JP2511833B2 - Phase diffuser - Google Patents

Phase diffuser

Info

Publication number
JP2511833B2
JP2511833B2 JP29046589A JP29046589A JP2511833B2 JP 2511833 B2 JP2511833 B2 JP 2511833B2 JP 29046589 A JP29046589 A JP 29046589A JP 29046589 A JP29046589 A JP 29046589A JP 2511833 B2 JP2511833 B2 JP 2511833B2
Authority
JP
Japan
Prior art keywords
plane
plane portion
pattern
minute
phase
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
JP29046589A
Other languages
Japanese (ja)
Other versions
JPH03150538A (en
Inventor
章市 山崎
寛 松居
望 北岸
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.)
Canon Inc
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Priority to JP29046589A priority Critical patent/JP2511833B2/en
Priority to US07/609,726 priority patent/US5124839A/en
Publication of JPH03150538A publication Critical patent/JPH03150538A/en
Application granted granted Critical
Publication of JP2511833B2 publication Critical patent/JP2511833B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は位相型拡散板に関し、例えば写真用カメラ等
においてファインダー像を形成する焦点板(ピント板)
として用いた場合、所定の拡散特性を有し、良好なるフ
ァインダー像の観察が可能な位相型拡散板に関するもの
である。
TECHNICAL FIELD The present invention relates to a phase type diffusion plate, and for example, a focusing plate (focus plate) for forming a finder image in a photographic camera or the like.
The present invention relates to a phase type diffusion plate having a predetermined diffusion characteristic and capable of observing a good finder image.

(従来の技術) 従来より光学的に透明な基板面上に一定の高さの所定
形状の微細パターンを複数個形成し、該微細パターンを
通過する光束に他の光束に対して位相差を付与して所定
の拡散特性を持たせた位相型拡散板が種々と提案されて
いる。
(Prior Art) Conventionally, a plurality of fine patterns having a predetermined height and a predetermined shape are formed on an optically transparent substrate surface, and a light beam passing through the fine pattern is given a phase difference with respect to other light beams. Various phase-type diffusers having predetermined diffusion characteristics have been proposed.

このうち入射光束に対して位相差0と所定の位相差θ
の全体として2つの位相差より成るバイレベルの微小パ
ターンより成る位相型拡散板が例えば特開昭55−70827
号公報や特開昭62−269157号公報で提案されている。
Of these, the phase difference 0 with respect to the incident light flux and a predetermined phase difference θ
As a whole, a phase type diffusion plate composed of a bi-level fine pattern composed of two phase differences is disclosed in, for example, Japanese Patent Laid-Open No. 55-70827.
Japanese Patent Laid-Open No. 62-269157.

又、本出願人は特願昭63−134127号において入射光束
に対して位相差0と位相差θ1,θ2の全体として3つの
位相差を付与する円形、楕円等のパターンの3レベルの
平面部A,B,Cより成る位相型拡散板を提案している。同
公報において厚さの低い平面部より順にA,B,Cとしたと
き平面部は基板(基準面)に相当し、他の平面部B,Cの
高さは各々異なり、平面部A,B,Cは各々入射光束に対し
て異った位相差を付与している。これにより各々位相差
を異にする3レベルの位相型拡散板を構成している。
In addition, the applicant of the present invention has disclosed in Japanese Patent Application No. 63-134127 that a three-level plane portion having a pattern of a circle, an ellipse, etc., which gives three phase differences as a whole to the incident light beam with a phase difference of 0 and phase differences θ1 and θ2. A phase diffuser consisting of A, B and C is proposed. In the publication, when the plane portions having a smaller thickness are referred to as A, B, and C in this order, the plane portion corresponds to the substrate (reference plane), and the heights of the other plane portions B and C are different from each other. , C respectively give different phase differences to the incident light flux. This constitutes a three-level phase-diffusion plate having different phase differences.

(発明が解決しようとする問題点) バイレベルの位相型拡散板は焦点板として撮影系に用
いたとき、ファインダー像に色付きや明るさムラが生じ
てきて良好なる観察が難しいという問題点があった。
(Problems to be Solved by the Invention) When a bi-level phase-diffusion plate is used in a photographing system as a reticle, there is a problem that coloration and brightness unevenness are generated in a finder image and it is difficult to perform good observation. Was.

又、望遠レンズや接写レンズ等の標準レンズと瞳位置
が大きく異っているような撮影レンズを用いて、絞りを
小絞りにしたときにはファインダー視野の中心に0次回
折光と同じ色を有するスポットが現われてくるという問
題点があった。
When a small aperture is used with a taking lens whose pupil position is greatly different from a standard lens such as a telephoto lens or a close-up lens, a spot having the same color as the 0th-order diffracted light is formed at the center of the finder field. There was a problem that appeared.

