JP2004022304A - Induction heating cooking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating cocking device allowing easy heating cooking at a proper location determined by an instantaneous, accurate, and automatic/manual decision without requiring a drive of an inverter circuit, improving operability, handling safety and the safety of a cooking stove. <P>SOLUTION: The induction heating cooking device heats a heating cooking object by applying a high frequency current to a heating coil 1. The induction heating cooking device comprises a light detecting means 3 for detecting light incident to a plurality of points on a top plate where the heating cooking object is placed or light irradiated from the lower surface of the top plate and reflecting the bottom surface of the heating cooking object, a status decision means 4 for determining the status and shape of the object placed on the top plate, or the status on the top plate according to the combination of a plurality of results detected by the light detecting means 3, and a control means 5 for controlling according to the decision results generated by the status decision means 4. <P>COPYRIGHT: (C)2004,JPO

Description

まず、状態ａでは、「１〜１３」の全ての光検知手段３が光を検知している。つまり、トッププレート６の透明部６ａを入射光が透過しているので鍋２が載置されていない状態であるので、「鍋なし」と判定される。状態ｂではセンター１Ｓの「１」のみが光を検知していない。つまり何らかの載置物で「１」の光検知手段３に対向した透明部６ａが塞がれた状態であるので、「小物または鍋底の直径が１１０ｍｍ以下の小鍋が載置されている」と判定される。
【００３２】
状態ｃでは、センター１Ｓよりやや右側に偏心した「２」のみが光を検知していないので、「小物または前記小鍋が載置されている」と判定される。状態ｉでは、「１」「２」「５」「８」「９」「１１」が光を検知していない。つまりセンターよりやや左側に偏心した位置に鍋２が載置されているとみなして「鍋ズレ」と判定される。状態ｊでは、「１」「２」「５」「６」「８」「９」「１１」が光を検知していない、つまり状態ｉより鍋底の直径がやや大きい鍋２が、センターよりやや左側に偏心した位置に載置されているとみなして「鍋ズレ」と判定される。このように、鍋２がセンター１Ｓに対して偏心しているのであれば、その偏心度合に応じて前記検知している箇所および検知していない箇所が互いに逆な方向に片寄って存在し、それらの片寄り度合や状態が変化する相関性から鍋２の偏心を判定することができる。
【００３３】
またこの一覧表では示していないが、センター１Ｓから４方に向けて等距離に配置される光検知手段３が光を検知していないときは鍋が適正な位置に載置されている「鍋あり」と判定され、その際に鍋底の大きさや形状も同時に判定される。このように、センター１Ｓに同心に載置された鍋２に対して、これを検知している検知箇所が中央側に存在し、検知しない検知箇所が鍋２の大きさ、形状に応じた周辺域上の対応箇所に存在し、それらの存在域数、存在箇所の数や位置が変化する相関性から、鍋２の大きさや形状を判定することができる。
【００３４】
以上説明した実施例１によれば、光検知手段３が入射光の有無を検知した検知結果が、鍋２の大きさ、形状、載置ずれ等の載置物の状態に応じて変化する相関関係から、鍋２の載置の有無、鍋２の載置ズレと鍋底の大きさ、トッププレート６上の小物載置を状態判定手段４が瞬時にかつ正確に判定することができる。また調理中に鍋２を取外した場合は、そのとき生じる先の状態からの一部または全体の検知結果の変転を伴い全て同じ検知結果になる変化から的確に行うことができる。そしてその判定は負荷判定手段７でなくインバータ回路１６の駆動を要しない光検知手段３と状態判定手段４を用いるので、発振素子１５に負担をかけることなく、また無用な電磁波を発することなく適正な鍋２を載置した場合はすぐに加熱を再開できるので、使い勝手及びコンロの安全性を向上させることができる。
【００３５】
また、状態判定手段４は光検知手段３による光検知の有無（１か０か）だけでなくその検知値の違いにより、トッププレート６上の汚れも判定することができる。例えば、鍋あり判定のしきい値より大きい所定値を鍋なし判定のしきい値とし、それより大きい検知値の範囲内で「１〜１３」の光検知手段３の最大検知値との差をみて、汚れ度合を判定することができる。その際、トッププレート６とは別の位置に、周囲明度を検知する周囲明度検知手段３２を設け、周囲明度検知手段３２からの出力値から周囲明度レベルを判定し、判定した周囲明度レベルにより、光検知手段３での各しきい値を補正すると好適である。周囲の明るさより光検知手段３の検知値は変わるので、光検知手段３の検知値を３つのレベル、つまりレベル１→「鍋が載置されている」、レベル２→「鍋が載置されていない」、レベル３→「トッププレート６が汚れている」に分け、各レベルに応じて各しきい値を補正することで、より正確な判定が行える。
【００３６】
尚、載置物の状態とトッププレートの状態の検知を別々に説明したが、両方の複数の検知結果を組み合わせて総合的に判定することもできる。
【００３７】
また、上述した光検知手段３は入射光を検知するものであったが、反射光を検知するものでもよく、反射光検知方式は、上述した入射光検知方式よりも鍋底の大きさを正確に検知することができる。なぜなら鍋２の全体形状（最大径と鍋底の径との差が大きい鍋等）によっては鍋底判定が曖昧になる場合があるからである。しかしこの場合でも負荷判定手段７との併用によって総合的に判定することによって、入射光検知方式の精度を保つことが可能である。また、負荷判定と汚れ判定とを併用することもでき、負荷が小さいと判定され、かつ光を検知していない箇所がある場合に、その検知位置や検知値の違いによって、汚れと非磁性体との判定を明確に区別できるようになる。
【００３８】
ところで、誘導加熱調理器においては、固有振動・磁界反発により鍋２が振動する場合があり、加熱調理開始時には適正な位置であっても前記振動により鍋２がズレてしまう場合がある。そこで加熱調理中に光検知手段３と状態判定手段４により、載置ズレを検知し判定された場合には、その時点での発振周波数を記憶しておき、次回に加熱した際、負荷判定手段７と状態判定手段４とからその記憶値を持つ鍋２と判定された場合に、記憶された発振周波数近傍での発振を避けて加熱することにより、振動による載置ズレを確実に防止することができる。制御回路５はこういった状態判定手段４の判定結果に基づいた発振周波数制御のほか、判定結果の外部報知、電流制御、電流供給遮断の少なくとも１つの措置を行う。調理者は外部報知によって、鍋２の載置忘れや載置ズレと措置の必要に気付き、適正な位置に鍋２を載置し直したり、載置し直されない場合は、載置ズレのまま加熱されることのないように電流制御により加熱出力を減少させたり、電流供給遮断により加熱出力を停止したりするなど速やかな対応ができ、措置が遅れたりなされなかったりするのを防止することができる。
【００３９】
また、鍋２の載置ズレ（偏心やはみ出し）と判定されると、その度合いに応じて温度検知手段８により検知した検知温度を補正すると好適である。温度検知手段８は加熱コイル１の中心位置で、トッププレート６の下面に配されるので、加熱調理中に鍋２がずれて底の中心が温度検知手段８の上方に位置しなくなったことによって、鍋２の実温と検知温度とに誤差が生じ、その誤差によって、鍋２が過発熱されて吹きこぼれ等の問題が発生することがある。煮物制御や揚げ物モードにおいてはこの誤差が事故につながる可能性が高いので、その安全策を採ることは必須であるが、検知温度を補正することによって鍋２が適正位置にない場合でも温度検知を正確に行い、検知温度のズレによる前記問題を防止することができる。
【００４０】
（実施例２）
実施例１の光検知手段３はトッププレート６を透過した入射光を検知するものであったが、トッププレート６の下方に光源を設け、そこから照射した光がトッププレート６の下面で反射した光を検知するものであってもよく、その場合には鍋底の反りによる浮き、つまり鍋底の形状も検知することができる。
【００４１】
実施例２では、載置物の状態判定とその電流制御の１例として、鍋底の浮きを反射光検知方式を用いて判定し、その判定結果に基づいて制御する場合を揚げ物モードを例に採り、図を用いずに説明する。尚、上述した温度検知手段８の検知温度の誤差は、鍋ズレ以外に鍋底の浮きによっても生じるので、この場合においても温度検知手段８の補正を行うと好適であることはいうまでもない。
【００４２】
揚げ物モードは、インバータ回路搭載の家庭用の誘導加熱調理器の機能の１つとして採用されており、天ぷら等の揚げ物を行うための専用自動加熱制御のことである。使用者がそのモードを選択し、油の希望温度を設定すると、その設定温度まで自動加熱を行い、かつその設定温度を保つように加熱制御を行う。所定温度以上に油を加熱してしまうと発火するおそれがあるが、この油の異常加熱の原因としては、油の量をメーカー最少設定値（５００ｇ）以下で使用した場合と、鍋底の反りによる浮き（２ｍｍ程度の反りがあるだけで、鍋の実温を検知しきれずに過発熱してしまう。）等が原因となる。そこでメーカーは揚げ物の専用鍋を付属品として付けることにより、鍋底の浮きの問題に対応している。
【００４３】
