TW201937197A - Optical glass being high in heat impact resistance and impact resistance - Google Patents

Abstract

The invention provides an optical glass with refractive index (nd) and Abbe number (vd) within a required range, being high in heat impact resistance and impact resistance, or not easy to reduce light transmissivity through time. The optical glass, by mass percentage of oxide, comprises 30.0% to 80.0% of SiO2, 1.0% to 30.0% of B2O3, and 1.0% to 30.0% of Rn2O (wherein Rn is at least one of Li, Na, and K), and has a refractive index (nd) of 1.47 to 1.54 and an Abbe number (vd) ranging from 60 to 68.

Description

Optical glass

The present invention relates to an optical glass, and more particularly, to an optical glass having high thermal shock resistance.

Optical glass is used in the fields of various optical devices such as digital cameras or vedio cameras, or image playback (projection) devices such as projectors or projection televisions. In these machines, it can be used for the lens or 稜鏡 of the optical system.

Here, as the optical glass having an optical constant having a refractive index (n _d ) of 1.47 to 1.54 and an Abbe number (ν _d ) in a range of 60 to 68, typical glasses represented by Patent Documents 1 to 4 are known.组合 物。 Composition.
[Prior technical literature]
[Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2001-089183.
Patent Document 2: Japanese Patent Laid-Open No. 2002-020136.
Patent Document 3: Japanese Patent Laid-Open No. 2002-356348.
Patent Document 4: Japanese Patent Laid-Open No. 2003-341557.

[Problems to be Solved by the Invention]

The optical glasses described in Patent Documents 1 to 4 are mainly used for optical devices such as cameras or projectors.

However, in the application of the projector, since around 2013, a laser light source has gradually been used instead of incandescent light as a light source, and the following problems have arisen: laser light with high linearity and high energy and energy density is irradiated to the lens or prism. The optical glass of the mirror is for this reason the optical glass is rapidly heated, and the thermal shock caused by the heating causes the optical glass to be damaged.

In addition, by using a laser light source as a light source, the miniaturization of the optical system is further advanced, and the miniaturization of a laser projector using the laser light source is further advanced. On the other hand, the heat radiation of the laser light source is greater than that of the incandescent light, so the optical system or the entire optical machine is easy to carry heat. For this reason, the optical glass that constitutes the lens or grate is heated, and the thermal shock caused by the heating also causes Broken optical glass.

This kind of breakage problem of optical glass caused by thermal shock also arises in applications such as surveillance cameras, action cameras, automotive cameras or headlights. Especially in these applications for outdoor use, the optical glass or the entire optical device is rapidly heated by direct sunlight, or is rapidly cooled by water such as rain after heating, so the same problem occurs that the optical glass is damaged by thermal shock.

On the other hand, the optical glass described in Patent Documents 1 to 4 is mainly used for an optical device that is used in a substantially fixed state like a camera or a projector. However, in recent years, optical devices have also been used in motion cameras mounted on drone-like displacement means, or in automotive cameras or headlights mounted on transporters such as automobiles, and demand can be more resistant to drops, Optical glass with physical impact during landing or driving.

Such optical glass, which is more resistant to physical shock, is also demanded in applications for outdoor use, such as surveillance camera applications. Especially in these applications for outdoor use, strong winds or flying objects caused by it touch the optical glass, which causes a physical impact.

On the other hand, in the application of a projector or a laser device, a laser oscillator, and a laser processing machine that operate powerful laser light, the problem of coloring optical glass arises. For example, in the use of projectors, since around 2013, laser light has gradually been used instead of incandescent light, resulting in the following problems: laser light with high linearity and high energy and energy density is irradiated to the optical glass constituting a lens or a chirp. For this reason, the light transmittance of optical glass decreases over time.

The problem of lowering the light transmittance of this optical glass also arises in applications such as surveillance cameras, action cameras, automotive cameras, or headlights. Especially in these applications for outdoor use, direct sunlight is irradiated to the optical glass, which causes the same problem.

The present invention has been made in view of the above-mentioned problems, and its purpose is to obtain a refractive index (n _d ) and an Abbe number (ν _d ) in a desired range, and has high thermal shock resistance, high impact resistance, or is unlikely to occur. Optical glass with reduced light transmission caused by time.
[Means to solve the problem]

The present inventors repeated diligent experimental research in order to solve the above-mentioned problems, and as a result, they found that optical glasses containing a SiO ₂ component, a B ₂ O ₃ component, and an alkali metal component can obtain high thermal shock resistance, high impact resistance, Or it is not easy to produce a reduction in light transmittance caused by the passage of time, and the present invention has been completed. Specifically, the present invention provides the following.

(1) An optical glass, based on the mass% of the oxide basis, the SiO ₂ component is 30.0% to 80.0%, the B ₂ O ₃ component is 1.0% to 30.0%, and the Rn ₂ O component (where Rn is Li (At least one of Na, K) is 1.0% to 30.0%, and has an optical constant in the range of refractive index (n _d ) of 1.47 to 1.54 and Abbe number (ν _d ) of 60 to 68.

(2) The optical glass according to (1), wherein the average linear expansion coefficient α [× 10 ^-7 / ° C] and Young's modulus E [× 10 ⁸ N / m ^{2 at} -30 ° C to + 70 ° C The product α × E is 60,000 or less.

(3) The optical glass according to (2) is an optical device used for being heated by irradiation of light.

(4) The optical glass according to (2) or (3) is used for surveillance cameras, action cameras, laser projectors, headlights, or automotive cameras.

(5) The optical glass according to (1), wherein when the 23.8 g steel ball is freely dropped onto the optical glass, the minimum height of the optical glass breakage is 100 cm or more.

(6) The optical glass according to (5) is an optical device for outdoor use or an optical device with a displacement means.

(7) The optical glass according to (5) or (6), which is used for surveillance cameras, action cameras, car cameras, or headlights.

(8) The optical glass described in (1) has an optical constant in the range of refractive index (n _d ) from 1.47 to 1.54 and Abbe number (ν _d ) in the range of 60 to 68, according to the Japan Optical Glass Industry Association Standard JOGIS04 -2005 "Measurement method of solarization effect of optical glass" The amount of degradation when measuring the spectral transmittance before and after irradiation with light was 1% or less.

(9) The optical glass according to (8) is an optical device used for incident laser light or direct sunlight.

(10) The optical glass according to (8) or (9) is used for laser projectors, laser processors, laser devices, laser oscillators or headlights.
[Inventive effect]

According to the present invention, it is possible to provide a refractive index (n _d ) and an Abbe number (ν _d ) in a desired range, and have high thermal shock resistance, high impact resistance, or difficulty in generating light transmittance due to passage of time. The lowered optical glass.

In particular, according to the present invention, it is possible to provide an optical glass having a refractive index (n _d ) and an Abbe number (ν _d ) in a desired range, and can also be used for applications that are liable to cause damage due to thermal shock.

In addition, according to the present invention, it is possible to provide an optical glass having a refractive index (n _d ) and an Abbe number (ν _d ) in a desired range and not easily broken even when subjected to a strong impact.

In addition, according to the present invention, it is possible to obtain an optical glass having a refractive index (n _d ) and an Abbe number (ν _d ) in a desired range and less likely to cause a decrease in light transmittance due to passage of time.

For the optical glass of the present invention, the optical glass contains 30.0% to 80.0% of SiO ₂ component, 1.0% to 30.0% of B ₂ O ₃ component, and 1.0% to 30.0% of Rn, based on the mass% of the oxide basis. ₂ O component (where Rn is at least any one of Li, Na, and K), and has an optical constant in the range of refractive index (n _d ) of 1.47 to 1.54 and Abbe number (ν _d ) of 60 to 68 .

Among them, the optical glass of the first embodiment contains 30.0% to 80.0% of SiO ₂ component, 1.0% to 30.0% of B ₂ O ₃ component, and 1.0% to 30.0% of Rn ₂ O, based on the mass% of the oxide basis. A component (in the formula, Rn is at least any one of Li, Na, and K), and has an optical constant in the range of refractive index (n _d ) of 1.47 to 1.54 and Abbe number (ν _d ) of 60 to 68,- The product of the average linear expansion coefficient α [× 10 ^-7 / ° C] and Young's modulus E [× 10 ⁸ N / m ² ] at 30 ° C. to + 70 ° C. is not more than 60,000. An optical glass having a high thermal shock resistance can be obtained in an optical glass containing a SiO ₂ component, a B ₂ O ₃ component, and an alkali metal component. Therefore, it is possible to obtain an optical glass having a refractive index (n _d ) and an Abbe number (ν _d ) in a desired range, and can also be used for applications that are liable to cause damage due to thermal shock.

In addition, the optical glass of the second embodiment contains 30.0% to 80.0% of SiO ₂ component, 1.0% to 30.0% of B ₂ O ₃ component, and 1.0% to 30.0% of Rn ₂ O, based on the mass% of the oxide basis. A component (where Rn is at least any one of Li, Na, and K), and has an optical constant in the range of refractive index (n _d ) of 1.47 to 1.54 and Abbe number (ν _d ) of 60 to 68, in When a 23.8 g steel ball is freely dropped onto the optical glass, the minimum height of the optical glass damage is 100 cm or more. According to the present invention, an optical glass having a high impact resistance can be obtained in an optical glass containing a SiO ₂ component, a B ₂ O ₃ component, and an alkali metal component. Therefore, it is possible to obtain an optical glass having a refractive index (n _d ) and an Abbe number (ν _d ) in a desired range and not easily broken even when subjected to a strong impact.

