A vibration watch using a mobile phone for visually impaired people

We have developed a vibration watch on a mobile phone for visually impaired people. This watch has some merits: It operates on a mobile phone which many people are always carrying. It does not have to adjust the time because it uses the time function of the mobile phone which is adjusted automatically. In this paper, first we decided the characteristic of the vibration watch. Next we did a experiment which recognizes the number of times of vibration in order to show the time. We found it was difficult for subjects to recognize five vibration or more. Using a long vibration which means 5 times, we were able to shorten the oscillating interval which can recognize the number of times of vibration. Finaly we constituted the vibration watch on a mobile phone and we had confirmed that the watch function operated.