CN118159881A - Optical filter and near infrared cut-off filter - Google Patents
Optical filter and near infrared cut-off filter Download PDFInfo
- Publication number
- CN118159881A CN118159881A CN202280070504.3A CN202280070504A CN118159881A CN 118159881 A CN118159881 A CN 118159881A CN 202280070504 A CN202280070504 A CN 202280070504A CN 118159881 A CN118159881 A CN 118159881A
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- Prior art keywords
- filter
- glass
- light
- protective film
- glass plate
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- 230000003287 optical effect Effects 0.000 title claims abstract description 53
- 239000011521 glass Substances 0.000 claims abstract description 194
- 230000001681 protective effect Effects 0.000 claims abstract description 89
- 230000002093 peripheral effect Effects 0.000 claims abstract description 34
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 15
- 239000005365 phosphate glass Substances 0.000 claims description 11
- 229910052593 corundum Inorganic materials 0.000 claims description 9
- 229910001845 yogo sapphire Inorganic materials 0.000 claims description 9
- 229910004742 Na2 O Inorganic materials 0.000 claims description 6
- 150000001450 anions Chemical class 0.000 claims description 4
- 239000005303 fluorophosphate glass Substances 0.000 claims description 4
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims description 3
- RYYWUUFWQRZTIU-UHFFFAOYSA-K thiophosphate Chemical compound [O-]P([O-])([O-])=S RYYWUUFWQRZTIU-UHFFFAOYSA-K 0.000 claims description 3
- 239000010408 film Substances 0.000 description 132
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 21
- 230000000694 effects Effects 0.000 description 16
- 238000005530 etching Methods 0.000 description 14
- 230000006866 deterioration Effects 0.000 description 13
- 238000004519 manufacturing process Methods 0.000 description 13
- 238000000034 method Methods 0.000 description 13
- 238000002844 melting Methods 0.000 description 12
- 230000008018 melting Effects 0.000 description 12
- 230000000087 stabilizing effect Effects 0.000 description 10
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 238000002834 transmittance Methods 0.000 description 5
- 238000000227 grinding Methods 0.000 description 4
- 238000007733 ion plating Methods 0.000 description 4
- 238000004544 sputter deposition Methods 0.000 description 4
- 238000001771 vacuum deposition Methods 0.000 description 4
- 229910018068 Li 2 O Inorganic materials 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 3
- 230000002542 deteriorative effect Effects 0.000 description 3
- 238000003384 imaging method Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 238000001000 micrograph Methods 0.000 description 3
- 238000000465 moulding Methods 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 239000006059 cover glass Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 239000010432 diamond Substances 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000007496 glass forming Methods 0.000 description 2
- 238000010884 ion-beam technique Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 1
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 238000006124 Pilkington process Methods 0.000 description 1
- 241000722270 Regulus Species 0.000 description 1
- BLBVLMPUSLFQNF-UHFFFAOYSA-N S.P(O)(O)(O)=O Chemical compound S.P(O)(O)(O)=O BLBVLMPUSLFQNF-UHFFFAOYSA-N 0.000 description 1
- 206010040925 Skin striae Diseases 0.000 description 1
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 230000003190 augmentative effect Effects 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000005388 borosilicate glass Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 229910001431 copper ion Inorganic materials 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 238000003280 down draw process Methods 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910001512 metal fluoride Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000007500 overflow downdraw method Methods 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- XLUBVTJUEUUZMR-UHFFFAOYSA-B silicon(4+);tetraphosphate Chemical compound [Si+4].[Si+4].[Si+4].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O XLUBVTJUEUUZMR-UHFFFAOYSA-B 0.000 description 1
- 239000005361 soda-lime glass Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
- C03C17/22—Surface treatment of glass, not in the form of fibres or filaments, by coating with other inorganic material
- C03C17/23—Oxides
- C03C17/245—Oxides by deposition from the vapour phase
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/12—Silica-free oxide glass compositions
- C03C3/16—Silica-free oxide glass compositions containing phosphorus
- C03C3/17—Silica-free oxide glass compositions containing phosphorus containing aluminium or beryllium
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
- G02B1/11—Anti-reflection coatings
- G02B1/113—Anti-reflection coatings using inorganic layer materials only
- G02B1/115—Multilayers
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/20—Filters
- G02B5/22—Absorbing filters
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/20—Filters
- G02B5/26—Reflecting filters
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/20—Filters
- G02B5/28—Interference filters
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B11/00—Filters or other obturators specially adapted for photographic purposes
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Optics & Photonics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Optical Filters (AREA)
Abstract
An optical filter, the optical filter comprising: a pair of light-transmitting surfaces opposite in the plate thickness direction; and an outer peripheral surface extending from the pair of light-transmitting surfaces in the plate thickness direction. The optical filter is characterized by comprising a glass plate and a protective film covering the glass plate. The protective film forms the pair of light-transmitting surfaces and the outer peripheral surface. The ridge line portion forming the boundary between the light-transmitting surface and the outer peripheral surface has a curved surface shape. The ridge portion has a plurality of concave portions. In the ridge portion, a minimum value of a radius of curvature of a bottom surface of the concave portion existing on an arbitrary line segment having a length of 200 μm along an outer periphery of the light-transmitting surface is 5 μm or more.
Description
Technical Field
The present invention relates to a filter and a near infrared cut filter used in an optical device such as a camera.
Background
In recent years, wearable devices typified by smart phones, motion cameras, VR (virtual reality)/AR (augmented reality) devices are becoming popular. It is envisaged that these devices will be used not only in normal environments but also in harsh environments such as in water or in high temperature and high humidity atmospheres such as in summer. Therefore, high durability is required for the optical filters mounted in these devices.
Examples of the filter include a cover glass hermetically sealing the imaging element, an infrared cut filter for adjusting the visual sensitivity of the camera, a cover glass provided in a camera window of the device, and the like.
For example, an infrared cut filter that adjusts the visual sensitivity of a camera often uses a phosphate glass containing copper ions. However, it is known that the durability of phosphate glass is low. Specifically, in a high-temperature and high-humidity atmosphere, phosphate glass breaks the phosphate network structure in the glass due to moisture in the atmosphere, and a phenomenon occurs in which liquid phosphoric acid dissolves out from the glass surface. The eluted phosphoric acid reacts with the glass, or the portion where the phosphoric acid network is lost is crystallized, and the like, whereby the glass surface is deteriorated.
In order to solve such problems, for example, patent document 1 discloses a filter in which an alumina thin film is provided on the surface of a phosphate glass, thereby suppressing the deterioration of the glass.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 4-139035
Disclosure of Invention
Problems to be solved by the invention
The filter described in patent document 1 has a light-transmitting surface (main surface) of glass provided with an alumina film protected, but the alumina film is not present on the outer peripheral surface of the filter. Therefore, in a high-temperature and high-humidity atmosphere, the deterioration of the glass starts from the outer peripheral surface of the filter, and the deterioration proceeds in the adhesion portion between the glass and the alumina thin film, and there is a concern that the adhesion of both is reduced and the alumina thin film is peeled off.
