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

摘要

The present invention can detect smoke with high accuracy. A light emitting portion of the present invention is provided with a light emitting element outputting the inspection light with high brightness whose brightness distribution is adjusted; a reflection portion collecting the inspection light from the light emitting element to the detection region; a diaphragm portion transmitting the inspection light traveling toward the detection region and to remove light diffused to regions other than the detection region; and a light shielding portion shielding the light diffused to the regions other than the detection region. The light emitting element is provided with a light source outputting the inspection light with high brightness and a parabola reflective mirror whose curved surface is set so that light from the light source is reflected and becomes the inspection light toward the detection region. The curved surface of the parabola reflective mirror is set so as to emit light in a circular shape as a whole by means of the inspection light and to emit light in a doughnut shape in which the center of the circle is relatively dark and the periphery is bright.