JP4808860B2

JP4808860B2 - Plasma display device

Info

Publication number: JP4808860B2
Application number: JP2001141541A
Authority: JP
Inventors: 康夫横田; 裕人井ノ上
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2001-05-11
Filing date: 2001-05-11
Publication date: 2011-11-02
Anticipated expiration: 2021-05-11
Also published as: JP2002341777A

Description

【０００１】
【発明の属する技術分野】
本発明はプラズマ表示装置における表示パネルと表示駆動回路の組立構造の改良に関するものである。
【０００２】
【従来の技術】
プラズマ表示装置（以下、ＰＤＰと略称する）は、筐体を含めた奥行が従来のブラウン管を用いた表示装置に比べて小さく、大画面化が容易であるとともに、輝度やコントラストの点で優れている。奥行が小さいことから壁掛けディスプレイとしてショールームなどの公衆表示装置や、企業でのプレゼンテーションに用いる表示装置として有望視されている。また量産により安価になれば家庭用の省スペース型ＴＶ用として普及すると思われる。ＰＤＰは発光原理にプラズマ放電を用いているので、ブラウン管や液晶表示装置に比べ、プラズマ表示パネル（以下、単にパネルという）および駆動回路が大量の熱を発生し筐体内の温度が上昇する。このため熱を筐体の外へ放出し、パネルの温度及び駆動回路の温度上昇を抑えないとパネルの表示特性が劣化したり回路基板に取り付けられた部品の寿命が短くなるおそれがある。またパネル面内に大きな温度差があるとパネルのガラスが破損することがある。ＰＤＰは、表示輝度の向上や、ＢＳチューナの内蔵等で消費電力がますます多くなる傾向にある。消費電力の増大により発熱も多くなるので、放熱が益々重要となってくる。
【０００３】
図１０は従来のＰＤＰの筐体５０の断面図である。図１０を用いて従来のＰＤＰの筐体５０の構造を説明する。筐体５０は前カバー１０とバックカバー７を有する。前カバー１０にＰＤＰのパネル１が取り付けられている。パネルの背面に密着して熱伝導性の良い熱伝導性ゴムシート２が貼り付けられている。熱伝導ゴムシート２に密着してアルミニウムの板で作ったパネル支持部材３が貼り付けられている。一般にパネル支持部材３は高い熱伝導率を有する、例えばアルミニウム材からなり、パネルの熱を熱拡散させ、筐体内の空気に放散させる役割をもつ。パネル支持部材３には例えば２枚の上部回路基板４Ａ、下部回路基板４Ｂが取り付けられている。上部回路基板４Ａ、下部回路基板４Ｂには発熱部品５を含む多くの部品が取り付けられている。パネル１から発生する熱は熱伝導ゴムシート２を経てパネル支持部材３に伝わり、パネル支持部材３の表面から空気中に放出される。パネル支持部材３はパネル１を保持してパネルの変形を防止する補強材として働く。上部回路基板４Ａ及び下部回路基板４Ｂは取付部材のポスト４５によりパネル支持部材３に所定の間隔を保って取り付けられている。バックカバー７の下部には複数の通気孔６が設けられている。筐体５０の上部には、ファン１６が設けられている。ファン１６を動作させると、通気孔６から流入した空気が矢印９に示す経路を通って流れ、ファン１６によって外部に排出される。通気孔６から流入して内部を流れる空気流により、パネル支持部材３および発熱部品５は冷却される。
【０００４】
従来例にはファン１６を備えておらず上部に排気孔のみをもつ自然空冷方式の筐体もある。このような筐体では、発熱部品５から発する熱により空気が温められると、空気の密度が小さくなり上昇気流が発生する。この上昇気流により内部の空気は上部の排気孔から排出され、冷気が下部の通気孔６より流入する。このような筐体内の上昇気流の発生は「煙突効果」といわれている。ＰＤＰは奥行きが小さく、通常パネルを垂直に立てて使用することから、このような上昇気流が筐体内に発生する。
【０００５】
【発明が解決しようとする課題】
図１０に示すファン１６を用いたＰＤＰでは、風速数m/sの空気流を発生させることが可能なため冷却効果は自然空冷の場合よりもかなり高くなる。しかしファン１６が騒音源となり、適切な騒音対策を施さないと製品の品質を著しく低下させることになる。自然空冷では騒音は発生しない。しかし空気の流れを空気の密度変化による上昇気流に依存していることから風速が最大でも0.5m/s前後と小さく、冷却効果に限界があった。
【０００６】
さらに、上記の従来の放熱方法では、ファンの有無に関わらず、通気孔６から流入した空気はパネル支持部材３の下部や下部回路基板４Ｂ上の発熱部品５の部分を通るとき温められ、上部にいく程空気温度は上昇する。そのため冷却効果に差が生じ、パネル１の上部の温度が下部の温度より高くなる。図１１は従来の自然空冷式のパネル１の表面の温度分布を示す正面図である。図１１において、図の上下方向はパネル１の上下方向に対応している。図１１に示すように、パネル１の上部の温度は７５℃から８５℃、下部の温度は６５℃から７０℃であり、上下で１０℃から１５℃の差がある。これは、パネル１の発熱量は全面でほぼ均一であっても、下部で発生した熱が上昇し、上部の冷却効果を妨げるためである。図１２は、図１０のＰＤＰの正面図であり、筐体５０内の下部に配置された下部回路基板４Ｂと上部に配置された上部回路基板４Ａの近傍を流れる空気の温度を測定した結果である。図１２に示すように、筐体５０の下部の気温は４２℃であり、中央部の気温は５６℃、上部の気温は６８℃であった。上部と下部の温度差は約２４℃であり、パネルの上部の冷却効果が低いことがわかる。
【０００７】