An object of one embodiment of the present invention is to provide a filter having high durability under a high-temperature and high-humidity atmosphere.
Means for solving the problems
In one embodiment of the filter of the present invention, the filter includes: a pair of light-transmitting surfaces opposite in the plate thickness direction; and an outer peripheral surface extending from the pair of light-transmitting surfaces in the plate thickness direction. The optical filter is characterized by comprising a glass plate and a protective film covering the glass plate, wherein the protective film forms the pair of light-transmitting surfaces and the outer peripheral surface; a ridge line portion forming a boundary between the light-transmitting surface and the outer peripheral surface has a curved surface shape; the ridge portion has a plurality of concave portions; in the ridge portion, a minimum value of a radius of curvature of a bottom surface of the concave portion existing on an arbitrary line segment having a length of 200 μm along an outer periphery of the light-transmitting surface is 5 μm or more.
Effects of the invention
According to one embodiment of the present invention, a filter having high durability in a high-temperature and high-humidity atmosphere can be obtained.
Drawings
Fig. 1 is a top view of a filter according to an embodiment of the present invention.
Fig. 2 is a sectional view of the I-I of fig. 1.
Fig. 3 is an enlarged view of a dotted-line surrounding portion of fig. 2.
Fig. 4 is a schematic view showing a state of a protective film provided on glass in a conventional filter.
Fig. 5 is a schematic view showing a state of a protective film provided on glass in the optical filter according to the embodiment of the present invention.
Fig. 6 is a diagram illustrating definition of physical film thickness of the protective film and a cross-sectional direction of the concave portion.
Fig. 7 is a laser microscopic photograph of the ridge portion of the filter of example 1.
Fig. 8 is a cross-sectional profile of a ridge portion of the filter of example 1.
Fig. 9 is a laser microscopic photograph of the ridge portion of the filter of example 2.
Fig. 10 is a cross-sectional profile of a ridge portion of the filter of example 2.
Fig. 11 is a laser microscopic photograph of the ridge portion of the filter of example 3.
Fig. 12 is a cross-sectional profile of a ridge portion of the filter of example 3.
Detailed Description
Hereinafter, embodiments of the present invention will be described in detail. In the drawings, the same components are denoted by the same reference numerals, and overlapping description is omitted for ease of understanding. In addition, the scale of each member in the drawings sometimes differs from the actual scale. Unless otherwise indicated, the terms "to" in the numerical ranges shown in the present specification mean that the numerical values recited before and after the term "to" are defined as a lower limit value and an upper limit value.
The filter 1 according to the embodiment of the present invention will be described. Fig. 1 is a plan view of a filter 1 according to the present embodiment, and fig. 2 is a sectional view of fig. 1 taken along line I-I. Fig. 3 is an enlarged view of a dotted-line surrounding portion of fig. 2. As shown in fig. 1 to 3, the filter 1 of the present embodiment includes: a pair of light-transmitting surfaces 3a, 3b opposite in the plate thickness direction; and an outer peripheral surface 4 extending in the plate thickness direction from the pair of light-transmitting surfaces 3a, 3 b. The optical filter 1 includes: a glass plate 2 and a protective film 6 covering the glass plate 2. The protective film 6 forms a pair of light-transmitting surfaces 3a, 3b and an outer peripheral surface 4.
The shape of the filter 1 in plan view is not particularly limited, and may include a straight line portion, a curved line portion, or the like, and may be configured only by a curved line such as a circle or an ellipse, in addition to a rectangular shape. The filter 1 preferably has a curved portion in a plan view. For example, the filter 1 is an approximate quadrangle having circular arcs (curved portions) at four corners in a plan view. The light-transmitting surface 3a becomes a surface (upper surface) of the filter 1, and the light-transmitting surface 3b opposite to the light-transmitting surface 3a becomes a back surface (lower surface) of the filter 1.
The ridge line portion 5 forming the boundary between each light-transmitting surface 3a, 3b and the outer peripheral surface 4 of the filter 1 has a curved surface shape. Since the ridge line portion 5 has a curved surface shape, and the protective film 6 is formed as a continuous film that extends over the light-transmitting surfaces 3a and 3b, the ridge line portion 5, and the outer peripheral surface 4, there is no gap for moisture to enter, and therefore, the adhesion between the glass plate 2 and the protective film 6 can be maintained even under a high-temperature and high-humidity atmosphere. In particular, the ridge line portion 5 is preferably a curved surface shape in which the light-transmitting surfaces 3a and 3b are continuously connected to the outer peripheral surface 4 without any level difference. This can more effectively maintain the adhesion between the glass plate 2 and the protective film 6. In addition, the filter 1 may be subjected to bending stress or impact during manufacturing process, transportation, assembly into equipment, use of equipment, or the like. By forming the ridge line portion 5 into a curved surface shape, even when bending stress acts on the filter 1, cracking can be suppressed.
Fig. 4 is a schematic view showing a state of a protective film provided on glass in a conventional filter, fig. 5 is a schematic view showing a state of a protective film provided on glass in a filter according to an embodiment of the present invention, and fig. 6 is a diagram illustrating definition of physical film thickness of a protective film and a sectional direction of a concave portion. As shown in fig. 5, the ridge line portion 5 of the filter 1 has a plurality of concave portions 7. The recess includes the following shape: accurately cutting the ball or the elliptic ball into a half shape; the approximate sphere or the approximate ellipse sphere is cut off in a manner not passing through the center. In a cross-sectional view, the recess 7 may comprise a straight line in addition to the bottom surface. In the ridge portion 5, the minimum value of the radius of curvature of the bottom surface of the concave portion 7, which is present on an arbitrary line segment having a length of 200 μm along the outer periphery of the light-transmitting surfaces 3a, 3b, is 5 μm or more. The minimum value of the radius of curvature is measured here by means of a section. The cross section is not a cross section with the outer Zhou Zhengjiao of the light-transmitting surfaces 3a, 3b, but a cross section along the outer periphery of the light-transmitting surfaces 3a, 3b, and is a cross section of a line segment including the connection point X3a and the point Z3a shown in fig. 6 or a cross section of a line segment including the connection point X3b and the point Z3b shown in fig. 6. In other words, the cross section is a plane including the point X3a and forming an angle of 45 ° with the light-transmitting surface 3a or a plane including the point X3b and forming an angle of 45 ° with the light-transmitting surface 3b. The point at which the virtual line M3a including the light-transmitting surface 3a intersects with the virtual line N including the outer peripheral surface 4 is referred to as a point X3a, and the point at which the virtual line M3b including the light-transmitting surface 3b intersects with the virtual line N including the outer peripheral surface 4 is referred to as a point X3b. Further, a point at which the virtual line M3a contacts the light-transmitting surface 3a when the virtual line M3a is oriented toward the light-transmitting surface 3a from the point X3a is set as a point Y3a. Similarly, a point at which the virtual line M3b contacts the light-transmitting surface 3b when the virtual line M3b is oriented toward the light-transmitting surface 3b from the point X3b is referred to as a point Y3b. Then, the intersection point between the line segment, which is obtained by rotating the virtual line M3a by 45 ° in the direction of the light-transmitting surface 3b with respect to the point X3a as the rotation center, and the line segment connecting the point Y3a and the point Y3b is set as a point Z3a. Similarly, the intersection point between the line segment, which is obtained by rotating the virtual line M3b by 45 ° in the direction of the light-transmitting surface 3a with respect to the point X3b as the rotation center, and the line segment connecting the point Y3a and the point Y3b is set as the point Z3b.
