JP2021081484A - Drive device and drive method - Google Patents

Abstract

To provide a drive device that can generate high driving force, and can achieve a large oscillation angle.SOLUTION: A drive device 100 comprises: a first rotating body 23; a second rotating body 22 that is arranged outside the first rotating body 23, and supports the first rotating body 23 rotatably around a first rotation axis AX1; a supporting body 21 that supports the second rotating body 23 rotatably around a second rotation axis AX2; a circuit CK that includes, on the second rotating body 22, a first and second coils CO1 and CO2 facing each other across a crossing point CP, and a third and fourth coils CO3 and CO4 facing each other across the crossing point CP, being arranged in each area on the same flat surface divided into four parts by the first and second rotation axes AX1 and AX2 around the crossing point CP of the first and second rotation axes AX1 and AX2; electromagnetic field giving means 12 that gives to each of the coils CO1 to CO4 an electromagnetic field in a direction parallel with a coil surface CS. A first drive signal S1 is applied to each of the coils CO1 to CO4 in a positive phase, a second drive signal S2 is applied to the first and second coils CO1 and CO2 in the positive phase, and to the third and fourth coils CO3 and CO4 in a reverse phase.SELECTED DRAWING: Figure 1

Description

The present invention relates to a drive device and a drive method used for optical scanning, and more particularly to a drive device and the like in which a coil is formed in a movable portion to apply a magnetic field.

As the driving device for optical scanning, for example, as shown in Patent Documents 1 and 2 (see the prior art document section below), in order from the outside, a support which is a fixed outer frame and an outer rotating body which is also called a movable inner frame. And an inner rotating body, which is also called a movable plate, the inner rotating body is rotatably supported around the first rotating shaft, and the outer rotating body is rotatably supported around the second rotating shaft. Is known.

As shown in FIG. 7A, in the apparatus of Patent Document 1, a coil CR2 is formed on the upper surface of the outer rotating body RB2 of the inner and outer rotating bodies RB1 and RB2. In this device, two components having different frequencies are applied to the coil CR2 from the outside of the coil CR2 provided on the outer rotating body RB2 while applying a magnetic field MF in a direction parallel to the diagonal direction between the two rotating shafts RX1 and RX2. By supplying the including drive signal, the outer rotating body RB2 is periodically rotated around the second rotating shaft RX2, and the inner rotating body RB1 is periodically rotated around the first rotating shaft RX1. As a result, the mirror MR formed on the inner rotating body RB1 can be periodically reciprocated around the two rotation axes RX1 and RX2, enabling biaxial scanning of the mirror MR.

As shown in FIGS. 8A to 8C, in the apparatus of Patent Document 2, two coil circuits CK1 and CK2 are separately formed on the front and back sides in the outer rotating body RB2. Specifically, on the front side of the outer rotating body RB2, a pair of connected coils CE11 and CE12 are distributed and arranged at one diagonal position as the coil circuit CK1 (see FIG. 8A), and the outer side. On the back side of the rotating body RB2, a pair of connected coils CE21 and CE22 are distributed and arranged at the other diagonal positions as another coil circuit CK2 (see FIG. 8B). In this device, by supplying a drive signal to the coil circuits CK1 and CK2, detailed description will be omitted, but the mirror MR formed on the inner rotating body RB1 is cycled around the two rotating shafts RX1 and RX2. It is explained that it can be rotated back and forth.

However, the devices of Patent Documents 1 and 2 have problems as described below.

With reference to FIG. 7A, in the apparatus of Patent Document 1, since the magnet (not shown) for applying the magnetic field MF is arranged apart from the outside of the support SF, the magnetic flux density is increased at the position of the coil CR2. It decreases and the drive efficiency deteriorates. Further, since the inclined magnetic field MF is applied to both of the rotating shafts RX1 and RX2, the driving efficiency is deteriorated. Further, for example, even if the rotation is restricted by the torsion arm TB2 that reciprocally supports the rotating body RB2, the rotating body is given a rotational force around the diagonal axis tilted with respect to the rotating shafts RX1 and RX2. There is also a problem that the RB2 rotates slightly in the regulated direction and the trajectory of optical scanning is distorted into, for example, a parallelogram.

With reference to FIGS. 7 (B) and 7 (C), distortion of the trajectory of optical scanning in the apparatus of Patent Document 1 will be described. As shown in FIG. 7B, for example, the outer rotating body RB2 is given a rotational force around the diagonal axis SX tilted with respect to the respective rotating axes RX1 and RX2. More specifically, an upward force F perpendicular to the paper surface is generated at the upper end portion of the coil CR2 along the paper surface, and a downward force F perpendicular to the paper surface is generated at the lower end portion of the coil CR2 along the paper surface. A rotational force is generated around the rotating shaft RX2. Further, an upward force FC perpendicular to the paper surface is generated at the right end portion along the paper surface of the coil CR2, and a downward force FC perpendicular to the paper surface is generated at the left end portion along the paper surface of the coil CR2. A rotational force is generated around. Here, as shown in FIG. 7C, rotation around the rotation axis RX2 is allowed up to a predetermined deflection angle according to the rotational force by the torsion arm TB2, but rotation around the rotation axis RX1 is allowed. It is regulated by the torsion arm TB2. However, the rotational force around the rotation shaft RX1 slightly deforms the torsion arm TB2 because the force FC changes at a relatively low speed. As a result, the rotating body RB2 reciprocates around the rotating shaft RX2 with a large amplitude RM2 and reciprocates around the rotating shaft RX1 with a small amplitude RM1. Here, the large rotation of the rotating body RB2 around the rotating shaft RX2 and the small rotation around the rotating shaft RX1 are synchronized. Therefore, the locus of the reflected light by the mirror MR is not strictly parallel to the rotation axis RX1 and is slightly tilted toward the rotation axis RX2 with respect to the rotation axis RX1. When high-speed rotation due to resonance around the rotation axis RX1 of the moving body RB1 is also taken into consideration, the locus of the reflected light by the mirror MR has a distortion like a parallel quadrilateral as a whole. As shown in FIG. 7B, the two pairs of force FCs near the center of the rotation axis RX2 indicated by the one-point chain line rotate in opposite directions with the rotation axis RX2 in between, and the torsion arm TB2 as described above. Is slightly deformed, but it is canceled out as the moment of force and is not used as the rotational force. That is, in the case of the above-mentioned device, there is a problem that the driving efficiency is deteriorated as a result of applying the inclined magnetic field MF to the rotation axes RX1 and RX2. In FIGS. 7 (B) and 7 (C), the rotating body RB2 and the coil CR2 are represented in a rectangular shape for convenience of explanation, but the same phenomenon occurs even if the rotating body RB2 or the like is circular.

As shown in FIGS. 8 (A) to 8 (C), in the apparatus of Patent Document 2, the direction of the magnetic field MF is perpendicular to the coil surfaces of the coils CE11, CE12, CE21, and CE22, and therefore, for example, the coil CE11 is exemplified. As described above, the driving force (Lorentz force) Ff according to Fleming's left-hand rule is formed in the horizontal direction parallel to the coil surface and in the direction parallel to the rotation axes RX1 and RX2. When considering the rotation around RX2, it is not along the circumferential direction or the tangential direction that causes such rotation, and the generated force is also canceled by the entire coil and does not become a force in a specific direction. The interaction between the magnetic field formed by the coil CE11 or the like according to Ampere's law and the magnetic field MF formed by the permanent magnet PM can generate a force in the direction perpendicular to the coil surface with respect to the coil CE11 or the like. , It is not easy to obtain a large driving force by this. The magnetic flux is canceled between the adjacent currents, and as a result, the driving force in the direction perpendicular to the coil surface is canceled in principle, so that the rotational force around the rotating shafts RX1 and RX2 is insufficient, which will be described later. Unintended translational forces may occur. If a large driving force or rotational force cannot be obtained as described above, it is necessary to rely on resonance in order to realize a large rotation angle, and the signal supplied to the coil corresponds to the resonance frequency of the rotating body. It has to be a periodic signal. Further, there is a problem that the rotating body cannot be driven by an aperiodic signal (a DC component added as a bias, which will be described later). Further, since the magnetic pole PMa of the permanent magnet PM faces the coils CE11, CE12, CE21, CE22 and the rotating bodies RB1 and RB2 to limit the operation, there is a problem that a large swing angle cannot be realized for the rotating bodies RB1 and RB2.

