Abstract: In an annealing zone (3) of a glass sheet producing method, a curved portion (5) is formed by curving a glass ribbon (G) in a width direction, and a concavo-convex direction in a front and back direction of the curved portion (5) is reversed at least between an upper side and a lower side of a part of a region in the width direction of the glass ribbon (G). Therefore, a bending resistance in an upper and lower direction of the glass ribbon (G) and a bending resistance in the width direction of the glass ribbon (G) are increased.

Abstract: A method for bending a sheet is described. The method includes the following steps: a) at least one sheet is inserted into a pre-bending ring with a movable bending ring holder, the movable bending ring holder is moved into a furnace and the at least one sheet is heated to softening temperature and is pre-bent to 5% to 50% of a final edge bending, b) the at least one sheet is lifted by means of a suction device and is bent further, beyond the bending obtained in the pre-bending ring, c) the at least one sheet is laid down by means of the suction device in a final-bending ring on the movable bending ring holder and is bent to the final edge bending, and an area pre-bending of the at least one sheet is performed by means of thermal irradiation, d) the at least one sheet is lifted out of the final-bending ring by means of a second suction device, pressed against an opposing mould and bent, and the at least one sheet is laid down on the final-bending ring and the at least one sheet is cooled down.

Abstract: In a heating drawing, a base material glass plate is heated and softened in a heating furnace, and drawn to a desired thickness to form a glass strip. In the heating drawing, the base material glass plate is heated so that the base material glass plate has a U-shaped temperature distribution in a width direction. Such process can be realized through heating by a heating element which has a non-heating portion at a position opposite to a central portion of the base material glass plate in the width direction and a heating portion on both sides of the non-heating portion. Thus provided is a method of manufacturing a glass strip, the method includes heating and softening the base material glass plate, and drawing the base material glass plate to a desirable thickness to form a glass strip, and is capable of manufacturing a thin, rod-like glass strip with an excellent flatness.

Abstract: Disclosed are methods for compensating the varying weight of a glass ribbon the glass ribbon is drawn from a molten glass forming material, and an apparatus therefore. The weight compensating apparatus is configured to apply a force to the glass ribbon that is inversely proportional to the weight of the glass ribbon such that as the glass ribbon weight increases, the force applied to the glass ribbon by the weight compensating device decreases.

Abstract: A manufacturing apparatus for a thin glass sheet includes a forming member main body configured to form the thin glass sheet by fusing together, at a lower end portion of the forming member main body, streams of molten glass, which have overflown from an overflow trough to both sides of the forming member main body, under a state in which the streams of the molten glass are caused to flow down along outer surface portions having a substantially wedge shape. The manufacturing apparatus also includes a pair of covering members fitted onto both widthwise end portions of the forming member main body, respectively, the pair of covering members forming restricting wall portions for restricting widthwise spread of the streams of the molten glass flowing down along the outer surface portions of the forming member main body.

Abstract: Managing pressure within a thickness-control-zone (muffle door) housing (20) relative to pressures in a glass-making machine enclosure (60) and an upper chamber (40)—that is disposed outside the enclosure—so as to minimize or control undesired airflows that would adversely affect thickness (9) of glass ribbon (8). According to one pressure-management technique, the pressure at a location (25) in the housing (20) is managed so as to be less than the pressure at a location (65) that is within the enclosure (60) as well as both outside and adjacent to the housing. In the event of a leak, as by a crack or unintended opening in the housing, for example, this pressure difference reduces or prevents airflow toward the ribbon and, thereby, undesired thickness variation in the ribbon. According to a second pressure-management technique, the pressure at location (25) is managed so as to be greater than the pressure in the upper chamber.

Abstract: After a glass film ribbon is formed while allowing a glass to descend, the glass film ribbon is annealed while allowing the glass film ribbon to descend in an annealer to remove an internal strain. Then, when the glass film ribbon having a thickness at a center portion excluding both widthwise ends of 300 ?m or less is cut, after processing in the annealer is executed and before a cutting step is executed, main tensile rollers that play a role as principal tensile rollers hold the descending glass film ribbon and are driven to rotate, to thereby provide at least the glass film ribbon in the annealer with tension in a vertical direction.

