JPH03172802A - Formation of concave mirror for projector - Google Patents
Formation of concave mirror for projectorInfo
- Publication number
- JPH03172802A JPH03172802A JP31057889A JP31057889A JPH03172802A JP H03172802 A JPH03172802 A JP H03172802A JP 31057889 A JP31057889 A JP 31057889A JP 31057889 A JP31057889 A JP 31057889A JP H03172802 A JPH03172802 A JP H03172802A
- Authority
- JP
- Japan
- Prior art keywords
- concave mirror
- optical axis
- light source
- light
- correction function
- 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.)
- Pending
Links
- 230000015572 biosynthetic process Effects 0.000 title description 4
- 230000003287 optical effect Effects 0.000 claims abstract description 25
- 230000002093 peripheral effect Effects 0.000 claims abstract description 19
- 238000000034 method Methods 0.000 claims description 13
- 230000003595 spectral effect Effects 0.000 claims 1
- 238000001816 cooling Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000005315 distribution function Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
Landscapes
- Optical Elements Other Than Lenses (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はビデオプロジェクタやオーバーヘンドブロジェ
クタ等の各種投写装置において、投写光源からの光を反
射する凹面鏡の形成方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a concave mirror that reflects light from a projection light source in various projection devices such as video projectors and overhead projectors.
投写装置は原理的には第３図に示すような構成をしてい
る。同図において投写光源ｌの光は放物面を有する凹面
鏡２により反射され、均一な平行光線になって液晶シャ
ッタ、フィルム等からなる被投写像３に照射され、レン
ズ系４によって拡大された画像をスクリーン５上に結像
していた。なお、凹面鏡２として楕円面鏡が使用される
場合には、凹面鏡２と被投写像３との間に設けられたコ
ンデンサレンズによって平行光線にされる。In principle, the projection device has a configuration as shown in FIG. In the figure, light from a projection light source 1 is reflected by a concave mirror 2 having a parabolic surface, becomes a uniform parallel beam of light, and is irradiated onto a projected image 3 consisting of a liquid crystal shutter, film, etc., and the image is magnified by a lens system 4. was imaged on screen 5. Note that when an ellipsoidal mirror is used as the concave mirror 2, the condenser lens provided between the concave mirror 2 and the projected image 3 converts the light into parallel rays.
〔発明が解決しようとする課題］
しかしながらこのような投写装置では、レンズ系４の特
性として、第３図に示す画角αが大きくなれば第４図の
線図に示すように画面周辺の光量が低下し、画面の周辺
部が暗くなって均一な明るさが得られないという問題が
あった。[Problem to be Solved by the Invention] However, in such a projection device, as a characteristic of the lens system 4, as the angle of view α shown in FIG. 3 increases, the amount of light around the screen increases as shown in the diagram in FIG. There was a problem in that the brightness decreased and the peripheral areas of the screen became dark, making it impossible to obtain uniform brightness.
この問題に対し、従来は、投写光源の出力を上げて光量
を増加することによって周辺部が暗くならないようにカ
バーしていた。しかしこの方法は、中心部と周辺部との
光量の格差を解消するものではなく、根本的な解決には
ならなかった。また、投写光源部には冷却用ファンが設
けられているが、光源の出力が増加することにより、投
写光源部の冷却用ファンに加わる負荷も大きくなるとい
う問題もあった。Conventionally, this problem has been solved by increasing the output of the projection light source to increase the amount of light so that the peripheral area does not become dark. However, this method did not eliminate the disparity in the amount of light between the center and the periphery, and did not provide a fundamental solution. Further, although the projection light source section is provided with a cooling fan, there is a problem in that as the output of the light source increases, the load applied to the cooling fan of the projection light source section also increases.
〔発明の目的］
本発明は上記した問題の解決を図ったもので、光源の出
力を上げることなく画像の周辺部を明るくできる凹面鏡
を提供することを目的としている。[Object of the Invention] The present invention aims to solve the above-mentioned problems, and aims to provide a concave mirror that can brighten the peripheral part of an image without increasing the output of the light source.
上記の目的を達成するために本発明は、投写画像の周辺
光量を補正する補正関数を凹面鏡の半径方向に求め、こ
の補正関数の積分値を等分する光軸と平行な分割平行線
を引き、光源からの光を等分する等分光線を引き、各等
分光線とこれに対応する分割平行線との各交点を求め、
これらの各交点に投写光源からの光を光軸と平行に反射
する反射面を形成し、各反射面を接続して光軸間りに回
転させる構成を採用している。また、楕円面鏡の場合も
同様な方法で形成できるものである。In order to achieve the above object, the present invention calculates a correction function in the radial direction of a concave mirror to correct the amount of peripheral light of a projected image, and draws dividing parallel lines parallel to the optical axis to equally divide the integral value of this correction function. , draw equal rays that equally divide the light from the light source, find each intersection of each equally divided ray and the corresponding dividing parallel line,
A configuration is adopted in which a reflecting surface that reflects the light from the projection light source parallel to the optical axis is formed at each of these intersection points, and each reflecting surface is connected and rotated between the optical axes. Further, an ellipsoidal mirror can also be formed by a similar method.