このような問題を解決するために、従来のファンを有しないものでは、電気回路の消費電力を小さくする工夫をしたり、筐体５０の上部には大きな発熱のある部品を配置しないようにしていた。しかしＰＤＰに内蔵する各種回路の増加により、高密度かつ大型の回路基板を組込まざるを得なくなり、回路基板の配置が制約をうけるようになってきた。すなわち筐体５０の上部にも発熱部品５を有する上部回路基板４Ａを配置せざるを得ない。その結果、上部回路基板４Ａだけでなくパネル１の上部の温度も高くなり、パネル１の面内の温度差も拡大してパネル１が割れたり発熱部品５の温度上昇による劣化や発火等の問題が生じてくる。
本発明は、筐体の上部に発熱の多い回路基板を設けてもパネルの温度および回路部品の温度の上昇を抑制できるＰＤＰを提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明のプラズマ表示装置は、プラズマ表示パネルを取り付けた平板状のパネル支持部材、前記パネル支持部材に略平行に取り付けられ、前記パネル支持部材との間の間隔が互いに異なる複数の上部及び下部の発熱部品を有する回路基板、及び前記パネル支持部材及び回路基板を収納し、前記回路基板下方に通気孔を有し、上方に排気孔を有する筐体を有することを特徴とする。
本発明によれば、複数の回路基板のそれぞれとパネル支持部材との間の間隔が異なるので、下部の通気孔から流入し、筐体内を上方に向かって流れる空気は、各回路基板毎に分かれた経路を通る。従って、下部の回路基板の発熱部品を含む領域を通過して温められた空気が上部の回路基板上の発熱部品には当たらない。上部の回路基板には、通気孔から流入した外気温と実質的に同じ温度の空気が当たる。従って従来のように上昇気流の温度上昇により上部の回路基板の放熱が妨げられることなく下部の回路基板と同等の冷却効果が得られる。
【０００９】
前記複数の回路基板の内、筐体内の上部に配置した上部回路基板とパネル支持部材との間の間隔を下部に配置した下部回路基板とパネル支持部材との間の間隔より広くし、前記通気孔から流入して下部に配置した下部回路基板を含む領域を通過した空気は、上部に配置した上部回路基板とパネル支持部材との間を通過して排気孔から流出するように構成したことを特徴とする。
下部回路基板から離れた経路を通る温められていない空気が上部基板近傍を通るので上部基板の冷却効果が高い。
【００１０】
前記複数の回路基板の内、筐体内の上部に配置した上部回路基板とパネル支持部材との間の間隔を下部に配置した下部回路基板とパネル支持部材との間の間隔より狭くし、前記通気孔から流入してパネル支持部材と下部に配置した下部回路基板との間を通る空気が上部に配置した上部回路基板を含む領域を通過して排気孔から流出するように構成したことを特徴とする。
下部回路基板近傍を通過して温められた空気は上部回路基板近傍を通らず、パネル支持部材と下部回路基板の間を通る温められていない空気が上部基板近傍を通るので、上部回路基板の冷却効果が高い。
【００１１】
前記パネル支持部材との間の間隔が互いに異なる複数の上部と下部の回路基板の間に設けられ、前記通気孔から流入した空気を前記複数の上部と下部の回路基板毎に分割した経路を通るように分流させる板状部材を更に有する。
上部及び下部回路基板のそれぞれの経路が板状部材で分離されているので、上部及び下部回路基板とも外気とほぼ同じ温度の空気流を受けて冷やされる。従って両回路基板の冷却効果に差がなくなる。
前記板状部材は金属板であり、上部回路基板の熱が前記板状部材に伝わるように、前記上部回路基板に取り付けたことを特徴とする。
金属の板状部材を上部回路基板に取りつけるので、上部回路基板の熱は板状部材に伝わる。従って上部回路基板の冷却効果が更に高くなる。
【００１２】
前記筐体が樹脂製であり所定部分の内側に金属板を設け、前記金属板と上部回路基板の発熱部品との間を熱伝導性部材で接続したことを特徴とする。
筐体が樹脂製で熱伝導性が悪くても、内側の金属板から、発熱部品の熱が放散されるので上部回路基板の放熱効果は高い。
前記金属板を設けた筐体の所定部分に放熱孔を設けたことを特徴とする。
筐体の放熱孔の部分では金属板が外気に触れるので、金属板に取り付けられた上部回路基板の冷却効果が高い。
前記パネル支持部材の上部領域背面に放熱部材を設けたことを特徴とする。
パネル支持部材の熱が放熱部材で放熱されるので、パネルの冷却効果が高い。
【００１３】
【発明の実施の形態】
本発明のプラス表示装置（ＰＤＰ）の好適な実施例を図１から図９を参照して説明する。各断面図において、ＰＤＰの奥行きに対応する左右方向の寸法は、理解を容易にするために拡大されている。
【００１４】
《第１実施例》
本発明の第１実施例を図１及び図２を参照して説明する。図１は、本発明の第１実施例のＰＤＰの斜視図であり、図２は図１のＩＩ−ＩＩ断面図である。図１及び図２において、ＰＤＰのパネル１の背面には熱伝導性のよい熱伝導ゴムシート２が貼り付けられている。熱伝導ゴムシート２はシリコンとゴムの複合材であり、一般に市販されている。熱伝導ゴムシート２には、例えばアルミニウム板で作ったパネル支持部材３が貼り付けられている。これらの構成は図１１に示す従来のものと同じである。筐体５１は前カバー３０とバックカバー３７を有し、前カバー３０には開口部３０Ａが形成されている。筐体５１は金属又はプラスチックで作られている。開口部３０Ａにパネル１が取り付けられている。筐体５１は図において下部に通気孔３１を有し、上部に排気孔３２を有する。筐体５１の内部には、パネル１を制御する発熱部品５を含む電子回路を取り付けた例えば２つの上部回路基板４Ａと下部回路基板４Ｂが設けられている。上部回路基板４Ａは４本の取付ポスト３４によりパネル支持部材３に取り付けられている。下部回路基板４Ｂは、取付ポスト３４より短い４本の取付ポスト３５によりパネル支持部材３に取り付けられている。取付ポスト３４と３５のそれぞれの長さを変えることにより、パネル支持部材３と、上部回路基板４Ａ及び下部回路基板４Ｂとのそれぞれの間隔を変えることができる。例えば、上部回路基板４Ａをパネル支持部材３から約４０ｍｍ離し、下部回路基板４Ｂはパネル支持部材３から約１０ｍｍ離す。
