JPH09152604A - Planar light emitting device - Google Patents
Planar light emitting deviceInfo
- Publication number
- JPH09152604A JPH09152604A JP7312459A JP31245995A JPH09152604A JP H09152604 A JPH09152604 A JP H09152604A JP 7312459 A JP7312459 A JP 7312459A JP 31245995 A JP31245995 A JP 31245995A JP H09152604 A JPH09152604 A JP H09152604A
- Authority
- JP
- Japan
- Prior art keywords
- light
- guide plate
- light guide
- polarized light
- incident
- 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
- Polarising Elements (AREA)
- Liquid Crystal (AREA)
- Planar Illumination Modules (AREA)
Abstract
(57)【要約】
【課題】 偏光分離の精度を高め、光を有効に利用する
ことにより、輝度が高く、しかも画質感に優れた面状発
光装置を提供する。
【解決手段】屈折率が互いに異なる二つの媒質が隣接し
てなる導光板と、この導光板の入射面近傍に配置された
線状の光源と、この導光板の入射面とは反対側の端面近
傍に配置された１／４波長板と、この１／４波長板の外
側に配置された第１の反射板と、導光板の出射面とは反
対の面近傍に配置された第２の反射板とを備え、導光板
を構成する一方の媒質が薄膜状のチップからなり、この
チップが入射光の進行方向に対して傾斜した状態で、も
う一方の媒質中に均一に分散されている。
(57) An object of the present invention is to provide a planar light emitting device which has high brightness and high image quality by improving the accuracy of polarized light separation and effectively utilizing light. SOLUTION: A light guide plate in which two media having different refractive indexes are adjacent to each other, a linear light source arranged in the vicinity of an incident surface of the light guide plate, and an end surface opposite to the incident surface of the light guide plate. A quarter-wave plate arranged in the vicinity, a first reflection plate arranged outside the quarter-wave plate, and a second reflection plate arranged in the vicinity of the surface opposite to the emission surface of the light guide plate. One medium forming the light guide plate is provided with a thin film chip, and the chip is uniformly dispersed in the other medium in a state of being inclined with respect to the traveling direction of the incident light.
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、無偏光の光を光源
とする面状発光装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar light emitting device using unpolarized light as a light source.
【０００２】[0002]
【従来の技術】パーソナルコンピュータやワードプロセ
ッサなどのディスプレイには、液晶ディスプレイ装置が
用いられている。この種の装置では、バックライトの出
射光を光拡散シートやプリズムシート等によって拡散・
集光することにより、画面を見る人にとって非常に明る
く、見やすいように設計がなされている。2. Description of the Related Art Liquid crystal display devices are used for displays such as personal computers and word processors. In this type of device, the light emitted from the backlight is diffused by a light diffusion sheet or prism sheet.
By condensing light, it is designed to be very bright and easy for the viewer to see.
【０００３】しかし、実際には、導光板や液晶セルを通
過する際に光の吸収があるため、バックライトの光と画
面を通して見る光とでは、大きな差が生じている。特
に、導光板を通過する際には、Ｐ偏光、Ｓ偏光のうち一
方だけが透過し、もう一方は吸収されるため、５０％以
上の光が損失する。そこで、従来ではこの導光板による
吸収を削減する工夫がなされている。However, in reality, since light is absorbed when passing through the light guide plate or the liquid crystal cell, a large difference occurs between the light of the backlight and the light viewed through the screen. In particular, when passing through the light guide plate, only one of P-polarized light and S-polarized light is transmitted and the other is absorbed, so that 50% or more of light is lost. Therefore, conventionally, measures have been taken to reduce the absorption by the light guide plate.
【０００４】例えば、特開平７−６４０８５号公報に
は、プリズムアレイの凹凸面に誘電体干渉膜を１層以上
積層し、プリズムアレイと誘電体干渉膜との界面、また
は積層された誘電体干渉膜間の界面でＳ偏光とＰ偏光に
分離し、一方の偏光を透過させ、もう一方の偏光を全反
射を繰り返す構成とすることによって、再び光拡散シー
ト、または導光板のドット印刷に当たるようにし、そし
て、この光拡散シート、またはドット印刷に当たった光
は拡散され、偏光は無偏光に変換され再利用される構成
のものが開示されている。この技術では、Ｓ偏光やＰ偏
光の分離は完全ではないものの、一方の偏光が多く出射
されるように工夫されており、これにより導光板を通過
する光を多くすることができるようになっている。For example, in Japanese Unexamined Patent Publication No. 7-64085, one or more layers of dielectric interference films are laminated on the concavo-convex surface of the prism array, and the interface between the prism array and the dielectric interference film or the laminated dielectric interference film. By separating the S-polarized light and P-polarized light at the interface between the films, transmitting one polarized light, and repeating total reflection of the other polarized light, it is possible to hit the light diffusing sheet or the dot guide on the light guide plate again. The light diffusing sheet, or the light hitting the dot printing is diffused, and the polarized light is converted into non-polarized light and reused. Although this technique does not completely separate the S-polarized light and the P-polarized light, it is devised so that one polarized light is emitted in large amount, which makes it possible to increase the amount of light passing through the light guide plate. There is.
