Patents by Inventor Elizabeth Jane Acosta
Elizabeth Jane Acosta 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: 7259818Abstract: A liquid crystal device comprises a nematic liquid crystal, voltage means for applying a voltage across said liquid crystal, and two substrates (42, 30) each provided with an alignment layer (32, 33), wherein: said liquid crystal is sandwiched between said two substrates (42, 30); said nematic liquid crystal can be placed in at least one operating state and at least one non-operating state, and at least one of said alignment layers (32, 33) is provided with a plurality of surface protrusions (40) formed from an anisotropic material.Type: GrantFiled: March 1, 2002Date of Patent: August 21, 2007Assignee: Sharp Kabushiki KaishaInventors: Michael John Towler, Elizabeth Jane Acosta
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Patent number: 6765640Abstract: A reflective liquid crystal device comprises in sequence a linear polarizer, a retarder arrangement comprising two retarders, and a reflector. A first of the retarders provides a retardation of m&lgr;/2 and a second of the retarders provides a retardation of n&lgr;/4, where m is an integer and n is an odd integer, and wherein at least one of the first and second retarders comprises a Bistable Twisted Nematic (BTN) liquid crystal. This BTN retarder is switchable between a first state in which the retarder provides a retardation of m&lgr;/2 or n&lgr;/4 and a second state in which the retardation is zero.Type: GrantFiled: November 13, 2001Date of Patent: July 20, 2004Assignee: Sharp Kabushiki KaishaInventors: Elizabeth Jane Acosta, Martin David Tillin, Michael John Towler
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Patent number: 6735017Abstract: A broadband optical retardation device, such as may be used for polarisation encoding of display information or in diffractive optical systems, includes a patterned uniform half wave plate retarder in combination with a non-patterned uniform quarter wave plate retarder having an optic axis oriented at 90° to the xz plane. The patterned retarder consists of alternating first and second regions having first and second optic axes at different orientations to a reference axis, for example at +22.5° and −22.5° to the xz plane. Considering light of wavelength &lgr;° incident on the retarder and linearly polarised in the xy plane, such light is differently polarised by the regions, and the light output by the device includes regions in which the light is right circularly polarised and regions in which the light is left circularly polarised.Type: GrantFiled: May 25, 2000Date of Patent: May 11, 2004Assignee: Sharp Kabushiki KaishaInventors: Elizabeth Jane Acosta, Emma Jayne Beynon, Adrian Marc Simon Jacobs, Michael Geraint Robinson, Kirstin Ann Saynor, Martin David Tillin, Michael John Towler, Harry Garth Walton
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Patent number: 6714276Abstract: A liquid crystal display device comprises: a layer of a chiral liquid crystal material disposed between first and second substrates; and means for applying a voltage across the liquid crystal layer. A first region of the liquid crystal layer is an active region for display and a second region of the liquid crystal layer is a nucleation region for generating a desired liquid crystal state in the first region when a voltage is applied across the liquid crystal layer. The ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material has a first value (d/p)A in the first region of the liquid crystal layer and has a second value (d/p)N different from the first value in the second region of the liquid crystal layer.Type: GrantFiled: February 6, 2001Date of Patent: March 30, 2004Assignee: Sharp Kabushiki KaishaInventors: Michael John Towler, Elizabeth Jane Acosta, Harry Garth Walton, Craig Tombling, Martin David Tillin, Brian Henley, Emma Jayne Walton, Tadashi Kawamura, Akiyoshi Fujii, Yuichiro Yamada
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Patent number: 6624863Abstract: A method of making a patterned retarder of the present invention includes the steps of providing an alignment layer rubbing the alignment layer in a first rubbing direction, masking with a mask at least one first region of the alignment layer, to reveal at least one second region of the alignment layer, rubbing the at least one second region through the mask in a second rubbing direction different from the first rubbing direction, removing the mask, disposing on the alignment layer a layer of birefringent material whose optic axis is aligned by the alignment layer, and fixing the optic axis of the birefringent layer.Type: GrantFiled: June 26, 1998Date of Patent: September 23, 2003Assignee: Sharp Kabushiki KaishaInventors: Adrian Marc Simon Jacobs, Elizabeth Jane Acosta, Jonathan Harrold, Michael John Towler, Harry Garth Walton
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Patent number: 6600537Abstract: A pi-cell liquid crystal device comprises a nematic liquid crystal layer (17) disposed between alignment layers (14,15) which provide a pretilt such that, at a zero applied field, the energy of the H-state is less than the energy of the V-state, which is less than the energy of the T-state. A drive arrangement (18) switches the pi-cell by applying a first electric field, at which the energy of the V-state is less than the energy of each of the H-state and the T-state, or a second smaller electric field, at which the energy of the H-state is less than the energy of each of the V-state and the T-state. The T-state may thus be avoided while maintaining high switching speeds.Type: GrantFiled: January 11, 2002Date of Patent: July 29, 2003Assignee: Sharp Kabushiki KaishaInventors: Michael John Towler, Elizabeth Jane Acosta, Harry Garth Walton
