JP2010033058A - Liquid crystal display device and illumination device - Google Patents

Liquid crystal display device and illumination device Download PDF

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JP2010033058A
JP2010033058A JP2009183984A JP2009183984A JP2010033058A JP 2010033058 A JP2010033058 A JP 2010033058A JP 2009183984 A JP2009183984 A JP 2009183984A JP 2009183984 A JP2009183984 A JP 2009183984A JP 2010033058 A JP2010033058 A JP 2010033058A
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liquid crystal
distance
linear light
crystal panel
light source
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Tetsutoyo Konno
哲豊 紺野
Yoshifumi Sekiguchi
好文 關口
Makoto Tsumura
誠 津村
Ikuo Hiyama
郁夫 桧山
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Hitachi Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of displaying a satisfactory image in which luminance unevenness is suppressed even when an illumination device is made thin. <P>SOLUTION: In the liquid crystal display, a distance D between a reflection sheet 5 and a diffusion sheet 11 is specified to be 7 to 13 mm, a distance p (mm) between adjacent fluorescent tubes 2 and the distance D (mm) satisfy relational expression of p≤1.34×D+9, a distance e (mm) from a boundary between the upper end surface 5a of the reflection sheet 5 and an inclined surface 5b to the nearest fluorescent tube 2 and the distance D (mm) satisfy relational expression of 13.7e≤1.6×D+4. The diffusion sheet 11 is a diffusion sheet with a pattern having a rugged shape on a liquid crystal panel 3 side surface, an optical sheet 12 disposed on the front of the diffusion sheet with the pattern includes at least two diffusion sheets and one light condensing film. The reflection sheet 5 has the inclined surfaces 5b at end parts thereof and a distance between the reflection sheet 5 and center axes of the fluorescent tubes 2 is 2.8 mm or less. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、液晶表示装置の小型化及び液晶表示装置のバックライトとして用いる照明装置の薄型化に関する。   The present invention relates to miniaturization of a liquid crystal display device and thinning of an illumination device used as a backlight of the liquid crystal display device.

従来例の液晶表示装置として、特許文献1に記載の通り、画像を表示する液晶パネルと、この液晶パネルの背面に配置され、液晶パネルに白色光を出射する照明装置とを有する液晶表示装置が開示されている。そして、この液晶表示装置の照明装置は、複数の蛍光管と、この蛍光管の背面に配置され、蛍光管からの白色光を拡散して反射する反射部材と、蛍光管の正面に配置され、蛍光管からの白色光を拡散して透過する拡散板を有する。   As a conventional liquid crystal display device, as described in Patent Document 1, there is a liquid crystal display device having a liquid crystal panel that displays an image and an illumination device that is disposed on the back surface of the liquid crystal panel and emits white light to the liquid crystal panel. It is disclosed. And the illuminating device of this liquid crystal display device is arranged on the front surface of the fluorescent tube, a plurality of fluorescent tubes, a reflective member that diffuses and reflects white light from the fluorescent tube, It has a diffusion plate that diffuses and transmits white light from the fluorescent tube.

特開2005−347062号公報JP-A-2005-347062

前述の従来の液晶表示装置では、小型化のために照明装置を薄型化した際、液晶パネル上において、蛍光管の真上付近は明るくなるものの、隣接し合う蛍光管と蛍光管との中間の真上付近は暗くなることにより、図10の通り、液晶パネルの輝度分布が一様にならずに、液晶パネル上の画面縦方向位置に応じて、即ち、蛍光管の真上付近の位置であるか否かに応じて輝度が変化するため、蛍光管の発光部が輝度ムラとして見えるという不具合が発生する。   In the above-described conventional liquid crystal display device, when the illumination device is thinned for miniaturization, the area immediately above the fluorescent tube becomes bright on the liquid crystal panel, but it is intermediate between the adjacent fluorescent tubes. As the area near the top becomes dark, the luminance distribution of the liquid crystal panel is not uniform as shown in FIG. 10, but according to the vertical position of the screen on the liquid crystal panel, that is, at a position near the top of the fluorescent tube. Since the luminance changes depending on whether or not there is, there is a problem that the light emitting part of the fluorescent tube appears as luminance unevenness.

更に、図10の通り、液晶パネルの中央付近に比べて、画面縦方向での両端部近傍の輝度が低下する。即ち、液晶パネルの中央付近に比べて、画面縦方向での両端部近傍では暗くなるという不具合が発生する。なお、図10は、従来例の液晶表示装置の液晶パネルの画面縦方向での輝度分布を示す図である。   Furthermore, as shown in FIG. 10, the brightness in the vicinity of both ends in the vertical direction of the screen is lower than that in the vicinity of the center of the liquid crystal panel. That is, there is a problem that it becomes darker in the vicinity of both ends in the vertical direction of the screen than in the vicinity of the center of the liquid crystal panel. FIG. 10 is a diagram showing a luminance distribution in the vertical direction of the screen of the liquid crystal panel of the conventional liquid crystal display device.

そこで本発明では、照明装置を薄型化しても、輝度ムラを抑制した良好な画像を表示することができる液晶表示装置を提供することを目的とする。   Therefore, an object of the present invention is to provide a liquid crystal display device capable of displaying a good image with reduced luminance unevenness even if the lighting device is thinned.

