An image reading apparatus includes: a contact glass provided at an upper surface of a main body of the apparatus to set a manuscript thereon, an image sensor being positioned below the contact glass and having a reading surface on contact glass side for reading an image from the manuscript on the contact glass, a carriage supporting the image sensor accommodated in a sensor container formed to have a recess open to the contact glass side, a rail member slidably supporting the carriage, and a biasing member biasing the image sensor to the contact glass side via a biased portion adjacent to the reading surface of the image sensor. An upper end of the biasing member is positioned below the contact glass and above the lower surface of the image sensor.

An illuminating device capable of stably illuminating an irradiated object such as a document while suppressing light loss with a simply structure is provided. An LED array and a reflective plate are disposed sandwiching a slit (St) through which light reflected by a document MS passes and a light-guiding member is disposed on the side of the LED array. The light-guiding member includes a direct emission unit disposed between an illumination range y centered on a document reading position and the LED array and an indirect emission unit disposed between the reflective plate and the LED array, a light incidence face of the direct emission unit and a light incidence face of the indirect emission unit are disposed at mutually different position around the LED array, and the LED array is disposed on a side of an interior angle formed by the light incidence faces.

In an image reader, a controller control, during a period from a timing when a detector detects an open state of a cover to a timing when the detector detects a closed state of the cover, a document detector to detect whether a document sheet is present or absent every time a prescribed time period is elapsed, and stores in a memory each set of first data indicating absence or presence of the document sheet. The controller determines a first size of the document sheet in a main scanning direction. The controller determines a second size of the document sheet in a sub scanning direction on the basis of the sets of first data. The controller determines a reading range on the basis of the first and second sizes. The reading section reads the determined reading range on the line-to-line basis to obtain an image of the document sheet.

An image reading apparatus includes a guide member whose part in sliding-contact with a light-emitting portion is formed of synthetic resin. A control portion is configured to execute a control of changing a turn position among a plurality of positions including a first position and a second position downstream in an image reading direction of the first position in case that the light-emitting portion irradiates the first size sheet with light to read an image thereof.

An image reading apparatus includes a light emitting element, a luminance calculating unit, a light amount setting unit, and a storing unit. The light amount setting unit, in each line period, causes the light emitting element to emit a light with gradually changing a reference light amount from a reference light amount set as a default value from among a plurality of reference light amounts stored in the storing unit, identifies a reference light amount so that the luminance calculated by the luminance calculating unit is within a predetermined range, sets the identified reference light amount as a default value for the next line period, and causes the storing unit to store that reference light amount.

A reading apparatus includes a main body that includes an original document plate and a reading portion configured to read an image from the original document, and an operation portion that is attached in the original document plate. The operation portion includes: a front face casing portion; and a rear face casing portion that is engaged with the front face casing portion at an operation surface. An upper end portion of the operation portion is as high as the original document plate or higher than the original document plate, and in an engaging portion of the front face casing portion and the rear face casing portion at the upper end portion, an upper edge of the front face casing portion has a shorter distance to the lower end portion of the operation portion than the upper edge of the rear face casing portion.

A document backing extending in a plane is resiliently biased in a direction substantially parallel to the plane.

An image reading apparatus includes a medium reading unit that extends in a main scanning direction and reads an image of a medium while moving in a sub-scanning direction which is a direction crossing the main scanning direction; a signal transmission cable that is a flexible cable having a curved section and connected to the medium reading unit and that deforms following a movement of the medium reading unit; a power supply that supplies power to the medium reading unit; and a housing that accommodates the medium reading unit and the power supply. At least a portion of an insertion/extraction space for inserting/extracting a plug of a power cable from outside the housing to the power supply and at least a portion of an area where the signal transmission cable deforms following the movement of the medium reading unit overlap in a height direction of the medium reading unit.

An image reading apparatus includes: a contact glass provided at an upper surface of a main body of the apparatus to set a manuscript thereon, an image sensor being positioned below the contact glass and having a reading surface on contact glass side for reading an image from the manuscript on the contact glass, a carriage supporting the image sensor accommodated in a sensor container formed to have a recess open to the contact glass side, a rail member slidably supporting the carriage, and a biasing member biasing the image sensor to the contact glass side via a biased portion adjacent to the reading surface of the image sensor. An upper end of the biasing member is positioned below the contact glass and above the lower surface of the image sensor.

An illuminating device capable of stably illuminating an irradiated object such as a document while suppressing light loss with a simply structure is provided. An LED array and a reflective plate are disposed sandwiching a slit (St) through which light reflected by a document MS passes and a light-guiding member is disposed on the side of the LED array. The light-guiding member includes a direct emission unit disposed between an illumination range y centered on a document reading position and the LED array and an indirect emission unit disposed between the reflective plate and the LED array, a light incidence face of the direct emission unit and a light incidence face of the indirect emission unit are disposed at mutually different position around the LED array, and the LED array is disposed on a side of an interior angle formed by the light incidence faces.