WO2003025457A1 - Illumination unit and liquid crystal display apparatus comprising it - Google Patents

Illumination unit and liquid crystal display apparatus comprising it Download PDF

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Publication number
WO2003025457A1
WO2003025457A1 PCT/JP2002/009575 JP0209575W WO03025457A1 WO 2003025457 A1 WO2003025457 A1 WO 2003025457A1 JP 0209575 W JP0209575 W JP 0209575W WO 03025457 A1 WO03025457 A1 WO 03025457A1
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WO
WIPO (PCT)
Prior art keywords
guide plate
light guide
reflector
fluorescent lamp
light
Prior art date
Application number
PCT/JP2002/009575
Other languages
French (fr)
Japanese (ja)
Inventor
Yoshinori Yasuda
Original Assignee
Matsushita Electric Industrial 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 Matsushita Electric Industrial Co., Ltd. filed Critical Matsushita Electric Industrial Co., Ltd.
Publication of WO2003025457A1 publication Critical patent/WO2003025457A1/en

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0081—Mechanical or electrical aspects of the light guide and light source in the lighting device peculiar to the adaptation to planar light guides, e.g. concerning packaging
    • G02B6/0086—Positioning aspects
    • G02B6/0091—Positioning aspects of the light source relative to the light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
    • G02B6/0031—Reflecting element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0066—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form characterised by the light source being coupled to the light guide
    • G02B6/0068—Arrangements of plural sources, e.g. multi-colour light sources
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0066—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form characterised by the light source being coupled to the light guide
    • G02B6/007—Incandescent lamp or gas discharge lamp
    • G02B6/0071—Incandescent lamp or gas discharge lamp with elongated shape, e.g. tube

Definitions

  • the present invention relates to an illumination unit used for illumination of a liquid crystal display device and a liquid crystal display device using the same.
  • display devices for information devices such as laptop and notebook type word processors or personal computers display images on transmissive liquid crystal display panels by taking advantage of features such as light weight and thinness and low power consumption.
  • Liquid crystal display devices are frequently used.
  • this lighting unit is mainly of the edge light type, in which the light source is arranged on one side of the four side surfaces of the light guide plate.
  • Fig. 3 shows a cross-sectional view of a conventional edge light type lighting unit (on the side where fluorescent lamps are arranged).
  • a reflection sheet 2 having the same shape as the outer shape of the light guide plate 1 is provided on the back surface of the light guide plate 1 that has been equalized so as to effectively use the light emitted from the fluorescent lamp 8.
  • a resin film sheet 5 is installed on the main surface of the light guide plate 1, and the fluorescent lamp 8 arranged on the side surface of the light guide plate 1 is wrapped by the reflector 7, and the above members are resin outer frames. It is incorporated in the housing 3 and is fixed together with the back cover 6 with the screw 4.
  • the reflector 7 allows the light of the fluorescent lamp 8 to efficiently enter the incident end face (side surface) of the light guide plate 1.
  • the cross section of the reflector 7 is bent into a substantially U shape so as to surround the fluorescent lamp 8, and the light guide plate 1 It is arranged close to.
  • the reflector 7 is formed by depositing a highly reflective material such as silver or aluminum on a resin sheet.
  • a liquid crystal display panel 9 is arranged on the main surface side (upper in FIG. 3) of the lighting unit UT, and a metal frame 10 is attached to form a liquid crystal display device L.
  • the metal frame 10 is a frame that holds the liquid crystal display panel 9 and other components so as to be included from the front (main surface) side.
  • the light emitted from the fluorescent lamp 8 is directly or condensed by the reflector 7, is guided to the light guide plate 1, and is evenly transmitted to the entire rear surface of the liquid crystal display panel 9, thereby displaying the display surface of the liquid crystal display panel 9.
  • the characters and images projected on the screen become visible.
  • the thickness H 3 of the light guide plate 1 is usually In consideration of the incident efficiency, the dimension in the thickness direction of the light guide plate 1 at the opening of the reflector 7 must be larger than the dimension H1, so if a large number of large-diameter fluorescent lamps 8 are arranged, the light guide plate In the case where the light guide plate 1 is disposed on the light incident surface, the thickness H3 of the light guide plate 1 must be increased accordingly, which is against weight and thickness reduction.
  • the fluorescent lamp 8 There has been a problem that the efficiency of incidence of the light on the light guide plate 1 is reduced.
  • the reflector 7 that covers the fluorescent lamp 8 is We had to adopt a structure that was in close or partial contact.
  • the reflector 7 has a highly reflective material such as silver or aluminum deposited on a resin sheet, when a fluorescent lamp approaches or comes into contact with the fluorescent lamp, the leak current of the fluorescent lamp increases and the pink discharge (mercury) It was designed to easily cause problems such as the discharge of pink light when mercury disappears, and the lighting of lamp pieces (lighting at the end of lamp life).
  • the present invention solves the above problems, while maintaining the efficiency of the light from the fluorescent lamp to enter the light guide plate, and also eliminating the problems such as pink discharge and lamp lighting, and reducing the thickness of the light guide plate. It is an object of the present invention to provide a lighting unit which can achieve a long life and a light weight even when a fluorescent lamp having a large tube diameter is used, and a liquid crystal display device using the same.
  • the lighting unit according to claim 1 of the present invention includes a fluorescent lamp, a light guide plate that guides light from the fluorescent lamp to the main surface, and an opening that is arranged so as to surround the fluorescent lamp and faces a side surface of the light guide plate.
  • a lighting unit including a reflector having a light guide plate and a reflection sheet disposed on the back surface of the light guide plate so as to reflect light incident on the light guide plate to the main surface
  • the dimension of the light guide plate in the side surface thickness direction at the opening of the reflector is It is characterized by being smaller than the inner diameter of the part surrounding the fluorescent lamp.
  • the opening of the reflector becomes large in accordance with the tube diameter of the fluorescent lamp.
  • the incidence efficiency with respect to the light guide plate is reduced, and conversely, if the thickness of the light guide plate on the incident side is increased in accordance with the opening of the reflector, the entire lighting unit becomes thick and heavy.
  • the dimension (opening dimension) in the thickness direction of the side surface of the light guide plate at the opening of the reflector is smaller (shorter and smaller) than the inner diameter dimension of the portion surrounding the fluorescent lamp. The incidence efficiency on the light guide plate is hardly reduced.
  • the light guide plate can be designed to have a desired thickness. You.
  • the fluorescent lamp does not need to be made thinner than necessary, it is possible to design a longer life, and the distance between the fluorescent lamp tube surface and the reflector does not become extremely close, resulting in current leakage and malfunction of one-side lighting. Absent.
  • the invention according to claim 2 of the present invention is based on the premise of the invention according to claim 1, wherein in the reflector, a dimension in a side surface thickness direction of the light guide plate in the opening is wider than a thickness dimension of the light guide plate, It is characterized in that the back side of the reflector partially covers the back side of the reflection sheet.
  • the dimension (opening dimension) of the light guide plate in the side surface thickness direction at the opening of the reflector is wider than the thickness dimension of the light guide plate, and the back side portion of the reflector corresponds to the back side of the reflection sheet.
  • the reflector is partially covered, even if the opening of the reflector is thicker than the light-incident side of the light guide plate, the light enters the light guide plate without leaking to the back side, so that the fluorescent lamp light is transmitted to the light guide plate.
