JP2004152496A - Light guide plate - Google Patents

Light guide plate Download PDF

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Publication number
JP2004152496A
JP2004152496A JP2002313115A JP2002313115A JP2004152496A JP 2004152496 A JP2004152496 A JP 2004152496A JP 2002313115 A JP2002313115 A JP 2002313115A JP 2002313115 A JP2002313115 A JP 2002313115A JP 2004152496 A JP2004152496 A JP 2004152496A
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JP
Japan
Prior art keywords
light
guide plate
emitting surface
light guide
light emitting
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Pending
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JP2002313115A
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Japanese (ja)
Inventor
Sumio Nakabashi
純男 中橋
Hirozumi Taguchi
裕純 田口
Nozomi Mifuji
望 美藤
Masaya Suzuki
雅也 鈴木
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Nissen Chemitec Corp
Nippon Chemitec Corp
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Nissen Chemitec Corp
Nippon Chemitec Corp
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Priority to JP2002313115A priority Critical patent/JP2004152496A/en
Publication of JP2004152496A publication Critical patent/JP2004152496A/en
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  • Liquid Crystal (AREA)
  • Planar Illumination Modules (AREA)
  • Light Guides In General And Applications Therefor (AREA)
  • Optical Elements Other Than Lenses (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To establish high luminosity without going against a request for downsizing. <P>SOLUTION: A plurality of protrusions 26 having a directivity are integrally provided on both of a light-emitting surface 10b and a non-light-emitting surface 10c. Each of the protrusions 26 has a part of a spherical surface with a curvature radius r of 5 to 25 μm and with a height or depth of 0.1 to 50 μm, and at least either of the protrusions 26 of the light-emitting surface 10b or the non-light-emitting surface 10c is arranged so that the distribution density per unit area gradually becomes high as it gets away from an incident surface 10a. Since each of the protrusions 26 has a directivity, most of light from a light source 16 is emitted on a liquid crystal display panel 14 without being diffused. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、液晶表示パネルのバックライトに用いられる面型照明装置を構成する導光板に関する。
【０００２】
【従来の技術】
従来の導光板は、光源からの光を取り込む入光面と、入光面から取り込まれた光を液晶表示パネルへ向けて出射する出光面と、出光面に対向する非出光面とを有し、出光面には、光偏向部としての複数の球状突起が形成され、非出光面には、入光面に対して直交する方向へ延びる複数のプリズムが形成されていた（特許文献１参照）。そして、入光面に沿って光源が配置され、出光面に沿って指向性シートおよび拡散シート等が配置されていた。
【０００３】
