JP2794909B2 - Backlight for panel - Google Patents
Backlight for panelInfo
- Publication number
- JP2794909B2 JP2794909B2 JP2172809A JP17280990A JP2794909B2 JP 2794909 B2 JP2794909 B2 JP 2794909B2 JP 2172809 A JP2172809 A JP 2172809A JP 17280990 A JP17280990 A JP 17280990A JP 2794909 B2 JP2794909 B2 JP 2794909B2
- 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
Landscapes
- Liquid Crystal (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
- Optical Elements Other Than Lenses (AREA)
Description
【発明の詳細な説明】 ［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。Description: 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.
［従来の技術］ 近時、ラップトップ型又は、ブック型のワードプロセ
ッサーやコンピュー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。[Related Art] In recent years, a liquid crystal display device having a thin and easy-to-see backlight mechanism has been used as a display device of 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.
このエッジライト方式の場合、均一な面発光を得よう
とする場合は、通常、蛍光管の口金、電極部の無発光部
を除いた有効発光長を、導光板表示部分に相当する端面
の長さより長くすることが考えられる。しかし、この方
法では、液晶表示面に対して器具全体が大型となるとい
う問題があること、導光板へ入射されない無駄な光が多
くなり、電力−輝度変換効率が悪いという問題がある。
一方、導光板に何等かの導光方策を施して導光板の端部
長に等しいか、又はそれ以下の蛍光管を用いることが出
来たとしても、蛍光管の電極付近は、点灯経時と共に黒
化する傾向があるため、通電の初期には、均一な面発光
が得られても、導光板上で電極付近より光が誘導された
部分は経時と共に輝度が低下し、面全体の輝度分布は不
均一になるという問題がある。In the case of this edge light method, when uniform surface light emission is to be obtained, the effective light emission length excluding the base of the fluorescent tube and the non-light-emitting portion of the electrode portion is usually set to the length of the end surface corresponding to the light guide plate display portion. It could be longer. However, in this method, there is a problem that the whole device becomes large with respect to the liquid crystal display surface, and there is a problem that wasteful light that does not enter the light guide plate increases and power-luminance conversion efficiency is poor.
On the other hand, even if a light guide plate is subjected to some light guide measures and a fluorescent tube equal to or less than the end length of the light guide plate can be used, the vicinity of the electrode of the fluorescent tube becomes black with the lighting time. Therefore, even when uniform surface light emission is obtained at the beginning of energization, the brightness of the portion where light is guided from the vicinity of the electrode on the light guide plate decreases with time, and the brightness distribution of the entire surface is poor. There is a problem of uniformity.
［発明が解決しようとする問題点］ 本発明は、上述の点に鑑み、線状光源を設置する導光
板入光部の端部長に等しいかそれ以下の長さの線状光源
を用い、かつ用いる線状光源の周囲を、導光板への入射
部分に間隙（スリット）を有する光拡散反射器で、線状
光源の表面から間隙を持たせた状態で覆い、かつ、前記
導光板の広い面の一方の面に該導光板材料よりも屈折率
が大なる光拡散物質をある条件下に部分的に被覆し、そ
の面を鏡面ないし光拡散反射板で覆い、導光板の他方の
面（出光面）に複数枚の光拡散板を配したパネル用バッ
クライトに関するものである。[Problems to be Solved by the Invention] In view of the above points, the present invention uses a linear light source having a length equal to or less than the end length of the light guide plate light-receiving portion on which the linear light source is installed, and A light diffusion reflector having a gap (slit) at a portion where the linear light source is incident on the light guide plate is covered with a gap from the surface of the linear light source, and a wide surface of the light guide plate is used. One surface of the light guide plate is partially covered with a light diffusing substance having a higher refractive index than that of the light guide plate material under a certain condition, and the surface is covered with a mirror surface or a light diffusion reflection plate, and the other surface of the light guide plate (light output The present invention relates to a panel backlight in which a plurality of light diffusing plates are disposed on a (surface).
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.
