CN109592898A - Optical glass, preform and optical element - Google Patents

Abstract

Problem of the present invention is that obtaining a kind of optical glass, preform and optical element, the refractive index (n of the optical glass_d) and Abbe number (ν_d) in the range of expected, and partial dispersion ratio (θ g, F) is smaller.The optical glass contains SiO in terms of quality %₂Ingredient 20.0~45.0%, Nb₂O₅Ingredient 25.0~60.0%, TiO₂Ingredient 0~5.0%, mass ratio (Li₂O/Na₂O+K₂O) between 0.40~1.00, partial dispersion ratio (θ g, F) and Abbe number (ν_d) between meet (- 0.00162 × ν_d+ 0.620)≤(θ g, F)≤(- 0.00162 × ν_d+ 0.657) relationship, the temperature coefficient (40~60 DEG C) of relative index of refraction (589.29nm) is +6.0 × 10^‑6~-5.0 × 10^‑6(℃^‑1) in the range of.

Description

Optical glass, preform and optical element

Technical field

The present invention relates to a kind of optical glass and optical elements.

Background technique

The optical systems such as digital camera or video camera, more or less containing the bleeding for being referred to as aberration.The aberration quilt It is categorized into monochromatic aberration and chromatic aberation, especially chromatic aberation, largely depends on lens used in optical system Material property.

In general, combined by the convex lens of low dispersion and the concavees lens of high dispersion come correcting chromatic aberration, but this group The aberration for being merely able to correction red area and green area is closed, the aberration of blue region still has.This not can be removed completely Blue region aberration be referred to as second order spectrum.When being corrected to second order spectrum, need to account for the g line of blue region The optical design of (435.835nm) trend.At this point, using part color as the optical characteristics index gazed in optical design It dissipates than (θ g, F).In optical system made of the lens of above-mentioned low dispersion and the lens combination of high dispersion, pass through low dispersion side Lens use partial dispersion ratio (θ g, F) biggish optical material, the lens of high dispersion side use partial dispersion ratio (θ g, F) Lesser optical material, being capable of good correction second order spectrum.

Partial dispersion ratio (θ g, F) is such as shown in following formula (1).

θ g, F=(n_g-n_F)/(n_F-n_C)……(1)

In optical glass, the partial dispersion ratio (θ g, F) and Abbe number (ν of the partial dispersion in short wavelength region are indicated_d) it Between exist generally straight line relationship.The straight line for indicating the relationship is being the longitudinal axis, Abbe number using partial dispersion ratio (θ g, F) (ν_d) it is to be linked by 2 points that depict the partial dispersion of NSL7 and PBM2 when Abbe number straight in the orthogonal coordinates of horizontal axis Line indicates, which is referred to as positive gage line (referring to Fig.1).As the normal glass of regular line standard, although can be because of optics Glass producer and it is different, but each producer is nearly all defined with same inclination with intercept.(NSL7 and PBM2 are a plant formula meetings The optical glass of the small former manufacture of society, the Abbe number (ν of PBM2_d) be 36.3, partial dispersion ratio (θ g, F) be 0.5828, NSL7 Ah Shellfish number (ν_d) it be 60.5, partial dispersion ratio (θ g, F) is 0.5436.)

In recent years, more to use as partial dispersion ratio (θ g, F) lesser optical material due to the demand of optical design With 25 or more 40 Abbe number (ν below_d) glass.

In addition, being assembled in the optical element of the automobile-used optical apparatus such as vehicle-mounted vidicon in recent years or being assembled in projector, answer The optical element for the optical apparatus that print machine, laser printer and broadcasting can largely be generated heat in this way with machine etc. is used in higher The case where environment of temperature, constantly increases.Under such hot environment, the optical element of optical system is constituted, when using Temperature is easy significantly to change, and the temperature reaches 100 DEG C or more of situation also Chang Fasheng.At this point, because temperature variation is to light It is negatively affected caused by imaging characteristic of system etc., greatly to the degree that can not ignore, therefore, it is desirable to constitute a kind of optical system System is still difficult to therefore impact imaging characteristic etc. even if there is temperature variation.

When constituting the optical system for being difficult to have an impact due to temperature variation to imaging characteristic etc., folding when being risen by temperature The rate of penetrating is lower, the optical element that the temperature coefficient of relative index of refraction is made of the glass of negative value, with refraction when being increased by temperature Rate is got higher, in the case that the optical element that the temperature coefficient of relative index of refraction is made of the glass of positive value is used together, in energy Enough corrections are preferred on influence this point caused by imaging characteristic etc. due to temperature change.

On the other hand, in partial dispersion ratio (θ g, F) lesser optical material, by obtain various excellent light Property and the ingredient that contains are learned (for example, Nb₂O₅Ingredient, La₂O₃Ingredient etc.), what the temperature coefficient with relative index of refraction became larger Tendency.As this optical glass, it is known to glass component shown in such as patent document 1.

The vehicle-mounted lens especially used in recent years or exchange lens etc., the scene used under various environment increase It is more, so a kind of partial dispersion ratio of demand (θ g, F) is smaller, and the lesser optical glass of temperature coefficient of relative index of refraction.

Existing technical literature

Patent document 1: Japanese Unexamined Patent Application 58-125637 bulletin

Summary of the invention

However, glass disclosed in patent document 1, make partial dispersion than the Nb that becomes smaller₂O₅The content of ingredient is few, and TiO₂ Measure it is more, therefore the lens for being insufficient as correcting above-mentioned second order spectrum come using.Moreover, the content of alkalinous metal can not be said Less, the temperature coefficient of relative index of refraction is small.

The present invention is completed in view of above-described problem, the purpose is to obtain a kind of optical glass, the optical glass Flexion rate (n_d) and Abbe number (ν_d) in the range of expected, partial dispersion ratio (θ g, F) smaller and relative index of refraction temperature It is smaller to spend coefficient.

In order to solve the above problems, experimental study with keen determination has been repeated in the inventors of the present invention, as a result, it has been found that containing SiO₂ Ingredient and Nb₂O₅In the glass of ingredient, by by TiO₂Component amount is limited in 5.0% hereinafter, available have in expected model High refractive index and Abbe number (high dispersion), lower part dispersion in enclosing than and relative index of refraction the lesser optics of temperature coefficient Glass, so as to complete the present invention.

