JP2005181926A - Optical deflector and its manufacturing method, and optical equipment using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical deflector which is small-sized and low in power consumption and has a hollow part capable of controlling the position of a magnetic body with high precision. <P>SOLUTION: The optical deflector is constituted by supporting both ends of a movable plate on a base substrate by elastic support parts so that the movable plate has free torsional vibration around a torsion axis and forming a reflecting surface on one side of the movable plate, and drives the movable plate relatively to the base substrate to deflect incident light which is incident on the reflecting surface. The movable plate has at least one or more hollow parts formed thereon. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical deflector that deflects incident light, a manufacturing method thereof, and an optical apparatus using the same.

  In recent years, as represented by high integration of semiconductor devices, with the development of microelectronics, various devices have been miniaturized with high functionality. For example, high-functionality and miniaturization have been achieved in image display devices such as laser beam printers and head mounted displays that perform optical scanning using an optical deflector, and light input devices such as barcode readers. There is a demand for further miniaturization. For example, Patent Literature 1 and Patent Literature 2 have been proposed as optical deflectors that satisfy these requirements.

  FIG. 8 is a perspective view showing a first conventional optical deflector disclosed in Patent Document 1. In FIG.

  A scanning mirror 1001 of this optical deflector has a rectangular flat plate shape, and a mirror surface portion 1002 capable of reflecting light by vapor-depositing aluminum or the like is formed on one surface of a glass plate 1009, and SmCo (samarium cobalt) or the like is formed on the other surface. A rare earth permanent magnet 1003 is formed into a thin film by sputtering or the like. A support member 1004 formed into a strip shape by a thin metal plate such as stainless steel or beryllium copper is fixedly supported at one end thereof in the center of both end portions in the longitudinal direction of the mirror surface portion 1002 and the other end portion is attached to the apparatus. The scanning mirror 1001 is fixed to a main body (not shown), and the scanning mirror 1001 can be angularly displaced about a torsion shaft 1005 connecting the two supporting members 1004 by twisting the two supporting members 1004. Further, the permanent magnet 1003 is magnetized so that both sides of the drive shaft 1005 have different polarities as shown in FIG.

  The magnetism generation unit 1006 has a configuration in which a coil 1007 is wound around a coil frame 1008, and is arranged at a predetermined distance on the other surface side of the scanning mirror 1001 on which the permanent magnet 1003 is formed. Accordingly, when the coil 1007 is energized to generate magnetism from the magnetism generation unit 1006, attraction and repulsion force acts between the magnetic poles of the permanent magnet 1003, and the scanning mirror 1001 is arbitrarily selected according to the magnetism generated in the magnetism generation unit 1006. It is driven to be displaced to an angle of.

  On the other hand, FIG. 9 is an exploded perspective view showing a second conventional optical deflector disclosed in Patent Document 2. In FIG.

  As shown in FIG. 9, the base 2002 of the optical deflector 2001 has a flat rectangular shape, and a standing portion 2003 is integrally formed on the entire outer peripheral end of the base 2002, and this standing portion 2003 is formed. A vibrating body 2005 is disposed on the top.

  The vibrating body 2005 includes a rectangular outer frame portion 2006, a reflection mirror portion 2007 in which a light reflection surface 2007a disposed in the opening portion 2006a of the outer frame portion 2006 is formed, and the reflection mirror portion 2007. It is comprised from a pair of support part 2008 which connects the reflective mirror part 2007 and the outer frame part 2006 in the position on the axis | shaft which passes substantially gravity center. The outer frame portion 2006 is fixed on the standing portion 2003, and the reflection mirror portion 2007 is configured to be swingable with a pair of support portions 2008 as a torsion axis CL (FIG. 9).

