Reflector Scanner

Abstract

To provide a reflector scanner capable of suppressing manufacturing cost and crosstalk.SOLUTION: A reflector scanner includes; a frame that has a frame-shaped portion and a pair of bridging portions and being rotatably held about a first axis; a mirror portion that is connected to the inside of the frame via a first elastic member that extends in a second axis direction; and first and second driving units. The first driving unit includes: a magnet pair with magnets facing each other across the frame on the first axis; a first coil wired in a first annular portion including one bridging portion close to one magnet of the magnet pair and a portion of the frame-shaped portion on a one magnet side; and a second coil wired in a second annular portion including the other bridging portion close to the other magnet of the magnet pair and a portion of the frame-shaped portion on the other magnet side. The second driving unit includes: a second magnet pair with magnets facing each other across a region between the pair of bridging portions of the frame on the second axis; and a third coil at least wired in a region between the pair of bridging portions of the frame-shaped portion.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a reflector scanner that scans the orientation of a reflector.

Background Art

[0002] As such a reflector scanner, a driving device having a MEMS (Micro Electro Mechanical Systems) structure that reflects received light while scanning it in two axial directions orthogonal to each other is known.

[0003] Further, as the driving device, a plate-like and rectangular first movable part provided with three openings juxtaposed along a first direction, a second movable part provided with a reflecting surface, and a support are proposed (see Patent Document 1).

[0004] The second movable part is supported within the central opening of the first movable part by a pair of first torsion bars extending in the first direction. The support supports the first movable part by a pair of second torsion bars extending in a second direction orthogonal to the first direction.

[0005] On the surface of the first movable part, a first coil wired so as to surround the central opening and a second coil wired so as to surround the three openings along the ends of the four sides of the first movable part are arranged. Further, at both end openings among the three openings of the first movable part, each of a pair of magnetic members magnetized to different polarities by a pair of first magnets is provided. The pair of magnets is disposed below the central opening of the first movable part. Further, around the support, a pair of second magnets with opposite polar faces are arranged in the vicinity of a pair of sections along the second direction in the second coil.

[0006] With this configuration, by intermittently passing current through the first coil, a force is applied to the region on the first movable part where the first coil is located and along the magnetic member (referred to as the first region), causing the second movable part to oscillate around the first torsion bar as its central axis. Similarly, by intermittently passing current through the second coil, a force is applied to the region on the first movable part where the second coil is located and along the second magnet (referred to as the second region), causing the second movable part to oscillate around the second torsion bar as its central axis. As a result, the orientation of the reflective surface of the second movable part is scanned in the first and second directions, making it possible to scan the received light in two axial directions. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6726356 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] By the way, in the drive device described in Patent Document 1, the second magnets at the ends of the four sides of the first movable part are wired not only with the second coil but also with the first coil in the region along the adjacent sides. Therefore, in this drive device, in order to prevent the force acting on this region due to the current flowing through the first coil, so-called crosstalk, the second magnets are arranged in four locations in that region, excluding the section where the first coil is wired.

[0009] Therefore, in constructing such a drive device, it was necessary to prepare four second magnets in addition to the first pair of magnets, that is, six sets of magnets, and to install them in a distributed manner. This led to an increase in the number of parts and structural complexity, resulting in higher manufacturing costs.

[0010] Therefore, the present invention aims to provide a reflector scanner that can reduce manufacturing costs and crosstalk. [Means for solving the problem]

[0011] The reflector scanner according to the present invention includes a frame having a frame-shaped portion extending along a plane and held so as to be rotatable about a first axis along the plane; a mirror portion connected to the inside of the frame via a first elastic member extending along a second axis along the plane; a first drive unit for rotating the frame in a direction of rotation with the second axis as the central axis; and a second drive unit for rotating the frame in a direction of rotation with the first axis as the central axis, wherein the frame extends inside the frame so as to sandwich the first axis and has a pair of bridging portions spanning across opposing portions of the frame sandwiching the second axis; and the first drive unit has a first magnetic The second drive unit includes a pair of magnets, a first coil wired to a first annular portion formed by a pair of magnets, a bridging portion closer to one of the magnets of the first magnet pair than the mirror portion, and a portion of the frame-shaped portion on one side of the first magnet pair than the first bridging portion, and a second coil wired to a second annular portion formed by another bridging portion closer to the other magnet of the first magnet pair than the mirror portion, and a portion of the frame-shaped portion on the other side of the first magnet pair than the other bridging portion, wherein the second drive unit includes a second pair of magnets arranged opposite to each other on the second axis so as to straddle the region between the pair of bridging portions of the frame, and a third coil wired in at least the region between the pair of bridging portions of the frame-shaped portion.

