JP3592693B2 - Plasma display panel heating prevention method and apparatus, and plasma display apparatus using the same - Google Patents

Description

上記式（９）は１℃のパネル温度上昇に対する輝度補正として、維持放電電圧Ｖ_Ｓ を０．１３２Ｖ増加すればよいことを示す。
【０１４３】
また、第１参考例と同様に、これはＦＥＴ温度が１℃上昇すると輝度が０．３３カンデラ低下する。よって、ＦＥＴ温度変化分をΔＴ_ｆ とすると（１０）式が成り立つ。
【０１４４】
Ｂ＝−０．３３×ΔＴ_ｆ …（１０）
式（７）のＶ_Ｓ をＶ_Ｓ２とすると、式（７）と式（１０）により式（１１）が導かれる。
【０１４５】

式（１１）は１℃のＦＥＴ温度上昇に対する輝度補正として、Ｖ_Ｓ を０．１３２Ｖ増加すればよいことを示す。
【０１４６】
以上の検討から、式（９）と式（１１）による輝度補正を同時に行えば目的の輝度補正が実現可能となり、このときの各温度変化分と制御を行う補正維持放電電圧Ｖ_Ｓ３の関係を式（１２）に示す。
【０１４７】

上記式（１２）は１℃のＦＥＴ温度上昇あるいはパネルの温度上昇に対する輝度補正として、維持放電電圧Ｖ_Ｓ を０．１３２Ｖ増加すればよいことを示す。
【０１４８】
次に、上記式（１２）を実現する具体的動作について説明する。
【０１４９】
始めに、ＰＤＰ１の表面温度の検出及びＸ共通ドライバ４及びＹ共通ドライバ７の温度の検出については第１参考例と同様であるので、細部の説明は省略する。
【０１５０】
マイコン９０はＸ共通ドライバ４及びＹ共通ドライバ７の温度情報である検出信号Ｓ_ＴＸ及びＳ_ＴＹに対応する温度の平均値を求め、基準値となる５５℃との差ΔＴ_ｆ を算出する。これと平行して、マイコン９０は、ＰＤＰ１の温度情報である検出信号Ｓ_ＴＰに対応する温度と、基準値との差ΔＴ_ｐ を算出し、上記式（１２）に基づき、基準維持放電電圧Ｖ_ＳＲに対する補正数Ｖ_Ｓ３を算出する。
【０１５１】
ここで、上述のように、マイコン９０は維持放電電圧基準電圧出力部ＯＵＴに接続されており、これにより維持放電電圧Ｖ_Ｓ のマイコン９０による制御が可能となっていので、マイコン９０は基準維持放電電圧Ｖ_ＳＲと補正数Ｖ_Ｓ３の和を算出し、その結果が維持放電電圧基準電圧出力部ＯＵＴから外部の高電圧発生装置へ出力され、駆動用高圧入力部ＩＮ_Ｖ に入力されるべき電圧値の基準となり、当該基準地に基づき、共通ドライバ制御部３１により維持放電電圧Ｖ_Ｓ が設定される。
【０１５２】
以上説明したように、第２参考例によれば、簡易な回路構成により温度情報に基づく輝度微調整（輝度補正）が可能である。
（ ＩＶ ）第３参考例
次に、第３の参考例の動作について図１及び図４を用いて説明する。
【０１５３】
第３参考例においては、ＰＤＰ１の表面温度が温度検出器１０により検出され、更にＸ共通ドライバ４及びＹ共通ドライバ７の温度がそれぞれ温度検出器５及び８により検出される。そして、それぞれの温度検出器から出力される検出信号Ｓ_ＴＰ、Ｓ_ＴＸ及びＳ_ＴＹに基づき、ＰＤＰ１自体又は各共通ドライバの温度上昇により低下したＰＤＰ１の輝度が補正される。より具体的には、表示データＤＡＴＡにおける各サブフレームの階調値データが補正される。
【０１５４】
図４に階調値と輝度との関係を示す。
【０１５５】
図４に示しように、階調値に輝度が比例しており、この例では０．７８カンデラ／ＳＴＥＰ、つまり階調値１ステップに付き０．７８カンデラの調整が可能であることが分かる。
【０１５６】
輝度をＢ、階調ステップをＳとすると下記式（１３）が成り立つ。
【０１５７】
Ｂ＝０．７８×Ｓ …（１３）
ここで、第１参考例と同様に、ＰＤＰ１の温度が１℃上昇すると輝度は０．３３カンデラ低下する。そこで、パネル温度変化分をΔＴ_ｐ とすると下記式（１４）が成り立つ。
【０１５８】
Ｂ＝−０．３３×ΔＴ_ｐ …（１４）
上記式（１３）のＳをＳ_１ とすると、式（１３）と式（１４）により下記式（１５）が導かれる。
【０１５９】
０．７８×Ｓ_１ ＝−０．３３×ΔＴ_ｐ
Ｓ_１ ＝−０．４２３×ΔＴ_ｐ …（１５）
上記式（１５）は１℃のパネル温度上昇に対する輝度補正として、階調値を０．４２３ｓｔｅｐ増加すればよいことを示す。
【０１６０】
また、第１参考例と同様に、ＦＥＴ温度が１℃上昇すると輝度は０．３３カンデラ低下する。そこで、ＦＥＴ温度変化分をΔＴ_ｆ とすると下記式（１６）が成り立つ。
【０１６１】
Ｂ＝−０．３３×ΔＴ_ｆ …（１６）
上記（１３）のＳをＳ_２ とすると、式（１３）と式（１６）により下記式（１７）が導かれる。
【０１６２】

（１７）式は１℃のＦＥＴ温度上昇に対する輝度補正として、階調値を０．４２３ｓｔｅｐ増加すればよいことを示す。
【０１６３】
以上の検討のように、式（１５）及び式（１７）における輝度補正を同時に行えば目的の輝度補正が実現可能となる。このときの各温度変化分と制御を行う補正階調値Ｓ_３ の関係を下記式（１８）に示す。
【０１６４】

式（１８）は１℃のＦＥＴ温度上昇あるいはＰＤＰ１の温度上昇に対する輝度補正として、階調値を０．４２３ｓｔｅｐ増加すればよいことを示す。
【０１６５】
次に、上記式（１８）を実現する具体的動作について説明する。
【０１６６】
ＰＤＰ１の表面温度の検出及びＸ共通ドライバ４及びＹ共通ドライバ７の温度の検出については第１参考例と同様であるので、細部の説明は省略する。
【０１６７】
マイコン９０は、表示データ制御部１１に接続されており、表示データ制御部１１ではマイコン９０からの減算データに基づき各発光セルＣの階調値の減算を行っている。これにより、階調値のマイコン９０による制御が可能となる。
【０１６８】
マイコン９０はＸ共通ドライバ４及びＹ共通ドライバ７の温度情報である検出信号Ｓ_ＴＸ及びＳ_ＴＹに対応する温度の平均値を求め、基準値となる５５℃との差ΔＴ_ｆ を算出し、次に、ＰＤＰ１の温度情報である検出信号Ｓ_ＴＰと基準値２５℃との差ΔＴ_ｐ を算出し、上記式（１８）に基づき、補正階調値Ｓ_３ を算出し、その結果を表示データ制御部１１に出力する。
【０１６９】
表示データ制御部１１ではマイコン９０からの補正階調値Ｓ_３ のデータを元に、表示データ入力部ＩＮから入力された表示データＤＡＴＡの変換を行う。表示データＤＡＴＡは垂直同期期間ｎにおいて一旦フレームメモリ２０に記憶保持される。次の垂直同期機関ｎ＋１でフレームメモリ２０のデータは減算器２１を介して輝度補正分の階調値を差し引いた後、制御信号Ｓ_Ａ に含まれる表示データとしてアドレスドライバ３に出力されＰＤＰ１に画像が表示される。この垂直同期期間ｎ＋１において表示データ制御部１１に入力される表示データＤＡＴＡはフレームメモリ２２に記憶保持される。
【０１７０】
以上の動作を二つのフレームメモリ２０及び２２に交互に動作させることにより、表示データの処理を行い、これら一連の動作により温度上昇による輝度低下の補正が実現される。
【０１７１】
以上説明したように、第３参考例によれば、高圧系の変更なしに輝度微調整が可能であり、また例えばマイコン等による制御を行っている場合ソフトウエアの変更のみで様々な制御が可能となるとともに、消費電力を増加させずに輝度補正を制御できる。
（Ｖ）第４参考例
次に、第４の参考例について図１、図５に基づいて説明する。
【０１７２】
上述のように、全ての選択された発光セルＣに正常にアドレス放電を行うために最低限必要なスキャンパルスＰ_ＡＹの電圧値である最小アドレス電圧Ｖ_ｙｍｉｎは、図１６に示す通り温度が上昇するに従って大きくなってしまう。
【０１７３】
一方、全ての選択されていない発光セルＣがオーバライトしない最大のスキャンパルスＰ_ＡＹの電圧値であるオーバライト電圧ＯＷＶ_ｙｍａｘは、図１６に示す通り温度が低下するに従って小さくなってしまう。
【０１７４】
そこで、第４参考例では、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ がＰＤＰ１の温度に基づいて可変とされ、常に、最小アドレス電圧Ｖ_ｙｍｉｎとオーバライト電圧ＯＷＶ_ｙｍａｘで設定される適正範囲内とされる。
【０１７５】
図１６の例では、最小アドレス電圧Ｖ_ｙｍｉｎとオーバライト電圧ＯＷＶ_ｙｍａｘ共に１℃の温度上昇に対して０．１７ボルトの変動がある。ＰＤＰ１の温度変動をΔＴ_ｐ 、最小アドレス電圧Ｖ_ｙｍｉｎの変動をΔＶ_ｙｍｉｎ、オーバライト電圧ＯＷＶ_ｙｍａｘの変動をΔＶ_ｙｍａｘとすると下記式（１９）及び式（２０）が成り立つ。
【０１７６】
ΔＶ_ｙｍｉｎ ＝０．１７×ΔＴ_ｐ …（１９）
ΔＯＷＶ_ｙｍａｘ＝０．１７×ΔＴ_ｐ …（２０）
スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ の設定値は一般に最小アドレス電圧Ｖ_ｙｍｉｎとオーバライト電圧Ｖ_ｙｍａｘの中間とするのが好ましいことから、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ の設定値の補正値をΔＶ_ｙ とすると上記式（１９）と式（２０）により下記式（２１）が成り立つ。
【０１７７】
ΔＶ_ｙ ＝０．１７×ΔＴ_ｐ …（２１）
式（２１）は１℃の温度上昇に対し、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ を０．１７ボルト大きくすればよいことを示している。
【０１７８】
次に、上記式（２１）を実現する具体的動作について説明する。
【０１７９】
ＰＤＰ１の表面温度の検出については第１参考例と同様であるので、細部の説明は省略する。
【０１８０】
マイコン９０は電圧変換部４０内のＶ_ｙ 電源部４４に接続されており、アドレス放電を行うためのスキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ をマイコン９０により制御することが可能となっている。
【０１８１】
そこで、マイコン９０はＰＤＰ１の温度情報である検出信号Ｓ_ＴＰに対応する温度と基準値２５℃との差ΔＴ_ｐ を算出し、式（２１）に基づき、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ における基準電位に対する補正値ΔＶ_ｙ を算出する。次にマイコン９０はスキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ と補正値ΔＶ_ｙ の和を算出し、その結果を電圧変換部４０内のＶ_ｙ 電源部４４に出力する。これにより、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ の補正制御が可能となる。
【０１８２】
以上説明したように、第４参考例によれば、温度変動による駆動マージン変動に対応することができ、図５に示すように、駆動マージンの幅が狭い場合においても、常にスキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ が適性範囲内となり、駆動マージンの幅が広い場合と同様の良好な表示が実現可能となる。
（ ＶＩ ）第５参考例
次に、第５の参考例について図１、図６に基づいて説明する。
【０１８３】
第５参考例においては、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ を常に適性範囲内とする方法として、最小アドレス電圧Ｖ_ｙｍｉｎとオーバライト電圧ＯＷＶ_ｙｍａｘを変化させる。より具体的には、壁電荷蓄積期間においてＸ電極Ｘ_１ 乃至Ｘ_Ｎ に印加される電圧（Ｘアドレス電圧Ｖ_Ｘ ）を制御し、これにより、オーバライト電圧Ｖ_{ｙｍ ａｘ}に関しては、低温時には高く、高温時には低くなるように変化させ、最小アドレス電圧Ｖ_ｙｍｉｎに関しても、同様に低温時には高く、高温時には低くなるように変化させる。
【０１８４】
ここで、図６に、Ｘアドレス電圧Ｖ_Ｘ とオーバライト電圧ＯＷＶ_ｙｍａｘ及び最小アドレス電圧Ｖ_ｙｍｉｎの関係を示す。
【０１８５】
図６に示すように、Ｘアドレス電圧Ｖ_Ｘ が低い時はオーバライト電圧ＯＷＶ_ｙｍａｘが高い反面、最小アドレス電圧Ｖ_ｙｍｉｎは上昇する。これに対し、Ｘアドレス電圧Ｖ_Ｘ が高い時は最小アドレス電圧Ｖ_ｙｍｉｎが低い反面オーバライト電圧ＯＷＶ_ｙｍａｘは低い。よって、Ｘアドレス電圧Ｖ_Ｘ を制御することにより、温度によるスキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ の適性範囲の変動を補正することが可能であり、具体的には、高温時はＸアドレス電圧Ｖ_Ｘ を高く、低温時にはＸアドレス電圧Ｖ_Ｘ を低く制御すればよい。
【０１８６】
より具体的には、ＰＤＰ１の温度変動をΔＴ_Ｐ 、最小アドレス電圧Ｖ_ｙｍｉｎの変動をΔＶ_ｙｍｉｎ、オーバライト電圧ＯＷＶ_ｙｍａｘの変動をΔＯＷＶ_ｙｍａｘとすると図１６又は図１７の例では下記式（１９）及び式（２０）が成り立つ。
【０１８７】
ΔＶ_ｙｍｉｎ ＝０．１７×ΔＴ_ｐ …（１９）
ΔＯＷＶ_ｙｍａｘ＝０．１７×ΔＴ_ｐ …（２０）
図６に示すのスキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ とＸアドレス電圧Ｖ_Ｘ の関係では、Ｘアドレス電圧Ｖ_Ｘ の変化分ΔＶ_Ｘ に対する最小アドレス電圧Ｖ_ｙｍｉｎの変動をΔＶ_ｙｍｉｎ、オーバライト電圧ＯＷＶ_ｙｍａｘの変動をΔＯＷＶ_ｙｍａｘとすると下記式（２１）及び式（２２）が成り立つ。
【０１８８】
ΔＶ_ｙｍｉｎ ＝−０．５×ΔＶ_Ｘ …（２１）
ΔＯＷＶ_ｙｍａｘ＝−０．５×ΔＶ_Ｘ …（２２）
上記式（１９）及び式（２１）並びに、式（２０）及び式（２２）からそれぞれ下記の式（２３）及び式（２４）が導き出すことができる。
【０１８９】
ΔＶ_Ｘ ＝−０．３４×ΔＶ_ｐ …（２３）
ΔＶ_Ｘ ＝−０．３４×ΔＶ_ｐ …（２４）
上記式（２３）及び式（２４）は共に、１℃の温度上昇に対してＶ_Ｘ を０．３４ボルト低下させることにより、ＰＤＰ１の温度変動による最小アドレス電圧Ｖ_ｙｍｉｎ及びオーバライト電圧ＯＷＶ_ｙｍａｘの変動を解消することができ、ＰＤＰ１の温度が変動しても、図７に示すように、常に最小アドレス電圧Ｖ_ｙｍｉｎ及びオーバライト電圧ＯＷＶ_ｙｍａｘを略一定にすることができることを示している。
【０１９０】
次に、上記式（２３）及び式（２４）を実現する具体的動作について説明する。
【０１９１】
ＰＤＰ１の表面温度の検出については第１参考例と同様であるので、細部の説明は省略する。
【０１９２】
マイコン９０は電圧変換部４０内のＶ_Ｘ 電源部４５に接続されており、Ｘアドレス電圧Ｖ_Ｘ をマイコン９０により制御することが可能となっている。マイコン９０はＰＤＰ１の温度情報である検出信号Ｓ_ＴＰに対応する温度と基準値２５℃との差ΔＴ_ｐ を算出し、式（２３）に基づき、基準Ｘアドレス電圧Ｖ_ＸＲに対する補正値ΔＶ_Ｘ を算出する。次にマイコンは基準Ｘアドレス電圧Ｖ_ＸＲと補正値ΔＶ_Ｘ の和を算出し、その結果をＶ_Ｘ 電源部４５に出力する。これにより、最小アドレス電圧Ｖ_ｙｍｉｎ及びオーバライト電圧ＯＷＶ_ｙｍａｘの変動の解消が可能となる。
【０１９３】
以上説明したように、第５参考例によれば、温度変動による駆動マージン変動を解消することができ、図７に示すように駆動マージンの幅が狭い場合においても、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ を略一定としても常にスキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ が適性範囲内となり、駆動マージンの幅が広い場合と同様の良好な表示が実現可能となる。
（ ＶＩＩ ）第６参考例
次に、第６の参考例について図１、図７及び図８に基づいて説明する。
【０１９４】
