Optical glass and optical component

Abstract

Provided in the present invention is an optical glass, comprising the following components in percentage by weight: SiO2: 8-25%; B2O3: 8-25%; BaO: 30-50%; and La2O3: 20-37%, wherein La2O3 / (SiO2+B2O3) is 0.5-2.0. By means of reasonable component design, the optical glass obtained in the present invention has an appropriate thermal expansion coefficient and is suitable for use in high-performance optical instruments.

Description

Optical glass and optical components Technical Field

[0001] The present invention relates to optical glass, in particular to optical glass with suitable thermal expansion coefficient. Background Art

[0002] In recent years, the rapid development of digitalization and high-precision optical instruments has placed higher demands on the lightweighting and miniaturization of optical components used in various optical instruments, including photographic equipment such as digital cameras and camcorders, and projection equipment such as projectors and projection televisions. Optical glass with a refractive index of 1.64 to 1.74 and an Abbe number of 47 to 56 exhibits high refractive index and moderate dispersion. Its application in optical imaging systems can enhance the field of view of lenses and improve image quality. Optical components made of optical glass also need to possess an appropriate thermal expansion coefficient to withstand the impact of temperature fluctuations, as well as chemical stability to meet the requirements of long-term use in external environments.

[0003] Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an optical glass with a suitable thermal expansion coefficient.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] (1) Optical glass, the components of which, expressed in percentage by weight, contain: SiO2: 8-25%; B2O3: 8-25%; BaO: 30-50%; La2O3: 20-37%, wherein the ratio of La2O3 to (SiO2 + B2O3) is 0.5-2.0.

[0007] (2) The optical glass according to (1), wherein the components are expressed in weight percentage and further contain: Al2O3: 0-5%; and / or ZrO2: 0-5%; and / or Li2O: 0-5%; and / or SrO: 0-5%; and / or Y2O3: 0-5%; and / or a clarifier: 0-0.5%, wherein the clarifier is one or more of Sb2O3, SnO2, SnO, and CeO2.

[0008] (3) Optical glass, the composition of which is expressed in weight percentage, containing SiO2, B2O3, BaO and La2O3 as essential components, wherein La2O3 / (SiO2+B2O3) is 0.5 to 2.0, and the refractive index of the optical glass is n d is 1.64~1.74, Abbe number ν d The thermal expansion coefficient is 47 to 56, 100 / 300℃ 80×10 -7 / K~120×10 -7 / K.

[0009] (4) The optical glass according to (3), wherein the components thereof are expressed in weight percentage and contain: SiO2: 8-25%; and / or B2O3: 8-25%; and / or BaO: 30-50%; and / or La2O3: 20-37%; and / or Al2O3: 0-5%; and / or ZrO2: 0-5%; and / or Li2O: 0-5%; and / or SrO: 0-5%; and / or Y2O3: 0-5%; and / or a clarifier: 0-0.5%, wherein the clarifier is one or more of Sb2O3, SnO2, SnO, and CeO2.

[0010] (5) The optical glass according to any one of (1) to (4), wherein the components thereof, expressed in weight percentage, satisfy one or more of the following four conditions:

[0011] 1) BaO / La2O3 is 1.0 to 2.0, preferably BaO / La2O3 is 1.0 to 1.8, more preferably BaO / La2O3 is 1.1 to 1.6;

[0012] 2) La2O3 / (SiO2+B2O3) is 0.6 to 1.5, preferably La2O3 / (SiO2+B2O3) is 0.7 to 1.2;

[0013] 3) B2O3 / (Al2O3+ZrO2) is 1.0 to 9.0, preferably B2O3 / (Al2O3+ZrO2) is 2.0 to 8.0, and more preferably B2O3 / (Al2O3+ZrO2) is 2.4 to 7.6;

[0014] 4) SiO2 / (Al2O3+ZrO2+Li2O+SrO+Y2O3) is 1.0~8.0, preferably SiO2 / (Al2O3+ZrO2+Li2O+SrO+Y2O3) is 1.5~5.0, and more preferably SiO2 / (Al2O3+ZrO2+Li2O+SrO+Y2O3) is 2.1~4.5.