In addition, the optical glass according to the third embodiment contains 30.0% to 80.0% of SiO ₂ component, 1.0% to 30.0% of B ₂ O ₃ component, and 1.0% to 30.0% of Rn ₂ O in terms of mass basis of oxide basis. A component (where Rn is at least any one of Li, Na, and K), and has an optical constant in the range of refractive index (n _d ) of 1.47 to 1.54 and Abbe number (ν _d ) of 60 to 68, based on The Japan Optical Glass Industry Association standard JOGIS04-2005 "Measurement method for the exposure of optical glass" measures the amount of degradation when measuring the spectral transmittance before and after the irradiation of light is less than 1%. In optical glass containing a SiO ₂ component, a B ₂ O ₃ component, and an alkali metal component, an optical glass having a small exposure effect can be obtained. Therefore, it is possible to obtain an optical glass in which the refractive index (n _d ) and the Abbe number (ν _d ) are within a desired range and it is not easy to cause a reduction in light transmittance due to the passage of time.

Hereinafter, each embodiment of the optical glass of this invention is demonstrated in detail, However, This invention is not limited at all by the following embodiment, It can implement suitably by changing suitably within the range of the objective of this invention. In addition, regarding overlapping portions of the description, the description may be appropriately omitted, but the gist of the invention is not limited.

Hereinafter, the composition range of each component which comprises the optical glass of this invention is demonstrated. Unless otherwise specified in the present specification, the content of each component is expressed in terms of mass% relative to the total mass of the glass in terms of the oxide-equivalent composition. Here, the "oxide conversion composition" refers to a case where oxides, complex salts, metal fluorides, and the like used as raw materials of the glass constituents of the present invention are all decomposed during melting and changed to oxides. The total mass of the produced oxide is 100% by mass, and the composition of each component contained in the glass is shown.

＜ About essential ingredients and optional ingredients ＞
The SiO ₂ component is an indispensable component that is indispensable as a glass-forming oxide and is a component that reduces the average linear expansion coefficient of glass. In addition, it is a component for improving the chemical durability of glass.
In particular, by containing an SiO ₂ component of 30.0% or more, the color of glass can be reduced, devitrification resistance can be improved, and chemical durability and impact resistance can be improved. In addition, the Young's modulus can be reduced. Therefore, the lower limit of the content of the SiO ₂ component is preferably 30.0%, more preferably 40.0%, still more preferably 46.0%, still more preferably 50.0%, still more preferably 55.0%, and even more preferably 60.0%.
On the other hand, by setting the content of the SiO ₂ component to 80.0% or less, it is possible to suppress an increase in the glass transition point or a yield point and suppress a decrease in the refractive index. Therefore, the upper limit of the content of the SiO ₂ component is preferably 80.0%, more preferably 78.0%, still more preferably 74.0%, still more preferably 70.0%, and even more preferably 65.0%.

The B ₂ O ₃ component is an indispensable component that is an indispensable component of glass-forming oxides, and is a component for obtaining a homogeneous glass in order to reduce the melt viscosity.
In particular, by containing a B ₂ O ₃ component of 1.0% or more, the devitrification resistance of the glass can be improved, and the dispersion of the glass can be reduced. In addition, the Young's modulus can be reduced. Therefore, the lower limit of the content of the B ₂ O ₃ component is preferably 1.0%, more preferably 3.0%, still more preferably 6.0%, still more preferably 10.0%, and even more preferably 14.0%.
On the other hand, by setting the content of the B ₂ O ₃ component to 30.0% or less, a higher refractive index can be easily obtained, and deterioration in chemical durability and impact resistance can be suppressed. Therefore, the content of the B ₂ O ₃ component is preferably 30.0%, more preferably 25.0%, still more preferably 22.0%, and still more preferably 19.0%.

The total amount of the Rn ₂ O component (where Rn is one or more selected from the group consisting of Li, Na, and K) is preferably 1.0% to 30.0%.
In particular, by setting the total amount to 1.0% or more, the glass transition point or yield point can be reduced, the melting property at the time of glass production can be improved, and the exposure effect of glass can be reduced. Therefore, the lower limit of the mass sum of the Rn ₂ O component is preferably 1.0%, more preferably 5.0%, still more preferably 8.0%, still more preferably 11.0%, and even more preferably 12.5%.
On the other hand, by setting the total amount to 30.0% or less, the refractive index of the glass is not easily reduced, the chemical durability of the glass can be improved, and the devitrification resistance can be improved. Furthermore, it is possible to suppress a significant increase in the Young's modulus. Therefore, the mass sum of the Rn ₂ O component is preferably 30.0%, more preferably 26.0%, still more preferably 22.0%, still more preferably 18.0%, and even more preferably 16.0%.

The Li ₂ O component is an optional component that can improve the meltability of glass, reduce the glass transition point, and improve the moldability at the time of press molding when the content of Li ₂ O exceeds 0%. Therefore, the lower limit of the content of the Li ₂ O component may be more than 0%, more preferably 2.0%, still more preferably 3.0%, still more preferably 4.0%, and even more preferably 5.5%.
On the other hand, by setting the content of the Li ₂ O component to 20.0% or less, the refractive index of the glass is not easily reduced, the chemical durability of the glass can be improved, and the devitrification resistance can be improved. Therefore, the upper limit of the content of the Li ₂ O component is preferably 20.0%, more preferably 15.0%, still more preferably 11.0%, and still more preferably 8.0%.

When the content of Na ₂ O is more than 0%, it is an optional component that can improve the melting property of the glass, increase the devitrification resistance of the glass, and reduce the glass transition point.
On the other hand, by setting the content of the Na ₂ O component to 15.0% or less, the refractive index of the glass is not easily reduced, the chemical durability of the glass can be improved, and a large increase in the Young's modulus can be suppressed. Therefore, the content of the Na ₂ O component is preferably 15.0%, more preferably 10.0%, still more preferably 7.0%, and still more preferably 4.0%.

When the K ₂ O component is more than 0%, it is an optional component that can improve the melting property of the glass, increase the devitrification resistance of the glass, and reduce the glass transition point. Therefore, the lower limit of the content of the K ₂ O component is preferably more than 0%, more preferably 2.0%, and still more preferably 6.6%.
On the other hand, by setting the content of the K ₂ O component to 25.0% or less, the refractive index of the glass is not easily reduced, the chemical durability of the glass can be improved, and a large increase in the Young's modulus can be suppressed. Therefore, the content of the K ₂ O component is preferably 25.0%, more preferably 23.0%, further preferably 20.0%, still more preferably 17.0%, still more preferably 14.0%, or even more preferably 9.0% as the upper limit. .

When the content of Al ₂ O ₃ is more than 0%, it is an arbitrary component that can reduce the average linear expansion coefficient of glass. In addition, in order to improve the chemical durability of the glass, and to suppress the phase separation of the glass, it also improves the impact resistance or devitrification resistance. Therefore, the content of the Al ₂ O ₃ component may be more than 0%, more preferably 1.0%, still more preferably 3.0%, and still more preferably 5.0%.
On the other hand, by reducing the content of the Al ₂ O ₃ component to 23.0% or less, it is possible to suppress the reduction in devitrification resistance of the glass caused by the excessive content of these components, to suppress the increase in the yield point of the glass, and to reduce the increase. The viscosity of the glass during forming facilitates press forming. Therefore, the content of the Al ₂ O ₃ component is preferably 23.0%, more preferably 19.0%, still more preferably 15.0%, still more preferably 10.0%, and still more preferably 9.0% as the upper limit.

The total amount of the SiO ₂ component, the B ₂ O ₃ component, and the Al ₂ O ₃ component is preferably 50.0% or more. Thereby, a desired refractive index and Abbe number can be obtained, a low yield point and viscosity suitable for press forming can be obtained, and excellent chemical durability, devitrification resistance, and impact resistance can be obtained. Therefore, the mass (SiO ₂ + B ₂ O ₃ + Al ₂ O ₃ ) system is preferably 50.0%, more preferably 60.0%, further preferably 68.0%, further preferably 75.0%, and even more preferably 83.0%. Is the lower limit. On the other hand, the total amount may be set to an upper limit of preferably 98.0%, more preferably 94.0%, and still more preferably 90.0%.

When the content of TiO ₂ is more than 0%, it can reduce the coloration caused by the exposure of glass, improve the chemical durability, increase the refractive index of glass, adjust the Abbe number to low, and improve the loss resistance. Any component of permeability. Therefore, the lower limit of the content of the TiO ₂ component is preferably more than 0%, more preferably 0.01%, still more preferably 0.05%, and still more preferably 0.10%.
On the other hand, by setting the content of TiO ₂ to 10.0% or less, it is possible to reduce the coloration of the glass and increase the visible light transmittance, and further, it is possible to suppress the decrease in the Abbe number. Therefore, the content of the TiO ₂ component is preferably 10.0%, more preferably 5.0%, still more preferably 3.0%, and still more preferably 1.0%.

When the content of the Nb ₂ O ₅ component and the WO ₃ component is more than 0%, the components can increase the refractive index of the glass and improve the devitrification resistance. In addition, the WO ₃ component is a component that can reduce the glass transition point.
On the other hand, by setting the contents of the Nb ₂ O ₅ component and the WO ₃ component to 10.0% or less, respectively, it is possible to reduce the coloration of the glass and increase the visible light transmittance, and further, it is possible to suppress a decrease in the Abbe number. Therefore, the contents of the Nb ₂ O ₅ component and the WO ₃ component are preferably 10.0% or less, more preferably less than 5.0%, more preferably less than 3.0%, and still more preferably less than 1.0%.

When the ZnO component is more than 0%, it is an optional component that can reduce the glass transition point or yield point, can adjust the viscosity during molding, and can improve chemical durability. Therefore, the lower limit of the content of the ZnO component is preferably more than 0%, more preferably 0.1%, and still more preferably 0.5%.
On the other hand, by setting the content of the ZnO component to 15.0% or less, the average linear expansion coefficient of glass can be reduced. In addition, reduction in devitrification resistance can be suppressed. Therefore, the content of the ZnO component is preferably 15.0%, more preferably 10.0%, still more preferably 6.0%, and still more preferably 4.0% as an upper limit.