(1) a kind of optical glass contains SiO in terms of quality %₂Ingredient 20.0~45.0%, Nb₂O₅Ingredient 25.0~ 60.0%, TiO₂Ingredient 0~5.0%, mass ratio (Li₂O/Na₂O+K₂O) between 0.40~1.00, partial dispersion ratio (θ g, F) With Abbe number (ν_d) between meet (- 0.00162 × ν_d+ 0.620)≤(θ g, F)≤(- 0.00162 × ν_d+ 0.657) relationship, The temperature coefficient (40~60 DEG C) of relative index of refraction (589.29nm) is +6.0 × 10^-6~-5.0 × 10^-6(℃^-1) in the range of.

(2) optical glass according to (1), which is characterized in that mass ratio (Rn₂O/Nb₂O₅) it is 0.50 hereinafter, in formula, Rn is selected from Li, Na, K into one or more of group.

(3) optical glass according to (1) or (2), refractive index (n_d) and Abbe number (ν_d) meet (- 0.01 × ν_d+ 2.03)≤nd≤(-0.01×ν_d+ 2.13) relationship.

(4) a kind of preform, including optical glass described in any one of (1) to (3).

(5) a kind of optical element, including optical glass described in any one of (1) to (3).

(6) a kind of optical instrument has optical element described in (5).

In accordance with the invention it is possible to a kind of optical glass is obtained, the flexion rate (n of the optical glass_d) and Abbe number (ν_d) institute In the range of expectation, partial dispersion is relatively low and the temperature coefficient of relative index of refraction is smaller.

Detailed description of the invention

Fig. 1 is with partial dispersion ratio (θ g, F) for the longitudinal axis, Abbe number (ν_d) it is regular represented by the rectangular co-ordinate of horizontal axis Line schematic diagram；

Fig. 2 is the partial dispersion ratio (θ g, F) and Abbe number (ν for showing the embodiment of the present invention_d) relationship schematic diagram；

Fig. 3 is the refractive index (n for showing the embodiment of the present invention_d) and Abbe number (ν_d) relationship schematic diagram.

Specific embodiment

Optical glass of the invention, it is characterised in that: counted with the quality % that oxide conversion forms, contain SiO₂Ingredient 20.0~45.0%, Nb₂O₅Ingredient 25.0~60.0%, TiO₂Ingredient 0~5.0%, mass ratio (Li₂O/Na₂O+K₂It O) is 0.40 ~1.00, partial dispersion ratio (θ g, F) and Abbe number (ν_d) between meet (- 0.00162 × ν_d+ 0.620)≤(θ g, F)≤(- 0.00162×ν_d+ 0.657) temperature coefficient of relationship, relative index of refraction is smaller.

SiO containing specified amount₂Ingredient, Nb₂O₅Ingredient contains 5.0% or less TiO₂The optical glass of ingredient can obtain There must be the glass of the high refractive index and Abbe number (high dispersion), lower part dispersion ratio in expected range.In particular, by making TiO₂Content be maintained at 5.0% hereinafter, can holding part dispersion ratio (θ g, F) be small value while, reduce relative The temperature coefficient of rate.

Therefore, can obtain has expected high refractive index (n_d) and low Abbe number (ν_d) while, partial dispersion ratio (θ g, F) is smaller, advantageously reduces the chromatic aberation of optical system, and the lesser optical glass of temperature coefficient of relative index of refraction.

Hereinafter, the embodiment for optical glass of the present invention is described in detail, but the present invention is not limited to following Embodiment, can be carried out within the scope of the object of the invention it is appropriate change to be implemented.In addition, the portion about repeated explanation Point, although there is the case where description is omitted as appropriate, therefore the purport invented can't be limited.

[glass ingredient]

The compositing range for constituting each ingredient of optical glass of the present invention is as described below.In this specification, when being not specifically disclaimed, The content of each ingredient is all the quality % of glass total quality to form relative to oxide conversion to indicate.Here, " oxide Conversion composition " refers to the assumption that as oxide, complex salt, metal pentafluoride used in glass constituent raw material of the invention Object etc. melting when all decompose become oxide in the case where, the gross mass of the generation oxide is set as 100 mass %, To indicate the composition of various composition contained in glass.

<about essential component, any ingredient>

SiO₂Ingredient is essential component, and the stability that glass can be promoted to be formed reduces liquidus temperature, reduces optics glass Undesirable devitrification (generating crystal) in glass.

In particular, by by SiO₂The content of ingredient is set as 20.0% or more, can obtain that portion will not be significantly increased Color separation, which dissipates, to be compared, and the glass that devitrification resistance is excellent.Furthermore it is possible to reduce devitrification and coloring.Therefore, SiO₂The content of ingredient, It preferably 20.0% or more, is more preferably 23.0% or more, more preferably 25.0% or more.

On the other hand, by by SiO₂The content of ingredient is set as 45.0% hereinafter, refractive index is difficult to be lower and be easy to get The high refractive index expected, further, it is possible to inhibit the rising of partial dispersion ratio.Further, it is also possible to inhibit glass raw material molten with this Solution property it is low.Therefore, SiO₂The content of ingredient, preferably 45.0% or less, further preferably 43.0% or less, more preferably It is 41.5% or less, most preferably 40.0% or less.

SiO₂SiO can be used in ingredient₂、K₂SiF₆、Na₂SiF₆Deng as raw material.

Nb₂O₅Ingredient is essential component, can be improved refractive index, reduces Abbe number and partial dispersion ratio, and can be improved Devitrification resistance.

In particular, by by Nb₂O₅The content of ingredient is set as 25.0% or more, is adjusted in the ingredient of the scope of the invention It is whole, refractive index is improved until reaching objective optics constant, can reduce anomalous dispersion.Therefore, Nb₂O₅The content of ingredient, preferably It is 25.0% or more, further preferably 30.0 or more %, more preferably 35.5% or more.

On the other hand, by by Nb₂O₅The content of ingredient is set as 60.0% hereinafter, can reduce the expense of glass material.This Outside, additionally it is possible to inhibit melting temperature when glass manufacture to rise, and reduce because of Nb₂O₅The excess of ingredient is lost caused by containing Thoroughly.In addition it is possible to which deteriorating the chemical durability of glass is improved.Therefore, Nb₂O₅The content of ingredient, preferably 60.0% It below, is more preferably 55.0% or less, further preferably 50.0% or less, more preferably 48.0% or less.

