Disclosed is a printed circuit board configured for a dome-utilizing keypad configuration including at least one padstack having a plurality of dome switch targets and a plurality of target rings capable of accommodating different key dome locations of a dome keypad. In the formula ring may be phenyl, pyridyl etc. The link member is rotatably connected to a second end of a rear suspension via a first shaft, and is rotatably connected to a rear arm via a second shaft. Performance required for the optical system is such that the size of the diameter of 90% encircled energy of the point spread function by amplitude is allowed to be up to about 8 times larger than the pixel pitch corresponding to the resolvable pixel unit. A flexural border is formed on one side of the side border of the guiding groove. An arc generated between both the contact points is moved in a lateral direction by the magnetic force of the permanent magnet and stretched.