  • the incidence efficiency hardly decreases.
  • the illumination unit according to claim 3 of the present invention is based on the premise of the invention according to claim 1, wherein a dimension in a side surface thickness direction of the light guide plate at the opening of the reflector is the same as a thickness dimension of the light guide plate. It is characterized in that the opening position of the opening of the reflector does not protrude from the position in the thickness direction of the light guide plate.
  • the efficiency of incidence of the light of the fluorescent lamp on the light guide plate can be increased.
  • a lighting unit according to claim 4 of the present invention is characterized in that, on the premise of the invention described in claims 1 to 3, the reflector is formed so as to bulge toward a back surface side. And according to the present invention, since the reflector is formed so as to bulge toward the back surface side, the portion ( ⁇ diameter dimension) surrounding the fluorescent lamp of the reflector can be enlarged in accordance with the bulge. . This makes it possible to increase the diameter of the fluorescent lamp tube without making the distance between the fluorescent lamp tube surface and the reflector extremely close. In addition, since the main surface side shape of the reflector is a flat plate, the user side (main surface) Side), the same appearance as in the prior art can be maintained.
  • a liquid crystal display according to claim 5 of the present invention includes the lighting unit according to any one of claims 1 to 4, and a liquid crystal display panel disposed above the lighting unit. It is characterized by.
  • the tube diameter of the fluorescent lamp can be increased without increasing the thickness of the light guide plate, and the light of the fluorescent lamp can be efficiently incident on the light guide plate. Therefore, it is possible to provide a liquid crystal display device capable of realizing high luminance, long life, and light weight.
  • FIG. 1 is a configuration diagram of the lighting unit according to the embodiment of the present invention.
  • FIG. 2 is a configuration diagram of a lighting unit according to another embodiment of the present invention.
  • FIG. 3 is a configuration diagram of a conventional lighting unit.
  • FIGS. 1 (a) and 1 (b) A lighting unit according to one embodiment of the present invention is shown in FIGS. 1 (a) and 1 (b).
  • This lighting unit UT includes a fluorescent lamp 8, a reflector 7, a housing 3, a light guide plate 1, a reflection sheet 2, and a resin film sheet 5.
  • the liquid crystal display panel 9 is arranged on the main surface side of the lighting unit UT, the rear surface par 6 and the housing 3 are fixed on the rear surface side with screws 4, and the whole is fixed with the metal frame 10. It is.
  • the fluorescent lamp 8 is driven by a high-frequency alternating current (40 to 100 kHz). It is a fluorescent discharge tube that emits light.
  • one lamp (FIG. 1 (a)) and two lamps (FIG.
  • L-shaped fluorescent discharge tubes etc.
  • the reflector 7 efficiently radiates the light of the fluorescent lamp 8 to the incident end face of the light guide plate 1, is bent so as to surround the fluorescent lamp 8, is disposed close to the light guide plate 1, and is made of a resin sheet such as silver or aluminum. It is made by evaporating a material having high reflectance.
  • the reflector 7 is formed in the same manner as the conventional one on the front side and the side, and the back side is formed so as to bulge outward, so that the light guide plate at the opening of the reflector 7 is formed.
  • HI is smaller (shorter and smaller) than H2, the inner diameter of the part surrounding the fluorescent lamp 8 (radial dimension of the fluorescent lamp).
  • the dimension HI in the thickness direction of the side surface of the light guide plate at the opening of the reflector 7 is larger than the thickness dimension H 3 of the light guide plate. Since the shape extends to the back side of 1, the light emitted to the back side does not leak to the outside.
  • the shape of the housing 3 and the metal frame 10 should be changed because the reflector 7 bulges toward the back surface, and the shape of the front surface (main surface) does not change. It is possible to produce the housing 3 and the metal frame 10 economically and without lowering the strength, and it is possible to maintain the same appearance on the user side (main surface side) as before according to the implementation. It is. Further, the conventional housing 3 and metal frame 10 can be used.
  • the light guide plate 1 is formed of a material such as acrylic which has optimal optical characteristics typified by transmittance and refractive index necessary for light transmission.
  • the light guide plate 1 is provided with a dot pattern or a groove pattern (not shown) whose shape is changed in accordance with the distance from the fluorescent lamp 8 on the back surface.
  • the reflection sheet 2 has a role of causing the light traveling outward from the rear surface of the light guide plate 1 to be reflected back into the light guide plate 1 again and returning the illumination light efficiently from the main surface. It is arranged along the surface.
  • a white resin film having a high reflectance is used as the reflection sheet 2. Note that one side of the reflection sheet 2 may be bent so as to surround the fluorescent lamp 8 to form a reflector 7 integrally formed with the reflection sheet 2, and a structure in which the back side is expanded.
  • the housing 3 is arranged close to the side of the reflector 7 so as to surround it from above.
  • the housing 3 serves as a holder for the reflector 7 and also holds the liquid crystal display panel 9 and the light guide plate 1.
  • Examples of the material of the housing 3 include polycarbonate resin.
  • the resin film sheet 5 is arranged on the main surface side (outgoing light side) of the light guide plate 1 and is configured by combining a plurality of diffusion sheets / prism sheets / polarization separation sheets.
  • the back cover 6 serves as a housing, holds the light guide plate 1 and the reflection sheet 2, and protects the reflector 7 from the outer peripheral side, and is made of metal or synthetic resin.
  • One end side 6 a of the back cover 6 extends from the side of the reflector 7 where the fluorescent lamp 8 is arranged to open to the back side of the housing 3. That is, the first step portion 6b and the second step portion 6c are formed so as to slightly swell toward the back side, and the end of the one end side 6a of the back cover 6 is provided with a screw 4 serving as a locking means.
  • the housing 3 is screwed to the back side of the housing 3.
  • the fluorescent lamp 8 is mounted together with the reflector 7, and the back cover 6 is mounted on the housing 3. Secure with 3 screws to 3. In some cases, the reflector 7 and the reflection sheet 2 are directly fixed to the nozzle 3 with screws or the like without using the rear surface force par 6.
  • a liquid crystal display panel 9 is arranged on the irradiation surface side (main surface side), and a metal frame 10 is attached to the liquid crystal display device L.
  • LCD table The display panel 9 displays characters and images.A pair of transparent substrates on which display electrodes are laid face each other at an appropriate interval, a liquid crystal material is injected into the interval, and the periphery of the transparent substrate is sealed. It is composed of a panel sealed with a material, a plurality of driving circuits arranged around the panel and for displaying the panel, and a substrate on which the driving circuit is mounted.
  • the light emitted from the fluorescent lamp 8 is directly or reflected by the reflector 7.
  • the light is condensed and guided to the light guide plate 1, and is evenly transmitted to the entire back surface of the liquid crystal display panel 9, so that the characters and images projected on the display surface of the liquid crystal display panel 9 become visible.
  • the portion (inner diameter) surrounding the fluorescent lamp 8 inside the reflector 7 is wider than before, the tube diameter of the fluorescent lamp 8 can be increased while maintaining a sufficient distance between the fluorescent lamp 8 tube surface and the reflector 7. Can also be made thicker.
  • the back surface side portion of the reflector 7 extends to the back surface side of the light guide plate 1, light emitted from the fluorescent lamp 8 in the back direction does not leak to the outside and is surely incident on the light guide plate 1.
