1. Technical Field
The present disclosure relates to keypad assemblies and, particularly, to a keypad assembly used in a portable electronic device.
2. Description of Related Art
Keypad assemblies used in portable electronic devices such as mobile phones and personal digital assistants (PDAs) are becoming smaller and thinner.
A typical keypad assembly includes a printed circuit board (PCB), a pressing cover, a pressing body having elastic beams for connecting with pressing buttons, and a mounting frame. However, the mounting frame increases the thickness of the keypad assembly. Furthermore, the elastic beam typically has a long size to ensure its deformability, thus further increasing a related size of the keypad assembly.
Therefore, there is room for improvement within the art.
Many aspects of the keypad assembly can be better understood with reference to the following drawings. These drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present keypad assembly. Moreover, in the drawings like reference numerals designate corresponding sections throughout the several views.
The present keypad assembly is suitable for use in a portable electronic device, e.g., mobile phone and personal digital assistant (PDA).
Referring to
The pressing cover 11 can have any shape and is used to be pressed by a user. The pressing cover 11 includes a plurality of pressing caps, e.g., a plurality of first pressing caps 111 and a second pressing cap 112. The first pressing caps 111 surround the second pressing cap 112. The second pressing cap 112 is a multi-directional pressing cap. The first pressing caps 111 and the second pressing cap 112 are printed with symbols, e.g., letters, figures, and etc. The pressing cover 11 is formed by ploycarbonate (PC) injecting.
The pressing body 12 is made of elastic material. In this embodiment, the pressing body 12 is generally rectangular shaped. The pressing body 12 includes a main board 121, and a plurality of keys 122. Each key 122 includes a mounting portion 123 and a pressing button 125 respectively protruding from opposite surfaces of the main board 121. The mounting portions 123 are arranged corresponding to the arrangement of the pressing caps 111, 112 to be respectively mounted to the pressing caps 111, 112. The pressing buttons 125 are arranged corresponding to the mounting portions 123, and used to contact the printed circuit board 13. Each pressing button 125 has a light-guiding surface 1251 (as shown in
The printed circuit board 13 includes a plurality of elastic contacting sheets 131 and lamps 132. Each lamp 132 is arranged adjacent to a corresponding contacting sheet 131. In the exemplary embodiment, the lamps 132 are light emitting diodes (LEDs). Each pressing button 125 is aligned with and spaced from the corresponding contacting sheet 131.
The support member 14 is generally a frame. The support member 14 includes a plurality of receiving cavities 141, and a plurality of support beams 142. The receiving cavities 141 are arranged corresponding to the keys 122 of the pressing body 12. The support beams 142 connect each other, surrounding the receiving cavities 141. The support member 14 is sandwiched between the pressing body 12 and the PCB 13. Each receiving cavity 141 receives a corresponding pressing button 125, a corresponding contacting sheet 131, and a corresponding lamp 132 therein. One end of each support beam 142 abuts against the PCB 13, the other end abuts against the deformable area 126, thus separating adjacent pressing buttons 125, contacting sheets 131, and lamps 132. The support member 14 is made of opaque and elastic material, e.g., ducked cotton.
Referring to
In use, when a pressing cap 111 or 112 is pressed, the support beams 142 and the deformable area 126 connected to the corresponding pressing button 125 will be elastically stretched. Thus, the pressing button 125 moves towards the corresponding contacting sheet 131 of the PCB 13, until the pressing button 125 presses the contacting sheet 131 to trigger an input signal. Then the pressing cover 11 is released, the support beams 142 and the deformable area 126 rebound and drive the pressing cover 11 to resume to its previous shape. While the pressing cover 11 is pressed, the support beams 142 also slightly deforms, thus reinforcing elastic force of the deformable area 126. Therefore, a smaller deformable area 126 can be used for the keypad assembly 10, thus minimizing the related size of the keypad assembly 10. Furthermore, the support member 14 is located between the pressing body 12 and the printed circuit board 13, further reducing the thickness of the keypad assembly 10.
It is to be understood, however, that even through numerous characteristics and advantages of the present disclosure have been set forth in the foregoing description, together with details of the structure and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of sections within the principles of the 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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200910301716.4 | Apr 2009 | CN | national |