JP2012113146A - Oscillation element, optical scanner, actuator device, video projection device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact oscillation element that has excellent anti-vibration fatigue property in a beam portion thereof and high rigidity in an oscillation portion thereof.SOLUTION: An oscillation element includes base substances 3; beam portions 2 provided in beam shape from the base substances 3; and a mirror portion 4 provided on one side of each of the beam portions 2, the one side being opposite to the base substance 3 side; and at least a part of the oscillation portion (mirror portion) 4 and the beam portions 2 are integrally formed of metallic glass. The mirror portion 4 of the oscillation element is then irradiated with a YAG laser 10 in vacuum to perform local structural relaxation.

Description

  The present invention relates to a vibration element, an optical scanning device, an actuator device, a video projection device, and an image forming device.

  Conventionally, an optical scanning device such as an optical scanner is known as an example of a device including a vibration element. For example, in the optical scanning device described in Patent Document 1, a beam portion made of stainless steel is provided on the substrate, a plate wave is induced on the substrate by a piezoelectric body or the like, and the mirror portion supported by the beam portion is swung. ing.

JP 2006-293116 A

  As shown in Patent Document 1, an optical scanning device that scans reflected light by oscillating a mirror part, which is an oscillating part of a vibration element, by resonance vibration and reflecting a laser beam or the like on a mirror surface. Proposed. In order to reduce the size of such an optical scanning device, it is necessary to reduce the size of a vibrating element that performs optical scanning. Since the vibration element is composed of a mirror part as a swinging part, a beam part, a substrate as a base for holding the beam part, etc., miniaturization of each part is required for miniaturization of the vibration element. By the way, since the mirror part swings, it is necessary to suppress the dynamic deflection, and the beam part needs to vibrate and torsionally vibrate. Therefore, in the downsizing of the vibration element, the function of the mirror part and the beam part is required. Characteristics must be considered.

  In view of the above-described circumstances, the present invention provides a mechanism that is effective in downsizing a vibration element and the like while giving a high vibration fatigue characteristic to the beam part and high rigidity to the rocking part.

  The vibration element of the present invention includes a base, a beam portion provided in a beam shape from the base, and a swing portion provided on a side opposite to the base side of the beam portion, and the swing portion At least a part of the beam part and the beam part are integrally formed of metal glass.

  ADVANTAGE OF THE INVENTION According to this invention, the vibration element etc. which were reduced in size can be effectively implement | achieved, giving a high vibration fatigue characteristic to a beam part and high rigidity to a rocking | swiveling part.

1a is a perspective view showing the configuration of the vibration element, FIG. 1b is a cross-sectional view of the mirror part, FIG. 1c is a cross-sectional view of the beam part, and FIG. 1d is a maximum displacement angle when the mirror part is twisted. FIG. 2a is a perspective view of the vibration element of Example 1, FIG. 2b is a graph of the Young's modulus distribution corresponding to the cross section along the line BB ′ and the longitudinal direction of the vibration element, and FIG. 2c is along the line CC ′. Sectional drawing and FIG. 2d are sectional drawings in the DD 'line of FIG. 3a, 3b, and 3e to 3h are process diagrams in Example 1, FIG. 3c is a cross-sectional view taken along line EE ′ of FIG. 3b, and FIG. 3d is a relationship between an aspect ratio and a film thickness of the metal mask. The graph which showed. 4A is a perspective view illustrating the configuration of the vibration element according to Example 2, and FIG. 4B is a graph illustrating a Young's modulus distribution corresponding to a cross section taken along line B-B ′ and the longitudinal direction of the vibration element. Process drawing in Example 2. FIG. 6A is a perspective view illustrating the configuration of the vibration element of Example 3, and FIG. 6B is a graph of a Young's modulus distribution corresponding to the cross section along the line B-B ′ and the longitudinal direction of the vibration element. Process drawing in Example 3. FIG. FIG. 8A is a perspective view showing the configuration of the vibration element of Example 4, and FIG. 8B is a graph of the Young's modulus distribution corresponding to the cross section along line B-B ′ and the longitudinal direction of the vibration element. Process drawing in Example 4. FIG. 10a and 10b are schematic top and bottom views of the microdevice resonator of the fifth embodiment, and FIG. 10c is a schematic diagram of laser scanning of the fifth embodiment. The metal mask of Example 5. 12a and 12b are schematic cross-sectional views showing a single metal mask of Example 5, and FIGS. 12c and 12d are schematic cross-sectional views showing a double metal mask of Example 5. FIG. 10 is a graph showing the relationship between silicon stress and temperature in Example 5. 14A is a gap diagram of the vibrator of Example 5, and FIG. 14B is a schematic cross-sectional view illustrating an annealing method. The graph which shows the result of having performed heat processing by changing the load of Example 5. FIG. 16a to 16f are views showing a method for manufacturing the microdevice resonator of the fifth embodiment. 6 is a photograph of the microdevice vibrator of Example 5. A photograph showing the laser scanning method. The figure which shows an actuator apparatus. 1 is a diagram illustrating an image forming apparatus. The figure which shows an image projector.

[Embodiments of vibrating element and optical scanning device]
FIG. 1 a shows a vibration element 30 that swings the mirror part 4 formed integrally with the beam part 2 by moving the beam part 2 by using the alternating magnetic field by the electromagnetic coil 14 and the resonance vibration by the magnet 12. The mirror unit 4, which is an oscillating unit, oscillates about the center of the beam unit 2 as a rotation axis, and scans the reflected light by the movement of the mirror unit 4. One end of the beam portion 2 is fixed to the base 3. 1b is a cross section of the mirror section 4, FIG. 1c is a cross section of the beam section 2, and FIG. 1d is a cross section of the mirror section 4 showing the maximum displacement angle when the mirror section 4 swings. Note that at least a part of the mirror part 4, the beam part 2, and the base 3 are integrally formed of the same metallic glass in each example of the present embodiment, as will be described later. Terms and symbols indicating each physical quantity and vibration characteristic in the vibration element 30 are set as follows.
E: Young's modulus of the material constituting the beam part 2 and the mirror part 4 υ: Poisson's ratio of the material constituting the beam part 2 and the mirror part 4 G: Transverse elastic modulus of the material constituting the beam part 2 and the mirror part 4 ρ : Density of material constituting the beam part 2 and the mirror part 4 τ _FL : Fatigue limit of the material constituting the beam part 2 and the mirror part 4 p: Length of the mirror part 4 w: Width of the mirror part 4 d: Mirror part Thickness of 4 L: Length of beam 2 s: Width of beam 2 t: Thickness of beam 2 f: Resonant frequency of torsional vibration θ: Maximum twist angle of vibration element 30 K: Spring constant of beam 2 τ : Maximum stress generated in torsion beam during vibration I: Moment of inertia of vibration element around central axis of beam part 2 δ: Dynamic deflection of mirror part 4