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
を複数枚、通常は２枚重ねて用いる。このように複数枚
の光拡散板を重ねて用いることにより、充分な輝度を持
つバックライトとすることができる。ここで用いる光拡
散板は、例えば少なくとも一方表面を、他の面より荒
く、例えばエンボス加工、サンドブラスト加工、ガラス
ビーズを含んだ透明樹脂塗料を塗布するなどして粗面と
したものであり、より荒い面を上面（外面）として重ね
合わせて用いる。FIG. 1 is a perspective view of one embodiment of the present invention, and FIG.
Is a sectional view of the same. In the figure, reference numeral 1 denotes a light guide plate, which may be any substance that can efficiently transmit light, 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, a plurality of, usually two, light diffusion plates are used. By using a plurality of light diffusing plates in such a manner, a backlight having a sufficient luminance can be obtained. The light diffusion plate used here is, for example, at least one surface rougher than the other surface, for example, embossing, sand blasting, or the like having a rough surface by applying a transparent resin paint containing glass beads. The rough surface is used as an upper surface (outer surface).
導光板に施す光散乱物質６は、導光板の材質に比較し
て高屈折率を持ち、かつ拡散反射率が大きい顔料を含ん
だ塗料、印刷インキ等である。これらをスクリーン印刷
等の方法で導光板面上に後述するように一定の条件に従
ってドット状に印刷する。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、導光板の端部に光が入光
するための間隙（スリット）を有する光拡散反射器６
で、光源を、光源面とある幅の間隙をもたせた状態で光
源が覆われており、導光板の少なくとも一端面部に近接
してその中心軸が導光板の端面とほぼ平行となるように
設置される。この線状光源は、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、少なくともその均一発光部分の
長さは、近接する導光板の端部の長さと等しいかそれ以
内の長さで、導光板の端部の長さの3/4程度あれば良
い、又、線状光源の全長も、同く導光板の端部の長さと
等しいかそれ以内の長さであることが好ましい。The light scattering substance 6 applied to the light guide plate is a paint, a printing ink, or the like containing a pigment having a higher refractive index than the material of the light guide plate and having a large diffuse reflectance. These are printed in dot form on the light guide plate surface by a method such as screen printing according to certain conditions as described later. The mirror surface or the light diffusion reflection plate 3 is arranged so as to cover almost the entire surface of the light guide plate coated with the light scattering substance. Reference numeral 4 denotes a linear light source, and a light diffusion reflector 6 having a gap (slit) for allowing light to enter the end of the light guide plate.
The light source is installed so that the light source is covered with a gap of a certain width from the light source surface, and the central axis is close to at least one end surface of the light guide plate and is substantially parallel to the end surface of the light guide plate. Is done. The linear light source may be a fluorescent tube, a tungsten incandescent tube, an optical rod, an LED array, or the like, but a fluorescent tube is preferable, and at least the length of the uniform light emitting portion is equal to the length of the end of the adjacent light guide plate. The length of the light guide plate should be about 3/4 of the length of the end of the light guide plate, and the total length of the linear light source should also be equal to or less than the length of the end of the light guide plate. Is preferable.
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
が、この際、本発明では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, particularly a liquid crystal panel. At this time, the present invention preferably has the following structure.
１）本発明で用いる線状光源には、導光板端面に光が入
光するための間隙（スリット）を持つ反射器を設置す
る。又線状光源の表面とそれに相対した反射器の面との
間隙幅は、0.5〜5mm程度で良く、好ましくは１〜2mmで
ある。反射器の性能としては、拡散反射率が大きければ
大きいほど良いが、少なくとも85％以上反射率を持つこ
とが好ましい。このような反射器付き線状光源と、後述
する光拡散物質のドットパターンの相互作用により、線
状光源の口金、電極部の無発光部及び電極付近の経時黒
化現象の影響を除去できる。1) In the linear light source used in the present invention, a reflector having a gap (slit) for light to enter the light guide plate end face is installed. The gap width between the surface of the linear light source and the surface of the reflector facing it may be about 0.5 to 5 mm, preferably 1 to 2 mm. As for the performance of the reflector, the larger the diffuse reflectance is, the better, but it is preferable that the reflector has a reflectance of at least 85% or more. The interaction between the linear light source with the reflector and the dot pattern of the light diffusing substance, which will be described later, makes it possible to eliminate the influence of the base of the linear light source, the non-light-emitting portion of the electrode portion, and the temporal blackening near the electrode.
