Patent ID: 6459951
Filing Date: 2002-10-01
Classification: B23K,G05B

Abstract:
A feedback controlled direct laser fabrication system, comprising:a) a direct laser fabrication apparatus, said apparatus comprising: i) a laser whose output is directed onto a locus on a growth surface; ii) a growth material feeder which delivers growth material to the region immediately surrounding said locus; iii) a traverse mechanism moving the locus in three dimensions about the growth surface; and, iv) a regulator which adjusts a set of controllable parameters of said apparatus to match control values generated by a scheduler; b) a two-color imaging pyrometer comprising imaging optics which form an image of the region immediately surrounding the locus, a dichroic beamsplitter to split said image into a first image at a first optical passband and a second image at a second optical passband, a first imaging camera directed at said first image, and a second imaging camera directed at said second image, where the first imaging camera delivers said first image in the form of a first set of imaging data, where said first set of imaging data comprises the distribution of optical intensity within said first image, and the second imaging camera delivers said second image in the form of a second set of imaging data, where said second set of imaging data comprises the distribution of optical intensity within said second image; and, c) a feedback system, comprising: i) an image analyzer, which accepts said first set of imaging data and said second set of imaging data and extracts therefrom a set of current intrinsic parameters; ii) a database comprising a predetermined operating schedule for fabricating a given component, and a set of target intrinsic parameters; iii) a corrector, which accepts as input the set of current intrinsic parameters, the set of target intrinsic parameters, and the predetermined operating schedule, and generates feedback-driven adjustments to said predetermined operating schedule therefrom; and, iv) said scheduler which accepts as input the feedback-driven adjustments, and the predetermined operating schedule for fabricating a given component, generates therefrom control values for the controllable parameters, and transfers said control values to the regulator.