COORDINATE INPUT DEVICE WITH BACK LIGHT

PURPOSE:To remove the unevenness of brightness in a back light part without converting a lighting polarity by arranging respective cathodes at the time of lighting up a fluorescent lamp with DC so as to be opposed to the anode of the other fluorescent lamp or arranged adjacent to the anode. CONSTITUTION:The fluorescent lamp 5 is arranged so that the cathode side of the other fluorescent lamp 5 is arranged on the other side end face position of a light guide 1 opposed to the another side of the fluorescent lamp 5. Since respective brightness uneven states generated by respective lamps 5 are mutually inverted, the unevenness of a light emitting face can be removed by reversely superposing these brightness uneven states. Even when an extinction phenomenon is generated in the cathode due to long DC lighting, the light emitting face of the light guide 1 is prevented from generating the unevenness of brightness.