Based on the model of the vibration element 30 shown in FIG. 1, the vibration element 30 is maintained while maintaining vibration characteristics (resonance frequency f of torsional vibration, maximum twist angle θ of the vibration element 30, dynamic deflection δ of the mirror unit 4, etc.). We will describe what kind of material characteristics are necessary for miniaturization. When the mirror portion 4 causes torsional vibration with the center of the beam portion 2 as the rotation axis, stress is generated in the beam portion 2 and is maximized by the maximum displacement angle θ. Further, the maximum stress τ generated in the beam portion 2 can be estimated by the following formula 1.
τ = Gtθ / L (1)
The maximum stress τ generated in the beam portion 2 must be set smaller than the fatigue limit τ _{FL of the} material constituting the beam portion 2. Otherwise, the beam portion 2 will break or greatly reduce its strength. When the length L of the beam portion 2 is reduced in order to reduce the size of the vibration element 30, the material constituting the beam portion 2 has a higher fatigue limit τ _FL and a lower lateral elastic modulus G. A method of selecting is required. The transverse elastic modulus G is obtained by the following formula 2 using the Poisson's ratio υ and Young's modulus E.
G = E / 2 (1 + υ) (2)
Since the Poisson's ratio υ is constant depending on the material, the transverse elastic modulus G and Young's modulus E are in a proportional relationship. That is, if the Young's modulus E of the material is determined, the transverse elastic modulus G can be calculated in the same manner. As described above, in order to reduce the size of the vibration element 30, it is required that the material constituting the beam portion 2 has a low Young's modulus and a high fatigue limit (high fatigue characteristics). In the mirror part 4 of the vibration element 30, there is a problem that a deflection occurs due to a swing caused by optical scanning (dynamic deflection δ), and the reflected light is distorted. Then, Equation 3 for estimating the dynamic deflection δ is expressed as follows.

  This dynamic deflection must be below a certain standard (specification) according to the intended scanning mode. That is, the material for forming the mirror portion 4 is suitable for a material having a relatively high elastic modulus and a small specific gravity. To summarize the above two points, in order to reduce the size of the optical scanning device, the beam portion 2 preferably has a low Young's modulus and a high fatigue property, but the mirror portion 4 has a high Young's modulus to suppress dynamic deflection. Since the rate is required, the required Young's modulus varies depending on the component.

  Here, in the present embodiment, the mirror part 4 and the beam part 2 serving as the swing part are functionally separated as parts having different mechanical characteristics, and at least a part of the mirror part 4 and the beam part 2 are made of a metal material. Are integrally formed. Here, the mechanical characteristics refer to properties with respect to externally applied forces (external forces) such as tension, bending, compression, shearing, hardness, impact, fatigue, and the like. The mechanical characteristics in 4 are high elasticity (or high Young's modulus), and the mechanical characteristics in the beam portion 2 are low elasticity (or low Young's modulus) and high fatigue characteristics. The function separation of the mirror part 4 and the beam part 2 as parts having different mechanical characteristics means that, for example, in this embodiment, the mirror part 4 functions as a swing part, and the beam part 2 is a drive part. It means to function as.

  As a material for forming the mirror part 4 and the beam part 2 as in the present embodiment, a material having a good fatigue limit and a low Young's modulus is preferable, and specifically, metallic glass can be mentioned. Metallic glass is an amorphous alloy that exhibits a glass transition, is less likely to undergo plastic deformation due to crystals, and has a wide elastic region. Metallic glass has characteristics of high strength, high fatigue characteristics, high corrosion resistance, and low Young's modulus as compared with general alloys. In addition, since the metallic glass has excellent thermal stability and has a supercooling region, it is not affected by the thermal influence of the manufacturing process, and three-dimensional processing using the supercooling region is possible. Here, a space in which atoms or molecules can freely move around by movements inside the material (rotation of the molecular chain, twisting, etc.) and external movements (vibration, rotation of the molecule itself) is called a free volume. . The free volume is a value indicating the mobility of atoms and molecules inside the material, and the larger the value, the more flexible the movement with respect to external strain. In the vibration element 30, when the beam portion 2 reaches the fatigue limit due to long-time vibration, the possibility that a fatigue crack is generated due to tearing of atoms and molecules of the material structure is increased. At this time, if the free volume is high, atoms and molecules in the material structure can move tenaciously, so that deterioration such as fatigue cracks can be suppressed.

  Metallic glass is an amorphous alloy and does not have a crystal structure. The amorphous structure has a structure with more gaps than the crystal structure, and this gap can be defined as a free volume. Metallic glass is a metastable material with a supercooled region, so structural relaxation occurs when heated above a certain temperature, for example, close to the glass transition temperature as in general glass materials, or close to the crystallization temperature. Will occur. Structural relaxation refers to a process in which randomly arranged atoms (amorphous structure) undergo rearrangement due to heat from the outside and change to a stable state (crystal). When the heating is continued beyond the glass transition temperature or the crystallization temperature, the atoms are completely changed to a stable state and a crystal phase is generated, and the amorphous structure peculiar to the metallic glass is lost and the free volume is reduced. This is a phenomenon called crystallization. In this way, the metal glass undergoes rearrangement every time it undergoes structural relaxation and crystallization, and the free volume, which is a gap between the atoms, is reduced.

  Due to structural rearrangement or rearrangement of atoms by crystallization, gaps in the material are reduced, resulting in a dense structure. Thereby, since the shape deformation (strain) with respect to the stress is less than that of the amorphous structure, the Young's modulus increases as a whole material. In addition, since the rearrangement of atoms is more advanced in the state where crystallization is completed than in the state after structure relaxation, the Young's modulus after crystallization becomes higher when compared with the same material. . Further, since the crystal structure has a unique mechanical property against strain as a structure, the Young's modulus can be further increased.

  As described above, for example, a decrease in free volume in a metallic glass is accompanied by an increase in Young's modulus. Therefore, if partial (selective) structural relaxation is performed in a certain structure, the function of the portion is improved (specifically, Can increase Young's modulus). If such partial structural relaxation in the structure is employed in the vibration element 30 in the optical scanning device, functional separation is realized between the beam portion 2 and the mirror portion 4, that is, the beam portion 2 has a low Young's modulus and high fatigue. Since the characteristics and the mirror part 4 can achieve a high Young's modulus, the degree of freedom in the structural design of the vibration element 30 is improved, the vibration element 30 can be downsized, and the optical scanning device can be downsized.

In the embodiment, as described above, the mirror portion 4 and the beam portion 2 that are the swinging portions are integrally formed of metal glass, but the mirror portion 4 is basically divided into two regions. It is done. Specifically, the mirror unit 4 is positioned within a predetermined distance from the connection portion between the beam unit 2 and the base that holds the beam unit 2 and the direction in which the beam unit 2 and the mirror unit 4 are arranged. The first region (region that easily affects the mechanical characteristics or function of the beam portion 2) and the second region located outside a predetermined distance (region that does not directly affect the mechanical properties or function of the beam portion 2) ). In addition, it is preferable that at least the second region of the mirror unit 4 is the target region for the structure relaxation. Thereby, the mirror part 4 and the beam part 2 can be effectively separated from each other as parts having different mechanical characteristics, and the vibration element 30 having desired characteristics can be realized.
Next, embodiments of the present invention will be described in detail with reference to the drawings.

