JP2507092Y2 - Surface light source - Google Patents
Surface light sourceInfo
- Publication number
- JP2507092Y2 JP2507092Y2 JP1989131010U JP13101089U JP2507092Y2 JP 2507092 Y2 JP2507092 Y2 JP 2507092Y2 JP 1989131010 U JP1989131010 U JP 1989131010U JP 13101089 U JP13101089 U JP 13101089U JP 2507092 Y2 JP2507092 Y2 JP 2507092Y2
- Authority
- JP
- Japan
- Prior art keywords
- light source
- light guide
- light
- diffusion
- source device
- 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 - Lifetime
Links
- 238000009792 diffusion process Methods 0.000 claims description 19
- 239000000463 material Substances 0.000 description 6
- 239000004925 Acrylic resin Substances 0.000 description 3
- 229920000178 Acrylic resin Polymers 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 229920000306 polymethylpentene Polymers 0.000 description 2
- 239000011116 polymethylpentene Substances 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 1
Landscapes
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
Description
【考案の詳細な説明】 ［産業上の利用分野］ 本考案は、液晶表示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 field of use] The present invention relates to a surface light source device using a light guide used for a backlight of a liquid crystal display device or the like.
［従来の技術］ 従来知られている導光体を用いた面光源装置は、第２
図に示す通りの構成である。即ち、光源１と、入射端面
を光源に近接させ配置した導光体２と、導光体２の表面
に設けた拡散面３と、導光体２の裏面に設けた反射面４
とより構成されている。そして光源１よりの光が入射端
面より導光体２に入射しその内部を表面，裏面で反射し
ながら入射端面と反対側へ伝えられて行く間にその一部
が拡散面３を通り拡散光として出て行くことによって拡
散面から均一な拡散光を発する面光源となる。[Prior Art] A surface light source device using a conventionally known light guide is a second light source device.
The configuration is as shown in the figure. That is, the light source 1, the light guide 2 whose incident end face is arranged close to the light source, the diffusion surface 3 provided on the front surface of the light guide 2, and the reflection surface 4 provided on the back surface of the light guide 2.
It is composed of Then, while the light from the light source 1 is incident on the light guide 2 from the incident end face and is transmitted to the side opposite to the incident end face while being reflected on the inside and the inside of the light guide body 2, a part thereof passes through the diffusion face 3 and diffused light. And becomes a surface light source that emits uniform diffused light from the diffusing surface.
［考案が解決しようとする課題］ このような構成の従来の導光体を用いた面光源装置
は、第２図に示すように、光源１よりの光は任意の入射
角で入射端面より入射し、導光体の表面．裏面にて反射
されながら進むため、拡散面３を通る光も最も強い光は
拡散面３に対して傾斜した光で、そのために拡散面３に
垂直な方向よりも斜め方向への光の輝度が高く、垂直方
向より見る画像よりも斜め方向より見る画像の方が明る
いと云う欠点があった。[Problems to be Solved by the Invention] In a surface light source device using a conventional light guide having such a configuration, as shown in FIG. 2, light from the light source 1 is incident from an incident end face at an arbitrary incident angle. The surface of the light guide. Since light travels while being reflected on the back surface, the light that also has the strongest light passing through the diffusing surface 3 is light that is tilted with respect to the diffusing surface 3, and therefore the brightness of the light in the oblique direction is greater than the direction perpendicular to the diffusing surface 3. There is a drawback that it is high and that an image viewed from an oblique direction is brighter than an image viewed from a vertical direction.
実験の結果、第２図に示すような構成の面光源装置
で、導光体の材質が屈折率が1.50である透明なアクリル
樹脂である場合、最も高い輝度を示す方向は、第２図に
おけるγの値が約75°（74.6°）の方向であった。As a result of the experiment, in the surface light source device configured as shown in FIG. 2, when the material of the light guide is a transparent acrylic resin having a refractive index of 1.50, the direction showing the highest brightness is as shown in FIG. The value of γ was in the direction of about 75 ° (74.6 °).
