JPH1048428A - Light-guiding plate unit for liquid crystal display - Google Patents
Light-guiding plate unit for liquid crystal displayInfo
- Publication number
- JPH1048428A JPH1048428A JP8219318A JP21931896A JPH1048428A JP H1048428 A JPH1048428 A JP H1048428A JP 8219318 A JP8219318 A JP 8219318A JP 21931896 A JP21931896 A JP 21931896A JP H1048428 A JPH1048428 A JP H1048428A
- Authority
- JP
- Japan
- Prior art keywords
- light
- guide plate
- liquid crystal
- crystal display
- light guide
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、液晶ディスプレイ
用導光板ユニットに関し、さらに詳細には、液晶ディス
プレイにモアレ縞を生じさせることなく、輝度を高く
し、且つ、ディスプレイの輝度が均一となる液晶ディス
プレイ用導光板ユニットに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate unit for a liquid crystal display, and more particularly, to a liquid crystal display having a high luminance without causing moire fringes on the liquid crystal display and having a uniform luminance of the display. The present invention relates to a light guide plate unit for a display.
【０００２】[0002]
【従来の技術】現在液晶用導光板のユニットの代表的な
例は、図６に示す如くで、側面に光源を配し光源から遠
ざかるに従って漸狭となる透光性の導光板を有し、その
表面の光の放散面側に通常拡散シ−トといわれるものを
配し、更にその上に液晶ディスプレイに集光させるプリ
ズムシ−トを配し、裏側に反射シ−トを配設して成るも
のである（現行システム）。2. Description of the Related Art At present, a typical example of a light guide plate unit for a liquid crystal is shown in FIG. A diffused sheet is usually arranged on the light-dissipating surface side of the surface, a prism sheet for condensing light on the liquid crystal display is arranged thereon, and a reflective sheet is arranged on the back side. (Current system).
【０００３】しかし、上記導光板ユニットは、一定ピッ
チの凹凸を有するプリズムシ−トのパタ−ンと、液晶デ
ィスプレイが画素を形成するため縦横に形成する一定の
パタ−ンとが干渉をおこして縞模様を発生し、例えば、
Ｎ本／ｍｍと５Ｎ本／ｍｍの定ピッチのパタ−ンがある
場合に５Ｎ本毎に同じパタ−ンが縞模様となって繰り返
される所謂モアレ縞現象を惹起し易く、このモアレ縞の
発生が画面を見づらくする大きな要因となっている。However, in the light guide plate unit, a pattern of a prism sheet having irregularities at a fixed pitch and a fixed pattern formed vertically and horizontally by a liquid crystal display to form a pixel interfere with each other to produce stripes. Generate patterns, for example,
When there are patterns with a constant pitch of N lines / mm and 5N lines / mm, a so-called moire fringe phenomenon is easily caused in which the same pattern is repeated as a stripe pattern every 5N lines, and this moire fringe is generated. Is a major factor that makes it difficult to see the screen.
【０００４】一方、これを防ぐべく、現行システムで拡
散シ−トをプリズムシ−トの上に持ってくると、光の放
散によって輝度が低下し、ディスプレイの画面全体が暗
くなるという難点が生じる。On the other hand, in order to prevent this, if a diffusion sheet is placed on a prism sheet in the current system, there is a problem in that the luminance is reduced due to the diffusion of light, and the entire screen of the display becomes dark.
【０００５】又、上記導光板ユニットに用いるプリズム
シ−トを用い、表面に施す凹凸のピッチが例えば５０ミ
クロン程度の精緻な加工を要するので、生産コストが高
くなるという欠点がある。Further, since the prism sheet used for the light guide plate unit is required to be finely processed, for example, the pitch of the unevenness applied to the surface is, for example, about 50 microns, there is a disadvantage that the production cost is increased.
【０００６】[0006]
【発明が解決しようとする課題】そこで、本発明は、モ
アレ縞の発生を抑えて画面を見やすくすると共に、画面
全体の輝度が高く且つ均一な明るさとし、生産面におい
てもコスト低減が図れる導光板ユニットを開発しようと
するものである。SUMMARY OF THE INVENTION Accordingly, the present invention provides a light guide plate which suppresses the occurrence of moiré fringes to make the screen easy to see, and has high brightness and uniform brightness over the entire screen, thereby reducing costs in production. They want to develop a unit.
