JP4021191B2 - Ring-shaped ND filter and manufacturing method thereof - Google Patents

Ring-shaped ND filter and manufacturing method thereof Download PDF

Info

Publication number
JP4021191B2
JP4021191B2 JP2001384629A JP2001384629A JP4021191B2 JP 4021191 B2 JP4021191 B2 JP 4021191B2 JP 2001384629 A JP2001384629 A JP 2001384629A JP 2001384629 A JP2001384629 A JP 2001384629A JP 4021191 B2 JP4021191 B2 JP 4021191B2
Authority
JP
Japan
Prior art keywords
filter
circular
film
laminated
annular
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2001384629A
Other languages
Japanese (ja)
Other versions
JP2003185810A (en
Inventor
徹 鹿野
政幸 新井
Original Assignee
ペンタックス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ペンタックス株式会社 filed Critical ペンタックス株式会社
Priority to JP2001384629A priority Critical patent/JP4021191B2/en
Publication of JP2003185810A publication Critical patent/JP2003185810A/en
Application granted granted Critical
Publication of JP4021191B2 publication Critical patent/JP4021191B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Optical Elements Other Than Lenses (AREA)

Description

【０００１】
【技術分野】
本発明は、中心部程光透過率を小さくした輪帯状ＮＤフィルター及びその製造方法に関する。
【０００２】
【従来技術およびその問題点】
例えば、ＣＣＴＶ用レンズでは、機械的な小絞（大Ｆ値）の限界以上に光量を減少させ、見かけ上大きなＦ値を得るため、輪帯状のＮＤフィルター１０が用いられている。図１０、図１１はその概念図であり、透明基板１１の中心部上に、段階的に径の小さくなる円形ＮＤフィルター膜（光吸収膜）１２、１３、１４を、蒸着により同心状に積層形成してなっている。透明基板１１の厚さは、通常０．５ｍｍ前後、各円形ＮＤフィルター膜１２〜１４の厚さは、１０分の数μｍオーダである。この輪帯状ＮＤフィルター１０によると、機械絞が小絞になる程、透過光量が減少するため、見かけ上の大Ｆ値を得ることができる。
【０００３】
ところが、この輪帯状ＮＤフィルター１０を有するレンズにおいて、機械絞の開放時と最小絞時とで像性能を比較すると、僅かながらピント移動が生じ、像性能が悪化することが明らかとなった。
【０００４】
この問題点を解決するため、本出願人は既に、微視的に階段状をなす同心状の積層円形ＮＤフィルターの外囲の空間を、ＮＤフィルター膜と似た屈折率の透明接着剤で埋めると、ピント移動が改善されることを見出し、特許出願した（特開平１１‐２３８１０号公報）。同心状に積層形成される円形ＮＤフィルターは上述のようにμｍオーダーのきわめて薄いものであるが、輪帯状ＮＤフィルター全体として見たときには、中心部のみに積層厚が段階的に変化する屈折率が１．３〜２．６程度のＮＤフィルター膜が存在するから、これがレンズ作用をしてピント移動の原因となる。ＮＤフィルター膜の外囲を透明接着剤で埋めると、このレンズ作用をなくし、ピント移動を防止できるのである。
【０００５】
積層ＮＤフィルターの外囲を透明接着剤で埋めるには、積層ＮＤフィルターを二枚の透明基板で挟むのが実際的である。ところが、この構造において新たな問題が指摘されるに至った。すなわち、図１２に示すように、積層ＮＤフィルター１０は、一方の透明基板１１の中心部にＮＤフィルター膜１２、１３、１４を順次蒸着形成し、その後、これらのＮＤフィルター膜の外囲に接着剤１６を位置させて、他方の透明基板１５を接着する。このとき、従来は単に透明基板１１を水平面上に置いて自重により透明基板１５を重ねていた。しかし、ＮＤフィルター膜１２〜１４は透明基板１１の中心部のみに存在しているため、図に誇張して示すように、透明基板１５が透明基板１１に対して傾斜してしまい、平行度が損なわれる場合があることが判明した。両円形基板１１と１５の平行度が損なわれると、明らかに光学性能が悪化する。
【０００６】
【発明の目的】
本発明は、従って、透明基板の中心部に、微視的に階段状をなす積層円形ＮＤフィルター膜を同心状に積層形成し、この積層円形ＮＤフィルター膜の外囲に位置させた透明接着剤を介して別の透明基板を接着してなる輪帯状ＮＤフィルターにおいて、一対の円形透明基板の平行度を容易に保証できる輪帯状ＮＤフィルター及びその製造方法を得ることを目的とする。
【０００７】
【発明の概要】
本発明は、透明基板の中心部に、微視的に階段状をなす積層円形ＮＤフィルター膜を同心状に積層形成し、この積層円形ＮＤフィルター膜の外囲に位置させた透明接着剤を介して別の透明基板を接着してなる輪帯状ＮＤフィルターにおいて、上記透明基板の周縁部が、上記積層円形ＮＤフィルター膜と同心の円状をなし、上記一対の透明基板の間の周縁部に位置させて、中心部の積層円形ＮＤフィルター膜の積層厚と同等以上の積層厚を有し、かつ、上記円状の周縁部の周方向に並ぶ互いに不連続な３箇所以上の不連続スペーサ膜を形成したことを特徴としている。
このように周縁部に不連続スペーサ膜を形成すれば、一対の透明基板の平行性を確保することができ、光学性能の悪化を防ぐことができる。
【０００８】
本発明は、透明基板の中心部に、微視的に階段状をなす積層円形ＮＤフィルター膜を同心状に積層形成するステップ；上記透明基板における上記積層円形ＮＤフィルター膜と同心の円状をなす周縁部に、上記積層円形ＮＤフィルター膜と同等以上の厚さを有し、かつ、上記円状の周縁部の周方向に並ぶ互いに不連続な３箇所以上の不連続スペーサ膜を形成するステップ；及び上記積層円形ＮＤフィルター膜と不連続スペーサ膜との間に接着剤を位置させて、上記透明基板上に別の円形透明基板を接着するステップ；を有することを特徴とする。
【０００９】
積層円形ＮＤフィルター膜を形成するステップと、周縁スペーサ膜を形成するステップとは、別々の蒸着ステップとすることも可能であるが、同一の蒸着ステップで同一の材料を用いて実行するのが実際的である。
【００１０】
不連続スペーサ膜として構成する場合には、積層円形ＮＤフィルター膜を順次積層形成するとき、各層が少なくとも一部がオーバラップする態様で形成すればよい。また、周縁スペーサ膜は、積層円形ＮＤフィルター膜と同時に同一の材料により形成するのが実際的である。
【００１１】
積層円形ＮＤフィルター膜及び周縁スペーサ膜と透明接着剤は屈折率がほぼ等しい材料を選択することが好ましい。ＮＤフィルター膜の屈折率が通常１．３〜２．６であることを考慮すると、透明接着剤も、１．３〜２．６の屈折率のものを用いることが好ましい。
【００１２】
透明接着剤は、例えば、同心状の積層円形ＮＤフィルターの外囲にスピンコート法によって形成することができる。
【００１３】
