JP2002279812A - Surface light source - Google Patents

Surface light source

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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
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JP
Japan
Prior art keywords
surface
guide plate
light
light guide
front
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Pending
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JP2001079089A
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Japanese (ja)
Inventor
Yasuhiro Daiku
康宏 代工
Original Assignee
Casio Comput Co Ltd
カシオ計算機株式会社
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Application filed by Casio Comput Co Ltd, カシオ計算機株式会社 filed Critical Casio Comput Co Ltd
Priority to JP2001079089A priority Critical patent/JP2002279812A/en
Publication of JP2002279812A publication Critical patent/JP2002279812A/en
Application status is Pending legal-status Critical

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Abstract

PROBLEM TO BE SOLVED: To provide a surface light source enabled to emit a light with almost uniform strength from whole part of a light guide plate. SOLUTION: A refraction surface 12 which makes the light emitted from a light source part 20 is incident on a light guide plate 10 by refracting the light in such a direction that the angle between the refracted light and a normal line of a front surface 10b of a light guide plate 10 becomes smaller, is mounted to an end surface of incidence 10a of the light guide plate 10 composed of the end surface of incidence 10a into which the light is incident, the front surface 10b from which, the light of incidence is emitted, and a back surface 10c facing the front surface.

Description

【発明の詳細な説明】 DETAILED DESCRIPTION OF THE INVENTION

【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。 [Field of the Invention 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。 As a surface light source used in the light source or the like of the Related Art A liquid crystal display device, there is emitted from the front light emitted from the light source unit is guided by the light guide plate.

【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。 [0003] Figure 11 is a side view showing a conventional surface light source device, the surface light source, the surface 1c after the optical light is incident to the incident end face 1a which is incident faces the front 1b and the front 1b emits the light guide plate 1 consists of a light source disposed portion 3 which is opposed to the incident end face 1a of the light guide plate 1 and a.

【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。 [0004] The light guide plate 1, the front 1b is emitting surface is formed on a flat surface, a rear surface 1c is formed on the inclined surface inclined so as to approach the front 1b toward the other end from the incident end face 1a wedge-shaped transparent plate and consist (e.g. acrylic resin plate), the surface 1c after the light guide plate 1, the reflection film 2 is provided over its entire surface.

【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 Further, the light source unit 3 is, for example, cold cathode tubes 4 of the full-length over the length of the incident end face 1a of the light guide plate 1
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。 If, which is a light emitted from the cold cathode tubes 4 from the reflector 5 for reflecting 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。 [0006] The surface light source is emitted from the light source unit 3, the light incident from the incident end face 1a to the light guide plate 1, as indicated by arrows in FIG. 11, the light guide plate front 1b and the outside air (air) and the total reflection at the interface, while leading to the length direction of the light guide plate 1 by repeating reflection at the reflective film 2 provided on the light guide plate rear surface 1c, total reflection to the interface between the light guide plate front 1b and the outside air emits light incident at the critical angle is smaller than (nearly perpendicular) angle of incidence from the light guide plate front 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。 [SUMMARY OF THE INVENTION] However, the conventional surface light source shown in FIG. 11, of the light guided to the light guide plate 1 are incident from the incident end face 1a to the light guide plate 1, the light guide plate front 1b most, because it is totally reflected at an incident angle larger than the total reflection critical angle to the interface between the light guide plate front 1b and the outside air, the incident of the light guide plate front 1b of the light toward the region in the vicinity of the incident end face of the the intensity of light emitted from a region near the end surface is weaker than the intensity of the light emitted from the other regions, thus, there is unevenness in the intensity distribution of the emitted light.

【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。 [0008] The present invention is intended to provide a surface light source capable of emitting a substantially uniform intensity light from the entire front surface of the 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。 Means for Solving the Problems] The surface light source of the present invention, the front and the light guide plate comprising a rear surface of the front and opposite the light light is incident to the incident end face to be incident is emitted, the light guide plate to face the incident end surface consists of a light source disposed section, the incident end face of the light guide plate, the light emitted from the light source unit angle is refracted in a direction decreases for the front of the normal of the light guide plate it is characterized in that the refractive surface for causing incident on the light guide plate is provided.

