JPS60150005A - Filter of copying machine or the like - Google Patents

Filter of copying machine or the like

Info

Publication number
JPS60150005A
JPS60150005A JP579984A JP579984A JPS60150005A JP S60150005 A JPS60150005 A JP S60150005A JP 579984 A JP579984 A JP 579984A JP 579984 A JP579984 A JP 579984A JP S60150005 A JPS60150005 A JP S60150005A
Authority
JP
Japan
Prior art keywords
filter
light
thin film
incident
incident angle
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.)
Granted
Application number
JP579984A
Other languages
Japanese (ja)
Other versions
JPH0464056B2 (en
Inventor
Shinji Kita
喜多　伸児
Yasuo Yamada
康男 山田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujifilm Business Innovation Corp
Original Assignee
Fuji Xerox Co Ltd
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 Fuji Xerox Co Ltd filed Critical Fuji Xerox Co Ltd
Priority to JP579984A priority Critical patent/JPS60150005A/en
Publication of JPS60150005A publication Critical patent/JPS60150005A/en
Publication of JPH0464056B2 publication Critical patent/JPH0464056B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G02B5/285—Interference filters comprising deposited thin solid films
    • G02B5/286—Interference filters comprising deposited thin solid films having four or fewer layers, e.g. for achieving a colour effect
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
    • G03G15/043—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with means for controlling illumination or exposure
    • G03G15/0435—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with means for controlling illumination or exposure by introducing an optical element in the optical path, e.g. a filter

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Systems Of Projection Type Copiers (AREA)
  • Optical Filters (AREA)
  • Optical Elements Other Than Lenses (AREA)

Abstract

PURPOSE:To make the color rendering property and density of a copy uniform by forming a thin film on a flat plate-like transparent substrate of a filter in such a way that the thickness of the thin film is specifically disposed with respect to the incident angle of the ray incident thereto. CONSTITUTION:A filter 5 is so constituted that a thin film 7 consisting of, for example, mangnesium fluoride, having no light absorptivity is formed in a single layer on a flat plate-shaped transparent substrate 6 of glass, etc. The thickness (d) of the thin film is formed to such a film thickness distribution as to satisfy the equation with respect to the incident angle theta1 of the ray incident thereto. Only the light of a prescribed wavelength region out of the light incident to the filter 5 is thereby transmitted always at a specified transmittivity through the filter irrespectively of the incident angle thereof, by which the quality and quantity of the light after transmission through the filter are made uniform. The uniformity of the color rendering property and density of the copy is thus improved.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、複写機等に用いて光質補正を行うフィルター
（−係り、特（＝感材面幅方向での光質・光酸の均一化
を図ることのできるフィルターに関する。Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a filter for correcting light quality used in copying machines, etc. This invention relates to a filter that can achieve uniformity.

〔従来技術〕[Prior art]

従来より、比較的薄い平板状ガラス基板の表面（−蒸着
処理等を施し、フッ化マグネシウム（ＭｇＦ２）等の薄
膜を形成し、これによって所定の波長域の光だけを一定
の透過率で透過させるフィルターが知られている。また
、複写機等においては、この種のフィルターを光学系に
設置し、これによって感材に入射する光質な一定に維持
するものが提案されている。Conventionally, a thin film such as magnesium fluoride (MgF2) is formed on the surface of a relatively thin flat glass substrate (by vapor deposition, etc.), thereby transmitting only light in a predetermined wavelength range at a constant transmittance. Filters are known.Furthermore, in copying machines and the like, it has been proposed to install this type of filter in the optical system, thereby maintaining a constant quality of light incident on the sensitive material.

そして、上記のような光学系では、例えば複写機につい
て説明すると、第１図（二示すように、レンズ（１）と
感光体（２）との間に上記フィルター（３）を取付け、
このフィルター（３）を透過した光を感光体（２）上（
二照射させるように構成されており、上記レンズ（１）
からの光は、光軸（４）側から外れるにつれ斜方向から
フィルター（３）に入射する。また、上記フィルター（
３）は、薄膜が均一の厚さに形成されているため、この
フィルター（３）への入射角がフィルター中央部（８ａ
）から外部に向がうにつれて変化する。In the above-mentioned optical system, for example, in the case of a copying machine, as shown in FIG.
The light transmitted through this filter (3) is directed onto the photoreceptor (2) (
The above lens (1) is configured to emit two irradiations.
The light enters the filter (3) from an oblique direction as it deviates from the optical axis (4) side. In addition, the above filter (
3), since the thin film is formed to have a uniform thickness, the incident angle to this filter (3) is at the center of the filter (8a
) changes as one moves outward.

