Waterproof structure, electronic device, and method for manufacturing the waterproof structure

The disclosed device includes: housing which has opening; protective panel arranged in the housing and which closes opening; O ring which is arranged on one face of protective panel in a direction perpendicular to an opening plane of opening; sliding plate which is arranged on the other face of protective panel in a direction perpendicular to the opening plane of opening and which holds protective panel in such a way that protective panel can slide in a direction parallel to the opening plane of opening; and spring member which is arranged in the state of making contact with an end portion of protective panel and which supports protective panel in such a way that protective panel can be displaced in a direction parallel to the opening plane of opening. Protective panel is supported by housing in the state in which protective panel is sandwiched between O ring and sliding plate.

TECHNICAL FIELD

The present invention relates to a waterproof structure that is located at the opening of a casing of an electronic device, an electronic device having the waterproof structure, and a method for manufacturing the waterproof structure.

BACKGROUND ART

An electronic device such as a portable terminal having a display panel, generally, has a display panel arranged opposite to the opening of a housing and is constructed in such a way that the opening is closed by a protective panel. An electronic device like this has a waterproof structure in which the opening is hermetically closed by the protective panel. Constructions that are described in patent documents 1, 2, are example of this kind of waterproof structure that is publically known.

In recent years, in an electronic device having a touch panel for operating a display of a display panel, the display face of the display panel tends to be increased in size and the usage environment of a user is greatly changed as the size of the display face increases. For this reason, the cases where the electronic device gets wet or has an impact applied thereto have increased in number.

Further, as the size of the display face of the electronic device increases, the electronic device is limited by the kind of materials which can be combined for use in the electronic device according to the linear expansion coefficients of the materials of constituent members. Therefore, increasing the size of the display face of the electronic device makes it difficult to ensure adequate waterproof characteristics and durability. Hence, in the electronic device provided with a touch panel, in particular, are strongly requested improvements in the waterproof property and in the resistance to impact of the display face of the display panel.

A section view of an example of a waterproof structure relating to the present invention is shown inFIG. 1. As shown inFIG. 1, waterproof structure101relating to the present invention includes: a housing107having opening108; liquid crystal display panel110which is arranged opposite to opening108in the housing107; and protective panel111which is arranged outside housing107and which closes opening108. Protective panel111is arranged in such a way as to protect the display face of liquid display panel110.

Housing107is constructed of first outer case107aand second outer case107bwhich are engaged with each other. A portion in which first outer case107ais engaged with second outer case107bhas O ring113fitted therein and hence has airtightness ensured. Protective panel111is arranged on the outer side of first outer case107aand is bonded to the peripheral edge portion of opening108by double-sided adhesive tape116to thereby close opening108.

Patent document 1: Japanese Utility Model Application Laid-Open No. 58-78685

SUMMARY OF INVENTION

By the way, as described above, the waterproof structure relating to the present invention has the following problems.

The first problem is described as follows: respective constituent members are different from each other in a linear expansion coefficient and hence a change in temperature causes a change to the outside dimension of the protective panel and the housing, whereby the constituent members are shifted in position from each other in the state where different kinds of constituent members are fitted in and combined with each other. For this reason, in the case where the constituent members are greatly moved in position, an adhesive force of an adhesive member such as a double-sided adhesive tape cannot endure a force developed by the constituent member being moved in position and hence the adhesive member is broken, which presents the problem of impairing the waterproof property.

The second problem is described as follows: the protective panel is directly fixed to the opening of the housing by the adhesive member, so that the protective panel directly receives an impact applied thereto when the electronic device is dropped, thereby making it likely that the electronic device will break.

The third problem is described as follows: the protective panel in the waterproof structure described above is placed on the opening of the housing by the adhesive member, so that the center of an opposite face of the protective panel opposite to the liquid display panel is shifted from the center of the opening according to a variation in the position in which the protective panel is placed. As a result, the center of the display face of the liquid display panel is shifted from the center of the opposite face of the protective panel, which also presents the problem of causing faulty fabrication.

Hence, an object of the present invention is to provide a waterproof structure capable of solving any one of the relating technical problems described above and enhancing waterproof properties and enhancing resistance to impact, an electronic device having the waterproof structure, and a method for manufacturing the waterproof structure.

In order to achieve the object described above, a waterproof structure relating to the present invention includes: a housing which has an opening; a closing member which is arranged in the housing and which closes the opening; a waterproof member which is arranged on one face of the closing member in a direction perpendicular to an opening plane of the opening; a holding member which is arranged on the other face of the closing member in a direction perpendicular to the opening plane of the opening and which holds the closing member in such a way that the closing member can slide in a direction parallel to the opening plane of the opening; and an elastic member which is arranged such that it makes contact with an end portion of the closing member and which supports the closing member in such a way that the closing member can be displaced in a direction parallel to the opening plane of the opening. The closing member is supported by the housing in the state in which the closing member is sandwiched between the waterproof member and the holding member.

