JPS63168604A - Planar light source for liquid crystal display device - Google Patents
Planar light source for liquid crystal display deviceInfo
- Publication number
- JPS63168604A JPS63168604A JP62000378A JP37887A JPS63168604A JP S63168604 A JPS63168604 A JP S63168604A JP 62000378 A JP62000378 A JP 62000378A JP 37887 A JP37887 A JP 37887A JP S63168604 A JPS63168604 A JP S63168604A
- Authority
- JP
- Japan
- Prior art keywords
- plate
- light
- light source
- liquid crystal
- crystal display
- 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.)
- Granted
Links
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 16
- 239000000463 material Substances 0.000 claims description 4
- 210000002858 crystal cell Anatomy 0.000 claims description 2
- 238000000465 moulding Methods 0.000 abstract description 2
- 238000007788 roughening Methods 0.000 abstract description 2
- 230000005540 biological transmission Effects 0.000 abstract 5
- 238000005516 engineering process Methods 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
Landscapes
- Light Guides In General And Applications Therefor (AREA)
- Liquid Crystal (AREA)
- Non-Portable Lighting Devices Or Systems Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、透過形液晶表示装置の光源に好適な、比較的
小数の点光源を用いた効率の良い液晶表示装置用板状光
源に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an efficient plate light source for a liquid crystal display device using a relatively small number of point light sources, which is suitable as a light source for a transmissive liquid crystal display device.
透過形液晶表示装置の背後光源として、螢光ランプを用
いる場合が多いが、一般に表示用とは別の電源を必要と
し且つ表示素子自体より遥かに大きな電力を消費し、反
射板に工夫を凝らしても表示素子裏面で一様な照度を得
ることはかなり困難であるなどの問題があった。Fluorescent lamps are often used as the back light source for transmissive liquid crystal display devices, but they generally require a separate power source from the one used for display, consume far more power than the display element itself, and require ingenuity in the reflector. However, there are problems in that it is quite difficult to obtain uniform illuminance on the back surface of the display element.
また、例えば特開昭５９−１０９８５号には、樹脂で作
った板の中に、複数の発光素子を埋設し、板面を所謂艶
消しにして面光源とすることが開示されているが、透過
形液晶表示素子の光源として均一な面輝度を得るための
配慮に欠けていた。Furthermore, for example, JP-A-59-10985 discloses embedding a plurality of light emitting elements in a board made of resin and making the board surface matte to create a surface light source. There was a lack of consideration for obtaining uniform surface brightness as a light source for a transmissive liquid crystal display element.
光源面の輝度が不均一な場合には、輝度差の程度にもよ
るが、液晶表示を誤判読する事態も生ずる。If the brightness of the light source surface is non-uniform, depending on the degree of the brightness difference, a situation may occur where the liquid crystal display is misread.
本発明は、上記従来の技術が液晶表示素子裏面で一様な
照度を得難いという問題点を解決し、面発光の均一性の
高い透過形液晶表示装置用板状光源を提供することを目
的とする。The present invention aims to solve the problem that the above-mentioned conventional technology has difficulty in obtaining uniform illuminance on the back surface of a liquid crystal display element, and to provide a plate-shaped light source for a transmissive liquid crystal display device with high uniformity of surface emission. do.
Ｃ問題点を解決するための手段〕
上記問題点を解決するために本発明においては、透過形
液晶表示装置の光源となる板状光源を、透光性板の端部
に接して、透光性板材内部に光が入射するように点光源
を配設し、板の表面に、前記点光源からの距離に依存し
て粗さの程度を変えた粗面加工を施し、この板の更に背
後外側に反射面を密着させて反射板を配置することとし
た。Means for Solving Problem C] In order to solve the above problems, in the present invention, a plate-shaped light source serving as a light source of a transmissive liquid crystal display device is placed in contact with an end of a translucent plate. A point light source is arranged so that light enters the interior of the board, and the surface of the board is roughened with varying degrees of roughness depending on the distance from the point light source. We decided to place a reflective plate with the reflective surface in close contact with the outside.
〔作用］
点光源から放射された光は、透光性素材よりなる板（導
光板）の内部を透過して導かれて行くが、その過程であ
る程度ずつ板の表面から放射される。しかし、板の表面
が完全な平面の場合には、透光性の板の素材の屈折率は
必ず空気の屈折率よりは高いから、光源からある程度離
れると、光が板表面へ内部から入射する際の入射角が臨
界角より大きくなり、板内部へ全反射するようになり板
は光を導くだけとなる。[Operation] Light emitted from a point light source passes through the interior of a plate (light guide plate) made of a translucent material and is guided, but in the process, a certain amount of light is emitted from the surface of the plate. However, if the surface of the plate is completely flat, the refractive index of the transparent plate material is always higher than the refractive index of air, so if you move away from the light source to a certain extent, light will enter the plate surface from inside. When the incident angle becomes larger than the critical angle, the light is totally reflected inside the plate, and the plate only guides the light.