そこで本発明では、画像を表示する液晶パネルと、該液晶パネルの背面に配置され、前記液晶パネルに光を出射する照明装置とを有し、該照明装置は、前記液晶パネルの画面横方向に略平行に配置された複数の線状光源(蛍光管)と、該線状光源の背面に配置され、前記線状光源からの光を拡散して反射する反射部材(反射シート)と、前記線状光源の正面に配置され、前記線状光源からの光を拡散して透過する拡散透過部材(透過板)とを有する液晶表示装置において、前記反射部材と前記拡散透過部材との距離Dは、7〜13mmであり、各前記線状光源間の距離p(mm)と、前記反射部材と前記拡散透過部材との距離D(mm)とは、p≦1.34×D+9の関係式を満たすと共に、前記液晶パネルの画面縦方向での前記反射部材の端部に最も近い前記線状光源と前記反射部材の端部との距離e(mm)と、前記反射部材と前記拡散透過部材との前記距離D(mm)とは、13.7e≦1.6×D+4の関係式を満たし、前記拡散透過部材は、前記液晶パネル側の面が凹凸形状であるパターン付き拡散透過部材であり、前記パターン付き拡散透過部材の正面に配置される光学シートは、少なくとも2枚の拡散シートと1枚の集光フィルムを含み、前記反射部材は端部において傾斜面を有し、前記反射部材と前記線状光源の中心軸との距離は2.8mm以下である。   Therefore, the present invention includes a liquid crystal panel that displays an image, and an illumination device that is disposed on the back surface of the liquid crystal panel and emits light to the liquid crystal panel, and the illumination device is arranged in a horizontal direction of the screen of the liquid crystal panel. A plurality of linear light sources (fluorescent tubes) disposed substantially in parallel, a reflective member (reflective sheet) disposed on the back surface of the linear light source and diffusing and reflecting light from the linear light source, and the line In the liquid crystal display device that is disposed in front of the light source and has a diffusion transmission member (transmission plate) that diffuses and transmits light from the linear light source, the distance D between the reflection member and the diffusion transmission member is: 7 to 13 mm, and the distance p (mm) between the linear light sources and the distance D (mm) between the reflection member and the diffuse transmission member satisfy the relational expression of p ≦ 1.34 × D + 9. And at the end of the reflective member in the vertical direction of the screen of the liquid crystal panel. The distance e (mm) between the linear light source and the end of the reflection member and the distance D (mm) between the reflection member and the diffuse transmission member are 13.7e ≦ 1.6 × D + 4. The diffuse transmission member satisfying the relational expression is a diffused transmission member with a pattern in which the surface on the liquid crystal panel side has an uneven shape, and at least two optical sheets arranged in front of the diffuse transmission member with the pattern The reflecting member includes a diffusion sheet and a single condensing film, the reflecting member has an inclined surface at an end, and the distance between the reflecting member and the central axis of the linear light source is 2.8 mm or less.

本発明によれば、照明装置を薄型化しても、輝度ムラを抑制した良好な画像を表示する液晶表示装置を提供することができる。   ADVANTAGE OF THE INVENTION According to this invention, even if it makes a lighting apparatus thin, the liquid crystal display device which displays the favorable image which suppressed the brightness nonuniformity can be provided.

本発明の一実施形態である液晶表示装置の構造を示す分解図。1 is an exploded view showing a structure of a liquid crystal display device according to an embodiment of the present invention. 本発明の一実施形態である液晶表示装置の構造を示す正面図(全断面図)。1 is a front view (entire cross-sectional view) illustrating a structure of a liquid crystal display device according to an embodiment of the present invention. 本発明の一実施形態である液晶表示装置の構造を示す側面図(A−A断面図)。The side view (AA sectional drawing) which shows the structure of the liquid crystal display device which is one Embodiment of this invention. 本発明の一実施形態である液晶表示装置における蛍光管の配置を示す図。The figure which shows arrangement | positioning of the fluorescent tube in the liquid crystal display device which is one Embodiment of this invention. パターン付き拡散板の外観を示す斜視図。The perspective view which shows the external appearance of the diffusion plate with a pattern. 本発明の一実施形態である液晶表示装置における液晶パネルの画面縦方向位置と輝度との関係を示す図。The figure which shows the relationship between the screen vertical direction position of a liquid crystal panel and the brightness | luminance in the liquid crystal display device which is one Embodiment of this invention. 輝度ムラを抑制することができる蛍光管ピッチpを導出する実験における実験条件を示す図。The figure which shows the experimental condition in the experiment which derives | leads-out the fluorescent tube pitch p which can suppress brightness nonuniformity. 輝度ムラを抑制することができる蛍光管ピッチp及びバックライト上下端から端部側蛍光管までの距離eを導出する実験における実験結果を示す図。The figure which shows the experimental result in the experiment which derives | leads-out the distance e from the fluorescent tube pitch p which can suppress brightness | luminance nonuniformity, and the backlight upper-lower end to an edge part side fluorescent tube. 輝度ムラを抑制することができるバックライト上下端から端部側蛍光管までの距離eを導出する実験における実験条件を示す図。The figure which shows the experimental condition in the experiment which derives | leads-out the distance e from the backlight upper and lower ends to the edge part side fluorescent tube which can suppress brightness nonuniformity. 従来例の液晶表示装置における液晶パネルの画面縦方向位置と輝度との関係を示す図。The figure which shows the relationship between the screen vertical direction position of a liquid crystal panel and a brightness | luminance in the liquid crystal display device of a prior art example.

以下、本発明の一実施形態である液晶表示装置について、説明する。   Hereinafter, a liquid crystal display device according to an embodiment of the present invention will be described.

<1.本実施形態の液晶表示装置の構造>
まず、本実施形態の液晶表示装置の構造について、図1〜図4を用いて説明する。図1は、本実施形態の液晶表示装置の構造を示す分解図、図2は、本実施形態の液晶表示装置の構造を示す正面図(全断面図)、図3は、本実施形態の液晶表示装置の構造を示す側面図(A−A断面図)、図4は、本実施形態の液晶表示装置における蛍光管の配置を示す図である。
<1. Structure of liquid crystal display device of this embodiment>
First, the structure of the liquid crystal display device of this embodiment will be described with reference to FIGS. FIG. 1 is an exploded view showing the structure of the liquid crystal display device of the present embodiment, FIG. 2 is a front view (full sectional view) showing the structure of the liquid crystal display device of the present embodiment, and FIG. FIG. 4 is a side view (AA sectional view) showing the structure of the display device, and FIG. 4 is a view showing the arrangement of the fluorescent tubes in the liquid crystal display device of this embodiment.