In the device of Patent Document 2, the pair of coils CE11 and CE12 and the other pair of coil elements CE21 and CE22 are not arranged in the same plane, and the asymmetry of the force around the rotation axes RX1 and RX2 is caused. As a result, translational force is generated, which may cause unnecessary vibration. The force applied to the outer rotating body RB2 will be described in detail with reference to FIGS. 8 (D) and 8 (E). When a downward driving force F is applied to one upper coil CE11 and an upward driving force F is applied to the other upper coil CE12 in the rotating body RB2, an upward driving force F is applied to the lower one coil CE21. A force F'(> F) is applied, and a downward driving force F'(> F) is applied to the other coil CE22 on the lower side. The strength of the magnetic field MF in the coils CE11 and CE12 is such that the coils CE11 and CE12 are located farther from the magnetic pole PMa of the permanent magnet PM than the coils CE21 and CE22 as compared with the strength of the magnetic field MF in the coils CE21 and CE22. Because of this, it is relatively weak, and there is a difference in driving force F, F'. When considering the rotational force around the rotating shaft RX2, the driving forces F and F'give a counterclockwise rotational force to the rotating body RB2. However, the forces F and F'applied to the coils CE11, CE12, CE21 and CE22 are not along the circumferential direction or the tangential direction of rotation, and the forces in the circumferential direction among the driving forces F and F'. The components Fr and Fr'contribute to rotation, but the radial force components Ft and Ft'do not contribute to rotation. However, for example, with respect to the upper coils CE11 and CE12, a translational force Ftt toward the right side of the paper surface (anti-AB direction) is given to the rotating body RB2 due to the resultant force of the force component Ft in the radial direction, and the lower coil. With respect to CE21 and CE22, a translational force Ftb toward the left side of the paper surface (AB direction) is given to the rotating body RB2 due to the resultant force of the force component Ft'in the radial direction. The two translational forces Ftt and Ftb have a magnitude relation Ftt <Ftb proportional to the above two driving forces F and F'of different magnitudes, and while being partially balanced and canceling each other, translation toward the AB direction. The force Ftb-Ftt remains, and such translational force or unnecessary force may cause unintended vibration.

Special Table 2007-522259 Japanese Unexamined Patent Publication No. 2008-203497

The present invention has been made in view of the above background technology, and provides a drive device and a drive method that have good drive efficiency, can suppress the occurrence of trajectory distortion and unnecessary vibration, and can realize a large swing angle. The purpose is to provide.

In order to achieve the above object, the drive device according to the present invention has a first rotating body and a second rotating body that is arranged outside the first rotating body and rotatably supports the first rotating body around the first rotating shaft. A rotating body, a support that rotatably supports the second rotating body around the second rotating shaft, and first and second rotations on the second rotating body around the intersection of the first and second rotating shafts. For each coil and a circuit including the first and second coils arranged in each region on the same plane divided into four by an axis and facing each other across the intersection, and the third and fourth coils facing each other across the intersection. The first drive signal is applied to each coil in the positive phase, and the second drive signal is applied to the first and second coils in the positive phase, the third and the third. It is applied to the fourth coil in opposite phase.

In the above drive device, a rotational force can be generated around the second rotation axis by the first drive signal applied to each coil in the positive phase, and the first and second coils have the third and fourth in the positive phase. A rotational force can be generated around the first rotary shaft by the second drive signal applied to the coil in opposite phase. At this time, the force applied to each coil by the first drive signal can be used without waste as the rotational force around the second rotation shaft, and the force applied to each coil by the second drive signal can be used on the first rotation shaft. It can be used without waste as the surrounding rotational force, and as a result, it is possible to avoid applying the rotational force around the diagonal axis that is tilted with respect to both rotation axes, and not only the drive efficiency is good, but also the distortion is small. A scanning locus can be realized. Moreover, since each coil is arranged on the same plane, the driving force applied to the coil is along the circumferential direction or the tangential direction of rotation about the first or second rotation axis. All of the driving force contributes to the rotation without waste, and it is possible to surely suppress the generation of unnecessary vibration due to the translational force or the unnecessary force that does not contribute to the rotation (see FIG. 4 (E) described later). Further, by applying a magnetic field in a direction parallel to the coil surface by the magnetic field applying means, a large force can be generated in a direction perpendicular to the coil surface, and a large swing angle can be realized.

A specific aspect of the present invention includes a drive unit that outputs a first drive signal and a second drive signal. In this case, the drive device is an integrated device or module in which a drive unit is added to the scanner of the main body.

In another aspect of the present invention, the magnetic field applying means applies a magnetic field toward one of the inside and outside in common with the first to fourth coils, and the first and second coils have a counterclockwise current applied to the first coil. When flowing, it is connected so that a clockwise current flows through the second coil, and the third and fourth coils are connected so that a clockwise current flows through the fourth coil when a counterclockwise current flows through the third coil. Is connected to. In this case, the magnetic field is formed in a common direction with respect to the inside and outside of the coil. As a result, it becomes easy to generate a couple around the second rotation shaft by the first drive signal, and it becomes easy to generate a couple around the first rotation shaft by the second drive signal.

In yet another aspect of the present invention, the first and second coils are connected by a first wire formed on the central annular portion of the second rotating body arranged around the first rotating body, and the third and second coils are connected. The fourth coil is connected by a second wiring formed on the central annular portion. In this case, the central annular portion serves as a support for the first and second wirings. The first to fourth coils are arranged on the outer periphery of the central annular portion.

In yet another aspect of the invention, the second rotating body has four peripheral annular portions on which the first to fourth coils are formed on the surface. In this case, if a peripheral annular portion is provided on the second rotating body, the first to fourth coils can be supported by the peripheral annular portion, and magnetic poles are arranged inside and outside the peripheral annular portion, the second rotating body can be supported. It is possible to prevent the magnetic field applying means from interfering with the rotational operation.

In yet another aspect of the invention, the support rotatably supports the second rotating body around the second rotating shaft via the second torsion bar, and the second rotating body is the first rotating body. Is twistably rotatably supported around the first rotation axis via the first torsion bar. In this case, the outer second rotating body is supported by the support and reciprocates around the second rotating shaft extending along the second torsion bar, and the inner first rotating body is supported by the second rotating body. It reciprocates around a first axis of rotation that extends along the first torsion bar.

In yet another aspect of the present invention, the first rotating body rotates around the first rotating shaft in a resonance period, and the second rotating body follows the force applied to the first to fourth coils and is second. It reciprocates around the axis of rotation. That is, the first rotating body rotates in a resonance cycle, and the second rotating body reciprocates following the clockwise and counterclockwise rotational forces applied around the first rotating shaft. The second rotating body can be forcibly and non-resonantly rotated when it is rotated around the second rotating shaft by using the force applied to the first to fourth coils, and it also resonates. It can also be rotated in a cycle. The operation of rotating the second rotating body non-resonantly includes an operation of periodically rotating the second rotating body and an operation of repeatedly rotating the second rotating body aperiodically. By rotating the second rotating body not only periodically but also non-periodically, the degree of freedom of the operation pattern of the second rotating body 22 is increased, and the use of the drive device can be expanded.

In order to achieve the above object, the driving method according to the present invention includes a second rotating body which is arranged outside the first rotating body and rotatably supports the first rotating body around the first rotating shaft, and a second rotating body. A support that rotatably supports the rotating body around the second rotating shaft, and four divisions on the second rotating body by the first and second rotating shafts around the intersection of the first and second rotating shafts. For each coil, the drive device is arranged in each region on the same plane and includes a circuit including a first and second coils facing each other across the intersection and a third and fourth coils facing each other across the intersection. A magnetic field is applied in the direction parallel to the coil surface, the first drive signal is applied to each coil in the positive phase, and the second drive signal is in the positive phase to the first and second coils and in the opposite phase to the third and fourth coils. It is applied.

In the above driving method, the first driving signal can generate a rotational force around the second rotating shaft, and the second driving signal can generate a rotational force around the first rotating shaft. At this time, the force applied to each coil by the first drive signal can be used without waste as the rotational force around the second rotation shaft, and the force applied to each coil by the second drive signal can be used on the first rotation shaft. It can be used without waste as the surrounding rotational force, and as a result, it is possible to avoid applying the rotational force around the diagonal axis that is tilted with respect to both rotation axes, and not only the drive efficiency is good, but also the distortion is small. A scanning locus can be realized. Moreover, since each coil is arranged on the same plane, the driving force applied to the coil is along the circumferential direction or the tangential direction of rotation about the first or second rotation axis. All of the driving force contributes to the rotation without waste, and it is possible to surely suppress the generation of unnecessary vibration due to the translational force or the unnecessary force that does not contribute to the rotation. Further, by applying a magnetic field in a direction parallel to the coil surface by the magnetic field applying means, a large force can be generated in the direction perpendicular to the coil surface with respect to each coil, and a large swing is applied to the rotating body supporting each coil. The horn can be realized.

