Image reading unit and image reading apparatus using the same

An image reading unit for reading an image on a document, comprising:

• a light source for irradiating light to a document,
• a plurality of mirrors for reflecting the light irradiated from the light source and reflected at the document,
• a lens for focusing the light reflected by the mirrors,
• an image sensor for receiving the light from the lens and converting the same into an electric signal,
• a heat dissipating member for dissipating heat of the image sensor,
• a circuit board having an outer side and an inner side, said image sensor and the heat dissipating member being attached to the inner side,
• a shield member disposed on the outer side of the circuit board to be located at an outermost side of the image reading unit for reducing a noise relative to at least one of the image sensor and the circuit board,
• a heat conductive member situated between the heat dissipating member and the shield member to transfer the heat from the heat dissipating member to the shield member, said heat conductive member integrally uniting the circuit board, image sensor, heat dissipating member and shield member together as one sensor unit, and
• a frame for integrally supporting the light source, the mirrors, the lens and the one sensor unit,
• wherein said shield member includes a center portion to which the circuit board, the image sensor and the heat dissipating member are attached through the heat conductive member, and bent portions located on two lateral sides of the center portion and extending toward the image reading unit, said bent portions being adjustably connected to the frame so that said one sensor unit can be adjustably positioned along a light path entering into the image sensor.