JP4713294B2 - key pad - Google Patents

Description

  The present invention relates to a keypad used for an input device of an electronic device.

Conventionally, a keypad provided with a plurality of key bodies on an electroluminescence sheet (hereinafter referred to as EL sheet) is known. The EL sheet is provided with a base sheet and a plurality of light emitting portions that are spaced from each other on the sheet surface of the base sheet. Then, the key body is bonded to the EL sheet corresponding to the light emitting portion, so that the entire key body or characters on the key body portion are illuminated (for example, see Patent Document 1). The keypad is incorporated in the housing of the input device together with the circuit board provided with the contact switch. In the input device, the contact point switch is connected by pressing the key body. In such a keypad, since a plurality of key bodies are connected via a base sheet, a key body adjacent to the key body also follows the base sheet by a pressing operation of a specific key body. And move. Thus, it is disclosed that a tracking operation of adjacent key bodies is suppressed by forming a slit in a base sheet positioned between adjacent key bodies (see Patent Document 2, paragraph [0027]).
JP-A-2005-85582 JP 2004-193060 A

  On the other hand, the keypad is required to protect the circuit board mounted in the housing. Therefore, the keypad is incorporated in the casing so as to block the outside of the casing and the circuit board housing portion in the casing. The base sheet of the keypad suppresses entry of moisture, dust, etc. into the housing.

  In the keypad, when the slit penetrating the base material sheet is formed, unnecessary follow-up operation of the key body adjacent to the pressed key body can be suppressed. For this reason, when the key is pressed, the load is reduced, so that a good operational feeling can be obtained. However, the formation of the slit in the base material sheet allows an unnecessary object such as moisture and dust to enter the circuit board housing portion through the slit.

  The present invention has been made in view of such a conventional situation, and an object of the present invention is to suppress both unnecessary follow-up operation of adjacent key bodies and intrusion of unnecessary objects into the circuit board housing portion. It is to provide a keypad that can be used.

In order to achieve the above object, the invention according to claim 1 is an electroluminescence sheet in which a plurality of light emitting portions are disposed on a sheet surface of a base sheet having translucency, and the plurality of light emitting elements. A keypad that is incorporated in the housing and used so as to shut off the outside of the housing and the circuit board housing portion in the housing. In addition, a slit that penetrates the base material sheet along the thickness direction is formed in the base material sheet between the adjacent light emitting units, and the slit is sealed by a sealing member. cage, sealing member, the order to be deformed by the displacement of the base sheet with the pressing operation of the key body, formed by a low elastic material elastic modulus than the material constituting the base sheet It becomes, and summarized in that the sealing member to the inner surface of the housing is incorporated in the housing in close contact.

  The invention according to claim 2 is the keypad according to claim 1, wherein the elastic modulus of the elastic material constituting the sealing member is 1/10 of the elastic modulus of the material constituting the base sheet. The gist is 1 / 10,000.

The gist of the invention described in claim 3 is that, in the keypad according to claim 1 or 2, the sealing member is filled in the slit.
According to a fourth aspect of the present invention, in the keypad according to the third aspect, the sealing member is formed to be thicker than the base sheet, and the peripheral portion of the slit is surrounded by the sealing member. It is a summary.

  According to a fifth aspect of the present invention, in the keypad according to any one of the first to fourth aspects, the sealing member is formed thicker than the thickness of the base sheet, and the sealing thereof The gist is that the member is brought into close contact with the inner surface of the casing and incorporated into the casing.

  According to the present invention, it is possible to suppress both an unnecessary follow-up operation of adjacent key bodies and an intrusion of unnecessary objects into the circuit board housing portion.

Hereinafter, an embodiment of the present invention will be described in detail.
The keypad according to the present embodiment is used by being assembled to the casing 52 of the mobile phone 51 as an input key portion of the mobile phone 51 shown in FIG. As shown in FIG. 2, the keypad 11 includes an electroluminescence sheet (EL sheet 12) and a plurality of key bodies 13.