上記の構成とすることによって、投写光源の出力を上げ
ることなく投写画像の周辺部を明るくすることができ、
冷却ファンの負荷も低減することができる。With the above configuration, the peripheral area of the projected image can be brightened without increasing the output of the projection light source.
The load on the cooling fan can also be reduced.
以下に本発明の実施例を図面によって説明する。 Embodiments of the present invention will be described below with reference to the drawings.
第１図において、凹面鏡２として放物面鏡が使用され、
投写光源１は放物面の焦点Ｆ上に置かれている。凹面鏡
２における有効口径周辺上の任意点Ｍと焦点Ｆとを結び
、この線分ＦＭと光軸ｙとの角度θをＮ等分する等分光
線ａ１〜ａｎを引く（最後のａ７は線分ＦＭと重なる。In FIG. 1, a parabolic mirror is used as the concave mirror 2,
The projection light source 1 is placed on the focal point F of the paraboloid. Connect an arbitrary point M on the periphery of the effective aperture of the concave mirror 2 to the focal point F, and draw equal rays a1 to an that divide the angle θ between this line segment FM and the optical axis y into N equal parts (the last a7 is the line segment Overlaps with FM.
）と、各等分光線間の角度は全てθ／Ｎであるから、こ
れらの等分光線ａ１〜ａｎは、投写光源１からの光量を
等分することになる。) and the angles between the respective equally divided rays are all θ/N, so these equally divided rays a1 to an equally divide the amount of light from the projection light source 1.
４は投写用のレンズ系を示し、従来例と同様に図示しな
い被投写像を拡大してスクリーン５上に結像させる。Reference numeral 4 denotes a lens system for projection, which magnifies a projected image (not shown) and forms it on the screen 5, as in the conventional example.
上記の点Ｍと光軸ｙとを含む平面内で、スクリーン５の
右側に点線βで示された曲線は、補正をしない場合の光
量の分布関数である。これは、従来例で説明した第４図
の線図と同様のもので、画像中央部が明るく、周辺部が
暗くなることを示す。The curve indicated by the dotted line β on the right side of the screen 5 within the plane including the above-mentioned point M and the optical axis y is the distribution function of the amount of light without correction. This is similar to the diagram in FIG. 4 described in connection with the conventional example, and shows that the central part of the image is bright and the peripheral part is dark.
また、この曲線βに対し、実線で光量の補正関数γが描
かれている。この補正関数Ｔは中心から半径方向の任意
の距離に対する光量補正を表した関数である。本発明の
実施例では、補正関数Ｔは、周辺光量の低下を略々相殺
できるようにしているが、必ずしも画面の周辺が中央部
と同じ明るさである必要はなく、多少の相違であれば、
人間の視覚には違和感を与えない。そのためこの補正関
数Ｔは、周辺光量の低下を人間の視覚に惑じない程度に
緩和できる程度のものであればよい。Furthermore, a light amount correction function γ is drawn as a solid line with respect to this curve β. This correction function T is a function representing light amount correction for an arbitrary distance in the radial direction from the center. In the embodiment of the present invention, the correction function T is designed to substantially offset the decrease in peripheral illumination, but it is not necessary that the peripheral part of the screen has the same brightness as the central part, and if there is a slight difference, ,
It does not cause any discomfort to human vision. Therefore, the correction function T may be of a value that can alleviate the decrease in the amount of peripheral light to an extent that does not disturb human vision.
レンズ系４の位置に描かれた曲線γは、上記の補正関数
を凹面鏡２の前に移動したものである。The curve γ drawn at the position of the lens system 4 is obtained by moving the above correction function to the front of the concave mirror 2.
レンズ系４または凹面鏡２の半径方向をＸ軸として、光
軸をｙ軸とすれば、補正関数ＴはＸの関数γ（Ｘ）で表
すことができる。そして補正関数ｙ＝γ（Ｘ）の積分値
Ｓは、凹面鏡の半径をＲａとして以下のように表すこと
ができる。If the radial direction of the lens system 4 or concave mirror 2 is the X axis and the optical axis is the y axis, the correction function T can be expressed as a function γ(X) of X. The integral value S of the correction function y=γ(X) can be expressed as follows, where the radius of the concave mirror is Ra.
