JP6579241B2 - Optical scanner and head mounted display - Google Patents

Description

  The present invention relates to an optical scanner, an image display device, a head mounted display, and a head up display.

  Optical scanners for performing drawing by optical scanning are used in laser printers, image display devices, and the like. An optical scanner including a torsion bar spring in two orthogonal directions is disclosed in Patent Document 1. According to this, in the optical scanner, the movable plate is supported so as to be swingable by the pair of first torsion bar springs. The other end of the first torsion bar spring is connected to a frame-shaped displacement portion. Further, the displacement portion is supported by the second torsion bar spring so as to be swingable. The other end of the second torsion bar spring is connected to a frame-shaped support portion. The direction in which the first torsion bar spring extends is defined as a first direction, and the direction in which the second torsion bar spring extends is defined as a second direction. The first direction and the second direction are orthogonal to each other. As a result, the movable plate can swing around two orthogonal directions as the rotation axis.

  A permanent magnet is provided in the displacement portion. The permanent magnet is installed at an angle of 45 ° with respect to the first direction. An electromagnet is installed at a location away from the permanent magnet at a location facing the permanent magnet. The electromagnet receives a drive signal obtained by synthesizing a sawtooth-shaped vertical scanning drive signal of about 60 Hz and a sinusoidal horizontal scanning drive signal of about 25 KHz. At this time, the movable plate operates in response to the horizontal scanning drive signal with respect to the displacement portion. The displacement part operates in response to the vertical scanning drive signal with respect to the support part.

  An optical scanner including a torsion bar spring in one direction is disclosed in Patent Document 2. According to this, in the optical scanner, the first movable plate is swingably supported by the pair of torsion bar springs. One torsion bar spring is fixed to the support. The other torsion bar spring portion is connected to the second movable plate. A coil is installed on the second movable plate, and a magnetic field acts on the coil to swing the second movable plate. Then, the first movable plate swings due to the swing of the second movable plate. A damper structure is installed on the second movable plate. The Q value of the optical scanner is reduced by the damper structure.

JP 2008-216921 A JP 2005-250077 A

  In order to use an optical scanner in a portable device, there is a demand for downsizing the optical scanner. When the optical scanner of Patent Document 1 is miniaturized, the displacement portion needs to be miniaturized. At this time, the displacement portion that is scheduled to operate only in response to the vertical scanning drive signal is easily operated in response to the horizontal scanning drive signal. As a result, the movable plate operates with an unnecessary vibration component added to the vertical scanning. Therefore, there has been a demand for an optical scanner having improved vibration performance so that the horizontal scanning hardly affects the vertical scanning of the movable plate even if the optical scanner is small.

  The present invention has been made to solve the above-described problems, and can be realized as the following forms or application examples.

[Application Example 1]
An optical scanner according to this application example, comprising: a movable plate provided with a light reflecting portion that reflects light; a first torsion bar spring portion that supports the movable plate so as to be swingable about a first axis; A displacement part connected to one torsion bar spring part; a second torsion bar spring part supporting the displacement part so as to be swingable about a second axis intersecting the first axis; one magnetic pole and the other A permanent magnet provided at the displacement portion so that a line segment connecting the magnetic poles of the first and second axes is inclined with respect to the first axis and the second axis, and provided at a distance from the displacement portion. A coil that generates an acting magnetic field, and the displacement portion intersects with a frame portion that surrounds the movable plate, a thickness that is thinner than the frame portion, and the second torsion bar spring portion extends from the frame portion. And a damper portion extending in a direction to perform.

  According to this application example, one end of the first torsion bar spring portion supports the movable plate, and the other end of the first torsion bar spring portion is coupled to the displacement portion. The displacement portion is supported by the second torsion bar spring portion. The direction in which the first torsion bar spring portion extends intersects the direction in which the second torsion bar spring portion extends. The movable plate swings around a first axis that is around the axis of the first torsion bar spring part, and the displacement part swings around a second axis that is around the axis of the second torsion bar spring part. Accordingly, the light reflecting portion swings around two intersecting axes.

  A permanent magnet is fixed to the displacement portion. And the coil which drives a displacement part by making a magnetic field act on a permanent magnet is installed. By energizing the coil and driving the displacement portion, the optical scanner can be swung around the two-direction axes intersecting the light reflecting portion. The displacement part includes a frame part and a damper part. The frame portion maintains a relative position between the first torsion bar spring portion and the second torsion bar spring portion. The damper portion extends from the frame portion in a direction intersecting with the direction in which the second torsion bar spring portion extends. When the displacement portion swings around the second axis, the damper portion generates an air flow around and functions as a damper. Thereby, it is possible to make it difficult for the displacement portion to react to driving with a high frequency. Accordingly, when the light reflecting portion swings around the axis of the second torsion bar spring portion, it is possible to make it difficult to react to a drive with a high frequency. As a result, the vibration performance of the light reflecting portion can be improved.

[Application Example 2]
In the optical scanner according to the application example described above, the thickness of the damper portion is larger than the thickness of the location close to the second torsion bar spring portion.

  According to this application example, the damper portion is thicker at a location away from a location near the second torsion bar spring portion. Therefore, the displacement portion can increase the moment of inertia as compared with the case where the thickness of the location apart from the second torsion bar spring portion of the damper portion is thin. Thereby, it is possible to make it difficult for the displacement portion to react to driving with a high frequency. Therefore, when the light reflecting portion swings around the second axis, it is possible to make it difficult to respond to high frequency driving. As a result, the vibration performance of the light reflecting portion can be improved.

[Application Example 3]
In the optical scanner according to the application example, the displacement portion includes a thin plate structure portion that is thinner than the frame portion and extends in a direction in which the second torsion bar spring portion extends from the frame portion, and the second torsion bar spring. The connecting portion between the portion and the thin plate structure portion is arcuate.

  According to this application example, the displacement portion includes the thin plate structure portion following the frame portion. Since the thin plate structure portion is thinner than the frame portion, it is more easily deformed than the frame portion. The second torsion bar spring portion is connected to the thin plate structure portion. Therefore, when the second torsion bar spring part is twisted than when the second torsion bar spring part is connected to the frame part, the displacement part and the second torsion bar spring part are less likely to cause stress concentration. Further, the connecting portion between the second torsion bar spring portion and the thin plate structure portion has an arc shape. Therefore, when the second torsion bar spring portion is twisted, the displacement portion can hardly cause stress concentration in the connection portion.

[Application Example 4]
In the optical scanner according to the application example described above, the light reflecting portion includes a reflecting plate and a support column portion that supports the reflecting plate, and the reflecting plate is installed with a gap in the thickness direction of the displacement portion and the reflecting plate. A part of the reflection plate overlaps the displacement portion in a plan view as viewed from the thickness direction of the reflection plate.

  According to this application example, the reflecting plate and the displacement portion are installed with a space therebetween. And the reflective plate has overlapped with the displacement part in planar view seen from the thickness direction of the reflective plate. With this configuration, the displacement portion can be shortened compared to when the reflector and the displacement portion are located on the same plane. The shorter the displacement portion, the better the responsiveness with respect to high frequency driving compared to when the displacement portion is long. Therefore, the optical scanner can improve the responsiveness to high frequency driving.

[Application Example 5]
In the optical scanner according to the application example, the thick portion of the damper portion protrudes on a side opposite to the side where the permanent magnet is installed with respect to the displacement portion.

  According to this application example, the side where the permanent magnet is installed with respect to the displacement part and the side where the thicker part of the damper part protrudes are on the opposite side. Thereby, the gravity center of a displacement part can be closely approached to the axis | shaft of a 2nd torsion bar spring part. Therefore, the combined stress due to the torsional stress and the bending stress applied to the second torsion bar spring portion can be reduced, and the reliability against the fracture of the beam can be enhanced.

[Application Example 6]
An image display device according to this application example, comprising: a light source that emits light; and an optical scanner, wherein the optical scanner includes a movable plate that includes a light reflecting portion that reflects light; A first torsion bar spring portion that is swingably supported around the axis of the first torsion bar, a displacement portion connected to the first torsion bar spring portion, and a second axis around the first axis. And the second torsion bar spring portion supported in a swingable manner, and a line segment connecting one magnetic pole and the other magnetic pole is inclined with respect to the first axis and the second axis. A permanent magnet provided, and a coil that is provided at a distance from the displacement portion and generates a magnetic field that acts on the permanent magnet. The displacement portion has a frame portion that surrounds the movable plate, and is thicker than the frame portion. In a direction intersecting with the direction in which the second torsion bar spring portion extends from the frame portion. Damper unit for standing, characterized in that it comprises a.