【０００７】[0007]
【課題を解決するための手段】本発明液晶ディスプレイ
用導光板ユニットは、側面を受光面とし、表面を断面三
角形状のプリズム構造の凹凸に形成した光放散面とし、
裏面を光反射面としたプラスチック導光板を有し、該プ
リズム構造の光放射面から放たれた光を散乱させて液晶
ディスプレイとの相互干渉を防止する０．０３〜０．２
５ｍｍの厚みの干渉遮断シ−トを前記導光板と可及的に
近い位置に配設し、液晶ディスプレイにモアレ縞を発生
させることなく光源からの光を照射することを特徴とし
て構成される。According to the present invention, there is provided a light guide plate unit for a liquid crystal display, wherein a side surface is a light-receiving surface, and a surface is a light-dissipating surface formed with irregularities of a prism structure having a triangular cross section.
A plastic light guide plate having a back surface as a light reflecting surface, which scatters light emitted from the light emitting surface of the prism structure to prevent mutual interference with a liquid crystal display;
An interference blocking sheet having a thickness of 5 mm is arranged as close as possible to the light guide plate, and the liquid crystal display is irradiated with light from a light source without generating moire fringes.
【０００８】該プラスチック導光板が、光放射面の表面
を断面三角形状のプリズム構造に形成すると共該プリズ
ム構造の間に光源からの光を反射する平坦面を形成して
成るのが望ましい。It is preferable that the plastic light guide plate has a flat surface for reflecting light from a light source between the prism structures when the surface of the light emitting surface is formed in a prism structure having a triangular cross section.
【０００９】又、該導光板は、その光反射面側を、光源
からの光をより遠方に伝播する平行面と、楔形の傾斜面
とに形成して成るのが望ましい。It is desirable that the light guide surface of the light guide plate is formed of a parallel surface for transmitting light from a light source to a farther place and a wedge-shaped inclined surface.
【００１０】表面に形成した光放散面の断面三角形状の
プリズム構造の凹凸により、光が垂直方向に放射される
ので、光が液晶ディスプレイに向けて集中的に放散し、
且つ、それが導光板と一体的に形成されているので、光
の洩漏がなく、光の利用効率が高い。又、液晶ディスプ
レイと光放散面との間に０．０３〜０．２５ｍｍの厚み
の干渉遮断シ−トが介在するので、一定規則で干渉する
波動として光の性格を改め、一種の不規則性を持ち込ん
で互いの干渉による強弱が緩和し、モアレ縞の発生を抑
制する。又、干渉遮断シ−トの位置を可及的に光放散面
に近づけると、プリズム構造の凹凸を出た区々の放射角
の光を捉えて垂直方向に向わせ、画面の輝度を向上させ
る。Light is radiated in the vertical direction due to the unevenness of the prism structure having a triangular cross section of the light diffusing surface formed on the surface, so that the light is radiated intensively toward the liquid crystal display.
Moreover, since it is formed integrally with the light guide plate, there is no light leakage and the light utilization efficiency is high. In addition, since an interference blocking sheet having a thickness of 0.03 to 0.25 mm is interposed between the liquid crystal display and the light diffusion surface, the nature of light is improved as a wave that interferes with a regular rule, and a kind of irregularity is generated. To reduce the intensity due to mutual interference and suppress the generation of moiré fringes. Also, when the position of the interference blocking sheet is as close as possible to the light radiating surface, the light of various radiation angles, which have come out of the irregularities of the prism structure, is captured and directed vertically, thereby improving the brightness of the screen. .
【００１１】光放散面にプリズム構造の凹凸の間に平坦
面を形成すると、光源に近い光をより離れた位置に反射
させ、ディスプレイ全体の明るさを均一化する。又、導
光板の反射面を光源に近い側の反射面を放散面と平行状
態となる平行面に形成すると、反射角が低くなるので、
光をより光源から離れた位置に反射させ、ディスプレイ
の画面照度を均一化する。そして、この平坦面と平行面
との組み合わせは互いの効果を高める。When a flat surface is formed between the irregularities of the prism structure on the light diffusion surface, light near the light source is reflected to a position farther away, and the brightness of the entire display is made uniform. Also, if the reflection surface of the light guide plate is formed as a parallel surface that is in a state parallel to the diffusion surface, the reflection surface on the side closer to the light source will reduce the reflection angle,
Light is reflected to a position further away from the light source, and the illuminance of the display screen is made uniform. The combination of the flat surface and the parallel surface enhances the mutual effect.