従来技術によれば、プリズムによって光の方向を制御できるので、液晶表示パネルの高輝度化を図ることができるものの、プリズムによって光の広がりが抑制されるので、導光板の端部においては輝度落ちが生じるという問題があった。
【０００４】
この問題を解決する一手段として、光源の長さを入光面の幅よりも十分に長くすることにより導光板の端部における光量を増大させることが考えられるが、この場合には、小型化の要請に反するという別の問題があった。
【０００５】
【特許文献１】
特開２００２−１３３９３０号公報（図１）
【０００６】
【発明が解決しようとする課題】
それゆえにこの発明の主たる目的は、小型化の要請に反することなく輝度を高めることのできる、導光板を提供することである。
【０００７】
【課題を解決するための手段】
この発明は、「光源１６からの光が入射される入光面１０ａと、入光面１０ａから入射された光が液晶表示パネル１４へ向けて出射される出光面１０ｂと、出光面１０ｂと対向する非出光面１０ｃとを備え、出光面１０ｂおよび非出光面１０ｃの双方に指向性を有する複数の光偏向部２６，２８が一体に設けられた導光板１０において、光偏向部２６，２８のそれぞれは、曲率半径が５〜２５μｍである球面の一部を有し、かつ、高さまたは深さが０．１〜５０μｍであり、出光面１０ｂおよび非出光面１０ｃの少なくとも一方の光偏向部２６は、単位面積当たりの分布密度が入光面１０ａから遠ざかるにつれて高くなるように配置された、導光板１０」である。
【０００８】
この発明によれば、出光面１０ｂおよび非出光面１０ｃの双方に球面の一部を有する複数の光偏向部２６，２８が一体に設けられているので、光偏向部２６，２８の配置や大きさを適切に設定するだけで、出光面１０ｂの全面に亘って輝度を均一にすることができる。また、各光偏向部２６，２８は指向性を有するので、光源１６からの光を効率よく液晶表示パネル１４へ向けて出射することができる。
【０００９】
【発明の実施の形態】
図１および図２を参照して、この発明が適用された導光板１０は、図３に示すような面型照明装置１２の一部を構成するものである。
【００１０】
面型照明装置１２（図３）は、ＴＶ受像機やコンピュータディスプレイなどの液晶表示パネル１４を背面から照射するバックライトとして用いられるものであり、導光板１０，光源１６，リフレクタ１８，反射板２０，導光レンズ２２および拡散板２４によって構成される。
【００１１】
導光板１０（図１，図２）は、透明なアクリル樹脂（ＰＭＭＡ）やポリカーボネート（ＰＣ）等のような透光性材料からなり、その互いに対向する２つの側端面には入光面１０ａが形成され、表面（図１における上面）には出光面１０ｂが形成され、裏面すなわち出光面１０ｂと対向する面（図１における下面）には、非出光面１０ｃが形成される。また、出光面１０ｂおよび非出光面１０ｃの双方には、光を偏向させる機能を有する「光偏向部」としての複数の凸部２６が一体に設けられる。
【００１２】
各凸部２６は、曲率半径ｒが５〜２５μｍである球面の一部を有し、かつ、高さＨが０．１〜５０μｍとなるように形成され、液晶表示パネル１４において広視野角を得るためには各凸部２６の大きさ（曲率半径ｒおよび／または高さＨ；以下同じ。）が小さくされ、高輝度を得るためには各凸部２６の大きさが大きくされる。
【００１３】
ここで、曲率半径ｒを５〜２５μｍの範囲に設定したのは、５μｍより小さければ、光が拡散して指向性が損なわれてしまうからであり、２５μｍより大きければ、凸部２６の周縁部に輝点が生じてしまうからである。また、高さＨを０．１〜５０μｍの範囲に設定したのは、０．１μｍより低ければ、光を偏向させる効果が得られなくなるからであり、５０μｍより高ければ、凸部２６を視認しやすくなり、また、輝度の均一性を得難くなるからである。
【００１４】
また、出光面１０ｂおよび非出光面１０ｃの双方における各凸部２６の分布密度および大きさは、出光面１０ｂの全面において光量が均一となるように設定される。つまり、各凸部２６は、単位面積当たりの分布密度が入光面１０ａから遠ざかるにつれて高くなるように配置され、各凸部２６の大きさは、入光面１０ａから遠ざかるにつれて大きくなるように設定される。したがって、この実施例における各凸部２６の分布密度は、出光面１０ｂおよび非出光面１０ｃのそれぞれの中央部において最も高くなり、各凸部２６の大きさは、出光面１０ｂおよび非出光面１０ｃのそれぞれの中央部において最も大きくなる。
【００１５】
面型照明装置１２を組み立てる際には、図３に示すように、導光板１０が図示しない枠体に固定され、導光板１０の入光面１０ａに沿って冷陰極管等のような光源１６が配置される。また、光源１６を覆うようにしてリフレクタ１８が配置される。そして、導光板１０の非出光面１０ｃに沿って反射板２０が配置され、出光面１０ｂに沿って導光レンズ２２および拡散板２４が層状に配置される。
【００１６】
面型照明装置１２を液晶表示パネル１４の背面に配置して光源１６を点灯すると、光源１６からの光は、直接またはリフレクタ１８を介して入光面１０ａから導光板１０内に入射され、導光板１０の壁面で反射されながら進行する。導光板１０内の光は、導光板１０の壁面に対する入射角が所定条件を満たすときに、壁面を透過して外部へ出射される。
【００１７】
このとき、出光面１０ｂおよび非出光面１０ｃに設けられた各凸部２６に当たった光の多くは、その球面において所定方向へ偏向されるので、すなわち指向性を示すので、拡散されることなく導光板１０の外部へ出射され、または、導光板１０の内部へ反射されることになる。
【００１８】
そして、非出光面１０ｃから出射された光は、反射板２０により反射されて導光板１０内へ戻され、出光面１０ｂから出射された光は、導光レンズ２２および拡散板２４を通して液晶表示パネル１４に照射される。
【００１９】
この実施例によれば、出光面１０ｂおよび非出光面１０ｃの双方に設けられた複数の凸部２６によって出光面１０ｂの全面に亘って輝度を均一にすることができる。したがって、光源１６の長さを入光面１０ａの幅よりも長くする必要はなく、小型化の要請に応えることができる。