【０００５】また他の例として、特開平６−２７４２０
号公報には、入射光を偏光ビームスプリッタでＳ偏光と
Ｐ偏光に分離し、Ｓ偏光を１／２波長板に通してＰ偏光
に変換した後、コンデンサーレンズで元のＰ偏光と合成
し、凹面鏡で液晶セルに入射させる技術が開示されてい
る。As another example, JP-A-6-27420
In the publication, the incident light is separated into S-polarized light and P-polarized light by a polarization beam splitter, the S-polarized light is passed through a half-wave plate to be converted into P-polarized light, which is then combined with the original P-polarized light by a condenser lens. A technique for making a liquid crystal cell enter with a concave mirror is disclosed.
【０００６】このようにこれらの技術は、バックライト
の出射光が導光板を通過する際に、Ｐ偏光またはＳ偏光
のうち、一方の偏光のみを透過し、もう一方の偏光を吸
収する構成としたものである。そこで、予め導光板に入
射する光をＰ偏光またはＳ偏光に統一するか、もしくは
大部分を一方の偏光として、導光板に入射させることに
より高輝度化、低消費電力化が図られたものとなってい
る。As described above, these techniques have a configuration in which, when the light emitted from the backlight passes through the light guide plate, only one of P-polarized light and S-polarized light is transmitted and the other polarized light is absorbed. It was done. Therefore, it is assumed that the light incident on the light guide plate is unified into P-polarized light or S-polarized light in advance, or most of the light is made to be one polarized light and is incident on the light guide plate, thereby achieving high brightness and low power consumption. Has become.
【０００７】[0007]
【発明が解決しようとする課題】ところで、前者の従来
技術では、プリズムアレイへの入射光がプリズムアレイ
に対して垂直に入射されることが前提であり、実際には
拡散シートを介した光は拡散光であるから、効率が悪
い。さらに、界面でのＰ偏光またはＳ偏光の分離は媒質
の屈折率差にもよるが、数％程度のＳ偏光を取り除いて
再利用するにすぎない。したがって、光の利用が、充分
なされていない。By the way, in the former prior art, it is premised that the light incident on the prism array is vertically incident on the prism array, and in reality, the light passing through the diffusion sheet is Since it is diffused light, it is inefficient. Further, the separation of P-polarized light or S-polarized light at the interface depends on the difference in the refractive index of the medium, but only a few% of S-polarized light is removed and reused. Therefore, the utilization of light is not sufficient.
【０００８】また、後者の従来技術では、Ｐ偏光または
Ｓ偏光の分離、及びＳ偏光をＰ偏光に変換して元のＰ偏
光と合成することはできるものの、凹面鏡とコンデンサ
レンズ間、凹面鏡と液晶セル間に距離が必要であるため
装置のコンパクト化を阻害する上、偏光ビームスプリッ
タやコンデンサレンズ等の高価な光学部品が必要となる
ためコスト高となる不具合がある。Further, in the latter prior art, although it is possible to separate P-polarized light or S-polarized light and convert S-polarized light into P-polarized light and synthesize with the original P-polarized light, between the concave mirror and the condenser lens, the concave mirror and the liquid crystal. Since the distance between the cells is required, it hinders downsizing of the device, and expensive optical parts such as a polarization beam splitter and a condenser lens are required, resulting in high cost.
【０００９】さらに、これらの従来技術では、光拡散シ
ートの凹凸による山や谷の部分を上面から観察すると線
状に見えるが、この線と液晶の画素ピッチによってモア
レと呼ばれる干渉現象を起こし、液晶ディスプレイを見
る際に画質の悪さを感じさせるといった問題もある。Further, in these prior arts, the peaks and valleys due to the unevenness of the light diffusing sheet appear to be linear when viewed from the top surface, but due to this line and the pixel pitch of the liquid crystal, an interference phenomenon called moire occurs, There is also a problem that the user feels poor image quality when looking at the display.
【００１０】本発明はこれらの点に鑑みてなされたもの
で、高輝度であり、かつ、画質感に優れ、しかも構成の
簡単な面状発光装置を提供することを目的とする。The present invention has been made in view of the above points, and an object of the present invention is to provide a planar light emitting device having high brightness, excellent image quality, and a simple structure.
