JP2009020219A - Oscillating-body device and optical deflector using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oscillating-body device stabilizing the oscillating movement of a needle by regulating an air flow generated by the oscillating movement of the needle and suppressing its turbulence. <P>SOLUTION: This oscillating-body device is provided with at least one needle 101 or 102 supported to oscillate around a rotation axis 111. At least a part of the needle 101 or 102 has a semicylindrical, hemispherical or spherical air flow regulator 106. The surface of the air flow regulator 106 has a curved shape in respective cross sections perpendicular to the rotation axis 111. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an oscillator device having at least one mover supported so as to be able to swing, an optical deflector using the same, an optical apparatus using the same, and the like. The oscillator device can be applied as an optical deflector, an actuator, a sensor, or the like. The optical deflector is preferably used for an image forming apparatus such as a projection display that projects an image by deflecting scanning of light, a laser beam printer having an electrophotographic process, a digital copying machine, or the like.

Conventionally, an optical scanning system or an optical scanning device using an optical deflector including a mover that performs sinusoidal vibration has been proposed. The optical scanning system using the optical deflector that performs sinusoidal vibration can significantly reduce the size of the optical deflector compared to the optical scanning system that uses a rotating polygon mirror such as a polygon mirror. In addition, the optical deflector made of a Si single crystal manufactured by a semiconductor process has features such as low power consumption and theoretically no metal fatigue and excellent durability.

In an optical deflector using a resonance phenomenon, there is a technique for performing optical scanning other than sinusoidal optical scanning by simultaneously exciting two or more natural vibration modes in the torsional vibration direction (see Patent Document 1). FIG. 6 is a top view for explaining the optical deflector. A flat movable portion (first movable element) 1001 is supported by two torsion springs 1011a and 1011b in the upper and lower directions in the drawing, and has a permanent magnet 1041. A frame-shaped movable portion (second movable element) 1002 supports torsion springs 1011a and 1011b on the inside thereof, and is supported by two torsion springs 1012a and 1012b in the upper and lower directions in the figure. A frame-shaped support frame 1021 supports torsion springs 1012a and 1012b on the inside thereof. The support frame 1021 is bonded to the plate member 1000. The movable parts 1001 and 1002 and the torsion springs 1011 and 1012 have two natural vibration modes, and their frequency ratio is in a relationship of approximately 1: 2. By simultaneously exciting these two modes, it is possible to drive the optical deflector with sawtooth vibration and perform optical scanning with little fluctuation in angular velocity. However, the optical deflector shown in FIG. 6 does not particularly take into consideration the turbulence of the air current generated in the vicinity of the movable part when the movable part is swung with a large deflection angle.

On the other hand, as an optical deflector that stabilizes the displacement angle and swinging motion of the mover, there is an optical deflector as shown in FIG. 7 that is an exploded view (see Patent Document 2). In FIG. 7, the optical deflector 1 includes a vibrating body 5, a base 2 and a lid 20. The vibrating body 5 includes a reflecting mirror (movable element) 8, torsion springs 9 and 10 connected to the reflecting mirror 8, and a fixed frame portion 7 to which the torsion springs 9 and 10 are connected. The base 2 includes support portions 3 and 4, recesses 2 a and 2 b formed on the upper surface between the support portions 3 and 4, and electrodes 11 and 12 on the recess 2 a for vibrating the torsion spring 10. . The lid 20 that holds the vibrating body 5 is formed of a material that transmits a deflected light beam (not shown).

In such an optical deflector, when the reflection mirror 8 vibrates and is torsionally displaced, the stress generated at the connection point between the torsion springs 9 and 10 and the fixed frame portion 7 can be dispersed. At the same time, the stress can be distributed to the torsion spring 10 without concentrating the stress only on the torsion spring 9. Therefore, the torsion springs 9 and 10 need not be made too thick or long, and a relatively large displacement angle (runout angle) can be obtained with a compact design while ensuring the resonance frequency of the reflection mirror 8. Further, the airflow turbulence can be reduced by sealing with the lid 20 and then reducing the pressure therein or filling with an inert gas. Thus, the swinging motion of the vibrating body can be stabilized.
JP 2005-208578 A Japanese Patent Laid-Open No. 2003-057586

For example, in electrophotography such as a laser beam printer, an image is formed by scanning laser light on a photoconductor. When scanning with a large displacement angle using an optical deflector as shown in FIG. 6 as an optical deflector in such an apparatus, it is not considered to stabilize the moving motion of the mover by reducing the turbulence of the air flow and the like. It is.

