JP2010197662A - Optical reflection element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress damage of an optical reflection element. <P>SOLUTION: The optical reflection element includes: a mirror part 1, a movable frame 3 that is connected to a mirror part 1 via a first beam 2 and surrounds the outer periphery of the first beam 2 and the mirror part 1; a support body 5 connected to the movable frame 3 via a second beam 4; a driving means for repetitively rotating and vibrating the mirror part 1 around each of the center axes of the first beam 2 and the second beam 4; and a suppressing means for suppressing vibration of at least one of the X-axis direction and Y-axis direction of the movable frame 3. Thus, excessive amplitude of the movable frame 3 can be suppressed, and the damage of the optical reflection element can be suppressed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical reflection element used for a head-up display device, a head-mounted display device, or the like.

  The conventional optical reflecting element is connected to the mirror portion, the mirror portion and the first beam via a movable frame surrounding the first beam and the outer periphery of the mirror portion, and the movable frame and the second beam. And a supported support. The first beam has a central axis in the Y-axis direction and the second beam has a central axis in the X-axis direction, and has driving means for repeatedly rotating and vibrating the mirror portion around these central axes.

  In this optical reflecting element, the mirror part and the movable frame are mass bodies, and these mass bodies are vibrated by torsional vibration or swinging of the first beam or the second beam.

As prior art document information similar to this application, for example, Patent Document 1 is known.
JP 2008-040240 A

  Conventional optical reflective elements may be damaged when subjected to disturbance vibrations or external impacts.

  The reason is that when the optical reflection element resonates with disturbance vibrations or receives an impact from the outside, the movable frame greatly swings. Then, the second beam is deformed according to the amplitude of the movable frame, and when the allowable range of deformation is exceeded, the second beam is damaged and the element is destroyed.

  Accordingly, an object of the present invention is to suppress damage to the optical reflection element.

  In order to achieve this object, the present invention includes suppression means for suppressing the amplitude of at least one of the movable frame in the X-axis direction or the Y-axis direction and / or the Z-axis direction.

  Thereby, this invention can suppress damage to an optical reflective element.

  The reason is that the excessive amplitude of the movable frame can be suppressed.

  Therefore, deformation of the second beam can be suppressed, and as a result, damage to the optical reflecting element can be suppressed.

(Embodiment 1)
As shown in FIG. 1, the optical reflecting element in the present embodiment is opposed to the mirror unit 1 via the mirror unit 1, and a pair of end portions of the mirror unit 1 and one end thereof are connected to each other. The first beam 2 is connected to the other end of the first beam 2 and is opposed to the movable frame 3 that surrounds the outer periphery of the first beam 2 and the mirror portion 1. A pair of second beams 4 each having one end connected to the movable frame 3, and a frame shape that is connected to the other ends of the second beams 4 and surrounds the outer periphery of the second beams 4 and the movable frame 3. And a support 5.

  The optical reflecting element has a reflecting surface on the XY plane of the mirror unit 1.

  Further, the pair of first beams 2 extends in the Y-axis direction of FIG. These first beams 2 have a common central axis S1 that is substantially parallel to the Y axis and passes through the approximate center of the mirror portion 1, and a plurality of diaphragms 6 that intersect the central axis S1 are the same. It is a meander shape that is folded and connected on a plane.

  The pair of second beams 4 extends in the X-axis direction in FIG. These second beams 4 are substantially parallel to the X-axis and have a common central axis S2 that passes through substantially the center of the mirror portion 1, and a plurality of diaphragms 7 that intersect the central axis S2 are the same. It is a meander shape that is folded and connected on a plane. Thus, by making the 1st beam 2 and the 2nd beam 4 into a meander shape, a beam becomes easy to elastically deform and a large amplitude can be obtained efficiently. Further, by making the first beam 2 and the second beam 4 meander, it contributes to the miniaturization of the element.

  The central axis S1 and the central axis S2 are orthogonal to each other at substantially the center of the mirror unit 1. The pair of first beams 2 is line symmetric with respect to the central axis S2, and the pair of second beams 4 is line symmetric with respect to the central axis S1.