Abstract: Methods for controlling thickness variations across the width of a glass ribbon (104) are provided. The methods employ a set of thermal elements (106) for locally controlling the temperature of the ribbon (104). The operating values for the thermal elements (106) are selected using an iterative procedure in which thickness variations measured during a given iteration are employed in a mathematical procedure which selects the operating values for the next iteration. In practice, the method can bring thickness variations of glass sheets within commercial specifications in just a few iterations, e.g., 2-4 iterations.

Abstract: Raised features are formed on a transparent substrate having absorption of less than about 20% within a processing wavelength range. A portion of the substrate is irradiated with a light beam to increase the absorption of the irradiated portion of the substrate. Continued irradiation causes local heating and expansion of the substrate so as to form a raised feature on the substrate surface.

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 invention relates to a method for obtaining an external covering of a photovoltaic device, said covering being constituted by a glass substrate having texturing in the form of at least one row of grooves that are mutually parallel and preferably spaced by a regular distance d, said method being characterized in that there is used, for the impression of said texturing, texturing means incorporating reliefs whose spacing is different from the distance d between two rows of grooves on the glass substrate. The invention also relates to a substrate or to a photovoltaic module incorporating a substrate that can be obtained by application of the preceding method.

Abstract: A process and apparatus for precision glass roll forming a supply of molten glass at a glass temperature of 1000° C. or higher with a pair of hot forming rolls having a surface temperature of about 500° C. or higher located vertically below the glass feed. The forming rolls thin the supplied stream of molten glass to produce a formed glass ribbon. A pair of cold sizing and texturing rolls maintained at a surface temperature of about 400° C. or lower or 300° C. or lower is located vertically below the forming rolls. The sizing and texturing rolls thin and texture the formed glass ribbon to produce a sized glass ribbon having a desired texture, thickness and thickness uniformity. The sized and textured glass ribbon may have a thickness of 1 mm or less that varies in thickness by no more than +/?0.025 mm.

Abstract: A sheet glass that has a side surface with an average surface roughness equal to or less than 0.2 ?m is provided. Furthermore, a method of manufacturing a sheet glass is provided that includes processing a base-material glass sheet to obtain a sheet glass that has a side surface with an average surface roughness equal to or less than 0.2 ?m. Moreover, a method of manufacturing a sheet glass is provided that includes processing a base-material glass sheet so that an average surface roughness of a side surface becomes equal to or less than a predetermined value according to a section modulus of the sheet glass that is to be manufactured.

Abstract: Glass substrates and methods for forming glass substrates are disclosed. The glass substrates include a planar A-side surface having a surface roughness Ra1 of less than 0.5 nm and a planar B-side having a surface roughness Ra2 wherein the ratio Ra2:Ra1 is greater than or equal to about 1.5. A plurality of texturing features are formed in the B-side surface. The plurality of texturing features have a peak-to-valley height H such that 0.05 ?m?H?3.75 ?m. The texturing features are distributed in the B-side surface such that a center-to-center pitch P between adjacent texturing features is at least 1.5 mm in at least one direction. The plurality of texturing features are formed in the B-side surface while the glass substrate is at a temperature T1, wherein 600° C.?T1?1200 ° C. and a viscosity of the glass substrate is from greater than 150,000 Poise and less than 1013 Poise.

Abstract: A method for manufacturing a glass substrate by a fusion process includes flowing fused glass into a fusion pipe, and gradually cooling and solidifying the fused glass by allowing the glass to flow downward from the fusion pipe. An asperity is formed on a surface of the glass substrate by fastening and pressing the glass toward a direction of thickness of the glass with a pair of transfer rollers while the glass is flowing down from the fusion pipe.

Abstract: A method of manufacturing a glass blank for a substrate for an information recording medium, the method including steps of: cutting out a gob of a glass material from a molten glass material by cutting the molten glass material discharged from a glass material outlet at a predetermined timing; causing the gob of the glass material to fall downwardly; pinching and pressing the gob of the glass material by a press unit having a pair of molds, the molds' surfaces facing to each other being press surfaces which are planes without an unevenness, so as to contact the falling gob of the glass material only to the press surfaces; and forming a circular flat plate-shaped glass blank having a target flatness as a glass substrate for a magnetic disk such that a ratio between a diameter and a thickness of the glass blank is within a range of from 50:1 to 150:1, from the gob of the glass material.