【００２０】
また、各凸部２６によって、光源１６からの光を拡散させることなく効率よく液晶表示パネル１４へ与えることができるので、液晶表示パネル１４の高輝度化を達成できる。
【００２１】
そして、各凸部２６は球面の一部を有し、プリズムのような角がないので、傷が付き難く、また、他の部材を傷付ける心配もない。さらに、各凸部２６はブラスト法により得られた凹部を有する中子を用いることによって簡単に成形できるので、プリズムを成形する場合に比べて金型コストを大幅に低減できる。
【００２２】
なお、上述の実施例では、導光レンズ２２および拡散板２４を通して液晶表示パネル１４に光を与えるようにしているが、出光面１０ｂの各凸部２６を小さめに形成した場合には、光の拡散性が高まるので、導光レンズ２２および拡散板２４を省略することができる。この場合でも、光の指向性が完全に損なわれることはなく、輝度が著しく低下する心配はないので、導光レンズ２２および拡散板２４がない分だけ輝度を高めることができる。
【００２３】
また、上述の実施例では、出光面１０ｂおよび非出光面１０ｃの双方において凸部２６の分布密度および大きさを徐々に変化させるようにしているが、たとえば図４に示すように、いずれか一方の凸部２６は、同じ大きさかつ均一分布密度で形成されてもよい。つまり、図４（Ａ）に示すように、非出光面１０ｃの凸部２６が同じ大きさかつ均一分布密度で形成されてもよいし、図４（Ｂ）に示すように、出光面１０ｂの凸部２６が同じ大きさかつ均一分布密度で形成されてもよい。
【００２４】
また、たとえば図５に示すように、全ての凸部２６は、同じ大きさで形成されてもよい。この場合でも、図５（Ａ）に示すように、出光面１０ｂおよび非出光面１０ｃの双方において凸部２６の分布密度が徐々に変化された態様、図５（Ｂ）に示すように、出光面１０ｂにおいてのみ凸部２６の分布密度が徐々に変化された態様、図５（Ｃ）に示すように、非出光面１０ｃにおいてのみ凸部２６の分布密度が徐々に変化された態様をとることができる。
【００２５】
また、たとえば図６に示すように、出光面１０ｂおよび非出光面１０ｃのいずれか一方の凸部２６については分布密度および大きさが徐々に変化され、他方の凸部２６については分布密度のみが徐々に変化されてもよい。つまり、図６（Ａ）に示すように、出光面１０ｂの凸部２６については分布密度および大きさが徐々に変化され、非出光面１０ｃの凸部２６については分布密度のみが徐々に変化されてもよいし、図６（Ｂ）に示すように、出光面１０ｂの凸部２６については分布密度のみが徐々に変化され、非出光面１０ｃの凸部２６については分布密度および大きさが徐々に変化されてもよい。
【００２６】
そして、たとえば図７〜図１０に示すように、凸部２６に代えて凹部２８が「光偏向部」として設けられてもよい。図７の導光板１０は、図１実施例の導光板１０における凸部２６が凹部２８に代えられたものであり、図８の各導光板１０は、図４実施例の各導光板１０における凸部２６が凹部２８に代えられたものである。また、図９の各導光板１０は、図５実施例の各導光板１０における凸部２６が凹部２８に代えられたものであり、図１０の各導光板１０は、図６実施例の各導光板１０における凸部２６が凹部２８に代えられたものである。これらの実施例における各凹部２８は、曲率半径ｒが５〜２５μｍである球面の一部を有し、かつ、深さＨが０．１〜５０μｍとなるように形成される。
【００２７】
そして、図１，図４，図５および図６の各態様において、出光面１０ｂおよび非出光面１０ｃのいずれか一方の各凸部２６が凹部２８に換えられてもよい。
【００２８】
さらに、上述した各実施例では、均一な厚みを有する導光板１０について説明したが、この発明は、図１１に示すような楔形導光板３０についても適用可能である。楔形導光板３０の場合には、厚肉側の端面が入光面３０ａとされ、この入光面３０ａに沿って光源１６が配置される。したがって、楔形導光板３０においては、厚肉側の端部から薄肉側の端部に向かって凸部２６（または凹部２８）の分布密度が徐々に高められ、また、凸部２６（または凹部２８）の大きさが徐々に大きくされる。
【００２９】
楔形導光板３０においても、図４〜図１０と同様に、凸部２６または凹部２８の態様を適宜変更し得ることはいうまでもない。
【００３０】
【発明の効果】
この発明によれば、出光面および非出光面の双方に設けられた複数の光偏向部によって出光面の全面に亘って輝度を均一にすることができる。したがって、光源の長さを入光面の幅よりも長くする必要はなく、小型化の要請に応えることができる。また、指向性を有する各光偏向部によって光源からの光を効率よく液晶表示パネルへ与えることができるので、液晶表示パネルの高輝度化を達成できる。
【図面の簡単な説明】
【図１】この発明の一実施例を示す正面図である。
【図２】図１実施例を示す斜視図である。
【図３】図１実施例の使用状態を示す図である。
【図４】一方の凸部を同じ大きさかつ均一分布密度で形成した状態を示す図である。
【図５】全ての凸部を同じ大きさで形成した状態を示す図である。
【図６】一方の凸部については分布密度のみを変化させた状態を示す図である。
【図７】図１実施例の凸部を凹部に代えた状態を示す図である。
【図８】図４実施例の凸部を凹部に代えた状態を示す図である。
【図９】図５実施例の凸部を凹部に代えた状態を示す図である。
【図１０】図６実施例の凸部を凹部に代えた状態を示す図である。
【図１１】この発明の他の実施例（楔形導光板）を示す図である。
【符号の説明】
１０…導光板
１０ａ…入光面
１０ｂ…出光面
１０ｃ…非出光面
１２…面型照明装置
１４…液晶表示パネル
１６…光源
１８…リフレクタ
２０…反射板
２２…導光レンズ
２４…拡散板
２６…凸部
２８…凹部
３０…楔形導光板[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light guide plate constituting a surface illumination device used for a backlight of a liquid crystal display panel.
