JPH063667A - Backlight - Google Patents
BacklightInfo
- Publication number
- JPH063667A JPH063667A JP3233799A JP23379991A JPH063667A JP H063667 A JPH063667 A JP H063667A JP 3233799 A JP3233799 A JP 3233799A JP 23379991 A JP23379991 A JP 23379991A JP H063667 A JPH063667 A JP H063667A
- Authority
- JP
- Japan
- Prior art keywords
- light
- sheet
- backlight
- degrees
- prism
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Liquid Crystal (AREA)
- Planar Illumination Modules (AREA)
- Light Guides In General And Applications Therefor (AREA)
- Optical Elements Other Than Lenses (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、透過型又は、半透過型
パネルを背面より照射するパネル用バックライトに関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight for a panel which illuminates a transmissive or semi-transmissive panel from the back side.
【０００２】[0002]
【従来の技術】近時、ラップトップ型又は、ブック型の
ワ−ドプロセッサ−やコンピュ−タ等の表示装置とし
て、薄型でしかも見易いバックライト機構を有する液晶
表示装置が用いられている。このようなバックライトに
は、図１に示すように透光性の導光板の一端部に蛍光管
のような線状光源を併設し、導光板の一方の面にこの導
光板材料よりも屈折率が大きい光拡散物質を部分的に被
覆し、その面を反射板で覆い、もう一方の面に光拡散板
を配置したエッジライト方式、図２に示すように蛍光管
のような線状光源の背面を反射板で覆い、その上面に光
拡散板を配置した直下ライト方式、図３に示すように直
接面発光させる平面蛍光ランプなどがある。2. Description of the Related Art Recently, a liquid crystal display device having a backlight mechanism which is thin and easy to see has been used as a display device for a laptop or book type word processor, a computer or the like. In such a backlight, as shown in FIG. 1, a linear light source such as a fluorescent tube is provided at one end of a light-transmitting light guide plate, and one surface of the light guide plate is refracted more than the light guide plate material. An edge light system in which a light diffusing substance having a high rate is partially covered, a surface thereof is covered with a reflecting plate, and a light diffusing plate is arranged on the other surface, and a linear light source such as a fluorescent tube as shown in FIG. There is a direct lighting system in which the back surface of the above is covered with a reflecting plate and a light diffusing plate is arranged on the upper surface thereof, and a flat fluorescent lamp for direct surface emission as shown in FIG.
【０００３】特に近時、バックライトがバッテリー駆動
されるようになり消費電力−輝度変換効率のより一層の
向上が望まれおり、エッジライト方式および直下ライト
方式に於いては、反射器に反射率の高い材料を使用した
り、反射器の形状を光の利用効率が高くなるように最適
化したり、光拡散板の透過率を改善することが提案され
ている。また、平面蛍光ランプに於いては、電極の材質
と構造、封入ガスの種類とガス圧、蛍光膜の膜厚を最適
化することが提案されている。Particularly, in recent years, since the backlight is driven by a battery, further improvement of power consumption-luminance conversion efficiency is desired. In the edge light system and the direct light system, the reflectivity of the reflector is increased. It has been proposed to use a high material, optimize the shape of the reflector so as to improve the light utilization efficiency, and improve the transmittance of the light diffusion plate. Further, in the flat fluorescent lamp, it has been proposed to optimize the material and structure of the electrode, the type and gas pressure of the enclosed gas, and the film thickness of the fluorescent film.
【０００４】しかし、前記したいづれの方法において
も、消費電力−輝度変換効率は向上するものの未だ充分
でなく、更により一層の向上が望まれている。However, although the power consumption-luminance conversion efficiency is improved by any of the above-mentioned methods, it is still insufficient, and further improvement is desired.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、消費
電力−輝度変換効率が高く、かつ高輝度が得られるバッ
クライトを提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight which has high power consumption-luminance conversion efficiency and high luminance.
【０００６】[0006]
【課題を解決するための手段】本発明者等は、上述の点
につき種々の検討を行った結果、面状発光体に於いて、
出光面側に、同一面に、ある形状の突起を微細な間隔で
多数有する透光性材料からなるシ−トを、前記突起面が
外側になるように配すると、バックライトの配光特性が
変化し、出光面に降ろした法線方向近傍に対する光の指
向性がより強くなり、実質的に出光面に降ろした法線方
向近傍に対しては前記した消費電力−輝度変換効率の高
いバックライトとなることを見出した。Means for Solving the Problems As a result of various investigations on the above points, the present inventors
When a sheet made of a translucent material having a large number of protrusions of a certain shape on the same surface on the same side as the light emitting surface is arranged with the protrusion surface facing outward, the light distribution characteristics of the backlight are improved. The directivity of the light that has changed and becomes closer to the normal direction dropped onto the light emitting surface becomes stronger, and the backlight having high power consumption-luminance conversion efficiency described above substantially near the normal direction dropped onto the light emitting surface. I found that.
【０００７】即ち本発明は、頂角が実質的に同じ形状の
部分を持つプリズムまたは円錐状の突起を、微細な間隔
で同一面に多数有する透光性材料からなるシ−トを、突
起面が外側になるように、面状発光体の出光面側に１枚
以上配置したパネル用バックライトに関するものであ
る。That is, according to the present invention, a sheet made of a translucent material having a large number of prisms or conical projections having portions with substantially the same apex angle on the same surface at fine intervals is used. The present invention relates to a panel backlight in which one or more sheets are arranged on the light emitting surface side of the planar light-emitting body so that the light source is on the outside.