【0010】この面光源によれば、光源部から出射し、 According to the surface light source, emitted from the light source unit,
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。 Light incident from the incident end face to the light guide plate, for incident is refracted in a direction in which the angle is reduced on the light guide plate with respect to the front surface normal of the light guide plate by the refractive surface provided on the incident end face, the light guide plate as the light guided to the light guide plate is incident from the incident end face, also in the area near the entrance end face of the light guide plate front is incident at the total reflection critical angle smaller than the incident angle, the area near the entrance end face of the light guide plate front surface also it can be emitted a sufficient amount of light from, therefore, it is possible to emit substantially uniform intensity light 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、 Further, another surface light source includes a front and a light guide plate comprising a rear surface of the front and opposite the light light is incident to the incident end face to be incident is emitted, the incident end surface of the light guide plate of the present invention while facing it and a light source disposed portion,
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。 An end of the entrance end face side of the at least one surface of the front and rear faces of the light guide plate, for said emitted from the light source unit, the front of the normal of the light guide plate the light incident from the incident end face to the light guide plate it is characterized in that the angle is refracted surface for refracting in the direction to become smaller is formed.

【0012】この面光源によれば、光源部から出射し、 According to the surface light source, emitted from the light source unit,
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。 Light incident from the incident end face to the light guide plate, an angle relative to the normal of the front surface of the light guide plate by the refractive surface formed on an end portion of the entrance end face side of the at least one surface of the front and rear faces of the light guide plate to be refracted in the smaller direction, incident from the incident end face to the light guide plate light is guided to the light guide plate, in a region near the incident end face of the light guide plate front by a total reflection critical angle less than the angle of incidence it is incident, also able to emit a sufficient amount of light from the region near the incident end face of the light guide plate front, therefore, it is possible to emit substantially uniform intensity light 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。 DETAILED DESCRIPTION OF THE INVENTION The surface light source of this invention, as described above, the incident end surface of the light guide plate, refract light emitted from the light source unit in a direction in which the angle is reduced relative to the normal of the front surface of the light guide plate by providing a refractive surface for incident on the light guide plate Te, in which so as to emit a substantially uniform intensity light 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。 [0014] In the surface light source, refractive surface provided on the entrance end face of the light guide plate is preferably formed of a plurality of prism surface or lens surface arranged in a 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。 [0015] Other surface light source of this invention, the end portion of the entrance end face side of the at least one surface of the front and rear surfaces of the light guide plate, and emitted from the light source unit, is incident from the incident end face to the light guide plate by forming a refractive surface that refracts light in a direction angle is smaller relative to the normal of the front surface of the light guide plate, in which so as to emit a substantially uniform intensity light 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。 [0016] In the surface light source, a refractive surface formed on the end portion of the entrance end face side of the at least one surface of the front and rear faces of the light guide plate to said surface of the refractive surface is formed, the incident preferably toward the end face to the other end direction of the light guide plate has an inclined surface that recessed obliquely toward the interior 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。 Further, none of the surface light source of the present invention, the front side of the front surface of the light guide plate, having a configuration in which the optical means for refracting the light emitted from the front surface of the light guide plate in a predetermined direction is disposed preferably .

【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。 PREFERRED EMBODIMENTS FIG. 1 and FIG. 2 shows a first embodiment of the present invention, FIG. 1 is a side view of a surface light source, FIG. 2 is an enlarged side view of the entrance end face side of the light guide plate of the surface light source 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。 The surface light source of this embodiment, as shown in FIGS. 1 and 2, and a surface 10c after the optical light is incident to the incident end face 10a to be incident to the front surface 10b and facing the front and emits a light guide plate 10 consists of a light source unit 20. which is arranged to face the incident end surface 10a of the light guide plate 10.

【0020】前記導光板10は、出射面である前面10 [0020] The light guide plate 10, the front 10 is emitting surface
bが平坦面に形成され、後面10cが前記入射端面10 b is formed on the flat surface, the rear surface 10c is the incident end face 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 a has become a wedge-shaped transparent plate which is formed on the inclined surface inclined so as to approach the front 10b (e.g. acrylic resin) toward the other end from the surface 10 after the light guide plate 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。 For c, over its entire surface, the reflective layer 11 made of vapor-deposited or plated film of a high reflectance metal such as aluminum is provided.

