JP5040452B2 - Actuator, optical scanner and image forming apparatus - Google Patents

Description

The present invention relates to an actuator, an optical scanner, and an image forming apparatus.
For example, as an optical scanner for performing drawing by optical scanning with a laser printer or the like, an optical scanner using an actuator composed of a torsional vibrator is known (for example, see Patent Document 1).
For example, the actuator (optical scanning device) according to Patent Document 1 is configured by a torsional vibrator having a one-degree-of-freedom vibration system. That is, the actuator is configured to support a movable plate (a mirror with a magnet) so as to be rotatable with respect to a support portion (housing) via a shaft member (super elastic alloy wire).

Then, by applying an AC voltage to the coil, the movable plate is rotationally driven while twisting and deforming the shaft member, thereby scanning the light reflected by the light reflecting portion. Thereby, drawing can be performed by optical scanning.
However, in the actuator according to Patent Document 1, even if the direction of the magnetic field is switched, an inertial force of the movable plate that repels the magnetic force generated by the magnetic field is generated. In this case, the movement of the movable plate may be disturbed (for example, minute vibrations are generated). That is, with the actuator according to Patent Document 1, it is difficult to regulate the behavior of the movable plate, and it is difficult to exhibit desired rotation characteristics (scanning characteristics).

JP-A-9-243944

  An object of the present invention is to provide an actuator, an optical scanner, and an image forming apparatus capable of reliably regulating the behavior of a movable plate with a simple configuration.

Such an object is achieved by the present invention described below.
The actuator according to the present invention includes a movable movable plate,
At least one regulating member that is provided so as to face the plate surface of the movable plate and regulates the behavior of the movable plate by collision with the movable plate or an accessory joined to the movable plate;
The restricting member includes a buffering portion at a portion where the movable plate or the accessory collides, and the buffering portion or the accessory collides with the buffering portion so that the buffering portion is inertial of the movable plate. It is configured to restrict the behavior of the movable plate while absorbing force.
Thereby, the behavior of the movable plate can be reliably controlled with a simple configuration.

In the actuator according to the aspect of the invention, it is preferable that the buffer portion is made of an elastic material as a main material.
Thereby, the buffer part can absorb the inertial force of the movable plate more efficiently.
In the actuator according to the aspect of the invention, it is preferable that the surface of the buffer portion has releasability from the movable plate.
Thereby, it is possible to prevent the behavior of the movable plate from being disturbed or the movable plate and the buffer portion from being damaged by sticking the movable plate to the collision portion.

In the actuator according to the aspect of the invention, it is preferable that the restricting member is provided so as to collide with a portion located distal to the rotation center axis of the movable plate.
Thereby, the rotation angle of the movable plate can be restricted to a desired angle without attaching the restricting member with high accuracy. That is, the behavior of the movable plate can be restricted to a desired one while simplifying the manufacture of the actuator.

In the actuator according to the aspect of the invention, it is preferable that at least one pair of the restricting members is provided so as to be positioned on opposite sides with respect to a rotation center axis of the movable plate in a plan view of the movable plate.
Thus, the behavior of the movable plate can be reliably regulated while reducing the size of the actuator.

In the actuator according to the aspect of the invention, it is preferable that at least one pair of the regulating members is provided so as to be located on opposite sides of the movable plate.
Thereby, the inertia force of the movable plate can be absorbed by the pair of buffer portions, and the inertia force of the movable plate can be absorbed more efficiently.
In the actuator according to the aspect of the invention, it is preferable that the distances between the restricting members and the rotation center axis of the movable plate are substantially equal to each other.
Thereby, the rotation angle of the movable plate can be regulated to a desired angle while simplifying the arrangement of the regulating member.

In the actuator of the present invention, the accessory is at least one permanent magnet that is magnetized in the thickness direction of the movable plate, and the restricting member includes a magnetic field generator that generates a magnetic field that acts on the permanent magnet. It is preferable that the movable plate is rotated by the operation of the magnetic field generator.
Thereby, a large driving force can be obtained.

In the actuator according to the present invention, it is preferable that the magnetic field generator has voltage application means for applying a sawtooth AC voltage.
Thereby, an actuator suitable for vertical scanning can be provided.
In the actuator of the present invention, it is preferable that a light reflecting portion having light reflectivity is provided on one plate surface of the movable plate.
Accordingly, the actuator can be used for an optical device such as an optical scanner, an optical switch, or an optical attenuator.
In the actuator according to the aspect of the invention, it is preferable that at least one pair of the restriction members is provided so as to be positioned on a surface opposite to the light reflecting portion of the movable plate.
Thereby, it is possible to prevent the optical scanning of the actuator from being obstructed.

The optical scanner of the present invention includes a rotatable movable plate provided with a light reflecting portion having light reflectivity,
At least one regulating member that is provided so as to face the plate surface of the movable plate and regulates the behavior of the movable plate by collision with the movable plate or an accessory joined to the movable plate;
The restricting member includes a buffering portion at a portion where the movable plate or the accessory collides, and the buffering portion or the accessory collides with the buffering portion so that the buffering portion is inertial of the movable plate. It is configured to restrict the behavior of the movable plate while absorbing force.
Thereby, it is possible to provide an optical scanner that can regulate the behavior of the movable plate with a simple configuration.

An image forming apparatus of the present invention includes a rotatable movable plate provided with a light reflecting portion having light reflectivity,
At least one regulating member that is provided so as to face the plate surface of the movable plate and regulates the behavior of the movable plate by collision with the movable plate or an accessory joined to the movable plate;
The restricting member includes a buffering portion at a portion where the movable plate or the accessory collides, and the buffering portion or the accessory collides with the buffering portion so that the buffering portion is inertial of the movable plate. An optical scanner configured to regulate the behavior of the movable plate while absorbing force is provided.
As a result, it is possible to provide an image forming apparatus that can reliably regulate the behavior of the movable plate with a simple configuration.

