Glass production device, glass production method, glass, optical element, optical device, and levitation-melted glass

Abstract

According to the present invention, a glass production device for producing glass via a process that lowers the temperature of a glass starting material includes a support part that has a gas ejection hole in an upper surface and can support the glass starting material in a non-contact manner using a gas ejected from the gas ejection hole, a heating part that heats the glass starting material on the support part, and a gas supply part that supplies the gas to the gas ejection hole. The gas supply part includes an intake part that takes in the gas from the outside and a reduction part that reduces the number of particles in the gas taken in by the intake part.

Description

Glass manufacturing apparatus, glass manufacturing method, glass, optical element, optical device, and floating molten glass

[0001] The present invention relates to a glass manufacturing apparatus, a glass manufacturing method, glass, an optical element, an optical device, and a floating molten glass.

[0002] For example, Patent Document 1 discloses a method for manufacturing optical glass using a laser levitation furnace.

[0003] Japanese Patent Application Laid-Open No. 2021-046354

[0004] An aspect of the present invention is, for example, a glass manufacturing apparatus for manufacturing glass through a step of lowering the temperature of glass raw materials, the apparatus comprising: a support part having gas ejection holes on an upper surface and capable of supporting the glass raw materials in a non-contact manner by gas ejected from the gas ejection holes; a heating part heating the glass raw materials on the support part; and a gas supply part supplying gas to the gas ejection holes, the gas supply part comprising an intake part taking in the gas from the outside, and a reduction part reducing the number of particles in the gas taken in by the intake part.

[0005] Another aspect of the present invention is a glass manufacturing apparatus for manufacturing glass through a step of lowering the temperature of glass raw materials, the apparatus comprising: a support part having gas ejection holes on an upper surface and capable of supporting the glass raw materials in a non-contact manner by gas ejected from the gas ejection holes; a heating part for heating the glass raw materials on the support part; and a gas supply part for supplying gas to the gas ejection holes so that the total content of Cr, Mn, Fe, Co, Ni and Cu in the glass is 5 ppm or less in terms of mass.

[0006] Another aspect of the present invention is a method for producing glass, comprising: a mixing step of mixing raw materials for the glass to obtain a raw material mixture; a non-contact supporting step of supporting the raw material mixture in a non-contact manner; a heating step of heating the raw material mixture to form a molten liquid; and a cooling step of cooling the raw material mixture in the molten liquid state to obtain glass, wherein the raw materials are mixed in the mixing step using a tool that is substantially free of Cr, Mn, Fe, Co, Ni, and Cu in parts that come into contact with the raw materials.

[0007] Another aspect of the present invention is a glass having an Abbe number (νｄ ) is 30≦ν ｄ ≦60, partial dispersion ratio (P ｇ,Ｆ ) is (formula) P ｇ,Ｆ ≦−0.0020×ν ｄ +0.6535, the wavelength at which the transmittance at a thickness of 10 mm is 80% or less (λ ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ Meets +475.

[0008] Another aspect of the present invention is a glass having an Abbe number (ν ｄ ) is 15≦νd≦30, and the partial dispersion ratio (P ｇ,Ｆ ) is (formula) P ｇ,Ｆ ≦−0.0047×ν ｄ +0.7345, the wavelength at which the transmittance at a thickness of 10 mm is 80% or less (λ ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ Meets +475.

[0009] Another aspect of the present invention is a glass comprising, in mole percent, B ２ O ３ , SiO ２ , P ２ O ５ and As ２ O ３ The total content of (B ２ O ３ +SiO ２ +P ２ O ５ +As ２ O ３ ): 40% or less, Li ２ O.K. ２ O, Na ２ O, P ２ O ５ and B ２ O ３ The total content of (Li ２ O+K ２ O + Na ２ O+P ２ O ５ +B ２ O ３ ): 5% or less, La ２ O ３ , BaO, CaO, MgO, Y ２ O ３ , Gd２ O ３ , Al ２ O ３ , TiO ２ , Nb ２ O ５ , ZrO ２ and Ta ２ O ５ Total content (La ２ O ３ +BaO+CaO+MgO+Y ２ O ３ +Gd ２ O ３ +Al ２ O ３ + TiO ２ +Nb ２ O ５ + ZrO ２ +Ta ２ O ５ ): 60% or more, and the total content of Cr, Mn, Fe, Co, Ni and Cu: 5 ppm or less, calculated by mass.

[0010] Another aspect of the present invention is a glass comprising, in mole percent, B ２ O ３ , SiO ２ , P ２ O ５ and As ２ O ３ The total content of (B ２ O ３ +SiO ２ +P ２ O ５ +As ２ O ３ ): 40% or less, Li ２ O.K. ２ O, Na ２ O, P ２ O ５ and B ２ O ３ The total content of (Li ２ O+K ２ O + Na ２ O+P ２ O ５ +B ２ O ３ ): 5% or less, La ２ O ３ , BaO, CaO, MgO, Y ２ O３ , Gd ２ O ３ , Al ２ O ３ , TiO ２ , Nb ２ O ５ , ZrO ２ and Ta ２ O ５ Total content (La ２ O ３ +BaO+CaO+MgO+Y ２ O ３ +Gd ２ O ３ +Al ２ O ３ + TiO ２ +Nb ２ O ５ + ZrO ２ +Ta ２ O ５ ): 60% or more, and the wavelength (λ) at which the transmittance at a thickness of 10 mm is 80% or less ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ Meets +475.

[0011] Another aspect of the present invention is an optical glass using the above glass.

[0012] Another aspect of the present invention is an optical element using the above optical glass.

[0013] Another aspect of the present invention is an optical device using the above optical element.

[0014] Another aspect of the present invention is a floating glass, which has a wavelength (λ ) at which the transmittance at a thickness of 10 mm is 80% or less. ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ Meets +475.

[0015] Another aspect of the present invention is a glass manufacturing apparatus for manufacturing glass through a step of lowering the temperature of a glass raw material, the apparatus comprising: a support part having gas ejection holes on an upper surface and capable of supporting the glass raw material in a non-contact manner by gas ejected from the gas ejection holes; a heating part heating the glass raw material on the support part; and a gas supply part supplying gas having a particle count of 1000 or less per 100 L to the gas ejection holes.

[0016] Another aspect of the present invention is a glass manufacturing method for manufacturing glass via a step of lowering the temperature of a glass frit, comprising a non-contact supporting step of supporting the glass frit in a molten state in a non-contact manner using a gas having a particle number of 1000 or less per 100 L.

[0017] Another aspect of the present invention is a method for producing glass via a step of lowering the temperature of glass frits, comprising a non-contact supporting step of supporting the glass frits in a molten state in a non-contact manner using a gas such that the total content of Cr, Mn, Fe, Co, Ni and Cu in the glass is 5 ppm or less in terms of mass.

