Patent US5285074A successfully refreshed from Google Patents.
US5285074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamic compensation of non-linear electron beam landing angle in variable axis lenses
Assignee: International Business Machines Corp
•
Filing: 1992-06-03
•
Granted: 1994-02-08
•
Expires: 2012-06-03
Abstract
Abstract A dynamic correction arrangement for an electron beam projection/deflection system provides high order correction values for deflection in accordance with a correction equation. Particularly as applied to high accuracy telecentric deflection, the coefficients of terms of the correction equation may be determined by calibration for a small number of test points. Correction values may be stored in a look-up table or computed in real time by using a math co-processor in a processing pipeline. The correction provided corrects landing angle errors through the third order in telecentric projection/deflection systems such as systems utilizing variable axis immersion lenses.
Inventors
- 👤 Don F. Haire
- 👤 Cecil T. Ho
- 👤 Guenther O. Langner
- 👤 Werner Stickel
- 👤 Edward V. Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:18
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J2237/00; H01J2237/04; H01J2237/049; H01J2237/0492; H01J2237/04928; H01J2237/15; H01J2237/1506; H01J2237/1507; H01J2237/153; H01J2237/30; H01J2237/304; H01J2237/30455; H01J2237/30461; H01J2237/317; H01J2237/3175
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
157 words
A method for correcting deviations from telecentric deflection in an electron beam projection/deflection system, comprising the steps of applying at least three deflection addresses to said electron beam deflection system, developing deflection currents corresponding to each of said at least three addresses, determining respective locations written corresponding to each of said at least three addresses, computing values of coefficients A, B, and C in the equation: ΔI.sub.x,y =(I.sub.x.sup.2 +I.sub.y.sup.2)[Ax(I.sub.y -I.sub.x)-(I.sub.x.sup.2 +I.sub.y.sup.2)(BI.sub.x,y +CI.sub.y,x)], based on said addresses and currents, wherein ΔI x ,y is a correction current at address x, y and I x and I y , I y , I x ,y and I y ,x are current values corresponding to x and y addresses, determining correction values for deflection currents corresponding to a further address, corresponding to deflection currents at said further address and said values of A, B and C, and correcting said corresponding deflection currents by the amount of said correction current values.
Claim 2
Independent Claim
157 words
A method for correcting deviations from telecentric deflection in an electron beam projection/deflection system, comprising the steps of applying at least three deflection addresses to said electron beam deflection system, developing deflection currents corresponding to each of said at least three addresses, determining respective locations written corresponding to each of said at least three addresses, computing values of coefficients A, B, and C in the equation: ΔI.sub.x,y =(I.sub.x.sup.2 +I.sub.y.sup.2)[Ax(I.sub.y -I.sub.x)-(I.sub.x.sup.2 +I.sub.y.sup.2)(BI.sub.x,y +CI.sub.y,x)], based on said addresses and currents, wherein ΔI x ,y is a correction current at address x, y and I x and I y , I y , I x ,y and I y ,x are current values corresponding to x and y addresses, determining correction values for deflection currents corresponding to a further address, corresponding to deflection currents at said further address and said values of A, B and C, and correcting said corresponding deflection currents by the amount of said correction current values.
Claim 3
Independent Claim
101 words
A method for correcting deviations from telecentric deflection in an electron beam projection/deflection system, comprising the steps of establishing values for coefficients A, B and C in the equation: ΔI.sub.x,y =(I.sub.x.sup.2 +I.sub.y.sup.2)[Ax(I.sub.y -I.sub.x)-(I.sub.x.sup.2 +I.sub.y.sup.2)(BI.sub.x,y +CI.sub.y,x)], wherein ΔI x ,y is a correction current at address x, y and I x , I y , I x ,y and I y ,x are current values corresponding to x and y addresses, determining correction values for deflection currents corresponding to an address and said values of A, B and C, and correcting said deflection currents by the amount of said correction current values.
Claim 4
Independent Claim
101 words
A method for correcting deviations from telecentric deflection in an electron beam projection/deflection system, comprising the steps of establishing values for coefficients A, B and C in the equation: ΔI.sub.x,y =(I.sub.x.sup.2 +I.sub.y.sup.2)[Ax(I.sub.y -I.sub.x)-(I.sub.x.sup.2 +I.sub.y.sup.2)(BI.sub.x,y +CI.sub.y,x)], wherein ΔI x ,y is a correction current at address x, y and I x , I y , I x ,y and I y ,x are current values corresponding to x and y addresses, determining correction values for deflection currents corresponding to an address and said values of A, B and C, and correcting said deflection currents by the amount of said correction current values.
Claim 5
Dependent Claim
136 words
An electron beam projection/deflection system including a deflection means for deflecting said electron beam in response to at least one deflection current applied thereto, a means for developing said at least one deflection current in response to an address, a means for providing correction values in response to said address, said correction values being approximately defined by a solution of the equation: ΔI.sub.x,y =(I.sub.x.sup.2 +I.sub.y.sup.2)[Ax(I.sub.y -I.sub.x)-(I.sub.x.sup.2 +I.sub.y.sup.2)(BI.sub.x,y +CI.sub.y,x)], wherein ΔI x ,y is a correction current at address x, y and I x , I y , I x ,y and I y ,x are current values corresponding to x and y addresses, means for correcting said at least one deflection current in accordance with said correction value to derive a corrected deflection current, and means for applying said corrected deflection current to said deflection means.
