JP2003161839A - Lightguide, surface light-emitting body and liquid crystal display - Google Patents
Lightguide, surface light-emitting body and liquid crystal displayInfo
- Publication number
- JP2003161839A JP2003161839A JP2001363360A JP2001363360A JP2003161839A JP 2003161839 A JP2003161839 A JP 2003161839A JP 2001363360 A JP2001363360 A JP 2001363360A JP 2001363360 A JP2001363360 A JP 2001363360A JP 2003161839 A JP2003161839 A JP 2003161839A
- Authority
- JP
- Japan
- Prior art keywords
- light
- light guide
- receiving end
- shape
- face
- 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.)
- Granted
Links
Landscapes
- Planar Illumination Modules (AREA)
- Light Guides In General And Applications Therefor (AREA)
- Liquid Crystal (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は導光体、面発光体お
よび液晶表示装置に係り、特に、液晶表示装置の照明に
用いるとき優れた画像輝度と照明の均一性とが得られる
導光体、この導光体を構成要素として含む面発光体、お
よびこの面発光体を用いた液晶表示装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide, a surface light emitter, and a liquid crystal display device, and more particularly, to a light guide having excellent image brightness and uniform illumination when used for illumination of a liquid crystal display device. The present invention relates to a surface light emitter including this light guide as a constituent element, and a liquid crystal display device using the surface light emitter.
【０００２】[0002]
【従来の技術】携帯電話機や携帯用表示端末機などに多
く用いられる反射型液晶表示装置は、一般に表示画面の
照明を外光に依存しているので、外光が不足する環境下
では表示画像の視認性が極端に低下するという問題があ
った。この問題を解決するために、反射型の液晶表示ユ
ニットの表示面上にフロントライトと呼ばれる面発光体
を装備して補助光源として用いる液晶表示装置が提案さ
れている。この面発光体を備えた液晶表示装置は、昼間
の屋外や明るい室内など外光が十分に得られる環境では
外光により表示画面を照明し、暗い環境下では前記面発
光体を発光させて表示画面全体を照明している。2. Description of the Related Art Reflective liquid crystal display devices, which are often used in mobile phones, portable display terminals, etc., generally rely on external light for illumination of the display screen. However, there was a problem that the visibility of was extremely reduced. In order to solve this problem, there has been proposed a liquid crystal display device in which a surface light emitter called a front light is mounted on the display surface of a reflective liquid crystal display unit and used as an auxiliary light source. A liquid crystal display device equipped with this surface light emitter illuminates the display screen with outside light in an environment where sufficient external light is obtained such as outdoors in the daytime or in a bright room, and displays the surface light emitter in a dark environment to emit light. Illuminates the entire screen.
【０００３】従来から用いられている前記液晶表示装置
の一例を図１９および図２０（ａ）（ｂ）に示す。図１
９は前記液晶表示装置の斜視図であり、図２０（ａ）は
前記液晶表示装置の一部を表示面側から見た平面図、図
２０（ｂ）はその線Ｘ−Ｘで切った断面図である。この
液晶表示装置１００は、面発光体１０１と液晶表示ユニ
ット５０とからなっている。面発光体１０１は概略、光
源１０と導光体１２０と板状導光部３０とからなってい
る。光源１０は冷陰極管またはＬＥＤなどの発光素子か
らなり、導光体１２０および板状導光部３０は透明なア
クリル樹脂などを射出成形して形成されている。液晶表
示ユニット５０は板面の垂線方向に透光性の液晶表示板
５１と反射層５２とからなっている。An example of the above-mentioned liquid crystal display device which has been conventionally used is shown in FIGS. 19 and 20 (a) and 20 (b). Figure 1
9 is a perspective view of the liquid crystal display device, FIG. 20 (a) is a plan view of a part of the liquid crystal display device seen from the display surface side, and FIG. 20 (b) is a cross section taken along line XX. It is a figure. The liquid crystal display device 100 includes a surface light emitter 101 and a liquid crystal display unit 50. The surface light emitter 101 is roughly composed of a light source 10, a light guide 120, and a plate-shaped light guide section 30. The light source 10 is composed of a cold cathode tube or a light emitting element such as an LED, and the light guide 120 and the plate-shaped light guide section 30 are formed by injection molding a transparent acrylic resin or the like. The liquid crystal display unit 50 includes a translucent liquid crystal display plate 51 and a reflective layer 52 in a direction perpendicular to the plate surface.
【０００４】導光体１２０は、細長い角柱状に成形さ
れ、その受光端面１２１が光源１０からの光を受光する
と、入射した光を長手方向（図１９のＺ−Ｚ方向）に沿
う出射面１２２から帯状光束Ｌ1として出射するように
構成されている。この導光体１２０は、その出射面１２
２と対向する側面（反射面）１２３に、複数のプリズム
状傾斜面１２４…が形成されている。このプリズム状傾
斜面１２４…は何れもその稜線１２５が出射面１２２の
幅方向（図１９のＹ軸方向）に延びていて、光源１０か
ら導光体１２０に入射した光のうち、このプリズム状傾
斜面１２４…に射突した光の多くは反射して出射面１２
２から帯状光束Ｌ1として出射される。このときプリズ
ム状傾斜面１２４…の数や配置、それぞれの傾斜角など
を適宜に選択することにより導光体１２０の出射面１２
２から出射される帯状光束Ｌ1の輝度と均一性が良好に
バランスするよう調整される。The light guide 120 is formed into an elongated prism shape, and when the light receiving end face 121 thereof receives the light from the light source 10, the incident light is emitted along the longitudinal direction (Z-Z direction in FIG. 19) of the emission face 122. Is emitted as a strip-shaped light beam L 1 . The light guide 120 has an exit surface 12
A plurality of prism-shaped inclined surfaces 124 ... Are formed on the side surface (reflection surface) 123 facing the surface 2. The ridge 125 of each of the prism-shaped inclined surfaces 124 extends in the width direction of the emission surface 122 (Y-axis direction in FIG. 19), and this prism-shaped inclined surface is included in the light incident on the light guide body 120 from the light source 10. Most of the light impinging on the inclined surface 124 is reflected and emitted from the emission surface 12.
2 is emitted as a band-shaped light beam L 1 . At this time, the exit surface 12 of the light guide body 120 is appropriately selected by appropriately selecting the number and arrangement of the prismatic inclined surfaces 124, the respective inclination angles, and the like.
The brightness and the uniformity of the band-shaped light beam L 1 emitted from the beam No. 2 are adjusted to be well balanced.
【０００５】板状導光部３０は板状に成形され、導光体
１２０の出射面１２２から出射した帯状光束Ｌ1を側面
（入射側面）３１から受光し、板面の一方である発光面
３２から面状光束Ｌ2として液晶表示ユニット５０の液
晶表示板５１に向けて出射するように構成されている。
板状導光部３０の発光面３２と対向する面（対向面）３
３には、複数のプリズム状傾斜面３４…が形成されてい
る。このプリズム状傾斜面３４…は何れもその稜線３５
が導光体１２０の長手（Ｚ−Ｚ）方向に延びていて、入
射側面３１から入射した帯状光のうち、このプリズム状
傾斜面３４…に射突した光の多くは反射して発光面３２
から面状光束Ｌ2として出射される。このときプリズム
状傾斜面３４…の数や配置、それぞれの傾斜角などを適
宜に選択することにより板状導光部３０の発光面３２か
ら出射される面状光束Ｌ2の輝度と均一性が良好にバラ
ンスするよう調整される。The plate-shaped light guide section 30 is formed in a plate shape, receives the band-shaped light beam L 1 emitted from the emission surface 122 of the light guide body 120 from the side surface (incident side surface) 31, and is one of the plate surfaces. The surface light flux L 2 is emitted from 32 toward the liquid crystal display plate 51 of the liquid crystal display unit 50.
A surface (opposing surface) 3 that faces the light emitting surface 32 of the plate-shaped light guide portion 30.
3, a plurality of prismatic inclined surfaces 34 ... Is formed. Each of the prismatic inclined surfaces 34 ...
Extend in the longitudinal (Z-Z) direction of the light guide body 120, and of the band-shaped light incident from the incident side surface 31, most of the light impinging on the prismatic inclined surface 34 ... Is reflected and the light-emitting surface 32 is reflected.
Is emitted as a planar light beam L 2 . At this time, the brightness and the uniformity of the planar light flux L 2 emitted from the light emitting surface 32 of the plate-shaped light guide section 30 can be improved by appropriately selecting the number and arrangement of the prismatic inclined surfaces 34, and the respective inclination angles. Adjusted for good balance.
【０００６】液晶表示ユニット５０の液晶表示板５１は
一般に用いられているものであって、液晶分子の駆動に
よって、表示面に垂直な光の透過／不透過が動的に制御
される。液晶表示板５１に向けて出射された光のうち、
液晶分子の配向によって板面の垂線方向に光透過性とさ
れた液晶表示板５１の部分を透過した光は、反射層５２
によって反射され、再び液晶表示板５１を垂直方向に透
過し、更に板状導光部３０も透過する。これによって液
晶表示板５１により形成された画像が板状導光部３０の
上方から視認できるようになる。The liquid crystal display plate 51 of the liquid crystal display unit 50 is generally used, and the transmission / non-transmission of light perpendicular to the display surface is dynamically controlled by driving the liquid crystal molecules. Of the light emitted toward the liquid crystal display plate 51,
The light transmitted through the portion of the liquid crystal display panel 51, which is made light-transmissive in the direction perpendicular to the plate surface due to the orientation of the liquid crystal molecules, is reflected
Is reflected by the liquid crystal display panel 51 and is transmitted through the liquid crystal display panel 51 in the vertical direction again, and further transmitted through the plate-shaped light guide portion 30. This allows the image formed by the liquid crystal display plate 51 to be viewed from above the plate-shaped light guide unit 30.
【０００７】[0007]
【発明が解決しようとする課題】前記構成の液晶表示装
置１００は小型の携帯用機器に多く用いられるので、面
発光体１０１による照明に際しては、光源１０の小型化
と共に消費電力を極力低減し、なおかつ充分な輝度と照
明の均一性とを得ることが求められる。しかし、光源１
０からの光は一般に拡散性であることに加え、面発光体
１０１は前記のように光の進路が導光体１２０内と面状
導光部３０内との２箇所でほぼ直角方向に反射を繰り返
し、しかもその反射が入射光の一部しか利用できない前
記プリズム状傾斜面に依存しているので導光損失が大き
く、出射光に充分な輝度が得られないばかりか照明ムラ
も大きかった。特に導光体１２０における導光効率の悪
さが指摘されていた。本発明は前記の課題を解決するた
めになされたものであり、従ってその目的は、出射光に
高い輝度が得られると共に照明ムラも軽減された導光
体、およびこれを用いた面発光体並びに液晶表示装置を
提供することにある。Since the liquid crystal display device 100 having the above-mentioned configuration is often used in small portable equipment, when the surface light emitter 101 is used for illumination, the light source 10 is downsized and the power consumption is reduced as much as possible. Moreover, it is required to obtain sufficient brightness and uniformity of illumination. But light source 1
The light from 0 is generally diffusive, and as described above, in the surface light emitter 101, the paths of the light are reflected in two directions, that is, in the light guide 120 and in the planar light guide portion 30 in a substantially perpendicular direction. However, since the reflection depends on the prism-shaped inclined surface where only a part of the incident light can be used, the light guide loss is large, and sufficient brightness cannot be obtained for the emitted light, and the illumination unevenness is large. In particular, poor light guiding efficiency in the light guide 120 has been pointed out. The present invention has been made to solve the above-mentioned problems, and therefore an object thereof is to provide a light guide body in which high brightness is obtained for emitted light and illumination unevenness is reduced, and a surface light emitting body using the light guide body. An object is to provide a liquid crystal display device.
