Mirror tilting device

Abstract

The present invention provides a mirror tilting device that can dissipate heat accumulated in the tilting part without restricting the tilting motion of the tilting part. [Solution] This mirror tilting device 100 comprises a tilting part 10, a support part 22 that supports the tilting part 10, and a heat dissipation part 40. The heat dissipation part 40 is elastically deformable, is provided separately from the support part 22, and is located on the opposite side of the tilting part 10 from the reflective mirror 12 so as to dissipate the heat accumulated in the tilting part 10 by the tilting part 10 absorbing electromagnetic waves.

Description

Technical Field

[0001] The present invention relates to a mirror tilting device, and more particularly to a mirror tilting device that exhausts heat accumulated in a tilting part by absorbing electromagnetic waves.

Background Art

[0002] Conventionally, a mirror tilting device that exhausts heat accumulated in a tilting part by absorbing electromagnetic waves has been known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a mirror tilting device including a mirror body (tilting part) that reflects electromagnetic waves, a heat conduction part that supports the mirror body, and a support structure to which the heat conduction part is connected. This mirror tilting device exhausts the heat accumulated in the mirror body to the support structure through the heat conduction part by absorbing the electromagnetic waves that have not been reflected.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, although not specified in Patent Document 1, in a mirror tilting device that exhausts the heat accumulated in a mirror body through a heat conduction part as described in Patent Document 1, when the electromagnetic waves become strong, the heat accumulated in the mirror body without being reflected also increases, so it is necessary to increase the cross-sectional area of the heat conduction part for heat exhaust. However, if the cross-sectional area of the heat conduction part (support part) that supports the mirror body is increased, the driving force for tilting the mirror body (tilting part) may increase, restricting the tilting operation of the mirror body part. Therefore, a mirror tilting device that can exhaust the heat accumulated in the tilting part without restricting the tilting operation of the tilting part is desired.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide a mirror tilting device that can dissipate heat accumulated in the tilting part without restricting the tilting movement of the tilting part. [Means for solving the problem]

[0007] To achieve the above objective, a mirror tilting device according to one aspect of this invention comprises a tilting part provided with a reflective mirror that reflects electromagnetic waves and configured to be tiltable, a support part that supports the tilting part, and an elastically deformable heat dissipation part provided separately from the support part and on the opposite side of the tilting part from the reflective mirror so as to dissipate the heat accumulated in the tilting part by the tilting part absorbing electromagnetic waves.

[0008] In a mirror tilting device according to one aspect of this invention, an elastically deformable heat dissipation section is provided separately from the support section, allowing heat accumulated in the tilting section to be dissipated without restricting the tilting motion of the tilting section. Note that "without restricting the tilting motion" is a broad concept that includes cases where the tilting motion is not restricted at all and cases where the tilting motion is restricted only slightly.

[0009] In the mirror tilting device according to the first aspect described above, preferably, a base portion is provided at a predetermined distance from the tilting portion and has a volume larger than that of the tilting portion, and the heat dissipation portion is provided so as to be in contact with both the tilting portion and the base portion in order to dissipate the heat accumulated in the tilting portion by transferring it to the base portion. With this configuration, the heat dissipation portion can effectively dissipate the heat accumulated in the tilting portion by transferring it to the base portion which has a volume larger than that of the tilting portion. Furthermore, even in cases where heat dissipation into the atmosphere is almost impossible, such as in a vacuum, the heat accumulated in the tilting portion can be easily dissipated.

[0010] In this case, preferably, the heat dissipation section is provided between the tilting section and the base section. With this configuration, compared to the case where the heat dissipation section is provided to bypass the space between the tilting section and the base section rather than being provided between the tilting section and the base section, the distance over which heat is conducted from the tilting section to the base section via the heat dissipation section is reduced, so that the heat accumulated in the tilting section can be dissipated more efficiently by the heat dissipation section.

