JP3345752B2 - Manufacturing method of key top plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a key top plate in which a plurality of key tops for a push button switch are provided on a single film plate.

[0002]

2. Description of the Related Art Conventionally, a key top plate having a large number of key tops formed on a single resin film plate has been used.
FIG. 6 is an exploded perspective view showing a push button switch plate formed using a conventional key top plate of this type.

As shown in FIG. 1, the push-button switch has a key top plate 80 mounted on a hard switch substrate 95,
An outer case 90 is mounted thereon.
Here, the key top plate 80 is formed by molding a number of key tops 83 in a flexible film plate 81.

When the key top 83 exposed from the through hole 91 of the outer case 90 is pressed with a finger, the movable contact 97 is pressed by the key top 83 and turned on.

[0005] By the way, in an electronic device, an outer case 90 is provided.
There are those in which the surface shape is curved in a convex or concave shape.

FIG. 7 is a schematic side sectional view showing a push button switch plate when the outer case 90 is curved in a convex shape. As shown in the figure, when the exterior case 90 is curved, the key top plate 80 is also curved in accordance with this. Since the key top plate 80 is flexible, even if the surface of the outer case 90 is curved, the key top plate 80 can easily be curved in response to this. Reference numeral 85 denotes a spacer for bringing the key top plate 80 into close contact with the lower surface of the outer case 90 in a curved state.

[0007]

However, FIG.
In the conventional example shown in FIG. 5, the key tops 83 on the left and right sides are also inclined with the curvature of the key top plate 80. For this reason,
There were the following problems.

When the push-button switch plate is viewed from above the outer case 90, the portion of the outer peripheral side surface 84 of the left and right key tops 83 becomes easily visible in the through hole 91 of the outer case 90, The aesthetics of the board will be impaired.

The center axis 83a of the inclined key top 83 is inclined obliquely.
Is the direction of the central axis 83a. That is, the pressing direction of each key top 83 is different, and it becomes difficult for the operator to perform the pressing operation.

The present invention has been made in view of the above points, and has as its object the object of the present invention, even when the key top plate is mounted on the back side of the case in a curved state. It is an object of the present invention to provide a method of manufacturing a key top plate in which portions are hard to be seen from the upper side of the case so that the appearance is not impaired, and the key tops are pressed in the same direction and the operator can easily operate.

[0011]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is directed to a curved surface of a case in which a plurality of key tops are molded in a film plate made of a flexible resin film and curved. In a method for manufacturing a key top plate of a push button switch having a structure attached to the case in a curved state according to a shape, a curved surface similar to the curved shape of the key top plate is provided and a key top is formed on the curved surface. An upper mold that is provided with a concave portion and the inner peripheral side surface of the concave portion is linearly oriented in a direction of pressing each key top,
Prepare a lower mold having a curved surface similar to the curved shape of the key top plate, sandwich the film plate between the upper mold and the lower mold, and then melt from the lower mold side. By press-fitting the mold resin, the part located in the concave part provided in the upper mold of the film plate is stretched and pushed up while deforming to make it closely adhere to the inner surface of the concave part provided in the upper mold, and at the same time, the melt mold A key top is formed by filling a resin, and after cooling, the upper die and the lower die are separated in a direction of pressing each key top, and a key top plate is taken out. Further, the present invention provides a structure in which a plurality of key tops are molded in a film plate made of a flexible resin film, and the key tops are attached to the case in a curved state in accordance with the curved surface shape of the case. In the method for manufacturing a key top plate of a push button switch, a curved surface similar to the curved shape of the key top plate is provided, a concave portion for forming a key top is provided on the curved surface, and an inner peripheral side surface of the concave portion is formed by each key top. Prepare an upper mold that is oriented straight in the direction of pressing and a lower mold that is provided with a curved surface similar to the curved shape of the key top plate, and preform the shape of the key top in advance. The prepared film plate is sandwiched between the upper mold and the lower mold, and then the molten mold resin is filled in the recess to form a key top, and after cooling, the upper mold and the lower mold are separated. Key top Pressure and pulled away in the direction, characterized in that it retrieve the key top plate.

[0012]

The key top plate can be manufactured so that even if it is attached to the case in a curved state, the side portion of each key top exposed from the hole of the case is difficult to see from the upper side, and a good appearance can be maintained. Moreover, since the pressing direction of each key top can be the same direction, the operator can press any key top from the same direction, and can manufacture a key top plate that facilitates the operation.

