JP4624520B2

JP4624520B2 - Driving circuit, electromechanical acoustic transducer, and portable terminal device

Info

Publication number: JP4624520B2
Application number: JP2000114367A
Authority: JP
Inventors: 周二佐伯; 佐和子薄木
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 1999-04-14
Filing date: 2000-04-14
Publication date: 2011-02-02
Anticipated expiration: 2020-04-14
Also published as: JP2001212508A

Description

【０００１】
【発明の属する技術分野】
本発明は携帯電話、ポケットベル、ＰＨＳ（ＰｅｒｓｏｎａｌＨａｎｄｙＰｈｏｎｅＳｅｔ）などの携帯端末の呼び出し音又は呼び出し用振動の発生に使用される電気−機械−音響変換装置およびその駆動方法に関するものである。
【０００２】
【従来の技術】
従来、携帯電話、ポケットベル、ＰＨＳ（ＰｅｒｓｏｎａｌＨａｎｄｙＰｈｏｎｅＳｅｔ）等の携帯端末装置では、その本体内に複数個の電気−機械−音響変換器が取り付けられ、電気信号発生装置を接続してベル音や振動を選択的に発生させ着信を知らせる手段として用いられてきた。
【０００３】
携帯端末装置の小型化、軽量化を図るために、発音と振動を１つのユニットで実現する電気−機械−音響変換装置を用いた携帯電話が考案され、モトローラ対応日本出願特開平８−２７５２９３号公報に開示されている。
【０００４】
従来の技術における図３２の電気−機械−音響変換装置３２００は次のように構成される。可動質量部１が平面非線形バネ部材２で支持されている。コイル型３の内部には電磁コイル４が収納され、電磁コイル４の対向部に永久磁石５が可動質量部１の外周部に固着されて配置される。ここでは図示しないが、コイル型３の外周部がサウンドボード（例えば携帯電話のケース）に取り付けられた構成となっている。
【０００５】
【発明が解決しようとする課題】
前記電気−機械−音響変換装置３２００では、電磁コイル４に駆動信号が加えられると交番磁界が発生し、永久磁石５との間で交番励磁力が生じ可動質量部１が振動して、この振動がサウンドボードに伝達され、携帯電話の着信時の振動呼び出しを可能とするものである。また、発音に関しても同様の原理で動作するものである。ここで、大きな振動力を得るために、可動質量部１の支持部材２として平面非線形バネ部材が用いられる。図３３に、平面非線形バネ部材の変位周波数特性を示す。非線形バネ部材では跳躍現象と呼ばれる振動特性を示すことが知られている（例えば、吉久著「スピーカ」理工研究社（昭和４８年０３月））。これは周波数を上げていくと非線形バネ部材の変位特性がＡ→Ｂ→Ｃ→Ｄのように変化し、周波数を下げていくとＤ→Ｃ→Ｅ→Ｆ→Ａと変化する現象である。
【０００６】
そこで、従来の電気−機械−音響変換装置３２００は、Ｆ〜Ｂの周波数範囲では加える周波数信号の方向により特性が変化し安定な振動を得られないため、周波数信号の方向で特性が変化しないＡ〜Ｆの周波数範囲を掃引する駆動信号が用いられていた。しかし、Ａ〜Ｆの周波数範囲では、周波数Ｆでは振動力が大きくなるが周波数Ａでは振動力が極端に低下して、周波数掃引中における振動出力は必ずしも効率的なものではなかった。特に、携帯電話等の移動体情報端末装置では、駆動電源がバッテリーであるため変換器の効率を可能な限り向上させて省電力化を図ることが、長時間の使用のために強く求められるものである。
【０００７】
本発明は上記課題を解決して、安定的で高効率な振動出力が得られる電気−機械−音響変換装置を提供するものである。
【０００８】
【課題を解決するための手段】

【００１９】
本発明に係る他の駆動回路は、所定の振動力周波数特性を有する機械振動系を有する振動器を駆動する駆動回路であって、前記機械振動系は、所定の周波数範囲で周波数の上昇と下降とで異なる振動力周波数特性を有し、前記周波数範囲は、該周波数範囲で最も低い周波数を表す低域限界周波数と該周波数範囲で最も高い周波数を表す高域限界周波数とを含み、前記駆動回路は、前記周波数範囲に含まれる周波数を有する第１信号と、前記低域限界周波数より低い周波数を有する第２信号とを前記振動器に出力し、前記第２信号は、前記第１信号と同時に前記振動器に出力され、前記振動器は、電気信号を音と振動との少なくとも一方に変換する機能を有し、前記振動器は、磁気回路部と少なくとも１つのサスペンションとを含み、前記サスペンションは、非線形サスペンションであり、そのことにより上記目的が達成される。

【００２２】
前記サスペンションは、スチフネスＳを変位Ｘの多次関数であらわした場合、Ｘ²項が値を有してもよい。
【００２３】
駆動回路は、振動の周波数信号、あるいは音の電気音響信号を発生する電気信号発生装置であってもよい。
【００２４】
前記第１信号は、周波数が連続的に変化する掃引信号を含でもよい。

【００２５】
前記第１信号は、複数個のポイント周波数信号を含んでもよい。

【００２６】
前記第１信号と前記第２信号との少なくとも一方は、周波数が低いほうから高い方へ変化する上昇信号を含んでもよい。
【００２７】
前記第１信号は、周波数が連続的に変化する掃引信号を含み、前記第１信号は、上昇から下降への第１折り返し周波数と下降から上昇への第２折り返し周波数とを有し、前記第１折り返し周波数は、前記高域限界周波数よりも低く、前記第２折り返し周波数は、前記低域限界周波数よりも高くてもよい。
【００２８】
前記第１信号は、少なくとも１つのポイント周波数信号を含んでもよい。
【００２９】
前記駆動回路は、前記第１信号と前記第２信号とを加算した合成信号を前記振動器に出力してもよい。
【００３０】
前記駆動回路は、前記第１信号と前記第２信号とを位相を変えて加算した合成信号を前記振動器に出力してもよい。
【００３１】
前記第１信号と前記第２信号との少なくとも一方は、正弦波信号を含んでもよい。
【００３２】
前記第１信号と前記第２信号との少なくとも一方は、矩形波信号を含んでもよい。
【００３３】
前記駆動回路は、前記合成信号の出力電圧のピークを制限するリミッターを含んでもよい。
【００３４】
前記合成信号は、正弦波信号であり、前記合成信号は、隣合う２つの周波数信号を１組の信号として、第１組は逆相として合成し、第２組は正相で合成し、上記第１組、第２組の信号をさらに１組の組み合わせとして複数個、これを合成して構成される周波数信号であってもよい。
【００３８】
本発明に係る他の電気機械音響変換装置は、所定の振動力周波数特性を有する機械振動系を有する振動器と、前記振動器を駆動する駆動回路とを備え、前記機械振動系は、所定の周波数範囲で周波数の上昇と下降とで異なる振動力周波数特性を有し、前記周波数範囲は、該周波数範囲で最も低い周波数を表す低域限界周波数と該周波数範囲で最も高い周波数を表す高域限界周波数とを含み、前記駆動回路は、前記周波数範囲に含まれる周波数を有する第１信号と、前記低域限界周波数より低い周波数を有する第２信号とを前記振動器に出力し、前記第２信号は、前記第１信号と同時に前記振動器に出力され、前記振動器は、磁気回路部と少なくとも１つのサスペンションとを含み、前記サスペンションは、非線形サスペンションであり、そのことにより上記目的が達成される。
前記サスペンションは、スチフネスＳを変位Ｘの多次関数であらわした場合、Ｘ ² 項が値を有する非線形サスペンションであってもよい。

【００３９】
前記駆動回路は、前記第１信号と前記第２信号とを加算した合成信号を前記振動器に出力し、前記駆動回路は、前記第１信号と前記第２信号との周波数と周波数間隔と位相と電圧レベルとの少なくとも１つを変化させることにより、該合成信号を選択的に変化させてもよい。
【００４７】
本発明に係る他の携帯端末装置は、所定の振動力周波数特性を有する機械振動系を有する振動器と、着信信号と受話信号とを受信するアンテナと、前記着信信号を信号処理して電気信号を前記振動器に出力する受信信号処理手段と、前記振動器を駆動する駆動回路とを備え、前記機械振動系は、所定の周波数範囲で周波数の上昇と下降とで異なる振動力周波数特性を有し、前記周波数範囲は、該周波数範囲で最も低い周波数を表す低域限界周波数と該周波数範囲で最も高い周波数を表す高域限界周波数とを含み、前記駆動回路は、前記周波数範囲に含まれる周波数を有する第１信号と、前記低域限界周波数より低い周波数を有する第２信号とを前記振動器に出力し、前記第２信号は、前記第１信号と同時に前記振動器に出力され、前記振動器は、磁気回路部と少なくとも１つのサスペンションとを含み、前記サスペンションは、非線形サスペンションであり、そのことにより上記目的が達成される。
前記サスペンションは、スチフネスＳを変位Ｘの多次関数であらわした場合、Ｘ ² 項が値を有する非線形サスペンションであってもよい。

【００４８】
前記受信信号処理手段の出力に基づいて、前記振動器を前記駆動回路と前記受信信号処理手段とのいずれかと接続する切替手段をさらに備えてもよい。
【００４９】
前記受信信号処理手段により出力される前記電気信号と前記駆動回路の出力とを合成する信号合成手段をさらに備えてもよい。
【００５０】
前記受信信号処理手段と前記信号合成手段との間に設けられる第１スイッチと、前記駆動回路と前記信号合成手段との間に設けられる第２スイッチと、前記信号合成手段と前記振動器との間に設けられる第３スイッチとをさらに備えてもよい。
【００５１】
前記駆動回路は、前記第１信号と前記第２信号とを加算した合成信号を前記振動器に出力し、前記駆動回路は、前記第１信号と前記第２信号との周波数と周波数間隔と位相と電圧レベルとの少なくとも１つを変化させることにより、該合成信号を選択的に変化させてもよい。
本発明に係る駆動回路は、所定の振動力周波数特性を有する機械振動系を有する振動器を駆動する駆動回路であって、前記機械振動系は、所定の周波数範囲で周波数の上昇と下降とで異なる振動力周波数特性を有し、前記周波数範囲は、該周波数範囲で最も低い周波数を表す低域限界周波数と該周波数範囲で最も高い周波数を表す高域限界周波数とを含み、前記駆動回路は、前記周波数範囲に含まれる周波数を有する第１信号と、前記低域限界周波数より低い周波数を有する第２信号とを前記振動器に出力し、前記第２信号は、前記第１信号と同時か、若しくは、それ以前に前記振動器に出力され、前記振動器は、電気信号を音と振動との少なくとも一方に変換する機能を有し、前記振動器は、磁気回路部と少なくとも１つのサスペンションとを含み、前記サスペンションは、スチフネスＳを変位Ｘの多次関数であらわした場合、Ｘ ² 項が値を有する非線形サスペンションであり、そのことにより上記目的が達成される。