【０００８】[0008]
【課題を解決するための手段】前記の課題を解決するた
めに本発明は、端面から入射した光を長手方向に沿う側
面（出射面）から帯状光束として出射するように構成さ
れた柱状の導光体であって、前記光を受光する端面（受
光端面）が凸面形状に成形された導光体を提供する。本
発明者らは、小型省電力の光源を用い、しかも反射型液
晶表示装置のフロントライトとして充分な照度と照明の
均一性が得られる面発光体を開発すべく鋭意研究の結
果、面発光体の構成要素である導光体の受光端面を凸面
形状に成形することにより、光源から入射された光の拡
散を適度に制御し、導光体の出射面から光を帯状光束と
して効率よく均一に出射させ得ることを見出し本発明に
到達した。すなわち、従来のこの種の導光体において
は、受光端面が平坦であったので、光源から入射した光
が導光体内で広い角度に拡散し、出射面以外の側面から
光が漏洩したり直進したりして充分な光量が出射面から
出射せず、光の利用効率が悪かった。本発明の導光体に
よれば、導光体内部の光の拡散が好適に制御され、出射
面以外の側面から漏洩したり直進したりすることによる
光の損失を抑制することができ、出射面からより多くの
光をより均一な輝度の帯状光束として出射させることが
できる。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a columnar guide configured to emit light incident from an end face as a band-shaped light flux from a side face (emission face) along the longitudinal direction. Provided is a light guide, which has a convex end face (light receiving end face) for receiving the light. The present inventors have earnestly studied to develop a surface light emitter that uses a small power-saving light source and can obtain sufficient illuminance and illumination uniformity as a front light of a reflective liquid crystal display device. By shaping the light-receiving end face of the light guide, which is a component of the above, into a convex shape, the diffusion of the light incident from the light source is controlled appropriately, and the light from the exit face of the light guide is efficiently and uniformly made as a band-shaped light flux. They have found that they can be emitted and have reached the present invention. That is, in the conventional light guide of this type, since the light receiving end surface is flat, the light incident from the light source is diffused at a wide angle in the light guide, and the light leaks or goes straight from the side surface other than the emission surface. However, a sufficient amount of light was not emitted from the emission surface, and the light utilization efficiency was poor. According to the light guide of the present invention, the diffusion of light inside the light guide is suitably controlled, and it is possible to suppress the loss of light due to leakage or straight traveling from side surfaces other than the emission surface. More light can be emitted from the surface as a band-shaped light flux with more uniform brightness.
【０００９】前記受光端面は、稜線が前記出射面の幅方
向に延びる１以上の筒形凸レンズの形状に成形されてい
ることが好ましい。前記筒形凸レンズ形状の曲率半径
は、当該形状の弦長の０．５倍〜１．０倍の範囲内とさ
れていることが好ましい。稜線が出射面の幅方向に延び
る筒形凸レンズ（シリンドリカルレンズ）形状を受光端
面に形成すれば、この筒形凸レンズ形状の曲率を選択す
ることにより出射面と、これに対向する側面（反射面）
との間の光の拡散角を好適に制御することができ、帯状
光束の出射光量を向上させることができる。筒形凸レン
ズ形状は受光端面に１条だけ形成されていてもよく、２
条以上が平行して形成されていてもよい。実験の結果、
筒形凸レンズ形状の曲率半径は、当該筒形凸レンズ形状
の弦長（断面弧の弦の長さ）の０．５倍〜１．０倍の範
囲内とすることがより効果的であることがわかった。It is preferable that the light receiving end surface is formed in the shape of one or more cylindrical convex lenses whose ridge lines extend in the width direction of the exit surface. The radius of curvature of the cylindrical convex lens shape is preferably within a range of 0.5 times to 1.0 times the chord length of the shape. If a cylindrical convex lens (cylindrical lens) shape whose ridge extends in the width direction of the exit surface is formed on the light-receiving end surface, the exit surface and the side surface (reflection surface) facing the exit surface can be selected by selecting the curvature of this cylindrical convex lens shape.
The diffusion angle of light between and can be suitably controlled, and the amount of emitted light of the band-shaped light flux can be improved. The cylindrical convex lens shape may have only one line formed on the light receiving end surface.
The stripes or more may be formed in parallel. results of the experiment,
It is more effective that the radius of curvature of the cylindrical convex lens shape is within a range of 0.5 times to 1.0 times the chord length of the cylindrical convex lens shape (length of chord of cross section arc). all right.
【００１０】前記受光端面は、１以上の球面凸レンズの
形状に成形されていてもよい。前記球面凸レンズ形状の
曲率半径は、当該形状の弦長の０．５倍〜１．０倍の範
囲内とされていることが好ましい。受光端面に球面凸レ
ンズ形状を形成すれば、この球面凸レンズ形状の曲率を
選択することにより出射面と反射面との間の光の拡散角
を好適に制御することができるばかりでなく、導光体の
他の側面に対する光の拡散も制御できるので、帯状光束
の出射光量と均一性とを更に向上させることができる。
球面凸レンズ形状は受光端面全体を覆うように１個だけ
成形されていてもよく、２個以上が隣接は位置された形
状に成形されていてもよい。実験の結果、球面凸レンズ
形状の曲率半径は、当該球面凸レンズ形状の弦長の０．
５倍〜１．０倍の範囲内とすると、より効果的であるこ
とがわかった。球面凸レンズ形状の曲率は帯状光束の出
射方向と出射面の幅方向とで同じでも異なっていてもよ
い。The light-receiving end face may be formed in the shape of one or more spherical convex lenses. It is preferable that the radius of curvature of the spherical convex lens shape is within a range of 0.5 times to 1.0 times the chord length of the shape. If a spherical convex lens shape is formed on the light receiving end surface, not only can the light diffusion angle between the emitting surface and the reflecting surface be suitably controlled by selecting the curvature of this spherical convex lens shape, but also the light guide body. Since it is possible to control the diffusion of light to the other side surface of the light source, it is possible to further improve the amount of emitted light and the uniformity of the band-shaped light flux.
Only one spherical convex lens shape may be formed so as to cover the entire light receiving end surface, or two or more spherical convex lens shapes may be formed so that adjacent ones are positioned. As a result of the experiment, the radius of curvature of the spherical convex lens shape is 0.
It was found that it was more effective when it was within the range of 5 times to 1.0 times. The curvature of the spherical convex lens shape may be the same or different in the emission direction of the band-shaped light flux and the width direction of the emission surface.
【００１１】更に前記受光端面は、稜線が前記出射面の
幅方向に延びる１以上の凸プリズムの形状に成形に成形
されていてもよい。前記凸プリズム形状の底辺を挟む仰
角は、２°〜４０°の範囲内とされていることが好まし
い。受光端面に凸プリズム形状（断面三角形）を形成す
れば、この凸プリズム形状の仰角を選択することにより
出射面と反射面との間の光の拡散角を好適に制御するこ
とができ、帯状光束の出射光量と均一性とを向上させる
ことができる。凸プリズム形状は受光端面に１条だけ形
成されていてもよく、２条以上が平行して形成されてい
てもよい。実験の結果、凸プリズム形状の仰角（底辺と
斜辺とが挟む角）は、２°〜４０°の範囲内とすること
がより効果的であることがわかった。凸プリズム形状の
仰角は底辺を挟む双方が同じでも異なっていてもよい。Further, the light-receiving end surface may be molded into a shape of one or more convex prisms whose ridge lines extend in the width direction of the exit surface. The elevation angle sandwiching the base of the convex prism shape is preferably within the range of 2 ° to 40 °. If a convex prism shape (triangular cross section) is formed on the light-receiving end surface, the diffusion angle of light between the emitting surface and the reflecting surface can be suitably controlled by selecting the elevation angle of this convex prism shape. It is possible to improve the amount of emitted light and the uniformity. As for the convex prism shape, only one line may be formed on the light receiving end surface, or two or more lines may be formed in parallel. As a result of the experiment, it was found that it is more effective to set the elevation angle (angle between the base and the hypotenuse) of the convex prism shape to be within the range of 2 ° to 40 °. The elevation angles of the convex prism shape may be the same or different on both sides of the base.
【００１２】更に前記受光端面は、稜線が前記出射面の
幅方向に延びる４分割筒形凸レンズ部と、前記稜線を共
有する片側傾斜面のプリズム部とからなる１以上の複合
型凸面形状に成形されていてもよい。ここで「４分割筒
形凸レンズ部」とは、円柱を軸心に沿って４等分した形
状を意味する。この複合型凸面形状によっても、出射面
と反射面との間の光の拡散角を好適に制御することがで
き、帯状光束の出射光量と均一性とを向上させることが
できることがわかった。前記複合型凸面形状は受光端面
に１条だけ形成されていてもよく、２条以上が平行して
形成されていてもよい。また４分割筒形凸レンズ部とプ
リズム部とは、これらの組が１稜線を共有していればよ
いので、それらの配列順序は特に限定されない。Further, the light-receiving end surface is formed into one or more composite convex surfaces having a four-divided cylindrical convex lens portion whose ridge line extends in the width direction of the output surface and a prism portion having a sloping surface on one side that shares the ridge line. It may have been done. Here, the “four-divided cylindrical convex lens portion” means a shape obtained by dividing a cylinder into four equal parts along the axis. It was also found that this composite convex shape can also appropriately control the diffusion angle of light between the emission surface and the reflection surface, and can improve the emission light amount and uniformity of the band-shaped light flux. The composite convex surface shape may be formed on the light-receiving end surface in only one line, or in two or more lines in parallel. Further, the four-divided cylindrical convex lens portion and the prism portion only need to share one ridgeline between these groups, and therefore the arrangement order thereof is not particularly limited.
【００１３】本発明の導光体は、前記出射面と対向する
側面（反射面）に、前記受光端面から入射した光を前記
出射面方向に反射する反射手段が形成されていることが
好ましい。この反射手段は、稜線が反射面の幅方向に延
びる複数のプリズム状傾斜面からなっていることが好ま
しい。これによって帯状光束の輝度と均一性を更に向上
することができる。In the light guide of the present invention, it is preferable that the side surface (reflection surface) facing the emission surface is provided with a reflection means for reflecting the light incident from the light receiving end surface toward the emission surface. The reflecting means preferably comprises a plurality of prismatic inclined surfaces whose ridge lines extend in the width direction of the reflecting surface. As a result, the brightness and uniformity of the band-shaped light flux can be further improved.
【００１４】本発明はまた、前記の何れかに記載の導光
体と板状導光部とを有し、前記板状導光部は、前記導光
体から出射した前記帯状光束を側面（入射側面）で受光
し、板面から面状光束として出射するように構成された
面発光体を提供する。ここで面状光束は板状導光部の一
方の板面から出射されてもよくまたは双方の板面から同
時に出射されてもよい。また、面状光束が出射しない側
の板面は、板面の垂線方向に光透過性であっても光反射
性であってもよい。面発光体の面状光束を出射する側の
板面を「発光面」、これと対向する側の板面を「対向
面」という。この面発光体は、前記導光体が従来型の導
光体よりも出射光の輝度および均一性において優れてい
るので、板状導光部が従来型のものであっても、全体と
して発光面から出射される面状光束の輝度と均一性が向
上している。The present invention also includes the light guide according to any one of the above, and a plate-shaped light guide portion, wherein the plate-shaped light guide portion has a side surface of the strip-shaped light flux emitted from the light guide body. Provided is a surface light emitter configured to receive light on an incident side surface) and to emit it as a planar light flux from a plate surface. Here, the planar light flux may be emitted from one plate surface of the plate-shaped light guide portion or may be emitted simultaneously from both plate surfaces. Further, the plate surface on the side where the planar light flux is not emitted may be light transmissive or light reflective in the direction perpendicular to the plate surface. The plate surface of the surface light emitter on the side where the planar light flux is emitted is referred to as a "light emitting surface", and the plate surface on the side opposite to this is referred to as an "opposing surface". In this surface light emitter, since the light guide body is superior to the conventional light guide body in the brightness and uniformity of the emitted light, even if the plate-shaped light guide portion is the conventional light guide body, the light emission as a whole is achieved. The brightness and uniformity of the planar light flux emitted from the surface are improved.
