Disclosed herein are various embodiments of a capacitive touchscreen system which includes switchable charge acquisition circuits and corresponding charge integrator circuits for sensing mutual capacitances associated with a touchscreen. In certain example embodiments, this is accomplished by providing an organic-inorganic hybrid material on LEDs, enhancing the light scattering ability of the LEDs, andor improving performance through advanced cooling techniques. When the standby mode is changed to the digital mode, the electronic mail is transmitted through a digital channel. The electromagnetic solenoid permits relative movement between the stopper member and the cam member when the electromagnetic solenoid is unenergized and prevents relative movement between the stopper member and the cam member when the electromagnetic solenoid is energized. The adjusting member comprises a flange received in the limiting hole.