1. Field of the invention
The present invention relates to keypad assemblies, and particularly, to a keypad assembly used in a portable electronic device.
2. Description of related art
Portable electronic devices (e.g., mobile phones and digital cameras) are becoming smaller and thinner.
Thus, a mini keypad assembly is needed to meet small and thin demands. However, the symbols/numbers printed on the keypad assembly may become too small to read.
Therefore, there is room for improvement within the art.
Many aspects of a 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 a plurality of views.
The keypad assembly 10 includes a keypad cover 11, a sensing module 12 and a printed circuit board (PCB) 13. The sensing module 12 and the PCB 13 are electrically connected to the CPU 21. The keypad cover 11, the sensing module 12 and the PCB 13 are aligned with and adhered to each other.
The keypad cover 11 may be made of an elastic material (e.g., rubber). The keypad cover 11 includes a top surface 111 and an opposite bottom surface 112. The top surface 111 defines a plurality of pressing portions 113. Keypad symbols/numerals (e.g., # or 1) are printed to the pressing portions 113. The bottom surface 112 forms a plurality of contact portions 14 corresponding to the pressing portions 13.
The sensing module 12 defines a plurality of touch-sensing portions 121 that can sense slight touches of a user's fingers on the pressing portions 113. When one of the pressing portions 113 is slightly touched but not completely pressed down, the corresponding sensing portion 121 is triggered to send an electronic signal to the CPU 21. When the touch is removed from the pressing portion 113, the sensing module 12 sends another electronic signal to the CPU 21 to cancel the previous electronic signal.
The PCB 13 forms a plurality of press-sensing portions 131 corresponding to the contact portions 114. Each press-sensing portion 131 is generally curved. When one of the pressing portions 113 is pressed down, the corresponding contact 114 abuts against the corresponding press-sensing portion 131. Then the press-sensing portion 131 is triggered to send a corresponding electronic signal to the CPU 21.
The CPU 21 receives the electronic signals sent from the sensing module 12 or the PCB 13, and transforms the electronic signals into outputting commands. The outputting commands are then transmitted to the signal outputting module 22. The signal outputting module 22 receives the outputting commands and export corresponding signals to a screen or an earphone.
In use, when a user's fingers move slightly between different pressing portions 113, the sensing modules 12 can sense the slight touches of user's fingers, and export or cancel the corresponding signals on the screen or the earphone in real-time. Thus, before a pressing portion 113 is pressed completely down, the user can identify which pressing portion 113 is being touched from the screen or the earphone by the sensing module 12. If the touched pressing portion 113 is the desired one, the user can then directly press it completely down. If the touched pressing portion 113 is not the desired one, the user can simply move his fingers to touch other pressing portions 113 until he finds the desired one and then press it completely down.
It is to be understood, however, that even through numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, 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 invention to the full extent indicated by the broad general meaning of the terms, in which the appended claims are expressed.
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