[0012] Furthermore, the reflector scanner according to the present invention has a frame-shaped portion extending along a plane 1 and is held so as to be rotatable about a first axis along the plane 1, a mirror portion connected to the inside of the frame via a first elastic member extending along a second axis along the plane 1, a pair of magnets arranged opposite each other so as to sandwich the frame, a coil wired to the frame-shaped portion of the frame and the pair of bridging portions, a first support column installed inside the frame by the first annular portion, and the second annular portion The frame includes a second support column installed inside the frame, wherein the frame extends inside the frame so as to sandwich the first axis, and has a pair of bridging sections that span across opposing portions of the frame on either side of the second axis, the first support column is connected to one of the pair of bridging sections via an elastic member that extends along the first axis, and the second support column is connected to the other of the pair of bridging sections via an elastic member that extends along the first axis. [Effects of the Invention]

[0013] According to the present invention, by using four magnets, the influence (crosstalk) that the drive current supplied to the coil to rotate the frame, to which the mirror portion is connected via an elastic member, in the direction of rotation around the second axis has on the force that rotates the frame in the direction of rotation around the first axis is suppressed, and the mirror portion can be oscillated in two axial directions.

[0014] Therefore, according to the present invention, it is possible to reduce the scale of the equipment and the manufacturing cost. [Brief explanation of the drawing]

[0015] [Figure 1A] This is a top view of a reflector scanner 200 according to a first embodiment of the present invention. [Figure 1B] This is a side view of the reflective scanner 200. [Figure 2]It is a top view of the reflector scanner 200 showing the direction of the current flowing through each coil of the reflector scanner 200, the direction of the magnetic field, and the direction of the Lorentz force. [Figure 3A] It is a top view of the reflector scanner 300 according to the second embodiment of the present invention. [Figure 3B] It is a side view of the reflector scanner 300. [Figure 4] It is a top view of the reflector scanner 300 showing the direction of the current flowing through each coil of the reflector scanner 300, the direction of the magnetic field, and the direction of the Lorentz force. [Figure 5] It is a top view of the reflector scanner 400 according to the third embodiment of the present invention. [Figure 6A] It is a top view of the reflector scanner 500 according to the fourth embodiment of the present invention. [Figure 6B] It is a side view of the reflector scanner 500. [Figure 7] It is a top view of the reflector scanner 600 according to the fifth embodiment of the present invention. [Figure 8] It is a top view of the reflector scanner 700 as a modified example of the reflector scanner 600 according to the present invention.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Examples

[0017] FIG. 1A is a top view of the reflector scanner 200 according to the first embodiment of the present invention as viewed from above, and FIG. 1B is a side view of the reflector scanner 200 as viewed from the direction of the white arrow shown in FIG. 1A.

[0018] The reflector scanner 200 is, for example, a MEMS (Micro Electro Mechanical System) mirror in which a mirror part MR having a reflecting surface is configured to swing in two axial directions with the first axis J1 and the second axis J2 orthogonal to the first axis J1 as the center axes of rotation, respectively.

[0019] As shown in Figures 1A and 1B, the reflector scanner 200 includes a frame 20, support columns 21a and 21b, a pair of magnets 31a and 31b as first magnets, a pair of magnets 32a and 32b as second magnets, and a base 40.

[0020] The frame 20 is divided by openings Oa, Os, and Ob, which are arranged side by side along the direction of the first axis J1, into a frame-shaped portion FR that extends along the outer edge of one face of the frame 20, and a pair of bridging portions consisting of a bridging portion Ba between opening Oa and opening Os, and a bridging portion Bb between opening Ob and opening Os. In other words, the frame 20 is composed of a frame-shaped portion FR that extends along the outer edge, and a pair of bridging portions (Ba, Bb) that connect the frame-shaped portions FR, which extend so as to sandwich the first axis J1, at the portions that face each other across the second axis J2.

[0021] Furthermore, in frame 20, the annular region consisting of the bridging portion Ba, which is closer to the magnet 31a, and the frame-shaped portion FR surrounding the opening Oa, is referred to as the annular region Ra. In addition, in frame 20, the annular region consisting of the bridging portion Rb, which is closer to the magnet 31b, and the frame-shaped portion FR surrounding the opening Ob, is referred to as the annular region Rb.

[0022] Within the opening Os, that is, in the region between the bridging sections Ba and Bb, a mirror section MR is installed, which is connected to the frame-shaped section FR of the frame 20 via torsion bars T1a and T1b that extend along the second axis J2.

[0023] Inside the opening Oa, that is, inside the annular region Ra, a support column 21a is installed, which is connected to the frame-shaped portion FR of the frame 20 via a torsion bar T2a that extends along the first axis J1.

