Electronic device

Abstract

An electronic device according to one embodiment of the present invention is provided with a first case, a second case, and a first gasket. The first case has a first engagement part in which an engagement protrusion is formed. The second case has a second engagement part that receives the engagement protrusion and engages with the first engagement part. The first gasket constitutes either the first engagement part or the second engagement part. The first engagement part and the second engagement part are configured to maintain a state in which the first gasket is compressed in an engaged state in which engagement has concluded. The second engagement part has a stress relief part for relieving stress applied to the first gasket to a greater extent than a state of partial engagement in the engaged state.

Description

electronic equipment

[0001] The present technology relates to electronic devices.

[0002] Conventionally, technologies for providing waterproofing to electronic devices such as mobile terminals have been developed. For example, Patent Document 1 describes a mobile phone with waterproofing. This mobile phone has an upper housing and a lower housing. The lower housing is butted against the upper housing via a rubber band-like waterproof packing made of a rubber material and screwed in place. The lower housing is also provided with a battery cover equipped with the waterproof packing and a locking mechanism that rotates to detach the battery cover from the lower housing (see, for example, paragraphs

[0015] and

[0016] of the specification of Patent Document 1, and Figure 1).

[0003] JP 2008-10599 A

[0004] In recent years, there has been an increasing demand for repairing electronic devices to enable them to be used for a long period of time, and so there is a demand for structures that allow electronic devices to be easily assembled and disassembled.However, depending on the structure of the electronic device, there is a possibility that the waterproof structure may be damaged during assembly or disassembly, or that the waterproof structure may not be assembled properly, resulting in a loss of waterproof performance.

[0005] In view of the above circumstances, an object of the present technology is to provide an electronic device that can be easily assembled and disassembled while maintaining waterproof performance.

[0006] To achieve the above object, an electronic device according to one embodiment of the present technology includes a first case, a second case, and a first gasket. The first case has a first engagement portion having an engagement protrusion formed thereon. The second case has a second engagement portion that receives the engagement protrusion and engages with the first engagement portion. The first gasket constitutes either the first engagement portion or the second engagement portion. The first engagement portion and the second engagement portion are configured to maintain the first gasket in a compressed state in an engaged state where engagement is complete. The second engagement portion has a stress relief portion that relieves stress applied to the first gasket in the engaged state compared to a state in which engagement is in progress.

[0007] In this electronic device, either the first engagement portion provided on the first case and having an engagement protrusion, or the second engagement portion provided on the second case and receiving the engagement protrusion, is configured with a first gasket. In the engaged state, the first gasket is maintained in a compressed state. Furthermore, in the engaged state, a stress relief portion provided on the second engagement portion relieves stress on the first gasket compared to the partially engaged state. As a result, the restoring force of the first gasket maintains the engaged state, making it possible to realize an electronic device that is easy to assemble and disassemble while maintaining waterproof performance.

[0008] 1 is a schematic perspective view showing an external appearance of an electronic device according to an embodiment of the present technology; FIG. 2 is a schematic see-through perspective view showing an example of the internal configuration of the electronic device; FIG. 3 is a schematic exploded perspective view showing an example of the configuration of each part of the electronic device; FIG. 4 is a schematic partial cross-sectional view showing an example of the configuration of a rear case; FIG. 5 is a schematic partial cross-sectional view showing an example of the configuration of a front case; FIG. 6 is a schematic perspective view showing a process of assembling a case unit; FIG. 7 is a schematic perspective view showing a process of assembling a case unit and a peripheral band; FIG. 8 is a schematic cross-sectional view showing the rear case and the front case in a state in the middle of engagement; FIG. 9 is a schematic cross-sectional view showing the rear case and the front case in an engaged state; FIG. 10 is a schematic view showing an example of a waterproof structure using a first gasket; FIG. 11 is a schematic view showing another example of a waterproof structure using a first gasket; 10A and 10B are schematic diagrams for explaining the operation of a pressure regulating valve, and are schematic diagrams showing a configuration example of an electronic device given as a comparative example.

[0009] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0010] [Configuration of Electronic Device] Fig. 1 is a schematic perspective view showing the appearance of an electronic device according to an embodiment of the present technology. Fig. 2 is a schematic see-through perspective view showing an example of the internal configuration of the electronic device. Fig. 3 is a schematic exploded perspective view showing an example of the configuration of each part of the electronic device.

[0011] The electronic device 100 according to this embodiment is an electronic device such as a smartphone, and has a waterproof structure using a gasket. As shown in Fig. 3, the electronic device 100 includes an internal unit 10, a rear case 20, a front case 40, and an outer peripheral band 60. The electronic device 100 also includes a first gasket 1 and a second gasket 2.

[0012] Hereinafter, the side on which the rear case 20 is provided will be referred to as the rear side of the electronic device 100, and the opposite side will be referred to as the front side of the electronic device 100. A display 11 is provided on the front side of the electronic device 100. Figures 1 and 2 are assembly diagrams of the electronic device 100 as viewed from the rear side (the rear case 20 side). Figure 2 also shows the interior of the electronic device 100 as seen through the rear case 20.

[0013] 1 and 2 , in the electronic device 100, the rear case 20 and the front case 40 are attached to each other to form the case unit 3. The case unit 3 is a housing of the electronic device 100 that houses the internal unit 10. In this embodiment, the case unit 3 is configured as a plate-like structure having a rectangular planar shape. As shown in FIG. 3 , the rear side of the case unit 3 is covered by the rear case 20, but the front case 40 that forms the front side of the case unit 3 has an opening 4 formed therein to expose the display 11.

[0014] As shown in Fig. 2, the internal unit 10 has a display 11, a circuit board 12, a camera unit 13, a battery 14, an upper module 15, and a lower module 16. As shown in Fig. 3, a base substrate 17 is provided on the rear side of the display 11. The circuit board 12, the camera unit 13, the battery 14, the upper module 15, and the lower module 16 are arranged on the base substrate 17.

[0015] The display 11 is a thin-plate display element, such as an LCD or an organic EL display. The circuit board 12 is a board on which an arithmetic unit, memory, etc. for operating the electronic device 100 are mounted. The camera unit 13 constitutes a rear camera facing the rear of the electronic device 100, and is a unitized imaging element such as a CCD or CMOS. The battery 14 is a secondary battery that drives the electronic device 100. The upper module 15 and the lower module 16 are modules disposed on the upper and lower sides of the electronic device 100, and include components such as a microphone, speaker, vibrator, antenna, optical sensor, camera sensor, and light. The configuration of the internal units is not limited thereto.

[0016] The internal unit 10, which combines the components in this manner, is attached to the front case 40 so that the display surface of the display 11 faces forward and covers the opening 4. In this embodiment, the display 11 corresponds to an exposed component.

[0017] As shown in Fig. 3, the rear case 20 is a case that covers the rear side of the electronic device 100. The rear case 20 has a cover portion 21, a rear-side engagement portion 22, and a rear-side outer peripheral edge portion 23. The cover portion 21, the rear-side engagement portion 22, and the rear-side outer peripheral edge portion 23 are integrally molded using a resin material or the like. In the example shown in Fig. 3, the rear case 20 is provided with a first gasket 1. The first gasket 1 constitutes the rear-side engagement portion 22.

[0018] The cover unit 21 is a plate-like member that forms the rear surface of the electronic device 100. The cover unit 21 is provided with a photographic window 24 that is arranged to face the camera unit 13. The rear-side engaging portion 22 is a structural portion that engages with the front case 40 (front-side engaging portion 42). The rear-side engaging portion 22 is formed in an annular shape on the front side of the cover unit 21. The rear-side outer peripheral end portion 23 is a structural portion that is formed on the outer periphery of the cover unit 21 and protrudes outward from the connection position between the rear-side engaging portion 22 and the cover unit 21.

[0019] Fig. 4 is a schematic partial cross-sectional view showing an example of the configuration of the rear case 20. Fig. 4 schematically illustrates a part of a cross section obtained by cutting the rear case 20 in the thickness direction of the electronic device 100. As shown in Fig. 4, the rear-side engagement portion 22 has a support portion 25 and an engagement protrusion 26.

[0020] The support portion 25 is an annular wall that protrudes from the front side (the lower side in the figure) of the cover portion 21, and functions as a structure that supports the engaging protrusion 26. The support portion 25 is also disposed inside a side wall portion 45 of the front case 40, which will be described later, and forms the inner peripheral wall of the case unit 3. Here, the support portion 25 is configured to have a uniform thickness.

[0021] The engaging protrusion 26 is a convex engaging end that engages with the front case 40 (front-side engaging portion 42). In this embodiment, the engaging protrusion 26 is formed around the entire periphery of the tip portion of the annular support portion 25. In this embodiment, the rear-side engaging portion 22 corresponds to the first engaging portion on which the engaging protrusion is formed, and the rear case 20 corresponds to the first case having the first engaging portion.

[0022] 4, the engaging protrusion 26 is formed using the first gasket 1. That is, the first gasket 1 forms the engaging protrusion 26 in the rear-side engaging portion 22. Specifically, the first gasket 1 is provided so as to cover the front end of the tip portion of the support portion 25 and the inner and outer portions connected to the front end, and the first gasket 1 forms a convex engaging end.

[0023] The first gasket 1 is an elastic member made of a resin material such as silicone rubber, and functions as a waterproof member for realizing a waterproof structure. The first gasket 1 is formed at the tip of the support portion 25 by, for example, injection molding.

[0024] Returning to FIG. 3 , the front case 40 is provided on the front side of the electronic device 100 and, together with the display 11, constitutes the front surface of the electronic device 100. The front case 40 has a frame portion 41, a front-side engaging portion 42, and a front-side outer peripheral edge portion 43. The frame portion 41, the front-side engaging portion 42, and the rear-side outer peripheral edge portion 23 are integrally molded using a resin material or the like. The front case 40 also has an opening 4 surrounded by the front-side engaging portion 42.