[Example 1]
In the first embodiment, all of the vibration elements including the mirror part, the beam part, and the base body as the oscillating part are integrally formed of metal glass, and the center part of the mirror part is heat treated to increase the rigidity of the mirror part. By ensuring that no heat treatment is applied, high fatigue resistance is ensured for the beam.

  FIG. 2A is a perspective view illustrating the vibration element 30 which is a part of the optical scanning device according to the first embodiment. In FIG. 2a, the vibration elements 30 are all made of metallic glass Cu—Zr—Ti. The beam portion 2 is coupled to the base 3 and supported at one end thereof. The mirror unit 4 is coupled to and supported by the end of the beam unit 2 opposite to the base 3 and swings about the beam unit 2 as a torsional rotation shaft, thereby allowing light to be reflected and scanned. . FIG. 2B shows a Young's modulus distribution corresponding to the cross section along line B-B ′ of FIG. 2A and the longitudinal direction of the vibration element 30. Since the boundary portion between the beam portion 2 and the mirror portion 4 is strongly stressed when it swings, it has a low Young's modulus, a large free volume, and a high fatigue strength. On the contrary, the mirror part 4 has a high Young's modulus in order to suppress dynamic deflection. However, since a large stress is also generated at the boundary portion between the mirror portion 4 and the beam portion 2, the Young's modulus having a gradient on the mirror portion 4 side is maintained at the boundary portion while maintaining the same Young's modulus as the beam portion 2. Distribution. 2c is a cross-sectional view taken along line C-C 'of FIG. 2a. 2d is a cross-sectional view taken along line D-D 'of FIG. 2a. The film thickness of the rear end portion of the mirror part 4 is smaller than that of the center part of the rear surface of the mirror part, and the thickness of the mirror part 4 is thicker than that of the beam part 2.

  The reason why the cross-sectional shape of the mirror part 4 is set to such a shape will be described. In order to suppress the dynamic deflection of the mirror part 4, it is effective to increase the thickness of the mirror part 4 in order to improve the rigidity. However, since the moment of inertia of the mirror portion 4 increases due to the increase in thickness, the force necessary for swinging increases. When reducing the size of the optical scanning device, it is desirable to reduce the size of the vibration element 30 and the size of the device that generates the force required for vibration. Since downsizing of the device that generates this force causes a reduction in force, it is desirable to suppress the moment of inertia in the mirror section 4 of the vibration element 30 in order to downsize the optical scanning device. In order to reduce the moment of inertia while suppressing the dynamic deflection, the mirror portion 4 has a shape in which the thickness is reduced at the end of the mirror surface back side. As a result, the mass of the mirror portion 4 can be reduced while suppressing the amount of dynamic deflection, so that the moment of inertia can be suppressed.

  Next, a method for manufacturing the resonator element 30 according to the first embodiment will be described with reference to FIGS. As shown in FIG. 5a, Cu5 is formed on the Si single crystal substrate 1 by sputtering to a thickness of 1 to 2 [mu] m. Next, as shown in FIG. 3 b, a metal mask 6 having the shape of the vibration element 30 shown in FIG. 1 as an opening is disposed on Cu 5 on the Si single crystal substrate 1. Here, the metal mask 6 is used for explanation, but a mask pattern such as a photoresist may be used instead of the metal mask 6. FIG. 3c is a diagram showing a cross section in the E-E 'plane of FIG. 3b. Next, as shown in FIG. 3 c, metal glass Cu—Zr—Ti particles are incident from the opening of the metal mask 6 by sputtering film formation, and a desired film thickness is deposited on the substrate 1. FIG. 3d is a graph showing the relationship between the opening aspect ratio (metal mask thickness / opening width) of the metal mask 6 in FIG. 3c and the thickness (film thickness) of the deposited metal glass Cu-Zr-Ti. In this case, the film thickness when the metal mask 6 is used is expressed as a ratio to the film thickness when the aspect ratio is 0 (when the metal mask is not used). As shown in the figure, it can be seen that the deposited film thickness decreases as the aspect ratio increases.

  In order to reduce the dynamic deflection of the mirror section 4, when the mirror section 4 is thickened, the metal mask 6 is designed in advance using the relationship shown above. For example, if the thickness of the mirror part 4 needs to be twice that of the beam part 2, the opening aspect ratio of the mirror part 4 should be 0.5 or less and the opening aspect ratio of the beam part 2 should be 2.0. It ’s fine. And since the particle | grains of the metal glass Cu-Zr-Ti by which the sputter film formation was carried out are hard to inject into the edge part of the cross section of the mirror part 4, thickness decreases as it goes to an edge part. Thus, by increasing the thickness of the center of the mirror part 4 and reducing the thickness of the end part, it is possible to suppress the moment of inertia while suppressing the dynamic deflection.

  Next, when the metal mask 6 on the substrate 1 is removed and Cu5 is removed by etching with nitric acid, the metal glass Cu—Zr—Ti which is the main body of the vibration element 30 is removed from the Si single crystal substrate 1 as shown in FIG. Can be separated. Next, as shown in FIG. 3f, the structure relaxation is performed locally by irradiating the mirror part 4 of the vibration element 30 with the YAG laser 10 in a vacuum. The structural relaxation can be adjusted by adjusting the irradiation time of the YAG laser 10 and the laser diameter, thereby providing a temperature increase gradient depending on the location. Sufficient structural relaxation is performed at the center of the mirror part 4 and temperature rise is suppressed as the beam part 2 is approached so that structural relaxation is not performed at the beam part 2. Further, in order to prevent structural relaxation due to heat conduction from the mirror part 4, a cooling plate 9 for releasing heat is brought into close contact with parts other than the mirror part 4. The desired structural relaxation is achieved by adjusting the conditions of the YAG laser 10 and the cooling plate 9 described above.

  As a method for relaxing the structure, any method other than the above-described YAG laser 10 can be used as long as it can perform local heating. For example, a method in which a heated metal piece or the like is pressed against a target region, a method in which the target region is covered with an electromagnetic coil, and heating is performed by induction heating can be given. In addition, since the structure is relaxed to increase the Young's modulus, it is also effective to generate a crystal phase by heating to the crystallization temperature. In this case, however, it is desirable to consider other physical property changes due to crystallization.

  Next, as shown in FIG. 3g, an Au film 19 is formed as a reflective film on the flat surface of the mirror portion 4 of the vibration element 30, and the magnet 12 used for torsional vibration is bonded to the back side with an adhesive. Next, as shown in FIG. 3h, the electromagnetic coil 14 required for electromagnetic driving is placed on the back side of the mirror portion 4 at a position where the vibration element 30 can swing by applying an acting force by a magnetic field to the magnet 12. Deploy. Further, the laser scanning device is arranged so as to perform desired optical scanning, and the optical scanning device is completed. In addition to the driving method using electromagnetic force, various driving methods can be supported by adding a necessary structure.

[Example 2]
The second embodiment is the same as the first embodiment in that all the vibration elements including the mirror portion, the beam portion, and the base are integrally formed of metal glass. However, in the second embodiment, an intermediate portion is provided between the mirror portion and the beam portion. Is provided.

