JP3814486B2 - Inkjet recording method and apparatus - Google Patents

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となる。
【００６１】
同様に、第２グループのノズルからのインク滴３００２が第３グループのノズルからのインク滴３００３によって受ける力を考える。インク滴３００２とインク滴３００３との水平距離は、（Ｎ／２−１）・Ｐと表せるものと（Ｎ／２＋１）・Ｐと表せるものとの２つがある。これらそれぞれについて、静電界中で受ける力の水平方向成分Ｆ2x，Ｆ3xを、Ｆ1xと同様に求めると、
Ｆ2x＝［αＰ・｛（Ｎ／２）−１｝］√{Ｖ²・ｔd²＋{（Ｎ／２）−１}²×Ｐ²］
Ｆ3x＝［αＰ・｛（Ｎ／２）＋１｝］√［Ｖ²・ｔd²＋｛（Ｎ／２）＋１｝²×Ｐ²］
となる。これらＦ1x，Ｆ2x，Ｆ3xを比べると、Ｆ3xが最大となっている。
【００６２】
一方、同一グループのノズルからのインク滴の水平方向距離はＮ・Ｐで表せ、これらが静電電界中を飛翔中に互いに受ける力Ｆ0は、
Ｆ0＝α・Ｎ²・Ｐ²
となる。前述のＦ3xをＦ0以下にするための条件は、上記の式より
√［Ｖ²・ｔd²＋｛（Ｎ／２）＋１｝²×Ｐ²］≦２Ｎ²・Ｐ／（Ｎ＋２）
となる。
【００６３】
実際に、Ｖ＝１０［ｍ／Ｓ］，ｔd＝２８［μｓ］，Ｎ＝８，Ｐ＝４２．５×１０^-6［ｍ］として、Ｎ・Ｐ＞３００、
√［Ｖ²・ｔd²＋｛（Ｎ／２）＋１｝²×Ｐ²］≦２Ｎ²・Ｐ／（Ｎ＋２）
の両式を満たすような駆動方法を行ったところ、静電界によるインクの着弾位置ズレが１５μｍ以下に収まり、良好な記録品位が得られることが確認された。
【００６４】
このように実施の形態２によれば、前述の実施の形態１に記載した記録ヘッドを、静電吸着法を利用したインクジェット記録装置に搭載した際に、静電界によるインク滴の着弾位置ズレを極小にし、良好な記録を行うことができるインクジェット記録装置を提供するものである。
【００６５】
［実施の形態３］
図７は、本発明の実施の形態３を説明するための図である。実施の形態３は、記録ヘッドユニット２１００の複数のノズルを８つの時分割駆動のグループに分割している点および静電搬送による影響を考慮して同時駆動を行うノズル間隔を確定する点については、前述の実施の形態１と同様である。実施の形態１と実施の形態２との相違点は、記録ヘッドユニット２１００のノズルを更に第１〜７までの７つのブロックに分割し、同一グループに属する複数のノズルの駆動タイミングをさらに時分割した点にある。
【００６６】
図７に示すように、第１グループの第１ブロックに属するノズルからインク吐出を行い、約４μｓの遅延後、第１グループの第２ブロックのノズルからのインク吐出を行う。以下同様に、第１グループの第７ブロックまでのノズルを順次、それぞれ４μｓの遅延をもって駆動してインク吐出を行う。尚、各グループの選択は前述の信号ＥＡ*，ＥＢ*，ＥＣ*により行われ、各ブロックの選択は信号ＳＥＬ１〜ＳＥＬ７により行われる。
【００６７】
こうして第１グループのノズルによる記録が終了すると、次に、第２グループの第１ブロックのノズルによるインク吐出を行う。このように、同一グループに属する８９６個のノズルの駆動タイミングを７つに分割することにより、同時に駆動される熱エネルギー発生素子２００９の個数を更に“１２８”個にまで減少させることができる。その結果、単一の熱エネルギー発生素子２００９に瞬間的に流れる電流が約２００ｍＡであるから、瞬間的に流れる電流の合計を最大約２５．６Ａにまで低減化できる。
【００６８】
この場合の処理を図８のフローチャートで示す。尚、この実施の形態３のインクジェット記録装置の構成は前述の実施の形態１と同様であるため、その説明を省略する。また図８において、前述の図６のフローチャートと共通する部分は同じ符号を付して、その説明を省略する。
【００６９】
この実施の形態３では、ステップＳ３の後ステップＳ４−１で、第１ブロックを選択し（SEL=1,SEL2-7=0)、ステップＳ５で、信号ＥＡ*，ＥＢ*，ＥＣ*＝（１，１，１）として第１グループを選択する。そしてステップＳ６で，ＥＮＢ１〜ＥＮＢ２８を出力して発熱抵抗体を駆動した後、ステップＳ６−１で、ここでは４μｓ待機してステップＳ６−２に進む。ここでは第１グループの全ブロックによる記録処理が終了したかを調べ、終了していないときはステップＳ６−３に進み、次のブロックを選択するための選択信号ＳＥＬｉ（ｉ＝１〜７）を出力する。こうして第１グループのノズルによる記録が終了するとステップＳ６−２からステップＳ７に進み、前述したように１ライン（第１〜第８グループのノズルによる）の記録が終了したかを調べ、終了していないときはステップＳ８に、終了していればステップＳ１０に進むように動作する。
【００７０】
このように実施の形態３によれば、同一グループに属する複数のノズルを更に複数ブロックに分割し、ブロック単位で時分割駆動することにより、記録ヘッドに瞬間的に流れる最大電流値を減少させている。これにより、ヘッド電源及び電源用コンデンサ等にかかる負担を低減化し、より安定したインクの吐出を行うことができる。
【００７１】
［実施の形態４］
図１３乃至図１５は、本発明の実施の形態４に係るインクジェット記録ヘッドを説明するための図であり、図１３は実施の形態４に係るインクジェット記録ヘッドの模式的斜視図、図１４は、そのインクジェット記録ヘッドのインク吐出機構を模式的に示した断面図、図１５（ａ）は、そのインクジェット記録ヘッドの模式的上面図、図１５（ｂ）は図１５（ａ）のＡ−Ａ断面図、図１５（ｃ）は図１５（ａ）のＢ−Ｂ断面図である。
【００７２】
図１３に示す実施の形態４に係るインクジェット記録ヘッドは、記録素子基板２０１の中央付近の表面側にインクを吐出するための吐出口２０２が複数開口しており、これら吐出口２０２から吐出されるインク滴によって記録を行うものである。
【００７３】
図１４および図１５（ａ）〜１５（ｃ）に示すように、記録素子基板２０１上には、各々の吐出口２０２に対応して加熱用ヒータ２０４が形成されており、これら加熱用ヒータ２０４に通電加熱してインクを発泡させ、その運動エネルギーで記録液であるインクを吐出させる。
【００７４】
加熱用ヒータ２０４からの配線は、各々、記録素子基板２０１上の駆動素子２０５の実装部に伸びており、ここに実装された駆動素子２０５に電気的に接続されている。駆動素子２０５は、異方性導電フィルムを介してＣＯＢ(chip on boad)の接続方法により、記録素子基板２０１に接続されている。また、駆動素子２０５には、トランジスタ回路の他にトランジスタを駆動するためのロジック回路が搭載されており、そのロジック回路を駆動する信号は、記録素子基板２０１を介してフレキシブルフィルム２０６に接続される。更に、このフレキシブルフィルム２０６は、ガラスエポキシ等の複合材料からなる回路基板２０７（図１５（ａ））に接続されている。この回路基板２０７には、外部から電気的信号を入力するための電気コネクタ２０８（図１５（ｂ））が搭載されている。
【００７５】
駆動素子２０５及びフレキシブルフィルム２０６の電気的接続部は、電極部が露出すると吐出口２０２から飛散した液滴もしくはシートより跳ね返ったインク等が電極に付着して、電極やその下地金属を腐食するため、該電極部は封止性、イオン遮断性に優れた不図示のシリコン樹脂封止剤により被覆され、封止されている。
【００７６】
また記録素子基板２０１の裏面側には、記録素子基板保持部材２１１及び支持部材２１２によって形成された、インクを保持するための共通液室２１０（図１５（ｃ））が、複数の吐出口２０２の配列長さとほぼ等しい長さで開口して形成されている。また記録素子基板２０１には、この裏面側のインクを表面側に供給するためのスリット２０３（図１５（ｃ））が設けられている。この共通液室２１０は、更にインク供給口２１５，２１６に連通しており、インク吐出時には、インクジェット記録ヘッド外部の不図示のインクタンクから、これら双方のインク供給口２１５，２１６を通じてインクの供給を受ける構成になっている。
【００７７】
このインクジェット記録ヘッドにインクを充填する際は、インク供給口（流入）２１５からインクを加圧流入させ、共通液室２１０内の空気を、主にインク供給口（流出）２１６から抜くことで、共通液室２１０内に気泡を残さないで充填することができる。インクが共通液室２１０内に完全にインクが充填されるまでこの動作は続けられ、その間、気泡が混入したインクがインク供給口（流出）２１６から排出されるが、このインクはインク供給口（流入）２１５の上流にある元の不図示のインクタンクに戻すという、インクを循環させるタイプのインク供給流路構成になっている。
【００７８】
図１６は、実施の形態４に係るインクジェット記録ヘッド基板の回路構成を示す図である。図において、各々の駆動トランジスタと、シフトレジスタおよびラッチが１対１に対応しない駆動ＩＣを用いた駆動回路の例を示している。
【００７９】
図示したように、駆動トランジスタ１６００におけるドライバの個数は１つのＩＣ当たり２５６個であり、それに対しシフトレジスタ１６０１及びラッチ１６０２は共に１６ビットである。画像データ(SI)は、シフトレジスタ１６０１にシリアルで順次転送され、１６ビットデータがシフトレジスタ１６０１に転送されて保持された後、この１６ビットデータはラッチ１６０２に格納される。この１６ビットラッチの各々の出力は、１６本の信号線に接続されており、外部から制御入力されるデコーダ１６０３の出力信号とＡＮＤ回路１６０４によりＡＮＤがとられている。更に、ＡＮＤ回路１６０４の出力信号とトランジスタを駆動するパルス幅を決定するＥＮＢ信号(ENB0,ENB1)との論理積がＡＮＤ回路１６０５により取られ、その出力信号でドライバ回路１６００が駆動される。