本実施形態の液晶表示装置1は、線状光源であり、均一な白色光を照射する9本の蛍光管2と、画像が表示される液晶パネル3を有し、各蛍光管2からの白色光が、バックライトとして、液晶パネル3に入射される。なお、本実施形態の液晶表示装置1では、蛍光管の本数は、9本であるが、複数であるのならば、8本以下でも、10本以上でも良い。蛍光管2は、図1,図2の通り、両端にある電極2aが下サイドモールド7に固定された電極ホルダ8に保持されることにより、反射シート5から所定の高さの位置に固定される。なお、下サイドモールド7は、下フレーム4に貼り付けられた反射シート5に固定される。更に、蛍光管2は、図3,図4の通り、同一ピッチで配置される(ピッチは、図3,図4においては、符号pで示す)。即ち、隣接し合う蛍光管2同士の距離が同じとなるように蛍光管2は配置される。また、蛍光管2を駆動するインバータ15は、即ち、蛍光管から白色光を発光させるための装置であるインバータ15は、図1〜図3の通り、下フレーム4の下部に固定される。   The liquid crystal display device 1 of the present embodiment is a linear light source, and includes nine fluorescent tubes 2 that emit uniform white light and a liquid crystal panel 3 on which an image is displayed. Light enters the liquid crystal panel 3 as a backlight. In the liquid crystal display device 1 according to the present embodiment, the number of fluorescent tubes is nine. However, if there are a plurality of fluorescent tubes, the number may be eight or less or ten or more. As shown in FIGS. 1 and 2, the fluorescent tube 2 is fixed at a predetermined height from the reflection sheet 5 by holding the electrodes 2a at both ends by the electrode holder 8 fixed to the lower side mold 7. The The lower side mold 7 is fixed to the reflection sheet 5 attached to the lower frame 4. Further, the fluorescent tubes 2 are arranged at the same pitch as shown in FIGS. 3 and 4 (the pitch is indicated by a symbol p in FIGS. 3 and 4). That is, the fluorescent tubes 2 are arranged so that the distances between the adjacent fluorescent tubes 2 are the same. The inverter 15 that drives the fluorescent tube 2, that is, the inverter 15 that is a device for emitting white light from the fluorescent tube, is fixed to the lower portion of the lower frame 4 as shown in FIGS. 1 to 3.

そして、拡散板11は、図1,図2の通り、下サイドモールド7を覆いかぶすように設けられた上サイドモールド9により、反射シート5から所定の高さの位置に固定され、この拡散板11には、4枚の光学シート12が貼り付けられる。なお、4枚の光学シート12は、本実施形態の液晶表示装置1では、拡散板11側から拡散シート,集光フィルム,拡散シート,拡散シートの順番で積み重ねられた構成となっているが、拡散板11側から拡散シート,集光フィルム,拡散シート,偏光反射フィルムの順番で積み重ねられた構成等、他の構成であっても良い。また、光学シート12は、3枚以下でも、5枚以上でも良い。更に、本実施形態の液晶表示装置1では、拡散板11の液晶パネル3側の面は平面であるが、図5の通り、液晶パネル3側の面が凹凸形状であるパターン付き拡散板(パターン付き拡散透過部材)11′であっても良い。なお、図5は、パターン付き拡散板の外形を示す斜視図である。   The diffusion plate 11 is fixed at a predetermined height from the reflection sheet 5 by an upper side mold 9 provided so as to cover the lower side mold 7 as shown in FIGS. Four optical sheets 12 are attached to the plate 11. In addition, in the liquid crystal display device 1 of the present embodiment, the four optical sheets 12 have a configuration in which the diffusion sheet, the light collecting film, the diffusion sheet, and the diffusion sheet are stacked in this order from the diffusion plate 11 side. Other configurations such as a configuration in which a diffusion sheet, a light collecting film, a diffusion sheet, and a polarizing reflection film are stacked in this order from the diffusion plate 11 side may be used. Further, the optical sheet 12 may be 3 sheets or less or 5 sheets or more. Furthermore, in the liquid crystal display device 1 of the present embodiment, the surface of the diffusion plate 11 on the liquid crystal panel 3 side is a flat surface, but as shown in FIG. Diffusion / transmission member 11 'may be used. FIG. 5 is a perspective view showing the outer shape of the diffuser with pattern.

液晶パネル3は、中間フレーム13の溝13aに嵌め込まれた後、中間フレーム13に接着剤等により固定される。そして、液晶パネル3が固定された中間フレーム13に、上フレーム14が固定される。   The liquid crystal panel 3 is fitted into the groove 13a of the intermediate frame 13, and then fixed to the intermediate frame 13 with an adhesive or the like. Then, the upper frame 14 is fixed to the intermediate frame 13 to which the liquid crystal panel 3 is fixed.

<2.本実施形態の液晶表示装置の動作>
次に、本実施形態の液晶表示装置1の動作について、説明する。
反射シート5は蛍光管2からの反射光を効率良く上方へ拡散反射すること、更に、拡散板11は蛍光管2からの白色光を拡散しながら透過することにより、蛍光管2から発光された白色光は、反射シート5と拡散板11の間を複数回の拡散と反射を繰り返しながら出射した後、拡散板11の上面に配置された4枚の光学シート12により、拡散性と指向性とが制御される。
<2. Operation of Liquid Crystal Display Device of Present Embodiment>
Next, the operation of the liquid crystal display device 1 of the present embodiment will be described.
The reflective sheet 5 efficiently diffuses and reflects the reflected light from the fluorescent tube 2 upward, and the diffuser plate 11 emits light from the fluorescent tube 2 by diffusing and transmitting white light from the fluorescent tube 2. White light is emitted between the reflection sheet 5 and the diffusion plate 11 while being repeatedly diffused and reflected a plurality of times, and then is diffused and directed by the four optical sheets 12 disposed on the upper surface of the diffusion plate 11. Is controlled.