これに対して前述した特願昭63−134127号で提案した
3レベルの位相型拡散板でこれらの問題点を解決し、色
ムラがなく、しかも開放時の周辺光量が多い良好なるフ
ァインダー像の観察を可能としている。
On the other hand, the three-level phase-diffusion plate proposed in the above-mentioned Japanese Patent Application No. 63-134127 solves these problems and produces a good viewfinder image with no color unevenness and a large amount of peripheral light at the time of opening. It is possible to observe.

本発明は本出願人が先に提案した3レベルの位相型拡
散板を更に改良し、即ち基板面上に設ける所定形状の複
数の微細な全体として3レベルの平面部(パターン)の
構成を適切に設定することにより、開放時の色ムラが良
好に補正し、又周辺光量を十分多くした良好なる拡散特
性を有し、ファインダー系に適用したときファインダー
像の良好なる観察が可能な位相型拡散板の提供を目的と
する。
The present invention further improves the three-level phase-diffusion plate previously proposed by the present applicant, that is, the structure of a three-level plane portion (pattern) as a plurality of fine shapes of a predetermined shape provided on the substrate surface is suitable. By setting to 1, the color unevenness at the time of opening is corrected well, and it has good diffusion characteristics with a sufficient amount of ambient light, and when applied to a viewfinder system, it is a phase type diffusion that enables good observation of the viewfinder image. For the purpose of providing boards.

(問題点を解決するための手段) 本発明の位相型拡散板は、基板面に全体として3種類
の高さの微細パターンより成る平面部を配置した単位パ
ターン領域を複数個所定の繰り返しピッチで配置し、該
平面部を利用して入射光束に所定の位相差を付与するこ
とにより回折又は/及び散乱させ所望の拡散特性を得る
際、該平面部を上に向けたときの高さの低い方から順に
平面部A,B,Cとし、該平面部Bを基準面としたとき、該
平面部A及び平面部Cを少なくとも2種類の大きさの微
小パターンより構成したことを特徴としている。
(Means for Solving Problems) The phase-diffusion plate of the present invention has a plurality of unit pattern areas in which a plane portion composed of fine patterns of three kinds of heights is arranged on the substrate surface as a whole at a predetermined repeating pitch. The height of the flat portion is low when the flat portion is faced up when the flat portion is arranged and the desired light diffusion property is obtained by diffracting and / or scattering by imparting a predetermined phase difference to the incident light flux using the flat portion. When the plane portions A, B, and C are formed in this order from the one side and the plane portion B is used as a reference plane, the plane portion A and the plane portion C are constituted by at least two types of minute patterns.

(実施例) 第1〜第8図は各々本発明の第1〜第8実施例の単位
パターン領域内の要部概略図である。
(Embodiment) FIGS. 1 to 8 are schematic views of main parts in a unit pattern area of first to eighth embodiments of the present invention.

本実施例ではいずれも単位パターン領域を架空の正6
角形とし(実際にはこのような6角形の線は存在しな
い。)該単位パターン領域を複数個、所定の繰り返しピ
ッチTで配置したときの1つの単位パターン領域を示し
ている。
In each of the embodiments, the unit pattern area is a fictitious regular 6
A polygon is shown (actually, such a hexagonal line does not exist), and one unit pattern area is shown when a plurality of the unit pattern areas are arranged at a predetermined repeating pitch T.

同図では単位パターン領域の格子内に全体として3つ
の高さより成る平面部A,B,Cを設け、これらのうち黒く
塗った平面部Aと白い円形の平面部Cはいずれも大きさ
の異なる複数の互いに独立の微小パターン(円形)より
成っている。
In the figure, plane portions A, B, and C each having three heights are provided in the lattice of the unit pattern area as a whole. Of these, the black-painted plane portion A and the white circular plane portion C have different sizes. It is composed of a plurality of independent micro patterns (circles).

同図において平面部Bは地続きのパターンであり、黒
く塗った平面部Aは平面部B(基準面B)に対して凹部
のパターンより成り、白い円形の平面部Cは平面部Bに
対して凸部のパターンより成っている。平面部A,Cは平
面部Bの材質と同一、又は異った材質より形成されてい
る。尚、同図にはサンプル番号を付している。
In the figure, the plane portion B is a continuous pattern, the black-colored plane portion A is a pattern of recesses with respect to the plane portion B (reference plane B), and the white circular plane portion C is relative to the plane portion B. It consists of a convex pattern. The flat portions A and C are made of the same material as or different from the material of the flat portion B. Incidentally, sample numbers are attached to the figure.