When the MgO component, CaO component, SrO component, and BaO component are contained in excess of 0%, any component that can improve the melting property of the glass raw material or the devitrification resistance of the glass.
On the other hand, by setting the content of each of the MgO component, CaO component, SrO component, and BaO component to 10.0% or less, the average linear expansion coefficient of glass can be reduced. In addition, it is possible to suppress a decrease in the refractive index or a reduction in devitrification resistance due to the excessive content of these components. Therefore, the contents of the MgO component, the CaO component, the SrO component, and the BaO component are preferably 10.0% or less, more preferably less than 5.0%, further preferably less than 3.0%, and even more preferably less than 1.0%.

The total (mass) of the content of the RO component (wherein R is one or more selected from the group consisting of Mg, Ca, Sr, and Ba) is preferably 12.0% or less. Accordingly, it is possible to suppress a reduction in the refractive index of the glass or a reduction in devitrification resistance due to the excessive content of the RO component. Therefore, the mass sum of the RO component is preferably 12.0% or less, more preferably less than 10.0%, more preferably less than 5.0%, still more preferably less than 3.0%, and still more preferably less than 1.0%.

When the content of La ₂ O ₃ component, Gd ₂ O ₃ component, Y ₂ O ₃ component, and Yb ₂ O ₃ component exceeds 0%, it is an arbitrary component that can increase the refractive index of glass and increase the Abbe number.
On the other hand, by setting the content of each of the La ₂ O ₃ component, the Gd ₂ O ₃ component, the Y ₂ O ₃ component, and the Yb ₂ O ₃ component to 10.0% or less, it is possible to suppress an increase in the refractive index more than necessary, and Can improve the devitrification resistance of glass. Therefore, the contents of the La ₂ O ₃ component, the Gd ₂ O ₃ component, the Y ₂ O ₃ component, and the Yb ₂ O ₃ component are preferably set to be preferably 10.0% or less, more preferably less than 5.0%, and even more preferably less than 3.0. %, More preferably less than 1.0%.

The sum (mass sum) of the content (mass) of the Ln ₂ O ₃ component (in the formula, Ln is one or more selected from the group consisting of La, Gd, Y, and Yb) is preferably 10.0% or less.
By setting the sum to 10.0% or less, it is possible to suppress an increase in the refractive index more than necessary, and to improve the devitrification resistance of the glass. Therefore, the mass sum of the Ln ₂ O ₃ component is preferably 10.0% or less, more preferably less than 5.0%, still more preferably less than 3.0%, and still more preferably less than 1.0%.

When the P ₂ O ₅ component is contained in an amount exceeding 0%, it is an arbitrary component that can improve the devitrification resistance of the glass.
On the other hand, by reducing the content of the P ₂ O ₅ component to 10.0% or less, it is possible to suppress a decrease in the chemical durability, particularly the water resistance, of the glass. Therefore, the content of the P ₂ O ₅ component is preferably 10.0% or less, more preferably less than 5.0%, still more preferably less than 3.0%, and still more preferably less than 1.0%.

When the GeO ₂ component is contained in an amount exceeding 0%, it is an optional component that can increase the refractive index of glass and improve the devitrification resistance. However, since the price of GeO ₂ -based raw materials is high, if the amount of GeO ₂ is large, the material cost becomes high. Therefore, the content of the GeO ₂ component is preferably 10.0% or less, more preferably less than 5.0%, even more preferably less than 3.0%, still more preferably less than 1.0%, and most preferably not contained.

A ZrO ₂ component is an arbitrary component which contributes to high refractive index and low dispersion of glass, and improves the devitrification resistance of glass when it contains more than 0%.
On the other hand, by reducing the content of the ZrO ₂ component to 10.0% or less, it is possible to suppress a reduction in devitrification resistance of the glass due to an excessive content of the ZrO ₂ component. Therefore, the content of the ZrO ₂ component is preferably 10.0% or less, more preferably less than 5.0%, even more preferably less than 3.0%, and still more preferably less than 1.0%.

When the content of Ta ₂ O ₅ is more than 0%, it is an optional component that can increase the refractive index of glass, improve devitrification resistance, and improve the viscosity of molten glass.
On the other hand, by setting the content of the expensive Ta ₂ O ₅ component to 10.0% or less, the material cost of the glass is reduced, so that a cheaper optical glass can be produced. In addition, the melting temperature of the raw material is lowered, and the energy required for the melting of the raw material is reduced, so the manufacturing cost of the optical glass can also be reduced. Therefore, the content of the Ta ₂ O ₅ component is preferably 10.0% or less, more preferably less than 5.0%, still more preferably less than 3.0%, and still more preferably less than 1.0%.

When the content of the Bi ₂ O ₃ component and the TeO ₂ component is more than 0%, the components can increase the refractive index and lower the glass transition point.
On the other hand, by setting the content of the Bi ₂ O ₃ component to 10.0% or less, the devitrification resistance of the glass can be improved, and the coloration of the glass can be reduced to improve the visible light transmittance.
In addition, TeO ₂ has a problem in that when the glass raw material is melted by using a crucible made of platinum or a melting tank formed of platinum in a portion in contact with the molten glass, alloying may occur with platinum.
Therefore, the contents of the Bi ₂ O ₃ component and the TeO ₂ component are preferably 10.0% or less, more preferably less than 5.0%, more preferably less than 3.0%, and still more preferably less than 1.0%.

When the content of the SnO ₂ component is more than 0%, it is an optional component that can reduce the oxidation of the molten glass to be clarified and improve the visible light transmittance of the glass.
On the other hand, by setting the content of the SnO ₂ component to 3.0% or less, it is possible to reduce the coloration of the glass or the devitrification of the glass due to the reduction of the molten glass. In addition, since the alloying of the SnO ₂ component and the melting equipment (especially noble metals such as Pt) is reduced, the life of the melting equipment can be extended. Therefore, the content of the SnO ₂ component is preferably 3.0%, more preferably 1.0%, and still more preferably 0.5% as an upper limit.

The Sb ₂ O ₃ component is an arbitrary component capable of defoaming the molten glass when it contains more than 0%.
On the other hand, if the content of the Sb ₂ O ₃ component is too large, the transmittance in the short wavelength region of the visible light region is deteriorated. In addition, the exposure effect of glass becomes large. Therefore, the upper limit of the content of the Sb ₂ O ₃ component is preferably 2.0%, more preferably 1.0%, and still more preferably 0.5%.

In addition, the component which clarifies and defoams glass is not limited to the above-mentioned Sb ₂ O ₃ component, and a clarifier, a defoamer, or a combination of these known in the field of glass production can be used.

＜ About ingredients that should not be contained ＞
Next, components which should not be contained in the optical glass of the present invention and components which should not be contained are described.

If necessary, other components may be added within a range that does not impair the characteristics of the glass of the present invention. However, each of the transition metal components such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo other than Ti, Zr, Nb, W, La, Gd, Y, Yb, and Lu has: When it is contained in a small amount or in combination, the glass will also be colored and absorb at a specific wavelength in the visible light region. Therefore, it is preferably not substantially contained in optical glass using a wavelength in the visible light region.

In addition, lead compounds such as PbO and arsenic compounds such as As ₂ O ₃ are components having a high environmental load, and are therefore preferably not substantially contained, that is, they are not contained except for inevitable mixing.

Furthermore, the components of Th, Cd, Tl, Os, Be, and Se have tended to be restricted as harmful chemical substances in recent years. They are not only the manufacturing steps of glass, but also the processing steps, and the points after productization. Measures for environmental countermeasures. Therefore, when it is important to take environmental influence into consideration, it is preferable not to contain these components substantially.

＜＜ Manufacturing method ＞＞
The optical glass of this invention is produced as follows, for example. That is, it is produced by uniformly mixing raw materials such as oxides, carbonates, nitrates, and hydroxides so that each component falls within a predetermined content range, and putting the produced mixture into a platinum crucible, and according to the glass composition The melting difficulty is melted in an electric furnace at a temperature range of 1200 ° C to 1500 ° C for 2 hours to 4 hours. After being homogenized by stirring, it is lowered to an appropriate temperature and then cast into a mold for slow cooling.

<< Physical Properties >>
The optical glass of the present invention preferably has a high Abbe number (low dispersion). In particular, the Abbe number (ν _d ) of the optical glass of the present invention is preferably 60 as the lower limit, and more preferably 68, more preferably 65 as the upper limit. With such a low dispersion, even if it is a single lens, the focus shift (chromatic aberration) caused by the wavelength of light is small, so when, for example, the optical glass is used in a camera, a wider-angle photography can be performed . In addition, by having such a low dispersion, for example, when it is combined with an optical device having a high dispersion (low Abbe number), high imaging characteristics can be achieved.

In addition, the refractive index (n _d ) of the optical glass of the present invention is preferably 1.47, more preferably 1.48, as the lower limit. The upper limit of the refractive index may also be preferably 1.54, more preferably 1.53.

In particular, the optical glass of the first embodiment can achieve high imaging characteristics and the like as well as miniaturize the optical system. Even in this case, it is a glass that is unlikely to be damaged by thermal shock.
In particular, the optical glass of the first embodiment is preferably a product of an average linear expansion coefficient α [× 10 ^-7 / ° C] and a Young's modulus E [× 10 ⁸ N / m ² ] at -30 ° C to + 70 ° C. α × E is 60,000 or less.
Previously, it has been known that the temperature difference θ that can be tolerated when the glass is rapidly cooled is proportional to the inverse of the above-mentioned α × E (Everett or Stott Irvine formula). Therefore, if it is a glass with a small value of α × E, even if the glass is subjected to a rapid temperature change with a larger temperature difference to give a thermal shock, the glass may not be easily damaged.

