JPH0894846A - Light source device - Google Patents

Light source device

Info

Publication number
JPH0894846A
JPH0894846A JP6231282A JP23128294A JPH0894846A JP H0894846 A JPH0894846 A JP H0894846A JP 6231282 A JP6231282 A JP 6231282A JP 23128294 A JP23128294 A JP 23128294A JP H0894846 A JPH0894846 A JP H0894846A
Authority
JP
Japan
Prior art keywords
light
guide plate
incident
main surface
light guide
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
Application number
JP6231282A
Other languages
Japanese (ja)
Inventor
Hiroyoshi Fujishiro
浩佳 藤代
Atsunori Oyama
敦則 大山
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Toshiba Development and Engineering Corp
Original Assignee
Toshiba Corp
Toshiba Electronic Engineering Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, Toshiba Electronic Engineering Co Ltd filed Critical Toshiba Corp
Priority to JP6231282A priority Critical patent/JPH0894846A/en
Publication of JPH0894846A publication Critical patent/JPH0894846A/en
Pending legal-status Critical Current

Links

Landscapes

  • Light Guides In General And Applications Therefor (AREA)
  • Liquid Crystal (AREA)

Abstract

PURPOSE: To provide a light source device capable of improving the utilization efficiency of light without thickening a light transmission plate. CONSTITUTION: Irradiating light from a fluorescent lamp 3 is reflected by a reflector 4 and made incident from the light incident main surface 1c of the light transmission plate 1, then the incident light is guided to the entire plate 1, scattered and projected by a scattering body 5, reflected by a reflector 6 toward a front surface, and irradiates the back surface of a liquid crystal panel 7 by setting the main surface 1a of the plate 1 as a surface light source apparently. Since a thick part 1d has the angle of 3 deg. to the main surfaces 1a and 1b, an incident angle in second and succeeding total reflection on the inner surface of the plate 1 becomes a critical angle 42 deg. decided by the refractive index of the plate 1 even when the light radiated from a lamp device 2 is made incident on the plate 1 at the maximum incident angle. Even when the area of the plate 1 opposed to the lamp device 2 becomes large, the light from the lamp device 2 is efficiently taken in and luminance on the main surface 1a of the plate 1 is improved.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、導光板の側面に配設さ
れた光源の光を導光板の主面に見掛上の平面光源を形成
する光源装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device for forming light of a light source arranged on a side surface of a light guide plate into an apparent flat light source on a main surface of the light guide plate.

【0002】[0002]

【従来の技術】導光板の主面に見掛上の平面光源を形成
し、面状に均一に照明する光源装置は、近年、航空機、
自動車などの運転表示装置、あるいは、オフィスオート
メーション(OA)機器として、携帯用のパーソナルコ
ンピュータ、ワードプロセッサなどに用いられている。
2. Description of the Related Art In recent years, a light source device for forming an apparent flat light source on a main surface of a light guide plate and uniformly illuminating the light source has been proposed in recent years.
It is used in portable personal computers, word processors, etc. as an operation display device for automobiles or as office automation (OA) equipment.

【0003】この光源装置の構成としては、光源を液晶
パネルの背後に直接配置する構成と、液晶パネルの背後
に板状の導光板を液晶パネルとほぼ平行に配置してこの
導光板の側面、すなわち液晶パネルに直交する面から光
源の光を入射させるようにした構成などが知られてい
る。なお、この導光板は、アクリル樹脂やガラスのよう
な透明材料で構成され、周面が光学的平面を呈するよう
に研磨され、周縁から入射した光は内部を全反射を繰り
返しながら進行し、その一部は板の一面方向に散乱させ
る散乱板としての機能をも有している。
The structure of this light source device is such that the light source is arranged directly behind the liquid crystal panel, and a plate-like light guide plate is arranged behind the liquid crystal panel substantially parallel to the liquid crystal panel, and the side surface of the light guide plate is arranged. That is, there is known a configuration in which light from a light source is made incident from a plane orthogonal to the liquid crystal panel. The light guide plate is made of a transparent material such as acrylic resin or glass, and the peripheral surface is polished so as to present an optical flat surface, and the light incident from the peripheral edge proceeds while repeating total internal reflection, Some of them also have a function as a scattering plate that scatters in one direction of the plate.