On the other hand, in the case of the optical deflector shown in FIG. 7, it is said that the turbulence of the airflow can be reduced and the displacement angle and the swing motion can be stabilized by reducing the pressure or filling with an inert gas. However, packaging for reduced pressure or filling with inert gas tends to increase manufacturing costs. In addition, since the lid is formed of a material through which the light beam deflected and scanned by the reflecting mirror surface is transmitted, it is inevitable that the light amount of the light beam is reduced to some extent.

In view of the above problems, the oscillator device of the present invention is an oscillator device including at least one mover supported so as to be able to swing around a rotating shaft, and has the following characteristics. That is, an airflow adjusting body is provided on at least a part of the mover, and the surface of the airflow adjusting body has a curved shape in each cross section perpendicular to the rotation axis.

Further, in view of the above problems, the optical apparatus of the present invention includes a light source, a movable member provided with a reflecting surface, and a swinging unit including a driving unit that swings the movable member by applying torque to at least one movable member. It has the optical deflector comprised by the apparatus, and a light-incidence target body, It is characterized by the above-mentioned. The light deflector deflects light from the light source and causes at least a part of the light to enter the light incident target body.

According to the present invention, the airflow adjusting body having the surface as described above is provided on at least one movable element, and the airflow generated by the swinging motion of the movable element can be adjusted to suppress the disturbance. Therefore, even when the displacement angle of the mover is relatively large, the swinging motion of the mover is stabilized. Therefore, when the oscillator device of the present invention is used as, for example, an optical deflector, stable optical scanning can be performed without reducing the amount of light of the scanning light beam.

Hereinafter, examples will be described in order to clarify specific embodiments of the present invention.

(First embodiment)
The optical deflector according to the first embodiment of the oscillator device of the present invention will be described with reference to FIGS. 1-1, 1-2, and 3. FIG. FIG. 1-1A is a top view of the optical deflector of the present embodiment. FIG. 1-1 (b) is a cross-sectional view taken along the line 1A-1A ′ of FIG. 1-1 (a). FIG. 1-2 is a cross-sectional view taken along the line 1B-1B ′ of FIG. 1-1 (a). As shown in FIG. 1-1, the optical deflector of the present embodiment has a first movable element 101, a second movable element 102, and a straight line (torsion shaft 111) that connects the two movable elements 101 and 102 in series. Have two types of torsion springs 103 and 104. The first movable element 101 is supported by a first torsion spring 103. The second movable element 102 supports the first torsion spring 103 and is supported by the second torsion spring 104. The support body 105 supports the second torsion spring 104. Thus, the first movable element and the second movable element are supported by the torsion spring so as to be capable of torsional vibration about the same torsion axis that is the rotation axis.

The first mover 101 includes a reflecting surface 114 and a silicon part 113. The material of the reflecting surface 114 is aluminum, for example, and can be formed by vacuum deposition. A protective film may be formed on the outermost surface of the reflective surface 114. The second mover 102 has a silicon portion 112 and two hard magnetic bodies 107. The upper and lower surfaces of the silicon part 112 and the two hard magnetic bodies 107 are bonded to each other with an adhesive.

