JP5482015B2 - 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).
Patent Document 1 discloses an actuator having an insulating substrate and a scanner main body supported by the insulating substrate. The scanner main body has a frame-shaped outer movable plate and an inner movable plate provided inside the outer movable plate. In addition, the outer movable plate and the inner movable plate are each provided with a coil, and each of the outer movable plate and the inner movable plate is configured to rotate by supplying electric power to each coil. That is, the actuator of Patent Document 1 is an electromagnetic drive type actuator.

  In such an actuator of Patent Document 1, a bonding pad electrically connected to the coil by wire bonding is provided on the surface of the insulating substrate on the actuator side, and the connector protrudes to the outside on the opposite side. By providing pins and electrically connecting them through conductor posts provided so as to penetrate the insulating substrate, power can be supplied to each coil from a power supply provided outside the actuator. It is configured.

  Here, in such an actuator, the optical scanner body is usually housed in an airtight manner. As a result, it is possible to achieve stable driving of the optical scanner main body or to prevent dust and the like from adhering to the optical scanner by reducing the pressure in the confidential space or filling a rare gas such as argon. It can be prevented. Therefore, in the actuator of Patent Document 1, in order to make the space in which the optical scanner main body is provided an airtight space, a recess (a space in which the optical scanner is provided) formed by an insulating substrate and a frame-shaped yoke is formed. It is conceivable to provide a window such as a glass substrate so as to close the opening.

  However, in the actuator of Patent Document 1, in order to electrically connect the coil provided in the optical scanner body to the power supply outside the apparatus, the connector pins and the conductor posts as described above are formed. A gap communicating between the inside and outside of the actuator is easily formed between the insulating substrate and the conductor post, and the airtightness of the space in which the optical scanner is provided cannot be ensured.

JP-A-8-322227

  An object of the present invention is to provide an actuator, an optical scanner, and an image forming apparatus that can ensure airtightness of an internal space (a space in which a movable plate is provided).

Such an object is achieved by the present invention described below.
The actuator of the present invention includes a package having a wall portion defining an internal space,
A movable plate rotatably accommodated in the internal space;
A magnet provided on one surface side of the movable plate;
A drive coil that is embedded in the wall so as not to be exposed to the internal space, faces the magnet or the magnet is located inside, and drives the movable plate to rotate.
And a pair of soft magnetic bodies arranged to face each other in the thickness direction of the movable plate via the driving coil .
Thereby, the actuator which can ensure the airtightness of internal space (space in which the movable plate is provided) can be provided.

In the actuator of the present invention, it is preferable to have a behavior detecting coil for detecting the behavior of the movable plate .
This makes it possible to detect the behavior of the variable dynamic plate.

In the actuator according to the aspect of the invention, it is preferable that the behavior detection coil is provided closer to the movable plate than the driving coil.
As a result, the drive coil and the behavior detection coil can be arranged closer to each other while being insulated from each other. Therefore, the package (actuator) can be downsized.

In the actuator according to the aspect of the invention, it is preferable that in the thickness direction of the movable plate, the driving coil is provided such that the innermost circumference gradually increases in a direction approaching the movable plate.
Thereby, the magnetic field generated from the driving coil can be efficiently applied to the magnet. Therefore, the movable plate can be smoothly rotated and the actuator can be driven to save power.

In the actuator of the present invention, the package has a box-shaped main body and a window provided so as to cover the opening of the main body, the coil is embedded in the main body, It is preferable that it is composed of low-temperature fired ceramics.
Thereby, a coil can be easily embed | buried under a main body. That is, the manufacturing of the actuator can be simplified.

An optical scanner of the present invention includes a package having a wall portion defining an internal space,
A movable plate having a light reflecting portion having light reflectivity on one surface side and rotatably accommodated in the internal space;
A magnet provided on the surface of the movable plate opposite to the light reflecting portion;
A drive coil that is embedded in the wall so as not to be exposed to the internal space, faces the magnet or the magnet is located inside, and drives the movable plate to rotate.
And a pair of soft magnetic bodies arranged to face each other in the thickness direction of the movable plate via the driving coil .
Thereby, the optical scanner which can ensure the airtightness of internal space (space in which the movable plate is provided) can be provided.

An image forming apparatus of the present invention includes a package having a wall portion that defines an internal space;
A movable plate having a light reflecting portion having light reflectivity on one surface side and rotatably accommodated in the internal space;
A magnet provided on the surface of the movable plate opposite to the light reflecting portion;
A drive coil that is embedded in the wall so as not to be exposed to the internal space, faces the magnet or the magnet is located inside, and drives the movable plate to rotate.
And an optical scanner having a pair of soft magnetic bodies arranged to face each other in the thickness direction of the movable plate via the driving coil .
Accordingly, it is possible to provide an image forming apparatus including an optical scanner that can ensure the airtightness of the internal space (the space in which the movable plate is provided).

It is sectional drawing which shows suitable embodiment of the actuator of this invention. FIG. 2 is a plan view of a vibrating body included in the actuator shown in FIG. 1. It is a top view of the actuator shown in FIG. It is sectional drawing which shows the magnetic field which the drive coil with which the actuator shown in FIG. It is sectional drawing explaining the drive of the actuator shown in FIG. It is sectional drawing explaining the manufacturing method of the actuator shown in FIG. It is sectional drawing explaining the manufacturing method of the actuator shown in FIG. It is sectional drawing explaining the manufacturing method of the actuator shown in FIG. It is sectional drawing which shows 2nd Embodiment of the actuator of this invention. It is sectional drawing which shows 3rd Embodiment of the actuator of this invention. It is sectional drawing which shows 4th Embodiment of the actuator of this invention. It is sectional drawing which shows 5th Embodiment of the actuator of this invention. It is sectional drawing which shows 6th Embodiment of the actuator of this invention. 1 is a schematic diagram illustrating a configuration of an image forming apparatus of the present invention.