【0004】そして、室外や室内でも明るい環境で主と
して使用される航空機、自動車の運転表示装置として使
用される液晶パネルの場合には、発光源を液晶パネルの
背後に直接配置する構成が利用され、表示の明るさより
も軽さと薄さを優先させるたとえば携帯用のパーソナル
コンピュータ、ワードプロセッサなどの表示装置として
使用される液晶パネルの場合には、導光板を使用した構
成が利用されている。
In the case of a liquid crystal panel used as an operation display device of an aircraft or an automobile which is mainly used in a bright environment both outdoors and indoors, a structure in which a light source is arranged directly behind the liquid crystal panel is used. In the case of a liquid crystal panel used as a display device such as a portable personal computer or a word processor in which lightness and thinness are prioritized over display brightness, a configuration using a light guide plate is used.

【0005】ところが、技術の進歩により液晶パネルの
大型化が進み、光源を液晶パネルの背後に直接配置する
構成は困難になってきているとともに、携帯用のパーソ
ナルコンピュータ、ワードプロセッサの普及に伴い、薄
型軽量でありながら室外の明るい環境にあっても使用に
耐え得る液晶パネルの画面の明るさが要求されている。
However, as the size of the liquid crystal panel has increased due to technological progress, it has become difficult to dispose the light source directly behind the liquid crystal panel, and with the spread of portable personal computers and word processors, it has become thinner. It is required that the brightness of the liquid crystal panel screen be light enough to be used even in a bright outdoor environment.

【0006】そして、この種の従来の液晶表示装置とし
ては、たとえば図5に示す構成が知られている。
As a conventional liquid crystal display device of this type, for example, the configuration shown in FIG. 5 is known.

【0007】図5に示すように、屈折率1.49のアク
リル樹脂で導光板1は、表面および背面にそれぞれ主面
1a,1bが形成され、側面に光入射主面1cが形成されてい
る。そして、この光入射主面1cに対向して、光源として
のランプ装置2が設けられている。このランプ装置2
は、導光板1の光入射主面1cに沿って設けられた直管状
の蛍光ランプ3と、この蛍光ランプ3を内包し、蛍光ラ
ンプ3からの光を導光板1の光入射主面1c側に反射し、
ポリエチレンフィルムなどの薄いプラスチックフィルム
に銀、アルミニウムなどの反射率の高い金属薄膜を蒸着
した筒状の反射体4を有している。
As shown in FIG. 5, the light guide plate 1 is made of an acrylic resin having a refractive index of 1.49.
1a and 1b are formed, and the light incident main surface 1c is formed on the side surface. A lamp device 2 as a light source is provided so as to face the light incident main surface 1c. This lamp device 2
Is a straight tubular fluorescent lamp 3 provided along the light-incident main surface 1c of the light guide plate 1, and the fluorescent lamp 3 is included therein, and the light from the fluorescent lamp 3 is directed to the light-incident main surface 1c side of the light guide plate 1. Reflected on the
It has a tubular reflector 4 in which a thin metal film having a high reflectance such as silver or aluminum is deposited on a thin plastic film such as a polyethylene film.

【0008】また、導光板1の背面側の主面1bには、光
を散乱させる物質を特定のパターンで塗布しておくかま
たは微小部分の形状を変えた構造の散乱体5が形成され
るとともに、反射板6が主面1bに沿って配設され、さら
に、導光板1の表面側の主面1aの前面側には、液晶パネ
ル7が配設されている。
Further, on the back-side main surface 1b of the light guide plate 1, there is formed a scatterer 5 having a structure in which a substance that scatters light is applied in a specific pattern or the shape of a minute portion is changed. At the same time, the reflection plate 6 is arranged along the main surface 1b, and further, the liquid crystal panel 7 is arranged on the front surface side of the main surface 1a on the front surface side of the light guide plate 1.

【0009】そして、蛍光ランプ3からの照射光を反射
体4で反射して、導光板1の光入射主面1cから入射し、
入射された光は導光板1の全体に光が導光され、散乱体
5で光を散乱して射出し反射板6で前面方向に向けて光
を反射し、導光板1の主面1aを見掛上平面光源として液
晶パネル7を背面から照射している。
The light emitted from the fluorescent lamp 3 is reflected by the reflector 4 and is incident from the light incident main surface 1c of the light guide plate 1,
The incident light is guided to the entire light guide plate 1, scattered by the scatterer 5 and emitted, and reflected by the reflector plate 6 toward the front side, and the main surface 1a of the light guide plate 1 is reflected. The liquid crystal panel 7 is illuminated from the back as an apparently flat light source.