【００５６】
【発明の実施の形態】
以下、本発明の実施の形態について図面を参照して説明する。
【００５７】
（実施の形態１）
図１は本発明の実施の形態１の電気−機械−音響変換装置１００のブロック回路図である。同図によると、６は振動器、７は電気信号発生装置、ＳＷ１は信号切替スイッチである。
【００５８】
図２、図３Ａ、図３Ｂは本発明の電気−機械−音響変換装置１００に用いられる振動器６の構成例を示す。図２は分解斜視図であり、図３Ａはバッフルを除いた状態の上面図、図３Ｂは側断面図である。
【００５９】
図２、図３Ａ、図３Ｂによると、８は重り部を一体に形成したヨークとマグネットとプレートからなる磁気回路部であり、９、１０はこの磁気回路部８の上・下にそれぞれ結合された上・下サスペンションであり、この上・下サスペンション９，１０のそれぞれの対向辺には上・下サスペンション９，１０間では互いに異なる位置に上・下サスペンション９，１０から延出されたそれぞれ一対となる足部９ａ，９ｂ，１０ａ，１０ｂが設けられている。ここで、磁気回路部８の重量は３ｇである。
【００６０】
１１は上側開口部１１ｅと下側開口部１１ｆを有すると共に上記足部９ａ，９ｂ，１０ａ，１０ｂがそれぞれ結合される受納部１１ａ，１１ｂ，１１ｃ，１１ｄを設けたプラスチック性の支持部材であり、１２は外周縁を上記支持部材１１の下側開口部１１ｆに結合された非磁性体であるチタン材やプラスチックからなる振動板である。ボイスコイル１３は振動板１２の中央に接着され、端部が上記上・下サスペンション９，１０に支持された上記磁気回路部８の磁気ギャップ８ａに挿入される。
【００６１】
１４は上記支持部材１１の上側開口部１１ｅに装着されたバッフルであり、１１ｇはボイスコイル１３のリード線に接続される外部入力端子である。
【００６２】
上・下サスペンション９、１０の材質は例えばステンレス、ベリリューム合金等のバネ材料で、その寸法、形状により振幅変位量に対するスティフネス特性が非線形となるように設計される。ここで例えば、足部９ａ，９ｂ，１０ａ，１０ｂは長さ８ｍｍ、幅１ｍｍ、厚さ０．０８５ｍｍである。
【００６３】
図４は上・下サスペンション９、１０の変位−力特性を示す。この特性は上・下サスペンション９、１０の足部９ａ，９ｂ，１０ａ，１０ｂを固定し、中央部が結合された磁気回路部８に力を加えた場合の特性であり、横軸が変位、縦軸が力をあらわす。図５は図４の結果より、サスペンション９、１０のスティフネス特性を求めたものであり、横軸が変位、縦軸がスティフネスをあらわす。サスペンション９、１０は変位の増加とともにスティフネス値が増大する非線形性を示すものである。以上のような非線形サスペンション９、１０で構成された振動器６に周波数信号を入力した場合に、振動器６に発生する振動力特性を図６に示す（ここで、磁気回路部８の質量は約３ｇである）。図６では周波数を低周波数から高周波数に上昇させた場合と高周波数から低周波数に下降させた場合の力特性を示す。まず、周波数を連続的に上昇させると力はａ→ｂ→ｃ→ｄと変化する。
一方、周波数を連続的に下降させるとｄ→ｃ→ｅ→ｆ→ａと変化する。この結果は、図３３で説明した従来の非線形サスペンションとほぼ同じ現象であり、非線形サスペンションの跳躍現象として知られている。
【００６４】
以上のような非線形サスペンションで構成された振動器６を用いる電気−機械−音響変換装置の動作を説明する。
【００６５】
電気信号発生装置７で発生した周波数信号は、信号切替スィッチＳＷ１がＯＮとなると振動器６に入力される。前記周波数信号は図６で示した非線形サスペンション９、１０の力特性で周波数の上昇と下降で異なる特性を示すポイントｆを低域限界周波数ｆＬ、ポイントｂを高域限界周波数ｆＨとして、ｆＬとｆＨの周波数範囲をＷｂとするとき、少なくとも周波数信号の１つがｆＬよりも高くｆＨよりも低い周波数を含むものである。周波数範囲Ｗｂでは振動器６が発生する力は最大となるが、例えば図６の周波数範囲Ｗｂで大きな力が得られる１４０Ｈｚの信号のみを加えた場合、力の値は周波数を下降して得られる特性上の１４０Ｈｚとなるポイントｇの値となり、目的とする周波数の上昇で得られる１４０Ｈｚの力値であるポイントｈとはならないものであった。また、Ｗｂ内でｂ→ｆというように周波数を下降させても同様に、力値が上昇スィープの特性ｆ→ｂを再現するものではない。大きな力が得られるｆからｂの特性を安定的に確保するために、周波数範囲Ｗｂの低域限界周波数であるｆＬよりも低い周波数を、少なくとも１つは、振動器６への入力信号として加えるものである。
【００６６】
また、図７に示すように掃引信号は、まず初期信号として、ｆＬよりも低い周波数であるポイントｉからＷｂの周波数内に位置するｈに向かって上昇し、Ｗｂの周波数内に位置するｊで再びｈに向かって折り返し、ｈとｊの間で掃引を繰り返す信号（初期はｉ→ｈ、その後はｈ→ｊ→ｈ→ｊ→ｈと繰り返す）とするならば、掃引が振動力の大きな周波数範囲Ｗｂ内で行なわれるため、より強い振動力を確保できるものである。
【００６７】
なお、前記の周波数信号ではｉからｈへの周波数上昇の掃引後に下降、上昇の周波数掃引を繰り返しているが、ｉからの周波数上昇掃引を周波数ポイントｈで止めて、周波数ポイントｈで周波数を固定し連続的に印加しても、その周波数を単独で入力した場合のように、振動力が周波数の下降時の振動力（ポイントｇ）まで低下することはなく、大きな振動力を維持するものである。従って、周波数上昇掃引を止める周波数をＷｂの高域限界周波数ｆＨにより近く設定すれば、連続的により大きな振動力が得られるものである。
【００６８】
また、振動器６を構成するサスペンションのスティフネス特性は特に重要である。図８は非線形性を持たないサスペンションで支持された磁気回路部を有する振動器６の振動力特性を示す。線形サスペンションでは周波数の上昇、下降で特性が変化することはないが、振動力が大きくなる周波数がサスペンションのスティフネスと磁気回路部の質量で構成される機械系の共振周波数ｆ０のみとなり、共振周波数ｆ０を外すと振動力は極端に低下するものであった。このため、駆動信号の周波数を機械系の共振周波数ｆ０に一致させる共振周波数検出の手段を必要としていた。あるいは、振動器６の共振周波数を定められた駆動周波数に一致させるように、製造過程での厳密な共振周波数の管理を必要とするものであった。図６で示した非線形サスペンションの振動力特性では、線形サスペンションのｆ０ような狭い帯域ではなく、ｆ→ｂという広い周波数帯域で大きな力を有するものである。このような広い周波数帯域で大きな力を得るためには、サスペンションの特別な非線形特性が必要となる。例えば、図６の特性とするためには、図４で示した変位（ｘ）−力（Ｆ）特性を
【００６９】
【数１】

【００７０】
と多次関数であらわして、さらに、図５で示した変位（ｘ）−スティフネス（Ｓ）特性を
【００７１】
【数２】

【００７２】
とあらわすことができる。例えば、（数２）においてＳ₁、Ｓ₂、Ｓ₃の値として
Ｓ₁＝５０３．６
Ｓ₂＝０
Ｓ₃＝５．５×１０⁸
と設定し、変位ｘ＝１ｍｍとするならば（数２）における値は（表１）のようになる。
【００７３】
【表１】