  • two fluorescent lamps 8 can be used as shown in FIG. 1 (b), and three or more fluorescent lamps can be used. Furthermore, in the present embodiment, the fluorescent lamps 8 are arranged on one side of the light guide plate 1, but the present invention is not limited to this, and the fluorescent lamps 8 may be arranged on a plurality of sides. Further, as shown in FIGS. 2 (a) and 2 (b), the same effect can be obtained even if the vertical dimension HI of the opening of the reflector 7 is equal to or smaller than the thickness of the light guide plate 1.
  • the shape of the portion surrounding the fluorescent lamp 8 of the reflector 7 is substantially U-shaped, but the shape is not limited to this, and a method of attaching the lighting unit UT to an electronic device or the like, such as a semicircle or an ellipse,
  • the shape of the reflector 7 and the back cover 6 may be arbitrarily changed according to the mounting shape.
  • the dimension in the thickness direction of the side surface of the light guide plate at the opening of the reflector 7 may be the same as the thickness dimension H 3 of the light guide plate 1. Is small, and if the opening position of the opening of the reflector 7 does not protrude beyond the position in the thickness direction of the light guide plate 1, the light of the fluorescent lamp 8 emitted from the opening of the reflector 7 The light can enter the light guide plate 1 without leaking to the outside.
  • the light guide plate can be designed to be thin without hardly reducing the light entrance efficiency of the lamp light into the light guide plate, so that the light weight can be reduced and the fluorescent lamp can be made thinner than necessary. Since there is no need to do so, it is possible to achieve a desired design with a long life, and since the distance between the fluorescent lamp tube surface and the reflector will not be extremely close, there will be no problem of current leakage and lamp piece lighting.
  • the current leakage is considered to be proportional to the square of the distance between the fluorescent lamp tube surface and the reflector, and the present invention makes it possible to sufficiently maintain the distance between the fluorescent lamp tube surface and the reflector.
  • the efficiency of the light of the fluorescent lamp entering the light guide plate is improved. Can be higher.
  • the main surface side shape of the reflector is a flat plate, and therefore, the user side (the main surface). Side) can maintain the same appearance as before.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Planar Illumination Modules (AREA)
  • Liquid Crystal (AREA)

Abstract

An illumination unit which maintains the incidence efficiency of the light of a fluorescent lamp into an optical guide plate and eliminates unfarablenesses such as pink discharge and lamp one-sided lighting, and elongates lifetime and reduce weight even with a fluorescent lamp with a diameter larger than the thickness of the optical guide plate, and a liquid crystal display device comprising the illumination unit. The illumination unit (UT) comprises a fluorescent lamp (8), an optical guide plate (1) for guiding light from the fluorescent lamp (8), a reflector (7) so arranged as to surround the fluorescent lamp (8) to reflect the light from the fluorescent lamp (8) through an opening toward the optical guide plate (1), and a reflection sheet (2) so arranged on the rear of the guide plate (1) as to reflect the light entering the guide plate (1) upward. The side face thickness directional dimension (H1) of the guide plate in the opening of the reflector (7) is made narrower than the inner-diameter dimension (H2) of the section that surrounds the fluorescent lamp (8).

Description

明 細 書  Specification
照明ュニットとそれを用いた液晶表示装置 技術分野 Lighting unit and liquid crystal display device using it
本発明は、 液晶表示装置の照明用として使用される照明ュニットとそれを用い た液晶表示装置に関する。 背景技術  The present invention relates to an illumination unit used for illumination of a liquid crystal display device and a liquid crystal display device using the same. Background art
従来から、 ラップトップやノートブックタイプのワードプロセッサ、 或いはパ 一ソナルコンピュータなどの情報機器用の表示装置において、 軽量薄型、 低消費 電力などの特徴を活かして透過型の液晶表示パネルに画像を表示する液晶表示装 置が多用されている。 最近では、 液晶表示パネルの表示領域をその裏面から照明 するための照明ュニットを内蔵したものが大半を占めるようになつてきた。 この 照明ユニットは、 ノート p cやモニター、 モパイル P Cなどの普及に伴って光源 を導光板の四周側面の一側面に配するエッジライトタイプが主流となっている。  Conventionally, display devices for information devices such as laptop and notebook type word processors or personal computers display images on transmissive liquid crystal display panels by taking advantage of features such as light weight and thinness and low power consumption. Liquid crystal display devices are frequently used. In recent years, the majority have come with built-in lighting units to illuminate the display area of the LCD panel from the back. With the spread of notebook PCs, monitors, Mopile PCs, etc., this lighting unit is mainly of the edge light type, in which the light source is arranged on one side of the four side surfaces of the light guide plate.
F i g 3に、 従来のエッジライトタイプの照明ュニットの断面図 （蛍光ランプ 配置側） を示す。 このエッジライトタイプの照明ユニットにおいては、 蛍光ラン プ 8からの発光を有効に利用するよう均斉化を施した導光板 1の裏面に、 その導 光板 1の外形と同等の形状の反射シート 2を、 導光板 1の主面に樹脂製フィルム シート 5を設置し、 導光板 1の側面に配置した蛍光ランプ 8をリフレクタ 7で包 み込む構成としており、 以上の部材は樹脂製の外枠であるハゥジング 3に組み込 まれ、 裏面カバー 6とともにネジ 4で係止されている。  Fig. 3 shows a cross-sectional view of a conventional edge light type lighting unit (on the side where fluorescent lamps are arranged). In this edge light type lighting unit, a reflection sheet 2 having the same shape as the outer shape of the light guide plate 1 is provided on the back surface of the light guide plate 1 that has been equalized so as to effectively use the light emitted from the fluorescent lamp 8. In addition, a resin film sheet 5 is installed on the main surface of the light guide plate 1, and the fluorescent lamp 8 arranged on the side surface of the light guide plate 1 is wrapped by the reflector 7, and the above members are resin outer frames. It is incorporated in the housing 3 and is fixed together with the back cover 6 with the screw 4.
リフレクタ 7は、 蛍光ランプ 8の光を導光板 1の入射端面 （側面） に効率よく 光を入射させるもので、 蛍光ランプ 8を囲むように断面が略 U字状に折り曲げら れ、 導光板 1に近接配置されている。 リフレクタ 7は、 樹脂シートに銀やアルミ ニゥムなどの反射率の高い材料を蒸着している。 このような構成の照明ュニットは、 照明ュニット U Tの主面側 ( F i g 3にお いて上方） に液晶表示パネル 9が配され、 金属フレーム 1 0が取り付けられて液 晶表示装置 Lとなる。 金属フレーム 1 0は、 液晶表示パネル 9及びその他の構成 部材を前面 （主面） 側から内包するように保持するフレームである。 蛍光ランプ 8から発光された光は、 直接又はリフレクタ 7により集光されて導光板 1へと導 かれ、 液晶表示パネル 9の背面全体に均等に伝えられることにより、 液晶表示パ ネル 9の表示面に映し出された文字や映像が可視状態となる。 The reflector 7 allows the light of the fluorescent lamp 8 to efficiently enter the incident end face (side surface) of the light guide plate 1. The cross section of the reflector 7 is bent into a substantially U shape so as to surround the fluorescent lamp 8, and the light guide plate 1 It is arranged close to. The reflector 7 is formed by depositing a highly reflective material such as silver or aluminum on a resin sheet. In the lighting unit having such a configuration, a liquid crystal display panel 9 is arranged on the main surface side (upper in FIG. 3) of the lighting unit UT, and a metal frame 10 is attached to form a liquid crystal display device L. The metal frame 10 is a frame that holds the liquid crystal display panel 9 and other components so as to be included from the front (main surface) side. The light emitted from the fluorescent lamp 8 is directly or condensed by the reflector 7, is guided to the light guide plate 1, and is evenly transmitted to the entire rear surface of the liquid crystal display panel 9, thereby displaying the display surface of the liquid crystal display panel 9. The characters and images projected on the screen become visible.