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Publication number: 20030067575Abstract: A liquid crystal display device comprises a first substrate, a first alignment layer disposed on a surface of the first substrate, a second substrate, second alignment layer disposed on a surface of the second substrate, and a liquid crystal layer disposed between the first substrate and the second substrate. The alignment direction of the first alignment layer has a non-zero component in a first azimuthal direction in a first region of the alignment layer and has a non-zero component in a second azimuthal direction different from the first azimuthal direction in a second region of the first alignment layer. In consequence, in zero applied electric field across the liquid crystal layer, a first liquid crystal state is stable in a first volume of the liquid crystal layer defined by the first region of the first alignment layer.Type: ApplicationFiled: September 30, 2002Publication date: April 10, 2003Inventors: Elizabeth Jane Acosta, Martin David Tillin, Michael John Towler
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Publication number: 20020126245Abstract: A liquid crystal device comprises a nematic liquid crystal, voltage means for applying a voltage across said liquid crystal, and two substrates (42, 30) each provided with an alignment layer (32, 33), wherein: said liquid crystal is sandwiched between said two substrates (42, 30); said nematic liquid crystal can be placed in at least one operating state and at least one non-operating state, and at least one of said alignment layers (32, 33) is provided with a plurality of surface protrusions (40) formed from an anisotropic material.Type: ApplicationFiled: March 1, 2002Publication date: September 12, 2002Inventors: Michael John Towler, Elizabeth Jane Acosta
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Publication number: 20020093613Abstract: A pi-cell liquid crystal device comprises a nematic liquid crystal layer (17) disposed between alignment layers (14,15) which provide a pretilt ouch that, at a zero applied field, the energy of the H-state is less than the energy of the V-state, which is less than the energy of the T-state. A drive arrangement (18) switches the pi-cell by applying a first electric field, at which the energy of the V-State is less than the energy of each of the H-state and the T-state, or a second smaller electric field, at which the energy of the H-state is less than the energy of each of the V-state and the T-state. The T-state may thus be avoided while maintaining high switching speeds.Type: ApplicationFiled: January 11, 2002Publication date: July 18, 2002Inventors: Michael John Towler, Elizabeth Jane Acosta, Harry Garth Walton
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Publication number: 20020084961Abstract: The disclosed invention relates to a method of operating a liquid crystal display device having a layer of liquid crystal material switchable between first and second liquid crystal states, the method comprising the steps of: (a) applying a first voltage waveform across an addressable area of the liquid crystal layer of the display device to put the addressable area of the liquid crystal layer into the one of the first and second liquid crystal states having the higher energy when no electric field is applied across the liquid crystal layer; and (b) putting the addressable area of the liquid crystal layer into a desired one of the first and second liquid crystal states to obtain a desired display state. A liquid crystal display device is disclosed.Type: ApplicationFiled: September 19, 2001Publication date: July 4, 2002Inventors: Elizabeth Jane Acosta, Michael John Towler
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Publication number: 20010052961Abstract: A liquid crystal display device comprises: a layer of a chiral liquid crystal material disposed between first and second substrates; and means for applying a voltage across the liquid crystal layer. A first region of the liquid crystal layer is an active region for display and a second region of the liquid crystal layer is a nucleation region for generating a desired liquid crystal state in the first region when a voltage is applied across the liquid crystal layer. The ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material has a first value (d/p)A in the first region of the liquid crystal layer and has a second value (d/p)N different from the first value in the second region of the liquid crystal layer.Type: ApplicationFiled: February 6, 2001Publication date: December 20, 2001Inventors: Michael John Towler, Elizabeth Jane Acosta, Harry Garth Walton, Craig Tombling, Martin David Tillin, Brian Henley, Emma Jayne Walton, Tadashi Kawamura, Akiyoshi Fujii, Yuichiro Yamada
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Patent number: 6222672Abstract: An imaging system according to the invention includes: a matrix of light modulating elements including first and second elements for respectively transmitting first and second image components; a polarizing element having a first polarization axis for linearly polarizing light from the first and second elements; a first optical retardation element incorporating at least one first retarder having first and second regions respectively having a first optic axis at a first orientation and a second option axis at a second orientation to the first polarization axis; and a detecting element having first and second detecting parts, each detecting part including respective second optical retardation element incorporating at least one second retarder and an analyzing element having a second polarization axis intended to be disposed at a defined orientation relative to the first polarization axis, at least one second retarder of the first detecting part having an optic axis which is intended to be disposed substantiallyType: GrantFiled: November 24, 1998Date of Patent: April 24, 2001Assignee: Sharp Kabushiki KaishaInventors: Michael John Towler, Harry Garth Walton, Elizabeth Jane Acosta