Further, on the back surface of the reflection mirror portion 2007, a mirror side comb tooth portion 2009 including a groove 2009a and a projection portion 2009b extending in a direction orthogonal to the torsion axis CL is formed. A pair of left and right fixed electrodes 2010 and 2011 are arranged at a position on the base 2002 facing the mirror side comb-tooth portion 2009 of the reflection mirror portion 2007, and a groove 2012a and a groove 2012a are also formed on the upper surface side of the pair of fixed electrodes 2010 and 2011. An electrode side comb tooth portion 2012 including the protrusion portion 2012b is formed. The mirror-side comb-tooth portion 2009 and the electrode-side comb-tooth portion 2012 are arranged such that one groove 2009a, 2012a and the other protrusion 2009b, 2012b are engaged with each other. A voltage can be selectively applied between the fixed electrodes 2010 and 2011 and the reflection mirror unit 2007 via the changeover switches SW1 and SW2. Accordingly, by alternately switching on and off the changeover switches SW1 and SW2 and alternately applying a voltage to the pair of fixed electrodes 2010 and 2011, the reflection mirror unit 7 pivots the pair of support units 2008 about the torsion axis CL. Swing as.
Japanese Patent Laid-Open No. 06-82711 JP 2000-147419 A

  However, the first and second conventional examples have the following problems.

  In the first conventional example, in order to drive the mirror surface portion 1002 at a high speed and a high deflection angle, it is desirable that the moment of inertia around the torsion axis 1005 of the scanning mirror 1001 is smaller. If it is attempted to reduce the moment of inertia of the scanning mirror 1001 with the configuration of the first conventional example, it is conceivable to make the support member 1004 thinner, but at the same time, the rigidity also decreases. Therefore, the scanning mirror 1001 that is torsionally vibrated at high speed is greatly bent due to inertial force due to its own weight during driving, and it is difficult to achieve both high-speed and high deflection angle driving and the optical characteristics of the deflector.

  Further, when a large generated force is required, the thickness of the permanent magnet 1003 must be increased, so that not only the moment of inertia of the scanning mirror 1001 is remarkably increased, but also the center of gravity of the torsion shaft 1005 and the scanning mirror 1001. There is a problem in that stable torsional vibration cannot be obtained.

  In the second conventional example, in order to drive the reflection mirror unit 2007 at a high deflection angle, in order to avoid interference between the reflection mirror unit 2007 and the base 2002, the projections 2009b of the mirror side comb teeth and the electrode side comb teeth Each portion 2012b needs to have a sufficient height. Therefore, structurally, the moment of inertia of the reflection mirror unit 2007 inevitably increases with a high deflection angle, and there is a problem that it is difficult to achieve both high speed and high deflection angle driving characteristics. Further, since the back surface shape is not flat, there is a problem that the resonance motion is reduced due to the air resistance and the power consumption is increased.

  Furthermore, in the second conventional example, an actuator driven by an electrostatic force requires a higher voltage than an actuator driven by an electromagnetic force, so the power supply unit must be enlarged. Therefore, even if the optical deflector can be miniaturized, there is a problem that the device for driving cannot be miniaturized and the entire device becomes large.

  The present invention has been made in view of the above-mentioned conventional problems, and its purpose is that it can be driven at a high speed, has a large deflection angle, is excellent in static flatness on an anti-slope, and has little distortion even during high-speed operation. Another object of the present invention is to provide a small-sized optical deflector that can be driven at a low voltage, a manufacturing method thereof, and an optical apparatus using the same.

  An object of the present invention is to support a movable substrate with both ends of a movable plate supported by an elastic support portion so as to be able to torsionally vibrate about a torsion axis. A reflective surface is formed on one surface of the movable plate, and Is formed with a magnetic material, and has a magnetism generating means in the vicinity of the magnetic material, and the movable plate is driven relative to the support substrate by the magnetism generating means and is incident on the reflecting surface. An optical deflector for deflecting incident light, wherein the movable plate has a hollow structure, the weight is reduced to reduce the moment of inertia, and the magnetic body is formed in the hollow portion to reduce air resistance. This is achieved by the featured optical deflector.