【００１１】[0011]
【課題を解決するための手段】上記の目的を達成するた
めに、本発明の面状発光装置は、屈折率が互いに異なる
二つの媒質が隣接してなるとともに、一方の端面が入射
面とされており、かつ、この入射面と直交する面のうち
１つの面が出射面とされており、この入射面から入射し
た光を偏波面が互いに直交する第１，第２の偏光に分離
し、第１の偏光を上記出射面から出射させ、第２の偏光
を上記入射面とは反対側の端面側に向けて進行させる導
光板と、この導光板の入射面近傍に配置された線状の光
源と、上記導光板の入射面とは反対側の端面近傍に配置
され、第２の偏光の偏光面を９０度回転させるための１
／４波長板と、この１／４波長板の外側に配置され、こ
の１／４波長板を通過してきた第２の偏光を反射させる
ことにより、この１／４波長板を介して上記導光板にこ
の第２の偏光を入射させるための第１の反射板と、上記
導光板の出射面とは反対の面近傍に配置された第２の反
射板とを備えた面状発光装置であって、上記導光板を構
成する一方の媒質が薄膜状のチップからなり、このチッ
プが入射光の進行方向に対して傾斜した状態で、もう一
方の媒質中に均一に分散されていることによって特徴付
けられる。In order to achieve the above object, in the surface light emitting device of the present invention, two media having different refractive indexes are adjacent to each other, and one end face is made to be an incident surface. In addition, one of the surfaces orthogonal to this incident surface is the exit surface, and the light incident from this incident surface is split into first and second polarized lights whose polarization planes are orthogonal to each other, A light guide plate that emits the first polarized light from the emission surface and advances the second polarized light toward the end face side opposite to the incident surface, and a linear light guide plate disposed near the incident surface of the light guide plate. 1 for arranging the light source and the polarization plane of the second polarization 90 degrees near the end face of the light guide plate opposite to the incident face.
A quarter-wave plate and a light guide plate disposed outside the quarter-wave plate and reflecting the second polarized light that has passed through the quarter-wave plate through the quarter-wave plate. A planar light emitting device comprising: a first reflecting plate for allowing the second polarized light to enter; and a second reflecting plate arranged near the surface opposite to the exit surface of the light guide plate. , Characterized in that one medium constituting the light guide plate is composed of a thin film chip, and the chip is uniformly dispersed in the other medium in a state of being inclined with respect to the traveling direction of incident light. To be
【００１２】なお、このチップは、入射光の進行方向に
対して３０°〜６０°の傾斜角度で配置されるのが好ま
しく、４５°が最も好ましい。このように傾斜角度を３
０°〜６０°とする理由は、光源である例えば蛍光管な
どの線状の光源からの光は広がりをもつため、この自然
偏光のうちＳ偏光のみを反射するための角度、すなわ
ち、ブリュースタ角になる角度が１つに定まらないため
である。しかし、光源からの光が一番多く導光板に入射
する角度は入射面に垂直な方向であることを考慮すれ
ば、その光を出射面に垂直な方向に出射するためには、
傾斜角度を４５°とするのが最も好ましいといえる。The chip is preferably arranged at an inclination angle of 30 ° to 60 ° with respect to the traveling direction of incident light, and most preferably 45 °. In this way the tilt angle is 3
The reason for setting it to 0 ° to 60 ° is that the light from a linear light source such as a fluorescent tube, which is a light source, has a spread, and therefore the angle for reflecting only S-polarized light out of the natural polarized light, that is, Brewster This is because the number of corners is not fixed. However, considering that the angle at which the light from the light source is most incident on the light guide plate is in the direction perpendicular to the incident surface, in order to emit the light in the direction perpendicular to the emission surface,
It can be said that it is most preferable that the inclination angle is 45 °.
【００１３】[0013]
【作用】薄膜状のチップは、導光板内の各所でそれぞれ
最適な界面分布が形成される。したがって、偏光分離が
最適に行われる。In the thin film chip, the optimum interface distribution is formed in each part of the light guide plate. Therefore, polarization separation is optimally performed.
【００１４】これは、線状の光源からの光が一番多く導
光板に入射する角度は入射面に垂直な方向であり、この
光がチップに入射し、おおむねブリュースタ角となるも
う一方の媒質との界面でほぼＳ偏光のみとなる光を出射
面に垂直に出射し、残りのＳ偏光とＰ偏光は透過し、次
の界面で再びＳ偏光の一部を出射面に垂直に出射する。
これを繰り返し、入射面とは反対側の端面に到達すると
きはＰ偏光のみとなる。次に、Ｐ偏光が１／４波長板を
通過し、第１の反射板によって反射したＰ偏光が再び１
／４波長板を通過することによって、Ｐ偏光はＳ偏光に
変換される。このＳ偏光の一部が同様に出射面に垂直に
出射し、最終的には出射方向にはおおむね偏光の揃った
光が出射される。This is because the angle at which the light from the linear light source is most incident on the light guide plate is in the direction perpendicular to the incident surface, and this light is incident on the chip, and the other is approximately Brewster's angle. At the interface with the medium, light that is almost only S-polarized light is emitted perpendicularly to the emission surface, the remaining S-polarized light and P-polarized light are transmitted, and at the next interface, part of the S-polarized light is emitted again perpendicularly to the emission surface. .