本発明の輪帯状ＮＤフィルターは、機械的開口径を開放状態から最小絞状態の間で変化させる機械絞機構と併用して効果がある。
【００１４】
【発明の実施形態】
図１、図２は、本発明による輪帯状ＮＤフィルター１００の第一の実施形態を示す。図１０、図１１の従来例と同一の構成要素には同一の符号を付すと、円形をなす透明基板１１上には、その中心部にＮＤフィルター膜（光吸収膜）１２、１３、１４が蒸着形成され、周縁部に、円形ＮＤフィルター膜１２〜１４と同心の全環状をなす環状スペーサ膜２２、２３、２４が蒸着形成されている。これら全環状周縁スペーサ膜２２〜２４は、ＮＤフィルター膜１２〜１４の蒸着形成工程と同一の工程において形成され、従って、その各膜厚及び合計膜厚は等しい。この円形ＮＤフィルター膜１２〜１４と、全環状周縁スペーサ膜２２〜２４との間の空間には、透明接着剤１６が充填され、別の円形透明基板１５が接着されている。
【００１５】
以上の輪帯状ＮＤフィルター１００は、例えば次の工程によって製造される。
透明基板１１上に、円形ＮＤフィルター膜１２〜１４と全環状周縁スペーサ膜２２〜２４とを同時に蒸着によって形成する工程；
円形ＮＤフィルター膜１２〜１４と、環状周縁スペーサ膜２２〜２４との間の空間に、例えばスピンコート法により正しく秤量した透明接着剤１６を充填する工程；及び
透明接着剤１６上に透明基板１５を接着する工程；
である。
【００１６】
このように、透明基板１１の周縁に環状周縁スペーサ膜２２〜２４が存在すると、透明基板１５が透明基板１１に対して傾く（平行度が損なわれる）ことがなく、光学性能が悪化することがない。環状周縁スペーサ膜２２〜２４は、ＮＤフィルターとして用いるとき、機械絞機構が最大開口（開放状態）に設定されるときにおいても光束が通過しない部分（非使用部分）に形成される。別言すると、機械絞機構の最大開口（開放状態）では、全環状周縁スペーサ膜２２〜２４のすぐ内側までが輪帯状ＮＤフィルターとして使用される。
【００１７】
図３、図４は、本発明の別の実施形態を示す。この実施形態は、全環状環状スペーサ膜２２〜２４に代えて、不連続スペーサ膜２２Ａ、２３Ａ、２４Ａを形成した実施形態である。透明基板１５の平面は、３点で決定されるから、不連続スペーサ膜２２Ａ〜２４Ａは、３箇所以上に、好ましくは等角度間隔で形成するのがよい。このように不連続スペーサ膜２２Ａ〜２４Ａとすると、透明接着剤１６が余分であったとき、余分な透明接着剤１６を隣り合う不連続スペーサ膜２２Ａ〜２４Ａの間から外部に排出することができる。
【００１８】
図５、図６は、本発明のさらに別の実施形態を示す。この実施形態では、不連続スペーサ膜２２Ｂ、２３Ｂ、２４Ｂを積層形成する際、蒸着マスクの位置ずれ（回転位相ずれ）を考慮して、周方向長さを十分確保し、各層の少なくとも一部を確実にオーバラップさせている。図５にダブルハッチングを付した部分が、不連続スペーサ膜２２Ｂ〜２４Ｂのオーバラップ部分である。なお、不連続スペーサ膜を形成する際の蒸着マスクの位置ずれ（回転位相ずれ）を防止するために、透明基板１１に、図９に示すような位相合わせマーク（凹部）１１Ａを形成し、この位相合わせマーク１１Ａを利用して蒸着マスクとの位相合わせを行うことができる。
【００１９】
以上の各実施形態ではいずれも、周縁スペーサ膜２２〜２４（２２Ａ〜２４Ａ）を円形ＮＤフィルター膜１２〜１４の蒸着と同時に形成しており、従って周縁スペーサ膜と円形ＮＤフィルター膜１２〜１４の膜厚とは等しい。これに対し、図７、図８に示す実施形態は、全環状周縁スペーサ膜２５を、円形ＮＤフィルター膜１２〜１４とは独立した単層として、かつその膜厚を円形ＮＤフィルター膜１２〜１４の合計膜厚より大きくした実施形態である。この実施形態によっても透明基板１１と透明基板１５の平行度を保持することができる。この実施形態では、円形ＮＤフィルター膜１２〜１４の上に微小厚の透明接着剤１６が存在することになり、僅かにしろ、光路長を変化させるから、円形ＮＤフィルター膜１２〜１４の厚さはできるだけ小さいこと（つまり、円形ＮＤフィルター膜１２〜１４の合計膜厚と単層周縁スペーサ膜２５の膜厚差ができるだけ小さいこと）が望ましい。全環状周縁スペーサ膜２５を不連続スペーサ膜としてもよいことは勿論である。
【００２０】
透明接着剤１６の屈折率は、理想的にはＮＤフィルター膜（光吸収膜）円形ＮＤフィルター膜１２〜１４の屈折率と同一であることが好ましいが、階段状の空間が似た屈折率の物質（透明接着剤１６）で満たされることにより、機械絞の開放状態と最小絞状態での光路長の差は大きなものではなくなる。以上のいずれの実施形態によっても、問題のレンズ作用は小さくなり、ピント移動は無視できるレベルになる。
【００２１】
【発明の効果】
本発明によれば、透明基板の中心部に、微視的に階段状をなす積層円形ＮＤフィルター膜を同心状に積層形成し、この積層円形ＮＤフィルター膜の外囲に位置させた透明接着剤を介して別の透明基板を接着してなる輪帯状ＮＤフィルターにおいて、一対の円形透明基板の平行度を容易に保証し、機械絞の開放状態と最小絞状態でのピント移動を小さくすることができる。
【図面の簡単な説明】
【図１】本発明に輪帯状ＮＤフィルターの一実施形態を示す平面図である。
【図２】図１のII−II線に沿う模式断面図である。
【図３】本発明に輪帯状ＮＤフィルターの一実施形態を示す平面図である。
【図４】図３のIV−IV線に沿う模式断面図である。
【図５】本発明に輪帯状ＮＤフィルターの一実施形態を示す平面図である。
【図６】図５のVI−VI線に沿う模式断面図である。
【図７】本発明に輪帯状ＮＤフィルターの一実施形態を示す平面図である。
【図８】図７のVIII−VIII線に沿う模式断面図である。
【図９】同正面図である。
【図１０】従来の輪帯状ＮＤフィルターの一例を示す平面図である。
【図１１】図１０のXI−XI線に沿う模式断面図である。
【図１２】別の従来例を示す模式断面図である。
【符号の説明】
１００ 輪帯状ＮＤフィルター
１１ １５ 透明基板
１２ １３ １４ 円形ＮＤフィルター膜
１６ 透明接着剤
２２ ２３ ２４ 全環状周縁スペーサ膜
２２Ａ ２３Ａ ２４Ａ 不連続周縁スペーサ膜
２２Ｂ ２３Ｂ ２４Ｂ 不連続周縁スペーサ膜
２５ 単層周縁スペーサ膜[0001]
【Technical field】
The present invention relates to a ring-shaped ND filter having a light transmittance that decreases toward the center, and a method for manufacturing the same.
[0002]
[Prior art and its problems]
For example, in a CCTV lens, an annular ND filter 10 is used in order to reduce the amount of light beyond the limit of a mechanical small aperture (large F value) and obtain an apparently large F value. FIGS. 10 and 11 are conceptual diagrams thereof. On the central portion of the transparent substrate 11, circular ND filter films (light absorption films) 12, 13, and 14 whose diameters are gradually reduced are stacked concentrically by vapor deposition. It is formed. The thickness of the transparent substrate 11 is usually around 0.5 mm, and the thickness of each circular ND filter film 12 to 14 is on the order of several tenths of μm. According to the ring-shaped ND filter 10, the amount of transmitted light decreases as the mechanical aperture becomes smaller, so that an apparent large F value can be obtained.