Nb₂O₅Nb can be used in ingredient₂O₅Deng as raw material.

TiO₂Ingredient is any ingredient, when content is greater than 0%, can be improved refractive index, reduces Abbe number, and improve resistance to Increased devitrification resistance.On the other hand, if content excessively if partial dispersion ratio become larger.

Therefore, by by TiO₂The content of ingredient is set as 5.0% hereinafter, can reduce the coloring of glass, and raising is internal thoroughly Cross rate.In addition, thus partial dispersion ratio is difficult to rise, it is easy to get lower part dispersion ratio close to positive gage line, being expected. Therefore, TiO₂The content of ingredient, preferably 5.0% or less, further preferably 4.8% or less, more preferably less than 4.5%.

TiO₂TiO can be used in ingredient₂Deng as raw material.

K₂O ingredient is that any ingredient can make thermal expansion coefficient become larger, the temperature of relative index of refraction when content is greater than 0% Degree coefficient becomes smaller.

Therefore, K₂The content of O ingredient, preferably greater than 0%, further preferably greater than 0.3%, be most preferably be greater than 0.5%.

On the other hand, by by K₂The content of O ingredient is set as 10.0% hereinafter, be able to suppress the rising of partial dispersion ratio, Reduce devitrification.Therefore, K₂The content of O ingredient, preferably 10.0% or less, further preferably less than 8.0%, it is more preferably small In 5.0%.

K₂K can be used in O ingredient₂CO₃、KNO₃、KF、KHF₂、K₂SiF₆Deng as raw material.

B₂O₃Ingredient is any ingredient, when content is greater than 0%, the stability for promoting glass to be formed, in addition, because can Liquidus temperature is reduced, therefore can be improved devitrification resistance, and improves the meltability of glass raw material.Therefore, B₂O₃The content of ingredient, Preferably greater than 0%, it is further preferably greater than 0.3%, can more preferably be greater than 0.5%.

On the other hand, by by B₂O₃The content of ingredient is set as 7.0% hereinafter, be able to suppress the low of refractive index, and can Inhibit the rising of partial dispersion ratio, additionally it is possible to which deteriorating the chemical durability of glass is improved.Therefore, B₂O₃The content of ingredient, It preferably 7.0% or less, is more preferably 6.0% or less, more preferably 5.0% or less.

B₂O₃H can be used in ingredient₃BO₃、Na₂B₄O₇、Na₂B₄O₇·10H₂O、BPO₄Deng as raw material.

Li₂O ingredient is that any ingredient can make partial dispersion ratio be lower when content is greater than 0%, improves transmitance, makes Liquidus temperature reduces, and improves the meltability of glass raw material.Therefore, Li₂The content of O ingredient, preferably greater than 0%, further Preferably greater than 1.0%, it is further preferably greater than 3.0%.

On the other hand, by by Li₂The content of O ingredient is set as 15.0% hereinafter, be able to suppress the low of refractive index, and energy Devitrification caused by enough reductions contain because of its excess.

Therefore, Li₂The content of O ingredient, preferably 15.0% or less, further preferably 10.0% or less, more preferably Less than 7.0%.

Li₂Li can be used in O ingredient₂CO₃、LiNO₃, LiF etc. be used as raw material.

Na₂O ingredient is that any ingredient can make partial dispersion ratio be lower when content is greater than 0%, and thermal expansion coefficient becomes Greatly, and the temperature coefficient of relative index of refraction is made to become smaller.Therefore, Na₂The content of O ingredient, preferably greater than 0%, further preferably For greater than 1.0%, can more preferably be greater than 3.0%.

On the other hand, by by Na₂The content of O ingredient is set as 15.0% hereinafter, to be able to suppress refractive index low, and can Devitrification caused by reduction contains because of its excess.

Therefore, Na₂The content of O ingredient, preferably 15.0% or less, further preferably 10.0% or less, more preferably Less than 8.0%.

Na₂Na can be used in O ingredient₂CO₃、NaNO₃、NaF、Na₂SiF₆Deng as raw material.

Rn₂O ingredient (in formula, Rn is selected from Li, Na, K institute into one or more of group) for any ingredient, content it When (quality and) is greater than 0%, the temperature coefficient of relative index of refraction can be made to become smaller.Therefore, Rn₂The sum of O ingredient, preferably greatly In 0%, further preferably greater than 3.0%, further preferably greater than 5.0%, further preferably greater than 8.0%.

On the other hand, by by Rn₂O ingredient (in formula, Rn be selected from Li, Na, K at one or more of group) contain The sum of amount (quality and) is set as 20.0% hereinafter, the viscosity in glass can be reinforced, and improves formability.It is therefore preferable that being It 20.0% or less, is more preferably 19.0% or less, more preferably 18.0% or less.

ZrO₂Ingredient is that any ingredient can be improved the refractive index and Abbe number of glass when content is greater than 0%, is reduced Partial dispersion ratio, and can be improved devitrification resistance.Furthermore, devitrification and coloring can also be reduced.Therefore, ZrO₂The content of ingredient, Preferably greater than 0%, it is further preferably greater than 1.0%, can further preferably be greater than 3.0%.

On the other hand, by by ZrO₂The content of ingredient is set as 15.0% hereinafter, can reduce devitrification, and be easy to get The glass of homogeneous.Therefore, ZrO₂The content of ingredient, the upper limit is preferably 15.0% or less, further preferably 10.0% hereinafter, Further preferably 8.0% or less.

ZrO₂ZrO can be used in ingredient₂、ZrF₄Deng as raw material.

MgO ingredient is that any ingredient can reduce the melting temperature of glass when content is greater than 0%.

On the other hand, by the way that the content of MgO ingredient is set as 10.0% hereinafter, can be in inhibiting low same of refractive index When, reduce devitrification.Therefore, the content of MgO ingredient, preferably 10.0% or less, further preferably less than 5.0%, more preferably For less than 3.0%.

MgO, MgCO can be used in MgO ingredient₃、MgF₂Deng as raw material.

CaO ingredient is any ingredient, when content is greater than 0%, can reduce Ah while reducing glass material expense Shellfish number and devitrification, and can be improved the meltability of glass raw material.

