Image reading device

An image reading device comprising:

• a light guide extending in a main scanning direction and configured to emit light from a light source toward a reading target moving relatively in a sub-scanning direction, the light from the light source being projected into an end surface of the light guide in the main scanning direction;
• an optical filter arranged between the light source and the end surface of the light guide in the main scanning direction and configured to block or attenuate light having a specific wavelength from the light from the light source;
• a lens body to focus reflected light reflected by the reading target onto a light receiver to convert the reflected light into an electrical signal;
• and
• a lens holder to hold the light guide, the optical filter, and the lens body, wherein
• the lens holder includes (i) a first positioner for positioning the light guide in the sub-scanning direction and in a height direction that is orthogonal to the main scanning direction and the sub-scanning direction and (ii) a second positioner for positioning the optical filter in the height direction and the sub-scanning direction.