【００１５】前記において板状導光部は板面の垂線方向
に光透過性であり、かつ前記入射側面から入射した前記
帯状光束を一方の板面（発光面）から面状光束として出
射する反射手段が設けられていることが好ましい。この
反射手段は、対向面に形成され、稜線が導光体の長手方
向に延びる複数のプリズム状傾斜面からなっていること
が好ましい。これによって本発明の面発光体は面状光束
を１方向（発光面）に指向して出射できるようになり、
かつ光が前記面発光体を垂直に透過できるようになり、
本発明の面発光体を反射型液晶表示装置のフロントライ
トとして使用できるようになる。In the above description, the plate-shaped light guide portion is light-transmissive in the direction perpendicular to the plate surface, and is a reflection that emits the band-shaped light beam incident from the incident side surface as a surface light beam from one plate surface (light emitting surface). Means are preferably provided. It is preferable that the reflecting means is formed on opposite surfaces and has a plurality of prismatic inclined surfaces whose ridge lines extend in the longitudinal direction of the light guide. As a result, the surface light emitter of the present invention can emit the planar light beam in one direction (light emitting surface).
And the light can be transmitted vertically through the surface light emitter,
The surface light emitter of the present invention can be used as a front light of a reflective liquid crystal display device.
【００１６】本発明は更に、前記の面発光体と液晶表示
ユニットとを備えた液晶表示装置を提供する。本発明の
液晶表示装置は、前記本発明の面発光体を液晶表示面の
照明に用いるので小型省電力の光源を用いながら明るく
視認性の高い画面が得られる。前記の面発光体と液晶表
示ユニットとの組合わせ順序は特に限定されない。例え
ば板状導光部が板面の垂線方向に光透過性であり、かつ
入射側面から入射した帯状光束が面状光束として一方の
発光面から出射されるタイプの面発光体を上層に配置
し、その下に反射型液晶表示ユニットを表示面が前記発
光面と対向するように配置すれば、本発明の面発光体を
フロントライトとする反射型液晶表示装置が得られる。
また反射層を持たない透光性の液晶表示板を上層に配置
し、その下に、板状導光部の対向面を光反射性とした本
発明の面発光体を、その発光面が液晶表示板の裏面と対
向するように配置すれば、前記面発光体をバックライト
とする反射型液晶表示装置が得られる。The present invention further provides a liquid crystal display device comprising the above-mentioned surface light emitter and a liquid crystal display unit. Since the liquid crystal display device of the present invention uses the surface light emitter of the present invention for illuminating the liquid crystal display surface, a bright and highly visible screen can be obtained while using a small power-saving light source. The order of combining the surface light emitter and the liquid crystal display unit is not particularly limited. For example, a surface light emitter of the type in which the plate-shaped light guide is light-transmissive in the direction perpendicular to the plate surface, and the band-shaped light beam incident from the incident side surface is emitted from one light emitting surface as a surface light beam is arranged in the upper layer. By arranging the reflection type liquid crystal display unit under the display type so that the display surface faces the light emitting surface, a reflection type liquid crystal display device using the surface light emitter of the present invention as a front light can be obtained.
Further, a translucent liquid crystal display plate having no reflective layer is arranged in the upper layer, and the surface emitting body of the present invention in which the facing surface of the plate-shaped light guide is made light reflective is provided below the light emitting surface. If it is arranged so as to face the back surface of the display plate, a reflective liquid crystal display device using the surface light emitter as a backlight can be obtained.
【００１７】[0017]
【発明の実施の形態】以下、本発明の実施の形態を図面
を参照して説明するが、本発明は以下の実施の形態に限
定されるものではない。また、本実施の形態において参
照される各図面は、本発明の思想を説明するためのもの
であり、各部の形状寸法は実際のものと異なる。Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following embodiments. Further, each drawing referred to in the present embodiment is for explaining the idea of the present invention, and the shape and size of each portion are different from actual ones.
【００１８】（実施形態１）図１は、本発明の実施形態
１の面発光体を示す平面図である。この面発光体１は概
略、二つの光源部１０，１０と、この光源部１０，１０
に挟まれた角柱状の導光体２０と、導光体２０の一側面
（出射面２２）に入射側面３１を対向させて延びる方形
の板状導光部３０とからなっている。図１においてこの
面発光体１は中央線（Ｘ−Ｘ）に関して左右対称に構成
されている。光源部１０，１０は発光素子１１としてＬ
ＥＤを内蔵するランプハウスからなり、それぞれ、一方
に設けられた照射窓から導光体２０のそれぞれの受光端
面２１に向けて光を照射するように配置されている。導
光体２０および板状導光部３０はいずれも透明なアクリ
ル樹脂から成形されている。(Embodiment 1) FIG. 1 is a plan view showing a surface light emitter according to Embodiment 1 of the present invention. This surface light emitter 1 is roughly composed of two light source units 10 and 10, and the light source units 10 and 10.
It is composed of a prismatic light guide body 20 sandwiched between the light guide body 20 and a rectangular plate-like light guide portion 30 that extends with one side surface (emission surface 22) of the light guide body 20 with the incident side surface 31 facing. In FIG. 1, the surface light emitter 1 is configured symmetrically with respect to the center line (XX). The light source units 10 and 10 are L as a light emitting element 11.
The lamp house has a built-in ED and is arranged so as to irradiate light from the irradiation window provided on one side toward the respective light receiving end faces 21 of the light guide 20. Both the light guide body 20 and the plate-shaped light guide section 30 are made of transparent acrylic resin.
【００１９】図２は、導光体２０の端部近辺を示す斜視
図である。図１および図２において、導光体２０は概
略、細長い角柱状に成形され、その長手方向に延びる４
側面のうち、図示しない板状導光部３０の入射側面３１
と対向して配置された側面が導光体２０に入射した光を
出射する出射面２２とされ、この出射面２２と対向する
側面が反射面２３とされている。反射面２３には複数の
プリズム状傾斜面２４…が形成されている。このプリズ
ム状傾斜面２４…は、何れもその稜線２５が出射面２２
の幅方向、すなわち導光体２０の厚みＴ方向に延びてい
て、導光体２０に入射した光を出射面２２側に均一に反
射する形状に成形されている。図示しないが出射面２２
を除く導光体２０の３方の側面は全て反射膜により覆わ
れている。FIG. 2 is a perspective view showing the vicinity of the end portion of the light guide 20. 1 and 2, the light guide 20 is generally formed into an elongated prism shape and extends in the longitudinal direction thereof.
Of the side surfaces, the incident side surface 31 of the plate-shaped light guide unit 30 (not shown)
The side surface arranged opposite to is a light emitting surface 22 that emits the light incident on the light guide 20, and the side surface facing the light emitting surface 22 is a reflecting surface 23. A plurality of prismatic inclined surfaces 24 ... Are formed on the reflecting surface 23. The ridge lines 25 of the prismatic inclined surfaces 24 ...
In the width direction, that is, in the thickness T direction of the light guide body 20, and is shaped to uniformly reflect the light incident on the light guide body 20 toward the emission surface 22 side. Although not shown, the exit surface 22
The three side surfaces of the light guide body 20 except for are all covered with a reflective film.
【００２０】導光体２０の双方の端面は、それぞれ光源
部１０から照射された光を受光する受光端面２１とされ
ている。これらの受光端面２１，２１は何れもそれぞれ
の光源部１０方向に凸となる筒形凸レンズ（シリンドリ
カルレンズ）の形状に成形されている。この筒形凸レン
ズ形状は、図２のＹ−Ｙで示す稜線の方向が、導光体２
０の厚みＴ方向に延びていて、その曲率半径ｒは、この
筒形凸レンズ形状の弦長Ｃ（この場合は導光体２０の幅
Ｗに等しい）の０．５倍〜１．０倍の範囲内とされてい
る。ここで弦長Ｃとは筒形凸レンズ形状の断面弧の弦の
長さであり、導光体の幅Ｗとは、出射面２２と反射面２
３との離間距離である。この受光端面２１の筒形凸レン
ズ形状が本実施形態の特徴となっている。Both end surfaces of the light guide body 20 are light receiving end surfaces 21 for receiving the light emitted from the light source section 10, respectively. Each of these light-receiving end faces 21 and 21 is formed in the shape of a cylindrical convex lens (cylindrical lens) that is convex in the direction of the respective light source unit 10. In this cylindrical convex lens shape, the direction of the ridgeline indicated by YY in FIG.
It extends in the thickness T direction of 0 and its radius of curvature r is 0.5 to 1.0 times the chord length C of this cylindrical convex lens shape (which is equal to the width W of the light guide 20 in this case). It is within the range. Here, the chord length C is the length of the chord of the cross section arc of the cylindrical convex lens shape, and the width W of the light guide is the emission surface 22 and the reflection surface 2.
3 is the separation distance from 3. The cylindrical convex lens shape of the light receiving end face 21 is a feature of this embodiment.
【００２１】図３は本実施形態の面発光体１と液晶表示
ユニット５０とを組合わせて構成した本発明の液晶表示
装置の一例を示す、図１の線Ｘ−Ｘで切った断面図であ
る。図１および図３において、板状導光部３０は概略方
形の平板状に成形されてなり、その一方の側面が入射側
面３１として導光体２０の出射面２２に対向して配置さ
れ、板状導光部３０の受光面とされている。FIG. 3 is a sectional view taken along line XX in FIG. 1, showing an example of the liquid crystal display device of the present invention constructed by combining the surface light emitting device 1 of the present embodiment and the liquid crystal display unit 50. is there. 1 and 3, the plate-shaped light guide unit 30 is formed in a substantially rectangular flat plate shape, and one side surface of the plate-shaped light guide unit 30 is disposed as an incident side surface 31 so as to face the emission surface 22 of the light guide body 20. The light-guiding section 30 serves as a light-receiving surface.
【００２２】板状導光部３０の板面の一方は液晶表示ユ
ニット５０の表示面５３と対向するように配置され、発
光面３２とされている。発光面３２と対向する外側の板
面は対向面３３とされている。対向面３３には複数のプ
リズム状傾斜面３４…が形成されている。このプリズム
状傾斜面３４…は、何れもその稜線３５が導光体２０の
出射面２２が延びる方向と平行になるように成形され、
かつ導光体２０から板状導光部３０に入射した光を発光
面３２の方向に均一に反射する形状に成形されている。One of the plate surfaces of the plate-shaped light guide portion 30 is arranged so as to face the display surface 53 of the liquid crystal display unit 50 and serves as a light emitting surface 32. The outer plate surface facing the light emitting surface 32 is a facing surface 33. A plurality of prismatic inclined surfaces 34 ... Are formed on the facing surface 33. Each of the prismatic inclined surfaces 34 ... Is molded so that its ridgeline 35 is parallel to the direction in which the emission surface 22 of the light guide 20 extends.
In addition, the light that has entered the plate-shaped light guide portion 30 from the light guide body 20 is shaped so as to be uniformly reflected in the direction of the light emitting surface 32.
