JP2004118140A - Stereoscopic video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stereoscopic video display device which displays a stereoscopic color video inconspicuous in color moire in a color stereoscopic video display system without using special spectacles. <P>SOLUTION: An interval between moire stripes is narrowed by applying specified relation to the relative arrangement of pixel arrays on a color liquid crystal display 16 and a slit 12 or the like on a parallax barrier 15 being the component parts of the stereoscopic video display device 10a without adding a new device or part. <P>COPYRIGHT: (C)2004,JPO

Description

【００４４】
（３）式よりｆはさまざまな値をとるわけであるが、ここでｆが取り得る最大値はパララックスバリア１５を視点よりカラー液晶ディスプレイ１６上へ投影したサンプリング周波数の１／２である。これは一定間隔をもって配置されたスリット１２によりＲＧＢのサブピクセルを観測することが一種の標本化といえるためである。
【００４５】
これにより、カラー液晶ディスプレイ１６と観測者４との距離ｄ、パララックスバリア１５との間隔ｇ、画素間隔ｐとしたとき、ｆの上限値、そのときの観察位置から見込んだ表示部上の間隔ｓ_１´、ならびにパターン（スリット）間隔ｓ_１の関係は次式により定まる。
【００４６】
【数２】

【００４７】
ここで、立体映像表示装置１０ａにおけるほとんどのケースでｇ≪ｄの関係があることを考慮すると、パターン間隔ｓ_１が画素間隔ｐの整数倍にｐ／２を加えた値を有すること、すなち（１）式の関係をみたすことで、発生する色モアレの周期はパターン間隔ｓ_１の２倍となり色モアレは充分目立たなくなることが言える。そして、カラー液晶ディスプレイ１６（表示部）とパララックスバリア１５（スクリーン）との間隔ｇが無視できない場合は、観測者４の視点から表示部までの距離と、スクリーンまでの距離との比率に基づいた補正項（１−ｇ／ｄ）を有する（６）式の関係を間隔ｓ_１（補正パターン間隔）が満たすことで同上の効果が得られることとなる。なお、以上の検討はパターンがスリットである前提で行ったが、他に円筒レンズ、ピンホール、またはレンズであっても同様である。
【００４８】
次に、図４（ａ）を参照して、色モアレの視認性について具体的に検証する。図４（ａ）は、画素間隔ｐとパターン（ピンホール）間隔ｓ_１が（１）式の関係を満たしｎ＝２の場合、発生する色モアレを説明する図である。なお、図４（ａ）は、図３で示したカラー液晶ディスプレイ１６にスクリーンとしてピンホール板を、同色のサブピクセルの配列方向と、ピンホールの縦配列方向とが一致するように設置したものとする。そして図中、各種マーク（４１Ｒ、４１Ｇ、４１Ｂ）は、観測者がピンホールを介してのカラー液晶ディスプレイ１６表面を観測したとき、観測者の視線が捕らえたカラー液晶ディスプレイ１６上の中心点を示したものである。
【００４９】
ここで、マーク４１Ｇに着目すると、縦方向に形成されている同色のマーク４１Ｇの列は一定の間隔２ｓ_１で水平方向に繰り返し形成されていることがわかる。すなわち、（１）式を満たすことで、発生する色モアレの周期は取り得る値として最小の、パターン間隔ｓ_１の２倍となる。これはモアレ縞の間隔として充分狭いものであり、これにより色モアレは認識しにくいものとなり高画質の立体映像が表示されることとなる。
【００５０】
以上、第一の実施の形態において立体映像表示装置を構成する表示部としてカラー液晶ディスプレイを例示して説明したが、これに代わりＰＤＰのようなカラーフィルタを備えた他のディスプレイ、三原色ＬＥＤを配列したカラーＬＥＤパネル、カラーフィルタを備えた液晶パネルによるプロジェクタ等であってもよい。
【００５１】
（第二の実施の形態）
次に図１及び図５（ａ）を参照して本発明における第二の実施の形態について説明する。なお、本実施の形態における立体映像装置１０ａ（図１）の基本構成は、第一の実施の形態におけるものと同じであるので説明は省略する。第二の実施の形態において第一の実施の形態との装置構成上の相違点は、画素間隔ｐとパターン（スリット）間隔ｓ_２が（１）式に代わり次式の関係を有する点である。
【００５２】
ｓ_２＝（ｎ＋ｋ／３）ｐ　（ｋ＝１，２、ｎ：整数）　　　（７）
【００５３】
（７）式で示す関係を有することによりパターン間隔ｓ_２は画素間隔ｐの整数倍にサブピクセル間隔ｑ（図３）または２ｑを加えた値となる。これにより第一の実施の形態では、スリット間隔の二倍であった色モアレの周期が、本実施形態ではスリット間隔の三倍となり、ＲＧＢの三種のサブピクセルが色ごと順番にスリット１２を通して観測者に視認されることになる。
【００５４】
以下、画素間隔ｐとパターン間隔ｓ_２が（７）式をみたすことにより、前記の作用が得られることを数式にて検証する。ここで、ＲＧＢの三色のサブピクセルが色毎順番に観測される為には観測者４からの視線延長線上、隣接するスリット１２を経由してカラー液晶ディスプレイ１６上に結ぶ交点の空間周波数１／ｓ_２´がその値の１／３もしくはその整数倍になればよい。よって（３）式は次式のように置き換えられる。
【００５５】
【数３】

【００５６】
この（８）式は、ｇ≪ｄの関係があることを考慮すると、さらに展開され式（７）が得られることとなる。
【００５７】
次に、図５（ａ）を参照して色モアレの視認性について具体的に検証する。図５（ａ）は、画素間隔ｐとパターン間隔ｓ_２が（７）式の関係を満たす場合、観測者の視点がとらえたカラー液晶ディスプレイ上の中心点をマーク（５１Ｒ、５１Ｇ、５１Ｂ）で示し、発生する色モアレを説明する図である。図５（ａ）は（５）式がｎ＝２、ｋ＝１の場合を示しており、パターン間隔がｓ_１からｓ_２に変更された点を除き、図４（ａ）と同様である。図５（ａ）より明らかなように同色マークの繰り返し間隔（周期）はパターン間隔ｓ_２の三倍となり、ＲＧＢのサブピクセルが色毎に順番に観測されるのがわかる。
【００５８】
本実施の形態における効果を以下述べる。先に示した第一の実施の形態（図４（ａ））の場合は、たとえば一色のサブピクセル４１Ｇに着目した場合、緑（Ｇ）色列の明暗の繰り返し間隔が取り得る値として最小の２ｓ_１となるものを例示したものである。この場合、観察位置が固定されていればＧの発色によるモアレ縞の周期は最小となり色モアレは認識されにくく高画質の立体映像が得られる一方、観測位置を水平方向に移動させるとモアレ縞を構成する色が変化する現象が生じる場合がある。
【００５９】
