Patent attributes
An image reading apparatus includes a transparent original table for placing a transmitting original thereon, an image reading unit for reading an image of the transmitting original through the transparent original table, and a transmitting original holder having a through-hole for positioning the transmitting original relative to the transparent original table. In addition, an illuminating unit is provided for pressing the transmitting original positioned by the through-hole of the original holder, and includes a plane light source for illuminating the transmitting original, a fitting portion for fitting in the through-hole, and a protruding portion protruding toward a direction along the surface of the transmitting original from a surface of the illumination unit. The protruding portion contacts with an upper surface of the transmitting original holder when the fitting portion fits and thus the transmitting original is pressed.