本発明によって表面を粗面にすると板内部で全反射を繰
り返すようなことはなくなり、しかも粗さの程度を、例
えば光源からの距離の略２乗に比例して激しくしである
から、板の表面から外部へ放射される光の割合も光源か
らの距離が遠い所はど大きくなる。板状光源の内部で光
の強さが完全に距離の２乗に逆比例して弱くなるわけで
はないが、本発明に沿って板の表面に粗面加工を施せば
、実験的に粗面にした板の全面から均一に光を放射させ
ることが出来るようになる。この板の片側の粗面に密着
して反射板の反射面が配置されているから、一旦板の背
後外部に出た光も直ちに反射されて板を透過して液晶セ
ル裏面の偏光板を照射する。By making the surface rough according to the present invention, repeated total reflection inside the board will not occur, and the degree of roughness can be increased in proportion to approximately the square of the distance from the light source, for example. The proportion of light emitted from the surface to the outside also increases as the distance from the light source increases. Although the intensity of light inside a plate-shaped light source does not completely weaken in inverse proportion to the square of the distance, if the surface of the plate is roughened in accordance with the present invention, the roughened surface can be experimentally This allows light to be emitted uniformly from the entire surface of the board. The reflective surface of the reflector is placed in close contact with the rough surface on one side of this plate, so any light that once exits the back of the plate is immediately reflected, passes through the plate, and illuminates the polarizing plate on the back of the liquid crystal cell. do.
第１図（ａ）は本発明一実施例の平面図、第１図（ｂ）
は其の側面図で、図中、１は２個の発光ダイオード（Ｌ
ＥＤ）をモールドしたものであり、板の両端部断面にそ
れぞれ２組ずつ取付けられている。２は透光性良好な素
材よりなり、光源直径とほぼ等しい厚さの導光板、３は
反射板である、導光板２の表面２ａには、導光板上の端
部断面からの位置に対して表面の粗さが第２図に示すよ
うに距離の２乗に比例して変化するように導光板モール
ド時の型表面を粗面化することなどにより粗面加工が施
しである。本実施例の作用は既に説明した通りである。FIG. 1(a) is a plan view of one embodiment of the present invention, FIG. 1(b)
is its side view, and in the figure, 1 is two light emitting diodes (L
ED), and two sets are attached to each end cross section of the plate. 2 is a light guide plate made of a material with good translucency and has a thickness almost equal to the diameter of the light source; 3 is a reflection plate; on the surface 2a of the light guide plate 2, there are The surface is roughened by roughening the surface of the mold when molding the light guide plate so that the surface roughness changes in proportion to the square of the distance as shown in FIG. The operation of this embodiment is as already explained.
本発明者の試作、実験結果によれば、ＬＥＤの掻く近く
で多少輝度の低い個所が生じたが、その他の個所では輝
度の均一性は非常に良好であった。According to the experimental results of the inventor's trial production, although there were some areas where the brightness was somewhat low near the LED, the uniformity of the brightness was very good in other areas.
上記実施例においては、導光板２の反射板３側のみ粗面
化したが、要求特性によっては導光板２の両面を粗面化
しても良い、また点光源としては、発光ダイオードの代
りに小型白熱電球（電球）を使用することも出来る。In the above embodiment, only the reflection plate 3 side of the light guide plate 2 is roughened, but depending on the required characteristics, both sides of the light guide plate 2 may be roughened. Also, as a point light source, a small light emitting diode may be used instead of a light emitting diode. Incandescent light bulbs (light bulbs) can also be used.
なお、ＬＥＤを多数平面上に一様に分布配置し其の上に
更に光を散乱させるために表面を粗面化した透光性拡散
板を配置するなどすれば、均一な輝度で非常に明るく発
光する板状光源が得られるが、このような構成の光源は
、現在のＬＥＤの価格では、一般向けとしては高価にな
り過ぎ、また実用上からもそれほど高輝度にする必要も
ない。In addition, if you arrange a large number of LEDs uniformly on a flat surface and place a translucent diffuser plate with a roughened surface on top of it to further scatter the light, it will be very bright with uniform brightness. Although a plate-shaped light source that emits light can be obtained, a light source with such a configuration would be too expensive for general use at the current price of LEDs, and there is no need for it to have such high brightness for practical purposes.
以上説明したように本発明によれば、表面の輝度の均一
性が良好で、経済性に優れた、透過形液晶表示装置の背
後光源に好適な板状光源が得られる。As explained above, according to the present invention, it is possible to obtain a plate-shaped light source that has good surface brightness uniformity, is excellent in economic efficiency, and is suitable as a back light source for a transmissive liquid crystal display device.