第６参考例においては、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ を常に適性範囲内とする方法として、最小アドレス電圧Ｖ_ｙｍｉｎとオーバライト電圧ＯＷＶ_ｙｍａｘを変化させる。より具体的には、リセット期間においてＸ電極Ｘ_１ 乃至Ｘ_Ｎ に印加される駆動電圧の波形における自己消去期間Ｔ_ＳＥの長さを制御することにより、オーバライト電圧Ｖ_ｙｍａｘに関しては、低温時には高く、高温時には低くなるように変化させ、最小アドレス電圧Ｖ_ｙｍｉｎに関しても、同様に低温時には高く、高温時には低くなるように変化させる。
【０１９５】
ここで、上述のように、リセット期間は書込パルスによる全面書き込みと自己消去の二つの動作から構成されており、自己消去能力を決定するパラメータの一つのとして自己消去期間Ｔ_ＳＥがある。この自己消去期間Ｔ_ＳＥが長いほど自己消去はより完璧なものとなる。
【０１９６】
今、図８に、自己消去期間Ｔ_ＳＥとオーバライト電圧ＯＷＶ_ｙｍａｘ及び最小アドレス電圧Ｖ_ｙｍｉｎの関係を示す。
【０１９７】
図８に示すように、自己消去期間Ｔ_ＳＥが長いほど自己消去はより完璧なものとなり、その結果として最小アドレス電圧Ｖ_ｙｍｉｎ及びオーバライト電圧ＯＷＶ_ｙｍａｘは低下することがわかる。そこで、自己消去期間Ｔ_ＳＥを制御することにより、温度によるスキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ の適性範囲の変動を補正することが可能であり、具体的には、高温時は自己消去期間Ｔ_ＳＥを長く、低温時には自己消去期間Ｔ_ＳＥを短く制御すればよい。
【０１９８】
今、自己消去期間Ｔ_ＳＥの変化分ΔＴ_ＳＥに対する最小アドレス電圧Ｖ_ｙｍｉｎの変動をΔＶ_ｙｍｉｎ、オーバライト電圧ＯＷＶ_ｙｍａｘの変動をΔＯＷＶ_ｙｍａｘとすると、図８に示す場合、下記式（２５）及び式（２６）が成り立つ。
【０１９９】
ΔＶ_ｙｍｉｎ ＝−０．１７×ΔＴ_ＳＥ …（２５）
ΔＯＷＶ_ｙｍａｘ＝−０．１７×ΔＴ_ＳＥ …（２６）
ここで、ＰＤＰ１の温度変動をΔＴ_ｐ とすると図１６の例では下記式（１９）及び式（２０）が成り立つ。
【０２００】
ΔＶ_ｙｍｉｎ＝０．１７×ΔＴ_ｐ …（１９）
ΔＶ_ｙｍａｘ＝０．１７×ΔＴ_ｐ …（２０）
上記式（２５）と式（１９）及び式（２６）と式（２０）からそれぞれ式（２７）及び式（２８）が導かれる。
【０２０１】
ΔＴ_ＳＥ＝−ΔＴ_ｐ …（２７）
ΔＴ_ＳＥ＝−ΔＴ_ｐ …（２８）
上記式（２７）及び式（２８）は共に、１℃のＰＤＰ１の温度上昇に対して自己消去期間Ｔ_ＳＥを１μｓｅｃ短くすることにより、ＰＤＰ１の温度変動による最小アドレス電圧Ｖ_ｙｍｉｎ及びオーバライト電圧ＯＷＶ_ｙｍａｘの変動を解消することができ、ＰＤＰ１の温度が変動しても、図７に示すように、常に最小アドレス電圧Ｖ_ｙｍｉｎ及びオーバライト電圧ＯＷＶ_ｙｍａｘを略一定にすることができることを示している。
【０２０２】
次に、上記式（２７）及び式（２８）を実現する具体的動作について説明する。
【０２０３】
ＰＤＰ１の表面温度の検出については第１参考例と同様であるので、細部の説明は省略する。
【０２０４】
マイコン９０はＰＤＰ１の温度情報である検出信号Ｓ_ＴＰに対応する温度と、基準値２５℃との差ΔＴ_ｐ を算出し、式（２７）に基づき、基準自己消去期間Ｔ_ＳＥＲ に対する補正値ΔＴ_ＳＥを算出する。
【０２０５】
次にマイコン９０は基準自己消去期間Ｔ_ＳＥＲ と補正値ΔＴ_ＳＥの和を算出し、その結果がＥＰ−ＲＯＭ５０内の駆動波形領域５０Ａの波形選択アドレスに出力され、二種類以上の任意の駆動波形の内、目的の自己消去期間Ｔ_ＳＥを有する波形が選択され、リセット期間におけるＸ電極Ｘ_１ 乃至Ｘ_Ｎ の駆動波形としてパネル駆動部１２に出力され、各ドライバが駆動される。
【０２０６】
以上説明したように、第６参考例によれば、温度変動による駆動マージン変動を解消することができ、駆動マージンの幅が狭い場合においても、スキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ を略一定としても常にスキャンパルスＰ_ＡＹの電圧値Ｖ_ｙ が適性範囲内となり、駆動マージンの幅が広い場合と同様の良好な表示が実現可能となる。
（ ＶＩＩＩ ）第７参考例
次に、第７の参考例について図１及び図９に基づいて説明する。
【０２０７】
第７参考例においては、アドレス期間における異常放電（以下、アドレス強放電という。）により過剰な壁電荷が蓄積し、維持放電において点灯すべき発光セルＣが点滅することを防止するために、アドレス期間と維持放電期間の間に過剰分の壁電荷を除去する役目の中和信号Ｐ_Ｈ が入力される。
【０２０８】
この中和信号Ｐ_Ｈ の波形例を図９に示す。
【０２０９】
中和信号Ｐ_Ｈ において、Ｘ電極Ｘ_１ 乃至Ｘ_Ｎ とＹ電極Ｙ_１ 乃至Ｙ_Ｎ は同電位なのでＸ電極とＹ電極間の放電は起こらない。
【０２１０】
アドレス強放電により生成されたＹ電極Ｙ_１ 乃至Ｙ_Ｎ 上の過剰なイオン（正壁電荷）は、中和信号Ｐ_Ｈ によるアドレス電極Ａ_１ 乃至Ａ_Ｍ 上の電子（負壁電荷）と反応し、微弱放電によってその過剰分の壁電荷が除去される。この時Ｘ電極及びＹ電極の電位をＶ_Ｓ とすると、アドレス電極Ａ_１ 乃至Ａ_Ｍ の電位は１／２Ｖ_Ｓ が２／３Ｖ_Ｓ が最適であることが実験的に確認されている。このアドレス電極Ａ_１ 乃至Ａ_Ｍ の電位が最適値より大きい場合、目的の微弱放電は起こらず、また、適性値より小さい場合は放電が大きくなり、必要以上に壁電荷を除去してしまう。
【０２１１】
この中和信号Ｐ_Ｈ は除去を必要としないセルで作用した場合、適量であった壁電荷を減少させる場合があるので、好ましくは本問題点が顕著に発生する低温時のみ中和信号Ｐ_Ｈ 出力し、それ以外では出力させないことが望ましい。
【０２１２】
次に、第７参考例の具体的動作について説明する。
【０２１３】
ＰＤＰ１の表面温度の検出については第１参考例と同様であるので、細部の説明は省略する。
【０２１４】
マイコン９０に入力された検出信号Ｓ_ＴＰに基づき、ＰＤＰ１の温度が所定の閾値を下回った場合、その旨を示す信号がマイコン９０からＥＰ−ＲＯＭ５０に出力される。この信号はＥＰ−ＲＯＭ５０内の駆動波形領域５０Ａの波形選択アドレスに入り中和信号Ｐ_Ｈ を含む駆動波形が選択され、パネル駆動制御部１２に出力されて中和信号Ｐ_Ｈ を含む駆動パルスが発生する。
【０２１５】
ＰＤＰ１の温度が設定された閾値を上回った場合には、中和信号Ｐ_Ｈ を含まない駆動波形が選択される。ここで、閾値の具体値としては、図１８より、点灯不良セル率が急激に増加する０℃から＋５℃に設定することが望ましい。
【０２１６】
以上説明したように、第７参考例によれば、ＰＤＰ１が所定の低温時において、中和信号Ｐ_Ｈ を含む駆動波形が出力されるので、過剰な壁電荷が中和され、点灯不良の発光セルＣが発生することがない。
（ ＩＸ ）第８参考例
次に、第８の参考例について図１に基づいて説明する。
【０２１７】
第８参考例においては、アドレス期間における異常放電（以下、アドレス強放電という。）により過剰な壁電荷が蓄積し、維持放電において点灯すべき発光セルＣが点滅することを低減するために、当該問題点が顕著に発生する始動時又は全消却画面（何も表示されない画面）が継続したとき等、ＰＤＰ１が低温時に当該ＰＤＰ１が加熱される。
【０２１８】
図１８に示す温度特性の通り、本問題点はＰＤＰ１の温度が低温になる程顕著に発生する。また一般的にＰＤＰは、そのプラズマ放電により発熱するのでパネル温度は発光を行うに従い徐々に上昇していく。よって、本問題点が顕著になる電源投入直後等の低温時において、この不具合が顕著に発生する期間をできるだけ短縮させるために、ＰＤＰ１を加熱し温度を強制的に上昇させる。
【０２１９】
次に、具体的動作を説明する。
【０２２０】
ＰＤＰ１の表面温度の検出については第１参考例と同様であるので、細部の説明は省略する。
【０２２１】
マイコン９０に入力された検出信号Ｓ_ＴＰに基づき、ＰＤＰ１の温度が所定の閾値を下回った場合、その結果をパネル加熱装置９に出力する。これにより、パネル加熱装置９が作動し、ＰＤＰ１を強制加熱する。
【０２２２】
また、ＰＤＰ１の温度が閾値を上回った時点で、マイコン９０からパネル加熱装置９の動作を停止させる信号を出力する。
【０２２３】
以上説明したように、第８参考例によれば、維持放電において点灯すべき発光セルＣが点滅する期間を短くして、発光すべき発光セルＣが点滅するのを低減することができる。
（Ｘ）第１実施例
次に、請求項１、４、７、１０、１３に記載の発明に対応する第１の実施例について図１に基づいて説明する。
【０２２４】
第１実施例によれば、ＰＤＰ１を動作させる周辺環境温度が異常に高い場合、又は、予期せぬ不具合が発生した場合等に、ＰＤＰ１を含むプラズマディスプレイ表示装置Ｓ_１ の温度が異常に上昇し、回路素子の温度定格を超過し、当該回路素子が部品破壊へ至る可能性がある場合に、ＰＤＰ１等の温度が異常モードにつながる可能性のある設定温度に達した場合、ファン等の空冷装置を動作させ空冷処理が行なわれる。
【０２２５】
次に、具体的動作について説明する。
【０２２６】
ＰＤＰ１の表面温度の検出並びにＸ共通ドライバ４及びＹ共通ドライバ７の温度の検出については第１参考例と同様であるので、細部の説明は省略する。
【０２２７】
第１実施例では、この他に、装置内雰囲気温度検出器６０によりプラズマディスプレイ表示装置Ｓ_１ の温度を検出する。ここで、装置内雰囲気温度検出器６０は、装置内の雰囲気温度をできるだけ正確に測定するためにＦＥＴ等の高熱部品からできるだけ離れた位置に配置することが望ましい。
【０２２８】
マイコン９０に入力された検出信号Ｓ_ＴＰ、Ｓ_ＴＸ及びＳ_ＴＹ並びに装置内雰囲気温度検出器６０の検出信号に基づき、各温度情報の内いずれか一つ以上がそれぞれに設定された閾値を上回った場合、その結果に基づき制御回路８１により空冷装置８０が作動する。この動作はマイコン９０に入力された全ての温度情報が閾値を下回るまで継続される。それぞれの閾値としては、検出信号Ｓ_ＴＰに関しては６０℃、検出信号Ｓ_ＴＸ及びＳ_ＴＹに関しては１００℃、装置内雰囲気温度検出器６０の検出信号に関しては５０℃程度が適当である。
【０２２９】
以上説明したように、第１実施例によれば、ＰＤＰ１又は各ドライバの温度がそれぞれの所定値以上に上昇することによる当該ＰＤＰ１又は各ドライバの異常動作を防止することができ、ＰＤＰ１又は各ドライバの信頼性が向上する。
（ ＸＩ ）第２実施例
次に、請求項２、５、８、１１、１３に記載の発明に対応する第２の実施例について図１に基づいて説明する。
【０２３０】
第２実施例によれば、ＰＤＰ１を動作させる周辺環境温度が異常に高い場合、又は、予期せぬ不具合が発生した場合等に、ＰＤＰ１を含むプラズマディスプレイ表示装置Ｓ_１ の温度が異常に上昇し、回路素子の温度定格を超過し、当該回路素子が部品破壊へ至る可能性がある場合に、ＰＤＰ１等の温度が異常モードにつながる可能性のある設定温度に達したとき、ＬＥＤの点滅により使用者にその旨が警告される。
【０２３１】
次に、具体的動作について説明する。
【０２３２】
第２実施例においては、図１に示す装置内雰囲気温度検出器６０により、プラズマディスプレイ表示装置Ｓ_１ が監視されている。装置内雰囲気温度検出器６０の配置については、第１実施例と同様であるので、細部の説明は省略する。
【０２３３】
マイコン９０に入力された検出信号Ｓ_ＴＰ、Ｓ_ＴＸ及びＳ_ＴＹ並びに装置内雰囲気温度検出器６０の検出信号に基づき、各温度情報の内いずれか一つ以上がそれぞれに設定された閾値を上回った場合、マイコン９０は、制御回路７１を作動させ、使用者に対して警告を意味するＬＥＤ７０を点灯させる。この動作は、全ての検出信号に基づく温度情報が閾値を下回るまで継続される。閾値の具体例としては、装置内雰囲気温度検出器６０の場合には、７０℃程度が適当である。
（ ＸＩ ）第３実施例
次に、請求項３、６、９、１２、１３に記載の発明に対応する第３の実施例について図１に基づいて説明する。
【０２３４】
第３実施例によれば、ＰＤＰ１を動作させる周辺環境温度が異常に高い場合、又は、予期せぬ不具合が発生した場合等に、ＰＤＰ１を含むプラズマディスプレイ表示装置Ｓ_１ の温度が異常に上昇し、回路素子の温度定格を超過し、当該回路素子が部品破壊へ至る可能性がある場合に、ＰＤＰ１等の温度が異常モードにつながる可能性のある設定温度に達したとき、プラズマディスプレイ表示装置Ｓ_１ に対する電源供給が禁止される。
【０２３５】
次に、具体的動作について説明する。
【０２３６】
ＰＤＰ１の表面温度の検出、Ｘ共通ドライバ４及びＹ共通ドライバ７の温度の検出並びに、装置内雰囲気温度検出器６０によるプラズマディスプレイ表示装置Ｓ_１ の装置内温度の検出については第１実施例と同様であるので、細部の説明は省略する。
【０２３７】
マイコン９０は、各温度検出器から入力された検出信号に基づき、各温度情報の内いずれか一つ以上がそれぞれに設定された閾値を上回った場合、リレー制御部９１を動作させ、駆動用の高圧線を一時的に断とする。この動作は各温度情報の全てが閾値を下回るまで継続される。それぞれの閾値としては、検出信号Ｓ_ＴＰに関しては９０℃、検出信号Ｓ_ＴＸ及びＳ_ＴＹに関しては１３０℃、装置内雰囲気温度検出器６０からの検出信号に関しては８０℃程度が適当である。
【０２３８】
以上説明したように、第３実施例によれば、ＰＤＰ１等の温度が所定値以上に上昇した場合には、それらの動作を停止することができ、当該所定値以上の温度上昇による異常動作から当該装置等を保護することができる。
【０２４１】
【発明の効果】
請求項１又は５に記載の発明によれば、プラズマディスプレイパネルの温度に基づき、当該温度が所定値以上となった場合に、プラズマディスプレイパネルに対する電力の供給が禁止されるので、プラズマディスプレイパネルの温度が所定値以上に上昇した場合には、プラズマディスプレイパネルの動作を停止することができ、当該所定値以上の温度上昇による異常動作から当該プラズマディスプレイパネルを保護することができる。
【０２４２】
請求項２又は６に記載の発明によれば、プラズマディスプレイパネルの温度及び駆動手段の温度に基づき、プラズマディスプレイパネルの温度が第１所定値以上となった場合、又は駆動手段の温度が第２所定値以上となった場合に、プラズマディスプレイパネル又は駆動手段が冷却されるので、プラズマディスプレイパネル又は駆動手段の温度がそれぞれの所定値以上に上昇することによる当該プラズマディスプレイパネル又は駆動手段の異常動作を防止することができ、プラズマディスプレイパネル又は駆動手段の信頼性が向上する。
【０２４３】
請求項３又は７に記載の発明によれば、プラズマディスプレイパネルの温度及び駆動手段の温度に基づき、プラズマディスプレイパネルの温度が第１所定値以上となった場合、又は駆動手段の温度が第２所定値以上となった場合に、使用者に対し警告が発せられる。
【０２４４】
従って、プラズマディスプレイパネル又は駆動手段の温度がそれぞれの所定値以上に上昇したことを使用者が認識することができ、当該温度上昇によるプラズマディスプレイパネル又は駆動手段の異常動作を未然に防止する処置を取ることができる。
【０２４５】
請求項４又は８に記載の発明によれば、プラズマディスプレイパネルの温度及び駆動手段の温度に基づき、プラズマディスプレイパネルの温度が第１所定値以上となった場合には当該プラズマディスプレイパネルに対する電力の供給が禁止され、駆動手段の温度が第２所定値以上となった場合には当該駆動手段に対する電力の供給が禁止される。
【０２４６】
従って、プラズマディスプレイパネル又は駆動手段の温度がそれぞれの所定値以上に上昇した場合に、プラズマディスプレイパネル又は駆動手段の動作を停止することができ、それぞれの当該所定値以上の温度上昇による異常動作から当該プラズマディスプレイパネル又は駆動手段を保護することができる。
【０２４７】