[0025] The frame 41 is an annular plate member that forms a frame portion (bezel portion) that surrounds the display 11 on the front surface of the electronic device 100. The portion surrounded by the frame 41 forms the opening 4 for exposing the display 11. The front-side engaging portion 42 is a structural portion that engages with the rear case 20 (rear-side engaging portion 22). The front-side engaging portion 42 is formed in an annular shape on the rear side of the frame 41. The front-side outer peripheral end portion 43 is a structural portion that is formed on the outer periphery of the frame 41 and protrudes outward from the connection position between the front-side engaging portion 42 and the frame 41.

[0026] Fig. 5 is a schematic partial cross-sectional view showing an example of the configuration of the front case 40. Fig. 5 schematically illustrates a portion of a cross section of the front case 40 cut in the thickness direction of the electronic device 100. Fig. 5 illustrates a state in which the internal unit 10 is attached to the front case 40. As shown in Fig. 5, the front-side engagement portion 42 has a side wall portion 45 and an engagement groove portion 46.

[0027] The side wall portion 45 is an annular wall that protrudes from the rear side (upper side in the figure) of the frame portion 41, and functions as a structure in which the engagement groove portion 46 is formed. The side wall portion 45 is also disposed outside the support portion 25 of the rear case 20, and constitutes the outer peripheral wall of the case unit 3.

[0028] The engagement groove 46 is a concave engagement groove that engages with the rear case 20 (rear-side engagement portion 22). In this embodiment, a region in which the inner circumferential surface of the side wall 45 is recessed is formed around the entire circumference at a position a predetermined distance from the tip end (rear side) of the annular side wall 45 toward the base end (front side). This concave recess serves as the engagement groove 46 that receives the engagement protrusion 26 (first gasket 1) of the rear case 20. In this embodiment, the front-side engagement portion 42 corresponds to a second engagement portion that receives the engagement protrusion and engages with the first engagement portion, and the front case 40 corresponds to a second case having the second engagement portion.

[0029] In this embodiment, the front case 40 is provided with a second gasket 2. The second gasket 2 is an elastic member made of a resin material such as silicone rubber, similar to the first gasket 1. The second gasket 2 is provided between the front case 40 and the display 11. This makes it possible to waterproof the space between the front case 40 and the display 11, and to prevent water from entering from the front of the electronic device 100.

[0030] Here, the second gasket 2 is disposed closer to the frame 41 than the engagement groove 46 so as to surround the entire periphery of the opening 4. The lower part of Fig. 5 also illustrates the shape of the second gasket 2 in its free state. The second gasket 2 has a support portion 65 that supports the display 11, and a peripheral portion 66 that is provided on the outside of the support portion 65. The peripheral portion 66 is thicker than the support portion 65. The dotted line in the lower diagram indicates the amount of compression exerted by the display 11. The amount of compression for waterproofing is set to, for example, about 10% of the thickness.

[0031] 5, the peripheral edge 66, together with the side wall 45, constitutes the engagement groove 46 that receives the engagement protrusion 26 of the rear case 20. Here, the inner corner of the peripheral edge 66 is chamfered so as to receive the engagement protrusion 26. In this way, the engagement groove 46 may be formed using the second gasket 2.

[0032] So far, we have explained the waterproof structure using the first gasket 1 and the second gasket 2, but the case unit 3 is provided with an auxiliary engagement mechanism for engaging the rear case 20 and the front case 40. As shown in Figures 4 and 5, in this embodiment, the rear-side engagement portion 22 has a hook portion 28 that is different from the engagement mechanism using the first gasket 1, and the front case 40 has a hook receiver 48 that receives the hook portion 28. The hook portion 28 and the hook receiver 48 form the auxiliary engagement mechanism.

[0033] As shown in FIG. 4 , the hook portions 28 are protrusions partially provided on the outer periphery of the support portion 25 of the rear-side engagement portion 22. For example, a plurality of hook portions 28 are provided spaced apart on the outer periphery of the side wall portion 45. For example, the hook portions 28 are formed so that their cross sections in the thickness direction are triangular. Furthermore, the slope on the rear side (upper side in the drawing), to which an external force is applied during removal, is set at a steeper angle than the slope on the front side (lower side in the drawing).

[0034] 5, the hook receiving portion 48 is a through-hole provided on the side wall portion 45 of the front-side engagement portion 42, into which the hook portion 28 is inserted. Note that the hook receiving portion 48 does not have to be a through-hole, and may be, for example, a slot or the like. In this way, the hook portion 28 of the rear case 20 and the hook receiving portion 48 of the front case 40 engage with each other separately from the portion using the first gasket 1. This makes it possible to supplementarily maintain the engagement state provided by the first gasket 1.

[0035] Returning to FIG. 3 , the outer peripheral band 60 is an annular member having a width approximately equal to the thickness of the case unit 3. As described above, in this embodiment, the outer peripheral side surface 70 of the case unit 3 is formed by the front-side engagement portion 42 (side wall portion 45) of the front case 40. The outer peripheral band 60 is configured to cover the outer peripheral side surface 70 of the case unit 3. This makes it possible to prevent the rear case 20 and the front case 40 from being unintentionally disassembled. The configurations of the outer peripheral side surface 70 and the outer peripheral band 60 will be described in detail later with reference to FIGS. 15 and 16 , etc.

[0036] Here, a description will be given of the assembly process of the electronic device 100. Fig. 6 is a schematic perspective view showing the assembly process of the case unit. Fig. 7 is a schematic perspective view showing the assembly process of the case unit and the outer peripheral band.

[0037] As shown in Figure 6, first, the internal unit 10 is attached to the front case 40. As a result, the internal unit 10 is housed in the front case 40 with the display 11 in contact with the second gasket 2. Next, the rear case 20 is attached from the rear side of the front case 40. During this process, the front-side engaging portion 42 and the rear-side engaging portion 22 engage with each other, and the front case 40 and the rear case 20 are fixed to each other at a predetermined attachment position. At this time, the hook portion 28 and the hook receiving portion 48 also engage with each other, making it more difficult for the front case 40 and the rear case 20 to come off. In this manner, the case unit 3 is constructed.

[0038] Once the case unit 3 is constructed, the outer peripheral band 60 is attached to the case unit 3 as shown in FIG. 7 . The outer peripheral band 60 is attached so as to fit onto the outer peripheral side surface 70 of the case unit 3. This completes the assembly of the electronic device 100 as shown in FIG. 1 (or FIG. 2 ). As described above, in this embodiment, the electronic device 100 can be assembled without using screws or the like, and can be said to have a structure that facilitates assembly when the user repairs the electronic device 100 themselves. Furthermore, when disassembling the electronic device 100, the above-described assembly process is basically performed in reverse. The process of removing the outer peripheral band 60 will be described in detail later.

[0039] [Engagement of rear-side engaging portion 22 and front-side engaging portion 42] The process of engagement between the rear-side engaging portion 22 and the front-side engaging portion 42 will be described below. Fig. 8 is a schematic cross-sectional view showing the rear case and the front case in the middle of engagement. Fig. 9 is a schematic cross-sectional view showing the rear case and the front case in the engaged state.

[0040] In this disclosure, the "partially engaged state" refers to the state from the start of engagement between the rear-side engaging portion 22 and the front-side engaging portion 42 (the operation of attaching the rear case 20 and the front case 40) until the engagement is completed. In the partially engaged state, the rear-side engaging portion 22 and the front-side engaging portion 42 are not fully engaged, and sufficient engagement is not achieved.

[0041] In the present disclosure, the engaged state refers to a state in which the rear-side engaging portion 22 and the front-side engaging portion 42 are fully engaged with each other. For example, as shown in FIG. 9 , the engagement is completed when the cover portion 21 supporting the rear-side engaging portion 22 abuts against the tip of the side wall portion 45 of the front-side engaging portion 42. This state occurs when the rear case 20 abuts against a component of the front case 40 and cannot be inserted any further. The insertion depth required for the engaged state may have some play. For example, even if there is a gap between the tip of the side wall portion 45 and the cover portion 21, the engaged state can be achieved if certain conditions are met (e.g., the insertion depth of the engaging protrusion 26 exceeds a predetermined threshold, or the force required to separate the rear-side engaging portion 22 and the front-side engaging portion 42 exceeds a predetermined threshold).

[0042] First, the state during engagement will be described. As shown in Figure 8, when the rear-side engagement portion 22 is introduced into the front-side engagement portion 42, the engagement protrusions 26 and hook portions 28 of the rear-side engagement portion 22 come into contact with the side wall portions 45 of the front-side engagement portion 42. As the rear-side engagement portion 22 is further introduced, the side wall portions 45 are pushed by the engagement protrusions 26 and hook portions 28 and bend outward. Note that while the state in which the side wall portions 45 are bent outward is given as an example here, it is also possible that the support portions 25 of the rear-side engagement portion 22 will bend inward due to a reaction force from the side wall portions 45.

[0043] Furthermore, in the partially engaged state, the first gasket 1 constituting the engaging protrusion 26 is compressed by being pressed against the side wall 45 of the front engaging portion 42. When an elastic body such as the first gasket 1 is compressed by an external force, the greater the amount of compression from its natural state (hereinafter referred to as the "squeezing amount"), the greater the stress inside the elastic body. Therefore, in the partially engaged state, the stress on the first gasket 1 increases, and a restoring force acts to return it to its natural shape.

[0044] Next, the engaged state will be described. As shown in Figure 9, in the engaged state, the engaging protrusion 26 (first gasket 1) of the rear-side engaging portion 22 fits into the engaging groove 46 provided in the front-side engaging portion 42. Also, the hook portion 28 of the rear-side engaging portion 22 fits into the hook receiving portion 48 of the front-side engaging portion 42. In this case, the deflection of the side wall portion 45 of the front-side engaging portion 42, which occurred in Figure 8, is eliminated. As a result, the side wall portion 45 of the front-side engaging portion 42 and the support portion 25 of the rear-side engaging portion 22 return to their natural state as shown in Figures 4 and 5, and are arranged so as to face each other in a parallel state.

[0045] On the other hand, the engaging protrusion 26 (first gasket 1) fitted into the engaging groove 46 is pressed and compressed by the side wall 45 constituting the engaging groove 46 and the second gasket 2. In other words, in the engaged state, the first gasket 1 does not return to its natural shape, but maintains a compressed state in which it has been crushed by a predetermined amount.