【００１５】
上部回路基板４Ａと下部回路基板４Ｂをこのように配置することにより、通気孔３１の開口部分３１Ｂから流入し、下部回路基板４Ｂ上の発熱部品５の近傍を通過する空気は矢印３９Ｂで示す経路を経て排気孔３２から流出する。一方通気孔３１の、下部回路基板４Ｂから離れた開口部分３１Ａから流入した空気は、下部回路基板４Ｂと後カバー３７との間の空間を矢印３９Ａに示す経路で通過し、上部回路基板４Ａ上に搭載された発熱部品５の近傍を通って排気孔３２から流出する。開口部分３１Ｂから流入した空気は下部回路基板４Ｂの近傍を通過するとき回路基板上の発熱部品５を冷却する。これにより温められた空気は上部回路基板４Ａとパネル支持部材３の間を通って外部へ流出する。従って上部回路基板４Ａ上の発熱部品５は温められた空気にほとんど触れない。一方開口部分３１Ａから流入した外気は下部回路基板４Ｂから離れた経路３９Ａを通る。従って温度が上昇することはなく外気温とほぼ同じ温度のまま上部回路基板４Ａの近傍を通る。これにより、上部回路基板４Ａ上の発熱部品５は外気温とほぼ同じ温度の空気により冷却される。
本実施例のＰＤＰと、図１０に示す従来のＰＤＰのファン１６を取外したものとを、周囲温度等の条件を全く同じにして動作させ各部の温度を測定した。従来構造でファンを取り外した時のＰＤＰのパネル１の最も温度の高い部分の温度（パネル最高温度）は８８℃であったが、本実施例のＰＤＰのパネル最高温度は８４℃であり、４℃低下した。また上部回路基板４Ａ上の特定の発熱部品の温度は、従来構造でファンを有しない場合のＰＤＰでは８３℃であったが、本実施例では７８℃となり、５℃低下した。
【００１６】
《第２実施例》
図３及び図４を参照して本発明の第２実施例を説明する。図３は本発明の第２実施例のＰＤＰの図２と同じ位置での断面図である。図３に示す構成では、上部回路基板４Ａと下部回路基板４Ｂの筐体５１内での位置が、第１実施例の図２に示す位置と異なっている。その他の構成は図２のものと同じである。本実施例では取付ポスト３４の長さが取付ポスト３５の長さより短い。従って上部回路基板４Ａはパネル支持部材３の近くに配置され、下部回路基板４Ｂはパネル支持部材３から離れて配置されている。
【００１７】
図１に示す構成では、下部回路基板４Ｂ上の発熱部品５の近傍を通過中に温められた空気が上部回路基板４Ａの裏側を通る。そのため上部回路基板４Ａ自体がは下部回路基板４Ｂで温められた空気の影響を若干なりとも受け、放熱効果が低下する。図３の構成では開口部３１Ｂから流入する空気は下部回路基板４Ｂの裏側を通るのでほとんど温められることなく、外気温に近い温度を保ったまま上部回路基板４Ａの近傍を通過する。そのため上部回路基板４Ａの発熱部品５の冷却効果は図１のものより高くなる。本実施例のＰＤＰの筐体５１内の各部の気温の測定結果を図４に示す。図４において、上部回路基板４Ａの上部では６２℃、下部回路基板４Ｂの下部では４２℃であり、両者の中間部では４４℃であった。図４の温度を従来例の図１２の温度と比較すると、上部及び中間部の気温が大幅に低下していることがわかる。本実施例のＰＤＰと、図１０に示す従来のＰＤＰのファン１６を取外したものとを全く同じ条件で動作させ温度測定試験をした。その結果、従来のＰＤＰの上部回路基板４Ａに取り付けられた発熱部品５の温度は９８℃であったが、本実施例のＰＤＰの発熱部品５の温度は９３℃であり５℃低かった。下部回路基板４Ｂの発熱部品５の温度は、従来例のＰＤＰ及び本実施例のＰＤＰのいずれにおいても９２℃であり、同じであった。
【００１８】
《第３実施例》
図５を参照して本発明の第３実施例を説明する。図５は、本発明の第３実施例のＰＤＰの図２と同じ位置での断面図である。図５において、筐体５１、パネル１、熱伝導ゴムシート２及びパネル支持部材３の構成、及び筐体５１内の上部回路基板４Ａ及び下部回路基板４Ｂの配置位置は図１と同じである。本実施例では、上部回路基板４Ａの、発熱部品５を取り付けていない面に熱伝導ゴムシート２６を介してアルミニウム板等による放熱板８を設けている。放熱板８の、図の紙面に垂直な方向の幅は、上部回路基板４Ａの幅より大きくするのが望ましい。放熱板８の下端は通気孔３１近くまで延ばすのが望ましい。図５に示す放熱板８は、下部回路基板４Ｂとの間の間隔を広く保つために屈曲部８Ａで屈曲させている。
【００１９】
図５の構成によれば、通気孔３１から流入し、パネル１から遠い側の矢印３９Ａの経路を通る空気流と、パネル１に近い側の矢印３９Ｂの経路を通る空気流は放熱板８で分離されている。従って上部回路基板４Ａの近傍を通る空気は下部回路基板４Ｂの影響を全く受けず、気温は外気温と全く同じである。これにより上部回路基板４Ａの冷却効果が第１実施例のものに比べて向上する。また、上部回路基板４Ａの熱は上部回路基板４Ａから放熱板８に伝わり拡散する。これにより放熱板８の温度が上昇するが、放熱板８は矢印３９Ｂの経路を通る空気によって冷却され、熱拡散効果と気流による冷却効果により上部回路基板４Ａの冷却効果が向上する。上記両方の冷却効果の向上により、上部回路基板４Ａ上の発熱部品５の温度は第１実施例のものに比べて低くなる。本実施例のＰＤＰと従来構造でファンを取り外したＰＤＰについて温度測定試験をした。その結果、上部回路基板４Ａの発熱部品５の温度は、従来構造では９８℃であったが、本実施例では、８８℃となり１０℃低かった。下部回路基板４Ｂの発熱部品５の温度は、従来例のＰＤＰ及び本発明のＰＤＰのいずれにおいても９２℃であり同じであった。
【００２０】
本実施例で、熱伝導ゴムシート２６を介して上部回路基板４Ａに貼り付けている放熱板８の代わりに、樹脂製の遮蔽板を設けてもよい。この遮蔽板は上部回路基板４Ａに貼り付けず、上部回路基板４Ａとの間に隙間を保って配置してもよい。この場合遮蔽板への熱拡散がないため冷却効果は放熱板８を用いる場合より劣るが、軽量化とコスト低減が図れる。
