Optical devices

Abstract

In an optical device, the mirror substrate is driven by the actuator without joining the mirror substrate and the actuator together. [Solution] The optical device 10 includes a mirror substrate 12 having a reflective surface 12a and a back surface 12b, at least one actuator 14 having a movable end 14a that is displaced while in non-fixed contact with the back surface 12b of the mirror substrate 12, at least one first magnet 20 provided on the back surface 12b of the mirror substrate 12, and at least one second magnet 22 that is paired with the corresponding first magnet 20 and is positioned on the back surface 12b side of the mirror substrate 12 and at a distance from the corresponding first magnet 20, and generates a magnetic force between itself and the corresponding first magnet 20.

Description

Technical Field

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[0001] The present disclosure relates to an optical device that tilts or deforms a mirror substrate that reflects a light beam.

Background Art

[0002] Conventionally, an optical device that tilts a mirror substrate that reflects a light beam to control the irradiation direction of the light beam is known. Also, an optical device that deforms a mirror substrate that reflects a light beam to control the light intensity distribution of the light beam is known.

[0003] For example, Patent Document 1 discloses an optical device in which a plurality of actuators are joined to the back surface (the surface opposite to the reflecting surface) of a mirror substrate via an adhesive. By displacing the portion of the mirror substrate to which the plurality of actuators are joined, the entire mirror substrate tilts or the mirror substrate deforms.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the case of the optical device described in Patent Document 1, if multiple actuators repeatedly tilt or deform the mirror substrate at high speed, a load will be continuously applied to the joint between the mirror substrate and the actuator, which may eventually lead to fatigue failure of the joint, i.e., damage to the optical device. Furthermore, if the mirror substrate and actuator are joined via an adhesive, a portion of the driving force transmitted from the actuator to the mirror substrate may be used to deform the elastic adhesive. As a result, the control accuracy of the tilt angle of the mirror substrate or the control accuracy of the deformation of the mirror substrate may decrease, and the control accuracy of the light beam reflected from the mirror substrate may decrease. Moreover, if a high-power laser is used as the light beam, the deterioration of the adhesive joining the mirror substrate and actuator may be accelerated, potentially shortening the lifespan of the optical device.

[0006] Therefore, the present disclosure aims to provide an optical device in which a mirror substrate is driven by an actuator so that the entire mirror substrate tilts or the mirror substrate deforms, without joining the mirror substrate and the actuator together, and to drive the mirror substrate with the actuator. [Means for solving the problem]

[0007] To solve the above-mentioned problems, according to one aspect of this disclosure A mirror substrate having a reflective surface and a back surface opposite to the reflective surface, At least one actuator having a movable end that is displaced while in non-fixed contact with the back surface of the mirror substrate, At least one first magnet provided on the back surface of the mirror substrate, An optical device is provided, comprising at least one second magnet paired with the corresponding first magnet, positioned on the back side of the mirror substrate and at a distance from the corresponding first magnet, and generating a magnetic force between itself and the corresponding first magnet. [Effects of the Invention]

[0008] According to this disclosure, in an optical device in which a mirror substrate is driven by an actuator so that the entire mirror substrate tilts or the mirror substrate deforms, the mirror substrate can be driven by the actuator without joining the mirror substrate and the actuator. [Brief explanation of the drawing]

[0009] [Figure 1] Perspective view of the optical device according to Embodiment 1 of this disclosure [Figure 2] Cross-sectional view of the optical device according to Embodiment 1 along line AA shown in Figure 1. [Figure 3] A perspective view showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 1. [Figure 4] A top view showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 1. [Figure 5A] Conceptual diagram illustrating the behavior of multiple actuators that tilt a mirror substrate. [Figure 5B] Conceptual diagram illustrating the behavior of multiple actuators that deform a mirror substrate into a concave mirror shape. [Figure 6] A perspective view showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 2. [Figure 7] A top view showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 2. [Figure 8] A perspective view showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 3. [Figure 9] A top view showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 3. [Figure 10] A perspective view showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 4. [Figure 11] A top view showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 4. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, a more detailed description than necessary may be omitted. For example, a detailed description of well-known matters and a redundant description of substantially the same configuration may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0011] Note that the inventor(s) provides the accompanying drawings and the following description for those skilled in the art to fully understand the present disclosure, and does not intend to limit the subject matter described in the claims thereby.

