Article and optical device

Abstract

To minimize the reduction in water repellency.SOLUTION: An article is provided, comprising portions facing each other with a gap therebetween, where the gap has a width that causes capillary effect and at least one of the opposing portions is provided with a rugged structure having a lotus effect.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an article and an optical instrument. [Background technology]

[0002] Many commonly used products are made up of multiple parts, which are fixed to each other by screws or adhesives. However, in the case of moving parts, gaps are often provided between adjacent parts to allow for smooth operation, and even in cases where the parts are not moving, gaps can form between each other.

[0003] If water droplets get into these gaps, it can have a detrimental effect on the product. To address this issue, packing materials such as rubber or sponge are sometimes provided in the gaps. Patent Document 1 also discloses a form in which water seepage is reduced by using a water-repellent oil barrier. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 5-64811 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a water-repellent substance is applied to the gap, there is a risk that the water-repellent property will decrease as the member is continuously used due to the water-repellent substance peeling off.

[0006] Therefore, an object of the present invention is to suppress the decrease in water repellency. [Means for solving the problem]

[0007] A first means for solving the above problem is an article having opposing parts separated by a gap, the width of the gap being a width that exhibits capillary action, and at least one of the opposing parts is provided with a concave-convex structure having a lotus effect.

[0008] A second means for solving the above problem is an article having parts facing each other with a gap therebetween, wherein at least one of the facing parts has a concave-convex structure, the pitch of the convex parts of the concave-convex structure or the pitch of the concave-convex structure is 70 μm or less, the height of the convex parts or the depth of the concave parts is 1 μm or more, the width of the convex parts or the width of the concave parts is 100 μm or less, and the width of the gap is 0.05 mm or more and 2 mm or less.

[0009] A third means for solving the above problem is an article comprising a first part and a second part opposing the first part, with a gap provided between the first part and the second part, wherein an uneven structure is provided on a surface of the first part opposing the second part, the pitch of the convex portions of the uneven structure or the pitch of the concave portions of the uneven structure is 70 μm or less, the height of the convex portions or the depth of the concave portions is 1 μm or more, the width of the convex portions or the width of the concave portions is 100 μm or less, and the width of the gap is 0.05 mm or more and 2 mm or less.

[0010] A fourth means for solving the above problem is an article comprising a first part and a second part facing the first part, with a gap between the first part and the second part, wherein the width of the gap is a width that exhibits capillary action, and the article is characterized in that a concave-convex structure having a lotus effect is provided on the surface of the first part facing the second part. Effect of the Invention

[0011] To provide a technology that is advantageous in suppressing a decrease in water repellency. [Brief description of the drawings]

[0012] [Figure 1] 1A is a diagram showing a state in which the components are close to each other, and FIG. 1B is a diagram showing a state in which the components are separated from each other. [Diagram 2] FIG. 1(b) is an enlarged view of the area surrounded by circle A in FIG. [Diagram 3] FIG. 4 is a perspective view showing the shape of a protrusion. [Figure 4] FIG. 2 is a diagram showing an arrangement pattern of a concave-convex structure. [Diagram 5] FIG. 1 is a schematic diagram showing water entering a gap. [Figure 6] 1A to 1C are diagrams showing various concave-convex structures. [Figure 7] 1 is a graph showing the relationship between the contact angle and the arrangement pitch. [Figure 8] FIG. [Figure 9] 1A to 1C are diagrams illustrating a method for manufacturing a mold. [Figure 10] FIG. 2 is a diagram showing the surface of a mold during processing. [Figure 11] (a) is a photograph used as a substitute for a drawing, showing the surface of a mold after laser processing, observed with an electron microscope, and (b) is a photograph used as a substitute for a drawing, showing the surface of a resin molded product, observed with an electron microscope. [Figure 12] FIG. 1 is a diagram showing the injection molding process. [Figure 13] 1 is a diagram of an imaging device to which the present invention can be applied; [Figure 14] FIG. 14 is a cross-sectional view of the lens barrel of FIG. 13. [Figure 15] FIG. 15 is an enlarged view of the area surrounded by circle B in FIG. 14. [Figure 16] FIG. 2 is a diagram showing the uneven structure of the first embodiment applied to a container. [Figure 17] FIG. 4 is a schematic diagram of an article according to a second embodiment. [Figure 18] 1 is a schematic diagram of a large water droplet colliding with an object. [Figure 19] 1 is a schematic diagram showing a state where a small water droplet collides with an object. [Figure 20] FIG. 2 is a diagram of the concave-convex structure of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiment for carrying out the present invention will be described with reference to the drawings. However, the embodiment described below is one embodiment of the invention, and the present invention is not limited to this. Then, common configurations will be described with mutual reference to multiple drawings, and the description of configurations with common symbols will be omitted as appropriate. Items with the same name but different can be distinguished by adding "No. 0", such as the first item and the second item.