The optical glass of the first embodiment preferably has a small average linear expansion coefficient (α). In particular, the average linear expansion coefficient of the optical glass of the first embodiment at -30 ° C to + 70 ° C is preferably 100 × 10 ^-7 K ^-1 , more preferably 90 × 10 ^-7 K ^-1 , and more preferably An upper limit is set to 80 × 10 ^-7 K ^-1 . With this, even if the optical glass is heated locally and rapidly, the stress accumulated in the portion is reduced, so that it is not easy to damage the glass. In addition, the influence on the imaging characteristics and the like caused by the stress caused by thermal expansion can be reduced.

On the other hand, the optical glass of the first embodiment may have a small Young's modulus (E). In particular, the Young's modulus of the optical glass of the first embodiment may be preferably 1100 × 10 ⁸ N / m ² , more preferably 1000 × 10 ⁸ N / m ² , and even more preferably 900 × 10 ⁸ N / m ^{2 is} set to the upper limit.

In addition, the optical glass of the second embodiment can achieve high imaging characteristics and the like as well as miniaturize the optical system. Even in this case, it is a glass with high impact resistance.
In particular, the optical glass of the second embodiment allows a 23.8 g (approximately 1.8 cm in diameter) steel ball made of SUJ-2 to fall freely to a rubber made of natural rubber having a width of 50 mm × 50 mm or more and a thickness of 5 mm. The minimum height of at least a part of the optical glass that is damaged due to cracks, defects, or ruptures when the center of the main surface of the optical double-sided polished optical glass with a diameter of 30 mm and a thickness of 2 mm is left on the main surface of the sheet "Result of falling ball test") is 100 cm or more. Therefore, even if strong wind or flying objects touch the optical glass, damage to the optical device is reduced. In addition, the optical device is not easily damaged due to the impact caused by the drop of the machine equipped with the optical glass, the shaking caused when the machine is displaced (moved), or the reaction caused when the machine is stopped by the displacement means. Therefore, even when the optical glass of the second embodiment is used in an outdoor optical device or a device having a displacement means, the optical device or the device can be extended in life. Therefore, as a result of the falling ball test of the optical glass of the second embodiment, the lower limit is preferably 100 cm, more preferably 105 cm, and most preferably 110 cm.

In addition, the optical glass of the third embodiment can achieve such high imaging characteristics and reduce the size of the optical system. Even in this case, it is a glass that is unlikely to cause a decrease in light transmittance due to the passage of time. .
In particular, the optical glass system of the third embodiment has a degradation amount of the spectral transmittance of light having a strong peak at a wavelength of 365 nm of 1.0% or less. Therefore, even if blue light (wavelength 450 nm) or direct sunlight, which is mostly used as laser light, is irradiated to the optical glass for a long time, degradation of the spectral transmittance due to the passage of time is unlikely to occur. Therefore, even when the optical glass of the third embodiment is used in an optical device that operates a laser light device or a device that directly irradiates sunlight with optical glass, the optical device can have a longer life. Therefore, the exposure effect of the optical glass of the third embodiment is preferably 1.0%, more preferably 0.8%, and most preferably 0.5% as the upper limit.
In addition, the "exposure effect" in this specification means the deterioration amount of the spectral transmittance when the glass is irradiated with the ultraviolet-ray which has a strong peak wavelength of 365 nm. Specifically, it was determined by measuring the spectral transmittance before and after irradiation with light in accordance with the Japanese Optical Glass Industry Standard JOGIS04-2005 "Measurement Method for Exposure of Optical Glass". Here, the light is irradiated by heating the optical glass to 100 ° C., and irradiating the light of a 100 W ultra-high pressure mercury lamp having a strong peak wavelength of 365 nm with a wavelength of 30 mm from the optical glass for 3 hours.

The optical glass according to each embodiment of the present invention preferably has a high transmittance of visible light, particularly a short-wavelength side of visible light, so that it has less coloring.
In particular, if the optical glass of the present invention is expressed by the transmittance of glass, the shortest wavelength (λ ₈₀ ) showing a spectral transmittance of 80% from a sample with a thickness of 10 mm will be preferably 400 nm, more preferably 370 nm, and further preferably 350 nm. Is the upper limit.
In addition, in the optical glass of the present invention, the shortest wavelength (λ ₅ ) exhibiting a spectral transmittance of 5% by a sample having a thickness of 10 mm has an upper limit of preferably 360 nm, more preferably 340 nm, and further preferably 320 nm.
Thereby, the absorption end of the glass enters the ultraviolet region, and the transparency of the glass to visible light can be improved. Therefore, the optical glass can be preferably used for an optical device such as a lens that transmits light. In addition, in the optical glass of the first embodiment, in particular, the absorption of light incident on the glass is reduced, so that the heat generated by the energy of the incident light is reduced, so that damage due to thermal shock is less likely to occur.

The optical glass of the present invention preferably has a small specific gravity. More specifically, the specific gravity of the optical glass of the present invention is preferably 4.50 [g / cm ³ ] or less. As a result, the quality of optical devices using optical glass is reduced, so that a machine equipped with optical devices can be made lighter. In particular, in the first embodiment, by reducing the weight of the optical device and reducing the force exerted by the optical device on the holder or the like of the optical device, it is possible to further reduce the damage of the optical device. In addition, in the second embodiment, by reducing the weight of the optical device, the weight of the device provided with the optical device can be reduced. In particular, it is possible to reduce the shock caused when the device is dropped or the shake when the device is displaced (moved). The impact of stopping the displacement of the machine on the optical glass or its surrounding components. Therefore, the specific gravity of the optical glass of the present invention is preferably 4.50, more preferably 4.30, further preferably 4.00, and further preferably 3.80 as the upper limit. Furthermore, in many cases, the specific gravity of the optical glass of the present invention is approximately 2.00 or more, and more specifically, it is 2.20 or more.
The specific gravity of the optical glass of the present invention is measured based on the Japanese Optical Glass Industry Standard JOGIS05-1975 "Method for Measuring Specific Gravity of Optical Glass".

The optical glass of the present invention preferably has high devitrification resistance. As an index of the devitrification resistance, a low liquidus temperature can be mentioned. For example, the liquidus temperature of the optical glass of the present invention may be set to an upper limit of preferably 1300 ° C, more preferably 1200 ° C, and even more preferably 1100 ° C. Thereby, even if the molten glass flows out at a lower temperature, the crystallization of the produced glass is reduced, especially the devitrification when the glass is formed from the molten state, and the influence on the optical characteristics of the optical device using the glass can be reduced. . In addition, the glass can be formed even if the melting temperature of the glass is reduced. Therefore, by suppressing the energy consumed during the glass formation, the manufacturing cost of the glass can be reduced. On the other hand, the lower limit of the liquidus temperature of the optical glass of the present invention is not particularly limited, but the liquidus temperature of the glass obtained by the present invention can also be preferably 550 ° C, more preferably 600 ° C, and even more preferably 700. ℃ is set as the lower limit. In addition, the "liquid phase temperature" in the present specification refers to a platinum crucible with a capacity of 50 ml, and a 30cc cullet-shaped glass sample is put into a platinum crucible, and it is completely made at 1350 ° C. In the molten state, the temperature was lowered to a predetermined temperature and held for 12 hours. After being taken out of the furnace and cooled, the glass surface and the presence of crystals in the glass were immediately observed without confirming the lowest temperature of the crystals. Here, the predetermined temperature when the temperature is lowered is a temperature in units of 10 ° C from 550 ° C to 1300 ° C.

The optical glass of the present invention preferably has a glass transition point (Tg) of 630 ° C or lower. Thereby, the glass is softened at a lower temperature, so the glass can be pressed and formed at a lower temperature. In addition, it is possible to reduce the oxidation of the mold used for press forming and achieve a longer life of the mold. Therefore, the glass transition point of the optical glass of the present invention is preferably 630 ° C, more preferably 600 ° C, and even more preferably 570 ° C as the upper limit. Furthermore, the lower limit of the glass transition point of the optical glass of the present invention is not particularly limited, but the glass transition point of the optical glass of the present invention may be set to preferably 100 ° C, more preferably 200 ° C, and further preferably 300 ° C. Is the lower limit.

The optical glass of the present invention preferably has a yield point (At) below 700 ° C. The yield point is one of the indexes that indicate the softness of the glass in the same way as the glass transition point, and is an index that shows the temperature close to the press forming temperature. Therefore, by using a glass having a yield point of 700 ° C. or lower, press molding at a lower temperature can be performed, and thus press molding can be performed more easily. Therefore, the yield point of the optical glass of the present invention is preferably 700 ° C, more preferably 680 ° C, and most preferably 650 ° C as the upper limit. Furthermore, the yield point of the optical glass of the present invention may be set to a lower limit of preferably 150 ° C, more preferably 250 ° C, and even more preferably 350 ° C.

＜＜ Application of optical glass ＞＞
The glass molded body can be produced from the produced optical glass by, for example, a method of grinding processing or a method of mold press molding such as reheat press molding or precision press molding. That is, it is possible to produce a glass shaped body by mechanical processing such as grinding and grinding of optical glass, or to perform a reheat press molding on a preform made of optical glass, and then perform a grinding process to produce a glass shaped body, or The glass preform is produced by grinding a preform or a precision press forming of a preform formed by a known floating molding or the like. In addition, the method of manufacturing a glass forming body is not limited to these methods.

Thus, the glass molded body formed from the optical glass of the present invention is useful for various optical devices and optical designs.

≫Application of the optical glass of the first embodiment 实施
In particular, the optical glass of the first embodiment is preferably used for heating by irradiation of light, for example, it is preferably used for surveillance cameras, action cameras, laser projectors, headlights, or automotive cameras.

＜ Use of device with laser light source ＞
More specifically, the glass molded body formed of the optical glass of the first embodiment is preferably used for heating by light from a laser light source. Examples of such applications include laser projectors and headlights for transporters equipped with a laser light source.