[0015] (6) The optical glass according to any one of (1) to (4), wherein the components are expressed in weight percentage, wherein: SiO2: 10-20%, preferably SiO2: 13-17%; and / or B2O3: 10-21%, preferably B2O3: 12-16%; and / or BaO: 32-45%, preferably BaO: 34-41%; and / or La2O3: 22-35%, preferably La2O3: 24-31%; and / or Al2O3: 0.1-3%, preferably Al2O3 : 0.5-2%; and / or ZrO2: 0.1-3%, preferably ZrO2: 0.5-2%; and / or Li2O: 0-3%, preferably Li2O: 0-1%; and / or SrO: 0-3%, preferably SrO: 0-2%; and / or Y2O3: 0.1-3%, preferably Y2O3: 0.5-2%; and / or clarifier: 0-0.3%, preferably clarifier: 0-0.2%, wherein the clarifier is one or more of Sb2O3, SnO2, SnO, and CeO2.

[0016] (7) The optical glass according to any one of (1) to (4), wherein the components are expressed in weight percentage, wherein the total content of SiO2, B2O3, BaO, and La2O3 is greater than 90%, preferably the total content of SiO2, B2O3, BaO, and La2O3 is greater than 92%, and more preferably the total content of SiO2, B2O3, BaO, and La2O3 is greater than 94%.

[0017] (8) The optical glass according to any one of (1) to (4), wherein the components are expressed in weight percentage and further contain: Gd2O3+Ta2O5+Na2O+K2O+MgO+CaO: 0-5%, preferably Gd2O3+Ta2O5+Na2O+K2O+MgO+CaO: 0-3%, more preferably Gd2O3+Ta2O5+Na2O+K2O+MgO+CaO: 0-1%.

[0018] (9) The refractive index n of the optical glass according to any one of (1) to (4) d 1.64 to 1.74, preferably 1.66 to 1.72; Abbe number ν d It is 47-56, preferably 49-54.

[0019] (10) The thermal expansion coefficient α of the optical glass according to any one of (1) to (4) 100 / 300℃ 80×10 -7 / K~120×10 -7 / K, preferably 90×10 -7 / K~110×10 -7 / K; and / or water resistance stability D WTwo or more types, preferably one type; and / or transition temperature T g 660°C or less, preferably 640°C or less; and / or a density ρ of 4.50 g / cm 3 Below, preferably 4.40 g / cm 3 Below; and / or 80 The diameter is 390nm or less, preferably 380nm or less; and / or the bubble degree is A grade or above, preferably A0 grade or above, more preferably A 00 level; and / or the refractive index temperature coefficient dn / dt is 0×10 -6 / ℃ or less, preferably -0.1×10 -6 / °C or less, more preferably -0.5×10 -6 / °C or less, and / or the anti-crystallization performance is C grade or higher, preferably B grade or higher, more preferably A grade.

[0020] (11) A glass preform made of any one of the optical glasses described in (1) to (10).

[0021] (12) An optical element made of the optical glass described in any one of (1) to (10), or made of the glass preform described in (11).

[0022] (13) An optical instrument comprising the optical glass described in any one of (1) to (10), or the optical element described in (12).

[0023] The beneficial effects of the present invention are: through reasonable component design, the optical glass obtained by the present invention has an appropriate thermal expansion coefficient, which meets the requirements for use in high-performance optical instruments. DETAILED DESCRIPTION

[0024] The following describes in detail embodiments of the optical glass of the present invention. However, the present invention is not limited to the embodiments described below and can be implemented with appropriate modifications within the scope of the present invention. Furthermore, although repeated descriptions may be omitted as appropriate, this does not limit the scope of the invention. In the following description, the optical glass of the present invention may be simply referred to as "glass."

[0025] [Optical glass]

[0026] The following describes the ranges of the various components (ingredients) of the optical glass of the present invention. In the present invention, unless otherwise specified, the content and total content of each component are all expressed in weight percentage (wt%), that is, the content and total content of each component are expressed as the weight percentage of the total amount of the glass material converted into an oxide composition. Here, the "composition converted into oxides" refers to the case where the oxides, complex salts, hydroxides, etc. used as raw materials for the optical glass of the present invention decompose and convert to oxides during melting, with the total amount of the oxide material being taken as 100%.