[0046] As described above, in this embodiment, the rear-side engaging portion 22 and the front-side engaging portion 42 are configured to maintain the first gasket 1 in a compressed state when engagement is complete. The amount of compression at this time is set to, for example, about 15% to 30% of the thickness of the first gasket 1 in order to maintain airtightness. This allows the first gasket 1 to function as a waterproofing member, thereby providing waterproof performance for the electronic device 100.

[0047] Furthermore, the rear-side engagement portion 22 has a stress relief portion 5 that relieves stress applied to the first gasket 1 in the engaged state compared to the intermediate engagement state. In other words, the stress relief portion 5 is a mechanism that reduces stress that increases inside the first gasket 1 during engagement. Methods for relieving stress include changing the shape of the first gasket 1 and changing the amount of compression per unit length (the rate of compression).

[0048] As described above, in the engaged state, the first gasket 1 is compressed by a predetermined amount, and therefore the stress relief portion 5 does not reduce the stress applied to the first gasket 1 to zero (for example, it does not return the first gasket 1 to its natural shape).

[0049] For example, as shown in FIG. 8 , when the rear-side engagement portion 22 is inserted into the front-side engagement portion 42, the first gasket 1 (engagement protrusions 26) is compressed by pressure from the sidewall portion 45 until it reaches the engagement groove 46. When the first gasket 1 (engagement protrusions 26) subsequently reaches the engagement groove 46, the previously compressed first gasket 1 escapes into the space created by the engagement groove 46, reducing the amount of compression. Therefore, the space created by the engagement groove 46 serves as an escape space for the compressed first gasket 1 to escape. Thus, in the example shown in FIG. 8 , the engagement groove 46 provided in the front-side engagement portion 42 functions as a stress relief portion 5. In this case, the engagement groove 46 reduces the amount of compression of the first gasket 1 in the engaged state compared to when it is partially engaged. This relieves the stress applied to the first gasket 1.

[0050] In order to increase the stress again in the first gasket 1 after the stress has been relaxed, energy is required to compress the first gasket 1. In other words, without a sufficient external force, the first gasket 1 cannot be moved from the engaged state. This means that the first gasket itself functions as a member that prevents the front case 40 and rear case 20 from separating, thereby realizing a state in which the case unit 3 is held in place.

[0051] In this way, the rear-side engaging portion 22 and the front-side engaging portion 42 compress the first gasket 1 when engaged, but when assembled in a predetermined position (engaged state), the amount of compression of the first gasket 1 is reduced compared to when engaged, and the configuration and shape are such that the first gasket 1 remains compressed enough to ensure airtightness even in that state. In other words, simply by fitting the rear-side engaging portion 22 and the front-side engaging portion 42 together until the components abut, it is possible to achieve an engagement structure that exhibits waterproofing functionality. This makes it possible to achieve an electronic device that is easy to assemble and disassemble while maintaining waterproofing performance.

[0052] 9 , in this embodiment, a second gasket 2 is provided between the display 11 and the front case 40. Furthermore, the first gasket 1 (engagement protrusions 26) provided on the rear case 20 presses the display 11 against the second gasket 2 in the engaged state. In other words, the flat plate portion provided on the outer edge of the display 11 is sandwiched between the first gasket 1 and the second gasket 2.

[0053] This forms a highly airtight waterproof area on the rear side of the display 11. In this way, the first gasket 1 can maintain the tight contact between the display 11 and the front case 40 while maintaining the engagement between the rear case 20 and the front case 40. This makes it possible to further improve waterproof performance.

[0054] 9 , in this embodiment, in the attached state, the hook portions 28 of the rear case 20 and the hook receiving portions 48 of the front case 40 engage with each other. This makes it possible to prevent separation of the rear case 20 and the front case 40, which are engaged by the first gasket 1, for example. This improves the reliability of the electronic device 100. Note that while the hook portions 28 and the hook receiving portions 48 function to prevent separation of the cases, they are not necessarily provided because the first gasket 1 also has a self-retaining function (separation prevention).

[0055] 9, the outer peripheral band 60 is attached after the assembly is completed to the engaged state. For example, as described with reference to FIG. 8, in the process of attaching the rear case 20 to the front case 40, it is conceivable that the front case 40 (side wall portion 45) will be pushed outward by the hook portion 28 of the rear case 20. This also occurs when the rear case 20 is separated from the front case 40.

[0056] The outer periphery band 60 prevents such deformation by surrounding the front case 40 (side wall portion 45) from the outside, thereby making it possible to sufficiently prevent the front case 40 and the rear case 20 from unintentionally separating. The outer periphery band 60 also protects and conceals the fastening functional parts (front-side engaging portion 42 and rear-side engaging portion 22). This prevents the first gasket 1 and other components from becoming dirty or damaged, improving reliability. The outer periphery band 60 can also be used as a decorative component to accentuate the appearance of the electronic device 100.

[0057] The following describes configuration examples of a waterproof structure using the first gasket 1. The four configuration examples described below are all waterproof structures in which the first gasket 1 is provided between the rear case 20 and the front case 40 and the stress relaxation portion 5 is provided.

[0058] Fig. 10 is a schematic diagram showing an example of a waterproof structure using a first gasket. The waterproof structure 75a shown in Fig. 10 is a structure in which the first gasket 1 fits into a predetermined space surrounded by inner and outer wall surfaces, maintaining an engaged state that is difficult to disengage due to stress relaxation of the first gasket 1 and maintaining waterproof function. The waterproof structure 75a includes a rear case 20a provided with a rear-side engaging portion 22a and a front case 40a provided with a front-side engaging portion 42a. The rear case 20a and the front case 40a are attached to each other to form a case unit 3a.

[0059] Fig. 10A is a cross-sectional view of the rear-side engagement portion 22a, Fig. 10B is a cross-sectional view of the front-side engagement portion 42a, Fig. 10C is a cross-sectional view of the waterproof structure 75a showing the engagement state of the rear-side engagement portion 22a and the front-side engagement portion 42a, and Fig. 10D is a configuration example in which the waterproof structure 75a is provided with a display 11.

[0060] 10A , the rear-side engagement portion 22a has a support portion 25a protruding from a rear case main body 27a and an engagement protrusion 26a provided at the tip of the support portion 25a. In the waterproof structure 75a, the first gasket 1 is provided on the rear case 20a and forms the engagement protrusion 26a. The first gasket 1 is, for example, integrally molded with the rear case 20a.

[0061] As shown in FIG. 10B , the front-side engaging portion 42a has a groove 49a provided in the front case main body 47a. The groove 49a sandwiches the rear-side engaging portion 22a from both the inside and outside of the case unit 3a. The groove 49a has, as surfaces that contact the first gasket 1, a first contact surface 51a provided on the introduction side where the rear-side engaging portion 22a is introduced, and a second contact surface 52a provided on the rear side of the first contact surface 51a. The second contact surface 52a is configured as a surface that is recessed more than the first contact surface 51a. In other words, the groove 49a can be considered a groove with a wide step on the rear side.

[0062] For example, in the partially engaged state, the first gasket 1 (engagement protrusion 26a) is compressed by the narrow space sandwiched between the first contact surfaces 51a on the introduction side. Meanwhile, as shown in FIG. 10C , in the engaged state, the first gasket 1 escapes into the wider space sandwiched between the second contact surfaces 52a on the rear side, thereby alleviating stress compared to the partially engaged state. This causes the first gasket 1 itself to be compressed by the groove 49a of the front case 40a, thereby maintaining airtightness and achieving a self-retaining function. Note that in FIG. 10C , the engaged state is when the tip of the groove 49a abuts against the rear case main body 27a, which supports the engagement protrusion 26a.

[0063] Thus, in the waterproof structure 75a, the stress relief portion 5 is the relief space 6 that allows the first gasket 1, which is crushed during engagement, to escape. Here, the relief space 6 is formed by recessing the second contact surface 52a relative to the first contact surface 51a. The relief space 6 is configured so that the first gasket 1 is compressed to an amount that allows the first gasket 1 to exhibit its waterproof function. Therefore, in the engaged state, the stress of the first gasket 1 is relieved by the relief space 6 while maintaining a range that maintains its waterproof function. Furthermore, in order to release the engaged state (to peel it off), the first gasket 1 needs to be contracted (stress increased) through the relief space 6, which prevents unintended disassembly.

[0064] In addition, in the waterproof structure 75a, the engaging protrusions 26a (first gasket 1) are sandwiched from the inside and outside in the grooves 49a. As a result, the reaction force generated when the first gasket 1 is crushed acts symmetrically on the grooves 49a. This cancels out the reaction forces, and no lateral pressure is generated on the entire case unit 3a.

[0065] The dimensions of each part of the waterproof structure 75a are defined as follows. The front and rear ends refer to the upper and lower ends in the drawing. The front case 40a and the rear case 20a are in contact with each other at their reference surfaces. Rear reference surface: end surface of rear case main body 27a that abuts against groove portion 49a Front reference surface: tip of groove portion 49a A1: distance from rear reference surface to front end of engaging protrusion 26a A2: distance from rear reference surface to rear end of engaging protrusion 26a A3: distance from front reference surface to front end of relief space 6 (second contact surface 52a) (depth of groove 49a) A4: distance from front reference surface to rear end of relief space 6 (second contact surface 52a) A5: width of support portion 25a A6: width of engaging protrusion 26a A7: width on introduction side of groove 49a (spacing of first contact surfaces 51a) A8: width on rear side of groove 49a (spacing of second contact surfaces 52a)

[0066] A1 < A3 (Condition CA1) Condition (CA1) ensures that the escape space 6 into which the first gasket 1, which is crushed during engagement, can move in the engaged state. A2 > A4 (Condition CA2) Condition (CA2) ensures that the first gasket 1 reaches the escape space 6 in the engaged state and undergoes stress relaxation. A6 > A8 > A7 (Condition CA3) Condition (CA3) ensures that the first gasket 1 is compressed from its natural state in the engaged state and can maintain the engaged state through stress relaxation. A7 = (A6 - A5) x 0.5 (Condition CA4) Condition (CA4) ensures that the amount of compression of the first gasket 1 to release the engagement is 50%, thereby improving slip-out prevention performance. A8 = (A6 - A5) x 0.25 (Condition CA5) Condition (CA5) ensures that the amount of compression of the first gasket 1 in the engaged state is 25%, ensuring reliable waterproof performance. The amount of compression under condition (CA5) may be adjusted appropriately, for example, within the range of 10% to 40%. Furthermore, chamfering (C-face machining) may be performed on all corners along the path that the first gasket 1 (engaging protrusions 26a) passes through during attachment and detachment.