【０００８】次に本発明を図面に基づいて詳述する。図
４は、導光板の一端部に光源を持つエッジライト方式の
一実施態様の斜視図であり、図５は断面図である。図中
１は光源である。２は透光性材料からなるシ−トで、出
光面が、頂角が実質的に同じ形状の部分を持つ突起を微
細な間隔で多数有するもので、このような配置とするこ
とにより、面状発光体より出光した光の指向性を変化さ
せ、出光面に降ろした法線方向近傍に対する指向性をよ
り強くさせるものである。本発明ではこのシ−トを１枚
又は複数枚用いる。Next, the present invention will be described in detail with reference to the drawings. FIG. 4 is a perspective view of an embodiment of an edge light system having a light source at one end of a light guide plate, and FIG. 5 is a sectional view. In the figure, 1 is a light source. 2 is a sheet made of a translucent material, and the light emitting surface has a large number of projections having portions with substantially the same apex angle at minute intervals. The directivity of the light emitted from the light-emitting body is changed, and the directivity in the vicinity of the normal direction dropped on the light emitting surface is further strengthened. In the present invention, one or more sheets are used.
【０００９】本発明は、前記したように、バックライト
の出光面側に、ある条件を満足する形状を持つ透光性材
料からなるシ−トを配置することが特徴である。As described above, the present invention is characterized in that a sheet made of a translucent material having a shape satisfying a certain condition is arranged on the light emitting surface side of the backlight.
【００１０】本発明における前記条件を更に詳述する
と、前記したシ−ト（図中２）は透光性材料からなるも
のであれば特に限定されないが、例えばアクリル、ポリ
カ−ボネイト、ポリ塩化ビニル、ポリスチレン、ポリア
ミド、ポリエステル、ポリエチレン、ポリプロピレン、
ガラス等である。The above-mentioned conditions in the present invention will be described in more detail. The above-mentioned sheet (2 in the figure) is not particularly limited as long as it is made of a translucent material. For example, acrylic, polycarbonate, polyvinyl chloride. , Polystyrene, polyamide, polyester, polyethylene, polypropylene,
For example, glass.
【００１１】本発明で用いるシ−トの、出光面側に形成
する突起の形状は、光学的平面を２つ以上持ついわゆる
プリズム状のもので、３角錐、４角錐などの多角錐、ま
たは円錐である。シートに形成するこれら突起物は、そ
の頂角が実質的に同じ形状の部分を持つもので、このこ
とは、同一の条件で得た頂点を含む裁断面の頂角が実質
的に同じ角度を持つことを意味する。The shape of the projection formed on the light output surface side of the sheet used in the present invention is a so-called prism shape having two or more optical planes, such as a three-sided pyramid or a four-sided pyramid, or a cone. Is. These protrusions formed on the sheet have portions with substantially the same apex angle, which means that the apex angles of the cutting planes including the vertices obtained under the same conditions have substantially the same angle. Means to have.
【００１２】本発明に於いては、前記したシ−トの突起
物の頂角は７０〜１５０度であることが好ましい。前記
頂角のより好ましい角度範囲は、用いるシ−トの材料の
屈折率および用いる面状発光体の配光特性に依存する。
例えば、屈折率の大なる材料（ポリカ−ボネイト、屈折
率ｎ＝１．５９）を用いた場合は、比較的大きい頂角
（例えば１２０度）を持つものが好ましい。又、配光特
性、例えば面状発光体から出光する光が出光面に降ろし
た法線方向から４５度以内に実質的に集中している場合
は、頂角が１００度〜１４０度のものが好ましい。頂角
が１５０度を越えると本発明の効果は減少する。In the present invention, the apex angle of the above-mentioned sheet projections is preferably 70 to 150 degrees. The more preferable range of the apex angle depends on the refractive index of the sheet material used and the light distribution characteristics of the planar light emitter used.
For example, when a material having a large refractive index (polycarbonate, refractive index n = 1.59) is used, a material having a relatively large apex angle (for example, 120 degrees) is preferable. Further, when the light distribution characteristics, for example, the light emitted from the planar light emitter is substantially concentrated within 45 degrees from the direction normal to the light emitting surface, the apex angle of 100 degrees to 140 degrees is preferable. preferable. If the apex angle exceeds 150 degrees, the effect of the present invention decreases.
【００１３】又、前記したシ−トの突起物の、頂点から
のそれぞれの斜辺の長さが実質的に等しいものを用いる
ことが、本発明の効果を向上させる上で特に好ましい。
又、シートに形成した多数の突起物の分布状態は、表面
から出光される光によって突起物間の間隔が視認される
ことを困難とする上で、隣り合った突起物の頂点と頂点
の間隔は１０〜１０００μｍであることが好ましい。同
一面に形成する突起物は、より効果的には同一形状の突
起物が良い。Further, it is particularly preferable to use the above-mentioned sheet projections in which the lengths of the respective hypotenuses from the apex are substantially equal in order to improve the effect of the present invention.
