JP4136584B2 - Coordinate input device, coordinate value output method and program - Google Patents

Description

【００４７】
である。これから音波発生源４３の位置のｘ座標は、次式により求められる。
【００４８】
【数２】

【００４９】
同様にしてｙ座標とｚ座標は次式により求められる。
【００５０】
【数３】

【００５１】
このような演算をマイクロコンピュータ３０１が行なうことにより、座標入力ペン４の音波発生源４３の位置の３次元座標（ｘ，ｙ，ｚ）を算出することができる。
【００５２】
なお、上記（３）〜（５）式から分かるように、例えば距離Ｌa，Ｌb，Ｌｃが分かれば、つまり３個の検出センサと音波発生源４３の距離を測定できれば音波発生源４３の位置座標を算出できる。本実施形態では、検出センサとして３ａ〜３ｄの４個を用いているので、例えば、音波発生源４３からの距離が最も遠いセンサの情報を使わず（このセンサでは、距離が最も遠いために出力信号レベルが最も小さくなっている）、残り３個の距離情報のみで座標を算出することで、信頼性の高い座標算出を可能としている。また、この距離が最も遠いセンサの情報を活用することで、出力された座標値の信頼性が高いものか判定することも可能である。具体的方法としては、例えば、距離情報Ｌa、Ｌb、Ｌcで算出された座標値と、距離情報Ｌb、Ｌc、Ｌdで算出された座標値は同一の値を出力するはずであり（距離情報の組み合わせを変更して演算する）、両者が一致しない場合には、いずれかの距離情報が不正、つまり誤検出したことになるので、その場合には、座標値を出力しない、と言った信頼性を向上させる構成も実施可能となる。
【００５３】
なお、以上に説明した構成は、単に座標入力ペン４の音波発生源４３の位置の３次元座標の入力だけを行なうものであるが、特許文献１に記載されたものと同様に、音波発生源４３を２つ座標入力ペン４の長手方向に沿って並ぶように設け、その２つの位置のそれぞれの３次元座標を検出し、それからその２つの位置を結ぶ直線とディスプレイ６の表示画面との交点の位置の座標を導出するようにすれば、レーザーポインタと同様に表示画面の所望の位置を直線的に指示するポインタとして用いることができる。
【００５４】
ところで、本実施形態では、前述した発明の課題を解決するために、検出される一連の３次元座標の内のｘ座標とｙ座標を平均化する演算処理（以下、平均化処理という）をマイクロコンピュータ３０１（のＣＰＵ３０１ａ）が行なう。
【００５５】
この平均化処理は、周期的に逐次検出される一連のｘ座標値とｙ座標値の算術平均を求めて平均化する処理であり、その際に検出されるｚ座標値が大きくなるほど１回に平均化する座標値のサンプル数（以下、平均化サンプル数という）を大きくする。
【００５６】
この平均化処理の詳細を図７により以下に説明する。図７は平均化処理の演算処理手順を示すフローチャートであり、これに対応した演算処理プログラムがマイクロコンピュータ３０１のＲＯＭ３０１ｂに格納され、ＣＰＵ３０１ａにより実行される。
【００５７】
図７の処理では、まずステップＳ１０１において、後述のように逐次検出されて記憶されるｘ，ｙ，ｚ座標値のそれぞれのサンプル数を示す整数ｎを０に初期化し、その後、座標入力ペン４の音波発生源４３の位置の座標が検出されるまで、待機する。
【００５８】
ここで、あるタイミングで座標が検出されると、ステップＳ１０２においてサンプル数ｎを『１』インクリメントし（この場合、最初でｎ＝１になる）、その後、ステップＳ１０３で検出した座標値（Ｘ,Ｙ,Ｚ）をｎ番目のサンプルの座標値（Ｘn,Ｙn,Ｚn）としてＲＡＭ３０１ｃに記憶する。
【００５９】
続いて、ステップＳ１０４でサンプル数ｎ＝１か否か判定し、ｎ＝１の場合はステップＳ１０５で検出された座標値の内のＺ座標値に基づいて平均化サンプル数Ｋendを設定する。その設定方法は、上述のようにＺ座標値が大きくなる程（言い換えれば、座標入力ペン４がディスプレイ６の表示画面（Ｚ=０）からより離れた所に位置する程）、平均化サンプル数Ｋendの値をより大きく設定する様にし、その増大方法は、例えばＺ座標値の増大に応じて比例的あるいは指数関数的に増大させても良い。
【００６０】
ステップＳ１０５の後、及びステップＳ１０４でサンプル数ｎ＝１でなかった場合、ステップＳ１０６に進み、サンプル数ｎの値が平均化サンプル数Ｋendの値と一致しているか判定し、一致しない場合にはステップＳ１０８で座標が連続的に検出されているか判定し、連続的に検出されている場合には、ステップＳ１０２に戻りステップＳ１０２〜Ｓ１０６，Ｓ１０８の処理を繰り返す。これにより、連続的な座標検出が中断されない限り、ステップＳ１０６でサンプル数ｎの値が平均化サンプル数Ｋendの値と一致するまで逐次検出された座標が記憶される。
【００６１】
そして、ステップＳ１０６でサンプル数ｎの値が平均化サンプル数Ｋendの値と一致した場合には、ステップＳ１０７で一連の動作で検出され記憶されたＸ座標値とＹ座標値（それぞれ平均化サンプル数Ｋend個の座標値が存在している）の算術平均（相加平均）値、すなわち、それぞれの座標値の合計値を平均化サンプル数Ｋendで除した商の座標値Ｘave,Ｙaveを算出し、Ｉ／Ｏポート３０７を介してディスプレイ駆動回路７や他の外部機器などに出力する。ここでＺ座標値の平均値Ｚaveも算出して出力するようにしてもよい。例えば座標入力ペン４に音波発生源４３を２つ設けてポインタとして構成する場合にはＸ，Ｙ，Ｚの座標値の全ての平均化処理を行なう。また、用途に応じて、Ｘ，Ｙ，Ｚ座標値のいずれか１つのみの平均値を算出して出力することもあり得る。
【００６２】
このようにして平均値を出力した後、一連の処理を終了（ステップＳ１０９）して、ステップＳ１０１のサンプル数ｎの初期化、待機状態に戻る。
【００６３】
一方、ステップＳ１０８で連続的に座標検出が行なわれていなかった場合、すなわち連続検出状態が中断した場合には、整数ｎが平均化サンプル数Ｋendの値に達していなくても、ステップＳ１０９に進んで処理を終了する。これは連続的に座標検出が行われている状態であればこそ、平均化処理による座標値が有効となるためである。
【００６４】
なお、ここでの座標の連続検出の判定方法について説明しておく。本座標入力装置が例えば座標検出を１００回／秒の座標サンプリングレートで行えるものとすれば、１０msecの周期毎に座標が検出される。この周期を計測することで、連続的に座標検出が行われているかを判定することができる。具体的には、例えば、制御信号検出回路２１１が検出する光信号のスタート信号の発生タイミングを監視（この場合、サンプリングレートを１００回／秒とすれば、０.０１秒毎にスタート信号が発生する）する事によって、連続検出の状態にあるかどうかを判定する。また、その他の方法として、直接に図３の音波検出信号１０２の到達間隔を監視する。この場合は、座標入力ペン４の移動に伴ってペン４と各検出センサ３ａ〜３ｄの距離が絶えず変化するので、サンプリングレートに基づく時間（サンプリングレートを１００回／秒とすれば０.０１秒）に対して距離変化に伴なう音波の伝達時間の差が増減される。従って約０.０１秒程度の周期（理論的には０〜０.０２秒の範囲内に必ず信号が受信される）と言う表現になり、実用上０.０１秒以内におけるペン４の最大移動量を考慮し、例えば０.０１５秒以内に信号が受信できたときには連続して座標検出が行われていると判定する。
【００６５】
以上のように、検出されたｚ座標値が大きくなるほど、すなわち座標入力ペン４と検出センサ３ａ〜３ｄとの距離が大きくなるほど大きな平均化サンプル数でｘ，ｙないしｚ座標値を平均化して出力することにより、上記距離が大きくなるほど座標検出分解能が低下することを補償することができる。つまり、座標検出分解能の低下による検出座標値のばらつきを検出座標値の平均化によって消去することができ、それにより実質的に座標検出分解能を向上させることができる。そして、ディスプレイ６の表示画面から離れた位置から座標入力ペン４の位置のＸ，Ｙ座標の入力により表示画面上のカーソルの位置を制御する場合に距離の増大に伴うカーソルの揺らぎを抑えることができる。
【００６６】
また、座標入力ペン４に音波発生源４３を２つ設けてポインタとして構成した場合、前述のように、操作者が表示画面から離れた位置からペン４で表示画面上の所望の位置を指示する際に、操作者がペン４を保持する手元の振れによる表示画面上の指示点（２つの音波発生源４３を結ぶ直線と表示画面の交点）の揺らぎを平均化処理により抑制することができる。つまり、ペン４を保持した手元の振れによる２つの音波発生源４３の位置の座標値の変動を、その平均化により抑制することができ、それにより、前記座標値から導出される表示画面上の指示点（上記の交点）の座標値の変動、すなわち指示点の揺らぎを抑制することができる。こうして、表示画面上の指示点の揺らぎを抑制して、指示点に表示されるカーソルなどの揺らぎを抑制することができ、表示画面を見ている人にとって見易い環境を提供することができる。
【００６７】
ただし、上記の平均化処理により、座標サンプリングレートが実質的に低下する。例えば、図７のステップＳ１０５で平均化サンプル数Ｋendの値がＫend＝１０にセットされたと仮定すると、例えば座標サンプリングレート１００回/秒の性能を有する座標入力装置の場合、この平均化処理により外部への座標値の出力は秒あたり１０回に低下することになる。しかし、これは以下の理由により問題ない。
【００６８】
操作者にとってみれば、Ｚ＝０、つまりディスプレイ６の表示画面上では、座標入力ペン４によって文字、図形等の筆記入力を行い、その筆跡を表示する事で『ホワイトボード』のように情報を記録できることが重要であり、文字、図形としてその筆跡を忠実に再現するために十分な座標サンプリングレートが確保されていなければならない。
【００６９】
しかし、画面から離れるに従って、その機能は重要でなくなり、離れた場所で特定の位置を『指示できる』、或いは特定の文章に『アンダーラインを引く』、さらには特定の領域を『囲む（選択する）』と言った大雑把な動作の機能が重要になる。つまり、画面から離れるに従って座標サンプリングレートが実質的に低下しても、上記の『大雑把な動作』の実現は可能であり、問題ない。
【００７０】
また、本実施形態では、座標算出に関して、時間遅れが発生する。つまり、座標入力した時点から平均化サンプル数Ｋend分の座標算出が行われなければ、外部への座標出力を行わない仕様なので、例えば、座標入力装置のサンプリングレートを１００点/秒、平均化サンプル数Ｋendを１０回とすれば、１０msecの時間遅れが生じる。しかし、検討の結果、その程度の時間遅れでは、人間の感覚（座標入力したのに、出力されない、或いは遅れていると感じる間隔）として問題なく操作できることが確認されている。平均化サンプル数Ｋendがそれ以上の値になると、人間は遅れていると感じ始めるが、そのような平均化サンプル数に設定されるのは、音波発生源４３と検出センサ３ａ〜３ｄの距離が比較的大きな距離、言い換えれば、ディスプレイ６の表示画面から十分に離れた距離となっているので、その時の使用目的（細かい字や図形を入力するのでなくて、指し示す等の大雑把な動作）を鑑みれば、実用上問題無い。これは、次に述べる第２の実施形態、及び後述する第３の実施形態についても同様に言えることである。
【００７１】
［第２の実施形態］
上述した第１の実施形態の平均化処理では座標サンプリングレートが実質的に低下する。これに対処して座標サンプリングレートが実質的に低下しないようにして平均化処理を行なう第２の実施形態を図８により説明する。なお、第２の実施形態の装置に関して平均化処理の方法以外は第１の実施形態と共通とする。
【００７２】
図８は第２の実施形態における平均化処理の演算処理手順を示すフローチャートであり、これに対応した演算処理プログラムがマイクロコンピュータ３０１のＲＯＭ３０１ｂに格納され、ＣＰＵ３０１ａにより実行される。
【００７３】
図８の処理手順においてステップＳ１０１〜Ｓ１０９は第１の実施形態の図７のステップＳ１０１〜Ｓ１０９と共通であり、新たに付加されたステップＳ１１０だけ異なる。以下、図７の処理と共通の部分の説明は省略し、異なる部分のみ説明する。
【００７４】
図７の処理では、ステップＳ１０７においてそれまでの動作で検出され記憶された平均化サンプル数Ｋend個のＸ座標値とＹ座標値ないしＺ座標値の算術平均値Ｘave,ＹaveないしＺaveを算出して外部に出力した後、処理を終了し（ステップＳ１０９）、ステップＳ１０１へ戻ったのに対し、図８の処理ではステップＳ１０７の後にステップＳ１１０に進む。
【００７５】
ステップＳ１１０では、それまでの動作でＲＡＭ３０１ｃに記憶されている平均化サンプル数Ｋend個ずつのＸ，Ｙ，Ｚ座標値のそれぞれについて、最初の（最も古い）サンプルＸ1，Ｙ1，Ｚ1を消去した上で、残るサンプルＸnをＸn-1、ＹnをＹn-1、ＺnをＺn-1として再記憶する。例えば平均化サンプル数Ｋendが３だとするとＸ2をＸ1、Ｘ3をＸ2として再記憶する。またサンプル数ｎを「１」デクリメントする。
【００７６】
ステップＳ１１０の後はステップＳ１０８に進んで座標が連続的に検出されているか否か確認し、連続的に検出されていたらステップＳ１０２に戻り、ステップＳ１０２以下の処理を繰り返す。
【００７７】
また、ステップＳ１０８で座標が連続的に検出されていなかった場合、つまり座標の連続入力動作が終了した場合、記憶している座標値及び平均化サンプル数Ｋendなどの情報を全てリセットして処理を終了し（ステップＳ１０９）、ステップＳ１０１に戻る。
【００７８】
このような本実施形態の平均化処理によれば、座標検出が連続的になされている限り、検出される座標のサンプル数が最初に平均化サンプル数Ｋendに達した以後は１回の座標の検出毎に、座標の平均化、平均値の出力がなされ、移動平均の出力がなされる。従って、座標入力装置の本来の座標のサンプリングレートが例えば１００回／秒なら１００回／秒というようにそのままに維持される。
【００７９】
本実施形態の構成を採用したサンプリングレート１００回/秒の座標入力装置を用いた実験の結果、Ｚ＝０において（表示画面上の入力であって、文字、図形を入力するために高速のサンプリングレートが要求される状態）も平均化サンプル数１０回以下であれば、違和感無く的確な文字入力が行え、この観点で、座標入力装置の本来の座標検出分解能が比較的悪い場合であっても、本実施形態の構成を採用することで、座標検出分解能を向上できることがわかる。また、第１の実施形態に比べて表示画面から離れた所からでも高サンプリングレートで座標入力を行なうことができる。
【００８０】
以上説明した第１と第２の実施形態では、検出座標値の平均化処理を座標入力装置の内部で実行するものとしたが、座標入力装置が検出した座標値を受け取るホストコンピュータなどにおいて平均化処理を行なうものとしてもよい。
【００８１】
また、座標の連続検出を判定する方法として、座標入力装置のサンプリングレートに基づいて座標出力タイミングを監視して判定する方法の他に、例えば所定時間を設定して、その時間と座標出力タイミングを比較して判定しても良い。
【００８２】
また、第１と第２の実施形態では、検出したｘ，ｙ，ｚ座標値の内のｚ座標値という１軸座標値に基づき平均化サンプル数Ｋendを決定していたが、検出したｘ，ｙ，ｚ座標値の全てに基づいて平均化サンプル数を決定する方法もある。例えば検出したｘ，ｙ，ｚ座標値により、その座標値の位置（音波発生源４３の位置）からディスプレイ６の表示画面の中心である座標系の原点Ｏまでの距離を算出し、その距離に基づき平均化サンプル数を決定するようにしてもよい。また、検出したｘ，ｙ，ｚ座標値の内の２軸の座標値に基づいて平均化サンプル数Ｋendを決定することも考えられる。
【００８３】
また、従来知られているように、座標入力装置によって相対的に位置座標を設定し表示画面上のカーソルの位置を制御する仕様にあっては、座標入力ペン４によって指示された位置の絶対座標値とカーソルの表示位置は異なっている（相対的にずれている）ので、カーソルの表示位置を絶対位置としてまず算出し、そのカーソルの絶対位置と座標入力ペン４の絶対位置との距離を算出して、その距離に応じて平均化サンプル数を決定するようにしてもよい。
【００８４】
[第３の実施形態]
次に、本発明の第３の実施形態を図９〜図１４により説明する。なお、本実施形態の座標入力装置のハードウェアの構成及び座標検出の基本的な動作は先述した第１と第２の実施形態と共通とし、共通部分の説明は省略し、異なる点のみ説明する。
【００８５】
本実施形態では、第１と第２の実施形態では説明しなかった座標入力ペン４のペンダウンとペンアップの動作モードの切り換え、及び絶対座標と相対座標の出力モードの切り換えを図９の表図に示すように、座標入力ペン４のペン先スイッチ４１、ペンサイドスイッチ４２ａ，４２ｂの操作、及び検出したｘ，ｙ，ｚ座標値に応じて行なう。
【００８６】
まず、ペンダウンとペンアップの動作モードの切り換えについて説明する。ディスプレイ６の表示画面上において、ペンダウン状態の座標入力により文字や図形の筆記入力が行なわれ、ペンアップ状態の座標入力によりカーソルの移動やアイコンのクリックなどが行なわれるものとする。その切り換えは、座標入力ペン４のペン先スイッチ４１、ペンサイドスイッチ４２ａ，４２ｂの操作に応じて図１０のフローチャートに示す処理手順で以下のように行なわれる。なお、以下では「スイッチ」を「ＳＷ」と略す。
【００８７】
図１０の処理手順では、まず処理のスタート（ステップＳ４０１）後、操作者が座標入力ペン４を握って表示画面（座標入力面）を押圧することで、ペン先ＳＷ４１がオンしたら（ステップＳ４０２）、駆動回路４５の制御回路はペンダウン状態と判定し、音波発生源４３を所定周期で駆動し、音波が空中に放射されるようにすると共に、ペンダウン状態であることを演算制御回路１に通知する（ステップＳ４０６）。
【００８８】
その通知方法としては、例えば、ペンダウン状態の情報を発光手段４４から放射される光信号としてのスタート信号に重畳させて送信し、制御信号検出回路２１１で検波して検出できるようにする。また、音波発生源４３から放射する音波の周波数を変更し、演算制御回路１側でそれを検波することで、ペンアップ／ペンダウンを判定することも可能である。
【００８９】
ペンダウン状態で検出されたｘ，ｙ座標値が表示領域（表示画面の領域）内の座標値（図６においてｘ＜±Disp＿X、ｙ＜±Disp＿Yの範囲）であれば、演算制御回路１のマイクロコンピュータ３０１のＣＰＵ３０１ａは、その座標値を出力する（図９参照）。これにより通常の紙と鉛筆の様な関係で、座標入力ペン４の移動に伴なう軌跡が表示画面上に出力される事になる。
【００９０】
一方、ペン先ＳＷ４１がオンしているのに、検出されたｘ，ｙ座標値が表示領域外である時には、例えば操作者が筆記入力と無関係に無意識のうちにペン先ＳＷ４１を動作させてしまっている状態が想定されるので、この場合には、座標出力を禁止する。同様にペン先ＳＷ４１がオンしている状態は、座標入力ペン４により表示画面（座標入力面）を押圧する状態であるから、この時検出されるＺ軸座標値は、ほぼ『０』であるはずであり、『０』とならない場合には、やはり操作者による誤操作が想定されるので、この場合も座標出力を禁止する（図９参照）。
【００９１】