[0003]
However, when the image performance of the lens having the annular ND filter 10 is compared between when the mechanical aperture is open and when the minimum aperture is reduced, it is clear that the image performance deteriorates slightly due to a slight focus shift.
[0004]
In order to solve this problem, the present applicant has already filled the outer space of a concentric laminated circular ND filter microscopically stepped with a transparent adhesive having a refractive index similar to that of the ND filter film. The inventors have found that the focus movement is improved and filed a patent application (Japanese Patent Laid-Open No. 11-23810). As described above, the circular ND filter that is concentrically laminated is extremely thin, on the order of μm. However, when viewed as a whole of the annular ND filter, the refractive index of the laminated thickness that changes in a stepwise manner only at the center portion. Since an ND filter film of about 1.3 to 2.6 exists, this acts as a lens and causes focus movement. If the outer periphery of the ND filter film is filled with a transparent adhesive, this lens action can be eliminated and focus movement can be prevented.
[0005]
In order to fill the outer periphery of the laminated ND filter with a transparent adhesive, it is practical to sandwich the laminated ND filter between two transparent substrates. However, new problems have been pointed out in this structure. That is, as shown in FIG. 12, in the laminated ND filter 10, the ND filter films 12, 13, and 14 are sequentially deposited on the central portion of one transparent substrate 11, and then adhered to the outer periphery of these ND filter films. The agent 16 is positioned and the other transparent substrate 15 is bonded. At this time, conventionally, the transparent substrate 11 is simply placed on a horizontal plane and the transparent substrate 15 is overlapped by its own weight. However, since the ND filter films 12 to 14 are present only in the central portion of the transparent substrate 11, the transparent substrate 15 is inclined with respect to the transparent substrate 11 as shown in an exaggerated manner in the figure, and the parallelism is low. It has been found that it may be damaged. When the parallelism between the circular substrates 11 and 15 is impaired, the optical performance is clearly deteriorated.
[0006]
OBJECT OF THE INVENTION
Accordingly, the present invention provides a transparent adhesive in which a laminated circular ND filter film having a microscopic step shape is formed concentrically at the center of a transparent substrate, and is positioned at the outer periphery of the laminated circular ND filter film. Another object of the present invention is to provide a ring-shaped ND filter that can easily guarantee the parallelism of a pair of circular transparent substrates and a method of manufacturing the same.
[0007]
SUMMARY OF THE INVENTION
