JP2003029190A - Optical deflector, image display device and imaging device using the same, and method for manufacturing optical deflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive optical deflector, capable of large displacement and quick operation and has high energy efficiency. SOLUTION: The optical deflector is provided with a mobile plate 109, having a mirror 111, a torsion spring part 107 which supports the mobile plate 109 oscillatably about the center of rotation, a support substrate 101 which supports the torsion spring part 107, and a oscillation means, which includes a fixed core 104 placed apart from the mobile plate 109 and is fixed to the support substrate 101 and a coil 105 wound around the fixed core 104 and shakes the mobile plate 109. The oscillation means includes a mobile core 106 added to the mobile plate 109. The mobile core 106 is set on a side face, off the center of rotation of the mobile plate 109 and forms a series magnetic circuit, together with the fixed core 104. The mobile plate 109, the torsion spring part 107, and the support substrate 101 are made of single-crystal silicon. A bisecting face 136 of the mobile core 106 and a bisecting face 134 of the fixed core 104 have different heights.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical deflector using an electromagnetic actuator, an image display device and an image forming apparatus using the same, and a method for manufacturing the optical deflector.

[0002]

2. Description of the Related Art Recently, attempts have been made to manufacture an electromagnetic actuator on a substrate such as silicon by utilizing a semiconductor process. When the electromagnetic actuator is manufactured using the semiconductor process, the stator, the mover, and the electromagnetic coil can be manufactured at once, and the steps of joining and adhering are unnecessary, and the stator, the mover, and the electromagnetic coil can be manufactured with high accuracy. Can be aligned. In addition, cost reduction can be expected because a large amount can be manufactured at one time.

An optical deflector is one of application examples of an electromagnetic actuator formed on a substrate. The optical deflector is used for an image forming apparatus such as a laser beam printer, an image display apparatus such as a head mounted display, and an image input apparatus such as a bar code reader.

Japanese Patent Laid-Open No. 2000-235152 shows an example in which an electromagnetic actuator manufactured on a substrate is applied to an optical deflector. FIG. 9 is a top view showing an optical deflector described as one of the embodiments in Japanese Patent Laid-Open No. 2000-235152.
This is a torsion beam deflector,
Used as a two-dimensional scanning deflector. This torsion beam optical deflector is composed of an inner y-axis direction deflector 1003 and an outer x-axis direction deflector 1004. Inner y
The axial deflection unit 1003 swings the substrate 1001 having the groove 1002, the movable plate 1006 swingably supported by the shaft 1005 and having a thin film showing hard magnetism formed on the surface thereof, and the movable plate 1006. It is composed of a pair of thin film electromagnet portions 1007 and a mirror 1008 provided on the movable plate 1006. The movable plate 1006 and the surface on which the thin film electromagnet portion 1007 is formed are slightly displaced in the thickness direction. Coulomb generated between the magnetic field generated by applying an alternating current of 60 kHz, which is the structural resonance frequency of the y-axis direction deflection section 1003, to the thin film electromagnet section 1007 and the magnetic field generated by the hard magnetic thin film formed on the movable plate 1006. The movable plate 1006 is swung by force, and the irradiation light is deflected by the mirror 1008. Since the driving method uses mechanical resonance, low power consumption can be realized. The outer x-axis direction deflection unit 1004 has the same structure as the y-axis direction deflection unit 1003, and the driving method is also the same. Drive frequency: 60kHz (y axis), 60Hz (x axis), deformation angle: ± 13.67 ° (y direction).

There is also an attempt to miniaturize an electromagnetic actuator by using a semiconductor process and a permanent magnet, and applying this to an optical deflector. A magnetic field can be formed relatively easily by using a permanent magnet, and high-speed operation can be expected by reducing the weight of the mover. As an example, there is Japanese Patent Laid-Open No. 7-175005. FIG. 10 is a diagram of Japanese Patent Laid-Open No. 7-175005.
It is a top view which shows the optical deflector described as one of the examples in the publication. In this optical deflector, a flat movable plate having a mirror is supported by two torsion springs so as to be swingable with respect to the substrate. In FIG. 10, 801 is a galvano mirror, 802 is a silicon substrate, 803 is an upper glass, 804 is a lower glass, 805 is a movable plate, 806 is a torsion spring, 807 is a flat coil, 808 is a total reflection mirror, and 809 is a contact pad. , 810A, 811A are permanent magnets, respectively. The movable plate 805 is provided with a driving plane coil 807 that generates a magnetic field by energizing the periphery thereof, so as to apply a static magnetic field only to both sides of the driving plane coil parallel to the axial direction of the torsion spring 806. , Paired permanent magnets 810A, 810B; 811A, 810C on the upper and lower surfaces of the semiconductor substrate.
Are installed via upper and lower glass substrates 803 and 804.
In this optical deflector, the driving plane coil 807 is energized, and the current flowing through the plane coil 807 and the permanent magnets 810A, 810B; 811
Depending on the direction of the magnetic flux density by A and 810C, the Lorentz force F (not shown) acts in the direction according to Fleming's left-hand rule, and a moment for swinging the movable plate 805 is generated.
When the movable plate 805 swings, a spring reaction force F ′ (not shown) is generated due to the spring rigidity of the torsion spring 806. Plane coil 80
The movable plate 805 having a light reflecting surface oscillates by scanning the electric current flowing through 7 continuously and repeatedly, and the reflected light is scanned.

[0006]

However, each of the above-mentioned optical deflectors has the following problems.