そこで実施例２では、光検知手段３（反射光検知方式）により鍋底の形状（浮き）を判定し、その判定形状が専用鍋の形状と一致した場合は、その鍋の特質（浮き・比熱・規格容量等）を考慮に入れた使い勝手を重視した加熱制御とする。一致しない（専用鍋でない）場合は、加熱出力を落とし、安全性を重視した（使い勝手よりも安全性を優先）加熱制御とする。また、判定した鍋底の形状を考慮した温度検知、油の量判定を行うことにより、安全性をより向上することができる。
【００４４】
負荷特性は鍋毎に決まっているので、専用鍋の負荷特性を予め記憶させておけば、加熱中の鍋の負荷がこの記憶値と同一か否かを比較することにより、専用鍋か否かを判定できる。しかしながら負荷が同じというだけでは、専用鍋かどうかを正しく判定することができない。なぜなら専用鍋よりも大きくてかつ磁性度合や電気抵抗値の低い鍋の場合も同じ負荷となる場合があるからである。そこで、負荷判定手段７の判定結果に状態判定手段４の判定結果（鍋底の大きさ検知による判定）を合わせることによって、専用鍋か否かを正確に判定することができる。
【００４５】
さらに、専用鍋と判定したときは決められた定出力で加熱を行い、専用鍋でないと判定したときは前記定出力より小さい出力に補正して加熱を行うようにすると好適である。専用鍋でないということは鍋底に浮きがある可能性があるので、安全性のため低い出力にて緩やかに加熱する。また、鍋底の大きさによって（鍋底が大きいほど鍋底の浮きが大きい可能性があるため）、前記補正度合を小さくすることもできる。
【００４６】
（実施例３）
図５に示す実施例３は実施例２と同じく反射光検知方式を採り、トッププレート６の下方に光源３４を設け、その反射光を検知する光検知手段３Ａを設けている。尚、実施例３は加熱調理中の吹きこぼれ汚れを特に検知するものとしてるので、光源３４は加熱コイル１の周囲に環状に配置し、加熱調理終了後に数秒間照射することとする。
【００４７】
図５（ａ）に示すように、トッププレート６上に汚れがなければ光源３４から照射した光はそのままトッププレート６を透過するので、光検知手段３Ａは光を検知しないが、図５（ｂ）のように、トッププレート６上に汚れがあると、光源３４から発射した光は汚れがあるトッププレート６下面で反射し、その反射光を光検知手段３Ａが検知し、その検知結果に基づいて状態判定手段４が汚れと判定する。そして汚れと判定されたときには、報知手段１１でブザー音で報知したり、表示手段１０でランプを点滅させたりして調理者に注意を促す。これらの報知により、調理者が汚れに気付きトッププレート６の汚れを拭き取ることができるので、汚れによる加熱効率の低下や光検知手段の誤検知を防止することができると共に、害虫を寄せつけない衛生的な使用を図ることができる。
【００４８】
（実施例４）
実施例１で説明したように、誘導加熱調理器において安全に効率良く加熱調理を行うためには、鍋２をズレなく加熱コイル１のセンター１Ｓに合わせて適正位置に載置する必要がある。実施例１では、光検知手段３で載置ズレを検知して状態判定手段４によりそれを判定していたが、実施例４ではトッププレート６に図６と図７に示すような位置確認表示手段３６を設けることによって、調理者がその表示を目視して鍋２の載置状態を判定するようにしている。
【００４９】
この位置確認表示手段３６は、トッププレート６のほぼ全域に、加熱コイル１のセンター１Ｓより、３方以上に、連続・不連続・繰返しの少なくとも１つの共通した態様を持って拡がるように形成されたものであるが、実施例４の位置確認表示手段３６は、図７（ａ）に示すように加熱コイル１のセンター１Ｓと同じセンターを持ち、１辺の長さｒが２６ｃｍ以上の三角形状としている。この三角形状を表示するために、複数の発光素子が、図６に示すように操作・表示パネルに設けられた位置確認スイッチ３５の操作により、表示点灯するように構成されている。
【００５０】
従来の円形表示の場合は、鍋底２ａの直径が２６ｃｍの大鍋を使用する場合、鍋によって表示が隠れてしまい、鍋底２ａを加熱コイル１のセンター１Ｓに合わせて正確に載置することができず、使い勝手が悪いものであった。そこで実施例４の三角表示では、図７（ａ）に示すように大鍋の鍋底２ａによって、三角形の頂部まで表示が隠れてしまうことがなく明瞭に必ず現れるようになるので、従来の１重円より正確に判定を行える。
【００５１】
図７（ａ）（ｂ）の実線で示すように、センター１Ｓと同心に鍋が載置された場合には、鍋底２ａで三角形の中央側が隠れ、鍋底２ａによって隠れない三角表示が、鍋底２ａの大きさ、形状に応じて周辺３方に突出して現れ、それら頂部の突出量、面積のバランスを目視して、鍋底２ａの大きさや形状を調理者が正確に判定することができる。
【００５２】
また図７（ａ）（ｂ）の仮想線で示すように、鍋底２ａがセンター１Ｓに対して偏心しているのであれば、その偏心度合に応じて鍋底２ａによって隠れない三角表示の頂部が前記偏心に対応する方向に片寄って現れ、それらの片寄り度合を目視して、鍋底２ａの偏心を調理者が正確に判定することができる。このように調理者は、トッププレート６のほぼ全域に設けられることにより鍋底２ａで隠れることなく必ず目視できる位置確認表示手段３７の拡がり部分（実施例３では三角形の頂部）を目視して鍋２の載置状態を判定し、トッププレート６上の適正な位置つまり加熱コイル１と鍋底２ａとの同心位置に鍋を載置して加熱調理を行うことができるので、使い勝手がよくなると共に、載置ズレによる温度検知手段８の検出不良から生じる鍋２の過発熱を防止できるので、使用およびコンロの安全性も向上する。
【００５３】
尚、位置確認表示手段３６の三角表示は、上記のような点灯表示でなく、印刷などによるデザイン表示とすることも可能である。その場合、三角表示のラインを１１０ｍｍの円（加熱に支障のある最小サイズ）がライン内側にちょうど内接するように太く印刷すれば、適正な加熱の最小判定が分かりやすくなるので好適である。また位置確認表示手段３６の表示形状は三角形状に限定されず、後述するような種々のものが選択できる。
【００５４】
以下、実施例５にて他のデザイン表示の例を図８〜図２３を参照しながら順に説明していく。尚、各表示のセンターは全て上述した加熱コイルのセンターと合わせて設定されている。
【００５５】
（実施例５）
図８に示す位置確認表示手段３７は、多数の円形状のループライン３７ａを加熱コイルのセンター（以下、センターと略す。）と同心に配した繰返し表示の１例である。この表示は、従来よりある一重や二重の円表示より最大径が大きくかつ多数あるループライン３７ａが２色交互（印刷は１色でよいがその表示は２色表示となる。）に段階表示され、載置ズレが少しでもあると見合うサイズのループライン３７ａに対する片寄りによって、その方向と共に容易に目視して判定できるし、ズレが大きくなる程より多くのループライン３７ａにまたがった片寄りとなるのでズレとそのズレ量とをさらに直感しやすくなる。
【００５６】
図９に示す位置確認表示手段３８は、センターより４方に向け直線状に連続して拡がるＸ字状のライン３８ａであり、図１０に示す位置確認表示手段３９は、図９のライン３８ａを４５°回転させた十字状のライン３９ａである。これらにおいても、鍋２のわずかの偏心で、ライン終端の突出量のバランスが対応する方向に大きく崩れるので、シンプルな表示でありながら鍋ズレを容易に目視して判定し、センター合わせを確実に行うことができる。尚、Ｘ字状のライン３８ａは不連続な破線であっても良い。
【００５７】
図１１に示す位置確認表示手段４０は、センターと同心に配される多数の円形状のループライン４０ａ、４０ｂ、４０ｃを、３種の異なる色で色分けしたものである。これらにおいては図８に示したループライン３７ａがなす表示の作用効果に加え、ズレ量が大きい程、色の異なる多くの複数のものにまたがって片寄るのでさらに判定しやすくなるという作用効果を発揮し、判定のために全てのサイズのループライン４０ａ、４０ｂ、４０ｃの色を違えなくても、判定しずらくなるズレ量幅単位で色を繰り返し変えるようにすれば、見合うサイズの色の違うラインどうしの間で色の違いを利用した上記判定を、より正確に行うことができる。
【００５８】
図１２に示す位置確認表示手段４１は、図８で示した多数の円形状のループライン３７ａを白抜きのＸ字状のライン４１ａで切欠かれた１ブロックが扇形状をなす多数の円弧４１ｂで表示している。したがって、図８で示した表示による利点と図９に示した表示による利点の両方を兼ね備えているので、より好適である。また図１３に示す位置確認表示手段４２は、円形状のラインを切欠いて多数の円弧４２ｂを残すための白抜きのＸ字状のライン４２ａに代わって十字状のライン４１ａを用いており、同様の利点を有する。
【００５９】
図１４に示す位置確認表示手段４３は、多数の四角状のループライン４３ａをセンターと同心に配している。これら多数のループライン４３ａが、センターより４方に繰り返し拡がることにより、センターに頂点を向ける三角形状の４つのブロックを形成している。この表示により、載置ズレがあると各４つのブロックにおける拡がり量、面積のバランスが対応する方向に大きく崩れるので、ズレとそのズレ量とを直感しやすくなる。また、四角形状の表示がトッププレート６の全域に拡がっており、大鍋や四角形状の焼き物用パンやプレートによっても隠れることがないので好適である。
【００６０】
図１５に示す位置確認表示手段４４は、図１４で示した複数の四角形状のラインを白抜きのＸ字状のライン４４ａで切欠かれた１つのブロックが三角形状をなす多数の直線ライン４４ｂで表示している。したがって、図１４で示した表示による利点と図９に示した表示による利点の両方を兼ね備えているのでより好適であり、また切欠きを十字状のラインにしてもよい。また図１６に示す位置確認表示手段４５は、白抜きのＸ字状のライン４５ａで切欠かれる多数の直線ライン４５ｂ、４５ｃがなす三角ブロックを、上下左右それぞれ２色に色分けして表示したものであり、鍋の載置によって隠れない拡がり量や面積を一目で目視しやすくなるので、判定がより容易になる。
【００６１】
図１７に示す位置確認表示手段４６は、センターと同心に配される多数の円形状のループライン４６ａ、４６ｂ、４６ｃを、３種の異なる色で色分けしたものである。図１１で示した表示に比べてラインは小さい幅でかつそれぞれに隙間があるように印刷されている。この表示においても、図１１で示した表示と同様に、見合うサイズの色の違うラインどうしの間で色の違いを利用した判定が正確に行える。
【００６２】
図１８に示す位置確認表示手段４７は、図１７に示したものと同じく色分けした円形状のループライン４７ａ、４７ｂ、４７ｃで表示し、かつその上に別の色で十字状のライン４７ａを重ねて表示したものであり、円形状のループライン表示と十字状ライン表示の両方の利点が活かせる。また、図１９に示す位置確認表示手段４８は、同じく円形状のループライン４８ａ、４８ｂ、４８ｃで表示し、その上にＸ字状のライン４８ｄを重ねて表示したものであり同様の利点が活かせる上、Ｘ字状のライン４８ｄは、最外側のループライン４８ａを越えて４方に拡がっているので大鍋載置判定にも適している。
【００６３】