[0002]
[Prior art]
A conventional light guide plate has a light incident surface that captures light from a light source, a light exit surface that emits light captured from the light incident surface toward the liquid crystal display panel, and a non-light exit surface that faces the light exit surface. On the light exit surface, a plurality of spherical projections as light deflecting portions are formed, and on the non-light exit surface, a plurality of prisms extending in a direction perpendicular to the light entrance surface are formed (see Patent Document 1). . Then, a light source is arranged along the light incident surface, and a directional sheet, a diffusion sheet and the like are arranged along the light emitting surface.
[0003]
According to the conventional technology, the direction of light can be controlled by the prism, so that the brightness of the liquid crystal display panel can be increased. However, since the spread of the light is suppressed by the prism, the brightness decreases at the end of the light guide plate. There was a problem that occurs.
[0004]
One way to solve this problem is to increase the amount of light at the end of the light guide plate by making the length of the light source sufficiently longer than the width of the light incident surface. There was another problem that was contrary to the request of
[0005]
[Patent Document 1]
JP-A-2002-133930 (FIG. 1)
[0006]
[Problems to be solved by the invention]
Therefore, a main object of the present invention is to provide a light guide plate capable of increasing luminance without violating the demand for miniaturization.
[0007]
[Means for Solving the Problems]
The present invention relates to “a light incident surface 10a on which light from the light source 16 is incident, a light exit surface 10b on which light incident from the light incident surface 10a is emitted toward the liquid crystal display panel 14, and a light exit surface 10b. The light guide plate 10 is provided with a plurality of light deflecting portions 26 and 28 having directivity on both the light emitting surface 10b and the non-light emitting surface 10c. Each of them has a part of a spherical surface having a radius of curvature of 5 to 25 μm, and a height or a depth of 0.1 to 50 μm, and has at least one of the light deflectors of the light exit surface 10 b and the non-light exit surface 10 c. Reference numeral 26 denotes the light guide plate 10 "arranged so that the distribution density per unit area increases as the distance from the light incident surface 10a increases.
