JP4635850B2 - Infiltration liquid water-conveying structure for portable electronic devices with key buttons - Google Patents

Description

  The present invention relates to a waterproof structure in an electronic apparatus having a key button such as a cellular phone, and in particular, a liquid such as water that has entered a device over a waterproof mechanism provided in a key button opening or the like is electrically The present invention relates to a technique for preventing adhesion to parts.

  2. Description of the Related Art A portable electronic device such as a mobile phone is configured by incorporating a printed wiring board on which various electric elements are mounted in a casing. The printed circuit board built into this housing is vulnerable to liquids and dust, and if they adhere to the printed circuit board, the electrical elements on the circuit board may be corroded or destroyed and function as an electronic device. May be damaged. Among electronic devices, in the case of a mobile terminal (for example, a mobile phone terminal or a PDA), there is a possibility that the liquid may adhere to the casing due to rain or the like. There is a need to.

  In general, since a mobile terminal needs to be provided with keys for a user to perform an input operation or the like, a keyhole for exposing these keys is formed in the front case. Therefore, when it gets wet in the rain or the like, there is a risk that liquid may enter the inside of the casing from this key hole. For this reason, various waterproof structures have been proposed in order to prevent liquid from entering the inside of the apparatus through this key hole and impairing the function of the electronic device (see Patent Documents 1 to 3).

  FIG. 6 is a cross-sectional view showing a part of a conventional portable electronic device having a key button described in the above-mentioned patent documents and the like. FIG. 6A shows a state where the key button is not pressed, and FIG. b) shows a state where the key button is pressed. FIG. 7 is an enlarged view of a part of the portable electronic device shown in FIG. 6B, and is a cross-sectional view showing a state in which liquid enters the housing from the hole of the key button.

  As shown in FIG. 6, the casing of the portable electronic device is generally constituted by a front case (1) and a rear case (4), and each key button ( The openings (8) for exposing 21) are formed and arranged in, for example, 5 rows and 3 columns, and a large number of key buttons (21) such as a numeric keypad for inputting numbers and the like are provided from each opening. It is exposed one by one. These key buttons (21) are integrated with, for example, a key sheet (2) made of an elastic material such as synthetic rubber, and are arranged on the printed wiring board (5) with metal plate contacts protruding in a dome shape. The switch (51) is provided at a position corresponding to the switch (51). The peripheral portion of each key button (21) has a hook-shaped protrusion whose upper surface is pressed against the edge of the opening (8) of the front case (1) when not pressed. Water or the like is prevented from entering the mobile phone body from the gap between (21) and the opening (8).

  Further, as shown in FIG. 6B, when the key button (21) is pressed, the hook-shaped projection of the key button (21) and the edge of the opening (8) of the front case (1) are formed. There is a gap between the liquid and the liquid adhering to the key button (21) may enter the key operating portion of the front case (1). Protrusions having waterproof ribs (22) are formed, and both sides of the protrusions are pressed against the inner surface of the front case (1) and the surface on which the switch (51) of the printed wiring board (5) is disposed. By being applied, the key sheet waterproof rib (22) is crushed and is in close contact with the inner surface of the front case (1), so that liquid that has entered the key operation portion of the front case (1) will not be further inside the casing. The structure does not penetrate That.

JP 2000-151772 A JP 2003-347757 A JP 2003-308134 A

  Thus, in a portable electronic device in which key buttons for key operations are exposed on the front case, a key sheet (2) formed of rubber or the like is interposed between the front case (1) and the circuit board (5). The front case (1) and the rear case (4) are fitted to each other, and the protrusion having the key sheet waterproof rib (22) formed on the peripheral edge portion of the key sheet (2) is crushed to obtain the front case. (1) Generally, a technique for preventing liquid from entering through the keyhole by adhering to the keyhole is adopted, but the keyhole waterproofing effect by this key sheet (2) is the fit between the front case and the rear case. There is a problem that it changes depending on the condition.

  For example, if the impact force or deformation force acts on the casing due to falling, and the fitting state between the front case and the rear case is deteriorated or the key sheet is displaced, the waterproof effect is impaired, although it is slight. There is a risk that liquid may enter the housing. In addition, since the fitting state between the front case and the rear case varies from terminal to terminal due to variations in component dimensional tolerances, etc., the waterproof effect also varies from terminal to terminal, resulting in incompleteness against waterproofing. Further, when the user presses a large key button, the housing and the printed wiring board are bent, and the close contact state between the front case and the protrusion having the key sheet waterproof rib formed on the peripheral portion of the key sheet is present. It may change and the waterproof effect may be impaired.

