JP4256540B2 - Surface light source device - Google Patents

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JP4256540B2
JP4256540B2 JP21997999A JP21997999A JP4256540B2 JP 4256540 B2 JP4256540 B2 JP 4256540B2 JP 21997999 A JP21997999 A JP 21997999A JP 21997999 A JP21997999 A JP 21997999A JP 4256540 B2 JP4256540 B2 JP 4256540B2
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guide plate
light guide
planar
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light source
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JP2001052521A (en
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久士 太田
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Mitsubishi Electric Corp
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Description

【０００１】
【発明の属する技術分野】
本発明は面状光源装置に関する。さらに詳しくは、液晶表示装置用のバックライトなどに用いられる面状光源装置に関する。
【０００２】
【従来の技術】
従来より、図１０〜１１に示されるように、透光性材料からなる導光板２１の周端面における入光面２１ａに近接して棒状光源であるランプ２３が配設され、前記導光板２１およびランプ２３がモールドフレーム２２に収納および保持されたサイドライト型面状光源装置がある。
【０００３】
この面状光源装置は、棒状光源として冷陰極管または熱陰極管などのランプ２３が使用され、ランプ２３を透過率の高いアクリル樹脂などの材料で作製された導光板２１の上面に近接して配設し、ランプ２３からの光を均一にすることを目的とした光散乱効果を有する白色合成樹脂板からなる拡散シートが設けられ、また、拡散シートの反対側には鏡面反射または白色反射板が用いられており、かかる反射シートはランプ２３から導光板２１に入った光のうち、後面側に向かう光を前面側に反射させて光の利用効率を向上させている。
【０００４】
また、面状光源装置の構成部品のうち、ランプ２３および導光板２１の位置関係は、発光面の輝度に著しく影響を及ぼすため、ランプ２３および導光板２１は、硬質のモールドフレーム２２により位置決めされている。従来では、導光板２１を位置決めする場合には、導光板２１の側端面２１ｂに凸型の突起２７を形成し、モールドフレーム２２側に凹部２８を成形することにより、位置決め機能をもたせている。
【０００５】
また、図１０〜１１に示される面状光源装置は、モールドフレーム２２の一辺にランプラバー２４によってランプ２３が固着され、ランプ２３の外周にはランプリフレクタ３３が前記導光板２１を向く方向だけ開口するように覆い、ランプ２３の両端からのびるランプケーブル２５はモールドフレーム２２外部でランプ用コネクタ２６に接続されている。
【０００６】
また、導光板２１の前面側（図１０において上側）には、レンズシート３２および液晶パネル２９が下から順に配設され、さらに液晶パネル２９の前側周縁付近の部分はフロントフレーム３１で覆われている。さらに液晶パネル２９はテープ配線などを介して制御基板３０に電気的に接続されている。
【０００７】
【発明が解決しようとする課題】
従来より、液晶表示装置用バックライトとして用いられる面状光源装置では、発光面全体の輝度の均一性が要求されている。発光面全体を均一に発光させるためには、導光板２１の形状は発光面側から見て側端面２１ｂの辺は単純な構造であることが望ましい。しかし、従来の導光板２１のように位置決めのための凸型形状の突起２７を設けるなど、構造が複雑化するとその近傍における輝度均一性が損なわれ、画質の低下を招く。
【０００８】
また、凸型形状などの複雑な構造は導光板２１を成形するうえで成形を困難にする要因になる。
【０００９】
さらに、導光板２１をモールドフレーム２２に組み付ける場合、一対の凸型形状の突起２７を凹部２８にうまくはめ込む必要があり、熟練を要するとともに手間がかかるという問題がある。
【００１０】
また、液晶表示装置は、情報化社会の進展に伴い、ノートブックタイプのパソコン、ワープロなどの情報処理装置も軽量化および薄型化が指向され、携帯可能なものが市場で望まれている。そこで表示には関係ない額縁、すなわちモールドフレーム２２の狭額縁化、部品の高密度化の傾向にある。導光板２１の位置決めを目的とした凸型形状の突起２７の幅も狭額縁化の影響により小型化の傾向がある。従来のように小型の耳状を呈する前記突起２７で導光板２１の位置決めを行なうと、液晶表示装置を持ち運んだ際に落下などの理由により衝撃が加わったときに凸型形状の突起２７の根元部分に応力集中がかかり、導光板２１のかかる根元付近の部分に割れが生じ、表示に影響を及ぼすことがある。
【００１１】
本発明はかかる問題を解消するためになされたものであり、輝度が均一であり、製造が容易であり、導光板の組付けが容易であり、しかも耐衝撃性にすぐれた面状光源装置を提供する。
【００１２】
【課題を解決するための手段】
本発明の請求項１にかかわる面状光源装置は、透光性材料からなる導光板と、該導光板の周端面に形成された入光面に近接して配設された棒状光源と、前記導光板の周端面のうち前記入光面の両側にのびる一対の側端面を保持するフレームとからなる面状光源装置であって、
前記導光板の平面形状が、前記一対の側端面の全体が前記入光面に対して傾斜した形状であって、さらに前記一対の側端面は、前記入光面の方向に向って該一対の側端面間が狭くなるように傾斜した部分をもつ形状を呈し、
前記フレームの空間部が、前記導光板の平面形状に実質的に相補的な形状を呈してなることを特徴とする。
【００１３】
前記導光板の平面形状が、前記入光面に対向する終端面を底辺とする台形を呈してなるのが好ましい。
【００１７】
前記導光板の平面形状が、前記一対の側端面のほぼ中間位置で外方へ屈曲した六角形を呈してなるのが好ましい。
【００１８】
前記導光板の平面形状が、前記一対の側端面のほぼ中間位置で内方へ屈曲した六角形を呈してなるのが好ましい。
