JPH0996814A - Illumination device, back light and liquid crystal display device - Google Patents
Illumination device, back light and liquid crystal display deviceInfo
- Publication number
- JPH0996814A JPH0996814A JP7254186A JP25418695A JPH0996814A JP H0996814 A JPH0996814 A JP H0996814A JP 7254186 A JP7254186 A JP 7254186A JP 25418695 A JP25418695 A JP 25418695A JP H0996814 A JPH0996814 A JP H0996814A
- Authority
- JP
- Japan
- Prior art keywords
- light
- transparent adhesive
- light guide
- control plate
- adhesive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、照明装置、この照
明装置を利用したバックライトおよびこのバックライト
を利用した液晶表示装置に関する。The present invention relates to a lighting device, a backlight using the lighting device, and a liquid crystal display device using the backlight.
【０００２】[0002]
【従来の技術】従来、この種のバックライトは導光板の
背面に白色のインクを印刷し、この白色部分の光拡散反
射を利用したり、あるいは成形導光板に円錐状の凹部又
はＶ溝を設けて傾斜部分を利用して光を反射させて、導
光板前面に光を出射していた。しかし、この方法では拡
散光が前面に出射されるので、高い輝度が得られないこ
とから、最近では導光板の側面側より光を入光させ、複
数の凸レンズ部とプリズム状凸部とを連設した表裏両面
を合体した樹脂製の集光シートを導光板の出光面上に貼
り付け、この裏面のプリズム状凸部側から光をシート内
に導き、凸レンズ部側表面にて法線方向に光線の方向を
変更する機能により従来の方法に比べ３倍から８倍の輝
度が得られるものが提案されている。その一例として
は、米国特許第５３９６３５０号明細書と図面に記載さ
れたバックライトがある。2. Description of the Related Art Conventionally, a backlight of this type has a white ink printed on the back surface of a light guide plate to utilize the light diffuse reflection of the white portion, or a conical recess or V groove is formed on a molded light guide plate. The light is reflected by utilizing the inclined portion and is emitted to the front surface of the light guide plate. However, in this method, since diffused light is emitted to the front surface, high brightness cannot be obtained, so recently, light is incident from the side surface side of the light guide plate to connect a plurality of convex lens portions and prismatic convex portions. A resin condensing sheet that combines both front and back sides is attached on the light exit surface of the light guide plate, and light is guided from the prismatic convex side of this back surface into the sheet, and in the normal direction on the convex lens side surface. It has been proposed that a function of changing the direction of a light beam can obtain a brightness which is 3 to 8 times that of a conventional method. One example is the backlight described in US Pat. No. 5,396,350 and the drawings.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、このよ
うな従来のバックライトでは、導光体の出光面上に集光
シートを単に接着剤により接着しているだけであるの
で、過酷な環境試験によっては集光シートが剥離して光
の出射が無くなり、バックライトとしても均一な発光面
が得られなくなるという課題がある。However, in such a conventional backlight, since the light-condensing sheet is simply adhered to the light-exiting surface of the light guide member with an adhesive, it is necessary to perform a harsh environmental test. However, there is a problem in that the light-collecting sheet is peeled off so that light is not emitted, and a uniform light emitting surface cannot be obtained as a backlight.
【０００４】そこで本発明の目的は、過酷な環境試験に
よっても集光シートと導光体とが剥れずに、接着状態を
長期間安定して確保することができる照明装置，バック
ライトおよび液晶表示装置を提供することを目的とす
る。Therefore, an object of the present invention is to provide a lighting device, a backlight, and a liquid crystal display, which can secure a bonded state for a long period of time without the light-condensing sheet and the light guide body being separated from each other even under a severe environmental test. The purpose is to provide a device.
【０００５】[0005]
【課題を解決するための手段】本発明は、従来のバック
ライトの課題が、信頼性試験で導光板から光制御板が剥
れるのは、これらの接合界面の密着性が問題になること
が多く、この密着性の悪さは接合面の端部から接着剤の
性質が劣化し接着力が低下して剥れが生じることが多い
点に着目してなされたものであり、次のように構成され
る。SUMMARY OF THE INVENTION In the present invention, the problem of the conventional backlight is that the light control plate is peeled off from the light guide plate in the reliability test because the adhesion of these bonding interfaces becomes a problem. This poor adhesion is due to the fact that the properties of the adhesive deteriorate from the end of the joint surface and the adhesive strength often decreases, causing peeling. To be done.
【０００６】請求項１記載の発明は、側面，背面および
出光面を有する導光体と；導光体の側面側に配設された
光源と；複数のレンズ状凸部とプリズム状凸部とを表面
と裏面とにそれぞれ連設した光制御板と；導光体の出光
面上に塗布されて、その塗布厚の５〜５０％の範囲まで
光制御板のプリズム状凸部側を圧入させて光制御板を導
光体の出光面上に接着する透明接着剤と；を具備してい
る。According to a first aspect of the present invention, a light guide having a side surface, a back surface, and a light exit surface; a light source disposed on the side surface of the light guide; a plurality of lens-shaped convex portions and prism-shaped convex portions; A light control plate having a front surface and a back surface connected to each other; applied on the light exit surface of the light guide and press-fitting the prism-shaped convex portion side of the light control plate up to a range of 5 to 50% of the applied thickness. And a transparent adhesive for adhering the light control plate to the light exit surface of the light guide.
【０００７】したがってこの発明によれば、導光体の出
光面上に塗布した透明接着剤に、その塗布厚の５〜５０
％まで光制御板のプリズム状凸部を圧入して接着してい
るので、接着面積を増大することができる。したがっ
て、接着剤の接着力を増大させることができると共に、
この接着剤の接着力の低下を抑制することができる。Therefore, according to the present invention, the transparent adhesive coated on the light emitting surface of the light guide has a coating thickness of 5 to 50.