[0011] In a mirror tilting device in which the heat dissipation section is provided between the tilting section and the base section, preferably, the external shape of the heat dissipation section elastically deforms in accordance with the shape of the space between the tilting section and the base section, which changes as the tilting section tilts. With this configuration, the heat dissipation section can always be in contact with both the tilting section and the base section when the tilting section tilts. This prevents a decrease in the heat dissipation efficiency of the heat dissipation section or an imbalance in heat dissipation occurring in each part of the tilting section, which can result from the heat dissipation section separating from at least one of the tilting section and the base section. Furthermore, even if the space between the tilting section and the base section narrows due to the tilting of the tilting section, the heat dissipation section does not obstruct the tilting of the tilting section.

[0012] In this case, preferably, the external shape of the heat dissipation section changes in accordance with the shape of the space between the tilting section and the base section, which changes as the tilting section tilts. With this configuration, even if the space between the tilting section and the base section widens or narrows as the tilting section tilts, the external shape of the heat dissipation section can be changed so that a constant weight of heat dissipation section is always present in the space between the tilting section and the base section.

[0013] In a mirror tilting device in which the heat dissipation section is provided to contact both the tilting section and the base section so as to dissipate heat by transferring the heat accumulated in the tilting section to the base section, preferably, the thermal conductivity of the heat dissipation section is higher than that of the tilting section and the base section. With this configuration, the heat accumulated in the tilting section can be more effectively transferred to the base section by the heat dissipation section having a relatively high thermal conductivity.

[0014] In the mirror tilting device with the above-described surface, preferably, the heat dissipation section includes carbon nanotubes or boron nitride nanotubes. By including carbon nanotubes or boron nitride nanotubes, which have a higher thermal conductivity than metals such as aluminum or copper that have good thermal conductivity, the heat accumulated in the tilting section can be effectively dissipated by transferring it to the atmosphere or other structures.

[0015] In this case, preferably, the heat dissipation section includes an aggregate of twisted fibrous carbon nanotubes or boron nitride nanotubes. With this configuration, even if the shape of the space in which the heat dissipation section is provided changes due to the tilting motion of the tilting section, the external shape of the heat dissipation section can be easily elastically deformed in response to the change in the shape of the space in which the heat dissipation section is provided, without restricting the tilting motion of the tilting section.

[0016] In the mirror tilting device in which the heat dissipation section contains carbon nanotubes, preferably, the carbon nanotubes are formed on the surface of the tilting section opposite to the reflective mirror by chemical vapor deposition. With this configuration, the heat dissipation section is chemically bonded to the tilting section, so it is possible to reliably suppress the decrease in the heat dissipation efficiency of the heat dissipation section caused by the separation of the heat dissipation section and the tilting section.

[0017] In a mirror tilting device in which the heat dissipation section is provided to contact both the tilting section and the base section so as to dissipate heat by transferring the heat accumulated in the tilting section to the base section, preferably, the support section has one end connected to the tilting section and the other end connected to the base section. With this configuration, there is no need to provide a new structure that connects the support section to the opposite side of the tilting section, so that the number of parts in the mirror tilting device can be suppressed and the structure of the mirror tilting device can be suppressed. [Effects of the Invention]

[0018] According to the present invention, as described above, it is possible to exhaust the heat accumulated in the tilting part without restricting the tilting operation of the tilting part.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 8 is a schematic view showing the overall configuration of a mirror tilting device according to an embodiment of the present invention. [Figure 2] FIG. 11 is a plan view of a mirror tilting device according to an embodiment of the present invention. [Figure 3] FIG. 14 is a plan view of a tilting mechanism according to an embodiment of the present invention. [Figure 4] FIG. 17 is a cross-sectional view of the mirror tilting device taken along line IV-IV of FIG. 2 ((a): state where the tilting part is not tilted, (b): enlarged view of part A in (a), (c): state where the tilting part is tilted, (d): enlarged view of part B in (c), (e): enlarged view of part C in (c)). [Figure 5] FIG. 20 is a cross-sectional view showing a piezoelectric drive type mirror tilting device according to a first modification of an embodiment of the present invention. [Figure 6] FIG. 23 is a cross-sectional view showing a mirror tilting device according to a second modification of an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, an embodiment embodying the present invention will be described based on the drawings.

[0021] Referring to FIGS. 1 to 4(b), the configuration of the mirror tilting device 100 according to the present embodiment will be described.

