JP4164224B2 - Inkjet recording apparatus and inkjet recording method - Google Patents

Description

【０１７６】
図３２にポテンシャルの形を示す。このような斥力型のポテンシャルをドット位置に対して与えることにより、すでに発生しているドットの付近に新たなドットが生じることを防ぐ。なお、ポテンシャルの裾がマスクの領域を越える場合は、図３３に示すようにマスク領域の反対側に折り返して計算する。これは、マスク境界においてドット配置の不連続性を発生させないためである。
次に、ポテンシャルの最も小さい位置を検索しその位置にドットを追加する（ステップＳ４３）。ポテンシャルの最小値を持つ位置が複数ある場合は、ランダムに一つの位置を選択する。次に、新たに追加したドットを含むすべてのドットの位置に対応するマスク値を１減らす（ステップＳ４４）。次に、新たに追加したドットに対するポテンシャルを加算する（ステップＳ４５）。追加したドットの位置を（ｘ１、ｙ１）とすると、新たなポテンシャルは次式により求められる。
【０１７７】
【数２】

【０１７８】
前記ステップＳ４３、Ｓ４４、Ｓ４５を母マスクのすべての画素位置にドットが追加されるまで繰り返す。以上のようにして母マスクの生成が行われる。このような手順により、マスク値が一様に分散した視覚的に好ましい疑似周期的マスクパターンを生成することができる。なお、母マスクの生成のための手段は、本画像記録装置に組み込まれる必要はなく、あらかじめ別個の母マスク生成装置により母マスクデータを生成し、結果の母マスクデータのみを母マスクメモリに格納するものとする。
尚、本実施形態にて適用した数式は類似数式であれば、特に限定しなくても構わないものとする。
【０１７９】
次に、図３１のフローチャートに従い、マスク生成部１３によりマスクバッファ１４に格納されるマスクデータ３２、３４、３６、３８の生成手順を説明する。母マスクは縦横１６画素で各マスク値が０から２５５の値を持つ。まず、マスクデータをマルチパスの走査回数に量子化する（ステップＳ５０）。すなわち、本実施形態では４回の走査によるマルチパス印字であるから、マスク値０から６３を第一パスに、マスク値６４から１２７を第二パスに、マスク値１２８から１９１を第三パスに、マスク値１９２から２５５を第四パスに割り当てる。次に、各パスに対応するマスクデータの画素をオンにする（ステップＳ５２）。すなわち、第一パスのマスクデータ３２の第一パスに割り当てられた画素位置をオンにし、第二パスのマスクデータ３４の第二パスに割り当てられた画素位置をオンとし、第三パスのマスクデータ３６の第三パスに割り当てられた画素位置をオンとし、第四パスのマスクデータ３８の第四パスに割り当てられた画素位置をオンとする。次に、各パスにおける搬送量に対応して、マスクデータをローテーションする（ステップＳ５２）。すなわち、マスクデータ３４を上に４画素分、マスクデータ３６を上に８画素分、マスクデータ３８を上に１２画素分ローテーションする。
【０１８０】
以上のような構成により、ドットの分散性の高い疑似周期配列の母マスクを用いることにより、短い周期の乱数を用いた場合に生じる繰り返しパターンや、一様乱数によるマスクを用いた場合に生じる粒状性の悪化を防ぐことができる。なお、上記手段により生成したマスクパターンを以後、擬似周期配列マスクパターンと定義する。
【０１８１】
