Light-scattering dust sensor

Abstract

A light-scattering dust sensor includes: a light scattering region; a light emitter configured to emit light to the light scattering region; a light receiver configured to receive scattered light generated in the light scattering region; and an emitted light limiter located between the light emitter and the light scattering region, wherein the light emitted by the light emitter includes: peripheral light; and central light having an intensity that is more uniform than an intensity of the peripheral light, wherein the emitted light limiter is configured to block part of the emitted light, wherein the part of the emitted light blocked by the emitted light limiter includes the peripheral light.

Dependencies are inferred from the claim text.