CONSTANT CURRENT GENERATING CIRCUIT AND DISPLAY DEVICE

PROBLEM TO BE SOLVED: To provide a constant current generating circuit which enables an effective area of an output current waveform to be brought close to that of an ideal output waveform, and further enables control of a rise time and fall time of the output current waveform, and to provide a display device which enables the relation between the number of gradations and brightness to be brought close to an ideal characteristic by applying the constant current generating circuit to the gradation control. SOLUTION: A current pulse having an arbitrary waveform is generated by branching a single logic input Sc for controlling a current output Ia into plural delay circuits DL1-DLn differing in the delay constant, combining each output in a logic circuit part LCa to generate plural kinds of logic pulses having arbitrary pulse widths and phases, and then generating a pulse current by a constant current generating part IGa, and overlapping them. The method for combining each delay circuit for deciding the pulse widths and phases is decided based on an external control signal Slc.