%, The prism-shaped convex portions of the light control plate are press-fitted and bonded, so that the bonding area can be increased. Therefore, the adhesive strength of the adhesive can be increased, and
It is possible to suppress the decrease in the adhesive strength of the adhesive.
【０００８】請求項２記載の発明は、請求項１記載の発
明であって、さらに、透明接着剤は、導光体の出光面上
で波打つ波形に形成されて、この出光面との間に空隙を
形成している。According to a second aspect of the present invention, in addition to the first aspect of the invention, the transparent adhesive is formed in a wavy waveform on the light emitting surface of the light guide body, and is formed between the light emitting surface and the light emitting surface. It forms a void.
【０００９】したがって、この発明によれば、請求項１
記載の発明と同様の作用効果を奏することができるうえ
に、波形の透明性接着剤と導光体の出光面との間の空隙
に入射した光を、空気と導光体との屈折率との差により
出光面上で殆ど全反射させ、散乱を抑制することができ
る。したがって、出光面上の光の散乱による光のリーク
を防止することができるので、発光効率を向上させるこ
とができる。Therefore, according to the present invention, claim 1
In addition to being able to achieve the same effect as the invention described above, the light incident on the gap between the corrugated transparent adhesive and the light exit surface of the light guide has a refractive index between the air and the light guide. It is possible to suppress the scattering by causing almost total reflection on the light exit surface due to the difference of. Therefore, it is possible to prevent light leakage due to scattering of light on the light emitting surface, and thus it is possible to improve light emission efficiency.
【００１０】請求項３記載の発明は、請求項１または２
記載の発明であって、さらに、透明接着剤は、光制御板
のプリズム状凸部の頂端のみに塗布されている。[0010] The third aspect of the present invention is the first or second aspect.
In the invention described above, the transparent adhesive is applied only to the top ends of the prismatic convex portions of the light control plate.
【００１１】したがってこの発明によれば、光制御板の
プリズム状凸部の頂端のみに透明接着剤を塗布するの
で、光制御板の出光面全面に透明接着剤を塗布する場合
に比して透明接着剤の塗布量を節約できるうえに、プリ
ズム状凸部が位置すると予測される導光体の出光面上の
箇所に、透明接着剤をスポット的に塗布する場合に比し
て光制御板の位置決めを正確かつ簡単に行なうことがで
きる。Therefore, according to the present invention, since the transparent adhesive is applied only to the apexes of the prismatic convex portions of the light control plate, it is transparent as compared with the case where the transparent adhesive is applied to the entire light emitting surface of the light control plate. In addition to saving the amount of adhesive applied, in comparison with the case where a transparent adhesive is applied in spots on the light exit surface of the light guide where it is predicted that the prismatic protrusions will be located, The positioning can be performed accurately and easily.
【００１２】請求項４記載の発明は、請求項１ないし３
のいずれか一記載の発明であって、さらに、透明接着剤
は、シリコーン系であり、膜厚が２０〜３０μｍであ
る。The invention described in claim 4 is the first to third aspects of the present invention.
In any one of the inventions, the transparent adhesive is silicone-based and has a film thickness of 20 to 30 μm.
【００１３】したがってこの発明によれば、接着剤の膜
厚が厚過ぎると透過率が下がり、表示面の輝度が低下す
る。また、薄過ぎると信頼性試験で剥がれが発生し、十
分な接着強度が得られない。実験の結果、シリコーン系
接着剤の膜厚は２０〜３０μｍが最適である。Therefore, according to the present invention, when the film thickness of the adhesive is too thick, the transmittance is lowered and the brightness of the display surface is lowered. If it is too thin, peeling occurs in the reliability test, and sufficient adhesive strength cannot be obtained. As a result of the experiment, the film thickness of the silicone adhesive is optimally 20 to 30 μm.
【００１４】請求項５記載の発明は、請求項１ないし３
のいずれか一記載の発明であって、さらに、透明接着剤
は、アクリル系であり、膜厚が２０〜６０μｍである。[0014] The invention according to claim 5 provides the invention according to claims 1 to 3.
In any one of the inventions, the transparent adhesive is acrylic and has a film thickness of 20 to 60 μm.
【００１５】したがってこの発明によれば、接着剤の膜
厚が厚過ぎると透過率が下がり、表示面の輝度が低下す
る。また、薄過ぎると信頼性試験で剥がれが発生し、十
分な接着強度が得られない。実験の結果、アクリル系接
着剤の膜厚は２０〜６０μｍが最適である。Therefore, according to the present invention, if the film thickness of the adhesive is too thick, the transmittance is lowered and the brightness of the display surface is lowered. If it is too thin, peeling occurs in the reliability test, and sufficient adhesive strength cannot be obtained. As a result of the experiment, the film thickness of the acrylic adhesive is optimally 20 to 60 μm.
【００１６】請求項６記載の発明は、請求項１ないし５
のいずれか一記載の発明であって、さらに、光制御板が
ポリスチレン，ポリカーボネート，メチルペンテンポリ
マーのいずれかよりなる。The invention according to claim 6 is the invention according to claims 1 to 5.
In the invention described in any one of 1 to 3, the light control plate is further made of any one of polystyrene, polycarbonate, and methylpentene polymer.
【００１７】請求項７記載の発明は、請求項１ないし６
のいずれか一記載の発明であって、さらに、光制御板側
に配設される光拡散体と；導光体の背面側に配設される
反射体と；を具備している。The invention according to claim 7 is the invention according to claims 1 to 6.
The invention according to any one of the above, further comprising: a light diffuser disposed on the light control plate side; and a reflector disposed on the back side of the light guide.