ところで、この種のフィルターは、特定の波長域の光だ
けを透過させるものであるが、このフィルターでの入射
角によって分光透過特性が一部変化する特性を有してお
り、例えば第２図に示すよ・−うに、入射角Ｏ０で入射
する光の透過率Ａと、入射角８０文の透過率Ｂとをみる
と、長波長側の波長限界域付近における後者の透過率が
大幅に低下する。By the way, this type of filter only transmits light in a specific wavelength range, but its spectral transmission characteristics partially change depending on the angle of incidence on the filter, for example, as shown in Figure 2. As shown, when we look at the transmittance A of light incident at an incident angle of 00 and the transmittance B of light incident at an incident angle of 80, the transmittance of the latter decreases significantly near the wavelength limit region on the long wavelength side. .

また、複写機（−おいては、この種のフィルターを用い
た場合、フィルターを透過する光の透過率が変化すると
、感光体に入射する光の光質・光量が変化する。例えば
、第３図に示すように、連続スペクトルの光Ｃを放射す
るリニアハロゲンランプを光源に用い、所定の分光感度
りを有する感光体上の中央部（２ａ）での実効光量（斜
線領域）と、同幅方向端部（２ｂ）での実効光量（横線
領域）をを比較してみると、後者において、７０００Ａ
”前後の波長による光量が低下する。In addition, when using this type of filter in a copying machine (-), if the transmittance of light passing through the filter changes, the quality and amount of light incident on the photoreceptor will change. As shown in the figure, a linear halogen lamp that emits light C in a continuous spectrum is used as a light source, and the width is the same as the effective light amount (hatched area) at the center (2a) on the photoreceptor having a predetermined spectral sensitivity. Comparing the effective light amount (horizontal line area) at the direction end (2b), it is found that in the latter, 7000A
``The amount of light depending on the wavelengths before and after is reduced.

従って、上記フィルターを複写機に使用してコピーを行
うと、コピー用紙の中央部と周辺部とでは、その画像濃
度にムラが発生していた。また、カラー複写機において
も、同様の理由から、カラーコピーの演色性の低下を招
き問題となっていた。Therefore, when the above-mentioned filter is used in a copying machine to make a copy, unevenness occurs in the image density between the center and the periphery of the copy paper. Further, in color copying machines as well, for the same reason, there has been a problem in that the color rendering properties of color copies deteriorate.

〔発明の目的〕[Purpose of the invention]

従って、本発明は上記従来のフィルターにおける欠点を
除去することを目的とするものであり、よυ詳しくは、
複写物における演色性及び濃度の均一化を図ることので
きる複写機等のフィルターを提供することにある。Therefore, the present invention aims to eliminate the drawbacks of the above-mentioned conventional filters.
An object of the present invention is to provide a filter for a copying machine, etc., which can uniformize color rendering properties and density in copies.

〔発明の構成〕[Structure of the invention]

即ち、本発明の複写機等のフィルターは、複写機等の光
学系の光源から感材に至る光路中に設置され、平板状透
明基板上に薄膜が形成されたものであり、この薄膜の膜
厚ｄは、これに入射する光線の入射角θｌに対して、 となるような膜厚分布に形成されており、これによって
上記フィルターに入射した光のうち、所定板長域の光だ
けを、その入射角にかかわりなく常に一定の透過率で透
過させ、上記フィルター透過後の光の光質・光量を均一
にするものである。That is, the filter for copying machines, etc. of the present invention is installed in the optical path from the light source of the optical system of the copying machine etc. to the sensitive material, and has a thin film formed on a flat transparent substrate. The thickness d is formed to have a film thickness distribution such that, with respect to the incident angle θl of the light beam incident on the filter, only the light in a predetermined plate length region of the light incident on the filter is filtered. Regardless of the angle of incidence, the light is transmitted at a constant transmittance, and the quality and quantity of light after passing through the filter is made uniform.

〔実施例〕〔Example〕

以下、添付図面に示す実施例に基づいて、本発明に係る
複写機等のフィルターを説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A filter for a copying machine or the like according to the present invention will be described below based on embodiments shown in the accompanying drawings.

第４図は、本発明に係る複写機等のフィルターの説明図
であり、このフィルター（５）は、ガラス等の平板状透
明基板（６）上に光吸収性のない、例えばフッ化マグネ
シウム（ＭｇＦ２）からなる薄膜（７）が単層に形成さ
れた構成となっている。FIG. 4 is an explanatory diagram of a filter for a copying machine or the like according to the present invention. The thin film (7) made of MgF2) is formed in a single layer.

