JP2010262911A - Key unit and electronic device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a key unit which has a longer service life period and dimensional stability and can prevent generation of static electricity, and to provide an electronic device having the key unit. <P>SOLUTION: The key unit has a key top, a body, a side edge section extending from a peripheral edge of the body to the outside and being thinner than thickness of the body, a connection section projecting from a bottom face of the body and electrically connected to a circuit board in the electronic device, and a key mat arranged on the bottom face of the key top. Mesh-shaped metal fabrics are arranged on an upper surface of the side edge section. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a key unit and an electronic apparatus equipped with the key unit.

  In order to meet the demands of users of electronic devices, manufacturers are making efforts to reduce the thickness of electronic devices and extend their useful lives. In order to reduce the thickness of the electronic device, a thin-walled key unit is generally used.

  FIG. 1 is a cross-sectional view of a conventional key unit 1. The key unit 1 includes a key top 11, a key mat 13, and a light guide unit 15. The key top 11 is made of a polycarbonate (Polycarbonate, PC) material, on which an identification pattern such as numbers and letters is formed. The key mat 13 is bonded to the bottom surface of the key top 11 with an adhesive, and includes a main body 131, a side edge portion 133, a mounting portion 135, and a connection portion 137.

  The side edge 133 extends symmetrically from the bottom of the main body 131 to both outer sides, and its thickness is thinner than that of the main body 131. Since the side edge portion 133 has elasticity, the key mat 13 can be automatically restored after the key mat 13 is deformed. The mounting portion 135 protrudes from the bottom surface of the side edge portion 133 and engages with a cover of an electronic device (not shown). The connection part 137 is formed at the center of the bottom surface of the main body 131 and is electrically connected to a circuit board inside the electronic device when the key top 11 is pressed. The light guide portion 15 is provided on the bottom surface of the side edge portion 133 and outside the mounting portion 135, and guides light from a backlight (not shown) to the key top 11, so that the key top 11 Light up the above identification design.

  When the key unit 1 is used, the key top 11 is pressed with a finger. The key mat 13 is pressed by the key top 11 and moves downward while resisting the elastic force of the side edge portion 133. Accordingly, the connection portion 137 formed at the center of the bottom surface of the key mat 13 moves downward and connects to a circuit board (not shown) inside the electronic device, thereby turning on the circuit board switch ( ON) / OFF (OFF).

  Since the side edge 133 is thinner than the main body 131, when the key mat 13 moves downward, the side edge 133 is deformed first and deformed most. That is, the thickness of the side edge portion 133 is smaller than that of the main body 131 and the amount of deformation thereof is larger than that of the main body 131. Accordingly, when the key unit 1 is used for a long time, the side edge portion 133 having the thin thickness is broken first, which affects the service life of the key unit 1.

  In order to increase the strength and service life of the side edge 133, a thermoplastic polyurethane (TPU) film 139 can be installed on the upper surface of the side edge 133 and the main body 131 by an insert molding method. . That is, the upper surface of the key mat 13 can be covered with the TPU film 139. Since the TPU film 139 is excellent in tensile strength and adheres tightly to the side edge portion 133, the strength and service life of the side edge portion 133 can be increased.

  However, since the TPU film 139 has a property of being easily contracted when heated to about 85 ° C., when the key unit 1 is manufactured by the insert molding method, the dimension of the TPU film 139 is set. It's hard to control. That is, since the dimension of the TPU film 139 is not stable, the dimensional accuracy and quality of the key unit 1 are deteriorated. In addition, since the TPU film 139 is non-conductive, a large amount of static electricity can be collected when the key unit 1 is used. Therefore, the key unit 1 can be damaged by a large amount of static electricity.

  In view of the above problems, an object of the present invention is to provide a key unit that has a long service life, is stable in dimensions, and can prevent the generation of static electricity, and an electronic device equipped with the key unit.

  In order to solve the above problem, a key unit according to the present invention includes a key top, a main body, a side edge that extends outward from the periphery of the main body and is thinner than the thickness of the main body, and a bottom surface of the main body. And a connecting portion electrically connecting to a circuit board inside the electronic device, and a key mat installed on the bottom surface of the key top, and having a mesh shape on the upper surface of the side edge portion A metal fabric is provided.

