JP4104337B2 - Multi-directional resin key top - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin key top used in a pushbutton switch for input in an electronic device such as a portable information terminal or an AV device. More specifically, the present invention relates to an outer peripheral resin key top and a central resin key top arranged inside the resin key top. The present invention relates to a multi-directional resin key top.
[0002]
[Prior art]
For pushbutton switches (keys) for input in electronic devices such as portable information terminals, a key sheet with a resin key top mounted on it covers it because of its good operability and abundant design variations. Often used as a member. The resin key top is often formed of a molded product made of a thermoplastic resin, and is provided with a display portion with characters and symbols indicating operational functions. On the other hand, the key sheet is often formed of a rubber-like elastic body such as synthetic rubber or thermoplastic elastomer, or is formed of a flexible resin film. Conventionally, a resin key top is generally attached to the key sheet with an adhesive.
[0003]
By the way, as one of the resin key tops, there is a multi-directional resin key top used for selecting and confirming a function together with a liquid crystal display screen mounted on the portable information terminal such as a mobile phone. A typical configuration in the prior art is shown in FIG. As shown in the figure, the multi-directional resin key top is composed of an outer peripheral resin key top 101 formed in an annular shape, and a central resin key top 102 arranged inside the outer peripheral resin key top 101, each of which is The key sheet 103 is attached by being fixed with an adhesive 104. Further, the outer peripheral resin key top 101 is adapted to engage with the casing 106 of the device via a hook-shaped convex portion 105 provided at the lower end portion of the outer surface.
[0004]
[Problems to be solved by the invention]
The conventional multi-directional resin key top as described above has a problem of instability of mounting in the central resin key top 102 that is repeatedly pressed to confirm the selected function. That is, in the conventional multi-directional resin key top, the central resin key top 102 is only attached by being fixed to the key sheet 103 with the adhesive 104 inside the outer peripheral resin key top 101, and therefore When the central resin key top 102 is peeled off from the key sheet 103 due to repeated impacts caused by frequent pressing, it becomes a state of being detached, and a necessary operation cannot be performed.
[0005]
The present invention has been made against the background of such a conventional technique. An object of the present invention is to provide a multi-directional resin key top that can effectively eliminate the mounting instability in the central resin key top.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has an annular outer peripheral resin key top and a central resin key top disposed inside the outer peripheral resin key top, and is mounted on a key sheet covering the push button switch. In the multi-directional resin key top used, the outer peripheral resin key top prevents the central resin key top from separating between the lower inner side surface of the outer peripheral resin key top and the lower side surface of the central resin key top. An engagement structure is provided. Therefore, according to this multi-directional resin key top, it is possible to effectively prevent the problem of detachment of the central resin key top, which is a problem with the conventional multi-directional resin key top. The "annular" outer peripheral resin key top is a shape that surrounds the center resin key top, even if it is integrally formed over the entire circumference of the "annular" It may be formed.
[0007]
Further, in the present invention, for the multi-directional resin key top as described above, the outer peripheral resin key top is fixedly mounted on the key sheet, while the central resin key top is free from the key sheet. Mounted on the key sheet through the engagement structure, and the engagement structure is a pressing force transmitted to the central resin key top through the engagement structure when the outer peripheral resin key top is pressed. Is received by moving the central resin key top in the lateral direction. Therefore, according to this multi-directional resin key top, it is also possible to avoid the possibility of erroneous input of the central resin key top accompanying pressing of the outer peripheral resin key top.
[0008]
Further, in the present invention, with respect to the multi-directional resin key top as described above, the engagement structure includes a recessed portion provided to be recessed toward the outer surface side at the lower inner surface of the outer peripheral resin key top, and the central resin key. A convex portion provided so as to protrude outward on the side of the top side is formed so as to be engaged, and an inclined surface is provided to both or one of the concave portion and the convex portion. The center resin key top is caused to move in the lateral direction by transmitting the pressing force of the outer peripheral resin key top through the center resin key top. Therefore, according to this multi-directional resin key top, the lateral movement of the central resin key top is smoothly performed. And if both the said recessed part and a convex part are formed as an inclined surface where the inclination directions substantially correspond and the surfaces face each other, the engagement between the inclined surfaces becomes more dense and the rattling of the central resin key top is suppressed. be able to.