【００１２】[0012]
【発明の実施の形態】本発明に用いる導光板１は、アク
リル、ポリカ−ボネ−ト、ポリスチレン、ＡＢＳ、ＰＶ
Ｃ等の熱可塑性樹脂、シリコ−ンゴム、ポリエステル、
エポキシ、ポリウレタン等の熱硬化性樹脂を用いるが、
これに限定されるものではなく、透光性に秀れ、且つ、
加工性の良好なものなら良い上記プラスチックのうち、
生産性、プリズム転写性等の点で射出成形による賦形可
能なアクリル樹脂が最も好適である。BEST MODE FOR CARRYING OUT THE INVENTION A light guide plate 1 used in the present invention is made of acrylic, polycarbonate, polystyrene, ABS, PV, or the like.
Thermoplastic resin such as C, silicone rubber, polyester,
Epoxy, thermosetting resin such as polyurethane is used,
It is not limited to this, excels in translucency, and
Of the above plastics that have good workability,
Acrylic resin that can be shaped by injection molding is most preferable in terms of productivity, prism transferability, and the like.
【００１３】該導光板１の光放散面２に、断面三角形状
のプリズム構造の凹凸を形成し、プリズムと導光板とを
一体的に形成する。該プリズム構造とは、光を垂直方向
に放射させる特性を有するもので、この特性を利用して
導光板に入射した光を光放散面から最も効率的に液晶デ
ィスプレイに照射させることを狙いとし、ピッチを２０
〜１２００ミクロン程度で望ましくは５０〜５００ミク
ロン程度とし、三角形の高さをピッチの１／２程度とす
る（図１（Ｂ）参照）。そして、このプリズム構造の凹
凸の刻設方向は、光源に対し直角方向となる態様を図示
したが、平行方向又は斜め方向であっても良い。On the light diffusing surface 2 of the light guide plate 1, irregularities having a prism structure having a triangular cross section are formed, and the prism and the light guide plate are integrally formed. The prism structure has a characteristic of emitting light in the vertical direction, and aims to irradiate the light incident on the light guide plate to the liquid crystal display most efficiently from the light diffusion surface by using this characteristic, 20 pitch
The height of the triangle is about 1/2 of the pitch (see FIG. 1B). The direction in which the unevenness of the prism structure is formed is perpendicular to the light source, but may be parallel or oblique.
【００１４】該光放散面２には、プリズム構造の凹凸を
連続的に形成するが、液晶ディスプレイ５への照射を均
一化する目的で、上記プリズム構造の凹凸の間に光を反
射可能な平坦面２ａを形成するのが望ましい。即ち、該
平坦面２ａは、図２（Ａ）及び（Ｂ）に示す如くで、光
源８から入射した直接の光又は反射面３からの光を受け
て、より光源から離れた位置に反射させる機能を果すも
のである。何故なら、プリズム構造の凹凸のみを連続的
に形成すると、相対的に光源に近い位置の光が優先的に
放散し、通常拡散シ−トといわれるものとを組み合わせ
ても、光源から離れるにしたがって光の放散量が減少
し、結果としてディスプレイ画面の光源に近い部分は明
るく、光源より遠ざかるにつれて暗くなり、輝度分布が
不均一となるからである。この為、該平坦面２ａは、一
般的には光源８に近い位置ほど多くし、光源８から離れ
るにつれて少なくするのが望ましい。又、上記のように
平坦面２ａを部分的に有した導光板１と液晶ディスプレ
イ５とを組み合わせて使う場合、両者が干渉してモアレ
縞が発生する。従って、両者間に相互干渉を防止する干
渉遮断シ−ト６を配設することが有効である。On the light diffusion surface 2, irregularities of the prism structure are continuously formed. For the purpose of making the irradiation on the liquid crystal display 5 uniform, a flat surface capable of reflecting light between the irregularities of the prism structure. It is desirable to form surface 2a. That is, as shown in FIGS. 2A and 2B, the flat surface 2a receives the direct light incident from the light source 8 or the light from the reflection surface 3 and reflects the light to a position further away from the light source. It fulfills its function. This is because, when only the irregularities of the prism structure are continuously formed, light at a position relatively close to the light source is preferentially radiated, and even when combined with what is usually called a diffusion sheet, as the distance from the light source increases, This is because the amount of scattered light is reduced, and as a result, the portion of the display screen near the light source is bright, and becomes darker as the distance from the light source increases, and the luminance distribution becomes uneven. For this reason, it is generally desirable to increase the flat surface 2a at a position closer to the light source 8 and to decrease the flat surface 2a as the distance from the light source 8 increases. Further, when the light guide plate 1 partially having the flat surface 2a and the liquid crystal display 5 are used in combination, moire fringes occur due to interference between the two. Therefore, it is effective to provide an interference blocking sheet 6 for preventing mutual interference between them.