そしてこれら3つの平面部A,B,Cは入射光束に対して
各々異った位相差を付与し、回折又は/及び散乱させる
ことにより所望の拡散特性を得ている。これにより所謂
3レベルの位相型拡散板を構成している。
Then, these three plane portions A, B, C give different phase differences to the incident light flux, and diffract or / and scatter to obtain desired diffusion characteristics. This constitutes a so-called three-level phase-diffusion plate.

尚、平面部A,Cのパターンは円形の他に楕円形、長円
形、多角形等どのような形成で構成しても良く、又平面
部Aを凸部のパターン、平面部Cを凹部のパターンより
構成しても良い。
In addition, the pattern of the plane portions A and C may be formed in any shape such as an ellipse, an oval, or a polygon in addition to the circular shape, and the plane portion A may be a convex pattern and the plane portion C may be a concave pattern. You may comprise from a pattern.

本実施例では平面部A,Cの双方を少なくとも2種類の
大きさの異なる微小パターンより構成することにより、
開放時の色むらを良好に補正すると共に高次の回折光を
多くし、開放時の周辺光量をあげ良好なる拡散特性を得
ている。
In this embodiment, both the plane portions A and C are composed of at least two kinds of minute patterns having different sizes.
Color unevenness at the time of opening is satisfactorily corrected, high-order diffracted light is increased, and the amount of peripheral light at the time of opening is increased to obtain good diffusion characteristics.

本実施例においては平面部Aのパターンのうち1番目
又は2番目に大きなパターン(円)と平面部Cのパター
ンのうち1番目又は2番目に大きなパターン(円)が第
9〜第12図に示すように輪帯状になるように配置してい
る。
In the present embodiment, the first or second largest pattern (circle) of the pattern of the plane portion A and the first or second largest pattern (circle) of the pattern of the plane portion C are shown in FIGS. 9 to 12. As shown, they are arranged in a ring shape.

尚、第9〜第12図は平面部A,B,Cを上に向けて見たと
きの単位パターン領域を示している。ここで輪帯状とは
単位パターン領域の中心と中心として描かれた架空の円
上又はその付近に平面部A又は平面部Cのうちの1番目
又は2番目に大きな円の中心が存在することである。そ
してこの描かれる架空の円の半径をRとしたとき半径0.
6Rから1.4Rの間に平面部A又は平面部Cのうちの1番目
又は2番目に大きな円の中心が存在するようにしてい
る。
9 to 12 show unit pattern areas when the plane portions A, B and C are directed upward. Here, the annular shape means that the center of the first or second largest circle of the plane portion A or the plane portion C exists on or near the center of the unit pattern area and an imaginary circle drawn as the center. is there. And when the radius of this fictitious circle is R, the radius is 0.
Between 6R and 1.4R, the center of the first or second largest circle of plane A or plane C exists.

尚、第9〜第12図において黒い円は平面部Cであり、
該平面部Cの微小パターンは平面部(基準面)Bに対し
凸部又は凹部となっている。白い円は平面部Aの微小パ
ターンで平面部Bに対し凹部又は凸部となっている。
In addition, in FIGS. 9 to 12, the black circle is the plane portion C,
The minute pattern of the plane portion C is a convex portion or a concave portion with respect to the plane portion (reference surface) B. The white circle is a minute pattern of the plane portion A and is a concave portion or a convex portion with respect to the plane portion B.

これにより(平面部A−平面部B)の拡散光と(平面
部B−平面部C)の拡散光がバランス良く強め合い又は
弱め合い点対称的な自然の拡散特性を得ている。
As a result, the diffused light of the plane portion A-the plane portion B and the diffused light of the plane portion B-the plane portion C are strengthened or weakened in a well-balanced manner to obtain a natural point-symmetrical diffusion characteristic.

特に本実施例では単位パターン領域が6角形で、その
各項点に平面部Aの1番目又は2番目に大きい基準面
(平面部B)に対し凹状の微小パターンを置き、平面部
Cの1番目又は2番目に大きい基準面(平面部B)に対
し凸状の微小パターンを第9図に示すように6角形の頂
点方向に置いている。これにより拡散板としてのボケ味
を良くし、又開放時の周辺光量の向上を図っている。
Particularly, in this embodiment, the unit pattern area is hexagonal, and a concave minute pattern is placed on the first or second largest reference plane (flat surface portion B) of the flat surface portion A at each item point, and A convex fine pattern is placed in the direction of the apex of the hexagon with respect to the second or second largest reference plane (planar portion B), as shown in FIG. This improves the blurring effect of the diffuser plate and improves the amount of ambient light when the aperture is open.