【００７４】
即ち、非線形項であるｘの２乗項（Ｓ₃ｘ²）が周波数の上昇、下降で異なる特性を生じさせる要因であり、また広い周波数帯域での大きな力の発生を可能にしているものである。
【００７５】
従って、本発明の電気−機械−音響変換装置１００に用いる振動器６ではそのサスペンション９、１０の少なくとも１つが、ｘの２乗項に値を有するものである必要がある。そこで、
Ｓ₁＝０
Ｓ₂＝０
Ｓ₃＝８．０×１０⁸
として、（数２）で示されるスティフネスのＳ₁、Ｓ₂の項がＳ₃の項に比べて小さく、実質的にＳ３の項のみであるとした場合、その変位−スティフネス特性は図９のようになり、また振動器６で発生する振動力特性は図１０で示すものとなって、周波数の上昇と下降で異なる振動力特性となる周波数範囲ｆ′〜ｂ′は図６、図７に示す周波数範囲ｆ〜ｂよりも広く、周波数上昇時の振動力特性の傾きは図６、図７に示す傾きよりも緩くなる。従って、入力信号の周波数変化に対する力の大きさの変化が少なくなり、より安定で大きな力が得られるものである。
【００７６】
なお、前記２例では、Ｓ₂の項が０と仮定したが、この項が０でなくても、周波数の上昇と下降で異なる特性となる跳躍現象はほぼ同様に生じるものである。
さらには、より高次の項がある場合でも同様である。
【００７７】
また、ｘの２乗項に値を有する非線形サスペンションは、変位の増加とともに振幅が制限されるスティフネス特性により実現されるが、この非線形性は例えばサスペンションの長さを短くして、サスペンションの振幅を制限する、あるいは、伸びが少ない材料を用いる等により比較的容易に実現できるものである。
【００７８】
さらに、本発明の電気−機械−音響変換装置１００では、振動器６に加える電気信号発生装置７で発生させる周波数信号は、周波数が連続的に変化する掃引周波数でなく、複数のポイント周波数でもよい。そのポイント周波数は、初期入力の周波数として領域Ｗｂの低域限界周波数ｆＬよりも低い信号を少なくとも１つ含むことが望ましい。図１１はポイント周波数の例を示す。最初はＰ１、次にＰ２→Ｐ３→Ｐ４→Ｐ５とポイント周波数を変化させて振動器６に印加する。最後のＰ５の周波数で固定して、この周波数Ｐ５で連続的に信号を加えるならば、振動器６から大きな振動力を連続的に出力させることが可能となる。あるいはＰ１→Ｐ２→Ｐ３→Ｐ４→Ｐ５と上昇させて、Ｐ５→Ｐ４→Ｐ３→Ｐ４→Ｐ５と領域Ｗｂ内で周期的に上昇、下降を繰り返してもよい。なお、ポイント周波数がＷｂ内にあるとき、Ｐ１からＰ５のように周波数幅が広すぎると安定な動作が得られないので、Ｐ１→Ｐ３→Ｐ５のようにＷｂの帯域内で初期周波数と最高周波数との間を複数個のポイント周波数で補完して駆動することが望ましい。ただし、Ｐ２→Ｐ３のように初期周波数Ｐ２が周波数ｆＬよりも低く、Ｐ３が領域Ｗｂの内にある場合でも、そのポイント周波数がｆＬに比較的近い場合は、その間を補間するポイント周波数の信号は必要としないものである。
【００７９】
以上のように、前記実施の形態の電気−機械−音響変換装置１００は、非線形サスペンションを用いた振動器６により、広い周波数帯域にわたって、大きな振動力が効率よく得られるものである。
【００８０】
なお、信号の波形は正弦波が望ましいが、基本周波数が前記周波数の条件を満たす矩形波信号であっても同様な効果が期待できるものである。この場合は、高調波成分がボイスコイル１３に加えられ、振動時に不要な音を再生する可能性が高いため、電気信号発生装置７と振動器６との間に、高域をカットする高域カットフィルター１５１を挿入することが望ましい。
【００８１】
また、ボイスコイル１３に加える電気信号発生装置７からの入力信号が、高域成分を含む音声や音楽信号であるならば、振動板１２は振動してスピーカとして動作して、音響再生を可能とするものである。この場合、音響信号の低域限界を領域Ｗｂの下限周波数ｆＬよりも高くするならば、磁気回路部８はほとんど振動することなく、振動板１２のみが振動して音を発生するので、振動と音の再生を個別に機能させたいときは有効である。電気信号発生装置７で発生させる周波数信号は、前記周波数範囲Ｗｂ内に含まれる周波数と、周波数範囲Ｗｂよりも低い周波数を少なくとも１つ含む複数個の信号を加算した合成信号である。
【００８２】
以上のような周波数信号を発生する電気信号発生装置７と、非線形サスペンションを有する振動器６で構成された電気−機械−音響変換装置１００の動作を説明する。
【００８３】
電気信号発生装置７からの周波数信号は、振動器６に入力される。前記周波数信号は、例えば図１２で示した非線形サスペンション９、１０の力特性で周波数の上昇と下降で異なる特性を示す周波数範囲Ｗｂ内の周波数ポイントｔとＷｂよりも低い周波数ポイントｓとを加算した合成信号である。
【００８４】
まず、ポイントｓの周波数をｆ１、ポイントｔの周波数をｆ２としてそれぞれの周波数を単独で振動器６に入力した場合の振動力特性を図１３Ａ〜図１３Ｄに示す。図１３Ａはｆ２で電圧のピーク値がｆ１の約２倍の入力波形、図１３Ｂはｆ２入力時の振動力波形、図１３Ｃはｆ１の入力波形、図１３Ｄはｆ１入力時の振動力波形である。ポイントｔのｆ２は周波数範囲Ｗｂ内の周波数信号であり、図１２で示したように周波数の上昇掃引により振動器６の振動出力は大きな値となるが、この周波数信号を単独で加えた場合、振動力は周波数を下降掃引して得られる特性上のポイントｕの値まで低下するものである。ポイントｓの周波数ｆ１は周波数範囲Ｗｂよりも低い周波数であり、周波数の上昇、下降掃引で振動力が変化しないため、電圧のピーク値がｆ２の半分でも、ｆ１の信号を入力した場合よりも大きな出力波形（振動力波形）となっている。
【００８５】
次に、上記２周波数の合成信号を振動器６に入力した場合の振動力特性を図１４Ａ、図１４Ｂに示す。図１４Ａは入力信号波形、図１４Ｂは振動力波形である。入力波形は振幅変調され周期的な増減を繰り返すものである。出力波形となる振動力波形も時間と共にその値が増減しているが、波形の最大値は図１３Ａ〜１３Ｄで示した周波数の単独入力では得られなかった大きな値であり、周波数の上昇掃引で得られるｆ２のポイントｔでの振動力が２周波数の合成信号により得られることがわかる。
【００８６】
また、電気信号発生装置７で発生させる信号がメロディー音、音楽信号、会話音等の音響信号であれば、振動器６のボイスコイル１３が接合された振動板１２が振動して音響再生の動作をするものである。この場合、音響信号の低域周波数成分が周波数範囲Ｗｂを含むものであっても、振動力は小さいので、実質的に振動と音の機能は分離されたものとなる。一方、振動の信号と音響の信号を同時に入力するならば、振動と音の同時再生が可能であり、このように信号の周波数帯域、複数信号の合成により振動器６を振動及び音響再生用の多機能変換器として動作させることが可能となる。
【００８７】
なお、周波数範囲Ｗｂよりも低い周波数信号で得られる振動力よりも、周波数範囲Ｗｂ内の周波数信号の方が大きな振動力を出力するため、低い周波数信号の入力電圧レベルは、周波数範囲Ｗｂ内の周波数信号による振動力が安定に得られる必要最低限の電圧レベルとすることが、省電力のためには望ましい。また、本実施の形態では周波数信号は２つの正弦波としたが、２つ以上の複数としても同様の効果が得られるものであり、それぞれの電圧レベルは本実施例と同様な考え方により設定されるものである。さらに、信号波形は基本周期が前記周波数の条件を満たす異なる２つの矩形波の合成信号であってもよいが、信号に含まれる高調波成分により振動板１２から歪音が再生されるため、高音域をカットするハイカットフィルターを振動器６の前段に挿入することが望ましい。
【００８８】
また、図１５に非線形サスペンションを有する振動器６の量産時における製造バラツキにより生じる振動力周波数特性の変動をＬ，Ｍ，Ｈに示す。この場合、周波数を連続的に上昇させて測定した結果のみを示すが、周波数を連続的に下降させるならば、図６、図１２で示したようにそれぞれの特性は周波数の上昇とは異なる振動力特性、すなわち跳躍現象を示すものである。
【００８９】
ここで、電気信号発生装置７で発生させる周波数信号は、例えば振動器６の振動力特性変動が周波数の低い方へ移動したＬの特性における周波数範囲Ｗｂよりも低い周波数を少なくとも１つ含み、また変動が高いほうへ移動したＨの特性における周波数範囲Ｗｂよりも高い周波数を少なくとも１つ含むもので、これらの複数個の周波数信号Ｐ１〜Ｐ８の位相を変えて加算した合成信号である。
【００９０】
以上のような周波数信号を発生する電気信号発生装置７と、非線形サスペンションを有する振動器６で構成された電気−機械−音響変換装置１００の動作を説明する。
【００９１】
電気信号発生装置７からの周波数信号は、振動器６に入力される。前記周波数信号は、本例では振動器６の振動力特性変動が周波数の低い方へ移動したＬの特性における周波数範囲Ｗｂよりも低い周波数を最低周波数として、変動が高いほうへ移動したＨの特性における周波数範囲Ｗｂよりも高い周波数を最高周波数として、その間を等間隔に分割して、Ｐ１〜Ｐ８の８ポイントの周波数が設定される。
【００９２】
まず、本実施の形態の効果をよりわかり易くするため、８ポイントの周波数を同相で加算した信号を図７で示したＭの振動周波数特性を有する振動器６に入力された場合の電気信号と振動出力特性の時間波形を図１６Ａ、１６Ｂに示す。図１６Ａは電気信号の時間波形、図１６Ｂは振動出力の時間波形である。電気信号は各周波数の等周波数間隔の波長を周期（すなわち、５Ｈｚ間隔であれば２００ｍＳ）として強弱を繰り返し、振動出力波形も電気入力に従って、周期の初めには大きな振動力を出力するが、次の始り周期までは振動力が減衰するという振動波形となる。この振動波形によっても周期的に大きな振動力は得られるものであるが、より望ましくは大きな振動力が時間軸上で継続することである。
【００９３】
次に、最低周波数Ｐ１と隣の周波数Ｐ２の信号を逆相、Ｐ３とＰ４を同相、Ｐ５とＰ６を逆相、Ｐ７とＰ８を同相として加算合成した電気信号と振動出力特性の時間波形を図１７Ａ、１７Ｂに示す。図１７Ａは電気信号の時間波形、図１７Ｂは振動出力の時間波形である。図１６Ａ、１６Ｂの電気信号波形と比較して、電圧レベルの強弱周期が短縮される。これに伴い振動出力波形は大きな振動出力の後にその振動力が減衰するというものではなく、大きな振動が得られる時間が継続するものである。
【００９４】
また、合成信号を図１５で示した振動特性の低周波数側及び高周波数側に変動した特性Ｌ，Ｈに印加した場合の振動出力時間波形を図１８Ａ、１８Ｂに示す。図１８Ａは特性Ｌに、図１８Ｂは特性Ｈに印加した場合の振動出力波形である。
図１７Ｂで示した特性Ｍと同様に、連続した振動出力波形となり、振動器６の振動力特性が変動した場合でも、安定な振動出力が得られるものである。
【００９５】
また、電気信号発生装置７で発生させる信号がメロディー音、音楽信号、会話音等の音響信号であれば、振動器６のボイスコイル１３が接合された振動板１２が振動して音響再生の動作をするものである。この場合、音響信号の低域周波数成分が周波数範囲Ｗｂを含むものであっても、振動力は小さいので、実質的に振動と音の機能は分離されたものとなる。一方、振動の信号と音響の信号を同時に入力するならば、振動と音の同時再生が可能であり、このように信号の周波数帯域、複数信号の合成により振動器６を振動及び音響再生用の多機能変換器として動作させることが可能となる。
【００９６】
さらに、信号波形は基本周期が前記周波数の条件を満たす複数個の矩形波の合成信号であってもよいが、信号に含まれる高調波成分により振動板１２から歪音が再生されるため、高音域をカットするハイカットフィルター１５１を振動器６の前段に挿入することが望ましい。
【００９７】
以上のように、本実施の形態の電気−機械−音響変換装置は、非線形サスペンションを用いた振動器６と、隣合う２つの周波数信号を１組の信号として、第１組は逆相として合成、第２組は正相で合成、上記第１、第２組の信号をさらに１組の組み合わせとして複数個、これを合成加算して構成される周波数信号により、複数個のポイント周波数の周波数間隔が広い場合でもいずれかの周波数が、跳躍現象による振動力の大きな周波数範囲Ｗｂに含まれ、また、電気信号波形の電圧強弱周期の短縮により継続的に大きな振動力が得られる。さらに、振動器６の振動周波数特性が変動した場合でも、大きな振動力が得られる周波数帯域を含むようにポイント周波数の周波数範囲を設定するならば、常に安定した振動出力が得られるものである。さらに、印加する信号の周波数帯域により、振動と音響再生が任意に選択できるものである。
【００９８】
（実施の形態２）
前述した実施の形態１では、振動器６のサスペンションは跳躍現象が生じる非線形であるとしたが、跳躍現象が生じない線形なものでも、非線形サスペンションの場合と同様な共振周波数の上下周波数を含む帯域の中に含まれる信号から合成される合成信号を入力すれば、連続的な振動出力が得られるものである。さらに、線形のサスペンションであっても共振周波数特性が変動するが、変動する周波数帯域を含む複数個の周波数信号によって、非線形の場合と同様に、常に安定した振動出力が得られるものである。
【００９９】
図１９に線形サスペンション１３０の平面図を示す。中央部１３２には磁気回路部８が固着され、足部１３３ａ、１３３ｂは支持部剤１１に固着される。サスペンション１３０の力−変位特性は、サスペンションの腕１３１の長さＬを長くすることにより線形なものとなる。
【０１００】
図２０には線形サスペンション１３０を用いた振動器６の力周波数特性を示す。同図には、共振周波数がｆ０１、ｆ０２、ｆ０３と変化した場合の特性Ｉ、ＩＩ、ＩＩＩを示す。ここでは図示しないが、サスペンション１３０が線形であるため周波数の掃引方向で特性が異なるという跳躍現象が生じることはない。
【０１０１】
図２０の共振周波数の変化は、振動器６の特性のバラツキを示すものである。
また、下矢印Ｐ１〜Ｐ８は印加するポイント周波数信号を示す。これらのポイント周波数は特性Ｉ、ＩＩ、ＩＩＩの共振周波数ｆ０１、ｆ０２、ｆ０３を含む周波数範囲で設定されるものである。
【０１０２】
図２１Ａ、２１Ｂ及び２２Ａ、２２Ｂは線形サスペンション１３０に位相を制御した８ポイントの信号を印加した場合の振動力特性の時間波形である。本例では、磁気回路部の重量が１．４ｇ、線形サスペンションと磁気回路部で構成される機械共振系の共振周波数ｆ０１＝１２５Ｈｚ、ｆ０２＝１３５Ｈｚ、ｆ０３＝１４５Ｈｚ、またポイント周波数Ｐ１〜Ｐ８は１２０Ｈｚ〜１５５Ｈｚまで５Ｈｚ間隔で設定したものであり、Ｐ２とＰ６を逆相にしている。
【０１０３】
図２３は電気信号発生装置７の一例を示す。同図において、１０１から１０８は周波数信号発生器、１１０〜１１７は位相制御器、１２０は信号加算器を示す。
【０１０４】
振動器６に印加するＰ１〜Ｐ８までの加算信号は、まず、周波数発生器１０１〜１０８でｆ１＝１２０Ｈｚ、ｆ２＝１２５Ｈｚ、ｆ３＝１３０Ｈｚ、ｆ４＝１３５Ｈｚ、ｆ５＝１４０Ｈｚ、ｆ６＝１４５Ｈｚ、ｆ７＝１５０Ｈｚ、ｆ８＝１５５Ｈｚを発生させる。これらの信号は位相制御器１１０〜１１７に入力されるが、ｆ２とｆ６は位相を１８０度遅らせて逆相とし、他の信号は同相として、全ての信号は信号加算器１２０で合成されその出力が、振動器６に加えられるものである。
【０１０５】
図２１Ａは、加算されたＰ１〜Ｐ８の時間波形を示す。図２１Ｂは上記加算信号が加えられた共振周波数ｆ０１＝１３５Ｈｚの振動器６の振動力時間波形を示す。また、図２２Ａはｆ２＝１２５Ｈｚ、図２２Ｂは１４５Ｈｚのそれぞれの振動力時間波形を示す。振動器６の共振周波数が製造や、被振動装置への取付条件、使用条件で変動しても、帯域幅の広いポイント周波数により駆動されるため、安定的な振動力が実現される。
【０１０６】
なお、振動器６の振動力特性はサスペンションと磁気回路部で構成される機械共振のＱ値により異なる。図２４はＱ値の異なる線形サスペンションの力周波数特性を示す。ＩＶはＱ＝５、ＶはＱ＝１０、ＶＩはＱ＝２０である。なお、前記図２０の特性はＱ＝２０である。図２５Ａ〜２５ＣはＱ値の異なる振動器６に８ポイント信号を印加した場合の振動力の時間波形を示す。同図において、図２５ＡはＱ＝５、図２５ＢはＱ＝１０、図２５ＣはＱ＝２０であり、Ｑが小さい場合は力特性の周波数特性がより平坦となってくるため、ポイント周波数は少なくして、例えばＱ＝５以下では４ポイントあるいは２ポイントとするほうが、加算信号の波形の電圧レベル変動が少なくて、大きな振動が得られるものである。またＱが１０以上の場合、共振周波数でのレベルは高くかつ鋭くなるが、８個以上のポイント周波数で共振周波数の上下帯域を含む周波数低域にポイント周波数を配分すれば、例えばＱ＝２０とＱ＝３０では、共振周波数の極狭い帯域では振動力に差があるが、数Ｈｚ、上下周波数離れれば、それ以上、あるいはそれ以下の周波数帯域で同じ振動レベルとなるため、複数のポイント周波数の合成で作られる信号で駆動した場合、その振動力には大きな差異が生じない。すなわち、線形サスペンションでは、共振のＱの値により合成するポイント周波数の個数を最適に選ぶことが望ましい。なお、Ｑ値は振動器６の設計に依存されるが、Ｑを小さくする手段として、磁気回路を強力にして、ボイスコイルの電磁制動抵抗を大きくすること、あるいはサスペンションの材料として内部損失の大きな制振材料を用いて機械抵抗を増大することが有効であるが、電磁制動抵抗を大きくするには、磁気回路が大きくなり、小型の振動器６を実現することは困難となってくる。また、機械抵抗を大きくすると共振のレベルが抑えられて、大きな振動力を得るには大きな電気入力が必要となり、効率の低下した振動器６となる。非線形サスペンションでは、電磁制動抵抗が大きくなくてもサスペンションの跳躍現象により振動力の大きな周波数範囲が広くなるため、線形サスペンションよりも小型で大きな振動力が得られる振動器６が実現できるが、本発明の信号は、サスペンションの線形性にかかわらず有効である。
【０１０７】
信号波形を変化させることにより振動特性を容易に変更できる。これにより、現在呼出音がいろいろなメロディーを用いるのと同様に、いろいろな振動で呼出が可能となる。例えば、電話の相手により振動モードを変えることが可能である。
【０１０８】
図２６Ａ、２６Ｂは非線形サスペンションを用いた振動器６に５Ｈｚ間隔の８ポイント信号を加算して印加した場合で、図２６Ａが信号の電圧時間波形、図２６Ｂが振動力の時間波形である。図２７Ａ、２７Ｂは同じ振動器６に４Ｈｚ間隔の８ポイント信号を印加した場合で、図２７Ａが信号の電圧時間波形、図２７Ｂが振動力の時間波形である。本例ではポイント周波数の間隔を変えることにより振動力の特性を変えることができる。このように、本発明により振動モード切替が容易に実現できるものである。なお、振動モード切替は、ポイント周波数の個数、各信号の位相等により変更できるものである。
【０１０９】
また、入力信号の時間波形は連続的なもので示しているが、定められた時間間隔で間欠的に繰り返す信号でもよい。この場合、静止と振動が繰り返され人の体感には振動による呼出がより明確になるものである。
【０１１０】
（実施の形態３）
本発明の電気−機械−音響変換装置２００の第２の実施の形態について、図２８を用いて説明する。なお、説明にあたっては実施の形態１と同一部分は同一番号を付し説明を省略する。即ち、本実施の形態においての実施の形態１との相違点は、電気信号発生装置７と並んで音響信号発生装置１２を設け、スイッチＳＷ２によりそれぞれからの電気信号を切り替えて振動器６に加えるものである。
【０１１１】
電気信号発生振動器７は振動を安定に発生させる掃引周波数や複数個のポイント周波数の信号で構成され、その他に音声や音楽信号を発生させることも可能であるが、回路構成が複雑になる。そこで、振動の動作をさせる場合は、スイッチＳＷ２で電気信号発生装置７からの信号をＯＮとし、音楽や音声の音響信号の再生時には音響信号発生装置１２からの信号を、スィッチＳＷ２でＯＮとするものである。これにより、振動と音響の動作が分離され、回路構成が簡略化されるものである。
【０１１２】
なお、電気信号発生装置７は任意の信号波形が記録再生できる半導体メモリー等の記録媒体であっても良く、ＤＳＰ（Ｄｉｇｉｔａｌｓｉｇｎａｌｐｒｏｃｅｓｓｏｒ）であっても良い。