Hereinafter, preferred embodiments of an actuator, an optical scanner, and an image forming apparatus of the present invention will be described with reference to the accompanying drawings.
<First Embodiment>
First, a first embodiment of the actuator of the present invention will be described.
1 is a schematic perspective view showing a first embodiment of the actuator of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG. 4 is a diagram showing an example of a voltage waveform of the drive voltage of the actuator shown in FIG. 1, and FIG. 5 is a diagram showing the operation of the actuator shown in FIG. In the following, for convenience of explanation, the front side of the page in FIG. 1 is referred to as “up”, the back side of the page is referred to as “down”, the right side is referred to as “right”, and the left side is referred to as “left”. The upper side is called “upper”, the lower side is called “lower”, the right side is called “right”, and the left side is called “left”.
As shown in each drawing, the actuator 1 includes a base body 2 as shown in FIG. 1, a support substrate 4 that supports the base body 2 via a spacer member 31, and a lid that is joined to the base body 2 via a spacer member 32. 5 and four regulating members 61 to 64 that regulate the behavior of the movable plate 21 included in the base 2.

Hereinafter, these will be sequentially described.
As shown in FIG. 1, the base 2 supports the movable plate 21, a pair of shaft members 22, 23 that support both of the movable plates 21, and the pair of shaft members 22, 23. And a support portion 24 that performs the above-described operation.
The movable plate 21 has a rectangular shape in plan view. And this movable plate 21 is extended along the direction orthogonal to the rotation center axis | shaft X mentioned later.
On the upper surface of the movable plate 21 (that is, the surface on the lid 5 side), a light reflecting portion 211 having light reflectivity is provided at the center in the longitudinal direction, and both end portions (that is, Permanent magnets 71 and 72 are provided on a portion (distant from the rotation center axis X).

On the other hand, permanent magnets 73 and 74 are provided on the lower surface of the movable plate 21 at both ends in the longitudinal direction.
In addition, it does not specifically limit as a planar view shape of the movable plate 21, For example, circular shape may be sufficient and square shape may be sufficient.
The movable plate 21 as described above is supported from both sides by a pair of shaft members 22 and 23.

The shaft member 22 has a rod shape. One end (right end in FIG. 1) of the shaft member 22 in the longitudinal direction is connected to the movable plate 21, and the other end (left end in FIG. 1) is connected to the support portion 24.
Similarly, the shaft member 23 has a rod shape. One end (left end in FIG. 1) of the shaft member 23 in the longitudinal direction is connected to the movable plate 21, and the other end (right end in FIG. 1) is connected to the support portion 24.

The pair of shaft members 22 and 23 are provided coaxially, and the movable plate 21 rotates with respect to the support portion 24 with this axis as the rotation center axis X. The pair of shaft members 22 and 23 have the same size and the same shape.
The support 24 is formed so as to surround the outer periphery of the movable plate 21 and the pair of shaft members 22 and 23 in a plan view of the movable plate 21. That is, the support part 24 has a frame shape.

  The base 2 as described above is made of, for example, silicon as a main material, and a movable plate 21, a pair of shaft members 22, 23, and a support portion 24 are integrally formed. For example, a silicon substrate is prepared, and this silicon substrate is etched so as to correspond to the shape of each of the movable plate 21, the pair of shaft members 22 and 23, and the support portion 24. The base body 2 in which the pair of shaft members 22 and 23 and the support portion 24 are integrally formed can be easily obtained. In addition, by using silicon as the main material as described above, it is possible to realize excellent rotation characteristics and to exhibit excellent durability. Further, fine processing (processing) is possible, and the actuator 1 can be miniaturized.

The base 2 may be formed by forming the movable plate 21, the pair of shaft members 22, 23, and the support portion 24 from a substrate having a laminated structure such as an SOI substrate. At that time, it is preferable that the movable plate 21, the pair of shaft members 22, 23, and the support portion 24 are formed of one layer of the laminated structure substrate so as to be integrated.
The base 2 described above is bonded to the support substrate 4 via the spacer member 31 on the lower side, and is bonded to the lid 5 via the spacer member 32 on the upper side.

The spacer member 31 is made of, for example, glass or silicon as a main material. The spacer member 31 is formed so as to coincide with the planar view shape of the support portion 24 (that is, has a frame shape), and the upper surface of the spacer member 31 is joined to the lower surface of the support portion 24.
A space 311 is defined by the inner wall of the spacer member 31. This space 311 is a space for allowing the movable plate 21 to rotate.

Note that the shape of the spacer member 31 is not particularly limited as long as a space allowing the rotation of the movable plate 21 can be formed. For example, the spacer member 31 may not have a frame shape.
For example, when the base 2 is formed from one Si layer of the SOI substrate, the spacer member 31 may be formed from the SiO ₂ layer and the other Si layer. Thereby, since the base | substrate 2 and the spacer member 31 can be formed integrally, simplification of the manufacturing process of an actuator can be achieved.

The support substrate 4 is bonded to the lower surface of such a spacer member 31.
The support substrate 4 has a plate shape, and is composed mainly of glass or silicon, for example.
As shown in FIG. 2, a restriction member 63 is provided on the upper surface of the support substrate 4, a portion facing the permanent magnet 73, and a restriction member 64 is provided on a portion facing the permanent magnet 74. It has been. Such restricting members 63 and 64 will be described in detail later.

The spacer member 31 and the support substrate 4 that are located below the base 2 have been described above.
On the other hand, the spacer member 32 positioned on the upper side of the base 2 is made of, for example, glass or silicon as a main material. The spacer member 32 is formed so as to coincide with the planar view shape of the support portion 24 (that is, has a frame shape), and the lower surface of the spacer member 32 is joined to the upper surface of the support portion 24.

A space 321 is defined by the inner wall of the spacer member 32. The space 321 is a space for allowing the movable plate 21 to rotate.
In the present embodiment, the spacer member 32 has the same shape and dimensions as the spacer member 31. The shape of the spacer member 32 is not particularly limited as long as a space allowing the rotation of the movable plate 21 can be formed. For example, the spacer member 32 may not have a frame shape, or may be a spacer member 31. And the same size and shape.