【００１５】又、導光板１の底面となる反射面３は、従
来は傾斜面として光源から離れるほど漸狭としている
が、本発明では、光源に近い側の反射面３を放散面２と
平行状態となる平行面３ａに形成するのが望ましい（図
３（Ａ）参照）。これは図３（Ｂ）に示す如く、反射面
３からの光の反射角を傾斜面と比較して低い角として、
光をより光源から離れた位置に反射させて、上記平坦面
と同様ディスプレイの画面の明るさを均一化させる為で
ある。従ってこの平行面３ａは、厳格な意味での平行で
なく、若干の傾斜をもたせたものも含まれる。Although the reflection surface 3 serving as the bottom surface of the light guide plate 1 is conventionally made as an inclined surface and gradually narrowed as the distance from the light source increases, in the present invention, the reflection surface 3 on the side closer to the light source is parallel to the diffusion surface 2. It is desirable to form it on the parallel surface 3a in a state (see FIG. 3A). This is because, as shown in FIG. 3B, the angle of reflection of light from the reflecting surface 3 is lower than that of the inclined surface.
This is because the light is reflected to a position further away from the light source to make the brightness of the display screen uniform as with the flat surface. Therefore, the parallel surfaces 3a are not strictly parallel but include those having a slight inclination.
【００１６】そして、上記平坦面２ａと平行面３ａとは
これを組み合わせて、上記光放射面２の表面を断面三角
形状のプリズム構造に形成すると共に該プリズム構造の
間に光源からの光を反射する平坦面２ａを形成し、且
つ、その光反射面側を光源８からの光をより遠方に伝播
する平行面３ａと楔形の傾斜面３ｂとに形成するのがよ
り望ましい。The flat surface 2a and the parallel surface 3a are combined to form the surface of the light emitting surface 2 into a prism structure having a triangular cross section, and reflect light from a light source between the prism structures. It is more desirable to form a flat surface 2a and to form the light reflecting surface side thereof into a parallel surface 3a and a wedge-shaped inclined surface 3b for transmitting the light from the light source 8 farther.
【００１７】又、本発明に用いる干渉遮断シ−ト６は、
アクリル、ポリカ−ボネ−ト、ＰＥＴ等光透過性が良好
で、シ−ト状に加工できるプラスチック材料であれば特
に制限を受けることないが、該シ−トの表面状態は粗化
されていることが必要で、通常１〜１００μｍ程度の面
粗度を有していれば良く、光反射率の高い微粒子をシ−
ト表面に液状コ−ティングし、或いは機械的なエンボス
加工により賦形したものである。その厚みは、３０〜２
５０μｍの範囲とし、それは２５０μｍ以上では全体の
輝度が低下し、画像が暗くなるからで、３０μｍ以下で
は物理的強度が弱くなるからである。The interference shielding sheet 6 used in the present invention comprises:
There is no particular limitation as long as it is a plastic material such as acryl, polycarbonate, PET which has good light transmittance and can be processed into a sheet shape, but the surface state of the sheet is roughened. It is necessary that the fine particles have a surface roughness of usually about 1 to 100 μm.
It is formed by applying a liquid coating or mechanical embossing on its surface. The thickness is 30-2
When the thickness is 250 μm or more, the overall brightness decreases and the image becomes dark, and when the thickness is 30 μm or less, the physical strength becomes weak.
【００１８】次に、本実施形態の作用を説明する。光源
８を出た光は、受光面４から導光板１に入射し、導光板
１内を進行し、又、反射面３及び反射板７に反射され
て、液晶ディスプレイ５に直向した放散面２から放射さ
れる。このとき、光放散面２は断面三角形状のプリズム
構造の凹凸により、光が垂直方向に放射されるので、光
が液晶ディスプレイに向けて集中的に放散し、且つ、そ
れが導光板と一体的に形成されているので、光の洩漏が
なく、光源の光が最も効率良くディスプレイ映写用の光
として利用される。Next, the operation of the present embodiment will be described. The light emitted from the light source 8 enters the light guide plate 1 from the light receiving surface 4, travels inside the light guide plate 1, is reflected by the reflection surfaces 3 and 7, and is a radiation surface directly facing the liquid crystal display 5. Radiated from 2. At this time, light is radiated in the vertical direction on the light diffusion surface 2 due to the unevenness of the prism structure having a triangular cross section. Therefore, there is no light leakage and the light from the light source is most efficiently used as light for display projection.