【００８０】
ここで実際に画像データを記録する際は、まず１６ビットのシフトレジスタ１６０１にシリアルで画像データを順次入力し、１６ビット分の画像データが転送されたところで、この画像データをラッチ回路１６０２にラッチする。次に、デコーダ１６０３に信号BE0*〜BE3*(*は負論理の信号を示す)を入力し、デコーダ１６０３の１番目のみをハイレベルにし、その他の出力をロウレベルにする（BE0*〜BE3*=1）。この状態でＥＮＢ信号を印加すると、１番目、１７番目、３３番目…のトランジスタ素子が駆動されて、それに対応するノズルからインクが吐出される。
【００８１】
次に、前述と同様に、信号BE0*〜BE3*を（1110）としてデコーダ１６０３の９番目の出力のみをハイレベル、その他の出力をロウレベルにする。そして同様にＥＮＢ信号を印加すると、９番目、２５番目、４１番目、…のトランジスタ素子が駆動されて、それに対応するノズルからインクが吐出される。以下、デコーダ１６０３に入力する信号BE0*〜BE3*を順次切換えることにより、例えば以下のような順番で各ノズルを駆動してインクを吐出させることができる。
【００８２】
１番、１７番、３３番、…
９番、２５番、４１番、…
２番、１８番、３４番、…
１０番、２６番、４２番、…
：
：
１６番、３２番、４８番、…
このように順次駆動することにより、前述の実施の形態と同様に本発明に適用できる。
【００８３】
本発明は、特にインクジェット記録方式の中でも、インク吐出を行わせるために利用されるエネルギーとして熱エネルギーを発生する手段（例えば電気熱変換体やレーザ光等）を備え、前記熱エネルギーによりインクの状態変化を生起させる方式のプリント装置について説明したが、例えば特公平６−６３５７号公報等に記載されているような圧電方式のインクジェット記録方式においても同様の効果が得られる。かかる方式によれば記録の高密度化、高精細化が達成できる。
【００８４】
その代表的な構成や原理については、例えば、米国特許第４７２３１２９号明細書、同第４７４０７９６号明細書に開示されている基本的な原理を用いて行うものが好ましい。この方式はいわゆるオンデマンド型、コンティニュアス型のいずれにも適用可能であるが、特に、オンデマンド型の場合には、液体（インク）が保持されているシートや液路に対応して配置されている電気熱変換体に、記録情報に対応していて核沸騰を越える急速な温度上昇を与える少なくとも１つの駆動信号を印加することによって、電気熱変換体に熱エネルギーを発生せしめ、記録ヘッドの熱作用面に膜沸騰を生じさせて、結果的にこの駆動信号に１対１で対応した液体（インク）内の気泡を形成できるので有効である。この気泡の成長、収縮により吐出用開口を介して液体（インク）を吐出させて、少なくとも１つの滴を形成する。この駆動信号をパルス形状をすると、即時適切に気泡の成長収縮が行われるので、特に応答性に優れた液体（インク）の吐出が達成でき、より好ましい。
【００８５】
このパルス形状の駆動信号としては、米国特許第４４６３３５９号明細書、同第４３４５２６２号明細書に記載されているようなものが適している。なお、上記熱作用面の温度上昇率に関する発明の米国特許第４３１３１２４号明細書に記載されている条件を採用すると、さらに優れた記録を行うことができる。
【００８６】
記録ヘッドの構成としては、上述の各明細書に開示されているような吐出口、液路、電気熱変換体の組み合わせ構成（直線状液流路または直角液流路）の他に熱作用面が屈曲する領域に配置されている構成を開示する米国特許第４５５８３３３号明細書、米国特許第４４５９６００号明細書を用いた構成も本発明に含まれるものである。加えて、複数の電気熱変換体に対して、共通するスロットを電気熱変換体の吐出部とする構成を開示する特開昭５９−１２３６７０号公報や熱エネルギーの圧力波を吸収する開孔を吐出部に対応させる構成を開示する特開昭５９−１３８４６１号公報に基づいた構成としても良い。
【００８７】
さらに、記録装置が記録できる最大記録媒体の幅に対応した長さに記録要素を配したフルラインタイプの記録ヘッドとしては、上述した明細書に開示されているような複数記録ヘッドの組み合わせによってその長さを満たす構成や、一体的に形成された１個の記録ヘッドとしての構成のいずれでもよい。
【００８８】
加えて、装置本体に装着されることで、装置本体との電気的な接続や装置本体からのインクの供給が可能になる交換自在のチップタイプの記録ヘッド、あるいは記録ヘッド自体に一体的にインクタンクが設けられたカートリッジタイプの記録ヘッドを用いてもよい。
【００８９】
また、本発明の記録装置の構成として設けられる、記録ヘッドに対しての回復手段、予備的な補助手段等を付加することは本発明の効果を一層安定にできるので好ましいものである。これらを具体的に挙げれば、記録ヘッドに対してのキャッピング手段、クリーニング手段、加圧あるいは吸引手段、電気熱変換体あるいはこれとは別の加熱素子あるいはこれらの組み合わせによる予備加熱手段、記録とは別の吐出を行う予備吐出モードを行うことも安定した記録を行うために有効である。
【００９０】
さらに加えて、本発明に係る記録装置の形態としては、コンピュータ等の情報処理機器の画像出力端末として一体または別体に設けられるものの他、リーダ等と組み合わせた複写装置、さらには送受信機能を有するファクシミリ装置の形態を取るものであっても良い。
【００９１】
なお、本発明は、複数の機器（例えばホストコンピュータ，インタフェイス機器，リーダ，プリンタなど）から構成されるシステムに適用しても、一つの機器からなる装置（例えば、複写機，ファクシミリ装置など）に適用してもよい。
【００９２】
また、本発明の目的は、前述した実施形態の機能を実現するソフトウェアのプログラムコードを記録した記憶媒体を、システムあるいは装置に供給し、そのシステムあるいは装置のコンピュータ（またはＣＰＵやＭＰＵ）が記憶媒体に格納されたプログラムコードを読出し実行することによっても達成される。
【００９３】
この場合、記憶媒体から読出されたプログラムコード自体が前述した実施形態の機能を実現することになり、そのプログラムコードを記憶した記憶媒体は本発明を構成することになる。
【００９４】
プログラムコードを供給するための記憶媒体としては、例えば、フロッピディスク，ハードディスク，光ディスク，光磁気ディスク，ＣＤ−ＲＯＭ，ＣＤ−Ｒ，磁気テープ，不揮発性のメモリカード，ＲＯＭなどを用いることができる。
【００９５】
また、コンピュータが読出したプログラムコードを実行することにより、前述した実施形態の機能が実現されるだけでなく、そのプログラムコードの指示に基づき、コンピュータ上で稼働しているＯＳ（オペレーティングシステム）などが実際の処理の一部または全部を行い、その処理によって前述した実施形態の機能が実現される場合も含まれる。
【００９６】
さらに、記憶媒体から読出されたプログラムコードが、コンピュータに挿入された機能拡張ボードやコンピュータに接続された機能拡張ユニットに備わるメモリに書込まれた後、そのプログラムコードの指示に基づき、その機能拡張ボードや機能拡張ユニットに備わるＣＰＵなどが実際の処理の一部または全部を行い、その処理によって前述した実施形態の機能が実現される場合も含まれる。
【００９７】
以上説明したように本実施の形態によれば、隣接するノズルから吐出されるインク滴による影響を無くして高品位の画像を記録できるという効果がある。
【００９８】
【発明の効果】
以上説明したように本発明によれば、記録シートを静電吸着法を用いて搬送する装置において生じる隣接する記録要素間の相互影響を無くして、高品位の画像を記録できる。
【００９９】
また本発明によれば、隣接する記録要素（ノズル）から吐出されるインク滴による影響をなくして、高品位の画像を記録できる。
【０１００】
又本発明によれば、隣接する記録要素（ノズル）から吐出されるインク滴による影響をなくすとともに、記録ヘッドの駆動用電源の容量の増大を防止できるという効果がある。
【０１０１】
又本発明によれば、記録ヘッドの記録要素を複数のグループに分けて時分割駆動し、現駆動タイミングにおいて、前の駆動タイミングでインクを吐出した記録要素で発生した圧力波による影響をなくすことができる。
【０１０２】
又本発明によれば、静電吸着法により被記録材を搬送する場合でも、隣接する記録要素（ノズル）から吐出されるインク滴による影響をなくして、高品位の画像を記録できるという効果がある。
【図面の簡単な説明】
【図１】（ａ）は本発明の実施の形態の記録ヘッドユニットを示す斜視図、（ｂ）はその記録ヘッド部分の拡大断面斜視図である。
【図２】本発明の実施の形態に係る記録ヘッドユニットの駆動回路図である。
【図３】本発明の実施の形態の駆動素子の回路図である。
【図４】本発明の実施の形態に係る記録ヘッドユニットの駆動順序を説明する模式図である。
【図５】本発明の実施の形態に係るインクジェット記録装置の構成を示すブロック図である。
【図６】本発明の実施の形態に係るインクジェット記録装置の制御部の制御処理を示すフローチャートである。