[0012] Hereinafter, an imaging device according to an embodiment of the present disclosure will be described with reference to the drawings.

[0013] (Embodiment 1) FIG. 1 is a perspective view of an optical device according to Embodiment 1 of the present disclosure. Further, FIG. 2 is a cross-sectional view of the optical device according to Embodiment 1 along the line A-A shown in FIG. 1. Furthermore, FIGS. 3 and 4 are a perspective view and a top view showing the arrangement of an actuator and a pair of magnets. Note that the X-Y-Z orthogonal coordinate system shown in the figures is for facilitating the understanding of the present disclosure and does not limit the present disclosure. The Z-axis direction is, although details will be described later, the extending direction of the reference axis CA of the optical device 10, and the X-axis direction and the Y-axis direction are directions intersecting the reference axis CA.

[0014] As shown in FIGS. 1 to 4, the optical device 10 includes a mirror substrate 12, a plurality of actuators 14 for driving the mirror substrate 12, and a base member 16 for supporting the plurality of actuators 14.

[0015] As shown in FIGS. 1 and 2, the mirror substrate 12 is a thin and lightweight substrate, and includes a reflecting surface 12a that reflects the light beam L and a back surface 12b opposite to the reflecting surface 12a. The mirror substrate 12 is made of a material such as synthetic quartz, silicon, silicon carbide, etc., and has a thickness of, for example, 1 mm. Note that the material and thickness of the mirror substrate 12 are not limited to these.

[0016] In the case of the first embodiment, the mirror substrate 12 is circular. The reference axis CA passes through the center of the mirror substrate 12. Note that the shape of the mirror substrate 12 is not limited to a circular shape, and may be, for example, a square shape.

[0017] In the case of the first embodiment, the reflecting surface 12a of the mirror substrate 12 is a dielectric layer film formed on the surface of the mirror substrate 12 by a method such as a vapor deposition method. Note that the reflecting surface 12a is not limited to this, and may be a metal film such as gold or silver.

[0018] The plurality of actuators 14 are configured to drive the mirror substrate 12 so that the entire mirror substrate 12 tilts or the mirror substrate 12 is deformed. In the case of the first embodiment, three actuators 14 drive the mirror substrate 12. In the case of the first embodiment, as shown in FIGS. 3 and 4, the optical device 10 has three actuators 14.

[0019] In the case of the first embodiment, each of the plurality of actuators 14 is a piezoelectric actuator formed by laminating a plurality of piezoelectric elements. By controlling the applied voltage of the piezoelectric element, it expands and contracts in the extending direction (Z-axis direction) of the reference axis CA. For example, the laminate of the plurality of piezoelectric elements is covered and protected by an exterior case made of an aluminum alloy, resin, etc.

[0020] Furthermore, each of the multiple actuators 14 is equipped with a movable end 14a that moves in the direction of extension of the reference axis CA (Z-axis direction) and a fixed end 14b. The movable end 14a of each of the multiple actuators 14 moves in the direction of extension of the reference axis CA (Z-axis direction) due to the expansion and contraction of the actuator itself. In other words, the reference axis CA extends in the direction of displacement of the movable end 14a.

[0021] Furthermore, the movable ends 14a of each of the multiple actuators 14 are displaced while in non-fixed contact with the back surface 12b of the mirror substrate 12. Here, "non-fixed" means that the movable ends 14a are not joined to the mirror substrate 12, and the mirror substrate 12 can detach from the movable ends 14a non-destructively. Therefore, in this embodiment 1, the contact between the mirror substrate 12 and the movable ends 14a of each of the multiple actuators 14 is maintained by the weight of the mirror substrate 12.

