JP2734954B2 - Backlight - Google Patents
BacklightInfo
- Publication number
- JP2734954B2 JP2734954B2 JP5321916A JP32191693A JP2734954B2 JP 2734954 B2 JP2734954 B2 JP 2734954B2 JP 5321916 A JP5321916 A JP 5321916A JP 32191693 A JP32191693 A JP 32191693A JP 2734954 B2 JP2734954 B2 JP 2734954B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- guide plate
- light guide
- light source
- plate
- 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.)
- Expired - Fee Related
Links
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 panel backlight for irradiating a transmissive or transflective panel from the back.
【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するエッジライト方式がよく
用いられる。このエッジライト方式の場合、図２に示す
ように、導光板の一方の面に光拡散物質を部分的に被覆
し、その面のほぼ全面を鏡面反射板又は光拡散反射板で
覆うように配置されたものが多い。2. Description of the Related Art Recently, a liquid crystal display device having a thin and easy-to-see backlight mechanism has been used as a display device such as a laptop or book type word processor or computer. As such a backlight, an edge light system in which a linear light source such as a fluorescent tube is provided at one end of a light-transmitting light guide plate as shown in FIG. 1 is often used. In the case of this edge light type, as shown in FIG. 2, one surface of the light guide plate is partially covered with a light diffusing substance, and almost the entire surface is arranged to be covered with a specular reflection plate or a light diffusion reflection plate. Many have been done.
【０００３】特に近時、これらワ−プロ、パソコンの性
能向上のため、小型化、視認性の向上、消費電力−輝度
変換効率の向上がより一層望まれているため、線状光源
を覆う光反射器に、反射率の高い光反射フィルムを配
し、導光板表面に両面テ−プ又は接着剤等で固定するこ
とが提案されている。[0003] In particular, recently, in order to improve the performance of these word processors and personal computers, miniaturization, improvement of visibility, and improvement of power consumption-luminance conversion efficiency have been further desired. It has been proposed that a light reflecting film having a high reflectance is arranged on a reflector and fixed to the surface of the light guide plate with a double-sided tape or an adhesive.
【０００４】前記したように、光反射フィルムを導光板
表面に両面テ−プ又は接着剤等で固定することの理由
は、固定部の厚さを両面テ−プ又は接着剤等の厚さ程度
（例えば０．１〜０．２ｍｍ）と薄くすることが出来る
からである。仮に前記固定部を外部から例えばプレ−ト
のようなもので押さえ付ける場合は充分な強度を持つプ
レ−トの厚さ（例えば１〜２ｍｍ）及び前記プレ−トの
固定（例えばプレ−ト両端をネジ等で固定する等）方法
が必要となる。その結果、固定部が厚くなり、例えばＴ
ＡＢ方式の液晶モジュ−ルをバックライトの上に配置し
たときなどの総厚が前記固定部の分（例えば１〜２ｍ
ｍ）だけ厚くなる。As described above, the reason why the light reflecting film is fixed to the surface of the light guide plate with a double-sided tape or an adhesive or the like is that the thickness of the fixing portion is about the thickness of the double-sided tape or the adhesive or the like. (For example, 0.1 to 0.2 mm). If the fixing portion is pressed from the outside with, for example, a plate, the thickness of the plate having sufficient strength (for example, 1 to 2 mm) and the fixing of the plate (for example, both ends of the plate) , Etc.) with screws or the like. As a result, the fixing portion becomes thicker, for example, T
When the liquid crystal module of the AB system is arranged on the backlight, the total thickness is equal to the fixed portion (for example, 1 to 2 m).
m).
【０００５】しかし、光反射フィルムと導光板表面とが
両面テ−プ又は接着剤等で接着固定された形態のもの
は、導光板表面に存在する空気が排除されるため、両面
テ−プ又は接着剤等が接着されている導光板表面では、
線状光源から導光板端部へ入射した光線が導光板表面で
全反射せずに、両面テ−プ又は接着剤等または接着の際
に巻き込まれた所々に存在する微細な空気で光拡散反射
され、結果的には両面テ−プ又は接着剤等が光を拡散さ
せる機能を有する光拡散エレメントを形成することにな
り、両面テ−プ又は接着剤等が接着されている導光板表
面近傍が異常発光し、その分、光の損失となるばかりで
なく、前記異常発光部（高輝度部）が両面テ−プ又は接
着剤等が接着されている導光板表面から中央部方向に現
れ視認性が著しく悪化し、その分導光板面上の輝度分布
が均一ないわゆる有効発光面積が減少する問題があっ
た。However, in the case where the light reflection film and the surface of the light guide plate are bonded and fixed with a double-sided tape or an adhesive or the like, air existing on the surface of the light guide plate is removed, so that the double-sided tape or the light guide plate is removed. On the surface of the light guide plate to which the adhesive etc. is adhered,
Light rays incident on the end of the light guide plate from the linear light source are not totally reflected on the surface of the light guide plate, but are diffusely reflected by the double-sided tape or an adhesive or the fine air present in various places caught during bonding. As a result, a double-sided tape or an adhesive or the like forms a light diffusing element having a function of diffusing light, and the vicinity of the surface of the light guide plate to which the double-sided tape or the adhesive or the like is adhered is formed. In addition to abnormal light emission, not only loss of light is caused, but also the abnormal light emitting portion (high brightness portion) appears from the surface of the light guide plate to which the double-sided tape or the adhesive or the like is adhered toward the central portion, and the visibility is increased. And the so-called effective light-emitting area, in which the brightness distribution on the light guide plate surface is uniform, is reduced.