図２０に示す位置確認表示手段４９は、図１４で示した表示と同様にセンターと同心に配した四角状のラインの角部をアール形状にしたライン４９ａで表示している。アール形状の四角状ラインとすることにより、Ｘ字状のラインが浮き出たように目視することができるので、四角状ラインをＸ字状のラインで切欠いたり重ね表示することなく、同様の作用効果を奏することができる。
【００６４】
図２１に示す位置確認表示手段５０は、図２０で示したものと同形状のライン５０ａによる表示にさらに十字状のライン５０ｂを重ねて表示したものであり、載置ズレの方向性（十字状とＸ字状）をより目視しやすくなるので好適である。
【００６５】
図２２に示す位置確認表示手段５１は、センターと同心に配される多数の四角形状（角部がアール形状）のライン５１ａ、５１ｂ、５１ｃを、３種の異なる色で色分けして表示している。図２０で示した表示が４方に繰り返されて色分けされて分かりやすくなると共に、円形状のラインを色分けした図１１と図１７に示した表示と同様の利点を活かせる。
【００６６】
図２３に示す位置確認表示手段５３は、センターと同心に配された円形状のループライン５３ａと、センターより等距離のコーナー４箇所に配される点５３ｂとを組合せて表示したものである。この組合せ表示によれば、通常の鍋２はループライン５３ａを用いて載置し、大きな鍋２をトッププレート６上に載置したときには、コーナー４箇所にある点５３ｂは隠れることがなく、その点５３ｂと鍋２間の距離のバランスを目視して、鍋２の大きさや形状を調理者が正確に判定することができる。また鍋２がセンターに対して偏心している場合には、ループライン５３ａの表示は勿論、その偏心度合に応じて前記距離が偏心に対応して長くあるいは短くなってバランスが崩れ、その片寄り度合を目視して鍋２の載置状態を判定し、トッププレート６上の適正な位置（センター位置）に鍋２を移動することができる。また、ループラインは円形状のほか、仮想線で示すように四角形状のループライン５４や、上記までの実施例で示した各位置確認表示手段と組合せることもでき、それぞれの利点を活かせることができ、両方を色違い表示すれば２つの種類の表示が重なっても分かり易く目視容易となるので好適である。
【００６７】
図２４は、大鍋を載置するためにトッププレート６を最大奥行寸法にした誘導加熱調理器における位置確認表示手段５２を示している。またこの実施例の場合には、加熱コイル（図に斜線で示す。）１も従来と異なり、２つのセンター間の距離が短くなるように設定されている。
【００６８】
従来では、図２５に示すように同じ大きさの鍋が２つ載置できるように加熱コイル１の位置が決められていた。そこで仮に、加熱コイル１のセンター１Ｓに合わせて図８に示したような多数の円形状のループライン５５ａからなる位置確認表示手段５５を設けても、次のような問題が生じる。つまりトッププレート６の載置可能面積いっぱいに大鍋を載置した場合に、大鍋の鍋底２ａのセンター２Ｓと、加熱コイルのセンター１Ｓがズレてしまい適正な位置に載置できない。
【００６９】
そこで図２４に示すように、加熱コイル１のセンター間距離を短く設定し、かつそれに合わせて位置確認表示手段５２のセンター間の距離も短く設定し、その各センターと同心になるように多数の円形状のループライン５２ａを配している。つまり、片方の位置確認表示手段５２のセンターをもう一方の位置確認表示手段５２のセンターに近付けたため、２つのそれぞれのコンロ用のループライン５２ａ、５２ａが内側で少し重なるように表示される。このことによって、通常の鍋を載置した場合には、従来の一重の円表示より最大径が大きくかつ円形状の多数のループライン５２ａが周辺に繰り返して拡がって表示されるためにセンター合わせがしやすくなることは勿論、トッププレート６の載置可能面積いっぱいに大鍋を載置した場合でも、加熱コイル１のセンター１Ｓと鍋底２ａのセンター２Ｓとが合った状態になるので、効率良く適正な位置に大鍋を載置することができる。
【００７０】
【発明の効果】
本発明は既に説明したように、載置物の状態の判定を各光検知手段の各位置での検知の有無より行うことにより、トッププレート上の状態の判定を各位置での検知値の違いにより行うことができると共に、調理中に加熱調理体を取外した場合の判定は、そのとき生じる載置時の状態からの一部または全体の検知結果の反転を伴い全て同じ検知状態になる変化から的確に行うことができ、各判定のためにインバータ回路を駆動しないので発振素子に負担をかけることなく、また無用な電磁波を発することなく適正な加熱調理体を載置した場合にはすぐに加熱を再開でき、使い勝手およびコンロの安全性を向上させることができる。
【００７１】
上記制御手段によって、判定結果の外部報知、加熱コイルへの入力電流の制御の少なくとも１つの措置を行うようにすれば、ブザー音や光などの外部報知によって調理者に異常を気付かせやすくし、措置を促せるので、調理者は加熱調理体の載置忘れや載置ズレと措置の必要に気付きやすく、適正な位置に加熱調理体を載置し直したり、載置し直されない場合は、載置ズレのまま加熱されることのないように電流制御により加熱出力を減少させたり、電流供給遮断により加熱出力を停止したりするなど速やかな対応ができ、措置が遅れたりなされなかったりするのを防止することができる。
【００７２】
上記複数箇所を、加熱コイルの中心から周辺に向けた複数の拡がり区域とし、かつ加熱コイルの中心およびそれを同心とする環状の各拡がり域での複数箇所とすれば、加熱コイルの中心に同心に載置された加熱調理体に対しては、その大きさや形状を判定することができ、また加熱調理体の中心が加熱コイルの中心に対して偏心した加熱調理体に対しては、その偏心度合を判定することができると共に、ナイフやフォークと云った特殊な形状物を含む過小物の判定もできるし、光を検知する光検知手段を持った場合ではトッププレート上の汚れを判定でき、光として反射光を検知する場合では、照射から検知までの時間により加熱調理体の底の反りによる浮きも判定できる。
【００７３】
上記発明において既に説明したように、状態判定手段の判定結果と負荷判定手段の判定結果とに基づいて制御するようにすれば、負荷判定手段により負荷が小さいと判定された場合、その判定結果だけでなく状態判定手段の判定結果も合わせて制御手段の措置を採ることにより、状態判定手段と負荷判定手段の両方で適正に判定することにより、負荷だけで判定した場合に、加熱可能な加熱調理体なのに加熱を停止させたり、逆にいくら加熱しても熱くならないのに加熱を続行して発振素子を損傷させてしまう不都合を解消することができる。
【００７４】
また本発明は以上説明したように位置確認表示手段が設けられているので、加熱コイルの中心と同心に加熱調理体が載置された場合には、加熱調理体によって隠れない位置確認表示手段の拡がり量、面積のバランスを目視して、加熱調理体の大きさや形状を調理者が正確に判定することができると共に、加熱調理体が加熱コイルの中心に対して偏心している場合には、位置確認表示手段の拡がり部分の片寄度合を目視して加熱調理体の載置状態を判定し、トッププレート上の適正な位置つまり加熱コイルと加熱調理体の底との同心位置に加熱調理体を載置して加熱調理を行うことができるので、使い勝手がよくなると共に、載置ズレによる加熱調理体の温度検知不良から生じる加熱調理体の過発熱を防止できるので、使用およびコンロの安全性も向上する。
【００７５】
また別な位置確認表示手段として、トッププレート上における加熱コイルの中心より等距離のコーナー４箇所に、点状のものを設ければ、大きな加熱調理体をトッププレート上に載置したときに、コーナー４箇所にある位置確認表示手段と加熱調理体間の距離のバランスを目視して、加熱調理体の大きさや形状を調理者が正確に判定することができる。また加熱調理体が中央位置に対して偏心している場合には、その偏心度合に応じて前記距離が偏心に対応して短くなり、その狭小度合を目視して加熱調理体の載置状態を判定し、トッププレート上の適正な位置つまり加熱コイルと加熱調理体の底との同心位置に加熱調理体を移動してから加熱調理を行うことができるので、使い勝手がよくなると共に、載置ズレによる加熱調理体の底の温度検知不良から生じる加熱調理体の過発熱を防止できるので、使用およびコンロの安全性も向上する。
【００７６】
上記発明の点状の表示に加え、加熱コイルの中心を同心とする環状の位置確認表示手段または、トッププレート上のほぼ全域に、加熱コイルの中心より３方以上に、連続・不連続・繰返しの少なくとも１つの共通した態様を持って拡がる位置確認表示手段を設け、これら各位置確認表示手段のいずれか一方と上記点状の位置確認表示手段を組合せて表示することにより、両方の利点を活かせることができると共に、両方を色違い表示すれば２つの種類の表示が重なっても分かり易く目視容易となるので好適である。
【図面の簡単な説明】
【図１】本発明の実施例１の全体構成を示す縦断面図。
【図２】同実施例１の制御ブロック図。
【図３】同実施例１の要部を拡大して示す縦断面図。
【図４】同実施例１の要部を上方から見た概略平面図。
【図５】本発明の実施例３の要部を概略して示し、（ａ）はトッププレート上に汚れがない状態で示す縦断面図、（ｂ）はトッププレート上に汚れがある状態で示す縦断面図。
【図６】本発明の実施例４の全体を概略して示す斜視図。
【図７】同実施例４の要部を上方から見た概略平面図。
【図８】同実施例５における位置確認表示手段を示す概略平面図。
【図９】位置確認表示手段の他の実施例を示す概略平面図。
【図１０】位置確認表示手段の他の実施例を示す概略平面図。
【図１１】位置確認表示手段の他の実施例を示す概略平面図。
【図１２】位置確認表示手段の他の実施例を示す概略平面図。
【図１３】位置確認表示手段の他の実施例を示す概略平面図。
【図１４】位置確認表示手段の他の実施例を示す概略平面図。
【図１５】位置確認表示手段の他の実施例を示す概略平面図。
【図１６】位置確認表示手段の他の実施例を示す概略平面図。
【図１７】位置確認表示手段の他の実施例を示す概略平面図。
【図１８】位置確認表示手段の他の実施例を示す概略平面図。
【図１９】位置確認表示手段の他の実施例を示す概略平面図。
【図２０】位置確認表示手段の他の実施例を示す概略平面図。
【図２１】位置確認表示手段の他の実施例を示す概略平面図。
【図２２】位置確認表示手段の他の実施例を示す概略平面図。
【図２３】位置確認表示手段の他の実施例を示す概略平面図。
【図２４】従来とは異なる配置の加熱コイルおよびそれに合わせた位置確認表示手段の実施例を示す概略平面図。
【図２５】従来の加熱コイルと位置確認表示手段の配置を示す概略平面図。
【符号の説明】
１　加熱コイル
１Ｓ　センター（加熱コイルの中心）
２　鍋（加熱調理体）
３　光検知手段
４　状態判定手段
５　制御回路（制御手段）
６　トッププレート
７　負荷判定手段
３６〜５４　位置確認表示手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an induction heating cooker that supplies a high-frequency current to a heating coil to generate heat in a cooking body.
