An optical scanning device includes plural sets of optical paths, and in each set of optical paths, first and second light beams emitted from the two light sources having an opening angle in the main scanning direction are orthogonal to a deflection axis of a deflector and are deflected and scanned by the same surface of the deflector at different positions deviating from each other in a deflection axis direction. A first imaging optical element gives positive optical power to the deflected light beams to converge the light beams. A focal position exists between the first imaging optical element and a second imaging optical element arranged on the optical paths in front of first and second surfaces to be scanned on two photoconductive drums. A separation distance exists between the light beams.

An image reading apparatus includes a reader, a conveying path, a conveyer, a conveyer driving unit, a conveyer housing, a lighting unit, a cooler, and a frame. The reader reads an image on a sheet at a predetermined reading position. The conveying path guides the sheet having the image to the reading position and guides the sheet read by the reader in an ejecting direction. The conveyer conveys the sheet along the conveying path. The conveyer driving unit drives the conveyer. The conveyer housing supports the conveying path, the conveyer, and the conveyer driving unit. The lighting unit is fixed to an interior of the reader and illuminates the sheet conveyed by the conveyer to the reading position. The cooler cools the lighting unit. The frame separately fixes the reader and the conveyer housing. The cooler is fixed to the conveyer housing.

An optical scanning device includes plural sets of optical paths, and in each set of optical paths, first and second light beams emitted from the two light sources having an opening angle in the main scanning direction are orthogonal to a deflection axis of a deflector and are deflected and scanned by the same surface of the deflector at different positions deviating from each other in a deflection axis direction. A first imaging optical element gives positive optical power to the deflected light beams to converge the light beams. A focal position exists between the first imaging optical element and a second imaging optical element arranged on the optical paths in front of first and second surfaces to be scanned on two photoconductive drums. A separation distance exists between the light beams.

An optical scanning device includes plural sets of optical paths, and in each set of optical paths, first and second light beams emitted from the two light sources having an opening angle in the main scanning direction are orthogonal to a deflection axis of a deflector and are deflected and scanned by the same surface of the deflector at different positions deviating from each other in a deflection axis direction. A first imaging optical element gives positive optical power to the deflected light beams to converge the light beams. A focal position exists between the first imaging optical element and a second imaging optical element arranged on the optical paths in front of first and second surfaces to be scanned on two photoconductive drums. A separation distance exists between the light beams.

An optical scanning device includes plural sets of optical paths, and in each set of optical paths, first and second light beams emitted from the two light sources having an opening angle in the main scanning direction are orthogonal to a deflection axis of a deflector and are deflected and scanned by the same surface of the deflector at different positions deviating from each other in a deflection axis direction. A first imaging optical element gives positive optical power to the deflected light beams to converge the light beams. A focal position exists between the first imaging optical element and a second imaging optical element arranged on the optical paths in front of first and second surfaces to be scanned on two photoconductive drums. A separation distance exists between the light beams.

A document reading device includes a conveyer for conveying a document sheet using a single drive source, a reader for reading an image of the document sheet being conveyed through a reading position, and a controller for stopping the conveyance by the conveyer if a read request for a first document sheet, which is being conveyed upstream of the reading position in a conveyance direction, has not received. The controller invalidates the image read from a second document sheet which is being conveyed downstream of the first document sheet if the trailing edge of the second document sheet has not passed through the reading position at a timing when the conveyance is stopped because of the read request having not been received, and validates the image read from the second document sheet if the trailing edge of the second document sheet has passed through the reading position.

An image reading apparatus includes a reader, a conveying path, a conveyer, a conveyer driving unit, a conveyer housing, a lighting unit, a cooler, and a frame. The reader reads an image on a sheet at a predetermined reading position. The conveying path guides the sheet having the image to the reading position and guides the sheet read by the reader in an ejecting direction. The conveyer conveys the sheet along the conveying path. The conveyer driving unit drives the conveyer. The conveyer housing supports the conveying path, the conveyer, and the conveyer driving unit. The lighting unit is fixed to an interior of the reader and illuminates the sheet conveyed by the conveyer to the reading position. The cooler cools the lighting unit. The frame separately fixes the reader and the conveyer housing. The cooler is fixed to the conveyer housing.

A document reading device includes a conveyer for conveying a document sheet using a single drive source, a reader for reading an image of the document sheet being conveyed through a reading position, and a controller for stopping the conveyance by the conveyer if a read request for a first document sheet, which is being conveyed upstream of the reading position in a conveyance direction, has not received. The controller invalidates the image read from a second document sheet which is being conveyed downstream of the first document sheet if the trailing edge of the second document sheet has not passed through the reading position at a timing when the conveyance is stopped because of the read request having not been received, and validates the image read from the second document sheet if the trailing edge of the second document sheet has passed through the reading position.

According to an embodiment, an image reading device includes a photoelectric conversion unit, a white reference plate, a rotation unit, and a control unit. The photoelectric conversion unit includes an image reading sensor which converts light from an imaging position into image data. The white reference plate has a reading range which is a white reference value. The rotation unit rotates the photoelectric conversion unit so as to come to an angle at which a plurality of portions in the reading range of the white reference plate become imaging positions. The control unit sets a white reference value using a plurality of pixels on the white reference plate which are read using the photoelectric conversion unit which is rotated using the rotation unit.

An image forming apparatus comprises an automatic document feeder (ADF); a light source configured to irradiate the document conveyed by the ADF with light; a glass member which can be switched to a first mode in which the light from the light source is transmitted and to a second mode in which the light from the light source is reflected; a signal processing circuit configured to include an image sensor for respectively receiving the reflected light of the document and the glass member, read an image of the document in the first mode and generate a signal of a white reference value based on the reflected light of the glass member in the second mode; and a shading correction circuit configured to correct, based on the signal of the white reference value, image data of the document read such that the brightness in the horizontal scanning direction is uniform.