Abstract: Methods for controlling thickness variations across the width of a glass ribbon (104) are provided. The methods employ a set of thermal elements (106) for locally controlling the temperature of the ribbon (104). The operating values for the thermal elements (106) are selected using an iterative procedure in which thickness variations measured during a given iteration are employed in a mathematical procedure which selects the operating values for the next iteration. In practice, the method can bring thickness variations of glass sheets within commercial specifications in just a few iterations, e.g., 2-4 iterations.

Abstract: Methods for controlling the bow (shape) of a vertical glass ribbon (13) produced by a downdraw process are provided. The methods involve passing the ribbon (13) through a gas-filled vertical enclosure (23), e.g., a draw tower, whose bottom (31) is open to the atmosphere. The ribbon (13) acts as a septum that divides the enclosure's internal volume (29) into a first sub-volume (25) and a second sub-volume (27). Using the stack effect, a positive pressure difference is produced between the first sub-volume (25) and the second sub-volume (27) along at least a portion of the length of the enclosure (the DDZ). The edges of the ribbon (13) are constrained so that they do not move into the second sub-volume (27) over at least the DDZ. As a result, the ribbon bows with its concavity facing the first sub-volume (25) and its convexity facing the second sub-volume (27).

Abstract: Molten glass (G) is set and press-molded in a molding die (60) having dies (621A1, 621A2) corresponding to a lens array. After the molding, the molded article is removed from the molding die (60) and separated by bending at a bend-separation face (121C), which is a boundary part of adjacent lens arrays, so that two lens arrays are produced.

Abstract: When a synthetic quartz glass substrate is prepared from a synthetic quartz glass block, (I) the block has a hydrogen molecule concentration of 5×1017-1×1019 molecules/cm3, (II) the substrate has a hydrogen molecule concentration of 5×1015-5×1017 molecules/cm3, (III) the substrate has an in-plane variation of its internal transmittance at 193.4 nm which is up to 0.2%, and (IV) the substrate has an internal transmittance of at least 99.6% at 193.4 nm. The synthetic quartz glass substrate has a high transmittance and a uniform transmittance distribution, and is adapted for use with excimer lasers, particularly ArF excimer lasers.

Abstract: A conformable nosing device is described herein which conforms to have a bowed shape that substantially matches a bowed shape of a glass sheet and which engages the glass sheet to help minimize the motion of the glass sheet and to help reduce the stress within the glass sheet while the glass sheet is being scored and separated into individual glass sheets. In addition, the conformable nosing device can include a passive nosing device which can be controlled to further help minimize the motion of the glass sheet while the glass sheet is being scored and separated into individual glass sheets.

Abstract: There are provided a die for forming a glass substrate which does not generate cracks when the glass substrate is released from the die, in a method of manufacturing a glass substrate by forming molten glass with a pressing operation, a method of manufacturing a glass substrate using the die, a method of manufacturing a glass substrate for an information recording medium using a glass substrate manufactured by the method, a method of manufacturing an information recording medium, a glass substrate for an information recording medium, and an information recording medium. In the die for forming a glass substrate used for pressing molten glass to manufacture a glass substrate for an information recording medium, a lower die includes a die surface on which a plurality of grooves or depressions are almost uniformly formed.

Abstract: A high transmission and low iron glass is provided for use in a solar cell. The glass substrate may be patterned on at least one surface thereof. Antimony (Sb) is used in the glass to improve stability of the solar performance of the glass upon exposure to ultraviolet (UV) radiation and/or sunlight. The combination of low iron content, antimony, and/or the patterning of the glass substrate results in a substrate with high visible transmission and excellent light refracting characteristics.

Abstract: In the formation of sheet glass by the overflow downdraw process, the width of usable sheet glass is maximized by downwardly flowing edge portions of the sheet over web-like members and thereafter over extensions which intersect with and are downwardly inclined relative to the web-like members to thin edge portions of the glass flow and maintain sheet width. The extension members are preferably removably attached to the web-like members, greatly facilitating replacement of the more easily damaged extension members.

Abstract: A high transmission and low iron glass is provided for use in a photovoltaic device such as a solar cell. The glass substrate may be patterned on at least one surface thereof. In certain example embodiments, a combination of lithium oxide, antimony oxide, and salt cake is used in the glass to improve the refining conditions by lowering the melting temperature of the batch, thereby resulting in a quicker seed free time in the manufacturing process.