[0018] FIG. 1 is a schematic diagram of a manufacturing apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a manufacturing apparatus according to a second embodiment of the present invention. FIG. 3 is a perspective view of an example in which the optical device according to each embodiment is used as an imaging device. FIG. 4 is a front view of another example in which the optical device according to each embodiment is used as an imaging device. FIG. 5 is a rear view of another example in which the optical device according to each embodiment is used as an imaging device. FIG. 6 is a block diagram of an example in which the optical device according to each embodiment is used as a multiphoton microscope. FIG. 7 is a schematic diagram of an example of a cemented lens according to each embodiment. FIG. 8 is a graph of the internal transmittance (%) of Example 5 and Comparative Example 4. FIG. 9 is a graph of the internal transmittance (%) of Example 6 and Comparative Example 5. FIG. 10 is a graph of the internal transmittance (%) of Example 7 and Comparative Example 6. FIG. 11 is a graph showing the internal transmittance (%) of Example 8 and Comparative Example 7. FIG. 12 is a graph showing the internal transmittance (%) of Example 9 and Comparative Example 8. ｇ.F and ν ｄ λ of Examples 12 to 16 ８０ value (unit: nm) and ν ｄ This is a graph plotting

[0019] An embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described below. The present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content.

[0020] In the drawings, the same elements are denoted by the same reference numerals, and redundant explanations will be omitted. Furthermore, unless otherwise specified, the positional relationships, such as up, down, left, and right, are based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

[0021] <Outline of Manufacturing Apparatus 10: First Embodiment>

[0022] FIG. 1 is a schematic diagram of a manufacturing apparatus 10 according to a first embodiment of the present invention. As shown in FIG. 1, the manufacturing apparatus 10 is a glass manufacturing apparatus. The manufacturing apparatus 10 manufactures glass by levitating a sample U containing glass raw materials using a gas, and at some point, heating and melting the sample U to lower the temperature of the sample U. Note that levitating the sample U is also referred to as supporting the sample U in a non-contact manner. The glass raw materials are a press-molded body, a sintered body of a press-molded body, or an aggregate of crystals.

[0023] The manufacturing apparatus 10 includes a stage 11, a support member 12 that supports the glass frit in a non-contact manner, a laser light source 13 that irradiates the levitated glass frit with laser light L, mirrors 14 and 15 that guide the laser light L to the glass frit, a radiation thermometer 16 that measures the temperature of the levitated sample U, a computer 17 that has a control unit (not shown) that controls the output of the laser light source 13 based on temperature information from the radiation thermometer 16, a CCD camera 18, a monitor 19, and a gas supply unit 20 that supplies gas to the sample U indicated by the support member 12.

[0024] The support member 12 has gas ejection holes on its upper surface W, and supports the sample U in a non-contact manner by gas ejected from the gas ejection holes. For example, the manufacturing apparatus 10 heats the sample U floating above the support member 12 arranged on the stage 11 in a non-contact manner by irradiating it with laser light L. In other words, the laser light source 13 that irradiates the laser light L and the mirrors 14 and 15 that direct the laser light L to the sample U function as a heating unit. As a result, the sample U melts and becomes a molten liquid having a substantially spherical or ellipsoidal shape due to its own surface tension, and floats in that state.

[0025] The temperature of the sample U heated by the irradiation of the laser light L is monitored by a radiation thermometer 16. Based on the temperature information of the sample U monitored by the radiation thermometer 16, the output of the laser light source 13 is controlled by a computer 17. The state of the sample U is also imaged by a CCD camera 18, and the image is output to a monitor 19. The configuration of the laser light source 13 is not particularly limited, and examples include a carbon dioxide laser, a semiconductor laser, a fiber laser, and a YAG laser. The heating unit may be configured to heat the sample U non-contact, and a heat source other than the laser light source 13 may be used, or the laser light source 13 may be used in combination with another heat source. For example, after non-contact heating of the stably levitated sample U, the laser light L is shut off. This causes the melt (sample U) to cool and solidify, resulting in glass. The glass obtained in this manner is called a float melt glass. The glass obtained in this embodiment is, for example, optical glass.

[0026] In this embodiment, the gas supply unit 20 that supplies gas to the gas ejection holes of the support member 12 has an intake unit 21 that takes in gas from the outside and a reduction unit 22 that reduces the number of particles, which are impurities, in the gas taken in by the intake unit 21. The intake unit 21 has a pipe 23 through which the gas passes and a connection unit 25 that connects the pipe 23 to another external pipe t. The gas supply unit 20 may further have a flow rate adjustment unit 24 that can change the flow rate of the gas.

[0027] The intake section 21 is a section for taking in gas from the outside. Any known type of gas can be appropriately adopted depending on the purpose. Specific examples include oxygen, carbon dioxide, nitrogen, argon, and air. Depending on the gas used, the intake section 21 is connected to, for example, a pipe for taking in outside air provided in the building in which the manufacturing apparatus 10 is installed, a pipe connected to a gas-filled cylinder (gas cylinder), or a pipe connected to a device that takes in gas from the atmosphere, such as a compressor.

[0028] The connection part 25 is a member that connects the pipe 23 to the pipe (external pipe) t through which the introduced gas passes. For example, the ends of the pipe 23 and the pipe t are tightly attached via a gasket or ferrule, and a nut attached to one pipe is rotated and slid against a male thread attached around the other pipe to fasten them, thereby forming a joint that connects the pipes so as to prevent gas leakage.

[0029] When the gas supply unit 20 has a flow rate adjustment unit 24, the gas taken in through the pipe t passes through the connection unit 25 and the pipe 23 and is taken in by the flow rate adjustment unit 24. When the pipe t is connected to the flow rate adjustment unit 24 without a joint, the inlet of the flow rate adjustment unit 24 can be said to function as the connection unit 25. A cock for opening and closing the gas flow path may be provided midway along the pipe 23.

[0030] The flow rate adjustment unit 24 is a device that measures the flow rate of the gas and adjusts the flow rate of the gas. The flow rate adjustment unit 24 is, for example, a mass flow meter for gas. Note that the gas flow rate may be controlled by the computer 17, and the flow rate adjustment unit 24 may measure the gas flow rate.

[0031] The reduction unit 22 reduces the number of particles in the gas so that the number of particles per 100 L of gas is 1,000 or less. For example, the number of particles with a diameter of 0.3 μm or more per 100 L of gas may be 1,000 or less. The reduction unit 22 is a porous member such as an air filter. When the reduction unit 22 is an air filter, the air filter preferably has a filtration diameter of 10 μm or less. More specifically, the reduction unit 22 reduces the number of particles in the gas so that the total content of Cr, Mn, Fe, Co, Ni, and Cu in the glass is 5 ppm or less by mass.

[0032] The reduction unit 22 may use any method as long as it can reduce the number of particles. For example, the reduction unit 22 may reduce the number of particles by passing a gas through a predetermined liquid to dissolve the particles. Alternatively, for example, the reduction unit 22 may reduce the number of particles by centrifuging the gas. Alternatively, the reduction unit 22 may reduce the number of particles by generating static electricity in the gas flow path, thereby attracting particles to the locations where static electricity is generated, or by attracting particles using magnetic force.

