A gradation attributes correcting device to correct gradation attributes of an input image signal includes a brightness gradation correcting unit to correct gradation attributes with respect to brightness of an image indicated by the input image signal. Alternating phase voltage potentials are applied to the phase conductors of the electric machine for commutation, said phase voltage potentials being generated by a pulse-width modulation so that the height of the applied phase voltage potential is determined by a duty cycle of the pulse width modulation. The photo-sensing device is built in the LCD panel and includes a plurality of photo-sensors having different illumination sensing capabilities.