[0008]
According to the present invention, since the plurality of light deflecting units 26 and 28 each having a part of the spherical surface are integrally provided on both the light exit surface 10b and the non-light exit surface 10c, the arrangement and size of the light deflection units 26 and 28 are provided. The brightness can be made uniform over the entire surface of the light emitting surface 10b only by setting the distance appropriately. In addition, since each of the light deflecting units 26 and 28 has directivity, light from the light source 16 can be efficiently emitted toward the liquid crystal display panel 14.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to FIGS. 1 and 2, a light guide plate 10 to which the present invention is applied constitutes a part of a surface illumination device 12 as shown in FIG.
[0010]
The surface illumination device 12 (FIG. 3) is used as a backlight for illuminating a liquid crystal display panel 14 such as a TV receiver or a computer display from the back, and includes a light guide plate 10, a light source 16, a reflector 18, and a reflection plate 20. , A light guide lens 22 and a diffusion plate 24.
[0011]
The light guide plate 10 (FIGS. 1 and 2) is made of a translucent material such as transparent acrylic resin (PMMA) or polycarbonate (PC), and has a light incident surface 10a on two opposing side end surfaces. The light emitting surface 10b is formed on the front surface (the upper surface in FIG. 1), and the non-light emitting surface 10c is formed on the back surface, that is, the surface opposite to the light emitting surface 10b (the lower surface in FIG. 1). A plurality of convex portions 26 as “light deflecting portions” having a function of deflecting light are integrally provided on both the light emitting surface 10b and the non-light emitting surface 10c.
[0012]
Each convex portion 26 has a part of a spherical surface having a radius of curvature r of 5 to 25 μm, and is formed so that the height H is 0.1 to 50 μm. The size of each convex portion 26 (the radius of curvature r and / or the height H; the same applies hereinafter) is reduced in order to obtain, and the size of each convex portion 26 is increased in order to obtain high luminance.
[0013]
The reason why the radius of curvature r is set in the range of 5 to 25 μm is that if the radius is smaller than 5 μm, light is diffused and the directivity is impaired. This is because a bright spot is generated. The reason why the height H is set in the range of 0.1 to 50 μm is that if the height H is lower than 0.1 μm, the effect of deflecting the light cannot be obtained. This is because it becomes difficult to obtain uniformity of luminance.
[0014]
The distribution density and size of each convex portion 26 on both the light emitting surface 10b and the non-light emitting surface 10c are set such that the light amount is uniform over the entire light emitting surface 10b. That is, each convex portion 26 is arranged such that the distribution density per unit area increases as the distance from the light incident surface 10a increases, and the size of each convex portion 26 is set to increase as the distance from the light incident surface 10a increases. Is done. Therefore, the distribution density of each projection 26 in this embodiment is highest at the center of each of the light exit surface 10b and the non-light exit surface 10c, and the size of each projection 26 is the light exit surface 10b and the non-light exit surface 10c. Is largest at the center of each of them.
[0015]
When assembling the surface illumination device 12, as shown in FIG. 3, the light guide plate 10 is fixed to a frame (not shown), and a light source 16 such as a cold cathode tube or the like is arranged along the light incident surface 10 a of the light guide plate 10. Is arranged. Further, a reflector 18 is arranged so as to cover the light source 16. Then, the reflection plate 20 is arranged along the non-light emitting surface 10c of the light guide plate 10, and the light guide lens 22 and the diffusion plate 24 are arranged in layers along the light emission surface 10b.
[0016]
When the light source 16 is turned on by arranging the surface illumination device 12 on the back of the liquid crystal display panel 14, light from the light source 16 is incident on the light guide plate 10 from the light incident surface 10 a directly or via the reflector 18 to guide the light. The light travels while being reflected by the wall surface of the light plate 10. When the incident angle with respect to the wall surface of the light guide plate 10 satisfies a predetermined condition, the light in the light guide plate 10 passes through the wall surface and is emitted to the outside.
[0017]
At this time, most of the light hitting each of the convex portions 26 provided on the light emitting surface 10b and the non-light emitting surface 10c is deflected in a predetermined direction on its spherical surface, that is, since it shows directivity, it is not diffused. The light is emitted outside the light guide plate 10 or is reflected inside the light guide plate 10.