  Further, in the present embodiment, as a suppressing means for suppressing the vibration in the horizontal direction of the movable frame 3, a pair of recesses 8 provided at both ends in the Y-axis direction on the outer periphery of the movable frame 3 and the support 5 are provided. A pair of convex portions 9 is provided that protrudes into the concave portion 8 and fits with the concave portion 8 at a predetermined interval in a static state. The convex portion 9 preferably protrudes in a direction perpendicular to the X-axis direction (the central axis S2 direction) in FIG. 1, whereby the vibration of the movable frame 3 in the X-axis direction can be suppressed. Furthermore, it is preferable to arrange the convex portion 9 on the central axis S1, thereby suppressing the amplitude of the movable frame 3 in the Y-axis direction (the central axis S1 direction) above a certain level, and the center of the movable frame 3 being Positioning can be performed on the central axis S1. The movable frame 3 and the mirror unit 1 can be repeatedly rotated and vibrated with the center of gravity at the substantially center of the mirror unit 1 as a fixed point, and an image can be projected with high accuracy.

  In the present embodiment, each of the first beam 2 and the second beam 4 includes a piezoelectric element (10 in FIG. 2B) disposed on the plurality of diaphragms 6 and 7 as driving means. As shown in FIG. 2B, the piezoelectric element 10 has a laminated structure in which a ground electrode 12, a piezoelectric body 13, a drive electrode 14A or a ground electrode 12, a piezoelectric body 13, and a drive electrode 14B are laminated in this order on a substrate 11. is there. 2A and 2B show the first beam 2, the second beam 4 also has a piezoelectric element 10 having a similar laminated structure.

  Here, examples of the material of the substrate 11 include metals such as silicon, glass, quartz, and stainless steel. In this embodiment, silicon suitable for fine processing is used. An insulating layer 15 such as silicon dioxide is preferably formed on the surface layer. The ground electrode 12 is preferably platinum or the like from the viewpoint of enhancing the crystal orientation of the piezoelectric body 13, and the piezoelectric body 13 may be lead zirconate titanate having high piezoelectric characteristics. The drive electrodes 14A and 14B can be formed of gold or the like.

  The ground electrode 12, the piezoelectric body 13, and the drive electrodes 14A and 14B can be formed by sputtering or CVD, respectively. The base substrate 11 can be processed into a desired shape by a thin film forming technique such as wet etching or dry etching.

  The operation of the optical reflecting element in the present embodiment will be described below.

  First, a voltage having a vibration frequency specific to the first beam 2 is applied to the drive electrodes 14 </ b> A and 14 </ b> B on the first beam 2. At this time, if the two independent drive electrodes 14A and 14B are alternately arranged on the diaphragm 6 of FIG. 1 and an AC voltage having an opposite phase is applied, the diaphragm 6 bends and vibrates in the opposite direction. As shown in FIG. 3, the displacement is accumulated according to the number of diaphragms around the central axis S1. Due to the amplitude of the first beam 2, the end of the mirror portion 1 vibrates in the thickness direction, that is, the Z-axis direction perpendicular to the X-axis and the Y-axis, and the mirror portion 1 is largely repeated around the central axis S1. It can be rotated and vibrated.

  Similarly, a voltage having a vibration frequency specific to the second beam 4 is applied to the drive electrode on the second beam 4. At this time, by alternately applying AC voltages having opposite phases to the plurality of diaphragms 7, displacement is accumulated according to the number of diaphragms around the central axis S <b> 2. And the edge part of the movable frame 3 vibrates in the thickness direction (Z-axis direction), and this movable frame 3 and the mirror part 1 can be largely repetitively rotationally oscillated around the central axis S2.

  In the present embodiment, the size of the mirror unit 1 is about 1 mm × 1 mm, and the length of the movable frame 3 in the Y-axis direction is about 5.5 mm. The first beam 2 and the second beam 4 have different resonance drive frequencies, and the frequency ratio is about 10 to 100 times. For example, in the present embodiment, the resonance frequency of the first beam 2 is 10 kHz, the resonance frequency of the second beam 4 is about 200 Hz, and the amplitude angle is about ± 10 °. By increasing the drive frequency ratio between the first beam 2 and the second beam 4 in this way, the scanning accuracy is increased and a highly accurate image can be projected.