【０００６】光反射フィルムと導光板表面とが両面テ−
プ又は接着剤等で接着固定された場合に発生する前記異
常発光部（高輝度部）を解消する方法として、実開平４
−４６４８５に開示されているように黒暗色の接着剤を
使用する方法がある。この方法は異常発光部（高輝度
部）は殆ど消滅するものの、光吸収部が、接着部分で拡
散反射された異常発光（高輝度）の原因となる光線以外
の通常の光線をも吸収してしまうため、導光板の発光面
内の平均輝度が低下してしまう問題があった。[0006] The light reflecting film and the surface of the light guide plate have a double-sided tape.
As a method for eliminating the abnormal light-emitting portion (high-brightness portion) that occurs when the light-emitting portion is fixed by bonding with a lamp or an adhesive, there is disclosed in
There is a method of using a black and dark adhesive as disclosed in US Pat. In this method, although the abnormal light-emitting portion (high-brightness portion) almost disappears, the light-absorbing portion absorbs ordinary light other than the light that causes the abnormal light emission (high-brightness) diffusely reflected at the bonding portion. Therefore, there is a problem that the average luminance in the light emitting surface of the light guide plate is reduced.
【０００７】[0007]
【発明が解決しようとする課題】本発明の目的は、異常
発光部（高輝度部）が極めて少なく、外形寸法に対して
比較的有効発光面積が大きく小型でかつ消費電力−輝度
変換効率が高い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 an extremely small number of abnormal light-emitting portions (high-brightness portions), a relatively large effective light-emitting area with respect to the outer dimensions, a small size, and a high power-to-brightness conversion efficiency. It is to provide a backlight.
【０００８】[0008]
【課題を解決するための手段】本発明者等は、バックラ
イトの線状光源近傍の構造と導光板出光面の輝度分布に
ついて種々の検討を行った結果、エッジライト方式のバ
ックライトに於いて、線状光源を覆った光反射板又は光
反射フィルムの端部と導光板の接点の状態が、ある状態
の時に異常発光部（高輝度部）が極めて少なく外形寸法
に対して比較的有効発光面積が大きく小型でかつ消費電
力−輝度変換効率が高いバックライトとなることを見出
した。The present inventors have conducted various studies on the structure of the backlight in the vicinity of the linear light source and the luminance distribution on the light exit surface of the light guide plate. When the state of the contact between the light reflecting plate or the end of the light reflecting film that covers the linear light source and the light guide plate is in a certain state, the number of abnormal light emitting portions (high-brightness portions) is extremely small and light emission is relatively effective for the external dimensions. It has been found that a backlight having a large area, a small size, and high power consumption-luminance conversion efficiency can be obtained.
【０００９】即ち本発明は、透光性材料からなる導光板
の一方の広い面に光を拡散させる機能を有する光拡散エ
レメントを形成し、その面を鏡面ないし光拡散反射板又
はフィルムで覆い、前記導光板の少なくとも一側面端部
に、これに近接した線状光源を有するパネル用バックラ
イトに於いて、線状光源を覆った光反射板又は光反射フ
ィルムの端部の一方が、線状光源が近接した導光板の出
光面側の端部に接着されており、この接着部分に対応す
る導光板の裏面部分は空気層を介して光吸収部で覆われ
たことを特徴とする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 light diffusing element having a function of diffusing light is formed on one wide surface of a light guide plate made of a translucent material, and the surface is covered with a mirror surface or a light diffusive reflection plate or film. At least one side edge of the light guide plate, in a panel backlight having a linear light source adjacent thereto, one of the ends of the light reflection plate or the light reflection film covering the linear light source is linear. A light source is adhered to an end of the light guide plate adjacent to the light emitting surface side, and a back surface portion of the light guide plate corresponding to the adhered portion is covered with a light absorbing portion via an air layer. This is related to the backlight.
【００１０】次に本発明を図面に基づいて更に詳述す
る。Next, the present invention will be described in more detail with reference to the drawings.
