Portable terminal

Abstract

To prevent erroneous mounting when assembling an operation button.SOLUTION: The portable terminal 1 is provided with a cubic casing having a side peripheral part 2, a bottom surface part 3 and a liquid crystal display device 4, and operation buttons 61 and 62, and operation button holes 23 and 24 are formed in the side peripheral part 2. On a first surface and a second surface opposed to each other of the operation button holes 23, 24 and the operation buttons 61, 62, reverse assembly preventing structures Bk1, Bk2 composed of a recessed shape and a projecting shape are formed. When the attachment positions and directions of the operation buttons 61 and 62 are different, the operation buttons 61 and 62 are raised by the uneven shape, and it is possible to recognize that the operation buttons 61 and 62 are wrong. Since the reverse assembly preventing structures Bk1 and Bk2 are formed on the first surface and the second surface facing each other, the portable terminal 1 can be designed such that the operation buttons 61 and 62 constituting a part of the appearance configuration of the portable terminal 1 are minimal and have a sense of unity.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a so-called watch-type portable terminal device worn on the wrist, and to a portable terminal device equipped with operation buttons. [Background technology]

[0002] Small-sized portable terminal devices that are worn on the wrist, so-called watch-type portable terminal devices, have become widespread. For example, there are watch-type (wrist-worn type devices, which usually have a watch function but also include those that do not) mobile terminal devices that have the ability to communicate via Bluetooth (registered trademark), allowing users to check emails received on their smartphones, make calls via their smartphones, and even output music played on their smartphones at their fingertips. There are also watch-type portable terminal devices that are equipped with functions such as a call function, a music playback function, a communication function to the Internet, etc., and a voice output function based on the communication function. In addition, with the rise in awareness of health management, smartwatches and other watch-type portable terminal devices have become popular, which can be worn on parts of the body such as the wrist, fingers, or legs to easily measure vital information while going about one's daily life, and which also have the above-mentioned functions (communication function, music playback function, etc.). Furthermore, mobile terminal devices such as smartphones and tablets have become widespread.

[0003] Such various mobile terminal devices are equipped with buttons (push buttons) for turning the power on and off and for controlling the built-in functions. If such buttons are attached to the device body in the wrong direction, or if there are multiple types, they are attached in the wrong position, this will affect work efficiency. To address this issue, conventionally, incorrect assembly is prevented by making the outer shapes of the buttons asymmetric (asymmetrical with respect to a point or axis), by giving each button a different shape, or by changing the color of each button. For example, if there is one button, it is made trapezoidal, and if there are multiple buttons, one button is made circular and the other square, to prevent installation errors. Furthermore, by providing protrusions on the peripheral side of the button and making the mounting hole for the button a keyhole shape that fits the protrusions, incorrect assembly is prevented.

[0004] Incidentally, minimalist and unified designs are now being sought in various fields, and the same is true for mobile terminal devices. However, the conventional button structure and design used to prevent incorrect assembly did not allow for minimalist, unified buttons. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-5237 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to prevent incorrect installation when assembling an operation button. [Means for solving the problem]

[0007] (1) The invention described in claim 1 provides a mobile terminal device comprising: a housing having a side periphery, a bottom surface, and a liquid crystal display device arranged on the side periphery facing the bottom surface; a plurality of operation buttons arranged on the side periphery; a switch arranged within the housing for detecting depression of the operation buttons; a plurality of operation button holes formed on the side periphery into which the operation buttons are inserted; and a plurality of reverse assembly prevention structures formed on each of the opposing surfaces of the plurality of operation button holes and the plurality of operation buttons. (2) The invention described in claim 2 provides the mobile terminal device described in claim 1, characterized in that each of the plurality of reverse-assembly prevention structures has a reverse-assembly prevention convex portion formed on one side of the operation button hole and the operation button and protruding toward the other side, and a reverse-assembly prevention concave portion formed on the other side of the operation button hole and the operation button, into which the reverse-assembly prevention convex portion fits. (3) In the invention described in claim 3, the mobile terminal device described in claim 1 or claim 2 is provided, characterized in that the multiple operation buttons are formed in a shape such that the virtual area projected from the exterior side to the interior side of the mobile terminal device is the same. (4) In the invention as set forth in claim 4, there is provided the mobile terminal device as set forth in claim 3, characterized in that the plurality of reverse-assembly prevention structures are formed at different positions with respect to the virtual area. [Effects of the Invention]