２）本発明の導光板に施す光拡散物質は、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0.5mm〜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。2) The light diffusing substance applied to the light guide plate of the present invention is formed in a dot shape, that is, a dot shape. However, the shape of the dot is not particularly limited, and is formed by a circle, a square, or an intersection line. Either is acceptable. These are applied on intersections (grids) of orthogonal lines having a certain interval imagined on the light guide plate, and the interval between the orthogonal lines is 0.5 mm to 3 mm, more preferably 0.8 to 2 mm.
Is appropriately selected according to the thickness of the light guide plate.
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
80％〜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、その被覆率が後述する条件で増加す
る状態とすることが好ましい。尚、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 light-diffusing material is coated at a coverage of 1% to 50% in the vicinity of the linear light source on the light guide plate surface and at a farthest part from the light source.
It is preferably 80% to 100%, and as the distance from the light source increases, it is preferable to increase the coverage under the conditions described later. Here, the covering ratio means a ratio of a covering area of the light scattering substance applied per unit area of the light guide plate surface.
本発明では、前記した光散乱物質の被覆率の増加は、
線状光源側からの距離に対して1.7次〜３次に比例して
増加した導光板を用いることが好ましく、更に好ましく
は線状光源側の被覆地点から導光板面のある地点までの
距離（Ｘ）に対して、その部分の被覆率（Ｙ）が次の
式、即ち、Ｙ＝aXn、又は、Ｙ＝axを満足する状態で増
加する部分を持つようにすることである。前記した条件
を満足する部分は、導光板の、線状光源の両端部の近傍
以外の部分である。ここでｎは1.7〜３、ａは定数で、
導光板の厚さ、発光面積の大きさにより異なるが前記被
覆率が光源部近傍で１％〜50％、光源から最遠部で80％
〜100％である関係式の回帰から求められる値である。In the present invention, the increase in the coverage of the light-scattering substance is
It is preferable to use a light guide plate that increases in proportion to the order of 1.7 to 3 with respect to the distance from the linear light source side, and more preferably the distance from the coating point on the linear light source side to a point on the light guide plate surface ( relative to X), wherein coverage (Y) is the next of the parts, i.e., Y = aX n, or is to have a portion that increases in a state that satisfies Y = a x. The portions satisfying the above conditions are portions of the light guide plate other than the vicinity of both ends of the linear light source. Where n is 1.7-3, a is a constant,
Depending on the thickness of the light guide plate and the size of the light emitting area, the coverage is 1% to 50% near the light source part and 80% at the farthest part from the light source.
This is a value obtained from regression of a relational expression of 100100%.
３）更に、本発明では、導光板面上で、線状光源の長手
方向の中心軸と、線状光源のほぼ中央部で垂直に交差す
る線分（Ａ）（図３においてa,b,dを結ぶ線分）上で上
記２）で述べた条件を満足し、前記線分（Ａ）から、前
記線状光源の中心軸と平行な方向での任意の距離
（Ｘ′）における光拡散物質の被覆率（Ｙ）が距離
（Ｘ′）に対して、次の式、即ち、Ｙ＝ａ′Ｘ′ｎ、又
は、Ｙ＝ａ′ｘ′を満足する状態で増加することであ
る。ここで、ｎ、ａ′は前記したと同種の値である。こ
の際、被覆率（Ｙ）は、導光板の全ての面において上記
した関係を満足する必要はなく、線状光源からある距離
までの範囲の面上で上記した関係を満足する値を採れば
良い。3) Further, according to the present invention, on the light guide plate surface, a line segment (A) that vertically intersects the central axis in the longitudinal direction of the linear light source and substantially at the center of the linear light source (a, b, d) which satisfies the condition described in the above 2) on the line segment (d) and at a given distance (X ′) from the line segment (A) in a direction parallel to the central axis of the linear light source. coverage of materials 'to, the following equation, i.e., Y = a'X (Y) is the distance (X)' n, or is to be increased in a state that satisfies Y = a 'x'. Here, n and a 'are the same values as described above. At this time, the coverage (Y) does not need to satisfy the above-described relationship on all surfaces of the light guide plate, and a value that satisfies the above-described relationship on a surface within a range from the linear light source to a certain distance is used. good.