It is a top view explaining the drive device of 1st Embodiment. (A) and (B) are AA cross-sectional views and BB cross-sectional views of FIG. 1 for explaining a scanner, and (C) is a partial cross-sectional view for explaining a magnetic field former of a modified example. (A) and (B) are diagrams for explaining the switching of the driving force direction by changing the direction of the electric current. (A) and (B) are diagrams conceptually explaining the switching of the driving force around the second rotating shaft, and (C) and (D) are the switching of the driving force around the first rotating shaft. (E) is a diagram conceptually explaining that the force applied to the second rotating body becomes a couple around the rotation axis and is not wasted. (A) is a block diagram for explaining a specific example of a circuit configuration of a drive unit, and (B) is a low-speed side drive signal (first drive signal) supplied to the first and second coil systems in the positive phase. (C) indicates a high-speed side drive signal (second drive signal) supplied to the first coil system in the positive phase and supplied to the second coil system in the opposite phase. (A) and (B) are conceptual partially enlarged cross-sectional views for explaining the operation of the driving device by showing the magnetic field, the current and the driving force acting on the coil, and (C) is the device of the comparative example. It is a figure explaining operation. (A) is a perspective view for explaining the structure of the apparatus of Patent Document 1, and (B) and (C) are conceptual plan views and perspective views for explaining the distortion of the trajectory of optical scanning. (A) is a plan view for explaining the structure of the device of Patent Document 2, (B) is a back view for explaining the structure of the device of Patent Document 2, and (C) is (A) and (C). It is CC'cross-sectional view of the apparatus shown in B). (D) and (E) are conceptual diagrams for explaining the force applied to the outer rotating body in the device of Patent Document 2.

Hereinafter, a driving device and a driving method for optical scanning according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the drive device 100 of the present embodiment includes a scanner 10 including a movable mechanism and a drive unit 80 including an electronic circuit. The drive device 100 is an integrated device or module in which a circuit-like drive unit 80 is added to the scanner 10 of the main body.

The scanner 10 is an electromagnetically driven actuator having a leaf spring structure that can rotate or tilt in two axes. The scanner 10 operates by receiving an electric signal from the drive unit 80, which is a drive circuit. The scanner 10 includes a scanner main body 11 manufactured by processing a silicon substrate or other semiconductor substrate, and magnetic field applying means for applying a magnetic field in a predetermined direction to a predetermined portion of the scanner main body 11, and includes magnetic field formers MG1 to MG4. A magnetic field forming unit 12 and a support substrate 13 that supports the periphery of the scanner body 11 from below are provided. The scanner body 11 is not limited to the semiconductor substrate, but can also be manufactured by wet etching processing of beryllium copper, stainless steel or other metals, sheet metal punching processing, or the like.

As shown in FIGS. 1 and 2 (A) and 2 (B), the scanner main body 11 includes a first rotating body 23, a second rotating body 22, and a support 21 in this order from the inside. The first rotating body 23 is also referred to as an inner movable portion, the second rotating body 22 is also referred to as an outer movable portion, and the support 21 is also referred to as a base portion.

In the scanner main body 11, the outermost support 21 has a rectangular frame-shaped outer shape and is fixed on the support substrate 13. The second rotating body 22, which is an outer movable portion, is arranged so as to fit within the opening 21a of the support 21, has a rectangular outer shape, and is rotatably supported by the support 21. More specifically, the second rotating body 22 has a rectangular frame-shaped central annular portion 22b, and has four peripheral annular portions 22d outside the central annular portion 22b. A pair of second torsion bars 32a and 32b extending in the X direction are provided between the support 21 and the second rotating body 22 so as to be around the second rotating shaft AX2 of the second rotating body 22. Allow rotation or tilt. That is, the support 21 supports the second rotating body 22 so as to be twistably rotatable around the second rotating shaft AX2 via the second torsion bars 32a and 32b. The second torsion bars 32a and 32b extend along the second rotation axis AX2. The first rotating body 23, which is an inner movable portion, is arranged so as to fit in the opening 22a formed in the central annular portion 22b of the second rotating body 22, has an oval outer shape, and has an oval outer shape with respect to the second rotating body 22. It is rotatably supported. A pair of first torsion bars 31a and 31b extending in the Y direction are provided between the second rotating body 22 and the first rotating body 23, and the first rotating shaft AX1 of the first rotating body 23 is provided. Allow rotation or tilt around. That is, the second rotating body 22 supports the first rotating body 23 so as to be twistably rotatable around the first rotating shaft AX1 via the first torsion bars 31a and 31b. The first torsion bars 31a and 31b extend along the first rotation axis AX1. In the above, the first rotation axis AX1 and the second rotation axis AX2 are orthogonal to each other and form an angle of 90 °. However, the first rotation axis AX1 and the second rotation axis AX2 may intersect at an angle other than 90 °. The mirror 24 formed on the first rotating body 23 is driven by the driving unit 80 to change its posture together with the first rotating body 23, and reflects the incident laser light or the like in the direction corresponding to the posture.

The support 21 supports the second rotating body 22 in a state of being movable around the second rotating shaft AX2, and the second rotating body 22 supports the first rotating body 23 in a state of being movable around the first rotating shaft AX1. As a result, the first rotating body 23 or the mirror 24 formed on the surface thereof becomes rotatable or tiltable around the first rotating shaft AX1 and the second rotating shaft AX2, and the mirror 24 becomes two-dimensional. Scanning becomes possible.

The first rotating body 23 and the second rotating body 22 have symmetrical shapes with respect to the first and second rotating shafts AX1 and AX2. That is, the central annular portion 22b constituting the second rotating body 22 has a symmetrical shape with respect to the first and second rotating axes AX1 and AX2, and the four peripheral annular portions 22d have the same size as each other. And, they are arranged symmetrically with respect to the first and second rotation axes AX1 and AX2. It is not essential that the shapes of the first rotating body 23 and the second rotating body 22 are symmetrical with respect to the first and second rotating shafts AX1 and AX2. That is, the shapes of the first rotating body 23 and the second rotating body 22 may be asymmetric with respect to the first and second rotating shafts AX1 and AX2, and in this case as well, the rotating bodies 23 and 22 are subjected to the desired rotational operation. Can be done.

The second rotating body 22, which is an outer movable portion, supports the first to fourth coils CO1 to CO4 on the surface of one side of the peripheral annular portions 22d provided at the four corners of the rectangular contour thereof. That is, the first to fourth coils CO1 to CO4 are arranged on the outer side around the central annular portion 22b, and are supported by the peripheral annular portion 22d provided on the outer side of the central annular portion 22b. The first to fourth coils CO1 to CO4 are 4 on the upper side surface of the second rotating body 22 by the first and second rotating shafts AX1 and AX2 around the intersection CP of the first and second rotating shafts AX1 and AX2. It is divided into four regions R1 to R4 on the same plane that are divided and arranged. Here, the first and second coils CO1 and CO2 face each other with the intersection CP sandwiched between them, and the third and fourth coils CO3 and CO4 face each other with the intersection CP sandwiched between them. Specifically, the first coil CO1 is arranged in the region R1 of the first quadrant in the upper right of FIG. 1, the second coil CO2 is arranged in the region R2 of the third quadrant in the lower left, and the third coil CO3 is The fourth coil CO4 is arranged in the upper left second quadrant region R3, and the fourth coil CO4 is arranged in the lower right fourth quadrant region R4. At the four corners of the second rotating body 22, the peripheral annular portions 22d are formed with the first to fourth peripheral openings OP1 to OP4, and the first to fourth coils CO1 to CO4 are the first to fourth peripheral openings OP1. It is arranged around the first to fourth peripheral openings OP1 to OP4 so as to surround ~ OP4. The centers C1 to C4 of the first to fourth coils CO1 to CO4 substantially coincide with the centers of the first to fourth peripheral openings OP1 to OP4.

The first coil CO1 and the second coil CO2 are connected to each other to form the first coil system CS1. The third coil CO3 and the fourth coil CO4 are connected to each other to form the second coil system CS2. In the scanner main body 11, the combination of the first coil system CS1 and the second coil system CS2 is called a circuit CK. The circuit CK includes the first to fourth coils CO1 to CO4.

