JP2010044922A - Plane light source element and light control member used for this as well as image display using it - Google Patents
Plane light source element and light control member used for this as well as image display using it Download PDFInfo
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Abstract
Description
本発明は、複数の点状光源を有する面光源素子と、これが備えるシート状の光制御部材及びこれを用いた画像表示装置に関するものであり、特に、大型で高輝度と輝度均一性が要求される照明看板装置、液晶ディスプレイ装置等に用いられる直下方式の面光源素子と、これが備える光制御部材及びこれを用いた画像表示装置に関するものである。 The present invention relates to a surface light source element having a plurality of point light sources, a sheet-like light control member provided in the surface light source element, and an image display apparatus using the same, and particularly requires a large size, high luminance and luminance uniformity. In particular, the present invention relates to a direct-type surface light source element used in an illumination signage device, a liquid crystal display device, and the like, a light control member included in the surface light source element, and an image display device using the light control member.
透過型の液晶ディスプレイ、照明看板等を背面から照明する面光源としては、エッジライト方式と直下方式がある。エッジライト方式は、導光板の端面に配置した光源からの光を、導光板によって端面と直交する主面から正面方向に取り出す方式であり、直下方式は、複数の光源を装置の背面に並べ、拡散板に光を入射し、拡散板で光を均一化して入射面と対向する出射面に光を取り出す方式である（例えば特許文献１参照）。 As a surface light source for illuminating a transmissive liquid crystal display, a lighting signboard, and the like from the back, there are an edge light method and a direct light method. The edge light method is a method of taking out light from a light source arranged on the end face of the light guide plate in a front direction from the main surface orthogonal to the end face by the light guide plate, and the direct method is arranging a plurality of light sources on the back of the device, In this method, light is incident on a diffuser plate, the light is made uniform by the diffuser plate, and the light is extracted to an exit surface opposite to the incident surface (see, for example, Patent Document 1).
テレビやパソコンのモニタでは、画像表示装置の大型化の要求が高まっており、大型の画像表示装置に使用されるの面光源素子では輝度の向上や均一性などの点で有利な直下方式が主流となっている。
直下方式の面光源素子は、光源、反射板、拡散板、レンズシート等を備えている。反射板は光源から背面側に出射した光を正面方向に反射させる機能を有している。拡散板やレンズシートは光を拡散させて光源の像を低減する機能や、拡散した光を適正な指向性に変換する機能を有している。
There is an increasing demand for large-sized image display devices in television and personal computer monitors, and direct light sources that are advantageous in terms of brightness improvement and uniformity are the mainstream for surface light source elements used in large-sized image display devices. It has become.
The direct-type surface light source element includes a light source, a reflection plate, a diffusion plate, a lens sheet, and the like. The reflection plate has a function of reflecting light emitted from the light source to the back side in the front direction. The diffusion plate and the lens sheet have a function of diffusing light to reduce the image of the light source, and a function of converting the diffused light into appropriate directivity.
光源としては、線状光源である蛍光灯が用いられてきたが、色の再現性が悪い、また水銀を使用している為に環境に負荷がかかる等の問題があった。そこで、色の再現性がよく、水銀を使用しない発光ダイオード（ＬＥＤ）等の点状光源を平面内に配置し、面状光源として用いることが提案されている（例えば、特許文献２、非特許文献１参照）。 As a light source, a fluorescent lamp, which is a linear light source, has been used, but there are problems such as poor color reproducibility and load on the environment due to the use of mercury. Therefore, it has been proposed that a point light source such as a light emitting diode (LED) that does not use mercury is arranged in a plane and used as a planar light source (for example, Patent Document 2, Non-patent). Reference 1).
しかし、点状光源を平面内に配置すると、光源像による明暗差は２次元的に生じる。更に、ＬＥＤの発光は指向性が強く、高い輝度均一性を得ることが線状光源を用いる場合よりも困難となる。また、色座標を広くする為に、赤、青、緑等の各色のＬＥＤを用いる場合には、色の均一性を得ることが困難である。拡散板の微粒子を増加させることで輝度均一性と色の均一性とを上げることが可能であるが、光の吸収や、不要な方向へ出射する光が増加し、光の利用効率が低下する為、省エネルギーの観点から好ましくない。 However, when the point light source is arranged in a plane, the contrast between the light source images is generated two-dimensionally. Furthermore, the light emission of the LED has a strong directivity, and it is more difficult to obtain high luminance uniformity than when a linear light source is used. In addition, when using LEDs of each color such as red, blue, and green in order to widen the color coordinates, it is difficult to obtain color uniformity. It is possible to increase brightness uniformity and color uniformity by increasing the fine particles of the diffusion plate, but light absorption and light emitted in unnecessary directions increase, and light use efficiency decreases. Therefore, it is not preferable from the viewpoint of energy saving.
光の利用効率を向上させ、且つ、高い輝度の均一性を得る為に、２枚のレンチキュラーレンズ形状を付与する技術が公開されている（例えば、特許文献３参照）。しかし、Ｘ軸方向での光源像の低減の為のレンチキュラーレンズと、Ｙ軸方向での光源像の低減の為のレンチキュラーレンズとの２枚を用いる為に、部材の点数が増加し、生産性が低下する、また、より光源側に配置されたレンチキュラーレンズによって、目的の方向以外にも影響を与えてしまう為に、２次元的な光源像の低減が困難である。Ｘ軸方向またはＹ軸方向の一方について輝度および／または色が不均一であると、縞状の輝度分布、色の分布となり、画面品位が悪くなるために好ましくない。 A technique for providing two lenticular lens shapes has been disclosed in order to improve the light utilization efficiency and obtain high brightness uniformity (see, for example, Patent Document 3). However, since two lenses, a lenticular lens for reducing the light source image in the X-axis direction and a lenticular lens for reducing the light source image in the Y-axis direction, are used, the number of members increases and the productivity is increased. In addition, since the lenticular lens arranged on the light source side affects other than the target direction, it is difficult to reduce the two-dimensional light source image. If the luminance and / or color is not uniform in one of the X-axis direction and the Y-axis direction, a striped luminance distribution and color distribution result, and the screen quality deteriorates.
そこで、本発明では、例えば画像表示装置等に用いられる直下型の面光源素子であって、ＬＥＤ等の点状光源を用い、高い色再現性を可能とし、高輝度で且つ輝度の均一性と色の均一性とが高く、光の利用効率が高い為に省エネルギーを実現できる面光源素子と、これが備えるシート状の光制御部材及びこれを用いた画像表示装置を提供することを目的とする。 Therefore, in the present invention, for example, a direct-type surface light source element used in an image display device or the like, which uses a point light source such as an LED, enables high color reproducibility, high brightness, and uniform brightness. An object of the present invention is to provide a surface light source element capable of realizing energy saving because of high color uniformity and high light utilization efficiency, a sheet-like light control member provided in the surface light source element, and an image display device using the surface light source member.
即ち、本発明は、以上の課題を解決すべく、以下の手段を提供する。
本願第１の発明は、
Ｘ軸と、Ｘ軸に直交するＹ軸とに平行なＸ−Ｙ平面の法線の一方をＺ軸方向として、
少なくとも、
Ｘ−Ｙ平面に平行な発光面と、複数の点状光源と、１枚のシート状、またはフィルム状の光制御部材を備え、
前記複数の点状光源が、前記Ｘ−Ｙ平面に平行な仮想平面内に配置され、
前記光制御部材が、前記Ｘ−Ｙ平面に平行に、且つ、前記複数の点状光源のＺ軸方向側に配置され、
前記発光面が、前記光制御部材のＺ軸方向側に配置されている面光源素子であって、
前記光制御部材の主に光が出射する面に、複数の凸部を備えており、
前記複数の凸部の、
Ｘ−Ｚ平面と平行な任意の平面における断面形状が一定であり、
且つ、
Ｙ−Ｚ平面と平行な任意の平面における断面形状が一定である
ことを特徴とする面光源素子である。
That is, the present invention provides the following means in order to solve the above problems.