By repeating this, when reaching the end surface on the side opposite to the incident surface, only P-polarized light is obtained. Next, the P-polarized light passes through the quarter-wave plate, and the P-polarized light reflected by the first reflecting plate becomes 1 again.
P-polarized light is converted to S-polarized light by passing through the / 4 wave plate. Similarly, a part of the S-polarized light is emitted perpendicularly to the emission surface, and finally, light whose polarization is substantially uniform is emitted in the emission direction.
【００１５】また、導光板には凹凸がなく、一様である
からモアレを起こすこともなく、画質感を損ねることが
ない。Further, since the light guide plate has no unevenness and is uniform, moire does not occur and the image quality is not impaired.
【００１６】[0016]
【発明の実施の形態】以下、図面を参照しつつ本発明の
好適な実施の形態について説明する。図１はその実施に
際して用いるのに適した面状発光装置の構成例を模式的
に示す縦断面図である。また、図２はその面状発光装置
の構成をなす導光板１０を示す模式図で、（ａ）はその
斜視図、（ｂ）は側面図、（ｃ）は断面図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view schematically showing a configuration example of a planar light emitting device suitable for use in the implementation. 2A and 2B are schematic views showing the light guide plate 10 constituting the planar light emitting device, FIG. 2A is a perspective view thereof, FIG. 2B is a side view, and FIG.
【００１７】この例において、導光板１０は、アクリル
系樹脂からなり、屈折率が互いに異なる二つの媒質３，
８からなり、一方の媒質は薄膜状のチップ８（屈折率＝
１．５３）からなり、このチップ８が入射光の進行方向
に対して４５°傾斜した状態で、もう一方の媒質３（屈
折率＝１．４９）中に均一に分散されている。また、媒
質３は可視光の照射によって硬化するものとなってい
る。In this example, the light guide plate 10 is made of an acrylic resin and has two mediums 3, 3 having different refractive indexes.
8 of which one medium is a thin film chip 8 (refractive index =
1.53), the chips 8 are uniformly dispersed in the other medium 3 (refractive index = 1.49) in a state of being inclined by 45 ° with respect to the traveling direction of incident light. The medium 3 is hardened by irradiation with visible light.
【００１８】さて、この導光板１０の一方の端面１０ａ
側には線状光源として蛍光管１が配設されており、この
蛍光管１はランプリフレクタ２に覆われている。また、
導光板１０のもう一方の端面１０ｂ側には、反射ミラー
６が配設され、この反射ミラー６ともう一方の端面１０
ｂとの間には１／４波長板５が配設されている。また、
この導光板１０の裏面１０ｃ近傍には下面ミラー７が、
また残りの側端面２面（図示せず）にもそれぞれ反射ミ
ラーが配設されている。Now, one end face 10a of the light guide plate 10
A fluorescent tube 1 as a linear light source is arranged on the side, and the fluorescent tube 1 is covered with a lamp reflector 2. Also,
A reflection mirror 6 is disposed on the other end surface 10b side of the light guide plate 10, and the reflection mirror 6 and the other end surface 10 are provided.
A quarter-wave plate 5 is arranged between b and b. Also,
The lower surface mirror 7 is provided near the back surface 10c of the light guide plate 10,
Reflecting mirrors are also arranged on the remaining two side end surfaces (not shown).
【００１９】また、上記したように、導光板１０の構成
において、媒質８を４５°の傾斜角で配置した場合、蛍
光管１からの光が入射面に垂直な方向であれば、光が一
番多く導光板１０内に入射されるとともに、光をディス
プレイの垂直方向に出射することが可能になる。これに
より、蛍光管１からの光が広がりをもった光であるた
め、ブリュースタ角とする角度が１つに定まらないこと
による不具合はない。Further, as described above, in the structure of the light guide plate 10, when the medium 8 is arranged at the inclination angle of 45 °, if the light from the fluorescent tube 1 is in the direction perpendicular to the incident surface, the light is A large number of light beams are made incident on the light guide plate 10, and light can be emitted in the vertical direction of the display. As a result, since the light from the fluorescent tube 1 is a light having a spread, there is no problem due to the fact that the Brewster angle is not fixed at one.