図９に、本発明と、光拡散物質を均等に導光板の面に被
覆した例との、光源側からの距離と輝度との関係を示し
た。この結果は、本発明は、面全体で略均一な輝度が得
られることを示す。FIG. 9 shows the relationship between the distance from the light source side and the luminance of the present invention and an example in which the light diffusing substance is uniformly coated on the surface of the light guide plate. This result indicates that the present invention can obtain a substantially uniform luminance over the entire surface.
図10に光源側からの距離に比例して被覆率が増加する際
の次数による輝度分布（相対値）の相違を示した。図中
の曲線a,b,cは夫々１次、1.7次、３次の被覆率の変化を
示し、これらの輝度分布に対応した分布を夫々A,B,Cで
示した。この図より、輝度分布をフラットな状態にする
には、被覆率を1.7〜３次に比例して増加させることが
好ましいことが判る。FIG. 10 shows the difference in luminance distribution (relative value) depending on the order when the coverage increases in proportion to the distance from the light source side. Curves a, b, and c in the figure show changes in the primary, 1.7-, and tertiary coverages, respectively, and distributions corresponding to these luminance distributions are shown by A, B, and C, respectively. From this figure, it can be seen that in order to make the luminance distribution flat, it is preferable to increase the coverage in proportion to 1.7 to 3 orders.
図11に起点と終点の被覆率による輝度分布の変化を示し
た。図中ｄは起点が30％、終点が80％であり、この時の
輝度分布をＤで示した。同様に起点が50％、終点が100
％の場合をｅで示し、この時の輝度分布をＥで示した。FIG. 11 shows a change in the luminance distribution depending on the coverage at the start point and the end point. In the figure, d indicates a starting point of 30% and an ending point of 80%, and the luminance distribution at this time is indicated by D. Similarly, the starting point is 50% and the ending point is 100
%, And the luminance distribution at this time is indicated by E.
この結果、輝度分布をフラットにするには、起点が30
〜50％、終点が80〜100％の範囲であることが好ましい
ことが判る。As a result, to make the luminance distribution flat, the starting point is 30
It is understood that it is preferable that the end point is in the range of 80 to 100%.
本発明は、光拡散板の上面に液晶パネルなどの光表示
パネルを設置して使用される。The present invention is used by installing an optical display panel such as a liquid crystal panel on the upper surface of a light diffusion plate.
［発明の効果］ 本発明は比較的小型で、輝度分布が均一で充分な輝度
を得られるバックライトとして使用可能である。[Effects of the Invention] The present invention can be used as a backlight that is relatively small, has a uniform luminance distribution, and can obtain sufficient luminance.
［比較例及び実施例］ 次に比較例及び実施例で本発明を更に詳述する。まず
比較例として次の方法で試験した。Comparative Examples and Examples Next, the present invention will be described in more detail with reference to Comparative Examples and Examples. First, a comparative example was tested by the following method.
図１に示すような厚さ3mmの長方形導光板（250mm×15
0mm）の短手の端部に、その端部長と同じ長さで直径5.8
mmの太さの冷陰極蛍光管（ハリソン電機株式会社製5.8m
mφノーマル管）を配置し、その管の外周を1mmの隙間を
おいて、導光板に接する部分に3mmのスリットを持つ、
特殊樹脂塗料を塗布した筒型アルミ反射器（拡散反射率
85％以上）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。A rectangular light guide plate with a thickness of 3 mm (250 mm x 15 mm) as shown in Fig. 1
0mm) and the same length as the length of the end
mm cold cathode fluorescent tube (5.8 m, manufactured by Harrison Electric Co., Ltd.)
mφ normal tube), with a 1 mm gap around the tube, and a 3 mm slit at the part that contacts the light guide plate.