  Further, the object of the present invention is to support the support substrate so that both ends of the movable plate are torsionally vibrated around the torsion axis by the elastic support portion, and a reflective surface is formed on one surface of the movable plate. A magnetic body is formed on the surface, and magnetism generating means is provided in the vicinity of the magnetic body, and the movable plate is driven relative to the support substrate by the magnetism generating means to An optical deflector for deflecting incident light, wherein the movable plate is formed with a plurality of hollow structures to maintain rigidity while reducing the weight to reduce the moment of inertia so that the magnetic body is formed into the hollow portion. This is achieved by an optical deflector characterized in that it reduces air resistance.

  Another object of the present invention is to form a mask layer on both surfaces of the silicon substrate, leaving the mask layer on the surface of the mask layer on which the reflective surface is formed, the support substrate, the elastic support portion, and the outer portion of the movable plate. Removing the mask layer on the opposite side of the mask layer from the surface on which the reflective surface is formed, leaving the outer portions of the support substrate, the elastic support portion and the movable plate, and the concave portion of the movable plate. Removing the mask layer, performing a dry etching process on the silicon substrate by ICP (inductively coupled plasma) discharge, thereby separating the silicon substrate into a support substrate, an elastic support portion, and a movable plate, A recess is formed on one surface, a lid is covered with a lid member and sealed to form a hollow portion, a mask layer of the silicon substrate is removed, and a reflective surface of the movable plate is opposed to the surface on which the reflective surface is formed. Forming a film, it is accomplished by the manufacturing method of an optical deflector which comprises a step of forming a magnetic body in the hollow portion.

  The optical deflector of the present invention was processed from the side opposite to the reflecting surface of the movable plate and covered to form a hollow part. As a result, high rigidity can be secured while reducing the weight, the moment of inertia of the movable plate can be reduced, and the rigidity of the movable plate can be further increased by forming a magnetic body in the hollow portion. Further, by forming the magnetic body in the hollow portion whose position can be controlled with high accuracy, it is possible to suppress variations in characteristics among products.

  Compared with the case where a magnetic body is installed on the surface of the movable plate, the magnetic body can be brought closer to the torsion shaft, and the moment of inertia of the movable plate can be reduced.

  Therefore, it is possible to realize a small optical deflector that can be driven at high speed, can reduce power consumption even at a large deflection angle, and has little deformation of the reflecting surface even at high speed operation.

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

(First embodiment)
(Overall description, mirror)
FIG. 1 is a perspective view showing a configuration of a first embodiment of an optical deflector according to the present invention. In FIG. 1, the optical deflector 1 has a structure in which both ends of a movable plate 5 are supported on a support substrate 2 by elastic support portions 3. The elastic support part 3 supports the movable plate 5 elastically about the C axis (that is, the torsion axis) in a torsional vibration manner in the E direction. Further, one surface of the movable plate 5 is a reflective surface 4, and the incident light incident on the reflective surface 4 is deflected by a predetermined displacement angle by the twist of the movable plate 5 in the E direction. 1 indicates a direction perpendicular to the torsion axis C and parallel to the surface on which the reflecting surface 4 of the movable plate 5 is formed. In particular, the arrow direction of B is the “movable plate width direction”. "

(Magnet, hollow part)
Further, the movable plate 5 is formed with a hollow portion 9 which will be described later by sealing with a lid member 10 from the side opposite to the surface on which the reflecting surface 4 is formed (hereinafter referred to as the back surface). Further, a permanent magnet 8 to be described later, for example, a rare earth permanent magnet containing samarium-iron-nitrogen is embedded in the hollow portion. The permanent magnet 8 is magnetized with a different polarity across the torsion axis C.

(Integrated, mirror substrate)
The support substrate 2, the movable plate 5, the reflecting surface 4, the elastic support portion 3, and the hollow portion 9 described later are all formed of single crystal silicon by a micromachining technique using a semiconductor manufacturing technique.