[0009]
Further, in the present invention, in the multi-directional resin key top as described above, the outer peripheral resin key top is fixedly mounted on the key sheet, while the central resin key top is a protrusion that supports the bottom surface from below. The key sheet formed with a protrusion is mounted on the key sheet via the engagement structure in a state supported by the protrusion, and the outer peripheral resin key top is pressed in the engagement structure. At this time, the pressing force transmitted to the central resin key top through the engagement structure is formed so as to be received by tilting of the central key top with the support point by the protrusion as a swing fulcrum. . Therefore, according to this multi-directional resin key top, it is possible to avoid the possibility of erroneous input of the central resin key top by tilting the central resin key top with the support point as a swing fulcrum.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, an engagement structure is provided between the outer peripheral resin key top and the central resin key top, and this engagement structure effectively eliminates the phenomenon of separation of the central resin key top, which has been a problem with conventional multi-directional resin key tops. It is based on prevention. Such an engagement structure can be implemented in various forms. As a typical engagement structure, a concave portion that is recessed toward the outer surface side is provided on the inner surface lower portion of the outer peripheral resin key top. There is an engagement structure in which a convex portion protruding outward is provided at the lower side of the side surface of the central resin key top, and the concave portion and the convex portion are engaged. Hereinafter, main embodiments of the engagement structure by the concave and convex portions will be described.
[0011]
First Embodiment [FIGS. 1 and 2] FIG. 1 shows a cross-sectional structure of a multi-directional resin key top according to a first embodiment. In the present embodiment, an engagement structure is provided to the annular outer peripheral resin key top 1 and the columnar central resin key top 2, and they are fixed to the key sheet 3 with an adhesive 4. The engagement structure of the outer peripheral resin key top 1 and the central resin key top 2 is provided with a recess 5 that is recessed toward the outer surface at the lower end of the inner surface of the outer peripheral resin key top 1, while the lower end of the side surface of the central resin key top 2. This is a structure in which a convex portion 6 protruding outward is provided on the portion, and the concave portion 5 and the convex portion 6 are engaged. The concave portion 5 and the convex portion 6 of this embodiment are both formed in a continuous annular shape, but may be formed discontinuously. Further, in this example, the concave portion 5 and the convex portion 6 are provided at the lower end portions of the outer peripheral resin key top 1 and the central resin key top 2, respectively. What is necessary is just to provide. Note that the outer peripheral resin key top 1 is engaged with the housing 8 of the device via the hook-shaped convex portion 7 provided at the lower end portion of the outer surface. It is the same.
[0012]
The outer peripheral resin key top 1 can be formed by injection molding using a thermoplastic resin, preferably a polycarbonate resin, for example. Further, this outer peripheral resin key top 1 is provided with a display portion on which an aluminum vapor deposition layer (not shown) is formed on the back surface and four arrows in the vertical and horizontal directions are displayed on the front surface. On the other hand, the central resin key top 2 is formed of a thermoplastic resin different from that of the outer peripheral resin key top 1, and is preferably injection-molded using, for example, acrylonitrile butadiene styrene resin. Since the key sheet 3 is repeatedly deformed by being pressed by the outer peripheral resin key top 1 and the central resin key top 2, a flexible and highly durable material such as a rubber-like material such as a synthetic rubber or a thermoplastic elastomer is used. Although an elastic body can be used, in this embodiment, as a particularly preferable material among such rubber-like elastic bodies, the central resin key top 2 is pressed by the outer peripheral resin key top 1 and is placed on the flat placement surface of the key sheet 3. Is made of silicone rubber having a small friction coefficient so that it can be easily slid. As the adhesive 4, for example, a UV curable adhesive that can be cured in a few seconds and can greatly improve productivity can be used.