[Use of laser projector]
Among them, as the laser projector, for example, a person having a light source device 1 as shown in FIG. 1 can be used. Here, the light source device 1 includes a light source 11 that emits laser light, a light-emitting wheel 14 disposed on the optical axis of the light source 11, and a wheel motor 13 that rotates and drives the light-emitting wheel 14. The light-emitting wheel 14 can be rotated by the wheel motor 13. It drives, and emits red, blue, and green light, for example, from the light-emitting wheel 14 (the laser light from the light source 11 is incident).

Here, it is preferable to arrange a collimating lens 12 on the emission side of the light source 11 and a focusing optical system composed of a plurality of lenses on the emission surface side of the light-emitting wheel 14 so that the light emitted from the light-emitting wheel 14 enters the guide光 装置 18。 Light device 18. The condensing optical system includes a condenser lens group 15 arranged near the light-emitting wheel 14, a condenser lens 16 arranged on the optical axis of the condenser lens group 15, and a condenser lens 16 arranged on the optical axis of the condenser lens 16 and A light guide device incident lens 17 near the incident surface of the light guide device 18 is configured.

As the light source 11, for example, a laser diode that emits a wavelength range of blue or ultraviolet light, that is, laser light of about 500 nm or less can be used, but is not limited thereto. The emitted light from the light source 11 is converted into parallel light by, for example, the collimating lens 12 and irradiates the light-emitting wheel 14 as laser light. Then, the light emitted from the light-emitting wheel 14 is condensed by, for example, a condenser lens group 15, and then is further condensed by the condenser lens 16 to be incident on the light guide device incident lens 17. The light beam incident on the incident lens 17 of the light guide device can also be irradiated on the incident surface of the light guide device 18 and incident into the light guide device 18. The light guide device 18 is adjusted to a light having a uniform intensity distribution, and is directed to the subsequent optical system. Projection can be projected to the projection-side block via the image generation block, for example.

Here, the image generation block may include a plurality of optical axis changing mirrors that change an optical axis direction of a light beam emitted from the light guide device 18, and a plurality of numbers that converge light reflected by the optical axis changing mirrors to the display device. Sheet condenser lenses and irradiation mirrors that irradiate light beams transmitted through these condenser lenses with a predetermined angle on a display device.

In addition, the projection-side block includes a lens group of a projection-side optical system that emits light formed by an image reflected by the display device toward a screen. More specifically, it may be a variable focus type lens unit having a fixed lens group built into a fixed lens barrel and a movable lens group built into a movable lens barrel, and having a zoom function.

However, with this type of laser projector, laser light such as blue laser light or ultraviolet laser light emitted from the light source 11 is irradiated to the optical glass constituting the optical system. For this reason, the optical glass is rapidly heated, and the thermal shock of the heating Causes damage to optical glass. In particular, the lens closest to the light source 11 (the collimating lens 12 shown in FIG. 1) is often rapidly heated by the laser light emitted from the light source 11.

Therefore, the optical glass of the first embodiment is used for an optical device such as a lens constituting an optical system of a laser projector, an optical device constituting the light source device 1 and a collimating lens 12 are even more preferable. When the optical device is subjected to thermal shock, it is not easy to cause damage due to thermal shock.

In addition, the overall structure of the laser projector system is more compact, and the heat generated by the laser light source is greater than that of the incandescent light. Therefore, the optical system or the device as a whole is easily heated, and the thermal shock caused by the heating at this time causes the optical Broken glass. Therefore, the optical glass according to the first embodiment is also preferably an optical device (for example, a lens or a mirror in an image generation block and a lens in a projection side block) that is far from the light source 11.

[Use of headlights for transport aircraft]
Examples of the headlight 2 for a transporter include a light source 22 for emitting laser light as shown in FIG. 2, a wavelength conversion element 23 disposed on the optical axis of the light source 22, and a cover provided to cover these parts. There are 28 members. In the headlight 2 for a transporter, light having a desired color temperature (including light obtained by superimposing a plurality of monochromatic lights), such as white, can be emitted from the wavelength conversion element 23 (the laser light from the light source 22 is incident).

As the light source 22, for example, a laser diode that emits a wavelength range of blue or ultraviolet light, that is, laser light of about 500 nm or less can be used, but is not limited thereto. The light emitted from the light source 22 is condensed in the direction of the wavelength conversion element 23 using a condenser lens 27 as needed, and is irradiated to the wavelength conversion element 23 as laser light.

In addition, for the emitted light from the wavelength conversion element 23, a reflector 24 can be used as needed to convert the direction of the light path from the emitted light direction D2 to the main radiation direction D1 of the headlight 2 for the transporter, and to generate the head for the transporter After the required light image of the lamp 2 is obtained, light is picked up from a transparent cover member 28 provided arbitrarily. Here, the light guide element 29 may be provided immediately before the wavelength conversion element 23 or in a manner that the wavelength conversion element 23 is fixed, thereby guiding light from the light source 22 to the wavelength conversion element 23. In addition, in order to absorb the reflected light generated when the light from the light source 22 is irradiated to the wavelength conversion element 23 or the light guide element 29, a shielding element 25 may be provided on the light path of the reflected light. In addition, a heat sink 26 may be provided as a carrier element for fixing the wavelength conversion element 23 in the reflector 24.

However, for such a headlight 2 for a transporter, blue laser light or ultraviolet laser light emitted from the light source 22 is irradiated to an optical system such as a condenser lens 27 or an optical glass constituting a cover member 28, and this optical glass is used for this purpose. It is rapidly heated, and the thermal shock caused by the heating causes breakage of the optical glass. In particular, the lens closest to the light source 22 (the condenser lens 27 shown in FIG. 2) is often heated by the laser light emitted from the light source 22.

Therefore, by using the optical glass of the first embodiment as an optical device such as a lens constituting the optical system of the headlight 2 for a transporter, it is more preferable to use a condenser lens 27 provided between the light source 22 and the wavelength conversion element 23, even if When these optical devices are subjected to thermal shock, it is also difficult to cause damage due to thermal shock.

＜ Use of the device exposed to direct sunlight ＞
More specifically, the glass molded body formed of the optical glass of the first embodiment is also preferably used for heating by direct sunlight. Examples of such applications include cameras for automobiles and headlights for transporters.

[Use of car camera]
Among them, a car camera is a camera mounted on the outside of a car body, and includes a camera lens (imaging lens) 31 as shown in FIG. 3, and an imaging device (for imaging an image formed by the imaging lens 31) ( CCD) 32 optical system. Among them, the imaging lens 31 is constituted by an optical device such as a plurality of lenses, and a light beam from a subject is incident on the first lens 31a which is an object point (subject) side. The light beam incident from the first lens 31 a is sequentially incident on the lenses subsequent to the second lens, and is formed as an image of a subject on the imaging surface of the imaging device 32.

Examples of the car camera include those mounted on the rear side of the vehicle body to check the rear, or mounted on the front side of the vehicle body to check the front or side, and the distance from the vehicle in front.

However, such a car camera may be heated rapidly by direct sunlight and the temperature of the vehicle body may reach 60 ° C or higher. In addition, it may be rapidly cooled by rain or water from a car wash, which may cause thermal shock. In particular, the first lens 31a is often rapidly cooled by rain or water from a car wash.

Therefore, by using the optical glass of the first embodiment for the imaging lens 31 used in an automobile camera, it is more preferable to use the first lens 31a on the subject (object point) side, even if these imaging lenses 31 are subjected to thermal shock. In this case, damage caused by thermal shock is not easy to occur.

In addition, as a lens for an automobile camera, at least one of a plurality of lenses may have an aspheric surface. This can reduce the phase difference caused by the lens, improve the resolution, etc., thereby achieving the improvement of the optical characteristics.

[Use of headlights for transport aircraft]
On the other hand, in the use of headlights for transporters as described above, the use is similar to the use of automotive cameras. Sometimes, if it is exposed to direct sunlight, it may be heated rapidly and the temperature of the vehicle body may reach 60 ° C or more. The water was rapidly cooled, for which it was subjected to thermal shock.

Therefore, by using the optical glass of the first embodiment in an optical element such as a cover member 28 or a condenser lens 27 in the headlight 2 for a transporter as shown in FIG. In the case of cooling and receiving thermal shock, damage caused by thermal shock is not easy to occur.

≫Application of optical glass in the second embodiment 实施
The optical glass of the second embodiment is preferably used for an optical device in an outdoor optical device or an optical device in an optical device having a displacement means.

＜ Application of optical devices in outdoor optical equipment ＞
Among them, the use of optical devices in outdoor optical equipment includes surveillance cameras, action cameras, automotive cameras, and headlights for transporters. In these applications, in most cases, strong winds or flying objects cause mechanical shock to optical devices. By using the optical glass of the second embodiment for these applications, even if the optical device is not covered with a cover or an elastomer, damage to the optical device due to strong wind or flying objects generated thereby can be reduced.

[Use of surveillance camera]
Among them, the surveillance camera 4 can be set as shown in FIG. 4, for example, and has a camera device body 41, a photographing lens barrel 42 mounted on the camera device body 41, and a camera lens body 42 for mounting the photographing lens barrel 42 on the camera device body 41. 43 were installed.

As shown in FIG. 4, the camera device body 41 is provided with a frame 44 provided with an entrance window 44 a through which light guided from the photographic lens barrel 42 enters, and a frame 44 housed inside the frame 44 and having an imaging device (CCD) 45. Substrate 46. Other than that, illustration is omitted, but a control unit, a power supply unit, and the like are provided inside the housing 44. The imaging device 45 is disposed inside the housing 44 such that the optical axis C of the imaging lens barrel 42 mounted on the entrance window 44a side and the imaging center O of the imaging surface are substantially the same.

The photographing lens barrel 42 includes one or more photographing lenses, and a light beam from a subject is incident from the object point (subject) side. The light beam incident from the imaging lens barrel 42 is imaged on the imaging surface of the imaging device 45 as an image of a subject.