【００１８】したがってこれらの発明によれば、請求項
１ないし６のいずれか一記載の発明に係る導光体と光制
御板とを有するので、この請求項１ないし６のいずれか
一記載の発明と同様の作用効果を奏することができる。Therefore, according to these inventions, since the light guide and the light control plate according to any one of claims 1 to 6 are provided, the invention according to any one of claims 1 to 6 is provided. The same operational effect as can be obtained.
【００１９】請求項８記載の発明は、請求項１ないし７
のいずれか一記載の照明装置と；導光体，光源，反射
体，光拡散体および光制御板を収容するケース本体と；
ケース本体に配設され、光源に高周波電力を供給する点
灯手段と；を具備している。The invention according to claim 8 is the invention according to claims 1 to 7.
And a case body that accommodates a light guide, a light source, a reflector, a light diffuser, and a light control plate;
The lighting unit is provided in the case body and supplies high-frequency power to the light source.
【００２０】請求項９記載の発明は、請求項１ないし８
のいずれか一記載の照明装置と；照明装置からの光によ
り照明される液晶表示手段と；を具備している。The invention according to claim 9 is the invention according to claims 1 to 8.
And a liquid crystal display unit that is illuminated by light from the illumination device.
【００２１】したがって請求項８記載のバックライトと
請求項９記載の液晶表示装置は請求項１ないし７のいず
れか一記載の発明の照明装置を有するので、これら照明
装置と同様の作用効果を奏することができる。Therefore, since the backlight according to claim 8 and the liquid crystal display device according to claim 9 have the illuminating device according to any one of claims 1 to 7, the same operational effects as those illuminating devices can be obtained. be able to.
【００２２】[0022]
【発明の実施の形態】以下、本発明の実施の形態を図１
〜図６に基づいて説明する。なお、図１〜図６中、同一
または相当部分には同一符号を付している。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
This will be described with reference to FIG. 1 to 6, the same or corresponding parts are designated by the same reference numerals.
【００２３】図１は図２の要部拡大図、図２は本発明の
第１の実施形態の縦断面図であり、これらの図におい
て、照明装置１は例えば透明アクリル樹脂製等により矩
形平板状に形成された導光板２の図中左右両側面の側方
に、例えば左右一対の直状の蛍光ランプ３ａ，３ｂを配
設している。FIG. 1 is an enlarged view of an essential part of FIG. 2, and FIG. 2 is a vertical sectional view of a first embodiment of the present invention. In these drawings, a lighting device 1 is a rectangular flat plate made of, for example, a transparent acrylic resin. For example, a pair of right and left straight fluorescent lamps 3a and 3b are arranged laterally on the left and right side surfaces of the light guide plate 2 formed in a shape.
【００２４】導光板２はその出光面２ａ上に、シリコー
ン系またはアクリル系の透明接着剤４を所要膜厚でほぼ
均等に塗布して、光制御板である集合シート５を接着し
て固定している。On the light exit surface 2a of the light guide plate 2, a silicone-based or acrylic-based transparent adhesive 4 is applied approximately evenly in a required film thickness, and an assembly sheet 5 as a light control plate is adhered and fixed. ing.
【００２５】集合シート５はＰＳ（ポリスチレン），Ｐ
Ｃ（ポリカーボネート），ＴＰＸ（メチルペンテンポリ
マー）等の合成樹脂によりシート状に形成され、その図
中上面５ａ（表面）に、図中上方に凸の円弧状の複数の
凸レンズ部６を横方向に所定のピッチで連設する一方、
図中下面５ｂ（導光板２の出光面２ａ側）に、複数の逆
台形楔状のプリズム状凸部７を横方向に所定のピッチで
連設している。つまり、これら複数の凸レンズ部６と複
数のプリズム状凸部７とを表裏５ａ，５ｂ面にそれぞれ
一体に形成している。The aggregate sheet 5 is made of PS (polystyrene), P
A sheet of synthetic resin such as C (polycarbonate) or TPX (methyl pentene polymer) is formed into a sheet shape, and a plurality of convex lens portions 6 in an arc shape convex upward in the figure are laterally formed on the upper surface 5a (surface) in the figure. While arranging at a predetermined pitch,
In the figure, a plurality of inverted trapezoidal wedge-shaped prism-shaped convex portions 7 are continuously arranged in a lateral direction at a predetermined pitch on a lower surface 5b (on the light emitting surface 2a side of the light guide plate 2). That is, the plurality of convex lens portions 6 and the plurality of prismatic convex portions 7 are integrally formed on the front and back surfaces 5a and 5b, respectively.
【００２６】そして、この集光シート５を導光板２の出
光面２ａ上に透明接着剤４により接着する場合は、ま
ず、導光板２の出光面２ａ上に、透明接着剤４を所定の
膜厚ｔａでほぼ均等に塗布する。When the light collecting sheet 5 is adhered onto the light exit surface 2a of the light guide plate 2 with the transparent adhesive 4, first, the transparent adhesive 4 is applied onto the light exit surface 2a of the light guide plate 2 by a predetermined film. It is applied with a thickness of ta almost evenly.
【００２７】次に、この透明接着剤４上に、集光シート
５を、そのプリズム状凸部７側を向けて載置し、この集
光シート５と導光板２とを図示しないプレス機等により
挟持して挟み圧力を加圧し、図１に示すように各プリズ
ム状凸部７が透明接着剤４内に、その膜厚ｔａの５〜５
０％の範囲ｔｂで圧入させた状態で乾燥固化させて固着
する。透明接着剤４がシリコーン系の場合は膜厚ｔａが
２０〜３０μｍが良好であり、アクリル系の場合は膜厚
ｔａが２０〜６０μｍが好適である。これら膜厚ｔａ
は、厚すぎると、光透過率が下がって出光面の輝度が低
下する一方、薄過ぎると、信頼性試験で剥れが発生し、
十分な装着強度が得られない。実験の結果、上記最適の
膜厚が得られた。Next, the light-condensing sheet 5 is placed on the transparent adhesive 4 with its prismatic convex portion 7 side facing, and the light-condensing sheet 5 and the light guide plate 2 are not shown in the drawing. The prismatic protrusions 7 are placed in the transparent adhesive 4 within a thickness of 5 to 5 of the film thickness ta as shown in FIG.