<3.本実施形態の液晶表示装置における輝度ムラの抑制>
次に、本実施形態の液晶表示装置1における輝度ムラの抑制について、説明する。
本実施形態の液晶表示装置1では、蛍光管2,反射シート5,拡散板11,4枚の光学シート12等から成る照明装置の薄型化により、反射シート5から拡散板11までの距離Dが小さくなるため、言い換えると、光拡散距離Dが小さくなるため、輝度ムラを抑制できるようにするには、隣接し合う蛍光管2同士の距離pを所定距離以下にする必要がある。即ち、図3,図4に示すpの寸法を所定距離以下にする必要がある。万一、隣接し合う蛍光管2同士の距離pが所定距離よりも大きくなると、前述の通り、蛍光管2の発光部が輝度ムラとして見えるという不具合が発生するからである。なお、従来の液晶表示装置では、特許第3642723号公報の段落0018に記載の通り、照明装置(バックライト装置)の厚みは20mmであったことにより、光拡散距離Dが20mm弱であったため、つまり、照明装置が薄型化されていなかったことで、前述の不具合が発生することがなかった。
<3. Suppression of luminance unevenness in the liquid crystal display device of the present embodiment>
Next, suppression of luminance unevenness in the liquid crystal display device 1 of the present embodiment will be described.
In the liquid crystal display device 1 of the present embodiment, the distance D from the reflection sheet 5 to the diffusion plate 11 is reduced by reducing the thickness of the lighting device including the fluorescent tube 2, the reflection sheet 5, the diffusion plate 11, the four optical sheets 12, and the like. In other words, since the light diffusion distance D is reduced, the distance p between the adjacent fluorescent tubes 2 needs to be set to a predetermined distance or less in order to suppress luminance unevenness. That is, the dimension p shown in FIGS. 3 and 4 needs to be a predetermined distance or less. This is because, if the distance p between the adjacent fluorescent tubes 2 is larger than a predetermined distance, the light emitting portion of the fluorescent tube 2 appears as luminance unevenness as described above. In the conventional liquid crystal display device, as described in paragraph 0018 of Japanese Patent No. 3642723, since the thickness of the illumination device (backlight device) was 20 mm, the light diffusion distance D was less than 20 mm. In other words, the above-described problems did not occur because the lighting device was not thinned.

更に、隣接し合う蛍光管2同士の距離pを所定距離以下にする以外にも、輝度ムラを抑制するためには、反射シート5の上部端面5aと傾斜面5bとの境界からこの境界に最も近い蛍光管2までの距離eを所定距離以下にする必要がある。即ち、図3,図4に示すeの寸法を所定距離以下にする必要がある。万一、反射シート5の上部端面5aと傾斜面bとの境界からこの境界に最も近い蛍光管2までの距離eが所定距離よりも大きくなると、前述の通り、液晶パネル3の画面縦方向での両端部近傍の輝度が中央付近の輝度よりも低くなることにより、液晶パネル3の画面縦方向での両端部近傍が中央付近に比べて暗くなるという不具合が発生するからである。なお、反射シート5が傾斜面5bを有するようにしたのは、特許第3642723号公報の段落0034に記載の通り、液晶パネル3側の方向に向けて白色光を集光させるためである。   Further, in order to suppress luminance unevenness other than setting the distance p between adjacent fluorescent tubes 2 to be equal to or less than a predetermined distance, the boundary between the upper end surface 5a and the inclined surface 5b of the reflection sheet 5 is the most from this boundary. The distance e to the near fluorescent tube 2 needs to be a predetermined distance or less. That is, the dimension e shown in FIGS. 3 and 4 needs to be a predetermined distance or less. If the distance e from the boundary between the upper end surface 5a and the inclined surface b of the reflection sheet 5 to the fluorescent tube 2 closest to the boundary is larger than a predetermined distance, as described above, the screen in the vertical direction of the liquid crystal panel 3 This is because the luminance in the vicinity of both ends of the liquid crystal panel is lower than the luminance in the vicinity of the center, thereby causing a problem that the vicinity of both ends in the vertical direction of the liquid crystal panel 3 is darker than the vicinity of the center. The reason why the reflective sheet 5 has the inclined surface 5b is to collect white light toward the liquid crystal panel 3 side as described in paragraph 0034 of Japanese Patent No. 3642723.

なお、以下、隣接し合う蛍光管2同士の距離pを蛍光管ピッチp、反射シート5の上部端面5aと傾斜面5bとの境界からこの境界に最も近い蛍光管2までの距離eをバックライト上下端から端部側蛍光管までの距離eと称する。   Hereinafter, the distance p between the adjacent fluorescent tubes 2 is defined as the fluorescent tube pitch p, and the distance e from the boundary between the upper end surface 5a and the inclined surface 5b of the reflection sheet 5 to the fluorescent tube 2 closest to the boundary is defined as the backlight. It is called a distance e from the upper and lower ends to the end side fluorescent tube.

