【０００１】
【発明の属する技術分野】
本発明は均一且つ強い照射を要する照明系に属する。
【０００２】
【従来の技術】
従来の光線の平行化としては射出された光線の一部のみを取り出す方式。フライアイレンズを用いて一旦結像させ、此の結像点を２次光源として平行光線化する方式等が在ったが何れも光源の全光束に対しての効率が悪いのと其の侭では中心部と周辺部の明るさの比が大きいのが欠点であった。
【０００３】
【発明が解決しようとする課題】
本発明は光源の全光束に対する利用効率を上げる事と明るさの比の改善を目的とした。放物面の開口を大とすれは効率は大となるが同時に周辺の光量比が著しく減少し且つ総体が大きくなりコスト増を招く結果となる。
【０００４】
【課題を解決するための手段】
光源から放射される光束の内平行光部分のみを取り出して用いる方式は光源から放射される光束の一部を用い、大部分を捨てると言う損失の大きい方式であり効率が悪い事は言うまでもない。同様にフライアイを用いる方式でも光源の全光束に比してに効率は必ずしも良くない。光源の全光束を用いる事は無理で在るとして、利用効率を高める手段の一は反射鏡を用いて光束の重畳を成立させる事であり次いでは光束の分散集合に於ける損失の減少を計る事が必要である。
【０００５】
図３は従来用いられてきたフライアイレンズアレイの断面を示す。実線は集光アレイに依って焦点位置で結像後発散する光線を示している。今、コリメ−タアレイを構成する一単位に就いて見ると双方の焦点間間隔が大で在ればコリメ−タアレイに到達する範囲に在る集光レンズ数が多くなり光量の均一化が増すが中心部では均一化されるが周辺の非重畳部も増して光束全体を使用出来ず、加えてコリメ−タアレイの焦点を通過せずに入射して斜光線となる光束も増加し、透過光量と均一化に問題が残る。破線はコリメ−タアレイの平行射出の条件を満たす範囲を示す。
【０００６】
【発明の実施の形態】
図１−１は本発明に於ける放物面鏡の断面を示す１−３は鏡体の反射面を示し１−４は焦点位置に置かれた光源を示す。此の放物鏡の効率は６０％を超える平行光を射出し従来の３５〜４５％を改善してる。
図１−２は照明を要する面積を満たすアレイとして置かれた放物面鏡群の断面を示す。
【０００７】
図２は放物面アレイ１−２からの平行光線を一旦焦点位置に結像させる集光レンズアレイ２−１と此の結像点を光源とし共軛点に再結像する時点で集光レンズアレイの単位レンズが同時に複数のリレ−レンズ２−２に入射し其れぞれが共軛点に結像するが此の時結像点は一点でなく複数の結像点となりリレ−アレイ全体としてはあたかも一点に対応したかの如き状態となりこれを光源とするコリメ−タアレイ２−３に依って平行光線として射出される。
【０００８】
リレ−レンズの焦点距離を幾何光学的に定めた例を示す。集光レンズに依って焦点に結像される光線の傾斜は正弦に於いて０．５・Ｂ／Ｆｃで在るから距離（２・Ｎ＋１）Ｆｃの位置では高さは０．５Ｂ・Ｎと成り集光レンズの最大傾斜光線がリレ−レンズアレイ外形を集光レンズアレイと同寸としたとき過不足無く全光束が入射され共軛点に集光される、入射から射出迄の光路長は各アレイの焦点距離を詰める事で短縮が可能で在る。
【０００９】
【実施例】
原点を頂点とする放物面鏡の断面の方程式をＹ＾２＝２・Ｒ・Ｘ と表示する時（ｂａｓｉｃ表示）開口径を２５．４ 頂点曲率半径 Ｒ＝４．５ とし、光源は管径を２．４の冷陰極管を用いて有効反射率６２％を得た。
此の開口径を５等分すれば光量比は中心２１．８％、中間帯１６．６％周縁で６．３％となり著しい光量差を持っている。此の光源アレイをレンズアレイ系を通過させる事で周縁部を除いてほぼ均等に分配され、且つ３０％に満たない透過損失で平行光束を得る事が出来た。
【００１０】
【発明の効果】
従来のフライアイアレイに於て集光後、発散した光束をリレ−アレイを中間に挿入する事でコリメ−タアレイの焦点を通過させ、平行光射出の効率を極限迄高め得た。従来に比し１８０％にも及ぶ効率となった。
【図面の簡単な説明】
【図１】放物面鏡と光源。放物面鏡アレイの例を示す。
【図２】リレ−レンズアレイを用いた照明系の概略を示す。
【図３】フライアイレンズに於ける光束の均一化と平行化を示す。[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to an illumination system that requires uniform and intense irradiation.
