Abstract: An object of the present invention is to provide a glass plate capable of suppressing deformation of a glass product that is subject to load in a heat treatment process at a temperature not more than the glass strain point, such as chemical strengthening and coating. The present invention relates to a glass plate for heat treatment, in which the dimensionless index determined by the following formula is 1.6×10?4 or less, the average viscosity ? is log ??15.1 log Pa·s or less, the relationship between the fictive temperature Tf and the annealing point Ta is Tf?(Ta+5), and when the plate thickness h of glass is 7×10?4 m or more, the displacement at the load point during the load applying time period is 78 ?m or less: Dimensionless index=load F×load applying time period/(average viscosity ?×plate thickness h2).

Abstract: There is provided a tempered glass plate, wherein a thickness of the tempered glass plate is less than or equal to 2.7 mm, wherein on a surface of the tempered glass plate, a plurality of stress marks are formed, wherein a distance between closest stress marks of the plurality of stress marks is less than or equal to 20 mm, wherein the surface of the tempered glass plate includes a first virtual circle that is formed by connecting points that are separated from a center of one of the plurality of stress marks by 2.5 mm, wherein the tempered glass plate includes a non elastic-wave region that is not affected by an elastic-wave generated during fracturing, and wherein, in the non elastic-wave region, an average number of cracks that exist in the first virtual circle is greater than or equal to 3.4.

Abstract: To provide a tempered glass sheet having a thickness of from 1.8 to less than 2.5 mm, which is capable of satisfying the fragmentation quality and impact strength quality required for windowpanes for automobiles. A tempered glass sheet having a first surface, a second surface opposed to the first surface and a side surface connecting the first and second surfaces, and having a thickness of from 1.8 to less than 2.5 mm, wherein at the first surface, the average value of the surface compressive stress is within a range of from 100 to 160 MPa, and the average value of the surface strength is within a range of from 220 to 400 MPa.

Abstract: To provide laminated glass excellent in the quality and the cost, in which two glass plates differing in the plate thickness can easily be bent with good accuracy. Laminated glass 60 comprising a plurality of glass plates 12 and 14 bent into a predetermined shape, and an interlayer 40 interposed between the plurality of glass plates 12 and 14, at least two glass plates 12 and 14 among the plurality of glass plates 12 and 14 differing in the plate thickness, wherein the two glass plates 12 and 14 differing in the plate thickness have different glass compositions, and at an optional temperature between the annealing point and the softening point of the thick glass plate 12, the thick glass plate 12 has a lower viscosity than the thin glass plate 14.

Abstract: Provided is an apparatus for measuring a level of molten metal which has a simple structure and is highly robust against a change in level at a local portion of the surface of molten metal. The apparatus for measuring a level of molten metal according to a first aspect of the present invention is an apparatus which measures a level of molten metal in a mold. The apparatus includes an omnidirectional transmitting antenna; an omnidirectional receiving antenna; and a signal processor. The apparatus measures the level of molten metal in the mold using electromagnetic wave in ultra-high frequency range emitted into the mold by the omnidirectional transmitting antenna.

Abstract: A laminated glass production method includes bending multiple glass plates into a desired shape by heating the glass plates to near a softening point, stacking the bent glass plates in layers with an interlayer interposed therebetween, and forming laminated glass by bonding the glass plates and the interlayer stacked in layers by applying pressure. At least two of the glass plates composing the laminated glass have different thicknesses. Of the two glass plates having different thicknesses, the thicker glass plate has a lower viscosity than the thinner glass plates at a temperature between the annealing point and the softening point of the thicker glass plate. Forming the laminated glass includes forming an uneven temperature distribution on a principal surface of each of the glass plates.

Abstract: To provide tempered glass which is thin and can be produced by common air-quench tempering without requiring a special production facility, and untreated glass for such tempered glass. The tempered glass is obtainable via a heating step and a cooling step. The heating step is a step of applying heat treatment to glass to be treated, of which the glass transition point is from 500 to 600° C. and the maximum value of the thermal expansion coefficient (?max) between the glass transition point and the yield point is at least 430×10?7/° C. The cooling step is a step of applying air-quenching treatment to the glass to be treated.

Abstract: The present invention provides a method for manufacturing a small-sized physically-strengthened glass sheet having excellent design properties, a structure using the small-sized physically-strengthened glass sheet, and a method for manufacturing the structure. In the cutting step in the method for manufacturing a physically-strengthened glass sheet of the present invention, the intermediate layer 17 is locally heated at a temperature not higher than the annealing point thereof with a laser beam 20 to thereby locally generate a tensile stress smaller than the internal residual tensile stress CT or a compressive stress in the intermediate layer 17 to control the propagation speed of the crack 30 due to the internal residual tensile stress.

Abstract: A front glass plate for a stacked structure includes greater than or equal to 5 mol % of Al2O3, in terms of an oxide, as a component, 50% crack initiation load of the front glass plate being greater than or equal to 0.5 kg.

Abstract: The method for tempering a glass sheet of the present invention comprises a heating step of heating the glass sheet to a temperature close to the softening point of the glass sheet, a quenching step of blowing a cooling medium to both surfaces in the thickness direction of the heated glass to cool it, and a pre-quenching step between the heating step and the quenching step and further has an internal heating substep of selectively heating the vicinity of the center portion in the thickness direction of the glass sheet at least in the quenching step, to create such a state that when the temperature at the center portion in the thickness direction of the glass sheet is close to the tempering point, the temperature at the surfaces in the thickness direction of the glass sheet is not higher than the annealing point.