第10図では平面部Cのうち1番目又は2番目に大きい
凸状の微小パターンを6角形の頂点と頂点の中間の方向
に配置しており、これにより開放時の色むらを良好に補
正している。
In FIG. 10, the 1st or 2nd largest convex minute pattern of the plane portion C is arranged in the direction of the vertex of the hexagon and in the middle of the vertex, whereby the color unevenness at the time of opening is corrected well. ing.

第11,第12図は平面部Aの1番目又は2番目に大きい
凹状の微小パターンを中心にその回りに平面部Cの1番
目又は2番目に大きい凸状の微小パターンを配置してお
り、これにより開放時の色むらを良好に補正している。
In FIGS. 11 and 12, the first or second largest concave minute pattern of the plane portion A is centered and the first or second largest convex minute pattern of the plane portion C is arranged around it. As a result, color unevenness at the time of opening is corrected well.

次に本実施例の位相型拡散板の光学特性を数式を用い
て説明する。
Next, the optical characteristics of the phase-diffusion plate of this embodiment will be described using mathematical expressions.

本実施例における3−レベル位相型拡散板(θx,
θ)方向の回折光uは入射光束の波長をλ、基板の材
質のx,y方向の屈折率を各々NX,NY、NX=sinθX/λ、NY
=sinθY/λ、拡散板上の点(x,y)に於ける位相分布を
φ(x,y)とすると u(Nx,Ny)〜∫∫exp(−i φ(x,y))・exp[ −i2π(Nx・x+Ny・y)]dxdy の様に位相分布のフーリエ変換として求められる。
The three-level phase diffuser (θ x ,
The diffracted light u in the θ y ) direction has a wavelength of the incident light beam of λ, and the refractive indices of the substrate material in the x and y directions are N X , N Y , and N X = sin θ X / λ, N Y, respectively.
= Sin θ Y / λ, and the phase distribution at point (x, y) on the diffuser is φ (x, y) u (N x , N y ) 〜∫∫exp (−i φ (x, y) )) · exp [-i2π (N x · x + N y · y)] is determined as the Fourier transform of the phase distribution as a dxdy.

拡散板上の平面部Aに対する平面部Bの高さをdB、平
面部Cの高さをdCとすると、各平面部の位相は φ(x,y)=0、 φ(x,y)=2π(n−1)・dB/λ、 φ(x,y)=2π(n−1)・dC/λ と表わされ、各平面部の、全体に対する面積比をそれぞ
れSA,SB,SCとすると(ここでSA+SB+SC=1である)、
直進成分である0次回折光の強度IOは上式に (θx)=(0,0) を代入して で計算される。上式を整理すると、 IO=1−2SASB・{1−cos(2π(n −1)・dB/λ)} −2SASC・{1−cos(2π(n −1)・dC/λ)} −2SBSC・{1−cos(2π(n −1)・(dC−dB)/λ)} となる。
Assuming that the height of the flat portion B with respect to the flat portion A on the diffuser plate is d B and the height of the flat portion C is d C , the phase of each flat portion is φ (x, y) A = 0, φ (x, y) B = 2π (n−1) · d B / λ, φ (x, y) C = 2π (n−1) · d C / λ, and the area ratio of each plane portion to the whole is Let S A , S B , S C (where S A + S B + S C = 1),
The intensity I O of the 0th-order diffracted light, which is a straight component, is obtained by substituting (θ x , θ y ) = (0,0) into the above equation. Calculated by Organizing the above equation, I O = 1−2S A S B · {1-cos (2π (n −1) · d B / λ)} −2S A S C · {1−cos (2π (n −1 ) · d C / λ)} -2S B S C · {1-cos (2π (n -1) · (d C -d B) / λ) becomes}.

この式で、 [2SASB・{1−cos(2π(n −1)・dB/λ)}] の項は平面部A及びBを透過してきた光波が干渉しあっ
て側方に回折される拡散光(0次以外の回折光)を意味
しており、以下の項は同様に、平面部AとC或は平面部
BとCを透過してきた光波が干渉しあって側方に回折さ
れる拡散光を意味する。
In this formula, the [2S A S B · {1 -cos (2π (n -1) · d B / λ)}] section side interfere with each other is the light waves transmitted through the flat portion A and B of It means diffused light that is diffracted (diffracted light other than the 0th order). Similarly, the following terms are sideways due to the interference of the light waves that have passed through the plane portions A and C or the plane portions B and C. It means diffused light that is diffracted into.

全拡散光は以上三項の合計であり、従って直進成分で
ある0次回折光の強度は上式の様に全光量1から全拡散
光を差し引いた値となる。
The total diffused light is the sum of the above three terms. Therefore, the intensity of the 0th-order diffracted light, which is a straight component, is a value obtained by subtracting the total diffused light from the total light amount 1 as in the above equation.