[0027] Unless otherwise indicated in specific circumstances, the numerical ranges listed in the present invention include upper and lower limits, and "above" and "below" include the endpoint values, as well as all integers and fractions included in the range, without being limited to the specific values ​​listed when defining the range. The term "and / or" herein is inclusive, for example, "A and / or B" means only A, or only B, or both A and B.

[0028] <Essential Components and Optional Components>

[0029] SiO2 is a network-forming component of glass, maintaining glass stability and ensuring a viscosity suitable for molten glass molding. Excessive SiO2 content reduces the glass's refractive index, increases high-temperature viscosity, and impairs melting performance. Low SiO2 content impairs the glass's anti-devitrification properties and makes striations more likely to form. Therefore, the SiO2 content ranges from 8 to 25%, preferably from 10 to 20%, and more preferably from 13 to 17%.

[0030] B2O3 is a network-forming component of glass, maintaining its stability and improving its melting properties. However, excessive B2O3 content can impair the chemical stability of the glass, reduce its viscosity, and increase its molding difficulty. Low B2O3 content can impair vitrification properties and devitrification resistance, reducing production performance. Therefore, the B2O3 content ranges from 8 to 25%, preferably from 10 to 21%, and more preferably from 12 to 16%.

[0031] BaO is an alkaline earth metal oxide. In the present invention, it can reduce the high-temperature viscosity of glass, improve its melting properties, and lower the temperature coefficient of refractive index. However, high BaO content can deteriorate the glass's anti-devitrification properties and chemical stability. Therefore, the BaO content is 30-50%, preferably 32-45%, and more preferably 34-41%.

[0032] In the present invention, La2O3 increases the refractive index, helping to improve the glass's transmittance in the visible light band and lower the glass's temperature coefficient of refractive index. However, excessive La2O3 content can reduce the glass's resistance to devitrification and chemical stability, and increase the cost of raw materials. Therefore, the La2O3 content is 20-37%, preferably 22-35%, and more preferably 24-31%.

[0033] In some embodiments, by controlling the BaO / La2O3 ratio (BaO / La2O3) below 2.0, the glass can have a suitable viscosity and bubbling degree. However, if the BaO / La2O3 ratio is less than 1.0, the temperature coefficient of refractive index and thermal expansion coefficient of the glass may not meet design requirements. Therefore, the BaO / La2O3 ratio is preferably 1.0 to 2.0, more preferably 1.0 to 1.8, and even more preferably 1.1 to 1.6.

[0034] In some embodiments, by controlling the ratio of the La2O3 content to the total content of SiO2 and B2O3 (SiO2 + B2O3), La2O3 / (SiO2 + B2O3), to below 2.0, the anti-devitrification performance and coloration requirements of the glass can be ensured; however, if La2O3 / (SiO2 + B2O3) is less than 0.5, the refractive index, Abbe number, and thermal expansion coefficient of the glass will not meet the requirements. Therefore, La2O3 / (SiO2 + B2O3) is preferably 0.5 to 2.0, more preferably 0.6 to 1.5, and even more preferably 0.7 to 1.2.

[0035] In the present invention, Al2O3 reduces the thermal expansion coefficient of glass and improves its thermal stability. However, excessive Al2O3 content will increase the glass transition temperature and the glass's high-temperature viscosity, making it difficult to eliminate bubbles. Therefore, the Al2O3 content ranges from 0 to 5%, preferably from 0.1 to 3%, and more preferably from 0.5 to 2%.

[0036] ZrO2 can increase the refractive index of glass and adjust dispersion, while also adjusting the temperature coefficient of refractive index and reducing the coefficient of thermal expansion. However, excessive ZrO2 content can increase the melting temperature of the glass, and a content exceeding 5% can easily lead to crystallization. Therefore, the ZrO2 content range is 0-5%, preferably 0.1-3%, and more preferably 0.5-2%.