[0022] In this embodiment 1, the movable end 14a of each of the multiple actuators 14 is hemispherical. Therefore, the movable end 14a makes substantially point contact with the back surface 12b of the mirror substrate 12. As a result, the frictional resistance generated between the movable end 14a and the mirror substrate 12 when the multiple actuators 14 drive the mirror substrate 12 is small.

[0023] In this embodiment 1, the fixed end 14b of each of the multiple actuators 14 is fixed to and supported by the base member 16.

[0024] The base member 16 is made from a highly rigid material such as stainless steel (SUS). The base member 16 faces the back surface 12b of the mirror substrate 12, spaced apart to allow for the placement of multiple actuators 14. In this embodiment 1, the base member 16 is circular, but its shape is not limited.

[0025] For example, each actuator 14 is fixed and supported to the base member 16 by joining its metal outer casing to the planar support surface 16a of the base member 16 by welding or other means. The method of fixing each actuator 14 to the base member 16 is not limited to welding. Furthermore, each actuator 14 is fixed to the base member 16 such that its extension and retraction direction is parallel to the normal direction of the support surface 16a of the base member 16.

[0026] Furthermore, as shown in Figures 2 and 3, the optical device 10 has a pair of first and second magnets 20, 22 for supporting the mirror substrate 12. The pair of first and second magnets 20, 22 are, for example, cylindrical neodymium magnets.

[0027] One of the first magnets 20 is provided on the back surface 12b of the mirror substrate 12. The other, second magnet 22 is positioned on the back surface 12b side of the mirror substrate 12, spaced apart from the first magnet 20. In this embodiment 1, the first magnet 20 and the second magnet 22 are positioned opposite each other with a space between them in the direction of extension of the reference axis CA (Z-axis direction).

[0028] Furthermore, in this embodiment 1, the magnetic force generated between the first magnet 20 and the second magnet 22 is a repulsive force RF. As a result, the mirror substrate 12 on which the first magnet 20 is provided is magnetically levitated by the second magnet 22 and is supported by the second magnet 22 without contact.

[0029] In this embodiment 1, in order to position and maintain the second magnet 22 at a distance from the first magnet 20 provided on the back surface 12b of the mirror substrate 12, the second magnet 22 is supported by a columnar member 24. Specifically, the columnar member 24 extends from the base member 16 toward the mirror substrate 12, and the magnet 22 is attached to its tip 24a. The material of the columnar member 24 does not matter, as long as it has the rigidity to not deform due to the repulsive force RF between the first magnet 20 and the second magnet 22.

[0030] In this embodiment 1, to ensure that the mirror substrate 12, which is supported in a magnetically levitated state by a pair of first and second magnets 20 and 22, makes contact with the movable ends 14a of each of the multiple actuators 14, the columnar member 24 is configured to have an adjustable protrusion length from the base member 16. Specifically, as shown in Figure 2, the columnar member 24 has a male threaded portion 24b at the end opposite to the tip 24a. A female threaded hole 16b that engages with this male threaded portion 24b is formed in the base member 16. By adjusting the engagement length of the male threaded portion 24b with respect to the female threaded hole 16b, the protrusion length of the columnar member 24 from the base member 16 is adjusted. As a result, the distance between the first magnet 20 and the second magnet 22 can be adjusted to a distance at which the mirror substrate 12 makes contact with the movable ends 14a of each of the multiple actuators 14 while being magnetically levitated by the pair of first and second magnets 20 and 22.

[0031] As shown in Figure 4, in this embodiment 1, the first magnet 20 (and the second magnet 22) are positioned on the reference axis CA, i.e., in the central part of the circular mirror substrate 12, when viewed in the direction of extension of the reference axis CA (Z-axis direction). In contrast, the multiple actuators 14 are positioned to surround the first magnet 20 (and the second magnet 22) when viewed in the direction of extension of the reference axis CA (Z-axis direction). Specifically, the multiple actuators 14 are arranged at the same intervals on a circumference R centered on the reference axis CA. Therefore, the mirror substrate 12 is supported at three points by multiple (three) actuators 14 at its outer edge, while its central part is supported in a magnetically levitated state by a pair of first and second magnets 20 and 22.

