Abstract: A display unit incorporating a light guiding plate. The light guiding plate formed of a transparent plate has on at least a part of its reverse side a reflection surface made of a minutely uneven surface. Immediately behind the light guiding plate disposed is a viewing object display on which an object to be viewed is drawn. The viewing object display is at least partially drawn with a visible light conversion reflection material capable of reflecting invisible light such as ultraviolet light in the form of visible light. The portion drawn with the visible light conversion reflection material is positioned correspondingly behind the reflection surface of the light guiding plate. A light source for emitting invisible light and a light source for emitting visible light are provided. At least the invisible light emitting source is located on at least a part of one lateral edge of the light guiding plate.

Abstract: A light guiding plate has grooves or ridges with respective bottom or peak portions having surfaces with curvilinear sectional contours. The curvilinear portions replace angular intersections of slanted surfaces of the grooves or ridges and thereby provide uniform luminance over an entire face of the light guiding plate.

Abstract: Disclosed is a lighting unit of an indirect type, capable of varying the luminance and color of illumination with respect to a target to be lit thereby ensuring an effective display of the target, and further capable of using itself as a display unit. The lighting unit comprises a light guide plate having one side fashioned into an uneven surface or a reflective surface; a plurality of light emitting diodes for supplying a light to the light guide plate, the light derived from the diodes being dispersed through the light guide plate; and a control section which controls actions including blinking of the light emitting diodes. At least a part of the diodes is intended to emit a light different in color from that of the others so that the color or blinking of illumination can be arbitrarily varied through the control by means of the control section.