【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 Further, the incident end face 10a of the light guide plate 10, the front face 1 of the light guide plate 10 the light emitted from the light source unit 20
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。 Refractive surface 12 for entering the light guide plate 10 by refracting in the direction in which the angle is reduced is provided with respect to the normal line of the 0b.

【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。 [0022] The refractive surface 12, for example, from a plurality of prism surfaces 12a arranged in the height direction of the incident end face 10a, the plurality of prism surfaces 12a, the length direction of the incident end face 10a (guide It is formed in the 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 [0023] Incidentally, the light guide plate 10 shown in FIGS. 1 and 2
は、その入射端面10aを前記複数のプリズム面12a , The plurality of prism surfaces 12a of the entrance end face 10a
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、 But is obtained by forming a refractive surface 12 composed of the light guide plate 10, the incident end face formed into a flat surface, the incident end surface may be provided with the end surface layer in which the refractive surface 12 is formed, in that case, the end surface layer, apart from forming the light guide plate be attached to the incident end face of the light guide plate, fitting the incident end surface side of the light guide plate in the molding die of the refractive surface 12,
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。 As in the mold by injecting a photocurable resin by light irradiation from the light guide plate side it may be formed by curing. 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。 Meanwhile, the light source unit 20 is, for example, a cold cathode tube 21 of the full-length over the length of the incidence end face 10a of the light guide plate 10, toward the light emitted from the cold cathode tube 21 to the entrance end face 10a of the light guide plate 10 It consists reflector 22 for reflecting Te.

【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 [0024] The surface light source is emitted from the light source unit 20, light incident from the incident end surface 10a to the light guide plate 10, as indicated by arrows in FIGS. 1 and 2, a light guide plate front 10b interface between the total reflection at the interface between the outside air, while guided in the longitudinal direction of the light guide plate 10 by repeated reflection at the reflective film 11 provided on the light guide plate rear surface 10c, the light guide plate and the front face 10b and the outside air the total reflection critical angle is smaller than (nearly vertical) incident light guide plate the light incident at angle front 10b against
から出射する。 It is 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 [0025] In this case, the surface light source of this embodiment, the incident end face 10a of the light guide plate 10, the refractive surface 1 comprising a plurality of prism surfaces 12a arranged in the height direction of the entrance end face 10a
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。 Since is provided with a 2, it said emitted from the light source unit 20, light incident from the incident end surface 10a to the light guide plate 10, the front face 10b of the light guide plate 10 by the refractive surface 12 provided on the entrance end face 10a It is refracted in a direction in which the angle is smaller incident on the light guide plate 10 with respect to the normal line.

【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 [0026] Therefore, according to the surface light source, the light guide plate is incident from the incident end surface 10a to the light guide plate 10 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、 The light guided through the 0, also is incident at the total reflection critical angle smaller than the incident angle to the area near the entrance end face of the light guide plate front 10b,
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 Also it can be emitted a sufficient amount of light from the region near the incident end face of the light guide plate front 10b, therefore, the light guide plate 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。 It is possible to emit substantially uniform intensity light from the entire front surface of.

【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。 [0027] Thus, the surface light source for emitting a substantially uniform intensity light from the entire front surface of the light guide plate 10, for example, by using the surface light source as a light source for a liquid crystal display device, the overall screen brightness it is possible to obtain a liquid crystal display device having uniform good display quality.

【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。 [0028] Figure 3 is a side view of a liquid crystal display device comprising a surface light source of the above embodiment, the liquid crystal display device, the rear side of the liquid crystal display device 30, a surface light source of the above embodiment, the light guide plate 10 front 10b of those of the backlight type which is disposed to face the rear surface of the liquid crystal display device 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。 [0029] Incidentally, the liquid crystal display device 30, TN (twisted nematic) type, STN (super twisted nematic) type, one of the liquid crystal display device of a homogeneous orientation type obtained by homogeneously the liquid crystal molecules in one direction or ferroelectric, a sexual or anti-ferroelectric liquid crystal display device, the specific structure is not shown, the liquid crystal cell 31, respectively transparent electrodes on the inner surface of the pair of transparent substrates before and after the opposite sides of the liquid crystal layer is provided, the liquid crystal It has a pair of polarizing plates 32, 33 arranged on the front surface and the rear surface of the cell 31.

