1. Technical Field
The disclosure generally relates to input devices, and more particularly relates, to a key structure used in an electronic device.
2. Description of the Related Art
Different control keys are often used in mobile phones, personal digital assistants (PDAs), or other electronic devices, such as cameras. When depressed, the movable contacts of the keys elastically and electrically contact and connect the circuit boards in the electronic devices, to activate corresponding functional circuits. When the keys are released, the movable contacts disconnect from the circuit board to switch the functional circuits off.
However, conventional key structures typically provide only limited operations, merely on and off states.
Therefore, there is room for improvement within the art.
Many aspects of an exemplary key structure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the exemplary key structure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.
The substrate 15 may be a printed circuit board (PCB) used for layout of electronic components and different function circuits. The fixed contact member 13 is positioned on the substrate 15 and is electrically connected to corresponding key circuits and/or switch circuits.
Referring to
The movable contact spring 116 is substantially a domed extension from operating part 15 and formed in a peripheral surface which can be elastically reversibly deformed. The movable contact spring 116 includes a second movable contact 117 provided on the domed inner surface 113. The second movable contact 117 is positioned at the junction of the operating portion 115 and the movable contact spring 116, having a predetermined diameter about a center of the apex of the operating portion 115, spaced radially away from (radially outside) the operating portion 115. The second movable contact 117 protrudes from the domed inner surface 113, and may have a circular shape on the inner surface 113, and is formed by half-cut working by use of a pressing machine. Moreover, the circular second movable contact 117 is not just limited to the circular shape, can also be punched and/or cut into pluralities of different parts, such as elliptical parts, oval parts, rectangular parts, square parts, and other polygonal parts arranged on the same circle on the inner surface 113.
The movable contact spring 116 further includes a circular fixed portion 119 at the periphery thereof. The fixed contact member 13 includes a first fixed contact 131, a second fixed contact 133 around the first fixed contact 131, and a conductive portion 135 around the second fixed contact 133. The first fixed contact 131, the second fixed contact 133 and the conductive portion 135 are made of copper foil or other conductive metal on the upper surface of the substrate 15, normally by print wiring technique.
The first fixed contact 131 faces the first movable contact 1151, the shape and the size of the first fixed contact 131 match the shape and the size of the first movable contact 1151. The second fixed contact 133 may form a substantially circular shape on the upper surface of the substrate 15, and can be cut into different parts, such as elliptical parts, oval parts, rectangular parts, square parts, and other polygonal parts. The size and the shape of the second fixed contact 133 match the size and the shape of the second movable contact 117, and the second fixed contact 133 is substantially aligned with the second movable contact 117, respectively.
The conductive portion 135 forms a shape on the upper surface of the substrate 15 conforming to the fixed portion 119 and can be obtained by punching and/or cutting a piece of metal belt. The conductive portion 135 is substantially aligned with the circular fixed portion 119. The first fixed contact 131, the second fixed contact 133 and the conductive portion 135 are substantially concentric circles and are electrically connected different corresponding function circuits. Thus, the first movable contact 1151 and the second movable contact 117 contact or break off the contact with the opposed fixed first contact 131 and the second fixed contact 133 to electrically connect or disconnect different key circuits, switch circuits or other function circuits.
Further referring to
Further referring to
Moreover, when the operating load F is released from the operation portion 115, the elastic deformations of the operation portion 115 and the movable contact spring 166 are recovered. Thus, the first movable contact 1151 is electrically disconnected from the first fixed contact 131, the second movable contact 117 is electrically and elastically disconnected from the first second contacts 133, and the key structure 10 resumes from the operating state to the off state. The first fixed contact 131, the second fixed contact 133 and the conductive portion 135 are electrically disconnected from each other.
In summary, in the key structure 10 of the exemplary embodiment, the first movable contact 1151 and the second movable contact 117 respectively face the first fixed contact 131 and the second fixed contact 133. When different operating loads F act on the operation portion 115, the first movable contact 1151 and the second movable contact 117 respectively electrically connect and contact the first fixed contact 131 and the second fixed contact 133. Thus, the key structure 10 is switched from the off state to corresponding operating states, and generates corresponding command signals, and electrically connects corresponding function circuits to operate the electronic device.
It is to be understood, however, that even though numerous characteristics and advantages of the exemplary disclosure have been set forth in the foregoing description, together with details of the structure and function of the exemplary disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of exemplary disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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201010235448.3 | Jul 2010 | CN | national |