  According to this application example, the light reflecting portion reflects the light emitted from the light source. Since the light reflecting portion swings around two intersecting axes, the image display device can display an image by changing the traveling direction of the light. When the displacement portion swings around the second axis, the damper portion functions as a damper by causing the surrounding gas to flow. Thereby, it is possible to make it difficult for the displacement portion to react to driving with a high frequency. Therefore, when the light reflecting portion swings around the second axis, it is possible to make it difficult to respond to high frequency driving. As a result, the image display apparatus can improve the vibration performance of the light reflecting portion.

[Application Example 7]
A head-mounted display according to this application example is a head-mounted display including a frame attached to an observer's head, a light source that emits light, and an optical scanner provided in the frame. The scanner is connected to a movable plate having a light reflecting portion that reflects light, a first torsion bar spring portion that supports the movable plate so as to be swingable about a first axis, and the first torsion bar spring portion. A line segment connecting the displacement portion, the second torsion bar spring portion supporting the displacement portion so as to be swingable around a second axis intersecting the first axis, and one magnetic pole and the other magnetic pole is A permanent magnet provided in the displacement part so as to be inclined with respect to the first axis and the second axis; a coil provided apart from the displacement part and generating a magnetic field acting on the permanent magnet; The displacement portion is Frame portion surrounding the plate, characterized in that it comprises a damper unit, which extends in a direction from said the frame portion small thickness second torsion bar spring portion intersects the extending direction from the frame portion.

  According to this application example, the observer can attach the head mounted display to the head using the frame. In a head mounted display, a light source emits light to an optical scanner. In the optical scanner, the light reflecting portion reflects the light emitted from the light source. Since the light reflecting portion swings around two intersecting axes, the light scanner can display an image by changing the traveling direction of the light. When the displacement portion swings around the second axis, the damper portion functions as a damper by causing the surrounding gas to flow. Thereby, it is possible to make it difficult for the displacement portion to react to driving with a high frequency. Therefore, when the light reflecting portion swings around the second axis, it is possible to make it difficult to respond to high frequency driving. As a result, the head mounted display can be an apparatus equipped with an optical scanner with good vibration performance.

[Application Example 8]
A head-up display according to this application example is a head-up display that irradiates light on a windshield of an automobile, and includes a light source that emits light and an optical scanner, and the optical scanner reflects light that reflects light. A movable plate provided with a reflecting portion; a first torsion bar spring portion that supports the movable plate so as to be swingable about a first axis; a displacement portion connected to the first torsion bar spring portion; and the displacement portion The second torsion bar spring portion that supports the first torsion bar spring portion so as to be swingable around a second axis that intersects the first axis, and a line segment that connects one magnetic pole and the other magnetic pole is the first axis and the first A permanent magnet provided in the displacement portion so as to be inclined with respect to the axis of 2 and a coil provided apart from the displacement portion and generating a magnetic field acting on the permanent magnet, the displacement portion comprising: The frame surrounding the movable plate, the frame Damper portion extending in a direction from said small thickness the frame portion second torsion bar spring portion intersects the direction of extension, characterized in that it comprises a.

According to this application example, in the head-up display, the light scanner emits light emitted from the light source to the windshield of the automobile. In the optical scanner, the light reflecting portion reflects the light emitted from the light source. Since the light reflecting portion swings around two intersecting axes, the head-up display can display an image by changing the traveling direction of the light. When the displacement portion swings around the second axis, the damper portion functions as a damper by causing the surrounding gas to flow.
Thereby, it is possible to make it difficult for the displacement portion to react to driving with a high frequency. Therefore, when the light reflecting portion swings around the second axis, it is possible to make it difficult to respond to high frequency driving. As a result, the head-up display can be an apparatus provided with an optical scanner with good vibration performance.

1 is a schematic perspective view illustrating a configuration of an image display apparatus according to a first embodiment. (A) is a schematic top view which shows the structure of an optical scanner, (b) is a schematic plane sectional view which shows the structure of an optical scanner. (A) And (b) is a schematic sectional side view which shows the structure of an optical scanner. (A) is an electrical block diagram showing the configuration of the voltage applying means, (b) is a diagram for explaining the first voltage waveform, (c) is a diagram for explaining the second voltage waveform. The schematic diagram for demonstrating operation | movement of a displacement part. FIG. 4 is a schematic diagram for explaining a method for manufacturing an optical scanner. FIG. 4 is a schematic diagram for explaining a method for manufacturing an optical scanner. In connection with the second embodiment, (a) is a schematic plan view showing a structure of an optical scanner, and (b) is a schematic side sectional view showing the structure. In connection with the third embodiment, (a) is a schematic plan view showing the structure of an optical scanner, and (b) is a schematic side sectional view showing the structure. In connection with the fourth embodiment, (a) is a schematic plan view showing a structure of an optical scanner, and (b) is a schematic side sectional view showing the structure. The schematic perspective view which shows the head-up display concerning 5th Embodiment. The schematic perspective view which shows the head mounted display concerning 6th Embodiment.

In the present embodiment, characteristic examples of an image display device, an optical scanner, a head-up display, a head-mounted display, and an optical scanner manufacturing method will be described with reference to the accompanying drawings. In addition, each member in each drawing is illustrated with a different scale for each member in order to make the size recognizable on each drawing.
(First embodiment)
<Image display device>
The configuration of the image display device will be described with reference to FIG. FIG. 1 is a schematic perspective view showing the configuration of the image display apparatus. An image display apparatus 1 shown in FIG. 1 is an apparatus that displays an image by two-dimensionally scanning a drawing laser beam 3 as light on a screen 2 such as a screen or a wall surface. The image display device 1 includes a drawing light source unit 4 that emits a drawing laser beam 3, an optical scanner 5 that scans the drawing laser beam 3, and a mirror 6 that reflects the drawing laser beam 3 scanned by the optical scanner 5. And a control unit 7 for controlling the operation of the drawing light source unit 4 and the optical scanner 5. The mirror 6 may be provided as necessary and may be omitted.

  The drawing light source unit 4 includes laser light sources 8r, 8g, and 8b as light sources of red, green, and blue, and collimator lenses 9r, 9g, and 9b provided in correspondence with the laser light sources 8r, 8g, and 8b, and Dichroic mirrors 10r, 10g, and 10b.

  Each of the laser light sources 8r, 8g, and 8b has a drive circuit (not shown) that drives the light source. The laser light source 8r emits red laser light 3r, the laser light source 8g emits green laser light 3g, and the laser light source 8b emits blue laser light 3b. The laser beams 3r, 3g, and 3b are emitted in response to the drive signals transmitted from the control unit 7, and are converted into parallel light or substantially parallel light by the collimator lenses 9r, 9g, and 9b. As the laser light sources 8r, 8g, and 8b, for example, semiconductor lasers such as edge emitting semiconductor lasers and surface emitting semiconductor lasers can be used. By using a semiconductor laser, the laser light sources 8r, 8g, and 8b can be downsized.

  A dichroic mirror 10r, a dichroic mirror 10g, and a dichroic mirror 10b are arranged following the arrangement of the laser light sources 8r, 8g, and 8b. The dichroic mirror 10r has a characteristic of reflecting the laser beam 3r. The dichroic mirror 10g has characteristics of reflecting the laser beam 3g and transmitting the laser beam 3r. The dichroic mirror 10b has a characteristic of reflecting the laser beam 3b and transmitting the laser beams 3r and 3g. By these dichroic mirrors 10r, 10g, and 10b, the laser beams 3r, 3g, and 3b of the respective colors are combined to become a drawing laser beam 3.

  The optical scanner 5 includes a reflecting surface 5a as a light reflecting portion, and the drawing laser light 3 emitted from the drawing light source unit 4 irradiates the reflecting surface 5a. The optical scanner 5 swings the reflecting surface 5a around the horizontal axis 11 as the second axis, and swings the reflecting surface 5a around the vertical axis 12 as the first axis. Thus, the drawing laser beam 3 can be scanned in two directions, vertical and horizontal. That is, the optical scanner 5 has a function of two-dimensionally scanning the drawing laser beam 3. The drawing laser beam 3 reflected from the reflecting surface 5 a reflects the mirror 6 and irradiates the screen 2. As a result, a predetermined pattern is drawn on the screen 2.

