Lithographic printing system with placement corrections
View Patent ↗The technology disclosed relates to methods and devices that compensate for displacements in a pattern or deformations of a workpiece. In particular, this relates to using timing to compensate for displacements along a first axis along the scanning direction while using resampling, interpolation or a similar method to compensate for displacements along a second axis that is substantially orthogonal to the first axis. The scanning direction may be an actual direction of movement of the scanning head or it may be a direction perpendicular to an orientation of an image projected onto a workpiece.
1. A method of correcting for deformations from an ideal rasterized pattern when projecting an image onto a deformed workpiece, the method including:
rasterizing pattern data to an ideal grid;
representing displacements across an area of the workpiece that correct deformations from the ideal grid as displacement vectors; and
delivering data to a modulator having numerous pixels oriented along at least a transverse direction, using timing of the data delivery to compensate for the displacements in a scan direction and calculating pixel data values that compensate for the displacements in the transverse direction.
2. The method of claim 1 , wherein the modulator projects an image onto a workpiece, the modulator relaying the image along a rotating arm through optics that maintain a substantially constant orientation of the projected image on the workpiece relative to a first axis, further including using the timing of the data delivery to compensate for the displacements in the scan direction, defined as perpendicular to a major axis of the projected image.
3. The method of claim 1 , further including retrieving the rasterized pattern data from one or more columns of a Cartesian data grid and combining data values in the columns of data to calculate pixel data values that compensate for the displacements in the transverse direction by resampling from the rasterized pattern data to lower resolution modulator pattern data.
4. The method of claim 1 , further including retrieving the rasterized pattern data from at least one column of a Cartesian data grid and interpolating between data values in the column to produce pixel data values that compensate for the displacements in the transverse direction.
5. The method of claim 1 , further including updating some of the displacement vectors that correct the deformations while delivering the data to the modulator that compensates for the deformations using others of the displacement vectors.
6. A method of compensating for distortion of a workpiece while printing rasterized pattern data using a modulator having numerous pixels along at least a length of the modulator, the method including:
accessing local displacement vectors stored in memory that map compensation for distortion of the workpiece;
calculating data values along the length of a modulator to compensate for the distortion in a first direction; and
adjusting timing of data feed to the modulator to compensate for the distortion in a second direction, substantially orthogonal to the first direction.
7. The method of claim 6 , wherein the modulator projects an image onto a workpiece, the modulator relaying the image along a rotating arm through optics that maintain a substantially constant orientation of the projected image on the workpiece relative to a first axis, further including using the timing of the data feed to compensate for the displacements in the second direction, defined as perpendicular to a major axis of the projected image.
8. The method of claim 6 , further including retrieving rasterized pattern data from one or more columns of a Cartesian data grid and combining data values in the columns of data to calculate pixel data values that compensate for the displacements in the first direction by resampling from the rasterized pattern data to lower resolution modulator pattern data.
9. The method of claim 6 , further including retrieving the rasterized pattern data from at least one column of a Cartesian data grid and interpolating between data values in the column to produce pixel data values that compensate for the displacements in the first direction.
10. The method of claim 6 , further including updating some of the displacement vectors that correct for the distortion of the workpiece while feeding the data to the modulator.
11. A deformation correction device that corrects for deformations from an ideal rasterized pattern when projecting an image onto a deformed workpiece, the device including:
a memory;
at least one processor coupled to the memory;
a first module running on the processor that rasterizes pattern data to an ideal grid;
an alignment displacement map stored in the memory that represents deformations across a workpiece from the ideal grid in a scan direction and a transverse direction as displacement vectors;
a modulator having numerous pixels oriented along the least the transverse direction, the modulator coupled to the processor; and
a second module running on the processor that delivers data to the modulator using timing of the data delivery to compensate for the displacements in the scan direction and calculating pixel data values that compensate for the displacements in the transverse direction.
12. The device of claim 11 , further including an optical path along a rotating arm from the modulator that projects an image onto a workpiece, wherein the modulator and optical path relays an image to the workpiece that maintains a substantially constant orientation of the projected image on the workpiece relative to a first axis, wherein using the timing of the data delivery to compensate for the displacements in the scan direction defines the scan direction as perpendicular to the first axis.
13. The device of claim 11 , further wherein the second module retrieves the rasterized pattern data from one or more columns of a Cartesian data grid and resamples the columns of data from the ideal grid to a lower resolution for the delivery to the modulator.
14. The device of claim 11 , further wherein the second module retrieves the rasterized pattern data from at least one column of a Cartesian data grid and interpolates between data values in the column to produce pixel data values that compensate for the displacements in the transverse direction.
15. The device of claim 11 , further including a third module running on the processor that updates some of the displacement vectors that correct the deformations while the second module delivers the data to the modulator that compensates for the deformations using others of the displacement vectors.
16. A device that compensates for distortion of a workpiece in rasterized pattern data adapted for use by a modulator having numerous pixels along at least a length of the modulator, the device including:
a memory;
at least one processor coupled to the memory;
displacement vectors stored in the memory that map compensation for distortion in a first direction and in a second direction, substantially orthogonal to the first direction;
a first module running on the processor, accessing the displacement vectors and calculating data values of pixels along the length of a modulator to compensate in data for the distortion in the first direction; and
a second module running on the processor, that adjusts timing of data feed to the modulator to compensate for the distortion in the second direction.
17. The device of claim 16 , further including optics coupled to the modulator that project an image along a rotating arm onto a workpiece while maintaining a substantially constant orientation of the projected image on the workpiece relative to a first axis, further including using the timing of the data feed to compensate for the displacements in the second direction, defined as perpendicular to the first axis.
18. The device of claim 16 , wherein the second module retrieves rasterized pattern data from one or more columns of a Cartesian data grid and combines the data values in the columns by resampling rasterized pattern data to lower resolution to be fed to the modulator.
19. The device of claim 16 , wherein the second module retrieves rasterized pattern data from one or more columns of a Cartesian data grid and interpolates between data values in the columns to produce pixel data values that compensate for the displacements in the first direction.
20. The device of claim 16 , further including a third module running on the processor that updates some of the displacement vectors that correct the distortions while the second module delivers the data to the modulator that compensates for the distortions using others of the displacement vectors.