The first invention of the present application is
One of the normals of the XY plane parallel to the X axis and the Y axis orthogonal to the X axis is defined as the Z axis direction.
at least,
A light emitting surface parallel to the XY plane, a plurality of point light sources, and a sheet-like or film-like light control member,
The plurality of point light sources are arranged in a virtual plane parallel to the XY plane,
The light control member is arranged in parallel to the XY plane and on the Z-axis direction side of the plurality of point light sources,
The light-emitting surface is a surface light source element disposed on the Z-axis direction side of the light control member,
The light control member has a plurality of convex portions on the surface from which light is emitted mainly,
The plurality of convex portions,
The cross-sectional shape in an arbitrary plane parallel to the XZ plane is constant,
and,
A surface light source element having a constant cross-sectional shape in an arbitrary plane parallel to the YZ plane.
また、本願第２の発明は、上記第１の発明の面光源素子であって、
前記複数の点状光源が、Ｘ軸方向に周期的に配列され、且つＹ軸方向に周期的に配列されていることを特徴とする面光源素子である。
The second invention of the present application is the surface light source element of the first invention,
The surface light source element, wherein the plurality of point light sources are periodically arranged in the X-axis direction and periodically arranged in the Y-axis direction.
また、本願第３の発明は、上記第２または第３の発明の面光源素子であって、
前記複数の凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線が、楕円または放物線または多項式からなる曲線の一部からなり、
且つ、
Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線が、楕円または放物線または多項式からなる曲線の一部からなることを特徴とする面光源素子である。
The third invention of the present application is the surface light source element of the second or third invention,
The contour line of the cross-sectional shape in a plane parallel to the XZ plane of the plurality of convex portions consists of a part of a curve made of an ellipse, a parabola, or a polynomial,
and,
The surface light source element is characterized in that an outline of a cross-sectional shape in a plane parallel to the YZ plane is formed of a part of a curve made of an ellipse, a parabola, or a polynomial.
また、本願第４の発明は、上記のいずれかの面光源素子であって、
前記複数の凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の幅ａ１と、輪郭線の高さｂ１の比ｂ１／ａ１が０．２８〜０．６５であり、
且つ、
Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の幅ａ２と、輪郭線の高さｂ２の比ｂ２／ａ２が０．２８〜０．６５であることを特徴とする面光源素子である。
Moreover, 4th invention of this application is any one of said surface light source elements,
The ratio b 1 / a 1 of the contour line width a 1 and the contour line height b 1 in a plane parallel to the XZ plane of the plurality of convex portions is 0.28 to 0.65. Yes,
and,
A surface having a ratio b 2 / a 2 of a contour line width a 2 and a contour line height b 2 in a plane parallel to the YZ plane is 0.28 to 0.65. It is a light source element.
また、本願第４の発明は、上記のいずれかの面光源素子であって、
前記複数の凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度θ１が、５０度〜８２度であり、
且つ、
Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度θ２が、５０度〜８２度であることを特徴とする面光源素子である。
Moreover, 4th invention of this application is any one of said surface light source elements,
The maximum inclination angle θ1 of the contour line of the cross-sectional shape in a plane parallel to the XZ plane of the plurality of convex portions is 50 degrees to 82 degrees,
and,
The surface light source element is characterized in that the maximum inclination angle θ2 of the contour line of the cross-sectional shape in a plane parallel to the YZ plane is 50 degrees to 82 degrees.
また、本願第６の発明は、 上記のいずれかの面光源素子が備える、シート状、又はフィルム状の光制御部材である。 Moreover, 6th invention of this application is a sheet-like or film-like light control member with which one of said surface light source elements is provided.
また、本願第７の発明は、本発明の面光源素子の発光面上に透過型表示装置を配置することを特徴とする画像表示装置である。 The seventh invention of the present application is an image display device characterized in that a transmissive display device is arranged on the light emitting surface of the surface light source element of the present invention.
以下に、本発明の効果について詳細に説明する。 The effects of the present invention will be described in detail below.
本発明の面光源素子は、点状光源を用いることによって高い色再現性を有し、光を拡散させる微粒子を分散させた拡散板を、複数の凸部を有した１枚のシート状、又はフィルム状の光制御部材に置き換えて、２次元的に光線方向を制御することによって、高い輝度均一性と色の均一性とを得る。本発明では、光制御部材の入射面上の全ての点で、入射した光が出射する方向を同様に制御する一様な性質を持たせることで、サイズ変更に有利なだけでなく、光源との位置合わせも不要となる。更に光制御部材の持つ輝度均一性、輝度向上効果などの複合的な機能により、他の機能性光学フィルムの利用の解消もしくは削減が可能となり、生産性や薄型化にも有利となる。また、面光源素子の発光面上に透過型表示装置を配置することによって、高い色再現性を有し、輝度の均一性と色の均一性とが高い、高品位な画像表示装置が得られる。 The surface light source element of the present invention has a high color reproducibility by using a point light source, a diffuser plate in which fine particles for diffusing light are dispersed, a sheet having a plurality of convex portions, or High luminance uniformity and color uniformity are obtained by replacing the film-like light control member in two dimensions to control the direction of the light beam. In the present invention, it is not only advantageous for the size change by giving a uniform property that similarly controls the direction in which the incident light is emitted at all points on the incident surface of the light control member, It is not necessary to align the position. Furthermore, the combined functions of the light control member, such as brightness uniformity and brightness enhancement effect, make it possible to eliminate or reduce the use of other functional optical films, which is advantageous for productivity and thickness reduction. In addition, by disposing a transmissive display device on the light emitting surface of the surface light source element, a high-quality image display device having high color reproducibility and high luminance uniformity and color uniformity can be obtained. .
本発明が提供する面光源素子は、Ｘ軸と、Ｘ軸に直交するＹ軸とに平行なＸ−Ｙ平面に平行な発光面を持つ面光源素子であって、該面光源素子は、Ｘ−Ｙ平面に平行な仮想平面内に配置された複数の点状光源と、１枚のシート状、又はフィルム状の光制御部材とを備えており、前期光制御部材によって、光源像を２次元的に低減し、高い輝度の均一性と色の均一性とを得ることが出来る。 A surface light source element provided by the present invention is a surface light source element having a light emitting surface parallel to an XY plane parallel to an X axis and a Y axis orthogonal to the X axis. -It has a plurality of point light sources arranged in a virtual plane parallel to the Y plane, and one sheet-like or film-like light control member. Therefore, high brightness uniformity and color uniformity can be obtained.
点状光源からの光は、点状光源の直上ではＺ軸から小さい角度で光制御部材に入射し、点状光源から離れた位置では、Ｚ軸から大きな角度で光制御部材に入射する。光制御部材に入射した光の光線方向を、光制御部材の出射面に設けた凸部によってＺ軸方向に向けることによって点状光源の像を低減することが可能である。 The light from the point light source is incident on the light control member at a small angle from the Z axis immediately above the point light source, and is incident on the light control member at a large angle from the Z axis at a position away from the point light source. It is possible to reduce the image of the point light source by directing the light ray direction of the light incident on the light control member in the Z-axis direction by a convex portion provided on the exit surface of the light control member.
本発明の光制御部材における、光線方向を制御する原理を図２に示す。点状光源から離れた位置から入射した光線は光制御部材の入射面と出射面において屈折し、その方向が変化する。この際、出射面に凸部を設けることにより、凸部の斜面で屈折し、Ｚ軸方向からの角度が小さい、より正面方向に偏向して出射する。 FIG. 2 shows the principle of controlling the light beam direction in the light control member of the present invention. A light beam incident from a position away from the point light source is refracted on the incident surface and the output surface of the light control member, and the direction thereof changes. At this time, by providing a convex portion on the exit surface, the light is refracted on the slope of the convex portion, and the angle from the Z-axis direction is small, and the light is deflected and emitted in the front direction.
本発明では、凸部によって光制御部材のすべての面でＸ軸方向、Ｙ軸方向の光線の制御を可能とし、２次元的に光源像を消去が実現される。更に、凸部のＸ−Ｚ平面に平行な任意の平面における断面形状を一定とし、且つ、Ｙ−Ｚ平面に平行な任意の平面における断面形状を一定とすることによって、光制御部材のすべての位置でＸ軸方向及びＹ軸方向に沿った光線の制御が可能となり、効率的に光をＺ軸方向付近に偏向させることによって高い輝度の均一性を得ることができる。 In the present invention, the convex portions can control the light beams in the X-axis direction and the Y-axis direction on all surfaces of the light control member, and the light source image can be erased two-dimensionally. Furthermore, by making the cross-sectional shape in an arbitrary plane parallel to the XZ plane of the convex portion constant and making the cross-sectional shape in an arbitrary plane parallel to the YZ plane constant, all the light control members Light can be controlled along the X-axis direction and the Y-axis direction at the position, and high brightness uniformity can be obtained by efficiently deflecting light in the vicinity of the Z-axis direction.
