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.

A light irradiation device includes a light source, a light guide member, and a holding member. The light guide member includes an incident surface, an exit surface, and a held surface. The incident surface has an elongated shape in a main scanning direction and faces a light emitting surface of the light source. The light guide member includes a securing structure in each of both end portions in the main scanning direction, which are out of a light guide area of the light guide member. The securing structure in one end portion is an engagement lug structure protruding to penetrate into a through-hole of the holding member, including a lug on a leading end, and engaging the holding member. The securing structure on another end portion is a fastening structure having a fastening hole penetrated with a fastening member and being secured to the holding member with the fastening member.

An illuminating device (210) according to an embodiment of the invention included in an image reading apparatus (100) and an image forming apparatus (D) includes light source portions (211a1), (211b1), (211a2) and (211b2), light-guiding members (213a) and (213b) for illuminating an illumination target (G) from an elongated light emitting face (M) that extends in a longitudinal direction (Y), by guiding light from the light source portions, and holding members (216a) and (216b) for holding the light-guiding members. The holding members include holding portions (2161a) and (2161b) for removably holding the light-guiding members, and tilted portions (2162a) and (2162b) that reflect light emitted from the light emitting face (M), the tilted portions extending from a front end on the light emitting face (M) side of the holding portions, obliquely widening with increasing distance from the light-guiding members.

An illuminating device (210) according to an embodiment of the invention included in an image reading apparatus (100) and an image forming apparatus (D) includes light source portions (211a1), (211b1), (211a2) and (211b2), light-guiding members (213a) and (213b) for illuminating an illumination target (G) from an elongated light emitting face (M) that extends in a longitudinal direction (Y), by guiding light from the light source portions, and holding members (216a) and (216b) for holding the light-guiding members. The holding members include holding portions (2161a) and (2161b) for removably holding the light-guiding members, and tilted portions (2162a) and (2162b) that reflect light emitted from the light emitting face (M), the tilted portions extending from a front end on the light emitting face (M) side of the holding portions, obliquely widening with increasing distance from the light-guiding members.

A light guide body that extends in a rod shape and guides light incident from an end surface thereof to emit the light from a circumferential surface thereof, the light guide body having a shape such that according to an angle of a circumferential direction around the light guide body, an amount of emitting light in a direction of the angle is different. Additionally, a static elimination device and an image forming apparatus include the light guide body.

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.

There is provided a light guide body that extends in a rod shape and guides light incident from an end surface thereof to emit the light from a circumferential surface thereof, the light guide body having a shape such that according to an angle of a circumferential direction around the light guide body, an amount of emitting light in a directoin of the angle is different. There is also provided a static elimination device and an image forming apparatus which include the light guide body.

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.

A light guide includes a plurality of boss portions. A round hole portion is provided near the center of a base member for fixing the light guide, and slit portions are provided on both ends thereof. The round hole portion supports one boss portion in both the longitudinal direction and the lateral direction of the light guide. The slit portions support boss portions in the lateral direction of the light guide, but are free in the longitudinal direction of the light guide. That is, the center of the light guide is fixed from both directions, and thus both ends of the light guides can expand away in the longitudinal direction. This cuts the influence of expansion by half.

A light guide includes a plurality of boss portions. A round hole portion is provided near the center of a base member for fixing the light guide, and slit portions are provided on both ends thereof. The round hole portion supports one boss portion in both the longitudinal direction and the lateral direction of the light guide. The slit portions support boss portions in the lateral direction of the light guide, but are free in the longitudinal direction of the light guide. That is, the center of the light guide is fixed from both directions, and thus both ends of the light guides can expand away in the longitudinal direction. This cuts the influence of expansion by half.