【００２０】以上の構成による面状発光装置の作用を図
３を参照しながら説明する。まず、図３（ａ）に示すよ
うに、蛍光管１からの自然偏光は導光板１０の入光面と
なる端面１０ａに垂直に入射される。この光はチップ８
に入射し、媒質３との界面で反射するとともに透過す
る。ここでは全体の数％程度の反射率である。これが式
（１）に示すブリュースタ角φであればＳ偏光のみを反
射する。このブリュースタ角φは媒質の屈折率に依る、
Ｓ偏光のみを反射する角度である。なお、式（１）にお
いて、ｎA ，ｎB はそれぞれ媒質Ａ，Ｂの屈折率であ
る。The operation of the planar light emitting device having the above structure will be described with reference to FIG. First, as shown in FIG. 3A, the naturally polarized light from the fluorescent tube 1 is vertically incident on the end surface 10 a which is the light entrance surface of the light guide plate 10. This light is chip 8
Incident on the medium 3, reflected at the interface with the medium 3, and transmitted. Here, the reflectance is about several percent of the whole. If this is the Brewster angle φ shown in Expression (1), only S-polarized light is reflected. This Brewster angle φ depends on the refractive index of the medium,
This is the angle that reflects only S-polarized light. In the formula (1), n A and n B are the refractive indices of the media A and B, respectively.
【００２１】[0021]
【数１】 (Equation 1)
【００２２】次に、透過光はなおＳ偏光とＰ偏光の両方
を含む自然偏向光であるが、次の媒質８と媒質３との界
面で再びＳ偏光だけが数％分離される。これを繰り返し
てＳ偏光は出射面に垂直な方向に出射する。一方、透過
光は順次媒質８と媒質３との界面でＳ偏光を減少するの
で、最終的にはＰ偏光のみが残る。Next, the transmitted light is naturally polarized light that still contains both S-polarized light and P-polarized light, but only S-polarized light is separated again by several% at the interface between the next medium 8 and medium 3. By repeating this, the S-polarized light is emitted in the direction perpendicular to the emission surface. On the other hand, since the transmitted light sequentially decreases the S-polarized light at the interface between the medium 8 and the medium 3, only P-polarized light remains in the end.
【００２３】そして、図３（ｂ）に示すように、このＰ
偏光は１／４波長板５を透過した後、反射ミラー６によ
って反射し、その反射光は再び１／４波長板５を透過す
る。これにより、Ｐ偏光は１／２波長板を通過したこと
と同等となり、このＰ偏光はＳ偏光に変換される。こう
してＳ偏光に変換された光は、再び導光板１０に入射さ
れる。Then, as shown in FIG.
The polarized light passes through the quarter-wave plate 5 and then is reflected by the reflection mirror 6, and the reflected light passes through the quarter-wave plate 5 again. As a result, the P-polarized light is equivalent to passing through the half-wave plate, and the P-polarized light is converted into S-polarized light. The light converted into S-polarized light in this way is incident on the light guide plate 10 again.
【００２４】そして、図３（ｃ）に示すように、このＳ
偏光のみの光は、数％ずつ反射され、その反射光は下面
ミラー６で反射された後、出射面から出射される。この
ようにして、最終的には出射面から、おおむね偏向の揃
った光が出射され、面内の出射分布の均一性が実現され
る。しかも、本発明の実施の形態では、従来の技術にあ
るようなビームスプリッタやコンデンサーレンズ等の高
価な光学部品を用いる必要もない。また、従来の技術に
あるような、画質の悪さの原因であった干渉現象を起こ
すこともなく、したがって、画質感を損ねることもな
い。Then, as shown in FIG.
The polarized light alone is reflected by several%, and the reflected light is reflected by the lower surface mirror 6 and then emitted from the emission surface. In this way, finally, light whose polarization is substantially uniform is emitted from the emission surface, and the uniformity of the emission distribution in the surface is realized. Moreover, in the embodiment of the present invention, it is not necessary to use expensive optical components such as a beam splitter and a condenser lens as in the conventional technique. In addition, there is no occurrence of an interference phenomenon which is a cause of poor image quality as in the conventional technique, and therefore the image quality is not impaired.
【００２５】[0025]
【実施例】以下に実施例を２例、比較例を２例示し、こ
れらの評価方法及び評価結果を示す。 （実施例１） 〔１〕硬化用分散液の作製 まず、媒質Ａとして可視光硬化型のアクリル系樹脂（屈
折率ｎ＝１．４９）を用意し、これに対して媒質Ｂとし
て、アクリル系樹脂（屈折率ｎ＝１．５３）を直径１．
５ｍｍ、厚さ０．２ｍｍのディスク状に成形したものを
用意した。EXAMPLES Two examples and two comparative examples will be illustrated below, and the evaluation methods and evaluation results thereof will be shown. Example 1 [1] Preparation of Curing Dispersion Liquid First, a visible light curable acrylic resin (refractive index n = 1.49) was prepared as a medium A, while an acrylic resin was used as a medium B. A resin (refractive index n = 1.53) has a diameter of 1.