Further, an electronic device relating to the present invention includes a waterproof structure of the present invention.

Still further, a method for manufacturing a waterproof structure relating to the present invention includes the steps of: sandwiching a closing member, which is arranged in a housing and which closes an opening of the housing, between a waterproof member, which is arranged on one face of the closing member in a direction perpendicular to an opening plane of the opening, and a holding member, which is arranged on the other face of the closing member in a direction perpendicular to the opening plane of the opening; and holding the closing member by the holding member which made contact with an end portion of the closing member in such a way that the closing member can be displaced in a direction parallel to the opening plane of the opening.

According to the present invention, the closing member is movably supported by the holding member and the elastic member makes contact with the closing member, whereby waterproof properties can be enhanced and resistance to impact can be improved.

DESCRIPTION OF EMBODIMENTS

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

A perspective view of an electronic device of a first embodiment is shown inFIG. 2. A section view to show a main portion of a waterproof structure that the electronic device of the first embodiment has, is shown inFIG. 3.

As shown inFIG. 2andFIG. 3, the electronic device of the first embodiment has waterproof structure1for preventing liquid from coming into housing7from the outside thereof

As shown inFIG. 3, the waterproof structure1includes: housing7having opening8; liquid crystal display panel10as a display element arranged opposite to opening8in housing7; protective panel11arranged in housing7and functioning as a member for closing opening8; O ring12arranged on one face of protective panel11in a direction perpendicular to an opening plane of opening8and functioning as a waterproof member; sliding plate13arranged on the other face of protective panel11in a direction perpendicular to the opening plane of opening8and functioning as a holding member for holding protective panel11slidably in a direction parallel to the opening plane of opening8; and spring member14arranged such that it makes contact with an end portion in a direction parallel to the opening plane of opening8and functioning as an elastic member for supporting protective panel11in such a way that protective panel11can be displaced in a direction parallel to the opening plane of opening8. Here, in the present invention, the opening plane of opening8designates an imaginary plane including a peripheral edge of opening8.

Housing7includes: first outer case7aarranged on an outer face side of protective panel11in a direction perpendicular to the opening plane of opening8; and second outer case7barranged on an inner face side of protective panel11in a direction perpendicular to the opening plane of opening8. First outer case7ahas opening8aand has opposite face16aformed in a peripheral edge portion of opening8a, opposite face16abeing opposite to one face of protective panel11. Second outer case7bhas opening8band has opposite face16bformed in a peripheral edge portion of opening8b, opposite face16bbeing opposite to the other face of protective panel11. Opening8aof first outer case7ais formed smaller than opening8bof second outer case7b.

First outer case7aand second outer case7bare fixed to each other by screw17in the state where opposite faces16a,16bare opposed to each other, and protective panel11is arranged between first outer case7aand second outer case7b.

Liquid crystal display panel10is disposed in opening8bof second outer case7band is arranged in such a way that a display face of liquid crystal display panel10is opposite to protective panel11. Here, the display element is not limited to the liquid crystal display panel but, of course, for example, an organic EL (electroluminescence) panel and other display panels can be employed as the display element.

Protective panel11is formed of a material having optical transparency in the shape of a flat plate and the display face of liquid crystal display panel10is visible from the outside of the housing7. Protective panel11has an area larger than the display face of liquid crystal display panel10. Protective panel11is supported by housing7in a state where protective panel11is sandwiched between O ring12and sliding plate13.

O ring12is engaged with groove18formed in opposite face16aof first outer case7aand is arranged along the entire periphery of protective panel11.

A perspective view of sliding plate13of waterproof structure1in the first embodiment is shown inFIG. 4. Sliding plate13is formed of, for example, a resin material such as POM (polyacetal) or a silicon rubber which has an excellent sliding ability. Further, a member made by boding a tape material made of tetrafluoroethylene to a cushion material may be employed as sliding plate13.

Sliding plate13, as shown inFIG. 4, is formed in the shape of an annular plate, for example, in the shape of a square frame and is arranged along the entire periphery of protective panel11at a position opposite to O ring12with respect to protective panel11. For this reason, opening8of housing7is airtightly closed by protective panel11and O ring12. Here, when a material having an excellent waterproof properties such as a polymer material is used as sliding plate11, the waterproof properties can be also further enhanced as required.

