Electro-optical glazing structures having scattering and transparent modes of operation and methods and apparatus for making the same

• US 6,671,008 B1
• Filed: 04/06/2000
• Issued: 12/30/2003
• Est. Priority Date: 11/27/1991
• Status: Expired due to Fees

• Current Assignee: Reveo, Inc.
• Original Assignee: Reveo, Inc.
• Inventors: Li, Jian-Feng, Faris, Sadeg M., Li, Le
• Primary Examiner(s): Ton, Toan
• Assistant Examiner(s): QI, ZHI QIANG
• Application Number:
  US09/544,522
• Time in Patent Office: 1,363 Days
• Field of Search: 349/16, 349/13, 349/92, 349/176, 349/187, 349/79, 349/158
• US Class Current: 349/16
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: C09B 67/0098 Organic pigments exhibiting interference colours, e.g. nacrous pigments
• CPC Class Codes: C09D 11/037 characterised by the pigment
• CPC Class Codes: C09D 11/17 characterised by colouring agents
• CPC Class Codes: C09K 19/00 Liquid crystal materials
• CPC Class Codes: C09K 19/52 characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: C09K 2019/546 creating a polymeric network
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 9/24 Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: F24S 50/80 for controlling collection or absorption of solar radiation
• CPC Class Codes: G01D 11/28 Structurally-combined illuminating devices
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133543 Cholesteric polarisers
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/133623 : Inclined coloured light beams
• CPC Class Codes: G02F 1/13471 : in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells G02F1/13475 takes precedence
• CPC Class Codes: G02F 1/13718 : based on a change of the texture state of a cholesteric liquid crystal
• CPC Class Codes: G02F 1/1393 : the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence
• CPC Class Codes: Y02B 10/20 : Solar thermal
• CPC Class Codes: Y02E 10/40 : Solar thermal energy, e.g. solar towers

Abstract

Electro-optical glazing structures having total-scattering and total-transparent modes of operation which are electrically-switchable for use in dynamically controlling electromagnetic radiation flow in diverse applications.

Claims

1. An electrooptical glazing structure having a transmission mode and a scattering mode, comprising:

an electrically switchable liquid crystal and polymer blend material, disposed between a pair of optically transparent panels, wherein said electrically-switchable liquid crystal and polymer blend material is a polymer network within which non-reactive cholesteric liquid crystal molecules are supported, without the presence of mesogenic groups, and

wherein said electically-switchable liquid crystal and polymer blend material exhibits minimal haze at all viewing angles when operated in said transmission mode.

2. An electro-optical glazing structure having a transmission mode and a scattering mode, comprising:

an electrically switchable liquid crystal and polymer blend material, disposed between a pair of optically transparent panels, wherein the coupling between said polymer network and said non-reactive chiral liquid crystal molecules is sufficient to stabilize said non-reactive cholesteric liquid crystal molecules in the focal coric state, thereby enabling an electric field of relatively low intensity to sufficiently switch all non-reactive liquid crystal molecules along the field direction,

wherein said electrically-switchable liquid crystal and polymer blend material exhibits haze free operation at all viewing angles when operated in said transmission mode.

3. A method of making a PSCT-based device comprising the steps of:

(a) producing first and second sheets of float-type glass for use a pair of glass substrates;

(b) depositing a first electrically-conductive optically-clear layer upon said first sheet of float-type glass, along which a first set of electrically-conductive particles are generated, and depositing a second electrically conductive optically-clear layer upon said second sheet of float-glass, along which a second set of electrically conductive particles are generated;

(c) electrically pre-discharging said first and second sets of electrically conductive particles

(d) depositing a first electrically-insulating optically-clear layer upon said first electrically conductive optically-clear layer, and depositing a second electrically-insulating optically-clear layer upon said second electrically conductive optically-clear layer; and

(e) applying a layer of polymer stabilized cholesteric texture (PSCT) material between said first and second sheets of float-type glass such that said first and second sheets of float-type glass are disposed substantially parallel relative to each other, said layer of PSCT material is disposed between said first and second electrically-insulating optically-clear layers and said first and second electrically-insulating optically-clear layers are disposed beteen said first and second electrically-conductive optically-clear layers.

4. The method of claim 3, wherein during step (b) said first and second electrically-conductive optically-clear layers are made from materials selected from the group consisting of Tin-Oxide, ZnO2, and silver.

5. The method of claim 3, wherein during step (d) said first and second electrically-insulating optically-clear layers are made from materials selected from the group of SiOx.

6. The method of claim 3, wherein said electrically pre-discharging of step (c) involves applying an electric voltage across an empty glass cell formed by said first and second sheets of float-glass and having a gap determined by the bead spacers applied between said first and second sheets.

7. A system for making a PSCT-based device comprising:

a first system componet for producing first and secondsheets of float-type glass for use a pair of glass substrates;

a second system component for depositing a first elcctrically-conductive optically-clear layer upon said first sheet of float-type glass, along which a first set of electrically-conductive particles are generated, and depositing a second electrically conductive optically-clear layer upon said second sheet of float-type glass, along which a second set of electrically conductive particles are generated;

a third system component for depositing a first electrically-insulating optically-clear layer upon said first electrically conductive optically-clear layer, and depositing a second electrically-insulating optically-clear layer upon said second electrically conductive optically-clear layer;

a fourth system component for applying a layer of polymer stabilized cholesteric texture (PSCT) material between said first and second sheets of float-type glass such that said first and second sheets of float-type glass are disposed substantially parallel relative to each other, said layer of PSCT material is disposed between said first and second electrically-insulating optically-clear layers and said first and second electrically-insulating optically-clear layers are disposed between said first and second electrically-conductive optically-clear layers; and

a fifth system component for electrically pre-discharging said first and second sets of electrically conductive particles.

8. The system of claim 7, wherein said first and second electrically-conductive optically-clear layers are made from materials selected from the group consisting of Tin-Oxide, ZnO2, and silver.

9. The system of claim 7, wherein said first and second electlically-insulating optically-clear layers are made from materials selected from the group of SiOx.

10. The system of claim 7, wherein said fifth system component comprises means for applying an electric voltage across an empty glass cell formed by said first and second sheets of float-glass and having a gap determined by the bead spacers applied between said first and second sheets.

11. An electrically-switchable PSCT-based signage panel for producing a signage work under electronic control comprising:

first and second substrate, arranged in a substantially parallel manner with a gap disposed therebetween;

a patterned electrically-conductive optically-clear electrode layer formed on said first substrate, having an imaging-conveying portion and a background portion, configured in accordance with the geometrical characteristics of said signage work to be produced;

an unpatterned electrically-conductive optically-clear electrode layer formed on said second substrate;

a PSCT layer disposed within said gap, and between said patterned electrically-conductive optically-clear electrode layer formed on said first substrate, and said unpatterned electrically-conductive optically-clear electrode layer formed on said second substrate;

a plurality of electrical connections formed between said imaging-conveying portion, said background portion, and said unpatterned electrically-conductive optically-clear electrode layer; and

a plurality of control switches for applying, from a voltage source, control voltages to said image-conveying portion, said background portion, and said unpatterned electrically-conductive optically-clear electrode layer, so as to cause liquid crystals embodied with said PSCT layer to align in either the focal conical state during said translucent state of panel operation, or in a homeotropic state during said transparent state of panel operation, producing said signage work.