JP2002279812A - Surface light source - Google Patents
Surface light sourceInfo
- Publication number
- JP2002279812A JP2002279812A JP2001079089A JP2001079089A JP2002279812A JP 2002279812 A JP2002279812 A JP 2002279812A JP 2001079089 A JP2001079089 A JP 2001079089A JP 2001079089 A JP2001079089 A JP 2001079089A JP 2002279812 A JP2002279812 A JP 2002279812A
- Authority
- JP
- Japan
- Prior art keywords
- light
- guide plate
- light guide
- face
- light source
- 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.)
- Pending
Links
Landscapes
- Light Guides In General And Applications Therefor (AREA)
- Liquid Crystal (AREA)
- Planar Illumination Modules (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、液晶表示装置の
光源等に用いられる面光源に関するものである。[0001] 1. Field of the Invention [0002] The present invention relates to a surface light source used as a light source of a liquid crystal display device.
【０００２】[0002]
【従来の技術】液晶表示装置の光源等に用いられる面光
源として、光源部からの出射光を導光板により導いてそ
の前面から出射するものがある。2. Description of the Related Art As a surface light source used as a light source of a liquid crystal display device, there is a surface light source which guides light emitted from a light source section by a light guide plate and emits the light from the front surface thereof.
【０００３】図１１は従来の面光源装置を示す側面図で
あり、この面光源は、光が入射される入射端面１ａと入
射された光が出射する前面１ｂおよびこの前面１ｂと対
向する後面１ｃとからなる導光板１と、前記導光板１の
入射端面１ａに対向させて配置された光源部３とからな
っている。FIG. 11 is a side view showing a conventional surface light source device. The surface light source includes an incident end surface 1a on which light is incident, a front surface 1b from which the incident light is emitted, and a rear surface 1c opposed to the front surface 1b. And a light source unit 3 arranged to face the incident end face 1a of the light guide plate 1.
【０００４】前記導光板１は、出射面である前面１ｂが
平坦面に形成され、後面１ｃが前記入射端面１ａから他
端側に向かって前面１ｂに近づくように傾斜する傾斜面
に形成された楔板状の透明板（例えばアクリル系樹脂
板）からなっており、この導光板１の後面１ｃには、そ
の全面にわたって反射膜２が設けられている。The light guide plate 1 has a front surface 1b, which is an emission surface, formed as a flat surface, and a rear surface 1c formed as an inclined surface inclined so as to approach the front surface 1b from the incident end surface 1a toward the other end. It is formed of a wedge-shaped transparent plate (for example, an acrylic resin plate), and a reflection film 2 is provided on the entire rear surface 1 c of the light guide plate 1.
【０００５】また、前記光源部３は、例えば、前記導光
板１の入射端面１ａの全長にわたる長さの冷陰極管４
と、この冷陰極管４からの出射光を前記導光板１の入射
端面１ａに向けて反射するリフレクタ５とからなってい
る。The light source unit 3 includes, for example, a cold cathode tube 4 having a length extending over the entire length of the incident end face 1a of the light guide plate 1.
And a reflector 5 that reflects light emitted from the cold cathode tube 4 toward the incident end face 1a of the light guide plate 1.
【０００６】この面光源は、光源部３から出射し、導光
板１にその入射端面１ａから入射した光を、図１１に矢
線で示したように、導光板前面１ｂと外気（空気）との
界面での全反射と、導光板後面１ｃに設けられた反射膜
２での反射の繰り返しにより導光板１の長さ方向に導き
ながら、導光板前面１ｂと外気との界面に対して全反射
臨界角より小さい（垂直に近い）入射角で入射した光を
導光板前面１ｂから出射する。In this surface light source, light emitted from the light source unit 3 and incident on the light guide plate 1 from the incident end face 1a is, as shown by an arrow in FIG. 11, divided into the front surface 1b of the light guide plate and the outside air (air). Is reflected in the longitudinal direction of the light guide plate 1 by repetition of total reflection at the interface of the light guide plate and reflection at the reflection film 2 provided on the rear surface 1c of the light guide plate, and is totally reflected at the interface between the front surface 1b of the light guide plate and the outside air. Light incident at an incident angle smaller than the critical angle (near perpendicular) is emitted from the light guide plate front surface 1b.
【０００７】[0007]
【発明が解決しようとする課題】しかし、図１１に示し
た従来の面光源は、導光板１にその入射端面１ａから入
射してこの導光板１内を導かれる光のうち、導光板前面
１ｂの入射端面付近の領域に向かう光のほとんどが、導
光板前面１ｂと外気との界面に対して全反射臨界角より
も大きい入射角で入射して全反射されるため、導光板前
面１ｂの入射端面付近の領域から出射する光の強度が他
の領域から出射する光の強度に比べて弱く、したがっ
て、出射光の強度分布にむらがある。However, in the conventional surface light source shown in FIG. 11, the light incident on the light guide plate 1 from the incident end face 1a and guided through the light guide plate 1 is the light guide plate front surface 1b. Most of the light traveling toward the region near the incident end face of the light guide plate is incident on the interface between the light guide plate front surface 1b and the outside air at an incident angle larger than the critical angle for total reflection and is totally reflected. The intensity of light emitted from the region near the end face is lower than the intensity of light emitted from other regions, and therefore, the intensity distribution of the emitted light is uneven.
【０００８】この発明は、導光板の前面全体からほぼ均
一な強度の光を出射することができる面光源を提供する
ことを目的としたものである。SUMMARY OF THE INVENTION It is an object of the present invention to provide a surface light source capable of emitting light of substantially uniform intensity from the entire front surface of a light guide plate.
【０００９】[0009]
【課題を解決するための手段】この発明の面光源は、光
が入射される入射端面と入射された光が出射する前面お
よびこの前面と対向する後面とからなる導光板と、前記
導光板の入射端面に対向させて配置された光源部とから
なり、前記導光板の入射端面に、前記光源部からの出射
光を前記導光板の前面の法線に対する角度が小さくなる
方向に屈折させて前記導光板に入射させるための屈折面
が設けられていることを特徴とするものである。A surface light source according to the present invention comprises: a light guide plate having an incident end surface on which light is incident, a front surface from which the incident light is emitted, and a rear surface facing the front surface; A light source unit disposed opposite the incident end face, and the incident end face of the light guide plate is refracted in a direction in which the angle of light emitted from the light source unit with respect to the normal to the front surface of the light guide plate becomes smaller. It is characterized in that a refraction surface for entering the light guide plate is provided.
【００１０】この面光源によれば、光源部から出射し、
導光板にその入射端面から入射する光が、前記入射端面
に設けられた屈折面により前記導光板の前面の法線に対
する角度が小さくなる方向に屈折されて導光板に入射す
るため、前記導光板にその入射端面から入射してこの導
光板内を導かれる光を、導光板前面の入射端面付近の領
域にも全反射臨界角より小さい入射角で入射させ、導光
板前面の入射端面付近の領域からも充分な量の光を出射
させることができ、したがって、導光板の前面全体から
ほぼ均一な強度の光を出射することができる。According to this surface light source, the light is emitted from the light source unit,
The light incident on the light guide plate from the incident end face is refracted by the refraction surface provided on the incident end face in a direction in which the angle with respect to the normal to the front surface of the light guide plate becomes smaller and enters the light guide plate. The light that is incident from the incident end face and is guided through the light guide plate is also incident on the area near the incident end face on the front face of the light guide plate at an incident angle smaller than the critical angle for total reflection, and the area near the incident end face on the front face of the light guide plate. Therefore, a sufficient amount of light can be emitted from the light guide plate, and therefore, light with substantially uniform intensity can be emitted from the entire front surface of the light guide plate.