  Here, since the movable frame 3 is a mass body, the second beam 4 can be driven at a lower frequency by increasing the movable frame 3 or increasing the thickness. In this embodiment, the thickness of the mirror frame 1, the first beam 2 and the second beam 4 in the Z-axis direction is 100 μm, respectively, whereas the movable frame 3 and the support 5 are as thick as 575 μm. Moreover, since the movable frame 3 and the recessed part 8, and the support body 5 and the convex part 9 were each integrally molded, they were set to the same thickness.

  Also, by lengthening the second beam 4, the resonator length can be extended, and the driving can be performed at a lower frequency. However, as the mass of the movable frame 3 increases, the gravitational acceleration increases, and the amplitude when an excessive impact is applied also increases. Further, when the second beam 4 becomes longer, the load increases due to the lever principle, and the second beam 4 is easily damaged. However, in this embodiment, the damage can be suppressed by the vibration suppressing means described above. Details of this effect will be described later.

  In the present embodiment, voltages having opposite phases are alternately applied to the diaphragms 6 and 7, but they can be driven in the same manner even when voltages having the same phase are applied every other diaphragm. Even if the same phase voltage is applied to the diaphragms 6 and 7, the entire first beam 2 and the second beam 4 oscillate up and down, and the ends of the mirror unit 1 and the movable frame 3 oscillate up and down. As a result, the mirror unit can be repeatedly rotated and oscillated around the central axes S1 and S2. Further, the piezoelectric element 10 does not have to be formed directly on the first beam 2 and the second beam 4. For example, as shown in FIG. 4, the central axes S 1, S 2 and the outside of the substantially square support 5 It is also possible to provide a vibration part P having a bisector of the angle between them as the rotation axis S3 and arrange the piezoelectric element 10 on this vibration part P. At this time, a signal obtained by combining the drive signals of the first beam 2 and the second beam 4 is input to the piezoelectric element 10. In this case, the torsional excitation force about the rotation axis S3 is vector-decomposed and acts as a torsional excitation force about the center axis S1 and a torsional excitation force about the center axis S2. Therefore, the first beam 2 can be repeatedly rotated and oscillated around the central axis S1, and the second beam 4 can be rotated and oscillated around the central axis S2. Further, the shape of the first beam 2 and the second beam 4 may be other than the meander shape, and may be, for example, a linear shape. In the present embodiment, the piezoelectric driving method is exemplified as the driving means, but an electromagnetic driving method or an electrostatic driving method may be used.

  The effect of the optical reflecting element in the present embodiment will be described below.

  The optical reflecting element has the first beam 2, the second beam 4, the mirror unit 1, movable so that a predetermined amplitude can be obtained by vibrating the mirror unit 1 around the central axes S 1 and S 2 at a desired resonance frequency. Design the frame 3. However, when this optical reflective element is mounted on a vehicle, an unexpected impact may be applied to the optical reflective element due to the movement of the vehicle. Further, when the frequency of vibration transmitted from the outside to the optical reflection element matches the resonance frequency of the optical reflection element, the optical reflection element may vibrate greatly. Even in such cases, in the present embodiment, damage to the optical reflecting element can be suppressed and reliability can be improved.

  The reason is that the combination of the convex portion 9 and the concave portion 8 described above can suppress the movable frame 3 from being swung more than the amplitude necessary for driving the mirror portion 1 in the horizontal direction, that is, on the XY plane of FIG.

  In other words, the optical reflecting element has a relatively large mass in the X-axis direction when excessive shock or vibration is applied in the X-axis direction in FIG. Trying to violently swing in the X-axis direction. At this time, since the second beam 4 has a meander shape that is easily deformed, the second beam 4 is greatly deformed in accordance with the amplitude of the movable frame 3. If the deformation exceeds the allowable range, the second beam 4 will be broken. Such damage is caused by the end of the diaphragm 7 on the outermost side of the second beam 4 coming into contact with the support 5 or the end of the diaphragm 7 on the innermost side of the second beam 4 being movable. It is easy to generate by contacting 3.

  On the other hand, in the present embodiment, when the movable frame 3 tries to greatly swing in the X-axis direction, the convex portion 9 protruding from the support body 5 is caught in the concave portion 8 of the movable frame 3, so that excessive amplitude is suppressed. be able to. As a result, damage to the second beam 4 can be suppressed.