On the other hand, by the way that the content of CaO ingredient is set as 10.0% hereinafter, being able to suppress the low and Abbe of refractive index Several risings and the rising of partial dispersion ratio, and can reduce devitrification.Therefore, the content of CaO ingredient, preferably 10.0% Below, it is further preferably less than 7.0%, more preferably less than 5.0%.

CaCO can be used in CaO ingredient₃、CaF₂Deng as raw material.

SrO ingredient is any ingredient, when content is greater than 0%, can be improved refractive index, and improve devitrification resistance.

In particular, by the way that the content of SrO ingredient is set as 10.0% hereinafter, can inhibit the deterioration of chemical durability.Cause This, the content of SrO ingredient, preferably 10.0% or less, further preferably less than 8.0%, more preferably less than 6.0%, more Preferably less than 5.0%.

Sr (NO can be used in SrO ingredient₃)₂、SrF₂Deng as raw material.

BaO ingredient is that any ingredient can be improved refractive index and devitrification resistance, and make heat when content is greater than 0% The coefficient of expansion becomes larger, and the temperature coefficient of relative index of refraction is made to become smaller.

In particular, by the way that the content of BaO ingredient is set as 5.0% hereinafter, being able to suppress the low and Abbe number of refractive index Rising and partial dispersion ratio rising, and can reduce devitrification.Therefore, the content of BaO ingredient, preferably 5.0% with Under, further preferably less than 4.0%, more preferably less than 3.0%, more preferably less than 1.0%.

BaCO can be used in BaO ingredient₃、Ba(NO₃)₂Deng as raw material.

ZnO component is any ingredient, when content is greater than 0%, glass cheap and devitrification resistance can be made to improve, And it can reduce glass transition point.Therefore, the content of ZnO component, preferably greater than 0%, further preferably greater than It 0.1%, more preferably can be for greater than 0.3%.

On the other hand, by the way that the content of ZnO component is set as 10.0% hereinafter, can reduce devitrification and coloring.Therefore, The content of ZnO component, preferably 10.0% or less, further preferably 8.0% or less, further preferably less than 6.0%.

La₂O₃Ingredient, Gd₂O₃Ingredient, Y₂O₃Ingredient and Yb₂O₃Ingredient is any ingredient, the content of wherein at least one ingredient When greater than 0%, refractive index can be improved, and partial dispersion ratio is made to become smaller.

In particular, by by La₂O₃Ingredient, Gd₂O₃Ingredient, Y₂O₃Ingredient and Yb₂O₃The respective content of ingredient is set as 10.0% Hereinafter, being able to suppress the rising of Abbe number, devitrification is reduced, and reduce Master Cost.Therefore, La₂O₃Ingredient, Gd₂O₃Ingredient, Y₂O₃ Ingredient and Yb₂O₃The respective content of ingredient, preferably 10.0% or less, more preferably 7.0% or less, more preferably less than 5.0%.

La₂O₃Ingredient, Gd₂O₃Ingredient, Y₂O₃Ingredient and Yb₂O₃La can be used in ingredient₂O₃、La(NO₃)₃·XH₂(X is to appoint to O The integer of meaning), Y₂O₃、YF₃、Gd₂O₃、GdF₃、Yb₂O₃Deng as raw material.

Ta₂O₅Ingredient is any ingredient, when content is greater than 0%, can be improved refractive index, reduces Abbe number and part color Ratio is dissipated, and can be improved devitrification resistance.

On the other hand, by by Ta₂O₅The content of ingredient is set as 10.0% hereinafter, can reduce as rare mineral resources Ta₂O₅The usage amount of ingredient, and glass is more prone to low temperature melting, therefore can reduce the producing cost of glass.In addition, Thus, it is possible to reduce because of Ta₂O₅Glass devitrification caused by the excess of ingredient contains.Therefore, Ta₂O₅The content of ingredient, preferably 10.0% or less, it is further preferably less than 5.0%, more preferably less than 3.0%, more preferably less than 1.0%.Especially from For the viewpoint for reducing the Master Cost of glass, Ta can not contained₂O₅Ingredient.

Ta₂O₅Ta can be used in ingredient₂O₅Deng as raw material.

WO₃Ingredient is any ingredient, and when content is greater than 0%, can be improved refractive index reduces Abbe number, improves devitrification Property, and improve the meltability of glass raw material.

On the other hand, by by WO₃The content of ingredient is set as 10.0% hereinafter, the partial dispersion ratio of glass can be made to be difficult to The coloring for rising, and reducing glass improves internal transmitance.Therefore, WO₃The content of ingredient, preferably 10.0% or less, into One step is preferably less than 5.0%, more preferably less than 3.0%, more preferably less than 1.0%.

WO₃WO can be used in ingredient₃Deng as raw material.

P₂O₅Ingredient is that any ingredient can be improved the stability of glass when content is greater than 0%.

Another side, by by P₂O₅The content of ingredient is set as 10.0% hereinafter, can reduce because of P₂O₅The excess of ingredient contains Caused by devitrification.Therefore, P₂O₅The content of ingredient, preferably 10.0% or less, further preferably less than 5.0%, more preferably For less than 3.0%.

P₂O₅Al (PO can be used in ingredient₃)₃、Ca(PO₃)₂、Ba(PO₃)₂、BPO₄、H₃PO₄Deng as raw material.

GeO₂Ingredient is that any ingredient can be improved refractive index, and can reduce devitrification when content is greater than 0%.

On the other hand, by by GeO₂The content of ingredient is set as 10.0% hereinafter, reducing the GeO of somewhat expensive₂Ingredient makes Dosage, so can reduce the Master Cost of glass.Therefore, GeO₂The content of ingredient, preferably 10.0% or less, further it is excellent It is selected as less than 5.0%, more preferably less than 3.0%.

GeO₂GeO can be used in ingredient₂Deng as raw material.

Al₂O₃Ingredient and Ga₂O₃Ingredient is any ingredient, when wherein at least the content of any one ingredient is greater than 0%, energy Refractive index is enough improved, and is able to ascend devitrification resistance.

On the other hand, by by Al₂O₃Ingredient and Ga₂O₃The content of ingredient be set to 10.0% hereinafter, can reduce because Al₂O₃Ingredient or Ga₂O₃Devitrification caused by the excess of ingredient contains.Therefore, Al₂O₃Ingredient and Ga₂O₃The respective content of ingredient, Preferably 10.0% or less, it is further preferably less than 5.0%, more preferably less than 3.0%.