[0014] First Embodiment An article 100 according to this embodiment will be described with reference to FIGS. 1 and 2. The article 100 is composed of a part 1 and a part 2, and a gap 3 is provided between the parts 1 and 2. At least the gap 3 needs to be provided between the parts 1 and 2, and the parts 1 and 2 may be in contact with each other and fixed at a portion other than the gap 3. FIG. 1(a) is a diagram showing a state in which the parts 1 and 2 are close to each other, and FIG. 1(b) is a diagram showing a state in which the parts 1 and 2 are separated from each other. The material of the parts 1 and 2 is preferably resin, but various materials such as metal and ceramic can be used. In this embodiment, the parts 1 and 2 are each formed of polycarbonate. The part 1 has a surface 7, a surface 8, and a surface 9 from the surface 110 side, and the parts 1 and 2 are close to each other so as to face the surfaces 4, 5, and 6 of the part 2, respectively. For example, at least one of the parts 1 and 2 may be a movable member, and may be configured to slide against each other.

[0015] FIG. 2 is an enlarged view of the area surrounded by a circle A in FIG. 1(a). In FIG. 2, the uneven structure 10 is provided on the surfaces 4 to 9. However, the uneven structure 10 may be provided only on the surfaces 4 and 7, or may be provided only on the surfaces 6 and 9, and it is sufficient that the uneven structure 10 is provided on at least one of the opposing surfaces. When the uneven structure 10 is provided on both opposing surfaces, it is preferable that the uneven structure 10 is the same uneven structure. As shown in FIG. 2, the gap 3 is preferably a bent structure in order to suppress the intrusion of water droplets, and it is preferable that the surfaces 4 and 5, and the surfaces 7 and 8 are non-parallel to each other. In addition, as shown in FIG. 2, if the cross section of the gap 3 is crank-shaped, it is more preferable because the effect of suppressing the intrusion of water droplets is enhanced.

[0016] Next, the shape of the convex portions 101 of the uneven surface structure 10 will be described with reference to Fig. 3. The convex portions 101 are provided on the base surface 11, and may have any shape such as a cylindrical shape as shown in Fig. 3(a), a conical shape as shown in Fig. 3(b), or a truncated conical shape as shown in Fig. 3(c), as long as they have a water-repellent function. Instead of providing the convex portions 101 protruding from the base surface 11, the uneven surface structure 10 may have a plurality of concave portions recessed from the base surface 11.

[0017] The convex portion 101 will be described in detail in FIG. 4. FIG. 4 shows a part of the arrangement as viewed from the normal direction of the base surface 11 to which the concave-convex structure 10 is applied (see FIG. 3). FIG. 4(a) shows a pattern in which the convex portions 101 are arranged in a lattice shape, and FIG. 4(b) shows a pattern in which the convex portions 101 are arranged in a honeycomb shape. The arrangement of the convex portions 101 in the concave-convex structure 10 may be random, but it is preferable that they are arranged in a uniform periodic pattern as shown in FIG. 4(a) and (b). Furthermore, in order to arrange the convex portions 101 more densely, the honeycomb arrangement of FIG. 4(b) is more preferable. In FIG. 4, a configuration having a flat surface (base surface 11 shown in FIG. 3) between adjacent convex portions 101 has been described. However, when the convex portions 101 are conical or truncated conical as shown in FIG. 3(b) or (c), the inclined surfaces of the convex portions 101 may be arranged adjacent to each other with a linear boundary (valley) between them. In this case, the base surface 11 shown in Fig. 3 becomes a virtual surface including continuous valleys within the surface. Regarding the arrangement described above, various arrangements can be applied in the same manner when the uneven structure 10 having a plurality of recesses recessed from the base surface 11 is adopted.

[0018] Next, the effect of the concave-convex structure 10 in suppressing the infiltration of water into the gap 3 will be described. First, with reference to FIG. 5(a), the infiltration state of water when water is dropped into the gap 3 without the concave-convex structure 10 will be described. When water 12 is dropped into the gap 3, the contact angle θ caused by the surface tension of the water 12 is often smaller than 90° in the case of a part made of a general resin. Therefore, a force 13 caused by the capillary phenomenon occurring in the gap 3 occurs in a direction that causes the water 12 to infiltrate (downward in FIG. 5(a)), allowing the water 12 to infiltrate.