The lid 5 is joined to the upper surface of such a spacer member 32.
The lid 5 has a plate shape and is provided so as to cover the opening of the spacer member 32. That is, a space sealed by the support portion 24, the spacer members 31 and 32, the support substrate 4, and the lid body 5 (that is, a space combining the space 311 and the space 321) is defined. Thereby, for example, this space can be filled with an inert gas such as argon, and the rotation characteristics of the movable plate 21 can be improved.

As shown in FIG. 2, a regulating member 61 is provided on the lower surface of the lid 5, a portion facing the permanent magnet 71, and a regulating member 62 is provided on a portion facing the permanent magnet 72. It has been. Such restricting members 61 and 62 will be described in detail later.
Such a lid 5 is made of a material having optical transparency. The material having optical transparency is not particularly limited, and for example, glass or the like can be suitably used. By configuring the lid 5 with a light-transmitting material, the light reflected from the light source (not shown) provided outside the actuator 1 toward the light reflecting portion 211 is reflected by the light reflecting portion 211. And the object can be scanned.
Note that the configuration of the lid 5 is not particularly limited. For example, the lid 5 may be formed of a material that does not have optical transparency and an opening is provided in a portion facing the light reflecting portion 211. Alternatively, a material that does not transmit light and a material that transmits light may be combined.

Next, the permanent magnets 71 to 74 provided on the movable plate 21 will be described.
As shown in FIG. 2, the pair of permanent magnets 71 and 72 provided on the upper surface of the movable plate 21 are located on the opposite sides with respect to the rotation center axis X in a plan view of the movable plate 21. And it is provided symmetrically with respect to the rotation center axis X.
Similarly, the pair of permanent magnets 73 and 74 provided on the lower surface of the movable plate 21 are positioned opposite to each other with respect to the rotation center axis X in the plan view of the movable plate 21 and rotate. They are provided symmetrically with respect to the central axis X.

Further, the permanent magnets 71 and 73 are provided to face each other on the left side in FIG. 2 with respect to the rotation center axis X of the movable plate 21. Similarly, the permanent magnets 72 and 74 are provided to face each other on the right side of FIG. 2 with respect to the rotation center axis X of the movable plate 21.
The permanent magnet 71 has a longitudinal shape, and is provided so that the direction parallel to the rotation center axis X is the longitudinal direction. The length of the permanent magnet 71 is substantially equal to the width of the movable plate 21 (that is, the length in the direction parallel to the rotation center axis X). Further, the cross-sectional shape of the permanent magnet 71 is a quadrangular shape. However, the shape of the permanent magnet 71 is not particularly limited. For example, the length of the permanent magnet 71 may be shorter than the width of the movable plate 21.

Since the permanent magnets 72 to 74 have the same shape and the same dimensions as the permanent magnet 71, description thereof is omitted.
Such permanent magnets 71 to 74 are respectively magnetized in the thickness direction of the movable plate 21 (that is, the vertical direction in FIG. 2). Furthermore, the permanent magnets 71 and 73 have opposite polarities on opposite surface sides. Similarly, the permanent magnets 72 and 74 have opposite polarities on opposite surface sides.

As shown in FIG. 2, in this embodiment, the permanent magnets 71 and 73 have an S pole on the upper surface side and an N pole on the lower surface side, respectively, and the permanent magnets 72 and 74 have an N pole and lower surface on the upper surface side, respectively. The side is the S pole.
Such permanent magnets 71 to 74 are not particularly limited, and neodymium magnets, ferrite magnets, samarium cobalt magnets, alnico magnets, and the like can be suitably used.

Next, the regulating members 61 to 64 will be described.
As shown in FIG. 2, the regulating members 61 and 62 are provided on the upper surface side of the movable plate 21. Such restricting members 61 and 62 are provided symmetrically with respect to the rotation center axis X so as to be positioned on opposite sides of the rotation center axis X in a plan view of the movable plate 21. ing.
The regulating member 61 is provided at a predetermined distance from the permanent magnet 71 in the vertical direction of FIG. The restricting member 61 is provided so as to include the permanent magnet 71 in a region surrounded by the outer periphery of the movable plate 21 in a plan view.

Similarly, the regulating member 62 is provided at a predetermined distance from the permanent magnet 72 in the vertical direction of FIG. Further, the restriction member 62 is provided so as to include the permanent magnet 72 in a region surrounded by the outer periphery of the movable plate 21 in a plan view.
On the other hand, the regulating members 63 and 64 are provided on the lower surface side of the movable plate 21. Such regulating members 63 and 64 are provided symmetrically with respect to the rotation center axis X so as to be positioned on opposite sides of the rotation center axis X in a plan view of the movable plate 21. ing.

The regulating member 63 is provided at a predetermined distance from the permanent magnet 73 in the vertical direction of FIG. The restricting member 63 is provided so as to include a permanent magnet 73 in a region surrounded by the outer periphery of the movable plate 21 in a plan view.
Similarly, the restricting member 64 is provided at a predetermined distance from the permanent magnet 74 in the vertical direction of FIG. The restricting member 64 is provided so as to include a permanent magnet 74 in a region surrounded by the outer periphery of the movable plate 21 in a plan view.

  Further, as shown in FIG. 2, the regulating members 61 and 63 are located on the left side with respect to the rotation center axis X of the movable plate 21. The regulating members 61 and 63 are located on the opposite sides of the base 2 and are provided symmetrically with respect to the base 2. Similarly, the restricting members 62 and 64 are located on the right side with respect to the rotation center axis X of the movable plate 21. The regulating members 62 and 64 are located on opposite sides of the base 2 and are provided symmetrically with respect to the base 2.