そこで、モアレ縞の周期を若干大きくして、前記現象を回避する条件を示したのが（７）式で表すところの、画素間隔ｐとパターン間隔ｓ_２の関係である。すなわちパターン間隔ｓ_２が画素間隔ｐの（ｎ＋１／３）倍または（ｎ＋２／３）倍の関係を有することで色モアレの周期がパターン間隔ｓ_２の三倍となる。そしてＲＧＢのサブピクセルが色毎順番にスリットから観測され、観測位置を変えた場合にモアレ縞の構成色の見え方が変化する現象がなく、さらに色モアレが目立たず高品質の立体映像が表示されることとなる。
【００６０】
以上、第二の実施の形態における、画素がＲＧＢの三つのサブピクセルで構成されている場合について説明したが、これを一般化し、一つの画素がｍ個のサブピクセルで構成されている場合について以下説明する。この場合、（３）式は次のように展開される。
【００６１】
【数４】

【００６２】
ここで、立体映像表示装置１０ａにおけるほとんどのケースでｇ≪ｄの関係があることを考慮すると、パターン間隔ｓは画素間隔ｐの整数倍にサブピクセル間隔ｑの整数倍を加えた値をとる。すなち（１２）式の関係をみたすことで、表示部上の一つの画素がｍ個のサブピクセルで構成されている場合、色モアレの周期がパターン間隔ｓのｍ倍となる。そしてｍ個のサブピクセルが色毎に順番にスリットから観測され、観測位置を変えた場合にモアレ縞の構成色の見え方が変化する現象がなくさらに色モアレが目立たず、高品質の立体映像が表示されることとなる。そして、カラー液晶ディスプレイ１６（表示部）とパララックスバリア１５（スクリーン）との間隔ｇが無視できない場合は、観測者４の視点から表示部までの距離と、スクリーンまでの距離との比率に基づいた補正項（１−ｇ／ｄ）を有する（１１）式の関係をとして間隔ｓ（補正パターン間隔）が満たすことで同上の効果が得られることとなる。
【００６３】
以上、第二の実施の形態において立体映像表示装置を構成するスクリーンとしてパララックスバリアを例示して説明したが、これに代わりレンチキュラーシート、レンズ板または、ピンホール板であってもよい。また、表示部としてカラー液晶ディスプレイを例示して説明したが、これに代わりＰＤＰのようなカラーフィルタを備えた他のディスプレイ、三原色ＬＥＤを配列したカラーＬＥＤパネル、カラーフィルタを備えた液晶パネルによるプロジェクタ等であってもよい。
【００６４】
（第三の実施の形態）
次に図４（ｂ）及び図５（ｂ）を参照して本発明における第三の実施の形態について説明する。なお、本実施の形態における立体映像装置の基本構成は、第一の実施の形態における図１と同じであるので説明は省略する。また図４（ｂ）及び図５（ｂ）は、本実施の形態における立体映像表示装置の表示面を示すものであり、パターン（ピンホール）配列が一定の傾きを有している点を除いて、図４（ａ）及び図５（ａ）と同じである。
【００６５】
図４（ｂ）及び図５（ｂ）では、特に同色マークの配置が斜め４５°となるようにパターンの傾きθを設定したもので、観察者の視点が捕らえたカラーディスプレイ上の中心点をマーク（４２Ｒ、４２Ｇ、４２Ｂ、５２Ｒ、５２Ｇ、５２Ｂ）で示したものである。図４（ｂ）は第一の実施の形態にて周期が２ｓ_１である色モアレを呈する場合であって、同色サブピクセル配列方向と、ピンホール縦配列方向との間においてθ＝ｔａｎ^−１（ｐ／２ｓ_１）なる傾きを有している。同様に図５（ｂ）は、第二の実施の形態における、ＲＧＢ三色のサブピクセルが一画素を形成している場合（ｍ＝３）であって、同色サブピクセル配列方向と、ピンホール縦配列方向との間においてθ＝ｔａｎ^−１（ｐ／３ｓ_２）なる傾きを有している。これらをまとめると以下のようになる。
【００６６】
モアレ縞の傾きを４５°にする条件
・第一の実施の形態の場合
θ＝ｔａｎ^−１（ｐ／２ｓ_１）　　　（１３）
・第二の実施の形態の場合
θ＝ｔａｎ^−１（ｋｐ／ｍｓ_２）　　（ｎ，ｋ：整数）　　　（１４）
（ｍ：一画素を形成するサブピクセルの数）
【００６７】
このように、表示部の同色サブピクセル配列方向とパターンの縦の配列方向との間に一定の傾斜を与えることで、モアレ縞の傾きを変える作用を有する。そして一例として傾きが４５°となる場合を（１３）、（１４）式として示したが、この時のθ値近傍前後で値を変化させるとモアレ縞の傾きも４５°を中心に前後する。さらに、本実施の形態では、ピンホールの縦横の配列が直交していないパターン配置を示しているが、実際上ｐ／ｓの値が充分小さいことを考慮すれば、図４（ａ）または図５（ａ）に示した正方格子状パターンを有するスクリーンをわずかに傾けることで十分に同様の作用が得られる。
【００６８】
このように、モアレ縞が傾斜する作用により、モアレ周期が同じであっても縦縞の場合に比べて色モアレを認識しにくい効果が得られる。すなわち、第一の実施の形態の場合においては、水平周波数がｆ＝０．５（１／ｓ_１´）の縦状パターンのモアレは避けられないわけであるが、このパターンが斜めになればさらにモアレは認識しにくくなる。
【００６９】
以上、第三の実施の形態においてピンホール板を用いた場合を一例として説明してきたが、これに代わりピンホールをレンズに置き代えたレンズ板であってもよい。また、ピンホールが縦方向に連続して配置していると考えれば、スリット列においても同様の効果が発揮されることは容易に想起でき、よって、スクリーンとしてレンチキュラーシートもしくはパララックスバリアを用いてもよい。そして、表示部としてカラー液晶ディスプレイを例示して説明したが、これに代わりＰＤＰのようなカラーフィルタを備えた他のディスプレイ、三原色ＬＥＤを配列したカラーＬＥＤパネル、カラーフィルタを備えた液晶パネルによるプロジェクタ等であってもよい。
【００７０】
【発明の効果】
以上説明したとおり、本発明に係る立体撮像装置及び立体表示装置により以下に示す優れた効果を奏する。
請求項１の発明による立体映像表示装置においては、従来装置に新たな構成を付加することなしに、発生するモアレ縞の間隔を狭めることで、色モアレを目立ちにくくし、高画質の立体映像を表示することができる。
請求項２ならびに請求項３の発明による立体映像表示装置においては、請求項１における効果に加えて観測位置を移動してもモアレ縞の構成色が変化しない高画質の立体映像を表示することができる。
【００７１】
請求項４の発明による立体映像表示装置においては、装置構成上、表示部とスクリーンとの間隔が広く設計された場合であっても、発生するモアレ縞の間隔を狭め、色モアレを目立ちにくくし、高画質の立体映像を表示することができる。請求項５の発明によれば、レンチキュラーシートまたはパララックスバリアをスクリーンとして用いた立体映像表示装置において高画質の立体映像が得られる。
請求項６の発明によれば、レンズ板またはピンホール板をスクリーンとして用いた立体映像表示装置において高画質の立体映像が得られる。
請求項７の発明による立体映像表示装置においては、従来装置に対して新たな構成を付加することなしに、発生するモアレ縞を傾斜させることで視覚的に色モアレを認識しにくくする効果を与え、高画質の立体映像を表示することができる。
【００７２】
【図面の簡単な説明】
【図１】本発明において、スクリーンの一例として示す、パララックスバリアを用いた場合の立体映像表示装置の構成を示す構成図である。
【図２】本発明において、スクリーンの一例として示す、ピンホール板を用いた場合の立体映像表示装置の構成を示す構成図である。
【図３】本発明において、表示部の一例として示す、カラー液晶ディスプレイ表面の画素構造を部分拡大して示した図である。
【図４】（ａ）第一の実施の形態において、色モアレの視認性を具体的に検証する為の図である。
