US Patent 7311367 Apparatus and methods for sensing and clamping discs

Apparatus and methods are provided. At least one clamping finger of a movable tray of a compact disc printer pushes against an outer periphery of a compact disc disposed on a surface of the tray to clamp the compact disc between the clamping finger and a pair of studs that protrude from the surface of the tray and engage a periphery of a hole passing through a center of the compact disc. A carriage of the printer for moving an ink jet cartridge attached thereto across the compact disc to deposit an image on the compact disc may include a sensor. The sensor can be used to determine the presence of a compact disc on the tray, whether the compact disc is clamped to the tray, and a dimension of the compact disc, and to perform a calibration method.