【００２１】
《第４実施例》
本発明の第４実施例を図６を参照して説明する。図６は本発明の第４実施例のＰＤＰの図２と同じ位置での断面図である。図６において、筐体５１、パネル１、熱伝導ゴムシート２及びパネル支持部材３の構成及び筐体５１内の上部回路基板４Ａ及び下部回路基板４Ｂの配置位置は図１と同じである。本実施例では、筐体５１のバックカバー３７は樹脂で構成し、バックカバー３７の内面にアルミニウム等の放熱板４４を貼り付け、放熱板４４と上部回路基板４Ａの間に熱伝導性の軟らかい弾性部材２７を充填する。
【００２２】
本実施例によれば、上部回路基板４Ａの発熱部品５の熱がバックカバー３７に伝わり放熱される。本実施例のＰＤＰと従来例のＰＤＰについて温度測定試験をした。その結果、上部回路基板４Ａの発熱部品５の温度は、従来例では９８℃であったが、本実施例では７６℃になり大幅に低くなった。
バックカバー３７が金属でなく熱伝導性の悪い樹脂などの場合は、熱伝導性の軟らかい弾性部材２７は、上部回路基板４Ａ上の高さが異なる複数の発熱部品５とバックカバー３７との間に隙間なく充填される必要があるので、弾性を有するゲル状の充填材が望ましい。このような充填部材の例としては、富士高分子工業（株）製のサーコン（Ｒ）がある。この場合、バックカバー３７に多数の孔４５を設けて、放熱板４４が外気に触れるようにすると更に放熱効果が向上する。
【００２３】
図７は、図６に示す放熱板４４を変形した放熱板４４Ａを有する本実施例のＰＤＰの断面図である。放熱板４４Ａは、アルミニウム等の板を凸形に曲げて構成する。放熱板４４Ａの凸部と上部回路基板４Ａの発熱部品５との間に熱伝導性の軟らかい弾性部材２７を充填する。この構成によれば、発熱部品５の高さが低く、バックカバー３７との間が大きくても、熱伝導性の軟らかい弾性部材２７を厚くする必要はない。従って、熱伝導ゴムによる伝熱ロスを小さくでき、効率よく放熱板４４Ａに熱を伝えることができる。さらに、図６の矢印３９Ａで示す経路を流れる空気が、放熱板４４Ａの中空部４４Ｂの中を通るので、放熱板４４Ａは上昇気流３９Ａによっても冷却される。従って放熱板４４Ａの冷却効果が向上する。
従来構造でファンを取り外した場合と図７構成での温度測定試験を行ったところ、発熱部品５の温度は９８℃から９２℃まで低下できた。図７に示すＰＤＰでは、バックカバー全体を金属製とするよりも安価な樹脂製のバックカバー３７を用いることができるので、ＰＤＰの製造コストを低くおさえることが可能となる。
【００２４】
《第５実施例》
本発明の第５実施例を図８及び図９を参照して説明する。図８は本発明の第５実施例のＰＤＰの図２と同じ位置での断面図である。図８において、筐体１、パネル１、熱伝導ゴムシート２及びパネル支持部材３の構成及び筐体５１内の上部回路基板４Ａ及び下部回路基板４Ｂの配置位置は図３と同じである。本実施例では、パネル支持部材３の上部とバックカバー３７との間に複数の通気孔１３を有する格子状の放熱部材１２を設けている。放熱部材１２にはアルミニウム等の熱伝導率の高い材料を用いるのが望ましい。図９は図８のＸＩ−ＸＩ断面図である。矢印３９Ａ、３９Ｂで示す経路で筐体５１内を流れる空気は通気孔１３を通って排出される。放熱部材１２を設けたことにより、パネルで発生した熱はパネル支持部材３に伝わり、さらに放熱部材１２へ熱拡散される。放熱部材１２は筐体５１内を流れる空気流によって冷却されるので、パネル支持部材３の、下部より高温になる傾向にある上部の温度が下がりパネル支持部材３の温度分布の均一化が図れる。本実施例について前記したような温度測定実験をしたところ、パネル１の上部の最も温度の高い部分の温度が８５℃が８０℃になり、５℃低下した。パネル１の下部の温度は図１１に示す値と同じであった。パネル支持部材３の温度分布が均一化になることにより、パネル１の温度分布も均一になり、温度分布の不均一により熱膨張によるパネル１のガラスの歪みを防止できパネル１の破損を防ぐことができる。放熱部材としては上記のような多孔部材の他に、フィン形状でもよい。
【００２５】
【発明の効果】
以上の各実施例で詳細に説明したように、本発明の映像表示装置は、パネル上部の裏面に発熱部品を搭載した回路基板を配置しても、パネル上部の温度および前記回路基板上の部品の温度上昇を抑制することができる。これによりパネル面の温度むらは抑制されパネル破損を防ぐことができるとともに、部品の高温化による劣化及び破損を防止できる。
【図面の簡単な説明】
【図１】本発明の第１実施例のプラズマ表示装置の斜視図
【図２】図１のＩＩ−ＩＩ断面図
【図３】本発明の第２実施例のプラズマ表示装置の断面図
【図４】本発明の第２実施例のプラズマ表示装置の筐体内の空気温度の実測値を示す正面図
【図５】本発明の第３実施例のプラズマ表示装置の断面図
【図６】第４実施例の他の例のプラズマ表示装置の断面図
【図７】第４実施例の他の例のプラズマ表示装置の断面図
【図８】第５実施例のプラズマ表示装置の断面図
【図９】第５実施例のプラズマ表示装置の断面図
【図１０】従来のプラズマ表示装置の断面図
【図１１】従来のプラズマ表示装置のパネル表面の温度分布を示す正面図
【図１２】従来のプラズマ表示装置の筐体内の気温を示す正面図
【符号の説明】
１パネル
２熱伝導ゴムシート
３パネル支持部材
４Ａ、４Ｂ回路基板
５発熱部品
６、３１通気孔
７、３７バックカバー
８放熱板
１０、３０前カバー
１２放熱部材
４５放熱孔
１６ファン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in the assembly structure of a display panel and a display drive circuit in a plasma display device.