ここで、擬似周期配列マスクパターンにて、図３４に示すように、同一走査領域Ｅ（パス領域）を２分割し、各分割領域ｅ１、ｅ２における記録デューティーを異なるものとした場合について説明する。このような分割デューティーとすることにより、視覚特性上、バンディングを見えにくくするものとなっている。図１３（ａ）および図１３（ｂ）、図１４（ｃ）は、分割領域ｅ１、ｅ２の記録デューティーの設定例をそれぞれ示している。図１５（ａ）は、各分割領域ｅ１、ｅ２が均一のデューティーによって形成された画像を示し、図１５（ｂ）は前記２分割デューティーによって形成された画像を示す。いずれの画像もキャリッジを往復動することにより、形成された場合、打ち込み順序の差に起因する色ムラが上記模式図の如く顕著に見られる。なお、図３４において、Ｈ１００Ｔは、各パス領域Ｅの記録を行う複数のノズル群を示しており各ノズル群は（図では４個）のノズルｎによってそれぞれ構成されている。
【０１８２】
ここで前述の図１４（ａ）に示す均一デューティーによって形成された画像では、例えば一様なベタパターンを記録した場合、紙送りピッチでバンディングが発生する。この紙送りピッチ程度のピッチでは視覚特性上、バンディングの存在が認知されてしまい、画像品質の劣化を感じる。ところが、この第３の実施形態においても、前記第１の実施形態、第２の実施形態と同様に、紙送りピッチの半分のピッチでバンディングが発生するため、そのバンディング発生ピッチは視覚特性上、認知されるピッチ内におさまり、画像品質の劣化を感じさせることはない。本発明者の実験によれば、３３８μｍのピッチでは、打ち込み順序差などによる色ムラ（バンディング）が視覚特性上認識されにくいことを確認している。但し、それ以上のピッチを減少させても顕著な効果は見られなかった。また、分割数に関しては、例えば４パス記録の場合、各パス領域を４分割した場合に、画像劣化軽減効果が顕著に現れる。
【０１８３】
さらに、従来までのランダム関数により生成したマスクパターンの場合に対し、粒状性、マスクの周期性（テクスチャ）といった面での飛躍的に改善していることを確認している。
【０１８４】
以上のように、ある一定領域Ｅをマルチパス記録にて記録する場合、少ないパス数ほど記録デューティーの設定領域を細分化する方が往復記録にはより好ましいと言える。なお、この記録デューティーは、マルチパス数、分割数の最適な値を種々のメディア特性（吸収性、にじみ）に応じて選択、設定するようにすることも可能である。これは、予めマスクテーブルに格納しておき、上記のの条件に応じて適宜読み出すようにすることで実現できる。
【０１８５】
（第４の実施形態）
次に、本発明におけるインクジェット記録装置及びインクジェット記録方法の第４の実施形態を説明する。
この第４の実施形態においては、第３実施形態に示す生成手段と同様な手法にて、前記各主走査によって形成される同一パス領域Ｅのうち、記録ヘッドの分割領域ｅ１、ｅ２の記録デューティーがその両端部に対応する分割領域ｅ１、ｅ２の内側に位置する分割領域の記録デューティーより小なる値に設定されるものである。
【０１８６】
すなわち図１７（ａ）に示すように、従来より行われている通常の４パス記録（パス内分割数１）の場合、各ノズル列を４つのパス領域Ｅに分け、各記録領域Ｅの記録デューティーを２５％としているが、この実施形態においては、図１７（ｂ）に示すように各パス領域Ｅを２分割して分割領域ｅ１、ｅ２を設定し、かつ記録ヘッドＨ１００１の両端部分のノズルｎに対応する分割領域ｅ１、ｅ２の記録デューティーをほかの分割領域ｅ１、ｅ２より低い値（６．２５％）に設定したものであり、各パス領域内の記録デューティーは、１８．７５％〜３１．２５％までの分布となる。
そして、このようにｅ１、ｅ２における記録デューティーを設定することにより、記録ヘッドの両端部に位置するノズルｎの使用頻度は低減され、端部ヨレの発生数を確実に抑えることができ、白スジの発生を低減することができる。この白スジ抑制効果は、第２の実施形態において形成される画像（図１９参照）と、従来の４パス記録によって形成される画像（図１８参照）とを比較すれば明らかとなる。
【０１８７】
図１８に示す画像は、各パス領域Ｅへの記録デューティーを均一な値（２５％デューティー）に設定して形成される画像である。図示のように、この画像では４ドット中の１ドット（２５％）に端部ヨレが発生することになり、この端部ヨレの発生は、マルチパス数をさらに減少させたた場合に一層顕著となり、これが白スジとして明確に認知されることとなる。
