An image reading apparatus and an image reading method are provided by which a top face image and a back face image of a document can both have an improved reading accuracy while simplifying a circuit configuration and providing a higher processing speed. More particularly, the invention teaches the usage of coiled springs in conjunction with polymeric materials or metals such as titanium or steel, to help absorb and dissipate forces of humans and other objects coming in contact with said flat surfaces. A piston extends into the housing. The first cooling air flow by-passes the combustor and is cooled in the heat exchanger.