JP2013012445A

Movatterモバイル変換

Info

Publication number: JP2013012445A
Application number: JP2011145892A
Authority: JP
Inventors: Takao Ono; 恭男大野; Masahisa Nishio; 昌久西尾
Original assignee: Minebea Co Ltd
Current assignee: Minebea Co Ltd
Priority date: 2011-06-30
Filing date: 2011-06-30
Publication date: 2013-01-17

Abstract

PROBLEM TO BE SOLVED: To achieve coexistence of securing heat radiation of an LED and reducing cost in a planar lighting device.SOLUTION: In a substrate 14 with an LED 12 mounted, a mounting surface with the LED 12 mounted is fixed to a support member 16 so as to face that 16, and heat generated from the LED 12 is transmitted to the support member 16. The heat transmitted from the LED 12 to the support member 16, moreover, is transmitted to a case 20 through a base part 16a, and is emitted from a surface of the case 20 to the outside. Since the mounting surface of the substrate 14 is fixed to the support member 16 intervened between a side end surface of the light guide plate 18 and the substrate 14, the LED 12 mounted on the mounting surface of the substrate 14 is positioned to be faced to a side end surface of the light guide plate 18. Furthermore, since the base part 16a of the support member 16 is loaded in free sliding along a floor surface of a floor part 20a of the case 20, even if heat generated from the LED 12 is applied and expansion and contraction on the light guide plate 18 facing to the LED 12 or the like is generated, dimensional change of these is absorbed.

Description

Translated fromJapanese

本発明は、面状照明装置に関するものである。 The present invention relates to a planar illumination device.

近年の青色発光ダイオード（ＬＥＤ）の高性能化に伴い、ＬＥＤを光源に用いた面状照明装置が広く用いられるようになっている。面状照明装置は、発光面を構成する導光板と、導光板の側端面に対向して配置されるＬＥＤと、ＬＥＤが実装される回路基板とで構成される、サイドライト型と呼ばれる面状照明装置が一般的である。 With the recent improvement in performance of blue light-emitting diodes (LEDs), planar lighting devices using LEDs as light sources have been widely used. A planar lighting device is a planar shape called a sidelight type, which is composed of a light guide plate that constitutes a light emitting surface, LEDs that are disposed to face side end surfaces of the light guide plate, and a circuit board on which the LEDs are mounted. A lighting device is common.

図４には、従来の、面状照明装置をバックライトとして備える液晶表示装置１００の構造が概略的に示されている。この液晶表示装置１００は、導光板１０２と、導光板の側端面に対向して配置される点状光源としてのＬＥＤ１０４と、導光板１０２の側端面に対向して配置されＬＥＤ１０４が実装される基板１０６と、導光板１０２の表面（光出射面）に配置されるＬＣＤ１０８と、導光板１０２の裏面に配置される反射シート１１０と、これらの各構成要素を収納するケース１１２とで構成されている。FIG. 4 schematically shows a structure of a conventional liquidcrystal display device 100 including a planar illumination device as a backlight. The liquidcrystal display device 100 includes alight guide plate 102, anLED 104 serving as a point light source disposed to face the side end surface of the light guide plate, and a substrate on which theLED 104 is mounted facing the side end surface of thelight guide plate 102. 106, anLCD 108 disposed on the front surface (light emitting surface) of thelight guide plate 102, areflective sheet 110 disposed on the back surface of thelight guide plate 102, and acase 112 that houses these components. .

図４の例では、基板１０６は金属基板であり、ケース１１２も銅、アルミニウム等で構成されていることから、ＬＥＤ１０４から発生する熱は、基板１０６からケース１１２へと伝わり、ケース１１２の表面から外部へと放出されるものである。このように、ＬＥＤ１０４の放熱経路が確保されることで、ＬＥＤ１０４の温度上昇による発光効率の低下を防ぐことが可能となる（特許文献１参照）。 In the example of FIG. 4, thesubstrate 106 is a metal substrate, and thecase 112 is also made of copper, aluminum, or the like. Therefore, heat generated from theLED 104 is transferred from thesubstrate 106 to thecase 112, and from the surface of thecase 112. It is released to the outside. Thus, by ensuring the heat dissipation path of theLED 104, it is possible to prevent a decrease in light emission efficiency due to a temperature rise of the LED 104 (see Patent Document 1).

実用新案登録第３０９８４６３号公報Utility Model Registration No. 3098463

しかしながら、従来の面状照明装置において、ＬＥＤからの発熱を逃がすための放熱経路を構成するべく採用された金属基板は、ＰＣＢ、ＦＰＣ等の一般的なプリント基板に比べて高コストとなることが指摘されている（特開２００８−１８６７８０号公報の段落０００７参照）。
本発明は、上記のような問題に鑑みなされたものであり、その目的とするところは、面状照明装置において、ＬＥＤの放熱性の確保とコストの低減との両立を図ることにある。However, in a conventional planar lighting device, a metal substrate adopted to constitute a heat dissipation path for releasing heat from the LED may be more expensive than a general printed circuit board such as PCB or FPC. It has been pointed out (see paragraph 0007 of JP 2008-186780 A).
This invention is made | formed in view of the above problems, and the place made into the objective is to aim at coexistence with ensuring of the heat dissipation of LED, and reduction of cost in a planar illuminating device.