【００１１】また、この発明の他の面光源は、光が入射
される入射端面と入射された光が出射する前面およびこ
の前面と対向する後面とからなる導光板と、前記導光板
の入射端面に対向させて配置された光源部とからなり、
前記導光板の前面と後面の少なくとも一方の面の前記入
射端面側の端部に、前記光源部から出射し、前記導光板
に前記入射端面から入射した光を前記導光板の前面の法
線に対する角度が小さくなる方向に屈折させる屈折面が
形成されていることを特徴とするものである。Another surface light source of the present invention is a light guide plate comprising an incident end face on which light is incident, a front face from which the incident light is emitted, and a rear face opposite to the front face, and an incident end face of the light guide plate. And a light source section arranged to face the
At least one of the front surface and the rear surface of the light guide plate at the incident end surface side, the light emitted from the light source unit, and the light incident on the light guide plate from the incident end surface with respect to the normal to the front surface of the light guide plate A refracting surface for refracting light in a direction in which the angle becomes smaller is formed.
【００１２】この面光源によれば、光源部から出射し、
導光板に前記入射端面から入射した光が、前記導光板の
前面と後面の少なくとも一方の面の前記入射端面側の端
部に形成された屈折面により前記導光板の前面の法線に
対する角度が小さくなる方向に屈折されるため、前記導
光板にその入射端面から入射してこの導光板内を導かれ
る光を、導光板前面の入射端面付近の領域にも全反射臨
界角より小さい入射角で入射させ、導光板前面の入射端
面付近の領域からも充分な量の光を出射することがで
き、したがって、導光板の前面全体からほぼ均一な強度
の光を出射することができる。According to this surface light source, the light is emitted from the light source unit,
The light incident on the light guide plate from the incident end face has an angle with respect to a normal line of the front face of the light guide plate due to a refraction surface formed at an end of the light guide plate on the incident end face side of at least one of the front face and the rear face. Since the light is refracted in the smaller direction, light incident on the light guide plate from its incident end face and guided through the light guide plate is also incident on the light guide plate front surface in a region near the incident end face at an incident angle smaller than the critical angle for total reflection. When the light is incident, a sufficient amount of light can be emitted from a region near the incident end face of the front surface of the light guide plate, and therefore, light of substantially uniform intensity can be emitted from the entire front surface of the light guide plate.
【００１３】[0013]
【発明の実施の形態】この発明の面光源は、上記のよう
に、導光板の入射端面に、光源部からの出射光を前記導
光板の前面の法線に対する角度が小さくなる方向に屈折
させて前記導光板に入射させるための屈折面を設けるこ
とにより、前記導光板の前面全体からほぼ均一な強度の
光を出射するようにしたものである。DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the surface light source of the present invention refracts the light emitted from the light source section at the incident end face of the light guide plate in a direction in which the angle with respect to the normal to the front surface of the light guide plate becomes smaller. By providing a refraction surface for entering the light guide plate, light of substantially uniform intensity is emitted from the entire front surface of the light guide plate.
【００１４】この面光源において、前記導光板の入射端
面に設けられた屈折面は、前記入射端面の高さ方向に並
ぶ複数のプリズム面またはレンズ面からなっているのが
好ましい。In this surface light source, it is preferable that the refraction surface provided on the incident end face of the light guide plate comprises a plurality of prism faces or lens faces arranged in the height direction of the incident end face.
【００１５】また、この発明の他の面光源は、導光板の
前面と後面の少なくとも一方の面の入射端面側の端部
に、光源部から出射し、前記導光板に前記入射端面から
入射した光を前記導光板の前面の法線に対する角度が小
さくなる方向に屈折させる屈折面を形成することによ
り、前記導光板の前面全体からほぼ均一な強度の光を出
射するようにしたものである。According to another aspect of the present invention, at least one of the front and rear surfaces of the light guide plate emits light from the light source unit at the end on the incident end surface side, and enters the light guide plate from the incident end surface. By forming a refraction surface that refracts light in a direction in which the angle of the front surface of the light guide plate with respect to the normal to the front surface becomes smaller, light of substantially uniform intensity is emitted from the entire front surface of the light guide plate.
【００１６】この面光源において、前記導光板の前面と
後面の少なくとも一方の面の入射端面側の端部に形成さ
れた前記屈折面は、この屈折面が形成された前記面に対
し、前記入射端面から前記導光板の他端方向に向かって
前記導光板の内部方向に斜めに凹入する傾斜面からなっ
ているのが好ましい。In this surface light source, the refracting surface formed on the incident end surface side of at least one of the front surface and the rear surface of the light guide plate is configured such that the light incident surface is incident on the surface on which the refracting surface is formed. The light guide plate preferably has an inclined surface that is obliquely recessed in an inner direction of the light guide plate from an end face toward the other end of the light guide plate.
【００１７】また、この発明のいずれの面光源も、前記
導光板の前面の前側に、前記導光板の前面から出射した
光を所定の方向に屈折させる光学手段が配置された構成
のものが好ましい。Also, in any surface light source of the present invention, it is preferable that an optical means for refracting light emitted from the front surface of the light guide plate in a predetermined direction is disposed in front of the front surface of the light guide plate. .
【００１８】[0018]
【実施例】図１および図２はこの発明の第１の実施例を
示しており、図１は面光源の側面図、図２は前記面光源
の導光板の入射端面側の拡大側面図である。1 and 2 show a first embodiment of the present invention. FIG. 1 is a side view of a surface light source, and FIG. 2 is an enlarged side view of a light guide plate of the surface light source on an incident end face side. is there.
【００１９】この実施例の面光源は、図１および図２に
示すように、光が入射される入射端面１０ａと入射され
た光が出射する前面１０ｂおよびこの前面と対向する後
面１０ｃとからなる導光板１０と、前記導光板１０の入
射端面１０ａに対向させて配置された光源部２０とから
なっている。As shown in FIGS. 1 and 2, the surface light source of this embodiment includes an incident end face 10a on which light is incident, a front face 10b from which the incident light is emitted, and a rear face 10c facing the front face. The light guide plate 10 includes a light guide plate 10 and a light source unit 20 arranged to face the incident end face 10a of the light guide plate 10.
【００２０】前記導光板１０は、出射面である前面１０
ｂが平坦面に形成され、後面１０ｃが前記入射端面１０
ａから他端側に向かって前面１０ｂに近づくように傾斜
する傾斜面に形成された楔板状の透明板（例えばアクリ
ル系樹脂）からなっており、この導光板１０の後面１０
ｃには、その全面にわたって、アルミニウム等の高反射
率金属の蒸着またはメッキ膜からなる反射膜１１が設け
られている。The light guide plate 10 has a front surface 10 as an emission surface.
b is formed on a flat surface, and the rear surface 10c is
The light guide plate 10 is made of a transparent plate (for example, an acrylic resin) formed on an inclined surface that is inclined so as to approach the front surface 10b from the side a toward the other end.
c is provided with a reflective film 11 made of a vapor-deposited or plated film of a high-reflectance metal such as aluminum over its entire surface.
【００２１】また、この導光板１０の入射端面１０ａに
は、光源部２０からの出射光を前記導光板１０の前面１
０ｂの法線に対する角度が小さくなる方向に屈折させて
導光板１０に入射させるための屈折面１２が設けられて
いる。On the incident end face 10a of the light guide plate 10, light emitted from the light source unit 20 is applied to the front face 1 of the light guide plate 10.
A refracting surface 12 is provided for refracting light in a direction in which the angle with respect to the normal to 0b becomes smaller and entering the light guide plate 10.
【００２２】この屈折面１２は、例えば、前記入射端面
１０ａの高さ方向に並ぶ複数のプリズム面１２ａからな
っており、前記複数のプリズム面１２ａはそれぞれ、前
記入射端面１０ａの長さ方向（導光板１０の幅方向）に
沿う横長のプリズム状に形成されている。The refracting surface 12 is composed of, for example, a plurality of prism faces 12a arranged in the height direction of the incident end face 10a. It is formed in a horizontally long prism shape along the width direction of the optical plate 10).