[0002]
[Prior art]
Generally, an induction heating cooker converts a direct current into a high-frequency current using an inverter circuit, generates a high-frequency magnetic flux, induces an eddy current in a load (heating cook) magnetically coupled with the heating coil, and uses the Joule heat to generate the eddy current. The load itself is heated to heat the object to be cooked. If a small object such as a knife or a fork is mistakenly placed on the top plate on which the cooked body is placed, be careful not to generate heat as an inappropriate load, or remove the normal load from a pot or the like. 2. Description of the Related Art In order to protect an inverter circuit, a device provided with a load determining means for determining whether or not a load is appropriate has been known. Specifically, a small object is detected from the relationship between the input current, the resonance current, the resonance voltage, and the like to the inverter circuit, and whether or not there is a cooked body is detected from the input current. Heating is stopped as soon as it is determined that it is appropriate or not, and then intermittent oscillation is continuously performed, and heating is restarted when it is determined that an appropriate cooked body is placed.
[0003]
[Problems to be solved by the invention]
However, in the determination by the above-described conventional load determination means, it is not possible to accurately determine the suitability of the heated cooked body, which is the load, only when the load is the same. This is because the load when the electric resistance value or the degree of magnetism of the cooked body is low may be the same as the load having a high electric resistance value or the degree of magnetism is small even if the cooked body is large. Are indistinguishable and extremely ambiguous. In addition, in the determination of only such a load, it is not possible to determine the displacement of the heating cooked body in addition to the size and shape of the bottom. Therefore, the only way to continue cooking the cooked body at an appropriate position is to rely on human judgment and measures.
[0004]
In order to cope with this, a single circle or a double circle concentric with the heating coil is displayed in the placement area of the heating cooker on the top plate so that the eccentric state of the placed cooker can be easily understood. However, even in this case, the deviation that occurs during cooking is apt to be overlooked, and in the conventional display, a large circle has a large difference from a small load, and a small circle is easily hidden by the load. Although it is adjusted to a large load, it is hidden by a large load, and it is difficult to recognize the presence or absence of eccentricity. As a result, it sometimes happens that heating cooking is continued at an improper position due to a mounting displacement before heating cooking or movement due to vibration during heating cooking. In such a state, the temperature is not accurately detected, and a problem such as overspillage occurs due to overheating. In the case of cooking fried foods, a large amount of oil may be ignited, so safety measures have been a problem. Further, in such a state, the heating is stopped by the load determination.
[0005]
In addition, since the judgment by the load judgment means makes the driving of the inverter circuit an indispensable element, there is a problem that the judgment takes time. In addition, in order to determine the empty detection when the cooked body is removed during the cooking, the current must be supplied to the inverter circuit continuously or intermittently, and the current is supplied in a state where there is no load. When supplied, the load on the oscillating element is large, and when it is intermittent, cooking cannot be resumed immediately even if an appropriate cooked body is placed thereafter, resulting in poor usability.
[0006]
Accordingly, the present invention provides an induction heating cooking system that improves the usability, use and safety of a stove by facilitating heating cooking at an appropriate position by instantaneous and accurate automatic or human judgment without the need for driving an inverter circuit. The purpose is to provide a vessel.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an induction heating cooker according to the present invention is directed to an induction heating cooker in which a high-frequency current is supplied to a heating coil to generate heat in a heating cooker. From the light incident from, or the light emitted from the lower surface of the top plate at the plurality of locations, a light detection unit that detects light reflected on the bottom surface of the cooked body, by a combination of a plurality of detection results by the light detection unit, It is characterized by comprising a state determining means for determining the shape and state of the mounted object or a state on the top plate, and a control means for performing control according to the determination result of the state determining means.
[0008]
According to the above invention, the light detecting means detects light incident on a plurality of locations on the top plate or light irradiated from the lower surface of the top plate at the plurality of locations, and a combination of a plurality of detection results at this time is used for cooking. From the correlation that changes depending on the size of the body, the shape of the bottom, the shape of the object such as warpage, the state of the object placed such as misalignment, and the state on the top plate, the state of the object placed such as a pan, that is, Presence / absence, misalignment of the cooked body before and during heating cooking, size of the cooked body, placement of small objects such as knives and forks on the top plate, and state of dirt on the top plate, etc. The judging means can judge instantaneously and accurately. The determination of the state of the mounted object is performed based on the presence or absence of detection at each position of each light detection unit, and the determination of the state on the top plate can be performed based on the difference in the detection value at each position. In addition, the determination when the cooked body is removed during cooking can be accurately performed based on a change that occurs at that time and in which all or a part of the whole detection result from the state at the time of placing is inverted to the same detection state. Yes, the inverter circuit is not driven to determine the presence / absence of mounting, so that heating is restarted immediately when the proper cooked body is mounted without placing a burden on the oscillating element and emitting unnecessary electromagnetic waves. it can. Therefore, usability and stove safety can be improved.
[0009]
In the above invention, if the control means performs at least one measure of external notification of the determination result and control of the input current to the heating coil, the control unit causes the cook to notice the abnormality by the external notification such as a buzzer sound or light. It is easy for cookers to notice that the cooker has forgotten to place the cooked body or that it has been misplaced, and that it is necessary to take measures, and that the cooker is not placed or placed again in the proper position. In such a case, it is possible to take prompt measures such as reducing the heating output by current control or stopping the heating output by interrupting the current supply so that heating is not performed with the mounting displacement, and measures are not delayed. Can be prevented. It is preferable that the external notification be at least one of a display and a warning sound.
[0010]
In the above invention, the plurality of locations are directed from the center of the heating coil on the top plate (the center of the heating coil wound in a substantially circular shape when the top plate surface is overlooked from the mounting side of the cooked body). If there are a plurality of spread areas and a plurality of places in the center of the heating coil and each of the annular spread areas concentric with the center of the heating coil, the heating cooked body placed concentrically on the center of the heating coil is Is located at the center side, and undetected detection points are located at the corresponding points on the surrounding area according to the size and shape of the cooked body, the number of such areas, the number of existing places The size and shape of the cooked body can be determined from the correlation that the position and the position change. Further, if the center of the cooking body is eccentric with respect to the center of the heating coil, the detected portion and the non-detected portion are offset in opposite directions depending on the degree of the eccentricity. The degree of eccentricity of the cooked body can be determined from the degree of deviation and the correlation of the change in the state. In addition, it is possible to determine an undersized object including a specially shaped object such as a knife or a fork. Further, in the case where a light detecting means for detecting light as a signal is provided, especially when the detected value is equal to or more than a predetermined value indicating the presence or absence of a mounted object (depending on the signal to be detected), dirt on the top plate is contaminated. In the case where reflected light is detected as light, it is also possible to determine the floating due to the warpage of the bottom of the cooked body based on the time from irradiation to detection.
[0011]
In addition, it is preferable to arrange the plurality of locations from the center toward three or four sides from the center, since the above determination can be made at a limited number of detection locations.
[0012]
In the above invention, there is provided a load determining means for determining a load from at least one of an input current, an input voltage, a resonance current, and a resonance voltage to the heating coil, and the control means determines the determination result of the state determining means and the determination of the load determining means. If the control is performed based on the result, if the load is determined to be small by the load determining means, by taking the measures of the control means together with the determination result of the state determining means as well as the determination result, for example, Even when it is determined that the load is small with the heating cook body having a low magnetic degree, when the state determination unit determines that the bottom of the heating cook body is small, the heating output may be increased by the current control to continue the heating. Conversely, when it is determined that the bottom of the cooked body is large, heating can be disabled and the heating can be stopped by interrupting the current supply. In this way, by appropriately determining with both the state determining unit and the load determining unit, when the determination is made only with the load, the heating is stopped even though the heating is possible, or conversely, even if the heated cooking body is heated, it is still hot. It is possible to eliminate the inconvenience of continuing heating and damaging the oscillation element. Also in this case, after the heating is stopped, the inverter circuit is controlled so that reheating cannot be performed until the state determination unit determines that the heating cooker has been removed and a proper heating cooker has been placed. Of the oscillation element can be prevented from being inconvenienced by the driving.
[0013]
Further, in order to achieve the above object, the induction heating cooker of the present invention has at least one common mode of continuous, discontinuous, and repetitive in almost all areas on the top plate, at least three sides from the center of the heating coil. It is characterized in that a position confirmation display means which is extended by being held is provided.