Al₂O₃Ingredient and Ga₂O₃Al can be used in ingredient₂O₃、Al(OH)₃、AlF₃、Ga₂O₃、Ga(OH)₃Deng as raw material.

Bi₂O₃Ingredient is any ingredient, and when content is greater than 0%, can be improved refractive index reduces Abbe number, and can drop Reduced TG transition point.

On the other hand, by by Bi₂O₃The content of ingredient is set as 10.0% hereinafter, partial dispersion ratio can be made to be difficult to rise, Further, it is possible to which the coloring for reducing glass improves internal transmitance.Therefore, Bi₂O₃The content of ingredient, preferably 10.0% or less, into One step is preferably less than 5.0%, more preferably less than 3.0%, more preferably less than 1.0%.

Bi₂O₃Bi can be used in ingredient₂O₃Deng as raw material.

TeO₂Ingredient is any ingredient, when content is greater than 0%, can be improved refractive index, reduces partial dispersion ratio, and energy Enough reduce glass transition point.

On the other hand, by by TeO₂The content of ingredient is set as 5.0% hereinafter, the coloring that can reduce glass improves inside Transmitance.In addition, passing through the TeO for reducing somewhat expensive₂The use of ingredient can obtain the cheap glass of Master Cost.Therefore, TeO₂The content of ingredient, preferably 5.0% or less, more preferably less than 3.0%, more preferably less than 1.0%.

TeO₂TeO can be used in ingredient₂Deng as raw material.

SnO₂Ingredient is any ingredient, when content is greater than 0%, the glass after melting can be made limpid (defoaming), and energy Enough improve the visible light transmittance of glass.

On the other hand, by by SnO₂The content of ingredient is set as 1.0% hereinafter, can make to lead because of the reduction of melten glass The coloring of the glass of cause or the devitrification of glass are difficult to happen.Further, since SnO₂(especially Pt etc. is expensive with melting equipment for ingredient Metal) between alloying reduce, and can it is expected extend melting equipment service life.Therefore, SnO₂The content of ingredient, preferably It is 1.0% or less, further preferably less than 0.5%, more preferably less than 0.1%.

SnO₂SnO, SnO can be used in ingredient₂、SnF₂、SnF₄Deng as raw material.

Sb₂O₃Ingredient is that any ingredient promotes disappearing for glass when content is greater than 0% in optical glass of the invention Bubble, makes glass become limpid.By by Sb₂O₃The content of ingredient is set as 1.0% hereinafter, glass can be made to be difficult to produce when dissolving Raw excessive bubble, Sb₂O₃Alloying is difficult to happen between ingredient and melting equipment (noble metals such as especially Pt).Therefore, Sb₂O₃The content of ingredient, preferably 1.0%, further preferably 0.8%, more preferably 0.6%.

Sb₂O₃Sb can be used in ingredient₂O₃、Sb₂O₅、Na₂H₂Sb₂O₇·5H₂O etc. is used as raw material.

In addition, as the ingredient that glass is limpid, defoams is made, however it is not limited to above-mentioned SnO₂Ingredient or Sb₂O₃Ingredient can make With clarifying agent known in glass manufacturing area, defoaming agent or these combination.

Li₂O and Na₂O and K₂The ratio of the quality sum of O, preferably 1.38 or less.Thus, it is possible to inhibit the deterioration of increased devitrification resistance.Cause This, mass ratio Li₂O/(Na₂O+K₂O), preferably 1.38 or less, further preferably 1.00 or less, further preferably 0.95 Below, it is more preferably 0.90 or less.

On the other hand, by mass ratio Li₂O/(Na₂O+K₂When O) being set as 0.40 or more, partial dispersion can be obtained and compared Small glass.It is therefore preferable that for 0.40 or more, further preferably 0.45 or more, more preferably 0.50 or more.

TiO₂With Li₂The ratio of O, preferably 1.42 or less.Thus, it is possible to reduce the devitrification of glass.Therefore, mass ratio TiO₂/ Li₂It O, is preferably 1.00 or less, further preferably 0.95 or less, more preferably 0.90 or less.

On the other hand, mass ratio TiO₂/Li₂When O is greater than 0, transmitance can be made not deteriorate, and make partial dispersion than becoming It is small.It is therefore preferable that for greater than 0, further preferably 0.20 or more, further preferably 0.25 or more, more preferably 0.30 with On.

Rn₂O ingredient (in formula, Rn is selected from Li, Na, K into one or more of group) and Nb₂O₅Ratio, preferably 0.50 or less.Thus there can be expected refractive index, and partial dispersion ratio becomes smaller.Therefore, mass ratio Rn₂O/Nb₂O₅, preferably It is 0.50 or less, further preferably 0.48 or less, further preferably 0.45 or less.

On the other hand, by by mass ratio Rn₂O/Nb₂O₅It is set as 0.10 or more, can reduce the temperature system of relative index of refraction Number.It is therefore preferable that for 0.10 or more, further preferably 0.20 or more, more preferably 0.25 or more.

SiO₂With Nb₂O₅Ratio, preferably 0.50 or more.It is possible thereby to which partial dispersion ratio is made to become smaller, the stability of glass becomes It is good.Therefore, lower limit is preferably 0.50 or more, further preferably 0.55 or more, more preferably 0.60 or more.

On the other hand, SiO₂With Nb₂O₅Ratio, preferably 1.00 or less.Therefore, the upper limit is preferably 1.00 or less, into one Step preferably 0.95 or less, more preferably 0.90 or less.Thus, it is possible to obtain high refractive index and be expected Abbe number.

TiO₂、Nb₂O₅、ZrO₂It is total, preferably 35.0% or more.Partial dispersion ratio becomes smaller as a result, refractive index and Ah Shellfish number is the numerical value expected.Therefore, quality and (TiO₂+Nb₂O₅+ZrO₂), preferably 35.0% or more, further preferably It 38.0% or more, is more preferably 40.0% or more, more preferably 45.0% or more.

On the other hand, quality and (TiO₂+Nb₂O₅+ZrO₂), preferably 70.0% or less.Thereby, it is possible to inhibit increased devitrification resistance Deterioration, transmitance is more preferable.Preferably 70.0% or less, be further preferably less than 65.0%, more preferably less than 60.0%, More preferably less than 58.0%.