The first coil system CS1 includes a first feeder line 41a, a first coil CO1, a first wiring 42a, a second coil CO2, and a second feeder line 43a from the positive electrode side. The first power feeding line 41a electrically connects the first terminal TA1 and one end of the first coil CO1, and the first wiring 42a is formed on the central annular portion 22b that functions as a support for the first wiring 42a. The other end of the first coil CO1 and one end of the second coil CO2 are connected, and the second feeding line 43a electrically connects the other end of the second coil CO2 and the second terminal TA2. Here, referring to FIG. 3A, the first coil CO1 is wound counterclockwise, the second coil CO2 is wound clockwise, and the first terminal TA1 is wound with respect to the second terminal TA2. When the potential is relatively positive, the counterclockwise current I11 flows through the first coil CO1, the clockwise current I12 flows through the second coil CO2, and the driving forces F11 and F12 corresponding to the Lorentz force are the respective coil CO1s. , Given to CO2. That is, as will be described in detail later, in the first and second coils CO1 and CO2, under a predetermined magnetic field H1 and H2, the driving force aligned clockwise around the second rotation axis AX2 in the + X direction is applied. appear.

Returning to FIG. 1 and the like, the second coil system CS2 has a third feeder line 41b, a fourth coil CO4, a second wiring 42b, a third coil CO3, and a fourth feeder line 43b from the positive electrode side. Including. The third power feeding line 41b electrically connects the third terminal TA3 and one end of the fourth coil CO4, and the second wiring 42b is formed on the central annular portion 22b that functions as a support for the second wiring 42b. The other end of the fourth coil CO4 and one end of the third coil CO3 are electrically connected, and the fourth feeding line 43b electrically connects the other end of the third coil CO3 and the fourth terminal TA4. .. Here, referring to FIG. 3A, the fourth coil CO4 is wound clockwise, the third coil CO3 is wound counterclockwise, and the third terminal TA3 is wound with respect to the fourth terminal TA4. When the potential is relatively positive, the clockwise current I14 flows through the fourth coil CO4, the counterclockwise current I13 flows through the third coil CO3, and the driving forces F13 and F14 corresponding to the Lorentz force are the respective coil CO3s. , Given to CO4. That is, as will be described in detail later, in the third and fourth coils CO3 and CO4, under a predetermined magnetic field H3 and H4, the driving force aligned clockwise around the second rotation axis AX2 in the + X direction is applied. appear. As described above, in the first and second coil systems CS1 and CS2 coils, the coils CO1 to CO4 are connected to the crosspiece so as to intersect diagonally. Further, each coil CO1 to CO4 has a structure in which a tunnel type wiring material (thin film conductor) is embedded in an insulating layer in order to enable three-dimensional connection.

The state of FIG. 3 (B) is the one in which the direction of the current is reversed with respect to the state of FIG. 3 (A). That is, when the first terminal TA1 has a relatively negative potential, a clockwise current I21 flows through the first coil CO1, a counterclockwise current I22 flows through the second coil CO2, and the coils CO1 and CO2 are driven. Forces F21 and F22 are applied. Further, when the third terminal TA3 has a relatively negative potential, a counterclockwise current I24 flows through the fourth coil CO4, a clockwise current I23 flows through the third coil CO3, and the coils CO3 and CO4 are driven. Forces F23 and F24 are applied.

The driving forces F11 and F13 and the driving forces F12 and F14 include equal forces applied to the two sides of each of the rectangular coils CO1 to CO4. Strictly speaking, when considering the rotational force applied to the second rotating body 22 and the like, it is necessary to consider the torsional moment or torque in consideration of the distance from the second rotating shaft AX2 at the action position of the driving forces F11 to F14. However, in the illustrated example, since the coils CO1 to CO4 are symmetrically arranged with the second rotation axis AX2 in between, the same result can be obtained with respect to the rotation operation even if the coils are treated as a mere force instead of a torsional moment. Even in the following, when a symmetrical arrangement around the axis is premised, the rotational operation may be described as a mere force instead of a torsional moment for the sake of simplicity.

In the above, the coils CO1 to CO4 are arranged on the same plane parallel to the XY plane, and are on the plane defined by the first and second rotation axes AX1 and AX2. Therefore, if the absolute values of the driving forces F11 to F14 and the absolute values of the driving forces F21 to F24 are equal, it is possible to generate a lean rotational force around the second rotating shaft AX2 with respect to the second rotating body 22. In addition, it is possible to reliably suppress the generation of unnecessary vibration due to the translational force that does not contribute to rotation.

Returning to FIG. 1, the magnetic field forming unit (magnetic field applying means) 12 includes first to fourth magnetic field forming devices MG1 to MG4 corresponding to the first to fourth coils CO1 to CO4. The first to fourth magnetic field formers MG1 to MG4 apply a magnetic field substantially parallel to the coil surfaces of the first to fourth coils CO1 to CO4 at the positions of the first to fourth coils CO1 to CO4.

As shown in FIGS. 2A and 2B, the first magnetic field former MG1 is curved outside the first coil CO1 and formed between the second rotating body 22 and the support 21. It has a first magnetic pole 51 arranged in the gap portion G1. Further, the first magnetic field former MG1 has a second magnetic pole 52 which is inside the first coil CO1 and is arranged in the first peripheral opening OP1. The first magnetic pole 51 corresponds to the north pole portion 53a of the first magnet 53 for the outside, and the second magnetic pole 52 corresponds to the south pole portion 54a of the second magnet 54 for the inside. The first magnet 53 and the second magnet 54 are supported on the support substrate 13 by the yoke 55 to form a magnetic circuit. The first magnetic field former MG1 forms a magnetic field H1 in the first coil CO1 that is parallel to the coil surface of the first coil CO1 and crosses the first coil CO1 so as to penetrate inward. In this case, the magnetic poles 51 and 52 can be arranged in the vicinity of the first coil CO1 without limiting the movable range, and the driving force applied to the first coil CO1 can be made high and stable. That is, the first magnetic field former MG1 can generate a large force with respect to the coil CO1 in the direction perpendicular to the coil surface, and a large swing angle can be realized with a small current.

FIG. 2C is a partial cross-sectional view illustrating a modified example of the first magnetic field former MG1 shown in FIG. 2B and the like. In this case, the magnet 153 is bonded to the upper surface of the center yoke 113 that also serves as the support substrate 13, and the outer peripheral yoke 213 is bonded to the magnet 153. Of the outer peripheral yoke 213, the first magnetic pole 51 is formed in the inward projection 213a that faces the first coil CO1 from the outside and surrounds the first coil CO1. Further, a second magnetic pole 52 is formed inside the first coil CO1 and at the top of the rectangular protrusion 113a of the center yoke 113. The support 21 of the scanner body 11 is fixed on the outer peripheral yoke 213.

Returning to FIG. 1, the second magnetic field former MG2 has the same structure as the first magnetic field former MG1. That is, the second magnetic field former MG2 is located outside the second coil CO2 and inside the second coil CO2 and the first magnetic pole 51 arranged in the gap portion G2 between the second rotating body 22 and the support 21. It has a second magnetic pole 52 arranged in the second peripheral opening OP2. As shown in FIG. 3A, in the second coil CO2, the second magnetic field former MG2 crosses the second coil CO2 parallel to the coil surface of the second coil CO2 and penetrates the second coil CO2, and the magnetic field H2 goes inward. To form.

The third magnetic field former MG3 has the same structure as the first magnetic field former MG1. That is, the third magnetic field former MG3 is located outside the third coil CO3 and inside the first magnetic pole 51 arranged in the gap portion G3 between the second rotating body 22 and the support 21 and inside the third coil CO3. It has a second magnetic pole 52 arranged in the third peripheral opening OP3. As shown in FIG. 3A, the third magnetic field former MG3 has a magnetic field H3 in the third coil CO3 that is parallel to the coil surface of the third coil CO3 and crosses the third coil CO3 so as to penetrate the third coil CO3. To form.

The fourth magnetic field former MG4 has the same structure as the first magnetic field former MG1. That is, the fourth magnetic field former MG4 is located outside the fourth coil CO4 and inside the first magnetic pole 51 arranged in the gap portion G4 between the second rotating body 22 and the support 21 and inside the fourth coil CO4. It has a second magnetic pole 52 arranged in the fourth peripheral opening OP4. As shown in FIG. 3A, the fourth magnetic field former MG4 has a magnetic field H4 in the fourth coil CO4 that is parallel to the coil surface of the fourth coil CO4 and crosses the fourth coil CO4 so as to penetrate the fourth coil CO4. To form.