  As a result of the impact acceleration test in which gravitational acceleration is applied in the X-axis direction, the second beam 4 is damaged by 635G when the vibration suppressing means by the convex portion 9 and the concave portion 8 is not provided. Then, damage to the second beam 4 could be suppressed to about 1150G to 1210G.

  Furthermore, in this embodiment, even when an excessive impact is applied in the Y-axis direction in FIG. 1, the movable frame 3 is brought into contact with the concave portion 8 of the movable frame 3 and the convex portion 9 provided on the support 5. Large amplitude in the Y-axis direction can be suppressed. In this case, since it is necessary to make the convex portion 9 and the concave portion 8 contact each other before the second beam 4 is damaged, in the region where the convex portion 9 and the concave portion 8 are formed, the support 5 and the movable frame 3 are arranged. Is preferably narrower than the distance between the support 5 and the movable frame 3 in the region where the convex portion 9 and the concave portion 8 are not formed. In this Embodiment, as shown to Fig.5 (a)-(c), the space | interval of the convex part 9 and the recessed part 8 is 50 micrometers-150 micrometers, and the space | interval of the movable frame and support body in the outer periphery of this area | region ( It is narrower than 200 μm in FIGS.

  In the present embodiment, as a result of an impact acceleration test in which gravitational acceleration is applied in the Y-axis direction, damage to the second beam 4 can be suppressed to about 2200G to 3000G, and an optical reflective element with high mechanical reliability can be realized. It was.

  Here, when the second beam 4 has a meander shape as in the present embodiment, the amplitude in the X-axis direction becomes larger than the amplitude in the Y-axis direction due to elastic deformation. Therefore, as shown in FIG. 5C, the distance between the convex portion 9 and the concave portion 8 is 50 μm at the portion facing the X-axis direction, and is narrower than the space between the portions facing the Y-axis direction (100 μm). However, it is possible to further improve the impact resistance against gravitational acceleration in the X-axis direction.

  As described above, in this embodiment, an optical reflection element that can suppress any excessive amplitude in the X-axis direction and the Y-axis direction with a single vibration suppressing unit, and is highly reliable and excellent in productivity. Can be realized.

  Furthermore, in this embodiment, since the movable frame 3 and the support 5 are sufficiently thicker than the second beam 4, even when the movable frame 3 is inclined about 10 ° around the intersection of the central axes S1 and S2, the convexity A part of the part 9 is in a state of being fitted into the recess 8 with a predetermined interval. Therefore, even during the operation of the optical reflecting element, the strength can be increased against any excessive vibration or impact in the X-axis direction or the Y-axis direction.

When designing an optical reflecting element, the relationship between the thickness of the concave portion 8 and the movable frame 3 (referred to as x), the thickness of the convex portion 9 and the support 5 (referred to as y), and the maximum amplitude angle θ during operation is as follows. ,
y <x · tanθ / 2
If designed to be, the convex portion 9 and the concave portion 8 can be loosely fitted even during operation.

  Since the concave portions 8 are formed at both ends of the movable frame 3, if at least one of the concave portions 8 is loosely fitted to the convex portion 9 during operation of the optical reflective element, the optical reflective element is always operated during operation. The effect which suppresses breakage of the is obtained. Therefore, although the thickness of both the movable frame 3 and the support body 5 is increased in the present embodiment, the thickness of either the movable frame 3 or the support body 5 may be increased.

  That is, for example, when the movable frame 3 is thin and the support body 5 is formed thick, and the upper surface of the movable frame 3 and the support body 5 are flush with each other, one end of the movable frame 3 is more than the support body 5. Even if one concave portion 8 is tilted upward and separated from the convex portion 9, if the other end of the movable frame 3 exists inside the support body 5, the other concave portion 8 is connected to the other convex portion 9. It is in a loosely fitted state. Therefore, the excessive amplitude of the movable frame 3 can be suppressed even during operation.

  Further, in the present embodiment, since the convex portion 9 is formed integrally with the support 5, the productivity is high, and it is difficult to be damaged even when stress is applied, and the reliability of the optical reflecting element can be improved. .

  Furthermore, in the present embodiment, since the concave portion 8 and the convex portion 9 are formed on both ends of the movable frame 3, respectively, the amplitude of the movable frame 3 can be suppressed in a well-balanced manner.