(Description of coil substrate)
In addition, the coil substrate 6 is installed in parallel to the support substrate 2 so that the coil 7 is arranged in the vicinity with a desired distance from a permanent magnet 8 described later. As shown in FIG. 1, the coil 7 is integrally formed on the surface of the coil substrate 6 by electroplating, for example, copper in a spiral shape.

(Operation)
The operation of the optical deflector 1 of this embodiment will be described with reference to FIG. FIG. 2 is a cross-sectional view taken along line AA of the optical deflector 1 of FIG. As shown in FIG. 2, the permanent magnet 8 is magnetized so as to have different polarities across the torsion axis C, and the direction thereof is as illustrated, for example. When the coil 7 is energized, the magnetic flux Φ is generated in the direction of FIG. Attraction and repulsion are generated in the magnetic poles of the permanent magnet 8 in the direction related to the magnetic flux, respectively, and torque T acts on the movable plate 5 elastically supported around the torsion axis C. Similarly, if the direction of the current applied to the coil 7 is reversed, the torque T works in the opposite direction. Therefore, as shown in FIG. 2, it is possible to drive the movable plate 5 at an arbitrary angle according to the current supplied to the coil 7.

(resonance)
Further, the movable plate 5 can be continuously torsionally vibrated by passing an alternating current through the coil 7. At this time, if the frequency of the alternating current is substantially matched with the resonance frequency of the movable plate 5 and the movable plate 5 is resonated, a larger angular displacement can be obtained.

(scale)
The optical deflector 1 according to the present embodiment is driven at, for example, a resonance frequency of the movable plate 5 of 20 kHz and a mechanical displacement angle ± 11 °. The support substrate 2, the movable plate 5, and the elastic support portion 3 are all configured with an equal thickness of 200 μm. The width of the movable plate 5 in the B direction is 1.4 mm and the length in the torsional axis direction is 1.2 mm. The length of the elastic support portion 3 is 2500 μm and the width is 72 μm.

(Description of detailed configuration of movable plate)
As shown in FIG. 2, in this embodiment, the width from the back side of the movable plate 5 is 1.3 mm, and the length is 1.1 mm.
A hollow structure is formed by etching 100 μm in the depth direction and covering with a lid member 10 (thickness 50 μm) of a silicon plate. Further, in the formed hollow portion 9, a permanent magnet 8 is embedded and installed parallel to the direction B in FIG.

(Effect of hollow part)
In the present embodiment, the weight is reduced and the moment of inertia around the torsion axis C is smaller than when the movable plate 5 is a simple rectangular parallelepiped having no hollow portion. In particular, the moment of inertia is determined by the sum of the mass of the movable plate 5 and the square of the distance from the torsion axis C, and therefore the farther from the torsion axis C in the hollow portion 9 of FIG. The moment of inertia can be effectively reduced by adopting a configuration in which the mass of is reduced.

(Effect of lid member)
Further, in the present invention, by joining the flat lid member 10, the back surface shape becomes flat and the air resistance can be reduced. As a result, the Q value of the resonance motion can be increased and the power consumption can be reduced.

(Magnet shape / mirror rigidity UP)
Furthermore, the permanent magnet 8 of the present embodiment is formed by being embedded in a hollow portion 9 formed in the movable plate 5. Therefore, it is possible to effectively supplement the rigidity of the movable plate 5 that has been lowered by forming the hollow portion 9. In particular, the direction B in FIG. 1 and the permanent magnet 8 formed here are in the same direction. In this case, the rigidity of the movable plate 5 can be increased without greatly increasing the moment of inertia of the movable plate 5.

  Further, when the Young's modulus is larger than the material for which the permanent magnet 8 forms the movable plate 5 (single crystal silicon in the optical deflector 1 of the present embodiment), the movable plate 5 is a simple rectangular parallelepiped having no hollow portion 9. Compared to the case, it is possible to give the movable plate 5 high rigidity.

