JP2646192B2 - Key top plate of push button switch and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key top plate for a push button switch and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a key top plate formed by molding a key top made of a molded resin directly on a film plate made of a resin film has been developed in order to achieve a reduction in size and thickness. In order to complete the waterproof function, a key top plate of a type that forms a key top by forming a key top by curving the film plate and filling the curved portion with mold resin without providing any through hole in the film plate Have been.

FIG. 12 is a schematic side sectional view showing a key portion of a conventional key top plate of this type. As shown in FIG.
Is formed by bending a transparent film plate 201 upward to provide a curved portion 203, and at the same time, filling a mold resin 205 in the curved portion 203 and solidifying the resin. The fixing between the curved portion 203 and the mold resin 205 is performed by an adhesive print layer 207 (a layer in which an adhesive layer is applied below the print layer) applied to the entire back surface of the curved portion 203. This adhesive printed layer 207 is a key top 2
02 has the function of decorating it with a desired color and pattern, and at the same time, bonding it to the mold resin 205 thereunder.

[0004] To manufacture the key top plate 200,
As shown in FIG. 13, a film plate 201 which is a thermoplastic resin film and has an adhesive printed layer 207 (not shown) printed on its lower surface is strongly sandwiched between upper and lower dies a and b. At this time, a cavity a1 having the same shape as the upper portion of the key top 202 is provided in the upper die a, and a cavity b1 having the same shape as the lower portion of the key top 202 is provided in the lower die b. Is provided.

Then, a high-temperature and high-pressure molten molding resin is press-fitted from a pin gate b2 provided in a cavity b1 of the lower die b. As a result, the cavity mold b1 of the lower mold b is filled with the molten mold resin.

As shown by a dotted line in the figure, the film plate 201 located in the cavity a1 of the mold a is pushed up while being stretched by the heat and pressure of the molten mold resin, deformed, and deformed. A curved portion 203 is formed in close contact with the inner surface of a1, and at the same time, the cavity a1 is filled with a molten mold resin. Thus, a key top plate 200 as shown in FIG. 12 is completed.

[0007]

However, in the above method, when the mold resin 205 is molded into the film plate 201 by the heat and pressure of the molten mold resin, the film plate 201 is deformed into the shape of the curved portion 203. It must be extended considerably, but at this time, the film plate 20
There is a possibility that an outer peripheral portion of the portion serving as the first curved portion 203 may be dragged into the cavity a1 in the direction of the arrow c.

When a plurality of key tops 202 are formed on the key top plate 200, if the amount of dragging is different for each key top 202, the enlargement ratio of the adhesive print layer 207 printed on each key top 202 is determined. Are different from each other, and the size of the decoration pattern provided on each key top 202 is different, resulting in non-uniformity.

If the amount of dragging from the periphery of the curved portion 203 in one key top 202 is not constant depending on the location, the enlarged design of the adhesive print layer 207 may be distorted.

This is a film plate 201 for upper and lower molds a and b.
This is because the entire surface to be tightened is a flat surface, so that the area around the curved portion 203 of the film plate 201 is not necessarily firmly tightened.

In order to firmly tighten the periphery of the curved portion 203 of the film plate 201, as shown in FIG.
A ring-shaped protrusion a3 may be provided around the cavity a1 of the upper mold a, and only the periphery of the curved portion 203 of the film plate 201 may be tightly tightened. However, since the protrusion a3 is hard due to its material, it is not always possible to press down the portion around the curved portion 203 of the film plate 201 with a uniform pressure, and conversely, the entire lower surface of the protrusion a3 is evenly pressed. It was not easy to work on a flat surface. Further, since the protruding portion a3 is hard, the film plate 201 may be damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a curved portion for forming a key top of a film plate, in which an outer peripheral portion is drawn into the curved portion. An object of the present invention is to provide a key top plate of a push button switch which can be easily restricted and does not damage the film plate at that time, and a method of manufacturing the same.

