Image scanner, image forming apparatus and image adjusting method of image scanner

An image scanner comprising:

• a light source that irradiates, with light, a recording medium on which an image is formed;
• a light receiving portion that receives light reflected by the recording medium;
• a generating portion that generates a light amount value from the light received by the light receiving portion;
• a measuring portion in which a plurality of reflecting surfaces are disposed, the reflecting surfaces respectively having predetermined colors different from each other;
• and
• a processing portion that derives a correlation formula from a predetermined light amount value and from a light amount value generated when the reflecting surfaces of the measuring portion are irradiated with the light from the light source, the correlation formula expressing differences between devices in scanning a light amount value.

An image forming apparatus comprising:

• an image forming portion that forms an image on a recording medium;
• a scanner unit that scans the image on the recording medium in order to adjust an image to be formed on the recording medium by the image forming portion, the scanner unit including:
• a light source that irradiates, with light, the recording medium on which the image is formed;
• a light receiving portion that receives light reflected by the recording medium;
• a generating portion that generates a light amount value from the light received by the light receiving portion;
• and
• a measuring portion in which a plurality of reflecting surfaces are disposed, the reflecting surfaces respectively having predetermined colors different from each other;
• and
• a processing portion that derives a correlation formula for a predetermined light amount value and a light amount value generated when the reflecting surfaces of the measuring portion of the scanner unit are irradiated with the light from the light source.