| 主权项 |
1. An image reading device comprising:
a document conveying portion configured to convey a document sheet along a conveyance path extending sequentially through a turn-around portion at which a conveyance direction is reversed and a predetermined reading position; a document table which is provided below the document conveying portion and on which a document sheet is placed; and a reading unit movable in a predetermined moving direction below the document conveying portion and the document table, the reading unit including a unit housing in which a light source, an optical element, and an image sensor are mounted, the reading unit being formed such that, between the turn-around portion and a first end portion of the document conveying portion which is close to the turn-around portion in the moving direction, a second end portion of the unit housing at a side of the first end portion in the moving direction is located in a state where light is applied from the light source to the reading position, wherein the optical element includes a first mirror, a second mirror, a third mirror, a fourth mirror, and an optical lens, the first mirror, the second mirror, and the optical lens being arranged more on a side of the second end portion of the unit housing than the reading position in the state where light is applied from the light source to the reading position, the third mirror and the fourth mirror being arranged more on a side of a third end portion of the unit housing which is opposite to the second end portion of the unit housing, than the reading position in the state where light is applied from the light source to the reading position, the light source is arranged more on a side of the third end portion of the unit housing than the reading position in the state where light is applied from the light source to the reading position, the image sensor is arranged more on a side of the second end portion of the unit housing than the reading position in the state where light is applied from the light source to the reading position, in the reading unit, light which has been emitted from the light source and reflected on the document sheet is reflected sequentially on the first mirror, the second mirror, the third mirror, the second mirror, and the fourth mirror and enters the image sensor through the optical lens, and a dimension of the unit housing in a height direction perpendicular to the moving direction is shorter than a distance between the second end portion of the unit housing and the reading position in the moving direction. |