Ｓ ＝ Ｓ ｒ （ｘ） ｄ ｘ
この積分値Ｓを補正関数γ（Ｘ）が形成する面積Ｓと定
義し、この面積ＳをＮ等分する光軸ｙに平行となる分割
平行線ｂ１〜ｂ、を引く。S = S r (x) d x This integral value S is defined as the area S formed by the correction function γ(X), and dividing parallel lines b1 to b parallel to the optical axis y divide this area S into N equal parts. ,pull.
この分割平行線の任意のす、とこれに対応する等分光線
ａ、との交点をＡｍとする。以下同様の手順でＡ１〜Ａ
ｎを求める（最後の点ＡｎはＭと一敗する。）。一方、
等分光線ａ１〜ａ、と凹面鏡２との交点８１〜Ｂｎを求
め、前記各交点Ａ１〜Ａｎに、それぞれが対応する点８
１〜Ｂｎの接線と平行な反射面を形成すれば、この反射
面は、光源ｌからの光を光軸に平行に反射することとな
る。そして各反射面を連続すると新たな階段状の反射面
が得られ、これを光軸７回りに回転すれば、本発明の凹
面鏡６が形成される。Let Am be the intersection point of any part of this dividing parallel line and the corresponding equidistant ray a. Following the same steps, A1 to A
Find n (the last point An is defeated by M). on the other hand,
Find the intersections 81-Bn of the equally divided rays a1-a and the concave mirror 2, and find the points 8 corresponding to each of the intersections A1-An.
If a reflecting surface is formed parallel to the tangent line of 1 to Bn, this reflecting surface will reflect the light from the light source 1 in parallel to the optical axis. Then, by connecting each reflecting surface, a new stepped reflecting surface is obtained, and by rotating this about the optical axis 7, the concave mirror 6 of the present invention is formed.
ここで、等分光線の任意のａ、について観察すると、光
軸ｙからａ、までの角度θ５の光束は、従来の放物面鏡
２では半径Ｒｂ、の範囲を照射していた。これに対し本
発明の凹面鏡６では半径Ｒａ１Ｉの範囲を照射すること
となる。そして図から明らかにＲａ、＞Ｒｂ、、である
。すなわち凹面鏡６の中心部は従来より広い面積を照射
することになり、中心部はそれだけ暗くなる。一方θ−
θ８の光束は、従来は周辺部のＲａ −Ｒｂ、の範囲を
照射していたが、本発明の凹面鏡では、これより狭いＲ
ａ−Ｒａｓの範囲だけを照射することになり、周辺部は
明るくなる。すなわち、本発明の凹面鏡は、適当に設定
された補正関数にしたがって、周辺光量を増加し、画面
の中心部と周辺部との明るさの差をなくすか、又は差を
小さくすることができる。Here, when observing an arbitrary a of the equidistant rays, the light beam at an angle θ5 from the optical axis y to a irradiates a range of radius Rb in the conventional parabolic mirror 2. In contrast, the concave mirror 6 of the present invention irradiates a range of radius Ra1I. It is clear from the figure that Ra,>Rb. In other words, the center of the concave mirror 6 illuminates a wider area than before, and the center becomes darker accordingly. On the other hand, θ−
Conventionally, the light flux of θ8 illuminated the range of Ra - Rb in the peripheral area, but with the concave mirror of the present invention, the range of R
Only the a-Ras range is irradiated, and the peripheral area becomes brighter. That is, the concave mirror of the present invention can increase the amount of peripheral light according to an appropriately set correction function, and can eliminate or reduce the difference in brightness between the center and peripheral parts of the screen.
第２図は凹面鏡２が楕円面鏡２の場合の実施例を示す。FIG. 2 shows an embodiment in which the concave mirror 2 is an ellipsoidal mirror 2. FIG.
投写光源１は楕円の一方の焦点Ｆに置かれ、楕円面鏡２
に反射して他方の焦点Ｆ′に集束し、コンデンサレンズ
７によって平行光線にされて、被投写像３を照射し、レ
ンズ系４によってスクリーン５上に拡大された画像を結
像する。曲線βは補正なしの場合の光量分布関数で、曲
線γは補正関数である。この補正関数γをコンデンサレ
ンズ７の位置に移動して描く。A projection light source 1 is placed at one focal point F of the ellipse, and an ellipsoidal mirror 2
The light is reflected by the light beam and converged at the other focal point F', and is converted into parallel light by the condenser lens 7 to illuminate the projected image 3, and an enlarged image is formed on the screen 5 by the lens system 4. The curve β is a light amount distribution function without correction, and the curve γ is a correction function. This correction function γ is moved to the position of the condenser lens 7 and drawn.