Further, two air flow adjusting bodies 106 are provided in contact with both surfaces of the silicon portion 112 of the second movable element 102 to which the hard magnetic body 107 is bonded. Each air flow adjusting body 106 has a bowl shape or a semi-cylindrical shape extending in a direction parallel to the torsion shaft 111. The material of the airflow adjusting body 106 is, for example, resin, and is bonded to the silicon portion 112 and the hard magnetic body 107 with an adhesive. In the illustrated example, the air flow adjusting body 106 is in contact with both the silicon portion 112 and the hard magnetic body 107, but when installed on the silicon portion 112, an arch shape in which a portion around the hard magnetic body 107 is hollow. In other words, the hard magnetic body 107 may not be in contact. In this case, both ends in the direction parallel to the torsion shaft 111 of the hollow portion of the airflow adjusting body may be opened as they are, or may be closed. Such a form contributes to reducing the weight of the second movable element 102.

The air flow adjusting body 106 having the above-described shape has a smooth curved shape on the surface in contact with the silicon portion 112, that is, the side opposite to the side having the rotation axis, in each cross section perpendicular to the torsion axis 111 that is the rotation axis. Therefore, when the second mover 102 is swung, the airflow in the vicinity of the second mover is adjusted and the disturbance is greatly reduced, and the vibration system including the first mover 101 and the second mover 102 is swung. Can stabilize movement. The curve shape may be any shape that does not change the differential coefficient of any portion discontinuously, and may include a linear portion. The shape of the airflow adjusting body is, for example, a bowl shape, a semi-cylindrical shape, a semi-elliptical sphere shape, or a hemispherical shape. In this embodiment, the airflow adjusting body is provided only on the second movable element 102, but it can also be provided on the surface of the first movable element 101 that does not have a reflecting surface. Thereby, the turbulence of the air current in the vicinity of the first mover due to the swing of the first mover 101 can be reduced, and the swing motion of the entire vibration system can be further stabilized. In short, it is a feature of the present invention that the airflow adjusting body is provided on at least a part of the mover included in the apparatus. The same applies to other embodiments described later.

The silicon portion 113 of the first mover 101 has a length in the direction perpendicular to the torsion axis 111, for example, 3 mm, and a length in the direction parallel to the torsion axis 111, for example, 1 mm. The silicon portion 112 of the second mover 102 has a length in the direction perpendicular to the torsion axis 111, for example, 2.8 mm, and a length in the parallel direction, for example, 1.5 mm. The support 105, the second torsion spring 104, the silicon portion 112 of the second mover 102, the first torsion spring 103, and the silicon portion 113 of the first mover 101 can be integrally formed. For example, it can be integrally formed from a single crystal silicon substrate by photolithography and dry etching of a semiconductor manufacturing method. This makes it possible to form a small optical deflector with high processing accuracy.

In addition, a coil 108 is disposed below a permanent magnet that is a hard magnetic body 107 that is bonded to each of both surfaces of the second movable element 102. The coil 108 is provided on a substrate 110 that supports a support 105 via a spacer 109. Here, a core (not shown) made of a material with high magnetic permeability may be disposed in the central gap of the coil 108. The substrate 110 and the coil 108 are bonded. The permanent magnet, which is the hard magnetic body 107, and the coil 108 constitute drive means, and when a current is passed through the coil 108, torque acts on the hard magnetic body 107 on the second mover 102, and the vibration system includes a plurality of movers. The whole is driven.

The driving principle of this embodiment will be described. The optical deflector of the present embodiment relates to the torsional vibration centered on the torsion shaft 111, the primary natural vibration mode having the frequency f _{0 as} the reference frequency and the secondary natural vibration mode having a frequency twice the reference frequency. It can be handled as a two-degree-of-freedom vibration system. The coil 108 of the driving means drives the optical deflector of the present embodiment at two frequencies, the frequency of the primary natural vibration mode and the double frequency in the same phase.

FIG. 2A is a diagram for explaining the displacement angle of the torsional vibration of the first mover 101 at the frequency f _{0 with} the horizontal axis as time t. FIG. 2 (a) shows a portion corresponding to one cycle T ₀ of the torsional oscillation of the first movable element _{101 (-T 0/2 <t} <T 0/2).

