20120236262 | HIGH PRECISION CONTRAST RATIO DISPLAY FOR VISUAL STIMULUS - Embodiments of the present invention include approaches for controlling light valve devices to improve the range and precision of the contrast ratio and the grayscale levels of a display used for visual field tests. In one embodiment, two or more illumination devices are used to enable the display device to display a wide range of contrast stimuli at precise illumination intensities over a fixed background illumination level. In another embodiment, the gamma curves of the display elements are adjusted to allow greater variations in the brightness of the display. | 09-20-2012 |