[0033] Depending on the configuration of the flow rate adjuster 24, particles may be generated from the flow rate adjuster 24. As an example, the reduction unit 22 is disposed between the flow rate adjuster 24 and the gas outlet holes provided on the upper surface W of the support member 12. That is, the reduction unit 22 reduces the number of particles in the gas that has passed through the intake unit 21 and the flow rate adjuster 24. With this configuration, the reduction unit 22 can reduce the number of particles in the gas generated from the flow rate adjuster 24. In another example, the reduction unit 22 may be disposed closer to the pipe t than the flow rate adjuster 24.

[0034] Particles are particles contained in the gas. In addition to particles originating from external gases, particles can also originate from parts where metals slide against each other during assembly or operation of the device (e.g., connectors, cocks, flow rate adjusters), or from equipment such as the pump and pipe t that sends gas into the pipe t. If particles get mixed into the sample U, they can cause foreign matter in the sample U, for example. Furthermore, if the particles contain transition elements, they can cause a deterioration in the performance of the sample U, such as the transmittance. In this embodiment, by providing the reduction section 22, at least a portion of the particles in the gas used to suspend the sample U are removed, reducing the number of particles and contributing to improving the performance of the glass.

[0035] The support member 12 also has gas ejection holes, which may be, for example, a metal with multiple holes drilled therein or a porous material. In this embodiment, the provision of the reduction section 22 can prevent particles from reaching and clogging the gas ejection holes. This prevents deterioration of the support member 12 and allows the same support member 12 to be used for a long period of time.

[0036] The pipe 23 is not limited to being a single pipe, and may be configured to branch the gas flow path along the way or to join multiple flow paths along the way. A configuration may be provided in which multiple connection sections, flow rate adjustment sections, and reduction sections are provided, and these are connected by the pipe 23. Depending on the configuration, particles may be generated at the branching or joining points of the gas flow paths. The reduction section 22 may be disposed between the branching or joining points of the gas flow paths and the gas ejection holes. With such a configuration, the number of particles in the gas generated from the branching or joining points of the gas flow paths can be reduced.

[0037] <Outline of Manufacturing Apparatus 10: Second Embodiment>

[0038] Fig. 2 is a schematic diagram of a manufacturing apparatus 10 according to a second embodiment of the present invention. Differences from the first embodiment will be described below. In this embodiment, glass raw materials are mixed using equipment that does not substantially contain transition elements. As an example, in the second embodiment, glass is manufactured using a manufacturing apparatus 10 as shown in the schematic diagram of Fig. 2. The manufacturing apparatus 10 shown in Fig. 2 does not have a reduction section 22 or a connection section 25.

[0039] The manufacturing apparatus 10 manufactures glass through a process in which a sample U containing glass raw materials is levitated by a gas, and at some point in time, the sample U is heated and melted to reduce the temperature of the sample U. Note that levitating the sample U is also referred to as supporting the sample U in a non-contact manner.

[0040] The glass raw material is a press-molded body, a sintered body of a press-molded body, or an aggregate of crystals. Before placing the sample U on the support member 12, the glass raw materials constituting the sample U are mixed.

[0041] In this mixing process, an apparatus is used that is substantially free of transition elements such as Cr, Mn, Fe, Co, Ni, and Cu in the area where the glass raw materials come into contact. "Substantially free" means that the content of these components is at or below the impurity level. "At or below the impurity level" means, for example, less than 0.01%. This prevents unintended impurities from being mixed into the glass. For example, preventing the mixing of transition elements can prevent a decrease in the transmittance of the glass, thereby obtaining glass with good transmittance.

[0042] The volume of the device is preferably 100 mL or more. Such a configuration increases the volume of glass raw materials that can be processed at one time, thereby improving glass productivity. Furthermore, when producing multiple glasses at once, mixing the raw materials in a device with a larger volume, such as 100 mL or more, at once can reduce variations in physical properties resulting from differences in composition among the multiple glasses, rather than mixing the raw materials in multiple batches using devices with smaller volumes.

[0043] An example of the mixing step may be a step of mixing weighed glass raw materials using a mixing device such as a mortar, a rotary vessel type mixer, a shaker, etc. In this case, such a mixing device should be one that is substantially free of transition elements such as Cr, Mn, Fe, Co, Ni and Cu in the parts that come into contact with the glass raw materials.

[0044] Another example of the mixing step is to mix weighed glass raw materials with a liquid dispersion medium to form a slurry, and mix the resulting slurry using a mixing device for slurry such as a ball mill, a bead mill, a stirrer, a shaker, etc. Thereafter, a step of drying the mixed slurry to obtain a cake and pulverizing and mixing the cake using a mixing device for cake such as a mortar, a jaw crusher, a stone mill, a jet mill, a mixer, etc. In this case, the mixing device for slurry and the mixing device for cake are those that are substantially free of transition elements such as Cr, Mn, Fe, Co, Ni, and Cu in the parts that come into contact with the glass raw materials.

[0045] In addition, for example, stainless steel is often used for mixing equipment because of its excellent corrosion resistance, strength, and workability, but it is an alloy of transition elements such as Fe, Cr, and Ni. Therefore, in this embodiment, the use of stainless steel is avoided, or the part that comes into contact with the raw materials is covered or coated with a substance that does not substantially contain transition elements such as Cr, Mn, Fe, Co, Ni, and Cu, so that the part that comes into contact with the glass raw materials does not substantially contain transition elements such as Cr, Mn, Fe, Co, Ni, and Cu.

[0046] In a device that is substantially free of transition elements such as Cr, Mn, Fe, Co, Ni, and Cu in the part that comes into contact with the glass raw material, the main material of the part that comes into contact with the glass raw material is not particularly limited, but examples include resin, alumina, quartz, zirconia, silicon nitride, tungsten carbide, silicon carbide, gold, platinum, etc. If a resin with an ignition point of 1000°C or less is used, the resin that comes from the device and is mixed into the glass material will volatilize when the glass is melted.

[0047] The glass raw materials mixed in this manner are formed into a press-molded body, a sintered body of the press-molded body, or an aggregate of crystals, which is supported in a non-contact manner in manufacturing apparatus 10, heated and melted, and then cooled to obtain glass. In this case, manufacturing apparatus 10 may also have reduction section 22.

[0048] In the second embodiment, it is only necessary to use an apparatus that does not substantially contain transition elements in the portion that comes into contact with the glass raw materials in the mixing step. Therefore, also in the second embodiment, it is possible to use a manufacturing apparatus 10 having a reduction section 22 and a connection section 25 as shown in FIG.

[0049] <Glass Composition and Physical Properties> The first and second embodiments (hereinafter referred to as "present embodiments") can be applied to the production of glass of a desired composition, but there are compositions that can be more suitably produced by the present embodiments. For example, the glass produced by the present embodiments contains, in mol %, B ２ O ３ , SiO ２ , P ２ O ５ and As ２ O ３ The total content of (B ２ O ３ +SiO ２ +P ２ O ５ +As ２ O ３ ): is preferably 40% or less, more preferably 25% or less, more preferably 15% or less, and even more preferably 5% or less. These components are highly volatile during melting, and if they are contained in large amounts, the internal homogeneity of the glass tends to decrease and the refractive index variation tends to increase in the float melting process where the specific surface area of ​​the melt is large. Therefore, by setting the composition within this range, it is possible to obtain glass with better internal homogeneity and refractive index variation.