【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。 [0030] When the liquid crystal display device, in an environment of sufficient brightness performs reflective display utilizing external light is a light of the environment, no external light sufficient brightness is obtained, from the surface light source the illumination light is emitted and performs transmissive display utilizing the illumination light, when the reflective display utilizing external light, incident from the front side is the viewing side of the display, transmitted through the liquid crystal display device 30 light is reflected by the surface reflection film 11 provided on the rear surface 10c of the light guide plate 10 of the light source as indicated by the dashed arrows in the figure, the front and the reflected light is transmitted through the liquid crystal display device 30 It is emitted.

【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。 Further, when the transmission display that utilizes the illumination light, illumination light emitted from the surface light source is incident from the rear surface to the liquid crystal display device 30 as indicated by solid line arrows in the figure, the 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 [0032] The surface light source of the above embodiments, the light guide plate 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 Although that the reflective film 11 on the rear surface 10c of providing the reflective film 11 of the rear surface 10c of the light guide plate 10 may be omitted, in which case also, emitted from the light source unit 20, the light guide plate 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 0 to the light incident from the incident end surface 10a, and the total reflection at the interface between the front 10b and the outside air light guide plate, light guide plate rear surface 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 The light guide plate 10 by repeating the total reflection at the interface between the outside air
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。 While the guidance of the longitudinal direction, can be emitted from the light guide plate front 10b.

【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。 [0033] omitted from the surface light source reflection film 11 of the rear surface 10c of the thus the light guide plate 10 is not limited to a backlight type liquid crystal display device which performs reflective display and transmissive display and shown in FIG. 3, always a surface light source a backlight type liquid crystal display device which performs transmissive display utilizing illumination light from are also can be used in the 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。 [0034] Figure 4 is a side view of a front light type liquid crystal display device provided with a omitted surface light source reflection film 11 of the rear surface 10c of the light guide plate 10, the liquid crystal display device, the front side of the liquid crystal display device 30 in the surface light source of the above examples to place the front surface 10b of the light guide plate 10 is opposed to the front surface of the liquid crystal display device 30, configuration and placing the reflecting plate 34 to the rear side of the liquid crystal display device 30 going on. 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。 Incidentally, the liquid crystal display device 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。 [0035] When the liquid crystal display device, in an environment of sufficient brightness performs reflective display utilizing external light is a light of the environment, no external light sufficient brightness is obtained, from the surface light source the illumination light is emitted and performs reflective display utilizing the illumination light, when the reflective display utilizing external light, incident from the front side is the viewing side of the display, a light guide plate 10 of the surface light source the light transmitted through the liquid crystal display element 30 is reflected by the reflecting plate 34 as indicated by dashed arrows in the figure, the reflected light is transmitted through the light guide plate 10 of the surface light source and the liquid crystal display device 30 Te is emitted 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 Further, when the reflection display utilizing the illumination light, incident from the front surface to the liquid crystal display device 30 as illumination light emitted from the surface light source is indicated by the solid line of arrows in the figure, the light transmitted through the liquid crystal display element 30 is reflected by the reflection plate 34, the reflected light the liquid crystal display device 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。 0 and passes through the light guide plate 10 of the surface light source for emitting the front.

【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 [0037] Figure 5 is a side view of a surface light source of a second embodiment of the present invention, a surface light source of this embodiment, the surface light source of the first embodiment described above, output from the light source unit 20 polarizer 23 for causing incident on the light guide plate 10 Shako as linearly polarized light
を付加したものである。 It is obtained by adding a. 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。 Incidentally, the polarizing plate 23 is fitted into the 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 to be incident light emitted from the light source unit 20 to the light guide plate 10 as linearly polarized light, from the entire front surface of the light guide plate 10, substantially uniform strength, yet is capable of emitting linearly polarized light of the polarized component along the transmission axis (not shown) of the polarizer 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 is to be used for all the liquid crystal display device shown in FIG. 3 and FIG. 4, the surface light source in the backlight-type liquid crystal display device shown in FIG. 3 If used, the orientation of the transmission axis of the polarizing plate 23, from the front surface of the light guide plate 10, the linearly polarized light of the polarized component along the transmission axis of the side polarizing plate 33 after the liquid crystal display device 30 so as to emit settings can be.

