JP2540303Y2

JP2540303Y2 - Surface light source device

Info

Publication number: JP2540303Y2
Application number: JP1990063983U
Authority: JP
Inventors: 和明横山
Original assignee: Enplas Corp
Current assignee: Enplas Corp
Priority date: 1990-06-19
Filing date: 1990-06-19
Publication date: 1997-07-02
Anticipated expiration: 2005-06-19
Also published as: JPH0422780U

Description

【考案の詳細な説明】［産業上の利用分野］本考案は、液晶装置のバックライト等に利用される導
光体を用いた面光源装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a surface light source device using a light guide used for a backlight or the like of a liquid crystal device.

［従来の技術］従来の導光体を用いた面光源装置は、第３図、第４図
に示すように冷陰極管等の直線状の光源１と、この光源
１に入射端面2aを近傍配置した透明体よりなる導光体２
と、導光体２の表面に配置した拡散板３と、導光体２の
裏面に形成した反射面４とよりなり、そして光源１から
の光は、入射端面2aより導光体２内へ入り、上下の面で
順次反射されながら入射側からそれと反射側へ伝達され
て行く。このように導光体２内を伝達されて行く光の一
部は、導光体２の表面より外に出、拡散板３を通って拡
散光となる。この拡散板３よりの拡散光は、入射端面2a
近くで明るく入射端面2aより遠ざかる程輝度が減少し暗
くなる。その欠点を除去するために第４図に示すような
入射端面2a付近が面積において疎で入射端面2aから遠く
なるにつれ密になるパターンを導光体２に乳白色の印刷
を施す等の方法によって、拡散板３よりの拡散光の輝度
が一様になるようにしている。[Prior Art] A conventional surface light source device using a light guide includes a linear light source 1 such as a cold-cathode tube as shown in FIGS. Light guide 2 composed of a transparent body arranged
And a diffusing plate 3 disposed on the surface of the light guide 2 and a reflection surface 4 formed on the back surface of the light guide 2. Light from the light source 1 enters the light guide 2 from the incident end face 2 a. The incident light is transmitted from the incident side to the reflection side while being sequentially reflected by the upper and lower surfaces. A part of the light transmitted in the light guide 2 in this manner exits from the surface of the light guide 2 and passes through the diffusion plate 3 to become diffused light. The diffused light from the diffuser 3 is incident on the incident end face 2a.
The brightness decreases nearer and becomes farther from the incident end face 2a, and the brightness decreases and darkens. In order to remove the drawback, a pattern in which the area near the incident end face 2a is sparse in area and becomes denser as the distance from the incident end face 2a increases as shown in FIG. The brightness of the diffused light from the diffuser plate 3 is made uniform.

［考案が解決しようとする課題］以上述べたような面光源装置は、スペースの制約上拡
散板発光面の寸法（入射端面2aの長さ）と光源１の全長
を同じにしなければならないことがある。このような場
合、光源１の両端の電極部1aの影響により、入射端面2a
の両端に近いところ（第４図に符号Ａにて示す付近）の
輝度が低下するという欠点があった。[Problem to be Solved by the Invention] In the surface light source device as described above, the size of the light emitting surface of the diffusion plate (the length of the incident end face 2a) and the total length of the light source 1 must be the same due to space restrictions. is there. In such a case, the incident end face 2a is affected by the electrode portions 1a at both ends of the light source 1.
There is a disadvantage that the luminance near the both ends (near the symbol A in FIG. 4) decreases.

本考案の目的は、上記の部分を含めて拡散板面全体が
均一の輝度になるようにした面光源装置を提供すること
にある。SUMMARY OF THE INVENTION It is an object of the present invention to provide a surface light source device in which the entire surface of a diffusion plate including the above-described portion has uniform luminance.

［課題を解決するための手段］本考案の面光源装置は、冷陰極管等の線状の光源と、
入射側端面を光源に近接させて配置した透明な材料より
なる導光体と、導光体の表面に配置した拡散板と、導光
体の裏面に設けた反射面とよりなり、導光体の入射端面
の長さを線状の光源の長さとほぼ等しくすると共に、導
光体の表面或は裏面の、光源の電極部近傍を除く部分に
は、入射端面側から他の端面に向けて面積が徐々に大き
くなるように相似形の拡散作用を有する拡散パターンを
複数形成し、また光源の電極部近傍には、光源の電極部
近傍を除く部分に形成された拡散パターンのうち最小の
拡散パターンと同一或いはそれよりも面積が小さい相似
形の拡散パターンを高密度に多数形成することで、入射
端面近傍における光源の長手方向の中央部近傍の領域よ
りも電極部近傍の領域の方が拡散パターントータルの面
積のその領域の面積に対する比率が高くなるようにした
ものである。本考案の面光源装置は、上記のように形成
された拡散作用をする拡散パターンによって入射端面側
からの他端両側にかけて均一な輝度分布となし得ると共
に光源の電極部近くの暗くなる部分においても他と同じ
輝度になし得る。[Means for Solving the Problems] The surface light source device of the present invention includes a linear light source such as a cold cathode tube,
A light guide made of a transparent material whose entrance side end face is arranged close to the light source, a diffusion plate arranged on the surface of the light guide, and a reflection surface provided on the back surface of the light guide; The length of the incident end face of the light guide is substantially equal to the length of the linear light source, and the surface or the back surface of the light guide, except for the vicinity of the electrode portion of the light source, is provided from the incident end face side to the other end face. A plurality of diffusion patterns having a similar diffusion action are formed so that the area gradually increases, and the smallest diffusion pattern is formed in the vicinity of the electrode portion of the light source except for the vicinity of the electrode portion of the light source. By forming a large number of similar diffusion patterns having the same area or a smaller area than the pattern at a high density, the area near the electrode portion is more diffused than the area near the longitudinal center of the light source near the incident end face. Surface of the area of the total pattern area Is obtained as the ratio is higher for. The surface light source device of the present invention can achieve a uniform luminance distribution from the incident end face side to both ends from the incident end face side by the diffusion pattern having the diffusion action formed as described above, and also in a dark part near the electrode part of the light source. The same brightness can be achieved.