The optical deflector of Japanese Patent Laid-Open No. 2000-235152 shown in FIG. 9 realizes high speed operation, but the core forming the thin film electromagnet section 1007 is a thin film formed by sputtering. However, there is a limit to increasing the cross-sectional area.
Therefore, when a large current is applied to the thin film electromagnet section 1007, the magnetic flux is saturated and it is difficult to further increase the deformation angle. In addition, the movable plate 1006 and the thin film electromagnet section 10
Since the deviation of the 07 forming surface in the thickness direction is slight, it is difficult to further increase the deformation angle also from this point.

In the optical deflector of Japanese Patent Laid-Open No. 7-175005 shown in FIG. 10, when an attempt is made to increase the deflection angle of light when scanning light, the upper and lower glass substrates 803 and 804 and the movable plate are arranged.
You have to increase the distance from the 805. Permanent magnet 810
When the relative distance between the A and 811A and the driving plane coil 807 increases, the magnetic flux density in the plane coil 807 decreases and a large current is required for driving.

An object of the present invention is to solve the above-mentioned problems in the prior art, to provide an optical deflector which is capable of large displacement, can operate at high speed, has high energy efficiency, and is inexpensive.

[0010]

According to the present invention, in order to solve the above-mentioned problems, a movable plate having a deflecting portion for deflecting incident light and a movable plate around a rotation center (swing center) are provided. An elastic supporting portion for supporting the movable plate, a supporting substrate for supporting the elastic supporting portion, and a rocking means for rocking the movable plate having a portion located apart from the movable plate. In the optical deflector provided with, the swinging means has a movable core attached to the movable plate, and the movable core is installed on a side surface side of the movable plate. Vessels are provided.

As described above, by installing the movable core on the side surface of the movable plate, it is possible to increase the degree of freedom of the installation position of the swinging means and realize a structure in which the leakage of magnetic flux is small.
Therefore, power consumption can be reduced and energy efficiency can be improved. Further, it becomes easy to obtain the generated force in the direction perpendicular to the support substrate, and it becomes easy to increase the swing stroke of the movable plate.

In one aspect of the present invention, the movable plate, the elastic support portion and the support substrate are formed of the same member. As described above, by forming the movable plate, the elastic support portion, and the support substrate from the same member, the assembly process is not necessary and the cost can be reduced. In addition, alignment between the movable plate and the supporting substrate is unnecessary, and variation between lots is reduced.

In one aspect of the present invention, the portion of the swinging means located apart from the movable plate includes a fixed core fixed to the support substrate and a coil wound around the fixed core. As described above, by using the fixed core around the coil for the swinging means, it is possible to control the operation of the movable plate by changing the current flowing through the coil.

In one aspect of the present invention, the movable core is installed on the side surface of the movable plate separated from the center of rotation. According to this, it becomes easier to obtain the generated force in the direction perpendicular to the support substrate, and it becomes easier to further increase the swing stroke of the movable plate.

In one aspect of the present invention, the movable core and the fixed core are arranged to face each other with a gap,
A plane parallel to the support substrate and bisecting the movable core in a direction perpendicular to the support substrate; and a plane parallel to the support substrate and fixed core in a direction perpendicular to the support substrate. The surface to be divided is different. In this way, the movable core and the fixed core are arranged to face each other with a gap,
Even when the elastic support portion is not deformed, the surface that bisects the movable core in the direction perpendicular to the support substrate is made different from the surface that bisects the fixed core in the direction perpendicular to the support substrate. The generated force can be obtained in the direction normal to the supporting substrate. Further, by appropriately determining the offset amounts of the center surfaces of the movable core and the fixed core with respect to the normal direction, it is possible to easily realize a large stroke and a large generated force.

In one aspect of the present invention, the fixed core has opposite end faces facing the movable core at both ends, and the two opposite end faces of the fixed core are in the same plane. According to this, the two facing end surfaces of the fixed core can be opposed to one surface of the movable core, the shape of the movable core can be simplified, and moreover, the leakage of magnetic flux can be reduced and the efficiency can be increased. It is possible to gain power. Further, the generated force is determined by the permeance of the air gap between the fixed core and the movable core, and since the longest side of the movable core can be configured as a magnetic path, a large generated force can be effectively obtained.

In one aspect of the present invention, the fixed core has opposite end faces facing the movable core at both ends, and the two opposite end faces of the fixed core are arranged so as to face each other. According to this, the two opposing end faces of the fixed core can be opposed to both end faces of the movable core, the shape of the movable core can be simplified, and further, the leakage of magnetic flux can be reduced and the generated force can be generated with high efficiency. It is possible to obtain In addition, a toroidal core can be formed by the movable core and the fixed core, and leakage of magnetic flux is extremely reduced. Therefore, current consumption can be reduced and energy efficiency is improved.

In one aspect of the present invention, the fixed core is arranged on either side of the rotation center of the movable plate, and forms a series magnetic circuit with the movable core. In this way, by arranging one fixed core on either side of one movable plate across the center of swing, and forming a series magnetic circuit with the movable core formed on the movable plate, it is necessary for driving. It is possible to reduce the inertia moment of the movable core, and to set the resonance frequency of the swing of the movable plate high. Further, since the area occupied by the coil and the fixed core can be reduced, the size of the entire device can be reduced.

In one aspect of the present invention, the fixed cores are arranged on both sides of the rotation center of the movable plate, and each of the movable cores arranged on both sides of the rotation center of the movable plate. And a series magnetic circuit are formed.
In this way, by disposing at least one fixed core (two or more in total) on both sides of the movable plate with the center of swinging therebetween, the fixed core formed on the movable plate corresponding to each fixed core. The movable plate can be effectively swung by forming a series magnetic circuit with the movable core and alternately driving the swinging means corresponding to each fixed core.