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 cross-sectional view showing a preferred embodiment of the actuator of the present invention, FIG. 2 is a plan view of a vibrating body provided in the actuator shown in FIG. 1, FIG. 3 is a plan view of the actuator shown in FIG. 1 is a cross-sectional view showing a magnetic field generated by a drive coil included in the actuator shown in FIG. 1, FIG. 5 is a cross-sectional view explaining driving of the actuator shown in FIG. 1, and FIGS. It is sectional drawing explaining the manufacturing method of the actuator shown. In the following, for convenience of explanation, the upper side in FIGS. 1 and 4 to 8 is referred to as “upper”, and the lower side is referred to as “lower”. In FIGS. 3 and 4, some components are not shown for convenience of explanation.

As shown in FIG. 1, the actuator 1 includes a package 2, a vibrating body 3 housed in the package 2, a driving unit 4 that drives the vibrating body 3, and a behavior detecting unit 5 that detects the behavior of the vibrating body 3. have.
As shown in FIG. 2, the vibrating body 3 includes a frame-shaped support portion 31, a movable plate 32 provided inside the support portion 31, and a pair of connection portions 33 that connect the support portion 31 and the movable plate 32. , 34.

The movable plate 32 has a plate shape. Moreover, the planar view shape of the movable plate 32 is a circle. The planar view shape of the movable plate 32 is not particularly limited, and may be, for example, an ellipse, a rectangle, or an irregular shape.
A light reflecting portion 321 having light reflectivity is formed on the upper surface of the movable plate 32 (the surface on the window portion 22 side of the package 2 described later). Thereby, the actuator 1 can be used as an optical scanner as described later.

On the other hand, a permanent magnet (magnet) 41 is provided on the lower surface of the movable plate 32 (the surface on the drive coil 42 side described later). Such a movable plate 32 is supported at both ends by the support portion 31 by a pair of connecting portions 33 and 34.
Each of the pair of connecting portions 33 and 34 has a longitudinal shape (bar shape) and can be elastically deformed. Further, the pair of connecting portions 33 and 34 are provided to face each other with the movable plate 32 interposed therebetween. Such a pair of connecting portions 33 and 34 connects the movable plate 32 and the support portion 31 so that the movable plate 32 can be rotated with respect to the support portion 31. The pair of connecting portions 33 and 34 are provided coaxially with each other, and the movable plate 32 is connected to the pair of connecting portions 33 around this axis (hereinafter also referred to as “rotation center axis X”). , 34 is rotated with respect to the support portion 31 while being torsionally deformed.

Such a vibrating body 3 is made of, for example, silicon as a main material, and the support portion 31, the movable plate 32, and the connection portions 33 and 34 are integrally formed. By using silicon as a main material, 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.
Such a vibrating body 3 is accommodated in the package 2.

As shown in FIG. 1, the package 2 includes a main body 21 in which a concave portion 211 is formed, and a window portion 22 provided so as to cover the concave portion 211.
The concave portion 211 formed in the main body 21 functions as a housing space for housing the above-described vibrating body 3. As shown in FIG. 1, the recessed part 211 is comprised by the 1st recessed part 211a and the 2nd recessed part 211b whose opening area is smaller than the 1st recessed part 211a.

  The first recess 211a is formed so as to open on the upper surface (surface on the window portion 22 side) of the main body 21, and the second recess 211b is opened at the center of the bottom surface of the first recess 211a. Is formed. In this manner, by forming the two concave portions 211a and 211b having different sizes, the step portion 211c can be formed in the middle of the concave portion 211 in the depth direction. By fixing the support portion 31 of the vibrating body 3 to such a stepped portion 211c, the vibrating body 3 can be accommodated in the recessed portion 211 in a state where the movable plate 32 is rotatable.

  From the above viewpoint, it is preferable that the shape of the first recess 211a in plan view (opening shape) is a similar shape having a size larger than the outer shape of the support portion 31 of the vibrating body 3. On the other hand, the shape of the second recess 211b in plan view is similar to the inner shape of the support portion 31 of the vibrating body 3 or slightly larger in size, or the movable plate 32 and the connecting portions 33 and 34. It is preferable to have a similar shape that is slightly larger in size than the outer shape. Thereby, the recessed part 211 which can accommodate the vibrating body 3 inside and can support the vibrating body 3 reliably can be easily formed in the main body 21.

  Such a main body 21 is made of, for example, low-temperature fired ceramics (LTCC). As will be described later, the drive coil 42 and the behavior detection coil 51 are embedded in the main body 21. However, the drive coil 42 can be easily attached to the main body 21 by forming the main body 21 from low-temperature fired ceramics. And the behavior detecting coil 51 can be embedded. That is, the manufacturing of the actuator 1 can be simplified by configuring the main body 21 with low-temperature fired ceramics. An example of a method for manufacturing the main body 21 (a method for embedding the drive coil 42 and the behavior detection coil 51) will be described later.

  The window 22 has a plate shape and is provided so as to cover the opening of the recess 211 formed in the main body 21. Such a window portion 22 is made of glass such as Tempax glass or Pyrex glass ("Pyrex" is a registered trademark), and is substantially colorless and transparent (that is, has light transmittance). ) As a result, light emitted from a light source (for example, a light source device 91 described later) provided outside the actuator 1 is incident on the package 2 through the window 22, and the incident light is movable by the vibrating body 3. The light reflected and reflected by the light reflecting portion 321 provided on the plate 32 can be guided to the outside of the package through the window portion 22.

