Motion damper with electrical amplifier, and lithographic device with such a motion damper
US6008881A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1997 |
| Grant date | Dec 28, 1999 |
| Priority date | — |
| Expiry date | Nov 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70833
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A motion damper (1) with a first part (3) and a second part (5) which are mutually displaceable parallel to a damping direction (X). The first part (3) including a permanent magnet system (35), and the second part (5) including an electric actuator coil (25) which is positioned in the magnetic field of the magnet system (35). According to the invention, the motion damper (1) including an electrical amplifier (53) for amplifying an electric current generated in the actuator coil (25) under the influence of a movement of the actuator coil (25) in the magnetic field of the magnet system (35). Since the electric current is amplified, the interaction between the electric current and the magnetic field of the magnet system (35) provides a sufficient electromagnetic damping force with a substantially ideal linear damping characteristic. In a special embodiment, the motion damper including two substantially identical measuring coils (27, 29) which are arranged on either side of the actuator coil (25), and two mutually oppositely magnetized magnet systems (37, 39) for cooperating with the measuring coils (27, 29), while the amplifier (53) supplies the actuator coil (25) with a current which…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.