Abstract: This invention relates to an image expansion device which comprises an A/D converter, a memory block, a control section, and a D/A converter; said control section is provided with image processing means which performs arithmetic processing by {m(=the number of image equipments arranged in the horizontal direction).times.d(=the image display portion in the horizontal direction of one image equipment)+(m-1).times.(c(=the sum in length of the image display and non-display portion in the horizontal direction of one image display equipment)-d)}.div.d, and {n(=the number of image devices arranged in the vertical direction).times.b(=the image display portion in the vertical direction of one image equipment)+(n-1).times.(a(=the sum in length of the image display and non-display portion in the vertical direction of one image equipment)-b)}.div.b, and then performs expansion processing based on the results of the arithmetic processing.