一方、ペン先ＳＷ４１がオフ状態の場合は、操作者により座標入力面を押圧する事で筆記動作している状態にはなっていない。しかしながら、表示画面の近傍あるいは離れた位置で、さらには表示画面（表示領域）の外側で、例えば表示されているカーソルを移動したり、アイコンをダブルクリック等して所望の画面操作ができることは非常に利点が大きい。
【００９２】
そのため、ステップＳ４０３〜Ｓ４０５でペンサイドＳＷ４２ａ，４２ｂのどちらか一方のみがオンされたら、駆動回路４５の制御回路はペンアップ状態と判定し、音波発生源４３を駆動して音波を発生させ、カーソルの移動などを可能にするとともに、ペンアップ状態であることを演算制御回路１に通知する（ステップＳ４０７）。
【００９３】
また、ステップＳ４０３〜Ｓ４０５でペンサイドＳＷ４２ａ，４２ｂの両方がオンされたら、駆動回路４５の制御回路は、ペン先ＳＷ４１がオンしていなくてもペンダウン状態と判定し、音波発生源４３を駆動して音波を発生させるとともに、ペンダウン状態であることを演算制御回路１に通知する（ステップＳ４０６）。
【００９４】
上述のように、ペンサイドＳＷ４２ａ，４２ｂを操作することで、ディスプレイ６の表示画面から離れた位置で座標を入力し、カーソルを移動（ペンアップ状態）したり、あるいは筆記（ペンダウン状態）したりできるが、この様な場合（ペン４が直接ディスプレイ６の表示画面に接触しておらず、ペン先ＳＷ４１がオンしていない状態）において、ディスプレイ６の表示画面上、あるいは表示画面の近傍で座標入力動作させる場合と、表示画面から比較的離れた位置、或いは表示領域の外側で座標入力動作をさせる場合とでは操作上、要求される仕様が異なる。
【００９５】
まず、前者の場合、座標入力ペン４を移動することで、例えば表示されているカーソルを直感的に、しかもダイレクトに所望の位置に正確に移動することが要求される。しかし後者の場合においては、例えば表示されているカーソルを所望の位置に移動させるためには、座標入力ペンの移動に応じて、カーソルを相対的に移動させることが要求される。つまり操作者が、大型のディスプレイを使ってプレゼンテーションをしようとする場合、直接画面をタッチ（座標入力）することで、表示情報を制御したり、情報（文字、図形）等を筆記することができる（紙と鉛筆の関係）手段であるとともに、単に情報を指し示す場合に有っては、操作者がその場に行って指し示すのではなく、離れた場所で、言い換えれば聞き手側からみて表示されている情報が操作者によって隠されることが無い状態で、所望の画面制御や情報の追加ができるのが好ましい。さらには、この種の大型の入出力一体のシステムを考慮して大勢の参加者を想定した打ち合わせなどを考えれば、上述したような操作者が直接画面をタッチしたりすることでパソコンを制御するばかりでなく、例えば画面を見ながら発表内容を聞いている会議参加者が、質問、或いは反論のための証拠資料を表示したりすることができるように、画面から離れた位置においても、画面を操作したり、必要に応じてネットワークより情報を引き出せるような構成になるのが好ましい形態であると言える。
【００９６】
そこで本実施形態では、検出された座標値（ｘ，ｙ，ｚ）に応じて、図９の表に示す出力座標値として絶対座標値を出力する出力モード１と、相対座標値（後述する差分）を出力する出力モード２との座標出力モードの切り換えを行なうとともに、先述した発明の課題を解決するために、第２の実施形態と同様の検出座標値の平均（移動平均）化処理を行なう。
【００９７】
この座標出力モードの切り換え及び平均化処理の詳細を図１１により以下に説明する。図１１は、その処理手順を示すフローチャートであり、これに対応した処理プログラムがマイクロコンピュータ３０１のＲＯＭ３０１ｂに格納され、ＣＰＵ３０１ａにより実行される。
【００９８】
図１１の処理では、まず処理を開始するステップＳ５０１において、後述のように逐次検出されて記憶されるｘ，ｙ，ｚ座標値のそれぞれのサンプル数を示す整数ｎを０に初期化する。
【００９９】
次に、ステップＳ５０２で座標演算に必要な有効な音波検出信号とスタート信号が各検出センサ３ａ〜３ｄと制御信号検出回路２１１で検出されたか否か判定し、有効な信号が検出された場合（座標算出を行なえる場合）には、ステップＳ５０３で整数ｎを『１』インクリメントする（最初の場合ｎ＝１となる）とともに、上記の有効な音波検出信号から先述のように各検出センサ３ａ〜３ｄと音波発生源４３の距離のそれぞれを計測する。
【０１００】
次に、ステップＳ５０４で整数ｎが１か否か判定し、１だったらステップＳ５０５においてステップＳ５０３で計測した各検出センサ３ａ〜３ｄと音波発生源４３の距離の内で音波発生源４３の位置座標の算出に用いる３つの距離情報（例えば４つの距離の内で最長の距離情報は算出に使用しない）に基づいて、前述した平均化処理における平均化サンプル数（平均化する座標値のサンプル数）Ｋendを設定する。その設定の方法は、例えば座標算出に用いる有効な３つの距離情報の中で、最も長い距離情報に基づき行われ、その値がより大きい程（言い換えれば、座標入力ペン４と検出センサの距離が大きい程）、平均化サンプル数Ｋendの値をより大きく設定する。その設定では、例えば距離値に応じて比例的に、或いは指数関数的に平均化サンプル数Ｋendの値を増大させる。
【０１０１】
次に、ステップＳ５０６で上記有効な３つの距離情報を用いて音波発生源４３の位置座標値（Ｘ,Ｙ,Ｚ）を算出し、サンプル数ｎ番目の座標値（Ｘn,Ｙn,Ｚn）としてＲＡＭ３０１ｃに記憶する。
【０１０２】
次に、ステップＳ５０７で整数ｎが１か否か判定し、１だったら、その直前のステップＳ５０６で算出し、記憶したサンプル数ｎ＝１番目の座標値（Ｘ1,Ｙ1,Ｚ1)を、以下に述べる座標出力モードの決定と差分値の算出に用いるために、改めて別にＲＡＭ３０１ｃに記憶する（ステップＳ５０８）。そして、ステップＳ５０９、Ｓ５１０でその座標値により座標出力モードを決定する。
【０１０３】
ここで、先述した図６のように座標入力装置の座標系を定義し、ディスプレイ６の表示画面をＸＹ平面（Ｚ=０）、その垂直方向をＺ軸として、ステップＳ５０９では、記憶したＺ軸の座標値Ｚ1が所定値（例えば距離１ｍなら１ｍに対応する値）より小さいか比較する。そして所定値より小さければ、さらにステップＳ５１０において記憶したＸ軸座標値Ｘ1、Ｙ軸座標値Ｙ1がディスプレイ６の表示領域（表示画面の領域）内の座標値（図６においてｘ＜±Disp＿X、ｙ＜±Disp＿Yの範囲内）であるかを判定し、表示領域内であるときは、座標出力モードを『出力モード１』にセットする。
【０１０４】
またステップＳ５０９で座標値Ｚ1が所定値以上である場合、或いはステップＳ５１０で座標値Ｘ1，Ｙ1が表示領域外の座標値であるときは、座標出力モードを『出力モード２』にセットする。
【０１０５】
なお図１１のフローチャートには、先に図９を用いて説明した動作モードを設定する方法の全てを示していないが、例えば座標入力ペン４のペン先ＳＷ４１の動作（オン、オフ）情報をスタート信号である光信号に重畳させ、制御信号検出回路２１１で制御信号として復調して検出すれば、ペン先ＳＷ４１の動作情報を用いて、座標算出の信頼性を増すことが可能となる。つまりペン先ＳＷ４１がオンした状態は、座標入力面であるところの表示画面を押圧してペン先ＳＷ４１がオンするのが通常であり、ペン先ＳＷ４１がオンしているにも関わらず、Ｚ軸の検出値がＺ=０とならない場合には、やはり何らかの誤操作によって座標入力が行われたものとして、検出した座標値の出力を中止することが可能となり、誤動作防止と言う観点で、より信頼性の高い構成が得られる（図９参照）。
【０１０６】
『出力モード１』の状態は、操作者がディスプレイ６の表示画面に比較的近いところで、しかもディスプレイ６の表示領域内で座標入力ペン４を操作している状態で、座標入力ペン４の移動動作に伴ない、ディスプレイ６に表示されているカーソルを移動したり、文字、図形等の情報を筆記したりして、表示情報を制御している状態となる。
【０１０７】
一方、『出力モード２』の状態は、例えば操作者は表示画面近傍において表示領域外（例えばディスプレイ６の横）にあって、聞き手に対して表示情報をさえぎることなく、表示内容を制御しながらプレゼンテーションしている状態、或いはディスプレイ６より離れた位置にあって、リモート操作で表示内容を制御している状況が想定できるので、座標入力ペン４の動作によりカーソルを相対的に移動できるように構成する。この『相対的』にカーソルを移動する方法について説明すれば、検出された座標値の少なくともＸ軸、Ｙ軸の各々の値を先にメモリした座標値（Ｘ1,Ｙ1）との差分値として演算する様に構成する。つまり、検出された座標値は、『出力モード１』の場合は、
検出座標値（Ｘn,Ｙn,Ｚn） → 記憶座標値（Ｘn,Ｙn,Ｚn） とし、
『出力モード２』の場合は、
検出座標値（Ｘn,Ｙn,Ｚn） → 記憶座標値（Ｘn-Ｘ1,Ｙn-Ｙ1,Ｚn-Ｚ1）
として処理される。
【０１０８】
次に、ステップＳ５１３において、整数ｎの値がステップＳ５０５で設定された平均化サンプル数Ｋendの値と一致しているかを判定し、一致していなければステップＳ５１６で座標検出が連続的になされているかを第１の実施形態の図７のステップＳ１０８で説明したのと全く同様にして判定する。そして座標検出が連続的になされていたらステップＳ５０３に戻り、座標検出が連続的になされている限り、ステップＳ５１３で整数ｎが平均化サンプル数Ｋendに達するまで、ステップＳ５０３〜Ｓ５１３，Ｓ５１６の処理を繰り返す。この繰り返しにより、逐次、座標値（出力モード１では絶対座標値、出力モード２では差分値）が算出され、ＲＡＭ３０１ｃに記憶される。
【０１０９】
そして、整数ｎが平均化サンプル数Ｋendに一致した場合には、ステップＳ５１４において、それまでの一連の動作で検出され記憶された平均化サンプル数Ｋend個ずつの座標値（出力モード１では絶対座標値、出力モード２では差分値）の算術平均値を算出し、Ｘ軸座標、Ｙ軸座標の値を外部機器等へ出力する（無論、Ｚ軸座標の平均値を外部機器等へ出力する仕様であってもかまわないし、用途に応じては、Ｘ軸座標またはＹ軸座標のみの出力形態もあり得る）。なお、ここで出力される座標値が『出力モード１』による絶対座標値か或いは『出力モード２』による差分値かを示す情報を座標値と共に出力するようにしてもよい。
【０１１０】
次に、ステップＳ５１５において、それまでの動作で記憶されている平均化サンプル数Ｋend個ずつのＸ，Ｙ，Ｚ座標値（出力モード１では絶対座標値、出力モード２では差分値）のそれぞれについて、最初の（最も古い）サンプルＸ1，Ｙ1，Ｚ1を消去した上で、残るサンプルＸnをＸn-1、ＹnをＹn-1、ＺnをＺn-1とシフトして再記憶する。例えば平均化サンプル数Ｋendが３だとするとＸ2をＸ1、Ｘ3をＸ2として再記憶する。またサンプル数ｎを「１」デクリメントする。
【０１１１】
その後、ステップＳ５１６に進み、先述のように座標が連続的に検出されているか否か確認し、連続的に検出されていたらステップＳ５０３に戻り、ステップＳ５０３以下の処理を繰り返す。
【０１１２】
一方、ステップＳ５１６において、座標検出が連続的に行なわれなかった場合、つまり座標の連続入力動作が終了した場合、記憶している座標値及び平均化サンプル数Ｋendなどの情報を全てリセットして処理を終了し、その後、ステップＳ５０１へ戻り整数ｎを初期化し、ステップＳ５０２で有効信号の検出を待つ待機状態となる。
【０１１３】
以上のようにして、本実施形態では、検出座標値に基づいて座標出力モードを切り替えるとともに、検出座標値の平均化処理を行なう。平均化処理により第１と第２の実施形態と同様の効果が得られる。すなわち、座標検出のための測定距離の増大に伴う座標検出分解能の低下を補償することができ、表示画面から離れた位置から座標入力ペン４でカーソルの位置を制御する場合に距離の増大に伴うカーソルの揺らぎを抑えることができる。
【０１１４】
ところで、ステップＳ５０９において、座標値Ｚ1が予め設定された所定値より大きい場合について考えてみる。この状態は座標入力ペン４が座標入力面であるところのディスプレイ６の表示画面からＺ軸方向に離れた位置にあることを意味する。つまりプレゼンテーションを行っている操作者がディスプレイ６から離れた位置にいるか、もしくはプレゼンテーションを聞いている聞き手によって座標入力が行われたものと想定できる。つまり、遠隔操作によって、表示情報を制御したり、文字、図形等の追記を行おうとしている状態であると言える。
【０１１５】
このディスプレイ６の表示画面から離れた状態について考察してみると、比較的離れた距離が小さい場合（近接入力）、表示画面と座標入力ペン４のＺ軸方向の距離は、比較的小さな値であり、座標入力ペン４を移動することで、例えば表示されているカーソルを直感的に、しかもダイレクトに所望の位置に移動することが可能である。もちろん、所望の位置に対するカーソルの位置ずれは、直接に表示画面に入力する場合（ペン先ＳＷ４１がオン状態）に比べ大きくなるが、十分実用の範囲と言うことができる。
【０１１６】
しかしながら、ディスプレイ６の表示画面との距離が大きくなる（Ｚ座標値が大きくなる）につれて、所望の位置に対するカーソルの位置ずれは大きくなり、直感的にダイレクトに所望の位置を指し示す事ができなくなる。つまり離れた位置でカーソルを移動しようとする場合、所望の位置を指し示したと思って座標入力ペン４のペンサイドＳＷ４２ａないし４２ｂをオンさせて座標を入力する事になるが、得られた座標値に基づくカーソルの位置は、前述の所望の位置とは異なり、カーソルの位置を視認しながら、操作者が座標入力ペン４を移動させることによって、所望の位置へカーソルを移動することができるようになる。
【０１１７】
言い換えれば、遠隔入力（ディスプレイ６から離れた位置で座標を入力し、例えばカーソルを移動させる動作）の場合は、操作者による視覚情報に基づき操作者の脳が補正動作を行う（座標入力ペン４を移動させる）ループを繰り返して、目的を達成することになるのであって、ダイレクトに所望の位置を指し示すことは困難なのである。
【０１１８】
この様に、ディスプレイ６に表示されている画像情報（ＸＹ平面上に座標系を有する画像情報）に対して、何らかの遠隔入力操作を行おうとする場合、操作者が一連の座標入力を行おうとする際の最初の１点目の座標値と前述の画像情報の座標値は、一致させることができない。このことは、例えばＯＨＰ等により表示されている表示画像を指示する道具としてレーザポインタが普及しているが、やはりレーザ発光時の最初の１点目は、どこを指示するか解らず、指示されたポイント位置を見ながら、位置修正動作をして所望の位置にレーザを照射することができる様になることを考えれば明らかである。
【０１１９】
そこで本実施形態では、ステップＳ５０９においてＺ座標値が所定値以上である場合（遠隔入力）には、まず最初に有効となる座標値を所定座標値（Ｘ1,Ｙ1,Ｚ1）として記憶し（この時、表示画面に表示されているカーソルの位置は移動しない）、連続入力期間中の座標入力ペン４の移動に伴ない、逐次座標値として差分値を出力することにより、ペン４の移動方向と移動量分だけカーソルを移動させることで、遠隔操作の場合であっても、優れた操作性を実現できるように構成した。
【０１２０】
図１２は、ディスプレイ６の表示範囲と座標入力の有効な領域で図１１のフローチャートの処理により切り替えられる座標出力モードのそれぞれの出力範囲を示している。ディスプレイ６に比較的近い位置にあって、検出されたｘ，ｙ座標が表示領域内にあるときには、ダイレクトに座標を入力できる絶対座標を出力し（出力モード１）、一方、聞き手の視野をさえぎらないディスプレイ６の脇で、或いはディスプレイ６から離れた位置で遠隔操作を行う場合には、相対座標を出力する（出力モード２）様に構成したことを示している。
【０１２１】
さらに遠隔操作の場合を考えると、直接画面をタッチする事でダイレクトに座標を入力する場合には、大型ディスプレイであることを考慮すれば、画面の端から端までカーソルを移動しようとすると、必ず体の移動を伴なう。しかしながら遠隔操作の場合には、例えば質問者が起立をしてその場で質問するのが通常であり（大勢の聞き手がいる場合は、必然的に移動は困難）、体を移動せずその場において全領域を指し示す事ができることが望まれる。本実施形態の構成は、この点についても問題を解決するものである。図１３（Ａ）を用いてそのことを以下に説明する。
【０１２２】
図１２に示した相対座標（差分値）出力範囲において、大勢の聞き手に対して、大画面を有するディスプレイ６を用いて操作者がプレゼンテーションをしようとしている場面を想定する。図１３（Ａ）に示すように、カーソルの位置を▲１▼の位置から▲３▼の位置へ移動しようとした場合、従来では座標入力ペン４を▲３▼の位置に持っていって、その位置で座標入力を行えば、カーソルは▲１▼の位置から▲３▼の位置に移動することになる（この場合、操作者は▲３▼の位置を指す事ができる位置にいる）。しかしながら、▲１▼の位置で作業した後（操作者は▲１▼の位置近傍にいる）、▲３▼の位置へ移動しようとする場合には、画面を横断するように操作者が移動するので、多くの聞き手にとっては視界を遮られ、プレゼンテーションの内容理解に支障をきたす。特に大型ディスプレイがフロントプロジェクション、ＯＨＰ（投射型の表示装置）等の場合には、その画像が大きく歪むのでなお更である。
【０１２３】
それに対し、本実施形態の構成において、操作者がディスプレイ６の脇にあって、カーソルが▲１▼の位置にあったと仮定する。操作者がＡの位置に座標入力ペン４を保持し、ペンサイドＳＷ４２ａ，４２ｂの少なくとも一方（以下、符号４２で示す）をオンさせることで、座標入力ペン４からは音波が放射され、座標入力ペン４の位置座標を検出することになる。この時、座標入力ペン４はディスプレイ６の表示画面の表示領域外、或いはディスプレイ６より離れた位置（Ｚ＞所定値）にあるので、最初に検出された位置座標は記憶されるが（図１１ステップＳ５０８）、カーソルは▲１▼の位置から移動されることはない。引き続き、操作者がペンサイドＳＷ４２をオンさせて連続的に座標を入力するように動作させながら座標入力ペン４をＢの位置に移動させた後、ペンサイドＳＷ４２をオフさせたとする。そうすると、操作者による座標入力ペン４の位置Ａから位置Ｂへの移動にともない、その移動方向と移動距離に応じて、カーソルが▲１▼の位置から▲２▼の位置へ移動することになる。さらに操作者がペンサイドＳＷ４２をオフした状態で座標入力ペン４をＢの位置からＣの位置へ移動させた（このとき座標入力がないので、カーソルは▲２▼の位置で動かない）後、Ｃの位置でペンサイドＳＷ４２をオンさせて座標入力ペン４をＤの位置へ移動すれば、Ｃの位置から音波が発生して最初に検出された座標値が再度記憶され（ステップＳ５０８）、その後に検出された座標値と記憶された座標値の差分量だけカーソルが移動して、操作者の座標入力ペン４の移動動作（地点ＣからＤへの移動）にともない、その移動方向と移動距離にて、カーソルが▲２▼の位置から▲３▼の位置へ移動することになる。
【０１２４】
以上説明したように、操作者は座標入力面であるところのディスプレイ６の表示画面から離れた位置、或いは表示領域の外側の位置に有っても、現状のカーソルの位置から、スムーズに所望の位置にカーソルを移動することが可能となるばかりでなく、その座標入力が連続して行われている一連の間は、座標入力ペンのＸ方向の移動量、Ｙ方向の移動量は、カーソルの移動量と１対１に対応しているので、文字や図形を入力したりすることもできる。