  When the contact state between the front case (1) and the protrusion having the key sheet waterproofing rib (22) formed on the peripheral edge of the key sheet (2) is incomplete due to such a variation in component dimensional tolerance, As shown in FIG. 7, the liquid that has entered from the gap between the hook-shaped protrusion of the key button (21) and the opening edge of the front case (1) moves in the direction indicated by the arrow in the figure, There is a risk of reaching the electrical equipment (6) on the wiring board (5). As described above, in a structure in which a rubber material portion of a key sheet that is generally used in the past is crushed by a freon, a case, and a rear case, the waterproof effect is affected by the fitting state of the front case and the rear case.

  As a method for improving the imperfection of the close contact state between the protrusions having the key sheet waterproof rib (22) formed on the peripheral portion of the front case (1) and the key sheet (2), for example, as shown in FIG. It is conceivable to set the key sheet waterproof rib abutting amount higher, but in that case, the restoring force of the key sheet waterproof rib crushed by the front case to return to the state before deformation increases, and this restoring force Is exerted on the back surface of the front case, which deforms the front case and makes it difficult to operate keys.

  Further, in the case of a portable electronic device configured such that a casing in which a liquid crystal unit that is often used for a mobile phone or the like is arranged and a casing in which a key button is arranged can be folded by a hinge unit, as shown in FIG. In order to prevent the housing from opening easily when the equipment is closed, a closing force is always applied to the liquid crystal side housing and the key button side housing. There is a problem that warpage deformation occurs, and the surface of the liquid crystal side case and the key button side case come into contact with each other due to the secular change or temperature change of the closing force, and the liquid crystal surface or the key button surface is scratched. there were.

  In view of the above problems, an object of the present invention is that the close contact state between the front case and the protrusion having the key sheet waterproof rib formed on the peripheral edge portion of the key sheet is incomplete, and the liquid is contained in the casing. An object of the present invention is to provide a means that makes it possible to enhance the waterproof effect as a result of preventing the infiltrated liquid from reaching the electric equipment even if it partially penetrates.

  Another object of the present invention is to minimize the deformation of the front case and to increase the waterproofing effect by making it possible to set the abutment amount of the key sheet waterproofing rib to be high, and to carry the mobile phone so that it can be folded. An object of the present invention is to provide means for preventing contact between the surface of the liquid crystal side housing and the key button side housing due to the secular change or temperature change of the closing force in the electronic device.

  The portable electronic device having the key button of the present invention extends in a state of protruding from the inner surface of the front case from the periphery of the key sheet abutting portion on the inner surface of the front case or a part thereof to the fitting portion with the rear case. A plurality of water guiding ribs are formed for guiding the liquid leaked from the key sheet abutting portion to the inside of the case to the fitting portion with the rear case by a capillary effect.

  That is, according to the present invention, a key sheet waterproofing rib is provided around the key sheet disposed on the inner surface of the front case having an opening for the key button so as to be in close contact with the inner surface of the front case and prevent liquid from entering the inside of the device. Liquid such as water that has entered the gap between the front case and the key sheet waterproofing rib due to distortion of the case, variation in part dimensional tolerance, or bending of the case when the key button is pressed. Integrate with the front case in the range from the abutment part of the key sheet waterproofing rib on the back side of the front case to the rear case fitting part so that it does not go around to the printed circuit board side and transmit to the electrical equipment The water guide rib formed in the is formed.

  In addition, the front case side mating portion that mates with the rear case is formed with a liquid escape groove for escaping the infiltrated liquid guided by the water guide ribs, so that it enters the device and is guided by the water guide ribs. By keeping the liquid in the liquid escape groove, the intruding liquid is prevented from being transmitted to the printed wiring board side.

  In addition, the water guiding rib of the present invention also functions as a reinforcing member against an external force applied to the front case in which a plurality of openings are formed to expose the key button, so that the distortion of the housing and the variation in the component dimensional tolerance, Alternatively, it is possible to suppress the bending of the housing that occurs when the key button is pressed. Further, it is possible to set the abutting amount of the key sheet waterproof rib high without causing deformation of the front case, and it is possible to reduce the intrusion of liquid from the gap between the front case and the key sheet waterproof rib. Therefore, the waterproof effect can be further enhanced. In addition, since it functions as a member that suppresses bending of the casing due to secular change of the closing force and temperature change in the portable electronic device configured to be foldable, contact between the surface of the liquid crystal side casing and the key button side casing Can be prevented.