【００１９】しかし、そのままでは、一定ピッチの凹凸
を有するプリズムシ−トのパタ−ンと、液晶ディスプレ
イのパタ−ンとが干渉をおこして所謂モアレ縞が惹起し
てしまう。そこで、両者の間に干渉遮断シ−ト６が介在
すると、一定規則で干渉する波動として光の性格を改
め、一種の不規則性を持ち込み、互いの干渉による強弱
が緩和し、モアレ縞の発生を抑制する。However, as it is, the pattern of the prism sheet having irregularities at a constant pitch and the pattern of the liquid crystal display interfere with each other, causing so-called moire fringes. Therefore, if an interference blocking sheet 6 is interposed between the two, the nature of light is improved as a wave interfering with a regular rule, a kind of irregularity is brought in, the intensity of mutual interference is reduced, and moire fringes are generated. Suppress.
【００２０】このとき、干渉遮断シ−トは、その位置を
可及的に光放散面２に近づけた位置とする。何故なら、
プリズム構造の凹凸を導光板１と一体的に形成した場合
には、放射角が一定となるプリズム板を別個に設けた場
合とは異なり、放射角が区々となり、この放射光を捉え
て垂直方向に向わせるには、光放散面２に近い方が有利
であり、画面の輝度を向上させることができるからであ
る。At this time, the position of the interference blocking sheet is set as close to the light diffusion surface 2 as possible. Because,
When the irregularities of the prism structure are formed integrally with the light guide plate 1, unlike the case where a prism plate having a constant radiation angle is provided separately, the radiation angles vary, and this radiation light is captured and This is because, in order to direct the light in the direction, it is advantageous to be closer to the light diffusion surface 2 and the luminance of the screen can be improved.
【００２１】又、該光放散面２に、プリズム構造の凹凸
の間に平坦面２ａを形成し、且つ、光源に近い位置ほど
その数を増すと、光源に近い光をより離れた位置に反射
させ、ディスプレイ全体の明るさを均一にすることがで
きる。Further, when a flat surface 2a is formed on the light diffusing surface 2 between the irregularities of the prism structure and the number is increased as the position is closer to the light source, light closer to the light source is reflected to a position farther away. As a result, the brightness of the entire display can be made uniform.
【００２２】又、図３に示す如く、導光板１の反射面３
を、光源に近い側の反射面を放散面と平行状態となる平
行面３ａに形成すると、反射角（α）が傾斜面の反射角
（α’）より低くなるので、光をより光源から離れた位
置に反射させることができ、上記平坦面２ａと同様ディ
スプレイ５の画面照度を均一化させる。As shown in FIG. 3, the reflecting surface 3 of the light guide plate 1 is provided.
Is formed on the parallel surface 3a where the reflection surface close to the light source is parallel to the diffusion surface, the reflection angle (α) becomes lower than the reflection angle (α ′) of the inclined surface, so that the light is further away from the light source. The light can be reflected to a different position, and the screen illuminance of the display 5 is made uniform as in the case of the flat surface 2a.
