JP2002048998A - Optical scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve manufacturing efficiency by realizing small modularization of an optical scanner and to simplify a manufacturing process. SOLUTION: In an optical scanner module which deflects and scans luminous flux from a semiconductor laser, the board of a light source part for mounting the semiconductor laser and the board of a deflection part for holding a deflection means having a deflection surface to deflect the luminous flux are stacked, a reflecting surface is provided oppositely to the deflection surface, and the luminous flux is reflected more than once between the reflecting surface and the deflection surface to scan.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device which is used in a writing system such as a digital copying machine and a laser printer and has a micro optical system to which a micro machining technology is applied.

[0002]

2. Description of the Related Art In the prior art, an optical scanning device is composed of a light source unit in which the arrangement of a packaged semiconductor laser and a coupling lens is adjusted and assembled, a deflector such as a polygon mirror or a galvanometer mirror by precision machining, a plurality of optical scanning devices. The lens is assembled while maintaining the positional relationship with high precision at a predetermined mounting portion of the optical housing.However, since it depends on manual work, there is a limit to miniaturization. There is a disadvantage in that it takes a lot of cost to attach.

A configuration example of a conventional optical scanning device will be described with reference to FIGS. 1 and 2. FIG. First, FIG. 1 shows an example using a polygon mirror. In the figure, a semiconductor laser (L
D) 101 is press-fitted into a fitting hole formed on the back side of the holding member 102, and the coupling lens 103 is UV-bonded to a projection formed by cutting out a part of a cylindrical surface formed at a through-hole exit portion of the holding member. . The LD drive substrate 106 has L
A circuit for starting modulation of D is mounted, and a lead of the LD is soldered to the circuit to form a light source unit. A substantially parallel light beam is emitted from the light source unit by adjusting the arrangement of the coupling lens. The cylinder lens 104 has a curvature only in the sub-scanning direction, and converges on the reflection surface of the polygon mirror 107 so as to be linear in the main scanning direction, and constitutes a part of a surface tilt correction optical system. The polygon mirror 107 is rotated in a certain direction by a motor 108 and scans a beam. The scanned beam is formed as an image of a spot on the surface to be scanned 114 (photosensitive member surface) via the mirror 111 by the imaging lens 110. The mirror 113 folds the beam on the scanning start side, makes the beam incident on the photo sensor 108 mounted on the sensor substrate 109, and sets the image recording timing based on the detection time.

The light source unit, the motor, the imaging lens, the mirror, and the sensor substrate are positioned with high precision on the optical base 112 and are integrally supported.

FIG. 2 shows an example using a galvanomirror 115. The configuration is the same as that of FIG. 1 except that a galvanomirror is used. 1, the polygon mirror scans the beam in a fixed direction, while the galvanometer mirror 115 in FIG. 2 reciprocates in the direction of the arrow to scan the beam in both directions.

In recent years, research on an optical scanning device using silicon micromachining technology has been advanced for the above-mentioned configuration. Japanese Patent No. 2722630 and Japanese Patent No. 266
As disclosed in Japanese Patent No. 8725 and JP-A-4-96014, there has been proposed an optical scanning device in which a semiconductor laser chip and a deflector integrated with a bearing are integrated on a single silicon substrate.

Since a semiconductor manufacturing process is used, there is an advantage that extremely high positional accuracy can be ensured, and a plurality of semiconductor devices can be manufactured simultaneously without manual operation.

On the other hand, as a deflector using a semiconductor manufacturing process, Japanese Patent No. 2722314 discloses a deflector in which a galvanometer mirror is integrally formed on a silicon substrate, and JP-A-5-142405 discloses a diffraction grating on the surface. A formed deflector is disclosed.

Incidentally, as a mechanism for swinging the mirror, in addition to a mechanism using electromagnetic force as shown in the above-mentioned Japanese Patent No. 2722314, an optical scanning device disclosed in IBM J. Res. Develop Vol. 24 (1980) can be used. Then, the mirror substrate supported by two beams provided on the same straight line is reciprocated using the two beams as a torsion rotation axis by an electrostatic attraction between an electrode provided at a position facing the mirror substrate. Some cause it to vibrate. This optical scanning device formed by micromachining technology,
Compared to a conventional optical scanning device that rotates a polygon mirror using a motor, its structure is simpler and it can be formed in a single process in a semiconductor process, so it is easy to reduce the size and manufacturing cost. Therefore, there is no variation in accuracy due to a plurality of surfaces, and furthermore, the effect of being able to cope with high-speed operation due to reciprocal scanning can be expected.

Japanese Patent No. 2924200 discloses such an electrostatically driven torsional vibration optical scanning device.
Japanese Unexamined Patent Publication No. 7-92409, in which the beam is made S-shaped to reduce rigidity so that a large deflection angle can be obtained with a small driving force.
Disclosed in Japanese Patent No. 3011144, in which the thickness of the beam is made thinner than the mirror substrate and the frame substrate.
The 13th Annual International Workshop on MEMS200
0 (2000) 473-478, in which the fixed electrode is arranged at a position that does not overlap in the vibration direction of the mirror section,
e 13th Annual International Workshop on MEMS2000
As described in (2000) 645-650, there is a device in which the driving voltage is lowered without changing the deflection angle of the mirror by installing the counter electrode inclined from the center position of the deflection of the mirror.

[0011]

In an optical scanning device using a silicon micromachining technology, there is a limitation in a manufacturing process for forming all functions related to optical scanning on a single silicon substrate. Simply arranging one-dimensionally with the same layout as the conventional one is wasteful in terms of substrate size.

Further, there is a disadvantage in that the efficiency of the function requiring a certain thickness is very low due to the repetition of trimming by thin film formation and etching.

On the other hand, semiconductor lasers and deflectors require external power supply and exchange of control signals, respectively. However, the miniaturization of the optical scanning device makes handling of electrical wiring rather troublesome. There is.

In addition, it is naturally necessary to take measures against dust and dust which cause deterioration of optical performance and short-circuit, so that the silicon substrate cannot be incorporated in an image forming apparatus or the like.

As described above, there are a number of problems in reducing the size of an optical scanning device used in an image forming apparatus.

In a deflector that holds the mirror substrate on both sides with two beams and reciprocates the mirror substrate by electrostatic attraction using the beams as a torsional rotation axis, the mirror substrate is used as one common electrode and the torsional rotation is performed. The other two electrodes for driving on both sides of the shaft are opposed to the plane side of the mirror substrate and to the end surface side of the mirror substrate.

Generally, when the applied voltage is constant, the electrostatic attractive force is inversely proportional to the square of the distance between the electrodes, and is proportional to the electrode area. Therefore, when the electrodes are provided to face the plane of the mirror substrate opposite to the mirror surface, the electrostatic attraction can be increased by increasing the electrode area. However, if the distance between the electrodes is shortened to obtain a larger electrostatic attraction, the electrodes are close to the direction of vibration of the mirror substrate, which hinders displacement, and the deflection angle of the mirror portion is limited to a range where the electrodes do not contact the electrodes. I will. On the other hand, when the electrodes are provided on the end face side of the mirror substrate, the electrostatic attraction can be increased by shortening the distance between the electrodes. In this case, since the electrodes are located at positions where they do not contact each other, the displacement of the mirror substrate is not hindered.
Since it is only about 0 μm, the electrode area cannot be made large. Even if opposing electrodes are bent into a comb shape, the area of the substrate vibrating at a high frequency is limited due to the strength of the substrate. As described above, it is difficult for an electrostatically driven torsional vibrating mirror to have both a large electrostatic attraction, that is, a large large-area driving electrode and a large deflection angle of a mirror substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to improve the above-mentioned drawbacks in an optical scanning device using silicon micromachining technology, to realize a small module as an optical scanning device, and to realize a manufacturing process. The purpose is to improve production efficiency by simplifying. In addition, the power consumption can be reduced by reducing the size and weight of the movable part of the deflector and reducing the load. It is a further object of the present invention to provide an optical scanning device having an electrostatically driven torsional vibration type deflector capable of obtaining a stable vibration with a large deflection angle.

[0019]

According to a first aspect of the present invention, there is provided an optical scanning device module for scanning by deflecting a light beam from a light source, a deflecting device having a deflecting surface for deflecting the light beam, and rotating the deflecting device. A deflecting unit substrate that is supported by being supported and provided, a reflecting surface is provided integrally with the deflecting unit substrate so as to face the deflecting surface, and the light beam is reflected a plurality of times between the reflecting surface and the deflecting surface. And scan.

According to a second aspect of the present invention, there is provided an optical scanning device module for deflecting and scanning a light beam from a light source.
A light source unit substrate on which a light source is mounted and a deflecting unit substrate holding a deflecting unit having a deflecting surface for deflecting a light beam are stacked and provided, and a reflecting surface is provided opposite to the deflecting surface, and the reflecting surface and the deflecting surface are deflected. Scanning is performed by reflecting a light beam a plurality of times with the surface.

According to the above invention, a larger scanning angle can be obtained with a small rotation angle of the deflector, and the speed of the deflector can be reduced. Therefore, the movable portion can be thinned, the processing time can be shortened, and the assembling efficiency can be improved. be able to. Further, by stacking and arranging the light source unit substrates, the light beam can be accurately incident on the deflection surface. In addition, noise and vibration can be reduced.

The invention described in claim 3 is the first or second invention.
In the description, the distance between the reflecting surface and the deflecting surface
g, when the incident angle of the light beam in the sub-scanning direction on the deflection surface is β, and the diameter of the incident light beam in the sub-scanning direction is 2ω, the relationship represented by g · tan β> ω is satisfied, and The scanning is performed by sequentially moving the reflection points in the sub-scanning direction.

According to the present invention, the required width in the main scanning direction can be minimized, so that the movable portion can be reduced in size.
Processing time is shortened, and assembling efficiency can be improved.

[0024] The invention described in claim 4 is the first to third aspects of the present invention.
In the description of any one of the above, the interval between the reflecting surface and the deflecting surface is wider on the exit side than on the incident side of the light beam.

According to the present invention, since the angle of the light beam in the sub-scanning direction on the emission side can be enlarged and the margin with the edge of the reflection surface can be widened, the light beam can be reliably emitted even if there is an error in the incident angle. In addition, the installation accuracy of the reflection surface can be reduced, and the assembly efficiency can be improved.

The invention according to claim 5 is the invention according to claims 1 to 4
In any one of the above, the light source unit substrate on which the light source is mounted is stacked and provided on the deflection unit substrate, and the reflection surface is provided on the light source unit substrate.

[0027] The invention according to claim 6 is the invention according to claims 1 to 4.
In the description of any one of the above, the reflection surface is provided integrally with the light source unit substrate.

According to the above-mentioned invention, since the arrangement accuracy of the reflecting surface and the deflecting surface can be ensured by lamination without performing a troublesome adjustment operation, the assembling efficiency can be improved. That is, it is possible to eliminate a great deal of labor for accurately assembling a large number of components on a plane as shown in FIGS.

[0029] The invention according to claim 7 is the invention according to claims 1 to 4.
In any one of the above, an aperture for regulating the diameter of a light beam incident on the deflection surface is provided integrally with the reflection surface.

According to the present invention, the accuracy of the incident position of the light beam on the deflecting surface and the accuracy of the arrangement of the light beam on the reflecting surface can be ensured by lamination without troublesome adjustment work, so that the assembling efficiency can be improved. .

The invention described in claim 8 is the first or second invention.
In the above description, the deflecting means is configured to perform two beams by an electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided to face the mirror substrate. Means for reciprocatingly oscillating the mirror substrate with the torsion rotation axis, and electrodes are provided on the substrate surface facing the surface of the mirror substrate opposite to the mirror surface and the frame end surface facing the mirror substrate end surface. .

According to the present invention, in addition to the above effects, the mirror substrate can be excited with a low voltage because the end surface of the mirror substrate and the electrode formed on the surface of the inner frame facing the mirror substrate are close to each other in the deflecting means. it can. Furthermore, when driven at the resonance frequency, the deflection width of the mirror substrate increases, and the mirror substrate end portion is close to the electrode surface opposite to the mirror surface having a larger area. The maintenance of the vibration can be further stabilized by driving the opposed electrodes.