Cylindrical aluminum reflector coated with special resin paint (diffuse reflectance
(85% or more), and the light emitted from the slit was arranged so as to enter the light guide plate from the end of the light guide plate.
光拡散板として、両面に光拡散能を付与した厚さ100
μｍのポリエステルシート１枚を用いた。As a light diffusion plate, thickness 100 with light diffusion ability on both sides
One μm polyester sheet was used.
一方、導光板面上に被覆する光拡散物質は、図３に示
した円形のドットパターンをスクリーン印刷したもので
あり、スクリーン版下は、CADにより下記の条件で作成
して用いた。光拡散物質の被覆率が、Ｘ値の最小の地点
（即ち図3a点付近）で３％、最大の地点（即ち図3d点付
近）で70％、その中間ではこれらの比率がX2に比例した
値となるように作図した。On the other hand, the light diffusing substance coated on the light guide plate surface was obtained by screen-printing the circular dot pattern shown in FIG. 3, and the screen plate was prepared and used by CAD under the following conditions. Coverage of the light diffusion material is 3% with a minimum at the point of X value (i.e. Figure 3a near point), at most 70% of the point (i.e. Figure 3d around point), proportional in its middle these ratio X 2 The plot was made so that the obtained value was obtained.
又、線状光源と平行に配置されるＸ′の方向には、Ｘが
０から導光板長手端面のほぼ中間まで（即ち図中ｂ点）
の間が、Ｘ′＝０（即ちａ〜ｂ間の各点）及びＸ′の最
大（即ちｃ〜ｂ′間の各点）の被覆率を基準に、Ｘ′値
の３乗に比例した変化率で決定される被覆率となるよう
に作図した。Further, in the direction of X 'arranged parallel to the linear light source, X is from 0 to almost the middle of the longitudinal end face of the light guide plate (that is, point b in the figure).
Is proportional to the cube of the X 'value, based on the coverage of X' = 0 (i.e., each point between a and b) and the maximum of X '(i.e., each point between c and b'). Drawing was performed so that the coverage rate was determined by the change rate.
図３上のｃ点の被覆率は、導光板の厚さ、大きさ、冷
陰極管の種類により１％〜50％の間で任意に選ばれる値
であり、本例では８％とした。The coverage at the point c in FIG. 3 is a value arbitrarily selected from 1% to 50% depending on the thickness and size of the light guide plate and the type of the cold cathode fluorescent lamp, and is 8% in this example.
冷陰極管に、インバータより30KHzの交番電圧をかけ
て駆動させたときの面輝度分布を、輝度計（トプコンBM
−８）により測定しグラフ化したものを図４（比較１）
に示した。図から、極めて平坦な輝度分布を持つ面光源
であることが判る。The brightness distribution (Topcon BM) is shown by the surface brightness distribution when the cold cathode tube is driven by applying an alternating voltage of 30 KHz from the inverter.
Fig. 4 (Comparative 1) is a graph obtained by measuring according to -8).
It was shown to. From the figure, it can be seen that the surface light source has an extremely flat luminance distribution.
又、冷陰極管の両端約13mmを黒色塗料で遮蔽した以外
は上記例と同一の装置、条件で操作し、輝度分布を測定
した結果を図５（比較２）に示した。上記２例について
は、差が見られず、冷陰極管の経時劣化と同条件での駆
動による輝度分布の変化は無いことが判る。又、筒型ア
ルミ反射器のギャップを0.3mmにした以外は上記例と同
一の装置、条件で操作し、輝度分布を測定した結果を図
６（比較３）に示した。FIG. 5 (Comparative 2) shows the result of measuring the luminance distribution by operating under the same apparatus and conditions as in the above example except that both ends of the cold cathode tube were shielded by black paint at about 13 mm. There is no difference between the above two examples, and it can be seen that there is no change in the luminance distribution due to driving under the same conditions as the deterioration with time of the cold cathode tube. FIG. 6 (Comparative 3) shows the result of measuring the luminance distribution by operating under the same apparatus and conditions as in the above example except that the gap of the cylindrical aluminum reflector was set to 0.3 mm.