[0037] In some embodiments, by controlling the ratio of the B2O3 content to the combined content of Al2O3 and ZrO2 (Al2O3+ZrO2), B2O3 / (Al2O3+ZrO2), to below 9.0, the glass can have suitable density and melting properties. However, if B2O3 / (Al2O3+ZrO2) is less than 1.0, the transition temperature and high-temperature viscosity of the glass are high, bubbles are easily formed in the glass, and the stability of the glass is reduced. Therefore, B2O3 / (Al2O3+ZrO2) is preferably 1.0 to 9.0, more preferably 2.0 to 8.0, and even more preferably 2.4 to 7.6.

[0038] Li2O is an alkali metal oxide with a strong fluxing effect, which helps increase the content of other strength-enhancing components in the glass. Li2O can also lower the glass transition temperature. However, excessive Li2O content can lead to glass crystallization, hindering subsequent thermal processing and negatively impacting the glass's chemical stability and thermal expansion coefficient. Therefore, the Li2O content in the present invention is 0-5%, preferably 0-3%, and more preferably 0-1%.

[0039] SrO can adjust the refractive index and Abbe number of glass and improve its melting properties. However, if its content is too high, the anti-devitrification performance of the glass will decrease and the cost of the glass will increase rapidly. Therefore, the SrO content is 0-5%, preferably 0-3%, and more preferably 0-2%.

[0040] In the present invention, Y2O3 is a component that contributes to high refractive index and low dispersion. Its coexistence with La2O3 improves the glass's anti-devitrification properties. However, a high Y2O3 content can reduce the glass's devitrification resistance and increase its cost. Therefore, the Y2O3 content ranges from 0 to 5%, preferably from 0.1 to 3%, and more preferably from 0.5 to 2%.

[0041] In some embodiments, by controlling the ratio of SiO2 content to the total content of Al2O3, ZrO2, Li2O, SrO and Y2O3 Al2O3+ZrO2+Li2O+SrO+Y2O3, SiO2 / (Al2O3+ZrO2+Li2O+SrO+Y2O3), to below 8.0, the glass can have suitable chemical stability and thermal expansion coefficient; however, if SiO2 / (Al2O3+ZrO2+Li2O+SrO+Y2O3) is lower than 1.0, the anti-crystallization performance and bubble degree of the glass will deteriorate, and the glass will be prone to stone formation. Therefore, the preferred SiO2 / (Al2O3+ZrO2+Li2O+SrO+Y2O3) is 1.0~8.0, the more preferred SiO2 / (Al2O3+ZrO2+Li2O+SrO+Y2O3) is 1.5~5.0, and the further preferred SiO2 / (Al2O3+ZrO2+Li2O+SrO+Y2O3) is 2.1~4.5.

[0042] The present invention includes 0-0.5% of one or more of Sb2O3, SnO, SnO2, and CeO2 as fining agents to enhance the clarification of the glass. The preferred clarifier content is 0-0.3%, more preferably 0-0.2%. When the Sb2O3 content exceeds 0.5%, the glass tends to have reduced clarification properties. Furthermore, its strong oxidizing effect promotes corrosion of the platinum or platinum alloy vessel used to melt the glass and deteriorates the forming mold. Therefore, the present invention preferably includes an Sb2O3 content of 0-0.5%, more preferably 0-0.3%, and even more preferably 0-0.2%. SnO and SnO2 can also serve as fining agents, but when their content exceeds 0.5%, the glass tends to become more tinted. Furthermore, when the glass is heated, softened, and then re-molded by molding, Sn can serve as a starting point for crystal nucleation, leading to devitrification. Therefore, the content of SnO2 in the present invention is preferably 0-0.5%, more preferably 0-0.3%, further preferably 0-0.2%, and further preferably no SnO2 is contained; the content of SnO is preferably 0-0.5%, more preferably 0-0.3%, further preferably 0-0.2%, and further preferably no SnO is contained. CeO2 has a similar effect to SnO2, and its content is preferably 0-0.5%, more preferably 0-0.3%, further preferably 0-0.2%, and further preferably no CeO2 is contained.