[0013]

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 plate 10 according to a first embodiment of the present invention. FIG. 1 (a) is a plan view, FIG. 1 (b) is a sectional view taken along line EE of FIG. FIG. 3C is a sectional view taken along line FF of FIG.

FIG. 1 shows a state in which the key top plate 10 is curved in the width direction as shown in FIG. 1C in accordance with the curved shape of the outer case 20 described below. Note that, since the film plate 11 constituting the key top plate 10 is actually flexible, this curved shape is not maintained unless it is supported by any supporting member or the like.

As shown in FIG.
Comprises a film plate 11 made of a thermoplastic synthetic resin film having flexibility (for example, polyethylene terephthalate, polyethylene naphthalate, etc.), and a plurality of film plates 11 are provided in the longitudinal and width directions of the surface of the film plate 11, respectively. Each key top 13 is attached.

Here, each key top 13 is attached to the film plate 1.
1 is bent upward and at the same time
The curved portion 12 and the mold resin 15 are directly welded and integrated by filling and solidifying the mold resin 15 in the lower surface side concave portion of the second. Reference numeral 16 denotes a pressing portion of the key top 13.

In the present invention, as shown in FIG. 1C, the key top plate 10 is
In the state where it is curved in the width direction according to the shape of
The outer peripheral side surface 131 (including the outer peripheral side surface of the pressing portion 16) of each key top 13 is formed so as to face the vertical up and down direction (that is, the direction of pressing each key top 13).
Therefore, the shape of the key top 13 at the center and the shape of the key tops 13 at the left and right sides are different from each other. Each pressing portion 16 is formed to have a different length so that the lower end surface thereof is located on the same plane when the key top plate 10 is curved.

On the other hand, in this embodiment, as shown in FIG. 1B, the height of each key top 13 in the vertical direction of the key top plate 10 is made different. That is, the height L1 of the central key top 13 is reduced, and is increased toward the upper and lower sides, and the height L2 of the uppermost and lower key tops 13 is maximized.

Next, FIG. 2 is a diagram showing a push button switch plate constituted by attaching the key top plate 10 and the switch substrate 30 to the back side of the outer case 20, and FIG. 2 (a) is a plan view and FIG. FIG. 2B is a sectional view taken along line KK of FIG. 2A, and FIG. 2C is a sectional view taken along line LL of FIG.

As shown in FIG. 1, the outer case 20 is curved convexly in the width direction and concavely curved in the vertical direction. The outer case 20 is provided with a through hole 21 at a position facing each of the key tops 13. Incidentally, the inner peripheral side surface 211 of the through hole 21 is also formed so as to face the vertical up and down direction (that is, the direction in which each key top 13 is pressed). On the other hand, four projections 23 project from four corners of the lower surface of the outer case 20.

Next, the switch substrate 30 is configured by providing a large number of switch contacts on a flat rigid substrate, and attaching a metal dome-shaped movable contact 33 on each of the switch contacts. Each movable contact 33 is provided at a position facing the pressing portion 16 of each key top 13.

In order to assemble these components, first, the key top plate 10 is attached to the back side of the outer case 20 so as to be in close contact therewith. At this time, the protrusion 23 of the outer case 20 is inserted into the hole 17 provided in the key top plate 10 (see FIG. 1A). In this state, each key top 13 is attached to the outer case 20.
Is exposed to the surface from each of the through holes 21.

Next, a frame spacer 25 is mounted on the back side of the key top plate 10, and a switch substrate 30 is further mounted on the back side. At this time, the protrusion 2 of the outer case 20
3 is inserted into a hole 35 (see FIG. 2 (b)) provided in the switch board 30 and its tip is heat-steamed, whereby these members are integrally fixed. As a result, the outer periphery of the key top plate 10 is surrounded by the outer case 2 by the frame spacer 25.
Since the key top plate 10 is pressed against the back surface of the outer case 20, the key top plate 10 comes into close contact with the back surface of the outer case 20 in a curved state. Further, each pressing portion 16 contacts or approaches each movable contact 33. When each key top 13 is pressed, the pressing portion 16 inverts the movable contact 33 and turns on the switch.

In the present invention, as shown in FIG. 2, the outer peripheral side surface 1 of each key top 13 of the key top plate 10 is provided.
Since each of the push buttons 31 is linearly oriented vertically and vertically, when the push button switch is viewed from directly above, the outer peripheral side surface 131 of each key top 13 is hardly visible in each through hole 21 of the outer case 20. . Therefore, the appearance is not spoiled.