[0013]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention comprises a film plate made of a flexible resin film, and a portion of the film plate having no through-hole is bent upward. At the same time, the mold resin is directly fused into the curved portion, or is bonded via an adhesive layer, or the curved portion is filled with the mold resin and the film plate is provided with a through-hole provided outside the curved portion. In a key top plate of a push button switch in which a key top is formed by molding the mold resin above and below a hole and sandwiching the film plate, at least a surface or a back surface of an outer periphery of a curved portion of the film plate is further provided. A printing layer is provided to increase the thickness of the film plate as compared with the outer portion. Further, the present invention provides an upper mold having a cavity having the same shape as the upper shape of the keytop, a lower mold having a cavity having the same shape as the lower shape of the keytop, and a film plate, By sandwiching the film plate between the upper mold and the lower mold and injecting the molten resin into a cavity provided in the lower mold, the heat and pressure of the molten resin cause any through-holes in the film plate. A push button switch that deforms and pushes up the non-existing portion to make it closely adhere to the inner surface of the cavity of the upper mold, fills both the cavities of the upper and lower molds with molten resin, and removes the upper and lower molds after the molten resin is solidified. The method of manufacturing a key top plate, wherein before the film plate is sandwiched between the upper and lower molds, a surface or a back surface of an outer peripheral portion of the deformed portion of the film plate is compared with a further outer portion in advance. hand It was decided to provide a step allowed to print the print layer to increase the thickness of the film plate.

[0014]

Since a printing layer thicker than the surrounding portion is provided on the film plate, when the film plate is sandwiched between the upper and lower dies A and B, the portion provided with the printing layer is concentrated. Be tightened. In other words, it is tightened more strongly than the outer part. At this time, since the printing layer has a certain degree of elasticity, a specific portion of the portion on which the printing layer is printed is not particularly strongly or weakly tightened. That is, they are tightened substantially uniformly. Moreover, because of its elasticity, the film plate will not be damaged even if it is strongly tightened.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing a key top portion 15 of a key top plate 10 according to a first embodiment of the present invention.
FIG. 2A is a schematic side sectional view of a main part, and FIG. 2B is a perspective view of the main part. FIG. 2 is a schematic side sectional view of a main part showing a method of manufacturing the key top plate 10.

As shown in FIG. 1, the key top plate 10
The key top 15 is formed by bending a portion of the film plate 11 having no through hole upward, and simultaneously fusing the mold resin 19 directly into the curved portion 17. And the film plate 1
A printing layer 21 for a predetermined color / pattern is printed on the entire upper surface of the print head 1, and an annular printing layer 23 is printed on the outer surface of the curved portion 17 on the printing layer 21.
Hereinafter, each component will be described.

The film plate 11 is made of a flexible thermoplastic resin film, for example, PETP (polyethylene terephthalate).

The mold resin 19 is made of a thermoplastic resin, for example, PMMA (polymethyl methacrylate) or PC (polycarbonate). A pressing portion 25 projects from the center of the lower surface of the mold resin 19.

The printing layer 21 is printed on the entire surface of the film plate 11 and forms a predetermined color or pattern. Although the printing layer 21 is shown as a single layer in the drawing, it may be formed by applying a plurality of layers.

As described above, the printing layer 23 is annularly printed on the outer peripheral surface of the curved portion 17. This printing layer 23
Although FIG. 1 shows only one layer, it may be formed by applying a plurality of layers. The thickness of the portion of the film plate 11 where the printing layer 23 is provided is larger by the thickness of the printing layer 23 than the thickness of the film plate 11 outside the printing layer 23.

According to the present invention, by providing the printing layer 23, when forming the key tops 15 on the film plate 11, the drawing-in of the film plate 11 around the curved portion 17 is restricted. Next, the operation will be described.

That is, in order to form the key tops 15 on the film plate 11, as shown in FIG. 2, a printing layer 21 is applied to the surface of a flat film plate 11 having no through hole, and an annular ring is formed thereon. Print the printed layer 23 on the upper and lower molds A and B
Between the two.

Here, the upper mold A is provided with a cavity A1 having the same shape as that of the upper part of the key top 15, and the lower mold B is formed with the lower part of the key top 15 (ie, the pressing portion 25). Cavity B1 of the same shape as
And a pin gate B2.