[0043] In some embodiments of the present invention, in order to make the optical glass meet the requirements of refractive index and Abbe number, have a suitable thermal expansion coefficient and anti-crystallization performance, as well as excellent chemical stability and bubble degree, the total content of SiO2, B2O3, BaO, and La2O3 is preferably above 90%, more preferably above 92%, and further preferably above 94%.

[0044] Without affecting the performance of the glass of the present invention, it may appropriately contain one or more components of Gd2O3, Ta2O5, Na2O, K2O, MgO, and CaO. The content of the above components individually or in total is preferably less than 5%, more preferably less than 3%, further preferably less than 1%, and further preferably does not contain the above components.

[0045] <Components that should not be contained>

[0046] In the glass of the present invention, even if oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained alone or in combination in small amounts, the glass will be colored and absorb specific wavelengths in the visible light region, thereby weakening the property of the present invention of improving visible light transmittance. Therefore, it is preferably substantially free of such oxides, especially in optical glasses requiring transmittance at wavelengths in the visible light region.

[0047] Oxides of Th, Cd, Tl, Os, Be, and Se have been increasingly regulated as hazardous chemicals in recent years, necessitating environmental protection measures not only during glass manufacturing but also during processing and post-product disposal. Therefore, given the importance of environmental impact, it is preferable to virtually eliminate these oxides, except where they are unavoidably incorporated. This results in optical glass being virtually free of environmentally polluting substances. Therefore, even without adopting specific environmental countermeasures, the optical glass of the present invention can be manufactured, processed, and disposed of.

[0048] In order to achieve environmental friendliness, the optical glass of the present invention preferably does not contain As2O3 and PbO.

[0049] The "does not contain" and "0%" recorded herein means that the compound, molecule or element is not intentionally added as a raw material to the optical glass of the present invention; however, as raw materials and / or equipment for producing optical glass, there may be certain impurities or components that are not intentionally added, which may be contained in small amounts or trace amounts in the final optical glass. This situation is also within the scope of protection of the patent of this invention.

[0050] Next, the properties of the optical glass of the present invention will be described.

[0051] <Refractive Index and Abbe Number>

[0052] The refractive index of optical glass (n d ) and Abbe number (ν d ) Tested in accordance with the method specified in GB / T 7962.1-2010.

[0053] In some embodiments, the refractive index (n d ) is 1.64, and the preferred lower limit is 1.66.

[0054] In some embodiments, the refractive index (n d ) is 1.74, and the preferred upper limit is 1.72.

[0055] In some embodiments, the Abbe number (ν d ) is 47, and the preferred lower limit is 49.

[0056] In some embodiments, the Abbe number (ν d ) is 56, and the preferred upper limit is 54.

[0057] <Coefficient of Thermal Expansion>

[0058] Thermal expansion coefficient of optical glass (α 100 / 300℃ ) The data at 100-300℃ were tested according to the method specified in GB / T7962.16-2010.

[0059] In some embodiments, the thermal expansion coefficient (α 100 / 300℃ ) is 80×10 -7 / K~120×10 -7 / K, preferably 90×10 -7 / K~110×10 -7 / K.

[0060] <Water resistance stability>

[0061] Water resistance stability of optical glass (D W ) (Powder method) Tested in accordance with the method specified in GB / T 17129.

[0062] In some embodiments, the water resistance stability (D W ) is 2 or more types, preferably 1 type.

[0063] <Transition Temperature>

[0064] Transition temperature of optical glass (T g) Test according to the method specified in GB / T7962.16-2010.

[0065] In some embodiments, the transition temperature (T g ) is 660°C or lower, preferably 640°C or lower.

[0066] <density>

[0067] Density (ρ) is tested according to the method specified in GB / T7962.20-2010.

[0068] In some embodiments, the density (ρ) of the optical glass of the present invention is 4.50 g / cm 3 Below, preferably 4.40 g / cm 3 the following.