The photographing lens barrel 42 is constituted by a required optical system, and guides light incident from the object point (subject) side to the imaging device 45 of the camera device body 41, and causes the light to be captured by the imaging device 45. Surface imaging. The outer peripheral surface of the camera device body 41 side of the photographic lens barrel 42 is provided with a male screw portion 42 a screwed to a holder portion 432 described later. When the photographic lens barrel 42 is attached to the camera device body 41, the photographic lens barrel 42 is fixed to the holder portion 432.

The mounting portion 43 includes a base portion 431, a holder portion 432, a washer 433, and a stopper portion 434 that are sequentially disposed from the side of the camera device body 41 toward the side of the imaging lens barrel 42. Since the mounting portion 43 guides the light incident from the imaging lens barrel 42 to the side of the camera device body 41, the mounting portion 43 has a cylindrical shape.

The base 431 is formed by a cylindrical member having the photographic center O of the imaging device 45 provided in the camera device body 41 as a central axis, and is integrally formed with the camera device body 41 on the lens mounting side of the camera device body 41.

The holder portion 432 is a cylindrical member having an internally threaded portion 432a on the inner peripheral surface, and the externally threaded portion 42a of the photographic lens barrel 42 is screwed to the internally threaded portion 432a.

The washer (gasket) 433 is composed of a hollow disc member, and is sandwiched between a stopper portion 434 and a holder portion 432 described later when the photographic lens barrel 42 is mounted.

The stopper portion 434 is a member that fixes the holder portion 432 to the base portion 431, and a washer (gasket) 433 is held between the stopper portion 434 and the holder portion 432 or the base portion 431 and fixes these. In addition, since the photographing lens barrel 42 can be fixed to the holder portion 432, the photographing lens barrel 42 can be fixed to the camera device body 41 by fixing the holder portion 432 to the base portion 431 using the stopper portion 434.

This surveillance camera 4 is mainly used for theft prevention in shops, banks, roads, and parking lots. However, as long as the photographing lens barrel 42 of the surveillance camera 4 provided outdoors is not provided with a cover or the like on the surface of the photographing lens barrel 42, the photographing lens lens is often caused by strong wind or flying objects generated thereby. The optical glass of the barrel 42 is broken.

Therefore, by using the optical glass of the second embodiment as the lens closest to the subject (object point) of the lenses constituting the photographic lens barrel 42 used in the surveillance camera 4, it is difficult to generate strong wind or flying. Damage to the photographic lens barrel 42 caused by the object.

[Use of action camera]
In addition, sports cameras are also called wearable cameras due to the characteristics of the sports cameras, and are attached to a helmet worn on the user's body via a hood strap, or at least partially floated or driven by a propeller or a motor. A mobile drone or a drone is installed with a camera, and shooting is performed, so that the shooting can be performed at an angle or condition that was not possible with previous cameras. As the moving camera, for example, as shown in FIG. 3, an optical system having an imaging lens 31 and an imaging device 32 for imaging an image formed by the imaging lenses 31 can be used. The imaging lens 31 is composed of an optical device such as a plurality of lenses, and a light beam from a subject is incident from a first lens 31a that is an object point (subject) side. The light beam incident from the first lens 31 a is sequentially incident on the lenses subsequent to the second lens, and is formed as an image of a subject on the imaging surface of the imaging device 32.

Especially when the optical system shown in FIG. 3 is used for a motion camera, from the viewpoint of mitigating the impact applied to the optical system, rubber may be provided between the imaging lens 31 and a lens barrel (not shown). And other elastic material.

However, most of such action cameras are used outdoors. As long as the camera lens 31 of the action camera is not provided with a cover or the like on the surface of the camera lens 31, in most cases, flying objects caused by strong winds cause optical glass. damaged. In addition, the first lens 31a is particularly prone to damage due to strong wind or flying objects.

Therefore, by using the optical glass of the second embodiment for the imaging lens 31 used in a motion camera, and more preferably the first lens 31a on the object (object point) side, it is difficult to generate the reason for these imaging lenses 31 Damage caused by strong wind or flying objects.

[Use of car camera]
In addition, the automobile camera is a camera mounted on the outside of the body of the automobile, and, similarly to the first embodiment, includes an imaging lens 31 having an imaging lens 31 as shown in FIG. Optical system of the device (CCD) 32.

The imaging lens 31 in such an automobile camera is also damaged by strong winds or flying objects caused by the strong wind unless the cover or the like is provided on the surface of the imaging lens 31. In particular, the first lens 31a is liable to be damaged due to strong wind or flying objects.

Therefore, by using the optical glass of the second embodiment for the imaging lens 31 used in an automobile camera, and more preferably the first lens 31a on the subject (object point) side, it is difficult to generate the reason among these imaging lenses 31 Damage caused by strong wind or flying objects.

[Use of headlights for transport aircraft]
In addition, as the headlight 2 for a transporter, as in the first embodiment, for example, a light source 22 having laser light emitted as shown in FIG. 2, a wavelength conversion element 23 disposed on the optical axis of the light source 22, and A cover member 28 is provided so as to cover these portions.

For such a headlight 2 for a transporter, strong winds or flying objects hitting the outer-facing optical glass of the transporter, more specifically the optical glass constituting the cover member 28, cause damage to the optical glass.

Therefore, by using the optical glass of the second embodiment in an optical element such as a cover member 28 in the headlight 2 for a transporter as shown in FIG. 2, it is possible to reduce the amount of damage caused by strong wind or flying objects caused by the wind. The cover member 28 is damaged or the entire headlight 2 for a transporter is damaged.

＜ Application of optical devices in machines with displacement means ＞
Examples of the use of a device having a displacement means include a motion camera, a car camera, and a headlight for a transporter. In these applications, in most cases, when the machine is displaced by a displacement means or when the machine is braked, a mechanical shock is caused to the optical device. By using the optical glass of the second embodiment for these applications, it is possible to reduce damage to the optical device during machine displacement or braking.

[Use of action camera]
Among them, in the application of the action camera, when the action camera is mounted on a machine having a displacement means, the shock caused by the displacement means or the fall of the machine, or the shake when the machine is displaced (moved) by the displacement means. Or, the reaction effect when the displacement of the machine caused by the displacement means is stopped, so the optical device is liable to be damaged.

Therefore, by using the optical glass of the second embodiment in each optical element constituting the imaging lens 31 in the optical system shown in FIG. 3, for example, it is not easy to cause shaking when the moving camera is displaced, or stop the moving camera. Damage to optics caused by reaction during displacement.

[Use of car camera]
In addition, the optical device fixed to a transporter, such as a car camera or a headlight for a transporter, is used in the same way as an action camera, because the driver is shaken when the driver is driven or the transporter is stopped to react, so the optical device Easily damaged.

Among them, with regard to the use of an automobile camera, for example, each optical element constituting the imaging lens 31 in the optical system shown in FIG. 3 is less likely to cause a shake when the conveyor is driven or a reaction when the conveyor is stopped. Damage to optics.

[Use of headlights for transport aircraft]
In addition, with regard to the use of the headlight for a transporter, for example, by using the optical element such as the condenser lens 27 or the cover member 28 in the headlight 2 for a transporter as shown in FIG. Or damage to the optics caused by a reaction when the transporter is stopped.

≫Application of optical glass in the third embodiment≫
The optical glass of the third embodiment is preferably used for an optical device that transmits laser light or an optical device that is irradiated with direct sunlight.

＜ Application of optical device for transmitting laser light ＞
Among them, as applications of optical devices that transmit laser light, laser projectors or headlights for laser light transporters, laser devices, laser oscillators, and laser processing machines can be cited.

[Use of laser projector]
Among them, as the laser projector, the same one as in the first embodiment can be used, for example, the light source device 1 shown in FIG. 1 is provided.

In such a laser projector, laser light such as blue laser light or ultraviolet laser light emitted from the light source 11 is irradiated to the optical glass constituting the optical system, and for this reason, the transmittance of the optical glass is gradually reduced. In particular, the lens closest to the light source 11 (the collimating lens 12 shown in FIG. 1) is liable to reduce transmittance due to the laser light emitted from the light source 11.

Therefore, the optical glass of the third embodiment is used for optical devices such as lenses constituting an optical system of a laser projector, more preferably an optical device constituting the light source device 1, and even more preferably a collimating lens 12. Over time, these optical devices have reduced transmittance.

[Use of headlights for transport aircraft]
In addition, as the headlight 2 for a transporter, as in the first embodiment, for example, a light source 22 having laser light emitted as shown in FIG. 2, a wavelength conversion element 23 disposed on the optical axis of the light source 22, and A cover member 28 is provided so as to cover these portions.

For such a headlight 2 for a transporter, the blue laser light or ultraviolet laser light emitted from the light source 22 is irradiated to the optical system such as the condenser lens 27 or the optical glass constituting the cover member 28, and this is the transmission of the optical glass The rate gradually decreases. In particular, the lens closest to the light source 22 (condensing lens 27 shown in FIG. 2) is liable to decrease in transmittance due to laser light emitted from the light source 22.

Therefore, by using the optical glass of the third embodiment as an optical device such as a lens constituting the optical system of the headlight 2 for a transporter, it is more preferable to use a condenser lens 27 provided between the light source 22 and the wavelength conversion element 23, A reduction in transmittance with time in these optical devices is unlikely to occur.

[Use of laser device]
Examples of the laser device include a laser light emitting device 5 that emits laser light when a current is supplied from two pins 54 as shown in FIG. 5. For example, a laser light source including an unillustrated laser light source and a light source as shown in FIG. 5 can be used. The tube holder 51, cover 52, glass 53 and pin 54 are shown. Here, the glass 53 may be a cover glass or a lens.