そして、上記薄膜（７）の膜厚は、上記フィルター（５
）全域に亘り、入射角によらず常に一定の分光透過率と
なるような膜厚分布に形成されてＪ／ソる。The thickness of the thin film (7) is determined by the thickness of the thin film (7) of the filter (5).
) The film is formed to have a film thickness distribution that always provides a constant spectral transmittance regardless of the incident angle over the entire area.

ところで、この膜厚分布は次のようにしてめられる。一
般に、光吸収性のない薄膜において、そこでの反射率と
透過率との和は常に一定であるため、反射率をもとＣ二
して透過率を調べてみる。By the way, this film thickness distribution can be determined as follows. Generally, in a thin film that does not absorb light, the sum of its reflectance and transmittance is always constant, so let's examine the transmittance using C2 based on the reflectance.

この反射率は、上記薄膜の上下面で反射する光線の位相
差δから決定されることが知られており、この位相差δ
は、薄膜の屈折率をル、膜厚をｄ、屈折角をａｌ、光線
の波長なλとすると、４πｎ（Ｌｃｏｓθ δ＝　λ　・・・・・・・・・（ａｌ で表わされる。It is known that this reflectance is determined from the phase difference δ between the light rays reflected on the upper and lower surfaces of the thin film, and this phase difference δ
is expressed as 4πn (L cos θ δ=λ . . . (al), where L is the refractive index of the thin film, d is the film thickness, al is the refraction angle, and λ is the wavelength of the light ray.

ここで、屈折率ｎは、薄膜を形成する物質（二より決定
されるが、ここでは例えばｒＬ２の屈折率を有する物質
を用い、任意のある波長についてその反射率を調べてみ
ると、この反射率を決定する因子は、（ａ）式において
膜厚ｄと屈折角θである。Here, the refractive index n is determined from the material forming the thin film (2), but here, for example, if a material with a refractive index of rL2 is used and its reflectance is investigated for a certain arbitrary wavelength, this reflection The factors that determine the ratio are the film thickness d and the refraction angle θ in equation (a).

ところで本発明では、入射角（＝よらない一定の分光透
過率を得ることが要請されるため、従来入射角によって
透過率が変化していた特定波長の光線に対して、その透
過率が入射角によらず常（−一定のものとすることが必
要となる。However, in the present invention, it is required to obtain a constant spectral transmittance that does not depend on the angle of incidence. It is necessary to keep it constant regardless of the

そこで、上記波長の光線に対して、透過率、即ち、これ
に関係する反射率について考えてみると、任意のある反
射率に対し、これを与える固有の位相差δ０が予め決定
されており、従って（ａ）式の右辺が常に固有の位相差
δ０となるよう膜厚ｄと、そこでの屈折角θとを調整す
ることによって、上記波長の光線についての反射率、即
ちこれに対応する透過率を入射角によらず常に一定に維
持することができる。Therefore, if we consider the transmittance, that is, the reflectance related to light rays of the above wavelength, for any given reflectance, the unique phase difference δ0 that gives this is determined in advance, Therefore, by adjusting the film thickness d and the refraction angle θ there so that the right side of equation (a) always has a unique phase difference δ0, the reflectance for the light beam of the above wavelength, that is, the corresponding transmittance. can be kept constant regardless of the angle of incidence.

これについて、第４図をもとじ、（ａ）式を用いて説明
する。先ず、垂直入射光（８）（屈折角Ｃ）について、
ここで上記透過率を与える膜厚ｄｏが、（ａｔ式次に、
斜入射光（９）（屈折角θ２＼０″）について、ここで
上記透過率を与える膜厚ｄが、（ａ）式より、となる。This will be explained based on FIG. 4 and using equation (a). First, regarding the vertically incident light (8) (refraction angle C),
Here, the film thickness do giving the above transmittance is (at formula, then
For oblique incident light (9) (refraction angle θ2\0''), the film thickness d that provides the above transmittance is as follows from equation (a).

尚、この式を屈折の法則を用いて、入射角θ１で表わす
と、 となる。（ル、：空気の屈折率） 従って、基板（６）上の薄膜（７）を入射角θ１（一応
じ（ｃ）式を満足するような膜厚分布に形成すると、上
記波長の光線は入射角によらず常に一定の透過率となる
。Note that when this equation is expressed by the incident angle θ1 using the law of refraction, it becomes as follows. (Le, : refractive index of air) Therefore, if the thin film (7) on the substrate (6) is formed with a film thickness distribution that satisfies the incident angle θ1 (according to equation (c)), the light rays of the above wavelength will be incident The transmittance is always constant regardless of the angle.