そして、各光拡散距離Dにおいて、輝度ムラを抑制することができる蛍光管ピッチp及びバックライト上下端から端部側蛍光管までの距離eを、実験で導出した。この実験により、光拡散距離Dが7〜13mmにおいて、下記(1)式及び(2)式を満たすように、蛍光管ピッチp及びバックライト上下端から端部側蛍光管までの距離eを設定することにより、輝度ムラを抑制することができることが判明した。なお、輝度ムラを抑制することができるとは、蛍光管2の発光部が輝度ムラとして見えるという不具合を除去することができると共に、図6の通り、液晶パネル3の縦寸法の10%だけ液晶パネル3の下端から上方の位置での輝度と、液晶パネル3の縦寸法の10%だけ液晶パネル3の上端から下方の位置での輝度とが中央付近の輝度の70%以上にすることである。   And in each light diffusion distance D, the fluorescent tube pitch p which can suppress a brightness nonuniformity, and the distance e from the backlight upper and lower ends to the edge part side fluorescent tube were derived | led-out by experiment. By this experiment, when the light diffusion distance D is 7 to 13 mm, the fluorescent tube pitch p and the distance e from the upper and lower ends of the backlight to the end side fluorescent tube are set so as to satisfy the following equations (1) and (2). By doing so, it has been found that luminance unevenness can be suppressed. In addition, the fact that the luminance unevenness can be suppressed can eliminate the problem that the light emitting portion of the fluorescent tube 2 appears as luminance unevenness, and the liquid crystal is 10% of the vertical dimension of the liquid crystal panel 3 as shown in FIG. The brightness at the position above the lower end of the panel 3 and the brightness at the position below the upper end of the liquid crystal panel 3 by 10% of the vertical dimension of the liquid crystal panel 3 should be 70% or more of the brightness near the center. .

p≦1.34×D+9 ………(1)
e≦1.6×D+4 ………(2)
p:蛍光管ピッチ
e:バックライト上下端から端部側蛍光管までの距離
D:光拡散距離
p ≦ 1.34 × D + 9 (1)
e ≦ 1.6 × D + 4 (2)
p: fluorescent tube pitch e: distance from the upper and lower ends of the backlight to the end side fluorescent tube D: light diffusion distance

図6は、本実施形態の液晶表示装置における液晶パネルの画面縦方向位置と輝度との関係を示す図である。輝度ムラを抑制することができることに関し、前述の通りに定義する理由は、一般にテレビとして用いられる液晶パネルでは、縦寸法の10%だけ下端から上方での輝度と、縦寸法の10%だけ上端から下方での輝度は、中央の輝度の70〜80%であるからである。   FIG. 6 is a diagram showing the relationship between the vertical position of the liquid crystal panel and the luminance in the liquid crystal display device of this embodiment. With respect to the ability to suppress luminance unevenness, the reason for defining as described above is that, in a liquid crystal panel generally used as a television, the luminance is 10% of the vertical dimension from the lower end and the upper part is 10% of the vertical dimension from the upper end. This is because the lower luminance is 70 to 80% of the central luminance.

<4.最適な蛍光管ピッチ及びバックライト上下端から端部側蛍光管までの距離の導出>
以下、輝度ムラを抑制することができる蛍光管ピッチp及びバックライト上下端から端部側蛍光管までの距離eの、実験による導出について説明する。
<4. Derivation of the optimal fluorescent tube pitch and the distance from the upper and lower ends of the backlight to the end side fluorescent tube>
Hereinafter, derivation by experiment of the fluorescent tube pitch p capable of suppressing luminance unevenness and the distance e from the upper and lower ends of the backlight to the end side fluorescent tube will be described.

(4.1 最適な蛍光管ピッチpの導出)
まず、輝度ムラを抑制することができる蛍光管ピッチpの、実験による導出について説明する。実験では、光拡散距離Dを5mmから17mmまで変えたときの、それぞれの光拡散距離Dで、輝度ムラを抑制することができる蛍光管ピッチpを導出する。具体的には、光拡散距離Dが5mm,6mm,7mm,8mm,9mm,10mm,11mm,12mm,13mm,14mm,15mm,17mmのそれぞれの値のときに、蛍光管ピッチpを設定する毎に、輝度ムラが抑制することができるか否かの実験を行うのを繰り返すことにより、それぞれの光拡散距離Dで、輝度ムラを抑制することができる蛍光管ピッチpを導出する。実験条件を図7に、実験結果を図8に示す。図8より、光拡散距離Dが7〜13mmでは、光拡散距離Dと輝度ムラpとが上記(1)式を満たす関係であれば、蛍光管の発光部が輝度ムラとして見えるという不具合を除去できることが判明した。
(4.1 Derivation of optimum fluorescent tube pitch p)
First, experimental derivation of the fluorescent tube pitch p capable of suppressing luminance unevenness will be described. In the experiment, a fluorescent tube pitch p capable of suppressing luminance unevenness is derived at each light diffusion distance D when the light diffusion distance D is changed from 5 mm to 17 mm. Specifically, whenever the light diffusion distance D is 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, and 17 mm, each time the fluorescent tube pitch p is set. By repeating the experiment on whether or not the luminance unevenness can be suppressed, the fluorescent tube pitch p capable of suppressing the luminance unevenness is derived at each light diffusion distance D. The experimental conditions are shown in FIG. 7, and the experimental results are shown in FIG. From FIG. 8, when the light diffusion distance D is 7 to 13 mm, if the light diffusion distance D and the luminance unevenness p satisfy the above equation (1), the problem that the light emitting portion of the fluorescent tube appears as luminance unevenness is eliminated. It turns out that you can.

一方、液晶パネルの画面縦方向での両端部近傍での輝度の低下の不具合については、バックライト上下端から端部側蛍光管までの距離eを実験により得た最適値に設定することにより、除去する。即ち、下記に記載の輝度ムラを抑制することができるバックライト上下端から端部側蛍光管までの距離eの、実験による導出によって得た最適値に設定することにより、除去する。   On the other hand, for the problem of the decrease in brightness near both ends in the screen vertical direction of the liquid crystal panel, by setting the distance e from the upper and lower ends of the backlight to the end side fluorescent tube to the optimum value obtained by experiment, Remove. That is, it is eliminated by setting the distance e from the upper and lower ends of the backlight to the end side fluorescent tube that can suppress the luminance unevenness described below to an optimum value obtained by derivation by experiment.