[0050] In addition, the glass manufactured by this embodiment has a wavelength (λ ) at which the transmittance at a thickness of 10 mm is 80% or less. ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ It is preferable to satisfy +475.

[0051] The glass produced according to the present embodiment contains, in mol %, Li ２ O.K. ２ O, Na ２ O, P ２ O ５ and B ２ O ３ The total content of (Li ２ O+K ２ O + Na ２ O+P ２ O ５ +B ２ O ３ ): preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less. These components are highly volatile during melting, and if they are contained in large amounts, the internal homogeneity of the glass tends to decrease and the refractive index variation tends to increase in the float melting process where the specific surface area of ​​the melt is large. Therefore, by setting the composition within this range, it is possible to obtain glass with better internal homogeneity and refractive index variation.

[0052] The glass produced according to the present embodiment contains, in mol %, La ２ O ３ , BaO, CaO, MgO, Y ２ O ３ , Gd ２ O ３ , Al ２ O ３ , TiO ２ , Nb ２ O ５ , ZrO ２ and Ta ２ O ５ Total content (La ２ O ３ +BaO+CaO+MgO+Y ２ O ３ +Gd ２ O ３ +Al ２ O ３ + TiO ２ +Nb ２ O ５ + ZrO ２ +Ta ２ O ５): is preferably 60% or more, more preferably 70% or more, more preferably 75% or more, and even more preferably 80% or more. When the glass raw material is melted in contact with a container such as a crucible, such a composition tends to cause problems such as crystallization, making production difficult. In this embodiment, in which the raw material mass is suspended and melted in a non-contact state, vitrification is easier than when a container such as a crucible is used, and this composition can significantly improve productivity.

[0053] Furthermore, the glass produced by the present embodiment has a total content of Cr, Mn, Fe, Co, Ni, and Cu, calculated by mass, of preferably 5 ppm (mg / kg) or less, more preferably 3 ppm (mg / kg) or less, and even more preferably 1 ppm (mg / kg) or less.

[0054] Furthermore, the glass produced according to this embodiment has an Abbe number (ν ｄ ) is 30≦ν ｄ If the partial dispersion ratio (P ｇ,Ｆ ) is (formula) P ｇ,Ｆ ≦−0.0020×ν ｄ +0.6535, and as mentioned above, the wavelength (λ ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ It is preferable to satisfy +475.

[0055] Furthermore, the glass produced according to this embodiment has an Abbe number (ν ｄ ) is 15≦ν ｄ If the partial dispersion ratio (P ｇ,Ｆ ) is (formula) P ｇ,Ｆ ≦−0.0047×ν ｄ +0.7345, and as mentioned above, the wavelength (λ ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ It is preferable to satisfy +475.

[0056] Glass with these physical properties tends to have a lower partial dispersion ratio relative to the Abbe number and better transmittance than ordinary glass, which contributes to, for example, the miniaturization of optical systems, aberration correction, and the high transmittance of the entire optical system.

[0057] <Optical Elements, Optical Systems, Interchangeable Camera Lenses, Optical Devices, etc.> The optical glass obtained by the manufacturing apparatus 10 according to each embodiment can be suitably used, for example, as an optical element included in an optical instrument. Such optical elements include mirrors, lenses, prisms, filters, etc., and can be widely used as optical systems. The optical systems according to the present embodiments can be suitably used as interchangeable camera lenses including the optical glass. Known configurations can be used for such optical elements, optical lenses, and interchangeable camera lenses. Furthermore, the optical systems according to the present embodiments can be suitably used as optical devices including the optical systems. Optical devices including such optical systems include, but are not limited to, imaging devices such as interchangeable lens cameras and non-interchangeable lens cameras, optical microscopes, and the like. Examples of these devices are described below.

[0058] (Imaging Device) FIG. 3 is a perspective view of an example in which the optical device according to each embodiment is used as an imaging device.

[0059] The imaging device 1 is a so-called digital single-lens reflex camera (interchangeable lens camera), and the photographing lens (optical system) 103 is equipped with the cured product according to this embodiment. A lens barrel 102 is detachably attached to a lens mount (not shown) of a camera body 101. Light passing through a lens 103 of the lens barrel 102 forms an image on a sensor chip (solid-state image sensor) 104 of a multi-chip module 106 arranged on the rear side of the camera body 101. This sensor chip 104 is a bare chip such as a so-called CMOS image sensor, and the multi-chip module 106 is, for example, a COG (chip-on-glass) type module in which the sensor chip 104 is bare-chip mounted on a glass substrate 105.

[0060] FIG. 4 is a front view of another example in which the optical device according to each embodiment is used as an imaging device, and FIG. 5 is a rear view of the imaging device.

[0061] The imaging device CAM is a so-called digital still camera (non-interchangeable lens camera), and the photographing lens (optical system) WL is equipped with the cured product according to this embodiment. When the power button (not shown) of the imaging device CAM is pressed, a shutter (not shown) of the photographing lens WL is opened, and light from a subject (object) is collected by the photographing lens WL and focused on an imaging element disposed on the image plane. The subject image focused on the imaging element is displayed on an LCD monitor M disposed behind the imaging device CAM. After determining the composition of the subject image while looking at the LCD monitor M, the photographer presses the release button B1 to capture the subject image with the imaging element and record and save it in memory (not shown). The imaging device CAM is equipped with an auxiliary light emitter EF that emits auxiliary light when the subject is dark, a function button B2 used to set various conditions for the imaging device CAM, and the like.

[0062] Optical systems used in such digital cameras and the like require higher transmittance. To achieve this, it is necessary to use glass with higher transmittance as optical elements. From this perspective, the optical glass according to each embodiment is suitable as a component of such optical equipment. Note that optical equipment to which each embodiment can be applied is not limited to the imaging device described above, but also includes, for example, projectors. The optical elements are also not limited to lenses, but include, for example, prisms.

[0063] (Multiphoton Microscope) FIG. 6 is a block diagram showing an example in which the optical device according to each embodiment is a multiphoton microscope.

[0064] The multiphoton microscope 2 includes, as optical elements, an objective lens 206, a condenser lens 208, and an imaging lens 210. The following description will focus on the optical system of the multiphoton microscope 2.

[0065] The pulsed laser device 201 emits ultrashort pulsed light, for example, with a near-infrared wavelength (approximately 1000 nm) and a pulse width in femtosecond units (e.g., 100 femtoseconds). The ultrashort pulsed light immediately after being emitted from the pulsed laser device 201 is generally linearly polarized in a predetermined direction.

[0066] The pulse splitting device 202 splits the ultrashort pulsed light, increases the repetition frequency of the ultrashort pulsed light, and emits it.

