An image reading apparatus includes an original illuminator; a reflector for reflecting light reflected by the original; a reading portion for reading the light reflected by the reflector; a holding member holding the reflection member; a first bonding portion connecting the holding member and one end portion of the reflector in a direction along a reflecting surface of the reflection member; and a second bonding portion connecting the holding member and the other end portion of the reflector in the direction along the reflecting surface of the reflection member. The second bonding portion has a hardness less than that of the first bonding portion.

An image reading device includes reading devices arranged in a main scanning direction perpendicular to a sub-scanning direction, position reference members each including a reference pattern for correcting relative positions of pixels in each of the reading devices or relative positions of the reading devices, and circuitry. The reference members move in the sub-scanning direction relative to the reading devices, and include first reference members for correcting the relative positions of the reading devices and second reference members for correcting the relative positions of the pixels in each of the reading devices. While switching between the first reference members and the second reference members, the circuitry calculates a correction value for a deviation of the pixels in each of the reading devices and a correction value for a deviation of the reading devices based on a result of reading of the reference members.

An image reading device includes reading devices arranged in a main scanning direction perpendicular to a sub-scanning direction, position reference members each including a reference pattern for correcting relative positions of pixels in each of the reading devices or relative positions of the reading devices, and circuitry. The reference members move in the sub-scanning direction relative to the reading devices, and include first reference members for correcting the relative positions of the reading devices and second reference members for correcting the relative positions of the pixels in each of the reading devices. While switching between the first reference members and the second reference members, the circuitry calculates a correction value for a deviation of the pixels in each of the reading devices and a correction value for a deviation of the reading devices based on a result of reading of the reference members.

Thermal variations on an optical scanning device can affect measurements made by that device. Various ways are presented here to control the temperature of a device and compensate for temperature variations of the device.

A scanning path of light includes a synchronization detection area A where a synchronization detection sensor 47 detects scanning light and an image writing area B where writing of the image data to a photosensitive drum 11 is performed by the scanning light, and a light amount change unit 100 is configured to reduce a change amount of a light amount in the synchronization detection area A as compared with the image writing area B.

An exposure device includes a plate member, a plurality of light-emitting elements, and an optical system. The plate member extends in both a first direction and a second direction intersecting with the first direction. The light-emitting elements are disposed on the plate member side by side in the first direction. The light-emitting elements emit respective light beams in the second direction. The optical system is disposed on the plate member and faces the light-emitting elements in the second direction. The optical system performs imaging of the light beams emitted by the respective light-emitting elements.

A lens unit according to one or more embodiments includes a lens plate member including a plurality of lenses arranged in a first direction; and a light block member provided facing the lens plate member and including a plurality of opening portions arranged in the first direction, the opening portions being provided in one-to-one correspondence with the lenses. A first positioning portion is formed at a first position in first direction of each of the lens plate member and the light block member. The first positioning portion of the lens plate member and the first positioning portion of the light block member align with each other and continuously extend in a second direction along an optical axis direction of the lenses.

An image reading device (1) includes a board (24) including a plurality of imaging elements (23) arranged along a scanning direction, and a housing (13) including (i) a plurality of optical components that are arranged along the scanning direction and (ii) a plurality of housing components (13a, 13b) that are arranged along the scanning direction. Each of the plurality of optical components focuses light reflected by a reading target onto a corresponding imaging element (23), and each of the plurality of housing components holds at least one optical component. The plurality of housing components (13a, 13b) are arranged to have a clearance therebetween and each of the plurality of housing components (13a, 13b) is fixed to the board (24) at a position to transmit light through the optical components to focus onto the corresponding imaging element (23).

An image data transfer control device includes a first interface, a first and a second memory, a processor, and a second interface. The first interface acquires image data transferred in predetermined units. The first memory stores inclination correction data corresponding to the inclination of a print head, and correction position data indicating a correction position included in at least one divided image line among the predetermined number of divided image lines including each divided image line group. The second memory stores correction target image data at the correction position. The processor selects each divided image line group based on the inclination correction data, and specifies first and second correction target image data. The second interface outputs the second divided image line group including the first correction target image data instead of the second correction target image data.

A scanning path of light includes a synchronization detection area A where a synchronization detection sensor 47 detects scanning light and an image writing area B where writing of the image data to a photosensitive drum 11 is performed by the scanning light, and a light amount change unit 100 is configured to reduce a change amount of a light amount in the synchronization detection area A as compared with the image writing area B.