According to an aspect, a display apparatus includes: a first light-transmissive substrate; a second light-transmissive substrate arranged to face the first light-transmissive substrate; a liquid crystal layer including polymer dispersed liquid crystals sealed between the first light-transmissive substrate and the second light-transmissive substrate; at least one light-emitting device arranged to face at least one of a side surface of the first light-transmissive substrate or a side surface of the second light-transmissive substrate; and at least one reflector arranged on at least one of a side surface of the first light-transmissive substrate or a side surface of the second light-transmissive substrate, the side surface of the first or second light-transmissive substrate being on an opposite side of the side surface of the first or second light-transmissive substrate to which the at least one light-emitting device faces, and configured to reflect light at the side surface on the opposite side.

A display apparatus includes a coherent light source, a display unit, a light-diffusing element, and at least one optical element. The coherent light source is configured to provide coherent light beams. The display unit is configured to form a three-dimensional image beam based on interference of the coherent light beams, wherein the three-dimensional image beam is imaged on an intermediate imaging surface after passing through the display unit. The light-diffusing element is located on the intermediate imaging surface, wherein a diffusion angle of the three-dimensional image beam is sequentially changed by passing through the light-diffusing element. The at least one optical element is located on a transmission path of the three-dimensional image beam from the light-diffusing element, and is configured to project the three-dimensional image light beam passing through the display unit out of the display apparatus to display a three-dimensional image.

A device having variable scattering by liquid crystals includes a stack with a first electrode, an electroactive layer with liquid crystals being stabilized by the polymeric network, and a second electrode. The material exhibits, from a temperature referred to as T1, a mesophase referred to as P. At a temperature T′ greater than or equal to T1, the stack is capable of exhibiting at least three stable and reversible scattering states in the visible range and a variable color.

A fast spectral modulator for modulating intensity, phase, and spectrum of light beam, is described in the present invention. The spectral modulator comprises at least one liquid crystal composite and a photonic structure. Said at least one liquid crystal composite is made of a liquid crystal and porous microparticles infiltrated within said liquid crystal, wherein: (i) said porous microparticles have an average refractive index approximately equals to one of the liquid crystal principal refractive indices; and (ii) concentration of said microparticles in said composite is less than 0.1% for avoiding significant light scattering.

An electrical characteristic of a privacy glazing structure and indicative of a health of the privacy glazing structure can be measured at a first time and at a second time later than the first time. In response to detecting a change in the electrical characteristic indicating a change in the health of the privacy glazing structure, one or more parameters of an electrical drive signal can be adjusted to compensate for the change in the health of the privacy glazing structure. The electrical characteristic can be measured at a plurality of times after the second time and compared to the electrical characteristic measured at the first time. If, at any of the plurality of times, the measured electrical characteristic differs from the electrical characteristic measured at the first time by more than a threshold amount, one or more parameters of the electrical drive signal can be adjusted.

A novel display device that is highly convenient, useful, or reliable is provided. The display device includes a light guide plate, a display panel, and an intermediate layer, and the light guide plate includes a first surface and a second surface. The first surface is irradiated with light, the second surface has a function of distributing light, the second surface is in contact with the intermediate layer, and the second surface has a first refractive index N1 in a region in contact with the intermediate layer. The display panel faces the second surface, the display panel is in contact with the intermediate layer, and the display panel has a function of scattering the distributed light. The intermediate layer includes a region positioned between the second surface and the display panel, and the intermediate layer has a second refractive index N2 in a region in contact with the second surface. The second refractive index N2 is smaller than the first refractive index N1.

An apparatus to treat refractive error of an eye comprises an electroactive component configured to switch between a light scattering or optical power providing configuration to treat refractive error of the eye and a substantially transparent configuration to allow normal viewing. The electroactive component can be located on the lens away from a central axis of the lens to provide light to a peripheral region of the retina to decrease the progression of myopia. The electroactive component can be located on the lens away from the central axis of the lens in order for the wearer to view objects through an optical zone while the electroactive component scatters light. The electroactive component can be configured to switch to the substantially transparent configuration to allow light to pass through the electroactive component and to allow the lens to refract light to correct vision and allow normal viewing through the lens.

An apparatus to treat refractive error of an eye comprises an electroactive component configured to switch between a light scattering or optical power providing configuration to treat refractive error of the eye and a substantially transparent configuration to allow normal viewing. The electroactive component can be located on the lens away from a central axis of the lens to provide light to a peripheral region of the retina to decrease the progression of myopia. The electroactive component can be located on the lens away from the central axis of the lens in order for the wearer to view objects through an optical zone while the electroactive component scatters light. The electroactive component can be configured to switch to the substantially transparent configuration to allow light to pass through the electroactive component and to allow the lens to refract light to correct vision and allow normal viewing through the lens.

A privacy glazing structure may include an electrically controllable optically active material, such as a liquid crystal material, sandwiched between a flexible substrate and a rigid substrate. The flexible substrate and the rigid substrate may each have a conductive layer deposited on the surface facing the optically active material. The flexible substrate may be bonded about its perimeter to the rigid substrate and may be sufficiently flexible to conform to non-planarity of the rigid substrate. As a result, the flexible substrate may adopt the surface contour of the rigid substrate to maintain a uniform thickness of optically active material between the flexible substrate and the rigid substrate.

A method for controlling the state of two or more liquid crystal-based switchable windows includes in a first step providing correction data which define a relationship between a state signal and an output voltage level. The correction data is provided for each of the switchable windows and the state of the switchable windows may be adjusted according to the state signal between a minimum and maximum level. In a subsequent step, the state signal is provided which defines the desired state of one or more selected switchable windows. In a further step, a required voltage level is determined for setting the desired state based on the state signal and the respective correction data for each of the one or more selected windows. In a subsequent step d), an AC output voltage is generated having the required voltage level for each of the one or more selected windows.