When the actuator 1 is driven, the regulating members 61 to 64 collide with the movable plate 21 by collision with the permanent magnets 71 to 74, that is, by colliding with the movable plate 21 via the permanent magnets 71 to 74. It has a function to regulate behavior.
In the present embodiment, the separation distance between the restriction member 61 and the permanent magnet 71, the separation distance between the restriction member 62 and the permanent magnet 72, the separation distance between the restriction member 63 and the permanent magnet 73, the restriction member 64 and the permanent magnet. The separation distance from 74 is equal to each other. In other words, the distances between the regulating members 61 to 64 and the rotation center axis X are substantially equal to each other. Thereby, the rotation angle of the movable plate 21 can be regulated to a desired angle while simplifying the arrangement of the regulating members 61 to 64.

  Further, such a restricting member 61 is configured to collide with a portion located distal to the rotation center axis of the movable plate 21 via the permanent magnet 71. Similarly, the restricting members 62 to 64 are configured to collide with a portion located distal to the rotation center axis X of the movable plate 21 via the corresponding permanent magnets 72 to 74. Thereby, compared with the case where the regulation members 61-64 collide with the site | part located proximally from the rotation center axis | shaft of the movable plate 21, even if it does not perform attachment of the regulation members 61-64 with high precision, The rotation angle of the movable plate 21 can be restricted to a desired angle. That is, the behavior of the movable plate 21 can be restricted to a desired one while simplifying the manufacture of the actuator 1.

Hereinafter, specific configurations of the regulating members 61 to 64 will be described. Since the regulating members 61 to 64 have the same configuration as each other, the regulating member 64 will be described as a representative, and the explanation of the regulating members 61 to 63 will be described. The description is omitted.
The restricting member 64 has a cylindrical shape. As shown in FIG. 3, such a restricting member 64 includes a cylindrical coil (magnetic field generating unit) 641 and a buffer unit 642 joined to the upper end of the coil 641. Such a regulating member 64 absorbs the inertial force of the movable plate 21 by the buffer portion 642 when the movable plate 21 collides with the buffer portion 642 via the permanent magnet 74 when the actuator 1 is driven. The behavior of the movable plate 21 is restricted. Further, such a restricting member 64 also has a function as a driving unit that rotates the movable plate 21.

  The coil 641 is bonded to the upper surface of the support substrate 4. The coil 641 is connected to a voltage application unit (not shown). When a voltage is applied to the coil 641 by the voltage applying means, a magnetic field having magnetic lines of force in the vertical direction of FIG. 3 (that is, the thickness direction of the movable plate 21) is generated in the vicinity of the coil 641. Note that a magnetic core may be provided inside the coil 641.

The buffer portion 642 is joined to the upper end of the coil 641. Such a buffer portion 642 has an annular shape in a plan view of the movable plate 21. The shape of the buffer portion 642 is not particularly limited as long as the inertial force of the movable plate 21 can be absorbed, and may be, for example, a disc shape.
The buffer portion 642 has a function of absorbing the inertial force of the movable plate 21. Such a buffer 642 is formed to be elastically deformable, and elastically deforms when the movable plate 21 collides, and absorbs the inertial force of the movable plate 21 by this elastic deformation.

  The constituent material of the buffer portion 642 is not particularly limited as long as the inertial force of the movable plate 21 can be absorbed by elastic deformation. For example, a polymer material such as resin, rubber, or elastomer is used as a main material. Has been. Thereby, the inertia force of the movable plate 21 can be efficiently absorbed by the buffer portion 642. Such a polymer material is not particularly limited, and examples thereof include rubber, various thermoplastic resins, and various thermosetting resins.

  Examples of rubber include butadiene rubbers such as natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR, 1,2-BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), and butadiene. -Olefin rubbers such as diene special rubber such as acrylonitrile rubber (NBR), butyl rubber (IIR), ethylene-propylene rubber (EPM, EPDM), acrylic rubber (ACM, ANM), halogenated butyl rubber (X-IIR) , Urethane rubber such as urethane rubber (AU, EU), ether rubber such as hydrin rubber (CO, ECO, GCO, EGCO), polysulfide rubber such as polysulfide rubber (T), silicone rubber (Q), fluorine rubber (FKM, FZ), various rubbers such as chlorinated polyethylene (CM), styrene, Various thermoplastic elastomers such as olefin-based, polyvinyl chloride-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, chlorinated polyethylene-based, etc., are included. Two or more kinds can be used by mixing (blending).

  Examples of the thermoplastic resin include polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer, modified polyolefins, polyamides (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12). , Nylon 6-12, nylon 6-66), thermoplastic polyimide, aromatic polyester and other liquid crystal polymers, polyphenylene oxide, polyphenylene sulfide, polycarbonate, polymethyl methacrylate, polyether, polyether ether ketone, polyether imide, polyacetal, Styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluoro rubber, salt Various thermoplastic elastomers, etc., or a copolymer of these His polyethylene type or the like, blends, polymer alloys and the like, can be used as a mixture of two or more of them.

Examples of the thermosetting resin include epoxy resin, phenol resin, urea resin, melamine resin, polyester (unsaturated polyester) resin, polyimide resin, silicone resin, polyurethane resin, and the like. A mixture of seeds or more can be used.
Moreover, it is preferable that the buffer part 642 has the outstanding restoring | restoration property. Thereby, every time the movable plate 21 collides with the buffer portion 642, the inertia force of the movable plate 21 can be absorbed by the buffer portion 642. As a result, the actuator 1 can be continuously driven for a long time with a desired behavior.

Moreover, it is preferable that the surface of the buffer part 642 has releasability with respect to the movable plate 21. Thereby, when the movable plate 21 collides with the buffer portion 642, the movable plate 21 sticks to the collision portion 642, thereby disturbing the behavior of the movable plate 21 or damaging the movable plate 21 or the buffer portion 642. Can be prevented.
The configuration of the actuator 1 has been described above.