[0024] Inside the opening Ob, that is, inside the annular region Rb, a support column 21b is installed, which is connected to the frame-shaped portion FR of the frame 20 via a torsion bar T2b, which is an elastic member extending along the first axis J1. The torsion bars T1a, T1b, T2a, and T2b are each made of elastic members.

[0025] A coil L1, which is wired in a loop or spiral shape, is arranged in the annular portion of the annular region Ra. One end and the other end of the wiring forming the coil L1 are connected to the power supply circuit 50 via a pair of wires that are wired inside the surface of the torsion bar T2a, the support column 21a, and the base 40, respectively.

[0026] A coil L2, which is wired in a loop or spiral shape, is arranged in the annular portion of the annular region Rb. One end and the other end of the wiring forming the coil L2 are connected to the power supply circuit 50 via a pair of wires that are wired inside the surface of the torsion bar T2b, the support column 21b, and the base 40, respectively.

[0027] Furthermore, in the region between the pair of bridging sections (Ba, Bb) (hereinafter also referred to as the central region), a coil L3 (shown by dashed lines) wired to the frame-shaped section FR and the pair of bridging sections (Ba, Bb) is arranged in a loop-like or spiral shape, surrounding the mirror section MR. One end of the wiring forming the coil L3 is connected to the power supply circuit 50 via wiring installed on the surface of the frame-shaped section FR, the torsion bar T2a, the support column 21a, and inside the base 40. The other end of the wiring forming the coil L3 is also connected to the power supply circuit 50 via wiring installed on the surface of the frame-shaped section FR, the torsion bar T2b, the support column 21b, and inside the base 40. The support columns 21a and 21b are installed on the base 40. Furthermore, regarding the wiring in the support columns 21a and 21b, it is possible to use TSV (Through-Silicon Via) as the support columns and wire the wiring inside them, or a bonding pad may be provided on the surface of the support columns and the wiring may be led to the outside by wire bonding over the frame 20 and the magnets (31a, 31b).

[0028] Specifically, as shown in Figure 1A, in frame 20, coil L1 is installed in the annular region Ra, and coil L2 is installed in the annular region Rb. Furthermore, in the central region between the annular region Ra and the annular region Rb, that is, the region between the pair of bridging sections described above, a mirror section MR and a third coil L3 are installed. Note that coil L3 includes a wiring section that is routed close to magnet 32a or 32b so as to cross the region sandwiched between at least one pair of magnets 32a and 32b.

[0029] The power supply circuit 50 supplies a first drive current, which is an alternating current, to coils L1 and L2, respectively, to cause the mirror section MR to oscillate in the direction of rotation around the second axis J2. Furthermore, the power supply circuit 50 supplies a second drive current, which is an alternating current, to coil L3 to cause the mirror section MR to oscillate in the direction of rotation around the first axis J1. In Figure 1B, the power supply circuit 50 is installed at a distance from the base 40, but it may also be installed directly on the base 40.

[0030] Magnets 31a, 31b, 32a, and 32b are mounted on the base 40 so that one magnet is positioned on each of the outer perimeters adjacent to each side of the frame 20. The height of each magnet 31a, 31b, 32a, and 32b from the surface of the base 40 is greater than or equal to the height from the base 40 to the surface of the frame 20.

[0031] Furthermore, the magnets 31a and 31b, which constitute the first magnet pair, are installed on the base 40 so as to sandwich the frame 20 on the first axis J1 with faces that have opposite polarities facing each other.

[0032] Furthermore, the magnets 32a and 32b, which constitute the second magnet pair, are installed on the base 40 so as to sandwich the frame 20 on the second axis J2 with faces that have opposite polarities facing each other.

[0033] Furthermore, the length of each of the magnets 32a and 32b in the direction along the first axis J1 shall be such that it can at least enclose the central region, that is, the region between a pair of bridging parts (Ba, Bb).

[0034] The operation of the reflector scanner 200 will be explained below with reference to Figure 2.

[0035] Figure 2 is a top view of the reflector scanner 200, showing the direction of the current flowing through each coil of the reflector scanner 200, the direction of the magnetic field, and the direction of the Lorentz force at a given point in time, indicated by symbols or arrows.

[0036] The power supply circuit 50 supplies a drive current i1, which is an alternating current, to coil L1, and also supplies a drive current i1e, which is an alternating current with the phase inverted of the drive current i1, to coil L2. As a result, at a given point in time, the drive current i1 flows clockwise through coil L1, for example as shown by the arrow in Figure 2, and the drive current i1e flows clockwise through coil L2, for example as shown by the arrow in Figure 2.

