Abstract: A metastable light attenuator includes an electrophoretic cell having spaced-apart first and second electrodes, and electrophoretic ink therebetween including charged particles. A programmable controller applies signals to the electrodes generating an intermittent electric field across the ink to drive particles to one of a first extreme light state in which particles are maximally spread within the cell in the path of light through the cell to strongly attenuate light transmitted through the cell, or a second extreme light state in which particles are maximally concentrated within the cell and removed from the path of light through the cell and to substantially transmit light through the cell, or two or more light states intermediate the first and second light states. The controller applies intermittent signals to the electrodes to drive the particles from one intermediate state to a second intermediate state within a light transmittance range defined by the two intermediate light states to avoid flashing.

Abstract: A light attenuator comprises a cell comprising a first substrate and a second substrate spaced apart from the first substrate. A layer between the substrates contains an electrophoretic ink, a surface of the layer adjacent the second substrate comprising a monolayer of closely packed protrusions projecting into the layer. The protrusions have surfaces defining a plurality of depressions in the volumes there between.

Abstract: A light attenuator comprises a cell comprising a first substrate and a second substrate spaced apart from the first substrate. A layer between the substrates contains an electrophoretic ink, a surface of the layer adjacent the second substrate comprising a monolayer of closely packed protrusions projecting into the layer. The protrusions have surfaces defining a plurality of depressions in the volumes there between.

Abstract: An electrophoretic device comprises a first electrode and a second electrode spaced apart from the first electrode, and between the electrodes an electrophoretic cell containing an electrophoretic ink and one or more non-planar solid polymer elements. The ink includes charged particles of at least one type suspended in a suspending fluid, and, 75% or more by mass of the suspending fluid is an organosilicone or an aliphatic hydrocarbon and the solid polymer is a fluorinated elastomeric polymer.

Abstract: A light attenuator comprises a cell comprising a first substrate and a second substrate spaced apart from the first substrate. A layer between the substrates contains an electrophoretic ink, a surface of the layer adjacent the second substrate comprising a monolayer of closely packed protrusions projecting into the layer. The protrusions have surfaces defining a plurality of depressions in the volumes there between.

Abstract: A light attenuator comprises a cell comprising a first substrate and a second substrate spaced apart from the first substrate. A layer between the substrates contains an electrophoretic ink, a surface of the layer adjacent the second substrate comprising a monolayer of closely packed protrusions projecting into the layer. The protrusions have surfaces defining a plurality of depressions in the volumes there between.

Abstract: A light attenuator comprises a cell comprising a first substrate and a second substrate spaced apart from the first substrate. A layer between the substrates contains an electrophoretic ink, a surface of the layer adjacent the second substrate comprising a monolayer of closely packed protrusions projecting into the layer. The protrusions have surfaces defining a plurality of depressions in the volumes there between.

Abstract: An electrophoretic device comprises a first electrode and a second electrode spaced apart from the first electrode, and between the electrodes an electrophoretic cell containing an electrophoretic ink and one or more non-planar solid polymer elements. The ink includes charged particles of at least one type suspended in a suspending fluid, and, 75% or more by mass of the suspending fluid is an organosilicone or an aliphatic hydrocarbon and the solid polymer is a fluorinated elastomeric polymer.

Abstract: A road vehicle capable of autonomous driving has a windshield (10) and a control system (30) being configured to selectively control a regular visible light transmittance of the windshield (10) between two or more electrically switchable light states that provide respective levels of visual access through the windshield (10) from outside the vehicle according to a driving context for the vehicle.

Abstract: A switchable light modulator device comprises a fluid layer disposed between opposite spaced apart major surfaces of first and second substrates. Each of the substrates comprise first and second interoperable microstructures formed on the opposite major surfaces. The respective microstructures fit together to join the first and second substrates and to define wall portions for a plurality of cavities, the cavities sealing said fluid in discrete volumes.

Abstract: A road vehicle capable of autonomous driving has a windshield (10) and a control system (30) being configured to selectively control a regular visible light transmittance of the windshield (10) between two or more electrically switchable light states that provide respective levels of visual access through the windshield (10) from outside the vehicle according to a driving context for the vehicle.

Abstract: An electrophoretic device (101) comprises a first electrode (60) and a second electrode (60) spaced apart from the first electrode (60). An electrophoretic cell (809) containing an electrophoretic ink (830) and one or more optically-transparent, non-planar, solid polymer elements (808) is located between the electrodes (60). The ink (830) includes charged particles (11) of at least one type suspended in an optically-transparent suspending fluid (820). The refractive indices of the solid polymer elements (808) and the suspending fluid (820) are matched to have a difference of less than 0.0075, and for half or more of the operating temperature range of the device (0° C.-70° C.), the thermo-optic coefficients (temperature coefficient of refractive index per Kelvin) of the solid polymer elements (808) and the suspending fluid (820) are matched to have an arithmetic-mean difference of less than 0.0002/K in magnitude.

