Abstract: A diffused light controlling optical sheet to be used in a back light device of a liquid crystal display apparatus, wherein convex parts are provided at the opposite side to its light receiving surface and a tangential line on a side face of the convex part makes an angle of 60 to 90 degrees with the light receiving surface, and a fine material which is slightly different in refractive index from a material forming the sheet is contained inside the convex parts and thereby a diffused light inputted through the light receiving surface is converted to a diffused light of intense directivity.

Abstract: In an optical sheet 10 having a prism surface 16 formed by providing unit prisms 14 on the upper surface of a transparent base material 12, a coating layer 18 is provided on the reverse surface of the transparent base material opposite to the prism surface 16, spherical beads 20 are arranged projecting from the surface of the coating layer 18 by 1 to 10 &mgr;m in height, and the coating layer 18 is brought into contact with the flat and smooth surface 22A of the light-transmissive material 22 through the spherical beads 20 which are put between them. The spherical beads are 1 &mgr;m or less in half bandwidth of the distribution of particle diameters and are made uniform in height projecting from the coating layer 18.

Abstract: In a polarization splitting sheet (10) made of a transparent base material sheet (12), a coating layer (14) is provided on the rear surface of the base material sheet(12), this coating layer (14) having spherical beads (16) of a diameter in the range from 1 to 10 &mgr;m protruding from its surface, the spherical beads (16) of the coating layer (14) making contact with a smooth surface (18A) of a light-transmitting material (18). The half-value width of the diameter of the spherical beads (16) is made no greater than 1 &mgr;m, and the protrusion height of the spherical beads (16) from the coating layer (14) is made uniform.

Abstract: A polarization light splitting film having a light receiving side and a light transmitting side. The polarization light splitting film includes an optical rotation selection layer at the light receiving side for reflecting one of right and left circularly polarized components of a light beam that is incident on the light receiving side and for transmitting the other one of the right and left circular polarization components of the light beam, and a quarter-wave layer laminated over the optical rotation selection layer at the light transmitting side.

Abstract: A back light device 10 comprises a light source 12, a lightconductor 14 for outputting light from the light source from its outputting surface 14B, a light diffusing sheet 16 for receiving diffused light from the lightconductor 14 and shifting the maximum intensity direction to the direction of the normal standing on the light outputting face 16B, a polarized beam splitting sheet 18 through which one polarized light component among the light from the light diffusing sheet 16 is transmitted and on which the other polarized light component is reflected.

Abstract: In an optical sheet 10 having a prism surface 16 formed by providing unit prisms 14 on the upper surface of a transparent base material 12, a coating layer 18 is provided on the reverse surface of the transparent base material opposite to the prism surface 16, spherical beads 20 are arranged projecting from the surface of the coating layer 18 by 1 to 10 &mgr;m in height, and the coating layer 18 is brought into contact with the flat and smooth surface 22A of the light-transmissive material 22 through the spherical beads 20 which are put between them. The spherical beads are 1 &mgr;m or less in half bandwidth of the distribution of particle diameters and are made uniform in height projecting from the coating layer 18.

Abstract: A diffused light controlling optical sheet to be used in a back light device of a liquid crystal display apparatus, wherein convex parts are provided at the opposite side to its light receiving surface and a tangential line on a side face of the convex part makes an angle of 60 to 90 degrees with the light receiving surface, and a fine material which is slightly different in refractive index from a material forming the sheet is contained inside the convex parts and thereby a diffused light inputted through the light receiving surface is converted to a diffused light of intense directivity.

Abstract: In a backlight device 10 comprising a light guide 12, a light source 14, a prism sheet 16, a polarized beam splitter sheet 18, and a light reflection sheet 20, the light reflection sheet 20 is composed with the provision of a regular reflection plane 20A in a shape of flat surface, and the direction of the normal standing on the regular reflection plane 20A is substantially the same as the directions of the normals standing respectively on the above-mentioned prism sheet 16 and on the polarized beam splitter sheet 18.

Abstract: In a combination reflective/transmissive liquid-crystal display device, when the liquid-crystal display device is in the transmissive mode, unpolarized light from a light source passes through a circular polarization separating layer, a half-wavelength layer in the off condition, and a first bidirectional dichroic circular polarizing layer and then strikes a liquid-crystal cell, the retardation value of which, as a result of an electrical field applied thereto, changes so as to shift light 0 to .pi., thereby modulating incident circularly polarized light, which is caused to strike a second bidirectional dichroic circular polarizing layer, the transmitted component in which serves as the display light.

Abstract: In an optical sheet 10 having a prism surface 16 formed by providing unit prisms 14 on the upper surface of a transparent base material 12, a coating layer 18 is provided on the reverse surface of the transparent base material opposite to the prism surface 16, spherical beads 20 are arranged projecting from the surface of the coating layer 18 by 1 to 10 .mu.m in height, and the coating layer 18 is brought into contact with the flat and smooth surface 22A of the light-transmissive material 22 through the spherical beads 20 which are put between them. The spherical beads are 1 .mu.m or less in half bandwidth of the distribution of particle diameters and are made uniform in height projecting from the coating layer 18.

