JP2003114337A - Illuminator - Google Patents
IlluminatorInfo
- Publication number
- JP2003114337A JP2003114337A JP2001306723A JP2001306723A JP2003114337A JP 2003114337 A JP2003114337 A JP 2003114337A JP 2001306723 A JP2001306723 A JP 2001306723A JP 2001306723 A JP2001306723 A JP 2001306723A JP 2003114337 A JP2003114337 A JP 2003114337A
- Authority
- JP
- Japan
- Prior art keywords
- light
- guide plate
- light guide
- light source
- convex portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Landscapes
- Light Guides In General And Applications Therefor (AREA)
- Liquid Crystal (AREA)
- Planar Illumination Modules (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、反射型液晶表示装
置に用いられる照明装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device used in a reflective liquid crystal display device.
【０００２】[0002]
【従来の技術】一般に液晶表示装置は、周囲が暗くとも
使用することができるように照明装置が備えられてい
る。大別すると、透過型液晶表示装置の裏側から照明す
るバックライト型照明装置と、反射型液晶表示装置の表
側から照明するフロントライト型照明装置がある。小型
携帯機器には、小型軽量化や低消費電力が求められてい
るため、表示には反射型液晶表示装置が多く利用され、
必要なときに照明することができるフロントライト型照
明装置が搭載されている。2. Description of the Related Art Generally, a liquid crystal display device is provided with an illuminating device so that it can be used even when the surroundings are dark. When roughly classified, there are a backlight type illumination device that illuminates from the back side of a transmissive liquid crystal display device and a front light type illumination device that illuminates from the front side of a reflection type liquid crystal display device. Since small mobile devices are required to be small and lightweight and have low power consumption, reflective liquid crystal display devices are often used for display.
It is equipped with a front light type lighting device that can illuminate when necessary.
【０００３】フロントライト型照明装置を実現するため
の導光板が特許第３０１２４６２号に提案されている。
この導光板の断面が図１４に示される。図１４におい
て、導光板８１の左側には光源が配置されており、光源
から射出された光は端面８５から入射して導光板８１の
中を全反射しながら伝搬する。A light guide plate for realizing a front light type illumination device is proposed in Japanese Patent No. 3012462.
The cross section of this light guide plate is shown in FIG. In FIG. 14, a light source is arranged on the left side of the light guide plate 81, and light emitted from the light source enters from the end face 85 and propagates while being totally reflected in the light guide plate 81.
【０００４】導光板８１は、平面から成る底面８６と、
底面８６と向かい合う上面とを有し、上面は複数の緩い
斜面部８７とそれらの間に位置する複数の急な斜面部８
８とを有している。緩い斜面部８７と急な斜面部８８は
共に矩形であり、従って、緩い斜面部８７と急な斜面部
８８の境界は、直線的に延びる頂線８２と谷線８３を規
定している。被照明物体は導光板８１の底面８６の下側
に設置され、観察者は導光板８１の上面の上側から導光
板８１を通して被照明物体の像を観察する。The light guide plate 81 has a flat bottom surface 86,
A bottom surface 86 and an upper surface facing each other, the upper surface having a plurality of gentle slope portions 87 and a plurality of steep slope portions 8 located therebetween.
8 and. Both the gentle slope portion 87 and the steep slope portion 88 are rectangular, and therefore the boundary between the gentle slope portion 87 and the steep slope portion 88 defines a straight line extending top line 82 and valley line 83. The illuminated object is installed below the bottom surface 86 of the light guide plate 81, and an observer observes an image of the illuminated object through the light guide plate 81 from above the upper surface of the light guide plate 81.
【０００５】導光板８１の端面８５から入射した光線８
４ｂは、急な斜面部８８で全反射され、底面８６を透過
して被照明物体を照明する。照明光となる光線８４ｂは
急な斜面部８８で全反射されることにより偏向されるた
め、急な斜面８８が底面８６となす角度の設定が光効率
や反射後の光線の角度に影響を与える。この導光板８１
では、谷線８３を結んだ仮想面Ｐに対する急な斜面部８
８の角度がほぼ導光板媒質の臨界角に設定されており、
これにより、被照明物体にほぼ垂直な方向を光分布の中
心に持つ照明光を実現している。Light rays 8 incident from the end surface 85 of the light guide plate 81
4b is totally reflected by the steep slope portion 88, passes through the bottom surface 86, and illuminates the illuminated object. Since the light ray 84b serving as the illumination light is deflected by being totally reflected by the steep slope portion 88, the setting of the angle formed by the steep slope 88 and the bottom surface 86 affects the light efficiency and the angle of the reflected light ray. . This light guide plate 81
Then, the steep slope 8 with respect to the virtual plane P connecting the valley lines 83
The angle of 8 is set to the critical angle of the light guide plate medium,
As a result, illumination light having a direction substantially perpendicular to the illuminated object at the center of the light distribution is realized.
【０００６】[0006]
【発明が解決しようとする課題】しかし、この導光板８
１は、仮想面Ｐに対する急な斜面部８８の傾きがほぼ導
光板媒質の臨界角に設定されているため、導光板８１を
伝搬する光のうち、底面８６への入射角が比較的小さい
光線８４ａは、斜面部８８で全反射されることなく観察
者側へ透過してしまう。この光は被照明物体を照らすこ
となく観察者側に射出する不要光であり、被照明物体か
ら反射してくる観察像のコントラストを低減させるとと
もに、観察者にとって被照明物体像の観察の妨げとなる
不所望な光として観察者に観察される。However, this light guide plate 8
In No. 1, since the steep slope portion 88 is inclined with respect to the virtual plane P substantially at the critical angle of the light guide plate medium, among the light propagating through the light guide plate 81, the light beam having a relatively small incident angle to the bottom surface 86. 84a is transmitted to the observer side without being totally reflected by the inclined surface portion 88. This light is unnecessary light that is emitted to the observer side without illuminating the illuminated object, reduces the contrast of the observed image reflected from the illuminated object, and prevents the observer from observing the illuminated object image. The undesired light is observed by the observer.
【０００７】本発明の目的は、観察者側に直接透過する
不要光が減少されたフロントライト照明装置を提供する
ことである。It is an object of the present invention to provide a front light illuminating device in which unnecessary light directly transmitted to an observer side is reduced.
【０００８】[0008]
【課題を解決するための手段】本発明の照明装置は、光
を射出するための光源と、前記光源からの光を内部に取
り込みこれを被照明物体に照射するための導光板とを備
えており、前記導光板は、前記光源からの光線を被照明
物体に向けて偏向するための複数の反射面と、前記反射
面に臨界角より小さい入射角で入射し前記反射面を透過
した光線を少なくとも屈折作用により導光板へ戻す凸部
とを有している。An illumination device according to the present invention comprises a light source for emitting light and a light guide plate for taking in the light from the light source into the interior and irradiating the illuminated object with the light. The light guide plate has a plurality of reflecting surfaces for deflecting the light beam from the light source toward the object to be illuminated, and a light beam that is incident on the reflecting surface at an incident angle smaller than a critical angle and is transmitted through the reflecting surface. It has at least a convex portion that returns to the light guide plate by a refraction action.
【０００９】また、本発明の別の照明装置は、光を射出
するための光源と、光源からの光を内部に取り込みこれ
を被照明物体に照射するための導光板とを備えており、
前記導光板は互いに離れて存在する複数の凹凸部を有し
ており、前記凹凸部は、回転対称な形状の凹部と、これ
に取り囲まれている回転対称な形状の凸部とを含んでお
り、前記凹部の外側斜面は光源からの光線を被照明物体
に向けて偏向するための反射面として機能し、前記凸部
は、前記凹部の外側斜面を透過した光線を少なくとも屈
折作用により導光板に戻す働きをする。Another illumination device of the present invention comprises a light source for emitting light and a light guide plate for taking in the light from the light source into the interior and irradiating the illuminated object with the light.