In addition, the distribution of many protrusions formed on the sheet makes it difficult for the light emitted from the surface to visually recognize the distance between the protrusions. Is preferably 10 to 1000 μm. The protrusions formed on the same surface are more effectively the same in shape.
【００１４】本発明で用いるシートを成形する方法は特
に限定されるものではなく、例えば熱プレスによる金型
成型加工、エンボス加工、化学処理等の方法で実質的に
同形の突起物を微細な間隔で多数有するように成形する
ことが可能な方法であれば良い。The method for molding the sheet used in the present invention is not particularly limited, and for example, projections of substantially the same shape can be formed at fine intervals by a method such as die molding by hot pressing, embossing, or chemical treatment. Any method can be used as long as it can be molded so as to have a large number.
【００１５】液晶ディスプレイは、その表示面に降ろし
た法線方向から視認する角度が大きくなる程コントラス
トが低くなるため、実用上、前記法線方向近傍での輝度
が重視される。更に、ビュ−ファインダ−に至ってはそ
の表示面に降ろした法線方向からしか見ないため、実用
上、前記法線方向近傍での輝度が重視される。In a liquid crystal display, the contrast becomes lower as the angle viewed from the normal direction lowered on the display surface becomes lower. Therefore, practically, the brightness in the vicinity of the normal direction is important. Further, since the viewfinder can be seen only from the normal direction dropped on the display surface, practically, the brightness in the vicinity of the normal direction is important.
【００１６】本発明で、前記したように、出光面側が微
細な間隔で多数の突起を有するシ−トを、面状発光体の
出光面に配すると、光の指向性が現われる。即ち、実質
的に出光面に降ろした法線方向でその面より出光した光
の輝度を測定した場合、前記シ−トを配さない場合に比
較して、輝度が増加されること、前記出光面に降ろした
法線に対してある角度、例えば４０度の方向から同様に
測定した輝度が、実質的に法線方向で測定した時の輝度
よりその減少割合が大となる（例えば、法線方向で測定
した時の輝度のほぼ５０％まで減少する）こと等から、
前記した光の指向性が現れていることが判る。尚、ここ
で用いる輝度計は通常一般に用いられる市販の輝度計で
ある。In the present invention, as described above, when a sheet having a large number of protrusions on the light emitting surface side at fine intervals is arranged on the light emitting surface of the planar light emitter, the directivity of light appears. That is, when the brightness of the light emitted from the surface is measured substantially in the normal direction dropped to the light emitting surface, the brightness is increased as compared with the case where the sheet is not arranged, The luminance measured in the same manner from a direction at a certain angle, for example, 40 degrees with respect to the normal drawn to the surface, has a larger reduction rate than the luminance measured substantially in the normal direction (for example, the normal). Direction, it decreases to almost 50% of the brightness).
It can be seen that the directivity of light described above appears. The luminance meter used here is a commonly used commercially available luminance meter.
【００１７】次に、本発明における作用を図面に基づい
て更に詳述する。図６は本発明で、プリズム状の突起を
持つシートを用いた場合の、シ−トの任意のプリズムの
断面に任意の点から入射する光線を光線追跡した一例の
図である。プリズムの頂角を２α（度）とし、透光性材
料からなるシ−トの屈折率をｎ、空気の屈折率を１とす
ると、臨界角θｃ（度）は θｃ＝ｓｉｎ−１（１／ｎ） １）光線が角度θ１（度）で入射し角度θ６（度）で出
射する場合（図６（ａ）） ｓｉｎθ１＝ｎ×ｓｉｎ
θ２ θ３＝９０°−α−θ２ ｎ×ｓｉｎθ３＝ｓｉｎθ４ （ただしθ３≦θｃのと
き） θ５＝９０°−α−θ４ θ６＝θ５ ２）光線が角度θ１（度）で入射し角度θ８（度）で出
射する場合（図６（ｂ）） ｓｉｎθ１＝ｎ×ｓｉｎ
θ２ θ３＝９０°−α−θ２ θ４＝θ３ （ただしθ３＞θｃのとき） θ５＝２α−θ４ ｎ×ｓｉｎθ５＝ｓｉｎθ６ （ただしθ５≦θｃのと
き） θ７＝９０°−α−θ６ θ８＝−θ７ このような計算を行うことによって、透光性材料からな
るシ−トに用いる材料の屈折率、プリズムの頂角がわか
れば、透光性材料からなるシ−トのプリズムと空気の界
面での屈折と反射を臨界角θｃで場合分けし、面状発光
体の出光面から出光する光線の透光性材料からなるシ−
トへの入射角から出射角を求めることが出来る。尚、図
６には示さなかったが、前記条件によっては、入射光線
はプリズム内部を２回以上反射する場合もあるし、面状
発光体の出光面に戻る場合もある。Next, the operation of the present invention will be described in more detail with reference to the drawings. FIG. 6 is a diagram showing an example of ray tracing of a ray incident from an arbitrary point on the cross section of an arbitrary prism of the sheet in the case of using a sheet having prism-shaped protrusions in the present invention. If the apex angle of the prism is 2α (degrees), the refractive index of the sheet made of a translucent material is n, and the refractive index of air is 1, the critical angle θc (degrees) is θc = sin −1 (1 / n) 1) A light beam enters at an angle θ 1 (degrees) and exits at an angle θ 6 (degrees) (FIG. 6A) sin θ 1 = n × sin
θ 2 θ 3 = 90 ° -α-θ 2 n × sin θ 3 = sin θ 4 (when θ 3 ≦ θc) θ 5 = 90 ° -α-θ 4 θ 6 = θ 5 2) Ray angle θ 1 When incident at (degrees) and emitted at an angle θ 8 (degrees) (FIG. 6B) sin θ 1 = n × sin
θ 2 θ 3 = 90 ° −α−θ 2 θ 4 = θ 3 (where θ 3 > θc) θ 5 = 2α−θ 4 n × sin θ 5 = sin θ 6 (where θ 5 ≦ θc) θ 7 = 90 ° -α-θ 6 θ 8 = -θ 7 By performing such a calculation, if the refractive index of the material used for the sheet made of a translucent material and the apex angle of the prism are known, the translucent light is obtained. Refraction and reflection at the interface between the prism of a sheet made of a transparent material and air are classified by the critical angle θc, and a sheet made of a translucent material of a light beam emitted from the light emitting surface of the planar light-emitting body.