【００１９】
本発明の請求項５にかかわる面状光源装置は、透光性材料からなる導光板と、該導光板の周端面に形成された入光面に近接して配設された棒状光源と、前記導光板の周端面のうち前記入光面の両側にのびる一対の側端面を保持するフレームとからなる面状光源装置であって、
前記導光板の平面形状が、前記一対の側端面の全体が前記入光面に対して湾曲した形状であって、さらに前記一対の側端面は、前記入光面の方向に向って該一対の側端面間が狭くなるように湾曲した部分をもつ形状を呈し、
前記フレームの空間部が、前記導光板の平面形状に実質的に相補的な形状を呈してなることを特徴とする。
【００２０】
前記導光板の平面形状が、前記一対の側端面が内方へ湾曲した形状を呈してなるのが好ましい。
【００２１】
前記導光板の平面形状が、前記一対の側端面が外方へ湾曲した形状を呈してなるのが好ましい。
【００２２】
本発明の請求項８にかかわる面状光源装置は、透光性材料からなる導光板と、該導光板の周端面に形成された入光面に近接して配設された棒状光源と、前記導光板の周端面のうち前記入光面の両側にのびる一対の側端面を保持するフレームとからなる面状光源装置であって、
前記導光板の平面形状が、前記一対の側端面全体が略波形形状を呈し、
前記フレームの空間部が、前記導光板の平面形状に実質的に相補的な形状を呈してなることを特徴とする。
【００２３】
【発明の実施の形態】
つぎに図面を参照しながら本発明の面状光源装置をさらに詳細に説明する。図１は本発明の面状光源装置の一実施の形態を示す台形形状の導光板を有する面状光源装置を備えた液晶表示装置の分解斜視説明図、図２は図１の面状光源装置の平面説明図、図３は参考例にかかわる面状光源装置を示す逆台形形状の導光板を有する面状光源装置の平面説明図、図４は参考例にかかわる面状光源装置を示す平行四辺形形状の導光板を有する面状光源装置の平面説明図、図５は参考例にかかわる面状光源装置を示す側端面が外方へ屈曲した六角形形状の導光板を有する面状光源装置の平面説明図、図６は本発明の面状光源装置のさらに他の実施の形態を示す側端面が内方へ屈曲した六角形形状の導光板を有する面状光源装置の平面説明図、図７は本発明の面状光源装置のさらに他の実施の形態を示す側端面が内方へ湾曲した形状の導光板を有する面状光源装置の平面説明図、図８は本発明の面状光源装置のさらに他の実施の形態を示す側端面が外方へ湾曲した形状の導光板を有する面状光源装置の平面説明図および図９は本発明の面状光源装置のさらに他の実施の形態を示す側端面全体が略波形形状の導光板を有する面状光源装置の平面説明図である。
【００２４】
図１〜２に示される本実施の形態の面状光源装置は、透光性材料からなる導光板１の周端面における入光面１ａに近接して棒状光源であるランプ３が配設され、前記導光板１およびランプ３がモールドフレーム２に収納および保持されている。導光板１の平面形状は、一対の側端面１ｂの全体が入光面１ａに対して傾斜した形状を呈しており、一方、フレーム２の空間部は、導光板１の平面形状に実質的に相補的な形状を呈している。
【００２５】
図２に示されるように、導光板１は、従来の位置決め用突起２７（図１０〜１１参照）がない比較的シンプルな形状であるため、均一な輝度で導光板１の前面から発光することができる。また、導光板１がシンプルな形状であるため、成形が容易であり、かつ、導光板１を容易にモールドフレーム２に組み付けることができる。
【００２６】
また、図２に示されるように、ランプ３側を上になるように液晶表示装置を置いた場合、導光板１は側端面１ｂおよび終端面１ｃで位置決めされており、上下方向の導光板１の動きを抑制することができる。
【００２７】
しかも、側端面１ｂの全体は、傾斜して直線状にのびているので、側端面１ｂ全体でモールドフレーム２に当接することによって導光板１にかかる荷重（静荷重または衝撃荷重など）を分散して受けることができる。したがって、導光板１は、応力集中する部分がないため、破損しにくくなる。
【００２８】
さらに、図２に示される導光板１の平面形状は、入光面１ａに対向する終端面１ｃを底辺とする台形を呈しているため、導光板１がランプ３へ向かって移動しようとしても、終端面１ｃが入光面１ａよりも長いため、導光板１がランプ３側から滑り出ることがない。
【００２９】
図２の台形形状の導光板１の場合、入光面１ａに対する側端面１ｂの角度θ1は、９０°＜θ1≦１００°程度（好ましくは９３．８°）の範囲に設定されていれば、通常のモジュール（アスペクト比が縦：横＝３：４の場合）でも入光面１ａと終端面１ｃとの辺の比率が１：１．２５を超えないので、狭額縁化を達成できる。
【００３０】
前記図１〜２の面状光源装置は、従来と同様に、棒状光源として冷陰極管または熱陰極管などのランプ３が使用され、ランプ３を透過率の高いアクリル樹脂などの材料で作製された導光板１に近接して配設し、ランプ３からの光を均一にすることを目的とした光散乱効果を有する白色合成樹脂板からなる拡散シートが設けられ、また、拡散シートの反対側には鏡面反射または白色反射板が用いられており、かかる反射シートはランプ３から導光板１に入った光のうち、後面側に向かう光を前面側に反射させて光の利用効率を向上させている。
【００３１】
また、図１〜２に示される面状光源装置は、モールドフレーム２の一辺にランプラバー４によってランプ３が固着され、ランプ３の外周にはランプリフレクタ１３が前記導光板１を向く方向だけ開口するように覆い、ランプ３の両端からのびるランプケーブル５はモールドフレーム２外部でランプ用コネクタ６に接続されている。
【００３２】
また、導光板１の前面側（図１において上側）には、レンズシート１２および液晶パネル９が下から順に配設され、さらに液晶パネル９の前側周縁付近の部分はフロントフレーム１１で覆われている。さらに液晶パネル９はテープ配線などを介して制御基板１０に電気的に接続されている。
【００３３】
前記実施の形態では、側端面１ｂ全体が傾斜した形状の一例として、図２に示される終端面１ｃを底辺とする台形形状を例にあげて説明したが，本発明はこれに限定されるものではなく、図３に示されるような、導光板１の平面形状が、入光面１ａを底辺とする台形形状であってもよい。
【００３４】
図３の導光板１は、図１と同様に入光面１ａから終端面１ｃへ向かうにつれてだんだん薄くなる構造なので、最も薄い終端面１ｃの両端の角度が９０°よりも大きくなることにより導光板１の破損が少ないという利点を有する。
【００３５】
また、図４に示されるように、導光板１の平面形状が、平行四辺形を呈してなる形状でも前記実施の形態と同様の作用を奏することができる。図４の場合、入光面１ａに対する側端面１ｂの角度θ3は９０°＜θ3≦１００°程度（好ましくは９３．８°）または８０°≦θ3＜９０°（好ましくは８６．２°）程度のいずれかの範囲であれば、図２の場合と同様に狭額縁化を達成することができる。