[0008] According to the present invention, since the reverse assembly prevention structure is formed on each of the opposing surfaces of the plurality of operation button holes and the plurality of operation buttons, incorrect attachment during assembly of the operation buttons is prevented. This allows for minimalist and uniform buttons. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is an external configuration diagram of a mobile terminal device. [Figure 2] FIG. 1 is a perspective view of a mobile terminal device, focusing on its rear side; [Figure 3] 1A and 1B are explanatory diagrams showing a state in which a mobile terminal device is attached to a belt and a state in which the mobile terminal device is used. [Figure 4] 10A and 10B are explanatory diagrams of reverse assembly prevention structures provided on the side periphery and the operation button hole. [Figure 5] 10 is an exploded perspective view illustrating a procedure for attaching an operation button to an operation button hole in a side peripheral portion. FIG. [Figure 6] 10A and 10B are explanatory diagrams showing the state of the reverse assembly prevention structure depending on the mounting position and mounting direction of the operation button. [Figure 7]10A and 10B are explanatory diagrams illustrating a state of a reverse-assembly prevention structure in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] A preferred embodiment of the mobile terminal device 1 of the present invention will be described in detail below with reference to FIGS. The mobile terminal device 1 in this embodiment is a portable terminal device having at least two push buttons, and is applicable to various types of mobile terminal devices 1 such as wristwatch-type wearable terminals with various functions, smartphones, mobile phones, tablets, etc. In the following embodiment, a mobile terminal device 1 that is realized as a smart watch that not only has basic functions such as displaying the time but also acquires vital information of the user when worn on the wrist will be described as an example.

[0011] (1) Overview of the embodiment As shown in FIG. 1, the mobile terminal device 1 of this embodiment has a side periphery 2, a bottom surface 3, and a liquid crystal display device 4, and is equipped with an overall rounded cubic-shaped housing, two operation buttons 61 and 62, and various internal devices including a main board 75 (not shown) and a switch 751 that detects pushes by the operation buttons. Other internal devices include devices and components (liquid crystal display device, sensor unit, antenna, speaker, microphone, etc.) corresponding to various functions such as a clock function and a vital information measurement function provided in the mobile terminal device 1.

[0012] The side periphery 2 of the mobile terminal device 1 is formed with operation button holes 23 and 24 for arranging operation buttons 61 and 62 therein. For operation buttons 61 and 62, if the surface opposite to the part that appears on the exterior of the mobile terminal device 1 or the side peripheral portion 2 (the surface viewed in the -X direction) (the back surface viewed in the X direction) is defined as the first surface, and the surface facing the first surface at operation button holes 23 and 24 of the side peripheral portion 2 is defined as the second surface, then a reverse-assembly prevention structure Bk1 for operation button 61 and a reverse-assembly prevention structure Bk2 for operation button 62 are formed on the opposing first and second surfaces.

[0013] The reverse-assembly prevention structures Bk1 and Bk2 have a convex portion formed on one of the first and second surfaces, and a concave portion formed on the other surface into which the convex portion fits. The reverse-assembly prevention structures Bk1 and Bk2 are formed in positions where they do not overlap when projected onto a virtual area of ​​the same shape as the first surface. Therefore, even if an attempt is made to assemble the operation button 61 and the operation button 62 by mistake, the recessed and protruding portions will not engage, and the buttons will rise up in an incorrect position, making it possible to detect incorrect assembly. Since the reverse assembly prevention structure Bk1 and the reverse assembly prevention structure Bk2 are formed at a position where they do not overlap, i.e., at a position other than the center of gravity of the virtual area, even if an attempt is made to assemble the button with the top / bottom or left / right orientation incorrect, the error can be detected because the button will float up in an incorrect state. Furthermore, the reverse assembly prevention structures Bk1 and Bk2 are formed on the first and second surfaces that face each other, so that the operation buttons 61 and 62 that form part of the external configuration of the mobile terminal device 1 can be made into a mobile terminal device 1 with a minimalist and unified design.