As shown in FIG. 1, a printing layer 23 having a thickness greater than that of the surrounding portion is provided on the film plate 11, so that when the film plate 11 is sandwiched between the upper and lower dies A and B. The portion where the print layer 23 is provided is intensively tightened, and is more strongly tightened than the outer portion.

At this time, since the printing layer 23 has a certain degree of elasticity, a specific portion of the annular portion on which the printing layer 23 is printed is not particularly strongly or weakly tightened. That is, they are tightened substantially uniformly. Moreover, because of its elasticity, the film plate 11 can be tightly tightened.
It will not be scratched.

In this state, high-temperature and high-pressure molten molding resin, for example, P
The molten mold resin is filled into the cavity B1 of the lower mold B by press-fitting C or PMMA.

As shown in FIG. 2, the film plate 11 located in the cavity A1 of the mold A is pushed up while being stretched by the heat and pressure of the molten mold resin filled from the pin gate B2 and deformed. Then, as shown by a dotted line, the curved portion 1 is in close contact with the inner surface of the cavity A1.
7 are formed, and at the same time, the cavity A1 is filled with the molten mold resin.

After cooling, the upper and lower dies A and B are removed, and the key top plate 10 shown in FIG. 1 is completed.

By the way, the inventor of the present application stretches the thermoplastic resin film under the condition of high temperature and high pressure and touches it with the molten mold resin of high temperature and high pressure, so that the resin film and the mold resin do not use any adhesive. It was also found by various experiments that both were firmly fused together.

Therefore, as in the above embodiment, the film plate 1
If the film 1 is stretched in a high-temperature and high-pressure state to form the curved portion 17 and at the same time the high-temperature and high-pressure molten mold resin is brought into contact with the film plate 11, both are firmly fused and fixed without an adhesive. .

The molding resin 19 may be formed after an adhesive layer is printed on the lower surface of the film plate 11 in advance. In this case, the film layer 11 is formed by the adhesive layer.
Is firmly bonded between the curved portion 17 and the mold resin 19.

The film plate 1 provided with the key top 15
Since there is no need to provide any through-hole in the portion 1, a complete waterproof function can be provided.

[Second Embodiment] Next, FIG. 3 is a view showing a portion of a key top 35 of a key top plate 30 according to a second embodiment of the present invention, and FIG. FIG. 2B is a perspective view of a main part. FIG. 4 is a schematic side sectional view of a main part showing a method of manufacturing the key top plate 30. In this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

This embodiment is different from the first embodiment in that the printing layer 23-2 corresponding to the annular printing layer 23 in the first embodiment is replaced by the surface (upper surface and side wall surface) of the curved portion 17. Is formed by protruding the printing layer 21 to be printed on the outer periphery of the curved portion 17 and printing. That is, the printing layer 23-2 is a part of the printing layer 21.

Even if the printing layer 23-2 is configured as described above,
As shown in FIG. 4, the upper and lower molds A and B are intensively tightened at the portion of the printing layer 23-2, and are tightened more strongly than the outer portion thereof. Therefore, the same effects as described in the first embodiment are obtained.

[Third Embodiment] FIG. 5 is a view showing a portion of a key top 45 of a key top plate 40 according to a third embodiment of the present invention. FIG. FIG. 1B is a perspective view of a main part. FIG. 6 is a schematic side sectional view of a main part showing a method of manufacturing the key top plate 40. In this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The difference of this embodiment from the first embodiment is that the printing layer 23-3 corresponding to the annular printing layer 23 in the first embodiment extends from the side wall portion of the curved portion 17 to the outer periphery thereof. This is a point provided radially at predetermined intervals.

Even if the printing layer 23-3 is configured as described above,
As shown in FIG. 6, the upper and lower dies A and B are intensively tightened at the portion of the print layer 23-3, and are tightened more strongly than the outer portion. Therefore, the same effects as described in the first embodiment are obtained.

Further, in the case of this embodiment, the printing layer 23-
3, the cavity A1 of the upper mold A is provided.
The effect of bleeding air that easily accumulates inside is also exhibited.