The main body 21 and the window portion 22 can be joined as follows, for example. That is, when the main body 21 is made of low-temperature fired ceramics and the window portion 22 is made of glass such as Tempax glass or Pyrex glass ("Pyrex" is a registered trademark), as shown in FIG. The bonding film 23 made of silicon is provided between the window 21 and the window 22, and the main body 21 and the bonding film 23 are anodically bonded, and the window 22 and the bonding film 23 are anodically bonded, whereby the main body 21 and the window portion 22 can be bonded via the bonding film 23. For example, the bonding film 23 can be formed on the upper surface of the main body 21 by sputtering or the like. In this case, the main body 21 with the silicon film and the window portion 22 can be anodically bonded.
According to such a joining method, the main body 21 and the window part 22 can be joined easily and reliably, and the internal space S (accommodating space) can be brought into an airtight state. Moreover, since such a joining method can be easily performed in a reduced pressure atmosphere or a rare gas atmosphere, the internal space S of the package 2 can be easily brought into a reduced pressure state or a rare gas filling state. .

The drive unit 4 is a unit for rotating the movable plate 32 of the vibrating body 3 about the rotation center axis X. Such a drive means 4 has a permanent magnet 41 and a drive coil (coil) 42.
As shown in FIGS. 1 and 2, the permanent magnet 41 is provided on the lower surface of the movable plate 32 (surface opposite to the light reflecting portion 321). Thereby, it can prevent that the optical scanning in the light reflection part 321 will be inhibited by the permanent magnet 41. FIG. The permanent magnet 41 is fixed to the movable plate 32 via an adhesive, for example.

The permanent magnet 41 has a longitudinal shape and is magnetized in the longitudinal direction. Such a permanent magnet 41 is provided so as to extend in a direction orthogonal to the rotation center axis X. That is, the permanent magnet 41 is provided on the movable plate 32 so that one side of the rotation center axis X is an S pole and the other side is an N pole.
Such a permanent magnet 41 is not particularly limited, and for example, a magnet made of a hard magnetic material such as a neodymium magnet, a ferrite magnet, a samarium cobalt magnet, an alnico magnet, or a bonded magnet can be suitably used.

  The driving coil 42 is provided on the lower side (directly below) of the permanent magnet 41 so as to face the permanent magnet 41. That is, the drive coil 42 is provided so that a magnetic field generated by energization can act on the permanent magnet 41 and the movable plate 32 can be rotated. Further, as shown in FIG. 3, the driving coil 42 is permanent in a plan view of the movable plate 32 in a non-driven state (the state shown in FIG. 1) (hereinafter, also simply referred to as “plan view of the movable plate 32”). It is provided so as to include the magnet 41. By providing the drive coil 42 in this way, the magnetic field generated by the drive coil 42 can be efficiently applied to the permanent magnet 41, so that the movable plate 32 can be smoothly rotated.

  As shown in FIG. 1, the drive coil 42 is embedded in the main body 21 of the package 2. In other words, the drive coil 42 is embedded in a wall portion that defines the internal space S of the package 2. Further, the driving coil 42 is not exposed to the internal space S. As described above, by embedding the driving coil 42 in the main body 21 of the package 2, the following effects can be exhibited. That is, conventionally, since the driving coil is provided in the housing space of the package, the inside and outside of the package are communicated with the main body of the package in order to electrically connect the power source outside the package and the driving coil. In addition to forming a through hole (through hole), it was necessary to form a conductor post in the formed through hole, and to electrically connect the power source and the driving coil via the conductor post.

However, in such a method, there is a problem that a gap that communicates the inside and outside of the package is easily formed between the conductor post and the package body, and the airtightness of the internal space of the package cannot be secured. .
On the other hand, in the actuator 1 of the present embodiment, since the driving coil 42 is embedded in the main body 21 of the package 2 (that is, not provided in the internal space S), the conventional package 2 It is not necessary to form a through hole that communicates the inside and outside of the housing. Therefore, the airtightness of the internal space S of the package 2 can be reliably ensured.

  In addition, since the drive coil 42 is embedded in the main body 21 of the package 2, heat generated by energization of the drive coil 42 when driving the actuator 1 as described later is transmitted to the vibrating body 3. It can be effectively suppressed. Thereby, since thermal expansion of the vibrating body 3 is suppressed, the actuator 1 can exhibit desired vibration characteristics for a long time.

  Note that both ends of the drive coil 42 are exposed from the bottom surface 212 of the main body 21 to the outside of the package 2 (not shown), for example. A power source (not shown) that supplies power to the driving coil 42 is provided outside the package 2, and the driving coil 42 is electrically connected to the power source through the exposed portions (both ends). Has been. In addition, you may use the power supply which the apparatus by which the actuator 1 is mounted has as said power supply.

Such driving means 4 rotates the movable plate 32 as follows.
First, AC power is supplied from the power source to the driving coil 42. As a result, as shown in FIG. 4A, the drive coil 42 generates a first magnetic field having an N pole on the upper side (permanent magnet 41 side) and an S pole on the lower side (opposite side of the permanent magnet 41). The state in which the driving coil 42 generates a second magnetic field with the S pole on the upper side and the N pole on the lower side as shown in FIG. 4B occurs alternately and periodically.

In the first magnetic field, since the permanent magnet 41 side is the S pole, as shown in FIG. 5A, the N pole side of the permanent magnet 41 is attracted to the driving coil 42, and on the contrary, the S pole side is the driving coil 42. The movable plate 32 rotates clockwise about the rotation center axis X so as to move away from the center (first state).
On the contrary, in the second magnetic field, since the permanent magnet 41 side is N-pole, as shown in FIG. 5B, the S-pole side of the permanent magnet 41 is attracted to the driving coil 42, and on the contrary, the N-pole side is driven. The movable plate 32 rotates counterclockwise about the rotation center axis X so as to move away from the coil 42 (second state).
The movable plate 32 rotates about the rotation center axis X by alternately repeating the first state and the second state.

