JP4111607B2 - Illuminated pushbutton switch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illuminated pushbutton switch used for a mobile communication device such as a mobile phone and a car phone, a data input device such as a measurement device, a remote controller, and a handy terminal, a switch device, and the like.
[0002]
[Prior art]
Conventionally, in an illuminated pushbutton switch used in an input device such as a cellular phone, a pushbutton switch cover member a is assembled with a circuit board b and housed in a case as shown in FIG. And the circuit board b constitute a push button switch. Such a pushbutton switch has a plurality of key top portions a ₁ each having a character / symbol display portion a ₂ formed on the top surface on the front surface and a contact portion c corresponding to each key top portion a ₁ on the back surface. When the key top portion a ₁ is pressed, the contact portion c contacts the contact of the circuit board b directly or indirectly through a metal disc spring d, a resin disc spring or the like to open and close the circuit. A number of light sources e such as LEDs, for example, about 10 to 15 are arranged on the circuit board b below the push button switch cover member a, and the key top portion a ₁ is displayed by the light source e during the pressing operation. it has been performed to facilitate their viewing by irradiating a _2.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional illuminated pushbutton switch, it is difficult to uniformly irradiate the display on the top surface of all the key tops, and uneven illumination and uneven brightness cannot be avoided. Since there is a problem that the power consumption increases because the LEDs are turned on at the same time. To eliminate this uneven illumination and brightness, it can be solved by turning on the LED with higher brightness, but this further increases the power consumption. However, the use time of a device such as a mobile phone is shortened, and a large capacity battery pack is indispensable, resulting in a new problem of increasing the weight of the device. In addition, since many of these LEDs are incorporated into the circuit board, there are many limitations in circuit design of the circuit board, increasing design time, and increasing the manufacturing cost, such as the cost of incorporation into the circuit board. there were.
The present invention is intended to solve these conventional drawbacks, and even if the size of the battery pack is reduced by reducing the power consumption and the battery pack etc., the entire cover member for the pushbutton switch can be illuminated uniformly. The display unit can be clearly seen, and the entire switch device can be made thin by using a thin surface-emitting sheet, so that LEDs and the like are not assembled to the circuit board, so that the manufacturing cost including the design of the circuit board is reduced. Therefore, an object of the present invention is to provide an illuminated pushbutton switch that can sufficiently satisfy the demand for cost reduction.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is an upper sheet in which a key top portion is formed on the front surface side, and a lower layer in which a pressing portion provided corresponding to the key top portion is formed on the back surface side. And a push button with a light-shielding layer having a display portion formed corresponding to the key top portion, a light-transmitting colored layer, and a surface-emitting sheet interposed between the upper layer sheet and the lower layer sheet. As a switch cover member, a circuit board provided with a fixed contact corresponding to the pressing portion of the lower layer sheet is provided, and a base film having a portion corresponding to the fixed contact as a window hole is bonded onto the circuit board, A flexible disc spring is placed on the base film so as to cover the fixed contact, and an outer peripheral edge of the metal disc spring is adhered to the base film with a fixed sheet to fix the disc spring, and the lower layer sheet Pressing The result was fixed on the circuit board cover member for the push button switch so as to abut on the disc spring, the disc spring is illuminated push button switch, wherein by white PET.
[0005]
The invention according to claim 2, wherein the key top portion a light emitting portion is formed in a portion of the surface-emitting sheet corresponding to, illumination according to claim 1, characterized by forming an electrode on the light emitting portion It is a type pushbutton switch.
[0008]
[Action]
According to the illuminated pushbutton switch of the present invention, since the thin sheet-like illumination light source is used, the apparatus itself can be thinned, and the entire sheet emits light. There is no light unevenness and there is a high-quality feeling. Furthermore, since it is not necessary to assemble the LED etc. on the circuit board as in the past, the manufacturing cost including the design of the circuit board can be reduced, and the entire sheet emits light with low power, so that the power consumption can be suppressed. Therefore, the battery pack can be reduced in size by reducing the capacity.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an illuminated pushbutton switch according to a first embodiment of the present invention, in which a key top member 2 having a display portion 1 which is a symbol such as a character or a sign is formed on the surface side, and a pressing portion 4 the base portion 4 ₁ and the cover member for push button switch 3 formed on the back side, and a base film 6 having a window hole portion excluding the portion of the fixed contact 9 provided on the circuit board 8 is provided, said base The film 6 is placed on the circuit board 8, the metal disc spring 5 is placed on the base film 6 above the fixed contact 9, and the outer peripheral edge of the metal disc spring is placed on the base film 6 with the surface emitting sheet 7. fixed by bonding, made of the configuration of said surface light-emitting sheet 7 was pressed and fixed by the base portion 4 ₁ of the pushbutton switch cover member 3.
The surface light emitting sheet 7 is a so-called EL (electroluminescence) sheet, in which a light emitting substance such as zinc sulfide is injected between films provided with electrodes and a fluorescence is generated when a voltage is applied. It is what. In this illuminated pushbutton switch, a metal disc spring 5 serving as a movable contact portion is provided opposite to a fixed contact 9 on a circuit board 8 below the pressing portion 4 of the pushbutton switch cover member 3 as shown in FIG. The metal disc spring 5 mounted on the base film 6 is fixed by the surface light emitting sheet 7, and the surface light emitting sheet 7 is fixed so as to cover the whole metal disc spring 5. However, in order not to impair the click feeling of the metal disc spring 5 and the feel when pressed, it is preferable to fix the metal disc spring 5 with the dome-shaped portion removed.
[0010]
Display unit 1 of the pushbutton switch cover member 3, whether the display unit 1 such as open symbols on the top surface of the key top portion 2 of a translucent colored layer 1 ₁ and the light-shielding layer 1 ₂ is formed, or, Although not shown, the display unit 1 for symbols and the like is formed by a method such as printing.
[0011]
In the second embodiment, as shown in FIG. 2, the display unit 1 comprising a light-transmitting colored layer 1 ₁ and the light-shielding layer 1 ₂ which, or the display unit is not shown, and symbols are printed dome key top portion 2 attached to the surface side, and a pressing portion 4 and the base portion 4 ₁ and the cover member 3 for a push button switch which is formed on the back side, above the fixed contact 9 provided on the circuit board 8 having Jo flexible and disc spring 5 ₁ resin sheet 5 ₂ formed with are provided on the circuit board 8. And with each other by providing a conductive contact 5 ₃ on the back surface of the dome-shaped portion, but the flexible disc springs 5 ₁ of a surface-emitting sheet 7 on the resin sheet 5 ₂ other than the dome-shaped portion is provided, the surface emission sheet 7, the pressing load when the cover is also domed portion of the flexible disc spring 5 ₁ increases, because the clicking feeling is impaired, it is preferable to a state of far the dome-shaped portion.
[0012]
Further, in the third embodiment, the push button switch cover member 13 shown in FIG. 3 includes an upper layer sheet 11 having the key top portion 12 formed on the front surface side and a lower layer sheet 15 having the pressing portion 14 formed on the back surface side. It includes a surface emitting sheet 17 between the two sheets of the upper layer sheet 11 and lower sheet 15, there a light-shielding layer 16 ₁ with a light-transmitting colored layer 16 and the display unit 10 as a push button switch member 13 interposed deployed However, the surface emitting sheet 17 may be bonded to the upper layer sheet 11 or the lower layer sheet 15.
Further, the display unit 10 may be provided on the back surface of the key top portion as in the case of FIG. 2, or may be provided on the top surface of the key top portion as shown in FIG. In this case, the light-shielding layer 16 ₁ is only perforated portions corresponding to the display unit 10. Further, the circuit board 18 to which the pushbutton switch cover member 13 is assembled has a base film 26 having a window hole portion excluding the fixed contact 19 as in the example of FIG. the metal disc spring 25 is placed on the base film 26 upward, are bonded and fixed to the metal disc spring outer circumference with fixing sheet 25 _1, but as in the example of FIG. 2 instead of the metal disc spring 25 It may be in the form in which a resin sheet 5 ₂ formed with flexible disc spring 5 ₁ of the dome-shaped.
[0013]
In the example of FIG. 3, although the light emitting portion of the surface - emitting sheet 17 is provided on the entire surface of the cover member for push button switch 13, the light emitting surface emitting sheet 17 as in the fourth embodiment of FIGS. 4 and 5 The portion is formed only on the portion corresponding to the key top portion 12, and only the portion to be illuminated is illuminated by the surface emitting sheet 17. That is, the light emitting unit 17 ₁ corresponding to the key top portion 12 in the surface-emitting sheet 17 is tied to the circuit, the connected to the circuit board 18 via the electrodes 17 _2, only the key top portion 12 is pressed It is configured to be illuminated by control on the circuit board. In this way, the light emitting material of the surface light emitting sheet 17 may be provided in a limited amount only on the key top portion, so that the manufacturing cost can be reduced and the key top portion pressed when the push button switch is pressed. 12 is illuminated, so that the pressed key top portion 12 can be distinguished and confirmed, so that it is easy to understand whether the key top portion 12 is pushed in use, and only the pressed key top portion 12 emits light. In addition, power consumption can be suppressed, which can contribute to reducing the capacity of battery packs and the like.
[0014]
In the fifth embodiment of FIG. 6, to form a display unit 21 such as a symbol on the surface side of the key top member 22, also the key top portion 22 of the pressing portion 24 is formed on the back side with a moving contact 24 _1, A push button switch cover member 23 provided on the base portion 22 ₂ through the dome-shaped portion 22 ₁ is used, and there is a fixed contact 29 provided on the circuit board 28 so as to face the movable contact 24 ₁ . a structure in which a surface emission sheet 27 between the base portion 22 ₂ of the circuit board 28 and the cover member for push button switch 23 with the fixed contact 29. Display unit 21 is shaped similarly to FIG. 1, also the surface emission sheet 27 is preferably set to a state of far the dome-shaped portion 22 ₁ of the pushbutton switch cover member 23.
[0015]
The cover member for the pushbutton switch, the base portion of the upper layer sheet, and the lower layer sheet shown in the figure may be made of various kinds of light-transmitting elastic rubber or heat-based plastic elastomer such as urethane. Considering the properties and weather resistance, silicone rubber is preferable.
[0016]
The key top part is an acrylic, urethane, methacrylic, polyester, polycarbonate, or dimethylphenyl silicone type, and has a translucent and highly transparent high hardness resin with a Shore D hardness of 40 to 80 degrees. Is desirable. The high-hardness resin used as the key top portion needs to be bonded and integrated with the elastic material of the cover member for the push button switch, such as silicone rubber. In addition, as a resin that can ensure translucency and does not turn yellow upon heating, for example, a vinyl monomer as a curing agent and an adhesion-imparting agent to a polyester resin of a thermosetting resin, for imparting mechanical strength improvement and shrinkage prevention functions It is more preferable to select a resin in which an epoxy resin or the like is appropriately blended.
[0017]
The display unit is provided on at least one surface of the top surface of the key top portion, the back bottom surface of the key top portion, the upper layer sheet, and the lower layer sheet. This display section is formed by using light-shielding paint, light-shielding ink, etc. directly by printing at a predetermined position as described above, or once forming a light-shielding colored layer by painting or printing, and then laser processing. For example, a part of the light-shielding colored layer is etched into a shape of a character or the like. In this case, a light-transmitting colored layer may be formed in advance under the light-shielding colored layer by printing or the like. Moreover, it is good also as a display part by sticking the printing sheet printed beforehand etc. on the keytop part top surface with a transparent adhesive etc. FIG. In the case of forming the display portion by printing, for example, a so-called transfer printing method using a flexible plastic film as a carrier may be used.
[0018]
【Example】
Examples of the present invention will be described below.
Example 1
Using a silicone rubber composition KE-1915 (manufactured by Shin-Etsu Chemical Co., Ltd.), a cover material for a pushbutton switch having a key top portion was molded by compression molding using a molding die. Next, solid printing is performed on the top surface of the key top portion using a silicone-based light-transmitting colored paint to form a light-transmitting colored layer. Then, the key top portion top surface portion of the light shielding layer was removed by a conventionally known laser processing machine to form a display portion, which was used as a push button switch cover member.
Next, a metal dome-shaped disc spring (metal disc spring) made by press molding using a thin metal (0.1 mm thick beryl copper) as a material, and a window hole (φ4.5 mm) are formed. The base film (transparent PET film with a thickness of 50 μm) is placed with the top facing upward, and the peripheral edge and the base film are held and fixed with a surface emitting sheet with an adhesive, and this is used as a fixed contact on the circuit board. In addition, the push button switch cover member was installed such that the pressing portion corresponds to the top of the metal disc spring and the base portion corresponds to the surface emitting sheet. When the metal disc spring and pushbutton switch cover member installed on this circuit board were assembled in a case (not shown) and the power was turned on, all the display sections were clearly illuminated and evenly visible.
[0019]
Example 2
A transparent acrylic resin is formed by screen printing on the back side of the key top body obtained by injection molding using a light-shielding ink to form a light-shielding layer with a blank symbol. Further, a light-transmitting ink is formed on the light-shielding layer. Similarly, solid printing was performed to form a light-transmitting colored layer, thereby completing the display portion. Moreover, the elastic sheet provided with the base part and the press part was shape | molded using the silicone rubber compound KE-951U (made by Shin-Etsu Chemical Co., Ltd.). The key top body was adhered to the pressing portion of the elastic sheet with a silicone-based adhesive to obtain a push button switch cover member.
Next, a plurality of contacts are formed by screen printing using a carbon-based conductive ink on a polyethylene terephthalate (PET) sheet, which is a resin sheet. A flexible disc spring having a dome-shaped portion bulging upward on the opposite side was formed. Next, a surface emitting sheet with an adhesive in which the dome-shaped portion of the flexible disc spring was removed in a window hole shape was bonded to the resin sheet.
The flexible disc spring is positioned and installed on the fixed contact of the circuit board, and the push button switch cover member corresponds to the top of the flexible disc spring, and the press portion corresponds to the surface emitting sheet. It was installed to do. When the flexible disc spring and push button switch cover member installed on this circuit board were incorporated in the case and the power was turned on, all the display portions were clearly illuminated and evenly visible. In this case, by forming a dome-shaped flexible disc spring using white PET, the light of the surface emitting sheet is reflected by the white PET, and the light more effectively illuminates the key top portion. I was able to.
[0020]
Example 3
A thermosetting liquid acrylic resin (commercially available product) was filled in the engraved part for forming the key top part of a heated mold and cured by heating to obtain a transparent key top part. In addition, by filling silicone rubber compound KE-941U (manufactured by Shin-Etsu Chemical Co., Ltd.) into the same mold as the key top part and pressurizing and heating, the transparent key top part and the elastic sheet part are integrated. It was. Next, a silicone-based light-shielding colored paint is used, a light-shielding layer of a blank symbol is formed on the back surface of the elastic sheet portion by screen printing, and a silicone-based light-transmissive colored material is sufficiently covered so as to sufficiently cover the blank symbol portion. The same printing was performed to obtain an upper layer sheet. The lower layer sheet | seat provided with the press part was similarly shape | molded using the silicone rubber raw material used for preparation of the said elastic sheet part. When this lower layer sheet is colored white or the like with good light reflection efficiency, light can be guided to the upper layer sheet more effectively. The upper layer sheet and the lower layer sheet were bonded so that the key top portion and the pressing portion corresponded to each other through a surface emitting sheet having an adhesive on both sides.
The contact part used the metal disc spring used as the fixing film with an adhesive instead of the surface emitting sheet with the adhesive of Example 1. Needless to say, a dome-shaped flexible disc spring formed by bulging a part of the resin sheet used in Example 2 may be used for this contact portion.
The metal disc spring was positioned and installed at the fixed contact of the circuit board, and the push button switch cover member was installed so that the pressing portion corresponded to the top of the metal disc spring. When the metal disc spring and the push button switch cover member installed on the circuit board were assembled in the case and the power was turned on, all the display portions were clearly illuminated with no unevenness and could be seen well.
[0021]
Example 4
As in Example 3, an upper layer sheet having a key top portion and a lower layer sheet having a pressing portion are formed, and a surface emitting sheet that emits light only at a portion corresponding to the key top portion is interposed between the upper and lower layer sheets. A cover member for a push button switch was provided by bonding.
In addition, the key top part is selected when the cover member for the push button switch is installed on the circuit board provided with the metal disc spring and the fixed contact so that the pressing part corresponds to the top part of the metal disc spring and is installed in the case and the power is turned on. When is pressed, only the pressed key top portion is illuminated by the light emitting portion of the surface light emitting sheet, the identification confirmation is easy, the power consumption is not wasted, and the display portion can be seen well.
[0022]
Example 5
Using a silicone rubber composition KE-1915 (manufactured by Shin-Etsu Chemical Co., Ltd.), compression molding is performed with a molding die, and a key top portion, a dome portion, a base portion, and a pressing portion are formed. A cover member for a push button switch provided with a movable contact was formed using a conductive ink. Next, a display portion such as a symbol was printed on the top surface of the cover member for the push button switch using a silicone-based colored paint to complete the cover member for the push button switch.
Align the fixed contact of the circuit board, install the surface emitting sheet extracted in the window hole except for the fixed contact part on the circuit board, and the push button switch cover member corresponds to the fixed contact It was installed to do. When the surface emitting sheet and the pushbutton switch cover member installed on the circuit board were assembled in the case and the power was turned on, all the key top portions were illuminated clearly and uniformly, and the display portion could be visually confirmed.
[0023]
【The invention's effect】
As described above, according to the illuminated pushbutton switch of the present invention, the power consumption can be reduced, and the entire pushbutton switch member can be illuminated evenly even if the battery pack or the like is reduced in size and reduced in size. The parts can be clearly seen, and since a thin surface emitting sheet is used, LEDs and the like are not assembled to the circuit board, so that the entire switch device can be made thin, and the manufacturing cost including the circuit board design can be reduced. Reduction can be achieved.
[Brief description of the drawings]
FIG. 1 is an enlarged vertical sectional view of a part of an illuminated pushbutton switch according to a first embodiment of the present invention.
FIG. 2 is an enlarged vertical sectional view of a part of an illuminated pushbutton switch according to a second embodiment of the present invention.
FIG. 3 is an enlarged vertical sectional view of a part of an illuminated pushbutton switch according to a third embodiment of the present invention.
FIG. 4 is an enlarged vertical sectional view of a part of an illuminated pushbutton switch according to a fourth embodiment of the present invention.
5 is an overall plan view of the usage state along the line AA in the example of FIG. 4; FIG.
FIG. 6 is an enlarged vertical sectional view of a part of an illuminated pushbutton switch according to a fifth embodiment of the present invention.
FIG. 7 is an enlarged vertical sectional view of a part of a conventional illuminated pushbutton switch.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Display part 1 ₁ Translucent colored layer 1 ₂ Light-shielding layer ₂ , 12, 22 Key top part 3, 13, 23 Push button switch cover member 4, _14, 24 Press part 4 ₁ Base part 5 Metal disc spring 5 ₁ Flexible disc spring 5 ₂ Resin sheet 5 ₃ Conductive contact 6 Base film 7, 17, 27 Surface emitting sheet 8, 18, 28 Circuit board 9, 19, 29 Fixed contact 11 Upper layer sheet 15 Lower layer sheet 16 Translucent coloring Layer 16 ₁ Light-shielding layer 17 ₁ Light emitting portion 17 ₂ Electrode 22 ₁ Dome-shaped portion 24 ₁ Movable contact 25 ₁ Fixed sheet 26 Base film

Claims (2)

An upper layer sheet having a key top portion formed on the front surface side, and a lower layer sheet having a pressing portion provided corresponding to the key top portion formed on the back surface side, between both sheets of the upper layer sheet and the lower layer sheet, A cover member for a pushbutton switch is formed by interposing a light-shielding layer having a display portion corresponding to the key top portion, a light-transmitting colored layer, and a surface emitting sheet, and fixing corresponding to the pressing portion of the lower layer sheet A circuit board having a contact is provided, and a base film having a window hole portion corresponding to the fixed contact is bonded onto the circuit board, and a flexible dish is formed on the base film so as to cover the fixed contact. The push button switch is mounted so that a spring is placed, the outer peripheral edge of the metal disc spring is adhered to the base film with a fixed sheet, the disc spring is fixed, and the pressing portion of the lower layer sheet is brought into contact with the disc spring. Becomes securing the cover member to the circuit board, illuminated push button switch said disc spring is characterized in that by a white PET. 2. The illuminated pushbutton switch according to claim 1 , wherein a light emitting portion is formed on a portion of the surface emitting sheet corresponding to the key top portion, and an electrode is formed on the light emitting portion.

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