  Further, in this embodiment, the silicon substrate 11 suitable for microfabrication is used in order to reduce the size of the element. However, since silicon has a cleavage property, it is easily damaged by excessive deformation. However, in the present embodiment, the damage can be reduced by the amplitude suppressing means including the convex portion 9 and the concave portion 8.

  As another example of the amplitude suppressing means, for example, as shown in FIG. 6, a pair of recesses 16 provided on the inner periphery of the support 5 and an outer periphery of the movable frame 3 are provided toward the recess 16. You may comprise by a pair of convex part 17 which protrudes outside and fits with the recessed part 16 and predetermined intervals. Thereby, the excessive amplitude of the movable frame 3 in the horizontal direction can be suppressed. If there is no recess 16, only the excessive amplitude in the Y-axis direction can be suppressed.

  However, as shown in FIG. 1, the mechanical strength of the entire optical reflecting element can be maintained by forming the convex portion 9 on the support 5. That is, the mechanical strength of the entire optical reflecting element is greatly influenced by the mechanical strength of the support 5 at the outermost periphery. However, when the recess 16 is formed in the support 5 as shown in FIG. The width | variety of the support body 5 becomes narrow and becomes easy to bend. Therefore, as shown in FIG. 1, the mechanical strength of the optical reflecting element can be further increased by providing the support 5 with the convex portion 9 and increasing the width of the support 5.

(Embodiment 2)
As shown in FIG. 7, the main difference between this Embodiment 1 and Embodiment 2 is an amplitude suppression means.

  The amplitude suppressing means in the present embodiment is provided on the support 5, and includes a convex portion 18 that protrudes inward and faces the movable frame at a predetermined interval. The convex portions 18 are provided so as to face the outer surfaces of the four corners of the movable frame 3, respectively, and are formed so that the respective tips enter the gaps between the movable frame 3 and the diaphragm 7.

  While driving at a desired driving frequency, the inner side surface of the convex portion 18 and the outer side surface of the movable frame 3 are opposed to each other with a predetermined interval. When vibration is applied, the inner side surface of the convex portion 18 and the outer side surface of the movable frame 3 come into contact with each other, and the convex portion 18 supports the movable frame 3. Therefore, excessive vibration amplitude in the X-axis direction of the movable frame 3 can be suppressed, and as a result, the reliability of the optical reflecting element can be improved.

  Note that the distance between the convex portion 18 and the movable frame 3 is determined in advance by measuring how much the movable frame 3 is amplituded and the second beam 4 is broken. Design to touch.

  Here, it is preferable to provide the convex portions 18 on a diagonal line. Furthermore, by making the four convex portions 18 face the four corners of the movable frame 3, the movable frame 3 can be supported more stably.

  As in the first embodiment, the thickness of either the movable frame 3 or the support 5 is set to the second beam 4 so that the convex frame 18 can support the movable frame 3 even during the operation of the optical reflecting element. Larger than that.

  Description of other configurations and effects similar to those of the first embodiment is omitted.

(Embodiment 3)
As shown in FIGS. 8A and 8B, the main difference between the present embodiment and the first embodiment is the amplitude suppression means.

  This amplitude suppressing means may be disposed between the movable frame 3 and the support 5, but in particular in the present embodiment, it is provided in the gap between the movable frame 3 and the diaphragm 7 closest to the movable frame 3. The film-shaped partition plate 19 is set up in the thickness direction (Z-axis direction) of the optical reflecting element. What is necessary is just to fix this film-shaped partition plate 19 to the package 20 etc. which include the whole support body 5 at the both ends.

  While driving at a desired drive frequency, the inner side surface of the partition plate 19 and the outer side surface of the movable frame 3 face each other with a predetermined interval, but in the X-axis direction shown in FIG. When an excessive impact or vibration is applied, the inner side surface of the partition plate 19 comes into contact with the outer side surface of the movable frame 3, and the partition plate 19 supports the movable frame 3. Therefore, the mechanical strength can be increased in the X-axis direction of the movable frame 3.

  In the present embodiment, the partition plate 19 is provided outside the side perpendicular to the X-axis direction of the movable frame 3 to suppress the amplitude of the movable frame 3 in the X-axis direction. If the partition plate 19 is provided outside the side perpendicular to the axial direction, the amplitude of the movable frame 3 in the Y-axis direction can also be suppressed.