[0014] (2) Details of the embodiment 1A to 1C show a mobile terminal device 1, in which (a) is a plan view, (b) is a front view, and (c) is a right side view. As shown in FIG. 1, the mobile terminal device 1 is formed into a thin cube shape by a side periphery 2, a bottom surface 3, and a liquid crystal display device 4 as a housing. The mobile terminal device 1 has five faces curved outward except for the cubic liquid crystal display device 4, and the intersections of the five faces are rounded, giving the device an overall rounded appearance. In the following description, as shown in FIG. 1, the thickness direction of the mobile terminal device 1 is referred to as the Z direction, the width direction as the X direction, and the length direction as the Y direction. In accordance with the orientation of the clock face, when viewed in a plane, the right side (+X side) is referred to as the 3 o'clock side, the left side (-X side) as the 9 o'clock side, the upper side (+Y side) as the 12 o'clock side, and the lower side (-Y side) as the 6 o'clock side.

[0015] The side periphery 2 constitutes the side periphery of the mobile terminal device 1, and has a sound hole 21, a sound collection hole 22, and operation button holes 23 and 24 formed therein, which penetrate the side periphery 2 in the thickness direction. Although the peripheral side portion 2 in this embodiment is made of a resin material, it can also be made of a metal material such as stainless steel or titanium, or ceramics.

[0016] The sound hole 21 is a through hole for outputting sound from a speaker 8 (see FIG. 4) disposed inside the mobile terminal device 1, which will be described later, to the outside. 1(b), the sound hole 21 of this embodiment is formed on the 6 o'clock side (-Y side) surface of the side peripheral portion 2. As a result, the sound emitted from the sound hole 21 is directed toward the wearer of the mobile terminal device 1, making it easier for the wearer to hear the sound. The sound hole 21 is formed in an elliptical shape with a width equal to or greater than the size of the speaker 8, particularly the width (width in the X direction) of the speaker 8. The sound hole 21 in this embodiment is formed at approximately the center in the X direction and the center in the Z direction on the 6 o'clock side surface of the side periphery 2, in accordance with the position of the speaker 8 (see Figure 4) placed inside. However, depending on the position where the speaker 8 is disposed, it may be disposed so as to be shifted in either the Z direction or the X direction from the center with respect to the surface on the 6 o'clock side of the side periphery 2 .

[0017] The sound collection hole 22 is a through hole for collecting sounds such as voices by a microphone (not shown) disposed in the mobile terminal device 1 . This sound collection hole 22 is formed on the 12 o'clock side opposite to the sound hole 21 so that the microphone does not pick up the sound output from the sound hole 21. Sound collection hole 22 is arranged on the +X side of the center in the X direction so that it can be brought closer to the face (mouth) when mobile terminal device 1 is worn on the left hand and brought closer to the face with a bent elbow. The internal microphone is also arranged on the +X side in line with sound collection hole 22.

[0018] 1, the operation button holes 23, 24 are holes for exposing the surfaces of the operation buttons 61, 62 for performing various operations on the mobile terminal device 1 to the outside of the side peripheral portion 2, and are formed in two places on the side surface on the 3 o'clock side. As will be described later in FIG. 4, the operation button holes 23, 24 are formed in a concave shape with a bottom 239, and their central portions are penetrated. The operation button holes 23, 24 are formed so that the shape of the outer periphery of the side periphery projected onto the side periphery 2 is the same, taking into consideration convenience when attaching the operation buttons 61, 62, design, and minimalism, and the operation button holes 23, 24 also have the same shape. Details will be described later, but the pair of operation button hole 23 and operation button 61, and the pair of operation button hole 24 and operation button 62 are each formed with reverse assembly prevention structures Bk1 and Bk2 to prevent the operation buttons 61 and 62 from being installed in the wrong position or orientation when assembling them.

[0019] The operation buttons 61 and 62 can be assigned in accordance with various functions that the mobile terminal device 1 has. The operation button 61 disposed in the operation button hole 23 functions as a power button that turns on and off the power of the mobile terminal device 1 when pressed and held, and has a button mark representing the power displayed on its outer surface. Note that the operation button 61 also functions as a button that returns the display screen of the liquid crystal display device 4 (see FIG. 3) to the home screen when pressed for a short time while the power is on. On the other hand, the operation button 62 disposed in the operation button hole 24 is an SOS button to be pressed in an emergency, and has the letters "SOS" printed on its outer surface. As shown in FIG. 1(a), the operation button 61 protrudes outward from the peripheral surface of the side peripheral portion 2, whereas the surface of the operation button 62 is located flush with or inside the peripheral surface of the side peripheral portion 2, since it is a button to be used in an emergency.