The socket 51 is, for example, a plate-shaped member made of metal, and is used for positioning the laser light emitting device 5. The cover 52 is a member that houses the laser light source, and is, for example, a member made of metal, and is fixed to the main surface of the stem 51. An opening provided on the upper surface of the cover 52 is provided with a light-transmitting glass 53 and is configured to extract light from the laser light source from the glass 53.

Pin 54 is a pin for supplying current to the laser light source, and is provided with two pins. The pin 54 penetrates the socket 51 and is electrically connected to the laser light source.

However, for such a laser light emitting device 5, light from a laser light source is irradiated to the glass 53, and for this reason, the transmittance of the glass 53 is gradually reduced.

Therefore, when the optical glass of the third embodiment is used for the glass 53 of the laser light emitting device 5, it is difficult to cause a decrease in the transmittance with time in the glass 53.

[Use of laser oscillator]
Examples of the laser oscillator include laser oscillator 6 that oscillates laser light L1 with excitation light L0. For example, as shown in FIG. 6, an excitation light source 61, a collimator lens 63, a condenser lens 64, and the like can be used. The end mirror 65, the laser medium 66, and the output mirror 67. Here, the end mirror 65 and the output mirror 67 constitute a laser resonator. Furthermore, the laser oscillator 6 may be provided with a means for adjusting or changing the energy of the oscillating laser, such as a Q switch or a shutter.

Here, the excitation light source 61 generates and emits excitation light L0, and is composed of a laser diode or the like. The type of the excitation light source 61 is selected according to the required laser light and the type of the laser medium 66.

The excitation light L0 emitted from the excitation light source 61 is transmitted through the transmission optical fiber 62 as necessary, and is incident on the collimator lens 63 to be adjusted to a parallel light beam. The excitation light L0 that is a parallel light beam is condensed using a condenser lens 64 and irradiates a laser medium 66 disposed at a focal point of the condenser lens 64. Thereby, the laser light L1 is induced to be emitted by the excitation light L0.

The laser light L1 induced from the laser medium 66 is enclosed in a laser resonator composed of an end mirror 65 and an output mirror 67. Here, the end mirror 65 is a mirror that transmits the wavelength of the excitation light L0 and reflects the wavelength of the laser light L1 with a high reflectance. The output mirror 67 is a mirror having a predetermined transmittance with respect to the wavelength of the laser light L1. With the end mirror 65 and the output mirror 67, the laser light L1 travels back and forth between the end mirror 65 and the output mirror 67, and a part of the laser light L1 incident on the output mirror 67 is output. Furthermore, as an output from the output mirror 67, the laser light L1 which is a standing wave of a specific resonance frequency can be captured.

However, with this laser oscillator 6, the excitation light L0 or the laser light L1 is irradiated to the optical glass constituting the optical system, and for this reason, the transmittance of the optical glass is gradually reduced. In particular, the transmittance of the collimator lens 63 or the condenser lens 64, the end mirror 65, or the output mirror 67 is likely to decrease due to the continuous incidence of the excitation light L0 or the laser light L1.

Therefore, the optical glass of the third embodiment is used for an optical device such as a lens constituting an optical system of the laser oscillator 6, and is more specifically used for a collimating lens 63 or a condenser lens 64, an end lens 65, or The output mirror 67 does not easily cause a decrease in transmittance with time in these optical devices.

[Use of laser processing machine]
Examples of the laser processing machine include a laser processing machine 7 that performs processing such as cutting while moving the object W to be processed. For example, as shown in FIG. 7, a laser oscillator 71 and a collimator lens can be used. 73 and the condenser lens 76. In addition, the laser processing machine 7 may be provided with a transmission fiber 72 for transmitting the laser light L oscillated by the laser oscillator 71, or a mirror 74 and a mirror 75 for changing the traveling direction of the laser light L.

Here, the laser light L oscillated by the laser oscillator 71 is not particularly limited as long as it can process the object to be processed W when it is focused. The internal configuration of the laser oscillator 71 may be the same as that of the laser oscillator 6 described above.

The laser light L oscillated by the laser oscillator 71 is transmitted through the transmission optical fiber 72 as necessary, and is incident on the collimator lens 73 to be adjusted to a parallel light beam. The laser light L, which becomes a parallel light beam, is changed in the traveling direction using a reflecting mirror 74 and a reflecting mirror 75 as necessary, and is incident on a condenser lens 76. The laser light L incident on the condenser lens 76 is condensed by the condenser lens 76 and irradiates the processing object W disposed at the focal point of the condenser lens 76 to process the processing object W near the focal point.

However, in such a laser processing machine 7, the laser light emitted from the laser oscillator 71 is irradiated to the optical glass constituting the optical system, and for this reason, the transmittance of the optical glass is gradually reduced. In particular, a lens close to the laser oscillator 71 (the collimator lens 73 shown in FIG. 7) is liable to decrease in transmittance due to the continuous incidence of the laser light L from the laser oscillator 71.

Therefore, by using the optical glass of the third embodiment as an optical device such as a lens constituting the optical system of the laser processing machine 7, and more preferably a collimating lens 73 of the laser processing machine 7, it is not easy to produce these optical devices. The transmittance decreases with time.

＜ Application of optical devices exposed to direct sunlight ＞
Examples of applications of optical devices that are irradiated with direct sunlight include cameras for automobiles and headlights for transporters.

[Use of car camera]
Among them, the automobile camera is a camera mounted on the outside of the body of a car, and as in the first embodiment, it is provided with a lens (imaging lens) 31 for an automobile camera as shown in FIG. An optical system of an imaging device (CCD) 32 that performs imaging.

In most cases, the imaging lens 31 in such an automobile camera is continuously exposed to direct sunlight, and for this reason, the light transmittance gradually decreases. In particular, the first lens 31a has a large influence on a decrease in light transmittance due to direct sunlight.

Therefore, by using the optical glass of the third embodiment for the imaging lens 31 used in an automobile camera, and more preferably the first lens 31a on the subject (object point) side, it is not easy to generate the experience in these imaging lenses 31. The transmittance decreases with time.

[Use of headlights for transport aircraft]
On the other hand, in the applications of the headlights for transporters as described above, as in the applications of automobile cameras, in most cases, they are continuously irradiated with direct sunlight. For this reason, the light transmittance of optical devices is gradually reduced.

Therefore, by using the optical glass of the third embodiment in an optical element such as a cover member 28 or a condenser lens 27 in the headlight 2 for a transporter as shown in FIG. 2, it is not easy to generate time in these optical elements. The transmittance decreases.

[Example]
The composition of the examples (No.A1 to No.A12, No.B1 to No.B13, No.C1 to No.C10) and comparative examples (No.a to No.e) of the present invention and the refraction of these glasses Ratio (n _d ), Abbe number (ν _d ), product of average linear expansion coefficient α and Young's modulus E, and the spectral transmittance shows wavelengths of 5% and 80% (λ ₅ and λ ₈₀ ), specific gravity, glass Tables 1 to 6 show the transition points, yield points, ball drop test results, and results of exposure. The examples (No. A1 to No. A12) are examples of the first embodiment. The examples (No. B1 to No. B13) are examples of the second embodiment. Examples (No. C1 to No. C10) are examples of the third embodiment. In addition, the following examples are only for the purpose of illustration, and are not limited to these examples.

The glasses of the examples and comparative examples of the present invention are used as raw materials for each component, and the corresponding oxides, hydroxides, carbonates, nitrates, fluorides, hydroxides, metaphosphoric acid compounds, etc. are selected for general use. The high-purity raw materials of optical glass are weighed and uniformly mixed to form the composition ratios of the respective examples shown in the table, and then put into a platinum crucible. Depending on the ease of melting of the glass composition, use an electric furnace at 1200 ° C to 1500 ° C. After melting at a temperature range of 2 hours to 4 hours, it is homogenized by stirring, and then cast into a mold or the like, and then slowly cooled to produce glass.

The refractive index (n _d ) and Abbe number (ν _d ) of the glass of the examples and comparative examples are expressed by the measured values of the d-ray (587.56 nm) of the helium lamp. Further, Abbe number (v _d) using the d-line refractive index of the rays, the refractive index _(n-F) of F-ray hydrogen lamp (486.13 nm), the refractive index of the C-ray (656.27 nm) of the _(n-C) The value is calculated from the equation of Abbe number (ν _d ) = [(n _d -1) / (n _F -n _C )].

In addition, the transmittances of the glasses of the examples and comparative examples were measured in accordance with the standards of the Japan Optical Glass Industry Association JOGIS02. In addition, in the present invention, by measuring the transmittance of the glass, the presence or absence of the coloration of the glass is determined. Specifically, for a parallel polished product with a thickness of 10 ± 0.1 mm, the spectral transmittance of 200 nm to 800 nm was measured according to JISZ8722, and λ ₅ (wavelength at 5% transmittance) and λ ₇₀ (wavelength at 70% transmittance) were obtained. ).

In addition, the specific gravity of the glass of an Example and a comparative example was measured based on the Japan Optical Glass Industry Association standard JOGIS05-1975 "The measuring method of the specific gravity of an optical glass."

In addition, the glass transition point (Tg) and yield point (At) of the glass of the examples and comparative examples were obtained from the thermal expansion curve. The thermal expansion curve is based on the Japan Optical Glass Industry Standard JOGIS08-2003 "The "Method of measuring thermal expansion" is obtained by measuring the relationship between the temperature and the elongation of the sample.

In addition, the liquidus temperature of the glass of the examples and comparative examples was measured by placing the pulverized glass samples on a platinum plate at 10 mm intervals, and placing the platinum plate at a temperature of 800 ° C to 1200 ° C. After holding in a furnace with a temperature gradient for 30 minutes, it was taken out. After cooling, the presence or absence of crystals in the glass sample was observed using a microscope with a magnification of 80 times. At this time, the optical glass was pulverized to a granular shape having a diameter of about 2 mm as a sample.