【００２３】なお、図１および図２に示した導光板１０
は、その入射端面１０ａを前記複数のプリズム面１２ａ
からなる屈折面１２に形成したものであるが、前記導光
板１０は、入射端面を平坦面に形成し、その入射端面
に、前記屈折面１２が形成された端面層を設けたもので
もよく、その場合、前記端面層は、導光板とは別に成形
して前記導光板の入射端面に貼り付けても、前記導光板
の入射端面側を前記屈折面１２の成形金型に嵌め込み、
その金型内に光硬化性樹脂を射出して導光板側からの光
照射により硬化させることにより形成してもよい。 一
方、前記光源部２０は、例えば、前記導光板１０の入射
端面１０ａの全長にわたる長さの冷陰極管２１と、この
冷陰極管２１からの出射光を前記導光板１０の入射端面
１０ａに向けて反射するリフレクタ２２とからなってい
る。The light guide plate 10 shown in FIGS.
Sets the incident end face 10a to the plurality of prism faces 12a.
The light guide plate 10 may be formed such that the incident end face is formed as a flat surface and the incident end face is provided with an end face layer on which the refraction surface 12 is formed. In that case, even if the end face layer is molded separately from the light guide plate and is attached to the incident end face of the light guide plate, the incident end face side of the light guide plate is fitted into a mold for forming the refraction surface 12,
It may be formed by injecting a photocurable resin into the mold and curing the resin by light irradiation from the light guide plate side. On the other hand, the light source unit 20 is, for example, a cold cathode tube 21 having a length extending over the entire length of the incident end face 10 a of the light guide plate 10, and directs light emitted from the cold cathode tube 21 to the incident end face 10 a of the light guide plate 10. And a reflector 22 that reflects light.
【００２４】この面光源は、前記光源部２０から出射
し、前記導光板１０にその入射端面１０ａから入射した
光を、図１および図２に矢線で示したように、導光板前
面１０ｂと外気（空気）との界面での全反射と、導光板
後面１０ｃに設けられた反射膜１１での反射の繰り返し
により導光板１０の長さ方向に導きながら、導光板前面
１０ｂと外気との界面に対して全反射臨界角より小さい
（垂直に近い）入射角で入射した光を導光板前面１０ｂ
から出射する。The surface light source emits light emitted from the light source unit 20 and incident on the light guide plate 10 from its incident end face 10a to the light guide plate front face 10b as shown by arrows in FIGS. The interface between the front surface 10b of the light guide plate and the outside air while being guided in the length direction of the light guide plate 10 by repeating the total reflection at the interface with the outside air (air) and the reflection on the reflection film 11 provided on the rear surface 10c of the light guide plate. Incident on the light guide plate front surface 10b at an incident angle smaller than the total reflection critical angle (closer to the vertical).
Emitted from
【００２５】その場合、この実施例の面光源は、前記導
光板１０の入射端面１０ａに、前記入射端面１０ａの高
さ方向に並ぶ複数のプリズム面１２ａからなる屈折面１
２を設けたものであるため、前記光源部２０から出射
し、前記導光板１０にその入射端面１０ａから入射する
光が、前記入射端面１０ａに設けられた屈折面１２によ
り導光板１０の前面１０ｂの法線に対して角度が小さく
なる方向に屈折されて導光板１０に入射する。In this case, the surface light source of this embodiment is a refraction surface 1 comprising a plurality of prism surfaces 12a arranged on the incident end face 10a of the light guide plate 10 in the height direction of the incident end face 10a.
2, the light emitted from the light source unit 20 and incident on the light guide plate 10 from the incident end face 10a thereof is transmitted to the front surface 10b of the light guide plate 10 by the refraction surface 12 provided on the incident end face 10a. Is refracted in a direction in which the angle becomes smaller with respect to the normal line and enters the light guide plate 10.
【００２６】そのため、この面光源によれば、前記導光
板１０にその入射端面１０ａから入射してこの導光板１
０内を導かれる光を、導光板前面１０ｂの入射端面付近
の領域にも全反射臨界角より小さい入射角で入射させ、
導光板前面１０ｂの入射端面付近の領域からも充分な量
の光を出射させることができ、したがって、導光板１０
の前面全体からほぼ均一な強度の光を出射することがで
きる。Therefore, according to the surface light source, the light is incident on the light guide plate 10 from the incident end face 10a of the light guide plate 10.
The light guided inside 0 is also incident on a region near the incident end face of the light guide plate front surface 10b at an incident angle smaller than the critical angle for total reflection,
A sufficient amount of light can be emitted from a region near the incident end face of the light guide plate front surface 10b.
Can emit light of substantially uniform intensity from the entire front surface of the light emitting element.
【００２７】このように、上記面光源は、導光板１０の
前面全体からほぼ均一な強度の光を出射するため、例え
ば液晶表示装置の光源に上記面光源を使用することによ
り、画面全体の輝度が均一な良好な表示品質の液晶表示
装置を得ることができる。As described above, since the surface light source emits light of substantially uniform intensity from the entire front surface of the light guide plate 10, for example, by using the surface light source as a light source of a liquid crystal display device, the brightness of the entire screen is improved. , A liquid crystal display device having a good display quality and uniform display quality can be obtained.
【００２８】図３は上記実施例の面光源を備えた液晶表
示装置の側面図であり、この液晶表示装置は、液晶表示
素子３０の後側に、上記実施例の面光源を、その導光板
１０の前面１０ｂを前記液晶表示素子３０の後面に対向
させて配置したバックライト型のものである。FIG. 3 is a side view of the liquid crystal display device provided with the surface light source of the above embodiment. In this liquid crystal display device, the surface light source of the above embodiment is provided behind the liquid crystal display element 30 and the light guide plate thereof. 10 is a backlight type in which a front surface 10 b of the liquid crystal display 10 is opposed to a rear surface of the liquid crystal display element 30.
【００２９】なお、前記液晶表示素子３０は、ＴＮ（ツ
イステッドネマティック）型、ＳＴＮ（スーパーツイス
テッドネマティック）型、液晶分子を一方向にホモジニ
アスさせたホモジニアス配向型のいずれかの液晶表示素
子、あるいは強誘電性または反強誘電性液晶表示素子で
あり、具体的な構造は図示しないが、液晶層を挟んで対
向する前後一対の透明基板の内面にそれぞれ透明電極が
設けられた液晶セル３１と、この液晶セル３１の前面と
後面とに配置された一対の偏光板３２，３３とからなっ
ている。The liquid crystal display element 30 may be any of a TN (twisted nematic) type, an STN (super twisted nematic) type, a homogeneous alignment type in which liquid crystal molecules are homogenized in one direction, or a ferroelectric liquid crystal display element. A liquid crystal cell 31 in which transparent electrodes are respectively provided on inner surfaces of a pair of front and rear transparent substrates opposed to each other with a liquid crystal layer interposed therebetween, The cell 31 includes a pair of polarizing plates 32 and 33 disposed on the front and rear surfaces of the cell 31, respectively.
【００３０】この液晶表示装置は、充分な明るさの環境
下ではその環境の光である外光を利用する反射表示を行
ない、充分な明るさの外光が得られないときに、面光源
から照明光を出射させてその照明光を利用する透過表示
を行なうものであり、外光を利用する反射表示のとき
は、表示の観察側である前側から入射し、前記液晶表示
素子３０を透過した光が、図に破線の矢線で示したよう
に前記面光源の導光板１０の後面１０ｃに設けられた反
射膜１１により反射され、その反射光が前記液晶表示素
子３０を透過して前側に出射する。This liquid crystal display device performs reflection display using the external light which is the light of the environment under the environment of sufficient brightness, and when the external light of sufficient brightness cannot be obtained, the surface light source The illumination light is emitted to perform transmissive display using the illumination light. In the case of reflective display using external light, light enters from the front side, which is the display observation side, and passes through the liquid crystal display element 30. Light is reflected by a reflective film 11 provided on a rear surface 10c of the light guide plate 10 of the surface light source as indicated by a dashed arrow in the figure, and the reflected light is transmitted through the liquid crystal display element 30 to the front side. Emit.
【００３１】また、前記照明光を利用する透過表示のと
きは、前記面光源から出射した照明光が図に実線の矢線
で示したように前記液晶表示素子３０にその後面から入
射し、この液晶表示素子３０を透過した光が前側に出射
する。In the case of the transmissive display using the illumination light, the illumination light emitted from the surface light source enters the liquid crystal display element 30 from the rear surface as shown by a solid arrow in FIG. Light transmitted through the liquid crystal display element 30 is emitted to the front side.