The light guide plate has a plurality of concave-convex portions that are present apart from each other, and the concave-convex portions include a rotationally symmetrical concave portion and a rotationally symmetrical convex portion surrounded by the concave portion. , The outer slope of the concave portion functions as a reflecting surface for deflecting the light beam from the light source toward the illuminated object, and the convex portion at least guides the light ray transmitted through the outer slope of the concave portion to the light guide plate by refraction. It works to return.
【００１０】[0010]
【発明の実施の形態】以下、図面を参照しながら本発明
の実施の形態について説明する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.
【００１１】第一実施形態
本発明の第一実施形態の照明装置について図１〜図４を
参照して説明する。First Embodiment An illumination device according to a first embodiment of the present invention will be described with reference to FIGS.
【００１２】図１〜図２に示されるように、本実施形態
の照明装置は、光を射出するための光源１１と、光源１
１からの光を内部に取り込みこれを被照明物体に照射す
るための導光板１２とを有している。導光板１２は例え
ばアクリル等の樹脂で作製されている。As shown in FIGS. 1 and 2, the illumination device of this embodiment has a light source 11 for emitting light and a light source 1.
The light guide plate 12 for taking in the light from the inside and irradiating it to the illuminated object. The light guide plate 12 is made of a resin such as acrylic.
【００１３】導光板１２は、光源１１の近くに位置する
近位端面１７と、その反対側に位置する遠位端面１８
と、被照明物体に向き合って配置される底面１６と、底
面１６の反対側に位置する上面１９とを有している。導
光板１２は、上面１９に対して設けられた、複数の凹部
１３と凸部１４の組を有しており、凹部１３と凸部１４
は互いに平行に直線的に延びている。各組の凹部１３と
凸部１４は隣接しており、凹部１３は凸部１４よりも光
源の近くに位置している。The light guide plate 12 includes a proximal end surface 17 located near the light source 11 and a distal end surface 18 located on the opposite side.
And a bottom surface 16 arranged to face the illuminated object and a top surface 19 located on the opposite side of the bottom surface 16. The light guide plate 12 has a set of a plurality of concave portions 13 and convex portions 14 provided on the upper surface 19, and the concave portions 13 and the convex portions 14 are provided.
Extend linearly parallel to each other. The concave portion 13 and the convex portion 14 of each set are adjacent to each other, and the concave portion 13 is located closer to the light source than the convex portion 14.
【００１４】図４に詳しく示されるように、凹部１３と
凸部１４は共に三角形の断面形状を有している。すなわ
ち、凹部１３と凸部１４はいずれも二つの平面によって
規定されている。さらに、光源に近い側の凹部１３の平
面と光源から遠い側の凸部１４の平面は共通の平面を構
成している。As shown in detail in FIG. 4, both the concave portion 13 and the convex portion 14 have a triangular sectional shape. That is, the concave portion 13 and the convex portion 14 are both defined by the two planes. Further, the plane of the concave portion 13 on the side closer to the light source and the plane of the convex portion 14 on the side far from the light source form a common plane.
【００１５】後述するように、光源１１に近い側の凹部
１３の斜面すなわち凹部１３の近位斜面は、臨界角より
も大きい入射角で入射する光線を被照明物体に向けて偏
向するための反射面として機能する。また、凸部１４
は、凹部１３の近位斜面に臨界角未満の入射角で入射し
ためにこれを透過した光線を少なくとも屈折作用により
導光板１２へ戻す働きをする。As will be described later, the slope of the recess 13 on the side closer to the light source 11, that is, the proximal slope of the recess 13, is a reflection for deflecting a light beam incident at an incident angle larger than the critical angle toward the illuminated object. Functions as a surface. In addition, the convex portion 14
Has a function of returning to the light guide plate 12 at least by a refraction action, a light beam which has been incident on the proximal inclined surface of the concave portion 13 at an incident angle less than the critical angle and has transmitted therethrough.
【００１６】別の言い方をすれば、導光板１２は、光源
１１からの光線を被照明物体に向けて偏向するための複
数の反射面と、光源１１から遠い側の反射面の遠位端を
一つの頂点とするほぼ三角形形状の複数の凸部１４とを
有している。In other words, the light guide plate 12 has a plurality of reflecting surfaces for deflecting the light rays from the light source 11 toward the object to be illuminated and a distal end of the reflecting surface on the side far from the light source 11. It has a plurality of convex portions 14 each having a substantially triangular shape and forming one vertex.
【００１７】本実施形態の照明装置によって照明される
被照明物体２１は、例えばＬＣＤ等の画像表示装置であ
り、これは、図３に示されるように、導光板１２の底面
１６に向き合って配置される。The illuminated object 21 illuminated by the illumination device of this embodiment is, for example, an image display device such as an LCD, which is arranged facing the bottom surface 16 of the light guide plate 12 as shown in FIG. To be done.
【００１８】光源１１から射出された光は、端面１７を
通って導光板１２に入り、導光板１２の内部を全反射し
ながら伝搬する。それらの光の内、光源１１から近い側
の凹部１３の斜面すなわち凹部１３の近位斜面に臨界角
よりも大きい入射角で入射する光線は、そこで全反射さ
れた後、底面１６を透過して被照明物体２１を照明す
る。The light emitted from the light source 11 enters the light guide plate 12 through the end face 17, and propagates while being totally reflected inside the light guide plate 12. Among these lights, a light ray that is incident on the slope of the recess 13 on the side closer to the light source 11, that is, the proximal slope of the recess 13 at an incident angle larger than the critical angle is totally reflected there and then passes through the bottom surface 16. The illuminated object 21 is illuminated.
【００１９】一方、凹部１３の近位斜面に、臨界角より
も小さい入射角で入射する光線は、そこを透過していっ
たん導光板１２の外へ出た後、凸部１４によって、再び
導光板１２に戻される。導光板１２に戻った光線は、そ
の後、底面１６を透過して被照明物体２１を照明する。On the other hand, a light ray which is incident on the proximal inclined surface of the concave portion 13 at an incident angle smaller than the critical angle passes through the light ray and exits the light guide plate 12 once. Returned to 12. The light rays returning to the light guide plate 12 then pass through the bottom surface 16 and illuminate the illuminated object 21.
【００２０】次に、凹部１３と凸部１４における光線の
振る舞いについて図１５を参照して詳しく説明する。図
１５において、光線１５ａは臨界角よりも大きい入射角
で入射する光線であり、光線１５ｂは臨界角よりは小さ
いが比較的大きい入射角で入射する光線であり、光線１
５ｃは臨界角に比べて相当に小さい入射角で入射する光
線である。Next, the behavior of light rays in the concave portion 13 and the convex portion 14 will be described in detail with reference to FIG. In FIG. 15, the light ray 15a is a light ray incident at an incident angle larger than the critical angle, and the light ray 15b is a light ray incident at a relatively large incident angle smaller than the critical angle.
Reference numeral 5c is a light ray that is incident at an incident angle that is considerably smaller than the critical angle.
【００２１】図１５に示されるように、光源１１に近い
側の凹部１３の斜面すなわち凹部１３の近位斜面に臨界
角よりも大きい入射角で入射する光線１５ａは、そこで
全反射される。つまり、凹部１３の近位斜面は、臨界角
よりも大きい入射角で入射する光線を被照明物体に向け
て偏向するための反射面として機能する。As shown in FIG. 15, a light ray 15a which is incident on the slope of the recess 13 on the side closer to the light source 11, that is, on the proximal slope of the recess 13 at an incident angle larger than the critical angle is totally reflected there. That is, the proximal inclined surface of the concave portion 13 functions as a reflecting surface for deflecting a light ray incident at an incident angle larger than the critical angle toward the illuminated object.
【００２２】臨界角よりは小さいが比較的大きい入射角
で入射する光線１５ｂは、凹部１３の近位斜面を透過す
る。光線１５ｂは、その後、光源１１に近い側の凸部１
４の斜面すなわち近位斜面に入射し、そこで屈折され、
続いて、光源１１に遠い側の凸部１４の斜面すなわち遠
位斜面で反射される。A light ray 15b which is smaller than the critical angle but is incident at a relatively large incident angle passes through the proximal slope of the recess 13. The light beam 15b is then projected on the convex portion 1 on the side closer to the light source 11.
