A glass substrate for a high-frequency device, which contains SiO.sub.2 as a main component, the glass substrate having a total content of alkali metal oxides in the range of 0.001-5% in terms of mole percent on the basis of oxides, the alkali metal oxides having a molar ratio represented by Na.sub.2O/(Na.sub.2O+K.sub.2O) in the range of 0.01-0.99, and the glass substrate having a total content of alkaline earth metal oxides in the range of 0.1-13% in terms of mole percent on the basis of oxides, wherein at least one main surface of the glass substrate has a surface roughness of 1.5 nm or less in terms of arithmetic average roughness Ra, and the glass substrate has a dielectric dissipation factor at 35 GHz of 0.007 or less.

A method of manufacture of a coated glazing includes the following steps in sequence a) providing a transparent glass substrate, b) etching a surface of the substrate with an acidic gas, and c) directly or indirectly coating said surface with at least one layer based on a transparent conductive coating (TCC) and/or at least one layer based on a material with a refractive index of at least 1.75.

A glass plate includes a main surface, and a microscopic asperity surface disposed on the main surface, the microscopic asperity surface forming peaks and valleys. When a reference plane is defined as a plane at a center, in a direction of height, of an interval of highest frequency in a histogram of height of shape data of a square region having 2 m per side in the microscopic asperity surface, the number of peaks that are higher than the reference plane by 20% or more of a maximum height difference in the square region is in a range between 1 or more and 300 or less.

A magnetic-disk glass substrate of the present invention includes a pair of main surfaces, a side wall surface, and a chamfered surface between the main surfaces and the side wall surface. Regarding surface properties of at least one of the side wall surface and the chamfered surface of the glass substrate, an arithmetic average roughness (Ra) is 0.015 m or less, and a bearing factor of a roughness cross-sectional area when a roughness percentage is 60% is 95% or more in a bearing curve of a roughness cross-sectional area.

A mirror, a mirror substrate, a method for producing are provided. The mirror substrate is made of a material having a coefficient of mean linear thermal expansion of less than or equal to 1*10.sup.6/K. The mirror substrate includes at least one feature selected from a group consisting of: a ratio of a lateral dimension to a maximum thickness of at least 100, a ratio of the lateral dimension to the maximum thickness of at least 150, a ratio of the lateral dimension to the maximum thickness of at least 200, a ratio of the lateral dimension to the maximum thickness of at least 300, a weight per unit area of 100 kg/m.sup.2 or less, a weight per unit area of 50 kg/m.sup.2 or less, a weight per unit area of 30 kg/m.sup.2 or less, a weight per unit area of 15 kg/m.sup.2 or less, a mirror surface with a roughness (R.sub.a) of at most 3.5 m, and a mirror surface with a roughness (R.sub.a) of less than 1.2 m.

A coated glazing comprising: a transparent glass substrate, wherein a surface of the substrate is directly or indirectly coated with at least one layer based on a transparent conductive coating (TCC) and/or at least one layer based on a material with a refractive index of at least 1.75, and wherein said surface has an arithmetical mean height of the surface value, Sa, of at least 0.4 nm prior to said coating of said surface.

This invention relates to a protective glass for a capacitive touch control system having a dielectric constant of 8.0-9.8 at room temperature and at an operating frequency of 1 kHz; and another protective glass for a capacitive touch control system, comprising a compressive stress layer of a certain depth formed on the surface of the glass through chemical strengthening treatment. High dielectric constant and high strength glass may be provided, which is applicable to protective glass for a capacitive touch control system and may have high light transmittance and create a good user experience of touch control.

An object of the present invention is to provide a matted object capable of achieving both a lower range of glossiness and an antifouling property. A matted object includes a substrate, and a glassy layer provided on the surface of the substrate. The surface of the glassy layer has a 60-glossiness of 20 or less, a skewness Rsk of 0.5 or more, and a maximum height roughness Rz more than 2.5 m and less than 5.7 m, the skewness Rsk and the maximum height roughness Rz being specified in JIS B0601 (2001).

A quartz glass crucible 1 having a cylindrical side wall portion 10a, a bottom portion 10b, and a corner portion 10c includes a transparent layer 11 as an innermost layer made of quartz glass, a semi-molten layer 13 as an outermost layer made of raw material silica powder solidified in a semi-molten state, and a bubble layer 12 made of quartz glass interposed therebetween. An infrared transmissivity of the corner portion 10c in a state where the semi-molten layer 13 is removed is 25 to 51%, the infrared transmissivity of the corner portion 10c in the state where the semi-molten layer 13 is removed is lower than an infrared transmissivity of the side wall portion 10a, and the infrared transmissivity of the side wall portion 10a in the state where the semi-molten layer 13 is removed is lower than an infrared transmissivity of the bottom portion 10b.

A display article is described herein that includes: a substrate comprising a thickness and a primary surface; and the primary surface having defined thereon a diffractive surface region. The diffractive surface region comprises a plurality of structural features that comprises a plurality of different heights in a multimodal distribution. Further, the substrate exhibits a sparkle of less than 4%, as measured by pixel power deviation (PPD.sub.140) at an incident angle of 0? from normal, a distinctness of image (DOI) of less than 80% at an incident angle of 20? from normal, and a transmittance haze of less than 20% from an incident angle of 0? from normal.