Image sensor module for image reading apparatus with improved reading flexibility

An image sensor module for reading a hologram, comprising:

• a sensor IC (Integrated Circuit) having a plurality of light receivers arranged along a main scanning direction;
• a lens unit configured to form an image on the sensor IC with light transferred from a read target, arranged at one end of the image sensor module in a sub-scanning direction perpendicular to the main scanning direction;
• a first light source unit having a first output surface extending along the main scanning direction and outputting a first linear light extending along the main scanning direction from the first output surface toward the read target and being reflected to the lens unit from the read target, the first output surface being placed at a position spaced apart from the lens unit in the sub-scanning direction;
• and
• a second light source unit having a second output surface extending along the main scanning direction and outputting a second linear light extending along the main scanning direction from the second output surface toward the read target and being reflected to the lens unit from the read target, the second output surface being placed between the lens unit and the first output surface in the sub-scanning direction,
• wherein the first output surface, the second output surface, and the lens unit are arranged in the same case to overlap in the sub-scanning direction,
• wherein the first and second light source units are arranged opposite from the lens unit arranged at the one end of the image sensor module in the sub-scanning direction, and emit light in different angles to the read target with respect to the lens unit, and
• wherein the first and second light source units are arranged to overlap each other in the sub-scanning direction and arranged at different heights in a thickness direction perpendicular to the main scanning direction and the sub-scanning direction.