ZrO₂With Nb₂O₅Ratio, preferably 0.01 or more.Partial dispersion ratio becomes smaller as a result, and possesses the same of high refractive index When increased devitrification resistance it is more preferable.Therefore, mass ratio ZrO₂/Nb₂O₅, preferably 0.01 or more, further preferably 0.05 or more, more preferably For greater than 0.10.

On the other hand, mass ratio ZrO₂/Nb₂O₅, preferably 0.25 or less.The stability of glass is more preferable as a result, can press down The rising of Abbe number processed.Preferably 0.25 or less, it is more preferably 0.22 or less, is more preferably 0.20 or less, more excellent It is selected as 0.15 or less.

Na₂O ingredient and Rn₂O ingredient (in formula, Rn be selected from Li, Na, K at one or more of group) ratio, preferably It is 0.25 or more.The temperature coefficient of relative index of refraction becomes smaller as a result,.Therefore, mass ratio Na₂O/Rn₂O, preferably 0.25 or more, Further preferably 0.27 or more, it is more preferably 0.30 or more.

On the other hand, mass ratio Na₂O/Rn₂O is preferably 0.65 or less.Thereby, it is possible to inhibit to cause because reheating is molded Devitrification and refractive index it is low.It preferably 0.65 or less, is more preferably 0.63 or less, more preferably 0.60 or less.

RO ingredient (in formula, R be selected from Mg, Ca, Sr, Ba at one or more of group) content summation (quality With), when being greater than 0%, adjustable expected refractive index and dispersion.Therefore, the content of RO ingredient, preferably greater than 0%, into One step is preferably greater than 0.5%, more preferably higher than 1.5%.

On the other hand, the summation of the content of RO ingredient, preferably less than 9.0%.Thereby, it is possible to inhibit the mistake because of RO ingredient Glass refraction is low and devitrification resistance low caused by amount contains.Therefore, the quality of RO ingredient and, preferably less than 9.0%, it is further preferably less than 7.0%, further preferably 6.5% or less, more preferably 6.0% or less.

Ln₂O₃Ingredient (in formula, Ln be selected from La, Gd, Y, Yb at one or more of group) content summation (matter Amount and), preferably less than 5.0%.Thereby, it is possible to inhibit because of Ln₂O₃Glass refraction is low caused by the excess of ingredient contains It is lower and devitrification resistance low.Therefore, Ln₂O₃The quality of ingredient and, preferably less than 5.0%, further preferably 4.5% with Under, more preferably 4.0% or less.

<about the ingredient that should not contain>

Next, for the ingredient that should not contain in optical glass of the present invention, and be not suitable for containing ingredient carry out Explanation.

In the range of not damaging glass performance of the invention, other compositions are added according to required.However, in addition to Ti, Zr, Except Nb, W, La, Gd, Y, Yb, Lu, the various transiting metal components such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, Mo are respectively with independent Or compound kenel is when containing, and it is even a small amount of containing can still make glass coloration, and have and absorb specific wavelength in visible range Light property, therefore, especially using visible range wavelength optical glass in, preferably contain substantially no.

In addition, the lead compounds such as PbO and As₂O₃Equal arsenic compounds, due to being to the higher ingredient of carrying capacity of environment, ideal is Substantive Shangdi does not contain, that is, other than unavoidable be mixed into, to be entirely free of.

In turn, each ingredient of Th, Cd, Tl, Os, Be, Se is considered as harmful chemical substance in recent years, and avoid using Tendency, be not only the manufacturing step in glass, or even in procedure of processing and until the waste treatment after product, all must Must have in response to the measure in environmental cure.Therefore, by paying attention to preferably containing substantially no for the viewpoint of influence environmentally These ingredients.

[manufacturing method]

Optical glass of the invention, such as can be made in the following manner.That is, making each ingredient in defined content model In enclosing, above-mentioned raw materials are equably mixed, then will be carried out in the mixture investment platinum crucible, silica crucible or alumina crucible of preparation It tentatively melts and then is put into golden crucible, platinum crucible, platinum alloy crucibles or iridium crucible, in 1000~1400 DEG C of temperature model Enclose interior melting 3~5 hours, stirring make it uniformly and defoam and etc. after, after being cooled to 900~1200 DEG C of temperature, into The stirring of row terminal stage is to remove lines, then pours and cast from mold, is subject to slow cooling, is thus made.

<physical property>

Optical glass of the invention, the Abbe number with high refractive index and prescribed limit.

Refractive index (the n of optical glass of the invention_d), lower limit is preferably 1.70 or more, further preferably 1.72 with Above, more preferably 1.75 or more.The upper limit of the refractive index, preferably 1.90 or less, further preferably 1.88 or less, further Preferably 1.85 or less, 1.83 or less are more preferably.

Abbe number (the ν of optical glass of the invention_d), lower limit is preferably 25.0, is more preferably 25.5, more preferable It is 26.0.On the other hand, the Abbe number (ν of optical glass of the invention_d), the upper limit is preferably 35.0, is more preferably 34.0,33.0 are more preferably.

So, optical glass of the invention has above-mentioned refractive index and Abbe number, can be in playing function in optical design Effect, other than it can it is expected high imaging characteristic etc., can also it is expected the miniaturization of optical system, and may make oneself in optical design Increased by degree.

Here, optical glass of the invention, refractive index (n_d) and Abbe number (ν_d) preferably meet (- 0.01 × ν_d+2.03) ≤n_d≤(-0.01×ν_d+ 2.13) relationship.The glass that the present invention specifically forms, refractive index (n_d) and Abbe number (ν_d) full The foot relationship, can obtain stable glass.

Therefore, optical glass of the invention, refractive index (n_d) and Abbe number (ν_d) preferably meet n_d≥(-0.01×ν_d+ 2.03) relationship, further preferably meets n_d≥(-0.01×ν_d+ 2.05) relationship.

On the other hand, optical glass of the invention, refractive index (n_d) and Abbe number (ν_d) preferably meet n_d≤(-0.01× ν_d+ 2.13) relationship, further preferably meets n_d≤(-0.01×ν_d+ 2.10) relationship.

Optical glass of the invention has lower partial dispersion ratio (θ g, F).

