Sharp Kabushiki Kaisha Corporation

The Secretary of State for Defence in Her Britannic Majesty's Government

Other

Chisso Corporation

Teiyu Sako

Seiichi Mitsui

Mitsuhiro Koden

Akira Sakaigawa

Hideki Uchida

Aya Miyazaki

Masaaki Kabe

Kiyoshi Minoura

Shun Ueki

John Clifford Jones

Masayuki Okamoto

Masahiko Tomikawa

Shinichi Saito

Michael John Towler

Damien Gerard McDonnell

Mitsuhiro Shigeta

Tomoo Furukawa

Paul Antony Gass

Eiji Okabe

Nobuyuki Itoh

Mayumi Tanabe

Takashi Kaneko

Masami Kido

Kazuyuki Kishimoto

Hitoshi Takeda

Hirokazu Sasaki

Ryutaro Mashiko

Mitshuhiro Koden

A display includes a polarizing member and a reflective display element behind an EL element. The EL element self-emits light to display information and doubles as a display-use light source for the reflective display element. In a sufficiently bright environment, ambient light enters a liquid crystal layer after passing through a frontal substrate of the reflective display element, and is reflected from a metal electrode to produce displays. In addition to the direct light from the EL element, light that enters the liquid crystal layer is simultaneously used. In a dark environment, the EL element emits light, and displayed contents are visible owing to the reflection from the metal electrode as well as directly exiting light. The structure makes it possible to provide a novel type of display that allows a user to select one of various display modes at his/her own discretion according to surrounding conditions and that also shows information in a clearly visible fashion, be it outdoors under clear skies or in a dark place, without giving up their thin, lightweight features.

Display

A reflective display device includes a switching layer, placed between substrates, for switching between a transmissive state for allowing transmission of incident light and a scattering state for scattering the incident light, and a retro-reflector for reflecting an incident ray from the liquid crystal layer so that an outgoing ray of the reflected light is parallel to the incident ray. A pitch of smallest unit structures of the retro-reflector is set to be larger than 0 mm and not more than 5 mm. The retro-reflector is preferably in a form of a corner cube array and has light absorbing surface portions at borders of the smallest unit structures. With this reflective display device, brightness of white state and contrast ratio can be improved.

Reflective display device and retro-reflector used therefor

A reflection-type liquid crystal display device includes upper and lower substrates which respectively have upper and lower electrodes, the upper and lower substrates being arranged in parallel with the upper electrode facing the lower electrode, and a liquid crystal layer sandwiched between the upper and lower substrates, the upper substrate being transparent and having protruding portions adjacent to the liquid crystal layer, each protruding portion having a surface downwardly inclined to defined a prism, the lower substrate having light reflection portions and light absorption portions, wherein when an electric field is applied to the liquid crystal layer, incident light into the upper substrate is selectively directed to the light reflection portions and the light absorption portions by means of the protruding portions and the liquid crystal layer.

Reflection-type and transmission-type liquid crystal display devices

A liquid crystal injecting device has a jig which seals an opening used as a liquid crystal inlet of the cell and another opening used as an air outlet of the cell separately. When obtaining a liquid crystal element by injecting liquid crystal into the cell, the liquid crystal is applied to the inlet before the injection, and after an internal pressure of the cell is reduced by releasing air from the jig, the liquid crystal is injected to the cell by being supplied to the inlet through a liquid crystal supplying tube. During the injection, a temperature of the cell is set to a temperature at which the liquid crystal takes a nematic, cholesteric, or isotropic phase, while air is kept being released. When the injection ends, the liquid crystal is further applied to the inlet and outlet, while being reinjected into the cell through all the openings at room temperature or above under atmospheric pressure or above, after which the cell is cooled.

Manufacturing method of liquid crystal element for injecting the liquid crystal into the cell and liquid crystal injecting device

A mixture of a ferroelectric or anti-ferroelectric liquid crystal material and a monomer having a single photopolymeric functional group is injected in the space between two electrode substrates while heat is applied. After cooling of the mixture it is irradiated with ultraviolet light at a temperature at which the liquid crystal material remains in the smectic phase so as to polymerise the monomer. Areas of liquid crystal material requiring different threshold voltages for switching are thereby produced. Alternatively such areas can be produced by changing the conditions applied to a mixture of liquid crystal material with a suitable dopant so as to cause separation of the dopant out of the liquid crystal material in order to provide a polarity of nucleation points for controlling domain formation within the liquid crystal material. Such control of domain formation can be used to provide greyscale in a liquid crystal device.

Liquid crystal display including dopant phase-separated from liquid

A manufacturing method of a liquid crystal display element is provided with the steps of: arranging a pair of insulating substrates face to face with each other and bonding them to each other, each of the insulating substrates having electrodes formed thereon with an alignment film formed in a manner so as to cover the electrodes; and filling the gap between the two substrates with a mixture that is made by mixing a ferroelectric liquid crystal (FLC) composition with isotropic micro structural elements that locally give different threshold-value characteristics to liquid crystal molecules in the liquid crystal composition. With this arrangement, it is possible to provide a liquid crystal layer in which the isotropic micro structural elements are formed into a striped organization with the isotropic micro structural elements being sandwiched between smectic layers of the FLC composition. Consequently, it becomes possible to easily provide a liquid crystal display element with high quality that achieves a gray scale display suitable for practical use.

Manufacturing method of a liquid crystal display element

Monomers with photopolymerization characteristics and an initiator for polymerization are added to a liquid crystal composition having a ferroelectric liquid crystal phase (S5). In a state (S6) where coexist two domains which differ from each other in directions of molecular major axes in the ferroelectric liquid crystal phase, light is projected to the liquid crystal layer to form a polymer reticulate structure therein (S7). As a result, this state is made a stable one and the liquid crystal shows macroscopic switching behaviors among two states causing dark and bright displays respectively, and the above-described state causing halftone display.

Liquid crystal element stabilized by the use of polymer reticulate

A manufacturing method includes a process of once heating a liquid crystal material to a temperature at which an isotropic phase appears therein and then cooling the liquid crystal material, the liquid crystal material being a ferroelectric liquid crystal or antiferroelectric liquid crystal, to be performed under an applied AC electric field which generates an electroclinic effect in a temperature range of from a temperature 20.degree. C. above a phase transition temperature at which a transition in phase occurs from a smectic A phase to a chiral smectic C phase to a temperature 20.degree. C. below the phase transition temperature.

Method of manufacturing liquid crystal display element

A polymer having spontaneous polarization with the same codes as liquid crystal is introduced into a liquid crystal layer of the smectic liquid crystal cell so that the responding speed is improved (second liquid crystal cell). In another way, a polymer having spontaneous polarization with opposite codes to the liquid crystal is introduced into liquid crystal showing .tau.-V.sub.min characteristic so that a driving voltage is lowered (first liquid crystal cell). These polymers are previously added to a liquid crystal composite before injecting into the liquid crystal cell. In another way, after a photochemically polymeric monomer is added to the liquid crystal composite and the obtained product is injected into the liquid crystal cell, the monomer is polymerized by the projection of a light. Furthermore, the liquid crystal cell into which the polymer is introduced is heated again so as to show I phase and is cooled so that the tone display is realized.

Smectic liquid crystal element utilizing spontaneous polarization of

Smectic liquid crystal composition and liquid crystal device

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Kuki, Japan

Teiyu Sako