  2A is a schematic top view showing the structure of the optical scanner, and FIG. 2B is a schematic plan sectional view showing the structure of the optical scanner. FIG. 2B is a view of the optical scanner 5 as seen from the bottom side. 3A and 3B are schematic side sectional views showing the structure of the optical scanner. 3A shows a cross section taken along the line AA in FIG. 2A, and FIG. 3B shows a cross section taken along the line BB in FIG. 2A. FIG. 2B shows a cross section taken along the line C-C in FIG. As shown in FIGS. 2 and 3, the optical scanner 5 includes a bottomed rectangular tube-shaped casing 13, and the bottom plate 13 a of the casing 13 is a quadrangle. On the bottom plate 13a, a rectangular side plate 13b is erected. Inside the housing 13, a magnetic core 14 and a coil 15 are installed on a bottom plate 13a. The magnetic core 14 has a prismatic shape, and a coil 15 is disposed around the magnetic core 14. Note that the shape of the magnetic core 14 is not limited to a prismatic shape, and may be, for example, a cylindrical shape. The magnetic core 14 and the coil 15 constitute an electromagnet. A voltage application unit 16 is connected to the coil 15, and the voltage application unit 16 supplies a current to the coil 15.

  The direction in which one side of the bottom plate 13a of the housing 13 extends is defined as the X direction. The X direction is a direction in which the horizontal axis 11 extends. A direction perpendicular to the X direction on the bottom surface is taken as a Y direction. The Y direction is a direction in which the vertical axis 12 extends. The thickness direction of the magnetic core 14 is taken as the Z direction. The side plate 13b of the housing 13 extends in the Z direction from the bottom plate 13a. The Z direction is the direction in which the reflecting surface 5a faces. The X direction, the Y direction, and the Z direction are orthogonal to each other. The drawing laser beam 3 is irradiated from the Z direction, and the drawing laser beam 3 reflected by the reflecting surface 5a travels in the Z direction.

  A structure 18 is installed on the housing 13. The structure 18 includes a cylindrical support connection portion 21 having a quadrangular shape when viewed from the Z direction, and the support connection portion 21 is placed on the side plate 13b. An oxide film 21 a is provided on the surface of the support connecting portion 21 facing the Z direction. A rectangular frame-shaped support portion 22 is installed on the Z direction side of the support connecting portion 21. The support part 22 and the support connection part 21 have substantially the same shape as viewed from the Z direction.

  In the support portion 22, a third shaft portion 23 and a fourth shaft portion 24 as second torsion bar spring portions extending in the X direction are installed at the center in the Y direction. The third shaft portion 23 and the fourth shaft portion 24 are disposed along the horizontal axis 11 so as to face each other. A displacement portion 25 is installed between the third shaft portion 23 and the fourth shaft portion 24. The displacement portion 25 has a rectangular frame shape and is a rectangle that is long in the Y direction.

  The third shaft portion 23 has one end connected to the support portion 22 and the other end connected to the displacement portion 25. Similarly, one end of the fourth shaft portion 24 is connected to the support portion 22, and the other end is connected to the displacement portion 25. Accordingly, the third shaft portion 23 and the fourth shaft portion 24 support the displacement portion 25.

  The third shaft portion 23 and the fourth shaft portion 24 function as a pair of torsion bar springs, and the displacement portion 25 swings around the horizontal shaft 11 as a rotation axis. In the third shaft portion 23 and the fourth shaft portion 24, the planar shape of the place where the third shaft portion 23 and the fourth shaft portion 24 are connected to the support portion 22 is an arc. Thereby, it is possible to suppress stress concentration at the place where the third shaft portion 23 and the fourth shaft portion 24 are connected to the support portion 22.

  The displacement part 25 is comprised from the plate-shaped plate-shaped member 26 and the magnet support part 27 as a frame part. The magnet support portion 27 is located on the −Z direction side of the plate-like member 26 and has a quadrangular rectangular tube shape. The part located in the + Y direction side from the magnet support part 27 among the displacement parts 25 is defined as a first thin plate structure part 25a as a damper part. Furthermore, the part located in the -Y direction side from the magnet support part 27 among the displacement parts 25 is also made into the 1st thin plate structure part 25a. Therefore, the displacement part 25 is arrange | positioned in order of the 1st thin plate structure part 25a, the frame part 25b, and the 1st thin plate structure part 25a in the Y direction. The first thin plate structure portion 25 a is constituted by a part of the plate-like member 26. And the part inside the magnet support part 27 including the magnet support part 27 is made into the frame part 25b. The frame portion 25 b is composed of a part of the plate-like member 26 and a magnet support portion 27. The thickness of the first thin plate structure portion 25 a is the thickness of the plate-like member 26, and the thickness of the frame portion 25 b is the thickness of the plate-like member 26 plus the thickness of the magnet support portion 27. Therefore, the first thin plate structure 25a is thin and the frame 25b is thick.

  In the plate-like member 26, there are portions that do not overlap the magnet support portion 27 on the + X direction side and the −X direction side of the magnet support portion 27. A portion that does not overlap with the magnet support portion 27 is defined as a second thin plate structure portion 26a as a thin plate structure portion. The third shaft portion 23 and the fourth shaft portion 24 are connected to the second thin plate structure portion 26a. And the planar shape is a circular arc in the connection part 26b which the 3rd axial part 23 and the 4th axial part 24 connect with the 2nd thin plate structure part 26a. Thereby, when the 3rd axial part 23 and the 4th axial part 24 are twisted, it is preventing that the stress concentration arises in the connection part 26b.

  A permanent magnet 28 is provided on the side of the magnetic core 14 of the magnet support portion 27. The permanent magnet 28 is driven by an electromagnet composed of the coil 15 and the magnetic core 14.

  In the center of the displacement part 25 in the X direction, a first shaft part 29 as a first torsion bar spring part extending in the Y direction and a second shaft part 30 as a first torsion bar spring part are installed. The first shaft portion 29 and the second shaft portion 30 are disposed along the vertical axis 12 so as to face each other. A movable plate 31 is installed between the first shaft portion 29 and the second shaft portion 30. The movable plate 31 has a circular plate shape, and the surface of the movable plate 31 on the Z direction side is a reflection surface 5a. A hole located on the X direction side of the first shaft portion 29 and the second shaft portion 30 in the displacement portion 25 is referred to as a first hole 25c, and a hole located on the −X direction side of the first shaft portion 29 and the second shaft portion 30. Is the second hole 25d.

  One end of the first shaft portion 29 is connected to the plate member 26, and the other end is connected to the movable plate 31. Similarly, one end of the second shaft portion 30 is connected to the plate member 26 and the other end is connected to the movable plate 31. Thus, the first shaft portion 29 and the second shaft portion 30 support the movable plate 31. The first shaft portion 29 and the second shaft portion 30 function as a pair of torsion bar springs, and the movable plate 31 swings around the vertical shaft 12 as a rotation axis. The planar shape of the connecting portion 29a and the connecting portion 30a where the first shaft portion 29 and the second shaft portion 30 are connected to the plate-like member 26 is an arc. Thereby, the first shaft portion 29 and the second shaft portion 30 prevent stress concentration from occurring in the connection portion 29a and the connection portion 30a when twisted.

  The movable plate 31 constitutes a first vibration system that swings or reciprocates around the vertical axis 12 as a rotation axis. The first shaft portion 29 and the second shaft portion 30 function as a torsion bar spring, and the first shaft portion 29 and the second shaft portion 30 have a predetermined spring constant. The natural frequency when the movable plate 31 swings is determined by the spring constants of the first shaft portion 29 and the second shaft portion 30 and the mass of the movable plate 31. The torsion bar spring is also called a torsion bar. The displacement unit 25 constitutes a second vibration system that swings or reciprocates around the horizontal axis 11 as a rotation axis. The permanent magnet 28, the coil 15, the magnetic core 14, and the voltage application unit 16 constitute driving means for driving the first vibration system and the second vibration system described above.

  The movable plate 31 is swung with the vertical axis 12 as a rotation axis, and the displacement portion 25 is swung with the horizontal axis 11 as a rotation axis. Thereby, the movable plate 31 and the reflecting surface 5a can be swung around two axes of the horizontal axis 11 and the vertical axis 12 which are orthogonal to each other. Note that the shapes of the first shaft portion 29, the second shaft portion 30, the third shaft portion 23, and the fourth shaft portion 24 are not limited to those described above. And may have a branched portion or a branched portion. Further, the shaft portions of the first shaft portion 29, the second shaft portion 30, the third shaft portion 23, and the fourth shaft portion 24 may be divided into two shafts.