That is, as shown in FIG. 6, when the molten mold resin is press-fitted from the pin gate B2, the film plate 11 is deformed into a dome shape as shown by a dotted line and an arrow in FIG. All of them closely adhere to the inner wall surface of the cavity A1. At this time, the portion that does not adhere to the end is the circumferential R portion A3 of the cavity A1. That is, the air in the cavity A1 does not escape and easily accumulates in the space near the R portion A3. When air accumulates in the R portion A3, the shape of the R portion A3 cannot be accurately formed.

However, if the print layers 23-3 are provided radially at predetermined intervals as in the present embodiment, the air accumulated near the R portion A3 can be removed from the gap between the adjacent print layers 23-3. Exhausted to the outside. Therefore, the above problem due to the air accumulation phenomenon does not occur at all.

[Fourth Embodiment] FIG. 7 is a view showing a key top 55 of a key top plate 50 according to a fourth embodiment of the present invention. FIG. FIG. 1B is a perspective view of a main part. FIG. 8 is a schematic side sectional view of a main part showing a method of manufacturing the key top plate 50. In this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

This embodiment is different from the first embodiment in that the printing layer 23-4 corresponding to the annular printing layer 23 in the first embodiment is made up of a number of dot-like printing points.
This is a point provided from the side wall portion of the curved portion 17 to the outer periphery thereof.

Even if the printing layer 23-4 is configured as described above,
As shown in FIG. 8, the upper and lower dies A and B are intensively tightened at the portion of the printing layer 23-4, and are tightened more strongly than the outer portion thereof. Therefore, the same effects as described in the first embodiment are obtained.

Further, in the case of this embodiment, the printing layer 23-4
Is provided from the side wall portion of the curved portion 17 to the outer periphery thereof. Thus, similarly to the third embodiment, the effect of bleeding air that easily accumulates in the R portion A3 in the cavity A1 of the upper mold A is also exhibited. .

In the above embodiments, various modifications are possible. For example, as shown in FIG. 9A, another print layer is placed on the print layer 23 (the same applies to 23-3 and 23-4). 9 may be printed in one or more layers.
As shown in (b), the print layer 23 (23-2 to 23-
4 may be printed on the back side of the film plate 11 or, as shown in FIG. 9C, another printed layer 27 is formed on the printed layer 23-2 shown in FIG. Alternatively, a plurality of layers may be printed. Also, the print layer 23 shown in FIGS.
Alternatively, another print layer may be provided between 23-2 and the film plate 11.

The point is that a key top plate having a structure in which at least the outer surface of the curved portion of the film plate or the back surface thereof is provided with a printed layer for increasing the thickness of the film plate as compared with the outer portion. Any structure may be used.

[Fifth Embodiment] FIG. 10 is a view showing a portion of a key top 65 of a key top plate 60 according to a fifth embodiment of the present invention. FIG. FIG. 2B is a schematic side sectional view showing a method of manufacturing the key top plate 60, and FIG. 2C is an enlarged sectional view of a portion C in FIG. 2A.

In the key top plate 60, a notch 63 formed of a C-shaped through hole is provided around a portion of the film plate 61 where the key top 65 is formed, and the through hole 63 is formed on the film plate 61. A nameplate 80 is attached so as to cover.

FIG. 11 is a view showing a manufacturing process of the film plate 61. That is, as shown in FIG. 1A, a hot-melt type adhesive layer 71 is printed on the upper surface of a thermoplastic film plate 61. The adhesive layer 71 is applied to all portions of the film plate 61 except for the inner portion of the circle e1, and to the ring-shaped portion 71A in the circle e1. The ring-shaped portion 71A is a portion between the two circles e2 and e3.

Next, as shown in FIG. 5B, a printing layer 73 made of a desired pattern is applied on the film plate 61. The place where the printing layer 73 is printed is indicated by a circle e shown in FIG.
This is the inner part of the circle e4 between 1 and the circle e2.

Then, as shown in FIG. 3C, a portion between the circles e1 and e2 of the film plate 61 is cut out in a C-shape except for the hinge portion 64 to provide a cutout portion 63.