Moreover, the key top 13 including the pressing portion 16
Since the entire outer peripheral side surface 131 is formed such that all of the key tops 10 face the vertical up and down direction in a state where the key top plate 10 is curved, the pressing direction of each key top 13 is the same direction in the vertical up and down direction, The operator can easily press any of the key tops 13.

In the case of this embodiment, the height of each key top 13 is changed corresponding to the outer case 20 which is curved concavely in the vertical direction.
That is, according to this embodiment, the key top plate 10 which can easily cope with the outer case 20 having concave and convex shapes in the vertical and horizontal directions.
Can be provided.

FIG. 4 is a schematic sectional side view for explaining a method of manufacturing the key top plate 10. As shown in FIG. As shown in the figure, the film plate 11 is connected to an upper mold 200 and a lower mold 2.
Insert between 50.

Here, the upper mold 200 has a curved surface 201 similar to the curved shape of the key top plate 10 and is formed in a gentle concave shape as a whole.
Is provided with a concave portion 203 for forming the key top 13.

On the other hand, the lower mold 250 is provided with the key top plate 1.
A curved surface 251 similar to the curved shape of 0 has a gently convex shape as a whole, and a concave portion 253 for forming the pressing portion 16 of the key top 13 is provided in the curved surface 251. ing. Further, a pin gate 255 is connected to the concave portion 253.

Then, if a thermoplastic molten mold resin (for example, a polycarbonate resin) is press-fitted from the pin gate 255 at a high temperature and a high pressure, the portion of the film plate 11 located in the concave portion 203 is pushed up while being stretched by heat and pressure. The curved portion 12 is formed in close contact with the inner surface of the concave portion 203 as shown by a dotted line, and the concave portion 203 and the concave portion 253 are simultaneously filled with the molten mold resin.

By the way, as described above, the resin film is heated at a high temperature.
If the high-pressure and high-pressure mold resin is brought into contact with the resin film while being stretched in a high-pressure state, the resin film and the mold resin can be firmly fused together without using any adhesive. It has been found by various experiments. Accordingly, the curved portion 12 of the film plate 11 and the press-fitted mold resin 15 are firmly fused without any adhesive and are not separated. Of course, they may be bonded using an adhesive.

When the upper and lower dies 200 and 250 are removed after cooling, the key top plate 10 shown in FIG. 1 is completed.

In the present invention, the outer peripheral side surface 131 of the entire key top 13 including the pressing portion 16 is formed such that the key top plate 10 is curved and all of the outer peripheral side surfaces 131 are directed straight in the vertical and vertical directions. , Upper and lower mold 200,2
The inner peripheral side surfaces of the concave portions 203 and 253 provided in the vertical direction also linearly turn in the vertical and vertical directions. Therefore, when removing the upper and lower molds 200 and 250, the two molds 200 and 250 need only be separated vertically. That is, the structure of the upper and lower molds 200 and 250 for manufacturing the key top plate 10 can be simplified.

Alternatively, the key top plate 10 may be manufactured by preforming only the film plate 11 into the shape of the key top 13 and then molding the mold resin 15 in the curved portion in a later step.

FIG. 3A is a plan view showing a key top plate 10 'according to a second embodiment of the present invention.
FIG. 3B is a schematic side sectional view of a push button switch plate constituted by using the key top plate 10 ′ (a portion corresponding to a cross section taken along line MM in FIG. 3A). This key top plate 10 '
In the figure, the same parts as those of the key top plate 10 are denoted by the same reference numerals.

The key top plate 10 'shown in FIG. 3A is different from the key top plate 10 in that one key top plate 10' is divided into two parts so that one key top plate 10 ' This is the only cut-out point except for the connecting portion 49.

On the other hand, as shown in FIG. 3B, the outer case 20 'is bent at a bending position P substantially at the center. The bending position P is located at a position facing the connecting portion 49 of the key top plate 10 '.

When this push button switch plate is assembled,
The key top plate 10 'is bent at the bending position P of the outer case 20'. However, since the key top plate 10 'at the bending position P is connected only by the connecting portion 49, the key top plate 10' Board 1
Even if the whole 0 'is curved in the width direction, it can be easily bent. That is, it can easily cope with an outer case having a surface shape that is curved in one direction and bent in the other direction.

In this embodiment, an example in which the key top plate 10 'is bent in two at the connecting portion 49 has been described.
0 'may be bent at a plurality of positions. Further, the number of connecting portions 49 provided at one place may be plural instead of one.