【００３２】なお、上記実施例の面光源は、導光板１０
の後面１０ｃに反射膜１１を設けたものであるが、前記
導光板１０の後面１０ｃの反射膜１１は省略してもよ
く、その場合も、光源部２０から出射し、前記導光板１
０にその入射端面１０ａから入射した光を、導光板前面
１０ｂと外気との界面での全反射と、導光板後面１０ｃ
と外気との界面での全反射の繰り返しにより導光板１０
の長さ方向に導きながら、導光板前面１０ｂから出射す
ることができる。The surface light source of the above embodiment is a light guide plate 10
Although the reflection film 11 is provided on the rear surface 10c of the light guide plate 10, the reflection film 11 on the rear surface 10c of the light guide plate 10 may be omitted.
Light from the incident end face 10a is totally reflected at the interface between the front surface 10b of the light guide plate and the outside air and the rear surface 10c of the light guide plate.
Light guide plate 10 by repeating total internal reflection at the interface between
The light can be emitted from the front surface 10b of the light guide plate while being guided in the length direction.
【００３３】このように導光板１０の後面１０ｃの反射
膜１１を省略した面光源は、図３に示した反射表示と透
過表示とを行なうバックライト型の液晶表示装置に限ら
ず、常に面光源からの照明光を利用する透過表示を行な
うバックライト型の液晶表示装置にも、またフロントラ
イト型の液晶表示装置にも使用することができる。The surface light source in which the reflection film 11 on the rear surface 10c of the light guide plate 10 is omitted as described above is not limited to the backlight type liquid crystal display device performing the reflection display and the transmission display shown in FIG. The present invention can be used for a backlight type liquid crystal display device which performs a transmissive display using illumination light from a camera, and a front light type liquid crystal display device.
【００３４】図４は、導光板１０の後面１０ｃの反射膜
１１を省略した面光源を備えたフロントライト型の液晶
表示装置の側面図であり、この液晶表示装置は、液晶表
示素子３０の前側に、上記実施例の面光源を、その導光
板１０の前面１０ｂを前記液晶表示素子３０の前面に対
向させて配置するとともに、前記液晶表示素子３０の後
側に反射板３４を配置した構成となっている。なお、前
記液晶表示素子３０は図３に示したものと同じものであ
る。FIG. 4 is a side view of a front light type liquid crystal display device provided with a surface light source in which the reflection film 11 on the rear surface 10c of the light guide plate 10 is omitted. In addition, the surface light source of the above embodiment is arranged such that the front surface 10b of the light guide plate 10 is opposed to the front surface of the liquid crystal display element 30 and the reflection plate 34 is arranged behind the liquid crystal display element 30. Has become. The liquid crystal display element 30 is the same as that shown in FIG.
【００３５】この液晶表示装置は、充分な明るさの環境
下ではその環境の光である外光を利用する反射表示を行
ない、充分な明るさの外光が得られないときに、面光源
から照明光を出射させてその照明光を利用する反射表示
を行なうものであり、外光を利用する反射表示のとき
は、表示の観察側である前側から入射し、前記面光源の
導光板１０と前記液晶表示素子３０とを透過した光が図
に破線の矢線で示したように反射板３４により反射さ
れ、その反射光が前記液晶表示素子３０と前記面光源の
導光板１０とを透過して前側に出射する。This liquid crystal display device performs reflection display using external light which is the light of the environment under an environment of sufficient brightness, and when the external light of sufficient brightness cannot be obtained, the liquid crystal display device transmits from the surface light source. The illumination light is emitted to perform reflection display using the illumination light. In the case of reflection display using external light, light is incident from the front side, which is the display observation side, and the light guide plate 10 of the surface light source is The light transmitted through the liquid crystal display element 30 is reflected by a reflector 34 as shown by a broken arrow in the figure, and the reflected light is transmitted through the liquid crystal display element 30 and the light guide plate 10 of the surface light source. Out to the front side.
【００３６】また、前記照明光を利用する反射表示のと
きは、前記面光源から出射した照明光が図に実線の矢線
で示したように前記液晶表示素子３０にその前面から入
射し、この液晶表示素子３０を透過した光が前記反射板
３４により反射され、その反射光が前記液晶表示素子３
０と前記面光源の導光板１０とを透過して前側に出射す
る。In the case of reflection display using the illumination light, the illumination light emitted from the surface light source enters the liquid crystal display element 30 from the front as shown by a solid arrow in FIG. The light transmitted through the liquid crystal display element 30 is reflected by the reflection plate 34, and the reflected light is reflected by the liquid crystal display element 3
0 and the light passes through the light guide plate 10 of the surface light source and is emitted to the front side.
【００３７】図５はこの発明の第２の実施例を示す面光
源の側面図であり、この実施例の面光源は、上述した第
１の実施例の面光源に、光源部２０からの出射光を直線
偏光光として導光板１０に入射させるための偏光板２３
を付加したものである。なお、前記偏光板２３は、前記
光源部２０のリフレクタ２２の開口部に嵌め込まれてい
る。FIG. 5 is a side view of a surface light source according to a second embodiment of the present invention. Polarizing plate 23 for causing the emitted light to enter the light guide plate 10 as linearly polarized light
Is added. The polarizing plate 23 is fitted into an opening of the reflector 22 of the light source unit 20.
【００３８】この実施例の面光源は、光源部２０からの
出射光を直線偏光光として導光板１０に入射させるため
の偏光板２３を備えているため、前記導光板１０の前面
全体から、ほぼ均一な強度で、しかも前記偏光板２３の
透過軸（図示せず）に沿った偏光成分の直線偏光光を出
射することができる。The surface light source of this embodiment is provided with the polarizing plate 23 for allowing the light emitted from the light source unit 20 to enter the light guide plate 10 as linearly polarized light. It is possible to emit linearly polarized light having a uniform intensity and a polarization component along the transmission axis (not shown) of the polarizing plate 23.
【００３９】この実施例の面光源は、上記図３および図
４に示したいずれの液晶表示装置にも使用できるもので
あり、この面光源を図３に示したバックライト型の液晶
表示装置に使用する場合は、前記偏光板２３の透過軸の
向きを、導光板１０の前面から、液晶表示素子３０の後
側偏光板３３の透過軸に沿った偏光成分の直線偏光光を
出射させるように設定すればよい。The surface light source of this embodiment can be used in any of the liquid crystal display devices shown in FIGS. 3 and 4. This surface light source can be used in the backlight type liquid crystal display device shown in FIG. When used, the direction of the transmission axis of the polarizing plate 23 is set so that linearly polarized light having a polarization component along the transmission axis of the rear polarizing plate 33 of the liquid crystal display element 30 is emitted from the front surface of the light guide plate 10. Just set it.
【００４０】この実施例の面光源を備えたバックライト
型の液晶表示装置は、前記面光源から液晶表示素子３０
の後側偏光板３３の透過軸に沿った偏光成分の直線偏光
光が出射し、その光が前記後側偏光板３３を透過して液
晶セル３１に入射するため、前記液晶セル３１に偏光度
の高い直線偏光光を入射させ、よりコントラストの高い
表示を得ることができる。The backlight type liquid crystal display device provided with the surface light source according to this embodiment comprises a liquid crystal display element 30 from the surface light source.
The linearly polarized light of the polarization component along the transmission axis of the rear polarizing plate 33 is emitted, and the light is transmitted through the rear polarizing plate 33 and enters the liquid crystal cell 31. And a display with higher contrast can be obtained.
【００４１】なお、この実施例の面光源を備えたバック
ライト型の液晶表示装置は、前記液晶表示素子３０の後
側偏光板３３を省略し、前記面光源から出射した直線偏
光光をそのまま液晶セル３１に入射させる構成としても
よい。In the backlight type liquid crystal display device provided with the surface light source of this embodiment, the rear polarizing plate 33 of the liquid crystal display element 30 is omitted, and the linearly polarized light emitted from the surface light source is converted to the liquid crystal. A configuration in which the light enters the cell 31 may be employed.
