Patent ID: 9726988
Date: 2017-08-08
CPC Classifications: G03F,G05B,Y02P

Claim:
1. A multi-stage system comprising: a carrier extending substantially parallel to a first direction and a second direction, wherein said second direction is perpendicular to the first direction; a first stage that is moveable relative to the carrier in the first and second directions; a second stage that is moveable relative to the carrier in the first and second directions; wherein the first and second stages are each provided with a system of magnets to generate a magnetic field, wherein the carrier is provided with an array of electric coils, said electric coils being configured to interact with the magnetic fields generated by the system of magnets of the first and second stages to generate forces on the first and second stages to position the first and second stages relative to the carrier, and wherein each system of magnets includes first magnets having a magnetization direction along a third direction substantially perpendicular to the first and second directions and directed towards the carrier and second magnets having a magnetization direction along the third direction and directed away from the carrier, the first and second magnets being arranged in accordance with a pattern of odd number of rows and odd number of columns substantially perpendicular thereto, such that the first and second magnets are arranged in each row and in each column alternately, and wherein the system of magnets of the first stage has the first magnets arranged on diagonals of the pattern and the system of magnets of the second stage has the second magnets arranged on the diagonals of the pattern.