[0002]
[Prior art]
A plasma display device (hereinafter abbreviated as PDP) has a smaller depth, including the case, than a conventional display device using a cathode ray tube, is easy to enlarge, and is excellent in terms of brightness and contrast. Yes. Since the depth is small, it is promising as a public display device such as a showroom as a wall-mounted display or a display device used for presentations in a company. In addition, if it becomes cheaper by mass production, it seems that it will become widespread as a space-saving TV for home use. Since PDP uses plasma discharge as the light emission principle, a plasma display panel (hereinafter simply referred to as a panel) and a driving circuit generate a large amount of heat and raise the temperature in the housing as compared with a cathode ray tube or a liquid crystal display device. For this reason, if the heat is released to the outside of the housing and the temperature rise of the panel and the drive circuit are not suppressed, the display characteristics of the panel may be deteriorated or the life of the components attached to the circuit board may be shortened. If there is a large temperature difference in the panel surface, the panel glass may be damaged. PDPs tend to consume more power due to improvements in display brightness and built-in BS tuners. Since heat generation increases as the power consumption increases, heat dissipation becomes increasingly important.
[0003]
FIG. 10 is a sectional view of a casing 50 of a conventional PDP. The structure of a conventional PDP casing 50 will be described with reference to FIG. The housing 50 has a front cover 10 and a back cover 7. A PDP panel 1 is attached to the front cover 10. A heat conductive rubber sheet 2 having good heat conductivity is adhered to the back surface of the panel. A panel support member 3 made of an aluminum plate is adhered to the heat conductive rubber sheet 2 and attached. Generally, the panel support member 3 is made of, for example, an aluminum material having a high thermal conductivity, and has a role of diffusing the heat of the panel to the air in the housing. For example, two upper circuit boards 4A and a lower circuit board 4B are attached to the panel support member 3. Many components including the heat generating component 5 are attached to the upper circuit board 4A and the lower circuit board 4B. Heat generated from the panel 1 is transmitted to the panel support member 3 through the heat conductive rubber sheet 2 and is released from the surface of the panel support member 3 into the air. The panel support member 3 functions as a reinforcing material that holds the panel 1 and prevents deformation of the panel. The upper circuit board 4 A and the lower circuit board 4 B are attached to the panel support member 3 at a predetermined interval by a post 45 of an attachment member. A plurality of ventilation holes 6 are provided in the lower part of the back cover 7. A fan 16 is provided on the top of the housing 50. When the fan 16 is operated, the air flowing in from the vent hole 6 flows through the path indicated by the arrow 9 and is discharged to the outside by the fan 16. The panel support member 3 and the heat generating component 5 are cooled by the air flow flowing in through the air holes 6.
[0004]
In the conventional example, there is also a natural air cooling type housing that is not provided with the fan 16 and has only an exhaust hole in the upper part. In such a case, when the air is warmed by the heat generated from the heat generating component 5, the density of the air is reduced and an upward air flow is generated. The internal air is discharged from the upper exhaust hole by this rising air flow, and the cold air flows from the lower air hole 6. The generation of such an updraft in the housing is said to be the “chimney effect”. Since the PDP has a small depth and is normally used with the panel standing vertically, such an updraft is generated in the casing.
[0005]
[Problems to be solved by the invention]
In the PDP using the fan 16 shown in FIG. 10, an air flow with a wind speed of several m / s can be generated, so that the cooling effect is considerably higher than in the case of natural air cooling. However, the fan 16 becomes a noise source, and unless appropriate noise countermeasures are taken, the quality of the product is significantly reduced. Natural air cooling does not generate noise. However, because the air flow depends on the rising air flow due to the change in the air density, the wind speed is as low as about 0.5m / s at the maximum, and the cooling effect is limited.
[0006]
Further, in the above conventional heat dissipation method, regardless of the presence or absence of the fan, the air flowing in from the vent hole 6 is warmed when passing through the lower part of the panel support member 3 and the part of the heat generating component 5 on the lower circuit board 4B. The air temperature rises as the distance increases. Therefore, a difference arises in the cooling effect, and the temperature of the upper part of the panel 1 becomes higher than the temperature of the lower part. FIG. 11 is a front view showing a temperature distribution on the surface of a conventional natural air-cooled panel 1. In FIG. 11, the vertical direction in the figure corresponds to the vertical direction of the panel 1. As shown in FIG. 11, the upper temperature of panel 1 is 75 ° C. to 85 ° C., the lower temperature is 65 ° C. to 70 ° C., and there is a difference of 10 ° C. to 15 ° C. in the upper and lower sides. This is because even if the amount of heat generated by the panel 1 is almost uniform over the entire surface, the heat generated in the lower portion rises and hinders the cooling effect on the upper portion. FIG. 12 is a front view of the PDP in FIG. 10, and shows the result of measuring the temperature of the air flowing in the vicinity of the lower circuit board 4 B disposed in the lower part of the housing 50 and the upper circuit board 4 A disposed in the upper part. is there. As shown in FIG. 12, the temperature of the lower part of the housing 50 was 42 ° C., the temperature of the central part was 56 ° C., and the temperature of the upper part was 68 ° C. The temperature difference between the upper part and the lower part is about 24 ° C., indicating that the cooling effect on the upper part of the panel is low.
[0007]
In order to solve such a problem, a device that does not have a conventional fan may be devised to reduce the power consumption of the electric circuit, or a part that generates a large amount of heat may not be placed on the top of the housing 50. It was. However, due to the increase in various circuits built in the PDP, a high-density and large-sized circuit board has to be incorporated, and the arrangement of the circuit board has been restricted. That is, the upper circuit board 4 A having the heat generating component 5 has to be disposed on the upper part of the housing 50. As a result, not only the upper circuit board 4A but also the temperature of the upper part of the panel 1 is increased, the temperature difference in the surface of the panel 1 is enlarged, and the panel 1 is cracked or the heating component 5 is deteriorated or ignited due to a temperature rise. Will arise.
An object of the present invention is to provide a PDP that can suppress an increase in the temperature of a panel and the temperature of a circuit component even when a circuit board that generates a large amount of heat is provided at the top of the housing.
[0008]
[Means for Solving the Problems]
The plasma display device of the present invention is a flat panel support member to which a plasma display panel is attached, a plurality of upper and lower parts which are attached substantially in parallel to the panel support member and have different spacings from the panel support member. The circuit board having a heat generating component, the panel support member and the circuit board are accommodated, and a housing having a vent hole below the circuit board and an exhaust hole above is provided.
According to the present invention, since the distance between each of the plurality of circuit boards and the panel support member is different, the air flowing in from the lower vent and flowing upward in the housing is divided for each circuit board. Take the route. Therefore, the air heated through the region including the heat generating component on the lower circuit board does not hit the heat generating component on the upper circuit board. The upper circuit board is exposed to air having substantially the same temperature as the outside air temperature flowing in from the vent hole. Therefore, the cooling effect equivalent to that of the lower circuit board can be obtained without the heat dissipation of the upper circuit board being hindered by the rise in the temperature of the rising airflow as in the prior art.
