公开(公告)号：JPS55130835A

公开(公告)日：1980-10-11

申请号：JP3762079

申请日：1979-03-28

Applicant: FUJITSU LTD

Inventor： GOTOU JIYUNJIROU ,  TATSUTA TAKASHI ,  KAWABATA YOSHIO

IPC: C03B37/023 ,  G02B6/00

Abstract: PURPOSE:To prepare an optical fiber with good shape and optical property by a method wherein a crusible having a U-shaped tube portion is used between a glass melting portion and a spinning nozzle portion and a predetermined pressure applied from a nozzle leading end portion is removed during spinning. CONSTITUTION:A stock glass material 11 for a core and a stock glass material 12 for a clad are respectively inserted into a melting portion 2, 3, and temp. of a heating furnace 1 is adjusted in a condition applying pressure P from an air sending pipe 7 to melt respective glass material 11, 12. The pressure P is adjusted to a pressure such that molten glass is not flowed out from a U-shaped pipe 4, 5. Thereby, when stock glass materials 11, 12 are molten, a temp. of a furnace 1 is lowered to a spinning temp. as well as a portion of a nozzle 6 is heated to a spinning temp. by a heating furnace 8 and, at the same time, a condition removing an air sending pipe 7 as a pressurizing means is made and an optical fiber is spun.

公开(公告)号：JPS54120738A

公开(公告)日：1979-09-19

申请号：JP2915678

申请日：1978-03-13

Applicant: FUJITSU LTD

Inventor： GOTOU JIYUNJIROU ,  KAWABATA YOSHIO ,  TATSUTA TAKASHI

IPC: C03B37/023 ,  G02B6/00

Abstract: PURPOSE:The title device designed to manufacture optical fibers with little loss in light transmission without forming air bubbles in spinning, wherein partition plates having through-holes are attached inside the crucible for preparing glass material so as to be immersed in the molten glass. CONSTITUTION:Molten glass above the partition plates 2 and 5 at about 1400 deg.C is agitated by blowing a dry, oxidizing, or reducing gas from the nozzles 8, and the small holes 3 and 6 are not provided immediately under the nozzles 8. Air bubbles formed by the nozzles 8 are prevented from going under the plate 2. The molten glass flows through the holes 3 and 6 downward, and the remaining fine air bubbles are made to escape upward through the holes 3 and 6 while clarifying the glass. The temperature of the furnace 7 is set so that the suitable low viscosity of the glass in the clarifying layer may facilitate the bubble escaping.

公开(公告)号：JPS54116430A

公开(公告)日：1979-09-10

申请号：JP2381378

申请日：1978-03-01

Applicant: FUJITSU LTD

Inventor： GOTOU JIYUNJIROU ,  KAWABATA YOSHIO ,  TATSUTA TAKASHI

IPC: C03B37/023 ,  C03B37/012 ,  G02B6/00

Abstract: PURPOSE:Flat quartz plates or the likes are made to float on the liquid surface of a molten composition for making glass in a quartz crucible, thereby preventing the contamination of glass rods by foreign substance that are caused by flowing down from th bottom of the crucible. CONSTITUTION:After a disc 11 is made to float on the surface of molten glass that is formed by heating a compound for glass making in a crucible 2 with an electric furnace 3, the molten glass 9 is made to flow down from nozzles 4 and solidified by cooling to form a glass rod or optical fiber 6. The surface of the molten glass goes down horizontally without being engulfed into the center of the crucble and foreign materials 10 also goes down keeping close contact with the disc 11 and are not included into the molten glass.