また、特定の色を発光する点状光源を多種類用いる場合、それぞれの色について、上記分布を一定にすることによって、高い色の均一性が達成される。 In addition, when many types of point light sources that emit light of a specific color are used, high color uniformity is achieved by making the distribution constant for each color.
本発明の面光源素子は、点状光源の配置が２次元方向（Ｘ軸方向及びＹ軸方向）に沿って分布している場合であっても、Ｘ軸方向及びＹ軸方向に沿った光線方向の制御を可能である凸部を備えた光制御部材を使用することによって、１枚の光制御部材で２次元的に光線を制御し、良好な輝度均一性と色の均一性とを共に実現できる。また、高い輝度の均一性を得ることによって、より薄型化が容易となり、且つ生産性が向上する。また、Ｚ軸方向により光を偏向させることが可能である為、Ｚ軸方向の輝度が向上し、より品位の良い面光源素子を得ることができる。 The surface light source element of the present invention has a light beam along the X-axis direction and the Y-axis direction even when the arrangement of the point light sources is distributed along the two-dimensional direction (X-axis direction and Y-axis direction). By using a light control member with a convex portion that can control the direction, light is controlled two-dimensionally with a single light control member, and both good brightness uniformity and color uniformity are achieved. realizable. In addition, by obtaining high luminance uniformity, the thickness can be easily reduced and the productivity can be improved. Further, since light can be deflected in the Z-axis direction, the luminance in the Z-axis direction is improved, and a surface light source element with higher quality can be obtained.
複数の凸部の、Ｘ−Ｚ平面と平行な任意の平面における断面形状が一定であり、且つ、Ｙ−Ｚ平面と平行な任意の平面における断面形状が一定である形状とは、例えば、凸部のＸ軸、Ｙ軸、Ｚ軸方向の座標をそれぞれｘ、ｙ、ｚとして、
ｚ（ｘ、ｙ）＝ｆ（ｘ）＋ｇ（ｙ） （１）
と表すことができる。ここで、ｆ（ｘ）、ｇ（ｙ）とは、それぞれ凸部のＹ−Ｚ平面、Ｘ−Ｚ平面における断面形状の輪郭線を表現する関数である。
The shape of the plurality of protrusions having a constant cross-sectional shape in an arbitrary plane parallel to the XZ plane and a constant cross-sectional shape in an arbitrary plane parallel to the YZ plane is, for example, convex The coordinates of the X-axis, Y-axis, and Z-axis directions of the part are respectively x, y, and z,
z (x, y) = f (x) + g (y) (1)
It can be expressed as. Here, f (x) and g (y) are functions expressing contour lines of a cross-sectional shape in the YZ plane and XZ plane of the convex portions, respectively.
本願第２の発明は、複数の点状光源をＸ軸方向及びＹ軸方向に周期的に配列することによって、面光源素子の発光面において同じ輝度と色とを実現することが可能である。また、点状光源を周期的に配列することによって、面光源素子の発光面の全ての面で高い輝度の均一性と色の均一性と得ることができる。 According to the second aspect of the present invention, the same luminance and color can be realized on the light emitting surface of the surface light source element by periodically arranging a plurality of point light sources in the X-axis direction and the Y-axis direction. Further, by periodically arranging the point light sources, high luminance uniformity and color uniformity can be obtained on all the light emitting surfaces of the surface light source element.
本願第３の発明は、光制御部材における凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線と、Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線とを滑らかな曲線とすることによって、連続的で滑らかに点状光源からの光を広げることが可能であり、滑らかで均一な輝度と色の分布を実現できる。また、滑らかな曲面で凸部を形成することによって、成形性が良好で破損しにくい等の高い生産性と耐久性が実現される。 According to the third invention of the present application, the contour of the cross section in the plane parallel to the XZ plane and the contour of the cross section in the plane parallel to the YZ plane of the convex portion of the light control member are smoothly curved. By doing so, it is possible to spread the light from the point light source continuously and smoothly, and a smooth and uniform luminance and color distribution can be realized. Further, by forming the convex portion with a smooth curved surface, high productivity and durability such as good moldability and less damage are realized.
本願第４の発明は、光制御部材における凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の幅と輪郭線の高さの比ｂ１／ａ１と、Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の幅と輪郭線の高さの比ｂ２／ａ２を０．２８〜０．６５とすることによって効果的に光源像を低減し、輝度と色の均一性を高めることが可能である。また凸部の断面形状の幅と高さの比が特定範囲であるので、成形性が良好であり、高い生産性が実現される。ここで、凸部の断面形状における輪郭線の幅と高さとは、輪郭線全体が存在する高さには依存せず、例えば図３に示すようにとる。 The fourth invention of the present application relates to the ratio b 1 / a 1 of the width of the contour line and the height of the contour line in the plane parallel to the XZ plane of the convex portion of the light control member, and the YZ plane. By reducing the ratio b 2 / a 2 between the width of the contour line of the cross-sectional shape and the height of the contour line in a plane parallel to the plane from 0.28 to 0.65, the light source image is effectively reduced, and the luminance and color It is possible to increase the uniformity. Moreover, since the ratio of the width and height of the cross-sectional shape of the convex portion is within a specific range, the moldability is good and high productivity is realized. Here, the width and height of the contour line in the cross-sectional shape of the convex portion do not depend on the height at which the entire contour line exists, and are, for example, as shown in FIG.
本願第５の発明は、光制御部材における凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度θ１と、Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度θ２とを５０〜８２度とすることによって、点状光源からＸ軸方向及びＹ軸方向に沿って離れた位置において、光制御部材にＺ軸方向に対して斜めに入射した光を多く正面付近に向けることが可能であり、光源像を低減し、高い輝度の均一性と色の均一性と、高い輝度を実現することが可能である。更に凸部のＸ−Ｚ平面とＹ−Ｚ平面における断面形状の最大傾斜角を５０〜８２度とすることにより、成形性が良好となり、高い生産性が実現できる。 The fifth invention of the present application is the maximum inclination angle θ 1 of the contour line of the cross-sectional shape in the plane parallel to the XZ plane, and the contour of the cross-sectional shape in the plane parallel to the YZ plane. By making the maximum inclination angle θ 2 of the line 50 to 82 degrees, the light is incident on the light control member obliquely with respect to the Z-axis direction at a position away from the point light source along the X-axis direction and the Y-axis direction. Therefore, it is possible to direct a large amount of the light to the vicinity of the front, reduce the light source image, and realize high brightness uniformity, color uniformity, and high brightness. Furthermore, when the maximum inclination angle of the cross-sectional shape in the XZ plane and the YZ plane of the convex portion is 50 to 82 degrees, the moldability becomes good and high productivity can be realized.
本願第６の発明は、上記のいずれかの面光源素子が備える、Ｘ軸またはＹ軸に沿って光線方向を制御する光制御手段を有するシート状、又はフィルム状の光制御部材である。光制御部材を用いることによって、点状光源から正面方向に出射する光の分布を制御し、高い輝度の均一性と、高い色の均一性を実現した面光源素子を得ることが可能である。 A sixth invention of the present application is a sheet-like or film-like light control member having a light control means for controlling a light beam direction along the X-axis or Y-axis, which is included in any of the surface light source elements described above. By using the light control member, it is possible to control the distribution of light emitted from the point light source in the front direction and to obtain a surface light source element that realizes high luminance uniformity and high color uniformity.
本願第７の発明は、上記のいずれかの面光源素子の発光面上に透過型の表示装置を配置することによって構成される画像表示装置である。前記面光源素子は正面方向への輝度の均一性と、色の均一性とが高い面光源素子であり、この発光面上に透過型の表示装置を配置することによって、色の再現性が良く、輝度と色の均一性が高いことから高品位な画像を実現することが可能である。ここで本発明の画像表示装置とは、面光源素子と表示素子を組み合わせた表示モジュール、更には、この表示モジュールを用いた少なくとも画像表示機能を有する機器であり、テレビ、パソコンモニタや広告看板等を含む。 A seventh invention of the present application is an image display device configured by disposing a transmissive display device on the light emitting surface of any one of the above surface light source elements. The surface light source element is a surface light source element that has high luminance uniformity and color uniformity in the front direction. By arranging a transmissive display device on the light emitting surface, color reproducibility is improved. Since the luminance and color uniformity are high, a high-quality image can be realized. Here, the image display device of the present invention is a display module in which a surface light source element and a display element are combined, and further a device having at least an image display function using the display module, such as a television, a personal computer monitor, an advertisement signboard, etc. including.