この様に全拡散光は平面部AとB、平面部AとC、更
に平面部BとCを透過してきた光波の拡散光三項の重ね
あわせによって決まる。この為本実施例では単位パター
ン領域のピッチや平面部Aと平面部Cの微小パターンの
配置、平面部B及びCの高さdB及びdC、そして面積比
SA,SB及びSCを適切に選び、これにより色を打ち消しあ
って全拡散光の分光特性をフラットにして0次回折光の
強度の分光特性も同様にフラットにしている。
As described above, the total diffused light is determined by the superposition of the three terms of the diffused light of the light waves transmitted through the plane portions A and B, the plane portions A and C, and the plane portions B and C. Therefore the arrangement of the fine pattern of pitch and flat portion A and the plane portion C of the unit pattern area in this embodiment, the planar portion B and C of the height d B and d C, and the area ratio
S A , S B, and S C are appropriately selected, whereby colors are canceled out to make the spectral characteristics of all diffused light flat and the spectral characteristics of the intensity of 0th-order diffracted light flat as well.

本実施例においては拡散板としての開放時の色むらを
なくし、ボケ味を良好にする為に0次回折光の強度及び
そのときの色ができるだけ弱く、かつ色が白色に近くな
るように平面部A,B,Cのパターンを設定している。
In this embodiment, in order to eliminate the color unevenness when the diffuser plate is opened and to improve the blurring effect, the intensity of the 0th-order diffracted light and the color at that time are as weak as possible, and the flat surface portion is close to white. A, B, and C patterns are set.

例えば平面部A,B,Cの面積比と(平面部A−平面部
B)及び(平面部B−平面部C)の位相差の組み合わせ
が所定の範囲内になるようにしている。
For example, the combination of the area ratio of the plane portions A, B, and C and the phase difference of (plane portion A-plane portion B) and (plane portion B-plane portion C) is set within a predetermined range.

即ち、平面部Bの面積比SBが40〜60%の範囲内となる
ようにし平面部A,B,Cのうち一番面積比が大きくなるよ
うに設定している。この為、平面部Bを地続きのパター
ンとし製作を容易にしている。これにより色むらのない
ボケ味の良い位相型拡散板を得ている。
That is, the area ratio SB of the flat surface portion B is set to fall within the range of 40 to 60% so that the area ratio of the flat surface portions A, B, C is the largest. Therefore, the flat portion B is formed in a continuous pattern to facilitate the production. As a result, a phase-type diffuser plate with no color unevenness and good blurring is obtained.

特に本実施例では0次光の強度及びそのときの色がで
きるだけ弱く、かつ色が白色に近くなるように平面部A,
Cの面積比をSA,SC、平面部Aと平面部Bの深さの絶対値
をd1、平面部Bと平面部Cの深さの絶対値をd2、基板の
材質のd線に対する屈折率をndとしたとき なる条件を満足するようにしている。これらの条件を外
れると開放時に中心付近で色むらが目立ち、又拡散板と
してボケ味の良い観察をするのが難しくなってくる。
In particular, in this embodiment, the plane portion A, so that the intensity of the 0th-order light and the color at that time are as weak as possible and the color is close to white,
The area ratio of C is SA, SC, the absolute value of the depth of the plane portion A and the plane portion B is d 1 , the absolute value of the depth of the plane portion B and the plane portion C is d 2 , and the d-line of the substrate material is When the refractive index is nd I try to satisfy the following conditions. If these conditions are not satisfied, color unevenness will be noticeable near the center when opened, and it will be difficult for the diffuser plate to be observed with good blur.

尚、本実施例において面積比SA,SB,SCをSA+SB+SC=
1としたとき、面積比SAと面積比SCのうち大きい方の面
積比に係る平面部を3種類以上の微小パターンより構成
すれば更に開放時の色むらと周辺光量を良好にすること
ができるので好ましい。
In this embodiment, the area ratio SA, SB, SC is SA + SB + SC =
If the area ratio SA and the area ratio SC are larger than each other and the flat surface portion is composed of three or more kinds of minute patterns, it is possible to further improve the color unevenness and the peripheral light amount at the time of opening. Therefore, it is preferable.

次に本実施例において好ましい単位パターン領域及び
微小パターンの構成について順次説明する。
Next, preferred unit pattern areas and minute pattern configurations in this embodiment will be described in order.

まず本実施例において、前記単位パターン領域を複数
個設ける際の繰り返しピッチをTとしたとき、即ち平面
部Aと平面部Cの双方が同一の繰り返しピッチを有し、
そのときの繰り返し周期をTとしたとき 15μm≦T≦65μm ‥‥(2) なる条件を満足することが良い。
First, in the present embodiment, when the repeating pitch when a plurality of the unit pattern areas is provided is T, that is, both the plane portion A and the plane portion C have the same repeating pitch,
When the repetition cycle at that time is T, it is preferable that the condition of 15 μm ≦ T ≦ 65 μm (2) is satisfied.