ところが、 C R T代替としての液晶モニターの需要拡大に伴い、 高輝度化、 大 画面化、 蛍光ランプ 8の長寿命化に対する要求が最近益々強くなってきている。 高輝度化に対しては、 ノート P Cやカー A Vなどではプリズムシートなどを用い て高輝度化を達成しているが、 モニターでは高輝度化と共に輝度視野角も同時に 要求されるため、 プリズムシート等は用いることが出来ない。 そこで蛍光ランプ 8を 2〜6本若しくはそれ以上用い、 且つノート P C等より大電流を流すことに より高輝度化を達成している。 し力し、 蛍光ランプ 8に大電流を流し、 なおかつ 長寿命を維持するためには、 ある程度の管径が必要であり、 エッジライト方式で は、 導光板 1の厚さ寸法 H 3は通常、 入射効率を考慮して、 リフレクタ 7の開口 部における導光板 1の側面厚さ方向の寸法 H 1より大きくしなければならないた め、 太径の蛍光ランプ 8が多灯配置されると、 導光板 1の入射面に配置する場合 は、 その分導光板 1の厚さ寸法 H 3を厚くしなければならず、 軽量化及び薄型化 に反することとなっていた。 一方、 軽量化及び薄型化を重視して、 導光板 1の厚 さ寸法 H 3をリフレクタ 7の開口部における導光板 1の厚さ方向の寸法 H Iより 小さく （狭く、 短く） すると、 蛍光ランプ 8の光の導光板 1への入射効率が低下 する問題が生じていた。  However, with the growing demand for LCD monitors as an alternative to CRTs, demands for higher brightness, larger screens, and longer life of fluorescent lamps 8 have recently increased. To increase brightness, notebook PCs and car AV devices use prism sheets to achieve higher brightness, but monitors require higher brightness and viewing angle at the same time. Cannot be used. Therefore, high luminance is achieved by using 2 to 6 or more fluorescent lamps 8 and flowing a larger current than the note PC or the like. In order to allow a large current to flow through the fluorescent lamp 8 and maintain a long life, a certain tube diameter is required. In the edge light method, the thickness H 3 of the light guide plate 1 is usually In consideration of the incident efficiency, the dimension in the thickness direction of the light guide plate 1 at the opening of the reflector 7 must be larger than the dimension H1, so if a large number of large-diameter fluorescent lamps 8 are arranged, the light guide plate In the case where the light guide plate 1 is disposed on the light incident surface, the thickness H3 of the light guide plate 1 must be increased accordingly, which is against weight and thickness reduction. On the other hand, if the thickness H3 of the light guide plate 1 is made smaller (narrower and shorter) than the thickness HI of the light guide plate 1 in the opening of the reflector 7 with a focus on weight reduction and thinning, the fluorescent lamp 8 There has been a problem that the efficiency of incidence of the light on the light guide plate 1 is reduced.
また、 最大限軽量ィ匕と長寿命化を維持するために、 配置した蛍光ランプ 8の管 径をできるだけ太くする設計をするため、 蛍光ランプ 8を覆うリフレクタ 7が蛍 光ランプ 8の管面と近接、 又は部分的に接触する構造を取らざるを得なかった。 しかし、 リフレクタ 7は、 樹脂シートに銀やアルミニウムなどの反射率の高い材 料を蒸着しているために、 蛍光ランプが近接又は接触すると、 蛍光ランプのリー ク電流が増大し、ピンク放電（水銀発光の水銀がなくなるとピンク色に放電する） やランプ片点灯などの不具合 （ランプ寿命の末期状態のような点灯） が起こりや すい設計となっていた。 In addition, in order to keep the fluorescent lamp 8 placed as large as possible in order to maintain the maximum lightweight and long life, the reflector 7 that covers the fluorescent lamp 8 is We had to adopt a structure that was in close or partial contact. However, since the reflector 7 has a highly reflective material such as silver or aluminum deposited on a resin sheet, when a fluorescent lamp approaches or comes into contact with the fluorescent lamp, the leak current of the fluorescent lamp increases and the pink discharge (mercury) It was designed to easily cause problems such as the discharge of pink light when mercury disappears, and the lighting of lamp pieces (lighting at the end of lamp life).
そこで本発明は、 上記問題点を解決するもので、 蛍光ランプの光の導光板への 入射効率を維持しつつ、かつピンク放電ゃランプ片点灯などの不具合をも解消し、 導光板の厚みよりも大きい管径の蛍光ランプを使用しても長寿命化及び軽量化を 図ることができる照明ュニットとそれを用いた液晶表示装置の提供を目的とする。  Therefore, the present invention solves the above problems, while maintaining the efficiency of the light from the fluorescent lamp to enter the light guide plate, and also eliminating the problems such as pink discharge and lamp lighting, and reducing the thickness of the light guide plate. It is an object of the present invention to provide a lighting unit which can achieve a long life and a light weight even when a fluorescent lamp having a large tube diameter is used, and a liquid crystal display device using the same.
発明の開示 Disclosure of the invention
本発明の請求の範囲 1記載の照明ユニットは、 蛍光ランプと、 蛍光ランプから の光を主面に導く導光板と、 蛍光ランプを囲むように配されて導光板の側面に向 けて開口部を有するリフレクタと、 導光板に入射した光を主面へ反射させるよう 導光板の裏面に配した反射シートとを備えた照明ュニットにおいて、 リフレクタ の開口部における導光板の側面厚さ方向の寸法は蛍光ランプを囲む部分の内径寸 法より狭いことを特徴とする。  The lighting unit according to claim 1 of the present invention includes a fluorescent lamp, a light guide plate that guides light from the fluorescent lamp to the main surface, and an opening that is arranged so as to surround the fluorescent lamp and faces a side surface of the light guide plate. In a lighting unit including a reflector having a light guide plate and a reflection sheet disposed on the back surface of the light guide plate so as to reflect light incident on the light guide plate to the main surface, the dimension of the light guide plate in the side surface thickness direction at the opening of the reflector is It is characterized by being smaller than the inner diameter of the part surrounding the fluorescent lamp.