【０１１３】
（実施の形態４）
本発明の携帯端末装置の第３の実施の形態について、図２９から図３０を用いて説明する。なお、説明にあたっては実施の形態１と同一部分は同一番号を付し説明を省略する。図２９は実施の形態１で説明した振動器６を搭載した携帯端末装置の１つである携帯電話３００の斜視図である。図３０は実施の形態１の振動器６を用いた携帯電話３００の要部のブロック回路図である。
【０１１４】
図２９によると、携帯電話３００本体の外ケース１３に振動器６が取り付けられている。図３０によると、１４はアンテナ、１５は受信信号処理部、１６は電気信号発生装置、ＳＷ３は受信信号処理部１５、電気信号発生装置１６の電気信号を振動器６に切り替えるスイッチである。
【０１１５】
次に、動作について説明する。アンテナ１４は携帯電話の図示しない送信機から送られてきた着信信号を受ける。この着信信号は、着信を知らせる受信信号と送信者の話し声である受話音信号を含むものである。この着信信号は受信信号処理部１５で信号処理され、まず受信者に着信を知らせるための受信信号に応答して信号Ｋを発生する。信号Ｋが発生されると通常はＯＦＦ状態のスイッチＳＷ３が受信信号処理部１５あるいは電気信号発生装置１６にＯＮされる。スイッチＳＷ３が電気信号発生装置１６に接続されると、実施の形態１で述べた周波数信号が発生して、この信号により振動器６の非線形サスペンションで支持された磁気回路部が振動して、この振動が携帯電話３００を振動させ、振動による呼び出しとなるバイブレータとして動作するものである。あるいは、電気信号発生装置１６から発生する信号が、呼び出し音の場合は振動器６は音響再生用のスピーカとして動作するものである。受信者が振動あるいは呼び出し音により受信を知り、携帯電話を受信可能な状態にすると、受信信号処理部１５は信号Ｋにより、スイッチＳＷ３を切り替えて受信信号処理部１５にＯＮされる。受信信号処理部１５からの信号は受話音であり、振動器６はレシーバ、或いは携帯端末を離れた距離に設置して、例えば受話音を聴く拡声用スピーカとして動作するものである。
【０１１６】
以上のように、上記実施の形態の携帯電話３００は振動器６に掃引周波数、あるいはポイント周波数を電気信号発生装置１６により発生して、振動器６から取り出せる大きな振動量を効率よく取り出せるため、携帯電話で大きな問題となるバッテリーの消費電力を低減できるものである。
【０１１７】
なお、前記例では電気信号発生装置１６が呼び出し音を発生するとしたが、受信信号処理部１５からの信号が呼び出し音を発生させるものでも良い。この場合、受信信号処理部１５は呼び出し音、受話音さらには拡声用スピーカ音を発生するものでる。
【０１１８】
（実施の形態５）
本発明の携帯端末装置の第４の実施の形態について、図３１を用いて説明する。
【０１１９】
図３１は実施の形態１で説明した振動器６を用いた携帯電話４００の要部のブロック回路図である。また、ここでは図示しないが、実施の形態３と同様に、振動器６は、携帯電話本体に取り付けられているものである。図３１によると、１４はアンテナ、１７は受信信号処理部、１６は電気信号発生装置、１８は信号合成手段、スイッチＳＷ４、ＳＷ５は受信信号処理部１７と信号合成手段１８及び、電気信号発生装置１６と信号合成手段１８との間に設けた電気信号のスイッチ、またＳＷ６は信号合成手段１８と振動器６との間に設けた電気信号のスイッチである。
【０１２０】
次に、動作について説明する。アンテナ１４は携帯電話の図示しない送信機から送られてきた着信信号を受ける。この着信信号は、着信を知らせる受信信号と送信者の話し声である受話音信号を含むものである。この着信信号は受信信号処理部１７で信号処理され、まず受信者に着信を知らせるための受信信号に応答して信号Ｋ１とＫ２、Ｋ３を発生する。信号Ｋ１、Ｋ２、Ｋ３が発生されるとスイッチＳＷ４、ＳＷ５、ＳＷ６が制御されて、ＯＮ，ＯＦＦの動作が選択される。
【０１２１】
信号Ｋ１がＯＦＦ、信号Ｋ２がＯＮ、信号Ｋ３がＯＮの信号を発生すると、スイッチＳＷ４がＯＦＦ、スイッチＳＷ５がＯＮ、スイッチＳＷ６がＯＮとなって、電気信号発生装置１６からの振動信号が信号合成手段１８に入力される。受信信号処理部１７からの信号はＯＦＦ状態であるため、信号合成手段１８は電気信号発生装置１６からの振動信号を振動器６に印加する。
【０１２２】
この信号により振動器６の非線形サスペンションで支持された磁気回路部が振動して、この振動が携帯電話を振動させ、振動による呼び出しとなるバイブレータとして動作するものである。同様に、信号Ｋ１がＯＮ、信号Ｋ２がＯＦＦ、信号Ｋ３がＯＮの信号を発生すると、スイッチＳＷ４がＯＮ、スイッチＳＷ５がＯＦＦ、スイッチＳＷ６がＯＮとなって、受信信号処理部１７からの音響信号が信号合成手段１８に入力される。電気信号発生装置１６からの信号はＯＦＦ状態であるため、信号合成手段１８は受信信号処理部１７からの音響信号を振動器６に印加する。この場合は、振動器６は音響再生用のスピーカとして動作するものであり、呼び出し音、レシーバ或いは拡声用スピーカとして機能する。さらに、信号Ｋ１がＯＮ、信号Ｋ２がＯＮ、信号Ｋ３がＯＮの信号を発生すると、スイッチＳＷ４がＯＮ、スイッチＳＷ５がＯＮ、スイッチＳＷ６がＯＮとなって、受信信号処理部１７からの音響信号及び電気信号発生装置１６からの振動信号が信号合成手段１８に同時に入力される。従って、受信信号処理部１７からの音響信号及び電気信号発生装置１６からの振動信号が信号合成手段１８で合成され振動器６に印加される。これにより、振動器６は例えば着信の呼び出しを、振動と音の両方で知らせることが可能となるものである。或いは、受話中に他の人からの電話を受信した場合でも、振動によって、第３者からの着信を知ることが可能となる。この場合、振動は受話音を妨げることがないので、電話の音質を劣化させることなく、着信と受話という複合動作を有する携帯端末装置が実現できるものである。
【０１２３】
なお、本実施の形態１〜５では振動器６は磁場内に挿入されたボイスコイルに発生する磁気力を用いる動電型方式であったが、圧電型、電磁型等の変換器方式でも、その振動力特性が同様な非線形特性を有するなら同様の構成が可能である。
【０１２４】
【発明の効果】
以上のように、本発明の電気−機械−音響変換装置の構成は、振動器に非線形サスペンションを用いることにより、幅広い周波数帯域で大きな振動力を実現するものである。また、線形サスペンションを用いた場合でも、複数のポイント周波数を加算合成した信号を入力することにより、振動器の振動特性のばらつきによる振動力の大きな変動をなくして、また駆動回路の簡略化を可能として、常に安定した振動力が効率よく得られるものである。これにより、携帯電話等への応用を可能として、携帯端末装置の消電力化、さらには、回路の簡略化による省スペース化、軽量化が実現できるものである。
【図面の簡単な説明】
【図１】本発明の実施の形態１の電気−機械−音響変換装置要部のブロック回路図
【図２】同要部である振動器の一具体例の分解斜視図
【図３Ａ】同要部である振動器のバッフルを除いた状態の上面図
【図３Ｂ】振動器のバッフルを除いた状態の側断面図
【図４】実施の形態１の振動器サスペンションの変位−力特性を示す図
【図５】同サスペンションの変位−スティフネス特性を示す図
【図６】実施の形態１の振動器の力周波数特性を示す図
【図７】同力周波数特性を示す図
【図８】線形サスペンションを用いた従来の振動器の力周波数特性を示す図
【図９】実施の形態１の第２の非線形サスペンションの変位−スティフネス特性を示す図
【図１０】実施の形態１の振動器の第２の力周波数特性を示す図
【図１１】実施の形態１の振動器の力周波数特性と入力周波数ポイントを示す図
【図１２】実施の形態１の振動器の力周波数特性を示す図
【図１３Ａ】実施の形態１の電気−機械−音響変換装置で単独周波数入力時の入−出力特性を示す図
【図１３Ｂ】実施の形態１の電気−機械−音響変換装置で単独周波数入力時の入−出力特性を示す図
【図１３Ｃ】実施の形態１の電気−機械−音響変換装置で単独周波数入力時の入−出力特性を示す図
【図１３Ｄ】実施の形態１の電気−機械−音響変換装置で単独周波数入力時の入−出力特性を示す図
【図１４Ａ】実施の形態１の電気−機械−音響変換装置で合成周波数信号入力時の入−出力特性を示す図
【図１４Ｂ】実施の形態１の電気−機械−音響変換装置で合成周波数信号入力時の入−出力特性を示す図
【図１５】実施の形態１の振動器の力周波数特性の変動を示す図
【図１６Ａ】複数の周波数信号を同相で加算した合成信号の時間波形の図
【図１６Ｂ】同信号により得られる振動力特性の時間波形の図
【図１７Ａ】実施の形態１の電気−機械−音響変換装置で複数の周波数信号の位相を調整して加算した合成信号の時間波形の図
【図１７Ｂ】実施の形態１の電気−機械−音響変換装置で同信号により得られる振動力特性の時間波形の図
【図１８Ａ】実施の形態１の電気−機械−音響変換装置で振動器の力周波数特性が低域側に変動した場合の振動力特性の時間波形の図
【図１８Ｂ】実施の形態１の電気−機械−音響変換装置で振動器の力周波数特性が高域側に変動した場合の振動力特性の時間波形の図
【図１９】実施の形態２の線形サスペンションの平面図
【図２０】実施の形態２の線形サスペンションを用いた振動器の力周波数特性を示すグラフ
【図２１Ａ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２１Ｂ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２２Ａ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２２Ｂ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２３】実施の形態２の電気信号発生装置のブロック図
【図２４】実施の形態２のＱ値の異なる線形サスペンションの力周波数特性を示すグラフ
【図２５Ａ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２５Ｂ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２５Ｃ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２６Ａ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２６Ｂ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２７Ａ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２７Ｂ】実施の形態２の振動力特性の時間波形を示すグラフ
【図２８】本発明の実施の形態３の電気−機械−音響変換装置要部のブロック回路図
【図２９】本発明の電気−機械−音響変換装置を搭載した実施の形態４の携帯電話の斜視図
【図３０】同実施の形態４の電気−機械−音響変換装置要部のブロック回路図
【図３１】同実施の形態５の電気−機械−音響変換装置要部のブロック回路図
【図３２】従来の振動器の構造断面図
【図３３】同振動器の力周波数特性を示す図
【符号の説明】
６振動器
７電気信号発生装置
８磁気回路部
９，１０サスペンション
１２電気音響信号発生装置
１３携帯電話
１４アンテナ
１５受信信号処理部
１８信号合成手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electro-mechanical-acoustic conversion device used for generating a ringing sound or ringing vibration of a mobile terminal such as a mobile phone, a pager, and a PHS (Personal Handy Phone Set), and a driving method thereof.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in portable terminal devices such as mobile phones, pagers, and PHS (Personal Handy Phone Set), a plurality of electro-mechanical-acoustic transducers are attached in the main body, and an electric signal generator is connected to bell sound. It has been used as a means of selectively generating vibrations and notifying incoming calls.
[0003]
In order to reduce the size and weight of a mobile terminal device, a mobile phone using an electro-mechanical-acoustic converter that realizes sound generation and vibration in one unit has been devised. Japanese Patent Application Laid-Open No. 8-275293 for Motorola It is disclosed in the publication.
[0004]
The electro-mechanical-acoustic conversion device 3200 in FIG. 32 according to the prior art is configured as follows. The movable mass unit 1 is supported by a planar nonlinear spring member 2. An electromagnetic coil 4 is housed inside the coil mold 3, and a permanent magnet 5 is fixed to an outer peripheral portion of the movable mass portion 1 and disposed at an opposing portion of the electromagnetic coil 4. Although not shown here, the outer periphery of the coil mold 3 is attached to a sound board (for example, a case of a mobile phone).
[0005]
[Problems to be solved by the invention]
In the electro-mechanical-acoustic conversion device 3200, when a drive signal is applied to the electromagnetic coil 4, an alternating magnetic field is generated, and an alternating excitation force is generated between the permanent magnet 5 and the movable mass portion 1 vibrates. Is transmitted to the sound board, and a vibration call can be made when a mobile phone is received. Further, the sound generation operates on the same principle. Here, in order to obtain a large vibration force, a planar nonlinear spring member is used as the support member 2 of the movable mass portion 1. FIG. 33 shows the displacement frequency characteristics of the planar nonlinear spring member. It is known that a nonlinear spring member exhibits a vibration characteristic called a jump phenomenon (for example, Yoshihisa “Speaker”, Riko Research Institute (March 1973)). This is a phenomenon in which the displacement characteristic of the nonlinear spring member changes as A → B → C → D as the frequency is increased, and changes as D → C → E → F → A as the frequency is decreased.
[0006]
Therefore, in the conventional electro-mechanical-acoustic transducer 3200, the characteristics change depending on the direction of the frequency signal to be applied in the frequency range of F to B and stable vibration cannot be obtained. Therefore, the characteristics do not change in the direction of the frequency signal. A drive signal for sweeping the frequency range of ~ F has been used. However, in the frequency range of A to F, the vibration force increases at the frequency F, but the vibration force extremely decreases at the frequency A, and the vibration output during the frequency sweep is not always efficient. In particular, in mobile information terminal devices such as mobile phones, since the drive power supply is a battery, it is strongly required for long-term use to improve the efficiency of the converter as much as possible to save power. It is.
[0007]
The present invention solves the above-described problems and provides an electro-mechanical-acoustic converter capable of obtaining a stable and highly efficient vibration output.
[0008]
[Means for Solving the Problems]