[0009]
Among the plurality of circuit boards, an interval between the upper circuit board disposed at the upper part of the housing and the panel support member is made wider than an interval between the lower circuit board disposed at the lower part and the panel support member, Air that has flowed in from the air holes and passed through the region including the lower circuit board disposed at the lower part passes between the upper circuit board disposed at the upper part and the panel support member and flows out from the exhaust hole. Features.
Since the unheated air passing through the path away from the lower circuit board passes near the upper board, the cooling effect of the upper board is high.
[0010]
Among the plurality of circuit boards, the distance between the upper circuit board disposed at the upper part of the housing and the panel support member is made smaller than the distance between the lower circuit board disposed at the lower part and the panel support member, and It is characterized in that the air flowing in from the air holes and passing between the panel support member and the lower circuit board disposed below passes through the region including the upper circuit board disposed in the upper part and flows out from the exhaust hole. To do.
Air that has been warmed by passing near the lower circuit board does not pass near the upper circuit board, and unwarmed air that passes between the panel support member and the lower circuit board passes near the upper board. High effect.
[0011]
It is provided between a plurality of upper and lower circuit boards that are different from each other in distance to the panel support member, and passes through a path that divides the air flowing from the vent holes into the plurality of upper and lower circuit boards. In addition, a plate-like member for branching is further provided.
Since the respective paths of the upper and lower circuit boards are separated by the plate-like member, both the upper and lower circuit boards are cooled by receiving an air flow having substantially the same temperature as the outside air. Therefore, there is no difference in the cooling effect of both circuit boards.
The plate member is a metal plate, and is attached to the upper circuit board so that heat of the upper circuit board is transmitted to the plate member.
Since the metal plate member is attached to the upper circuit board, the heat of the upper circuit board is transferred to the plate member. Therefore, the cooling effect of the upper circuit board is further enhanced.
[0012]
The casing is made of resin, a metal plate is provided inside a predetermined portion, and the metal plate and the heat generating component of the upper circuit board are connected by a heat conductive member.
Even if the housing is made of resin and has poor thermal conductivity, the heat of the heat generating component is dissipated from the inner metal plate, so the heat dissipation effect of the upper circuit board is high.
A heat radiation hole is provided in a predetermined portion of the casing provided with the metal plate.
Since the metal plate is exposed to the outside air at the heat radiation hole portion of the housing, the cooling effect of the upper circuit board attached to the metal plate is high.
A heat radiating member is provided on the rear surface of the upper region of the panel support member.
Since the heat of the panel support member is dissipated by the heat dissipation member, the panel cooling effect is high.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the plus display device (PDP) of the present invention will be described with reference to FIGS. In each cross-sectional view, the horizontal dimension corresponding to the depth of the PDP is enlarged for easy understanding.
[0014]
<< First Example >>
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a PDP according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line II-II in FIG. 1 and 2, a heat conductive rubber sheet 2 having good heat conductivity is attached to the back surface of the panel 1 of the PDP. The heat conductive rubber sheet 2 is a composite material of silicon and rubber and is generally commercially available. A panel support member 3 made of, for example, an aluminum plate is attached to the heat conductive rubber sheet 2. These structures are the same as the conventional one shown in FIG. The housing 51 includes a front cover 30 and a back cover 37, and the front cover 30 has an opening 30 A. The casing 51 is made of metal or plastic. Panel 1 is attached to opening 30A. The casing 51 has a vent hole 31 in the lower part and an exhaust hole 32 in the upper part in the figure. For example, two upper circuit boards 4 A and a lower circuit board 4 B to which an electronic circuit including a heat generating component 5 that controls the panel 1 is attached are provided inside the casing 51. The upper circuit board 4 A is attached to the panel support member 3 by four attachment posts 34. The lower circuit board 4 B is attached to the panel support member 3 by four attachment posts 35 shorter than the attachment posts 34. By changing the length of each of the mounting posts 34 and 35, the distance between the panel support member 3 and the upper circuit board 4A and the lower circuit board 4B can be changed. For example, the upper circuit board 4A is separated from the panel support member 3 by about 40 mm, and the lower circuit board 4B is separated from the panel support member 3 by about 10 mm.
[0015]
By arranging the upper circuit board 4A and the lower circuit board 4B in this way, the air flowing from the opening 31B of the vent hole 31 and passing through the vicinity of the heat generating component 5 on the lower circuit board 4B is a path indicated by an arrow 39B. And then flows out of the exhaust hole 32. On the other hand, the air that has flowed from the opening 31A of the vent hole 31 away from the lower circuit board 4B passes through the space between the lower circuit board 4B and the rear cover 37 along the path indicated by the arrow 39A, and the air flows above the upper circuit board 4A. It flows out from the exhaust hole 32 through the vicinity of the heat-generating component 5 mounted on the. The air flowing in from the opening portion 31B cools the heat generating component 5 on the circuit board when passing through the vicinity of the lower circuit board 4B. Thus, the heated air flows out between the upper circuit board 4A and the panel support member 3 to the outside. Accordingly, the heat generating component 5 on the upper circuit board 4A hardly touches the heated air. On the other hand, the outside air flowing in from the opening portion 31A passes through a path 39A away from the lower circuit board 4B. Therefore, the temperature does not increase and passes through the vicinity of the upper circuit board 4A while maintaining substantially the same temperature as the outside air temperature. As a result, the heat generating component 5 on the upper circuit board 4A is cooled by air having substantially the same temperature as the outside air temperature.
The PDP of this example and the conventional PDP shown in FIG. 10 with the fan 16 removed were operated under exactly the same conditions such as the ambient temperature, and the temperature of each part was measured. The temperature of the highest temperature portion of the PDP panel 1 when the fan is removed in the conventional structure (panel maximum temperature) was 88 ° C., but the maximum panel temperature of the PDP in this example was 84 ° C. The temperature decreased. Further, the temperature of the specific heat generating component on the upper circuit board 4A was 83 ° C. in the PDP having the conventional structure and having no fan, but was 78 ° C. in this example, which was decreased by 5 ° C.