【００４２】また、この実施例の面光源を図４に示した
フロントライト型の液晶表示装置に使用する場合は、前
記偏光板２３の透過軸を向きを、導光板１０の前面か
ら、液晶表示素子３０の前側偏光板３２の透過軸に沿っ
た偏光成分の直線偏光光を出射させるように設定すれば
よい。When the surface light source of this embodiment is used in the front light type liquid crystal display device shown in FIG. 4, the transmission axis of the polarizing plate 23 is oriented from the front of the light guide plate 10 to the liquid crystal display. What is necessary is just to set so that the linearly polarized light of the polarization component along the transmission axis of the front polarizing plate 32 of the element 30 may be emitted.
【００４３】この実施例の面光源を備えたフロントライ
ト型の液晶表示装置は、前記面光源から液晶表示素子３
０の前側偏光板３２の透過軸に沿った偏光成分の直線偏
光光が出射し、その光が前記前側偏光板３３を透過して
液晶セル３１に入射するため、前記液晶セル３１に偏光
度の高い直線偏光光を入射させ、よりコントラストの高
い表示を得ることができる。The front light type liquid crystal display device provided with the surface light source according to this embodiment comprises a liquid crystal display element 3 from the surface light source.
0, a linearly polarized light having a polarization component along the transmission axis of the front polarizing plate 32 is emitted, and the light is transmitted through the front polarizing plate 33 and enters the liquid crystal cell 31. High linearly polarized light is incident, and a display with higher contrast can be obtained.
【００４４】図６〜図８はそれぞれこの発明の第３〜第
５の実施例を示す面光源の側面図であり、これらの実施
例の面光源は、上述した第１の実施例の面光源の導光板
１０の前面１０ｂの前側に、前記導光板１０の前面１０
ｂから出射した光を所定の方向に屈折させる光学手段を
配置したものである。FIGS. 6 to 8 are side views of surface light sources showing the third to fifth embodiments of the present invention. The surface light sources of these embodiments are the same as those of the first embodiment described above. The front surface 10 b of the light guide plate 10 is provided in front of the front surface 10 b of the light guide plate 10.
The optical means for refracting the light emitted from b in a predetermined direction is arranged.
【００４５】すなわち、図６に示した第３の実施例の面
光源は、第１の実施例の面光源の導光板１０の前面１０
ｂの前側に、拡散板２５と前記拡散板２５の前側に設け
られた正面方向に指向性を有する集光板２６とからなる
光学手段２４ａを配置したものである。That is, the surface light source of the third embodiment shown in FIG. 6 is the same as the surface light source of the surface light source plate 10 of the first embodiment.
b, an optical unit 24a including a diffusion plate 25 and a light-collecting plate 26 provided in front of the diffusion plate 25 and having directivity in the front direction is arranged.
【００４６】なお、前記拡散板２５は、例えば拡散粒子
が混入された透明樹脂フィルムからなっており、前記集
光板２６は、前面に前記導光板１０の幅方向に沿う細長
い二等辺三角形状のプリズム部が密に並べて互いに平行
に形成されたプリズムシートからなっている。The diffusing plate 25 is made of, for example, a transparent resin film into which diffusing particles are mixed. The condensing plate 26 has an elongated isosceles triangular prism along the width direction of the light guide plate 10 on the front surface. The parts are composed of prism sheets that are closely arranged and formed in parallel with each other.
【００４７】この実施例の面光源によれば、前記導光板
１０の前面１０ｂから出射した光を前記拡散板２５によ
り拡散させるとともに、その拡散光を前記集光板２６に
より正面方向（導光板１０の前面１０ｂの法線付近の方
向）に集光させて出射することができるため、強度分布
がより均一で、しかも正面方向に指向性をもった光を出
射することができる。According to the surface light source of this embodiment, the light emitted from the front surface 10b of the light guide plate 10 is diffused by the diffusion plate 25, and the diffused light is diffused by the light collector 26 in the front direction (of the light guide plate 10). Since the light can be condensed and emitted in the direction near the normal line of the front surface 10b), light with more uniform intensity distribution and directivity in the front direction can be emitted.
【００４８】また、図７に示した第４の実施例の面光源
は、第１の実施例の面光源の導光板１０の前面１０ｂの
前側に、正面方向に指向性を有する光屈折板２７からな
る光学手段２４ｂを配置したものである。The surface light source according to the fourth embodiment shown in FIG. 7 has a light refraction plate 27 having directivity in the front direction provided in front of the front surface 10b of the light guide plate 10 of the surface light source according to the first embodiment. The optical means 24b is arranged.
【００４９】なお、前記光屈折板２７は、前記導光板１
０の前面１０ｂに対向する後面に、前記導光板１０の幅
方向に沿う細長い二等辺三角形状のプリズム部が密に並
べて互いに平行に形成されたプリズムシートからなって
いる。The light refraction plate 27 is provided on the light guide plate 1.
On the rear surface facing the front surface 10b of the light guide plate 10, a prism sheet in which elongated isosceles triangular prism portions along the width direction of the light guide plate 10 are densely arranged and formed parallel to each other.
【００５０】この実施例の面光源によれば、前記導光板
１０の前面１０ｂから出射した光を前記光屈折板２７に
より正面方向に屈折させて出射することができるため、
強度分布が均一で、しかも正面方向に指向性をもった光
を出射することができる。According to the surface light source of this embodiment, the light emitted from the front surface 10b of the light guide plate 10 can be refracted in the front direction by the light refraction plate 27 and emitted.
Light having uniform intensity distribution and directivity in the front direction can be emitted.
【００５１】また、図８に示した第５の実施例の面光源
は、第１の実施例の面光源の導光板１０の前面１０ｂの
前側に、正面方向に対して斜め方向に指向性を有する光
屈折板２８からなる光学手段２４ｃを配置したものであ
る。The surface light source of the fifth embodiment shown in FIG. 8 has a directivity obliquely to the front of the front surface 10b of the light guide plate 10 of the surface light source of the first embodiment. The optical means 24c comprising a light refraction plate 28 is provided.
【００５２】なお、前記光屈折板２８は、前面に、前記
導光板１０の幅方向に沿う細長い不等辺三角形状のプリ
ズム部が密に並べて互いに平行に形成された鋸歯状プリ
ズムシートからなっている。The light refracting plate 28 is formed of a sawtooth-shaped prism sheet on the front surface of which is formed in parallel with each other elongated narrow trapezoidal prisms along the width direction of the light guide plate 10. .
【００５３】この実施例の面光源によれば、前記導光板
１０の前面１０ｂから出射した光を前記光屈折板２８に
より正面方向に対して斜め方向に屈折させて出射するこ
とができるため、強度分布が均一で、しかも斜め方向に
指向性をもった光を出射することができる。According to the surface light source of this embodiment, light emitted from the front surface 10b of the light guide plate 10 can be refracted by the light refraction plate 28 in the oblique direction with respect to the front direction and emitted. Light with uniform distribution and directivity in oblique directions can be emitted.
【００５４】なお、上記第３〜第５の実施例の面光源
は、導光板１０の後面１０ｃに反射膜１１を設けたもの
であるが、前記導光板１０の後面１０ｃの反射膜１１は
省略してもよい。In the surface light sources of the third to fifth embodiments, the reflection film 11 is provided on the rear surface 10c of the light guide plate 10, but the reflection film 11 on the rear surface 10c of the light guide plate 10 is omitted. May be.