平面部Aと平面部Cの周期Tが同一でないとモアレの
発生が多くなる。そして周期Tが15μmより小さいと単
位パターン領域内の微小パターンが小さくなりすぎ製作
が難しくなる。又周期Tが65μmより大きいとピント板
として用いたときファインダー像の観察の際に粒状性が
目立ってくるので良くない。
If the periods T of the plane portion A and the plane portion C are not the same, moire is often generated. When the period T is smaller than 15 μm, the minute pattern in the unit pattern area becomes too small, which makes it difficult to manufacture. Further, if the period T is larger than 65 μm, graininess becomes noticeable when observing a finder image when used as a focusing plate, which is not preferable.

次に前記平面部Aと平面部Cは共に最大長4μm以上
の少なくとも1つの微小パターンを有していることが良
い。
Next, it is preferable that both the plane portion A and the plane portion C have at least one minute pattern having a maximum length of 4 μm or more.

これは平面部Aと平面部Cの双方の微小パターンの直
径が全て4μm以下であると高次の回折光が強くなるが
低次の回折光が弱くなりすぎ、ピント板として用いたと
き暗くなってくるので良くない。又ボケ味もボケは大き
いが中心に芯があるボケとなってくるので良くない。
This is because when the diameters of the minute patterns on both the plane portion A and the plane portion C are all 4 μm or less, the high-order diffracted light becomes strong, but the low-order diffracted light becomes too weak and becomes dark when used as a focusing plate. It's not good because it comes. In addition, the bokeh taste is also large, but it is not good because the center has a core.

特に本実施例において平面部Aと平面部Cのうち最大
円の直径を2RM、該最大円を含む平面部A又は平面部C
の繰り返し周期をTMとしたとき 0.2≦2RM/TM ‥‥(3) を満足するパターン(円)が少なくとも1つ以上平面部
A又は平面部Cに存在するように構成するのが良い。こ
れによれば、より拡散特性及びボケ味の良い明るいピン
ト板が得られる。
Particularly in this embodiment, the diameter of the largest circle of the plane portions A and C is 2R M , and the plane portion A or the plane portion C including the largest circle.
It is preferable configured to repeatedly cycle T M and then 0.2 ≦ 2R M / T M ‥‥ when the (3) pattern (circle) which satisfies exists in at least one plane part A or plane part C of . According to this, it is possible to obtain a bright focusing plate having better diffusion characteristics and better blurring.

次に本実施例において中心部分の色と周辺部分の色の
差を更に小さくするには、前記平面部A又は平面部Cの
微小パターンと該平面部A又は平面部Cの他の微小パタ
ーンの境界線どうしの距離のうち最小の距離をD、該平
面部Aと平面部Cの微小パターンのうち最小長の微小パ
ターンの長さ(直径)をLminとしたとき |D/Lmin|≦1 ‥‥(4) なる条件を満足することが良い。
Next, in the present embodiment, in order to further reduce the difference between the color of the central portion and the color of the peripheral portion, the fine pattern of the plane portion A or the plane portion C and another fine pattern of the plane portion A or the plane portion C are to be formed. When the minimum distance of the distances between the boundary lines is D and the length (diameter) of the minimum minute pattern of the minute patterns of the plane portions A and C is L min | D / L min | ≦ It is better to satisfy the condition 1 ... (4).

この条件を外れてパターンとパターンが離れすぎてく
ると開放のとき色むらが生じてくるので良くない。
If this condition is not satisfied and the patterns are separated from each other too much, color unevenness will occur when the patterns are opened, which is not good.

又、本実施例では第13図に示すようにパターンを形成
する際のエッジ部分を積極的にダラす(傾ける)ことに
より、開放のときの色むらを更に良好にしている。
Further, in this embodiment, as shown in FIG. 13, the edge portion when forming a pattern is positively blunted (tilted) to further improve the color unevenness at the time of opening.

即ち本実施例においては、前記平面部A又は平面部C
の微小パターンと前記平面部Bのエッジ部分における段
差の3割の高さと7割の高さの点を結んだ線が平面部B
となす角度をθ、該平面部Bから遠ざかるに従って平
面部A又は平面部Cの微小パターンの径が小さくなる場
合は絶対値の小さい角度をθ、大きくなる場合は絶対
値の大きい角度をθとしたとき 20゜≦θ≦100゜ ‥‥(5) なる条件を満足するようにしている。
That is, in this embodiment, the plane portion A or the plane portion C is used.
The line connecting the minute pattern of 30% and the height of 70% of the step at the edge of the flat portion B is the flat portion B.
And angle theta Z forming, flat portion if the diameter of the fine pattern of the flat portion A or planar portion C becomes smaller as the distance from the B small angle absolute value theta Z, may become larger the larger the angle of the absolute value When θ Z is set, the condition of 20 ° ≦ θ Z ≦ 100 ° (5) is satisfied.