Then, as shown in FIG. 10 (b), the film plate 61 with the name plate 80 attached thereto is sandwiched between the upper and lower dies A and B, and the key top 65 is set in the same manner as in each of the above embodiments. If formed by the method, the key top plate 60 shown in FIG.

By the way, as shown in FIG.
A printing layer 83 and a hot-melt type adhesive layer 81 are printed in advance on the lower surface of the film 0, and the hot-melt type adhesive printed on the film plate 61 when sandwiched by the upper and lower dies A and B. Glued to layer 71. Since the printing layer 73 is provided on the ring-shaped portion 71A made of the same material as the adhesive layer 71, this portion is not bonded to the nameplate 80.

Moreover, the ring-shaped portion 71A is thicker than the surrounding portion by the amount of the printing layer 73 provided thereon. Accordingly, when the ring-shaped portion 71A is held between the upper and lower dies A and B, the ring-shaped portion 71A is almost uniformly and intensively held. Therefore, the ring-shaped portion 71A is not dragged. That is, this embodiment also has the same effects as those described in the above embodiments.

[Sixth Embodiment] FIG. 15 is a view showing a key top 95 of a key top plate 90 according to a sixth embodiment of the present invention. FIG. (B) is a cross-sectional view taken along the line DD in FIG. (A), FIG. (C) is a rear view, and FIG. (D) is a schematic side cross-sectional view showing a method of manufacturing the key top plate 90. .

The key top 95 according to this embodiment is provided with a four-sided portion on the outside of the curved portion 97 of the film plate 91.
Two through holes 98 are provided, and a molding resin 99 is formed in the curved portion 97 and in the upper and lower portions of the through holes 98.

In order to mold the key top 95, as shown in FIG. 15D, cavities E1, E5 and E6 having the same shape as the upper part of the key top 95 (E6 is not shown but E6 is Upper mold E having two
15, a lower mold F having a cavity F1 having the same shape as that of the lower portion of the key top 95, and four through holes 98 (only two are shown in FIG. 15 (d)).
A film plate 91 provided with a printing layer 101 corresponding to the annular printing layer 23 in the first embodiment in the hatched portion of the dotted line shown in FIG.

Then, the film plate 91 is sandwiched between the upper and lower molds E and F, and a pin gate E7 provided on the upper mold E is provided.
, The molten resin is first filled into the cavities E5, F1, and E6, and the upper mold E without any through-holes of the film plate 91 is heated by the heat and pressure of the molten resin. Is deformed and pushed up to bring the film plate 91 into close contact with the inner surface of the cavity E1 of the upper mold E, and also fill the cavity E1 with molten resin and solidify the molten resin. Then, the upper and lower molds E and F are removed.

At this time, a printing layer 101 for increasing the thickness of the film plate 91 is printed in advance on a portion of the film plate 91 sandwiched between the upper and lower molds E and F around the cavity E1 of the upper mold E. Therefore, the upper and lower dies E and F intensively tighten this portion. Therefore, the same effects as described in the first embodiment are obtained.

[0061]

As described above in detail, according to the present invention, when a key top is formed on a film plate, it is easy to prevent a portion around the outside of the curved portion of the film plate from being dragged into the curved portion. It has an excellent effect of not damaging the film plate at that time.

[Brief description of the drawings]

FIG. 1 is a key top plate 10 according to a first embodiment of the present invention.
3A is a schematic side sectional view of a main part, and FIG. 3B is a perspective view of a main part.

FIG. 2 is a schematic side sectional view of a main part showing a method of manufacturing the key top plate 10;

FIG. 3 is a key top plate 30 according to a second embodiment of the present invention.
3A is a schematic side sectional view of a main part, and FIG. 3B is a perspective view of a main part.

FIG. 4 is a schematic side sectional view of a main part showing a method of manufacturing the key top plate 30.

FIG. 5 shows a key top plate 40 according to a third embodiment of the present invention.
3A is a schematic side sectional view of a main part, and FIG. 3B is a perspective view of a main part.

FIG. 6 is a schematic side sectional view of a main part showing a method of manufacturing the key top plate 40.