【図７】本発明の実施の形態における記録ヘッドユニットの駆動順序を説明する模式図である。
【図８】本発明の実施の形態に係るインクジェット記録装置の制御部の制御処理を示すフローチャートである。
【図９】本発明の実施の形態に係るインクジェット記録装置の模式的斜視図である。
【図１０】インクジェット記録装置によるドット位置のズレ量を説明する図である。
【図１１】本発明の実施の形態に係るインクジェット記録装置よるインクの飛翔状態を説明する図である。
【図１２】従来の記録ヘッドからのインク滴の飛翔状態を説明する模式図である。
【図１３】本発明の実施の形態４に係るインクジェット記録ヘッドの模式的斜視図である。
【図１４】本発明の実施の形態４に係るインクジェット記録ヘッドのインク吐出機構を模式的に示した断面図である。
【図１５】本発明の実施の形態４に係るインクジェット記録ヘッドを説明する図で、（ａ）は模式的上面図、（ｂ）は図１５（ａ）のＡ−Ａ断面図、（ｃ）は図１５（ａ）のＢ−Ｂ断面図である。
【図１６】本実施の形態に係るインクジェットヘッド基板の回路構成を示す図である。
【図１７】本発明の同時吐出ノズル間隔を変更を行うヘッドの等価回路を説明するための図である。
【図１８】、
【図１９】、
【図２０】、
【図２１】シート表面電位と同時駆動ノズル間隔の着弾ずれへの影響を示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording method and apparatus for recording an image by driving a plurality of recording elements according to an image signal and causing ink to fly on a recording material.
[0002]
[Prior art]
Conventionally, as a recording device that selectively drives a recording element in accordance with a recording signal input from an external device such as a host computer and performs recording on a recording material (hereinafter referred to as a recording sheet), a wire dot method, a thermal transfer method Inkjet type printer devices are known. In particular, an ink jet printer that mounts an ink jet head and discharges ink from an ink discharge port (nozzle) of the head for recording can record high-definition images, and the price of the device is low. Therefore, it has attracted particular attention in recent years and is being widely used in various fields. In particular, a recording head in which a plurality of recording elements each having an ink ejection port, an ink liquid path, and an ejection energy generating element are arranged at a fine pitch is arranged in a direction (main scanning direction) perpendicular to the arrangement direction (sub-scanning direction) of the plurality of recording elements. The demand for inkjet printers for color recording or gradation recording for recording an image by scanning a plurality of recording heads in the main scanning direction is increasing rapidly.
[0003]
In the above-described recording head, a heating resistor, which is an ejection energy generating element, is provided at a position corresponding to each nozzle, and heat energy is generated by flowing current through the heating resistor, and this thermal energy is used to respond. Recording is performed by discharging a liquid from the nozzle. Particularly in today's high demands for high density and high speed recording, it is common to record multiple lines in a single main scan of the recording head. Is used.
[0004]
[Problems to be solved by the invention]
When high-density and high-speed recording is performed in this way, the nozzles close to the position of the recording head are driven at very short time intervals, so the state of ink ejected from the nozzles is ejected from adjacent nozzles. It becomes easy to be influenced by the pressure wave by the ink. As a result, the amount of ink discharged from each nozzle, the ink discharge speed, and the like are not stable, and there is a problem in that the recorded image quality is lowered.
[0005]
Further, when the recording sheet is transported, if the recording sheet is attracted and transported by using an electrostatic adsorption method, each ink droplet flying from the recording head is required to reach the recording sheet as shown in FIG. Charged between. As a result, ink droplets flying in the vicinity repel each other, and the flight direction of the ink droplets interferes. As a result, the landing position of the ink droplet on the recording sheet is shifted, and there is a serious problem that the quality of the image recorded on the recording sheet is deteriorated.
[0006]
The present invention has been made in view of the above-described conventional example, and eliminates the mutual influence between adjacent recording elements that occurs in an apparatus that conveys a recording sheet using an electrostatic adsorption method, and can perform high-quality image recording. It is an object to provide a method and apparatus.