（発明の態様）
以下の発明の態様は、本発明の構成を例示するものであり、本発明の多様な構成の理解を容易にするために、項別けして説明するものである。各項は、本発明の技術的範囲を限定するものではなく、発明を実施するための最良の形態を参酌しつつ、各項の構成要素の一部を置換し、削除し、又は、更に他の構成要素を付加したものについても、本願発明の技術的範囲に含まれ得るものである。(Aspect of the Invention)
The following aspects of the present invention exemplify the configuration of the present invention, and will be described separately for easy understanding of various configurations of the present invention. Each section does not limit the technical scope of the present invention, and some of the components of each section are replaced, deleted, or further while referring to the best mode for carrying out the invention. Those to which the above components are added can also be included in the technical scope of the present invention.

（１）導光板と、該導光板の側端面に対向して配置される点状光源と、該導光板の側端面に対向して配置され前記点状光源が実装される基板と、該基板を保持する熱伝導部材と、これらの各構成要素を収納するケースとを備え、前記熱伝導部材は前記ケースとの接触部を具備して、前記導光板の側端面と前記基板との間に介在しており、前記基板の前記点状光源が実装される実装面が、前記熱伝導部材と対向するようにして前記熱伝導部材に固定されている面状照明装置（請求項１）。(1) A light guide plate, a point light source disposed to face the side end surface of the light guide plate, a substrate disposed to face the side end surface of the light guide plate and mounted with the point light source, and the substrate A heat conductive member that holds the components, and a case that houses each of these components, the heat conductive member having a contact portion with the case, and between the side end surface of the light guide plate and the substrate. A planar illumination device that is interposed and fixed to the heat conducting member such that a mounting surface of the substrate on which the point light source is mounted faces the heat conducting member (Claim 1).

本項に記載の面状照明装置は、基板の点状光源が実装される実装面が、熱伝導部材と対向するようにして熱伝導部材に固定されていることにより、点状光源からの発熱は、効率的に熱伝導部材へと伝わる。熱伝導部材は、ケースとの接触部を具備していることから、点状光源から熱伝導部材に伝わった熱は、更に、接触部を介してケースへと伝わり、ケースの表面から外部へと放出される。なお、基板の実装面が、導光板の側端面と基板との間に介在する熱伝導部材に固定されることで、基板の実装面に実装される点状光源は、導光板の側端面に対向するようにして、位置決めされることとなる。In the planar illumination device described in this section, the mounting surface on which the point light source of the substrate is mounted is fixed to the heat conduction member so as to face the heat conduction member, so that heat is generated from the point light source. Is efficiently transmitted to the heat conducting member. Since the heat conducting member has a contact portion with the case, the heat transferred from the point light source to the heat conducting member is further transferred to the case through the contact portion, and from the surface of the case to the outside. Released. The point light source mounted on the mounting surface of the substrate is fixed to the side end surface of the light guide plate by fixing the mounting surface of the substrate to the heat conducting member interposed between the side end surface of the light guide plate and the substrate. Positioning is performed so as to face each other.

（２）上記（１）項において、前記熱伝導部材の接触部は、少なくとも前記基板の長手方向の全体に渡る長さを有している面状照明装置。
本項に記載の面状照明装置は、熱伝導部材の接触部は、少なくとも基板の長手方向の全体に渡る長さを有していることで、ケースに対する前記熱伝導部材の接触面積を十分に確保するものである。そして、熱伝導部材からケースへの熱伝導効率を高めるものである。(2) In the above item (1), the contact portion of the heat conducting member is a planar lighting device having a length over at least the entire length of the substrate.
In the planar lighting device described in this section, the contact portion of the heat conductive member has a length extending at least over the entire length of the substrate, so that the contact area of the heat conductive member with respect to the case is sufficiently large. It is to secure. And the heat-conduction efficiency from a heat conductive member to a case is improved.

（３）上記（１）（２）項において、前記ケースは、床部と該床部の端部から起立する壁部とを有し、前記熱伝導部材の接触部は、前記ケースの床部の床面に沿って摺動可能に載置され、前記熱伝導部材と前記ケースの壁部との間に、弾性部材が配置されている面状照明装置（請求項２）。
本項に記載の面状照明装置は、熱伝導部材の接触部が、ケースの床部の床面に沿って摺動可能に載置されていることにより、点状光源からの発熱を受けて、点状光源と対向する導光板やケース等に伸縮が生じても、その寸法変化を、熱伝導部材がケースに対して移動することで吸収するものである。又、熱伝導部材とケースの壁部との間に配置された、弾性部材の弾性力によって、上記寸法変化の有無に関わらず、点状光源と導光板との適切な位置関係を保持するものである。(3) In the above items (1) and (2), the case includes a floor portion and a wall portion standing from an end portion of the floor portion, and the contact portion of the heat conducting member is a floor portion of the case. A planar lighting device that is slidably mounted along the floor surface and in which an elastic member is disposed between the heat conducting member and the wall portion of the case (Claim 2).
In the planar lighting device described in this section, the contact portion of the heat conducting member is slidably placed along the floor surface of the floor portion of the case, thereby receiving heat from the point light source. Even if the light guide plate or the case facing the point light source expands or contracts, the dimensional change is absorbed by the heat conduction member moving with respect to the case. In addition, the elastic member disposed between the heat conducting member and the case wall retains an appropriate positional relationship between the point light source and the light guide plate regardless of the above-described dimensional change. It is.