[0019]
  Another drive circuit according to the present invention is a drive circuit for driving a vibrator having a mechanical vibration system having a predetermined vibration force frequency characteristic, and the mechanical vibration system increases and decreases in frequency within a predetermined frequency range. The frequency range includes a low-frequency limit frequency that represents the lowest frequency in the frequency range and a high-frequency limit frequency that represents the highest frequency in the frequency range, and the drive circuit Outputs a first signal having a frequency included in the frequency range and a second signal having a frequency lower than the lower limit frequency to the vibrator, and the second signal is the same as the first signal.SometimesOutput to the vibrator, the vibrator having a function of converting an electrical signal into at least one of sound and vibration.The vibrator includes a magnetic circuit unit and at least one suspension, and the suspension is a non-linear suspension.This achieves the above object.

[0022]
When the stiffness S is expressed by a multi-order function of the displacement X, the suspension²A term may have a value.
[0023]
The drive circuit may be an electrical signal generator that generates a vibration frequency signal or a sound electroacoustic signal.
[0024]
  Said1The signal may include a swept signal whose frequency varies continuously.

[0025]
  Said1The signal may include a plurality of point frequency signals.

[0026]
At least one of the first signal and the second signal may include an ascending signal whose frequency changes from lower to higher.
[0027]
The first signal includes a sweep signal having a continuously changing frequency, and the first signal has a first return frequency from rising to falling and a second return frequency from falling to rising, The first folding frequency may be lower than the high frequency limit frequency, and the second folding frequency may be higher than the low frequency limit frequency.
[0028]
The first signal may include at least one point frequency signal.
[0029]
The drive circuit may output a combined signal obtained by adding the first signal and the second signal to the vibrator.
[0030]
The drive circuit may output a combined signal obtained by adding the first signal and the second signal while changing the phase to the vibrator.
[0031]
At least one of the first signal and the second signal may include a sine wave signal.
[0032]
At least one of the first signal and the second signal may include a rectangular wave signal.
[0033]
The driving circuit may include a limiter that limits a peak of the output voltage of the combined signal.
[0034]
The synthesized signal is a sine wave signal, and the synthesized signal is composed of two adjacent frequency signals as one set of signals, the first set is synthesized as a reverse phase, the second set is synthesized as a positive phase, It may be a frequency signal configured by combining a plurality of first set and second set signals as one set.
[0038]
  Another electromechanical acoustic transducer according to the present invention includes a vibrator having a mechanical vibration system having a predetermined vibration force frequency characteristic, and a drive circuit that drives the vibrator. The frequency range has different vibration force frequency characteristics in frequency rise and fall, the frequency range being a low frequency limit frequency representing the lowest frequency in the frequency range and a high frequency limit representing the highest frequency in the frequency range. The drive circuit outputs a first signal having a frequency included in the frequency range and a second signal having a frequency lower than the low-frequency limit frequency to the vibrator, and the second signal. Is the same as the first signalSometimesOutput to the vibratorThe vibrator includes a magnetic circuit unit and at least one suspension, and the suspension is a non-linear suspension.This achieves the above object.
When the stiffness S is expressed by a multi-order function of the displacement X, the suspension ² It may be a nonlinear suspension whose term has a value.

[0039]
The drive circuit outputs a combined signal obtained by adding the first signal and the second signal to the vibrator, and the drive circuit outputs a frequency, a frequency interval, and a phase between the first signal and the second signal. The combined signal may be selectively changed by changing at least one of the voltage level and the voltage level.
[0047]
  Another portable terminal device according to the present invention includes a vibrator having a mechanical vibration system having a predetermined vibration force frequency characteristic, an antenna that receives an incoming signal and a received signal, and an electric signal obtained by performing signal processing on the incoming signal. Receiving signal processing means for outputting to the vibrator, and a drive circuit for driving the vibrator, and the mechanical vibration system has different vibration force frequency characteristics when the frequency rises and falls within a predetermined frequency range. The frequency range includes a low-frequency limit frequency that represents the lowest frequency in the frequency range and a high-frequency limit frequency that represents the highest frequency in the frequency range, and the drive circuit includes a frequency included in the frequency range. And a second signal having a frequency lower than the low-frequency limit frequency is output to the vibrator, and the second signal is the same as the first signal.SometimesOutput to the vibratorThe vibrator includes a magnetic circuit unit and at least one suspension, and the suspension is a non-linear suspension.This achieves the above object.
  When the stiffness S is expressed by a multi-order function of the displacement X, the suspension ² It may be a nonlinear suspension whose term has a value.

[0048]
Based on the output of the received signal processing means, it may further comprise switching means for connecting the vibrator to either the drive circuit or the received signal processing means.
[0049]
You may further provide the signal synthetic | combination means which synthesize | combines the said electric signal output by the said received signal processing means, and the output of the said drive circuit.
[0050]
A first switch provided between the reception signal processing means and the signal synthesis means; a second switch provided between the drive circuit and the signal synthesis means; and the signal synthesis means and the vibrator. You may further provide the 3rd switch provided in between.
[0051]
  The drive circuit outputs a combined signal obtained by adding the first signal and the second signal to the vibrator, and the drive circuit outputs a frequency, a frequency interval, and a phase between the first signal and the second signal. The combined signal may be selectively changed by changing at least one of the voltage level and the voltage level.
  The drive circuit according to the present invention includes:A drive circuit for driving a vibrator having a mechanical vibration system having a predetermined vibration force frequency characteristic, wherein the mechanical vibration system has different vibration force frequency characteristics when the frequency rises and falls within a predetermined frequency range. The frequency range includes a low-frequency limit frequency that represents the lowest frequency in the frequency range and a high-frequency limit frequency that represents the highest frequency in the frequency range, and the driving circuit includes a frequency included in the frequency range. And a second signal having a frequency lower than the lower limit frequency is output to the vibrator, and the second signal is simultaneously with the first signal or before the vibrator. The vibrator has a function of converting an electrical signal into at least one of sound and vibration, and the vibrator includes a magnetic circuit unit and at least one suspension, and the suspension If emissions are, that represents the stiffness S in multi-order function of the displacement X, X ² A non-linear suspension whose term has a value, thereby achieving the above objective.

[0056]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0057]
(Embodiment 1)
FIG. 1 is a block circuit diagram of an electro-mechanical-acoustic conversion device 100 according to Embodiment 1 of the present invention. According to the figure, 6 is a vibrator, 7 is an electric signal generator, and SW1 is a signal selector switch.
[0058]
2, 3A, and 3B show a configuration example of the vibrator 6 used in the electro-mechanical-acoustic converter 100 of the present invention. 2 is an exploded perspective view, FIG. 3A is a top view with the baffle removed, and FIG. 3B is a side sectional view.
[0059]
According to FIGS. 2, 3A and 3B, reference numeral 8 denotes a magnetic circuit part composed of a yoke, a magnet and a plate integrally formed with a weight part, and 9, 10 are respectively coupled above and below the magnetic circuit part 8. A pair of upper and lower suspensions that extend from the upper and lower suspensions 9 and 10 to the opposite sides of the upper and lower suspensions 9 and 10 at different positions between the upper and lower suspensions 9 and 10, respectively.

Feet

9a, 9b, 10a, 10b are provided. Here, the weight of the magnetic circuit unit 8 is 3 g.
[0060]
11 is a plastic support member having an upper opening portion 11e and a lower opening portion 11f and provided with receiving

portions

11a, 11b, 11c, and 11d to which the

feet

9a, 9b, 10a, and 10b are respectively coupled. , 12 is a diaphragm made of a titanium material or a plastic, which is a non-magnetic material, whose outer peripheral edge is coupled to the lower opening 11f of the support member 11. The voice coil 13 is bonded to the center of the diaphragm 12 and the end thereof is inserted into the magnetic gap 8a of the magnetic circuit portion 8 supported by the upper and lower suspensions 9 and 10.
[0061]
Reference numeral 14 denotes a baffle attached to the upper opening 11 e of the

support member

11, and 11 g denotes an external input terminal connected to the lead wire of the voice coil 13.
[0062]
The material of the upper and lower suspensions 9 and 10 is a spring material such as stainless steel or beryllium alloy, and is designed so that the stiffness characteristics with respect to the amplitude displacement amount are non-linear depending on the size and shape. Here, for example, the

legs

9a, 9b, 10a, 10b have a length of 8 mm, a width of 1 mm, and a thickness of 0.085 mm.
[0063]
FIG. 4 shows the displacement-force characteristics of the upper and lower suspensions 9 and 10. This characteristic is a characteristic when the

legs

9a, 9b, 10a and 10b of the upper and lower suspensions 9 and 10 are fixed and a force is applied to the magnetic circuit part 8 to which the central part is coupled. The vertical axis represents the force. FIG. 5 shows the stiffness characteristics of the suspensions 9 and 10 obtained from the results shown in FIG. 4. The horizontal axis represents displacement and the vertical axis represents stiffness. The suspensions 9 and 10 exhibit nonlinearity in which the stiffness value increases as the displacement increases. FIG. 6 shows the characteristics of the vibration force generated in the vibrator 6 when a frequency signal is input to the vibrator 6 composed of the nonlinear suspensions 9 and 10 as described above (where the mass of the magnetic circuit unit 8 is About 3 g). FIG. 6 shows force characteristics when the frequency is increased from a low frequency to a high frequency and when the frequency is decreased from a high frequency to a low frequency. First, when the frequency is continuously increased, the force changes from a → b → c → d.
On the other hand, when the frequency is continuously lowered, the state changes from d → c → e → f → a. This result is almost the same phenomenon as the conventional nonlinear suspension explained in FIG. 33, and is known as a jumping phenomenon of the nonlinear suspension.
[0064]
The operation of the electro-mechanical-acoustic converter using the vibrator 6 composed of the nonlinear suspension as described above will be described.
[0065]
The frequency signal generated by the electrical signal generator 7 is input to the vibrator 6 when the signal switching switch SW1 is turned on. The frequency signal is a force characteristic of the nonlinear suspensions 9 and 10 shown in FIG. 6, where a point f showing a different characteristic between the rise and fall of the frequency is a low frequency limit frequency fL, and a point b is a high frequency limit frequency fH. When the frequency range is Wb, at least one of the frequency signals includes a frequency higher than fL and lower than fH. In the frequency range Wb, the force generated by the vibrator 6 is maximum. For example, when only a 140 Hz signal that provides a large force in the frequency range Wb of FIG. 6 is added, the force value is obtained by decreasing the frequency. It becomes the value of the point g which becomes 140 Hz on the characteristic, and does not become the point h which is the force value of 140 Hz obtained by the increase in the target frequency. Similarly, even if the frequency is lowered such that b → f in Wb, the force value does not reproduce the characteristic f → b of the rising sweep. In order to stably secure the characteristics from f to b where a large force is obtained, at least one frequency lower than fL, which is the lower limit frequency of the frequency range Wb, is added as an input signal to the vibrator 6. Is.
[0066]
Further, as shown in FIG. 7, the sweep signal first rises as an initial signal from point i, which is a frequency lower than fL, toward h located within the frequency of Wb, and at j located within the frequency of Wb. If the signal returns to h again and repeats the sweep between h and j (initially i → h, then h → j → h → j → h), the sweep has a large vibration force. Since it is performed within the range Wb, a stronger vibration force can be secured.
[0067]
In the frequency signal, the frequency sweep from falling to rising is repeated after the frequency rising sweep from i to h, but the frequency rising sweep from i is stopped at frequency point h and the frequency is fixed at frequency point h. Even if it is applied continuously, the vibration force does not decrease to the vibration force (point g) when the frequency is lowered as in the case of inputting the frequency alone, and maintains a large vibration force. is there. Therefore, if the frequency at which the frequency rising sweep is stopped is set closer to the high band limit frequency fH of Wb, a larger vibration force can be obtained continuously.
[0068]
Further, the stiffness characteristic of the suspension constituting the vibrator 6 is particularly important. FIG. 8 shows the vibration force characteristics of the vibrator 6 having a magnetic circuit portion supported by a suspension having no nonlinearity. In the linear suspension, the characteristic does not change with an increase or decrease of the frequency, but the frequency at which the vibration force increases becomes only the resonance frequency f0 of the mechanical system constituted by the stiffness of the suspension and the mass of the magnetic circuit unit, and the resonance frequency f0. When was removed, the vibration force was extremely reduced. For this reason, a means for detecting a resonance frequency that matches the frequency of the drive signal with the resonance frequency f0 of the mechanical system is required. Alternatively, it is necessary to strictly manage the resonance frequency during the manufacturing process so that the resonance frequency of the vibrator 6 matches the predetermined driving frequency. The vibration force characteristic of the nonlinear suspension shown in FIG. 6 has a large force in a wide frequency band of f → b, not in a narrow band like f0 of the linear suspension. In order to obtain a large force in such a wide frequency band, special non-linear characteristics of the suspension are required. For example, in order to obtain the characteristics shown in FIG. 6, the displacement (x) -force (F) characteristics shown in FIG.
[0069]
[Expression 1]

