公开(公告)号：EP1808419A4

公开(公告)日：2011-09-07

申请号：EP05795596

申请日：2005-10-20

申请人： SUMITOMO ELECTRIC INDUSTRIES

发明人： NAKANISHI T ,  HIRANO M

IPC分类号： C03B37/018

CPC分类号： C03B37/01823 ,  C03B2207/66 ,  Y02P40/57

摘要： The present invention provides a method for producing an optical fiber preform, in which method it is possible to synthesize and deposit glass at a high rate by the inside CVD method using a plasma burner as a heat source in a manner such that unconsolidated portions or bubbles are little generated in the optical fiber preform. The method includes a step of depositing a glass film on the inner wall surface of a starting pipe, the wall thickness of which is d (mm), by heating from the outer circumferential surface of the pipe while a gas containing a glass raw material is introduced into the pipe, the plasma burner being moved in parallel with the axis of the pipe, wherein in a first embodiment, the temperature is controlled not to exceed (1800 + 100×d)°C, a temperature of (1100 + 100×d)°C or higher being continued for 20 seconds or more at each point of the starting pipe. In a second embodiment of the invention, the plasma burner includes at least two inlets for gases for forming plasma and has an inner diameter of 80 mm or more (sectional area S) in a region where the plasma is formed, and the deposition step is performed in a manner to satisfy the relationship, 150 mm/second

公开(公告)号：EP1496023A4

公开(公告)日：2011-06-22

申请号：EP03723126

申请日：2003-04-16

申请人： SUMITOMO ELECTRIC INDUSTRIES

发明人： HIRANO M ,  YANADA E ,  YOKOKAWA T ,  SASAKI T

IPC分类号： C03B37/012 ,  G02B6/036 ,  G02B6/22

CPC分类号： G02B6/03688 ,  C03B37/01211 ,  C03B37/0124 ,  C03B2203/22 ,  C03B2203/29 ,  C03B2203/36 ,  G02B6/02271 ,  G02B6/03644 ,  G02B6/03666 ,  Y02P40/57

公开(公告)号：EP1471040A4

公开(公告)日：2005-08-17

申请号：EP03703074

申请日：2003-01-29

申请人： SUMITOMO ELECTRIC INDUSTRIES

发明人： MORIYA T ,  ONISHI M ,  SOHMA K ,  HIRANO M ,  YANADA E ,  ENOMOTO T

IPC分类号： C03B19/14 ,  C03B23/045 ,  C03B23/047 ,  C03B23/049 ,  C03B37/012

CPC分类号： C03B37/01254 ,  C03B19/1469 ,  C03B23/045 ,  C03B23/0493 ,  C03B23/0496 ,  Y02P40/57

摘要： A method of manufacturing a glass tube (6), comprising the step of controlling a stress added to the inner peripheral side or outer peripheral side of the glass tube (6) when the glass material (3) is heated by a heating element (41) disposed around the glass material (3) for softening the glass material and the glass material (3) is gradually formed into the glass tube (6) by relatively press-fitting a boring tool (31) in the softened area of the glass material (3), wherein the control of the stress can be performed, for example, by controlling an internal pressure or an external pressure on the glass tube (6), whereby the high quality glass tube (6) can be provided by preventing the glass tube (6) from being deformed immediately after boring, and such a problem with the glass tube (6) that a residual stress after cooling is non-uniformed and cracking tends to occur at the time of re-heating can be solved.