First outer case7ahas holding depressed portion23formed at a position opposite to an end face of protective panel11, withholding depressed portion23holding spring member14. Spring member14is held in holding depressed portion23. Spring member14is formed of a metal material or a resin material such as elastomer and is provided with elastically deformed piece14awhich makes contact with the end face of protective panel11.

In spring member14, elastically deformed piece14a, which made contact with the end face of protective panel11, is elastically deformed to thereby hold protective panel11in such a way that protective panel11can be displaced in a direction shown by arrow (a), which is parallel to the opening plane of opening8. Although not shown in the drawing, spring member14is arranged along the respective sides of an outer peripheral portion of protective panel11.

As to waterproof structure1in the first embodiment constructed in the manner described above, the movements of protective panel11and sliding plate13will be described. A section view for illustrating movement of waterproof structure1in the first embodiment is shown inFIG. 5.

As shown inFIG. 5, in the case where protective panel11and the housing7are changed in an outside dimension by a temperature change of the electronic device, a relative displacement is caused between protective panel11and the housing7. Even in this case, in waterproof structure1, elastically deformed piece14aof spring member14is elastically deformed, whereby the amount of displacement of protective panel11and housing7can be absorbed and protective panel11slides in the state where protective panel11is held by sliding plate13. For this reason, even in the case where protective panel11slides in a direction parallel to the opening plane of opening8, O ring12is held sandwiched between first outer case7aand protective panel11and hence the airtightness can be held between them, so that the waterproof properties can be sufficiently maintained.

Further, even in the case where an impact is applied to the electronic device from the outside, for example, when the electronic device is dropped, as is the case described above, a relative displacement is caused between protective panel11and the housing7. Even in this case, in waterproof structure1, elastically deformed piece14aof spring member14is elastically deformed, whereby the amount of displacement of protective panel11and housing7can be absorbed and protective panel11slides in the state where protective panel11is held by sliding plate13. Hence, O ring12is held sandwiched between protective panel11, which slides in a direction parallel to the opening plane of opening8, and first outer case7aand hence the airtightness can be maintained between them, so that the waterproof property can be sufficiently maintained.

As described above, according to waterproof structure1which the electronic device of the first embodiment has, protective panel11is slidably held by sliding palate13and spring member14made contact with protective panel11, so that even in the case where protective panel11and case7have their outside dimensions changed or have an impact applied thereto, protective panel11and case7can maintain airtightness. As a result, according to the present embodiment, the electronic device can enhance waterproof properties and can prevent protective panel11and housing7from being broken by the impact and hence can enhance resistance to impact.

Further, according to the present embodiment, the limitation of linear expansion coefficient of a material to be used for a constituent member can be relaxed and hence freedom to combine materials to be used for the constituent member can be increased, which makes it possible to select a material whose durability is excellent.

Still further, in the present embodiment, the outer peripheral portion of protective panel11is held by elastically deformed piece14aof spring member14arranged along the respective sides of protective panel11. For this reason, protective panel11can be combined with liquid crystal display panel10in such a way that the center of an opposite face of protective panel11opposite to liquid crystal display panel10is aligned with the center of the display face of liquid crystal display panel10, which can decrease the occurrence of defects during assembly.

Hereinafter, other embodiments will be described. The other embodiments are identical in the basic construction to the first embodiment, so that the same constituent members as the constituent members in the first embodiment are denoted by the same reference symbols as in the first embodiment and their descriptions will be omitted.

A section view of a waterproof structure in a second embodiment is shown inFIG. 6. The waterproof structure in the second embodiment simplifies the construction of a housing and is different from the first embodiment in that screw17and O ring21are eliminated, screw17combining first outer case7aand second outer case7bwhich construct housing7, O ring21being interposed between first outer case7aand second outer case7b.

As shown inFIG. 6, waterproof structure2in the second embodiment includes housing27made by combining first outer case27aand second outer case27b. First outer case27aand second outer case27bare bonded to each other by use of, for example, an adhesive. Further, first outer case27aand second outer case27bmay be welded to each other in place of using the adhesive, thereby being bonded to each other.

Further, the present embodiment, as shown inFIG. 6, may be constructed in such a way that a constituent part such as a liquid crystal display panel is not arranged at a position corresponding to opening8and, as is the case with the first embodiment described above, of course, may be constructed in such a way that the liquid crystal display panel and other kinds of constituent parts are arranged at a position corresponding to opening8of housing7.

Also in the present embodiment, as is the case with the first embodiment, waterproof properties and the resistance to impact can be enhanced. In addition, according to the second embodiment, as compared with the first embodiment, O ring21is eliminated, so that the shape of first outer case27aand second outer case27bcan be simplified and hence the construction can be simplified.

A section view of a waterproof structure in a third embodiment is shown inFIG. 7. The waterproof structure in the third embodiment is different from the second embodiment in that:_protective panel11is interposed in housing37;_sliding plate13is arranged on the outer side of housing37; and O ring12is arranged on the inner side of housing37. In other words, the arrangement of sliding plate13and O ring12in the third embodiment are opposite to those in the second embodiment.

As shown inFIG. 7, waterproof structure3in the third embodiment includes housing37which is made by combining first outer case37awith second outer case37b. Sliding plate13is arranged in such a way as to make contact with an outer face of protective panel11which is arranged in opening8. Second outer case37bhas groove38formed therein, groove38having O ring12engaged therewith. O ring12is arranged in such a way as to make contact with an inner face of protective panel11arranged in opening8.

Also in the present embodiment, as is the case with the first embodiment, the waterproof properties and resistance to impact can be enhanced. In addition, in the third embodiment, by changing the arrangements of sliding plate13and O ring12as required, the freedom of fabrication of the electronic device can be enhanced.

A section view of a waterproof structure in a fourth embodiment is shown inFIG. 8. The waterproof structure in the fourth embodiment is different from the first embodiment in that the liquid display panel is fixed to a protective panel.

As shown inFIG. 8, in waterproof structure4in the fourth embodiment, the periphery of the display face of liquid crystal display panel10is bonded to protective panel11by the use of an adhesive (not shown) and liquid crystal display panel10is fixed to an inner face of protective panel11. Further, a given clearance is formed between the outer peripheral portion of liquid crystal display panel10and opening8bof second outer case7b, so that waterproof structure4is constructed in such a way that liquid crystal display panel10moving along with protective panel11does not make contact with opening8bof second outer case7b.

In the present embodiment, protective panel11and liquid crystal display panel10are integrally moved, protective panel11being slidably held in a direction parallel to the opening plane of opening8by sliding plate13and spring member14. At this time, a given clearance is formed so as to prevent liquid crystal display panel10that moved together with protective panel11from making contact with opening8bof second outer case7b, whereby liquid crystal display panel10is prevented from being broken by an impact. For this reason, by positioning and fixing liquid crystal display panel10with respect to protective panel11, the relative position of protective panel11to liquid crystal display panel10can be determined with high accuracy.

Also in the present embodiment, as is the case with the first embodiment, the waterproof property and the resistance to impact can be enhanced. In addition, in the fourth embodiment, the given clearance is formed between liquid crystal display panel10fixed to protective panel11and opening8bof second outer case7b, whereby liquid crystal display panel10can be prevented from being broken by an impact. Further, according to the fourth embodiment, it is possible to prevent a problem such that, as compared with the first embodiment, a relative shift in position is caused between protective panel11and liquid crystal display panel10in the manufacturing process.

A section view of a waterproof structure in a fifth embodiment is shown inFIG. 9. The waterproof structure in the fifth embodiment is different from the first embodiment in that a bumper member made of an elastic material is disposed in place of spring member14.

As shown inFIG. 9, in waterproof structure5in the fifth embodiment, bumper member51is disposed in holding depressed portion23of housing7in such a way that one end of bumper member51makes contact with an end face of protective panel11. Bumper member51is formed of, for example, elastomer in the shape of a square frame and protective panel11is fitted in and held by an inner peripheral portion of the square frame of bumper member51.

Also in the present embodiment, as is the case with the first embodiment, waterproof properties and resistance to impact can be enhanced. In addition, according to the fifth embodiment, it is possible to eliminate a part likely to be buckled such as elastically deformed piece14aby the use of bumper member51. Hence, it is possible to enhance the reliability of the movement of protective panel11and housing7in such a way that protective panel11and housing7can be displaced.

Here, the waterproof structure according to the present invention can be desirably applied to an electronic device having a display panel, for example, a portable music player, a portable television, and a portable disk player. Further, the present invention is not limited to the portable electronic device described above but, of course, can be suitably applied to other electronic devices, for example, a notebook type personal computer (PC), a desktop type PC, a camera, and a watch.

Up to this point, the invention of the present application has been described with reference to the embodiments. However, the invention of the present application is not limited to the embodiments described above, but various modifications that can be understood by those skilled in the art can be made for the construction and details of the invention of the present application within the scope of the invention of the present application.

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2011-047738, filed on Mar. 4, 2011, the disclosure of which is incorporated herein in its entirety by reference.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

7a—first outer case

7b—second outer case