Abstract: A light attenuator comprises a cell comprising a first substrate and a second substrate spaced apart from the first substrate. A layer between the substrates contains an electrophoretic ink, a surface of the layer adjacent the second substrate comprising a monolayer of closely packed protrusions projecting into the layer. The protrusions have surfaces defining a plurality of depressions in the volumes there between.

Abstract: An electrophoretic light attenuator comprises a cell including a first substrate (90), a second substrate (90) spaced apart from the first substrate, a layer arranged between the substrates and containing an electrophoretic ink (30), and a monolayer of closely packed protrusions (2) projecting into the electrophoretic ink (30) and arranged adjacent a surface of the second substrate. The protrusions (2) have surfaces defining a plurality of depressions between adjacent protrusions. The ink (30) includes charged particles (11) of at least one type, the particles being responsive to an electric field applied to the cell to move between a first extreme light state, in which the particles (11) are maximally spread within the cell so as to lie in the path of light through the cell and thus strongly attenuate light transmitted from one substrate to the opposite substrate, and a second extreme light state, in which the particles (11) are maximally concentrated within the depressions so as to let light be transmitted.

Abstract: A switchable light modulator device comprises a fluid layer disposed between opposite spaced apart major surfaces of first and second substrates. Each of the substrates comprise first and second interoperable microstructures formed on the opposite major surfaces. The respective microstructures fit together to join the first and second substrates and to define wall portions for a plurality of cavities, the cavities sealing said fluid in discrete volumes.

Abstract: An electrophoretic insulated glass unit (IGU) comprises an electrophoretic laminate and a pane spaced apart from the electrophoretic laminate, the respective inner faces of the laminate and the pane defining a sealed cavity there between. An outer face of the electrophoretic laminate is in contact with an environment. One inner face of the cavity has a coating that is transparent to visible light and which rejects infrared light greater than a cut-off wavelength.

Abstract: An electrophoretic device (101) comprises a first electrode (60) and a second electrode (60) spaced apart from the first electrode (60). An electrophoretic cell (809) containing an electrophoretic ink (830) and one or more optically-transparent, non-planar, solid polymer elements (808) is located between the electrodes (60). The ink (830) includes charged particles (11) of at least one type suspended in an optically-transparent suspending fluid (820). The refractive indices of the solid polymer elements (808) and the suspending fluid (820) are matched to have a difference of less than 0.0075, and for half or more of the operating temperature range of the device (0° C.-70° C.), the thermo-optic coefficients (temperature coefficient of refractive index per Kelvin) of the solid polymer elements (808) and the suspending fluid (820) are matched to have an arithmetic-mean difference of less than 0.0002/K in magnitude.

Abstract: An electrophoretic insulated glass unit (IGU) comprises an electrophoretic laminate and a pane spaced apart from the electrophoretic laminate, the respective inner faces of the laminate and the pane defining a sealed cavity there between. An outer face of the electrophoretic laminate is in contact with an environment. One inner face of the cavity has a coating that is transparent to visible light and which rejects infrared light greater than a cut-off wavelength.

Abstract: An electrophoretic light attenuator comprises a cell including a first substrate (90), a second substrate (90) spaced apart from the first substrate, a layer arranged between the substrates and containing an electrophoretic ink (30), and a monolayer of closely packed protrusions (2) projecting into the electrophoretic ink (30) and arranged adjacent a surface of the second substrate. The protrusions (2) have surfaces defining a plurality of depressions between adjacent protrusions. The ink (30) includes charged particles (11) of at least one type, the particles being responsive to an electric field applied to the cell to move between a first extreme light state, in which the particles (11) are maximally spread within the cell so as to lie in the path of light through the cell and thus strongly attenuate light transmitted from one substrate to the opposite substrate, and a second extreme light state, in which the particles (11) are maximally concentrated within the depressions so as to let light be transmitted.

Abstract: A method of manufacturing a reflective display device comprises depositing an electro-optical ink on a substrate, the electro-optical ink comprising a plurality of microencapsulated electro-optical fluid shells dispersed in a polymer pre-cursor. The electro-optical ink is cured to provide an electro-optical layer in which the shells are maintained in a polymer matrix having at least two-phases. At least one of the phases in the polymer matrix has a refractive index differing from the shells. At least one electrode is provided in contact with the electro-optical layer to, in use, control the state of the electro-optical layer.