JP2004014143A - Lighted switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily manufacture a low cost lighted switch providing a good click feeling in addition to uniform illumination from an EL element. <P>SOLUTION: A hemispherical protrusion 2 is formed by ultraviolet curing resin which is adjusted to within a range of 2 to 40Pa s in viscosity. The thin and small sized protrusion is easily formed with the good click feeling by adjusting the height of a projecting part 1 within a range of 0.1 to 1mm. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an illuminated switch used for a mobile phone, a portable information device, a home appliance, an industrial device, or the like.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 9-35571 proposes an illuminated switch in which a projection is formed on a non-light-emitting side surface of an EL sheet composed of an electroluminescence element (hereinafter, referred to as an “EL element”). FIG. 8 shows one embodiment of the present invention. That is, according to the present invention, the switch driving projection 14 is formed on the non-light-emitting side surface of the sheet-like EL element section 15, and when the upper surface of the EL element section is pressed, the tip of the switch driving projection becomes the upper movable contact 21. Is pressed down, and contacts the lower fixed contact 18 to energize. Therefore, since a member or the like that blocks light emission is not formed on the light emitting side surface of the EL element portion 15, uniform illumination can be obtained.
[0003]
[Problems to be solved by the invention]
However, in the above-mentioned conventional example, there is no mention of the specific shape of the switch driving projection 14 or the manufacturing method. The inventor conducted various tests and the like on the switch driving projection 14 (hereinafter referred to as “projection”). As a result, a good click feeling was obtained, and characteristics of the material of the projection that could be easily formed were obtained. And dimensional shape.
[0004]
Therefore, an object of the present invention is to propose an illuminated switch that can obtain a good click feeling in addition to uniform illumination from an EL element and that can be easily manufactured in a thin and small size.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a first feature of the illuminated switch according to the present invention is that an EL sheet, a hemispherical projection formed on a non-light emitting side surface of the EL sheet, and a position facing the projection are provided. The EL sheet has a transparent electrode layer, a light emitting layer, an insulating layer, a back electrode layer, and a protective layer laminated in this order on a transparent substrate. A mold resin having a viscosity of 2 to 40 Pascal-seconds (hereinafter, referred to as “Pa · s”) at room temperature.
[0006]
By configuring the invention in this way, it is possible to obtain an illuminated switch that can provide a good click feeling and is easy to manufacture. That is, in order to improve the operability of the illuminated switch, it is extremely important that when the protrusion is pressed with a finger through the EL sheet, a click feeling that the button is pressed is surely obtained. In order to obtain this click feeling, it is necessary that the projection has sufficient rigidity.
[0007]
By the way, the ultraviolet curable resin is a suitable material for forming the projection, but in order to secure the rigidity of the projection, it is necessary to form the projection having a predetermined height or more. However, when the viscosity of the ultraviolet curable resin is set to less than 2 Pa · s at room temperature, the material easily flows when forming the protrusion, and it is difficult to form a hemispherical protrusion having a predetermined height. It has been found. On the other hand, it was also found that when the viscosity of the ultraviolet curable resin exceeds 40 Pa · s at room temperature, the material is easily solidified and it is difficult to form a hemispherical projection having a smooth surface.
[0008]
Therefore, a hemispherical projection having a predetermined height can be easily formed by using an ultraviolet curable resin for the projection and adjusting the viscosity thereof to 2 to 40 Pa · s.
[0009]
A second feature of the illuminated switch according to the present invention is that the height of the protrusion described in the feature 1 is 0.1 to 1 millimeter (hereinafter, referred to as “mm”).
[0010]
That is, as a result of the experiment, when the protrusions are formed of an ultraviolet-curable resin, if the height of the protrusions is 0.1 mm or more, a good click feeling is obtained, and the viscosity of the ultraviolet-curable resin is reduced to room temperature. It has been found that a hemispherical projection having a height of 0.1 mm or more can be easily formed if the pressure is 2 Pa · s or more below. On the other hand, in order to reduce the size and weight of a mobile phone or the like, it is necessary to make the illumination switch thin and small. For this purpose, it is required that the height of the hemispherical projection is minimized and the diameter is 6 mm or less.
