Patent ES-8404521-A1 (ES)
Title: Encapsulated nematic liq. crystal material and encapsulation method
IPC: G09F9/35
Filed: 1983-03-07
Abstract: Discrete quantities of an operationally nematic liq. crystal material having positive dielectric anisotropy are encapsulated in a medium that tends to align the liq. crystal material w.r.t. the medium. The liq. crystal material is pref. encapsulated in spherical capsules so it tends to align with the encapsulating walls in the absence of an electric  field, distorting the internal structure and causing it to coil in on itself, storing elastic energy in the material. The alignment pref. achieves max. light absorption in a no-field condition. A nematic liq. crystal material is caused to perform independently of the direction of polarisation of incident light by confinement in a capsule causing distortion of the direction of the liq. crystal material. - Display device comprises a substrate supporting encapsulated liq. crystal material as above. Encapsulated liq. crystals are made by mixing a binder medium and nematic liq. crystal material, pref. with a pleochroic dye dissolved in the liq. crystal material. - The encapsulated liq. crystal material may be used for large displays, with no limitation on size. The displays have wide viewing angle, fast response time (e.g. 2ms on, 4ms off), and good contrast ratio (e.g. 7:1 for 50V across 1.6 mil thick film capsules, contg. black pleochroic dye). EPAB- EP--88126 B A liquid crystal device comprising liquid crystal material and containment means therefore for inducing a distorted alignment of said liquid crystal material, and which in the absence of a field input and in response to such alignment scatters and/or absorbs light, the ordinary index of refraction of the liquid crystal material and the index of refraction on the containment means being substantially identical so that in response to a field input the amount of scattering and/or absorption is reduced, the containment means including therein a plurality of volumes of liquid crystal material, the containment means having non-planar wall means that tends to distort at least some of the liquid crystal material. (Dwg.2/7) - EP--88126 B A liquid crystal device comprising liquid crystal material and containment means therefor for inducing a distorted alignment of said liquid crystal material, and which in response to such alignment scatters and/or absorbs light and which in response to an input reduces the amt of scattering and/or absorption.  (17pp) - EP--88126 B A liquid crystal device comprising liquid crystal material and containment means therefore for inducing a distorted alignment of said liquid crystal material, and which in the absence of a field input and in response to such alignment scatters and/or absorbs light, the ordinary index of refraction of the liquid crystal material and the index of refraction on the containment means being substantially identical so that in response to a field input the amount of scattering and/or absorption is reduced, the containment means including therein a plurality of volumes of liquid crystal material, the containment means having non-planar wall means that tends to distort at least some of the liquid crystal material. (Dwg.2/7) - EP--88126 B A liquid crystal device comprising liquid crystal material and containment means therefor for inducing a distorted alignment of said liquid crystal material, and which in response to such alignment scatters and/or absorbs light and which in response to an input reduces the amt of scattering and/or absorption. (17pp) - EP-122737 B An apparatus for controllably affecting the transmission of light comprising liquid crystal material (30,133;201) microencapsulated in a containment medium (33,132), a support (12) for supporting said liquid crystal material (30,133,201) and means (13,14) for applying an electric field to said liquid crystal material, characterised in that the liquid crystal material (30,133,201) is operationally nematic, and is operative for selectively primarily, in the absence of the field, scattering light or, in response to the field, transmitting light and wherein the apparatus further comprises a reflecting means (18,19,80,19') for effecting total internal reflection of light scattered by said liquid crystal material (30,133,201) back to this liquid crystal metal (30,133,201), the aparatus being operative such that unscattered light substantially is not totally internally reflected. (Dwg.1/16) - EP-122737 B An apparatus for controllably affecting the transmission of light comprising liquid crystal material (30,133;201) microencapsulated in a containment medium (33,132), a support (12) for supporting said liquid crystal material (30,133,201) and means (13,14) for applying an electric field to said liquid crystal material, characterised in that the liquid crystal material (30,133,201) is operationally nematic, and is operative for selectively primarily, in the absence of the field, scattering light or, in response to the field, transmitting light and wherein the apparatus further comprises a reflecting means (18,19,80,19') for effecting total internal reflection of light scattered by said liquid crystal material (30,133,201) back to this liquid crystal metal (30,133,201), the aparatus being operative such that unscattered light substantially is not totally internally reflected. (Dwg.1/16) GBAB- GB2128626 B Liquid crystal apparatus, comprising liquid crystal material, and - a containment medium having surface means for inducing a distorted alignment of said liquid crystal material which in response to such alignment at least one of scatters and absorbs light and which in response to a prescribed input of a magnetic or electric field reduces the amount of such scattering or absorption.a - GB2128626 B Liquid crystal apparatus, comprising liquid crystal material, and - a containment medium having surface means for inducing a distorted alignment of said liquid crystal material which in response to such alignment at least one of scatters and absorbs light and which in response to a prescribed input of a magnetic or electric field reduces the amount of such scattering or absorption.a USAB- US4435047 A Encapsulated liq. crystal device is described using material having a positive dielectric anisotropy and surface means inducing a distorted alignment in the absence of an electric field to reduce optical transmission independent of polarisation. The material is responsive to the presence of an electric field to increase the optical transmission. - Also claimed is a method of making encapsulated nematic liq. crystals in which an encapsulating material, a nematic crystal material and a pleochroic dye are mixed together. - The material can be used over a large area whilst maintaining high quality of operation and controlled uniformity of output.  (15pp)o - US4435047 A Encapsulated liq. crystal device is described using material having a positive dielectric anisotropy and surface means inducing a distorted alignment in the absence of an electric field to reduce optical transmission independent of polarisation. The material is responsive to the presence of an electric field to increase the optical transmission. - Also claimed is a method of making encapsulated nematic liq. crystals in which an encapsulating material, a nematic crystal material and a pleochroic dye are mixed together. - The material can be used over a large area whilst maintaining high quality of operation and controlled uniformity of output.  (15pp)o - US4605284 A A liquid crystal unit comprises a containment for inducing non-parallel alignment of the liquid crystal material which in response scatters and/or absorbs light and in response to a given input reduces the amount of such scattering or absorption, with the materail and containment comprising a dispersion. - The containment (22) may encapsulate the crystal material (20) to give vols. of 5-15 microns diameter, and the dispersion may be formed at a layer 0.3-10 mils thick or several layers of capsule-like vols. thick. A layer is pref. carrier on a substrate (12) with an electrode (13) between layer and  substrate and a second (14) on the opposite side of the layer. The first layer covers the entire substrate and the second only selected parts of the layer.