LIGHT EMITTING UNIT AND PHOTOELECTRIC SMOKE DETECTOR, AND SUCTION-TYPE SMOKE DETECTION SYSTEM

摘要

The present invention is able to detect smoke with high accuracy. A light emitting unit according to the present invention includes a light emitting element for outputting high luminance inspection light having an adjusted luminance distribution, a reflection section for focusing the inspection light from the light emitting element toward the detection area, an aperture section which allows inspection light traveling to the detection area to pass through and eliminates light scattering to areas other than the detection area, and a light blocking section which blocks light scattering to areas other than the detection area. The light emitting element includes a light source for outputting high luminance inspection light and a parabola reflection mirror provided with a curved surface such that light from the light source is reflected thereby and travels toward the detection area as the inspection light. The curved surface of the parabola reflection mirror is set such that the inspection light results in light emission which is not only generally circular but also has a doughnut shape in which the center of the circle is relatively dark and the periphery is bright.