[0020] FIG. 2 is a perspective view of the mobile terminal device 1, mainly showing its rear side. FIG. 3 is an explanatory diagram showing the mobile terminal device 1 in a state where the belt 9 is attached and in a state where the mobile terminal device 1 is in use. The bottom surface portion 3 is the surface of the mobile terminal device 1 that comes into contact with the wrist H (see FIG. 3(b)), and is formed as a separate body from the same material as the peripheral side portion 2. However, the peripheral side portion 2 and the bottom surface portion 3 can also be formed integrally. As shown in Figures 1 and 2, two pairs of belt attachment portions 51a, 51b, 52a, 52b, a curved recess 31, a through hole for the charging portion 71, a through hole for the sensor portion 72, and a screw recess 32 are formed.

[0021] The belt attachment portions 51a, 51b, 52a, and 52b are members for attaching a belt 9 (see FIG. 3) to the mobile terminal device 1, and are formed integrally with the bottom surface portion 3 using the same material. A pair of belt attachment portions 51a, 51b are formed on the 6 o'clock side of the bottom surface portion 3 in the Y direction, and a pair of belt attachment portions 52a, 52b are formed on the 12 o'clock side. A bottomed pin hole 51c is formed on the opposing side of each of the belt attachment portions 51a, 51b, and a bottomed pin hole 52c is formed on the opposing side of each of the belt attachment portions 52a, 52b. The pin hole 51c is a hole for pinning the adapter 93 of the belt 9, and the pin hole 52c is a hole for pinning the fixed part 92 of the belt 9 (see FIG. 3). Although the pin holes 51c and 52c in this embodiment are bottomed holes, they may also be formed as through holes.

[0022] The curved recess 31 is a curved recess formed between a pair of belt mounting portions 51a, 51b and between a pair of belt mounting portions 52a, 52b to prevent the fixing portion 92 of the attached belt 9 from getting caught.

[0023] 2, an opening for charging unit 71 is formed near belt attachment parts 51a and 51b of bottom surface part 3, and charging terminals of charging unit 71 are exposed through this opening. Charging unit 71 is a member for charging a battery housed inside mobile terminal device 1. In addition, an opening for a sensor unit 72 that detects vital information (biological information) of a user wearing the mobile terminal device 1 is formed in approximately the center of the bottom surface portion 3, and a part of the sensor unit 72 is positioned so as to protrude from this opening. The sensor unit 72 is provided with a sensor corresponding to the vital sign detection function of the mobile terminal device 1, and is provided with at least one of various sensors that detect vital sign information such as the user's heart rate, pulse wave, respiratory rate, blood pressure, blood oxygen concentration (SpO2), body temperature, etc. by coming into close contact with the user's skin (wrist H) (see Figure 3(b)).

[0024] The screw-fastening recesses 32 are formed at four locations in total: on both outer sides of the pair of belt attachment portions 51a, 51b and on both outer sides of the pair of belt attachment portions 52a, 52b. Each screw-retaining recess 32 has a through-hole formed in its center, and the bottom surface portion 3 is screwed to the side peripheral portion 2 with a set screw 33. The screw-retaining recess 32 is a recess that hides the head of the set screw 33 used for fixing. By forming the screw-fastening recess 32 nearby, the bottom surface portion 3 is fixed to the side peripheral portion 2 with a set screw 33 at a position just outside the belt attachment portions 51a, 51b, 52a, and 52b, thereby increasing the strength of the belt attachment portions 51a, 51b, 52a, and 52b.

[0025] A main board 75 is disposed inside the mobile terminal device 1 (see FIG. 4). The main board 75 is equipped with a control unit consisting of a CPU, ROM, RAM, memory device, etc., as well as elements and devices corresponding to each function, which are elements for realizing various functions and information processing that the mobile terminal device 1 has, such as an audio output function, a function for acquiring vital information, a clock function, a communication function, a screen display function, etc. For example, by executing the vital information program, the CPU calculates vital information such as heart rate and blood oxygen concentration from data detected by the sensor unit 72, displays it on the liquid crystal display device 4, transmits it to an external device via the communication unit, and receives instructions from the external device.

[0026] Next, the reverse assembly prevention structure formed on the side periphery 2 of the mobile terminal device 1 and the operation buttons 61 and 62 will be described. Figure 4 is an explanatory diagram of the reverse assembly prevention structures Bk1 and Bk2 arranged in the side peripheral portion 2 and the operation button holes 23 and 24, where Figure 4(a) is a cross-sectional view of the side peripheral portion 2 along line AA in Figure 1(c) with operation buttons 61 and 62 attached, and Figure 4(b) is an enlarged view of the area around operation button 61. As shown in Figure 4(a), two operation buttons 61 and 62 are incorporated into the +X side surface of the side periphery 2, and the operation buttons 61 and 62 and the side periphery 2 are formed with reverse assembly prevention structures Bk1 and Bk2 to prevent incorrect assembly. In other words, the reverse assembly prevention structures Bk1 and Bk2 are formed on the first and second surfaces of the operation buttons 61 and 62, when the surface opposite to the external surface (surface viewed in the -X direction) that appears as the appearance of the side peripheral portion 2 is defined as the first surface, and the surface of the side peripheral portion 2 that faces this first surface is defined as the second surface.

[0027] The operation button 61 and the operation button 62 are formed so that their shapes when projected in the -X direction are the same, and reverse-assembly prevention structures Bk1 and Bk2 are formed at different positions relative to the virtual area onto which the shapes are projected. Specifically, shaft axes 612 and 622 are formed in the center of operation button 61 and operation button 62, respectively, and reverse assembly prevention structure Bk1 for operation button 61 is formed on the +Y side of shaft axis 612, and reverse assembly prevention structure Bk2 for operation button 62 is formed on the -Y side of shaft axis 622.

[0028] The configurations around the operation buttons 61 and 62 are identical except for the positions of the reverse-assembly prevention structures Bk1 and Bk2 relative to the virtual area, so the operation button 61 will be described as an example. FIG. 4(b) is an enlarged view of the area around the operation button 61 indicated by the dotted circle in FIG. 4(a). As shown in FIG. 4(b), the operation button hole 23 is formed in a concave shape to form a bottom portion 239 that corresponds to the second surface, and a shaft hole 233 is formed through the center of the bottom portion 239. A reverse-assembly prevention protrusion 231 that functions as a part of the reverse-assembly prevention structure Bk1 is formed on the +Y side of a shaft hole 233 formed in the center of the second surface. In addition, spring recesses 232 are formed in the bottom portion 239 at positions equidistant in the +Y and −Y directions from the shaft hole 233. These two spring recesses 232 are recesses for inserting compression springs 614 that push back the operation button 61 outward when pressed by the user.

[0029] On the other hand, a shaft axis 612 is formed in the center of a first surface (inner surface) of the operation button 61 facing the bottom portion 239. A waterproof O-ring 613 is disposed at approximately the center of the shaft 612 in the axial direction (X direction). In addition, an E washer 615 that functions as a stopper is arranged on the shaft axis 612 at a position where its tip end passes through the shaft hole 233 to prevent the operation button 61 from coming off the operation button hole 23 by the compression spring 614.

[0030] A reverse-assembly prevention recess 611 that functions as a reverse-assembly prevention structure Bk1 together with the reverse-assembly prevention protrusion 231 is formed on the first surface of the operation button 61 at a position facing the reverse-assembly prevention protrusion 231 in the +Y direction of the shaft axis 612. As shown in FIG. 4(b), the operation button 61 and the bottom surface of the operation button hole 23 are subjected to a force by the compression spring 614 in a direction that moves them away from each other, and the E washer 615 abuts against the side peripheral portion 2, so that the first surface and the second surface, and the tip of the reverse-assembly prevention protrusion 231 and the bottom of the reverse-assembly prevention recess 611 are positioned a predetermined distance apart. By moving away from the operation button 61 by this predetermined distance, the operation button 61 can be pressed in the -X direction.

[0031] A switch 751 is disposed on the inside of the side periphery 2 to detect input by pressing the operation button 61 and transmit the detected input to the main board 75. The switch 751 may be, for example, a board-mounted tactile switch or a membrane switch using a metal dome. A contact protrusion 752 is formed on the +X side of the switch 751. A gap is provided between the tip of the contact protrusion 752 and the tip of the shaft axis 612 to prevent malfunction.

