JP3820159B2

JP3820159B2 - Daylighting board

Info

Publication number: JP3820159B2
Application number: JP2002012434A
Authority: JP
Inventors: 望松本
Original assignee: Kenwood KK
Current assignee: Kenwood KK
Priority date: 2002-01-22
Filing date: 2002-01-22
Publication date: 2006-09-13
Anticipated expiration: 2022-01-22
Also published as: JP2003215347A

Description

【０００１】
【発明の属する技術分野】
この発明はＬＣＤ（液晶ディスプレイ）やパネルの照光面等を照光するための採光板に係わり、特に、省スペース化され、しかも照光部分を均一に照明することができる採光板に関する。
【０００２】
【従来の技術】
従来のＬＣＤ（液晶ディスプレイ）やパネルの照光面等を照光する採光板の例を図３に示す。図に示す採光板８の両側面に光源となるＬＥＤ６、６が配置されている。なお図示していないが、採光板８の下面および両側面には反射板が配置され、上面には散光板が配置され、その上にＬＣＤ（液晶ディスプレイ）やパネルの照光面が配置される。ＬＥＤ６、６から出射された光は採光板や反射板で散光板に導かれ、散光板で拡散されて照光面を照明する。
【０００３】
特開平６−１２３８１０号公報に提案された採光板は採光板の一方の側に光源を配置し、採光板の底面に複数の凹溝条を設けており、この凹溝条は光源に近くなるにつれて浅くなるように形成されている。
【０００４】
特開平１０−３９３０２号公報に提案された採光板は採光板の一方の側または両側に光源を配置し、採光板の底面に複数の凹溝条を設けており、この凹溝条の傾斜角を光源からの距離により変化させている。
【０００５】
特開平１０−２５４３７１号公報に提案された採光板は採光板の一方の側に光源を配置し、採光板の底面を傾斜させて光源から遠くなるにつれて採光板の肉厚が薄くなるように変化させ、採光板の光放射面の上に断面鋸歯状のプリズムシートを配置している。
【０００６】
【発明が解決しようとする課題】
上記した従来の両側面に光源を配置した採光板は部品点数が多くなる上に光源と採光板とが占めるスペースが大きくなり、設計上の自由度が小さくなる。また、照光するＬＣＤの大きさが制限されるという問題があった。
【０００７】
採光板の一方の側に光源を配置するものは、光を均一に拡散するために種々の技法が用いられているが、採光板の光放射面には光源方向からのみ光が導かれるために光源に近い所から遠い所に亘り均一に照光面を照射することが困難であった。
【０００８】
この発明は上記した点に鑑みてなされたものであって、その目的とするところは、採光板の一方の側に光源を配置し、しかも、容易に光源に近い所から遠い所に亘り均一に照光面を照射することができる採光板を提供することにある。
【０００９】
【課題を解決するための手段】
この発明の採光板は、照光面に対向配置される略長方形の板状の導光体の１方の側面に光源を配置し、他方の側面に前記導光体の底面に対して鈍角をなす下側反射面と前記底面に対して鋭角をなす上側反射面を形成すると共に、前記照光面と対向する前記導光体の光放射面を前記光源の側から前記下側反射面および上側反射面の側に向けて前記照光面と反対方向に下がるように形成して前記１方の側面と平行に伸びる複数のＶ字形溝を設け、前記光放射面の下がりきった位置から前記底面に対して垂直に立上がる光出射面を設け、前記光源から前記導光体を通り直接前記光放射面の内面に至った光を前記光放射面で前記照光面に向けて屈折させ、前記光源から前記導光体の下方を通り前記下側反射面で内部反射され、さらに前記上側反射面で内部反射されて前記光出射面の内部に至った光を前記光出射面から出射させて前記光放射面の外面に至った光を前記光放射面で前記照光面に向けて反射させるように構成したものである。
【００１０】
また、前記採光板において、前記１方の側面に凹みを設け、前記凹みに突入するように光源が配置されるものである。
【００１１】
また、前記各採光板において、前記光源としてＬＥＤが用いられるものである。
【００１２】
【発明の実施の形態】
この発明の実施例である採光板例を図面に基づいて説明する。図１はこの発明の実施例である採光板を示す平面図であり、図２は図１におけるＡ−Ａ断面図である。図において、略長方形の板状導光体で作られた採光板１は一方の側面に凹み５が設けられており、凹み５に光源となるＬＥＤ６が配置される。採光板１の他方の側面には４５°に傾斜した反射面４、４が上下に形成されている。
【００１３】
採光板１の底面は平面状に形成され、上面に光源から離れるに従って低くなる光放射面２が形成されている。光放射面２には、長手方向に対して直角方向に延びるＶ字形溝３、３…が形成されている。Ｖ字形溝３、３…は図１および図２の全体図では一部のみを簡略化して示しているが、Ａ部拡大図に示す形状のものが光放射面２全体に形成されている。
【００１４】
ＬＥＤ６から採光板１の内部を通り直接光放射面２の内面に至った光は光放射面２で屈折され矢印で示すようにＬＣＤや表示板等の照光面７に向けて放射される。ＬＥＤ６から採光板１の内部の下方を通り反射面４に至った光は反射面４、４で反射され矢印で示すように光放射面２の外面に至った光は光放射面２で反射されて照光面７に向けて放射される。
【００１５】
Ｖ字形溝３、３…は光放射面２で屈折または反射される光を拡散させて光むらをなくす。ＬＥＤ６を配置する部分に凹み５が設けられているために、いわゆる点光源であっても照光面７を幅方向に均一に照明することができる。
【００１６】
光放射面２には光源側および光源と反対側の両方向から光が導かれるので照光面７を長手方向に対して均一に照明することができる。
【００１７】
実施例は以上のように構成されているが発明はこれに限られず、例えば、光源としてＬＥＤの代わりにランプを用いることも可能である。また、実施例では図示していなかったが、採光板１の底面および側面に反射板を配置してもよい。
【００１８】
【発明の効果】
この発明の採光板によれば、部品点数が削減され、製造コストが安くなり、しかも、照光面を均一に照明することができる。
【００１９】
また、光源と採光板とが占めるスペースが小さくなり、照明するＬＣＤ等を大きくすることができる。
【図面の簡単な説明】
【図１】この発明の実施例である採光板を示す平面図である。
【図２】図１におけるＡ−Ａ断面図である。
【図３】従来の採光板の例を示す平面図である。
【符号の説明】
１採光板
２光放射面
３Ｖ字形溝
４反射面
５凹み
６ＬＥＤ
７照光面
８採光板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lighting plate for illuminating an illumination surface of an LCD (liquid crystal display) or a panel, and more particularly to a lighting plate that is space-saving and that can uniformly illuminate an illuminated portion.
[0002]
[Prior art]
FIG. 3 shows an example of a daylighting plate that illuminates a conventional LCD (liquid crystal display), an illumination surface of a panel, and the like. LEDs 6 and 6 serving as light sources are arranged on both side surfaces of the daylighting plate 8 shown in the drawing. Although not shown, a reflecting plate is disposed on the lower surface and both side surfaces of the daylighting plate 8, a light diffusing plate is disposed on the upper surface, and an illumination surface of an LCD (liquid crystal display) or panel is disposed thereon. The light emitted from the LEDs 6 and 6 is guided to the light diffusing plate by the daylighting plate or the reflecting plate, and is diffused by the light diffusing plate to illuminate the illumination surface.
[0003]
The daylighting plate proposed in Japanese Patent Laid-Open No. 6-123810 has a light source disposed on one side of the daylighting plate, and a plurality of grooves are provided on the bottom surface of the daylighting plate, and these grooves are close to the light source. It is formed so as to become shallower.
[0004]
