| 摘要 |
PURPOSE:To keep the position of a liquid surface constant and to stably control the diameter of the single crystal by simultaneously measuring both the diameter of the single crystal and the position of the liquid surface with a TV camera for correcting the lowering of the liquid surface and controlling the diameter without being affected by thermal deformation or the like of the crucible. CONSTITUTION:A TV camera 2 for measurement use successively measures both the maximum diameter (d) of single crystal 8 being grown and the position (l) of a sampling line of the maximum diameter (d), and the measured values are inputted to a processing unit 3. This unit 3 calculates the change of the maximum diameter (d) resulting from the pulling-up and sends the data to an interface 4. This interface 4 receives the data and actuates a pulling-up mechanism 6 of single crystal to control the diameter of single crystal 8. On the other hand, the unit 3 compares the position (l) of the sampling line with the previously stored position L of the sampling line at the starting time for controlling the diameter and calculates the displacement amount (l-L), which is sent to the interface 4. This interface 4 is inputted with the displacement amount (l-L) and actuates a pushing-up mechanism 5 of a crucible to control the liquid level 9a.
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