Abstract: A reflection type liquid-crystal display device has a reflection type liquid-crystal display panel, at least one illuminator, and an optical path control layer. The reflection type liquid-crystal display panel includes a liquid-crystal cell and a reflector, the liquid-crystal cell having a visual-side substrate, a back-side substrate and a liquid crystal. The visual-side substrate includes a transparent substrate, a transparent layer lower in reflective index than the transparent substrate, and a transparent electrode. The back-side substrate has an electrode, and the liquid crystal is held between the visual-side and back-side substrates so that respective electrode sides of the visual-side and back-side substrates are disposed opposite to each other. The reflector is disposed on the back-side substrate side. The illuminator is disposed on one of side surfaces of the reflection type liquid-crystal display panel.

Abstract: An optical film has a transparent film and an adhesive layer provided on one surface of the transparent film. The adhesive layer has a refractive index different by 0.12 or less from that of a layer of the one surface of the transparent film. The transparent film has an average in-plane retardation of not larger than 30 nm. A repetitive prismatic structure is provided on the other surface of the transparent film, the repetitive prismatic structure having optical path changing slopes aligned in a substantially constant direction at an inclination angle in a range from 35 to 48 degrees with respect to a plane of the transparent film.

Abstract: In a liquid-crystal display device, an optical path control layer is provided at least on an outer side of the back side substrate, and has a plurality of optical path changing slopes inclined at an inclination angle of from 35 to 48 degrees with respect to a reference plane of the back side substrate. The optical path control layer has a refractive index higher than that of a low-refractive-index transparent layer provided in the back side substrate. Another low-refractive-index transparent layer lower in refractive index than the transparent substrate may be provided in a visual side substrate. Light sources may be disposed on at least two side surfaces of the liquid-crystal display panel. Light sources may be disposed on side surfaces of the back side substrate and the visual side substrate and at least on side surfaces of the liquid-crystal display panel which are different from each other. Another optical path control layer may be provided also on an outer side of the visual side substrate.

Abstract: A reflection type liquid-crystal display apparatus has a light source; and a liquid-crystal display device including a lower substrate provided with a reflection plate, an upper substrate provided with a transparent film on which a light reflection element is provided for reflecting transmitted light toward the lower substrate side, and liquid crystal held between the lower substrate and the upper substrate, the light source being disposed at an end surface of the upper substrate, the liquid-crystal display device being configured so that light incident onto a surface of the upper substrate opposite to a contact surface of the upper substrate with the liquid crystal is reflected by the reflection plate of the lower substrate so as to exit from the surface of the upper substrate opposite to the contact surface of the upper substrate with the liquid crystal, wherein at least one of end surfaces except the end surface on which the light source is disposed is coated with a reflection layer.

Abstract: An optical film has a transparent film, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.1 or less from that of a layer of the one surface of the transparent film, and a repetitive prismatic structure provided on the other surface of the transparent film, the repetitive prismatic structure having optical path changing slopes aligned in a substantially constant direction at an inclination angle in a range of from 35 to 48 degrees with respect to a plane of the transparent film. Another optical film has a transparent film having an average in-plane retardation of not larger than 30 nm, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.12 or less from that of a layer of the one surface of the transparent film, and the repetitive prismatic structure provided on the other surface of the transparent film.

Abstract: An optical path changing polarizer has a polarizer including a polarizing element and a transparent protective layer disposed on at least one side of the polarizing element, an adhesive layer disposed on one side surface of the polarizer, and a repetitive prismatic structure disposed on the other side of the polarizer. The repetitive prismatic structure includes optical path changing slopes aligned in a substantially constant direction so as to be inclined at an inclination angle of from 35 to 48 degrees with respect to a plane of the polarizer. Each of respective refractive indexes of the adhesive layer and a material for forming the optical path changing slopes is not lower than a refractive index of the polarizing element or the transparent protective layer. The adhesive layer has a refractive index different by 0.1 or less from a refractive index of a surface layer of the one side of the polarizer.

Abstract: A light pipe having a plate-like substance having an upper surface, a lower surface opposite to the upper surface, an incidence side surface, and an end surface opposite to the incidence side surface, the plate-like substance including a light output device formed in the upper surface so that light incident on the incidence side surface is made to exit from the lower surface through the light output device, the light output device being constituted by fine grooves arranged discontinuously so as to face the incidence side surface, each of the fine grooves having a length of not larger than 250 &mgr;m and a depth of not larger than 50 &mgr;m and not larger than ⅕ as large as the length, each of the fine grooves being constituted by a combination of an optical path changing slope inclined to the lower surface at an angle in a range of from 35 to 48 degrees and a steep slope facing the optical path changing slope and inclined to the lower surface at an angle of not lower than 60 degrees.

Abstract: A liquid-crystal display apparatus having a liquid-crystal panel, the liquid-crystal panel including a lower transparent substrate having a transparent electrode on at least one of its opposite surfaces, an upper transparent substrate having a transparent electrode opposite to the transparent electrode of the lower substrate, and liquid crystal held between the lower substrate and the upper substrate, wherein the upper substrate is thicker than the lower substrate. Preferably, the thickness of the lower substrate is not larger than ⅔ as large as the thickness of the upper substrate in order to achieve reduction in thickness and weight more effectively.

Abstract: An optical sheet has a transparent base material; a fine lens array constituted by a plurality of fine unit lenses formed on a front surface of the transparent base material; a diffusing layer formed on a rear surface of the transparent base material opposite to the surface on which the fine lens array is formed; and a light absorbing layer formed on the diffusing layer and including fine opening portions substantially located at focal points of the unit lenses; wherein: the diffusing layer is made of a transparent medium containing transparent fine particles different in refractive index from the transparent medium; and the transparent fine particles have a mean particle size in a particle size range for maximizing a value of Q/R at each of wavelengths in a visible region when Q is a scattering sectional area per transparent fine particle, and R is a radius of each of the transparent fine particles.

Abstract: There is provided a liquid-crystal display device having a transmission type liquid-crystal display panel including a liquid-crystal cell, a light source disposed on at least one side surface of the liquid-crystal display panel, and an optical path changing sheet disposed on a back side opposite to a visual side of the liquid-crystal display panel and having optical path changing slopes. Incident light from the light source is reflected toward the visual side of the liquid-crystal display device.

Abstract: A reflection-transmission double type liquid-crystal display device has a transmission type liquid-crystal display panel including a liquid-crystal cell, at least one illuminator disposed on at least one side surface of the liquid-crystal display panel, an optical path changing sheet which has a refractive index exhibiting a refractive index difference of not higher than 0.15 from a refractive index of a nearest liquid-crystal cell substrate and is bonded onto a back side of the liquid-crystal display panel through an adhesive layer having a refractive index exhibiting a refractive index difference of not higher than 0.20 from the refractive index of the nearest liquid-crystal cell substrate, and a reflection layer disposed on a back side of the optical path changing sheet. The optical path changing sheet includes optical path changing slopes and flat surfaces.

Abstract: An optical film has a transparent film, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.1 or less from that of a layer of the one surface of the transparent film, and a repetitive prismatic structure provided on the other surface of the transparent film, the repetitive prismatic structure having optical path changing slopes aligned in a substantially constant direction at an inclination angle in a range of from 35 to 48 degrees with respect to a plane of the transparent film. Another optical film has a transparent film having an average in-plane retardation of not larger than 30 nm, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.12 or less from that of a layer of the one surface of the transparent film, and the repetitive prismatic structure provided on the other surface of the transparent film.

Abstract: An optical film has a transparent film, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.1 or less from that of a layer of the one surface of the transparent film, and a repetitive prismatic structure provided on the other surface of the transparent film, the repetitive prismatic structure having optical path changing slopes aligned in a substantially constant direction at an inclination angle in a range of from 35 to 48 degrees with respect to a plane of the transparent film. Another optical film has a transparent film having an average in-plane retardation of not larger than 30 nm, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.12 or less from that of a layer of the one surface of the transparent film, and the repetitive prismatic structure provided on the other surface of the transparent film.