  The behavior detection unit 5 is a unit that detects the behavior of the movable plate 32 of the vibrating body 3. Such behavior detection means 5 includes a permanent magnet 41, a behavior detection coil 51, and an induced power measurement unit (galvanometer) (not shown). Such behavior detecting means 5 is configured to detect the behavior of the movable plate 32 based on the periodic change of the induced power generated by the behavior detecting coil 51 by the action of the permanent magnet 41.

  The behavior detecting coil 51 is provided on the upper side of the driving coil 42 while being insulated from the driving coil 42. Thus, by providing the behavior detecting coil 51 on the upper side of the driving coil 42, the distance between the behavior detecting coil 51 and the permanent magnet 41 can be shortened. Therefore, the induced power generated by the behavior detection coil can be increased, and the behavior of the movable plate 32 can be accurately detected.

The behavior detecting coil 51 is provided coaxially with the driving coil 42. As a result, the drive coil 42 and the behavior detection coil 51 can be arranged closer to each other in a state of being insulated from each other. Therefore, the package 2 (actuator 1) can be downsized.
Further, the behavior detection coil 51 is provided so that the permanent magnet 41 is positioned inside thereof. Furthermore, the behavior detecting coil 51 is provided so that the center thereof coincides with the center of the permanent magnet 41 in the thickness direction of the movable plate 32 in the non-driven state (that is, the vertical direction in FIG. 1). . As a result, as will be described later, the induced power generated by the behavior detecting coil 51 due to the rotation of the movable plate 32 becomes larger, so that the behavior of the movable plate 32 can be detected more accurately.

Such a behavior detection coil 51 is embedded in the main body 21 of the package 2. In other words, the behavior detection coil 51 is embedded in a wall portion that defines the internal space S of the package 2. Further, the behavior detection coil 51 is not exposed to the internal space S. Thus, by embedding the behavior detecting coil 51 in the main body 21 of the package 2, the same effect as that of embedding the driving coil 42 in the main body 21 can be exhibited. That is, in the actuator 1, since the behavior detecting coil 51 is embedded in the main body 21 of the package 2 (that is, not provided in the internal space S), the penetration through the inside and outside of the package 2 as in the conventional case is performed. There is no need to form holes. Therefore, the airtightness of the internal space S of the package 2 can be reliably ensured.
Both ends of the behavior detecting coil 51 are exposed from the bottom surface 212 of the main body 21 to the outside of the package 2 (not shown), for example. The induced power measuring unit is provided outside the package 2, and the behavior detecting coil 51 is electrically connected to the induced power measuring unit through the exposed portions (both ends). .

Such behavior detection means 5 detects the behavior of the movable plate 32 as follows.
The behavior detecting coil 51 generates an induced power by the magnetic field of the permanent magnet 41. Since the value of the induced power generated by the behavior detecting coil 51 changes periodically with the rotation of the movable plate 32 (the rotation of the permanent magnet 41 associated therewith), the periodically changing induced power is set to The behavior of the movable plate 32 is detected based on the value (magnitude) of the measured induced power measured by the induced power measurement unit. Thereby, the behavior of the movable plate 32 can be detected accurately.

  In particular, in the embodiment, the permanent magnet 41 is provided so as to be positioned inside the behavior detecting coil 51 in the non-driven state of the actuator 1 (in the thickness direction of the movable plate 32 in the non-driven state, Since the permanent magnet 41 is provided so that the center thereof coincides with the center of the behavior detecting coil 51), when the rotational speed of the movable plate 32 becomes the fastest, the permanent magnet 41 becomes the behavior detecting coil 51. The closest to. Therefore, the induced power generated by the behavior detection coil 51 becomes larger. Thereby, the behavior of the movable plate 32 can be detected more accurately.

The actuator 1 as described above can be manufactured as follows, for example.
6 to 8 are views for explaining a method of manufacturing the actuator 1. In the following, for convenience of explanation, the upper side in FIGS. 6 to 8 is referred to as “upper” and the lower side is referred to as “lower”. FIG. 6 is a diagram corresponding to a cross-sectional view taken along line AA in FIG.

[Formation process of vibrator 3]
First, as shown in FIG. 6A, a silicon substrate 100 for forming the vibrating body 3 is prepared. Then, as shown in FIG. 6B, a resist mask M having a shape corresponding to the planar view shape of the support portion 31, the movable plate 32 and the pair of connecting portions 33 and 34 is formed on the upper surface of the silicon substrate 100. .

Next, the silicon substrate 100 is etched through the resist mask M. Thereafter, the resist mask M is removed. Thereby, as shown in FIG.6 (c), the silicon substrate 100 in which the support part 31, the movable plate 32, and a pair of connection parts 33 and 34 were formed integrally is obtained.
As the etching method, for example, one or more of physical etching methods such as plasma etching, reactive ion etching, beam etching, and light-assisted etching, and chemical etching methods such as wet etching are combined. Can be used. Note that the same method can be used for etching in the following steps.

Next, as shown in FIG. 6 (d), a metal film is formed on the upper surface of the movable plate 32 to form a light reflecting portion 321. Thereby, the vibrating body 3 is obtained. The method of forming the metal film is not particularly limited, and is a vacuum plating, sputtering (low temperature sputtering), dry plating methods such as ion plating, wet plating methods such as electrolytic plating and electroless plating, thermal spraying methods, joining metal foils. Etc.
Next, as shown in FIG. 6E, the permanent magnet 41 is fixed to the lower surface of the movable plate 32 via an adhesive. In addition, it is good also as the permanent magnet 41 by fixing a hard magnetic body to the lower surface of the movable plate 32 via an adhesive agent, and magnetizing this hard magnetic body after that.