[0019] Next, the effect of the article 100 of this embodiment in suppressing the intrusion of water into the gap 3 by the uneven structure 10 will be described with reference to FIG. 5(b). When water 12 is dropped into the gap 3, the uneven structure 10 reduces the contact area between the water 12 and the parts 1 and 2. As shown in FIG. 5(b), in the case of the article 100 made of polycarbonate of this embodiment, the contact area is reduced and the contact angle θ becomes larger than 90°. When the contact angle becomes larger than 90°, the force 13 generated in the gap 3 occurs in a direction that suppresses the intrusion of the water 12 (upward in FIG. 5(b)), so that the water 12 can be suppressed from intruding into the gap 3 without using an article such as a packing.

[0020] In addition, the uneven structure 10 is less likely to deteriorate over time compared to when a water repellent such as a lubricating oil is used, so that the deterioration of the water repellent function can be suppressed. The effect of adjusting the surface free energy of a part by using an uneven structure to generate a water repellent function is called the lotus effect. The width D of the gap 3 that requires a water repellent function is a width that generates a capillary phenomenon, and is 0.05 mm or more and 2 mm or less. However, when the width of the gap 3 is 0.1 mm or more and 1 mm or less, the configuration of this embodiment is more suitable for use. Here, the width D is the distance between the base surface 11 and the surface facing the base surface 11. However, the width D of the gap 3 is not particularly limited, and the configuration of this embodiment can be used as long as it is a width that generates a capillary phenomenon.

[0021] Next, the shape of the concave-convex structure 10 will be described with reference to Figures 6 to 8. As shown in Figure 6(a), a good water-repellent state can be achieved by increasing the apparent contact angle θ generated by the surface tension of water when the concave-convex structure 10 and air support water 12. First, the arrangement pitch of the concave-convex structure 10 will be described with reference to Figure 6(b).

[0022] If the arrangement pitch is excessively large, the uneven structure 10 cannot support the water 12 and comes into contact with the base surface, so the contact angle θ becomes small and it is not possible to achieve a water-repellent state. FIG. 7 is a graph obtained by experimenting the relationship between the arrangement pitch P of the convex portions 101 and the contact angle θ in the uneven structure 10 in which the convex portions 101 with a width R of 40 μm and a height H of 30 μm are formed on the surface of a part made of polycarbonate resin as shown in FIG. 8. Measurements were performed for two types of arrangement: a honeycomb arrangement and a lattice arrangement. It can be seen that the contact angle θ becomes smaller as the arrangement pitch P becomes larger, and that the contact angle does not change from a flat surface when the arrangement pitch P exceeds 90 μm. In FIG. 7, for convenience, the contact angle in the case of a flat surface without the convex portions 101 is shown at the point where the arrangement pitch P is 0.

[0023] The arrangement pitch P of the concave-convex structure 10 is preferably 10 μm to 80 μm, more preferably 70 μm or less. If it is 70 μm or less, the contact angle θ can be made 100° or more, as shown in FIG. 7. Here, the arrangement pitch P is the distance between the center of a certain convex portion and the center of a convex portion adjacent to a certain convex portion. The pitch in the concave portion can be defined in the same way as the convex portion.

[0024] In order to obtain the effect of suppressing the intrusion of water into the gaps 3 in the article 100 of this embodiment, the contact angle θ is preferably 90° or more, and more preferably 100° or more. However, the shape of the uneven structure 10 is not particularly limited, and it is sufficient if the uneven structure 10 has a lotus effect.

[0025] Next, the lattice arrangement and the honeycomb arrangement are compared. In FIG. 7, when the data is focused on when the contact angle θ is 120° and the pitch P is about 50 μm, it can be seen that the honeycomb arrangement tends to maintain a larger contact angle even with a larger pitch P. As shown in FIG. 4(a), it can be seen that the interval of the uneven structure 10 in the lattice arrangement is large in the diagonal direction. From this, in the case of the lattice arrangement, due to the large pitch in the diagonal direction, water contacts the base surface as shown in FIG. 6(b), the contact angle becomes small, and the water repellency effect is smaller than that of the honeycomb arrangement. On the other hand, as shown in FIG. 4(b), it can be seen that the interval of the uneven structure 10 in the honeycomb arrangement is constant at any location. In the case of the honeycomb arrangement, the water repellency effect is larger than that of the lattice arrangement, so the arrangement pattern is preferably a honeycomb arrangement. However, in addition to the lattice arrangement and the honeycomb arrangement, it is also possible to arrange the uneven structure 10 randomly.

