A counter 102 counts the accumulated lighting time or the accumulated
lighting time and the intensity of lighting of each pixel by a first
image signal 101A and stores them in a volatile memory 103 or a
nonvolatile memory 104. A correction circuit 105 corrects the first image
signal based on the correction data stored previously in a correction
data storage section 106 in accordance with the degree of the degradation
of each spontaneous light emitting element by the use of the accumulated
lighting time or the accumulated lighting time and the intensity of
lighting, and produces a second mage signal 101B. By the second image
signal 101B, a display unit 107 can provide a uniform screen having no
variation in luminance even if the light emitting elements in a part of
the pixels are degraded.