本考案の目的は、拡散面に垂直方向の輝度が明るく、
垂直方向からの明るい画像の観察が可能な導光体を用い
た面光源装置を提供するものである。The purpose of the present invention is to increase the brightness in the vertical direction to the diffusion surface,
It is intended to provide a surface light source device using a light guide body capable of observing a bright image from a vertical direction.
［課題を解決するための手段］ 本考案の面光源装置は、光源と、入射端面を光源に近
接させて配置した導光体と、導光体の表面に設けられた
拡散面と、導光体の裏面に設けられた反射面とよりな
り、更に拡散面に、一方の面が鋸歯状をした透明板を、
鋸歯状をした面が拡散面とは反対方向を向くように配置
したもので、この透明板の屈折作用によって出射光の進
行方向を拡散板に対し垂直に近い方向とし、その方向の
輝度を向上させるようにしたものである。[Means for Solving the Problems] A surface light source device of the present invention includes a light source, a light guide body whose incident end face is arranged close to the light source, a diffusion surface provided on the surface of the light guide body, and a light guide body. A transparent plate consisting of a reflective surface provided on the back surface of the body and a sawtooth-shaped transparent surface on the diffusion surface.
It is arranged so that the sawtooth surface faces the direction opposite to the diffusion surface, and the refraction of this transparent plate makes the traveling direction of the emitted light nearly perpendicular to the diffusion plate, improving the brightness in that direction. It was made to let.
また、上記の透明板の鋸歯状をした面とは反対側の面
に拡散作用を持たせるように加工を施し、この面を拡散
面として、透明板を導光体の表面に、鋸歯状の面が導光
体とは反対方向を向くように配置した構成としてもよ
い。これによって導光体表面からの光が透明体を通る
際、拡散面にて拡散光となり更に鋸歯状部分にて屈折さ
れて拡散光が垂直方向へ向かうようにした。In addition, the surface of the transparent plate opposite to the serrated surface is processed to have a diffusing effect, and this surface is used as a diffusing surface, and the transparent plate is used as the sawtooth surface. The surface may be arranged so as to face the opposite direction to the light guide. As a result, when the light from the light guide surface passes through the transparent body, it becomes diffused light on the diffusing surface and is further refracted at the sawtooth portion so that the diffused light goes in the vertical direction.
このように拡散面と鋸歯状部分とを組合わせることに
より拡散面に垂直な方向での輝度を大にすることが出来
る。By combining the diffusing surface and the sawtooth portion in this manner, it is possible to increase the brightness in the direction perpendicular to the diffusing surface.
更に本考案の面光源装置は、導光体を構成する透明体
の材質を屈折率の低い材質としたもので、これによって
導光体表面より射出する光の傾き角を小さくし、更に拡
散面と鋸歯状部とによって前記の傾き角による影響を除
去して垂直方向への光が明るく均一な輝度分布になるよ
うにしている。Further, in the surface light source device of the present invention, the material of the transparent body forming the light guide is made of a material having a low refractive index, whereby the inclination angle of the light emitted from the surface of the light guide is reduced, and the diffusion surface is further reduced. The sawtooth portion eliminates the influence of the tilt angle so that the light in the vertical direction has a bright and uniform luminance distribution.
［実施例］ 次に本考案の実施例を図面にもとづいて説明する。[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.
第１図は、本考案の面光源装置の実施例を示す断面図
で、１は光源、２は導光体、４は反射面、５は拡散板、
７は導光体２とは反対側の面が鋸歯状7aをなした透明板
である。FIG. 1 is a sectional view showing an embodiment of a surface light source device of the present invention, 1 is a light source, 2 is a light guide, 4 is a reflecting surface, 5 is a diffusion plate,
Reference numeral 7 is a transparent plate having a sawtooth-shaped surface 7a on the side opposite to the light guide 2.
この実施例においては、導光体２より外部へ出る光
は、まず拡散板５で拡散光となり次いで鋸歯状部分7aを
有する透明板７でその多くが上方へ向けられ、拡散面に
対し垂直方向の明るさが増大する。In this embodiment, the light emitted from the light guide 2 is first diffused by the diffuser plate 5, and then most of the light is directed upward by the transparent plate 7 having the sawtooth portion 7a. Brightness increases.