[0016]
<< Second Embodiment >>
A second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a sectional view of the PDP according to the second embodiment of the present invention at the same position as FIG. In the configuration shown in FIG. 3, the positions of the upper circuit board 4A and the lower circuit board 4B in the housing 51 are different from the positions shown in FIG. 2 of the first embodiment. Other configurations are the same as those in FIG. In this embodiment, the length of the mounting post 34 is shorter than the length of the mounting post 35. Accordingly, the upper circuit board 4 A is disposed near the panel support member 3, and the lower circuit board 4 B is disposed away from the panel support member 3.
[0017]
In the configuration shown in FIG. 1, the air heated while passing near the heat generating component 5 on the lower circuit board 4B passes through the back side of the upper circuit board 4A. Therefore, the upper circuit board 4A itself is slightly affected by the air heated by the lower circuit board 4B, and the heat dissipation effect is reduced. In the configuration of FIG. 3, the air flowing in from the opening 31B passes through the back side of the lower circuit board 4B, so that it hardly gets warm and passes through the vicinity of the upper circuit board 4A while maintaining a temperature close to the outside air temperature. Therefore, the cooling effect of the heat generating component 5 of the upper circuit board 4A is higher than that of FIG. FIG. 4 shows the measurement results of the temperature of each part in the casing 51 of the PDP of this example. In FIG. 4, the temperature was 62 ° C. at the upper part of the upper circuit board 4A, 42 ° C. at the lower part of the lower circuit board 4B, and 44 ° C. at the intermediate part between the two. Comparing the temperature of FIG. 4 with the temperature of FIG. 12 of the conventional example, it can be seen that the temperature of the upper part and the middle part is greatly reduced. A temperature measurement test was performed by operating the PDP of this example and the conventional PDP shown in FIG. 10 with the fan 16 removed under exactly the same conditions. As a result, the temperature of the heat generating component 5 attached to the upper circuit board 4A of the conventional PDP was 98 ° C., but the temperature of the heat generating component 5 of the PDP of this example was 93 ° C., which was 5 ° C. lower. The temperature of the heat generating component 5 of the lower circuit board 4B was 92 ° C. in both the conventional PDP and the PDP of the present example, and was the same.
[0018]
<< Third embodiment >>
A third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view of the PDP according to the third embodiment of the present invention at the same position as FIG. In FIG. 5, the structure of the housing | casing 51, the panel 1, the heat conductive rubber sheet 2, and the panel support member 3, and the arrangement position of 4 A of upper circuit boards and the lower circuit board 4B in the housing | casing 51 are the same as FIG. In the present embodiment, a heat radiating plate 8 made of an aluminum plate or the like is provided on the surface of the upper circuit board 4A on which the heat generating component 5 is not attached via a heat conductive rubber sheet 26. The width of the heat radiating plate 8 in the direction perpendicular to the drawing sheet is desirably larger than the width of the upper circuit board 4A. It is desirable to extend the lower end of the heat sink 8 to the vicinity of the vent hole 31. The heat radiating plate 8 shown in FIG. 5 is bent at the bent portion 8A in order to keep a wide space between the heat radiating plate 8 and the lower circuit board 4B.
[0019]
According to the configuration of FIG. 5, the airflow flowing through the vent hole 31 and passing through the path indicated by the arrow 39A far from the panel 1 and the airflow passing through the path indicated by the arrow 39B closer to the panel 1 are It is separated. Accordingly, the air passing in the vicinity of the upper circuit board 4A is not affected by the lower circuit board 4B at all, and the air temperature is exactly the same as the outside air temperature. Thereby, the cooling effect of the upper circuit board 4A is improved as compared with that of the first embodiment. The heat of the upper circuit board 4A is transferred from the upper circuit board 4A to the heat sink 8 and diffused. As a result, the temperature of the heat sink 8 rises, but the heat sink 8 is cooled by the air passing through the path indicated by the arrow 39B, and the cooling effect of the upper circuit board 4A is improved by the heat diffusion effect and the cooling effect by the airflow. By improving both the cooling effects, the temperature of the heat generating component 5 on the upper circuit board 4A becomes lower than that of the first embodiment. A temperature measurement test was performed on the PDP of this example and the PDP with a conventional structure with the fan removed. As a result, the temperature of the heat generating component 5 of the upper circuit board 4A was 98 ° C. in the conventional structure, but was 88 ° C. and 10 ° C. lower in this example. The temperature of the heat generating component 5 of the lower circuit board 4B was 92 ° C. in both the conventional PDP and the PDP of the present invention, and was the same.
[0020]
In this embodiment, a resin shielding plate may be provided instead of the heat radiating plate 8 attached to the upper circuit board 4A via the heat conductive rubber sheet 26. The shielding plate may not be attached to the upper circuit board 4A and may be arranged with a gap between the upper circuit board 4A. In this case, since there is no thermal diffusion to the shielding plate, the cooling effect is inferior to that when the heat radiating plate 8 is used, but the weight can be reduced and the cost can be reduced.
[0021]
<< 4th Example >>
A fourth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view of the PDP according to the fourth embodiment of the present invention at the same position as FIG. In FIG. 6, the configurations of the casing 51, the panel 1, the heat conductive rubber sheet 2, and the panel support member 3, and the arrangement positions of the upper circuit board 4A and the lower circuit board 4B in the casing 51 are the same as those in FIG. In this embodiment, the back cover 37 of the casing 51 is made of resin, and a heat radiating plate 44 such as aluminum is attached to the inner surface of the back cover 37, and the heat conductive soft material between the heat radiating plate 44 and the upper circuit board 4A. The elastic member 27 is filled.
[0022]
According to the present embodiment, the heat of the heat generating component 5 of the upper circuit board 4A is transmitted to the back cover 37 and radiated. A temperature measurement test was performed on the PDP of this example and the PDP of the conventional example. As a result, the temperature of the heat generating component 5 of the upper circuit board 4A was 98 ° C. in the conventional example, but was 76 ° C. in the present example, which was significantly reduced.
When the back cover 37 is not a metal but a resin having poor thermal conductivity, the elastic member 27 having a low thermal conductivity is provided between the back cover 37 and the plurality of heat generating components 5 having different heights on the upper circuit board 4A. Therefore, a gel-like filler having elasticity is desirable. An example of such a filling member is Sircon (R) manufactured by Fuji Polymer Industries Co., Ltd. In this case, if a large number of holes 45 are provided in the back cover 37 so that the heat radiating plate 44 comes into contact with the outside air, the heat radiation effect is further improved.
