DEVICE AND METHOD FOR IMAGE FORMING

PROBLEM TO BE SOLVED: To provide an image forming device using surface conductive type electron releasing elements in which gradation display characteristic is superior and color slurring, color unbalance and the like in a colored image are easily controlled on the image receiver side and a method for image formation. SOLUTION: NTSC signals are converted into RGB signals by a matrix circuit 314 and gamma correcting circuits 313 and 315. At that time, the conversion is conducted so that nonlinearity in light emitting luminance characteristics of the phosphors of respective colors are corrected. A pulse width modulating circuit 316 executes pulse width modulation for the signals in which nonlinearity of the phosphor light emitting luminance characteristic is linearly corrected. At that time, signals to be superimposed to respective color signals are determined so that deviation in the light emitting luminance characteristics for every phosphor that are linearly converted is corrected. Based on the determined signals, electron beams are edited and the phosphors are irradiated with the electron beams.