The ridge line portion 5 passing through the filter 1 has a plurality of concave portions 7, and in the ridge line portion 5, the minimum value of the radius of curvature of the bottom surface of the concave portion 7 existing on any line segment of 200 μm in length along the outer periphery of the light-transmitting surfaces 3a, 3b is 5 μm or more, whereby high adhesion between the glass plate 2 and the protective film 6 can be obtained particularly at high temperature and high humidity. Therefore, the filter according to the present embodiment can suppress deterioration of optical characteristics at high temperature and high humidity, and can obtain high durability. The mechanism is presumed as follows.
The glass plate for the optical filter is usually in a state in which the light-transmitting surface is optically polished and the surface roughness is very small. In contrast, the surface of the outer peripheral surface or the ridge line portion is generally rougher than the light-transmitting surface, and scratches are present. For example, when a ridge portion of a glass plate is processed by a grinding stone, many fine and deep scratches are present in the ridge portion.
If the ridge portion of the glass plate having the deep scratch is covered with the protective film, the protective film does not reach the tip of the deep scratch 8, and thus the entire surface of the scratch cannot be reliably protected, as shown in fig. 4. When such a filter is exposed to a high-temperature and high-humidity atmosphere, moisture in the atmosphere tends to aggregate at the tip of the deep scratch 8. The aggregated moisture deteriorates the glass plate from the glass at the front end of the deep scratch without the protective film. Further, the deterioration spreads to the glass plate, thereby deteriorating the adhesion between the glass plate and the protective film, and further deteriorating the optical characteristics of the filter.
That is, even if a protective film such as an alumina film is provided on the outer peripheral surface of the glass plate, a minute gap may be generated in the protective film depending on the surface state of the glass plate in contact with the protective film, and the durability of the filter may be deteriorated due to the gap.
In the filter 1 of the present embodiment, as shown in fig. 5, the protective film 6 reaches the bottom surface of the concave portion 7, and the entire surface of the concave portion 7, that is, the ridge portion 5 can be reliably covered with the protective film 6. Accordingly, even when the optical filter is exposed to a high-temperature and high-humidity atmosphere, moisture which is a factor of deteriorating the glass plate does not directly contact the glass plate, and deterioration of the optical characteristics of the optical filter can be suppressed.
In the filter 1 of the present embodiment, the protective film 6 is easily attached to the bottom surface of the recess 7, and deterioration of the filter 1 can be suppressed. When the minimum value of the radius of curvature of the bottom surface of the concave portion 7 is 5 μm or more, the protective film 6 can be sufficiently attached to the bottom surface of the concave portion 7, and deterioration of the glass plate can be suppressed. The minimum value of the radius of curvature of the bottom surface of the concave portion 7 is more preferably 5 μm to 200 μm. When the minimum value of the radius of curvature of the bottom surface of the concave portion 7 is more than 200 μm, the manufacturing time for forming the concave portion 7 is long, and the manufacturing cost of the optical filter 1 may increase. The minimum value of the radius of curvature of the bottom surface of the concave portion 7 is more preferably in the range of 6 μm to 175 μm, still more preferably 7 μm to 150 μm, still more preferably 9 μm to 100 μm, and most preferably 10 μm to 90 μm. The minimum value of the curvature radius of the bottom surface of the concave portion 7 is a minimum curvature radius obtained by confirming each of the curvature radii of the plurality of concave portions 7 existing on an arbitrary line segment having a length of 200 μm of the concave portion 7 including the ridge portion 5. The radius of curvature of the bottom surface of the concave portion 7 and the total number of the tip portions in the present embodiment are measured in a state where the glass plate 2 is covered with the protective film 6.
In the filter 1 of the present embodiment, the total number of the tips present in any line segment having a length of 200 μm along the outer periphery of the light-transmitting surfaces 3a, 3b in the ridge line portion 5 is preferably 50 or less. Thus, the thickness of the protective film 6 in the ridge line portion 5 is not uneven, and occurrence of film defects such as pinholes can be suppressed. The total number of the tip portions is more preferably 2 to 50. When the total number of the tip portions is more than 50, there is a possibility that film defects of the protective film 6 may occur, which is not preferable. In addition, when the total number of the tip portions is less than 2, the manufacturing time for forming the ridge line portion 5 is long, and the manufacturing cost of the optical filter 1 may increase. The total number of the tips of the ridge line portion 5 present on any line segment having a length of 200 μm along the outer periphery of the light-transmitting surfaces 3a, 3b is more preferably in the range of 2 to 45, still more preferably 2 to 40, still more preferably 2 to 30, and most preferably 2 to 25. In the present embodiment, the tip is defined as the apex of a trailing-leaf linear curve in the cross-sectional profile when surface irregularities of the region including the concave portion 7 are measured.
The protective film 6 has a function of preventing the glass plate 2 from being in direct contact with moisture in a high-temperature and high-humidity atmosphere by covering the surface of the glass plate 2. Therefore, the protective film 6 can suppress deterioration of the optical characteristics of the filter 1.
The protective film 6 is preferably one or more dielectric films. The dielectric film is, for example, a film containing a metal oxide, a metal fluoride, or the like, and the film has high moisture barrier properties (particularly, moisture entering from the vertical direction) under a high-temperature and high-humidity atmosphere and is hardly degraded by the protective film 6 itself. Further, since the dielectric film has high light transmittance, at least the optical characteristics of the filter are not deteriorated. The number of layers of the protective film 6 is more preferably 1 to 100, still more preferably 1 to 50.
The protective film 6 preferably contains Al 2O3.Al2O3 having a characteristic that dissociation energy of Al atoms and O atoms is very high, that is, both form a strong bond. Al 2O3 is considered to be amorphous after forming into the glass plate 2, and it is considered that each atom is strongly attracted to each other and adopts a random packing structure, so that a very strong and dense structure is formed. It is presumed that the water molecules can thereby be prevented from entering the glass plate 2 as the protective film 6.