The key tops 13 of the key top plates 10 and 10 'shown in the first and second embodiments have a structure in which no holes are provided in the film plate 11, and the present invention has such a structure. The key top 13 is not limited to the key top 13 described above, but may be any key top having a structure in which a plurality of key tops are formed on a film plate by molding. That is, for example, a through hole 51 is provided in a film plate 11 "like a key top plate 10" shown in FIG.
Key top 13 "so as to cover the through hole 51 above and below 1
Various deformations are possible, for example, a structure for molding the same.

In short, the shape of the outer peripheral side surface of each key top is formed in a state where the key top plate is curved and all of the key tops are linearly directed in the same direction toward the direction in which each key top is pressed. Any structure may be used.

[0042]

As described in detail above, the key top plate according to the present invention has the following excellent effects. Even if it is attached to the case in a curved state,
A side portion of each key top exposed from the hole of the case is difficult to see from the upper side, and a key top plate that can maintain a good appearance can be manufactured.

Since the direction in which each keytop is pressed is the same direction, a keytop plate that can be easily pressed by the operator can be manufactured.

[Brief description of the drawings]

FIG. 1 is a key top plate 10 according to a first embodiment of the present invention.
FIGS. 3A and 3B are plan views, FIG. 3B is a cross-sectional view taken along line E-E of FIG. 3A, and FIG.
It is -F sectional drawing.

FIGS. 2A and 2B are diagrams showing a push button switch plate configured using a key top plate 10, wherein FIG. 2A is a plan view and FIG.
Is a sectional view taken along the line KK of FIG. 2A, and FIG.
It is LL sectional drawing of.

FIG. 3A is a plan view showing a key top plate 10 'according to a second embodiment of the present invention, and FIG. 3B is a push button switch formed using the key top plate 10'. It is a schematic side sectional view of a board.

FIG. 4 is a schematic side sectional view for explaining a method of manufacturing the key top plate 10.

FIG. 5 is a side sectional view showing a key top plate 10 ″ using a key top 13 ″ having another structure.

FIG. 6 is an exploded perspective view showing a push button switch plate formed using a conventional key top plate.

FIG. 7 is a schematic side sectional view showing a push button switch plate when the outer case 90 is curved.

[Explanation of symbols]

 10, 10 ', 10 "key top plate 11 film plate 13, 13" key top 131 outer peripheral side surface 20, 20' outer case (case) 30 switch board 49 connecting portion

Continuation of the front page (56) References JP-A-4-329228 (JP, A) JP-A-6-44859 (JP, A) JP-A-6-267369 (JP, A) JP-A-7-302526 (JP, A) JP-A-8-7698 (JP, A) JP-A-5-300210 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 13/70 H01H 13/14

Claims (2)

(57) [Claims] 1. A structure in which a plurality of key tops are molded in a film plate made of a flexible resin film and attached to the case in a curved state in accordance with the curved surface shape of the case. In the method for manufacturing a key top plate of a push button switch, a curved surface similar to the curved shape of the key top plate is provided, a concave portion for forming a key top is provided on the curved surface, and an inner peripheral side surface of the concave portion is formed by each key top. An upper mold and a lower mold having a curved surface similar to the curved shape of the key top plate are prepared, and the upper mold and the lower mold are provided. Then, the film plate is sandwiched in between, and then the molten mold resin is press-fitted from the lower mold side to push up while deforming the portion located in the concave portion provided in the upper mold of the film plate, thereby deforming the upper metal plate. Type At the same time, the key top is formed by filling the molten mold resin into the recess and forming the key top.After cooling, the upper die and lower die are separated in the direction of pressing each key top, and the key top plate is separated. A method for manufacturing a key top plate, comprising taking out the key top plate. 2. A structure in which a plurality of key tops are molded in a film plate made of a flexible resin film, and attached to the case in a curved state in accordance with a curved surface shape of the case. In the method for manufacturing a key top plate of a push button switch, a curved surface similar to the curved shape of the key top plate is provided, a concave portion for forming a key top is provided on the curved surface, and an inner peripheral side surface of the concave portion is formed by each key top. An upper mold that is oriented linearly in the direction of pressing and a lower mold that is provided with a curved surface similar to the curved shape of the key top plate are prepared, and the shape of the key top is preformed in advance. The film plate is sandwiched between the upper mold and the lower mold, and then the molten resin is filled in the recess to form a key top. After cooling, the upper mold and the lower mold are separated. Key top Method for producing a keytop plate, characterized in that retrieving the key top plate pulled away in the direction of pressing.