本発明の最良の形態の一例を図１に示す。Ｘ軸と、Ｘ軸に直交するＹ軸とに平行なＸ−Ｙ平面の法線の一方をＺ軸方向として、少なくともＸ−Ｙ平面に平行な発光面と、複数の点状光源と、Ｘ−Ｚ平面の断面形状が一定であり、且つ、Ｙ−Ｚ平面の断面形状が一定である凸部を有する光制御部材とを備えた面光源素子である。 An example of the best mode of the present invention is shown in FIG. One of the normal lines of the XY plane parallel to the X axis and the Y axis orthogonal to the X axis is defined as the Z axis direction, and at least a light emitting surface parallel to the XY plane, a plurality of point light sources, A surface light source element including a light control member having a convex portion having a constant cross-sectional shape in the −Z plane and a constant cross-sectional shape in the YZ plane.
本発明の点状光源としては特に制限はないが、ＬＥＤ等を用いることができる。ＬＥＤの形態としては、白色ＬＥＤや、赤、青、緑等各色のＬＥＤ等があるが、白色のみを用いる、また各色ＬＥＤを周期的に配列することなどがあげられる。 Although there is no restriction | limiting in particular as a point light source of this invention, LED etc. can be used. Examples of the LED include a white LED and LEDs of each color such as red, blue, and green. Only white is used, and each color LED is periodically arranged.
また点状光源を周期的に配列する場合は、１周期に同じ色の点状光源を複数配置しても良い。これによって、面光源素子の発光面における色や輝度を調整することが可能であり、また、同じ色の中での点状光源の中での輝度のばらつきによる輝度の均一性低下と、色の均一性低下とを低減することが可能である。 When the point light sources are arranged periodically, a plurality of point light sources having the same color may be arranged in one cycle. As a result, it is possible to adjust the color and brightness on the light emitting surface of the surface light source element, and also to reduce the uniformity of brightness due to the variation in brightness among the point light sources in the same color. It is possible to reduce the uniformity degradation.
点状光源として、緑色の点状光源、赤色の点状光源、青色の点状光源以外の色の点状光源を用いても良い。他の色の点状光源を用いることによって、更に高い輝度、高い色再現性を得ることが可能である。 A point light source of a color other than a green point light source, a red point light source, or a blue point light source may be used as the point light source. By using a point light source of another color, it is possible to obtain higher luminance and higher color reproducibility.
点状光源を周期的に配列する場合に、１周期内での点状光源の配置としては様々な形態が考えられるが、本発明に用いることが出来る一例を図に示す。図７は３色の点状光源を三角形に配置した例である。図８は４色の点状光源を四角形に配置した例である。図９は３色の点状光源を直線状に配置した例である。 In the case where the point light sources are arranged periodically, various forms are conceivable as the arrangement of the point light sources within one cycle. An example that can be used in the present invention is shown in the figure. FIG. 7 shows an example in which three color point light sources are arranged in a triangle. FIG. 8 shows an example in which four color point light sources are arranged in a square shape. FIG. 9 shows an example in which three color point light sources are arranged in a straight line.
点状光源の配置としては様々な形態が考えられるが、本発明に用いることが出来る一例を図に示す。図４は各点状光源が長方形に配置された例ある。図５は各点状光源が千鳥配列された例の一つである。図５ではある点状光源に隣り合う最も近い点状光源は４つあり、それぞれ斜め４５度方向にある。図６も各点状光源が千鳥配列された例の一つである。図６ではある点状光源に隣り合う最も近い点状光源は６つあり、正６角形を成している。 Although various forms can be considered as the arrangement of the point light source, an example that can be used in the present invention is shown in the drawing. FIG. 4 shows an example in which each point light source is arranged in a rectangular shape. FIG. 5 shows an example in which the point light sources are arranged in a staggered manner. In FIG. 5, there are four nearest point light sources adjacent to a certain point light source, and each is in an oblique 45 degree direction. FIG. 6 is also an example in which the point light sources are arranged in a staggered manner. In FIG. 6, there are six closest point light sources adjacent to a certain point light source, and form a regular hexagon.
Ｘ軸方向に沿った、隣り合う点状光源と点状光源の距離と、Ｙ軸方向に沿った、隣り合う点状光源と点状光源の距離は、短いほうが輝度の均一性と色の均一性とがよく、高い輝度が得られる為、望ましい。しかし、周期が短すぎると点状光源の個数が増加し、消費電力の増加、また発熱の問題が発生する。Ｘ軸方向及びＹ軸方向に沿った、隣り合う点状光源と点状光源の距離は７ｍｍから７０ｍｍが望ましい。より望ましくは１５ｍｍから５０ｍｍである。 The shorter the distance between the adjacent point light sources and the point light source along the X-axis direction and the distance between the adjacent point light sources and the point light source along the Y-axis direction, the more uniform the luminance and the color. It is desirable because of its good characteristics and high luminance. However, if the period is too short, the number of point light sources increases, resulting in an increase in power consumption and a problem of heat generation. The distance between adjacent point light sources and point light sources along the X-axis direction and the Y-axis direction is preferably 7 mm to 70 mm. More desirably, the thickness is 15 mm to 50 mm.
点状光源と光制御部材との距離は長いほうが、輝度の均一性と色の均一性とが高い為に、望ましい。しかし、長すぎると、装置全体の厚みが大きくなる為に好ましくない。点状光源と光制御部材との距離は５ｍｍから５０ｍｍが好ましい。より望ましくは１０ｍｍから３０ｍｍである。 A longer distance between the point light source and the light control member is desirable because of high brightness uniformity and color uniformity. However, if the length is too long, the thickness of the entire apparatus increases, which is not preferable. The distance between the point light source and the light control member is preferably 5 mm to 50 mm. More desirably, the thickness is 10 mm to 30 mm.
光制御部材における凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の幅と輪郭線の高さの比ｂ１／ａ１が０．２８より小さい場合には、Ｘ−Ｚ平面において点状光源からＺ軸方向に対して傾いた角度で入射した光を効率的に正面方向に偏向させることができず、輝度の均一性と色の均一性とを得ることが困難である。また同様に、Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の幅と輪郭線の高さの比ｂ２／ａ２が０．２８より小さい場合においても、輝度の均一性と色の均一性とを得ることが困難である。一方で、ｂ１／ａ１、ｂ２／ａ２が０．６５よりも大きい場合には、凸部の成形が困難であり、生産性が低下する。ｂ１／ａ１、ｂ２／ａ２が０．２８から０．６５である場合に効率的に点状光源からの光をＺ軸方向付近に出射させることが可能であり、且つ生産性の高い面光源素子が得られる。ｂ１／ａ１、ｂ２／ａ２は０．３０から０．６２がより好適であり、更には０．３２から０．５９が望ましい。 When the ratio b 1 / a 1 of the contour line width to the contour line height in the plane parallel to the XZ plane of the convex portion of the light control member is smaller than 0.28, XZ Light incident from a point light source at an angle with respect to the Z-axis direction on the plane cannot be efficiently deflected in the front direction, and it is difficult to obtain luminance uniformity and color uniformity. . Similarly, even when the ratio b 2 / a 2 between the width of the contour line and the height of the contour line in a plane parallel to the YZ plane is smaller than 0.28, the luminance uniformity and the color It is difficult to obtain uniformity. On the other hand, when b 1 / a 1 and b 2 / a 2 are larger than 0.65, it is difficult to form the convex portion, and the productivity is lowered. When b 1 / a 1 and b 2 / a 2 are 0.28 to 0.65, it is possible to efficiently emit light from a point light source in the vicinity of the Z-axis direction, and to improve productivity. A high surface light source element is obtained. b 1 / a 1 and b 2 / a 2 are more preferably 0.30 to 0.62, and further preferably 0.32 to 0.59.