【００２３】図３に示した液晶表示ユニット５０は液晶
表示板５１とその下層に配された反射層５２とからなっ
ている。液晶表示板５１は液晶層５４と、図示しないが
液晶層を駆動する電極と、この電極に断続的に電位を印
加する駆動回路と、偏光膜やカラーフィルタなどの光制
御板とを有し、液晶層５４の液晶分子の配向により透光
／遮光のスイッチングが行われるようになっている。液
晶表示板５１の構成や駆動方式は特に限定されるもので
はない。反射層５２は、一例を図４に示すように、有機
膜５５の表面に内面が球面の一部をなす多数の凹部５６
ａ…が重なり合うように連続して形成されており、この
有機膜５５上に反射膜５７が成膜されてなっている。液
晶表示板５１と反射層５２とは、液晶表示板５１の表示
面５３が板状導光部３０の発光面３２と対向するように
積層されることで、反射型液晶表示ユニットを構成して
いる。The liquid crystal display unit 50 shown in FIG. 3 comprises a liquid crystal display plate 51 and a reflective layer 52 disposed below the liquid crystal display plate 51. The liquid crystal display plate 51 has a liquid crystal layer 54, an electrode (not shown) for driving the liquid crystal layer, a drive circuit for intermittently applying a potential to this electrode, and a light control plate such as a polarizing film or a color filter, Switching between light transmission and light shielding is performed by the orientation of liquid crystal molecules of the liquid crystal layer 54. The configuration and driving method of the liquid crystal display plate 51 are not particularly limited. As shown in FIG. 4, the reflective layer 52 has a large number of recesses 56 whose inner surface is part of a spherical surface on the surface of the organic film 55.
.. are continuously formed so as to overlap with each other, and the reflection film 57 is formed on the organic film 55. The liquid crystal display plate 51 and the reflective layer 52 are laminated so that the display surface 53 of the liquid crystal display plate 51 faces the light emitting surface 32 of the plate-shaped light guide unit 30, thereby forming a reflective liquid crystal display unit. There is.
【００２４】次に図１〜図３を用い、本実施形態の面発
光体１の作用について説明する。まず概略の光の経路を
説明すると、光源部１０，１０から放射されたＬＥＤ光
は導光体２０のそれぞれの受光端面２１，２１から入射
し、導光体２０内に導入される。導光体２０内に導入さ
れた光は反射面２３に成形された複数のプリズム状傾斜
面２４…によって大部分の光は出射面２２の方向に反射
され、出射面２２から、この細長い面全体が光る帯状光
束Ｌ1として出射し、入射側面３１から板状導光部３０
内に導入される。板状導光部３０内に導入された光は、
対向面３３に成形された複数のプリズム状傾斜面３４…
によって大部分の光は発光面３２の方向に反射され、発
光面３２から、面全体が光る面状光束Ｌ2として液晶表
示ユニット５０の表示面５３を照射する。Next, the operation of the surface light emitter 1 of this embodiment will be described with reference to FIGS. First, a schematic light path will be described. LED light emitted from the light source units 10 and 10 enters from the light receiving end faces 21 and 21 of the light guide 20 and is introduced into the light guide 20. Most of the light introduced into the light guide 20 is reflected in the direction of the emission surface 22 by the plurality of prismatic inclined surfaces 24 formed on the reflection surface 23. Is emitted as a strip-shaped light flux L 1 and is emitted from the incident side surface 31 to the plate-shaped light guide portion 30.
Will be introduced in. The light introduced into the plate-shaped light guide section 30 is
A plurality of prismatic inclined surfaces 34 formed on the facing surface 33.
Accordingly, most of the light is reflected in the direction of the light emitting surface 32, and the light emitting surface 32 irradiates the display surface 53 of the liquid crystal display unit 50 as a planar light flux L 2 that illuminates the entire surface.
【００２５】液晶表示ユニットの表示面５３を照射した
光の内、液晶分子の配向によって遮光されることなく液
晶層５４を透過した光は反射層５２に達し、この反射層
５２によって反射され、再び液晶層５４を透過し、更に
板状導光部３０を透過して直進する。板状導光部３０
は、板面に対してほぼ垂直に入射する液晶表示ユニット
からの反射光を透過することができるので、液晶層５４
がパターン形成する画像光Ｌ3は対向面３３から外部に
出射され視認されるようになる。この板状導光部３０
は、入射側面３１以外の側面や上下の板面が、外光や光
源光の余分な反射や散乱に起因するヘイズやグレアを防
止し画像コントラストを高めるために反射防止膜が施さ
れていてもよい。Of the light that illuminates the display surface 53 of the liquid crystal display unit, the light that has passed through the liquid crystal layer 54 without being blocked by the orientation of the liquid crystal molecules reaches the reflective layer 52, is reflected by this reflective layer 52, and is again reflected. It passes through the liquid crystal layer 54, further passes through the plate-shaped light guide portion 30, and goes straight. Plate-shaped light guide 30
Can transmit the reflected light from the liquid crystal display unit that is incident almost perpendicularly to the plate surface, and therefore the liquid crystal layer 54
The image light L 3 that forms a pattern is emitted from the facing surface 33 to the outside and is visually recognized. This plate-shaped light guide section 30
Even if the side surfaces other than the incident side surface 31 and the upper and lower plate surfaces are provided with an antireflection film in order to prevent haze and glare caused by extra reflection and scattering of external light and light from the light source and enhance image contrast. Good.
【００２６】前記実施形態の面発光体１において、導光
体２０の受光端面２１の形状の効果を調べるため、筒形
凸レンズ形状の曲率半径ｒを種々変化させた導光体の試
作品を作成し、出射面２２から帯状光束として出射する
光の輝度とその分布を測定した。出射光の輝度の測定
は、出射面２２の長手方向に一方の端部から中央線Ｘ−
Ｘまでの長さ（半長）を１７等分してそれぞれを測定点
とし、図５に示すように、各測定点において、垂直線か
ら出射面２２の長手方向に±２０°の範囲内で測定視野
を振って輝度を測定し、その平均値を測定点における輝
度とした。In order to investigate the effect of the shape of the light-receiving end surface 21 of the light guide 20 in the surface light emitter 1 of the above-described embodiment, prototypes of light guides having various cylindrical convex lens-shaped curvature radii r are prepared. Then, the brightness and the distribution of the light emitted as a band-shaped light flux from the emission surface 22 were measured. The luminance of the emitted light is measured by measuring the center line X- from the one end in the longitudinal direction of the emitting surface 22.
The length (half length) up to X is divided into 17 equal parts, and each is set as a measurement point. As shown in FIG. 5, at each measurement point, within a range of ± 20 ° from the vertical line in the longitudinal direction of the emission surface 22. The measurement visual field was shaken to measure the luminance, and the average value was used as the luminance at the measurement point.
【００２７】（測定例１：平均出射光輝度）受光端面２
１の曲率半径ｒを０．５Ｃ〜２．５Ｃ（Ｃは弦長）の範
囲内で変化させた実施例と、受光端面２１が平坦な比較
例について前記各測定点で測定した輝度を、各曲率半径
ごとに平均し、それぞれの比曲率半径（ｒ／Ｃ）におい
て出射面２２全体から出射される帯状光束の平均輝度を
求めた。測定結果を図６に示す。図６の結果から、受光
端面２１を筒形凸レンズ形状に成形した本実施形態の導
光体２０は、受光端面が平坦な従来型の導光体より板状
導光部３０に入射する光の平均輝度が明らかに勝ってお
り、特に０．５ｒ／Ｃ〜１．０ｒ／Ｃの範囲内では従来
型の導光体より１３％以上平均輝度が向上していること
がわかる。(Measurement Example 1: Average emission light brightness) Light receiving end face 2
Luminance measured at each of the measurement points for the example in which the radius of curvature r of 1 is changed within the range of 0.5 C to 2.5 C (C is the chord length) and the comparative example in which the light receiving end face 21 is flat are Averaging was performed for each radius of curvature, and the average luminance of the band-shaped light flux emitted from the entire emission surface 22 was obtained at each specific radius of curvature (r / C). The measurement result is shown in FIG. From the results of FIG. 6, the light guide 20 of the present embodiment in which the light receiving end face 21 is formed in the shape of a cylindrical convex lens shows the light incident on the plate-shaped light guide unit 30 from the conventional light guide having a flat light receiving end face. It can be seen that the average luminance is clearly superior, and particularly in the range of 0.5r / C to 1.0r / C, the average luminance is improved by 13% or more as compared with the conventional light guide.
【００２８】（測定例２：出射光輝度の均一性）受光端
面２１の曲率半径ｒを０．５Ｃ〜２．５Ｃの範囲内で変
化させた実施例と、受光端面２１が平坦な比較例につい
て前記各測定点で出射される光の輝度を測定し、それぞ
れの曲率半径における前記１７の測定点の輝度の内、最
小値（min）と最大値（max）との比（min／max）を計算
し、導光体の長手方向に沿う出射光輝度の均一性の指標
とした。比較例のmin／maxは０．３であった。min／max
値は大きい方が均一性が高い。測定結果を図７に示す。
図７の結果から、受光端面２１を筒形凸レンズ形状に成
形した本実施形態の導光体２０は、受光端面が平坦な従
来型の導光体より導光体の長手方向に沿う出射光輝度の
均一性が明らかに勝っており、部分的な出力ムラが少な
くなっていることがわかる。(Measurement Example 2: Uniformity of Emission Light Luminance) An example in which the radius of curvature r of the light receiving end face 21 is changed within the range of 0.5 C to 2.5 C and a comparative example in which the light receiving end face 21 is flat The brightness of the light emitted at each of the measurement points is measured, and the ratio (min / max) of the minimum value (min) and the maximum value (max) of the brightness of the 17 measurement points at each radius of curvature is measured. It was calculated and used as an index of the uniformity of the emission light brightness along the longitudinal direction of the light guide. The min / max of the comparative example was 0.3. min / max
The larger the value, the higher the uniformity. The measurement result is shown in FIG. 7.
From the results of FIG. 7, the light guide body 20 of the present embodiment in which the light receiving end surface 21 is formed in the shape of a cylindrical convex lens has an output light intensity along the longitudinal direction of the light guide body that is longer than that of the conventional light guide body having a flat light receiving end surface. It can be seen that the uniformity of is clearly superior and the partial output unevenness is reduced.
【００２９】（測定例３：長手方向の出射光輝度均一
性）前記測定例２に関連して、前記１７測定点のそれぞ
れにおける出射光輝度を、本実施形態の一例である曲率
半径ｒが０．６Ｃである導光体と、受光端面が平坦な従
来型の導光体とについて測定した。測定結果を図８に示
す。測定位置は導光体の半長を１として表示した。図８
の結果から、実施形態の場合も比較例の場合も導光体の
中央部に向かって輝度が上昇する傾向は見られるが、実
施形態の場合は比較例に比べ端部と中央部との輝度出力
の差が小さく、帯状光束の全長に亘って輝度の均一性が
改善されていることがわかる。(Measurement Example 3: Uniformity of Emission Light Luminance in the Longitudinal Direction) With reference to the measurement example 2, the emission light brightness at each of the 17 measurement points is 0 when the radius of curvature r, which is an example of this embodiment, is 0. The measurement was performed for a light guide body having a light receiving end surface of 0.6 C and a conventional light guide body having a flat light receiving end surface. The measurement result is shown in FIG. The measurement position is indicated by setting the half length of the light guide as 1. Figure 8
From the results, it can be seen that the luminance tends to increase toward the central portion of the light guide in both the embodiment and the comparative example, but in the case of the embodiment, the luminance at the end portion and the central portion is higher than that in the comparative example. It can be seen that the difference in output is small and the uniformity of luminance is improved over the entire length of the band-shaped light flux.