[0070]
And the displacement (x) -stiffness (S) characteristic shown in FIG.
[0071]
[Expression 2]

[0072]
It can be expressed. For example, in (Equation 2), S₁, S₂, S_ThreeAs the value of
S₁= 503.6
S₂= 0
S_Three= 5.5 × 10⁸
If the displacement x = 1 mm, the value in (Equation 2) is as shown in (Table 1).
[0073]
[Table 1]

[0074]
That is, the non-linear term x squared term (S_Threex²) Is a factor that causes different characteristics when the frequency rises and falls, and allows generation of a large force in a wide frequency band.
[0075]
Therefore, in the vibrator 6 used in the electro-mechanical-acoustic converter 100 of the present invention, at least one of the suspensions 9 and 10 needs to have a value in the square term of x. Therefore,
S₁= 0
S₂= 0
S_Three= 8.0 × 10⁸
As the S of stiffness represented by (Equation 2)₁, S₂Is the term S_Three9 is small and is substantially only the term S3, the displacement-stiffness characteristic is as shown in FIG. 9, and the vibration force characteristic generated by the vibrator 6 is as shown in FIG. Thus, the frequency range f ′ to b ′ in which the vibration force characteristics are different depending on the rise and fall of the frequency is wider than the frequency ranges f to b shown in FIGS. 6 and 7, and the inclination of the vibration force characteristic when the frequency is raised is 6. Slighter than the inclination shown in FIG. Therefore, the change in the magnitude of the force with respect to the frequency change of the input signal is reduced, and a more stable and large force can be obtained.
[0076]
In the above two examples, S₂However, even if this term is not 0, the jumping phenomenon that has different characteristics depending on the rise and fall of the frequency occurs in substantially the same manner.
Furthermore, the same applies when there is a higher-order term.
[0077]
In addition, a nonlinear suspension having a value in the square term of x is realized by a stiffness characteristic in which the amplitude is limited as the displacement increases. For example, this nonlinearity reduces the suspension length by reducing the suspension length. It can be realized relatively easily by limiting or using a material with little elongation.
[0078]
Furthermore, in the electro-mechanical-acoustic converter 100 of the present invention, the frequency signal generated by the electric signal generator 7 applied to the vibrator 6 may be a plurality of point frequencies instead of the sweep frequency in which the frequency continuously changes. . The point frequency desirably includes at least one signal lower than the low-frequency limit frequency fL of the region Wb as the initial input frequency. FIG. 11 shows an example of the point frequency. First, the point frequency is changed from P1 to P1, then P2, P3, P4, and P5, and applied to the vibrator 6. If a signal is continuously applied at this frequency P5 while being fixed at the last frequency P5, it is possible to continuously output a large vibration force from the vibrator 6. Alternatively, it may be increased in the order of P1, P2, P3, P4, and P5, and the increase and decrease may be repeated periodically in the region Wb, P5, P4, P3, P4, and P5. When the point frequency is within Wb, a stable operation cannot be obtained if the frequency width is too wide as P1 to P5. Therefore, the initial frequency and the maximum frequency within the Wb band as P1 → P3 → P5. It is desirable to drive by complementing with a plurality of point frequencies. However, even if the initial frequency P2 is lower than the frequency fL and the point frequency is relatively close to fL, such as P2 → P3, and the point frequency is relatively close to fL, the signal of the point frequency interpolated between them is It is not necessary.
[0079]
As described above, the electro-mechanical-acoustic conversion device 100 according to the embodiment can efficiently obtain a large vibration force over a wide frequency band by the vibrator 6 using the nonlinear suspension.
[0080]
The waveform of the signal is preferably a sine wave, but the same effect can be expected even if the fundamental frequency is a rectangular wave signal that satisfies the above frequency condition. In this case, since a harmonic component is added to the voice coil 13 and there is a high possibility that an unnecessary sound is reproduced at the time of vibration, a high region that cuts a high region between the electric signal generator 7 and the vibrator 6 is obtained. It is desirable to insert a cut filter 151.
[0081]
Further, if the input signal from the electrical signal generator 7 applied to the voice coil 13 is a voice or music signal containing a high frequency component, the diaphragm 12 vibrates and operates as a speaker, enabling sound reproduction. To do. In this case, if the lower limit of the acoustic signal is made higher than the lower limit frequency fL of the region Wb, the magnetic circuit unit 8 hardly vibrates, and only the diaphragm 12 vibrates and generates sound. This is useful when you want to make sound playback function individually. The frequency signal generated by the electrical signal generator 7 is a combined signal obtained by adding a frequency included in the frequency range Wb and a plurality of signals including at least one frequency lower than the frequency range Wb.
[0082]
The operation of the electro-mechanical-acoustic converter 100 composed of the electric signal generator 7 that generates the frequency signal as described above and the vibrator 6 having a nonlinear suspension will be described.
[0083]
A frequency signal from the electrical signal generator 7 is input to the vibrator 6. The frequency signal is obtained by adding, for example, a frequency point t within a frequency range Wb and a frequency point s lower than Wb, which show different characteristics in the force characteristics of the nonlinear suspensions 9 and 10 shown in FIG. It is a composite signal.
[0084]
First, FIG. 13A to FIG. 13D show vibration force characteristics when the frequency of the point s is f1 and the frequency of the point t is f2, and each frequency is input to the vibrator 6 alone. FIG. 13A is an input waveform at f2 where the peak value of the voltage is about twice that of f1, FIG. 13B is a vibration force waveform when f2 is input, FIG. 13C is an input waveform of f1, and FIG. 13D is a vibration force waveform when f1 is input. . F2 at the point t is a frequency signal within the frequency range Wb, and as shown in FIG. 12, the vibration output of the vibrator 6 becomes a large value due to the frequency rising sweep, but when this frequency signal is added alone, The vibration force decreases to the value of the characteristic point u obtained by sweeping down the frequency. The frequency f1 at the point s is a frequency lower than the frequency range Wb, and the vibration force does not change due to the frequency rising and falling sweeps. Therefore, even when the voltage peak value is half of f2, it is larger than when the f1 signal is input. Output waveform (vibration force waveform).
[0085]
Next, FIG. 14A and FIG. 14B show the vibration force characteristics when the composite signal of the two frequencies is input to the vibrator 6. 14A shows the input signal waveform, and FIG. 14B shows the vibration force waveform. The input waveform is amplitude-modulated and repeats periodic increase and decrease. The value of the vibration force waveform, which is the output waveform, increases and decreases with time, but the maximum value of the waveform is a large value that cannot be obtained by the single frequency input shown in FIGS. It can be seen that the vibration force at the point t of f2 obtained is obtained by the composite signal of two frequencies.
[0086]
If the signal generated by the electrical signal generator 7 is an acoustic signal such as a melody sound, a music signal, or a conversational sound, the diaphragm 12 to which the voice coil 13 of the vibrator 6 is joined vibrates to perform an acoustic reproduction operation. It is something to do. In this case, even if the low frequency component of the acoustic signal includes the frequency range Wb, since the vibration force is small, the functions of vibration and sound are substantially separated. On the other hand, if a vibration signal and a sound signal are input simultaneously, vibration and sound can be reproduced simultaneously. Thus, the vibrator 6 can be used for vibration and sound reproduction by combining a signal frequency band and a plurality of signals. It becomes possible to operate as a multi-function converter.
[0087]
Since the frequency signal in the frequency range Wb outputs a greater vibration force than the vibration force obtained with the frequency signal lower than the frequency range Wb, the input voltage level of the low frequency signal is within the frequency range Wb. In order to save power, it is desirable to set the voltage level to the minimum necessary level so that the vibration force by the frequency signal can be obtained stably. In this embodiment, the frequency signal is two sine waves, but the same effect can be obtained when two or more sine waves are used. Each voltage level is set based on the same concept as in this embodiment. Is. Further, the signal waveform may be a composite signal of two rectangular waves whose fundamental periods satisfy the above-mentioned frequency condition. However, since the distorted sound is reproduced from the diaphragm 12 by the harmonic component included in the signal, the signal waveform is high. It is desirable to insert a high-cut filter that cuts the sound range in front of the vibrator 6.
[0088]
Further, FIG. 15 shows L, M, and H fluctuations in the vibration force frequency characteristics caused by manufacturing variations during mass production of the vibrator 6 having a nonlinear suspension. In this case, only the result of measurement with the frequency continuously increased is shown, but if the frequency is continuously decreased, each characteristic has a vibration different from the frequency increase as shown in FIGS. It shows the force characteristics, that is, the jumping phenomenon.
[0089]
Here, the frequency signal generated by the electrical signal generator 7 includes, for example, at least one frequency lower than the frequency range Wb in the characteristic of L in which the vibration force characteristic variation of the vibrator 6 moves to a lower frequency, This is a composite signal that includes at least one frequency higher than the frequency range Wb in the characteristic of H that has moved to the higher fluctuation, and is added by changing the phases of the plurality of frequency signals P1 to P8.
[0090]
The operation of the electro-mechanical-acoustic converter 100 composed of the electric signal generator 7 that generates the frequency signal as described above and the vibrator 6 having a nonlinear suspension will be described.
[0091]
A frequency signal from the electrical signal generator 7 is input to the vibrator 6. In the present example, the frequency signal is a characteristic of H in which the fluctuation of the vibration force characteristic of the vibrator 6 is moved to a higher fluctuation with a frequency lower than the frequency range Wb in the characteristic of L in which the fluctuation is moved to a lower frequency as the lowest frequency. A frequency higher than the frequency range Wb in FIG. 8 is set as the highest frequency, and the frequency is divided into equal intervals, and eight-point frequencies P1 to P8 are set.
[0092]
First, in order to make the effects of the present embodiment easier to understand, an electric signal and vibration when a signal obtained by adding 8 points of frequencies in phase is input to the vibrator 6 having the vibration frequency characteristic of M shown in FIG. The time waveform of the output characteristics is shown in FIGS. 16A and 16B. FIG. 16A is a time waveform of the electric signal, and FIG. 16B is a time waveform of the vibration output. The electric signal repeats the intensity with the frequency of the equal frequency interval of each frequency as a period (that is, 200 mS if the interval is 5 Hz), and the vibration output waveform also outputs a large vibration force at the beginning of the period according to the electric input. The vibration waveform is such that the vibration force is attenuated until the start period of. Although a large vibration force can be obtained periodically by this vibration waveform, it is more preferable that the large vibration force continues on the time axis.
[0093]
Next, the time waveform of the electrical signal and vibration output characteristics obtained by adding and combining the signals of the lowest frequency P1 and the adjacent frequency P2 in reverse phase, P3 and P4 in phase, P5 and P6 in phase, and P7 and P8 in phase Shown in 17A and 17B. FIG. 17A shows the time waveform of the electric signal, and FIG. 17B shows the time waveform of the vibration output. Compared with the electrical signal waveforms of FIGS. 16A and 16B, the voltage level strength cycle is shortened. Along with this, the vibration output waveform does not mean that the vibration force attenuates after a large vibration output, but the time during which a large vibration is obtained continues.
[0094]
Further, FIGS. 18A and 18B show vibration output time waveforms when the composite signal is applied to the characteristics L and H which are varied on the low frequency side and the high frequency side of the vibration characteristics shown in FIG. 18A shows the vibration output waveform when applied to the characteristic L, and FIG.
Similar to the characteristic M shown in FIG. 17B, a continuous vibration output waveform is obtained, and a stable vibration output can be obtained even when the vibration force characteristic of the vibrator 6 fluctuates.
[0095]
If the signal generated by the electrical signal generator 7 is an acoustic signal such as a melody sound, a music signal, or a conversational sound, the diaphragm 12 to which the voice coil 13 of the vibrator 6 is joined vibrates to perform an acoustic reproduction operation. It is something to do. In this case, even if the low frequency component of the acoustic signal includes the frequency range Wb, since the vibration force is small, the functions of vibration and sound are substantially separated. On the other hand, if a vibration signal and a sound signal are input simultaneously, vibration and sound can be reproduced simultaneously. Thus, the vibrator 6 can be used for vibration and sound reproduction by combining a signal frequency band and a plurality of signals. It becomes possible to operate as a multi-function converter.
[0096]
Further, the signal waveform may be a composite signal of a plurality of rectangular waves whose fundamental period satisfies the frequency condition, but since the distortion sound is reproduced from the diaphragm 12 by the harmonic component included in the signal, It is desirable to insert a high-cut filter 151 that cuts the sound range in front of the vibrator 6.
[0097]
As described above, the electro-mechanical-acoustic converter according to the present embodiment synthesizes the vibrator 6 using the non-linear suspension and the two adjacent frequency signals as one set of signals, and the first set as a reverse phase. The second set is synthesized in the positive phase, a plurality of the first and second sets of signals are further combined as one set, and the frequency interval of a plurality of point frequencies by a frequency signal formed by combining and adding them. Even if the frequency is wide, any frequency is included in the frequency range Wb where the vibration force due to the jump phenomenon is large, and a large vibration force can be obtained continuously by shortening the voltage strength cycle of the electric signal waveform. Furthermore, even when the vibration frequency characteristics of the vibrator 6 fluctuate, a stable vibration output can always be obtained if the frequency range of the point frequency is set so as to include a frequency band in which a large vibration force can be obtained. Furthermore, vibration and sound reproduction can be arbitrarily selected according to the frequency band of the applied signal.
[0098]
(Embodiment 2)
In the first embodiment described above, the suspension of the vibrator 6 is non-linear in which a jump phenomenon occurs. However, even in a linear type in which a jump phenomenon does not occur, the band including the upper and lower frequencies of the resonance frequency is the same as in the case of the non-linear suspension. A continuous vibration output can be obtained by inputting a synthesized signal synthesized from a signal included in the. Further, although the resonance frequency characteristic fluctuates even with a linear suspension, a stable vibration output can always be obtained by a plurality of frequency signals including a fluctuating frequency band, as in the case of non-linear.
[0099]
FIG. 19 shows a plan view of the linear suspension 130. The magnetic circuit portion 8 is fixed to the central portion 132, and the