A curve 61 shows a component of the reference frequency f _{0 in} the vibration caused by the drive signal applied to the coil 108. The curve 61 reciprocates in the range of the maximum amplitude ± φ ₁ , and the time t and the angular frequency w ₀ = 2πf ₀ are set. This is a sine vibration represented by the following formula 1.
θ ₁ = φ ₁ sin [w ₀ t] (Formula 1)

On the other hand, the curve 62 shows the double frequency component of the reference frequency f _0, and oscillates in the range of the maximum amplitude ± phi _2, a sinusoidal vibration is expressed by the following equation 2.
θ ₂ = φ ₂ sin [2w ₀ t] (Formula 2)

A curve 63 indicates a displacement angle of torsional vibration of the first mover 101 resulting from such driving. As described above, the vibration system including the mover can be treated as a two-degree-of-freedom vibration system with respect to torsional vibration, and the natural vibration mode of the reference frequency f ₀ and the second-order natural vibration mode of the frequency 2f ₀ are centered on the torsion shaft 111. It has about torsional vibration. Therefore, in the optical deflector of the present embodiment, resonances of the above θ ₁ and θ ₂ excited by the drive signal respectively occur. That is, the displacement angle of the first mover 101 on the curve 63 is a vibration of superposition of two sinusoidal vibrations and a sawtooth vibration represented by the following Expression 3.
θ = θ ₁ + θ ₂ = φ ₁ sin [w ₀ t] + φ ₂ sin [2w ₀ t] (Formula 3)

FIG. 2B shows curves 61a, 63a and a straight line 64a obtained by differentiating the curves 61 and 63 and the straight line 64 shown in FIG. 2A, and the angular velocities of these curves are explained. Compared with the curve 61a which depicts the angular speed of sinusoidal oscillation of the reference frequency f _0, the curve 63a that indicates the angular velocity of the reciprocating vibration of the sawtooth mover, are in the following manner. That is, in the section NN ′, the angular velocities are within a range in which the angular velocity V _{1 at the} maximum point and the angular velocity V ₂ at the minimum point are maximized and minimized. Therefore, in the application using the deflection scanning of light by the optical deflector of the present embodiment, if V ₁ and V ₂ exist within the allowable error of the angular velocity from the straight line 64a which is the equiangular velocity scanning, the section NN 'Can be regarded as a substantial equiangular scan. In this way, the angular velocity of the deflection scan can be set wider by the sawtooth reciprocal vibration than when the displacement angle is a sine wave. The available area for can be increased.

In the above description, the relationship in which the frequencies of the two natural vibration modes are approximately doubled has been described, but when this is approximately tripled, the shape of the superimposed vibration is substantially a triangular wave. In this case, since a region having a substantially constant angular velocity appears in the reciprocation of the deflection scanning, it is particularly suitable for an application using the constant angular velocity in the reciprocation.

When driving as described above, it is necessary to adjust a plurality of natural vibration modes to a desired relationship and stabilize the displacement angle and the swing motion. The optical deflector of this example, with respect to the torsion shaft 111, by increasing the moment of inertia I ₂ of the second movable element 102 from the moment of inertia I ₁ of the first movable element 101, the desired two natural frequencies It becomes easy to adjust the relationship.

For example, when the moments of inertia of the first and second movers are in the relationship of I ₁ > I ₂ , changing the moment of inertia I ₁ causes both of the two natural frequencies to change greatly. Further, even if the inertia moment I ₂ is changed, both of the two natural frequencies are greatly changed. Therefore, the natural frequencies of the two torsion cannot be adjusted individually. On the other hand, if the inertia moment of the first and second movers is in the relationship of I ₁ <I ₂ , changing the inertia moment I ₁ or I ₂ will change the primary natural vibration mode and the secondary natural vibration mode. Either can be changed mainly. Desirably, I ₂ should be at least 4 times I ₁ .

Therefore, due to the shape variation upon to produce a light deflector, when the two natural oscillation modes are not in the desired relationship, by adjusting the moment of inertia I ₁ or I _2, the two natural oscillation modes of torsion desired The frequency relationship can be

Further, by increasing the moment of inertia I _2, it is possible to improve the amplitude amplification factor of the natural oscillation mode (sharpness Q value of the resonance). By increasing the moment of inertia, increasing the amplitude amplification factor, and suppressing the dispersion of vibration energy, the displacement angle and the stability of the swing motion can be improved.