[0018]
The light emitted from the non-light-emitting surface 10c is reflected by the reflection plate 20 and returned into the light guide plate 10, and the light emitted from the light-emitting surface 10b passes through the light guide lens 22 and the diffusion plate 24. 14 is irradiated.
[0019]
According to this embodiment, the luminance can be made uniform over the entire surface of the light emitting surface 10b by the plurality of convex portions 26 provided on both the light emitting surface 10b and the non-light emitting surface 10c. Therefore, it is not necessary to make the length of the light source 16 longer than the width of the light incident surface 10a, and it is possible to meet the demand for downsizing.
[0020]
In addition, since the light from the light source 16 can be efficiently given to the liquid crystal display panel 14 without being diffused by the respective convex portions 26, high brightness of the liquid crystal display panel 14 can be achieved.
[0021]
Each projection 26 has a part of a spherical surface and has no corner like a prism, so that it is not easily damaged and there is no fear of damaging other members. Furthermore, since each convex portion 26 can be easily formed by using a core having a concave portion obtained by a blast method, the die cost can be significantly reduced as compared with the case of forming a prism.
[0022]
In the above-described embodiment, light is applied to the liquid crystal display panel 14 through the light guide lens 22 and the diffusion plate 24. However, when each of the convex portions 26 of the light output surface 10b is formed to be small, light is not transmitted. Since the diffusivity is enhanced, the light guide lens 22 and the diffusion plate 24 can be omitted. Also in this case, the directivity of light is not completely impaired, and there is no fear that the luminance is significantly reduced. Therefore, the luminance can be increased by the absence of the light guide lens 22 and the diffusion plate 24.
[0023]
Further, in the above-described embodiment, the distribution density and the size of the convex portions 26 are gradually changed on both the light emitting surface 10b and the non-light emitting surface 10c. For example, as shown in FIG. May be formed with the same size and uniform distribution density. That is, as shown in FIG. 4A, the convex portions 26 of the non-light emitting surface 10c may be formed with the same size and uniform distribution density, or as shown in FIG. The protrusions 26 may be formed with the same size and uniform distribution density.
[0024]
Further, for example, as shown in FIG. 5, all the protrusions 26 may be formed in the same size. Also in this case, as shown in FIG. 5A, the distribution density of the convex portions 26 is gradually changed on both the light emitting surface 10b and the non-light emitting surface 10c. As shown in FIG. A mode in which the distribution density of the convex portions 26 is gradually changed only on the surface 10b, and a mode in which the distribution density of the convex portions 26 is gradually changed only on the non-light emitting surface 10c as shown in FIG. Can be.
[0025]
Further, as shown in FIG. 6, for example, the distribution density and the size of one of the convex portions 26 of the light emitting surface 10b and the non-light emitting surface 10c are gradually changed, and only the distribution density of the other convex portion 26 is changed. It may be changed gradually. That is, as shown in FIG. 6A, the distribution density and the size of the projection 26 of the light emitting surface 10b are gradually changed, and only the distribution density of the projection 26 of the non-light emitting surface 10c is gradually changed. Alternatively, as shown in FIG. 6B, only the distribution density of the convex portion 26 of the light emitting surface 10b is gradually changed, and the distribution density and size of the convex portion 26 of the non-light emitting surface 10c are gradually increased. May be changed to
[0026]
For example, as shown in FIGS. 7 to 10, a concave portion 28 may be provided as a “light deflecting portion” instead of the convex portion 26. The light guide plate 10 of FIG. 7 is obtained by replacing the convex portions 26 of the light guide plate 10 of FIG. 1 with the concave portions 28, and each light guide plate 10 of FIG. The protrusion 26 is replaced with a recess 28. Further, each light guide plate 10 of FIG. 9 is obtained by replacing the convex portion 26 in each light guide plate 10 of FIG. 5 with a concave portion 28, and each light guide plate 10 of FIG. The projection 26 in the light guide plate 10 is replaced with a depression 28. Each concave portion 28 in these embodiments has a part of a spherical surface having a radius of curvature r of 5 to 25 μm and is formed such that the depth H is 0.1 to 50 μm.
[0027]
In each of the embodiments shown in FIGS. 1, 4, 5, and 6, each of the convex portions 26 of one of the light emitting surface 10b and the non-light emitting surface 10c may be replaced with a concave portion 28.
