An image reading apparatus includes: a reading unit configured to read an image of an original and output an image signal; and a white reference plate to be used for shading correction. The image reading apparatus drives the reading unit with maximum power consumption for a predetermined time period and thereafter drives the reading unit with reduced power consumption. The image reading apparatus causes the reading unit with reduced power consumption to read the white reference plate and generates shading data to be used for the shading correction. After that, the image reading apparatus causes the reading unit to read an original and corrects a reading result of the original based on the shading data.

An illumination device includes a light emitting unit, a light guide member, in which one end part in a longitudinal direction has a rod shape facing the light emitting unit, and is formed on a peripheral surface thereof with a light emitting part extending in the longitudinal direction, and a support member that extends along the longitudinal direction of the light guide member and supports the light guide member, wherein the support member is divided into a one side divided part and the other side divided part in the longitudinal direction of the light guide member, and a gap is provided between a support surface of the light guide member in the one side divided part and a support surface of the light guide member in the other side divided part.

An image reading device includes an image reading unit, a conductive member, a switching portion, and a switching control portion. The image reading unit includes a light emitting portion and a light receiving portion. The light emitting portion irradiates light on a document sheet that is conveyed while in contact with an upper surface of a plate-like contact member. The light receiving portion outputs image data corresponding to light reflected from the document sheet. The conductive member is provided on a lower surface of the contact member. The switching portion is switched between an on-state and an off-state so as to select between a state where the conductive member is grounded or a state where the conductive member is not grounded. The switching control portion controls switching of the switching portion.

An illuminating device capable of stably illuminating an irradiated object such as a document while suppressing light loss with a simply structure is provided. An LED array and a reflective plate are disposed sandwiching a slit (St) through which light reflected by a document MS passes and a light-guiding member is disposed on the side of the LED array. The light-guiding member includes a direct emission unit disposed between an illumination range y centered on a document reading position and the LED array and an indirect emission unit disposed between the reflective plate and the LED array, a light incidence face of the direct emission unit and a light incidence face of the indirect emission unit are disposed at mutually different position around the LED array, and the LED array is disposed on a side of an interior angle formed by the light incidence faces.

Provided is the light guiding member including an incident surface, an exit surface extending in a first direction, a light guiding surface opposed to the exit surface, and being configured to guide light entering the incident surface to the exit surface, a side surface connecting the exit surface and the light guiding surface, and a held portion formed on the side surface. The light guiding surface includes a plurality of deflection portions arrayed in the first direction. At least one of a density or a depth of each of the plurality of deflection portions differs between a first region on the light guiding surface, which corresponds to a region at which the held portion is present in the first direction, and a second region on the light guiding surface adjacent to each of both sides of the first region in the first direction.

An illumination device includes a light emitting unit, a light guide member, in which one end part in a longitudinal direction has a rod shape facing the light emitting unit, and is formed on a peripheral surface thereof with a light emitting part extending in the longitudinal direction, and a support member that extends along the longitudinal direction of the light guide member and supports the light guide member, wherein the support member is divided into a one side divided part and the other side divided part in the longitudinal direction of the light guide member, and a gap is provided between a support surface of the light guide member in the one side divided part and a support surface of the light guide member in the other side divided part.

An illumination device includes a light emitting unit, a light guide member, and a support member. The light guide member has a flat plate part that extends in the longitudinal direction and a light guide body, and is molded such that a sectional shape vertical to the longitudinal direction is a hat shape. The support member has a pair of end support parts that support both end parts in the longitudinal direction of the light guide member and a flat plate part-support part that supports a surface of the flat plate part of the light guide member, which is opposite to a side of the light guide body. A support surface of the flat plate part-support part abuts the surface in an entire area in the longitudinal direction of the surface of the light guide member.

An image reading apparatus includes an illumination unit that illuminates light on an image surface of a sheet, and a photoelectric conversion element that converts reflected light from the sheet illuminated by the illumination unit into an electric signal. The illumination unit includes a circuit board including a light emitting element, and a light guide that guides light, emitted from the light emitting element, to a sheet read surface. In the image reading apparatus, the light guide includes a positioning surface that abuts against a first surface of the circuit board and that performs positioning of the light guide and the circuit board, and a pressing portion that abuts against a second surface of the circuit board on an opposite side of the first surface and that presses the circuit board against the positioning surface.

An image reading apparatus includes an illumination unit that illuminates light on an image surface of a sheet, and a photoelectric conversion element that converts reflected light from the sheet illuminated by the illumination unit into an electric signal. The illumination unit includes a circuit board including a light emitting element, and a light guide that guides light, emitted from the light emitting element, to a sheet read surface. In the image reading apparatus, the light guide includes a positioning surface that abuts against a first surface of the circuit board and that performs positioning of the light guide and the circuit board, and a pressing portion that abuts against a second surface of the circuit board on an opposite side of the first surface and that presses the circuit board against the positioning surface.

An image sensor unit includes a light condenser that collects light from a reading target object; an image sensor that receives light and converts the light into an electric signal; an elongated housing that houses the light condenser and the image sensor; and an elongated rigid member attached to a side surface extending in the elongated direction of the housing. The side surface of the housing is provided with an attachment protrusion. The rigid member is provided with an attachment hole that penetrates from a surface facing the side surface of the housing to a non-facing surface on the opposite side, and the non-facing surface of the rigid member is provided with a concave. The attachment protrusion is inserted into the attachment hole, and a part of the attachment protrusion is fit into the concave.