Furthermore, when the optical deflector of the present embodiment is swung with a large displacement angle, as described above, the turbulence of the air flow generated in the second movable element 102 is significantly reduced by the air flow adjusting body 106 having the shape as described above. can do. Thereby, the displacement angle and the stability of the oscillating motion are also greatly improved. Here, even if the length perpendicular to the torsion axis 111 of the second mover 102 is made longer than the length perpendicular to the torsion axis 111 of the first mover 101, the displacement angle and the stability of the swinging motion are improved. . Further, even if the length of the second movable element 102 in the direction parallel to the torsion axis 111 is larger than the length of the first movable element 101 in the direction parallel to the torsion axis 111, the displacement angle and the stability of the swinging motion are improved. Therefore, regardless of the direction in which the second mover 102 is lengthened, the displacement angle and the stability of the swing motion can be improved. At this time, it is easy to make the inertia moment I ₂ larger than the inertia moment I _1. It is.

Further, in the optical deflector of the present embodiment, the first movable element 101 is supported in a cantilever form, and the support body 105, one first torsion spring 103, and one second torsion spring 104 are connected. ing. Therefore, even if an unnecessary force is applied to the support 105 due to stress or thermal stress at the time of fixing and the fixing portion with the support 105 is deformed, the first movable element 101 and the second movable element 102 are stressed. Hardly works. Accordingly, it is possible to prevent a decrease in flatness (surface accuracy) of the reflecting surface of the first movable element 101.

In the optical deflector of the present embodiment, the second mover 102 is composed of a plurality of members (the silicon part 112, the hard magnetic body 107, and the airflow adjusting body 106), and the first mover having the reflecting surface 114. 101 is formed of a single member. Therefore, when the hard magnetic body 107 and the airflow adjusting body 106 are bonded and fixed to the silicon portion 112, even if the second movable element 102 is deformed, the reflecting surface 114 on the first movable element 101 is not deformed. Therefore, deterioration of the scanning spot can be reliably prevented.

According to the optical deflector of the present embodiment, since the saddle-shaped airflow adjusting bodies as described above are provided on both the upper and lower surfaces of the second mover, the swinging motion is stable even when the displacement angle of the mover is relatively large, Stable light scanning can be performed without reducing the amount of light beam to be scanned.

(Second embodiment)
FIG. 3A is a top view of the optical deflector of the second embodiment. 3B is a cross-sectional view taken along the line 2A-2A ′ of FIG. 3A, and FIG. 3B is a cross-sectional view taken along the line 2B-2B ′ of FIG. 3A. As shown in FIG. 3A, in the optical deflector of this embodiment, the first movable element 201 is supported by two first torsion springs 203. Each of the two second movers 202 supports a first torsion spring 203 and is supported by a second torsion spring 204. The two support bodies 205 support the second torsion spring 204, respectively.

Also here, the first mover 201 is composed of a reflective surface 214 and a silicon portion 213. The material of the reflecting surface 214 is aluminum, for example, and is formed by vacuum deposition. A protective film may be formed on the outermost surface of the reflecting surface. The two second movers 202 each have a silicon part 212 and two hard magnetic bodies 207. The upper and lower surfaces of the silicon part 212 and the two hard magnetic bodies 207 are bonded to each other with an adhesive.

The two air flow adjusting bodies 206 are in contact with the upper and lower surfaces of the silicon portion 212 of the second mover, and have a hemispherical shape or a semi-elliptical spherical shape. The material of the airflow adjusting body 206 is, for example, a resin having a high surface tension, and the airflow adjusting body 206 itself serves as an adhesive and is bonded to the silicon portion 212 and the hard magnetic body 207. Further, since the surface tension is strong, the air flow adjusting body 206 can be accurately placed in the center of the silicon portion 212. Therefore, the center of gravity of the second movable element 202 can be easily made to substantially coincide with the torsion shaft 211. The shape of the air flow adjusting body 206 can be adjusted flexibly according to the strength of the surface tension of the resin, the amount of the resin, the shape of the silicon portion 212 of the second mover, and the like. Therefore, in the illustrated example of FIG. 3-1, the four corners of the silicon portion 212 of the second mover slightly protrude from the air flow adjusting body 206, but of course, the entire silicon portion 212 is covered with the air flow adjusting body having a smooth curved surface. You can also.

Further, in the optical deflector of the present embodiment, the mover is supported in the form of a doubly supported beam, and the support body 205, the two second torsion springs 204, and the two first torsion springs 203 are connected in series. ing. Accordingly, it is possible to more reliably suppress the shaft collapse caused by the deviation of the center of gravity of the torsion shaft 211 and the second mover 202.

Also in this embodiment, one coil 208 wound in an oval shape is disposed below the permanent magnet, which is a hard magnetic body 207 bonded to each of both surfaces of the second mover 202. . The coil 208 is provided on the substrate 210 that supports the support 205 via the spacer 209. The permanent magnet, which is the hard magnetic body 207, and the coil 208 constitute drive means. When a current is passed through the coil 208, torque acts on the hard magnetic bodies 207 on the two second movers 202, and the first mover 201 And the entire vibration system including the two second movable elements 102 are driven. Here, the driving principle of the first movable element 201 is the same as that of the first embodiment.

Also with the optical deflector of the present embodiment, the air flow adjusting bodies as described above are provided on both the upper and lower surfaces of the two second movers, so that even when the displacement angle of the mover is relatively large, the oscillating motion is stable and scanning is performed. Stable optical scanning can be performed without reducing the amount of light beam.

(Third embodiment)
FIG. 4A is a top view of the optical deflector of the third embodiment. Fig. 4-1 (b) is a cross-sectional view taken along 3A-3A 'in Fig. 4-1 (a), and Fig. 4-2 is a cross-sectional view taken along 3B-3B' in Fig. 4-1 (a). As shown in FIG. 4-1, the first movable element 301 is supported by a first torsion spring 303. The second mover 302 supports the first torsion spring 303 and is supported by the second torsion spring 304. The support body 305 supports the second torsion spring 304.

In the present embodiment, the first movable element 301 includes a reflective surface 314 and a rectangular silicon portion 313. The material of the reflecting surface 314 is aluminum, for example, and is formed by vacuum deposition. A protective film may be formed on the outermost surface of the reflecting surface. The second mover 302 has a circular silicon portion 312 and two hard magnetic bodies 307.

The airflow adjusting body 306 is in contact with the silicon portion 312 of the second movable element 302 and the two hard magnetic bodies 307 so as to surround and enclose them, and has a spherical shape. The material of the air flow adjusting body 306 is, for example, a curable resin. The surface tension of the resin before curing is strong, and the resin itself serves as an adhesive and is bonded to the silicon portion 312 and the hard magnetic body 307. Further, the surface tension before curing is strong, and the silicon portion 312 and the hard magnetic body 307 can be accurately arranged at the center of the airflow adjusting body 306. Therefore, the center of gravity of the second movable element 302 substantially coincides with the torsion shaft 311.

In the present embodiment, as described above, since the spherical airflow adjusting body 306 includes the silicon portion 312 and the two hard magnetic bodies 307, the center of gravity of the torsion shaft 311 and the second movable element 302 can be easily set during mounting. It can be in a state that almost matches. After mounting the curable resin in this manner, the resin can be cured by applying heat or irradiating light to the resin, and the air flow adjusting body 306 can be easily formed into a desired shape.

Also in the present embodiment, the coil 308 is disposed below the permanent magnet, which is the hard magnetic body 307 bonded to each of both surfaces of the second movable element 302. The coil 308 is provided on the substrate 310 that supports the support 305 via the spacer 309. The permanent magnet, which is the hard magnetic body 307, and the coil 308 constitute driving means, and when a current is passed through the coil 308, torque acts on the hard magnetic body 307 on the second mover 302, and the first mover 301 and the second coil The entire vibration system including the mover 302 is driven. Again, the driving principle of the first mover 301 is the same as in the first embodiment.

Even in the optical deflector of this embodiment, the spherical airflow adjusting body as described above is provided in the second movable element, so that the oscillating motion is stable even when the displacement angle of the movable element is relatively large, and the scanning light beam Stable optical scanning can be performed without reducing the amount of light.

(Fourth embodiment)
The airflow adjusting body can also be provided in an oscillator device as shown in FIG. 6 used for the description of the background art. In this case, for example, an arch-shaped airflow adjusting body is provided on the upper and lower portions in the drawing of the frame-shaped movable portion 1002 that supports the movable portion 1001 (that is, the portion that avoids the portion near the cutting line 1090 passes). This provision may be performed in the same manner as when the arch-shaped airflow adjusting body is provided in the first embodiment. Further, an airflow adjusting body may be provided on both surfaces of the entire frame-shaped movable unit 1002 so that the outer shape of the movable unit 1002 has a rounded donut shape.

Again, a saddle-shaped or arch-shaped airflow adjuster may be provided on the surface of the movable portion 1001 that is not the light reflecting surface. Further, the movable portion 1001 may be supported by a frame-shaped movable portion 1002 so as to be swingable in the form of a cantilever using a single torsion spring. Furthermore, the airflow adjusting body can be provided in an oscillator device having a vibration system composed of a single mover. In this case, if the oscillator device constitutes an optical deflector, an airflow adjuster is provided on a surface that is not a light reflecting surface of the mover.

As described above, an optical deflector is provided that has a reflecting surface on one movable element and includes a driving unit that applies torque to at least one movable element to swing the movable element. Of course, when the oscillator device constitutes a sensor or the like, an airflow adjusting body can be provided on both surfaces of the mover or the driving means can be omitted as necessary.

(Fifth embodiment)
FIG. 5 is a diagram showing an embodiment of an optical apparatus using an optical deflector using the oscillator device of the present invention. Here, an image forming apparatus is shown as an optical apparatus. In FIG. 5, reference numeral 503 denotes an optical deflector according to the present invention. In this embodiment, incident light is scanned one-dimensionally. Reference numeral 501 denotes a laser light source. Reference numeral 502 denotes a lens or lens group, 504 denotes a writing lens or lens group, 505 denotes a photoconductor as a light incident target, and 506 denotes a scanning locus.

The laser light emitted from the laser light source 501 is subjected to predetermined intensity modulation related to the timing of light deflection scanning, and is scanned one-dimensionally by the optical deflector 503. The scanned laser beam forms an image on the photosensitive member 505 rotating at a constant speed around the rotation center by the writing lens 504. The photosensitive member 505 is uniformly charged by a charger (not shown), and an electrostatic latent image is formed on the portion by scanning light thereon. Next, a toner image is formed on the image portion of the electrostatic latent image by a developing device (not shown), and an image is formed on the paper by transferring and fixing the image on, for example, a paper (not shown). With the optical deflector according to the present invention, the angular velocity of light deflection scanning can be made to be substantially equal angular velocity within a specified range. Further, by using the optical deflector of the present invention, an image forming apparatus that performs stable image formation can be obtained.

An optical deflector configured by an oscillator device of the present invention including a movable element provided with a reflecting surface and a driving unit that applies torque to at least one movable element to swing the movable element is used for an image display device. You can also. Here, the light deflector deflects the light from the light source and causes at least a part of the light to be incident on the light incident target body, that is, the image display body.

The oscillator device of the present invention can be used as a potential sensor, an acceleration sensor, etc. in addition to the optical deflector. In the case of a potential sensor, for example, two detection electrodes are provided on one surface of the mover so as to face the potential measurement object with an insulating layer interposed therebetween, and a permanent magnet and an airflow adjuster are provided on the other surface. . With such a configuration, the capacitance between the measurement object and the detection electrode is mechanically changed by stably vibrating the mover around the rotation axis, and the minute change in the charge induced to the detection electrode by electrostatic induction is changed. The potential is measured by detecting via the current signal. Here, since the signals from the detection electrodes change in opposite phases, by performing differential processing on these signals, a potential sensor with a high in-phase noise removal ratio can be obtained.

When the oscillator device is an acceleration sensor, for example, an airflow adjusting body is provided on both surfaces of the mover, and a piezo element is formed on the torsion spring. When the mover rotates around the rotation axis by the action of an external force, the magnitude of the external force is measured by detecting the magnitude with a piezo element. Also in this case, by providing the airflow adjusting body, the accuracy of rotation of the mover is improved, and a sensor with high accuracy can be obtained.

(A) is a top view for explaining the optical deflector of the first embodiment of the present invention, and (b) is a cross-sectional view for explaining the optical deflector of the first embodiment of the present invention. is there. 1 is a cross-sectional view for explaining an optical deflector according to a first embodiment of the present invention. (A) is a figure which shows the displacement angle of the needle | mover of the optical deflector of the Example of this invention, (b) is a figure which shows the angular velocity of the needle | mover of the optical deflector of the Example of this invention. (A) is a top view for demonstrating the optical deflector of the 2nd Example of this invention, (b) is sectional drawing for demonstrating the optical deflector of the 2nd Example of this invention. is there. FIG. 6 is a cross-sectional view for explaining an optical deflector according to a second embodiment of the present invention. (A) is a top view for demonstrating the optical deflector of the 3rd Example of this invention, (b) It is sectional drawing for demonstrating the optical deflector of the 3rd Example of this invention. . FIG. 6 is a cross-sectional view for explaining an optical deflector according to a third embodiment of the present invention. FIG. 10 is a diagram for explaining an optical apparatus according to a fourth embodiment of the present invention. It is a top view explaining the optical deflector of a prior art. It is a perspective view explaining the optical deflector of a prior art.

Explanation of symbols

101, 102, 201, 202, 301, 302, 1001, 1002 mover (first mover, second mover)
103, 104, 203, 204, 303, 304, 1011a, 1011b, 1012a, 1012b torsion spring (first torsion spring, second torsion spring)
105, 205, 305, 1021 Support (support frame)
106, 206, 306 Airflow regulator
107, 207, 307, 1041 Driving means (hard magnetic material, permanent magnet)
108, 208, 308 Driving means (coil)
111, 211, 311 Rotating shaft (torsion shaft)
112, 113, 212, 213, 312, 313 Mover (silicon part)
114, 214, 314 Reflective surface
501 Light source (laser light source)
503 Optical deflector (optical scanning system)
505 Light incident target (photoconductor)

Claims (6)

An oscillator device including at least one mover supported so as to be swingable about a rotation axis,
An airflow adjuster is provided on at least a part of the mover,
The surface of the airflow adjusting body has a curved shape in each cross section perpendicular to the rotation axis.
An oscillator device characterized by the above. One movable element is provided with a reflective surface,
Drive means for applying a torque to at least one mover to swing the mover;
2. The oscillator device according to claim 1, wherein A support, a first mover having a reflective surface, at least one second mover, and at least one airflow adjuster provided on the second mover,
The first movable element and the second movable element are supported by a torsion spring so that the first movable element and the second movable element can be torsionally vibrated around the same torsion axis as the rotation axis.
3. The oscillator device according to claim 2, wherein The airflow adjuster has a bowl shape, a semi-cylindrical shape, a semi-elliptical sphere shape, or a hemispherical shape,
4. The oscillator device according to any one of claims 1 to 3, wherein: The airflow adjustment body has a spherical shape and includes the mover.
4. The oscillator device according to any one of claims 1 to 3, wherein: A light source, a light deflector configured by the oscillator device according to any one of claims 2 to 5, and a light incident target body,
The light deflector deflects light from the light source and causes at least a part of the light to enter the light incident target body.
Optical equipment characterized by that.

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