  Moreover, in this embodiment, compared with the case where the permanent magnet 8 is installed on the surface of the movable plate 5, the permanent magnet 8 can be brought closer to the torsion axis C, and the moment of inertia of the movable plate 5 can be reduced. .

  In addition, since the center of gravity of the movable plate 5 approaches the torsion axis C, stable torsional vibration with less unnecessary vibration can be achieved.

(Relationship with magnet shape and torque)
Moreover, the shape of the permanent magnet 8 of the optical deflector 1 of this embodiment also has a preferable effect from the viewpoint of generated torque. The permanent magnet 8 formed on the movable plate 5 is desirably a magnet having as large a residual magnetic flux density as possible in order to increase the generated torque. In general, since a magnet is subjected to a self-demagnetizing action due to its shape, for example, assuming a cylindrical magnet, the one having a larger ratio L / D between its diameter D and length L (so-called shape having a large permeance coefficient) However, it is known that the self-demagnetizing action is small and the magnet has a large residual magnetic flux density. The permanent magnet 8 of the present invention is formed by being embedded in the hollow portion in parallel with the direction B in FIG. 1, and has a small self-demagnetizing action and a large residual magnetic flux density, and an actuator having a large generated torque. Can be configured.

  In FIG. 1, although the reflecting surface 4 is used as the light deflecting element, an optical deflector that performs the same operation by the torsional vibration of the movable plate 5 can be configured even if the reflecting surface 4 is a reflective diffraction grating. In this case, since the deflected light becomes diffracted light with respect to the incident light, a plurality of deflected lights can be obtained with one beam. In the following embodiments, the case where the light deflection element is the reflecting surface 4 will be described in particular. However, in all of the following embodiments, a reflection type diffraction grating may be substituted.

(Manufacturing method)
Next, the manufacturing method of the movable plate of the first embodiment will be described with reference to FIGS. FIGS. 4A to 4E are views of dry etching of silicon using the ICP-RIE (Inductively Coupled Plasma-Reactive Ion Etching) apparatus of the elastic support portion 106, the movable plate 105, and the hollow portion 104 in the first embodiment. It is process drawing which shows a manufacturing method. In particular, a schematic view of each step of the cross section taken along line AA in FIG. 1 is shown. First, as shown in FIG. 4A, a silicon oxide mask layer 102 is formed on both sides of a flat silicon substrate 101 by a low pressure chemical vapor deposition method or the like. Next, the resist 103 is patterned according to the outer shape of the portions where the movable plate 105 and the elastic support portion 106 are to be formed.

  Next, as shown in FIG. 4B, the resist 103 is patterned according to the outer shape of the portion where the hollow portion 104 is to be formed. Thereafter, as shown in FIG. 4C, the silicon oxide layer 103 is patterned by wet etching using, for example, BHF (buffered hydrofluoric acid). First, as shown in FIG. 4D, the hollow portion 104 (depth of 100 μm) is formed by dry etching using a gas (for example, SF6 / C4F8) that erodes the ICP-RIE silicon substrate. Next, as shown in FIG. 4D, the silicon substrate is inverted, and the movable plate 105 and the elastic support 106 are removed by dry etching using a gas (for example, SF6 / C4F8) that also erodes the silicon substrate of ICP-RIE. Form. Then, the mask layer 102 of the silicon oxide layer is removed.

  Next, as shown in FIG. 4E, a metal (for example, aluminum) 107 having a high reflectance as a reflecting surface is vacuum-deposited. Thereafter, a wire rod of a metal magnet (for example, iron-cobalt-chromium alloy, etc.) that can be easily processed is cut into a desired length and bonded to the hollow portion 104 with an adhesive or the like. Thereafter, magnetization (see FIG. 2 for the magnetization direction) is performed to form a permanent magnet 108, and a lid member 109 (thickness 50 μm) of a silicon plate having the same dimensions as the movable plate is adhered and sealed with an adhesive or the like. And the optical deflector of FIG. 4 is completed by setting it as a hollow structure.