第１図の実施例と同様に補正関数ｒ （ｘ）を積分して
面積Ｓを求め、この面積をｎ等分する分割平行線ｂ１〜
ｂ、を引き、各線から凹面鏡２に向かって光線と逆向き
に引いた線をｃ１〜ｃ７とする。Similar to the embodiment shown in FIG. 1, the area S is obtained by integrating the correction function r (x), and dividing parallel lines b1 to 1 divide this area into n equal parts.
b, and the lines drawn from each line toward the concave mirror 2 in the opposite direction to the light beam are c1 to c7.
一方投写光源１からは、やはり第１図の場合と同様に等
分光線ａ１〜ａ７を引き、相対応するもの同士の交点Ａ
１〜Ａｎを求める。これらの交点Ａ１〜Ａｎに、等分光
線ａ１〜ａ７が入射光線となり、逆向きの線ｃ１〜ｃｎ
が反射光線となる反射面を設ける。そして、これらの各
反射面を接続すれば、ＯＭをつなぐ階段状に段差の付い
た反射面が形成され、これを光軸７回りに回転すれば、
本発明の凹面鏡６となる。On the other hand, from the projection light source 1, equally divided rays a1 to a7 are drawn as in the case of FIG. 1, and the intersection point A of the corresponding ones is
Find 1 to An. Equally divided rays a1 to a7 become incident rays at these intersection points A1 to An, and oppositely oriented lines c1 to cn
A reflective surface is provided where the light becomes a reflected ray. Then, by connecting these reflective surfaces, a stepped reflective surface connecting the OMs is formed, and if this is rotated around the optical axis 7,
This becomes the concave mirror 6 of the present invention.
以上説明したように本発明によれば、画面の周辺と中心
との明るさの差を無くすことができるか、または小さく
することができ、人間の視覚では中心部とほとんど同じ
明るさに感じる画像を投写することができる。また、投
写光源の出力も小さくすることができ、冷却負荷を小さ
くすることができる。As explained above, according to the present invention, it is possible to eliminate or reduce the difference in brightness between the periphery and the center of the screen, and to human vision, images appear to have almost the same brightness as the center. can be projected. Further, the output of the projection light source can also be reduced, and the cooling load can be reduced.
第１図は本発明における凹面鏡の形成方法の実施例で、
元の凹面鏡が放物面鏡の場合の形成方法を示す図、
第２図は同じく楕円面鏡の場合の形成方法を示す図、
第３図は投写装置の原理を示す図、
第４図は画角の増加によって従来の画面の周辺部が、中
心部より暗くなる状態を示す線図である。
１・・・投写光源、６・・・凹面鏡、７・・・コンデン
サレンズ、Ｍ・・・凹面鏡の口径周辺上の任意点、ｒ
（ｘ）・・・補正関数、ｙ・・・光軸、ａ１〜ａ７・・
・等分光線、ｂ１〜ｂ、、・・・分割平行線、０１〜ｃ
７・・・逆向きの線、Ａ１〜Ａｎ・・・等分光線と対応
する分割平行線との交点、・Ｓ・・・補正関数が形成す
る面積。FIG. 1 shows an example of the method for forming a concave mirror according to the present invention.
Figure 2 shows the formation method when the original concave mirror is a parabolic mirror, Figure 2 shows the formation method when the original concave mirror is an ellipsoidal mirror, Figure 3 shows the principle of the projection device, Figure 4 shows the formation method when the original concave mirror is a parabolic mirror. FIG. 2 is a diagram illustrating a state in which the peripheral part of a conventional screen becomes darker than the center part due to an increase in the angle of view. 1... Projection light source, 6... Concave mirror, 7... Condenser lens, M... Arbitrary point around the aperture of the concave mirror, r
(x)...Correction function, y...Optical axis, a1 to a7...
・Equivalent rays, b1~b,... Dividing parallel lines, 01~c
7... Line in the opposite direction, A1-An... Intersection of the equally divided ray and the corresponding dividing parallel line, S... Area formed by the correction function.