[0013]
Thus, by providing the engagement structure by the concave portion 5 and the convex portion 6 between the outer peripheral resin key top 1 and the central resin key top 2, even if the central resin key top 2 is peeled off from the key sheet 3, the engagement is achieved. Since the central resin key top 2 can be held by the outer peripheral resin key top 1 according to the structure, it can be effectively prevented from being detached. However, in the present embodiment in which the central resin key top 2 is also fixed to the key sheet 3 with an adhesive, the following phenomenon may be caused. That is, as shown in FIG. 2, when the outer peripheral resin key top 1 is pressed, the pressing force F is transmitted to the central resin key top 2 through the engagement structure by the concave portion 5 and the convex portion 6, thereby the central resin key top. This means that the top 2 may also be pressed in an interlocking manner and cause an erroneous input. The possibility of such an interlocking erroneous input phenomenon can be effectively avoided in the second and subsequent embodiments described below.
[0014]
Second Embodiment [FIGS. 3 and 4] ; FIG. 3 shows a cross-sectional structure of a multi-directional resin key top according to the second embodiment. In the present embodiment, the annular outer peripheral resin key top 11 is fixed to the key sheet 3 with the adhesive 4, but the cylindrical central resin key top 12 is not fixed to the key sheet 3 and is free. In other words, the key sheet 3 is loosely fitted to the outer peripheral resin key top 11 so as to be movable relative to the key sheet 3 in the surface direction and the direction perpendicular to the surface. At the same time, the upper surface 15f of the concave portion 15 in the outer peripheral resin key top 11 is a downward inclined surface from the inner peripheral surface to the bottom surface of the outer peripheral resin key top 11, while the upper surface 16f of the convex portion 16 in the central resin key top 12 is. The skirt shape is a downward sloping surface facing outward. The lower end outer edge of the convex portion 16 of the central resin key top 12 and the lower end inner edge of the recess 15 of the outer peripheral resin key top 11 are opposed to each other by a clearance of about width d.
[0015]
In this way, the central resin key top 12 is made free with respect to the key sheet 3, and the inclined direction substantially coincides with the concave portion 15 of the outer peripheral resin key top 11 and the convex portion 16 of the central resin key top 12. By forming the inclined surface 15f and the inclined surface 16f facing each other, the mounting stability of the central resin key top 12 is ensured, and the interlocking erroneous input phenomenon as in the first embodiment is effectively avoided. can do.
[0016]
That is, the central resin key top 12 is fixed to the concave portion 15 of the outer peripheral resin key top 11 fixed to the key sheet 3 by the adhesive 4 and engaged with the casing 8 of the device via the hook-shaped convex portion 17. The center resin key top 12 can be stably mounted by engaging the convex portion 16 of the center. In particular, since the inclined surface 15f and the inclined surface 16f are provided to the concave portion 15 and the convex portion 16, respectively, the engagement by the concave portion 15 and the convex portion 16 becomes close, and the rattling of the central resin key top 12 is small and the mounting is stable. The property can be made higher.
[0017]
On the other hand, as shown in FIG. 4, when the outer peripheral resin key top 11 is pressed, the downward pressing force F transmitted to the central resin key top 12 through the engagement structure by the concave portion 15 and the convex portion 16 is the central resin key. It is changed to a laterally forward force f via the inclined surface 16f of the convex portion 16 of the top 12, and thereby the inner diameter of the concave portion 15 of the outer peripheral resin key top 11 is made larger than the outer diameter of the convex portion 16 of the central resin key top 12. The central resin key top 12 moves in the lateral direction by an amount corresponding to the clearance allowance formed by the large diameter so that the downward pressing force F is received. It is possible to effectively avoid the occurrence of input.
[0018]
Third Embodiment [FIG. 5] FIG. 5 shows a cross-sectional structure of a multidirectional resin key top according to a third embodiment. In this embodiment, the outer peripheral resin key top 21 is divided into four parts and formed into an annular shape, and the upper surface 26 f of the convex portion 26 in the central resin key top 22 is formed flat. Therefore, when the outer peripheral resin key top 21 is pressed, the downward pressing force transmitted to the central resin key top 22 through the engagement structure by the concave portion 25 and the convex portion 26 is transmitted through the inclined surface 25f in the concave portion 25 of the outer peripheral resin key top 21. Can be changed to a forward-looking force. Since other configurations are the same as those of the second embodiment, the same reference numerals are given to common portions, and descriptions thereof are omitted.