[0022] (Configuration of the mirror tilting device) As shown in Figure 1, the mirror tilting device 100 comprises a tilting section 10, a tilting mechanism 20, a main body 30, and a heat dissipation section 40. The mirror tilting device 100 is, for example, a MEMS (Micro Electro Mechanical Systems) mirror used in a vacuum. In Figure 1, the left-right direction (one direction in the horizontal plane) of the mirror tilting device 100 is defined as the X direction. The up-down direction (vertical direction) of the mirror tilting device 100 is defined as the Z direction. The upward direction is defined as the Z1 direction, and the downward direction as the Z2 direction. The direction perpendicular to the X and Z directions (the other direction in the horizontal plane) of the mirror tilting device 100 is defined as the Y direction. One direction in the X direction is defined as the X1 direction, and the other direction as the X2 direction, and one direction in the Y direction is defined as the Y1 direction, and the other direction as the Y2 direction.

[0023] As shown in Figure 2, the tilting part 10 has a circular shape in plan view. As shown in Figure 4(a), the tilting part 10 includes a substrate 11, a reflective mirror 12, and a driven part 13. The tilting part 10 is tiltable. The tilting operation of the tilting part 10 will be described later.

[0024] The substrate 11 includes a flat portion 11a and a protruding portion 11b. The flat portion 11a has a disc shape. The protruding portion 11b protrudes downward (Z2 direction) along the thickness direction (Z direction) of the flat portion 11a in the non-tilting state from the center of the flat portion 11a. The protruding portion 11b has a flat shape with a diameter smaller than the diameter of the flat portion 11a. The flat portion 11a and the protruding portion 11b are integrally formed from a material containing, for example, silicon.

[0025] As shown in Figure 4(a), the reflective mirror 12 is located on the opposite side of the substrate 11 from the protruding portion 11b. The reflective mirror 12 is stacked on the upper side (Z1 side) of the substrate 11 along the thickness direction (Z direction) of the non-tilting flat portion 11a. The reflective mirror 12 is made of, for example, gold (Au) and is capable of reflecting electromagnetic waves such as irradiated light.

[0026] As shown in Figure 4(a), the driven portion 13 is located in the center of the surface 11c of the protruding portion 11b opposite to the flat plate portion 11a. The driven portion 13 is attached to the protruding portion 11b by, for example, an adhesive. The driven portion 13 is, for example, a permanent magnet.

[0027] As shown in Figure 2, the tilting mechanism 20 has a square shape with side lengths equal to the diameter of the tilting part 10 in a plan view. As shown in Figure 3, the tilting mechanism 20 includes a base portion 21 and a support portion 22. The base portion 21 supports (fixes) the support portion 22 so that it does not move. The support portion 22 includes an arm portion 23 and a mounting portion 24, and the arm portion 23 connects the base portion 21 and the mounting portion 24, which is located in the center of the tilting mechanism 20. There are multiple arm portions 23, which are located at equal angular intervals along the circumferential direction of the annular mounting portion 24. For example, there are four arm portions 23. The base portion 21 and the support portion 22 are integrally formed from a material including, for example, silicon. In this embodiment, the base portion 21 has a volume larger than the volume of the tilting part 10.

[0028] As shown in Figure 4(a), the tilting part 10 is placed on the mounting part 24, and the support part 22 supports the tilting part 10 by joining the mounting part 24 and the tilting part 10. The joining of the mounting part 24 and the tilting part 10 can be done using adhesive bonding, or wafer joining methods such as direct bonding or surface activation bonding. In other words, in this embodiment, one end of the support part 22 is connected to the tilting part 10 and the other end is connected to the base part 21. Furthermore, the length of the base part 21 along the thickness direction (Z direction) of the tilting part 10 in the non-tilting state is greater than the length of the support part 22 along the thickness direction (Z direction) of the tilting part 10 in the non-tilting state. Therefore, on the side of the support part 22 opposite to the tilting part 10 (Z2 side), there is a space S surrounded by the base part 21. In this embodiment, the tilting portion 10 and the base portion 21 are spaced apart by a distance D along the thickness direction (Z direction) of the non-tilting tilting portion 10. Note that the distance D is an example of the "predetermined distance" in the claims. Also, as shown by the dashed line in Figure 3, in a plan view, the side surface 11d of the protruding portion 11b is located outside the annular mounting portion 24, and the side surface 13a of the driven portion 13 is located inside the annular mounting portion 24.

