| 摘要 |
PURPOSE:To obtain a linear driving magnetic field and drive a body to be driven linearly and efficiently, and produce a driving device of a small size and a low cost by arranging a couple of cylindrical or columnar magnets adequately in pertinent polarization directions, and providing a coil for linear driving. CONSTITUTION:A couple of columnar magnets 20A and 20B are disposed together as connected vertically on the same axial line A, and their same poles, i.e. N poles are put close as opposed to each other. Consequently, magnetic flux from each entire N-pole area converges from the boundary position where the N poles are opposed and the diverges. The magnetic flux diverges toward an axial line A at the hollow part 21 of the magnet to form a space with high magnetic flux density at the side of the axial line A near said boundary position. Further, four orthogonal projection parts 22a-22d of an objective lens holder 22 made of soft magnetic material are wound with coils 28A and 28B, and 29A and 29B for x-axis and y-axis linear driving. Then, the projection parts are magnetized by the driving currents of said driving coils to drive an objective lens 26 efficiently and linearly by the attraction and repulsion between the N poles of the magnets 20A and 20B. Further, the number of turns of each coil may by small and the size and weight of the driving part are reduced. |