【００３６】
前記図３〜４の場合、導光板１の内側において、導光板１とランプ３とのあいだに、導光板１の入光面１ａを受けるための受け部７が設けられているため、導光板１がランプ３へ移動するのを好適に防止できる。
【００３７】
また、図５に示されるように、導光板１の平面形状が、一対の側端面１ｂのほぼ中間位置で外方へ屈曲した六角形を呈してなる形状でも前記実施の形態と同様の作用を奏することができる。図５の場合、入光面１ａに対する側端面１ｂの角度θ4は９０°＜θ4≦１０８°程度（好ましくは９７．６°）の範囲であれば、図２の場合と同様に狭額縁化を達成することができる。
【００３８】
また、図６に示されるように、導光板１の平面形状が、一対の側端面１ｂのほぼ中間位置で内方へ屈曲した六角形を呈してなる形状でも前記実施の形態と同様の作用を奏することができる。図６の場合、入光面１ａに対する側端面１ｂの角度θ5は７２°＜θ5≦９０°程度（好ましくは８６．２°）の範囲であれば、図２の場合と同様に狭額縁化を達成することができる。
【００３９】
また、本発明の請求項５にかかわる発明の一実施の形態として、図７〜８に示されるように、透光性材料からなる導光板１の周端面における入光面１ａに近接して棒状光源であるランプ３が配設され、前記導光板１およびランプ３がモールドフレーム２に収納および保持され、導光板１の平面形状が、一対の側端面１ｂの全体が入光面１ａに対して内方または外方へ湾曲した形状を呈し、モールドフレーム２の空間部が、導光板１の平面形状に実質的に相補的な形状を呈していてもよい。この場合も、前記実施の形態と同様に、輝度の均一性、成形容易性、組付容易性および耐衝撃性の向上を達成することができる。
【００４０】
図７に示されるように、一対の側端面１ｂの全体が入光面１ａに対して内方へ湾曲した形状を呈する場合、導光板１の幅の比率がＸ11：Ｘ12＝１．１：１より小さい比率であれば、狭額縁化を達成することができる。
【００４１】
一方、図８に示されるように、一対の側端面１ｂの全体が入光面１ａに対して外方へ湾曲した形状を呈する場合、導光板１の端部と中間部における幅の比率がＸ21：Ｘ22＝１：１．１より小さい比率であれば、狭額縁化を達成することができる。
【００４２】
さらに、本発明の請求項８にかかわる発明の一実施の形態として、図９に示されるように、透光性材料からなる導光板１の周端面における入光面１ａに近接して棒状光源であるランプ３が配設され、前記導光板１およびランプ３がモールドフレーム２に収納および保持され、導光板１の平面形状が、一対の側端面１ｂの全体が略波形形状を呈し、モールドフレーム２の空間部が、導光板１の平面形状に実質的に相補的な形状を呈する場合でも、前記実施の形態と同様に、輝度の均一性、成形容易性、組付容易性および耐衝撃性の向上を達成することができる。図９の場合、導光板１の端部と中間部における幅の比率がＸ31：Ｘ32＝１：１．１より小さい比率であれば、狭額縁化を達成することができる。
【００４３】
なお、図９に示される略波形形状は、場所によって、Ｘ31、Ｘ32のように幅が異なっているが、一対の側端面１ｂの起伏の周期を一致させて幅を一定にさせた場合でも図９の場合と同様の効果を得ることができる。
【００４４】
以上の図２〜９の場合、ランプ３が上側に配置されているが、本発明はこれに限定されるものではなく、他の３辺のいずれの場合にも適用可能である。また、対向する２辺（入光面１ａおよび終端面１ｃの両方）にランプ３を有する複数灯方式のものにも適用可能である。
【００４５】
【発明の効果】
本発明によれば、導光板の側端面から突起を省略して当該側端面全体によって導光板を支持するため、輝度が均一であり、製造が容易であり、導光板の組付けが容易であり、しかも耐衝撃性にすぐれている。
【図面の簡単な説明】
【図１】 本発明の面状光源装置の一実施の形態を示す台形形状の導光板を有する面状光源装置を備えた液晶表示装置の分解斜視説明図である。
【図２】 図１の面状光源装置の平面説明図である。
【図３】 参考例にかかわる面状光源装置を示す逆台形形状の導光板を有する面状光源装置の平面説明図である。
【図４】 参考例にかかわる面状光源装置を示す平行四辺形形状の導光板を有する面状光源装置の平面説明図である。
【図５】 参考例にかかわる面状光源装置を示す側端面が外方へ屈曲した六角形形状の導光板を有する面状光源装置の平面説明図である。
【図６】 本発明の面状光源装置のさらに他の実施の形態を示す側端面が内方へ屈曲した六角形形状の導光板を有する面状光源装置の平面説明図である。
【図７】 本発明の面状光源装置のさらに他の実施の形態を示す側端面が内方へ湾曲した形状の導光板を有する面状光源装置の平面説明図である。
【図８】 本発明の面状光源装置のさらに他の実施の形態を示す側端面が外方へ湾曲した形状の導光板を有する面状光源装置の平面説明図である。
【図９】 本発明の面状光源装置のさらに他の実施の形態を示す側端面全体が略波形形状の導光板を有する面状光源装置の平面説明図である。
【図１０】 従来の面状光源装置を備えた液晶表示装置の分解斜視図である。
【図１１】 図１０の面状光源装置の平面図である。
【符号の名称】
１ 導光板
２ モールドフレーム
３ ランプ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a planar light source device. More specifically, the present invention relates to a planar light source device used for a backlight for a liquid crystal display device.
[0002]
[Prior art]
Conventionally, as shown in FIGS. 10 to 11, a lamp 23, which is a rod-shaped light source, is disposed in the vicinity of the light incident surface 21 a on the peripheral end surface of the light guide plate 21 made of a light transmissive material. There is a side light type planar light source device in which a lamp 23 is housed and held in a mold frame 22.
[0003]