【００２３】[0023]
【実験例１】導光板の素材としてアクリル樹脂（住友化
学製 ＭＧ−５）を用い、受光面４ｍｍ、終端面１ｍ
ｍ、光放散面７０ｍｍとした楔形に形成し、光放散面に
高さ２５μｍ、ピッチ５０μｍの直角二等辺三角形のプ
リズム構造の凹凸を形成した導光板を射出成形により作
製し、干渉遮断シ−トとして表面粗度５０μｍ、厚み５
０μｍでエンボス加工したものを用い、これを本発明ユ
ニットとした。上記本発明品に対し、下記の通りのユニ
ットを比較対象として選び、これらの輝度分布を観測
し、且つ、モアレ縞の発生状況を目視により観察した。 （Ａ）：本発明ユニット （Ｂ）：本発明ユニットから干渉遮断シ−トを除いたも
の （Ｃ）：現行の導光板の上に干渉遮断シ−トを配し、更
にその上にプリズムシ−トを配置したもの （Ｄ）：上記（Ｃ）の干渉遮断シ−トとプリズムシ−ト
を入替えたもの 輝度の測定方法は、各ユニットと液晶ディスプレイを組
合わせたものを対象物とし、その対象物から１メ−トル
離れた位置に輝度計（ミノルタＬＳ−１１０）を設置
し、光の輝度を測定した（図４参照）。その結果は表１
の通りであった。[Experimental example 1] Acrylic resin (MG-5 manufactured by Sumitomo Chemical Co., Ltd.) was used as the material of the light guide plate, and the light receiving surface was 4 mm and the terminal surface was 1 m
m, a light guide plate having a light dispersing surface of 70 mm formed in a wedge shape, and a light guide plate having a light dispersing surface formed with irregularities of a right-angled isosceles triangular prism structure having a height of 25 μm and a pitch of 50 μm by injection molding. Surface roughness 50 μm, thickness 5
The one embossed with 0 μm was used, and this was used as the unit of the present invention. The following units were selected as comparative objects for the product of the present invention, their luminance distribution was observed, and the occurrence of moiré fringes was visually observed. (A): unit of the present invention (B): unit obtained by removing the interference blocking sheet from the unit of the present invention (C): an interference blocking sheet is arranged on a current light guide plate, and a prism sheet is further placed thereon. (D): The above-mentioned (C) in which the interference blocking sheet and the prism sheet are interchanged. The method of measuring the luminance is to use the combination of each unit and the liquid crystal display as the target object. A luminance meter (Minolta LS-110) was installed at a position one meter away from the object, and the luminance of light was measured (see FIG. 4). Table 1 shows the results.
It was as follows.
【００２４】[0024]
【表１】 [Table 1]
【００２５】この結果、本発明ユニットは、モアレ縞の
発生が皆無で、且つ、輝度も良好で液晶ディスプレイに
邪魔な縞模様の発生がない綺麗で、且つ、明るい画面と
なることが確認された。As a result, it was confirmed that the unit of the present invention had no moiré fringes, had good luminance, and had a clear and bright screen with no disturbing stripes on the liquid crystal display. .
【００２６】[0026]
【実験例２】本発明導光板の３態様を作製し、その位置
と輝度との関係を試験した。３態様とは、下記の
（イ）、（ロ）、（ハ）を指す。 （イ）：アクリル樹脂（住友化学製 ＭＧ−５）を用
い、受光面４ｍｍ、終端面１ｍｍ、光放散面７０ｍｍと
した楔形に形成し、光放散面に高さ２５μｍ、ピッチ５
０μｍの直角二等辺三角形のプリズム構造の凹凸を形成
した導光板。 （ロ）：光放散面に高さ２５μｍ、ピッチ５０μｍの直
角二等辺三角形の間に６μｍの平坦面を等間隔で形成
し、その他は上記（イ）と同条件としたた導光板。 （ハ）：郭形状を、反射面を受光面側から光放散面に４
２ｍｍ平行させた平行面とし、残りを傾斜面とし、その
他は（イ）と同条件とした導光板。 その結果は、図５に示す通りとなった。この結果、
（イ）の導光板は、光源から離れるに従って輝度が低下
するのに対し、（ロ）の導光板は距離６０ｍｍ程度まで
は輝度が略等しく、（ハ）の導光板は距離５０ｍｍ程度
までは輝度が等しく、それより離れると寧ろ輝度が上昇
し、平坦面及び平行面の輝度分布に対する均一の効果が
確認された。EXPERIMENTAL EXAMPLE 2 Three modes of the light guide plate of the present invention were produced, and the relationship between the position and the luminance was tested. The three aspects refer to the following (a), (b), and (c). (A): Acrylic resin (MG-5 manufactured by Sumitomo Chemical Co., Ltd.) was used to form a wedge having a light-receiving surface of 4 mm, a terminal surface of 1 mm, and a light-emitting surface of 70 mm, and a height of 25 μm and a pitch of 5 on the light-emitting surface.
A light guide plate on which irregularities having a prism structure of a right-angled isosceles triangle of 0 μm are formed. (B): A light guide plate in which flat surfaces of 6 μm are formed at regular intervals between right-angled isosceles triangles having a height of 25 μm and a pitch of 50 μm on a light-dissipating surface, and the other conditions are the same as those of the above (a). (C): The shape of the section is changed from the light-receiving surface side to the light-emitting surface by changing the reflection surface to 4
A light guide plate having a parallel surface parallel to 2 mm, the rest being inclined surfaces, and the other conditions being the same as those in (a). The result was as shown in FIG. As a result,
The brightness of the light guide plate of (a) decreases as the distance from the light source increases, whereas the brightness of the light guide plate of (b) is approximately equal up to a distance of about 60 mm, and the brightness of the light guide plate of (c) up to a distance of about 50 mm. Are equal to each other, and the luminance increases when the distance is larger, and a uniform effect on the luminance distribution of the flat surface and the parallel surface is confirmed.