  In addition, this partition plate 19 can absorb the impact by the amplitude of the movable frame 3 by elastic deformation of the partition plate 19 by using a resin film or rubber.

  Furthermore, when this partition plate 19 is formed of resin, rubber or the like, generation of static electricity can be suppressed by using a material containing inorganic particles such as silica or titanium oxide.

  Moreover, it does not need to be a plate-like body like the partition plate 19, and the horizontal amplitude of the movable frame 3 can be similarly suppressed even with a columnar body such as a cylinder or a prism.

The partition plate 19 and the concave portion 8 and the convex portion 9 or the convex portion 18 described in the first and second embodiments may be combined. For example, the end portion side of the movable frame 3 connected to the second beam 4 is supported by the partition plate 19 shown in the present embodiment, and the other end portion side is supported by the convex portion 18 shown in the second embodiment. Good. In the second embodiment, the second beam 4 cannot be connected to the outermost end of the movable frame 3 by forming the convex portion 18, but the second beam 4 can be connected by combining with the present embodiment. The structure connected to the outermost part of the movable frame 3 can be taken, and the movable frame 3 can be vibrated efficiently.
Description of other configurations and effects similar to those of the first embodiment is omitted.

(Embodiment 4)
As shown in FIG. 9, the optical reflecting element according to the present embodiment includes a package 21, and the package 21 is disposed on the terminal block 22, a bottom portion 23 provided on the terminal block 22, and the bottom portion 23. The support body 5, a frame body 24 that surrounds the outer periphery of the support body 5, and a lid portion 25 that covers the upper portion of the frame body 24 are provided. An upper protector 26 is disposed in the package 21 and inside the lid 25, and an upper surface facing the movable frame 3 with a predetermined gap is an upper protector surface 26A. A lower protector 27 is disposed on the bottom 23, and a lower surface facing the movable frame 3 with a predetermined interval is a lower protector surface 27A.

  The upper protector surface 26A and the lower protector surface 27A serve as amplitude suppression means in the Z-axis direction. That is, the upper protector surface 26A suppresses excessive vibrations of the movable frame 3 in FIG. 1 and the lower protector surface 27A suppresses excessive amplitudes of the movable frame 3 below. Note that a gap necessary for amplitude at a predetermined drive frequency is provided between the upper protector surface 26A and the lower protector surface 27A and the movable frame 3.

  The upper protector surface 26A of the present embodiment has the first beam 2, the movable frame 3, and the second beam 4 shown in FIG. 1 except for a transmission portion (hole 28) necessary for laser beam incidence / reflection at the mirror portion 1. It covers almost the entire upper part of the support 5.

  Further, the lower protector surface 27A covers the entire lower part of the mirror part 1, the movable frame 3, the first beam 2, and the second beam 4 of FIG.

  Examples of the material of the upper protector 26 and the lower protector 27 include elastic bodies such as resin and rubber, and nonwoven fabrics. If these materials are kneaded with carbon particles or carbon fibers, generation of static electricity can be suppressed.

  The effect of this embodiment will be described below.

  In the present embodiment, when an excessive impact or vibration is applied to the movable frame 3 that is a mass body in the thickness direction, that is, the Z-axis direction perpendicular to the XY plane, the movable frame 3 is positioned on the upper protector surface. 26A or the lower protector surface 27A is contacted, and the upper protector surface 26A and the lower protector surface 27A serve as stoppers, so that the amplitude can be suppressed.

  That is, when the movable frame 3 that is a mass body swings up and down, the second beam 4 deforms following the amplitude. Therefore, if the movable frame 3 is too large, the deformation of the second beam 4 exceeds the allowable range and may be damaged.

  On the other hand, in the present embodiment, the upper protector surface is measured so that the limit amplitude amount that the second beam 4 breaks is measured in advance, and the amplitude of the movable frame 3 remains at an amplitude smaller than the limit amplitude. 26A and the lower protector surface 27A were brought into contact with each other. Thereby, damage to the second beam 4 can be suppressed, and a highly reliable optical reflecting element can be realized.

  Then, as a result of performing an impact acceleration test in which gravitational acceleration is applied in the Z-axis direction, the second beam 4 was damaged at 60 G when the amplitude suppressing means by the upper protector surface 26A and the lower protector surface 27A was not provided. In the present embodiment, damage to the second beam 4 can be suppressed up to 2100G.

  In the present embodiment, both the upper protector surface 26A and the lower protector surface 27A are used, but only one of them may be provided. For example, as a result of performing an impact acceleration test in a state where the upper protector surface 26A is not formed and the lower protector surface 27A made of a nonwoven fabric is disposed below the movable frame 3, damage to the second beam 4 can be suppressed up to 860G. .

  Further, the suppression means for suppressing the vibration in the Z-axis direction of the movable frame 3 as in the present embodiment may be used alone, but the X-axis direction and / or Y of the movable frame 3 described in the first embodiment. By combining with the suppression means for suppressing the vibration in the axial direction, it is possible to suppress the excessive amplitude of the movable frame 3 in the three dimensions.

(Embodiment 5)
The main difference between the present embodiment and the fourth embodiment is the shapes of the lower protector surface 27A and the upper protector surface 26A as shown in FIGS.

  In the present embodiment, the upper protector surface 26 </ b> A and the lower protector surface 27 </ b> A are configured as slopes that descend outward from a region facing the central axis of the second beam 4. That is, both the upper protector surface 26 </ b> A and the lower protector surface 27 </ b> A are shaped so that the region facing the central axis S <b> 2 of the second beam 4 is convex.

  Further, in both the upper protector surface 26A and the lower protector surface 27A of the present embodiment, the region facing the central axis S2 of the second beam 4 and the vicinity thereof are configured by a horizontal plane. That is, the top is a convex shape constituted by a horizontal plane.

  Further, the second beam 4 of the present embodiment has a meander shape in which a plurality of diaphragms 7 are connected so as to meander on the same plane as in the first embodiment. The second beam 4 is driven such that the respective diaphragms 7 are alternately bent and vibrated in opposite phases, and the displacement is accumulated according to the number of diaphragms with the central axis S2 as the center. By this driving, the movable frame 3 is repeatedly rotated and oscillated around the central axis S2.

  The effect of this embodiment will be described below.

  In the present embodiment, even when an excessive impact or vibration is applied in the Z-axis direction when the movable frame 3 and the second beam 4 are driven, the damage can be effectively suppressed.

  The reason is that the upper protector surface 26A and the lower protector surface 27A are inclined according to the inclination centered on the central axis S2 when the movable frame 3 and the second beam 4 are driven.

  Therefore, even if G is applied in the Z-axis direction with the movable frame 3 and the second beam 4 tilted, almost the entire movable frame 3 and the second beam 4 are in contact with the upper protector surface 26A and the lower protector surface 27A. The stress load at the time of contact is distributed. As a result, excessive amplitude can be efficiently suppressed.

  Furthermore, in the present embodiment, the region facing the central axis S2 of the lower protector surface 27A and the vicinity thereof are horizontal surfaces, so that the bending of the diaphragm 7 can be suppressed.

  That is, as the diaphragm 7 of the second beam 4 becomes longer, the central portion, that is, the vicinity of the central axis S2 is more easily bent. If the bending width becomes too large, an excessive load is applied to the folded portion of the diaphragm 7, and the second beam 4 is damaged.

  Therefore, in a region facing the central axis S2, a horizontal plane is formed on the lower protector surface 27A, and the horizontal plane and the bending portion of the diaphragm 7 are brought into contact with each other, so that the bending can be suppressed and the optical reflecting element is damaged. Can be suppressed.

  In addition, the upper protector surface 26A has a horizontal plane in the region facing the central axis S2 and the vicinity thereof. However, with such a configuration, the mirror unit 1 has a horizontal plane above it, and it is easy to form a hole 28 for transmitting light. .

  In the present embodiment, as a result of an impact acceleration test in which gravitational acceleration is applied in the Z-axis direction for each package, damage to the optical reflective element can be suppressed up to 3150G.

  Since the optical reflective element of the present invention is hard to be damaged and has excellent mechanical reliability, it is useful for a head-up display used for in-vehicle use. It is also useful for small image projection devices such as small displays and head mounted displays that require high reliability, laser printers, and electrophotographic devices.

