 57 , pass through the 5 elastic body 56 , and are on the external gimble 55 . form a quadrant It extends through the fourth elastic body 54 , and the second winding portion 65 forms a semicircle on the inner gimble 53 , and the third winding portion 66 is formed on the inner gimble 53 . form another semicircle.

The second and third winding parts 65 and 66 again pass through the fourth elastic body 54 to form another quadrant on the outer gimble 55 , and pass through the fifth elastic body 56 to form a second quadrant of the support part 57 . ends on the other side.

That is, the second and third winding portions 65 and 66 are formed on the second and fourth quadrants of the outer gimble 55 . The scanning micromirror 50 according to the present embodiment includes third to sixth dummy winding portions 73 , 74 , 75 and 76 disposed in the first and third quadrants of the outer gimble 55 . The third and fourth dummy winding parts 73 and 74 are disposed in the first quadrant, and the fifth and sixth dummy winding parts 75 and 76 are formed in the third quadrant.

A space is formed between the third to sixth dummy winding parts 73 , 74 , 75 and 76 so as not to contact the second and third winding parts 65 and 66 . The third to sixth dummy winding parts 73 , 74 , 75 and 76 may be made of substantially the same material as the second and third winding parts 65 and 66 . In addition, the third and fifth dummy winding portions 73 and 75 are substantially the same as the second and fourth quadrant regions of the third winding portion 66, and the fourth and sixth dummy winding portions ( 74 , 76 are substantially identical to the second and fourth quadrant regions of the third winding 66 .

In addition, at least some of the third to sixth dummy winding parts 73, 74, 75, and 76 may be formed together by the same process as the second and third winding parts 65 and 66, and The third to sixth dummy winding portions 73, 74, 75, and 76 and the second and third winding portions 65 and 66 are made of substantially the same material. Accordingly, the scanning micromirror can be balanced.

5A and 5B are plan views illustrating an arrangement of a winding unit according to another exemplary embodiment. The components of FIGS. 5A and 5B are substantially the same as those of FIG. 4 except for the arrangement structure of the dummy winding part. Accordingly, the same reference numerals are assigned to the same and similar components, and overlapping descriptions are omitted.

The third and fifth dummy winding portions 73 and 75 of the scanning micromirror according to the embodiment of FIG. 5A are formed on the front surface, and the fourth and sixth dummy winding portions 74 and 76 are formed on the rear surface. do. The shapes of the third to sixth dummy winding parts 73 , 74 , 75 and 76 are substantially the same as those of the dummy winding parts of FIG. 4 .

According to the present embodiment, since the dummy winding portion can be reduced in contact with the second and third winding portions, the defect rate can be minimized.

The scanning micromirror according to FIG. 5B includes seventh and eighth dummy winding portions 77 and 78 formed in the first and third quadrants of the outer gimble 55 . The seventh and eighth dummy winding portions 77 and 78 have a different shape from the second and third winding portions 55 and 56 and are formed wider than the second and third winding portions 65 and 66 . can be

However, the second and third winding portions 65 and 66 may be formed to have substantially the same mass as the second and fourth quadrant regions.

In the scanning micromirror described above, the configuration and method of the above-described embodiments are not limitedly applicable, but all or part of each embodiment is selectively combined so that various modifications can be made. could be

Claims (10)

a mirror plate driven with a first elastic body as a first rotational shaft;
an inner gimble formed in a circular shape surrounding the mirror plate and driven with a second elastic body as a second rotation axis;
an outer gimble formed to surround the inner gimble and divided into first, second, third and fourth regions by the first and second rotation shafts;
It consists of a first winding part formed on one surface of the inner gimble in a circular shape and a second winding part extending from the first region and formed in two regions facing each other among the first to fourth regions, a winding to form a driving force;
a magnet forming the electromagnetic field together with the winding unit; and
and a dummy winding portion formed in the remaining two regions opposite to each other in which the second winding portion is not disposed among the first to fourth regions;
The dummy winding part,
A scanning micromirror that is physically and electrically spaced apart from the first winding part and the second winding part. According to claim 1,
The scanning micromirror, characterized in that the dummy winding portion and the winding are made of the same material. 3. The method of claim 2,
The scanning micromirror, characterized in that the mass of the second winding formed in the partial region and the mass of the dummy winding formed in the remaining region are the same. 4. The method of claim 3,
When the second winding is formed on one surface of the outer gimble,
and the dummy winding part includes a first divided winding formed on one surface of the outer gimble and a second divided winding formed on the other surface of the outer gimble. 5. The method of claim 4,
and the second dividing winding is disposed closer to the second elastic body than the first dividing winding. 5. The method of claim 4,
The scanning micromirror of claim 1, wherein the first and second dividing windings are formed in separate regions of the remaining regions so as not to overlap. According to claim 1,
The winding portion is a scanning micromirror comprising a pair of windings arranged side by side on the inner gimble and the outer gimble. 8. The method of claim 7,
and the dummy winding unit includes a pair of dummy windings corresponding to the pair of windings formed in the outer gimble. 8. The method of claim 7,
and the dummy winding portion includes first and second dummy windings corresponding to a pair of windings formed in the outer gimble. 8. The method of claim 7,
The scanning micromirror, characterized in that the dummy winding portion is formed of windings formed to have the same mass as the pair of windings formed in one region of the outer gimble.

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