この条件式(5)の下限値を外れると開放のとき中心
付近の色が赤っぽくなり全体として赤みがかかってく
る。又上限値を外れると段差部分が逆テーパーとなり型
を作り、整形品に転写したときの転写精度が低下してく
るので良くない。
If the lower limit value of the conditional expression (5) is not satisfied, the color near the center becomes reddish when opened, and the overall color becomes reddish. If the upper limit is exceeded, the stepped portion becomes an inverse taper, a mold is formed, and the transfer accuracy when transferred to a shaped product is deteriorated, which is not preferable.

次に表1〜表8に本発明の実施例1〜8の数値のデー
タを示す。
Next, Tables 1 to 8 show numerical data of Examples 1 to 8 of the present invention.

表1〜表8は正6角形の単位パターン領域に微小パタ
ーンのサンプルナンバーNo、位置座標X,Y(正6角形の
中心を(0,0)としている。)平面部Bを基準としたと
きの位相差D(深さ)及びパターンの半径Rを示してい
る。
Tables 1 to 8 show sample numbers No and position coordinates X and Y of the minute pattern in the unit pattern area of the regular hexagon (when the center of the regular hexagon is (0, 0)) with reference to the plane portion B. Shows the phase difference D (depth) and the radius R of the pattern.

尚、以上の実施例において位相型拡散板をピント板と
して用いた場合を示したが、本発明の位相型拡散板は所
定の拡散特性を有した光学フィルターとして用いること
もできる。
Although the case where the phase type diffusion plate is used as the focusing plate has been shown in the above embodiments, the phase type diffusion plate of the present invention can also be used as an optical filter having a predetermined diffusion characteristic.

又、単位パターン領域の繰り返し形状を正6角形とし
たが形状は6角形に限らず4角形、3角形等どのような
形状であっても良い。
Further, although the repeating shape of the unit pattern area is a regular hexagon, the shape is not limited to a hexagon, and may be any shape such as a tetragon and a triangle.

(発明の効果) 本発明によれば前述の如く基板面上に所定形状の複数
の微細パターンより成る高さの異なる3種類の平面部を
各々独立に設けることにより、例えばファインダー系の
ピント板として用いたとき開放時の色むらが少なく、か
つ周辺光量の低下が少なく、しかもボケ味の良い、所定
の拡散特性を有した位相型拡散板を達成することができ
る。
(Effects of the Invention) According to the present invention, as described above, three kinds of flat portions having different heights and each having a plurality of fine patterns of a predetermined shape are independently provided on the surface of the substrate. When used, it is possible to achieve a phase-type diffuser plate which has little color unevenness when opened, little decrease in the amount of peripheral light, and good blurring and which has a predetermined diffusion characteristic.

【図面の簡単な説明】[Brief description of drawings]

第1図〜第8図は各々本発明の第1〜第8実施例の単位
パターン領域の要部概略図、第9〜第12図は各々本発明
に係る位相型拡散板の単位パターン領域の説明図、第13
図は本発明の位相型拡散板の3つの平面部A,B,Cの断面
説明図である。 図中、A,B,Cは各々平面部を示している。
1 to 8 are schematic views of a main part of a unit pattern area of each of the first to eighth embodiments of the present invention, and FIGS. 9 to 12 are each a unit pattern area of a phase type diffusion plate according to the present invention. Explanatory drawing, thirteenth
The figure is a cross-sectional explanatory view of three plane portions A, B, and C of the phase type diffusion plate of the present invention. In the figure, A, B, and C each represent a plane portion.