More specifically, the partial dispersion ratio (θ g, F) of optical glass of the invention and Abbe number (ν_d) between, preferably Meet (- 0.00162 × ν_d+ 0.620)≤(θ g, F)≤(- 0.00162 × ν_d+ 0.657) relationship.

Therefore, optical glass of the invention, partial dispersion ratio (θ g, F) and Abbe number (ν_d) it is preferably to meet θ g, F >=(- 0.00162×ν_d+ 0.620) relationship, further preferably θ g, F >=(- 0.00162 × ν_d+ 0.630) relationship.

On the other hand, optical glass of the invention, partial dispersion ratio (θ g, F) and Abbe number (ν_d) preferably meet θ g, F ≤(-0.00162×ν_d+ 0.657) relationship further preferably meets θ g, F≤(- 0.00162 × ν_d+ 0.650) relationship.

Thereby, it is possible to obtain the optical glass with lower part dispersion ratio (θ g, F), which is formed by optics Element can play effect when reducing the chromatic aberation of optical system.

In addition, especially in Abbe number (ν_d) in lesser region, the numerical value of the partial dispersion ratio (θ g, F) of general glass Higher compared to positive gage line, taking horizontal axis is Abbe number (ν_d), the longitudinal axis be partial dispersion ratio (θ g, F) when, the part color of general glass It dissipates than (θ g, F) and Abbe number (ν_d) relationship as shown in the curve bigger than the gradient of positive gage line.Above-mentioned partial dispersion ratio (θ G, F) and Abbe number (ν_d) relational expression in, show through the straight line bigger than the gradient of positive gage line and provide their pass System, available partial dispersion ratio (θ g, the F) glass smaller than general glass.

In addition, optical glass of the invention, the temperature coefficient (dn/dT) of relative index of refraction takes low numerical value.

More specifically, the temperature coefficient of the relative index of refraction of optical glass of the present invention, upper limit value preferably+6.0 × 10^-6℃^-1, further preferably+5.5 × 10^-6℃^-1, more preferably+5.0 × 10^-6℃^-1, and can use the upper limit value or compared on this The numerical value of limit value lower (minus value side).

On the other hand, the temperature coefficient of the relative index of refraction of optical glass of the present invention, lower limit value are preferably -5.0 × 10^-6 ℃^-1, further preferably -1.0 × 10^-6℃^-1, more preferably -0.5 × 10^-6℃^-1, and can use the lower limit value or compared with the lower limit It is worth the numerical value of higher (positive value side).

Wherein, in the refractive index (n with 1.70 or more_d), and there are 25 or more 35 Abbe number (ν below_d) glass In, the lower glass of the temperature coefficient of relative index of refraction is actually rare so as to because the imaging caused by temperature change it is out of focus etc. The corrected selection of situation becomes more, can be more easily accomplished the correction.Therefore, by by the temperature coefficient of relative index of refraction It is set as above-mentioned range, can aid in correction because the imaging caused by temperature change is out of focus etc..

The temperature coefficient of the relative index of refraction of optical glass of the present invention, refers to and optical glass is in the air of same temperature Refractive index (589.29nm) temperature coefficient, by by temperature from when being changed to 60 DEG C for 40 DEG C, variable quantity corresponding to every 1 DEG C (℃^-1) indicate.

Optical glass of the invention, average thermal linear expansion coefficient α at 100~300 DEG C, preferably 80 (10^-7℃^-1) More than.That is, optical glass of the invention, average thermal linear expansion coefficient α at 100~300 DEG C, lower limit is preferably 80 (10^-7 ℃^-1) more than, further preferably 85 (10^-7℃^-1) more than, further preferably 90 (10^-7℃^-1) more than.

In general, in glass processing, the coefficient of mean linear thermal expansion α is easy to happen rupture when larger, it is therefore desirable for flat Equal coefficient of linear thermal expansion α is small value.On the other hand, just lower with the temperature coefficient of relative index of refraction, and average linear thermal expansion system Number α is that the glass material being worth greatly combines and for the viewpoint of engagement, it is generally desirable to the numerical value of the coefficient of mean linear thermal expansion α and the glass Glass material is same or similar.

Wherein, there is 1.70 or more refractive index (n_d), and there are 25 or more 35 Abbe number (ν below_d) glass in, The biggish glass material of the coefficient of mean linear thermal expansion α is few, when the glass material with low-refraction, low dispersion is applied in combination, such as The coefficient of mean linear thermal expansion α shown in the present invention be worth greatly it is more useful.

Optical glass of the invention, it is generally desirable to which specific gravity is smaller.More specifically, the specific gravity of optical glass of the present invention is preferred For 5.00 (g/cm³) below.Thereby, it is possible to mitigate the quality of optical element and the optical instrument using the optical element, to light The lightweight for learning instrument can contribute.

Therefore, the specific gravity of optical glass of the present invention, the upper limit are preferably 5.00, more preferably 4.70, more preferably 4.50. In addition, the specific gravity of optical glass of the present invention, majority is general 2.80 or more, further specifically 2.90 or more, in more detail For be 3.00 or more.

The specific gravity of optical glass of the present invention, can standard JOGIS05-1975 " optical glass according to Japanese Optical Glass industry Specific gravity measuring method " measured.

[preform and optical element]

Can be used molded such as reheating, compression molding precise punch forming method, by manufactured optical glass Lai Produce glass forming body.That is, the preform of compression molding can be produced by optical glass, and to the preform into After row reheating is molded, attrition process is carried out to make glass forming body；Or to manufactured preforming using attrition process Material carries out precise punch forming to make glass forming body etc..In addition, the method for production glass forming body, however it is not limited to above-mentioned These methods.

As above the glass forming body made is applicable to various optical elements, and purposes is particularly preferred for lens or prism Equal optical elements.Accordingly, for the transmitted light for the optical system for being provided with optical element, can mitigate due to caused by chromatic aberation Bleeding.Therefore, subject can be more accurately showed when which being used for camera, this is used for optical elements Expected image is projected in projector Shi Kegeng high vividness.

Embodiment

The composition and refractive index (n of the embodiment of the present invention (No.1~No.12) and comparative example_d), Abbe number (ν_d), portion Color separation is dissipated than (θ g, F), the temperature coefficient (dn/dT) of relative index of refraction, the coefficient of mean linear thermal expansion (100-300 DEG C), specific gravity As a result shown in table 1~table 2.In addition, embodiment below is only used for the purpose illustrated, the present invention is not limited to the embodiments such as this.