[0032] Next, a procedure for attaching the operation buttons 61 and 62 to the operation button holes 23 and 24 will be described. 5 is an exploded perspective view showing the procedure for attaching the operation buttons 61, 62 to the operation button holes 23, 24 of the side periphery 2. In FIG. 5, the bottom of the drawing is the +Z direction, and the opposite side to FIG. 4 is shown. (a) First, two compression springs 614, 624 are inserted into the spring recesses 232, 242 formed in the operation button holes 23, 24 of the side periphery 2, respectively, and fixed therein. (b) At the same time, O-rings 613 and 623 are attached to the shafts 612 and 622 of the operation buttons 61 and 62. (c) Next, while pressing the compression springs 614, 624, the operation buttons 61, 62 are fitted into the operation button holes 23, 24 until the tips of the shafts 612, 622 pass through the shaft holes 233, 243. (d) Finally, E washers 615 and 625 are fitted onto the tip ends of the shafts 612 and 622 that have passed through the shaft holes 233 and 243 from the inside of the side circumferential portion 2 .

[0033] The assembly procedure described above is for the case where the operation buttons 61 and 62 are attached in the correct positions and orientations. Next, the mounting positions of the operation buttons 61 and 62 and the case where they are mounted upside down will be described. FIG. 6 shows the state of reverse assembly prevention structures Bk1 and Bk2 depending on the mounting position and mounting direction of operation buttons 61 and 62.

[0034] 6(a) is a view of the mobile terminal device 1 seen from the side of the operation buttons 61 and 62, and FIGS. 6(b) to 6(e) show the states of reverse assembly prevention structures Bk1 and Bk2 depending on the orientation of the operation buttons 61 and 62. In Figures 6(b) to (e), the positions of the reverse-assembly prevention recesses 611, 621 formed in each operation button 61, 62 that make up the reverse-assembly prevention structures Bk1, Bk2 are indicated by black squares, and the positions of the reverse-assembly prevention protrusions 231, 241 in the operation button holes 23, 24 are indicated by white squares. Figure 6(b) shows the case where the operation buttons 61, 62 are attached in the correct position and orientation as explained in Figure 5. Therefore, the reverse-assembly prevention protrusions 231, 241 fit into the reverse-assembly prevention recesses 611, 621, allowing the operation buttons 61, 62 to be inserted to the correct positions for assembly.

[0035] On the other hand, in Figure 6(c), the installation positions of the operation buttons 61 and 62 are correct in the operation button holes 23 and 24, but the top and bottom in the Z direction are reversed, so the uneven shapes of the reverse-assembly prevention structures Bk1 and Bk2 do not mesh during the assembly process, and the tips of the reverse-assembly prevention convex portions 231 and 241 hit the first surfaces of the operation buttons 61 and 62, causing the operation buttons 61 and 62 to float up, and the worker can recognize the assembly error. Furthermore, as shown in Figures 6(d) and (e), if the mounting positions of the operation buttons 61 and 62 are reversed to the operation button holes 23 and 24, the operation buttons 61 and 62 will float up, as in Figure 6(c), regardless of whether the mounting direction is correct (d) or incorrect (e), and the assembly error can be recognized.

[0036] As described above, according to the mobile terminal device 1 of this embodiment, the reverse assembly prevention structures Bk1, Bk2 are formed with uneven shapes on the first and second surfaces of the operation buttons 61, 62 and their operation button holes 23, 24, which face each other. When projected onto a virtual area having the same shape as the first surfaces of the operation buttons 61 and 62, the reverse assembly prevention structures Bk1 and Bk2 are formed at positions where they do not overlap each other. Therefore, if the operation buttons 61, 62 are reversed or turned upside down, the reverse-assembly prevention convex portions 231, 241 will not fit into the reverse-assembly prevention concave portions 611, 621 and will come into contact with the first surface, causing the operation buttons 61, 62 to float up. This allows the worker to immediately recognize any incorrect position or orientation during assembly.

[0037] In this way, the reverse assembly prevention structures Bk1, Bk2 that prevent incorrect assembly are formed on the first and second surfaces that face each other, so that the operation buttons 61, 62 that form part of the external configuration of the mobile terminal device 1 have a minimalist and unified design. Furthermore, the outer peripheral shape (outline shape) and surface color of the portions of the operation buttons 61 and 62 exposed from the side periphery 2 can be made the same. Furthermore, since any errors in position or orientation can be immediately checked before the assembly of the operation buttons 61, 62 is completed, the manufacturing time of the mobile terminal device 1 can be further shortened.