これに対し、図１９に示す画像は、同じ４パス記録の場合にあって図１７Ｂに示すように、端部の分割領域ｅ１、ｅ２の記録デューティーが６．２５％（従来の均一デューティーの１／４）に設定され、かつ記録ヘッドＨ１００１の中央部に近い領域ほど記録デューティーが高くなるように設定されている。
このように、端部の記録デューティーを低い値に設定することにより、画像における端部ヨレは、１６ドット中１ドットという極めて低い頻度で発生することとなり、その端部ヨレが白スジとして認知されることはなくなる。従って、画像におけるバンドルが上記第１の実施形態と同様に解消されることに加え、さらに端部ヨレに起因する白スジの発生も解消でき、より高品質な画像を得ることができる。
【０１８８】
なお、この第２実施形態においては、パス領域Ｅを２分割した場合を例にとり説明しているが、上記分割数は３分割以上とすることも可能である。例えば、図３５（ａ）は全ての分割領域ｅ１，ｅ２，ｅ３，ｅ４で記録デューティーが２５％という均一なマスクパターンを示している。これに対し、図３５（ｂ）に示すように、両端部に位置する分割領域ｅ１、ｅ４の記録デューティーは６．２５％という比較的低い値に設定され、かつその分割領域はここでも記録ヘッドの内側へ向かうに従って高い値に設定されている。なお、図３５（ａ）においては、記録デューティーが２５％という均一なマスクパターンであるので、上述のように、分割することは必ずしも必要ではない。
【０１８９】
また、図３５（ｂ）において、Ｍ１はこの記録デューティーを設定するための擬似周期配列マスクパターンを、図３５（ａ）におけるＭは、均一デューティーにて４パス記録を行う場合の擬似周期配列マスクパターンをそれぞれ模式的に示している。図からも明らかなように、マスクパターンＭ１は端部に向かう従って集中ドットｄ１がより分散された状態となっている。
【０１９０】
このように、上記第３の実施形態及び第４の実施形態によれば、擬似周期的配列にて視覚的に好ましいドット配置を持つマスクパターンを生成することにより、乱数によるマスクパターンに比べて、繰り返しパターンの発生や粒状性をより低減することができる。
【０１９１】
なお、本発明が有効に用いられる一形態は、電気熱変換体が発生する熱エネルギーを利用して液体に膜沸騰を生じさせ、気泡を形成する形態である。
【０１９２】
【発明の効果】
以上説明したとおり、本発明によれば、各記録走査にて記録される同一記録領域内を分割し、その分割領域における記録デューティーを異なるものにしたため、通常紙送りピッチにて認知されるバンディングの発生領域を短くすることができ視角特性上、優れた効果が得られる。
また、前記各主走査によって形成される同一領域のうち、両端部に位置する分割領域に対する記録デューティーをその内側に位置する分割領域の記録デューティーより小なる値に設定し、記録ヘッドの両端部に位置するノズルの使用頻度を抑えるようにしたため、端部ノズルにおける液滴の着弾位置ズレの発生回数を低減することができ、より良好な画像品質を得ることができる。
【図面の簡単な説明】
【図１】本発明の一実施形態によるインクジェットプリンタの外観構成を示す斜視図である。
【図２】図１に示すプリンタの外装部材を取り外した状態を示す斜視図である。
【図３】本発明の一実施形態によるプリンタに用いる記録ヘッドカートリッジを組立てた状態を示す斜視図である。
【図４】図３に示す記録ヘッドカートリッジを示す分解斜視図である。
【図５】図４に示した記録ヘッドを斜め下方から観た分解斜視図である。
【図６】（ａ），（ｂ）は図３の記録ヘッドカートリッジに代えて本発明の実施形態によるプリンタに搭載可能なスキャナカートリッジの構成を示すために、そのスキャナカートリッジを天地逆にして示す斜視図である。