[0007]
Another object of the present invention is to provide an ink jet recording method and apparatus capable of recording a high-quality image without the influence of ink droplets ejected from adjacent recording elements (nozzles).
[0008]
It is another object of the present invention to provide an ink jet recording method and apparatus that eliminates the influence of ink droplets ejected from adjacent recording elements (nozzles) and prevents an increase in the capacity of a recording head driving power source. .
[0009]
Another object of the present invention is to divide the recording elements of the recording head into a plurality of groups and perform time-division driving so as to eliminate the influence of pressure waves generated by the recording elements that eject ink at the previous driving timing at the current driving timing. It is an object of the present invention to provide an ink jet recording method and apparatus.
[0010]
Another object of the present invention is to provide an ink jet recording method capable of recording a high-quality image without the influence of ink droplets ejected from adjacent recording elements (nozzles) even when a recording material is conveyed by an electrostatic adsorption method. And providing an apparatus.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the ink jet recording apparatus of the present invention has the following configuration. That is,
An inkjet recording apparatus that records an image by driving a recording element of a recording head according to an image signal and causing ink to fly to a recording material,
A first selection unit capable of dividing a plurality of recording elements of the recording head into a plurality of blocks with a plurality of continuous recording elements as a unit, and selecting a recording element for each block;
The plurality of blocksOf the recording elements arranged acrossA plurality of recording elements dispersed at a predetermined interval are set as one group, and a driving cycle is set as a plurality of groups.Number ofA second selection means for enabling each group to be selected in units of group periods divided by
The recording elements in the group selected by the second selection means are further selected in order by time-division in block units using the first selection means within the group period, and the image elements are selected in the selected recording elements. Drive means for energizing and driving in accordance with a signal.
[0016]
In order to achieve the above object, the ink jet recording method of the present invention comprises the following steps. That is,
An ink jet recording method for recording an image by driving a recording element of a recording head according to an image signal and causing ink to fly to a recording material,
Dividing a plurality of recording elements of the recording head into a plurality of blocks in units of a plurality of continuous recording elements, and selecting a recording element for each block unit; and
The plurality of blocksOf the recording elements arranged acrossA plurality of recording elements dispersed at a predetermined interval are set as one group, and a driving cycle is set as a plurality of groups.Number ofA second selection step in which each group can be selected in units of group periods divided by
The recording elements in the group selected by the second selection step are further selected in order by time-division in block units by the first selection step within the group period, and the selected recording elements are added to the image signal. And a driving step of driving by energizing accordingly.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0022]
[Embodiment 1]
FIG. 1A is an external perspective view of a so-called full-line type recording head unit 2100 in which recording elements such as nozzles are arranged in a recordable width according to an embodiment of the present invention, and FIG. FIG. 3 is an enlarged cross-sectional perspective view of a recording head portion of the embodiment.
[0023]
1A and 1B, a thermal energy generating element (heating resistor) 2009, which is one of the constituent elements of a recording element, is disposed on a recording element substrate 2001, and nozzles (inks) are disposed thereon. (Discharge port: recording element) 2010 and a top plate 2005 forming a liquid chamber 2008 are disposed. Further, a drive element 2004 for driving these thermal energy generating elements 2009 is mounted on the recording element substrate 2001, and heat is transmitted from the drive element 2004 through a wiring pattern (not shown) disposed on the recording element substrate 2001. Electric energy is supplied to the energy generating element 2009. The recording head having such a configuration is fixed on the base plate 2002 together with the printed circuit board 2003. Here, the recording head and the printed circuit board 2003 are electrically connected by wire bonding 2006. The printed circuit board 2003 is provided with an electrical connector 2007 for inputting an electrical signal from the outside. Ink used for recording is supplied to the liquid chamber 2008 through an ink tank (not shown) and an ink supply tube. At the time of recording, a driving signal corresponding to the recording signal input via the electrical connector 2007 is sent to the driving element 2004 through the wire bonding 2006. As a result, the thermal energy generating element 2009 is driven in accordance with the electrical pulse signal output from the driving element 2004, and ink droplets are ejected from the ink 2010 by foaming ink in the nozzle 2010.
[0024]
FIG. 2 is a diagram showing circuit wiring of the recording head unit 2100 of the present embodiment.
[0025]
In the present embodiment, 28 drive elements 2004 (IC1 to IC28) are used, and 256 drive elements 2004 are driven by one drive element 2004. These 28 drive elements 2004 are divided into 7 blocks in total of 4 (ICi to ICi + 3). A recording data signal (SI1 to SI7), a data signal transfer clock (CK), a latch signal (LT), an EA, EB, EC, and an EG signal (described later) are input to each block, and the drive belonging to each block. Each of the signals (SEL1 to SEL7) corresponding to the chip enable of the element 2004 is input for each block. In addition, signals (ENB1 to 28) for determining the pulse widths of electric pulses for driving the thermal energy generating element 2009, signals D1-A1 to A28, D1 to C1 to C28, and power supply lines VDD, L-GND, P- Although not shown in the figure, the GND is input to each drive element 2004 through each wiring.
[0026]
FIG. 3 is a block diagram showing a configuration of the drive element 2004 of the present embodiment.
[0027]
The data signal (SI) is sequentially transferred to and stored in the 256-bit shift register 301 in synchronization with the data transfer clock (SCKI: CK in FIG. 2). The 256-bit data held in the shift register 301 is sent to and stored in the 256-bit latch register 302 by a latch signal (LT *: * indicates a negative logic signal). The EA *, EB *, EC *, and EG * signals are all negative logic (low true) signals, and are input to the decoder 303 of 3-8 to perform the distributed drive eight times. The stored signal is selected in units of 8 blocks and output to the driver 304. The signal thus selected drives a transistor corresponding to the thermal energy generation element in accordance with an ENB signal (ENBI) that gives a pulse width for driving the thermal energy generation element 2009 to drive the thermal energy generation element 2009. Here, each of the EA *, EB *, and EC * signals is a 1-bit signal, which determines which of the outputs (terminals 1 to 8) of the decoder 303 is set to a high level, and the EG * signal is the decoder. This is a signal for enabling the output of 303.
[0028]
In the present embodiment, “7168” nozzles are arranged at a density of 600 dpi (42.5 μm intervals) in one recording head unit 2100 and are driven at a driving frequency of 4 KHz. The thermal energy generating element 2009 is an electric resistor having a size of about 20 μm × 80 μm, and its resistance value is about 55Ω. By applying a voltage pulse of about 10 to 12 V (pulse width of about 3 μs) to the thermal energy generating element 2009, the ink in the vicinity of the thermal energy generating element 2009 is heated and foamed, and the ink can be ejected from the nozzle. it can. At this time, the current instantaneously flowing through the single thermal energy generating element 2009 is about 200 mA. Further, the bubble of ink generated in the thermal energy generating element 2009 when the pulse signal is applied reaches its maximum foam volume about 12 μs after the pulse signal is applied to the thermal energy generating element 2009. After that, it was confirmed that the ink bubbles began to condense and disappeared about 25 μs after the pulse application.
[0029]
FIG. 4 is a diagram for explaining the ink ejection timing of the recording head unit 2100 of the present embodiment.