請求項９に記載の発明によれば、請求項５乃至８のいずれか一項に記載の加熱防止装置により、プラズマディスプレイパネル又は駆動手段の加熱が防止され、表示が行われるので、プラズマディスプレイパネル又は駆動手段の温度が上昇した場合でも、加熱によるプラズマディスプレイパネル又は駆動手段の異常動作又は破損を防止でき、プラズマディスプレイ表示装置の信頼性が向上する。
【図面の簡単な説明】
【図１】実施例及び参考例に係るプラズマディスプレイ表示装置の概要構成ブロック図である。
【図２】維持放電パルス数と輝度の関係を示すグラフ図である。
【図３】維持放電電圧と輝度の関係を示すグラフ図である。
【図４】階調値と輝度の関係を示すグラフ図である。
【図５】第４参考例の処理後のパネル温度に基づくＶ_ｙ の変化の一例を示すグラフ図である。
【図６】第５参考例のＸアドレス電圧と最小アドレス電圧及びオーバライト電圧との関係を示すグラフ図である。
【図７】第５及び第６参考例によるパネル温度とＶ_ｙ 設定値の一例との関係を示すグラフ図である。
【図８】第６参考例の自己消去期間の長さと最小アドレス電圧及びオーバライト電圧との関係を示すグラフ図である。
【図９】第７参考例における中和信号の波形を示す図である。
【図１０】従来技術のＰＤＰの構成（平面図）を示す図である。
【図１１】従来技術のＰＤＰの構成（断面図）を示す図であり、（ａ）は図１０におけるα−α’間の断面図であり、（ｂ）は図１０におけるβ−β’間の断面図である。
【図１２】従来技術のプラズマディスプレイ表示装置の概要構成ブロック図である。
【図１３】従来技術のプラズマディスプレイ表示装置の動作を示すタイミングチャート図である。
【図１４】従来技術の表示データのフレーム構造を示す図である。
【図１５】プラズマディスプレイパネルの温度及び駆動ＦＥＴの温度と輝度の関係を示すグラフ図であり、（ａ）はプラズマディスプレイパネルの温度と輝度の関係を示すグラフ図であり、（ｂ）は駆動ＦＥＴの温度と輝度の関係を示すグラフ図である。
【図１６】プラズマディスプレイパネル温度と適性Ｖ_ｙ 設定範囲との関係を示すグラフ図である。
【図１７】プラズマディスプレイパネル温度とＶ_ｙ 設定可能範囲との関係を示すグラフ図であり、（ａ）はＶ_ｙ 設定可能範囲が広い場合であり、（ｂ）はＶ_ｙ 設定可能範囲が狭い場合である。
【図１８】プラズマディスプレイパネルの温度と点灯不良セル率との関係を示すグラフ図である。
【符号の説明】
１、１００…ＰＤＰ（プラズマディスプレイパネル）
２、１１０…制御回路
３、１１１…アドレスドライバ
４、１１２…Ｘ共通ドライバ
５、８、１０…温度検出器
６、１１３…Ｙスキャンドライバ
７、１１４…Ｙ共通ドライバ
９…パネル加熱装置
１１、１２０…表示データ制御部
１２、１２１…パネル駆動制御部
２０、２２、１３０…フレームメモリ
２１…減算器
３０、１４０…スキャンドライバ制御部
３１、１４１…共通ドライバ制御部
４０…電圧変換部
４１…Ｖ_ａ 電源部
４２…Ｖ_Ｗ 電源部
４３…Ｖ_ＳＣ電源部
４４…Ｖ_ｙ 電源部
４５…Ｖ_Ｘ 電源部
５０…ＥＰ−ＲＯＭ
５０Ａ…駆動波形領域
５０Ｂ…維持パルス数設定領域
６０…装置内雰囲気温度検出器
７０…ＬＥＤ
７１、８１…制御回路
８０…空冷装置
９０…マイコン
９１…リレー制御部
９２…消費電流検出部
１０１…背面ガラス基板
１０２…Ｍ_ｇ Ｏ膜
１０３…誘電体層
１０４…バス電極
１０５…透明電極
１０３…前面ガラス基板
２００、Ｓ_１ …プラズマディスプレイ表示装置
ＩＮ…表示データ入力部
ＩＮ_Ｖ …駆動高圧入力部
ＯＵＴ…基準電圧出力部
ＤＡＴＡ…表示データ
Ａ_１ 、Ａ_２ 、Ａ_３ 、Ａ_４ 、Ａ_５ 、Ａ_６ 、Ａ_７ 、Ａ_８ 、Ａ_９ 、Ａ_Ｍ …アドレス電極
Ｂ…障壁
Ｃ…発光セル
Ｘ_１ 、Ｘ_２ 、Ｘ_３ 、Ｘ_４ 、Ｘ_Ｎ …Ｘ電極
Ｙ_１ 、Ｙ_２ 、Ｙ_３ 、Ｙ_４ 、Ｙ_Ｎ …Ｙ電極
Ｓ_Ａ 、Ｓ_ＹＳ、Ｓ_ＹＣ、Ｓ_Ｘ …制御信号
Ｓ_ＴＰ、Ｓ_ＴＸ、Ｓ_ＴＹ…検出信号
Ｐ_ＡＡ…アドレスパルス
Ｐ_ＡＹ…スキャンパルス
Ｐ_ＡＷ、Ｐ_ＸＷ…書込パルス
Ｐ_ＸＳ、Ｐ_ＹＳ…維持パルス
Ｐ_Ｈ …中和信号
ＣＬＫ…ドットクロック
ＶＳＹＮＣ…垂直同期信号
ＨＳＹＮＣ…水平同期信号
Ｔ_ＳＥ…自己消去期間[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and a device for preventing heating of a plasma display panel, and a plasma display device using the same.
[0002]
2. Description of the Related Art In recent years, in computer displays, televisions, and the like, information to be displayed has been diversified, enlarged, and displayed with high definition. Therefore, display devices such as a plasma display panel, an LCD (Liquid Crystal Display), an electroluminescence, a fluorescent display tube, and a light emitting diode used for these devices are also required to have improved display quality in order to cope with these trends.
[0003]
Among the above display devices, a plasma display panel has been particularly actively developed recently because it has features such as no flicker, easy enlargement of screen, high luminance, and long life.
[0004]
The plasma display panel is roughly divided into a selective discharge (address discharge) for selecting a cell to emit light from among a plurality of light emitting cells constituting a display surface, and a sustain discharge for maintaining light emission in the selected light emitting cell. Is performed using two electrodes, and a three-electrode plasma display panel performs address discharge using a third electrode and performs sustain discharge using the previous two electrodes.
[0005]
On the other hand, a plasma display panel capable of color display is also being developed recently. Among such plasma display panels, among the plasma display panels capable of gradation expression, ultraviolet rays generated by the discharge generated between the above-mentioned electrodes are used. As a result, light is emitted by exciting a phosphor having an emission color corresponding to one of the three primary colors of light formed in each light-emitting cell. There is a drawback in that it is vulnerable to impact due to collision of generated positively charged ions. The two-electrode type plasma display panel described above has a structure in which ions directly collide with the phosphor, and thus has a disadvantage of shortening the life of the phosphor. Therefore, today, a surface discharge type three-electrode plasma display panel having a structure in which ions due to discharge do not collide with a phosphor is becoming popular.
[0006]
As a type of the above-mentioned surface discharge type three-electrode plasma display panel, a third electrode for performing an address discharge is disposed on a substrate on which first and second electrodes for performing a sustain discharge are disposed. And one in which the third electrode is disposed on another substrate facing the substrate on which the first and second electrodes are disposed. Further, in a plasma display panel having the above-described first to third electrodes on the same substrate, a case where a third electrode is disposed over two electrodes that perform sustain discharge, and a case where a third electrode is disposed below the two electrodes. There is a case where a third electrode is provided. Further, a transmissive plasma display panel that transmits light (visible light) emitted from a phosphor through the phosphor and emits light to the outside, and a reflective plasma display panel that guides the emitted light to the outside as reflected light from the phosphor are provided. is there.
[0007]
Here, a light emitting cell which performs discharge is spatially disconnected from an adjacent light emitting cell by a barrier (also referred to as a rib or a barrier). When the plasma display panel is classified according to the barrier structure, the barrier is provided on all sides so as to surround the light emitting cell, and the barrier provided in the light emitting cell completely seals the gas used for light emission. In some cases, the coupling between adjacent light emitting cells may be cut off by optimizing the gap (distance) between the electrodes in a direction orthogonal to the one direction.
[0008]
[Prior art]
Here, among the above-mentioned three-electrode type plasma display panels, a surface discharge type three-electrode AC (alternating current) type plasma display panel generally used in the related art will be described with reference to FIGS. In the following description, a third electrode for performing an address discharge is disposed in a direction perpendicular to the two electrodes on a substrate facing a substrate on which two electrodes for performing a sustain discharge are disposed in parallel. Further, the barrier is arranged only in a direction perpendicular to the first and second electrodes for performing the sustain discharge and in a direction parallel to the third electrode for performing the address discharge, and a part of the first and second electrodes. Will be described with reference to a reflective surface discharge three-electrode AC plasma display panel (hereinafter, simply referred to as a PDP (Plasma Display Panel)) composed of transparent electrodes.
[0009]
First, a schematic structure of a conventional PDP will be described with reference to FIGS.
[0010]
First, a plan view of a conventional PDP 100 is shown in FIG.