尚、上記透過率は、位相差δ０（従って膜厚ｄｏ）を変
えること（＝よって任意に選択することができるが、で
きるだけ高透過率に設定するのが望ましく、この際同時
に、フィルターを透過する波長域全般の光にも良好な分
光特性が発揮できるものである。The above transmittance can be arbitrarily selected by changing the phase difference δ0 (and therefore the film thickness do), but it is desirable to set the transmittance as high as possible. It can exhibit good spectral characteristics even for light in the entire wavelength range.

以上、上記実施例においては、単層膜について述べて来
たものであるが、多層膜を形成する場合でも勿論可能で
あり、この場合、一層毎に上記関係式（ｃ）を満足する
ように膜厚を形成していけばよい。In the above embodiments, a single layer film has been described, but it is of course possible to form a multilayer film, and in this case, it is possible to form a multilayer film so that each layer satisfies the above relational expression (c). All you have to do is increase the film thickness.

また、上記薄膜の製法については、従来より周知の捜′
術、例えば真空蒸着法を用い、点状或は線状蒸発源から
の蒸発量をコントロールすることにより、容易に形成す
ることができる。また、薄膜を形成する物質として、本
実施例ではフッ化マグネシクムを用いたが、これ以外に
、例えば酸化フッ素等を用いてもよい。In addition, regarding the manufacturing method of the above-mentioned thin film, the well-known research
It can be easily formed by using a technique such as a vacuum evaporation method and controlling the amount of evaporation from a point or linear evaporation source. Furthermore, although magnesium fluoride is used as the material for forming the thin film in this embodiment, other materials such as fluorine oxide may also be used.

次に、第５図は、第２図と同様の構成を有する複写機Ｃ
：おいて、本発明の上記フィルター（５）を適用した一
実施例であり、上記フィルター（５）は、レンズ（１１
）から４００１Ｉｌｌｌ＋離れた位置に設置され、長手
方向中央部（５ａ）が光軸（ＩＩＩＩｌと一致させであ
る。Next, FIG. 5 shows a copying machine C having the same configuration as FIG. 2.
: is an example in which the above filter (5) of the present invention is applied, and the above filter (5) has a lens (11
), and the central part (5a) in the longitudinal direction is aligned with the optical axis (IIIl).

上記フィルター（５）における薄膜（７）の膜厚は、上
記（ｃ）式に従った膜厚分布となっており、例えば中央
部（７ａ）から１５６，１１＋＋＋離れた長手方向端部
（７ｂ）での膜厚が、上記中央部（７ａ）での膜厚に比
べ約５．３％高められている。The thickness of the thin film (7) in the filter (5) has a film thickness distribution according to the above formula (c). The film thickness at the central portion (7a) is increased by approximately 5.3% compared to the film thickness at the central portion (7a).

尚、本実施例において、原稿（１つは幅が一’８６４ｆ
ｒａ、レンズ（１１）は焦点距離が２７０１１ｒ！Ａ、
　Ｆ値が４．５のものを用いており、このときの最大半
画角αは１８．６°となっている。In this example, the document (one document has a width of 1'864f)
ra, the focal length of lens (11) is 27011r! A,
A lens with an F value of 4.5 is used, and the maximum half angle of view α at this time is 18.6°.

そして、第３図と同一のりニアへロゲンランプを用いて
感光体ｆ１３ｉ上の中央部（１８ａ）及び端部（１３ｂ
）ｌ二ついて分光特性を測定したところ、第６図に示す
グラフを得た。Then, using the same linear herogen lamp as in FIG.
) When the spectral characteristics were measured using two probes, the graph shown in FIG. 6 was obtained.

このグラフかられかるように、感光体中央部（至）ａ）
及び端部（１３ｂ）に照射される光についての分光特性
Ｅ及びＦは、全く同一となっており、従ってコピ一時に
そのコピー濃度の均一化が図れ、また、カラーコピ一時
にはその演色性の均一化を図ることができる。As can be seen from this graph, the central part of the photoreceptor (to) a)
The spectral characteristics E and F of the light irradiated to the end portion (13b) and the end portion (13b) are completely the same, so that the copy density can be made uniform at the time of copying, and the color rendering property can be made uniform at the time of color copying. It is possible to aim for

尚、本発明のフィルターは、上記実施例においては複写
機に適用したが、これに限定されるものではない。Although the filter of the present invention is applied to a copying machine in the above embodiment, it is not limited thereto.