（４）上記（１）から（３）項において、前記熱伝導部材は、前記接触部を構成する基部と、該基部から起立する基板保持部を備え、該基板保持部に前記基板が固定されている面状照明装置（請求項３）。
本項に記載の面状照明装置は、熱伝導部材の基部から起立する基板保持部の、導光板との対向面とは反対側の面に、基板が固定されることで、基板の実装面に実装される点状光源は、導光板の側端面に対向して配置されることとなる。そして、基板保持部に固定された基板に実装された点状光源からの発熱は、熱伝導部材の基板保持部から基部へと伝わり、更に、基部からケースの床部へと伝わるものである。(4) In the above items (1) to (3), the heat conducting member includes a base portion constituting the contact portion and a substrate holding portion standing up from the base portion, and the substrate is fixed to the substrate holding portion. A planar lighting device (Claim 3).
The planar lighting device described in this section is configured so that the substrate is fixed to the surface of the substrate holding unit that stands up from the base of the heat conducting member, on the side opposite to the surface facing the light guide plate. The point light source mounted on is disposed to face the side end face of the light guide plate. Then, heat generated from the point light source mounted on the substrate fixed to the substrate holding portion is transmitted from the substrate holding portion of the heat conducting member to the base portion, and further from the base portion to the floor portion of the case.

（５）上記（４）項において、前記基板保持部に、前記点状光源を貫通させる開口部が形成されている面状照明装置（請求項４）。
本項に記載の面状照明装置は、熱伝導部材の基板保持部に形成されている開口部を介して、基板の実装面に実装される点状光源が、導光板の側端面に対面するものである。この開口部は、点状光源の外形に倣った形状の開口が基板保持部に形成されたものであっても良く、又、基板保持部の端辺に一部が開放する切り欠きであっても良い。いずれにせよ、基板保持部は、開口部を設けることにより、基板保持部に点状光源の貫通路を確保した上で、点状光源の周囲の少なくとも二辺を取囲むように基板の実装面との接触面を形成することで、基板の実装面との必要な接触面積を確保するものである。(5) The planar illumination device according to (4), wherein an opening for penetrating the point light source is formed in the substrate holding part.
In the surface illumination device described in this section, the point light source mounted on the mounting surface of the substrate faces the side end surface of the light guide plate through the opening formed in the substrate holding portion of the heat conducting member. Is. The opening may be an opening having a shape following the outer shape of the point light source formed in the substrate holding portion, and is a notch that is partially opened at the edge of the substrate holding portion. Also good. In any case, the substrate holding portion is provided with an opening so that a through-hole for the point light source is secured in the substrate holding portion, and at least two sides around the point light source are surrounded. By forming the contact surface, the necessary contact area with the mounting surface of the substrate is ensured.

（６）上記（１）から（５）項において、前記熱伝導部材は、金属製である面状照明装置（請求項５）。
本項に記載の面状照明装置は、熱伝導部材が金属製であることにより、必要な熱伝導率を確保するものである。
（７）上記（１）から（６）項において、前記基板の導体パターンの幅は、前記点状光源の幅以上に形成されている面状照明装置（請求項６）。
本項に記載の面状照明装置は、基板の導体パターンを介して点状光源からの発熱を熱伝導部材へと伝える際に、基板の熱伝導に大きく寄与する領域（導体パターン）を広くすることで、基板から熱伝導部材への放熱経路を広げるものである。(6) In the above items (1) to (5), the heat conduction member is a planar illumination device made of metal (claim 5).
The planar illuminating device described in this section secures necessary heat conductivity because the heat conducting member is made of metal.
(7) The planar illumination device according to (1) to (6) above, wherein the width of the conductor pattern of the substrate is greater than the width of the point light source.
The planar illumination device described in this section widens a region (conductor pattern) that greatly contributes to the heat conduction of the substrate when the heat from the point light source is transmitted to the heat conducting member through the conductor pattern of the substrate. This widens the heat dissipation path from the substrate to the heat conducting member.

本発明はこのように構成したので、面状照明装置において、ＬＥＤの放熱性の確保とコストの低減との両立を図ることが可能となる。 Since this invention was comprised in this way, it becomes possible to aim at coexistence with ensuring of the heat dissipation of LED, and cost reduction in a planar illuminating device.

本発明に係る面状照明装置を示す模式図であり、（ａ）は外観図、（ｂ）は内部構造を示す部分拡大図、（ｃ）は（ｂ）のＡ部拡大図である。It is a schematic diagram which shows the planar illuminating device which concerns on this invention, (a) is an external view, (b) is the elements on larger scale which show an internal structure, (c) is the A section enlarged view of (b).本発明の実施の形態に係る面状照明装置の構造を示す要部断面図である。It is principal part sectional drawing which shows the structure of the planar illuminating device which concerns on embodiment of this invention.本発明の実施の形態に係る面状照明装置の基板及びＬＥＤを示す平面図である。It is a top view which shows the board | substrate and LED of the planar illuminating device which concerns on embodiment of this invention.従来の、面状照明装置をバックライトとして備える液晶表示装置を概略的に示した断面図である。It is sectional drawing which showed schematically the conventional liquid crystal display device provided with a planar illuminating device as a backlight.