Abstract: An optical film including a transparent film having a hard coating layer provided on one side thereof, the hard coating layer including a repetitive prismatic structure having formed therein optical-path changing slopes oriented substantially toward certain directions at an angle of 35 to 48 degrees relative to the transparent film, and an adhesive layer laid on the other surface of the transparent film.

Abstract: An optical film has a transparent film, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.1 or less from that of a layer of the one surface of the transparent film, and a repetitive prismatic structure provided on the other surface of the transparent film, the repetitive prismatic structure having optical path changing slopes aligned in a substantially constant direction at an inclination angle in a range of from 35 to 48 degrees with respect to a plane of the transparent film. Another optical film has a transparent film having an average in-plane retardation of not larger than 30 nm, an adhesive layer provided on one surface of the transparent film, the adhesive layer having a refractive index different by 0.12 or less from that of a layer of the one surface of the transparent film, and the repetitive prismatic structure provided on the other surface of the transparent film.

Abstract: A light pipe includes a plate-like member having light output means formed in its upper surface so that light incident on an incidence side surface of the plate-like member is exited from the lower surface of the plate-like member through the light output means, an adhesive layer having a refractive index lower than that of the plate-like member, and (i) an anti-reflection layer made of a circularly polarizer and bonded to a lower surface of the plate-like member through the adhesive layer or (ii) a light-diffusing layer having a surface of fine prismatic structures and bonded to a lower surface of the plate-like member through the adhesive layer. A plane light source unit includes at least one light source disposed on one side surface of the light pipe. A reflection type liquid-crystal display device includes the plane light source unit and a liquid-crystal cell including a reflection layer disposed on the light output side of the plane light source unit.

Abstract: A liquid crystal display device having a light guide plate and a light source disposed on one of side surfaces of the light guide plate so that external light is transmitted through the light guide plate and enters a liquid-crystal display portion. A plurality of dots each constituted by a small recess or protrusion portion reflecting light from the light source toward the liquid crystal display portion are formed in or on another surface of the light guide plate opposite to the liquid crystal display portion. Each of the dots have a substantially V-shape in section with an inclination angle of the section being in a range of 35° to 43°.

Abstract: A method for manufacturing a light guide plate having dots on one surface thereof includes forming an oxide film on a crystal plane of a silicon substrate, forming a resist film on the oxide film, and forming a dot pattern in the oxide film by using the resist film as a mask, anisotropically etching the silicon substrate by using the oxide film as a mask, forming a metal film on the silicon substrate, stripping the metal film off so as to produce a stamper or a replica thereof, and transferring the dots onto a surface of a film or a plastic sheet or plate by using the stamper or the replica.

Abstract: To provide a reflection type liquid-crystal display device having an illuminator in front of the liquid-crystal display device, the illuminator having a light guide plate superior in light utilization efficiency, dots constituted by a plurality of small recess or protrusion portions for reflecting the light incident on the light guide plate toward the liquid-crystal display device are formed in or on a surface of the light guide plate which does not face the liquid-crystal display device. Each of the dots is set to have a substantially V-shape in section, the sectional inclination angle of the V-shape is set in a range of from 35 to 43°, and the sectional vertex angle of the V-shape is in a range of 70.6±2.5°.

Abstract: An optical film constituted by: a transparent film including a repetitive structure of a plurality of light exit means arranged at intervals of a regular pitch or intervals of irregular pitches in one of opposite surfaces of the transparent film, the repetitive structure of the plurality of light exit means having optical path changing slopes each inclined to the film surface at an inclination angle in a range of from 30 to 48 degrees in order to change an optical path of light from a direction of the film surface into a direction of thickness of the film; and an anti-reflection layer disposed on the film surface in which the plurality of light exit means are formed; wherein the optical film is light-transmissible in the direction of the thickness of the film.