(Effects from manufacturing method)
According to the manufacturing method of the optical deflector of the first embodiment, since the hollow portion 104 can be processed by dry etching, the depth can be adjusted by adjusting the photolithographic mask pattern and the etching time even for a design change or the like. It becomes possible to respond. Also, since the lid is made of the same silicon, the rigidity can be increased without any distortion after sealing. Further, since the surface of the lid is flat, it is possible to prevent the resonance motion due to air resistance from being reduced.

  Since both the movable plate 105 and the elastic support portion 106 can be processed by dry etching, there are similar effects on design changes and the like.

  By forming the permanent magnet 7 by cutting a wire having a circular cross section, it is possible to manufacture with high processing accuracy and at low cost.

(Second Embodiment)
FIG. 3 is a cross-sectional view showing a second embodiment of the optical deflector of the present invention. The optical deflector 1 of this embodiment has the same basic driving principle as that of the optical deflector 1 of the first embodiment. Further, similarly to the first embodiment, it is formed of single crystal silicon by a micromachining technique using a semiconductor manufacturing technique.

(Difference in structure)
The difference from FIG. 2 is that a plurality of the hollow portions 11 of FIG. 3 are formed, and this point will be particularly described here.

(Description of detailed configuration of movable plate)
As shown in FIG. 3, in the present embodiment, 100 μm etching is performed from the back surface side of the movable plate 5 to form three concave shapes, and then the lid is covered with a silicon plate lid member (thickness 50 μm) of the same size as the movable plate. By doing so, a plurality of (three places) hollow structures are obtained. Further, a permanent magnet 8 is embedded in the center of the plurality of formed hollow portions 11 so as to be parallel to the B direction as in FIG.

(Effect of hollow part)
In this embodiment, compared with the case where the movable plate 5 is a simple rectangular parallelepiped that does not have a hollow portion, the weight is reduced similarly to the first embodiment, and the moment of inertia is reduced. Furthermore, since it is a plurality of hollow structures, the rigidity is further improved and the weight can be reduced.

(The effect)
The hollow portion 11 and the permanent magnet 8 of the present embodiment have the same effects as the hollow portion 9 and the permanent magnet 8 of the first embodiment. In addition, in the second embodiment, since the hollow portion is also formed in a concave shape at the center of the movable plate 5, the rigidity is improved as compared with the first embodiment. Furthermore, in the second embodiment, since the permanent magnet 8 having a circular cross section is configured to be fitted into the hollow portion formed in a concave shape, the positional accuracy of the permanent magnet 8 can be increased. As a result, variations in the characteristics of the optical deflector, such as generated torque and resonance frequency, between products can be suppressed, so that an optical deflector with less disturbance can be realized.

(Manufacturing method)
Next, a method for manufacturing the movable plate according to the second embodiment will be described with reference to FIGS. 5 (a) to 5 (e) show the results of dry etching of silicon using the ICP-RIE (Inductively Coupled Plasma-Reactive Ion Etching) apparatus of the elastic support portion 206, the movable plate 205, and the hollow portion 204 in the second embodiment. It is process drawing which shows a manufacturing method. In particular, a schematic view of each step of the cross section taken along the line AA of FIG. First, as shown in FIG. 5A, a silicon oxide mask layer 202 is formed on both sides of a flat silicon substrate 201 by a low pressure chemical vapor synthesis method or the like. Next, the resist 203 is patterned according to the outer shape of the portions where the movable plate 205 and the elastic support portion 206 are to be formed.

  Next, the resist 203 is patterned according to the outer shape of the portion where the plurality of hollow portions 204 are to be formed. Thereafter, as shown in FIG. 5B, the silicon oxide layer 203 is patterned by wet etching using, for example, BHF (buffered hydrofluoric acid).