［実施例］次に本考案の面光源装置の一実施例を図面にもとづい
て説明する。Next, an embodiment of the surface light source device of the present invention will be described with reference to the drawings.

第１図は、本考案の第１の実施例の断面図、第２図は
導光体のパターンを示す図である。この第１の実施例
は、光源１と、導光体２と、拡散板３と、反射面４とで
構成されている。又導光体２には第２図に示されている
ように、表面上或いは裏面上もしくは裏表両面上に乳白
色の印刷パターン等の拡散作用を有するパターン５が設
けられている。この印刷パターンは、中央部から光源よ
り遠い側に向けて各パターンが次第に大きくなり又は疎
から次第に密になった第４図の従来例と同様のものであ
る。しかし入射端面2aに近い部分は前記の光源の電極部
1aに近い部分においてパターン６を密にしてある。これ
によって従来例と同様に全体として均一な輝度が得られ
ると共に光量の不足する両端部分においても光量の増加
をはかることによって装置を大きくすることなしに拡散
板面全体にわたって均一な輝度分布の照明装置になし得
る。FIG. 1 is a sectional view of a first embodiment of the present invention, and FIG. 2 is a view showing a pattern of a light guide. This first embodiment includes a light source 1, a light guide 2, a diffusion plate 3, and a reflection surface 4. As shown in FIG. 2, the light guide 2 is provided with a pattern 5 having a diffusing action such as a milky white print pattern on the front surface, the back surface, or both the front and back surfaces. This print pattern is the same as the conventional example in FIG. 4 in which each pattern is gradually increased from the center toward the side farther from the light source, or gradually becomes denser from sparse. However, the portion near the incident end face 2a is the electrode part of the light source described above.
The pattern 6 is made dense in a portion near 1a. This makes it possible to obtain a uniform luminance as a whole as in the conventional example, and to increase the amount of light even at both end portions where the amount of light is insufficient. Can be done.

［考案の効果］本考案の面光源装置は、光源の長さ（電極部を含め）
とほぼ同じ長さの入射端面として光源の面積に比較して
小型の装置で、しかも拡散面全面にわたって均一輝度に
なし得る。[Effect of the Invention] The surface light source device of the present invention has a light source length (including an electrode portion).
As the incident end face having substantially the same length as that of the light source, a device smaller than the area of the light source and having uniform brightness over the entire diffusion surface can be obtained.

【図面の簡単な説明】[Brief description of the drawings]

第１図，第２図は本考案の第１の実施例を示す図、第３
図，第４図は従来の導光体を用いた面光源装置の図であ
る。１…光源、２…導光体、３…拡散板４…反射板 5,6…拡散作用を有するパターン1 and 2 show a first embodiment of the present invention.
FIG. 4 is a diagram showing a surface light source device using a conventional light guide. DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Light guide, 3 ... Diffusion plate 4 ... Reflection plate 5, 6 ... Pattern which has a diffusion effect

Claims

(57)【実用新案登録請求の範囲】(57) [Scope of request for utility model registration]

【請求項１】両端に電極部を有する線状の光源と、入射
端面を前記光源に近接配置した導光体と、前記導光体の
表面に設けられた拡散板と、前記導光体の裏面に設けら
れた反射面とを有し、前記導光体の入射端面の長さを前
記線状の光源の長さとほぼ等しくすると共に、前記導光
体の表面或いは裏面の前記光源の電極部近傍を除く部分
には、前記入射端面側から他端側に向かうに従って面積
が徐々に大きくなる夫々相似形の拡散作用を有する拡散
パターンを複数形成し、更に前記導光体の表面或いは裏
面の前記電極部近傍部分には、前記拡散パターンのうち
最小の拡散パターンと同一或いはそれよりも面積が小さ
い相似形の拡散パターンを高密度に多数形成して、前記
入射端面近傍において前記電極部近傍の領域の方が前記
光源の長手方向の中央部近傍の領域よりも拡散パターン
トータルの面積のその領域の面積に対する比率が高くな
るようにしたことを特徴とする面光源装置。1. A linear light source having electrode portions at both ends, a light guide having an incident end face disposed close to the light source, a diffusion plate provided on a surface of the light guide, A reflecting surface provided on the back surface, the length of the incident end face of the light guide is substantially equal to the length of the linear light source, and the electrode portion of the light source on the front surface or the back surface of the light guide. Except for the vicinity, a plurality of diffusion patterns each having a similar diffusion action whose area gradually increases from the incident end face side toward the other end side are formed, and further, the light guide body has a front surface or a back surface. In the vicinity of the electrode portion, a large number of similar diffusion patterns having the same area or a smaller area than the smallest diffusion pattern among the diffusion patterns are formed at a high density, and a region near the electrode portion near the incident end face is formed. Is longer in the longitudinal direction of the light source The surface light source device central section than the region in the vicinity, characterized in that as the ratio becomes higher with respect to the area of the region of the area of the diffusion pattern total.