[0067] The beam adjusting unit 203 has functions such as a function to adjust the beam diameter of the ultrashort pulsed light incident from the pulse splitting device 202 to match the pupil diameter of the objective lens 206, a function to adjust the focusing and divergence angles of the ultrashort pulsed light in order to correct on-axis chromatic aberration (focus difference) between the wavelength of the multiphoton excitation light emitted from the sample S and the wavelength of the ultrashort pulsed light, and a pre-chirp function (group velocity dispersion compensation function) to impart reverse group velocity dispersion to the ultrashort pulsed light in order to correct the pulse width of the ultrashort pulsed light being broadened by group velocity dispersion while passing through the optical system.

[0068] The repetition frequency of the ultrashort pulsed light emitted from the pulsed laser device 201 is increased by the pulse dividing device 202, and the above-mentioned adjustment is performed by the beam adjusting unit 203. The ultrashort pulsed light emitted from the beam adjusting unit 203 is then reflected by the dichroic mirror 204 toward the dichroic mirror 205, passes through the dichroic mirror 205, and is collected by the objective lens 206 to be irradiated onto the sample S. At this time, the ultrashort pulsed light may be scanned over the observation surface of the sample S by using a scanning means (not shown).

[0069] For example, when observing the fluorescence of a sample S, the fluorescent dye with which the sample S is stained undergoes multiphoton excitation in the area of ​​the sample S irradiated with the ultrashort pulsed light and in its vicinity, emitting fluorescence (hereinafter referred to as "observation light") having a wavelength shorter than that of the ultrashort pulsed light, which is an infrared wavelength.

[0070] Observation light emitted from the sample S in the direction of the objective lens 206 is collimated by the objective lens 206 and is reflected by or transmitted through the dichroic mirror 205 depending on its wavelength.

[0071] The observation light reflected by the dichroic mirror 205 enters the fluorescence detection unit 207. The fluorescence detection unit 207 is composed of, for example, a barrier filter, a PMT (photomultiplier tube), etc., receives the observation light reflected by the dichroic mirror 205, and outputs an electrical signal corresponding to the amount of light. Furthermore, the fluorescence detection unit 207 detects the observation light across the observation surface of the sample S as the ultrashort pulsed light scans the observation surface of the sample S.

[0072] On the other hand, the observation light that has passed through the dichroic mirror 205 is descanned by a scanning means (not shown), passes through the dichroic mirror 204, is focused by the focusing lens 208, passes through a pinhole 209 located at a position approximately conjugate to the focal position of the objective lens 206, passes through an imaging lens 210, and enters the fluorescence detection unit 211.

[0073] The fluorescence detection unit 211 is configured with, for example, a barrier filter, a PMT, etc., receives the observation light imaged on the light receiving surface of the fluorescence detection unit 211 by the imaging lens 210, and outputs an electrical signal according to the amount of light. Furthermore, the fluorescence detection unit 211 detects the observation light across the observation surface of the sample S as the ultrashort pulsed light scans the observation surface of the sample S.

[0074] It is also possible to remove the dichroic mirror 205 from the optical path so that all of the observation light emitted from the sample S in the direction of the objective lens 206 is detected by the fluorescence detection unit 211 .

[0075] Furthermore, observation light emitted from the sample S in the direction opposite to the objective lens 206 is reflected by the dichroic mirror 212 and enters the fluorescence detection unit 213. The fluorescence detection unit 213 is composed of, for example, a barrier filter, a PMT, etc., and receives the observation light reflected by the dichroic mirror 212 and outputs an electrical signal according to the amount of light. Furthermore, the fluorescence detection unit 213 detects the observation light across the observation surface of the sample S as the ultrashort pulsed light scans the observation surface of the sample S.

[0076] The electrical signals output from the fluorescence detection units 207, 211, and 213 are input, for example, to a computer (not shown), which can generate an observation image based on the input electrical signals, display the generated observation image, and store the data of the observation image.

[0077] <Cemented Lens> Fig. 7 is a schematic diagram showing an example of a cemented lens according to each embodiment. The cemented lens 3 is a compound lens having a first lens element 301 and a second lens element 302. At least one of the first lens element and the second lens element uses the optical glass according to each embodiment. The first lens element and the second lens element are cemented together via a cementing member 303. A known adhesive or the like can be used as the cementing member 303. Note that the lenses that make up the cemented lens may be referred to as "lens elements" as described above, in order to clearly indicate that they are elements of the cemented lens.

[0078] The cemented lens according to each embodiment is useful from the viewpoint of chromatic aberration correction, and can be suitably used in the optical elements, optical systems, optical devices, etc. described above. Furthermore, optical systems including cemented lenses can be particularly suitably used in interchangeable lenses for cameras, optical devices, etc. While the cemented lens using two lens elements has been described in the above-described embodiments, this is not limiting, and a cemented lens using three or more lens elements may also be used. When a cemented lens using three or more lens elements is used, it is sufficient that at least one of the three or more lens elements is formed using the optical glass according to this embodiment.

[0079] Examples Next, each example will be described, but the present invention is not limited to the following examples in any way.

[0080] <Example 1, Example 2, Comparative Example 1, Comparative Example 2: Particle Reduction Effect of Reduction Unit>

[0081] Example 1 In this example, the number of particles in gas was measured. First, gas (factory air) was taken into the intake section 21 from the building's piping via pipe t. Gas was sent from a mass flow meter functioning as a flow rate adjuster 24 to the support member 12 via the reduction section 22, and the number of particles in the gas ejected from the ejection holes of the support member 12 was measured. An air filter with a filtration diameter of 0.01 μm (Clean Air Filter SFD100-C06, manufactured by SMC Corporation) was used as the reduction section 22. An air particle sensor (Air Particle Sensor ZN-PD-S, manufactured by Omron Corporation) was used for the measurement. The number of particles (particle count) was measured for each particle diameter range.

[0082] Example 2 First, a gas cylinder of pure air (cylinder air: Grade 1) was connected to the pipe t, and gas was taken in through the intake section 21. Thereafter, similarly to Example 1, the gas was sent to the support member 12 through the reduction section 22, and the number of particles in the gas ejected from the ejection holes of the support member 12 was measured.

[0083] Comparative Example 1 As in Example 1, gas (factory air) was taken in from the piping of a building via pipe t into intake section 21. Thereafter, the gas was sent from a mass flow meter functioning as flow rate adjustment section 24 to support member 12 without passing through reduction section 22, and as in Example 1, the number of particles in the gas ejected from the ejection holes of support member 12 was measured.

[0084] Comparative Example 2 As in Example 2, a gas cylinder of pure air was connected to the pipe t, and gas (cylinder air) was taken in through the intake section 21. Thereafter, as in Comparative Example 1, the gas was sent to the support member 12 without passing through the reduction section 22, and the number of particles in the gas ejected from the ejection holes of the support member 12 was measured.

[0085] The number of particles in each example and comparative example is shown in Table 1. The number of particles shown in the table is the number of particles in 100 L of gas (10 L / min x 10 min).

[0086]

[0087] <Evaluation> Comparative Example 1 revealed that when factory air was used, a relatively large number of particles were contained in the gas. Example 1 and Comparative Example 1 revealed that when factory air was used, the use of the reduction unit 22 reduced the number of particles for all particle sizes. Furthermore, Comparative Example 2 revealed that even when cylinder air was used, a relatively large number of particles were mixed into the gas. Example 2 and Comparative Example 2 revealed that even when cylinder air was used, the use of the reduction unit 22 reduced the number of particles for all particle sizes.