It is dried and solidified and fixed in a state of being press-fitted in the range of 0% tb. When the transparent adhesive 4 is of silicone type, the film thickness ta is preferably 20 to 30 μm, and when it is of acrylic type, the film thickness ta is preferably 20 to 60 μm. These film thickness ta
If the thickness is too thick, the light transmittance decreases and the brightness of the light emitting surface decreases, while if it is too thin, peeling occurs in the reliability test,
Sufficient mounting strength cannot be obtained. As a result of the experiment, the above optimum film thickness was obtained.
【００２８】照明装置１はこのように構成されているの
で、一対の蛍光ランプ３ａ，３ｂからの光は導光板２の
側面から、その内部へ入射され、その一部は導光板２の
底面でほぼ全反射されて出光面２ａ側へ導光され、さら
に、この出光面２ａから集光シート５内へ、複数のプリ
ズム状凸部６を形成している裏面５ｂ側から入射され、
集光シート５内を通って各レンズ状凸部６から法線方向
にほぼ平行光として出光される。Since the illuminating device 1 is constructed in this way, the light from the pair of fluorescent lamps 3a and 3b is incident on the inside of the side surface of the light guide plate 2, and part of it is on the bottom surface of the light guide plate 2. The light is almost totally reflected and guided to the light exit surface 2a side, and further enters from the light exit surface 2a into the light-condensing sheet 5 from the back surface 5b side forming the plurality of prismatic convex portions 6,
The light passes through the light-condensing sheet 5 and is emitted from each lens-shaped convex portion 6 as substantially parallel light in the normal direction.
【００２９】そして、この実施形態では集光シート５の
各プリズム状凸部７を透明接着剤４内へ、その膜厚ｔａ
の５〜５０％の範囲ｔｂで圧入して導光板２の出光面２
ａ上に集光シート５を接着しているので、集光シート５
の各プリズム状凸部７と透明接着剤４とが接触する面積
を増大させることができる。このために、集光シート５
と導光板２の出光面２ａとの接着力を増強させることが
できるので、この接合部の界面を長期間安定させること
ができ、導光板出光面２ａから集光シート５が剥離する
のを長期間有効に防止することができる。In this embodiment, each prismatic convex portion 7 of the light-condensing sheet 5 is placed in the transparent adhesive 4 and its film thickness ta is obtained.
5 to 50% of the range tb is press-fitted and the light exit surface 2 of the light guide plate 2 is pressed.
Since the light-condensing sheet 5 is adhered on a, the light-condensing sheet 5
It is possible to increase the area where each prismatic convex portion 7 and the transparent adhesive 4 come into contact with each other. For this purpose, the light collecting sheet 5
Since the adhesive force between the light guide plate 2 and the light exit surface 2a of the light guide plate 2 can be increased, the interface of this joint can be stabilized for a long period of time, and the light-condensing sheet 5 can be prevented from peeling off from the light guide plate light exit surface 2a. It can be effectively prevented for a period.
【００３０】つまり、本発明者等はこの照明装置１の環
境試験を実施した際に、集光シート５の導光板２への加
圧力を種々変化させて集光シート５と導光板２との接着
状態を調査した結果、集光シート５のプリズム状凸部７
が透明接着剤４の膜厚ｔａの５〜５０％まで圧入するこ
とで環境試験に十分耐え得ることを新たに知見して本発
明を完成した。That is, when the inventors of the present invention conducted an environmental test on the lighting device 1, the pressure applied to the light guide plate 2 of the light collecting sheet 5 was changed in various ways to form the light collecting sheet 5 and the light guide plate 2. As a result of investigating the adhesion state, the prismatic convex portion 7 of the light collecting sheet 5
The present invention was completed by newly discovering that by press-fitting up to 5 to 50% of the film thickness ta of the transparent adhesive 4, it is possible to sufficiently withstand the environmental test.
【００３１】図３は本発明の第２の実施形態の要部断面
図であり、この照明装置１Ａは集光シート５の各プリズ
ム状凸部７の頂端面のみに透明接着剤４を塗布した点に
特徴があり、これら各プリズム状凸部７を透明接着剤４
内に、その全膜厚ｔａの５〜５０％の範囲ｔｂで圧入し
て集光シート５を導光板２の出光面２ａ上に接着した点
は上記実施形態と同様である。FIG. 3 is a cross-sectional view of a main part of the second embodiment of the present invention. In this lighting device 1A, the transparent adhesive 4 is applied only to the top end surface of each prismatic convex portion 7 of the light collecting sheet 5. It is characterized by the fact that each of these prismatic convex portions 7 is attached to the transparent adhesive 4
The point that the light-condensing sheet 5 is adhered onto the light-exiting surface 2a of the light guide plate 2 by press-fitting in the range tb of 5 to 50% of the total film thickness ta is the same as in the above embodiment.
【００３２】したがってこの照明装置１Ａによれば、導
光板２の出光面２ａのほぼ全面に透明接着剤４を塗布す
る場合に比して透明接着剤４の塗布量を節約することが
できる。Therefore, according to this illuminating device 1A, the amount of the transparent adhesive 4 applied can be reduced as compared with the case where the transparent adhesive 4 is applied to almost the entire light exit surface 2a of the light guide plate 2.