【００１１】図１は、本発明の一実施態様の斜視図であ
り、図２は、同断面図である。図中１は導光板であり、
光を効率よく通過させる物質であればよく、石英、ガラ
ス、透光性の天然又は合成樹脂、例えばアクリル系樹脂
等である。２は光拡散板で、導光板面より出光した光を
散乱させて通過させるものである。本発明では、この光
拡散板を一枚又は複数枚用いる。FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view of the embodiment. 1 is a light guide plate in the figure,
Any substance can be used as long as the substance allows light to pass therethrough efficiently, such as quartz, glass, or a translucent natural or synthetic resin such as an acrylic resin. Reference numeral 2 denotes a light diffusing plate that scatters light emitted from the light guide plate and allows the light to pass therethrough. In the present invention, one or more light diffusion plates are used.
【００１２】導光板１の一方の広い面に形成する光拡散
エレメントは、例えば、光散乱物質を施すなどで形成す
るが、これは、拡散反射率が大きい顔料を含んだ塗料、
印刷インキ等をスクリ−ン印刷等の方法で導光板面上に
ドット状に印刷するなどして行う。その他、導光板の表
面を粗面化するか、小孔を開けるか、小突起を付与する
などして光拡散性を付与しても良い。The light diffusing element formed on one wide surface of the light guide plate 1 is formed, for example, by applying a light scattering substance, which is composed of a paint containing a pigment having a large diffuse reflectance.
Printing is performed by printing printing ink or the like in a dot pattern on the light guide plate surface by a method such as screen printing. In addition, light diffusion may be provided by roughening the surface of the light guide plate, making small holes, or providing small projections.
【００１３】鏡面ないし光拡散反射板３は光散乱物質を
被覆した導光板の面のほぼ全面を覆うように配置する。
４は線状光源で、好ましい態様としては、導光板の端部
に光が入光するように線状光源の中心軸が同端面と平行
となるように配置し、線状光源の、導光板の端部と相対
する面以外の表面を光反射板又は光反射フィルム５で覆
う状態で配置することである。The mirror surface or the light diffusion reflector 3 is disposed so as to cover almost the entire surface of the light guide plate coated with the light scattering material.
Reference numeral 4 denotes a linear light source, which is preferably arranged such that the central axis of the linear light source is parallel to the end surface so that light enters the end of the light guide plate. Is arranged so as to cover a surface other than the surface opposed to the end with the light reflecting plate or the light reflecting film 5.
【００１４】本発明で、線状光源を覆う光反射板又は光
反射フィルムに鏡面反射板又は鏡面反射フィルムを用い
る場合は、光を鏡面反射させるものであれば良く、銀、
アルミニウム、白金、ニッケル、クロム等からなる材質
で、好ましくはポリエステルなどのプラスチックフィル
ム基材に銀、アルミニウム等を蒸着またはスパッタリン
グにより表面コ−トしたものである。このような鏡面反
射率が高く（例えば銀は鏡面反射率９０〜９５％）、薄
い（例えば、市販のポリエステルの基材に銀を蒸着した
ものは厚さ７５μｍ程度）鏡面反射板又は鏡面反射フィ
ルムを用いることによって、消費電力−輝度変換効率が
高く、特に導光体部の厚さに比較して厚くなっていた線
状光源部の厚さを薄くすることができる。尚、更に消費
電力−輝度変換効率を向上させるために、本発明者らが
すでに出願した（特願平３−６７６９９）方法を併せて
用いればさらに消費電力−輝度変換効率が向上する。In the present invention, when a specular reflector or a specular reflection film is used as the light reflection plate or the light reflection film covering the linear light source, any material that reflects light specularly may be used.
A material made of aluminum, platinum, nickel, chromium, or the like, preferably a material obtained by depositing silver, aluminum, or the like on a plastic film base material such as polyester by vapor deposition or sputtering. Such a mirror-reflector or a mirror-reflective film having a high specular reflectivity (for example, silver has a specular reflectivity of 90 to 95%) and is thin (for example, a commercially available polyester base material obtained by depositing silver has a thickness of about 75 μm). Is used, the power consumption-luminance conversion efficiency is high, and in particular, the thickness of the linear light source portion, which has become thicker than the thickness of the light guide portion, can be reduced. If the method of the present inventors already applied (Japanese Patent Application No. 3-67699) is used in combination to further improve the power consumption-luminance conversion efficiency, the power consumption-luminance conversion efficiency is further improved.
【００１５】本発明の特徴である線状光源を覆った光反
射板又は光反射フィルムの端部と導光板の接点の状態
は、図３に示すように、線状光源を覆う光反射板又は光
反射フィルムの導光板の出光面側の端部（図中７）が、
導光板の端部の出光面の表面と例えば両面テ−プ又は接
着剤等（図中８）で接着されており、前記接着された部
分の裏面側の、相対する部分の導光板表面が、空気層を
介して光吸収部で覆われている状態である。As shown in FIG. 3, the state of the contact point between the end of the light reflecting plate or the light reflecting film covering the linear light source and the light guide plate, which is a feature of the present invention, is as follows. The end (7 in the figure) of the light guide plate of the light reflecting film on the light emitting surface side is
The light guide surface at the end of the light guide plate is adhered to the surface of the light guide surface by, for example, a double-sided tape or an adhesive (8 in the figure). It is in a state where it is covered with the light absorbing portion via the air layer.
