Abstract: To provide a fabricating method and a fabricating apparatus of a planar glass molded article and a glass substrate capable of fabricating a thinner planer glass molded article in a state having small warp without extending cycle time and an information recording medium, a method of providing a planar glass molded article by pressing a glass material to be molded by using molds at least including an upper mold and a lower mold, includes a step of supplying the glass material to be molded having temperature higher than a glass transition point to a molding surface of the lower mold, a step of molding planar glass by press-molding the supplied glass material to be molded by the lower mold and the upper mold, a step of removing the upper mold from the planar glass and taking out the planar glass on the molding surface of the lower mold from the molding surface of the lower mold, a step of cooling the planar glass to temperature lower than a strain point of the glass, and a step of annealing the provided planar gl

Abstract: A glass substrate contains at least ZrO2 and Li2O. In this event, ZrO2 has a content which falls within the range between 0.6 and 1.9 mol % while Li2O has a content which falls within the range between 6 and 14 mol %. Thus, the contents of ZrO2 and Li2O are restricted to a predetermined range. Consequently, the projections of the undissolved substance of ZrO2 are not formed on the surface of the glass substrate. As a result, the glass substrate having the flat surface can be obtained.

Abstract: A glass substrate manufacturing method advantageously applicable to magnetic recording disk glass substrates, LCD glass substrates, photomasks glass substrates, or optical memory glass substrates. The method includes the steps of forming a film of a solution on at least a principal surface of a sheet glass formed using a down-drawing method, the solution containing a water soluble inorganic material and a surface-active agent; sandwiching both sides of a single sheet glass on which the film is formed or of a laminated structure of two or more sheet glasses with a densified sheet with a high flatness to pressure the single glass or laminated structure; and heating and annealing the single sheet glass or laminated structure to flatten the same. The end side of the flatten glass substrate is treated with a treating solution containing a hydrofluosilicic acid.

Abstract: A glass substrate manufacturing method advantageously applicable to magnetic recording disk glass substrates, LCD glass substrates, photomask glass substrates, or optical memory glass substrates. The glass substrate is formed by chemically strengthening a glass substrate by immersing the glass substrate in a chemical reinforcement solution heated and then ion exchanging ions on the surface layer of the glass substrate with ions in the chemical reinforcement solution; removing the substrate from the chemical reinforcement solution and then annealing it to a temperature higher than the crystallization temperature of a molten salt; rapidly cooling the glass substrate at a rate at which the crystallization of the molten salt deposited on the surface of the glass substrate is prevented; and then cleaning the surface of the glass substrate.

Abstract: A method for manufacturing a magnetic recording disk including the steps of forming a film of solution on at least a principal surface of a sheet glass; the solution contains a water soluble inorganic material and a surface active agent; sandwiching both sides of a single sheet glass on which the film is formed or on a laminated structure of plural sheet glasses with a densified sheet with a high flatness to pressure the single glass or laminated structure; and heating and annealing the single sheet glass or laminated structure to flatten it. The end side of the flattened glass substrate is treated with a treating solution containing hydrofluosilicic acid.

Abstract: A glass substrate manufacturing method advantageously applicable to magnetic recording disk glass substrates, LCD glass substrates, photomask glass substrates, or optical memory glass substrates. This method includes the steps of forming a film of a solution on at least a principal surface of a sheet glass formed using a down-drawing method, the solution containing a water soluble inorganic material and a surface-active agent; sandwiching both sides of a single sheet glass on which the film is formed or of a laminated structure of plural sheet glasses with a densified sheet with a high flatness to pressure the single glass or laminated structure; and heating and annealing the single sheet glass or laminated structure to flatten the same. The end side of the flatten glass substrate is treated with a treating solution containing a hydrofluosilicic acid.