(4.2 最適なバックライト上下端から端部側蛍光管までの距離eの導出)
次に、輝度ムラを抑制することができるバックライト上下端から端部側蛍光管までの距離eの、実験による導出について説明する。具体的には、光拡散距離Dが5mm,6mm,7mm,8mm,9mm,10mm,11mm,12mm,13mm,14mm,15mm,17mmのそれぞれの値のときに、バックライト上下端から端部側蛍光管までの距離eを設定する毎に、輝度ムラを抑制することができるか否かの実験を行うのを繰り返すことにより、それぞれの光拡散距離Dで、輝度ムラを抑制することができるバックライト上下端から端部側蛍光管までの距離eを導出する。実験条件を図9に、実験結果を図8に示す。図8より、光拡散距離Dが7〜13mmでは、光拡散距離Dとバックライト上下端から端部側蛍光管までの距離eとが上記(2)式を満たす関係であれば、液晶パネルの画面縦方向での両端部近傍での輝度が低下するという不具合を除去できることが判明した。
(4.2 Derivation of the distance e from the upper and lower ends of the optimal backlight to the end side fluorescent tube)
Next, the derivation of the distance e from the upper and lower ends of the backlight to the end side fluorescent tube capable of suppressing luminance unevenness by experiment will be described. Specifically, when the light diffusion distance D is 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, and 17 mm, the fluorescence from the upper and lower ends of the backlight to the end side fluorescence. Each time the distance e to the tube is set, a backlight that can suppress the luminance unevenness at each light diffusion distance D by repeating the experiment whether the luminance unevenness can be suppressed or not is repeated. A distance e from the upper and lower ends to the end side fluorescent tube is derived. The experimental conditions are shown in FIG. 9, and the experimental results are shown in FIG. From FIG. 8, when the light diffusion distance D is 7 to 13 mm, if the light diffusion distance D and the distance e from the upper and lower ends of the backlight to the end side fluorescent tube satisfy the above equation (2), It has been found that the problem that the luminance near the both ends in the vertical direction of the screen is reduced can be eliminated.

(4.3 まとめ)
以上の通り、光拡散距離Dが7〜13mmにおいて、上記(1)式及び(2)式を満たすように、蛍光管ピッチp及びバックライト上下端から端部側蛍光管までの距離eを設定することにより、蛍光管の発光部が輝度ムラとして見えるという不具合を除去できると共に、液晶パネルの画面縦方向での両端部近傍での輝度が低下するという不具合を除去できる。その結果、光拡散距離Dが20mm弱から7〜13mmになることで照明装置が薄型化しても、輝度ムラを抑制することができる。
(4.3 Summary)
As described above, when the light diffusion distance D is 7 to 13 mm, the fluorescent tube pitch p and the distance e from the upper and lower ends of the backlight to the end side fluorescent tube are set so as to satisfy the above formulas (1) and (2). By doing so, it is possible to remove the problem that the light emitting part of the fluorescent tube appears as luminance unevenness, and it is possible to eliminate the problem that the luminance in the vicinity of both ends in the vertical direction of the liquid crystal panel is lowered. As a result, even if the lighting device is thinned by the light diffusion distance D being less than 20 mm to 7 to 13 mm, uneven brightness can be suppressed.

<5.その他の実施形態の液晶表示装置>
前述の実施形態の液晶表示装置以外の液晶表示装置でも、上記(1)式及び上記(2)式を満たすように、蛍光管ピッチp及びバックライト上下端から端部側蛍光管までの距離eを設定することにより、光拡散距離Dを20mm弱から7〜13mmにすることで照明装置が薄型化しても、輝度ムラを抑制することができる。なお、図3,図4の通り、蛍光管ピッチp、バックライト上下端から端部側蛍光管までの距離e、蛍光管の本数N、バックライト縦方向長さLとの間には、下記(3)式に示す関係があることにより、下記(3)式に上記(1)式及び上記(2)式を代入することにより、下記(4)式を導出することができる。
<5. Liquid Crystal Display Device of Other Embodiment>
Even in a liquid crystal display device other than the liquid crystal display device of the above-described embodiment, the fluorescent tube pitch p and the distance e from the upper and lower ends of the backlight to the end side fluorescent tube so as to satisfy the above formulas (1) and (2). By setting the light diffusion distance D from slightly less than 20 mm to 7 to 13 mm, uneven brightness can be suppressed even if the lighting device is thinned. As shown in FIGS. 3 and 4, between the fluorescent tube pitch p, the distance e from the upper and lower ends of the backlight to the end side fluorescent tube, the number N of fluorescent tubes, and the longitudinal length L of the backlight are as follows. Due to the relationship shown in the equation (3), the following equation (4) can be derived by substituting the above equation (1) and the above equation (2) into the following equation (3).

N=(L−2×e)/p+1 ………(3)
N:蛍光管の本数
L:バックライト縦方向長さ
e:バックライト上下端から端部側蛍光管までの距離
p:蛍光管ピッチ
N≧{L−(3.2×D+8)}/(1.34×D+9)+1 ………(4)
N:蛍光管の本数
L:バックライト縦方向長さ
D:光拡散距離
N = (L−2 × e) / p + 1 (3)
N: Number of fluorescent tubes L: Backlight longitudinal length e: Distance from upper and lower ends of backlight to end side fluorescent tube p: Fluorescent tube pitch N ≧ {L− (3.2 × D + 8)} / (1 .34 × D + 9) +1 (4)
N: Number of fluorescent tubes L: Backlight vertical length D: Light diffusion distance

以下、32型(インチ)サイズ,37型(インチ)サイズ,42型(インチ)サイズで、光拡散距離Dが7〜13mmになることで照明装置が薄型化した液晶表示装置について、説明する。なお、以下、計量法の趣旨に則して、非SI単位のインチ表示は省略する。   Hereinafter, a liquid crystal display device having a 32 inch (inch) size, a 37 inch (inch) size, and a 42 inch (inch) size and having a light diffusing distance D of 7 to 13 mm to reduce the thickness of the lighting device will be described. In the following, in accordance with the gist of the Measurement Law, inch display in non-SI units is omitted.

