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.

A first image reading chip for reading an image of a first surface of a medium includes a first pixel portion that outputs a first pixel signal, a first output circuit that outputs a signal based on the first pixel signal, and a first output selection unit that selects a first drive capability as a drive capability of the first output circuit, and a second image reading chip for reading an image of a second surface of a medium includes a second pixel portion that outputs a second pixel signal, a second output circuit that outputs a signal based on the second pixel signal, and a second output selection unit that selects a second drive capability as a drive capability of the second output circuit.

An image reading apparatus includes a light source, a light receiving unit, and an optical system. The light receiving unit includes a plurality of light receiving elements. The optical system includes a plurality of optical components for splitting the light reflected from the object to be read, and guiding the split light to each of the plurality of light receiving elements. The plurality of optical components include a splitting component that splits the light reflected from the object to be read in a direction corresponding to a main direction, and a common component provided with a common portion. The common portion has an optically acting area causing a common effect on the tight split by the splitting component. A cross sectional shape of the optically acting area orthogonal to a direction corresponding to the main direction is the same shape along the direction corresponding to the main direction.

A light receiving unit including: a sensor board assembly on which plural sensor tips are arrayed in a line in a longitudinal direction of the sensor board and mounted on the sensor board; and a sensor plate on which plural of the sensor board assemblies are arrayed and mounted in a line in the longitudinal direction. The sensor chips include plural pixels formed in a line in the longitudinal direction. At longitudinal ends of the sensor board assembly, the sensor chips protrude outward in the longitudinal direction from the longitudinal ends. Between the facing sensor chips of the adjacent sensor board assemblies, the facing sensor chips mounted at the longitudinal ends, the ends of the facing sensor chips are spaced at a predetermined interval. The sensor board includes convex portions, at the longitudinal ends, protruding in the longitudinal direction. The sensor chips are mounted at the convex portion.

There is provided a method of manufacturing an image sensor unit, the image sensor unit including: a linear light source that illuminates a document along a main scanning direction; a rod lens array that includes a plurality of rod lenses arranged in the main scanning direction and condenses a light reflected from the document; and a linear image sensor that receives a light condensed by the rod lens array. When a rod lens having an optically discontinuous portion on a surface and/or interior of the rod lens is included, the rod lens array is arranged such that the optically discontinuous portion is not located toward the document.