Electronic device having a waterproof structure

TECHNICAL FIELD

The present invention relates to an electronic device which has a waterproof structure and includes an operation button disposed on the side part of a main body.

BACKGROUND ART

In this type of electronic device, a pair of cover panels is disposed to cover the front face and the back face of a main body having a waterproof structure. The main body comprises a pair of body chassis joined together. A switch unit on which a tact switch is mounted is disposed on the side part of the main body. An operation button for pressing the tact switch of the switch unit is held between the pair of cover panels.

In such an electronic device, a through hole for allowing a pusher of the operation button to pass therethrough is formed on the side part of the main body. To avoid water to enter the inside of the main body through the through hole, a waterproof structure is required.

In an assembling process of an electronic device in which an operation button is disposed on the side part of a main body, the main body is assembled in the following manner. A switch unit is first housed inside a housing recess formed on one body chassis. The switch unit is then fixed inside the housing recess with an adhesive tape. Thereafter, the other body chassis is joined to the above body chassis. In this state, a pair of cover panels is attached to cover the front face and the back face of the main body.

Since the switch unit is required to be fixed inside the housing recess with an adhesive tape, not only the number of components is increased, but also the number of assembling steps may be increased.

Therefore, a reduction in the number of components or the number of assembling steps has been required in an electronic device which has a waterproof structure and includes an operation button disposed on the side part of a main body.

SUMMARY OF THE INVENTION

An electronic device having a waterproof structure according to the present invention comprises a main body having a waterproof structure, the main body including a built-in electronic component and a pair of body chassis joined together, a pair of cover panels disposed to cover a front face and a back face of the main body, a switch unit disposed on a side part of the main body, the switch unit including a contact, an operation button held between the pair of cover panels, the operation button having a pusher for pressing the contact of the switch unit, the pusher projecting from the operation button, a housing recess formed on at least one of the body chassis, the housing recess being recessed on a joint surface with the other body chassis to form a housing chamber for the switch unit, a through hole penetrating the one body chassis from a side face toward the housing recess, and a bag-like waterproof packing member attached to the through hole, the waterproof packing member being recessed toward the switch unit to house the pusher of the operation button. The pusher of the operation button passes through the through hole toward the contact of the switch unit, and an end of the waterproof packing member is pressed against the switch unit to fixedly hold the switch unit inside the housing recess.

BRIEF DESCRIPTION OF THE DRAWINGS

<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Fig. 1</figref> is a perspective view illustrating the front face of an information terminal device which is an embodiment of the present invention.</li><li><figref idref="f0001">Fig. 2</figref> is a perspective view illustrating the back face of the information terminal device.</li><li><figref idref="f0002">Fig. 3</figref> is an exploded perspective view illustrating the configuration of the front side of the information terminal device.</li><li><figref idref="f0003">Fig. 4</figref> is an exploded perspective view illustrating the configuration of the back side of the information terminal device.</li><li><figref idref="f0004">Fig. 5</figref> is an exploded perspective view illustrating the configuration of the back side of the information terminal device upside down.</li><li><figref idref="f0005">Fig. 6</figref> is an exploded perspective view illustrating the configuration of the front side of the information terminal device upside down.</li><li><figref idref="f0006">Fig. 7</figref> is a perspective view of an operation button.</li><li><figref idref="f0006">Fig. 8</figref> is a perspective view of the operation bottom viewed from a different direction.</li><li><figref idref="f0006">Fig. 9</figref> is a perspective view of a waterproof packing member.</li><li><figref idref="f0007">Fig. 10</figref> is a perspective view of the waterproof packing member viewed from a different direction.</li><li><figref idref="f0007">Fig. 11</figref> is a perspective view of a switch unit.</li><li><figref idref="f0007">Fig. 12</figref> is a perspective view of the switch unit viewed from a different direction.</li><li><figref idref="f0008">Fig. 13</figref> is a perspective view illustrating a first step of an assembling process.</li><li><figref idref="f0008">Fig. 14</figref> is a perspective view illustrating the first step upside down.</li><li><figref idref="f0009">Fig. 15</figref> is a cross-sectional view taken along line X-X of <figref idref="f0008">Fig. 14</figref>.</li><li><figref idref="f0009">Fig. 16</figref> is an enlarged cross-sectional view of a part A of <figref idref="f0009">Fig. 15</figref>.</li><li><figref idref="f0010">Fig. 17</figref> is a perspective view illustrating a second step of the assembling process.</li><li><figref idref="f0010">Fig. 18</figref> is a perspective view illustrating the second step upside down.</li><li><figref idref="f0011">Fig. 19</figref> is a cross-sectional view taken along line X-X of <figref idref="f0010">Fig. 18</figref>.</li><li><figref idref="f0011">Fig. 20</figref> is an enlarged cross-sectional view of a part B of <figref idref="f0011">Fig. 19</figref>.</li><li><figref idref="f0012">Fig. 21</figref> is a perspective view illustrating a third step of the assembling process.</li><li><figref idref="f0012">Fig. 22</figref> is a perspective view illustrating the third step upside down.</li><li><figref idref="f0013">Fig. 23</figref> is a cross-sectional view taken along line X-X of <figref idref="f0012">Fig. 22</figref>.</li><li><figref idref="f0013">Fig. 24</figref> is an enlarged cross-sectional view of a part C of <figref idref="f0013">Fig. 23</figref>.</li><li><figref idref="f0014">Fig. 25</figref> is a perspective view illustrating a fourth step of the assembling process.</li><li><figref idref="f0014">Fig. 26</figref> is a perspective view illustrating the fourth step upside down.</li><li><figref idref="f0015">Fig. 27</figref> is a cross-sectional view taken along line X-X of <figref idref="f0014">Fig. 26</figref>.</li><li><figref idref="f0015">Fig. 28</figref> is an enlarged cross-sectional view of a part D of <figref idref="f0015">Fig. 27</figref>.</li><li><figref idref="f0016">Fig. 29</figref> is a perspective view illustrating a fifth step of the assembling process.</li><li><figref idref="f0016">Fig. 30</figref> is a perspective view illustrating the fifth step upside down.</li><li><figref idref="f0017">Fig. 31</figref> is a cross-sectional view taken along line X-X of <figref idref="f0016">Fig. 30</figref>.</li><li><figref idref="f0017">Fig. 32</figref> is an enlarged cross-sectional view of a part E of <figref idref="f0017">Fig. 31</figref>.</li><li><figref idref="f0018">Fig. 33</figref> is a cross-sectional view illustrating a principal part of <figref idref="f0017">Fig. 32</figref> in a further enlarged manner.</li></ul>