[0037] Therefore, a first Lorentz force is applied to the left end of the frame 20 in accordance with the magnetic field B1 (indicated by the white arrow) from magnet 31a and the driving current i1 (indicated by the black arrow) crossing the magnetic field B1. Furthermore, a second Lorentz force is applied to the right end of the frame 20 in accordance with the magnetic field B1e (indicated by the white arrow) from magnet 31b and the driving current i1e (indicated by the black arrow) crossing the magnetic field B1e. In this case, the direction in which the first Lorentz force is applied and the direction in which the second Lorentz force is applied are opposite to each other; that is, if one of the first and second Lorentz forces is applied in the direction facing the surface of the frame 20, the other is applied in the direction facing the back surface of the frame 20. As a result, a force (couple) is applied to the frame 20 that rotates the frame 20 about the second axis J2 as the central axis. Furthermore, since the drive currents i1 and i1e are alternating currents, the directions of the Lorentz forces acting on the right and left ends of the frame 20, respectively, remain in opposite directions while reversing with a period corresponding to the frequency of the alternating currents.

[0038] As a result, the frame 20 reverses the direction of rotation around the second axis J2 with a period corresponding to the frequency of the alternating current, and the torsion bars T1a and T1b, which are affected by this inertial force, twist, causing the mirror section MR to oscillate in the direction of rotation around the second axis J2.

[0039] Incidentally, the direction of the drive current flowing through the bridging portion Ba (Bb) of coil L1 (L2) is opposite to the direction of the drive current flowing through the frame-shaped portion FR on the left (right) end of frame 20. Therefore, the Lorentz force acting on the bridging portion Ba (Bb) due to the magnetic field B1 (B1e) shown in Figure 2 is in the opposite direction to the Lorentz force acting on the left (right) end of frame 20, that is, in the direction that hinders the rotational movement of frame 20. However, the distance from the bridging portion Ba (Bb) to the magnet 31a (31b) is longer than the distance from the frame-shaped portion FR on the left (right) end of frame 20 to the magnet 31a (31b). Therefore, the magnetic field b1 (b1e) at the bridging portion Ba (Bb) generated by the magnet 31a (31b) is smaller than the magnetic field B1 (B1e), so the generated torque is also smaller, and the effect of hindering the rotational movement of frame 20 is small.

[0040] Furthermore, in the reflector scanner 200, the power supply circuit 50 supplies a drive current i2, which is an alternating current, to the coil L3. As a result, at a given time, the drive current i2 flows through the coil L3 in the direction indicated by the arrow in Figure 2 within the frame-shaped portion FR.

[0041] Therefore, a third Lorentz force is applied to the frame-shaped part FR at the upper end of the frame 20 in accordance with the magnetic field B2 (indicated by the white arrow) from the magnet 32a and the driving current i2 (indicated by the black arrow) that crosses the magnetic field B1. Furthermore, a fourth Lorentz force is applied to the frame-shaped part FR at the lower end of the frame 20 in accordance with the magnetic field B2e (indicated by the white arrow) from the magnet 32b and the driving current i2 (indicated by the black arrow) that crosses the magnetic field B2e. In this case, the direction in which the third Lorentz force is applied and the direction in which the fourth Lorentz force is applied are opposite to each other; that is, if one of the third and fourth Lorentz forces is applied in the direction facing the surface of the frame 20, the other is applied in the direction facing the back surface of the frame 20. As a result, a force (couple) is applied to the frame 20 that rotates the frame 20 about the first axis J1 as the central axis. Furthermore, since the drive current i2 is an alternating current, the directions of the Lorentz forces acting on the upper and lower ends of the frame 20, respectively, remain in opposite directions while reversing with a period corresponding to the frequency of the alternating current.

[0042] As a result, the frame 20 reverses the direction of rotation around the first axis J1 with a period corresponding to the frequency of the alternating current, and the torsion bars T2a and T2b, which are affected by this inertial force, twist, causing the mirror section MR to oscillate in the direction of rotation around the first axis J1.

[0043] Incidentally, due to the magnetic field b1(b1e) acting on the bridging section Ba(Bb) and the driving current i2 flowing through the coil L3 across the magnetic field b1(b1e), a couple that rotates the frame 20 around the second axis J2 acts on the bridging section Ba(Bb) as crosstalk. However, as mentioned above, the distance from the bridging section Ba(Bb) to the magnet 31a(31b) is longer than the distance from the left (right) end of the frame 20 to the magnet 31a(31b). Furthermore, since the distance from the bridging section Ba(Bb) to the second axis J2 is short, the torque generated on the bridging section Ba(Bb) is small, and the effect of crosstalk is also small.