  Then, as shown in FIG. 5C, a plurality of hollow portions 204 (depth of 100 μm) are formed by dry etching using a gas (for example, SF6 / C4F8) that erodes the ICP-RIE silicon substrate. Next, as shown in FIG. 5D, the silicon substrate is inverted, and the movable plate 205 and the elastic support portion 206 are removed by dry etching using a gas (for example, SF6 / C4F8) that also erodes the silicon substrate of ICP-RIE. Form. Then, the mask layer 202 of the silicon oxide layer is removed.

  Next, as shown in FIG. 5E, a metal (for example, aluminum) 207 having a high reflectivity is vacuum-deposited as a reflective surface. Thereafter, a wire rod of a metal magnet (for example, iron-cobalt-chromium alloy, etc.) that can be easily processed is cut into a desired length, and bonded to the hollow portion at the center of the plurality of hollow portions 204 with an adhesive or the like. Thereafter, magnetization (see FIG. 2 for the magnetization direction) is similarly performed to form the permanent magnet 208, and a silicon plate lid member 209 (thickness 50 μm) having the same dimensions as the movable plate is adhered with an adhesive or the like. The optical deflector shown in FIG. 5 is completed by sealing and forming a plurality of hollow structures.

(Effects from manufacturing method)
According to the method of manufacturing the optical deflector of the second embodiment, the plurality of hollow portions 204 can be processed by dry etching as in the first embodiment. Therefore, the photolithographic mask pattern and etching can be applied to a design change or the like. The depth can be adjusted by adjusting the time. Furthermore, since there are a plurality of hollow portions, the central hollow portion becomes a beam of the movable plate, and thus the rigidity is improved as compared with the first embodiment.

  Further, since the center hollow beam adheres to the lid after sealing with the same silicon material, the flatness of the surface of the lid is further maintained, so that the resonance motion due to air resistance can be reduced.

  Since both the movable plate 205 and the elastic support portion 206 can be processed by dry etching, the same effect as that of the first embodiment with respect to the design change or the like can be obtained.

It is a perspective view which shows 1st, 2nd embodiment of the optical deflector of this invention. It is sectional drawing in the AA line of Embodiment 1 of FIG. It is sectional drawing in the AA line of Embodiment 2 of FIG. (A)-(e) is a figure explaining the manufacturing method of the optical deflector of FIG. (A)-(e) is a figure explaining the manufacturing method of the optical deflector of FIG. It is a figure which shows one Embodiment of the optical instrument using the optical deflector of this invention. It is a figure which shows other embodiment of the optical instrument using the optical deflector of this invention. It is a figure which shows the optical deflector of a 1st prior art example. It is a figure which shows the optical deflector of the 2nd prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical deflector 2 Support substrate 3 Elastic support part 4 Reflecting surface 5 Movable plate 6 Coil board permanent magnet 7 Coil 8 Permanent magnet 9 Hollow part of Embodiment 1 10 Lid member (silicon plate)
11 A plurality of hollow portions of Embodiment 2 101 Silicon substrate 102 Silicon oxide layer 103 Photoresist layer 104 Hollow portion (Embodiment 1)
105 Movable plate 106 Elastic support portion 107 Aluminum layer 108 Permanent magnet 109 Lid member (silicon plate)
201 Silicon substrate 202 Silicon oxide layer 203 Photoresist layer 204 Multiple hollow parts (Embodiment 2)
205 Movable plate 206 Elastic support portion 207 Aluminum layer 208 Permanent magnet 209 Lid member (silicon plate)
DESCRIPTION OF SYMBOLS 301 Optical deflector group 302 Laser light source 303 Lens 304 Writing lens 305 Projection surface 306 Photosensitive body 1001 Scanning mirror 1002 Mirror surface part 1003 Permanent magnet 1004 Support member 1005 Torsion shaft 1006 Magnetic generation part 1007 Coil 1008 Coil frame 1009 Glass plate 2001 Optical deflector 2002 Base 2003 Standing portion 2005 Vibrating body 2006 Outer frame portion 2007 Reflecting mirror portion 2008 Support portion 2009a Groove 2009b Protruding portion 2010 Fixed electrode 2011 Fixed electrode 2012 Electrode side comb tooth portion