[0067] 10C , when the engaging protrusion 26a is inserted into the groove 49a, if the air inside the groove 49a is compressed and the pressure increases, a force pushing back the engaging protrusion 26a may occur, potentially preventing proper engagement. Therefore, in the waterproof structure 75a, the front engaging portion 42a is provided with an air vent 44a that releases air from the groove 49a during engagement. The air vent 44a is a through-hole that communicates with the interior of the groove 49a. This allows the rear engaging portion 22a and the front engaging portion 42a to properly engage with each other.

[0068] 10D shows a configuration in which the display 11 is held on the front case 40a side using a waterproof structure 75a. In this configuration, a holder 50a that holds the display 11 is provided inside the rear case main body 27a. In this case, in the engaged state, the holder 50a holds the display 11 from the rear side. This allows the display 11 to be tightly attached to the second gasket 2.

[0069] Fig. 11 is a schematic diagram showing another example of a waterproof structure using a first gasket. The waterproof structure 75b shown in Fig. 11 is a structure in which the thickness of the first gasket 1 is intentionally changed when the engaging end fits into the space surrounded by the first gasket 1, so that in the engaged state, the first gasket 1 holds the engaging end by its restoring force (stress relaxation) and maintains its waterproof function. The waterproof structure 75b includes a rear case 20b provided with a rear-side engaging portion 22b and a front case 40b provided with a front-side engaging portion 42b. The rear case 20b and the front case 40b are attached to each other to form a case unit 3b.

[0070] 11A, the rear-side engagement portion 22b has a support portion 25b protruding from a rear case main body 27b and an engagement protrusion 26b provided at the tip of the support portion 25b. The engagement protrusion 26b is a structural portion formed by expanding the tip of the support portion 25b, and is made of, for example, the same material as the rear case main body 27b and the support portion 25b.

[0071] 11B, the front-side engagement portion 42b has a support groove 54b provided in the front case main body 47b and an engagement groove 46b formed inside the support groove 54b. In the waterproof structure 75b, the first gasket 1 is provided in the front case 40b and forms the engagement groove 46b. The first gasket 1 is, for example, integrally molded with the front case 40b.

[0072] The support groove 54b is a groove that opens toward the rear side of the front case 40b and supports the first gasket 1. The support groove 54b has, as surfaces that support the first gasket 1 (engagement groove 46b), a first support surface 51b provided on the introduction side where the rear-side engagement portion 22b is introduced, and a second support surface 52b provided on the rear side of the first support surface 51b. The second support surface 52b is configured as a surface that is recessed more than the first support surface 51b. In other words, the support groove 54b can be said to be a groove with a wide step on the rear side.

[0073] The engagement groove 46b is a groove that sandwiches the rear-side engagement portion 22b from the inside and outside of the case unit 3b, and is formed using the first gasket 1. A straight groove with a constant width that opens toward the rear side of the front case 40b is formed in the first gasket 1. This straight groove serves as the engagement groove 46b that sandwiches the rear-side engagement portion 22b. The first gasket 1 is also disposed along the first support surface 51b and the second support surface 52b formed inside the support groove 54b. Therefore, it can be said that the thickness of the first gasket 1 is one step thicker at the back side in the engagement groove 46b.

[0074] For example, when engagement begins, the engaging protrusion 26b of the rear engaging portion 22b is introduced into the straight engaging groove 46b. The first gasket 1 is provided on the introduction side in a narrow space sandwiched between the first support surfaces 51b, and the thickness of the first gasket 1 is smaller than that of the rear side. Thus, during the engagement process, the thinner first gasket 1 is pressed and compressed by the bulge of the engaging protrusion 26b.

[0075] On the other hand, as shown in Figure 11C, in the engaged state, the engaging protrusion 26b is introduced to a predetermined position on the rear side of the engaging groove 46b. At the rear side, the first gasket 1 is provided in a wider space sandwiched between the second support surfaces 52b, and the thickness of the first gasket 1 is greater than that on the introduction side. Therefore, in the engaged state, the thicker first gasket 1 is pressed and compressed by the bulge of the engaging protrusion 26b, just like on the introduction side. Note that in Figure 11C, the engaged state is when the tip of the support groove 54b abuts against the rear case main body 27b that supports the engaging protrusion 26b.

[0076] Therefore, in the front-side engaging portion 42b, the rate at which the first gasket 1 is crushed is relatively smaller on the rear side than on the introduction side. This reduces the stress on the first gasket 1 in the engaged state compared to the intermediate engagement state. This means that the force that the engaging protrusions 26b receive from the first gasket 1 is smaller in the engaged state than in the intermediate engagement state. Due to this effect, the first gasket 1 is compressed by the engaging protrusions 26b that have been introduced all the way to the rear side, maintaining airtightness and achieving a self-retaining function.

[0077] Thus, in the waterproof structure 75b, the stress relief portion 5 is a thick portion 7 of the first gasket 1, which is located further back than the introduction side where the rear-side engagement portion 22b is introduced. The thick portion 7 is a shape that intentionally increases the thickness of the first gasket 1 so as to reduce the rate at which the first gasket 1 is crushed in the engaged state. Here, the thick portion 7 is formed by recessing the second support surface 52b below the first support surface 51b. The thick portion 7 is configured so that the first gasket 1 is compressed to an extent that allows the first gasket 1 to exhibit its waterproof function. Therefore, in the engaged state, the stress of the first gasket 1 is relieved by the thick portion 7 while maintaining the waterproof function. Furthermore, to release the engaged state, a force is required to pull out the engagement protrusion 26b (a force that compresses the thin portion of the first gasket 1), which prevents unintended disassembly.

[0078] Furthermore, in the waterproof structure 75b, the engaging protrusions 26b are sandwiched from the inside and outside by the engaging grooves 46b (first gasket 1). As a result, the reaction force generated when the first gasket 1 is crushed acts symmetrically on the support grooves 54b that support the first gasket 1. This cancels out the reaction forces, and no lateral pressure is generated on the entire case unit 3b.

[0079] Here, the dimensions of each part of the waterproof structure 75b are defined as follows: The front case 40b and the rear case 20b are in contact with each other at their reference surfaces. Rear reference surface: end surface of rear case main body 27b abutting on support groove portion 54b Front reference surface: tip of support groove portion 54b B1: distance from rear reference surface to front end of engagement protrusion portion 26b B2: distance from rear reference surface to rear end of engagement protrusion portion 26b B3: distance from front reference surface to front end of support groove portion 54b (depth of support groove portion 54b) B4: distance from front reference surface to front end of thick portion 7 B5: distance from front reference surface to front end of engagement groove portion 46b (depth of engagement groove portion 46b) B6: width of support portion 25b B7: width of engagement protrusion portion 26b B8: width on the back side of support groove portion 54b (spacing of second support surface 52b) B9: width on the introduction side of support groove portion 54b (spacing of first support surface 51b) B10: width of engagement groove portion 46b

[0080] B1 < B5 < B3 (Condition CB1) Condition (CB1) is a condition for accommodating the engaging protrusion 26b in the engaging groove 46b. B1 > B2 > B4 (Condition CB2) Condition (CB2) ensures that the engaging protrusion 26b is inserted all the way to the back where the thick-walled portion 7 is located, thereby preventing the engaging protrusion 26b from coming off. B6 ≧ B10 (Condition CB3) Condition (CB3) is a condition for accommodating the support portion 25b that supports the engaging protrusion 26b in the engaging groove 46b. This condition also allows the first gasket 1 to be tightly fitted around the support portion 25b, improving waterproof performance. B8 > B9 > B7 > B10 (Condition CB4) Condition (CB4) is a condition for properly compressing the first gasket 1. This condition allows the first gasket 1 to be compressed so as to provide the anti-slip function (stress relaxation) of the engaging protrusions 26b. (B7 - B10) = (B9 - B10) x 0.5 (Condition CB5). Condition (CB5) requires the first gasket 1 to be compressed by 50% to release the engagement, improving anti-slip performance. (B7 - B10) = (B8 - B10) x 0.25 (Condition CB6). Condition (CB6) requires the first gasket 1 to be compressed by 25% in the engaged state, ensuring waterproof performance. The amount of compression in condition (CA5) may be adjusted appropriately, for example, within the range of 10% to 40%. Additionally, chamfering (C-face machining) may be performed on all corners along the path through which the engaging protrusions 26b pass during attachment and detachment.

[0081] Furthermore, as shown in FIG. 11C , when the engaging protrusion 26b is inserted into the engaging groove 46b, pressure increases inside the engaging groove 46b. That is, the pressure inside the groove formed by the first gasket 1 increases. Therefore, in the waterproof structure 75b, an air vent (not shown) is provided in the rear-side engaging portion 22b to allow air to escape from the engaging groove 46b during engagement. Here, the air vent is, for example, a groove formed along the engaging protrusion 26b and connecting to the rear side of the engaging groove 46b. This allows the rear-side engaging portion 22b and the front-side engaging portion 42b to be properly engaged with each other.

[0082] 11D shows a configuration in which the display 11 is held on the front case 40b side using a waterproof structure 75b. In this configuration, similar to FIG. 10D, a holder 50b that holds the display 11 is provided on the inside of the rear case main body 27b. This allows the display 11 to be tightly attached to the second gasket 2.

