Laser processing head and method for compensating for the change in focus position in a laser processing head
First Claim
1. A laser processing head for processing a workpiece by means of a working laser beam, comprisinga camera with an imaging optical unit arranged upstream thereof in a beam path and serving for observing a processing region of the workpiece which is processed by means of the working laser beam,a focusing optical unit for focusing the working laser beam with a processing laser light wavelength (λ
-
L) onto the workpiece surface or onto a position defined relative to the workpiece surface,an illumination device to illuminate the processing region of the workpiece with light having a wavelength (λ
K) of an observation system,an evaluation unit, which is designed to calculate a correction adjustment travel (Δ
zOS, Δ
zB) which compensates for a focal point displacement of the focusing optical unit relative to the workpiece surface or to a position defined relative to the workpiece surface by means of an adjustment travel (Δ
dKL) of the imaging optical unit in the direction of the optical axis, which is necessary for focusing the camera image again in the event of a displacement of the focal point of the focusing lens,wherein the evaluation unit is designed, in the calculation of the correction adjustment travel (Δ
zOS, Δ
zB) of the focusing optical unit from the adjustment (Δ
dKL) of the imaging optical unit, to include in the calculation focusing differences of the imaging optical unit and of the focusing optical unit on account of the different wavelengths of the observation system (λ
K) and the working laser light wavelength (λ
L).
1 Assignment
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Accused Products
Abstract
The invention relates to a laser machining head (100) for machining a workpiece by means of a working laser beam (108), with a camera (102) with an imaging lens system (116) arranged in front of said camera in the beam path for observing a machining region of the workpiece that is being machined by means of the working laser beam (108), with a focusing lens system (114) for focusing the working laser beam (108) on the workpiece surface (104) or on a position defined in relation to the workpiece surface (104), and with an evaluation unit (122) which is designed to calculate a corrective adjusting displacement (ΔZos, ΔZB) by means of an adjusting displacement (ΔdKL) of the imaging lens system (116) in the direction of the optical axis in order to refocus the camera image when there is a shift in the focal point of the focusing lens system (114), which corrective adjustment displacement compensates a shift in the focal point of the focusing lens system (114) in relation to the workpiece surface (104) or with respect to a position defined in relation to the workpiece surface (104).
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Citations
15 Claims
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1. A laser processing head for processing a workpiece by means of a working laser beam, comprising
a camera with an imaging optical unit arranged upstream thereof in a beam path and serving for observing a processing region of the workpiece which is processed by means of the working laser beam, a focusing optical unit for focusing the working laser beam with a processing laser light wavelength (λ -
L) onto the workpiece surface or onto a position defined relative to the workpiece surface,
an illumination device to illuminate the processing region of the workpiece with light having a wavelength (λ
K) of an observation system,an evaluation unit, which is designed to calculate a correction adjustment travel (Δ
zOS, Δ
zB) which compensates for a focal point displacement of the focusing optical unit relative to the workpiece surface or to a position defined relative to the workpiece surface by means of an adjustment travel (Δ
dKL) of the imaging optical unit in the direction of the optical axis, which is necessary for focusing the camera image again in the event of a displacement of the focal point of the focusing lens,wherein the evaluation unit is designed, in the calculation of the correction adjustment travel (Δ
zOS, Δ
zB) of the focusing optical unit from the adjustment (Δ
dKL) of the imaging optical unit, to include in the calculation focusing differences of the imaging optical unit and of the focusing optical unit on account of the different wavelengths of the observation system (λ
K) and the working laser light wavelength (λ
L). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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L) onto the workpiece surface or onto a position defined relative to the workpiece surface,
Specification