以下、本発明の実施の形態を図面に基づき説明する。
図１、図２に示されるように、本発明の実施の形態に係る面状照明装置１０は、点状光源としてのＬＥＤ１２と、ＬＥＤ１２が実装される基板１４と、基板１４を保持する支持部材１６と、ＬＥＤ１２を側端面（入光面）に配置し、入光面から入光した光を主平面（出射面）から出射させる導光板１８と、支持部材１６（ＬＥＤ１２）および導光板１８を収納するケース２０と、基板１４の実装面側とは反対側に配置されるクッション（弾性部材）２２と、ケース２０と対をなし、導光板１８の出射面の外周部分を覆うカバー２４とを備えている。Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, theplanar illumination device 10 according to the embodiment of the present invention includes anLED 12 as a point light source, asubstrate 14 on which theLED 12 is mounted, and a support member that holds thesubstrate 14. 16 and theLED 12 are arranged on the side end surface (light incident surface), thelight guide plate 18 that emits the light incident from the light incident surface from the main plane (output surface), and the support member 16 (LED 12) and the light guide plate 18 Acase 20 to be stored, a cushion (elastic member) 22 disposed on the side opposite to the mounting surface side of thesubstrate 14, and acover 24 that forms a pair with thecase 20 and covers the outer peripheral portion of the light exit surface of thelight guide plate 18. I have.

ＬＥＤ１２は、本実施の形態では、いわゆる擬似白色ＬＥＤが用いられている。又、ＬＥＤ１２を実装する基板１４は、本実施の形態では、安価なＰＣＢを短冊状に形成したものであり、導光板１８の入光面に沿って配置されている。又、基板１４の実装面には、図３に示されるように、銅箔パターン２６がＬＥＤ１２の幅以上に形成され、それによって、可能な限り広い面積が確保されるように考慮されている。図３の例では、ランドおよび隣接するランドを結ぶ配線の幅を広く形成した銅箔パターン２６が採用されている。なお、銅箔パターン２６と支持部材１６の間の少なくとも一部に、カバーレイ２８を介在させることにより、必要な絶縁性を確保している。 In the present embodiment, a so-called pseudo white LED is used as theLED 12. In the present embodiment, thesubstrate 14 on which theLEDs 12 are mounted is formed by forming an inexpensive PCB in a strip shape, and is disposed along the light incident surface of thelight guide plate 18. Further, as shown in FIG. 3, acopper foil pattern 26 is formed on the mounting surface of thesubstrate 14 so as to be larger than the width of theLED 12, so that as much area as possible is secured. In the example of FIG. 3, acopper foil pattern 26 in which the width of the wiring connecting the land and the adjacent land is wide is adopted. In addition, necessary insulation is ensured by interposing a cover lay 28 at least partly between thecopper foil pattern 26 and thesupport member 16.

支持部材１６は、金属材料、好ましくは、伝熱性に優れ安価なアルミニウムが用いられることで、熱伝導部材を構成するものである。図示の例では、アルミ板を断面Ｌ字状に成形することで、ケース２０と直接的に接触する接触部を構成する基部１６ａと、基部１６ａに直交するようにして基部１６ａから起立する基板保持部１６ｂとを有している。又、図示の例では、基部１６ａ及び基板保持部１６ｂは、少なくとも基板の長手方向の全体に渡る長さを有している。又、基板保持部１６ｂには、各ＬＥＤ１２に対応した位置に貫通させる開口部１６ｃが形成されている。図示の例では、開口部１６ｃはＬＥＤ１２の外形に倣った矩形状の開口であるが、基板保持部１６ｂの端辺に一部が開放する切り欠きであっても良い。そして、基板保持部１６ｂの外側の面、すなわち、導光板１８との対向面とは反対側の面に対して、基板１４の実装面が対向するようにして、基板１４は熱伝導性両面テープ（図示省略）を用いて固定されている。又、基板保持部１６ｂの外側の面に基板１４が固定された状態で、ＬＥＤ１２は開口部１６ｃを貫通し、ＬＥＤ１２の発光面が基板保持部１６ｂの内側の面、すなわち、導光板１８との対向面から導光板１８側に幾分突き出るように、基板保持部１６ｂの肉厚が設定されている。従って、図２の例では、開口部１６ｃを貫通したＬＥＤ１２は、導光板１８の側端面に当接している。
更に、支持部材１６は、基部１６ａから切り起こされ、基部１６ａと平行な面を構成する台座部１６ｄ（支持部材１６の台座１６ｄ）を備えている。そして、支持部材１６の台座部１６ｄに、導光板１８が載置されるものである。Thesupport member 16 constitutes a heat conduction member by using a metal material, preferably aluminum having excellent heat conductivity and low cost. In the example shown in the figure, an aluminum plate is formed in an L-shaped cross section, so that abase portion 16a that constitutes a contact portion that directly contacts thecase 20 and a substrate that stands up from thebase portion 16a so as to be orthogonal to thebase portion 16a.Part 16b. In the illustrated example, thebase portion 16a and thesubstrate holding portion 16b have a length that extends at least over the entire length of the substrate. Further, thesubstrate holding portion 16b is formed with anopening portion 16c that penetrates to a position corresponding to eachLED 12. In the illustrated example, theopening 16c is a rectangular opening that follows the outer shape of theLED 12, but may be a notch that is partially open at the end of thesubstrate holding portion 16b. Then, thesubstrate 14 is thermally conductive double-sided tape so that the mounting surface of thesubstrate 14 faces the outer surface of thesubstrate holding portion 16b, that is, the surface opposite to the surface facing thelight guide plate 18. (Not shown). Further, in a state where thesubstrate 14 is fixed to the outer surface of thesubstrate holding portion 16b, theLED 12 passes through theopening 16c, and the light emitting surface of theLED 12 is connected to the inner surface of thesubstrate holding portion 16b, that is, thelight guide plate 18. The thickness of thesubstrate holding portion 16b is set so as to protrude somewhat toward thelight guide plate 18 from the facing surface. Therefore, in the example of FIG. 2, theLED 12 that has penetrated theopening 16 c is in contact with the side end surface of thelight guide plate 18.
Further, thesupport member 16 includes apedestal portion 16d (apedestal 16d of the support member 16) that is cut and raised from thebase portion 16a and forms a surface parallel to thebase portion 16a. Thelight guide plate 18 is placed on thepedestal 16d of thesupport member 16.