4 is incident on the slope or proximal slope and is refracted there,
Then, the light is reflected by the slope of the convex portion 14 on the side far from the light source 11, that is, the distal slope.
【００２３】臨界角に比べて相当に小さい入射角で入射
する光線１５ｃは、凹部１３の近位斜面を透過する。光
線１５ｃは、その後、凸部１４の近位斜面に入射しそこ
で屈折され、続いて凸部１４の遠位斜面に入射し、そこ
で屈折され、凸部１４を出る。その後、光線１５ｃは、
凸部１４の後方の平面部に入射し、再び導光板１２に戻
る。A light ray 15c incident at an incident angle considerably smaller than the critical angle passes through the proximal slope of the recess 13. Light ray 15c then enters and is refracted at the proximal slope of protrusion 14 and subsequently enters the distal slope of protrusion 14 where it is refracted and exits protrusion 14. After that, the ray 15c is
The light enters the flat surface portion behind the convex portion 14 and returns to the light guide plate 12 again.
【００２４】つまり、凸部１４は、凹部１３の近位斜面
に臨界角未満の入射角で入射しためにこれを透過した光
線を、屈折作用により或いは屈折作用と反射作用によ
り、再び導光板へ戻す働きをする。That is, the convex portion 14 re-enters the light beam, which is transmitted through the light beam, which is incident on the proximal slope of the concave portion 13 at an incident angle less than the critical angle, by refraction or refraction and reflection to the light guide plate again. It works to return.
【００２５】凹部１３の近位斜面（反射面）で全反射さ
れた光線１５ａと、そこを透過した後に凸部１４によっ
て再び導光板１２に戻された光線１５ｂと光線１５ｃ
は、いずれも、その後、底面１６を透過して被照明物体
２１を照明する。A light ray 15a totally reflected by the proximal slope (reflecting surface) of the concave portion 13, and a light ray 15b and a light ray 15c which are transmitted therethrough and then returned to the light guide plate 12 by the convex portion 14 again.
After that, each of them illuminates the illuminated object 21 through the bottom surface 16.
【００２６】凹部１３の近位斜面（反射面）を透過した
光線１５ｂと光線１５ｃは、凸部１４を持たない従来の
導光板においては、そのまま外に放射されてしまう。し
かし、凸部１４を備えている本実施形態の導光板１２に
おいては、このような光線１５ｂと光線１５ｃは、再び
導光板１２に戻されて、被照明物体２１の照明に利用さ
れる。The light rays 15b and 15c transmitted through the proximal slope (reflection surface) of the concave portion 13 are radiated to the outside as they are in the conventional light guide plate having no convex portion 14. However, in the light guide plate 12 of the present embodiment including the convex portion 14, such light rays 15b and 15c are returned to the light guide plate 12 again and used for illuminating the illuminated object 21.
【００２７】凹部１３の近位斜面の傾斜角αは例えば４
５°程度、凸部１４の近位斜面の傾斜角βは例えば７５
度程度、凸部１４の遠位斜面の傾斜角εは例えば４５°
程度に設定される。傾斜角αの最適値は、光源１１の光
量分布、導光板１２の長さや屈折率などの条件に依存し
て変わる。一般には、傾斜角αは、被照明物体への照射
光がなるべく垂直に入射するように最適化される。ま
た、凸部１４の遠位斜面の傾斜角εは、凹部１３の近位
斜面を透過した光線のうちより多くの光線が全反射され
るように設定される。The inclination angle α of the proximal slope of the recess 13 is, for example, 4
The inclination angle β of the proximal slope of the convex portion 14 is about 5 °, for example, 75
Degree, the inclination angle ε of the distal slope of the convex portion 14 is, for example, 45 °.
It is set to a degree. The optimum value of the inclination angle α changes depending on conditions such as the light amount distribution of the light source 11, the length of the light guide plate 12 and the refractive index. In general, the inclination angle α is optimized so that the irradiation light to the illuminated object enters as vertically as possible. Further, the inclination angle ε of the distal slope of the convex portion 14 is set so that a larger number of light rays transmitted through the proximal slope of the concave portion 13 are totally reflected.
【００２８】凸部１４の近位斜面が凹部１３に近いほ
ど、言い換えれば傾斜角βが大きいほど、凹部１３の近
位斜面すなわち反射面を透過した光は凸部１４に入射し
易く、不要光低減の効果が上がる。また、傾斜角βを大
きくする代わりに、凸部１４を高くしても、不要光が凸
部１４に入射し易くなり、不要光低減の効果が上がる。
どちらの手法を採用するかは、導光板の作製方法などに
応じて作製上有利な方を選択すればよい。As the proximal slope of the protrusion 14 is closer to the recess 13, in other words, the larger the inclination angle β is, the light transmitted through the proximal slope of the recess 13, that is, the reflecting surface is more likely to be incident on the protrusion 14, and unnecessary light. The effect of reduction increases. Further, even if the convex portion 14 is raised instead of increasing the inclination angle β, unnecessary light easily enters the convex portion 14, and the effect of reducing unnecessary light is improved.
Which method is adopted may be selected according to the manufacturing method of the light guide plate and the like, which is advantageous in manufacturing.
【００２９】このように本実施形態の照明装置では、凹
部１３の近位斜面を透過した光が、凸部１４によって再
び導光板１２に戻され、被照明物体を照明するので、観
察者２２は、導光板１２を通して、被照明物体２１の明
るい画像を見ることができる。As described above, in the illumination device of the present embodiment, the light transmitted through the proximal slope of the concave portion 13 is returned to the light guide plate 12 by the convex portion 14 and illuminates the illuminated object. A bright image of the illuminated object 21 can be seen through the light guide plate 12.
【００３０】第二実施形態
本発明の第二実施形態の照明装置について図５を参照し
て説明する。本実施形態の照明装置は、第一実施形態の
照明装置と比較して、光源のみが異なっており、それ以
外の構成は同じである。Second Embodiment A lighting device according to a second embodiment of the present invention will be described with reference to FIG. The lighting device of the present embodiment is different from the lighting device of the first embodiment only in the light source, and the other configurations are the same.
【００３１】図５に示されるように、本実施形態の照明
装置では、光源３１は直線的に並んだ複数のＬＥＤを備
えている。発光素子にＬＥＤを用いることによって、第
一実施形態の利点に加えて、小型化され、耐振性が向上
し、落下耐性が向上し、光源駆動回路が簡素化される。As shown in FIG. 5, in the lighting device of this embodiment, the light source 31 is provided with a plurality of linearly arranged LEDs. By using the LED as the light emitting element, in addition to the advantages of the first embodiment, the size is reduced, the vibration resistance is improved, the drop resistance is improved, and the light source drive circuit is simplified.
【００３２】光源３１は点光源群であり、このために照
度ムラなどの問題が発生する場合には、導光板１２の近
位端面に拡散板などが配置されるとよい。The light source 31 is a point light source group, and if problems such as uneven illuminance occur due to this, a diffuser plate or the like may be arranged on the proximal end face of the light guide plate 12.
【００３３】第三実施形態
本発明の第三実施形態の照明装置について図６を参照し
て説明する。本実施形態の照明装置は、凹部１３の深さ
と凸部１４の高さに特徴があり、その基本的な構成は第
一実施形態の照明装置と同じである。Third Embodiment An illumination device according to the third embodiment of the present invention will be described with reference to FIG. The lighting device of the present embodiment is characterized by the depth of the concave portion 13 and the height of the convex portion 14, and its basic configuration is the same as that of the lighting device of the first embodiment.