[0038] The above describes a mobile terminal device 1, which is one embodiment of the present invention. However, the present invention is not limited to the described embodiment, and various modifications can be made within the scope, embodiments, and modified examples set forth in the claims. For example, in the described embodiment, the reverse-assembly prevention structure Bk1 is located on the +Y side of the shaft axis 612 formed in the center of the first surface, and the reverse-assembly prevention structure Bk2 is located on the -Y side of the shaft axis 622 formed in the center of the first surface. On the other hand, as shown in FIG. 7, it is also possible to arrange the reverse-assembly prevention structure Bk1 on the -Y side from the center of the first surface, and the reverse-assembly prevention structure Bk2 on the +Y side from the center of the first surface.

[0039] 7(a) to 7(d) correspond to the states of FIGS. 6(b) to 6(e) described in this embodiment. As shown in FIG. 7(a), when the operation buttons 61 and 62 are attached in the correct position and orientation, the operation buttons 61 and 62 can be inserted to the correct position for assembly. On the other hand, as shown in Figure 7(b), if the installation positions of the operation buttons 61 and 62 are correct but the operation buttons 61 and 62 are upside down in the Z direction, the operation buttons 61 and 62 will float up, making it possible to recognize the assembly error. Furthermore, as shown in Figures 7(c) and (d), even if the attachment positions of the operation buttons 61 and 62 are reversed to the operation button holes 23 and 24, the operation buttons 61 and 62 will rise up, making it possible to recognize an assembly error.

[0040] In addition, in the described embodiment and modified example (Figure 7), the reverse-assembly prevention convex portions 231, 241 are formed on the second surface side of the side peripheral portion 2, and the reverse-assembly prevention concave portions 611, 621 are formed on the first surface side of the operation buttons 61, 62, but the convex and concave portions may be formed in the opposite direction.

[0041] In this embodiment, two operation button holes 23, 24 are formed on the 3 o'clock side of the side periphery 2 to match the operation buttons 61, 62, but more operation buttons and operation button holes may be formed. In this case, all of them may be formed and arranged on the 3 o'clock side of the side periphery 2, or some or all of them may be formed and arranged on the opposite 9 o'clock side. When three or more operation buttons are provided, all of the operation buttons and their operation button holes are provided with any of the reverse assembly prevention structures Bk described in the embodiment or modified example. [Explanation of symbols]

[0042] 1. Mobile terminal device 2 Side circumference 21 sound hole 22 Sound collection hole 23, 24 Operation button holes 231, 241 Reverse assembly prevention protrusion 232, 242 Spring recess 233, 243 shaft holes 239 Bottom 3 Bottom part 31 curved recess 32 Screw recess 33 Set screw 4 LCD display device 51a, 51b Belt attachment parts 52a, 52b Belt attachment parts 51c, 52c pin holes 61 Operation button (power button) 62 Operation button (SOS button) 611, 621 Reverse assembly prevention recess 612, 622 Shaft axis 613, 623 O-ring 614, 624 Compression spring 615, 625 E Washer 71 Live parts 72 Sensor section 75 Main board 751 Switch 752 Contact protrusion 8 speakers 9 Belt 92 Fixed part 93 Adapter Bk1, Bk2 reverse assembly prevention structure H Wrist

Claims

1. a housing having a side periphery, a bottom surface, and a liquid crystal display device disposed on the side periphery facing the bottom surface; a plurality of operation buttons disposed on the side periphery; a switch disposed within the housing and configured to detect pressing of the operation button; a plurality of operation button holes formed in the side periphery, into which the operation buttons are inserted; a plurality of reverse-assembly prevention structures formed on opposing surfaces of the plurality of operation button holes and the plurality of operation buttons; A mobile terminal device comprising:

2. Each of the plurality of reverse assembly prevention structures is a reverse-assembly prevention protrusion formed on one side of the operation button hole and the operation button and protruding toward the other side; a reverse-assembly prevention recess formed on the other side of the operation button hole and the operation button, into which the reverse-assembly prevention protrusion is fitted; 2. The mobile terminal device according to claim 1, further comprising:

3. The plurality of operation buttons are formed in a shape such that the virtual areas projected from the exterior side of the mobile terminal device to the interior side are the same.

3. The mobile terminal device according to claim 1 or 2.

4. the plurality of reverse-assembly prevention structures are formed at different positions with respect to the virtual area, 4. The mobile terminal device according to claim 3.

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