[0088] Example 3: Factory Air Analysis

[0089] In this example, factory air was analyzed. First, factory air was pumped from the building's piping into pipe t, and the air was sprayed onto a carbon repair tape for approximately one hour. The components of the particles that adhered to the tape were analyzed using EDX (Energy Dispersive X-ray Spectroscopy). A scanning electron microscope (Hitachi High-Tech S-3400N) and an EDX detector (Oxford Instruments X-act) were used for the analysis, and particles adhered to six locations on the repair tape were analyzed. Table 2 shows the analysis results for each location.

[0090]

[0091] <Evaluation> In this example, Fe, Cr, Ni, Cu, and Mn were detected, indicating that the tape contained fine particles derived from SUS and the like. Visual observation of the SEM image of the repair tape revealed multiple particles of approximately 1 to 3 μm in size. Fe, Cr, Ni, Cu, and Mn are transition elements, and their ions absorb wavelengths in the visible light range. Therefore, if these elements are mixed into glass, they can cause a decrease in transmittance.

[0092] <Examples 4 and 5: Inspection of foreign matter in glass>

[0093] Example 4 Next, a foreign substance inspection was carried out on the optical glass. In this example, optical glass was produced using the manufacturing apparatus 10 shown in FIG. 1 according to the following procedure. First, glass raw materials were weighed to obtain a predetermined composition and mixed with a dispersion medium to obtain a slurry. Water was used as the dispersion medium. Next, the slurry was placed in a resin ball mill and mixed, and then allowed to dry to obtain a cake. Next, the obtained cake was mixed in an alumina mortar and pressed to form a pellet, and the obtained pellet was fired to produce a sintered body. The sintered body was then placed on the support member 12 of the manufacturing apparatus 10. The composition of Example 4 was the same as that of Example 9, which will be described later.

[0094] Next, gas (factory air) was taken in from the building's piping through pipe t into intake section 21, passed through an air filter functioning as reduction section 22, and ejected from the gas ejection holes in support member 12. The air filter used had a filtration diameter of 0.01 μm and was installed between flow rate adjustment section 24 and support member 12. The ejection of gas supported glass raw material composed of a sintered body in a non-contact manner, and the glass raw material was melted by irradiating it from above with a carbon dioxide laser.

[0095] The melted glass raw material took on an approximately spherical shape due to its own surface tension and was suspended by the gas pressure. Furthermore, when the raw material was completely melted, the laser output was shut off. Next, the glass raw material was melted by restarting the laser output, and then the laser output was shut off. In this way, the glass raw material was melted a total of 10 times to obtain optical glass. In the same manner, a total of 10 optical glasses were obtained. The resulting 10 optical glasses each weighed 4200 mg and had a diameter of 15.5 mm.

[0096] Parallel light was passed through the obtained optical glass using a condenser, and the transmitted light was projected onto a screen to visually check for foreign matter and count the number of foreign matter.

[0097] Comparative Example 3 A sintered body having the same composition as in Example 4 was similarly supported in a non-contact manner on a support member 12. In Comparative Example 3, a reduction section 22 such as an air filter was not provided. Thereafter, the glass raw material was melted a total of five times to obtain optical glass. In the same manner, a total of 22 pieces of optical glass were obtained. The size of the obtained optical glass and the method for measuring foreign matter were the same as in Example 4.

[0098] Tables 3 and 4 show the results of Example 4 and Comparative Example 3.

[0099]

[0100]

[0101] <Evaluation> In Example 4, no foreign matter of any size was found. On the other hand, in Comparative Example 3, the presence of foreign matter was found in 11 of a total of 22 optical glasses. Therefore, it was confirmed that the provision of the reduction section 22 (air filter) reduced foreign matter.

[0102] <Examples 5 to 8, Comparative Examples 4 to 7: Particle reduction effect of reduction unit and influence on transmittance>

[0103] The optical glasses in the following examples were produced using the manufacturing apparatus 10 shown in Figure 1 according to the following procedure. First, glass raw materials selected from oxides were weighed out so as to obtain the compositions (mol %) shown in the following tables. Then, sintered bodies obtained in the same manner as in Example 4 were placed on the support member 12 of the manufacturing apparatus 10.

[0104] Next, gas (factory air) was taken into the intake section 21 through the pipe t from the building's piping, and the gas was ejected from the gas ejection holes of the support member 12, either through or without an air filter functioning as the reduction section 22. When an air filter was used, a filter with a filtration diameter of 5 μm was used in Example 5, and a filter with a filtration diameter of 0.01 μm was used in Examples 6, 7, and 8, and the filter was installed between the flow rate adjustment section 24 and the support member 12. The glass raw material was then melted by irradiating it from above with a carbon dioxide laser while ejecting the gas. The molten glass raw material took on a roughly spherical shape due to its own surface tension and was suspended by the gas pressure. The laser output was then shut off when the raw material was completely melted. At this point, ICP-MS analysis was performed, and the impurity content of the obtained sample U was calculated.

[0105] Refractive index (n ｄ ) and Abbe number (ν ｄ The samples of the examples were processed into a 90-degree prism, and the refractive index was measured by the V-block method using a refractive index measuring instrument (manufactured by Kalnew Optical Industries Co., Ltd.; "KPR-3000"), and the Abbe number and partial dispersion ratio were calculated.

[0106] n ｄ indicates the refractive index of glass for light of 587.562 nm. ｄ ) was calculated from the following formula (1): Ｃ , n Ｆ , and represent the refractive index of the glass for light with wavelengths of 656.273 nm and 486.133 nm, respectively. ｄ = (n ｄ −1) / (n Ｆ -n Ｃ ) (1) The refractive index value was rounded to six decimal places.

[0107] Partial dispersion ratio (P ｇ，Ｆ ) The partial variance ratio (P ｇ，Ｆ ) is the primary variance (n Ｆ -n Ｃ ) partial variance (n ｇ -n Ｆ ) and was calculated using the following formula (2): ｇ indicates the refractive index of the glass for light with a wavelength of 435.835 nm. ｇ，Ｆ) values ​​were rounded to four decimal places. ｇ，Ｆ = (n ｇ -n Ｆ ) / (n Ｆ -n Ｃ ) ... (2)

[0108] Internal transmittance The internal transmittance of each sample was measured using a spectrophotometer (Hitachi High-Tech Science Corporation; "Ultraviolet-Visible-Infrared Spectrophotometer UH4150") to measure the transmittance of a 4-9 mm thick parallel-polished product at wavelengths of 200 to 700 nm, and then the refractive index measurement data was used to remove and correct the contribution to transmittance due to reflectance at each wavelength, and the value was converted to the transmittance for a 10 mm thickness. From the refractive index data obtained by the V-block method for 10 emission lines of h, g, F', F, e, d, C', C, r, and t, fitting was performed using the following dispersion curve equation by the least squares method.