導光板１８は透明樹脂材料を成形してなる板状の導光体であり、矩形平板状に形成されている。そして、入光面から入射した光を出射面から面状に出射させるために、出射面と対向する面（支持部材１６の台座部１６ｄ側の面）には、例えばドット状の光路変更手段が形成されている。導光板１８の好適な透明樹脂材料には、メタクリル樹脂、ポリカーボネート樹脂、ポリスチレン樹脂、ポレオレフィン樹脂、非晶性ポリオレフィン樹脂、ポリエステル樹脂、ポリスチレン樹脂、透明フッ素樹脂、エポキシ樹脂等が含まれる。 Thelight guide plate 18 is a plate-shaped light guide formed by molding a transparent resin material, and is formed in a rectangular flat plate shape. Then, in order to emit light incident from the light incident surface in a planar shape from the output surface, for example, a dot-shaped optical path changing unit is provided on the surface facing the output surface (the surface on thepedestal portion 16d side of the support member 16). Is formed. Suitable transparent resin materials for thelight guide plate 18 include methacrylic resin, polycarbonate resin, polystyrene resin, polyolefin resin, amorphous polyolefin resin, polyester resin, polystyrene resin, transparent fluororesin, epoxy resin, and the like.

ケース２０は、金属材料（例えば、ステンレス）を用いて全体として無蓋箱状に形成された板金部品であり、低コストに製造することが可能である。このケース２０は、床部２０ａと、床部の外周側から起立する壁部２０ｂを有している。床部２０ａには、支持部材１６の基部１６ａが（固定されずに）載置されている。従って、支持部材１６は、ケース２０の床部２０ａの床面に沿った所定幅の範囲が、摺動可能に配置されたものである。又、ケース２０の床部２０ａの中央部に開口２０ｃが形成され、かつ、開口２０ｃに沿って切り起こされることで、床部２０ａ（基部１６ｄ）と平行な面を構成する台座部２０ｄ（ケース２０の台座部２０ｄ）が形成されている。ケース２０の台座部２０ｄは、支持部材１６の台座部１６ｄと同様に、導光板１８が載置されるものであるが、その位置が固定されている点が、支持部材１６の台座部１６ｄと相違する。なお、ケース２０の開口２０ｃは、ケース２０の軽量化を主目的として形成されたものであり、それに起因するケース２０の強度低下を、台座部２０によって補うことも可能となる。
なお、支持部材１６の台座部１６ｄ、及び、ケース２０の台座部２０ｄは、導光板１８の入光面とＬＥＤ１２の発光面とが対向するように、それらの高さが調整されている。Thecase 20 is a sheet metal part that is formed into a coverless box shape as a whole using a metal material (for example, stainless steel), and can be manufactured at low cost. Thecase 20 includes afloor portion 20a and awall portion 20b that rises from the outer peripheral side of the floor portion. Thebase portion 16a of thesupport member 16 is placed (not fixed) on thefloor portion 20a. Therefore, thesupport member 16 is slidably disposed within a predetermined width range along the floor surface of thefloor portion 20a of thecase 20. Further, anopening 20c is formed at the center of thefloor 20a of thecase 20 and is cut and raised along theopening 20c, thereby forming apedestal 20d (case) that forms a plane parallel to thefloor 20a (base 16d). 20pedestals 20d) are formed. Thepedestal portion 20d of thecase 20 is the same as thepedestal portion 16d of thesupport member 16 on which thelight guide plate 18 is placed. The position of thepedestal portion 20d is fixed with respect to thepedestal portion 16d of thesupport member 16. Is different. Theopening 20c of thecase 20 is formed mainly for the purpose of reducing the weight of thecase 20, and thepedestal 20 can compensate for the strength reduction of thecase 20 caused by the opening.
Note that the height of thepedestal 16d of thesupport member 16 and thepedestal 20d of thecase 20 is adjusted so that the light incident surface of thelight guide plate 18 and the light emitting surface of theLED 12 face each other.