[0014]
According to the above invention, when the cooking body is placed concentrically with the center of the heating coil, the center side of the position confirmation display means is hidden, and the position confirmation display means which is not hidden by the cooking body is provided by the heating confirmation body. Spreading appears in a common manner in the peripheral area according to the size and shape, and the spread amount and the area balance are visually observed, and the cooker can accurately determine the size and shape of the cooked body. it can. Further, when the cooking body is eccentric with respect to the center of the heating coil, position confirmation display means that is not hidden by the cooking body appears in a direction corresponding to the eccentricity in accordance with the degree of the eccentricity. The cooker can accurately determine the eccentricity of the cooked body by visually checking the degree of deviation. As described above, the cooker visually determines the mounting state of the heating cooked body by visually checking the spread portion of the position confirmation display means that is provided without being hidden by the heated cooked body by being provided in almost the entire area of the top plate. Since the cooking can be performed by placing the cooking body at the appropriate position above, that is, at the concentric position between the heating coil and the bottom of the cooking body, the ease of use is improved, and the temperature of the cooking body due to the mounting displacement is improved. Since overheating of the cooked body caused by the detection failure can be prevented, the safety of use and the stove is also improved.
[0015]
In order to achieve the above object, the induction heating cooker according to the present invention is characterized in that point-like position confirmation display means are provided at four corners on the top plate, which are equidistant from the center of the heating coil. I do.
[0016]
According to the invention, when a large cooked body is placed on the top plate, the balance of the distance between the position confirmation display means at four corners and the cooked body is visually observed, and the size of the cooked body and The shape can be accurately determined by the cook. Further, when the cooking body is eccentric with respect to the center of the heating coil, the distance becomes longer or shorter corresponding to the eccentricity depending on the degree of eccentricity, the balance is lost, and the degree of deviation is visually observed. It is possible to judge the mounting state of the cooked body, move the cooked body to an appropriate position on the top plate, that is, a concentric position between the heating coil and the bottom of the cooked body, and then perform the heating cooking, so that it is easy to use. And the overheating of the cooked body caused by the temperature detection failure of the bottom of the cooked body due to the displacement can be prevented, so that the safety of use and the stove is also improved.
[0017]
In the above invention, at least one of continuous, discontinuous, and repetition is provided over substantially the entire area of the top plate, in an annular position confirmation display means arranged concentrically with the center of the heating coil, or at least three directions from the center of the heating coil. By providing position confirmation display means that spreads in a common manner, and combining and displaying any one of the position confirmation display means and the point-like position confirmation display means, both advantages can be utilized. It is preferable to display both in different colors, because even if two types of displays are overlapped, they can be easily understood and visually recognized.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
In the induction heating cooker of the present invention, as shown in the overall configuration diagram of FIG. 1, a high-frequency current is applied to a heating coil 1 to cause a pan (heating cooked body) 2 to generate heat, and the pan 2 is placed thereon. Light detecting means 3 for detecting light incident on a plurality of locations on the top plate 6 or light reflected from the bottom surface of the pan 2 by light irradiated from the lower surface of the top plate 6 at the plurality of locations; A state determination unit 4 for determining the state of a placed object such as the pan 2 or a small object or a state on the top plate 6 based on a combination of a plurality of detection results, and a control circuit for performing control according to the determination result of the state determination unit 4 ( (Control means) 5.
[0019]
The signal detected by the light detecting means 3 is an optical signal such as a radio wave, a sound wave, an infrared ray, an ultraviolet ray, etc., which is straight and detectable. The control circuit 5 includes, as shown in FIG. 2, a load determination unit 7 that detects and determines a load from at least one of an input current, an input voltage, a resonance current, and a resonance voltage to the heating coil 1 in the inverter circuit 16. Control is performed based on both the determination result of the determination unit 4 and the determination result of the load determination unit 7, and the various status determination results are externally reported by the display unit 10 and the notification unit 11, and current control and current supply cutoff are performed. . The external notification may be performed by both the display unit 10 and the notification unit 11, or may be performed by either one of them. The cooked body may be any one that can be electromagnetically cooked, such as a pot 2 or a roasted plate or a roasted pan, but even if the load determiner 7 determines that the pot 2 has a low load, the state determiner 4 determines that the pot 2 is small. When it is determined that the pot is a pan, the heating output is increased to enable heating.
[0020]
An embodiment basically configured as described above will be specifically described below as Example 1 with reference to FIGS. 1 to 4.
[0021]
(Example 1)
In the induction heating cooker according to the first embodiment, as shown in FIG. 3, the top plate 6 is made of a transparent material such that a plurality of portions facing the light detecting means 3 disposed below the top plate 6 have light transmittance. The lower surface thereof is masked by applying a coloring agent to portions other than the plurality of opposing portions, and divided into a transparent portion 6a and a coloring portion 6b.
[0022]
The light detecting means 3 mainly detects light traveling straight at a plurality of positions on the top plate 6 as described above, and controls the control device 27 such as the oscillating element 15 so as to maintain a constant distance from the lower surface of the top plate 6. The light shielding spacer 33 provided on the shielding substrate 17 that shields the light is disposed inside the cylindrical portion. Further, as shown in FIG. 4, the plurality of locations where the light detection means 3 are arranged are, as shown in FIG. 4, from the center of the heating coil 1 on the top plate 6 to the periphery (in the first embodiment, there are four, ), That is, a plurality of areas extending from the center of the heating coil 1 wound in a substantially circular shape to the periphery when the top plate 6 is overlooked from the side on which the pan 2 is placed. It is a spreading area, and the center of the heating coil 1 (hereinafter, referred to as a center 1S) and a plurality of locations in each of the concentric annular spreading areas.
[0023]
In the light detecting means 3 of the first embodiment, the center 1S of the heating coil 1 and the center 1S of the heating coil 1 are linearly spread from the center 1S in four directions at equal intervals. The light detected by the light detecting means 3 is the light that is transmitted through the transparent portion 6 a of the top plate 6 and has a light source below the top plate 6. Alternatively, light that is reflected by the incident light may be used.
[0024]
In FIG. 1, a front case 18, a bottom plate 19, and a back plate 20 are provided as a main body case in which two heating portions are formed by two heating coils 1 and have an overall rectangular box-shaped appearance. The top plate 6 is bonded and fixed to the upper surface opening formed by the back plate 20 while being sealed by a seal member 21. On the front panel 18, an operation / display panel having an operation switch 22 serving as an input unit of the operation unit 9 and a display unit 23 serving as an output unit of the notification unit 11 shown in FIG. The operation switch 22 and the display unit 23 are mounted on the operation board 24. The operation portion and the main body portion containing the control device 27 are separated by a partition plate 25 having a front surface standing upright and extending rearward.
[0025]
At the upper part of the main body case, two heating coils 1 each having a circular coil base 26 are arranged so as to face the lower surface of the top plate 6. Has a temperature detecting means 8 for detecting the temperature of the bottom surface of the pan 2. In addition, an inverter circuit 16 (FIG. 2) for supplying a high-frequency current to the heating coil 1 and a control device 27 that constitutes a control circuit 5 for oscillating and controlling the inverter circuit 16 are built in a lower portion of the main body case. ing. In these control devices 27, the oscillation elements 15 for the left and right heating coils 1 are separately mounted on a control board 29 on the left and right sides on a support member 28 integrally formed in an upper and lower two-stage shape. Heat sinks 31 are attached so that the cooling fan 30 attached to the rear end of the plate 25 can efficiently receive the airflow.
[0026]
The induction heating cooker configured as described above will be specifically described with reference to the control block diagram of FIG. A commercial power supply 12, a rectifying circuit 13 for rectifying and smoothing the commercial power supply 12, and an inverter circuit configured to receive an output of the rectifying circuit 13 by a resonance capacitor 14 and a heating coil 1 and connect the output to an oscillation element 15. A control circuit 5 for oscillating and controlling the oscillating element 15 and taking measures according to the judgment results of the state judging means 4 and the load judging means 7, and a light detecting means for inputting and outputting signals to and from the control circuit 5 3, a temperature detecting means 8, an operating means 9, a display means 10, a notifying means 11, and an ambient lightness detecting means 32 described later.
[0027]
As a heating cooking mechanism, an induction heating cooker causes a direct current to flow through a resonance circuit by an oscillating element 15 to generate a high-frequency magnetic flux to induce an eddy current in a load (pan 2) magnetically coupled to the heating coil 1, and to generate a joule. The load itself is heated by the heat to heat the food in the pan 2. Load determining means 7 is provided to determine whether the load is appropriate. Based on this determination, if a small object such as a knife or a fork is erroneously placed on the top plate 6 on which the pan 2 is placed, heating is stopped so that it is not generated as an inappropriate load, After removing the pan 2 determined to be, the control is performed so that heating is not restarted until it is determined that an appropriate pan 2 is placed.
[0028]
In the first embodiment, in addition to this, control is performed based on the determination result of the state determination unit 4. However, the state determination unit 4 is used to control the state of the placed object, that is, whether the pan 2 is placed or not, A specific example of determining the placement displacement, the size and shape of the bottom of the pan 2, the detection of small objects such as knives and forks, and the determination of dirt on the top plate 6 will be described below.
[0029]
As shown in FIG. Thirteen phototransistors 1 to 13 are arranged at equal intervals in four directions linearly from the center 1S of the heating coil 1. Among these light detecting means 3, the one located at the center position is "1", and those arranged on a circle having a diameter of 110 mm (the size of the pot 2 having a problem in heating) are "2", "5" and "8". "11", and those arranged on the surrounding circles are "3", "6", "9" and "12", and those arranged according to the maximum outer diameter of the surrounding heating coil 1 are "4". "7""10""13". As described above, the lower surface of the top plate 6 is masked except for the portion above the cylindrical portion in the light shielding spacer 33 in which the light detecting means 3 is disposed so as to easily detect the incident light traveling straight.
[0030]
A list of the determination results of various states (up to 13 types) is shown below (Table 1), and using this list and FIG. 4, the detection by the light detection means 3 and the determination of the state determination means 4 based on the detection are concrete. Will be described.