【００１６】ここで言う空気層の厚さは、特に制限され
ないが、最大の厚さはバックライトの薄型化のためには
薄い方がよく、好ましくは０．５ｍｍ以下、最小の厚さ
は少なくとも単分子層の分子が存在する程度の間隔で良
い。又、光吸収部は黒色等の光を吸収する性質を持つ形
態を有するもので良く、本発明で該当する部分を例えば
黒色に着色するか、黒色に着色した部材で構成すれば良
い。 The thickness of the air layer referred to herein is not particularly limited, but the maximum thickness is preferably thinner for making the backlight thinner, preferably 0.5 mm or less, and the minimum thickness is at least. The spacing may be such that the molecules of the monolayer exist. The light absorbing part has the property of absorbing light such as black.
It may have a state, for example, the portion corresponding to the present invention
It should be colored black or composed of black colored members.
No.
【００１７】線状光源を覆った光反射板又は光反射フィ
ルムの他方（導光板の端部に接着した側の反対側）の端
部は、前記鏡面ないし光拡散反射板又はフィルム（３）
の外側（導光板に面していない側）に接着されている
（図中９）か、更に外側の構造物で挟持されているかし
て、少なくとも線状光源を覆った状態であれば良い。The other end (the side opposite to the side adhered to the end of the light guide plate) of the light reflecting plate or the light reflecting film which covers the linear light source is the mirror surface or the light diffusion reflecting plate or film (3).
It is sufficient if it adheres to the outside (the side not facing the light guide plate) (see 9 in the figure) or is sandwiched by a further outside structure, so long as it covers at least the linear light source.
【００１８】尚、前記した導光板裏面の空気層を介して
光吸収部で覆われている以外の導光板表面は、鏡面ない
し光拡散反射板又はフィルム（３）で覆われていても良
い。ここで用いる光拡散反射板又はフィルムは、光を拡
散反射させるものであれば良く、ポリエステルなどの樹
脂に光拡散性物質（例えばＴｉＯ2、ＢａＳＯ4、ＳｉＯ
2など）を混入させたもの、ポリエステルなどの樹脂を
発砲させて光拡散性を付与したもの、Ａｌ板などに前記
光拡散性物質を塗布したものなどがあるが、入射した光
線を拡散反射する性質があれば良くその材質は特に限定
されない。Incidentally, the surface of the light guide plate other than the surface covered with the light absorbing portion via the air layer on the back surface of the light guide plate may be covered with a mirror surface or a light diffuse reflection plate or a film (3). The light-diffusing reflector or film used here may be any as long as it diffuses and reflects light, and a light-diffusing substance (for example, TiO 2 , BaSO 4 , SiO
2 ), a resin such as polyester, which has a light diffusing property, and an Al plate or the like coated with the light diffusing substance. The material is not particularly limited as long as it has properties.
【００１９】前記線状光源４は、蛍光管、タングステン
白熱管、オプティカルロッド、ＬＥＤを配列した物等が
あるが、蛍光管が好ましく、有効発光面積の輝度分布の
均一性の面及び省電力の面から、電極部を除く均一発光
部の長さが、近接する導光板の端部の長さとほぼ等しい
ことが好ましい。The linear light source 4 includes a fluorescent tube, a tungsten incandescent tube, an optical rod, an LED and the like, but a fluorescent tube is preferable. From the surface, it is preferable that the length of the uniform light emitting portion excluding the electrode portion is substantially equal to the length of the end portion of the adjacent light guide plate.
【００２０】本発明の主要部は、このような構成からな
り、パネル、特に液晶パネルのバックライトとして使用
される。本発明では、更に以下に示すような構成とする
ことが好ましい。The main part of the present invention has such a structure and is used as a backlight of a panel, especially a liquid crystal panel. In the present invention, it is preferable to adopt the following configuration.
【００２１】即ち、本発明の導光板に施す光拡散物質
は、好ましくはドット状即ち点状に形成するものである
が、このドットの形状は特に制限されるものでなく、円
形、角形、交差線で形成されたいづれでもよい。これら
は導光板上に仮想される一定の間隔を持った直交線の交
点（グリッド）上に施されるが、直交線の間隔は０．５
〜３ｍｍ更に好ましくは０．８〜２ｍｍの間で導光板の
厚さに応じて適宜選択される。That is, the light diffusing substance applied to the light guide plate of the present invention is preferably formed in a dot shape, that is, a dot shape. However, the shape of the dot is not particularly limited, and may be a circle, a square, or an intersection. Any line may be formed. These are applied on intersections (grids) of orthogonal lines having a certain interval imaginary on the light guide plate, and the interval between the orthogonal lines is 0.5
To 3 mm, more preferably 0.8 to 2 mm, depending on the thickness of the light guide plate.
