An image display device comprises a unit which divides one line into a plurality of blocks (blocks A, B, and C) in a horizontal direction and detects in parallel, a unit which collectively detects a plurality of lines (lines A and B) in a vertical direction in parallel. The unit detects a pixel state of a pixel of the block (for example, block A) and a pixel state of the same pixel as an adjacent block (for example, block B), and corrects a variation between the detection result of the block and the detection result of the adjacent block. The unit detects a pixel state of a pixel through the line (for example, line A) and a pixel state of the same pixel through a different line (for example, line B), and corrects a variation between the detection result of the line and the detection result of the different line.