In this planar light source device, a lamp 23 such as a cold cathode tube or a hot cathode tube is used as a rod-like light source, and the lamp 23 is close to the upper surface of the light guide plate 21 made of a material such as acrylic resin having a high transmittance. disposed, the diffusion sheet made of white synthetic resin plate is provided with a light scattering effect for the purpose of a uniform light from the lamp 23, also specular or white reflector on the opposite side of the diffusion sheet The reflecting sheet reflects light traveling toward the rear side out of the light entering the light guide plate 21 from the lamp 23 to the front side to improve the light utilization efficiency.
[0004]
In addition, among the components of the planar light source device, the positional relationship between the lamp 23 and the light guide plate 21 significantly affects the luminance of the light emitting surface, so the lamp 23 and the light guide plate 21 are positioned by the hard mold frame 22. ing. Conventionally, when positioning the light guide plate 21, a convex projection 27 is formed on the side end surface 21 b of the light guide plate 21, and a recess 28 is formed on the mold frame 22 side to provide a positioning function.
[0005]
10 to 11, a lamp 23 is fixed to one side of a mold frame 22 by a lamp rubber 24, and a lamp reflector 33 is opened on the outer periphery of the lamp 23 only in a direction facing the light guide plate 21. The lamp cable 25 extending from both ends of the lamp 23 is connected to the lamp connector 26 outside the mold frame 22.
[0006]
Further, a lens sheet 32 and a liquid crystal panel 29 are arranged in order from the bottom on the front side of the light guide plate 21 (upper side in FIG. 10), and a portion near the front peripheral edge of the liquid crystal panel 29 is covered with a front frame 31. Yes. Further, the liquid crystal panel 29 is electrically connected to the control board 30 via tape wiring or the like.
[0007]
[Problems to be solved by the invention]
Conventionally, in a planar light source device used as a backlight for a liquid crystal display device, the luminance uniformity of the entire light emitting surface is required. In order to make the entire light emitting surface emit light uniformly, it is desirable that the side of the light guide plate 21 has a simple structure as viewed from the light emitting surface side. However, if the structure is complicated, such as providing a convex protrusion 27 for positioning as in the conventional light guide plate 21, the luminance uniformity in the vicinity thereof is impaired, leading to a reduction in image quality.
[0008]
Further, a complicated structure such as a convex shape becomes a factor that makes it difficult to mold the light guide plate 21.
[0009]
Further, when the light guide plate 21 is assembled to the mold frame 22, it is necessary to fit the pair of convex protrusions 27 into the recesses 28, which requires skill and labor.