[0044] In the embodiment shown in Figure 1A, the frame 20 is provided with one pair of bridging sections (Ba, Bb), but the number of bridging sections provided on the frame 20 is not limited to two. In other words, as long as the frame 20 has one pair of bridging sections (Ba, Bb) surrounding the mirror section MR, the number of bridging sections can be three or more.

[0045] In short, the reflector scanner 200 swings the mirror section in two axial directions by employing a configuration that includes the following frame, mirror section, and first and second drive units.

[0046] In other words, the frame (20) has a frame-shaped portion (FR) that extends along a plane 1 and is held so as to be rotatable about a first axis (J1) along that plane 1. The frame extends inward so as to sandwich the first axis and has a pair of bridging portions (Ba, Bb) that span across opposing portions that sandwich a second axis (J2) along the plane 1. The mirror portion (MR) is connected to the inside of the frame via a first elastic member (T1a, T1b) that extends along the second axis along the plane 1. The first drive unit (31a, 31b, L1, L2) rotates the frame in the direction of rotation with the second axis as the central axis, and the second drive unit (32a, 32b, L3) rotates the frame in the direction of rotation with the first axis as the central axis. Here, the first drive unit includes a first pair of magnets (31a, 31b) arranged opposite to each other on a first shaft so as to sandwich the frame, and first and second coils wired to the frame. The first coil (L1) is wired to a first annular portion (Ra) formed by a bridging portion (Ba) that is closer to one of the magnets (31a) of the first pair of magnets (31a, 31b) than the mirror portion, and a portion of the frame-shaped portion (FR) that is closer to the first pair of magnets than the bridging portion. The second coil (L2) is wired to a second annular portion (Rb) formed by another bridging portion (Bb) that is closer to the other magnet (31b) of the first pair of magnets (31a, 31b) than the mirror portion, and a portion of the frame-shaped portion (FR) that is closer to the other bridging portion.

[0047] With this configuration, by using four magnets, it becomes possible to oscillate the mirror section in two axial directions by suppressing crosstalk, which occurs when the drive currents (i1, i1e) flowing through the first and second coils to rotate the frame in the direction of rotation around the second axis affect the force that rotates the frame in the direction of rotation around the first axis.

[0048] Therefore, according to the present invention, it is possible to reduce the size of the device and the manufacturing cost compared to the drive device described in Patent Document 1, which requires six magnets. [Examples]

[0049] Figure 3A is a top view of the reflector scanner 300 according to a second embodiment of the present invention, viewed from above, and Figure 3B is a side view of the reflector scanner 300 viewed from the direction of the white arrow shown in Figure 3A.

[0050] Furthermore, in the reflector scanner 300, the magnet 31b is installed on the base 40 such that the polarity of the surface of the magnet 31b facing the magnet 31a (for example, the south pole) is opposite to the polarity of the magnet 31b of the reflector scanner 200 (for example, the north pole). In other words, in the reflector scanner 300, the magnets 31a and 31b, as the first magnet pair, are installed on the base 40 such that their opposing surfaces have the same polarity.

[0051] Furthermore, the reflector scanner 300 uses a power supply circuit 50A instead of the power supply circuit 50 included in the reflector scanner 200. Note that, apart from the points mentioned above, the configuration is the same as that of the reflector scanner 200, so a description of those other configurations will be omitted.

[0052] The operation of the reflector scanner 300 will be explained below with reference to Figure 4.

[0053] Figure 4 is a top view of the reflector scanner 300, showing the direction of the current flowing through each coil of the reflector scanner 300, the direction of the magnetic field, and the direction of the Lorentz force at a given point in time, indicated by symbols or arrows.

[0054] The power supply circuit 50A supplies a drive current i2, which is an alternating current, to the coil L3. Furthermore, the power supply circuit 50A supplies a drive current i1, which is an alternating current, to the coil L1, and also supplies a drive current i1e, which is an alternating current with the same phase as the drive current i1, to the coil L2. As a result, at a given point in time, the drive current i1 flows clockwise through the coil L1, for example as shown by the arrow in Figure 4, and the drive current i1e flows counterclockwise through the coil L2, for example as shown by the arrow in Figure 4.