[0030]
In the first embodiment, all the nozzles (7168) arranged in the recording head unit 2100 are divided into 8 (= N) groups, and the above-described EA *, EB *, and EC * signals are used. Time-division driving is performed for each group. When recording, ink is first ejected from the 1st, 9, 17,..., 7162th (total 896) nozzles belonging to the first group. At this time, the instantaneous current flowing through the single thermal energy generating element 2009 is about 200 mA. Here, since a maximum of 896 thermal energy generating elements 2009 are simultaneously turned on, the total instantaneous current becomes a maximum of about 180A. Subsequently, ink is ejected from the 5th, 13th,..., 7165th nozzles belonging to the second group, and in the same manner, the nozzles belonging to the 3rd, 4th,. Ink is ejected. At this time, the positional relationship of the nozzles between the groups driven at adjacent timing is N / 2 dots (here, 4 dots), or {(N / 2) -1} dots (here, 3 dots). ) Separated. For example, the fifth nozzle belonging to the second group is separated by (N / 2 =) 4 dots from the first and ninth nozzles belonging to the first group that are driven to discharge before that. Then, {(N / 2) −1 =} 3 dots are separated from the second and tenth nozzles belonging to the third group that are driven to perform ejection. As described above, the distance between the nozzles belonging to the groups driven at the timings adjacent to each other is set to N / 2 bits or {(N / 2) -1} dots, so that the ink can be used at the immediately preceding timing. The influence of the pressure wave of the ink droplet from the nozzle that ejects ink on the ink droplet at the nozzle that ejects ink at the current timing can be reduced.
[0031]
In the present embodiment, the time interval of ink ejection timing (hereinafter, adjacent delay time td) between nozzle groups driven at adjacent timings is set to about 28 μs. In order to form an image in one pass, the adjacent delay time td is between the head driving period T and the group number N.
td ≦ T / N
The relationship must be established.
[0032]
Further, in order to reduce the influence of the pressure wave generated by the nozzle that ejects ink at the immediately preceding timing and stabilize the ink ejection speed and the ink ejection amount, the adjacent delay time td is at least electrically connected to the thermal energy generating element 2009. It must be greater than the time tmax (approx. 12 μs) from when the target pulse is applied until the foamed foam reaches the maximum volume.
[0033]
tmax <td
Furthermore, it is more desirable that the time is longer than the time tb (about 25 μs) until the foamed bubbles are condensed. Therefore, the relationship is
tb <td
become that way.
[0034]
FIG. 5 is a block diagram showing the configuration of the ink jet recording apparatus including the full line type recording head according to Embodiment 1 of the present invention.
[0035]
In the figure, reference numeral 500 denotes a control unit, for example, a CPU 510 such as a microprocessor, a program memory 511 storing a control program executed by the CPU 510, and various data temporarily used as a work area when the CPU 510 executes processing. RAM512 etc. which memorize | store in are provided. Reference numeral 2100 denotes the recording head unit described above, and reference numeral 501 denotes a motor driver, which controls the rotation of the sheet feeding motor 502 based on an instruction from the control unit 500 and conveys a recording sheet used for recording.
[0036]
FIG. 6 is a flowchart showing a control process in the ink jet recording apparatus of the first embodiment, and a control program for executing this process is stored in the program memory 511.
[0037]
First, in step S1, print data from an external device such as a host computer is input, and when the creation of data for one line (here, 7168 pixels) is completed, the process proceeds to step S2, and the created image data is transferred to the clock signal CK. Synchronously with this, the data is sent to the shift register 301 of each drive element of the recording head unit 2100. When the recording data for one line is thus stored in each shift register 301 of IC1 to IC28, the process proceeds to step S3, where a latch signal (LT *) is output and the recording data is latched in the latch circuit 302 of each driving element. To do. In step S3, the sheet feeding motor 502 is rotationally driven to convey the recording sheet using an electrostatic adsorption method described later. When the recording sheet reaches the recording position, the process proceeds to step S4. In step S4, all the selection signals SEL1 to SEL7 for selecting the first to seventh blocks are output at a high level, and in step S5, all the group selection signals EA *, EB *, and EC * are set to “1” (first Group selection) and output. In step S6, the heat signals (ENB1 to 28) are set to high level and output. As a result, the first group of heating resistors shown in FIG. 4 are driven, and printing is performed with ink from the nozzles of the first group.
[0038]
Next, the process proceeds to step S7 to check whether or not the recording of one line has been completed. If not, the process proceeds to step S8, waits for a predetermined time (adjacent delay time td), and proceeds to step S9. The selection signals EA *, EB *, and EC * are updated, and then the second group is selected (EA * = 0, EB * = EC * = 1). In this way, the process proceeds to step S6, and the heat signals (ENB1 to 28) are set to the high level in the same manner as described above, and printing by the next nozzle group is performed. Thus, in steps S7 to S9, the groups are sequentially selected, and when the recording by the eighth group (EA *, EB *, EC * = 0) is completed, the process proceeds from step S7 to step S10, and the printing process for one page is completed. If it is not completed, the process is terminated. If it is not completed, the process proceeds to step S11, and the sheet feeding motor 502 is rotated to convey the recording sheet by, for example, one dot corresponding to the resolution. Then, the process returns to step S3. In this case, data reception from the host or the like, creation of recording data, data transfer to the shift register 301 of the recording data, and the like are performed in the background during recording of the previous line, for example. By outputting a latch signal in step S3, the recording data of the next line is latched by the latch circuit 302.
[0039]
As described above, the plurality of nozzles of the recording head are divided into N groups and time-division driving is performed, and the ink ejection amount and the ink ejection speed due to the influence of the pressure wave generated by the nozzle that ejects ink at the previous timing. The recording quality can be improved by reducing the influence on the ink and performing stable ink ejection.
[0040]
Here, the feature of the present embodiment is that when performing the above-described time-division driving, the influence of static electricity when the recording sheet is conveyed by the electrostatic adsorption method at the same time between the nozzles that eject ink simultaneously affects the recorded image. This is an interval that is not given. Such an embodiment will be described below.
[0041]
FIG. 9 is a diagram for explaining a color ink jet recording apparatus 1200 of the present invention that electrostatically conveys a recording sheet. In the color inkjet recording apparatus 1200 of the present embodiment, four recording head units 2100 are mounted. The recording head unit 2100 of the present embodiment has the same configuration as the recording head unit 2100 described above except that the nozzle arrangement pitch is 63.5 [μm]. These four recording head units 2100 are supplied with inks of yellow, magenta, cyan, and black (not shown), respectively, and perform color recording using these four colors. The recording sheets 1005 stacked on the paper feed tray 1004 are transported by the sheet transport belt 1002 and are recorded by ink ejected from each recording head unit 2100 when passing under the color recording head unit 2100. . The recording sheet 1005 on which the color image is recorded in this manner is stacked on the paper discharge tray 1003.
[0042]
The sheet conveying belt 1002 is wound around a sheet conveying belt roller 1001, and an electrode 1012 is disposed on the sheet conveying belt 1002 so that the recording sheet 1005 can be reliably conveyed. A power supply unit 1013 is disposed at the end of the electrode 1012, and a charge supply brush 1011 made of a conductive material, which is disposed in the charge supply unit 1010 for applying a high potential to the electrode 1012, comes into contact therewith. ing. By applying a high potential to the charge supply unit 1010, a high potential is supplied to the electrode 1012, and the recording sheet 1005 can be adsorbed and conveyed by static electricity.
[0043]
Here, the above-described recording head unit 2100 is mounted on the color ink jet recording apparatus 1200 that performs sheet conveyance by the electrostatic adsorption method in this way.
[0044]
When ink-jet recording is performed on a sheet conveyance system using such an electrostatic adsorption method, ink droplets that fly close to each other have an influence on the flight direction due to an electrostatic field, and the recording quality is low. As mentioned above, it gets worse.
[0045]
Prior to designing the recording head unit 2100 of the present embodiment, first, as shown in FIG. 17, the recording head unit 2100 having a drive circuit capable of individually driving the thermal energy generating elements 2009 arranged in each nozzle. The relationship between the distance between the nozzles that are driven adjacent to each other, the voltage applied to the electrode 1012 and the amount of displacement of the recording dots was examined and examined. In the examination, a recording head unit in which 512 nozzles were arranged at a pitch of 63.5 [μm] was used. The examination result is shown in FIG.
[0046]
In FIG. 10, the horizontal axis indicates the distance between adjacent nozzles that discharge simultaneously, and the horizontal axis indicates the amount of misalignment of the ink adhesion position on the recording sheet.
