Evaluating digital light processing (DLP) projectors for presenting visual stimuli

Abstract

The purpose of this study is to assess the usefulness of digital light processing (DLP) projectors as hardware for the presentation of visual stimuli, particularly within experiments that require highly accurate control over presentation durations and/or over the timing of successive visual stimuli. DLP (and liquid crystal displays (LCD)) projectors are commonly used within brain function studies. We used an inexpensive commercially-available DLP projector driven by a light emitting diode (LED) light source (NEC NP-L102WJD) and measured both its onset and offset transients and its response delays. The results indicated that the DLP projector could execute more rapid onset and offset transients than an LCD projector, and that transients were even faster than those of a cathode ray tube (CRT) monitor. The response delays of the DLP projector were larger than those of a CRT monitor, but it was confirmed that the duration of the DLP projector delays were always constant. Accordingly, this study concludes that DLP projectors (specifically ones driven by LED light sources) are sufficiently useful tools for visual experiments that require strict temporal control of stimuli presentations, and that they may even be better than CRT monitors when one considers their future availability and applicability to functional studies of the brain.