[0055] Therefore, a first Lorentz force is applied to the frame-shaped part FR at the left end of the frame 20 in accordance with the magnetic field B1 (indicated by the white arrow) from the magnet 31a and the driving current i1 (indicated by the black arrow) that crosses the magnetic field B1. Furthermore, a second Lorentz force is applied to the frame-shaped part FR at the right end of the frame 20 in accordance with the magnetic field B1e (indicated by the white arrow) from the magnet 31b and the driving current i1e (indicated by the black arrow) that crosses the magnetic field B1e. In this case, the direction in which the first Lorentz force is applied and the direction in which the second Lorentz force is applied are opposite to each other; that is, if one of the first and second Lorentz forces is applied in the direction facing the surface of the frame 20, the other is applied in the direction facing the back surface of the frame 20. As a result, a force (couple) is applied to the frame 20 that rotates the frame 20 about the second axis J2 as the central axis. Furthermore, since the drive currents i1 and i1e are alternating currents, the directions of the Lorentz forces acting on the right and left ends of the frame 20, respectively, remain in opposite directions while reversing with a period corresponding to the frequency of the alternating currents.

[0056] As a result, the frame 20 reverses the direction of rotation around the second axis J2 with a period corresponding to the frequency of the alternating current, and the torsion bars T1a and T1b, which are affected by this inertial force, twist, causing the mirror section MR to oscillate in the direction of rotation around the second axis J2.

[0057] In other words, in the reflective scanner 300, just like in the reflective scanner 200, the mirror section MR can be swung in the direction of rotation with the second axis J2 as the central axis.

[0058] Furthermore, the oscillating motion of the mirror section MR around the first axis J1, driven by the drive current i2, the second magnet pair (32a, 32b), and the coil L3, is the same as in the case of the reflector scanner 200 described above, so its explanation will be omitted.

[0059] Incidentally, according to the configuration shown in Figures 3A and 3B, the direction of the Lorentz forces acting on the bridging sections Ba and Bb, respectively, due to the driving current i2 flowing through the coil L3 and the magnetic field b1 (b1e) from the magnets 31a (31b), is the same. Therefore, the Lorentz forces acting on the two regions described above, depending on the driving current i2 flowing through the coil L3, do not form a couple with respect to rotational motion with the second axis J2 as the central axis.

[0060] Therefore, in the reflector scanner 300, there is no influence on the rotational movement of the frame 20 with the second axis J2 as its central axis, i.e., no crosstalk occurs due to the drive current i2 flowing through the coil L3. [Examples]

[0061] Figure 5 is a top view of a reflector scanner 400 according to a third embodiment of the present invention, viewed from above.

[0062] Furthermore, the reflective scanner 400 is identical to the reflective scanner 300 except that magnets 32aX and 32bX are used instead of magnets 32a and 32b shown in Figure 3A, and coil L3A is used instead of coil L3.

[0063] Therefore, the operation performed by the reflector scanner 400 employing this configuration will be explained below, focusing on the configuration of the magnets 32aX and 32bX as the second magnet pair, and the coil L3A.

[0064] As shown by the dashed line in Figure 5, coil L3A is wired in a loop or spiral shape to the frame-shaped portion of the frame 20 on the surface of the frame 20, surrounding the area where the mirror portion MR, coils L1 and L2 are located. One end of the wiring forming coil L3A is connected to the power supply circuit 50A via wiring installed on the surface of the torsion bar T2a, the support column 21a, and the base 40. The other end of the wiring forming coil L3A is also connected to the power supply circuit 50A via wiring installed on the surface of the torsion bar T2b, the support column 21b, and the base 40.

[0065] As shown in Figure 5, magnets 32aX and 32bX are positioned outside the frame 20, respectively, so as to straddle the wiring section of coil L3A that is routed along the direction of the first axis J1.

[0066] Furthermore, in the reflector scanner 400, as shown in Figure 5, only coils L1 and L2 are wired to the bridging sections Ba and Bb, and coil L3A is not wired.

[0067] Furthermore, as shown in Figure 5, the magnets 32aX and 32bX, which form the second magnet pair, are longer in the direction along the first axis J1 than the magnets 32a and 32b shown in Figure 3A. As a result, the wiring section of the coil L3A that crosses the magnetic field from the magnets 32aX and 32bX is longer than in the case of the reflector scanner 300 shown in Figure 3A, and the Lorentz force is increased accordingly. Therefore, even if the amount of drive current i2 is reduced, the mirror section MR can be reliably oscillated in the direction of rotation with the first axis J1 as the central axis, making it possible to reduce power consumption and miniaturize the entire device.