[0023]
FIG. 7 is a cross-sectional view of the PDP of this embodiment having a heat radiating plate 44A obtained by modifying the heat radiating plate 44 shown in FIG. The heat radiating plate 44A is formed by bending a plate made of aluminum or the like into a convex shape. A soft elastic member 27 having thermal conductivity is filled between the convex portion of the heat radiating plate 44A and the heat generating component 5 of the upper circuit board 4A. According to this configuration, even if the height of the heat generating component 5 is low and the space between the back cover 37 is large, it is not necessary to increase the thickness of the elastic member 27 that is soft and thermally conductive. Therefore, heat transfer loss due to the heat conductive rubber can be reduced, and heat can be efficiently transferred to the heat radiating plate 44A. Furthermore, since the air flowing through the path indicated by the arrow 39A in FIG. 6 passes through the hollow portion 44B of the heat radiating plate 44A, the heat radiating plate 44A is also cooled by the rising air flow 39A. Therefore, the cooling effect of the heat sink 44A is improved.
When the temperature measurement test was performed with the conventional structure with the fan removed and the configuration shown in FIG. 7, the temperature of the heat generating component 5 could be lowered from 98 ° C. to 92 ° C. In the PDP shown in FIG. 7, since the back cover 37 made of a resin can be used at a lower cost than when the entire back cover is made of metal, the manufacturing cost of the PDP can be reduced.
[0024]
<< 5th Example >>
A fifth embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a cross-sectional view of the PDP of the fifth embodiment of the present invention at the same position as FIG. In FIG. 8, the configuration of the casing 1, the panel 1, the heat conductive rubber sheet 2, and the panel support member 3, and the arrangement positions of the upper circuit board 4A and the lower circuit board 4B in the casing 51 are the same as those in FIG. In the present embodiment, a lattice-shaped heat radiation member 12 having a plurality of air holes 13 is provided between the upper portion of the panel support member 3 and the back cover 37. It is desirable to use a material having high thermal conductivity such as aluminum for the heat radiating member 12. 9 is a cross-sectional view taken along line XI-XI in FIG. Air flowing in the casing 51 along the path indicated by the arrows 39A and 39B is discharged through the vent hole 13. By providing the heat radiating member 12, the heat generated in the panel is transmitted to the panel support member 3, and is further thermally diffused to the heat radiating member 12. Since the heat radiating member 12 is cooled by the airflow flowing through the housing 51, the temperature of the upper portion of the panel support member 3 that tends to be higher than the lower portion is lowered, and the temperature distribution of the panel support member 3 can be made uniform. As a result of the temperature measurement experiment as described above with respect to this example, the temperature of the highest temperature portion at the top of the panel 1 was changed from 85 ° C. to 80 ° C. and decreased by 5 ° C. The temperature at the bottom of panel 1 was the same as the value shown in FIG. By making the temperature distribution of the panel support member 3 uniform, the temperature distribution of the panel 1 also becomes uniform, and the distortion of the glass of the panel 1 due to thermal expansion can be prevented due to the non-uniform temperature distribution, thereby preventing the panel 1 from being damaged. Can do. The heat radiating member may have a fin shape in addition to the porous member as described above.
[0025]
【The invention's effect】
As described in detail in each of the embodiments described above, the video display device of the present invention has the temperature of the upper part of the panel and the components on the circuit board even if the circuit board having the heat generating component mounted on the back surface of the upper part of the panel. Temperature rise can be suppressed. Thereby, the temperature unevenness of the panel surface can be suppressed and the panel can be prevented from being damaged, and the deterioration and damage due to the high temperature of the components can be prevented.
[Brief description of the drawings]
1 is a perspective view of a plasma display device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1. FIG. 3 is a cross-sectional view of a plasma display device according to a second embodiment of the present invention. 4 is a front view showing an actual measurement value of the air temperature in the casing of the plasma display device of the second embodiment of the present invention. FIG. 5 is a cross-sectional view of the plasma display device of the third embodiment of the present invention. FIG. 7 is a sectional view of a plasma display device according to another example of the fourth embodiment. FIG. 8 is a sectional view of a plasma display device according to another example of the fourth embodiment. FIG. 10 is a sectional view of a conventional plasma display device. FIG. 11 is a front view showing the temperature distribution on the panel surface of the conventional plasma display device. Front view showing the temperature inside the housing of the display device 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Panel 2 Thermal conductive rubber sheet 3 Panel support member 4A, 4B Circuit board 5 Heat generating component 6, 31 Vent hole 7, 37 Back cover 8 Heat sink 10, 30 Front cover 12 Heat sink 45 Heat sink 16 Fan

Claims

A flat panel support member with a plasma display panel attached,
A circuit board having a plurality of upper and lower heat generating components attached substantially parallel to the panel support member and spaced apart from each other by the panel support member; and housing the panel support member and the circuit board, A plasma display device having a housing having a vent hole below the substrate, an exhaust hole above, and covering the back of the panel support member.

Among the plurality of circuit boards, an interval between the upper circuit board disposed at the upper part of the housing and the panel support member is made wider than an interval between the lower circuit board disposed at the lower part and the panel support member, Air that has flowed in from the air holes and passed through the region including the lower circuit board disposed at the lower part passes between the upper circuit board disposed at the upper part and the panel support member and flows out from the exhaust hole. The plasma display device according to claim 1.

Among the plurality of circuit boards, the distance between the upper circuit board disposed at the upper part of the housing and the panel support member is made smaller than the distance between the lower circuit board disposed at the lower part and the panel support member, and It is characterized in that the air flowing in from the air holes and passing between the panel support member and the lower circuit board disposed below passes through the region including the upper circuit board disposed in the upper part and flows out from the exhaust hole. The plasma display device according to claim 1.

It is provided between a plurality of upper and lower circuit boards that are different from each other in distance to the panel support member, and passes through a path that divides the air flowing from the vent holes into the plurality of upper and lower circuit boards. The plasma display device according to claim 1, further comprising a plate-like member to be divided.

5. The plasma display device according to claim 4, wherein the plate-like member is a metal plate and is attached to the upper circuit board so that heat of the upper circuit board is transmitted to the plate-like member.

2. The plasma according to claim 1, wherein the casing is made of resin, a metal plate is provided inside a predetermined portion, and the metal plate and a heat generating component of the upper circuit board are connected by a heat conductive member. Display device.

The plasma display device according to claim 1, wherein a heat radiating member is provided on the rear surface of the upper region of the panel support member.