【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 The backlit liquid crystal display device provided with a surface light source of this embodiment, the liquid crystal display element 30 from the surface light source
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。 Rear linearly polarized light of the polarized component along the transmission axis of the polarizing plate 33 is emitted, in order to enter the liquid crystal cell 31 the light is transmitted through the rear polarization plate 33, the polarization degree in the liquid crystal cell 31 of the is incident high linearly polarized light, it is possible to obtain a more high-contrast display.

【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。 [0041] The back light type liquid crystal display device provided with a surface light source of this embodiment, the omitted side polarizing plate 33 after the liquid crystal display device 30, as the liquid crystal and linearly polarized light emitted from the surface light source it may be configured to be incident on the cell 31.

【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。 Further, when using the surface light source of this embodiment in a front light type liquid crystal display device shown in FIG. 4, the orientation of the transmission axis of the polarizing plate 23, from the front surface of the light guide plate 10, a liquid crystal display the linearly polarized light of the polarized component along the transmission axis of the front polarizing plate 32 of the element 30 may be set so as to emit.

【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 The front light type liquid crystal display device provided with a surface light source of this embodiment, the liquid crystal display device 3 from the surface light source
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。 0 linearly polarized light of the polarized component along the transmission axis of the front polarizing plate 32 is emitted in order to enter the liquid crystal cell 31 the light is transmitted through the front polarization plate 33, the polarization degree in the liquid crystal cell 31 is incident high linearly polarized light, it is possible to obtain a more high-contrast display.

【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 [0044] FIGS. 6-8 are side views of the third to fifth surface light source of an embodiment of the invention, respectively, a surface light source of these embodiments, the surface light source of the first embodiment described above in front of the front face 10b of the light guide plate 10, the front face 10 of the light guide plate 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。 The light emitted from the b is obtained by placing the optical means for refracting a predetermined direction.

【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 [0045] That is, the front surface 10 of the third embodiment surface light source, a first embodiment the surface light source the light guide plate 10 of the shown in FIG. 6
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。 In front of b, it is obtained by placing the optical means 24a consisting of the condensing plate 26 and having a directivity in the front direction provided on the front side of the diffusion plate 25 and the diffusion plate 25.

【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。 [0046] Incidentally, the diffusion plate 25 is, for example, made of a transparent resin film diffusing particles are mixed, the collector panel 26 has an elongated isosceles triangular prism along the width direction of the light guide plate 10 to the front parts is made of a prism sheet which are parallel to each other side by side tightly.

【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。 [0047] According to the surface light source of this embodiment, the light emitted from the front surface 10b of the light guide plate 10 causes diffused by the diffusion plate 25, the front direction (the light guide plate 10 by the collector panel 26 that diffuses light it is possible to emit by focusing in the normal direction in the vicinity of) the front 10b, the intensity distribution is more uniform, yet it is possible to emit light having a directivity in the front direction.

【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。 [0048] The surface light source of the fourth embodiment shown in FIG. 7, the front side of the first embodiment the front 10b of the light guide plate 10 of the surface light source, light refracting plate 27 having a directivity in the front direction it is obtained by arranging the optical means 24b consisting of.

【0049】なお、前記光屈折板27は、前記導光板1 [0049] Incidentally, the light refracting plate 27, the light guide plate 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 rear face facing the front face 10b of 0, the prism portions of the elongated isosceles triangle shape along the width direction of the light guide plate 10 is made of a prism sheet which is formed in parallel to each other side by side closely.

【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、 [0050] According to the surface light source of this example, it is possible to emit the light emitted from the front surface 10b of the light guide plate 10 by refracting the front direction by the light refracting plate 27,
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。 Intensity distribution is uniform. Moreover, it is possible to emit light having a directivity in the front direction.

【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。 [0051] The surface light source of the fifth embodiment shown in FIG. 8, the front side of the front surface 10b of the first embodiment the light guide plate 10 of the surface light source, the directivity in the direction oblique to the front direction it is obtained by arranging the optical means 24c made of a light refracting plate 28 having.