The filter 1 of the present embodiment preferably includes Al 2O3 in the protective film 6 and Al (aluminum) component in the glass plate 2. In the glass plate, the Al component is a glass network structure constituent. When the protective film 6 containing Al 2O3 is formed on the glass plate 2, a covalent bond is formed between the Al component as the glass network structure of the glass plate 2 and Al 2O3 of the protective film 6, and the adhesion of the protective film 6 to the glass plate 2 becomes firm. Therefore, deterioration of the optical characteristics of the filter 1 under a high-temperature and high-humidity atmosphere can be further suppressed.
In the filter 1 of the present embodiment, when the physical film thickness of the protective film 6 on the light-transmitting surfaces 3a and 3B is a and the physical film thickness of the protective film 6 on the ridge portion 5 is B, the following relational expression (1) is preferably satisfied:
1.0<A/B<2000……(1)。
In the above range, the moisture blocking effect of the protective film 6 in the ridge line portion 5 can be improved. When a/B is less than 2000, the difference between the physical film thickness a of the protective film 6 of the light-transmitting surfaces 3a, 3B and the physical film thickness B of the protective film 6 of the ridge line portion 5 is small, and the ridge line portion 5 can be sufficiently protected, so that deterioration of the optical characteristics of the optical filter 1 can be further suppressed. In addition, when a/B is greater than 1.0, productivity for forming the protective film 6 on the ridge line portion 5 can be improved, and manufacturing cost of the filter 1 can be reduced.
The upper limit of a/B is preferably 1500 or less, more preferably 1000 or less, and still more preferably 500 or less. The lower limit of a/B is preferably 2 or more, more preferably 5 or more, and still more preferably 10 or more.
The physical film thickness of the protective film 6 in the ridge line portion 5 is defined as follows in the present embodiment. As shown in fig. 6, in the cross-sectional view of the filter, a point at which a virtual line M3a including the light-transmitting surface 3a intersects a virtual line N including the outer peripheral surface 4 is set as a point X3a, and a point at which a virtual line M3b including the light-transmitting surface 3b intersects a virtual line N including the outer peripheral surface 4 is set as a point X3b. Further, a point at which the virtual line M3a contacts the light-transmitting surface 3a when the virtual line M3a is oriented toward the light-transmitting surface 3a from the point X3a is set as a point Y3a. Similarly, a point at which the virtual line M3b contacts the light-transmitting surface 3b when the virtual line M3b is oriented toward the light-transmitting surface 3b from the point X3b is referred to as a point Y3b. Then, the intersection point between the line segment, which is obtained by rotating the virtual line M3a by 45 ° in the direction of the light-transmitting surface 3b with respect to the point X3a as the rotation center, and the line segment connecting the point Y3a and the point Y3b is set as a point Z3a. Similarly, the intersection point between the line segment, which is obtained by rotating the virtual line M3b by 45 ° in the direction of the light-transmitting surface 3a with respect to the point X3b as the rotation center, and the line segment connecting the point Y3a and the point Y3b is set as the point Z3b. On the straight line connecting the point X3a and the point Z3a or the straight line connecting the point X3b and the point Z3b, the width of the protective film 6 existing in the direction of the straight line is defined as the physical film thickness of the protective film 6 in the ridge line portion 5. When the outer peripheral surface 4 does not have a plane (a straight line portion in a cross-sectional view), a line perpendicular to the virtual line M and passing through the outermost portion of the outer peripheral surface 4 is defined as a virtual line N including the outer peripheral surface 4.
The physical film thickness of the protective film 6 in the ridge line portion 5 is preferably 10nm or more. This can reliably protect the ridge 5 of the filter 1. The physical film thickness of the protective film 6 in the ridge line portion 5 is preferably 15nm to 15. Mu.m, more preferably 20nm to 10. Mu.m, and most preferably 25nm to 7. Mu.m.
The protective film 6 preferably has any one of the functions of antireflection of visible light, reflection of infrared light, reflection of ultraviolet light, reflection of infrared light, and reflection of ultraviolet light. Thus, the protective film 6 has an optical function, and thus, it is not necessary to provide a functional film different from the protective film 6 separately on the optical filter 1, and the manufacturing cost of the optical filter 1 can be reduced.
The protective film 6 can be formed by, for example, sputtering, vacuum deposition, ion beam, ion plating, CVD, or the like. According to these methods, the physical film thickness of the protective film 6 provided on the surface of the glass plate 2 can be controlled with high accuracy. In addition, the sputtering method and the ion plating method are so-called plasma atmosphere treatment, and therefore, the adhesion of the protective film 6 to the glass plate 2 can be improved, which is preferable. Further, since the protective film 6 itself can be formed as a dense film, a sputtering method or an ion plating method is preferably used from the viewpoint of blocking the glass plate 2 from moisture.
In order to obtain desired optical characteristics, the filter 1 of the present embodiment may include, in addition to the protective film 6, a dielectric multilayer film that reflects light of a specific wavelength, and an absorption film containing a metal oxide or a pigment that reflects light of a specific wavelength.
The glass plate 2 of the filter 1 of the present embodiment is preferably any one of phosphate glass, fluorophosphate glass, thiophosphate glass, and silicophosphate glass. These glasses can obtain excellent optical characteristics by containing an appropriate transition metal component according to desired optical characteristics.
Specifically, in a filter required to shield near infrared light, cu ions and Fe ions having an absorption band in this region are often used, and it is preferable to use a phosphate glass which is more likely to significantly exhibit near infrared absorption of these ions.
As the phosphate glass, a fluorophosphate glass containing fluorine, a sulfur phosphate glass containing sulfur, and a silicon phosphate glass containing silicon can be suitably used.
As the glass plate 2, borosilicate glass, soda lime glass, high silicon glass, or the like can be used, for example. The size, thickness, shape, etc. of the glass plate 2 are appropriately selected according to the use of the filter 1, etc. The thickness of the glass plate 2 is preferably 0.05mm to 0.5mm, more preferably 0.05mm to 0.3mm, because the thickness of the device is reduced when the filter 1 is used in the device.
The glass plate 2 of the filter 1 of the present embodiment contains P 2O5、Al2O3, R 'O (wherein R' O represents one or more selected from MgO, caO, srO, baO and ZnO), and Fe 2O3 as essential components, and preferably contains 0.1 to 35% of Fe 2O3 in terms of mol% based on oxide, with respect to the content of Fe 2O3. Thereby, the filter 1 can have a near infrared ray shielding function.
P 2O5 is a main component for forming glass (glass forming oxide), and is an essential component for improving the near infrared cut-off property.
Al 2O3 is a main component for forming glass (glass forming oxide), and is an essential component for improving weather resistance, strength of glass, and the like.
R 'O (wherein R' O represents at least one selected from MgO, caO, srO, baO and ZnO) is an essential component for lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, improving the strength of glass, and the like.