[0010]
In addition, with the progress of the information society, liquid crystal display devices such as notebook-type personal computers and word processors are also becoming lighter and thinner, and portable devices are desired in the market. Therefore, there is a tendency that the frame not related to the display, that is, the frame of the mold frame 22 is narrowed and the density of parts is increased. The width of the convex-shaped protrusion 27 for the purpose of positioning the light guide plate 21 also tends to be reduced due to the influence of the narrow frame. When the light guide plate 21 is positioned with the projections 27 having a small ear shape as in the prior art, when the liquid crystal display device is carried and an impact is applied due to a drop or the like, the base of the projections 27 having a convex shape is formed. Stress concentration is applied to the portion, and the portion near the base of the light guide plate 21 is cracked, which may affect the display.
[0011]
The present invention has been made to solve such a problem. A planar light source device having uniform brightness, easy manufacture, easy assembly of a light guide plate, and excellent shock resistance. provide.
[0012]
[Means for Solving the Problems]
A planar light source device according to claim 1 of the present invention includes a light guide plate made of a translucent material, a rod-like light source disposed in the vicinity of a light incident surface formed on a peripheral end surface of the light guide plate, A planar light source device comprising a frame that holds a pair of side end surfaces extending on both sides of the light incident surface among the peripheral end surfaces of the light guide plate,
The planar shape of the light guide plate is a shape in which the entire pair of side end surfaces are inclined with respect to the light incident surface , and the pair of side end surfaces further toward the light incident surface. Presents a shape with an inclined part so that the space between the side end faces is narrow ,
The space portion of the frame has a shape substantially complementary to the planar shape of the light guide plate.
[0013]
It is preferable that the planar shape of the light guide plate has a trapezoidal shape with a terminal surface facing the light incident surface as a base.
[0017]
It is preferable that the planar shape of the light guide plate is a hexagon that is bent outward at an approximately middle position between the pair of side end surfaces.
[0018]
It is preferable that the planar shape of the light guide plate is a hexagon that is bent inward at a substantially middle position between the pair of side end surfaces.
[0019]
A planar light source device according to claim 5 of the present invention includes a light guide plate made of a light-transmitting material, a rod-shaped light source disposed in the vicinity of a light incident surface formed on a peripheral end surface of the light guide plate, A planar light source device comprising a frame that holds a pair of side end surfaces extending on both sides of the light incident surface among the peripheral end surfaces of the light guide plate,
The planar shape of the light guide plate is a shape in which the entire pair of side end surfaces are curved with respect to the light incident surface , and the pair of side end surfaces further toward the light incident surface. Presents a shape with a curved part so that the space between the side end faces is narrow ,
The space portion of the frame has a shape substantially complementary to the planar shape of the light guide plate.
[0020]
The planar shape of the light guide plate preferably has a shape in which the pair of side end surfaces are curved inward.
[0021]
It is preferable that the planar shape of the light guide plate has a shape in which the pair of side end surfaces are curved outward.
[0022]
A planar light source device according to an eighth aspect of the present invention includes a light guide plate made of a light-transmitting material, a rod-shaped light source disposed in the vicinity of a light incident surface formed on a peripheral end surface of the light guide plate, A planar light source device comprising a frame that holds a pair of side end surfaces extending on both sides of the light incident surface among the peripheral end surfaces of the light guide plate,
The planar shape of the light guide plate is such that the entire pair of side end surfaces has a substantially wavy shape,
The space portion of the frame has a shape substantially complementary to the planar shape of the light guide plate.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Next, the planar light source device of the present invention will be described in more detail with reference to the drawings. FIG. 1 is an exploded perspective view of a liquid crystal display device including a planar light source device having a trapezoidal light guide plate showing an embodiment of the planar light source device of the present invention, and FIG. 2 is a planar light source device of FIG. plan view of FIG. 3 is a plan explanatory view of a surface light source device having an inverted trapezoidal shape of the light guide plate showing the surface light source equipment according to embodiment, FIG. 4 shows a planar light source equipment according to embodiment plan view of a surface light source device having a light guide plate of the parallelogram-shaped, FIG. 5 is a surface shape having a light guide plate of hexagonal shape side end face showing a surface light source equipment according to embodiment is bent outwardly FIG. 6 is an explanatory plan view of a light source device, and FIG. 6 is an explanatory plan view of the planar light source device having a hexagonal light guide plate whose side end surface is bent inward, showing still another embodiment of the planar light source device of the present invention. FIG. 7 shows still another embodiment of the planar light source device of the present invention, in which the side end surface is curved inward. FIG. 8 is a plan view of a planar light source device having a light guide plate, and FIG. 8 shows a planar light source having a light guide plate whose side end surface is curved outward, showing still another embodiment of the planar light source device of the present invention. FIG. 9 is an explanatory plan view of the apparatus, and FIG. 9 is an explanatory plan view of the planar light source apparatus having a light guide plate having a substantially corrugated shape on the entire side end surface showing still another embodiment of the planar light source apparatus of the present invention.
[0024]
The planar light source device of the present embodiment shown in FIGS. 1 and 2 is provided with a lamp 3 which is a rod-shaped light source in the vicinity of the light incident surface 1a on the peripheral end surface of the light guide plate 1 made of a translucent material. The light guide plate 1 and the lamp 3 are housed and held in a mold frame 2. The planar shape of the light guide plate 1 is such that the entire pair of side end surfaces 1b is inclined with respect to the light incident surface 1a, while the space portion of the frame 2 is substantially the planar shape of the light guide plate 1. It has a complementary shape.