（ｂ）第三の実施の形態において、ｓ＝（ｎ＋０．５）ｐ、（ｎ＝２）である場合の、色モアレの視認性を具体的に検証する為の図である。
【図５】（ａ）第二の実施の形態において、色モアレの視認性を具体的に検証する為の図である。
（ｂ）第三の実施の形態において、ｓ＝（ｎ＋１／３）ｐ、（ｎ＝２）である場合の、色モアレの視認性を具体的に検証する為の図である。
【図６】従来の立体映像表示装置においてスクリーンとしてパララックスバリアを用いた場合の構成図である。
【図７】従来の立体映像表示装置においてスクリーンとしてレンチキュラーシートを用いた場合の構成図である。
【符号の説明】
４　観測者
１０ａ，１０ｂ，１０ｃ，１０ｄ　立体映像表示装置
１２_１，１２_２，・・・１２_ｎ　スリット
１５　パララックスバリア
１６　カラー液晶ディスプレイ
２２　ピンホール
２５　ピンホール板
３１　画素
６２_１，６２_２，・・・６２_ｎ　スリット
６５　パララックスバリア
６６　表示部
７２_１，７２_２，・・・７２_ｎ　円筒レンズ
７５　レンチキュラーシート[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stereoscopic video display device using a parallax video system without using glasses.
[0002]
[Prior art]
In general, among parallax video systems that do not use glasses, many systems other than the projection system (using a projection device) and the holographic system have a lenticular sheet and a parallax barrier on a display unit having a flat surface such as a color liquid crystal display. , A pinhole plate or a lens plate (hereinafter, collectively referred to as a screen) in combination with a parallax image system. Each of the screens has a cylindrical lens, a slit array, a pinhole or a lens (hereinafter, these are collectively referred to as a pattern).
[0003]
Each of these parallax video systems reproduces a stereoscopic video based on binocular parallax and can be configured from a binocular system to a multi-view system with three or more eyes. According to this binocular method, two types of parallax images can be entered into the left and right eyes and a three-dimensional shape can be perceived.According to the multiview method, when the observation position changes, the image entering the left and right eyes changes, It is possible to perceive an image close to a realistic three-dimensional space.
[0004]
The configuration of a conventional parallax video stereoscopic video display device and the principle of stereoscopic display will be described with reference to FIG. FIG. 6 is a configuration diagram showing a basic configuration of a conventional stereoscopic video display device 10c using a parallax barrier as a screen. FIG. 6 is a top view of the stereoscopic image display device 10c and the observer 4 observing the stereoscopic image. The display unit 66 and the parallax barrier 65 are both perpendicular to the plane of the paper and both are constant. It is assumed that they are arranged in parallel at intervals. It is assumed that the entire display section 66 is composed of a large number of R (red), G (green), and B (blue) sub-pixels arranged regularly and vertically and horizontally on the surface. On the surface of the parallax barrier 65, slits 62 are formed at regular intervals as a pattern, with the longitudinal direction being the direction perpendicular to the paper surface.
[0005]
Here, the parallax barrier 65 (screen) divides the image on the display unit 66 so that different images (parallax images) enter the left and right eyes of the observer 4. This division is performed by the slit 62 (pattern) on the parallax barrier 65 having a function of limiting the traveling direction of the light emitted from the sub-pixel, so that a specific pixel on the display unit 66 is located on one of the right and left sides of the observer 4. This is realized by selective recognition by the eyes.