[0032] In this way, the mirror substrate 12, supported by multiple actuators 14 and a pair of first and second magnets 20 and 22, tilts or deforms by controlling each of the multiple actuators 14.

[0033] Figure 5A is a conceptual diagram illustrating the behavior of multiple actuators that tilt the mirror substrate. Figure 5B is a conceptual diagram illustrating the behavior of multiple actuators that deform the mirror substrate into a concave mirror shape.

[0034] First, each of the multiple actuators 14 is controlled by a controller (not shown). For example, in this embodiment 1, since the actuators 14 are piezoelectric actuators, the controller is a circuit board that is electrically connected to each of the multiple actuators 14 and controls the applied voltage to each of the multiple actuators 14.

[0035] As shown in Figure 5A, when no voltage is applied to any of the actuators 14, the mirror substrate 12 is not tilted. That is, when the reference axis CA extends in the vertical direction, the mirror substrate 12 is in a horizontal position.

[0036] As shown in Figure 5A, when a positive voltage (+V) is applied to one actuator 14, the movable part 14a of that actuator 14 is displaced by +Δd. At this time, since the movable end 14a and the mirror substrate 12 are not joined, the contact position between them changes. As a result, the mirror substrate 12 becomes tilted.

[0037] As shown in Figure 5A, the repulsive force RF between the pair of first and second magnets 20 and 22 prevents the central portion of the mirror substrate 12 from bending and deforming convexly toward the back surface 12b when the mirror substrate 12 is not tilted. Furthermore, even when the mirror substrate 12 is tilted, the repulsive force RF between the pair of first and second magnets 20 and 22 prevents the central portion of the mirror substrate 12 from bending and deforming convexly toward the back surface 12b. In other words, the repulsive force RF between the pair of first and second magnets 20 and 22 supports the mirror substrate 12 so that the reflective surface 12a remains planar.

[0038] As shown in Figure 5B, when a positive voltage (+V) is applied to all actuators 14, each movable end 14a is displaced by +Δd. At this time, the contact position between the movable end 14a and the mirror substrate 12 changes. As a result, the outer peripheral end portion of the mirror substrate 12 that contacts the movable end 14a is displaced toward the reflective surface 12a. In contrast, the central portion of the mirror substrate 12 is suppressed from being displaced toward the reflective surface 12a by its own weight and the weight of the first magnet 20. As a result, the mirror substrate 12 bends and deforms so that its reflective surface 12a becomes concave, i.e., it becomes a concave mirror. In this case, the repulsive force RF between the pair of first and second magnets 20 and 22 plays a role in suppressing excessive bending deformation of the mirror substrate 12.

[0039] Furthermore, when the controller applies a voltage such as a sinusoidal waveform to each of the multiple actuators 14, causing the multiple actuators 14 to repeatedly expand and contract, that is, when the movable end 14a reciprocates, the contact position between the back surface 12b of the mirror substrate 12 and the movable end 14a repeatedly changes. Because the contact point moves, virtually no repeated stress is generated in the portion of the mirror substrate 12 that contacts the actuator 14.

[0040] In this embodiment 1, the mirror substrate 12 contacts the movable ends 14a of a plurality of actuators 14 and is supported in a magnetically levitated state by a pair of first and second magnets 20 and 22. That is, the mirror substrate 12 is not fixed in the optical device 10. Therefore, the optical device 10 is used in a position in which the mirror substrate 12 contacts all of the actuators 14 by its own weight. For this reason, for example, during transportation or installation of the optical device 10, the mirror substrate 12 may move from a position where it can contact all of the movable ends 14a of the actuators 14.

[0041] To address this, in this embodiment 1, as shown in Figures 1 and 2, the optical device 10 has a holder 26 for maintaining the mirror substrate 12 in a position opposite to the movable ends 14a of all actuators 14. As shown in Figure 2, in this embodiment 1, the holder 26 is a cylindrical member with an annular groove 26a formed on its inner circumferential surface to accommodate the outer circumferential end of the mirror substrate 12. The annular groove 26a is large enough to allow the mirror substrate 12 to tilt and deform. With such a holder 26, the mirror substrate 12 is maintained in a position opposite to the movable ends 14a of the multiple actuators 14. Note that the holder 26 is not limited to a cylindrical shape; any shape that can restrict the movement of the mirror substrate 12 in the direction of extension of the reference axis CA (Z-axis direction) and in directions perpendicular to the reference axis CA (X-axis direction, Y-axis direction) is acceptable in order to maintain the mirror substrate 12 in a position opposite to the movable ends 14a of all actuators 14.