【００３０】以上説明した測定例１〜測定例３の結果か
ら、受光端面が筒形凸レンズ形状に成形された本実施形
態の導光体は、受光端面が平坦な従来型の導光体より出
射光輝度が向上し、かつ帯状光束全体に亘って輝度の均
一性が改善されていることがわかる。特に筒形凸レンズ
部の曲率半径が弦長の０．５倍〜１．０倍の範囲内のと
きその効果が顕著である。一般に光源からの拡散光の進
路に凸レンズを挿入すれば、拡散する光が収束する結
果、直進光が増大すると予想される。しかし本導光体の
構成においては、導光体内を長手方向に直進する光は反
射面２３で反射されることなく無駄になるので好ましく
ない。本発明はこの予想を覆し、意外にも光の進路に凸
レンズを置くことで出射面２２からの光出力が増大しか
つ帯状光束全体に亘って輝度ムラが改善されることを見
出したことによりもたらされたものである。From the results of the measurement example 1 to the measurement example 3 described above, the light guide of the present embodiment in which the light receiving end surface is formed in the shape of a cylindrical convex lens is out of the conventional light guide body having a flat light receiving end surface. It can be seen that the emitted light brightness is improved and the brightness uniformity is improved over the entire band-shaped light flux. In particular, the effect is remarkable when the radius of curvature of the cylindrical convex lens portion is within the range of 0.5 to 1.0 times the chord length. In general, if a convex lens is inserted in the path of diffused light from the light source, it is expected that the diffused light converges and, as a result, the rectilinear light increases. However, in the configuration of the light guide body, light traveling straight in the longitudinal direction in the light guide body is not reflected by the reflection surface 23 and is wasted, which is not preferable. The present invention overturns this expectation and surprisingly finds that by placing a convex lens in the path of light, the light output from the emission surface 22 is increased and the uneven brightness is improved over the entire band-shaped light flux. It was taken over.
【００３１】（実施形態２）実施形態２の面発光体は、
導光体の受光端面形状が異なる以外は実施形態１と同様
の構成を有する。従ってここでは主として導光体の受光
端面形状について詳しく説明する。図９は、この実施形
態における導光体２０の一方の受光端面付近を示す斜視
図である。図９において、この導光体２０は、実施形態
１の場合と同様に長手方向に延びる４側面のうち、板状
導光部の端面（図示せず）と対向して配置された側面が
光を出射する出射面２２とされ、この出射面２２と対向
する側面が反射面２３とされている。反射面２３には複
数のプリズム状傾斜面２４…が形成されている。このプ
リズム状傾斜面２４…は、実施形態１と同様に何れもそ
の稜線が導光体２０の厚みＴ方向に延びていて、導光体
２０に入射した光を出射面２２側に反射する形状に成形
されている。図示しないが出射面２２を除く導光体の３
方の側面は全て反射膜により覆われている。(Embodiment 2) A surface light emitter according to Embodiment 2 is
It has the same configuration as that of the first embodiment except that the light receiving end face shape of the light guide is different. Therefore, the shape of the light-receiving end face of the light guide will be mainly described in detail here. FIG. 9 is a perspective view showing the vicinity of one light-receiving end surface of the light guide body 20 in this embodiment. In FIG. 9, in the light guide body 20, as in the case of the first embodiment, among the four side surfaces extending in the longitudinal direction, the side surface arranged to face the end surface (not shown) of the plate-shaped light guide portion is a light guide. Is a light emitting surface 22 for emitting light, and a side surface facing the light emitting surface 22 is a reflecting surface 23. A plurality of prismatic inclined surfaces 24 ... Are formed on the reflecting surface 23. As in the first embodiment, the ridges of the prismatic inclined surfaces 24 extend in the thickness T direction of the light guide body 20 and reflect the light incident on the light guide body 20 toward the emission surface 22 side. Is molded into. Although not shown, 3 of the light guide except the exit surface 22
One side surface is entirely covered with a reflective film.
【００３２】導光体２０の受光端面２６は、図示しない
光源部から照射された光を受光する位置に配置されてい
る。実施形態２の受光端面２６は、光源部方向に凸とな
る２条の筒形凸レンズ２６ａ，２６ｂの形状に成形され
ている。この筒形凸レンズ２６ａ，２６ｂは、いずれも
稜線の方向Ｚａ，Ｚｂが導光体２０の厚みＴ方向に延び
ている。筒形凸レンズ２６ａ，２６ｂの曲率半径は同じ
でも異なっていてもよく、それぞれの弦長Ｃ（この場合
弦長Ｃはそれぞれ導光体２０の半幅Ｗ／２とされている
が、互いの弦長は異なっていてもよい）の０．５倍〜
１．０倍の範囲内とされている。The light-receiving end face 26 of the light guide 20 is arranged at a position for receiving light emitted from a light source section (not shown). The light-receiving end surface 26 of the second embodiment is formed in the shape of two cylindrical convex lenses 26a and 26b that are convex in the direction of the light source. In each of the cylindrical convex lenses 26 a and 26 b, the ridgeline directions Za and Zb extend in the thickness T direction of the light guide 20. The radii of curvature of the cylindrical convex lenses 26a and 26b may be the same or different, and the respective chord lengths C (in this case, the chord length C is the half width W / 2 of the light guide 20 respectively, but the chord lengths of the two). May be different) 0.5 times ~
It is within the range of 1.0 times.
【００３３】実施形態２の導光体は、実施形態１の場合
と同様に反射型液晶表示ユニットの表示面上に重ねて点
灯するとき、実施形態１の場合と実質的に同様に明るく
かつ照明ムラのない照明効果が得られた。The light guide according to the second embodiment is substantially bright and illuminating as in the case of the first embodiment when the light guide body is overlapped and lit on the display surface of the reflective liquid crystal display unit as in the first embodiment. An even lighting effect was obtained.
【００３４】（実施形態３）実施形態３の面発光体は、
導光体の受光端面形状が異なる以外は実施形態１と同様
の構成を有する。従ってここでは主として導光体の受光
端面形状について詳しく説明する。図１０は、この実施
形態における導光体２０の一方の受光端面付近を示す斜
視図である。図１０において、この導光体２０は、実施
形態１の場合と同様に長手方向に延びる４側面のうち、
板状導光部の端面（図示せず）と対向して配置された側
面が光を出射する出射面２２とされ、この出射面２２と
対向する側面が反射面２３とされている。(Embodiment 3) The surface light emitter of Embodiment 3 is
It has the same configuration as that of the first embodiment except that the light receiving end face shape of the light guide is different. Therefore, the shape of the light-receiving end face of the light guide will be mainly described in detail here. FIG. 10 is a perspective view showing the vicinity of one light receiving end surface of the light guide body 20 in this embodiment. In FIG. 10, the light guide body 20 has four side surfaces extending in the longitudinal direction, as in the case of the first embodiment.
The side face arranged opposite to the end face (not shown) of the plate-shaped light guide is an emission face 22 for emitting light, and the side face opposite to the emission face 22 is a reflection face 23.
【００３５】導光体２０の受光端面２７は、図示しない
光源部から照射された光を受光する位置に配置されてい
る。実施形態３の受光端面２７は、光源部方向に凸とな
る球面凸レンズの形状に成形されている。この球面凸レ
ンズ形状は、その曲率半径が弦長Ｃ、この場合は導光体
２０の対角線長の０．５倍〜１．０倍の範囲内とされて
いる。The light receiving end face 27 of the light guide 20 is arranged at a position for receiving the light emitted from a light source section (not shown). The light-receiving end surface 27 of the third embodiment is formed in the shape of a spherical convex lens that is convex toward the light source section. The radius of curvature of this spherical convex lens shape is a chord length C, which is in the range of 0.5 times to 1.0 times the diagonal length of the light guide 20 in this case.
【００３６】実施形態３の導光体は、実施形態１の場合
と同様に反射型液晶表示ユニットの表示面上に重ねて点
灯するとき、実施形態１の場合と実質的に同様に明るく
かつ照明ムラのない照明効果が得られた。The light guide according to the third embodiment is substantially bright and illuminating as in the case of the first embodiment when the light guide is turned on by overlapping on the display surface of the reflective liquid crystal display unit as in the first embodiment. An even lighting effect was obtained.
【００３７】（実施形態４）実施形態４の面発光体は、
導光体の受光端面形状が異なる以外は実施形態１と同様
の構成を有する。従ってここでは主として導光体の受光
端面形状について詳しく説明する。図１１は、この実施
形態における導光体２０の受光端面付近を示す平面図で
ある。図１１において、この導光体２０は、実施形態１
の場合と同様に長手方向に延びる４側面のうち、板状導
光部３０の入射側面３１と対向して配置された側面が光
を出射する出射面２２とされ、この出射面２２と対向す
る側面が反射面２３とされている。(Embodiment 4) A surface light emitter according to Embodiment 4 is
It has the same configuration as that of the first embodiment except that the light receiving end face shape of the light guide is different. Therefore, the shape of the light-receiving end face of the light guide will be mainly described in detail here. FIG. 11 is a plan view showing the vicinity of the light receiving end surface of the light guide body 20 in this embodiment. In FIG. 11, this light guide 20 is the same as that of the first embodiment.
Of the four side surfaces extending in the longitudinal direction, the side surface arranged to face the incident side surface 31 of the plate-shaped light guide portion 30 is the emission surface 22 that emits light, and faces the emission surface 22 as in the case of. The side surface is the reflecting surface 23.
【００３８】導光体２０の受光端面２８は、光源部１０
から照射された光を受光する位置に配置されている。実
施形態４の受光端面２８は、光源部１０方向に凸となる
凸プリズムの形状に成形されている。この凸プリズムの
稜線は出射面２２の幅方向に延びている。凸プリズム形
状の底辺を挟む双方の仰角θ，θは同じでも異なっても
よいが、２°〜４０°の範囲内とされている。The light-receiving end face 28 of the light guide 20 is formed by the light source section 10.
It is arranged at a position to receive the light emitted from. The light-receiving end surface 28 of Embodiment 4 is formed in the shape of a convex prism that is convex in the direction of the light source unit 10. The ridgeline of this convex prism extends in the width direction of the emission surface 22. The elevation angles θ, θ on both sides of the base of the convex prism shape may be the same or different, but they are within the range of 2 ° to 40 °.
【００３９】次に本実施形態の面発光体の作用について
図１１を用いて説明する。まず概略の光の経路を説明す
ると、光源部１０から放射されたＬＥＤ光は導光体２０
の受光端面２８から入射し、導光体２０内に導入され
る。導光体２０内に導入された光は反射面２３に成形さ
れた複数のプリズム状傾斜面２４…によって大部分の光
が出射面２２の方向に反射され、出射面２２から、この
面全体が光る帯状光束として出射し、板状導光部３０の
入射側面３１から板状導光部３０内に導入される。板状
導光部３０内に導入された光は対向面３３に成形された
複数のプリズム状傾斜面３４…によって大部分の光は発
光面３２の方向に反射され、発光面３２から、面全体が
光る面状光束として図示しない液晶表示ユニットの表示
面を照射する。Next, the operation of the surface light emitter of this embodiment will be described with reference to FIG. First, a schematic light path will be described. The LED light emitted from the light source unit 10 is guided by the light guide member 20.
The light enters from the light-receiving end surface 28 of the light source and is introduced into the light guide body 20. Most of the light introduced into the light guide body 20 is reflected in the direction of the emission surface 22 by the plurality of prismatic inclined surfaces 24 formed on the reflection surface 23, and from the emission surface 22, the entire surface is reflected. The light is emitted as a shining strip-shaped light flux and is introduced into the plate-shaped light guide portion 30 from the incident side surface 31 of the plate-shaped light guide portion 30. Most of the light introduced into the plate-shaped light guide portion 30 is reflected in the direction of the light emitting surface 32 by the plurality of prism-shaped inclined surfaces 34 formed on the facing surface 33, and the entire surface from the light emitting surface 32 is reflected. Illuminates the display surface of a liquid crystal display unit (not shown) as a planar light beam that shines.