  In the EL sheet 12, a plurality of light emitting portions 15 are spaced from each other on the surface of a base sheet 14 having translucency. The plurality of key bodies 13 are bonded to the base sheet 14 corresponding to the light emitting portions 15. Each light emitting unit 15 is provided on the lower surface of the base sheet 14, and each key body 13 is provided on the upper surface of the base sheet 14 corresponding to each light emitting unit 15. Is illuminated. Furthermore, a compensation electrode 16 a for applying a voltage to the light emitting unit 15 is laid on the base sheet 14. The light emitting portion 15 and the compensation electrode 16a are covered with an insulating resist 17.

  The keypad 11 is provided in the housing 52 so that no gap is generated between the peripheral edge of the base sheet 14 and the inner surface of the housing 52. A circuit board 53 is disposed in the housing 52 below the keypad 11. A region surrounded by the keypad 11 and the housing 52 constitutes a housing portion 54 of the circuit board portion and is isolated from the outside of the housing 52. On the circuit board 53, a plurality of contact switches SW are provided corresponding to the key body 13 and the light emitting unit 15. Each contact switch SW is pressed through the light emitting unit 15 in accordance with the pressing operation of the corresponding key body 13. In this embodiment, the contact switch SW provided with a disc spring is employed, but other contact switches such as a membrane switch may be employed.

  The substrate sheet 14 of the EL sheet 12 protects the light emitting unit 15 and the compensation electrode 16a. The shape of the base material sheet 14 is appropriately set according to the internal shape of the housing 52, and in the present embodiment, has a quadrangular shape as shown in FIG. The material of the base sheet 14 is not particularly limited as long as it has translucency and has a sufficient elastic modulus to protect the light emitting portion 15 and the compensation electrode 16a. The translucency in this specification refers to the property of transmitting visible light emitted by the light emitting unit 15. The elastic modulus of the base material sheet 14 is preferably 1000 to 100,000 MPa. If the elastic modulus of the base sheet 14 is less than 1000 MPa, the protective function of the light emitting portion 15 and the like may not be sufficiently obtained. On the other hand, when the elastic modulus of the base material sheet 14 exceeds 100,000 MPa, the operability of the key body 13 may be reduced when the key body 13 is pressed. This elastic modulus indicates an elastic modulus based on ASTM D882-64T, which is a standard of the American Society for Testing Materials.

  The thickness of the base material sheet 14 becomes like this. Preferably it is 10-150 micrometers, More preferably, it is 15-140 micrometers, More preferably, it is 20-130 micrometers. If the thickness of the base sheet 14 is less than 10 μm, the light-emitting portion 15 and the wiring protection function may not be sufficiently obtained. When the thickness of the base sheet 14 exceeds 150 μm, there is a possibility that the weight reduction of the key body 13 may be hindered.

  As the base sheet 14, a resin film is suitably used from the viewpoint that it has excellent functionality and is easily available. Specific examples of the resin film include a polyester film, a polycarbonate film, a polyamide film, and a polyurethane film. Furthermore, as a resin film, a stretched film is preferable and a biaxially stretched film is more preferable from the viewpoint that the elastic modulus is high and the protective function of the light emitting unit 15 and the wiring is easily obtained.

  The base material sheet 14 is provided with light emitting portions 15 having a rectangular shape in rows and columns, and the base material sheet 14 positioned between the light emitting portions 15 has a base along the thickness direction. A plurality of slits 14 a penetrating the material sheet 14 are formed. Each slit 14 a is formed to extend along the outer edge of the light emitting unit 15 between the adjacent light emitting units 15. Each slit 14 a is formed along the outer edge of the light emitting unit 15 and over a region A (indicated by a two-dot chain line in FIG. 3) between the light emitting unit 15 and the light emitting unit 15. As shown in FIG. 3, a compensation electrode 16 a is connected to each light emitting unit 15, and each compensation electrode 16 a is connected to each other by a connection line 16. The connection line 16 is wired avoiding the slit 14a. The slit 14a can be formed by punching or cutting with a blade, or fusing with a laser or high frequency.