Next, the operation of the actuator 1 will be described in detail.
Similarly to the restriction member 64 having the coil 641, the restriction member 61 has a coil 611, the restriction member 62 has a coil 621, and the restriction member 63 has a coil 631. . Such four coils 611, 621, 631, 641 are connected to the voltage applying means, respectively.
Then, for example, when a sawtooth AC voltage as shown in FIG. 4 is applied to the coils 611, 621, 631, 641 by the voltage applying means, the movable plate 21 is located near the coils 611, 621, 631, 641. A magnetic field having magnetic field lines in the thickness direction is generated, and the direction of the magnetic field is periodically switched.

In the present embodiment, the directions of the magnetic fields generated from the coils 611 and 621 on the upper side of the movable plate 21 are configured to be the same. Similarly, the directions of the magnetic fields generated from the coils 631 and 641 below the movable plate 21 are configured to be the same. Further, the directions of the magnetic fields generated from the coils 611 and 631 (which are the same for the coils 621 and 641) opposed via the base 2 are opposite to each other.
That is, when the vicinity of the lower surface of each of the coils 611 and 621 is an S pole, the vicinity of the upper surface of each of the coils 631 and 641 is also an S pole, and the vicinity of the lower surface of each of the coils 611 and 621 is an N pole. In this case, the vicinity of the upper surface of each of the coils 631 and 641 is also configured to have N poles.

Hereinafter, for convenience of explanation, the case where the vicinity of the lower surfaces of the coils 611 and 621 and the vicinity of the upper surfaces of the coils 631 and 641 are S poles is referred to as a “first state”, and the vicinity of the lower surfaces of the coils 611 and 621 , 641 is the “second state” when the vicinity of the top surface is an N pole.
In the first state, as shown in FIG. 5A, the right portion is displaced upward and the left portion is displaced downward with respect to the rotation center axis X of the movable plate 21. . That is, the movable plate 21 rotates counterclockwise in FIG. At this time, the rotational speed (angular speed) of the movable plate 21 is substantially constant.

And while the permanent magnet 72 collides with the buffer part 622 and the permanent magnet 73 collides with the buffer part 632, rotation of the movable plate 21 is regulated. At this time, the inertial force of the movable plate 21 is absorbed by the buffer portions 622 and 632. Thus, by absorbing the inertial force of the movable plate 21 by the pair of buffer portions 622 and 632, the inertial force of the movable plate 21 can be absorbed more efficiently.
In such a first state, a magnetic repulsive force acting between the coil 611 and the permanent magnet 71 and between the coil 641 and the permanent magnet 74, and between the coil 621 and the permanent magnet 72 and between the coil 631 and The movable plate 21 is rotated by the magnetic attraction force acting between the permanent magnet 73 and the permanent magnet 73. Therefore, the movable plate 21 can be rotated with a large driving force.

When the movable plate 21 collides with the buffer portions 622 and 632, almost simultaneously, the first state is switched to the second state.
In the second state, as shown in FIG. 5 (b), the right part is displaced downward and the left part is displaced upward with respect to the rotation center axis X of the movable plate 21. . That is, the movable plate 21 rotates clockwise in FIG. At this time, the rotational speed (angular speed) of the movable plate 21 is substantially constant and is different from the rotational speed of the movable plate 21 in the first state.

  And while the permanent magnet 71 collides with the buffer part 612 and the permanent magnet 74 collides with the buffer part 642, rotation of the movable plate 21 is controlled. At this time, the inertial force of the movable plate 21 is absorbed by the buffer portions 612 and 642. In this manner, by absorbing the inertial force of the movable plate 21 by the pair of buffer portions 612 and 642, the inertial force of the movable plate 21 can be absorbed more efficiently.

In such a second state, the magnetic attractive force acting between the coil 611 and the permanent magnet 71 and between the coil 641 and the permanent magnet 74, and between the coil 621 and the permanent magnet 72 and between the coil 631 and The movable plate 21 is rotated by the magnetic repulsive force acting between the permanent magnet 73 and each. Therefore, the movable plate 21 can be rotated with a large driving force.
Then, when the movable plate 21 collides with the buffer portions 612 and 642, the second state is switched to the first state described above almost simultaneously. In this manner, by alternately repeating the first state and the second state, the movable plate 21 can be rotated around the rotation center axis X while twisting and deforming the pair of shaft members 22 and 23. it can.

  Here, for example, when the movable plate 21 is rotated without colliding with the regulating members 61 to 64 as in a conventional actuator, even if the direction of the electric field is switched, the magnetic force generated by the magnetic field (that is, Since the inertial force of the movable plate 21 that repels each of the coils 611 to 614 and the magnetic repulsion force and magnetic attraction force acting between the corresponding permanent magnets 71 to 74 (hereinafter the same) is generated, The movable plate 21 cannot follow the change (change in direction) of the magnetic field, and this causes the behavior of the movable plate 21 to be disturbed (for example, minute vibrations are generated. Also called “unnecessary vibration”).

  On the other hand, in this invention, since the inertial force of the movable plate 21 is absorbed by the regulation members 61-64, generation | occurrence | production of the inertial force of the movable plate 21 which repels a magnetic force can be prevented. Therefore, it is possible to prevent unnecessary vibration of the movable plate 21 from occurring. That is, according to the actuator 1, the behavior of the movable plate 21 can be restricted to a desired one. Moreover, since the rotation angle (amplitude) of the movable plate 21 can be regulated by the regulating members 61 to 64, the behavior of the movable plate 21 can be regulated to a desired one also from this point. In the present specification, “restricting the behavior of the movable plate 21” means preventing unnecessary vibration of the movable plate 21 and restricting the rotation angle of the movable plate 21 to a desired angle. .

  Moreover, in this embodiment, since the movable plate 21 is rotated by the magnetic field generated from the four coils 611 to 641, an extremely large driving force can be obtained. Therefore, for example, when driving at a frequency extremely lower than the resonance frequency of the vibration system composed of the movable plate 21 (including the permanent magnets 71 to 74 and the light reflecting portion 211) and the pair of shaft members 22 and 23 ( That is, it is extremely suitable when a relatively large driving force is required, such as when driving without resonance.

