An image reading apparatus, includes an image sensor, a drive mechanism configured to cause the image sensor to move in a first direction and a second direction opposite to the first direction, a reference plate, and a control unit configured to execute a first reading method of detecting a first reference position by driving the image sensor in the first direction and reading the reference plate, thereafter reading a document by driving the image sensor in the first direction, and a second reading method of detecting a second reference position by driving the image sensor in the second direction and reading the reference plate, and thereafter reading a document by driving the image sensor in the second direction.

There is provided with a lighting apparatus. An elongated first light emission unit and an elongated second light emission unit each extend in a longer side direction and a shorter side direction. The first light emission unit and the second light emission unit have respective end portions in the longer side direction that are connected to each other via a restricting mechanism having a shape that restricts relative movement of the first and second light emission units in the shorter side direction.

In one example, a document scanner has a fixed-position scan bar and a built-in translatable calibration target. The scan bar has a linear array of imaging elements aimed in an imaging direction. The calibration target is spaced apart from and parallel to the linear array, and has a planar surface orthogonal to the imaging direction spanning the length of the linear array. The target is translatable during a calibration in a direction in a plane of the surface.

In one example, a document scanner has a fixed-position scan bar and a built-in translatable calibration target. The scan bar has a linear array of imaging elements aimed in an imaging direction. The calibration target is spaced apart from and parallel to the linear array, and has a planar surface orthogonal to the imaging direction spanning the length of the linear array. The target is translatable during a calibration in a direction in a plane of the surface.

A line sensor apparatus comprises a rod lens array in which a plurality of rod lenses are arrayed in a first direction, a line sensor substrate including a line sensor which receives light from the rod lens array, a pair of inner supporting members configured to support the line sensor substrate, a transmitter substrate including a transmitter which transfers data based on the light detected by the line sensor, and an outer supporting member configured to support the pair of inner supporting members and the transmitter substrate, wherein the pair of inner supporting members are arranged on two side surfaces of the rod lens array in a second direction perpendicular to the first direction.

A light scanning apparatus including: a first holder attached to a housing and configured to hold a first laser light source; a second holder attached to the housing and configured to hold a second laser light source; and a lens to which the laser lights are first incident, wherein the first holder and the second holder are attached to the housing in mutually different positions in a rotation axis direction of a rotary polygon mirror and in an optical axis direction of the lens, so that a first incident light path from the first laser light source to the rotary polygon mirror is placed between a second incident light path from the second laser light source to the rotary polygon mirror and the lens, and the first holder and the second holder overlap one another in the rotation axis direction.

In an image reading device, a controller is configured to perform: calculating a ratio between first and second reference data as evaluation data; designating a target light receiving element from a plurality of light receiving elements one by one sequentially; calculating average evaluation data of the target light receiving element by averaging the evaluation data of a second number of light receiving elements located at positions apart every predetermined distance equal to a length of a first number of consecutively arranged light receiving elements; setting an evaluation range of the target light receiving element by adding/subtracting a predetermined value to/from the average evaluation data; determining whether the evaluation data falls within the evaluation range; in response to determining that the evaluation data is out of the evaluation range, revising the second reference data of the target light receiving element; and generating correction data using the second reference data after revision.

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.

An image sensor unit includes a light condenser that collects light from an object to be read, an image sensor that receives the light collected by the light condenser and outputs an image, and a housing that houses the light condenser and the image sensor. The housing includes a plurality of spacer attachment portions to which a first spacer that keeps a distance between the housing and a mount member can be detachably attached and for which distances between the housing and the mount member in a state where the attached first spacer abuts against the mount member differ from each other.

An image sensor unit includes: multiple first light guides that shape light emitted by light sources into a line and emit linear light elongated in longitudinal direction to an object to be read (P); multiple holding members that hold each of the first light guides on a frame; and an image sensor that detects light from the object to be read (P). The multiple first light guides are parallel, and in a range in which the image sensor detects the light from the object to be read (P) in the longitudinal direction of the first light guides, center positions in the main-scan direction of the multiple holding members that hold one first light guide of the multiple light guides and center positions in the main-scan direction of the multiple holding members that hold another light guide different from the one first light guide deviate from each other.