光制御部材における凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度θ１と、Ｙ−Ｚ平面における断面形状の輪郭線の最大傾斜角度θ２とが過度に小さいと、点状光源からＺ軸方向に対して小さい角度で光制御部材に入射した光のみを正面方向に出射させることになる為、点状光源から離れた位置でＺ軸方向付近に出射する光が少なくなり、輝度の均一性と色の均一性との実現が困難になる場合がある。一方で最大傾斜角が過度に大きいと、点状光源からＺ軸方向に対して大きな角度で光制御部材に入射した光も正面方向に偏向させることが可能であるが、成形がより困難となり、生産性が低下する。θ１、θ２が５０〜８２度である場合に、輝度の均一性と色の均一性とが高く、成形性のよい、生産性の高い面光源素子を得ることが可能である。θ１、θ２は、より好適には５３〜７５度であり、更に望ましくは、６０〜７２度である。 The convex portion in the light control member, X-Z plane and the maximum inclination angle theta 1 of the cross-sectional shape of the contour line in a plane parallel, the maximum inclination angle theta 2 and is excessively cross-sectional shape of the contour lines in the Y-Z plane If it is small, only the light incident on the light control member from the point light source at a small angle with respect to the Z-axis direction is emitted in the front direction, so that it is emitted near the Z-axis direction at a position away from the point light source. Light may be reduced and it may be difficult to achieve brightness uniformity and color uniformity. On the other hand, if the maximum inclination angle is excessively large, it is possible to deflect light incident on the light control member at a large angle with respect to the Z-axis direction from the point light source, but it becomes more difficult to mold, Productivity decreases. When θ 1 and θ 2 are 50 to 82 degrees, it is possible to obtain a surface light source element with high luminance uniformity and color uniformity, good moldability, and high productivity. θ 1 and θ 2 are more preferably 53 to 75 degrees, and still more preferably 60 to 72 degrees.
光制御部材の厚さは薄いほうが望ましいが、直下方式である本発明の面光源素子では光源と光制御部材との間に空間が設けられている為に、最も光源側に配置される光制御部材は撓みや変形のない強度を有する厚さであることが望ましい。光制御部材は、面光源素子の大きさによって異なるが、厚さは０．５ｍｍから５ｍｍが望ましい。これより薄いと光制御部材の撓みや変形を生じ、点状光源と光制御部材が接触し、外観品位の低下が生じる。またこれより厚いと、面光源素子が厚くなり、重量も増加する。更に望ましくは１ｍｍから４ｍｍであり、より好ましくは１．５ｍｍから２．５ｍｍである。この範囲において、強度が保たれ、更に主面面積あたりの使用基材量の増加による製造コストの上昇を抑えることが可能である。 Although it is desirable that the thickness of the light control member is thin, in the surface light source element of the present invention which is a direct type, since a space is provided between the light source and the light control member, the light control disposed closest to the light source side It is desirable that the member has a thickness that does not cause bending or deformation. Although the light control member varies depending on the size of the surface light source element, the thickness is preferably 0.5 mm to 5 mm. If it is thinner than this, the light control member will be bent or deformed, the point light source will come into contact with the light control member, and the appearance quality will deteriorate. On the other hand, if it is thicker than this, the surface light source element becomes thick and the weight increases. Further, it is desirably 1 mm to 4 mm, and more preferably 1.5 mm to 2.5 mm. In this range, the strength is maintained, and furthermore, an increase in manufacturing cost due to an increase in the amount of the base material used per main surface area can be suppressed.
凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の幅ａ１と、Ｙ−Ｚ平面における断面形状の輪郭線の幅ａ２は、１０μｍから５００μｍが望ましい。５００μｍより大きいと出射面からパターンそのものが視認され、外観品位が低下する。また、１０μｍより小さいと回折現象により着色し外観品位の低下を招く。より好ましくは２０μｍから４００μｍであり、更に望ましくは４０μｍから３００μｍである。この範囲ではパターンそのものが観察され難く、また、作製が容易となり生産性が向上する。更に、本発明の面光源素子の発光面上に透過型表示装置を設ける画像表示装置では、ａ１、ａ２は、透過型表示装置の画素ピッチの１／１００から１／１．５の範囲にあることが望ましい。これより大きいと、画素ピッチとの干渉縞が発生し外観品位が低下する。 The width a 1 of the contour line of the cross-sectional shape in the plane parallel to the XZ plane and the width a 2 of the contour line of the cross-sectional shape in the YZ plane are preferably 10 μm to 500 μm. If it is larger than 500 μm, the pattern itself is visually recognized from the exit surface, and the appearance quality is lowered. On the other hand, if it is smaller than 10 μm, it is colored by the diffraction phenomenon and the appearance quality is lowered. More preferably, it is 20 μm to 400 μm, and further desirably 40 μm to 300 μm. Within this range, the pattern itself is difficult to observe, and the production is facilitated and the productivity is improved. Further, in the image display device in which the transmissive display device is provided on the light emitting surface of the surface light source element of the present invention, a 1 and a 2 are in the range of 1/100 to 1 / 1.5 of the pixel pitch of the transmissive display device. It is desirable to be in If it is larger than this, interference fringes with the pixel pitch are generated and the appearance quality is lowered.
光制御部材の製造方法としては、特に制限はないが、押出成形、射出成形、紫外線硬化樹脂を使用した２Ｐ（Ｐｈｏｔｏ Ｐｏｌｙｍｅｒｉｚａｔｉｏｎ）成形が上げられるが、凸部の大きさ、凸部の形状、量産性当を考慮して適した成形方法を選択すればよい。主面が大きい場合には、押出成形が適している。 Although there is no restriction | limiting in particular as a manufacturing method of a light control member, Extrusion molding, injection molding, 2P (Photo Polymerization) shaping | molding which uses an ultraviolet curable resin can be raised, but the magnitude | size of a convex part, the shape of a convex part, mass production A suitable molding method may be selected in consideration of the appropriateness. When the main surface is large, extrusion molding is suitable.
光制御部材の材料としては、通常の光学透明材料であれば用いることが可能である。例えば、メタアクリル樹脂、ポリスチレン樹脂、ポリカーボネート樹脂、シクロオレフィン樹脂、メタアクリル−スチレン共重合樹脂、シクロオレフィン−アルケン共重合樹脂等が挙げられる。 As a material of the light control member, any ordinary optical transparent material can be used. For example, methacrylic resin, polystyrene resin, polycarbonate resin, cycloolefin resin, methacryl-styrene copolymer resin, cycloolefin-alkene copolymer resin and the like can be mentioned.
より多くの光を利用する為に、光源の背面に反射板等を用いても良い。反射板を用いることによって、光源から背面方向に出射した光、光制御部材によって背面方向に出射した光をＺ軸方向に向け、より多くの光を利用することができ、高い輝度を得ることが可能である。 In order to use more light, a reflector or the like may be used on the back surface of the light source. By using the reflector, light emitted from the light source in the back direction, light emitted in the back direction by the light control member can be directed in the Z-axis direction, more light can be used, and high brightness can be obtained. Is possible.
反射板は、光源から背面側に出社した光を正面方向に反射させる機能を持つ。反射率は９５％以上のものが光の利用効率が高く望ましい。反射板の材質は、アルミ、銀、ステンレスなどの金属箔や、白色塗装、発泡ＰＥＴ樹脂などが挙げられる。光の利用効率を高める為には材質の反射率が高いものが望ましい。これには銀、発泡ＰＥＴなどが挙げられる。また、輝度の均一性と色の均一性とを高める為には、材質は拡散反射をするものが望ましい。これには発泡ＰＥＴなどが挙げられる。 The reflection plate has a function of reflecting light coming from the light source to the back side in the front direction. A reflectance of 95% or more is desirable because of high light utilization efficiency. Examples of the material of the reflecting plate include metal foils such as aluminum, silver, and stainless steel, white coating, and foamed PET resin. In order to increase the light utilization efficiency, it is desirable that the material has a high reflectance. This includes silver, foamed PET, and the like. In order to improve the uniformity of brightness and the uniformity of color, it is desirable that the material be diffusely reflected. This includes foamed PET and the like.