In one aspect of the present invention, each of the fixed core and the movable core has an uneven portion, and the uneven portion of the fixed core and the uneven portion of the movable core swing the movable plate. Are arranged so as to be meshed with each other through a gap. According to this, the force generated in the optical deflector does not decrease in inverse proportion to the square of the gap and is determined by a constant condition depending on the current passed through the coil. The control becomes extremely easy compared to the case. Moreover, since the maximum facing area between the fixed core and the movable core can be increased, the generated force can be increased.

In one aspect of the present invention, the optical deflector according to any one of claims 1 to 10, wherein at least one of the movable plate and the elastic supporting portion is made of single crystal silicon. According to this, since the damping coefficient of the elastic support portion becomes small, a large Q value can be obtained when used for resonance. Further, since fatigue fracture due to repeated deformation unlike a metal material does not occur, a long-life optical deflector can be constructed.

In one aspect of the present invention, the movable core is made of a ferromagnetic material. According to this, it is possible to provide an optical deflector with good controllability of the mover.

In one aspect of the present invention, the movable core is made of a hard magnetic material. This makes it possible to provide an optical deflector with good energy efficiency.

In one aspect of the present invention, the deflection unit has a mirror. According to this, it is possible to provide an optical deflector that is easy to manufacture and has a small movable portion.

In one aspect of the present invention, the deflection section has a lens. According to this, an optical deflector having a large deflection angle can be provided.

In one aspect of the present invention, the deflection section has a diffraction grating. According to this, it is possible to deflect the incident light into a plurality of beams.

In one aspect of the present invention, as the supporting substrate of the first optical deflector as described above, the second substrate as described above is used.
A movable plate other than the deflecting plate of the optical deflector is used, and the rotation center of the first optical deflector and the rotation center of the second optical deflector are orthogonal to each other. In this way, the incident light can be two-dimensionally deflected by making the actuator portion of the two optical deflectors a nesting structure.

According to the present invention, in order to solve the above-mentioned problems, a light source, an optical deflector as described above for deflecting the light emitted from the light source, and a light deflected by the optical deflector. And an image display surface onto which is projected.

As described above, by applying the above-mentioned optical deflector of the present invention to an image display device, a very small and inexpensive image display device can be provided.

According to the present invention, in order to solve the above problems, a light source, an optical deflector as described above for deflecting the light emitted from the light source, and a light deflected by the optical deflector. And an image forming surface onto which the image is projected.

As described above, by applying the above-mentioned optical deflector of the present invention to an image forming apparatus, it is possible to provide an extremely small and inexpensive image forming apparatus.

Further, according to the present invention, in order to solve the above-mentioned problems, there is provided a method of manufacturing an optical deflector as described above, which comprises a step of forming a groove in a substrate and the movable core in the groove. And a step of forming the movable substrate and the elastic supporting portion by using a part of the substrate to form the supporting substrate by using the other portion of the substrate. A method of manufacturing an optical deflector is provided.

As described above, by forming the groove in the substrate, forming the movable core in the groove, forming the movable plate from a part of the substrate, and forming the elastic supporting portion from a part of the substrate,
The movable core can be formed on the side surface side of the movable plate (on the inner surface such as a groove formed on the side surface or in the vicinity of the side surface).
Further, the movable plate and the elastic support portion can be manufactured at once. Further, it is not necessary to align the movable plate and the supporting substrate. Moreover, the assembly process is not required, and the cost can be easily reduced.

In one aspect of the present invention, the step of forming the supporting plate using the other part of the substrate by forming the movable plate and the elastic supporting part includes reactive ion etching. . According to this, the movable plate and the elastic support portion can be formed accurately and stably.

In one aspect of the present invention, the step of forming the support plate by using the other part of the substrate by forming the movable plate and the elastic support part includes etching using an alkaline solution. Done. According to this
By performing anisotropic etching based on the etching rate difference of the silicon crystal surface using the alkaline solution, the movable plate and the elastic support portion can be formed accurately and stably.
Further, since the etching rate is faster than that of reactive ion etching, the processing time can be shortened and the cost can be reduced.

In one aspect of the present invention, the step of forming the movable core is performed by plating. According to this, compared with vapor deposition or sputtering, it can be formed thicker and faster.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1] FIG. 1 is a diagram showing the configuration of a first embodiment of an optical deflector according to the present invention. In FIG. 1, (a) is a top view and (b) is A- in (a).
It is an A'sectional view. In FIG. 1, the stator 102 includes a fixed core 104 and a coil 105 that surrounds the fixed core 104, and is fixed on the support substrate 101. The stator 102 constitutes a part of the swing means (a part located apart from the movable plate). Both ends of the coil 105 are connected to bipolar terminals of the current source 108. Mover 103
Is composed of a movable plate 109, a movable core 106, and a deflector 111, and the torsion spring 107 allows the support substrate 101 to move.
It is swingably supported with respect to. Torsion spring part 10
Reference numeral 7 denotes an elastic supporting portion, which supports the movable plate 109 so as to be swingable around a rotation center (extending direction of the torsion spring portion 107: vertical direction in FIG. 1A). ing.
With the torsion spring portion 107 as the center of rotation, the movable plate 10
9, the movable core 106 and the deflection unit 111 integrally rotate (swing). Therefore, the torsion spring portion 107 can be referred to as the rotation center axis. When the torsion spring portion 107 has elasticity, the movable plate 109 and the movable core 1
When the 06 and the deflecting portion 111 are integrally rotated in one direction, the torsion spring portion 107 is likely to generate a reaction force in the rotation direction opposite to that direction, and therefore swinging (reciprocating motion) is facilitated. The movable core 106 constitutes a part of the swinging means. Specifically, the rocking means is composed of the movable core 106, the fixed core 104, and the coil 105, that is, the rocking means causes rocking regardless of whether or not the rocking means itself rocks. It is composed of the members of. The greatest feature is that the movable core 106 is installed on the side surface of the movable plate 109. The side surface of the movable plate 109 on which the movable core 106 is installed is at the farthest position separated from the rotation center (swing center) of the movable plate. The fixed core 104 has opposite end faces facing the side faces of the movable core 106 at both ends, and the two opposite end faces are in the same plane substantially parallel to the side faces of the movable core 106.

A surface 134 that bisects the fixed core 104 in the x-axis direction (a surface orthogonal to the x-axis direction) and the movable core 1
06 is different from the plane 136 that divides it in the x-axis direction (the plane orthogonal to the x-axis direction) 136 (that is, it is displaced in the x-axis direction), and an appropriate overlap length x ₀ is set. There is. The deflection unit 111 is composed of optical elements such as mirrors, lenses, and diffraction gratings. The movable core 106 is the movable plate 1
It is characterized in that it is installed on a surface substantially vertical to the support substrate 101 of No. 09. The support substrate 101, the torsion spring portion 107, and the mover 103 are integrally formed by a semiconductor process. The coil 105 is made of a low resistance metal such as copper or aluminum, and is electrically insulated from the fixed core 104. Also, fixed core 1
04 and the movable core 106 are ferromagnetic nickel.
It is made of iron, cobalt, or an alloy thereof, or a hard magnetic material such as samarium cobalt or neodymium iron boron. Further, the fixed core 104 and the coil 105 are electrically insulated from each other by interposing an insulating film made of polyimide, benzocyclobutene or the like between them or forming an aerial wiring.

When a current is supplied from the current source 108 in the direction of the arrow, magnetic flux is generated in the coil 105 in the direction of the arrow. The magnetic flux circulates around the magnetic circuit in the order of the fixed core 104, the air gap, the movable core 106, and the air gap in the direction indicated by the arrow, and moves the movable core 106 in the direction in which the air gap becomes narrow, that is, in the normal direction of the support substrate 101. It is pulled toward the fixed core 104. As a result, the mover 103 swings around the torsion spring portion 107.

Here, as shown in FIG.
The air gap distance is δ, and the movable core 1 of the fixed core 104 is
If the width of the end face opposed to 06 is x, the overlap length in the initial state is x ₀ , the displacement of the movable core 106 is x, and the magnetic permeability of the vacuum is μ ₀ , the gap between the movable core 106 and the fixed core 104 is The permeance P _g of the air gap is given by the following equation (1): P _g = μ ₀ w (x + x ₀ ) / (2δ) ... (1).

Air gap forming the magnetic circuit
If the permeance other than is P, the number of turns of the coil 105 is N, and the current flowing through the coil 105 is i, the potential energy W of the entire magnetic circuit is expressed by the following equation (2): W = (-1/2) [( 1 / P) + (1 / P _g )] ⁻¹ (Ni) ² ... (2)

When the movable core 106 and the fixed core 104 are made of a magnetic material having a sufficiently large relative permeability, P can be regarded as almost infinite as compared with P _g . Therefore, the generated force F generated in the void is given by the following formula (3): F =-(dW / dx) =-μ ₀ w (Ni) ² / (2δ) ... (3). From this, it is understood that in the optical deflector of the present invention, the generated force F is proportional to the square of the number of turns N of the coil 105 and the square of the current i.

As shown in FIG. 1, since the movable core 106 is arranged at a position where a rotational force can be generated around the torsion spring 107 in the movable element 103, the generated force F causes the movable element 103 to swing. Move.

On the other hand, when the mover 103 swings, the torsion spring portion 107 is twisted, and the spring reaction force F ′ of the torsion spring portion 107 and the mover 103 generated thereby are twisted.
As shown in FIG. 1A, the distance from the center (rotation center) of the torsion spring portion 107 to the force point is L, and the length of each torsion spring portion 107 is L. ₀ ,
_Let G be the transverse elastic modulus and I _p be the second polar moment of area,
The following equation (4): φ = (F ′ · L·L ₀ ) / (2G · I _p ) ... (4)

Then, the movable element 103 swings to a position where the generated force F and the spring reaction force F'balance each other. Therefore, by substituting F ′ in equation (3) into F ′ in equation (4), the mover 10
It can be seen that the displacement angle φ of 3 is proportional to the square of the current i flowing in the coil 105. Therefore, the displacement angle φ of the mover 103 can be controlled by controlling the current flowing through the coil 105.

Next, an embodiment of a method of manufacturing the above optical deflector will be described with reference to FIG. In FIG. 2, (a) to (h) are the same as in FIG.
It is a figure which shows the cross section corresponding to (b). However, in order to make the manufacturing process easier to understand, the dimensions, particularly the dimensions in the vertical direction, are enlarged and exaggerated.

First, as shown in FIG. 2 (a),
Using a thermal oxidation furnace or the like, a silicon dioxide (mask) 110 having a thickness of 1 μm is formed on a substrate 101 ′ whose material is single crystal silicon.
A film is formed to a degree, and patterning is performed using wet etching with hydrofluoric acid or the like or reactive ion etching with a fluorine-based gas. Using the patterned silicon dioxide (mask) 110 as an etching mask, the substrate 101 is etched to a depth of about 100 μm using inductively coupled plasma reactive ion etching to form the groove 10.
1 ″ is formed.

Next, as shown in FIG.
After removing the silicon dioxide (mask) 110 used as the etching mask by wet etching with hydrofluoric acid or the like or reactive ion etching, the silicon dioxide (insulating layer) is formed by a thermal oxidation furnace, sputtering, CVD, or the like.
A film (not shown) is formed. As a seed electrode (lower) 123 for electroplating thereon, titanium is deposited to a thickness of about 50 Å, and then gold or copper is deposited to a thickness of about 1000 Å by vapor deposition, sputtering or the like. 25 photo resist (bottom) 115 on it
After forming a film having a thickness of about μm, patterning is performed to form a plating mask.

Next, as shown in FIG. 2 (c),
20μm copper by electroplating or electroless copper plating
The lower wiring 120 is formed by forming a film. The photoresist (bottom) 115 and the seed electrode (bottom) 123 (however, only the exposed portion) are removed by reactive ion etching or ion milling. An insulating film (bottom) (not shown) such as polyimide or benzocyclobutene is formed thereon,
A contact hole (bottom) is formed by patterning using wet etching with a strong alkaline solution such as tetramethylammonium hydroxide aqueous solution or reactive ion etching.

Next, as shown in FIG.
As a seed electrode (middle) 124 for electroplating, after depositing titanium or chromium or the like to a thickness of about 50Å, gold or copper, Fe-Ni
An alloy or the like is formed into a film by vapor deposition, sputtering, or the like. A photoresist (medium) 116 is formed thereon with a thickness of about 55 μm, and then patterned. Here, as the photoresist (medium) 116, a photoresist suitable for a thick film, for example, S
U-8 (manufactured by MICROCHEM CORP.) Can be used.

Next, as shown in FIG.
Using the photoresist (medium) 116 as a mask for electroplating, electroplating is performed, and iron, nickel, which are ferromagnetic materials,
The fixed core 104 and the movable core 106 are formed by depositing cobalt or an alloy thereof with a thickness of about 50 μm. Next, the photoresist (medium) 116 is removed using heated N-methylpyrrolidone. Next, seed electrode (middle)
124 (however, only the exposed portion) is removed by reactive ion etching or ion milling.

Next, as shown in FIG.
An insulating film (upper) (not shown) such as polyimide or benzocyclobutene is formed and patterned to form a contact hole (upper). The contact hole (top) is
It is formed at a position corresponding to the contact hole (lower). Next, as a seed electrode (upper) 125 for electroplating, titanium is deposited to a thickness of about 50 Å, and then gold is deposited to a thickness of about 1000 Å by vapor deposition or the like. A photoresist (upper) 117 is formed thereon with a thickness of about 25 μm, and then patterned. Here, a photoresist suitable for the film thickness, for example, AZ P4620 (manufactured by Hoechst) can be used as the photoresist (upper) 117. Copper plating is performed using the photoresist 117 (upper) as a mask to form a copper film having a thickness of about 20 μm.
The upper wiring 122 is formed. As a result, the upper wiring 122 and the lower wiring 120 are connected through the contact hole (upper) and the contact hole (lower), and the coil 105 is formed.

Next, as shown in FIG.
Photoresist (top) 117 and seed electrode (top) 12
5 (however, only the exposed part) is removed. Next, after forming silicon dioxide on the back surface by sputtering or the like, patterning is performed to form an etching mask (not shown). Next, anisotropic etching is performed on the back surface using a heated potassium hydroxide aqueous solution to expose the movable core 106 (which may be provided with the seed electrode (middle) 124), so that the movable core 106 has a desired thickness. The plate 109 is formed.

Next, as shown in FIG.
After forming silicon dioxide on the surface by sputtering or the like, patterning is performed to form an etching mask. Next, the substrate 101 ′ is subjected to inductively coupled plasma reactive ion etching.
Etching is performed until it penetrates to form the mover 103 and the torsion spring portion (not shown). Finally, the deflection unit 111
Is installed on the mover 103.

Although the movable core 106 is formed on the side surface of the movable plate 109 in the above description, in the present embodiment, the movable core 106 is formed on the side surface side of the movable plate 109. It can be formed close to the side surface rather than on the side surface. For example, when performing etching through the substrate 101 ′ in the step of FIG. 2H, the side surface of the movable core 106 facing the fixed core 104 is not exposed, that is, also on the side surface of the movable core 106. By patterning so that the movable plate 109 exists,
The movable core 106 can be installed at a position closer to the torsion spring portion than the side surface of the movable plate 109 (however, close to the side surface). The movable core 106 is not necessarily the movable plate 109.
The groove 101 "of the movable plate 109
The bottom part of the groove may be left in an appropriate thickness so as to be located in the groove 101 ″. Such a groove may be formed on the lower surface side of the movable plate 109.

[Second Embodiment] FIG. 3 is a diagram showing a second embodiment of the optical deflector according to the present invention. In FIG. 3, (a)
Is a top view, and (b) is a BB 'sectional view in (a). The basic configuration, driving method, and manufacturing method in this embodiment are the same as those in the first embodiment. In FIG. 3, the stator 202 includes a fixed core 204 and a fixed core 204.
And a coil 205 that goes around the support substrate 20.
It is fixed on 1. Both ends of the coil 205 are the current source 2
08 are connected to both pole terminals. The mover 203 is composed of a movable plate 209, a movable core 206, and a deflecting portion 211, and is supported by a torsion spring portion 207 so as to be freely swingable with respect to the support substrate 201. The fixed core 204 and the movable core 206 have a comb tooth shape, and the movable core 206 is installed on the side surface of the movable plate 209.
However, in FIG. 3, for simplicity, the number of comb teeth is reduced. The dimensions of the comb teeth of the stator 202 and the mover 203 are, for example, a comb tooth length of 200 μm, a comb tooth width of 25 μm, and a gap between comb teeth of 25 μm. Stator 2
The arrangement pitch of the comb teeth in each of 02 and the mover 203 is, for example, 100 μm. The sizes S ₁ and S ₂ of the portion of the stator 202 excluding the comb teeth are, for example, S ₁ = 8 mm and S ₂ = 10 mm.