[0011]
In FIG. 10, PDP 100 has an address electrode A for performing an address discharge.₁Or A_MAnd an X electrode X for performing sustain discharge₁Or X_NAnd Y electrode Y₁Or Y_NIt has. Here, X electrode X₁Or X_NAre respectively connected to a common electrode, and Y electrodes Y₁Or Y_NAre independent of each other. The light emitting cell C has any one of the three colors (red (hereinafter, referred to as R), green (hereinafter, referred to as G), and blue (hereinafter, referred to as B) corresponding to the three primary colors of light. The phosphor corresponding to one color is applied, and the Y electrode Y₁Or Y_NAre separated by a barrier B. Further, the phosphors of the same color are applied inside the two adjacent barriers B, and the PDP 100 as a whole is provided with phosphors in the form of stripes in the order of R, G, and B.
[0012]
Here, the address electrode A of the light emitting cell C₁Or A_MThe direction is divided between the X electrode and the Y electrode between the adjacent light emitting cells C (for example, the X electrode X₂And Y electrode Y₁The connection between adjacent light emitting cells C is cut off by optimizing the gap (distance) between the light emitting cells C.
[0013]
In PDP 100 having the above-described configuration, address discharge is caused by address electrode A.₁Or A_MAnd Y electrode Y₁Or Y_N, And the sustain discharge is performed between the corresponding adjacent X electrodes X₁Or X_NAnd Y electrode Y₁Or Y_N(X electrode X₁And Y electrode Y₁, X electrode X₂And Y electrode Y₂, Etc.).
[0014]
Next, a cross-sectional configuration of the PDP 100 will be described with reference to FIG. In FIG. 11, FIG. 11A shows a part (address electrode A) of the section taken along the line α-α ′ in FIG.₄Or A₆FIG. 11B shows a part (Y electrode Y) of a section taken along the line β-β ′ in FIG.₁, X electrode X₂And Y electrode Y₂).
[0015]
As shown in FIG. 11, PDP 100 is a reflection type PDP, and address electrodes A₁Or A_M, X electrode X as sustain electrode₁Or X_NAnd Y electrode Y₁Or Y_N, The light-emitting cell C and the barrier B are formed between the rear glass substrate 101 and the front glass substrate 106, and as shown in FIG. Address electrode A₁Or A_MA barrier B for dividing each light emitting cell C, and each address electrode A₁Or A_MAnd a phosphor F which is formed so as to cover and emits light when excited by ultraviolet rays emitted by the address discharge and the sustain discharge, and has a light emission color (R, G or B) corresponding to each light emitting cell C; An MgO layer 102 as a protective layer for protecting the discharge surface from positive ions emitted by the address discharge and the sustain discharge, and a dielectric layer made of glass or the like that forms a discharge surface while insulating between each X electrode and each Y electrode. 103 and X electrode X₁Or X_NAnd the Y electrode Y₁Or Y_NAnd a front glass substrate 106 constituting a display surface. Here, back glass substrate 101 and front glass substrate 106 are arranged such that the top of barrier B and MgO layer 102 are in close contact with each other.
[0016]
In addition, as shown in FIG.₁Or X_NAnd Y electrode Y₁Or Y_NAre composed of a transparent electrode 104 and a bus electrode 105, respectively. Here, the transparent electrode 104 is formed of ITO (Indium Titanium Oxide, a transparent conductive film mainly composed of oxide indium) to transmit light emitted from the phosphor F, and the bus electrode 105 is formed by electric resistance. It is made of low-resistance Cu (copper) or Cr (chromium) to prevent a voltage drop.
[0017]
In the above-described configuration, light emitted from the phosphor F is transmitted through the transparent electrode 105 and the front glass substrate 106 as reflected light and emitted from the display surface.
[0018]
Here, in display data for performing display using the conventional PDP 100, one frame of data to be displayed is composed of a plurality of sub-frames (screens), and the sub-frames include a reset period and an address, respectively. The period is divided into a period and a sustain discharge period.
[0019]
The reset period is a period for resetting all the light emitting cells C of the PDP 100 and removing unnecessary charging.
[0020]
In the address period, the address electrodes A corresponding to the light emitting cells C to emit light based on the data to be displayed.₁Or A_MAnd Y electrode Y₁Y_NIn this period, an address discharge (selective discharge, see FIG. 11B) is generated by applying an address pulse and a scan pulse along an address line.
[0021]
Further, during the sustain discharge period, the X electrode X₁Or X_NAnd Y electrode Y₁Or Y_NIs a period in which a sustain pulse is applied to further emit light from the light emitting cell C that has been made to emit light by the address discharge. At this time, the sustain pulse causes a sustain discharge shown in FIG. 11B, and the light emitting cell C emits light. Here, the more the sustain pulse, the higher (brighter) the luminance of the light emitting cell.
[0022]
Next, a configuration of a conventional plasma display device including the PDP 100 will be described with reference to FIG.
[0023]
In the plasma display device 200 shown in FIG.₁Or A_MAre connected to an address driver 111 one by one, and the address driver 111 generates an address pulse P at the time of address discharge._AWEtc. are applied. The Y electrode Y₁Or Y_NAre individually connected to the Y scan driver 113. The Y scan driver 113 is connected to the Y common driver 114, and outputs a scan pulse P during an address discharge._AYAre generated from the Y scan driver 113 and sustain pulses P during the sustain discharge period._YSAre generated by the Y common driver 114, and the Y electrode Y₁Or Y_NIs applied. On the other hand, X electrode X₁Or X_NAre connected and taken out in common over all display lines of the PDP 100.
[0024]
The X common driver 112 outputs the write pulse P during the reset period._XW, Sustain pulse P during sustain discharge period_XSAnd so on. These drivers are controlled by the control circuit 110.
[0025]
The control circuit 110 includes a display data control unit 120 including a frame memory 130 for storing one frame of display data DATA, a scan driver control unit 140 for controlling each driver, and a panel drive including a common driver control unit 141. The control unit 121 is configured to output a control signal for controlling each driver based on a dot clock CLK, a synchronization signal HSYNC, VSYNC, and display data DATA input from outside.
[0026]
Next, based on the timing chart shown in FIG. 13 and FIG. 12, an operation of the plasma display device 200 in a sub-frame period corresponding to one sub-frame will be described. FIG. 13 shows the generation timing of each pulse in one subframe period.
[0027]
As shown in FIG. 13, first, in the reset period (consisting of the entire writing period and the self-erasing period), all the Y electrodes Y₁Or Y_NIs set to the 0V level, and all the X electrodes X₁Or X_NWrite pulse P_XW(Approximately 330 V, 10 μsec). This write pulse P_XWIn synchronization with all address electrodes A₁Or A_MWrite pulse P_AWIs applied. This write pulse P_XWAnd P_AWWith all X electrodes X₁Or X_NAnd address electrode A₁Or A_MDuring this period (all light emitting cells C), discharge is performed regardless of the previous display state. Then, the write pulse P_XWAnd P_AWAfter discharge by all X electrodes X₁Or X_NAnd address electrode A₁Or A_MBecomes the 0V level, and the voltage of the wall charge itself exceeds the discharge start voltage in all the light emitting cells C, and the discharge is started. In this discharge, there is no potential difference between the electrodes, so that no wall charge is formed, and the space charge is self-neutralized and terminated, which is a so-called self-extinguishing discharge. At this time, the X electrode X₁Or X_NWrite pulse P at_XWX electrode X in the next address period after the application of₁Or X_NThe period up to the application of the voltage to the memory is referred to as a self-erasing period T_SEAnd
[0028]
By this self-extinguishing discharge, all the light emitting cells C are brought into a uniform potential state without wall charges, and reset is performed. In this reset period, all the light emitting cells C have the same potential state regardless of the lighting state in the immediately preceding subframe period, so that the address discharge can be stably performed in the address period next to the reset period.
[0029]
Next, in the address period, an address discharge for selecting a light emitting cell C to emit light based on the subframe data is performed. The address discharge is divided into a priming address discharge as a light emitting cell designating discharge and a main address discharge as a wall charge accumulation discharge.
[0030]
That is, the priming address discharge applies the address pulse P to the address electrode corresponding to the light emitting cell C to emit light._AAIs applied, and in parallel with this, the Y electrode Y corresponding to the light emitting cell C to be caused to emit light is applied to the Y electrode Y.₁Scan pulses P in time division (along the address line)_AYIs applied and the address pulse P_AAAnd scan pulse P_AYIs performed by
[0031]
At this time, one address pulse P_AAIn the timing of FIG. 13, the address pulse P is applied to all the address electrodes corresponding to the light emitting cells C specified by the subframe data corresponding to the corresponding subframe in the timing chart shown in FIG._AAIs applied. Thus, the priming address discharge occurs simultaneously in the necessary light emitting cells C among the light emitting cells C corresponding to one Y electrode. Thereafter, this operation is performed by the scan pulse P applied to each Y electrode._AYIs repeated in the light emitting cell C corresponding to the Y electrode at the timing shown in FIG.
[0032]
More specifically, the priming address discharge and the main address discharge will be described first.₁) Is the scan pulse P of the -VY level (about -150 V)._AYIs applied, and at the same time, the address electrode A₁Or A_MOf the light emitting cells C to emit light, the voltage V_a(About 50V) address pulse P_AAIs applied. At this time, all X electrodes X₁Or X_NIs a predetermined X address voltage (V in FIG. 13)_XIndicated by ) Is maintained. Then, the Y electrode Y₁And address electrode A₁A priming address discharge is generated between the X electrodes X and X₁And Y electrode Y₁A main address discharge as a wall charge accumulation discharge is generated between these two. By the priming address discharge and the main address discharge, an X electrode and a Y electrode (X electrode X₁And Y electrode Y₁) Are accumulated on the MgO film 102 (see reference numeral 102 in FIG. 11) in such an amount that a sustain discharge in the next sustain discharge period is possible.
[0033]
The above address discharge is caused by the address pulse P_AYAt the timing of (1), data is sequentially written to all the Y electrodes, and data is written to the light emitting cell C corresponding to the subframe data.
[0034]
Finally, in the sustain discharge period, the sustain pulse P is alternately applied to all the X electrodes and the Y electrodes so that the light emitting cells C designated in the address period further emit light._XSAnd P_YS(Approximately 180 V) is applied, sustain discharge is performed in the specified (light-accumulated) light-emitting cell C exceeding a threshold, and an image with a luminance corresponding to the sub-frame data is displayed. Here, as described above, the sustain pulse P_XSAnd P_YSThe greater the number is, the higher the light emission luminance in the subframe period is.
[0035]
Next, a case where a multi-gradation expression is performed in the plasma display device 200 including the above-described PDP 100 will be described as an example where a 256-gradation expression is performed.
[0036]
In the case of expressing 256 gradations, one frame in the display data DATA is time-divided into eight sub-frames (SF1 to SF8) as shown in FIG. Each subframe has a reset period, an address period, and a sustain discharge period, and the reset period and the address period have the same length. Further, the length of the sustain discharge period has a ratio of 1: 2: 4: 8: 16: 32: 64: 128. Therefore, by selecting a subfield to be turned on, a difference in luminance of 256 gradations from 0 to 255 can be displayed.
[0037]
More specifically, for example, when expressing 7/256 gradations, since 7 (gradation) = 1 (gradation) +2 (gradation) +4 (gradation), subframe 1 In addition, light emission is set so as to emit light only for a time corresponding to subframe 3 and light emission is not performed in other subframes. Also, for example, when expressing 20/256 gradations, similarly, since 20 (gradation) = 16 (gradation) +4 (gradation), the time corresponding to sub-frame 3 and sub-frame 5 It is set to emit light only. In each sub-frame, the brightness corresponding to the sub-frame is determined by the length of the sustain discharge period, that is, the number of sustain pulses.
[0038]
Further, an example of actual time distribution in one frame is as follows.
[0039]
For example, if the rewriting of the screen is 60 Hz, one frame is 16.6 ms (1/60 Hz). Assuming that the number of sustain discharge cycles (also referred to as a sustain cycle) in one frame is 510, the number of sustain discharge cycles in each subframe is 2 for SF1, 4 for SF2, 8 for SF3, and 8 for SF4. 16 cycles, SF5 has 32 cycles, SF6 has 64 cycles, SF7 has 128 cycles, and SF8 has 256 cycles. Assuming that the sustain cycle time is 8 μs, the total in one frame is 4.08 ms. Eight reset periods and address periods are allocated in the remaining about 12 ms. Here, the reset period of each subfield is 50 μs. Further, since the time required for the address cycle (scan per line) is 3 μs, in the case of the PDP 100 having 480 display lines (Y electrodes) in the vertical direction, the time is 1.44 ms (3 × 480). Need.
[0040]
[Problems to be solved by the invention]
However, when the above-described PDP 100 is operated, since the operation itself is performed by gas discharge under a high voltage, as the operation is continued, the PDP 100 and each driver that operates the PDP 100 due to a temperature rise will be described below. Various problems have arisen.
[0041]
First, as the temperature rises, a change in the discharge characteristics of the PDP 100 itself due to a rise in temperature and a change in on-resistance with respect to the temperature of a driving element (FET (Field Effect Transistor) or the like) constituting each driver increase the temperature. However, there is a problem that the brightness of the PDP 100 is reduced even though the voltage applied to the light emitting cell C, the number of sustain pulses, and the like are not changed.
[0042]
To explain this problem in more detail, the relationship between the surface temperature and the brightness of the PDP 100 changes as shown in FIG. 15A, and the relationship between the driving element and the brightness changes as shown in FIG. In both cases, the brightness decreases as the temperature increases.
[0043]
Next, as a second problem, the scan pulse P_AY(P in FIG. 13_AYVoltage)_yHowever, there is a problem that the allowable range (hereinafter, referred to as a drive voltage margin) that can be applied changes with the temperature rise of the PDP 100.
[0044]
More specifically, in the address period, the scan pulse P which is the minimum necessary for all the selected light emitting cells C to perform the address discharge normally is provided._AYVoltage V_yIs the minimum address voltage V_yminThen, the minimum address voltage V_yminIncreases as the temperature of PDP 100 increases, as shown in FIG. On the other hand, a phenomenon in which the unselected light emitting cells C are erroneously turned on is called overwriting._AYVoltage V_yIs the overwrite voltage OWV_ymaxThen the overwrite voltage OWV_ymaxAlso, as shown in FIG. 16, the temperature increases as the temperature of PDP 100 increases.
[0045]
At this time, as shown in FIG._yIf the settable range is sufficiently wide, V_ySince the set value is within the settable range, there is no problem in display quality, but as shown in FIG._yWhen the settable range is narrow, writing is defective at high temperatures, and overwriting occurs at low temperatures, resulting in a large defect in display quality.
[0046]
Further, as a third problem, in driving the PDP 100, when the address discharge is performed on the light emitting cell C to be made to emit light and then the sustain discharge is performed, the amount of wall charges formed by the address discharge is more than necessary. However, there is a problem that normal sustain discharge cannot be performed. In this case, a problem occurs that the selected light emitting cell C blinks. This problem is caused by the fact that the address discharge during the address period is unnecessarily strong, and when the amount of wall charges formed by the address discharge is unnecessarily large, the X electrode X₁Or X_NAnd Y electrode Y₁Or Y_NSustain discharge to be performed at the address electrode A₁Or A_MAnd Y electrode Y₁Or Y_NIt is a phenomenon that goes by.
[0047]
It has been found that this problem does not depend on the voltage value of each electrode for performing the address discharge, but greatly depends on the type of the phosphor F and the temperature of the PDP 100.