【０１２５】
文字や図形を入力する場合を図１３（Ｂ）を用いて説明する。まずペンサイドスイッチ４２ａ，４２ｂのどちらか一方のみをオンさせたペンアップ状態で座標入力ペン４を移動させて、カーソルを▲１▼の位置から所望の▲２▼の位置に移動し、その後ペンサイドＳＷ４２ａ，４２ｂの両者をオンさせてペンダウン状態として、座標入力ペン４の移動によりカーソルを▲２▼の位置から▲３▼の位置に移動させることにより、その移動方向と移動量に応じた軌跡が画面上に残る。その後、ペンサイドスイッチ４２ａ，４２ｂの一方をオフして（残りの一方はまだオンしており、連続的に座標が検出されている状態は維持されている；ペンアップ状態）、座標入力ペン４の移動によりカーソルを▲３▼の位置から所望の▲４▼の位置へ移動させた後、オフしたペンサイドＳＷを再びオンさせてペンダウン状態として座標入力ペン４の移動によりカーソルを▲４▼の位置から▲５▼の位置まで移動させれば、再びその移動の軌跡が入力される。そして▲５▼の位置でペンサイドスイッチ４２ａ，４２ｂを共にオフさせれば、座標入力が終了し、『い』の文字の軌跡が筆記入力されたことになる。
【０１２６】
ここで操作者は、最初の▲２▼の位置まではカーソルを視認しながら座標入力ペン４の移動動作により移動する必要があるが、その後の『い』と言う文字の筆記には、カーソルを視認しなくても座標入力ペン４の絶対的な移動量、つまり直感的な手、腕の操作で文字入力が行える。つまり、連続入力期間中の最初の有効な座標値を基準とすることで、その連続期間中に出力される座標は相対的になるが、操作者からみれば、その期間中はカーソルの移動量と手、腕の動作が対応しており、あたかも空間に座標入力面があるが如く、直感的な入力動作で文字入力を行なうことができる。
【０１２７】
この様に、操作者は自然な動作によって表示情報を制御したり、文字、図形等の情報を筆記入力したりすることが可能であり、また多くの聞き手にとっては、表示情報が遮られること無く、操作者である話し手の意図する内容を効率良く理解することが可能となる。
【０１２８】
さらには本実施形態では、大画面を有するシステムの使い勝手を考慮し、絶対座標を出力するモードと相対座標を出力するモードが、算出される座標値によって自動的に切り替わるので、操作者にとって特別な動作（例えば、座標入力装置の出力モードをスイッチ手段等により切り替える）を必要とせず、プレゼンテーションに集中できるという優れた操作環境を提供することが可能となる。
【０１２９】
また本実施形態では、相対座標を出力する状態にあって、検出した座標値との差分を得るための基準となる座標値（Ｘ1,Ｙ1,Ｚ1）を、連続入力期間中に最初に有効となる座標値と定義している。この理由を以下に詳述する。
【０１３０】
操作者にとって表示領域近傍においては表示領域の境界を認識するのは容易であるが、表示領域から離れるに従ってこの認識はあいまいなものになる。さらには、図１１のステップＳ５０９でのＺ軸方向の所定値の数値は、操作者が設定可能な数値であってかまわないが、その数値を認識していたとしても、その所定値によるＺ軸方向の実際の境界を区別するのは困難である。一方、最初に座標を入力する事によって、操作者が絶対座標の形態で出力が行われているのか、相対座標の形態で出力が行われているのかを認識するのは、例えば座標入力ペン４の位置とカーソル位置の関係で容易に理解できる。しかしながら、例えば出力形態が変更となる境界付近で動作させた場合、モードの切替動作が多発すると、出力形態の変更が多発し、操作者にとって扱い難い仕様となってしまう。
【０１３１】
そこで本実施形態では、座標入力ペン４から放射されるスタート信号の周期を監視して、連続的に座標入力が行われているのかを判定し、連続入力期間に最初に有効となった座標値を基準座標値とし、連続入力期間中、それ以降に算出された座標値と基準座標値との差分を出力する様に構成したので、ペンサイドＳＷ４２ａ，４２ｂのいずれかがオンしている限りは、この基準座標が保持され、たとえ切替の境界の近傍での座標入力動作であっても、操作者にとっての座標系、及び絶対なのか相対なのかが連続座標入力期間中は固定されるので、操作性の良い座標入力装置を構成する事ができる。
【０１３２】
言い換えれば、操作者はまず座標を１点入力する事によって、その座標出力形態を知る事が可能であり、それ以降連続して座標入力動作を行っている間は、そのモードが固定されるので、操作者はそれ以降モード切替のための境界を意識する必要がない。
【０１３３】
なお、本実施形態では、座標入力装置が座標値と共に座標モード情報（絶対座標なのか相対座標なのかを示す情報）を外部機器等に出力するようにしてもよいとしたが、座標入力装置が絶対座標値のみを出力するものとし、その出力結果を受け取るホスト装置、例えばパーソナルコンピュータ側でその受け取った座標値と座標値を受け取ったタイミング（連続的に座標入力が行われているか否かを判定する）を監視することで、図１１で説明した座標出力モードの切り換え及び平均化処理と同様の処理を行なうように構成してもよい。
【０１３４】
さて本実施形態では、絶対座標を出力するか、相対座標を出力するかの判定は、検出された座標値に基づき、ディスプレイ６からのＺ軸方向の距離、及びディスプレイ６の表示領域内にあるか否かで判定している。従って、座標入力装置の座標系において、表示領域がどの範囲に有るかを設定できることが好ましい。特にディスプレイ６にフロントプロジェクタを用いた場合には、会議毎に設置の仕方が異なることを考慮すると、表示サイズは常に一定とはならない（フロントプロジェクタの表示サイズはその投射距離に依存する）ので、表示領域を設定する手段が必須となる。また、固定された表示画面（例えばリアプロジェクタやプラズマディスプレイ等）を有するシステムであっても、座標入力装置とディスプレイ６の座標系を一致させるのは、組み立て時においてコスト的に不利な調整工程が必要であり、座標入力装置とディスプレイ６を組み合わせた後に、表示領域を設定できるように構成するのは、製造上の利点も大きい。また上述したように、座標入力装置の出力が絶対座標のみであって、その出力を受け取った例えばパーソナルコンピュータが、動作モードを判定する方法にあっては、やはりディスプレイ６が固定されているとは限らないので、パーソナルコンピュータに表示領域を知らしめる手段が必要となる。
【０１３５】
図１４は、この点を鑑みなされた表示領域を設定する処理の手順を示すフローチャートである。この処理を行なうための制御プログラムがマイクロコンピュータ３０１のＲＯＭ３０１ｂに格納され、ＣＰＵ３０１ａにより実行される。
【０１３６】
図１４の処理を行なうに当たって、操作者はディスプレイ６の長方形の表示領域（表示画面）の４隅の位置のそれぞれを座標入力ペン４で指示して４隅の位置の座標入力を行なうものとする。
【０１３７】
これに対して、図１４の処理では、まず変数contを０にして処理を開始し（ステップＳ６０１）、変数contをインクリメント（ステップＳ６０２）した後、座標検出に必要な有効な音波信号とスタート信号が検出されるのを待つ（ステップＳ６０３）。そして有効な信号が検出されたら、それに基づいて座標入力ペン４の指示位置（音波発生源４３の位置で上記４隅の内のいずれか１つの位置）の座標値Ｘcont,Ｙcontを算出し、ＲＡＭ３０１ｃに記憶する（ステップＳ６０４）。
【０１３８】
次に、変数contが４より大きくなったか確認し（ステップＳ６０５）、そうなるまでステップＳ６０２〜Ｓ６０５の処理を合計４回繰り返す。
【０１３９】
こうして表示領域の４隅の位置のそれぞれの座標を検出して記憶した後、４隅の位置の座標値から、図６に示した座標系の原点Ｏに対してＸ軸方向に±Disp＿X、Ｙ軸方向に±Disp＿Yで示される表示領域（ディスプレイ６の表示画面の領域）を算出する（ステップＳ６０６）。ここでは例えば左上隅のｘ座標値と左下隅のｘ座標値を平均化した値を、左側のｘ方向の境界値と定義したり、あるいは４隅を結んだ４角形の領域を定義して、座標出力形態を決定する条件式とする。
【０１４０】
なお、ここでは表示領域の４隅の位置の座標を検出する事で、表示領域を導出するものとしたが、これに限定されるものではなく、例えば４隅の内の３箇所の位置の座標を検出して導出するようにしてもよく、或いは座標入力ペン４で表示領域の４辺をなぞってその４辺の座標値を検出し、その情報から表示領域を設定してもよい。
【０１４１】
ところで、座標入力装置の使い勝手を考慮すると、操作者がディスプレイ６の表示画面から離れた位置で、ペンアップ状態、出力モード２として座標入力ペンの移動により画面上のカーソルを移動させる場合、操作者と表示画面の距離が大きくなる程、座標入力ペン４の僅かな動きでカーソルを大きく移動できるようにするのが好ましい。この点を考慮し、このような場合に、検出したｚ座標の絶対座標値が大きくなる程、あるいは座標算出に用いるペン４と検出センサ３ａ〜３ｄ間の測定距離の内の最長距離が大きくなる程、検出したｘ，ｙの相対座標値（差分値）をより大きな拡大率で拡大して出力するようにしてもよい。
【０１４２】
また、本実施形態では第２の実施形態と同様の移動平均化処理を行なうものとしたが、第１の実施形態と同様の単純な平均化処理を行なってもよい。その場合、第１の実施形態と同様に、平均化処理により座標サンプリングレートが実質的に低下するが、第１の実施形態で説明したのと同様の理由によりユーザの使い勝手上で問題はない。
【０１４３】
［他の実施形態］
以上に説明した第１〜第３の実施形態では、検出座標値を平均化する方法として、連続的に検出される座標値を単純に算術平均する、ないしは算術平均であって移動平均するものとしたが、その他の方法として、サンプルの座標値に重み付けして（例えば、より直近に検出された座標値の重みをより大きくして直近の座標値の影響度を増す）、平均化を行なうようにしてもよい。
【０１４４】
また、第１〜第３の実施形態では、検出座標値の平均化処理として、検出した座標値を平均化するものとしたが、座標入力装置が座標を算出するための測定パラメータを平均化することにより、結果的に座標値が平均化されるようにしてもよい。つまり、座標算出のためにまず音波発生源４３から検出センサ３ａ〜３ｄまでの距離を測定する構成であるので、平均化サンプル数分の距離を測定して、その平均距離を算出し、その平均距離を用いて座標値を算出するようにしてもよい。また、音波発生源４３から検出センサ３ａ〜３ｄまでの音波の到達時間を計測しているので、平均化サンプル数分の到達時間を計測して、その平均の到達時間を算出し、その平均の到達時間を用いて座標値を算出するようにしてもよい。
【０１４５】
また、第１〜第３の実施形態の座標入力装置は空中音波方式のものとしたが、これに限らず、所定周期毎に信号発信源から発信される信号を複数の受信手段により受信して、信号発信源から複数の受信手段までの距離のそれぞれを計測し、計測した距離のそれぞれに基づいて信号発信源の位置の座標を検出する方式の座標入力装置ならば、一般に測定距離の増大と共に距離測定分解能が低下するので、本発明に関わる検出座標値の平均化処理、ないしは計測した距離の平均化処理を適用することにより、測定距離の増大に伴う座標検出分解能の低下を補償することができる。
【０１４６】
また、第１〜第３の実施形態の座標入力装置は、ｘ，ｙ，ｚの３次元座標を検出可能なものとしたが、これに限らず、２次元座標のみ、或いは１次元座標のみを検出可能な座標入力装置においても、本発明に関わる検出座標値の平均化処理、ないしは計測した距離の平均化処理を適用することにより、測定距離の増大に伴う座標検出分解能の低下を補償することができる。
【０１４７】
ところで、第１〜第３の実施形態の構成において、ディスプレイ６の表示画面の直近では、主に文字や図形を筆記入力する事に使われる事を考慮すると、座標入力ペン４の移動は主に指、手首の運動によって行われる。一方、画面より離れた位置での操作は、表示画面上の所望の位置を指示するのに用いられるので、座標入力ペン４の移動は腕、指、手首の運動、さらには体の向きを変化させたりして、例えば表示されているカーソルを即座に大移動できることが望ましい。つまり、画面直近よりも、画面遠方において座標入力ペン４の指示に応じたカーソルの移動速度は速くなるのが通例である。
【０１４８】
これに関して第１〜第３の実施形態のように所定周期毎に座標入力ペン４の位置座標を検出する座標入力装置にあっては、前記『所定周期』と検出座標値ないし計測距離の変化分により座標入力ペン４の移動速度を検知することが可能である。
【０１４９】
従って、座標検出する際に、例えば『画面直近にも関わらず、座標入力ペン４の移動速度が異常に速い座標が検出された』場合には、座標値の誤検出が行われたものとして判断することができる。この点に着目して、座標入力ペン４の移動速度に関して、検出した座標値ないしは座標入力ペン４から特定の検出センサ３までの距離の計測値に基づき最大の許容移動速度を設定し、最大許容移動速度を超える速度で検出された座標値は誤検出座標であると判断することができる。例えば、ある検出時点での座標入力ペン４から特定の検出センサ３までの距離と、次の検出時点での座標入力ペン４から前記検出センサまでの距離を比較し、その差分値が前述の許容最大速度で定義されている距離よりも大きければ、距離測定の際に誤検出したと判定できる。そして誤検出と判定した場合にその座標値を無効とすることで、信頼性の高い座標入力装置を構成する事が可能となる。
【０１５０】
【発明の効果】
以上の説明から明らかなように、本発明によれば、座標指示具が表示画面から離れるのに応じて座標値の平均値を算出するためのサンプル数が多くなるように設定することにより、座標指示具が表示画面から離れていても、指示の揺らぎが大きくなることを抑制することができ、操作性に充分配慮されて使い勝手の良い優れた座標入力装置を提供することができる。さらに、連続的な座標値の検出が中断すると、平均値を演算するための処理を終了するので、信頼性の低い平均値が出力されてしまうことを防止することができるという優れた効果が得られる。
【図面の簡単な説明】
【図１】本発明の実施形態における座標入力装置の全体の構成を示す概略構成図である。
【図２】同装置の座標入力ペンの側面図及び後面図である。
【図３】同装置の座標検出に関わる信号処理を説明するタイミングチャート図である。
【図４】同装置の信号波形検出回路の構成を示すブロック図である。
【図５】同装置の演算制御回路の構成を示すブロック図である。
【図６】同装置の座標系を示す説明図である。
【図７】第１の実施形態における検出座標値の平均化処理の手順を示すフローチャート図である。
【図８】第２の実施形態における検出座標値の平均化処理の手順を示すフローチャート図である。
【図９】座標入力ペンの動作モード及び座標出力モードと、座標入力ペンの各スイッチのオン、オフ、及び座標算出値との関係などを示す表図である。
【図１０】第３の実施形態における座標入力ペンのスイッチのオン、オフに応じたペンアップ、ペンダウン状態の切り換え処理の手順を示すフローチャート図である。
【図１１】同実施形態における座標出力モードの切り換え及び平均化処理の手順を示すフローチャート図である。
【図１２】同実施形態におけるディスプレイの表示範囲と、絶対座標出力範囲及び相対座標出力範囲との関係を示す説明図である。
【図１３】同実施形態における座標入力ペンによるカーソル移動動作と文字の筆記入力動作の説明図である。
【図１４】同実施形態における表示範囲設定処理の手順を示すフローチャート図である。
【図１５】レーザポインタにおける照射距離と輝点（指示点）の揺らぎ幅との関係、及び照射距離とレーザポインタを保持した手元の振れ角との関係を示すグラフ図である。
【図１６】空中音波方式の座標入力装置における座標検出のための測定距離と測定分解能の関係を示すグラフ図である。
【符号の説明】
１ 演算制御回路
２ 信号波形検出回路
３ａ〜３ｄ 検出センサ
４ 座標入力ペン
５ 受光素子
６ ディスプレイ
７ ディスプレイ駆動回路
４１ ペン先スイッチ
４２ａ，４２ｂ ペンサイドスイッチ
４３ 音波発生源
２１０ エンベロープ検出回路
２０６ ２階微分回路
２０７ Ｔg信号検出回路
３０１ マイクロコンピュータ
３０１ａ ＣＰＵ
３０１ｂ ＲＯＭ
３０３ タイマ
３０４ａ〜３０４ｄ ラッチ回路[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a coordinate input device, a coordinate value output method, and a program.
[0002]
[Prior art]
Conventionally, a coordinate input device capable of inputting coordinates is superimposed on a display screen of a display device such as a CRT display, a liquid crystal display, or a projector, and pointing (instruction) or writing handwritten by an operator is displayed. There is known an apparatus that can realize a relationship like paper and a pencil. As the coordinate input device, a resistive film method, an electrostatic method, an ultrasonic method for propagating ultrasonic waves to a coordinate input surface such as glass, an optical type, or an acoustic wave (in the air) A mechanism for coordinate detection is placed on the back side of the display device, such as an aerial sound wave method that detects the position by emitting (ultrasonic waves), and an electromagnetic induction (electromagnetic transfer) method, and the front of the display device is transparent. There is also a thing that constitutes an information device integrated with input and output by arranging a protective plate.
[0003]