[0019]
Fourth Embodiment [FIG. 6] FIG. 6 shows a cross-sectional structure of a multidirectional resin key top according to the fourth embodiment. This embodiment is an example in which the multi-directional resin key top according to the second embodiment is modified, and the upper surface 35f of the recess 35 in the outer peripheral resin key top 31 is formed flat. Since other configurations are the same as those of the second embodiment, the same reference numerals are given to common portions, and descriptions thereof are omitted.
[0020]
Fifth Embodiment [FIG. 7] FIG. 7 shows a cross-sectional structure of a multidirectional resin key top according to a fifth embodiment. The present embodiment is an example in which the multi-directional resin key top of the fourth embodiment is modified. A key-shaped 43 has a flat top surface and a rounded trapezoidal protrusion 43a. at Jo portion 43 a is obtained so as to support the bottom surface of the central resin key top 12. The top surface of the projecting portion 43 a center resin key top 12 so are the flat is supported stably. Incidentally, the projecting portion 43 a is not particularly limited as long as central resin key top 12 can be tilted as described below, as conical or polygonal pyramid shaped apex pointed shape, or the top surface of the dome-shaped curved surface Or a part of which the protrusions are formed.
[0021]
Key sheet 43 formed of such a protrusion 43 a, it means that repeated deformed by the pressing of the outer resin key top 1 and central resin key top 2, a is flexible durable material Although it is preferable to use this, in this embodiment, the support area with respect to the bottom surface of the central resin key top 12 is small, but when the central resin key top 12 is pressed, the pressing force must be reliably transmitted to the key sheet 43. Therefore, a material having a large coefficient of friction and a material that does not easily slide the central resin key top 12, such as a styrene-based thermoplastic elastomer, an olefin-based thermoplastic elastomer, isoprene rubber, ethylene-propylene rubber, and diene-based rubber is particularly preferable. In addition, a tapered portion 31 a that expands upward is formed on the upper inner peripheral surface of the outer peripheral resin key top 31 so as to form a predetermined clearance with the outer peripheral surface of the central resin key top 12. Yes.
[0022]
In this multi-directional resin key top, when the outer peripheral resin key top 31 is pressed, the downward pressing force F transmitted to the central resin key top 12 through the engagement structure by the concave portion 35 and the convex portion 16 causes the projecting portion. a flat top surface of the edge of the 43 a tilting central resin key top 12 as a swing fulcrum p. At this time, the tip side portion of the convex portion 16 of the central resin key top 12 tilts while rotating in the concave portion 35 formed as a flesh escape space allowing the convex portion 16 to rotate on the outer peripheral resin key top 31. To go. In this way, the central resin key top 12 is in a state of receiving the downward pressing force F, and it is possible to effectively prevent an erroneous input from occurring in the central resin key top 12.
[0023]
【The invention's effect】
According to the present invention, the central resin key top is engaged with the outer peripheral resin key top by the engagement structure provided between the outer peripheral resin key top and the central resin key top. Stability can be increased. And the high mounting | wearing stability can be acquired even if the center resin key top does not adhere to the key sheet. In the present invention, the central resin key top is made free with respect to the key sheet by utilizing this fact so that the pressing force from the outer peripheral resin key top transmitted to the central resin key top through the engagement structure can be received. By doing so, the possibility of erroneous input of the central resin key top accompanying pressing of the outer peripheral resin key top can be avoided, and the effectiveness of the engagement structure can be further enhanced.
[Brief description of the drawings]
FIG. 1 is an explanatory view of the structure of a multi-directional resin key top according to a first embodiment, wherein a part (a) is a sectional view taken along line SB-SB of the part (b), and a part (b) is a plan view. .
2 is a cross-sectional view showing a state in which the outer peripheral resin key top is pressed in the multi-directional resin key top of FIG.
FIG. 3 is a cross-sectional view of a multidirectional resin key top according to a second embodiment.
4 is a cross-sectional view showing a state in which the outer peripheral resin key top is pressed in the multidirectional resin key top of FIG. 3;
FIGS. 5A and 5B are structural explanatory views of a multi-directional resin key top according to a third embodiment. FIG. 5A is a sectional view taken along the line SC-SC in FIG. 5B, and FIG. 5B is a plan view. .
