| 摘要 |
PROBLEM TO BE SOLVED: To improve identification of a display mark by making an outer surface of the display mark provided on a side wall surface in an irregular section provided with a large number of thin grooves extending in a constant direction and arranged in parallel with equal pitches and specifying depth of the striations and a thin groove depth ratio against a pitch between the striations. SOLUTION: A thin groove 4 is formed in an inverted trapezoidal shape, its striation depth (b) is made 1.0mm or less, and a striation depth ratio b/a which is a ratio of the striation depth (b) against a pitch between the striations (a) is made 0.5 or more and 2.2 or less. Additionally, the thin groove 4 is formed to open out at an angleθof 0 degrees or more and 30 degrees or less against a slope line N vertical on a side wall surface 2 with its thin groove wall surface 5. Orientation of these thin grooves 4... is arranged diagonally against a tire radial line. Light irradiating the side wall surface 2 hits a wall of the thin groove 4 in a region of a display mark 3, reflects in a different direction from the side wall surface 2, and a difference of light and darkness from a part out of the region remarkably appears, and identification of the display mark 3 is improved.
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