【図７】本発明の一実施形態のプリンタにおける電気的回路の全体構成を概略的に示すブロック図である。
【図８】図７に示した電気回路のうちメインＰＣＢの内部構成例を示すブロック図である。
【図９】図８に示したメインＰＣＢのうちＡＳＩＣの内部構成例を示すブロック図である。
【図１０】本発明の一実施形態のプリンタの動作例を示すフローチャートである。
【図１１】本発明の第１の実施形態における記録ヘッドを模式的に示す平面図である。
【図１２】本発明の第１の実施形態における画像処理部を示すブロック図である。
【図１３】同上実施形態における４パス記録において各パス内での記録デューティを示す図で、（ａ）は各走査記録領域均一なデューティ（２５％）で記録する場合を、（ｂ）は各走査記録領域の記録デューティを異なるものとした場合をそれぞれ示している。
【図１４】同上実施形態における４パス記録において各パス内の記録デューティーを示す図で、（ａ）は均一なデューティに設定した場合を、（ｂ）は各パス内の各分割領域における記録デューティを異なる値に設定した場合をそれぞれ示している。
【図１５】（ａ）は同上実施形態において通常の４パス記録に使用するランダムマスタパターンを示す模式図、（ｂ）は同上実施形態において４パス記録に使用するランダムマスタパターンを示す模式図である。
【図１６】同上実施形態において４パス記録にて形成される画像の模式図であり、各パス領域内を２分割し、各領域内の記録デューティーを異なる値に設定した場合を示している。
【図１７】同上実施形態において４パス記録における各パス内の記録デューティーを示す図で、（ａ）は均一なデューティーに設定した場合を、（ｂ）は各パス内の各分割領域における記録デューティーを異なる値に設定した場合をそれぞれ示す。
【図１８】同上実施形態において４パス記録にて形成される画像の模式図であり、（ａ）は各パス領域内を均一記録デューティーにて形成した場合を、（ｂ）は各パス領域内を２分割し、各領域内の記録デューティーを異なる値に設定した場合をそれぞれ示している。
【図１９】同上実施形態において、４パス記録において記録領域の端部のみを６．２５％の記録デューティにて形成した画像を示す模式図である。
【図２０】（ａ）は均一デューティーにて４パス記録を行なう場合のランダムマスクパターンを、（ｂ）は異なる記録デューティーを設定するためのランダムマスクパターンをそれぞれ模式的に示す図である。
【図２１】同上実施形態におけるパス数決定部の詳細な構成を示すブロック図である。
【図２２】同上実施形態において１ページの記録媒体に複数の色の領域から構成される画像を記録する例を示す図である。
【図２３】同上実施形態においてヨレの標準偏差に基づき決定した閾値によりパス数を決定する場合のフローチャートである。
【図２４】同上実施形態における画像処理の他の機能構成例を示すブロック図である。
【図２５】同上実施形態において１ページの記録媒体に記録される画像に黒文字と自然画とが混在する例を示す図である。
【図２６】同上実施形態における画像処理のさらに他の機能構成例を示すブロック図である。
【図２７】本発明の第３の実施形態である画像記録装置の構成を示すブロック図である。
【図２８】本発明の第３の実施形態における記録ヘッドの構成例を示す図である。
【図２９】同上実施形態におけるマスク処理部によって画像バッファ及びマスクバッファから記録ヘッド制御信号を生成する手順を説明する図であり、（ａ）は第１走査における記録ヘッド制御信号を生成するためのマスク処理を示した図、（ｂ）は第２走査における記録ヘッド制御信号を生成するためのマスク処理を示した図、（ｃ）は第３走査における記録ヘッド制御信号を生成するためのマスク処理を示した図、（ｄ）は第４走査における記録ヘッド制御信号を生成するためのマスク処理を示した図である。
【図３０】同上実施形態における母マスクデータの作成手順を示すフローチャートである。
