Abstract: A method for melting inorganic materials, preferably glasses and glass-ceramics, in a melting unit with cooled walls is provided. The method includes selecting the temperature of at least one region of the melt is selected in such a way as to be in a range from Teff?20% to Teff+20%, where the temperature Teff is given by the temperature at which the energy consumption per unit weight of the material to be melted is at a minimum, with the throughput having been selected in such a way as to be suitably adapted to the required residence time.

Abstract: The device for homogenizing a glass melt has a melt receptacle and at least one stirring device arranged in the melt receptacle. Each stirring device consists of a stirrer shaft and stirrer blades extending toward an inside wall of the receptacle, which are configured to produce an axial feed of the glass melt in an inner stirring region between the stirrer shaft and front ends of the stirrer blades. The melt receptacle and the stirring device are configured so that a melt flow caused by the axial feed, which is opposite to the axial feed, seals a gap formed between the inside wall and the front ends of the stirrer blades, so that the glass melt cannot flow directly through the gap to a lower axial end of the inner stirring region. The invention also encompasses a method of homogenizing a glass melt.

Abstract: The invention relates to a device for homogenizing a glass melt in a melt receptacle, wherein at least one stirring device is disposed in a melt receptacle, which comprises a stirrer shaft and a plurality of stirrer blades, and wherein a gap (16) is formed between a wall region of the melt receptacle and the stirrer blades. According to the invention, the respective stirring device causes an axial feed action in an inner stirring region between the stirrer shaft and the stirrer blades in order to feed the melt in the stirring region along the stirrer shaft. A melt flow brought about by the axial feed action seals the gap against direct passage of the melt. According to the invention, a very high gap width can be achieved, thus preventing the abrasion of materials in the region of the marginal gap. This also reduces the complexity required for adjusting the device. According to the invention, a high level of homogenization can be achieved regardless of the entry point of the inhomogeneities.

Abstract: In the method of making a monocrystalline or polycrystalline semiconductor material semiconductor raw material is introduced into a melting crucible and directionally solidified using a vertical gradient freeze method. The molten material trickles downward, so that the raw material that has not yet melted gradually slumps in the melting crucible. The semiconductor raw material is replenished from above onto a zone of semiconductor raw material which has not yet melted or is not completely melted to at least partly compensate for shrinkage of the raw material and to raise the filling level. To reduce the melting time and influence the thermal conditions in the system as little as possible, the semiconductor raw material to be replenished is heated to a temperature below its melting temperature and introduced into the crucible in the heated state.

Abstract: The invention relates to an optical hybrid lens. According to the invention, the lens consists of a substrate (1) that consists of a ceramic having a predetermined shape and at least another material (2), which covers a surface of the substrate (1) at least in certain sections in order to form a lens surface. Use of an optical ceramic as a material enables an additional degree of freedom for adjusting the imaging properties of the hybrid lens. The optical ceramic may have a high refractive index and a low dispersion. The other material can be a material that can be deformed or recast at temperatures that are low in comparison to those of the optical ceramic. In particular the other material can be a low-TG glass or a polymer. The other material is directly applied onto the substrate without a further surface finishing being necessarily required. Other aspects of the invention relate to an optical lens group, an optical image acquisition device, and a process for manufacturing a hybrid lens.

Abstract: The present invention relates to the use of lead-free and phosphate-containing glasses, preferably colored and filter glasses which absorb light in the infrared region (IR-region), in a precision molding process. Preferably, the content of fluorine in the glass is low. Advantageously, so optical constituents can be produced without finishing, such as for example lenses for digital cameras. By the use according to the present invention, also other optical constituents can be produced which can be directly used for a corresponding technical purpose. For an advantageous use, the optical constituents produced by precision molding can be used in the fields imaging, projection, telecommunications, optical communications engineering and laser technology.

Abstract: The device for homogenizing a glass melt has at least one stirring device, which includes a rotatable stirrer shaft (10) and stirrer paddles (11, 11?, 11?). The stirrer paddles are arranged at intervals from each other along the stirrer shaft to produce an essentially axially oriented conveying effect on the glass melt. To improve homogenization while simultaneously saving on noble metal material, the stirrer paddles (11, 11?, 11?) are each provided with a built-in element (11E). The built-in element (11E) has an edge (11K), which extends from the stirrer shaft (10) in a radial direction (R) along a rear paddle area (11B) with an edge length which is less by a specified distance (X) than the length (L) of the paddle area (11B) in a radial direction (R). These built-in elements provide a marked reduction in bubble formation.