In addition, the average linear expansion coefficient (α) of the glass of the examples and comparative examples is based on the Japanese Optical Glass Industry Standard JOGIS08-2003 "Measurement Method of Thermal Expansion of Optical Glass", and the average line of -30 ° C to + 70 ° C is obtained. Coefficient of expansion. In addition, the Young's modulus (E) of the glasses of Examples and Comparative Examples was measured by an ultrasonic method, and the product of the average linear expansion coefficient (α) and the Young's modulus (E) was determined.

In addition, as a result of the falling ball test of the glass of the Examples and Comparative Examples, a 23.8 g (approximately 1.8 cm in diameter) steel ball made of SUJ-2 was dropped freely to a width of 50 mm × 50 mm or more and a thickness of 5 mm. When the center of the main surface of an optical double-sided polished optical glass having a diameter of 30 mm × thickness of 2 mm was left on the main surface of a rubber sheet made of natural rubber, at least a part of the optical glass was found to be cracked, damaged, or cracked. The minimum height [cm] of breakage.

In addition, the exposure effects of the glass of the examples and comparative examples were determined by measuring the spectral transmittances before and after irradiation according to the standard of the Japanese Optical Glass Industry Association JOGIS04-2005 "Measurement Method of Exposure of Optical Glass". Here, the light is irradiated by heating the optical glass to 100 ° C. while irradiating the light of a 100 W ultra-high pressure mercury lamp with a strong peak at a wavelength of 365 nm from a distance of 30 mm from the optical glass for 3 hours.

[Table 1]

[Table 2]

[table 3]

[Table 4]

[table 5]

[TABLE 6]

As shown in the table, all the optical glasses of the embodiments of the present invention are in the range of refractive index (n _d ) of 1.47 to 1.54 and Abbe number (ν _d ) of 60 to 68, which are in the required range.

In addition, the optical glass systems λ ₈₀ (wavelength at 80% transmittance) of the examples of the present invention are all 400 nm or less, and more specifically 350 nm or less. In addition, the optical glass systems λ ₅ (wavelength at 5% transmittance) of the examples of the present invention are all 360 nm or less, and more specifically 320 nm or less.

In addition, the specific gravity of the optical glass of the examples of the present invention is 4.50 or less, and more specifically 3.70 or less, which are within a required range.

In addition, the optical glass of the embodiment of the present invention is not devitrified and is a stable glass.

Therefore, it is shown that the refractive index (n _d ) and Abbe number (ν _d ) of the optical glass system of the embodiment of the present invention are within the required ranges.

In addition, it is also shown that the optical glass of the embodiment of the present invention has less coloration and a smaller specific gravity.

In particular, the product (α × E) of the average linear expansion coefficient (α) and the Young's modulus (E) of the optical glass system of the examples (No. A1 to No. A12) is 60,000 or less, and more specifically 57,000 or less. On the other hand, the product (α × E) of the glass-based average linear expansion coefficient (α) and the Young's modulus (E) of the comparative example (No.a) exceeds 60,000.

Therefore, it is shown that the refractive index (n _d ) and Abbe number (ν _d ) of the optical glass system of the examples (No. A1 to No. A12) are within the required ranges, and the average linear expansion coefficient (α) and the Young's mode The product (α × E) of the number (E) is small. For this reason, the optical glass of the examples (No. A1 to No. A12) is resistant to rapid temperature changes, so it can also be used for applications that are less prone to damage due to thermal shock.

In addition, the optical glasses of the examples (No. A1 to No. A12) all have an average linear expansion coefficient (α) at -30 ° C to + 70 ° C of 100 × 10 ^-7 K ^-1 or less, and more specifically 70 × 10 ^-7 K ^-1 or less, within the required range.

On the other hand, the results of the optical glass-based falling ball test of Examples (No. B1 to No. B13) were 100 cm or more, and more specifically, 110 cm or more. On the other hand, the result of the glass-based drop ball test of Comparative Example (No. A) was less than 100 cm.

Therefore, it is shown that the refractive index (n _d ) and Abbe number (ν _d ) of the optical glass system of the examples (No. B1 to No. B13) are within the required ranges, and the ball drop test results are excellent, and the glass is not easily caused by the ball drop test And rupture. For this reason, it is presumed that the optical glass systems of Examples (No. B1 to No. B13) have high impact resistance.

On the other hand, the optical glass-based exposure effect of Examples (No. C1 to No. C10) was 1.0% or less, and more specifically, 0.7% or less. On the other hand, the glass-based exposure effect of Comparative Examples (No. A to No. C) exceeded 1.0%.

Therefore, it is shown that the refractive index (n _d ) and Abbe number (ν _d ) of the optical glass system in the embodiment of the present invention are within the required ranges, and the exposure effect is small. For this reason, it is speculated that the optical glass system of the embodiment of the present invention is unlikely to cause degradation of the spectral transmittance due to the passage of time.

In addition, all the optical glasses of the examples (No. B1 to No. B13, No. C1 to No. C10) have glass transition points of 600 ° C. or lower, more specifically, 560 ° C. or lower, which are within a required range.

In addition, the optical glasses of the examples (No. B1 to No. B13, No. C1 to No. C10) all have a yield point of 700 ° C. or lower, and more specifically, 630 ° C. or lower, which are within a required range.

Therefore, it was also shown that the optical glasses of the examples (No. B1 to No. B13, No. C1 to No. C10) are easily press-formed.

In the above, the present invention has been described in detail for the purpose of illustration. However, this embodiment is only for the purpose of illustration. It should be understood that a variety of changes can be made by the industry without departing from the spirit and scope of the present invention.

1‧‧‧light source device

2‧‧‧ headlights for transport aircraft

5‧‧‧laser light emitting device

6.71‧‧‧laser oscillator

11, 22‧‧‧ light source

12, 63, 73‧‧‧‧ Collimating lens

13‧‧‧ wheel motor

14‧‧‧light wheel

15‧‧‧ condenser lens group

16, 27, 64, 76‧‧‧ condenser lens

17‧‧‧ light guide device incident lens

18‧‧‧ light guide

23‧‧‧Wavelength Conversion Element

24‧‧‧ reflector

25‧‧‧shielding element

26‧‧‧ heat sink

28‧‧‧ cover member

29‧‧‧light guide

31‧‧‧camera lens

31a‧‧‧1st lens

32, 45‧‧‧ camera devices

41‧‧‧ Camera Unit

42‧‧‧Photographic lens barrel

42a‧‧‧External thread

43‧‧‧Mounting Department

44‧‧‧Frame

44a‧‧‧incident window

46‧‧‧ substrate

51‧‧‧tube socket

52‧‧‧ Cover

53‧‧‧ Glass

54‧‧‧pin

61‧‧‧Excitation light source

62‧‧‧Transmission Fiber

65‧‧‧ end mirror

66‧‧‧laser medium

67‧‧‧output mirror

74, 75‧‧‧ mirror

431‧‧‧base

432‧‧‧ Holder Department

432a‧‧‧ Internal thread

433‧‧‧washer

434‧‧‧ Stopper Division

D1‧‧‧ main radiation direction

D2‧‧‧ radiation direction

L, L1‧‧‧‧ laser light

L0‧‧‧Excitation light

W‧‧‧ Processing object

FIG. 1 is a schematic cross-sectional view showing the structure of an optical system of a laser projector to which the optical glass of the present invention can be preferably used.

Fig. 2 is a schematic cross-sectional view showing a structure of a headlight for a transporter in which the optical glass of the present invention can be preferably used.

FIG. 3 is a schematic cross-sectional view showing a structure of an optical system of a sports camera and an automobile camera to which the optical glass of the present invention can be preferably used.

FIG. 4 is a cross-sectional view of a main part showing the structure of a surveillance camera to which the optical glass of the present invention can be preferably used.

FIG. 5 is a schematic cross-sectional view showing the structure of an optical system of a laser device in which the optical glass of the present invention can be preferably used.

FIG. 6 is a schematic cross-sectional view showing the structure of an optical system of a laser oscillator in which the optical glass of the present invention can be preferably used.

FIG. 7 is a schematic cross-sectional view showing the structure of an optical system of a laser processing machine in which the optical glass of the present invention can be preferably used.

Claims (10)

An optical glass, based on the mass% of the oxide basis, the SiO ₂ component is 30.0% to 80.0%; the B ₂ O ₃ component is 1.0% to 30.0%; and the Rn ₂ O component (where Rn is Li, Na, At least any one of K) is 1.0% to 30.0%; and has an optical constant in the range of refractive index (n _d ) of 1.47 to 1.54 and Abbe number (ν _d ) of 60 to 68. The optical glass according to claim 1, which is the average linear expansion coefficient α [× 10 ^-7 / ° C] and Young's modulus E [× 10 ⁸ N / m ² ] at -30 ° C to + 70 ° C. The product α × E is 60,000 or less. The optical glass according to claim 2 is an optical device used for heating by irradiation of light. The optical glass according to claim 2 or 3 is used for surveillance cameras, action cameras, laser projectors, headlights, or automotive cameras. The optical glass according to claim 1, wherein when the 23.8 g steel ball is freely dropped onto the optical glass, the minimum height of the optical glass breakage is 100 cm or more. The optical glass according to claim 5 is an optical device for outdoor use or an optical device with a displacement means. The optical glass according to claim 5 or 6 is used for surveillance cameras, action cameras, car cameras or headlights. According to the optical glass described in claim 1, the degradation amount when measuring the spectral transmittance of light before and after irradiation according to the standard of Japan Optical Glass Industry Association JOGIS04-2005 "Measurement method of exposure of optical glass" is 1% or less. The optical glass according to claim 8 is an optical device for incident laser light or direct sunlight. The optical glass according to claim 8 or 9 is used for a laser projector, a laser processing machine, a laser device, a laser oscillator, or a headlight.