Abstract: It is an object of the present invention to provide a new method for reducing the diameter of a bubble existing in a glass plate. Specifically, the present invention provides a method for reducing the diameter of a bubble existing in a glass plate, which comprises irradiating the vicinity of the bubble existing in the glass plate with a light beam emitted from a light source, to raise the temperature of the glass in the vicinity of the bubble to at least the melting point of the glass to reduce the maximum diameter of the bubble.

Abstract: The present invention provides a flat glass capable of improving influence on visibility for use in FPD (Flat Panel Display) such as liquid crystal etc. and a process for producing the same. The flat glass has a sheet thickness of from 0.1 to 1.1 mm, especially from 0.3 to 1.1 mm and contains bubbles of 100 to 1,000 ?m in major axis wherein the ratio of minor axis/major axis is 0.85 or greater. This flat glass is produced by forming a molten glass ribbon to a sheet thickness of over 1.0 to 1.5 times a predetermined sheet thickness t of from 0.1 to 1.1 mm under a molten glass ribbon viscosity of log ??5, and thereafter forming the molten glass ribbon to the predetermined sheet thickness t under a molten glass ribbon viscosity of 5<log ??7.65.

Abstract: It is an object of the present invention to provide a method for manufacturing float glass and a device therefor, which are capable of stably holding both edges of a molten glass ribbon. In accordance with gutter-like bodies 12 of a device for manufacturing float glass 10, a portion of molten tin 16 that flows out of outlets 32 of lateral ducts 34 of the gutter-like bodies 12 into vessel edge areas 14A can be directed to a vessel central area 14B through vertical ducts 30 and through holes 36. Since the flow rate q1 of the molten tin 16 that flows from each of the vessel edge areas 14A into each of the inlets 28, and the flow rate q2 of the molten tin 16 that flows from the vessel central area 14B into each of the inlets 28 are substantially equalized along the forward direction of the molten glass ribbon 20.

Abstract: The present invention relates to improvement in a method of supplying a glass ribbon in a molten state to be supplied from a glass melting furnace to a flat glass forming apparatus, which can further improve the smoothness of a flat glass after formed. A glass ribbon 13 supplied from a glass melting furnace 14 to a flat glass forming apparatus 15 is stretched between one pair of tension rollers 24A and 24B in an S-shape and the tension rollers 24A and 24B are rotated while applying a surface pressure to the glass ribbon 13 face via a thin layer of a steam film generated by vaporization of a steam film forming agent. By means of rotation of the tension rollers 24A and 24B, the face of the glass ribbon 13 still in a molten state is polished via the steam film 18.

Abstract: It is an object of the present invention to provide a device for manufacturing float glass, which is capable of not only making the circulation paths for the molten metal compact but also suppressing the occurrence of heat loss.

Abstract: An apparatus 10 for producing a plate glass, comprising a bath 14 for float-forming for reserving a molten metal 16 for forming a band-shaped plate glass having a predetermined thickness by feeding a molten glass ribbon 20 in a predetermined direction on the molten metal 16, and a pair of partition walls 46 provided substantially above left and right edges 22 of the molten glass ribbon 20 and substantially along the edges 22 to partition a space above a bath surface of the molten metal into an upper space A above a region covered with the molten glass ribbon 20 and upper spaces B above regions not covered with the molten glass ribbon 20; wherein the partition walls 46 each has a vertically dividable structure dividable into an upper partition wall 46A and a lower partition wall 46B, and the lower partition wall 46B is constituted by strip-shaped lower strip members 58 provided continuously to each other in a lateral direction, and the strip members 58 are configured to be removable or openable from the upper

Abstract: It is to provide a method for removing a tin defect present on the surface of a glass substrate produced by a float process in a short time without the glass substrate surface being damaged regardless of the glass temperature. A method for removing a tin-containing foreign matter from the surface of glass, which comprises applying to the surface of a glass substrate produced by a float process a pulse laser beam having a transmittance of at least 70% through the glass substrate and having a pulse width, a wavelength and an energy density per unit area on the glass substrate surface which satisfy specific relations, to remove a tin-containing foreign matter present on the rear face opposite to the face irradiated with the pulse laser beam.

Abstract: The present invention relates to production of a flat glass, which can improve the surface smoothness of a flat glass in the moving direction and which prevents formation of stripes on the flat glass. A fixed bed 15 comprising a plurality of supports 12 arranged in such a state that they will not move at least in a direction in parallel with the moving direction of a glass ribbon 13, and having grooves 12B to let loose the steam generated by vaporization of a steam film forming agent formed between the respective supports 12, is used, and the amount of the steam let loose from the grooves is adjusted in accordance with the glass temperature distribution in the moving direction of the glass ribbon 13 which moves on the fixed bed 15.

Abstract: The present invention relates to improvement in a method of supplying a glass ribbon in a molten state to be supplied from a glass melting furnace to a flat glass forming apparatus, which can further improve the smoothness of a flat glass after formed. A glass ribbon 13 supplied from a glass melting furnace 14 to a flat glass forming apparatus 15 is stretched between one pair of tension rollers 24A and 24B in an S-shape and the tension rollers 24A and 24B are rotated while applying a surface pressure to the glass ribbon 13 face via a thin layer of a steam film generated by vaporization of a steam film forming agent. By means of rotation of the tension rollers 24A and 24B, the face of the glass ribbon 13 still in a molten state is polished via the steam film 18.

Abstract: A process for producing float glass for a glass substrate particularly for LCD or PDP, the process comprising continuously supplying molten glass on molten tin, stretching the molten glass to form a glass ribbon, and cutting the glass ribbon after it is separated from the molten tin, characterized in that the temperature T0 of the glass ribbon when it is separated from the molten tin is from (TG?50° C.) to (TG+30° C.), where TG is the glass transition point of the float glass.

Abstract: A method and apparatus for producing a sheet glass includes pouring a molten glass into a bathtub containing a molten metal so that it will form a molten glass stream having a constant width in a high temperature zone on the molten metal bath. The molten glass stream in the form of a ribbon having a desired thickness is led into a subsequent shaping zone, wherein, in the high temperature zone, the molten metal level in the vicinity of the edge of the molten glass stream is differentiated from the molten metal level at the center of the glass stream to complement a force of the molten glass stream for expanding or contracting in the width direction and thereby to maintain the edge at a predetermined position.

Abstract: A method for holding an edge of a molten glass flow, comprising forming a molten glass flow by continuously feeding molten glass on a bath surface of molten metal contained in a vessel, holding an edge of the molten glass flow in a width direction thereof when advancing the molten glass flow to draw the molten glass flow in a glass ribbon having a target thickness, and controlling a flow of the molten metal so that a bath surface level in height of the molten metal in the vicinity of the edge of the molten glass flow is different from that of the molten metal in the vicinity of a central portion of the molten glass flow in the width direction thereof, whereby a force to spread or narrow the molten glass flow in the width direction is compensated so as to hold the edge of the molten glass flow at a predetermined position.

Abstract: A process for producing a flat glass, which comprises withdrawing a glass ribbon substantially horizontally from the surface of a molten metal bath while maintaining the level of the surface of the molten metal at a level higher than an end wall at the outlet of the bath from which the glass ribbon is withdrawn and preventing the overflow of the molten metal from the end wall by means of a force induced by a linear induction motor, wherein side walls at the outlet of the bath are made of an electroconductive material thereby to prevent a drop of the induced force in the vicinity of the side walls.