A light source for illuminating a display panel comprises a light-emitting device such as an incandescent light bulb or LED array disposed within a cavity having diffusely reflecting walls and an aperture. In one embodiment, a diffuser and brightness enhancing film are situated proximate the opening of the aperture which illuminates the display. Preferably, light emerging from the aperture is substantially uniform in intensity and color, and in one embodiment, a color filter is employed to whiten the light emerging from the aperture. The ratio of the area of the aperture to the sum of such area and the surface area of the cavity is at least 0.05. The sides of the cavity are sloped so as to reduce the sum and increase the ratio.