  A reflective film 32 as a light reflecting portion is provided on the surface of the movable plate 31 facing the Z direction, and a part of the drawing laser light 3 to be irradiated is reflected by the reflective surface 5 a that is the surface of the reflective film 32. The movable plate 31 and the reflective film 32 constitute a reflector 33.

  The displacement portion 25 is longer in the direction along the vertical axis 12 than in the direction along the horizontal axis 11. That is, when the length of the displacement portion 25 in the direction along the vertical axis 12 is a and the length of the displacement portion 25 in the direction along the horizontal axis 11 is b, the relationship of a> b is satisfied. Thereby, the length of the optical scanner 5 in the direction along the horizontal axis 11 can be suppressed while securing the necessary lengths for the first shaft portion 29 and the second shaft portion 30. Then, the swing of the displacement unit 25 having the horizontal axis 11 as the rotation axis can be easily responded to a low frequency, and the swing of the displacement unit 25 having the vertical axis 12 as a rotation axis can be easily responded to a high frequency. can do.

  The support portion 22, the third shaft portion 23, the fourth shaft portion 24, the plate member 26, the first shaft portion 29, the second shaft portion 30, and the movable plate 31 are integrally formed with the first Si layer (device layer). Is formed. These portions and the magnet support portion 27 etch the SOI substrate in which the first Si layer (device layer), the oxide film 21a (box layer), and the second Si layer (handle layer) are stacked in this order. It is formed by. A magnet support portion 27 and a support connection portion 21 are formed from the second Si layer. The SOI substrate can be finely processed by etching. Using the SOI substrate, the support portion 22, the third shaft portion 23, the fourth shaft portion 24, the plate member 26, the first shaft portion 29, the second shaft portion 30, the movable plate 31, the magnet support portion 27, and the support connecting portion. By forming 21, the dimensional accuracy of these parts can be made excellent. Thereby, the vibration characteristics of the first vibration system and the second vibration system can be made excellent.

  A support connecting portion 21 is disposed on the coil 15 side of the support portion 22. The support connecting portion 21 increases the strength of the support portion 22. Further, the support connecting portion 21 surrounds the XY direction of the magnet support portion 27. Thereby, it is possible to prevent stress from being applied to the third shaft portion 23 and the fourth shaft portion 24 when the operator holds the structure 18. The support connecting portion 21 is formed of silicon, and an oxide film 21a is formed on the surface of the support connecting portion 21 on the support portion 22 side.

  A permanent magnet 28 is joined to the displacement portion 25 on the −Z direction side via a magnet support portion 27. Although it does not specifically limit as a joining method of the displacement part 25, the magnet support part 27, and the permanent magnet 28, For example, the joining method using an adhesive agent can be used. The permanent magnet 28 is disposed so as to be symmetric with respect to the intersection of the vertical axis 12 and the horizontal axis 11 in a plan view viewed from the Z direction.

  The permanent magnet 28 has a rod shape extending in a direction inclined with respect to both the horizontal axis 11 and the vertical axis 12. The permanent magnet 28 is magnetized in the longitudinal direction. The permanent magnet 28 on the + X direction and the + Y direction side is magnetized to the N pole, and the permanent magnet 28 on the −X direction and −Y direction side is magnetized to the S pole. The permanent magnet 28 is magnetized in a direction in which a line segment connecting the N pole and the S pole is inclined with respect to the horizontal axis 11 and the vertical axis 12 in plan view.

  The inclination angle θ of the magnetization direction (extending direction) of the permanent magnet 28 with respect to the horizontal axis 11 is not particularly limited, but is preferably 30 ° or more and 60 ° or less, and more preferably 45 ° or more and 60 ° or less. Preferably, it is 45 °. By providing the permanent magnet 28 in this way, the movable plate 31 can be swung around the two axes of the horizontal axis 11 and the vertical axis 12 smoothly and reliably.

  As such a permanent magnet 28, for example, a neodymium magnet, a ferrite magnet, a samarium cobalt magnet, an alnico magnet, a bond magnet, or the like can be suitably used. Such a permanent magnet 28 is obtained by magnetizing a hard magnetic material, and is formed, for example, by magnetizing the hard magnetic material before magnetization in the displacement portion 25. This is because if the already magnetized permanent magnet 28 is to be installed in the displacement portion 25, the permanent magnet 28 may not be installed at a desired position due to the influence of the magnetic field of the outside or other components.

  A coil 15 is provided immediately below the permanent magnet 28. Thereby, the magnetic field generated from the coil 15 can be efficiently applied to the permanent magnet 28. Thereby, power saving and size reduction of the optical scanner 5 can be achieved. The coil 15 is provided by being wound around the magnetic core 14. Thereby, the magnetic field generated in the coil 15 can be efficiently applied to the permanent magnet 28. The magnetic core 14 may be omitted when the magnetic field output from the coil 15 is sufficient.

  The coil 15 is electrically connected to the voltage application unit 16. Then, when a voltage is applied to the coil 15 by the voltage application unit 16, a magnetic field having a magnetic flux orthogonal to the horizontal axis 11 and the vertical axis 12 is generated from the coil 15.

  Although the dimension of each member is not specifically limited, In this embodiment, for example, the dimension of each part is set to the following value. The length of the optical scanner 5 in the X direction is 3850 μm, and the length in the Y direction is 3990 μm. The length of the optical scanner 5 in the Z direction is 4490 μm to 4590 μm. The casing 13 has a height of 4200 μm to 4300 μm, and the support connecting portion 21 has a height of 250 μm. The width of the side plate 13b, the support connecting portion 21 and the support portion 22 is 500 μm. Accordingly, the hole inside the support portion 22 has a length in the X direction of 2850 μm and a length in the Y direction of 2990 μm.

  The plate-like member 26 has a length in the X direction of 1700 μm and a length in the Y direction of 2890 μm. The plate member 26 has a thickness of 65 μm. The length in the Y direction of the first hole 25c and the second hole 25d is 1590 μm, and the length from the end in the X direction of the first hole 25c to the end in the −X direction of the second hole 25d is 1100 μm. . The length from the end on the Y direction side of the first hole 25c and the second hole 25d of the magnet support portion 27 to the magnet support portion 27 on the Y direction side is 65 μm. The width of the magnet support portion 27 on the Y direction side is 150 μm. The length from the end of the magnet support portion 27 on the Y direction side to the end of the displacement portion 25 on the Y direction side is 435 μm. Therefore, the length from the end in the Y direction of the first hole 25c and the second hole 25d to the end in the Y direction of the plate member 26 is 650 μm. In the Y direction, the length between the support portion 22 and the plate-like member 26 is 50 μm. The thickness of the magnet support portion 27 is 80 μm to 150 μm, and the length of the magnet support portion 27 in the Z direction is 250 μm.

  The diameter of the movable plate 31 is 1000 μm. The permanent magnet 28 has a width of 500 μm to 800 μm and a length of 1000 μm. The permanent magnet 28 has a length in the Z direction of 200 μm to 300 μm. The length of the magnetic core 14 and the coil 15 in the Z direction is 3700 μm.

  FIG. 4A is an electric block diagram showing the configuration of the voltage applying means. As shown in FIG. 4A, the voltage application unit 16 includes a first voltage generation unit 34 that generates a first voltage waveform for swinging the movable plate 31 with the vertical axis 12 as a rotation axis. . Further, the voltage application unit 16 includes a second voltage generation unit 35 that generates a second voltage waveform for swinging the displacement unit 25 with the horizontal axis 11 as a rotation axis. Furthermore, the voltage application unit 16 includes a voltage superimposing unit 36 that superimposes the first voltage waveform and the second voltage waveform, and the voltage superimposing unit 36 outputs the superimposed voltage to the coil 15.

  FIG. 4B is a diagram for explaining the first voltage waveform. In FIG.4 (b), a vertical axis | shaft shows a voltage and a horizontal axis shows progress of time. The first voltage waveform 37 shows the waveform of the voltage output from the first voltage generator 34. The first voltage waveform 37 has a waveform like a sine wave that periodically changes in a cycle 37a. The frequency of the first voltage waveform 37 is preferably 10 to 40 kHz, for example. In the present embodiment, for example, the frequency of the first voltage waveform 37 is set to be equal to the torsional resonance frequency (f1) of the first vibration system configured by the movable plate 31, the first shaft portion 29, and the second shaft portion 30. Has been. As a result, the swing angle of the movable plate 31 with the vertical axis 12 as the rotation axis can be increased. Alternatively, the power used for swinging the movable plate 31 can be suppressed.