Abstract: Provided is an apparatus for measuring a level of molten metal which has a simple structure and is highly robust against a change in level at a local portion of the surface of molten metal. The apparatus for measuring a level of molten metal according to a first aspect of the present invention is an apparatus which measures a level of molten metal in a mold. The apparatus includes an omnidirectional transmitting antenna; an omnidirectional receiving antenna; and a signal processor. The apparatus measures the level of molten metal in the mold using electromagnetic wave in ultra-high frequency range emitted into the mold by the omnidirectional transmitting antenna.

Abstract: To provide laminated glass excellent in the quality and the cost, in which two glass plates differing in the plate thickness can easily be bent with good accuracy. Laminated glass 60 comprising a plurality of glass plates 12 and 14 bent into a predetermined shape, and an interlayer 40 interposed between the plurality of glass plates 12 and 14, at least two glass plates 12 and 14 among the plurality of glass plates 12 and 14 differing in the plate thickness, wherein the two glass plates 12 and 14 differing in the plate thickness have different glass compositions, and at an optional temperature between the annealing point and the softening point of the thick glass plate 12, the thick glass plate 12 has a lower viscosity than the thin glass plate 14.

Abstract: Disclosed is a distance measuring apparatus which includes: a first pulse generating means (135) which generates reference signals; a second pulse generating means (137) which generates subject detection signals; a time measuring section (139) which measures a period of time from a time when a first pulse is generated to a time when a second pulse is generated; a first phase detecting section (141) which detects the first phase of a signal received using a signal at a first frequency; a second phase detecting section (163) which detects the second phase of a signal received using a signal at a second frequency; and a distance calculating section (165) which calculates the distance to the subject on the basis of output from the time measuring section, the first phase detecting section and the second phase detecting section.

Abstract: A method and an apparatus for annealing a glass sheet, which can sufficiently reduce I/T formed in the glass sheet, are provided. In the method for annealing a glass sheet G of the present invention, in a state that a heated and bent glass sheet G is placed on a forming mold 16, first, a region of the glass sheet G to be lifted up is cooled by cooling devices 20, 22, to make the temperature of the region to be lifted up to be a temperature of at most the strain point. Next, in this state, a lift-up member 36 is operated to lift up the region of the glass sheet G to be lifted up, by rods 38, to separate the glass sheet G from the forming mold 16.

Abstract: The apparatus according to the present invention is an apparatus for measuring width direction end position of a strip which passes through an enclosed space surrounded by a plurality of surfaces. The apparatus includes an antenna section which emits electromagnetic waves toward the width direction end and receives the electromagnetic waves reflected by the width direction end; a signal processing section for determining a position of the width direction end using the reflected electromagnetic waves; and a scattering plate for scattering electromagnetic waves which are incident thereon, wherein the antenna section is installed on a first surface which faces the width direction end a position of which is to be determined and the scattering plate is installed on a second surface which faces the first surface.

Abstract: A glass sheet for a laminated glass to be fit into a frame of an automobile in a flash-mount structure, that is a glass sheet having a good strength, is provided. In the glass sheet of the present invention, the maximum value of the plane compressive stress on the edge of the glass sheet is at least 10 MPa and at most 18 MPa, and the maximum value of the plane compressive stress inside from the edge of the glass sheet is at most 2.4 MPa.

Abstract: A glass sheet for a laminated glass to be fit into a frame of an automobile in a flash-mount structure, that is a glass sheet having a good strength, is provided. In the glass sheet of the present invention, the maximum value of the plane compressive stress on the edge of the glass sheet is at least 10 MPa and at most 18 MPa, and the maximum value of the plane compressive stress inside from the edge of the glass sheet is at most 2.4 MPa.

Abstract: A method and an apparatus for annealing a glass sheet, which can sufficiently reduce ITT formed in the glass sheet, are provided. In the method for annealing a glass sheet G of the present invention, in a state that a heated and bent glass sheet G is placed on a forming mold 16, first, a region of the glass sheet G to be lifted up is cooled by cooling devices 20, 22, to make the temperature of the region to be lifted up to be a temperature of at most the strain point. Next, in this state, a lift-up member 36 is operated to lift up the region of the glass sheet G to be lifted up, by rods 38, 38 . . . , to separate the glass sheet G from the forming mold 16.

Abstract: The present invention provides an air-cooling/tempering device and an air-cooling/tempering method for a glass sheet, which are capable of uniformly air-cooling and tempering a glass sheet as a whole without being affected by the pitch between adjacent rollers and a roller diameter. The roller body of each roller forming the air-cooling/tempering device includes a rotary shaft formed of a guide shaft permitting a bendable action; and a plurality of ring rollers carried on the guide shaft and engaged and coupled with adjacent ring rollers; and disc rollers fixedly carried at intervals on ring rollers so as not to overlap the disc rollers on an adjacent roller with respect to a conveying direction of the glass sheet. Further, outlet modules are disposed on ring rollers between adjacent disc rollers through bearings so as to be rotatable with respect to the rotary shaft.

Abstract: The present invention provides an air-cooling/tempering device and an air-cooling/tempering method for a glass sheet, which are capable of uniformly air-cooling and tempering a glass sheet as a whole without being affected by the pitch between adjacent rollers and a roller diameter. The roller body of each roller forming the air-cooling/tempering device includes a rotary shaft formed of a guide shaft permitting a bendable action; and a plurality of ring rollers carried on the guide shaft and engaged and coupled with adjacent ring rollers; and disc rollers fixedly carried at intervals on ring rollers so as not to overlap the disc rollers on an adjacent roller with respect to a conveying direction of the glass sheet. Further, outlet modules are disposed on ring rollers between adjacent disc rollers through bearings so as to be rotatable with respect to the rotary shaft.