【００３４】図６に示されるように、導光板１２はその
上面に複数組の凹部１３と凸部１４を備えている。任意
の二組の凹部１３と凸部１４において、光源に近い方の
組の凹部１３の深さをｈ１、凸部１４の高さをｄ１と
し、一方、光源から遠い方の組の凹部１３の深さをｈ
２、凸部１４の高さをｄ２としたとき、任意の二組の凹
部１３と凸部１４は常にｄ１／ｈ１＜ｄ２／ｈ２・・・
（１）を満足している。As shown in FIG. 6, the light guide plate 12 has a plurality of sets of concave portions 13 and convex portions 14 on its upper surface. In any two arbitrary sets of the concave portion 13 and the convex portion 14, the depth of the concave portion 13 of the pair closer to the light source is h1, and the height of the convex portion 14 is d1, while the concave portion 13 of the pair farther from the light source is Depth to h
2, when the height of the convex portion 14 is d2, the arbitrary two sets of concave portion 13 and convex portion 14 are always d1 / h1 <d2 / h2 ...
Satisfies (1).
【００３５】別の言い方をすれば、凹部１３の深さ（反
射面の深さ）をｈ、凸部１４の高さをｄとしたとき、ｈ
／ｄが光源１１から離れるに従って小さくなっていく。In other words, when the depth of the concave portion 13 (the depth of the reflecting surface) is h and the height of the convex portion 14 is d, h
/ D becomes smaller as the distance from the light source 11 increases.
【００３６】第一実施形態で説明したように、光源１１
から導光板１２に入射した光は導光板の中を全反射しな
がら伝搬する。従って、底面に対する角度が大きい光
線、言い換えれば底面に対する入射角が小さい光線は、
数多く全反射を繰り返して伝搬する。一方、底面に対す
る角度が小さい光線、言い換えれば底面に対する入射角
が大きい光線は、あまり全反射を繰り返すことなく伝搬
する。As described in the first embodiment, the light source 11
The light that has entered the light guide plate 12 from is propagated while being totally reflected in the light guide plate. Therefore, a light ray with a large angle to the bottom surface, in other words, a light ray with a small incident angle to the bottom surface,
Propagate by repeating total reflection many times. On the other hand, a light ray having a small angle to the bottom surface, in other words, a light ray having a large incident angle to the bottom surface propagates without repeating total reflection.
【００３７】底面に対する角度が大きい光線は、全反射
を数多く繰り返すため、導光板１２の凹部１３の近位斜
面に入射する確率が高く、導光板１２の光源１１から近
い部位において凹部１３や凸部１４によって偏向される
確率が高い。一方、底面に対する角度が小さい光線は、
上面と底面に当たる回数が少ないので、凹部１３の近位
斜面に入射する確率が少なく、導光板１２の中を遠くま
で伝搬していく確率が高い。Since a light ray having a large angle with respect to the bottom surface is repeatedly totally reflected, there is a high probability that it will be incident on the proximal slope of the concave portion 13 of the light guide plate 12, and the concave portion 13 or the convex portion will be near the light source 11 of the light guide plate 12. The probability of being biased by 14 is high. On the other hand, a ray with a small angle to the bottom is
Since the number of times of contact with the top surface and the bottom surface is small, the probability of incidence on the proximal slope of the recess 13 is low, and the probability of propagating far into the light guide plate 12 is high.
【００３８】このため、一般的には、導光板１２の底面
となす角が大きい光線すなわち図４に示される光線１５
ｃは、光源１１から離れるに従って少なくなる。従っ
て、光源１１から遠い位置にある凸部１４は、その高さ
が、光源１１から近い位置にある凸部１４よりも低くて
よい。Therefore, in general, a light ray having a large angle with the bottom surface of the light guide plate 12, that is, the light ray 15 shown in FIG.
c decreases with increasing distance from the light source 11. Therefore, the height of the convex portion 14 located far from the light source 11 may be lower than that of the convex portion 14 located closer to the light source 11.
【００３９】また、導光板１２を伝搬する光の絶対量は
光源１１から離れるに従って減少するので、被照明物体
への照度をなるべく一定にするためには、光源１１から
遠い部位では、光線を反射するための反射面すなわち凹
部１３の近位斜面が大きいとよい。言い換えれば、光源
１１から遠い位置にある凹部１３は、その深さが光源１
１から近い位置にある凹部１３よりも大きいとよい。Further, the absolute amount of light propagating through the light guide plate 12 decreases as the distance from the light source 11 increases. Therefore, in order to keep the illuminance on the illuminated object as constant as possible, the light rays are reflected at the part far from the light source 11. It is preferable that the reflecting surface for doing so, that is, the proximal slope of the recess 13 is large. In other words, the depth of the recess 13 located far from the light source 11 is smaller than that of the light source 1.
It is preferable that it is larger than the concave portion 13 located at a position closer to 1.
【００４０】凹部１３の近位斜面の傾斜角αと凸部１４
の近位斜面の傾斜角βを一定に保ったままで凹部１３を
深くすると、図４から容易に想像できるように、凹部１
３の近位端部と凸部１４との距離が離れる。このため、
凹部１３の近位斜面を透過した不要光の多くが凸部１４
に入射するためには、凹部１３の深さの増加に応じて、
凸部１４の高さも増加させた方がよいと考えられる。The inclination angle α of the proximal slope of the concave portion 13 and the convex portion 14
If the concave portion 13 is deepened while keeping the inclination angle β of the proximal slope of the concave portion 1 constant, as shown in FIG.
The distance between the proximal end of 3 and the convex portion 14 is increased. For this reason,
Most of unnecessary light transmitted through the proximal slope of the concave portion 13 is the convex portion 14
In order to be incident on the
It is considered that the height of the convex portion 14 should be increased.
【００４１】しかし、上述のように導光板１２の光量分
布から考えると、凸部１４の高さは、凹部１３の深さの
増加に従って単純増加させる必要はなく、凹部１３の深
さの増加に比べて少ない高さ増加であっても不要光を低
減し得る。However, considering the light quantity distribution of the light guide plate 12 as described above, it is not necessary to simply increase the height of the convex portion 14 as the depth of the concave portion 13 increases. Unnecessary light can be reduced even with a small increase in height.
【００４２】これらを考慮して得られた条件が前述の
（１）式であり、任意の二組の凹部１３と凸部１４は常
にｄ１／ｈ１＜ｄ２／ｈ２の関係を満たしている。The condition obtained in consideration of these is the above-mentioned expression (1), and the arbitrary two sets of the concave portion 13 and the convex portion 14 always satisfy the relationship of d1 / h1 <d2 / h2.
【００４３】本実施形態によれば、（１）式の条件を満
たすように導光板１２を構成することにより、第一実施
形態の利点に加えて、凸部１４の高さが不要に高くなる
ことを抑制でき、凹部１３と凸部１４の段差を小さくで
きる。このような段差の少ない導光板１２は加工性の面
で好適である。According to this embodiment, by configuring the light guide plate 12 so as to satisfy the condition of the expression (1), in addition to the advantages of the first embodiment, the height of the convex portion 14 becomes unnecessarily high. This can be suppressed, and the step difference between the concave portion 13 and the convex portion 14 can be reduced. The light guide plate 12 having such a small step is suitable in terms of workability.
【００４４】第四実施形態
本発明の第四実施形態の照明装置について図７を参照し
て説明する。本実施形態の照明装置は、導光板１２の上
面の凹部１３と凸部１４の間の平面部に特徴があり、そ
の基本的な構成は第一実施形態の照明装置と同じであ
る。Fourth Embodiment An illumination device according to the fourth embodiment of the present invention will be described with reference to FIG. The lighting device of the present embodiment is characterized by a flat surface portion between the concave portion 13 and the convex portion 14 on the upper surface of the light guide plate 12, and its basic configuration is the same as that of the lighting device of the first embodiment.