[Package 2 Formation Process]
The window portion 22 of the package 2 is obtained by processing a plate-like member made of glass such as Tempax glass or Pyrex glass (“Pyrex” is a registered trademark) into a predetermined size.
On the other hand, the main body 21 of the package 2 is obtained as follows.
The main body 21 can be manufactured by the same method as that for manufacturing a low-temperature fired ceramic multilayer substrate. That is, the main body 21 laminates a first step of forming a plurality of green sheets 61, a second step of forming the conductive pattern P on each green sheet 61, and a plurality of green sheets 61 on which the conductive patterns P are formed. Thus, the third step of forming the laminate 6 and the fourth step of firing the laminate 6 can be performed in order.

(First step)
First, a glass ceramic composition containing glass ceramic powder and a binder is slurried with a dispersion medium, and this is applied onto a carrier film to form a coating film. Next, the green sheet 61 is obtained by drying the coating film. As shown in FIG. 7A, in this step, a plurality of such green sheets 61 are prepared. In addition, as a dispersion medium, surfactant, a silane coupling agent, etc. can be used, for example, What is necessary is just to disperse | distribute glass ceramic powder uniformly. Moreover, it does not specifically limit as a method of forming a coating film on a carrier film, Various sheet forming methods, such as a doctor blade method and a reverse roll coater method, can be used.

As the glass ceramic powder, for example, a glass composite ceramic in which a borosilicate glass is mixed with a ceramic powder such as alumina or forsterite can be used. The average particle diameter of such glass ceramic powder is not particularly limited, but is preferably about 0.1 μm or more and 5 μm or less. As the glass ceramic powder, a crystallized glass ceramic using a crystallized glass of ZnO—MgO—Al ₂ O ₃ —SiO ₂ type, BaO—Al ₂ O ₃ —SiO ₂ type ceramic powder, Al ₂ O ₃ — Non-glass ceramics using CaO—SiO ₂ —MgO—B ₂ O ₃ ceramic powder or the like may be used.

  As the binder, an organic polymer that functions as a binder for the glass ceramic powder and can be easily removed in the fourth step is suitably used. As such a binder, for example, a binder resin such as butyral, acrylic or cellulose can be used. As the acrylic binder resin, for example, a homopolymer of a (meth) acrylate compound such as alkyl (meth) acrylate, alkoxyalkyl (meth) acrylate, polyalkylene glycol (meth) acrylate, cycloalkyl (meth) acrylate, or the like is used. Can do. The binder may contain a plasticizer such as an adipate ester plasticizer, dioctyl phthalate (DOP), dibutyl phthalate (DBP) phthalate ester plasticizer, or a glycol ester plasticizer.

Here, as shown in FIG. 7A, the plurality of green sheets 61 obtained by the above-described method includes three types of green sheets 61a, 61b, and 61c having different shapes. The three types of green sheets 61a, 61b, and 61c have the same outer shape (plan view shape), but are different in the following points.
That is, an opening (hole) 611a is formed through the center of the green sheet 61a, and an opening 611b having a smaller opening area than the opening 611a is formed through the green sheet 61b. The green sheet 61c is not formed with the openings as described above. The opening 611a formed in the green sheet 61a is an opening for forming the first recess 211a of the main body 21, and the opening 611b formed in the green sheet 61b forms the second recess 211b of the main body 21. It is an opening for.
Three types of green sheets 61a, 61b, and 61c having different shapes are prepared, and the green sheets 61a, 61b, and 61c are stacked in this order from the upper side. can do.

(Second step)
Next, the conductive pattern P and the conductor post that will be the driving coil 42 and the behavior detecting coil 51 are formed on the green sheet 61.
Specifically, among the plurality of green sheets 61 obtained in the first step, a via hole (not shown) having a hole diameter of about several tens of μm to several hundreds of μm is formed on the necessary green sheet 61 by punching or laser processing. (Circular hole, conical hole) is formed through. Next, the via hole formed in the green sheet is filled with a conductive paste of metal powder such as silver, gold, copper or the like by various printing methods such as screen printing to form a conductor post, and the green sheet 61 A conductor paste is applied to the surface of the substrate to form a conductor layer.

  Next, a photoresist is applied to the surface of the conductor layer, and a resist film is formed on the surface of the conductor layer by exposing and developing to a predetermined pattern. Next, the conductor layer is etched through this resist film, and the resist film is removed, whereby a green sheet 61 having a conductive pattern P formed on the surface is obtained as shown in FIG. 7B. As described above, the conductor post and the conductive pattern formed on the green sheet 61 constitute a part of the drive coil 42 or the behavior detection coil 51, and thus the drive coil 42 and the behavior detection coil 51. Corresponding to the wiring pattern, conductor posts and conductive patterns are formed on the necessary green sheet 61.

(Third step)
In this step, a plurality of green sheets 61 are stacked to form a stacked body.
Specifically, a plurality of green sheets 61 are sequentially stacked in the order shown in FIG. That is, in FIG. 7B, the green sheet (second layer green sheet) 61 located on the uppermost side is positioned in a state where the lowermost green sheet (first layer green sheet) 61 is positioned by a rigid member (not shown). A green sheet 61 is laminated on the first green sheet 61. Thereafter, similarly, a plurality of green sheets 61 are sequentially laminated to form a laminate 6 of green sheets 61 containing the conductive pattern P. In addition, when laminating | stacking the some green sheet 61, the laminated body 6 more integrated can be obtained by performing a heating and pressurization.

