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US 11,686,965 B2Granted
Light control sheet, light control device, and method of controlling the light control sheet
AssigneeToppan Inc.
InventorsToshiji Yasuhara, Takehiro Yamada
Life of this patent
Estimating the term…
Abstract
A light control sheet including a light control layer switchable between a transparent state and an opaque state, and transparent electrode layers sandwiching the light control layer. The light control layer includes a transparent polymer layer that has domains whose average size is 1.0 μm-1.55 μm, and the light control layer includes a liquid crystal composition at a concentration of 37%-55% such that the liquid crystal composition fills the domains.
Claims20
A light control sheet, comprising:
- a light control layer switchable between a transparent state and an opaque state;
- and
- a plurality of transparent electrode layers sandwiching the light control layer such that the plurality of transparent electrode layers is configured to apply voltage to the light control layer for switching between the transparent state and the opaque state,
- wherein the light control layer includes a liquid crystal composition and a transparent polymer layer having a polymer network such that the polymer network is forming a plurality of domains having an average size set in a range of 1.0 μm to 1.55 μm and that the liquid crystal composition is filling the plurality of domains in the transparent polymer layer and has a concentration in a range of 37% to 55%, the light control sheet has a clarity of 71% or less when the light control layer is in the opaque state, and the clarity is calculated by formula 100×(LC−LR)/(LC+LR) where LC is an intensity of straight light propagating along an optical axis of parallel light incident on the light control sheet in light passing through the light control sheet, and LR is an intensity of narrow-angle scattered light propagating at an angle in a range of +2.5° to −2.5° relative to the optical axis of the parallel light.
1 more element
A method of controlling a light control sheet, comprising:
- testing an operational status of a light control layer in a light control sheet,
- wherein the light control sheet includes the light control layer switchable between a transparent state and an opaque state, and a plurality of transparent electrode layers sandwiching the light control layer such that the plurality of transparent electrode layers is configured to apply voltage to the light control layer for switching between the transparent state and the opaque state, the light control layer includes a liquid crystal composition and a transparent polymer layer having a polymer network such that the polymer network is forming a plurality of domains and that the liquid crystal composition is filling the plurality of domains in the transparent polymer layer, the testing includes detecting whether the liquid crystal composition in the light control layer has a concentration of in a range of 37% to 55%, and measuring whether the plurality of domains has an average size in a range of 1.0 μm to 1.55 μm, and the light control sheet has a clarity of 71% or less when the light control layer is in the opaque state, and the clarity is calculated by formula 100×(LC−LR)/(LC+LR) where LC is an intensity of straight light propagating along an optical axis of parallel light incident on the light control sheet in light passing through the light control sheet, and LR is an intensity of narrow-angle scattered light propagating at an angle in a range of +2.5° to −2.5° relative to the optical axis of the parallel light.
Dependencies are inferred from the claim text.