Fe 2O3 is an essential component for near infrared ray cut-off. The content of Fe 2O3 is preferably 0.1% or more and 35% or less. When the content is less than 0.1%, the effect cannot be sufficiently obtained when the thickness of the glass is made thin, and when the content is more than 35%, the transmittance of light in the visible light region is lowered, so that it is not preferable. The content of Fe 2O3 is preferably 0.5 to 35%, more preferably 1.0 to 35%, and even more preferably 2.0 to 35%.
In the present embodiment, fe 2O3 is a total amount of all Fe (iron) components converted to Fe 2O3.
The glass plate 2 of the filter 1 of the present embodiment preferably contains, in mol% based on oxides:
P2O5：25％～75％；
Al2O3：2.5％～22％；
R' O:0.1% -35% (wherein R' O represents the total amount of MgO, caO, srO, baO and ZnO);
Fe2O3：0.1％～35％；
R 2 O:0% -20% (wherein R 2 O represents the total amount of Li 2O、Na2 O and K 2 O).
P 2O5 is a main component for forming glass, and is an essential component for improving the cut-off property in the near infrared region. However, when the content of P 2O5 is less than 25%, the effect of blocking light in the near infrared region cannot be sufficiently obtained, and further, the transmittance of light in the visible region is lowered due to an increase in the ratio of Fe 3+ in the iron component in the glass, which is not preferable. If the content exceeds 75%, the glass becomes unstable and the weather resistance is lowered, which is not preferable. The content of P 2O5 is more preferably 30 to 73%, still more preferably 35 to 70%. More preferably, the content is 40 to 65%.
Al 2O3 is a main component for forming glass, and is an essential component for improving weather resistance of glass, improving strength of glass, and the like. However, when the content is less than 2.5%, the effect cannot be sufficiently obtained, and when the content is more than 22%, problems such as unstable glass and reduced infrared ray cut-off are caused, which is not preferable. The content of Al 2O3 is more preferably 3% to 20%, and still more preferably 4% to 18%.
R "O (wherein R" O represents the total amount of MgO, caO, srO, baO and ZnO) is an essential component for lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, improving the strength of glass, and the like. However, when the content is less than 0.1%, the effect cannot be sufficiently obtained, and when the content is more than 35%, problems such as unstable glass, reduced infrared ray cut-off, and reduced strength of glass are caused, which is not preferable. The content of R' O is more preferably 1 to 33%, still more preferably 1.5 to 32%. Even more preferably 2% to 30%, and most preferably 2.5% to 29%.
MgO is a component for lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, and improving the strength of glass. When MgO is contained, the content is preferably 0.5 to 15%. When the content is less than 0.5%, the effect cannot be sufficiently obtained, and when the content is more than 15%, the glass becomes unstable, so that it is not preferable. The MgO content is more preferably 1.0% to 13%, and still more preferably 1.5% to 10%.
CaO is a component for lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, improving the strength of glass, and the like. When CaO is contained, the content is preferably 0.1 to 10%. When the content is less than 0.1%, the effect cannot be sufficiently obtained, and when the content is more than 10%, the glass becomes unstable, so that it is not preferable. The CaO content is more preferably 0.3 to 8%, and still more preferably 0.5 to 6%.
SrO is a component for lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, and the like. When SrO is contained, the content is preferably 0.1% to 10%. When the content is less than 0.1%, the effect cannot be sufficiently obtained, and when the content is more than 10%, the glass becomes unstable, so that it is not preferable. The content of SrO is more preferably 0.3% to 8%, and still more preferably 0.5% to 8%.
BaO is a component for lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, and the like. When BaO is contained, the content is preferably 0.1 to 10%. When the content is less than 0.1%, the effect cannot be sufficiently obtained, and when the content is more than 10%, the glass becomes unstable, so that it is not preferable. The content of BaO is more preferably 0.5% to 8%, and still more preferably 1% to 6%.
ZnO has the effects of lowering the melting temperature of glass, lowering the liquidus temperature of glass, and the like. In the case of ZnO, the content is preferably 0.5 to 20%. When the content is less than 0.5%, the effect cannot be sufficiently obtained, and when the content is more than 20%, the meltability of the glass becomes poor, so that it is not preferable. The content of ZnO is more preferably 1% to 18%, and still more preferably 1.5% to 17%.
Fe 2O3 is an essential component for near infrared ray cut-off. The content of Fe 2O3 is preferably 0.1% -35%. When the content is less than 0.1%, the effect cannot be sufficiently obtained when the thickness of the glass is made thin, and when the content is 35% or more, the transmittance of light in the visible light region is lowered, so that it is not preferable. The content of Fe 2O3 is preferably 1% to 35%, more preferably 3% to 35%, and even more preferably 5% to 35%.
R 2 O (wherein R 2 O represents the total amount of Li 2O、Na2 O and K 2 O) is a component for increasing the thermal expansion coefficient of glass, lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, and the like. The content of R 2 O is preferably 0% to 20%. When the content is more than 20%, the glass becomes unstable, and is not preferable. The content of R 2 O is more preferably 0.5% to 18%, still more preferably 1.0% to 16%, still more preferably 1.5% to 15%.
Li 2 O is a component for lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, and the like. The content of Li 2 O is preferably 0% to 10%. When the content is more than 10%, the glass becomes unstable, and is not preferable. The content of Li 2 O is more preferably 0.5% to 8%, and still more preferably 1% to 7%.
Na 2 O is a component for lowering the melting temperature of glass, lowering the liquidus temperature of glass, stabilizing glass, and the like. The content of Na 2 O is preferably 0% to 20%. When the content is more than 20%, the glass becomes unstable, and is not preferable. The content of Na 2 O is more preferably 0.7% to 18%, and still more preferably 1% to 16%.
K 2 O is a component having effects of lowering the melting temperature of glass, lowering the liquidus temperature of glass, and the like. The content of K 2 O is preferably 0% to 15%. When the content is more than 15%, the glass becomes unstable, and is not preferable. The content of K 2 O is more preferably 0.5 to 13%, still more preferably 0.7 to 10%.
B 2O3 may be contained in a range of 10% or less for stabilizing the glass. If the content exceeds 10%, weather resistance may be deteriorated or the melting temperature may be too high, which is not preferable. The content of B 2O3 is preferably 0% to 9%, more preferably 0% to 8.5%, even more preferably 0% to 8%, and most preferably 0% to 7.5%.
The glass plate 2 of the filter 1 of the present embodiment may contain CuO instead of Fe 2O3. CuO is a component for near infrared ray cut-off. The content of CuO is preferably 0.1% or more and 35% or less. When the content is less than 0.1%, the effect cannot be sufficiently obtained when the thickness of the glass is made thin, and when the content is more than 35%, the transmittance of light in the visible light region is lowered, so that it is not preferable. The content of CuO is preferably 0.5% to 35%, more preferably 1.0% to 35%, and even more preferably 2.0% to 35%.
