An image reading device includes a lens array including lenses arranged in a main scanning direction and forming an erect unmagnified optical system to converge light from a reading target, a holder holding the lens array, a light receiver to receive the light converged by the lenses, and slit units. Each slit unit includes three or more light shielding plates each separating an optical path of one lens from an optical path of another lens between the lens array and the light receiver, and side plates disposed on two sides of the light shielding plates in a direction intersecting the main scanning direction and connecting two adjacent light shielding plates. The slit units are arranged in the main scanning direction, and each two adjacent slit units are arranged with a space therebetween for one optical path of one lens.

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 optical PH includes: a plurality of current-driven light emitting elements that are arranged in a line-shaped region; a controller that outputs a control voltage instructing an amount of a drive current to be supplied to each of the light emitting elements; and a plurality of drivers that correspond one-to-one with the light emitting elements, and each supply the drive current to a corresponding one of the light emitting elements, wherein the drivers each operate as one of: a high-voltage referring driver that supplies the drive current according to a voltage difference between the control voltage and a reference voltage higher than the control voltage; and a low-voltage referring driver that supplies the drive current according to a voltage difference between the control voltage and a reference voltage lower than the control voltage.

An image reading apparatus includes a light source that emits light in a main scanning direction to a subject to be read, a light receiving unit that receives light reflected by the subject to be read, and an optical system that images the light reflected by the subject to be read and guides the light to the light receiving unit. The optical system includes a reflector mirror that reflects the light reflected by the subject to be read, and an optical element that is disposed adjacent to the reflector mirror and images the light reflected by the subject to be read. The optical element is held by the reflector mirror.

A scanner having: a first mirror having multiple concavities configured to reflect light from a document; a sensor configured to sense light reflected by a concavity of the first mirror; and a wall disposed to the first mirror and protruding from between the multiple concavities.

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 optical print head, including: an elongated substrate having a line-shaped region in which light-emitting elements are arranged; an optical member condensing light from the light-emitting elements onto an irradiation target; a holding member holding the optical member; a base member holding the substrate and the holding member; an integrated circuit mounted in a first region in proximity of an end in a longitudinal direction of the substrate on a first surface of the substrate facing the base member, heat being generated in the integrated circuit during optical writing; and a thermally conductive member between the integrated circuit and the base member. In the optical print head, the holding member has a support portion contacting the substrate in a second region at a position differing from the first region in plan view on a second surface of the substrate not facing the base member.

In a line sensor including color filters periodically disposed in a light-receiving-element row, a mixture of colors problem 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. To prevent the mixture of colors from occurring, 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, other than the center color filter that corresponds to the center photodiode of the light-receiving-element row, is displaced in a direction toward 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 periodically disposed in a light-receiving-element row, a mixture of colors problem 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. To prevent the mixture of colors from occurring, 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, other than the center color filter that corresponds to the center photodiode of the light-receiving-element row, is displaced in a direction toward the center of the light-receiving-element row from the center of the photodiode 1204 corresponding to the color filter.

A photoelectric conversion element includes a plurality of pixels to receive light; and a signal processor to process a signal of the pixels. The signal processor includes: a first element, being a transistor, having a first effective channel width through which a current can effectively pass through in the first element; and a second element, being a transistor, having a second effective channel width through which a current can effectively pass through in the second element. The first effective channel width of the first element is larger than the second effective channel width of the second element.