冷陰極管に近い部分でＸ′方向に輝度の差がみられる
ばかりでなく、全体として輝度の絶対値の低下がみられ
る。更に、光拡散物質のドットパターンの塗布時にドッ
ト分布をＹについては一様に配置した以外は上記例と同
一の装置、条件で操作し、輝度分布を測定した結果を図
７（比較４）に示した。この図から、冷陰極管に近い部
分で暗い縞模様の形成がみられた。Not only a difference in luminance in the X 'direction is observed in a portion near the cold cathode tube, but also a decrease in the absolute value of luminance as a whole is observed. FIG. 7 (Comparative 4) shows the result of operating the same apparatus and conditions as in the above example except that the dot distribution was uniformly arranged for Y when applying the dot pattern of the light diffusing substance. Indicated. From this figure, formation of a dark stripe pattern near the cold cathode tube was observed.
上記例の光拡散板として用いた拡散シートを、片面を
他の面より荒い粗面とした厚さ200μｍのポカーボネー
ト２枚を、その粗面を光放出側（上面）として２枚重ね
て用いた（図１の２）以外は比較例１と同一の装置、条
件で操作し、輝度分布を測定した結果（例１）、輝度分
布の形態は比較１の場合と略同一であったが輝度が向上
した。尚、これらの例で用いた輝度分布のグラフは、図
８に示した導光板上の60の測定点での輝度をコンピュー
タに記憶させ目視的にグラフ化させたもので、直交する
直線で示される交点が60点の平均値を表すもので、ジグ
ザグ線で結ばれる各点が平均値よりの偏りを表す。輝度
の最大値、最小値、平均値（Cd/cm2）は次のとおりであ
る。The diffusion sheet used as the light diffusion plate of the above example was used by stacking two 200 μm-thick pocarbonates having one surface rougher than the other surface, and using the rough surface as the light emission side (upper surface). The luminance distribution was measured using the same apparatus and conditions as in Comparative Example 1 except for (2 in FIG. 1), and the conditions were the same (Comparative Example 1). Improved. The graphs of the luminance distribution used in these examples are obtained by storing the luminance at 60 measurement points on the light guide plate shown in FIG. 8 in a computer and visually forming a graph, and are shown by orthogonal straight lines. The intersection points represent the average value of 60 points, and each point connected by a zigzag line represents a deviation from the average value. The maximum value, minimum value, and average value (Cd / cm 2 ) of the luminance are as follows.
最大値 最小値 平均値 比較１ 182.000 175,000 178,075 比較２ 182,000 174,000 178,150 比較３ 178,500 135,000 161,958 比較４ 240,000 143,500 171,375 例 １ 205,660 197,800 201,730 Maximum value Minimum value Average value Comparison 1 182.000 175,000 178,075 Comparison 2 182,000 174,000 178,150 Comparison 3 178,500 135,000 161,958 Comparison 4 240,000 143,500 171,375 Example 1 205,660 197,800 201,730
図１は、本発明の一実施態様のバックライトの斜視図、
図２は同じく断面図である。図中１は導光板、２は光拡
散板、３は鏡面反射板又は光拡散板、４は蛍光管、５は
光拡散反射器、６は光散乱物質である。図３は、導光板
に塗布した光光散乱物質の分布状態を示す図である。図
４〜図７は本発明の比較例で得た輝度分布を示す図であ
る。尚、同図面右側が入光部である。図８は輝度の測定
点を示す図である。 図９は本発明で用いる導光板と、均一に光拡散物質を施
した導光板との光透過状態を示す。 図中１は本発明の、２は比較として用いた例の状態を示
す。 図10は、光原からの距離に比例して被覆率が増加する際
の次数による輝度分布の相違を示す。図11は、起点と終
点の被覆率による輝度分布の変化を示す。FIG. 1 is a perspective view of a backlight according to an embodiment of the present invention,
FIG. 2 is a sectional view of the same. In the figure, 1 is a light guide plate, 2 is a light diffusion plate, 3 is a specular reflection plate or light diffusion plate, 4 is a fluorescent tube, 5 is a light diffusion reflector, and 6 is a light scattering substance. FIG. 3 is a view showing a distribution state of the light-scattering substance applied to the light guide plate. 