Image reading apparatus

An image reading apparatus comprising:

• a lens unit having a low-resolution lens, a high-resolution lens and a first driving unit to drive the lenses;
• and
• a second driving unit to drive the lens unit,
• wherein, during a reading operation at a first resolution, the first driving unit drives the low-resolution lens and high-resolution lens and the second driving unit drives the lens unit, whereby the low-resolution lens is placed on the optical axis at a first location and the high-resolution lens is placed off the optical axis,
• wherein, during a reading operation at a second resolution, higher than the first resolution, the first driving unit drives the low-resolution lens and high-resolution lens and the second driving unit drives the lens unit, whereby the low-resolution lens is placed off the optical axis and the high-resolution lens is placed on the optical axis at a second location, and
• wherein, during a reading operation at a third resolution, higher than the second resolution, the first driving unit drives the low-resolution lens and high-resolution lens and the second driving unit drives the lens unit, whereby the low-resolution lens is placed off the optical axis and the high-resolution lens is placed on the optical axis at a third location.