A method and apparatus for adaptive frame rate conversion comparing the steps of calculating a plurality of motion vectors of a plurality of blocks to generate a motion judgment value; comparing the motion judgment value with a threshold value to decide a frame rate conversion approach; and executing the frame rate conversion approach. A disc transport carriage is mounted on the same guide shaft as the printhead, can be moved along this guide shaft for picking up discs in a storage area, moving a disc to a tray or support used for recording and then to a disc tray or support for printing, and moving a finished disc to a finished disc storage region. The plurality of light sources is provided in a one-to-one correspondence with the plurality of photosensitive drums. A determination of whether or not the mail piece contains any loose particulate matter can be made based on a comparison of the results for the two mass determinations. The first solution and the second solution have different polarities, and the polarity of the first solution is large than that of the second solution. Situated above the burner and plenum is a chimney, which surrounds the flame and may be a translucent or transparent material to help observers better see the flame.