〔発明の効果〕〔Effect of the invention〕

本発明に係る複写機等のフィルターは、以上の通りの構
成となっており、このフィルターに入射する光の分光特
性がフィルター全域に亘って均一となるような膜厚分布
に形成されているため、複写物の演色性及び濃度の均一
化を格段に高めることができるものである。The filter for a copying machine, etc. according to the present invention has the above-mentioned configuration, and is formed to have a film thickness distribution such that the spectral characteristics of light incident on the filter are uniform over the entire filter area. , it is possible to significantly improve the color rendering properties and density uniformity of copies.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は、従来のフィルターを適用した複写機の光学系
を示す概略図、第２図は従来型フィルターによる分光透
過率の入射角依存性を示すグラフ、第３図は従来型フィ
ルターを適用した複写機における感光体実効光量を示す
グラフ、第４図は本発明に係るフィルターの説明図、第
５図は本発明に係るフィルターが適用された複写機の光
学系を示す概略図、第６図は、本発明に係るフィルター
を適用した複写機における感光体照射光質を示すグラフ
である。 符号説明 ＋１１　Ｑｌ）・・・・・・レンズ　（２）　＋１３１
・・・・・・感光体（５）・・・・・・フィルター　（
６）・・・・・・平板状透明基板（７）・・・・・・薄
膜　（８）・・・・・・垂直入射光（９）・・・・・・
斜入射光　（１２）・・・・・・原稿Ａ、Ｂ・・・・・
・分光透過率（入射角ｏ０．　ａｏｏ）Ｃ・・・・・・
・・・・・・（ハロゲンランプ）連続スペクトル光Ｄ・
・・・・・・・・・・・（感光体）分光感度Ｅ、Ｆ・・
・・・・分光特性（蒸着フィルター中央部、端部） 第３図 第４図 第５図 ２ 第６図Figure 1 is a schematic diagram showing the optical system of a copying machine using a conventional filter, Figure 2 is a graph showing the dependence of spectral transmittance on the angle of incidence using a conventional filter, and Figure 3 is a graph using a conventional filter. FIG. 4 is an explanatory diagram of the filter according to the present invention, FIG. 5 is a schematic diagram showing the optical system of a copying machine to which the filter according to the present invention is applied, and FIG. The figure is a graph showing the quality of light irradiated onto a photoreceptor in a copying machine to which a filter according to the present invention is applied. Code explanation +11 Ql)...Lens (2) +131
...Photoreceptor (5) ...Filter (
6)... Flat transparent substrate (7)... Thin film (8)... Vertical incident light (9)...
Oblique incident light (12)...Original A, B...
・Spectral transmittance (incident angle o0. aoo) C...
・・・・・・(Halogen lamp) Continuous spectrum light D・
・・・・・・・・・・・・(Photoreceptor) Spectral sensitivity E, F...
...Spectral characteristics (center and edge of vapor deposited filter) Fig. 3 Fig. 4 Fig. 5 Fig. 2 Fig. 6

Claims (1)

【特許請求の範囲】 複写機等の光学系の光源から感材に至る光路中に設置さ
れ、平板状透明基板上に薄膜が形成されたフィルターに
おいて、この薄膜の膜厚ｄは、これに入射する光線の入
射角θｌに対して、ｒＬ。 となるような膜厚分布に形成されていることを特徴とす
る複写機等のフィルター。[Claims] In a filter that is installed in the optical path from the light source of an optical system such as a copying machine to a sensitive material, and has a thin film formed on a flat transparent substrate, the thickness d of this thin film is rL for the incident angle θl of the ray. A filter for copying machines, etc., characterized by being formed with a film thickness distribution such that:
JP579984A 1984-01-18 1984-01-18 Filter of copying machine or the like Granted JPS60150005A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP579984A JPS60150005A (en) 1984-01-18 1984-01-18 Filter of copying machine or the like

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP579984A JPS60150005A (en) 1984-01-18 1984-01-18 Filter of copying machine or the like

Publications (2)

Publication Number Publication Date
JPS60150005A true JPS60150005A (en) 1985-08-07
JPH0464056B2 JPH0464056B2 (en) 1992-10-13

Family

ID=11621124

Family Applications (1)

Application Number Title Priority Date Filing Date
JP579984A Granted JPS60150005A (en) 1984-01-18 1984-01-18 Filter of copying machine or the like

Country Status (1)

Country Link
JP (1) JPS60150005A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6159374A (en) * 1984-08-30 1986-03-26 Canon Inc Color electrophotographic device
JPS646905A (en) * 1987-06-30 1989-01-11 Hoya Corp Laser light reflecting filter

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6159374A (en) * 1984-08-30 1986-03-26 Canon Inc Color electrophotographic device
JPS646905A (en) * 1987-06-30 1989-01-11 Hoya Corp Laser light reflecting filter

Also Published As

Publication number Publication date
JPH0464056B2 (en) 1992-10-13

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