The output angle can be obtained from the incident angle to the lens. Although not shown in FIG. 6, depending on the above conditions, the incident light beam may be reflected twice or more inside the prism, or may be returned to the light emitting surface of the planar light-emitting body.
【００１８】例えば、図７に示したように前記シ−トを
ポリカ−ボネイト（屈折率ｎ＝１．５９）で作りプリズ
ムの頂角を９０度にした場合に於いては、入射角０度で
前記シ−トに入射した光線はプリズム内部で全反射し、
面状発光体へ戻される。面状発光体へ戻された光線は面
状発光体内部で一部は吸収され、一部は反射し再び面状
発光体の発光面より出光する。従って、この様に面状発
光体から出光した光が前記シ−トのプリズム内部で全反
射して再び面状発光体へ戻される場合には、面状発光体
内部での光の吸収が少ない程、また面状発光体内部での
光の反射率が高い程すなわち面状発光体の発光面以外の
面が反射率の高い反射板で覆われている程、効率の良い
バックライトになる。また、入射角３０度で前記シ−ト
に入射した光線は出射角０．５度で前記シ−トより出光
し、入射角６０度で前記シ−トに入射した光線は出射角
２５．７度で前記シ−トより出光する。そして、この場
合の面状発光体の出光面から出光する光は実質的に前記
出光面に降ろした法線方向からの角度がほぼ４０度以内
に最も集中し、その結果、前記法線方向から測定した輝
度が、前記シ−トを配さない場合に比較して増加する。For example, when the sheet is made of polycarbonate (refractive index n = 1.59) as shown in FIG. 7 and the apex angle of the prism is 90 °, the incident angle is 0 °. Then, the light rays incident on the sheet are totally reflected inside the prism,
It is returned to the planar light emitter. The light beam returned to the planar light-emitting body is partially absorbed inside the planar light-emitting body, partially reflected, and emitted again from the light emitting surface of the planar light-emitting body. Therefore, when the light emitted from the planar light-emitting body is totally reflected inside the prism of the sheet and returned to the planar light-emitting body in this way, the light absorption inside the planar light-emitting body is small. The higher the reflectance of light inside the planar light-emitting body, that is, the surface other than the light-emitting surface of the planar light-emitting body is covered with the reflective plate having high reflectance, the more efficient the backlight becomes. Further, a light ray incident on the sheet at an incident angle of 30 degrees is emitted from the sheet at an emission angle of 0.5 degrees, and a light ray incident on the sheet at an incident angle of 60 degrees is an emission angle of 25.7. Light is emitted from the sheet at a certain degree. Then, in this case, the light emitted from the light emitting surface of the planar light-emitting body is substantially concentrated most within an angle of about 40 degrees from the normal direction dropped onto the light emitting surface, and as a result, from the normal direction. The measured brightness increases as compared to the case where the sheet is not provided.
【００１９】同様に、図８に示したように前記シ−トを
ポリカ−ボネイトで作り、プリズムの頂角を１２０度に
した場合に於いては、入射角０度で前記シ−トに入射し
た光線は出射角２２．７度で前記シ−トより出光し、入
射角３０度で前記シ−トに入射した光線は出射角１１．
２度で前記シ−トより出光し、入射角６０度で前記シ−
トに入射した光線は出射角３４．８度で前記シ−トより
出光する。そして、この場合の面状発光体の出光面から
出光する光は実質的に前記出光面に降ろした法線方向か
らの角度がほぼ４４度以内に最も集中し、その結果、前
記法線方向から測定した輝度が、前記シ−トを配さない
場合に比較して増加する。Similarly, in the case where the sheet is made of polycarbonate as shown in FIG. 8 and the apex angle of the prism is 120 degrees, the sheet is incident on the sheet at an incident angle of 0 degree. The emitted light is emitted from the sheet at an emission angle of 22.7 degrees, and the light ray incident on the sheet at an incident angle of 30 degrees is emitted at an emission angle of 11.
Light is emitted from the sheet at 2 degrees, and the sheet is emitted at an incident angle of 60 degrees.
