| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a light emitting diode device as a point light source which can provide a single-lobed intensity distribution and a sufficient luminous intensity even when the translucent resin for increasing light take-out efficiency is provided on a light source LED chip. SOLUTION: In an extraction surface of light from a point light source LED chip 18, that is, in an upper surface of Fig. 1, a dome-shaped cover resin 32 of a semi-spherical shape and made of light transmissive resin is fixedly mounted so as to cover a light emitting region of at least a central part of the light extraction surface. Therefore, a total reflection angle of light from interior of the light source LED chip 18 into the cover resin 32 is made large, thus providing a high light extraction efficiency. Further, assuming that the cover resin 32 has a height of (h) from an upper surface of the chip 18 and has a radially-directed distance from the light emission region of the chip 18, or more precisely from a central part of the region is denoted by (r); then the cover resin 32 is fixed mounted on one surface of the chip 18 so as to satisfy a shape condition of 0.75<=h/r<=1.25. As a result, a single peak intensity distribution and a sufficient luminous intensity can be obtained.</p> |