In the case of the magnetic field forming portion (magnetic field applying means) 12 described above, the magnetic fields H1 to H4 formed in the first to fourth coils CO1 to CO4 are formed in a common direction both inside and outside. As a result, it becomes easy to generate a couple around the second rotation axis AX2 by the currents I11 to I14 and the like shown in FIG. 3A, and although not shown, the couple is even around the first rotation axis AX1. It also makes it easier to generate force. Further, in the case of the magnetic field forming portion 12 and the second rotating body 22 described above, the peripheral annular portions 22d of the second rotating body 22 support the first to fourth coils CO1 to CO4, and the first to fourth coils CO1 to CO4 are supported inside and outside the peripheral annular portion 22d. The structure is such that the magnetic poles 51 and 52 are arranged, and it is possible to prevent the magnetic field formers MG1 to MG4 or the magnetic field forming unit 12 from interfering with the rotational operation of the second rotating body 22. That is, a large swing angle can be realized for the rotating bodies 22 and 23 that support the coils CO1 to CO4.

The support substrate 13 has a recess in the outer frame that supports the scanner body 11 and houses the first to fourth boundary formers MG1 to MG4 inside the outer frame. The support substrate 13 can be formed of a metal such as iron, aluminum, or brass, or can be formed of a resin-based material such as glass epoxy, bakelite, or PPS (polyphenylene sulfide).

FIG. 4A is a conceptual diagram illustrating the driving force corresponding to the direction of the electric current shown in FIG. 3A, and is the upper side (+ Y side) along the paper surface with respect to the second rotation axis AX2. In the 1st and 3rd coils CO1 and CO3, driving forces F1 and F3 due to Lorentz force are generated in the upward direction (+ Z side) perpendicular to the paper surface, and on the lower side (-Y side) along the paper surface with respect to the second rotation axis AX2. , The driving forces F2 and F4 by the Lorentz force are generated in the second and fourth coils CO2 and CO4 in the downward direction (−Z side) perpendicular to the paper surface. Here, when the second rotation axis AX2 is used as a reference, the driving force F1 of the first coil CO1 and the driving force F2 of the second coil CO2 have the same magnitude and the same rotation direction. The driving force F3 of the third coil CO3 and the driving force F4 of the fourth coil CO4 have the same magnitude and the same rotation direction. Further, when the second rotation axis AX2 is used as a reference, the combined force of the driving forces F1 and F3 given to the coils CO1 and CO3 and the combined force of the driving forces F2 and F4 given to the coils CO2 and CO4 are couples. Make. As a result, the second rotating body 22 supporting the coils CO1 to CO4 receives a clockwise rotational force, that is, a driving force when directed to the + X side along the second rotating shaft AX2. In this case, the driving forces F1 to F4 have the same magnitude and Z in the circumferential direction of rotation about the first rotation axis AX1 so as to form a couple around the second rotation axis AX2 (that is, Z perpendicular to the paper surface). Since it is applied in the direction parallel to the axis), the loss of the driving force is small, and it is possible to suppress the application of an unintended force to the second rotating body 22.

FIG. 4 (E) corresponds to FIG. 4 (A), and is a concept for explaining that the force applied to the second rotating body 22 becomes a symmetrical couple around the second rotating shaft AX2 and is not wasted. It is a figure. In the second rotating body 22, the coils CO1 to CO4 are arranged in the same plane parallel to the second rotating shaft AX2 (the surface along the coil surface CS), and the driving force F (driving force F) applied to the coils CO1 to CO4 ( The driving force F1 to F4 in FIG. 4A) is along the circumferential direction or the tangential direction of the rotation centered on the second rotation axis AX2, so that all of the driving force F is wasted as a couple. Contributes to rotation without.

FIG. 4B is a conceptual diagram illustrating the driving force corresponding to the direction of the electric current shown in FIG. 3B, which is the upper side (+ Y side) along the paper surface with respect to the second rotation axis AX2. In the 1st and 3rd coils CO1 and CO3, driving forces F1 and F3 due to Lorentz force are generated in the downward direction (-Z side) perpendicular to the paper surface, and the lower side (-Y side) along the paper surface with respect to the second rotation axis AX2. Then, in the second and fourth coils CO2 and CO4, the driving forces F2 and F4 by the Lorentz force are generated in the upward direction (+ Z side) perpendicular to the paper surface. Although detailed description is omitted, when the second rotation axis AX2 is used as a reference, the driving force F1 of the first coil CO1 and the driving force F2 of the second coil CO2 have the same magnitude and the same rotation direction. It is a force, and the driving force F3 of the third coil CO3 and the driving force F4 of the fourth coil CO4 have the same magnitude and the same rotation direction. As a result, the second rotating body 22 supporting the coils CO1 to CO4 receives a counterclockwise rotational force, that is, a driving force when directed to the + X side along the second rotating shaft AX2. Also in this case, the driving forces F1 to F4 have the same magnitude and are applied in the circumferential direction so as to form a couple around the second rotation axis AX2.

If the states shown in FIGS. 4 (A) and 4 (B) are alternately repeated in the forward and reverse directions, the second rotating body 22 is made to follow the force applied to the first to fourth coils CO1 to CO4, and the second rotating body 22 is made to follow the force applied to the first to fourth coils CO1 to CO4. It can be reciprocally rotated or reciprocally tilted around the rotation shaft AX2. That is, the second rotating body 22 reciprocates following the clockwise and counterclockwise rotational forces applied around the second rotating shaft AX2. At this time, the signal waveforms given to the first and second terminals TA1 and T2 and the signal waveforms given to the third and fourth terminals TA3 and T4 shown in FIG. 1 are not limited to sawtooth waves, but are triangular waves, sine waves, and other arbitrary ones. The second rotating body 22 can be reciprocally rotated around the second rotating shaft AX2 in a non-resonant manner, and the reciprocating rotation or reciprocating inclination (that is, swinging) can be obtained in various swing angle increase / decrease patterns. ) Can be made. Regarding the switching of the states shown in FIGS. 4 (A) and 4 (B), that is, the repetition of the positive state shown in FIGS. 4 (A) and 4 (B) and the reverse state in which the waveform is inverted, the forward and reverse are correct. It does not have to be symmetrical, and the amplitudes may be different in the forward and reverse directions, and the state where there is no driving force and the state shown in FIG. 4A or 4B may be switched.

4 (C) and 4 (D) show the case where the polarity of the power supply to the first coil system CS1 and the polarity of the power supply to the second coil system CS2 are reversed.

In the case of FIG. 4C, the first terminal TA1 shown in FIG. 1 has a positive potential relative to the second terminal TA2, and the third terminal TA3 has a negative potential relative to the fourth terminal TA4. There is. As a result, on the right side (+ X side) along the paper surface with respect to the first rotation axis AX1, the driving force F1 by Lorentz force is upward (+ Z side) perpendicular to the paper surface in the first and fourth coils CO1 and CO4. F4 is generated, and the driving force by Lorentz force is generated in the downward direction (-Z side) perpendicular to the paper surface in the second and third coils CO2 and CO3 on the left side (-X side) along the paper surface with respect to the first rotation axis AX1. F2 and F3 occur. Regarding the first rotation axis AX1, the driving force F1 of the first coil CO1 and the driving force F2 of the second coil CO2 are forces having the same magnitude and the same rotation direction, and drive the third coil CO3. The force F3 and the driving force F4 of the fourth coil CO4 are forces having the same magnitude and the same rotation direction. As a result, the second rotating body 22 supporting the coils CO1 to CO4 receives a counterclockwise rotational force, that is, a driving force when directed to the + Y side along the first rotation axis AX1. The driving forces F1 to F4 have the same magnitude and are perpendicular to the paper surface and parallel to the Z axis in the circumferential direction of rotation about the first rotation axis AX1 so as to form a couple around the first rotation axis AX1. Is given in the direction).

In the case of FIG. 4D, the first terminal TA1 shown in FIG. 1 has a relatively negative potential, and the third terminal TA3 has a relatively positive potential. As a result, on the right side (+ X side) along the paper surface with respect to the first rotation axis AX1, the driving force F1 by the Lorentz force is downward (-Z side) perpendicular to the paper surface in the first and fourth coils CO1 and CO4. , F4 is generated, and the driving force by Lorentz force is upward (+ Z side) perpendicular to the paper surface in the second and third coils CO2 and CO3 on the left side (-X side) along the paper surface with respect to the first rotation axis AX1. F2 and F3 occur. Regarding the first rotation axis AX1, the driving force F1 of the first coil CO1 and the driving force F2 of the second coil CO2 are forces having the same magnitude and the same rotation direction, and drive the third coil CO3. The force F3 and the driving force F4 of the fourth coil CO4 are forces having the same magnitude and the same rotation direction. As a result, the second rotating body 22 supporting the coils CO1 to CO4 receives a clockwise rotational force, that is, a driving force when directed to the + Y side along the first rotating shaft AX1. The driving forces F1 to F4 have the same magnitude and are applied in the circumferential direction so as to form a couple around the first rotation axis AX1.