The light ray incident on the sheet exits from the sheet at an exit angle of 34.8 degrees. Then, the light emitted from the light emitting surface of the planar light emitting body in this case is substantially concentrated most within an angle of about 44 degrees from the normal direction dropped onto the light emitting surface, and as a result, from the normal direction. The measured brightness increases as compared to the case where the sheet is not provided.
【００２０】この様に、前記シ−トのプリズムの頂角を
コントロ−ルすることによって、面状発光体の出光面か
ら出光する光の指向性を制御することが出来る。As described above, by controlling the apex angle of the prism of the sheet, it is possible to control the directivity of the light emitted from the light emitting surface of the planar light emitting body.
【００２１】[0021]
【発明の効果】本発明は比較的小型で、充分な輝度を得
られ、出光面に降ろした法線方向に対しては消費電力−
輝度変換効率が大なバックライトとして使用できる。EFFECTS OF THE INVENTION The present invention is comparatively small in size, can obtain sufficient brightness, and consumes less power in the direction normal to the light exit surface.
It can be used as a backlight with high luminance conversion efficiency.
【００２２】[0022]
【実施例】次に比較例及び実施例で本発明を更に詳述す
る。図４に示すような厚さ２．０ｍｍの長方形導光板
（２２５ｍｍ×１２７ｍｍ）の短手の端部に、直径４．
８ｍｍの太さの冷陰極蛍光管（ハリソン電機株式会社製
ノ−マル管）を配置し、導光板に接する部分に２ｍｍの
スリットを持つ筒型アルミ反射器の内面に光拡散フィル
ムをラミネ−トしたもので覆い、スリットから出光した
光が導光板の端部から導光板に入光するように配置し
た。一方、導光板面上に被覆する光拡散物質（チタンホ
ワイトを含む塗料）は、円形のドットパタ−ンを１．２
ｍｍピッチでスクリ−ン印刷したものであり下記の条件
で作成して用いた。光拡散物質の被覆率が、最小の地点
（冷陰極蛍光管側）で６％、最大の地点で８０％、その
中間ではこれらの比率を順次増加した値となるように作
図した。EXAMPLES Next, the present invention will be described in more detail with reference to Comparative Examples and Examples. A rectangular light guide plate (225 mm × 127 mm) having a thickness of 2.0 mm as shown in FIG.
A cold-cathode fluorescent tube (Normal tube manufactured by Harrison Electric Co., Ltd.) having a thickness of 8 mm is arranged, and a light diffusion film is laminated on the inner surface of a cylindrical aluminum reflector having a 2 mm slit in a portion in contact with the light guide plate. It was arranged so that the light emitted from the slit would enter the light guide plate from the end portion of the light guide plate. On the other hand, the light diffusing substance (paint containing titanium white) coated on the surface of the light guide plate has a circular dot pattern of 1.2.
It was screen-printed at a mm pitch and was prepared and used under the following conditions. The plots were made so that the coverage of the light diffusing substance was 6% at the minimum point (cold cathode fluorescent tube side), 80% at the maximum point, and these ratios were sequentially increased in the middle.
【００２３】さらに、導光板の出光面側に光拡散フィル
ム（辻本電機製作所Ｄ−２０４）を１枚配置した。冷陰
極管に、インバ−タより３０ＫＨｚの交番電圧をかけて
一定電流で駆動させたときの面輝度を、輝度計（トプコ
ンＢＭ−７）により視野角２度、出光面に降ろした法線
方向に対して、出光面から輝度計までの距離４０ｃｍで
測定したところ１９２ｃｄ／ｍ２であった（比較例
１）。Further, one light diffusion film (Tsujimoto Denki Seisakusho D-204) was arranged on the light emitting surface side of the light guide plate. The surface brightness when an alternating voltage of 30 KHz is applied from the inverter to the cold-cathode tube and driven with a constant current, the viewing angle is 2 degrees by a brightness meter (Topcon BM-7), and the normal direction is lowered to the light emitting surface. On the other hand, when measured at a distance of 40 cm from the light emitting surface to the luminance meter, it was 192 cd / m 2 (Comparative Example 1).
【００２４】前記光拡散フィルムの上にポリカ−ボネイ
トからなる頂角が９０度の４角錐のプリズム状の突起
を、突起の隣り合った頂点と頂点との間隔が４００μｍ
の間隔になるように加工したシ−トを突起面が外側にな
るように面状発光体の出光面側に１枚配置した以外は比
較例１と同一の装置、条件、で操作し、測定した輝度は
３２２ｃｄ／ｍ２であった（実施例１）。更にプリズム
状の突起の頂角を７０度にした以外は実施例１と同一の
装置、条件、で操作し、測定した輝度は２６３ｃｄ／ｍ
２であった（実施例２）。更にプリズム状の突起の頂角
を１２０度にした以外は実施例１と同一の装置、条件、
で操作し、測定した輝度は３５９ｃｄ／ｍ２であった
（実施例３）。On the light-diffusing film, prism-shaped projections made of polycarbonate and having a vertex angle of 90 degrees and having a four-sided pyramid shape, and the distance between adjacent peaks of the projections is 400 μm.