  In the present embodiment, a sawtooth voltage is applied. However, when such a voltage is applied, the voltage change is abrupt, and thus the rotation direction of the movable plate 21 is abruptly switched. That is, when a sawtooth voltage is applied, unnecessary vibration of the movable plate 21 is very likely to occur. However, in the actuator 1, since the inertia force of the movable plate 21 is absorbed by the buffer portions 612 to 642, the occurrence of unnecessary vibration of the movable plate 21 can be prevented even when a sawtooth voltage is applied.

Second Embodiment
Next, a second embodiment of the image forming apparatus of the present invention will be described.
FIG. 6 is a schematic cross-sectional view showing a second embodiment of the actuator of the present invention. In the following, for convenience of explanation, the upper side in FIG. 6 is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.

Hereinafter, the actuator 1A of the second embodiment will be described focusing on the differences from the actuator 1 of the first embodiment described above, and the description of the same matters will be omitted. The same reference numerals are given to the same components as those in the above-described embodiment.
The actuator 1A according to the second embodiment of the present invention is substantially the same as the actuator 1 of the first embodiment except that no permanent magnet is provided on the lower surface of the movable plate.

  That is, in the actuator 1 </ b> A, the lower surface of the movable plate 21 collides with the buffer portion 642, and the upper surface of the permanent magnet 71 is collided with the buffer portion 612, thereby restricting the clockwise rotation of the movable plate 21. While causing the lower surface of the plate 21 to collide with the buffer portion 632 and causing the upper surface of the permanent magnet 72 to collide with the buffer portion 622, the counterclockwise rotation of the movable plate 21 is restricted.

The actuator 1A is designed so that the gap between the permanent magnet 71 and the regulating member 61 and the gap between the movable plate 21 and the regulating member 64 are substantially equal in the neutral state (that is, the state shown in FIG. 6). Similarly, the gap between the permanent magnet 72 and the restricting member 62 and the gap between the movable plate 21 and the restricting member 63 are designed to be substantially equal.
In the present embodiment, in order to make the gap between the permanent magnet 71 and the regulating member 61 and the gap between the movable plate 21 and the regulating member 64 substantially equal, the regulating member 64 is attached to the support substrate 4 via the spacer 42 having a desired thickness. It is joined to. Similarly, in order to make the gap between the permanent magnet 72 and the regulating member 62 and the gap between the movable plate 21 and the regulating member 63 substantially equal, the regulating member 63 is joined to the support substrate 4 via the spacer 41 having a desired thickness. is doing.

In addition, the gap between the permanent magnet 71 and the regulating member 61 and the gap between the movable plate 21 and the regulating member 64 are obtained by setting the thickness of the spacer member 31 (the length in the vertical direction in FIG. 6) to a predetermined thickness. The gap between the permanent magnet 72 and the restricting member 62 and the gap between the movable plate 21 and the restricting member 63 may be made equal.
The permanent magnets 71 and 72 may be provided on the lower surface of the movable plate 21.
In the second embodiment as described above, the same effect as that of the first embodiment can be exhibited.

<Third Embodiment>
Next, a second embodiment of the image forming apparatus of the present invention will be described.
FIG. 7 is a schematic cross-sectional view showing a third embodiment of the actuator of the present invention. In the following, for convenience of explanation, the upper side in FIG. 7 is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.

Hereinafter, the actuator 1B of the third embodiment will be described focusing on the differences from the actuator 1 of the first embodiment described above, and the description of the same matters will be omitted. The same reference numerals are given to the same components as those in the above-described embodiment.
The actuator 1B according to the third embodiment of the present invention is the actuator 1 according to the first embodiment except that a permanent magnet and a regulating member corresponding to the permanent magnet are disposed only on the lower surface side of the movable plate 21. Is almost the same.
A light reflecting portion 211 is provided on the upper surface of the movable plate 21. Further, a permanent magnet 73 is provided on the left side of the movable plate 21 with respect to the rotation center axis X, and a permanent magnet 74 is provided on the right side. Such permanent magnets 73 and 74 are provided symmetrically with respect to the rotation center axis X in a plan view of the movable plate 21.

In the actuator 1 </ b> B, no permanent magnet is provided on the upper surface of the movable plate 21, and no restriction member is provided on the upper surface side of the movable plate 21. Therefore, for example, when the actuator 1B is used as an optical scanner, even if the rotation angle of the movable plate 21 is increased, the optical scanning is not hindered by the permanent magnet or the regulating member. Further, the actuator 1 can be downsized as compared with the actuator 1 of the first embodiment.
In addition, since only the light reflecting portion 211 needs to be provided on the upper surface of the movable plate 21, the light reflecting portion 211 can be enlarged.
In the third embodiment as described above, the same effect as that of the first embodiment can be exhibited.

<Fourth embodiment>
Next, a fourth embodiment of the image forming apparatus of the present invention will be described.
FIG. 8 is a schematic plan view showing a fourth embodiment of the actuator of the present invention. In the following, for convenience of explanation, the front side of the paper in FIG. 8 is referred to as “up”, the back side of the paper is referred to as “down”, the right side is referred to as “right”, and the left side is referred to as “left”.

Hereinafter, the actuator 1 </ b> C according to the fourth embodiment will be described focusing on differences from the actuator according to the above-described embodiment, and description of similar matters will be omitted. The same reference numerals are given to the same components as those in the above-described embodiment.
The actuator 1C according to the fourth embodiment of the present invention is substantially the same as the actuator 1B of the third embodiment except that the shape of the movable plate, the arrangement of the permanent magnets, and the regulating members are different.

The movable plate 21 has projecting portions 21a to 21d that project from the left and right side walls shown in FIG.
The protrusions 21a and 21c are provided symmetrically with respect to the rotation center axis X. Similarly, the protrusions 21b and 21d are provided symmetrically with respect to the rotation center axis X. Such protrusions 21a to 21d have a substantially square shape in a plan view of the movable plate 21. The protrusions 21a to 21d have the same size and the same shape.

