PROBLEM TO BE SOLVED: To improve trouble detection output of visual examination or to prevent lowering of trouble detection output due to aging.SOLUTION: A display control part 12 displays a visual examination and training table including a character order picking table where a plurality of characters whose certain order is known are arrayed irregularly and/or a graphic locating table where a plurality of graphics are arrayed irregularly, which is stored by a storage part 13, on a display part 15. A timing part 14 starts to measure the lapsed time when the display control part 12 displays the visual examination and training table on the display part 15, and informs the display control part 12 on the passage of a predetermined training time. The display control part 12 ends display of the visual examination and training table now displayed on receiving the information.