また、より輝度の均一性と色の均一性を高める為に、本発明の光制御部材に光拡散手段を設けても良い。光拡散手段としては、光制御部材の主面にシボやエンボスなどのランダムな凹凸を設ける方法、少量の光を拡散させる微粒子を構造物の内部に設ける方法、拡散シートを光制御部材の入射面側及び／または出射面側に設ける方法、またはこれらの組み合わせた方法が挙げられる。 Further, in order to further improve the uniformity of brightness and the uniformity of color, the light control member of the present invention may be provided with a light diffusion means. As the light diffusing means, a method of providing random irregularities such as embossing and embossing on the main surface of the light control member, a method of providing fine particles that diffuse a small amount of light inside the structure, and a diffusion sheet as the incident surface of the light control member The method of providing in the side and / or the output surface side, or the method which combined these is mentioned.
ランダムな凹凸は微粒子を分散させた溶液のスプレー等での主面への塗布、微粒子を分散させた樹脂の押出しによる成形、凹凸の形成された金型からの転写により実現可能である。 Random irregularities can be realized by applying a solution in which fine particles are dispersed to the main surface by spraying, molding by extrusion of a resin in which fine particles are dispersed, and transferring from a mold having irregularities.
光を拡散させる微粒子を構造物の内部に設ける場合には、微粒子の濃度は通常の拡散板と比べて低く抑えることが可能であり、微粒子の基材や粒径は通常の光拡散材として微粒子拡散板等に用いられているものであれば好適に用いることができる。好適な微粒子の濃度は材料によって異なるが、例えば、メタアクリル酸メチル−スチレン共重合体に、シロキサン系重合体粒子を０．４重量％分散させることなどが挙げられる。 When fine particles for diffusing light are provided inside the structure, the concentration of the fine particles can be kept lower than that of a normal diffusion plate. Any material used for a diffusion plate or the like can be preferably used. The preferred concentration of fine particles varies depending on the material, and examples thereof include dispersing 0.4% by weight of siloxane polymer particles in a methyl methacrylate-styrene copolymer.
また、より輝度の均一性と色の均一性とを得る為に拡散シート、高い正面方向の輝度を得る為にプリズムシートや偏向分離フィルム等を用いても良い。 In addition, a diffusion sheet may be used to obtain more uniform brightness and color uniformity, and a prism sheet, a deflection separation film, or the like may be used to obtain high frontal brightness.
また、光制御部材の光源側に重ねて、樹脂やガラス等からなる透明な支持基板も設けても良い。前記支持基板を配することによって、光制御部材を例えば０．１ｍｍから１ｍｍと薄くしても撓みや変形等を防止することが可能である。光制御部材を薄くすることによって、押出成形等による成形が更に容易になり、生産性が向上する。また、面光源素子が大型化するに従い次第に困難になる光制御部材の支持を容易にする。前記支持基板の厚さに特に制限は無いが、通常１ｍｍから５ｍｍであり、軽量化と強度の兼ね合いから通常２ｍｍから４ｍｍの範囲であることが更に望ましい。前記支持基板は、内部に光を拡散させる微粒子を分散したり、表面に型押ししたり微粒子を塗布することによって拡散性を高めても良い。内部に微粒子を分散させる場合や表面に型押しする場合には、基材は熱可塑性樹脂であることが生産上好ましく、好適な材料は光制御部材と同等である。また支持基板は光制御部材と接合されていても良く、例えば透明な接着剤等で接合することができ、これによって面光源素子の組立工程が簡素化し、更には光制御部材のずれや皺の発生が防止できる。 In addition, a transparent support substrate made of resin, glass, or the like may be provided on the light source side of the light control member. By disposing the support substrate, it is possible to prevent bending or deformation even if the light control member is thinned from 0.1 mm to 1 mm, for example. By reducing the thickness of the light control member, molding by extrusion molding or the like is further facilitated, and productivity is improved. In addition, it becomes easy to support the light control member that becomes increasingly difficult as the surface light source element becomes larger. The thickness of the support substrate is not particularly limited, but is usually 1 mm to 5 mm, and more preferably in the range of 2 mm to 4 mm, usually in view of weight reduction and strength. The support substrate may be improved in diffusibility by dispersing fine particles that diffuse light inside, embossing on the surface, or applying fine particles. In the case of dispersing fine particles inside or embossing on the surface, it is preferable for production that the base material is a thermoplastic resin, and a suitable material is equivalent to the light control member. Further, the support substrate may be bonded to the light control member, for example, can be bonded with a transparent adhesive or the like, thereby simplifying the assembly process of the surface light source element, and further, the shift of the light control member and wrinkles Occurrence can be prevented.
本発明の光制御部材は、複数の点状光源以外の光源に対しても使用できる。例えば単一の点状光源に対して用いることによって、より広範な範囲において、均一で高い輝度を得ることが可能である。また、本発明の光制御部材が備える複数の凸部は、Ｘ−Ｙ平面に平行な仮想平面内にＸ軸方向に平行且つＹ軸に沿って配置された複数の線状光源、または、Ｙ軸方向に平行且つＸ軸方向に沿って配置された複数の線状光源からの光線方向を制御することが可能であり、高い輝度の均一性が実現できる。これら線状光源として、蛍光灯等や、ＬＥＤ等の点状光源を狭い間隔で直線状に配列して構成した線状光源も用いることができる。 The light control member of the present invention can be used for light sources other than a plurality of point light sources. For example, by using it for a single point light source, it is possible to obtain uniform and high luminance in a wider range. The plurality of convex portions included in the light control member of the present invention are a plurality of linear light sources arranged in a virtual plane parallel to the XY plane, parallel to the X-axis direction and along the Y-axis, or Y It is possible to control the direction of light rays from a plurality of linear light sources arranged in parallel to the axial direction and along the X-axis direction, and high luminance uniformity can be realized. As these linear light sources, it is also possible to use a linear light source configured by linearly arranging point light sources such as fluorescent lamps and LEDs at narrow intervals.
また、本発明の画像表示装置としては、面光源素子上に透過型の表示装置を設けることにより実現され、表示装置としては透過型の液晶パネル等が挙げられる。これにより、表示面の輝度の均一性と、色の均一性とが良く、色再現性に優れる画像表示装置を得ることができる。 The image display device of the present invention is realized by providing a transmissive display device on a surface light source element. Examples of the display device include a transmissive liquid crystal panel. As a result, it is possible to obtain an image display device that has excellent luminance uniformity and color uniformity on the display surface and excellent color reproducibility.
以下、本発明の実施例について説明するが、本発明はこれらの実施例に限定されるものではない。 Examples of the present invention will be described below, but the present invention is not limited to these examples.
図１の略図に示す面光源素子について、輝度の均一性を照明設計解析ソフトウェアＬｉｇｈｔＴｏｏｌｓ（登録商標）を用いて解析した。以下に、解析に用いた条件を記す。 The surface light source element shown in the schematic diagram of FIG. 1 was analyzed for luminance uniformity using illumination design analysis software LightTools (registered trademark). The conditions used for the analysis are described below.
点状光源は、Ｘ＝０、Ｙ＝０の位置に高さが０．５ｍｍ、直径が０．８ｍｍの円柱を１つ配置し、円柱の上面を発光部として、発光の角度特性をランバーシャン分布（Ｌａｍｂｅｒｔｉａｎ）とした。点状光源の下面側には拡散反射をする反射板を配置し、反射板から２５ｍｍの位置に光制御部材を配置した。光制御部材の材質は、一般的なポリスチレン樹脂などの光学樹脂を想定し、屈折率を１．５９とした。 The point light source has one cylinder with a height of 0.5 mm and a diameter of 0.8 mm at the position of X = 0 and Y = 0, and uses the upper surface of the cylinder as a light-emitting part, and the angular characteristics of light emission are Lambertian. Distribution (Lambertian) was used. A reflecting plate that diffusely reflects was disposed on the lower surface side of the point light source, and a light control member was disposed at a position 25 mm from the reflecting plate. The light control member is assumed to be a general optical resin such as polystyrene resin, and the refractive index is set to 1.59.
上記モデルを用いて、１つの点状光源で正面方向からの輝度をシミュレーションで解析し、複数の点状光源を配置した場合の輝度の均一性を、１つの点状光源の結果から算出した。このとき、１つの点状光源でシミュレーションした結果のＸ、Ｙの位置での正面方向への輝度をＬ（Ｘ，Ｙ）とすると、複数の点状光源を配置した場合の輝度Ｌ’（Ｘ，Ｙ）を以下の式から求めた。 Using the above model, the luminance from the front direction with one point light source was analyzed by simulation, and the uniformity of the luminance when a plurality of point light sources were arranged was calculated from the result of one point light source. At this time, assuming that the luminance in the front direction at the X and Y positions as a result of the simulation with one point light source is L (X, Y), the luminance L ′ (X when a plurality of point light sources are arranged , Y) was obtained from the following equation.
