Image reading apparatus and image forming apparatus including a being-conveyed document reading mode and a placed-document reading mode

An image reading apparatus comprising:

• a for-still-document contact glass configured to serve as a reading face for a placed document;
• a for-moving-document contact glass configured to serve as a reading face for a document conveyed by an automatic document feeder;
• and
• an optical scanner unit configured to move in a scanning range of the for-still-document contact glass back and forth in a sub-scanning direction to scan the document, the optical scanner unit being configured to move to a scanning range of the for-moving-document contact glass and scan the document in a static manner in response to the document being conveyed in an automatic manner, the optical scanner unit including a contact image sensor, a carriage holding the contact image sensor in a movable manner in the sub-scanning direction, a pair of end sliders on both ends of a plane facing the reading face in a longer-side direction of the optical scanner unit, and a pair of central sliders at a center of longer-side direction, the pair of central sliders being on both right and left sides of the contact image sensor in a moving direction of the optical scanner unit,
• wherein, when the optical scanner unit is at a home position before scanning operation starts, one of the pair of central sliders is at a position overlapping with the for-still-document contact glass when viewed in a vertical direction of the optical scanner unit, and clearance in a horizontal direction between a front end of the contact image sensor in a scanning direction and an end of the for-still-document contact glass is shorter than length of a pair of faces of the pair of central sliders facing the reading face in a horizontal direction.

An image reading apparatus comprising:

• a for-still-document contact glass configured to serve as a reading face for a placed document;
• a for-moving-document contact glass configured to serve as a reading face for a document conveyed by an automatic document feeder;
• and
• an optical scanner unit configured to move in a scanning range of the for-still-document contact glass back and forth in a sub-scanning direction to scan the document, the optical scanner unit being configured to move to a scanning range of the for-moving-document contact glass and scan the document in a static manner in response to the document being conveyed in an automatic manner, the optical scanner unit including a contact image sensor, a carriage holding the contact image sensor in a movable manner in the sub-scanning direction, a pair of end sliders on both ends of a plane facing the reading face in a longer-side direction of the optical scanner unit, and a pair of central sliders at a center of longer-side direction, the pair of central sliders being on both right and left sides of the contact image sensor in a moving direction of the optical scanner unit,
• wherein, when the optical scanner unit is at a home position before scanning operation starts, one of the pair of central sliders is at a position overlapping with the for-still-document contact glass when viewed in a vertical direction of the optical scanner unit, and
• wherein the pair of central sliders are displaced in a direction in which the pair of faces are pressurized in response to a pair of faces of the pair of central sliders facing the reading face being pressurized.