[0048]
FIG. 18 shows the relationship between the ratio of the flashing defective light emitting cells C due to excessive address discharge and the temperature of the PDP 100. As shown in FIG. 18, it can be seen that as the temperature of the PDP 100 decreases, the number of light emitting cells in which a failure occurs increases.
[0049]
Finally, as a fourth problem, when the ambient temperature around which the PDP 100 is operated is abnormally high, or when an unexpected trouble occurs, the temperature of the PDP 100 or its driving means rises abnormally, There is a danger that the temperature rating of the component will be exceeded, and at this time, there is a problem that the circuit element may lead to component destruction.
[0050]
Therefore, the present invention has been made mainly in view of the fourth problem, and an object of the present invention is to protect a plasma display device including the PDP 100 from a rise in the temperature of the PDP 100 or a driver due to driving. And a plasma display panel using the same.
[0053]
[Means for Solving the Problems]
No.Claim to solve problem 41In the invention described in (1), a detecting step of detecting the temperature of the plasma display panel, and a prohibiting step of, based on the detected temperature, prohibiting supply of power to the plasma display panel when the temperature is equal to or higher than a predetermined value And is provided.
[0054]
In order to solve the fourth problem, the claims2The invention described above includes a first detection step of detecting a temperature of the plasma display panel, a second detection step of detecting a temperature of a driving unit for driving the plasma display panel, and the detected temperature of the plasma display panel and the temperature of the plasma display panel. When the temperature of the plasma display panel is equal to or higher than a first predetermined value, the plasma display panel is cooled based on the temperature of the driving unit, and when the temperature of the driving unit is equal to or higher than a second predetermined value. And a cooling step of cooling the driving means.
[0055]
Further, in order to solve the fourth problem, the claims3The invention described in (1) includes a first detection step of detecting the temperature of the plasma display panel, a second detection step of detecting the temperature of a driving unit for driving the plasma display panel, and the detected temperature and temperature of the plasma display panel. A warning step of issuing a warning when the temperature of the plasma display panel is equal to or higher than a first predetermined value, or when the temperature of the driving means is equal to or higher than a second predetermined value, based on the temperature of the driving unit; It comprises.
[0056]
In order to solve the fourth problem, the claims4The invention described in (1) includes a first detection step of detecting the temperature of the plasma display panel, a second detection step of detecting the temperature of a driving unit for driving the plasma display panel, and the detected temperature and temperature of the plasma display panel. When the temperature of the plasma display panel is equal to or higher than a first predetermined value based on the temperature of the driving unit, the supply of power to the plasma display panel is prohibited, and the temperature of the driving unit is equal to or higher than a second predetermined value. And a prohibition step of prohibiting the supply of power to the driving means when the power supply is turned off.
[0059]
In order to solve the fourth problem, the claims5The invention described in the above, detecting the temperature of the plasma display panel, a detecting means such as a thermocouple to output a detection signal, based on the detection signal, when the temperature is equal to or more than a predetermined value, the plasma display panel Prohibiting means such as a relay for prohibiting power supply.
[0060]
Furthermore, in order to solve the fourth problem, the claims6The invention described in (1) detects a temperature of a plasma display panel, detects a temperature of a driving means for driving the plasma display panel, a first detection means such as a thermocouple for outputting a first detection signal, and outputs a second detection signal. A second detection unit such as a thermocouple that outputs a signal, and based on the first detection signal and the second detection signal, when the temperature of the plasma display panel becomes equal to or higher than a first predetermined value, the plasma display panel is cooled. And a cooling means such as an air cooling device for cooling the driving means when the temperature of the driving means is equal to or higher than a second predetermined value.
[0061]
In order to solve the fourth problem, the claims7The invention described in (1) detects a temperature of a plasma display panel, detects a temperature of a driving means for driving the plasma display panel, a first detection means such as a thermocouple for outputting a first detection signal, and outputs a second detection signal. Based on the first detection signal and the second detection signal, when the temperature of the plasma display panel is equal to or higher than a first predetermined value, or when the temperature of the driving unit is And a warning means such as an LED for issuing a warning when the value becomes equal to or more than the second predetermined value.
[0062]
Furthermore, in order to solve the fourth problem, the claims8The invention described in (1) detects a temperature of a plasma display panel, detects first temperature such as a thermocouple that outputs a first detection signal, and a temperature of a driving unit that drives the plasma display panel, and generates a second detection signal. And a second detection unit such as a thermocouple that outputs a power to the plasma display panel based on the first detection signal and the second detection signal when the temperature of the plasma display panel becomes equal to or higher than a first predetermined value. And a prohibiting unit such as a relay for prohibiting the supply of power to the driving unit when the temperature of the driving unit becomes equal to or higher than a second predetermined value.
[0063]
Claims9The invention described in claim5Or8And a control unit such as a display data control unit that controls a driving unit that drives the plasma display panel based on display data input from the outside, and Under the control of the control unit, the control unit includes the driving unit such as a driver for driving the plasma display panel, and the plasma display panel driven by the driving unit and performing the display.
[0070]
[Action]
Claim1According to the invention described in (1), in the detecting step, the temperature of the plasma display panel is detected.
[0071]
Then, in the prohibition step, based on the detected temperature of the plasma display panel, when the temperature exceeds a predetermined value, the supply of power to the plasma display panel is prohibited.
[0072]
Therefore, when the temperature of the plasma display panel rises above a predetermined value, the operation of the plasma display panel can be stopped.
[0073]
Claim2According to the invention described in (1), in the first detection step, the temperature of the plasma display panel is detected.
[0074]
In parallel with this, in the second detection step, the temperature of the driving means is detected.
[0075]
Then, in the cooling step, based on the detected temperature of the plasma display panel and the temperature of the driving unit, when the temperature of the plasma display panel is equal to or higher than the first predetermined value, the plasma display panel is cooled, and the temperature of the driving unit is reduced. When it becomes equal to or more than the second predetermined value, the driving means is cooled.
[0076]
Therefore, it is possible to prevent abnormal operation of the plasma display panel or the driving unit due to the temperature of the plasma display panel or the driving unit rising to a predetermined value or more.
[0077]
Claim3According to the invention described in (1), in the first detection step, the temperature of the plasma display panel is detected.
[0078]
In parallel with this, in the second detection step, the temperature of the driving means is detected.
[0079]
Then, in the warning step, based on the detected temperature of the plasma display panel and the temperature of the driving unit, when the temperature of the plasma display panel is equal to or higher than the first predetermined value, or when the temperature of the driving unit is equal to or higher than the second predetermined value. If a warning is issued.
[0080]
Therefore, the user can recognize that the temperature of the plasma display panel or the driving unit has risen to the predetermined value or more.
[0081]
Claim4According to the invention described in (1), in the first detection step, the temperature of the plasma display panel is detected.
[0082]
In parallel with this, in the second detection step, the temperature of the driving means is detected.
[0083]
Then, in the prohibition step, based on the detected temperature of the plasma display panel and the temperature of the driving unit, when the temperature of the plasma display panel becomes equal to or higher than a first predetermined value, the supply of power to the plasma display panel is prohibited, When the temperature of the driving unit becomes equal to or higher than the second predetermined value, supply of power to the driving unit is prohibited.
[0084]
Therefore, when the temperature of the plasma display panel or the driving unit rises to the predetermined value or more, the operation of the plasma display panel or the driving unit can be stopped.
[0091]
Claim5According to the invention described in (1), the detecting means detects the temperature of the plasma display panel and outputs a detection signal.
[0092]
Then, based on the detection signal, the prohibiting means prohibits the supply of power to the plasma display panel when the temperature exceeds a predetermined value.
[0093]
Therefore, when the temperature of the plasma display panel rises above a predetermined value, the operation of the plasma display panel can be stopped.
[0094]
Claim6According to the invention described in (1), the first detection means detects the temperature of the plasma display panel and outputs a first detection signal.
[0095]
In parallel with this, the second detecting means detects the temperature of the driving means for driving the plasma display panel, and outputs a second detection signal.
[0096]
The cooling means cools the plasma display panel based on the first detection signal and the second detection signal when the temperature of the plasma display panel becomes equal to or higher than a first predetermined value, and reduces the temperature of the driving means to a second predetermined value. If it exceeds the value, the driving means is cooled.
[0097]
Therefore, it is possible to prevent abnormal operation of the plasma display panel or the driving unit due to the temperature of the plasma display panel or the driving unit rising to a predetermined value or more.
[0098]
Claim7According to the invention described in (1), the first detection means detects the temperature of the plasma display panel and outputs a first detection signal.
[0099]
In parallel with this, the second detecting means detects the temperature of the driving means for driving the plasma display panel, and outputs a second detection signal.
[0100]
Then, based on the first detection signal and the second detection signal, the warning means is provided when the temperature of the plasma display panel becomes equal to or higher than the first predetermined value or when the temperature of the driving means becomes equal to or higher than the second predetermined value. Give a warning.
[0101]
Therefore, the user can recognize that the temperature of the plasma display panel or the driving unit has risen to the predetermined value or more.
[0102]
Claim8According to the invention described in (1), the first detection means detects the temperature of the plasma display panel and outputs a first detection signal.
[0103]
In parallel with this, the second detecting means detects the temperature of the driving means for driving the plasma display panel, and outputs a second detection signal.
[0104]
The prohibiting means prohibits the supply of power to the plasma display panel based on the first detection signal and the second detection signal when the temperature of the plasma display panel becomes equal to or higher than the first predetermined value, and When the temperature becomes equal to or higher than the second predetermined value, the supply of power to the driving unit is prohibited.
[0105]
Therefore, when the temperature of the plasma display panel or the driving unit rises to the predetermined value or more, the operation of the plasma display panel or the driving unit can be stopped.
[0106]
Claim9According to the invention described in (1), the claims5Or8The device for preventing heating of a plasma display panel according to any one of the above, prevents the plasma display panel or the driving means from being heated by the respective actions.
[0107]
On the other hand, the control means controls the driving means for driving the plasma display panel based on display data input from the outside.
[0108]
The driving unit drives the plasma display panel under the control of the control unit.
[0109]
The plasma display panel is driven by driving means to perform display.
[0110]
Therefore, even when the temperature of the plasma display panel or the driving unit increases, abnormal operation or breakage of the plasma display panel or the driving unit due to heating can be prevented.
[0111]
【Example】
Next, preferred embodiments and reference examples of the present invention will be described with reference to FIGS.
(I) Device configuration
First, the configuration of the plasma display device according to each of the following examples and reference examples will be described with reference to FIG.
[0112]
As shown in FIG. 1, the plasma display device S according to the embodiment and the reference example₁Is a PDP 1 having the above configuration and a control signal S from a control circuit 2 described later._ABased on the address electrode A₁Or A_MAddress pulse P_AAAnd write pulse P_AWAnd a control signal S from a control circuit 2 described later._XBased on the X electrode X₁Or X_NWrite pulse P_XWAnd sustain pulse P_XSAnd a temperature of the X common driver 4 as a driving means for applying the detection signal S._TXAnd a temperature detector 5 such as a thermocouple as a second detection means (detection means) for outputting a control signal S from a control circuit 2 described later._YSBased on the Y electrode Y₁Or Y_NScan pulse P_AYScan driver 6 as a driving unit for applying a control signal, and a control signal S from a control circuit 2 described later._YC, The Y electrode Y via the Y scan driver 6₁Or Y_NSustain pulse P_YSAnd a temperature of the Y common driver 7 as a driving means for applying the detection signal S._TYA temperature detector 8 such as a thermocouple as a second detecting means (detecting means) for outputting the PDP 1, a panel heating device 9 as a heating means such as a heater for heating the PDP 1 under the control of a microcomputer 90 described later, The temperature is detected and the detection signal S_TPAnd a predetermined signal (dot clock CLK, display data DATA, vertical synchronizing signal VSYNC, horizontal synchronizing signal HSYNC, etc.) and a microcomputer 90 to be described later. A control circuit 2 as control means for controlling the driving of the PDP 1 on the basis of_VUnder the control of a microcomputer 90 to be described later, a voltage converter 40 for voltage-converting the high-voltage power inputted from the PDP 1 for each pulse applied to the PDP 1, and a waveform of each pulse applied to the PDP 1 is stored in advance, Under the control of 90, an EP-ROM (Erasable and Programmable-Read Only Memory) 50 having a drive waveform area 50A for outputting a desired pulse waveform and a sustain pulse number setting area 50B, and an apparatus for detecting the temperature in the apparatus An internal atmosphere temperature detector 60, a control circuit 71 for controlling display of an LED 70 as a warning unit under the control of a microcomputer 90 described later, and an operation of an air cooling device 80 as a cooling unit under the control of the microcomputer 90 described later The voltage converter 40 and the control circuit 81 are controlled by a control circuit 81 that controls the A relay control section 91 as prohibiting means for prohibiting the application of high voltage to the road 2, plasma display device S₁A power consumption detection unit 92 for detecting the entire power consumption, and a plasma display device S₁It comprises a brightness control means for controlling the whole, a voltage control means, and a microcomputer 90 as a signal control means. In the above configuration, each driver is provided with the control signal S_A, S_YS, S_YCAnd S_XAt the same time, high-voltage power for driving each driver is also applied. The display data DATA is externally input via the display data input unit IN.
[0113]
Further, the control circuit 2 corresponds to one frame in the display data DATA based on the control of the microcomputer 90 and the dot clock CLK and the display data DATA (previously divided into data corresponding to R, G and B). Time data is divided into a plurality of sub-frame data, and a control signal S based on the sub-frame data is_AAnd a control signal S based on the control of the microcomputer 90 and the vertical synchronization signal VSYNC and the horizontal synchronization signal HSYNC._X, S_YS, S_YCAnd a panel drive control unit 12 that outputs the same. Here, the display data control unit 11 and the panel drive control unit 12 exchange necessary data with each other.
[0114]
Further, the display data control unit 11 includes frame memories 20 and 22 for temporarily storing the input display data DATA frame by frame, and a subtracter for correcting the number of gradations in the display data DATA under the control of the microcomputer 90. 21.
[0115]
The panel drive control unit 12 controls the scan pulse P included in the sub-frame data corrected by the display data control unit 11._AYAnd a control signal S based on the vertical synchronization signal VSYNC and the horizontal synchronization signal HSYNC._YSAnd a sustain pulse P included in the sub-frame data corrected by the display data control unit 11._XS, P_YS, And the control signal S based on the vertical synchronization signal VSYNC and the horizontal synchronization signal HSYNC._YCAnd S_XAnd a common driver control unit 31 that outputs the same.
