Patent ID: 6531793
Filing Date: 2003-03-11
Classification: G03F,H02K,Y10S

Abstract:
A displacement device comprising a first part (1) and a second part (2) which can be displaced with respect to each other in at least an X-direction and a Y-direction perpendicularly thereto, the first part comprising a carrier (5) which extends substantially parallel to the X-direction and the Y-direction and on which a system (3) of magnets is secured in accordance with a pattern of rows (7) extending parallel to the X-direction, and columns (8) extending parallel to the Y-direction, an equal distance being present between the rows and between the columns, and magnets of a first type (N), having a magnetization direction which extends at right angles to the carrier (5) and towards the second part (2), and magnets of a second type (Z), having a magnetization direction which extends at right angles to the carrier (5) and away from the second part (2), being alternately arranged in each row (7) and in each column (8), and a magnet of a third type (H) being arranged in each column (8) between each pair of juxtaposed magnets of the first (N) and the second type (Z), which magnet of a third type has a magnetization direction which extends parallel to the Y-direction and towards the magnet of the first type (N), while the second part (2) is provided with an electric coil system (4) comprising at least one electric coil of a first type (C1) which has current conductors (9) which are situated in a magnetic field of the system of magnets and which include an angle of substantially 45Â° with the X-direction, and comprising at least one electric coil of a second type (C2), which has current conductors (10) which are also situated in the magnetic field of the system of magnets and which include an angle of substantially 45Â° with the X-direction, and said current conductors extending perpendicularly to the current conductors (9) of the first electric coil (C1), characterized in that in each row (7) of magnets of the first part (1), also a magnet of the third type (H) is arranged between each pair of juxtaposed magnets of the first (N) and the second type (Z), which magnet of the third type has a magnetization direction extending parallel to the X-direction and towards the magnet of the first type (N), and further characterized in that the magnets of the first (N) and the second (Z) type have an identical square shape with side faces (13), in that the magnets of the third type (H) are rectangular in shape with side faces (12, 14), whereby the longest side faces (12) of a magnet of the third type (H) border on the aide faces (13) of a magnet of the first (N) and the second (Z) type and are just as long as the side faces (13) of the magnet of the first and the second type, and the ratio of the dimension of the shortest side face (14) of a magnet of the third type (H) to the dimension of the longest side face (12) ranging between 0.25 and 0.50.