  FIG. 4A is a perspective view illustrating a vibrating element 30 that is a part of the optical scanning device according to the second embodiment. In FIG. 4a, the vibration elements 30 are all made of metallic glass Cu—Zr—Ti. The mirror part 4 is supported by the beam part 2 via an intermediate part 17 having a narrower width than the mirror part 4, and the beam part 2 is supported by the base bodies 3 at both ends thereof. Then, it is possible to scan light by swinging with the beam portion 2 as a twisting rotation axis. As described in the first embodiment, it is effective to increase the Young's modulus of the mirror portion 4 by structural relaxation to reduce the size of the vibrator 30. However, on the other hand, since a low Young's modulus is desired in the beam portion 2, it is not desirable to relax the structure. That is, when the structure is relaxed, it is desirable to accurately divide the region to be heat-treated. However, structural relaxation by heating or the like always causes a temperature gradient in the heating region. In order to solve this, an intermediate portion 17 that is a heat buffering region is arranged between the beam portions 2 so that each of the mirror portion 4 and the beam portion 2 has a desired Young's modulus. FIG. 4B is a cross-sectional view taken along line B-B ′ of FIG. 4A and a Young's modulus corresponding to the region is shown in a graph.

  Next, a method for manufacturing the resonator element 30 according to the second embodiment will be described. First, as shown in FIG. 5 a, a vibrator 30 having a mirror part 4, a beam part 2, an intermediate part 17, and a base 3 is manufactured using a metal glass Cu—Zr—Ti as a raw material. Any method may be used as long as the physical properties of the metal glass and the intended dimensions can be processed. For example, a ribbon-shaped alloy plate is prepared by using a melting method and a liquid quenching method, and a shape is formed by pressing, or as described in Example 1, a sputter film formation widely performed in a semiconductor process or the like. And a method using a lift-off process.

  Next, as shown in FIG. 5b, the structure is locally relaxed by irradiating the mirror part 4 of the vibration element 30 with the YAG laser 10 in a vacuum. The structural relaxation can be adjusted by adjusting the irradiation time of the YAG laser 10 and the laser diameter, thereby providing a temperature increase gradient depending on the location. Further, in order to prevent structural relaxation due to heat conduction from the mirror part 4, a cooling plate 9 for releasing heat is brought into close contact with parts other than the mirror part 4. The desired structural relaxation is achieved by adjusting the conditions of the YAG laser 10 and the cooling plate 9 described above. If a driving device necessary for swinging is added to the vibrating element 30, an optical scanning device is completed.

[Example 3]
The third embodiment is the same as the first and second embodiments in that all the vibration elements including the mirror portion, the beam portion, and the base are integrally formed of metal glass. However, in the third embodiment, the entire mirror portion is subjected to heat treatment. ing.

  FIG. 6A is a perspective view illustrating a vibration element 30 that is a part of the optical scanning device according to the third embodiment. In FIG. 6a, the vibration elements 30 are all made of metallic glass Cu—Zr—Ti. The mirror part 4 is supported by the beam part 2, and the beam part 2 is supported by the base | substrate 3 of the both ends. Then, it is possible to scan light by swinging with the beam portion 2 as a twisting rotation axis. As described in the first embodiment, it is effective to increase the Young's modulus of the mirror portion 4 by structural relaxation for the size reduction of the vibration element 30. However, on the other hand, since a low Young's modulus is desired in the beam portion 2, it is not desirable to relax the structure. That is, when the structure is relaxed, it is desirable to accurately divide the region to be heat-treated. However, in practice, a structural gradient by heating or the like always causes a temperature gradient in the heating region, so that a part of the beam portion 2 that is in contact with the mirror portion 4 undergoes structural relaxation and the Young's modulus increases. . FIG. 6B is a cross-sectional view taken along line B-B ′ of FIG. 6A and a Young's modulus corresponding to the region is shown in a graph.

  Next, a method for manufacturing the resonator element 30 according to the third embodiment will be described. First, as shown in FIG. 7 a, a vibration element 30 having a mirror part 4, a beam part 2, and a base 3 using a metal glass Cu—Zr—Ti as a raw material is manufactured. Any method may be used as long as the physical properties of the metal glass and the intended dimensions can be processed. For example, a ribbon-shaped alloy plate is prepared by using a melting method and a liquid quenching method, and a shape is formed by pressing, or as described in Example 1, a sputter film formation widely performed in a semiconductor process or the like. And a method using a lift-off process.

  Next, as shown in FIG. 7B, the structure is locally relaxed by irradiating the mirror part 4 of the vibration element 30 with the YAG laser 10 in a vacuum. The structural relaxation can be adjusted by adjusting the irradiation time of the YAG laser 10 and the laser diameter, thereby providing a temperature increase gradient depending on the location. Further, in order to prevent structural relaxation due to heat conduction from the mirror portion, a cooling plate 9 for releasing heat is brought into close contact with portions other than the mirror portion 4. The desired structural relaxation is achieved by adjusting the conditions of the YAG laser 10 and the cooling plate 9 described above. If a driving device necessary for swinging is added to the vibrating element 30, an optical scanning device is completed.

[Example 4]
In Example 4, the mirror part has a laminated structure of a pedestal and an optical member, the pedestal of the mirror part, the beam part, and the base are integrally formed of metal glass, and the mirror part is formed by heat treatment and a laminated structure of the central part of the mirror part. Increased rigidity.

FIG. 8A is a perspective view illustrating a vibration element 30 that is a part of the optical scanning device according to the fourth embodiment. In FIG. 8a, the beam portion 2 of the vibration element 30, the pedestal 18 of the mirror portion 4, and the base 3 are integrally formed of metal glass. The optical member 11 bonded to one surface of the pedestal 18 is formed of Si single crystal, and the reflection film 19 constituting the mirror surface is formed of Au film. The material for forming the reflective film 19 is not limited to Au, and may be appropriately selected in consideration of the application and the spectral characteristics and durability of the reflective film. For example, aluminum (Al), silver (Ag) A metal material such as copper (Cu) can be used as appropriate. Here, although the reflective film 19 is described using a single-layer Au film, a dielectric film (SiO ₂ , SiO, TiO) composed of a single layer or a plurality of layers is used for the purpose of protection and improvement of reflection characteristics. _{A structure in which 2X} , MgF ₂ , ZrO ₂ , Al ₂ O ₃ , Ta ₂ O ₅ , etc.) are stacked may be applied. The mirror portion 4 composed of the reflective film 19, the optical member 11, and the pedestal 18 is supported by the beam portion 2 by the pedestal 18, and the beam portion 2 is supported by the base 3 at both ends thereof. Then, it is possible to scan light by swinging with the beam portion 2 as a twisting rotation axis.