従来形状のリフレクタを用いて径の大きい蛍光ランプを配した場合、 蛍光ラン プの管径に合わせてリフレクタの開口部が大きくなるため、 薄い導光板を用いる と、 蛍光ランプの光が外部にもれて導光板に対する入射効率が低下し、 反対に、 リフレクタの開口部に合わせて導光板の入射側厚みを厚くすると、 照明ュニット 全体が厚く、 重いものとなっていた。 この発明によれば、 リフレクタの開口部に おける導光板の側面厚さ方向の寸法 （開口寸法） は蛍光ランプを囲む部分の内径 寸法より狭く （短く、 小さく） なっているため、 蛍光ランプ光の導光板への入射 効率は殆ど低下することがない。 したがって、 導光板を必要以上に厚くしなくと もよくなり、 これにより、 導光板を所望の厚みに設計できるため、 軽量化ができ る。 また、 蛍光ランプを必要以上に細管化しなくても良いため、 長寿命化設計が 出来、 蛍光ランプ管面とリフレクタの距離も極端に近接する事が無いため、 電流 リークゃ片点灯の不具合も起こらない。 When a fluorescent lamp with a large diameter is arranged using a reflector with a conventional shape, the opening of the reflector becomes large in accordance with the tube diameter of the fluorescent lamp. As a result, the incidence efficiency with respect to the light guide plate is reduced, and conversely, if the thickness of the light guide plate on the incident side is increased in accordance with the opening of the reflector, the entire lighting unit becomes thick and heavy. According to the present invention, the dimension (opening dimension) in the thickness direction of the side surface of the light guide plate at the opening of the reflector is smaller (shorter and smaller) than the inner diameter dimension of the portion surrounding the fluorescent lamp. The incidence efficiency on the light guide plate is hardly reduced. Therefore, it is not necessary to make the light guide plate unnecessarily thick, so that the light guide plate can be designed to have a desired thickness. You. In addition, since the fluorescent lamp does not need to be made thinner than necessary, it is possible to design a longer life, and the distance between the fluorescent lamp tube surface and the reflector does not become extremely close, resulting in current leakage and malfunction of one-side lighting. Absent.
本発明の請求の範囲 2記載の発明は、 請求の範囲 1記載の発明を前提として、 前記リフレクタは、 その開口部における導光板の側面厚さ方向の寸法が導光板の 厚さ寸法より広く、 リフレクタの裏面側部分が反射シートの裏面側を一部覆う形 状であることを特徴とする。  The invention according to claim 2 of the present invention is based on the premise of the invention according to claim 1, wherein in the reflector, a dimension in a side surface thickness direction of the light guide plate in the opening is wider than a thickness dimension of the light guide plate, It is characterized in that the back side of the reflector partially covers the back side of the reflection sheet.
従来のリフレクタにおいて、 リフレクタ開口部における導光板の側面厚さ方向 の寸法が導光板の厚さ寸法より大きくなると、 蛍光ランプの光が外部にもれて導 光板に対する入射効率が悪くなり、 特に裏面側にもれた光は、 何ら輝度に影響せ ず無駄になっていた。 この発明によれば、 リフレクタの開口部における導光板の 側面厚さ方向の寸法 （開口寸法） が導光板の厚さ寸法より広く、 力つ、 リフレタ タの裏面側部分は反射シートの裏面側を一部覆う形状であるため、 リフレクタの 開口部が導光板の入射側厚みより大きかったとしても、 光が裏面側にもれること なく導光板に入射されるため、 蛍光ランプ光の導光板への入射効率は殆ど低下す ることがない。  In conventional reflectors, if the size in the thickness direction of the light guide plate at the reflector opening is larger than the thickness of the light guide plate, the light from the fluorescent lamp will leak to the outside and the efficiency of incidence on the light guide plate will deteriorate, especially on the back surface. Light spilled to the side wasted without any effect on brightness. According to the present invention, the dimension (opening dimension) of the light guide plate in the side surface thickness direction at the opening of the reflector is wider than the thickness dimension of the light guide plate, and the back side portion of the reflector corresponds to the back side of the reflection sheet. Because the reflector is partially covered, even if the opening of the reflector is thicker than the light-incident side of the light guide plate, the light enters the light guide plate without leaking to the back side, so that the fluorescent lamp light is transmitted to the light guide plate. The incidence efficiency hardly decreases.
本発明の請求の範囲 3記載の照明ュニットは、 請求の範囲 1記載の発明を前提 として、 前記リフレクタの開口部における導光板の側面厚さ方向の寸法が、 導光 板の厚さ寸法と同じかもしくは小さく、 リフレクタの開口部の開口位置は導光板 の厚さ方向の位置をはみ出さないことを特徴とする。  The illumination unit according to claim 3 of the present invention is based on the premise of the invention according to claim 1, wherein a dimension in a side surface thickness direction of the light guide plate at the opening of the reflector is the same as a thickness dimension of the light guide plate. It is characterized in that the opening position of the opening of the reflector does not protrude from the position in the thickness direction of the light guide plate.
この発明によれば、 リフレクタの開口部から出射される蛍光ランプの光が外部 に漏れることなく導光板に入射されるため、 蛍光ランプの光の導光板への入射効 率を高くすることができる。  According to the present invention, since the light of the fluorescent lamp emitted from the opening of the reflector is incident on the light guide plate without leaking to the outside, the efficiency of incidence of the light of the fluorescent lamp on the light guide plate can be increased. .
本発明の請求の範囲 4記載の照明ュニットは、 請求の範囲 1乃至請求の範囲 3 記載の発明を前提にして、 前記リフレクタは、 裏面側に向けてふくらむように形 成されていることを特徴とする。 この発明によれば、 リフレクタが裏面側に向けてふくらむように形成されてい ることから、 このふくらみに合わせるようにして、 リフレクタの蛍光ランプを囲 む部分 （內径寸法） を大きくすることができる。 これにより、 蛍光ランプ管面と リフレクタの距離が極端に近接する事なく蛍光ランプの管径を大きくすることが でき、 しかも、 リフレクタの主面側形状は平板であるため、 使用者側 （主面側） においては従来と同様の外観を保つことができる。 A lighting unit according to claim 4 of the present invention is characterized in that, on the premise of the invention described in claims 1 to 3, the reflector is formed so as to bulge toward a back surface side. And According to the present invention, since the reflector is formed so as to bulge toward the back surface side, the portion (內 diameter dimension) surrounding the fluorescent lamp of the reflector can be enlarged in accordance with the bulge. . This makes it possible to increase the diameter of the fluorescent lamp tube without making the distance between the fluorescent lamp tube surface and the reflector extremely close. In addition, since the main surface side shape of the reflector is a flat plate, the user side (main surface) Side), the same appearance as in the prior art can be maintained.
. 本発明の請求の範囲 5記載の液晶表示装置は、 請求の範囲 1乃至請求の範囲 4 のいずれかに記載した照明ュニットと、 この照明ュニットの上方に配される液晶 表示パネルとを備えることを特徴とする。  A liquid crystal display according to claim 5 of the present invention includes the lighting unit according to any one of claims 1 to 4, and a liquid crystal display panel disposed above the lighting unit. It is characterized by.
