Device and a process for monitoring a melt for the production of crystals
AssigneeLeybold Systems GmbH
InventorsBurkhard Altekrüger, Joachim Aufreiter, Dieter Brüss, Klaus Kalkowski
Life of this patent
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Abstract
A device for monitoring a melt for the production of crystals. A camera is provided which images at least portions of the surface of the contents of a crucible. An evaluating device is used to evaluate the camera's images with respect to solid and liquid portions of the surface of the crucible contents.
Claims19
A device for monitoring the surface of the contents of a crucible, comprising a camera which images at least portions of said surface wherein said surface comprises solid and liquid portions having different optical properties and an evaluation device which evaluates the camera's image with respect to solid and liquid portions of the surface of the crucible contents.
A method for monitoring the melting process in a crucible by observing the surface of the contents of the crucible by means of a video camera, said method comprising the following steps:
- a) imaging at least portions of the surface of the contents of said crucible by said camera;
- b) scanning points of the imaged portion line by line and/or column by column and recording the brightness of scanned points;
- c) comparing the brightness of adjacent points on a line and/or a column;
- d) storing coordinates of brightness transitions when a predetermine difference in brightness between two adjacent points is identified;
- e) determining liquid and solid areas in the surface of the contents of the crucible by coating the numbers of adjacent points with predetermined difference in brightness;
- and
- f) initiating a process step when a predetermined relationship between solid and liquid portions has been recognized.
A method for monitoring the melting process in a crucible by observing the surface of the contents of the crucible by means of a video camera, said method comprising the following steps:
- a) imaging at least portions of the surface of the contents of said crucible by said camera;
- b) scanning points of the imaged portion line by line and/or column by column and recording the chrominance of scanned points;
- c) comparing the chrominance of adjacent points on a line and/or a column;
- d) storing coordinates of brightness transitions when a predetermine difference in chrominance between two adjacent points is identified;
- e) determining liquid and solid areas on the surface of the contents of the crucible by counting the number of adjacent points with predetermined difference in chrominance;
- and
- f) initiating a process step when a predetermined relationship between solid and liquid portions has been recognized.
Dependencies are inferred from the claim text.