Claims (2)
おいて、凹面鏡の口径周辺上の任意点と光軸上の投写光
源とを結ぶ線が光軸となす角を複数等分に分割する等分
光線を引き、投写画面の周辺光量を補正する補正関数を
上記任意点を含む半径方向に描き、該補正関数が形成す
る面積を前記等分光線と同数の複数に等分して光軸と平
行になる分割平行線を引き、該分割平行線とこれに対応
する前記等分光線との各交点を求め、これらの各交点に
投写光源からの光を光軸と平行に反射する反射面を形成
し、各反射面を接続して光軸回りに回転させることを特
徴とする投写装置用凹面鏡の形成方法。(1) In a method of forming a concave mirror used as a light source for a projection device, an angle formed by a line connecting an arbitrary point around the aperture of the concave mirror and the projection light source on the optical axis with the optical axis is divided into multiple equal parts. Draw a spectral line, draw a correction function to correct the amount of peripheral light on the projection screen in the radial direction including the above arbitrary point, and divide the area formed by the correction function into the same number of equal rays as the optical axis. Draw dividing parallel lines that become parallel, find each intersection between the divided parallel lines and the corresponding equally divided rays, and place a reflecting surface that reflects the light from the projection light source parallel to the optical axis at each of these intersections. 1. A method for forming a concave mirror for a projection device, the method comprising forming a concave mirror for a projection device, connecting each reflecting surface, and rotating it around an optical axis.
サレンズを介して略々平行な光束として射出する投写装
置に使用される凹面鏡の形成方法において、凹面鏡の口
径周辺上の任意点と光軸上の投写光源とを結ぶ線が光軸
となす角を複数等分に分割する等分光線を引き、投写画
面の周辺光量を補正する補正関数をコンデンサレンズの
上記任意点に対応する半径方向に描き、該補正関数が形
成する面積を光軸と平行な線で前記等分光線と同数の複
数に等分割し、各分割線を通りコンデンサレンズから凹
面鏡に向けて光線と逆向きに引いた線と、該光線に対応
する前記等分光線との交点を求め、各交点に等分光線方
向からの入射光線を前記逆向きの線の方向に反射する反
射面を設け、各反射面を接続して光軸回りに回転して形
成することを特徴とする投写装置用凹面鏡の形成方法。(2) In a method of forming a concave mirror used in a projection device in which light from a projection light source is reflected by a concave mirror and then emitted as a substantially parallel beam through a condenser lens, the light is Draw an equal light line that divides the angle formed by the optical axis by the line connecting the projection light source on the axis into multiple equal parts, and apply a correction function to correct the amount of peripheral light on the projection screen in the radial direction corresponding to the above arbitrary point of the condenser lens. The area formed by the correction function was divided equally into the same number of equally divided rays by lines parallel to the optical axis, and the area was drawn in the opposite direction to the rays from the condenser lens to the concave mirror through each dividing line. Find the intersection of the line and the equidistant ray corresponding to the ray, provide a reflective surface at each intersection to reflect the incident ray from the equidistant ray direction in the direction of the opposite line, and connect each reflective surface. 1. A method for forming a concave mirror for a projection device, the method comprising: forming a concave mirror by rotating it around an optical axis.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31057889A JPH03172802A (en) | 1989-12-01 | 1989-12-01 | Formation of concave mirror for projector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31057889A JPH03172802A (en) | 1989-12-01 | 1989-12-01 | Formation of concave mirror for projector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03172802A true JPH03172802A (en) | 1991-07-26 |
Family
ID=18006924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31057889A Pending JPH03172802A (en) | 1989-12-01 | 1989-12-01 | Formation of concave mirror for projector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03172802A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5532884A (en) * | 1992-03-06 | 1996-07-02 | Quantum Corporation | Apparatus and method for fabricating a deflection mirror tower |
| US6705737B1 (en) * | 2002-08-20 | 2004-03-16 | Raytheon Co. | Reflective optical apparatus for interconverting between a point of light and a line of light |
-
1989
- 1989-12-01 JP JP31057889A patent/JPH03172802A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5532884A (en) * | 1992-03-06 | 1996-07-02 | Quantum Corporation | Apparatus and method for fabricating a deflection mirror tower |
| US5790327A (en) * | 1992-03-06 | 1998-08-04 | Quantum Corporation | Apparatus and method for fabricating a deflection mirror tower |
| US5793731A (en) * | 1992-03-06 | 1998-08-11 | Quantum Corporation | Apparatus and method for fabricating a deflection mirror tower |
| US5835290A (en) * | 1992-03-06 | 1998-11-10 | Quantum Corporation | Deflection mirror tower for an optical disk drive |
| US5838503A (en) * | 1992-03-06 | 1998-11-17 | Quantum Corporation | Deflection mirror tower |
| US5872663A (en) * | 1992-03-06 | 1999-02-16 | Quantum Corporation | Apparatus and method for fabricating a deflection mirror tower |
| US6705737B1 (en) * | 2002-08-20 | 2004-03-16 | Raytheon Co. | Reflective optical apparatus for interconverting between a point of light and a line of light |
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