【００５５】また、上記第１〜第５の実施例の面光源
は、導光板１０の入射端面１０ａに、前記入射端面１０
ａの高さ方向に並ぶ複数の横長プリズム面１２ａからな
る屈折面１３を設けたものであるが、導光板１０の入射
端面１０ａに設ける屈折面は、光源部２０からの出射光
を導光板１０の前面１０ｂの法線に対する角度が小さく
なる方向に屈折させて前記導光板１０に入射させるもの
であれば、例えば、前記入射端面１０ａの高さ方向に並
ぶ複数の横長レンズ面からなる屈折面でも、また、前記
入射端面１０ａの高さ方向および長さ方向に並ぶ複数の
角錐状プリズム面または球面状レンズ面からなる屈折面
でもよい。The surface light sources of the first to fifth embodiments are arranged such that the incident end face 10a of the light guide plate 10 is
The light guide plate 10 is provided with a refraction surface 13 composed of a plurality of horizontally long prism surfaces 12a arranged in the height direction, and the refraction surface provided on the incident end face 10a of the light guide plate 10 transmits light emitted from the light source unit 20 to the light guide plate 10a. If the light is refracted in a direction in which the angle with respect to the normal line of the front surface 10b becomes smaller and is incident on the light guide plate 10, for example, a refracting surface composed of a plurality of horizontally long lens surfaces arranged in the height direction of the incident end face 10a may be used. Further, a refracting surface composed of a plurality of pyramidal prism surfaces or spherical lens surfaces arranged in the height direction and the length direction of the incident end face 10a may be used.
【００５６】図９および図１０はこの発明の第６の実施
例を示しており、図９は面光源の側面図、図１０は前記
面光源の導光板の入射端面側の拡大側面図である。9 and 10 show a sixth embodiment of the present invention. FIG. 9 is a side view of a surface light source, and FIG. 10 is an enlarged side view of a light guide plate of the surface light source on the side of an incident end face. .
【００５７】この実施例の面光源は、導光板１０の入射
端面１０ａをほぼ垂直な面とし、前記導光板１０の前面
１０ｂおよび後面１０ｃの入射端面１０ａ側の端部にそ
れぞれ、光源部２０から出射し、前記導光板１０に前記
入射端面１０ａから入射した光を前記導光板１０の前面
１０ｂの法線に対する角度が小さくなる方向に屈折させ
る屈折面１３，１４を形成したものであり、他の構成
は、上記第１の実施例の面光源と同じである。In the surface light source of this embodiment, the incident end face 10a of the light guide plate 10 is set to be a substantially vertical surface, and the front end 10b and the rear end face 10c of the light guide plate 10 are respectively connected to the ends on the side of the incident end face 10a from the light source section 20. The light guide plate 10 is provided with refraction surfaces 13 and 14 for refracting light incident on the light guide plate 10 from the incident end face 10a in a direction in which the angle with respect to the normal line of the front surface 10b of the light guide plate 10 becomes smaller. The configuration is the same as the surface light source of the first embodiment.
【００５８】この実施例の面光源において、前記導光板
１０の前面１０ｂの入射端面１０ａ側の端部に形成され
た屈折面１３は、導光板前面１０ｂに対し、前記入射端
面１０ａから導光板１０の他端方向に向かって導光板１
０の内部方向に斜めに凹入する傾斜面からなっており、
また、前記導光板１０の後面１０ｃの入射端面１０ａ側
の端部に形成された屈折面１４は、導光板後面１０ｃに
対し、前記入射端面１０ａから導光板１０の他端方向に
向かって導光板１０の内部方向に斜めに凹入する傾斜面
からなっている。In the surface light source of this embodiment, the refraction surface 13 formed at the end of the front surface 10b of the light guide plate 10 on the side of the incident end surface 10a is different from the light guide plate front surface 10b from the incident end surface 10a. Light guide plate 1 toward the other end of the
It is composed of an inclined surface that is obliquely recessed in the inner direction of 0,
Further, a refraction surface 14 formed at an end of the rear surface 10c of the light guide plate 10 on the side of the incident end surface 10a is provided on the light guide plate rear surface 10c from the incident end surface 10a toward the other end of the light guide plate 10. 10 is formed of an inclined surface which is obliquely recessed in the inner direction.
【００５９】この実施例の面光源は、導光板１０の前面
１０ｂと後面１０ｃの入射端面１０ａ側の端部にそれぞ
れ、前記入射端面１０ａから導光板１０の他端方向に向
かって導光板１０の内部方向に斜めに凹入する傾斜面か
らなる屈折面１３，１４を形成したものであるため、光
源部２０から出射し、導光板１０にその入射端面１０ａ
から入射した光のうち、前記導光板１０の前面１０ｂお
よび後面１０ｃの入射端面１０ａ側の端部に向かう光
が、図９および図１０矢線で示したように、前記屈折面
１３，１４と外気との界面で全反射され、前記導光板１
０の前面１０ｂの法線に対して角度が小さくなる方向に
屈折される。The surface light source of this embodiment is provided at the front end 10b and the rear end 10c of the light guide plate 10 on the side of the light incident end face 10a, respectively, from the light incident end face 10a toward the other end of the light guide plate 10. Since the refraction surfaces 13 and 14 are formed as inclined surfaces that are obliquely recessed in the internal direction, the light exits from the light source unit 20 and enters the light guide plate 10 at the incident end face 10 a.
Of the light incident on the front surface 10b and the rear surface 10c of the light guide plate 10 toward the incident end surface 10a side, as shown by arrows in FIGS. The light guide plate 1 is totally reflected at the interface with the outside air,
The light is refracted in a direction in which the angle becomes smaller with respect to the normal line of the front surface 10b of 0.
【００６０】そのため、この実施例の面光源によれば、
前記導光板１０にその入射端面１０ａから入射してこの
導光板１０内を導かれる光を、導光板前面１０ｂの入射
端面付近の領域にも全反射臨界角よりも小さい入射角で
入射させ、導光板前面１０ｂの入射端面付近の領域から
も充分な量の光を出射することができ、したがって、導
光板の前面全体からほぼ均一な強度の光を出射すること
ができる。導光板１０の前面全体からほぼ均一な強度の
光を出射することができる。Therefore, according to the surface light source of this embodiment,
Light incident on the light guide plate 10 from the incident end face 10a and guided through the light guide plate 10 is also incident on a region near the incident end face of the front face 10b of the light guide plate at an incident angle smaller than the critical angle for total reflection. A sufficient amount of light can be emitted from a region near the incident end face of the light plate front surface 10b, and therefore, light with substantially uniform intensity can be emitted from the entire front surface of the light guide plate. Light with substantially uniform intensity can be emitted from the entire front surface of the light guide plate 10.
【００６１】なお、この実施例では、導光板１０の前面
１０ｂおよび後面１０ｃの入射端面１０ａ側の端部に、
前記入射端面１０ａから導光板１０の他端方向に向かっ
て導光板１０の内部方向に斜めに凹入する傾斜面からな
る屈折面１３，１４を形成しているが、前記導光板１０
の前面１０ｂおよび後面１０ｃの入射端面１０ａ側の端
部に形成する屈折面は、光源部２０から出射し、前記導
光板１０に前記入射端面１０ａから入射した光を前記導
光板１０の前面１０ｂの法線に対する角度が小さくなる
方向に屈折させる面であれば、曲面状の屈折面としても
よい。In this embodiment, the front end 10b and the rear end 10c of the light guide plate 10 are provided at the ends on the incident end face 10a side.
The refraction surfaces 13 and 14 are formed as inclined surfaces that are obliquely recessed inwardly of the light guide plate 10 from the incident end face 10 a toward the other end of the light guide plate 10.
The front surface 10b and the rear surface 10c of the front surface 10b are formed with refraction surfaces formed at the end portions on the side of the incident end surface 10a. As long as the surface is refracted in a direction in which the angle with respect to the normal decreases, the surface may be a curved refraction surface.
【００６２】また、この実施例では、導光板１０の前面
１０ｂと後面１０ｃの入射端面１０ａ側の端部にそれぞ
れ前記屈折面１３，１４を形成しているが、光源部２０
から出射し、前記導光板１０に前記入射端面１０ａから
入射した光を前記導光板１０の前面１０ｂの法線に対す
る角度が小さくなる方向に屈折させる屈折面は、前記導
光板１０の前面１０ｂと後面１０ｃとのうちのいずれか
一方の面だけに形成してもよい。In this embodiment, the refraction surfaces 13 and 14 are formed at the front end 10b and the rear end 10c of the light guide plate 10 on the incident end surface 10a side, respectively.
The light refracting surface that refracts light emitted from the light guide plate 10 from the incident end face 10a in a direction in which the angle with respect to the normal line of the front surface 10b of the light guide plate 10 becomes smaller is a front surface 10b and a rear surface of the light guide plate 10 10c may be formed only on one of the surfaces.