  Each slit 14a is sealed with a sealing member 18 formed of an elastic material. In the present embodiment, the slit 14a is sealed by filling the slit 14a with the sealing member 18. Further, the sealing member 18 is formed to be thicker than the base sheet 14, and the peripheral portion of the slit 14 a is surrounded by the sealing member 18. Thereby, the fixed area of the formation part of the slit 14a and the sealing member 18 is raised, and peeling of the sealing member 18 can be suppressed. The elastic material forming the sealing member 18 is not particularly limited as long as it is a material having a lower elastic modulus than the material constituting the base sheet 14. Examples of such elastic materials include synthetic rubbers such as silicone rubber, urethane rubber, and ethylene propylene rubber, soft resins such as polyolefin resin, ABS resin, polyester resin, and polyurethane resin, or polystyrene, polyolefin, and polyester. And thermoplastic elastomers such as polyurethane and polyurethane.

  The elastic modulus of the elastic material is preferably 1/10 to 1 / 10,000 of the elastic modulus of the material constituting the base sheet 14. If the elastic modulus of the elastic material is greater than 1/10, the sealing member 18 may not be easily deformed. On the other hand, if the elastic modulus of this elastic material exceeds 1/10000, the restoring force of the deformed sealing member 18 may be insufficient. The elastic modulus of the elastic material is preferably 0.01 to 100 MPa, more preferably 0.1 to 20 MPa. If the elastic modulus of the elastic material is less than 0.01 MPa, the deformed sealing member 18 may not be sufficiently restored. On the other hand, if the elastic modulus of the elastic material exceeds 100 MPa, the sealing member 18 may not be easily deformed. This elastic modulus indicates an elastic modulus based on ASTM D882-64T, which is a standard of the American Society for Testing Materials.

  The hardness Hs of the elastic material is preferably 1 to 80, more preferably 5 to 60. When the hardness Hs of the elastic material is less than 1, the restoring force of the deformed sealing member 18 may not be sufficiently obtained. On the other hand, if the hardness Hs of the elastic material exceeds 80, the sealing member 18 may not be easily deformed. This hardness is measured by a type A durometer according to JIS K 6253.

  The light emitting unit 15 can be an EL element such as an inorganic EL element or an organic EL element. The light emitting unit 15 will be described in detail. As shown in an enlarged view in FIG. 2, the light emitting unit 15 is configured by laminating a transparent electrode layer 15a, a light emitting layer 15b, a dielectric layer 15c, and a back electrode layer 15d in this order. . The transparent electrode layer 15a as the uppermost layer is made of a material having translucency and conductivity. As the transparent electrode layer 15a, for example, a thin film formed by vapor deposition or sputtering of an indium-tin compound (ITO), or a thin film formed using a paint in which fine crystal powder such as ITO or tin is dispersed is used. Can do. Furthermore, it was formed using a paint formed by solubilizing an organic conductive polymer such as a polyacetylene conductive polymer, a polythiophene conductive polymer, a polypyrrole conductive polymer, or a polyparaphenylene conductive polymer. Thin films can also be used.

  The light emitter layer 15b located below the transparent electrode layer 15a is generally formed using a paint containing light emitter powder. As the phosphor powder, for example, zinc sulfide doped with copper and manganese added to adjust the emission color or aluminum added as an activator can be used. Furthermore, a phosphor powder whose surface has been coated with an oxide or nitride to improve moisture resistance can also be used.

  The dielectric layer 15c located below the light emitting layer 15b is an electrically insulating and high dielectric constant layer. As the dielectric layer 15c, for example, a fine powder of barium titanate is used as a fluororesin, cyano It can be formed using a paint dispersed in a resin such as a resin or polyester resin.

  The lowermost back electrode layer 15d is a thin film formed by vapor deposition or sputtering of aluminum, silver, ITO or the like, a metal foil such as aluminum or copper, a fine powder of carbon, silver, copper, etc., polyester, urethane, acrylic It can be formed using a paint or the like dispersed in a resin such as a silicone or a silicone.

  The compensation electrode 16a is joined to the transparent electrode layer 15a and the back electrode layer 15d, and when a voltage is applied between the electrodes via the compensation electrode 16a, the light emitter layer 15b emits light. The light emitted from the light emitter layer 15 b is transmitted through the transparent electrode and the base sheet 14 and illuminates the upper side of the base sheet 14.

