Image sensor unit and image reading apparatus

An image sensor unit that performs image reading by reflected light and image reading by transmitted light with respect to an object of illumination, comprising:

• a first light guide that emits light from a first light source toward said object of illumination;
• a second light guide that emits light from a second light source toward said object of illumination;
• an imaging element that focuses light from said object of illumination;
• and
• a light receiving element that converts light that is collected by said imaging element into an electric signal,
• wherein said second light source and said second light guide are disposed on the opposite side of a conveyance path through which said object of illumination can pass, from said first light source and said first light guide, and
• a light blocking member that continuously blocks a part of light from said first light guide is disposed between said first light guide and said second light guide.