[0028]
Further, in each of the embodiments described above, the light guide plate 10 having a uniform thickness has been described, but the present invention is also applicable to a wedge-shaped light guide plate 30 as shown in FIG. In the case of the wedge-shaped light guide plate 30, the end face on the thick side is a light incident surface 30a, and the light source 16 is arranged along the light incident surface 30a. Therefore, in the wedge-shaped light guide plate 30, the distribution density of the protrusions 26 (or the recesses 28) is gradually increased from the thicker end to the thinner end, and the protrusions 26 (or the recesses 28) are increased. ) Is gradually increased.
[0029]
In the wedge-shaped light guide plate 30 as well, as in FIGS. 4 to 10, it goes without saying that the shape of the convex portion 26 or the concave portion 28 can be appropriately changed.
[0030]
【The invention's effect】
According to the present invention, the brightness can be made uniform over the entire surface of the light emitting surface by the plurality of light deflecting units provided on both the light emitting surface and the non-light emitting surface. Therefore, it is not necessary to make the length of the light source longer than the width of the light incident surface, and it is possible to meet the demand for miniaturization. In addition, since the light from the light source can be efficiently supplied to the liquid crystal display panel by each of the light deflecting units having directivity, high brightness of the liquid crystal display panel can be achieved.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of the present invention.
FIG. 2 is a perspective view showing the embodiment of FIG. 1;
FIG. 3 is a diagram showing a use state of the embodiment in FIG. 1;
FIG. 4 is a diagram showing a state in which one convex portion is formed with the same size and a uniform distribution density.
FIG. 5 is a view showing a state in which all convex portions are formed in the same size.
FIG. 6 is a diagram showing a state in which only the distribution density of one of the protrusions is changed.
FIG. 7 is a diagram showing a state in which a convex portion is replaced with a concave portion in the embodiment of FIG. 1;
FIG. 8 is a view showing a state in which a convex portion is replaced with a concave portion in the embodiment of FIG. 4;
FIG. 9 is a diagram showing a state in which a convex portion is replaced with a concave portion in the embodiment of FIG. 5;
FIG. 10 is a view showing a state in which a convex portion is replaced with a concave portion in the embodiment of FIG. 6;
FIG. 11 is a view showing another embodiment (wedge-shaped light guide plate) of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Light guide plate 10a ... Light entrance surface 10b ... Light exit surface 10c ... Non-light exit surface 12 ... Surface illumination device 14 ... Liquid crystal display panel 16 ... Light source 18 ... Reflector 20 ... Reflection plate 22 ... Light guide lens 24 ... Diffusion plate 26 ... Convex part 28 ... Concave part 30 ... Wedge-shaped light guide plate

Claims (1)

光源からの光が入射される入光面と、前記入光面から入射された光が液晶表示パネルへ向けて出射される出光面と、前記出光面と対向する非出光面とを備え、前記出光面および前記非出光面の双方に指向性を有する複数の光偏向部が一体に設けられた導光板であって、
前記光偏向部のそれぞれは、曲率半径が５〜２５μｍである球面の一部を有し、かつ、高さまたは深さが０．１〜５０μｍであり、前記出光面および前記非出光面の少なくとも一方の前記光偏向部は、単位面積当たりの分布密度が前記入光面から遠ざかるにつれて高くなるように配置された、導光板。A light incident surface on which light from a light source is incident, a light exit surface on which light incident from the light incident surface is emitted toward a liquid crystal display panel, and a non-light exit surface facing the light exit surface; A light guide plate integrally provided with a plurality of light deflecting units having directivity on both the light exit surface and the non-light exit surface,
Each of the light deflecting units has a part of a spherical surface having a radius of curvature of 5 to 25 μm, and a height or a depth of 0.1 to 50 μm, and at least the light emitting surface and the non-light emitting surface. The light guide plate, wherein the one light deflecting unit is arranged so that a distribution density per unit area increases as the distance from the light incident surface increases.
