Characterization of commercial liquid crystal displays for adaptive pattern projection in industrial profilometry: temporal, spatial, and temperature-dependent properties

Liquid crystal (LC) displays have a growing impact as projectors of adaptive light patterns, in connection with profilometry-based industrial metrology. Displays of the twisted nematic type, with either passive or active matrix, show promise as low-cost displays for this use. We investigated the characteristics of both passive- and active-matrix LC displays, during the development of an adaptive projector for profilometry. The following characteristics of a portable television display and of the computer monitor were tested: contrast, temperature dependency of transmission and contrast, and response speed. The portable television display was found to be better in terms of the above mentioned characteristics for the envisaged usage. In this paper guidelines will be given for the use of these displays and for the development of a temperature control system.