この発明によれば、照明ュニットのリフレクタの形状を変化させることにより、 導光板を厚くすることなく蛍光ランプの管径を大きくできるとともに、 蛍光ラン プの光を効率良く導光板に入射させることができるため、 高輝度、 長寿命及ぴ軽 量化のいずれも実現できる液晶表示装置を提供することができる。 図面の簡単な説明  According to the present invention, by changing the shape of the reflector of the illumination unit, the tube diameter of the fluorescent lamp can be increased without increasing the thickness of the light guide plate, and the light of the fluorescent lamp can be efficiently incident on the light guide plate. Therefore, it is possible to provide a liquid crystal display device capable of realizing high luminance, long life, and light weight. BRIEF DESCRIPTION OF THE FIGURES
F i g 1は、 本発明の実施の形態における照明ュニットの構成図である。 F i g 2は、 本発明の別の実施の形態における照明ユニットの構成図である。 F i g 3は、 従来の照明ユニットの構成図である。 発明を実施するための最良の形態  FIG. 1 is a configuration diagram of the lighting unit according to the embodiment of the present invention. FIG. 2 is a configuration diagram of a lighting unit according to another embodiment of the present invention. FIG. 3 is a configuration diagram of a conventional lighting unit. BEST MODE FOR CARRYING OUT THE INVENTION
本発明の一実施の形態の照明ュニットを、 F i g 1 ( a ) 及び F i g 1 ( b ) に示す。 この照明ユニット U Tは、 蛍光ランプ 8とリフレクタ 7とハウジング 3 と導光板 1と反射シート 2と樹脂製フィルムシ一ト 5を備える。 液晶表示装置 L は、 照明ユニット U Tの主面側に液晶表示パネル 9を配置し、 裏面側にて裏面力 パー 6とハウジング 3をネジ 4で固定し、 金属フレーム 1 0で全体を固定したも のである。 蛍光ランプ 8は、 高周波の交流 （4 0〜1 0 0 k H z ) で駆動されて 発光する蛍光放電管である。 本実施の形態の蛍光ランプ 8は、 導光板 1の一つの 側面に 1灯 （F i g 1 ( a ) ) 及び 2灯 （F i g 1 ( b ) ) 配されているが、 左右 両側面に 1灯もしくは複数灯配されるものや、 導光板 1の四辺のうち二辺に L字 型に配されるもの （「L字型の蛍光放電管」等と呼ばれる） 等があり、 いずれもェ ッジライト方式と呼ばれる。 A lighting unit according to one embodiment of the present invention is shown in FIGS. 1 (a) and 1 (b). This lighting unit UT includes a fluorescent lamp 8, a reflector 7, a housing 3, a light guide plate 1, a reflection sheet 2, and a resin film sheet 5. In the liquid crystal display device L, the liquid crystal display panel 9 is arranged on the main surface side of the lighting unit UT, the rear surface par 6 and the housing 3 are fixed on the rear surface side with screws 4, and the whole is fixed with the metal frame 10. It is. The fluorescent lamp 8 is driven by a high-frequency alternating current (40 to 100 kHz). It is a fluorescent discharge tube that emits light. In the fluorescent lamp 8 of the present embodiment, one lamp (FIG. 1 (a)) and two lamps (FIG. 1 (b)) are arranged on one side of the light guide plate 1, but one side is provided on each of the left and right sides. There are lamps or multiple lamps, and L-shaped lamps on two of the four sides of the light guide plate 1 (called "L-shaped fluorescent discharge tubes" etc.). Called the scheme.
リフレクタ 7は、 蛍光ランプ 8の光を導光板 1の入射端面に効率よく入射させ るもので、 蛍光ランプ 8を囲むように折り曲げられ、 導光板 1に近接配置され、 樹脂シートに銀やアルミニウムなどの反射率の高い材料を蒸着して作られる。 リ フレクタ 7は、 その表面側部分と側面部分は従来と同様に形成し、 その裏面側部 分を外方向に向けてふくらむように形成することで、 リフレクタ 7の開口部にお ける導光板の側面厚さ方向の寸法 （開口部の内側の上下寸法） H Iは蛍光ランプ 8を囲む部分の内径寸法 （蛍光ランプの径方向の寸法） H 2より狭く （短く、 小 さく） なる。 F i g l ( a ) において、 リフレクタ 7の開口部における導光板の 側面厚さ方向の寸法 H Iは、 導光板の厚さ寸法 H 3より大きくなつているが、 リ フレクタ 7の裏面側部分が導光板 1の裏面側にまで及ぶ形状となっているため、 裏面側に出射された光が外部にもれることはない。  The reflector 7 efficiently radiates the light of the fluorescent lamp 8 to the incident end face of the light guide plate 1, is bent so as to surround the fluorescent lamp 8, is disposed close to the light guide plate 1, and is made of a resin sheet such as silver or aluminum. It is made by evaporating a material having high reflectance. The reflector 7 is formed in the same manner as the conventional one on the front side and the side, and the back side is formed so as to bulge outward, so that the light guide plate at the opening of the reflector 7 is formed. HI is smaller (shorter and smaller) than H2, the inner diameter of the part surrounding the fluorescent lamp 8 (radial dimension of the fluorescent lamp). In F igl (a), the dimension HI in the thickness direction of the side surface of the light guide plate at the opening of the reflector 7 is larger than the thickness dimension H 3 of the light guide plate. Since the shape extends to the back side of 1, the light emitted to the back side does not leak to the outside.
また、 リフレクタ 7は裏面側に向けてふくらみ、 表面 （主面） 側の形状は変化 させず、 従来と同様の凹凸の少ない表面形状であるため、 ハウジング 3及び金属 フレーム 1 0の形状を変えることなく、 かつ、 強度を下げることなく経済的にハ ゥジング 3および金属フレーム 1 0を作成することができ、 使用者側 （主面側） において、 従来と同様の外観を保つことは実施に応じ可能である。 また、 従来の ハウジング 3および金属フレーム 1 0を利用することもできる。  The shape of the housing 3 and the metal frame 10 should be changed because the reflector 7 bulges toward the back surface, and the shape of the front surface (main surface) does not change. It is possible to produce the housing 3 and the metal frame 10 economically and without lowering the strength, and it is possible to maintain the same appearance on the user side (main surface side) as before according to the implementation. It is. Further, the conventional housing 3 and metal frame 10 can be used.
導光板 1は、 光伝達に必要な透過率及び屈折率で代表される光学特性が最適な アクリル等の材料で形成されている。 この導光板 1には、 蛍光ランプ 8からの距 離に応じて形状を変化させたドットパターンあるいは溝パターン （図示せず） 等 が裏面に施されている。 反射シート 2は、 導光板 1の裏面から外方向へ進 光を再度導光板 1の中へ反 射させて戻し、 照明光を効率よく主面から出射させる役割を有し、 導光板 1の裏 面に沿うように配されている。 この反射シート 2は、 高反射率を有する白色の樹 脂製フィルムが使用されている。 なお、 この反射シート 2の一方側を、 蛍光ラン プ 8を囲むように折り曲げて、反射シート 2と一体構成のリフレクタ 7を形成し、 裏面側を膨らませる構造とすることも可能である。 The light guide plate 1 is formed of a material such as acrylic which has optimal optical characteristics typified by transmittance and refractive index necessary for light transmission. The light guide plate 1 is provided with a dot pattern or a groove pattern (not shown) whose shape is changed in accordance with the distance from the fluorescent lamp 8 on the back surface. The reflection sheet 2 has a role of causing the light traveling outward from the rear surface of the light guide plate 1 to be reflected back into the light guide plate 1 again and returning the illumination light efficiently from the main surface. It is arranged along the surface. As the reflection sheet 2, a white resin film having a high reflectance is used. Note that one side of the reflection sheet 2 may be bent so as to surround the fluorescent lamp 8 to form a reflector 7 integrally formed with the reflection sheet 2, and a structure in which the back side is expanded.
ハウジング 3は、 リフレクタ 7の側面と上方から囲むように近接配置されてい る。 ハウジング 3は、 リフレクタ 7のホルダーとしての役割を果たすとともに、 液晶表示パネル 9と導光板 1を保持する役割も有する。 ハウジング 3の材料とし ては、 例えばポリカーボネート樹脂などがある。  The housing 3 is arranged close to the side of the reflector 7 so as to surround it from above. The housing 3 serves as a holder for the reflector 7 and also holds the liquid crystal display panel 9 and the light guide plate 1. Examples of the material of the housing 3 include polycarbonate resin.