Abstract: A back light device 10 comprises a light source 12, a lightconductor 14 for outputting light from the light source from its outputting surface 14B, a light diffusing sheet 16 for receiving diffused light from the lightconductor 14 and shifting the maximum intensity direction to the direction of the normal standing on the light outputting face 16B, a polarized beam splitting sheet 18 through which one polarized light component among the light from the light diffusing sheet 16 is transmitted and on which the other polarized light component is reflected.

Abstract: In an optical sheet 10 having a prism surface 16 formed by providing unit prisms 14 on the upper surface of a transparent base material 12, a coating layer 18 is provided on the reverse surface of the transparent base material opposite to the prism surface 16, spherical beads 20 are arranged projecting from the surface of the coating layer 18 by 1 to 10 .mu.m in height, and the coating layer 18 is brought into contact with the flat and smooth surface 22A of the light-transmissive material 22 through the spherical beads 20 which are put between them. The spherical beads are 1 .mu.m or less in half bandwidth of the distribution of particle diameters and are made uniform in height projecting from the coating layer 18.

Abstract: A linear light source is disposed adjacent to the side face of a transparent light conducting plate. The thickness of the light conducting plate decreases as the position goes away from the light source. Light diffusing elements are formed on the major surface of the light conducting plate opposite to its light exit surface. At least one transparent sheet has, on the same surface thereof, a number of prisms having straight ridges that are arranged substantially parallel with each other at small intervals. The transparent sheet is disposed on the side of the light exit surface of the light conducting plate so that extensions of the straight ridges intersect the light source substantially perpendicularly.

Abstract: In a backlighting device for use with display panels that comprises a light conducting plate made of a light-transmissive material, one of the major faces of said light conducting plate being provided with a light diffusing capability and covered with a specular or light diffusing/reflecting plate, and a linear light source provided in proximity to the end portion of at least one side of said light conducting plate, the improvement wherein at least one sheet that is made of a light-transmissive material and that has a multiple of raised structures having straight ridgelines at minute intervals on the same side in such a manner that the ridgelines are substantially parallel to one another or at least one sheet that is made of a light-transmissive material and that has a multiple of pyramidal or conical projecting structures at minute intervals on the same side, said projecting structures having portions of such a shape that the vertical angles are substantially the same, is provided on the exit face of the lig

Abstract: A light reflector covers a linear light source that is disposed adjacent to a light incident end face of a light conducting plate. The interval between the end portions of the light reflector adjacent to the light incident end face of the light conducting plate is made smaller than the thickness of the light incident end face. Alternatively, the light-exit-side portion of the light reflector located between the linear light source and the light incident end face of the light conducting plate is disposed within the thickness of the light incident end face.

Abstract: In a back lighting device for a side light type panel, one end portion of a specular or light diffusing/reflecting film covering a linear light source is bonded to one end portion of a light conducting plate which is on the side of its light emerging surface and is in proximity of the linear light source, and a light diffusing/reflecting film is laid through an air layer on the part of the rear surface of the light conducting plate which corresponds to the junction. The back lighting device of the invention is small in size, large in effective light emitting area when compared with its external dimensions, and excellent in the distribution of luminance. Hence, it can be used as a back light device that is highly efficient in converting power to luminance.

Abstract: At least part of a reflector surface covering a rod-shaped light source is a continuous body having such a shape that in a plane perpendicular to the central axis of the rod-shaped light source, a ray emitted from a light emitting point on the surface of the rod-shaped light source in the tangential direction going away from a light conducting plate is reflected back to the vicinity of the light emitting point. According to another aspect, at least part of a reflector surface covering a rod-shaped light source located between the rod-shaped light source and the light conducting plate is part of a parabola whose focus is substantially located on the side face of the light conducting plate in a plane perpendicular to the central axis of the rod-shaped light source.

Abstract: A backlighting device for use with display panels has a plurality of light diffusing elements formed in dots or stripes on one of the two major faces of a light conducting plate that is made of a light-transmissive material. The device also has a linear light source provided in proximity to the end portion of at least one side of the light conducting plate. In the device, at least one sheet that is made of a light-transmissive material and which has a multiple of prisms or raised structures having straight ridgelines defined by the apices and minima of the raised structures at small intervals on the same side of the sheet.

Abstract: In a backlighting device for use with display panels that comprises a light conducting plate made of a light-transmissive material, one of the major faces of said light conducting plate being provided with a light diffusing capability and covered with a specular or light diffusing/reflecting plate, and a linear light source provided in proximity to the end portion of at least one side of said light conducting plate, the improvement wherein at least one sheet that is made of a light-transmissive material and that has a multiple of raised structures having straight ridgelines at minute intervals on the same side in such a manner that the ridgelines are substantially parallel to one another or at least one sheet that is made of a light-transmissive material and that has a multiple of pyramidal or conical projecting structures at minute intervals on the same side, said projecting structures having portions of such a shape that the vertical angles are substantially the same, is provided on the exit face of the lig

Abstract: In a back lighting device for a side light type panel, one end portion of a specular or light diffusing/reflecting film covering a linear light source is bonded to one end portion of a light conducting plate which is on the side of its light emerging surface and is in proximity of the linear light source, and a light diffusing/reflecting film is laid through an air layer on the part of the rear surface of the light conducting plate which corresponds to the junction. The back lighting device of the invention is small in size, large in effective light emitting area when compared with its external dimensions, and excellent in the distribution of luminance. Hence, it can be used as a back light device that is highly efficient in converting power to luminance.