(4th process)
Next, the laminate 6 is placed in a high-temperature firing furnace and sintered. The firing temperature is, for example, 800 ° C. to 900 ° C., and is appropriately changed according to the composition of the green sheet 61. When Cu is used as the conductive pattern P, it is preferably fired in a reducing atmosphere to prevent oxidation. When silver, gold or the like is used, it may be fired in the air.

As a result, as shown in FIG. 8A, the main body 21 is obtained which is composed of a low-temperature fired ceramic multilayer substrate and in which the drive coil 42 and the behavior detection coil 51 are embedded. According to such a manufacturing method, the main body 21 in which the driving coil 42 and the behavior detecting coil 51 are embedded can be easily manufactured.
After the main body 21 is obtained, a bonding film 23 made of silicon is formed on the upper surface of the main body 21 by sputtering or the like.

[Step of housing vibrator 3 in package 2]
Next, the vibrating body 3 is fixed to the main body 21 of the package 2. Specifically, as shown in FIG. 8B, the support portion 31 of the vibrating body 3 is fixed (joined) to the step portion 211 c of the main body of the package 2. The fixing of the support portion 31 to the stepped portion 211c may be performed using, for example, an adhesive or anodic bonding.

Next, the window portion 22 is placed on the upper surface of the main body 21 so as to cover the opening of the main body 21, and the bonding film 23 and the main body 21, and the bonding film 23 and the window portion 22 are bonded by anodic bonding. As a result, the main body 21 and the window portion 22 are joined, and an internal space S having airtightness is formed inside the package 2.
Note that, for example, the internal space S can be brought into a reduced pressure state by performing this step under a reduced pressure, and the inner space S can be brought into a rare gas filling state by being performed in a rare gas atmosphere. it can. In what environment (atmosphere) this process is performed can be appropriately selected according to the characteristics required of the actuator 1.
Through the above steps, the actuator 1 is obtained as shown in FIG.

Second Embodiment
Next, a second embodiment of the actuator of the present invention will be described.
FIG. 9 is a 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. 9 is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.

Hereinafter, the actuator 1 of the second embodiment will be described with a focus on differences from the actuator of the above-described embodiment, and description of similar matters will be omitted.
The actuator 1 according to the second embodiment of the present invention is substantially the same as the actuator 1 of the first embodiment except that the behavior detecting means 5 is omitted. In FIG. 9, the same components as those in the first embodiment described above are denoted by the same reference numerals.

That is, in the actuator 1 of the present embodiment, only the driving coil 42 is embedded in the main body 21 of the package 2. Further, the driving coil 42 is provided so that at least a part of the permanent magnet 41 (in this embodiment, the lower part of the permanent magnet 41) is positioned inside the actuator 1 when the actuator 1 is in a non-driven state. Yes. It is more preferable to provide the driving coil 42 so that the entire permanent magnet 41 is located inside the driving coil 42. Thus, by providing the driving coil 42 so that a part or all of the permanent magnet 41 is located inside the driving coil 42, the magnetic field generated by the driving coil 42 by energization is caused by the permanent magnet 41. It can work efficiently.
Also by such 2nd Embodiment, the effect similar to 1st Embodiment can be exhibited.

<Third Embodiment>
Next, a third embodiment of the actuator of the present invention will be described.
FIG. 10 is a 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. 10 is referred to as “upper” and the lower side is referred to as “lower”.
Hereinafter, the actuator 1 according to the third embodiment will be described focusing on the differences from the actuator according to the above-described embodiment, and description of similar matters will be omitted.
The actuator 1 according to the third embodiment of the present invention is substantially the same as the actuator 1 of the second embodiment described above except that the shape of the second recess 211b and the shape of the driving coil 42 are different. In FIG. 10, the same reference numerals are given to the same configurations as those in the above-described embodiment.

  As shown in FIG. 10, the drive coil 42 has an innermost circumference (cross-sectional area of the internal space) that gradually increases as it approaches the permanent magnet 41 in the vertical direction of the paper (in the thickness direction of the movable plate 32). Has a tapered shape. Furthermore, in the cross section (ie, the cross section shown in FIG. 10) in the plane that intersects the center of the movable plate 32 and is orthogonal to the rotation center axis X, the innermost circumference of the drive coil 42 is the rotation of the movable plate 32. It is formed so as to follow an arcuate locus R drawn by the end of the movable plate 32 when moving. In other words, the drive coil 42 is formed so that its innermost circumference is along an arc having a radius slightly larger than the radius of the movable plate 32 with the rotation center axis X as the center.

  By forming the driving coil 42 in such a shape, the magnetic field generated by the driving coil 42 can be efficiently applied to the permanent magnet 41 provided on the movable plate 32. More specifically, the attitude of the permanent magnet 41 changes with the rotation of the movable plate 32, but the driving coil 42 is shaped as described above, regardless of the attitude of the permanent magnet 41 ( The magnetic field generated from the driving coil 42 can be efficiently applied to the permanent magnet 41 during the rotation of the movable plate 32. Therefore, the movable plate 32 can be smoothly rotated and the actuator 1 can be driven to save power.

As shown in FIG. 10, the second recess 211b has a taper shape in which the cross-sectional area gradually increases from the opening toward the bottom (bottom surface). Further, in the cross section in the plane intersecting the center of the movable plate 32 and orthogonal to the rotation center axis X (that is, the cross section shown in FIG. 10), the side surface of the second recess 211 b is the rotation of the movable plate 32. At this time, it is formed so as to follow an arcuate locus R drawn by the end of the movable plate 32. That is, the second recess 211 b has a shape corresponding to the shape of the drive coil 42. Thus, by making the shape of the second recess 211 b correspond to the shape of the driving coil 42, a sufficient space for embedding the driving coil 42 can be secured in the main body 21. That is, the drive coil 42 can be reliably embedded in the main body 21 of the package 2 while preventing the actuator 1 from becoming large.
According to the third embodiment, the same effect as that of the first embodiment can be exhibited.