この実施例の装置を用いて実験した結果、拡散面に垂
直な方向で50％の明るさの増加がみられた。As a result of an experiment using the apparatus of this example, a 50% increase in brightness was observed in the direction perpendicular to the diffusion surface.
この実施例において、透明板７の平面7b側を粗面とす
る等の加工を施すことにより、それを拡散面とすれば拡
散板５を省略することが出来る。In this embodiment, the diffusion plate 5 can be omitted by processing the transparent plate 7 such that the flat surface 7b side is a rough surface so that the surface is a diffusion surface.
又実施例において鋸歯状部を有する透明板を複数用い
れば、拡散面に垂直な方向の明るさを一層増大させ得
る。しかし部品が多くなりコスト高になる。If a plurality of transparent plates having a serrated portion are used in the embodiment, the brightness in the direction perpendicular to the diffusion surface can be further increased. However, the number of parts increases and the cost increases.
この実施例における透明板５の鋸歯の形状は各種のも
のが考えられる。例えば図に示すθ1，θ2がθ1＝θ2，
θ1＜θ2，θ1＞θ2等が考えられる。しかしθ1とθ2の
値が大きく異なっている場合には、この鋸歯状により観
察される像に影響を及ぼすため好ましくない。したがっ
てθ1，θ2は等しいかほぼ等しいものが好ましい。尚前
記の実験結果はθ1＝θ2のもので行なわれた。Various shapes of saw teeth of the transparent plate 5 in this embodiment can be considered. For example, θ 1 and θ 2 shown in the figure are θ 1 = θ 2 ,
θ 1 <θ 2 , θ 1 > θ 2 etc. are considered. However, if the values of θ 1 and θ 2 are greatly different, it affects the image observed by the sawtooth shape, which is not preferable. Therefore, it is preferable that θ 1 and θ 2 are equal or almost equal. The above experimental results were performed with θ 1 = θ 2 .
又、前述のように従来の面光源装置の導光体は、アク
リル樹脂が用いられ、その最も輝度の高い方向は、実験
の結果74.6°であった。このことから導光体内を順次反
射しながら進む光のうち、第３図に示す角αが約40°の
光が最も光量が大であると考えられる。又導光体の屈折
率によって角αの光が導光体を出る時の角γは異なり、
αは一定であれば屈折率が小さい程γは小である。Further, as described above, the light guide of the conventional surface light source device uses acrylic resin, and the direction of the highest brightness was 74.6 ° as a result of the experiment. From this, it is considered that the light having the angle α of about 40 ° shown in FIG. Also, the angle γ when the light of the angle α exits the light guide depends on the refractive index of the light guide,
If α is constant, the smaller the refractive index, the smaller γ.
本考案は、この点を利用して導光体の屈折率を小にし
てγの値を出来る限り小にし、拡散面に垂直な方向の輝
度が一層大になるようにした。The present invention takes advantage of this point to make the refractive index of the light guide small and make the value of γ as small as possible so that the luminance in the direction perpendicular to the diffusion surface is further increased.
例えば導光体の材料としてポリメチルペンテン（ｎ＝
1.45）を用いた場合、下記の式からγ＝68.8°となる。For example, polymethylpentene (n =
When 1.45) is used, γ = 68.8 ° from the following formula.
sin γ＝nsin α つまりｎ＝1.45,α＝40°とすればγ＝69°である。 sin γ = nsin α In other words, if n = 1.45 and α = 40 °, then γ = 69 °.
上記材料の導光体により実験した結果はγ≒69°にお
いて最も輝度が大であった。As a result of the experiment using the light guide made of the above material, the highest brightness was obtained at γ≈69 °.
このように低屈折率材料を用いた導光体は、最も輝度
の高い方向が垂直方向よりあまり傾いていないために、
本考案の面光源装置にこの低屈折率の導光体を用いれば
極めて有効である。As described above, in the light guide body using the low refractive index material, the direction with the highest brightness is not inclined much more than the vertical direction.