4 to 7 are diagrams showing luminance distributions obtained in a comparative example of the present invention. The right side of FIG. FIG. 8 is a diagram showing measurement points of luminance. FIG. 9 shows a light transmission state of a light guide plate used in the present invention and a light guide plate uniformly coated with a light diffusing substance. In the drawing, reference numeral 1 denotes the state of the present invention, and 2 denotes the state of an example used for comparison. FIG. 10 shows a difference in luminance distribution depending on the order when the coverage increases in proportion to the distance from the light source. FIG. 11 shows a change in the luminance distribution depending on the coverage at the start point and the end point.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) G02F 1/1335 G09F 9/00 F21V 8/00──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 6 , DB name) G02F 1/1335 G09F 9/00 F21V 8/00
Claims (6)
側面端部に、これに近接した線状光源を有し、かつ、前
記導光板の一方の面に該導光板材料よりも屈折率が大な
る光拡散物質を、その被覆率が線状光源からの距離が大
になるにつれて大となるように被覆し、その面を鏡面反
射板又は光拡散反射板で覆い、導光板の他方の面（出光
面）に複数枚の光散乱板を配したパネル用バックライ
ト。At least one side end of a light guide plate made of a light-transmitting material has a linear light source close to the light guide plate, and one surface of the light guide plate has a refractive index higher than that of the light guide plate material. Is coated, so that its coverage increases as the distance from the linear light source increases, its surface is covered with a specular reflection plate or a light diffusion reflection plate, and the other side of the light guide plate. Panel backlight with multiple light scattering plates on the surface (light exit surface).
側の被覆地点からの距離（Ｘ）に対してＹ＝aXn（ｎ＝
1.7〜３）又はＹ＝aXの関数関係（ａは定数）を少なく
とも満足する部分を持つ状態にある特許請求の範囲１項
記載のバックライト。2. In the light guide plate, the coverage (Y) is Y = aX n (n = n ) with respect to the distance (X) from the coating point on the side of the linear light source.
1.7 to 3) or Y = a X functional relationship (a backlight of claims 1 wherein in a state with a portion at least satisfying the constant).
脂板を少なくとも１枚用い、該板のより粗面側を外側と
して配置した特許請求の範囲１又は２項記載のバックラ
イト。3. The backlight according to claim 1, wherein at least one transparent resin plate containing translucent beads is used as the light scattering plate, and the roughened surface side of the plate is disposed outside. .
側面端部に、これに近接した線状光源を有し、線状光源
の均一発光部分が、線状光源と相対する導光板の端部長
に等しいかそれ以下の長さであり、線状光源は、導光板
端面に光が入射するための間隙（スリット）を持つ光拡
散反射器で、光源表面と光拡散反射器面とが間隙を持つ
状態で覆われており、導光板の一方の面に該導光板材料
よりも屈折率が大なる光拡散物質を、導光板面上で、線
状光源の長手方向の中心軸と線状光源のほぼ中央部で垂
直に交差する線分（Ａ）上における被覆率（Ｙ）が、線
状光源側の被覆地点からの距離（Ｘ）に対してＹ＝aXn
（ｎ＝1.7〜３）又はＹ＝aXの関数関係（ａは定数）を
満足する状態で、かつ前記線分（Ａ）から、前記線状光
源の中心軸と平行な方向での任意の距離（Ｘ′）に対し
てＹ＝ａ′Ｘ′ｎ（ｎ＝1.7〜３）又はＹ＝ａ′Ｘ′の
関数関係（ａ′は定数）を満足する部分を持つようにド
ット状に被覆し、その面を鏡面反射板又は光拡散反射板
で覆い、導光板の他方の面（出光面）に複数枚の光散乱
板を配したパネル用バックライト。4. A light guide plate made of a translucent material has a linear light source adjacent to at least one side end of the light guide plate, and a uniform light emitting portion of the linear light source is provided on a light guide plate facing the linear light source. The linear light source is a light diffusion reflector having a gap (slit) for light to enter the end surface of the light guide plate, and the light source surface and the light diffusion reflector surface have a length equal to or less than the end length. A light diffusing substance having a refractive index larger than that of the light guide plate material is covered on one surface of the light guide plate with a gap, and a central axis and a line in the longitudinal direction of the linear light source on the light guide plate surface. The coverage (Y) on a line segment (A) that intersects vertically at substantially the center of the linear light source is represented by Y = aX n with respect to the distance (X) from the linear light source side covering point.
