| 摘要 |
PROBLEM TO BE SOLVED: To prevent the erroneous detection of dust or the like accumulated at the joint of a display belt in a pattern display device for using the display belt and a photosensor. SOLUTION: When the display belt 22 is turned, a brush wipes the display belt 22 and it is possible that the dust or the like removed by the brush is accumulated at the joint 22a of the display belt 22 and forms a stain H. However, since an original point mark 50 itself is originally light-shieldable, a light shielding property is not lost even when the stain H is stuck to the joint 22a, and thus, problems are not generated at all for detecting the original point mark 50 by the photosensor. Also, the photosensor does not malfunction. |