It is extremely effective to use this light guide having a low refractive index in the surface light source device of the present invention.
尚ポリメチルペンテンは一例であって透明度が高く、
耐熱性等の性質を有し屈折率の低い材料であればよい。
しかしｎ＞1.45であるとカクリル樹脂とあまり差がない
ため効果が少ない。したがってｎ≦1.45であることが望
ましい。Polymethylpentene is an example and has high transparency,
Any material having properties such as heat resistance and a low refractive index may be used.
However, if n> 1.45, the effect is small because there is not much difference from the acrylic resin. Therefore, it is desirable that n ≦ 1.45.
［考案の効果］ 本考案の面光源装置は、拡散面に垂直な方向の輝度が
高く、通常のディスプレーの観察方向での明るさが大で
あるため明るい像での観察を可能にする。[Advantages of the Invention] The surface light source device of the present invention has a high brightness in the direction perpendicular to the diffusion surface and has a large brightness in the viewing direction of a normal display, and thus enables a bright image to be viewed.
第１図は本考案の実施例の断面図、第２図は従来の面光
源装置の断面図である。 1:光源、２…導光体、４…反射面、５…拡散板、７…透
明板FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional surface light source device. 1: light source, 2 ... light guide, 4 ... reflective surface, 5 ... diffusion plate, 7 ... transparent plate
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭51−102498（ＪＰ，Ａ) 特開 昭52−109393（ＪＰ，Ａ) 特開 昭52−141598（ＪＰ，Ａ) 特開 平２−84618（ＪＰ，Ａ) 実開 昭52−76291（ＪＰ，Ｕ) 米国特許4729067（ＵＳ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-51-102498 (JP, A) JP-A-52-109393 (JP, A) JP-A-52-141598 (JP, A) JP-A-2- 84618 (JP, A) Actual development Sho 52-76291 (JP, U) US Patent 4729067 (US, A)
Claims (2)
た導光体と、前記導光体の表面に設けられた拡散面と、
前記導光体の裏面に設けられた反射面とを備えた面光源
装置において、前記拡散面上に、一方の面が鋸歯状をし
た透明板を、前記鋸歯状をした面が前記拡散面とは反対
方向を向くように配置したことを特徴とする面光源装
置。1. A light source, a light guide body having an incident end face disposed in the vicinity of the light source, and a diffusion surface provided on the surface of the light guide body.
In a surface light source device having a reflection surface provided on the back surface of the light guide, a transparent plate having a sawtooth shape on one surface is provided on the diffusion surface, and the sawtooth surface is the diffusion surface. Is a surface light source device characterized by being arranged so as to face in the opposite direction.
面とは反対側の面に拡散作用を持たせることにより構成
したことを特徴とする請求項（１）の面光源装置。2. The surface light source device according to claim 1, wherein the diffusing surface is formed by giving a diffusing action to a surface of the transparent plate opposite to the saw-toothed surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989131010U JP2507092Y2 (en) | 1989-11-13 | 1989-11-13 | Surface light source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989131010U JP2507092Y2 (en) | 1989-11-13 | 1989-11-13 | Surface light source |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0369184U JPH0369184U (en) | 1991-07-09 |
| JP2507092Y2 true JP2507092Y2 (en) | 1996-08-14 |
Family
ID=31678539
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1989131010U Expired - Lifetime JP2507092Y2 (en) | 1989-11-13 | 1989-11-13 | Surface light source |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2507092Y2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2723414B2 (en) * | 1992-01-27 | 1998-03-09 | 積水化学工業 株式会社 | Planar light emitting device |
| DE60036733T2 (en) | 2000-07-24 | 2008-07-17 | Mitsubishi Rayon Co., Ltd. | SURFACE LIGHTING DEVICE |
| JP2006179475A (en) * | 2004-11-24 | 2006-07-06 | Toshiba Matsushita Display Technology Co Ltd | Surface light source device and liquid crystal display device provided with the same |
| JP4006650B1 (en) | 2006-05-08 | 2007-11-14 | ソニー株式会社 | Optical film, method for producing the same, and display device |