【００６３】さらに、この実施例の面光源は、導光板１
０の後面１０ｃに反射膜１１を設けたものであるが、前
記導光板１０の後面１０ｃの反射膜１１は省略してもよ
い。Further, the surface light source of this embodiment is a light guide plate 1
Although the reflective film 11 is provided on the rear surface 10c of the light guide plate 10, the reflective film 11 on the rear surface 10c of the light guide plate 10 may be omitted.
【００６４】また、この実施例の面光源は、図６〜図８
に示した第３〜第５の実施例の面光源装置と同様に、導
光板１０の前面１０ｂの前側に前記導光板１０の前面１
０ｂから出射した光を所定の方向に屈折させる光学手段
２４ａ，２４ｂ，２４ｃを配置した構成としてもよく、
このようにすることにより、強度分布が均一で、しかも
所定の方向に指向性をもった光を出射することができ
る。The surface light source of this embodiment is shown in FIGS.
In the same manner as the surface light source devices of the third to fifth embodiments shown in FIG. 3, the front surface 1b of the light guide plate 10 is provided in front of the front surface 10b of the light guide plate 10.
Optical means 24a, 24b, 24c for refracting light emitted from Ob in a predetermined direction may be arranged.
This makes it possible to emit light having a uniform intensity distribution and directivity in a predetermined direction.
【００６５】[0065]
【発明の効果】この発明の面光源は、導光板の入射端面
に、光源部からの出射光を前記導光板の前面の法線に対
して角度が小さくなる方向に屈折させて前記導光板に入
射させるための屈折面を設けたものであるため、前記導
光板の前面全体からほぼ均一な強度の光を出射すること
ができる。According to the surface light source of the present invention, the light emitted from the light source section is refracted at the incident end face of the light guide plate in a direction in which the angle becomes smaller with respect to the normal to the front surface of the light guide plate, and the light is transmitted to the light guide plate. Since the refraction surface for incidence is provided, light of substantially uniform intensity can be emitted from the entire front surface of the light guide plate.
【００６６】この面光源において、前記導光板の入射端
面に設けられた屈折面は、前記入射端面の高さ方向に並
ぶ複数のプリズム面またはレンズ面からなっているのが
好ましく、このような屈折面を設けることにより、前記
光源部からの出射光を前記導光板の前面の法線に対して
角度が小さくなる方向に屈折させて前記導光板に入射さ
せることができる。In this surface light source, the refracting surface provided on the incident end face of the light guide plate preferably comprises a plurality of prism faces or lens faces arranged in the height direction of the incident end face. By providing the surface, the light emitted from the light source unit can be refracted in a direction in which the angle becomes smaller with respect to the normal to the front surface of the light guide plate and can be incident on the light guide plate.
【００６７】また、この発明の他の面光源は、前記導光
板の前面と後面とのうちの少なくとも一方の面の入射端
面側の端部に、光源部から出射し、前記導光板に前記入
射端面から入射した光を前記導光板の前面の法線に対し
て角度が小さくなる方向に屈折させる屈折面を形成した
ものであるため、前記導光板の前面全体からほぼ均一な
強度の光を出射することができる。Further, another surface light source of the present invention emits light from a light source at an end of at least one of a front surface and a rear surface of the light guide plate on an incident end surface side, and the light incident on the light guide plate. Since a refraction surface that refracts light incident from an end face in a direction in which an angle becomes smaller with respect to a normal to the front surface of the light guide plate is formed, light of substantially uniform intensity is emitted from the entire front surface of the light guide plate. can do.
【００６８】この面光源において、前記導光板の前面と
後面の少なくとも一方の面の入射端面側の端部に形成さ
れた前記屈折面は、この屈折面が形成された前記面に対
し、前記入射端面から前記導光板の他端方向に向かって
前記導光板の内部方向に斜めに凹入する傾斜面からなっ
ているのが好ましく、このような屈折面を形成すること
により、前記光源部から出射し、前記導光板に前記入射
端面から入射した光を前記導光板の前面の法線に対して
角度が小さくなる方向に屈折させることができる。In this surface light source, the refracting surface formed on the incident end surface side of at least one of the front surface and the rear surface of the light guide plate is configured such that the incident light is incident on the surface on which the refracting surface is formed. The light guide plate preferably has an inclined surface that is obliquely recessed in the interior direction of the light guide plate from the end surface toward the other end of the light guide plate. By forming such a refraction surface, light is emitted from the light source unit. Then, the light incident on the light guide plate from the incident end face can be refracted in a direction in which the angle becomes smaller with respect to the normal to the front surface of the light guide plate.
【００６９】また、この発明のいずれの面光源も、前記
導光板の前面の前側に、前記導光板の前面から出射した
光を所定の方向に屈折させる光学手段が配置された構成
のものが好ましく、このようにすることにより、強度分
布が均一で、しかも所定の方向に指向性をもった光を出
射することができる。Also, any surface light source of the present invention preferably has a structure in which an optical means for refracting light emitted from the front surface of the light guide plate in a predetermined direction is disposed in front of the front surface of the light guide plate. In this manner, light having a uniform intensity distribution and directivity in a predetermined direction can be emitted.
【図１】この発明の第１の実施例を示す面光源の側面
図。FIG. 1 is a side view of a surface light source according to a first embodiment of the present invention.
【図２】第１の実施例の面光源の導光板の入射端面側の
拡大側面図。FIG. 2 is an enlarged side view of the light guide plate of the surface light source of the first embodiment on the incident end face side.
【図３】第１の実施例の面光源を備えたバックライト型
液晶表示装置の側面図。FIG. 3 is a side view of a backlight type liquid crystal display device including the surface light source according to the first embodiment.
【図４】第１の実施例の面光源から導光板の後面の反射
膜を省略した面光源を備えたフロントライト型液晶表示
装置の側面図。FIG. 4 is a side view of a front light type liquid crystal display device provided with a surface light source in which the reflection film on the rear surface of the light guide plate is omitted from the surface light source of the first embodiment.
【図５】この発明の第２の実施例を示す面光源の側面
図。FIG. 5 is a side view of a surface light source according to a second embodiment of the present invention.
【図６】この発明の第３の実施例を示す面光源の側面
図。FIG. 6 is a side view of a surface light source according to a third embodiment of the present invention.
【図７】この発明の第４の実施例を示す面光源の側面
図。FIG. 7 is a side view of a surface light source according to a fourth embodiment of the present invention.
【図８】この発明の第５の実施例を示す面光源の側面
図。FIG. 8 is a side view of a surface light source according to a fifth embodiment of the present invention.
【図９】この発明の第６の実施例を示す面光源の側面
図。FIG. 9 is a side view of a surface light source according to a sixth embodiment of the present invention.
【図１０】第６の実施例の面光源の導光板の入射端面側
の拡大側面図。FIG. 10 is an enlarged side view of an incident end face side of a light guide plate of a surface light source according to a sixth embodiment.
【図１１】従来の面光源の側面図FIG. 11 is a side view of a conventional surface light source.