クッション２２は、図示の例では、直方体状に形成されたゴム等の弾性部材が、ケース２０の壁部２０ｂと基板１４との間に配置されたものであるが、ケース２０の壁部２０ｂから基板１４の方向へと向かう弾性力を付与するものであれば、ばねその他の機械的構造を有するものであっても良い。 In the illustrated example, thecushion 22 is an elastic member such as rubber formed in a rectangular parallelepiped shape and disposed between thewall portion 20b of thecase 20 and thesubstrate 14, but from thewall portion 20b of thecase 20 As long as it provides an elastic force toward thesubstrate 14, it may have a spring or other mechanical structure.

カバー２４は、金属材料（例えば、ステンレス）を用いて全体として無蓋箱状に形成された板金部材であり、低コストで製造することが可能である。そして、ケース２０と組み合わさることで、上記各構成要素を収納するように、ケース２０の各壁部２０ｂ（一般的には４辺）にそれぞれ対向する壁部２４ａと、各壁部２４ａの一端（図示上端）から内側に張り出し、全体として枠状に形成された庇部２４ｂを有している。又、庇部２４ｂに囲まれ、導光板１８の出射面よりも一回り小さい大きさの開口部２４ｃを有している。そして、この開口部２４ｃから外部に照明光が出射するように構成されている。また、カバー２４の庇部２４ｂとケース２０の床部２０ａとにより、支持部材１６および導光板１８の厚み方向（図示上下方向）の移動が規制される。
なお、カバー２４の壁部２４ａは、ケース２０の壁部２０ｂの外周面をそれぞれ覆うように配置され、カバー２４の壁部２４ａとケース２０の壁部２０ｂとは、例えば、ねじ等によって互いに固定されるものである。Thecover 24 is a sheet metal member that is formed into a coverless box shape as a whole using a metal material (for example, stainless steel), and can be manufactured at low cost. And by combining with thecase 20, thewall part 24a which each faces eachwall part 20b (generally 4 sides) of thecase 20 so that each said component may be accommodated, and one end of eachwall part 24a It protrudes inward from (the upper end in the figure) and has acollar portion 24b formed in a frame shape as a whole. Moreover, it is surrounded by theflange 24 b and has anopening 24 c that is slightly smaller than the exit surface of thelight guide plate 18. And it is comprised so that illumination light may radiate | emit outside from thisopening part 24c. Further, the movement of thesupport member 16 and thelight guide plate 18 in the thickness direction (vertical direction in the drawing) is restricted by theflange portion 24b of thecover 24 and thefloor portion 20a of thecase 20.
Thewall portion 24a of thecover 24 is disposed so as to cover the outer peripheral surface of thewall portion 20b of thecase 20, and thewall portion 24a of thecover 24 and thewall portion 20b of thecase 20 are fixed to each other by, for example, screws. It is what is done.

更に、本実施の形態では、導光板１８の裏面（出射面と反対側の面）側に反射シート３０が配置され、導光板１８の出射面側に拡散シート３２が配置されている。
又、本実施の形態は、導光板１８の４つの側面に複数のＬＥＤ１２がそれぞれ配置（４辺配置）され、いずれの側面においても上記の構成が採用されているが、本発明は、かかる４辺配置に限定されるものでなく、例えば、１辺配置（１つの側面に配置）を採用する場合にも適用可能なものである。Further, in the present embodiment, thereflection sheet 30 is disposed on the back surface (surface opposite to the exit surface) of thelight guide plate 18, and thediffusion sheet 32 is disposed on the exit surface side of thelight guide plate 18.
In the present embodiment, a plurality ofLEDs 12 are arranged on each of the four side surfaces of the light guide plate 18 (four sides are arranged), and the above-described configuration is adopted on any of the side surfaces. The present invention is not limited to the side arrangement, and can also be applied to a case where, for example, one side arrangement (arranged on one side surface) is adopted.

さて、上記構成をなす、本発明の実施の形態によれば、次のような作用効果を得ることが可能となる。まず、本発明の実施の形態に係る面状照明装置１０は、基板１４のＬＥＤ１２が実装される実装面が、熱伝導部材を構成する支持部材１６と対向するようにして、支持部材１６に固定されていることにより、ＬＥＤ１２からの発熱は、支持部材１６に伝わる。熱伝導部材である支持部材１６は、ケース２０との接触部である基部１６ａを具備していることから、ＬＥＤ１２から支持部材１６に伝わった熱は、更に、基部１６ａを介してケース２０へと伝わり、ケース２０の表面から外部へと放出される。しかも、基板１４の実装面が、導光板１８の側端面と基板１４との間に介在する支持部材１６に固定されることで、基板１４の実装面に実装されるＬＥＤ１２は、導光板１８の側端面に対向するようにして、位置決めされることとなる。Now, according to the embodiment of the present invention configured as described above, the following operational effects can be obtained. First, theplanar lighting device 10 according to the embodiment of the present invention is fixed to thesupport member 16 so that the mounting surface on which theLED 12 of thesubstrate 14 is mounted faces thesupport member 16 constituting the heat conducting member. As a result, heat generated from theLED 12 is transmitted to thesupport member 16. Since thesupport member 16 that is a heat conducting member includes abase portion 16a that is a contact portion with thecase 20, the heat transferred from theLED 12 to thesupport member 16 is further transferred to thecase 20 via thebase portion 16a. It is transmitted to the outside from the surface of thecase 20. In addition, the mounting surface of thesubstrate 14 is fixed to thesupport member 16 interposed between the side end surface of thelight guide plate 18 and thesubstrate 14, so that theLEDs 12 mounted on the mounting surface of thesubstrate 14 are connected to thelight guide plate 18. Positioning is performed so as to face the side end face.