[0068] Furthermore, due to the structure of the reflector scanner 400 shown in Figure 5, there is no influence of the drive current i2 on the rotational movement of the frame 20 with the second axis J2 as its central axis, i.e., no crosstalk occurs. Also, on the surface of the frame 20, the direction of the Lorentz force generated in the region between the annular region Ra and the magnet 32aX (32bX) in accordance with the drive current i1 (i1e) is opposite to the direction of the Lorentz force generated in the region between the annular region Rb and the magnet 32aX (32bX). Therefore, with respect to the rotational direction of the frame 20 with respect to the first axis J1, the Lorentz force generated in the region between the annular region Ra and the magnet 32aX (32bX) cancels out the Lorentz force generated in the region between the annular region Rb and the magnet 32aX (32bX). Therefore, the drive currents i1 and i1e, which are responsible for the rotational motion of the frame 20 with the second axis J2 as its central axis, do not have any effect on the rotational motion of the frame 20 with the first axis J1 as its central axis, i.e., no crosstalk occurs. [Examples]

[0069] Figure 6A is a top view of the reflector scanner 500 according to the fourth embodiment of the present invention, viewed from above, and Figure 6B is a side view of the reflector scanner 500 viewed from the direction of the white arrow shown in Figure 6A.

[0070] Furthermore, the reflective scanner 500 is identical to the reflective scanner 200 shown in Figures 1A and 1B, except that coils L1 and L2 are connected in parallel, coil L3B is used instead of coil L3, and power supply circuit 50B is used instead of power supply circuit 50.

[0071] Therefore, the wiring configuration of coils L1, L2, and L3B in the reflector scanner 500 will be described.

[0072] As shown in Figure 6A, in the reflector scanner 500, similar to the reflector scanner 200 shown in Figure 1A, the annular region Ra of the frame 20 includes a coil L1, a support column 21a, and a torsion bar T2a, while the annular region Rb includes a coil L2, a support column 21b, and a torsion bar T2b. Furthermore, the central region between these annular regions Ra and Rb includes a mirror section MR, torsion bars T1a and T1b, and a coil L3B.

[0073] Here, one end and the other end of the wiring forming coil L1 are connected to the power supply circuit 50B via a pair of wires routed inside the surface of the torsion bar T2a, the support column 21a, and the base 40, respectively. One end and the other end of the wiring forming coil L2 are connected in parallel to coil L1.

[0074] Coil L3B, like coil L3, is wired in a loop or spiral manner around a pair of bridging sections Ba and Bb and a frame-shaped section FR, surrounding the mirror section MR. However, one end and the other end of the wiring forming coil L3B are connected to the power supply circuit 50B via a pair of wires installed inside the frame-shaped section FR on the outer circumference of the opening Ob, the surface of the torsion bar T2b, the support column 21b, and the base 40, respectively.

[0075] The power supply circuit 50B supplies a drive current i1 as an AC current to coil L1, and also supplies a drive current i2 as an AC current to coil L3B.

[0076] According to the configuration of the reflector scanner 500 shown in Figures 6A and 6B, the number of wires to be wired on the surfaces of the torsion bars T2a and T2b can be reduced from three to two, making it possible to reduce the width of these torsion bars T2a and T2b. Furthermore, according to the configuration shown in Figures 6A and 6B, the number of wires in the coil L3B that cross the magnetic field produced by magnet 32a in the section close to magnet 32a can be matched with the number of wires in the coil L3B that cross the magnetic field produced by magnet 32b in the section close to magnet 32b. This makes it possible to balance the torque of the Lorentz force that promotes clockwise rotation and counterclockwise rotation around the first axis J1 as the central axis. [Examples]

[0077] Figure 7 is a top view of a reflector scanner 600 according to a fifth embodiment of the present invention, viewed from above.

[0078] As shown in Figure 7, in the reflector scanner 600, the support column 21a is connected to bridge section Ba of a pair of bridging sections (Ba, Bb) via a torsion bar T2a that extends along the first axis J1. The support column 21b is connected to bridge section Bb of a pair of bridging sections (Ba, Bb) via a torsion bar T2b that extends along the first axis J1.

[0079] Aside from the points mentioned above, the configuration is the same as that of the reflector scanner 300 shown in Figures 3A and 3B.

[0080] According to the configuration shown in Figure 7, the position of the connection point between the torsion bar T2a (T2b) and the frame 20 is closer to the second axis J2 compared to, for example, the case where the torsion bar T2a (T2b) is connected to the frame-shaped part FR of the frame 20 as shown in Figure 3A. As a result, the amount of displacement due to the deflection of the torsion bar T2a (T2b) when the frame 20 rotates with the second axis J2 as its central axis is reduced. Therefore, the tensile stress on the torsion bar T2a (T2b) and the wiring on its surface is reduced, extending the lifespan of the torsion bar T2a (T2b) itself, and lowering the probability of wiring breakage on the torsion bar T2a (T2b), thus making it possible to extend the lifespan of the reflector scanner itself.

[0081] In the configuration shown in Figure 7, the first drive currents (i1, i1e) flowing through coils L1 and L2 rotate the frame 20 around the second axis J2, and the second drive current (i2) flowing through coil L3 rotates the frame 20 around the first axis J1.