Measurement was performed by operating with the same apparatus and conditions as in Comparative Example 1 except that one sheet, which was processed so as to have an interval of, was arranged on the light emitting surface side of the planar light-emitting body with the protruding surface facing outward. The luminance thus obtained was 322 cd / m 2 (Example 1). Further, the brightness was 263 cd / m as measured by operating with the same apparatus and conditions as in Example 1 except that the prism-shaped protrusion had an apex angle of 70 degrees.
2 (Example 2). Further, the same apparatus and conditions as in Example 1 except that the apex angle of the prism-shaped protrusions was set to 120 degrees,
The measured luminance was 359 cd / m 2 (Example 3).
【００２５】次に、バックライトの配光特性を調べるた
めに、比較例１、実施例１、実施例２、について、冷陰
極管に、インバ−タより３０ＫＨｚの交番電圧をかけて
一定電流で駆動させたときの面輝度を、輝度計（トプコ
ンＢＭ−７）により視野角２度で、図９に示すように出
光面に降ろした法線方向に対しての角度を０度から７０
度まで変化させ、出光面から輝度計までの距離４０cmで
測定したときの輝度の値を図１０に示した。この図か
ら、本発明のバックライトを用いると輝度が増加し、光
の指向性が顕著であることが判る。Next, in order to examine the light distribution characteristics of the backlight, in Comparative Example 1, Example 1 and Example 2, an alternating voltage of 30 KHz was applied from the inverter to the cold cathode tube at a constant current. With respect to the surface luminance when driven, a luminance meter (Topcon BM-7) has a viewing angle of 2 degrees, and an angle with respect to the normal direction dropped to the light emitting surface from 0 degree to 70 degrees as shown in FIG.
The value of the luminance when measured at a distance of 40 cm from the light emitting surface to the luminance meter is shown in FIG. From this figure, it can be seen that when the backlight of the present invention is used, the brightness is increased and the directivity of light is remarkable.
【００２６】次に、厚さ８．０ｍｍの長方形導光板（２
５５ｍｍ×１５７ｍｍ）の長手の両方の端部に、直径
４．１ｍｍの太さの冷陰極蛍光管（ハリソン電機株式会
社製ノ−マル管）をそれぞれの端部に２本ずつ配置し、
導光板に接する部分に８ｍｍのスリットを持つＡｇフィ
ルムで覆い、スリットから出光した光が導光板の端部か
ら導光板に入光するように配置した。一方、導光板面上
に被覆する光拡散物質（チタンホワイトを含む塗料）
は、円形のドットパタ−ンを１．０ｍｍピッチでスクリ
−ン印刷したものであり下記の条件で作成して用いた。
光拡散物質の被覆率が、最小の地点（冷陰極蛍光管側）
で４０％、最大の地点で９８％、その中間ではこれらの
比率を順次増加した値となるように作図した。そして、
出光面以外は反射板で覆った。Next, a rectangular light guide plate (2
55 mm x 157 mm) at both longitudinal ends, two cold cathode fluorescent tubes having a diameter of 4.1 mm (Nomar tube manufactured by Harrison Electric Co., Ltd.) are arranged at each end.
The portion in contact with the light guide plate was covered with an Ag film having a slit of 8 mm, and the light emitted from the slit was arranged so as to enter the light guide plate from the end portion of the light guide plate. On the other hand, a light diffusing substance (paint containing titanium white) coated on the surface of the light guide plate.
Is a circular dot pattern screen-printed at a pitch of 1.0 mm and was prepared and used under the following conditions.
The point where the light diffusing substance coverage is the minimum (cold cathode fluorescent tube side)
The plot was made so that the ratio was 40% at the maximum, 98% at the maximum point, and these ratios were gradually increased in the middle. And
The parts other than the light emitting surface were covered with a reflector.
【００２７】さらに、導光板の出光面側に前記光拡散フ
ィルムを１枚配置した。冷陰極管に、インバ−タより３
０ＫＨｚの交番電圧をかけて一定電流で駆動させたとき
の面輝度を、輝度計（トプコンＢＭ−７）により視野角
２度、出光面に降ろした法線方向に対して、出光面から
輝度計までの距離４０ｃｍで測定したところ１７００ｃ
ｄ／ｍ２であった（比較例２）。Further, one sheet of the light diffusion film is arranged on the light emitting surface side of the light guide plate. In the cold cathode tube, 3 from the inverter
As for the surface brightness when driven with a constant current by applying an alternating voltage of 0 KHz, the brightness meter from the light emitting surface to the normal direction dropped to the light emitting surface with a viewing angle of 2 degrees by the brightness meter (Topcon BM-7). Measured at a distance of 40 cm to 1700c
It was d / m 2 (Comparative Example 2).
【００２８】前記光拡散フィルムの上にポリカ−ボネイ
トからなるプリズム状の突起の頂角が９０度の前記シ−
トを突起面が外側になるように面状発光体の出光面側に
１枚配置した以外は比較例２と同一の装置、条件、で操
作し、測定した輝度は２９７０ｃｄ／ｍ２であった（実
施例４）。On the light-diffusing film, the prism-shaped projections made of polycarbonate have a vertex angle of 90 degrees.
The brightness was 2970 cd / m 2 as measured by operating under the same conditions and conditions as in Comparative Example 2 except that one sheet was arranged on the light emitting surface side of the planar light-emitting body so that the protruding surface was on the outside. (Example 4).