DETAILED DESCRIPTION OF EMBODIMENT

Hereinbelow, an embodiment in which the present invention is embodied as an information terminal device will be specifically described with reference to the drawings.

As illustrated in <figref idref="f0001">Figs. 1 and 2</figref>, an information terminal device as an embodiment of the present invention comprises a flat rectangular parallelepiped main body 1 which includes a display 10 and an electronic circuit both built therein. The front face of the main body 1 is covered with a front cover panel 3 made of a synthetic resin. The back face of the main body 1 is covered with a back cover panel 5 made of a synthetic resin. A screen of the display 10 is exposed from the front face of the main body 1. A plurality of operation buttons 7 are disposed on the side face of the main body 1. A cover body 6 is attached to the back face of the main body 1.

As illustrated in <figref idref="f0002 f0003 f0004 f0005">Figs. 3 to 6</figref>, the main body 1 is formed by joining a front body chassis 2 and a back body chassis 4 together. An O-ring 11 is interposed between the front body chassis 2 and the back body chassis 4 to achieve waterproofing for the main body 1.

The front cover panel 3 is attached to the front body chassis 2 by a hook mechanism. The back body chassis 4 is attached to the back cover panel 5 by a hook mechanism.

A peripheral wall 40 which surrounds a battery housing chamber is formed on the back body chassis 4. The battery housing chamber is liquid-tightly closed by the cover body 6.

As illustrated in <figref idref="f0002">Figs. 3</figref> and <figref idref="f0005">6</figref>, a plurality of switch units 9 are disposed on the side part of the front body chassis 2. As illustrated in <figref idref="f0007">Figs. 11 and 12</figref>, each of the switch units 9 includes a flexible substrate 91 and one or a plurality of tact switches 92 mounted on the surface of the flexible substrate 91.

As illustrated in <figref idref="f0002">Figs. 3</figref> and <figref idref="f0005">6</figref>, a plurality of operation buttons 7 for pressing the tact switches 92 of the switch units 9 are disposed on the side part of the front body chassis 2. As illustrated in <figref idref="f0006">Figs. 7 and 8</figref>, each of the operation buttons 7 comprises a head 71 to be an operation target, a pusher 73 which projects from the back face of the head 71, and a rib 72 which extends from the outer peripheral face of the head 71 in a direction perpendicular to the projection direction of the pusher 73.

Based on a posture with the display 10 of the main body 1 facing downward as illustrated in <figref idref="f0005">Fig. 6</figref>, the rib 72 of the operation button 7 includes a first rib portion 72a which projects downward, a second rib portion 72b which projects upward, and a third rib portion 72c and a fourth rib portion 72d which project rightward and leftward as illustrated in <figref idref="f0006">Figs. 7 and 8</figref>.

