JP2002075116A - Cover member for press-button switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easily fixed cover member for a press-button switch of high reliability when arranging a key-top on the cover member. SOLUTION: At least one protruding part 5 is provided at the lower surface of a key-top 3. The protruding part 5 is made to engage, for fixing with a hole 6 provided at a prescribed position of a cover sheet 2, so that the engaging force between the protruding part 5 and the hole 6 is made to fit the key-top 3 to the cover sheet 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover member for a push button switch applied to a cellular phone, a remote controller, a control device, a measuring instrument, a terminal input device, a keyboard for a computer, and the like. And a key top to be used.

[0002]

2. Description of the Related Art As a conventional method of arranging a plurality of key tops on one cover sheet, a method of adhesively fixing a resin key top on a rubber or elastomeric cover sheet or a method disclosed in Japanese Patent Laid-Open No. Japanese Patent Application Laid-Open No. 2000-1100276) discloses a method of bonding a keytop with a release adhesive.

[0003]

However, these methods require an adhesive or a pressure-sensitive adhesive, which is troublesome.

Further, the cover member is provided with a pressing element for pressing an electric contact, and the cover member must be made of a material having high elasticity, rubber, elastomer or the like in order to move the switch up and down. . For this reason, the pressing element is also made of a soft material, and there is a disadvantage that the strength is insufficient for pressing the electrical contacts, or the pressing element is deformed and the touch when pressed is poor. .

In the case of an illuminated key switch, a transparent material must be used for the cover member in order to guide light from a light source disposed under the cover member to the key top. There are some difficulties, and there is a drawback that it is not possible to cope with the case where light is to be guided only to a specific key.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cover member for a push button switch which can be easily fixed when the key top is arranged on the cover member and has high reliability.

[0007]

According to a first aspect of the present invention, at least one projection is provided on a lower surface of a key top, and the projection is provided at a predetermined position on a cover sheet. The key top is fixedly fitted to the cover sheet by a fitting force between the projection and the hole.

According to a second aspect of the present invention, there is provided a pusher for pushing an electric switch structure by pushing the projection to a lower side of the cover sheet through a hole of the cover sheet. It is characterized by being used as

According to a third aspect of the present invention, the projection has a bulging portion for preventing the protrusion from coming off.

The invention according to a fourth aspect is characterized in that the projection has a rotation preventing means.

According to a fifth aspect of the present invention, the projection and the key top are made of a transparent or translucent material,
The projection is a light guide member for guiding light from the lower light source to the key top.

The invention according to claim 6 is characterized in that the cover sheet is made of a light-shielding material that does not substantially transmit light.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

[First Embodiment of the Invention] FIG. 1A shows a cover member for a push button switch according to an embodiment of the present invention.

The cover member 1 for a push button switch includes a cover sheet 2 and a key top 3 fixed to the cover sheet 2.
The projection 5 is fitted and fixed in a hole 6 provided at a predetermined position of the cover sheet 2, and the key top 3 is attached to the cover sheet 2 by a fitting force between the projection 5 and the hole 6. It is stuck to.

The feature of the present invention is that the key top 3
At least one protrusion 5 provided on the back side.

The protrusion 5 penetrates through the hole 6 of the cover sheet 2 and protrudes below the cover sheet 2 and is used as a pressing element for pressing an electric switch structure such as a switch or a click plate (not shown). Is done. As described above, since the protrusion 5 of the key top 3 made of a material having high rigidity can be used for the pressing element, a clear feel can be obtained even when an electric contact or a click plate is pressed, and there is no fear of erroneous operation.

The shape and size of the projection 5 are not particularly limited, and are appropriately determined according to the size of the click plate or the like. Generally, the diameter is about 0.5 to 5 mm and the height is about 0.
It is formed into a column or square column of about 5 to 5 mm, other similar shapes, or a combination shape. FIG. 1B shows an example of a combination shape, which is composed of a large diameter portion 5a at the root and a small diameter portion 5b ahead of the large diameter portion.

It is preferable that the tip of the projection 5 be rounded so as not to cause excessive damage to the switch.

Further, the protrusion 5 penetrating through the cover sheet 2
As shown in FIG. 1 (c), the protrusion 5
It is also possible to provide a bulging portion 4 for preventing slipping off at a portion that penetrates and comes out to the outside.