Claim 6
Dependent Claim
136 words
An electron beam projection/deflection system including a deflection means for deflecting said electron beam in response to at least one deflection current applied thereto, a means for developing said at least one deflection current in response to an address, a means for providing correction values in response to said address, said correction values being approximately defined by a solution of the equation: ΔI.sub.x,y =(I.sub.x.sup.2 +I.sub.y.sup.2)[Ax(I.sub.y -I.sub.x)-(I.sub.x.sup.2 +I.sub.y.sup.2)(BI.sub.x,y +CI.sub.y,x)], wherein ΔI x ,y is a correction current at address x, y and I x , I y , I x ,y and I y ,x are current values corresponding to x and y addresses, means for correcting said at least one deflection current in accordance with said correction value to derive a corrected deflection current, and means for applying said corrected deflection current to said deflection means.
Claim 7
Dependent Claim
29 words
An electron beam projection/deflection system as recited in claim 3, wherein said means for providing correction values includes a look-up table containing solutions to said equation for selected addresses.
Claim 8
Dependent Claim
38 words
An electron beam projection/deflection system as recited in claim 3, wherein said means for providing correction values includes a multiplier means including means for receiving inputs at least including values of A, B and C and an address.
Claim 9
Dependent Claim
18 words
An electron beam projection/deflection system as recited in claim 5, wherein said multiplier means is a digital multiplier.
Claim 10
Dependent Claim
52 words
An electron beam projection/deflection system as recited in claim 3, wherein said means for providing correction values includes a multiplier means including means for receiving inputs at least including values of solutions to said equations and at least one of an address and a value of said at least one deflection current.
Claim 11
Dependent Claim
18 words
An electron beam projection/deflection system as recited in claim 7, wherein said multiplier means is a digital multiplier.
Claim 12
Dependent Claim
25 words
An electron beam projection/deflection system as recited in claim 3, further including calibration means for determining values of A, B and C in said equation.
Claim 13
Dependent Claim
29 words
An electron beam projection/deflection system as recited in claim 9, wherein said means for providing correction values includes a look-up table containing solutions to said equation for selected addresses.
Claim 14
Dependent Claim
38 words
An electron beam projection/deflection system as recited in claim 9, wherein said means for providing correction values includes a multiplier means including means for receiving inputs at least including values of A, B and C and an address.
Claim 15
Dependent Claim
18 words
An electron beam projection/deflection system as recited in claim 11, wherein said multiplier means is a digital multiplier.
Claim 16
Dependent Claim
52 words
An electron beam projection/deflection system as recited in claim 9, wherein said means for providing correction values includes a multiplier means including means for receiving inputs at least including values of solutions to said equations and at least one of an address and a value of said at least one deflection current.
Claim 17
Dependent Claim
18 words
An electron beam projection/deflection system as recited in claim 13, wherein said multiplier means is a digital multiplier.
Claim 18
Dependent Claim
31 words
An electron beam projection/deflection system as recited in claim 3, wherein said means for providing correction values includes a math coprocessor means for providing solutions to said equation for selected addresses.
Claim 19
Dependent Claim
100 words
An electron beam projection/deflection system including a telecentric deflection means and a dynamic correction means for correcting deviations from telecentricity of greater than first order, said dynamic correction means including means responsive to an address, at least one deflection current corresponding to said address and not more than three coefficients of terms of a correction equation for providing a correction value, means for correcting said at least one deflection current in accordance with said correction value to obtain at least one corrected deflection current and means for applying said at least one corrected deflection current to said telecentric deflection means.
Claim 20
Dependent Claim
100 words
An electron beam projection/deflection system including a telecentric deflection means and a dynamic correction means for correcting deviations from telecentricity of greater than first order, said dynamic correction means including means responsive to an address, at least one deflection current corresponding to said address and not more than three coefficients of terms of a correction equation for providing a correction value, means for correcting said at least one deflection current in accordance with said correction value to obtain at least one corrected deflection current and means for applying said at least one corrected deflection current to said telecentric deflection means.
Claim 21
Dependent Claim
56 words
An electron beam projection/deflection system as recited in claim 16, wherein said correction equation is ΔI.sub.x,y =(I.sub.x.sup.2 +I.sub.y.sup.2)[Ax(I.sub.y -I.sub.x)-(I.sub.x.sup.2 +I.sub.y.sup.2)(BI.sub.x,y +CI.sub.y,x)], wherein ΔI x ,y is a correction current at address x, y and I x , I y , I x ,y and I y ,x are current values corresponding to x and y addresses.
References Cited (Backward Citations)
US4362942A
Cited
US4544846A
Cited
US4789945A
Cited
US4728797A
Cited
US4859856A
Cited
US5047647A
Cited
US5148033A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-07 | 1997-08-09 | 1998-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-07 | 2001-08-09 | 2002-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-07 | 2005-08-09 | 2006-02-08 | $7700.00 | Window Closed / Lapsed |