【0010】ここで、図5に示す液晶表示装置は、導光
板1の屈折率n1 =1.5、空気の屈折率n0 =1と仮
定し、ランプ装置2からの入射角θ0 、屈折角θ1 、臨
界角θc とすると、A点に入射する角度θ0 が最大90
°に近いときの屈折角θ1 は、スネルの法則より θ1 =sin-1{sinθ0 (n0 /n1 )}=42° となる。そこで、B点の入射角は、48°となる。この
B点での臨界角は、 θ1 =θc =42° である。
Here, in the liquid crystal display device shown in FIG. 5, assuming that the light guide plate 1 has a refractive index n 1 = 1.5 and the air has a refractive index n 0 = 1, the incident angle θ 0 from the lamp device 2, If the refraction angle is θ 1 and the critical angle is θ c , the incident angle θ 0 at point A is 90 at maximum.
According to Snell's law, the refraction angle θ 1 when close to θ is θ 1 = sin −1 {sin θ 0 (n 0 / n 1 )} = 42 °. Therefore, the incident angle at point B is 48 °. The critical angle at this point B is θ 1 = θ c = 42 °.

【0011】したがって、A点での屈折角は最大でも4
2°、B点での入射角は最小でも48°であり、B点で
の臨界角は42°、入射角は最小で48°であり、B点
で全反射させるには入射角が最低で42°であればよい
ので臨界角θc に対しては6°大きい入射角となり、ラ
ンプ装置2からの光を有効に利用できない。
Therefore, the maximum refraction angle at point A is 4
2 °, the incident angle at point B is at least 48 °, the critical angle at point B is 42 °, the incident angle is at minimum 48 °, and the incident angle is at minimum for total reflection at point B. Since 42 ° is sufficient, the incident angle is 6 ° larger than the critical angle θ c , and the light from the lamp device 2 cannot be effectively used.

【0012】また、導光板1の厚さが1.5〜4mmと
薄くなり、導光板1の薄型化にともない蛍光ランプ3も
細くなってきており、将来はもっと薄型化が図られると
考えられ、効率を向上して平面光源としての輝度を向上
させる必要がある。
Further, the thickness of the light guide plate 1 is as thin as 1.5 to 4 mm, and the fluorescent lamp 3 is becoming thinner as the light guide plate 1 is made thinner, and it is considered that the fluorescent lamp 3 will be made thinner in the future. It is necessary to improve efficiency and brightness as a flat light source.

【0013】一方、蛍光ランプ3と向かい合う導光板1
の面積を広げれば、導光板1の全体の厚みが厚くなる。
On the other hand, the light guide plate 1 facing the fluorescent lamp 3
If the area is increased, the overall thickness of the light guide plate 1 is increased.

【0014】[0014]

【発明が解決しようとする課題】上述のように、導光板
の板厚が薄くなると光源からの光を効率よく使用でき
ず、反対に、導光板の板厚を厚くすると薄型軽量化を図
れない問題を有している。
As described above, if the thickness of the light guide plate is thin, the light from the light source cannot be used efficiently, and conversely, if the thickness of the light guide plate is thick, it is not possible to reduce the thickness and weight. I have a problem.

【0015】本発明は、上記問題点に鑑みなされたもの
で、導光板を厚くすることなく光の利用効率を向上でき
る光源装置を提供することを目的とする。
The present invention has been made in view of the above problems, and an object of the present invention is to provide a light source device capable of improving light utilization efficiency without increasing the thickness of the light guide plate.

【0016】[0016]

【課題を解決するための手段】本発明の光源装置は、表
面および背面にそれぞれ一方および他方の主面が形成さ
れ側面に光入射主面が形成された平板状の導光板と、こ
の導光板の光入射主面に対向して配置された光源とを具
備し、前記導光板は、前記光入射主面から入射される光
源からの光が前記一方の主面で反射されて前記他方の主
面に到達する場合、この反射された光の前記一方の主面
への入射角がこの導光板の屈折率により規定される臨界
角以下であるものである。
DISCLOSURE OF THE INVENTION A light source device of the present invention is a flat light guide plate having one and the other main surfaces formed on the front surface and the back surface, and a light incident main surface formed on the side surface, and this light guide plate. Light source arranged to face the light incident main surface of the light guide plate, the light guide plate is configured such that light from the light source incident from the light incident main surface is reflected on the one main surface and the other main surface. When reaching the surface, the incident angle of the reflected light on the one main surface is equal to or less than the critical angle defined by the refractive index of the light guide plate.