【００４５】図７に示されるように、導光板１２の上面
は、凹部１３と凸部１４の間に平面部５１を有してい
る。より詳しくは、導光板１２の端面１７とそこから最
も近い凹部１３との間、導光板１２の遠位端面１８とそ
こから最も近い凸部１４との間、それぞれ隣りの組に含
まれる凹部１３と凸部１４との間に、複数の平面部５１
を有している。平面部５１は底面１６に対して傾きγを
有しており、平面部５１は、光源１１から離れるに従っ
て導光板１２の厚さを増加させるように傾いている。平
面部５１の傾きは一定となっている。As shown in FIG. 7, the upper surface of the light guide plate 12 has a flat portion 51 between the concave portion 13 and the convex portion 14. More specifically, between the end face 17 of the light guide plate 12 and the recess 13 closest thereto, between the distal end face 18 of the light guide plate 12 and the protrusion 14 closest thereto, the recesses 13 included in the adjacent groups, respectively. And a plurality of flat portions 51 between the convex portion 14 and the convex portion 14.
have. The plane portion 51 has an inclination γ with respect to the bottom surface 16, and the plane portion 51 is inclined so as to increase the thickness of the light guide plate 12 as the distance from the light source 11 increases. The inclination of the flat portion 51 is constant.
【００４６】別の言い方をすれば、複数の反射面（凹部
１３の近位斜面）の近位端の高さと、複数の凸部１４の
遠位斜面の遠位端の高さとが異なっており、従って、そ
れらの間に位置する平面部５１は底面１６に対して傾き
γを有している。より詳しくは、複数の反射面（凹部１
３の近位斜面）の近位端の高さは複数の凸部１４の遠位
斜面の遠位端の高さよりも大きく、従って、平面部５１
は、光源１１から離れるに従って導光板１２の厚さを増
加させるように傾いている。In other words, the heights of the proximal ends of the plurality of reflecting surfaces (the proximal slopes of the recesses 13) and the heights of the distal ends of the distal slopes of the plurality of projections 14 are different. Therefore, the plane portion 51 located between them has the inclination γ with respect to the bottom surface 16. More specifically, a plurality of reflecting surfaces (recesses 1
3 is greater than the height of the distal end of the distal bevel of the plurality of protrusions 14, and thus the flat portion 51.
Are inclined so that the thickness of the light guide plate 12 increases as the distance from the light source 11 increases.
【００４７】導光板内を伝搬する光線は、底面１６に対
して傾いた平面部５１で反射されながら伝搬していくの
で、底面１６に対する光線の傾きは、光源１１から離れ
るに従って次第に減少していく。図４を参照した先の説
明から分かるように、底面１６に対する傾きが小さい光
線１５ａは照明光として好適である。従って、このよう
な導光板１２においては、光源１１から離れた位置にお
いても、照明に有効な光線を多く得られる。The light ray propagating in the light guide plate propagates while being reflected by the flat portion 51 inclined with respect to the bottom surface 16, so that the inclination of the light ray with respect to the bottom surface 16 gradually decreases as the distance from the light source 11 increases. . As can be seen from the above description with reference to FIG. 4, the light ray 15a having a small inclination with respect to the bottom surface 16 is suitable as illumination light. Therefore, in such a light guide plate 12, many light rays effective for illumination can be obtained even at a position away from the light source 11.
【００４８】本実施形態によれば、第一実施形態の利点
に加えて、導光板１２の光源１１から遠い位置において
も、照明に有効な多くの光線を得ることができるため、
光源から離れた位置での照度を確保し易い。また、導光
板１２は、平面部５１の傾きが一定なので、比較的容易
に作製され得る。According to this embodiment, in addition to the advantages of the first embodiment, many light rays effective for illumination can be obtained even at a position far from the light source 11 of the light guide plate 12.
It is easy to secure the illuminance at the position away from the light source. Further, the light guide plate 12 can be manufactured relatively easily because the flat portion 51 has a constant inclination.
【００４９】第五実施形態
本発明の第四実施形態の照明装置について図８を参照し
て説明する。本実施形態の照明装置は、導光板１２の上
面の凹部１３と凸部１４の間の平面部に特徴があり、そ
の基本的な構成は第一実施形態の照明装置と同じであ
る。Fifth Embodiment An illumination device according to the fourth embodiment of the present invention will be described with reference to FIG. The lighting device of the present embodiment is characterized by a flat surface portion between the concave portion 13 and the convex portion 14 on the upper surface of the light guide plate 12, and its basic configuration is the same as that of the lighting device of the first embodiment.
【００５０】図８に示されるように、導光板１２の上面
は、凹部１３と凸部１４の間に平面部６１を有してい
る。より詳しくは、導光板１２の端面１７とそこから最
も近い凹部１３との間、導光板１２の遠位端面１８とそ
こから最も近い凸部１４との間、それぞれ隣りの組に含
まれる凹部１３と凸部１４との間に、複数の平面部６１
を有している。As shown in FIG. 8, the upper surface of the light guide plate 12 has a flat portion 61 between the concave portion 13 and the convex portion 14. More specifically, between the end face 17 of the light guide plate 12 and the recess 13 closest thereto, between the distal end face 18 of the light guide plate 12 and the protrusion 14 closest thereto, the recesses 13 included in the adjacent groups, respectively. And a plurality of plane portions 61 between the convex portion 14 and the convex portion 14.
have.
【００５１】平面部６１は、底面１６に対して、導光板
の部位により異なる傾きを有している。平面部６１は、
光源１１から比較的近い部位においては、光源１１から
離れるに従って導光板１２の厚さが増加するような傾き
φ1を有しており、また、光源１１から比較的遠い部位
においては、光源１１から離れるに従って導光板１２の
厚さが減少するような傾きφ2を有している。The plane portion 61 has a different inclination with respect to the bottom surface 16 depending on the portion of the light guide plate. The flat portion 61 is
The portion relatively close to the light source 11 has an inclination φ1 such that the thickness of the light guide plate 12 increases as the distance from the light source 11 increases, and the portion relatively far from the light source 11 moves away from the light source 11. Accordingly, the light guide plate 12 has an inclination φ2 such that the thickness thereof decreases.
【００５２】第四実施形態において説明したように、導
光板１２の平面部６１が光源１１から離れるに従って導
光板１２の厚さが増加するような傾きφ1を有している
と、導光板１２の光源１１から遠い部位において、底面
１６に対する角度が小さい光線を多く得られる。その反
面、特に導光板１２が非常に長い場合等には、その作用
が効き過ぎて、光源１１から遠い部位では、底面１６に
ほぼ平行な光線が多くなり過ぎて、凹部１３に光線が入
射し難くなる。As described in the fourth embodiment, when the flat surface portion 61 of the light guide plate 12 has the inclination φ1 such that the thickness of the light guide plate 12 increases as the distance from the light source 11 increases, In a region far from the light source 11, many light rays having a small angle with respect to the bottom surface 16 can be obtained. On the other hand, especially when the light guide plate 12 is very long, the effect is too effective, and in a portion far from the light source 11, the number of light rays substantially parallel to the bottom surface 16 becomes too large and the light rays enter the concave portion 13. It will be difficult.
【００５３】本実施形態では、導光板１２の平面部６１
は、光源１１から比較的遠い部位においては、光源１１
から離れるに従って導光板１２の厚さが減少するような
傾きφ2を有している。このような平面部６１の傾きφ2
は、傾きφ1とは逆に、底面１６に対する角度が大きい
光線を作り出す。従って、特に非常に長い導光板１２に
おいて光源１１から遠い部位で起こりがちな凹部１３の
近位斜面に入射する光線の不足が補われる。In this embodiment, the flat surface portion 61 of the light guide plate 12 is used.
Is a light source 11 in a region relatively far from the light source 11.
The inclination φ2 is such that the thickness of the light guide plate 12 decreases with increasing distance from. The inclination φ2 of the flat portion 61
Produces a light ray having a large angle with respect to the bottom surface 16, contrary to the inclination φ1. Therefore, the shortage of light rays incident on the proximal slope of the concave portion 13 which tends to occur at a portion far from the light source 11 in the light guide plate 12 which is very long is compensated.