[0069] <Color>

[0070] The short-wave transmission spectrum characteristics of the glass of the present invention are expressed by the coloration (λ 80 ) indicates. 80 Refers to the wavelength when the glass transmittance reaches 80%. 80 The measurement is to use a glass with a thickness of 10±0.1mm and two parallel and optically polished opposite surfaces to measure the spectral transmittance in the wavelength range from 280nm to 700nm and the wavelength at which the transmittance is 80%. The so-called spectral transmittance or transmittance is the wavelength at which the incident intensity I is perpendicular to the above surface of the glass. in Light of intensity I passes through the glass and emerges from a plane out The light of the case through I out / I in The amount expressed by λ also includes the transmittance of the glass due to surface reflection losses on the surface above. The higher the refractive index of the glass, the greater the surface reflection losses. Therefore, in high refractive index glass, λ 80 A small value of means that the glass itself is less colored and the light transmittance is high.

[0071] In some embodiments, the λ of the optical glass of the present invention is 80 390nm or less, preferably λ 80 Below 380nm.

[0072] <Bubble Degree>

[0073] The bubble degree of optical glass is tested according to the method specified in GB / T7962.8-2010.

[0074] In some embodiments, the bubble degree of the optical glass of the present invention is above grade A, preferably above grade A0, and more preferably above grade A. 00 class.

[0075] <Refractive Index Temperature Coefficient>

[0076] The temperature coefficient of refractive index of optical glass (dn / dt) is measured in the range of 20-40℃ according to the method specified in GB / T 7962.4-2010. -6 / ℃))

[0077] In some embodiments, the temperature coefficient of refractive index (dn / dt) of the optical glass of the present invention is 0×10 -6 / ℃ or less, preferably -0.1×10 -6 / °C or less, more preferably -0.5×10 -6 / ℃ below.

[0078] <Anti-crystallization performance>

[0079] The anti-crystallization performance of glass is tested by the following method:

[0080] The glass sample was processed into 20×20×10mm specifications, polished on both sides, and placed in a temperature of T g Keep the glass in a crystallization furnace at +200℃ for 30 minutes, take it out and cool it down, then polish the two large surfaces. Judge the crystallization performance of the glass according to Table 1 below, with grade A being the best and grade E being the worst.

[0081] Table 1. Classification and judgment criteria of anti-crystallization performance

[0082] In some embodiments, the anti-devitrification performance of the optical glass of the present invention is C-level or higher, preferably B-level or higher, and more preferably A-level.

[0083] [Method for manufacturing optical glass]

[0084] The optical glass of the present invention is produced using conventional raw materials and processes, including but not limited to salt raw materials (such as carbonates, nitrates, sulfates, etc.), hydroxides, oxides, boric acid, etc., and after being prepared according to conventional methods, the prepared charge is placed in a melting furnace (such as a platinum crucible, a quartz crucible, etc.) at 1000-1400°C for melting. After clarification, stirring, and homogenization, a homogeneous molten glass free of bubbles and undissolved matter is obtained. The molten glass is then cast in a mold and annealed. Those skilled in the art can appropriately select the raw materials, process methods, and process parameters according to actual needs.

[0085] [Glass preforms and optical components]

[0086] A glass preform can be produced from the produced optical glass using, for example, grinding, or press molding such as re-hot pressing or precision stamping. Specifically, the glass preform can be produced by mechanical processing such as grinding or lapping the optical glass, or by producing a preform for press molding from the optical glass, re-hot pressing the preform, and then grinding the preform, or by precision stamping the preform produced by grinding.

[0087] It should be noted that the means for preparing glass preforms are not limited to the above-mentioned means. As described above, the optical glass of the present invention is useful for various optical elements and optical designs. It is particularly preferred to form a preform from the optical glass of the present invention and use this preform to perform re-hot pressing, precision stamping, etc. to produce optical elements such as lenses and prisms.

[0088] The glass preform and optical element of the present invention are both formed from the optical glass of the present invention. The glass preform and optical element of the present invention possess the excellent properties of optical glass, and they can provide various optical elements such as lenses and prisms with high optical value.

[0089] Examples of the lens include various lenses having spherical or aspherical lens surfaces, such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens, and a plano-concave lens.