[0029] As shown in Figures 1 and 4(a), the main body 30 is located on the lower side (Z2 side) of the tilting mechanism 20. The main body 30 is formed from a material including silicon, for example. As shown in Figure 4(a), a drive unit 31 is located on the upper surface (Z1 side) of the main body 30. The drive unit 31 is located in space S. The drive unit 31 generates a magnetic field when current is supplied by a drive circuit (not shown). The drive unit 31 is, for example, a coil. In Figure 4(a), two drive units 31 are shown, but in this embodiment, there are four drive units 31 in a plan view, surrounding the driven part 13 from all sides. That is, there is one drive unit 31 each on the front side (Y1 side) and the back side (Y2 side) of the paper in Figure 4(a). The four drive units 31 are located in space S. The main body 30 may be formed integrally with the base 21 (tilting mechanism 20).

[0030] As shown in Figures 1 and 4(a), the heat dissipation section 40 is located between the tilting section 10 and the tilting mechanism 20. The heat dissipation section 40 extends across the entire space between the tilting section 10 and the tilting mechanism 20. The heat dissipation section 40 is located to fill the space between the tilting section 10 and the tilting mechanism 20. In this embodiment, the heat dissipation section 40 is located between the tilting section 10 and the base section 21.

[0031] As shown in Figure 4(b), the heat dissipation section 40 is an aggregate formed by the twisting together of multiple fibrous materials 41. The fibrous materials 41 are, for example, carbon nanotubes. In other words, in this embodiment, the heat dissipation section 40 includes an aggregate formed by the twisting together of fibrous carbon nanotubes. The heat dissipation section 40, which is an aggregate of fibrous materials 41, is elastically deformable. When the tilting section 10 is not tilted, the heat dissipation section 40 exists in the space between the tilting section 10 and the tilting mechanism 20 in a compressed state from its normal state (no-load state). As shown in Figure 4(b), each fibrous material 41 contained in the heat dissipation section 40 is intertwined with each other, so as shown in Figure 4(a), it hardly escapes from the gap 20a provided in the tilting mechanism 20 and the gap 11f between the flat plate section 11a and the base section 21.

[0032] In this embodiment, the thermal conductivity of the heat dissipation section 40 is higher than that of the tilting section 10 and the base section 21. In this embodiment, as described above, the heat dissipation section 40 contains carbon nanotubes. The thermal conductivity of carbon nanotubes is approximately 6000 W / mK, which is higher than the thermal conductivity of silicon (approximately 162 W / mK) contained in the constituent materials of the tilting section 10 and the base section 21. Furthermore, since carbon nanotubes have a higher thermal conductivity than metals such as aluminum alloys and copper, which have good thermal conductivity, they are suitable as a material for dissipating heat by thermal conduction.

[0033] The fibrous material 41 (carbon nanotubes) contained in the heat dissipation section 40 is formed on the surface 11e of the non-tilting flat plate section 11a opposite to the reflective mirror 12 (Z2 side) by chemical vapor deposition (CVD) such as the supergrowth method. In other words, in this embodiment, the fibrous material 41 (carbon nanotubes) contained in the heat dissipation section 40 is formed by chemical vapor deposition on the surface 11e of the non-tilting tilting section 10 opposite to the reflective mirror 12 (Z2 side). As a result, the heat dissipation section 40 is in contact with the tilting section 10 by chemical bonding, but is not chemically bonded to the tilting mechanism 20, and is simply in contact with it. Each fibrous material 41 includes cases where it is a single carbon nanotube, and cases where it is an aggregated state called a bundle in which multiple carbon nanotubes are twisted together like a thread.