| JP5026125B2 (en) * | 2007-03-23 | 2012-09-12 | 株式会社奥村組 | Tower-like structure dismantling device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4729067A (en) | 1986-09-26 | 1988-03-01 | Mitsubishi Rayon Company Ltd. | Light diffusing device |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51102498A (en) * | 1975-03-06 | 1976-09-09 | Suwa Seikosha Kk | EKISHOHYOJISOCHI |
| JPS5276291U (en) * | 1975-12-05 | 1977-06-07 | ||
| JPS52109393A (en) * | 1976-03-10 | 1977-09-13 | Hitachi Ltd | Liquid crystal display element |
| CH614599GA3 (en) * | 1976-04-29 | 1979-12-14 | Passive electro-optical display device and method for manufacturing it | |
| JPS5525641A (en) * | 1978-08-11 | 1980-02-23 | Mitsubishi Heavy Ind Ltd | Dredger |
| JPS5637124A (en) * | 1979-09-04 | 1981-04-10 | Mitsubishi Rayon Co Ltd | Production of synthetic resin light diffusing sheet |
| JPS634208Y2 (en) * | 1979-10-31 | 1988-02-02 | ||
| JPS5822445B2 (en) * | 1982-07-08 | 1983-05-09 | 株式会社 ミドリ十字 | Method for producing stable solid human plasma cholinesterase preparation |
| JPS63239702A (en) * | 1987-03-27 | 1988-10-05 | 株式会社小糸製作所 | Lens lighting apparatus for decoration |
| US4791540A (en) * | 1987-05-26 | 1988-12-13 | Minnesota Mining And Manufacturing Company | Light fixture providing normalized output |
| JPS6437801A (en) * | 1987-08-04 | 1989-02-08 | Matsushita Electric Ind Co Ltd | Voltage nonlinear element |
| JPH01234821A (en) * | 1988-03-16 | 1989-09-20 | Hitachi Ltd | liquid crystal display device |
| JP2806937B2 (en) * | 1988-03-23 | 1998-09-30 | 富士通株式会社 | Surface lighting device |
| JPH0727137B2 (en) * | 1988-06-02 | 1995-03-29 | 三菱レイヨン株式会社 | Surface light source element |
-
1989
- 1989-11-13 JP JP1989131010U patent/JP2507092Y2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4729067A (en) | 1986-09-26 | 1988-03-01 | Mitsubishi Rayon Company Ltd. | Light diffusing device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0369184U (en) | 1991-07-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2692025B2 (en) | Planar light emitter device | |
| US4729067A (en) | Light diffusing device | |
| JP3873835B2 (en) | Liquid crystal display device and electronic device | |
| JPH02245788A (en) | Thin plane light source device with uniform brightness | |
| US6402335B1 (en) | Light guide panel and plane illuminator apparatus | |
| JP2008209929A (en) | Light source device and light deflection element used therefor | |
| JPH0727136B2 (en) | Surface light source element | |
| JPH1124584A (en) | Backlight device for liquid crystal display | |
| JP3455884B2 (en) | Prism sheet | |
| EP2278216B1 (en) | Illumination device and liquid crystal display apparatus | |
| US7905647B2 (en) | Prism sheet, back light unit using the same and liquid crystal display device having the back light unit | |
| JP3452077B2 (en) | Surface light source device | |
| JPH10106327A (en) | Surface light source element and display apparatus using the element | |
| JP2507092Y2 (en) | Surface light source | |
| JPH0581909B2 (en) | ||
| JP2540549B2 (en) | Lighting equipment | |
| JPH0432888A (en) | surface light source structure | |
| JP2590227Y2 (en) | Surface light source device | |
| JP3042842B2 (en) | Surface light source element | |
| JP3249896B2 (en) | Backlight structure of liquid crystal display | |
| JP4210053B2 (en) | Light source device | |
| JPH08211230A (en) | Back light structure of liquid crystal display device | |
| JP4160297B2 (en) | Optical deflection element | |
| JPH10133200A (en) | Liquid crystal display | |
| JP3209956B2 (en) | Backlight unit and liquid crystal display device |