A consideration of shape of sensor holder for portable Braille reading sensor

Automatic Braille reading systems have been developed and they are put in the Braille library. However, the system is larger scale and it is difficult to carry everywhere. In this paper we introduce a portable Braille reading system, which consists of sensing unit and processing unit. The sensing unit consists of three plate springs and strain gages. This unit detects convex points of Braille, and the processing unit converts it to corresponding letters. In order to scan the Braille by the plate spring appropriately, a sensor holder of suitable shape is required. This paper considers a shape of the plate spring holder. Four basic shape of sensor holder are compared by electromyogram (EMG) and contact pressure of fingers.