[0025]
As shown in FIG. 2, the light guide plate 1 has a relatively simple shape without the conventional positioning protrusions 27 (see FIGS. 10 to 11), and therefore emits light from the front surface of the light guide plate 1 with uniform brightness. Can do. In addition, since the light guide plate 1 has a simple shape, the light guide plate 1 can be easily molded, and the light guide plate 1 can be easily assembled to the mold frame 2.
[0026]
Further, as shown in FIG. 2, when the liquid crystal display device is placed with the lamp 3 facing upward, the light guide plate 1 is positioned by the side end surface 1b and the end surface 1c, and the light guide plate 1 in the vertical direction is located. The movement of can be suppressed.
[0027]
In addition, since the entire side end surface 1b is inclined and linearly extended, the load (static load or impact load) applied to the light guide plate 1 is dispersed by contacting the mold frame 2 with the entire side end surface 1b. Can receive. Therefore, the light guide plate 1 is less likely to be damaged because there is no portion where stress is concentrated.
[0028]
Furthermore, since the planar shape of the light guide plate 1 shown in FIG. 2 has a trapezoidal shape with the end surface 1c facing the light incident surface 1a as a base, even if the light guide plate 1 tries to move toward the lamp 3, Since the end surface 1c is longer than the light incident surface 1a, the light guide plate 1 does not slide out from the lamp 3 side.
[0029]
In the case of the trapezoidal light guide plate 1 of FIG. 2, the angle θ 1 of the side end surface 1b with respect to the light incident surface 1a is set in a range of about 90 ° <θ 1 ≦ 100 ° (preferably 93.8 °). For example, even in a normal module (when the aspect ratio is vertical: horizontal = 3: 4), the ratio of the sides of the light incident surface 1a and the end surface 1c does not exceed 1: 1.25, so that a narrow frame can be achieved. .
[0030]
In the planar light source device of FIGS. 1 and 2, a lamp 3 such as a cold cathode tube or a hot cathode tube is used as a rod-like light source, and the lamp 3 is made of a material such as an acrylic resin having a high transmittance. A diffusion sheet made of a white synthetic resin plate that is disposed in the vicinity of the light guide plate 1 and has a light scattering effect for the purpose of making the light from the lamp 3 uniform is provided on the opposite side of the diffusion sheet. In this case, a specular reflection or a white reflection plate is used, and the reflection sheet reflects light toward the rear side out of the light entering the light guide plate 1 from the lamp 3 to improve the light use efficiency. ing.
[0031]
1 and 2, the lamp 3 is fixed to one side of the mold frame 2 by a lamp rubber 4, and the lamp reflector 13 is opened on the outer periphery of the lamp 3 only in a direction facing the light guide plate 1. The lamp cable 5 extending from both ends of the lamp 3 is connected to the lamp connector 6 outside the mold frame 2.
[0032]
Further, a lens sheet 12 and a liquid crystal panel 9 are arranged in order from the bottom on the front side of the light guide plate 1 (upper side in FIG. 1), and a portion near the front periphery of the liquid crystal panel 9 is covered with a front frame 11. Yes. Further, the liquid crystal panel 9 is electrically connected to the control board 10 via tape wiring or the like.
[0033]
In the above-described embodiment, the trapezoidal shape with the end face 1c shown in FIG. 2 as the base is described as an example of the shape in which the entire side end face 1b is inclined. However, the present invention is not limited to this. Instead, the planar shape of the light guide plate 1 as shown in FIG. 3 may be a trapezoidal shape with the light incident surface 1a as a base.
[0034]
Since the light guide plate 1 in FIG. 3 has a structure that becomes gradually thinner from the light incident surface 1a toward the end surface 1c as in FIG. 1, the angle at both ends of the thinnest end surface 1c is larger than 90 °, so that the light guide plate 1 1 has the advantage of less damage.
[0035]
Further, as shown in FIG. 4, even if the planar shape of the light guide plate 1 has a parallelogram shape, the same effect as that of the above embodiment can be obtained. In the case of FIG. 4, the angle θ 3 of the side end surface 1b with respect to the light incident surface 1a is approximately 90 ° <θ 3 ≦ 100 ° (preferably 93.8 °) or 80 ° ≦ θ 3 <90 ° (preferably 86.2). If it is in any range of about 0 °, narrowing of the frame can be achieved as in the case of FIG.
[0036]
In the case of FIGS. 3 to 4, since the receiving portion 7 for receiving the light incident surface 1 a of the light guide plate 1 is provided between the light guide plate 1 and the lamp 3 inside the light guide plate 1, 1 can be suitably prevented from moving to the lamp 3.
[0037]
Further, as shown in FIG. 5, even when the planar shape of the light guide plate 1 is a hexagonal shape bent outward at a substantially middle position between the pair of side end faces 1b, the same effect as in the above embodiment is obtained. Can play. In the case of FIG. 5, if the angle θ 4 of the side end surface 1b with respect to the light incident surface 1a is in the range of about 90 ° <θ 4 ≦ 108 ° (preferably 97.6 °), the narrow frame as in the case of FIG. Can be achieved.
[0038]
Further, as shown in FIG. 6, even if the planar shape of the light guide plate 1 is a hexagonal shape bent inward at a substantially intermediate position between the pair of side end faces 1b, the same effect as in the above embodiment is obtained. Can play. In the case of FIG. 6, if the angle θ 5 of the side end surface 1b with respect to the light incident surface 1a is in the range of about 72 ° <θ 5 ≦ 90 ° (preferably 86.2 °), the narrow frame as in FIG. Can be achieved.