[0034] As shown in Figure 4(a), in this embodiment, the heat dissipation section 40 exists separately from the support section 22 and is located on the opposite side of the tilting section 10 from the reflective mirror 12 so that the tilting section 10 absorbs electromagnetic waves such as light and dissipates the heat accumulated in the tilting section 10. Furthermore, the heat dissipation section 40 is in contact with both the tilting section 10 and the base section 21 so that it dissipates the heat accumulated in the tilting section 10 by transferring it to the base section 21. The heat dissipation section 40 also transfers the heat accumulated in the tilting section 10 not only to the base section 21 but also to the arm section 23. The arm section 23 dissipates the heat transferred from the tilting section 10 to the arm section 23 by the heat dissipation section 40 by transferring it to the base section 21.

[0035] (Tilting motion of the tilting part) Next, the tilting motion of the tilting unit 10 will be described with reference to Figures 1 and 4(a) to 4(e).

[0036] When no current is supplied to the drive unit 31, as shown in Figure 4(a), no driving force is generated to tilt the tilting unit 10, and therefore the tilting unit 10 does not tilt. When a drive circuit (not shown) supplies current to the drive unit 31, as shown in Figure 4(c), the driven unit 13 moves due to the influence of the magnetic field generated by the supply of current to the drive unit 31. As the driven unit 13 moves, the tilting unit 10 tilts. As shown in Figure 4(c), the support unit 22 elastically deforms while supporting the tilting unit 10 in accordance with its tilting motion. In other words, in this embodiment, the mirror tilting device 100 is a so-called electromagnetically driven type.

[0037] As mentioned above, in a plan view, there are four drive units 31 surrounding the driven unit 13 from all sides. Therefore, the tilting unit 10 tilts in any direction by individually controlling the current supplied to the four drive units 31 by a control unit (not shown) that controls the supply of current by a drive circuit (not shown). Specifically, as shown in Figure 1, the tilting unit 10 tilts around a first tilting center axis L1 and a second tilting center axis L2, which pass through the center 10a of the tilting unit 10 in the non-tilting state and are perpendicular to the thickness direction (Z direction) of the tilting unit 10 in the non-tilting state. The first tilting center axis L1 and the second tilting center axis L2 are perpendicular to each other. Figure 4(c) shows the state in which the tilting unit 10 is tilting around the second tilting center axis L2.

[0038] As shown in Figure 4(c), in this embodiment, the heat dissipation section 40 elastically deforms its external shape in accordance with the shape of the space between the tilting section 10 and the base section 21, which changes as the tilting section 10 tilts. Also, as shown in Figure 4(c), the first heat dissipation section 40a (heat dissipation section 40), which is located in a region where the space between the tilting section 10 and the base section 21 becomes smaller as the tilting section 10 tilts, elastically deforms to be compressed in accordance with the shape of the space between the tilting section 10 and the base section 21. Furthermore, the second heat dissipation section 40b (heat dissipation section 40), which is located in a region where the space between the tilting section 10 and the base section 21 becomes larger as the tilting section 10 tilts, elastically deforms to expand in accordance with the shape of the space between the tilting section 10 and the base section 21. Furthermore, the first heat dissipation section 40a and the second heat dissipation section 40b remain in contact with both the tilting section 10 and the base section 21 (tilting mechanism 20) from the state in which the tilting section 10 is not tilted to the state in which the tilting section 10 is tilted.

[0039] In this embodiment, as shown in Figures 4(b), 4(d), and 4(e), the external shape of the heat dissipation section 40 changes in such a way that its bulk density changes according to the shape of the space between the tilting section 10 and the base section 21, which changes as the tilting section 10 tilts. Specifically, the bulk density of the first heat dissipation section 40a, where the space between the tilting section 10 and the base section 21 is reduced due to the tilting of the tilting section 10 as shown in Figure 4(d), is greater than the bulk density of the heat dissipation section 40 when the tilting section 10 is not tilted, as shown in Figure 4(b). Also, the bulk density of the second heat dissipation section 40b, where the space between the tilting section 10 and the base section 21 is increased due to the tilting of the tilting section 10 as shown in Figure 4(e), is smaller than the bulk density of the heat dissipation section 40 when the tilting section 10 is not tilted, as shown in Figure 4(b).

[0040] Furthermore, since carbon nanotubes have a relatively large fracture strain, the carbon nanotubes (heat dissipation section 40) will not fracture even if the tilting section 10 undergoes repeated elastic deformation due to repeated tilting.

