Abstract: A plate-shaped light guide for a planar light source device that guides a light emitted from a primary light source includes a light incident end face, a light emitting face and a back surface on the opposite to the light emitting face, wherein a plurality of first elongated lenses having an average slant angle of 0.5 to 60° are continuously or intermittently formed on one of the light emitting face and the back surface, and at least a portion of a surface of each first elongated lens, or at least a portion of the other one of the light emitting face and the back surface, or at least the portion of the surface of each first elongated lens and at least the portion of the other one of the light emitting face and the back surface includes a rough surface having an average slant angle of 0.1 to 8°.

Abstract: An area light source comprising an LED primary light source (2), a plate-like light guide (4) and a light deflector (6) is provided with a direct light incoming prevention means closed of a light-blocking member (9). The light guide (4) has a light incoming end face (41) and a light outgoing face (43) and guides a light emitted from the LED primary light source (2). The light deflector (6) is arranged adjacently to the light outgoing face (43) and has a light entering face (61) and a light exiting face (62). The direct light incoming prevention means prevents a light, which is emitted from the LED primary light source (2), from entering into the light deflector (6) without passing through the light guide (4). The light-blocking deflector (9) is disposed on a first region of the light outgoing face (43) which is located near the edge of the light incoming end face side of the light outgoing face (4).

Abstract: A plate-shaped light guide for a planar light source device that guides a light emitted from a primary light source includes a light incident end face, a light emitting face and a back surface on the opposite to the light emitting face, wherein a plurality of first elongated lenses having an average slant angle of 0.5 to 60° are continuously or intermittently formed on one of the light emitting face and the back surface, and at least a portion of a surface of each first elongated lens, or at least a portion of the other one of the light emitting face and the back surface, or at least the portion of the surface of each first elongated lens and at least the portion of the other one of the light emitting face and the back surface includes a rough surface having an average slant angle of 0.1 to 80°.

Abstract: A planar light source system having an LED (1) serving as a primary light source of substantially point-shaped light source, a light guide (2) having a light incident face on which light emitted from the LED (1) is incident and a light emission face (4) from which light guided through the light guide (2) is emitted, a light deflecting device (3) for controlling the direction of the emission light from the light guide (2), and a reflection sheet (6). LED (1) is disposed at a corner portion of the light guide (2), and many elongated prisms (5) are arranged substantially arcuately in parallel to each other on the light incident surface (14) of the light deflecting device (3) so as to surround LED (1).

Abstract: A light guide which guides light emitted from an LED includes a light incident end surface for receiving light, a light outputting surface for outputting a guided light, and a lens forming surface that has a plurality of elongated lenses arranged in parallel to each other and formed along the directivity of light incident from the LED, such that a plurality of micro regions are defined over the plurality of elongated lens. In the vicinity of the LED, a distribution of micro regions having an inclination angle between 20° and 50° is at least 10% over all micro regions. A light deflection element disposed adjacent to the light guide light outputting surface includes a light entrance surface having a plurality of lenses formed thereon that are parallel to each other and extend in a direction parallel to the light guide light incident end surface.

Abstract: A planar light source device includes a primary light source (1), a light guide (3) which leads the light emitted from the primary light source (1), and having a light incident face (31) to which the light emitted from the primary light source (1) comes in, and a light emitting face from which the led light goes out, a light deflection element (4) arranged adjacent to the light emitting face (33) of the light guide (3), and a polarization separation element (6) disposed on the side of a light outgoing surface (42) of the light deflection element (4), and having a function of transmitting one of polarization components of the incident light and reflecting the other of the polarization components. The full width at half maximum of the luminance distribution of the incident light upon the polarization separation element (6) in an XY plane parallel to the travel direction of the light in the light guide (3) is 25° or less. The reference symbol 7 indicates a liquid crystal display element.

Abstract: An area light source comprising an LED primary light source (2), a plate-like light guide (4) and a light deflector (6) is provided with a direct light incoming prevention means closed of a light-blocking member (9). The light guide (4) has a light incoming end face (41) and a light outgoing face (43) and guides a light emitted from the LED primary light source (2). The light deflector (6) is arranged adjacently to the light outgoing face (43) and has a light entering face (61) and a light exiting face (62). The direct light incoming prevention means prevents a light, which is emitted from the LED primary light source (2), from entering into the light deflector (6) without passing through the light guide (4). The light-blocking deflector (9) is disposed on a first region of the light outgoing face (43) which is located near the edge of the light incoming end face side of the light outgoing face (4).

Abstract: The index of refraction of a light guide (6) for transmitting light outputted from a primary light source (1) is ng, and the light guide (6) has a light input end face (9), a light output surface from which the transmitted light is outputted, and a back surface opposed to the light output surface. A leaky ray modulator (8) is provided to at least either the light output surface or the back surface. The leaky ray modulator (8) has a composite layer (50) provided on the light output surface or the back surface and composed of first refractive index regions (3) having a refractive index n1 (ng>n1) and second refractive index regions (4) having a refractive index n2 (n2>n1) and a third refractive index layer (5) provided on the composite layer (50) and having a refractive index n3 (n3>n1). A reflecting plate (7) is provided adjacent to the back surface of the light guide (6).

Abstract: A planar light source device includes a primary light source (1), a light guide (3) which leads the light emitted from the primary light source (1), and having a light incident face (31) to which the light emitted from the primary light source (1) comes in, and a light emitting face from which the led light goes out, a light deflection element (4) arranged adjacent to the light emitting face (33) of the light guide (3), and a polarization separation element (6) disposed on the side of a light outgoing surface (42) of the light deflection element (4), and having a function of transmitting one of polarization components of the incident light and reflecting the other of the polarization components. The full width at half maximum of the luminance distribution of the incident light Upon the polarization separation element (6) in an XY plane parallel to the travel direction of the light in the light guide (3) is 25° or less. The reference symbol 7 indicates a liquid crystal display element.

Abstract: A platy light guide (4) which guides light emitted from an LED (2) and has a light incident end surface (41) for receiving light from the LED (2) and a light outputting surface (43) for outputting a guided light, wherein a plurality of lens rows extending along the directivity direction (X direction) of a light guide incident light in a plane along the light outputting surface (43) and arranged in parallel to each other are formed on a rear surface (44). In the vicinity of the LED (2), the shape of the section perpendicular to their extending directions of the plurality of lens rows is such that the existence proportion of an angle component having an absolute value of at least 20° and up to 50° of an inclination angle formed by a tangent and a lens row forming surface in each fine area is at least 10%.

Abstract: An area light source comprises an LED (2), a plate-like light guide (4) adapted to guide the light emitted from the LED (2) and having a light incident end face (41) and a light emerging face (43), and a light deflecting element (6). Continuously arranged on the light emerging face (43) are lens arrays extending generally perpendicularly to the direction of the directivity of the light entering the light guide (4) from the LED (2) in a plane along the light emerging face (43) and having an average angle of inclination of 0.5° to 60°. On each surface of the lens arrays a coarse surface having an average angle of inclination of 0.1° to 8° is formed. Continuously arranged on the back (44) of the light guide are lens arrays extending generally parallel to the direction of the directivity of the light entering the light guide (4) from the LED (2) in the plane along the light emerging face (43) and having an average angle of inclination of 8° to 60°.

Abstract: The index of refraction of a light guide (6) for transmitting light outputted from a primary light source (1) is ng, and the light guide (6) has a light input end face (9), a light output surface from which the transmitted light is outputted, and a back surface opposed to the light output surface. A leaky ray modulator (8) is provided to at least either the light output surface or the back surface. The leaky ray modulator (8) has a composite layer (50) provided on the light output surface or the back surface and composed of first refractive index regions (3) having a refractive index n1 (ng>n1) and second refractive index regions (4) having a refractive index n2 (n2>n1) and a third refractive index layer (5) provided on the composite layer (50) and having a refractive index n3 (n3>n1). A reflecting plate (7) is provided adjacent to the back surface of the light guide (6).

Abstract: A planar light source system having an LED (1) serving as a primary light source of substantially point-shaped light source, a light guide (2) having a light incident face on which light emitted from the LED (1) is incident and a light emission face (4) from which light guided through the light guide (2) is emitted, a light deflecting device (3) for controlling the direction of the emission light from the light guide (2), and a reflection sheet (6). LED (1) is disposed at a corner portion of the light guide (2), and many elongated prisms (5) are arranged substantially arcuately in parallel to each other on the light incident surface (14) of the light deflecting device (3) so as to surround LED (1).