foot portions

133 a and 133 b are fixed to the support member 11. The force-displacement characteristic of the suspension 130 becomes linear by increasing the length L of the arm 131 of the suspension.
[0100]
FIG. 20 shows force frequency characteristics of the vibrator 6 using the linear suspension 130. This figure shows characteristics I, II, and III when the resonance frequency is changed to f01, f02, and f03. Although not shown here, since the suspension 130 is linear, a jump phenomenon in which the characteristics are different in the frequency sweep direction does not occur.
[0101]
The change in the resonance frequency in FIG. 20 shows the variation in the characteristics of the vibrator 6.
Further, the down arrows P1 to P8 indicate point frequency signals to be applied. These point frequencies are set in a frequency range including the resonance frequencies f01, f02, and f03 of the characteristics I, II, and III.
[0102]
21A, 21B and 22A, 22B are time waveforms of vibration force characteristics when an 8-point signal whose phase is controlled is applied to the linear suspension 130. FIG. In this example, the weight of the magnetic circuit unit is 1.4 g, the resonance frequency f01 = 125 Hz of the mechanical resonance system composed of the linear suspension and the magnetic circuit unit, f02 = 135 Hz, f03 = 145 Hz, and the point frequencies P1 to P8 are 120 Hz. It is set at intervals of 5 Hz up to ˜155 Hz, and P2 and P6 are in reverse phase.
[0103]
FIG. 23 shows an example of the electrical signal generator 7. In the figure, reference numerals 101 to 108 are frequency signal generators, 110 to 117 are phase controllers, and 120 is a signal adder.
[0104]
First, the addition signals from P1 to P8 applied to the vibrator 6 are f1 = 120 Hz, f2 = 125 Hz, f3 = 130 Hz, f4 = 135 Hz, f5 = 140 Hz, f6 = 145 Hz, f7 = by the frequency generators 101-108. 150 Hz, f8 = 155 Hz is generated. These signals are input to the phase controllers 110 to 117, but f2 and f6 are delayed in phase by 180 degrees to have opposite phases, the other signals are in phase, and all signals are synthesized by the signal adder 120 and output. Is added to the vibrator 6.
[0105]
FIG. 21A shows the time waveforms of P1 to P8 added. FIG. 21B shows a vibration force time waveform of the vibrator 6 having the resonance frequency f01 = 135 Hz to which the addition signal is added. Moreover, FIG. 22A shows each vibration force time waveform of f2 = 125 Hz and FIG. 22B shows 145 Hz. Even if the resonance frequency of the vibrator 6 fluctuates depending on manufacturing, attachment conditions to the apparatus to be vibrated, and use conditions, a stable vibration force is realized because it is driven by a point frequency with a wide bandwidth.
[0106]
Note that the vibration force characteristics of the vibrator 6 differ depending on the Q value of mechanical resonance formed by the suspension and the magnetic circuit unit. FIG. 24 shows force frequency characteristics of linear suspensions having different Q values. IV is Q = 5, V is Q = 10, and VI is Q = 20. The characteristic shown in FIG. 20 is Q = 20. 25A to 25C show time waveforms of vibration force when an 8-point signal is applied to the vibrator 6 having different Q values. In FIG. 25, Q = 5 in FIG. 25A, Q = 10 in FIG. 25B, and Q = 20 in FIG. 25C. When Q is small, the frequency characteristic of the force characteristic becomes flatter, so the point frequency is small. Thus, for example, when Q = 5 or less, 4 points or 2 points has less fluctuation in the voltage level of the waveform of the addition signal, and a large vibration can be obtained. Further, when Q is 10 or more, the level at the resonance frequency is high and sharp, but if the point frequency is distributed to the low frequency range including the upper and lower bands of the resonance frequency with 8 or more point frequencies, for example, Q = 20. At Q = 30, there is a difference in vibration force in the extremely narrow band of the resonance frequency, but when the frequency is several Hz away from the upper and lower frequencies, the same vibration level is obtained in the frequency band higher or lower than that. When driven by a signal generated by synthesis, there is no significant difference in the vibration force. That is, in the case of a linear suspension, it is desirable to optimally select the number of point frequencies to be synthesized based on the resonance Q value. Although the Q value depends on the design of the vibrator 6, as a means for reducing Q, the magnetic circuit is strengthened to increase the electromagnetic braking resistance of the voice coil, or the suspension material has a large internal loss. Although it is effective to increase the mechanical resistance by using a damping material, in order to increase the electromagnetic braking resistance, the magnetic circuit becomes large and it is difficult to realize a small vibrator 6. Further, when the mechanical resistance is increased, the level of resonance is suppressed, and a large electric input is required to obtain a large vibration force, resulting in a vibrator 6 with reduced efficiency. In the non-linear suspension, even if the electromagnetic braking resistance is not large, the frequency range in which the vibration force is large is widened due to the jumping phenomenon of the suspension. Therefore, the vibrator 6 that is smaller than the linear suspension and can obtain a large vibration force can be realized. This signal is effective regardless of the linearity of the suspension.
[0107]
The vibration characteristics can be easily changed by changing the signal waveform. As a result, the ringing can be made with various vibrations as in the case where the current ringing tone uses various melodies. For example, it is possible to change the vibration mode according to the telephone partner.
[0108]
26A and 26B show the case where an 8-point signal with a 5 Hz interval is added and applied to the vibrator 6 using a non-linear suspension. FIG. 26A shows the voltage time waveform of the signal and FIG. 26B shows the time waveform of the vibration force. FIGS. 27A and 27B show the case where an 8-point signal with an interval of 4 Hz is applied to the same vibrator 6, FIG. 27A shows the voltage time waveform of the signal, and FIG. 27B shows the time waveform of the vibration force. In this example, the characteristics of the vibration force can be changed by changing the interval of the point frequencies. Thus, the vibration mode switching can be easily realized by the present invention. The vibration mode switching can be changed depending on the number of point frequencies, the phase of each signal, and the like.
[0109]
Moreover, although the time waveform of the input signal is shown as being continuous, it may be a signal that is intermittently repeated at a predetermined time interval. In this case, stationary and vibration are repeated, and the call by vibration becomes clearer in the human experience.
[0110]
(Embodiment 3)
A second embodiment of the electro-mechanical-acoustic converter 200 of the present invention will be described with reference to FIG. In the description, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. That is, the present embodiment is different from the first embodiment in that an acoustic signal generator 12 is provided along with the electric signal generator 7, and an electric signal from each is switched by the switch SW2 and applied to the vibrator 6. Is.
[0111]
The electric signal generating vibrator 7 is composed of a sweep frequency and a signal having a plurality of point frequencies that stably generate vibrations, and can also generate voice and music signals, but the circuit configuration is complicated. Therefore, when the vibration operation is performed, the signal from the electrical signal generation device 7 is turned on by the switch SW2, and the signal from the acoustic signal generation device 12 is turned on by the switch SW2 at the time of reproduction of music or voice acoustic signals. Is. As a result, the vibration and sound operations are separated, and the circuit configuration is simplified.
[0112]
The electric signal generator 7 may be a recording medium such as a semiconductor memory capable of recording / reproducing an arbitrary signal waveform, or may be a DSP (Digital signal processor).
[0113]
(Embodiment 4)
A third embodiment of the portable terminal device of the present invention will be described with reference to FIGS. In the description, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. FIG. 29 is a perspective view of a mobile phone 300 that is one of the mobile terminal devices on which the vibrator 6 described in the first embodiment is mounted. FIG. 30 is a block circuit diagram of a main part of a mobile phone 300 using the vibrator 6 of the first embodiment.
[0114]
According to FIG. 29, the vibrator 6 is attached to the outer case 13 of the mobile phone 300 main body. 30, 14 is an antenna, 15 is a received signal processing unit, 16 is an electric signal generating device, SW3 is a switch for switching the electric signal of the received signal processing unit 15 and the electric signal generating device 16 to the vibrator 6.
[0115]
Next, the operation will be described. The antenna 14 receives an incoming signal sent from a transmitter (not shown) of the mobile phone. This incoming signal includes a received signal that informs the incoming call and a received sound signal that is the voice of the sender. This incoming signal is subjected to signal processing by the received signal processing unit 15, and a signal K is first generated in response to the received signal for notifying the receiver of the incoming call. When the signal K is generated, the switch SW3 that is normally in the OFF state is turned ON by the reception signal processing unit 15 or the electrical signal generator 16. When the switch SW3 is connected to the electric signal generator 16, the frequency signal described in the first embodiment is generated, and the magnetic circuit portion supported by the nonlinear suspension of the vibrator 6 vibrates due to this signal. The vibration causes the mobile phone 300 to vibrate and operates as a vibrator that is called by vibration. Alternatively, when the signal generated from the electrical signal generator 16 is a ringing tone, the vibrator 6 operates as a speaker for sound reproduction. When the receiver knows the reception by vibration or ringing tone and makes the mobile phone ready for reception, the reception signal processing unit 15 is switched on by the signal K by switching the switch SW3 by the signal K. The signal from the reception signal processing unit 15 is a reception sound, and the vibrator 6 is installed at a distance from the receiver or the portable terminal, and operates as a loudspeaker for listening to the reception sound, for example.
[0116]
As described above, the mobile phone 300 of the above embodiment generates a sweep frequency or a point frequency in the vibrator 6 by the electric signal generator 16 and can efficiently extract a large amount of vibration that can be taken out from the vibrator 6. It can reduce the power consumption of the battery, which is a major problem with telephones.
[0117]
In the above example, the electrical signal generator 16 generates a ringing tone, but the signal from the reception signal processing unit 15 may generate a ringing tone. In this case, the reception signal processing unit 15 generates a ringing tone, a receiving tone, and further a loudspeaker speaker tone.
[0118]
(Embodiment 5)
A fourth embodiment of the portable terminal device of the present invention will be described with reference to FIG.
[0119]
FIG. 31 is a block circuit diagram of a main part of a mobile phone 400 using the vibrator 6 described in the first embodiment. Although not shown here, the vibrator 6 is attached to the mobile phone body as in the third embodiment. According to FIG. 31, 14 is an antenna, 17 is a received signal processing unit, 16 is an electric signal generating device, 18 is a signal synthesizing unit, switches SW4 and SW5 are a receiving signal processing unit 17 and a signal synthesizing unit 18, and an electric signal generating device. An electrical signal switch provided between the signal synthesizing means 18 and the signal synthesizing means 18, and SW 6 is an electrical signal switch provided between the signal synthesizing means 18 and the vibrator 6.
[0120]
Next, the operation will be described. The antenna 14 receives an incoming signal sent from a transmitter (not shown) of the mobile phone. This incoming signal includes a received signal that informs the incoming call and a received sound signal that is the voice of the sender. This incoming signal is signal-processed by the received signal processing unit 17, and first, signals K1, K2, and K3 are generated in response to the received signal for notifying the receiver of the incoming call. When the signals K1, K2, and K3 are generated, the switches SW4, SW5, and SW6 are controlled to select the ON / OFF operation.
[0121]
When the signal K1 is turned off, the signal K2 is turned on, and the signal K3 is turned on, the switch SW4 is turned off, the switch SW5 is turned on, and the switch SW6 is turned on, and the vibration signal from the electrical signal generator 16 is synthesized. Input to means 18. Since the signal from the reception signal processing unit 17 is in the OFF state, the signal synthesis unit 18 applies the vibration signal from the electric signal generator 16 to the vibrator 6.
[0122]
This signal causes the magnetic circuit portion supported by the nonlinear suspension of the vibrator 6 to vibrate, and this vibration vibrates the mobile phone and operates as a vibrator that is called by vibration. Similarly, when the signal K1 is ON, the signal K2 is OFF, and the signal K3 is ON, the switch SW4 is ON, the switch SW5 is OFF, and the switch SW6 is ON. Is input to the signal synthesis means 18. Since the signal from the electrical signal generator 16 is in the OFF state, the signal synthesis unit 18 applies the acoustic signal from the reception signal processing unit 17 to the vibrator 6. In this case, the vibrator 6 operates as a speaker for sound reproduction, and functions as a ringing tone, a receiver, or a loudspeaker. Further, when the signal K1 is turned on, the signal K2 is turned on, and the signal K3 is turned on, the switch SW4 is turned on, the switch SW5 is turned on, and the switch SW6 is turned on. Vibration signals from the electrical signal generator 16 are simultaneously input to the signal synthesis means 18. Therefore, the acoustic signal from the reception signal processing unit 17 and the vibration signal from the electric signal generator 16 are combined by the signal combining unit 18 and applied to the vibrator 6. Thereby, the vibrator 6 can notify, for example, an incoming call by both vibration and sound. Alternatively, even when a call from another person is received during a call reception, it is possible to know an incoming call from a third party by vibration. In this case, since the vibration does not interfere with the received sound, a portable terminal device having a combined operation of incoming and receiving can be realized without deteriorating the sound quality of the telephone.
[0123]
In the first to fifth embodiments, the vibrator 6 is an electrodynamic type using a magnetic force generated in a voice coil inserted in a magnetic field. However, a transducer type such as a piezoelectric type or an electromagnetic type may be used. A similar configuration is possible if the vibration force characteristics have similar non-linear characteristics.
[0124]
【The invention's effect】
As described above, the configuration of the electro-mechanical-acoustic converter according to the present invention realizes a large vibration force in a wide frequency band by using a nonlinear suspension for the vibrator. Even when a linear suspension is used, by inputting a signal obtained by adding and combining multiple point frequencies, large fluctuations in vibration force due to variations in the vibration characteristics of the vibrator can be eliminated, and the drive circuit can be simplified. As a result, a stable vibration force can always be obtained efficiently. As a result, application to a mobile phone or the like is possible, and power consumption of the mobile terminal device can be reduced, and further, space saving and weight reduction can be realized by simplifying the circuit.
[Brief description of the drawings]
FIG. 1 is a block circuit diagram of a main part of an electro-mechanical-acoustic converter according to Embodiment 1 of the present invention.
FIG. 2 is an exploded perspective view of a specific example of a vibrator as the main part.
FIG. 3A is a top view showing a state where a baffle of a vibrator which is the main part is removed.
FIG. 3B is a sectional side view of the vibrator with the baffle removed.
FIG. 4 is a diagram showing displacement-force characteristics of the vibrator suspension according to the first embodiment.
FIG. 5 is a diagram showing displacement-stiffness characteristics of the suspension
FIG. 6 is a diagram showing force frequency characteristics of the vibrator according to the first embodiment.
FIG. 7 is a diagram showing frequency characteristics of the same force
FIG. 8 is a diagram showing force frequency characteristics of a conventional vibrator using a linear suspension.
FIG. 9 is a diagram showing displacement-stiffness characteristics of the second nonlinear suspension according to the first embodiment.
FIG. 10 is a diagram illustrating a second force frequency characteristic of the vibrator according to the first embodiment.
FIG. 11 is a diagram showing force frequency characteristics and input frequency points of the vibrator according to the first embodiment.
FIG. 12 is a diagram showing force frequency characteristics of the vibrator according to the first embodiment.
13A is a diagram showing input-output characteristics when a single frequency is input in the electro-mechanical-acoustic converter according to Embodiment 1. FIG.
FIG. 13B is a diagram showing input-output characteristics when a single frequency is input in the electro-mechanical-acoustic converter according to Embodiment 1;
FIG. 13C is a diagram showing input-output characteristics when the single frequency is input in the electro-mechanical-acoustic converter according to Embodiment 1;
FIG. 13D is a diagram showing input-output characteristics when the single frequency is input in the electro-mechanical-acoustic converter according to Embodiment 1;
FIG. 14A is a diagram showing input-output characteristics when a synthetic frequency signal is input in the electro-mechanical-acoustic converter according to Embodiment 1;
14B is a diagram showing input-output characteristics when a synthetic frequency signal is input in the electro-mechanical-acoustic converter according to Embodiment 1. FIG.
FIG. 15 is a diagram showing fluctuations in force frequency characteristics of the vibrator according to the first embodiment.
FIG. 16A is a time waveform diagram of a composite signal obtained by adding a plurality of frequency signals in phase.
FIG. 16B is a diagram of a time waveform of vibration force characteristics obtained by the same signal.
FIG. 17A is a diagram of a time waveform of a combined signal obtained by adjusting and adding phases of a plurality of frequency signals in the electro-mechanical-acoustic converter according to Embodiment 1;
FIG. 17B is a diagram of a time waveform of vibration force characteristics obtained by the same signal in the electro-mechanical-acoustic converter according to Embodiment 1.
FIG. 18A is a time waveform diagram of vibration force characteristics when the force frequency characteristic of the vibrator changes to the low frequency side in the electro-mechanical-acoustic converter according to Embodiment 1;
FIG. 18B is a time waveform diagram of the vibration force characteristic when the force frequency characteristic of the vibrator changes to the high frequency side in the electro-mechanical-acoustic converter according to the first embodiment.
FIG. 19 is a plan view of the linear suspension according to the second embodiment.
FIG. 20 is a graph showing force frequency characteristics of a vibrator using the linear suspension according to the second embodiment.
FIG. 21A is a graph showing a time waveform of vibration force characteristics in the second embodiment;
FIG. 21B is a graph showing a time waveform of the vibration force characteristics in the second embodiment.
FIG. 22A is a graph showing a time waveform of vibration force characteristics in the second embodiment;
FIG. 22B is a graph showing a time waveform of vibration force characteristics in the second embodiment.
FIG. 23 is a block diagram of the electrical signal generator of the second embodiment.
FIG. 24 is a graph showing force frequency characteristics of linear suspensions having different Q values according to the second embodiment.
FIG. 25A is a graph showing a time waveform of vibration force characteristics in the second embodiment;
FIG. 25B is a graph showing a time waveform of vibration force characteristics in the second embodiment.
FIG. 25C is a graph showing a time waveform of vibration force characteristics in the second embodiment;
FIG. 26A is a graph showing a time waveform of vibration force characteristics in the second embodiment;
FIG. 26B is a graph showing a time waveform of the vibration force characteristics in the second embodiment.
FIG. 27A is a graph showing a time waveform of vibration force characteristics in the second embodiment;
FIG. 27B is a graph showing a time waveform of the vibration force characteristics in the second embodiment.
FIG. 28 is a block circuit diagram of the main part of the electro-mechanical-acoustic converter according to Embodiment 3 of the present invention.
FIG. 29 is a perspective view of a mobile phone according to a fourth embodiment on which the electro-mechanical-acoustic converter of the present invention is mounted.
30 is a block circuit diagram of a main part of the electro-mechanical-acoustic converter according to Embodiment 4. FIG.
FIG. 31 is a block circuit diagram of the main part of the electro-mechanical-acoustic converter according to the fifth embodiment.
FIG. 32 is a sectional view of the structure of a conventional vibrator.
FIG. 33 is a diagram showing force frequency characteristics of the vibrator
[Explanation of symbols]
6 Vibrator
7 Electric signal generator
8 Magnetic circuit section
9,10 Suspension
12 Electroacoustic signal generator
13 Mobile phone
14 Antenna
15 Received signal processor
18 Signal synthesis means