[0090] [Optical Instruments]

[0091] The optical elements formed by the optical glass of the present invention can be used to make optical instruments such as photographic equipment, video equipment, display equipment and monitoring equipment.

[0092] Example

[0093] <Optical Glass Example>

[0094] In order to further clearly illustrate and describe the technical solutions of the present invention, the following non-limiting examples are provided.

[0095] This embodiment uses the above-mentioned optical glass manufacturing method to obtain optical glasses having the compositions shown in Tables 2 and 3. In addition, the properties of each glass were measured using the testing method described in the present invention, and the measurement results are shown in Tables 2 and 3.

[0096] Table 2.

[0097] Table 3.

[0098] <Glass Preform Example>

[0099] The glass obtained from optical glass examples 1 to 14# is used to make preforms of various lenses, prisms, etc., such as concave meniscus lenses, convex meniscus lenses, double convex lenses, double concave lenses, plano-convex lenses, and plano-concave lenses, by means of, for example, grinding processing, or molding methods such as re-hot pressing, precision stamping, etc.

[0100] <Optical Element Example>

[0101] The preforms obtained from the above-mentioned glass preform embodiments are annealed to reduce deformation inside the glass and perform fine adjustments so that optical properties such as refractive index reach desired values.

[0102] Each preform is then ground and polished to produce various lenses and prisms, including concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses. The surfaces of the resulting optical elements can also be coated with an anti-reflection film.

[0103] <Optical Instrument Example>

[0104] The optical element obtained from the above-mentioned optical element embodiment is optically designed to form an optical component or optical assembly by using one or more optical elements, and can be used in, for example, imaging equipment, sensors, microscopes, medical technology, digital projection, communications, optical communication technology / information transmission, optics / lighting in the automotive field, photolithography technology, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices including such circuits and chips, or in camera equipment and devices in the automotive field.

Claims

1. An optical glass, characterized in that, Its components are expressed in weight percentages and contain: SiO2: 8 - 25%; B2O3: 8 - 25%; BaO: 30 - 50%; La2O3: 20 - 37%, where La2O3 / (SiO2 + B2O3) is 0.5 - 2.

0.

2. The optical glass according to claim 1, wherein Its components are expressed in weight percentages and also contain: Al2O3: 0 - 5%; and / or ZrO2: 0 - 5%; and / or Li2O: 0 - 5%; and / or SrO: 0 - 5%; and / or Y2O3: 0 - 5%; and / or clarifying agent: 0 - 0.5%, and the clarifying agent is one or more of Sb2O3, SnO2, SnO, CeO2.

3. Optical glass, characterized in that, Its components are expressed in weight percentages and contain SiO2, B2O3, BaO and La2O3 as essential components, where La2O3 / (SiO2 + B2O3) is 0.5 to 2.0, and the refractive index n of the optical glass d is 1.64 to 1.74, and the Abbe number ν d is 47 to 56, and the thermal expansion coefficient α 100 / 300℃ is 80×10 -7 / K to 120×10 -7 / K.

4. The optical glass according to claim 3, characterized in that, Its components are expressed in weight percentages and contain: SiO2: 8 - 25%; and / or B2O3: 8 - 25%; and / or BaO: 30 - 50%; and / or La2O3: 20 - 37%; and / or Al2O3: 0 - 5%; and / or ZrO2: 0 - 5%; and / or Li2O: 0 - 5%; and / or SrO: 0 - 5%; and / or Y2O3: 0 - 5%; and / or clarifying agent: 0 - 0.5%, and the clarifying agent is one or more of Sb2O3, SnO2, SnO, CeO2.