[0006]
FIG. 6 shows a case where the number of parallax images is three, that is, a trinocular type, and three viewpoints a, b, and c are formed at the observation position. Here, on the display unit 66, three images (A, B, and C) having different photographing angles are displayed in a vertically long strip-shaped pixel (A ₁ A ₂ ... A _n , B ₁ B ₂ ... B _n , C ₁ C ₂ ... C _n ), And these strips are repeated in a certain order and displayed on the display unit 66. The slit 62 is arranged such that the strip-shaped pixels are guided to viewpoints a, b, and c, which are fixed image viewing areas as A, B, and C original images. That is, the slit 62 is positioned so that only the image A on the display unit 66 can be seen from the viewpoint a, only the image B on the display unit 66 can be seen from the viewpoint b, and only the image C on the display unit 66 can be seen from the viewpoint c. It is assumed that
[0007]
Here, when the observer 4 is positioned so as to capture the viewpoint c with the right eye and the viewpoint b with the left eye, the images C and B enter the left and right eyes of the observer 4 as parallax images and are recognized as a three-dimensional shape. The Rukoto. Next, from this state, when the observer 4 moves his body to the left, the image entering both eyes changes to viewpoint a for the left eye and viewpoint b for the right eye. This makes it possible to observe wraparound stereoscopic images by moving the body to the left and right, and further expands the number of parallax images to a multi-view system, enabling smoother observation of wraparound stereoscopic images. It becomes possible.
[0008]
FIG. 7 shows an example in which a lenticular sheet 75 on which a plurality of cylindrical lenses 72 are arranged is used as a screen constituting a stereoscopic image display device. The cylindrical lens 72 has the same function as the slit 62 (FIG. 6) in that the observation range of a specific pixel on the display unit 66 is limited to a certain viewpoint by the light condensing action of the lens. Therefore, the three-dimensional image display device 10d constituted by the lenticular sheet 75 can be said to be equivalent to the one using the parallax barrier of FIG. 6 described above in terms of the principle of stereoscopic vision, but is excellent in that the light amount does not decrease.
[0009]
Although a detailed description is omitted, a so-called IP system (Integral Photography) using either a pinhole or a lens arranged two-dimensionally in a vertical and horizontal manner as a pattern on a screen constituting the stereoscopic video apparatus is used. is there. The feature of this method is that the parallax barrier method described with reference to FIG. 6 and the lenticular sheet method described with reference to FIG. 7 make it possible to observe a wraparound image from the left and right directions. The point is that images can be observed.
[0010]
The above-mentioned stereoscopic video display device has been expanding its application field, but there are various problems from the viewpoint of image quality evaluation, and generation of color moiré is one of them. Color moiré is a phenomenon in which color display is displayed with regular stripes of light and shade due to interference between the arrangement of RGB on the display unit and the arrangement of patterns on the screen. is there.
[0011]
Here, each pixel constituting the display section 66 of the stereoscopic video display device (10c, 10d) has a sub-pixel structure arranged regularly, and is formed on a parallax barrier 65, a lenticular sheet 75, a pinhole plate or a lens plate. Are visually recognized through the regularly arranged patterns. For this reason, a pixel on the display unit 66 originally reproduces a desired color only after the RGB sub-pixels are collectively observed. However, one pixel is formed based on the positional relationship between the observer 4 and the pixel on the display unit 66. In some cases, one of the RGB sub-pixels is preferentially displayed. The sub-pixel of which color is preferentially displayed is determined by the positional relationship between the observer 4, the sub-pixel, and the pattern. Color moiré changing in shape is observed, which contributes to lower image quality.
[0012]
Conventionally, to solve this problem, a method has been adopted in which a cylindrical lens on a lenticular sheet is made finer not in pixel units but in subpixel units so that the three colors of RGB can be viewed from the same viewpoint. According to this, all the light emitted from the cylindrical lens is one of RGB single colors, thereby suppressing color moiré. (For example, see Non-Patent Document 1)
[0013]
In addition, there is a device that uses a unit that optically diffuses colors to mix RGB on a display unit. According to this, by arranging the light diffusion plate between the display unit and the screen, emitted light from adjacent sub-pixels in the same pixel is mixed before reaching the pattern on the screen. After the color mixing, the light traveling direction is determined by the action of the pattern, so that color moiré does not occur. (For example, see Non-Patent Document 2)
[0014]
[Non-patent document 1]
R. Borner, Displays 20 (1999), p57-64, FIG. 4
[Non-patent document 2]
Kobayashi, Washai, Okui, Okano, "Examination of Color Moire Reduction in Integral Photography Using Diffusion Plate", 2001 IEICE Winter Conference, P103, Performance No. 7-6
[0015]
[Problems to be solved by the invention]
However, each of the above-described moiré avoidance methods has some problems in practical use. The former method of increasing the definition of the lenticular sheet not in pixel units but in sub-pixel units requires the width of the cylindrical lens to be smaller than the pixel size of the liquid crystal, and requires a high level of processing accuracy. It can be said that it is extremely difficult to manufacture a mold used for manufacturing such a lens array. The latter method of mixing RGB on the display unit and interposing a light scattering plate or the like for optically scattering colors between the liquid crystal display unit and the screen is superior to the former method in that the fabrication is easy. A problem of lowering the resolution. As described above, the moiré avoidance method according to the conventional method cannot be said to be sufficient as a countermeasure due to manufacturing problems and other secondary problems.
[0016]
The present invention is intended to solve the problem of such a conventional moiré avoidance method, and can reduce the resolution without adding a new device or part to a conventional stereoscopic video display device. It is an object of the present invention to provide a stereoscopic video display device that can reduce color moiré when displaying a color stereoscopic image without inviting.
[0017]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object. First, the stereoscopic video display device according to claim 1 is configured such that a pixel composed of three sub-pixels each emitting three primary colors is a fixed pixel. A display unit that displays an image, and a plurality of patterns that limit the traveling direction of light emitted from sub-pixels of the display unit are arranged in a plane at regular intervals to divide the image into parallax images. In the three-dimensional image display device provided with a screen, the pattern is arranged so as to have a pattern interval obtained by adding half of the pixel interval to an integral multiple of the pixel interval.