【図３１】同上実施形態においてマスク処理部によりマスクバッファに格納されるマスクデータの生成手順を示すフローチャートである。
【図３２】同上実施形態においてマスク位置に対するポテンシャルを示す図である。
【図３３】同上実施形態においてポテンシャルの裾がマスクの領域を越える場合の計算方法を示す説明図である。
【図３４】同上実施形態において４パス記録にて形成される画像の模式図であり、各パス領域を２分割し、各領域内の記録デューティーを擬似周期配列マスクパターンを用いて異なる値に設定した場合を示す図である。
【図３５】（ａ）は一つのパス領域を４分割し、各パス領域の記録デューティーを均一デューティにて４パス記録を行う場合の擬似周期配列マスクパターンを模式的に示す図、（ｂ）は一つのパス領域を４分割し、各パス領域の記録デューティーを異なる値に設定した状態、及びその状態における擬似周期配列的マスクパターンを模式的に示す図である。
【図３６】（ａ）は記録ヘッドから吐出されるインク滴の適正吐出状態を示す模式図、（ｂ）は同図（ａ）のインク滴の吐出によって得られる滴濃度ムラの無い画像を示す模式図、（ｃ）は同図（ｂ）に示す画像の濃度分布を示す線図である。
【図３７】（ａ）は記録ヘッドから吐出されるインク滴のバラツキ状態を示す模式図、（ｂ）は同図（ａ）のインク滴の吐出によって得られる滴濃度ムラの生じた画像を示す模式図、（ｃ）は同図（ｂ）に示す画像の濃度分布を示す線図である。
【図３８】同上実施形態において、マルチパス記録（２パス記録）を行なった場合を示す図であり、（ａ）は記録ヘッドから吐出されるインク滴の吐出状態を示す模式図、（ｂ）は同図（ａ）のインク滴の吐出によって得られる滴濃度ムラの生じた画像を示す模式図、（ｃ）は同図（ｂ）に示す画像の濃度分布を示す線図である。
【図３９】同上実施形態において、マルチパス記録（２パス記録）によって形成される画像を示す図であり、（ａ）は１パス目で形成される画像を、（ｂ）は２パス目で形成される画像を、（ｃ）は３パス目で形成される画像をそれぞれ示している。
【図４０】記録ヘッドを模式的に示す平面図である。
【図４１】記録ヘッド側から見た液滴の端部よれ現象発生状態を示す模式図である。
【符号の説明】
Ｍ１０００ 装置本体
Ｍ１００１ 下ケース
Ｍ１００２ 上ケース
Ｍ１００３ アクセスカバー
Ｍ１００４ 排出トレイ
Ｍ２０１５ 紙間調整レバー
Ｍ２００３ 排紙ローラ
Ｍ３００１ ＬＦローラ
Ｍ３０１９ シャーシ
Ｍ３０２２ 自動給送部
Ｍ３０２９ 搬送部
Ｍ３０３０ 排出部
Ｍ４０００ 記録部
Ｍ４００１ キャリッジ
Ｍ４００２ キャリッジカバー
Ｍ４００７ ヘッドセットレバー
Ｍ４０２１ キャリッジ軸
Ｍ５０００ 回復系ユニット
Ｍ６０００ スキャナ
Ｍ６００１ スキャナホルダ
Ｍ６００３ スキャナカバー
Ｍ６００４ スキャナコンタクトＰＣＢ
Ｍ６００５ スキャナ照明レンズ
Ｍ６００６ スキャナ読取レンズ１
Ｍ６１００ 保管箱
Ｍ６１０１ 保管箱ベース
Ｍ６１０２ 保管箱カバー
Ｍ６１０３ 保管箱キャップ
Ｍ６１０４ 保管箱バネ
Ｅ０００１ キャリッジモータ
Ｅ０００２ ＬＦモータ
Ｅ０００３ ＰＧモータ
Ｅ０００４ エンコーダセンサ
Ｅ０００５ エンコーダスケール
Ｅ０００６ インクエンドセンサ
Ｅ０００７ ＰＥセンサ
Ｅ０００８ ＧＡＰセンサ（紙間センサ）
Ｅ０００９ ＡＳＦセンサ
Ｅ００１０ ＰＧセンサ
Ｅ００１１ コンタクトＦＰＣ（フレキシブルプリントケーブル）
Ｅ００１２ ＣＲＦＦＣ（フレキシブルフラットケーブル）
Ｅ００１３ キャリッジ基板
Ｅ００１４ メイン基板
Ｅ００１５ 電源ユニット
Ｅ００１６ パラレルＩ／Ｆ
Ｅ００１７ シリアルＩ／Ｆ
Ｅ００１８ 電源キー
Ｅ００１９ リジュームキー
Ｅ００２０ ＬＥＤ
Ｅ００２１ ブザー
Ｅ００２２ カバーセンサ
Ｅ１００１ ＣＰＵ