  FIG. 4C is a diagram for explaining the second voltage waveform. In FIG.4 (c), a vertical axis | shaft shows a voltage and a horizontal axis shows progress of time. The second voltage waveform 38 shows the waveform of the voltage output from the second voltage generator 35. The second voltage waveform 38 has a sawtooth waveform that periodically changes in a period 38a longer than the period 37a. The frequency of the second voltage waveform 38 is lower than the frequency of the first voltage waveform 37, and is preferably 30 to 120 Hz (about 60 Hz), for example. In the present embodiment, the frequency of the second voltage waveform 38 includes the movable plate 31, the first shaft portion 29, the second shaft portion 30, the displacement portion 25, the third shaft portion 23, the fourth shaft portion 24, the permanent magnet 28, and the like. It is adjusted so as to have a frequency different from the torsional resonance frequency (f2) of the second vibration system constituted by Thus, the frequency of the second voltage waveform 38 is made smaller than the frequency of the first voltage waveform 37. As a result, the frequency of the second voltage waveform 38 is set with the horizontal axis 11 as the rotation axis, while the movable plate 31 is swung with the frequency of the first voltage waveform 37 with the vertical axis 12 as the rotation axis, more reliably and smoothly. Thus, the displacement portion 25 can be swung.

  Further, when the torsional resonance frequency of the first vibration system is f1 [Hz] and the torsional resonance frequency of the second vibration system is f2 [Hz], f1 and f2 satisfy the relationship of f2 <f1. Is preferred. Accordingly, the movable plate 31 is swung more smoothly at the frequency of the first voltage waveform 37 with the vertical axis 12 as the rotation axis, and the displacement portion at the frequency of the second voltage waveform 38 with the horizontal axis 11 as the rotation axis. 25 can be swung.

  Returning to FIG. 4A, the first voltage generation unit 34 and the second voltage generation unit 35 are connected to the control unit 7 and are driven based on a signal from the control unit 7. A voltage superimposing unit 36 is connected to the first voltage generating unit 34 and the second voltage generating unit 35. The voltage superimposing unit 36 includes an adder 36 a for applying a voltage to the coil 15. The adder 36 a receives the first voltage waveform 37 from the first voltage generator 34 and the second voltage waveform 38 from the second voltage generator 35. The adder 36 a superimposes the voltage waveforms of the first voltage waveform 37 and the second voltage waveform 38 and outputs them to the coil 15.

  Next, a method for driving the optical scanner 5 will be described. The frequency of the first voltage waveform 37 is set equal to the torsional resonance frequency of the first vibration system. The frequency of the second voltage waveform 38 is set to a frequency different from the torsional resonance frequency of the second vibration system, and is set to be smaller than the frequency of the first voltage waveform 37. For example, the frequency of the first voltage waveform 37 is set to 18 kHz, and the frequency of the second voltage waveform 38 is set to 60 Hz.

  The voltage superimposing unit 36 superimposes the first voltage waveform 37 and the second voltage waveform 38 and outputs the superimposed voltage waveform to the coil 15. When a voltage is applied to the coil 15, a magnetic field that attempts to attract one end (N pole) of the permanent magnet 28 to the coil 15 and to separate the other end (S pole) of the permanent magnet 28 from the coil 15 is generated. appear. The magnetic field at this time is referred to as a “first magnetic field”. When a voltage opposite to the first magnetic field is applied to the coil 15, one end (N pole) of the permanent magnet 28 is separated from the coil 15 and the other end (S pole) of the permanent magnet 28 is applied to the coil 15. A magnetic field to be attracted is generated. The magnetic field at this time is referred to as a “second magnetic field”. When the voltage indicated by the first voltage waveform 37 is applied to the coil 15, the magnetic field generated in the coil 15 is switched alternately between the first magnetic field and the second magnetic field.

  As described above, the magnetic field generated in the coil 15 is alternately switched between the first magnetic field and the second magnetic field, so that the permanent magnet 28 is swung. A vibration having a torsional vibration component having the vertical axis 12 as a rotation axis is excited in the displacement portion 25. With this vibration, the first shaft portion 29 and the second shaft portion 30 are twisted and deformed, and the movable plate 31 swings around the vertical axis 12 as the rotation axis at the frequency of the first voltage waveform 37. Since the frequency of the first voltage waveform 37 is equal to the torsional resonance frequency of the first vibration system, the coil 15 can greatly swing the movable plate 31 by the resonance vibration.

  On the other hand, the second voltage waveform 38 causes the one end (N pole) of the permanent magnet 28 to be attracted to the coil 15 and the other end (S pole) of the permanent magnet 28 is separated from the coil 15. Will occur. This magnetic field is referred to as a “third magnetic field”. When a voltage opposite to the third magnetic field is applied to the coil 15, one end (N pole) of the permanent magnet 28 is separated from the coil 15 and the other end (S pole) of the permanent magnet 28 is applied to the coil 15. A magnetic field to be attracted is generated. This magnetic field is referred to as a “fourth magnetic field”. When a voltage indicated by the second voltage waveform 38 is applied to the coil 15, the magnetic field generated in the coil 15 is switched alternately between the third magnetic field and the fourth magnetic field.

  In this way, the third magnetic field and the fourth magnetic field are alternately switched, so that the displacement portion 25 together with the movable plate 31 and the second voltage waveform 38 are torsionally deforming the third shaft portion 23 and the fourth shaft portion 24. Oscillates with the horizontal axis 11 as the rotation axis at a frequency of The frequency of the second voltage waveform 38 is set to be extremely lower than the frequency of the first voltage waveform 37. The torsional resonance frequency of the second vibration system is set lower than the torsional resonance frequency of the first vibration system. For this reason, the movable plate 31 is prevented from swinging around the vertical axis 12 as the rotation axis at the frequency of the second voltage waveform 38.

  The optical scanner 5 outputs a voltage obtained by superimposing the first voltage waveform 37 and the second voltage waveform 38 to the coil 15. As a result, the movable plate 31 is swung around the vertical axis 12 at the frequency of the first voltage waveform 37 and is swung around the horizontal axis 11 at the frequency of the second voltage waveform 38. Then, the movable plate 31 is swung around the horizontal axis 11 and the vertical axis 12, and the drawing laser beam 3 reflected by the reflection film 32 is two-dimensionally scanned. Further, since the coil 15 is separated from the structure 18 of the optical scanner 5, it is possible to prevent the heat generated by the coil 15 from adversely affecting the structure 18.

  The control unit 7 has a function of controlling the operations of the drawing light source unit 4 and the optical scanner 5. Specifically, the control unit 7 drives the optical scanner 5 to swing the movable plate 31 about the horizontal axis 11 and the vertical axis 12 as rotation axes. Further, the controller 7 emits the drawing laser beam 3 from the drawing light source unit 4 in synchronization with the swing of the movable plate 31. The control unit 7 includes an interface (not shown), and the control unit 7 inputs image data transmitted from an external computer via the interface. Based on the image data, the controller 7 emits laser beams 3r, 3g, and 3b having a predetermined intensity from the laser light sources 8r, 8g, and 8b at a predetermined timing. Thereby, the optical scanner 5 emits the drawing laser beam 3 having a predetermined color and light intensity at a predetermined timing. As a result, an image corresponding to the image data is displayed on the screen 2.

  FIG. 5 is a schematic diagram for explaining the operation of the displacement portion. FIG. 5A is a diagram when the displacement portion 25 rotates clockwise about the horizontal axis 11 as a rotation axis. FIG.5 (b) is a figure when the displacement part 25 becomes horizontal. FIG. 5C is a diagram when the displacement portion 25 rotates counterclockwise with the horizontal axis 11 as the rotation axis.

  When the voltage application unit 16 energizes the coil 15 to drive the permanent magnet 28, the displacement unit 25 is affected by the second voltage waveform 38. And the displacement part 25 makes the 3rd axis | shaft part 23 and the 4th axis | shaft part 24 into a rotating shaft, FIG. 5 (a), FIG.5 (b), FIG.5 (c), FIG. Swings in the order indicated by a).