[0018]
According to this configuration, in a case where the display unit configuring the stereoscopic video display device has a general RGB sub-pixel structure or the like, the cycle of the generated color moiré is twice the minimum possible pattern value, that is, the pattern interval. . As a result, the interval between the moiré fringes generated on the stereoscopic video display device becomes sufficiently small, and it becomes difficult to recognize color moiré.
[0019]
A stereoscopic image display device according to claim 2, wherein a display unit that displays an image by arranging pixels formed by arranging a plurality of sub-pixels at a fixed sub-pixel interval and arranging the pixels on a plane at a fixed pixel interval. A screen that divides the image into parallax images by arranging a plurality of patterns that limit the traveling direction of light emitted from the sub-pixels of the display unit at regular intervals, and The patterns are arranged so as to have a pattern interval obtained by adding an integer multiple of the sub-pixel interval to an integer multiple of the pixel interval.
[0020]
According to this configuration, when the pixels forming the surface of the display unit are composed of m subpixels, the period of the generated color moiré is m times the pattern interval, and the m subpixels are sequentially arranged for each color. Will be observed from the pattern. As a result, the interval between moire fringes generated on the three-dimensional image display device becomes sufficiently small, and color moiré becomes difficult to be recognized.
[0021]
In the three-dimensional image display device according to the third aspect, in the three-dimensional image display device according to the second aspect, the number of sub-pixels forming the pixel is three, and each of the sub-pixels has three primary colors. Each of them emits light.
[0022]
According to this configuration, when the display unit configuring the stereoscopic video display device has a general RGB sub-pixel structure, the cycle of the generated color moiré is three times the pattern interval, and three sub-pixels are further colored. Observed from the pattern in order every time. As a result, the interval between moire fringes generated on the three-dimensional image display device becomes sufficiently small, and color moiré becomes difficult to be recognized.
[0023]
The stereoscopic video display device according to claim 4, wherein the stereoscopic video display device according to any one of claims 1 to 3, wherein a distance from a specific viewpoint to the display unit and the screen from the viewpoint. The pattern is arranged at a corrected pattern interval obtained by correcting the pattern interval based on a ratio to the distance to the pattern.
[0024]
According to such a configuration, even when the space between the display unit and the screen is designed to be wide in the stereoscopic video display device, the interval between moiré stripes generated on the stereoscopic video display device is sufficiently small, and color moiré is reduced. It becomes difficult to be recognized.
[0025]
A three-dimensional image display device according to claim 5, wherein the screen is a lenticular sheet or a slit row formed of a cylindrical lens as the pattern, in the three-dimensional image display device according to any one of claims 1 to 4. And a parallax barrier.
[0026]
According to such a configuration, in a three-dimensional image display device using a lenticular sheet or a parallax barrier as a screen, the interval between moiré stripes generated on the three-dimensional image display device becomes sufficiently small, and color moiré becomes difficult to be recognized.
[0027]
The stereoscopic image display device according to claim 6 is the stereoscopic image display device according to any one of claims 1 to 4, wherein the screen includes a lens plate formed of a lens as the pattern or a pinhole. One of the pinhole plates.
[0028]
According to this configuration, in a three-dimensional image display device using a lens plate or a pinhole plate as a screen, the interval between moiré fringes generated on the three-dimensional image display device becomes sufficiently small, and color moiré becomes difficult to be recognized.
[0029]
The stereoscopic image display device according to claim 7 is the stereoscopic image display device according to any one of claims 1 to 6, wherein the display unit is configured such that sub-pixels of the same color continue in the vertical direction. In the vertical stripe structure in which pixels are arranged, the vertical arrangement direction in which the same color sub-pixels are continuous and the vertical arrangement direction of the pattern have a certain angle.
[0030]
According to such a configuration, the vertical stripe formed by the continuous sub-pixels of the same color and the angle formed by the slit or the cylindrical lens or the angle formed by the vertical arrangement of the lens or the pinhole have a constant value. As a result, moiré fringes formed on the stereoscopic video display device are inclined, and color moiré is less likely to be recognized.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram showing a configuration of a stereoscopic image display device 10a when a parallax barrier is used as a screen. The stereoscopic image display device 10a includes a color liquid crystal display 16 as a display unit and a parallax barrier 15 as a screen, both of which are viewed from above. The color liquid crystal display 16 and the parallax barrier 15 are located in parallel at a distance g, and are particularly fixed by a frame (not shown).
[0032]
On the parallax barrier 15, slits 12 having a constant aperture ratio are cut in a pattern with an optical gap having a longitudinal direction perpendicular to the paper surface, and are arranged in parallel at equal intervals s. It is assumed that the observer 4 observes the surface of the color liquid crystal display 16 through the slit 12 of the parallax barrier 15 at a distance d sufficiently longer than the distance g between the color liquid crystal display 16 and the parallax barrier 15.
[0033]
FIG. 2 is a configuration diagram showing a configuration of the stereoscopic video display device 10b when a pinhole plate is used as a screen. This figure is a perspective view showing another application example in the first embodiment in which a pinhole plate 25 is used instead of the parallax barrier 15 (FIG. 1) as a screen constituting the stereoscopic image display device 10b. FIG. Here, it is assumed that pinholes 22 having a constant diameter are optically penetrated in the pinhole plate 25 and are equally spaced vertically and horizontally as patterns, and are regularly arranged two-dimensionally at intervals s. The positional relationship and configuration of the pinhole plate 25, the color liquid crystal display 16, and the observer 4 in FIG. 2 are the same as the relationship between the parallax barrier 15, the color liquid crystal display 16, and the observer 4 in FIG. 1, respectively. Detailed description is omitted.
[0034]
FIG. 3 is a partially enlarged view of a pixel structure on a surface of a color liquid crystal display 16 (FIGS. 1 and 2) shown as an example of a display unit. In the drawing, R, G, and B are sub-pixels having red, green, and blue color filters mounted on the surface, respectively, and these three-color sub-pixels form a pixel 31 that is a basic unit of image display. Here, it is assumed that the arrangement interval of the sub-pixels is a sub-pixel interval q, and the arrangement interval of the sub-pixels of the same color, that is, the pixel arrangement interval is a pixel interval p. Pixels 31 composed of R (red), G (green), and B (blue) sub-pixels are arranged regularly in the vertical and horizontal directions so as to form a vertical stripe structure in which the same color continues in the vertical direction. It is configured.