Such devices start with small portable electronic notebooks, and with the increase in the size of display devices such as pen input computers, relatively large information devices can be seen. In combination with a large display device such as a rear projector, a large liquid crystal display, or a PDP, it has begun to be used in, for example, a presentation device or a TV conference system.
[0004]
In particular, a device that combines a large display device and a coordinate input device is replaced with a whiteboard or electronic blackboard that has been used in the office, and a data display prepared in advance on a personal computer is displayed on a large screen display. It is starting to be used for applications and meetings. In that case, in order to update the information displayed on the display by an operator or attendee like a whiteboard, the display contents of the display screen can be controlled by directly touching the screen and controlling the personal computer by the coordinate input by the touch. It is comprised so that it can switch.
[0005]
In such a device, considering a meeting assuming a large number of participants and the network era, the operator can not only control the personal computer by touching the screen directly as described above, but also while watching the screen, for example. Operation of the screen (control of display information, desired position, etc.) even at a position away from the screen so that conference participants listening to the presentation contents can display questions or evidence for objection. And the like, and the information can be extracted from the network as necessary.
[0006]
Furthermore, considering a presentation using a large screen display, the operator (presenter) usually stands at a position away from the screen in order to recognize the entire projected image. As is clear from the presentation using OHP or the like, the distance between the operator and the screen becomes longer as the image size increases. In this case, a laser pointer or pointer that does not obstruct the line of sight of the participant who is viewing the screen is commonly used as a means for indicating the desired position on the screen. An aerial acoustic wave (ultrasonic wave) type coordinate input device configured as described above is known (see Patent Document 1).
[0007]
In the apparatus, sound waves (ultrasonic waves) emitted in the air from a plurality of sound wave generating means arranged along the longitudinal direction of an indicating tool (indicating pen) for indicating a coordinate input position are arranged around the display screen. Further, the coordinates of the positions of the plurality of sound wave generating means are calculated by detection by three or more sound wave detecting means, and then the intersection (indicating point) between the straight line passing (connecting) the positions of the plurality of sound wave generating means and the display screen The coordinates of are derived.
[0008]
[Patent Document 1]
Japanese Patent Publication No. 7-97304
[0009]
[Problems to be solved by the invention]
However, in the instructions in the above-described aerial sound wave type coordinate input device that can give instructions as a pointer, as is clear from the operability of the laser pointer, the instructions on the screen increase as the distance between the pointing tool and the screen (indicating surface) increases. There was a problem that the fluctuation of the points became large. This problem will be described with reference to FIG.
[0010]
FIG. 15A shows the case where the operator holds the laser pointer from one of the positions at different distances from the screen of the screen for a predetermined time and continues laser irradiation toward one point on the screen. The result of the experiment which measured the width | variety by which the bright spot (indication point) of the laser irradiated on the screen fluctuates by the held hand shake is shown. The longer the irradiation distance, the larger the fluctuation width, and the width reaches about 90 mm at the irradiation distance of 10 m. That is, if the irradiation distance is increased, the operator cannot continue to indicate a desired point.
[0011]
FIG. 15B shows the result of FIG. 15A as a result of the deflection angle Θ (= tan) of the hand holding the laser pointer.^-1 It shows the results organized by [(brightness of the bright spot on the screen / 2) / (irradiation distance)]. Here, since the hand deflection angle Θ is almost constant (about 0.3 °) without depending on the irradiation distance, it can be understood that the laser bright spot shake is mainly caused by the deflection angle Θ.
[0012]
Even in the aerial acoustic wave type coordinate input device capable of performing the instruction as the pointer, even when the coordinate detection accuracy is high, when the screen is instructed in the same manner, the human holding ability of holding the pointing tool is approximately Since there is a hand shake angle of 0.3 °, the pointing point fluctuates, and the swinging distance increases as the distance between the pointing tool and the screen increases. As a result, when a desired position on a large screen such as an OHP is pointed from a position away from the pointing tool by this kind of coordinate input device, the pointing point (intersection point mentioned above) fluctuates and the cursor displayed at the pointing point The problem was that the presentation participants watching the screen felt uncomfortable, annoyed, and tired. This problem is not limited to the aerial sound wave method, but is common to coordinate input devices configured to be able to give a linear instruction as a pointer using an indicator.
[0013]
On the other hand, the aerial acoustic wave type coordinate input device is not limited to the one configured to perform the instruction as the pointer described above, but the pointing device provided with the sound wave generating means and the sound wave detection arranged around the screen. There is a problem that the resolution of coordinate detection decreases as the distance to the means increases. This will be described below.
[0014]
Generally, in an aerial acoustic wave type coordinate input device, a sound wave (generally, a signal emitted into the air at predetermined intervals from a sound wave generating means (a sound wave signal transmission source) provided in a pointing device that indicates a coordinate input position. Is detected by a plurality of sound wave detection means (acoustic wave signal reception means) arranged on the screen of the display, for example, and the sound wave detection signal is processed by an analog circuit to reach the sound wave detection means. Measure the delay time until the sound wave arrives after detecting the timing, calculate the distance between the sound wave generation means and the sound wave detection means from the delay time, and calculate the coordinates of the position of the sound wave generation means based on the distance is doing.
[0015]
In contrast, the energy of sound waves propagating in the air attenuates exponentially as the propagation distance increases. Therefore, as the distance between the pointing tool and the sound wave detection means increases, the level of the sound wave detection signal of the sound wave detection means also attenuates exponentially. Along with this, the output of the analog circuit also decreases, and the sound wave component (acoustic noise) other than the electrically converted signal and the ratio of the electrical noise to the signal existing on the circuit, that is, the S / N also decreases. . As a result, the detection resolution of the arrival timing is lowered, and the measurement resolution of the delay time is also lowered. As a result, as shown in FIG. 16, the measurement resolution of the distance decreases substantially in proportion to the measurement distance between the sound wave generation means and the sound wave detection means, and the coordinate detection resolution also decreases.
[0016]
Thus, for example, even in a device that is not configured to perform the linear instruction as the pointer described above (there is only one sound generator for the indicator), the position of the indicator at a position away from the display screen When controlling the position of the cursor on the display screen by inputting the X-axis and Y-axis coordinates, the coordinate detection resolution decreases as the distance between the pointing tool and the display screen increases, causing the problem that the cursor fluctuates greatly. It was.
