Shape identification performance and pin-matrix density in a 3 dimensional tactile display

Tactile display devices use an array of pins mounted in the form of a matrix to present three-dimensional shapes to the user by raising and lowering the pins. With a denser matrix of mounted pins, it can be expected that shape identification will become easier and the time required for identification will also become shorter, but that problems of difficulty in fabrication will arise. It is necessary to consider such trade-offs in the development of such devices. The authors conducted experiments to study the effect of pin pitch on shape identification as part of the fundamental investigation of this subject. The experiment used three tactile display devices with pin pitches of 2 mm, 3 mm and 5 mm for geometrical shape identification, with response time and rate of misidentification taken as the performance data. Surfaces, edges and vertices of three-dimensional shapes were used as the shape primitives for displayed shapes and several of each type were selected for presentation. The results obtained revealed that performance has different relationships to pin pitch with different shape primitives.