According to a ninth aspect of the present invention, in accordance with the eighth aspect, a frame is provided on the mirror surface side of the mirror substrate, wherein the frame has an opening through which a light beam incident on the mirror substrate passes, and a mirror. An opening through which a light beam deflected by the substrate passes and a reflection surface facing the mirror surface are provided.

According to the present invention, light incident obliquely through the opening of the reflecting substrate and deflected and scanned by the mirror surface of the mirror substrate surface which reciprocates and vibrates is reflected by the reflecting substrate mirror. After multiple round trips to and from the surface, the light is emitted through the opening in the reflective substrate, so that the multiple reflections between the non-parallel mirrors increase the light reflection angle for each reflection, resulting in the same deflection angle of the mirror substrate. The scanning angle of the beam can be made larger. Therefore, light scanning over a wide range at a high frequency becomes possible.

According to a tenth aspect of the present invention, in the first or second aspect, the deflecting means is a mirror substrate supported by two beams provided on the same straight line, and a mirror substrate facing the mirror substrate. Means for reciprocatingly oscillating the mirror substrate using the two beams as torsional rotation axes by electrostatic attraction between the provided electrodes, and a frame is provided on the mirror surface side of the mirror substrate. An opening through which a light beam incident on the mirror substrate passes, an opening through which a light beam deflected by the mirror substrate passes, a reflecting surface facing the mirror surface, and an electrode facing the mirror surface are provided, and are opposed to the mirror substrate end surface. The electrode is provided at the position where the electrode is to be formed.

According to the present invention, since the electrodes are provided on the reflection substrate, there is no need to separately provide an electrode substrate, the structure is simple, the manufacturing can be performed at low cost, and the same effects as described above can be obtained. Becomes

According to an eleventh aspect of the present invention, there is provided an optical scanning device module according to any one of the first to tenth aspects, a synchronous detection sensor for detecting a light beam on the scanning start side and the end side, and a scanning lens. An optical scanning device comprising:

According to a twelfth aspect of the present invention, there is provided an image carrier,
An optical scanning device comprising: the optical scanning device module according to any one of claims 1 to 10, which is arranged in the main scanning direction of the image carrier.

According to a thirteenth aspect of the present invention, there is provided an image forming apparatus having the optical scanning device according to the eleventh or twelfth aspect.

According to the present invention, it is possible to provide an image forming apparatus using a high-precision optical scanning device with improved assembly efficiency.

According to a fourteenth aspect of the present invention, an electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided opposite to the mirror substrate is used. An optical scanning device module for reciprocatingly oscillating a mirror substrate with a torsion beam as a torsion rotation axis has electrodes on a substrate surface facing a surface of the mirror substrate opposite to the mirror surface and a frame end surface facing the mirror substrate end surface. .

According to the present invention, the mirror substrate can be excited with a low voltage because the electrode formed on the end surface of the mirror substrate and the surface of the frame inner frame facing the mirror substrate are close to each other. Furthermore, when driven at the resonance frequency, the deflection width of the mirror substrate increases, and the mirror substrate end portion is close to the electrode surface opposite to the mirror surface having a larger area. The maintenance of the vibration can be further stabilized by driving the opposed electrodes.

According to a fifteenth aspect of the present invention, in the method of the fourteenth aspect, the electrodes on the substrate surface opposite to the mirror surface of the mirror substrate are tilted about the torsional rotation axis. I do.

According to the present invention, since the electrode surface facing the opposite side of the mirror surface is formed so as to be inclined in a direction following the displacement of the mirror substrate, when the mirror substrate is inclined, the electrode surface including the end portion is included. Since the entire mirror substrate is close to the electrode surface, the vibration maintenance of the mirror substrate can be more stabilized than the effect described in claim 14.

According to a sixteenth aspect of the present invention, in accordance with the fourteenth aspect, a frame is provided on the mirror surface side of the mirror substrate, and the frame has an opening through which a light beam incident on the mirror substrate passes; An aperture through which the light beam deflected by the above passes and a reflection surface facing the mirror surface are provided.

According to the present invention, light incident obliquely through the opening of the reflective substrate and deflected and scanned by the mirror surface of the mirror substrate surface which reciprocates and vibrates is reflected by the mirror of the reflective substrate provided opposite to the mirror substrate. After multiple round trips to and from the surface, the light is emitted through the opening in the reflective substrate, so that the multiple reflections between the non-parallel mirrors increase the light reflection angle for each reflection, resulting in the same deflection angle of the mirror substrate. The scanning angle of the beam can be made larger. Therefore, light scanning over a wide range at a high frequency becomes possible.

According to a seventeenth aspect of the present invention, an electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided opposite to the mirror substrate is used. In an optical scanning device module for reciprocatingly oscillating a mirror substrate using a beam as a torsion rotation axis, a frame is provided on the mirror surface side of the mirror substrate, and the frame has an opening through which a light beam incident on the mirror substrate passes, and a mirror. An opening through which a light beam deflected by the substrate passes, a reflecting surface facing the mirror surface,
An electrode facing the mirror surface is provided, and the electrode is provided at a position facing the mirror substrate end surface.

According to the present invention, the above effects can be obtained, and since the electrodes are provided on the reflective substrate, there is no need to separately provide an electrode substrate, so that the structure can be manufactured simply and at low cost.

According to an eighteenth aspect of the present invention, in any one of the fourteenth to seventeenth aspects, the electrode facing the mirror substrate end face is formed at a portion that does not overlap the mirror substrate end face. I do.

According to the present invention, since there is no portion where the electrode overlaps with the mirror end surface, there is no electrostatic attraction that hinders the displacement of the mirror substrate, and the excitation of the mirror substrate at a lower voltage is possible.

According to a nineteenth aspect of the present invention, in any one of the fourteenth to seventeenth aspects, the mirror substrate end face and the electrode facing the mirror substrate have a comb tooth shape.

According to the present invention, since the area of the counter electrode is increased, the mirror substrate can be excited with a lower voltage.

According to a twentieth aspect of the present invention, in any one of the fourteenth to seventeenth aspects, the electrode provided to face the mirror substrate end face and the electrode facing the mirror face opposite to the mirror face are provided. The electrodes provided or the electrodes provided on the surface facing the mirror surface are not electrically connected, and the electrodes are driven with the timing of applying the voltage to each electrode shifted.

According to the present invention, the application timing of each voltage can be matched with the displacement due to the vibration of the mirror substrate, so that the mirror substrate can be driven more stably.

According to a twenty-first aspect of the present invention, in the sixteenth aspect, a surface of the mirror substrate facing the mirror surface includes:
Electrodes are provided on the surface facing the opposite side of the mirror surface and the surface facing the mirror substrate end surface, respectively, so that the electrodes are not conducted, and the electrodes are driven with the voltage application timing shifted to each electrode. .

According to the present invention, the application timing of each voltage can be matched with the displacement due to the vibration of the mirror substrate, and the electrostatic attraction of the upper and lower electrodes can be used.
More stable driving of the mirror substrate is possible at a lower voltage.

According to a twenty-second aspect of the present invention, the optical scanning device module according to any one of the fourteenth to twenty-first aspects is provided in a decompression container through which light can be transmitted and an electrode can be taken out. An optical scanning device module, comprising:

According to the present invention, since air resistance during vibration of the mirror substrate is eliminated, driving at a higher frequency becomes possible.

According to a twenty-third aspect of the present invention, a first substrate provided with a deflecting means for reflecting and scanning a light beam on a deflecting surface, and a second substrate provided with a reflecting surface at a position facing the deflecting surface.
And a third substrate defining a distance between the deflection surface and the reflection surface.
An optical scanning device module comprising: a substrate; and a laser beam that is reflected a plurality of times between the deflecting surface and the reflecting surface for scanning.

According to the present invention, the deflecting surface of the first substrate and the reflecting surface of the second substrate are formed on the respective substrate surfaces, and the distance between the two is defined by another substrate. A mirror-polished substrate surface can be used as the surface and the reflection surface.

According to a twenty-fourth aspect of the present invention, there is provided an optical scanning device module according to any one of the fourteenth to twenty-third aspects, a synchronization detection sensor for detecting a light beam on the scanning start side and the end side, and a scanning lens. An optical scanning device comprising:

According to a twenty-fifth aspect of the present invention, there is provided an image carrier,
24. Arranged in the main scanning direction of the image carrier.
An optical scanning device comprising the optical scanning device module according to any one of the above.

According to a twenty-sixth aspect of the present invention, there is provided an image forming apparatus including the optical scanning device according to any one of the twenty-fourth and twenty-fifth aspects.

According to a twenty-seventh aspect of the present invention, a light source unit substrate on which a light source is mounted and a deflecting unit substrate holding a deflecting unit having a deflecting surface for deflecting a light beam are stacked and provided, and are opposed to the deflecting surface. A method of controlling a deflecting means in an optical scanning device module that scans by reflecting a light beam a plurality of times between the reflecting surface and the deflecting surface, the method comprising: A voltage is applied to the electrode, and subsequently a voltage is applied to the first electrode facing the mirror surface or the first electrode facing the opposite side of the mirror surface, and after releasing the voltage, the voltage faces the end surface of the mirror substrate. A voltage is applied to the second electrode, and subsequently a voltage is applied to the second electrode facing the mirror surface or the second electrode facing the opposite side of the mirror surface. According to the present invention, the operation of the optical scanning device module can be reliably controlled.

According to a twenty-eighth aspect of the present invention, an electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided opposite to the mirror substrate is used. A method for controlling an optical scanning device module in which a mirror substrate is reciprocally oscillated using a beam as a torsion rotation axis, wherein a voltage is applied to a first electrode facing an end surface of the mirror substrate, and a first electrode facing the mirror surface is continuously applied. After applying a voltage to the first electrode facing the mirror surface or the first electrode facing the opposite side of the mirror surface and releasing the voltage, a voltage is applied to the second electrode facing the end surface of the mirror substrate, and then facing the mirror surface. A voltage is applied to the second electrode or the second electrode facing the opposite side of the mirror surface. According to the present invention, the operation of the optical scanning device module can be reliably controlled.

[0066]

FIG. 3 is a perspective view of an optical scanning module according to a first embodiment of the present invention. In this specification, a configuration in which each unit is integrated as shown in FIG. 3 is referred to as an optical scanning module, an optical scanning device module, or an optical scanning device. An apparatus as shown in FIG. 7, which will be described later, is called an optical scanning apparatus. The configuration of the portion that deflects the mirror is called a deflector, an optical scanning device, or an optical scanning device module.

As shown in FIG. 3, the optical scanning module according to the first embodiment of the present invention is configured by stacking respective substrates. FIG. 4 shows a cross-sectional view in a stacked state. Hereinafter, the optical scanning module according to the first embodiment will be described with reference to FIGS.

A lead terminal 202 is integrally formed on an electrode substrate 201 formed by ceramic molding, and a pair of magnets 203 is provided. The mirror section 20 pivotally supported by two torsion beams 205 is provided on the first silicon substrate 204.
6 is formed by anisotropic etching. Mirror unit 206
A coil portion is formed by evaporating a metal film on the periphery of the torsion beam 205. By passing a current through the coil, an electromagnetic force is applied to the torsion beam 205 by the electromagnetic force with the magnet 203 disposed outside the coil portion, and the amplitude is set to the rotation axis. . The central portion is a reflection surface made of the metal film. Note that the torsion beam 205 is adjusted so that the deflection speed in the mirror unit 206 matches the resonance frequency.
By setting the thickness of the mirror section 206, the mirror section 206 can be oscillated with a lower load.

An unillustrated wiring pattern is formed on the second silicon substrate 207 by depositing a metal film, and is connected to the lead terminal 202 by wire bonding or the like.

The semiconductor laser chip 208 can be formed by directly depositing an AlGaAs layer on a silicon substrate by using an epitaxial technique to form a cladding layer and an active layer constituting a semiconductor laser in parallel with the mounting surface. A semiconductor laser array chip having a plurality of light emitting sources manufactured separately so as to make the narrow side of the laser light into the sub-scanning direction is mounted via a submount so that the light emitting sources are arranged perpendicular to the mounting surface. On the other hand, the monitoring photodiode 209 for detecting the back light of the semiconductor laser is formed by directly depositing a GaAs layer on a silicon substrate.

The coupling lens 210 is a cylindrical anamorphic lens having different curvatures in a direction parallel to the mounting surface and a direction perpendicular to the mounting surface.
A part of the circumference is abutted on 11 and installed. The V-groove is formed so that the center axis of the coupling lens 210 coincides with the radiation center of the semiconductor laser.

In the semiconductor laser, two light emitting sources are formed at an interval of 14 μm. On the surface to be scanned, each beam spot is arranged at a predetermined interval in a direction perpendicular to the mounting surface (sub-scanning direction) to form two lines. Scan simultaneously.

The frame 212 uses a single-crystal Si substrate and anisotropically etches the light beam emitted from the coupling lens 210 on the aperture 21 formed on the substrate.
3, a reflecting portion 214 for guiding the mirror portion 206 to the mirror portion 206 and a reflecting portion 215 for guiding the back light of the semiconductor laser to the photodiode 209 are formed.

The light beam deflected and scanned by the mirror unit 206 is applied to a reflection unit 216 provided opposite to the back side of the second silicon substrate 207 at an interval of several 100 μm (g) as shown in FIG. In the example, the light is reciprocated N = 4 times, reflected, and emitted through the opening 217. In the case of the present embodiment, the rotation angle (shake angle) of the mirror unit 206 is about 3 °, and the scanning angle is increased to 3 ° × 2N = 24 ° by four reflections.

Here, in order to sequentially move and emit light in the sub-scanning direction, the distance between the reflection unit 215 and the mirror unit 206 should be g,
Assuming that the incident angle of the light beam on the mirror unit 206 in the sub-scanning direction is β and the light beam diameter in the sub-scanning direction is 2ω (the diameter of the aperture 213 in the embodiment), at least g · ta
By setting nβ> ω, the scanning angle can be obtained symmetrically with respect to the rotation axis.

Further, in the embodiment, the light beams are substantially parallel to each other. However, by setting the interval on the emission side (g1) slightly larger (g0 ≦ g1) than the light beam incidence side (g0), the light on the emission side is set. A margin for interference between the beam and the edge of the reflecting portion 216 can be increased.

In general, in order to increase the recording speed, it is necessary to raise the resonance point in order to increase the scanning frequency. However, since the torsion beam also becomes thicker, the rotation angle becomes smaller. Accordingly, by increasing the number of reflections to compensate for the reduction in the rotation angle, it is possible to cope without changing the angle of view of the scanning lens. The opposite is true when lowering the recording speed.

The sealing plate 218 is made of a transparent member and functions as a lens constituting a part of a scanning lens for forming an image of a light beam on a surface to be scanned, for example, correction of a scanning line bending due to oblique incidence on the mirror unit 206. The function is given to the emission window 219. In the embodiment, the opening of the aspherical shape is formed by photolithography in which the surface of the glass substrate has a change in concentration. However, even in the case of a diffraction grating or a distributed refractive index lens, only the lens portion is bonded. Is also good. Naturally, the sealing plate 2
The scanning lens 18 may be separately provided as a flat glass having no lens function.

In the figure, 220 and 221 are circuits for controlling the current supply to the semiconductor laser 208 and the coil portion, respectively, and are formed directly on each substrate.

The above-mentioned electrode substrate 201, first silicon substrate 204, second silicon substrate 207, frame 21
2. The optical scanning module is configured by sequentially stacking and joining the sealing plates 218.

The deflector in the first embodiment is of the type in which the mirror is vibrated by using an electromagnetic force, but may be configured to vibrate the mirror by using an electrostatic force. In that case, the magnet 203 is unnecessary. Also,
The configuration of the deflector using the electrostatic force will be described in detail in third to tenth embodiments described later.

Next, a description will be given of a second embodiment of the optical scanning module.

FIGS. 5 and 6 are a perspective view and a sectional view of an optical scanning module according to the second embodiment.

A lead terminal 302 is integrally formed on an electrode substrate 301 formed by ceramic molding. On the first silicon substrate 303, as shown in FIG. 6, the deflection disk portion 304 is cut out from the polycrystalline Si layer deposited on the substrate by etching and separated from the stator portion 322, and then an oxide film is formed only on the clearance portion of the bearing. And polycrystalline Si
To form a shaft portion 323 to form a shaft support portion.

A plurality of electrodes 306 serving as a stator are radially formed on the stator portion 322 by depositing a metal film, and an electrode 307 is also formed on the circumference of the deflection disk 304 so as to face the same. The drive is performed by the electrostatic force between the electrodes by sequentially switching the application of the current to the stator.

[0086] The deflection disk 304 is formed into a diffraction grating 305 by forming irregularities in the circumferential direction by the etching, and is simultaneously coated with the metal film. The incident light beam can be scanned at a scanning angle of about 1.5 times that of the grating according to the angle of the grating that changes with the rotation of the disk.
A reflection surface is provided on the lower surface of the lens and reflection is performed twice (N = two times) to increase the scanning angle.

The surface of the diffraction grating 305 is divided into a plurality of regions in the circumferential direction at equal angles, and in this embodiment, scanning for six surfaces is performed in one rotation. Generally, the recording speed can be increased by increasing the number of surfaces, but the rotation angle per surface is reduced. Therefore, as in the first embodiment, it is possible to cope with this by increasing the number of reflections to compensate for this without changing the angle of view of the scanning lens.

A wiring pattern (not shown) is similarly formed on the second silicon substrate 308 by vapor deposition of a metal film, and is connected to the above-mentioned lead terminals by wire bonding or the like.

As in the first embodiment, the semiconductor laser chip 309 uses a semiconductor laser array chip having a plurality of light emitting sources manufactured separately, but the submount 325 is arranged so that the light emitting sources are arranged perpendicular to the mounting surface. Implemented via

The monitoring photodiode 310 for detecting the back light of the semiconductor laser is formed directly on the silicon substrate. The coupling lens 311 is a cylindrical anamorphic lens having different curvatures in a direction parallel to the mounting surface and in a direction perpendicular to the mounting surface, and has a V-groove 312 formed on a silicon substrate.
And a part of the circumference is abutted. The V-groove is formed so that the center axis of the coupling lens 311 coincides with the radiation center of the semiconductor laser.

In the semiconductor laser, two light emitting sources are formed at an interval of 14 μm. On the surface to be scanned, each beam spot is arranged at a predetermined interval in a direction perpendicular to the mounting surface (sub-scanning direction) to form two lines. Scan simultaneously.

The light beam emitted from the coupling lens 311 is passed through the aperture 316 formed on the substrate to the frame 313 and the deflection disk 30 serving as a deflector.
4 and a reflecting portion 315 for guiding the back light of the semiconductor laser to the photodiode 310 are formed. In this embodiment, as in the first embodiment, a reflection portion was formed by anisotropic etching using a single crystal Si substrate. The aperture 316 shapes the light beam diameter of the light beam and blocks disturbance light.

The light beam deflected and scanned by the deflection disk 304 is emitted through an opening 317 provided in the substrate.

The sealing plate 318 is made of a transparent member, and the exit window 319 has the function of a lens constituting a part of a scanning lens that forms a light beam on a surface to be scanned.

In the figure, reference numerals 320 and 321 denote circuits for controlling current supply to the semiconductor laser 309 and the stator electrode 306, respectively, and are formed directly on each substrate.

The above-mentioned electrode substrate 301, first silicon substrate 303, second silicon substrate 304, frame 31
3. An optical scanning module is formed by sequentially laminating and joining the sealing plates 318.

Next, an example of an optical scanning device using the optical scanning module described in the first and second embodiments will be described. In the optical scanning device shown in FIG. 7, a plurality of optical scanning modules are arranged on one electrical board 402 such that the main scanning is divided into a plurality of areas and the optical scanning modules are assigned to each area. A synchronization detection sensor 4 for detecting a light beam on each scanning start side and end side is provided on the electrical board.
03 and peripheral circuits of the control circuits 220 and 221 are formed, and are positioned and fixed by soldering so as to match the angle and scanning position of the scanning line between the optical scanning modules.

The light beam emitted from each optical scanning module forms an image on the surface to be scanned via the scanning lens 404. Each lens portion of the scanning lens is integrally formed of resin, and a light beam emitted from the optical scanning module is returned to the synchronization detection sensor 403 by a mirror 405 provided near the scanning lens to be incident.

In this embodiment, the main scan is divided into a plurality of
Although the scanning is performed by using one beam, the configuration is the same even when the entire scanning width is scanned by one optical scanning module or when a one-beam semiconductor laser is used.

The optical scanning device as shown in FIG. 7 is used, for example, in the image forming apparatus shown in FIGS. 8 shows the configuration of a digital copying machine, FIG. 9 shows the configuration of a laser printer, and FIG. 10 shows the configuration of a plain paper facsimile.

In each figure, reference numeral 500 denotes an image forming apparatus main body;
Reference numeral 501 denotes an optical scanning device as shown in FIG. 7, reference numeral 502 denotes a cassette for accommodating paper, reference numeral 504 denotes a paper feed roller for taking out paper one by one from the cassette, reference numeral 506 denotes a registration roller for controlling conveyance timing, and reference numeral 508 denotes a transfer charger. ,
510, a process cartridge which is a photosensitive drum 512;
The developing roller 513, the charging roller 514, and the like are integrated. Reference numeral 516 denotes a fixing roller having a built-in halogen heater, and 518 denotes a pressure roller, which constitutes a fixing device. Further, 520 is a transport roller, and 522 is a paper discharge roller.

The optical scanning device 501 forms a latent image on the photosensitive drum 512 uniformly charged by the charging roller 514 by modulating the semiconductor laser in accordance with the image signal, and uses the toner supplied from the developing roller 513. It is visualized. On the other hand, the sheet taken out by the sheet feeding roller 504 is conveyed by the registration roller 506 in synchronization with the image writing timing of the optical scanning device 501, and the toner image is transferred. The transferred image is fixed by the fixing roller 516 and discharged.

In particular, in FIG. 8, reference numeral 511 denotes a reading apparatus main body, which forms an image on a reading section 523 of a document fixed on a document table on a photoelectric conversion element 525 such as a CCD via an image forming lens 524, and a mirror. The group 522 is moved and sequentially converted into electronic data. Further, a second paper cassette 504 'is provided.

In FIG. 10, reference numeral 527 denotes a document reading device. The image of the document sent out from the document table 515 by the paper feed roller 529 is transported by a pair of transport rollers 526 and 52.
8 and sequentially converted into electronic data while being conveyed.

As described above, the deflector in the first embodiment may be a mechanism using electrostatic force. Here, electrostatically driven deflectors (hereinafter, referred to as optical scanning devices) capable of obtaining a stable vibration with a large deflection angle will be described as third to tenth embodiments. These can all be used as a part in the optical scanning module shown in the first embodiment. Further, the present invention is not limited to this, and can be used in other configurations.

FIG. 11 shows the configuration of an optical scanning device according to the third embodiment of the present invention. a is a front view of the entire optical scanning device,
b is a cross-sectional view of the center of the optical scanning device including the driving electrodes.

The mirror substrate 601 is supported at its center by two torsion beams 602 and 603 provided on the same straight line. The two torsion beams 602 and 603 are set to have a cross-sectional dimension, a shape, and a length so as to have rigidity such that a deflection angle required by the mirror substrate is obtained. It is fixed to the inner frame 604. The end surfaces 606 on both sides of the mirror substrate 601 which are not supported by the torsion beams are formed so as to be close to and opposed to the frame inner frame 604 provided outside the mirror portion.

The frame is an integral frame inner frame 6
04 and an outer frame 605. The inner frame has a part of an end surface serving as an electrode. The outer frame is thicker than the inner frame and the lower side thereof is joined to the electrode substrate 612. Frame is made of insulating material 60
7, electrodes 608 and 609 are formed on the insulating material on the end face of the frame inner frame at a position close to and opposed to the end face 606 of the mirror substrate. Since the frame inner frame 604 is thicker than the mirror substrate, the electrodes 608 and 6 provided in close proximity to the mirror substrate end surface are provided.
Reference numeral 09 extends to a portion that does not overlap the mirror substrate end surface in the thickness direction of the end surface. A portion of the frame outer frame 605 on the mirror surface side is provided with a portion where the frame is exposed without being covered with an insulating material, and a pad 610 for leading out an electrode is formed in that portion. Mirror substrate 60
On the mirror 1, a mirror 611 having a sufficient reflectance for the light to be used is formed.

Below the frame outer frame 605 is an electrode substrate 612.
And an insulating material 61 on the electrode substrate 612.
3 is formed, and two electrodes 614 and 615 are formed on both sides of the center position of the deflection of the mirror on the surface of the mirror substrate 601 on the surface opposite to the mirror surface. Are drawn out to the outside of the frame, and the terminals 616 and 61 for extracting electrodes are taken out of the frame.
It is 7. At the joint position between the frame and the electrode substrate, the electrode on the electrode substrate and the electrode on the end face of the frame are electrically connected via the conductive material 618.

Next, a method of manufacturing the optical scanning device according to the third embodiment of the present invention will be described with reference to FIG.

For the mirror substrate, the torsion beam, and the frame, a low-resistance silicon substrate that can be easily processed with high precision and can use the substrate itself as a common conductive material is used.

Each of the two silicon substrates 701 and 702 having a thickness of 200 μm and having both sides polished has a thickness of 1 μm on both surfaces.
Is formed by thermal oxidation, and the SiO2 film of one of the silicon substrates 701 is etched away with hydrofluoric acid only on one side. At this time, the surface on which SiO2 is to be left is protected with a resist. After sufficiently cleaning both silicon substrates using a mixed solution of sulfuric acid and hydrogen peroxide solution, the silicon surface of the silicon substrate 701 is brought into contact with the SiO2 film surface of the silicon substrate 702 via the SiO2 film 703. After temporary bonding under a reduced pressure atmosphere of 500 ° C., direct bonding is performed at 1100 ° C. in a nitrogen atmosphere (a). Next, the SiO 2 film on the surface of the silicon substrate 702 of the two bonded substrates is etched away with hydrofluoric acid to have a thickness of 80 u.
Polishing with high precision by CMP (Chemical Mechanical Polishing) up to m. The thickness of the silicon substrate obtained here becomes the thickness of the mirror substrate. After that, the silicon on the polished surface is thermally oxidized to form a SiO2 film 704 having a thickness of 1 μm on the surface again (b).

Next, the SiO 2 film 705 on the silicon substrate 701 is patterned into a frame outer frame shape by etching it with hydrofluoric acid using a resist as a mask (c). Next, S patterned in the outer frame shape of the frame
Using the iO2 film 705 as a mask, the silicon substrate 701 is anisotropically etched with a 30% KOH aqueous solution at 85 ° C. to a depth of 100 μm (d). Here, a KOH solution was used as an anisotropic etching solution, but silicon and SiO 2 were used.
Other anisotropic etchants having a sufficiently high etching selectivity, such as TMAH and hydrazine, may be used.
Although SiO2 is used here as a mask material for anisotropic etching, another thin film material that is not etched by a silicon etchant, such as a SiN film or S
An iN / SiO2 bilayer film or the like may be used. Next, the silicon substrate 701 lowered one step by anisotropic etching
Is thermally oxidized to form a SiO2 film 706 having a thickness of 1 μm (e).

Next, the SiO2 film 706 on the silicon substrate 701, which has been lowered one step by anisotropic etching, is patterned into a frame shape by etching with hydrofluoric acid using a resist as a mask (f). Then, an inner portion of the silicon substrate from which the SiO2 has been removed is patterned into an inner frame shape of the SiO2 film 7.
07 as a mask, the etching rate of ICP-RIE or the like is large and the anisotropic dry etching
Etching is removed until the iO2 film 703 appears. Part of the end surface 708 of the silicon substrate 701 formed here is used as an electrode formation surface on the frame side (g). Next, the end face 70 of the silicon substrate 701 obtained by dry etching
8 is thermally oxidized to form a 1 μm thick SiO 2 film 709 on the surface (h).

Next, a Ti thin film 300 is formed on the thermal oxide film on the side of the silicon substrate 701 by sputtering, and a Pt thin film 1200 is formed by sputtering. The Ti thin film is for improving the adhesion of the Pt thin film on the oxide film. Here, the Pt thin film 710 is used.
Is used as an electrode material, but other materials such as Au, Ti, and Al may be used as long as they are thin films having high conductivity. Although a sputtering method is used here as a film forming method, a film may be formed by another method such as a vacuum evaporation method and an ion plating method. At the time of film formation, it is shielded with a metallic stencil mask so that a metal thin film is not formed in a region other than the electrode. (I) Next, the SiO2 film 704 formed on the silicon substrate 702 side is etched with hydrofluoric acid using a resist as a mask, thereby patterning into a frame inner frame, a mirror substrate, and a beam shape (j). Next, S
The silicon substrate 702 is formed using the iO2 film 704 as a mask.
An etching rate such as ICP-RIE is high and anisotropic dry etching is performed to remove the SiO2 film 703 on the bonding surface by dry etching, and then the SiO2 film 7 on the bonding surface is removed.
03. The metal thin film 710 is also removed by dry etching to form a frame, a mirror substrate, and a beam through.
(K, l) Next, the SiO2 film 70 of the silicon substrate 702
Then, a metal thin film 711 to be a mirror surface is formed on the surface via 4 (m). Here, Al was formed as a metal thin film by a sputtering method, but other materials such as Au can be selected as long as the metal thin film can provide a necessary and sufficient reflectance to a laser beam to be used. Not only the method but also a vacuum deposition method can be used.

The electrode substrate and the frame, to which the mirror substrate supported by the torsion beams thus manufactured is fixed, are adhered by the conductive adhesive 716 (n). At this time,
The adhesive is provided in a recess formed in the frame so that the frame and the substrate are in direct contact with each other without an intervening adhesive layer. The electrode substrate 712 is made of SiO.sub.
A silicon substrate on which the two films 713 are formed is used. If the surface is insulating, a glass substrate or the like may be used instead. A metal thin film to be the electrodes 714 and 715 is formed on the surface of the substrate. At this time, a metal stencil mask is used to shield the metal thin film from being formed in a region other than the electrode.

The operation of the optical scanning device according to the third embodiment of the present invention will be described below with reference to FIG. Using the mirror substrate 601 supported by the two torsion beams as a common electrode, an electrode extraction pad 610 and an electrode extraction pad 616 extracted from one electrode 614 provided on the electrode substrate.
During this time, a voltage of 30 V is applied.

At this time, since the electrode 614 is electrically connected to the electrode 608 on the end face of the frame inside the frame, the electrostatic attractive force is applied between the electrode 608 on the end face of the frame inside the frame and the mirror substrate end face 606 provided so as to be close to and opposed to the electrode 608. Works. Electrostatic attraction also occurs between the electrode 614 provided on the electrode substrate and the mirror substrate 601, but since the distance between the electrodes is larger than that between the electrodes on the end face, the force is larger than the electrostatic attraction between the end face electrodes. Is also small,
Excitation of the mirror substrate is mainly caused by electrostatic attraction between the end face electrodes. At this time, the electrode 6 on the end face of the inner frame
08 is formed wider in the mirror oscillation direction than the mirror substrate end surface 606 provided in close proximity to the mirror substrate end surface 606, so that the mirror substrate end surface is drawn in the downward direction where the electrodes on the inner frame end surface are wider. , Torsion beams 602, 6
The mirror substrate 601 rotates around 03 as an axis. When the application of the voltage is stopped, the electrode substrate 601 has two beams 602 and 603.
Due to the torsional rigidity, it is returned in the direction opposite to the direction attracted by the electrostatic attraction, and after reaching the horizontal position, rotates above the position due to the inertial force.

Here, when the electrode substrate is positioned horizontally,
An electrode extraction pad 610 and an electrode extraction pad 61 extracted from the other electrode 615 provided on the electrode substrate.
A voltage of 30 V is applied during 7. At this time, the electrode 61
5 is electrically connected to the electrode 609 on the end face of the frame inner frame, so that an electrostatic attractive force acts between the electrode 609 on the end face of the frame inner frame and the mirror substrate end face 606 provided in close proximity thereto. At this time, the electrode 609 on the end face of the inner frame of the frame is formed wider in the direction of the mirror oscillation than the end face 606 of the mirror substrate provided so as to be close to the lower end of the frame. The mirror substrate end face is attracted in the lateral direction, and the mirror substrate 601 rotates around the torsion beams 602 and 603 in the direction opposite to when the voltage is applied to the electrode 608. The electrostatic attraction for the rotation in the opposite direction is superimposed on the force for rotating the other end upward from the horizontal position due to torsional rigidity and inertia when the application of the voltage to the electrode 608 is stopped. become.

As described above, by alternately applying a voltage to the extraction electrodes 616 and 617 using the electrode pad 610 as a common electrode, the mirror substrate can be reciprocated around the torsion beam. When the driving frequency of the reciprocating vibration is set to the resonance frequency of the mirror substrate, the deflection width of the mirror substrate increases, and the electrodes 614 and 615 on the electrode substrate are increased.
Can be displaced to a position close to the mirror substrate. The area of the electrodes 614 and 615 is larger than the area of the electrodes 608 and 609 on the end face of the inner frame of the frame. Therefore, if the electrodes can be brought close to the same distance, the electrostatic attraction is larger. Since the mirror substrate ends reach the positions close to the electrodes 614 and 615 by resonance, the electrodes 614 and 615 also contribute to the driving of the mirror substrate, and the vibration can be more stably maintained by both the end and the flat surface electrodes. .

Next, an optical scanning device according to a fourth embodiment of the present invention will be described. The configuration of the optical scanning device in this embodiment is the same as that of the third embodiment except for the inclined portion of the electrode substrate. Therefore, only the configuration of the inclined portion of the electrode substrate will be described with reference to the central sectional view 13 including the drive electrode.

The electrode substrate 812 is joined below the outer frame of the frame, and the electrode substrate is inclined in the direction of the mirror shake with the center of the mirror shake below the top of the ridge. An insulating material 813 is formed on the electrode substrate, and two electrodes 814 and 81 are provided on both sides of the center position of the deflection of the mirror on the surface of the mirror substrate on the opposite side to the mirror surface.
5 are formed, and the two electrodes are respectively drawn out to the outside of the frame, and the outside of the frame serves as electrode extraction terminals 816 and 817. At the joining position between the frame and the electrode substrate, the electrode on the electrode substrate and the electrode on the end face of the frame are electrically connected via the conductive material 818.

The manufacturing method of the optical scanning device according to the fourth embodiment of the present invention is the same as the manufacturing method of the first embodiment except for the inclined portion of the electrode substrate. Therefore, only the method of manufacturing the inclined portion of the electrode substrate will be described with reference to FIG.

First, a 525 μm-thick silicon substrate 90
100 μm thick dry film resist 902
Is formed (a). Next, the exposure depth of the dry film resist is made to have a distribution by using a photomask having a distribution of the aperture ratio. The distribution shape is designed so that the electrode shape is inclined. By developing this dry film resist, a dry film resist shape 903 reflecting the electrode shape is formed (b). By dry-etching the silicon substrate 901 using this dry film resist as a mask, the shape of the dry film resist is transferred to the silicon substrate according to the etching selectivity between the resist and silicon (c).

Next, an SiO 2 film 904 is formed as an insulating material on the surface of the silicon substrate by thermal oxidation (d). On the surface of the substrate, a metal thin film to be the electrodes 905 and 906 is formed and manufactured (e). At this time, a metal stencil mask is used to shield the metal thin film from being formed in a region other than the electrode.

The operation of the optical scanning device according to the fourth embodiment of the present invention will be described below with reference to FIG.

The operation of the optical scanning device in this embodiment is basically the same as the operation of the optical scanning device in the third embodiment. Using the electrode pad as a common electrode, the extraction electrode 8
By alternately applying a voltage of 30 V to the mirror substrate 16 and 817, the mirror substrate reciprocates around the torsion beam. When the driving frequency of the reciprocating vibration is set to the resonance frequency of the mirror substrate, the deflection width of the mirror substrate becomes As a result, the mirror substrate end face can be displaced to a position close to the electrodes 814 and 815 on the electrode substrate. The electrodes 814 and 815 are larger in area than the electrodes 808 and 809 on the end face of the inner frame of the frame, and are formed to be inclined so as to follow the displacement of the mirror substrate. Also, when the mirror substrate is tilted, the electrostatic attraction is larger because the area of the electrodes approaching when the mirror substrate is tilted is larger, and the mirror substrate can be more stably vibrated.

Next, an optical scanning device according to a fifth embodiment of the present invention will be described.

The configuration of the optical scanning device of this embodiment is the same as that of the third embodiment except that a reflection substrate is provided on a mirror substrate. Therefore, only the configuration of the reflection substrate on the mirror substrate will be described with reference to FIG.

A 200 μm thick silicon substrate 1001 is joined on the outer frame of the frame as a spacer between the mirror substrate and the reflection substrate. A reflective substrate frame 1002 formed by anisotropic etching from a 525 μm-thick silicon substrate is joined to a silicon substrate 1001 as a spacer. The inside of the frame of the reflective substrate is 200 μm thick formed by anisotropic etching.
The diaphragm 1003 has an opening 1004 through which a beam incident on a mirror substrate formed by anisotropic etching passes, an opening 1005 through which a beam deflected by the mirror substrate passes, and a mirror of the mirror substrate. Al at the position facing the surface by sputtering
Is provided with a mirror surface 1006 of a reflective substrate on which is formed.

The anisotropic etching was performed at 85 ° C. with a 30% aqueous KOH solution using the SiO 2 film as a mask. Note that another anisotropic etchant having a sufficiently large etching selectivity between silicon and SiO2, such as TMAH or hydrazine, may be used. Further, although SiO2 is used here as a mask material for anisotropic etching, another thin film material that is not etched by a silicon etchant, for example, a SiN film, a SiN / SiO2 bilayer film, or the like may be used. . Further, here, Al was formed as a metal thin film by a sputtering method, but other materials such as Au can be selected as long as the metal thin film can provide a necessary and sufficient reflectance to a used laser beam. Not only the sputtering method but also a vacuum evaporation method can be used.

The operation of the mirror section of the optical scanning device according to the present embodiment is the same as the operation of the optical scanning device according to the third embodiment, but the behavior of light by the mirror section and the reflection substrate is different. The light that is incident at an angle of 15 ° through the opening 1004 of the reflective substrate and that is deflected and scanned by the mirror surface of the mirror part surface that reciprocates vibrates. After reciprocating four times with the mirror surface, the light is emitted through the opening 1005 of the reflection substrate. At this time, the reflection angle of the light spreads for each reflection due to the four multiple reflections between the non-parallel mirrors, and when the driving frequency of the mirror substrate is 5 kHz and the deflection angle is 3 °, a beam scanning angle of 24 ° is obtained. be able to.

Next, FIG. 16 shows the configuration of an optical scanning device according to a sixth embodiment of the present invention. 1A is a front view of the entire optical scanning device, and FIG. 2B is a sectional view of the center of the optical scanning device including a driving electrode.

The mirror substrate 1101 is supported at its center by two torsion beams (not shown) provided on the same straight line. The two torsion beams are fixed to a common frame inner frame 1104 provided outside the mirror section.
The end surfaces 1106 on both sides of the mirror substrate 1101 that are not supported by the torsion beams are formed to be close to and opposed to the frame inner frame 1104 provided outside the mirror portion.

The frame is composed of two silicon substrates 1102,
An inner frame 1104 and an outer frame 1 are formed by bonding an inner layer 1103 with an oxide film 1110 therebetween.
105. The inner frame has a part of an end surface serving as an electrode, and the outer frame is thicker than the inner frame. The frame is covered with an insulating material 1107, and the mirror substrate end face 11
Electrodes 1108 and 1109 are formed on the insulating material on the end face of the inner frame at a position close to and opposing to 06. Since the frame inner frame is thicker than the mirror substrate, the electrodes provided in close proximity to the mirror substrate end face are drawn out to a portion that does not overlap the mirror substrate end face in the thickness direction of the end face. A portion of the frame outer frame opposite to the mirror surface is not covered with an insulating material and is provided with a portion where the frame is exposed, and a pad (not shown) for leading out an electrode is formed in that portion. Mirror substrate 1
On the mirror 101, a mirror 1111 having a sufficient reflectance for the light to be used is formed.

A frame 1112 of a reflection substrate formed by anisotropic etching from a silicon substrate having a thickness of 525 μm is joined on the frame outer frame. The inside of the frame of the reflective substrate is a diaphragm 1113 having a thickness of 200 μm formed by anisotropic etching.
The diaphragm has an opening 1114 through which a beam incident on a mirror substrate formed by anisotropic etching passes.
And the opening 11 through which the beam deflected by the mirror substrate passes
15 and a mirror surface 111 of a reflective substrate in which Al is formed by sputtering at a position facing the mirror surface of the mirror substrate.
6 are provided.

An insulating material 1117 is formed on the reflection substrate, and two electrodes 1118 and 1119 are formed on both sides of a surface of the mirror substrate on the surface facing the mirror surface. Are drawn out to the outside of the frame outer frame of the mirror substrate, and outside the frame are electrode extraction terminals 1120 and 1211. At the joining position between the frame and the electrode substrate, the electrode on the electrode substrate and the electrode on the end face of the frame are electrically connected via the conductive material 1122.

A method for manufacturing an optical scanning device according to the sixth embodiment of the present invention will be described with reference to FIG.

For the mirror substrate, the torsion beam, and the frame, a low-resistance silicon substrate that can be easily processed with high precision and can use the substrate itself as a common conductive material is used.

Both sides of a 200 μm-thick double-side polished silicon substrate 1201 and a 525 μm-thick double-side polished silicon substrate 1202 are coated on both sides with a 1 μm-thick SiO 2
The film is formed by thermal oxidation. The SiO 2 film of one of the silicon substrates 1201 is etched away on one side only with hydrofluoric acid. At this time, the surface on which SiO2 is to be left is protected with a resist. After sufficiently cleaning both silicon substrates using a mixture of sulfuric acid and hydrogen peroxide solution, the silicon surface of the silicon substrate 1201 and the SiO2 film surface of the silicon substrate 1202 are brought into contact with each other via the SiO2 film 1203. After temporary bonding under a reduced pressure atmosphere of 500 ° C., direct bonding is performed at 1100 ° C. in a nitrogen atmosphere (a).

Next, the SiO 2 on the silicon substrate 1202
The film 1205 is patterned into a frame outer frame by etching with hydrofluoric acid using a resist as a mask (b), and then the silicon substrate 12 is patterned using the SiO2 film 1205 patterned into the frame outer frame as a mask.
02 is anisotropically etched to a depth of 145 μm with a 30% KOH aqueous solution at 85 ° C. (c). Here, a KOH solution was used as an anisotropic etching solution, but silicon and S
Other anisotropic etchants having a sufficiently high etching selectivity of iO2, such as TMAH and hydrazine, may be used. Although SiO2 is used here as a mask material for anisotropic etching, other thin film materials that are not etched by a silicon etchant, for example, SiN
A film, a SiN / SiO2 bilayer film or the like may be used. Next, the surface of the silicon substrate 1202, which has been lowered one step by anisotropic etching, is thermally oxidized to form a 1 μm thick SiO 2 film 1.
206 is formed (d).

Next, the SiO 2 on the silicon substrate 1201 is
The film 1207 is patterned into a frame outer frame shape by etching with hydrofluoric acid using a resist as a mask (e). Next, using the SiO2 film 1207 patterned into the outer frame shape of the frame as a mask, the silicon substrate 1
201 to a depth of 100 um at 85 ° C, 30% KOH
Perform anisotropic etching with an aqueous solution (f). Here, a KOH solution was used as the anisotropic etching solution, but another anisotropic etching solution having a sufficiently large etching selectivity between silicon and SiO 2, for example, TMAH, hydrazine or the like may be used. Further, here, SiO2 is used as a mask material at the time of anisotropic etching, but other thin film materials that are not etched by a silicon etchant, for example, Si
An N film, a two-layer SiN / SiO 2 film, or the like may be used. Next, the surface of the silicon substrate 1201 lowered by one step by anisotropic etching is thermally oxidized to form a 1 μm thick SiO 2 film 1208 (g).

Next, the SiO 2 film 1208 on the silicon substrate 1201 lowered by one step by anisotropic etching
By etching with a hydrofluoric acid using a resist as a mask, thereby patterning into a frame shape in a frame (h),
SiO2 film 1209 obtained by patterning the inner portion of the silicon substrate from which SiO2 has been removed into an inner frame shape.
Using a mask as a mask, dry etching with a large etching rate such as ICP-RIE and anisotropic
Etching is removed until the two films 1203 appear. Part of the end surface 1210 of the silicon substrate 1201 formed here is used as an electrode formation surface on the frame side (i). next,
The end surface 1210 of the silicon substrate 1201 obtained by dry etching is thermally oxidized to form a 1 μm thick SiO 2 film 1211 on the surface (j).

Next, after a Ti thin film 300 Å is formed on the thermal oxide film on the side of the silicon substrate 1201 by a sputtering method, a Pt thin film 1200 成膜 is formed by a sputtering method. The Ti thin film is for improving the adhesion of the Pt thin film on the oxide film. Also, here, the Pt thin film 121 is used.
Although 2 is used as an electrode material, other materials such as Au, Ti, and Al may be used as long as they are thin films having high conductivity. Although a sputtering method is used here as a film forming method, a film may be formed by another method such as a vacuum evaporation method and an ion plating method. At the time of film formation, it is shielded with a metallic stencil mask so that a metal thin film is not formed in a region other than the electrode. (K) Next, the SiO2 film 1206 formed on the silicon substrate 1202 side is etched with hydrofluoric acid using a resist as a mask, thereby patterning into an inner frame, a mirror substrate, and a beam shape (l). Next, using the SiO 2 film 1206 as a mask, the silicon substrate 1
202 is subjected to dry etching with a high etching rate such as ICP-RIE and a high anisotropy to form the SiO2 film 1
The frame, the mirror substrate, and the beam are formed by removing the SiO2 film 1203 and the metal thin film 1212 on the bonding surface by dry etching. (M, n)
The outer frame of the frame, to which the mirror substrate supported by the torsion beams is fixed, and the reflective substrate are bonded with a conductive adhesive 1213 (o). At this time, the adhesive is provided in a concave portion formed in the frame so that the frame and the substrate are in direct contact with each other without an adhesive layer.

Thickness 200 u inside the frame of the reflection substrate
The m diaphragm 1214 is formed by anisotropic etching. An opening 1215 through which a beam incident on a mirror substrate formed on the diaphragm passes and an opening (not shown) through which a beam deflected by the mirror substrate passes are formed by anisotropic etching. A mirror surface (not shown) of the reflection substrate provided at a position facing the mirror surface of the mirror substrate and an electrode 1216 of the reflection substrate;
Reference numeral 1217 forms an Al film by a sputtering method. At this time, a metal stencil mask is used to shield the metal thin film from being formed in a region other than the mirror and the electrode. Here, the anisotropic etching is performed using the SiO2 film as a mask for 85.
C., 30% KOH aqueous solution. Note that silicon and S
Other anisotropic etchants having a sufficiently high etching selectivity of iO2, such as TMAH and hydrazine, may be used. Although SiO2 is used here as a mask material for anisotropic etching, other thin film materials that are not etched by a silicon etchant, for example, SiN
A film, a SiN / SiO2 bilayer film or the like may be used. Further, here, Al was formed as a metal thin film by a sputtering method, but other materials such as Au can be selected as long as the metal thin film can provide a necessary and sufficient reflectance to a used laser beam. Not only the sputtering method but also a vacuum evaporation method can be used.

The operation of the mirror section of the optical scanning device according to the present embodiment is the same as the operation of the optical scanning device according to the first embodiment, and the behavior of light by the mirror section and the reflection substrate is the same as that of the third embodiment. Therefore, the description is omitted. In the sixth embodiment, since the electrodes are provided on the reflective substrate, there is no need to separately provide an electrode substrate, and the structure is simple and the manufacturing can be performed at low cost.

Next, a seventh embodiment of the present invention will be described. FIG. 18 shows a cross-sectional configuration at the center including the drive electrodes of the optical scanning device in the seventh embodiment. The structure of the optical scanning device according to the present embodiment is the same as the structure of the optical scanning device according to the sixth embodiment except for the shape of the electrodes on the end faces of the inner frame of the frame. Seventh
In the embodiment of the present invention, electrodes 1301 and 1302 are formed on the insulating material on the end surface of the inner frame and on the portion that does not overlap the mirror substrate end surface in the thickness direction of the end surface. According to the seventh embodiment, since there is no portion where the electrode overlaps the mirror end surface, there is no electrostatic attraction that hinders the displacement of the mirror substrate generated at that portion, and it is possible to excite the mirror substrate at a lower voltage.

Next, an eighth embodiment of the present invention will be described. FIG. 19 shows a cross-sectional configuration of the center including the drive electrodes of the optical scanning device according to the eighth embodiment of the present invention.

The structure of the optical scanning device in this embodiment is the same as that of the optical scanning device in the sixth embodiment except for the shape of the electrodes provided on the reflection substrate. Illustrated. In the eighth embodiment, the electrodes 1403 and 1404 on the reflection substrate are not electrically connected to the electrodes 1401 and 1402 on the end faces of the inner frame of the frame, and a voltage can be applied to each of them independently.

Next, a ninth embodiment of the present invention will be described. FIG. 20 shows a cross-sectional view of the configuration including the drive electrodes of the optical scanning device according to the ninth embodiment of the present invention.

The structure of the optical scanning device according to the present embodiment is the same as that of the optical scanning device according to the fifth embodiment except that electrodes are provided on the reflective substrate. Only illustrated. In the ninth embodiment,
The electrodes 1503 and 1504 on the reflective substrate are not electrically connected to the electrodes 1501 and 1502 on the end surface of the inner frame of the frame, and a voltage can be applied to each of them independently.

Next, a tenth embodiment of the present invention will be described. FIG. 21 shows a cross-sectional configuration at the center including the drive electrodes of the optical scanning device according to the tenth embodiment.

The structure of the optical scanning device according to the present embodiment is the same as the structure of the optical scanning device according to the third embodiment, except for the electrode shapes of the mirror substrate end face and the frame inner frame end face opposed thereto. Here, only portions having different structures are shown. The mirror substrate end surface 1601 is bent and processed in a comb-like shape, and electrodes 1603 and 1604 bent in a comb-like shape are formed on the insulating material on the end surface of the frame inner frame 1602 so as to face the mirror substrate end surface. I have. The comb-teeth shape increases the area of the counter electrode, so that the mirror substrate can be excited with a lower voltage.

Next, FIG. 22 shows a connection configuration between a write control unit for controlling the operation of the optical scanning device according to the third to tenth embodiments of the present invention and an electrode for swinging the mirror. In FIG. 22, a configuration close to that of the sixth embodiment is taken as an example, but the principle is the same in other embodiments. This writing control unit can be provided, for example, as 221 in FIG.

FIG. 23 is a timing chart showing the timing of applying a voltage to each electrode. Here, the operation will be described with reference to this timing chart.

The supporting substrate of the oscillating mirror is provided with electrodes 1a and 1b opposed to the end face symmetrically with respect to the rotation axis and electrodes 2a and 2b opposed to the mirror surface. The mirror is horizontal in the steady state (θ = 0). First, by applying a voltage to the electrode 1a, the beam that supports the mirror is twisted by electrostatic attraction to tilt the mirror clockwise, and then a voltage is applied to the electrode 2a. As a result, the beam rotates to an angle (-θ) at which the restoring force of the beam and the electrostatic attraction balance. When the voltage is released at this point, the mirror tries to return to the steady state. However, when the voltage is further applied to the electrode 1b, the mirror rotates left beyond the horizontal and continues to apply the voltage to the electrode 2b, so that the restoring force of the beam and the electrostatic attractive force are obtained. Rotate to the angle (+ θ) where By repeating this operation, the mirror reciprocates.

Starting from the angle -θ until reaching + θ, one scan is defined as one scan.
1 is turned on, a beam is detected by the sensor 1703, a synchronization signal is generated, and image recording is performed.

By the way, in the first and second embodiments of the present invention,
Scanning is performed after the laser beam is reflected at least twice between the mirror section (referred to as a deflecting surface) and a reflecting surface disposed at a position facing the deflecting surface. For this purpose, it is necessary to accurately define the distance between the deflecting surface and the reflecting surface and the dimensions of the reflecting surface. Therefore, when a concave shape is formed on a substrate on which a deflecting surface or a reflecting surface is provided so that the distance can be defined by its depth, the bottom surface of the concave shape formed by etching or polishing is rough, so the bottom surface is left as it is. It cannot be used as a deflecting surface or a reflecting surface, and it is difficult to flatten by polishing.

Embodiments of an optical scanning device provided with a counter mirror which solves such a problem will be described below as the eleventh to twelfth embodiments. The eleventh to twelfth embodiments are used for a part for forming a mirror unit and a reflection surface in the optical scanning module in the first and second embodiments.
It can be used in other configurations.

FIG. 24 shows a front view and a sectional view of an optical scanning device according to an eleventh embodiment of the present invention.

On the first silicon substrate 1801, which is the deflecting means of the optical scanning device of the present invention, there are formed two torsion beams 1803 integrally formed with the silicon frame 1802 and the mirror portion 1804 supported thereby. On the mirror surface, a metal thin film is formed as a deflection surface 1805. In the first silicon substrate 1801,
Parts related to the driving means are not shown in the figure. As described above, an electromagnetic force or an electrostatic attractive force can be used as a driving means of the mirror unit. In the former case, a mirror unit supported by two beams is installed in a magnetic field, and the mirror unit is driven. The mirror section is reciprocally oscillated by an electromagnetic force generated by applying a current to the coil formed in the mirror section. In the latter case, two electrodes are provided with a gap at opposing positions on the back of the mirror section supported by two beams, and an electrostatic attractive force generated by applying a voltage between the mirror section and the opposing electrode is generated. To reciprocate the mirror. At this time, by designing the structure and dimensions of the torsion beam and the mirror so that the driving frequency becomes the resonance frequency of the mirror section, the deflection width of the mirror can be increased.

The second embodiment of the optical scanning device according to the eleventh embodiment
The silicon substrate 1806 is provided with a reflection surface 1807 on which a metal thin film is formed for multiple reflection. Further, as shown in the front view of the optical scanning device in FIG. 24, the first silicon substrate 1806
An opening 1808 for inputting laser light to the deflection surface 1805 of the 801 and an opening 1809 for emitting laser light from the deflection surface after multiple reflection are formed. The entrance opening 1808 only needs to be wide enough to allow the laser beam to enter, but the exit opening 1809 does not obstruct the laser beam because the laser beam is scanned and emitted over a wide area by the vibration of the deflecting surface. In particular, it is necessary to make the width sufficiently large in the scanning direction side of the laser light (in a direction substantially orthogonal to the traveling direction of the laser light). It suffices that the width of the laser light in the traveling direction is considered in consideration of the width of the spread of the laser light.

Between the first silicon substrate 1801 provided with the deflecting surface 1804 and the second silicon substrate 1806 provided with the reflecting surface 1807, a third defining the distance between the deflecting surface 1804 and the reflecting surface 1807. A glass substrate 1810 is provided. This 100 um thick glass substrate
The first silicon substrate 1801 is joined on the frame 1802, and the movable portion inside the frame, that is, two torsion beams 1803 and the mirror portion 180 supported thereby.
4 is penetrated. Therefore, the thickness of 100 μm of the third glass substrate directly defines the distance between the deflection surface 1804 and the reflection surface 1807.

Opening 18 of second silicon substrate 1806
In FIG. 24, the laser beam incident on the first silicon substrate 1801 and deflected and scanned by the reciprocatingly oscillating mirror portion surface 1805 formed on the first silicon substrate 1801,
After reciprocating four times with a reflection surface of a second silicon substrate provided at an interval of 0 μm, the light is emitted through an opening 1809 of the second silicon substrate. At this time, since the dimensions of the reflection surface provided from the entrance opening to the exit opening and the distance from the reflection surface to the surface of the deflecting mirror unit are accurately defined, the rotation angle (deflection angle) of the mirror unit is reduced. 3 °
Then, four reflections are obtained, and the scanning angle is enlarged to 24 °.

A method for manufacturing the optical scanning device according to the present invention will be described with reference to FIG. First, a 1.5 μm thick SiO 2 film 1902 was formed on both sides of a 525 μm thick double-side polished silicon wafer 1901 as a silicon etching mask.
Is formed by a thermal oxidation method (a). Here, SiO2 is used as a mask material, but other thin film materials that are not etched by a silicon etchant, such as a SiN film,
A SiN / SiO2 bilayer film or the like may be used. This Si
One side of the O2 film is patterned by etching with a buffer solution of hydrofluoric acid using a resist as a mask so as to form an entrance opening and an exit opening (b). Next, using the SiO2 film as an etching mask, the silicon wafer is etched using an anisotropic etching solution until the silicon wafer reaches the SiO2 film on the back surface (c). Although a KOH solution was used here as an anisotropic etching solution, silicon and Si
Other anisotropic etchants having a sufficiently high etching selectivity of O2, such as TMAH and hydrazine, may be used. Next, both surfaces of the SiO2 film used as the etching mask are removed by etching with hydrofluoric acid (d).

The second silicon substrate thus manufactured is bonded to a 1 mm-thick glass substrate 1903 serving as a third substrate for defining the distance between the deflecting surface and the reflecting surface (e). At this time, borosilicate glass is used as the glass substrate, and the bonding method can be anodic bonding. Anodic bonding is a method in which a glass substrate and a silicon substrate are heated to 400 to 500 ° C. and a voltage of several hundred volts is applied between the two substrates to directly bond the substrates. According to this method, since the two substrates can be joined without any intervening material such as an adhesive, the distance between the deflecting surface and the reflecting surface after assembling the optical deflecting device can be accurately defined.

Next, the glass substrate was subjected to CMP (Chemical Mech).
The thickness is reduced to 100 μm by highly accurate polishing using anical polishing (f). The thickness at this time is the distance between the deflection surface and the reflection surface.

Next, Au 1904 as an electrode for plating is formed on the glass substrate 1903 by sputtering (g), and the area is limited by patterning a resist 1905 (h). Then, a 1 μm thick Ni film 19 is formed on the glass substrate 1903.
06 is formed by electrolytic plating (i). Although 1 μm thick Ni is formed by electrolytic plating here, another method may be used as long as a thick mask material can be efficiently formed. Next, after the resist 1905 is removed (j), the glass substrate is dry-etched using Ni as a mask until the glass substrate reaches the silicon substrate serving as the reflection surface, and the glass layer remaining at the end is removed by etching with hydrofluoric acid ( k). The reason why the etching when reaching the silicon substrate is wet etching is to secure the flatness of the reflection surface by increasing the etching selectivity with silicon. Next, Ni and Au used as masks are removed by etching with respective etching liquids (l). Al1907 is formed as a laser reflecting material on the flat silicon surface thus formed by a mask sputtering method (m). Here, Al was formed as a metal thin film by a sputtering method, but other materials such as Au can be selected as long as the metal thin film can provide a necessary and sufficient reflectance to a laser beam to be used. Not only the method but also a vacuum deposition method can be used. In the above steps, the third glass substrate that defines the distance between the deflection surface and the reflection surface is joined,
A second aperture formed with an entrance aperture, an exit aperture, and a reflective surface;
Is completed.

In this embodiment, the first silicon substrate 190
As the deflection means for repeatedly scanning the laser light of No. 8,
A mirror supported by two beams and reciprocatingly oscillated by the torsion is used. This mirror can be formed by thinning a part of a silicon substrate by anisotropic etching and penetrating the part in a desired shape by dry etching. The driving method may be an electromagnetic force or an electrostatic attractive force. In the former case, an electromagnetic force is generated by installing a mirror portion supported by two beams in a magnetic field and flowing a current through a coil formed on the back surface of the mirror portion. The mirror is reciprocated by force. In the latter case, two electrodes are provided with a gap at opposing positions on the back of the mirror section supported by two beams, and an electrostatic attractive force generated by applying a voltage between the mirror section and the opposing electrode is generated. To reciprocate the mirror. In any case, the deflection surface is formed on the polished flat surface side of the silicon substrate, and the surface of the frame for fixing the two beams is also flat and in the same plane as the mirror surface. Since the manufacturing process of the first silicon substrate follows the existing technology and is not a main part of the present invention, a detailed description is omitted.

Anodically bonding the torsionally vibrating mirror, ie, the first silicon substrate provided with the deflection surface, to the second silicon substrate provided with the reflection surface via a third glass substrate (n) . Also in this case, since the two substrates are joined without any inclusion such as an adhesive, the distance between the deflecting surface and the reflecting surface after assembling the optical deflecting device can be accurately defined by the thickness of the glass substrate.

FIG. 26 is a sectional view of an optical scanning device according to the twelfth embodiment of the present invention.

On the first silicon substrate 2001, which is the deflecting means of the optical scanning device of the present invention, there are formed two torsion beams 2003 integrally formed with the silicon frame 2002 and a mirror portion 2004 supported thereby. On the mirror surface, a metal thin film is formed as a deflection surface 2005. The portion of the first silicon substrate related to the driving means is not shown in the drawing.

As in the eleventh embodiment, an electromagnetic force or an electrostatic attraction can be used as the mirror driving means. In the former case, the mirror supported by two beams is installed in a magnetic field. Then, the mirror portion is reciprocally oscillated by an electromagnetic force generated by passing a current through a coil formed in the mirror portion. In the latter case, two electrodes are provided with a gap at opposing positions on the back of the mirror section supported by two beams, and an electrostatic attractive force generated by applying a voltage between the mirror section and the opposing electrode is generated. To reciprocate the mirror. At this time, by designing the structure and dimensions of the torsion beam and the mirror so that the driving frequency becomes the resonance frequency of the mirror section, the deflection width of the mirror can be increased.

The second embodiment of the optical scanning device according to the twelfth embodiment
The silicon substrate 2006 is provided with a reflection surface 2007 on which a metal thin film is formed for multiple reflection. Further, as shown in the front view of the optical scanning device in FIG. 24, the first silicon substrate 2
An opening 2008 for entering a laser beam into the deflecting surface 2005 and an opening 2009 for emitting a laser beam from the deflecting surface after multiple reflection are formed. The entrance opening 2008 only needs to be wide enough to allow laser light to enter, but the exit opening 2009 does not obstruct the laser light because the laser light is scanned and emitted over a wide area by the vibration of the deflecting surface. In particular, it is necessary to make the width sufficiently large in the scanning direction side of the laser light (in a direction substantially orthogonal to the traveling direction of the laser light). It suffices that the width of the laser light in the traveling direction is considered in consideration of the width of the spread of the laser light.

A first silicon substrate 2001 provided with a deflection surface 2005 and a second silicon substrate 2006 provided with a reflection surface 2007 are formed by a third silicon substrate 2010 provided outside the first silicon substrate. The distance between the deflection surface 2005 and the reflection surface 2007 is defined.
The 300 μm-thick silicon substrate 2010 is the same glass support substrate 2011 as the first silicon substrate 2001.
Are joined on top. Therefore, the distance between the deflecting surface 2005 and the reflecting surface 2007 is defined by the thickness 300 μm of the third glass substrate 2010 and the thickness of the first silicon substrate.

Opening 20 of second silicon substrate 2006
08, the laser beam deflected and scanned by the reciprocatingly oscillating mirror portion surface 2005 formed on the first silicon substrate 2001 has a thickness of 100 μm as shown in FIG.
After reciprocating four times with the reflecting surface of the second silicon substrate provided oppositely with an interval of, the light is emitted through the opening 2009 of the second silicon substrate. At that time, the dimensions of the reflection surface provided from the entrance opening to the exit opening,
Since the distance from the reflecting surface to the surface of the deflecting mirror section is accurately specified, four reflections are obtained when the rotation angle (deflection angle) of the mirror section is 3 °, and the scanning angle is enlarged to 24 °. You.

A method for manufacturing the optical scanning device according to the twelfth embodiment will be described with reference to FIG. First, a 1.5 μm thick SiO 2 film 2102 is formed as a silicon etching mask on both surfaces of a 525 μm thick double-side polished silicon wafer 2101 by thermal oxidation (a). Here, SiO
2 is used as a mask material, but is not etched by a silicon etchant.
An iN film, a SiN / SiO 2 bilayer film, or the like may be used.
One side of this SiO2 film is patterned by etching with a buffer solution of hydrofluoric acid using a resist as a mask so that an entrance opening and an exit opening are formed (b). Next, using the SiO2 film as an etching mask, a silicon wafer
Etch until reaching the film (c). Although the KOH solution is used here as the anisotropic etchant, another anisotropic etchant having a sufficiently high etching selectivity between silicon and SiO2, such as TMAH or hydrazine, may be used. Next, Si used as an etching mask
Both surfaces of the O2 film are removed by etching with hydrofluoric acid (d).

The second silicon substrate fabricated in this manner is then replaced with a 525 μm-thick silicon substrate with a thermal oxide film serving as a third substrate for defining the distance between the deflection surface and the reflection surface.
(E). The joining method at this time was direct joining. Direct bonding is a method of directly bonding silicon substrates whose surfaces have been cleaned to 900 to 1100 ° C. by heating. According to this method, since the two substrates can be joined without any intervening material such as an adhesive, the distance between the deflecting surface and the reflecting surface after assembling the optical deflecting device can be accurately defined. Next, the silicon substrate is subjected to CMP (Chemical Mechanical Polishing).
The thickness is reduced to 300 μm by polishing with high precision (f). The difference between the thickness at this time and the thickness of the first silicon substrate is the distance between the deflection surface and the reflection surface.

Next, S is applied to the entire bonded substrate by a thermal oxidation method.
An iO2 film 2104 is formed (g), and the SiO2 film of the third silicon substrate is etched with a buffer solution of hydrofluoric acid using a resist as a mask so that an opening for accommodating the second silicon substrate is formed. (H). Next, using the SiO2 film as an etching mask, the silicon wafer is etched with an anisotropic etching solution until the silicon wafer reaches the SiO2 film at the bonding interface (i). Although the KOH solution is used here as the anisotropic etchant, another anisotropic etchant having a sufficiently high etching selectivity between silicon and SiO2, such as TMAH or hydrazine, may be used.

Next, S used as an etching mask
Both sides of the iO2 film are removed by etching with hydrofluoric acid (j). On the silicon flat surface of the second substrate thus formed, Al was formed as a laser reflection material by a mask sputtering method (k). Here, Al was formed as a metal thin film by a sputtering method, but other materials such as Au can be selected as long as the metal thin film can provide a necessary and sufficient reflectance to a laser beam to be used. Not only the method but also a vacuum deposition method can be used. Through the above steps, the second silicon substrate having the entrance opening, the exit opening, and the reflection surface formed thereon, to which the third silicon substrate defining the distance between the deflection surface and the reflection surface is joined.

As a deflecting means for repeatedly scanning the laser beam on the first silicon substrate, a mirror supported by two beams and reciprocatingly vibrating by its torsion was used. This mirror can be formed by thinning a part of a silicon substrate by anisotropic etching and penetrating the part in a desired shape by dry etching. The driving method may be an electromagnetic force or an electrostatic attractive force. In the former case, an electromagnetic force is generated by installing a mirror portion supported by two beams in a magnetic field and flowing a current through a coil formed on the back surface of the mirror portion. The mirror is reciprocated by force. In the latter case, two electrodes are provided with a gap at opposing positions on the back of the mirror section supported by two beams, and an electrostatic attractive force generated by applying a voltage between the mirror section and the opposing electrode is generated. To reciprocate the mirror. In any case, the deflection surface is formed on the polished flat surface side of the silicon substrate, and the surface of the frame for fixing the two beams is also flat and in the same plane as the mirror surface. Since the manufacturing process of the first silicon substrate follows the existing technology and is not a main part of the present invention, a detailed description is omitted.

The torsionally vibrating mirror, that is, the first silicon substrate 2106 provided with the deflecting surface is anodically bonded to the glass substrate 2107 serving as the reference surface (l). Anodically bonded to a glass substrate serving as the same reference plane via a silicon substrate (m). In any case, since the substrates are bonded without any inclusions such as an adhesive, the distance between the deflecting surface and the reflecting surface after assembling the optical deflector is accurately defined by the difference in thickness between the first silicon substrate and the third silicon substrate. can do.

As described above, the present invention has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and can be variously changed without departing from the gist of the present invention.

[0184]

As described above, according to the present invention, it is possible to realize a compact module as an optical scanning device and to improve the production efficiency by simplifying the manufacturing process. In addition, by reducing the size and weight of the movable part of the deflector and reducing the load, power consumption can be reduced, and an electrostatically driven torsional vibration deflector that provides a large deflection angle and stable vibration can be obtained. It is possible to provide an optical scanning device having the same.

That is, by arranging the light source unit substrates in a stacked manner as shown in FIG. 3, the light beam can be made incident on the deflecting surface with high accuracy, while a larger scanning angle can be obtained with a small rotation angle of the deflector. As the speed of the deflector can be reduced, the moving parts can be made thinner, the processing time can be shortened, the assembly efficiency can be improved, and the arrangement accuracy of the reflecting surface and the deflecting surface can be achieved by laminating without troublesome adjustment work. Can be secured, so that the assembly efficiency can be improved.

In the mirror deflector, a substrate surface opposite to a surface of the mirror substrate opposite to the mirror surface is provided;
By providing electrodes on the end face of the frame facing the end face of the mirror substrate, the mirror substrate can be excited with a low voltage because the end face of the mirror substrate and the electrode formed on the surface of the inner frame of the frame facing the end face are close to each other. Furthermore, when driven at the resonance frequency, the deflection width of the mirror substrate increases, and the mirror substrate end portion is close to the electrode surface opposite to the mirror surface having a larger area. The maintenance of the vibration can be further stabilized by driving the opposed electrodes.

Further, the deflecting surface of the deflecting unit substrate and the reflecting surface of the light source unit substrate are formed on the respective substrate surfaces, and the distance between the two is specified by another substrate. A polished substrate surface is available.

[Brief description of the drawings]

FIG. 1 is a configuration example of an optical scanning device according to a conventional technique (an example using a polygon mirror).

FIG. 2 is a configuration example of an optical scanning device according to a conventional technique (an example using a galvanometer mirror).

FIG. 3 is a perspective view of the optical scanning module according to the first embodiment of the present invention.

FIG. 4 is a sectional view of the optical scanning module according to the first embodiment of the present invention.

FIG. 5 is a perspective view of an optical scanning module according to a second embodiment of the present invention.

FIG. 6 is a sectional view of an optical scanning module according to a second embodiment of the present invention.

FIG. 7 is a diagram showing an optical scanning device including the optical scanning module of the present invention.

FIG. 8 is a configuration diagram of a digital copying machine.

FIG. 9 is a configuration diagram of a laser printer.

FIG. 10 is a configuration diagram of a plain paper facsimile.

FIG. 11 is a configuration diagram of an optical scanning device according to a third embodiment of the present invention.

FIG. 12 is a diagram illustrating a method of manufacturing the optical scanning device according to the third embodiment of the present invention.

FIG. 13 is a sectional view of an optical scanning device according to a fourth embodiment of the present invention.

FIG. 14 is a view illustrating a method of manufacturing the optical scanning device according to the fourth embodiment of the present invention.

FIG. 15 is a diagram illustrating a configuration of an optical scanning device according to a fifth embodiment of the present invention.

FIG. 16 is a diagram illustrating a configuration of an optical scanning device according to a sixth embodiment of the present invention.

FIG. 17 is a diagram illustrating a method of manufacturing the optical scanning device according to the sixth embodiment of the present invention.

FIG. 18 is a sectional view of an optical scanning device according to a seventh embodiment of the present invention.

FIG. 19 is a sectional view of an optical scanning device according to an eighth embodiment of the present invention.

FIG. 20 is a sectional view of an optical scanning device according to a ninth embodiment of the present invention.

FIG. 21 is a diagram illustrating a configuration of an optical scanning device according to a tenth embodiment of the present invention.

FIG. 22 is a diagram illustrating a connection configuration between a write control unit and an electrode that swings a mirror.

FIG. 23 is a timing chart showing the timing of applying a voltage to each electrode.

FIG. 24 is a front view and a sectional view of an optical scanning device according to an eleventh embodiment of the present invention.

FIG. 25 is a view illustrating a method of manufacturing the optical scanning device according to the eleventh embodiment of the present invention.

FIG. 26 is a sectional view showing an optical scanning device according to a twelfth embodiment of the present invention.

FIG. 27 is a diagram illustrating a method of manufacturing the optical scanning device according to the twelfth embodiment of the present invention.

[Description of Signs] 101: semiconductor laser (LD), 102: holding member, 1
03: coupling lens, 107: polygon mirror,
110: imaging lens, 112: optical base, 115: galvanometer mirror, 201, 301: electrode substrate, 202, 3
02: lead terminal, 203: magnet, 204, 30
3 ... first silicon substrate, 205 ... torsion beam, 206 ...
Mirror part, 207, 308... Second silicon substrate, 20
8, 309: semiconductor laser chip, 209, 310: photodiode, 210, 311: coupling lens, 211, 312: V groove, 212, 313: frame, 213, 316: aperture, 214, 215, 2
16, 314, 315: Reflector, 217, 317: Opening, 218, 318: Sealing plate, 219, 319: Exit window, 220, 221, 320, 321: Control circuit, 30
4 Deflection disk unit, 305 diffraction grating, 307 electrode, 322 stator unit, 323 shaft unit, 325 submount, 402 electric board, 403 synchronization detection sensor, 404 scanning lens, 405 mirror 500 image forming apparatus main body, 501 optical scanning device, 601 mirror substrate, 602, 603 torsion beam, 604 frame inner frame, 605 frame outer frame, 607 insulating material, 606
... Mirror substrate end faces, 608, 609, 614, 615,
714, 715: electrode, 611: mirror, 612, 71
2: electrode substrate, 613: insulating material, 616, 617: terminal, 618: conductive material, 701, 702: silicon substrate, 703 to 707, 709, 713: SiO2 film, 7
08 ... end face, 710 ... Pt thin film, 711 ... metal thin film, 7
16 ... conductive adhesive, 812 ... electrode substrate, 813 ... insulating material, 814, 815, 905, 906 ... electrodes, 81
6, 817 terminal, 818 conductive material, 901 silicon substrate, 902 dry film resist, 903
Dry film resist shape, 904 ... SiO2 film, 1
001: silicon substrate, 1002: frame, 1003
... diaphragm, 1004, 1005 ... opening, 100
6 Mirror surface, 1101 Mirror substrate, 1102, 11
03, 1201, 1202 ... silicon substrate, 1104 ...
Frame inner frame 1105 Frame outer frame 1106 End face 1107 1117 Insulating material 1108 110
9, 1118, 1119, 1216, 1217 ... electrodes,
1111: mirror, 1112: frame, 1113: diaphragm, 1114, 1115: opening, 1116:
Mirror surface, 1120, 1211, ... terminal, 1122, conductive material, 1203, 1205-1209, 1211 ... S
iO2 film, 1210 ... end face, 1212 ... Pt thin film, 12
13: conductive adhesive, 1214: diaphragm, 121
5. Openings, 1301, 1302, 1401 to 140
4, 1501 to 1504 ... electrode, 1601 ... mirror substrate end face, 1602 ... frame inner frame, 1603, 1604 ...
Electrode, 1701 LD, 1703 sensor, 1801
1st silicon substrate, 1802 ... silicon frame, 1
803: torsion beam, 1804: mirror portion, 1805: deflection surface, 1806: second silicon substrate, 1807: reflection surface, 1808, 1809: opening, 1810: third glass substrate, 1901: silicon wafer, 1902 ... Si
O2 film, 1903: glass substrate, 1904: Au, 19
05 resist, 1907 Al, 1908 first silicon substrate, 2001 first silicon substrate, 2002
... Silicon frame, 2003 ... Torsion beam, 2004 ...
Mirror part, 2005: deflection surface, 2006: second silicon substrate, 2007: reflection surface, 2008, 2009 ... opening, 2010: third silicon substrate, 2011: glass support substrate, 2103: silicon substrate with thermal oxide film , 21
04: SiO2, 2106: first silicon substrate, 21
07 ... Glass substrate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshinori Hayashi 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2C362 AA34 AA43 BA17 BA86 BA90 BB29 DA08 EA24 2H041 AA12 AB14 AB15 AC06 AZ01 AZ05 AZ08 2H045 AB02 AB08 AB23 AB73 AD02 BA02 BA23 BA34 CA63 CA88 DA02 5C072 AA03 BA01 HA02 HA14 HB15 XA01 XA05

Claims (28)

[Claims] 1. An optical scanning device module for deflecting and scanning a light beam from a light source, comprising: a deflecting unit having a deflecting surface for deflecting the light beam; and a deflecting unit substrate for supporting the deflecting unit on a rotating shaft. An optical scanning device module, wherein a reflecting surface is provided integrally with the deflecting unit substrate so as to face the deflecting surface, and a light beam is reflected and scanned a plurality of times between the reflecting surface and the deflecting surface. . 2. An optical scanning device module for scanning by deflecting a light beam from a light source, wherein a light source unit substrate on which a light source is mounted and a deflecting unit substrate holding a deflecting unit having a deflecting surface for deflecting the light beam are stacked. An optical scanning device module, comprising: a reflecting surface facing the deflecting surface, and reflecting and scanning a light beam a plurality of times between the reflecting surface and the deflecting surface. 3. The distance between the reflecting surface and the deflecting surface is g,
When the incident angle of the light beam in the sub-scanning direction on the deflecting surface is β and the diameter of the sub-scanning light beam of the incident light beam is 2ω, the relationship represented by g · tan β> ω is satisfied, and the reflection point on the deflecting surface is satisfied. 3. The method according to claim 1, wherein the scanning is performed by sequentially moving the scanning in the sub-scanning direction.
3. The optical scanning device module according to claim 1. 4. The optical scanning device module according to claim 1, wherein an interval between the reflecting surface and the deflecting surface is wider on an exit side than on an incident side of a light beam. 5. The light according to claim 1, wherein a light source unit substrate on which the light source is mounted is stacked on a deflection unit substrate, and the reflection surface is provided on the light source unit substrate. Scanner module. 6. The optical scanning device module according to claim 1, wherein the reflection surface is provided integrally with the light source unit substrate. 7. The optical scanning device module according to claim 1, wherein an aperture for regulating a light beam diameter of a light beam incident on the deflection surface is provided integrally with the reflection surface. 8. The deflecting means uses electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided to face the mirror substrate. Means for reciprocatingly oscillating the mirror substrate using the beam as a torsion rotation axis, wherein electrodes are provided on a substrate surface facing the surface of the mirror substrate opposite to the mirror surface and a frame end surface facing the mirror substrate end surface. Item 3. The optical scanning device module according to item 1 or 2. 9. A frame is provided on the mirror surface side of the mirror substrate, the frame has an opening through which a light beam incident on the mirror substrate passes, an opening through which a light beam deflected by the mirror substrate passes, and a mirror surface. The optical scanning device module according to claim 8, further comprising a reflection surface facing the light scanning device. 10. The deflecting means includes: two deflecting means, each of which is provided by an electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided opposite to the mirror substrate. Means for reciprocatingly oscillating the mirror substrate using the beam as a torsion rotation axis, a frame is provided on the mirror surface side of the mirror substrate, and the frame has an opening through which a light beam incident on the mirror substrate passes; 3. The optical scanning device according to claim 1, further comprising an opening through which the deflected light beam passes, a reflecting surface facing the mirror surface, and an electrode facing the mirror surface, wherein the electrode is located at a position facing the mirror substrate end surface. Equipment module. 11. An optical scanning device module according to claim 1, further comprising: a synchronization detection sensor for detecting a light beam on a scanning start side and a scanning end side; and a scanning lens. Optical scanning device. 12. An optical scanning device comprising: an image carrier; and the optical scanning device module according to claim 1, which is juxtaposed in the main scanning direction of the image carrier. . 13. An image forming apparatus comprising the optical scanning device according to claim 11. 14. The two beams are torsionally rotated by an electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided facing the mirror substrate. An optical scanning device module for reciprocatingly oscillating a mirror substrate, comprising: an electrode on a substrate surface opposite to a surface of the mirror substrate opposite to the mirror surface; and an electrode on a frame end surface opposite to the mirror substrate end surface. Equipment module. 15. The optical scanning device module according to claim 14, wherein the electrodes on the substrate surface facing the surface of the mirror substrate opposite to the mirror surface are inclined about the torsional rotation axis. 16. A frame is provided on a mirror surface side of a mirror substrate. The frame has an opening through which a light beam incident on the mirror substrate passes, an opening through which a light beam deflected by the mirror substrate passes, and a mirror surface. The optical scanning device module according to claim 14, further comprising an opposing reflecting surface. 17. The two beams are torsionally rotated by an electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided opposite to the mirror substrate. In the optical scanning device module for reciprocatingly oscillating the mirror substrate, a frame is provided on the mirror surface side of the mirror substrate, and the frame has an opening through which a light beam incident on the mirror substrate passes;
An optical scanning device comprising: an opening through which a light beam deflected by a mirror substrate passes; a reflection surface facing the mirror surface; and an electrode facing the mirror surface, and having an electrode at a position facing the mirror substrate end surface. Equipment module. 18. The optical scanning device module according to claim 14, wherein the electrode facing the mirror substrate end surface is formed at a portion that does not overlap with the mirror substrate end surface. 19. The optical scanning device module according to claim 14, wherein an end surface of the mirror substrate and the electrode facing the mirror substrate have a comb shape. 20. An electrode provided to face an end surface of a mirror substrate and an electrode provided on a surface opposite to the mirror surface or an electrode provided on a surface opposite to the mirror surface are not electrically connected. The optical scanning device module according to any one of claims 14 to 17, wherein the optical scanning device module is driven by shifting a timing of applying a voltage to the electrode. 21. An electrode is provided on each of a surface of the mirror substrate facing the mirror surface, a surface of the mirror substrate opposite to the mirror surface, and a surface of the mirror substrate opposite to the mirror substrate end surface. 17. The optical scanning device module according to claim 16, wherein the optical scanning device module is driven by shifting the timing of applying a voltage to the electrodes. 22. Any one of claims 14 to 21.
13. The optical scanning device module according to claim 12, wherein the optical scanning device module is provided in a decompression container through which light can pass and electrodes can be taken out. 23. A first substrate provided with a deflecting means for reflecting and scanning a light beam on a deflecting surface, a second substrate provided with a reflecting surface at a position facing the deflecting surface, and An optical scanning device module, comprising: a third substrate for defining a distance from the reflection surface; and scanning by reflecting laser light a plurality of times between the deflection surface and the reflection surface. 24. Any one of claims 14 to 23
13. An optical scanning device, comprising: the optical scanning device module according to any one of the above items, a synchronization detection sensor that detects a light beam on the scanning start side and the scanning end side, and a scanning lens. 25. An optical scanning device comprising: an image carrier; and the optical scanning device module according to claim 14, which is juxtaposed in the main scanning direction of the image carrier. . 26. One of claims 24 and 25
An image forming apparatus comprising the optical scanning device according to any one of the preceding items. 27. A light source unit substrate on which a light source is mounted and a deflecting unit substrate holding a deflecting unit having a deflecting surface for deflecting a light beam are stacked and provided, and a reflecting surface is provided opposite to the deflecting surface. A method of controlling a deflecting unit in an optical scanning device module that reflects and scans a light beam a plurality of times between a reflecting surface and the deflecting surface, comprising: applying a voltage to a first electrode facing an end surface of a mirror substrate; Subsequently, a voltage is applied to the first electrode facing the mirror surface or the first electrode facing the opposite side of the mirror surface, and after the voltage is released, the voltage is applied to the second electrode facing the end surface of the mirror substrate. To the second mirror facing the mirror surface.
A voltage is applied to the first electrode or the second electrode facing the opposite side of the mirror surface. 28. The two beams are torsionally rotated by an electrostatic attraction between a mirror substrate supported by two beams provided on the same straight line and an electrode provided opposite to the mirror substrate. A method for controlling an optical scanning device module for reciprocatingly oscillating a mirror substrate, comprising: applying a voltage to a first electrode facing an end surface of the mirror substrate, and subsequently applying a voltage to the first electrode facing the mirror surface or opposite to the mirror surface. A voltage is applied to the first electrode facing the side, and after the voltage is released, a voltage is applied to the second electrode facing the end surface of the mirror substrate, and the second electrode facing the mirror surface continues.
A voltage is applied to the first electrode or the second electrode facing the opposite side of the mirror surface.