(N = 1.7-3) or a condition satisfying the functional relationship of Y = a X (a is a constant), and an arbitrary value in the direction parallel to the central axis of the linear light source from the line segment (A). distance (X ') relative to the Y = a'X' n (n = 1.7~3) or Y = a functional relationship 'X' (a 'is a constant) coated in dots to have a portion which satisfies the A backlight for a panel, the surface of which is covered with a specular reflection plate or a light diffusion reflection plate, and a plurality of light scattering plates are arranged on the other surface (light output surface) of the light guide plate.
脂板を少なくとも１枚用い、該板のより粗面側を外側と
して配置した特許請求の範囲４項記載のバックライト。5. The backlight according to claim 4, wherein at least one transparent resin plate containing translucent beads is used as the light scattering plate, and the rougher side of the plate is disposed outside.
との間隙が0.5〜5mmである特許請求の範囲４又は５項記
載のバックライト。6. The backlight according to claim 4, wherein a gap between the light diffusion reflector surface covering the light source surface and the light source surface is 0.5 to 5 mm.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2172809A JP2794909B2 (en) | 1990-07-02 | 1990-07-02 | Backlight for panel |
| US07/655,520 US5093765A (en) | 1990-02-16 | 1991-02-14 | Back lighting device for a panel |
| DE69122635T DE69122635T2 (en) | 1990-02-16 | 1991-02-15 | Backlighting device for a display panel |
| EP91102200A EP0442529B1 (en) | 1990-02-16 | 1991-02-15 | Back lighting device for a panel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2172809A JP2794909B2 (en) | 1990-07-02 | 1990-07-02 | Backlight for panel |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7157642A Division JP3011059B2 (en) | 1995-06-23 | 1995-06-23 | Backlight |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0462519A JPH0462519A (en) | 1992-02-27 |
| JP2794909B2 true JP2794909B2 (en) | 1998-09-10 |
Family
ID=15948777
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2172809A Expired - Fee Related JP2794909B2 (en) | 1990-02-16 | 1990-07-02 | Backlight for panel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2794909B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3429387B2 (en) * | 1995-03-31 | 2003-07-22 | 株式会社エンプラス | Sidelight type surface light source device |
| JPH0981049A (en) * | 1995-09-12 | 1997-03-28 | Enplas Corp | Side light type surface light source device |
| EP1754958A1 (en) | 1995-12-13 | 2007-02-21 | Matsushita Electric Industrial Co., Ltd. | Ultrasonic flowmeter and ultrasonic transducer |
| US6435686B1 (en) | 1999-02-26 | 2002-08-20 | The Ohtsu Tire & Rubber Co., Ltd. | Light conducting plate for a back lighting device and back lighting device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54122786U (en) * | 1978-02-16 | 1979-08-28 | ||
| JPS5981683A (en) * | 1982-11-02 | 1984-05-11 | 株式会社東芝 | Liquid crystal display |
| JPS61166585A (en) * | 1985-01-18 | 1986-07-28 | 三菱レイヨン・エンジニアリング株式会社 | Liquid crystal display unit |
-
1990
- 1990-07-02 JP JP2172809A patent/JP2794909B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0462519A (en) | 1992-02-27 |
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|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |