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US 7,154,242 B2Granted
Moving member mechanism and control method therefor
AssigneeCanon Kabushiki Kaisha
InventorTosiya Asano
Life of this patent
Estimating the term…
Abstract
A moving member mechanism includes an electromagnet having a coil for driving a moving member, a first control mechanism which has an input portion which receives command information and an amplifier which supplies a current to the coil, and an offset compensation mechanism which includes a first integrator which time-integrates a signal at an input portion of the amplifier. The offset compensation mechanism is configured to negatively feed back an output from the first integrator to the input portion of the first control mechanism.
Claims14
An exposure apparatus comprising:
- an optical system which projects exposure light incident on a mask bearing a pattern onto a substrate;
- and
- a stage apparatus which holds and aligns the substrate or the mask,
- the stage apparatus including:
- (i) an electromagnet having a coil for driving the substrate or the mask;
- (ii) a first control system which has an input portion which receives command information and an amplifier which supplies a current to the coil;
- and
- (iii) an offset compensation system comprising a first integrator which time-integrates a signal at an input portion of the amplifier,
- wherein the offset compensation system is configured to negatively feed back an output from the first integrator to the input portion of the first control system.
6 more elements
A moving member mechanism comprising:
- an electromagnet having a coil for driving a moving member;
- a first control system which has an input portion which receives command information and an amplifier which supplies a current to the coil;
- and
- an offset compensation system which comprises a first integrator which time integrates a signal at an input portion of the amplifier,
- wherein the offset compensation system is configured to negatively feed back an output from the first integrator to the input portion of the first control system, and
- wherein the offset compensation system is controlled such that the current supplied from the amplifier to the coil is set to zero when the command information represents zero.
3 more elements
A moving member mechanism comprising:
- an electromagnet having a coil for driving a moving member;
- a first control system which has an input portion which recieves command information and an amplifier which supplies a current to the coil;
- and
- an offset compensation system which comprises a first integrator which time integrates a signal at an input portion of the amplifier,
- wherein the offset compensation system is configured to negatively feed back an output from the first integrator to the input portion of the first control system, and
- wherein the offset compensation system comprises a first hold switch which performs the negative feed back when the command information represents zero, and sends a preceding value to the input portion when the command information does not represents zero.
3 more elements
A moving member mechanism comprising:
- an electromagnet having a coil for driving a moving member;
- a first control system which has an input portion which recieves command information and an amplifier which supplies a current to the coil;
- an offset compensation system which comprises a first integrator which time integrates a signal at an input portion of the amplifier;
- a gap sensor which measures a gap between the electromagnet and the moving member;
- a gap correction unit which calculates a predetermined correction coefficient on the basis of the gap measured by the gap sensor;
- a current calculation unit which calculates a current supplied to the electromagnet on the basis of the command information;
- and
- a multiplier which multiplies by the correction coefficient the current calculated by the current calculation unit,
- wherein the offset compensation system is configured to negativeley feed back an output from the first integrator to the input portion of the first control system.
6 more elements
A moving member mechanism comprising:
- an electromagnet having a coil for driving a moving member;
- a first control system which has an input portion which recieves command information and an amplifier which supplies a current to the coil;
- an offset compensation system which comprises a first integrator which time integrates a signal at an input portion of the amplifier;
- a search coil which measures an induced voltage generated in the electromagnet;
- a second integrator which time integrates the induced voltage measured by the search coil;
- and
- a second control system which feedback controls the electromagnet on the basis of a difference value between the command information and the induced voltage time integrated by the second integrator,
- wherein the offset compensation system is configured to negatively feed back an output from the first integrator to the input portion of the first control system.
5 more elements
A method of controlling a moving member mechanism including an electromagnet having a coil for driving a moving member and an amplifier which supplies a current to the coil, said method comprising:
- a control step of controlling the electromagnet on the basis of input command information;
- and
- an offset compensation step of time integrating a signal at the input portion of the amplifier, and negatively feeding back a time integrated value to the command information input in the control step,
- wherein the offset compensation step includes a step of setting the current supplied from the amplifier to the coil zero when the command information represents zero.
1 more element
A method of controlling a moving member mechanism including an electromagnet having coil for driving a moving member and an amplifier which supplies a current to the coil, said methog comprising:
- a control step of controlling the electromagnet on the basis of input command information;
- and
- an offset compensation step of time integrating a signal at the input portion of the amplifier, negatively feding back a time integrated value to the command information input in the control step,
- wherein the offset compensation step further includes a step of performing the negative feed back when the command information represents zero, and sending a preceding value to the command information input in the control step when the command information does not represent zero.
1 more element
Dependencies are inferred from the claim text.