Abstract: An illumination system (8) comprises an optical waveguide (18) which is made from optically transparent components and has four end faces (10, 10?). A light source (12) whose light is coupled into the optical waveguide (18) via one of the end faces (10) is situated opposite this end face (10). The optical waveguide (18) has a light guide (30). A birefringent layer (36) comprising liquid crystals is provided on the light guide (30) at an exit surface side thereof. A first electrode (40) and a second electrode (44) both have electrical contact with the birefringent layer (36) and are connected to a voltage generator (46). By varying the voltage applied between the electrodes (40, 44), the birefringent properties of the birefringent layer (36) comprising the liquid crystals may be varied to control the direction of light coupled out via the exit surface (16).

Abstract: To increase an amount of the light that can be used for the display efficiently in the total amount of the emitted light in the liquid crystal display device having the surface lighting device such as the front-light. The light (a) becomes the light component of the linearly polarized light by passing the retardation plate (11a). In the reflective polarizer (11b), only the light (b) that is a component of the polarization axis of the reflective polarizer (11b) passes through the reflective polarizer (11b) to enter into the end portion of the light guide (12). The light that is a component other than the component of the polarization axis of the reflective polarizer (11b) is reflected on the reflective polarizer (11b). The light reflected on the reflective polarizer (11b) changes from the linearly polarized light to the circularly polarized light by passing through the retardation plate (11a).

Abstract: An object of the invention is to provide a surface illumination device and a display device using it, which can contribute to improvement of display qualities. A surface illumination device 10 comprising a light guide plate 1 for propagating incident light inside itself and reflecting the light at the reflecting prism face 1S to output the light from the light exit face. This further comprises: a polarizing plate 3 provided on the light exit face; and an anti-reflection film 4 provided on the polarizing plate 3. The reflecting prism face 1S extends so that a direction of electric vector's vibration of an s-polarized light component of a reflecting light ray caused by an incident light ray in a predetermined propagation direction is in parallel with a polarization axis of the polarizing plate 3, whereby a light efficiency can be improved.

Abstract: A side-lit illumination arrangement comprises a polarized-light-emitting waveguide comprising a polarization-selective beam-splitting interface formed at an interface of a waveguiding layer and a polarization-selection layer. In order to avoid alignment problems occurring during the manufacture of the waveguide which impair the proper functioning of the polarization-selective beam-splitting interface, the polarization-selective beam-splitting interface is planar. Waveguided light polarized and transmitted by the polarization-selective beam-splitting interface into the polarization-selection layer is coupled out by a relief-structured surface via an exit surface. Display devices having such waveguides, in particular if used in a front light, have a high brightness and efficiency.