[0047]
As shown in FIG. 10, even if the potential applied to the surface of the sheet is changed, the ink misregistration amount is 15 [μm] or less if speaking over 300 [μm] in the range up to 2000 V, and the area is hardly noticeable. Confirmed to enter.
[0048]
Next, actual images were recorded under the same conditions as in the above experiment, and the recording quality was evaluated. The result is shown in FIG. As the image quality evaluation criteria in this evaluation, the case where the occurrence of streaks could not be confirmed due to the deviation of the landing position of the ink droplet on the image was judged as “good”, and the case where streaks occurred was judged as “bad”. FIG. 19 shows a result obtained by superimposing the result on each plot point under the same conditions as those shown in FIG.
[0049]
In FIG. 19, the evaluation result of “◯” or “×” is described at the upper right of each plotted point. Referring to FIG. 19, in the region where the recording deviation amount is half of the nozzle arrangement pitch 63.5 [μm] and 31.75 [μm] or less, the image evaluation is “◯”, that is, the quality of the recorded image. Can be confirmed.
[0050]
Next, in designing a recording head unit having a nozzle arrangement pitch of 70 [μm] based on the above experimental results, the landing position deviation amount is half of 70 [μm] and is not more than 35 [μm]. The distance between the nozzles was determined experimentally. The distance between the nozzles was 140 to 420 [μm], the applied voltage was 0 to 3 kV, the landing position deviation was measured 10 times for each condition, and the average value was calculated.
[0051]
As a result, as shown in FIG. 20, when the distance between adjacent nozzles was 140 [μm], the amount of landing deviation was 35 [μm] or more under the condition that the sheet surface potential was 2 kV or more, but it was 280 [μm] or more. In other words, it was found that the amount of landing deviation can be suppressed to 35 [μm] or less even under the condition where the applied voltage is 3 kV or less. Further, when an actual image was recorded under the same conditions as this examination and the image quality was evaluated, as shown in FIGS. 20 and 21, the landing position deviation amount was 35 [μm] or less. It was confirmed that good recording quality was obtained.
[0052]
Based on the above results, the present embodiment provides an ink jet recording apparatus that uses a recording head unit in which the distance between adjacent nozzles that are turned on at the same time is 280 [μm] and that has little image quality deterioration due to landing position deviation. I was able to.
[0053]
Further, in the configuration of the recording head and the block drive as shown in FIGS. 1 to 4 described above, the adjacent nozzles that are simultaneously driven so as to maintain a good image even when the sheet surface potential is 2 kV. As described above, the interval was set to 340 μm, and as a result, a good image with no streak could be obtained.
[0054]
[Embodiment 2]
In the second embodiment, an embodiment using a recording head unit in which nozzle arrangement pitch is 42.5 [μm] and nozzles are arranged at a higher density than in the first embodiment will be described. Also in the present embodiment, as in the first embodiment, the condition that the amount of landing position deviation of the ink droplet is half of the nozzle arrangement pitch 42.5 [μm] and 21.5 [μm] or less is obtained. As a result, it was found that the distance between adjacent nozzles that are simultaneously turned on should be 300 [μm] or more. Based on this result, in the case of the recording head having a nozzle resolution of 600 dpi (nozzle pitch p = 42.5 [μm]) according to the present embodiment, the number N of divided drive part loops is set to “8”.
[0055]
Furthermore, according to the present embodiment, ink droplets from the nozzles of the groups whose ejection order is adjacent are sufficiently increased by taking into account the time interval of the ejection timings of the nozzles of the groups whose ejection order is adjacent to each other. The mutual interference in the flight direction due to the electrostatic field can be prevented before the two land on the recording sheet 1005.
[0056]
This will be described with reference to FIG.
[0057]
FIG. 11 illustrates a state in which the ink droplets 3001, 3002, and 3003 ejected from the recording head in Embodiment 2 are flying until they land on the surface of the recording sheet 1005. The horizontal distance L between the ink droplet 3001 from the first group of nozzles and the ink droplet 3002 from the second group of nozzles is determined by using the number N of divided drive groups and the nozzle pitch P.
L = P · N / 2.
[0058]
These vertical distances VH can be expressed by V1 = V · td using the flying speed V of ink and the adjacent delay time td.
[0059]
Accordingly, the linear distance L1 between the ink droplet 3001 from the first group nozzle and the ink droplet 3003 from the second group nozzle is:
L1 = √ {V²・ Td² + (N · P / 2)²}
It becomes.
[0060]
Now, the force F1 that the ink droplet 3001 receives from the ink droplet 3002 in an electrostatic field is proportional to the square of this linear distance L1, so that alpha is a constant.
F1 = α ・ L1²= Α√ {V²・ Td²+ (N · P / 2)²}
It can be expressed as Of the force F1, only the horizontal component F1x of F1 affects the landing position of the ink droplet 3001. Where F1x is

It becomes.
[0061]
Similarly, consider the force that ink drop 3002 from the second group of nozzles receives by ink drop 3003 from the third group of nozzles. There are two horizontal distances between the ink droplet 3002 and the ink droplet 3003: one that can be expressed as (N / 2-1) · P and one that can be expressed as (N / 2 + 1) · P. For each of these, when the horizontal components F2x and F3x of the force received in the electrostatic field are obtained in the same manner as F1x,
F2x = [αP · {(N / 2) −1}] √ {V²・ Td²+ {(N / 2) -1}²× P²]
F3x = [αP · {(N / 2) +1}] √ [V²・ Td²+ {(N / 2) +1}²× P²]
It becomes. When these F1x, F2x, and F3x are compared, F3x is the maximum.
[0062]
On the other hand, the horizontal distance of the ink droplets from the nozzles of the same group can be expressed by N · P, and the force F 0 that they receive each other while flying in the electrostatic field is
F0 = α · N²・ P²
It becomes. The condition for making F3x below F0 is as follows:
√ [V²・ Td²+ {(N / 2) +1}²× P²] ≦ 2N²・ P / (N + 2)
It becomes.
[0063]
Actually, V = 10 [m / S], td = 28 [μs], N = 8, P = 42.5 × 10^-6As [m], N · P> 300,
√ [V²・ Td²+ {(N / 2) +1}²× P²] ≦ 2N²・ P / (N + 2)
When a driving method that satisfies both of these equations was performed, it was confirmed that the landing position deviation of the ink due to the electrostatic field was within 15 μm, and that good recording quality was obtained.
[0064]
As described above, according to the second embodiment, when the recording head described in the first embodiment is mounted on the ink jet recording apparatus using the electrostatic adsorption method, the landing position deviation of the ink droplet due to the electrostatic field is shifted. It is an object of the present invention to provide an ink jet recording apparatus that can be minimized and perform good recording.
[0065]
[Embodiment 3]
FIG. 7 is a diagram for explaining the third embodiment of the present invention. In the third embodiment, a plurality of nozzles of the recording head unit 2100 are divided into eight time-division driving groups and a nozzle interval for simultaneous driving is determined in consideration of the influence of electrostatic conveyance. This is the same as in the first embodiment. The difference between the first embodiment and the second embodiment is that the nozzles of the recording head unit 2100 are further divided into seven blocks from 1 to 7, and the drive timings of a plurality of nozzles belonging to the same group are further time-divided. It is in the point.
[0066]
As shown in FIG. 7, ink is ejected from the nozzles belonging to the first block of the first group, and after a delay of about 4 μs, ink is ejected from the nozzles of the second block of the first group. Similarly, the nozzles up to the seventh block of the first group are sequentially driven with a delay of 4 μs to perform ink ejection. Each group is selected by the signals EA *, EB *, and EC *, and each block is selected by signals SEL1 to SEL7.