<Fourth embodiment>
Next, a fourth embodiment of the actuator of the present invention will be described.
FIG. 11 is a cross-sectional view showing a fourth embodiment of the actuator of the present invention. In the following, for convenience of explanation, the upper side in FIG. 11 is referred to as “upper” and the lower side is referred to as “lower”.
Hereinafter, the actuator 1 according to the fourth embodiment will be described focusing on the differences from the actuator according to the above-described embodiment, and description of similar matters will be omitted.
The actuator 1 according to the fourth embodiment of the present invention is substantially the same as the actuator of the second embodiment described above except that the soft magnetic bodies 43 and 44 are embedded in the main body 21 of the package 2. In FIG. 11, the same reference numerals are given to the same configurations as those in the above-described embodiment.

  As shown in FIG. 11, the actuator 1 of this embodiment has a pair of soft magnetic bodies 43 and 44 embedded in the main body 21 of the package 2. The pair of soft magnetic bodies 43 and 44 have a function of guiding magnetic lines of force (magnetic flux) generated by the driving coil 42 when energized. By providing such soft magnetic bodies 43 and 44, the strength of the magnetic field (magnetic field as shown in FIG. 4) generated by the drive coil 42 can be increased, and thus the movable plate 32 is smoothly rotated. In addition, the actuator 1 can be driven to save power.

  In particular, in this embodiment, since the pair of soft magnetic bodies 43 and 44 are embedded in the main body 21, the space of the main body 21 can be used effectively, and the pair of soft magnetic bodies 43 and 44 are used for driving. It can be provided closer to the coil 42. Therefore, the strength of the magnetic field (magnetic field as shown in FIG. 4) generated by the drive coil 42 by energization can be increased while reducing the size of the actuator 1.

  The soft magnetic body 43 has a plate shape and is provided below the driving coil 42. On the other hand, the soft magnetic body 44 has a frame shape surrounding the second recess 211b, and is provided on the upper side of the drive coil. That is, the pair of soft magnetic bodies 43 and 44 are provided so as to face each other with the driving coil 42 interposed therebetween. Thus, by providing the pair of soft magnetic bodies 43 and 44 so as to oppose each other via the driving coil 42, the lines of magnetic force (magnetic flux) generated by the driving coil 42 by energization can be more efficiently guided. The strength of the magnetic field (magnetic field as shown in FIG. 4) generated by the drive coil 42 can be further increased. Therefore, the movable plate 32 can be smoothly rotated and the actuator 1 can be driven to save power.

The soft magnetic bodies 43 and 44 are each composed of a soft magnetic material as a main material. Such a soft magnetic material is not particularly limited, and examples thereof include Fe and various Fe alloys (silicon iron, permalloy, amorphous, sendust) and the like.
According to the fourth embodiment, the same effect as that of the first embodiment can be exhibited.

<Fifth Embodiment>
Next, a fifth embodiment of the actuator of the present invention will be described.
FIG. 12 is a sectional view showing a fifth embodiment of the actuator of the present invention. In the following, for convenience of explanation, the upper side in FIG. 12 is referred to as “upper” and the lower side is referred to as “lower”.
Hereinafter, the actuator 1 according to the fifth embodiment will be described focusing on the differences from the actuator according to the above-described embodiment, and description of similar matters will be omitted.
The actuator 1 according to the fifth embodiment of the present invention is substantially the same as the actuator of the second embodiment described above, except that the soft magnetic body 45 is embedded in the internal space S of the package 2. In FIG. 12, the same reference numerals are given to the same configurations as those in the above-described embodiment.

As shown in FIG. 12, the actuator 1 of this embodiment has a soft magnetic body 45 provided in the internal space S of the package 2. The soft magnetic body 45 has a function as a magnetic core that increases the magnetic force generated by the drive coil 42 when energized.
The soft magnetic body 45 has a plate shape and is provided on the bottom surface of the second recess 211b. Further, the soft magnetic body 45 is located inside the driving coil 42. By providing such a soft magnetic body 45, the magnetic lines of force (magnetic flux) generated by the drive coil 42 when energized can be more efficiently guided, and the magnetic field generated by the drive coil 42 (as shown in FIG. 4). The strength of the magnetic field can be further increased. Therefore, the movable plate 32 can be smoothly rotated and the actuator 1 can be driven to save power.
Further, by providing the soft magnetic body 45 in the internal space S of the package 2, it is not necessary to embed the soft magnetic body 45 in the main body 21 of the package 2 as in the above-described fourth embodiment, and the actuator 1 can be manufactured. It can also be simplified.

The soft magnetic body 45 is composed of a soft magnetic material as a main material. Such a soft magnetic material is not particularly limited, and examples thereof include Fe and various Fe alloys (silicon iron, permalloy, amorphous, sendust) and the like.
According to the fifth embodiment, the same effect as that of the first embodiment can be exhibited.

<Sixth Embodiment>
Next, a sixth embodiment of the actuator of the present invention will be described.
FIG. 13 is a sectional view showing a sixth embodiment of the actuator of the present invention. In the following, for convenience of explanation, the upper side in FIG. 13 is referred to as “upper” and the lower side is referred to as “lower”.
Hereinafter, the actuator 1 according to the fifth embodiment will be described focusing on the differences from the actuator according to the above-described embodiment, and description of similar matters will be omitted.
The actuator 1 according to the fifth embodiment of the present invention is substantially the same as the actuator of the first embodiment described above except that the arrangement of the drive coil 42 is different. In FIG. 13, the same components as those in the above-described embodiment are denoted by the same reference numerals.