  One end of the first shaft portion 29 and the second shaft portion 30 supports the movable plate 31, and the other end of the first shaft portion 29 and the second shaft portion 30 is connected to the displacement portion 25. The displacement portion 25 is supported by the third shaft portion 23 and the fourth shaft portion 24. The direction in which the first shaft portion 29 and the second shaft portion 30 extend is perpendicular to the direction in which the third shaft portion 23 and the fourth shaft portion 24 extend. The movable plate 31 swings around the axis of the vertical shaft 12, and the displacement portion 25 swings around the axis of the horizontal shaft 11. Therefore, the movable plate 31 swings around two orthogonal axes.

  A permanent magnet 28 is fixed to the displacement portion 25. And the coil 15 which drives the displacement part 25 by making a magnetic field act on the permanent magnet 28 is installed. By energizing the coil 15 and driving the displacement unit 25, the optical scanner 5 can swing the movable plate 31 having the reflective surface 5a around two intersecting axes.

  The displacement part 25 includes a thick frame part 25b and a thin first thin plate structure part 25a. The frame portion 25 b is close to the third shaft portion 23 and the fourth shaft portion 24, and the first thin plate structure portion 25 a is located at a position away from the third shaft portion 23 and the fourth shaft portion 24. Therefore, the displacement portion 25 of the optical scanner 5 has a smaller moment of inertia than when the thickness of the first thin plate structure portion 25a is the same as that of the frame portion 25b. The smaller the moment of inertia of the displacement unit 25 is, the smaller the power consumed to drive the displacement unit 25 can be. Therefore, the power consumed to drive the optical scanner can be reduced.

  When the displacement part 25 swings around the axis of the third shaft part 23 and the fourth shaft part 24, the frame part 25b and the first thin plate structure part 25a generate an air flow 41 around. The first thin plate structure 25a functions as a damper whose rotational speed is attenuated by the airflow 41. Thereby, the displacement part 25 can be made hard to react with the drive of the 1st voltage waveform 37 with a high frequency. Therefore, when the displacement part 25 swings around the third shaft part 23 and the fourth shaft part 24, the displacement part 25 can be made less susceptible to the drive of the first voltage waveform 37 having a high frequency. . As a result, the vibration performance of the movable plate 31 can be improved. In other words, the displacement portion 25 is swung corresponding to the first voltage waveform 37 around the vertical axis 12 and the displacement portion 25 is swung corresponding to the second voltage waveform 38 around the horizontal axis 11. Can be made. When the displacement portion 25 is swung around the horizontal axis 11, the displacement portion 25 can be swung so as not to correspond to the first voltage waveform 37.

  6 and 7 are schematic views for explaining a method of manufacturing the optical scanner. Next, a method for manufacturing the optical scanner 5 will be described with reference to FIGS. First, the structure 18 is manufactured. As shown in FIG. 6A, a laminated substrate 46 in which a resist layer 42, a first silicon layer 43, an oxide film 21a, a second silicon layer 44, and a mask oxide film 45 are laminated is prepared from the upper side in the drawing. The oxide film 21a and the mask oxide film 45 are layers made of silicon dioxide. The thickness of each layer is not particularly limited. For example, in this embodiment, the first silicon layer 43 is about 40 μm, the oxide film 21a is about 0.5 μm, the second silicon layer 44 is about 250 μm, and the mask oxide film 45 is 0. The thickness is about 5 μm.

  Next, the resist layer 42 and the mask oxide film 45 are patterned. The resist layer 42 is patterned into the shape of the movable plate 31, the first shaft portion 29, the second shaft portion 30, the plate-like member 26, the third shaft portion 23, the fourth shaft portion 24, and the support portion 22. The mask oxide film 45 is patterned into the shape of the support connecting portion 21 and the magnet support portion 27.

  Next, as shown in FIG. 6B, the first silicon layer 43 is dry-etched using the resist layer 42 as a mask. By this etching, the movable plate 31, the first shaft portion 29, the second shaft portion 30, the plate member 26, the third shaft portion 23, the fourth shaft portion 24, and the support portion 22 are formed.

  Next, as shown in FIG. 6C, the second silicon layer 44 is etched by using an etching method such as dry etching. At this time, the mask oxide film 45 is used as a mask. And the support connection part 21 and the magnet support part 27 are formed. Next, as shown in FIG. 6D, the exposed portion of the oxide film 21a and the mask oxide film 45 are removed by etching. Further, the resist layer 42 is peeled and removed.

  Next, as shown in FIG. 7A, a reflective film 32 is formed on the movable plate 31. The material of the reflective film 32 is formed by a method such as vapor deposition or sputtering. The movable plate 31 may be polished to a mirror surface before the reflective film 32 is formed. Thereby, the drawing laser beam 3 can be reflected at an accurate angle. The step of polishing the movable plate 31 to have a mirror surface is not particularly limited, but is preferably performed before the resist layer 42 is installed. The movable plate 31 can be polished without damaging the first shaft portion 29 and the second shaft portion 30.

  Next, as shown in FIG. 7B, the permanent magnet 28 is bonded and fixed to the magnet support portion 27. When forming a plurality of structures 18 on a single silicon wafer, the structures 18 are cut out using a method such as dicing. Thus, the structure 18 of the optical scanner 5 is obtained.

  Next, as shown in FIG. 7C, a housing 13 having a magnetic core 14 and a coil 15 installed on a bottom plate 13a is prepared. The magnetic core 14 and the coil 15 can be bonded to the housing 13 using an adhesive. Next, the casing 13 and the support connecting portion 21 are overlapped and bonded. Thus, the optical scanner 5 is completed.

As described above, this embodiment has the following effects.
(1) According to this embodiment, the displacement part 25 is provided with the frame part 25b and the 1st thin plate structure part 25a. The frame portion 25 b maintains the relative positions of the first shaft portion 29 and the second shaft portion 30 and the third shaft portion 23 and the fourth shaft portion 24. The first thin plate structure portion 25a extends in a direction orthogonal to the direction in which the third shaft portion 23 and the fourth shaft portion 24 extend. When the displacement part 25 swings around the horizontal axis 11, the first thin plate structure part 25a generates an air flow 41 around and functions as a damper. Thereby, the displacement part 25 can be made hard to react with respect to the drive with a high frequency. Therefore, when the displacement part 25 swings around the axis of the horizontal axis 11, it can be made difficult to react to a drive with a high frequency. As a result, the vibration performance of the reflecting surface 5a can be improved.

(2) According to this embodiment, the displacement part 25 is provided with the 2nd thin plate structure part 26a following the frame part 25b. Since the second thin plate structure portion 26a is thinner than the frame portion 25b, it is easier to deform than the frame portion 25b. And the 3rd axial part 23 and the 4th axial part 24 are connected to the 2nd thin plate structure part 26a in the connection part 26b. Accordingly, when the third shaft portion 23 and the fourth shaft portion 24 are twisted than when the third shaft portion 23 and the fourth shaft portion 24 are connected to the frame portion 25b, the displacement portion 25, the third shaft portion 23 and the fourth shaft portion 24 are twisted. The shaft portion 24 can make it difficult for stress concentration to occur in the connection portion 26b.
Furthermore, the connection part 26b which the 3rd axial part 23 and the 4th axial part 24, and the 2nd thin plate structure part 26a connect is circular arc shape. Therefore, when the third shaft portion 23 and the fourth shaft portion 24 are twisted, the displacement portion 25 can make it difficult for stress concentration to occur in the connection portion 26b.

(3) According to this embodiment, the displacement part 25 is comprised from the frame part 25b and the 1st thin plate structure part 25a. And the 1st thin plate structure part 25a is plate shape thinner than the frame part 25b.
Therefore, the moment of inertia of the displacement part 25 can be made smaller than when the displacement part 25 is entirely composed of the thickness of the frame part 25b. As a result, the displacement portion 25 can be swung with a small amount of energy, so that the power consumed by the coil 15 can be reduced.

(Second Embodiment)
Next, an embodiment of the optical scanner will be described with reference to a schematic plan view showing the structure of the optical scanner in FIG. 8A and a schematic side sectional view showing the structure in FIG. This embodiment is different from the first embodiment in that the shape of the reflector 33 shown in FIGS. 2 and 3 is different. Note that description of the same points as in the first embodiment is omitted.