In the daylighting plate proposed in Japanese Patent Laid-Open No. 10-39302, a light source is arranged on one side or both sides of the daylighting plate, and a plurality of grooves are provided on the bottom surface of the daylighting plate. Is changed according to the distance from the light source.
[0005]
The daylighting plate proposed in Japanese Patent Application Laid-Open No. 10-254371 has a light source disposed on one side of the daylighting plate, and the bottom surface of the daylighting plate is inclined so that the thickness of the daylighting plate decreases as the distance from the light source increases. A prism sheet having a sawtooth cross section is arranged on the light emitting surface of the daylighting plate.
[0006]
[Problems to be solved by the invention]
The above-described conventional daylighting plate in which light sources are arranged on both side surfaces increases the number of components and increases the space occupied by the light source and the daylighting plate, thereby reducing the degree of freedom in design. In addition, there is a problem that the size of the illuminated LCD is limited.
[0007]
Various light sources are arranged on one side of the daylighting plate, and various techniques are used to diffuse the light uniformly. However, because light is guided only from the direction of the light source to the light emitting surface of the daylighting plate. It was difficult to irradiate the illumination surface uniformly from a place close to the light source to a place far away.
[0008]
The present invention has been made in view of the above points. The object of the present invention is to arrange a light source on one side of a daylighting plate, and easily and uniformly from a place close to the light source. An object of the present invention is to provide a daylighting plate capable of irradiating an illumination surface.
[0009]
[Means for Solving the Problems]
In the lighting plate according to the present invention, a light source is disposed on one side surface of a substantially rectangular plate-shaped light guide disposed to face the illumination surface, and an obtuse angle with respect to the bottom surface of the light guide is formed on the other side surface. An upper reflective surface that forms an acute angle with the lower reflective surface and the bottom surface is formed, and the light emitting surface of the light guide facing the illumination surface is changed from the light source side to the lower reflective surface and the upper reflective surface. A plurality of V-shaped grooves are formed so as to be lowered in the opposite direction to the illumination surface toward the side, and extend in parallel with the one side surface , and from the position where the light emission surface is completely lowered to the bottom surface A light emitting surface that rises vertically is provided, and light that has passed from the light source through the light guide directly to the inner surface of the light emitting surface is refracted by the light emitting surface toward the illumination surface, and is guided from the light source to the light guiding surface. It passes under the light body and is internally reflected by the lower reflective surface, and further by the upper reflective surface. The light that is partially reflected and reaches the inside of the light emitting surface is emitted from the light emitting surface, and the light that reaches the outer surface of the light emitting surface is reflected by the light emitting surface toward the illumination surface. It is a thing.
[0010]
Further, in the daylighting plate, a recess is provided on the one side surface, and a light source is disposed so as to enter the recess.
[0011]
In each of the daylighting plates, an LED is used as the light source.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An example of a daylighting plate which is an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a daylighting plate according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG. In the figure, a daylighting plate 1 made of a substantially rectangular plate-shaped light guide is provided with a recess 5 on one side surface, and an LED 6 serving as a light source is disposed in the recess 5. On the other side surface of the daylighting plate 1, reflecting surfaces 4, 4 inclined at 45 ° are formed vertically.
[0013]