JP2002313115A 2002-10-28 2002-10-28 Light guide plate Pending JP2004152496A (en)

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WO2006001383A1 (en) * 2004-06-24 2006-01-05 Olympus Corporation Video display and vehicle-mounted video display
KR100677151B1 (en) 2004-10-22 2007-02-02 삼성전자주식회사 Back light unit and liquid display apparatus employing it
JP2007101567A (en) * 2005-03-03 2007-04-19 Taesan Lcd Co Ltd Manufacturing method of stamper for manufacturing light transmission plate and manufacturing method of light transmission plate
KR100806133B1 (en) 2006-08-29 2008-02-22 신화인터텍 주식회사 Diffuse sheet and backlight assembly and liquid crystal display comprising the same
WO2008153254A1 (en) * 2007-06-12 2008-12-18 Cheil Industries Inc. Light guide panel comprising symmetric front prism and asymmetric front prism for back light unit of lcd
CN102183810A (en) * 2011-04-26 2011-09-14 深圳市华星光电技术有限公司 Light guide plate and backlight module thereof
JP2012049051A (en) * 2010-08-30 2012-03-08 Skg:Kk Lighting system
JP2014006547A (en) * 2006-05-18 2014-01-16 3M Innovative Properties Co Method for making light guides having extraction structures, and light guides produced by said method
TWI461766B (en) * 2011-12-09 2014-11-21 Skc Haas Display Films Co Ltd Light guide plates having a two-dimensional pattern comprising substantially identical micro-lenses
JP2018013306A (en) * 2016-07-22 2018-01-25 日立アプライアンス株式会社 Display device and refrigerator including the same
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Cited By (20)

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JP2006010935A (en) * 2004-06-24 2006-01-12 Olympus Corp Video display device and on-vehicle video display device
US7800710B2 (en) 2004-06-24 2010-09-21 Olympus Corporation Image display apparatus and in-vehicle image display apparatus
WO2006001383A1 (en) * 2004-06-24 2006-01-05 Olympus Corporation Video display and vehicle-mounted video display
KR100677151B1 (en) 2004-10-22 2007-02-02 삼성전자주식회사 Back light unit and liquid display apparatus employing it
JP2007101567A (en) * 2005-03-03 2007-04-19 Taesan Lcd Co Ltd Manufacturing method of stamper for manufacturing light transmission plate and manufacturing method of light transmission plate
JP2014006547A (en) * 2006-05-18 2014-01-16 3M Innovative Properties Co Method for making light guides having extraction structures, and light guides produced by said method
US9329326B2 (en) 2006-05-18 2016-05-03 3M Innovative Properties Company Process for making light guides with extraction structures and light guides produced thereby
KR100806133B1 (en) 2006-08-29 2008-02-22 신화인터텍 주식회사 Diffuse sheet and backlight assembly and liquid crystal display comprising the same
US8823632B2 (en) 2007-06-12 2014-09-02 Cheil Industries, Inc. Light guide panel comprising symmetric front prism and asymmetric front prism for back light unit of LCD
WO2008153254A1 (en) * 2007-06-12 2008-12-18 Cheil Industries Inc. Light guide panel comprising symmetric front prism and asymmetric front prism for back light unit of lcd
JP2012049051A (en) * 2010-08-30 2012-03-08 Skg:Kk Lighting system
CN102183810A (en) * 2011-04-26 2011-09-14 深圳市华星光电技术有限公司 Light guide plate and backlight module thereof
TWI461766B (en) * 2011-12-09 2014-11-21 Skc Haas Display Films Co Ltd Light guide plates having a two-dimensional pattern comprising substantially identical micro-lenses
JP2018013306A (en) * 2016-07-22 2018-01-25 日立アプライアンス株式会社 Display device and refrigerator including the same
CN107642943A (en) * 2016-07-22 2018-01-30 日立空调·家用电器株式会社 Display device and the refrigerator for possessing the display device
CN107644601A (en) * 2016-07-22 2018-01-30 日立空调·家用电器株式会社 Display device and the refrigerator for possessing the display device
CN110709758A (en) * 2017-05-11 2020-01-17 镭亚股份有限公司 Microstructured multibeam element backlight
JP2020520055A (en) * 2017-05-11 2020-07-02 レイア、インコーポレイテッドＬｅｉａ Ｉｎｃ． Backlighting of microstructured multi-beam elements
US11204457B2 (en) 2017-05-11 2021-12-21 Leia Inc. Microstructured multibeam element backlighting
CN109188597A (en) * 2018-11-01 2019-01-11 佛山市顺德区德联邦盛光电科技有限公司 It is a kind of to exempt from silk-screen light guide plate with improvement micro nano structure

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