Abstract: A light guide plate has a main-side microprism array sheet (main-side MPA sheet) 3 adhered to the top face 2a thereof, and a sub-side microprism array sheet (sub-side MPA sheet) 4 adhered to the bottom face 2b thereof. A prism formation region of the sub-side MPA sheet 4 is smaller than that of the main-side MPA sheet 3. Prisms in the prism formation region of the main-side MPA sheet 3 are, in an arrangement where the density of prisms arranged increases with distance from a light source 5, so arranged that the density of prisms arranged increases in a region that faces the prism formation region of the sub-side MPA sheet 4.

Abstract: A small-size and light-weight backlight system and a planar display device has a structure such that luminance unevenness and chromaticity unevenness in the vicinity of the incident light portion of a light guide plate are not noticeable. The back light system includes a light guide plate arranged to guide the light from a light source and emit the light in a planar direction. The light source includes a linear light source body arranged in the vicinity of the side edge of the light guide plate. The linear light source body includes a linear body in which a plurality of light emitting elements are embedded in the longitudinal direction. A light direction change sheet is arranged on the light emission surface of the light guide plate. The light direction change sheet has a plurality of protruding stripes arranged substantially parallel to the longitudinal direction of the linear light source body formed on the surface opposing to the light guide plate.

Abstract: A fluorescent lamp and a color liquid crystal display device, into which the fluorescent lamp is incorporated, use three-wavelength light emitting phosphers not to cause any interference fringe so as to eliminate color shadings from the display screen of said device. A phospher film consisting of a combination of the phosphers having their peak light emitting wavelengths at red, green and blue three-wavelength areas or ranges is formed on inner faces of a bulb of said fluorescent lamp, a half value width at the peak light emitting wavelength of each phospher i set to be in a range of 30 nm-100 nm, and a phospher defined by a general formula M.sub.3 (PO.sub.4).sub.2 :Sn, Mn (wherein M is at least one of Sr, Mg, Ba, Ca, Zn and Ga) is used as the red light emitting one. Fringes caused by the interference of light penetrating each optical component of the color liquid crystal display device with light reflected by front or boundary faces of these optical components can be thus prevented.

Abstract: In an lighting device, light rays, which have been illuminated from a discharge tube onto a light-guiding body and have been released from a light-emitting surface of the light-guiding body, are converged toward the normal direction by prisms each of which has a triangle- column shape and is installed on a light-converging control plate. A visual-range control plate provides a transparent visual range with a predetermined viewing angle with respect to the normal direction, while providing an opaque visual range outside the predetermined viewing angle with respect to the normal direction. This arrangement makes it possible to improve the surface luminance of the lighting device and prevent the degradation of the display quality. Thus, it is possible to achieve high-luminance, high quality lighting devices.

Abstract: The lighting apparatus including a cathode tube, a photoconductive member to which light from the cathode tube is conducted through an edge surface thereof, and reflecting means for reflecting the light from the cathode tube toward the edge surface of the photoconductive member. The reflecting means has on the inner surface thereof reflecting mirrors which are made of silver and arranged at uniform intervals. With this structure, even when the reflecting means and the cathode tube are disposed close to each other, it is possible to prevent a leakage current from flowing from the cathode tube to the reflecting mirrors because the reflecting surfaces are separated from each other. This stops the leakage current from lowering a driving current of the cathode tube, and it is therefore possible to maintain high light emitting efficiency in the cathode tube. Moreover, since silver is used for the reflecting surfaces, reflecting efficiency of the reflecting means is maintained.

Abstract: An improved flat display apparatus such as a liquid crystal display apparatus is disclosed. The apparatus is constructed so that when video signals from a VTR is reproduced to be displayed, the switching noise portion included in the video signals is changed to black level before being displayed, the section within the picture image area in which the switching noise originally appeared is masked by black level, making it possible to conceal the disorder in the picture image. In the case where television video signals are to be displayed, the picture can be enjoyed on a wide picture image area because the mask of black level is not generated.