【００３３】また、透明接着剤４を、導光板出光面２ａ
上の各プリズム状凸部７の頂端が位置することが予測さ
れる箇所にスポット的に塗布することによっても、接着
剤４の塗布量を節約することができるが、この方法では
接着剤４の塗布箇所と各プリズム状凸部７の位置がずれ
る場合がある。しかし、この実施形態によればかかる不
都合はなく、かかる位置決めを正確かつ簡単に行なうこ
とができる。Further, the transparent adhesive 4 is applied to the light exit surface 2a of the light guide plate.
The application amount of the adhesive 4 can be saved by applying the adhesive 4 in spots at the locations where the top ends of the respective prism-shaped convex portions 7 are expected to be located. There is a case where the application position and the position of each prismatic convex portion 7 are displaced. However, according to this embodiment, there is no such inconvenience, and such positioning can be performed accurately and easily.
【００３４】図４は本発明の第３の実施形態の要部縦断
面図であり、この照明装置１Ｂは集光シート５を導光板
２の出光面２ａ上に接着する透明接着剤４を、その出光
面２ａ上で図中上下方向で波打つ波形に形成して、この
波形の上方に凸の各円弧部４ａを隣り合うプリズム状凸
部７同士間の楔状凹部７ａ内で突設し、これらの各円弧
部４ａ内と出光面２ａとの間に、複数の小さい空隙８を
形成した点に特徴がある。上記各実施例と同様に、集光
シート５は、そのプリズム状凸部７を透明接着剤４内
に、その全膜厚ｔａの５〜５０％の範囲ｔｂ内で圧入さ
せて導光板２の出光面２ａ上に接着されている。FIG. 4 is a vertical cross-sectional view of a main part of a third embodiment of the present invention. In this illuminating device 1B, a transparent adhesive 4 for adhering a light-condensing sheet 5 on a light exit surface 2a of a light guide plate 2 is The light emitting surface 2a is formed in a wavy shape in the vertical direction in the figure, and each arcuate portion 4a that is convex upward in this waveform is provided in a wedge-shaped concave portion 7a between adjacent prism-shaped convex portions 7, The feature is that a plurality of small voids 8 are formed between each of the circular arc portions 4a and the light emitting surface 2a. Similar to each of the above-described embodiments, the light-condensing sheet 5 has the prism-shaped convex portions 7 pressed into the transparent adhesive 4 within a range tb of 5 to 50% of the total film thickness ta of the light guide plate 2. It is adhered on the light emitting surface 2a.
【００３５】そして、各空隙８内の空気と導光板２内の
屈折率には差があるので、図４に示すように各空隙８に
接する導光板出光面２ａに、導光板２内からの光が入射
されると、この出光面２ａで全反射され、散乱を抑制す
ることができる。このために、この出光面２ａでの光の
散乱により、集光シート５の出光表面５ａ以外へ散乱す
るのを抑制して出光表面５ａ上の輝度を向上させること
ができる。Since there is a difference between the air in each void 8 and the refractive index in the light guide plate 2, as shown in FIG. When light is incident, it is totally reflected by the light emitting surface 2a, and scattering can be suppressed. For this reason, it is possible to suppress the scattering of light on the light emitting surface 2a to other than the light emitting surface 5a of the light-condensing sheet 5 and improve the brightness on the light emitting surface 5a.
【００３６】図５は上記透明接着剤４を波形に形成する
方法の一例の一工程を示す縦断面図であり、これは集光
シート５のプリズム状凸部７側に塗布した透明接着剤４
に、保護シトー９を介してゴム状のローラまたはゴム製
波板１０をプレスすることにより接着剤４を波形に成形
する点に特徴がある。これによれば、透明接着剤４を正
確かつ簡単に波形に成形することができる。FIG. 5 is a vertical cross-sectional view showing one step of an example of a method for forming the transparent adhesive 4 in a corrugated form. This is the transparent adhesive 4 applied to the prismatic convex portion 7 side of the light collecting sheet 5.
In addition, it is characterized in that the adhesive 4 is formed into a corrugated shape by pressing a rubber-like roller or a rubber corrugated plate 10 through the protective cito 9. According to this, the transparent adhesive 4 can be accurately and easily formed into a corrugated shape.
【００３７】図６はこのように構成された照明装置１，
１Ａ，１Ｂのうちの例えば１を具備するバックライト１
１の分解斜視図である。バックライト１１は導光板２の
底面に反射シート１２を重ねる一方、導光板２の出光面
２ａ上に集光シート５と拡散シート１３とをこの順に順
次重ね合せて有底薄型角筒状のケース本体１４内に収容
している。ケース本体１４はポリカーボネート樹脂等の
合成樹脂で一体成形されており、図中上面をほぼ全面的
に開口させている。FIG. 6 shows a lighting device 1 having such a configuration.
Backlight 1 including, for example, 1 of 1A and 1B
1 is an exploded perspective view of FIG. In the backlight 11, a reflection sheet 12 is stacked on the bottom surface of the light guide plate 2, while a light-condensing sheet 5 and a diffusion sheet 13 are sequentially stacked on the light exit surface 2a of the light guide plate 2 in this order to form a bottomed thin prismatic case. It is housed in the main body 14. The case main body 14 is integrally molded with a synthetic resin such as a polycarbonate resin, and the upper surface of the case is almost entirely opened.