[0017]
Note that the problem of the decrease in the coordinate detection resolution due to the increase in the measurement distance is not limited to the aerial acoustic wave type coordinate input device, but is transmitted at predetermined intervals from the signal transmission source provided in the pointing device that indicates the coordinate input position. A plurality of receiving means, and each of the distances from the signal transmission source to the plurality of receiving means is measured, and the coordinates of the position of the signal transmission source are determined based on each of the measured distances. This is common to the coordinate input device of the detection method.
[0018]
The present invention has been made in view of the circumstances as described above, and the problem is that the coordinate input device can compensate for the decrease in the coordinate detection resolution accompanying the increase in the measurement distance for coordinate detection described above. At the same time, it is possible to suppress an increase in fluctuation of the pointing point on the pointing surface accompanying an increase in the distance to the pointing surface (coordinate input surface), which is a problem particularly when configured as a pointer.
[0019]
[Means for Solving the Problems]
  In order to solve the above problems, according to the present invention,
  The display screen in which the coordinate value in the horizontal direction and the vertical direction of the display screen and the coordinate value in the direction orthogonal to the display screen, which are instructed by the coordinate pointing tool, are continuously detected and detected continuously. A coordinate input device that outputs an average value of coordinate values in the horizontal and vertical directions of
  Based on the coordinate value first detected in the detection of the continuous coordinate value, so that the number of samples for calculating the average value increases as the coordinate indicator moves away from the display screen, Setting means for setting the number of samples for calculating the average value;
  When the coordinate value of the number of samples calculated based on the coordinate value detected first in the detection of the continuous coordinate value is continuously detected, the horizontal direction of the display screen detected continuously And an output means for outputting an average value of coordinate values in the vertical direction,
  When the detection of the continuous coordinate value is interrupted before the coordinate value of the number of samples calculated based on the coordinate value detected first in the detection of the continuous coordinate value is continuously detected, It has an end means for ending the process for calculating the average value of the coordinate values in the horizontal and vertical directions of the display screen.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. Here, an embodiment of an aerial acoustic wave type coordinate input device capable of detecting three-dimensional (space) coordinates is shown.
[0025]
[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS.
[0026]
FIG. 1 shows an overall schematic configuration of a coordinate input apparatus according to this embodiment. In FIG. 1, reference numeral 4 denotes a coordinate input pen which is an indicating tool for indicating a coordinate input position, and generates sound waves (audible sound waves but ultrasonic waves are preferable) in the air by an operation by an operator. It is configured as follows. The generated sound wave is detected by a plurality (here, four) of detection sensors 3a to 3d arranged around the display screen of the display 6, and each detection signal is processed by the signal waveform detection circuit 2 by a method described later. Then, the arrival timing of the sound wave to the detection sensors 3a to 3d is detected, whereby the arrival time of the sound wave to the detection sensor is measured in the arithmetic control circuit 1, and based on this, the coordinates of the position of the sound wave generation source of the coordinate input pen 4 are measured. (X, Y, Z) is configured to be calculated.
[0027]
The arithmetic control circuit 1 controls the entire apparatus and moves the cursor displayed on the display 6 or displays writing information such as characters and figures via the display driving circuit 7 based on the obtained coordinate data. The display 6 can be displayed and added.
[0028]
In this manner, by combining the coordinate input device and the display 6, when the coordinate input pen 4 is operated on the display screen of the display 6, a man-machine interface that can realize a relationship like paper and pencil. When the coordinate input pen 4 is operated at a position away from the display screen, screen control by remote operation can be performed by moving the cursor on the display screen, for example.
[0029]
Next, the details of the configuration and operation of the coordinate input device will be described. First, the configuration of the coordinate input pen 4 will be described with reference to FIG. The coordinate input pen 4 includes a sound wave generation source (sound wave signal transmission source) 43, a drive circuit 45, and a power supply 46. The sound wave generation source 43 is driven by the drive circuit 45. The drive circuit 45 includes a timer, an oscillation circuit, a control circuit that detects and controls operation information of the plurality of switches 41, 42 a, and 42 b provided in the coordinate input pen 4. The drive signal of the sound wave generation source 43 is a pulse signal that is emitted by the timer and is repeated at a predetermined cycle, and is amplified by the oscillation circuit with a predetermined gain and then applied to the sound wave generation source 43. This electrical drive signal is converted into mechanical vibration by the sound wave generation source 43, and sound waves due to the vibration are radiated into the air. On the other hand, an optical signal synchronized with the sound wave emission timing is transmitted from a light emitting means 44 such as an infrared LED.
[0030]
The coordinate input pen 4 includes a pen tip switch 41 that operates by pressing the tip of the pen, and two pen side switches 42 a and 42 b provided on the side surface of the coordinate input pen 4. The drive circuit 45 drives the sound wave generation source 43 when any of these switches is pressed and turned on.
[0031]
The period of the drive signal applied from the drive circuit 45 to the sound wave generation source 43 is, for example, 10 msec. In this case, the sound wave is emitted 100 times per second, and the coordinate output sampling rate is 100 times / second. A sound wave and an optical signal as a start signal are emitted from the coordinate input pen 4 at each cycle.
[0032]
The emitted sound wave is delayed by a time corresponding to the distance from the sound wave generation source 43 to each of the detection sensors 3a to 3d and reaches each of the detection sensors 3a to 3d to be detected. Each of the detection signals is input to the signal waveform detection circuit 2, where the arrival timing of the sound wave to each of the detection sensors 3a to 3d is detected from the waveform of the detection signal. The operation will be described below with reference to FIGS. FIG. 3 is a timing chart of each signal, and FIG. 4 is a block diagram showing a configuration of the signal waveform detection circuit 2.
[0033]
In FIG. 3, reference numeral 101 denotes a drive signal generated by the drive circuit 45 of the coordinate input pen 4. Simultaneously with the generation of the drive signal 101, as a start signal for starting the measurement of the arrival time of the sound wave as described later. The light signal is emitted from the light emitting means 44. This optical signal is received by the light receiving element 5 provided near the display screen of the display 6 as shown in FIG. 1, and detected by the frequency detection circuit 210 of the signal waveform detection circuit 2 shown in FIG. The signal is detected by the circuit 211 and input to the arithmetic control circuit 1. As a result, the timer 303 of the arithmetic control circuit 1, which will be described later, starts timing.
[0034]
On the other hand, the sound wave generation source 43 of the coordinate input pen 4 is driven by the drive signal 101, the sound wave is radiated into the air, and a delay time corresponding to the distance between the sound wave generation source 43 and each of the detection sensors 3a to 3d is applied. It reaches the detection sensors 3a to 3d and is detected.
[0035]
In FIG. 3, the detection sensor 3 is representative of each of the detection sensors 3 a to 3 d, and the configurations of reference numerals 201 to 207 are provided for the detection sensors 3 a to 3 d, respectively.
[0036]
The sound wave detection signal of the detection sensor 3 is amplified to a predetermined level by the preamplifier circuit 201. The signal is indicated by reference numeral 102 in FIG. The sound wave detection signal 102 is processed by an envelope detection circuit 203 including an absolute value circuit and a low-pass filter, and only the envelope 103 of the signal 102 is extracted. Focusing on the envelope 103, the sound velocity at which the waveform propagates is the group velocity Vg. When a singular point of the waveform of the envelope 103, for example, a peak or an inflection point is detected, the sound wave from the sound wave source 43 to the detection sensor 3 is detected. A delay time (arrival time) Tg related to the group velocity Vg until reaching is obtained.
[0037]
In this embodiment, in order to obtain an inflection point, the envelope signal 103 is input to a second-order differentiation circuit 206 and a gate signal generation circuit 205 including a comparator. Second-order differentiation circuit 206 performs second-order differentiation on envelope signal 103 to generate second-order differentiation signal 106. The gate signal generation circuit 205 generates a gate signal 105 that opens (becomes low level) only while the level of the envelope signal 103 exceeds a predetermined threshold level 104.
[0038]
The second-order differential signal 106 and the gate signal 105 are input to a Tg signal detection circuit 207 including a zero cross comparator. The circuit 207 detects a point at which the second-order differential signal 106 first zero-crosses while the gate signal 105 is open as an inflection point, and generates a Tg signal 107 as the detection signal. The Tg signal 107 is input to the arithmetic control circuit 1, and the delay time Tg related to the sound wave group velocity Vg is measured by the Tg signal 107 in the circuit 1. Further, the distance L between the sound wave generation source 43 and the detection sensor 3 is obtained from the delay time Tg and the group velocity Vg by the following equation.
[0039]
L = Vg × Tg (1)
Strictly speaking, the delay time Tg includes the delay of the circuit related to the waveform processing. However, since the influence can be eliminated, here there is no circuit delay time in order to simplify the explanation. Will be described.
[0040]
Next, the configuration and operation of the arithmetic control circuit 1 will be described with reference to the block diagram of FIG. In FIG. 5 showing the configuration of the arithmetic control circuit 1, reference numeral 301 denotes a microcomputer that controls the arithmetic control circuit 1 and the coordinate input device as a whole. The CPU 301a is the main body of control, the ROM 301b stores a control program, and the workpiece. The area includes a RAM 301c used for calculation and the like, a non-volatile memory for storing constants (not shown), a counter, and the like.
[0041]
As described above, the start signal of the optical signal synchronized with the drive signal 101 of the sound wave generation source 43 of the coordinate input pen 4 is detected by the control signal detection circuit 211 of the signal waveform detection circuit 2 and input to the microcomputer 301. In response to this, the microcomputer 301 starts a timer 303 composed of a counter or the like. By doing so, since the drive timing of the sound wave generation source 43 and the start timing of the timer 303 are synchronized, the time until the sound wave generated by the sound wave generation source 43 reaches each of the detection sensors 3a to 3d (as described above). The delay time Tg) can be measured.
[0042]
Each time a sound wave reaches each of the detection sensors 3a to 3d and is detected, the sound wave arrival timing signals Tga to Tgd, which are the above-described Tg signals 107 from the detection sensors 3a to 3d, are input from the signal waveform detection circuit 2 as detection signals. The signals are input to the latch circuits 304a to 304d through the port 306, respectively. Each of the latch circuits 304a to 304d receives the timing signal from the corresponding sensor, and latches the time value of the timer 303 at that time.
[0043]
When the determination circuit 305 determines that all detection signals necessary for coordinate detection have been received in this manner, a signal to that effect is output to the microcomputer 301. In response to this, the microcomputer 301 reads the sound wave arrival times from the latch circuits 304a to 304d to the detection sensors 3a to 3d, performs a calculation described later, and obtains the coordinates of the position of the sound wave generation source 43 of the coordinate input pen 4. calculate. Further, the result of processing the obtained coordinate value (absolute coordinate value) by a method described later is output to the display drive circuit 7 via the I / O port 307, and for example, a dot or the like is provided at a corresponding position on the display 6. It can be displayed. Also, by outputting coordinate information to an external interface circuit (not shown) via the I / O port 307, coordinate values can be output to an external device.
[0044]
Next, a method of calculating the three-dimensional coordinates (x, y, z) of the position of the sound wave generation source 43 of the coordinate input pen 4 will be described with reference to FIG. As shown in FIG. 6, the detection sensors 3 a to 3 d are arranged in the vicinity of the four corners of the rectangular display 6, and the center of the flat display screen of the display 6 is set to the origin O (0, 0, 0), one axis passing through the origin O along the horizontal direction of the display screen in the display screen is the X axis, and one axis passing through the origin O along the vertical direction of the display screen in the display screen is the Y axis and X axis. One axis orthogonal to the Y axis is taken as the Z axis. Disp_X is the length of the display screen (display area) in the X-axis direction divided into two equal parts on the Y-axis, and Disp_Y is the length of the display screen (display area) in the Y-axis direction divided into two equal parts on the X-axis. Is the length.
[0045]
The distance between the sound wave generation source 43 and each of the detection sensors 3a to 3d determined as described above is La to Ld, the distance between the detection sensors in the X axis direction is Xs-s, and the distance between the detection sensors in the Y axis direction is the distance between the detection sensors. If Ys-s, from the three-square theorem,
[0046]
[Expression 1]

[0047]
It is. From this, the x coordinate of the position of the sound wave generation source 43 is obtained by the following equation.
[0048]
[Expression 2]

[0049]
Similarly, the y coordinate and the z coordinate are obtained by the following equations.
[0050]
[Equation 3]

[0051]
When the microcomputer 301 performs such calculation, the three-dimensional coordinates (x, y, z) of the position of the sound wave generation source 43 of the coordinate input pen 4 can be calculated.
[0052]
As can be seen from the above equations (3) to (5), for example, if the distances La, Lb, and Lc are known, that is, if the distance between the three detection sensors and the sound wave generation source 43 can be measured, the position coordinates of the sound wave generation source 43 are obtained. Can be calculated. In this embodiment, since four detection sensors 3a to 3d are used, for example, the information of the sensor farthest from the sound wave generation source 43 is not used (this sensor outputs data because the distance is the longest). (The signal level is the smallest), and coordinates are calculated only with the remaining three distance information, thereby enabling highly reliable coordinate calculation. Further, it is possible to determine whether the reliability of the output coordinate value is high by using the information of the sensor having the longest distance. As a specific method, for example, the coordinate values calculated by the distance information La, Lb, and Lc and the coordinate values calculated by the distance information Lb, Lc, and Ld should output the same value (the distance information If the two do not match, one of the distance information is invalid, that is, it has been erroneously detected. In this case, the reliability that the coordinate value is not output. It is also possible to implement a configuration that improves the above.
[0053]
The configuration described above merely inputs the three-dimensional coordinates of the position of the sound wave generation source 43 of the coordinate input pen 4, but the sound wave generation source is the same as that described in Patent Document 1. 43 are arranged so as to be arranged along the longitudinal direction of the coordinate input pen 4, the three-dimensional coordinates of the two positions are detected, and then the intersection of the straight line connecting the two positions and the display screen of the display 6 If the coordinates of the position are derived, it can be used as a pointer for linearly indicating a desired position on the display screen, similar to a laser pointer.
[0054]
By the way, in the present embodiment, in order to solve the above-described problems of the invention, a calculation process (hereinafter referred to as an averaging process) that averages the x-coordinate and the y-coordinate in a series of detected three-dimensional coordinates is referred to as a micro process. Performed by the computer 301 (CPU 301a).
[0055]
This averaging process is a process of calculating and averaging a series of x-coordinate values and y-coordinate values that are periodically detected sequentially, and as the z-coordinate value detected at that time increases, the averaging process is performed once. Increase the number of samples of coordinate values to be averaged (hereinafter referred to as the number of averaged samples).
[0056]
Details of the averaging process will be described below with reference to FIG. FIG. 7 is a flowchart showing the arithmetic processing procedure of the averaging processing, and an arithmetic processing program corresponding to this is stored in the ROM 301b of the microcomputer 301 and executed by the CPU 301a.
[0057]
In the process of FIG. 7, first, in step S101, an integer n indicating the number of samples of x, y, z coordinate values sequentially detected and stored as described later is initialized to 0, and then the coordinate input pen 4 It waits until the coordinate of the position of the sound wave generation source 43 is detected.
[0058]
Here, when coordinates are detected at a certain timing, the number of samples n is incremented by “1” in step S102 (in this case, n = 1 at first), and then the coordinate values (X, Y, Z) is stored in the RAM 301c as the coordinate value (Xn, Yn, Zn) of the nth sample.
[0059]
Subsequently, in step S104, it is determined whether or not the number of samples n = 1. If n = 1, the averaged number of samples Kend is set based on the Z coordinate value among the coordinate values detected in step S105. The setting method is as described above, as the Z coordinate value increases (in other words, as the coordinate input pen 4 is positioned further away from the display screen (Z = 0) of the display 6), The value of Kend may be set larger, and the increase method may be increased proportionally or exponentially according to the increase of the Z coordinate value, for example.
[0060]
After step S105 and if the number of samples n is not 1 in step S104, the process proceeds to step S106 to determine whether the value of the number of samples n matches the value of the averaged sample number Kend. In step S108, it is determined whether the coordinates are continuously detected. If the coordinates are continuously detected, the process returns to step S102 and the processes of steps S102 to S106 and S108 are repeated. Thereby, unless the continuous coordinate detection is interrupted, the coordinates sequentially detected until the value of the sample number n matches the value of the averaged sample number Kend in step S106 are stored.