5. The optical glass according to any one of claims 1 to 4, characterized in that, Its components are expressed in weight percentages and satisfy one or more of the following 4 cases: 1) BaO / La2O3 is 1.0 - 2.0, preferably BaO / La2O3 is 1.0 - 1.8, more preferably BaO / La2O3 is 1.1 - 1.6; 2) La2O3 / (SiO2 + B2O3) is 0.6 - 1.5, preferably La2O3 / (SiO2 + B2O3) is 0.7 - 1.2; 3) B2O3 / (Al2O3 + ZrO2) is 1.0 - 9.0, preferably B2O3 / (Al2O3 + ZrO2) is 2.0 - 8.0, more preferably B2O3 / (Al2O3 + ZrO2) is 2.4 - 7.6; 4) SiO2 / (Al2O3 + ZrO2 + Li2O + SrO + Y2O3) is 1.0 - 8.0, preferably SiO2 / (Al2O3 + ZrO2 + Li2O + SrO + Y2O3) is 1.5 - 5.0, more preferably SiO2 / (Al2O3 + ZrO2 + Li2O + SrO + Y2O3) is 2.1 - 4.

5.

6. The optical glass according to any one of claims 1 to 4, characterized in that, The components are expressed in weight percentages, wherein: SiO2: 10 - 20%, preferably SiO2: 13 - 17%; and / or B2O3: 10 - 21%, preferably B2O3: 12 - 16%; and / or BaO: 32 - 45%, preferably BaO: 34 - 41%; and / or La2O3: 22 - 35%, preferably La2O3: 24 - 31%; and / or Al2O3: 0.1 - 3%, preferably Al2O3: 0.5 - 2%; and / or ZrO2: 0.1 - 3%, preferably ZrO2: 0.5 - 2%; and / or Li2O: 0 - 3%, preferably Li2O: 0 - 1%; and / or SrO: 0 - 3%, preferably SrO: 0 - 2%; and / or Y2O3: 0.1 - 3%, preferably Y2O3: 0.5 - 2%; and / or clarifying agent: 0 - 0.3%, preferably clarifying agent: 0 - 0.2%, and the clarifying agent is one or more of Sb2O3, SnO2, SnO, CeO2.

7. The optical glass according to any one of claims 1 to 4, characterized in that, The components are expressed in weight percentages, wherein: the total content of SiO2, B2O3, BaO, and La2O3 is more than 90%, preferably the total content of SiO2, B2O3, BaO, and La2O3 is more than 92%, and more preferably the total content of SiO2, B2O3, BaO, and La2O3 is more than 94%.

8. The optical glass according to any one of claims 1 to 4, characterized in that, The components are expressed in weight percentages and further contain: Gd2O3 + Ta2O5 + Na2O + K2O + MgO + CaO: 0 - 5%, preferably Gd2O3 + Ta2O5 + Na2O + K2O + MgO + CaO: 0 - 3%, and more preferably Gd2O3 + Ta2O5 + Na2O + K2O + MgO + CaO: 0 - 1%.

9. The optical glass according to any one of claims 1 to 4, characterized in that, The refractive index n of the optical glass d is 1.64 to 1.74, preferably 1.66 to 1.72; the Abbe number ν d is 47 to 56, preferably 49 to 54.

10. The optical glass according to any one of claims 1 to 4, characterized in that, The thermal expansion coefficient α of the optical glass 100 / 300℃ is 80×10 -7 / K to 120×10 -7 / K, preferably 90×10 -7 / K to 110×10 -7 / K; and / or the stability D against the action of water W is above Class 2, preferably Class 1; and / or the transformation temperature T g is below 660 °C, preferably below 640 °C; and / or the density ρ is 4.50 g / cm 3 or less, preferably 4.40 g / cm 3 or less; and / or λ 80 is below 390 nm, preferably below 380 nm; and / or the bubble degree is above Grade A, preferably above Grade A0, more preferably Grade A 00 ; and / or the refractive index temperature coefficient dn / dt is 0×10 -6 / °C or less, preferably -0.1×10 -6 / °C or less, more preferably -0.5×10 -6 / °C or less, and / or the anti-crystallization performance is above Grade C, preferably above Grade B, more preferably Grade A.

11. Glass preform, characterized in that, It is made of the optical glass according to any one of claims 1 - 10.

12. Optical element, characterized in that, It is made of the optical glass according to any one of claims 1 - 10, or is made of the glass preform according to claim 11.

13. An optical instrument, characterized in that, It contains the optical glass according to any one of claims 1 - 10, or contains the optical element according to claim 12.

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