(5.1 32型サイズの液晶表示装置)
32型サイズの液晶表示装置では、バックライト縦方向長さL=398mmである。光拡散距離D=9.3mmとした場合、上記(1)〜(4)式より、蛍光管ピッチp≦21.46mm、バックライト上下端から端部側蛍光管までの距離e≦18.88mm、蛍光管の本数N≧17.79となる。そこで、光拡散距離D=9.3mmとすることで照明装置を薄型化しても、例えば、蛍光管の本数N=18本、蛍光管ピッチp=21.4mm、バックライト上下端から端部側蛍光管までの距離e=17.1mmに設定することにより、32型サイズの液晶表示装置で、輝度ムラを抑制することができる。
(5.1 32 inch size liquid crystal display device)
In the 32-type liquid crystal display device, the backlight length L is 398 mm. When the light diffusion distance D = 9.3 mm, from the above formulas (1) to (4), the fluorescent tube pitch p ≦ 21.46 mm, and the distance e ≦ 18.88 mm from the upper and lower ends of the backlight to the end side fluorescent tube. The number of fluorescent tubes N ≧ 17.79. Therefore, even if the illuminating device is thinned by setting the light diffusion distance D = 9.3 mm, for example, the number of fluorescent tubes N = 18, the fluorescent tube pitch p = 21.4 mm, and the end side from the upper and lower ends of the backlight By setting the distance e to the fluorescent tube at e = 17.1 mm, it is possible to suppress luminance unevenness in a 32-type liquid crystal display device.

(5.2 37型サイズの液晶表示装置)
37型サイズの液晶表示装置では、バックライト縦方向長さL=467.4mmである。光拡散距離D=10mmとした場合、上記(1)〜(4)式より、蛍光管ピッチp≦22.4mm、バックライト上下端から端部側蛍光管までの距離e≦20mm、蛍光管の本数N≧20.1となる。そこで、光拡散距離D=10mmとすることで照明装置を薄型化しても、例えば、蛍光管の本数N=21本、蛍光管ピッチp=22mm、バックライト上下端から端部側蛍光管までの距離e=13.7mmに設定することにより、37型サイズの液晶表示装置では、輝度ムラを抑制することができる。
(5.2 37-inch size liquid crystal display device)
In the 37-type liquid crystal display device, the backlight length L is 467.4 mm. When the light diffusion distance D = 10 mm, from the above formulas (1) to (4), the fluorescent tube pitch p ≦ 22.4 mm, the distance e ≦ 20 mm from the upper and lower ends of the backlight to the end side fluorescent tube, The number N ≧ 20.1. Therefore, even if the illuminating device is thinned by setting the light diffusion distance D = 10 mm, for example, the number of fluorescent tubes N = 21, the fluorescent tube pitch p = 22 mm, and from the upper and lower ends of the backlight to the end side fluorescent tubes By setting the distance e = 13.7 mm, luminance unevenness can be suppressed in the 37-type liquid crystal display device.

(5.3 42型サイズの液晶表示装置)
42型サイズの液晶表示装置では、バックライト縦方向長さL=524mmである。光拡散距離D=11mmとした場合、上記(1)〜(4)式より、蛍光管ピッチp≦23.74mm、バックライト上下端から端部側蛍光管までの距離e≦21.6mm、蛍光管の本数N≧21.25となる。そこで、例えば、光拡散距離D=11mmとすることで照明装置を薄型化しても、蛍光管の本数N=22本、蛍光管ピッチp=23mm、バックライト上下端から端部側蛍光管までの距離e=20.5mmに設定することにより、42型サイズの液晶表示装置では、輝度ムラを抑制することができる。
(5.3 42-inch size liquid crystal display device)
In the 42 type liquid crystal display device, the backlight length L is 524 mm. When the light diffusion distance D = 11 mm, from the above formulas (1) to (4), the fluorescent tube pitch p ≦ 23.74 mm, the distance e ≦ 21.6 mm from the upper and lower ends of the backlight to the end side fluorescent tube, The number of tubes N ≧ 21.25. Therefore, for example, even if the illuminating device is thinned by setting the light diffusion distance D = 11 mm, the number of fluorescent tubes N = 22, the fluorescent tube pitch p = 23 mm, and from the upper and lower ends of the backlight to the end side fluorescent tubes By setting the distance e = 20.5 mm, the luminance unevenness can be suppressed in the 42 type liquid crystal display device.

1:液晶表示装置
2:蛍光管
2a:電極
3:液晶パネル
4:下フレーム
5:反射シート
5a:上部端面
5b:傾斜面
7:下サイドモールド
8:電極ホルダ
9:上サイドモールド
11:拡散板
11′:パターン付き拡散板
12:光学シート
13:中間フレーム
13a:溝
14:上フレーム
15:インバータ
1: Liquid crystal display device 2: Fluorescent tube 2a: Electrode 3: Liquid crystal panel 4: Lower frame 5: Reflective sheet 5a: Upper end surface 5b: Inclined surface 7: Lower side mold 8: Electrode holder 9: Upper side mold 11: Diffusion plate 11 ': Patterned diffusion plate 12: Optical sheet 13: Intermediate frame 13a: Groove 14: Upper frame 15: Inverter

Claims (3)