[0011]
However, when a hemispherical projection is formed using an ultraviolet-curable resin having a viscosity of 2 to 40 Pa · s at room temperature, the relationship between the height H and the diameter D is 4H ≦ D ≦ 6H. Was confirmed. Therefore, in order to make the diameter D of the hemispherical projection 6 mm or less, the height H needs to be 1 mm or less from the above relationship 4H ≦ D ≦ 6 mm (= 6H). As described above, by setting the height of the projection to 0.1 to 1 mm, a good click feeling can be obtained, and a thin and small illuminated switch can be easily formed.
[0012]
A third feature of the illuminated switch according to the present invention is that the projection described in any one of the first and second features is formed by screen printing. A fourth feature of the illuminated switch according to the present invention is that the protrusion described in any one of the first and second features is formed by potting.
[0013]
That is, if a hemispherical projection made of an ultraviolet-curable resin having a viscosity of 2 to 40 Pa · s at normal temperature is formed by screen printing or potting, the above relationship 4H ≦ D ≦ 6H can be ensured. A thin and compact illuminated switch having a good click feeling can be easily manufactured.
[0014]
A fifth feature of the illuminated switch according to the present invention resides in that a keytop is attached to a light emitting side surface of the EL sheet described in any one of the features 1 to 4. A sixth feature of the illuminated switch according to the present invention resides in that a keytop is formed integrally with the EL sheet on the light emitting side surface of the EL sheet described in any of the above features 1 to 4. A seventh feature of the illuminated switch according to the present invention resides in that a character and a pattern layer are formed on the light emitting side surface of the EL sheet described in any one of the first to sixth features.
[0015]
An eighth feature of the illuminated switch according to the present invention is that in any one of the features 5 to 6, a character and a picture layer are formed on a surface of the key top. A ninth feature of the illuminated switch according to the present invention is that the keytop described in any one of the above features 5 to 6 has translucency, and a character and a pattern layer are formed on the bottom surface of the keytop. It is in that.
[0016]
By configuring the invention in this manner, a key top that clearly indicates a predetermined pressing position of the illuminated switch, or a character and a pattern layer can be easily formed, without increasing the thickness of the illuminated switch almost. Operability of the illuminated switch can be improved.
[0017]
A tenth feature of the illuminated switch according to the present invention is that the switch sheet described in any one of the above features 1 to 9 is a metal dome sheet. An eleventh feature of the illuminated switch according to the present invention is that the switch sheet described in any one of the above features 1 to 9 is a polymer dome sheet.
[0018]
That is, by configuring the switch sheet in a dome shape, the dome sheet is elastically deformed when the switch sheet is pressed by the tip of the projection. Therefore, since the pressing stroke of the illuminated switch can be secured, the operability is improved. Further, the click feeling can be further improved by the restoring force of the elastic deformation.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The illuminated switch shown in FIG. 1 includes an EL sheet 1 made of an electroluminescent element, a hemispherical projection 2 formed on a non-light emitting side surface 1a of the EL sheet, and a position facing the projection. Switch sheet 3. As shown in FIG. 2, the EL sheet 1 is formed by laminating a transparent electrode layer 12, a light emitting layer 13, an insulating layer 14, a back electrode layer 15, and a protective layer 16 in this order on a film-shaped transparent substrate 11. It is formed.
[0020]
The transparent electrode layer 12 is formed by depositing indium-tin oxide (hereinafter, referred to as “ITO”) on a transparent substrate 11 made of polyethylene terephthalate (hereinafter, referred to as “PET”) having a thickness of 75 μm. The light emitting layer 13 is formed by printing light emitting ink on the upper surface of the transparent electrode layer 12. Note that a luminous body constituting the luminous ink uses zinc sulfide (ZnS) doped with copper. This luminescent ink is produced by mixing and stirring a fluororesin binder obtained by dissolving a copolymer of vinylidene fluoride and propylene hexafluoride in a solvent of methyl ethyl ketone, and the above luminescent material. The light-emitting layer 13 is formed by printing the light-emitting ink on the ITO vapor-deposited surface by a method such as a screen printing method, and then drying by heating.
[0021]
Next, an insulating layer 14 is formed on the light emitting layer 13 by the same means as the light emitting layer. The ink for forming the insulating layer 14 is manufactured by mixing and stirring a high dielectric substance composed of barium titanate (BaTiO ₃ ) and the above-described fluororesin binder. The back electrode layer 15 is formed by printing carbon ink on the insulating layer 14 and drying by heating. This carbon ink is produced by mixing carbon powder with polyester as a binder. The carbon ink may be manufactured by mixing carbon powder, silver powder, and copper powder with polyester as a binder. Finally, a protective layer 16 is formed by printing on the back electrode layer 15. The protective layer 16 may be any material having electrical insulation such as polyester, polyimide or polyvinyl chloride.
[0022]
Next, as shown in FIGS. 1 and 2, the protrusion 2 is screen-printed at a predetermined position on the non-light-emitting side surface 1 a of the EL sheet 1 using an ultraviolet-curable resin, and cured by irradiating ultraviolet rays. Formed by The ultraviolet curable resin includes an acrylic resin, an epoxy resin, a silicon resin and the like, and any of them is applicable. In the embodiment of the present invention, the viscosity of the ultraviolet curable resin before curing is 20 Pa · s at room temperature, and the emulsion thickness for screen printing is 0.4 mm. As a result, a hemispherical projection 2 having a height H of 0.4 mm is formed. The diameter of the hemispherical projection 2 can be formed in the range of 1.6 to 2.4 mm according to the above-described relational expression. By forming the protrusion 2 from the viscosity of the ultraviolet-curable resin and the emulsion thickness set in this manner, when the protrusion is pressed from the light emitting side surface 1b of the EL sheet 1 to a metal dome or a polydome described later. In addition, a good click feeling can be obtained. Further, the thin and small projection 2 can be easily formed. Note that the protrusion 2 is not limited to screen printing, and may be formed by potting.
[0023]
Returning to FIG. 1, the description will be continued. A switch sheet 3 is provided at a position facing the protruding portion 2, and this switch sheet has a dome-shaped bulge upward in FIG. It is formed of a metal dome sheet. The lowermost portion of the switch sheet 3 is a switch board 35. On the switch board, one conductive fixed contact 34 and a pair of conductive fixed contacts 33 sandwiching the conductive fixed contact at the center are provided. , 33 are formed. The pair of conductive fixed contacts 33, 33 are in contact with a circumferential end of a metal dome 32 having a dome shape covering the conductive fixed contact 33, and the metal dome is provided with an adhesive covering the outer surface thereof. It is fixed on the switch board 35 by the PET sheet 31. The vertex of the metal dome 32 is located at a position facing the vertex of the hemispherical projection 2.
[0024]
Therefore, when the light emitting side surface 1b of the EL sheet 1 is pressed with a finger, the top of the projection 2 formed on the non-light emitting side surface 1a of the EL sheet presses and deforms the metal dome 32 downward, and the central conductive fixed contact 34 The contact causes a short circuit with the pair of conductive fixed contacts 33. In this way, an electrical switching operation becomes possible. Further, since the metal dome 32 is elastically deformed, it is possible to secure a pressing stroke of the illuminated switch, thereby improving operability. The click feeling can be further improved by the restoring force of the elastic deformation.
[0025]
FIG. 3 shows a case in which the switch sheet 103 provided at a position facing the protrusion 102 is formed of a polymer dome sheet having a dome-shaped bulging shape on the upper side. That is, a pair of conductive fixed contacts 133 and 134 are formed on the switch substrate 135, and these conductive fixed contacts are covered with a dome-shaped PET sheet 131. The circumferential end of the PET sheet 131 is stuck on the switch substrate 135, and a movable contact 132 is formed on the inner surface of the vertex, and is embossed. The apex of the dome-shaped PET sheet 131 is located at a position facing the apex of the hemispherical projection 102.
[0026]
Therefore, when the light emitting side surface 101b of the EL sheet 101 is pressed with a finger, the vertices of the protrusions 102 formed on the non-light emitting side surface 101a of the EL sheet press and deform the dome-shaped PET sheet 131 downward, and the movable contact 132 By contacting both the conductive fixed contacts 133 and 134, the conductive fixed contacts 133 and 134 are short-circuited. In this way, an electrical switching operation becomes possible. Further, the operability and the click feeling can be improved as described above by elastically deforming the PET sheet 131.
[0027]
The illuminated switch shown in FIG. 4 has a key top 204 adhered to a light emitting side surface 201 b of an EL sheet 201 via a double-sided adhesive tape 205. Note that an adhesive or an adhesive can be used instead of the double-sided adhesive tape 205. In the illuminated switch shown in FIG. 5, a key top 304 is formed integrally with a transparent substrate 311 constituting a light emitting side surface 301b of an EL sheet 301. The double-sided pressure-sensitive adhesive tape 205, the pressure-sensitive adhesive, and the adhesive are preferably transparent in order to improve the distinguishability of the key top 204.