[0035]
Here, it is assumed that images taken from a plurality of different angles are regularly aligned and displayed on the surface of the color liquid crystal display 16 (FIGS. 1 and 2). The direction of travel of the emitted light of the sub-pixels constituting these images is limited by the action of the pattern (slit 12 (FIG. 1) or pinhole 22 (FIG. 2)). Form a viewpoint. Here, FIG. 1 shows a state in which different images from three directions form different viewpoints a, b, and c, respectively.
[0036]
As described above, the function of the pattern (slit 12 (FIG. 1) or pinhole 22 (FIG. 2)) limits the traveling direction of the light emitted from the subpixel, and the screen (parallax barrier 15 (FIG. 1) or pinhole). The plate 25 (FIG. 2) as a whole has a role of dividing an image displayed on the color liquid crystal display 16 into parallax images for the right eye and the left eye.
[0037]
Further, in the stereoscopic image display devices 10a and 10b of the present embodiment, the pixel spacing p of the pixels forming the color liquid crystal display 16 and the pattern (slit 12 (FIG. 1) or pinhole 22 (FIG. The pattern interval s) has the following relationship. (Hereinafter, the value of s in the present embodiment is s ₁ And )
[0038]
s ₁ = (N + 0.5) p (n: integer) (1)
[0039]
By having the relationship shown in equation (1), the pattern interval s ₁ Is a value obtained by adding p / 2 to an integral multiple of the pixel interval p. ₁ 2 times As a result, color moiré in a stereoscopic image becomes less conspicuous, and a reduction in image quality is suppressed, thereby achieving the object of the present invention. This will be verified below.
[0040]
First, referring to FIG. 1, the visibility of moiré will be discussed below using mathematical expressions. First, assuming that the frequency of the moire fringes generated in the stereoscopic video is f and the period (interval) is r, the following equation is obtained.
[0041]
f = 1 / r (2)
[0042]
By the way, in formula (2), as the frequency f is larger, that is, as the cycle r is smaller, color moiré, which is a repetition of light and dark and color change of the stereoscopic image viewed from the observer 4, is less likely to be recognized. Here, the interval on the display unit viewed from the observation position, that is, the interval between intersections where the extension of the line of sight from the observer 4 connects to the color liquid crystal display 16 via the adjacent slit 12 of the parallax barrier 15 is s ′. And Then, the frequency f of the color moiré is expressed as a difference between an arbitrary integral multiple of the spatial frequency (1 / s') and the repetition frequency 1 / p of the sub-pixel of the same color, as shown in Expression (3).
[0043]
(Equation 1)

[0044]
From equation (3), f takes various values. Here, the maximum value f can take is 1/2 of the sampling frequency of the parallax barrier 15 projected onto the color liquid crystal display 16 from the viewpoint. This is because observing the RGB sub-pixels by the slits 12 arranged at regular intervals is a kind of sampling.
[0045]
As a result, when the distance d between the color liquid crystal display 16 and the observer 4, the distance g between the parallax barrier 15, and the pixel interval p, the upper limit value of f, the distance on the display unit as viewed from the observation position at that time s ₁ 'And the pattern (slit) interval s ₁ Is determined by the following equation.
[0046]
(Equation 2)

[0047]
Here, considering that there is a relationship of g≪d in most cases in the stereoscopic video display device 10a, the pattern interval s ₁ Has a value obtained by adding p / 2 to an integral multiple of the pixel interval p, that is, by observing the relationship of the expression (1), the period of the generated color moiré becomes the pattern interval s. ₁ It can be said that the color moiré becomes sufficiently inconspicuous. When the distance g between the color liquid crystal display 16 (display unit) and the parallax barrier 15 (screen) cannot be ignored, the distance g from the viewpoint of the observer 4 to the display unit and the distance to the screen are determined. Equation (6) having the corrected term (1-g / d) ₁ By satisfying (correction pattern interval), the same effect as above can be obtained. In addition, although the above examination was performed on the assumption that the pattern was a slit, the same applies to a cylindrical lens, a pinhole, or a lens.
[0048]
Next, the visibility of the color moiré will be specifically verified with reference to FIG. FIG. 4A shows a pixel interval p and a pattern (pinhole) interval s. ₁ FIG. 6 is a diagram for explaining color moiré that occurs when n = 2 that satisfies the relationship of Expression (1). FIG. 4A shows a color liquid crystal display 16 shown in FIG. 3 in which a pinhole plate is installed as a screen so that the arrangement direction of sub-pixels of the same color and the vertical arrangement direction of the pinholes match. And In the figure, various marks (41R, 41G, 41B) indicate the center point on the color liquid crystal display 16 where the observer's line of sight was captured when the observer observed the surface of the color liquid crystal display 16 through the pinhole. It is shown.
[0049]
Here, paying attention to the mark 41G, a row of marks 41G of the same color formed in the vertical direction has a fixed interval of 2 s. ₁ It can be seen that the pattern is repeatedly formed in the horizontal direction. That is, by satisfying the expression (1), the period of the generated color moiré is the smallest possible pattern interval, the pattern interval s. ₁ Twice as large as This is a sufficiently small interval between the moiré fringes, so that the color moiré becomes difficult to recognize and a high-quality stereoscopic image is displayed.
[0050]
As described above, in the first embodiment, a color liquid crystal display has been described as an example of the display unit constituting the stereoscopic image display device. Instead, another display having a color filter such as a PDP, and three primary color LEDs are arranged. A color LED panel, a liquid crystal panel equipped with a color filter, or a projector may be used.
[0051]
(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. 1 and FIG. Note that the basic configuration of the stereoscopic video device 10a (FIG. 1) in the present embodiment is the same as that in the first embodiment, and therefore, the description is omitted. The difference between the second embodiment and the first embodiment in the device configuration is that the pixel interval p and the pattern (slit) interval s ₂ Is that the following equation is used instead of the equation (1).