[0061]
If the value of the sample number n matches the value of the averaged sample number Kend in step S106, the X coordinate value and the Y coordinate value (respectively averaged sample numbers) detected and stored in a series of operations in step S107. The arithmetic average (arithmetic mean) value of Kend coordinate values), that is, the quotient coordinate values Xave and Yave obtained by dividing the total value of each coordinate value by the averaged sample number Kend, The data is output to the display drive circuit 7 and other external devices via the I / O port 307. Here, the average value Zave of the Z coordinate values may also be calculated and output. For example, when two sound wave generation sources 43 are provided in the coordinate input pen 4 and configured as a pointer, all the X, Y, and Z coordinate values are averaged. Further, an average value of only one of the X, Y, and Z coordinate values may be calculated and output depending on the application.
[0062]
After outputting the average value in this way, a series of processing ends (step S109), the number n of samples in step S101 is initialized, and the process returns to the standby state.
[0063]
On the other hand, if coordinate detection is not continuously performed in step S108, that is, if the continuous detection state is interrupted, the process proceeds to step S109 even if the integer n has not reached the value of the averaged sample count Kend. End the process. This is because the coordinate value obtained by the averaging process is valid only when the coordinate detection is continuously performed.
[0064]
Here, a determination method of continuous detection of coordinates will be described. If the coordinate input apparatus can detect coordinates at a coordinate sampling rate of 100 times / second, coordinates are detected every 10 msec. By measuring this cycle, it is possible to determine whether coordinate detection is being performed continuously. Specifically, for example, the start signal generation timing of the optical signal detected by the control signal detection circuit 211 is monitored (in this case, if the sampling rate is 100 times / second, the start signal is generated every 0.01 second). It is determined whether or not it is in a continuous detection state. As another method, the arrival interval of the sound wave detection signal 102 in FIG. 3 is directly monitored. In this case, since the distance between the pen 4 and each of the detection sensors 3a to 3d constantly changes as the coordinate input pen 4 moves, the time based on the sampling rate (0.01 seconds if the sampling rate is 100 times / second). ), The difference in the transmission time of the sound wave accompanying the change in distance is increased or decreased. Therefore, it is expressed as a period of about 0.01 seconds (theoretically, a signal is always received within the range of 0 to 0.02 seconds), and the maximum movement of the pen 4 within 0.01 seconds practically. Considering the amount, for example, when a signal can be received within 0.015 seconds, it is determined that coordinate detection is continuously performed.
[0065]
As described above, as the detected z coordinate value increases, that is, as the distance between the coordinate input pen 4 and the detection sensors 3a to 3d increases, the x, y, or z coordinate values are averaged and output with a larger average number of samples. Thus, it can be compensated that the coordinate detection resolution decreases as the distance increases. That is, variations in detected coordinate values due to a decrease in coordinate detection resolution can be eliminated by averaging detected coordinate values, thereby substantially improving coordinate detection resolution. Then, when the position of the cursor on the display screen is controlled by inputting the X and Y coordinates of the position of the coordinate input pen 4 from a position away from the display screen of the display 6, it is possible to suppress the fluctuation of the cursor accompanying the increase in the distance. it can.
[0066]
Further, when the coordinate input pen 4 is provided with two sound wave generation sources 43 and configured as a pointer, as described above, the operator designates a desired position on the display screen with the pen 4 from a position away from the display screen. At this time, the fluctuation of the indication point on the display screen (the intersection of the two sound wave generation sources 43 and the display screen) due to the shake of the hand holding the pen 4 by the operator can be suppressed by the averaging process. That is, the fluctuation of the coordinate value of the position of the two sound wave generation sources 43 due to the shake of the hand holding the pen 4 can be suppressed by averaging, and thereby, on the display screen derived from the coordinate value. It is possible to suppress the change in the coordinate value of the designated point (the above intersection), that is, the fluctuation of the designated point. In this way, fluctuation of the indication point on the display screen can be suppressed and fluctuation of the cursor or the like displayed at the indication point can be suppressed, and an environment that is easy to see for the person viewing the display screen can be provided.
[0067]
However, the coordinate sampling rate is substantially reduced by the averaging process. For example, assuming that the value of the average number of samples Kend is set to Kend = 10 in step S105 of FIG. 7, for example, in the case of a coordinate input device having a performance of a coordinate sampling rate of 100 times / second, this averaging process causes external processing. The output of the coordinate value is reduced to 10 times per second. However, this is not a problem for the following reasons.
[0068]
From the viewpoint of the operator, Z = 0, that is, on the display screen of the display 6, the coordinate input pen 4 is used to input characters, figures, etc. and display the handwriting so that information can be obtained like a “whiteboard”. It is important to be able to record, and a sufficient coordinate sampling rate must be secured to faithfully reproduce the handwriting as characters and figures.
[0069]
However, as you move away from the screen, the function becomes less important. You can “specify” a specific position at a remote location, or “underline” a specific sentence, and “enclose (select) a specific area. The function of the rough movement like “)” becomes important. That is, even if the coordinate sampling rate is substantially reduced as the user moves away from the screen, the above-mentioned “rough operation” can be realized without any problem.
[0070]
In this embodiment, a time delay occurs with respect to coordinate calculation. In other words, if the coordinate calculation for the average number of samples Kend is not performed from the point when the coordinate is input, the coordinate output to the outside is not performed. For example, the sampling rate of the coordinate input device is 100 points / second and the averaged sample is used. If the number Kend is 10 times, a time delay of 10 msec occurs. However, as a result of investigation, it has been confirmed that with such a time delay, it can be operated without any problem as a human sense (interval in which coordinates are input but not output or feels delayed). When the averaged sample number Kend becomes a value larger than that, humans start to feel that it is delayed. However, the averaged sample number is set based on the distance between the sound wave generation source 43 and the detection sensors 3a to 3d. Since it is a relatively large distance, in other words, a distance sufficiently away from the display screen of the display 6, the purpose of use at that time (rough operation such as pointing instead of inputting fine characters and figures) can be considered. There is no practical problem. The same applies to the second embodiment described below and the third embodiment described later.
[0071]
[Second Embodiment]
In the averaging process of the first embodiment described above, the coordinate sampling rate is substantially reduced. A second embodiment for coping with this and performing the averaging process so that the coordinate sampling rate does not substantially decrease will be described with reference to FIG. The apparatus of the second embodiment is the same as that of the first embodiment except for the averaging processing method.
[0072]
FIG. 8 is a flowchart showing the arithmetic processing procedure of the averaging processing in the second embodiment, and an arithmetic processing program corresponding to this is stored in the ROM 301b of the microcomputer 301 and executed by the CPU 301a.
[0073]
In the processing procedure of FIG. 8, steps S101 to S109 are common to steps S101 to S109 of FIG. 7 of the first embodiment, and are different only by newly added step S110. Hereinafter, description of parts common to the processing of FIG. 7 will be omitted, and only different parts will be described.
[0074]
In the process of FIG. 7, the arithmetic average values Xave, Yave, and Zave of the averaged sample number Kend and the Y coordinate value or the Z coordinate value of the averaged sample number detected and stored in the previous operation are calculated in step S107. After outputting to the outside, the process is terminated (step S109), and the process returns to step S101, whereas in the process of FIG. 8, the process proceeds to step S110 after step S107.
[0075]
In step S110, the first (oldest) samples X1, Y1, and Z1 are erased for each of the Kend averaged sample numbers Kend stored in the RAM 301c in the previous operation. Then, the remaining sample Xn is stored again as Xn-1, Yn as Yn-1, and Zn as Zn-1. For example, if the average sample number Kend is 3, X2 is stored as X1 and X3 is stored as X2. Also, the sample number n is decremented by “1”.
[0076]
After step S110, the process proceeds to step S108 to check whether or not the coordinates are continuously detected. If the coordinates are continuously detected, the process returns to step S102, and the processes after step S102 are repeated.
[0077]
If the coordinates are not continuously detected in step S108, that is, if the continuous coordinate input operation is completed, all stored information such as the coordinate value and the averaged sample number Kend is reset. The process ends (step S109), and the process returns to step S101.
[0078]
According to such an averaging process of the present embodiment, as long as coordinate detection is continuously performed, after the number of detected coordinate samples reaches the average sample number Kend for the first time, the coordinates of one coordinate are detected. For each detection, the coordinates are averaged, the average value is output, and the moving average is output. Therefore, if the sampling rate of the original coordinates of the coordinate input device is 100 times / second, for example, 100 times / second is maintained as it is.
[0079]
As a result of an experiment using a coordinate input device with a sampling rate of 100 times / second adopting the configuration of the present embodiment, Z = 0 (input on the display screen, high-speed sampling for inputting characters and figures) If the number of samples to be averaged is 10 times or less, accurate character input can be performed without a sense of incongruity. From this point of view, even if the original coordinate detection resolution of the coordinate input device is relatively poor It can be seen that the coordinate detection resolution can be improved by adopting the configuration of the present embodiment. In addition, coordinate input can be performed at a higher sampling rate even from a location far from the display screen as compared to the first embodiment.
[0080]
In the first and second embodiments described above, the detected coordinate value is averaged in the coordinate input device, but is averaged in a host computer or the like that receives the coordinate value detected by the coordinate input device. Processing may be performed.
[0081]
Further, as a method for determining continuous detection of coordinates, in addition to a method for monitoring and determining coordinate output timing based on the sampling rate of the coordinate input device, for example, a predetermined time is set, and the time and coordinate output timing are set. You may judge by comparing.
[0082]
In the first and second embodiments, the averaged sample number Kend is determined based on the uniaxial coordinate value called the z coordinate value among the detected x, y, and z coordinate values. There is also a method for determining the number of averaged samples based on all of the y and z coordinate values. For example, a distance from the position of the coordinate value (the position of the sound wave generation source 43) to the origin O of the coordinate system that is the center of the display screen of the display 6 is calculated from the detected x, y, and z coordinate values. The number of averaged samples may be determined based on this. It is also conceivable to determine the averaged sample number Kend based on the two-axis coordinate values of the detected x, y, and z coordinate values.
[0083]
Further, as is known in the art, in the specification of setting the position coordinates relatively by the coordinate input device and controlling the position of the cursor on the display screen, the absolute coordinates of the position designated by the coordinate input pen 4 are used. Since the value and the cursor display position are different (relatively shifted), the cursor display position is first calculated as an absolute position, and the distance between the absolute position of the cursor and the absolute position of the coordinate input pen 4 is calculated. Then, the averaged sample number may be determined according to the distance.
[0084]
[Third embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. Note that the hardware configuration of the coordinate input device of this embodiment and the basic operation of coordinate detection are the same as those in the first and second embodiments described above, the description of the common parts is omitted, and only different points will be described. .
[0085]
In the present embodiment, switching of the pen down and pen up operation modes of the coordinate input pen 4 and switching of the absolute coordinate and relative coordinate output modes, which were not described in the first and second embodiments, are shown in the table of FIG. As shown in FIG. 5, the operation is performed according to the operation of the pen tip switch 41 and the pen side switches 42a and 42b of the coordinate input pen 4 and the detected x, y, and z coordinate values.
[0086]
First, switching between pen-down and pen-up operation modes will be described. On the display screen of the display 6, it is assumed that writing input of characters and figures is performed by inputting coordinates in a pen-down state, and a cursor is moved and an icon is clicked by inputting coordinates in a pen-up state. The switching is performed as follows according to the processing procedure shown in the flowchart of FIG. 10 according to the operation of the pen tip switch 41 and the pen side switches 42a and 42b of the coordinate input pen 4. Hereinafter, “switch” is abbreviated as “SW”.
[0087]
In the processing procedure of FIG. 10, after the processing is started (step S401), the pen point SW41 is turned on when the operator holds the coordinate input pen 4 and presses the display screen (coordinate input surface) (step S402). The control circuit of the drive circuit 45 determines that the pen is in a down state, drives the sound wave generation source 43 at a predetermined cycle so that the sound wave is emitted into the air, and notifies the arithmetic control circuit 1 that the pen is in the down state. (Step S406).
[0088]
As the notification method, for example, information on the pen-down state is transmitted by superimposing it on a start signal as an optical signal emitted from the light emitting means 44 and detected by the control signal detection circuit 211 so that it can be detected. It is also possible to determine pen-up / pen-down by changing the frequency of the sound wave radiated from the sound wave generation source 43 and detecting it on the arithmetic control circuit 1 side.
[0089]
If the x and y coordinate values detected in the pen-down state are coordinate values in the display area (display screen area) (in the range of x <± Disp_X, y <± Disp_Y in FIG. 6), the micro of the arithmetic control circuit 1 The CPU 301a of the computer 301 outputs the coordinate value (see FIG. 9). As a result, the trajectory associated with the movement of the coordinate input pen 4 is output on the display screen in a relationship like a normal paper and a pencil.
[0090]
On the other hand, if the detected x and y coordinate values are outside the display area even though the pen tip SW 41 is on, for example, the operator unintentionally operates the pen tip SW 41 regardless of the writing input. In this case, coordinate output is prohibited. Similarly, since the state where the pen tip SW 41 is on is a state where the display screen (coordinate input surface) is pressed by the coordinate input pen 4, the Z-axis coordinate value detected at this time is substantially “0”. If it is not “0”, an erroneous operation by the operator is assumed, and in this case as well, coordinate output is prohibited (see FIG. 9).
[0091]
On the other hand, when the pen tip SW 41 is in the OFF state, the writing operation is not performed by pressing the coordinate input surface by the operator. However, it is extremely possible that a desired screen operation can be performed by moving the displayed cursor or double-clicking an icon, for example, near or away from the display screen, or outside the display screen (display area). The benefits are great.
[0092]
Therefore, if only one of the pen side SWs 42a and 42b is turned on in steps S403 to S405, the control circuit of the drive circuit 45 determines that the pen is up, drives the sound wave generation source 43 to generate a sound wave, and the cursor The calculation control circuit 1 is notified that it is in the pen-up state (step S407).
[0093]
In addition, when both the pen side SWs 42a and 42b are turned on in steps S403 to S405, the control circuit of the drive circuit 45 determines that the pen is in the pen-down state even if the pen tip SW 41 is not turned on, and drives the sound wave generation source 43. The sound wave is generated and the arithmetic control circuit 1 is notified that it is in the pen-down state (step S406).
[0094]
As described above, by operating the pen side SWs 42a and 42b, coordinates are input at a position away from the display screen of the display 6, and the cursor is moved (pen-up state) or written (pen-down state). In such a case (in the state where the pen 4 is not in direct contact with the display screen of the display 6 and the pen tip SW 41 is not turned on), the coordinates are displayed on the display screen of the display 6 or in the vicinity of the display screen. The specifications required for operation differ between an input operation and a coordinate input operation at a position relatively distant from the display screen or outside the display area.
[0095]
First, in the former case, by moving the coordinate input pen 4, for example, it is required to move the displayed cursor intuitively and directly to a desired position accurately. However, in the latter case, for example, in order to move the displayed cursor to a desired position, it is required to relatively move the cursor in accordance with the movement of the coordinate input pen. In other words, when the operator intends to give a presentation using a large display, the display information can be controlled or information (characters, figures) can be written by touching the screen directly (coordinate input). (Relationship between paper and pencil) When the information is simply pointed to, the operator does not go to the spot and point, but it is displayed at a remote location, in other words, from the listener side. It is preferable that desired screen control and addition of information can be performed in a state where the information being hidden is not hidden by the operator. In addition, considering this type of large input / output integrated system and considering a meeting that assumes a large number of participants, the operator controls the personal computer by touching the screen directly as described above. In addition, for example, conference participants who are listening to the presentation while looking at the screen can display the screen even at a position away from the screen so that they can display questions or evidence for objection. It can be said that it is a preferable form to be configured so that it can be operated or information can be extracted from the network as necessary.