[0028]
The illuminated switch shown in FIG. 6 has a character and picture layer 406 formed on an upper surface of a key top 404 integrally formed on a transparent substrate 411 constituting a light emitting side surface 401b of an EL sheet 401. The illuminated switch shown in FIG. 7 has a key top 504 attached to a light emitting side surface 501b of an EL sheet 501 with a character and picture layer 506 interposed therebetween. The key top 504 is made of a light-transmitting synthetic resin so that the character and picture layer 506 at the bottom of the key top can be seen through.
[0029]
【The invention's effect】
First, by using an ultraviolet curable resin whose viscosity is adjusted to a range of 2 to 40 Pa · s at normal temperature, a hemispherical projection having a predetermined height is formed on the non-light-emitting side of the EL sheet. It can be easily formed. Therefore, it is possible to easily manufacture an illuminated switch capable of obtaining a good click feeling. Second, by adjusting the height of the hemispherical projection to a range of 0.1 to 1 mm, it is possible to easily manufacture a thin and small illuminated switch while securing a predetermined rigidity of the projection. be able to.
[0030]
Third, it is possible to easily form a key top or a character and picture layer that clearly indicates a predetermined position without increasing the thickness of the illuminated switch, thereby improving the operability of the illuminated switch. it can. Fourth, by forming the switch sheet pressed by the protrusion into a dome shape, the elastic deformation of the switch sheet can be used. Therefore, the pressing stroke of the illuminated switch can be secured, so that the operability is improved. Further, the click feeling can be further improved by the restoring force of the elastic deformation.
[Brief description of the drawings]
FIG. 1 is a partially enlarged cross-sectional view of an illuminated switch.
FIG. 2 is a partially enlarged sectional view of an EL sheet.
FIG. 3 is a partially enlarged cross-sectional view of another illuminated switch.
FIG. 4 is a partially enlarged cross-sectional view of another illuminated switch.
FIG. 5 is a partially enlarged sectional view of another illuminated switch.
FIG. 6 is a partially enlarged cross-sectional view of another illuminated switch.
FIG. 7 is a partially enlarged cross-sectional view of another illuminated switch.
FIG. 8 is a partially enlarged sectional view of an illuminated switch according to a conventional example.
[Explanation of symbols]
1, 101-501 EL sheet 1a, 101a Non-light emitting side surface 1b, 101b-501b Light emitting side surface 11, 311, 411 Transparent substrate 12 Transparent electrode layer 13 Light emitting layer 14 Insulating layer 15 Back electrode layer 16 Protective layer 2, 102-502 Projection Part 3, 103 to 503 Switch sheet 31, 131 PET sheet 32, 132 Metal dome (movable contact)
33, 133, conductive fixed contacts 34, 134 conductive fixed contacts 35, 135 switch substrates 204 to 504 key top 205 double-sided adhesive tape 406, 506 character and picture layer

Claims (11)

An EL sheet, a hemispherical protrusion formed on the non-light-emitting side surface of the EL sheet, and a switch sheet disposed at a position facing the protrusion, wherein the EL sheet has a transparent electrode layer on a transparent substrate. A light-emitting switch in which a light-emitting layer, an insulating layer, a back electrode layer, and a protective layer are laminated in this order, wherein the material of the protrusion is an ultraviolet-curable resin and has a viscosity of 2 to 40 Pascal at room temperature. An illuminated switch characterized in seconds. The illuminated switch according to claim 1, wherein the height of the protrusion is 0.1 to 1 millimeter. 3. The illuminated switch according to claim 1, wherein the projection is formed by screen printing. The illuminated switch according to claim 1, wherein the protrusion is formed by potting. The illuminated switch according to any one of claims 1 to 4, wherein a key top is attached to a light emitting side surface of the EL sheet. The illuminated switch according to any one of claims 1 to 4, wherein a key top is formed integrally with the EL sheet on a light emitting side surface of the EL sheet. The illuminated switch according to any one of claims 1 to 6, wherein a character and a picture layer are formed on a light emitting side surface of the EL sheet. The illuminated switch according to any one of claims 5 to 6, wherein a character and a pattern layer are formed on a surface of the key top. The illuminated switch according to any one of claims 5 to 6, wherein the key top has translucency, and a character and a picture layer are formed on a bottom surface of the key top. The illuminated switch according to any one of claims 1 to 9, wherein the switch sheet is a metal dome sheet. The illuminated switch according to any one of claims 1 to 9, wherein the switch sheet is a polymer dome sheet.

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