[0116]
Further, the voltage conversion unit 40 includes a driving high voltage input unit IN._VAnd write pulse P based on high-voltage power input from an external high-voltage generator (not shown)_AWAnd address pulse P_AAAddress electrode A to generate₁Or A_MV that generates high-voltage power supplied to_aPower supply section 41 and high-voltage input section for driving IN_VPulse P based on the high-voltage power input from_XWX electrode X to generate₁Or X_NV that generates high-voltage power supplied to_WPower supply unit 42 and high-voltage input unit for driving IN_VY electrode Y for main address discharge (wall charge accumulation discharge) during the address period based on the high voltage power input from₁Or Y_NV that generates high-voltage power supplied to_SCPower supply unit 43 and driving high voltage input unit IN_VScan pulse P in the address period under the control of microcomputer 90 based on the high voltage power input from_AYY electrode Y₁Or Y_NV that generates high-voltage power supplied to_yPower supply unit 44 and high voltage input unit for driving IN_VUnder the control of the microcomputer 90 based on the high-voltage power input from the X electrode X for the main address discharge (wall charge accumulation discharge) during the address period.₁Or X_NPower (X address voltage V_XV)_XAnd a power supply unit 45.
[0117]
Further, the microcomputer 90 is connected to a sustain discharge voltage (sustain pulse voltage) reference voltage output section OUT, thereby controlling an external high voltage generator (not shown) for generating the sustain discharge voltage for driving. High voltage input section IN_VIt is possible to control the voltage of the electric power input from the power supply and control the sustain discharge voltage.
[0118]
The plasma display device S of each embodiment and the reference example having the above configuration₁Will be described below for each embodiment and reference example.
( II ) First reference example
First, the operation of the first reference example will be described with reference to FIGS.
[0119]
In the first reference example, the surface temperature of the PDP 1 is detected by the temperature detector 10, and the temperatures of the X common driver 4 and the Y common driver 7 are detected by the temperature detectors 5 and 8, respectively. Then, detection signals S output from the respective temperature detectors_TP, S_TXAnd S_TY, The brightness of the PDP 1 lowered by the temperature rise of the PDP 1 itself or each common driver is corrected. More specifically, the sustain pulse P_XSAnd P_YSIs corrected.
[0120]
First, FIG. 2 shows the relationship between the number of sustain pulses and luminance. In FIG. 2, one sustain pulse P_XSAnd one sustain pulse P_YSAre counted as a set, and the number of sustain pulses is counted.
[0121]
As shown in FIG. 2, the number of sustain pulses is proportional to the luminance. In this example, adjustment of 0.4 candela / piece, that is, 0.4 candela per one sustain pulse (when one sustain pulse is added, , The brightness becomes 0.4 candela brighter).
[0122]
More specifically, the brightness is B and the number of pulses is P₁Then, the following equation (1) holds.
[0123]
B = 0.4 × P₁                              … (1)
In the example of the luminance versus panel temperature characteristic in FIG. 15A, the luminance is -0.33 candela / ° C. It shows that it decreases. According to the relationship shown in FIG._pThen, the following equation (2) holds.
[0124]
B = −0.33 × ΔT_p                      … (2)
The following equation (3) is derived from the equations (1) and (2).
[0125]
0.4 × P₁= −0.33 × ΔT_p
P₁= −0.825 × ΔT_p          … (3)
Equation (3) indicates that the number of sustain pulses may be increased by 0.825 as a luminance correction for a panel temperature rise of 1 ° C.
[0126]
Similarly, in the example of the luminance vs. FET (driver) temperature characteristic in FIG. 15B, it is −0.33 candela / ° C., similar to the panel temperature. This indicates that the candela drops. ΔT for FET temperature change_fThen, the following equation (4) is established.
[0127]
B = −0.33 × ΔT_f                      … (4)
Here, the following equation (5) is derived from the equations (1) and (4).
[0128]
0.4 × P₁= −0.33 × ΔT_f
P₁= −0.825 × ΔT_f          … (5)
Equation (5) shows that the number of sustain pulses may be increased by 0.825 as a luminance correction for a 1 ° C. FET temperature rise.
[0129]
From the above study, if the luminance correction shown in Expressions (3) and (5) is performed at the same time, the luminance correction accompanying the temperature rise can be realized. That is, by adding the equations (3) and (5), the increment sustain pulse number P 'for simultaneously correcting each temperature change is obtained by the following equation (6).
[0130]
P ′ = − 0.875 × (ΔT_p+ ΔT_f…… (6)
Equation (6) above indicates that the number of sustain discharge pulses should be increased by 0.825 as a luminance correction for a 1 ° C. FET temperature rise or panel temperature rise. However, in actual control, P 'needs to be rounded off to the decimal point.
[0131]
Next, a specific operation for realizing the above equation (6) will be described.
[0132]
First, the surface temperature of the PDP 1 is detected by the temperature detector 10, and the detection signal S_TPIs output. It is preferable that the temperature detector 10 be as close as possible to the panel in order to accurately measure the temperature of the panel.
[0133]
Further, the temperatures of the X common driver 4 and the Y common driver 7 are detected by temperature detectors 5 and 8, respectively, and the detection signals S_TXAnd S_TYIs output. It is desirable that the temperature detectors 5 and 8 are also arranged as close to the elements as possible on the premise that the electrical characteristics and the heat radiation characteristics of the FET are not hindered.
[0134]
The above detection signal S_TP, S_TXAnd S_TYIs input to the microcomputer 90, temperature information of the PDP 1, the X common driver 4 and the Y common driver 7 is acquired by the microcomputer 90, and the microcomputer 90 can perform temperature information processing.
[0135]
Here, the microcomputer 90 is connected to an address selection terminal of the EP-ROM 50 storing a plurality of sustain discharge pulse numbers, thereby enabling the microcomputer control of the number of sustain discharge pulses. More specifically, the microcomputer 90 detects the detection signal S which is temperature information of the X common driver 4 and the Y common driver 7._TXAnd S_TYThe average value of the temperature corresponding to is calculated, and the difference ΔT from the reference value of 25 ° C._f, And then a detection signal S, which is temperature information of the PDP 1_TPΔT between the reference and the reference value_pIs calculated, and based on the above equation (6), the reference sustain pulse P_RIs calculated. Then, the reference sustain pulse P_RAnd the sum of the correction number P 'is calculated, and the result becomes a selection address signal of the sustain pulse number setting area 50B of the EP-ROM 50 from the microcomputer 90. In the EP-ROM 50, the number of sustain discharge pulses in each subfield with respect to the number of reference sustain pulses is set in advance._RAnd the number of corrections P ′ are output to panel drive control unit 12 as the number of sustain pulses in the subframe, and sustain pulse corresponding to the number of sustain pulses corrected by common driver control unit 31 of panel drive control unit 12 Is output, and a decrease in luminance due to temperature information is corrected.
[0136]
As described above, according to the first reference example, it is possible to finely adjust the brightness (luminance correction) based on the temperature information without changing the high-voltage system. There is an advantage that control (luminance correction) can be performed only by changing.
( III ) Second reference example
Next, the operation of the second reference example will be described with reference to FIGS.
[0137]
In the second reference example, the surface temperature of the PDP 1 is detected by the temperature detector 10, and the temperatures of the X common driver 4 and the Y common driver 7 are detected by the temperature detectors 5 and 8, respectively. Then, detection signals S output from the respective temperature detectors_TP, S_TXAnd S_TY, The brightness of the PDP 1 lowered by the temperature rise of the PDP 1 itself or each common driver is corrected. More specifically, the sustain pulse P_XSAnd P_YS(Hereinafter, the sustain discharge voltage V_SThat. ) Is corrected.
[0138]
FIG. 3 shows the sustain discharge voltage V_S4 shows the relationship between PDP1 and the luminance of PDP1.
[0139]
As shown in FIG. 3, the sustain discharge voltage V_SIs proportional to the luminance, and in this example, 2.5 candelas / V_SThat is, it can be understood that the adjustment of 2.5 candela per sustain discharge voltage Vs1 volt is possible. Brightness B, sustain discharge voltage V_SThen, the following equation (7) holds.
[0140]
B = 2.5 × V_S                            … (7)
Here, similarly to the first reference example, when the panel temperature increases by 1 ° C., the luminance decreases by 0.33 candela. Therefore, when the panel temperature change is ΔTp, the following equation (8) is satisfied.
[0141]
B = −0.33 × ΔT_p                      … (8)
The sustain discharge voltage V of the equation (7)_SThe sustain discharge voltage V_S1Then, the following equation (9) is derived from the equations (7) and (8).
[0142]

The above equation (9) represents the sustain discharge voltage V as brightness correction for a panel temperature rise of 1 ° C._SShould be increased by 0.132V.
[0143]
Further, as in the first reference example, when the FET temperature rises by 1 ° C., the luminance decreases by 0.33 candela. Therefore, the temperature change of the FET is calculated as ΔT_fThen, equation (10) holds.
[0144]
B = −0.33 × ΔT_f                      … (10)
V in equation (7)_STo V_S2Then, Expression (11) is derived from Expression (7) and Expression (10).
[0145]

Equation (11) expresses V as a luminance correction for a 1 ° C. FET temperature rise._SShould be increased by 0.132V.
[0146]
From the above considerations, it is possible to achieve the intended brightness correction by simultaneously performing the brightness correction by the formulas (9) and (11). At this time, each temperature change and the correction sustain discharge voltage V for controlling_S3Is shown in equation (12).
[0147]

The above equation (12) expresses the sustain discharge voltage V as a luminance correction for the FET temperature rise of 1 ° C. or the panel temperature rise._SShould be increased by 0.132V.
[0148]
Next, a specific operation for realizing the above equation (12) will be described.
[0149]
First, the detection of the surface temperature of the PDP 1 and the detection of the temperatures of the X common driver 4 and the Y common driver 7 are the same as those in the first reference example, and thus detailed description is omitted.
[0150]
The microcomputer 90 detects a detection signal S which is temperature information of the X common driver 4 and the Y common driver 7._TXAnd S_TYThe average value of the temperature corresponding to is calculated, and the difference ΔT from the reference value of 55 ° C._fIs calculated. In parallel with this, the microcomputer 90 detects the detection signal S that is the temperature information of the PDP 1._TPΔT between the temperature corresponding to and the reference value_pAnd calculate the reference sustain discharge voltage V based on the above equation (12)._SRCorrection number V for_S3Is calculated.
[0151]
Here, as described above, the microcomputer 90 is connected to the sustain discharge voltage reference voltage output section OUT, and thereby the sustain discharge voltage V_SCan be controlled by the microcomputer 90._SRAnd correction number V_S3, And the result is output from the sustain discharge voltage reference voltage output section OUT to an external high voltage generator, and the driving high voltage input section IN_V, And the common driver control unit 31 determines the sustain discharge voltage V based on the reference location._SIs set.
[0152]
As described above, according to the second reference example, luminance fine adjustment (luminance correction) based on temperature information can be performed with a simple circuit configuration.
( IV ) Third reference example
Next, the operation of the third reference example will be described with reference to FIGS.
[0153]
In the third reference example, the surface temperature of the PDP 1 is detected by the temperature detector 10, and the temperatures of the X common driver 4 and the Y common driver 7 are detected by the temperature detectors 5 and 8, respectively. Then, detection signals S output from the respective temperature detectors_TP, S_TXAnd S_TY, The brightness of the PDP 1 lowered by the temperature rise of the PDP 1 itself or each common driver is corrected. More specifically, the gradation value data of each sub-frame in the display data DATA is corrected.
[0154]
FIG. 4 shows the relationship between the gradation value and the luminance.
[0155]
As shown in FIG. 4, the luminance is proportional to the gradation value. In this example, it can be understood that the adjustment of 0.78 candela / STEP, that is, 0.78 candela per one step of the gradation value is possible.
[0156]
When the brightness is B and the gradation step is S, the following equation (13) is established.
[0157]
B = 0.78 × S (13)
Here, as in the first reference example, when the temperature of the PDP 1 rises by 1 ° C., the luminance decreases by 0.33 candela. Therefore, the panel temperature change ΔT_pThen, the following equation (14) holds.
[0158]
B = −0.33 × ΔT_p                      … (14)
S in the above equation (13) is S₁Then, the following equation (15) is derived from the equations (13) and (14).
[0159]
0.78 × S₁= −0.33 × ΔT_p
S₁= −0.423 × ΔT_p        … (15)
Equation (15) indicates that the gradation value should be increased by 0.423 steps as a luminance correction for a panel temperature rise of 1 ° C.
[0160]
Also, as in the first reference example, when the FET temperature rises by 1 ° C., the luminance decreases by 0.33 candela. Therefore, the FET temperature change is ΔT_fThen, the following equation (16) is established.
[0161]
B = −0.33 × ΔT_f                      … (16)
S in the above (13) is S₂Then, the following equation (17) is derived from the equations (13) and (16).
[0162]

Equation (17) shows that the gradation value should be increased by 0.423 steps as the luminance correction for the 1 ° C. FET temperature rise.
[0163]
As described above, the target luminance correction can be realized by simultaneously performing the luminance correction in Expressions (15) and (17). At this time, each temperature change and a correction gradation value S for controlling.₃Is shown in the following equation (18).
[0164]

Equation (18) indicates that the gradation value should be increased by 0.423 steps as a luminance correction for the FET temperature rise of 1 ° C. or the PDP1 temperature rise.
[0165]
Next, a specific operation for realizing the above equation (18) will be described.
[0166]
The detection of the surface temperature of the PDP 1 and the detection of the temperatures of the X common driver 4 and the Y common driver 7 are the same as those in the first reference example, and thus detailed description is omitted.
[0167]
The microcomputer 90 is connected to the display data control unit 11, and the display data control unit 11 subtracts the gradation value of each light emitting cell C based on the subtraction data from the microcomputer 90. Thus, control of the gradation value by the microcomputer 90 becomes possible.
[0168]
The microcomputer 90 detects a detection signal S which is temperature information of the X common driver 4 and the Y common driver 7._TXAnd S_TYThe average value of the temperature corresponding to is calculated, and the difference ΔT from the reference value of 55 ° C._f, And then a detection signal S, which is temperature information of the PDP 1_TPΔT between the temperature and the reference value 25 ° C_pIs calculated, and the corrected gradation value S is calculated based on the above equation (18).₃Is calculated, and the result is output to the display data control unit 11.
[0169]
The display data control unit 11 corrects the correction gradation value S from the microcomputer 90.₃The display data DATA input from the display data input unit IN is converted based on the data of. The display data DATA is temporarily stored in the frame memory 20 during the vertical synchronization period n. The data of the frame memory 20 is subtracted from the data of the frame memory 20 via the subtractor 21 by the next vertical synchronization engine n + 1, and then the control signal S is subtracted._AAre output to the address driver 3 as display data included in the PDP 1 and an image is displayed on the PDP 1. The display data DATA input to the display data control unit 11 in the vertical synchronization period n + 1 is stored and held in the frame memory 22.
[0170]
By performing the above operations alternately on the two frame memories 20 and 22, display data processing is performed, and correction of luminance reduction due to temperature rise is realized by a series of these operations.
[0171]
As described above, according to the third reference example, the luminance can be finely adjusted without changing the high-voltage system, and various controls can be performed only by changing the software when control is performed by, for example, a microcomputer. And the luminance correction can be controlled without increasing the power consumption.
(V) Fourth reference example
Next, a fourth reference example will be described with reference to FIGS.
[0172]
As described above, the scan pulse P which is the minimum necessary for normally performing the address discharge to all the selected light emitting cells C is described._AYAddress voltage V which is the voltage value of_yminBecomes larger as the temperature rises as shown in FIG.
