Light emission portion, photoelectric smoke sensor, and suction-type smoke sensing system

摘要

The present invention can detect smoke with high accuracy. A light emitting portion is provided with a light emitting element outputting the inspection light with high brightness, the distribution of which is adjusted. A reflection portion collects the inspection light from the light emitting element to the detection region. A diaphragm portion transmits the collected light toward the detection region, while removing light diffused to regions other than the detection region a light shielding portion shields 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 parabolic reflective mirror whose curved surface reflects light from the light source toward the detection region, the reflected light being in a doughnut shape in which the center is relatively dark and the periphery is bright.

主权项

1. A light emitting portion which collects inspection light in a detection region, comprising:
a light emitting element outputting the inspection light with high brightness whose brightness distribution is adjusted; a reflection portion provided on the detection region side of the light emitting element and collecting the inspection light from the light emitting element to the detection region; a diaphragm portion provided on the detection region side of the reflection portion and 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 provided on the detection region side of the diaphragm portion and shielding the light diffused to the regions other than the detection region, wherein 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; and 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, wherein the diaphragm portion allows the inspection light not reflected by the reflection portion in the inspection light emitted from the parabola reflective mirror to pass therethrough and to directly irradiate the detection region; and wherein the reflection portion has a conical reflecting surface expanded to the detection region side; and an inclination angle of the reflecting surface is set to an angle at which the inspection light having the doughnut-shaped high brightness portion is collected in the detection region.