[0041] (Effects of this embodiment) Next, the effects of this embodiment will be described.

[0042] In this embodiment, as described above, the elastically deformable heat dissipation section 40 exists separately from the support section 22, allowing heat accumulated in the tilting section 10 to be dissipated without restricting the tilting motion of the tilting section 10.

[0043] Furthermore, in this embodiment, as described above, the heat dissipation unit 40 is further provided with a base portion 21 that is separated from the tilting portion 10 by a distance D and has a larger volume than the tilting portion 10, and the heat dissipation unit 40 is in contact with both the tilting portion 10 and the base portion 21 in order to dissipate the heat accumulated in the tilting portion 10 by transferring it to the base portion 21. As a result, the heat dissipation unit 40 can effectively dissipate the heat accumulated in the tilting portion 10 by transferring the heat accumulated in the tilting portion 10 to the base portion 21 which has a larger volume than the tilting portion 10. In addition, even in cases where heat dissipation into the atmosphere is almost impossible, such as in a vacuum, the heat accumulated in the tilting portion 10 can be easily dissipated.

[0044] Furthermore, in this embodiment, as described above, the heat dissipation section 40 is located between the tilting section 10 and the base section 21. Compared to the case where the heat dissipation section 40 is located not between the tilting section 10 and the base section 21, but rather bypasses the space between the tilting section 10 and the base section 21, the distance over which heat is conducted from the tilting section 10 to the base section 21 via the heat dissipation section 40 is reduced, allowing the heat accumulated in the tilting section 10 to be dissipated more efficiently by the heat dissipation section 40.

[0045] Furthermore, in this embodiment, as described above, the heat dissipation section 40 elastically deforms its external shape in accordance with the shape of the space between the tilting section 10 and the base section 21, which changes as the tilting section 10 tilts. This ensures that the heat dissipation section 40 is always in contact with both the tilting section 10 and the base section 21 when the tilting section 10 tilts. This prevents a decrease in the heat dissipation efficiency of the heat dissipation section 40 or an imbalance in heat dissipation occurring in each part of the tilting section 10, which would otherwise result from the heat dissipation section 40 separating from at least one of the tilting section 10 and the base section 21. In addition, even if the space between the tilting section 10 and the base section 21 narrows due to the tilting of the tilting section 10, the heat dissipation section 40 does not hinder the tilting of the tilting section 10.

[0046] Furthermore, in this embodiment, as described above, the external shape of the heat dissipation section 40 changes in accordance with the shape of the space between the tilting section 10 and the base section 21, which changes as the tilting section 10 tilts, so that the bulk density changes. As a result, even if the space between the tilting section 10 and the base section 21 widens or narrows as the tilting section 10 tilts, the external shape of the heat dissipation section 40 can be changed so that a constant weight of the heat dissipation section 40 is always present in the space between the tilting section 10 and the base section 21.

[0047] Furthermore, in this embodiment, as described above, the thermal conductivity of the heat dissipation section 40 is higher than that of the tilting section 10 and the base section 21. As a result, the heat dissipation section 40, which has a relatively high thermal conductivity, can more effectively transfer the heat accumulated in the tilting section 10 to the base section 21.

[0048] Furthermore, in this embodiment, as described above, the heat dissipation section 40 includes carbon nanotubes. By including carbon nanotubes, which have a higher thermal conductivity than metals such as aluminum and copper that have good thermal conductivity, the heat accumulated in the tilting section 10 can be effectively dissipated by transferring it to the atmosphere or other structures.

[0049] Furthermore, in this embodiment, as described above, the heat dissipation section 40 includes an aggregate of twisted fibrous carbon nanotubes. This allows the external shape of the heat dissipation section 40 to be easily elastically deformed in response to changes in the shape of the space where the heat dissipation section 40 is provided, without restricting the tilting motion of the tilting section 10.

[0050] Furthermore, in this embodiment, as described above, the carbon nanotubes are formed on the surface 11e of the tilting section 10 opposite to the reflective mirror 12 by chemical vapor deposition. As a result, the heat dissipation section 40 is chemically bonded to the tilting section 10, so that a decrease in the heat dissipation efficiency of the heat dissipation section 40 caused by the separation of the heat dissipation section 40 and the tilting section 10 can be reliably suppressed.

