| 摘要 |
PURPOSE:To obtain a magnet-roll which has a magnetizing wave-form by which an efficient development property can be obtained and whose weight can be reduced by a method wherein a sectional shape of a part of a circumference of a permanent magnet is a circular arc coaxial with a non-magnetic sleeve and poles are provided to the circular arc part and the plane part of the circumference of the permanent magnet. CONSTITUTION:A semi-cylindrical permanent magnet 1 is used as a permanent magnet member and fitted to a shaft 2. One pole (N-pole) is provided to a circular arc part of a circumference of the permanent magnet 1 and one pole (S- pole) is provided to each of the plane parts 4 and 4' of the circumference. With a pole arrangement like this, a magnetized state expressed by broken lines is obtained. As the flux in the magnet flows from the N-pole of the circular arc part to the S-poles of the plane parts 4 and 4', a large flow of flux whose expanse is more than the angle theta (in the Figure, theta=180 deg.) between the plane parts 4 and 4' can be formed. In this example, the angle is 180 deg. because a semi-cylindrical magnet is applied as the permanent magnet 1, but the angle can be determined optionally by changing the shape of the permanent magnet 1 corresponding to the construction of a developing equipment and the like. |