Abstract: A glass-ceramic plate, and production methods and apparatuses in relation to the plate. The plate is designed for example to equip a cooktop, and includes, on at least one of its faces, a differentiated surface finish formed in the body of the bare glass-ceramic plate.

Abstract: A glass-ceramic plate, a method of manufacturing a glass-ceramic plate, and hubs equipped with the glass-ceramic plate. A flat or substantially flat glass-ceramic plate includes a surface provided with pegs, the plate configured to equip a hob. At least one smooth region, free of pegs, is reserved in a location designed to come, in a mounted position, face to face with one or more elements of the hob, the blurred view of which due to the pegs must be improved.

Abstract: A glass sheet includes a first edge, an opposing, second edge, and an intermediate location between the first edge and second edge. The glass sheet has a first portion extending between the first edge and the intermediate location and a second portion extending between the intermediate portion and the second edge, wherein the first portion has a generally uniform thickness and the second portion has a varying thickness. The thickness of the second portion can either increase or decrease from the intermediate location to the second edge. A laminated transparency incorporating the glass sheet as well as a method of forming a glass ribbon having a changing thickness profile along at least a portion of the width of the ribbon are also disclosed.

Abstract: Artistic panes having flat and planar margins with laterally offset central regions and deformations, as well as devices and methods for making the same, are shown and described. Devices and assemblies for manufacturing such artistic panes incorporate support members and raised boundary members, and can incorporate masses and/or piles of powder to create various deformations in the artistic panes. Methods of manufacturing such artistic panes can incorporate slump processes, sag processes and rolling processes.

Abstract: A transparent substrate for a cover for a solar battery and a method for producing the same are presented. Hemispherical concave portions are formed in a surface of light entering side of a cover glass almost over the entire surface wherein the ratio d/D of the depth d of the central portion of each concave portion to the radius D of the opening of the concave portion is from 0.10 to 0.50 and the proportion of area occupied by a flat portion where no concave portion is formed in the surface of light entering side is not more than 40%.

Abstract: A process for fabricating a faceplate for a flat-panel display such as a field emission cathode type display is disclosed, the faceplate having integral spacer support structures. Also disclosed is a product made by the aforesaid process.

Abstract: A microstructure is formed in a viscous glass or plastic substrate by pressing a structured surface of a forming tool corresponding to a negative of the microstructure to be produced in the viscous glass or plastic substrate. After the microstructure has been formed, the forming tool is removed from the surface. In order to help form the microstructure and remove the forming tool from the substrate the forming tool has an at least partially porous base body (1) and an operative layer (2) structured with a negative structure consisting of grooves (11) extending to the porous base body (1). The forming of the microstructure in the substrate is assisted by applying suction to the porous base body (1) so that the grooves (11) fill more easily and completely with melted glass or plastic material. The removal of the forming tool after forming the microstructure is assisted by applying an overpressure to the porous body to help release the solidified glass or plastic material from the forming tool.

Abstract: A method and apparatus for manufacturing patterned glass sheets. In certain embodiments, the resulting glass sheets have a pattern defined therein which is designed so as to simulate conventional glue chipped glass sheets or antique glass. A heated glass ribbon exits a furnace or melter and proceeds through a nip defined between opposing rollers. Pressure on one or both of the rollers in the direction of the nip, combined with a glue chipped simulating pattern or antique pattern defined in an exterior surface of at least one of the rollers, causes the pattern to be transferred from the roller(s) into/onto a surface(s) of the hot glass ribbon. After being patterned, the glass ribbon is annealed and cut into a plurality of different sheets.

Abstract: A process for fabricating a face plate for a flat-panel display such as a field emission cathode type display is disclosed, the face plate having integral spacer support structures. Also disclosed is a product made by the aforesaid process.

Abstract: A process for fabricating a face plate for a flat panel display such as a field emission cathode type display is disclosed, the face plate having integral spacer support structures. Also disclosed is a product made by the aforesaid process.