[0051] Furthermore, in this embodiment, as described above, one end of the support portion 22 is connected to the tilting portion 10 and the other end is connected to the base portion 21. This eliminates the need to provide a new structure for connecting the support portion 22 to the opposite side of the tilting portion 10, thereby suppressing an increase in the number of parts of the mirror tilting device 100 and preventing the structure of the mirror tilting device 100 from becoming more complex.

[0052] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0053] In the above embodiment, an example was shown in which the driving method of the tilting part 10 is electromagnetically driven, but the present invention is not limited thereto. For example, as in the mirror tilting device 200 of the first modified example shown in Figure 5, the driving method of the tilting part 10 may be piezoelectrically driven. The mirror tilting device 200 is equipped with a piezoelectric element 201 on the upper side (Z1 side) of the arm part 23. The tilting part 10 tilts as the piezoelectric element 201 deforms. The piezoelectric element 201 contains, for example, PZT (lead zirconate titanate) and deforms when a voltage is applied. The heat dissipation part 240 is located on the opposite side of the reflective mirror 12 of the tilting part 10, similar to the heat dissipation part 40 in the above embodiment. Although not shown, the driving method of the tilting part 10 may also be electrostatically driven.

[0054] Furthermore, although the above embodiment shows an example in which the mirror tilting device 100 is used in a vacuum, the present invention is not limited thereto. For example, the mirror tilting device 100 may be used in the atmosphere or in various gas atmospheres. In that case, the heat accumulated in the tilting part 10 is not only transferred to the base part 21 via the heat dissipation part 40, but is also dissipated by releasing the heat into the atmosphere via the heat dissipation part 40. In this way, even when the heat accumulated in the tilting part 10 is released into the atmosphere, the heat dissipation part 40 is effective in dissipating the heat accumulated in the tilting part 10 because it contains an aggregate of twisted fibrous material 41, which allows it to efficiently dissipate heat due to its relatively large surface area.

[0055] Furthermore, although the above embodiment shows an example where the heat dissipation section 40 is located between the tilting section 10 and the base section 21, the present invention is not limited to this. For example, the heat dissipation section 40 may not be located between the tilting section 10 and the base section 21, but may be located so as to bypass the space between the tilting section 10 and the base section 21.

[0056] Furthermore, in the above embodiment, an example was shown in which the thermal conductivity of the heat dissipation section 40 is higher than that of the tilting section 10 and the base section 21, but the present invention is not limited to this. For example, the thermal conductivity of the heat dissipation section 40 may be less than or equal to that of the tilting section 10 and the base section 21.

[0057] Furthermore, although the above embodiment shows an example in which the heat dissipation section 40 is an aggregate formed by twisting together a plurality of fibrous materials 41, the present invention is not limited to this. For example, the heat dissipation section 40 may have any structure as long as it is elastically deformable. For example, the heat dissipation section 40 may have a sponge-like structure with a plurality of voids inside.

[0058] Furthermore, although the above embodiment shows an example where the fibrous material 41 is a carbon nanotube, the present invention is not limited thereto. For example, the fibrous material 41 may be a metal material such as aluminum and copper processed into fibers, or a resin material such as a high thermal conductivity resin. In addition, an insulating film to prevent electrical short circuits may be provided on the surface of the parts that the heat dissipation section 40 contacts (such as the tilting section 10, the base section 21, and the support section 22). The fibrous material 41 may also be a boron nitride nanotube (BNNT). Since boron nitride nanotubes have insulating properties, if the fibrous material 41 is a boron nitride nanotube, it is not necessary to provide an insulating film to prevent electrical short circuits as described above.

[0059] Furthermore, in the above embodiment, an example was shown in which the fibrous material 41 (carbon nanotube) is formed on the surface 11e opposite to the reflective mirror 12 (Z2 side) of the tilting part 10 in the non-tilting state by chemical vapor deposition, but the present invention is not limited thereto. For example, the fibrous material 41 (carbon nanotube) formed by any other method may be inserted between the tilting part 10 and the base part 21. Alternatively, the fibrous material 41 (carbon nanotube) may be formed on the upper surface (Z1 side) of the tilting mechanism 20 by chemical vapor deposition so as to extend toward the tilting part 10. However, because the heat dissipation part 40 tends to separate from the tilting part 10 more easily than from the tilting mechanism 20 due to the influence of its own weight, it is preferable to form the fibrous material 41 (carbon nanotube) on the surface 11e opposite to the reflective mirror 12 (Z2 side) of the tilting part 10 in the non-tilting state by chemical vapor deposition.