[0067]
When printing by the nozzles of the first group is completed in this way, ink is then ejected by the nozzles of the first block of the second group. Thus, by dividing the drive timing of 896 nozzles belonging to the same group into 7, the number of thermal energy generating elements 2009 driven simultaneously can be further reduced to “128”. As a result, since the current that flows instantaneously through the single thermal energy generating element 2009 is about 200 mA, the total of the current that flows instantaneously can be reduced to a maximum of about 25.6 A.
[0068]
The process in this case is shown in the flowchart of FIG. The configuration of the ink jet recording apparatus according to the third embodiment is the same as that of the first embodiment described above, and a description thereof will be omitted. Further, in FIG. 8, the same reference numerals are given to the portions common to the flowchart of FIG. 6 described above, and the description thereof is omitted.
[0069]
In the third embodiment, the first block is selected in step S4-1 after step S3 (SEL = 1, SEL2-7 = 0), and the signals EA *, EB *, EC * = ( The first group is selected as 1,1,1). In step S6, ENB1 to ENB28 are output to drive the heating resistor, and in step S6-1, here, the process waits for 4 μs and proceeds to step S6-2. Here, it is checked whether or not the recording process by all the blocks of the first group is completed. If not, the process proceeds to step S6-3, and a selection signal SELi (i = 1 to 7) for selecting the next block is sent. Output. When the recording by the first group of nozzles is thus completed, the process proceeds from step S6-2 to step S7, and as described above, it is checked whether the recording of one line (by the first to eighth group nozzles) has been completed. If not, the operation proceeds to step S8, and if completed, the operation proceeds to step S10.
[0070]
As described above, according to the third embodiment, a plurality of nozzles belonging to the same group are further divided into a plurality of blocks, and time-division driving is performed in units of blocks, thereby reducing the maximum current value that instantaneously flows in the recording head. Yes. As a result, the burden on the head power supply, the power supply capacitor, and the like can be reduced, and more stable ink ejection can be performed.
[0071]
[Embodiment 4]
13 to 15 are diagrams for explaining the ink jet recording head according to the fourth embodiment of the present invention, FIG. 13 is a schematic perspective view of the ink jet recording head according to the fourth embodiment, and FIG. FIG. 15A is a schematic top view of the ink jet recording head, and FIG. 15B is a cross-sectional view taken along line AA of FIG. 15A. FIG. 15C is a cross-sectional view taken along the line B-B in FIG.
[0072]
The inkjet recording head according to Embodiment 4 shown in FIG. 13 has a plurality of discharge ports 202 for discharging ink on the surface side near the center of the recording element substrate 201, and is discharged from these discharge ports 202. Recording is performed with ink droplets.
[0073]
As shown in FIG. 14 and FIGS. 15A to 15C, heating heaters 204 are formed on the recording element substrate 201 corresponding to the respective discharge ports 202, and these heating heaters 204 are formed. The ink is foamed by energizing and heating, and the ink as the recording liquid is ejected by the kinetic energy.
[0074]
Each wiring from the heater 204 extends to a mounting portion of the driving element 205 on the recording element substrate 201 and is electrically connected to the driving element 205 mounted thereon. The drive element 205 is connected to the recording element substrate 201 by a COB (chip on board) connection method through an anisotropic conductive film. In addition to the transistor circuit, the driving element 205 includes a logic circuit for driving the transistor, and a signal for driving the logic circuit is connected to the flexible film 206 via the recording element substrate 201. . Further, the flexible film 206 is connected to a circuit board 207 (FIG. 15A) made of a composite material such as glass epoxy. On the circuit board 207, an electrical connector 208 (FIG. 15B) for inputting an electrical signal from the outside is mounted.
[0075]
In the electrical connection portion of the driving element 205 and the flexible film 206, when the electrode portion is exposed, droplets scattered from the discharge port 202 or ink rebounding from the sheet adheres to the electrode and corrodes the electrode and its underlying metal. The electrode portion is covered and sealed with a silicon resin sealant (not shown) having excellent sealing properties and ion blocking properties.
[0076]
On the back side of the recording element substrate 201, a common liquid chamber 210 (FIG. 15C) formed by the recording element substrate holding member 211 and the support member 212 for holding ink is provided with a plurality of ejection ports 202. The opening is formed with a length substantially equal to the arrangement length of The recording element substrate 201 is provided with a slit 203 (FIG. 15C) for supplying the ink on the back side to the front side. The common liquid chamber 210 further communicates with ink supply ports 215 and 216. When ink is ejected, ink is supplied from an ink tank (not shown) outside the ink jet recording head through both ink supply ports 215 and 216. It is configured to receive.
[0077]
When filling the ink jet recording head with ink, the ink is pressurized and introduced from the ink supply port (inflow) 215, and the air in the common liquid chamber 210 is mainly extracted from the ink supply port (outflow) 216. The common liquid chamber 210 can be filled without leaving bubbles. This operation is continued until the ink is completely filled in the common liquid chamber 210, and during that time, the ink mixed with bubbles is discharged from the ink supply port (outflow) 216. Inflow) The ink supply flow path configuration is such that the ink is circulated back to the original ink tank (not shown) upstream of 215.
[0078]
FIG. 16 is a diagram illustrating a circuit configuration of the ink jet recording head substrate according to the fourth embodiment. In the figure, an example of a drive circuit using each drive transistor and a drive IC in which the shift register and the latch do not correspond one to one is shown.
[0079]
As shown in the drawing, the number of drivers in the driving transistor 1600 is 256 per IC, whereas the shift register 1601 and the latch 1602 are both 16 bits. Image data (SI) is serially transferred to the shift register 1601 and 16-bit data is transferred to and held in the shift register 1601, and then the 16-bit data is stored in the latch 1602. Each output of the 16-bit latch is connected to 16 signal lines, and is ANDed by an AND circuit 1604 with an output signal of a decoder 1603 which is externally input by control. Further, a logical product of the output signal of the AND circuit 1604 and the ENB signal (ENB0, ENB1) for determining the pulse width for driving the transistor is taken by the AND circuit 1605, and the driver circuit 1600 is driven by the output signal.
[0080]
When actually recording the image data, first, the image data is first serially input to the 16-bit shift register 1601, and when the 16-bit image data is transferred, the image data is latched by the latch circuit 1602. To do. Next, signals BE0 * to BE3 * (* indicates a negative logic signal) are input to the decoder 1603, only the first of the decoder 1603 is set to high level, and the other outputs are set to low level (BE0 * to BE3 *). = 1). When the ENB signal is applied in this state, the first, 17th, 33rd,... Transistor elements are driven, and ink is ejected from the corresponding nozzles.
[0081]
Next, as described above, the signals BE0 * to BE3 * are set to (1110), and only the ninth output of the decoder 1603 is set to the high level, and the other outputs are set to the low level. Similarly, when the ENB signal is applied, the ninth, 25th, 41st,... Transistor elements are driven and ink is ejected from the corresponding nozzles. Hereinafter, by sequentially switching the signals BE0 * to BE3 * input to the decoder 1603, for example, each nozzle can be driven in the following order to eject ink.
[0082]
# 1, # 17, # 33 ...
9th, 25th, 41st ...
2nd, 18th, 34th ...
# 10, # 26, # 42, ...
:
:
# 16, # 32, # 48, ...
By sequentially driving in this way, the present invention can be applied to the present invention in the same manner as the above-described embodiment.
[0083]
The present invention includes means (for example, an electrothermal converter or a laser beam) that generates thermal energy as energy used for ejecting ink, particularly in an ink jet recording system, and the state of ink by the thermal energy. Although a printing apparatus that causes a change has been described, a similar effect can be obtained even in a piezoelectric inkjet recording system such as that described in Japanese Patent Publication No. 6-6357. According to such a system, it is possible to achieve higher recording density and higher definition.
[0084]
As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and applying a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid, and as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. When the drive signal is pulse-shaped, the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve the discharge of liquid (ink) with particularly excellent responsiveness.