In the present invention, a laminated circular ND filter film having a microscopic step shape is concentrically laminated at the center of a transparent substrate, and a transparent adhesive placed on the outer periphery of the laminated circular ND filter film is used. In the annular ND filter formed by adhering another transparent substrate, the peripheral portion of the transparent substrate is concentric with the laminated circular ND filter film, and is positioned at the peripheral portion between the pair of transparent substrates. Three or more discontinuous spacer films having a stack thickness equal to or greater than the stack thickness of the stacked circular ND filter film at the center and discontinuous with each other arranged in the circumferential direction of the circular peripheral edge. It is characterized by the formation .
If the discontinuous spacer film is formed on the peripheral portion in this way, the parallelism of the pair of transparent substrates can be ensured, and deterioration of the optical performance can be prevented.
[0008]
The present invention includes a step of concentrically forming a laminated circular ND filter film having a microscopic step shape at the center of a transparent substrate; forming a concentric circular shape with the laminated circular ND filter film on the transparent substrate . on the periphery, steps possess the laminated circular ND filter film equal to or greater than the thickness, and to form the circular periphery of circumferentially arranged mutually discontinuous three or more discontinuous spacer film; And adhering another circular transparent substrate on the transparent substrate by positioning an adhesive between the laminated circular ND filter film and the discontinuous spacer film .
[0009]
The step of forming the laminated circular ND filter film and the step of forming the peripheral spacer film can be performed as separate vapor deposition steps, but it is actually performed by using the same material in the same vapor deposition step. Is.
[0010]
In the case of forming as a discontinuous spacer film , when the stacked circular ND filter films are sequentially stacked, each layer may be formed in such a manner that at least a part thereof overlaps. Further, it is practical that the peripheral spacer film is formed of the same material as the laminated circular ND filter film.
[0011]
For the laminated circular ND filter film, the peripheral spacer film and the transparent adhesive, it is preferable to select materials having substantially the same refractive index. Considering that the refractive index of the ND filter film is usually 1.3 to 2.6, it is preferable to use a transparent adhesive having a refractive index of 1.3 to 2.6.
[0012]
The transparent adhesive can be formed, for example, by spin coating on the outer periphery of a concentric laminated circular ND filter.
[0013]
The annular ND filter of the present invention is effective in combination with a mechanical aperture mechanism that changes the mechanical aperture diameter from the open state to the minimum aperture state.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show a first embodiment of an annular ND filter 100 according to the present invention. 10 and FIG. 11, the same constituent elements as those in the conventional example are denoted by the same reference numerals. On the transparent substrate 11 having a circular shape, ND filter films (light absorption films) 12, 13, and 14 are provided at the center. The annular spacer films 22, 23, and 24 are formed on the peripheral edge by vapor deposition on the peripheral edge portion. These all-annular peripheral spacer films 22 to 24 are formed in the same process as the vapor deposition forming process of the ND filter films 12 to 14, and therefore the respective film thicknesses and the total film thicknesses are equal. A space between the circular ND filter films 12 to 14 and the all-circumferential peripheral spacer films 22 to 24 is filled with a transparent adhesive 16 and another circular transparent substrate 15 is bonded thereto.