[0083] FIG. 12 is a schematic diagram showing another example of a waterproof structure using a first gasket. The waterproof structure 75c shown in FIG. 12 is a structure in which the first gasket 1 fits into a predetermined groove provided in the side wall of a case member, maintaining an engagement state that is difficult to disengage and waterproof function due to stress relaxation of the first gasket 1. The waterproof structure 75c utilizes, for example, the outer half of the waterproof structure 75a shown in FIG. 10. Alternatively, the waterproof structure 75c may be configured using the inner half of the waterproof structure 75a. The waterproof structure 75c includes a rear case 20c provided with a rear-side engaging portion 22c and a front case 40c provided with a front-side engaging portion 42c. The rear case 20c and the front case 40c are attached to form a case unit 3c.

[0084] 12A , the rear-side engagement portion 22c has a support portion 25c protruding from a rear case main body 27c and an engagement protrusion 26c provided at the tip of the support portion 25c. In the waterproof structure 75c, the first gasket 1 is provided on the rear case 20c and forms the engagement protrusion 26c. Here, the first gasket 1 is disposed from the front end of the support portion 25c to the outer peripheral surface, and the engagement protrusion 26c protruding outward is formed.

[0085] As shown in FIG. 12B , the front-side engaging portion 42c has a sidewall portion 45c provided on the front case main body 47c. The sidewall portion 45c presses the rear-side engaging portion 22c from the outside of the case unit 3c. The sidewall portion 45c also has, as surfaces that contact the first gasket 1, a first contact surface 51c provided on the introduction side where the rear-side engaging portion 22c is introduced, and a second contact surface 52c provided on the rear side of the first contact surface 51c. The second contact surface 52c is configured as a surface that is recessed more than the first contact surface 51c. This forms a stepped shape on the inside of the sidewall portion 45c that is recessed toward the introduction side.

[0086] For example, in the partially engaged state, the first gasket 1 (engagement protrusion 26c) is compressed by the first contact surface 51c on the introduction side. On the other hand, in the engaged state, as shown in Fig. 12C, the first gasket 1 escapes into the recess (escape space 6) formed by the second contact surface 52c on the rear side, thereby alleviating stress compared to the partially engaged state.

[0087] Thus, in the waterproof structure 75c, the stress relief portion 5 is an escape space 6 that allows the first gasket 1, which is crushed during engagement, to escape. Here, the escape space 6 is formed by recessing the second contact surface 52c more than the first contact surface 51c. The escape space 6 is configured so that the first gasket 1 is compressed to an extent that allows it to exhibit its waterproof function. As a result, the first gasket 1 itself is compressed by the stepped shape of the front case 40c, maintaining airtightness and achieving a self-retaining function.

[0088] As shown in FIG. 12C , in the waterproof structure 75c, when the first gasket 1 is compressed, an inward reaction force 78 acts on the rear case 20c (engagement protrusions 26c) and an outward reaction force 77 acts on the front case 40c (side wall portions 45c). This is also true for the waterproof structure 75d shown in FIG. 13 , which will be described later. Such reaction forces can be offset by forming a cross-sectional shape that is line-symmetrical or by providing a structural member that receives the reaction force. This point will be described later with reference to FIG. 14 .

[0089] Here, the dimensions of each part of the waterproof structure 75c are defined as follows. The front case 40c and the rear case 20c are assumed to contact each other at their reference surfaces. When engaged, the outer surfaces of the front case 40c and the rear case 20c form the same surface (assumed reference surface). The assumed reference surfaces of the cases are not necessarily the same surface due to the influence of reaction forces, etc. Rear reference surface: end surface of the rear case main body 27c that abuts against the side wall portion 45c Front reference surface: tip end of the side wall portion 45c Rear assumed reference surface: outer side surface of the rear case main body 27c Front assumed reference surface: outer side surface of the side wall portion 45c C1: distance from the rear reference surface to the front end of the engaging protrusion 26c C2: distance from the rear reference surface to the rear end of the engaging protrusion 26c C3: distance from the front reference surface to the front end of the relief space 6 (second contact surface 52c) C4: distance from the front reference surface to the rear end of the relief space 6 (second contact surface 52c) C5: distance from the rear assumed reference surface to the outer side surface of the support portion 25c C6: distance from the rear assumed reference surface to the outer end of the engaging protrusion 26c C7: distance from the front assumed reference surface to the first contact surface 51c C8: distance from the front assumed reference surface to the second contact surface 52c

[0090] C1 < C3 (Condition CC1) Condition (CC1) ensures that the escape space 6 into which the first gasket 1, which is crushed during engagement, can move in the engaged state. C2 > C4 (Condition CC2) Condition (CC2) ensures that the first gasket 1 reaches the escape space 6 in the engaged state and undergoes stress relaxation. C7 > C8 > (C5 - C6) (Condition CC3) Condition (CC3) ensures that the first gasket 1 is compressed from its natural state in the engaged state and can maintain the engaged state through stress relaxation. C7 = (C5 - C6) x 0.5 (Condition CC4) Condition (CC4) ensures that the amount of compression of the first gasket 1 to release the engagement is 50%, thereby improving slip-out prevention performance. C8 = (C5 - C6) x 0.25 (Condition CC5) Condition (CC5) results in the first gasket 1 being compressed by 25% in the engaged state, ensuring waterproof performance. The amount of compression under condition (CC5) may be adjusted appropriately, for example, within the range of 10% to 40%. Furthermore, chamfering (C-face machining) may be performed on all corners along the path that the first gasket 1 (engaging protrusions 26c) passes through during attachment and detachment.

[0091] 12D shows a configuration in which the display 11 is held on the front case 40c side using a waterproof structure 75c. In this configuration, a holder 50c that holds the display 11 is provided on the inside of the rear case main body 27c. This allows the display 11 to be tightly attached to the second gasket 2.

[0092] FIG. 13 is a schematic diagram showing another example of a waterproof structure using a first gasket. The waterproof structure 75d shown in FIG. 13 is a structure in which the thickness of the first gasket 1 is intentionally changed when the engaging end fits into the space surrounded by the first gasket 1, so that in the engaged state, the first gasket 1 holds the engaging end by its restoring force (stress relaxation) while maintaining its waterproof function. The waterproof structure 75d utilizes, for example, the outer half of the waterproof structure 75b shown in FIG. 11 . Alternatively, the waterproof structure 75d may be configured using the inner half of the waterproof structure 75b. The waterproof structure 75d includes a rear case 20d provided with a rear-side engaging portion 22d and a front case 40d provided with a front-side engaging portion 42d. The rear case 20d and the front case 40d are attached to form a case unit 3d.

[0093] 13A , the rear-side engagement portion 22d has a support portion 25d protruding from a rear case main body 27d and an engagement protrusion 26d provided at the tip of the support portion 25d. The engagement protrusion 26d is a structural portion formed by bulging outward from the tip of the support portion 25d.

[0094] 13B , the front-side engagement portion 42d has a side wall portion 45d provided on the front case main body 47d and an engagement receiving portion 46d formed on the inside of the side wall portion 45d. In the waterproof structure 75d, the first gasket 1 is provided on the front case 40d and forms the engagement receiving portion 46d. The first gasket 1 is, for example, integrally molded with the front case 40d.

[0095] The sidewall portion 45d supports the first gasket 1 (engagement receiving portion 46d) and presses the rear-side engagement portion 22d from the outside of the case unit 3d via the first gasket 1. The sidewall portion 45d has, as surfaces for supporting the first gasket 1, a first support surface 51d provided on the introduction side where the rear-side engagement portion 22d is introduced, and a second support surface 52d provided on the rear side of the first support surface 51d. The second support surface 52d is configured as a surface that is recessed more than the first support surface 51d. As a result, a stepped shape is formed on the inside of the sidewall portion 45d, with the rear side recessed relative to the introduction side.

[0096] The engagement receiving portion 46d is a portion that receives the engagement protrusion 26d of the rear-side engagement portion 22d and is formed using a first gasket 1. The first gasket 1 is configured so that an engagement surface 55d that contacts the engagement protrusion 26d is a flat surface along the introduction direction of the engagement protrusion 26d (the up-down direction in the figure). The first gasket 1 is also disposed along the first support surface 51d and the second support surface 52d formed on the side wall portion 45d. Therefore, it can be said that the thickness of the first gasket 1 is one step thicker at the rear end of the engagement receiving portion 46d. The engagement receiving portion 46d also has a bottom surface 56d that receives the front end of the engagement protrusion 26d. The bottom surface 56d is, for example, a surface that is perpendicular to the engagement surface 55d.

[0097] For example, at the start of engagement, the engaging protrusion 26d is introduced while compressing the thinner portion of the engaging receiving portion 46d (first gasket 1). Meanwhile, as shown in FIG. 13C , in the engaged state, the engaging protrusion 26d is introduced to a predetermined position on the rear side of the engaging receiving portion 46d. Because the thickness of the first gasket 1 is greater on the rear side than on the introduction side, the rate at which the first gasket 1 is crushed is relatively smaller than on the introduction side. This reduces the stress on the first gasket 1 in the engaged state compared to when the gasket is in the middle of engagement.

[0098] As described above, in the waterproof structure 75d, the stress relief portion 5 is a thick portion 7 of the first gasket 1 that is provided on the rear side of the introduction side where the rear-side engagement portion 22d is introduced, and that makes the thickness of the first gasket 1 greater than that of the introduction side. Here, the thick portion 7 is formed by recessing the second support surface 52d further from the first support surface 51d. The thick portion 7 is configured so that the first gasket 1 is compressed to an extent that allows it to exhibit its waterproof function. As a result, the first gasket 1 is compressed by the engagement protrusion 26d that is introduced all the way to the rear side, thereby maintaining airtightness and achieving a self-retaining function.

