An obstacle sensing module for a cleaning robot, comprising: at least one light emitter comprising: a light source; a wide-angle lens formed of a transparent material to allow light incident from the light source to pass therethrough, the wide-angle lens comprising: a first surface to receive the incident light from the light source, and a second surface, including a second refracting surface to refract light having an incidence angle smaller than a critical angle and a second reflecting surface to totally reflect light having an incidence angle equal to or greater than the critical angle, to generate planar light; and a light source driver to drive the light source to emit light; and a light receiver comprising: a reflection mirror to reflect the planar light reflected by an obstacle to generate reflection light, an optical lens spaced from the reflection mirror by a predetermined distance, to allow the reflection light to pass through the optical lens; an image sensor to receive the reflection light emerging from the optical lens to generate an image signal from the reflection light emerging from the optical lens; and an image processing circuit to receive the image signal, and to convert the received image signal into an image signal in the form of a digital image signal. at least one light emitter comprising: a light source; a wide-angle lens formed of a transparent material to allow light incident from the light source to pass therethrough, the wide-angle lens comprising: a first surface to receive the incident light from the light source, and a second surface, including a second refracting surface to refract light having an incidence angle smaller than a critical angle and a second reflecting surface to totally reflect light having an incidence angle equal to or greater than the critical angle, to generate planar light; and a light source driver to drive the light source to emit light; and a light source; a wide-angle lens formed of a transparent material to allow light incident from the light source to pass therethrough, the wide-angle lens comprising: a first surface to receive the incident light from the light source, and a second surface, including a second refracting surface to refract light having an incidence angle smaller than a critical angle and a second reflecting surface to totally reflect light having an incidence angle equal to or greater than the critical angle, to generate planar light; and a light source driver to drive the light source to emit light; and a light receiver comprising: a reflection mirror to reflect the planar light reflected by an obstacle to generate reflection light, an optical lens spaced from the reflection mirror by a predetermined distance, to allow the reflection light to pass through the optical lens; an image sensor to receive the reflection light emerging from the optical lens to generate an image signal from the reflection light emerging from the optical lens; and an image processing circuit to receive the image signal, and to convert the received image signal into an image signal in the form of a digital image signal. a reflection mirror to reflect the planar light reflected by an obstacle to generate reflection light, an optical lens spaced from the reflection mirror by a predetermined distance, to allow the reflection light to pass through the optical lens; an image sensor to receive the reflection light emerging from the optical lens to generate an image signal from the reflection light emerging from the optical lens; and an image processing circuit to receive the image signal, and to convert the received image signal into an image signal in the form of a digital image signal.