【００５４】本実施形態によれば、導光板１２の上面の
平面部６１の傾きをその位置に依存して変えて、導光板
１２を伝搬する光線の平面部６１に対する角度を制御す
ることにより、照明光が好適な分布で被照明物体に照射
される照明装置が得られる。According to this embodiment, the inclination of the flat surface portion 61 of the upper surface of the light guide plate 12 is changed depending on its position to control the angle of the light beam propagating through the light guide plate 12 with respect to the flat surface portion 61. It is possible to obtain an illumination device in which illumination light is applied to an illuminated object with a suitable distribution.
【００５５】第六実施形態
本発明の第六実施形態の照明装置について図９を参照し
て説明する。図９に示されるように、本実施形態の照明
装置は、光を射出するための一対の光源１１ａ，１１ｂ
と、光源１１ａ，１１ｂからの光を内部に取り込みこれ
を被照明物体に照射するための導光板７１とを有してい
る。Sixth Embodiment An illumination device according to a sixth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 9, the illumination device according to the present embodiment includes a pair of light sources 11a and 11b for emitting light.
And a light guide plate 71 for taking in light from the light sources 11a and 11b into the interior and irradiating the illuminated object with the light.
【００５６】導光板７１は、一対の向かい合った端面７
５，７６を有しており、これらの端面７５，７６の近く
に光源１１ａ，１１ｂがそれぞれ配置される。導光板７
１は、さらに、被照明物体に向き合って配置される底面
７７と、底面７７の反対側に位置する上面とを有してい
る。導光板７１は、複数の凹部７２と凸部７３と凹部７
４の組を有しており、凹部７２と凸部７３と凹部７４は
互いに平行に直線的に延びている。各組の凹部７２と凸
部７３と凹部７４は隣接しており、凹部７２と凹部７４
は凸部７３の両側に位置している。The light guide plate 71 includes a pair of opposed end faces 7
5 and 76, and the light sources 11a and 11b are arranged near these end faces 75 and 76, respectively. Light guide plate 7
1 further has a bottom surface 77 arranged to face the illuminated object, and an upper surface located on the opposite side of the bottom surface 77. The light guide plate 71 includes a plurality of concave portions 72, convex portions 73, and concave portions 7.
4 sets, and the concave portion 72, the convex portion 73, and the concave portion 74 extend linearly in parallel with each other. The concave portion 72, the convex portion 73, and the concave portion 74 of each set are adjacent to each other, and the concave portion 72 and the concave portion 74 are adjacent to each other.
Are located on both sides of the convex portion 73.
【００５７】凹部７２と凸部７３と凹部７４は共に三角
形の断面形状を有している。すなわち、凹部７２と凸部
７３と凹部７４はいずれも二つの平面によって規定され
ている。さらに、凸部７３を規定する二つの平面はそれ
ぞれ、凹部７２と凹部７４を規定する一方の平面と共通
の平面を構成している。Each of the concave portion 72, the convex portion 73, and the concave portion 74 has a triangular sectional shape. That is, each of the concave portion 72, the convex portion 73, and the concave portion 74 is defined by two planes. Further, each of the two planes defining the convex portion 73 constitutes a common plane with one plane defining the concave portion 72 and the concave portion 74.
【００５８】凹部７２の光源１１ａに近い側の斜面は、
光源１１ａからの光のうち、臨界角よりも大きい入射角
で入射する光線を被照明物体に向けて偏向するための反
射面とし、同様に、凹部７４の光源１１ｂに近い側の斜
面は、光源１１ｂからの光のうち、臨界角よりも大きい
入射角で入射する光線を被照明物体に向けて偏向するた
めの反射面として機能する。The slope of the recess 72 on the side closer to the light source 11a is
Of the light from the light source 11a, it serves as a reflecting surface for deflecting a light ray incident at an incident angle larger than the critical angle toward the object to be illuminated, and similarly, the sloped surface of the recess 74 near the light source 11b is a light source. Of the light from 11b, it functions as a reflecting surface for deflecting a light ray incident at an incident angle larger than the critical angle toward the illuminated object.
【００５９】従って、別の言い方をすれば、導光板７１
には、三角形の断面形状の複数の凸部７３と、その各々
に対して、凸部７３を挟んで相対して二つの反射面（凹
部７２の光源１１ａに近い側の斜面と凹部７４の光源１
１ｂに近い側の斜面）が形成されている。Therefore, in other words, the light guide plate 71
, A plurality of convex portions 73 having a triangular cross-sectional shape, and two reflecting surfaces (a slope of the concave portion 72 on the side closer to the light source 11a and a light source of the concave portion 74) facing each other with the convex portion 73 interposed therebetween. 1
1b) is formed.
【００６０】光源１１ａから射出され導光板７１に入っ
た光線は、凹部７２の光源１１ａ側の斜面で全反射さ
れ、底面７７から射出され、被照明物体に照射される。
一方、光源１１ｂから射出され導光板７１に入った光線
は、凹部７４の光源１１ｂ側の斜面で全反射され、底面
７７から射出され、被照明物体に照射される。また、反
射面として機能する凹部７２または凹部７４の斜面を透
過し凸部７３に入射した光線は、屈折作用によって或い
は屈折作用と反射作用によって、再び導光板７１に戻さ
れる。The light beam emitted from the light source 11a and entering the light guide plate 71 is totally reflected by the inclined surface of the concave portion 72 on the light source 11a side, emitted from the bottom surface 77, and irradiated to the illuminated object.
On the other hand, the light beam emitted from the light source 11b and entering the light guide plate 71 is totally reflected by the slope of the concave portion 74 on the light source 11b side, emitted from the bottom surface 77, and irradiated to the illuminated object. Further, a light ray that has passed through the sloped surface of the concave portion 72 or the concave portion 74 functioning as a reflecting surface and is incident on the convex portion 73 is returned to the light guide plate 71 again by refraction or refraction and reflection.
【００６１】本実施形態によれば、第一実施形態の利点
に加えて、光を射出する二つの光源１１ａ，１１ｂが導
光板７１の向かい合った二つの端面７５ａ，７６の近く
に配置されているので、更に照度の高い照明装置が得ら
れる。According to this embodiment, in addition to the advantages of the first embodiment, the two light sources 11a and 11b for emitting light are arranged near the two end faces 75a and 76 of the light guide plate 71 which face each other. Therefore, a lighting device with higher illuminance can be obtained.
【００６２】本実施形態では、導光板７１の一対の向か
い合った端面７５，７６の近くに一対の光源１１ａ，１
１ｂが配置されているが、その一変形例として、その一
方の光源（例えば光源１１ｂ）を省くと共に、その近く
の端面（例えば端面７６）に反射膜を設けてもよい。こ
の場合、残っている光源（例えば光源１１ａ）から射出
され導光板７１を伝搬してきた光線は、反射膜で反射さ
れて再び導光板内に伝搬するので、上述した本実施形態
とほぼ同様の利点が得られる。In this embodiment, the pair of light sources 11a, 1a is provided near the pair of opposed end faces 75, 76 of the light guide plate 71.
1b is arranged, but as a modification thereof, one of the light sources (for example, the light source 11b) may be omitted, and a reflective film may be provided on the end face (for example, the end face 76) near the one light source. In this case, the light beam emitted from the remaining light source (for example, the light source 11a) and propagating through the light guide plate 71 is reflected by the reflection film and propagates again into the light guide plate, so that there are advantages similar to those of the present embodiment described above. Is obtained.
【００６３】第七実施形態
本発明の第六実施形態の照明装置について図１０〜図１
３を参照して説明する。図１０に示されるように、本実
施形態の照明装置は、光を射出するための四つの光源９
１ａ，９１ｂ，９１ｃ，９１ｄと、これらの光源からの
光を内部に取り込みこれを被照明物体に照射するための
導光板９２とを有している。Seventh Embodiment FIG. 10 to FIG. 1 on an illumination device according to a sixth embodiment of the present invention.
This will be described with reference to FIG. As shown in FIG. 10, the lighting device of the present embodiment has four light sources 9 for emitting light.
1a, 91b, 91c, 91d, and a light guide plate 92 for taking in the light from these light sources inside and irradiating it with the illuminated object.