Claims (6)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】基板面に全体として3種類の高さの微細パ
ターンより成る平面部を配置した単位パターン領域を複
数個所定の繰り返しピッチで配置し、該平面部を利用し
て入射光束に所定の位相差を付与することにより回折又
は/及び散乱させ所望の拡散特性を得る際、該平面部を
上に向けたときの高さの低い方から順に平面部A,B,Cと
し、該平面部Bを基準面としたとき、該平面部A及び平
面部Cを少なくとも2種類の大きさの微小パターンより
構成したことを特徴とする位相型拡散板。
1. A plurality of unit pattern areas, each of which has a plane portion composed of fine patterns of three different heights as a whole, are arranged on a substrate surface at a predetermined repeating pitch, and the plane portion is used to predetermined an incident light beam. When a desired diffusion characteristic is obtained by diffracting and / or scattering by imparting a phase difference of, the plane portions A, B, and C are arranged in order from the one having the lowest height when the plane portion is directed upward, and the plane A phase type diffusion plate, characterized in that when the section B is used as a reference plane, the plane section A and the plane section C are composed of at least two types of minute patterns.
【請求項2】前記単位パターン領域を複数個設ける際の
繰り返しピッチをTとしたとき 15μm≦T≦65μm なる条件を満足することを特徴とする請求項1記載の位
相型拡散板。
2. The phase type diffuser plate according to claim 1, wherein a condition that 15 μm ≦ T ≦ 65 μm is satisfied, where T is a repeating pitch when a plurality of the unit pattern regions are provided.
【請求項3】前記平面部A,Cのうち一方の平面部を前記
平面部Bに対して凸状の独立のパターン、他方の平面部
を凹状の独立のパターンより構成したことを特徴とする
請求項1記載の位相型拡散板。
3. One of the plane portions A and C is formed by a convex independent pattern with respect to the plane portion B, and the other flat portion is formed by a concave independent pattern. The phase type diffusion plate according to claim 1.
【請求項4】前記平面部Aと平面部Cは共に最大長4μ
m以上の少なくとも1つの微小パターンを有しているこ
とを特徴とする請求項1記載の位相型拡散板。
4. The flat portion A and the flat portion C both have a maximum length of 4 μm.
The phase type diffuser plate according to claim 1, wherein the phase type diffuser plate has at least one minute pattern of m or more.
【請求項5】前記平面部A又は平面部Cの微小パターン
と該平面部A又は平面部Cの他の微小パターンの境界線
どうしの距離のうち最小の距離をD、該平面部Aと平面
部Cの微小パターンのうち最小長の微小パターンの長さ
(直径)をLminとしたとき |D/Lmin|≦1 なる条件を満足することを特徴とする請求項1又は請求
項3記載の位相型拡散板。
5. The minimum distance of the distances between boundary lines between the minute pattern of the plane portion A or the plane portion C and another minute pattern of the plane portion A or the plane portion C is D, and the plane portion A and the plane 4. The condition of | D / L min | ≦ 1 is satisfied when the length (diameter) of the minimum length minute pattern among the minute patterns of the portion C is L min. Phase diffuser plate.
【請求項6】前記平面部A又は平面部Cの微小パターン
と前記平面部Bのエッジ部分における段差の3割の高さ
と7割の高さの点を結んだ線が平面部Bとなす角度をθ
、該平面部Bから遠ざかるに従って平面部A又は平面
部Cの微小パターンの径が小さくなる場合は絶対値の小
さい角度をθ、大きくなる場合は絶対値の大きい角度
をθとしたとき 20゜≦θ≦100゜ なる条件を満足することを特徴とする請求項1又は請求
項3記載の位相型拡散板。
6. An angle formed by a line connecting the minute pattern of the flat surface portion A or the flat surface portion C and the points of 30% and 70% of the step at the edge portion of the flat surface portion B with the flat surface portion B. Θ
Z , when the diameter of the minute pattern of the plane portion A or the plane portion C becomes smaller as it goes away from the plane portion B, an angle having a small absolute value is θ Z , and when it is larger, an angle having a large absolute value is θ Z. The phase type diffusion plate according to claim 1 or 3, which satisfies the condition of 20 ° ≤ θ Z ≤ 100 °.
JP29046589A 1989-11-08 1989-11-08 Phase diffuser Expired - Fee Related JP2511833B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP29046589A JP2511833B2 (en) 1989-11-08 1989-11-08 Phase diffuser
US07/609,726 US5124839A (en) 1989-11-08 1990-11-06 Phase-type focusing screen

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP29046589A JP2511833B2 (en) 1989-11-08 1989-11-08 Phase diffuser

Publications (2)

Publication Number Publication Date
JPH03150538A JPH03150538A (en) 1991-06-26
JP2511833B2 true JP2511833B2 (en) 1996-07-03

Family

ID=17756371

Family Applications (1)

Application Number Title Priority Date Filing Date
JP29046589A Expired - Fee Related JP2511833B2 (en) 1989-11-08 1989-11-08 Phase diffuser

Country Status (1)

Country Link
JP (1) JP2511833B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5629785A (en) * 1995-05-04 1997-05-13 Motorola, Inc. Polymer dispersed liquid crystal display device with asymmetric optical diffuser
JP5686645B2 (en) * 2011-03-24 2015-03-18 キヤノン株式会社 Focus plate and finder system having the same

Also Published As

Publication number Publication date
JPH03150538A (en) 1991-06-26

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