Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
164 words
An optical lithographic device with a lens system which has a vertical optical main axis directed parallel to a z-direction and which is fastened to a machine frame of the device, as well as a positioning device which is situated below the lens system and by means of which an object table is displaceable relative to the lens system over a guide surface of a support member coupled to the positioning device, which guide surface extends perpendicular to the z-direction, characterized in that the device is provided with a force actuator system which is fastened to a reference frame of the device and is controlled by a feedforward control system, whereby the force actuator system during operation exerts a compensatory force on the machine frame with a direction which is opposed to a direction of a reaction force exerted simultaneously on the support member by the positioning device, and with a value which is substantially equal to a value of the said reaction force.
Claim 2
Dependent Claim
36 words
An optical lithographic device as claimed in Claim 1, in which the support member forms a base of the machine frame, characterized in that the force actuator system exerts the compensatory force on the support member.
Claim 3
Dependent Claim
64 words
An optical lithographic device as claimed in Claim 1, in which the lens system is fastened near a lower side to a mounting member belonging to the machine frame, characterized in that the force actuator system exerts the compensatory force on a carrier suspended from the mounting member, on which carrier the positioning device and the support member have been provided as a unit.
Claim 4
Dependent Claim
38 words
An optical lithographic device as claimed in Claim 3, characterized in that the reference frame is formed by a base of the optical lithographic device on which the mounting member is fastened by means of lower frame supports.
Claim 5
Dependent Claim
61 words
An optical lithographic device as claimed in any one of the preceding Claims, characterized in that the control system comprises a negative acceleration feedback, whereby the force actuator system exerts a control force on the machine frame which has a value and a direction which are determined by an acceleration of the machine frame measured by means of an acceleration transducer.
Claim 6
Dependent Claim
77 words
An optical lithographic device as claimed in any one of the preceding Claims, characterized in that the force actuator system comprises a first and a second force actuator which each act parallel to a first displacement direction of the positioning device perpendicular to the optical main axis, and a third force actuator which acts parallel to a second displacement direction of the positioning device perpendicular to the optical main axis and perpendicular to the first displacement direction.
Claim 7
Dependent Claim
66 words
An optical lithographic device as claimed in Claim 6, characterized in that each of the force actuators is provided with an electric motor fastened to the reference frame and with a connecting rod extending parallel to the relevant displacement direction, a first rod end being eccentrically pivoted to an output shaft of the electric motor and a second rod end being pivoted to the machine frame.
Claim 8
Dependent Claim
62 words
An optical lithographic device as claimed in Claim 1, 2, 3, 4 or 5, characterized in that the force actuator system comprises at least one electromagnet with a magnetic flux density transducer, an electrical output of the magnetic flux density transducer being connected to an electrical input of an electronic control circuit with which a force exerted by the electromagnet is controllable.
Claim 9
Dependent Claim
53 words
An optical lithographic device as claimed in Claim 8, characterized in that the control circuit is provided with an electronic root extractor whose input signal is formed by an input signal of the control circuit and has a value which is determined by a desired electromagnetic force to be exerted by the electromagnet.
Claim 10
Dependent Claim
74 words
An optical lithographic device as claimed in Claim 8 or 9, characterized in that the force actuator system comprises three electromagnets which are fastened to the reference frame of the device in a triangular arrangement in a plane perpendicular to the optical main axis, each of the electromagnets being active in a direction which is 120° rotated relative to the directions in which the other two electromagnets of the force actuator system are active.