Top view of the optical reflecting element according to Embodiment 1 of the present invention. (A) Perspective view of the first beam of the optical reflecting element, (b) Cross section of the first beam of the optical reflecting element (cross section AA in FIG. 2 (a)) Side view showing operation of first beam of optical reflecting element Top view of the optical reflective element (A)-(c) Top view which expanded the principal part of the same optical reflective element. Top view of another example of optical reflecting element according to Embodiment 1 of the present invention The top view of the optical reflective element in Embodiment 2 of this invention (A) Top view of the optical reflecting element in Embodiment 3 of the present invention, (b) Cross-sectional view of the optical reflecting element (cross section AA in FIG. 8 (a)) Sectional drawing of the optical reflective element in Embodiment 4 of this invention The perspective view of the lower protector of the optical reflective element in Embodiment 5 of this invention Perspective view of the upper protector of the optical reflection element

DESCRIPTION OF SYMBOLS 1 Mirror part 2 1st beam 3 Movable frame 4 2nd beam 5 Support body 6 Diaphragm 7 Diaphragm 8 Concave part 9 Convex part 10 Piezoelectric element 11 Substrate 12 Ground electrode 13 Piezoelectric body 14A, 14B Drive electrode 15 Insulating layer 16 Concave part 17 Convex part 18 Convex part 19 Partition plate 20 Package 21 Package 22 Terminal block 23 Bottom part 24 Frame body 25 Cover part 26 Upper protector 26A Upper protector surface 27 Lower protector 27A Lower protector surface 28 Hole

Claims (11)

A mirror part and a movable frame connected to the mirror part via the first beam and surrounding the outer circumference of the first beam and the mirror part;
The movable frame and a support body connected through the second beam,
The first beam has a central axis in the Y-axis direction, the second beam has a central axis in the X-axis direction,
Drive means for repeatedly rotating and vibrating the mirror portion around these central axes;
An optical reflecting element provided with suppression means for suppressing at least one amplitude in the X-axis direction or the Y-axis direction of the movable frame. The suppression means is
The optical reflective element according to claim 1, comprising a convex portion provided on at least one of the movable frame or the support. The suppression means is
The optical system according to claim 2, comprising: a concave portion provided on an outer periphery of the movable frame; and a convex portion provided on the support, projecting into the concave portion, and fitted into the concave portion with a predetermined interval. Reflective element. The suppression means is
A convex portion provided on the support and protruding inward;
The optical reflecting element according to claim 2, wherein an inner side surface of the convex portion and an outer side surface of the movable frame are opposed to each other with a predetermined interval. At least one of the movable frame or the support is
The optical reflective element according to claim 2, wherein the thickness in the direction of the Z-axis perpendicular to the X-axis and the Y-axis is thicker than that of the second beam. The suppression means is
The optical reflection element according to claim 1, wherein the optical reflection element is a columnar body or a plate-like body that is provided between the movable frame and the support and faces the outer surface of the movable frame at a predetermined interval. The suppression means is
A convex portion provided on at least one of the movable frame or the support;
The optical reflecting element according to claim 1, which is a columnar body or a plate-like body provided between the movable frame and the support. A mirror part, a movable frame connected to the mirror part via the first beam and surrounding the outer periphery of the first beam and the mirror part;
The movable frame and a support body connected through the second beam,
The first beam has a central axis in the Y-axis direction, the second beam has a central axis in the X-axis direction,
Drive means for repeatedly rotating and vibrating the mirror portion around these central axes;
An optical reflecting element comprising suppression means for suppressing the amplitude of the movable frame in the Z-axis direction perpendicular to the X-axis and the Y-axis. The suppression means is
While provided on at least one of the upper surface or the lower surface facing the movable frame,
The optical reflecting element according to claim 8, wherein the region facing the central axis of the second beam has a convex shape. The optical reflection element according to claim 9, wherein the suppression unit has a convex shape with a top formed by a horizontal plane. A mirror part and a movable frame connected to the mirror part via the first beam and surrounding the outer circumference of the first beam and the mirror part;
The movable frame and a support body connected through the second beam,
The first beam has a central axis in the Y-axis direction, the second beam has a central axis in the X-axis direction,
Drive means for repeatedly rotating and vibrating the mirror portion around these central axes;
Suppressing means for suppressing vibration of at least one of the movable frame in the X-axis direction or the Y-axis direction;
An optical reflecting element comprising suppression means for suppressing the amplitude of the movable frame in the Z-axis direction perpendicular to the X-axis and the Y-axis.

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