[0026] Next, the height H of the convex portion 101 of the concave-convex structure 10 will be described with reference to FIG. 6. When the height H of the convex portion 101 is sufficiently large as shown in FIG. 6(a), the air between the convex portions 101 can support water, so that the apparent contact angle generated by the surface tension of water can be increased. On the other hand, when the height H of the convex portion 101 is small as shown in FIG. 6(c), the water comes into contact with the base surface, so that the contact angle becomes small and it is difficult to make the surface water-repellent. In order to make the surface water-repellent, the height H of the convex portion 101 is preferably 1 μm or more, and more preferably 10 μm or more. The upper limit value of the height H is preferably smaller than half the width D of the gap. For example, the height H is preferably 150 μm or less, and more preferably 100 μm or less. If a concave portion is provided on the base surface 11, the depth of the concave portion is the depth from the base surface 11, and is preferably in the same range as the height of the convex portion.

[0027] Next, the width R of the convex portion 101 of the concave-convex structure 10 will be described with reference to FIG. 6. As shown in FIG. 6(d), when the width R of the convex portion 101 is large, the surface area of ​​the convex portion 101 increases. Therefore, the ratio of air supporting water decreases, and the apparent contact angle generated by surface tension decreases. To achieve a water-repellent state, the width R of the convex portion 101 is preferably 100 μm or less, and more preferably 60 μm or less. The width R of the convex portion 101 is preferably 10 μm or more, and more preferably 30 μm or more. The width of the concave portion is also preferably in the same range as the convex portion 101. The width R in FIG. 3(b) and FIG. 3(c) is the width of the largest part of a certain convex portion, and the width of the concave portion is similarly the width of the largest part of a certain concave portion.

[0028] Next, a manufacturing method for manufacturing the article 100 of this embodiment will be described. Here, a method using injection molding with a mold will be described, but the method is not limited to injection molding. First, a manufacturing method for the mold 16 will be described. The manufacturing method for the mold 16 includes a method of manufacturing a molded product having a concave-convex structure by transferring depressions formed by cutting processing to resin, and a method of manufacturing a molded product having a concave-convex structure by transferring depressions formed by laser processing to resin. In this embodiment, a method of manufacturing a molded product by transferring depressions formed by laser processing to resin will be described.

[0029] FIG. 9 shows an example of the configuration of a laser processing machine as a device for processing a mold 16. In this example, the laser processing machine 14 is configured so that the laser head 15 can move in three axes, namely, the linear axis X, the linear axis Y, and the linear axis Z. In addition, a galvanometer mirror (not shown) is built into the laser head 15. Some laser processing machines are configured so that the laser head 15 can move in more directions, and such laser processing machines may be used. The laser head 15 is moved by a driving means (not shown) according to the movement amount of each axis described in the NC data 17. Meanwhile, the laser head 15 emits a laser beam according to the NC data 17, and scans the laser beam on the mold 16 using the galvanometer mirror. In this way, the laser head 15 can process an arbitrary shape on the mold 16.

[0030] FIG. 10 is an enlarged view of the processing performed on the surface of a mold 16 by a laser processing machine. The figure shows the surface of the mold 16 as seen from the cross-sectional direction. The mold 16 can have various shapes, such as a flat surface or a complex curved surface, depending on the shape of the molded product. Therefore, the base surface as seen from the cross-sectional direction is not necessarily a straight line, but FIG. 10 shows a straight line as an example. A laser beam 18 is emitted from a laser head 15 to form a processing hole 19 with each pulse. For example, infrared light with a wavelength of 1064 nm and a femtosecond pulse width can be used as the laser beam, but other lasers may also be used.

[0031] As shown in Figure 10, the laser light is repeatedly moved by a galvanometer mirror by the pitch P of the uneven structure, while the laser light is irradiated onto the die 16 to form multiple machined holes 19. Figure 11(a) is a photograph of the surface of the die 16 after laser processing, observed with an electron microscope. It can be seen that the arrangement pattern of the machined holes 19 is formed in a honeycomb arrangement. Through these steps, a molding die 16 can be obtained.