樹脂製フィルムシート 5は、 導光板 1の主面側 （出射光側） に配され、 拡散シ 一トゃプリズムシ一トゃ偏光分離シート等を複数枚組み合わせて構成される。 裏面カバー 6は、 筐体としての役割を果たし、 導光板 1や反射シート 2を保持 するとともに、 リフレクタ 7を外周側から保護するもので、 金属製や合成樹脂製 のものがある。 裏面カバー 6の一方端側 6 aは、 リフレクタ 7の蛍光ランプ 8が 配される側からハウジング 3の裏面側に開くように及んでいる。 すなわち、 第 1 の段差部 6 bと第 2の段差部 6 cにより、 裏面側に若干膨らむように形成され、 裏面カバー 6の一方端側 6 aの先端は、 係止手段であるネジ 4を介してハウジン グ 3の裏面側と螺合されている。  The resin film sheet 5 is arranged on the main surface side (outgoing light side) of the light guide plate 1 and is configured by combining a plurality of diffusion sheets / prism sheets / polarization separation sheets. The back cover 6 serves as a housing, holds the light guide plate 1 and the reflection sheet 2, and protects the reflector 7 from the outer peripheral side, and is made of metal or synthetic resin. One end side 6 a of the back cover 6 extends from the side of the reflector 7 where the fluorescent lamp 8 is arranged to open to the back side of the housing 3. That is, the first step portion 6b and the second step portion 6c are formed so as to slightly swell toward the back side, and the end of the one end side 6a of the back cover 6 is provided with a screw 4 serving as a locking means. The housing 3 is screwed to the back side of the housing 3.
本実施の形態の照明ュニット U Tは、ハゥジング 3に反射シート 2、導光板 1、 樹脂製フィルムシート 5が順に挿入された後、 蛍光ランプ 8をリフレクタ 7と共 に装着し、 裏面カバー 6をハウジング 3にネジ 4で固定する。 なお、 リフレクタ 7及び反射シート 2は、 裏面力パー 6を用いずに直接ノヽウジング 3にネジ等で固 定する場合もある。  In the lighting unit UT of the present embodiment, after the reflection sheet 2, the light guide plate 1, and the resin film sheet 5 are inserted into the housing 3 in order, the fluorescent lamp 8 is mounted together with the reflector 7, and the back cover 6 is mounted on the housing 3. Secure with 3 screws to 3. In some cases, the reflector 7 and the reflection sheet 2 are directly fixed to the nozzle 3 with screws or the like without using the rear surface force par 6.
このような照明ユニット U Tは、 その照射面側 （主面側） に液晶表示パネル 9 が配され、 金属フレーム 1 0が取り付けられて、 液晶表示装置 Lとなる。 液晶表 示パネル 9は、 文字および映像を表示するもので、 表示用電極が敷設された一対 の透明基板を適宜な間隔で対峙させ、 その間隔に液晶材料を注入し、 前記透明基 板の周辺をシール材で封止して構成されるパネルと、 このパネルの周囲に配置さ れ、 パネルを表示させるための複数の駆動用回路と、 この駆動用回路を実装した 基板などから構成される。 In such a lighting unit UT, a liquid crystal display panel 9 is arranged on the irradiation surface side (main surface side), and a metal frame 10 is attached to the liquid crystal display device L. LCD table The display panel 9 displays characters and images.A pair of transparent substrates on which display electrodes are laid face each other at an appropriate interval, a liquid crystal material is injected into the interval, and the periphery of the transparent substrate is sealed. It is composed of a panel sealed with a material, a plurality of driving circuits arranged around the panel and for displaying the panel, and a substrate on which the driving circuit is mounted.
この照明ユニット UTの主面側 （F i g l (a), (b) において上方） に液晶 表示パネル 9が搭載された液晶表示装置 Lにおいて、 蛍光ランプ 8から発光され た光は、 直接又はリフレクタ 7により集光されて導光板 1へと導かれ、 液晶表示 パネル 9の背面全体に均等に伝えられることにより、 液晶表示パネル 9の表示面 に映し出された文字や映像が可視状態となる。 このとき、 リフレクタ 7内部の蛍 光ランプ 8を囲む部分 （内径寸法） は従来よりも広いため、 蛍光ランプ 8管面と リフレクタ 7の距離を十分保ったまま、 蛍光ランプ 8の管径を従来よりも太くす ることができる。 また、 リフレクタ 7の裏面側部分は導光板 1の裏面側まで及ぶ ため、 蛍光ランプ 8から裏面方向に出射された光は外部にもれることなく、 確実 に導光板 1に入射される。  In the liquid crystal display device L in which the liquid crystal display panel 9 is mounted on the main surface side of the lighting unit UT (upper in Fig. (A) and (b)), the light emitted from the fluorescent lamp 8 is directly or reflected by the reflector 7. The light is condensed and guided to the light guide plate 1, and is evenly transmitted to the entire back surface of the liquid crystal display panel 9, so that the characters and images projected on the display surface of the liquid crystal display panel 9 become visible. At this time, since the portion (inner diameter) surrounding the fluorescent lamp 8 inside the reflector 7 is wider than before, the tube diameter of the fluorescent lamp 8 can be increased while maintaining a sufficient distance between the fluorescent lamp 8 tube surface and the reflector 7. Can also be made thicker. In addition, since the back surface side portion of the reflector 7 extends to the back surface side of the light guide plate 1, light emitted from the fluorescent lamp 8 in the back direction does not leak to the outside and is surely incident on the light guide plate 1.
また、 本実施の形態は、 F i g l (b) に示すように蛍光ランプ 8を 2本使用 することも可能であり、 3本以上とすることもできる。 さらに、 本実施の形態に おいては蛍光ランプ 8を導光板 1の一辺に配置したが、 これに限らず、 複数辺に 蛍光ランプ 8を配置した構成としてもよい。 また、 F i g 2 (a)、 (b) に示す ように、 リフレクタ 7の開口部の上下寸法 HIを導光板 1の厚みと同じかもしく は小さくしても、 同様の効果が得られる。 本実施の形態においては、 リフレクタ 7の蛍光ランプ 8を囲む部分の形状は略 U字状であるが、 これに限らず、 半円や 楕円等、 照明ュニット UTの電子機器等への取り付け方法や取り付け形状に合わ せて、 リフレクタ 7及び裏面カバー 6の形状を任意に変化させてもよい。  In the present embodiment, two fluorescent lamps 8 can be used as shown in FIG. 1 (b), and three or more fluorescent lamps can be used. Furthermore, in the present embodiment, the fluorescent lamps 8 are arranged on one side of the light guide plate 1, but the present invention is not limited to this, and the fluorescent lamps 8 may be arranged on a plurality of sides. Further, as shown in FIGS. 2 (a) and 2 (b), the same effect can be obtained even if the vertical dimension HI of the opening of the reflector 7 is equal to or smaller than the thickness of the light guide plate 1. In the present embodiment, the shape of the portion surrounding the fluorescent lamp 8 of the reflector 7 is substantially U-shaped, but the shape is not limited to this, and a method of attaching the lighting unit UT to an electronic device or the like, such as a semicircle or an ellipse, The shape of the reflector 7 and the back cover 6 may be arbitrarily changed according to the mounting shape.
