Patent ID: 8592713

Claim:
An irradiating apparatus for irradiating an irradiation object with a beam of light emitted from a semiconductor laser, comprising: the semiconductor laser from which the beam of light is emitted; and an irradiating optical system interposed between the irradiation object and the semiconductor laser and which focuses the beam of light on the irradiation object, wherein, letting (1) w be a radius of the beam for irradiating said irradiation object, (2) Δ be a rate of individual difference in angle of divergence of said semiconductor laser, and (3) λ be the wavelength of the beam of light from said semiconductor laser, (a) a focal position of the irradiating optical system interposed between the semiconductor laser and the irradiation object is defocused from the irradiation object in a first axis direction such that a distance z between the focal position and the irradiation object is defined by the relationship z = π · w 2 λ · 1 - Δ 2 ( 1 - Δ 2 ) 2 + 1 , and (b) the focal position of the irradiating optical system interposed between the semiconductor laser and the irradiation object is focused on the irradiation object in a second axis direction, the second axis direction being perpendicular to the first axis direction.