【００３８】また、導光板２の側面とケース本体１４の
内側壁との間には、例えばＬ字状の蛍光ランプ１５を収
容しているランプカバーＡ，Ｂ１６ａ，１６ｂを介在さ
せている。蛍光ランプ１５としては熱陰極型と冷陰極型
のいずれでもよいが、バックライトの光源としては立上
り特性が良く、しかも低消費電力が好まれるので、冷陰
極型が好ましい。ランプカバーＡ，Ｂ１６ａ，１６ｂ内
には背面が両面接着テープに形成されている銀シート１
７ａ，１７ｂが貼着されて反射面に形成されている。な
お、１８はＬ字状の蛍光ランプ１５に添設されてランプ
１５で発生するノイズをシールドする導電シート、１９
はフレームコーナである。Further, lamp covers A, B 16a, 16b housing, for example, L-shaped fluorescent lamps 15 are interposed between the side surface of the light guide plate 2 and the inner side wall of the case body 14. The fluorescent lamp 15 may be either a hot-cathode type or a cold-cathode type, but a cold-cathode type is preferable as a light source of a backlight because it has good rising characteristics and low power consumption. Inside the lamp covers A, B 16a, 16b, a silver sheet 1 whose back surface is formed with double-sided adhesive tape 1
7a and 17b are attached and formed on the reflecting surface. Reference numeral 18 is a conductive sheet attached to the L-shaped fluorescent lamp 15 to shield noise generated in the lamp 15.
Is the frame corner.
【００３９】蛍光ランプ１５には図示しない点灯装置を
電気的に接続しており、この点灯装置から蛍光ランプ１
５に高周波電力を安定的に給電して安定的に点灯させる
ようになっている。この点灯装置もケース本体１４に装
着される。A lighting device (not shown) is electrically connected to the fluorescent lamp 15. From this lighting device, the fluorescent lamp 1 is connected.
High-frequency power is stably supplied to 5 to be lit stably. This lighting device is also mounted on the case body 14.
【００４０】そして、拡散シート１３上に、図示しない
液晶駆動回路を具備した液晶表示パネル２０を設けるこ
とにより、液晶表示装置に構成することができる。By providing the liquid crystal display panel 20 having a liquid crystal drive circuit (not shown) on the diffusion sheet 13, a liquid crystal display device can be constructed.
【００４１】[0041]
【発明の効果】以上説明したように本願の請求項１記載
の発明は、導光体の出光面上に塗布した透明接着剤に、
その塗布厚の５〜５０％まで光制御板のプリズム状凸部
を圧入して接着しているので、接合面積を増大すること
ができる。このために、導光体と光制御板との接着剤の
接着力を増大させることができると共に、この接着剤の
接着力の低下を抑制することができる。As described above, the invention according to claim 1 of the present application provides a transparent adhesive coated on the light emitting surface of the light guide,
Since the prism-shaped convex portions of the light control plate are press-fitted and bonded to 5 to 50% of the coating thickness, the bonding area can be increased. Therefore, it is possible to increase the adhesive force of the adhesive between the light guide and the light control plate, and it is possible to suppress the decrease in the adhesive force of the adhesive.
【００４２】請求項２記載の発明によれば、請求項１記
載の発明と同様の作用効果を奏することができるうえ
に、波形の透明性接着剤と導光体の出光面との間の空隙
に入射した光を、空気と導光体との屈折率との差により
出光面上で殆ど全反射させ、散乱を抑制することができ
る。したがって、出光面上の光の散乱による光のリーク
を防止することができるので、発光効率を向上させるこ
とができる。According to the second aspect of the present invention, the same operational effect as that of the first aspect of the present invention can be obtained, and the gap between the corrugated transparent adhesive and the light exit surface of the light guide is obtained. The light incident on the light can be almost totally reflected on the light exit surface due to the difference in the refractive index between the air and the light guide, and scattering can be suppressed. Therefore, it is possible to prevent light leakage due to scattering of light on the light emitting surface, and thus it is possible to improve light emission efficiency.
【００４３】請求項３記載の発明によれば、光制御板の
プリズム状凸部の頂端のみに透明接着剤を塗布するの
で、光制御板の出光面全面に透明接着剤を塗布する場合
に比して透明接着剤の塗布量を節約できるうえに、プリ
ズム状凸部が位置すると予測される導光体の出光面上の
箇所に、透明接着剤をスポット的に塗布する場合に比し
て光制御板の位置決めを正確かつ簡単に行なうことがで
きる。According to the third aspect of the present invention, since the transparent adhesive is applied only to the apexes of the prism-shaped convex portions of the light control plate, it is compared with the case where the transparent adhesive is applied to the entire light emitting surface of the light control plate. In addition to saving the amount of transparent adhesive to be applied, it is possible to reduce the amount of transparent adhesive applied to spots on the light exit surface of the light guide where it is expected that prismatic convex parts will Positioning of the control plate can be performed accurately and easily.
【００４４】請求項４記載の発明は、請求項１ないし３
のいずれか一記載の発明であって、さらに、透明接着剤
は、シリコーン系であり、膜厚が２０〜３０μｍであ
る。The invention according to claim 4 is the same as claims 1 to 3.
In any one of the inventions, the transparent adhesive is silicone-based and has a film thickness of 20 to 30 μm.
【００４５】したがってこの発明によれば、接着剤の膜
厚が厚過ぎると透過率が下がり、表示面の輝度が低下す
る。また、薄過ぎると信頼性試験で剥がれが発生し、十
分な接着強度が得られない。実験の結果、シリコーン系
接着剤の膜厚は２０〜３０μｍが最適である。Therefore, according to the present invention, when the film thickness of the adhesive is too thick, the transmittance is lowered and the brightness of the display surface is lowered. If it is too thin, peeling occurs in the reliability test, and sufficient adhesive strength cannot be obtained. As a result of the experiment, the film thickness of the silicone adhesive is optimally 20 to 30 μm.
【００４６】請求項５記載の発明は、請求項１ないし３
のいずれか一記載の発明であって、さらに、透明接着剤
は、アクリル系であり、膜厚が２０〜６０μｍである。The invention according to claim 5 is the same as claims 1 to 3.