また、 F i g 2に示すように、 リフレクタ 7の開口部における導光板の側面厚 さ方向の寸法 （開口寸法） HI力 導光板 1の厚さ寸法 H 3と同じ寸法かもしく は小さな寸法で、 かつ、 リフレクタ 7の開口部の開口位置が導光板 1の厚さ方向 の位置をはみ出さない形状とした場合は、 リフレクタ 7の開口部から出射される 蛍光ランプ 8の光が外部に漏れることなく導光板 1に入射させることが可能とな る。 産業上の利用可能性 In addition, as shown in FIG. 2, the dimension in the thickness direction of the side surface of the light guide plate at the opening of the reflector 7 (opening dimension) may be the same as the thickness dimension H 3 of the light guide plate 1. Is small, and if the opening position of the opening of the reflector 7 does not protrude beyond the position in the thickness direction of the light guide plate 1, the light of the fluorescent lamp 8 emitted from the opening of the reflector 7 The light can enter the light guide plate 1 without leaking to the outside. Industrial applicability
以上説明したように、 本発明によれば、 ランプ光の導光板への入光効率を殆ど 低下させることなく導光板を薄く設計できるため、 軽量ィヒが出来、 蛍光ランプを 必要以上に細管化しなくても良いため、 所望の長寿命化設計が出来、 蛍光ランプ 管面とリフレクタの距離も極端に近接する事が無いため、 電流リークゃランプ片 点灯の不具合も起こらない。 電流リークは蛍光ランプ管面とリフレクタの距離の 二乗に比例すると考えられ、 本発明により蛍光ランプ管面とリフレクタの距離を 十分保てるようになるため、 電流リークやランプ片点灯の不具合も起こらない。 また、 請求の範囲 3記載の発明によれば、 リフレクタ開口部から出射される蛍 光ランプの光が外部に漏れることなく導光板に入射されるため、 蛍光ランプの光 の導光板への入射効率が高くできる。 また、 請求の範囲 4記載の発明によれば、 リフレクタが裏面側に向けてふくらむように形成されていることから、 リフレタ タの主面側形状は平板上であるため、 使用者側 （主面側） においては従来と同様 の外観を保つことができる。  As described above, according to the present invention, the light guide plate can be designed to be thin without hardly reducing the light entrance efficiency of the lamp light into the light guide plate, so that the light weight can be reduced and the fluorescent lamp can be made thinner than necessary. Since there is no need to do so, it is possible to achieve a desired design with a long life, and since the distance between the fluorescent lamp tube surface and the reflector will not be extremely close, there will be no problem of current leakage and lamp piece lighting. The current leakage is considered to be proportional to the square of the distance between the fluorescent lamp tube surface and the reflector, and the present invention makes it possible to sufficiently maintain the distance between the fluorescent lamp tube surface and the reflector. According to the third aspect of the invention, since the light of the fluorescent lamp emitted from the reflector opening is incident on the light guide plate without leaking to the outside, the efficiency of the light of the fluorescent lamp entering the light guide plate is improved. Can be higher. Further, according to the invention described in claim 4, since the reflector is formed so as to bulge toward the back surface side, the main surface side shape of the reflector is a flat plate, and therefore, the user side (the main surface). Side) can maintain the same appearance as before.

Claims

請 求 の 範 囲 The scope of the claims
1 . 蛍光ランプと、 蛍光ランプからの光を主面に導く導光板と、 蛍光ランプを囲 むように配されて導光板の側面に向けて開口部を有するリフレクタと、 導光板に 入射した光を主面へ反射させるよう導光板の裏面に配した反射シートとを備えた 照明ユニットにおいて、 リフレクタの開口部における導光板の側面厚さ方向の寸 法は蛍光ランプを囲む部分の内径寸法より狭いことを特徴とする照明ュニット。 1. A fluorescent lamp, a light guide plate for guiding light from the fluorescent lamp to the main surface, a reflector arranged to surround the fluorescent lamp and having an opening toward a side surface of the light guide plate, and a light guide for light incident on the light guide plate. In a lighting unit provided with a reflection sheet disposed on the back surface of the light guide plate so as to reflect light to the surface, the dimension in the thickness direction of the side surface of the light guide plate at the opening of the reflector is smaller than the inner diameter of the portion surrounding the fluorescent lamp. Lighting unit featuring.
2 . 前記リフレクタは、 その開口部における導光板の側面厚さ方向の寸法が導光 板の厚さ寸法より広く、 リフレクタの裏面側部分が反射シートの裏面側を一部覆 う形状であることを特徴とする請求の範囲 1記載の照明ュニット。 2. The reflector has a shape in which the side surface thickness direction of the light guide plate at the opening is wider than the thickness size of the light guide plate, and the back side of the reflector partially covers the back side of the reflection sheet. The lighting unit according to claim 1, wherein the lighting unit is characterized in that:
3 . 前記リフレクタの開口部における導光板の側面厚さ方向の寸法が、 導光板の 厚さ寸法と同じかもしくは小さく、 リフレクタの開口部の開口位置は導光板の厚 さ方向の位置をはみ出さないことを特徴とする請求の範囲 1記載の照明ュニット。 3. The dimension in the thickness direction of the light guide plate at the opening of the reflector is equal to or smaller than the thickness dimension of the light guide plate, and the opening position of the opening of the reflector protrudes beyond the position in the thickness direction of the light guide plate. The lighting unit according to claim 1, wherein the lighting unit is not provided.
4 . 前記リフレクタは、 裏面側に向けてふくらむように形成されていることを特 徴とする請求の範囲 1乃至請求の範囲 3記載の照明ュニット。 4. The lighting unit according to claim 1, wherein the reflector is formed so as to bulge toward a back surface.
5 . 請求の範囲 1乃至請求の範囲 4のいずれかに記載した照明ュニットと、 この 照明ュ-ットの照射面側に配される液晶表示パネルとを備えることを特徴とする 5. The lighting unit according to any one of claims 1 to 4, and a liquid crystal display panel arranged on an irradiation surface side of the lighting unit.
PCT/JP2002/009575 2001-09-18 2002-09-18 Illumination unit and liquid crystal display apparatus comprising it WO2003025457A1 (en)

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JP2015103349A (en) * 2013-11-22 2015-06-04 株式会社エダキン Luminaire

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JPH04114129A (en) * 1990-09-04 1992-04-15 Seiko Epson Corp Back light system of liquid crystal display device
JPH08146232A (en) * 1994-03-23 1996-06-07 Tosoh Corp Backlight
JPH08278415A (en) * 1995-04-07 1996-10-22 Taiho Ind Co Ltd Backlight for liquid crystal panel and reflecting sheet
JPH0982123A (en) * 1995-09-11 1997-03-28 Hitachi Ltd Liquid crystal display device
JP2000305083A (en) * 1999-04-21 2000-11-02 Mitsubishi Electric Corp Backlight for liquid crystal display device

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JPH04114129A (en) * 1990-09-04 1992-04-15 Seiko Epson Corp Back light system of liquid crystal display device
JPH08146232A (en) * 1994-03-23 1996-06-07 Tosoh Corp Backlight
JPH08278415A (en) * 1995-04-07 1996-10-22 Taiho Ind Co Ltd Backlight for liquid crystal panel and reflecting sheet
JPH0982123A (en) * 1995-09-11 1997-03-28 Hitachi Ltd Liquid crystal display device
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