Optical switching element and image display device

Abstract

The present invention provides an optical switching element causing less loss of light and permitting high response, thinning of an optical system for illumination, and the realization of an image display device exhibiting precise grayscale properties. In the optical switching element, an extraction surface of a light extraction unit mounted to a thin film is brought into contact with the total reflection surface of a light guide serving as a light guide unit comprising a glass plate or the like for transmitting light by total reflection, or near at a distance from the total reflection, surface for allowing extraction of evanescent waves, to extract the incident light transmitted through the light guide and emit the extracted light to the outside through an emission member. Such optical switching permits the light extract unit to be operated in a range of approximately a wavelength or half a wavelength, thereby providing an optical switching element capable of high-speed operation and having high contrast because the incident light does not leak due to total reflection during an off time.

Dependencies are inferred from the claim text.