Abstract: A backlight system for illuminating a display device comprises a light-emitting panel (1) having a front wall, an opposing rear wall and edge areas (4). At least one of the edge areas (4) is light-transmitting and associated with a light source. The light source associated with the light-transmitting edge areas (4) of the light-emitting panel (1) comprises symmetric clusters (C) of light-emitting diodes having three mutually different light emission wavelengths, for example symmetric clusters (C) of blue, green and red LEDs (6G, 6B, 6R, 6B′, 6G′; 6G, 6B, 6R, 6B′, 6G′; . . . ).

Abstract: An illumination system for illuminating a display device (3) comprises a light-emitting panel (1) having a light-emission window (2) and at least one edge surface (4) for coupling light into the light-emitting panel (1). The illumination system further comprises a light mixing chamber (5) provided with a light source (6). The light mixing chamber (5) is associated with the edge surface (4). According to the invention, the light source (6) comprises a plurality of clusters of light-emitting diodes (LEDs) having different light-emission wavelengths, the clusters being arranged at a pitch P with respect to each other. The ratio of the height H of the light mixing chamber (5) to the pitch P of the clusters meets the relation 0.1≦H/P≦10, preferably 0.2≦H/P≦2. Preferably, each cluster comprises one blue, one green and one red LED, or one blue, two green and one red LEDs. Preferably, each LED has a luminous flux of at least 5 lumen.

Abstract: The invention relates to a light panel (12), comprising: a light guide having a front surface defining a viewing window (11), a back surface and sides (3, 4) between the front and back surfaces; and a patterned array of light sources (8, 9, 10) of at least two types, which types are distinguished by the color of light emitted by the light sources of said at least two types, said array being arranged along at least one of the sides. Each light source generates in use a divergent light beam of a color into the panel to, in combination, color the panel. Further, the array comprises complementary sub-arrays (8,9,8,9 & 9,10,9,10) of light sources along at least two of the sides.

Abstract: A backlight system for illuminating a display device comprises a light-emitting panel (1) having a front wall, an opposing rear wall and edge areas (4). At least one of the edge areas (4) is light-transmitting and associated with a light source. The light source associated with the light-transmitting edge areas (4) of the light-emitting panel (1) comprises symmetric clusters (C) of light-emitting diodes having three mutually different light emission wavelengths, for example symmetric clusters (C) of blue, green and red LEDs (6G, 6B, 6R, 6B′, 6G′; 6G, 6B, 6R, 6B′, 6G′; . . . ) FIG. 2A.

Abstract: A backlight system comprises at least two light-emitting panels (1; 11) having a front wall (2; 12), an opposing rear wall (3; 13) and opposite edge surfaces (4, 14; 5, 15). At least one of the edge surfaces (4; 14) is light-transmitting and associated with a light source (6; 16). Light originating from the light source (6; 16) is diffused in the light-emitting panels (1; 11) and coupled out of the light-emitting panels (1; 11) in the direction of a display device (25), preferably a LCD device. The light source (6) associated with the light-emitting panel bearing reference numeral 1 comprises clusters of red and blue or red and green LEDs. The light source (16) associated with the light-emitting panel bearing reference numeral 11 comprises clusters of blue and green LEDs or only green LEDs.

Abstract: The system comprises a display device having a pattern of pixels associated with color filters (5B, 5G, 5R) and a backlight system for illuminating the display device, which backlight system comprises a light-emitting panel (11) and a light source (16) associated with the light-emitting panel (11). The light source (16) comprises a plurality of light-emitting diodes (LEDs) of at least three different colors, the LEDs being associated with the color filters (5B, 5G, 5R). Preferably, the spectral emission of each of the LEDs substantially matches the transmission spectrum of the color filters (5B, 5G, 5R). Preferably, the bandwidth (FWHM=full width at half maximum) of the LEDs ranges from 10≦FWHM≦50 nm. Preferably, the intensity of the light emitted by the LEDs varies with the light level of the image to be displayed by the display device. Preferably, the intensity of the light emitted by the backlight system is controllable on a frame-to-frame basis and, preferably, for each color.

Abstract: A backlight system for illuminating a display device (3) comprises a light-emitting panel (1) having a light-emission window (2) and at least one edge surface (4) for coupling light into the light-emitting panel (1). The backlight system further comprises a light mixing chamber (5) provided with a light source (6). The light mixing chamber (5) is associated with the edge surface (4). According to the invention, the light source (6) comprises a plurality of clusters of light-emitting diodes (LEDs) having different light-emission wavelengths, the clusters being arranged at a pitch P with respect to each other. The ratio of the height H of the light mixing chamber (6) to the pitch P of the clusters meets the relation 0.1≦H/P≦10, preferably 0.2≦H/P≦2. Preferably, each cluster comprises one blue, one green and one red LED, or one blue, two green and one red LEDs. Preferably, each LED has a luminous flux of at least 5 lumen.

Abstract: A backlight system comprises at least two light-emitting panels (1; 11) having a front wall (2; 12), an opposing rear wall (3; 13) and opposite edge surfaces (4, 14; 5, 15). At least one of the edge surfaces (4; 14) is light-transmitting and associated with a plurality of light sources (6, 16). Light originating from the light sources (6; 16) is diffused in the panel (1; 11). Sub-surfaces (8, 18) of the rear walls (3, 13) are provided with means for extracting light from the panel (1, 11). In operation, said sub-surfaces (8, 18) project light on areas (9, 19) of an (imaginary) plane (40) which is positioned parallel to the light-emitting panels (1, 11). Said projected areas (9, 19) in the plane (40) are substantially contiguous. Preferably, said sub-surfaces (8, 18) are remote from the light-transmitting edge surfaces (4; 14). Preferably, each of said sub-surfaces (8, 18) forms a single surface covering half the front wall (2, 12) of the light-emitting panel (1, 11).

Abstract: The system comprises a display device with a pattern of pixels (3) controlled by a control circuit (8) and a backlight system for illuminating the display device, which backlight system comprises a light-emitting panel and a light source (16, 16′, 16″, . . . ) associated with the light-emitting panel. The light source comprises a plurality of light-emitting diodes (LEDs) of at least two different colors. The control circuit (8) also controls the luminous flux of the LEDs. Preferably, the intensity of the light emitted by the LEDs (16, 16′, 16″) varies with the light level of the image to be displayed by the display device. Preferably, the intensity of the light emitted by the backlight system can be controlled on a frame-to-frame basis and, preferably, also for each color. Preferably, the LEDs comprise a plurality of red, green, blue (and amber) LEDs, each, preferably, having a luminous flux of at least 5 lumen.