Abstract: A light guide plate has an emission face provided with a plurality of projection rows. Each projection row consists of a pair of slopes, a first slope (a slope far from an incidence end face) and a second slope (another slope near to the incidence end face). An inclination angle of the first slope with respect to an imaginary plane perpendicular to a frontal direction decreases gradually in first region on the emission face (or back face) according to an increasing distance from the incidence end face, then increasing gradually in second region according to an increasing distance from the incidence end face. The inclination angle at an incidence-end-face-side end of first region is greater that at a distal-end-face-side end of second region. Variation of the inclination angle in the first region is greater that in the second region.

Abstract: A fluorescent lamp 6 emits illumination light (primary light), which is deflected by means of a light guide plate 4 to be converted into a light flux having an enlarged cross section. A liquid crystal display panel 3 is supplied with the light flux via a prism sheet (light control sheet) 12. The prism sheet 12 or an alternative light control sheet to be employed is capable of rotating polarization involved by the light toward a direction of light transmission axis of a polarization plate 14. An effective light input to the liquid crystal display panel 3 is achieved by light transmission through the polarization plate 14 at a high transmission rate. The liquid crystal display panel 3 controls polarization state of the inputted light and, according to the state, causes the light to pass through another polarization plate (analyser) 15. Emission occurs, under intensity control depending on positions, via the polarization plate (analyzer) 15, to provide an image.

Abstract: A light guide plate has an incidence face provided by a side end face, emission face and back face. The incidence face has first and second end edges meeting the emission face and the back face respectively. First range N1 in the emission face is set as to correspond to a reflecting-cover which returns at least a part of light emitted from first range N1 into the light guide plate. The reflecting-cover is disposed along the first end edge, covering a part of the emission face. Most of the returned light is emitted from second range N2, becoming illumination light. First range N1 has emission function weaker than that of second range N2, thereby avoiding the emission from showing abnormal emission in the vicinity of the first end edge. The reflecting-cover may be provided by an end edge portion of a lamp reflector for a primary light source.

Abstract: Provided are a light guide plate realizing a high and uniformalized illumination brightness without reducing emission directivity, a surface light source device and an image display which employ the light guide plate. The light guide plate has an emission face provided with a great number of projection rows. Each projection row consists of a pair of slopes, a first slope (a slope far from an incidence end face) and a second slope (another slope near to the incidence end face). Angle ?a is defined as an inclination angle of the first slope with respect to an imaginary plane perpendicular to a frontal direction.

Abstract: White points (point-like abnormal emission) are made scare even if prismatic projection rows of a prism sheet are pressed against an emission face of a light guide plate. A plurality of prismatic projections are formed side by side on an inner face of a prism sheet. Each prismatic projection row has a steep slope for light input and a gentle slope for inner-reflection, the gentle slope being provided with a plurality of fine projections in a predetermined range near to the tip of the prismatic projection row. Fine projections may be ridge-like or dome-like projections. The tips of prismatic projection rows may be diverge to form a plurality of top portions having cross sections like triangles.

Abstract: A fluorescent lamp 6 emits illumination light (primary light), which is deflected by means of a light guide plate 4 to be converted into a light flux having an enlarged cross section. A liquid crystal display panel 3 is supplied with the light flux via a prism sheet (light control sheet) 12. The prism sheet 12 or an alternative light control sheet to be employed is capable of rotating polarization involved by the light toward a direction of light transmission axis of a polarization plate 14. An effective light input to the liquid crystal display panel 3 is achieved by light transmission through the polarization plate 14 at a high transmission rate. The liquid crystal display panel 3 controls polarization state of the inputted light and, according to the state, causes the light to pass through another polarization plate (analyser) 15. Emission occurs, under intensity control depending on positions, via the polarization plate (analyzer) 15, to provide an image.

Abstract: A liquid crystal display includes a LCD panel and a surface light source device of side light type to illuminate the panel. The surface light source device comprises a guide plate having an emission face, a back face and an incidence face, a primary light source to supply light through the incidence face, and a reflection member disposed along the back face. The reflection member has an inner reflection face including a plurality of fine regions to control angular extension of illumination output. The fine regions are provided with scattering property which is different from that of the rest region. In cases where emission promoting power (scattering power) of the emission face falls according to distance from the incidence face, the reflection face of the reflection member is provided with scattering power which varies so as to tend to compensate said falling of emission promoting power. Fine regions are arranged in corner portions located at both ends of the incidence face to avoid short of emission.