  According to the present invention, the close contact state between the front case and the protrusion having the key sheet waterproof rib formed on the peripheral portion of the key sheet is incomplete, and the liquid partially enters the housing. Even in the situation, the infiltrated liquid is guided to the front case and the rear case fitting portion through the water guiding rib of the present invention, and is accumulated in the liquid escape groove formed in the fitting portion. As a result, the waterproof effect of the key sheet waterproof rib can be enhanced.

  That is, by applying the present invention, the liquid that could not be prevented by the key sheet waterproof structure can escape from the electrical component and not adhere to the electrical component, and avoid corrosion, short circuit, etc. of the electrical component. Is possible.

  Moreover, since the water guiding rib of the present invention is formed integrally with the front case on the back surface of the front case, the rigidity of the case can be increased, and the function as a member for suppressing the bending of the housing can be provided. The key sheet waterproof rib can be set to a higher amount without causing deformation of the front case, and the ingress of liquid from the gap between the front case and the key sheet waterproof rib can be reduced, resulting in a waterproof effect. It can be further enhanced.

  Furthermore, since it can be provided with a function as a member that suppresses the bending of the casing due to the secular change of the closing force and the temperature change in the portable electronic device configured to be foldable, the liquid crystal side casing and the key button side Contact of the surface of the housing can be prevented, and there is also an effect of preventing the liquid crystal surface or the key button surface from being damaged due to the contact between the liquid crystal housing and the key button housing surface.

  1 is an exploded perspective view showing a part of a portable electronic device to which the present invention is applied, FIG. 2 is a perspective view showing an embodiment in which the present invention is applied to a front case of the portable electronic device, and FIG. 2 is an enlarged perspective view of FIG. 2, FIG. 4 is a sectional view showing a part of the portable electronic device of the present embodiment, and FIG. 5 is an enlarged sectional view of FIG.

  In this embodiment, as shown in FIGS. 2 to 5, from the front case (1) abutting portion of the key sheet waterproof rib (22) to the fitting portion where the front case (1) and the rear case (4) abut. A plurality of extending ribs (11) are provided. Further, a relief groove (12) for the liquid that has flowed along the rib (11) is provided in the fitting portion between the front case (1) and the rear case (4). This rib (11) uses the capillary phenomenon for the liquid that has entered the device over the key sheet waterproof rib (22) due to insufficient adhesion between the key sheet waterproof rib (22) and the front case (1). In addition to functioning as a water guide rib that leads to the liquid escape groove (12), the front case (1) has a function of suppressing bending due to an external force or the like. Hereinafter, this rib is referred to as a water guide rib (11).

  Next, operation | movement of the water guide rib (11) in this embodiment is demonstrated with reference to FIGS.

  As shown in FIGS. 4 and 5, when the key button (21) is pressed, the liquid (7) that has entered the key button opening (8) of the key button (21) and the front case (1) from the outside of the casing is If the contact between the back surface of the case (1) and the abutting portion of the key sheet waterproof rib (22) is insufficient, the key sheet waterproof rib (22) is further passed over and enters the apparatus.

  However, the liquid (7) overcoming the key sheet waterproof rib (22) extends from the key sheet waterproof rib abutting portion on the back surface of the front case to the rear case fitting portion of the front case (1). Due to the effect of capillarity caused by the water guide rib (11), the liquid is moved in the direction indicated by the arrow in the figure, and the liquid escape provided at the fitting portion of the front case (1) with the rear case (4) is provided. Driven into the groove (12). The liquid accumulated in the liquid escape groove (12) remains in the liquid escape groove (12) due to the surface tension.

  Therefore, the liquid (7) that has passed over the key sheet waterproof rib (22) is prevented from adhering to the electrical component (6) on the printed wiring board (5) through the printed wiring board (5). Since the amount of liquid over the key sheet waterproofing rib (22) is not so large, the liquid stored in the liquid escape groove (12) is moved as it is from the liquid escape groove (12). Although it does not adhere to the internal electrical components, it is also possible to provide a water guide mechanism for discharging the liquid stored in the liquid escape groove (12) to the outside of the device.