If the states shown in FIGS. 4 (C) and 4 (D) are alternately repeated, a driving force for reciprocating the second rotating body 22 around the first rotating shaft AX1 can be applied. However, the second rotating body 22 has a structure that allows a slight torsional rotation around the first rotating shaft AX1 but cannot rotate significantly. Therefore, although the second rotating body 22 itself does not substantially rotate, the first rotating body 23 supported by the second rotating body 22 can be indirectly reciprocated around the first rotating shaft AX1. In this case, the first rotating body 23 reciprocates or reciprocates (that is, swings) in the resonance cycle.

FIG. 5A is a block diagram illustrating a specific example of the circuit configuration of the drive unit 80 shown in FIG. The drive unit 80 includes a relatively low-frequency waveform forming device 81, a relatively high-frequency waveform forming device 82, a first amplifier 84, and a second amplifier 85. The low-frequency waveform forming device 81 outputs the low-speed side drive signal S1 for rotating the second rotating body 22 as the first driving signal from the pair of output terminals. The low-speed side drive signal S1 operates the second rotating body 22 in a non-resonant manner, and any frequency can be used. The low-speed side drive signal S1 that enables the non-resonant operation of the second rotating body 22 is not limited to the sawtooth wave used for raster scanning or the like, but may be a triangular wave or a sine wave, but is an aperiodic pulse. It may be a wave or a square wave. Further, the low-speed side drive signal S1 can have a DC component added as a bias. That is, as the low-speed side drive signal S1, various signals that enable non-resonant and periodic operation and non-periodic operation can be used. Needless to say, the low-speed side drive signal S1 may have a frequency corresponding to the resonance frequency of the second rotating body 22, and the second rotating body 22 may be operated in a resonant manner. One low-speed side drive signal S1 from the waveform forming device 81 is output to the terminals TA1 and TA2 in positive phase, that is, to the first coil system CS1 via the first amplifier 84, and is output to the other low-speed side from the waveform forming device 81. The drive signal S1 passes through the second amplifier 85 and is output in the positive phase between the terminals TA3 and TA4, that is, to the second coil system CS2. The high-frequency waveform forming device 82 outputs the high-speed side drive signal S2 for rotating the first rotating body 23 as the second drive signal from the pair of output terminals. The high-speed side drive signal S2 causes the first rotating body 23 to operate in a resonant manner. The high-speed side drive signal S2 can be a sinusoidal one, and can be a frequency corresponding to the resonance frequency of the first rotating body 23. One high-speed side drive signal S2 from the waveform forming device 82 is output in positive phase between terminals TA1 and TA2, that is, to the first coil system CS1 via the first amplifier 84, and is output to the other high-speed side from the waveform forming device 82. The drive signal S2 passes through the second amplifier 85 and is output to the terminals TA3 and TA4, that is, the second coil system CS2 in a state where the phase is inverted, that is, in opposite phase.

As shown in FIG. 5B, the low-speed side drive signal (first drive signal) S1 is supplied to both coil systems CS1 and CS2 in the positive phase (that is, in a state where the symbols match). This low-speed side drive signal (first drive signal) S1 is a basic drive signal, and as will be described in detail later, a rotational force can be generated around the second rotation shaft AX2 via the coil systems CS1 and CS2. It can be used, for example, for sub-scanning of light rays by the scanner 10. As shown in FIG. 5C, the high-speed side drive signal (second drive signal) S2 is supplied to the first coil system CS1 in the positive phase and to the second coil system CS2 in the opposite phase, and as a result, mutually. It is supplied with the code inverted. This high-speed side drive signal (second drive signal) S2 is an additional drive signal, and as will be described in detail later, a rotational force can be generated around the first rotation axis AX1 via the coil systems CS1 and CS2. It can be used, for example, for the main scanning of light rays by the scanner 10. In this case, the drive shown in FIGS. 4 (A) and 4 (B) is driven by the low-speed side drive signal S1 output in the positive phase to both coil systems CS1 and CS2 (as a result, in the positive phase to each coil CO1 to CO4). The operation of alternately applying the force is repeated, and in parallel with this, the first coil system CS1 is in the positive phase and the second coil system CS2 is in the opposite phase (as a result, the first and second coil CO1, The driving force shown in FIGS. 4 (C) and 4 (D) is alternately applied by the high-speed side drive signal S2 output to CO2 in the positive phase and to the third and fourth coils CO3 and CO4 in the opposite phase). The operation to be performed can be repeated. The amplifiers 84 and 85 shown in FIG. 5A are not limited to operational amplifiers, and may be composed of various circuit elements.

6 (A) and 6 (B) are conceptual enlarged cross-sectional views for explaining the states of the magnetic field, the current, and the driving force of the first coil CO1, and FIGS. 3 (A) and 3 (B) or FIG. Corresponds to the states shown in 4 (A) and 4 (B). A first coil CO1 extending parallel to the XY plane is formed on one of the peripheral annular portions 22d of the second rotating body 22, and the magnetic poles 51 and 52 constituting the first magnetic field former MG1 are the first coil CO1. Is arranged so as to sandwich from the lateral direction corresponding to the X direction or the Y direction. The first magnetic field former MG1 forms a magnetic field H1 that is parallel to the coil surface CS of the first coil CO1, that is, the XY surface, crosses the first coil CO1, and goes inward. As a result, positive and negative Lorentz forces are generated in the Z direction according to the directions of the currents I11 and I21 supplied to the first coil CO1, and the driving force F1 for rotating the first coil CO1 is obtained. Here, the direction of the driving force F1 is perpendicular to the direction of the magnetic field H1 and the directions of the currents I11 and I21. That is, the direction of the driving force F1 is parallel to the tangential direction of the rotation locus TR of the first coil CO1 or the second rotating body 22 around the second rotating shaft AX2 (see FIG. 1) outside the drawing. , The driving force F1 can give a lean rotational force to the second rotating body 22. The above operation directly describes the case where the currents I11 and I21 have low frequencies from the viewpoint of assuming FIGS. 3 (A) and 3 (B), but the currents I11, The same applies even if I21 has a high frequency.

FIG. 6C is a conceptual enlarged cross-sectional view illustrating the states of the magnetic field, current, and driving force of the coil of the device of the comparative example. The first coil CO1 is formed on the peripheral annular portion 22d'of one of the second rotating bodies 22', and the 51'and 52' constituting the first magnetic field former MG1' Z the first coil CO1. It is arranged so as to be sandwiched from the vertical direction corresponding to the direction. In the case of the device of the comparative example shown in FIG. 6C, the first is due to the interaction between the magnetic field formed by the first coil CO1 according to Ampere's law and the magnetic field HV formed by the first magnetic field former MG1'. A force can be generated with respect to the coil CO1 in the direction perpendicular to the coil surface CS, but it is not easy to obtain a large driving force by this. Since the magnetic flux in the direction perpendicular to the coil surface CS is canceled between the adjacent electric wires constituting the first coil CO1 (that is, between the currents flowing in parallel), only the magnetic flux inside and outside the first coil CO1 remains as effective, and the coil. Since the driving force in the direction perpendicular to the surface CS remains inside and outside the first coil CO1 but is totally canceled out, the driving force applied to the second rotating body 22'supporting the first coil CO1 is applied. Power is insufficient. Further, in the case of the device of the comparative example, the driving force according to Fleming's left-hand rule does not go in the direction perpendicular to the coil surface CS. Specifically explaining this point, the first magnetic field former MG1'forms a magnetic field HV perpendicular to the coil surface CS, that is, the XY surface of the first coil CO1. The direction of the Lorentz force FV generated according to the direction of the current supplied to the first coil CO1 according to Fleming's left-hand rule is along the coil surface CS, that is, the XY surface, and is directed in the direction perpendicular to the coil surface CS. Therefore, the driving force applied to the second rotating body 22'is insufficient. Further, when the magnetic field HV is formed in the entire first coil CO1, the Lorentz force FV is balanced as a whole and the resultant force becomes substantially zero. As a result, the Lorentz force FV applied to the second rotating body 22'may cause the second rotating body 22' to vibrate, but the driving efficiency becomes extremely low. Further, even if the second rotating body 22'or the first coil CO1 can be displaced along the allowable locus TR, the first magnetic field former MG1'is hindered by the magnetic poles 51'and 52'. 2 The movable range of the rotating body 22'is narrowed.