又、支持部材１６の基部１６ａ及び基板保持部１６ｂは、少なくとも基板１４の長手方向の全体に渡る長さを有していることで、基板１４及びケース２０に対する支持部材１６の接触面積を十分に確保し、支持部材１６からケース２０への熱伝導効率を高めることができる。
又、支持部材１６の基部１６ａが、ケース２０の床部２０ａの床面に沿って摺動可能に載置されていることにより、ＬＥＤ１２からの発熱を受けて、ＬＥＤ１２と対向する導光板１８や、ケース２０等に伸縮が生じても、それらの寸法変化を、支持部材１６がケース２０に対して移動することで吸収することができる。又、支持部材１６とケース２０の壁部２０ｂとの間に配置された、弾性部材２２の弾性力によって、上記寸法変化の有無に関わらず、ＬＥＤ１２と導光板１８との適切な位置関係を保持し、面状照明装置１０の照度を安定させることが可能となる。Further, thebase portion 16a and thesubstrate holding portion 16b of thesupport member 16 have at least the entire length in the longitudinal direction of thesubstrate 14, so that the contact area of thesupport member 16 with respect to thesubstrate 14 and thecase 20 is sufficiently large. The heat conduction efficiency from thesupport member 16 to thecase 20 can be increased.
Further, since thebase portion 16a of thesupport member 16 is slidably mounted along the floor surface of thefloor portion 20a of thecase 20, thelight guide plate 18 that receives heat generated from theLED 12 and faces theLED 12 Even if expansion or contraction occurs in thecase 20 or the like, those dimensional changes can be absorbed by thesupport member 16 moving relative to thecase 20. In addition, the appropriate positional relationship between theLED 12 and thelight guide plate 18 is maintained by the elastic force of theelastic member 22 disposed between thesupport member 16 and thewall portion 20b of thecase 20 regardless of the above-described dimensional change. In addition, the illuminance of theplanar illumination device 10 can be stabilized.

又、支持部材１６の基部１６ａから起立する基板保持部１６ｂの、導光板１８との対向面とは反対側の面に、基板１４が固定されることで、基板１４の実装面に実装されるＬＥＤは、導光板１８の側端面に対向して配置されることとなる。そして、基板保持部１６ｂに固定された基板１４に実装されたＬＥＤ１２からの発熱は、支持部材１６の基板保持部１６ｂから基部１６ａへと伝わり、更に、基部１６ａからケース２０の床部２０ａへと伝わり、必要な放熱効果が得られるものである。 In addition, thesubstrate 14 is fixed to the surface of thesubstrate holding portion 16b erected from thebase portion 16a of thesupport member 16 on the side opposite to the surface facing thelight guide plate 18, so that thesubstrate 14 is mounted on the mounting surface of thesubstrate 14. The LED is disposed to face the side end surface of thelight guide plate 18. Then, the heat generated from theLED 12 mounted on thesubstrate 14 fixed to thesubstrate holding portion 16b is transmitted from thesubstrate holding portion 16b of thesupport member 16 to thebase portion 16a, and further from thebase portion 16a to thefloor portion 20a of thecase 20. The necessary heat dissipation effect is obtained.

更に、支持部材１６の基板保持部１６ｂに形成されている開口部１６ｃを介して、基板１４の実装面に実装される点状光源１２は、導光板１８の側端面に対面することとなる。そして、この開口部１６ｃにより、基板保持部１６ｂにＬＥＤ１２の貫通路を確保した上で、ＬＥＤ１２の周囲の少なくとも二辺を取囲むように基板１４の実装面との接触面を形成することで、基板１４の実装面との必要な接触面積を確保することができる。 Furthermore, the pointlight source 12 mounted on the mounting surface of thesubstrate 14 faces the side end surface of thelight guide plate 18 through theopening 16 c formed in thesubstrate holding portion 16 b of thesupport member 16. And by ensuring the penetration path of LED12 insubstrate holding part 16b by thisopening part 16c, by forming a contact surface with the mounting surface ofsubstrate 14 so that at least two sides around LED12 may be surrounded, A necessary contact area with the mounting surface of thesubstrate 14 can be ensured.

又、支持部材１６が金属製であることにより、熱伝導部材として必要な熱伝導率を確保することができる。
加えて、基板１４の導体パターンを介してＬＥＤ１２からの発熱を支持部材１６へと伝える際に、基板１４の熱伝導に大きく寄与する領域（導体パターン）を広くすることで、基板１４から支持部材１６への放熱経路を広げることが可能となる。Further, since thesupport member 16 is made of metal, it is possible to ensure the thermal conductivity necessary for the heat conductive member.
In addition, when the heat generated from theLED 12 is transmitted to thesupport member 16 through the conductor pattern of thesubstrate 14, a region (conductor pattern) that greatly contributes to the heat conduction of thesubstrate 14 is widened, so that the support member from thesubstrate 14 is increased. The heat dissipation path to 16 can be expanded.