FIG. 7 shows a key top plate 50 according to a fourth embodiment of the present invention.
3A is a schematic side sectional view of a main part, and FIG. 3B is a perspective view of a main part.

FIG. 8 is a schematic side sectional view of a main part showing a method for manufacturing the key top plate 50.

9 (a), 9 (b), and 9 (c) are schematic cross-sectional side views of a main part showing another embodiment.

FIG. 10 shows a key top plate 6 according to a fifth embodiment of the present invention.
FIG. 7A is a diagram showing a portion of a key top 65 of FIG.
Is a schematic side sectional view of a main part, FIG. 4B is a schematic side sectional view of a main part showing a method of manufacturing the key top plate 60, and FIG. 4C is an enlarged view of a portion C in FIG. .

11 (a) to 11 (c) are views showing a manufacturing process of the film plate 61.

FIG. 12 shows a key top 20 of a conventional key top plate 200;
FIG. 4 is a schematic side sectional view of a main part showing a portion 2;

FIG. 13 is a schematic side sectional view of a main part for describing a method of manufacturing the key top plate 200.

FIG. 14 is a schematic side sectional view of a main part for describing a method of manufacturing the key top plate 200.

FIG. 15 shows a key top plate 9 according to a sixth embodiment of the present invention.
FIG. 7A is a diagram showing a key top 95 portion of FIG.
FIG. 3B is a plan view of a main part, FIG. 4B is a sectional view taken along the line DD in FIG. 4A, FIG. 4C is a rear view, and FIG.
0 is a schematic side cross-sectional view of a main part showing a method of manufacturing the same.

[Explanation of symbols]

10, 30, 40, 50, 60, 90 Key top plate 11 Film plate 15, 35, 45, 55, 65, 95 Key top 17 Curved portion 19 Mold resin 23, 23-2, 23-3, 23-4, 73, 101
Printing layer

Claims (6)

(57) [Claims] 1. A method according to claim 1, further comprising: providing a film plate made of a flexible resin film, wherein a portion of the film plate having no through-hole is curved upward, and at the same time, a molding resin is directly fused into the curved portion. Alternatively, the film plate is adhered through an adhesive layer, or the curved portion is filled with a mold resin, and the molded resin is molded above and below a through hole provided in a portion outside the curved portion of the film plate. A key top plate of a push-button switch having a key top formed by being clamped, wherein at least the outer surface of the curved portion of the film plate or the back surface portion has a print layer thicker than the outer portion thereof. A key top plate for a push button switch, comprising: 2. The printing layer according to claim 1, wherein the printing layer is provided in an annular shape around an outer periphery of the curved portion.
A key top plate of the push button switch according to the description. 3. The method according to claim 1, wherein the printing layer is formed by printing a color / pattern printing layer printed on the front surface or the back surface of the curved portion so as to protrude to the outer periphery of the curved portion. A key top plate for a push button switch according to claim 1. 4. The key top plate for a push button switch according to claim 1, wherein the printing layers are provided at predetermined intervals radially from a side wall portion of the curved portion toward an outer periphery thereof. 5. The printing layer includes a plurality of dot-like printing points,
2. A key top plate for a push button switch according to claim 1, wherein said key top plate is provided by providing from a side wall portion of said curved portion to an outer periphery thereof. 6. An upper mold having a cavity having the same shape as the upper part of the keytop, a lower mold having a cavity having the same shape as the lower part of the keytop, and a film plate, By sandwiching the film plate between the upper mold and the lower mold and injecting the molten resin into a cavity provided in the lower mold, the heat and pressure of the molten resin cause any through-holes in the film plate. A push button switch that deforms and pushes up the non-existing portion to make it closely adhere to the inner surface of the cavity of the upper mold, fills both the cavities of the upper and lower molds with molten resin, and removes the upper and lower molds after the molten resin is solidified. The method for manufacturing a key top plate of the above, wherein the front or back of a portion around the outside of the deformed portion of the film plate,
A method for manufacturing a key top plate of a push button switch, comprising a step of printing a printing layer for increasing the thickness of the film plate as compared with a further outer portion thereof.