Abstract: An optical sheet, a screen, and a display apparatus capable of reducing speckles are provided. An optical sheet (50) includes a particle layer (55) including a transparent retaining part (56) having a predetermined thickness and a particle (60) that is accommodated in a cavity (56a) formed in the retaining part (56) and includes a first portion (61) and a second portion (62) having different dielectric constants. The first portion (61) includes a transparent first main portion (66a) and a first diffusion component (66b) that diffuses light. The second portion (62) includes a transparent second main portion (67a) and a second diffusion component (67b) that diffuses light. The first diffusion component (66b) and the second diffusion component (67b) have a diameter d satisfying the following conditional expression (1): 0.1 ?m?d?15 ?m (1).

Abstract: There is provided a screen capable of sufficiently reducing speckles. A screen for displaying an image by being irradiated with a light beam from a projector, is provided with a plurality of particles each including a first part and a second part different in dielectric constant, a particle layer having the plurality of particles, and electrodes which form an electric field for driving the particles of the particle layer by applying a voltage to the particle layer.

Abstract: An illumination device has a coherent light source, an optical device that diffuses the plurality of coherent light beams and illuminates a predetermined illumination area, and a timing control unit that individually controls incident timing of the plurality of coherent light beams to the optical device or illumination timing of the illumination area, wherein the optical device has a plurality of diffusion regions, the diffusion regions being provided corresponding to the plurality of coherent light beams, the plurality of diffusion regions illuminate the illumination range by diffusion of incident coherent light beams, the plurality of diffusion regions have a plurality of element diffusion regions, the plurality of element diffusion regions illuminate partial regions in the illumination area by diffusion of incident coherent light beams, and at least parts of the partial regions illuminated by the plurality of element diffusion regions are different from one another.