| 摘要 |
PURPOSE:To give directivity to light, to provide high luminance and a long life and to flatten a light emitting luminance distribution in one light emitting region, by providing a P-N junction so that at least a part of the P-N junction is aligned in the light emitting direction. CONSTITUTION:Each groove 3 is provided in a light emitting region 2. A P-N junction is formed at a specified depth from the surface of a substrate. Therefore the P-N junction is vertically arranged with respect to the surface of the substrate 1, i.e., in the direction aligned with the light emitting direction. As a result, a near pattern is lifted at the side surface of the groove 3, and the expansion of the pattern is reduced. The reasons are as follows: the area of the P-N junction 4 is broadened; the P-N junction is aligned with the light emitting direction; and light is reflected by the side surface of the groove and, especially, the light emitted from the bottom surface is directed upward. Therefore, the illuminance at a light sensitive surface per light emitting region becomes high by 20-35%. The ratio of maximum luminance : minimum luminance in the near pattern becomes 1:0.8 and the ratio is made uniform. |