71 C of permanent magnets are provided in the lower surface (namely, surface facing the support substrate 4) of the protrusion part 21a. Similarly, a permanent magnet 72C is provided on the lower surface of the protruding portion 21b, a permanent magnet 73C is provided on the lower surface of the protruding portion 21c, and a permanent magnet 74C is provided on the lower surface of the protruding portion 21d. It has been.
Further, a regulating member 61C is provided on the upper surface of the support substrate 4 at a portion facing the permanent magnet 71C, and a regulating member 62C is provided at a portion facing the permanent magnet 72C. A restricting member 63C is provided at a portion facing the magnet 73C, and a restricting member 64C is provided at a portion facing the permanent magnet 74C.

In such an actuator 1 </ b> C, no permanent magnet is provided on the upper surface of the movable plate 21, and no restriction member is provided on the upper surface side of the movable plate 21. Therefore, for example, when the actuator 1B is used as an optical scanner, even if the rotation angle of the movable plate 21 is increased, the optical scanning is not hindered by the permanent magnet or the regulating member.
Moreover, in this embodiment, since the movable plate 21 is rotated by the four permanent magnets 71C to 74C and the four restricting members 61C to 64C corresponding to the permanent magnets 71C to 74C, for example, compared with the actuator 1B of the third embodiment. Thus, the movable plate 21 can be rotated with a larger driving force.

In the fourth embodiment as described above, the same effect as that of the first embodiment can be exhibited.
The actuators 1 to 1C as described above can be applied to optical devices such as an optical scanner, an optical switch, and an optical attenuator.
When the actuator 1 is used as an optical scanner, the actuator 1 (the optical scanner according to the present invention) scans the light reflected by the light reflecting unit 211.

  Such an actuator (optical scanner) can be suitably applied to an image forming apparatus such as a projector, a laser printer, an imaging display, a barcode reader, and a scanning confocal microscope. As a result, an image forming apparatus having excellent drawing characteristics can be provided.

Specifically, an image forming apparatus (projector) 100 using the actuator 1 as shown in FIG. 9 will be described. For convenience of explanation, the longitudinal direction of the screen S is referred to as “lateral direction”, and the direction perpendicular to the longitudinal direction is referred to as “vertical direction”.
The projector 100 includes a light source device 101 that emits light such as a laser, a plurality of dichroic mirrors 102, a horizontal scanning actuator 103, and a vertical scanning actuator 1.

The light source device 101 includes a red light source device 101a that emits red light, a blue light source device 101b that emits blue light, and a green light source device 101c that emits green light.
The dichroic mirror 102 is an optical element that combines light emitted from each of the red light source device 101a, the blue light source device 101b, and the green light source device 101c.
Such a projector 100 combines light emitted from each of the red light source device 101a, the blue light source device 101b, and the green light source device 101c by a dichroic mirror 102 based on image information from a host computer (not shown). The combined light is scanned by the horizontal scanning actuator 103 and the actuator 1 to form a color image on the screen S.

Here, the optical scanning of the horizontal scanning actuator 103 and the vertical scanning actuator 1 will be specifically described.
First, the light synthesized by the dichroic mirror 102 is scanned in the horizontal direction of the screen S by the horizontal scanning actuator 103 (horizontal scanning). At this time, the horizontal scanning actuator 103 is driven at a driving frequency of about 10 to 30 kHz, for example. In general, the horizontal scanning actuator 103 is designed so that its resonance frequency is equal to the driving frequency, and is configured to resonate and drive the horizontal scanning actuator 103.

The light scanned by the horizontal scanning actuator 103 is scanned in the vertical direction of the screen S by the vertical scanning actuator 1 (vertical scanning). At this time, the actuator 1 is driven at a driving frequency of about 60 Hz, for example.
For example, the actuator 1 scans the upper end of the screen S with the light reflected by the light reflecting portion 211 at a position where the movable plate 21 collides with the buffer portions 612 and 642 (that is, in the state shown in FIG. 5B). In addition, at a position where the movable plate 21 collides with the buffer portions 622 and 632 (that is, the state of FIG. 5A), the light reflected by the light reflecting portion 211 is scanned to the lower end of the screen S. Yes.

The actuator 1 rotates the movable plate 21 at a constant speed from the state shown in FIG. 5B toward the state shown in FIG. 5A, and reflects the light scanned by the horizontal scanning actuator 103 as a light reflecting portion. Reflected at 211. Thereby, the light reflected by the light reflecting portion 211 can be scanned from the upper end to the lower end of the screen S.
When the actuator 1 finishes scanning the light to the lower end of the screen S (that is, when the actuator 1 is in the state shown in FIG. 5A), the movable plate 21 is set to the state shown in FIG. 5B at the same time. Rotate quickly.
The actuator 1 again rotates the movable plate 21 at a constant speed from the state shown in FIG. 5B toward the state shown in FIG. The light reflected by the reflecting portion 211 is scanned from the upper end to the lower end of the screen S.

By repeating such an operation, the actuator 1 performs vertical scanning.
Here, in order to rotate the movable plate 21 with the behavior as described above, for example, a sawtooth AC voltage as shown in FIG. 4 is applied to each of the coils 611 to 641. Further, in order to rotate the movable plate 21 with the behavior described above, it is necessary to drive the movable plate 21 in a non-resonant manner.

That is, if the movable plate 21 is rotated with the behavior described above, unnecessary vibration of the movable plate 21 is likely to occur, and a large driving force is required to rotate the movable plate 21 with the behavior described above. Is required. From these viewpoints, the actuator 1 is extremely suitable as an actuator for vertical scanning.
As described above, a two-dimensional color image can be formed on the screen S.