【００２７】[0027]
【発明の効果】叙上の如く本発明は、画面を見づらくす
る要因の一つであるモアレ縞の発生を解消すると共に、
その画面の輝度を高くして明るいものとし、且つ、画面
全体が明暗のない均一な明るさとすることができるとい
う優れた効果を奏する。又、その製造において、導光板
の光放散面にプリズム構造の凹凸を一体成形できるの
で、ユニット全体をコンパクトにすることができるとい
う極めて有利な発明である。As described above, the present invention eliminates the occurrence of moire fringes, which is one of the factors that make it difficult to see the screen,
There is an excellent effect that the brightness of the screen can be increased to make the screen bright, and the entire screen can be made uniform and bright and dark. Also, in the manufacture thereof, since the unevenness of the prism structure can be integrally formed on the light-emitting surface of the light guide plate, the invention is an extremely advantageous invention that the whole unit can be made compact.
【図１】（Ａ）は、本発明導光板ユニットを示す模式的
側面図、（Ｂ）は、その光放散面の一部拡大側面図。FIG. 1A is a schematic side view showing a light guide plate unit of the present invention, and FIG. 1B is a partially enlarged side view of a light diffusion surface thereof.
【図２】（Ａ）本発明の別の態様の導光板を示す模式的
側面図、（Ｂ）は、その光放散面の一部拡大側面図。FIG. 2A is a schematic side view showing a light guide plate according to another embodiment of the present invention, and FIG. 2B is a partially enlarged side view of the light diffusion surface.
【図３】（Ａ）本発明の別の態様の導光板を示す模式的
側面図、（Ｂ）はその光放散面の一部拡大側面図。FIG. 3A is a schematic side view showing a light guide plate according to another embodiment of the present invention, and FIG. 3B is a partially enlarged side view of a light diffusion surface thereof.
【図４】輝度測定用の装置を示す模式的側面図。FIG. 4 is a schematic side view showing a device for measuring luminance.
【図５】試験例２の試験結果を示すグラフ図。FIG. 5 is a graph showing test results of Test Example 2.
【図６】従来の導光板ユニットを示す模式的側面図。FIG. 6 is a schematic side view showing a conventional light guide plate unit.
１ 導光板 ２ 光放散面 ２ａ 平坦面 ３ 反射面 ３ａ 平行面 ３ｂ 傾斜面 ４ 受光面 ５ 液晶ディスプレイ ６ 干渉遮断シ−ト ７ 反射板 ８ 光源 DESCRIPTION OF SYMBOLS 1 Light-guide plate 2 Light-dissipating surface 2a Flat surface 3 Reflecting surface 3a Parallel surface 3b Inclined surface 4 Light-receiving surface 5 Liquid crystal display 6 Interference-blocking sheet 7 Reflector 8 Light source
Claims (4)
のプリズム構造の凹凸に形成した光放散面とし、裏面を
光反射面としたプラスチック導光板を有し、該プリズム
構造の光放射面から放たれた光を散乱させて液晶ディス
プレイとの相互干渉を防止する０．０３〜０．２５ｍｍ
の厚みの干渉遮断シ−トを前記導光板と可及的に近い位
置に配設し、液晶ディスプレイにモアレ縞を発生させる
ことなく光源からの光を照射することを特徴とする導光
板ユニット。1. A plastic light guide plate having a side surface as a light receiving surface, a surface as a light diffusing surface formed with irregularities of a prism structure having a triangular cross section, and a back surface as a light reflecting surface, and a light emitting surface of the prism structure. 0.03 to 0.25 mm to scatter light emitted from the LCD and prevent mutual interference with the liquid crystal display
A light guide plate unit provided with an interference cut-off sheet having a thickness of as close as possible to the light guide plate and irradiating light from a light source without generating moire fringes on the liquid crystal display.