[0002]
[Prior art]
Conventional collimation of light rays is a method of extracting only a part of the emitted light rays. There has been a system in which a fly-eye lens is used to form an image once, and this image formation point is converted into a parallel light beam as a secondary light source. However, a large ratio of the brightness between the central part and the peripheral part was a drawback.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to increase the utilization efficiency of the light source with respect to the total luminous flux and to improve the brightness ratio. Increasing the opening of the paraboloid increases efficiency, but at the same time, the peripheral light quantity ratio is remarkably reduced and the overall size increases, resulting in an increase in cost.
[0004]
[Means for Solving the Problems]
It goes without saying that the method of extracting and using only the parallel light portion of the light beam emitted from the light source is a lossy method in which a part of the light beam emitted from the light source is used and most of the light beam is discarded, and the efficiency is poor. Similarly, the efficiency using the fly eye is not always good compared to the total luminous flux of the light source. Since it is impossible to use the total luminous flux of the light source, one way to increase the utilization efficiency is to establish superimposition of the luminous flux using a reflector, and then to reduce the loss in the dispersed set of luminous flux Things are necessary.
[0005]
FIG. 3 shows a cross section of a conventionally used fly-eye lens array. A solid line indicates a light beam that diverges after image formation at the focal position due to the condensing array. Now, looking at one unit constituting the collimator array, if the distance between both focal points is large, the number of condensing lenses in the range reaching the collimator array increases, and the amount of light becomes more uniform. Although uniform in the center, the surrounding non-overlapping part increases and the entire light beam cannot be used, and in addition, the light beam that enters the collimator array without passing through the focal point and becomes oblique rays increases, Problems remain in uniformity. A broken line indicates a range that satisfies the parallel injection condition of the collimator array.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1-1 shows a cross section of a parabolic mirror according to the present invention. 1-3 shows a reflecting surface of the mirror body, and 1-4 shows a light source placed at a focal position. The efficiency of this parabolic mirror improves the conventional 35-45% by emitting more than 60% parallel light.
FIG. 1-2 shows a cross section of a group of parabolic mirrors placed as an array that fills the area requiring illumination.
[0007]
FIG. 2 shows a condensing lens array 2-1 that once forms an image of parallel rays from the paraboloidal array 1-2 at a focal position and condensing at the time of re-imaging at a common point using this imaging point as a light source. The unit lens of the lens array is simultaneously incident on a plurality of relay lenses 2-2 and each forms an image at a common point. At this time, the image forming point is not a single point but a plurality of image forming points. As a whole, it is as if it corresponded to one point, and is emitted as parallel rays by the collimator array 2-3 using this as a light source.
[0008]
An example in which the focal length of the relay lens is determined geometrically will be shown. The inclination of the light beam formed at the focal point by the condenser lens is 0.5 · B / Fc in the sine, so the height is 0.5B · N at the distance (2 · N + 1) Fc. When the maximum tilting ray of the condensing lens makes the outer dimensions of the relay lens array the same size as the condensing lens array, the entire light beam is incident and condensed at the common point without any excess or deficiency. Shortening is possible by reducing the focal length of each array.
[0009]
【Example】
When the equation of the cross section of the parabolic mirror whose origin is the vertex is displayed as Y ^ 2 = 2 · R · X (basic display), the aperture diameter is 25.4 vertex radius of curvature R = 4.5, and the light source is a tube An effective reflectance of 62% was obtained using a cold cathode tube having a diameter of 2.4.
If this aperture diameter is divided into 5 equal parts, the light quantity ratio is 21.8% at the center and 6.3% at the periphery of the intermediate band 16.6%, and there is a remarkable light quantity difference. By passing this light source array through the lens array system, it was distributed almost evenly except the peripheral portion, and a parallel light beam could be obtained with a transmission loss of less than 30%.
[0010]
【The invention's effect】
After condensing in the conventional fly's eye array, the divergent light beam is inserted in the middle of the relay array so that it passes through the focal point of the collimator array, and the efficiency of parallel light emission can be increased to the limit. The efficiency was as high as 180% compared to the conventional one.
[Brief description of the drawings]
FIG. 1 Parabolic mirror and light source. An example of a parabolic mirror array is shown.
FIG. 2 shows an outline of an illumination system using a relay lens array.
FIG. 3 shows light beam homogenization and parallelization in a fly-eye lens.