【００４０】液晶表示ユニットの表示面を照射した光の
内、液晶層において液晶分子の配向によって遮光される
ことなく透過した光は反射層に達し、この反射層によっ
て反射され、再び液晶表示板を透過し、更に板状導光部
３０を透過して直進し、対向面３３から外部に放射され
視認されることになる。この板状導光部３０は、導光体
から光が入射する入射側面３１以外の側面や上下の板面
は、外光や光源光の余分な反射や散乱に起因するヘイズ
やグレアを防止し画像コントラストを高めるために反射
防止膜が施されていてもよい。Of the light that illuminates the display surface of the liquid crystal display unit, the light that has passed through the liquid crystal layer without being blocked by the alignment of the liquid crystal molecules reaches the reflective layer, is reflected by this reflective layer, and is again displayed on the liquid crystal display plate. The light passes through the plate-shaped light guide portion 30, goes straight ahead, is radiated to the outside from the facing surface 33, and is visually recognized. The plate-shaped light guide section 30 prevents haze and glare caused by extra reflection and scattering of outside light and light from the light source on the side surfaces other than the incident side surface 31 on which light is incident from the light guide body and the upper and lower plate surfaces. An antireflection film may be applied to enhance the image contrast.
【００４１】前記実施形態の導光体において、導光体の
受光端面２７の仰角θを種々変化させた試作品を作成
し、出射面２２から帯状光束として出射する光の輝度を
測定した。ただし凸プリズム形状の双方の仰角θ，θは
等しくした。輝度の測定は、実施形態１の場合と同様に
出射面２２の長手方向に一方の端部から中央線Ｘ−Ｘま
での長さ（半長）を１７等分してそれぞれを測定点と
し、各測定点において、垂直線から出射面２２の長手方
向に±２０°の範囲内で測定視野を振って輝度を測定
し、その平均値を測定点における輝度とした。In the light guide of the above-described embodiment, prototypes were produced in which the elevation angle θ of the light receiving end face 27 of the light guide was variously changed, and the brightness of light emitted as a band-shaped light flux from the emission surface 22 was measured. However, both elevation angles θ and θ of the convex prism shape were made equal. In the measurement of the luminance, as in the case of the first embodiment, the length (half length) from one end to the center line XX in the longitudinal direction of the emission surface 22 is divided into 17 equal parts, and the respective measurement points are obtained. At each measurement point, the measurement visual field was swung within the range of ± 20 ° from the vertical line in the longitudinal direction of the emission surface 22 to measure the luminance, and the average value thereof was taken as the luminance at the measurement point.
【００４２】（測定例５：平均出射光輝度）受光端面２
８の仰角θを０°〜５０°の範囲内で変化させ、前記各
測定点で出力される出射光輝度を測定し、更に各仰角ご
とに前記輝度の平均値を計算し、それぞれの仰角におい
て出射面２２全体から出射される帯状光束の平均輝度を
求めた。比較例は仰角θが０°の平坦面の場合である。
測定結果を図１２に示す。図１２の結果から、受光端面
２８を凸プリズム形状に成形した本実施形態の導光体
は、受光端面が平坦な従来型の導光体より板状導光部３
０に入射する光の平均輝度が勝っており、特に２°〜４
０°の範囲内では従来型の導光体より明らかに平均の出
射光輝度が向上していることがわかる。特に仰角が２０
°〜３０°の範囲内では従来型の導光体より１３％も平
均出射光輝度が向上している。(Measurement Example 5: Average outgoing light brightness) Light receiving end face 2
The elevation angle θ of 8 is changed within the range of 0 ° to 50 °, the emission light luminance output at each measurement point is measured, and the average value of the luminance is calculated for each elevation angle. The average luminance of the band-shaped light flux emitted from the entire emission surface 22 was obtained. The comparative example is a case of a flat surface having an elevation angle θ of 0 °.
The measurement result is shown in FIG. From the result of FIG. 12, the light guide body of the present embodiment in which the light receiving end surface 28 is formed in the shape of a convex prism has a plate-shaped light guide portion 3 more than the conventional light guide body having a flat light receiving end surface.
The average brightness of the light incident on 0 is superior, especially 2 ° to 4
It can be seen that in the range of 0 °, the average output light brightness is obviously improved as compared with the conventional light guide. Especially elevation angle 20
In the range of 30 ° to 30 °, the average output light brightness is improved by 13% over the conventional light guide.
【００４３】（測定例６：輝度の均一性）受光端面２８
の仰角θを２°〜５０°の範囲内で変化させた実施例
と、受光端面が平坦な比較例（θ＝０°）について前記
各測定点で出射される光の輝度を測定し、それぞれの仰
角θにおける前記１７の測定点の輝度の内、最小値（mi
n）と最大値（max）との比（min／max）を計算し、導光
体の長手方向に沿う出射光輝度の均一性の指標とした。
比較例のmin／maxは０．３であった。min／max値は大き
い方が均一性が高い。測定結果を図１３に示す。図１３
の結果から、受光端面２８をプリズム状に成形した本実
施形態の導光体は、受光端面が平坦な従来型の導光体よ
り導光体の長手方向に沿う出射光輝度の均一性が勝って
おり、部分的な出力ムラが少なくなっていることがわか
る。(Measurement Example 6: Uniformity of luminance) Light receiving end face 28
The brightness of the light emitted at each of the measurement points was measured for an example in which the elevation angle θ of the light source was changed within the range of 2 ° to 50 ° and for a comparative example in which the light receiving end surface was flat (θ = 0 °). Of the 17 measurement points at the elevation angle θ of
The ratio (min / max) between n) and the maximum value (max) was calculated and used as an index of the uniformity of emission light brightness along the longitudinal direction of the light guide.
The min / max of the comparative example was 0.3. The larger the min / max value, the higher the uniformity. The measurement result is shown in FIG. FIG.
From the results, the light guide of the present embodiment in which the light receiving end face 28 is formed in a prism shape is superior in the uniformity of the emission light intensity along the longitudinal direction of the light guide to the conventional light guide having a flat light receiving end face. It can be seen that the partial output unevenness is reduced.
【００４４】（測定例７：長手方向の出射光輝度均一
性）前記測定例６に関連して、前記１７測定点のそれぞ
れにおける出射光輝度を、本実施形態の一例である端面
プリズムの仰角が３０°である導光体と、受光端面が平
坦な従来型の導光体とについて測定した。測定結果を図
１４に示す。測定位置は導光体の半長を１として表示し
た。図１４の結果から、比較例の場合は導光体の中央部
に向かって輝度が漸次上昇する傾向が見られる。これに
対して本実施形態の場合は端部と中央部の輝度が高く中
間部では輝度が低下して比較例と同程度になるが全域を
通して出射光輝度の差が小さく、帯状光束の全長に亘っ
て輝度の均一性が改善されていることがわかる。(Measurement Example 7: Uniformity of Luminance of Emitted Light in Longitudinal Direction) With reference to the sixth measurement example, the radiance of emitted light at each of the 17 measurement points is determined by the elevation angle of the end face prism which is an example of this embodiment. The measurement was performed on a light guide having an angle of 30 ° and a conventional light guide having a flat light receiving end surface. The measurement result is shown in FIG. The measurement position is indicated by setting the half length of the light guide as 1. From the result of FIG. 14, in the case of the comparative example, there is a tendency that the luminance gradually increases toward the central portion of the light guide. On the other hand, in the case of the present embodiment, the brightness at the end and the central part is high and the brightness at the intermediate part is low, and is about the same as in the comparative example, but the difference in the brightness of the emitted light is small throughout the entire area, and the total length of the band-shaped light flux is It can be seen that the brightness uniformity is improved over the entire range.
【００４５】以上説明した測定例５〜測定例７の結果か
ら、導光体の受光端面をプリズム形状に成形した本実施
形態の導光体は、受光端面が平坦な従来型の導光体より
出射光輝度が向上し、かつ帯状光束全体に亘って出射光
輝度の均一性が改善されていることがわかる。特に仰角
が２°〜４０°の範囲内のときその効果が顕著であっ
た。From the results of the measurement example 5 to the measurement example 7 described above, the light guide body of the present embodiment in which the light receiving end surface of the light guide body is formed into a prism shape is better than the conventional light guide body having a flat light receiving end surface. It can be seen that the brightness of the emitted light is improved and the uniformity of the brightness of the emitted light is improved over the entire band-shaped light flux. The effect was particularly remarkable when the elevation angle was in the range of 2 ° to 40 °.
【００４６】（実施形態５）実施形態５の面発光体は、
導光体の受光端面形状が異なる以外は実施形態１と同様
の構成を有する。従ってここでは主として導光体の受光
端面形状について詳しく説明する。図１５は、この実施
形態における導光体２０の受光端面付近を示す平面図で
ある。図１５において、この導光体２０は、実施形態１
の場合と同様に長手方向に延びる４側面のうち、板状導
光部３０の受光端面３１と対向して配置された側面が出
射面２２とされ、この出射面２２と対向する側面が反射
面２３とされている。反射面２３には複数のプリズム状
傾斜面２４…が形成されている。(Embodiment 5) A surface light emitter according to Embodiment 5 is
It has the same configuration as that of the first embodiment except that the light receiving end face shape of the light guide is different. Therefore, the shape of the light-receiving end face of the light guide will be mainly described in detail here. FIG. 15 is a plan view showing the vicinity of the light receiving end surface of the light guide body 20 in this embodiment. In FIG. 15, the light guide 20 is the same as that of the first embodiment.
Of the four side surfaces extending in the longitudinal direction, the side surface arranged facing the light receiving end surface 31 of the plate-shaped light guide portion 30 is the emitting surface 22, and the side surface facing the emitting surface 22 is the reflecting surface. It is said to be 23. A plurality of prismatic inclined surfaces 24 ... Are formed on the reflecting surface 23.
【００４７】導光体２０の受光端面２９は、光源部１０
から照射された光を受光する位置に配置されている。実
施形態５の受光端面２９は、光源部１０方向に凸となる
２条の凸プリズム形状２９ａ，２９ｂに成形されてい
る。この凸プリズム形状２９ａ，２９ｂは、いずれも稜
線の方向が導光体２０の厚み方向に延びている。凸プリ
ズム形状２９ａ，２９ｂの各仰角はそれぞれが同じでも
異なっていてもよいが、いずれも２°〜４０°の範囲内
とされている。The light-receiving end face 29 of the light guide 20 is formed by the light source unit 10.
It is arranged at a position to receive the light emitted from. The light receiving end surface 29 of the fifth embodiment is formed into two convex prism shapes 29a and 29b that are convex toward the light source unit 10. In each of the convex prism shapes 29a and 29b, the direction of the ridge line extends in the thickness direction of the light guide 20. The elevation angles of the convex prism shapes 29a and 29b may be the same or different, but both are within the range of 2 ° to 40 °.
【００４８】実施形態５の面発光体は、実施形態１の場
合と同様に反射型液晶表示ユニットの表示面上に重ねて
点灯するとき、実施形態１の場合と実質的に同様に明る
くかつ照明ムラのない照明効果が得られた。The surface light emitter according to the fifth embodiment is substantially bright and illuminating as in the case of the first embodiment when the surface light emitter is overlapped and lit on the display surface of the reflective liquid crystal display unit as in the first embodiment. An even lighting effect was obtained.
【００４９】（実施形態６）実施形態６の面発光体は、
導光体の受光端面形状が異なる以外は実施形態１と同様
の構成を有する。従ってここでは主として導光体の受光
端面形状について詳しく説明する。図１６は、この実施
形態における導光体２０の受光端面付近を示す平面図で
ある。図９において、この導光体２０は、実施形態１の
場合と同様に長手方向に延びる４側面のうち、板状導光
部３０の受光端面３１と対向して配置された側面が出射
面２２とされ、この出射面２２と対向する側面が反射面
２３とされている。(Embodiment 6) A surface light emitter according to Embodiment 6 is
It has the same configuration as that of the first embodiment except that the light receiving end face shape of the light guide is different. Therefore, the shape of the light-receiving end face of the light guide will be mainly described in detail here. FIG. 16 is a plan view showing the vicinity of the light receiving end surface of the light guide body 20 in this embodiment. In FIG. 9, in the light guide body 20, as in the case of the first embodiment, among the four side surfaces extending in the longitudinal direction, the side surface arranged facing the light receiving end surface 31 of the plate-shaped light guide portion 30 is the emitting surface 22. The side surface facing the emission surface 22 is a reflection surface 23.
