PURPOSE: To obtain sufficient access time by reducing the number of times of access in constant scan time by dividing a display image into plural picture element groups in a direction of scanning line, and executing the display process of each picture element group alternately repeatedly.

CONSTITUTION: The addressing of a video RAM 12 is performed so as to designate a first picture element group located at every constant number (n) decided in advance out of the plural picture element groups arranged in the scan direction of the scanning line. Thence, in the next display scan cycle, the addressing is performed so as to designate a second picture element group located at every two groups out of the plural picture element groups and different from the first picture element group. Thereby, the picture element that belongs to the first picture element group is displayed first in a first display period, and in the following second display period, the picture element that belongs to the second picture element group not being designated in the first display period is displayed, and the access in one scan period is performed for the number of times of half the plural groups arranged in the scanning direction.