【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。 [0052] Incidentally, the light refracting plate 28, the front, the elongated scalene triangular prism portion along the widthwise direction of the light guide plate 10 is made of serrated prism sheet formed in parallel to each other side by side closely .

【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。 [0053] According to the surface light source of this example, it is possible to emit the light emitted from the front surface 10b of the light guide plate 10 by refracting in an oblique direction with respect to the front direction by the light refracting plate 28, the intensity distribution is uniform, yet it is possible to emit light having a directivity in an oblique direction.

【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。 [0054] Incidentally, the surface light source third to fifth examples are intended to the reflective film 11 is provided on the surface 10c after the light guide plate 10, reflection film 11 of the rear surface 10c of the light guide plate 10 is omitted it 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 [0055] Further, the surface light source of the first to fifth embodiment, the incident end face 10a of the light guide plate 10, the incident end face 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。 But is provided with a refracting surface 13 comprising a plurality of horizontal prism surface 12a arranged in the height direction of a, the refractive surface is provided on the incident end face 10a of the light guide plate 10, light guide plate the light emitted from the light source unit 20 10 as long as the angle relative to the normal of the front surface 10b is incident on the light guide plate 10 by refracting the direction becomes small, for example, be a refracting surface composed of a plurality of horizontally elongated lens surfaces arranged in a height direction of the entrance end face 10a or it may be a refracting surface composed of a plurality of pyramid-shaped prism surfaces or spherical lens surfaces arranged in the height direction and the length direction of the incident end face 10a.

【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。 [0056] FIGS. 9 and FIG. 10 shows a sixth embodiment of the present invention, FIG. 9 is a side view of a surface light source, 10 is a enlarged side view of the entrance end face side of the light guide plate of the surface light source .

【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。 [0057] The surface light source of this embodiment, the incident end face 10a of the light guide plate 10 is substantially vertical surface, respectively on the end of the entrance end face 10a side of the front 10b and rear surface 10c of the light guide plate 10 from the light source unit 20 the emitted, which light incident from the incident end face 10a to the light guide plate 10 to form the refractive surface 13, 14 to be refracted in a direction in which the angle relative to the normal of the front surface 10b decreases of the light guide plate 10, the other 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 [0058] In the surface light source in this embodiment, the refractive surfaces 13 formed on the end portion of the entrance end face 10a side of the front 10b of the light guide plate 10 with respect to the light guide plate front 10b, the entrance end face 10a of the light guide plate 10 toward the other direction the light guide plate 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、 0 has become the inclined surface recessed obliquely inward of,
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。 Further, the refractive surface 14 formed on the end portion of the entrance end face 10a side of the rear surface 10c of the light guide plate 10 with respect to the light guide plate rear surface 10c, the light guide plate toward the other direction of the light guide plate 10 from the incident end face 10a It consists inclined surface recessed obliquely toward the interior of 10.

【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 [0059] The surface light source of this embodiment, the light guide plate 10 respectively to the ends of the incident end surface 10a side of the front 10b and rear 10c, the light guide plate 10 toward the other end direction of the light guide plate 10 from the incident end face 10a because it is made by forming the refractive surfaces 13 and 14 consisting of inclined surface recessed obliquely inwardly, emitted from the light source unit 20, the incident end face 10a into the light guide plate 10
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 Of the light incident from the light toward the end portion of the entrance end face 10a side of the front 10b and rear surface 10c of the light guide plate 10 is, as shown in FIGS. 9 and 10 arrows, and the refracting surfaces 13 and 14 is totally reflected at the interface between the outside air, the light guide plate 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。 Angle with respect to the normal of the front surface 10b of 0 is refracted in a direction to become smaller.