[0082] However, two-axis rotational motion may also be achieved by placing only one single-wire coil on the frame 20A, where the support columns 21a (21b) as shown in Figure 7 are connected to the bridging section (Ba, Bb) via torsion bars T2a (T2b), and supplying a current to this single coil that superimposes the first and second drive currents described above.

[0083] Figure 8 is a top view of a reflective scanner 700, which is a modified version of the reflective scanner 600 shown in Figure 7, taken in consideration of the above points.

[0084] As shown in Figure 8, in the reflector scanner 700, a coil LQ consisting of a single wire is wired in a spiral or loop shape to each of the annular regions Ra and Rb of the frame 20A, and to the central region including the bridging sections Ba and Bb. In this case, one end of the wiring forming the coil LQ is led to the outside via a single wire wired inside or on the surface of the torsion bar T2a, the support column 21a, and the base 40, respectively. Furthermore, the other end of the wiring forming the coil LQ is led to the outside via a single wire wired inside or on the surface of the torsion bar T2b, the support column 21b, and the base 40, respectively.

[0085] Furthermore, in the reflector scanner 700, instead of using four magnets (31a, 31b, 32a, 32b), a pair of magnets 33a and 33b are arranged facing each other on the third axis J3 that extends diagonally across the frame 20A, sandwiching the frame 20A.

[0086] Here, the power supply circuit generates a drive current by superimposing the above-mentioned drive currents i1, i1e, and i2, and supplies this to one end and the other end of the wiring forming the coil LQ, causing the frame 20A to rotate in a rotational direction with the two axes (J1, J2) as the central axes. [Explanation of symbols]

[0087] 20, 20A frame 21a, 21b struts 31a, 31b First magnet pair 32a, 32b, 32aX, 32bX, 33a, 33b Second magnet pair 40 bases 50, 50A, 50B power supply circuit FR frame part L1, L2, L3, L3A, L3B, LQ coil MR Mirror Section T1a, T1b, T2a, T2b Torsion Bar

Claims

1. A frame having a frame-like portion extending along a plane 1, and held so as to be rotatable around a first axis along the plane 1, A mirror portion connected to the inside of the frame via a first elastic member extending along a second axis along the surface of the first, Multiple magnets that apply a magnetic field from each of the first and second ends of the frame-shaped portion that are opposite each other across the second axis, and from each of the third and fourth ends of the frame-shaped portion that are opposite each other across the first axis, A first drive unit that rotates the frame in a direction of rotation with the second axis as the central axis, A second drive unit that rotates the frame in a direction of rotation with the first axis as the central axis, Includes, The frame extends inside the frame so as to sandwich the first shaft, and has a pair of bridging parts that span across opposing portions of the frame that sandwich the second shaft. The first drive unit is, A first coil is wired in an annular manner along a first annular portion formed by one of the pair of bridging portions, the bridging portion closer to the first end, and the first end of the frame-shaped portion. The second coil is wired in an annular manner along a second annular portion formed by the other bridging portion of the pair of bridging portions that is closer to the second end and the second end of the frame-shaped portion, The second drive unit is, A reflector scanner characterized by including at least a third coil wired in the region between the pair of bridging portions of the frame-shaped portion.

2. A frame having a frame-like portion extending along a surface 1 and a pair of bridging portions extending inside the frame-like portion so as to sandwich a first axis, and spanning across portions facing each other on a second axis perpendicular to the first axis along the surface 1, and being held so as to be rotatable around the first axis, A mirror portion connected to the inside of the frame via a first elastic member extending along the second axis, Multiple magnets that apply a magnetic field from each of the first and second ends of the frame-shaped portion that are opposite each other across the second axis, and from each of the third and fourth ends of the frame-shaped portion that are opposite each other across the first axis, A coil wired to the frame-shaped portion and the pair of bridging portions of the frame, A first support column is installed inside the frame formed by the first annular portion, which is formed by the one bridging portion of the pair of bridging portions that is closer to the first end, and the first end of the frame-shaped portion. The second support column is installed inside the frame formed by the second annular portion, which is created by the other bridging portion of the pair of bridging portions that is closer to the second end, and the second end of the frame-shaped portion. The first support column is connected to the bridging portion 1 via an elastic member that extends along the first axis, A reflector scanner characterized in that the second support column is connected to the other bridging portion via an elastic member that extends along the first axis.

3. The reflector scanner according to claim 2, characterized in that the plurality of magnets are pairs of magnets arranged opposite to each other on a third axis different from the first axis and the second axis, which passes through the intersection of the first axis and the second axis along the surface 1, so as to sandwich the frame.

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