[0052]
s ₂ = (N + k / 3) p (k = 1, 2, n: integer) (7)
[0053]
By having the relationship shown in equation (7), the pattern interval s ₂ Is a value obtained by adding the sub-pixel interval q (FIG. 3) or 2q to an integer multiple of the pixel interval p. Accordingly, the period of the color moiré, which is twice the slit interval in the first embodiment, becomes three times the slit interval in the present embodiment, and three types of sub-pixels of RGB are observed through the slit 12 in order for each color. Will be visible to the person.
[0054]
Hereinafter, the pixel interval p and the pattern interval s ₂ It will be verified by mathematical expressions that the above-mentioned effect is obtained by satisfying the expression (7). Here, in order for the three color sub-pixels of RGB to be observed in order for each color, the spatial frequency 1 at the intersection connected to the color liquid crystal display 16 via the adjacent slit 12 on the line of sight from the observer 4 / S ₂ 'Should be 1/3 of that value or an integral multiple thereof. Therefore, the expression (3) is replaced by the following expression.
[0055]
[Equation 3]

[0056]
The equation (8) is further expanded to obtain the equation (7) in consideration of the relation of g≪d.
[0057]
Next, the visibility of the color moiré will be specifically verified with reference to FIG. FIG. 5A shows a pixel interval p and a pattern interval s. ₂ Is a diagram illustrating the color moiré generated by indicating the center point on the color liquid crystal display captured by the observer's viewpoint by marks (51R, 51G, 51B) when the relationship of Expression (7) is satisfied. FIG. 5A shows a case where the equation (5) is n = 2 and k = 1, and the pattern interval is s. ₁ From s ₂ 4 (a), except that it has been changed to. As is clear from FIG. 5A, the repetition interval (cycle) of the same color mark is the pattern interval s. ₂ It can be seen that RGB sub-pixels are observed in order for each color.
[0058]
The effects of the present embodiment will be described below. In the case of the first embodiment (FIG. 4A) described above, for example, when attention is paid to the sub-pixel 41G of one color, the light-dark repetition interval of the green (G) color row is the minimum possible value. 2s ₁ This is an example. In this case, if the observation position is fixed, the moire fringe period due to the G color is minimized, and color moiré is hardly recognized, and a high-quality stereoscopic image is obtained. A phenomenon in which the constituent colors change may occur.
[0059]
Therefore, the condition for avoiding the above phenomenon by slightly increasing the period of the moiré fringes is shown by the equation (7). ₂ The relationship is That is, the pattern interval s ₂ Has a relationship of (n + ／) times or (n + ２) times the pixel interval p, so that the period of the color moiré becomes the pattern interval s. ₂ It becomes three times of Then, the RGB sub-pixels are observed from the slit in order for each color, and when the observation position is changed, there is no phenomenon in which the appearance of the moiré fringe constituting color changes, and furthermore, the color moiré is inconspicuous and a high-quality stereoscopic image is displayed. Will be done.
[0060]
In the above, the case where the pixel is configured by three sub-pixels of RGB in the second embodiment has been described. However, this is generalized to the case where one pixel is configured by m sub-pixels. This will be described below. In this case, equation (3) is expanded as follows.
[0061]
(Equation 4)

[0062]
Here, considering that there is a relation of g≪d in most cases in the stereoscopic video display device 10a, the pattern interval s takes a value obtained by adding an integer multiple of the subpixel interval q to an integer multiple of the pixel interval p. That is, by satisfying the relationship of Expression (12), when one pixel on the display unit is composed of m sub-pixels, the cycle of the color moiré is m times the pattern interval s. Then, m sub-pixels are sequentially observed from the slit for each color, and when the observation position is changed, the appearance of the moiré fringe constituent colors does not change. Will be displayed. When the distance g between the color liquid crystal display 16 (display unit) and the parallax barrier 15 (screen) cannot be ignored, the distance g from the viewpoint of the observer 4 to the display unit and the distance to the screen are determined. The same effect can be obtained by satisfying the interval s (correction pattern interval) using the relationship of Expression (11) having the correction term (1-g / d).
[0063]
As described above, the parallax barrier is exemplified and described as a screen constituting the stereoscopic image display device in the second embodiment, but a lenticular sheet, a lens plate, or a pinhole plate may be used instead. In addition, a color liquid crystal display has been described as an example of the display unit, but instead of this, another display having a color filter such as a PDP, a color LED panel in which three primary color LEDs are arranged, and a projector using a liquid crystal panel having a color filter And so on.
[0064]
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. 4B and 5B. The basic configuration of the stereoscopic video apparatus according to the present embodiment is the same as that of the first embodiment shown in FIG. FIGS. 4B and 5B show the display surface of the stereoscopic image display device according to the present embodiment, except that the pattern (pinhole) array has a constant inclination. 4 (a) and FIG. 5 (a).
[0065]
In FIG. 4B and FIG. 5B, particularly, the inclination θ of the pattern is set so that the arrangement of the same color mark is at an oblique angle of 45 °, and the center point on the color display where the viewpoint of the observer is captured is set. This is indicated by marks (42R, 42G, 42B, 52R, 52G, 52B). FIG. 4B shows that the period is 2 s in the first embodiment. ₁ , And θ = tan between the same color sub-pixel arrangement direction and the pinhole vertical arrangement direction. ^-1 (P / 2s ₁ ). Similarly, FIG. 5B shows a case where the three sub-pixels of RGB form one pixel (m = 3) in the second embodiment, and the same-color sub-pixel arrangement direction and the pinhole Θ = tan between the vertical arrangement direction ^-1 (P / 3s ₂ ). These are summarized as follows.
[0066]
Conditions for setting the moire fringe inclination to 45 °
・ In the case of the first embodiment
θ = tan ^-1 (P / 2s ₁ ) (13)
・ In the case of the second embodiment
θ = tan ^-1 (Kp / ms ₂ ) (N, k: integer) (14)
(M: number of sub-pixels forming one pixel)
[0067]
As described above, by giving a constant inclination between the same color sub-pixel arrangement direction of the display unit and the vertical arrangement direction of the pattern, it has an effect of changing the inclination of the moire fringes. As an example, the case where the inclination is 45 ° is shown as Expressions (13) and (14). If the value is changed around the θ value at this time, the inclination of the moiré fringe also moves around 45 °. Further, in the present embodiment, the pattern arrangement in which the vertical and horizontal arrangement of the pinholes are not orthogonal is shown. However, considering that the value of p / s is sufficiently small in practice, FIG. A similar effect can be sufficiently obtained by slightly inclining the screen having the square lattice pattern shown in FIG.