[0085]
As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0086]
As the configuration of the recording head, in addition to the combination configuration (straight liquid flow path or right-angle liquid flow path) of the discharge port, the liquid path, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting surface The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region, are also included in the present invention. In addition, for a plurality of electrothermal transducers, Japanese Patent Laid-Open No. 59-123670 which discloses a configuration in which a common slot is used as a discharge portion of an electrothermal transducer, or an aperture for absorbing pressure waves of thermal energy is disclosed. A configuration based on Japanese Patent Application Laid-Open No. 59-138461 disclosing a configuration corresponding to the discharge unit may be adopted.
[0087]
Furthermore, as a full line type recording head in which recording elements are arranged in a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, a combination of a plurality of recording heads as disclosed in the above-mentioned specification is used. Either a configuration satisfying the length or a configuration as a single recording head formed integrally may be used.
[0088]
In addition, the ink is integrated into the replaceable chip type recording head or the recording head itself, which can be electrically connected to the apparatus main body and supplied with ink from the apparatus main body by being attached to the apparatus main body. A cartridge type recording head provided with a tank may be used.
[0089]
In addition, it is preferable to add a recovery means for the recording head, a preliminary auxiliary means, etc. provided as a configuration of the recording apparatus of the present invention, since the effects of the present invention can be further stabilized. Specifically, capping means, cleaning means, pressurizing or suction means for the recording head, preheating means using a heating element different from this, or a combination thereof, or recording is used. Performing a preliminary discharge mode for performing another discharge is also effective for performing stable recording.
[0090]
In addition, as a form of the recording apparatus according to the present invention, a copying apparatus combined with a reader or the like, and a transmission / reception function are provided as an image output terminal of an information processing apparatus such as a computer or the like. It may take the form of a facsimile machine.
[0091]
Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), or a device (for example, a copier, a facsimile device, etc.) including a single device. You may apply to.
[0092]
Another object of the present invention is to supply a storage medium storing software program codes for implementing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. This can also be achieved by reading and executing the program code stored in.
[0093]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.
[0094]
As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.
[0095]
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. A case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing is also included.
[0096]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. This includes a case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.
[0097]
As described above, according to this embodiment, there is an effect that a high-quality image can be recorded without being affected by ink droplets ejected from adjacent nozzles.
[0098]
【The invention's effect】
As described above, according to the present invention, a high-quality image can be recorded by eliminating the mutual influence between adjacent recording elements that occurs in an apparatus that conveys a recording sheet using the electrostatic adsorption method.
[0099]
Further, according to the present invention, it is possible to record a high-quality image without the influence of ink droplets ejected from adjacent recording elements (nozzles).
[0100]
Further, according to the present invention, it is possible to eliminate the influence of ink droplets ejected from adjacent recording elements (nozzles) and to prevent an increase in the capacity of the driving power for the recording head.
[0101]
Further, according to the present invention, the recording elements of the recording head are divided into a plurality of groups and time-division driven to eliminate the influence of the pressure wave generated by the recording element that ejects ink at the previous driving timing at the current driving timing. Can do.
[0102]
Further, according to the present invention, even when a recording material is conveyed by an electrostatic adsorption method, there is an effect that a high-quality image can be recorded without being affected by ink droplets ejected from adjacent recording elements (nozzles). is there.
[Brief description of the drawings]
FIG. 1A is a perspective view showing a recording head unit according to an embodiment of the present invention, and FIG. 1B is an enlarged sectional perspective view of the recording head portion.
FIG. 2 is a drive circuit diagram of the recording head unit according to the embodiment of the invention.
FIG. 3 is a circuit diagram of a drive element according to an embodiment of the present invention.
FIG. 4 is a schematic diagram for explaining the driving order of the recording head unit according to the embodiment of the invention.
FIG. 5 is a block diagram showing a configuration of an ink jet recording apparatus according to an embodiment of the present invention.
FIG. 6 is a flowchart showing a control process of a control unit of the ink jet recording apparatus according to the embodiment of the present invention.
FIG. 7 is a schematic diagram illustrating the drive order of the recording head unit in the embodiment of the invention.
FIG. 8 is a flowchart showing a control process of a control unit of the ink jet recording apparatus according to the embodiment of the present invention.
FIG. 9 is a schematic perspective view of an ink jet recording apparatus according to an embodiment of the present invention.
FIG. 10 is a diagram for explaining a shift amount of a dot position by the ink jet recording apparatus.
FIG. 11 is a diagram for explaining a flying state of ink by the ink jet recording apparatus according to the embodiment of the present invention.
FIG. 12 is a schematic diagram illustrating a flying state of ink droplets from a conventional recording head.
FIG. 13 is a schematic perspective view of an ink jet recording head according to Embodiment 4 of the present invention.
14 is a cross-sectional view schematically showing an ink discharge mechanism of an ink jet recording head according to Embodiment 4 of the present invention. FIG.
FIGS. 15A and 15B are diagrams illustrating an ink jet recording head according to Embodiment 4 of the present invention, in which FIG. 15A is a schematic top view, FIG. 15B is a cross-sectional view taken along line AA in FIG. These are BB sectional drawing of Fig.15 (a).
FIG. 16 is a diagram showing a circuit configuration of the inkjet head substrate according to the present embodiment.
FIG. 17 is a diagram for explaining an equivalent circuit of a head that changes the interval between the simultaneous ejection nozzles of the present invention.
FIG.
FIG.
FIG.
FIG. 21 is a diagram illustrating the influence of the sheet surface potential and the simultaneous driving nozzle interval on landing deviation.

Claims (8)

An inkjet recording apparatus that records an image by driving a recording element of a recording head according to an image signal and causing ink to fly to a recording material,
A first selection unit capable of dividing a plurality of recording elements of the recording head into a plurality of blocks with a plurality of continuous recording elements as a unit, and selecting a recording element for each block;
A plurality of recording elements dispersed at a predetermined interval among the recording elements arranged over the plurality of blocks can be selected as one group, and each group can be selected in units of a group period obtained by dividing the driving cycle by the number of groups. A second selection means,
The recording elements in the group selected by the second selection means are further selected in order by time-division in block units using the first selection means within the group period, and the image elements are selected in the selected recording elements. Driving means for energizing and driving according to the signal;
An ink jet recording apparatus comprising: The ink jet recording apparatus according to claim 1, further comprising a transport unit that transports the recording material using an adsorption force due to static electricity. 3. The predetermined interval between the recording elements selected as the one group is an interval in which a positional deviation of landing due to the electrostatic force is equal to or less than ½ of an arrangement pitch of the recording elements of the recording head. 2. An ink jet recording apparatus according to 1. The recording head utilizes thermal energy to a recording head for ejecting the ink, according to claim 1 to 3, characterized in that it comprises a thermal energy converter for generating heat energy applied to the ink The ink jet recording apparatus according to any one of the above. An ink jet recording method for recording an image by driving a recording element of a recording head according to an image signal and causing ink to fly to a recording material,
Dividing a plurality of recording elements of the recording head into a plurality of blocks in units of a plurality of continuous recording elements, and selecting a recording element for each block unit; and
A plurality of recording elements dispersed at a predetermined interval among the recording elements arranged over the plurality of blocks can be selected as one group, and each group can be selected in units of a group period obtained by dividing the driving cycle by the number of groups. A second selection step,
The recording elements in the group selected by the second selection step are further selected in order by time-division in block units by the first selection step within the group period, and the selected recording elements are added to the image signal. And a driving process for energizing and driving in response,
An ink jet recording method comprising: 6. The ink jet recording method according to claim 5 , further comprising a transporting step of transporting the recording material using an electrostatic force. 6. predetermined intervals of the recording elements to be selected as the one group, characterized in that positional deviation of landing by the electrostatic force is an interval which is 1/2 or less of the array pitch of the recording elements of said recording head The ink jet recording method described in 1.   The inkjet recording apparatus according to claim 1, wherein the recording head is a full line head.

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