【0017】[0017]

【作用】本発明は、導光板は、光入射主面から入射され
る光源からの光が一方の主面で反射されて他方の主面に
到達する場合、この反射された光の一方の主面への入射
角がこの導光板の屈折率により規定される臨界角以下で
あるため、入射された光を効率よく一方の主面から他方
の主面に反射できるため、光源からの光量が同じなら
ば、導光板の明るさをより明るくできる。
According to the present invention, when the light from the light source incident from the light incident main surface is reflected by one main surface and reaches the other main surface, the light guide plate has one main surface of the reflected light. Since the angle of incidence on the surface is less than or equal to the critical angle defined by the refractive index of this light guide plate, the incident light can be efficiently reflected from one main surface to the other main surface, so the amount of light from the light source is the same. Then, the brightness of the light guide plate can be made brighter.

【0018】[0018]

【実施例】以下、本発明の光源装置の一実施例の液晶表
示装置を図面を参照して説明する。なお、図5に示す従
来例に対応する部分には、同一符号を付して説明する。
DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device as an embodiment of the light source device of the present invention will be described below with reference to the drawings. The parts corresponding to those of the conventional example shown in FIG.

【0019】図1に示すように、屈折率1.49のアク
リル樹脂で導光板1は、表面および背面にそれぞれ主面
1a,1bが形成され、これら主面1a,1bと直交する側面に
光入射主面1cが形成され、それぞれの主面1a,1bの光入
射主面1c側には、光入射主面1cに沿ってこの光入射主面
1c側に向けてそれぞれの主面1a,1bから全反射面を中心
線として3°の角度で拡開し、主面1a,1bとは非平行の
肉厚部1dが形成されている。
As shown in FIG. 1, the light guide plate 1 is made of an acrylic resin having a refractive index of 1.49.
1a and 1b are formed, a light incident main surface 1c is formed on a side surface orthogonal to the main surfaces 1a and 1b, and a light incident main surface 1c is formed on the light incident main surface 1c side of each of the main surfaces 1a and 1b. Along this light incident main surface
Thickened portions 1d are formed toward the 1c side by expanding from the respective main surfaces 1a and 1b at an angle of 3 ° with the total reflection surface as a center line and not parallel to the main surfaces 1a and 1b.

【0020】そして、この光入射主面1cに対向して、光
源としてのランプ装置2が設けられている。このランプ
装置2は、導光板1の光入射主面1cに沿って設けられた
直管状の蛍光ランプ3と、この蛍光ランプ3を内包し、
蛍光ランプ3からの光を導光板1の光入射主面1c側に反
射し、ポリエチレンフィルムなどの薄いプラスチックフ
ィルムに銀、アルミニウムなどの反射率の高い金属薄膜
を蒸着した筒状の反射体4を有している。
A lamp device 2 as a light source is provided so as to face the light incident main surface 1c. The lamp device 2 includes a straight tubular fluorescent lamp 3 provided along the light incident main surface 1c of the light guide plate 1, and the fluorescent lamp 3 included therein.
A cylindrical reflector 4 that reflects the light from the fluorescent lamp 3 to the light incident main surface 1c side of the light guide plate 1 and deposits a thin metal film having a high reflectance such as silver or aluminum on a thin plastic film such as a polyethylene film is formed. Have

【0021】また、導光板1の背面側の主面1bには、光
を散乱させる物質を特定のパターンで塗布しておくかま
たは微小部分の形状を変えた構造の散乱体5が形成され
るとともに、反射板6が主面1bに沿って配設され、さら
に、導光板1の表面側の主面1aの前面側には、液晶パネ
ル7が配設されている。
Further, on the main surface 1b on the back side of the light guide plate 1, a scatterer 5 having a structure in which a substance that scatters light is applied in a specific pattern or the shape of a minute portion is changed is formed. At the same time, the reflection plate 6 is arranged along the main surface 1b, and further, the liquid crystal panel 7 is arranged on the front surface side of the main surface 1a on the front surface side of the light guide plate 1.

【0022】そして、蛍光ランプ3からの照射光を反射
体4で反射して、導光板1の光入射主面1cから入射し、
入射された光は導光板1の全体に光が導光され、散乱体
5で光を散乱して射出し反射板6で前面方向に向けて光
を反射し、導光板1の主面1aを見掛上平面光源として液
晶パネル7を背面から照射している。
The light emitted from the fluorescent lamp 3 is reflected by the reflector 4 and is incident from the light incident main surface 1c of the light guide plate 1,
The incident light is guided to the entire light guide plate 1, scattered by the scatterer 5 and emitted, and reflected by the reflector plate 6 toward the front side, and the main surface 1a of the light guide plate 1 is reflected. The liquid crystal panel 7 is illuminated from the back as an apparently flat light source.

【0023】また、導光板1の屈折率n1 =1.5、空
気の屈折率n0 =1と仮定し、ランプ装置2からの入射
角θ0 、屈折角θ1 、臨界角θc とすると、導光板1の
入射する角度θ0 が最大90°に近いときの屈折角θ1
は、スネルの法則より θ1 =sin-1{sinθ0 (n0 /n1 )}=42° となる。また、導光板1の主面1aの入射角は48°とな
る。
Further, assuming that the refractive index of the light guide plate 1 is n 1 = 1.5 and the refractive index of air is n 0 = 1, the incident angle θ 0 from the lamp device 2, the refraction angle θ 1 , and the critical angle θ c are given. Then, when the incident angle θ 0 of the light guide plate 1 is close to 90 ° at the maximum, the refraction angle θ 1
According to Snell's law, θ 1 = sin −1 {sin θ 0 (n 0 / n 1 )} = 42 °. Further, the incident angle of the main surface 1a of the light guide plate 1 is 48 °.

【0024】さらに、肉厚部1dは主面1a,1bに対して3
°の角度を有しているため、ランプ装置2から照射され
た光が最大入射角で導光板1に入射しても、2回目以降
の導光板1の内面での全反射における入射角が導光板1
の屈折率によって決まる臨界角42°になるため、ラン
プ装置2に対向する導光板1の面積が大きくなっても、
ランプ装置2からの光を効率よく取り入れることがで
き、導光板1の主面1aにおける輝度を向上できる。
Further, the thick portion 1d is 3 with respect to the main surfaces 1a and 1b.
Since the light emitted from the lamp device 2 is incident on the light guide plate 1 at the maximum incident angle, the incident angle in total internal reflection of the inner surface of the light guide plate 1 after the second time is guided because of the angle of °. Light board 1
Since the critical angle is 42 ° which is determined by the refractive index of, even if the area of the light guide plate 1 facing the lamp device 2 becomes large,
Light from the lamp device 2 can be efficiently taken in, and the brightness on the main surface 1a of the light guide plate 1 can be improved.

【0025】次に、他の実施例を図2を参照して説明す
る。
Next, another embodiment will be described with reference to FIG.

【0026】図2に示す実施例は、図1に示す肉厚部1d
に代えて、光入射主面1cの長手方向に沿った中心線を中
心とし、中心線の主面1a,1bに対する垂直面に対してそ
れぞれ6°の角度を持たせたV字型のV溝1eを形成した
ものである。
In the embodiment shown in FIG. 2, the thick portion 1d shown in FIG.
Instead of V, a V-shaped V-shaped groove centered on the center line along the longitudinal direction of the light-incident main surface 1c and having an angle of 6 ° with respect to the plane perpendicular to the main surfaces 1a and 1b of the center line. Formed 1e.

【0027】そして、ランプ装置2から照射された光が
6°の角度を持ったV溝1eに入射されるため、2回目以
降の導光板1の内面での全反射における入射角が導光板
1の臨界角42°になるため、ランプ装置2を導光板1
に近づけることができるとともに、ランプ装置2からの
光を効率よく取り入れることができ、導光板1の主面1a
における輝度を向上できる。
Since the light emitted from the lamp device 2 is incident on the V groove 1e having an angle of 6 °, the incident angle in the total reflection on the inner surface of the light guide plate 1 after the second time is the light guide plate 1. Since the critical angle is 42 °, the lamp device 2 is attached to the light guide plate 1.
The main surface 1a of the light guide plate 1 can be brought into contact with the main surface 1a of the light guide plate 1 efficiently.
The brightness in can be improved.

【0028】また、他の実施例を図3を参照して説明す
る。
Another embodiment will be described with reference to FIG.

【0029】この図3に示す実施例は、図1に示す肉厚
部1dに代えて、導光板1の光入射主面1cを下面に向けて
6°の角度で切断して傾斜面1fを形成したものである。
In the embodiment shown in FIG. 3, instead of the thick portion 1d shown in FIG. 1, the light incident main surface 1c of the light guide plate 1 is cut toward the lower surface at an angle of 6 ° to form an inclined surface 1f. It was formed.

【0030】そして、ランプ装置2から照射された光が
6°の角度の傾斜面1fに入射されるため、2回目以降の
導光板1の内面での全反射における入射角が導光板1の
臨界角42°になるため、ランプ装置2に向かい合う導
光板1の面積が大きくなりランプ装置2からの光を効率
よく取り入れることができ、導光板1の主面1aにおける
輝度を向上できる。
Since the light emitted from the lamp device 2 is incident on the inclined surface 1f having an angle of 6 °, the incident angle in the total reflection on the inner surface of the light guide plate 1 after the second time is the critical angle of the light guide plate 1. Since the angle is 42 °, the area of the light guide plate 1 facing the lamp device 2 becomes large, light from the lamp device 2 can be efficiently taken in, and the brightness on the main surface 1a of the light guide plate 1 can be improved.

【0031】さらに、他の実施例を図4を参照して説明
する。
Further, another embodiment will be described with reference to FIG.

【0032】この図4に示す実施例は、図1に示す実施
例において、散乱体5aを導光板1の主面1bの全面に形成
するとともに、蛍光ランプ3と導光体1の光入射主面1c
との間に、プリズムシート8を配設したものである。
The embodiment shown in FIG. 4 is the same as the embodiment shown in FIG. 1 except that the scatterer 5a is formed on the entire main surface 1b of the light guide plate 1 and the main light incidence of the fluorescent lamp 3 and the light guide 1 is performed. Face 1c
The prism sheet 8 is disposed between the above and the above.

【0033】図において、ランプ装置2からプリズムシ
ート8を介して導光板1に入射する光の反射点Aの入射
角を45°とする。この場合、臨界角は、28.33°
になり、2回目以降の導光板1の内面での全反射におけ
る反射点Cでの入射角を導光板1の臨界角を42°にす
るには、反射点Bでの入射角を51.84°にすればよ
い。そして、反射点Bでの入射角を51.84°にする
には、反射点Bの傾斜を23.5°持たせればよいの
で、肉厚部1dの角度を3°に設定し、ランプ装置2と向
かい合う部分だけを広げることができる。
In the figure, the incident angle of the reflection point A of the light incident on the light guide plate 1 from the lamp device 2 through the prism sheet 8 is 45 °. In this case, the critical angle is 28.33 °
Therefore, in order to make the incident angle at the reflection point C in the total internal reflection of the light guide plate 1 after the second time the critical angle of the light guide plate 1 to be 42 °, the incident angle at the reflection point B is 51.84. Set it to °. Then, in order to set the incident angle at the reflection point B to 51.84 °, it suffices that the reflection point B has an inclination of 23.5 °. Therefore, the angle of the thick portion 1d is set to 3 °, and the lamp device is set. Only the part facing 2 can be widened.

【0034】また、いずれの実施例の場合でも、最近で
は照明を前面に光を出すために導光板1の主面1aの前面
に拡散シート、プリズムシートを配置することが多いた
め、ランプ装置2と対向する部分だけを広げても全体の
導光板1の厚みを保つことはできる。
Further, in any of the embodiments, recently, in order to emit light to the front surface for illumination, a diffusion sheet and a prism sheet are often arranged on the front surface of the main surface 1a of the light guide plate 1. The thickness of the entire light guide plate 1 can be maintained even if only the portion facing the is widened.

【0035】また、導光板1はアクリル樹脂に限るもの
ではなく、屈折率1.5前後のガラスでもよい。さら
に、屈折率の大きい導光板を用いれば余裕の角度がさら
に増加させることができ、より薄い導光板でも高い輝度
を保つことができる。
The light guide plate 1 is not limited to the acrylic resin, but may be glass having a refractive index of about 1.5. Furthermore, if a light guide plate having a large refractive index is used, the margin angle can be further increased, and high brightness can be maintained even with a thinner light guide plate.

【0036】上記実施例によれば、入射効率が高まるた
め、薄型軽量の導光板を使用しても、液晶表示装置に使
用した場合、戸外などの明るい場所での使用が可能な液
晶表示装置を構成することができる。
According to the above-mentioned embodiment, since the incidence efficiency is improved, even when a thin and lightweight light guide plate is used, when it is used in a liquid crystal display device, a liquid crystal display device which can be used in a bright place such as outdoors is provided. Can be configured.

【0037】[0037]

【発明の効果】本発明の光源装置によれば、導光板は、
光入射主面から入射される光源からの光が一方の主面で
反射されて他方の主面に到達する場合、この反射された
光の一方の主面への入射角がこの導光板の屈折率により
規定される臨界角以下であるため、入射された光を効率
よく一方の主面から他方の主面に反射できるため、光源
からの光量が同じならば、導光板の明るさをより明るく
できる。
According to the light source device of the present invention, the light guide plate is
When the light from the light source incident from the light incident main surface is reflected on one main surface and reaches the other main surface, the angle of incidence of this reflected light on one main surface is the refraction of this light guide plate. Since the incident angle is less than the critical angle specified by the ratio, incident light can be efficiently reflected from one main surface to the other main surface, so if the amount of light from the light source is the same, the brightness of the light guide plate will be brighter. it can.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の光源装置の一実施例の液晶表示装置を
示す断面図である。
FIG. 1 is a cross-sectional view showing a liquid crystal display device of an embodiment of a light source device of the present invention.

【図2】同上他の実施例を示す断面図である。FIG. 2 is a sectional view showing another embodiment of the same.

【図3】同上また他の実施例を示す断面図である。FIG. 3 is a sectional view showing another embodiment of the above.

【図4】同上さらに他の実施例を示す断面図である。FIG. 4 is a sectional view showing still another embodiment of the same.

【図5】従来例の液晶表示装置を示す断面図である。FIG. 5 is a cross-sectional view showing a conventional liquid crystal display device.

【符号の説明】[Explanation of symbols]

1 導光板 1a,1b 主面 1c 光入射主面 2 光源としてのランプ装置 1 light guide plate 1a, 1b main surface 1c light incident main surface 2 lamp device as light source

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 表面および背面にそれぞれ一方および他
方の主面が形成され側面に光入射主面が形成された平板
状の導光板と、この導光板の光入射主面に対向して配置
された光源とを具備し、 前記導光板は、前記光入射主面から入射される光源から
の光が前記一方の主面で反射されて前記他方の主面に到
達する場合、この反射された光の前記一方の主面への入
射角がこの導光板の屈折率により規定される臨界角以下
であることを特徴とした光源装置。
1. A flat light guide plate having one and the other main surfaces formed on the front surface and the back surface and a light incident main surface formed on the side surface, and a light guide plate disposed opposite to the light incident main surface of the light guide plate. When the light from the light source incident from the light incident main surface is reflected on the one main surface and reaches the other main surface, the reflected light is The light source device is characterized in that the angle of incidence on the one main surface is less than or equal to a critical angle defined by the refractive index of the light guide plate.
JP6231282A 1994-09-27 1994-09-27 Light source device Pending JPH0894846A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6231282A JPH0894846A (en) 1994-09-27 1994-09-27 Light source device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6231282A JPH0894846A (en) 1994-09-27 1994-09-27 Light source device

Publications (1)

Publication Number Publication Date
JPH0894846A true JPH0894846A (en) 1996-04-12

Family

ID=16921166

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6231282A Pending JPH0894846A (en) 1994-09-27 1994-09-27 Light source device

Country Status (1)

Country Link
JP (1) JPH0894846A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130074552A (en) * 2011-12-26 2013-07-04 엘지디스플레이 주식회사 Liquid crystal display device
US12109487B2 (en) 2016-07-26 2024-10-08 Sony Interactive Entertainment Inc. Operation device and method for controlling the same

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04333803A (en) * 1991-05-10 1992-11-20 Sumitomo Chem Co Ltd Photoconductor for plane illumination device
JPH05307365A (en) * 1992-05-01 1993-11-19 Nippondenso Co Ltd Surface light emission device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04333803A (en) * 1991-05-10 1992-11-20 Sumitomo Chem Co Ltd Photoconductor for plane illumination device
JPH05307365A (en) * 1992-05-01 1993-11-19 Nippondenso Co Ltd Surface light emission device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130074552A (en) * 2011-12-26 2013-07-04 엘지디스플레이 주식회사 Liquid crystal display device
US12109487B2 (en) 2016-07-26 2024-10-08 Sony Interactive Entertainment Inc. Operation device and method for controlling the same

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