High-speed projector as a tool of visual psychophysical experiments(<Special issue>VR Psychology VI)

Abstract

In visual psychophysics, a CRT monitor has been widely used to present visual stimuli, while its temporal resolution was limited by its frame length of about 5 ms (i.e., refresh rate of 200 Hz). Recently, however, a high speed DLP projector was introduced to the market, which realizes much shorter frame length (〜 0.2 ms) for binary images. For such projectors, moreover, the duty ratio of the optical images can be manipulated, which makes it possible to investigate the mechanism of human temporal visual processing which cannot be accessed with the conventional visual devices. In this paper, we explain some temporal properties of the projector essential to the psychophysical experiments and show an example of experimental setup made in combination of the projector with a programming library for psychophysical experiments.