Image reading apparatus and an image forming apparatus having the image reading apparatus

An image reading apparatus apparatus including an original base forming a predetermined image reading region is and being adapted to receive an original placed thereon, image reading means that is disposed below said original base and reads an image of the original, and an original automatic conveying apparatus that conveys the original to said image reading region,

• wherein said image reading apparatus reads the image of the original by selecting one of an original fixing scanning mode and an image flow reading scanning mode, the original fixing scanning mode being a mode in which the original is placed on said original base and the image of the original is read by said image reading means performing scanning in a predetermined scanning direction below said original base, and the image flow reading scanning mode being a mode in which said image reading means is set to stay below said image reading region and the image of the original is read using said image reading means in said image reading region by conveying the original to said image reading region using said original automatic conveying apparatus,
• said image reading apparatus comprising:
• an abutting member which is formed in the vicinity of one end portion of said original base and against which the original placed on said original base is abutted when the original fixing scanning mode is selected;
• a conveying guide base that is formed on another end portion side of said original base opposite to said abutting member and guides the original, which is conveyed to said image reading region toward a direction of the other end portion from the one end portion by said original automatic conveying apparatus, to a predetermined original discharging tray;
• detecting means for detecting that the original is placed on original placing means included within said original automatic feeding apparatus;
• image reading operation start means that is operated to start an image reading operation;
• and
• position control means for moving said image reading means from a stand-by position to a predetermined reading position before the original is fed by said original automatic feeding apparatus,
• wherein if a detection signal is inputted from said detecting means when said image reading operation start means is operated, said position control means moves said image reading means from said stand-by position to said predetermined reading position.