| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an illumination device in which individual differences of light sources are compensated, in which there are few individual differences in chromaticity and/or brightness of light emitted as illumination light, and in which quality is stable. <P>SOLUTION: In the illumination device provided with the light source and a planar light guide plate to guide light incident from the light source and to emit the guided light from a light emitting face, an optical element for light emission composed of a diffraction grating is arranged at a light emitting face or a face opposed to the light emitting face, and the optical element for the light emission having a spatial frequency distribution and/or a diffraction efficiency of the compensated diffraction grating is provided for the purpose that the light emitted from the light guide plate becomes within the range of chromaticity and/or brightness prescribed according to wavelength distribution and/or brightness of the light incident into the light guide plate from the light source. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