The second rib portion 72b, the third rib portion 72c, and the fourth rib portion 72d of the rib 72 are formed to have a projection amount sufficient to obtain a reliable holding power when held between the cover panels 3, 5 in the end. On the other hand, as illustrated in <figref idref="f0018">Fig. 33</figref>, a projection amount W1 of the first rib portion 72a is set to be smaller than a projection amount W2 of the second rib portion 72b.

As illustrated in <figref idref="f0002">Fig. 3</figref>, through holes 20 are formed on a side wall of the front body chassis 2. Each of the through holes 20 is used for allowing the pusher 73 of each of the operation buttons 7 to pass therethrough toward the tact switch 92 of each of the switch units 9.

Waterproof packing members 8 for sealing the through holes 20, the waterproof packing members 8 being made of silicone rubber, are attached to the respective through holes 20. As illustrated in <figref idref="f0006">Figs. 9</figref> and <figref idref="f0007">10</figref>, each of the waterproof packing members 8 is formed in a bottomed bag-like shape as a whole. Further, the waterproof packing member 8 comprises a flat plate portion 81 which has a central hole, a cylindrical peripheral wall 82 which projects from the central part of the flat plate portion 81, and a bottom wall 83 which closes a projection end of the peripheral wall 82. The pusher 73 of the operation button 7 is housed inside the peripheral wall 82.

In the information terminal device, as illustrated in <figref idref="f0017">Figs. 32</figref> and <figref idref="f0018">33</figref>, a housing recess 21 is formed on the front body chassis 2 and a housing recess 41 is formed on the back body chassis 4 in a facing part in which the side wall of the front body chassis 2 and the side wall of the back body chassis 4 face each other. The housing recesses 21, 41 form a housing chamber for the switch unit 9.

The tip face of the bottom wall 83 of the waterproof packing member 8 is pressed against the surface of the tact switch 92 of the switch unit 9 inside the housing chamber. In this state, the switch unit 9 is fixedly held inside the housing recess 21 by an elastic repulsive force of the waterproof packing member 8.

When the bottom wall 83 of the waterproof packing member 8 is pressed against the surface of the tact switch 92 of the switch unit 9 in an assembled state in which the waterproof packing member 8 is inserted into the through hole 20 of the front body chassis 2 as illustrated in <figref idref="f0018">Fig. 33</figref>, a predetermined elastic deformation amount S (e. g. , 0. 025 mm to 0. 05 mm) is generated in the waterproof packing member 8. The positional relationship between the waterproof packing member 8 and the switch unit 9 is designed in order for the tact switch 92 not to be turned on by the elastic repulsive force of the waterproof member 8.

A small clearance is set between the outer peripheral face of the pusher 73 of the operation button 7 and the inner peripheral face of the waterproof packing member 8. Further, an extremely small clearance of 0 or more is set between the tip face of the pusher 73 of the operation button 7 and the bottom wall 83 of the waterproof packing member 8.

The front cover panel 3 is attached to the front body chassis 2. The back cover panel 5 is attached to the back body chassis 4. Accordingly, in a facing part in which the front body chassis 2 and the front cover panel 3 face the back body chassis 4 and the back cover panel 5, a first groove 13 which extends across the front body chassis 2 and the front cover panel 3 and a second groove 14 which extends across the back body chassis 4 and the back cover panel 5 are formed.

The first rib portion 72a of the operation button 7 is inserted into the first groove 13 and the second rib portion 72b of the operation button 7 is inserted into the second groove 14 so that the operation button 7 is held between the cover panels 3, 5.

In this state, the second rib portion 72b of the operation button 7 is deeply inserted into the second groove 14 with a sufficient projection amount. As a result, there is almost no likelihood that the operation button 7 comes off the first groove 13 and the second groove 14.

In the information terminal device, waterproofing for the main body 1 is achieved by the O-ring 11 interposed between the front body chassis 2 and the back body chassis 4 and the waterproof packing members 8 attached to the through holes 20 of the front body chassis 2.

When the operation button 7 is depressed, the waterproof packing 8 is elastically deformed. Accordingly, the pusher 73 of the operation button 7 presses the tact switch 92 of the switch unit 9 to turn on the tact switch 92, thereby generating various operation signals.

<figref idref="f0008 f0009 f0010 f0011 f0012 f0013 f0014 f0015 f0016 f0017">Figs. 13 to 32</figref> illustrate an assembling process of the information terminal device.

As illustrated in <figref idref="f0008 f0009">Figs. 13 to 16</figref>, in a first step of the assembling process, the front body chassis 2 and the back body chassis 4 are joined together to assemble the main body 1 which includes the display 10 and the electronic circuit both built therein.

Further, as illustrated in <figref idref="f0009">Fig. 16</figref>, the switch unit 9 is housed in the housing chamber formed by the housing recess 21 of the front body chassis 2 and the housing recess 41 of the back body chassis 4. The waterproof packing member 8 is attached to each of the through holes 20 of the front body chassis 2.