【００６４】導光板９２は、一対の向かい合った端面９
９ａ，９９ｃと、別の一対の向かい合った端面９９ｂ，
９９ｄとを有しており、これらの端面９９ａ，９９ｂ，
９９ｃ，９９ｄの近くに光源９１ａ，９１ｂ，９１ｃ，
９１ｄがそれぞれ配置されている。導光板９２は、さら
に、被照明物体に向き合って配置される底面９７と、底
面９７の反対側に位置する上面とを有している。導光板
９２は、その上面に互いに離れて存在する複数の凹凸部
９３を有している。The light guide plate 92 has a pair of end faces 9 facing each other.
9a, 99c and another pair of opposite end faces 99b,
99d and these end faces 99a, 99b,
Light sources 91a, 91b, 91c, near 99c, 99d,
91d are arranged respectively. The light guide plate 92 further has a bottom surface 97 that faces the object to be illuminated, and a top surface that is located on the opposite side of the bottom surface 97. The light guide plate 92 has a plurality of concavo-convex portions 93 that are present on the upper surface thereof and are spaced apart from each other.
【００６５】凹凸部９３は、図１１と図１２に詳しく示
されるように、円形の平面部９６と、これを取り囲んで
いる輪帯状の凸部９５と、さらに凸部９５を取り囲んで
いる輪帯状の凹部９４とを有している。凹凸部９３は、
図１１に示される断面を軸Ａを中心に回転して得られる
回転対称な形状を有している。すなわち、凹部９４と凸
部９５はいずれも、円錐の側面の一部から成る二つの曲
面によって規定されている。さらに、凹部９４を規定す
る内側の曲面と凸部９５を規定する外側の曲面とは共通
の一つの曲面を構成している。As shown in detail in FIGS. 11 and 12, the uneven portion 93 has a circular flat surface portion 96, a ring-shaped convex portion 95 surrounding the flat portion 96, and a ring-shaped portion surrounding the convex portion 95. And a concave portion 94. The uneven portion 93 is
It has a rotationally symmetric shape obtained by rotating the cross section shown in FIG. 11 about the axis A. That is, both the concave portion 94 and the convex portion 95 are defined by the two curved surfaces formed by a part of the side surface of the cone. Furthermore, the inner curved surface that defines the concave portion 94 and the outer curved surface that defines the convex portion 95 constitute one common curved surface.
【００６６】つまり、凹凸部９３は、回転対称な形状の
凹部９４と、これに取り囲まれている回転対称な形状の
凸部９５とを含んでおり、後述するように、凹部９４の
外側斜面は光源からの光線を被照明物体に向けて偏向す
るための反射面として機能し、凸部９５は、凹部９４の
外側斜面を透過した光線を少なくとも屈折作用により導
光板に戻す働きをする。That is, the concave-convex portion 93 includes the rotationally symmetrical concave portion 94 and the rotationally symmetrical convex portion 95 surrounded by the concave portion 94. The convex portion 95 functions as a reflecting surface for deflecting the light ray from the light source toward the illuminated object, and the convex portion 95 functions to return the light ray transmitted through the outer slope of the concave portion 94 to the light guide plate by at least the refracting action.
【００６７】図１３に示されるように、例えば光源９１
ａから射出され導光板９２を伝搬する光線９８ａは、輪
帯状の凹部９４の外側斜面で全反射され、底面９７から
射出され、被照明物体を照明する。輪帯状の凹部９４の
外側斜面は、また、光源９１ｃから射出された光線９８
ｂを全反射して、底面９７から射出させ、被照明物体に
照射させる。また、輪帯状の凹部９４の外側斜面を透過
し凸部９５に入射した光線９８ｃは、屈折作用によって
或いは屈折作用と反射作用によって、再び導光板９２に
戻される。As shown in FIG. 13, for example, the light source 91
A light ray 98a emitted from a and propagating through the light guide plate 92 is totally reflected by the outer slope of the annular recess 94, emitted from the bottom surface 97, and illuminates the illuminated object. The outer slope of the ring-shaped recess 94 also has a light ray 98 emitted from the light source 91c.
b is totally reflected, emitted from the bottom surface 97, and illuminated on the illuminated object. Further, the light ray 98c that has passed through the outer slope of the annular recess 94 and entered the convex portion 95 is returned to the light guide plate 92 again by the refraction action or the refraction action and the reflection action.
【００６８】凹部９４と凸部９５は回転対称形状を有し
ているので、上述した凹部９４と凸部９５の働きは光線
の伝搬方向に依存しない。すなわち、任意の方向に伝搬
する光線に対して凹部９４と凸部９５は同様の働きをす
る。つまり、導光板９２の四方に配置された光源９１
ａ，９１ｂ，９１ｃ，９１ｄからの光線を同様に効率良
く底面から射出させる。Since the concave portion 94 and the convex portion 95 have a rotationally symmetrical shape, the functions of the concave portion 94 and the convex portion 95 described above do not depend on the propagation direction of the light beam. That is, the concave portion 94 and the convex portion 95 have the same function with respect to a ray propagating in an arbitrary direction. That is, the light sources 91 arranged on all sides of the light guide plate 92.
Light rays from a, 91b, 91c, and 91d are similarly efficiently emitted from the bottom surface.
【００６９】本実施形態によれば、第一実施形態の利点
に加えて、光を射出するための四つの光源９１ａ，９１
ｂ，９１ｃ，９１ｄが導光板９２の四方の端面９９ａ，
９９ｂ，９９ｃ，９９ｄの近くに配置されているので、
照度の高い照明装置が得られる。According to this embodiment, in addition to the advantages of the first embodiment, four light sources 91a, 91 for emitting light are provided.
b, 91c, 91d are four end surfaces 99a of the light guide plate 92,
Since it is located near 99b, 99c, 99d,
An illumination device with high illuminance can be obtained.
【００７０】本実施形態において、導光板の四つの端面
の各々に対して一つずつ光源が配置されているが、光源
の数は装置全体の制約により増減されてもよい。さら
に、その近くに光源が配置されない端面には反射膜が設
けられるとよい。端面に入射した光線は、そこに反射膜
が設けられていなければ照明に寄与することなく外に放
射されてしまうが、そこに設けられている反射膜で反射
されて、再び導光板内に戻されるので、光源からの射出
光が効率良く照明光に使用される。In the present embodiment, one light source is arranged for each of the four end faces of the light guide plate, but the number of light sources may be increased or decreased depending on the restrictions of the entire device. Further, a reflective film may be provided on the end face where the light source is not arranged near the end face. The light beam incident on the end face is emitted to the outside without contributing to illumination unless a reflection film is provided there, but is reflected by the reflection film provided there and returned to the light guide plate again. Therefore, the light emitted from the light source is efficiently used as the illumination light.
【００７１】これまで、いくつかの実施の形態について
図面を参照しながら具体的に説明したが、本発明は、上
述した実施の形態に限定されるものではなく、その要旨
を逸脱しない範囲で行なわれるすべての実施を含む。Although some embodiments have been concretely described with reference to the drawings, the present invention is not limited to the above-mentioned embodiments and can be carried out without departing from the scope of the invention. Includes all implementations.
【００７２】[0072]
【発明の効果】本発明によれば、導光板が反射面を透過
した光線を導光板へ戻すための凸部を有していることに
より、観察者側に直接透過する不要光が減少されたフロ
ントライト照明装置が提供される。According to the present invention, since the light guide plate has the convex portion for returning the light beam transmitted through the reflection surface to the light guide plate, unnecessary light directly transmitted to the observer side is reduced. A front light illumination device is provided.
【図１】本発明の第一実施形態の照明装置の側断面図で
ある。FIG. 1 is a side sectional view of a lighting device according to a first embodiment of the present invention.
【図２】図１に示される照明装置の斜視図である。2 is a perspective view of the lighting device shown in FIG. 1. FIG.
【図３】導光板の凹部で反射される光の経路を示してい
る。FIG. 3 shows a path of light reflected by a concave portion of a light guide plate.
【図４】図３に示される凹部と凸部を拡大して示してい
る。FIG. 4 is an enlarged view of a concave portion and a convex portion shown in FIG.