[0042] According to this embodiment 1, in an optical device in which a mirror substrate is driven by an actuator so that the entire mirror substrate tilts or the mirror substrate deforms, the mirror substrate can be driven by the actuator without joining the mirror substrate and the actuator.

[0043] In other words, because the pair of first and second magnets 20 and 22 support the mirror substrate 12 without contact, the entire mirror substrate 12 can be tilted while maintaining the planar state of the reflective surface 12a, without having to bond each of the multiple actuators 14 to the mirror substrate 12 via adhesive. Furthermore, the mirror substrate 12 can be deformed into a convex mirror shape or a concave mirror shape.

[0044] As a result, the problems that arose in conventional optical devices due to the bonding of the mirror substrate and the actuator via an adhesive can be eliminated. Specifically, the problems of fatigue failure at the joint between the mirror substrate and the actuator due to continuous heavy load, the problem of a portion of the driving force transmitted from the actuator to the mirror substrate being used to deform the elastic adhesive bonding the mirror substrate and the actuator, and the problem of deterioration of the adhesive bonding the mirror substrate and the actuator due to the light beam reflected by the mirror substrate do not occur in the optical device 10 according to this embodiment 1.

[0045] (Embodiment 2) The optical device according to this second embodiment differs from the optical device according to the first embodiment described above in terms of the number and arrangement of actuators and magnets. Therefore, this second embodiment will be described focusing on the differences. Note that components of the second embodiment that are substantially the same as those of the first embodiment described above are denoted by the same reference numerals.

[0046] Figures 6 and 7 are perspective and top views, respectively, showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 2.

[0047] As shown in Figures 6 and 7, the optical device 110 according to this second embodiment is provided with two actuators 14 and a pair of first and second magnets 20 and 22. The pair of first and second magnets 20 and 22 and the actuators 14 are arranged to surround the center of the mirror substrate 12 through which the reference axis CA passes, when viewed in the direction of extension of the reference axis CA (Z-axis direction). Specifically, the pair of first and second magnets 20 and 22 and the actuators 14 are arranged on the same circumference R centered on the center of the mirror substrate 12, with the same spacing between them.

[0048] In this second embodiment, the central portion of the mirror substrate 12 is not supported. Also, the pair of first and second magnets 20 and 22 and the actuator 14 are arranged on the same circumference R. Therefore, in the optical device 110 according to this second embodiment, the mirror substrate 12 only tilts as a whole and does not deform into a convex or concave mirror shape.

[0049] In this second embodiment, as in the first embodiment described above, the mirror substrate can be driven by the actuator without joining the mirror substrate and the actuator.

[0050] (Embodiment 3) The optical device according to this third embodiment differs from the optical device according to the first embodiment described above in terms of the number and arrangement of actuators and magnets. Therefore, this third embodiment will be described focusing on the differences. Note that components of the third embodiment that are substantially the same as those of the first embodiment described above are denoted by the same reference numerals.

[0051] Figures 8 and 9 are perspective and top views, respectively, showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 3.

[0052] As shown in Figures 8 and 9, the optical device 210 according to this third embodiment is provided with one actuator 14 and two pairs of first and second magnets 20 and 22. The pair of first and second magnets 20 and 22 and the actuator 14 are arranged to surround the center of the mirror substrate 12 through which the reference axis CA passes, when viewed in the direction of extension of the reference axis CA (Z-axis direction). Specifically, the pair of first and second magnets 20 and 22 and the actuator 14 are arranged on the same circumference R centered on the center of the mirror substrate 12, at the same intervals.

