An image-reading apparatus includes a housing having a rectangular-shaped opening on a side of a reading target, a lens portion retained or housed within the housing, and a sensor element to receive light condensed by the lens portion, the light being from the reading target. Long sides of the opening include a first layer that is flat and is disposed on the side of the reading target and a second layer that is continuous with the first layer. The long sides of the opening of the housing of the image-reading apparatus has a flat surface on the side of the reading target and an interface between the first layer and the second layer that is curved.

Provided is a light source device including a plurality of light emitting points arranged in matrix within a first cross section parallel to a first direction and a second direction. When light emitting points are projected within a second cross section parallel to first direction and a third direction perpendicular to first cross section, light emitting points have equal intervals between projections adjacent to each other. When light emitting points are projected within a third cross section parallel to second and third directions, light emitting points have equal intervals between projections adjacent to each other. An interval between light emitting points adjacent to each other in a row of matrix, an interval between light emitting points adjacent to each other in a column of matrix, an angle between row and column, an angle between column and first direction, and an angle between row and second direction are appropriately set.

An image processing apparatus includes a light source, an image sensor, and an invisible component remover. The light source emits visible component light and invisible component light to a target object. The image sensor receives reflected light from the target object to detect a visible invisible mixture image including an invisible component and a visible component and an invisible image including an invisible component. The invisible component remover, based on the visible invisible mixture image and the invisible image which have been detected, removes the invisible component from the visible invisible mixture image to generate a visible image. The invisible component remover includes a removal calculator performing a removal calculation process of an invisible component with respect to the visible invisible mixture image, and a noise reducer performing a noise reduction process on at least one of images to be input to and output from the removal calculator.

An image reading device includes a single light source that irradiates an image reading target with light, a traveling change member that changes a traveling direction of the light from the light source and irradiates the image reading target with the light at an incidence angle different from an incidence angle of the light directly applied from the light source to the image reading target, and a switching mechanism that switches traveling of the light from the light source to an optical path for directly irradiating the image reading target or an optical path for irradiating the image reading target via the traveling change member.

An image reading device includes plural light sources that irradiate an image reading target with light at different angles; and a switching mechanism that sequentially switches the light incident to the image reading target from the plural light sources during an image reading operation on the image reading target.

A document reader system configured to capture an image of a document is described. The document reader system includes a document reader having a transparent scan area, a light source, an optical filter, and an image sensor. The transparent scan area is configured to receive the document on a first side of the transparent scan area. The light source is positioned on a second side of the transparent scan area opposite the first side and is configured to emit light towards the transparent scan area. The optical filter is positioned between the light source and the transparent scan area and has a variable light transmission configured to modify light intensity of the light emitted by the light source. The image sensor positioned on the second side of the transparent scan area and configured to capture the image of the document on the first side of the transparent scan area.

An image sensor unit includes: a visible light cut filter that is arranged between a first light source and a first light guide and blocks light including visible light having wavelengths longer than those of ultraviolet light; a lens body that condenses light generated on a reading target by light radiated from the first light guide and light radiated from a second light guide; a line sensor that receives the light condensed by the lens body; and an ultraviolet light cut filter arranged between the lens body and the line sensor and blocks ultraviolet light.

An optical scanning device includes a light source, a deflector, a random number generator, a selection part, a random number assignment part and an exposure control part. The light source includes a plurality of light emitting parts arranged in a predetermined direction at fixed intervals in a sub-scanning direction. The random number assignment part is configured to assign a random number sequence to each light emitting part constituting a set of target light emitting parts as an index for specifying a timing at which a light emitting time of the set of target light emitting parts is set to a correction value different from a reference value and to update the assignment of the random number sequence at a random number update period. The random number update period coincides with a scanning period of each light emitting part constituting the set of target light emitting parts.

An outer peripheral member disposed at an outer periphery of a platen glass includes first and second reference surfaces. The first reference surface is a lower surface of an area extending along a side edge portion of the platen glass at an end in a main scanning direction. The second reference surface is located adjacent to the first reference surface in a second direction and differs in light reflectance from the first reference surface. An image processing portion determines whether outer periphery pixel data of an outer periphery area in line image data acquired successively while a scanning unit is moving, satisfies a border condition. A unit driving portion positions the scanning unit to a home position by moving the scanning unit a predetermined distance from where the scanning unit is located when it is determined that the outer periphery pixel data satisfies the border condition, and stops it.

An illumination device and an image reading device are characterized by including: a rod-shaped light guide extending in a longitudinal direction and configured to guide light entering from an exterior and emit the light as linear light from a lateral surface; a light guide holding portion having a hole into which an end surface of the light guide is inserted; a supporter supporting the light guide holding portion slidably along the longitudinal direction; and a housing supporting or housing the light guide, the light guide holding portion and the supporter, at least the supporter being fixed to the housing, a direction of sliding of the light guide holding portion being restricted to the longitudinal direction by a supporter-side concave-convex portion that is a supporter-side groove portion or a supporter-side protruding portion at least one of which is formed on the supporter along the longitudinal direction.