| 摘要 |
PROBLEM TO BE SOLVED: To provide an illumination device which is thin and which alleviates glare on a user side.SOLUTION: An illumination device includes: a light source unit 10 having a planar light emission region R; a power supply unit 20; a housing 30 accommodating the light source unit 10 and the power supply unit 20 in a state where they are provided parallel with respect to one surface of a building material 3, and having an opening S for emitting light; and a translucent light diffusion cover 40 for covering the opening S. When a region overlapping with the light emission region Rin the light diffusion cover 40 in a plan view is defined as a region 40a immediately under the light source, and a region other than the light source region is defined as 40b, the total sum of transmittance of the members where the light passes through in an optical path up to the point where the light emitted from the light emission region Rpasses the region 40a immediately under the light source of the light diffusion cover 40 is smaller than the total sum of transmittance of the members where the light passes through in the optical path up to the point where the light emitted from the light emission region Rpasses the region 40b which is not immediately under the light source of the light diffusion cover 40. |
