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EP0339402A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Light beam positioning system

Assignee: Electro Scientific Industries Inc
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Filing: 1989-04-14
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Granted: —
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Expires: 2009-04-14
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Abstract

Abstract A light beam positioning system (10) has the capability of generating accurately positioned beam paths at programmed velocities between any two positions on a target surface (18). The beam positions correspond to beam position and velocity command data processed by a system control computer (22). The invention employs an error correction processor (52) that receives X and Y position coordinate signals (X and Y signals) produced by a conventional position data generator and develops compensated X and Y position coordinate signals (X c and Y c signals) for delivery to a light beam positioner (12). The X c and Y c signals are derived from a calibration map of an addressable field representing the positions to which the light beam can be commanded on the target surface. The X c and Y c signals represent polynomial functions of the X and Y signals and offset beam position errors resulting from the light-directing properties of the system optical components (26, 28, 30). The error correction processor allows the use of a single command data file in the system control computer, which is capable of controlling different systems of the same model type. This can be accomplished simply by loading the error correction processor with the pertinent field correction coefficients to the particular light beam positioner in use. Such flexibility is achievable with no changes to software files in the system control computer.

Inventors

  • 👤 Robert M. Pailthorp
  • 👤 Howard V. Goetz
  • 👤 Mark A. Bortnem
  • 👤 Bruce E. Edson

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 07:22
CPC Classifications
G; G02; G02B; G02B27/00; B; B23; B23K; B23K26/00; B23K26/02; B23K26/04; B23K26/042; B23K26/043; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/401; G05B19/4015

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 149 words
A light beam position error correction system employing plural optical components for directing the propagation path of the light beam in response to beam position command data, comprising: light source means to produce a beam of light propagating along a beam path; beam positioning means receiving the beam to direct its path of propagation toward a position on a target surface; position data generating means receiving beam position command data to generate position coordinate signals corresponding to a preselected position on the target surface; and error correction processing means receiving the position coordinate signals to develop compensated position coordinate signals for delivery to the beam positioning means, the compensated position coordinate signals modifying the position coordinate data signals to correct for light beam positioning errors introduced by the system optical components so that the beam positioning means directs the light beam to the preselected position on the target surface.
Claim 2
Dependent Claim 149 words
A light beam position error correction system employing plural optical components for directing the propagation path of the light beam in response to beam position command data, comprising: light source means to produce a beam of light propagating along a beam path; beam positioning means receiving the beam to direct its path of propagation toward a position on a target surface; position data generating means receiving beam position command data to generate position coordinate signals corresponding to a preselected position on the target surface; and error correction processing means receiving the position coordinate signals to develop compensated position coordinate signals for delivery to the beam positioning means, the compensated position coordinate signals modifying the position coordinate data signals to correct for light beam positioning errors introduced by the system optical components so that the beam positioning means directs the light beam to the preselected position on the target surface.
Claim 3
Dependent Claim 86 words
The system of claim 1 in which the compensated position coordinate signals comprise an X c signal and a Y c signal and in which the beam positioning means comprises a pair of first and second independently movable light reflecting surfaces that receive the light beam, the first and second light reflecting surfaces receiving the X c and Y c signals to move the light beam in respective first and second orthogonal directions along the target surface to position the light beam at the preselected position.
Claim 4
Dependent Claim 15 words
The system of claim 2 in which the beam positioning means further comprises a lens.
Claim 5
Dependent Claim 14 words
The system of claim 3 in which the lens is of the F-ϑ type.
Claim 6
Dependent Claim 14 words
The system of claim 1 in which the light source means comprises a laser.
Claim 7
Dependent Claim 104 words
The system of claim 1 in which the position coordinate signals comprise an X signal and a Y signal that indicate the instantaneous commanded position of the light beam, and the compensated position coordinate signals include an X c signal and a Y c signal, the X c signal being a function of the polynomial B₁X+C₁X²+D₁X³+E₁Y+F₁Y²+G₁XY+H₁XY² and the Y c position signal being a function of the polynomial B₂Y+C₂Y²+D₂Y³+E₂X+F₂X²+G₂XY+H₂YX², where B₁, C₁, D₁, E₁, F₁, G₁, H₁, B₂, C₂, D₂, E₂, F₂, G₂, and H₂ represent field correction coefficients of constant values that correspond to the light directing optical properties of the system components.
Claim 8
Dependent Claim 54 words
The system of claim 6 in which the term A₁ is added to the polynomial of which X c is a function and the term A₂ is added to the polynomial of which Y c is a function, the A₁ and A₂ terms representing respective X- and Y-axis offsets in an X-­Y coordinate system.
Claim 9
Dependent Claim 37 words
The system of claim 6 further comprising calibration data file means in data communication with the error correction processing means selectively to store field correction coefficients that characterize the particular light directing properties of a specific system.
Claim 10
Dependent Claim 91 words
The system of claim 1 in which the position coordinate signals comprise an X signal and a Y signal that indicate the instantaneous commanded position of the light beam, and the compensated position coordinate signals include an X c signal and a Y c signal, the X c and Y c signals being proportional to polynomials that include the respective terms G₁XY and G₂YX to correct for position errors resulting from wedge angle distortion and the respective terms H₁XY² and H₂X²Y to correct for position errors resulting from parabolic curvature distortion.

References Cited (Backward Citations)

EP0141724A2 Cited
EP0147525A1 Cited
EP0199650A1 Cited
EP0213104A2 Cited

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