Patents by Inventor Carl Vernon Brown
Carl Vernon Brown has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7280175Abstract: A bistable nematic liquid crystal device cell is provided with a surface alignment grating on at least one cell wall and a surface treatment on the other wall. Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its groove height to width selected to give approximately equal energy within the nematic material in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell is switched by dc pulses coupling to a flexoelectric coefficient in the material, or by use of a two frequency addressing scheme and a suitable two frequency material. Polarisers either side of the cell distinguish between the two switched states. The cell walls may be rigid or flexible, and are coated with electrode structures, e.g.Type: GrantFiled: February 11, 2004Date of Patent: October 9, 2007Assignee: ZBD Displays LimitedInventors: Guy Peter Bryan-Brown, Carl Vernon Brown, John Clifford Jones
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Patent number: 7265893Abstract: A method of controlling the switching of an optically addressable spatial light modulator (OASLM), to a first surface of which a write light signal is applied and to a second surface of which a read light signal is applied. The method comprises applying a bipolar switching waveform to control electrodes of the (OASLM) during each write cycle such that the leading pulse of the waveform applies a voltage across the (OASLM) which is in the photosensitive direction and the trailing pulse applies a voltage which is not in the photosensitive direction.Type: GrantFiled: October 6, 2003Date of Patent: September 4, 2007Assignee: Qinetiq LimitedInventors: Jonathan Rennie Hughes, Stuart David Coomber, Carl Vernon Brown, Alexander John Topping
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Patent number: 6714273Abstract: A bistable nematic liquid crystal device cell is provided with a surface alignment grating on at least one cell wall and a surface treatment on the other wall. Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its groove height to width selected to give approximately equal energy within the nematic material in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell is switched by dc pulses coupling to a flexoelectric coefficient in the material, or by use of a two frequency addressing scheme and a suitable two frequency material. Polarisers either side of the cell distinguish between the two switched states. The cell walls may be rigid or flexible, and are coated with electrode structures, e.g.Type: GrantFiled: August 6, 2002Date of Patent: March 30, 2004Assignee: QinetiQ LimitedInventors: Guy Peter Bryan-Brown, Carl Vernon Brown, John Clifford Jones
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Publication number: 20030063246Abstract: A bistable nematic liquid crystal device cell is provided with a surface alignment grating on at least one cell wall and a surface treatment on the other wall. Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its groove height to width selected to give approximately equal energy within the nematic material in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell is switched by dc pulses coupling to a flexoelectric coefficient in the material, or by use of a two frequency addressing scheme and a suitable two frequency material. Polarisers either side of the cell distinguish between the two switched states. The cell walls may be rigid or flexible, and any coated with electrode structures, e.g.Type: ApplicationFiled: August 6, 2002Publication date: April 3, 2003Applicant: QINETIQ LIMITEDInventors: Guy Peter Bryan-Brown, Carl Vernon Brown, John Clifford Jones
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Patent number: 6456348Abstract: A bistable nematic liquid crystal device cell is provided with a surface alignment grating on at least one cell wall and a surface treatment on the other wall. Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its groove height to width selected to give approximately equal energy within the nematic material in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell is switched by dc pulses coupling to a flexoelectric coefficient in the material, or by use of a two frequency addressing scheme and a suitable two frequency material. Polarisers either side of the cell distinguish between the two switched states. The cell walls may be rigid or flexible, and are coated with electrode structures, e.g.Type: GrantFiled: December 20, 2000Date of Patent: September 24, 2002Assignee: Qinetiq LimitedInventors: Guy Peter Bryan-Brown, Carl Vernon Brown, John Clifford Jones
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Publication number: 20010028426Abstract: A bistable nematic liquid crystal device cell is provided with a surface alignment grating on at least one cell wall and a surface treatment on the other wall. Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its groove height to width selected to give approximately equal energy within the nematic material in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell is switched by dc pulses coupling to a flexoelectric coefficient in the material, or by use of a two frequency addressing scheme and a suitable two frequency material. Polarisers either side of the cell distinguish between the two switched states. The cell walls may be rigid or flexible, and are coated with electrode structures, e.g.Type: ApplicationFiled: December 20, 2000Publication date: October 11, 2001Applicant: The Secretary of State for DefenceInventors: Guy Peter Bryan-Brown, Carl Vernon Brown, John Clifford Jones
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Patent number: 6249332Abstract: A bistable nematic liquid crystal device cell (1) is provided with a surface alignment grating on at least one cell wall (3) and a surface treatment on the other wall (4). Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its grove height to width selected to give approximately equal energy within nematic material (2) in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell (1) is switched by dc pulses coupling to a flexoelectric coefficient in the material (2), or by use of a two frequency addressing scheme and a suitable two frequency material. Polarizers (13,13′) either side of the cell (1) distinguish between the two switched states. The cell walls (3,4) may be rigid or flexible, and are coated with electrode structures (6,7), e.g.Type: GrantFiled: March 30, 1998Date of Patent: June 19, 2001Assignee: The Secretary of State for Defense in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern IrelandInventors: Guy Peter Bryan-Brown, Carl Vernon Brown, John Clifford Jones
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Patent number: 5917570Abstract: A liquid crystal display cell comprises two cell walls spaced apart to enclose a layer of liquid crystal material. The cell walls carry electrode structures, e.g. arranged in rows and columns to give an x, y matrix of addressable elements or pixels. The liquid crystal material is aligned by a grating (grooved) structure on one or both cell walls. This grating structure is a bigrating with one symmetrical grating and an asymmetric grating which may be orthogonal to the symmetric grating. The grooves of the asymmetric grating varying their depth or asymmetry along the lengths to give a locally varying pretilt whose longer range average provides a pretilt in a preferred range, e.g. about 2-24 degrees.Type: GrantFiled: August 8, 1997Date of Patent: June 29, 1999Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern IrelandInventors: Guy Peter Bryan-Brown, Carl Vernon Brown, Damien Gerard McDonnell