[0096]
Therefore, in the present embodiment, in accordance with the detected coordinate values (x, y, z), an output mode 1 that outputs absolute coordinate values as output coordinate values shown in the table of FIG. ) Is output and the coordinate output mode is switched to the output mode 2, and in order to solve the above-described problems of the invention, the detected coordinate values are averaged (moving average) as in the second embodiment. .
[0097]
Details of the switching of the coordinate output mode and the averaging process will be described below with reference to FIG. FIG. 11 is a flowchart showing the processing procedure. A processing program corresponding to this processing procedure is stored in the ROM 301b of the microcomputer 301 and executed by the CPU 301a.
[0098]
In the process of FIG. 11, first, in step S501 where the process is started, an integer n indicating the number of samples of x, y, z coordinate values sequentially detected and stored as described later is initialized to zero.
[0099]
Next, in step S502, it is determined whether or not an effective sound wave detection signal and a start signal necessary for coordinate calculation are detected by each of the detection sensors 3a to 3d and the control signal detection circuit 211, and a valid signal is detected ( In the case where the coordinates can be calculated), in step S503, the integer n is incremented by “1” (in the first case, n = 1), and each of the detection sensors 3a˜3 as described above from the effective sound wave detection signal. Each of the distance between 3d and the sound wave generation source 43 is measured.
[0100]
Next, it is determined whether or not the integer n is 1 in step S504. If it is 1, the position coordinates of the sound wave generation source 43 are within the distance between the detection sensors 3a to 3d and the sound wave generation source 43 measured in step S503 in step S505. Based on the three distance information (for example, the longest distance information among the four distances is not used for calculation) based on the three distance information used in the calculation of the average value (number of samples of the coordinate value to be averaged) in the averaging process described above Set Kend. The setting method is performed based on the longest distance information among, for example, three effective distance information used for coordinate calculation, and the larger the value is (in other words, the distance between the coordinate input pen 4 and the detection sensor is The larger the value), the larger the value of the averaged sample number Kend is set. In the setting, for example, the value of the averaged sample number Kend is increased proportionally or exponentially according to the distance value.
[0101]
Next, in step S506, the position coordinate value (X, Y, Z) of the sound wave generation source 43 is calculated using the effective three distance information, and the nth coordinate value (Xn, Yn, Zn) of the number of samples is calculated. Store in the RAM 301c.
[0102]
Next, in step S507, it is determined whether or not the integer n is 1. If it is 1, the number n of samples calculated and stored in step S506 immediately before that is the first coordinate value (X1, Y1, Z1) is as follows. In order to use it for the determination of the coordinate output mode and the calculation of the difference value described later, it is again stored in the RAM 301c (step S508). In steps S509 and S510, a coordinate output mode is determined based on the coordinate values.
[0103]
Here, the coordinate system of the coordinate input device is defined as shown in FIG. 6, the display screen of the display 6 is the XY plane (Z = 0), and the vertical direction is the Z axis. In step S509, the stored Z axis is stored. Is compared with a predetermined value (for example, a value corresponding to 1 m if the distance is 1 m). If it is smaller than the predetermined value, the X-axis coordinate value X1 and Y-axis coordinate value Y1 stored in step S510 are the coordinate values in the display area (display screen area) of the display 6 (in FIG. 6, x <± Disp_X, y If it is within the display area, the coordinate output mode is set to “output mode 1”.
[0104]
If the coordinate value Z1 is greater than or equal to the predetermined value in step S509, or if the coordinate values X1 and Y1 are coordinate values outside the display area in step S510, the coordinate output mode is set to “output mode 2”.
[0105]
The flowchart of FIG. 11 does not show all the methods for setting the operation mode described above with reference to FIG. 9, but starts the operation (on / off) information of the pen tip SW 41 of the coordinate input pen 4, for example. If it is superimposed on an optical signal that is a signal and demodulated and detected as a control signal by the control signal detection circuit 211, the operation information of the pen tip SW 41 can be used to increase the reliability of coordinate calculation. That is, in the state where the pen tip SW41 is turned on, it is normal that the pen tip SW41 is turned on by pressing the display screen which is the coordinate input surface. If the detected value of Z is not Z = 0, it is possible to cancel the output of the detected coordinate value as if the coordinate input was performed by some misoperation, and it is more reliable in terms of preventing malfunction. Is obtained (see FIG. 9).
[0106]
The state of “output mode 1” is a state in which the operator moves the coordinate input pen 4 relatively close to the display screen of the display 6 and operates the coordinate input pen 4 within the display area of the display 6. Accordingly, the display information is controlled by moving the cursor displayed on the display 6 or writing information such as characters and figures.
[0107]
On the other hand, the state of “output mode 2” is, for example, that the operator is outside the display area in the vicinity of the display screen (for example, next to the display 6) and controls the display contents without interrupting the display information to the listener. Since it is possible to assume a state where a presentation is being performed or a display content is controlled by remote operation at a position away from the display 6, the cursor can be moved relatively by the operation of the coordinate input pen 4. To do. Explaining this “relative” method of moving the cursor, at least the X-axis and Y-axis values of the detected coordinate values are calculated as difference values from the previously stored coordinate values (X1, Y1). Configure to do. That is, the detected coordinate value is “output mode 1”.
Detected coordinate value (Xn, Yn, Zn) → Stored coordinate value (Xn, Yn, Zn)
For “Output Mode 2”,
Detected coordinate value (Xn, Yn, Zn) → Stored coordinate value (Xn-X1, Yn-Y1, Zn-Z1)
Is processed as
[0108]
Next, in step S513, it is determined whether or not the value of the integer n matches the value of the average sample number Kend set in step S505. If not, coordinate detection is continuously performed in step S516. Is determined in exactly the same manner as described in step S108 of FIG. 7 of the first embodiment. If coordinate detection is continuously performed, the process returns to step S503. As long as coordinate detection is continuously performed, the processes of steps S503 to S513 and S516 are performed until the integer n reaches the averaged sample number Kend in step S513. repeat. By repeating this, coordinate values (absolute coordinate values in the output mode 1 and difference values in the output mode 2) are sequentially calculated and stored in the RAM 301c.
[0109]
If the integer n coincides with the averaged sample number Kend, in step S514, the coordinate values of the averaged sample number Kend detected and stored in the series of operations so far (absolute coordinates in the output mode 1). Value, the difference value in output mode 2) is calculated, and the X-axis coordinate and Y-axis coordinate values are output to the external device, etc. (Of course, the Z-axis coordinate average value is output to the external device, etc.) However, depending on the application, there may be an output form of only X-axis coordinates or Y-axis coordinates). Information indicating whether the coordinate value output here is an absolute coordinate value according to “output mode 1” or a difference value according to “output mode 2” may be output together with the coordinate value.
[0110]
Next, in step S515, for each of the X, Y, Z coordinate values (absolute coordinate values in output mode 1 and difference values in output mode 2) for each of the averaged sample numbers Kend stored in the previous operation. After erasing the first (oldest) samples X1, Y1, and Z1, the remaining samples Xn are shifted to Xn-1, Yn to Yn-1, and Zn to Zn-1 and stored again. For example, if the average sample number Kend is 3, X2 is stored as X1 and X3 is stored as X2. Also, the sample number n is decremented by “1”.
[0111]
Thereafter, the process proceeds to step S516, where it is confirmed whether or not the coordinates are continuously detected as described above. If the coordinates are continuously detected, the process returns to step S503, and the processes after step S503 are repeated.
[0112]
On the other hand, if the coordinate detection is not continuously performed in step S516, that is, if the continuous coordinate input operation is completed, the stored coordinate value and averaged sample number Kend are all reset and processed. After that, the process returns to step S501 to initialize the integer n, and in step S502, a standby state is waited for detection of a valid signal.
[0113]
As described above, in the present embodiment, the coordinate output mode is switched based on the detected coordinate value, and the detected coordinate value is averaged. The same effect as in the first and second embodiments can be obtained by the averaging process. That is, it is possible to compensate for a decrease in coordinate detection resolution accompanying an increase in measurement distance for coordinate detection, and when the position of the cursor is controlled with the coordinate input pen 4 from a position away from the display screen, the distance increases. Cursor fluctuation can be suppressed.
[0114]
Now, let us consider a case where the coordinate value Z1 is larger than a predetermined value set in advance in step S509. This state means that the coordinate input pen 4 is at a position away from the display screen of the display 6 as the coordinate input surface in the Z-axis direction. That is, it can be assumed that the operator who is presenting is at a position away from the display 6 or that the coordinate input is performed by the listener who is listening to the presentation. In other words, it can be said that the display information is controlled by remote operation or characters, figures, etc. are being added.
[0115]
Considering the state of being away from the display screen of the display 6, when the distance is relatively small (proximity input), the distance between the display screen and the coordinate input pen 4 in the Z-axis direction is a relatively small value. Yes, by moving the coordinate input pen 4, for example, the displayed cursor can be moved intuitively and directly to a desired position. Of course, the displacement of the cursor with respect to the desired position is larger than that when the input is directly made on the display screen (the pen tip SW 41 is in the on state), but it can be said to be a sufficiently practical range.
[0116]
However, as the distance from the display screen of the display 6 increases (Z coordinate value increases), the displacement of the cursor with respect to the desired position increases, and the desired position cannot be pointed directly and intuitively. In other words, when the cursor is to be moved at a distant position, the coordinate input pen 4 is turned on by turning on the pen side SWs 42a to 42b, and the coordinates are input. The position of the base cursor is different from the above-described desired position, and the operator can move the cursor to a desired position by moving the coordinate input pen 4 while visually recognizing the position of the cursor. .
[0117]
In other words, in the case of remote input (operation of inputting coordinates at a position away from the display 6 and moving the cursor, for example), the operator's brain performs a correction operation based on visual information by the operator (coordinate input pen 4 It is difficult to point the desired position directly by repeating the loop.
[0118]
As described above, when performing some remote input operation on the image information (image information having a coordinate system on the XY plane) displayed on the display 6, the operator tries to perform a series of coordinate inputs. The coordinate value of the first point at that time and the coordinate value of the image information cannot be matched. For example, a laser pointer is widely used as a tool for indicating a display image displayed by OHP or the like. However, the first point at the time of laser emission is instructed without knowing where to indicate. Obviously, it is possible to irradiate the laser to a desired position by performing a position correcting operation while observing the point position.
[0119]
Therefore, in the present embodiment, when the Z coordinate value is greater than or equal to the predetermined value in step S509 (remote input), the first effective coordinate value is stored as the predetermined coordinate value (X1, Y1, Z1) (this The position of the cursor displayed on the display screen does not move), and the movement direction of the pen 4 is obtained by sequentially outputting the difference value as the coordinate value along with the movement of the coordinate input pen 4 during the continuous input period. By moving the cursor by the amount of movement, it is configured to achieve excellent operability even in remote operation.
[0120]
FIG. 12 shows the respective output ranges in the coordinate output mode that are switched by the processing of the flowchart of FIG. 11 in the display range of the display 6 and the effective region of coordinate input. When the detected x and y coordinates are located in the display area relatively close to the display 6, absolute coordinates that can be input directly are output (output mode 1), while the listener's field of view is blocked. When remote control is performed on the side of the display 6 that is not present or away from the display 6, the relative coordinates are output (output mode 2).
[0121]
Considering the case of remote control, when you enter coordinates directly by touching the screen directly, considering that it is a large display, if you try to move the cursor from edge to edge, Accompanying body movement. However, in the case of remote control, for example, it is normal for a questioner to stand up and ask a question on the spot (necessary to move if there are a lot of listeners). It is desirable to be able to point to the entire area. The configuration of the present embodiment also solves this problem. This will be described below with reference to FIG.
[0122]
In the relative coordinate (difference value) output range shown in FIG. 12, a scene is assumed in which an operator is going to give a presentation to a large number of listeners using the display 6 having a large screen. As shown in FIG. 13A, when trying to move the cursor position from the position (1) to the position (3), conventionally, the coordinate input pen 4 is moved to the position (3). If coordinate input is performed at that position, the cursor moves from position (1) to position (3) (in this case, the operator is at a position where he can point to position (3)). However, after working at the position (1) (the operator is in the vicinity of the position (1)), when trying to move to the position (3), the operator moves across the screen. Therefore, for many listeners, the field of view is obstructed, which hinders understanding of the content of the presentation. Especially when the large display is a front projection, an OHP (projection type display device) or the like, the image is greatly distorted.
[0123]
On the other hand, in the configuration of the present embodiment, it is assumed that the operator is on the side of the display 6 and the cursor is at the position (1). When the operator holds the coordinate input pen 4 at the position A and turns on at least one of the pen side SWs 42a and 42b (hereinafter denoted by reference numeral 42), sound waves are emitted from the coordinate input pen 4 to input the coordinates. The position coordinates of the pen 4 are detected. At this time, since the coordinate input pen 4 is outside the display area of the display screen of the display 6 or at a position away from the display 6 (Z> predetermined value), the position coordinates detected first are stored (FIG. 11). In step S508), the cursor is not moved from the position {circle around (1)}. Subsequently, the operator moves the coordinate input pen 4 to the position B while operating the pen side SW 42 to turn on and continuously input coordinates, and then turns the pen side SW 42 off. Then, as the operator moves the coordinate input pen 4 from position A to position B, the cursor moves from position (1) to position (2) according to the moving direction and distance. . Further, after the operator moves the coordinate input pen 4 from the position B to the position C with the pen side SW 42 turned off (there is no coordinate input at this time, the cursor does not move at the position {circle around (2)}). If the pen side SW 42 is turned on at the position C and the coordinate input pen 4 is moved to the position D, a sound wave is generated from the position C and the first detected coordinate value is stored again (step S508). As the cursor moves by the difference between the detected coordinate value and the stored coordinate value, and the operator moves the coordinate input pen 4 (moving from point C to D), its moving direction and moving distance Thus, the cursor moves from the position (2) to the position (3).
[0124]
As described above, even if the operator is at a position away from the display screen of the display 6 that is the coordinate input surface, or at a position outside the display area, the operator can smoothly perform a desired operation from the current cursor position. In addition to being able to move the cursor to the position, during the series of coordinate input, the movement amount of the coordinate input pen in the X direction and the movement amount in the Y direction are Since there is a one-to-one correspondence with the amount of movement, characters and figures can be input.
[0125]
A case of inputting characters and figures will be described with reference to FIG. First, the coordinate input pen 4 is moved in a pen-up state in which only one of the pen side switches 42a and 42b is turned on, and the cursor is moved from the position {circle around (1)} to a desired position {circle around (2)}. Both the side SWs 42a and 42b are turned on to bring them into a pen-down state. By moving the coordinate input pen 4, the cursor is moved from the position (2) to the position (3), so that the locus according to the moving direction and the moving amount is obtained. Remains on the screen. Thereafter, one of the pen side switches 42a and 42b is turned off (the other one is still on and the state where the coordinates are continuously detected is maintained; the pen-up state), and the coordinate input pen 4 After moving the cursor from the position (3) to the desired position (4) by moving, the pen side SW that has been turned off is turned on again to bring the cursor down by moving the coordinate input pen 4 in the pen down state. If the position is moved from position (5) to position (5), the movement locus is input again. If both the pen side switches 42a and 42b are turned off at the position {circle over (5)}, the coordinate input is completed, and the locus of the character “I” is written.
[0126]
Here, the operator needs to move to the first position {circle around (2)} by moving the coordinate input pen 4 while visually recognizing the cursor. Character input can be performed by operating the absolute movement amount of the coordinate input pen 4, that is, intuitive hand and arm operation, without visual recognition. In other words, by using the first valid coordinate value during the continuous input period as a reference, the coordinates output during the continuous period become relative, but from the viewpoint of the operator, the amount of movement of the cursor during that period The hand and arm movements correspond to each other, and characters can be input by an intuitive input operation as if there is a coordinate input surface in the space.
[0127]
In this way, the operator can control the display information by natural movements and input information such as characters and figures by hand, and for many listeners, the display information is not obstructed. It is possible to efficiently understand the contents intended by the speaker who is the operator.