Abstract: The invention relates to a method and to a device for homogenizing a glass melt in a melt receptacle, wherein at least one stirring device (10, 11) is disposed in the melt receptacle, which comprises a stirrer shaft (10) and a plurality of stirrer blades (11), and wherein a gap (16) is formed between a wall region of the melt receptacle (2) and the stirrer blades (11). According to the invention, the respective stirring device causes an axial feed action in an inner stirring region (12) between the stirrer shaft (10) and the stirrer blades (11) in order to feed the melt in the stirring region along the stirrer shaft (10). A melt flow brought about by the axial feed action seals the gap (16) against direct passage of the melt. According to the invention, a very high gap width can be achieved, thus preventing the abrasion of materials in the region of the marginal gap. This also reduces the complexity required for adjusting the device.

Abstract: The apparatus (300) for feeding, homogenizing, and conditioning a high viscosity glass melt for manufacturing display glass has a stirring device (110, 406), an upstream connecting part (100, 400) that connects the stirring device (110, 406) to an upstream melting and/or refining unit, and a downstream connecting part (120, 420) that connects the stirring device (110, 406) to a downstream forming or shaping device. Wall material and base material of the first and connecting parts and the stirring device (110, 406) coming in contact with the glass melt are made from a zirconium-dioxide-containing fire-resistant material containing a large amount, preferably more than 85 wt. %, of zirconium dioxide. A method of operating the apparatus to make display glass is also described.

Abstract: The invention relates to an optical hybrid lens. According to the invention, the lens consists of a substrate (1) that consists of a ceramic having a predetermined shape and at least another material (2), which covers a surface of the substrate (1) at least in certain sections in order to form a lens surface. Use of an optical ceramic as a material enables an additional degree of freedom for adjusting the imaging properties of the hybrid lens. The optical ceramic may have a high refractive index and a low dispersion. The other material can be a material that can be deformed or recast at temperatures that are low in comparison to those of the optical ceramic. In particular the other material can be a low-TG glass or a polymer. The other material is directly applied onto the substrate without a further surface finishing being necessarily required. Other aspects of the invention relate to an optical lens group, an optical image acquisition device, and a process for manufacturing a hybrid lens.

Abstract: The invention relates to a method for producing a monocrystalline or polycrystalline semiconductor material by way of directional solidification, wherein lumpy semiconductor raw material is introduced into a melting crucible and melted therein and directionally solidified, in particular using the vertical gradient freeze method. In order to prevent contamination and damage, the semiconductor raw material is melted from the upper end of the melting crucible. The molten material trickles downward, so that semiconductor raw material which has not yet melted gradually slumps in the melting crucible. In this case, the additional semiconductor raw material is replenished to the melting crucible from above onto a zone of semiconductor raw material which has not yet melted or is not completely melted, in order at least partly to compensate for a volumetric shrinkage of the semiconductor raw material and to increase the filling level of the crucible.

Abstract: A heating apparatus for the conductive heating of melts, in particular for the rapid melting-down, refining and/or conditioning of melts, is provided. The heating apparatus includes at least one electrode, as well as a first cooling system with a cooling power, which can be set and/or controlled variably.

Abstract: The invention relates to a method and a device for homogenizing a glass melt using at least one stirring means which is respectively arranged in a stirring vessel having an inlet (4) and an outlet (5), the respective stirring means having a plurality of stirrer blades (11, 20, 21) arranged spaced apart from one another along a common stirrer shaft (10). According to the invention, the stirring means and/or the device is configured in such a way that a net conveying effect of the stirring means overall from the inlet to the outlet is substantially imperceptible. The conveying effect of the stirring means overall from the inlet (4) to the outlet (5) is caused by the positioning of the stirring blades (11, 20, 21), by the geometric shape thereof and/or by the angular position of the stirring blades in the circumferential direction of the stirrer shaft (10).

