JP2569034B2 - Liquid crystal display - Google Patents

Liquid crystal display

Info

Publication number
JP2569034B2
JP2569034B2 JP62014063A JP1406387A JP2569034B2 JP 2569034 B2 JP2569034 B2 JP 2569034B2 JP 62014063 A JP62014063 A JP 62014063A JP 1406387 A JP1406387 A JP 1406387A JP 2569034 B2 JP2569034 B2 JP 2569034B2
Authority
JP
Japan
Prior art keywords
light
light source
liquid crystal
guide plate
crystal display
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.)
Expired - Lifetime
Application number
JP62014063A
Other languages
Japanese (ja)
Other versions
JPS63182628A (en
Inventor
昭人 滝沢
広幸 宮崎
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP62014063A priority Critical patent/JP2569034B2/en
Publication of JPS63182628A publication Critical patent/JPS63182628A/en
Application granted granted Critical
Publication of JP2569034B2 publication Critical patent/JP2569034B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133615—Edge-illuminating devices, i.e. illuminating from the side
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133603—Direct backlight with LEDs
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133613—Direct backlight characterized by the sequence of light sources

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Light Guides In General And Applications Therefor (AREA)
  • Liquid Crystal (AREA)
  • Planar Illumination Modules (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、透過形液晶表示装置の背面光源として好適
な、明るく均一な輝度分布が得られる液晶表示装置用背
面光源板に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear light source plate for a liquid crystal display device suitable for a rear light source of a transmission type liquid crystal display device and capable of obtaining a bright and uniform luminance distribution.

〔従来の技術〕[Conventional technology]

従来から、例えばプリント配線板に取付けて使用し、
外光に十分照射されない状況下でも明るく見えるような
透過形液晶表示装置の背面光源として用いるために、透
光性良好なプラスチック材などで「導光板」を作成し、
その対向する２辺に沿って発光ダイオードなどの光源を
配設し、これら２辺の断面から導光板の内部に光を入射
させて板の表面が明るく輝いて見えるようにしたものは
存在していた。このようなものの場合、たとえば特開昭
57−120433号公報に開示されているように、比較的均一
な輝度分布が得られるように、導光板の表面にいわゆる
艶消し処理を施して光を拡散させることは行われていた
が、発光ダイオード素子の配置の仕方に対しては、特別
な配慮はされていなかった。Conventionally, it is used by attaching it to a printed wiring board, for example.
In order to use it as a back light source of a transmissive liquid crystal display device that looks bright even under conditions where it is not sufficiently exposed to external light, create a `` light guide plate '' with plastic material with good translucency,
Some light sources such as light-emitting diodes are arranged along two opposing sides, and light enters the inside of the light guide plate from the cross section of these two sides so that the surface of the plate looks bright and bright. Was. In such a case, for example,
As disclosed in JP-A-57-120433, so-called matting treatment was performed on the surface of the light guide plate to diffuse light so that a relatively uniform luminance distribution could be obtained. No special consideration was given to the arrangement of the diode elements.

第２図は従来の透過形液晶表示装置の背面光源板の一
例を示し、第２図（ａ）は其の上面図、第２図（ｂ）は
其の側面図である。この例では、背面光源板２はプリン
ト配線板６に取付けられており、発光ダイオード（LE
D）１が、矩形状の導光板５の対向する２辺に沿って頭
部を埋め込んで一定の間隔毎に相対向させて配設してあ
る。LED1をこのように配置したので、対向する２個のLE
Dからの強い照射が重なる部分は、点を散布させて表示
した形状の明るい部分４を生じ、対向する２個のLEDの
どちらからも弱い照射しか受けない部分は、クロスハッ
チングで表示した形状の暗い部分３を生じ、導光板５の
表面に艶消し処理を施しても、導光板の表面に輝度の不
均一分布が発生することは防げない。なお、この図は、
明るい部分や暗い部分が発生することを明示するために
多少誇張して描いてあり、実際には、例えばLEDが光を
発散する角度をもっと拡げれば、これほど判然とした暗
い部分は生じない。尚、導光板の相対向する２辺に複数
の点光源を配置するにあたり、各辺の各点光源の位置が
若干ずれている従来技術としては、実開昭59−33079号
公報、実開昭59−35976号公報、特開昭60−159883号公
報、特開昭61−15176号公報等が挙げられるが、いずれ
の公報にも、導光板の一方の辺の断面に設けた点光源が
他方の辺の断面に設けた点光源の中間正面に位置するも
のはない。FIG. 2 shows an example of a rear light source plate of a conventional transmission type liquid crystal display device. FIG. 2 (a) is a top view thereof, and FIG. 2 (b) is a side view thereof. In this example, the rear light source plate 2 is attached to a printed wiring board 6 and a light emitting diode (LE)
D) 1 is disposed such that the head is buried along two opposing sides of the rectangular light guide plate 5 so as to face each other at regular intervals. Since LED1 is arranged in this way, the two LEs facing each other
The part where the strong irradiation from D overlaps produces a bright part 4 of the shape displayed by scattered points, and the part that receives only weak irradiation from both of the two opposing LEDs has the shape shown by cross hatching. Even if the dark portions 3 are formed and the surface of the light guide plate 5 is subjected to a matting process, it is not possible to prevent the occurrence of uneven distribution of luminance on the surface of the light guide plate. This figure is
It has been slightly exaggerated to show that light and dark areas will occur, but in reality, if you increase the angle at which the LED emits light, for example, there will be no noticeable dark areas . In arranging a plurality of point light sources on two opposing sides of the light guide plate, the prior art in which the positions of the point light sources on each side are slightly shifted is disclosed in Japanese Utility Model Laid-Open Publication No. JP-A-59-35976, JP-A-60-159883, JP-A-61-15176, and the like.In each of these publications, a point light source provided on a cross section of one side of a light guide plate is the other. Nothing is located in the middle front of the point light source provided in the cross section of the side.

