BRACKET OF VEHICULAR DOOR MIRROR

PROBLEM TO BE SOLVED: To reduce cost, weight and size, and to restrain blurring of an image screen of a mirror at vehicle traveling time by satisfying a specific value or less in resonance power under a condition where a forced vibration response determined by specific expressions in not more than a forced frequency specific value in a resonance phenomenon of a bracket caused by travel vibration. SOLUTION: In this bracket of a mirror, in the case of expressing periodic vibration transmitted from the car body side by acowsωt (a is amplitude, and ωis a frequency), when W(L) determined by equations I through IV (in the respective equations, W(L) is a forced vibration response of a part separate by L from the fixed side; λ is a natural mode; (k) is a spring constant; (f) is a frequency of a vehicle; E is a longitudinal elastic modulus of a synthetic resin composition; I is the cross-sectional secondary moment; ρ is density of the synthetic resin composition; and A is the cross-sectional area of the bracket) satisfies resonance power not more than 20 times under a confition of a forced frequency not more than 120 Hz, blurring of an image screen can be restrained to a reference value or less to thereby obtain an inexpensive door mirror for reducing vibration at vehicle traveling time even if it is made of a synthetic resin.