[0053] In this third embodiment, the central portion of the mirror substrate 12 is not supported. Also, the pair of first and second magnets 20 and 22 and the actuator 14 are arranged on the same circumference R. Therefore, in the optical device 210 according to this third embodiment, the mirror substrate 12 only tilts as a whole and does not deform into a convex or concave mirror shape.

[0054] In this third embodiment, as in the first embodiment described above, the mirror substrate can be driven by the actuator without joining the mirror substrate and the actuator.

[0055] (Embodiment 4) The optical device according to this fourth embodiment differs from the optical device according to the first embodiment described above in terms of the number and arrangement of actuators and magnets. Therefore, this fourth embodiment will be described focusing on the differences. Note that components of the fourth embodiment that are substantially the same as those of the first embodiment described above are denoted by the same reference numerals.

[0056] Figures 10 and 11 are a perspective view and a top view, respectively, showing the arrangement of the actuator and a pair of magnets in the optical device according to Embodiment 4.

[0057] As shown in Figures 10 and 11, the optical device 310 according to this embodiment 4 is provided with three actuators 14 and five pairs of first and second magnets 20 and 22. The pairs of first and second magnets 20 and 22 and the actuators 14 are arranged to surround the center of the mirror substrate 12 through which the reference axis CA passes, when viewed in the direction of extension of the reference axis CA (Z-axis direction). Specifically, the actuators 14 are arranged at the same intervals on a first circumference R1 centered on the center of the mirror substrate 12. Also, the pairs of first and second magnets 20 and 22 are arranged at the same intervals on a second circumference R2 that is concentric with the first circumference R1, centered on the center of the mirror substrate 12.

[0058] In the optical device 310 according to this fourth embodiment, the second circumference R2 surrounds the first circumference R1. That is, multiple pairs of first and second magnets 20 and 22 surround multiple actuators 14. With this arrangement, the mirror substrate 12 can be tilted or deformed significantly with the stroke of the movable end 14a of the small actuator 14. Therefore, the mirror substrate 12 can be tilted or deformed at high speed.

[0059] In this fourth embodiment, as in the first embodiment described above, the mirror substrate can be driven by the actuator without joining the mirror substrate and the actuator together.

[0060] Although several embodiments have been described above, the embodiments of this disclosure are not limited to these.

[0061] For example, in the first embodiment described above, the pair of first and second magnets 20 and 22 are neodymium magnets. However, the embodiments of this disclosure are not limited thereto. The pair of first and second magnets may be, for example, samarium cobalt magnets. Also, the pair of first and second magnets 20 and 22 may be electromagnets.

[0062] Furthermore, in the first embodiment described above, the first and second magnets 20 and 22 are cylindrical. However, the embodiments of this disclosure are not limited to this. For example, the first and second magnets may be cylindrical. In this case, the cylindrical first magnet is mounted along the outer circumference on the back surface of the mirror substrate. The cylindrical second magnet is provided on the base member so as to face the first magnet and surround the plurality of actuators.

[0063] Furthermore, in the first embodiment described above, the magnetic force generated between the first and second magnets 20 and 22 is repulsive. However, the embodiments of this disclosure are not limited to this. The magnetic force generated between the first and second magnets may be attractive. In this case, the attractive force can maintain contact between the mirror substrate and the movable end of the actuator. Therefore, the optical device can be used even when, for example, the reflective surface of the mirror substrate is facing downwards. However, the mirror substrate needs to be rigid so that the attractive force does not cause the first and second magnets to approach each other and come into contact.

[0064] Furthermore, in the first embodiment described above, the plurality of actuators 14 are piezoelectric actuators. However, the embodiments of this disclosure are not limited thereto. The embodiments of this disclosure may be any actuator having a movable end that is displaced in one direction in order to drive the mirror substrate.

[0065] Furthermore, in the first embodiment described above, the movable ends 14a of the multiple actuators 14 are hemispherical. However, the embodiments of this disclosure are not limited to this. The movable ends of the multiple actuators may be planar, and hemispherical protrusions that contact the movable ends may be provided on the back surface of the mirror substrate.