[0031]
[Table 1]

First, in the state a, all the light detection means 3 of “1 to 13” detect light. That is, since the incident light is transmitted through the transparent portion 6a of the top plate 6 and the pan 2 is not placed, it is determined that "there is no pan". In state b, only “1” of the center 1S has not detected light. In other words, since the transparent portion 6a facing the light detecting means 3 of "1" is closed by any mounted object, it is determined that "a small object or a small pan with a bottom diameter of 110 mm or less is placed". You.
[0032]
In the state c, since only “2” eccentric to the right side of the center 1S has not detected light, it is determined that “a small object or the small pot is placed”. In state i, “1”, “2”, “5”, “8”, “9”, and “11” have not detected light. That is, it is considered that the pot 2 is placed at a position eccentric to the left side slightly from the center, and it is determined that the pot 2 is misaligned. In the state j, “1”, “2”, “5”, “6”, “8”, “9”, and “11” do not detect light, that is, the pot 2 having a slightly larger bottom diameter than the state i is slightly larger than the center. It is regarded as being placed at a position eccentric to the left side, and is determined to be “pan shift”. As described above, if the pot 2 is eccentric with respect to the center 1S, the detected part and the non-detected part are offset in directions opposite to each other according to the degree of eccentricity. The eccentricity of the pot 2 can be determined from the degree of deviation or the correlation with which the state changes.
[0033]
Although not shown in this list, when the light detecting means 3 arranged at equal distances from the center 1S to four directions does not detect light, the pan is placed at an appropriate position. "Yes", and the size and shape of the pot bottom are also determined at the same time. As described above, for the pot 2 concentrically placed on the center 1S, a detection point for detecting this exists on the center side, and a detection point for no detection exists in the periphery corresponding to the size and shape of the pot 2. The size and shape of the pot 2 can be determined from the correlations in which there are corresponding locations on the area and the number of existing areas and the number and location of the existing areas change.
[0034]
According to the first embodiment described above, the detection result obtained by detecting the presence or absence of the incident light by the light detection means 3 changes according to the state of the placed object such as the size, the shape, and the displacement of the pan 2. Accordingly, the state determination means 4 can instantaneously and accurately determine whether or not the pan 2 is placed, the displacement of the pan 2 and the size of the pan bottom, and the placement of small items on the top plate 6. In addition, when the pot 2 is removed during cooking, it is possible to accurately perform the change from the previous state, which is accompanied by a change in a part or the whole of the detection result, and the same detection result is obtained. The determination is made not by the load determination means 7 but by the light detection means 3 and the state determination means 4 which do not require the driving of the inverter circuit 16, so that the appropriate determination can be made without burdening the oscillation element 15 and emitting unnecessary electromagnetic waves. When the pan 2 is placed, heating can be resumed immediately, so that usability and stove safety can be improved.
[0035]
Further, the state determination unit 4 can determine not only the presence or absence (1 or 0) of the light detection by the light detection unit 3 but also the dirt on the top plate 6 based on the difference in the detection value. For example, a predetermined value that is larger than the threshold value for determining whether there is a pan is set as the threshold value for determining that there is no pan, and a difference between the maximum detection value of the light detection means 3 of “1 to 13” within a range of a detection value that is larger than that Thus, the degree of contamination can be determined. At this time, a surrounding lightness detecting means 32 for detecting the surrounding lightness is provided at a position different from the top plate 6, and the surrounding lightness level is determined from the output value from the surrounding lightness detecting means 32. It is preferable to correct each threshold value in the light detecting means 3. Since the detection value of the light detection means 3 changes depending on the surrounding brightness, the detection value of the light detection means 3 is changed into three levels, that is, level 1 → “pan is placed”, level 2 → “pan is placed”. No "and level 3 →" the top plate 6 is dirty ", and correcting each threshold value according to each level enables more accurate determination.
[0036]
Although the detection of the state of the mounted object and the detection of the state of the top plate have been described separately, it is also possible to make a comprehensive determination by combining a plurality of both detection results.
[0037]
Further, although the above-described light detecting means 3 detects the incident light, the light detecting means 3 may detect the reflected light, and the reflected light detecting method may more accurately determine the size of the pot bottom than the above-described incident light detecting method. Can be detected. This is because, depending on the overall shape of the pan 2 (a pan having a large difference between the maximum diameter and the diameter of the pan bottom), the pan bottom determination may be ambiguous. However, even in this case, it is possible to maintain the accuracy of the incident light detection method by making a comprehensive determination in combination with the load determination means 7. Also, the load determination and the dirt determination can be used together. If there is a portion where the load is determined to be small and no light is detected, the dirt and the non-magnetic material are determined depending on a difference in the detection position and the detection value. Can be clearly distinguished.
[0038]
By the way, in the induction heating cooker, the pan 2 may vibrate due to the natural vibration and the magnetic field repulsion, and the pan 2 may be displaced due to the vibration even at an appropriate position at the start of the cooking. Therefore, when the placement deviation is detected and determined by the light detection means 3 and the state determination means 4 during the heating cooking, the oscillation frequency at that time is stored, and when the heating is performed next time, the load determination means 7 and the state determining means 4 determine that the pot 2 has the stored value, thereby avoiding oscillation in the vicinity of the stored oscillation frequency and heating to surely prevent the displacement due to vibration. Can be. The control circuit 5 performs at least one of measures such as external notification of the determination result, current control, and current supply interruption, in addition to the oscillation frequency control based on the determination result of the state determination unit 4. The cook notices by external notification that he or she has forgotten to place the pan 2 or misplaced it and needs to take measures. If the cooker does not re-place the pan 2 in an appropriate position, or if it is not re-placed, the cooker remains misplaced. It is possible to take prompt measures such as reducing the heating output by current control or stopping the heating output by interrupting the current supply so as not to cause heating, and prevent measures from being delayed or not taken. it can.
[0039]
If it is determined that the pan 2 is misplaced (eccentric or protruding), it is preferable to correct the detected temperature detected by the temperature detecting means 8 according to the degree. Since the temperature detecting means 8 is disposed on the lower surface of the top plate 6 at the center position of the heating coil 1, the pan 2 is displaced during the cooking and the center of the bottom is no longer located above the temperature detecting means 8. In addition, an error may occur between the actual temperature of the pan 2 and the detected temperature, and the error may cause the pan 2 to overheat and cause a problem such as blow-off. This error is highly likely to lead to an accident in the boiled food control and fried food modes, so it is essential to take safety measures.However, by correcting the detected temperature, the temperature detection can be performed even when the pan 2 is not at the proper position. Accurately, it is possible to prevent the above-mentioned problem due to the deviation of the detected temperature.
[0040]
(Example 2)
Although the light detecting means 3 of the first embodiment detects the incident light transmitted through the top plate 6, a light source is provided below the top plate 6, and light emitted from the light source is reflected on the lower surface of the top plate 6. Light may be detected, and in that case, floating due to warpage of the pot bottom, that is, the shape of the pot bottom can also be detected.
[0041]
In the second embodiment, as an example of the state determination of the placed object and the current control thereof, the floating of the pot bottom is determined using the reflected light detection method, and the case where the control is performed based on the determination result is taken as an example of the fried food mode. Description will be made without using the drawings. In addition, since the error of the detected temperature of the temperature detecting means 8 described above also occurs due to the floating of the bottom of the pan other than the displacement of the pan, it is needless to say that the correction of the temperature detecting means 8 is also suitable in this case.
[0042]
The deep-fried food mode is adopted as one of the functions of a home induction heating cooker equipped with an inverter circuit, and is a dedicated automatic heating control for performing deep-fried food such as a tempura. When the user selects that mode and sets the desired oil temperature, automatic heating is performed up to the set temperature and heating control is performed so as to maintain the set temperature. If the oil is heated above a certain temperature, it may ignite. However, the cause of the abnormal heating of the oil is when the amount of oil is less than the manufacturer's minimum set value (500 g) or when the bottom of the pot is warped. Floating (only a warp of about 2 mm causes overheating without being able to detect the actual temperature of the pan) and the like. Manufacturers have responded to the problem of floating the bottom of the pan by attaching a special pan for frying as an accessory.
[0043]
Therefore, in the second embodiment, the shape (floating) of the pot bottom is determined by the light detecting means 3 (reflected light detecting method), and when the determined shape matches the shape of the dedicated pot, the characteristics (floating, specific heat, Heating control that takes into account ease of use taking into account the standard capacity, etc.). If they do not match (they are not dedicated pots), the heating output is reduced and heating control is prioritized for safety (safety is given priority over ease of use). Further, safety can be further improved by performing temperature detection and oil amount determination in consideration of the determined shape of the pot bottom.
[0044]
Since the load characteristics are determined for each pan, if the load characteristics of the dedicated pan are stored in advance, by comparing whether or not the load of the pan being heated is equal to the stored value, whether or not the pan is a dedicated pan is determined. Can be determined. However, just because the load is the same, it cannot be correctly determined whether or not the pot is a dedicated pot. This is because the same load may be applied to a pot that is larger than the dedicated pot and has a lower magnetic degree and electric resistance. Therefore, by combining the determination result of the load determining means 7 with the determination result of the state determining means 4 (determination based on the detection of the size of the bottom of the pan), it is possible to accurately determine whether or not the pan is a dedicated pan.
[0045]
Further, when it is determined that the pan is a dedicated pan, heating is performed at a predetermined constant output, and when it is determined that the pan is not a dedicated pan, it is preferable that the heating be corrected to an output smaller than the constant output. Since it is not a dedicated pot, there is a possibility that there is a float on the bottom of the pot, so heat it slowly with a low output for safety. Further, depending on the size of the pot bottom (the larger the pot bottom is, the more likely the pot bottom is lifted), the degree of correction can be reduced.
[0046]
(Example 3)
The third embodiment shown in FIG. 5 employs a reflected light detection method as in the second embodiment, and includes a light source 34 below the top plate 6 and a light detecting means 3A for detecting the reflected light. Note that since the third embodiment is intended to particularly detect blow-off stains during cooking, the light source 34 is arranged in an annular shape around the heating coil 1 and irradiated for several seconds after the completion of heating.