A disk-shaped product having a thickness of 5 mm and a thickness of 0.2 mm was prepared.
【００２６】次に、媒質Ａ４０ｇに対し６０ｇの媒質Ｂ
を加え、攪拌した後気泡が抜けるまで静置しておくこと
によって、硬化用分散液を得た。 〔２〕導光板の作製 図４に示した、縦１５ｃｍ，横２２ｃｍ，厚み３ｍｍの
直方体形状の樹脂充填用の穴３３を有した光硬化槽３０
に、導光板の端部となるアクリル系樹脂からなる三角柱
状部材３２を配置した後、予め用意しておいた硬化用分
散液を、注入口３１から注入して穴３３に満たし、分散
中の媒質Ｂが導光板の光線進行方向に対して４５度すな
わち、光硬化槽底部に配置した三角柱状部材３２をの上
面に対してディスク面を向けて沈降配列するように適度
に振動を与え静置した。Next, 60 g of medium B for 40 g of medium A
Was added, and the mixture was stirred and allowed to stand until bubbles were removed to obtain a curing dispersion liquid. [2] Fabrication of light guide plate Photocuring tank 30 shown in FIG. 4 having a rectangular parallelepiped resin filling hole 33 having a length of 15 cm, a width of 22 cm, and a thickness of 3 mm.
After arranging the triangular columnar member 32 made of acrylic resin, which will be the end portion of the light guide plate, in the above, the curing dispersion liquid prepared in advance is injected from the injection port 31 to fill the hole 33, and The medium B is set at 45 degrees with respect to the light traveling direction of the light guide plate, that is, the triangular columnar member 32 arranged at the bottom of the photo-curing tank is appropriately placed in a vibration direction so that the medium surface is set in a sinking direction with the disk surface facing the upper surface of the triangular columnar member 32 and is left stationary. did.
【００２７】次に、導光板のもう一方の端部となるアク
リル系樹脂からなる三角柱状部材（図示せず）を、充填
した硬化用分散液の上部に配置した後、キセノンランプ
を光源として５０ｍＷで３０分照射し、硬化用分散液を
硬化させた後、光硬化槽を分離開口し、出来上がった導
光板を取り出した。この導光板を用いた装置が実施例１
である。 （実施例２）図５に示した光硬化槽４０に、導光板の端
部となるアクリル系樹脂からなる三角柱状部材４２を配
置した後、予め用意しておいた硬化用分散液を、注入口
４１から注入して穴４３に満たし、分散中の媒質Ｂが導
光板の光線進行方向に対して４５度すなわち、光硬化槽
底部に配置した三角柱状部材３２をの上面に対してディ
スク面を向けて沈降配列するように適度に振動を与え静
置した。Next, a triangular columnar member (not shown) made of an acrylic resin, which is the other end of the light guide plate, is placed on top of the filled curing dispersion liquid, and then 50 mW is used with a xenon lamp as a light source. After 30 minutes of irradiation to cure the curing dispersion liquid, the photocuring tank was separated and opened, and the completed light guide plate was taken out. A device using this light guide plate is the first embodiment.
It is. (Embodiment 2) A triangular columnar member 42 made of an acrylic resin, which is an end portion of a light guide plate, is placed in the photocuring tank 40 shown in FIG. 5, and then a previously prepared curing dispersion liquid is poured. The medium B is injected from the inlet 41 to fill the hole 43, and the medium B in the dispersion is 45 degrees with respect to the light ray traveling direction of the light guide plate, that is, the triangular prismatic member 32 arranged at the bottom of the photocuring tank has a disc surface with respect to the upper surface. It was left still by giving appropriate vibration so that it may be settled toward the surface.
【００２８】次に、導光板のもう一方の端部となるアク
リル系樹脂からなる三角柱状部材（図示せず）を、充填
した硬化用分散液の上部に配置した後、光硬化槽４０を
４５度傾けた状態でキセノンランプを光源として５０ｍ
Ｗで３０分照射し、硬化用分散液を硬化させた後、光硬
化槽を分離開口し、出来上がった導光板を取り出した。
この導光板を用いた装置が実施例２である。 （比較例１）ドット印刷パターンと拡散反射シートと蛍
光管とリフレクタとアクリル導光体とを備えた従来のバ
ックライトに光拡散シート（ビーズコーティングタイ
プ）と頂角がおおむね９０°のプリズムシートを２枚直
交した状態で配置した装置が、比較例２である。 （比較例２）特開平７−６４０８５に記載の偏光素子を
用いたものを比較例３である。Next, a triangular columnar member (not shown) made of an acrylic resin, which is the other end of the light guide plate, is placed above the filled dispersion liquid for curing, and then the photocuring tank 40 is placed at 45. 50m with a xenon lamp as the light source while tilted
After irradiation with W for 30 minutes to cure the curing dispersion liquid, the photocuring tank was separated and opened, and the completed light guide plate was taken out.