The glass of the embodiment of the present invention and comparative example, the raw material of each ingredient are all its corresponding oxide of selection, hydrogen High-purity raw used in the general optical glass such as oxide, carbonate, nitrate, fluoride, metaphosphoric acid compound, then will These raw materials are weighed with becoming the ratio of components of each Examples and Comparative Examples shown in table, and equably after mixing, put into stone In crucible (platinum crucible, alumina crucible also can be used according to the meltbility of glass) processed, and it is difficult according to the melting of glass composition Yi Du after melting 0.5~5 hour, is moved into platinum crucible with electric furnace within the temperature range of 1100~1400 DEG C and is stirred for making it Uniformly and defoam and etc. after, after being cooled to 1000~1200 DEG C, be again stirring for making it uniformly, then pour and cast from mold, It is subject to slow cooling, glass is made.

Refractive index (the n of the glass of Examples and Comparative Examples_d), Abbe number (ν_d) and partial dispersion ratio (θ g, F), according to Japan Optical Glass Industrial understands standard JOGIS01-2003 to be measured.

The temperature coefficient (dn/dT) of the relative index of refraction of the glass of Examples and Comparative Examples, according to Japanese Optical Glass work It is dry in method documented by industry meeting standard JOGIS18-2008 " measuring method of the temperature coefficient of the refractive index of optical glass " Relate to method, the numerical value for light temperature coefficient of relative index of refraction at 40~60 DEG C that measurement wavelength is 589.29nm.

In addition, the coefficient of mean linear thermal expansion (100-300 DEG C) of the glass of Examples and Comparative Examples, according to Japanese Optical glass Glass industry meeting standard JOGIS08-2003 " measuring method of the thermal expansion of optical glass ", passes through the elongation of measuring temperature and sample Thermal dilatometry obtained from the relationship of rate and find out.

The specific gravity of glass of Examples and Comparative Examples, can standard JOGIS05-1975 " optics according to Japanese Optical Glass industry The measuring method of specific gravity of glass " is measured.

[table 1]

[table 2]

The optical glass of the embodiment of the present invention, refractive index (n_d) be 1.70 or more, be more specifically 1.72 or more, and And the refractive index (n_d) by 1.90 or less, be more specifically 1.88 hereinafter, in the range of expecting.

In addition, the optical glass of the embodiment of the present invention, Abbe number (ν_d) be 25 or more, be more specifically 26 or more, and And the Abbe number (ν_d) by 35 hereinafter, expect in the range of.

As shown in above-mentioned each table, the optical glass of the embodiment of the present invention, partial dispersion ratio (θ g, F) and Abbe number (ν_d) Between meet (- 0.00162 × ν_d+ 0.620)≤(θ g, F)≤(- 0.00162 × ν_d+ 0.657) relationship, it is more specifically full Foot (- 0.00162 × ν_d+ 0.630)≤(θ g, F)≤(- 0.00162 × ν_d+ 0.650) relationship.That is, about the embodiment of the present application Glass partial dispersion ratio (θ g, F) and Abbe number (ν_d) between relationship, as a result as shown in Figure 2.

On the other hand, the optical glass of comparative example, does not meet (- 0.00162 × ν_d+ 0.620)≤(θ g, F)≤(- 0.00162×ν_d+ 0.657) relationship.

Moreover, the optical glass of the embodiment of the present invention, refractive index (n_d) and Abbe number (ν_d) between meet (- 0.01 × ν_d +2.03)≤n_d≤(-0.01×ν_d+ 2.13) relationship more specifically meets (- 0.01 × ν_d+2.05)≤n_d≤(-0.01 ×ν_d+ 2.10) relationship.That is, refractive index (the n of the glass about the embodiment of the present application_d) and Abbe number (ν_d) between relationship, As a result as shown in Figure 3.

It is as shown in the table, and the optical glass of embodiment, the temperature coefficient of relative index of refraction is +6.0 × 10^-6~-0.5 × 10^-6(℃^-1) in the range of, it is in desired range.

Moreover, optical glass of the invention, the coefficient of mean linear thermal expansion α at 100~300 DEG C is 80 (10^-7℃^-1) with On.

In addition, the optical glass of the embodiment of the present invention, specific gravity is 5.00 or less.Therefore, it should be clear from, the present invention is real The specific gravity for applying the optical glass of example is smaller.

In turn, glass block is formed using the optical glass of the embodiment of the present invention, and the glass block is ground and is ground Mill, is processed into lens and prism shape.As a result, the shape of miscellaneous lens and prism can be steadily processed into.

More than, it is described the invention in detail with the purpose of illustration, but the present embodiment is only used for the purpose illustrated, this Field is it will be appreciated by the skilled person that can carry out various changes in the case where not departing from thought and range of the invention.

Claims (6)

1. a kind of optical glass contains SiO in terms of quality %₂Ingredient 20.0~45.0%, Nb₂O₅Ingredient 25.0~60.0%, TiO₂Ingredient 0~5.0%, mass ratio (Li₂O/Na₂O+K₂O) between 0.40~1.00, partial dispersion ratio (θ g, F) and Abbe Number (ν_d) between meet (- 0.00162 × ν_d+ 0.620)≤(θ g, F)≤(- 0.00162 × ν_d+ 0.657) relationship, it is opposite to roll over The temperature coefficient (40~60 DEG C) of rate (589.29nm) is penetrated+6.0 × 10^-6~-5.0 × 10^-6(℃^-1) in the range of.

2. optical glass according to claim 1, which is characterized in that

Mass ratio (Rn₂O/Nb₂O₅) it is 0.50 hereinafter, Rn is selected from Li, Na, K institute into one or more of group in formula.

3. optical glass according to claim 1 or 2, wherein

Refractive index (n_d) and Abbe number (ν_d) meet (- 0.01 × ν_d+2.03)≤n_d≤(-0.01×ν_d+ 2.13) relationship.

4. a kind of preform, including optical glass of any of claims 1 or 2.

5. a kind of optical element, including optical glass of any of claims 1 or 2.

6. a kind of optical instrument has optical element as claimed in claim 5.