Abstract: The present invention relates to an optical modulating display device (200) such as a liquid crystal displaying device provided with a front-light type planar illuminating device. The above front-light type planar illuminating device allows illuminating light to propagate inside a substrate (1), and is provided with a low refraction layer (3) being lower in refractive index than the substrate (1) and being in close contact with the inner surface of the substrate (1), and with reflection structure (11) on the outer surface of the substrate (1). The optical modulating display device (200) provided with the above front-light type planar illuminating device can ensure a sufficient amount of guide light propagating inside the substrate (1) and reduce non-uniformity in display illumination. And a display apparatus mounting the above optical modulating display device (200) thereon can be reduced in thickness and weight and provide a high quality display.

Abstract: A light source apparatus permits an angular range of illumination light to be changed, wherein the apparatus can be made thin. A related display apparatus permits a visible angular range to be changed using the light source apparatus. The display apparatus can be mounted in a terminal device, and an optical member and an optical unit can be incorporated in the light source apparatus. The light source apparatus is provided with a light guide plate with a conical sheet. Two light sources are provided on side surfaces of the light guide plate. Two inclined surfaces whose inclination angles to a light output surface differ from each other are formed at a light diffusion surface of the light guide plate. The conical sheet is provided with a flat plate portion on which a plurality of cones are formed. The cones protrude toward the light guide plate.

Abstract: A light source device which is uniform in the intensity of distribution of an emitted light and high in the optical utilization efficiency, a display device which is high in recognability and is energy-saving, and an information terminal are provided. A reflecting portion is formed on a surface opposed to an emitting surface of a linear light guide. The reflecting portion is periodically formed with a total reflecting surface guiding a light incident on a linear light guide from a point light source, a light extracting surface allowing the light to reflect in such a way as to emit the light guiding the linear light guide from the emitting surface, and a re-incidence plane which takes the light transmitted but not reflected on the light extracting surface into the linear light guide again. By changing the size of the light extracting surface and the re-incidence plane, the intensity of distribution of the emitting light from the linear light guide can be made uniform.

Abstract: A light source apparatus permits an angular range of illumination light to be changed and can be made thin. A related display apparatus permits a visible angular range to be changed using the light source apparatus. The display apparatus can be mounted in a terminal device, and an optical member and an optical unit can be incorporated in the light source apparatus. The light source apparatus is provided with a light guide plate with a conical sheet provided in front. Two light sources are provided on side surfaces of the light guide plate. Two inclined surfaces whose inclination angles to a light output surface differ from each other are formed at a light diffusion surface of the light guide plate. The conical sheet is provided with a flat plate portion on the back side of which a plurality of cones are formed. The cones protrude toward the light guide plate.

Abstract: The present invention relates to an optical modulating display device (200) such as a liquid crystal displaying device provided with a front-light type planar illuminating device. The above front-light type planar illuminating device allows illuminating light to propagate inside a substrate (1), and is provided with a low refraction layer (3) being lower in refractive index than the substrate (1) and being in close contact with the inner surface of the substrate (1), and with reflection structure (11) on the outer surface of the substrate (1). The optical modulating display device (200) provided with the above front-light type planar illuminating device can ensure a sufficient amount of guide light propagating inside the substrate (1) and reduce non-uniformity in display illumination. And a display apparatus mounting the above optical modulating display device (200) thereon can be reduced in thickness and weight and provide a high quality display.

Abstract: A small light source unit of simple structure that emits light forward with high efficiency is well-suited as a backlight in a liquid crystal display device. The light director in this unit has reflective internal faces adjacent opposite peripheral regions of the entrance face and two refractive index interfaces in it. The reflective internal faces and the refractive index interfaces are oriented on inclined planes. The refractive index of a middle region between the two interfaces is the smallest among those of the three regions making up the light director.

Abstract: A light source device which is uniform in the intensity of distribution of an emitted light and high in the optical utilization efficiency, a display device which is high in recognability and is energy-saving, and an information terminal are provided. A reflecting portion is formed on a surface opposed to an emitting surface of a linear light guide. The reflecting portion is periodically formed with a total reflecting surface guiding a light incident on a linear light guide from a point light source, a light extracting surface allowing the light to reflect in such a way as to emit the light guiding the linear light guide from the emitting surface, and a re-incidence plane which takes the light transmitted but not reflected on the light extracting surface into the linear light guide again. By changing the size of the light extracting surface and the re-incidence plane, the intensity of distribution of the emitting light from the linear light guide can be made uniform.

Abstract: A small light source unit of simple structure that emits light forward with high efficiency is well-suited as a backlight in a liquid crystal display device. The light director in this unit has reflective internal faces adjacent opposite peripheral regions of the entrance face and two refractive index interfaces in it. The reflective internal faces and the refractive index interfaces are oriented on inclined planes. The refractive index of a middle region between the two interfaces is the smallest among those of the three regions making up the light director.