  That is, in the present embodiment, as shown in FIG. 8, the optical scanner 49 includes a housing 13 in which a magnetic core 14 and a coil 15 are installed on a bottom plate 13a. A structure 50 is installed on the side plate 13 b of the housing 13. The structure 50 includes a support connecting portion 21 connected to the side plate 13b, and an oxide film 21a is provided on the surface of the support connecting portion 21 facing the Z direction. A support portion 22 is installed on the Z direction side of the support connecting portion 21.

  In the support portion 22, a third shaft portion 51 and a fourth shaft portion 52 as second torsion bar spring portions extending in the X direction are installed at the center in the Y direction. A displacement portion 53 is installed between the third shaft portion 51 and the fourth shaft portion 52. The displacement part 53 has a rectangular frame shape and is a rectangle that is long in the Y direction. The length of the displacement part 53 in the X direction is shorter than that of the displacement part 25 of the first embodiment. The length of the displacement part 53 in the Y direction is shorter than that of the displacement part 25 of the first embodiment.

  The displacement part 53 includes a plate-like member 54 and a magnet support part 55. A portion of the displacement portion 53 located on the Y direction side from the magnet support portion 55 is defined as a first thin plate structure portion 53a. Further, a portion of the displacement portion 53 that is located on the −Y direction side from the magnet support portion 55 is also referred to as a first thin plate structure portion 53a. And the part inside the magnet support part 55 including the magnet support part 55 is made into the frame part 53b. The frame portion 53 b is constituted by a part of the plate-like member 54 and a magnet support portion 55. The thickness of the first thin plate structure portion 53a is thinner than the thickness of the frame portion 53b. A permanent magnet 28 is installed on the side of the magnetic core 14 of the magnet support portion 55.

  In the center of the displacement portion 53 in the X direction, a first shaft portion 56 and a second shaft portion 57 are installed as first torsion bar spring portions extending in the Y direction. A movable plate 58 is installed between the first shaft portion 56 and the second shaft portion 57. The movable plate 58 has a circular plate shape, and the size of the movable plate 58 is smaller than the movable plate 31 in the first embodiment. Thereby, the plate-shaped member 54 and the displacement part 53 can shorten the length of a X direction.

  A light reflecting portion 59 is installed on the movable plate 58. The light reflecting portion 59 includes a column portion 60 and a reflecting plate 61. The support column 60 is installed on the movable plate 58, and the reflection plate 61 is installed on the support column 60. A reflective film 32 is provided on the surface of the reflective plate 61 on the Z direction side, and the surface of the reflective plate 61 on the Z direction side is a reflective surface 5a. The reflection plate 61 is installed at a distance from the displacement portion 53 in the Z direction. A part of the reflection plate 61 is arranged so as to overlap the magnet support portion 55 in a plan view of the reflection plate 61 viewed from the Z direction.

  A hole located on the X direction side of the first shaft portion 56 and the second shaft portion 57 in the displacement portion 53 is referred to as a first hole 53c, and a hole located on the −X direction side of the first shaft portion 56 and the second shaft portion 57. Is the second hole 53d. A plate-like member 54 surrounding the first hole 53 c and the second hole 53 d is a part of the displacement portion 53. In a plan view as viewed from the Z direction, the reflector 61 projects in the X direction from the first hole 53c, and projects in the −X direction from the second hole 53d. That is, a part of the reflector 61 is arranged so as to overlap the displacement portion 53 in a plan view as viewed from the Z direction. The diameter of the reflecting plate 61 is the same as that of the movable plate 31 in the first embodiment. The movable plate 58 and the light reflecting portion 59 constitute a reflector 62.

  As the displacement portion 53 has a shorter length in the X direction, it is possible to improve responsiveness to high-frequency driving in swinging around the vertical axis 12. Thereby, the control unit 7 can swing the displacement unit 53 with high responsiveness to high-frequency driving around the vertical axis 12. Since the frequency of the first voltage waveform 37 matches the torsional resonance frequency of the first vibration system formed by the movable plate 58, the first shaft portion 56, the second shaft portion 57, and the light reflecting portion 59, the displacement As the portion 53 swings around the vertical axis 12, the movable plate 58 and the light reflecting portion 59 can be swung.

  Although the dimension of each member is not specifically limited, In this embodiment, for example, the dimension of each part is set to the following value. The optical scanner 49 has a length in the X direction of 3070 μm and a length in the Y direction of 3240 μm. The length of the support connecting portion 21 in the Z direction is 250 μm. The width of the support portion 22 is 500 μm. The inner hole of the support portion 22 has a length in the X direction of 2070 μm and a length in the Y direction of 2240 μm.

  The displacement part 53 has a length in the X direction of 1000 μm and a length in the Y direction of 2140 μm. The thickness of the plate member 54 in the Z direction is 40 μm. The length from the end on the + X direction side of the first hole 53c to the end on the −X direction side of the second hole 53d is 400 μm. The length of the first hole 53c and the second hole 53d in the Y direction is 840 μm. The length from the end on the Y direction side of the first hole 53c and the second hole 53d to the magnet support portion 55 on the Y direction side is 65 μm. The width of the magnet support portion 55 on the Y direction side is 150 μm. The length from the end of the magnet support portion 55 on the Y direction side to the end of the displacement portion 53 on the Y direction side is 435 μm. Therefore, the length from the end in the Y direction of the first hole 53c and the second hole 53d to the end in the Y direction of the plate member 54 is 650 μm.

  The diameter of the column 60 is 270 μm. The reflector 61 has a diameter of 1000 μm and a thickness of 40 μm. The permanent magnet 28 has a length of 1000 μm and a width of 500 to 800 μm.

As described above, this embodiment has the following effects.
(1) According to this embodiment, the reflecting plate 61 and the displacement part 53 are installed at intervals in the Z direction. A part of the reflection plate 61 overlaps the displacement portion 53 in a plan view of the reflection plate 61 viewed from the Z direction. With this configuration, the displacement portion 53 can be made shorter than when the reflector 61 and the displacement portion 53 are located on the same plane. Therefore, since the displacement part 53 becomes short, the responsiveness of the movable plate 58 and the light reflection part 59 can be improved with respect to high frequency driving.

(Third embodiment)
Next, an embodiment of the optical scanner will be described with reference to a schematic plan view showing the structure of the optical scanner in FIG. 9A and a schematic side sectional view showing the structure in FIG. This embodiment is different from the first embodiment in that weights are installed at both ends of the displacement portion 25. Note that description of the same points as in the first embodiment is omitted.

  That is, in the present embodiment, as shown in FIG. 9, the structure 66 of the optical scanner 65 is provided with weight portions 67 at the end on the Y direction side and the end on the −Y direction side in the first thin plate structure portion 25a. At the place where the weight portion 67 is installed, the thickness of the first thin plate structure portion 25a is increased because the thickness of the weight portion 67 is added to the thickness of the plate member 26. That is, the thickness of the first thin plate structure portion 25a is thicker at a location away from the location near the third shaft portion 23 and the fourth shaft portion 24.

  The displacement part 25 can increase the moment of inertia around the horizontal axis 11 as compared with the case where the thickness of the first thin plate structure part 25a away from the horizontal axis 11 is thin. Thereby, the displacement part 25 can be made hard to react with respect to the drive with a high frequency. Therefore, when the displacement part 25 swings around the horizontal axis 11, it is possible to make it difficult to react to a drive with a high frequency. As a result, the vibration performance of the movable plate 31 can be improved.

  The place where the weight part 67 of the first thin plate structure part 25a is installed is installed on the surface of the displacement part 25 opposite to the side where the permanent magnet 28 is installed. That is, the weight part 67 is installed on the Z direction side of the displacement part 25.

  Thereby, the gravity center of the displacement part 25 can be brought close to the axis of the second torsion bar spring part. Therefore, the combined stress due to the torsional stress and the bending stress applied to the second torsion bar spring portion can be reduced, and the reliability against the fracture of the beam can be enhanced.

  Although the dimension of the weight part 67 is not specifically limited, In this embodiment, the dimension of the weight part 67 is set to the following value, for example. The weight 67 has a length in the Y direction of 50 μm to 100 μm and a length in the Z direction of 200 μm to 300 μm.

(Fourth embodiment)
Next, an embodiment of the optical scanner will be described with reference to a schematic plan view illustrating the structure of the optical scanner in FIG. 10A and a schematic side sectional view illustrating the structure in FIG. This embodiment is different from the third embodiment in that the surface of the displacement portion 25 on which the weight portion 67 is installed is different. The description of the same points as in the third embodiment will be omitted.

