Evaluation method for reflective LCDs measuring the reflectance corresponding to that measured in an office

Abstract

The reflectance of reflective LCDs strongly depends on illumination. Usually a collimated light source is used for measurements. However we do not use reflective LCDs in such a circumstance in which collimated light impinges onto them. So we propose use of diffused light. We illuminate a reflective LCD uniformly from directions within a cone defined by the specified angle θ, since we assume that illumination in an office is stronger from the normal direction to the LCD. Comparing the measured reflectance with that measured in a typical office, we have found that the reflectance with θ= 30° to 50° corresponds to that measured in the office.