As shown in FIG. 13, in the actuator 1 of this embodiment, the drive coil 42 is provided outside the package 2. Specifically, the drive coil 42 is provided on the bottom surface 212 of the main body 21 of the package 2.
Also according to the sixth embodiment, the same effect as that of the first embodiment can be exhibited.

  Since the actuator as described above includes a light reflecting portion on the movable plate, for example, MEMS application sensors such as an acceleration sensor and an angular velocity sensor, a laser printer, a barcode reader, a scanning confocal laser microscope, and an imaging sensor. It can be used for optical devices such as optical scanners, optical switches, and optical attenuators provided in image forming apparatuses such as displays.

  The optical scanner of the present invention has the same configuration as the actuator of the present invention except that the movable plate is provided with a light reflecting portion. The embodiment of the optical scanner of the present invention is the same as that of the above-described embodiment, and detailed description thereof is omitted. Such an 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, a projector 9 as shown in FIG. 14 will be described. For convenience of explanation, the longitudinal direction of the screen SC is referred to as “lateral direction”, and the direction perpendicular to the longitudinal direction is referred to as “vertical direction”.
The projector 9 includes a light source device 91 that emits light such as a laser, a cross dichroic prism 92, and a pair of optical scanners 93 and 94 according to the present invention (for example, the same configuration as the actuator 1 of each of the embodiments described above). An optical scanner) and a fixed mirror 95.

The light source device 91 includes a red light source device 911 that emits red light, a blue light source device 912 that emits blue light, and a green light source device 913 that emits green light.
The cross dichroic prism 92 is configured by bonding four right-angle prisms, and is an optical element that combines light emitted from each of the red light source device 911, the blue light source device 912, and the green light source device 913.

  Such a projector 9 combines light emitted from each of the red light source device 911, the blue light source device 912, and the green light source device 913 based on image information from a host computer (not shown) by a cross dichroic prism 92, The synthesized light is scanned by the optical scanners 93 and 94, and further reflected by the fixed mirror 95, so that a color image is formed on the screen SC.

Here, the optical scanning of the optical scanners 93 and 94 will be specifically described.
First, the light combined by the cross dichroic prism 92 is scanned in the horizontal direction by the optical scanner 93 (main scanning). The light scanned in the horizontal direction is further scanned in the vertical direction by the optical scanner 94 (sub-scanning). Thereby, a two-dimensional color image can be formed on the screen SC. By using the optical scanner of the present invention as the optical scanners 93 and 94, extremely excellent drawing characteristics can be exhibited.
However, the projector 9 is not limited to this as long as it is configured to scan light with an optical scanner and form an image on an object. For example, the fixed mirror 95 may be omitted.

  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. Further, for example, in the actuator, the optical scanner, and the image forming apparatus of the present invention, the above-described embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 1 ... Actuator 2 ... Package 21 ... Main body 211 ... Recessed part 211a ... 1st recessed part 211b ... 2nd recessed part 211c ... Step part 212 ... Bottom 22 ... Window part 23 ... Bonding film 3 …… Vibrating body 31 …… Supporting portion 32 …… Moving plate 321 …… Light reflecting portion 33, 34 …… Connecting portion 4 …… Drive means 41 …… Permanent magnet 42 …… Drive coils 43, 44, 45 …… Soft magnetic material 5... Behavior detection means 51... Behavior detection coil 6. Laminated body 61, 61 a, 61 b, 61 c... Green sheet 611 a, 611 b ...... Opening 9 …… Projector 91 …… Light source device 911 …… Red light source device 912 …… Blue light source device 913 …… Green light source device 92 …… Cross dichroic prism 93, 94 …… Optical scanner 95 …… Fixed mirror 100 …… Silicone substrate M …… Resist mask S …… Internal space SC …… Screen P …… Conductive pattern R …… Track X …… Rotation center axis

Claims (7)

A package having a wall defining an internal space;
A movable plate rotatably accommodated in the internal space;
A magnet provided on one surface side of the movable plate;
A drive coil that is embedded in the wall so as not to be exposed to the internal space, faces the magnet or the magnet is located inside, and drives the movable plate to rotate.
An actuator comprising: a pair of soft magnetic bodies arranged to face each other in the thickness direction of the movable plate via the driving coil . The actuator according to claim 1 , further comprising a behavior detection coil for detecting the behavior of the movable plate . The actuator according to claim 2 , wherein the behavior detection coil is provided closer to the movable plate than the driving coil. 4. The drive coil according to claim 1 , wherein the innermost circumference of the drive coil is gradually increased in a direction approaching the movable plate in the thickness direction of the movable plate. 5. Actuator. The package has a box-shaped main body and a window provided so as to cover the opening of the main body, the coil is embedded in the main body, and the main body is made of low-temperature fired ceramics. The actuator according to any one of claims 1 to 4 . A package having a wall defining an internal space;
A movable plate having a light reflecting portion having light reflectivity on one surface side and rotatably accommodated in the internal space;
A magnet provided on the surface of the movable plate opposite to the light reflecting portion;
A drive coil that is embedded in the wall so as not to be exposed to the internal space, faces the magnet or the magnet is located inside, and drives the movable plate to rotate.
An optical scanner , comprising: a pair of soft magnetic bodies arranged to face each other in the thickness direction of the movable plate via the driving coil . A package having a wall defining an internal space;
A movable plate having a light reflecting portion having light reflectivity on one surface side and rotatably accommodated in the internal space;
A magnet provided on the surface of the movable plate opposite to the light reflecting portion;
A drive coil that is embedded in the wall so as not to be exposed to the internal space, faces the magnet or the magnet is located inside, and drives the movable plate to rotate.
An image forming apparatus comprising: an optical scanner having a pair of soft magnetic bodies arranged to face each other in the thickness direction of the movable plate via the driving coil .

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