第１図（ａ）は本発明一実施例の平面図、第１図（ｂ）
は同実施例の側面図、第２図は本発明に係る導光板上の
位置と表面の粗さの関係を示す図である。
１−Ｌ Ｅ Ｄ、 ２・−導光板、 ３・−・反射板。
代理人 弁理士 小川 勝馬 、FIG. 1(a) is a plan view of one embodiment of the present invention, FIG. 1(b)
2 is a side view of the same embodiment, and FIG. 2 is a diagram showing the relationship between the position on the light guide plate and the surface roughness according to the present invention. 1-LED, 2--light guide plate, 3-- reflecting plate. Agent: Katsuma Ogawa, patent attorney
Claims (1)
晶表示装置の光源となる板状光源を、透光性板で作成し
、板の端部に接して、該透光性板材内部に光が入射する
ように点光源を配設し、板の表面に、前記点光源からの
距離に依存して粗さの程度を変えた粗面加工を施し、こ
の板の更に背後外側に反射面を密着させて反射板を配置
したことを特徴とする液晶表示装置用板状光源。 ２、前記点光源が発光ダイオードであることを特徴とす
る特許請求の範囲第１項記載の液晶表示装置用板状光源
。[Claims] 1. A plate-shaped light source that is placed behind the back polarizing plate of a liquid crystal cell and serves as a light source for a transmissive liquid crystal display device is made of a transparent plate, and is in contact with the edge of the plate, A point light source is arranged so that light enters the inside of the translucent plate material, and the surface of the plate is roughened so that the degree of roughness changes depending on the distance from the point light source. 1. A plate-shaped light source for a liquid crystal display device, characterized in that a reflective plate is disposed in close contact with a reflective surface on the rear outer side of the plate. 2. The plate-shaped light source for a liquid crystal display device according to claim 1, wherein the point light source is a light emitting diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62000378A JP2728397B2 (en) | 1987-01-07 | 1987-01-07 | Liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62000378A JP2728397B2 (en) | 1987-01-07 | 1987-01-07 | Liquid crystal display |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63168604A true JPS63168604A (en) | 1988-07-12 |
| JP2728397B2 JP2728397B2 (en) | 1998-03-18 |
Family
ID=11472134
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62000378A Expired - Lifetime JP2728397B2 (en) | 1987-01-07 | 1987-01-07 | Liquid crystal display |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2728397B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63220104A (en) * | 1987-03-09 | 1988-09-13 | Fujitsu Ltd | Guide for illuminating light |
| JPH0491304U (en) * | 1990-12-26 | 1992-08-10 | ||
| JPH04270302A (en) * | 1991-02-26 | 1992-09-25 | Kimoto & Co Ltd | Light transmission plate for panel light source |
| JPH08160229A (en) * | 1994-12-08 | 1996-06-21 | Create Kk | Light guide plate and its manufacture, and surface light source device |
| JP2002042529A (en) * | 2000-07-24 | 2002-02-08 | Sanyo Electric Co Ltd | Surface lighting device |
| JP2014146750A (en) * | 2013-01-30 | 2014-08-14 | Koito Mfg Co Ltd | Light emitting module |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS587603A (en) * | 1981-07-07 | 1983-01-17 | Mitsubishi Electric Corp | Illuminating device for optical fiber |
| JPS5899709U (en) * | 1981-12-28 | 1983-07-07 | 日本精機株式会社 | lighting equipment |
| JPS61145902U (en) * | 1985-02-28 | 1986-09-09 |
-
1987
- 1987-01-07 JP JP62000378A patent/JP2728397B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS587603A (en) * | 1981-07-07 | 1983-01-17 | Mitsubishi Electric Corp | Illuminating device for optical fiber |
| JPS5899709U (en) * | 1981-12-28 | 1983-07-07 | 日本精機株式会社 | lighting equipment |
| JPS61145902U (en) * | 1985-02-28 | 1986-09-09 |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63220104A (en) * | 1987-03-09 | 1988-09-13 | Fujitsu Ltd | Guide for illuminating light |
| JPH0491304U (en) * | 1990-12-26 | 1992-08-10 | ||
| JPH04270302A (en) * | 1991-02-26 | 1992-09-25 | Kimoto & Co Ltd | Light transmission plate for panel light source |
| JP2703412B2 (en) * | 1991-02-26 | 1998-01-26 | 株式会社きもと | Light guide plate for planar light source |
| JPH08160229A (en) * | 1994-12-08 | 1996-06-21 | Create Kk | Light guide plate and its manufacture, and surface light source device |
| JP2002042529A (en) * | 2000-07-24 | 2002-02-08 | Sanyo Electric Co Ltd | Surface lighting device |
| JP2014146750A (en) * | 2013-01-30 | 2014-08-14 | Koito Mfg Co Ltd | Light emitting module |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2728397B2 (en) | 1998-03-18 |
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