  On the upper surface of the base sheet 14, a key body 13 having a rectangular shape corresponding to each light emitting portion 15 is fixed. Each key body 13 is formed of a translucent material, and thus transmits light emitted from the light emitting unit 15. The material forming the key body 13 is not particularly limited as long as it has translucency, and is a resin such as a polycarbonate resin, a polyester resin, a fluorine resin, an acrylic resin, an ABS resin, or an AS resin. The material is preferable from the viewpoints of moldability and durability. The key body 13 is illuminated from below by the light emitting unit 15 via the transparent electrode layer 15a and the base sheet 14. In this embodiment, since a display (not shown) such as characters and symbols is printed on the upper surface of the base sheet 14, the display is visually recognized from the upper surface of the key body 13. Such a display may be provided on the lower surface of the base sheet 14 or the key body 13. Each key body 13 can be joined to the base material sheet 14 by adhesion using an adhesive, welding of the key body 13, or the like.

  As shown in FIGS. 1 and 2, in the keypad 11 incorporated in the housing 52, the upper end portion of the key body 13 is exposed from an opening 52 a penetrating the upper wall of the housing 52. A predetermined gap is provided between the inner peripheral wall of the opening 52 a and the outer peripheral wall of the key body 13, and a downward pressing operation of the key body 13 is allowed. Further, the sealing member 18 which is thicker than the base sheet 14 and has a lower elastic modulus is incorporated in the housing 52 in close contact with the inner surface of the upper wall of the housing 52. Then, as indicated by an arrow in FIG. 4, when the base sheet 14 is displaced downward as the key body 13 is pressed, the sealing member 18 is deformed accordingly. Due to the deformation of the sealing member 18, the following movement operation of the key body 13 adjacent to the pressed key body 13 is suppressed.

  In addition, it is assumed that unnecessary objects such as moisture and dust enter the housing 52 through the gap between the opening 52a and the key body 13. In such a case, if the slit 14a is penetrated, there is a possibility that an unnecessary object may enter the accommodating portion 54 through the slit 14a. In the present embodiment, since the slit 14 a is sealed by the sealing member 18, the intrusion of unnecessary objects into the housing portion 54 is suppressed. Furthermore, in the keypad 11 of the present embodiment, the sealing member 18 is in close contact with the inner surface of the upper wall of the housing 52, and the slit 14a itself is sealed by the sealing member 18, so that the slit 14a is interposed. Invasion of unnecessary objects is suppressed.

The effects exhibited by this embodiment will be described below.
(1) In the keypad 11 of this embodiment, since the slit 14a formed in the base material sheet 14 is sealed by the sealing member 18, it is suppressed that an unnecessary object penetrate | invades into the accommodating part 54 through the slit 14a. can do. As a result, contact between the circuit board 53 provided in the accommodating portion 54 and an unnecessary object is avoided, so that the circuit board 53 is appropriately protected in the mobile phone 51 in which the keypad 11 is incorporated. For this reason, the reliability about the operation | movement of the circuit board 53 can be improved. Further, the sealing member 18 is formed of an elastic material having a lower elastic modulus than the material constituting the base sheet 14 so as to be deformed with the pressing operation of the key body 13. For this reason, the sealing member 18 deform | transforms with the press operation of the specific key main body 13, and the unnecessary operation | movement which the key main body 13 adjacent to the pressed key main body 13 followed can be suppressed. As a result, the load necessary for pressing the key body 13 is reduced, and thus the keypad 11 having a good operational feeling can be provided.

  Furthermore, according to this configuration, even when the base sheet 14 having a higher elastic modulus is employed to improve the protection performance of the light emitting unit 15 and the compensation electrode 16a, the deformable sealing member 18 , The operational feeling can be maintained well. That is, by improving the protection performance of the light emitting unit 15 and the compensation electrode 16a, the light emitting unit 15 and the like can be appropriately protected while maintaining the operability as the keypad 11.

  (2) The elastic modulus of the elastic material constituting the sealing member 18 is preferably 1/10 to 10000 of the elastic modulus of the material constituting the base sheet 14. In this case, the sealing member 18 is suitably deformed with respect to the displacement of the base sheet 14, and a better operational feeling is obtained.

(3) By filling the sealing member 18 into the slit 14a, the slit 14a can be reliably sealed with a small amount of elastic material.
(4) The sealing member 18 is formed thicker than the thickness of the base sheet 14, and the peripheral portion of the slit 14a is surrounded by the sealing member 18, thereby forming the slit 14a and the sealing member. The fixing area with 18 is increased. For this reason, peeling of the sealing member 18 can be suppressed. Therefore, even if it is used for a long time, the intrusion of unnecessary objects can be continuously suppressed.

  (5) According to the keypad 11 in which the sealing member 18 is formed to be thicker than the base material sheet 14 and the sealing member 18 is incorporated in close contact with the inner surface of the housing 52, the base material sheet 14 and the inner surface of the housing 52 and the sealing of the slit 14a itself prevent the intrusion of unwanted objects through the slit 14a. For this reason, it can suppress more reliably that an unnecessary object penetrate | invades into the accommodating part 54. FIG.

In addition, the said embodiment can also be changed and comprised as follows.
-The shape of the sealing member 18 will not be specifically limited if it is a shape which exhibits the function which seals the slit 14a, For example, it can change as shown to Fig.5 (a)-(c). The sealing member 18 shown in FIG. 5A has a quadrangular cross section and is formed with a substantially constant thickness. The sealing member 18 shown in FIG. 5B is formed to have substantially the same thickness as the base material sheet 14 and is filled in the slit 14a.

  Furthermore, the sealing member 18 may not be filled in the slit 14a. For example, the sealing member 18 shown in FIG. 5C is formed in a sheet shape from an elastic material and is laminated on the sheet surface of the base material sheet 14.

  -The formation pattern of the slit 14a is not specifically limited. For example, the slit 14a of the keypad 11 (omitted from the compensation electrode 16a) shown in FIG. 6A is formed by separating the slit 14a extending in the vertical direction and the slit 14a extending in the horizontal direction. Yes. Furthermore, the slit 14a may be changed to a linear shape, a curved shape, or the like.

  -You may provide the sealing member 18 in parts other than the formation part of the slit 14a. For example, in the keypad 11 shown in FIG. 6B (the compensation electrode 16 a is omitted), the sealing member 18 formed thicker than the base sheet 14 surrounds all the light emitting portions 15. The keypad 11 is incorporated in the casing 52 with the sealing member 18 in close contact with the inner surface of the casing 52. And since the unnecessary thing which reaches | attains the sealing member 18 which seals the slit 14a can be reduced, the reliability of the sealing effect by the sealing member 18 can be improved.

  The key body 13 is fixed to the upper surface of the base sheet 14, but the key body 13 may be fixed to the lower surface of the base sheet 14. In the EL sheet 12 constituting the keypad 11 shown in FIGS. 7 and 8, the base material sheet 14 and the light emitting portion 15 bulge upward from the key body 13. The key body 13 is bonded to the light emitting portion 15 provided on the lower surface of the base sheet 14 via a resist 17 that covers the light emitting portion 15. In the keypad 11, the key body 13 is pressed through the bulged portion of the EL sheet 12. In addition, the key main body 13 in this modification does not need to have translucency.

  A protrusion 19 is provided on the lower surface of the key body 13 shown in FIG. The contact point switch SW may be pressed by the protrusion 19. Further, the protruding portion 19 may be provided on the resist 17 of the embodiment.

  The number of light emitting units 15 and key bodies 13 and the number of columns are not particularly limited. Furthermore, the arrangement form of the light emitting unit 15 and the key body 13 is not particularly limited, and may be arranged along an arc shape, for example.

  -The shape of the light emission part 15 and the key main body 13 is not specifically limited, For example, it can also change into circular shape and elliptical shape. The light emitting unit 15 and the key body 13 may have the same shape, or the light emitting unit 15 and the key body 13 may have different shapes.

