An illumination device and an image reading device are characterized by including: a rod-shaped light guide extending in a longitudinal direction and configured to guide light entering from an exterior and emit the light as linear light from a lateral surface; a light guide holding portion having a hole into which an end surface of the light guide is inserted; a supporter supporting the light guide holding portion slidably along the longitudinal direction; and a housing supporting or housing the light guide, the light guide holding portion and the supporter, at least the supporter being fixed to the housing, a direction of sliding of the light guide holding portion being restricted to the longitudinal direction by a supporter-side concave-convex portion that is a supporter-side groove portion or a supporter-side protruding portion at least one of which is formed on the supporter along the longitudinal direction.

An illumination device and an image reading device are characterized by including: a rod-shaped light guide extending in a longitudinal direction and configured to guide light entering from an exterior and emit the light as linear light from a lateral surface; a light guide holding portion having a hole into which an end surface of the light guide is inserted; a supporter supporting the light guide holding portion slidably along the longitudinal direction; and a housing supporting or housing the light guide, the light guide holding portion and the supporter, at least the supporter being fixed to the housing, a direction of sliding of the light guide holding portion being restricted to the longitudinal direction by a supporter-side concave-convex portion that is a supporter-side groove portion or a supporter-side protruding portion at least one of which is formed on the supporter along the longitudinal direction.

An image reading device includes (i) light guides extending in a main scanning direction and configured to emit light from a light source toward a reading target moving relatively in a sub-scanning direction, the light from the light source being projected into end surfaces of the light guides in the main scanning direction, (ii) an optical filter arranged between the light source and the end surfaces of the light guides and configured to block or attenuate light having a specific wavelength from the light from the light source, (iii) a lens body to focus reflected light reflected by the reading target onto a light receiver to convert the reflected light into an electrical signal, and (iv) a lens holder. The lens holder includes a first positioner for positioning the light guides and a second positioner for positioning the optical filter.

An image reading device includes light guides (5, 6) that emit light to an object to be read, a lens body (8) that condenses reflected light, a light receiver (13) that receives the reflected light, a sensor board (24) on which is mounted the light receiver (13), a lens holder (11), and a housing (9) that houses or holds these components. The lens holder (11) includes a holder bottom (11g), light guide positioners (11a, 11b) and lens body holders (11e, 11f). In the lens holder (11), the lens body (8) is attached between the lens body holders (11e, 11f), the sensor board (24) is attached to the holder bottom (11g) such that the light receiver (13) aligns with an optical axis of the lens body (8), and the light guides (5, 6) are attached to the light guide positioners (11a, 11b). A surface of each light guide positioner (11a, 11b) that faces the corresponding light guide (5, 6) to be attached has at least a portion having a same shape a s a shape of a surface of the light guide.

An image reading device includes a glass having a document reading surface along which a document moves; an image reading unit movable in a sub-scanning direction and including a light emitting portion that emits light to illuminate the document with the light and a light receiving portion that receives the light reflected by the document, the image reading unit reading the document that moves along the document reading surface at a predetermined document reading position; and a light emission control unit that causes the light emitting portion to emit the light so that the light enters the glass through a side surface that crosses the document reading surface in an operation different from an operation in which the image reading unit reads the document.

An image reading device includes (i) light guides extending in a main scanning direction and configured to emit light from a light source toward a reading target moving relatively in a sub-scanning direction, the light from the light source being projected into end surfaces of the light guides in the main scanning direction, (ii) an optical filter arranged between the light source and the end surfaces of the light guides and configured to block or attenuate light having a specific wavelength from the light from the light source, (iii) a lens body to focus reflected light reflected by the reading target onto a light receiver to convert the reflected light into an electrical signal, and (iv) a lens holder. The lens holder includes a first positioner for positioning the light guides and a second positioner for positioning the optical filter.

An image reading apparatus includes an illumination unit that illuminates light on an image surface of a sheet, and a photoelectric conversion element that converts reflected light from the sheet illuminated by the illumination unit into an electric signal. The illumination unit includes a circuit board including a light emitting element, and a light guide that guides light, emitted from the light emitting element, to a sheet read surface. In the image reading apparatus, the light guide includes a positioning surface that abuts against a first surface of the circuit board and that performs positioning of the light guide and the circuit board, and a pressing portion that abuts against a second surface of the circuit board on an opposite side of the first surface and that presses the circuit board against the positioning surface.

An image reading device includes light guides (5, 6) that emit light to an object to be read, a lens body (8) that condenses reflected light, a light receiver (13) that receives the reflected light, a sensor board (24) on which is mounted the light receiver (13), a lens holder (11), and a housing (9) that houses or holds these components. The lens holder (11) includes a holder bottom (11g), light guide positioners (11a, 11b) and lens body holders (11e, 11f). In the lens holder (11), the lens body (8) is attached between the lens body holders (11e, 11f), the sensor board (24) is attached to the holder bottom (11g) such that the light receiver (13) aligns with an optical axis of the lens body (8), and the light guides (5, 6) are attached to the light guide positioners (11a, 11b). A surface of each light guide positioner (11a, 11b) that faces the corresponding light guide (5, 6) to be attached has at least a portion having a same shape a s a shape of a surface of the light guide.

An image reading device includes a glass having a document reading surface along which a document moves; an image reading unit movable in a sub-scanning direction and including a light emitting portion that emits light to illuminate the document with the light and a light receiving portion that receives the light reflected by the document, the image reading unit reading the document that moves along the document reading surface at a predetermined document reading position; and a light emission control unit that causes the light emitting portion to emit the light so that the light enters the glass through a side surface that crosses the document reading surface in an operation different from an operation in which the image reading unit reads the document.

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.