An image scanner is configured to: while changing a reading position by a position changer and sequentially emitting light of each of three colors in a turn-on sequence from a light source to a document, control a line sensor to read reflection light of emitted light, thereby acquiring gradation image data including gradation values of three colors for each pixel in one line; determine whether a top color shift occurs in the gradation image data at a determination position; in response to determining that the top color shift occurs at the determination position, replace gradation image data at the determination position with black image data; determine whether a bottom color shift occurs in the gradation image data at the determination position; and in response to determining that the bottom color shift occurs at the determination position, replace gradation image data at the determination position with white image data.

An image reading device includes a plurality of light-receiving pixels configured to receive reflected light; a first light-shielding member including a plurality of first openings and disposed between the plurality of light-receiving pixels and a reference surface; a second light-shielding member including a plurality of second openings and disposed between the plurality of first openings and the reference surface; and a plurality of condenser lenses disposed at a distance from the plurality of second openings. The plurality of condenser lenses, the second light-shielding member, the first light-shielding member, and the plurality of light-receiving pixels are disposed at positions at which reflected light sequentially passes through one of the condenser lenses corresponding to each light-receiving pixel, one of the second openings corresponding to the each light-receiving pixel, and one of the first openings corresponding to the each light-receiving pixel and enters the each light-receiving pixel.

An image reading device (100) includes a first glass member (52), a plurality of condensing lenses (14) provided on a first surface (52a) of the first glass member (52), a first light blocking member (12) having a plurality of first openings (32) respectively corresponding to the plurality of condensing lenses (14), a second glass member (51) having a third surface (51a) in superimposition with the first light blocking member (12), a second light blocking member (11) having a plurality of second openings (31) respectively corresponding to the plurality of first openings (32), a third glass member (53) having a fifth surface (53a) in superimposition with the second light blocking member (11), a third light blocking member (15) having a plurality of third openings (34) respectively corresponding to the plurality of second openings (31), and a sensor unit (3) having a sensor substrate (9) and a plurality of light receiving pixels (10) arrayed in a predetermined array direction on the sensor substrate (9) and respectively corresponding to the plurality of third openings (34).

An image reading device (100) includes a first glass member (52), a plurality of condensing lenses (14) provided on a first surface (52a) of the first glass member (52), a first light blocking member (12) having a plurality of first openings (32) respectively corresponding to the plurality of condensing lenses (14), a second glass member (51) having a third surface (51a) in superimposition with the first light blocking member (12), a second light blocking member (11) having a plurality of second openings (31) respectively corresponding to the plurality of first openings (32), a third glass member (53) having a fifth surface (53a) in superimposition with the second light blocking member (11), a third light blocking member (15) having a plurality of third openings (34) respectively corresponding to the plurality of second openings (31), and a sensor unit (3) having a sensor substrate (9) and a plurality of light receiving pixels (10) arrayed in a predetermined array direction on the sensor substrate (9) and respectively corresponding to the plurality of third openings (34).

In a line sensor including color filters that are periodically disposed in a light-receiving-element row, a problem called a mixture of colors occurs. A mixture of colors occurs when light that has been transmitted through a color filter differing from a color filter corresponding to a light receiving element is incident upon the light receiving element.

In a CMOS sensor 107 including a light-receiving-element row in which a plurality of photodiodes 1204 are disposed side by side in a main scanning direction and a plurality of color filters 1202 that are disposed in correspondence with the plurality of photodiodes 1204, the center of each color filter 1202 is displaced in a direction of the center of the light-receiving-element row from the center of the photodiode 1204 corresponding to the color filter.

In a line sensor including color filters that are periodically disposed in a light-receiving-element row, a problem called a mixture of colors occurs. A mixture of colors occurs when light that has been transmitted through a color filter differing from a color filter corresponding to a light receiving element is incident upon the light receiving element.

In a CMOS sensor 107 including a light-receiving-element row in which a plurality of photodiodes 1204 are disposed side by side in a main scanning direction and a plurality of color filters 1202 that are disposed in correspondence with the plurality of photodiodes 1204, the center of each color filter 1202 is displaced in a direction of the center of the light-receiving-element row from the center of the photodiode 1204 corresponding to the color filter.

The present disclosure relates to an image reading device having a highly-accurate structure that enables an easy increase in depth of field, that is, improvement in the depth of the field, without need for a change in basic characteristics of lenses. An overlap preventer (5) disposed between a lens array (1) and a sensor element array (3) to prevent overlap of images formed by lenses (2) is included. A slit section (5) that is the overlap preventer (5) includes multiple slit plates (7) arranged in a main scanning direction and extending in a sub-scanning direction to partition off a space, and the slit plates (7) are fixed to fixing plates (13).

The present disclosure relates to an image reading device having a highly-accurate structure that enables an easy increase in depth of field, that is, improvement in the depth of the field, without need for a change in basic characteristics of lenses. An overlap preventer (5) disposed between a lens array (1) and a sensor element array (3) to prevent overlap of images formed by lenses (2) is included. A slit section (5) that is the overlap preventer (5) includes multiple slit plates (7) arranged in a main scanning direction and extending in a sub-scanning direction to partition off a space, and the slit plates (7) are fixed to fixing plates (13).

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.

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.