ILLUMINATION DEVICE AND IMAGE READING DEVICE USING SAID ILLUMINATION DEVICE

摘要

Provided are: an illumination device having a configuration in which a temperature rise of a radiation member is suppressed in a limited volume to thereby maintain a temperature of an LED at a predetermined value or less and an image reading device provided with the illumination device. In order to release heat generated by the LED from a substrate on which the LED is mounted, a first heat radiation plate (43) and a second heat radiation plate (47) are provided on both sides of the LED-mounted substrate; the second heat radiation plate (47), the LED-mounted substrate, and the first heat radiation plate (43) are installed in this order on a second frame (40) that supports the LED-mounted substrate, first and second heat radiation plates (43) and (47); a fan is disposed on the first heat radiation plate (43) side; when viewing the second frame (40) in a direction perpendicular to a longitudinal direction thereof, a cross-sectional profile of the second heat radiation plate (47) has an area protruding with respect to a cross-sectional profile of the first heat radiation plate (43); and the configuration is such that wind from the fan is aggressively blown against the first and second heat radiation plates (43) and (47).

主权项

1. A linear illumination device characterized by comprising:
at least one LED used as a light source; an elongated light guide member that receives light emitted from the light source at an end portion thereof in a longitudinal direction and diffuses the light in a main scan direction; a frame made of resin; a fun for suppressing a temperature rise of the LED; an LED substrate on which the LED is mounted; a first heat radiation plate that releases heat generated from the LED from a surface of the LED substrate opposite to a surface on which the LED is mounted; and a second heat radiation plate that releases heat generated from the LED from the surface of the LED substrate on which the LED is mounted, wherein the second heat radiation plate, the LED substrate, and the first heat radiation plate are installed in this order on the frame having a support portion supporting the light guide, the LED substrate, the first and second heat radiation plates, the fan is disposed on a side of the first heat radiation plate opposite to the LED substrate, the second heat radiation plate has a cross-sectional profile having an area protruding with respect to a cross-sectional profile of the first heat radiation plate when viewing the frame from a direction perpendicular to a longitudinal direction thereof, and wind from the fan is blown against the first and second heat radiation plates.