The CuO in the present embodiment means that the total amount of all Cu (copper) components is converted into CuO.
The glass plate 2 of the filter 1 of the present embodiment preferably contains 5 to 50 mol% or less of F - (fluoride ion) in terms of anion ratio. That is, the ratio of F - to total anions is preferably 5 to 50 mol%.
If F - is less than 5%, the effect cannot be sufficiently obtained, and if F - is more than 50%, mechanical properties such as strength, hardness, elastic modulus and the like may be lowered, volatility may be increased and striae may be increased, which is not preferable. The content of F - is preferably 7% to 50%, more preferably 9% to 50%.
The glass plate 2 may contain other components such as Cl, br, I, etc. as optional anionic components within a range that does not impair the effects of the present invention. The total content of these components is preferably 5% or less.
The glass plate 2 preferably contains one or more of Li 2O、Na2O、K2 O components as an alkali metal component. These components are glass network modifying components, and when these components are contained, glass network bonds are cut off, and the glass network bonds are weakened, so that, for example, the concave portions 7 can be easily formed in the ridge line portions 5 by an etching process.
The concentration of Li 2O、Na2O、K2 O at a depth of 10nm to 100nm from the surface of the ridge line portion 5 of the glass plate 2 on the line segment connecting the point X3a and the point Z3a or the line segment connecting the point X3b and the point Z3b in FIG. 6 is preferably 90% or less of the concentration of these components at the point Z3a or the point Z3b shown in FIG. 6. As a result, the rate of the end of the glass network structure on the surface of the ridge line portion 5 becoming a non-bonded state in which no glass network modifying component is present increases, and therefore, a new covalent bond is easily formed with the component of the protective film 6 at the time of film formation, and the adhesion of the protective film 6 to the glass plate 2 becomes strong. Therefore, deterioration of the optical characteristics of the filter 1 under a high-temperature and high-humidity atmosphere can be further suppressed.
The filter 1 of the present embodiment can be manufactured as follows, for example. First, raw materials are weighed and mixed so that the obtained glass falls within a predetermined composition range (mixing step). The raw material mixture is contained in a crucible and heated and melted in an electric furnace at a temperature of 700 to 1400 ℃. The melted glass is sufficiently stirred and clarified, and then cast into a mold, and cut and ground to be formed into a flat plate shape having a predetermined thickness (a step of forming a plate-like glass). The ridge line portion 5, which is the boundary between the light-transmitting surfaces 3a and 3b of the molded glass and the outer peripheral surface 4, is cut with a grinding stone (chamfering step). After optically polishing the light-transmitting surfaces 3a and 3b of the glass, the glass subjected to chamfering is immersed in an etching solution, and then the glass is processed so that the ridge line portion 5 has a curved shape (etching step). The etched glass is washed to obtain a glass plate (washing step). The production process is not limited to the above-described production process as long as a desired glass plate is obtained. For example, as a method for obtaining a plate-shaped glass, a known production method such as a float method, a downdraw method (e.g., overflow downdraw method), a re-pulling method, a press molding method, or a draw-up method can be used.
The etching step uses an etching solution. As the etching liquid, HCl, HNO 3, and HF can be used if it is an acid solution. In addition, if the alkali solution is an alkali solution, KOH, naOH or the like can be used. The etching solution may be appropriately used depending on the glass composition and the desired shape of the ridge line portion 5, and is not limited to the above etching solution.
The protective film 6 is formed on the ridge line portion 5 of the glass plate 2 by the above-described film forming method (sputtering method, vacuum deposition method, ion beam method, ion plating method, CVD method, etc.) (film forming step). In forming the protective film 6, it is preferable to consider a method of holding the glass plate 2 in the film forming apparatus in order to form the protective film 6 not only on the ridge line portion 5 of the glass plate 2 but also on the outer peripheral surface 4.
The filter 1 of the present embodiment can be used as a filter for a projection display device, a solid-state imaging device, an optical recording/reproducing device, an optical communication device, an optical sensor device, or the like, for example. In particular, the near infrared cut filter can be suitably used for a solid-state imaging device. The filter 1 of the present embodiment can be used not only for the above-described applications but also for other applications.
Examples
Hereinafter, examples are shown to more specifically explain the embodiments, but the embodiments are not limited to these examples. Examples 1 and 3 are examples, and example 2 is a comparative example.
< Example 1>
[ Production of optical Filter ]
The glass plate was produced by the following method. A glass substrate having a predetermined composition (P 2O5 mol%, al 2O3 mol%, K 2 O1 mol%, baO+ZnO 11 mol%, and Fe 2O3 mol%) was prepared as a glass component after melt molding. Next, the front and back surfaces were optically polished to obtain glass having a plate thickness of 0.2 mm. Then, the glass was cut into a size of 20mm×20mm by a cutter wheel. Then, the end face of the glass exposed by cutting was chamfered by a diamond grinding wheel. Then, a plate-like glass was etched under the conditions (treatment solution: etching solution containing 3 wt% KOH at a temperature of 30 ℃ C., etching time: 80 minutes), to obtain a glass plate.
Next, an Al 2O3 film was formed on the surface of the glass plate by a vacuum evaporation method, thereby obtaining a filter. The film formation was performed such that the physical film thickness of the Al 2O3 film on the light-transmitting surface of the filter was 150nm and the physical film thickness of Al 2O3 on the ridge line portion was 10nm or more.
< Example 2>
[ Production of optical Filter ]
The same operations as in example 1 were performed except that etching of glass was not performed in example 1, and a filter was obtained.
< Example 3>
[ Production of optical Filter ]
The glass plate was produced by the following method. A glass substrate having a predetermined composition (P 2O5 mol%, al 2O3 mol%, na 2 O6 mol%, K 2 O11 mol%, and CuO 12 mol%) was prepared as a glass component after melt molding. Next, the front and back surfaces were optically polished to obtain glass having a plate thickness of 0.28 mm. Then, the glass was cut into a size of 20mm×20mm by a cutter wheel. Then, the end face of the glass exposed by cutting was chamfered by a diamond grinding wheel. Then, a plate-like glass was subjected to etching under the conditions (treatment solution: etching solution containing 10 wt% KOH at a temperature of 40 ℃ C., etching time: 3 hours), thereby obtaining a glass plate.
Next, an Al 2O3 film was formed on the surface of the glass plate by a vacuum evaporation method, thereby obtaining a filter. The film formation was performed such that the physical film thickness of the Al 2O3 film on the light-transmitting surface of the filter was 150nm and the physical film thickness of Al 2O3 on the ridge line portion was 10nm or more.