Abstract: The invention relates to a method and to a device for homogenizing a glass melt in a melt receptacle, wherein at least one stirring device (10, 11) is disposed in the melt receptacle, which comprises a stirrer shaft (10) and a plurality of stirrer blades (11), and wherein a gap (16) is formed between a wall region of the melt receptacle (2) and the stirrer blades (11). According to the invention, the respective stirring device causes an axial feed action in an inner stirring region (12) between the stirrer shaft (10) and the stirrer blades (11) in order to feed the melt in the stirring region along the stirrer shaft (10). A melt flow brought about by the axial feed action seals the gap (16) against direct passage of the melt. According to the invention, a very high gap width can be achieved, thus preventing the abrasion of materials in the region of the marginal gap. This also reduces the complexity required for adjusting the device.

Abstract: The optical elements are made from an opto-ceramic material that is characterized by high density, transparency for visible light and IR, high refractive index, high Abbe number and outstanding relative partial dispersion. Mixed oxides are sintered to obtain the opto-ceramic material. The mixed oxides contain zirconium oxide and hafnium oxide mixed with one or more oxides of yttrium, scandium, lanthanide elements, and optionally mixed with one or more of SiO2, Na2O, and TiO2. Alternatively the mixed oxides contain zirconium oxide and hafnium oxide mixed with CaO and/or MgO and optionally mixed with one or more of SiO2, Na2O, and TiO2. In addition, the mixed oxides can also include one or more oxides of Al, Ga, In, and Sc; optionally one or more oxides of yttrium, some lanthanide elements; and optionally one or more of SiO2, Na2O, MgO, CaO, and TiO2.

Abstract: The apparatus for reduced-pressure refining of a glass melt includes a refining bank formed so that a reduced pressure is generated by a glass flow in it. The refining bank has a component, which is made from a refractory metal or refractory alloy acting as glass-contact material. The refractory metal or alloy contains molybdenum, tungsten, tantalum, and/or hafnium. The device of the present invention includes a protective gas reservoir for a protective gas and an automatically operating valve connecting the reservoir with the refining bank so that an inner side of the component that would otherwise be exposed when a pressure rise or a falling glass melt column occurs is protected from oxidation by the protective gas. A process for using the device during refining of the glass melt is also part of the invention.

Abstract: The optical elements are made from an opto-ceramic material that is characterized by high density, transparency for visible light and IR, high refractive index, high Abbe number and outstanding relative partial dispersion. Mixed oxides are sintered to obtain the opto-ceramic material. The mixed oxides contain zirconium oxide and hafnium oxide mixed with one or more oxides of yttrium, scandium, lanthanide elements, and optionally mixed with one or more of SiO2, Na2O, and TiO2. Alternatively the mixed oxides contain zirconium oxide and hafnium oxide mixed with CaO and/or MgO and optionally mixed with one or more of SiO2, Na2O, and TiO2. In addition, the mixed oxides can also include one or more oxides of Al, Ga, In, and Sc; optionally one or more oxides of yttrium, some lanthanide elements; and optionally one or more of SiO2, Na2O, MgO, CaO, and TiO2.

Abstract: In a process for the production of flat, particularly float glass that can be converted into glass ceramic, a liquid film consisting in particular of the float bath metal is formed between the wetback tile, and optionally the restrictor tiles, and the glass stream. The tiles preferably consist of a porous material through the pores of which is pressed the liquid for creating the film.

Abstract: The invention relates to an optical hybrid lens. According to the invention, the lens consists of a substrate (1) that consists of a ceramic having a predetermined shape and at least another material (2), which covers a surface of the substrate (1) at least in certain sections in order to form a lens surface. Use of an optical ceramic as a material enables an additional degree of freedom for adjusting the imaging properties of the hybrid lens. The optical ceramic may have a high refractive index and a low dispersion. The other material can be a material that can be deformed or recast at temperatures that are low in comparison to those of the optical ceramic. In particular the other material can be a low-TG glass or a polymer. The other material is directly applied onto the substrate without a further surface finishing being necessarily required. Other aspects of the invention relate to an optical lens group, an optical image acquisition device, and a process for manufacturing a hybrid lens.

Abstract: The invention relates to an optical lowpass filter that has a plurality of light guiding optical fibers, and to a method for producing such an optical lowpass filter.