[0015]
The annular ND filter 100 described above is manufactured, for example, by the following process.
Forming the circular ND filter films 12 to 14 and the all-annular peripheral spacer films 22 to 24 on the transparent substrate 11 by vapor deposition;
Filling the space between the circular ND filter films 12 to 14 and the annular peripheral spacer films 22 to 24 with the transparent adhesive 16 correctly weighed by, for example, spin coating; and the transparent substrate 15 on the transparent adhesive 16 Adhering steps;
It is.
[0016]
As described above, when the annular peripheral spacer films 22 to 24 are present at the periphery of the transparent substrate 11, the transparent substrate 15 is not inclined with respect to the transparent substrate 11 (the parallelism is not impaired), and the optical performance is deteriorated. Absent. When used as an ND filter, the annular peripheral spacer films 22 to 24 are formed in a portion (non-use portion) through which a light beam does not pass even when the mechanical aperture mechanism is set to the maximum opening (open state). In other words, in the maximum opening (open state) of the mechanical aperture mechanism, the area just inside the all-circumferential peripheral spacer films 22 to 24 is used as the annular ND filter.
[0017]
3 and 4 show another embodiment of the present invention. In this embodiment, discontinuous spacer films 22A, 23A, and 24A are formed in place of the all-annular annular spacer films 22 to 24. Since the plane of the transparent substrate 15 is determined at three points, the discontinuous spacer films 22A to 24A are preferably formed at three or more locations, preferably at equiangular intervals. As described above, when the discontinuous spacer films 22A to 24A are used, when the transparent adhesive 16 is excessive, the excess transparent adhesive 16 can be discharged to the outside from between the adjacent discontinuous spacer films 22A to 24A. .
[0018]
5 and 6 show still another embodiment of the present invention. In this embodiment, when stacking the discontinuous spacer films 22B, 23B, and 24B, in consideration of the positional deviation (rotational phase deviation) of the vapor deposition mask, the circumferential length is sufficiently secured, and at least a part of each layer is formed. It is sure to overlap. A portion hatched in FIG. 5 is an overlap portion of the discontinuous spacer films 22B to 24B. In addition, in order to prevent positional deviation (rotation phase deviation) of the vapor deposition mask when forming the discontinuous spacer film, a phase alignment mark (concave part) 11A as shown in FIG. Phase alignment with the vapor deposition mask can be performed using the phase alignment mark 11A.
[0019]
In each of the above embodiments, the peripheral spacer films 22 to 24 (22A to 24A) are formed simultaneously with the deposition of the circular ND filter films 12 to 14, and accordingly, the peripheral spacer film and the circular ND filter films 12 to 14 are formed. It is equal to the film thickness. On the other hand, in the embodiment shown in FIGS. 7 and 8, the all-circumferential peripheral spacer film 25 is formed as a single layer independent of the circular ND filter films 12 to 14, and the film thickness thereof is circular ND filter films 12 to 14. This embodiment is larger than the total film thickness. Also in this embodiment, the parallelism of the transparent substrate 11 and the transparent substrate 15 can be maintained. In this embodiment, since the transparent adhesive 16 having a very small thickness exists on the circular ND filter films 12 to 14 and slightly changes the optical path length, the thickness of the circular ND filter films 12 to 14 is changed. Is preferably as small as possible (that is, the difference between the total film thickness of the circular ND filter films 12 to 14 and the film thickness of the single-layer peripheral spacer film 25 is as small as possible). Of course, the all-circumferential peripheral spacer film 25 may be a discontinuous spacer film.
[0020]
The refractive index of the transparent adhesive 16 is ideally the same as the refractive index of the ND filter film (light absorption film) circular ND filter films 12 to 14, but the stepped space has a similar refractive index. By being filled with the substance (transparent adhesive 16), the difference in optical path length between the open state of the mechanical stop and the minimum stop state is not large. In any of the above embodiments, the lens action in question is reduced, and the focus movement is negligible.
[0021]
【The invention's effect】
According to the present invention, a transparent circular adhesive is formed by concentrically forming a laminated circular ND filter film having a microscopic stepped shape at the center of a transparent substrate, and is positioned at the outer periphery of the laminated circular ND filter film. In a ring-shaped ND filter formed by adhering another transparent substrate via a pair, it is possible to easily guarantee the parallelism of a pair of circular transparent substrates and to reduce the focus movement in the open state of the mechanical aperture and the minimum aperture state. it can.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of an annular ND filter according to the present invention.
FIG. 2 is a schematic cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a plan view showing an embodiment of an annular ND filter according to the present invention.
4 is a schematic cross-sectional view taken along line IV-IV in FIG.
FIG. 5 is a plan view showing an embodiment of an annular ND filter according to the present invention.
6 is a schematic cross-sectional view taken along line VI-VI in FIG.
FIG. 7 is a plan view showing an embodiment of an annular ND filter according to the present invention.
8 is a schematic cross-sectional view taken along line VIII-VIII in FIG.
FIG. 9 is a front view of the same.
FIG. 10 is a plan view showing an example of a conventional ring-shaped ND filter.
11 is a schematic cross-sectional view taken along the line XI-XI in FIG.
FIG. 12 is a schematic cross-sectional view showing another conventional example.
[Explanation of symbols]
100 ring-shaped ND filter 11 15 transparent substrate 12 13 14 circular ND filter film 16 transparent adhesive 22 23 24 all-circumferential peripheral spacer film 22A 23A 24A discontinuous peripheral spacer film 22B 23B 24B discontinuous peripheral spacer film 25 single layer peripheral spacer film

Claims (8)

透明基板の中心部に、微視的に階段状をなす積層円形ＮＤフィルター膜を同心状に積層形成し、この積層円形ＮＤフィルター膜の外囲に位置させた透明接着剤を介して別の透明基板を接着してなる輪帯状ＮＤフィルターにおいて、
上記透明基板の周縁部が、上記積層円形ＮＤフィルター膜と同心の円状をなし、
上記一対の透明基板の間の周縁部に位置させて、中心部の積層円形ＮＤフィルター膜の積層厚と同等以上の積層厚を有し、かつ、上記円状の周縁部の周方向に並ぶ互いに不連続な３箇所以上の不連続スペーサ膜を形成したことを特徴とする輪帯状ＮＤフィルター。A laminated circular ND filter film having a microscopic step shape is formed concentrically on the central portion of the transparent substrate, and another transparent is provided via a transparent adhesive positioned on the outer periphery of the laminated circular ND filter film. In an annular ND filter formed by bonding substrates,
The peripheral portion of the transparent substrate has a circular shape concentric with the laminated circular ND filter film,
By positioning the peripheral edge between the pair of transparent substrates, have a lamination thickness of the laminated thick and more comparable laminated circular ND filter membrane center, and each other arranged in the circumferential direction of the circular periphery An annular ND filter characterized by forming discontinuous spacer films at three or more discontinuous positions . 請求項１記載の輪帯状ＮＤフィルターにおいて、上記不連続スペーサ膜は、積層円形ＮＤフィルター膜を順次積層形成するとき、各層が少なくとも一部がオーバラップする態様で形成されている輪帯状ＮＤフィルター。The ring-shaped ND filter according to claim 1, wherein the discontinuous spacer film is formed in such a manner that at least a part of each layer overlaps when the stacked circular ND filter films are sequentially stacked. 請求項１または２記載の輪帯状ＮＤフィルターにおいて、上記不連続スペーサ膜は、積層円形ＮＤフィルター膜と同時に同一の材料により形成されている輪帯状ＮＤフィルター。 3. The ring-shaped ND filter according to claim 1, wherein the discontinuous spacer film is formed of the same material as the laminated circular ND filter film. 請求項１ないし３のいずれか１項記載の輪帯状ＮＤフィルターにおいて、積層円形ＮＤフィルター膜及び不連続スペーサ膜と透明接着剤は屈折率がほぼ等しい材料が選択されている輪帯状ＮＤフィルター。4. An annular ND filter according to claim 1, wherein the laminated circular ND filter film, the discontinuous spacer film, and the transparent adhesive are selected from materials having substantially the same refractive index. 透明基板の中心部に、微視的に階段状をなす積層円形ＮＤフィルター膜を同心状に積層形成するステップ；
上記透明基板における上記積層円形ＮＤフィルター膜と同心の円状をなす周縁部に、上記積層円形ＮＤフィルター膜と同等以上の厚さを有し、かつ、上記円状の周縁部の周方向に並ぶ互いに不連続な３箇所以上の不連続スペーサ膜を形成するステップ；及び
上記積層円形ＮＤフィルター膜と不連続スペーサ膜との間に接着剤を位置させて、上記透明基板上に別の円形透明基板を接着するステップ；
を有することを特徴とする輪帯状ＮＤフィルターの製造方法。A step of concentrically laminating a laminated circular ND filter film having a microscopic stepped shape at the center of the transparent substrate;
A peripheral portion which forms the laminated circular ND filter membrane concentric circular in the transparent substrate, possess the laminated circular ND filter film equal to or greater than the thickness, and arranged in the circumferential direction of the circular periphery Forming discontinuous spacer films at three or more points that are discontinuous with each other ; and placing another adhesive between the laminated circular ND filter film and the discontinuous spacer film on the transparent substrate. Adhering steps;
The manufacturing method of the ring-shaped ND filter characterized by having. 請求項５記載の輪帯状ＮＤフィルターの製造方法において、上記積層円形ＮＤフィルター膜を形成するステップと、不連続スペーサ膜を形成するステップとは、同一の蒸着工程で同一の材料を用いて実行される輪帯状ＮＤフィルターの製造方法。 6. The method for manufacturing an annular ND filter according to claim 5, wherein the step of forming the laminated circular ND filter film and the step of forming the discontinuous spacer film are performed using the same material in the same vapor deposition process. A manufacturing method of an annular ND filter. 請求項５または６記載の輪帯状ＮＤフィルターの製造方法において、上記不連続スペーサ膜は、積層円形ＮＤフィルター膜を順次積層形成するとき、各層の少なくとも一部がオーバラップする態様で形成されている輪帯状ＮＤフィルターの製造方法。 7. The method of manufacturing an annular ND filter according to claim 5, wherein the discontinuous spacer film is formed in such a manner that at least a part of each layer overlaps when the laminated circular ND filter films are sequentially laminated. A manufacturing method of an annular ND filter. 請求項５ないし７のいずれか１項記載のＮＤフィルターの製造方法において、透明接着剤は、同心状の積層円形ＮＤフィルターの外囲にスピンコート法によって形成されている輪帯状ＮＤフィルターの製造方法。 8. The method for manufacturing an ND filter according to claim 5, wherein the transparent adhesive is formed by spin coating on the outer periphery of the concentric laminated circular ND filter. .
JP2001384629A 2001-12-18 2001-12-18 Ring-shaped ND filter and manufacturing method thereof Expired - Fee Related JP4021191B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001384629A JP4021191B2 (en) 2001-12-18 2001-12-18 Ring-shaped ND filter and manufacturing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001384629A JP4021191B2 (en) 2001-12-18 2001-12-18 Ring-shaped ND filter and manufacturing method thereof

Publications (2)

Publication Number Publication Date
JP2003185810A JP2003185810A (en) 2003-07-03
JP4021191B2 true JP4021191B2 (en) 2007-12-12

Family

ID=27594315

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001384629A Expired - Fee Related JP4021191B2 (en) 2001-12-18 2001-12-18 Ring-shaped ND filter and manufacturing method thereof

Country Status (1)

Country Link
JP (1) JP4021191B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7221648B2 (en) * 2018-10-29 2023-02-14 三星電子株式会社 Lighting equipment and inspection equipment

Also Published As

Publication number Publication date
JP2003185810A (en) 2003-07-03

Similar Documents

Publication Publication Date Title
JP4979755B2 (en) Device having a light absorbing mask
KR101623632B1 (en) Method for manufacturing spatial light modulation element, spatial light modulation element, spatial light modulator and exposure apparatus
KR20180113472A (en) Light-guide optical element and method of its manufacture
CN101606243B (en) Structure and the method for internal noise is reduced in the camera system utilizing optics stack
JP2010510542A (en) Control of stray light and related method in camera system employing optical laminate
JP5459722B2 (en) Laminated wafer lens and method for manufacturing the same, multilayer lens
JP2013156619A (en) Nd filter with ir cut function
US11537008B2 (en) Optical element, liquid crystal display device, and projection-type image display device
JP4692486B2 (en) Optical filter and optical filter manufacturing method
JP4021191B2 (en) Ring-shaped ND filter and manufacturing method thereof
WO2022227135A1 (en) Display panel and preparation method for display panel
JP4914955B2 (en) ND filter with IR cut function
JP2011081083A (en) Neutral density (nd) filter
JP3771678B2 (en) ND filter
JP3129386B2 (en) Optical device
JP3250190B2 (en) Ring-shaped ND filter
JP2004151624A (en) Tip optical element for microscope immersion objective
JPH0516003B2 (en)
JP2006509240A (en) High refractive index coated light control film
TW201112240A (en) Optical recording medium and method for manufacturing the same
JP2003279726A (en) Optical low pass filter with infrared blocking filter
TW201243391A (en) Optical element, method for making the same, and projection apparatus
JP2011085742A (en) Color filter and method of manufacturing the same
JP2004055971A (en) Imaging device
JP3218195U (en) ND filter

Legal Events

Date Code Title Description
A625 Written request for application examination (by other person)

Free format text: JAPANESE INTERMEDIATE CODE: A625

Effective date: 20041108

A711 Notification of change in applicant

Free format text: JAPANESE INTERMEDIATE CODE: A711

Effective date: 20050120

RD02 Notification of acceptance of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7422

Effective date: 20050802

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A821

Effective date: 20050804

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20070117

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20070123

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20070316

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20070918

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20070926

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20101005

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111005

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121005

Year of fee payment: 5

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313111

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121005

Year of fee payment: 5

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313111

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121005

Year of fee payment: 5

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121005

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20131005

Year of fee payment: 6

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

LAPS Cancellation because of no payment of annual fees