IMAGE READING DEVICE, IMAGE FORMING APPARATUS, AND OPTICAL UNIT

摘要

An optical unit of an image reading device has the center of gravity in a position toward a first sub scanning direction, relative to the middle point of the optical unit in terms of sub scanning directions. An engagement part is provided in a position toward a first main scanning direction relative to a sliding part. A plurality of pairs of pinching parts include a first pair provided in a position toward the first sub scanning direction and a second pair provided in a position toward a second sub scanning direction. Of the two pinching parts in the second pair, the pinching part provided in a position toward the first main scanning direction is biased by a first biasing member toward a rail part side, and the pinching part provided in a position toward a second main scanning direction is not biased by the first biasing member.

主权项

1. An image reading device comprising:
a document table on which an original document is loaded; an optical unit that is positioned underneath the document table and is configured to read an image from the original document loaded on the document table by scanning the original document in at least one of sub scanning directions; a rail part that is provided so as to extend in the sub scanning directions and is configured to support the optical unit in such a manner that the optical unit is slidable in the sub scanning directions; and a driving device configured to move the optical unit in the sub scanning directions, wherein the optical unit includes:
a sliding part configured to slide while being in contact with the rail part;a plurality of pairs of pinching parts, each of the pairs of pinching parts being configured to pinch the rail part from both sides thereof in terms of main scanning directions that are orthogonal to the sub scanning directions;a first biasing member that is provided for at least one of the pinching parts and is configured to bias the pinching part toward the rail part side; andan engagement part configured to be engageable with the driving device, a center of gravity of the optical unit is in a position toward a first sub scanning direction, relative to a middle point of the optical unit in terms of the sub scanning directions, the first sub scanning direction being one of the sub scanning directions, the engagement part is provided in a position toward a first main scanning direction relative to the sliding part, the first main scanning direction being one of the main scanning directions, the plurality of pairs of pinching parts include a first pair and a second pair that are arranged along the sub scanning directions, the second pair is provided in a position toward a second sub scanning direction relative to the first pair, the second sub scanning direction being the other of the sub scanning directions, and of the two pinching parts in the second pair,
the pinching part provided in a position toward the first main scanning direction is biased by the first biasing member toward the rail part side, andthe pinching part provided in a position toward a second main scanning direction is not biased by the first biasing member, the second main scanning direction being the other of the main scanning directions.