Patent ID: 8462402

Claim:
A method of controlling a light source in an image scanning apparatus, the method comprising: emitting light from the light source onto a reference surface having a predetermined reflectivity; detecting a shading level representing an intensity of the light reflected from the reference surface; comparing the detected shading level with a reference level representing the predetermined reflectivity of the reference surface; and controlling the intensity of the light emitted from the light source by using the detected shading level and the reference level according to a result of the comparison, wherein, in the comparing of the shading level with the reference level, the shading level is compared with a predetermined range of the reference level, and in the controlling of the light intensity, the current applied to the light source is adjusted according to the ratio of the reference level with respect to the shading level to control the light intensity, when the shading level is not included in the predetermined range of the reference level.