Abstract: A planar light source system having an LED (1) serving as a primary light source of substantially point-shaped light source, a light guide (2) having a light incident face on which light emitted from the LED (1) is incident and a light emission face (4) from which light guided through the light guide (2) is emitted, a light deflecting device (3) for controlling the direction of the emission light from the light guide (2), and a reflection sheet (6). LED (1) is disposed at a corner portion of the light guide (2), and many elongated prisms (5) are arranged substantially arcuately in parallel to each other on the light incident surface (14) of the light deflecting device (3) so as to surround LED (1).

Abstract: A planar light source device contains a light source (1); a light guide (2) which has a light incident face (21) on at least one side end surface thereof which confronts the light source (1), and a light emitting face (23) on one of two principal surfaces (23, 24) thereof; and a light direction varying sheet (4) which is disposed on the light emitting face (23) of the light guide (2), wherein a back surface (24) of the light guide (2) opposing to the light emitting face (21) is formed as a prism surface which comprises a plurality of elongated prisms each having substantially triangular cross section of a vertical angle within a range of 60 to 80° or 125 to 150° so as to extend in parallel to each other and in perpendicular to the light incident face (21), and a major part of the light emitting face (23) is formed as an uneven surface having an average slant angle of 0.3 to 30°.

Abstract: A planar light source device contains a light source (1); a light guide (2) which has a light incident face (21) on at least one side end surface thereof which confronts the light source (1), and a light emitting face (23) on one of two principal surfaces (23, 24) thereof; and a light direction varying sheet (4) which is disposed on the light emitting face (23) of the light guide (2), wherein a back surface (24) of the light guide (2) opposing to the light emitting face (21) is formed as a prism surface which comprises a plurality of elongated prisms each having substantially triangular cross section of a vertical angle within a range of 60 to 80° or 125 to 150° so as to extend in parallel to each other and in perpendicular to the light incident face (21), and a major part of the light emtting face (23) is formed as an uneven surface having an average slant angle of 0.3 to 30°.

Abstract: A planar light source system having an LED (1) serving as a primary light source of substantially point-shaped light source, a light guide (2) having a light incident face on which light emitted from the LED (1) is incident and a light emission face (4) from which light guided through the light guide (2) is emitted, a light deflecting device (3) for controlling the direction of the emission light from the light guide (2), and a reflection sheet (6). LED (1) is disposed at a corner portion of the light guide (2), and many elongated prisms (5) are arranged substantially arcuately in parallel to each other on the light incident surface (14) of the light deflecting device (3) so as to surround LED (1).

Abstract: A surface light source device, comprising a light source (2); a light conductor (1) which has a light incident face (11) on at least one side end surface thereof which confronts the light source (2), and a light emitting face (12) on one surface thereof which is substantially perpendicular to the light incident face (11); and a light angle varying sheet (3) which is disposed at a side of the light emitting face (12) of the light conductor (1), wherein at least one of the light emitting face (12) and a back surface (13) of the light conductor (1) comprises a minute structure having an average slant angle of 0.5 to 7.5 degrees. The light angle varying sheet (3) may comprise a prism sheet having a plurality of prisms (31) which are formed parallel to one another on at least one surface thereof.

Abstract: A resin sheet having laminated transparent resin layers and a smooth outer surface, the refractive indexes of two resins of any adjacent two resin layers differing from each other, the interfaces among the resin layers having an uneven shape, is produced with an extrusion molding apparatus having such a structure that a plurality of transparent resins are extruded from respective separate flow passages into a composite resin flow passage to form a composite resin flow having a laminate structure with an uneven shape at the interfaces of the resin layers, and that the composite resin flow is extruded from an outlet of the composite resin flow passage. The resin sheet is used as a laminate, or a light guide of a surface light source element.

Abstract: A surface light source device, comprising a light source (2); a light conductor (1) which has a light incident face (11) on at least one side end surface thereof which confronts the light source (2), and a light emitting face (12) on one surface thereof which is substantially perpendicular to the light incident face (11); and a light angle varying sheet (3) which is disposed at a side of the light emitting face (12) of the light conductor (1). wherein at least one of the light emitting face (12) and a back surface (13) of the light conductor (1) comprises a minute structure having an average slant angle of 0.5 to 7.5 degrees. The light angle varying sheet (3) may comprise a prism sheet having a plurality of prisms (31) which are formed parallel to one another on at least one surface thereof.