Abstract: The present invention provides a method of producing patterned and/or textured glass by applying a material onto at least a portion of a glass substrate, e.g., a float glass ribbon, at or above a softening point of the material and/or the glass substrate. The material is configured to affect the surface of the glass substrate to scatter light rays. An apparatus of the invention for forming patterned glass in a float glass process includes an applicator extensible into and out of a float bath chamber above a molten metal bath. A glass article of the invention includes a first surface and a second surface spaced from the first surface. The second surface includes a patterned portion configured to scatter light rays.

Abstract: A method and apparatus is described, with which individual rectangular glass panes of thickness between 0.03 mm and 2 mm can be cut from a glass band (2) drawn vertically from a hot forming device (1) in an in-line process with reduced rejects and reduced waste. The method provides that the glass band (2) drawn vertically downward through a vertical zone is cooled below a lower cooling point of the glass and subsequently is deflected through a bending zone (3b) with a bending radius between 0.1 m and 4 m into a horizontal zone (3c) in which it is horizontally oriented. The vertical alignment of the glass band (2) in the vertical zone (3a) is continuously monitored. At least one cutting process is performed on the horizontally oriented glass band (2) in the horizontal zone (3c). The device (20) for monitoring the vertical alignment of the glass band (2) includes at least three sensors (22a, 22b, 22c; 22a′, 22b′, 22c′) that detect the glass edges These sensors can be mechanical rollers.

Abstract: The method herein shapes a thin glass article (10), as well as a thin glass interface (20, 22) between two laminated sheets (16, 18) as they seal together to form the glass article (10). This process changes the shape of the article (10) and modifies the internal interface (20, 22) at the juncture where the glass sheets (16, 18) meet to make the channels (12). As a result, the juncture is very thin and very little or no slope. The process uses the mechanical motion of a plunger combined with plunger vacuum and internal gas pressure to make these changes. The technique reduces the contact area between glass layers (16, 18). A reduced contact area can reduce the optical interference caused by the joining of two layers of glass (16, 18). The technique also makes the front surface of each channel (12) thinner. The glass thinness also allows for thinner products with substantially reduced light distortion at the juncture.

Abstract: A glass diffuser is fabricated by first producing a metal shim submaster or other high temperature resistant diffuser having a surface relief structure on one surface. A glass substrate material is heated to a suitable temperature and at least one exposed surface is thereby softened to a desired degree. The submaster diffuser, and particularly the surface relief structure, is then placed in contact with the exposed and softened glass substrate material in order to replicate the surface relief structure in the glass material. The submaster diffuser and the glass substrate are separated and then the glass is allowed to cool to form a glass diffuser.

Abstract: A method for heated mold changing at a forming station (24) is performed by apparatus (32) in a heated chamber (22) where heated glass sheets are cyclically formed. A switching station (318) is located adjacent the forming station (24). An unloading station (320) and a mold preheating station (322) are each located adjacent the switching station. An unloading cart (324) is initially movable from the loading station (320) to the switching station (318) and then to the forming station (24) to receive one or more heated molds from the forming station and is subsequently moved from the forming station back through the switching station to the unloading station to permit unloading of each heated mold. A loading cart supports a second mold or a pair of molds for heating within the mold preheating station (322) and is movable from the mold preheating station to the switching station (318) and then to the forming station for mold loading.

Abstract: A process for fabricating a face plate for a flat panel display such as a field emission cathode type display, the face plate having integral spacer support structures is disclosed. Also disclosed is a product made by the aforesaid process. The support structures are designed to be load bearing so as to prevent implosion of a planar, transparent face plate toward a parallel spaced-apart base plate when the space between the face plate and the base plate is sealed at the edges of the display to form a chamber, and the chamber is evacuated in the presence of atmospheric pressure outside the chamber. Unlike most spacer support structures proposed for such flat panel displays, the support structures are made from the same material as the substrate from which the face plate is fabricated. For a preferred embodiment of the process, a perforated laminar template is sealably sandwiched between a laminar silicate glass substrate and a manifold block to form a temporary sandwich assembly.

Abstract: On the pressing surface of a die, a first protrusion having a substantially triangular cross section and a second protrusion having a length which is greater than a width thereof and a substantially trapezoidal cross section in planes extending through both length and width dimensions thereof are provided. By press forming, a groove with a substantially V-shaped cross section to mount an optical part, and a groove with a substantially inverse-trapezoidal cross section providing an alignment marking are formed, being inverse-transferred in correspondence with the respective protrusions on one principal surface of a glass substrate. Forming such a pattern on a glass substrate produced with a die enables alignment of the glass substrate with a mask for photolithography with high accuracy.

