Sharp Kabushiki Kaisha Corporation

Other

Martin David Tillin

Michael John Towler

Harry Garth Walton

Emma Jayne Walton

Elizabeth Jane Acosta

Kirstin Ann Saynor

Paul Antony Gass

Adrian Marc Simon Jacobs

Sandra Gilmour

Michael Geraint Robinson

Nathan James Smith

Tomoaki Kuratate

Craig Tombling

Henning Molsen

Michel Sagardoyburu

Jonathan Harrold

David James Montgomery

Hiroshi Fukushima

Yuichiro Yamada

Edward P Raynes

Akiyoshi Fujii

Jonathan Francis Mather

Tomoo Takatani

Allan Evans

Paul Bonnett

Koji Yabuta

Diana Ulrich Kean

Grant Bourhill

Nicholas Mayhew

Duncan James Anderson

Harald Reinhart Bock

Tadashi Kawamura

Robert Winlow

Bronje M Musgrave

Brian Henley

James M Ball

Lesley Anne Judge

Margaret Davis Gillian

Zabbie J Acosta

Jonathan P Bramble

Emma Jayne Beynon

Diana U Kean

A display comprises: a single-view image display panel (); and a parallax optic () disposed over a display face of the image display panel for restricting the angular spread of light output from the display face of the image display panel. This enables light to be concentrated in a desired viewing angle range (), and avoids a user () seeing unwanted reflections that may occur as a result of a greater viewing angle range () if the parallax optic () is not provided. The display may be used, as an example, in a motor vehicle to prevent unwanted reflections from the windscreen () of the vehicle.

Display

A liquid crystal cell () comprises a layer () of cholesteric liquid crystal material; and a retarder () disposed in an optical path through the layer () of cholesteric liquid crystal material. The cholesteric liquid crystal material is switchable between a first state in which it cooperates with the retarder () to provide a first viewing angle range and a second state in which it cooperates with the retarder () to provide a second viewing angle range which is smaller than the first viewing angle range. The pitch of the cholesteric liquid crystal material is greater than an intended wavelength of operation of the liquid crystal cell divided by the average refractive index of the liquid crystal material. The liquid crystal cell may be used as a Viewing Angle Restriction (VAR) element, to enable another component, such as a display panel (), to be operated in either a wide viewing mode or a narrow viewing mode.

Liquid crystal cell and display having patterned electrode layer between at least cholesteric liquid crystal and electrode

A transflective liquid crystal display () comprises a liquid crystal cell () disposed between a front substrate () and a rear substrate (), a front polarizer () located in front of the front substrate () and a rear polarizer () located behind the rear substrate (), a front retarder () located between the front substrate () and the front polarizer (), a rear retarder () located between the rear substrate () and the rear polarizer (), and a light source () located behind the rear polarizer (). A transflective display having a number of differently colored sequentially flashing backlights is also provided.

Transflective liquid crystal displays with sequentially flashing light sources

A display is provided for switching between a narrow or private viewing mode and a wide or public viewing mode. The display comprises a display device which is controlled to provide display of a desired image or sequence of images. This is associated with a liquid crystal device having at least one liquid crystal layer whose molecules are switchable between a first state providing a first angular viewing range and a second state providing a second angular viewing range which is within and smaller than the first angular viewing range. With the molecules in the second state, the device at least partially blocks light propagating towards part of the first angular viewing range outside the second angular viewing range. The or each liquid crystal layer is in contact with at least one alignment surface, the or each of which comprises a uniform non-patterned alignment surface.

An optical device comprises an input polarizer, a patterned retarderand an output polarizer. The retarderhas regionsand, at least one of which alters the polarization of light from the input polarizer. The output polarizerhas a transmission axissuch that light passing through the regionsandof the retarderand through the output polarizeris matched in amplitude, phase and polarization. Such a device may be used as a switchable parallax barrier with an LCDto provide a display which is switchable between an autostereoscopic 3D mode and a 2D mode with the 2D mode having more uniform intensity across the display.

Optical device and display operating in two dimensional and autostereoscopic three dimensional modes

A display is provided for providing a restricted viewing mode, for example a private viewing mode where the display may be viewed from a limited region of space by a single viewer and not by other people outside the viewing region. The display comprises a source of polarised light and an output polariser. Between these are provided a controllable pixellated spatial polarisation modulating layer, for example of the liquid crystal type. Also, a polarisation modifying layer is provided between the polarisers and is spaced from the modulating layer. The modifying later comprises a plurality of sets of regions with the regions of each set having the same polarisation modifying effect and the regions of different sets having different polarisation modifying effects. The light path between the modulating layer and the modifying layer is polariser-free. A controller supplies modified image data to compensate for the effect of each region through which light from one or more associated pixels passes to the viewing region so that a viewer in the viewing region sees the displayed image. Outside the viewing region, light passes through regions for which the pixels receive uncompensated data so that the image is obscured or corrupted and is not visible. The modifying layer may be disablable in order to provide a public viewing mode for viewers throughout a wide viewing region.

