Patent ID: 7928963

Claim:
An input device applied to a mobile electronic apparatus comprising: a button layer, comprising: a letter button module, having a plurality of letter buttons to represent different letters respectively, the letter buttons being arranged into a plurality of rows, wherein every two adjacent said rows has a respective interval; and a number button module, having a plurality of number buttons to represent different numbers respectively, the number buttons being arranged into a plurality of rows, wherein each said row of said number button module disposed in the respective interval between the adjacent said rows of said letter button module, wherein the number buttons are different in shape from the letter buttons; a support layer formed to provide strength to support the button layer, said support layer comprising a plurality of through holes arranged under the button layer and opposite to the letter buttons and the number buttons; and a buffer layer used to enhance elasticity of the button layer, said buffer layer being arranged under the support layer and having a plurality of prominent pillars located corresponding to the through holes, wherein said pillars pass through the through holes to touch the button layer, and each of the pillars has a downward extended pressing column to stand on a metal dome on a printed circuit board located under the buffer layer.