  The case 52 to which the keypad 11 is applied is not limited to the case of the mobile phone 51. For example, you may apply to the housing | casing which comprises input devices, such as a remote controller, a personal digital assistant (PDA), etc.

Next, the embodiment will be described more specifically with reference to examples.
As the base sheet 14, a light emitting portion 15 and a compensation electrode 16a were disposed on a polyethylene terephthalate resin film (elastic modulus 5000 MPa). The light emitting section 15 and the compensation electrode 16a are made of an ITO powder-containing paste (7160 manufactured by DuPont) that forms a transparent electrode, a blue-green phosphor powder-containing paste (7151 manufactured by DuPont) that forms a light emitter layer 15b, and a dielectric layer 15c. Formed by laminating a dielectric powder-containing paste (7148 made by DuPont) forming silver, a silver powder-containing paste (7145 made by DuPont) forming the back electrode layer 15d, and a silver paste forming the compensation electrode 16a by printing. did. Further, the light emitting portion 15 and the compensation electrode 16 a were covered with a resist 17. Next, as shown in FIG. 3, the slit 14 a is formed in the base sheet 14, and the slit 14 a is moisture-cured liquid silicone rubber (KE44 manufactured by Shin-Etsu Chemical Co., Ltd., elastic modulus: 2.5 MPa, hardness Hs: 24 ). By curing the liquid silicone rubber, the sealing member 18 shown in FIG. 2 was formed, and the keypad 11 was manufactured. When the upper surface of the keypad 11 was submerged, it was not confirmed that the water leaked from the lower surface side of the keypad 11. From this, it was confirmed that the slit 14a was reliably sealed by the sealing member 18. Further, the keypad 11 was incorporated into the casing 52 together with the circuit board 53, and a key pressing operation was performed. As a result, it was confirmed that unnecessary follow-up operation of adjacent keys is suppressed as compared with a conventional keypad having no slit 14a, and that it can be operated with a light pressing load.

The perspective view which shows a part of mobile phone. Sectional drawing in the 2-2 line of FIG. The top view which shows a keypad. Sectional drawing which shows the state by which the key was pressed. (A), (b) and (c) is sectional drawing which shows the modification of a sealing member. (A) is a top view which shows the modification in the formation pattern of a slit, (b) is a top view which shows the modification in the formation pattern of a sealing member. The top view which shows the modification of a keypad. Sectional drawing which shows the modification of a keypad.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Keypad, 12 ... EL sheet | seat, 13 ... Key main body, 14 ... Base material sheet, 14a ... Slit, 15 ... Light emission part, 18 ... Sealing member, 52 ... Housing | casing, 54 ... Storage part.

Claims (5)

An electroluminescence sheet in which a plurality of light emitting portions are disposed apart from each other on a sheet surface of a base sheet having translucency;
A plurality of key bodies bonded to the electroluminescence sheet corresponding to the plurality of light emitting sections, and used by being incorporated in the casing so as to block the outside of the casing and the circuit board housing section in the casing. Keypad,
Between the adjacent light emitting portions, the base sheet is formed with a slit that penetrates the base sheet along its thickness direction, and the slit is sealed with a sealing member,
The sealing member is formed of an elastic material having an elastic modulus lower than that of the material constituting the base sheet, in order to be deformed by the displacement of the base sheet accompanying the pressing operation of the key body ,
The keypad , wherein the sealing member is brought into close contact with an inner surface of the casing and is incorporated in the casing . 2. The keypad according to claim 1, wherein an elastic modulus of an elastic material constituting the sealing member is 1/10 to 1 / 10,000 of an elastic modulus of a material constituting the base sheet. The keypad according to claim 1, wherein the sealing member is filled in the slit. The keypad according to claim 3, wherein the sealing member is formed to be thicker than the base sheet, and a peripheral portion of the slit is surrounded by the sealing member. 5. The sealing member according to claim 1, wherein the sealing member is formed to be thicker than the base sheet, and the sealing member is incorporated into the casing while being in close contact with the inner surface of the casing. Keypad as described in section.

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