[0128]
Furthermore, in the present embodiment, in consideration of the usability of a system having a large screen, the mode for outputting absolute coordinates and the mode for outputting relative coordinates are automatically switched depending on the calculated coordinate values. It is possible to provide an excellent operating environment in which an operation (for example, switching the output mode of the coordinate input device by a switch unit or the like) is not required and the user can concentrate on the presentation.
[0129]
In the present embodiment, the relative coordinate is output, and the coordinate values (X1, Y1, Z1) serving as a reference for obtaining the difference from the detected coordinate value are first validated during the continuous input period. It is defined as a coordinate value. The reason for this will be described in detail below.
[0130]
It is easy for the operator to recognize the boundary of the display area in the vicinity of the display area, but this recognition becomes ambiguous as the distance from the display area increases. Furthermore, the numerical value of the predetermined value in the Z-axis direction in step S509 of FIG. 11 may be a numerical value that can be set by the operator, but even if the numerical value is recognized, the Z-axis by the predetermined value It is difficult to distinguish the actual boundaries of direction. On the other hand, by first inputting coordinates, the operator recognizes whether the output is performed in the form of absolute coordinates or the form of relative coordinates. For example, the coordinate input pen 4 It can be easily understood by the relationship between the position of the cursor and the cursor position. However, for example, when the operation is performed near the boundary where the output form is changed, if the mode switching operation occurs frequently, the output form is frequently changed, which makes it difficult for the operator to handle.
[0131]
Therefore, in this embodiment, the period of the start signal radiated from the coordinate input pen 4 is monitored to determine whether coordinate input is continuously performed, and the coordinate value that is first effective during the continuous input period. Is the reference coordinate value, and during the continuous input period, the difference between the coordinate value calculated after that and the reference coordinate value is output, so as long as one of the penside SWs 42a and 42b is on. Since this reference coordinate is held, even if it is a coordinate input operation near the switching boundary, the coordinate system for the operator and whether absolute or relative are fixed during the continuous coordinate input period, A coordinate input device with good operability can be configured.
[0132]
In other words, the operator can know the coordinate output form by first inputting one point of coordinates, and the mode is fixed while the coordinate input operation is performed continuously thereafter. Thereafter, the operator does not need to be aware of the boundary for mode switching.
[0133]
In this embodiment, the coordinate input device may output coordinate mode information (information indicating whether the coordinate is absolute or relative) together with the coordinate value to an external device or the like. Assume that only absolute coordinate values are output, and the host device that receives the output result, for example, the personal computer side receives the received coordinate values and the timing of receiving the coordinate values (determines whether coordinate input is being performed continuously) May be configured to perform processing similar to the coordinate output mode switching and averaging processing described in FIG.
[0134]
In the present embodiment, whether to output absolute coordinates or relative coordinates is determined based on the detected coordinate value and the distance in the Z-axis direction from the display 6 and the display area of the display 6. Judgment by whether or not. Therefore, it is preferable to be able to set which range the display area is in the coordinate system of the coordinate input device. In particular, when a front projector is used for the display 6, the display size is not always constant in consideration of the different installation methods for each conference (the display size of the front projector depends on the projection distance). A means for setting the display area is essential. Further, even in a system having a fixed display screen (for example, a rear projector, a plasma display, etc.), the coordinate system of the coordinate input device and the display 6 is an adjustment process that is disadvantageous in cost at the time of assembly. It is necessary, and it has a great manufacturing advantage that the display area can be set after the coordinate input device and the display 6 are combined. Further, as described above, if the output of the coordinate input device is only absolute coordinates, and the method in which, for example, a personal computer that receives the output determines the operation mode, the display 6 is still fixed. Since it is not limited, a means for informing the personal computer of the display area is required.
[0135]
FIG. 14 is a flowchart showing a processing procedure for setting a display area in view of this point. A control program for performing this processing is stored in the ROM 301b of the microcomputer 301 and executed by the CPU 301a.
[0136]
In performing the processing of FIG. 14, the operator designates each of the four corner positions of the rectangular display area (display screen) of the display 6 with the coordinate input pen 4 and inputs the coordinates of the four corner positions. .
[0137]
On the other hand, in the process of FIG. 14, the variable cont is first set to 0 (step S601), the variable cont is incremented (step S602), and then an effective sound wave signal and start signal necessary for coordinate detection are used. Is detected (step S603). When a valid signal is detected, the coordinate values Xcont and Ycont of the indicated position of the coordinate input pen 4 (any one of the four corners at the position of the sound wave generation source 43) are calculated based on the detected signal, and the RAM 301c is calculated. (Step S604).
[0138]
Next, it is confirmed whether the variable cont has become larger than 4 (step S605), and the processing of steps S602 to S605 is repeated a total of 4 times until it becomes so.
[0139]
After detecting and storing the respective coordinates of the four corner positions of the display area in this way, ± Disp_X, Y in the X-axis direction with respect to the origin O of the coordinate system shown in FIG. A display area (display screen area of the display 6) indicated by ± Disp_Y in the axial direction is calculated (step S606). Here, for example, a value obtained by averaging the x coordinate value of the upper left corner and the x coordinate value of the lower left corner is defined as a boundary value in the left x direction, or a quadrangular region connecting the four corners is defined, It is a conditional expression that determines the coordinate output form.
[0140]
Here, the display area is derived by detecting the coordinates of the four corner positions of the display area. However, the present invention is not limited to this. For example, the coordinates of the three positions of the four corners are used. The coordinate input pen 4 may trace the four sides of the display area to detect the coordinate values of the four sides, and set the display area from the information.
[0141]
By the way, considering the usability of the coordinate input device, when the operator moves the cursor on the screen by moving the coordinate input pen in the pen-up state, output mode 2 at a position away from the display screen of the display 6, the operator As the distance of the display screen increases, it is preferable that the cursor can be moved greatly by a slight movement of the coordinate input pen 4. Considering this point, in such a case, as the absolute coordinate value of the detected z-coordinate increases, or the longest distance among the measurement distances between the pen 4 and the detection sensors 3a to 3d used for coordinate calculation increases. The detected relative coordinate values (difference values) of x and y may be enlarged and output with a larger enlargement ratio.
[0142]
In this embodiment, the moving averaging process similar to that of the second embodiment is performed. However, a simple averaging process similar to that of the first embodiment may be performed. In that case, as in the first embodiment, the coordinate sampling rate is substantially reduced by the averaging process, but there is no problem in terms of user convenience for the same reason as described in the first embodiment.
[0143]
[Other Embodiments]
In the first to third embodiments described above, as a method of averaging the detected coordinate values, the coordinate values continuously detected are simply arithmetically averaged, or the arithmetic average is a moving average. However, as another method, averaging is performed by weighting the coordinate value of the sample (for example, increasing the weight of the coordinate value detected more recently to increase the influence of the latest coordinate value). It may be.
[0144]
In the first to third embodiments, the detected coordinate values are averaged as the detected coordinate value averaging process. However, the coordinate input device averages the measurement parameters for calculating the coordinates. As a result, the coordinate values may be averaged as a result. That is, in order to calculate the coordinates, the distance from the sound wave generation source 43 to the detection sensors 3a to 3d is first measured. Therefore, the distance corresponding to the number of averaged samples is measured, the average distance is calculated, and the average is calculated. The coordinate value may be calculated using the distance. Moreover, since the arrival time of the sound wave from the sound wave generation source 43 to the detection sensors 3a to 3d is measured, the arrival time for the number of averaged samples is measured, and the average arrival time is calculated. The coordinate value may be calculated using the arrival time.
[0145]
Moreover, although the coordinate input device of the 1st-3rd embodiment was a thing of the aerial sound wave system, it is not restricted to this, The signal transmitted from a signal transmission source is received for every predetermined period by several receiving means. In the case of a coordinate input device that measures each distance from a signal transmission source to a plurality of receiving means and detects the coordinates of the position of the signal transmission source based on each of the measured distances, generally, as the measurement distance increases Since the distance measurement resolution is reduced, it is possible to compensate for the decrease in the coordinate detection resolution accompanying the increase in the measurement distance by applying the detection coordinate value averaging process or the measured distance averaging process according to the present invention. it can.
[0146]
The coordinate input devices of the first to third embodiments can detect the three-dimensional coordinates of x, y, and z. However, the present invention is not limited to this, and only two-dimensional coordinates or only one-dimensional coordinates can be detected. Even in a coordinate input device that can be detected, it is possible to compensate for a decrease in coordinate detection resolution due to an increase in measurement distance by applying the detected coordinate value averaging process or the measured distance averaging process according to the present invention. Can do.
[0147]
By the way, in the configuration of the first to third embodiments, the movement of the coordinate input pen 4 is mainly performed considering that it is mainly used for writing characters and figures in the immediate vicinity of the display screen of the display 6. Performed by finger and wrist movements. On the other hand, since the operation at a position away from the screen is used to indicate a desired position on the display screen, the movement of the coordinate input pen 4 changes the movement of the arm, finger, wrist, and the direction of the body. For example, it is desirable that the displayed cursor can be moved greatly immediately. That is, it is usual that the moving speed of the cursor according to the instruction of the coordinate input pen 4 is faster in the distance from the screen than in the immediate vicinity of the screen.
[0148]
In this regard, in the coordinate input device that detects the position coordinates of the coordinate input pen 4 every predetermined period as in the first to third embodiments, the “predetermined period” and the detected coordinate value or the change in the measurement distance Thus, the moving speed of the coordinate input pen 4 can be detected.
[0149]
Therefore, when coordinates are detected, for example, if “coordinates with an abnormally fast moving speed of the coordinate input pen 4 are detected even though the screen is closest to the screen”, it is determined that an erroneous detection of the coordinate values has been performed. can do. Focusing on this point, regarding the moving speed of the coordinate input pen 4, the maximum allowable moving speed is set based on the detected coordinate value or the measured value of the distance from the coordinate input pen 4 to the specific detection sensor 3. It can be determined that coordinate values detected at a speed exceeding the moving speed are erroneously detected coordinates. For example, the distance from the coordinate input pen 4 to the specific detection sensor 3 at a certain detection time point is compared with the distance from the coordinate input pen 4 to the detection sensor at the next detection time point, and the difference value is the above-described allowable value. If it is larger than the distance defined by the maximum speed, it can be determined that a false detection has occurred during distance measurement. If it is determined that there is an erroneous detection, the coordinate value is invalidated, so that a highly reliable coordinate input device can be configured.
[0150]
【The invention's effect】
  As is clear from the above description, according to the present invention,By setting so that the number of samples for calculating the average value of coordinate values increases as the coordinate indicator moves away from the display screen, even if the coordinate indicator is away from the display screen, the fluctuation of the indication Suppressing growthIt is possible,It is possible to provide an excellent coordinate input device that is sufficiently considered in operability and easy to use. Furthermore, when the detection of the continuous coordinate values is interrupted, the process for calculating the average value is terminated, so that an average value with low reliability is prevented from being output.An excellent effect that it can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an overall configuration of a coordinate input device according to an embodiment of the present invention.
FIG. 2 is a side view and a rear view of a coordinate input pen of the apparatus.
FIG. 3 is a timing chart illustrating signal processing related to coordinate detection of the apparatus.
FIG. 4 is a block diagram showing a configuration of a signal waveform detection circuit of the same device.
FIG. 5 is a block diagram showing a configuration of an arithmetic control circuit of the same device.
FIG. 6 is an explanatory diagram showing a coordinate system of the apparatus.
FIG. 7 is a flowchart showing a procedure of detected coordinate value averaging processing in the first embodiment;
FIG. 8 is a flowchart showing a procedure of detected coordinate value averaging processing in the second embodiment;
FIG. 9 is a table showing a relationship between an operation mode and a coordinate output mode of a coordinate input pen, on / off of each switch of the coordinate input pen, a coordinate calculation value, and the like.
FIG. 10 is a flowchart showing a procedure for switching processing between a pen-up state and a pen-down state according to turning on / off of a coordinate input pen according to the third embodiment.
FIG. 11 is a flowchart showing a procedure of a coordinate output mode switching and an averaging process in the embodiment.
FIG. 12 is an explanatory diagram showing a relationship between a display range of the display, an absolute coordinate output range, and a relative coordinate output range in the same embodiment;
FIG. 13 is an explanatory diagram of a cursor movement operation and a character writing input operation by the coordinate input pen according to the embodiment.
FIG. 14 is a flowchart showing a procedure of display range setting processing in the embodiment;
FIG. 15 is a graph showing the relationship between the irradiation distance of the laser pointer and the fluctuation width of the bright spot (indicating point) and the relationship between the irradiation distance and the hand shake angle holding the laser pointer.
FIG. 16 is a graph showing the relationship between the measurement distance and the measurement resolution for coordinate detection in the aerial acoustic wave type coordinate input device.
[Explanation of symbols]
1 Operation control circuit
2 Signal waveform detection circuit
3a-3d detection sensor
4 Coordinate input pen
5 Light receiving element
6 Display
7 Display drive circuit
41 nib switch
42a, 42b Penside switch
43 Sound wave source
210 Envelope detection circuit
206 Second order differentiation circuit
207 Tg signal detection circuit
301 Microcomputer
301a CPU
301b ROM
303 timer
304a to 304d latch circuit

Claims (3)

The display screen in which the coordinate value in the horizontal direction and the vertical direction of the display screen and the coordinate value in the direction orthogonal to the display screen, which are instructed by the coordinate pointing tool, are continuously detected and detected continuously. A coordinate input device that outputs an average value of coordinate values in the horizontal and vertical directions of
Based on the coordinate value first detected in the detection of the continuous coordinate value, so that the number of samples for calculating the average value increases as the coordinate indicator moves away from the display screen, Setting means for setting the number of samples for calculating the average value;
When the coordinate value of the number of samples calculated based on the coordinate value detected first in the detection of the continuous coordinate value is continuously detected, the horizontal direction of the display screen detected continuously And an output means for outputting an average value of coordinate values in the vertical direction,
When the detection of the continuous coordinate value is interrupted before the coordinate value of the number of samples calculated based on the coordinate value detected first in the detection of the continuous coordinate value is continuously detected, A coordinate input device comprising: ending means for ending processing for calculating an average value of coordinate values in a horizontal direction and a vertical direction of a display screen . The display screen in which the coordinate value in the horizontal direction and the vertical direction of the display screen and the coordinate value in the direction orthogonal to the display screen, which are instructed by the coordinate pointing tool, are continuously detected and detected continuously. A coordinate value output method for outputting an average value of coordinate values in the horizontal direction and the vertical direction of
Based on the coordinate value first detected in the detection of the continuous coordinate value, so that the number of samples for calculating the average value increases as the coordinate indicator moves away from the display screen, Set the number of samples to calculate the average value,
When the coordinate value of the number of samples calculated based on the coordinate value detected first in the detection of the continuous coordinate value is continuously detected, the horizontal direction of the display screen detected continuously And the average value of the coordinate values in the vertical direction,
When the detection of the continuous coordinate value is interrupted before the coordinate value of the number of samples calculated based on the coordinate value detected first in the detection of the continuous coordinate value is continuously detected, A coordinate value output method comprising: ending processing for calculating an average value of coordinate values in a horizontal direction and a vertical direction of a display screen. The display screen in which the coordinate value in the horizontal direction and the vertical direction of the display screen and the coordinate value in the direction orthogonal to the display screen, which are instructed by the coordinate pointing tool, are continuously detected and detected continuously. A program for causing a computer to execute a coordinate value output procedure for outputting an average value of coordinate values in the horizontal direction and the vertical direction of
Based on the coordinate value first detected in the detection of the continuous coordinate value, so that the number of samples for calculating the average value increases as the coordinate indicator moves away from the display screen, A procedure for setting the number of samples for calculating the average value;
When the coordinate value of the number of samples calculated based on the coordinate value detected first in the detection of the continuous coordinate value is continuously detected, the horizontal direction of the display screen detected continuously And a procedure for outputting the average value of the coordinate values in the vertical direction,
When the detection of the continuous coordinate value is interrupted before the coordinate value of the number of samples calculated based on the coordinate value detected first in the detection of the continuous coordinate value is continuously detected, A program for causing a computer to execute a procedure for ending a process for calculating an average value of coordinate values in the horizontal and vertical directions of a display screen .

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