[0109]

[0110] The refractive index value n at each wavelength λ calculated using the dispersion curve equation λ The transmittance T is calculated by taking into account the surface reflectance R of each wavelength and the multiple reflections of the incident light on the front and back surfaces, assuming that there is no internal light absorption. ｔｈ The external transmittance measured value T at a thickness of t mm was calculated by the following formula. ｅｘｐ and T ｔｈ The internal transmittance T (t mm) was calculated using the formula:

[0111]

[0112] Using the internal transmittance T(tmm) at the thickness tmm calculated above, the transmittance value T(10mm) at a thickness of 10mm was calculated using the following formula: ８０ It was decided.

[0113]

[0114] In addition, the internal transmittance is measured in the wavelength range of 200 to 700 nm, and the wavelength at which the internal transmittance at a thickness of 10 mm becomes 80% is defined as λ ８０Table 5 shows the results of Examples 5 to 8, and Table 6 shows the results of Comparative Examples 4 to 7. Furthermore, Fig. 8 shows the internal transmittance (%) of Example 5 and Comparative Example 4, Fig. 9 shows the internal transmittance (%) of Example 6 and Comparative Example 5, Fig. 10 shows the internal transmittance (%) of Example 7 and Comparative Example 6, and Fig. 11 shows the internal transmittance (%) of Example 8 and Comparative Example 7.

[0115]

[0116]

[0117] <Evaluation> Example 5 and Comparative Example 4, Example 6 and Comparative Example 5, Example 7 and Comparative Example 6, and Example 8 and Comparative Example 7 all have the same glass raw material composition. It was confirmed that the provision of the reduction portion 22 reduced transition metals such as Fe. It was also confirmed that the provision of the reduction portion 22 improved internal transmittance. Therefore, it was inferred that the provision of the reduction portion 22 reduced the inclusion of transition elements such as Fe from the gas, which causes a decrease in transmittance, and thus improved internal transmittance was achieved.

[0118] Example 9 and Comparative Example 8: Cake mixing method and its effect on transmittance

[0119] Example 9 The optical glass in Example 9 was produced using the production apparatus 10 shown in FIG. 1 and in the following manner. First, a cake was obtained using weighed glass raw materials, as in Examples 5 to 8. The obtained cake was then mixed using an alumina millstone-type grinder (masscolloider) (manufactured by Masuko Sangyo Co., Ltd.). After mixing, the process up to obtaining the optical glass was the same as in Examples 5 to 8. In order to examine the contribution of the equipment, a reduction section 22 was not installed in the gas flow path.

[0120] Comparative Example 8 The optical glass in Comparative Example 8 was the same as that in Example 9, except that a SUS jaw crusher (BB50 manufactured by Retsch) was used instead of an alumina millstone crusher (masscolloider) when mixing the cake.

[0121] Table 6 shows the results of Example 9 and Comparative Example 8. FIG. 12 is a graph showing the internal transmittance (%) of Example 9 and Comparative Example 8.

[0122]

[0123] A comparison of Example 9 and Comparative Example 8 revealed that an optical glass with higher transmittance can be obtained when mixing glass raw materials using an alumina mass colloidal, compared to when mixing glass raw materials using an SUS jaw crusher. It is presumed that the transmittance of Comparative Example 8 is lower than that of Example 9 because Fe, Cr, or Ni derived from the SUS, the material of the jaw crusher, was mixed into the glass.

[0124] FIG. 13 shows the P of Examples 5 to 9. ｇ.Ｆ and ν ｄ The graph plots the equation P ｇ,Ｆ ≦−0.0020×ν ｄ +0.6535 (30≦ν ｄ ≦60) and (formula) P ｇ,Ｆ ≦−0.0047×ν ｄ +0.7345 (15≦νd≦30). ８０ value (unit: nm) and ν ｄ The line is (equation) λ ８０ ≦−3.05×ν ｄ Represents +475.

[0125] From the above, it was confirmed that the optical glass of each example achieved high transmittance and unique constant values ​​through the float melting process that suppressed the inclusion of transition metals. ｄ ) is 30≦ν ｄ In the region where the partial dispersion ratio (P ｇ,Ｆ ) is (formula) P ｇ,Ｆ ≦−0.0020×ν ｄ +0.6535, and the wavelength (λ ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ It was confirmed that the Abbe number (ν ｄ In the region where the partial dispersion ratio (P ｇ,Ｆ ) is (formula) P ｇ,Ｆ ≦−0.0047×ν ｄ+0.7345, and the wavelength at which the transmittance at a thickness of 10 mm is 80% or less (λ ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ It was confirmed that it met the standard of +475.

[0126] 1...imaging device (interchangeable lens camera), 10...manufacturing apparatus, 11...stage, 12...support member, 13...laser light source, 14 / 15...mirror, 16...radiation thermometer, 17...computer, 18...CCD camera, 19...monitor, 20...gas supply section, 21...intake section, 22...reduction section, 23 / t...pipe, 24...flow rate adjustment section, 25...connection section, L: laser light, S / U: sample, W...upper surface, 101...camera body, 102...lens barrel, 103...lens, 104...sensor chip, 105...glass substrate, 106...multi-chip module, CAM...imaging Device (non-interchangeable lens camera), WL...taking lens, M...liquid crystal monitor, EF...fill-in light emitting unit, B1...release button, B2...function button, 2...multiphoton microscope, 201...pulse laser device, 202...pulse splitting device, 203...beam adjusting unit, 204, 205, 212...dichroic mirror, 206...objective lens, 207, 211, 213...fluorescence detecting unit, 208...condensing lens, 209...pinhole, 210...imaging lens, 3...cemented lens, 301...first lens element, 302...second lens element, 303...cementing member

Claims

1. A glass manufacturing apparatus for manufacturing glass through a process of lowering the temperature of glass raw materials, comprising: a support unit having gas ejection holes on an upper surface and capable of supporting the glass raw materials in a non-contact manner by gas ejected from the gas ejection holes; a heating unit for heating the glass raw materials on the support unit; and a gas supply unit for supplying gas to the gas ejection holes, wherein the gas supply unit has an intake unit for taking in the gas from the outside, and a reduction unit for reducing the number of particles in the gas taken in by the intake unit.

2. The glass manufacturing apparatus according to claim 1, wherein the intake section takes in the gas from a building's piping, a gas cylinder, or a device that takes in gas from the atmosphere.

3. The glass manufacturing apparatus according to claim 1, wherein the intake section has a pipe through which the gas passes, and the intake section has a connection section that connects the pipe with an external pipe.

4. The glass manufacturing apparatus according to claim 3, wherein the connection portion connects the pipe to an external pipe through which the gas passes, the gas being released from a building's piping, a gas cylinder, or a device or piping that takes in gas from the atmosphere.

5. The glass manufacturing apparatus according to any one of claims 1 to 4, wherein the reduction section reduces the number of particles in the gas per 100 L to 1,000 or less.

6. The glass manufacturing apparatus according to any one of claims 1 to 5, wherein the reduction unit reduces particles in the gas so that the total content of Cr, Mn, Fe, Co, Ni, and Cu in the glass is 5 ppm or less in mass terms.

7. The glass manufacturing apparatus according to any one of claims 1 to 6, wherein the reduction section includes an air filter.

8. The glass manufacturing apparatus according to claim 7, wherein the air filter has a filtration diameter of 10 μm or less.

9. The glass manufacturing apparatus according to any one of claims 1 to 8, further comprising a flow rate adjusting unit capable of changing the flow rate of the gas, and the reduction unit is disposed between the flow rate adjusting unit and the gas ejection hole.

10. A glass manufacturing apparatus for manufacturing glass through a process of lowering the temperature of glass raw materials, comprising: a support unit having gas ejection holes on an upper surface and capable of supporting the glass raw materials in a non-contact manner by gas ejected from the gas ejection holes; a heating unit for heating the glass raw materials on the support unit; and a gas supply unit for supplying gas to the gas ejection holes so that the total content of Cr, Mn, Fe, Co, Ni and Cu in the glass is 5 ppm or less by mass.

11. The glass manufacturing apparatus according to any one of claims 1 to 10, wherein the glass raw material is a pressed compact, a sintered compact of the pressed compact, or an aggregate of crystals.

12. A method for producing glass, comprising producing the glass using the production apparatus according to any one of claims 1 to 11.

13. A method for producing glass, comprising: a mixing step of mixing raw materials for the glass to obtain a mixture of the raw materials; a non-contact supporting step of supporting the mixture of the raw materials in a non-contact manner; a heating step of heating the mixture of the raw materials to form a molten liquid; and a cooling step of cooling the mixture of the raw materials in the molten liquid state to obtain glass, wherein in the mixing step, the raw materials are mixed using a tool that is substantially free of Cr, Mn, Fe, Co, Ni, and Cu in parts that come into contact with the raw materials.

14. The method for producing glass according to claim 13, wherein the volume of the device is 100 mL or more.

15. Abbe number (ν ｄ ) is 30≦ν ｄ ≦60, partial dispersion ratio (P ｇ,Ｆ ) is (formula) P ｇ,Ｆ ≦−0.0020×ν ｄ +0.6535, the wavelength at which the transmittance at a thickness of 10 mm is 80% or less (λ ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ Glass that meets +475.

16. Abbe number (ν ｄ ) is 15≦νd≦30, partial dispersion ratio (P ｇ,Ｆ ) is (formula) P ｇ,Ｆ ≦−0.0047×ν ｄ +0.7345, the wavelength at which the transmittance at a thickness of 10 mm is 80% or less (λ ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ Glass that meets +475.

17. In mole percent, B ２ O ３ , SiO ２ , P ２ O ５ and As ２ O ３ The total content of (B ２ O ３ +SiO ２ +P ２ O ５ +As ２ O ３ ): 40% or less, Li ２ O.K. ２ O, Na ２ O, P ２ O ５ and B ２ O ３ The total content of (Li ２ O+K ２ O + Na ２ O+P ２ O ５ +B ２ O ３ ): 5% or less, La ２ O ３ , BaO, CaO, MgO, Y ２ O ３ , Gd ２ O ３ , Al ２ O ３ , TiO ２ , Nb ２ O ５ , ZrO ２ and Ta ２ O ５ Total content (La ２ O ３ +BaO+CaO+MgO+Y ２ O ３ +Gd ２ O ３ +Al ２ O ３ + TiO ２ +Nb ２ O ５ + ZrO ２ +Ta ２ O ５ 17. The glass of claim 15 or 16, wherein:

18. The glass according to any one of claims 15 to 17, having a total content of Cr, Mn, Fe, Co, Ni, and Cu of 5 ppm or less by mass.

19. The glass of any one of claims 15 to 18, which is a float melt glass.

20. In mole percent, B ２ O ３ , SiO ２ , P ２ O ５ and As ２ O ３ The total content of (B ２ O ３ +SiO ２ +P ２ O ５ +As ２ O ３ ): 40% or less, Li ２ O.K. ２ O, Na ２ O, P ２ O ５ and B ２ O ３ The total content of (Li ２ O+K ２ O + Na ２ O+P ２ O ５ +B ２ O ３ ): 5% or less, La ２ O ３ , BaO, CaO, MgO, Y ２ O ３ , Gd ２ O ３ , Al ２ O ３ , TiO ２ , Nb ２ O ５ , ZrO ２ and Ta ２ O ５ Total content (La ２ O ３ +BaO+CaO+MgO+Y ２ O ３ +Gd ２ O ３ +Al ２ O ３ + TiO ２ +Nb ２ O ５ + ZrO ２ +Ta ２ O ５ ): 60% or more, and the total content of Cr, Mn, Fe, Co, Ni and Cu: 5 ppm or less, calculated on a mass basis.

21. In mole percent, B ２ O ３ , SiO ２ , P ２ O ５ and As ２ O ３ The total content of (B ２ O ３ +SiO ２ +P ２ O ５ +As ２ O ３ ): 40% or less, Li ２ O.K. ２ O, Na ２ O, P ２ O ５ and B ２ O ３ The total content of (Li ２ O+K ２ O + Na ２ O+P ２ O ５ +B ２ O ３ ): 5% or less, La ２ O ３ , BaO, CaO, MgO, Y ２ O ３ , Gd ２ O ３ , Al ２ O ３ , TiO ２ , Nb ２ O ５ , ZrO ２ and Ta ２ O ５ Total content (La ２ O ３ +BaO+CaO+MgO+Y ２ O ３ +Gd ２ O ３ +Al ２ O ３ + TiO ２ +Nb ２ O ５ + ZrO ２ +Ta ２ O ５ ): 60% or more, and the wavelength (λ) at which the transmittance at a thickness of 10 mm is 80% or less ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ Glass that meets +475.

22. An optical glass using the glass according to any one of claims 15 to 21.

23. An optical element using the optical glass according to claim 22.

24. An optical device using the optical element according to claim 23.

25. The wavelength (λ) at which the transmittance at a thickness of 10 mm is 80% or less ８０ ) is (equation) λ ８０ ≦−3.05×ν ｄ Floating molten glass that meets +475.

26. A glass manufacturing apparatus for manufacturing glass through a process of lowering the temperature of glass raw materials, comprising: a support part having gas ejection holes on an upper surface and capable of supporting the glass raw materials in a non-contact manner by gas ejected from the gas ejection holes; a heating part for heating the glass raw materials on the support part; and a gas supply part for supplying gas to the gas ejection holes at a rate of 1,000 particles or less per 100 L.

27. A glass manufacturing method for manufacturing glass through a step of lowering the temperature of glass raw materials, comprising a non-contact supporting step of supporting the glass raw materials in a molten state in a non-contact manner using a gas having a particle count of 1,000 or less per 100 L.

28. A glass manufacturing method for manufacturing glass through a step of lowering the temperature of glass raw materials, comprising a non-contact supporting step of supporting the glass raw materials in a molten state in a non-contact manner using a gas such that the total content of Cr, Mn, Fe, Co, Ni and Cu in the glass is 5 ppm or less by mass.

Images