【0060】そのため、この実施例の面光源によれば、 [0060] Therefore, according to the surface light source of this embodiment,
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。 Wherein the light guide plate 10 is incident from the incident end surface 10a of the light guided to the light guide plate 10, also in the area near the entrance end face of the light guide plate front 10b is incident at a small angle of incidence than the total reflection critical angle, guide also able to emit a sufficient amount of light from the region near the entrance end face of the optical plate front 10b, therefore, it is possible to emit substantially uniform intensity light from the entire front surface of the light guide plate. 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。 It is possible to emit substantially uniform intensity light 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、 [0061] In this embodiment, the end portion of the entrance end face 10a side of the front 10b and rear surface 10c of the light guide plate 10,
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 While forming the refractive surface 13, 14 made of inclined surface recessed obliquely toward the inside of the light guide plate 10 toward the other end direction of the light guide plate 10 from the incident end surface 10a, the light guide plate 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。 Refracting surfaces forming the end portion of the entrance end face 10a side of the front 10b and rear surface 10c is emitted from the light source unit 20, the light incident from the incident end face 10a to the light guide plate 10 of the front surface 10b of the light guide plate 10 if a surface that refracts in the direction in which the angle with respect to the normal line becomes smaller, or as a curved refractive 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 [0062] Further, in this embodiment, each end portion of the entrance end face 10a side of the front 10b and rear surface 10c of the light guide plate 10 to form the refractive surfaces 13 and 14, the light source unit 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。 Emitted from the refractive surface to refract in a direction in which the angle is reduced relative to the normal of the front surface 10b of the light guide plate 10 the incident end face 10a the light guide plate 10 light incident from the front 10b and a rear surface of the light guide plate 10 either it may be formed only on one side of the 10c.

【0063】さらに、この実施例の面光源は、導光板1 [0063] Further, the surface light source of this embodiment, the light guide plate 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。 But is provided with a reflection film 11 on the rear surface 10c of 0, reflection film 11 of 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 [0064] The surface light source of this embodiment, FIGS. 6 to 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 Like the surface light source device of the third to fifth embodiments shown in the front 1 of the light guide plate 10 on the front side of the front surface 10b of the light guide plate 10
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、 Optical means 24a for the light emitted from 0b refracted in a predetermined direction, 24b, may be configured to place the 24c,
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。 In this way, the intensity distribution is uniform. Moreover, it is possible to emit light having a 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。 [Effect of the Invention The surface light source of this invention, the incident end surface of the light guide plate, the light emitted from the light source unit to the light guide plate is refracted in the direction in which the angle to the normal of the front surface decreases the light guide plate since is provided with a refracting surface for incident, it is possible to emit substantially uniform intensity light 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。 [0066] In the surface light source, refractive surface provided on the entrance end face of the light guide plate is preferably formed of a plurality of prism surface or lens surface arranged in a height direction of the incident end face, such a refractive by providing the surface, it can be incident light emitted from the light source unit to the light guide plate is refracted in the direction in which the angle to the normal of the front surface decreases 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。 [0067] Another surface light source of this invention, the end portion of the entrance end face side of the at least one surface of the front surface and the rear surface of the light guide plate, and emitted from the light source unit, the incident on the light guide plate since it is obtained by forming a refractive surface that refracts light incident from the end face in the direction in which the angle is reduced to the normal of the front surface of the light guide plate, emitting substantially uniform intensity light 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。 [0068] In the surface light source, a refractive surface formed on the end portion of the entrance end face side of the at least one surface of the front and rear faces of the light guide plate to said surface of the refractive surface is formed, the incident It is preferably formed of a sloped surface which recessed obliquely toward the interior of the light guide plate from the end face toward the other end direction of the light guide plate, by forming such a refractive surface, emitted from the light source unit and it can be refracted in a direction in which the angle decreases the light incident from the incident end face to the light guide plate with respect to the normal of 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。 [0069] Further, none of the surface light source of the present invention, the front side of the front surface of the light guide plate, preferably having a structure in which the optical means is arranged to refract the light emitted from the front surface of the light guide plate in a predetermined direction by doing so, the intensity distribution is uniform. Moreover, it is possible to emit light having a directivity in a predetermined direction.

【図面の簡単な説明】 BRIEF DESCRIPTION OF THE DRAWINGS

【図1】この発明の第1の実施例を示す面光源の側面図。 Figure 1 is a side view of a surface light source of 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。 Figure 2 is an enlarged side view of the entrance end face side of the light guide plate of the surface light source of the first embodiment.

【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。 Figure 3 is a side view of a backlight type liquid crystal display device having a surface light source of 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。 Figure 4 is a side view of a front light type liquid crystal display device having a first embodiment the surface light source is omitted reflective film from the surface light source of the rear surface of the light guide plate.