【００２２】更に、前記光拡散物質の被覆状態は、導光
板面上で線状光源部近傍で被覆率が１％〜５０％、光源
から最遠部で２０％〜１００％であることが好ましく、
光源からの距離が大となるにつれて、光源から線状光源
を近接させた一側面端部の被覆点から始めて被覆率が順
次大となるように被覆することが好ましい。ここで言う
被覆率とは、導光板面の単位面積当たりに施した光散乱
物質の被覆面積の割合を言う。Further, the covering state of the light diffusing substance is preferably 1% to 50% in the vicinity of the linear light source portion on the light guide plate surface, and 20% to 100% in the farthest portion from the light source. ,
As the distance from the light source increases, it is preferable to cover the linear light source from the light source such that the coverage gradually increases starting from the coating point on one side end where the linear light source is brought closer. The term “coverage” as used herein refers to the ratio of the light scattering substance covering area applied per unit area of the light guide plate surface.
【００２３】[0023]
【発明の効果】本発明は異常発光部（高輝度部）がな
く、外形寸法に対して有効発光面積が比較的大きくかつ
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。According to the present invention, there is no abnormal light emitting portion (high brightness portion), the effective light emitting area is relatively large with respect to the external dimensions, and the power consumption-luminance conversion efficiency can be used as a backlight.
【００２４】[0024]
【実施例】次に実施例及び比較例で本発明を更に詳述す
る。図１に示すような厚さ４ｍｍの長方形アクリル板
（２０５ｍｍ×１６０ｍｍ、旭化成株式会社製デラグラ
スＡ）の長手の両端部に、直径３．８ｍｍ長さ２３０ｍ
ｍ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、図２に示すように、その管の外周を
銀フィルム（中井工業株式会社製）で覆い、銀フィルム
の導光板端部と対向する幅４ｍｍの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。Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. As shown in FIG. 1, a rectangular acrylic plate (205 mm × 160 mm, Delaglass A manufactured by Asahi Kasei Corporation) having a thickness of 4 mm was provided on both ends of a longitudinal side at a diameter of 3.8 mm and a length of 230 m.
m cold cathode fluorescent tube (Harrison Electric Co., Ltd.
2), and as shown in FIG. 2, the outer periphery of the tube is covered with a silver film (manufactured by Nakai Industries Co., Ltd.), and light emitted from a slit having a width of 4 mm facing the end of the light guide plate of the silver film is generated. The light guide plate was arranged so as to enter the light guide plate from the end.
【００２５】一方、導光板面上には光散乱物質（チタニ
ア）を含むインクを円形のドットパタ−ンで１ｍｍピッ
チでスクリ−ン印刷し、スクリ−ン版下は、下記の条件
でＣＡＤを用いて作成した。光拡散物質の被覆率が、最
小の地点（線状光源近傍）で２０％、最大の地点（導光
板中央部）で９５％、その中間では被覆率が最小の地点
からこれらの比率を順次増加した値となるように作図し
た。On the other hand, an ink containing a light scattering substance (titania) is screen-printed on the light guide plate surface in a circular dot pattern at a pitch of 1 mm, and a CAD is used under the screen plate under the following conditions. Created. The light-diffusing substance coverage is 20% at the minimum point (near the linear light source), 95% at the maximum point (center of the light guide plate), and in the middle, these ratios are sequentially increased from the point with the minimum coverage. The plot was made so that the obtained value was obtained.
【００２６】厚さ０．１３ｍｍのポリエステルからなる
白色の光拡散反射板（ＩＣＩ社製メリネックス３２９）
は導光板の光散乱物質を被覆した面の全面を覆うように
配置した。厚さ０．１８ｍｍのポリカ−ボネ−トからな
る光拡散板（ＧＥ社製８Ｂ３６）は粗面側が導光板側と
は反対側になるようにして、導光板の出光面のほぼ全面
を覆うように配置した。A white light diffusion reflector made of polyester having a thickness of 0.13 mm (Melinex 329 manufactured by ICI)
Was disposed so as to cover the entire surface of the light guide plate coated with the light scattering material. The light diffusing plate (8B36 manufactured by GE) made of polycarbonate having a thickness of 0.18 mm is formed so that the rough surface side is opposite to the light guide plate side so as to cover almost the entire light exit surface of the light guide plate. Was placed.
【００２７】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（菅電流５ｍＡ）で駆動させ
たときの面輝度を、輝度計（トプコンＢＭ−８）により
測定した。The surface luminance when a 30 KHz alternating voltage was applied to the cold cathode tube from the inverter and driven at a constant current (tube current: 5 mA) was measured by a luminance meter (Topcon BM-8).