〔発明が解決しようとする問題点〕[Problems to be solved by the invention]

本発明は、上記のように、従来の透過形液晶表示装置
の背面光源板では均一な輝度分布が得られないという問
題点を解決し、光源の配置に配慮して、均一な輝度分布
が得られるようにした背面光源板を提供することを目的
とする。As described above, the present invention solves the problem that a uniform luminance distribution cannot be obtained with the rear light source plate of the conventional transmission type liquid crystal display device, and obtains a uniform luminance distribution in consideration of the arrangement of the light sources. It is an object of the present invention to provide a rear light source plate that can be used.

〔問題点を解決するための手段〕[Means for solving the problem]

上記問題点を解決するために本発明においては、透光
性素材よりなる導光板の相対向する２辺夫々の端部断面
に接して又は埋めて、複数個の微小光源を、その光が導
光板内部に入射するように、かつ、一定の間隔毎に、一
方の辺の断面に設けられたものは他方の辺の断面に設け
たものの中間正面に位置するように配設することとし
た。In order to solve the above-mentioned problems, in the present invention, a plurality of minute light sources are guided by contacting or burying end cross sections of two opposing sides of a light guide plate made of a translucent material. The components provided on the cross section of one side are arranged so as to be incident on the inside of the light plate and at regular intervals so as to be located at the intermediate front of the components provided on the cross section of the other side.

〔作用〕[Action]

上記のような手段をとれば、矩形状導光板の対向する
２辺に沿って一定の間隔毎に配設された微小光源群によ
り、一方の辺に配置された微小光源の光が照射し難い部
分には他方の辺に配置された微小光源からの光が良く照
射するようになり、互いに補って暗い部分が生じなくな
る。また、微小光源が実際に光を放射する個所は極めて
小さく点光源とみなせるが、通常、発光素子としては、
更に適当な光学系を付加して所望範囲に光を発散させる
ようにしている。本発明に関連して此の光学系の設計を
適切に行えば、各微小光源が、それぞれ対向する辺に配
設された微小光源からの光の照射が弱いい範囲を丁度照
射するようにすることが出来る。このようにすれば、複
数の微小光源からの照射光が重なった局部的に明るい部
分が生じない。According to the above-described means, it is difficult to irradiate the light of the minute light source arranged on one side by the minute light source group arranged at regular intervals along two opposing sides of the rectangular light guide plate. Light from the minute light source arranged on the other side is radiated well to the portion, and a dark portion is not generated by complementing each other. In addition, the place where the minute light source actually emits light can be regarded as a point light source, but usually, as a light emitting element,
Further, an appropriate optical system is added to diverge light to a desired range. If the design of the optical system is properly performed in connection with the present invention, each of the minute light sources is configured to irradiate only a weak range of light from the minute light source disposed on the opposite side. I can do it. With this configuration, a locally bright portion where the irradiation lights from the plurality of minute light sources overlap does not occur.

〔実施例〕〔Example〕

第１図（ａ）は本発明における微小光源として発光ダ
イオードを用いた一実施例の上面図、第１図（ｂ）は同
実施例の側面図である。符号は第２図の場合と同じもの
を指す。この実施例ではLED1の光学系を、一方の辺に沿
って配列したLEDからの光照射が強い部分が、他方の辺
に沿って配列したLEDからの光照射が弱い部分に丁度う
まく重なるように設計してあるので、両端部に暗い部分
３が生じている以外、どこにも、特に暗い部分も、特に
明るい部分も、生じていない。なお、上記実施例におい
ては、微小光源として発光ダイオードを用いたが、その
他タングステンランプであってもよいことは勿論であ
る。本発明は光源として用いる微小光源を導光板に対し
て如何に配列するかに関するものであって、実際に一様
な輝度分布を得るためには、更にに導光板に表面処理を
施すことが有効である。点光源からの光は、光源からの
距離が遠くなるのに伴って弱くなるから、光源からの距
離が遠い所ほど、導光板内部を透過して来た光が、導光
板の表面から外部へ散乱反射されて放射される割合が増
加するように、例えば光を散乱反射させる表面粗さの程
度すなわち凹凸の程度が激しくなるようにするなどの導
光板の表面処理に対する配慮が必要である。FIG. 1A is a top view of one embodiment using a light emitting diode as a minute light source in the present invention, and FIG. 1B is a side view of the embodiment. The reference numerals indicate the same ones as in FIG. In this embodiment, the optical system of LED 1 is configured such that a portion where light irradiation from LEDs arranged along one side is strong overlaps with a portion where light irradiation from LEDs arranged along the other side is weak just right. Due to the design, there is no particularly dark or particularly bright portion except for the dark portions 3 at both ends. In the above embodiment, the light emitting diode is used as the minute light source, but it goes without saying that a tungsten lamp may be used. The present invention relates to a method of arranging a small light source used as a light source with respect to a light guide plate, and it is effective to further perform a surface treatment on the light guide plate in order to actually obtain a uniform luminance distribution. It is. Light from a point light source becomes weaker as the distance from the light source increases, so that the farther from the light source, the more light transmitted through the inside of the light guide plate moves from the surface of the light guide plate to the outside. Consideration must be given to the surface treatment of the light guide plate, such as increasing the degree of surface roughness that scatters and reflects light, ie, the degree of irregularities, so that the ratio of scattered reflection and radiation increases.

〔発明の効果〕〔The invention's effect〕

以上説明したように本発明によれば、極めて簡単な手
段によって一様な輝度分布で発光する液晶表示装置用背
面光源板が得られる。As described above, according to the present invention, a rear light source plate for a liquid crystal display device that emits light with a uniform luminance distribution can be obtained by extremely simple means.

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

第１図（ａ）は本発明一実施例の上面図、第１図（ｂ）
は同実施例の側面図、第２図（ａ）は従来の例の上面
図、第２図（ｂ）は其の側面図である。 １……LED、２……背面光源板、３……暗い部分、４…
…明るい部分、５……導光板。FIG. 1 (a) is a top view of one embodiment of the present invention, and FIG. 1 (b).
2 is a side view of the embodiment, FIG. 2 (a) is a top view of a conventional example, and FIG. 2 (b) is a side view thereof. 1 ... LED, 2 ... Back light source plate, 3 ... Dark part, 4 ...
... bright parts, 5 ... light guide plate.

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】液晶セルと、該液晶セルの裏面偏光板の背
後に配置されて光源となる矩形状の背面光源板とを有す
る透過形の液晶表示装置において、透光性素材よりなる
導光板の相対向する２辺それぞれの端部断面に接して又
は埋めて、複数個の発光ダイオードなどの微小光源を、
その光が導光板内部へ入射するように、かつ、一定の間
隔毎に、一方の辺の断面を設けた各光源は他方の辺の断
面に設けた各光源の中間正面に位置するように配設した
ことを特徴とする液晶表示装置。1. A transmissive liquid crystal display device having a liquid crystal cell and a rectangular rear light source plate disposed behind a rear polarizer of the liquid crystal cell and serving as a light source, wherein a light guide plate made of a light transmitting material is provided. A small light source, such as a plurality of light emitting diodes,
Each light source having a cross section on one side is arranged so that the light is incident on the inside of the light guide plate and at regular intervals so that the light source is located in the middle front of each light source provided on the cross section on the other side. A liquid crystal display device, comprising:
JP62014063A 1987-01-26 1987-01-26 Liquid crystal display Expired - Lifetime JP2569034B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62014063A JP2569034B2 (en) 1987-01-26 1987-01-26 Liquid crystal display

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62014063A JP2569034B2 (en) 1987-01-26 1987-01-26 Liquid crystal display

Publications (2)

Publication Number Publication Date
JPS63182628A JPS63182628A (en) 1988-07-27
JP2569034B2 true JP2569034B2 (en) 1997-01-08

Family

ID=11850630

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62014063A Expired - Lifetime JP2569034B2 (en) 1987-01-26 1987-01-26 Liquid crystal display

Country Status (1)

Country Link
JP (1) JP2569034B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4042687B2 (en) 2003-12-15 2008-02-06 ソニー株式会社 Lighting device and backlight device
CN102483542B (en) * 2009-08-27 2015-01-21 Lg电子株式会社 Backlight unit and display device

Also Published As

Publication number Publication date
JPS63182628A (en) 1988-07-27

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