[0099] The dimensions of each part of the waterproof structure 75d are defined as follows: The front case 40d and the rear case 20d are in contact with each other at their reference surfaces. In the engaged state, the outer surfaces of the front case 40d and the rear case 20d form the same plane (the assumed reference surface). Rear reference surface: end surface of the rear case main body 27d that abuts against the side wall portion 45d Front reference surface: tip end of the side wall portion 45d Rear assumed reference surface: outer side surface of the rear case main body 27d Front assumed reference surface: outer side surface of the side wall portion 45d D1: distance from the rear reference surface to the front end of the engaging protrusion 26d D2: distance from the rear reference surface to the rear end of the engaging protrusion 26d D3: distance from the front reference surface to the front end (bottom surface portion 56d) of the engaging receiving portion 46d D4: distance from the front reference surface to the front end of the thick portion 7 D5: distance from the rear assumed reference surface to the outer side surface of the support portion 25d D6: distance from the outer side surface of the support portion 25d to the outer end of the engaging protrusion 26d D7: distance from the front assumed reference surface to the engaging surface 55d D8: distance from the second support surface 52d to the engaging surface 55d D9: distance from the first support surface 51d to the engaging surface 55d

[0100] D1 < D3 (Condition CD1) Condition (CD1) is the condition for the entire engaging protrusion 26 to be received by the engaging receiving portion 46d. D1 > D2 > D4 (Condition CD2) Condition (CD2) allows the engaging protrusion 26d to be inserted all the way to the back where the thick-walled portion 7 is located, thereby enabling the engaging protrusion 26d to exhibit its slip-out prevention function. D6 < D9 (Condition CD3) Condition (CD3) is the condition for compressing the first gasket 1. D6 = D9 x 0.5 (Condition CD4) Condition (CD4) requires the first gasket 1 to be compressed by 50% to release the engagement, improving slip-out prevention performance. D6 = D8 x 0.25 (Condition CD5) Condition (CD5) requires the first gasket 1 to be compressed by 25% in the engaged state, ensuring waterproof performance. The amount of crushing in condition (CD5) may be adjusted appropriately within the range of, for example, 10% to 40%. Also, chamfering (C-face processing) may be performed on all corners along the path that the engaging protrusion 26d passes through during attachment and detachment.

[0101] 13D shows a configuration in which the display 11 is held on the front case 40d side using a waterproof structure 75d. In this configuration, a holder 50d that holds the display 11 is provided on the inside of the rear case main body 27d. This allows the display 11 to be tightly attached to the second gasket 2.

[0102] The following describes the reaction force generated by compressing the first gasket 1 in the waterproof structure 75c shown in Fig. 12 and the waterproof structure 75d shown in Fig. 13. Here, the reaction force acting on the front case (front cases 40c and 40d) due to the compression of the first gasket 1 is referred to as reaction force 77, and the reaction force acting on the rear case (rear cases 20c and 20d) due to the compression of the first gasket 1 is referred to as reaction force 78.

[0103] For example, as shown in FIG. 12C , in waterproof structure 75c, compression of the first gasket 1 causes a reaction force 78 to act inward against the rear case 20c (engagement protrusions 26c) and an outward reaction force 77 to act outward against the front case 40c (side wall portions 45c). Also, as shown in FIG. 13C , in waterproof structure 75d, compression of the first gasket 1 causes a reaction force 78 to act inward against the rear case 20d (engagement protrusions 26d) and an outward reaction force 77 to act outward against the front case 40d (side wall portions 45d). Therefore, inward lateral pressure acts on the rear cases 20c and 20d, and outward lateral pressure acts on the front cases 40c and 40d. If such lateral pressure is not resolved, the first gasket 1 may be displaced from its proper engagement position or may be compressed less than expected, potentially resulting in reduced waterproof performance.

[0104] FIG. 14 is a schematic diagram illustrating a configuration for canceling a reaction force. One method for canceling the reaction force generated by compressing the first gasket 1 is to make the cross-sectional shape line-symmetric. In this method, the waterproof structure is configured so that the cross-sectional shape is line-symmetric in a cross section along the direction in which the reaction force 78 or 77 is applied. For example, the entire periphery of the case may have the same cross-sectional shape. In FIG. 14A, a waterproof structure 75c is configured so that the cross-sectional structure is line-symmetric. Similarly, in FIG. 14B, a waterproof structure 75d is configured so that the cross-sectional structure is line-symmetric.

[0105] For example, in FIG. 14A , a reaction force 78 received by the engaging protrusion 26c on the left side of the figure is offset by a reaction force 78' received by the engaging protrusion 26c on the right side of the figure, thereby canceling out the reaction forces received by the entire rear case 20c. Also in FIG. 14A , a reaction force 77 received by the side wall 45c on the left side of the figure is offset by a reaction force 77' received by the side wall 45c on the right side of the figure, thereby canceling out the reaction forces received by the entire front case 40c. Similarly, in FIG. 14B , reaction forces 78 and 78' received by the engaging protrusion 26d on the left and right sides of the figure are offset by each other, thereby canceling out the reaction forces received by the entire rear case 20d. Also in FIG. 14B , reaction forces 77 and 77' received by the side wall 45d on the left and right sides of the figure are offset by each other, thereby canceling out the reaction forces received by the entire front case 40d. This eliminates the need for components for offsetting reaction forces, allowing the engagement mechanism to be configured compactly.

[0106] Another method for canceling the reaction force is to provide a backup member 79 that presses down on the member receiving the reaction force from the side opposite to the side on which the reaction force acts. In this example, the backup member 79 that presses down on the rear case is provided on the front case side. In this embodiment, the backup member 79 corresponds to the engagement assisting portion.

[0107] 14C , a backup member 79c is provided on the front-side engagement portion 42c that constitutes a waterproof structure 75c. In the engaged state, the backup member 79c presses the rear-side engagement portion 22c (engagement protrusion 26c) from the side opposite the side wall portion 45c. Because the engagement protrusion 26c receives an inward reaction force 78, an inward force 77' acts on the backup member 79c from the engagement protrusion 26c, and an outward reaction force 78' acts on the engagement protrusion 26c from the backup member 79c. As a result, the inward reaction force 78 and the outward reaction force 78' acting on the rear case 20c cancel each other out, and the outward reaction force 77 and the inward force 77' acting on the front case 40c cancel each other out.

[0108] 14D , a backup member 79d is provided on a front-side engagement portion 42d that constitutes a waterproof structure 75d. When the front-side engagement portion 42d is engaged, the backup member 79d presses the rear-side engagement portion 22d (engagement protrusion 26d) from the side opposite the side wall portion 45d. Because the engagement protrusion 26d receives an inward reaction force 78, an inward force 77' acts on the backup member 79d from the engagement protrusion 26d, and an outward reaction force 78' acts on the engagement protrusion 26d from the backup member 79d. As a result, the inward reaction force 78 and the outward reaction force 78' acting on the rear case 20d cancel each other out, and the outward reaction force 77 and the inward force 77' acting on the front case 40d cancel each other out.

[0109] In this way, by providing the backup member 79, it is possible to cancel the reaction force acting on the rear case and the front case inside the engagement mechanism. For example, in cases where it is structurally difficult to construct a line-symmetrical cross-sectional structure, such a backup member 79 may be used to cancel the reaction force. Note that, contrary to the configuration shown in FIGS. 14C and 14D , the backup member 79 that presses the front case may be provided on the rear case side. In this case, for example, the backup member 79 is provided on the rear case so as to press the side wall portion (side wall portion 45c and side wall portion 45d) of the front case from the outside. Even with this configuration, it is possible to cancel the reaction force inside the engagement mechanism.

[0110] [Method of Attaching and Detaching Outer Peripheral Band] Hereinafter, a method of attaching and detaching the outer peripheral band provided on the case unit 3 described with reference to Figures 1 to 9 etc. will be described. Figure 15 is a schematic diagram showing an example of the configuration of the outer peripheral side surface 70 of the case unit 3 to which the outer peripheral band 60 is attached.

[0111] 15A is a plan view of the electronic device 100 (case unit 3) as seen from the rear side with the peripheral band 60 attached. The rear case 20 is not shown here. The peripheral band 60 is provided on a peripheral side surface 70 of the case unit 3. Note that in this embodiment, the peripheral side surface 70 is formed by the front case 40, but the present technology is also applicable when the peripheral side surface 70 is formed by the rear case 20.

[0112] The outer peripheral band 60 is an elastically deformable band-shaped member. The outer peripheral band 60 is formed, for example, from a thin metal such as aluminum in a frame shape so that its planar shape is rectangular. Alternatively, the outer peripheral band 60 may be made of a resin material such as ABS resin. The width of the outer peripheral band 60 is set to be equal to or smaller than the width of the outer peripheral side surface 70 so that it fits within the outer peripheral side surface 70.

[0113] The outer peripheral side surface 70 is a side surface formed on the outer periphery of the case unit 3. In this embodiment, the rear outer peripheral end portion 23 (see FIG. 4, etc.) formed by the rear case 20 and the front outer peripheral end portion 43 (see FIG. 5, etc.) formed by the front case 40 are provided so as to protrude outward from the outer peripheral side surface 70. As a result, the outer periphery of the case unit 3 has a groove-like structure with the outer peripheral side surface 70 as its bottom surface. The outer peripheral band 60 is attached to the outer peripheral side surface 70 by fitting into this groove-like structure.

[0114] 15A , the outer peripheral side surface 70 has a mounting surface 71 and a pair of cutouts 72. The mounting surface 71 is the surface of the outer peripheral side surface 70 that forms the portions other than the cutouts 72. For example, the outer peripheral band 60 is held in contact with the mounting surface 71. The rear outer peripheral end portion 23 and the front outer peripheral end portion 43 are configured to protrude from the mounting surface 71 by a length approximately equal to the thickness of the outer peripheral band 60. For this reason, in a normal state, the outer peripheral band 60 is barely visible from the thickness direction of the case unit 3.

[0115] The pair of cutouts 72 are provided at diagonal positions in the case unit 3, which has a rectangular planar shape, and are portions for allowing the outer peripheral band 60 to escape. Fig. 15A shows the cutout 72 formed in the upper left when viewing the electronic device 100 from the rear. The other cutout 72 is provided in the lower right of the electronic device 100, diagonally opposite the cutout 72. This pair of cutouts 72 is a structure for allowing the outer peripheral band 60 to escape when attaching or detaching the electronic device.

[0116] 15A , the cutout 72 is formed in an L-shaped range that includes the corner of the outer peripheral side surface 70, and is recessed inward from the mounting surface 71. A step is formed at both ends of the cutout 72 with respect to the mounting surface 71. Note that, in a normal state, the outer peripheral band 60 is not in contact with the cutout 72. The depth of the cutout 72 is set to, for example, approximately the same as the thickness of the outer peripheral band 60, but is not limited to this and may be set appropriately depending on the size of the case unit 3, etc., so that the outer peripheral band 60 is detachable.

