Book printer including support for accommodating bound portion

A printer prints upon a book having a plurality of pages bound at a binding edge (1). The book is opened, placed on a supporting surface (16) and fed in a feed direction parallel to the binding edge. A supporting shaft (13) extends parallel to the supporting surface. A channel (17) receives the binding edge in the middle of supporting surface and extends perpendicular to the supporting shaft thereby dividing the supporting surface into a first area and a second area. A first supporting frame (14) is pivotally supported on the supporting shaft over the first area. A first rotating shaft (25) is rotatably supported by the first supporting frame parallel with the supporting shaft. A first upper feeding roller (26, 27) is fixed on the first rotating shaft and forced to engage any page placed upon the first area. A second supporting frame (15) is pivotally supported on the supporting shaft over the second area. A second rotating shaft (30) is rotatably supported by the second supporting frame in parallel with the supporting shaft. A second upper feed roller (31,32) is fixed on the second rotating shaft and forced to engage any page placed upon the second area. A universal joint (33) couples the first rotating shaft to the second rotating shaft. A driving means is coupled to one of the first and second rotating shafts.