  That is, in this embodiment, as shown in FIG. 10, the structure 71 of the optical scanner 70 is provided with weight portions 72 at the Y-direction end and the −Y-direction end in the first thin plate structure portion 25a. The place where the weight part 72 of the first thin plate structure part 25a is installed is installed on the same side of the displacement part 25 as the side where the permanent magnet 28 is installed. That is, the weight portion 72 is installed on the −Z direction side of the displacement portion 25. And the length of the Z direction of the support connection part 21, the magnet support part 27, and the weight part 72 is the same length, and is the same material.

Accordingly, the support connecting portion 21, the magnet support portion 27, and the weight portion 72 can be formed by etching in the same process. Accordingly, the optical scanner 70 can be easily manufactured.
Although the dimension of the weight part 72 is not specifically limited, In this embodiment, the length of the Y direction of the weight part 72 is 50 micrometers-100 micrometers, for example.

(Fifth embodiment)
Next, an embodiment of a head-up display using an optical scanner will be described with reference to FIG. The image display apparatus 1 in the first embodiment is utilized for the head-up display of the present embodiment. Note that description of the same points as in the first embodiment is omitted.

  FIG. 11 is a schematic perspective view showing a head-up display. As shown in FIG. 11, in the head-up display system 75, the image display device 1 is mounted on the dashboard of the automobile so as to form a head-up display 76. With this head-up display 76, a predetermined image such as a guidance display to the destination can be displayed on the windshield 77, for example. Note that the head-up display system 75 can be applied not only to automobiles but also to aircrafts, ships, and the like.

  In the optical scanner 5 installed in the image display device 1, the first thin plate structure portion 25a generates an air flow 41 around and functions as a damper. As a result, it is possible to make it difficult for the swing of the displacement portion 25 around the horizontal axis 11 to react to high frequency driving. Therefore, when the reflecting surface 5a swings around the horizontal axis 11, it is possible to make it difficult to respond to high frequency driving. The head-up display system 75 includes the optical scanner 5 with good vibration performance and can display an easy-to-see image.

(Sixth embodiment)
Next, an embodiment of a head mounted display using an optical scanner will be described with reference to FIG. The image display apparatus 1 in the first embodiment is utilized for the head mounted display of the present embodiment. Note that description of the same points as in the first embodiment is omitted.

  FIG. 12 is a schematic perspective view showing a head mounted display. As shown in FIG. 12, the head mounted display 79 includes a frame 80 attached to the observer's head and the image display device 1 mounted on the frame 80. Then, the image display device 1 displays a predetermined image that is visually recognized by one eye on the display unit 81 provided in a portion that is originally a lens of the frame 80. Alternatively, the drawing laser beam 3 may be reflected on the display unit 81 to form a virtual image on the observer's retina.

  The display unit 81 may be transparent or opaque. When the display unit 81 is transparent, an observer can see the scenery seen through the display unit 81 and the information from the image display device 1 in an overlapping manner. The display unit 81 only needs to reflect at least part of the incident light. For example, a half mirror or the like can be used for the display unit 81. It should be noted that two image display devices 1 may be provided on the head mounted display 79 and images may be displayed on the two display units so as to be viewed with both eyes.

  The manufacturing method of the optical scanner 5, the image display device 1, the head-up display 76, the head mounted display 79, and the optical scanner 5 has been described above, but the present invention is not limited to this, and the configuration of each part is the same. It can be replaced with any configuration having the above function. In addition, any other component may be added to the present invention. A modification will be described below.

(Modification 1)
In the first embodiment, the movable plate 31 has a circular shape in a plan view as viewed from the Z direction. However, the planar view shape of the movable plate 31 is not limited to this, and may be, for example, an ellipse, a triangle, or a quadrangle. It may be a polygon such as. The shape may be easily manufactured.

(Modification 2)
In the first embodiment, the direction in which the first shaft portion 29 and the second shaft portion 30 extend is orthogonal to the direction in which the third shaft portion 23 and the fourth shaft portion 24 extend. The direction in which the first shaft portion 29 and the second shaft portion 30 extend may intersect with the direction in which the third shaft portion 23 and the fourth shaft portion 24 extend obliquely. Also at this time, it is possible to draw a two-dimensional image using the drawing laser beam 3 by swinging the reflecting surface 5a.

(Modification 3)
In the third embodiment, the weight portion 67 is installed on the Z side of the displacement portion 25. In the fourth embodiment, the weight portion 72 is installed on the −Z side of the displacement portion 25. A weight portion may be provided on both the Z side and the −Z side of the displacement portion 25. You may adjust according to operation | movement of the displacement part 25. FIG.

  Further, in the optical scanner 49 provided with the light reflecting portion 59 in the second embodiment, the weight portion 67 may be provided on the Z side of the displacement portion 53. Further, in the optical scanner 49, the weight portion 72 may be installed on the −Z side of the displacement portion 53. A weight portion may be provided on both the Z side and the −Z side of the displacement portion 53. You may adjust according to operation | movement of the displacement part 53. FIG.

(Modification 4)
In the fifth embodiment and the sixth embodiment, the optical scanner 5 is used for the image display device 1. Instead of the optical scanner 5, an optical scanner 49, an optical scanner 65, or an optical scanner 70 may be used. Even at this time, a high-quality image can be drawn.

  DESCRIPTION OF SYMBOLS 1 ... Image display apparatus, 3 ... Drawing laser beam as light, 5a ... Reflecting surface as light reflection part, 8b, 8g, 8r ... Laser light source as light source, 11 ... Horizontal axis as 2nd axis, 12 ... vertical axis as first axis, 15 ... coil, 22 ... support part, 23 ... third axis part as second torsion bar spring part, 24 ... fourth axis part as second torsion bar spring part, 25a ... 1st thin plate structure part as a damper part, 25, 53 ... Displacement part, 26a ... 2nd thin plate structure part as a thin plate structure part, 26b ... Connection part, 27 ... Magnet support part as a frame part, 28 ... Permanent magnet , 29: a first shaft portion as a first torsion bar spring portion, 30: a second shaft portion as a first torsion bar spring portion, 31, 58 ... a movable plate, 32 ... a reflection film as a light reflection portion, 59 ... Light reflection part, 60 ... post part, 61 ... reflection plate, 76 ... head up display Lee, 77 ... front glass, 80 ... frame.

Claims (7)

A movable plate having a light reflecting portion;
A first torsion bar spring portion supporting the movable plate so as to be swingable about a first axis;
A displacement portion connected to the first torsion bar spring portion;
A second torsion bar spring portion supporting the displacement portion so as to be swingable about a second axis intersecting the first axis;
A permanent magnet provided in the displacement portion so that a line segment connecting one magnetic pole and the other magnetic pole is inclined with respect to the first axis and the second axis;
A coil that is provided apart from the displacement part and generates a magnetic field that acts on the permanent magnet,
The said displacement part is a damper part in each of the edge | side of the one end side which cross | intersects said 1st axis | shaft among the edge | sides of the said displacement part, and the edge | side of the other end side located on the opposite side to the said one end side. With
The frequency at which the movable plate swings is higher than the frequency at which the displacement portion swings .   The optical scanner according to claim 1.
  The movable plate and the first torsion bar spring portion constitute a first vibration system,
  The movable plate, the first torsion bar spring part, the displacement part, the second torsion bar spring part and the permanent magnet constitute a second vibration system,
  The optical scanner according to claim 1, wherein a resonance frequency of the first vibration system is higher than a resonance frequency of the second vibration system.   The optical scanner according to claim 1 or 2,
  A voltage application unit electrically connected to the coil;
  The said voltage application part superimposes a 1st voltage waveform and a 2nd voltage waveform whose frequency is lower than the said 1st voltage waveform, and applies it to the said coil, The optical scanner characterized by the above-mentioned.   The optical scanner according to claim 3.
  The optical scanner according to claim 1, wherein the first voltage waveform has a frequency between 10 kHz and 40 kHz.   The optical scanner according to claim 3 or 4,
  The optical scanner, wherein the second voltage waveform has a frequency between 30 Hz and 120 Hz.   The optical scanner according to any one of claims 3 to 5,
  The optical scanner includes: a first voltage generation unit that generates the first voltage waveform; and a second voltage generation unit that generates the second voltage waveform.   A head-mounted display, comprising: the optical scanner according to claim 1; and a frame that is attached to an observer's head.

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