  As described above, the dynamic deflection in the mirror portion 4 of the vibration element 30 must be below a certain reference according to the form of optical scanning. As described in the first embodiment, in order to reduce the dynamic deflection, it is desirable that the mirror part 4 has high rigidity. However, if the thickness of the mirror part 4 is increased to increase the rigidity, the moment of inertia increases. End up. In order to solve this, there is a method in which a light and high rigidity material such as Si single crystal is added to the mirror portion 4. At this time, if the rigidity or Young's modulus of the pedestal 18 of the mirror part made of metal glass is increased by structural relaxation, the thickness of the Si single crystal added to improve the rigidity of the mirror part 4 can be reduced. Thus, the weight of the entire mirror unit 4 can be reduced. If the weight of the entire mirror unit 4 can be reduced, the moment of inertia of the mirror unit 4 can be reduced, and the force for swinging the mirror unit 4 can be reduced. As described in the first embodiment, if the force required for swinging can be reduced, the device that generates the force can be reduced in size, so that the entire optical scanning device can be reduced in size. FIG. 8B is a cross-sectional view taken along line B-B ′ of FIG. 8A and the graph shows the rigidity corresponding to the region.

  Next, a method for manufacturing the resonator element 30 according to the fourth embodiment will be described. First, as shown in FIG. 9 a, a vibrating element 30 having a mirror base 18, a beam portion 2, and a base 3 is manufactured using metal glass Cu—Zr—Ti as a raw material. Any method may be used as long as the physical properties of the metal glass and the intended dimensions can be processed. For example, a ribbon-shaped alloy plate is prepared by using a melting method and a liquid quenching method, and a shape is formed by pressing, or as described in Example 1, a sputter film formation widely performed in a semiconductor process or the like. And a method using a lift-off process.

  Next, as shown in FIG. 9 b, the structure is locally relaxed by irradiating the base 18 of the mirror part of the vibration element 30 with the YAG laser 10 in a vacuum. The structural relaxation can be adjusted by adjusting the irradiation time of the YAG laser 10 and the laser diameter, thereby providing a temperature increase gradient depending on the location. Further, in order to prevent structural relaxation due to heat conduction from the mirror base 18, a cooling plate 9 for releasing heat is brought into close contact with a portion other than the base 18. The desired structural relaxation is achieved by adjusting the conditions of the YAG laser 10 and the cooling plate 9 described above.

  Next, as shown in FIG. 9c, the Si single crystal is processed to form the optical member 11. Any manufacturing method may be used as long as processing can be performed to the intended dimensions. For example, there are a method of processing a Si single crystal substrate by dicing and a Si etching method using potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH) or the like. Next, as shown in FIG. 9 d, a reflective film 19 is attached to the optical member 11. Examples of the method include sputter film formation and vapor deposition. The optical member 11 provided with the reflection film 19 is bonded to the pedestal portion 18 of the mirror portion described above with an adhesive. Thereby, the vibration element 30 of FIG. 8 a is completed. If a driving device necessary for swinging is added to the vibrating element 30, an optical scanning device is completed.

[Example 5]
In the embodiment, as in the fourth embodiment, the mirror portion has a laminated structure of a pedestal and an optical member, the pedestal of the mirror portion, the beam portion, and the base are integrally formed of metal glass, and the mirror portion has a laminated structure. Increases rigidity.

10A and 10B are conceptual diagrams of the vibration element 30 of the micromirror device. The mirror portion 4 formed of a silicon single crystal is supported by the base 3 and the torsion bar (beam portion) 2 at both ends of a base made of Cu-based thin film metal glass (Cu ₆₄ Zr ₂₈ Ti ₈ ). . Further, a magnet 12 is bonded to the back side of the mirror unit 4 for driving, and the mirror unit 4 is oscillated by a magnetic field generated by the electromagnetic coil 14. FIG. 10c is a cross-sectional view of the mirror portion 4 of the vibration element 30 shown in FIGS. 10a and 10b, and represents optical scanning of the micromirror device. Due to the alternating magnetic field generated from the electromagnetic coil 14, the magnet 12 resonates around the center of the torsion bar 2 to generate torsional vibration. Since the mirror unit 4 also swings according to the torsional vibration, the incident light is scanned accordingly. The angle at which the mirror surface swings at this time is hereinafter referred to as a swing angle θ.

Here, as a material used for the pedestal, the base 3, and the torsion bar (beam portion) 2, for example, a Cu-Zr-Ti system which is a Cu-based thin film metal glass is adopted. Thereby, a low longitudinal elastic modulus, high strength, and high fatigue characteristics can be obtained. Then, an alloy target was manufactured by arc melting of each constituent element of Cu, Zr, and Ti, and Cu-Zr-Ti in a thin film state was manufactured by sputtering film formation. The longitudinal elastic modulus E and the tensile strength σ were measured by a tensile test at room temperature using a thermomechanical testing machine (TMA (Rigaku, TA-60)), and E = 62.3 Gpa and σ = 0.9 GPa were obtained, respectively. . Then, the composition Cu ₆₄ Zr ₂₈ Ti ₈ of the metal glass was confirmed by energy dispersive X-ray analysis EDX (Shimadzu Corporation, μEDX-1200). Moreover, it was confirmed by differential scanning calorimetry DSC (ULVAC, DSC9400) that the glass transition temperature of the metallic glass was Tg = 734K and the crystallization temperature was Tx = 768K. Further, the density ρ was 7.2 g / cm ³ .

When the cross section of the torsion bar 2 is rectangular, the resonance frequency f of the mirror part supported by the support part and the spring constant K of the torsion bar 2 are expressed by expressions 4 and 5.

  When the lateral elastic modulus G, which is a material characteristic, and the moment of inertia I of the mirror portion 4 are constant, the resonance frequency is determined by the length L, width s, and thickness t of the torsion bar 2. In particular, since the thickness t is a third power and relates to the increase and decrease of the spring constant, it is effective to increase the thickness of the torsion bar 2 in order to obtain a higher resonance frequency.

  In the production of the metallic glass film used for the torsion bar 2, sputtering film formation can be employed. However, in the sputter film formation method using a photoresist, the film thickness of the obtained metal glass is several μm or less. This is because crystallization and embrittlement of the metal glass occur due to heat generated during film formation. However, in the micromirror device, depending on the application, a high resonance frequency of about 1 kHz to 30 kHz is set. Therefore, as described above, it may be required to increase the film thickness to widen design options. For this reason, we focused on thin metal glass with a supercooled region and high thermal stability, and realized a process that can produce ultra-thick film structures using thin metal glass.

  A lift-off process using a mask is used to manufacture a structure using sputter deposition. When a photoresist is used as a mask, when the film thickness to be patterned by lift-off increases, the film forming material may be oxidized due to degassing from the photoresist due to a temperature rise during film formation. Therefore, it is preferable to use a material that does not generate gas for the mask. Therefore, in Example 5, the lift-off process as shown in FIG. 12 was selected using the stainless steel metal mask shown in FIG.

  12a shows a cross-sectional view of a state in which one metal mask is fixed on a silicon single crystal substrate, and FIG. 12b shows a cross-sectional view during film formation. In this method, the metal mask is deformed by the film stress and peels off from the substrate in the vicinity of the opening. And since sputtered particles accumulate from the peeled gap, the shape of the side surface of the cross section of the vibration element is greatly different from the pattern of the metal mask. In order to solve this problem, the present embodiment employs a method in which the metal mask shown in FIGS. 12c and 12d is doubled and the lower metal mask and the substrate are bonded by a photoresist.