FIG. 6 is a cross-sectional view of a multidirectional resin key top according to a fourth embodiment.
FIGS. 7A and 7B are explanatory views of the structure and operation of a multi-directional resin key top according to a fifth embodiment. FIG. 7A is a sectional view, and FIG. It is sectional drawing shown.
FIGS. 8A and 8B are explanatory diagrams of the structure of a conventional multi-directional resin key top. FIG. 8A is a sectional view taken along line SA-SA in FIG.
[Explanation of symbols]
1 Perimeter resin key top (first embodiment)
2 Central resin key top (first embodiment)
3 Key sheet 5 Recess 5f Upper surface (inclined surface)
6 convex part 6f upper surface (inclined surface)
11 Peripheral resin key top (second embodiment)
12 Central resin key top (second embodiment)
15 Recess 15f Upper surface (inclined surface)
16 convex part 16f upper surface (inclined surface)
21 Peripheral resin key top (second embodiment)
22 Central resin key top (third embodiment)
25 Concave portion 25f Inclined surface 26 Convex portion 26f Upper surface 31 Peripheral resin key top (fourth embodiment)
35 concave portion 35f upper surface 43 key sheet (fifth embodiment)
43a Projection

Claims (5)

In a multi-directional resin key top that has an annular outer peripheral resin key top and a central resin key top arranged on the inner side of the outer peripheral resin key top, and is used by being mounted on a key sheet that covers a push button switch,
The outer peripheral resin key top is fixed to the key sheet and has a recess provided to be recessed toward the outer surface at the lower part of the inner surface, and the central resin key top is formed on the flat mounting surface of the key sheet. It is mounted so as to be relatively movable, and has a convex portion provided so as to protrude outward and enter the concave portion at the lower portion of the outer surface. The top can be secured against the outer peripheral resin key top,
The inclined surface on at least one of them with further face each other with a gap between the recess and the central resin key top of the convex portion of the outer peripheral resin key top to allow relative movement with respect to the outer peripheral resin key top in the plane direction of the placement surface The concave portion of the outer peripheral resin key top that is displaced by pressing contacts the convex portion of the central resin key top and slides through the inclined surface, so that the central resin key top escapes the clearance. A multi-directional resin key top characterized by sliding in the surface direction of the mounting surface as described above. 2. The multi-directional resin key top according to claim 1, wherein the inclined direction substantially coincides with both the concave portion of the outer peripheral resin key top and the convex portion of the central resin key top so that the inclined surfaces face each other. In a multi-directional resin key top that has an annular outer peripheral resin key top and a central resin key top arranged on the inner side of the outer peripheral resin key top, and is used by being mounted on a key sheet that covers a push button switch,
The outer peripheral resin key top is fixed to the key sheet, and has a recess provided to be recessed toward the outer surface at the lower part of the inner surface, and the central resin key top is a protruding portion provided on the key sheet. And has a convex portion provided so as to protrude outward and enter the concave portion at the lower portion of the outer surface, and the convex portion is engaged with the concave portion so that the central resin The key top can be secured against the outer peripheral resin key top,
Further forms a clearance that allows tilting of the central resin key top between the outer surface portion and the outer peripheral resin key inner surface upper part of the top of the central resin key top, and the recess of the outer resin key top central resin The center resin is formed as a meat escape space having a gap that allows the protrusion of the key top to rotate, and the concave portion of the outer peripheral resin key top that is displaced by pressing comes into contact with the convex portion of the central resin key top. The upper part of the outer surface of the key top rotates in the clearance and approaches the upper part of the inner surface of the outer peripheral resin key top, and the convex part of the central resin key top rotates in the meat escape space to A multi-directional resin key top characterized in that the central resin key top rotates and tilts on the projecting portion when approaching the inner surface of the recess. 4. The multidirectional resin key top according to claim 3, wherein an inclined surface is formed on one of the concave portion of the outer peripheral resin key top or the convex portion of the central resin key top. The multi-directional resin key top according to claim 3 or 4, wherein the clearance is formed by a tapered portion that expands toward the upper part of the upper part of the inner side surface of the outer peripheral resin key top.

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