[0039]
Further, as an embodiment of the invention according to claim 5 of the present invention, as shown in FIGS. 7 to 8, as shown in FIGS. A lamp 3 as a light source is disposed, the light guide plate 1 and the lamp 3 are housed and held in a mold frame 2, and the planar shape of the light guide plate 1 is such that the entire pair of side end surfaces 1b are in relation to the light incident surface 1a. The shape may be curved inward or outward, and the space of the mold frame 2 may have a shape that is substantially complementary to the planar shape of the light guide plate 1. Also in this case, as in the above-described embodiment, it is possible to achieve improvement in luminance uniformity, ease of molding, ease of assembly, and impact resistance.
[0040]
As shown in FIG. 7, when the entire pair of side end surfaces 1 b have a shape curved inward with respect to the light incident surface 1 a, the ratio of the width of the light guide plate 1 is X 11 : X 12 = 1.1. If the ratio is less than 1, narrowing of the frame can be achieved.
[0041]
On the other hand, as shown in FIG. 8, when the whole of the pair of side end surfaces 1b has a shape curved outward with respect to the light incident surface 1a, the width ratio between the end portion and the intermediate portion of the light guide plate 1 is X. If the ratio is less than 21 : X 22 = 1: 1.1, narrowing of the frame can be achieved.
[0042]
Furthermore, as an embodiment of the invention according to claim 8 of the present invention, as shown in FIG. 9, a rod-shaped light source is used in the vicinity of the light incident surface 1a on the peripheral end surface of the light guide plate 1 made of a light transmitting material. A certain lamp 3 is disposed, and the light guide plate 1 and the lamp 3 are housed and held in the mold frame 2, and the planar shape of the light guide plate 1 and the entire pair of side end surfaces 1 b are substantially corrugated. Even in the case where the space portion has a shape substantially complementary to the planar shape of the light guide plate 1, the luminance uniformity, ease of assembly, ease of assembly, and impact resistance are the same as in the above embodiment. An improvement can be achieved. In the case of FIG. 9, narrowing of the frame can be achieved if the width ratio between the end portion and the intermediate portion of the light guide plate 1 is smaller than X 31 : X 32 = 1: 1.1.
[0043]
9 has different widths such as X 31 and X 32 depending on the location, but when the width of the undulations of the pair of side end faces 1b is made constant to make the width constant. However, the same effect as in FIG. 9 can be obtained.
[0044]
In the case of FIGS. 2 to 9 described above, the lamp 3 is disposed on the upper side, but the present invention is not limited to this, and can be applied to any of the other three sides. Moreover, it is applicable also to the thing of the multiple lamp system which has the lamp | ramp 3 in two opposing sides (both the light-incidence surface 1a and the termination surface 1c).
[0045]
【The invention's effect】
According to the present invention, since the projection is omitted from the side end surface of the light guide plate and the light guide plate is supported by the entire side end surface, the luminance is uniform, the manufacture is easy, and the light guide plate is easily assembled. In addition, it has excellent impact resistance.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a liquid crystal display device including a planar light source device having a trapezoidal light guide plate showing an embodiment of the planar light source device of the present invention.
2 is an explanatory plan view of the planar light source device of FIG. 1. FIG.
3 is a plan view of a surface light source device having a light guide plate of an inverted trapezoidal shape shown a surface light source equipment according to Embodiment.
4 is a plan view of a surface light source device having a light guide plate of a parallelogram shape showing a surface light source equipment according to Embodiment.
5 is a plan view of a planar light source device side end face showing a surface light source equipment according to Embodiment has a light guide plate of hexagonal shape which is bent outwardly.
FIG. 6 is an explanatory plan view of a planar light source device having a hexagonal light guide plate whose side end surface is bent inward, showing still another embodiment of the planar light source device of the present invention.
FIG. 7 is an explanatory plan view of a planar light source device having a light guide plate with a side end surface curved inward, showing still another embodiment of the planar light source device of the present invention.
FIG. 8 is an explanatory plan view of a planar light source device having a light guide plate whose side end surface is curved outward, showing still another embodiment of the planar light source device of the present invention.
FIG. 9 is an explanatory plan view of a planar light source device having a light guide plate having a substantially corrugated shape on the entire side end surface showing still another embodiment of the planar light source device of the present invention.
FIG. 10 is an exploded perspective view of a liquid crystal display device including a conventional planar light source device.
11 is a plan view of the planar light source device of FIG.