[0117] 15B, when the outer peripheral band 60 is pressed inward at a corner where a notch 72 is provided, the outer peripheral band 60 moves inward to contact the notch 72. Furthermore, because the outer peripheral band 60 is not fixed to the case unit 3, it rises in both the longitudinal and lateral directions, using the steps formed at both ends of the notch 72 as fulcrums. As a result, as shown in FIG. 15C, for example, at corners where no notch 72 is provided, the outer peripheral band 60 lifts up, bulging outward and away from the attachment surface 71.

[0118] 16 is a schematic diagram for explaining how to attach and detach the outer circumferential band 60. When removing the outer circumferential band 60, as shown in FIG. 16, the outer circumferential band 60 is pressed inward at both diagonal corners where the cutouts 72 are provided (the upper left and lower right corners in the figure). In this case, the outer circumferential band 60 rises up at the diagonal corners where the cutouts 72 are not provided (the upper right and lower left corners in the figure).

[0119] In this case, the outer peripheral band 60 escapes to the notches 72 at the two diagonal corners, so the outer peripheral band 60 rises up to a greater extent than when, for example, one corner is pressed. This makes it possible to achieve the amount of lift required to remove the outer peripheral band 60. By pulling up the outer peripheral band 60 from the raised portion in this way, it can be removed from the case unit 3. However, if the outer peripheral band 60 is pressed only at one corner, the outer peripheral band 60 will not rise up enough and therefore cannot be removed.

[0120] When attaching the outer periphery band 60, for example, the outer periphery band 60 is hooked onto the case unit 3 at one corner where the notch 72 is provided, and then the outer periphery band 60 is fitted onto the outer periphery side surface 70 of the case unit 3 while pressing the corner diagonal to the part where the outer periphery band 60 is hooked onto the case unit 3. This makes it possible to easily attach the outer periphery band 60.

[0121] In this way, by providing two notches 72 at diagonal corners, it is possible to prevent the electronic device 100 from being unintentionally disassembled. For example, if the electronic device 100 is dropped, it is conceivable that a corner of the electronic device 100 may be pressed. However, even if only one corner with the notch 72 is pressed, the outer periphery band 60 will not come off. Furthermore, it is difficult to remove the outer periphery band 60 unless the specified diagonal corners are pressed simultaneously. This leads to the prevention of disassembly without following the proper disassembly procedure. This makes it possible to prevent the electronic device 100 from being disassembled erroneously.

[0122] The outer peripheral band 60 also functions to conceal the engagement points of the rear engagement portion 22 and the front engagement portion 42, as well as the engagement points of the hook portion 28 and the hook receiving portion 48. This makes it possible to prevent contamination or damage to the engagement points.

[0123] Furthermore, when the outer peripheral band 60 is removed, steps (rear-side outer peripheral end 23 and front-side outer peripheral end 43) connecting the rear case 20 and the front case 40 along the outer peripheral side surface 70 are exposed. By hooking a fingertip on this step, the case unit 3 can be easily disassembled. From another perspective, when the outer peripheral band 60 is attached, the shape that serves as a trigger for disassembling the case unit 3 is concealed. This makes it possible to reliably prevent, for example, the case unit 3 from being unintentionally disassembled.

[0124] [Pressure Regulating Valve] In this embodiment, the airtightness of the case unit 3 is maintained by the above-described waterproof structures (for example, waterproof structure 75a in FIG. 10 , waterproof structure 75b in FIG. 11 , waterproof structure 75c in FIG. 12 , waterproof structure 75d in FIG. 13 , etc.). When such a waterproof terminal is used in the atmosphere, a problem occurs in which the housing expands / contracts due to changes in air pressure outside the terminal. In particular, in environments such as while mountain climbing or on an airplane, low air pressure can cause the terminal to expand, potentially breaking the airtightness.

[0125] Therefore, in this embodiment, a pressure adjustment valve for equalizing the pressure inside and outside the terminal is provided in the case unit 3. Fig. 17 is a schematic see-through perspective view showing an example of the configuration of the pressure adjustment valve. In this example, the pressure adjustment valve 80 is provided on the upper side surface of the rear case 20 of the case unit 3. The position where the pressure adjustment valve 80 is provided is not limited.

[0126] The pressure regulating valve 80 has a valve body 81, a valve fixing portion 82, a discharge portion 83, a release groove 84, and an operation hole 85. The valve body 81 is an elongated, plate-shaped elastic member and is arranged along the upper side surface of the rear case 20. The valve fixing portion 82 fixes one end of the valve body 81 to the rear case 20. The discharge portion 83 is provided on the lower side of the valve body 81 and is a member that constitutes a discharge port 86 that penetrates the side surface of the rear case 20. The discharge portion 83 is formed, for example, using an elastic body or the like so that it can come into close contact with the valve body 81. The release groove 84 is a groove provided on the lower side of the valve body 81 and is arranged on the opposite side of the discharge portion 83 from the valve fixing portion 82. The operation hole 85 is a through-hole that penetrates the front case 40 and is formed facing the release groove 84.

[0127] Figure 18 is a schematic diagram for explaining the operation of the pressure adjustment valve. Figure 18A shows the state of the pressure adjustment valve 80 during exhaust operation. For example, when the pressure inside the case unit 3 rises, pressure is applied to the exhaust port 86, pushing up the valve body 81. This creates a gap between the exhaust port 86 and the valve body 81, allowing the air 8 inside the case unit 3 to escape through the gap and reduce the pressure.

[0128] When the external pressure is high, the valve body 81 is held in close contact with the discharge part 83, and the discharge port 86 is closed. Therefore, the valve body 81 basically opens the discharge port 86 only when the pressure inside the case unit 3 is high. As a result, the inside of the case unit 3 is basically maintained at normal pressure, which is the same as the external pressure, or at negative pressure, which is lower than the external pressure.

[0129] The pressure regulating valve 80 functions as an exhaust valve that releases the pressure inside the case unit 3 to the outside of the case unit 3. In other words, the pressure regulating valve 80 works to release the air inside the case unit 3 to the outside so that the pressure becomes normal pressure or negative pressure. This allows the air inside to be released to the outside when the outside pressure is low (such as when climbing a mountain). The air inside can also be released when the case unit 3 is pressed. It is also possible to release air that expands due to heat generation or the like in the internal unit 10 of the case unit 3 to the outside. This makes it possible to prevent situations in advance where the airtightness of the case unit is broken due to high pressure inside.

[0130] 18B shows the state of the pressure regulating valve 80 during cracking operation. Here, cracking operation refers to the operation of forcibly opening the exhaust port 86 of the pressure regulating valve 80 to normalize the pressure inside the case unit 3. During cracking operation, with the outer peripheral band 60 removed, a rod-shaped member is inserted into the operation hole 85, and the valve body 81 is pushed into the release groove 84. This makes it possible to forcibly create a gap between the valve body 81 and the exhaust portion 83, allowing air 8 to be taken in from the outside and normalize the internal pressure.

[0131] In this way, the operation hole 85 and release groove 84 provided in the pressure adjustment valve 80 function as a cracking mechanism that introduces air into the inside of the case unit 3 by operation from outside the case unit 3.

[0132] For example, the operation of the exhaust valve shown in Figure 18A is an operation to maintain the relationship of internal pressure < external pressure, but it is expected that disassembly of the case unit 3 will be difficult because the case unit 3 is being pressed by atmospheric pressure. In contrast, in this embodiment, when disassembling the case unit 3, the cracking mechanism of the pressure adjustment valve 80 can be used to allow air to flow in from the outside. This makes the inside of the case unit 3 equal to the outside pressure, and cancels the atmospheric pressure acting on the gasket. As a result, the case unit 3 can be easily disassembled.

[0133] As described above, in the electronic device 100 according to this embodiment, either the rear-side engaging portion 22 provided on the rear case 20 and having the engaging protrusions 26, or the front-side engaging portion 42 provided on the front case 40 and receiving the engaging protrusions 26, is configured with the first gasket 1. In the engaged state, the first gasket is maintained in a compressed state. Furthermore, in the engaged state, the stress relief portion 5 provided on the front-side engaging portion 42 relieves the stress applied to the first gasket 1 compared to the partially engaged state. As a result, the restoring force of the first gasket 1 maintains the engaged state, making it possible to realize an electronic device that is easy to assemble and disassemble while maintaining waterproof performance.

[0134] Generally, methods using waterproof double-sided tape or adhesives as water-stopping members for achieving waterproof structures are known. For example, when disassembling components assembled using waterproof double-sided tape, the components are heated to approximately 80°C to 90°C, causing the waterproof double-sided tape to peel off. In this case, the tape breaks and new tape is required. Furthermore, waterproof double-sided tape is a very thin component, and a dedicated jig or similar tool is required for proper application. Furthermore, when an adhesive is used, for example, if the adhesive has high adhesion, the component may be damaged, which may require the replacement of related components. Furthermore, dedicated equipment is required to apply the adhesive. For this reason, when waterproof double-sided tape or adhesive is used, it is difficult for general users to assemble and disassemble equipment.

[0135] Another known method uses a gasket as a waterproofing member. In this case, a mechanism for crushing the gasket is provided in the component to which the gasket is attached. Fig. 19 is a schematic diagram showing an example of the configuration of an electronic device as a comparative example. In this electronic device 101, a ring-shaped gasket 112 is disposed between a rear case 110 and a front case 111. The rear case 110 and the front case 111 are screwed together with the gasket 112 sandwiched therebetween.

[0136] In this way, if the waterproofing mechanism using a gasket is achieved by screw fastening or the like, even an ordinary user can disassemble and assemble the device with just a tool such as a screwdriver. On the other hand, with a method using screws, the required amount of crushing (crushing pressure) can be obtained near the screw fastening point, but the amount of crushing may be reduced in areas away from the screw due to bending of the components. In this case, the airtightness of the gasket may be reduced, potentially leading to a deterioration in waterproof performance.