  In order to solve the above problem, an electronic device according to the present invention includes a key top, a main body, a side edge formed to extend outward from a peripheral edge of the main body, and thinner than the thickness of the main body, An electronic device including a key unit that includes a connection portion that protrudes from the bottom surface and is electrically connected to a circuit board inside the electronic device, and a key mat installed on the bottom surface of the key top. A mesh-shaped metal fabric is provided on the upper surface of the side edge.

  In the key unit of the present invention, a metal fabric is formed on the upper surface of the side edge of the key mat. Since the metal fabric excellent in tensile strength is tightly joined to the side edge portion of the key mat, the tensile strength of the side edge portion is increased, and the service life thereof is increased. That is, even if the key unit is used for a long time, the side edge portion is not easily broken, so that the service life of the key unit can be extended. In addition, since the said metal fabric does not shrink excessively even if it heats at high temperature, it is easy to control the dimension of the said metal fabric. Accordingly, the dimensional accuracy and quality of the key unit can be improved.

  Further, since the metal fabric has conductivity, the key mat is not damaged by a large amount of static electricity generated by friction or the like when the key mat is used. Therefore, the service life can be further increased.

It is sectional drawing of the key unit which concerns on a prior art. It is sectional drawing of the key unit which concerns on the 1st Example of this invention. It is sectional drawing of the key unit which concerns on the 2nd Example of this invention. It is sectional drawing of the key unit which concerns on the 3rd Example of this invention. 1 is a perspective view of an electronic device according to the present invention.

  Hereinafter, a key unit according to an embodiment of the present invention and an electronic device equipped with the same will be described in detail with reference to the drawings.

  FIG. 2 is a sectional view of the key unit 3 according to the first embodiment of the present invention. The key unit 3 includes a key top 31, a key mat 33, a light guide 35, and a mesh-shaped metal fabric 37 formed on the upper surface of the key mat 33. In the present embodiment, the electronic device refers to a mobile phone, a personal digital assistant (abbreviated as Personal Digital Assistant, PDA), and the like.

  The key top 31 is made of a resin such as polycarbonate or polymethylmethacrylate (PMMA). The key top 31 is formed with an identification design such as letters and numbers.

  The key mat 33 is manufactured from a silicone material and is fixed to the bottom surface of the key top 31 by an adhesive or an integral molding method. The key mat 33 includes a main body 331, at least two side edge portions 333, at least two attachment portions 335, and a connection portion 337.

  The side edge portion 333 extends from the bottom of the main body 331 to both outer sides, and the thickness thereof is thinner than that of the main body 331 and is excellent in elastic force. Since the side edge portion 333 has elasticity, the key mat 33 can be automatically restored after the key mat 33 is deformed. The mounting portion 335 protrudes from the bottom surface of the side edge portion 333 and engages with a cover (not shown) of the electronic device. The connection portion 337 is formed at the center of the bottom surface of the main body 331. When the key top 31 is pressed, the connection portion 337 is electrically connected to a circuit board (not shown) inside the electronic device.

  The light guide part 35 is provided at both ends of the key mat 33, that is, at the bottom surface of the side edge part 333 and outside the mounting part 335. The light guide 35 is made of a resin material such as PC or PMMA, like the key top 31, and guides light from a backlight (not shown) to the key top 31 for identification on the key top 31. Light the design.

  The metal fabric 37 is a mesh-shaped metal fabric made of conductive metal silk (metal fiber). In the present embodiment, the metal fabric 37 is integrally formed on the upper surface of the side edge portion 333 and the inside of the main body 331 by an insert molding method. When the key unit 3 is molded by the insert molding method, the silicone material forming the key mat 33 is injected into the mesh hole of the metal fabric 37, so that the key mat 33 and the metal fabric 37 are tightly joined. . That is, the metal fabric 37 and the side edge portion 333 of the key mat 33 are integrally formed.

  Since the metal fabric 37 having excellent tensile strength is tightly joined to the side edge portion 333 of the key mat 33, the tensile strength of the side edge portion 333 is increased, and the service life thereof is increased. Therefore, even if the key unit 3 is used for a long time, the side edge portion 333 is not easily broken, and the service life of the key unit 3 can be extended. Since the metal fabric 37 does not shrink excessively even when heated at a high temperature, the dimensions of the metal fabric 37 can be easily controlled when the key unit 3 is manufactured. Accordingly, the dimensional accuracy and quality of the key unit 3 can be improved. Since the metal fabric 37 is a conductive fabric, static electricity generated by friction or the like can be prevented from being collected by the key unit 3. Therefore, the key mat 3 can be prevented from being damaged by static electricity, and the service life of the key mat 3 can be extended.