In any one of the inventions, the transparent adhesive is acrylic and has a film thickness of 20 to 60 μm.
【００４７】したがってこの発明によれば、接着剤の膜
厚が厚過ぎると透過率が下がり、表示面の輝度が低下す
る。また、薄過ぎると信頼性試験で剥がれが発生し、十
分な接着強度が得られない。実験の結果、アクリル系接
着剤の膜厚は２０〜６０μｍが最適である。Therefore, according to the present invention, if the film thickness of the adhesive is too thick, the transmittance is lowered and the brightness of the display surface is lowered. If it is too thin, peeling occurs in the reliability test, and sufficient adhesive strength cannot be obtained. As a result of the experiment, the film thickness of the acrylic adhesive is optimally 20 to 60 μm.
【００４８】請求項６および７記載の発明によれば、請
求項１ないし５のいずれか一記載の発明に係る導光体と
光制御板とを有するので、この請求項１ないし５のいず
れか一記載の発明と同様の作用効果を奏することができ
る。According to the sixth and seventh aspects of the invention, the light guide according to any one of the first to fifth aspects of the invention and the light control plate are included. Therefore, any one of the first to fifth aspects of the invention is provided. It is possible to obtain the same operational effects as the invention described in one.
【００４９】請求項８記載のバックライトと請求項９記
載の液晶表示装置は請求項１ないし７のいずれか一記載
の発明の照明装置を有するので、これら照明装置と同様
の作用効果を奏することができる。Since the backlight according to claim 8 and the liquid crystal display device according to claim 9 have the illuminating device according to any one of claims 1 to 7, the same operational effects as these illuminating devices can be obtained. You can
【図１】図２の要部拡大図。FIG. 1 is an enlarged view of a main part of FIG.
【図２】本発明の第１の実施形態に係る照明装置の概略
縦断面図。FIG. 2 is a schematic vertical cross-sectional view of the lighting device according to the first embodiment of the present invention.
【図３】本発明の第２の実施形態に係る照明装置の概略
縦断面図。FIG. 3 is a schematic vertical sectional view of an illumination device according to a second embodiment of the present invention.
【図４】本発明の第３の実施形態に係る照明装置の概略
縦断面図。FIG. 4 is a schematic vertical cross-sectional view of an illumination device according to a third embodiment of the present invention.
【図５】図４で示す波形接着剤を波形に形成するための
一工程の縦断面図。5 is a vertical cross-sectional view of one step for forming the corrugated adhesive shown in FIG. 4 into a corrugated shape.
【図６】本発明の第４の実施形態に係るバックライトま
たは液晶表示装置の分解斜視図。FIG. 6 is an exploded perspective view of a backlight or a liquid crystal display device according to a fourth embodiment of the present invention.
１，１Ａ，１Ｂ 照明装置 ２ 導光板 ２ａ 出光面 ３ａ，３ｂ 蛍光ランプ ４ 透明接着剤 ５ 集光シート ５ａ 集光シートの表面 ５ｂ 集光シートの裏面 ６ レンズ状凸部 ７ プリズム状凸部 ８ 空隙 １１ バックライト １２ 反射シート １３ 光拡散シート １４ ケース本体 １５ Ｌ字状蛍光ランプ ２０ 液晶表示パネル 1, 1A, 1B Illuminating device 2 Light guide plate 2a Light emitting surface 3a, 3b Fluorescent lamp 4 Transparent adhesive 5 Light collecting sheet 5a Light collecting sheet front surface 5b Light collecting sheet back surface 6 Lens-shaped convex portion 7 Prism-shaped convex portion 8 Void 11 Backlight 12 Reflective Sheet 13 Light Diffusing Sheet 14 Case Body 15 L-shaped Fluorescent Lamp 20 Liquid Crystal Display Panel
Claims (9)
と；導光体の側面側に配設された光源と；複数のレンズ
状凸部とプリズム状凸部とを表面と裏面とにそれぞれ連
設した光制御板と；導光体の出光面上に塗布されて、そ
の塗布厚の５〜５０％の範囲まで光制御板のプリズム状
凸部側を圧入させて光制御板を導光体の出光面上に接着
する透明接着剤と；を具備していることを特徴とする照
明装置。1. A light guide having a side surface, a back surface, and a light exit surface; a light source disposed on the side surface of the light guide; and a plurality of lens-shaped convex portions and prism-shaped convex portions on a front surface and a back surface. A light control plate, which is provided in series, is applied to the light exit surface of the light guide, and the prism-shaped convex portion side of the light control plate is press-fitted to the range of 5 to 50% of the applied thickness to guide the light control plate. An illuminating device comprising: a transparent adhesive that adheres to a light emitting surface of a light body.
つ波形に形成されて、この出光面との間に空隙を形成し
ていることを特徴とする請求項２記載の照明装置。2. The illuminating device according to claim 2, wherein the transparent adhesive is formed in a wavy shape on the light emitting surface of the light guide body to form a gap between the transparent adhesive and the light emitting surface. .
部の頂端のみに塗布されていることを特徴とする請求項
１または２記載の照明装置。3. The illumination device according to claim 1, wherein the transparent adhesive is applied only to the top ends of the prismatic convex portions of the light control plate.
厚が２０〜３０μｍであることを特徴とする請求項１な
いし３のいずれか一記載の照明装置。4. The lighting device according to claim 1, wherein the transparent adhesive is a silicone-based adhesive and has a film thickness of 20 to 30 μm.
が２０〜６０μｍであることを特徴とする請求項１ない
し３のいずれか一記載の照明装置。5. The lighting device according to claim 1, wherein the transparent adhesive is acrylic and has a film thickness of 20 to 60 μm.