[0137] In this embodiment, either the rear-side engaging portion 22 or the front-side engaging portion 42 is configured by the first gasket 1. The front-side engaging portion 42 is provided with a stress relief portion 5 (escape space 6 and thick portion 7) that relieves stress on the first gasket 1 to the extent that the first gasket 1 can maintain its waterproof performance. This makes it possible to maintain airtightness and achieve a self-retaining function by utilizing the elastic deformation of the first gasket 1 itself.

[0138] As a result, when disassembling, it is only necessary to separate the rear case 20 and the front case 40, and disassembly can be performed without damaging the first gasket 1. Furthermore, there is no need to separately place the first gasket 1 during assembly; simply attaching the rear case 20 and the front case 40 makes it possible to form a waterproof structure. Furthermore, when the cases are assembled (engaged), the first gasket 1 remains in a state in which it can maintain its waterproof performance by itself. This makes it possible to avoid a situation in which the first gasket 1 is locally crushed, reducing the airtightness in other areas. As a result, it is possible to maintain the waterproof function both during assembly and disassembly and after assembly.

[0139] Furthermore, electronic device 100 can be assembled and disassembled without using adhesives, double-sided tape, screws, etc. This allows users to replace internal components themselves, making it possible to meet requests such as the right to repair the product. Furthermore, since no special equipment or tools are required during manufacturing or repair, it is possible to reduce capital investment required to manufacture electronic device 100.

[0140] It is also possible to combine at least two of the features of the present technology described above. That is, the various features described in each embodiment may be arbitrarily combined without distinguishing between the embodiments. Furthermore, the various effects described above are merely examples and are not intended to be limiting, and other effects may also be achieved.

[0141] In the present disclosure, the terms "same," "equal," "orthogonal," etc. are concepts that include "substantially the same," "substantially equal," "substantially orthogonal," etc. For example, they also include states that fall within a predetermined range (e.g., a range of ±10%) based on "completely the same," "completely equal," "completely orthogonal," etc.

[0142] The present technology can also be configured as follows. (1) An electronic device comprising: a first case having a first engagement portion on which an engagement protrusion is formed; a second case having a second engagement portion that receives the engagement protrusion and engages with the first engagement portion; and a first gasket constituting either the first engagement portion or the second engagement portion, wherein the first engagement portion and the second engagement portion are configured to maintain a compressed state of the first gasket in an engagement state in which engagement is complete, and the second engagement portion has a stress relaxation portion that relieves stress applied to the first gasket in the engaged state compared to an intermediate engagement state. (2) The electronic device described in (1), wherein the stress relaxation portion reduces the amount of crushing of the first gasket in the engaged state compared to an intermediate engagement state. (3) The electronic device described in (1) or (2), wherein the first gasket is provided on the first engagement portion, and the stress relaxation portion is an escape space that allows the first gasket crushed during engagement to escape. (4) The electronic device according to (3), wherein the second engaging portion has, as a surface that contacts the first gasket, a first contact surface provided on an introduction side where the first engaging portion is introduced and a second contact surface provided further back than the first contact surface, and the second contact surface is recessed further than the first contact surface to form the escape space. (5) The electronic device according to (1) or (2), wherein the first gasket is provided on the second engaging portion, and the stress relaxation portion is a thick portion that is provided on the first gasket further back than the introduction side where the first engaging portion is introduced, and that makes the first gasket thicker than the introduction side. (6) The electronic device according to (5), wherein the second engagement portion has, as surfaces for supporting the first gasket, a first support surface provided on the introduction side where the first engagement portion is introduced and a second support surface provided on the inner side of the first support surface, the first gasket is arranged along the first support surface and the second support surface, and the second support surface forms the thick portion by being recessed from the first support surface.(7) The electronic device described in any one of (1) to (6), wherein the first case and the second case are attached to each other to form a case unit, and the second engagement portion has a groove portion that sandwiches the first engagement portion from the inside and outside of the case unit. (8) The electronic device described in (7), wherein at least one of the first engagement portion and the second engagement portion has an air vent portion that lets air escape from the groove portion during engagement. (9) The electronic device described in any one of (1) to (6), wherein the first case and the second case are attached to each other to form a case unit, and the second engagement portion has a side wall portion that presses the first engagement portion from either the inside or the outside of the case unit. (10) The electronic device described in (9), wherein the second engagement portion has an engagement auxiliary portion that presses the first engagement portion from the side opposite to the side wall portion in the engaged state. (11) The electronic device according to any one of (1) to (10), wherein the second case has an opening surrounded by the second engagement portion, and further comprises an exposed component attached to the second case so as to be exposed from the opening, and a second gasket provided between the second case and the exposed component, and the first engagement portion holds the exposed component so as to press it against the second gasket in the engaged state. (12) The electronic device according to any one of (1) to (11), wherein one of the first engagement portion and the second engagement portion has a hook portion different from the engagement mechanism using the first gasket, and the other of the first engagement portion and the second engagement portion has a hook receiving portion that receives the hook portion. (13) An electronic device according to any one of (1) to (12), wherein the first case and the second case are attached to each other to form a case unit, one of the first engaging portion and the second engaging portion forms an outer peripheral side surface of the case unit, and further comprising an outer peripheral band configured to cover the outer peripheral side surface.(14) The electronic device according to (13), wherein the case unit is a plate-like structure having a rectangular planar shape, and the outer peripheral side surface has a pair of notches provided at diagonal positions to allow the outer peripheral band to escape. (15) The electronic device according to any one of (1) to (14), wherein the first case and the second case are attached to each other to form a case unit, and the case unit has an exhaust valve that releases internal pressure to the outside. (16) The electronic device according to (15), wherein the exhaust valve has a cracking mechanism that introduces air into the inside of the case unit by operating from outside the case unit.

[0143] DESCRIPTION OF SYMBOLS 1...First gasket 2...Second gasket 3, 3a, 3b, 3c, 3d...Case unit 5...Stress relaxation portion 6...Relief space 7...Thick portion 20, 20a, 20b, 20c, 20d...Rear case 22, 22a, 22b, 22c, 22d...Rear side engaging portion 26, 26a, 26b, 26c, 26d...Engaging protrusion 40, 40a, 40b, 40c, 40d...Front case 42, 42a, 42b, 42c, 42d...Front side engaging portion 46d...Engaging receiving portion 46, 46b...Engaging groove portion 49a...Groove portion 60...Outer peripheral band 79...Backup member 80...Pressure adjustment valve 100...Electronic device

Claims

1. An electronic device comprising: a first case having a first engagement portion on which an engagement protrusion is formed; a second case having a second engagement portion that receives the engagement protrusion and engages with the first engagement portion; and a first gasket that constitutes either the first engagement portion or the second engagement portion, wherein the first engagement portion and the second engagement portion are configured to maintain a compressed state of the first gasket in an engaged state where engagement is complete, and the second engagement portion has a stress relaxation portion that relieves stress on the first gasket in the engaged state compared to when it is in an intermediate engagement state.

2. An electronic device according to claim 1, wherein the stress relief portion reduces the amount of compression of the first gasket in the engaged state compared to the partially engaged state.

3. An electronic device according to claim 1, wherein the first gasket is provided in the first engagement portion, and the stress relaxation portion is an escape space for the first gasket to escape if it is crushed during engagement.

4. An electronic device as described in claim 3, wherein the second engagement portion has, as surfaces that come into contact with the first gasket, a first contact surface provided on the introduction side where the first engagement portion is introduced, and a second contact surface provided on the back side of the first contact surface, and the second contact surface forms the escape space by being recessed further than the first contact surface.

5. An electronic device according to claim 1, wherein the first gasket is provided on the second engagement portion, and the stress relaxation portion is a thick portion of the first gasket that is provided on the inner side of the first gasket relative to the introduction side where the first engagement portion is introduced, and that makes the first gasket thicker than the introduction side.

6. An electronic device according to claim 5, wherein the second engagement portion has, as surfaces for supporting the first gasket, a first support surface provided on the introduction side where the first engagement portion is introduced and a second support surface provided on the back side of the first support surface, the first gasket is arranged along the first support surface and the second support surface, and the second support surface forms the thick portion by being recessed from the first support surface.

7. An electronic device according to claim 1, wherein the first case and the second case are attached to each other to form a case unit, and the second engaging portion has grooves that sandwich the first engaging portion from the inside and outside of the case unit.

8. An electronic device according to claim 7, wherein at least one of the first engaging portion and the second engaging portion has an air vent portion that releases air from the groove portion during engagement.

9. An electronic device according to claim 1, wherein the first case and the second case are attached to each other to form a case unit, and the second engaging portion has a side wall portion that presses the first engaging portion from either the inside or outside of the case unit.

10. An electronic device according to claim 9, wherein the second engaging portion has an engaging auxiliary portion that presses the first engaging portion from the side opposite the side wall portion in the engaged state.

11. An electronic device as described in claim 1, wherein the second case has an opening surrounded by the second engagement portion, and further comprises an exposed component attached to the second case so as to be exposed from the opening, and a second gasket provided between the second case and the exposed component, and the first engagement portion presses the exposed component against the second gasket in the engaged state.

12. An electronic device according to claim 11, wherein one of the first engaging portion and the second engaging portion has a hook portion different from the engaging mechanism using the first gasket, and the other of the first engaging portion and the second engaging portion has a hook receiving portion that receives the hook portion.

13. An electronic device according to claim 1, wherein the first case and the second case are attached to each other to form a case unit, one of the first engaging portion and the second engaging portion forms an outer peripheral side surface of the case unit, and further comprising an outer peripheral band configured to cover the outer peripheral side surface.

14. An electronic device according to claim 13, wherein the case unit is a plate-like structure having a rectangular planar shape, and the outer peripheral side surface has a pair of cutouts provided at diagonal positions to allow the outer peripheral band to escape.

15. An electronic device according to claim 1, wherein the first case and the second case are attached to each other to form a case unit, and the case unit has an exhaust valve for releasing internal pressure to the outside.

16. An electronic device according to claim 15, wherein the exhaust valve has a cracking mechanism that introduces air into the inside of the case unit by operating from outside the case unit.

Images