画像を表示する液晶パネルと、
該液晶パネルの背面に配置され、前記液晶パネルに光を出射する照明装置とを有し、
該照明装置は、前記液晶パネルの画面横方向に略平行に配置された複数の線状光源と、
該線状光源の背面に配置され、前記線状光源からの光を拡散して反射する反射部材と、
前記線状光源の正面に配置され、前記線状光源からの光を拡散して透過する拡散透過部材とを有する液晶表示装置において、
前記反射部材と前記拡散透過部材との距離Dは、7〜13mmであり、
各前記線状光源間の距離p(mm)と、前記反射部材と前記拡散透過部材との距離D(mm)とは、p≦1.34×D+9の関係式を満たすと共に、
前記液晶パネルの画面縦方向での前記反射部材の端部に最も近い前記線状光源と前記反射部材の端部との距離e(mm)と、前記反射部材と前記拡散透過部材との前記距離D(mm)とは、13.7≦e≦1.6×D+4の関係式を満たし、
前記拡散透過部材は、前記液晶パネル側の面が凹凸形状であるパターン付き拡散透過部材であり、
前記パターン付き拡散透過部材の正面に配置される光学シートは、少なくとも2枚の拡散シートと1枚の集光フィルムを含み、
前記反射部材は端部において傾斜面を有し、前記反射部材と前記線状光源の中心軸との距離は2.8mm以下である
ことを特徴とする液晶表示装置。
A liquid crystal panel for displaying images;
An illuminating device disposed on the back surface of the liquid crystal panel and emitting light to the liquid crystal panel;
The lighting device includes a plurality of linear light sources arranged substantially parallel to a horizontal direction of the screen of the liquid crystal panel,
A reflective member that is disposed on the back surface of the linear light source and diffuses and reflects light from the linear light source;
In a liquid crystal display device that is disposed in front of the linear light source and has a diffusion transmission member that diffuses and transmits light from the linear light source,
The distance D between the reflection member and the diffuse transmission member is 7 to 13 mm,
The distance p (mm) between the linear light sources and the distance D (mm) between the reflecting member and the diffuse transmitting member satisfy the relational expression p ≦ 1.34 × D + 9,
The distance e (mm) between the linear light source closest to the end of the reflecting member in the screen vertical direction of the liquid crystal panel and the end of the reflecting member, and the distance between the reflecting member and the diffuse transmission member D (mm) satisfies the relational expression 13.7 ≦ e ≦ 1.6 × D + 4,
The diffuse transmission member is a diffuse transmission member with a pattern in which the surface on the liquid crystal panel side has an uneven shape,
The optical sheet disposed on the front surface of the patterned diffuse transmission member includes at least two diffusion sheets and one light collecting film,
The reflective member has an inclined surface at an end, and a distance between the reflective member and the central axis of the linear light source is 2.8 mm or less.
請求項1記載の液晶表示装置において、
前記光学シートは、前記2枚の拡散シートと1枚の集光フィルムの他、少なくとも1枚の拡散シートまたは1枚の偏光反射フィルムを含む
ことを特徴とする液晶表示装置。
The liquid crystal display device according to claim 1.
The optical sheet includes at least one diffusion sheet or one polarizing reflection film in addition to the two diffusion sheets and one condensing film.
液晶パネルの画面横方向に略平行に配置され、光を出射する複数の線状光源と、
該線状光源の背面に配置され、前記線状光源からの光を拡散して反射する反射部材と、
前記線状光源の正面に配置され、前記線状光源からの光を拡散して透過する拡散透過部材とを有する照明装置において、
前記反射部材と前記拡散透過部材との距離Dは、7〜13mmであり、
各前記線状光源間の距離p(mm)と、前記反射部材と前記拡散透過部材との距離D(mm)とは、p≦1.34×D+9の関係式を満たすと共に、
前記液晶パネルの画面縦方向での前記反射部材の端部に最も近い前記線状光源と前記反射部材の端部との距離e(mm)と、前記反射部材と前記拡散透過部材との前記距離D(mm)とは、13.7≦e≦1.6×D+4の関係式を満たし、
前記拡散透過部材は、前記液晶パネル側の面が凹凸形状であるパターン付き拡散透過部材であり、
前記パターン付き拡散透過部材の正面に配置される光学シートは、少なくとも2枚の拡散シートと1枚の集光フィルムを含み、
前記反射部材は端部において傾斜面を有し、前記反射部材と前記線状光源の中心軸との距離は2.8mm以下である
ことを特徴とする照明装置。
A plurality of linear light sources that are arranged substantially parallel to the horizontal direction of the screen of the liquid crystal panel and emit light;
A reflective member that is disposed on the back surface of the linear light source and diffuses and reflects light from the linear light source;
In the illuminating device that is disposed in front of the linear light source and has a diffusion transmission member that diffuses and transmits light from the linear light source,
The distance D between the reflection member and the diffuse transmission member is 7 to 13 mm,
The distance p (mm) between the linear light sources and the distance D (mm) between the reflecting member and the diffuse transmitting member satisfy the relational expression p ≦ 1.34 × D + 9,
The distance e (mm) between the linear light source closest to the end of the reflecting member in the screen vertical direction of the liquid crystal panel and the end of the reflecting member, and the distance between the reflecting member and the diffuse transmission member D (mm) satisfies the relational expression 13.7 ≦ e ≦ 1.6 × D + 4,
The diffuse transmission member is a diffuse transmission member with a pattern in which the surface on the liquid crystal panel side has an uneven shape,
The optical sheet disposed in front of the diffuse diffusion member with the pattern includes at least two diffusion sheets and one light collecting film,
The reflection member has an inclined surface at an end, and a distance between the reflection member and a central axis of the linear light source is 2.8 mm or less.
JP2009183984A 2009-08-07 2009-08-07 Liquid crystal display device and illumination device Withdrawn JP2010033058A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9383079B2 (en) 2013-07-24 2016-07-05 Samsung Display Co., Ltd. Backlight unit and display apparatus having the same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9383079B2 (en) 2013-07-24 2016-07-05 Samsung Display Co., Ltd. Backlight unit and display apparatus having the same

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