１０…導光板 １０ａ…入射端面 １０ｂ…前面 １０ｃ…後面 １１…反射膜 １２…屈折面 １２ａ…プリズム面 １３，１４…屈折面 ２０…光源部 ２４ａ，２４ｂ，２４ｃ…光学手段 ２５…拡散板 ２６…集光板 ２７，２８…光屈折板 DESCRIPTION OF SYMBOLS 10 ... Light guide plate 10a ... Incident end surface 10b ... Front surface 10c ... Back surface 11 ... Reflection film 12 ... Refraction surface 12a ... Prism surface 13, 14 ... Refraction surface 20 ... Light source part 24a, 24b, 24c ... Optical means 25 ... Diffusion plate 26 ... Light collectors 27, 28 ... light refractor
───────────────────────────────────────────────────── 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） Ｇ０２Ｆ 1/13357 Ｇ０２Ｆ 1/13357 // Ｆ２１Ｙ 103:00 Ｆ２１Ｙ 103:00 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme court ゛ (Reference) G02F 1/13357 G02F 1/13357 // F21Y 103: 00 F21Y 103: 00
Claims (5)
出射する前面およびこの前面と対向する後面とからなる
導光板と、前記導光板の入射端面に対向させて配置され
た光源部とからなり、前記導光板の入射端面に、前記光
源部からの出射光を前記導光板の前面の法線に対する角
度が小さくなる方向に屈折させて前記導光板に入射させ
るための屈折面が設けられていることを特徴とする面光
源。1. A light guide plate comprising an incident end face on which light is incident, a front face on which the incident light is emitted, and a rear face opposed to the front face, and a light source section disposed to face the incident end face of the light guide plate. A refraction surface is provided on the incident end face of the light guide plate, for refracting light emitted from the light source unit in a direction in which an angle with respect to a normal to the front surface of the light guide plate is reduced and allowing the light to enter the light guide plate. A surface light source characterized in that:
前記入射端面の高さ方向に並ぶ複数のプリズム面または
レンズ面からなっていることを特徴とする請求項１に記
載の面光源。2. A refracting surface provided on an incident end face of a light guide plate,
The surface light source according to claim 1, comprising a plurality of prism surfaces or lens surfaces arranged in the height direction of the incident end surface.
出射する前面およびこの前面と対向する後面とからなる
導光板と、前記導光板の入射端面に対向させて配置され
た光源部とからなり、前記導光板の前面と後面の少なく
とも一方の面の前記入射端面側の端部に、前記光源部か
ら出射し、前記導光板に前記入射端面から入射した光を
前記導光板の前面の法線に対する角度が小さくなる方向
に屈折させる屈折面が形成されていることを特徴とする
面光源。3. A light guide plate comprising an incident end face on which light is incident, a front face on which the incident light is emitted, and a rear face opposite to the front face, and a light source section disposed to face the incident end face of the light guide plate. And at least one of a front surface and a rear surface of the light guide plate, on the incident end surface side end, the light emitted from the light source unit, and the light incident on the light guide plate from the incident end surface is front surface of the light guide plate. A refracting surface for refracting light in a direction in which the angle with respect to the normal line becomes smaller.
の入射端面側の端部に形成された屈折面は、この屈折面
が形成された前記面に対し、前記入射端面から前記導光
板の他端方向に向かって前記導光板の内部方向に斜めに
凹入する傾斜面からなっていることを特徴とする請求項
３に記載の面光源。4. A refracting surface formed on an incident end surface side of at least one of a front surface and a rear surface of the light guide plate, wherein the refraction surface is formed on the light guide plate from the incident end surface with respect to the surface on which the refraction surface is formed. 4. The surface light source according to claim 3, wherein the surface light source comprises an inclined surface which is obliquely recessed in an inner direction of the light guide plate toward the other end of the light guide plate. 5.
から出射した光を所定の方向に屈折させる光学手段が配
置されていることを特徴とする請求項１または３に記載
の面光源。5. The surface according to claim 1, wherein an optical means for refracting light emitted from the front surface of the light guide plate in a predetermined direction is disposed in front of the front surface of the light guide plate. light source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001079089A JP2002279812A (en) | 2001-03-19 | 2001-03-19 | Surface light source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001079089A JP2002279812A (en) | 2001-03-19 | 2001-03-19 | Surface light source |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002279812A true JP2002279812A (en) | 2002-09-27 |
Family
ID=18935600
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001079089A Pending JP2002279812A (en) | 2001-03-19 | 2001-03-19 | Surface light source |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002279812A (en) |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7046317B2 (en) | 2003-03-31 | 2006-05-16 | Sharp Kabushiki Kaisha | Liquid crystal display apparatus |
| US9082353B2 (en) | 2010-01-05 | 2015-07-14 | Pixtronix, Inc. | Circuits for controlling display apparatus |
| US9087486B2 (en) | 2005-02-23 | 2015-07-21 | Pixtronix, Inc. | Circuits for controlling display apparatus |
| US9116344B2 (en) | 2008-10-27 | 2015-08-25 | Pixtronix, Inc. | MEMS anchors |
| US9128277B2 (en) | 2006-02-23 | 2015-09-08 | Pixtronix, Inc. | Mechanical light modulators with stressed beams |
| US9135868B2 (en) | 2005-02-23 | 2015-09-15 | Pixtronix, Inc. | Direct-view MEMS display devices and methods for generating images thereon |
| US9134552B2 (en) | 2013-03-13 | 2015-09-15 | Pixtronix, Inc. | Display apparatus with narrow gap electrostatic actuators |
| US9158106B2 (en) | 2005-02-23 | 2015-10-13 | Pixtronix, Inc. | Display methods and apparatus |
| US9176318B2 (en) | 2007-05-18 | 2015-11-03 | Pixtronix, Inc. | Methods for manufacturing fluid-filled MEMS displays |
| US9177523B2 (en) | 2005-02-23 | 2015-11-03 | Pixtronix, Inc. | Circuits for controlling display apparatus |
| US9229222B2 (en) | 2005-02-23 | 2016-01-05 | Pixtronix, Inc. | Alignment methods in fluid-filled MEMS displays |
| US9261694B2 (en) | 2005-02-23 | 2016-02-16 | Pixtronix, Inc. | Display apparatus and methods for manufacture thereof |
| US9336732B2 (en) | 2005-02-23 | 2016-05-10 | Pixtronix, Inc. | Circuits for controlling display apparatus |
| US9500853B2 (en) | 2005-02-23 | 2016-11-22 | Snaptrack, Inc. | MEMS-based display apparatus |
-
2001
- 2001-03-19 JP JP2001079089A patent/JP2002279812A/en active Pending
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7046317B2 (en) | 2003-03-31 | 2006-05-16 | Sharp Kabushiki Kaisha | Liquid crystal display apparatus |
| US7310122B2 (en) | 2003-03-31 | 2007-12-18 | Sharp Kabushiki Kaisha | Liquid crystal display apparatus |
| US9229222B2 (en) | 2005-02-23 | 2016-01-05 | Pixtronix, Inc. | Alignment methods in fluid-filled MEMS displays |
| US9261694B2 (en) | 2005-02-23 | 2016-02-16 | Pixtronix, Inc. | Display apparatus and methods for manufacture thereof |
| US9500853B2 (en) | 2005-02-23 | 2016-11-22 | Snaptrack, Inc. | MEMS-based display apparatus |
| US9135868B2 (en) | 2005-02-23 | 2015-09-15 | Pixtronix, Inc. | Direct-view MEMS display devices and methods for generating images thereon |
| US9336732B2 (en) | 2005-02-23 | 2016-05-10 | Pixtronix, Inc. | Circuits for controlling display apparatus |
| US9158106B2 (en) | 2005-02-23 | 2015-10-13 | Pixtronix, Inc. | Display methods and apparatus |
| US9087486B2 (en) | 2005-02-23 | 2015-07-21 | Pixtronix, Inc. | Circuits for controlling display apparatus |
| US9177523B2 (en) | 2005-02-23 | 2015-11-03 | Pixtronix, Inc. | Circuits for controlling display apparatus |
| US9274333B2 (en) | 2005-02-23 | 2016-03-01 | Pixtronix, Inc. | Alignment methods in fluid-filled MEMS displays |
| US9128277B2 (en) | 2006-02-23 | 2015-09-08 | Pixtronix, Inc. | Mechanical light modulators with stressed beams |
| US9176318B2 (en) | 2007-05-18 | 2015-11-03 | Pixtronix, Inc. | Methods for manufacturing fluid-filled MEMS displays |
| US9182587B2 (en) | 2008-10-27 | 2015-11-10 | Pixtronix, Inc. | Manufacturing structure and process for compliant mechanisms |
| US9116344B2 (en) | 2008-10-27 | 2015-08-25 | Pixtronix, Inc. | MEMS anchors |
| US9082353B2 (en) | 2010-01-05 | 2015-07-14 | Pixtronix, Inc. | Circuits for controlling display apparatus |
| US9134552B2 (en) | 2013-03-13 | 2015-09-15 | Pixtronix, Inc. | Display apparatus with narrow gap electrostatic actuators |
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