【００５０】導光体２０の受光端面４０は、光源部１０
から照射された光を受光する位置に配置されている。実
施形態６の受光端面４０は、４分割筒形凸レンズの形状
を有するレンズ部４０ａと片側傾斜面の形状を有するプ
リズム部４０ｂとが合体して１条の凸面が形成された複
合型凸面形状となっている。ここで「４分割筒形凸レン
ズ部」とは、円柱を軸心に沿って４等分した形状であ
る。レンズ部４０ａとプリズム部４０ｂとが合体して形
成される凸面の稜線は導光体２０の厚み方向（すなわち
幅Ｗに対して垂直方向）に延びている。試作した導光体
６Ａ，６Ｂ，６Ｃの受光端面におけるレンズ部４０ａの
曲率半径ｒとプリズム部４０ｂの底辺長さＬとの関係
を、導光体２０の幅Ｗに対する比として図１６に表示し
た。The light-receiving end face 40 of the light guide 20 is formed by the light source unit 10.
It is arranged at a position to receive the light emitted from. The light-receiving end surface 40 of the sixth embodiment has a complex convex surface shape in which a lens portion 40a having the shape of a four-divided cylindrical convex lens and a prism portion 40b having the shape of an inclined surface on one side are combined to form a single convex surface. Has become. Here, the “four-divided cylindrical convex lens portion” has a shape obtained by dividing a cylinder into four equal parts along the axis. The ridgeline of the convex surface formed by combining the lens portion 40a and the prism portion 40b extends in the thickness direction of the light guide body 20 (that is, the direction perpendicular to the width W). The relationship between the radius of curvature r of the lens portion 40a and the base length L of the prism portion 40b at the light-receiving end faces of the trial light guides 6A, 6B, and 6C is shown in FIG. 16 as a ratio to the width W of the light guide 20. .
【００５１】実施形態６の面発光体は、導光体の受光端
面の形状が図１６に示す６Ａ，６Ｂ，６Ｃの何れであっ
ても、反射型液晶表示ユニットの表示面上に重ねて点灯
するとき、実施形態１の場合と実質的に同様に明るくか
つ照明ムラのない照明効果が得られた。In the surface light emitter of the sixth embodiment, the light-receiving end face of the light guide body is any of 6A, 6B and 6C shown in FIG. 16, and the light is superposed on the display surface of the reflection type liquid crystal display unit. In doing so, a lighting effect that was bright and had no unevenness of illumination was obtained substantially similarly to the case of the first embodiment.
【００５２】（実施形態７）実施形態７の面発光体は、
導光体の受光端面形状が異なる以外は実施形態１と同様
の構成を有する。従ってここでは主として導光体の受光
端面形状について詳しく説明する。図１７は、この実施
形態における導光体２０の受光端面付近を示す平面図で
ある。図１７において、この導光体２０は、実施形態６
の場合と同様に長手方向に延びる４側面のうち、板状導
光部３０の受光端面３１と対向して配置された側面が出
射面２２とされ、この出射面２２と対向する側面が反射
面２３とされている。(Embodiment 7) A surface light emitter according to Embodiment 7 is
It has the same configuration as that of the first embodiment except that the light receiving end face shape of the light guide is different. Therefore, the shape of the light-receiving end face of the light guide will be mainly described in detail here. FIG. 17 is a plan view showing the vicinity of the light receiving end surface of the light guide body 20 in this embodiment. In FIG. 17, this light guide 20 is the same as that of the sixth embodiment.
Of the four side surfaces extending in the longitudinal direction, the side surface arranged facing the light receiving end surface 31 of the plate-shaped light guide portion 30 is the emitting surface 22, and the side surface facing the emitting surface 22 is the reflecting surface. It is said to be 23.
【００５３】導光体２０の受光端面４１は、光源部１０
から照射された光を受光する位置に配置されている。実
施形態７の受光端面４１は、実施形態６と同様に４分割
筒形凸レンズの形状を有するレンズ部４１ａと片側傾斜
面の形状を有するプリズム部４１ｂとが合体して１条の
凸面が形成された複合型凸面形状となっている。ただし
レンズ部４１ａとプリズム部４１ｂとの板状導光部３０
に向かっての配列順序が実施形態６の場合とは逆になっ
ている。すなわちレンズ部４１ａが板状導光部３０側に
配置されている。試作した導光体７Ａ，７Ｂ，７Ｃの受
光端面におけるレンズ部４１ａの曲率半径ｒとプリズム
部４１ｂの底辺長さＬとの関係を、導光体２０の幅Ｗに
対する比として図１７に表示した。The light receiving end surface 41 of the light guide body 20 has the light source section 10
It is arranged at a position to receive the light emitted from. As in the sixth embodiment, the light receiving end surface 41 of the seventh embodiment has a single convex surface formed by combining the lens portion 41a having the shape of a four-divided cylindrical convex lens and the prism portion 41b having the shape of the one-side inclined surface. It has a complex convex shape. However, the plate-shaped light guide portion 30 including the lens portion 41a and the prism portion 41b
The arrangement order toward is opposite to that in the sixth embodiment. That is, the lens portion 41a is arranged on the plate-shaped light guide portion 30 side. The relationship between the radius of curvature r of the lens portion 41a and the base length L of the prism portion 41b at the light-receiving end faces of the light guides 7A, 7B, and 7C that were prototyped is shown in FIG. 17 as a ratio to the width W of the light guide 20. .
【００５４】実施形態７の面発光体は、導光体の受光端
面の形状が図１７に示す７Ａ，７Ｂ，７Ｃの何れであっ
ても、反射型液晶表示ユニットの表示面上に重ねて点灯
するとき、実施形態１の場合と実質的に同様に明るくか
つ照明ムラのない照明効果が得られた。In the surface light emitter of the seventh embodiment, the light receiving end surface of the light guide body is any of 7A, 7B, and 7C shown in FIG. 17, and the light is superposed on the display surface of the reflection type liquid crystal display unit. In doing so, a lighting effect that was bright and had no unevenness of illumination was obtained substantially similarly to the case of the first embodiment.
【００５５】（実施形態８）実施形態８の面発光体は、
導光体の受光端面形状が異なる以外は実施形態１と同様
の構成を有する。従ってここでは主として導光体の受光
端面形状について詳しく説明する。図１８（ａ）は、こ
の実施形態における導光体２０の受光端面付近を示す平
面図である。図１８（ａ）において、この導光体２０
は、実施形態１の場合と同様に長手方向に延びる４側面
のうち、板状導光部３０の受光端面３１と対向して配置
された側面が出射面２２とされ、この出射面２２と対向
する側面が反射面２３とされている。(Embodiment 8) A surface light emitter according to Embodiment 8 is
It has the same configuration as that of the first embodiment except that the light receiving end face shape of the light guide is different. Therefore, the shape of the light-receiving end face of the light guide will be mainly described in detail here. FIG. 18A is a plan view showing the vicinity of the light receiving end surface of the light guide body 20 in this embodiment. In FIG. 18A, this light guide 20
Of the four side surfaces extending in the longitudinal direction as in the case of the first embodiment, the side surface arranged facing the light receiving end surface 31 of the plate-shaped light guide portion 30 is the emission surface 22, and the side opposite to the emission surface 22. The side surface to be formed is the reflecting surface 23.
【００５６】導光体２０の受光端面４２は、光源部１０
から照射された光を受光する位置に配置されている。実
施形態８の受光端面４２は、４分割筒形凸レンズの形状
を有するレンズ部４２ａと片側傾斜面の形状を有するプ
リズム部４２ｂとが合体して１条の凸面を形成し、この
複合型凸面形状がプリズム部４２ｂ，４２ｂを内側にし
て対称的に２条配列されている。いずれも稜線の方向は
導光体２０の厚み方向（すなわち幅Ｗに対して垂直方
向）に延びている。The light-receiving end surface 42 of the light guide 20 is formed by the light source section 10.
It is arranged at a position to receive the light emitted from. In the light receiving end surface 42 of the eighth embodiment, the lens portion 42a having the shape of a four-divided cylindrical convex lens and the prism portion 42b having the shape of the one-side inclined surface are combined to form a single convex surface. Are symmetrically arranged in two rows with the prism portions 42b, 42b inside. In both cases, the direction of the ridge extends in the thickness direction of the light guide body 20 (that is, the direction perpendicular to the width W).
【００５７】図１８（ａ）に示した受光端面４２の配列
順序は、板状導光部３０の側から［レンズ部４２ａ−プ
リズム部４２ｂ−プリズム部４２ｂ−レンズ部４２ａ］
となっている。試作例として、図１８（ｂ）〜図１８
（ｄ）に示すようにそれぞれレンズ部４２ａとプリズム
部４２ｂとの配列順序を変更し、ただし必ずレンズ部４
２ａとプリズム部４２ｂとが組合わされて１条の凸面を
形成するようにして導光体を作成した。図番と前記組合
わせとの関係を以下に示す。
図１８（ｂ）：［レンズ部４２ａ−プリズム部４２ｂ−
レンズ部４２ａ−プリズム部４２ｂ］
図１８（ｃ）：［プリズム部４２ｂ−レンズ部４２ａ−
レンズ部４２ａ−プリズム部４２ｂ］
図１８（ｄ）：［プリズム部４２ｂ−レンズ部４２ａ−
プリズム部４２ｂ−レンズ部４２ａ］The arrangement order of the light-receiving end faces 42 shown in FIG. 18A is from the side of the plate-shaped light guide 30 [lens part 42a-prism part 42b-prism part 42b-lens part 42a].
Has become. As an example of trial manufacture, FIG.
As shown in (d), the arrangement order of the lens portion 42a and the prism portion 42b is changed, but the lens portion 4a
The light guide was prepared by combining 2a and the prism portion 42b to form a single convex surface. The relationship between the drawing number and the combination is shown below. FIG. 18B: [Lens 42a-Prism 42b-
Lens part 42a-prism part 42b] Fig. 18 (c): [prism part 42b-lens part 42a-
Lens part 42a-prism part 42b] Fig. 18 (d): [prism part 42b-lens part 42a-
Prism 42b-Lens 42a]
【００５８】実施形態８の面発光体は、図１８（ａ）〜
図１８（ｄ）に示す何れの組合わせのものも、反射型液
晶表示ユニットの表示面上に重ねて点灯するとき、実施
形態１の場合と実質的に同様に明るくかつ照明ムラのな
い照明効果が得られた。The surface-emitting body of the eighth embodiment is shown in FIGS.
In any combination shown in FIG. 18D, when lighting is performed by overlapping on the display surface of the reflective liquid crystal display unit, the lighting effect is substantially the same as in the case of the first embodiment, and is bright and has no uneven illumination. was gotten.
【００５９】[0059]
【発明の効果】本発明の導光体は、受光端面から入射し
た光を出射面から帯状光束として出射するように構成さ
れ、前記受光端面が凸面形状に成形されているので、端
面が平坦な従来の導光体に比べ、出射面から出射される
帯状光束の輝度および均一性が向上している。本発明の
面発光体は、前記本発明の導光体と板状導光部とを有
し、前記板状導光部が、前記導光体から出射された帯状
光束を入射側面から受光し、板面から面状光束として出
射するように構成されているので、端面が平坦な導光体
を用いた従来の面発光体に比べ、板状導光部の板面から
出射される面状光束の輝度および均一性が向上してい
る。本発明の液晶表示装置は、前記本発明の面発光体と
液晶表示ユニットとを備えているので、従来の面発光体
を用いたものに比べ、表示画像が明るく、かつ明るさの
均一性が向上している。The light guide of the present invention is constructed so that the light incident from the light receiving end face is emitted from the emitting face as a band-shaped light beam, and the light receiving end face is formed in a convex shape, so that the end face is flat. Compared with the conventional light guide, the brightness and the uniformity of the band-shaped light flux emitted from the emission surface are improved. A surface light emitter of the present invention has the light guide of the present invention and a plate-shaped light guide unit, and the plate-shaped light guide unit receives a band-shaped light flux emitted from the light guide from an incident side surface. Since it is configured to emit as a planar light flux from the plate surface, the planar shape emitted from the plate surface of the plate-shaped light guide unit is different from that of the conventional surface light emitter using the light guide body having a flat end surface. The brightness and uniformity of the luminous flux are improved. Since the liquid crystal display device of the present invention includes the surface light emitter of the present invention and the liquid crystal display unit, the display image is brighter and the brightness is more uniform than that using the conventional surface light emitter. Has improved.