Hereinafter, the specific operation of the drive device 100 will be described with reference to FIGS. 1, 3 (A), 3 (B), 4 (A) to 4 (D), FIGS. 5 (A) to 5 (C), and the like. To do.

First, a non-resonant rotational operation around the second rotation axis AX2 will be described with reference to FIGS. 1, 5 (A), 4 (A), and the like. In this case, the current supplied from the drive unit 80, that is, the first drive signal S1, has a low frequency (1 kHz or less, for example 30, 50, 60 Hz suitable for raster scanning), and is, for example, a sawtooth type. From the drive unit 80, the first coil system CS1 including the first and second coils CO1 and CO2 and the second coil system CS2 including the third and fourth coils CO3 and CO4 are connected via terminals TA1 to TA4. The currents I1 to I4 corresponding to the positive-phase signals having the same polarities are supplied (corresponding to the operation of the first amplifier 84 in FIG. 5A). That is, two signals are output from the relatively low frequency waveform forming device 81 constituting the drive unit 80, one signal is applied to the first coil system CS1 in the positive phase by the amplifier 84, and the other signal is applied. The signal is also applied to the second coil system CS2 in the positive phase through the amplifier 85. As a result, when the counterclockwise current is a forward current, the positive and counterclockwise forward currents I1 and I3 flow through the first and third coils CO1 and CO3, and the second and fourth coils A positive and clockwise reverse currents I2 and I4 flow through the coils CO2 and CO4. Due to the electromagnetic action of this current and the fixed magnetic field (that is, Fleming's left-hand rule), + Z-direction, that is, upward force is generated in the first and third coils CO1 and CO3, and the second and fourth coils are generated. A force in the −Z direction, that is, downward is generated in the coils CO2 and CO4 (specifically, see FIG. 4 (A)). When the directions of the currents I1 to I4 are reversed in both coil systems CS1 and CS2, a force in the −Z direction, that is, downward is generated in the first and third coils CO1 and CO3, and the second and fourth coils CO2 and CO4 are affected. Generates a force in the + Z direction, that is, upward (specifically, see FIG. 4 (B)). The second rotating body 22 periodically repeats forward and reverse rotations around the second rotating shaft AX2. As a result, the first rotating body 23 supported by the second rotating body 22 or the mirror 24 formed on the surface thereof is integrated with the second rotating body 22 around the second rotating shaft AX2 to rotate in the forward and reverse directions. Repeat periodically. At this time, it is avoided that the rotational force is applied around the diagonal axis inclined with respect to the second rotation axis AX2, and the force applied to the coils CO1 to CO4 by the first drive signal S1 is applied to the second rotation axis AX2. It can be used without waste as a rotational force around it. Further, when the first drive signal S1 includes a DC component as a bias signal, an offset (shifting the center angle) can be added to the center angle of rotation or the reference angle.

Next, the rotational operation of the resonance around the first rotation axis AX1 will be described with reference to FIGS. 1, 5 (A), 4 (C), and the like. In this case, the current supplied from the drive unit 80, that is, the second drive signal S2 is a high frequency (for example, 1 kHz to 20 kHz) and is a sine wave type. The drive unit 80 supplies the currents I1 and I2 corresponding to the positive phase signals to the first coil system CS1 including the first and second coils CO1 and CO2 via the terminals TA1 and TA2, and at the same time. Currents I3'and I4' corresponding to opposite phase signals are supplied to the second coil system CS2 including the third and fourth coils CO3 and CO4 via terminals TA3 and TA4 (No. 5 in FIG. 5). 2 Corresponds to the operation of the amplifier 85). That is, two signals are output from the relatively high frequency waveform forming device 82 constituting the drive unit 80, one signal is applied to the first coil system CS1 in the positive phase by the amplifier 84, and the other signal is applied. Is inverted in phase through the amplifier 85 to become a reverse phase signal, and is applied to the second coil system CS2. As a result, when the counterclockwise current is a forward current, a positive-phase counterclockwise forward current I1 flows through the first coil CO1, and a positive-phase clockwise current flows through the second coil CO2. A clockwise reverse current I2 flows, and a counterclockwise forward current I4'flows in the fourth coil CO4 in a reverse phase, and a counterclockwise reverse current I4'flows in the third coil CO3. I3'flows. Due to the electromagnetic action of this current and the fixed magnetic field (that is, Fleming's left-hand rule), the first and fourth coils CO1 and CO4 given the counterclockwise forward currents I1 and I4'are + Z. An upward force is generated, and a clockwise reverse current I2, I3'is applied to the second and third coils CO2 and CO3, and a −Z direction, that is, a downward force is generated (specifically, FIG. 4 (C)). When the directions of the currents I1, I2, I3'and I4'are reversed in both coil systems CS1 and CS2, a force in the -Z direction, that is, downward is generated in the first and fourth coils CO1 and CO4, and the second and second coils are used. A + Z direction, that is, an upward force is generated in the three coils CO2 and CO3 (specifically, see FIG. 4 (D)). As described above, a common unidirectional force is generated on one of the first and fourth coils CO1 and CO4 sandwiching the first rotating shaft AX1, and the other second and second forces sandwiching the first rotating shaft AX1 are generated. When a force in the opposite direction common to the three coils CO2 and CO3 is generated, the second rotating body 22 does not rotate significantly due to the presence of the second torsion bars 32a and 32b, but around the first rotating shaft AX1. A slight periodic torsional rotation (that is, periodic fluctuation of the displacement angle) is given. This slight periodic torsional rotation is transmitted from the second rotating body 22 to the first rotating body 23 via the first torsion bars 31a and 31b, and the first rotating body 23 is moved around the first torsion bars 31a and 31b. Rotate. When such rotation satisfies the resonance condition, the first rotating body 23 or the mirror 24 reciprocates while resonating around the first rotating shaft AX1 or the first torsion bars 31a and 31b with a relatively large amplitude. As a result, the mirror 24 resonates around the first rotation axis AX1. As is clear from the above, in a state where a positive phase signal is applied to both the first coil system CS1 and the second coil system CS2 (see FIGS. 4A and 4B), the second rotating body 22 or the mirror While the 24 reciprocates around the second rotation axis AX2, a positive phase signal is applied to the first coil system CS1 and a negative phase signal is applied to the second coil system CS2 (FIG. 4 (C). ) And 4 (D)), the first rotating body 23 or the mirror 24 reciprocates around the first rotating shaft AX1. This means that by switching the signal, it is possible to switch between the rotational operation of the second rotating body 22 around the second rotating shaft AX2 and the rotating operation of the first rotating body 23 around the first rotating shaft AX1. That means that the axis of rotation can be switched. As shown in FIGS. 4 (C) and 4 (D), the second drive signal S2 is applied to the first coil system CS1 in the positive phase while being applied to the second coil system CS2 in the opposite phase. , It is avoided that the rotational force is applied around the diagonal axis inclined with respect to the first rotation axis AX1, and the force applied to each coil CO1 to CO4 by the second drive signal S2 is applied around the first rotation axis AX1. It can be used as a rotational force without waste. The high frequency supplied from the drive unit 80 corresponds to the resonance frequency of the first rotating body 23 in order to achieve efficient resonance around the first rotating shaft AX1. In the above description, it is assumed that the second drive signal S2 is a sine wave type, but the second drive signal S2 does not have to be a sine wave strictly, and is a pseudo sine wave, a square wave, a triangular wave, or another periodic signal. It may be.

Summarizing the above, the drive unit 80 shown in FIG. 5 (A) uses the low-frequency first drive signal S1 as a positive-phase signal with respect to the coils CO1 to CO4 shown in FIGS. 4 (A) and 4 (B). By supplying (specifically, for example, when a counterclockwise forward current I1 is supplied to the coil CO1, a clockwise reverse current I2 is supplied to the coil CO2 and a counterclockwise current I2 is supplied to the coil CO3. A forward current I3 is supplied, a clockwise reverse current I4 is supplied to the coil CO4), and a relatively low-period reciprocating rotation around the second rotation axis AX2 of the mirror 24 is possible. Further, in parallel with the supply of the first drive signal S1, specifically the low-frequency signal, the high-frequency second drive signal S2 is generated by the drive unit 80 shown in FIG. 5 (A) in FIGS. 4 (A) and 4 (A). It is supplied as a positive phase signal to the coils CO1 and CO2 shown in (B) and is supplied as a negative phase signal to the coils CO3 and CO4, that is, only the polarity of the drive signal with respect to the coils CO3 and CO4 is changed. (Specifically, for example, when the counterclockwise forward current I1 is supplied to the coil CO1, the clockwise reverse current I2 is supplied to the coil CO2, and the clockwise reverse direction is supplied to the coil CO3. The current I3'is supplied, the coil CO4 is supplied with the counterclockwise forward current I4'), and a relatively high cycle reciprocating rotation around the first rotation axis AX1 is possible. As a result, a two-axis reciprocating rotation operation in which a relatively low-period reciprocating rotation around the second rotation axis AX2 and a relatively high-period reciprocating rotation around the first rotation axis AX1 are combined while maintaining independence. Becomes possible.