[0032] Next, the injection molding process will be described. FIG. 12 is a schematic diagram showing the injection molding process for manufacturing the article 100 of this embodiment. A general injection molding machine can be used as the injection molding machine. Resin is injected into the space formed by the mold 16 and the mold 20 shown in FIG. 12(a) by a cylindrical cylinder 21. Meanwhile, a hopper 22 puts the resin material into the inside of the cylinder 21. Thermoplastic materials such as polystyrene, polycarbonate, and polypropylene can be used as the resin material. The resin material may be colored by mixing a coloring agent such as a pigment in advance. Inside the cylinder 21, there is a screw (not shown), which is rotated by a motor (not shown) to send the resin material inside the hopper 22 to the tip of the cylinder 21. In addition, the cylinder 21 is equipped with a heater (not shown), and the resin material put in from the hopper 22 is heated to a temperature above the glass transition temperature of the resin material in the process of being sent to the tip inside the cylinder, and is melted into a liquid state. Then, it is stored in the space at the tip of the cylinder 21.

[0033] 12(b) is called a mold clamping process, in which the molds 16 and 20 are aligned by a mechanism (not shown). The molds 16 and 20 are heated by a heater (not shown). The heating temperature of the molds in this process is called the mold temperature.

[0034] 12(c) is called the injection process, in which the cylinder 21 is pressed against the injection hole provided in the mold 20. Furthermore, the hydraulic cylinder unit 23 operates to push a screw (not shown) toward the tip of the cylinder 21, thereby injecting molten resin 24 into the space inside the joined molds 16, 20. The temperature of the molten resin 24 in this process is called the resin temperature.

[0035] FIG. 12(d) shows steps called the dwelling step and the cooling step. In the dwelling step, the pressure inside the cylinder 21 is controlled to maintain the pressure of the molten resin 24 inside the molds 16, 20 at a desired pressure. This pressure is called dwelling. A dwelling pressure is selected such that the resin 24 permeates every corner of the space inside the molds 16, 20. In the cooling step following the dwelling step, the molds 16, 20 in FIG. 12(d) are cooled by a cooling mechanism (not shown). This cools the resin 24 inside the molds 16, 20 to a temperature below the glass transition temperature, forming a resin molded product 240. The cooling mechanism may, for example, be a means for circulating cooling water around the mold 16.

[0036] Next, FIG. 12(e) shows a process called a mold opening process and a mold releasing process. The molds 16 and 20 are opened by a mechanism not shown. Then, the resin molded product 24 is removed from the molds 16 and 20 by a mold releasing mechanism not shown. Generally, at the stage when the molds 16 and 20 are opened, the resin molded product 240 is stuck to the surface of the molds 16 and 20. The mold releasing mechanism performs an operation of pushing out the resin molded product 240 stuck to the mold surface from the molds 16 and 20 by a rod called an ejector pin that penetrates the mold. FIG. 11(b) is a drawing substitute photograph of the surface of the removed resin molded product 240 observed with an electron microscope. In FIG. 11(b), it can be confirmed that a honeycomb-arranged fine shape transferred from the mold shape in FIG. 11(a) is formed on the resin molded product 240. Through such a process, the resin molded product 240 can be obtained.

[0037] Next, a description will be given of a case where the concave-convex structure 10 of this embodiment is applied to an imaging device 200. However, this embodiment is not limited to application to the imaging device 200, and can be applied to various molded products such as printers and speakers.

[0038] 13 is a schematic diagram of a digital camera, which is an example of an imaging device 200 to which this embodiment can be applied. The imaging device 200 comprises a main body 25 and a lens barrel 26 that is detachable from the main body 25. The lens barrel 26 is made up of multiple parts, which are integrated together by methods such as screwing, gluing, and fitting. Furthermore, there are often seams and gaps between the parts on the surface of the lens barrel 26. Therefore, a case in which this embodiment is applied to the lens barrel 26 will be described.

[0039] Fig. 14 is a cross-sectional view of lens barrel 26 in Fig. 13. Lens barrel 26 is an optical device having lens 33, and lens mount 27 holds lens barrel 26 detachably to main body 25. Fixed barrel 28 holds an operation member (operation ring) of lens barrel 26. Lens mount 27 is held integrally to fixed barrel 28 using screws or the like. Exterior ring 29 is an exterior component of lens barrel 26, and also covers and protects the internal mechanism of lens barrel 26. Exterior ring 29 is held integrally to operation ring 32 and fixed barrel 28 using screws or the like.

