Abstract: A light guide plate includes a light exit plane and a light entrance end, is formed into a shape having a thickness in a direction orthogonal to the light exit plane, the thickness being gradually larger as being farther from the light entrance end, and contains scattering particles dispersed therein, and a light guide plate assembly includes the light guide plate and a prism sheet which includes a plurality of prisms arrayed in parallel with each other, and is arranged so that vertex angles of the prisms face the light exit plane. The scattering particles scatter light entering from the light entrance end and propagating in the light guide plate, which satisfy Expressions (1) and (2) below, and vertex angles of the prisms of the prism satisfy Expression (3) and (4) below. 1.1??NPLGKC?8.2??(1) 0.005?KC?0.

Abstract: The light guide plate includes a light exit plane, two light entrance planes, two symmetrical inclined rear planes increasingly distanced from the light exit plane from the two light entrance planes toward a center of the light exit plane, a curved portion joining the two inclined rear planes and scattering particles for scattering light travelling inside the light guide plate. The light guide plate satisfies given ranges set for a length between the two light entrance planes, a thickness of each of the two light entrance planes, a thickness at the center of the curved portion, a radius of curvature thereof, tapers of the inclined rear planes, and a particle diameter and a density of the scattering particles, and conditions that a light use efficiency be 55% or greater and that a middle-high ratio represented by the brightness distribution at the light exit plane be greater than 0% and not greater than 25%.

Abstract: A diffusion material includes a prescribed scattering S(?) of respective fine particles that are determined by Mie theory for all plural kinds of fine particles at a wavelength ? of an incident light. The diffusion material includes plural kinds of fine particles having different refractive indices, dispersed into a matrix. Each particle providing light intensity attenuating rate C(?) in the diffusion material, and chromaticity variations ?x and ?y of the incident light. The diffusion power of the diffusion material by using determined chromaticity variations ?x and ?y; the diffusion material that is evaluated by this evaluation method and can emit illumination light free from wavelength unevenness. The diffusion material includes a blending the fine particles to provide the prescribed diffusion and uniform illumination.

Abstract: The liquid crystal display device with a simple configuration is capable of emitting light with a desired color temperature, achieving high light use efficiency, and displaying high quality images. The liquid crystal display device includes a planar lighting device and a liquid crystal display panel. The planar lighting device includes a light source having LED chips for emitting blue light, a transparent light guide plate having a light entrance plane admitting light emitted by the light source and a light exit plane emitting planar light, and a fluorescent member disposed between the light emission plane and the light entrance plane and having one or more fluorescent substance coated areas for emitting white light by converting blue light from the light source into white light and one or more blue light passing areas passing blue light as blue light. The liquid crystal display panel essentially includes red, green and blue filters.

Abstract: The planar lighting device includes a light source having at least one LED chip for emitting blue light through a light emission face, a transparent light guide plate having at least one light entrance plane through which light emitted by the light source is admitted and a light exit plane through which the light admitted through the at least one light entrance plane is emitted as planar light, and a fluorescent member disposed between the light emission face and each of the at least one light entrance plane and having a fluorescent substance coated area for emitting white light by converting the blue light from the light source into the white light and blue light passing areas through which the blue light from the light source is allowed to pass as the blue light.

Abstract: A light guide plate includes a light exit plane and a light entrance end, is formed into a shape having a thickness in a direction orthogonal to the light exit plane, the thickness being gradually larger as being farther-from the light entrance end, and contains scattering particles dispersed therein, and a light guide plate assembly includes the light guide plate and a prism sheet which includes a plurality of prisms arrayed in parallel with each other, and is arranged so that vertex angles of the prisms face the light exit plane. The scattering particles scatter light entering from the light entrance end and propagating in the light guide plate, which satisfy Expressions (1) and (2) below, and vertex angles of the prisms of the prism satisfy Expression (3) and (4) below. 1.1??NPLGKC?8.2 ??(1) 0.005?KC?0.

Abstract: The method of evaluating a diffusion material that determines the total cross-sectional area of scattering Stotal (?) inside the diffusion material as a total of cross-sectional areas of scattering S (?) of respective fine particles that are determined by Mie theory for all of plural kinds of fine particles at a wavelength ? of a incident light to the diffusion material in which plural kinds of fine particles having different refractive indices are dispersed into a matrix, determines from this a light intensity attenuating rate C(?) in the diffusion material, determines chromaticity variations ?x and ?y of the incident light to and emitted light from the diffusion material using this, and evaluates a diffusion power of the diffusion material by using determined chromaticity variations ?x and ?y; the diffusion material that is evaluated by this evaluation method and can emit illumination light free from wavelength unevenness; the method of blending the fine particles into the diffusion material for obtaining s

Abstract: The light guide plate includes a light exit plane, two light entrance planes, two symmetrical inclined rear planes increasingly distanced from the light exit plane from the two light entrance planes toward a center of the light exit plane, a curved portion joining the two inclined rear planes and scattering particles for scattering light travelling inside the light guide plate. The light guide plate satisfies given ranges set for a length between the two light entrance planes, a thickness of each of the two light entrance planes, a thickness at the center of the curved portion, a radius of curvature thereof, tapers of the inclined rear planes, and a particle diameter and a density of the scattering particles, and conditions that a light use efficiency be 55% or greater and that a middle-high ratio represented by the brightness distribution at the light exit plane be greater than 0% and not greater than 25%.

Abstract: The liquid crystal display device with a simple configuration is capable of emitting light with a desired color temperature, achieving high light use efficiency, and displaying high quality images. The liquid crystal display device includes a planar lighting device and a liquid crystal display panel. The planar lighting device includes a light source having LED chips for emitting blue light, a transparent light guide plate having a light entrance plane admitting light emitted by the light source and a light exit plane emitting planar light, and a fluorescent member disposed between the light emission plane and the light entrance plane and having one or more fluorescent substance coated areas for emitting white light by converting blue light from the light source into white light and one or more blue light passing areas passing blue light as blue light. The liquid crystal display panel essentially includes red, green and blue filters.

Abstract: A parallel groove of a light guide place for accommodating a light source has, in a perpendicular cross section, a shape composed of a pair of contour lines that approach each other toward a light emitting plane, cross at a peak, and has a part where an inclination angle to a line vertical to the light emitting plane changes, and the inclination angle at a base end side far from the peak is sharper than that at a tip end side close to the peak. Thus, uniform and high brightness light can be emitted.

Abstract: The planar lighting device includes a light source having at least one LED chip for emitting blue light through a light emission face, a transparent light guide plate having at least one light entrance plane through which light emitted by the light source is admitted and a light exit plane through which the light admitted through the at least one light entrance plane is emitted as planar light, and a fluorescent member disposed between the light emission face and each of the at least one light entrance plane and having a fluorescent substance coated area for emitting white light by converting the blue light from the light source into the white light and blue light passing areas through which the blue light from the light source is allowed to pass as the blue light.