Nikon Corporation

Asahi Glass Company, Limited

Seiji Miyazaki

Kei Nara

Masamitsu Yanagihara

Tsuyoshi Narabe

Hiroshi Shirasu

Susumu Mori

Kei Maeda

Osamu Sakamoto

Kazuaki Saiki

Masami Seki

Chikao Tanaka

Hideki Koitabashi

Satoru Ohkawa

Manabu Nishizawa

Hiroshi Chiba

Tsuyoshi Naraki

Muneyasu Yokota

Kazuhiro Suzuki

Tomohide Hamada

Takahiro Murakami

Toshio Matsuura

Yukio Kakizaki

Junichiro Kase

Toshiyasu Kawaguchi

Hiroshi Kitano

Hideji Goto

Kazuhiko Hori

Yoshiyuki Katamata

Yoshio Fukami

Yoichi Hamashima

Kei Hara

Tsuyohsi Narabe

A glass-melting furnace, which suppresses the effect of exhaust gas on molten glass quality, a process for producing molten glass, and a process and apparatus for producing glass products. The glass-melting furnace containing: a raw glass material particle feed portion disposed downwardly at a furnace wall portion in an upper portion of the glass-melting furnace; a heating unit provided under the feed portion, which forms a gas phase portion for converting raw glass material particles into liquid glass particles; a flue inlet disposed on the upstream side of the gas phase portion in a flow direction of the molten glass liquid; a furnace-bottom portion, which accumulates the liquid glass particles that produce the molten glass liquid; and a discharge portion, which discharges the molten glass liquid.

Glass-melting furnace, process for producing molten glass, apparatus for producing glass products and process for producing glass products

The present invention provides a process for producing a molten glass which can produce a molten glass having a good quality, a glass-melting furnace, a process for producing glass products and an apparatus for producing glass products. While an oxygen combustion burneris rotated by a motor, glass raw material particles (not shown) are dropped into a high-temperature gas phase atmosphere produced by a flame F of the oxygen combustion burner, to be changed into liquid glass particles. By rotation of an outlet (nozzle) of the oxygen combustion burner, the falling position of the liquid glass particles, changes with time. Accordingly, generation of bubbles caused by continuous fall of the liquid glass particles in a particular position on a molten glass liquid surface is prevented. Accordingly, it is possible to produce a molten glass having a good quality with few bubbles.

Process for producing molten glass, glass-melting furnace, process for producing glass products and apparatus for producing glass products

Glass raw material particles are dropped from an oxygen combustion burner, and the glass raw material particles are heated by a flame F of an oxygen combustion burnerand a thermal plasma P, to melt the particles. Liquid glass particlesproduced by the melting fall downwardly in a melting tank, and fall on a surface of a molten glass liquid G in the melting tank. Then, an upper layer Gof the molten glass liquid G is heated by electrodesof a heating apparatusprovided in the melting tank. By this method, air and residual gas generated in the molten glass liquid G and the liquid glass particlesfallen onto the surface of the molten glass liquid G, become bubbles, surface and are smoothly discharged.

To provide an alkali free glass which is suitable as a glass substrate for LCD and has few defects of bubbles and an undissolved starting material, and a process for producing an alkali free glass which can readily lower the defects in bubbles and an undissolved starting material. An alkali free glass with a matrix composition comprising SiO, AlO, BO, MgO, CaO, SrO and BaO and containing substantially no alkali metal oxide, of which the temperature at which the viscosity becomes 10dPa&#xb7;s, is at most 1,600&#xb0; C. and which contains sulfur in an amount of from 0.001 to 0.1% as calculated as SO, as represented by the mass percentage, per 100% of the total amount of the above matrix composition, and a process for producing a glass which comprises preparing a starting material and melting it so that a sulfate be incorporated to the starting material in an amount of from 0.01 to 5% as calculated as SO, as represented by the mass percentage, per 100% of the total amount of the above matrix composition.

Alkali free glass and process for its production

Provided is a crystallized glass spacer for a field emission display resistant to charging with application of an electric field and resistant to chipping or cracking thanks to high fracture toughness. An SiO&#x2014;TiO-based glass is subjected to a reduction and crystallization heat treatment at 600-900&#xb0; C. in a hydrogen atmosphere or in a mixed atmosphere of hydrogen and nitrogen, to obtain a crystallized glass spacer for FED consisting essentially of, in molar percentage, SiO: 20-50%, TiO: 25-45%, MgO+CaO+SrO+BaO+ZnO: 20-50%, BO+AlO: 0-10% and ZrO: 0-10%, and containing as a principal crystal at least one crystal selected from BaTiO-based crystals (X=0.8-1.5), BaTiSiO-based crystals and TiO-based crystals.