  FIG. 12c shows a double structure of the metal mask. A positive resist of 1 to 2 μm is applied on a silicon single crystal substrate, and a metal mask shown in FIG. 11 having an oscillator structure as an opening pattern is fixed thereon. By performing exposure and development in this state, the resist in the opening pattern portion is removed, and the metal mask and the substrate are bonded by post-baking. Then, the second metal mask is stacked and fixed, and fixed to the film forming apparatus with screws. FIG. 12d is a view showing a cross section of the vibration element 30 during the sputtering film formation. During the film formation, stress is generated in the upper metal mask and deformation occurs. However, since the lower metal mask is in close contact with the substrate, the side shape of the cross section of the vibration element 30 is maintained. Further, since the resist does not directly touch the sputtered particles, there is no concern about gas generation. Using this technique, a structure with a maximum film thickness of 100 μm was successfully produced without breaking the cross-sectional shape. As the aspect ratio of the opening pattern (T / L in FIG. 12c) increases, the probability that sputtered particles will reach the inside of the opening decreases. Using this phenomenon, the thickness of the metal glass in the torsion bar (beam portion) 2 could be reduced to 59.5 μm even though the thickness of the metal glass in the mirror portion 4 having a low aspect ratio was 105 μm. .

  Here, the low temperature annealing will be described. During sputter deposition, internal stress is generated in the film. As a result, the torsion bar 2 has a non-uniform internal stress distribution in the film thickness direction after film formation, and thus deforms. For the stress relaxation of the thin film metallic glass, structural relaxation at a temperature below the glass transition temperature and in the vicinity of the glass transition temperature is suitable. When heat treatment is performed in a vacuum heating furnace at 673 K (Tg-65 K) for 5 minutes, the thin film metallic glass Cu The phenomenon that -Zr-Ti and a silicon single crystal part peeled off occurred.

For this reason, the thermal stress of the silicon single crystal and the thin film metal glass Cu—Zr—Ti was estimated. First, it is assumed that the two materials are in close contact with each other at room temperature (T ₀ ) with zero stress. Then, when the temperature rises by using thermomechanical tester (TMA) in the measured Cu-Zr-Ti coefficient of linear expansion alpha _a silicon single crystal of the linear expansion coefficient alpha _b and longitudinal elastic modulus E, Poisson's ratio upsilon (T _The stress σ _{ab applied} to the silicon single crystal substrate in ₁ ) was calculated using Equation 6.

  The result is shown in FIG. Although the tensile strength of silicon single crystals varies depending on the literature, it is about 700 to 1300 MPa, and it is expected to break in the temperature range of 200 to 300 ° C. corresponding to FIG. In this embodiment, in order to determine the heat treatment temperature, a substrate in which Cu—Zr—Ti is formed by sputtering on a silicon single crystal substrate is prepared and heated at 200 ° C., 250 ° C., and 300 ° C. for 6 hours, respectively. The experiment was conducted under the three conditions maintained. As a result, since only the sample at 200 ° C. for 6 hours did not peel, 200 ° C. was set as the stress relaxation temperature in this experiment. Therefore, the vibration element was subjected to heat treatment at 200 ° C. for 1 hour in a vacuum heating furnace. However, although some stress relaxation was confirmed, the stress was not completely released. Even when the treatment time was extended to 6 hours or 12 hours, no progress of stress relaxation was observed. As a cause of this, it is considered that when heat treatment is performed without fixing the vibration element 30, stress relaxation proceeds while the internal stresses of the front and back are not balanced and warped due to the influence of silicon remaining on the pole surface. Therefore, an attempt was made to relieve stress by heating and holding the torsion bar portion 2 of the vibration element 30 while fixing it. The state at the time of the heat treatment is shown in FIG. The torsion bar is fixed with a sample piece of alumina and a silicon single crystal substrate, and receives a load via an upper tungsten chip. The warpage of the entire vibration element is measured in the form shown in FIG. 14a, and the result of heat treatment with the load changed is shown in FIG. It was confirmed that if the treatment was performed at 200 ° C. for 12 hours while applying the load of the tungsten chip 24g, the warpage would be near zero.

Based on the above examination, the vibration element 30 of the micromirror device was manufactured. The manufacturing process is described below. FIGS. 16a to 16f are schematic views showing a longitudinal section of the vibration element 30 in the manufacturing process. First, a Cr layer having a thickness of 0.1 μm is formed as an adhesion layer by the above-described sputtering film formation, and then Cu ₆₄ Zr ₂₈ Ti ₈ is formed to a thickness of 105 μm. Further, a 200-Au layer is formed on Cu ₆₄ Zr ₂₈ Ti ₈ as an antioxidant film. After the sputter film formation, the metal mask is removed, and a support portion of Cu ₆₄ Zr ₂₈ Ti ₈ as shown in FIG. 16a is formed. As described above, since the probability that sputtered particles reach the inside of the opening decreases when the aspect ratio in the opening pattern of the metal mask increases, the torsion bar is lower than the mirror part 4 (thickness 105 μm) having a low aspect ratio. The film thickness of 2 is reduced to 59.5 μm.

Next, 2 μm of Cu layer and 2 μm of Cu ₆₄ Zr ₂₈ Ti ₈ are sputtered on the Au layer. These two layers have a role of preventing the torsion bar 2 from swinging and being broken in the etchant due to foaming during the anisotropic etching of silicon (FIG. 16b). A mask for anisotropic etching of silicon is formed on the back side of the surface on which the support portion made of Cu ₆₄ Zr ₂₈ Ti ₈ is formed. A mask having a Crt layer of 0.1 μm and Cu ₆₄ Zr ₂₈ Ti ₈ of 2 μm is formed on the mirror part and the fixed part by sputtering film formation and photoresist lift-off (FIG. 16c). Thereafter, silicon anisotropic etching is performed using a silicon etchant (Hayashi Pure Chemical Industries, Ltd. Pure etch 160) (FIG. 16d). Next, the Cu layer is removed with a dilute nitric acid solution and the Crt layer is removed with a Cr etchant to form the mirror portion 4 and the substrate 3.

  Next, a sputtering film of Au having a thickness of 200 mm is formed as a reflective film on the surface of the mirror portion 4 (FIG. 16e), and stress relaxation is performed at 200 ° C. for 12 hours using the above-described low-temperature annealing method. And the magnet 12 is fixed to the back side of the mirror part 4 with an adhesive agent, and the vibration element 30 of a micromirror device is completed (FIG. 16f).

A photograph of the vibration element 30 completed by the above process is shown in FIG. The manufactured vibrator was swung by resonance vibration with an electromagnetic coil and scanned with laser light. As shown in FIG. 18, the screen was irradiated with laser light, and the swing angle θ of the mirror portion was calculated from the amplitude. In the vibration element 30 of this example, it was confirmed that it was driven without breaking in a durability test of 10 ⁸ cycles at a resonance frequency of 912.1 Hz and a swing angle θ = ± 30 deg.

  In Examples 1 to 5, a metal glass having a Cu—Zr—Ti composition was used as the metal glass. However, in the present invention, metallic glasses having other compositions can be used. The metal glass that can be used is a metal glass having the following composition.

Al-containing composition: Al-Ni-Ce-Fe, Al-Ni-Y
Au-containing composition: Au-Ag-Pd-Cu-Si, Au-Ge-Si
Ca-containing composition: Ca-Ag, Ca-Cu-Ag-Mg, Ca-Mg-Cu, Ca-Mg-Zn
Ce-containing composition: Ce-Al-Ni-Cu
Co-containing composition: Co- (Al, Ga)-(P, B, Si), Co- (Zr, Hf, Nb) -B, Co-Fe-Si-B-Nb, Co-Fe-Ta-B, Co-Fe-Ta-B-Si, Co-Si-B, Co-Ta-B
Cu-containing composition: Cu- (Zr, Hf) -Ti, Cu- (Zr, Hf) -Ti- (Fe, Co, Ni), Cu- (Zr, Hf) -Ti- (Y, Be), Cu- Hf-Ti, Cu-Pd-Zr-Ag-Al, Cu-Zr, Cu-Zr-Al, Cu-Zr-Al-Ag, Cu-Zr-Al-Nb, Cu-Zr-Ti, Cu-Zr- Ti-Co
Fe-containing composition: (Fe, Co) -B-Si-Nb, Fe- (Al, Ga)-(P, C, B, Si, Ge), Fe- (Cr, Mo)-(C, B)- Ln, Fe- (Nb, Cr, Mo)-(C, B), Fe- (Nb, Mo)-(Al, Ga)-(P, B, Si), Fe- (Zr, Hf, Nb)- B, Fe-B-Si-Nb, Fe-Co-Ln-B, Fe-Ga- (Cr, Mo)-(P, C, B), Fe-Ga- (P, B), Fe-Si- B-Nb, Fe-Si-BP, Fe-Zr-Y-Co-Mo-Al-B
Hf-containing composition: Hf-Al-Ni-Cu, Hf-Al-Ni-Cu-Pd, Hf-Al-Ni-Cu-Pt
La-containing composition: La-Al-Ni-Cu, La-Al-Ni-Cu-Co, La-Al-Ni-P, La-Ni-Al
Mg-containing composition: Mg-Cu-Gd, Mg-Cu-Y, Mg-Cu-Y-Ag-Pd
Nd-containing composition: Nd-Al-Fe-Co
Ni-containing composition: Ni- (Nb, Cr, Mo)-(P, B), Ni- (Nb, Ta) -Zr-Ti, Ni- (Zr, Hf, Nb) -B, Ni-Cu-Ti- Zr-Al, Ni-Nb-Ti-Zr, Ni-Nb-Ti-Zr-Co-Cu, Ni-Si-B, Ni-Ti-Zr-Al
Pd-containing composition: Pd-Cu-Ni-P, Pd-Cu-Si, Pd-Ni-Cu-P, Pd-Ni-Fe-P, Pd-Ni-P, Pd-Pt-Cu-P, Pd- Si, Pd-Si-Cu
Pt-containing composition: Pt-Cu-Co-P, Pt-Cu-Ni-P, Pt-Cu-P, Pt-Ni-P
Ru-containing composition: Ru-Zr-Al, Ru-Zr-Mo
Ti-containing composition: (Ti, Zr, Hf) -Cu-Ni-Si, Ti-Cu- (Zr, Hf)-(Co, Ni), Ti-Cu-Ni-Sn, Ti-Cu-Zr-Pd, Ti-Ni-Cu-B-Si-Sn, Ti-Ni-Cu-Sn, Ti-Zr-Hf-Cu-Ni-Si, Ti-Zr-Cu, Ti-Zr-Ni, Ti-Zr-Fe
Zr-containing composition: Zr-Cu-Ag-Al-Pd, Zr-Cu-Ni-Al-Pd, Zr-Cu-Ni-Ag-Al, Zr-Cu-Ni-Al, Zr-Cu-Ni-Al- Ta, Zr-Nb-Cu-Ni-Al, Zr-Ni, Zr-Ti-Cu-Ni-Al, Zr-Ti-Cu-Ni-Be
In the first to fifth embodiments, the both ends of the mirror unit 4 are coupled to one end of the pair of beam units 2, and the other end of the pair of beam units 2 is coupled to the base 3. 30. However, the vibration element 30 may have a cantilever structure in which one beam portion 2 is coupled to one base body 3 and the mirror portion 4 is coupled to the beam portion 2.

[Embodiment of Actuator Device]
FIG. 19 is a schematic diagram illustrating an example of an actuator device including the vibration element 30, FIG. 19 a is a schematic top view of the vibrator 30, and FIG. 19 b is a cross-sectional view of the actuator device 100 including the vibrator 30. . As shown in FIGS. 19a and 19b, the actuator device 100 is a vibration mirror device, and includes a substrate 110, a holding member 120 on which the substrate 110 is mounted, and a vibration element 30. The holding member 120 is provided with an annular flange 121 along the peripheral edge of the substrate 110, and a central portion thereof constitutes a recess 122. The vibration element 30 is mounted in the recess 122 and is disposed in the decompression space 150 configured (partitioned) by the substrate 110, the holding member 120, and the cover member 140.

  The vibration element 30 includes a base 3, a beam portion 2 that bridges opposite opposite ends of the base 3 so as to straddle the concave portion 122 of the holding member 120, and a swing provided at a portion corresponding to the opening center of the holding member 120. Part 4. The base 3, the beam portion 2, and the swinging portion 4 are integrally formed of metal glass as in the first to third embodiments, for example. A magnet 12 is installed in the lower part of the swing part 4, and an electromagnetic coil 14 is provided on the substrate 110 at a portion facing the swing part 4.

[Embodiment of Image Forming Apparatus]
An embodiment of the image forming apparatus including the vibration element 30 of the present invention will be described in detail below with reference to FIG. 20 applied to a laser beam printer (hereinafter referred to as “LBP”). As shown in FIG. 20, the LBP 200 includes a photosensitive drum 204 as an image forming medium and an exposure unit 210 for forming an electrostatic latent image corresponding to image information on the photosensitive drum 204. In addition to the photosensitive drum 204 and the exposure unit 210, the LBP 200 is a known paper feeding unit, charging unit, toner supply unit, transfer unit, and fixing unit. A paper transport unit (both not shown) is provided. The exposure unit 210 includes an optical scanning device 220 including a laser light source 201 for oscillating a pulsed laser beam L corresponding to image information, a known collimator optical system 202, and an fθ lens 203. A laser beam L from a laser light source 201 of an optical scanning device 220 (described later) is irradiated to the outer peripheral surface of the driving and rotating photosensitive drum 204 through the light reflecting surface of the oscillating body of the vibration element 30, and the rotation axis of the photosensitive drum 204. The laser beam L scans and moves in the parallel direction.

  In FIG. 20, the optical scanning device 220 includes a laser light source 201, a vibration element 30 that scans the laser light L from the laser light source, a drive unit 207 that drives the vibration element 30, and a control that controls the operation of the element drive unit 207. A device 206 is provided. The control device 206 includes a pair of BD sensors 205 that detect the scanned laser light L, outputs a control signal based on the detection signal, and controls the output of the drive unit 207 that drives the vibration element 30.

[Embodiment of Video Projection Device]
An embodiment in which the vibration element 30 of the present invention is applied to a video projector 300 such as an overhead projector will be described with reference to FIG. In the present embodiment, constituent elements having the same functions as those of the embodiment applied to the LBP 200 are given the same reference numerals, and redundant descriptions are omitted. The image projection apparatus 300 in this embodiment is irradiated with light deflected by the optical scanning apparatus 220, the light deflecting apparatus 302 that changes the light from the light source 301 in a predetermined direction, and the light deflecting apparatus 302 that is basically the same as the LBP 200. A screen 304 is provided.

  The light deflector 302 reflects the light reflected by the light reflecting surface (not shown) of the oscillating body (not shown) of the oscillating element 30 of the optical scanning device 220 along a direction parallel to the ideal oscillating axis (not shown). To be deflected. Since the light deflection speed by the light deflecting device 302 can be made relatively slower than the vibration period of the oscillating body (not shown) of the vibration element 30, a known galvanometer mirror is used in this embodiment. Light emitted from the light source 301 including RGB three primary colors is two-dimensionally scanned by the vibration element 30 and the light deflecting device 302 and projected as an image on the screen 304.

  The swing angle α of the light reflecting surface of the oscillating body constituting the main part of the vibration element 30 is adjusted by the drive unit 207 based on a control signal output from the control device 206. Similarly, the deflection angle of the galvanometer mirror about the axis orthogonal to the ideal swing axis of the swinging body is controlled based on the output from the control device 206 in the light deflecting device 302. Image information projected on the screen 304 is transmitted from the input unit 303 to the control device 206, and information regarding the distance of the optical path from the light source 301 to the screen 304 is input from the distance measuring unit 305. The control device 206 sets the projection angle of view and magnification according to the information from the input unit 303 and the distance measuring unit 305 and the size of the image and the aspect ratio of the vibration element 30 and the light deflection device 302. Change each scan angle. Note that the enlargement ratio of the image can also be achieved by on / off control of energization to the light source 301 without changing the scanning angle. However, by reducing the off time of the light source 301 by changing the scanning angle, a high brightness image can be projected onto the screen 304.

1: Si single crystal, 2: beam, 3: substrate, 4: mirror part (oscillating part), 5: Cu, 6: metal mask, 7: opening width, 8: metal mask thickness, 9: cooling plate, 10 : YAG laser oscillator, 11: mirror surface, 12: magnet, 13: laser oscillator, 14: electromagnetic coil, 15: maximum displacement angle of mirror part, 16: twist axis of mirror part, 17: intermediate part, 18 : Pedestal of mirror part, 19: reflective film, 30: vibration element

Claims (16)

A base, a beam provided in a beam shape from the base, and a swinging part provided on the side of the beam opposite to the base,
At least a part of the swinging part and the beam part are integrally formed of metal glass,
A vibrating element characterized by that. The oscillating part and the beam part are separated from each other as a part having different mechanical characteristics and are integrally formed.
The vibrating element according to claim 1. The swing part and the beam part are integrally formed of metal glass,
The oscillating portion includes a first region located within a predetermined distance from a connection site with the beam portion along a direction in which the base body, the beam portion, and the oscillating portion are arranged, and outside the predetermined distance. A second region located at
At least the second region of the oscillating portion is subjected to a heat treatment at a temperature equal to or lower than a temperature at which the metallic glass is crystallized,
The beam portion is not subjected to the heat treatment,
The vibration element according to claim 1, wherein the vibration element is characterized in that The swing part and the beam part are integrally formed of metal glass,
The oscillating portion includes a first region located within a predetermined distance from a connection site with the beam portion along a direction in which the base body, the beam portion, and the oscillating portion are arranged, and outside the predetermined distance. A second region located at
At least the second region of the oscillating portion is subjected to a heat treatment at a temperature lower than the glass transition temperature of the metal glass,
The beam portion is not subjected to the heat treatment,
The vibration element according to claim 1, wherein the vibration element is characterized in that The swing part and the beam part are integrally formed of metal glass,
The rocking part has a higher Young's modulus than the beam part,
The vibration element according to claim 1, wherein the vibration element is characterized in that The swing part and the beam part are integrally formed of metal glass,
The rocking part has a larger free volume than the beam part,
The vibrating element according to claim 1, wherein The swing part includes a pedestal and an optical member bonded to one surface of the pedestal,
The base of the swing part and the beam part are integrally formed of metal glass,
The vibration element according to claim 1, wherein the vibration element is characterized in that The pedestal and the beam portion are integrally formed of metal glass,
The pedestal is positioned outside the predetermined distance from a first region located within a predetermined distance from a connection portion with the beam portion along a direction in which the base body, the beam portion, and the swinging portion are arranged. And a second region to
At least the second region of the pedestal is subjected to a heat treatment at a temperature equal to or lower than a temperature at which the metallic glass is crystallized,
The beam portion is not subjected to the heat treatment,
The vibrating element according to claim 7. The pedestal and the beam portion are integrally formed of metal glass,
The pedestal is positioned outside the predetermined distance from a first region located within a predetermined distance from a connection portion with the beam portion along a direction in which the base body, the beam portion, and the swinging portion are arranged. And a second region to
At least the second region of the pedestal is subjected to a heat treatment at a temperature lower than the glass transition temperature of the metal glass,
The beam portion is not subjected to the heat treatment,
The vibrating element according to claim 7. The rocking part and the base body have a larger thickness than the beam part,
The vibrating element according to claim 1, wherein The swinging part is coupled to a pair of beam parts sandwiching the swinging part,
The vibrating element according to claim 1, wherein A reflective film is formed on the surface of the rocking portion;
The vibrating element according to claim 1, wherein A vibration element according to any one of claims 1 to 12, a drive unit that rocks the rocking unit, and a light source,
The rocking portion has a mirror surface;
Oscillating the oscillating unit by the driving unit, and scanning the light from the light source by the mirror surface;
An optical scanning device. A vibration element according to any one of claims 1 to 12, and a drive unit that rocks the rocking unit,
Oscillating the oscillating unit by the driving unit;
An actuator device characterized by that. A vibration element according to any one of claims 1 to 12, a drive unit that rocks the rocking unit, and a light source,
The rocking portion has a mirror surface;
Oscillating the oscillating unit by the driving unit and projecting an image by scanning the light from the light source with the mirror surface;
A video projection apparatus characterized by that. A vibration element according to any one of claims 1 to 12, a drive unit that rocks the rocking unit, and a light source,
The rocking portion has a mirror surface;
Oscillating the oscillating unit by the driving unit, and scanning the light from the light source with the mirror surface to form an image;
An image forming apparatus.