光放射面の表面を断面三角形状のプリズム構造に形成す
ると共に該プリズム構造の間に光源からの光を反射する
平坦面を形成して成る液晶ディスプレイ用導光板ユニッ
ト。2. The plastic light guide plate according to claim 1,
A light guide plate unit for a liquid crystal display, wherein a surface of a light emitting surface is formed in a prism structure having a triangular cross section, and a flat surface for reflecting light from a light source is formed between the prism structures.
その光反射面側を、光源からの光をより遠方に伝播する
平行面と、楔形の傾斜面とに形成して成る液晶ディスプ
レイ用導光板ユニット。3. The plastic light guide plate according to claim 1,
A light guide plate unit for a liquid crystal display, wherein the light reflecting surface side is formed as a parallel surface for transmitting light from a light source to a farther place and a wedge-shaped inclined surface.
光放射面の表面を断面三角形状のプリズム構造に形成す
ると共に該プリズム構造の間に光源からの光を反射する
平坦面を形成し、且つ、その光反射面側を光源からの光
をより遠方に伝播する平行面と楔形の傾斜面とに形成し
て成る液晶ディスプレイ用導光板ユニット。4. The plastic light guide plate according to claim 1,
The surface of the light emitting surface is formed in a prism structure having a triangular cross section, and a flat surface for reflecting light from the light source is formed between the prism structures, and the light reflecting surface side moves light from the light source farther away. A light guide plate unit for a liquid crystal display formed of a parallel plane propagating through a plane and a wedge-shaped inclined plane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8219318A JPH1048428A (en) | 1996-07-31 | 1996-07-31 | Light-guiding plate unit for liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8219318A JPH1048428A (en) | 1996-07-31 | 1996-07-31 | Light-guiding plate unit for liquid crystal display |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1048428A true JPH1048428A (en) | 1998-02-20 |
Family
ID=16733608
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8219318A Pending JPH1048428A (en) | 1996-07-31 | 1996-07-31 | Light-guiding plate unit for liquid crystal display |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1048428A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20010069938A (en) * | 2001-05-21 | 2001-07-25 | 김현주 | A front light apparatus for liquid crystal display of personal digital assistant |
| WO2002025167A1 (en) * | 2000-09-25 | 2002-03-28 | Mitsubishi Rayon Co., Ltd. | Light source device |
| KR20020066788A (en) * | 2001-02-13 | 2002-08-21 | 심충건 | Light Guide Panel in LCD device with a latticed V-extruded type pattern and the manufacturing method of it |
| KR100356991B1 (en) * | 1999-08-19 | 2002-10-18 | 엘지.필립스 엘시디 주식회사 | BackLight Unit |
| JP2003329966A (en) * | 2002-05-14 | 2003-11-19 | Matsushita Electric Ind Co Ltd | Video display device |
| CN100376903C (en) * | 2003-07-12 | 2008-03-26 | 鸿富锦精密工业（深圳）有限公司 | Fabrication method of light conducting plate |
| JP2008243808A (en) * | 2007-02-27 | 2008-10-09 | Seiko Instruments Inc | Lighting device and display device |
| JP2010067568A (en) * | 2008-09-12 | 2010-03-25 | Fujifilm Corp | Light guide plate |
-
1996
- 1996-07-31 JP JP8219318A patent/JPH1048428A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100356991B1 (en) * | 1999-08-19 | 2002-10-18 | 엘지.필립스 엘시디 주식회사 | BackLight Unit |
| WO2002025167A1 (en) * | 2000-09-25 | 2002-03-28 | Mitsubishi Rayon Co., Ltd. | Light source device |
| US7004610B2 (en) | 2000-09-25 | 2006-02-28 | Mitsubishi Rayon Co., Ltd. | Light source device |
| KR20020066788A (en) * | 2001-02-13 | 2002-08-21 | 심충건 | Light Guide Panel in LCD device with a latticed V-extruded type pattern and the manufacturing method of it |
| KR20010069938A (en) * | 2001-05-21 | 2001-07-25 | 김현주 | A front light apparatus for liquid crystal display of personal digital assistant |
| JP2003329966A (en) * | 2002-05-14 | 2003-11-19 | Matsushita Electric Ind Co Ltd | Video display device |
| CN100376903C (en) * | 2003-07-12 | 2008-03-26 | 鸿富锦精密工业（深圳）有限公司 | Fabrication method of light conducting plate |
| JP2008243808A (en) * | 2007-02-27 | 2008-10-09 | Seiko Instruments Inc | Lighting device and display device |
| JP2010067568A (en) * | 2008-09-12 | 2010-03-25 | Fujifilm Corp | Light guide plate |
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