【００２８】（実施例）図３に示すように、鏡面反射フ
ィルム（光源を覆うＡｇフィルム）の導光板の出光面側
の端部を、導光板の出光面の表面と、幅３．５ｍｍ厚さ
０．１６ｍｍの両面テ−プ（株式会社寺岡製作所製ＷＰ
Ｔ−Ｎｏ７５０Ｆ）で接着し（図３の８）、前記両面テ
−プで接着された部分と相対する導光板の裏面側部分
が、空気層を介して光吸収部で覆われるように、鏡面反
射フィルムの空気層を介して導光板と対向する面を黒色
で塗り潰した。尚、Ａｇフィルムの端部は、光拡散反射
板の導光板と対向する側の面に前記両面テ−プで接着し
た。この時の有効発光面積内の９９点（均等割り）平均
輝度は１２６５ｃｄ／ｍ2であった。(Embodiment) As shown in FIG. 3, the end of the specular reflection film (Ag film covering the light source) on the light exit surface side of the light guide plate was set to the surface of the light exit surface of the light guide plate and the width of 3.5 mm. 0.16mm double-sided tape (WP manufactured by Teraoka Seisakusho Co., Ltd.)
(T-No. 750F) (8 in FIG. 3), and a mirror surface such that the back surface side of the light guide plate opposite to the portion bonded with the double-sided tape is covered with the light absorbing portion via the air layer. The surface of the reflective film facing the light guide plate via the air layer was painted black. The end of the Ag film was adhered to the surface of the light diffusion reflection plate facing the light guide plate by the double-sided tape. At this time, 99 points (equally divided) average luminance within the effective light emitting area was 1265 cd / m 2 .
【００２９】又、鏡面反射フィルムの導光板の出光面側
の端部近傍は異常発光部（高輝度部）にならずにむしろ
輝度が低下した。そして輝度が低下した領域は線状光源
から離れる方向にほぼ６ｍｍの地点で消滅し、輝度が低
下した領域の最低輝度は８５０ｃｄ／ｍ2（平均輝度の
約０．７倍）であった。The vicinity of the end of the light guide surface of the light guide plate of the specular reflection film did not become an abnormal light emitting portion (high brightness portion), but rather decreased in brightness. The area where the luminance was reduced disappeared at a point approximately 6 mm away from the linear light source, and the minimum luminance of the area where the luminance was reduced was 850 cd / m 2 (about 0.7 times the average luminance).
【００３０】尚、光吸収部は黒色等の光を吸収する性質
を有するものであれば良く、光吸収部は鏡面反射フィル
ム上の必要な部分に形成しても良いし、導光板の光散乱
物質を被覆した面の全面を覆う反射板上の必要な部分に
形成しても良く、結果的に接着部分に対応する導光板の
裏面部分は空気層を介して光吸収部で覆われた状態であ
れば良く光吸収部を機構的に保持する方法は特に限定さ
れない。The light absorbing portion only needs to have a property of absorbing light such as black, and the light absorbing portion may be formed at a necessary portion on the specular reflection film or the light scattering of the light guide plate. The light guide plate may be formed on a necessary portion on the reflector that covers the entire surface coated with the substance. As a result, the back surface of the light guide plate corresponding to the adhesive portion is covered with the light absorbing portion via the air layer. The method of mechanically holding the light absorbing portion is not particularly limited as long as it is sufficient.
【００３１】本発明の特徴は接着部分に対応する導光板
の裏面部分が空気層を介して光吸収部で覆われたことに
ある。導光板と光吸収部との間に空気層が介在すること
によって、光吸収部は接着部分で拡散反射された異常発
光（高輝度）の原因となる光線のみを吸収しすることが
出来、しかも、線状光源から導光板端部へ入射した接着
部分で拡散反射された異常発光（高輝度）の原因となる
光線以外の通常の光線がなおも導光板表面で全反射する
ことが出来る。従って、前記通常の光線の光吸収部への
吸収をなくすことができるので光の損失を防止すること
になり、異常発光部（高輝度部）が極めて少なく消費電
力−輝度変換効率が大なバックライトが得られるのであ
る。A feature of the present invention resides in that the back surface portion of the light guide plate corresponding to the adhesive portion is covered with a light absorbing portion via an air layer. Since the air layer is interposed between the light guide plate and the light absorbing portion, the light absorbing portion can absorb only light rays that cause abnormal light emission (high brightness) diffusely reflected at the bonding portion, and Normal rays other than those causing extraordinary light emission (high brightness) diffusely reflected at the bonding portion incident on the end of the light guide plate from the linear light source can still be totally reflected on the surface of the light guide plate. Therefore, it is possible to eliminate the absorption of the ordinary light beam into the light absorbing portion, thereby preventing light loss, and reducing the number of extraordinary light emitting portions (high brightness portions) to a large power consumption-luminance conversion efficiency. You get the light.