Example 2 is an apparatus using this light guide plate. (Comparative Example 1) A light diffusion sheet (bead coating type) and a prism sheet having an apex angle of about 90 ° are added to a conventional backlight provided with a dot printing pattern, a diffuse reflection sheet, a fluorescent tube, a reflector and an acrylic light guide. Comparative Example 2 is an apparatus in which two sheets are arranged orthogonal to each other. (Comparative Example 2) Comparative Example 3 uses the polarizing element described in JP-A-7-64085.
【００２９】以上の２つの実施例及び２つの比較例の面
状発光装置のそれぞれに対し、以下に示す評価方法によ
り評価を行う。 （１）画面中央での導光板を透過した光の輝度を測定
し、評価を行う。 （２）導光板を透過する光の透過光量を測定し、導光板
の手前と後でどれだけの光が透過したかを評価する。 （３）各例の装置に５種類の液晶セルを組み合わせ、点
灯時に、人間の目で画質感（干渉縞の発生の確認）を評
価する。組み合わせによって１つでも画質感の悪いもの
があった時、この評価項目に対しては不適とみなすもの
とする。Each of the planar light emitting devices of the above two examples and two comparative examples is evaluated by the following evaluation method. (1) The brightness of the light transmitted through the light guide plate at the center of the screen is measured and evaluated. (2) The amount of light transmitted through the light guide plate is measured to evaluate how much light is transmitted before and after the light guide plate. (3) Five types of liquid crystal cells are combined with the device of each example, and the image quality feeling (confirmation of occurrence of interference fringes) is evaluated by the human eye when the light is turned on. If even one of the combinations has a poor image quality, it is considered to be unsuitable for this evaluation item.
【００３０】この評価結果を表１に示す。The results of this evaluation are shown in Table 1.
【００３１】[0031]
【表１】 [Table 1]
【００３２】この結果から明らかなように、本願実施例
では輝度、透過光量ともに比較例に比べ、大きい値とな
り、また、画質感も良好なものとなった。As is clear from these results, both the luminance and the amount of transmitted light in the present Example were larger than those in the Comparative Example, and the image quality was also good.
【００３３】[0033]
【発明の効果】以上述べたように、本発明の面状発光装
置は、導光板を構成する一方の媒質を薄膜状のチップと
し、このチップを入射光の進行方向に対して傾斜した状
態で、もう一方の媒質中に均一に分散した構成としたの
で、光を有効に利用することができ、輝度の高い、しか
も画質感に優れた発光を実現することができる。しか
も、簡単な構成で実現でき、コンパクト化を可能とする
とともに、製造コストを低く抑えることができる。As described above, in the planar light emitting device of the present invention, one medium forming the light guide plate is a thin film chip, and the chip is inclined with respect to the traveling direction of the incident light. Since the structure is uniformly dispersed in the other medium, it is possible to effectively use light, and it is possible to realize light emission with high brightness and excellent image quality. In addition, it can be realized with a simple structure, can be made compact, and the manufacturing cost can be kept low.
【図１】本発明の実施の形態に適用される面状発光装置
の構成を模式的に示す縦断面図FIG. 1 is a vertical sectional view schematically showing a configuration of a planar light emitting device applied to an embodiment of the present invention.
【図２】本発明の実施の形態に適用される面状発光装置
の導光板を示す模式的に示す図FIG. 2 is a diagram schematically showing a light guide plate of a planar light emitting device applied to an embodiment of the present invention.
【図３】本発明の実施の形態に適用される面状発光装置
の作用を説明するための図FIG. 3 is a diagram for explaining the operation of the planar light emitting device applied to the embodiment of the present invention.
【図４】本発明の実施の形態に適用される面状発光装置
の導光板を製造方法を説明するための図FIG. 4 is a diagram illustrating a method for manufacturing a light guide plate of a planar light emitting device applied to an embodiment of the present invention.
【図５】本発明の実施の形態に適用される面状発光装置
の導光板を製造方法を説明するための図FIG. 5 is a diagram for explaining a method of manufacturing the light guide plate of the planar light emitting device applied to the embodiment of the present invention.