When the switch unit 9 is housed in the housing chamber, the switch unit 9 is first inserted into the housing recess 21 with the front body chassis 2 maintained in a posture with the housing recess 21 facing upward. Accordingly, the switch unit 9 is held inside the housing recess 21 of the front body chassis 2. Thus, it is not necessary to fix the switch unit 9 with, for example, an adhesive tape.

Then, the back body chassis 4 is joined to the front body chassis 2 to assemble the main body 1 to thereby house the end of the switch unit 9 in the housing recess 41 of the back body chassis 4.

As illustrated in <figref idref="f0010 f0011">Figs. 17 to 20</figref>, in a second step of the assembling process, the front cover panel 3 is attached to the front body chassis 2.

Accordingly, as illustrated in <figref idref="f0011">Fig. 20</figref>, the first groove 13 which is open upward is formed between the side wall of the front body chassis 2 and the side wall of the front cover panel 3.

As illustrated in <figref idref="f0012 f0013">Figs. 21 to 24</figref>, in a third step of the assembling process, the plurality of operation buttons 7 are attached in a posture with the front body chassis 2 facing downward and the back body chassis 4 facing upward.

Specifically, as illustrated in <figref idref="f0013">Fig. 24</figref>, the pusher 73 of each of the operation buttons 7 is inserted into the corresponding waterproof packing member 8 and the first rib portion 72a is inserted into the first groove 13 with the operation button 7 slightly inclined. In a configuration in which the first rib portion 72a has the same projection amount as the second rib portion 72b, it is difficult to attach the operation buttons 7 in this manner.

As illustrated in <figref idref="f0014 f0015">Figs. 25 to 28</figref>, in a fourth step of the assembling process, a regular posture with the pusher 73 of each of the operation buttons 7 horizontally extending inside the corresponding waterproof packing member 8 is set.

In this state, each of the operation buttons 7 is held by the front body chassis 2 and the front cover panel 3. Thus, the operation button 7 will not drop off even if the hand is released from the operation button 7.

As illustrated in <figref idref="f0016 f0017">Figs. 29 to 32</figref>, in a fifth step of the assembling step, the back cover panel 5 is attached to the back body chassis 4 in a posture with the front body chassis 2 facing downward and the back body chassis 4 facing upward.

Accordingly, as illustrated in <figref idref="f0017">Fig. 32</figref>, the second rib portion 72b of each of the operation buttons 7 is housed inside the second groove 14 so that the operation button 7 is held between the front cover panel 3 and the back cover panel 5.

In the assembling process of the information terminal device, each of the operation buttons 7 can be inserted into and attached to the first groove 13 with only the front cover panel 3 attached to the main body 1 in the third step of the assembling process illustrated in <figref idref="f0012 f0013">Figs. 21 to 24</figref> and the fourth step of the assembling process illustrated in <figref idref="f0014 f0015">Figs. 25 to 28</figref>. Therefore, an operation of mounting the operation buttons 7 is extremely easy.

On the other hand, a conventional method employs an operation in which all the water proof packing members 8 are held by, for example, the hand or a jig with the pushers 73 of the operation buttons 7 inserted into the respective waterproof packing members 8 of the main body 1, and, in this state, the front cover panel 3 and the back cover panel 5 are attached to the main body 1. Therefore, an operation of mounting the operation buttons 7 is difficult.

The information terminal device according to the present invention makes it possible to reduce the number of components and the number of assembling steps and also facilitate the assembling process with a simple structure of merely slightly changing the positional relationship between the switch unit 9 and the waterproof packing 8 and slightly changing the projection amount of the rib 72 of the operation button 7.

The configurations of the respective members of the present invention are not limited to the above embodiment. A person skilled in the art may make various modifications without departing from the spirit of the invention described in the claims.

DESCRIPTION OF REFERENCE CHARACTERS

<dl id="dl0001" compact="compact"><dt>1</dt><dd>main body</dd><dt>13</dt><dd>first groove</dd><dt>14</dt><dd>second groove</dd><dt>2</dt><dd>front body chassis</dd><dt>3</dt><dd>front cover panel</dd><dt>4</dt><dd>back body chassis</dd><dt>5</dt><dd>back cover panel</dd><dt>21</dt><dd>housing recess</dd><dt>41</dt><dd>housing recess</dd><dt>6</dt><dd>cover body</dd><dt>10</dt><dd>display</dd><dt>7</dt><dd>operation button</dd><dt>72a</dt><dd>first rib portion</dd><dt>72b</dt><dd>second rib portion</dd><dt>73</dt><dd>pusher</dd><dt>8</dt><dd>waterproof packing member</dd><dt>9</dt><dd>switch unit</dd><dt>91</dt><dd>flexible substrate</dd><dt>92</dt><dd>tact switch</dd></dl>