【００３２】（比較例１）図４（ａ）に示すように、導
光板の出光面の表面にＡｇフィルムを接着する前に、導
光板のその部分をあらかじめ黒色で塗り潰しＡｇフィル
ムを接着し、鏡面反射フィルムの空気層を介して導光板
と対向する面を黒色で塗り潰さなかった以外は実施例と
同様な配置にした。この時の平均輝度は１０００ｃｄ／
ｍ2（実施例に対して約２０％低下）であった。又、鏡
面反射フィルムの導光板の出光面側の端部近傍は異常発
光部（高輝度部）にならず輝度が低下した。そして輝度
が低下した領域は線状光源から離れる方向にほぼ６ｍｍ
の地点で消滅し、輝度が低下した領域の最低輝度は５５
０ｃｄ／ｍ2（平均輝度の約０．６倍）であった。この
ように、導光板と光吸収部が空気層を介せずに直接接し
ている場合は光吸収部が接着部分で拡散反射された異常
発光（高輝度）の原因となる光線以外の通常の光線をも
吸収してしまうため、導光板の発光面内の平均輝度が著
しく低下してしまい、消費電力−輝度変換効率が小とな
ってしまった。(Comparative Example 1) As shown in FIG. 4 (a), before bonding the Ag film to the surface of the light emitting surface of the light guide plate, the portion of the light guide plate was previously painted black and the Ag film was bonded. The arrangement was the same as in the example except that the surface of the specular reflection film facing the light guide plate via the air layer was not painted black. The average luminance at this time is 1000 cd /
m 2 (about 20% reduction with respect to the example). Further, the vicinity of the light-emitting surface side end of the light guide plate of the specular reflection film did not become an abnormal light-emitting portion (high-brightness portion), and the luminance was reduced. The area where the luminance is reduced is approximately 6 mm away from the linear light source.
At the point of, and the minimum luminance of the area where the luminance is reduced is 55
0 cd / m 2 (about 0.6 times the average luminance). As described above, when the light guide plate and the light absorbing portion are in direct contact with each other without passing through the air layer, the light absorbing portion is diffused and reflected at the bonding portion, and is not a light beam that causes abnormal light emission (high brightness). Since it also absorbs light, the average luminance in the light emitting surface of the light guide plate is significantly reduced, and the power consumption-luminance conversion efficiency is reduced.
【００３３】（比較例２）図４（ｂ）に示すように、Ａ
ｇフィルムを空気層及び光吸収部を介さずに前記両面テ
−プで導光板の裏面側部分にも接着した以外は実施例１
と同様な配置にした。この時の平均輝度は１２００ｃｄ
／ｍ2（実施例に対して約５％低下）であった。そして
鏡面反射フィルムの導光板の出光面側の端部近傍の異常
発光部（高輝度部）は線状光源から離れる方向にほぼ８
ｍｍの地点で消滅し、異常発光部（高輝度部）の最大輝
度は２７００ｃｄ／ｍ2（平均輝度の約２倍）であっ
た。Comparative Example 2 As shown in FIG.
Example 1 except that the g film was adhered to the back surface side of the light guide plate by the double-sided tape without passing through the air layer and the light absorbing portion.
The same arrangement was used. The average luminance at this time is 1200 cd
/ M 2 (about 5% lower than the example). The abnormal light-emitting portion (high-brightness portion) near the end on the light-emitting surface side of the light guide plate of the specular reflection film is approximately 8 away from the linear light source.
mm, and the maximum luminance of the abnormal light emitting part (high luminance part) was 2700 cd / m 2 (about twice the average luminance).
【００３４】そして、このような異常発光部（高輝度
部）は視認性を著しく悪化させた。The abnormal light-emitting portion (high-brightness portion) markedly deteriorated the visibility.
【図１】本発明の一実施態様のバックライトの斜視図FIG. 1 is a perspective view of a backlight according to an embodiment of the present invention.
【図２】本発明の光源部の一実施態様の断面図FIG. 2 is a sectional view of an embodiment of the light source unit of the present invention.
【図３】線状光源を覆う光反射フィルムと導光板端部と
の配置を示す本発明の１実施態様の図FIG. 3 is a view of one embodiment of the present invention showing an arrangement of a light reflecting film covering a linear light source and an end portion of a light guide plate.
【図４】線状光源を覆う光反射フィルムと導光板端部と
の配置を示す比較例の図FIG. 4 is a diagram of a comparative example showing an arrangement of a light reflecting film covering a linear light source and an end portion of a light guide plate.
１：導光板 ２：光拡散板 ３：鏡面反射板又は光拡散射板 ４：線状光源 ５：光反射板又はフィルム ６：光散乱物質 ７：鏡面反射フィルムの導光板の出光面側の端部 ８：両面テ−プ又は接着剤等 ９：光吸収部 １０：空気層 1: Light guide plate 2: Light diffusion plate 3: Specular reflection plate or light diffusion projection plate 4: Linear light source 5: Light reflection plate or film 6: Light scattering material 7: Light emitting surface side end of light guide plate of mirror reflection film Part 8: Double-sided tape or adhesive, etc. 9: Light absorbing part 10: Air layer
Claims (1)
面に光を拡散させる機能を有する光拡散エレメントを形
成し、その面を鏡面ないし光拡散反射板又はフィルムで
覆い、前記導光板の少なくとも一側面端部に、これに近
接した線状光源を有するパネル用バックライトに於い
て、線状光源を覆った鏡面反射板又は鏡面反射フィルム
の端部の一方が、線状光源が近接した導光板の出光面側
の端部に接着されており、この接着部分に対応する導光
板の裏面部分は空気層を介して光吸収部で覆われたこと
を特徴とするパネル用バックライト。A light-diffusing element having a function of diffusing light on one wide surface of a light-guiding plate made of a light-transmitting material, and the surface is covered with a mirror surface or a light-diffusing reflector or a film; In a panel backlight having a linear light source close to at least one side end thereof, one end of a specular reflection plate or a specular reflection film covering the linear light source is close to the linear light source. Outgoing surface side of light guide plate
And a back surface portion of the light guide plate corresponding to the bonded portion is covered with a light absorbing portion via an air layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5321916A JP2734954B2 (en) | 1993-12-21 | 1993-12-21 | Backlight |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5321916A JP2734954B2 (en) | 1993-12-21 | 1993-12-21 | Backlight |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4168338A Division JP2980776B2 (en) | 1992-06-04 | 1992-06-04 | Backlight |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06222364A JPH06222364A (en) | 1994-08-12 |
| JP2734954B2 true JP2734954B2 (en) | 1998-04-02 |
Family
ID=18137844
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5321916A Expired - Fee Related JP2734954B2 (en) | 1993-12-21 | 1993-12-21 | Backlight |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2734954B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2913497B2 (en) | 1993-04-12 | 1999-06-28 | 東ソー株式会社 | Backlight |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3012462B2 (en) * | 1994-09-26 | 2000-02-21 | 富士通株式会社 | Light guide plate, surface light source and non-light emitting display device using the same |
| KR100278604B1 (en) * | 1996-09-13 | 2001-01-15 | 윤종용 | backlight assembly for improving an optical uniformity |
| KR100389058B1 (en) * | 2001-07-19 | 2003-06-25 | 오츠타이어 가부시키가이샤 | Back light |
| JP4883745B2 (en) * | 2004-01-27 | 2012-02-22 | 日東電工株式会社 | Adhesive tape |
| WO2012164696A1 (en) * | 2011-06-01 | 2012-12-06 | 興和株式会社 | Illumination device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2503474Y2 (en) * | 1990-05-28 | 1996-07-03 | オーツタイヤ株式会社 | Light guide plate device |
| JPH0446485U (en) * | 1990-08-24 | 1992-04-20 | ||
| JP2570776Y2 (en) * | 1992-01-31 | 1998-05-13 | 日本電気ホームエレクトロニクス株式会社 | Backlight unit |
-
1993
- 1993-12-21 JP JP5321916A patent/JP2734954B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2913497B2 (en) | 1993-04-12 | 1999-06-28 | 東ソー株式会社 | Backlight |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06222364A (en) | 1994-08-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5392199A (en) | Back lighting device | |
| EP0674133B1 (en) | Backlighting device | |
| JPH07114024A (en) | Back light | |
| JP2734954B2 (en) | Backlight | |
| JP2982549B2 (en) | Backlight | |
| JP3627274B2 (en) | Backlight | |
| JP3500725B2 (en) | Backlight | |
| JP3550771B2 (en) | Backlight | |
| JP3500726B2 (en) | Backlight | |
| JPH06308489A (en) | Back light for panel | |
| JP3528261B2 (en) | Backlight for panel | |
| JP3306792B2 (en) | Backlight for LCD panel | |
| JP2913497B2 (en) | Backlight | |
| JP3078063B2 (en) | Backlight for panel | |
| JP2624059B2 (en) | Backlight for panel | |
| JP2730310B2 (en) | Backlight for panel | |
| JP3218750B2 (en) | Backlight for panel | |
| JP3559855B2 (en) | Backlight | |
| JPH0561046A (en) | Back light for panel | |
| JP3203859B2 (en) | Backlight | |
| JP2560583B2 (en) | Backlight for panel | |
| JPH06308490A (en) | Back light | |
| JPH04280225A (en) | Back light | |
| JPH06308493A (en) | Back light | |
| JPH07211115A (en) | Back light for panel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |