| 摘要 |
PROBLEM TO BE SOLVED: To change the position of a shape floating up by a light transmission part and a light shielding part of the first surface layer and the second surface layer corresponding to the change of the angle of the line of sight to a plate transparent member, to grasp easily the angle of the line of sight to the plate transparent member, to grasp directly and easily relative relation with an object viewed through the plate transparent member, and to thereby grasp accurately the distance to the object. SOLUTION: On one side of the plate transparent member 11, the first surface layer 12 is provided, wherein the first light transmission parts 12a having a high light transmittance and the first light shielding parts 12b having a low light transmittance, having approximately the same length respectively in the vertical direction, are formed alternately, and the width in the horizontal direction of each first light transmission part 12a is formed to be constant or to increase or decrease gradually, and the width in the horizontal direction of each first light shielding part 12b is formed to be constant or to increase or decrease gradually. On the other side of the plate transparent member 11, the second surface layer 13 is provided, having the two or more second light shielding parts 13b formed on positions facing to the first light transmission parts 12a of the first surface layer 12 in the thickness direction of the plate transparent member 11. An interference effect between the first light transmission parts 12a of the first surface layer 12 and the second light shielding parts 13b of the second surface layer 13 is generated as shown in (B)-(D) according to the difference of the line of sight among A-C. COPYRIGHT: (C)2005,JPO&NCIPI
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