【００２９】次に、厚さ３．０ｍｍの長方形導光板（８
７ｍｍ×７５ｍｍ）の長手の両方の端部に、直径４．１
ｍｍの太さの冷陰極蛍光管（ハリソン電機株式会社製ノ
−マル管）をそれぞれの端部に１本ずつ配置し、導光板
に接する部分に３ｍｍのスリットを持つＡｇフィルムで
覆い、スリットから出光した光が導光板の端部から導光
板に入光するように配置した。一方、導光板面上に被覆
する光拡散物質（チタンホワイトを含む塗料）は、円形
のドットパタ−ンを１．０ｍｍピッチでスクリ−ン印刷
したものであり下記の条件で作成して用いた。光拡散物
質の被覆率が、最小の地点（冷陰極蛍光管側）で２０
％、最大の地点で９８％、その中間ではこれらの比率を
順次増加した値となるように作図した。そして、出光面
以外は反射板で覆った。Next, a rectangular light guide plate (8
7 mm x 75 mm) with a diameter of 4.1 on both ends.
mm cold cathode fluorescent tubes (Normal tube manufactured by Harrison Electric Co., Ltd.) are arranged one at each end, and covered with an Ag film having a 3 mm slit in the portion in contact with the light guide plate. It was arranged so that the emitted light enters the light guide plate from the end portion of the light guide plate. On the other hand, the light diffusing substance (coating containing titanium white) coated on the surface of the light guide plate was a circular dot pattern screen-printed at a pitch of 1.0 mm, and was prepared and used under the following conditions. The light diffusing substance coverage is 20 at the minimum point (cold cathode fluorescent tube side).
%, 98% at the maximum point, and in the middle, these ratios were sequentially increased. Then, the portions other than the light emitting surface were covered with a reflector.
【００３０】さらに、導光板の出光面側に前記光拡散フ
ィルムを１枚配置した。冷陰極管に、インバ−タより３
０ＫＨｚの交番電圧をかけて一定電流で駆動させたとき
の面輝度を、輝度計（トプコンＢＭ−７）により視野角
２度、出光面に降ろした法線方向に対して、出光面から
輝度計までの距離４０ｃｍで測定したところ３８４０ｃ
ｄ／ｍ２であった（比較例３）。Further, one sheet of the light diffusion film is arranged on the light emitting surface side of the light guide plate. In the cold cathode tube, 3 from the inverter
As for the surface luminance when driven with a constant current by applying an alternating voltage of 0 KHz, a luminance meter (Topcon BM-7) was used to measure the viewing angle 2 degrees and the luminance meter from the light emitting surface to the normal direction lowered to the light emitting surface. Measured at a distance of 40 cm to 3840c
It was d / m 2 (Comparative Example 3).
【００３１】前記光拡散フィルムの上にポリカ−ボネイ
トからなるプリズム状の突起の頂角が９０度の前記シ−
トを突起面が外側になるように面状発光体の出光面側に
１枚配置した以外は比較例３と同一の装置、条件、で操
作し、測定した輝度は５８３０ｃｄ／ｍ２であった（実
施例５）。更にプリズム状の突起の頂角を７０度にした
以外は実施例５と同一の装置、条件、で操作し、測定し
た輝度は５２３６ｃｄ／ｍ２であった（実施例６）。On the light-diffusing film, the prism-shaped protrusions made of polycarbonate have an apex angle of 90 degrees.
The brightness was 5830 cd / m 2 measured by operating under the same conditions and conditions as in Comparative Example 3 except that one sheet was arranged on the light emitting surface side of the planar light-emitting body so that the protruding surface was on the outside. (Example 5). Further, the brightness was 5236 cd / m 2 measured by operating under the same apparatus and conditions as in Example 5 except that the prism-shaped protrusion had an apex angle of 70 degrees (Example 6).
【００３２】つぎに、面状発光体から出光した光の一部
が前記シ−トのプリズム内部で全反射して再び面状発光
体へ戻される場合には、面状発光体の発光面以外の面が
反射率の高い反射板で覆われている程、効率の良いバッ
クライトになることを確認する実験を行った。すなわ
ち、出光面以外を覆っている３面の反射板を黒いマジッ
クで塗り潰した以外は比較例３と同一の装置、条件、で
操作し、測定した輝度は１６９０ｃｄ／ｍ２であった
（比較例４）。そして、前記光拡散フィルムの上にプリ
ズム状の突起の頂角が９０度の前記シ−トを突起面が外
側になるように面状発光体の出光面側に１枚配置した以
外は比較例４と同一の装置、条件、で操作し、測定した
輝度は２１５６ｃｄ／ｍ２であった（実施例７）。更に
プリズム状の突起の頂角を７０度にした以外は実施例７
と同一の装置、条件、で操作し、測定した輝度は２０３
５ｃｄ／ｍ２であった（実施例８）。Next, when a part of the light emitted from the planar light-emitting body is totally reflected inside the prism of the sheet and returned to the planar light-emitting body again, except the light-emitting surface of the planar light-emitting body. An experiment was conducted to confirm that the more the surface of (1) is covered with a reflector having a high reflectance, the more efficient the backlight becomes. That is, the measured brightness was 1690 cd / m 2 by operating with the same device and conditions as in Comparative Example 3 except that the three-sided reflective plate covering the surface other than the light emitting surface was painted with black magic. 4). A comparative example except that one sheet of the prism-shaped protrusion having an apex angle of 90 degrees is arranged on the light-diffusing film on the light emitting surface side of the planar light-emitting body so that the protrusion surface is on the outside. The device was operated under the same conditions and conditions as in Example 4, and the measured luminance was 2156 cd / m 2 (Example 7). Further, Example 7 was repeated except that the apex angle of the prism-shaped protrusions was set to 70 degrees.
Operated under the same equipment and conditions as above, the measured brightness was 203
It was 5 cd / m 2 (Example 8).
【図１】エッジライト方式のバックライトの一例を示す
図FIG. 1 is a diagram showing an example of an edge light type backlight.
【図２】直下ライト方式のバックライトの一例を示す図FIG. 2 is a diagram showing an example of a direct-light backlight.
【図３】平面蛍光ランプの一例を示す図FIG. 3 is a diagram showing an example of a flat fluorescent lamp.
【図４】本発明の一実施態様の斜視図FIG. 4 is a perspective view of an embodiment of the present invention.
【図５】本発明の一実施態様の断面図FIG. 5 is a cross-sectional view of one embodiment of the present invention.
【図６】光線追跡の一例を示す図FIG. 6 is a diagram showing an example of ray tracing.
【図７】プリズム頂角９０度の場合の例を示す図FIG. 7 is a diagram showing an example in which the prism vertical angle is 90 degrees.
【図８】プリズム頂角１２０度の場合の例を示す図FIG. 8 is a diagram showing an example in which the prism apex angle is 120 degrees.
【図９】本発明で用いた測定方法の概念図FIG. 9 is a conceptual diagram of a measuring method used in the present invention.
【図１０】出射光輝度の角度分布を示す図FIG. 10 is a diagram showing an angular distribution of emitted light brightness.
１：光源 ２：光拡散板 ３：反射板 ４：導光体 ５：ガラスパネル ６：蛍光面 ７：突起を持つ透光性シート ８：光拡散物質 ９：バックライト １０：輝度計 １１：出光面に降ろした法線方向に対する角度 1: Light source 2: Light diffusing plate 3: Reflecting plate 4: Light guide body 5: Glass panel 6: Fluorescent surface 7: Translucent sheet having protrusions 8: Light diffusing substance 9: Back light 10: Luminance meter 11: Light emission Angle with respect to the normal to the surface
Claims (4)
ズムまたは円錐状の突起を、微細な間隔で同一面に多数
有する透光性材料からなるシ−トを、突起面が外側にな
るように、面状発光体の出光面側に１枚以上配置したパ
ネル用バックライト。1. A sheet made of a translucent material having a large number of prisms or conical projections having portions with substantially the same apex angle on the same surface at minute intervals, and the projection surface is located outside. As described above, one or more panel backlights are arranged on the light emitting surface side of the planar light-emitting body.
トを用いる請求項１記載のパネル用バックライト。2. A sheet having protrusions having an apex angle of 70 to 150 degrees.
The backlight for a panel according to claim 1, wherein a backlight is used.
突起を用いる請求項１又は２記載のパネル用バックライ
ト。3. The backlight for a panel according to claim 1, wherein a protrusion having substantially the same length from the apex as each hypotenuse is used.
０〜１０００μｍであるシ−トを用いる請求項１〜３い
ずれか記載のパネル用バックライト。4. The distance between adjacent vertices of protrusions is 1
The backlight for panel according to any one of claims 1 to 3, wherein a sheet having a size of 0 to 1000 µm is used.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3233799A JPH063667A (en) | 1991-08-22 | 1991-08-22 | Backlight |
| JP03308196A JP3134422B2 (en) | 1991-08-22 | 1991-10-29 | Backlight |
| EP92114326A EP0534140B1 (en) | 1991-08-22 | 1992-08-21 | Backlighting device |
| US07/933,208 US5442523A (en) | 1991-08-22 | 1992-08-21 | Backlighting device |
| DE69220870T DE69220870T2 (en) | 1991-08-22 | 1992-08-21 | Rear lighting device |
| US08/466,747 US5730518A (en) | 1991-08-22 | 1995-06-06 | Backlighting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3233799A JPH063667A (en) | 1991-08-22 | 1991-08-22 | Backlight |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH063667A true JPH063667A (en) | 1994-01-14 |
Family
ID=16960762
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3233799A Pending JPH063667A (en) | 1991-08-22 | 1991-08-22 | Backlight |
| JP03308196A Expired - Fee Related JP3134422B2 (en) | 1991-08-22 | 1991-10-29 | Backlight |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03308196A Expired - Fee Related JP3134422B2 (en) | 1991-08-22 | 1991-10-29 | Backlight |
Country Status (1)
| Country | Link |
|---|---|
| JP (2) | JPH063667A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003059641A (en) * | 2001-08-09 | 2003-02-28 | Stanley Electric Co Ltd | Electroluminescent element |
-
1991
- 1991-08-22 JP JP3233799A patent/JPH063667A/en active Pending
- 1991-10-29 JP JP03308196A patent/JP3134422B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0659129A (en) | 1994-03-04 |
| JP3134422B2 (en) | 2001-02-13 |
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