LIGHT VALVE

摘要

The present invention relates to a light valve (40) for reflecting and diffracting incident light, comprising an electrostatically operable foil (42) provided with a reflective surface (60), a reflective grating structure (52) provided on one side of the foil (42), and means (48, 56, 60) for inducing electrostatic forces on the foil (42) for switching it between a first position, in which the foil is separated from said grating structure (52), whereby incident light (64) received by said light valve (40) will be diffracted by said reflective grating structure (52), and a second position, in which the foil is brought into contact with said grating structure (52), whereby incident light (64) received by said light valve (40) will be essentially specularly reflected by said foil electrode (60). A grating structure having no movable parts may thus be used, which makes the light valve easy to manufacture. The invention also relates to an imaging system comprising at least one such light valve.