The filters of examples 1,2 and 3 were evaluated for ridge portions by the following method. The surface shape of the ridge line portion of the filter was measured using a laser microscope (shape measuring laser microscope VKX-1000, manufactured by ken corporation). Fig. 7 and 8 show a laser micrograph of the ridge line portion and a cross-sectional profile of example 1. Fig. 9 and 10 show a laser micrograph of the ridge line portion and a cross-sectional profile of example 2. Fig. 11 and 12 show a laser micrograph of the ridge line portion and a cross-sectional profile of example 3. In the laser photomicrographs of fig. 7 and 11, the crater-shaped concave portion is as if it were viewed in a plan view.
< Radius of curvature of bottom surface of concave portion >
The radius of curvature of the bottom surface of the approximately hemispherical concave portion is measured as follows. The surface shape of the ridge portion of the filter was measured using the laser microscope. Specifically, an arbitrary line segment having a length of 200 μm along the outer periphery of the light-transmitting surface was designated in the ridge portion, and the cross-sectional profile thereof was measured. Using this cross-sectional profile, any 3 points including the bottom surface in a concave curve are specified, and the radius of a circle passing through the 3 points is defined as the radius of curvature of the concave portion. The radii of curvature are measured for each of the concave curves present in the cross-sectional profile, and the minimum value thereof is obtained.
< Total number of tips >
The above-described cross-sectional profile was used, and the apex of a vining line curve on a line segment having a distance of 200 μm between 2 points in the region including the concave portion was used as the tip, and the total number thereof was counted. In the cross-sectional profile of fig. 8, the position indicated by the downward arrow is regarded as a tip.
< Durability of Filter at high temperature and high humidity >
In a high accelerated lifetime test apparatus manufactured by espek, the filters of examples 1 and 2 were left at 121 ℃ for 36 hours under 2 atmospheres, and the degradation state of the removed filters was observed by a laser microscope. The filter in which the glass plate and the protective film were peeled off at the ridge line portion of the filter was designated as B, and the filter in which no peeling was generated was designated as a.
The evaluation results of examples 1 and 2 are shown in table 1. As shown in the cross-sectional profile of fig. 10, the filter of example 2 does not have a recess having a nearly hemispherical shape, and therefore, the measurement of the radius of curvature and the counting of the total number of tips (indicated by "-" in table 1) cannot be performed.
TABLE 1
In a constant temperature and humidity machine manufactured by espek, the filter of example 3 was left at a temperature of 85 ℃ and a relative humidity of 85% for 500 hours, and the degradation state of the filter after removal was observed by a laser microscope. The filter in which the glass plate and the protective film were peeled off at the ridge line portion of the filter was designated as B, and the filter in which no peeling was generated was designated as a.
The evaluation results of example 3 are shown in table 2.
TABLE 2
< Physical film thickness >
The cross section of the filter was observed by FE-SEM (manufactured by Hitachi Kagaku Co., ltd., field emission scanning electron microscope: regulus 8100). The physical film thickness of the Al 2O3 film on the light-transmitting surface of the filter of example 1 was 150nm, the physical film thickness of the Al 2O3 film on the ridge portion 5 was 100nm, and the physical film thickness of the Al 2O3 film on the outer peripheral surface 4 was 50nm. The physical film thickness of the Al 2O3 film in each section of the filter of example 3 was the same as that of example 1.
As shown in tables 1 and 2, it is understood that the filters of examples 1 and 3 obtained filters in which peeling of the glass plate and the protective film was suppressed even under a high temperature and high humidity atmosphere, as compared with the filter of example 2. This is considered to be because, in the ridge line portions of the filters of examples 1 and 3, the minimum value of the radius of curvature of the bottom surface of the concave portion is 5 μm or more, the total number of the tip portions is 50 or less, and the glass plate and the moisture are reliably blocked by the protective film even under a high-temperature and high-humidity atmosphere.
In contrast, in the ridge portion of the filter of example 2, the protective film did not completely cover the glass plate. Therefore, it is considered that moisture is condensed at the bottom of the scratches of the ridge line portion of the glass plate under a high temperature and high humidity atmosphere, and the glass plate is degraded by contact of the glass plate with the moisture, resulting in peeling of the glass plate and the protective film.
Mode for the invention
The present invention includes the following means.
< Mode 1>
An optical filter, the optical filter comprising: a pair of light-transmitting surfaces opposite in the plate thickness direction; and an outer peripheral surface extending from the pair of light-transmitting surfaces in the plate thickness direction,
The optical filter is characterized in that the optical filter comprises: a glass plate and a protective film covering the glass plate, the protective film forming the pair of light-transmitting surfaces and the outer peripheral surface,
The ridge line part forming the boundary between the light-transmitting surface and the outer peripheral surface has a curved surface shape,
The ridge portion has a plurality of concave portions,
In the ridge portion, a minimum value of a radius of curvature of a bottom surface of the concave portion existing on an arbitrary line segment having a length of 200 μm along an outer periphery of the light-transmitting surface is 5 μm or more.
< Mode 2>
The filter according to claim 1, wherein the total number of tips existing on the arbitrary line segment is 50 or less.
< Mode 3>
The filter according to claim 1 or 2, wherein the ridge line portion continuously connects the light-transmitting surface and the outer peripheral surface without a step.
< Mode 4>
The filter according to any one of claims 1 to 3, wherein the protective film is one or more dielectric films.
< Mode 5>
The filter according to any one of claims 1 to 4, wherein the protective film contains Al 2O3.
< Mode 6>
The filter according to any one of claims 1 to 5, wherein the glass plate contains an Al component.
< Mode 7>
The optical filter according to any one of claims 1 to 6, wherein when a physical film thickness of the protective film on the light-transmitting surface is a and a physical film thickness of the protective film on the ridge line portion is B, the following relational expression (1) is satisfied:
1.0<A/B<2000……(1)。
< mode 8>
The filter according to any one of claims 1 to 7, wherein the physical film thickness of the protective film in the ridge portion is 10nm or more.
< Mode 9>
The filter according to any one of claims 1 to 8, wherein the protective film has any one of a function of antireflection of visible light, reflection of infrared light, reflection of ultraviolet light, reflection of infrared light, and reflection of ultraviolet light.
< Mode 10>
The filter according to any one of claims 1 to 9, wherein an outer shape of the filter in a plan view includes a curved portion.
< Mode 11>
The optical filter according to any one of claims 1 to 10, wherein the glass plate is any one of phosphate glass, fluorophosphate glass, thiophosphate glass, and silicophosphate glass.
< Mode 12>
The optical filter according to claim 11, wherein the glass plate contains P 2O5、Al2O3, R 'O (wherein R' O represents at least one selected from MgO, caO, srO, baO and ZnO) and Fe 2O3,
The content of Fe 2O3 is 0.1-35% based on the mol% of the oxide.