Further, in order to prevent rotation, it is highly effective to form the protrusion 5 as a prism as a rotation preventing means or to form a partial protrusion on a side surface of a column. Such a shape also has the effect of increasing the fitting strength.

When the projection 5 is fitted into the hole 6, an adhesive or the like may be used to more firmly fix the projection 5 to the cover sheet 2. However, the projection 5 is fixed only by the fitting force. As a result, only the key top 3 can be replaced, and the key top 3 can be used as a replaceable keyboard.

The material of the key top 3 is not particularly limited, but examples of a resin material include ABS resin, PBT resin, and acrylic resin, polycarbonate resin, and AS resin if transparent. A curable resin may be used, or a resin obtained by curing a polyester resin, a polyurethane resin, an acrylic resin, a methacryl resin, a styrene resin, or the like with heat, ultraviolet light, or the like.

In the case of the illuminated key top 2, an injection-molded product using a light-transmitting transparent resin material is preferable. In particular, the projection 5 is preferably made of a transparent or translucent material. It is effective.

In general, a light source for illuminating is arranged below the cover sheet 2, so that the light emitted from the light source normally passes through the cover sheet 2 and reaches the keytop 3. As described above, the cover sheet 2 is often made of rubber or an elastomer, and its light transmittance is often low.

According to the present invention, a highly transparent material such as an acrylic resin, a polycarbonate resin, a polyester resin, or the like can be used for the protruding portion 5, and since the protruding portion 5 is directly connected to the key top 3, the light transmittance is increased. And an effective light guide member for guiding the light of the lower light source to the key top 3.

Further, when it is desired to illuminate only a specific key, the cover sheet 2 is made of a light-shielding opaque material that does not substantially transmit light, and a light source such as an LED is provided only below the keytop 3 to be illuminated. By arranging the keys, an illuminating structure in which light does not leak to an adjacent key can be provided.

As a method of manufacturing the projection 5, if the key top 3 is formed integrally, for example, the projection 5 may be formed before injection molding with a thermoplastic resin. In this case, the key top 3 is often made of the same material.

When decoration such as printing is required on the back side of the key top 3, as shown in FIG. 1 (d), printing 7 is applied to the back side of the key top body 31 which has been made in advance, and is separately molded. The projected portion 5 may be bonded and fixed.

As the cover sheet 2, a cover sheet made of rubber or an elastomer is well known in general, and silicone rubber, urethane, EPD is used as a material.
M rubber or the like is used, but a flexible resin sheet may be used. Since electric switches and click plates are arranged on the back side of the cover sheet 2, they are often formed in an uneven shape.

[Second Embodiment] In the first embodiment, the holes 6 provided in the cover sheet 2 are formed as through holes. However, as shown in FIG. In the case of the second embodiment, the tip of the protrusion 51 is not exposed on the back side of the cover sheet 2, but the contact area between the protrusion 51 and the cover sheet 2 is increased by lengthening the protrusion 51. Therefore, it is possible to increase the fitting force between the two.

[Third Embodiment of the Invention] FIG. 3 has a small projection 52 adjacent to a main projection 5 penetrating the cover sheet 2, and the small projection 52 is provided on the cover sheet 2. It is fitted and fixed in an unpenetrated hole 62. In the third embodiment, it is possible to prevent the key top 3 from rotating with respect to the cover sheet 2.

[Embodiment 4] At least one protrusion 5 is formed on the key top 3, but a plurality of protrusions may be provided as necessary. When a plurality is provided, all the protrusions 5 do not necessarily have to be configured to penetrate the cover sheet 2.

In the case where a plurality is used, the third embodiment
In addition to the case where the rotation of the key top 3 is fixed as described above, the case where the fitting force is increased or the case where the key top 3 is used as a seesaw type key switch can be considered.

FIG. 4 shows an example in the case of using as a seesaw type key switch.

When used as a seesaw type key switch, as shown in FIG. 4A, a long projection 53 is provided at the center of the key top 3, and this long projection 53 is used as a fulcrum of the seesaw movement. , Short projections 5 on both sides
4, 54 are provided facing each other.

