| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reading device which improves detection accuracy of document size by simple configuration.SOLUTION: An image reading device includes a contact glass 10, a frame 20, a light-emitting part 31, a sensor 34, and a control section. A manuscript M is mounted on the contact glass 10. The frame 20 surrounds the circumference of the contact glass 10. The light-emitting part 31 emits light toward the contact glass 10 and frame 20. The sensor 34 receives first reflection light passed through the contact glass 10 and second reflection light from the frame 20, and detects the first light reception amount of the first reflection light and second light reception amount of the second reflection light. The control section compares variation of the first light reception amount and second light reception amount. The control section determined whether or not the variation of the first light reception amount indicates existence of the manuscript M, with reference to variation of the second light reception amount.SELECTED DRAWING: Figure 2 |