According to the drive device 100 of the embodiment described above, a rotational force is generated around the second rotation axis AX2 by the first drive signal (low speed side drive signal) S1 applied to each coil CO1 to CO4 in the positive phase. The first drive signal (high-speed side drive signal) S2 is applied to the first and second coils CO1 and CO2 in the positive phase and applied to the third and fourth coils CO3 and CO4 in the opposite phase. A rotational force can be generated around the rotation axis AX1. That is, a combination of applying a positive phase signal to the first and second coils CO1 and CO2 and making the signal applied to the third and fourth coils CO3 and CO4 either positive or negative phase (that is, of the drive signal). By (partial change of polarity), the rotational force around the second rotation axis AX2 and the rotational force around the first rotation axis AX1 can be arbitrarily switched, or the rotational force around these two rotation axes AX1 and AX2 can be changed. It can be generated in parallel by independent control. At this time, the force applied to each coil CO1 to CO4 by the first drive signal S1 can be used without waste as the rotational force around the second rotation shaft AX2, and the force applied to each coil CO1 to CO4 by the second drive signal S2 can be used. The applied force can be used as the rotational force around the first rotation axis AX1 without waste, and as a result, it is avoided that the rotational force is applied around the diagonal axis inclined with respect to both rotation axes AX1 and AX2. Not only is it possible to achieve good drive efficiency, but it is also possible to realize a scanning locus with little distortion. Moreover, since the coils CO1 to CO4 are arranged on the same plane, the driving force applied to the coils CO1 to CO4 is the circumferential direction or tangent line of rotation centered on the first or second rotation axes AX1 and AX2. Since it is along the direction, all of the driving force contributes to the rotation without waste, and it is possible to surely suppress the generation of unnecessary vibration due to the translational force or the unnecessary force that does not contribute to the rotation. Further, by applying a magnetic field in a direction parallel to the coil surface CS by the magnetic field forming unit (magnetic field applying means) 12, a large force can be generated for each coil CO1 to CO4 in the direction perpendicular to the coil surface CS. , A large swing angle can be realized for the rotating bodies 22 and 23 that support the coils CO1 to CO4. Any frequency can be used for the first drive signal S1 for operating the drive device 100, and the first drive signal S1 is not limited to a periodic one but can be aperiodic. By such a first drive signal S1, the second rotating body 22 can be rotated non-resonantly at an arbitrary frequency, and further, not only periodically but also non-periodically, so that the second rotating body 22 is tilted. The degree of freedom regarding operation patterns such as timing is increased, and the applications of the drive device 100 can be expanded.

[Other]
The present invention is not limited to the above-described embodiment, and can be implemented in various embodiments without departing from the gist thereof.

For example, in the above embodiment, the first to fourth coils CO1 to CO4 are made into two turns, but the number of coil turns can be variously set according to the specifications of the drive device 100, and the first to first coils can be set in various ways. The current supplied to the four coils CO1 to CO4 can also be set in various ways according to the specifications of the drive device 100.

The direction of the magnetic flux or magnetic field generated by the first to fourth magnetic field formers MG1 to G4 is not limited to inward with respect to the first to fourth coils CO1 to CO4, but is based on the first to fourth coils CO1 to CO4. It can also be turned outward. However, even in that case, by setting the direction of the current flowing through the first to fourth coils CO1 to CO4, the driving force shown in FIGS. 4 (A) and 4 (B) and the driving forces shown in FIGS. ) Is adjusted so that the driving force shown in is generated.

The outer support 21 is not limited to having a rectangular frame-shaped outer shape, and may have a U-shape, a C-shape, or the like. The first rotating body 23 is not limited to having an oval outer shape, and may have various shapes such as a circle, an ellipse, a square, a rectangle, and a polygon. The second rotating body 22 is not limited to having a rectangular frame-shaped outer shape, and may have a U-shaped shape, a C-shaped shape, or an oval outer shape.

AX1, AX2 ... Rotating shaft, CO1-CO4 ... 1st to 4th coils, CS1 ... 1st coil system, CS2 ... 2nd coil system, R1-R4 ... Region, F1-F4 ... Driving force, F11-F14 ... Driving Force, F21-F24 ... Driving force, H1-H4 ... Magnetic field, I11-I14 ... Current, I21-I24 ... Current, MG1-MG4 ... Magnetic field former, OP1-OP4 ... Peripheral opening, S1 ... Low speed side drive signal (No. 1) 1 drive signal), S2 ... high-speed side drive signal (second drive signal), 10 ... scanner, 11 ... scanner body, 12 ... magnetic field forming unit (magnetic field applying means), 13 ... support substrate, 21 ... support, 22 ... 2nd rotating body, 22b ... Central annular portion, 22d ... Peripheral annular portion, 23 ... 1st rotating body, 24 ... Mirror, 31a, 31b ... 1st torsion bar, 32a, 32b ... 2nd torsion bar, 51 ... 1st Magnetic pole, 53, 54 ... Magnet, 52 ... Second magnetic pole, 55 ... Yoke, 80 ... Drive circuit, 81, 82 ... Waveform forming device, 84, 85 ... Amplifier, 100 ... Drive device

Claims (8)

With the first rotating body
A second rotating body arranged outside the first rotating body and rotatably supporting the first rotating body around the first rotating shaft.
A support that rotatably supports the second rotating body around the second rotating shaft,
On the second rotating body, the intersections of the first and second rotating shafts are arranged in each region on the same plane divided into four by the first and second rotating shafts, and the intersections are sandwiched and opposed to each other. A circuit including the first and second coils and the third and fourth coils facing each other across the intersection.
Each coil is provided with a magnetic field applying means that applies a magnetic field in a direction parallel to the coil surface.
The first drive signal is applied to each of the coils in the positive phase.
A drive device in which a second drive signal is applied to the first and second coils in a positive phase and to the third and fourth coils in a reverse phase. The drive device according to claim 1, further comprising a drive unit that outputs the first drive signal and the second drive signal. The magnetic field applying means applies a magnetic field toward one of the inside and outside in common with the first to fourth coils.
The first and second coils are connected so that a clockwise current flows through the second coil when a counterclockwise current flows through the first coil, and the third and fourth coils are connected so that a clockwise current flows through the first coil. The drive device according to any one of claims 1 and 2, which is connected so that a clockwise current flows through the fourth coil when a counterclockwise current flows through the three coils. The first and second coils are connected by a first wiring formed on a central annular portion of the second rotating body arranged around the first rotating body, and the third and fourth coils are connected. The drive device according to claim 3, which is connected by a second wiring formed on the central annular portion. The driving device according to any one of claims 1 to 4, wherein the second rotating body has four peripheral annular portions formed on the surface of the first to fourth coils. The support rotatably supports the second rotating body around the second rotating shaft via a second torsion bar.
The drive according to any one of claims 1 to 5, wherein the second rotating body supports the first rotating body in a twistable manner around the first rotating shaft via a first torsion bar. apparatus. The first rotating body rotates around the first rotating shaft in a resonance period.
The driving device according to any one of claims 1 to 6, wherein the second rotating body reciprocates around the second rotating shaft following a force applied to the first to fourth coils. A second rotating body that is arranged outside the first rotating body and rotatably supports the first rotating body around the first rotating shaft, and the second rotating body that can rotate around the second rotating shaft. The supporting body and the second rotating body are arranged in each region on the same plane divided into four by the first and second rotating axes around the intersection of the first and second rotating axes. A drive device including a circuit including a first and second coils facing each other across the intersection and a third and fourth coils facing each other across the intersection.
Applying a magnetic field in the direction parallel to the coil surface to each coil,
The first drive signal is applied to each of the coils in the positive phase.
A driving method in which the second drive signal is applied to the first and second coils in the positive phase and to the third and fourth coils in the opposite phase.

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