複数の点状光源を配置した場合の輝度の分布Ｌ’（Ｘ，Ｙ）について、Ｘ軸方向に沿った点状光源の間隔における最大輝度Ｌｘｍａｘと最小輝度Ｌｘｍｉｎから、最大輝度と最小輝度の比Ｒｘ＝Ｌｘｍｉｎ／Ｌｘｍａｘを、Ｘ軸方向における輝度の均一性の指標として算出した。また、同様に、Ｙ軸方向に沿った点状光源の間隔における最大輝度Ｌｙｍａｘと最小輝度Ｌｙｍｉｎから、最大輝度と最小輝度の比Ｒｙ＝Ｌｙｍｉｎ／Ｌｙｍａｘを、Ｙ軸方向における輝度均一性の指標として算出した。 With respect to the luminance distribution L ′ (X, Y) when a plurality of point light sources are arranged, the maximum luminance and the minimum luminance are calculated from the maximum luminance L xmax and the minimum luminance L xmin in the interval between the point light sources along the X-axis direction. The ratio R x = L xmin / L xmax was calculated as an index of luminance uniformity in the X-axis direction. Similarly, from the maximum luminance L ymax and the minimum luminance L ymin in the interval between the point light sources along the Y-axis direction, the ratio of the maximum luminance to the minimum luminance R y = L ymin / L ymax is determined as the luminance in the Y-axis direction. Calculated as an index of uniformity.
実施例及び比較例で得られたＲｘ、Ｒｙの値と解析の条件を表１に示す。 Table 1 shows the values of R x and R y obtained in Examples and Comparative Examples and the analysis conditions.
実施例１では、光制御部材における凸部を、Ｘ−Ｚ平面に平行な任意の平面における断面形状の輪郭線と、Ｙ−Ｚ平面と平行な任意の平面における断面形状の輪郭線とが多項式からなる場合で、凸部のＸ軸、Ｙ軸、Ｚ軸方向の座標をそれぞれｘ、ｙ、ｚとして、
ｚ（ｘ、ｙ）＝ｆ１（ｘ）＋ｇ１（ｙ）
として、得られる形状についてシミュレーションを行った。複数の点状光源を、Ｄｘ＝２０ｍｍ、Ｄｙ＝２３ｍｍでＸ軸方向、Ｙ軸方向に沿って周期的に配列した。この場合に、Ｘ軸方向、Ｙ軸方向共に光源像が低減され、輝度の均一性が高い品位の良い面光源素子が得られる。
In the first embodiment, the convex portion of the light control member has a polynomial in cross-sectional outline in an arbitrary plane parallel to the XZ plane and a cross-sectional outline in an arbitrary plane parallel to the YZ plane. Where the coordinates of the X-axis, Y-axis, and Z-axis directions of the convex portion are x, y, and z, respectively.
z (x, y) = f 1 (x) + g 1 (y)
As a result, the obtained shape was simulated. A plurality of point light sources were arranged periodically along the X-axis direction and the Y-axis direction with D x = 20 mm and D y = 23 mm. In this case, a light source image is reduced in both the X-axis direction and the Y-axis direction, and a high-quality surface light source element with high luminance uniformity can be obtained.
実施例２では、光制御部材における凸部を、Ｘ−Ｚ平面に平行な品位の平面における断面形状の輪郭線と、Ｙ−Ｚ平面と平行な任意の平面における断面形状の輪郭線とが放物線からなる場合で、凸部のＸ軸、Ｙ軸、Ｚ軸の座標をそれぞれｘ、ｙ、ｚとして、
ｚ（ｘ、ｙ）＝ｆ２（ｘ）＋ｇ２（ｙ）
として、得られる形状についてシミュレーションを行った。複数の点状光源は、Ｄｘ＝２０ｍｍ、Ｄｙ＝３３ｍｍとしてＸ軸方向、Ｙ軸方向に沿って周期的に配列した。この場合において、特にＹ軸方向について光源像を広げることが可能であり、Ｙ軸方向の光源の間隔を広げた場合においても高い輝度の均一性を得ることが可能であり、品位の良い面光源素子が得られる。
In the second embodiment, the convex portion of the light control member has a cross-sectional outline in a plane of quality parallel to the XZ plane and a cross-sectional outline in an arbitrary plane parallel to the YZ plane as a parabola. And the coordinates of the X-axis, Y-axis, and Z-axis of the convex part are x, y, and z, respectively.
z (x, y) = f 2 (x) + g 2 (y)
As a result, the obtained shape was simulated. The plurality of point light sources were arranged periodically along the X-axis direction and the Y-axis direction with D x = 20 mm and D y = 33 mm. In this case, it is possible to widen the light source image especially in the Y-axis direction, and even when the interval between the light sources in the Y-axis direction is widened, high luminance uniformity can be obtained, and a high-quality surface light source An element is obtained.
比較例１、２として、光制御部材における凸部としてマイクロレンズを配列した場合の解析を行った。マイクロレンズは、比較例１では半径０．１５ｍｍの半球を０．３ｍｍ間隔で格子状に配列し、マイクロレンズの高さは０．１５ｍｍである。また、比較例２では半径０．２ｍｍの半球を０．３ｍｍ間隔で格子状に配列し、高さは０．１３ｍｍである。この場合、Ｘ軸方向、Ｙ軸方向における光源像を低減することができず、輝度の均一性が低く、品位が低下する。 As Comparative Examples 1 and 2, analysis was performed when microlenses were arranged as convex portions in the light control member. In the comparative example 1, the microlenses have hemispheres having a radius of 0.15 mm arranged in a lattice pattern at intervals of 0.3 mm, and the height of the microlens is 0.15 mm. In Comparative Example 2, hemispheres having a radius of 0.2 mm are arranged in a lattice pattern at intervals of 0.3 mm, and the height is 0.13 mm. In this case, the light source images in the X-axis direction and the Y-axis direction cannot be reduced, the luminance uniformity is low, and the quality is lowered.
比較例３として、光制御部材における凸部として四角錘を配置した場合の解析を行った。四角錘は、幅０．３ｍｍ、高さ０．１５ｍｍであり、０．３ｍｍ間隔で格子状に配列した。この場合、点状光源の位置で光制御部材に正面方向付近の角度で入射した光は正面方向に透過せず、点状光源の位置で正面方向の輝度が非常に低い。従って、輝度の均一性が低く、品位が悪い。 As Comparative Example 3, an analysis was performed when a quadrangular pyramid was arranged as a convex portion in the light control member. The square pyramids had a width of 0.3 mm and a height of 0.15 mm, and were arranged in a grid at intervals of 0.3 mm. In this case, light incident on the light control member at an angle near the front direction at the position of the point light source does not transmit in the front direction, and the luminance in the front direction at the position of the point light source is very low. Therefore, the luminance uniformity is low and the quality is poor.