Claims (19)

On the support substrate,
Both ends of the movable plate are supported by the elastic support part so that the torsional vibration is possible around the torsion axis,
A reflective surface is formed on one surface of the movable plate,
Driving the movable plate relative to the support substrate;
An optical deflector for deflecting incident light incident on the reflecting surface,
At least one hollow portion is formed in the movable plate;
An optical deflector characterized by.   The optical deflector according to claim 1, wherein the hollow portion has a structure in which a flat lid member is joined to a concave portion formed in the movable plate. A magnetic body is formed in the hollow portion,
In the vicinity of the magnetic body, there is a magnetism generating means,
Driving the movable plate by the magnetism generating means;
The optical deflector according to claim 1 or 2. The magnetic body is a permanent magnet,
The magnetism generating means includes a coil wound on a second support substrate,
The optical deflector according to claim 3, wherein The hollow portion where the permanent magnet is formed is
The movable plate width direction (however, it is horizontal to the movable plate and perpendicular to the torsion axis),
The optical deflector according to claim 4, wherein the width is narrower than the length of the optical deflector.   The optical deflector according to any one of claims 1 to 5, wherein the hollow portions are arranged substantially in parallel along a torsional axis direction of the elastic support portion.   The optical deflector according to claim 1, wherein the support substrate, the elastic support portion, the movable plate, and the hollow portion are formed of single crystal silicon.   6. The optical deflector according to claim 4, wherein the magnetic body has a substantially circular cross section perpendicular to the movable plate width direction.   The optical deflector according to claim 1, wherein the magnetic body is an alloy containing nickel and cobalt.   The optical deflector according to claim 1, wherein the magnetic body includes a rare earth element.   The optical deflector according to claim 1, wherein the magnetic body contains samarium, iron, and nitrogen.   The optical deflector according to claim 1, wherein the magnetic body is an alloy containing iron, chromium, and cobalt.   An optical apparatus comprising the optical deflector according to claim 1.   An optical deflector or a group of optical deflectors in which at least one optical deflector according to any one of claims 1 to 13 for deflecting light emitted from the light source is disposed. An image display apparatus that projects at least a part of light deflected by a projector or a group of optical deflectors onto an image display body. Forming a mask layer on both sides of the silicon substrate;
Removing the mask layer on the surface of the mask layer that forms the reflective surface, leaving the outer portion of the support substrate, the elastic support portion, and the movable plate;
The mask layer on the opposite side of the mask layer from the surface that forms the reflective surface is removed leaving the outer portion of the support substrate, the elastic support portion, and the movable plate, and the mask layer in the concave portion of the movable plate is removed. The process of
Processing the silicon substrate by etching and separating it into a support substrate, an elastic support portion and a movable plate;
Forming a recess on one surface of the movable plate;
Forming a hollow portion by joining and sealing a lid member to the recess,
Forming a reflective film on a surface forming a reflective surface of the movable plate;
The manufacturing method of the optical deflector characterized by including.   16. The method of manufacturing an optical deflector according to claim 15, wherein the etching is dry etching by ICP (inductively coupled plasma) discharge.   The method of manufacturing an optical deflector according to claim 15, comprising a step of forming a magnetic body in the hollow portion.   The step of forming the magnetic body includes a step of applying a mixture of a magnetic powder and a bonding material fixing the powder to the hollow portion and heating the mixture in a magnetic field. 18. A method for manufacturing an optical deflector according to item 17.   The method of manufacturing an optical deflector according to claim 17, wherein the step of forming the magnetic body includes an electroplating step.

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