Claims

A drive circuit for driving a vibrator having a mechanical vibration system having a predetermined vibration force frequency characteristic,
The mechanical vibration system has different vibration force frequency characteristics in frequency increase and decrease in a predetermined frequency range,
The frequency range includes a low-frequency limit frequency representing the lowest frequency in the frequency range and a high-frequency limit frequency representing the highest frequency in the frequency range;
The drive circuit outputs a first signal having a frequency included in the frequency range and a second signal having a frequency lower than the low-frequency limit frequency to the vibrator,
The second signal is output to the first signal at the same time as the vibrator,
The vibrator may have a function of converting at least one in the electrical signal and the sound and vibration,
The vibrator includes a magnetic circuit unit and at least one suspension,
The drive circuit , wherein the suspension is a non-linear suspension .

The suspension, when expressed stiffness S in multidimensional function of the displacement X, X ² term is non-linear suspension having a value, the drive circuit of claim 1, wherein.

Driving circuit is an electric signal generator for generating an electrical sound signal of a frequency signal of the vibration or sound, claim 1 Symbol mounting of the drive circuit.

Wherein the first signal comprises a sweep signal whose frequency varies continuously, claim 1 Symbol mounting of the drive circuit.

Wherein the first signal includes a plurality of point frequency signals, according to claim 1 Symbol mounting of the drive circuit.

Wherein at least one of the first signal and the second signal includes a rising signal changing to a higher from more frequency is low, according to claim 1 Symbol mounting of the drive circuit.

The first signal includes a sweep signal whose frequency continuously changes,
The first signal has a first folding frequency from rising to falling and a second folding frequency from falling to rising;
The first folding frequency is lower than the high frequency limit frequency,
It said second folding frequency is higher than said low range limit frequency, claim 1 Symbol mounting of the drive circuit.

Wherein the first signal comprises at least one point frequency signal, according to claim 1 Symbol mounting of the drive circuit.

The drive circuit outputs a synthesized signal obtained by adding the first signal and the second signal to the vibrator, claim 1 Symbol mounting of the drive circuit.

The driving circuit outputs a composite signal of the first signal and the second signal by adding by changing the phase to said vibrator, claim 1 Symbol mounting of the drive circuit.

Wherein at least one of the first signal and the second signal includes a sine wave signal, according to claim 1 Symbol mounting of the drive circuit.

Wherein at least one of the first signal and the second signal includes a rectangular wave signal, according to claim 1 Symbol mounting of the drive circuit.

The drive circuit according to claim 9 , wherein the drive circuit includes a limiter that limits a peak of an output voltage of the combined signal.

The composite signal is a sine wave signal;
The synthesized signal is composed of two adjacent frequency signals as one set of signals, the first set is synthesized as a reverse phase, the second set is synthesized in the positive phase, and the first set and the second set of signals are further combined. The drive circuit according to claim 10 , wherein the drive circuit is a frequency signal configured by combining a plurality of combinations as one set.

A vibrator having a mechanical vibration system having a predetermined vibration force frequency characteristic;
A drive circuit for driving the vibrator,
The mechanical vibration system has different vibration force frequency characteristics in frequency increase and decrease in a predetermined frequency range,
The frequency range includes a low-frequency limit frequency representing the lowest frequency in the frequency range and a high-frequency limit frequency representing the highest frequency in the frequency range;
The drive circuit outputs a first signal having a frequency included in the frequency range and a second signal having a frequency lower than the low-frequency limit frequency to the vibrator,
The second signal is output to the first signal at the same time as the vibrator,
The vibrator includes a magnetic circuit unit and at least one suspension,
The suspension is an electromechanical acoustic transducer, which is a nonlinear suspension .

When the stiffness S is expressed by a multi-order function of the displacement X, the suspension ²² The electromechanical acoustic transducer according to claim 15, wherein the term is a nonlinear suspension having a value.

The drive circuit outputs a combined signal obtained by adding the first signal and the second signal to the vibrator,
The drive circuit, by changing at least one of the frequency and the frequency interval and the phase and the voltage level of the first signal and the second signal, selectively changing the combined signal, according to claim 15 Electromechanical acoustic transducer.

A vibrator having a mechanical vibration system having a predetermined vibration force frequency characteristic;
An antenna for receiving an incoming signal and a received signal;
Received signal processing means for processing the incoming signal and outputting an electrical signal to the vibrator;
A drive circuit for driving the vibrator,
The mechanical vibration system has different vibration force frequency characteristics in frequency increase and decrease in a predetermined frequency range,
The frequency range includes a low-frequency limit frequency representing the lowest frequency in the frequency range and a high-frequency limit frequency representing the highest frequency in the frequency range;
The drive circuit outputs a first signal having a frequency included in the frequency range and a second signal having a frequency lower than the low-frequency limit frequency to the vibrator,
The second signal is output to the first signal at the same time as the vibrator,
The vibrator includes a magnetic circuit unit and at least one suspension,
The mobile terminal device , wherein the suspension is a non-linear suspension .

When the stiffness S is expressed by a multi-order function of the displacement X, the suspension ²² The portable terminal device according to claim 18, wherein the term is a nonlinear suspension having a value.

19. The portable terminal device according to claim 18 , further comprising a switching unit that connects the vibrator to either the drive circuit or the received signal processing unit based on an output of the received signal processing unit.

19. The portable terminal device according to claim 18 , further comprising signal synthesis means for synthesizing the electrical signal output by the reception signal processing means and the output of the drive circuit.

A first switch provided between the received signal processing means and the signal combining means;
A second switch provided between the drive circuit and the signal synthesis means;
The portable terminal device according to claim 21 , further comprising a third switch provided between the signal synthesizing unit and the vibrator.

The drive circuit outputs a combined signal obtained by adding the first signal and the second signal to the vibrator,
The drive circuit, by changing at least one of the frequency and the frequency interval and the phase and the voltage level of the first signal and the second signal, selectively changing the combined signal, according to claim 18, wherein Mobile terminal device.

A drive circuit for driving a vibrator having a mechanical vibration system having a predetermined vibration force frequency characteristic,
  The mechanical vibration system has different vibration force frequency characteristics in frequency increase and decrease in a predetermined frequency range,
  The frequency range includes a low-frequency limit frequency representing the lowest frequency in the frequency range and a high-frequency limit frequency representing the highest frequency in the frequency range;
  The drive circuit outputs a first signal having a frequency included in the frequency range and a second signal having a frequency lower than the low-frequency limit frequency to the vibrator,
  The second signal is output to the vibrator at the same time as or before the first signal,
  The vibrator has a function of converting an electrical signal into at least one of sound and vibration,
  The vibrator includes a magnetic circuit unit and at least one suspension,
  When the stiffness S is expressed by a multi-order function of the displacement X, the suspension ²² A drive circuit, wherein the term is a nonlinear suspension having a value.