[0068]
Thus, the effect of the moire fringes being inclined provides an effect of making it difficult to recognize color moiré as compared with the case of vertical fringes even if the moire cycle is the same. That is, in the case of the first embodiment, the horizontal frequency is f = 0.5 (1 / s). ₁ The moiré of the vertical pattern of) is inevitable, but if the pattern is oblique, it becomes more difficult to recognize the moiré.
[0069]
Although the case where the pinhole plate is used in the third embodiment has been described as an example, a lens plate in which the pinhole is replaced with a lens may be used instead. In addition, if it is considered that the pinholes are arranged continuously in the vertical direction, it is easy to recall that the same effect is exerted even in the slit row, so that a lenticular sheet or a parallax barrier is used as the screen. Is also good. Although a color liquid crystal display is exemplified and described as the display unit, other displays having a color filter such as a PDP, a color LED panel in which three primary color LEDs are arranged, and a projector using a liquid crystal panel having a color filter are used instead. And so on.
[0070]
【The invention's effect】
As described above, the stereoscopic imaging device and the stereoscopic display device according to the present invention provide the following excellent effects.
In the three-dimensional image display device according to the first aspect of the present invention, the color moiré is made less noticeable by narrowing the interval of the generated moiré fringes without adding a new configuration to the conventional device, and a high-quality three-dimensional image is displayed. Can be displayed.
In the three-dimensional image display device according to the second and third aspects of the present invention, in addition to the effect of the first aspect, it is possible to display a high-quality three-dimensional image in which the moiré fringe component color does not change even when the observation position is moved. it can.
[0071]
In the three-dimensional image display device according to the fourth aspect of the present invention, even when the space between the display unit and the screen is designed to be wide due to the structure of the device, the space between the generated moiré fringes is narrowed to make the color moiré less noticeable. It is possible to display high-quality stereoscopic video. According to the fifth aspect of the present invention, a high-quality stereoscopic image can be obtained in a stereoscopic image display device using a lenticular sheet or a parallax barrier as a screen.
According to the sixth aspect of the present invention, a high-quality stereoscopic image can be obtained in a stereoscopic image display device using a lens plate or a pinhole plate as a screen.
In the three-dimensional image display device according to the seventh aspect of the present invention, the moiré fringes generated are inclined without adding a new configuration to the conventional device, thereby giving an effect of making it difficult to visually recognize color moiré. It is possible to display high-quality stereoscopic video.
[0072]
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a configuration of a stereoscopic video display device using a parallax barrier, which is shown as an example of a screen in the present invention.
FIG. 2 is a configuration diagram showing a configuration of a stereoscopic video display device using a pinhole plate as an example of a screen in the present invention.
FIG. 3 is a partially enlarged view showing a pixel structure on a surface of a color liquid crystal display, which is shown as an example of a display unit in the present invention.
FIG. 4A is a diagram for specifically verifying the visibility of color moiré in the first embodiment.
(B) In the third embodiment, when s = (n + 0.5) p and (n = 2), it is a diagram for specifically verifying the visibility of the color moiré.
FIG. 5A is a diagram for specifically verifying the visibility of color moiré in the second embodiment.
(B) In the third embodiment, it is a figure for specifically verifying the visibility of the color moiré when s = (n + ／) p and (n = 2).
FIG. 6 is a configuration diagram when a parallax barrier is used as a screen in a conventional stereoscopic video display device.
FIG. 7 is a configuration diagram when a lenticular sheet is used as a screen in a conventional stereoscopic video display device.
[Explanation of symbols]
4 Observer
10a, 10b, 10c, 10d stereoscopic image display device
12 ₁ , 12 ₂ , ... 12 _n slit
15 Parallax Barrier
16 color liquid crystal display
22 Pinhole
25 Pinhole plate
31 pixels
62 ₁ , 62 ₂ , ... 62 _n slit
65 Parallax Barrier
66 Display
72 ₁ , 72 ₂ , ... 72 _n Cylindrical lens
75 Lenticular Sheet

Claims (7)

Pixels composed of three sub-pixels each emitting three primary colors are arranged in a plane at a fixed pixel interval, and a display unit for displaying an image and a traveling direction of light emitted from the sub-pixels of the display unit are limited. A plurality of patterns are arranged in a plane at regular intervals, and a screen that divides the image into parallax images, and a stereoscopic image display device that displays the images as stereoscopic images,
The three-dimensional image display device, wherein the patterns are arranged at a pattern interval obtained by adding half of the pixel interval to an integral multiple of the pixel interval. A display unit that displays an image by arranging pixels formed by arranging a plurality of sub-pixels at a fixed sub-pixel interval at a constant pixel interval, and the progress of light emitted from the sub-pixels of the display unit A plurality of patterns that limit the direction are arranged in a plane at regular intervals, and a screen that divides the image into parallax images, and a stereoscopic image display device that displays the images as stereoscopic images,
The three-dimensional image display device, wherein the patterns are arranged at a pattern interval obtained by adding an integral multiple of the subpixel interval to an integral multiple of the pixel interval. The three-dimensional image display device according to claim 2, wherein the number of sub-pixels forming the pixel is three, and each of the sub-pixels emits three primary colors. The pattern is arranged at a correction pattern interval obtained by correcting the pattern interval based on a ratio of a distance from a specific viewpoint to the display unit and a distance from the viewpoint to the screen. The stereoscopic video display device according to any one of claims 1 to 3. 5. The stereoscopic image display device according to claim 1, wherein the screen is a lenticular sheet formed of a cylindrical lens as the pattern or a parallax barrier formed of a row of slits. 6. The three-dimensional image display device according to any one of claims 1 to 4, wherein the screen is a lens plate made of a lens or a pinhole plate made of a pinhole as the pattern. The display unit has a vertical stripe structure in which pixels are arranged so that subpixels of the same color are continuous in the vertical direction,
The three-dimensional image display device according to claim 1, wherein a vertical arrangement direction in which the same-color sub-pixels are continuous and a vertical arrangement direction of the pattern have a certain angle. .

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