[0040] A knurled groove (uneven portion) (not shown) is formed on the outer periphery of the operation ring 32 so that the user can easily rotate the operation ring 32. The operation ring 31 has an engagement portion 31a which fits into an engagement portion of the fixed barrel 28. The front ring 30 is fixed to the fixed barrel 28 by adhesive or the like.

[0041] Fig. 15 is an enlarged view of the area surrounded by circle B in Fig. 14, and a gap 3 is provided between operation ring 31 and operation ring 32. An uneven structure 10 is formed on the operation ring 32 side of operation ring 31 and on the operation ring 31 side of operation ring 32. As shown in Fig. 15, by providing uneven structure 10 on lens barrel 26, it is possible to prevent water from entering the inside of imaging device 200.

[0042] 16, a case where the uneven structure 10 of this embodiment is applied to a container 40 will be described. The container 40 has a main body 41 and a lid 42, and the main body 41 and the lid 42 are connected by a hinge 43 so that opening and closing can be easily performed.

[0043] Fig. 16(b) is an enlarged view of the area surrounded by circle C when the lid 42 of the container 40 in Fig. 16(a) is closed. The container 40 has a gap 3 between the main body 41 and the lid 42. Meanwhile, an uneven structure 10 is provided on the lid 42 side of the main body 41 and on the main body 41 side of the lid 42. This makes it possible to prevent water from entering the inside of the container 40 when the lid 42 is closed. The container 40 is suitable as a storage container for products that should preferably be avoided from coming into contact with moisture, such as cosmetics, medicines, and paper.

[0044] A water repellent agent or the like can also be applied to the surface having the uneven structure 10, thereby providing an article 100 with a higher water repellent effect.

[0045] <Second embodiment> An article 100 according to the second embodiment will be described with reference to Figures 17, 18, and 19. Figure 17 is a schematic diagram of the article 100 according to this embodiment, Figure 18 is a schematic diagram of the article 100 when a large water droplet 12A collides with the article 100, and Figure 19 is a schematic diagram of the article 100 when a small water droplet 12A collides with the article 100.

[0046] The article 100 of this embodiment differs from the article 100 of the first embodiment in that the uneven structure 10 is not provided on the surfaces 4, 6, 7, and 9, and the uneven structure 10 is provided on the surfaces 5 and 8 that are non-parallel to the surfaces 4, 6, 7, and 9. Here, the surfaces not provided with the uneven structure 10 only need to be flatter than the surfaces provided with the uneven structure 10, and do not need to be completely flat. The surfaces 7 and 9 are, for example, the first part of the part 1, and the surface 8 is, for example, the second part. Meanwhile, the surfaces 4 and 6 are, for example, the first part of the part 2, and the surface 5 is, for example, the second part of the part 2.

[0047] Advantages of the article 100 of this embodiment will be described with reference to FIG. 18 and FIG. 19. The water droplet 12A in FIG. 18 is a water droplet before colliding with the article 100, and the water droplet 12B is a water droplet after colliding with the article 100. The water droplet 12A has kinetic energy in the direction of the arrow 35, and collide with the article 100 while having kinetic energy. Even if the uneven structure 10 is provided on the surface 4 or the surface 7, it cannot withstand the kinetic energy, and water repellency is difficult. However, the water droplet 12B that has lost kinetic energy by colliding with the article 100 does not have a large kinetic energy in a direction non-parallel to the direction of the arrow 35. Therefore, the intrusion of the water droplet 12B can be effectively suppressed by providing the uneven structure 10 only on the surface 5 or the surface 8.

[0048] 19, a case will be described in which a relatively small water droplet collides with the article 100. When the water droplet 12 penetrates the gap 3 of the article 100, if the uneven surface structure 10 is provided on the surface 5 or the surface 8, the water droplet 12 can accumulate on the surface of the uneven surface structure 10 as the water droplet 12C. By accumulating, the water droplet 12C acts as a stopper for other water droplets, and can prevent further intrusion of water droplets.

[0049] Furthermore, when parts 1 and 2 are produced by injection molding, if one attempts to provide concave-convex structure 10 on all of surfaces 4 to 9, it is difficult to demold one of the non-parallel surfaces, and it is not possible to successfully transfer concave-convex structure 10. In particular, when concave-convex structure 10 is applied to lens barrel 26 as shown in Fig. 14, the direction in which demolding is performed is perpendicular to the optical axis, so it is preferable to provide concave-convex structure 10 on surface 5 or surface 8 in Fig. 2.