１：点状光源
１ａ：赤色のＬＥＤ
１ｂ：青色のＬＥＤ
１ｃ：緑色のＬＥＤ
１ｄ：第４の色のＬＥＤ
１１：複数の点状光源が存在する点状光源の配列の１ユニット
２：光制御部材
２１：光制御部材における、複数の凸部
３：反射板
４１：点状光源から光制御部材にＺ軸から傾いて入射した光
４２：光制御部材から、凸部によってＺ軸方向付近に屈折して出射する光
４３：光制御部材の凸部によって、背面方向に反射する光
５１：Ｘ−Ｚ平面に平行で、ｙ＝ｙ１である平面
５２：Ｘ−Ｙ平面に平行で、ｙ＝ｙ２である平面
６１：５１の平面における、凸部の断面形状の輪郭線
６２：５２の平面における、凸部の断面形状の輪郭線
ａ１：凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の幅
ｂ１：凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の高さ
ａ２：凸部の、Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の幅
ｂ１：凸部の、Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の高さ
θ１：凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度
θ２：凸部の、Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度
ｘ：凸部上における、Ｘ軸方向の座標
ｙ：凸部上における、Ｙ軸方向の座標
ｚ：凸部上における、Ｚ軸方向の座標
ｆ（ｘ）：凸部の、Ｘ−Ｙ平面と平行な平面における断面形状の輪郭線を表す関数
ｇ（ｙ）：凸部の、Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線を表す関数
Ｄｘ：Ｘ軸方向に沿った点状光源の間隔
Ｄｙ：Ｙ軸方向に沿った点状光源の間隔
Ｌ：点状光源が１つの場合の正面方向への輝度の解析結果
Ｌ’：複数の点状光源を配列した場合の正面方向への輝度
Ｌｘｍｉｎ：Ｘ軸方向に沿った点状光源の間隔における最小輝度
Ｌｘｍａｘ：Ｘ軸方向に沿った点状光源の間隔における最大輝度
Ｒｘ：ＬｘｍｉｎとＬｘｍｉｎの比（＝Ｌｘｍｉｎ／Ｌｘｍａｘ）
Ｌｙｍｉｎ：Ｙ軸方向に沿った点状光源の間隔における最小輝度
Ｌｙｍａｘ：Ｙ軸方向に沿った点状光源の間隔における最大輝度
Ｒｙ：ＬｙｍｉｎとＬｙｍｉｎの比（＝Ｌｙｍｉｎ／Ｌｙｍａｘ）
1: Point light source 1a: Red LED
1b: Blue LED
1c: Green LED
1d: LED of the fourth color
11: 1 unit of array of point light sources in which a plurality of point light sources are present 2: light control member 21: a plurality of convex portions in light control member 3: reflector 41: Z axis from point light source to light control member Incident light 42: Light that is refracted in the vicinity of the Z-axis direction by the convex portion from the light control member 43: Light that is reflected in the back direction by the convex portion of the light control member 51: On the XZ plane Parallel plane 52: XY plane 52: parallel to XY plane y: y2 plane 61: 51 plane, convex section cross-sectional contour 62: 52 plane 52: 52 Cross-sectional outline
a 1 : Width of the contour line of the cross-sectional shape in the plane parallel to the XZ plane of the convex part b 1 : Height of the contour line of the cross-sectional shape in the plane parallel to the XZ plane of the convex part a 2 : The width b 1 of the contour line of the cross-sectional shape in the plane parallel to the YZ plane of the convex portion: the height θ 1 of the contour line of the cross-sectional shape in the plane parallel to the YZ plane of the convex portion , The maximum inclination angle θ 2 of the contour line of the cross-sectional shape in the plane parallel to the XZ plane: the maximum inclination angle x of the contour line of the cross-sectional shape in the plane parallel to the YZ plane x: on the convex part , X-axis direction coordinate y: on the convex portion, Y-axis direction coordinate z: on the convex portion, Z-axis direction coordinate f (x): sectional shape of the convex portion in a plane parallel to the XY plane Function g (y) representing the contour line of the projection: Function D representing the contour line of the cross-sectional shape of the convex portion in a plane parallel to the YZ plane x : Distance between point light sources along the X-axis direction D y : Distance between point light sources along the Y-axis direction L: Analysis result of luminance in the front direction when there is one point light source L ′: Plurality Luminance L xmin in the front direction when the point light sources are arranged: Minimum luminance L xmax in the interval between the point light sources along the X-axis direction: Maximum luminance R x in the interval between the point light sources along the X-axis direction: Ratio of L xmin and L xmin (= L xmin / L xmax )
L ymin : Minimum luminance L ymax at the interval between the point light sources along the Y-axis direction: Maximum luminance R y at the interval between the point light sources along the Y-axis direction R y : Ratio of L ymin and L ymin (= L ymin / L ymax )
Claims (7)
少なくとも、
Ｘ−Ｙ平面に平行な発光面と、複数の点状光源と、１枚のシート状、またはフィルム状の光制御部材とを備え、
前記複数の点状光源が、前記Ｘ−Ｙ平面に平行な仮想平面内に配置され、
前記光制御部材が、前記Ｘ−Ｙ平面に平行に、且つ、前記複数の点状光源のＺ軸方向側に配置され、
前記発光面が、前記光制御部材のＺ軸方向側に配置されている面光源素子であって、
前記光制御部材の主に光が出射する面に、複数の凸部を備えており、
前記複数の凸部の、
Ｘ−Ｚ平面と平行な任意の平面における断面形状が一定であり、
且つ、
Ｙ−Ｚ平面と平行な任意の平面における断面形状が一定である
ことを特徴とする面光源素子。 One of the normals of the XY plane parallel to the X axis and the Y axis orthogonal to the X axis is defined as the Z axis direction.
at least,
A light emitting surface parallel to the XY plane, a plurality of point light sources, and a sheet-like or film-like light control member,
The plurality of point light sources are arranged in a virtual plane parallel to the XY plane,
The light control member is arranged in parallel to the XY plane and on the Z-axis direction side of the plurality of point light sources,
The light-emitting surface is a surface light source element disposed on the Z-axis direction side of the light control member,
The light control member has a plurality of convex portions on the surface from which light is emitted mainly,
The plurality of convex portions,
The cross-sectional shape in an arbitrary plane parallel to the XZ plane is constant,
and,
A surface light source element having a constant cross-sectional shape in an arbitrary plane parallel to the YZ plane.
前記複数の点状光源が、Ｘ軸方向に周期的に配列され、且つＹ軸方向に周期的に配列されていることを特徴とする面光源素子。 The surface light source element according to claim 1,
The surface light source element, wherein the plurality of point light sources are periodically arranged in the X-axis direction and periodically arranged in the Y-axis direction.
前記複数の凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線が、楕円または放物線または多項式からなる曲線の一部からなり、
且つ、
Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線が、楕円または放物線または多項式からなる曲線の一部からなることを特徴とする面光源素子。 The surface light source element according to claim 1 or 2,
The contour line of the cross-sectional shape in a plane parallel to the XZ plane of the plurality of convex portions consists of a part of a curve made of an ellipse, a parabola, or a polynomial,
and,
A surface light source element, wherein a contour line of a cross-sectional shape in a plane parallel to the YZ plane is formed of a part of a curve made of an ellipse, a parabola, or a polynomial.
前記複数の凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の幅ａ１と、輪郭線の高さｂ１の比ｂ１／ａ１が０．２８〜０．６５であり、
且つ、
Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の幅ａ２と、輪郭線の高さｂ２の比ｂ２／ａ２が０．２８〜０．６５であることを特徴とする面光源素子。 The surface light source element according to claim 1,
The ratio b 1 / a 1 of the contour line width a 1 and the contour line height b 1 in a plane parallel to the XZ plane of the plurality of convex portions is 0.28 to 0.65. Yes,
and,
A surface having a ratio b 2 / a 2 of a contour line width a 2 and a contour line height b 2 in a plane parallel to the YZ plane is 0.28 to 0.65. Light source element.
前記複数の凸部の、Ｘ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度θ１が、５０度〜８２度であり、
且つ、
Ｙ−Ｚ平面と平行な平面における断面形状の輪郭線の最大傾斜角度θ２が、５０度〜８２度であることを特徴とする面光源素子。 The surface light source element according to any one of claims 1 to 4,
The maximum inclination angle θ1 of the contour line of the cross-sectional shape in a plane parallel to the XZ plane of the plurality of convex portions is 50 degrees to 82 degrees,
and,
A surface light source element, wherein the maximum inclination angle θ2 of the contour line of the cross-sectional shape in a plane parallel to the YZ plane is 50 degrees to 82 degrees.
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| WO2012073543A1 (en) | 2010-12-01 | 2012-06-07 | シャープ株式会社 | Planar light-emitting illumination device |
| JP2019075280A (en) * | 2017-10-16 | 2019-05-16 | シチズン電子株式会社 | Planar light unit |
| WO2021170528A1 (en) * | 2020-02-24 | 2021-09-02 | Signify Holding B.V. | A light emitting device for use in a light emitting panel |
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| JP2008129604A (en) * | 2006-11-20 | 2008-06-05 | Kofukin Seimitsu Kogyo (Shenzhen) Yugenkoshi | Optical plate and its manufacturing method |
| JP2008527627A (en) * | 2004-12-30 | 2008-07-24 | スリーエム イノベイティブ プロパティズ カンパニー | Optical film having a surface with a rounded structure |
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| JP2008527627A (en) * | 2004-12-30 | 2008-07-24 | スリーエム イノベイティブ プロパティズ カンパニー | Optical film having a surface with a rounded structure |
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| JP5199780B2 (en) | 2013-05-15 |
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