[Name of code]
1 Light guide plate 2 Mold frame 3 Lamp

Claims (8)

透光性材料からなる導光板と、該導光板の周端面に形成された入光面に近接して配設された棒状光源と、前記導光板の周端面のうち前記入光面の両側にのびる一対の側端面を保持するフレームとからなる面状光源装置であって、
前記導光板の平面形状が、前記一対の側端面の全体が前記入光面に対して傾斜した形状であって、さらに前記一対の側端面は、前記入光面の方向に向って該一対の側端面間が狭くなるように傾斜した部分をもつ形状を呈し、
前記フレームの空間部が、前記導光板の平面形状に実質的に相補的な形状を呈してなる面状光源装置。A light guide plate made of a translucent material, a rod-like light source disposed in the vicinity of the light incident surface formed on the peripheral end surface of the light guide plate, and on both sides of the light incident surface of the peripheral end surface of the light guide plate A planar light source device comprising a frame that holds a pair of extending side end surfaces,
The planar shape of the light guide plate is a shape in which the entire pair of side end surfaces are inclined with respect to the light incident surface , and the pair of side end surfaces further toward the light incident surface. Presents a shape with an inclined part so that the space between the side end faces is narrow ,
A planar light source device in which a space portion of the frame has a shape substantially complementary to a planar shape of the light guide plate. 前記導光板の平面形状が、前記入光面に対向する終端面を底辺とする台形を呈してなる請求項１記載の面状光源装置。  The planar light source device according to claim 1, wherein the planar shape of the light guide plate has a trapezoidal shape with a terminal surface facing the light incident surface as a base. 前記導光板の平面形状が、前記一対の側端面のほぼ中間位置で外方へ屈曲した六角形を呈してなる請求項１記載の面状光源装置。  The planar light source device according to claim 1, wherein the planar shape of the light guide plate is a hexagon that is bent outward at a substantially intermediate position between the pair of side end surfaces. 前記導光板の平面形状が、前記一対の側端面のほぼ中間位置で内方へ屈曲した六角形を呈してなる請求項１記載の面状光源装置。  The planar light source device according to claim 1, wherein the planar shape of the light guide plate is a hexagon that is bent inward at a substantially intermediate position between the pair of side end surfaces. 透光性材料からなる導光板と、該導光板の周端面に形成された入光面に近接して配設された棒状光源と、前記導光板の周端面のうち前記入光面の両側にのびる一対の側端面を保持するフレームとからなる面状光源装置であって、
前記導光板の平面形状が、前記一対の側端面の全体が前記入光面に対して湾曲した形状であって、さらに前記一対の側端面は、前記入光面の方向に向って該一対の側端面間が狭くなるように湾曲した部分をもつ形状を呈し、
前記フレームの空間部が、前記導光板の平面形状に実質的に相補的な形状を呈してなる面状光源装置。A light guide plate made of a translucent material, a rod-like light source disposed in the vicinity of the light incident surface formed on the peripheral end surface of the light guide plate, and on both sides of the light incident surface of the peripheral end surface of the light guide plate A planar light source device comprising a frame that holds a pair of extending side end surfaces,
The planar shape of the light guide plate is a shape in which the entire pair of side end surfaces are curved with respect to the light incident surface , and the pair of side end surfaces further toward the light incident surface. Presents a shape with a curved part so that the space between the side end faces is narrow ,
A planar light source device in which a space portion of the frame has a shape substantially complementary to a planar shape of the light guide plate. 前記導光板の平面形状が、前記一対の側端面が内方へ湾曲した形状を呈してなる請求項５記載の面状光源装置。The planar light source device according to claim 5 , wherein the planar shape of the light guide plate has a shape in which the pair of side end surfaces are curved inward. 前記導光板の平面形状が、前記一対の側端面が外方へ湾曲した形状を呈してなる請求項５記載の面状光源装置。The planar light source device according to claim 5 , wherein the planar shape of the light guide plate has a shape in which the pair of side end surfaces are curved outward. 透光性材料からなる導光板と、該導光板の周端面に形成された入光面に近接して配設された棒状光源と、前記導光板の周端面のうち前記入光面の両側にのびる一対の側端面を保持するフレームとからなる面状光源装置であって、
前記導光板の平面形状が、前記一対の側端面の全体が略波形形状を呈し、
前記フレームの空間部が、前記導光板の平面形状に実質的に相補的な形状を呈してなる面状光源装置。A light guide plate made of a translucent material, a rod-like light source disposed in the vicinity of the light incident surface formed on the peripheral end surface of the light guide plate, and on both sides of the light incident surface of the peripheral end surface of the light guide plate A planar light source device comprising a frame that holds a pair of extending side end surfaces,
The planar shape of the light guide plate is such that the whole of the pair of side end faces has a substantially wavy shape,
A planar light source device in which a space portion of the frame has a shape substantially complementary to a planar shape of the light guide plate.
JP21997999A 1999-08-03 1999-08-03 Surface light source device Expired - Fee Related JP4256540B2 (en)

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KR100840715B1 (en) * 2002-05-28 2008-06-23 삼성전자주식회사 Back light assembly and liquid crystal display having the same
KR100701075B1 (en) 2003-07-09 2007-03-29 비오이 하이디스 테크놀로지 주식회사 Light guide plate fixed structure of back light unit for liquid crystal display
JP4802747B2 (en) * 2006-02-09 2011-10-26 日亜化学工業株式会社 Display device
JP4876647B2 (en) * 2006-03-14 2012-02-15 ソニー株式会社 Planar light source device and liquid crystal display device assembly
JP4706858B2 (en) * 2006-07-10 2011-06-22 ミネベア株式会社 Surface lighting device
JP5294642B2 (en) * 2008-01-25 2013-09-18 シチズン電子株式会社 Liquid crystal display device and injection mold for forming a thin light guide plate used in the liquid crystal display device
JP2012230243A (en) * 2011-04-26 2012-11-22 Funai Electric Co Ltd Liquid crystal display module and liquid crystal display apparatus
US9678267B2 (en) * 2012-05-18 2017-06-13 Reald Spark, Llc Wide angle imaging directional backlights
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