Crystallized glass spacer for field emission display and method its production

Scanning type exposure apparatus and exposure method

In order to provide a search alignment method capable of high-speed alignment without a relative movement between an alignment system and a substrate, an alignment mark is constituted by a plurality of element marks having shapes different from each other, the plurality of element marks are provided in such a manner that each two of them has a gap a little shorter than the size of the field of view of the alignment system therebetween, and if even one of the element marks constituting the alignment mark comes into the field of view of the alignment system, said element mark is identified out of all of said element marks, whereby the position of the entire alignment is measured from the position of said one element mark. Therefore, if the alignment mark is moved in a range wider than the field of view of the alignment system, it is possible to detect the position of the alignment mark by one measurement.

Alignment method, exposure method, and exposure apparatus

Positional discrepancies of images of segmental areas, which are caused by stretching of a substrate in the Y direction, are corrected by changing magnifications of respective projection optical systems and inclinations of parallel plane glass pieces with respect optical axes. After that, positional discrepancies of the images after the correction are accurately detected by using a calibration system for the projection optical systems. Thus it is possible to confirm whether or not the positional discrepancies are accurately corrected. If the correction is insufficient as a result of the confirmation, at least one of correction of the magnifications of the respective projection optical systems and shift of the images projected through the respective projection optical systems onto the substrate is executed again so that amounts of the positional discrepancies are sufficiently small. On the other hand, the positional discrepancy can be easily determined by storing positional information and a detected signal concerning an image formed by a projection optical system in synchronization with a clock, followed by signal processing.

Projection exposure apparatus, method for correcting positional

A glass substrate for plasma display panel, which has a spectral transmittance of at least 87% in the range of from 400 nm to 700 nm at a thickness in the range of from 1.5 to 3.5 mm.

Glass substrate for plasma display panel

In each of the second and subsequent heat treatments, in a case where a glass substrate shrinks by heat treatment at the same average cooling rate as the average cooling rate in the immediately preceding heat treatment, the average cooling rate is set to be larger than that in the immediately preceding heat treatment, and inversely, in a case where the glass substrate extends, the average cooling rate is set to be smaller than that in the immediately preceding heat treatment.

Method for heat-treating a glass substrate

Alignment method utilizing plurality of marks, discriminable from each

A pair of reference plates is so arranged as to have a predetermined positional relationship on a carriage that integrally holds a mask and a photosensitive substrate such that the mask and the photosensitive substrate oppose each other on two sides of a projecting optical system. By periodically detecting the positional relationship between the reference plates in the optical axis direction, a variation with time occurring in the detection characteristics of position detecting devices is detected. Both stable image formation characteristics and a high throughput are realized by correcting a driving signal to be supplied to a driving device in accordance with the detected variation.

Exposure apparatus

Alignment between a mask and a photosensitive substrate is performed using a first reference mark formed on the mask and a second reference mark formed on the photosensitive substrate. After that, the mask and the photosensitive substrate are relatively moved, so that an image of one of a light-shielding pattern and a light-transmitting pattern formed at a position different from the first reference mark on the mask is formed on the second reference mark on the photosensitive substrate. Then, a circuit pattern formed on the mask is transferred onto the photosensitive substrate, and a partial region including the second reference mark is exposed with the image of one of the light-shielding pattern and the light-transmitting pattern.

Exposure method using reference marks on both the mask and the substrate

A scanning exposure apparatus is arranged to illuminate a mask, to project an image of the mask through a projection optical system onto a photosensitive substrate, and to move the mask and the photosensitive substrate relative to the projection optical system, thereby effecting exposure of an entire surface of the mask on the photosensitive substrate, and the exposure apparatus comprises a position detector which detects a relative positional relation between the mask and the photosensitive substrate; a memory which stores positional information obtained by the position detector; a position correcting device which corrects the relative positional relation between the mask and the photosensitive substrate, based on the positional information read out from the memory device; and a controller which makes the position detector detect the relative positional relation between the mask and the photosensitive substrate while the mask and the photosensitive substrate are carried past a projection region of the projection optical system to an exposure start position, and makes the position correcting device correct the relative positional relation between the mask and the photosensitive substrate, based on the positional information read out from the memory, while the mask and the photosensitive substrate are stopped at the exposure start position and/or during the exposure.

Scanning exposure apparatus and method

An exposure apparatus, having an illumination optical system for radiating a light beam from a light source to a pattern area of a mask for transferring the image of the pattern area onto a photosensitive substrate by the light beam passing through the mask, is provided with plural sets of a first reference mark and a second reference mark arranged on the mask and the photosensitive substrate at positions corresponding to each other, and a light-shielding device for shielding the light beams radiated toward the second reference marks, whereby it is possible to re-use the second reference marks in a post-process by preventing the first reference marks on the mask from being superposed on the second reference marks on the photosensitive substrate or from being transferred onto a part near the second reference marks.

Growing community of inventors

Yokohama, Japan

Seiji Miyazaki