[0173]
On the other hand, the maximum scan pulse P over which all unselected light emitting cells C do not overwrite_AYOverwrite voltage OWV which is the voltage value of_ymaxBecomes smaller as the temperature decreases, as shown in FIG.
[0174]
Therefore, in the fourth reference example, the scan pulse P_AYVoltage value V_yIs variable based on the temperature of PDP1, and always has the minimum address voltage V_yminAnd overwrite voltage OWV_ymaxWithin the appropriate range set by
[0175]
In the example of FIG. 16, the minimum address voltage V_yminAnd overwrite voltage OWV_ymaxIn both cases, there is a fluctuation of 0.17 volt for a temperature rise of 1 ° C. The temperature fluctuation of PDP1 is ΔT_p, Minimum address voltage V_yminChange of ΔV_ymin, Overwrite voltage OWV_ymaxChange of ΔV_ymaxThen, the following equations (19) and (20) hold.
[0176]
ΔV_ymin    = 0.17 × ΔT_p                  … (19)
ΔOWV_ymax= 0.17 × ΔT_p                  … (20)
Scan pulse P_AYVoltage value V_yIs generally the minimum address voltage V_yminAnd overwrite voltage V_ymaxOf the scan pulse P_AYVoltage value V_yΔV_yThen, the following Expression (21) is established by Expressions (19) and (20).
[0177]
ΔV_y= 0.17 × ΔT_p                    … (21)
Equation (21) indicates that the scan pulse P_AYVoltage value V_yShould be increased by 0.17 volts.
[0178]
Next, a specific operation for realizing the above equation (21) will be described.
[0179]
The detection of the surface temperature of the PDP 1 is the same as that in the first reference example, and thus the detailed description is omitted.
[0180]
The microcomputer 90 controls V in the voltage conversion unit 40._yA scan pulse P connected to the power supply unit 44 for performing address discharge_AYVoltage value V_yCan be controlled by the microcomputer 90.
[0181]
Then, the microcomputer 90 detects the detection signal S which is the temperature information of the PDP 1._TPΔT between the temperature corresponding to the temperature and the reference value of 25 ° C._pIs calculated, and the scan pulse P is calculated based on the equation (21)._AYVoltage value V_yCorrection value ΔV for reference potential at_yIs calculated. Next, the microcomputer 90 sets the scan pulse P_AYVoltage value V_yAnd correction value ΔV_y, And the result is expressed as V in the voltage converter 40._yOutput to the power supply unit 44. Thereby, the scan pulse P_AYVoltage value V_yCan be corrected.
[0182]
As described above, according to the fourth reference example, it is possible to cope with the drive margin fluctuation due to the temperature fluctuation, and as shown in FIG. 5, even when the width of the drive margin is narrow, the scan pulse P is always output._AYVoltage value V_yIs within the appropriate range, and the same good display can be realized as in the case where the width of the drive margin is wide.
( VI ) Fifth reference example
Next, a fifth reference example will be described with reference to FIGS.
[0183]
In the fifth reference example, the scan pulse P_AYVoltage value V_yIs always within an appropriate range, the minimum address voltage V_yminAnd overwrite voltage OWV_ymaxTo change. More specifically, during the wall charge accumulation period, the X electrode X₁Or X_N(X address voltage V_X) To thereby control the overwrite voltage V_{ym ax}With respect to the minimum address voltage V_yminIs also changed to be high at low temperatures and low at high temperatures.
[0184]
Here, FIG. 6 shows the X address voltage V_XAnd overwrite voltage OWV_ymaxAnd the minimum address voltage V_yminShows the relationship.
[0185]
As shown in FIG. 6, the X address voltage V_XIs low, the overwrite voltage OWV_ymaxIs high, but the minimum address voltage V_yminRises. On the other hand, the X address voltage V_XIs higher than the minimum address voltage V_yminLow overwrite voltage OWV_ymaxIs low. Therefore, the X address voltage V_XTo control the scan pulse P depending on the temperature._AYVoltage value V_yCan be corrected. Specifically, when the temperature is high, the X address voltage V_XIs high, and at low temperatures, the X address voltage V_XMay be controlled low.
[0186]
More specifically, the temperature fluctuation of PDP1 is ΔT_P, Minimum address voltage V_yminChange of ΔV_ymin, Overwrite voltage OWV_ymaxΔOWV_ymax16 or 17, the following equations (19) and (20) hold.
[0187]
ΔV_ymin    = 0.17 × ΔT_p                  … (19)
ΔOWV_ymax= 0.17 × ΔT_p                  … (20)
The scan pulse P shown in FIG._AYVoltage value V_yAnd X address voltage V_X, The X address voltage V_XChange ΔV_XAddress voltage V_yminChange of ΔV_ymin, Overwrite voltage OWV_ymaxΔOWV_ymaxThen, the following equations (21) and (22) hold.
[0188]
ΔV_ymin    = −0.5 × ΔV_X                  … (21)
ΔOWV_ymax= −0.5 × ΔV_X                  … (22)
The following Expressions (23) and (24) can be derived from Expressions (19) and (21) and Expressions (20) and (22), respectively.
[0189]
ΔV_X= −0.34 × ΔV_p                  … (23)
ΔV_X= −0.34 × ΔV_p                  … (24)
Equations (23) and (24) both represent V for a 1 ° C. temperature rise._XBy 0.34 volts, the minimum address voltage V due to the temperature fluctuation of PDP1 is reduced._yminAnd overwrite voltage OWV_ymax, And even if the temperature of PDP 1 fluctuates, as shown in FIG._yminAnd overwrite voltage OWV_ymaxCan be made substantially constant.
[0190]
Next, a specific operation for realizing the above equations (23) and (24) will be described.
[0191]
The detection of the surface temperature of the PDP 1 is the same as that in the first reference example, and thus the detailed description is omitted.
[0192]
The microcomputer 90 controls V in the voltage conversion unit 40._XThe X address voltage V_XCan be controlled by the microcomputer 90. The microcomputer 90 detects a detection signal S which is temperature information of the PDP 1._TPΔT between the temperature corresponding to the temperature and the reference value of 25 ° C._pIs calculated, and based on equation (23), the reference X address voltage V_XRCorrection value ΔV for_XIs calculated. Next, the microcomputer sets the reference X address voltage V_XRAnd correction value ΔV_XIs calculated, and the result is expressed as V_XOutput to the power supply unit 45. Thereby, the minimum address voltage V_yminAnd overwrite voltage OWV_ymaxCan be eliminated.
[0193]
As described above, according to the fifth reference example, the drive margin fluctuation due to the temperature fluctuation can be eliminated, and even when the width of the drive margin is narrow as shown in FIG._AYVoltage value V_yScan pulse P_AYVoltage value V_yIs within the appropriate range, and the same good display can be realized as in the case where the width of the drive margin is wide.
( VII ) Sixth reference example
Next, a sixth reference example will be described with reference to FIGS. 1, 7, and 8. FIG.
[0194]
In the sixth reference example, the scan pulse P_AYVoltage value V_yIs always within an appropriate range, the minimum address voltage V_yminAnd overwrite voltage OWV_ymaxTo change. More specifically, during the reset period, the X electrode X₁Or X_NSelf-erasing period T in the waveform of the drive voltage applied to_SEBy controlling the length of the overwrite voltage V_ymaxWith respect to the minimum address voltage V_yminIs also changed to be high at low temperatures and low at high temperatures.
[0195]
Here, as described above, the reset period is composed of two operations, that is, the entire writing by the write pulse and the self-erasing, and the self-erasing period T is one of the parameters for determining the self-erasing ability._SEThere is. This self-erasing period T_SEThe longer the is, the more perfect the self-erasure is.
[0196]
Now, FIG. 8 shows the self-erasing period T_SEAnd overwrite voltage OWV_ymaxAnd the minimum address voltage V_yminShows the relationship.
[0197]
As shown in FIG._SEIs longer, the self-erase becomes more perfect, and as a result, the minimum address voltage V_yminAnd overwrite voltage OWV_ymaxIs found to decrease. Therefore, the self-erasing period T_SETo control the scan pulse P depending on the temperature._AYVoltage value V_yCan be corrected. Specifically, at a high temperature, the self-erasing period T_SEAnd the self-erasing period T at low temperatures_SEMay be controlled to be short.
[0198]
Now, the self-erasing period T_SEChange ΔT_SEAddress voltage V_yminChange of ΔV_ymin, Overwrite voltage OWV_ymaxΔOWV_ymaxThen, in the case shown in FIG. 8, the following equations (25) and (26) hold.
[0199]
ΔV_ymin    = −0.17 × ΔT_SE              … (25)
ΔOWV_ymax= −0.17 × ΔT_SE              … (26)
Here, the temperature fluctuation of PDP1 is ΔT_pThen, in the example of FIG. 16, the following equations (19) and (20) hold.
[0200]
ΔV_ymin= 0.17 × ΔT_p                  … (19)
ΔV_ymax= 0.17 × ΔT_p                  … (20)
Equations (27) and (28) are derived from Equations (25) and (19) and Equations (26) and (20), respectively.
[0201]
ΔT_SE= -ΔT_p                      … (27)
ΔT_SE= -ΔT_p                      … (28)
The above equations (27) and (28) both show the self-erasing period T with respect to the temperature rise of the PDP 1 of 1 ° C._SEIs shortened by 1 μsec, so that the minimum address voltage V_yminAnd overwrite voltage OWV_ymax, And even if the temperature of PDP 1 fluctuates, as shown in FIG._yminAnd overwrite voltage OWV_ymaxCan be made substantially constant.
[0202]
Next, a specific operation for realizing Expressions (27) and (28) will be described.
[0203]
The detection of the surface temperature of the PDP 1 is the same as that in the first reference example, and thus the detailed description is omitted.
[0204]
The microcomputer 90 detects a detection signal S which is temperature information of the PDP 1._TPΔT between the temperature corresponding to the temperature and the reference value of 25 ° C._pIs calculated, and based on the equation (27), the reference self-erasing period T_SERCorrection value ΔT for_SEIs calculated.
[0205]
Next, the microcomputer 90 sets the reference self-erasing period T_SERAnd correction value ΔT_SEIs calculated, and the result is output to the waveform selection address of the drive waveform area 50A in the EP-ROM 50. Of the two or more arbitrary drive waveforms, the desired self-erasing period T_SEIs selected, and the X electrode X during the reset period is selected.₁Or X_NIs output to the panel drive section 12 to drive each driver.
[0206]
As described above, according to the sixth reference example, it is possible to eliminate the drive margin variation due to the temperature variation, and even when the drive margin width is narrow, the scan pulse P_AYVoltage value V_yScan pulse P_AYVoltage value V_yIs within the appropriate range, and the same good display can be realized as in the case where the width of the drive margin is wide.
( VIII ) Seventh reference example
Next, a seventh reference example will be described with reference to FIGS.
[0207]
In the seventh reference example, in order to prevent an excessive wall charge from accumulating due to an abnormal discharge in the address period (hereinafter, referred to as an address strong discharge) and prevent the light emitting cells C to be lit in the sustain discharge from flickering, Signal P that serves to remove excess wall charges between the discharge period and the sustain discharge period_HIs entered.
[0208]
This neutralization signal P_HFIG. 9 shows an example of the waveform.
[0209]
Neutralization signal P_HIn the X electrode X₁Or X_NAnd Y electrode Y₁Or Y_NIs the same potential, no discharge occurs between the X electrode and the Y electrode.
[0210]
Y electrode Y generated by strong address discharge₁Or Y_NExcess ions (positive wall charges) above the neutralization signal P_HAddress electrode A₁Or A_MIt reacts with the upper electron (negative wall charge), and the weak wall discharge removes the excess wall charge. At this time, the potentials of the X electrode and the Y electrode are set to V_SThen, the address electrode A₁Or A_MPotential is 1 / 2V_SIs 2 / 3V_SHas been experimentally confirmed to be optimal. This address electrode A₁Or A_MIs smaller than the optimum value, the intended weak discharge does not occur. On the other hand, if the potential is smaller than the appropriate value, the discharge increases and the wall charges are removed more than necessary.
[0211]
This neutralization signal P_HWhen operated in a cell that does not need to be removed, an appropriate amount of wall charges may be reduced. Therefore, it is preferable that the neutralization signal P be used only at a low temperature when this problem occurs remarkably._HIt is desirable to output and not output otherwise.
[0212]
Next, a specific operation of the seventh reference example will be described.
[0213]
The detection of the surface temperature of the PDP 1 is the same as that in the first reference example, and thus the detailed description is omitted.
[0214]
The detection signal S input to the microcomputer 90_TPWhen the temperature of the PDP 1 falls below a predetermined threshold value, a signal indicating this fact is output from the microcomputer 90 to the EP-ROM 50. This signal enters the waveform selection address of the drive waveform area 50A in the EP-ROM 50 and the neutralization signal P_HIs selected and output to the panel drive control unit 12 to output the neutralization signal P_HAre generated.
[0215]
If the temperature of PDP1 exceeds a set threshold, neutralization signal P_HIs selected. Here, as a specific value of the threshold, it is desirable to set from 0 ° C. to + 5 ° C. at which the lighting defective cell rate sharply increases, from FIG.
[0216]
As described above, according to the seventh reference example, when the PDP 1 is at a predetermined low temperature, the neutralization signal P_HIs output, the excess wall charges are neutralized, and the light emitting cells C with poor lighting are not generated.
( IX ) Eighth reference example
Next, an eighth reference example will be described with reference to FIG.
[0217]
In the eighth reference example, the abnormal discharge during the address period (hereinafter, referred to as the strong address discharge) causes excessive wall charges to accumulate, and the light-emitting cells C to be lit in the sustain discharge are reduced from blinking. The PDP 1 is heated when the PDP 1 is at a low temperature, for example, at the time of start-up or when the entire canceling screen (a screen where nothing is displayed) continues to cause a problem.
[0218]
As shown in the temperature characteristics shown in FIG. 18, this problem becomes more conspicuous as the temperature of PDP 1 becomes lower. In general, a PDP generates heat by its plasma discharge, so that the panel temperature gradually rises as light is emitted. Therefore, at the time of low temperature immediately after power-on or the like where this problem becomes remarkable, the PDP 1 is heated to forcibly raise the temperature in order to shorten the period in which this problem remarkably occurs as much as possible.
[0219]
Next, a specific operation will be described.
[0220]
The detection of the surface temperature of the PDP 1 is the same as that in the first reference example, and thus the detailed description is omitted.
[0221]
The detection signal S input to the microcomputer 90_TPWhen the temperature of the PDP 1 falls below a predetermined threshold value based on the above, the result is output to the panel heating device 9. As a result, the panel heating device 9 operates to forcibly heat the PDP 1.
[0222]
When the temperature of PDP 1 exceeds the threshold value, microcomputer 90 outputs a signal for stopping the operation of panel heating device 9.
[0223]
As described above, according to the eighth reference example, the period in which the light emitting cells C to be lit in the sustain discharge blinks can be shortened, and the blinking of the light emitting cells C to be lit can be reduced.