The optical deflector of the present embodiment configured as described above is arranged so that the concave and convex portions of the fixed core 204 formed by the comb teeth and the concave and convex portions of the movable core 206 formed by the comb teeth mesh with each other through a gap. Since the fixed core 204 and the movable core 206 do not mechanically interfere with each other, the swing stroke can be increased. Further, since the movable core 206 is installed on the side surface of the movable plate 209, it is possible to make a large deviation in the thickness direction of the formation surface of the fixed core 204 and the movable core 206, and to make the deformation angle of the mover 203 large. easy. Further, the maximum facing area can be increased between the fixed core 204 and the movable core 206, a structure with less leakage of magnetic flux can be realized, and energy efficiency is good.

[Third Embodiment] FIG. 4 is a top view showing a third embodiment of the optical deflector of the present invention. The basic configuration, driving method, and manufacturing method in this embodiment are the same as those in the first embodiment. The third embodiment has a configuration in which a stator 302 and a current source 308 are arranged on both sides of one movable element 303 on a support substrate 301. Each of the stators 302 corresponds to the stator 1 of the first embodiment.
It has the same structure as 02. That is, in FIG.
The stator 302 includes a fixed core 304 and a coil 305 that surrounds the fixed core 304, and is fixed on the substrate 301. Both ends of the coil 305 are connected to the bipolar terminals of the current source 308. The mover 303 is a movable plate 30.
9, a movable core 306, and a deflection portion 311 and is supported by a torsion spring portion 307 so as to freely swing with respect to the support substrate 301. The movable core 306 is a movable plate 309.
On both sides (both sides of the center of rotation of the movable plate) so as to face the fixed core 304, respectively. Movable core 30
6 is installed parallel to the torsion spring portion 307 on the side surface of the movable plate 309. Each current source 308
Can independently supply current to the corresponding coil 305. The driving method is such that a current source 308 is used to alternately pass a current through the two coils 305, and
Rock continuously. Further, by using a displacement sensor (not shown), the displacement of the mover 303 is detected, the current flowing from the current source 308 is changed, and the movement of the mover 303 is controlled (the timing at which the current flows from each current source 308). (Including suppressing the movement of the mover 303) is also possible.

In the optical deflector of this embodiment configured as described above, since the two movable cores 306 are installed on the side surfaces of the movable plate 309, the weight balance of the movable plate 309 in the vertical direction and the horizontal direction is balanced. Good, movable plate 3 when not driven
The inclination of 09 with respect to the support substrate 301 can be easily eliminated. In addition, the two fixed cores 304 are movable elements 303.
Since they are installed on both sides of the movable core 306, regardless of the displacement of the movable element 309 during driving (that is, regardless of the phase of the swing of the movable element 303), any one of the fixed cores 304 to the corresponding movable core 306 can be used. An electromagnetic force can be applied to the motor, which enables extremely stable driving.

[Fourth Embodiment] FIG. 5 is a top view showing a fourth embodiment of the optical deflector of the present invention. In this embodiment,
The optical deflector according to the first embodiment is formed in two stages.
Dimensional deflection is possible (ie swinging about centers of rotation in different directions). That is, in this embodiment, two optical deflectors (large) 421 and an optical deflector (small) 42 are provided.
Have two.

In the optical deflector (large) 421, the stator 4
Reference numeral 02a includes a fixed core 404a and a coil 405a that surrounds the fixed core 404a, and is fixed on the support substrate 401. Both ends of the coil 405a have a current source 40.
8a is connected to both terminals. The mover 403a is
The movable plate 409a, the movable core 406a, and the deflection unit 411 are included, and the substrate 40 is formed by the torsion spring unit 407a.
1 is supported so as to be swingable around a first direction (vertical direction in the drawing). Movable core 406
a is arranged on the side surface of the movable plate 409a so as to face the fixed core 404a. The movable core 406a is installed on the side surface of the movable plate 409a in parallel with the torsion spring portion 407a.

The optical deflector (small) 422 is an optical deflector (large).
It is formed by using the mover 403a of 421 as a support substrate (however, the deflecting portion of the optical deflector (large) 421 is excluded). That is, in the optical deflector (small) 422,
The stator 402b includes a fixed core 404b and a fixed core 404.
It is composed of a coil 405b that goes around b and is fixed on the movable plate 409a of the optical deflector (large) 421. Both ends of the coil 405b are connected to the bipolar terminals of the current source 408b. The mover 403b is configured to include a movable plate 409b, a movable core 406b, and a deflection unit 411, and a torsion spring portion 407b causes the movable plate 409a to move in a second direction (left-right direction in the drawing) orthogonal to the first direction. ) Is supported so that it can swing around. The movable core 406b is fixed to the side surface of the movable plate 409b by the fixed core 404b.
It is arranged so as to face with. The movable core 406b is installed on the side surface of the movable plate 409b in parallel with the torsion spring portion 407b.

As described above, the optical deflector (small) 422 has a nested structure arranged on the mover 403a of the optical deflector (large) 421. The current sources 408a and 408b are
Each is an optical deflector (large) 421 and an optical deflector (small) 42.
2 can be driven independently. Therefore, the light emitted from a light source such as a semiconductor laser (not shown) is applied to the light deflector 411 including a mirror and the reflected light is two-dimensionally deflected around the first direction and around the second direction. be able to.