【図１】 本発明の実施形態１の面発光体を示す平面図
である。FIG. 1 is a plan view showing a surface light emitter according to a first embodiment of the present invention.
【図２】 前記実施形態の導光体の端部近辺を示す斜視
図である。FIG. 2 is a perspective view showing the vicinity of an end portion of the light guide body of the embodiment.
【図３】 前記実施形態の面発光体と液晶表示ユニット
とを組合わせて構成した本発明の液晶表示装置の一例を
示す断面図である。FIG. 3 is a cross-sectional view showing an example of a liquid crystal display device of the present invention, which is configured by combining the surface light emitter of the embodiment and a liquid crystal display unit.
【図４】 前記液晶表示装置に用いられる反射層の一例
を示す斜視図である。FIG. 4 is a perspective view showing an example of a reflective layer used in the liquid crystal display device.
【図５】 導光体の出射面から出射される出射光の輝度
を測定する方法を示す平面図である。FIG. 5 is a plan view showing a method for measuring the brightness of outgoing light emitted from the outgoing surface of the light guide.
【図６】 平均出射光輝度の測定結果を示すグラフであ
る。FIG. 6 is a graph showing a measurement result of average emission light brightness.
【図７】 出射光輝度の均一性の測定結果を示すグラフ
である。FIG. 7 is a graph showing a measurement result of uniformity of emitted light brightness.
【図８】 導光体の長手方向の出射光輝度均一性の測定
結果を示すグラフである。FIG. 8 is a graph showing a measurement result of luminance uniformity of emitted light in a longitudinal direction of a light guide.
【図９】 実施形態２における導光体の受光端面付近を
示す斜視図である。FIG. 9 is a perspective view showing the vicinity of a light receiving end surface of a light guide according to the second embodiment.
【図１０】 実施形態３における導光体の受光端面付近
を示す斜視図である。FIG. 10 is a perspective view showing the vicinity of a light receiving end surface of a light guide according to a third embodiment.
【図１１】 実施形態４における導光体の受光端面付近
を示す平面図である。FIG. 11 is a plan view showing the vicinity of a light receiving end surface of a light guide according to a fourth embodiment.
【図１２】 平均出射光輝度の測定結果を示すグラフで
ある。FIG. 12 is a graph showing the measurement results of average output light luminance.
【図１３】 出射光輝度の均一性の測定結果を示すグラ
フである。FIG. 13 is a graph showing the measurement results of the uniformity of emitted light brightness.
【図１４】 導光体の長手方向の出射光輝度均一性の測
定結果を示すグラフである。FIG. 14 is a graph showing a measurement result of luminance uniformity of outgoing light in the longitudinal direction of the light guide.
【図１５】 実施形態５における導光体の受光端面付近
を示す平面図である。FIG. 15 is a plan view showing the vicinity of a light receiving end surface of a light guide according to a fifth embodiment.
【図１６】 実施形態６における導光体２０の受光端面
付近を示す平面図である。FIG. 16 is a plan view showing the vicinity of a light receiving end surface of a light guide body 20 according to the sixth embodiment.
【図１７】 実施形態７における導光体の受光端面付近
を示す平面図である。FIG. 17 is a plan view showing the vicinity of a light receiving end surface of a light guide according to a seventh embodiment.
【図１８】 （ａ）〜（ｄ）は何れも、実施形態８にお
ける導光体の受光端面付近を示す平面図である。18A to 18D are plan views showing the vicinity of the light-receiving end surface of the light guide according to the eighth embodiment.
【図１９】 従来から用いられている液晶表示装置の一
例を示す斜視図である。FIG. 19 is a perspective view showing an example of a conventionally used liquid crystal display device.
【図２０】 （ａ）は前記従来の液晶表示装置の一部を
表示面側から見た平面図、（ｂ）はその線Ｘ−Ｘで切っ
た断面図である。20A is a plan view of a part of the conventional liquid crystal display device seen from the display surface side, and FIG. 20B is a sectional view taken along line XX thereof.
１０…光源部、２０…導光体、２１…受光端面、２２…
出射面、２３…反射面、３０…板状導光部、３１…入射
側面、３２…発光面、３３…対向面、５０…液晶表示ユ
ニット、５１…液晶表示板、５２…反射層。10 ... Light source part, 20 ... Light guide, 21 ... Light receiving end surface, 22 ...
Emitting surface, 23 ... Reflecting surface, 30 ... Plate-shaped light guide portion, 31 ... Incident side surface, 32 ... Light emitting surface, 33 ... Opposing surface, 50 ... Liquid crystal display unit, 51 ... Liquid crystal display plate, 52 ... Reflective layer.
───────────────────────────────────────────────────── 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 101:02 Ｆ２１Ｙ 101:02 Ｆターム(参考） 2H038 AA52 AA55 BA06 2H091 FA23X FA26X FA45X FB02 FC17 FD06 GA02 LA18 ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) // F21Y 101: 02 F21Y 101: 02 F term (reference) 2H038 AA52 AA55 BA06 2H091 FA23X FA26X FA45X FB02 FC17 FD06 GA02 LA18
Claims (12)
面（出射面）から帯状光束として出射するように構成さ
れた柱状の導光体であって、 前記光を受光する端面（受光端面）が凸面形状に成形さ
れたことを特徴とする導光体。1. A columnar light guide body configured to emit light incident from an end face as a band-shaped light flux from a side face (emission face) along the longitudinal direction, the end face receiving the light (light receiving end face). Is formed into a convex shape.
方向に延びる１以上の筒形凸レンズの形状に成形された
ことを特徴とする請求項１に記載の導光体。2. The light guide according to claim 1, wherein the light-receiving end surface is formed into one or more cylindrical convex lenses whose ridge lines extend in the width direction of the emission surface.
該形状の弦長の０．５倍〜１．０倍の範囲内とされたこ
とを特徴とする請求項２に記載の導光体。3. The light guide according to claim 2, wherein the radius of curvature of the cylindrical convex lens shape is within a range of 0.5 times to 1.0 times the chord length of the shape. .
の形状に成形されたことを特徴とする請求項１に記載の
導光体。4. The light guide according to claim 1, wherein the light-receiving end face is formed in the shape of one or more spherical convex lenses.
該形状の弦長の０．５倍〜１．０倍の範囲内とされたこ
とを特徴とする請求項４に記載の導光体。5. The light guide according to claim 4, wherein the radius of curvature of the spherical convex lens shape is within a range of 0.5 times to 1.0 times the chord length of the shape.
方向に延びる１以上の凸プリズムの形状に成形されたこ
とを特徴とする請求項１に記載の導光体。6. The light guide according to claim 1, wherein the light-receiving end face is formed in the shape of one or more convex prisms whose ridge lines extend in the width direction of the emission face.
は、２°〜４０°の範囲内とされたことを特徴とする請
求項６に記載の導光体。7. The light guide according to claim 6, wherein an elevation angle sandwiching the base of the convex prism shape is within a range of 2 ° to 40 °.
方向に延びる４分割筒形凸レンズ部と、前記稜線を共有
する片側傾斜面のプリズム部とからなる１以上の複合型
凸面形状に成形されたことを特徴とする請求項１に記載
の導光体。8. The light-receiving end surface has one or more composite convex shapes, each of which is composed of a four-divided cylindrical convex lens portion having a ridgeline extending in the width direction of the emission surface and a prism portion having a one-side inclined surface sharing the ridgeline. The light guide according to claim 1, wherein the light guide is molded.
端面から入射した光を前記出射面方向に反射する反射手
段が設けられたことを特徴とする請求項１〜請求項８の
何れかに記載の導光体。9. The reflecting means for reflecting the light incident from the light-receiving end surface toward the emission surface is provided on the side surface facing the emission surface. The light guide according to.
導光体と板状導光部とを有し、 前記板状導光部は、前記導光体から出射した前記帯状光
束を側面（入射側面）で受光し、板面から面状光束とし
て出射するように構成されたことを特徴とする面発光
体。10. The light guide according to any one of claims 1 to 9 and a plate-shaped light guide section, wherein the plate-shaped light guide section is the band-shaped light flux emitted from the light guide. Is received by a side surface (incident side surface) and is emitted as a planar light beam from a plate surface.
光透過性であり、かつ前記入射側面から入射した前記帯
状光束を一方の板面（発光面）から面状光束として出射
する反射手段が設けられたことを特徴とする請求項１０
に記載の面発光体。11. The plate-shaped light guide section is light-transmissive in a direction perpendicular to a plate surface, and emits the band-shaped light beam incident from the incident side surface as a surface light beam from one plate surface (light emitting surface). 11. A reflecting means is provided for controlling the reflection.
The surface-emitting body according to.
面発光体と液晶表示ユニットとを備えたことを特徴とす
る液晶表示装置。12. A liquid crystal display device comprising the surface light emitter according to claim 10 and a liquid crystal display unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001363360A JP3889958B2 (en) | 2001-11-28 | 2001-11-28 | Surface light emitter and liquid crystal display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001363360A JP3889958B2 (en) | 2001-11-28 | 2001-11-28 | Surface light emitter and liquid crystal display device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003161839A true JP2003161839A (en) | 2003-06-06 |
| JP3889958B2 JP3889958B2 (en) | 2007-03-07 |
Family
ID=19173717
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001363360A Expired - Fee Related JP3889958B2 (en) | 2001-11-28 | 2001-11-28 | Surface light emitter and liquid crystal display device |
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| Country | Link |
|---|---|
| JP (1) | JP3889958B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009117270A (en) * | 2007-11-09 | 2009-05-28 | Kanto Auto Works Ltd | Lamp for vehicle, and manufacturing method thereof |
| WO2010098036A1 (en) * | 2009-02-24 | 2010-09-02 | 日東光学株式会社 | Light emitting device and light emitting element |
| JP2011003476A (en) * | 2009-06-19 | 2011-01-06 | Nittoh Kogaku Kk | Light-emitting device and optical element |
| JP2013502692A (en) * | 2009-08-21 | 2013-01-24 | マイクロソフト コーポレーション | Concentrator for illumination optics |
-
2001
- 2001-11-28 JP JP2001363360A patent/JP3889958B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009117270A (en) * | 2007-11-09 | 2009-05-28 | Kanto Auto Works Ltd | Lamp for vehicle, and manufacturing method thereof |
| WO2010098036A1 (en) * | 2009-02-24 | 2010-09-02 | 日東光学株式会社 | Light emitting device and light emitting element |
| JP2010198851A (en) * | 2009-02-24 | 2010-09-09 | Nittoh Kogaku Kk | Light-emitting device and optical element |
| US8727591B2 (en) | 2009-02-24 | 2014-05-20 | Nittoh Kogaku K.K. | Light emitting device and optical element |
| JP2011003476A (en) * | 2009-06-19 | 2011-01-06 | Nittoh Kogaku Kk | Light-emitting device and optical element |
| JP2013502692A (en) * | 2009-08-21 | 2013-01-24 | マイクロソフト コーポレーション | Concentrator for illumination optics |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3889958B2 (en) | 2007-03-07 |
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