MAGNET ROLL FOR MAGNETIC BRUSH DEVELOPMENT

PROBLEM TO BE SOLVED: To control the recovery and the peeling of developer and to improve image quality by providing a notched part on the magnetic field forming piece at parts where magnetic waveforms having the same pole are adjacent. SOLUTION: The respective magnetic field forming pieces 3 and 4 are stuck to the outer periphery of a columnar shaft 2, so that the cylindrical magnet roll is formed. By providing the notched part 4a on the piece 4 at the parts S3 and S2 where the magnetic waveforms having the same pole are adjacent, the specified angle of waveform shown by the magnetic field is controlled, space between S3 and S2 is widened, and magnetic force between them is reduced, so that the old developer is peeled at this part. When the magnetic waveforms other than the waveform having the same pole are adjacent, the specified angle of the waveform shown by the magnetic field is controlled if the notched part is provided on the piece 3. By changing the size or the depth of the notched part 4a according to the orientation position of the piece 4, the specified angle of the waveform shown by the magnetic field is controlled.