Further, as the optical deflector (large) 421 and the optical deflector (small) 422, the optical deflectors of the above-described second and third embodiments can be used. Optical deflector (large) 421
Alternatively, one of the optical deflectors (small) 422 and the other may be used by combining different optical deflectors of the first to third embodiments. Further, an optical element such as a lens or a diffraction grating may be installed as the light deflector 411.

The optical deflector of the present embodiment configured as described above is a two-dimensional optical deflector with high energy efficiency and capable of extremely stable driving.

[Fifth Embodiment] FIG. 6 is a top view showing a fifth embodiment of the optical deflector of the present invention. In this embodiment, the shape of the fixed core 104 is different from that of the first embodiment. That is,
The fixed core 104 has opposite end faces facing both end faces of the movable core 106 at both ends, and the two opposite end faces are arranged so as to face each other. Fixed core 10
The air gap between the movable core 1 and the movable core 106 is
Is formed at both ends of the movable core 106.
The stationary core 104 and the fixed core 104 form a toroidal core.

[Sixth Embodiment] FIG. 7 is a schematic diagram showing the basic structure of an image display apparatus according to the present invention, which is an optical apparatus using the optical deflector according to the present invention. In FIG. 7, 502 is a laser light source, 503 is a lens or a lens group,
Reference numeral 504 is a writing lens or a lens group, and 505 is a projection surface (image display surface). An optical deflector group 501 is arranged between two lenses or lens groups 503 and 504. The optical deflector group 501 includes two optical deflectors 501a and 501b, and is provided with a lens or a lens group from the laser light source 502.
The light arriving via 503 is subjected to a deflection action around the first direction by the optical deflector 501a, and the light deflected by the optical deflector 501a is deflected by the optical deflector 501b in the second direction orthogonal to the first direction. The light is projected on the projection surface 505 through the writing lens or the lens group 504 by being deflected by the surroundings. As the optical deflectors 501a and 501b, the optical deflectors of the above-described first to third embodiments can be used, and an optical element such as a mirror, a lens, or a diffraction grating can be used as the deflecting unit.

As described above, the image display apparatus of this embodiment uses the optical deflector group 501 in which two optical deflectors are arranged so that the deflection directions are orthogonal to each other, and the light is deflected in the horizontal and vertical directions. It functions as an optical scanner device for raster scanning.
The laser light from the laser light source 502 is subjected to a predetermined intensity modulation related to the timing of optical scanning, and is two-dimensionally scanned by the optical deflector group 501, so that the projection surface 505
Form the image above.

In this embodiment, the light deflector group 501 may be the light deflector of the fourth embodiment. Even in that case, similar image display can be performed.

[Seventh Embodiment] FIG. 8 is a schematic view showing the basic structure of an image forming apparatus according to the present invention, which is an optical apparatus using the optical deflector according to the present invention. In FIG. 8, 602 is a laser light source, 603 is a lens or a lens group,
Reference numeral 604 is a writing lens or a lens group, and 606 is a drum-shaped photoconductor (image forming surface). An optical deflector 601 is arranged between the two lenses or lens groups 603 and 604. As the optical deflector 601, the above-described first to third embodiments are used.
Optical deflectors 3 and 5 can be used, and an optical element such as a mirror, a lens, or a diffraction grating can be used as the deflecting unit.

As described above, the image forming apparatus of this embodiment functions as an optical scanner device that scans light in a one-dimensional direction parallel to the rotation center C of the drum-shaped photosensitive member 606 by the optical deflector. The laser light from the laser light source 602 is subjected to predetermined intensity modulation related to the timing of optical scanning, and is one-dimensionally scanned by the optical deflector 601. on the other hand,
The drum-shaped photosensitive member 606 rotates around the rotation center C at a required rotation speed. The surface of the photoconductor 606 is uniformly charged by a charger (not shown). Therefore, based on the scanning by the light deflector 601 and the rotation of the photoconductor 606, light is incident on the surface of the photoconductor 606 in a pattern, and the electrostatic latent area is formed between the light incident portion and the light non-incident portion. An image is formed. A developing device (not shown) forms a toner image having a pattern corresponding to the electrostatic latent image on the surface of the photoconductor 606, and the visible image can be formed by transferring and fixing the toner image on, for example, a sheet (not shown). .

[0073]

As described above, according to the optical deflector of the present invention, a large swing stroke can be realized and a large angle change of the movable plate is possible as compared with the conventional optical deflector. is there. In addition, it can be miniaturized and can operate at high speed. In addition, the leakage of magnetic flux is small and the energy efficiency is high. Further, cost reduction can be achieved.

Further, according to the image display apparatus and the image forming apparatus of the present invention, downsizing and cost reduction can be achieved.

Further, according to the method of manufacturing the optical deflector of the present invention, the movable plate, the elastic supporting portion and the supporting substrate can be formed at the same time, and the assembling steps thereof are unnecessary and the cost can be reduced. is there.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of an optical deflector of the present invention.

FIG. 2 is an explanatory diagram of an embodiment of a method for manufacturing an optical deflector of the present invention.

FIG. 3 is an explanatory diagram of an embodiment of an optical deflector of the present invention.

FIG. 4 is an explanatory diagram of an embodiment of an optical deflector of the present invention.

FIG. 5 is an explanatory diagram of an embodiment of an optical deflector of the present invention.

FIG. 6 is an explanatory diagram of an embodiment of an optical deflector of the present invention.

FIG. 7 is an explanatory diagram of an embodiment of the image display device of the present invention.

FIG. 8 is an explanatory diagram of an embodiment of the image forming apparatus of the present invention.

FIG. 9 is an explanatory diagram of a conventional optical deflector.