In order to use the seesaw type key switch, as shown in FIG. 4 (b), when a finger is pressed on one of the left and right portions deviated from the center of the key top 3, a long projection is formed. The portion 53 comes into contact with the substrate 8 on which the cover sheet 2 is placed, and the short protrusion 54 on the side pressed with a finger is tilted so as to approach the substrate 8 with the position contacting the substrate 8 as a fulcrum. Press the electrical switch structure 9 provided below. The left and right short protrusions 54, 54 are alternately operated to be used as a key switch for realizing separate left and right switch functions.

[0038]

As described above, according to the present invention, at least one protrusion is provided on the lower surface of the key top, and the protrusion is provided at a predetermined position of the cover sheet. And the key top is fixed to the cover sheet by the fitting force, so that the key top can be manufactured more easily than in the case where a conventional adhesive or adhesive is used.

According to the second aspect of the present invention, in addition to the above-described effects, the protrusion projects through the hole of the cover sheet and projects downward from the cover sheet. Since it is configured to be used as a pressing element for pressing a structure, a clear feel can be obtained even when an electric contact or a click plate is pressed, and there is no fear of erroneous operation.

According to the invention described in claim 3, according to claim 2
In addition to the effects described above, the protrusions have bulging portions for preventing removal, so that removal can be prevented and reliability can be improved.

According to the invention described in claim 4, according to claim 1,
In addition to the effects of the first to third aspects, the protrusion is provided with the rotation preventing means, so that the key top can be prevented from rotating.

According to the invention described in claim 5, claim 1 is provided.
In addition to the effects of (4), by forming the protrusion and the keytop from a transparent or translucent material, and forming the protrusion directly connected to the keytop as a light guide member for guiding the light of the lower light source to the keytop, It is an effective light guide having high light transmittance.

According to the invention described in claim 6, according to claim 5,
In addition to the above effects, if the cover sheet is made of a light-shielding material that does not substantially transmit light, and a light source such as an LED is arranged only below the keytop 3 to be illuminated,
Light can be prevented from leaking to adjacent keys.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a cover member for a push button switch according to Embodiment 1 of the present invention, and FIG. 1 (b) is a view showing another example of the shape of the projection in FIG. 1 (a); FIG. 3C is a diagram showing an example in which a protruding portion is provided on the protrusion in FIG. 4A, and FIG. 4D is a diagram showing an example in which printing is performed on the back side of the key top in FIG. .

FIG. 2 is a sectional view of a main part of a cover member for a push button switch according to another embodiment 2 of the present invention.

FIG. 3 is a sectional view of a main part of a cover member for a push button switch according to another embodiment 3 of the present invention.

FIG. 4 is a sectional view of a main part of a cover member for a push button switch according to another embodiment 4 of the present invention, wherein FIG. 4 (a) shows a state before use, and FIG. The state is shown.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 push button switch cover member 2 cover sheet 3 key top 4 bulging portion 5, 51 protrusion 52 small protrusion 53 long protrusion 54 short protrusion 5 a, 5 b large diameter portion, small diameter portion 6, 61 hole 62 hole 7 printing

Claims (6)

[Claims] 1. A key top having at least one projection on a lower surface thereof, said projection being fitted and fixed in a hole provided at a predetermined position of a cover sheet, and said fitting being carried out by a fitting force between said projection and said hole. A cover member for a push button switch, wherein a key top is fixed to a cover sheet. 2. The projection according to claim 1, wherein the projection protrudes downward from the cover sheet through a hole in the cover sheet, and the projection is used as a pressing element for pushing an electrical switch structure. The cover member for a push button switch according to claim 1. 3. The cover member for a push button switch according to claim 2, wherein the protrusion has a bulging portion for preventing the protrusion from coming off. 4. The cover member for a push button switch according to claim 1, wherein said projection has a rotation preventing means. 5. The projection according to claim 1, wherein the projection and the key top are made of a transparent or translucent material, and the projection is a light guide member for guiding light from a lower light source to the key top. Item 5. A cover member for a push button switch according to any one of Items 1 to 4. 6. The cover member for a push button switch according to claim 5, wherein the cover sheet is made of a light-shielding material that does not substantially transmit light.