Display having particular polarisation modifying layer

A method is provided that allows simultaneous control of macroscopic azimuthal and zenithal liquid crystal alignment (&#x3c6;, &#x3b8;) across a liquid crystal layer by controlling the area ratios between first, second and third different types of alignment region (T, T, T) in a patterned alignment layer, the three different types of alignment region (T, T, T) tending to induce liquid crystal alignment in the liquid crystal layer in three different respective, non-coplanar, principal orientations (z, x, y). In the illustrated example, the first type of alignment region (T) tends to induce substantially homeotropic alignment (in the z direction) and the second and third types of alignment region (T, T) tend to induce substantially planar alignment in different, orthogonal, principal orientations (in the x and y directions). Control of macroscopic zenithal liquid crystal alignment (&#x3b8;) is achieved by controlling the area ratios between the homeotropic (T) and planar region types (T, T), and control of macroscopic azimuthal liquid crystal alignment (&#x3c6;) is achieved by controlling the area ratio between the two planar region types (T, T).

Control of liquid crystal alignment in an optical device

A polarization rotator is provided for rotating the polarization direction of linearly polarized light by any arbitrary angle other than 90&#xb0;. The device comprises a layer of liquid crystal material disposed between alignment surfaces. In one mode, a 90&#xb0; twist is induced in the liquid crystal director. An expression is provided for relating the retardation of the layer to the amount of polarization rotation and the angle between the polarization direction of incident light and the alignment direction at the input side of the liquid crystal layer.

Polarization rotator, parallax barrier, display and optical modulator

A liquid crystal device such as a display comprises a twisted liquid crystal layer whose surface director orientation at a first surface is oriented in a first direction and whose surface director orientation at a second surface is oriented in a second different non-perpendicular direction. The layer is disposed, for instance, between a linear polarizer and a reflector. A retarder is disposed between the layer and the polarizer and compensates for residual retardation of the layer at a first voltage across the layer. For instance, the retarder has a retardation substantially equal to the residual retardation and an optic axis perpendicular to the bisectrix of the orientations.

Liquid crystal device and display

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.

Reflective liquid crystal devices

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&deg; 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 &plus;22.5&deg; and &minus;22.5&deg; to the xz plane. Considering light of wavelength &lgr;&deg; 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. In the case of incident light of wavelengths greater or less than &lgr;&deg;, the output light becomes progressively more linearly polarised as the wavelengths departs to a greater extent from the ideal value, but not to the same extent as would be the case if the device consisted simply of a patterned single layer acting as a quarter plate retarder.

Broadband optical retardation device

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) in the first region of the liquid crystal layer and has a second value (d/p) different from the first value in the second region of the liquid crystal layer. The value (d/p) of the ratio of the thickness d of the liquid crystal layer to the pitch p of the liquid crystal material in the second region of the liquid crystal layer is selected such that, when no voltage is applied across the liquid crystal layer, the liquid crystal state stable in the second region of the liquid crystal layer is topologically equivalent to the desired liquid crystal state.

Liquid crystal display device

A reflective liquid crystal device comprises a polarizer and a mirror between which are disposed several retarder. At least one of the retarders is a variable liquid crystal element whose optic axis is switchable so as to switch the device between a reflective state and a non-reflective state. In the non-reflective state, the total retardance of the retarders between the polariser and the mirror is equal to an odd number of quarter wavelengths for a wavelength at or adjacent the middle of the visible spectrum.

Reflective liquid crystal device

An OCB device comprises upper and lower substrates, each provided with an alignment layer. A liquid crystal layer is provided between the substrates. The lower substrate has a low pre-tilt in regions A and C, so that an H-state is stable in these regions when no voltage is applied across the liquid crystal layer. Region B has a high pre-tilt on the lower substrate, so that a HAN state is stable in region B under zero applied voltage. When a voltage is applied across the liquid crystal lever, a V-state is formed at the interface between the HAN-state and the H-states. This V-state then displaces the H-states in regions A and C. The high pre-tilt region, region B, is acting as a nucleation region. The V-state forms at a lower applied voltage than if the nucleation region is not provided.

Liquid crystal display device and a method of manufacture thereof, and a substrate and a method of manufacture thereof

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Oxfordshire, United Kingdom

Martin David Tillin