１ 蛍光管 ５ １／４波長板 ６ 反射板 ７ 下面ミラー ８ チップ（媒質Ｂ） ３ 媒質 （媒質Ａ） １０ 導光板 1 Fluorescent Tube 5 1/4 Wave Plate 6 Reflector 7 Bottom Mirror 8 Chip (Medium B) 3 Medium (Medium A) 10 Light Guide Plate
Claims (1)
してなるとともに、一方の端面が入射面とされており、
かつ、この入射面と直交する面のうち１つの面が出射面
とされており、この入射面から入射した光を偏波面が互
いに直交する第１，第２の偏光に分離し、第１の偏光を
上記出射面から出射させ、第２の偏光を上記入射面とは
反対側の端面側に向けて進行させる導光板と、 この導光板の入射面近傍に配置された線状の光源と、 上記導光板の入射面とは反対側の端面近傍に配置され、
第２の偏光の偏光面を９０度回転させるための１／４波
長板と、 この１／４波長板の外側に配置され、この１／４波長板
を通過してきた第２の偏光を反射させることにより、こ
の１／４波長板を介して上記導光板にこの第２の偏光を
入射させるための第１の反射板と、 上記導光板の出射面とは反対の面近傍に配置された第２
の反射板と、を備えた面状発光装置であって、上記導光
板を構成する一方の媒質が薄膜状のチップからなり、こ
のチップが入射光の進行方向に対して傾斜した状態で、
もう一方の媒質中に均一に分散されていることを特徴と
する面状発光装置。1. Two mediums having different refractive indexes are adjacent to each other, and one end surface is an incident surface,
In addition, one of the surfaces orthogonal to this incident surface is the exit surface, and the light incident from this incident surface is split into first and second polarized light whose polarization planes are orthogonal to each other, and A light guide plate for emitting polarized light from the emission surface and advancing second polarized light toward an end face side opposite to the incident surface; and a linear light source arranged near the incident surface of the light guide plate, The light guide plate is arranged in the vicinity of the end surface on the side opposite to the incident surface,
A quarter-wave plate for rotating the polarization plane of the second polarized light by 90 degrees, and a second polarized light that is arranged outside the quarter-wave plate and that has passed through the quarter-wave plate is reflected. As a result, a first reflecting plate for allowing the second polarized light to enter the light guide plate through the quarter-wave plate and a first reflector plate disposed near the surface opposite to the exit surface of the light guide plate. Two
In a planar light emitting device comprising: a reflection plate, one medium constituting the light guide plate is a thin film chip, and the chip is inclined with respect to the traveling direction of incident light,
A planar light emitting device characterized by being uniformly dispersed in the other medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31245995A JP3530291B2 (en) | 1995-11-30 | 1995-11-30 | Planar light emitting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31245995A JP3530291B2 (en) | 1995-11-30 | 1995-11-30 | Planar light emitting device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09152604A true JPH09152604A (en) | 1997-06-10 |
| JP3530291B2 JP3530291B2 (en) | 2004-05-24 |
Family
ID=18029458
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31245995A Expired - Fee Related JP3530291B2 (en) | 1995-11-30 | 1995-11-30 | Planar light emitting device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3530291B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1064319A (en) * | 1996-07-16 | 1998-03-06 | Thomson Csf | Lighting system and its application to lighting of transmitting screen |
| JP2003257227A (en) * | 2001-04-24 | 2003-09-12 | Sharp Corp | Illumination device, display device including the same, and light guide plate |
| US6952310B1 (en) | 1999-05-12 | 2005-10-04 | Nitto Denko Corporation | Light pipe and polarized-light source |
| US7268483B2 (en) | 2002-12-26 | 2007-09-11 | Nitto Denko Corporation | Optical element, as well as polarized-light-emitting surface light source and display device using the same |
| WO2015016048A1 (en) * | 2013-07-30 | 2015-02-05 | 堺ディスプレイプロダクト株式会社 | Light source device, illumination device, and liquid crystal display device |
-
1995
- 1995-11-30 JP JP31245995A patent/JP3530291B2/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1064319A (en) * | 1996-07-16 | 1998-03-06 | Thomson Csf | Lighting system and its application to lighting of transmitting screen |
| US6952310B1 (en) | 1999-05-12 | 2005-10-04 | Nitto Denko Corporation | Light pipe and polarized-light source |
| US7446938B2 (en) | 1999-05-12 | 2008-11-04 | Nitto Denko Corporation | Light pipe and polarized-light source |
| US7515339B2 (en) | 1999-05-12 | 2009-04-07 | Nitto Denko Corporation | Light pipe and polarized-light source |
| US7532398B2 (en) | 1999-05-12 | 2009-05-12 | Nitto Denko Corporation | Light pipe and polarized-light source |
| JP2003257227A (en) * | 2001-04-24 | 2003-09-12 | Sharp Corp | Illumination device, display device including the same, and light guide plate |
| US7268483B2 (en) | 2002-12-26 | 2007-09-11 | Nitto Denko Corporation | Optical element, as well as polarized-light-emitting surface light source and display device using the same |
| WO2015016048A1 (en) * | 2013-07-30 | 2015-02-05 | 堺ディスプレイプロダクト株式会社 | Light source device, illumination device, and liquid crystal display device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3530291B2 (en) | 2004-05-24 |
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