FIG. 10 is an explanatory diagram of a conventional optical deflector.

[Explanation of symbols]

101, 201, 301, 401: supporting substrate 101 ': substrate 101 ": grooves 102, 202, 302, 402a, 402b: stators 103, 203, 303, 403a, 403b: movers 104, 204, 304, 404a, 404b: Fixed core 105, 205, 305, 405a, 405b: Coil 106, 206, 306, 406a, 406b: Movable core 107, 207, 307, 407a, 407b: Torsion spring portion 108, 208, 308, 408a, 408b: Current sources 109, 209, 309, 409a, 409b :: Movable plate 110: Silicon dioxide (mask) 111, 211, 311, 411: Light deflector 115: Photoresist (bottom) 116: Photoresist (center) 117: Photo Resist (upper) 120: Lower wiring 123: Seed electrode (Lower) 124: Seed electrode (middle) 125: Seed electrode (upper) 134, 136: Surface 421: Optical deflector (large) 422: Optical deflector (small) 501: Optical deflector group 501a, 501b: Optical deflection Device 502, 602: Laser light source 503, 603: Lens or lens group 504, 604: Writing lens or lens group 505: Projection surface 601: Optical deflector 606: Drum-shaped photoconductor

Continued front page    (72) Inventor Takayuki Teshima             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 2C362 BA17 BA18 BA83 BA84                 2H042 DA05 DA07 DA12 DA18 DB08                       DC02 DC08 DE07                 2H045 AB06 AB10 AB13 AB16 AB22                       AB73                 2H049 AA07 AA13 AA44 AA60 AA69

Claims (23)

[Claims] 1. A movable plate having a deflecting part for deflecting incident light, an elastic support part for supporting the movable plate so as to be swingable around a rotation center, and a support for supporting the elastic support part. In an optical deflector including a substrate and a swinging unit that swings the movable plate and has a portion spaced apart from the movable plate, the swinging unit includes a movable core attached to the movable plate. An optical deflector having the movable core, the movable core being installed on a side surface of the movable plate. 2. The optical deflector according to claim 1, wherein the movable plate, the elastic support portion, and the support substrate are formed of the same member. 3. A portion of the swinging means, which is located away from the movable plate, includes a fixed core fixed to the support substrate and a coil wound around the fixed core. The optical deflector according to any one of 1 to 2. 4. The optical deflector according to claim 1, wherein the movable core is installed on the side surface of the movable plate separated from the rotation center. 5. A surface in which the movable core and the fixed core are arranged to face each other with a gap interposed therebetween, and the surface is parallel to the support substrate and bisects the movable core in a direction perpendicular to the support substrate. And a plane that is parallel to the support substrate and bisects the fixed core in a direction perpendicular to the support substrate is different from each other. vessel. 6. The fixed core has opposite end faces facing the movable core at both ends, and two opposite end faces of the fixed core are in the same plane.
The optical deflector according to claim 3. 7. The fixed core has opposite end faces facing the movable core at both ends, and two opposite end faces of the fixed core are arranged so as to face each other. Item 6. The optical deflector according to any one of items 3 to 5. 8. The fixed core is arranged on either side of the rotation center of the movable plate and forms a series magnetic circuit with the movable core. The optical deflector according to any one of 1. 9. The fixed cores are arranged on both sides of the rotation center of the movable plate, and each forms a series magnetic circuit with each of the movable cores arranged on both sides of the rotation center of the movable plate. The method according to claim 3, wherein
7. The optical deflector according to any one of 7. 10. The fixed core and the movable core each have a concavo-convex portion, and the concavo-convex portion of the fixed core and the concavo-convex portion of the movable core allow rocking of the movable plate. The optical deflector according to any one of claims 3 to 9, wherein the optical deflectors are arranged so as to mesh with each other via a gap. 11. The optical deflector according to claim 1, wherein at least one of the movable plate and the elastic support portion is made of single crystal silicon. 12. The optical deflector according to claim 1, wherein the movable core is made of a ferromagnetic material. 13. The optical deflector according to claim 1, wherein the movable core is made of a hard magnetic material. 14. The optical deflector according to claim 1, wherein the deflection unit has a mirror. 15. The optical deflector according to claim 1, wherein the deflection unit has a lens. 16. The optical deflector according to claim 1, wherein the deflection section has a diffraction grating. 17. The support substrate of the first optical deflector according to claim 1, wherein the support substrate is the support substrate.
A movable plate other than the deflecting plate of the second optical deflector is used, wherein the rotation center of the first optical deflector and the rotation center of the second optical deflector are used. An optical deflector characterized in that and are orthogonal to each other. 18. A light source, and the optical deflector according to claim 1, which deflects light emitted from the light source.
An image display device having an image display surface on which the light deflected by the light deflector is projected. 19. A light source, and the optical deflector according to claim 1, which deflects light emitted from the light source.
And an image forming surface onto which the light deflected by the light deflector is projected. 20. A method of manufacturing an optical deflector according to claim 1, wherein a step of forming a groove in a substrate, a step of forming the movable core in the groove, A step of forming the movable plate and the elastic supporting part by using a part of the substrate to form the supporting substrate by using the other part of the substrate. . 21. The step of forming the supporting substrate by using the other portion of the substrate by forming the movable plate and the elastic supporting portion includes reactive ion etching. A method for manufacturing an optical deflector according to claim 20. 22. The step of forming the supporting substrate using the other portion of the substrate by forming the movable plate and the elastic supporting portion includes etching using an alkaline solution. The method for manufacturing an optical deflector according to any one of claims 20 to 21. 23. The method of manufacturing an optical deflector according to claim 20, wherein the step of forming the movable core is performed by plating.