IMAGE READING DEVICE AND IMAGE FORMING DEVICE HAVING THE SAME

PROBLEM TO BE SOLVED: To provide an image reading device and an image forming device having the same, including a frame structure selectably mountable of two scanner units having different field depths.SOLUTION: At a center portion of a lower frame 60a relative to the main scanning direction of a scanner unit 61, there are disposed a guide shaft 63 for restricting the position of a carriage 62 in the main scanning direction, and a drive belt 65 to which the carriage 62 is fixed in the sub-scanning direction of the scanner unit 61. Also, on both end portions of the lower frame 60a in the main scanning direction around the guide shaft 63, rail portions 67a, 67b are formed to slidably support the carriage 62. On the lower frame 60a, the carriage 62 for retaining the scanner unit 61 of a CCD sensor system and a carriage 82 for retaining a scanner unit 81 of a CIS sensor system are selectably mountable.