Obstacle detection device and bicycle and helmet using the same

PURPOSE: An obstacle sensor, and a safety bicycle and a safety helmet using the same are provided to detect obstacles on the basis of sounds from the obstacles and to transfer the sounds to a bicycle rider with non-auditory stimulation. CONSTITUTION: An obstacle sensor includes at least one microphone(104), a stimulating unit, and a controlling unit. The microphone detects sounds from obstacles which are generated around a bicycle rider. The stimulating unit stimulates the tactile sense of the bicycle rider. The controlling unit detects the existence of the obstacles and operates the stimulating unit. The stimulating unit transfers tactile signals to either hands or the buttocks of the bicycle rider. The stimulating unit includes a rear vibrating member(121). The rear vibrating member is installed at the saddle(60) of a bicycle.