[0066] Furthermore, in the first embodiment described above, as shown in Figure 2, in order to adjust the distance between the first magnet 20 and the second magnet 22, a male threaded portion 24b provided on the columnar member 24 supporting the second magnet 22 engages with a female threaded hole 16b formed in the base member 16. However, the means for adjusting the distance between the first magnet 20 and the second magnet 22 are not limited to this. Any means is acceptable as long as the position of the second magnet relative to the first magnet can be adjusted and the second magnet can be maintained in the adjusted position.

[0067] As shown in embodiments 1 to 4 above, in the optical apparatus according to the embodiments of this disclosure, the sum of the number of actuators 14 and the number of pairs of first and second magnets 20 and 22 is at least three. Also, in view in the direction of extension of the reference axis CA (Z-axis direction), that is, in the direction of displacement of the movable end 14a of the actuator 14, the actuator 14 and the pair of first and second magnets 20 and 22 are arranged to surround the center of the mirror substrate 12. With these numbers and layouts, the actuator 14 and the pair of first and second magnets 20 and 22 are able to support the mirror substrate 12.

[0068] In other words, the imaging device according to the embodiment of the present disclosure is, in a broad sense, an optical device comprising: a mirror substrate having a reflective surface and a back surface opposite to the reflective surface; at least one actuator having a movable end that is displaced while in non-fixed contact with the back surface of the mirror substrate; at least one first magnet provided on the back surface of the mirror substrate; and at least one second magnet that is paired with the corresponding first magnet and is positioned on the back side of the mirror substrate and at a distance from the corresponding first magnet, and generates a magnetic force between itself and the corresponding first magnet.

[0069] As described above, the embodiments described in this disclosure have been explained as examples of the technology. For this purpose, drawings and a detailed description are provided. Therefore, among the components described in the drawings and detailed description, there may be not only components that are essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the technology described above. For this reason, the mere fact that these non-essential components are described in the drawings and detailed description should not be immediately assumed to be essential.

[0070] Furthermore, since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the scope of the claims or equivalents thereof. [Industrial applicability]

[0071] This disclosure is applicable to optical devices that tilt or deform mirrors that reflect light beams. [Explanation of Symbols]

[0072] 10 Optical equipment 12 Mirror substrate 12a Reflective surface 12b Back 14 Actuators 14a Movable end 20 The first magnet 22 The second magnet

Claims

1. A mirror substrate having a reflective surface and a back surface opposite to the reflective surface, At least one actuator having a movable end that is displaced while in non-fixed contact with the back surface of the mirror substrate, At least one first magnet provided on the back surface of the mirror substrate, An optical device comprising: at least one second magnet paired with the corresponding first magnet, positioned on the back side of the mirror substrate and at a distance from the corresponding first magnet, and generating a magnetic force between itself and the corresponding first magnet.

2. In a view of the displacement direction of the movable end, the first magnet is positioned in the central part of the mirror substrate. The optical device according to claim 1, wherein, in the view in the direction of displacement, a plurality of actuators surround the first magnet.

3. The optical apparatus according to claim 1, wherein, in view of the direction of displacement of the movable end, at least one of the first magnets and at least one actuator surround the center of the mirror substrate.

4. The optical device according to claim 1, wherein, in view of the displacement direction of the movable end, a plurality of actuators are arranged on a first circumference, and a plurality of first magnets are arranged on a second circumference concentric with the first circumference.

5. The optical apparatus according to claim 4, wherein the second circumference surrounds the first circumference.

6. A base member that supports the fixed end of the actuator, The optical device according to claim 1, further comprising a columnar member extending from the base member and supporting the second magnet at its tip.

7. The columnar member is equipped with a male threaded portion, The optical device according to claim 6, wherein the base member has a female screw hole that engages with the male screw portion.

8. The optical device according to claim 1, wherein the movable end of the actuator is hemispherical.

9. The optical apparatus according to claim 1, wherein the magnetic force generated between at least one of the first magnets and the corresponding second magnet is a repulsive force.

10. The optical apparatus according to claim 1, wherein the magnetic force generated between at least one first magnet and the corresponding second magnet is an attractive force.

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