[0047]
As shown in FIG. 5A, if there is no dirt on the top plate 6, the light emitted from the light source 34 passes through the top plate 6 as it is, so that the light detecting means 3A does not detect the light. If there is dirt on the top plate 6 as shown in (3), the light emitted from the light source 34 is reflected on the lower surface of the dirty top plate 6, and the reflected light is detected by the light detection means 3A, and based on the detection result. State determination means 4 determines that the surface is dirty. Then, when it is determined to be dirty, the buzzer sounds at the notification means 11 or the lamp is blinked at the display means 10 to alert the cook. These notifications allow the cook to notice the dirt and wipe off the dirt on the top plate 6, thereby preventing a decrease in the heating efficiency due to the dirt and erroneous detection of the light detecting means, and at the same time, preventing the pests from approaching. Use can be achieved.
[0048]
(Example 4)
As described in the first embodiment, in order to safely and efficiently perform heating cooking in the induction heating cooker, it is necessary to place the pot 2 at an appropriate position in accordance with the center 1S of the heating coil 1 without displacement. In the first embodiment, the placement deviation is detected by the light detection unit 3 and the state is determined by the state determination unit 4. In the fourth embodiment, the position confirmation display as shown in FIGS. By providing the means 36, the cooker can visually determine the placement state of the pan 2 by visually checking the display.
[0049]
The position confirmation display means 36 is formed so as to extend over substantially the entire area of the top plate 6 from the center 1S of the heating coil 1 to three or more sides in at least one common mode of continuous, discontinuous, and repetitive. However, as shown in FIG. 7A, the position confirmation display means 36 according to the fourth embodiment has the same center as the center 1S of the heating coil 1 and has a triangular shape having a side length r of 26 cm or more. And In order to display this triangular shape, a plurality of light emitting elements are configured to be turned on and off by operating a position confirmation switch 35 provided on an operation / display panel as shown in FIG.
[0050]
In the case of the conventional circular display, when a large pot having a diameter of the pot bottom 2a of 26 cm is used, the display is hidden by the pot, and the pot bottom 2a cannot be accurately placed on the center 1S of the heating coil 1. Was inconvenient. Therefore, in the triangle display according to the fourth embodiment, as shown in FIG. 7A, the pot bottom 2a of the large pot allows the display to clearly appear without being hidden to the top of the triangle, so that the conventional single circle is used. A more accurate determination can be made.
[0051]
As shown by the solid lines in FIGS. 7A and 7B, when the pot is placed concentrically with the center 1S, the center of the triangle is hidden by the pot bottom 2a, and the triangle not hidden by the pot bottom 2a is indicated by the triangle 2a. According to the size and shape of the pan, the cooker can accurately determine the size and shape of the pot bottom 2a by visually observing the balance of the protrusion amount and the area of the tops.
[0052]
7A and 7B, if the pan bottom 2a is eccentric with respect to the center 1S, the top of the triangular display that is not hidden by the pan bottom 2a according to the degree of eccentricity is the eccentricity. , The cooker can accurately determine the eccentricity of the pot bottom 2a by visually observing the degree of the shift. In this manner, the cook can visually check the spread portion (the top of the triangle in the third embodiment) of the position confirmation display means 37 which is provided on almost the entire area of the top plate 6 and can be seen without being hidden by the pot bottom 2a. Is determined, and the cooking can be performed by placing the pan at an appropriate position on the top plate 6, that is, at a concentric position between the heating coil 1 and the pan bottom 2a. Since overheating of the pan 2 caused by the detection error of the temperature detecting means 8 due to the deviation can be prevented, the safety of use and the stove is also improved.
[0053]
Note that the triangle display of the position confirmation display means 36 may be a design display by printing or the like, instead of the above-described lighting display. In this case, it is preferable to print the triangle display line thickly so that a circle of 110 mm (minimum size that hinders heating) just inscribes the inside of the line, since it becomes easy to understand the appropriate minimum determination of heating. Further, the display shape of the position confirmation display means 36 is not limited to a triangular shape, and various types described later can be selected.
[0054]
Hereinafter, other examples of the design display in the fifth embodiment will be sequentially described with reference to FIGS. The center of each display is set in accordance with the center of the above-described heating coil.
[0055]
(Example 5)
The position confirmation display means 37 shown in FIG. 8 is an example of a repeated display in which a large number of circular loop lines 37a are arranged concentrically with the center of the heating coil (hereinafter, abbreviated as the center). In this display, the maximum diameter is larger than that of the conventional single or double circle display, and a large number of loop lines 37a are displayed in two colors alternately (printing may be performed in one color, but the display is performed in two colors). In addition, the deviation with respect to the loop line 37a having a size corresponding to a small amount of displacement can be easily visually determined together with the direction, and the larger the deviation, the more the deviation extends over more loop lines 37a. Therefore, it becomes easier to intuitively recognize the deviation and the amount of the deviation.
[0056]
The position confirmation display means 38 shown in FIG. 9 is an X-shaped line 38a extending linearly continuously from the center in four directions, and the position confirmation display means 39 shown in FIG. This is a cross-shaped line 39a rotated by 45 °. In these cases, even with a slight eccentricity of the pan 2, the balance of the protruding amount at the end of the line is largely distorted in the corresponding direction. It can be carried out. Note that the X-shaped line 38a may be a discontinuous broken line.
[0057]
The position confirmation display means 40 shown in FIG. 11 is obtained by coloring a large number of circular loop lines 40a, 40b, 40c arranged concentrically with the center with three different colors. In these, in addition to the effect of the display made by the loop line 37a shown in FIG. 8, the larger the amount of deviation is, the more it is shifted over a plurality of objects of different colors, so that it is easier to determine. Even if the colors of the loop lines 40a, 40b, and 40c of all sizes are not changed for the determination, if the color is repeatedly changed in units of a shift amount width that makes it difficult to determine, a line of a different size of a color having a matching size can be obtained. The above-described determination using the color difference between the two can be performed more accurately.
[0058]
The position confirmation display means 41 shown in FIG. 12 is composed of a large number of circular arcs 41b in which one block formed by cutting out a large number of circular loop lines 37a shown in FIG. 8 with a white X-shaped line 41a forms a fan shape. it's shown. Therefore, both the advantages of the display shown in FIG. 8 and the advantages of the display shown in FIG. 9 are provided, which is more preferable. The position confirmation display means 42 shown in FIG. 13 uses a cross-shaped line 41a instead of a white X-shaped line 42a for cutting out a circular line and leaving a large number of arcs 42b. Has the advantage of
[0059]
The position confirmation display means 43 shown in FIG. 14 has a large number of square loop lines 43a arranged concentrically with the center. These many loop lines 43a repeatedly form four blocks from the center to form four triangular blocks whose vertices face the center. According to this display, if there is a displacement, the balance between the spread amount and the area in each of the four blocks is largely disturbed in the corresponding direction, so that it is easy to intuitively recognize the displacement and the displacement amount. Further, the square display is spread over the entire area of the top plate 6 and is not hidden by a large pan, a square pan for bread, or a plate, which is preferable.
[0060]
The position confirmation display means 44 shown in FIG. 15 is composed of a large number of straight lines 44b in which one block formed by cutting out a plurality of square lines shown in FIG. 14 with a white X-shaped line 44a forms a triangle. it's shown. Therefore, it is more preferable because it has both the advantages of the display shown in FIG. 14 and the advantages of the display shown in FIG. 9, and the notch may be a cross-shaped line. The position confirmation display means 45 shown in FIG. 16 displays a triangular block formed by a number of straight lines 45b and 45c cut out by a white X-shaped line 45a in two colors, upper, lower, left and right. Yes, the spread amount and area that are not hidden by the placement of the pan can be easily seen at a glance, so that the determination becomes easier.
[0061]
The position confirmation display means 46 shown in FIG. 17 is obtained by coloring a large number of circular loop lines 46a, 46b, 46c arranged concentrically with the center with three different colors. The lines are printed with a smaller width than the display shown in FIG. In this display as well, similar to the display shown in FIG. 11, it is possible to accurately make a determination using a difference in color between lines of different sizes and matching colors.
[0062]
The position confirmation display means 47 shown in FIG. 18 displays circular loop lines 47a, 47b, and 47c, which are color-coded in the same manner as shown in FIG. 17, and overlaps a cross-shaped line 47a with another color thereon. The advantage of both the circular loop line display and the cross-shaped line display can be utilized. The position confirmation display means 48 shown in FIG. 19 is also displayed by circular loop lines 48a, 48b, and 48c, and an X-shaped line 48d is superimposed on the loop lines 48a, 48b, and 48c. In addition, the X-shaped line 48d extends in four directions beyond the outermost loop line 48a, so that it is also suitable for determining whether a large pot is placed.
[0063]
As in the display shown in FIG. 14, the position confirmation display means 49 shown in FIG. 20 displays the corners of the square line arranged concentrically with the center with a rounded line 49a. Since the X-shaped line can be visually observed as if the X-shaped line is raised by forming a rounded square line, the same function and effect can be obtained without notching or overlapping the square line with the X-shaped line. Can be played.
[0064]
The position confirmation display means 50 shown in FIG. 21 is a display in which a line 50a having the same shape as that shown in FIG. And X-shape) are more preferable because they are more easily visible.
[0065]
The position confirmation display means 51 shown in FIG. 22 displays a large number of quadrangular (corner portions are round) lines 51a, 51b, and 51c arranged concentrically with the center in three different colors. I have. The display shown in FIG. 20 is repeated in four directions and color-coded to make it easy to understand, and the same advantages as the displays shown in FIGS. 11 and 17 in which the circular lines are color-coded can be utilized.
