Image reading device and image forming apparatus including an illuminating unit and an aligning portion for positioning an original

摘要

An image reading device includes a platen on which an original is to be placed, an illuminating unit configured to illuminate the original, a linear sensor configured to receive light from the original, an optical unit configured to guide the light from the original to the linear sensor, and an aligning portion configured to determine a position of the original in a long-side direction of the linear sensor. The illuminating unit includes a light-guiding member extending in the long-side direction of the linear sensor, and a light source provided only at one long-side end of the light-guiding member. The aligning portion is provided on a side opposite to the light source in the long-side direction of the light-guiding member.

主权项

1. An image reading device comprising:
a platen on which an original is to be placed; an illuminating unit configured to illuminate the original; a linear sensor extending in a first direction and configured to receive light from the original; an optical unit configured to guide the light from the original to the linear sensor; and an aligning portion configured to determine a position of the original in the first direction, wherein the illuminating unit includes
a light-guiding member extending in the first direction,
wherein the light-guiding member includes an optical surface provided with a plurality of prisms that are arranged in the first direction; anda light source provided only at one end of the light-guiding member in the first direction,
wherein, in the first direction, a distance between a center axis of the optical surface and the light source is shorter than a distance between an optical axis defined by the optical unit and the light source, wherein the illuminating unit illuminates the original only from the one end side in the first direction, and wherein the aligning portion is provided on a side opposite to the light source in the first direction.