【図5】この発明の第2の実施例を示す面光源の側面図。 Figure 5 is a side view of a surface light source of 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。 Figure 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。 Figure 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。 Figure 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。 Figure 9 is a side view of a surface light source of 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。 [10] Sixth enlarged side view of the entrance end face side of the light guide plate of the surface light source of the embodiment of.

【図11】従来の面光源の側面図 Figure 11 is a side view of a conventional surface light source

【符号の説明】 DESCRIPTION OF SYMBOLS

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 10 ... light guide plate 10a ... incident end surface 10b ... Front 10c ... rear 11 ... reflecting film 12 ... refractive surface 12a ... prism surfaces 13, 14 ... refracting surface 20 ... light source unit 24a, 24b, 24c ... optical means 25 ... diffusion plate 26 ... The light collecting plate 27, 28 ... light refraction plate

───────────────────────────────────────────────────── 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 ────────────────────────────────────────────────── ─── of the front page continued (51) Int.Cl 7 identification mark FI theme Court Bu (reference) G02F 1/13357 G02F 1/13357 // F21Y 103 :. 00 F21Y 103: 00

Claims (5)

    【特許請求の範囲】 [The claims]
  1. 【請求項1】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面光源。 1. A light light is incident to the incident end face to be incident to emit front and a light guide plate comprising a rear surface of the front facing, a light source unit disposed to face the incident end surface of the light guide plate consists of a, the incident end face of the light guide plate, the refractive surface for incident on the light guide plate the light emitted from the light source unit angle is refracted in a direction decreases relative to the normal of the front surface of the light guide plate provided a surface light source, characterized by being.
  2. 【請求項2】導光板の入射端面に設けられた屈折面は、 2. A refractive surface provided on the incident end face of the light guide plate,
    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。 The surface light source of claim 1, characterized in that it comprises a plurality of prism surface or lens surface arranged in a height direction of the incident end face.
  3. 【請求項3】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面光源。 3. An optical light is incident to the incident end face to be incident to emit front and a light guide plate comprising a rear surface of the front facing, a light source unit disposed to face the incident end surface of the light guide plate consists of a, the said end portion of the entrance end face side of the at least one surface of the front and rear surfaces of the light guide plate, and emitted from the light source unit, the front face of the light guide plate the light incident from the incident end face to the light guide plate a surface light source, wherein a refracting surface the angle of with respect to the normal to refract in the direction of smaller is formed.
  4. 【請求項4】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 the end portion of the entrance end face side of the at least one surface of the front and rear faces of the light guide plate to said surface of the refractive surface is formed, the light guide plate from the entrance end face the surface light source of claim 3, characterized in that it consists of inclined surface recessed obliquely toward the interior of the light guide plate toward the other end direction.
  5. 【請求項5】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。 The front side front surface of the 5. A light guide plate, a surface according to claim 1 or 3, characterized in that optical means for refracting the light emitted from the front surface of the light guide plate in a predetermined direction is disposed light source.
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US7310122B2 (en) 2003-03-31 2007-12-18 Sharp Kabushiki Kaisha Liquid crystal display apparatus
US7046317B2 (en) 2003-03-31 2006-05-16 Sharp Kabushiki Kaisha Liquid crystal display apparatus
US9177523B2 (en) 2005-02-23 2015-11-03 Pixtronix, Inc. Circuits for controlling display apparatus
US9087486B2 (en) 2005-02-23 2015-07-21 Pixtronix, Inc. Circuits for controlling display apparatus
US9274333B2 (en) 2005-02-23 2016-03-01 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
US9135868B2 (en) 2005-02-23 2015-09-15 Pixtronix, Inc. Direct-view MEMS display devices and methods for generating images thereon
US9229222B2 (en) 2005-02-23 2016-01-05 Pixtronix, Inc. Alignment methods in fluid-filled MEMS displays
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
US9500853B2 (en) 2005-02-23 2016-11-22 Snaptrack, Inc. MEMS-based display apparatus
US9128277B2 (en) 2006-02-23 2015-09-08 Pixtronix, Inc. Mechanical light modulators with stressed beams
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