[0050] From the above, by providing the uneven surface structure 10 on at least surface 5 or surface 8, a sufficient water-repellent effect can be achieved, and costs can also be reduced compared to providing the uneven surface structure 10 on all surfaces 4 to 9.

[0051] <Example> An example of the present invention will be described with reference to FIG. 20. FIG. 20(a) is an enlarged view of the concave-convex structure 10 described in the first embodiment. Meanwhile, FIG. 20(b) is a partial cross-sectional view showing an example in which the concave-convex structure 10 is formed on the operation ring 31 and the operation ring 32 of the imaging device 200 described in FIG. 13 and FIG. 14. In this example, the pitch P is 50 μm, the height H is 30 μm, the width R is 40 μm, the gap D is 0.2 mm, the shape of the convex portion 101 is a truncated cone shape, and they are arranged in a honeycomb shape. The operation ring 31 and the operation ring 32 are made of resin such as polycarbonate, and the concave-convex structure 10 is formed by injection molding.

[0052] A case where a water droplet 12 adheres to the surface of the imaging device 200 of this embodiment will be described with reference to Fig. 20(b). Even if the water droplet 12 drips into the gap 3, the uneven structure 10 creates a contact angle greater than 90° as described above, so that the force 13 generated in the gap 3 is oriented in a direction that suppresses the intrusion of the water droplet 12. Therefore, the uneven structure 10 can provide drip protection without using any article such as a packing.

[0053] The disclosure of the present invention is given below.

[0054] (Configuration 1) An article having opposing parts separated by a gap, the width of the gap being such that capillary action occurs, and at least one of the opposing parts has a concave-convex structure having a lotus effect.

[0055] (Configuration 2) The article according to configuration 1, wherein the width of the gap is 0.05 mm or more and 2 mm or less.

[0056] (Configuration 3) The article according to configuration 1 or 2, wherein the pitch of the convex portions of the concave-convex structure or the pitch of the concave-convex structure is 70 μm or less.

[0057] (Configuration 4) The article according to configuration 3, wherein the height of the protrusions or the depth of the recesses is 1 μm or more, and the width of the protrusions or the width of the recesses is 100 μm or less.

[0058] (Configuration 5) An article having parts facing each other with a gap therebetween, wherein at least one of the facing parts has a concave-convex structure, the pitch of the convex parts of the concave-convex structure or the pitch of the concave-convex structure is 70 μm or less, the height of the convex parts or the depth of the concave parts is 1 μm or more, the width of the convex parts or the width of the concave parts is 100 μm or less, and the width of the gap is 0.05 mm or more and 2 mm or less.

[0059] (Configuration 6) The article according to any one of configurations 1 to 5, characterized in that the article includes a first part and a second part opposing the first part, one of the opposing portions being provided on a surface of the first part opposing the second part, and the other of the opposing portions being provided on a surface of the second part opposing the first part.

[0060] (Configuration 7) An article comprising a first part and a second part opposed to the first part, with a gap provided between the first part and the second part, a concave-convex structure is provided on a surface of the first component facing the second component, the pitch of the convex portions of the concave-convex structure or the pitch of the concave-convex structure is 70 μm or less; The height of the protrusions or the depth of the recesses is 1 μm or more, The width of the convex portion or the width of the concave portion is 100 μm or less, An article characterized in that the width of the gap is 0.05 mm or more and 2 mm or less.

[0061] (Configuration 8) An article comprising a first part and a second part opposing the first part, with a gap between the first part and the second part, wherein the width of the gap is a width that exhibits capillary action, and the surface of the first part opposing the second part is provided with an uneven structure having a lotus effect.

[0062] (Structure 9) An article described in any one of Structures 6 to 8, characterized in that the surface of the first part facing the second part has a first portion and a second portion, the first portion is non-parallel to the second portion, the first portion does not have the uneven structure, and the second portion has the uneven structure.

[0063] (Configuration 10) The article described in configuration 9, characterized in that the first portion is located closer to the surface of the article than the second portion.

[0064] (Configuration 11) An article described in any one of Configurations 6 to 10, characterized in that the second part has a surface facing the first part provided with an uneven structure identical to the uneven structure provided on the first part.

[0065] (Configuration 12) The article according to any one of Configurations 1 to 11, wherein the protrusions or recesses of the uneven structure are arranged in a honeycomb pattern.

[0066] (Configuration 13) The article according to configuration 12, wherein the convex portion or the concave portion is cylindrical, conical, or truncated conical.

[0067] (Configuration 14) The article according to any one of configurations 1 to 13, characterized in that it is made of a material containing resin.