  The metal fabric 37 may be installed on the upper surface of the key mat 33. That is, the metal fabric 37 may be installed on the side edge 333 and the upper surface of the main body 331.

  FIG. 3 is a sectional view of the key unit 5 according to the second embodiment of the present invention. The key unit 5 includes a key top 51, a key mat 53, a light guide portion 55, and a mesh-shaped metal fabric 57. The key mat 53 is fixed to the bottom surface of the key top 51, and includes a main body 531, at least two side edge portions 533, at least two attachment portions 535, and a connection portion 537. The metal fabric 57 is installed inside the main body 531 and on the upper surface of the side edge portion 533.

  As shown in FIG. 3, the light guide part 55 is formed outside the mounting part 535, and the height thereof is equal to the height of the mounting part 535. Since the light guide 55 is larger than the light guide 35 shown in FIG. 2, the light from the backlight can be more effectively guided to the upper side of the key unit 5. Accordingly, the identification design such as numbers and letters on the key top 51 becomes brighter, and the user can easily identify the identification design.

  FIG. 4 is a sectional view of the key unit 7 according to the third embodiment of the present invention. The key unit 7 includes a key top 71, a key mat 73, a light guide portion 75, and a mesh-shaped metal fabric 77. The key mat 73 is fixed to the bottom surface of the key top 71 and includes a main body 731, at least two side edge portions 733, at least two attachment portions 735, and a connection portion 737. The metal fabric 77 is installed inside the main body 731 and on the upper surface of the side edge portion 733.

  As shown in FIG. 4, a chamfer is formed at the connecting portion between the side edge portion 733 and the mounting portion 735. The chamfering prevents stress concentration from occurring in the connecting portion, and further extends the service life of the side edge portion 733. Further, in order to further increase the service life of the key unit 7, chamfering (not shown) can be formed at the connecting portion between the main body 731 and the side edge portion 733.

  FIG. 5 is a perspective view of the electronic device according to the present invention. The electronic device refers to a mobile phone, a portable information terminal, or the like. In this embodiment, the electronic device is a mobile phone 9. A plurality of key units 91 for inputting numbers and the like, a display device 93 for displaying images, and the like are installed on the front surface of the mobile phone 9. The key unit 91 has the same structure as the key unit shown in FIG. 2, FIG. 3, or FIG.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications or corrections are possible within the scope of the present invention. However, it goes without saying that it is included in the scope of the claims of the present invention.

1, 3, 5, 7, 91 Key unit 11, 31, 51, 71 Key top 13, 33, 53, 73 Key mat 131, 331, 531, 731 Main body 133, 333, 533, 733 Side edge 135, 335 535, 735 Mounting part 137, 337, 537, 737 Connection part 139 Thermoplastic polyurethane 15, 35, 55, 75 Light guiding part 37, 57, 77 Metal fabric 9 Mobile phone 93 Display device

Claims (4)

Key tops,
A key mat installed on the bottom surface of the key top;
The key mat is connected to the main body, a side edge extending from a peripheral edge of the main body and being thinner than the thickness of the main body, and protruding from the bottom surface of the main body, and electrically connected to a circuit board inside the electronic device. And
A key unit comprising:
A key unit characterized in that a mesh-like metal fabric is provided on the upper surface of the side edge portion.   The key unit according to claim 1, wherein the metal fabric is integrally formed with the key mat.   The metal fabric is a mesh-shaped metal fabric made of conductive metal silk, and the material constituting the key mat is injected into a mesh hole of the metal fabric, whereby the key mat and the metal fabric are separated. The key unit according to claim 2, wherein the key unit is tightly joined. Key tops,
A key mat installed on the bottom surface of the key top;
The key mat is connected to the main body, a side edge extending from a peripheral edge of the main body and being thinner than the thickness of the main body, and protruding from the bottom surface of the main body, and electrically connected to a circuit board inside the electronic device. And
An electronic device equipped with a key unit comprising
An electronic device comprising an upper surface of the side edge portion and a mesh-shaped metal fabric.

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