| 摘要 |
<p>A light emitting diode (1) and a condenser lens (2) are arranged in an optical axis direction. In the light emitting diode (1), a cover (4) having a tip end lens (5) is attached to one side of a main unit base (9), a light emitting chip (6) is supported by a bonding wire (8) drawn out from the body base (9) inside the cover 4), and a reflector (7) is placed behind the light emitting chip (6). With respect to a first light source of the light emitting chip (6), the position, where light which is forward reflected by the reflector (7) impinges on the tip end lens (5), is set as a virtual second light source (10), and the focal point of the condenser lens (2) is set at the position of or in the vicinity of the position of the second light source (10). In this way the light intensity distribution in a beam section perpendicular to the optical axis of the composite light can be substantially uniformalized, with special use in reflection-type smoke sensors.</p> |