以上の如く、本発明の実施の形態によれば、基板１４の実装面に、熱伝導性に優れた金属材料からなる支持部材１６の基板保持部１６ｂを接触させることで、ＬＥＤ１２が放出した熱を、支持部材１６の基板保持部１６ｂに効率的に伝えるものである。そして、基板保持部１６ｂに伝わった熱は、支持部材１６の基部１６ａとケース２０の床部２０ａとが比較的広い面積で接触していることにより、基部１６ａを介してケース２０に効率的に伝えることが可能となっている。このため、従来の如く、高価な金属基板を使用することなく、安価なＰＣＢを用いることで、ＬＥＤ１２の温度上昇を抑制することができ、安価で照度の大きい照明装置１０を実現することが可能となるものである。 As described above, according to the embodiment of the present invention, thesubstrate holding portion 16b of thesupport member 16 made of a metal material having excellent thermal conductivity is brought into contact with the mounting surface of thesubstrate 14 to thereby release the heat released from theLED 12. Is efficiently transmitted to thesubstrate holding portion 16b of thesupport member 16. The heat transmitted to thesubstrate holding portion 16b is efficiently applied to thecase 20 via thebase portion 16a because thebase portion 16a of thesupport member 16 and thefloor portion 20a of thecase 20 are in contact with each other over a relatively wide area. It is possible to communicate. For this reason, it is possible to suppress an increase in the temperature of theLED 12 by using an inexpensive PCB without using an expensive metal substrate as in the prior art, and it is possible to realize aninexpensive lighting device 10 with high illuminance. It will be.

１０：面状照明装置、１２：ＬＥＤ、１４：基板、１６：支持部材、１６ａ：基部、１６ｂ：基板保持部、１６ｃ：開口部、１６ｄ：台座部、１８：導光板、２０：ケース、２０ａ：床部、２０ｂ：壁部、２０ｄ：台座部、２２：クッション（弾性部材）、２６：銅箔パターン10: planar illumination device, 12: LED, 14: substrate, 16: support member, 16a: base, 16b: substrate holding portion, 16c: opening, 16d: pedestal, 18: light guide plate, 20: case, 20a : Floor part, 20b: wall part, 20d: pedestal part, 22: cushion (elastic member), 26: copper foil pattern

Claims

Translated fromJapanese

導光板と、該導光板の側端面に対向して配置される点状光源と、該導光板の側端面に対向して配置され前記点状光源が実装される基板と、該基板を保持する熱伝導部材と、これらの各構成要素を収納するケースとを備え、
前記熱伝導部材は前記ケースとの接触部を具備して、前記導光板の側端面と前記基板との間に介在しており、前記基板の前記点状光源が実装される実装面が、前記熱伝導部材と対向するようにして前記熱伝導部材に固定されていることを特徴とする面状照明装置。A light guide plate, a point light source disposed opposite to the side end surface of the light guide plate, a substrate disposed opposite to the side end surface of the light guide plate and mounted with the point light source, and holding the substrate A heat conducting member and a case for housing each of these components;
The heat conducting member includes a contact portion with the case, and is interposed between a side end surface of the light guide plate and the substrate, and a mounting surface on which the point light source of the substrate is mounted is A planar lighting device, wherein the planar lighting device is fixed to the heat conducting member so as to face the heat conducting member.

前記ケースは、床部と該床部の端部から起立する壁部とを有し、前記熱伝導部材の接触部は、前記ケースの床部の床面に沿って摺動可能に載置され、前記熱伝導部材と前記ケースの壁部との間に、弾性部材が配置されていることを特徴とする請求項１記載の面状照明装置。The case includes a floor portion and a wall portion standing from an end portion of the floor portion, and the contact portion of the heat conducting member is slidably mounted along the floor surface of the floor portion of the case. The planar illumination device according to claim 1, wherein an elastic member is disposed between the heat conducting member and the wall portion of the case.

前記熱伝導部材は、前記接触部を構成する基部と、該基部から起立する基板保持部を備え、該基板保持部に前記基板が固定されていることを特徴とする請求項１又は２記載の面状照明装置。The said heat conductive member is provided with the base part which comprises the said contact part, and the board | substrate holding part which stands up from this base part, The said board | substrate is being fixed to this board | substrate holding part, The Claim 1 or 2 characterized by the above-mentioned. Planar lighting device.

前記基板保持部に、前記点状光源を貫通させる開口部が形成されていることを特徴とする請求項３記載の面状照明装置。The planar illumination device according to claim 3, wherein an opening for penetrating the point light source is formed in the substrate holding part.

前記熱伝導部材は、金属製であることを特徴とする請求項１から４のいずれか１項記載の面状照明装置。The planar lighting device according to claim 1, wherein the heat conducting member is made of metal.

前記基板の導体パターンの幅は、前記点状光源の幅以上に形成されていることを特徴とする請求項１から５のいずれか１項記載の面状照明装置。The planar illumination device according to any one of claims 1 to 5, wherein a width of the conductor pattern of the substrate is formed to be equal to or greater than a width of the point light source.