  Although the actuator, optical scanner, and image forming apparatus of the present invention have been described based on the illustrated embodiments, the present invention is not limited to this. For example, in the actuator, optical scanner, and image forming apparatus of the present invention, the configuration of each part can be replaced with an arbitrary configuration that exhibits the same function, and an arbitrary configuration can be added.

In the above-described embodiments, the actuator has been described as having a structure that is substantially symmetrical with respect to the movable plate. However, the actuator may be asymmetric.
Further, in the above-described embodiment, the description has been given of the case where the base body in which the movable plate, the pair of shaft members, and the support portion are integrally formed is used. However, the present invention is not limited to this and is formed as a separate body. May be. For example, the movable plate and the pair of shaft members are integrally formed, the support portion is formed as a separate body, and the support portion is configured to rotatably support the movable plate via each shaft member. May be.

  In the above-described embodiment, two restriction members are provided on the upper side of the movable plate and two restriction members are provided on the lower side (that is, the first embodiment), or on the lower side of the movable plate. Although the two regulating members are provided (that is, the second embodiment) and the four regulating members are provided on the lower side of the movable plate (that is, the third embodiment), It is not limited to this. For example, the number of regulating members may be one, three, or five or more. Two restricting members may be provided so as to oppose each other via the movable plate.

Moreover, although embodiment mentioned above demonstrated what the regulation member was provided with the coil, it is not limited to this, The regulation member does not need to be provided with the coil. In this case, it is sufficient to provide a coil separately from the regulating member.
Moreover, although what used the electromagnetic drive which uses a coil and a permanent magnet as a drive source which drives a movable plate was demonstrated, it is not limited to this, For example, what is called electrostatic drive may be used, and what is called piezoelectric drive It may be.

It is a typical perspective view which shows 1st Embodiment of the actuator of this invention. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is a figure which shows an example of the voltage waveform of the drive voltage of the actuator shown in FIG. It is a figure which shows the action | operation of the actuator shown in FIG. It is typical sectional drawing which shows 2nd Embodiment of the actuator of this invention. It is a typical top view showing a 3rd embodiment of an actuator of the present invention. It is a typical top view showing a 4th embodiment of an actuator of the present invention. 1 is a diagram illustrating a schematic configuration of an image forming apparatus.

Explanation of symbols

  1, 1A, 1B, 1C ... Actuator 2 ... Base 21 ... Movable plates 21a to 21d ... Projection part 211 ... Light reflection part 22, 23 ... Shaft member 24 ... Support part 31, 32 ... Spacer Member 311, 321... Space 4... Support substrate 41, 42... Spacer 5... Lid 61-64, 61 C to 64 C ...... Restriction member 611, 621, 631, 641 ...... Coil 612, 622, 632, 642... Buffer section 71 to 74, 71C to 74C. Permanent magnet 100... Image forming apparatus (projector) 101... Light source apparatus 101a... Red light source apparatus 101b ... Blue light source apparatus 101c. ... Dichroic mirror 103 ... Horizontal scanning actuator S ... Screen X ... Rotation center axis

Claims (12)

A movable movable plate;
An accessory joined to the movable plate;
Provided so as to face the plate face of the movable plate, and at least one regulating member for regulating the behavior of the movable plate by colliding with the movable plate or the previous SL with genus product,
The accessory is at least one permanent magnet magnetized in the thickness direction of the movable plate, and the restricting member includes a magnetic field generating unit that generates a magnetic field acting on the permanent magnet, and the movable plate or the An actuator comprising: a buffer portion at a portion where the permanent magnet collides, and configured to rotate the movable plate by the operation of the magnetic field generating portion.   The actuator according to claim 1, wherein the buffer portion is configured with an elastic material as a main material.   The actuator according to claim 1, wherein a surface of the buffer portion has releasability from the movable plate.   The actuator according to any one of claims 1 to 3, wherein the restricting member is provided so as to collide with a portion located distal to a rotation center axis of the movable plate.   5. The at least one pair of the regulating members is provided so as to be positioned on opposite sides with respect to a rotation center axis of the movable plate in a plan view of the movable plate. Actuator.   The actuator according to any one of claims 1 to 5, wherein at least one pair of the regulating members is provided so as to be positioned on opposite sides of the movable plate.   The actuator according to claim 5 or 6, wherein a separation distance between each regulating member and a rotation center axis of the movable plate is substantially equal to each other.   The actuator according to claim 7, further comprising a voltage applying unit that applies a sawtooth AC voltage to the magnetic field generation unit.   The actuator according to any one of claims 1 to 8, wherein a light reflecting portion having light reflectivity is provided on one plate surface of the movable plate.   The actuator according to claim 9, wherein at least one pair of the restricting members is provided so as to be positioned on a surface side of the movable plate opposite to the light reflecting portion. A rotatable movable plate provided with a light reflecting portion having light reflectivity;
An accessory joined to the movable plate;
Provided so as to face the plate face of the movable plate, and at least one regulating member for regulating the behavior of the movable plate by colliding with the movable plate or the previous SL with genus product,
The accessory is at least one permanent magnet magnetized in the thickness direction of the movable plate, and the restricting member includes a magnetic field generating unit that generates a magnetic field acting on the permanent magnet, and the movable plate or the An optical scanner comprising: a buffer portion at a portion where the permanent magnet collides, and configured to rotate the movable plate by the operation of the magnetic field generating portion. A rotatable movable plate provided with a light reflecting portion having light reflectivity;
An accessory joined to the movable plate;
Provided so as to face the plate face of the movable plate, and at least one regulating member for regulating the behavior of the movable plate by colliding with the movable plate or the previous SL with genus product,
The accessory is at least one permanent magnet magnetized in the thickness direction of the movable plate, and the restricting member includes a magnetic field generating unit that generates a magnetic field acting on the permanent magnet, and the movable plate or the An image forming apparatus, comprising: a buffer portion at a portion where the permanent magnet collides, and an optical scanner configured to rotate the movable plate by the operation of the magnetic field generating portion.

Images