[0060] Furthermore, in the above embodiment, an example was shown in which the support portion 22 is connected at one end to the tilting portion 10 and at the other end to the base portion 21, but the present invention is not limited to this. For example, as in the second modified mirror tilting device 300 shown in Figure 6, the support portion 322 may be connected at one end to the tilting portion 10 (flat plate portion 311) and at the other end to a separately provided fixing portion 320. The fixing portion 320 supports (fixes) the support portion 322 so that it does not move. In this case, the base portion 321 exists so as to overlap the entire tilting portion 310 when viewed from the thickness direction (Z direction) of the tilting portion 310 in the non-tilting state, and the heat dissipation portion 340 exists throughout the entire space between the tilting portion 310 and the base portion 321.

[0061] Furthermore, in the above embodiment, an example was shown in which the tilting part 10 is tilted by a moving magnet system in which a coil is applied as the drive unit 31 and a permanent magnet is applied as the driven unit 13, but the present invention is not limited thereto. For example, the tilting part 10 may be tilted by a moving coil system in which an electromagnet is applied as the drive unit 31 and a coil is applied as the driven unit 13.

[0062] Furthermore, although the above embodiment shows an example where the heat dissipation section 40 is present throughout the entire space between the tilting section 10 and the tilting mechanism 20, the present invention is not limited to this. For example, the heat dissipation section 40 may be present only in a part of the space between the tilting section 10 and the tilting mechanism 20. [Explanation of symbols]

[0063] 10, 310 Tilt part 11e side 12 Reflective mirrors 21, 321 Base 22, 322 Support part 40, 240, 340 Heat dissipation section 41. Fibrous material (carbon nanotube) 100, 200, 300 Mirror tilting device D Interval (predetermined interval)

Claims

1. A reflective mirror that reflects electromagnetic waves is provided, and a tilting part is configured to be tiltable, A support portion that supports the tilting portion, A mirror tilting device comprising: an elastically deformable heat dissipation section provided separately from the support section and on the opposite side of the tilting section from the reflective mirror, such that the tilting section absorbs electromagnetic waves and dissipates the heat accumulated in the tilting section.

2. The tilting portion is provided at a predetermined distance from the tilting portion, and further comprises a base portion having a volume larger than the volume of the tilting portion. The mirror tilting device according to claim 1, wherein the heat dissipation section is provided so as to be in contact with both the tilting section and the base section in order to dissipate heat by transferring the heat accumulated in the tilting section to the base section.

3. The mirror tilting device according to claim 2, wherein the heat dissipation section is provided between the tilting section and the base section.

4. The mirror tilting device according to claim 3, wherein the heat dissipation section elastically deforms its external shape according to the shape of the space between the tilting section and the base section, which changes as the tilting section tilts.

5. The mirror tilting device according to claim 4, wherein the heat dissipation section changes its external shape so as to change in accordance with the shape of the space between the tilting section and the base section, which changes as the tilting section tilts.

6. The mirror tilting device according to claim 2, wherein the thermal conductivity of the heat dissipation section is higher than the thermal conductivity of the tilting section and the thermal conductivity of the base section.

7. The mirror tilting device according to claim 1, wherein the heat dissipation section includes carbon nanotubes or boron nitride nanotubes.

8. The mirror tilting device according to claim 7, wherein the heat dissipation section includes an aggregate of fibrous carbon nanotubes or boron nitride nanotubes twisted together.

9. The mirror tilting device according to claim 7, wherein the carbon nanotubes are formed on the surface of the tilting portion opposite to the reflective mirror by chemical vapor deposition.

10. The mirror tilting device according to claim 2, wherein one end of the support portion is connected to the tilting portion and the other end is connected to the base portion.

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