【図５】本発明の第二実施形態の照明装置の斜視図であ
る。FIG. 5 is a perspective view of a lighting device according to a second embodiment of the present invention.
【図６】本発明の第三実施形態の照明装置の側断面図で
ある。FIG. 6 is a side sectional view of a lighting device according to a third embodiment of the present invention.
【図７】本発明の第四実施形態の照明装置の側断面図で
ある。FIG. 7 is a side sectional view of a lighting device according to a fourth embodiment of the present invention.
【図８】本発明の第五実施形態の照明装置の側断面図で
ある。FIG. 8 is a side sectional view of a lighting device of a fifth embodiment of the present invention.
【図９】本発明の第六実施形態の照明装置の側断面図で
ある。FIG. 9 is a side sectional view of an illumination device according to a sixth embodiment of the present invention.
【図１０】本発明の第七実施形態の照明装置の斜視図で
ある。FIG. 10 is a perspective view of a lighting device according to a seventh embodiment of the present invention.
【図１１】図１０に示される凹凸部の拡大断面図であ
る。FIG. 11 is an enlarged cross-sectional view of the uneven portion shown in FIG.
【図１２】図１０に示される凹凸部の拡大斜視図であ
る。FIG. 12 is an enlarged perspective view of the uneven portion shown in FIG.
【図１３】図１０の照明装置のXIII−XIII線に沿った断
面図である。13 is a sectional view taken along line XIII-XIII of the lighting device of FIG.
【図１４】特許第３０１２４６２号に開示されている導
光板の断面図である。FIG. 14 is a sectional view of a light guide plate disclosed in Japanese Patent No. 3012462.
１１ 光源 １２ 導光板 １３ 凹部 １４ 凸部 １６ 底面 １７ 近位端面 １８ 遠位端面 １９ 上面 11 light source 12 Light guide plate 13 recess 14 convex 16 Bottom 17 Proximal end face 18 Distal end face 19 upper surface
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｆ２１Ｙ 103:00 Ｆ２１Ｙ 103:00 ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) F21Y 103: 00 F21Y 103: 00
Claims (6)
らの光を内部に取り込みこれを被照明物体に照射するた
めの導光板とを備えており、前記導光板は、前記光源か
らの光線を被照明物体に向けて偏向するための複数の反
射面と、前記反射面に臨界角より小さい入射角で入射し
前記反射面を透過した光線を少なくとも屈折作用により
導光板へ戻す凸部とを有している、照明装置。1. A light source for emitting light, and a light guide plate for taking in the light from the light source into the interior and irradiating the object to be illuminated with the light, wherein the light guide plate is provided from the light source. A plurality of reflecting surfaces for deflecting the light rays toward the object to be illuminated, and a convex portion for returning the light rays incident on the reflecting surfaces at an incident angle smaller than a critical angle and passing through the reflecting surfaces to at least the light guide plate by refraction. Having a lighting device.
ら遠い側の反射面の遠位端を一つの頂点とするほぼ三角
形の断面形状を有している。2. The convex portion according to claim 1, wherein the convex portion has a substantially triangular cross-sectional shape with one apex at the distal end of the reflecting surface far from the light source.
の高さと、前記凸部の遠位斜面の遠位端の高さとが異な
っており、従って、それらの間に位置する平面部が導光
板の底面に対して傾きを有している、照明装置。3. The flat surface portion according to claim 1, wherein the height of the proximal end of the reflecting surface is different from the height of the distal end of the distal inclined surface of the convex portion, and thus is located between them. The illuminating device having a tilt with respect to the bottom surface of the light guide plate.
ｈ、前記凸部の高さをｄとしたとき、ｈ／ｄが光源から
離れるに従って小さくなっていく、照明装置。4. The lighting device according to claim 1, wherein h / d becomes smaller as the distance from the light source increases, where h is the depth of the reflecting surface and d is the height of the convex portion.
部を挟んで相対して形成されている、照明装置。5. The lighting device according to claim 1, wherein the reflecting surfaces are formed opposite to each other with the convex portion interposed therebetween.
光を内部に取り込みこれを被照明物体に照射するための
導光板とを備えており、前記導光板は互いに離れて存在
する複数の凹凸部を有しており、前記凹凸部は、回転対
称な形状の凹部と、これに取り囲まれている回転対称な
形状の凸部とを含んでおり、前記凹部の外側斜面は光源
からの光線を被照明物体に向けて偏向するための反射面
として機能し、前記凸部は、前記凹部の外側斜面を透過
した光線を少なくとも屈折作用により導光板に戻す、照
明装置。6. A light source for emitting light, and a light guide plate for taking in the light from the light source and irradiating the object to be illuminated with the light, the plurality of light guide plates being separated from each other. The concave and convex portion includes a concave portion having a rotationally symmetrical shape and a convex portion having a rotationally symmetrical shape surrounded by the concave portion, and the outer slope of the concave portion is formed from a light source. An illuminating device which functions as a reflecting surface for deflecting a light beam toward an object to be illuminated, wherein the convex part returns the light beam transmitted through the outer slope of the concave part to the light guide plate by at least the refracting action.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001306723A JP2003114337A (en) | 2001-10-02 | 2001-10-02 | Illuminator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001306723A JP2003114337A (en) | 2001-10-02 | 2001-10-02 | Illuminator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003114337A true JP2003114337A (en) | 2003-04-18 |
Family
ID=19126317
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001306723A Withdrawn JP2003114337A (en) | 2001-10-02 | 2001-10-02 | Illuminator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003114337A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005025972A (en) * | 2003-06-30 | 2005-01-27 | Fujitsu Kasei Kk | Surface lighting system and liquid crystal display device |
| CN102759771A (en) * | 2011-04-29 | 2012-10-31 | 中强光电股份有限公司 | Light guide plate and light source module |
| WO2014067006A1 (en) * | 2012-10-31 | 2014-05-08 | Fluxwerx Illumination Inc. | Light extraction elements |
| JPWO2018185585A1 (en) * | 2017-04-03 | 2020-03-12 | 株式会社半導体エネルギー研究所 | Display device, input / output device, information processing device |
| TWI845276B (en) | 2023-04-25 | 2024-06-11 | 瀚宇彩晶股份有限公司 | Light guide plate of front light module, front light module and display device |
-
2001
- 2001-10-02 JP JP2001306723A patent/JP2003114337A/en not_active Withdrawn
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005025972A (en) * | 2003-06-30 | 2005-01-27 | Fujitsu Kasei Kk | Surface lighting system and liquid crystal display device |
| CN102759771A (en) * | 2011-04-29 | 2012-10-31 | 中强光电股份有限公司 | Light guide plate and light source module |
| JP2012234801A (en) * | 2011-04-29 | 2012-11-29 | Ctx Opto Electronics Corp | Light guide plate, and light source module |
| US8764269B2 (en) | 2011-04-29 | 2014-07-01 | Coretronic Corporation | Light guide plate and light source module |
| TWI452359B (en) * | 2011-04-29 | 2014-09-11 | Coretronic Corp | Light guide plate and light source module |
| WO2014067006A1 (en) * | 2012-10-31 | 2014-05-08 | Fluxwerx Illumination Inc. | Light extraction elements |
| US9733411B2 (en) | 2012-10-31 | 2017-08-15 | Fluxwerx Illumination Inc. | Light extraction elements |
| US9823406B2 (en) | 2012-10-31 | 2017-11-21 | Fluxwerx Illumination Inc. | Light extraction elements |
| JPWO2018185585A1 (en) * | 2017-04-03 | 2020-03-12 | 株式会社半導体エネルギー研究所 | Display device, input / output device, information processing device |
| JP7191816B2 (en) | 2017-04-03 | 2022-12-19 | 株式会社半導体エネルギー研究所 | Display device |
| TWI845276B (en) | 2023-04-25 | 2024-06-11 | 瀚宇彩晶股份有限公司 | Light guide plate of front light module, front light module and display device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20041207 |