Abstract: In bending a glass sheet, the load applied to an intermediate glass sheet can be equalized to improve the quality of a final glass sheet. For this purpose, a forming ring 1 comprises a first forming frame 15 and a second forming frame 16, and the swingable center of each of swingable frames 19, 20, which forms right and left portions of a second forming frame 16, is located at an intermediate position apart from a separation position from each of fixed frames 17, 18. By such arrangement, the intermediate glass sheet can be equally supported when the swingable frames 19, 20 are moved along the intermediate glass sheet and the intermediate glass sheet is transferred from the first forming frame 15 onto the second forming frame 16.

Abstract: A glass diffuser is fabricated by first producing a metal shim submaster or other high temperature resistant diffuser having a surface relief structure on one surface. A glass substrate material is heated to a suitable temperature and at least one exposed surface is thereby softened to a desired degree. The submaster diffuser, and particularly the surface relief structure, is then placed in contact with the exposed and softened glass substrate material in order to replicate the surface relief structure in the glass material. The submaster diffuser and the glass substrate are separated and then the glass is allowed to cool to form a glass diffuser.

Abstract: The present invention is directed to a method for forming glass articles containing enclosed channels. The method comprises the following steps: a) delivering and depositing a first length of a molten glass ribbon (18) to a surface of a mold (20) having a mold cavity (22) possessing at least one channel-forming groove (22) and a peripheral surface, wherein the first length (18) overlies the mold cavity (22) and the peripheral surface; b) allowing the first length of the molten glass ribbon (18) to substantially conform to the contour of the mold cavity (22) resulting in the formation of at least one channel in the first length of the molten glass ribbon (18); c) delivering and depositing a second length of the molten glass ribbon (26) to the exposed surface of the first length of the molten glass ribbon (18).

Abstract: A process for fabricating a face plate for a flat panel display such as a field emission cathode type display, the face plate having integral spacer support structures is disclosed. Also disclosed is a product made by the aforesaid process. The support structures are designed to be load bearing so as to prevent implosion of a planar, transparent face plate toward a parallel spaced-apart base plate when the space between the face plate and the base plate is sealed at the edges of the display to form a chamber, and the chamber is evacuated in the presence of atmospheric pressure outside the chamber. Unlike most spacer support structures proposed for such flat panel displays, the support structures are made from the same material as the substrate from which the face plate is fabricated. For a preferred embodiment of the process, a perforated laminar template is sealably sandwiched between a laminar silicate glass substrate and a manifold block to form a temporary sandwich assembly.

Abstract: A process for fabricating a face plate for a flat panel display such as a field emission cathode type display, the face plate having integral spacer support structures is disclosed. Also disclosed is a product made by the aforesaid process. The support structures are designed to be load bearing so as to prevent implosion of a planar, transparent face plate toward a parallel spaced-apart base plate when the space between the face plate and the base plate is sealed at the edges of the display to form a chamber, and the chamber is evacuated in the presence of atmospheric pressure outside the chamber. Unlike most spacer support structures proposed for such flat panel displays, the support structures are made from the same material as the substrate from which the face plate is fabricated. For a preferred embodiment of the process, a perforated laminar template is sealably sandwiched between a laminar silicate glass substrate and a manifold block to form a temporary sandwich assembly.

Abstract: The present invention is directed to a method for forming glass articles containing internal enclosed channels.

Abstract: A silica glass member shows a glassy carbon coating wherein a surface of a silica glass substrate of the silica glass member shows a mean surface roughness (R.sub.a) in a range of 0.03 .mu.m to 2 .mu.m and it is coated with a glassy carbon coating. The member is manufactured by chemically roughening the substrate to a surface roughness in the above recited range; coating the surface of the silica glass substrate with an organic raw material containing carbon, curing and thereafter carbonizing the film of the organic raw material by forming a glassy carbon coating.

Abstract: A hot rolled sheet of glass having impressions impressed in the hot glass by a roller having raised projections. The projections are pyramidal or truncated pyramidal with either a square or hexagonal base. The projections produce craters which are separated from one another by a distance smaller than a largest dimension of the craters. In a variant, non-diffusing areas are inserted adjacent to diffusing zones.