(X) First embodiment
Next, a first embodiment corresponding to the first, fourth, seventh, tenth, and thirteenth inventions will be described with reference to FIG.
[0224]
According to the first embodiment, when the ambient temperature for operating the PDP 1 is abnormally high, or when an unexpected trouble occurs, the plasma display device S including the PDP 1 is used.₁Temperature abnormally rises, exceeds the temperature rating of the circuit element, and when the circuit element may be damaged, the temperature of the PDP 1 or the like reaches a set temperature that may lead to an abnormal mode. In this case, an air cooling device such as a fan is operated to perform an air cooling process.
[0225]
Next, a specific operation will be described.
[0226]
The detection of the surface temperature of the PDP 1 and the detection of the temperatures of the X common driver 4 and the Y common driver 7 are the same as those in the first reference example, and thus detailed description is omitted.
[0227]
In the first embodiment, in addition to the above, the plasma display device S₁To detect the temperature. Here, the in-apparatus ambient temperature detector 60 is desirably disposed at a position as far as possible from high heat components such as FETs in order to measure the in-apparatus ambient temperature as accurately as possible.
[0228]
The detection signal S input to the microcomputer 90_TP, S_TXAnd S_TYWhen any one or more of the temperature information exceeds the threshold value set for each of the temperature information based on the detection signal of the in-apparatus ambient temperature detector 60, the air-cooling device 80 is operated by the control circuit 81 based on the result. . This operation is continued until all the temperature information input to the microcomputer 90 falls below the threshold. The detection signal S_TPAbout 60 ° C and the detection signal S_TXAnd S_TYAbout 100 ° C., and about 50 ° C. for the detection signal of the ambient temperature detector 60 in the apparatus.
[0229]
As described above, according to the first embodiment, abnormal operation of the PDP 1 or each driver due to the temperature of the PDP 1 or each driver rising to a predetermined value or more can be prevented, and the PDP 1 or each driver can be prevented. Reliability is improved.
( XI ) Second embodiment
Next, a second embodiment corresponding to the invention described in claims 2, 5, 8, 11, and 13 will be described with reference to FIG.
[0230]
According to the second embodiment, when the ambient temperature for operating the PDP 1 is abnormally high, or when an unexpected trouble occurs, the plasma display device S including the PDP 1 is used.₁Temperature abnormally rises, exceeds the temperature rating of the circuit element, and when the circuit element may be damaged, the temperature of the PDP 1 or the like reaches a set temperature that may lead to an abnormal mode. At this time, the user is warned of this by blinking the LED.
[0231]
Next, a specific operation will be described.
[0232]
In the second embodiment, the plasma display device S is controlled by the in-device ambient temperature detector 60 shown in FIG.₁Is being monitored. Since the arrangement of the in-apparatus ambient temperature detector 60 is the same as that of the first embodiment, detailed description is omitted.
[0233]
The detection signal S input to the microcomputer 90_TP, S_TXAnd S_TYIf any one or more of the temperature information exceeds the threshold value set for each of the temperature information based on the detection signal of the in-apparatus ambient temperature detector 60, the microcomputer 90 activates the control circuit 71 to inform the user. On the other hand, the LED 70 indicating a warning is turned on. This operation is continued until the temperature information based on all the detection signals falls below the threshold. As a specific example of the threshold value, about 70 ° C. is appropriate in the case of the in-apparatus ambient temperature detector 60.
( XI ) Third embodiment
Next, a third embodiment corresponding to the invention described in claims 3, 6, 9, 12, and 13 will be described with reference to FIG.
[0234]
According to the third embodiment, when the ambient temperature for operating the PDP 1 is abnormally high, or when an unexpected trouble occurs, the plasma display device S including the PDP 1 is used.₁Temperature abnormally rises, exceeds the temperature rating of the circuit element, and when the circuit element may be damaged, the temperature of the PDP 1 or the like reaches a set temperature that may lead to an abnormal mode. When the plasma display device S₁The power supply to is prohibited.
[0235]
Next, a specific operation will be described.
[0236]
Detection of the surface temperature of the PDP 1, detection of the temperatures of the X common driver 4 and the Y common driver 7, and the plasma display device S using the in-device ambient temperature detector 60₁The detection of the internal temperature of the apparatus is the same as that of the first embodiment, so that the detailed description is omitted.
[0237]
The microcomputer 90 operates the relay control unit 91 when any one or more of the temperature information exceeds the threshold value set for each of the temperature information based on the detection signal input from each of the temperature detectors. The high-voltage line is temporarily cut off. This operation is continued until all the pieces of temperature information fall below the threshold. The detection signal S_TPAbout 90 ° C and the detection signal S_TXAnd S_TYAbout 130 ° C., and about 80 ° C. for the detection signal from the ambient temperature detector 60 in the apparatus.
[0238]
As described above, according to the third embodiment, when the temperature of the PDP 1 or the like rises to a predetermined value or more, the operation thereof can be stopped, and the abnormal operation due to the temperature rise of the predetermined value or more can be stopped. The device or the like can be protected.
[0241]
【The invention's effect】
Claim1Or5According to the invention described in (1), based on the temperature of the plasma display panel, when the temperature is equal to or higher than the predetermined value, the supply of power to the plasma display panel is prohibited, so that the temperature of the plasma display panel is equal to or higher than the predetermined value. When the temperature rises to a value above, the operation of the plasma display panel can be stopped, and the plasma display panel can be protected from abnormal operation due to a temperature rise above the predetermined value.
[0242]
Claim2Or6According to the invention described in the above, based on the temperature of the plasma display panel and the temperature of the driving unit, when the temperature of the plasma display panel is equal to or higher than the first predetermined value, or when the temperature of the driving unit is equal to or higher than the second predetermined value In this case, since the plasma display panel or the driving unit is cooled, it is possible to prevent the abnormal operation of the plasma display panel or the driving unit due to the temperature of the plasma display panel or the driving unit rising to a predetermined value or more. As a result, the reliability of the plasma display panel or the driving means is improved.
[0243]
Claim3Or7According to the invention described in the above, based on the temperature of the plasma display panel and the temperature of the driving unit, when the temperature of the plasma display panel is equal to or higher than the first predetermined value, or when the temperature of the driving unit is equal to or higher than the second predetermined value Warning is issued to the user.
[0244]
Therefore, the user can recognize that the temperature of the plasma display panel or the driving unit has risen to the predetermined value or more, and take a measure to prevent abnormal operation of the plasma display panel or the driving unit due to the temperature rise. Can be taken.
[0245]
Claim4Or8According to the invention described in the above, based on the temperature of the plasma display panel and the temperature of the driving means, when the temperature of the plasma display panel is equal to or more than the first predetermined value, the supply of power to the plasma display panel is prohibited, When the temperature of the driving unit becomes equal to or higher than the second predetermined value, supply of power to the driving unit is prohibited.
[0246]
Therefore, when the temperature of the plasma display panel or the driving unit rises to the predetermined value or more, the operation of the plasma display panel or the driving unit can be stopped, and the abnormal operation due to the temperature rise of the predetermined value or more can be stopped. The plasma display panel or the driving means can be protected.
[0247]
Claim9According to the invention described in (1), the claims5Or8By the heating prevention device according to any one of the above, the heating of the plasma display panel or the driving unit is prevented, and display is performed, so that even if the temperature of the plasma display panel or the driving unit increases, the plasma display panel by heating Or, abnormal operation or breakage of the driving means can be prevented, and the reliability of the plasma display device is improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration block diagram of a plasma display device according to an embodiment and a reference example.
FIG. 2 is a graph showing a relationship between the number of sustain discharge pulses and luminance.
FIG. 3 is a graph showing a relationship between a sustain discharge voltage and luminance.
FIG. 4 is a graph showing a relationship between a gradation value and luminance.
FIG. 5 is a graph showing V based on panel temperature after processing according to a fourth reference example._yFIG. 7 is a graph showing an example of a change in the graph.
FIG. 6 is a graph showing a relationship among an X address voltage, a minimum address voltage, and an overwrite voltage according to a fifth reference example.
FIG. 7 shows panel temperature and V according to the fifth and sixth reference examples._yIt is a graph which shows the relationship with an example of a set value.
FIG. 8 is a graph showing a relationship between the length of a self-erasing period, a minimum address voltage, and an overwrite voltage according to a sixth reference example.
FIG. 9 is a diagram showing a waveform of a neutralization signal in a seventh reference example.
FIG. 10 is a diagram showing a configuration (plan view) of a conventional PDP.
11A and 11B are diagrams showing a configuration (cross-sectional view) of a conventional PDP, wherein FIG. 11A is a cross-sectional view between α-α ′ in FIG. 10 and FIG. 11B is a cross-sectional view between β-β ′ in FIG. FIG.
FIG. 12 is a schematic configuration block diagram of a conventional plasma display device.
FIG. 13 is a timing chart showing the operation of the conventional plasma display device.
FIG. 14 is a diagram showing a frame structure of display data according to the related art.
FIGS. 15A and 15B are graphs showing the relationship between the temperature of the plasma display panel and the temperature and luminance of the driving FET, FIG. 15A is a graph showing the relationship between the temperature and the luminance of the plasma display panel, and FIG. FIG. 3 is a graph showing the relationship between the temperature and the brightness of the FET.
FIG. 16 shows plasma display panel temperature and suitability V_yIt is a graph which shows the relationship with a setting range.
FIG. 17 shows plasma display panel temperature and V_yIt is a graph which shows the relationship with the settable range, (a) is V_yThis is the case where the settable range is wide._yThis is the case where the settable range is narrow.
FIG. 18 is a graph showing the relationship between the temperature of the plasma display panel and the lighting failure cell rate.
[Explanation of symbols]
1,100 ... PDP (plasma display panel)
2, 110 ... control circuit
3, 111 ... address driver
4, 112 ... X common driver
5, 8, 10 ... temperature detector
6, 113 ... Y scan driver
7, 114 ... Y common driver
9 Panel heating device
11, 120... Display data control unit
12, 121 ... Panel drive control unit
20, 22, 130 ... frame memory
21 ... Subtractor
30, 140 ... scan driver control unit
31, 141: common driver control unit
40 ... voltage converter
41 ... V_aPower supply part
42 ... V_WPower supply part
43… V_SCPower supply part
44 ... V_yPower supply part
45 ... V_XPower supply part
50 ... EP-ROM
50A: drive waveform area
50B ... sustain pulse number setting area
60 ... Ambient temperature detector in the device
70… LED
71, 81 ... control circuit
80 ... Air cooling device
90 ... microcomputer
91 ... Relay control unit
92 ... Current consumption detecting section
101: back glass substrate
102 ... M_gO film
103: dielectric layer
104 bus electrode
105 ... Transparent electrode
103 front glass substrate
200, S₁... Plasma display devices
IN: Display data input section
IN_V… Drive high voltage input
OUT: Reference voltage output section
DATA… Display data
A₁, A₂, A₃, A₄, A₅, A₆, A₇, A₈, A₉, A_M… Address electrode
B ... Barrier
C: Light emitting cell
X₁, X₂, X₃, X₄, X_N... X electrode
Y₁, Y₂, Y₃, Y₄, Y_N... Y electrode
S_A, S_YS, S_YC, S_X…Control signal
S_TP, S_TX, S_TY… Detection signal
P_AA… Address pulse
P_AY… Scan pulse
P_AW, P_XW… Write pulse
P_XS, P_YS... sustain pulse
P_H… Neutralization signal
CLK: dot clock
VSYNC: vertical synchronization signal
HSYNC: horizontal synchronization signal
T_SE… Self-erasing period

Claims (9)

A detection step of detecting the temperature of the plasma display panel,
Based on the detected temperature, when the temperature is equal to or higher than a predetermined value, a prohibition step of prohibiting power supply to the plasma display panel,
A method for preventing heating of a plasma display panel, comprising: A first detection step of detecting the temperature of the plasma display panel;
A second detection step of detecting a temperature of driving means for driving the plasma display panel;
Based on the detected temperature of the plasma display panel and the temperature of the driving unit, when the temperature of the plasma display panel is equal to or higher than a first predetermined value, the plasma display panel is cooled, and the temperature of the driving unit is reduced. A cooling step of cooling the driving means when the value is equal to or more than a second predetermined value;
A method for preventing heating of a plasma display panel, comprising: A first detection step of detecting the temperature of the plasma display panel;
A second detection step of detecting a temperature of driving means for driving the plasma display panel;
Based on the detected temperature of the plasma display panel and the temperature of the driving unit, when the temperature of the plasma display panel is equal to or higher than a first predetermined value, or when the temperature of the driving unit is equal to or higher than a second predetermined value. A warning process that issues a warning if
A method for preventing heating of a plasma display panel, comprising: A first detection step of detecting the temperature of the plasma display panel;
A second detection step of detecting a temperature of driving means for driving the plasma display panel;
Based on the detected temperature of the plasma display panel and the temperature of the driving unit, when the temperature of the plasma display panel becomes equal to or higher than a first predetermined value, the supply of power to the plasma display panel is prohibited, and the driving is performed. A prohibition step of prohibiting power supply to the driving means when the temperature of the means is equal to or higher than a second predetermined value;
A method for preventing heating of a plasma display panel, comprising: Detecting means for detecting the temperature of the plasma display panel and outputting a detection signal;
Prohibition means for prohibiting the supply of power to the plasma display panel when the temperature is equal to or higher than a predetermined value based on the detection signal;
A device for preventing heating of a plasma display panel, comprising: First detection means for detecting the temperature of the plasma display panel and outputting a first detection signal;
A second detection unit that detects a temperature of a driving unit that drives the plasma display panel and outputs a second detection signal;
When the temperature of the plasma display panel is equal to or higher than a first predetermined value based on the first detection signal and the second detection signal, the plasma display panel is cooled, and the temperature of the driving unit is reduced to a second predetermined value. In the case described above, cooling means for cooling the driving means,
A device for preventing heating of a plasma display panel, comprising: First detection means for detecting the temperature of the plasma display panel and outputting a first detection signal;
A second detection unit that detects a temperature of a driving unit that drives the plasma display panel and outputs a second detection signal;
Based on the first detection signal and the second detection signal, a warning is issued when the temperature of the plasma display panel is equal to or higher than a first predetermined value or when the temperature of the driving unit is equal to or higher than a second predetermined value. Warning means for issuing
A device for preventing heating of a plasma display panel, comprising: First detection means for detecting the temperature of the plasma display panel and outputting a first detection signal;
A second detection unit that detects a temperature of a driving unit that drives the plasma display panel and outputs a second detection signal;
When the temperature of the plasma display panel becomes equal to or higher than a first predetermined value based on the first detection signal and the second detection signal, supply of power to the plasma display panel is prohibited, and the temperature of the driving unit is reduced. Prohibiting means for prohibiting the supply of power to the driving means when the value is equal to or greater than a second predetermined value;
A device for preventing heating of a plasma display panel, comprising: A device for preventing heating of a plasma display panel according to any one of claims 5 to 8 ,
Control means for controlling driving means for driving the plasma display panel based on display data input from the outside,
Under the control of the control means, the driving means for driving the plasma display panel,
The plasma display panel driven by the driving unit and performing the display,
A plasma display device comprising:

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