The bottom surface of the daylighting plate 1 is formed in a flat shape, and the light emitting surface 2 that becomes lower as the distance from the light source increases on the upper surface. On the light emitting surface 2, V-shaped grooves 3, 3... Extending in a direction perpendicular to the longitudinal direction are formed. The V-shaped grooves 3, 3... Are simplified in part in the overall views of FIGS. 1 and 2, but the shape shown in the enlarged view of the A part is formed on the entire light emitting surface 2.
[0014]
Light that has passed through the inside of the lighting plate 1 from the LED 6 and directly reaches the inner surface of the light emitting surface 2 is refracted by the light emitting surface 2 and is emitted toward an illumination surface 7 such as an LCD or a display plate as indicated by an arrow. The light from the LED 6 passing through the inside of the lighting plate 1 to the reflecting surface 4 is reflected by the reflecting surfaces 4 and 4, and the light reaching the outer surface of the light emitting surface 2 is reflected by the light emitting surface 2 as indicated by arrows. Are emitted toward the illumination surface 7 .
[0015]
The V-shaped grooves 3, 3,... Diffuse light refracted or reflected by the light emitting surface 2 to eliminate light unevenness. Since the recess 5 is provided in the portion where the LED 6 is disposed, even the so-called point light source can uniformly illuminate the illumination surface 7 in the width direction.
[0016]
Since light is guided to the light emitting surface 2 from both the light source side and the direction opposite to the light source, the illumination surface 7 can be illuminated uniformly in the longitudinal direction.
[0017]
The embodiment is configured as described above, but the invention is not limited to this. For example, it is possible to use a lamp instead of an LED as a light source. Further, although not shown in the embodiment, a reflecting plate may be disposed on the bottom surface and the side surface of the daylighting plate 1.
[0018]
【The invention's effect】
According to the lighting plate of the present invention, the number of parts is reduced, the manufacturing cost is reduced, and the illumination surface can be illuminated uniformly.
[0019]
In addition, the space occupied by the light source and the daylighting plate is reduced, and the illuminated LCD or the like can be enlarged.
[Brief description of the drawings]
FIG. 1 is a plan view showing a daylighting plate according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA in FIG.
FIG. 3 is a plan view showing an example of a conventional daylighting plate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Daylight board 2 Light emission surface 3 V-shaped groove | channel 4 Reflective surface 5 Recess 6 LED
7 Illumination surface 8 Daylighting plate

Claims

A light source is disposed on one side surface of a substantially rectangular plate-shaped light guide disposed to face the illumination surface, and a lower reflective surface and the bottom surface form an obtuse angle with respect to the bottom surface of the light guide on the other side surface. An upper reflection surface that forms an acute angle with respect to the illumination surface, and the light emission surface of the light guide opposite to the illumination surface is directed from the light source side toward the lower reflection surface and the upper reflection surface. A plurality of V-shaped grooves formed so as to descend in a direction opposite to the surface and extending in parallel with the one side surface , and a light emitting surface that rises perpendicularly to the bottom surface from a position where the light emitting surface is completely lowered Refracting light directly from the light source through the light guide to the inner surface of the light emitting surface toward the illumination surface at the light emitting surface, and passing from below the light guide through the light source. The light is internally reflected by the lower reflective surface and further internally reflected by the upper reflective surface. Daylight plate configured to reflect toward the illumination surface the light that has reached the inside of the elevation plane light reaches the outer surface of the light emitting surface is emitted from the light emitting surface at the light emitting surface.

The daylighting plate according to claim 1, wherein a recess is provided on the one side surface, and a light source is disposed so as to enter the recess.

The daylighting plate according to claim 1, wherein an LED is used as the light source.