  Further, in the present embodiment, as shown in FIG. 3, the front case (1) having a key button opening (8) is provided with a plurality of ribs (11) on the back surface, so that the front case is provided. The rigidity of the can be increased. Therefore, even if the abutting force between the key sheet waterproof rib (22) and the front case (1) is set high, the key sheet waterproof rib (22) crushed by the front case (1) is in a state before deformation. It is possible to suppress the deformation of the front case due to the restoring force to return, and the waterproof effect by the key sheet waterproof rib (22) can be enhanced.

  Usually, a large number of key button openings (8) are arranged close to the inner side surface of the front case (1), so that these key button openings (8) are arranged. Providing a plurality of ribs (11) on the inner side surface of the front case (1) is particularly effective in increasing the rigidity of the front case. Furthermore, the increase in the rigidity of the front case due to the plurality of water guiding ribs (11) is different from the key pressed when the front case between keys is accidentally pressed during continuous key input during key operation. It is also effective against problems that cause the key to react.

  In addition, by providing a plurality of water guide ribs (11) of the present embodiment for a portable electronic device in which the liquid crystal part and the key button side are folded at the hinge part, the housing can be easily closed when the apparatus is closed. It is possible to suppress the warping deformation of the front case due to the closing force that is always applied between the liquid crystal side housing and the key button side housing so that the body does not open. It is possible to prevent the liquid crystal surface or the key button surface from being scratched by contacting the front surfaces of the button-side housing.

  In the above embodiment, the plurality of ribs (11) extending from the front case (1) abutting portion of the key sheet waterproof rib (22) to the fitting portion where the front case (1) and the rear case (4) abut against each other. However, instead of a plurality of ribs (11), from the front case (1) abutting portion of the key sheet waterproof rib (22) to the fitting portion where the front case (1) and the rear case (4) abut against each other A plurality of extending grooves are provided, and due to the effect of capillary action by these grooves, the liquid that has passed over the key sheet waterproof rib (22) and has been immersed in the device is fitted to the rear case (4) of the front case (1). It can also be set as the structure moved to the liquid escape groove | channel (12) provided in the part.

  In this case, although the effect of increasing the rigidity of the front case by providing the plurality of water guide ribs (11) cannot be obtained, the rigidity of the front case is increased by increasing the thickness around the front case (1). This can be dealt with by increasing the number.

It is a disassembled perspective view which shows a part of portable electronic device to which this invention is applied. It is a perspective view which shows embodiment which applied this invention with respect to the front case of a portable electronic device. FIG. 3 is an enlarged perspective view of FIG. 2. It is sectional drawing which shows a part of portable electronic device of this embodiment. It is an expanded sectional view of FIG. It is sectional drawing which shows a part of portable electronic device which has the conventional key button. FIG. 7 is a partially enlarged cross-sectional view of the portable electronic device shown in FIG. 6. It is sectional drawing for description of the portable electronic device which has the conventional key button. It is explanatory drawing of the foldable portable electronic device which has a key button.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front case 2 Key sheet | seat 4 Rear case 5 Printed wiring board 6 Electrical component 7 Liquid 8 Key button opening 11 Water conveyance rib 12 Liquid escape groove 21 Key button 22 Key sheet waterproof rib 51 Switch

Claims (6)

  Extends from the front case inner surface, extending from the periphery of the key sheet abutting portion on the inner surface of the front case to a fitting portion with the rear case, and leaks from the key sheet abutting portion to the inside of the case A portable electronic device having a key button, wherein a plurality of ribs for guiding the liquid to a fitting portion with the rear case are formed by a capillary effect.   The portable electronic device having a key button according to claim 1, wherein the plurality of ribs are provided on an inner side surface portion of the front case where an opening for exposing the key button is disposed.   The liquid that leaks into the case from the key sheet abutting portion extends from the key case abutting portion around the key sheet abutting portion or a part thereof to the fitting portion with the rear case. A portable electronic device having a key button, wherein a plurality of concave grooves that lead to a fitting portion with the rear case are formed by a phenomenon effect.   4. The portable electronic device having a key button according to claim 3, wherein the plurality of grooves are provided in an inner side surface portion of the front case in which an opening for exposing the key button is disposed.   5. The liquid escape groove for escaping liquid guided by the capillary effect is formed in a fitting portion between the front case and the rear case. 6. A portable electronic device having the described key button. The portable electronic device is configured such that a housing in which a display unit is arranged and a housing in which a key button is arranged can be folded by a hinge unit, and when the device is closed, the display unit is The key button according to any one of claims 1 to 5, wherein a closing force is urged in a closing direction with respect to the arranged housing and the housing in which the key button is arranged. A portable electronic device having.

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