ート，メチルペンテンポリマーのいずれかよりなること
を特徴とする請求項１ないし５のいずれか一記載の照明
装置。6. The lighting device according to claim 1, wherein the light control plate is made of polystyrene, polycarbonate, or methylpentene polymer.
光体の背面側に配設される反射体と；を具備しているこ
とを特徴とする請求項１ないし６のいずれか一記載の照
明装置。7. A light diffuser disposed on the light control plate side; and a reflector disposed on the back side of the light guide body. The lighting device according to any one of claims.
明装置と；導光体，光源，反射体，光拡散体および光制
御板を収容するケース本体と；ケース本体に配設され、
光源に高周波電力を供給する点灯手段と；を具備してい
ることを特徴とするバックライト。8. The lighting device according to claim 1, a case body that accommodates a light guide, a light source, a reflector, a light diffuser, and a light control plate;
And a lighting means for supplying high-frequency power to the light source.
明装置と；照明装置からの光により照明される液晶表示
手段と；を具備していることを特徴とする液晶表示装
置。9. A liquid crystal display device, comprising: the illuminating device according to claim 1; and a liquid crystal display means illuminated by light from the illuminating device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7254186A JPH0996814A (en) | 1995-09-29 | 1995-09-29 | Illumination device, back light and liquid crystal display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7254186A JPH0996814A (en) | 1995-09-29 | 1995-09-29 | Illumination device, back light and liquid crystal display device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0996814A true JPH0996814A (en) | 1997-04-08 |
Family
ID=17261437
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7254186A Pending JPH0996814A (en) | 1995-09-29 | 1995-09-29 | Illumination device, back light and liquid crystal display device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0996814A (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001307524A (en) * | 2000-04-21 | 2001-11-02 | Kuraray Co Ltd | Surface light source element |
| JP2003004950A (en) * | 2001-06-25 | 2003-01-08 | Goyo Paper Working Co Ltd | Laminated light transmission plate and method of manufacturing for the same |
| JP2005527864A (en) * | 2002-05-28 | 2005-09-15 | スリーエム イノベイティブ プロパティズ カンパニー | Multifunction optical assembly |
| JP2006324169A (en) * | 2005-05-20 | 2006-11-30 | Kuraray Co Ltd | Low-profile surface light source and liquid crystal display using this |
| JP2008027619A (en) * | 2006-07-18 | 2008-02-07 | Konica Minolta Holdings Inc | Surface emitter and display device using the same |
| JP2008204948A (en) * | 2007-01-25 | 2008-09-04 | Konica Minolta Holdings Inc | Surface light emitting body, display unit and lighting system using the same |
| JP2009018461A (en) * | 2007-07-11 | 2009-01-29 | Hitachi Ltd | Liquid-crystal display device |
| US7537369B2 (en) | 2003-02-28 | 2009-05-26 | Sharp Kabushiki Kaisha | Surface radiation conversion element, liquid crystal display device, and method of producing a surface radiation conversion element |
| JP2009237290A (en) * | 2008-03-27 | 2009-10-15 | Toppan Printing Co Ltd | Optical member, backlight unit using the same, and display |
| JP2009289444A (en) * | 2008-05-27 | 2009-12-10 | Sumitomo Bakelite Co Ltd | Optical sheet |
| CN107179577A (en) * | 2017-06-07 | 2017-09-19 | 武汉华星光电技术有限公司 | A kind of backlight module and display device |
| US10401551B2 (en) | 2017-06-07 | 2019-09-03 | Wuhan China Star Optoelectronics Technology Co., Ltd | Backlight module and display device |
-
1995
- 1995-09-29 JP JP7254186A patent/JPH0996814A/en active Pending
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001307524A (en) * | 2000-04-21 | 2001-11-02 | Kuraray Co Ltd | Surface light source element |
| JP4493884B2 (en) * | 2001-06-25 | 2010-06-30 | 五洋紙工株式会社 | Laminated light guide plate |
| JP2003004950A (en) * | 2001-06-25 | 2003-01-08 | Goyo Paper Working Co Ltd | Laminated light transmission plate and method of manufacturing for the same |
| JP2005527864A (en) * | 2002-05-28 | 2005-09-15 | スリーエム イノベイティブ プロパティズ カンパニー | Multifunction optical assembly |
| US7537369B2 (en) | 2003-02-28 | 2009-05-26 | Sharp Kabushiki Kaisha | Surface radiation conversion element, liquid crystal display device, and method of producing a surface radiation conversion element |
| JP2006324169A (en) * | 2005-05-20 | 2006-11-30 | Kuraray Co Ltd | Low-profile surface light source and liquid crystal display using this |
| JP2008027619A (en) * | 2006-07-18 | 2008-02-07 | Konica Minolta Holdings Inc | Surface emitter and display device using the same |
| JP4692426B2 (en) * | 2006-07-18 | 2011-06-01 | コニカミノルタホールディングス株式会社 | Surface light emitter and display device using the same |
| JP2008204948A (en) * | 2007-01-25 | 2008-09-04 | Konica Minolta Holdings Inc | Surface light emitting body, display unit and lighting system using the same |
| JP2009018461A (en) * | 2007-07-11 | 2009-01-29 | Hitachi Ltd | Liquid-crystal display device |
| JP2009237290A (en) * | 2008-03-27 | 2009-10-15 | Toppan Printing Co Ltd | Optical member, backlight unit using the same, and display |
| JP2009289444A (en) * | 2008-05-27 | 2009-12-10 | Sumitomo Bakelite Co Ltd | Optical sheet |
| CN107179577A (en) * | 2017-06-07 | 2017-09-19 | 武汉华星光电技术有限公司 | A kind of backlight module and display device |
| US10401551B2 (en) | 2017-06-07 | 2019-09-03 | Wuhan China Star Optoelectronics Technology Co., Ltd | Backlight module and display device |
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