[0068] (Configuration 15) The article according to configuration 14, wherein the resin includes at least one of polycarbonate, polystyrene, and polypropylene.

[0069] (Configuration 16) An article described in any one of configurations 1 to 15, characterized in that the contact angle of the uneven structure is greater than 100°.

[0070] (Device 1) An optical device comprising the article according to any one of configurations 1 to 16 and a lens.

[0071] The above-described embodiments may be modified as appropriate without departing from the scope of the technical concept. For example, a plurality of embodiments may be combined. In addition, some of the features of at least one embodiment may be deleted or replaced.

[0072] In addition, new matters may be added to at least one embodiment. The disclosure of this specification includes not only what is explicitly described in this specification, but also all matters that can be understood from this specification and the drawings attached to this specification.

[0073] Furthermore, the disclosure of this specification includes the complement of each concept described in this specification. In other words, if this specification contains a statement that "A is greater than B," for example, even if the statement that "A is not greater than B" is omitted, this specification can be said to disclose that "A is not greater than B." This is because when a statement that "A is greater than B" is made, it is assumed that the case in which "A is not greater than B" is taken into consideration. [Explanation of symbols]

[0074] 3 Gap 5, 8 Opposite parts 10 Uneven structure 100 goods D Gap width

Claims

1. An article having parts facing each other with a gap therebetween, The width of the gap is a width that exhibits capillary action, An article, characterized in that at least one of the mutually opposing portions is provided with a concave-convex structure having a lotus effect.

2. 2. The article according to claim 1, wherein the width of the gap is 0.05 mm or more and 2 mm or less.

3. 3. The article according to claim 1, wherein the pitch of the convex portions of the concave-convex structure or the pitch of the concave-convex structure is 70 μm or less.

4. 4. The article according to claim 3, wherein the height of the protrusions or the depth of the recesses is 1 μm or more, and the width of the protrusions or the width of the recesses is 100 μm or less.

5. An article having parts facing each other with a gap therebetween, At least one of the opposing portions is provided with a concave-convex structure, The pitch of the convex portions of the concave-convex structure or the pitch of the concave-convex structure is 70 μm or less, The height of the convex portion or the depth of the concave portion is 1 μm or more, The width of the convex portion or the width of the concave portion is 100 μm or less, The article is characterized in that the width of the gap is 0.05 mm or more and 2 mm or less.

6. The article includes a first part and a second part facing the first part, and one of the portions facing each other is provided on a surface of the first part facing the second part, The article according to claim 1 or 5, wherein the other of the mutually opposing portions is provided on a surface of the second component that faces the first component.

7. An article comprising a first part and a second part opposed to the first part, with a gap provided between the first part and the second part, A concave-convex structure is provided on a surface of the first component facing the second component, The pitch of the convex portions of the concave-convex structure or the pitch of the concave-convex structure is 70 μm or less, The height of the convex portion or the depth of the concave portion is 1 μm or more, The width of the convex portion or the width of the concave portion is 100 μm or less, The article is characterized in that the width of the gap is 0.05 mm or more and 2 mm or less.

8. An article comprising a first part and a second part opposed to the first part, with a gap provided between the first part and the second part, The width of the gap is a width that exhibits capillary action, An article, characterized in that a concave-convex structure having a lotus effect is provided on a surface of the first component facing the second component.

9. the surface of the first component facing the second component has a first portion and a second portion; the first portion is non-parallel to the second portion; The article according to claim 7 or 8, wherein the first portion is not provided with the uneven structure, and the second portion is provided with the uneven structure.

10. 10. The article of claim 9, wherein the first portion is closer to the surface of the article than the second portion.

11. 8. The article according to claim 7, wherein the second part has a surface facing the first part, the surface being provided with an uneven structure identical to the uneven structure provided on the first part.

12. The article according to claim 1 or 5, wherein the projections or recesses of the uneven structure are arranged in a honeycomb pattern.

13. 8. The article according to claim 5 or 7, wherein the convex portion or the concave portion has a cylindrical shape, a conical shape, or a truncated conical shape.

14. 6. The article according to claim 1 or 5, which is formed from a material containing a resin.

15. 15. The article of claim 14, wherein the resin comprises at least one of polycarbonate, polystyrene, and polypropylene.

16. The article according to claim 1 or 5, wherein the contact angle of the uneven structure is greater than 100°.

17. An optical instrument comprising the article according to claim 1 or 5 and a lens.

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