| 摘要 |
PURPOSE:To expand an area where a uniform bias magnetic field is obtained and to increase the capacity of a magnetic bubble memory, by superposing and sticking adhesively magnetic adjusting plates which have longer sides than one side of a permanent magnet for applying a bias magnetic field on permanent magnet surfaces. CONSTITUTION:Coils 2a and 2b for applying a revolving magnetic field to a memory chip 1, permanent magnets 3a and 3b for applying a bias magnetic field to the memory chip 1, and a magnetic shield case 5 are provided, and magnetic adjusting plates 4a and 4b have longer sides than magnetic poles of the permanent magnets 3a and 3b have. Namely, outer circumference of the magnetic adjusting plates 4a and 4b project from the permanent magnets 3a and 3b. Then when the sides of the permanent magnets 3a and 3b are l0, the sides of the magnetic adjusting plates 4a and 4b are 1.1l0. |
