In recording on a back side of a sheet in duplex recording, an overlapping pixel where both a pixel in back-side image data and a pixel opposed thereto in front-side image data has a gray level value larger than zero is retrieved from the front-side and back-side image data. The method also includes forming a plurality of insulator layers over the device. These two components are manufactured in separate tracks, which consist of jigs, whereby each of these rotates stepwise in a rotating table. The pixel area structures of the pickup device are uniform, the wirings are uniform, and the vertical and horizontal driving systems and an output system are uniform.