[0066]
The position confirmation display means 53 shown in FIG. 23 is a combination of a circular loop line 53a arranged concentrically with the center and points 53b arranged at four corners equidistant from the center. According to this combination display, the normal pot 2 is placed using the loop line 53a, and when the large pot 2 is placed on the top plate 6, the points 53b at the four corners are not hidden, By visually checking the balance of the distance between the point 53b and the pot 2, the cooker can accurately determine the size and shape of the pot 2. When the pot 2 is eccentric with respect to the center, not only the display of the loop line 53a but also the distance becomes longer or shorter corresponding to the eccentricity according to the degree of eccentricity, and the balance is lost. Can be visually checked to determine the placement state of the pan 2, and the pan 2 can be moved to an appropriate position (center position) on the top plate 6. Further, the loop line can be combined with not only a circular shape but also a square loop line 54 as shown by an imaginary line or the position confirmation display means shown in the above-described embodiments, and the respective advantages can be utilized. It is preferable to display the two types in different colors, because even if the two types of displays are overlapped, they can be easily understood and visually checked.
[0067]
FIG. 24 shows the position confirmation display means 52 in the induction heating cooker in which the top plate 6 has the maximum depth dimension for placing a large pot. Further, in the case of this embodiment, the heating coil (shown by oblique lines in the figure) 1 is also set so that the distance between the two centers becomes shorter unlike the conventional case.
[0068]
Conventionally, as shown in FIG. 25, the position of the heating coil 1 is determined so that two pots of the same size can be placed. Therefore, even if the position confirmation display unit 55 including a large number of circular loop lines 55a as shown in FIG. 8 is provided in accordance with the center 1S of the heating coil 1, the following problem occurs. In other words, when the large pot is placed over the entire mountable area of the top plate 6, the center 2S of the pot bottom 2a of the large pot and the center 1S of the heating coil are displaced and cannot be placed at an appropriate position.
[0069]
Therefore, as shown in FIG. 24, the distance between the centers of the heating coils 1 is set to be short, and the distance between the centers of the position confirmation display means 52 is set to be short in accordance with the distance. A circular loop line 52a is provided. That is, since the center of one position confirmation display means 52 is closer to the center of the other position confirmation display means 52, the two loop lines 52a for the stove are displayed so as to slightly overlap each other. With this, when a normal pot is placed, the maximum diameter is larger than that of the conventional single circle display, and a large number of circular loop lines 52a are repeatedly displayed and displayed around the periphery. Of course, even when the large pot is placed on the entire area where the top plate 6 can be placed, the center 1S of the heating coil 1 and the center 2S of the pot bottom 2a are in a state of being fitted, so that an efficient and appropriate A large pot can be placed in the position.
[0070]
【The invention's effect】
As described above, according to the present invention, the state of the mounted object is determined based on the presence or absence of detection at each position of each light detection unit, so that the state of the top plate is determined based on a difference in detection value at each position. In addition, the determination when the cooked body is removed during cooking can be accurately determined from a change that occurs at that time and in which all or part of the detection result from the placed state is inverted to the same detection state. Since the inverter circuit is not driven for each judgment, heating is performed immediately when an appropriate heating cook is placed without placing a burden on the oscillation element and emitting unnecessary electromagnetic waves. It can be restarted, and usability and stove safety can be improved.
[0071]
If the control means performs at least one measure of the external notification of the determination result and the control of the input current to the heating coil, the cook can easily notice the abnormality by the external notification such as a buzzer sound or light, The cook can be prompted to take measures, so the cook can easily notice the misplacement of the cooked body or the misalignment and the necessity of the measure.If the cooked body is to be re-placed or not re-placed, It is possible to take prompt measures such as reducing the heating output by current control or stopping the heating output by interrupting the current supply so that heating is not performed with the mounting displacement, and measures are delayed or not taken. Can be prevented.
[0072]
If the plurality of locations are a plurality of extension areas extending from the center of the heating coil to the periphery, and a plurality of locations in the center of the heating coil and each annular extension area concentric with the center, the heating coil is concentric with the center of the heating coil. The size and shape of the heating cooker placed on the heating cooker can be determined, and the eccentricity of the heating cooker whose heating cooker center is eccentric to the center of the heating coil can be determined. In addition to being able to judge the degree, it is also possible to judge undersized objects including specially shaped objects such as knives and forks, and if you have light detection means to detect light, you can judge dirt on the top plate, In the case of detecting reflected light as light, it is possible to determine whether the bottom of the cooked body is floating due to the warpage, based on the time from irradiation to detection.
[0073]
As described in the above invention, if the control is performed based on the determination result of the state determination unit and the determination result of the load determination unit, only the determination result is determined when the load determination unit determines that the load is small. In addition, by taking the measures of the control means together with the determination result of the state determination means, the appropriate determination is made by both the state determination means and the load determination means. It is possible to eliminate the inconvenience of stopping the heating in spite of the body, or, on the contrary, no matter how much the heating does not result in the heating, the heating is continued and the oscillation element is damaged.
[0074]
Further, since the present invention is provided with the position confirmation display means as described above, when the heating cook is placed concentrically with the center of the heating coil, the position confirmation display means which is not hidden by the heating cook is provided. The cooker can accurately determine the size and shape of the cooked body by visually observing the spread amount and the balance of the area, and when the cooked body is eccentric with respect to the center of the heating coil, the position is determined. The placement state of the cooked body is determined by visually checking the degree of deviation of the spread portion of the confirmation display means, and the cooked body is placed at an appropriate position on the top plate, that is, a concentric position between the heating coil and the bottom of the cooked body. It can be placed and cooked, making it easier to use and preventing overheating of the cooked body due to misdetection of the temperature of the cooked body due to misplacement. It is also improved.
[0075]
Further, as another position confirmation display means, if a point-shaped thing is provided at four corners equidistant from the center of the heating coil on the top plate, when a large cooked body is placed on the top plate, The cooker can accurately determine the size and shape of the cooked food by visually checking the balance of the distance between the position confirmation display means and the cooked food at the four corners. Further, when the heating cook is eccentric with respect to the center position, the distance is shortened corresponding to the eccentricity according to the degree of eccentricity, and the placement state of the heating cook is determined by visually checking the degree of narrowness. Then, the heating cooking can be performed after the heating cooking body is moved to a proper position on the top plate, that is, a concentric position between the heating coil and the bottom of the heating cooking body. Since it is possible to prevent overheating of the cooked body caused by the temperature detection failure at the bottom of the cooked body, the safety of use and the stove is also improved.
[0076]
In addition to the dot-like display of the above invention, an annular position confirmation display means concentric with the center of the heating coil, or continuously, discontinuously, and repeatedly over almost the entire area of the top plate at least three directions from the center of the heating coil. By providing at least one position confirmation display means extending in a common manner, and displaying any one of these position confirmation display means in combination with the point-like position confirmation display means, the advantages of both are utilized. In addition, it is preferable that both types of display be displayed in different colors, because even if two types of display are overlapped, it becomes easy to understand and easily see.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing the entire configuration of a first embodiment of the present invention.
FIG. 2 is a control block diagram of the first embodiment.
FIG. 3 is an enlarged longitudinal sectional view showing a main part of the first embodiment.
FIG. 4 is a schematic plan view of a main part of the first embodiment viewed from above.
5A and 5B schematically show a main part of a third embodiment of the present invention, in which FIG. 5A is a longitudinal sectional view showing a state in which there is no dirt on the top plate, and FIG. FIG.
FIG. 6 is a perspective view schematically showing the whole of a fourth embodiment of the present invention.
FIG. 7 is a schematic plan view of a main part of Example 4 as viewed from above.
FIG. 8 is a schematic plan view showing a position confirmation display unit according to the fifth embodiment.
FIG. 9 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 10 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 11 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 12 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 13 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 14 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 15 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 16 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 17 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 18 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 19 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 20 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 21 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 22 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 23 is a schematic plan view showing another embodiment of the position confirmation display means.
FIG. 24 is a schematic plan view showing an embodiment of a heating coil having a different arrangement from the related art and a position confirmation display unit adapted to the heating coil.
FIG. 25 is a schematic plan view showing the arrangement of a conventional heating coil and position confirmation display means.
[Explanation of symbols]
1 heating coil
1S center (center of heating coil)
2 hot pot (cooked body)
3 Light detection means
4 State judgment means
5 control circuit (control means)
6 Top plate
7 Load judgment means
36-54 Position confirmation display means

Claims (7)

In an induction heating cooker in which a high-frequency current is passed through a heating coil to generate heat in a cooking body, light is incident from a plurality of locations on a top plate on which the cooking body is placed, or irradiated from the lower surface of the top plate in the plurality of locations. A state in which the shape, state, or state on the top plate of the mounted object is determined by a combination of a light detection unit that detects light reflected from the bottom surface of the cooked body, and a plurality of detection results obtained by the light detection unit. An induction heating cooker comprising: a determination unit; and a control unit that performs control according to a determination result of the state determination unit. The induction heating cooker according to claim 1, wherein the control unit performs at least one measure of external notification of a determination result and control of an input current to a heating coil. The plurality of locations are a plurality of extension areas on the top plate from the center of the heating coil toward the periphery, and the plurality of locations are the center of the heating coil and each of the annular extension areas concentric with the center of the heating coil. 2. The induction heating cooker according to claim 1. An input current to the heating coil, an input voltage, a resonance current, and a load determination unit that determines a load based on at least one of the resonance voltages, wherein the control unit determines a determination result of the state determination unit and a determination result of the load determination unit. The induction heating cooker according to any one of claims 1 to 3, wherein the induction heating cooker is controlled based on the control. An induction heating cooker provided with position confirmation display means extending in at least one common mode of continuous, discontinuous, and repetitive at least three sides from the center of the heating coil over substantially the entire area of the top plate. An induction heating cooker in which point-like position confirmation display means are provided at four corners equidistant from the center of a heating coil on a top plate. At least one common mode of continuous / discontinuous / repeating is provided in almost all areas on the top plate in the form of annular position confirmation display means arranged concentrically with the center of the heating coil or at least three sides from the center of the heating coil. 7. The induction heating cooker according to claim 6, further comprising a position confirmation display unit which is extended by being held.

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