Image reading apparatus and image forming apparatus capable of suppressing deterioration of image quality

An image forming apparatus comprising:

• an image reading unit comprising:
• a light source that is configured to light up at luminance associated with supplied electric current;
• an electric-current supplying section that is configured to supply the light source with electric current;
• a control section that is configured to control the electric-current supplying section;
• a reading section that is configured to read at least one sheet of an original document on which light from the light source is irradiated and to generate image data;
• and
• a determining section that is configured to determine whether a change in the electric current flowing through the light source is large, based on a predetermined criterion, during a period when the reading section reads the at least one sheet of the original document,
• wherein, when the reading section reads the at least one sheet of the original document, the control section is configured to increase electric current supplied to the light source if the determining section determines that the change is large relative to electric current supplied to the light source when the determining section determines that the change is small;
• and
• an image forming unit that is configured to form an image on a recording medium based on the image data generated by the image reading unit.

An image reading apparatus comprising:

• a light source that is configured to light up at luminance associated with supplied electric current;
• electric-current supplying means for supplying the light source with electric current;
• control means for controlling the electric-current supplying means;
• reading means for reading at least one sheet of an original document on which light from the light source is irradiated and for generating image data;
• and
• determining means for determining whether a change in the electric current flowing through the light source is large, based on a predetermined criterion, during a period when the reading means reads the at least one sheet of the original document,
• wherein, when the reading means reads the at least one sheet of the original document, the control means increases electric current supplied to the light source if the determining means determines that the change is large relative to electric current supplied to the light source when the determining means determines that the change is small.