An improved branch-and-bound process of interval arithmetic subdivision in furtherance of computation of rigorous error bounds on integrated digital scene information for two dimensional display is provided. The high-frequency driver circuits drive arrays of ultraviolet lamps in a ballast-free, non-thermionic manner. A moving-mirror beam scanner is used to scan the illumination beam, and a photodetector is used to measure the modulation aspect. The central processing unit initializes a driving condition when the static electricity is applied to the display device and a display operation error occurs. The histogram data acquisition unit detects pixels having the same gradation value from the captured image data, designates an address in the memory that corresponds to the gradation value of the detected pixels, and adds or subtracts an arbitrary value to or from a value stored at the designated address of the memory. At least one of the electrodes is formed from at least surface-silicided hemispherical grain silicon or silicon alloy.