A handling system, comprising: a pattern irradiation device (20, 50, 60, 70, 80, 90, 110, 120, 130, 140, 150) that is configured to irradiate an object in a predetermined pattern; a three-dimensional measuring device that is configured to measure a distance to the object irradiated with light by the pattern irradiation device; a recognizing device that is configured to recognize a position and posture of the object based on the distance to the object measured by the three-dimensional measuring device; a robot that is configured to handle the object; and a robot controller that is configured to control operation of the robot based on the position and the posture of the object recognized by the recognizing device, to control the robot to handle the object; characterised in that the pattern irradiation device (20, 50, 60, 70, 80, 90, 110, 120, 130, 140, 150) comprises: a light emitting unit that is configured to output monochromatic light; a light condensing unit that is configured to condense the light output from the light emitting unit; a diffusion unit (33, 51, 111, 121, 131, 141, 151) that is configured to diffuse the light condensed by the light condensing unit; a uniformizing optical system (34, 61) that is configured to receive the light diffused by the diffusion unit, to uniformize a brightness distribution thereof compared with that of the light being received, and to output the resulting light; and a photo mask on which a predetermined image pattern is drawn, said photo mask being configured to transmit light output from the uniformizing optical system (34, 61) according to the predetermined image pattern. a pattern irradiation device (20, 50, 60, 70, 80, 90, 110, 120, 130, 140, 150) that is configured to irradiate an object in a predetermined pattern; a three-dimensional measuring device that is configured to measure a distance to the object irradiated with light by the pattern irradiation device; a recognizing device that is configured to recognize a position and posture of the object based on the distance to the object measured by the three-dimensional measuring device; a robot that is configured to handle the object; and a robot controller that is configured to control operation of the robot based on the position and the posture of the object recognized by the recognizing device, to control the robot to handle the object; characterised in that the pattern irradiation device (20, 50, 60, 70, 80, 90, 110, 120, 130, 140, 150) comprises: a light emitting unit that is configured to output monochromatic light; a light condensing unit that is configured to condense the light output from the light emitting unit; a diffusion unit (33, 51, 111, 121, 131, 141, 151) that is configured to diffuse the light condensed by the light condensing unit; a uniformizing optical system (34, 61) that is configured to receive the light diffused by the diffusion unit, to uniformize a brightness distribution thereof compared with that of the light being received, and to output the resulting light; and a photo mask on which a predetermined image pattern is drawn, said photo mask being configured to transmit light output from the uniformizing optical system (34, 61) according to the predetermined image pattern. a light emitting unit that is configured to output monochromatic light; a light condensing unit that is configured to condense the light output from the light emitting unit; a diffusion unit (33, 51, 111, 121, 131, 141, 151) that is configured to diffuse the light condensed by the light condensing unit; a uniformizing optical system (34, 61) that is configured to receive the light diffused by the diffusion unit, to uniformize a brightness distribution thereof compared with that of the light being received, and to output the resulting light; and a photo mask on which a predetermined image pattern is drawn, said photo mask being configured to transmit light output from the uniformizing optical system (34, 61) according to the predetermined image pattern.