< Mode 13>
The filter according to claim 12, wherein the glass plate contains, in mol% based on oxide:
P2O5：25％～75％；
Al2O3：2.5％～22％；
R' O:0.1% -35% (wherein R' O represents the total amount of MgO, caO, srO, baO and ZnO);
Fe2O3：0.1％～35％；
R 2 O:0% -20% (wherein R 2 O represents the total amount of Li 2O、Na2 O and K 2 O).
< Mode 14>
The filter according to claim 11, wherein the glass plate contains, in mol% based on oxide:
P2O5：25％～75％；
Al2O3：2.5％～22％；
R' O:0.1% -35% (wherein R' O represents the total amount of MgO, caO, srO, baO and ZnO);
R 2 O:0% -20% (wherein R 2 O represents the total amount of Li 2O、Na2 O and K 2 O);
CuO：0.1％～35％。
< mode 15>
The filter according to any one of claims 12 to 14, wherein the glass plate contains 5 to 50 mol% of F-based on an anion ratio.
< Mode 16>
A near infrared cut filter comprising the filter according to any one of modes 1 to 15.
The international application claims priority based on japanese patent application No. 2021-180650, filed on 11/4 of 2021, the entire contents of which are incorporated herein by reference.
Industrial applicability
According to the present invention, a highly durable optical filter can be obtained in which the protective film functions even under a high-temperature and high-humidity atmosphere and deterioration of optical characteristics is suppressed, and therefore, the present invention is particularly useful in applications of optical devices that are supposed to be used in severe environments.
Description of the reference numerals
1. Optical filter
2. Glass plate
3A light-transmitting surface
3B light-transmitting surface
4. An outer peripheral surface
5. Edge line part
6. Protective film
7. Concave part
8. Deep scratch
Claims (16)
1. An optical filter, the optical filter comprising: a pair of light-transmitting surfaces opposite in the plate thickness direction; and an outer peripheral surface extending from the pair of light-transmitting surfaces in the plate thickness direction,
The optical filter is characterized in that,
The optical filter includes a glass plate and a protective film covering the glass plate, the protective film forming the pair of light-transmitting surfaces and the outer peripheral surface,
The ridge line part forming the boundary between the light-transmitting surface and the outer peripheral surface has a curved surface shape,
The ridge portion has a plurality of concave portions,
In the ridge portion, a minimum value of a radius of curvature of a bottom surface of the concave portion existing on an arbitrary line segment having a length of 200 μm along an outer periphery of the light-transmitting surface is 5 μm or more.
2. The filter of claim 1, wherein a total number of tips present on the arbitrary line segment is 50 or less.
3. The filter according to claim 2, wherein the ridge line portion continuously connects the light-transmitting surface and the outer peripheral surface without a step.
4. The filter of claim 3, wherein the protective film is one or more dielectric films.
5. The filter of claim 4, wherein the protective film comprises Al 2O3.
6. The filter according to claim 5, wherein the glass plate contains an Al component.
7. The optical filter according to claim 6, wherein when a physical film thickness of the protective film on the light-transmitting surface is a and a physical film thickness of the protective film on the ridge line portion is B, the following relational expression (1) is satisfied:
1.0<A/B<2000……(1)。
8. the filter according to claim 7, wherein a physical film thickness of the protective film in the ridge portion is 10nm or more.
9. The filter according to claim 8, wherein the protective film has any one of a function of visible light antireflection, infrared reflection, ultraviolet reflection, infrared reflection, and ultraviolet reflection.
10. The filter of claim 9, wherein the filter has a top view profile comprising a curved portion.
11. The filter of claim 10, wherein the glass sheet is any one of phosphate glass, fluorophosphate glass, thiophosphate glass, and silicophosphate glass.
12. The optical filter according to claim 11, wherein the glass plate contains P 2O5、Al2O3, R 'O (wherein R' O represents at least one selected from MgO, caO, srO, baO and ZnO) and Fe 2O3,
The content of Fe 2O3 is 0.1-35% based on the mol% of the oxide.
13. The filter of claim 12, wherein the glass sheet comprises, in mole percent on an oxide basis:
P2O5：25％～75％；
Al2O3：2.5％～22％；
R' O:0.1% -35% (wherein R' O represents the total amount of MgO, caO, srO, baO and ZnO);
Fe2O3：0.1％～35％；
R 2 O:0% -20% (wherein R 2 O represents the total amount of Li 2O、Na2 O and K 2 O).
14. The filter of claim 11, wherein the glass sheet comprises, in mole percent on an oxide basis:
P2O5：25％～75％；
Al2O3：2.5％～22％；
R' O:0.1% -35% (wherein R' O represents the total amount of MgO, caO, srO, baO and ZnO);
R 2 O:0% -20% (wherein R 2 O represents the total amount of Li 2O、Na2 O and K 2 O);
CuO：0.1％～35％。
15. the filter according to any one of claims 12 to 14, wherein the glass plate contains 5 to 50 mol% of F - in terms of an anion ratio.
16. A near infrared cut filter, wherein the near infrared cut filter comprises the filter of claim 15.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021-180650 | 2021-11-04 | ||
| JP2021180650 | 2021-11-04 | ||
| PCT/JP2022/039151 WO2023079973A1 (en) | 2021-11-04 | 2022-10-20 | Optical filter and near-infrared cut filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118159881A true CN118159881A (en) | 2024-06-07 |
Family
ID=86240990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280070504.3A Pending CN118159881A (en) | 2021-11-04 | 2022-10-20 | Optical filter and near infrared cut-off filter |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN118159881A (en) |
| TW (1) | TW202328714A (en) |
| WO (1) | WO2023079973A1 (en) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0733264B2 (en) * | 1990-09-28 | 1995-04-12 | 東芝硝子株式会社 | Protective film for phosphate glass |
| JP5439903B2 (en) * | 2008-03-31 | 2014-03-12 | 旭硝子株式会社 | Plate-shaped optical glass and end-face processing method for plate-shaped optical glass |
| JP2014208577A (en) * | 2013-03-29 | 2014-11-06 | 旭硝子株式会社 | Optical element and method of manufacturing optical element |
| CN108828694B (en) * | 2017-04-27 | 2023-01-17 | 肖特股份有限公司 | Optical component preferably having improved deterioration resistance and method for manufacturing the same |
| KR102555595B1 (en) * | 2017-09-27 | 2023-07-14 | 니폰 덴키 가라스 가부시키가이샤 | Glass plate and its manufacturing method |
| JP7059794B2 (en) * | 2018-05-18 | 2022-04-26 | Ａｇｃ株式会社 | Glass substrate and manufacturing method of glass substrate |
-
2022
- 2022-10-20 WO PCT/JP2022/039151 patent/WO2023079973A1/en unknown
- 2022-10-20 CN CN202280070504.3A patent/CN118159881A/en active Pending
- 2022-10-26 TW TW111140622A patent/TW202328714A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| TW202328714A (en) | 2023-07-16 |
| WO2023079973A1 (en) | 2023-05-11 |
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