Ｅ１００２ ＯＳＣ（ＣＰＵ内蔵オシレータ）
Ｅ１００３ Ａ／Ｄ（ＣＰＵ内蔵Ａ／Ｄコンバータ）
Ｅ１００４ ＲＯＭ
Ｅ１００５ 発振回路
Ｅ１００６ ＡＳＩＣ
Ｅ１００７ リセット回路
Ｅ１００８ ＣＲモータドライバ
Ｅ１００９ ＬＦ／ＰＧモータドライバ
Ｅ１０１０ 電源制御回路
Ｅ１０１１ ＩＮＫＳ（インクエンド検出信号）
Ｅ１０１２ ＴＨ（サーミスタ温度検出信号）
Ｅ１０１３ ＨＳＥＮＳ（ヘッド検出信号）
Ｅ１０１４ 制御バス
Ｅ１０１５ ＲＥＳＥＴ（リセット信号）
Ｅ１０１６ ＲＥＳＵＭＥ（リジュームキー入力）
Ｅ１０１７ ＰＯＷＥＲ（電源キー入力）
Ｅ１０１８ ＢＵＺ（ブザー信号）
Ｅ１０１９ 発振回路出力信号
Ｅ１０２０ ＥＮＣ（エンコーダ信号）
Ｅ１０２１ ヘッド制御信号
Ｅ１０２２ ＶＨＯＮ（ヘッド電源ＯＮ信号）
Ｅ１０２３ ＶＭＯＮ（モータ電源ＯＮ信号）
Ｅ１０２４ 電源制御信号
Ｅ１０２５ ＰＥＳ（ＰＥ検出信号）
Ｅ１０２６ ＡＳＦＳ（ＡＳＦ検出信号）
Ｅ１０２７ ＧＡＰＳ（ＧＡＰ検出信号）
Ｅ００２８ シリアルＩ／Ｆ信号
Ｅ１０２９ シリアルＩ／Ｆケーブル
Ｅ１０３０ パラレルＩ／Ｆ信号
Ｅ１０３１ パラレルＩ／Ｆケーブル
Ｅ１０３２ ＰＧＳ（ＰＧ検出信号）
Ｅ１０３３ ＰＭ制御信号（パルスモータ制御信号）
Ｅ１０３４ ＰＧモータ駆動信号
Ｅ１０３５ ＬＦモータ駆動信号
Ｅ１０３６ ＣＲモータ制御信号
Ｅ１０３７ ＣＲモータ駆動信号
Ｅ００３８ ＬＥＤ駆動信号
Ｅ１０３９ ＶＨ（ヘッド電源）
Ｅ１０４０ ＶＭ（モータ電源）
Ｅ１０４１ ＶＤＤ（ロジック電源）
Ｅ１０４２ ＣＯＶＳ（カバー検出信号）
Ｅ２００１ ＣＰＵ Ｉ／Ｆ
Ｅ２００２ ＰＬＬ
Ｅ２００３ ＤＭＡ制御部
Ｅ２００４ ＤＲＡＭ制御部
Ｅ２００５ ＤＲＡＭ
Ｅ２００６ １２８４ Ｉ／Ｆ
Ｅ２００７ ＵＳＢ Ｉ／Ｆ
Ｅ２００８ 受信制御部
Ｅ２００９ 圧縮・伸長ＤＭＡ
Ｅ２０１０ 受信バッファ
Ｅ２０１１ ワークバッファ
Ｅ２０１２ ワークエリアＤＭＡ
Ｅ２０１３ 記録バッファ転送ＤＭＡ
Ｅ２０１４ プリントバッファ
Ｅ２０１５ 記録データ展開ＤＭＡ
Ｅ２０１６ 展開用データバッファ
Ｅ２０１７ カラムバッファ
Ｅ２０１８ ヘッド制御部
Ｅ２０１９ エンコーダ信号処理部
Ｅ２０２０ ＣＲモータ制御部
Ｅ２０２１ ＬＦ／ＰＧモータ制御部
Ｅ２０２２ センサ信号処理部
Ｅ２０２３ モータ制御バッファ
Ｅ２０２４ スキャナ取込みバッファ
Ｅ２０２５ スキャナデータ処理ＤＭＡ
Ｅ２０２６ スキャナデータバッファ
Ｅ２０２７ スキャナデータ圧縮ＤＭＡ
Ｅ２０２８ 送出バッファ
Ｅ２０２９ ポート制御部
Ｅ２０３０ ＬＥＤ制御部
Ｅ２０３１ ＣＬＫ（クロック信号）
Ｅ２０３２ ＰＤＷＭ（ソフト制御信号）
Ｅ２０３３ ＰＬＬＯＮ（ＰＬＬ制御信号）
Ｅ２０３４ ＩＮＴ（割り込み信号）
Ｅ２０３６ ＰＩＦ受信データ
Ｅ２０３７ ＵＳＢ受信データ
Ｅ２０３８ ＷＤＩＦ（受信データ／ラスタデータ）
Ｅ２０３９ 受信バッファ制御部
Ｅ２０４０ ＲＤＷＫ（受信バッファ読み出しデータ／ラスタデータ）
Ｅ２０４１ ＷＤＷＫ（ワークバッファ書込みデータ／記録コード）
Ｅ２０４２ ＷＤＷＦ（ワークフィルデータ）
Ｅ２０４３ ＲＤＷＰ（ワークバッファ読み出しデータ／記録コード）
Ｅ２０４４ ＷＤＷＰ（並べ替え記録コード）
Ｅ２０４５ ＲＤＨＤＧ（記録展開用データ）
Ｅ２０４７ ＷＤＨＤＧ（カラムバッファ書込みデータ／展開記録データ）Ｅ２０４８ ＲＤＨＤ（カラムバッファ読み出しデータ／展開記録データ）
Ｅ２０４９ ヘッド駆動タイミング信号
Ｅ２０５０ データ展開タイミング信号
Ｅ２０５１ ＲＤＰＭ（パルスモータ駆動テーブル読み出しデータ）
Ｅ２０５２ センサ検出信号
Ｅ２０５３ ＷＤＨＤ（取込みデータ）
Ｅ２０５４ ＲＤＡＶ（取込みバッファ読み出しデータ）
Ｅ２０５５ ＷＤＡＶ（データバッファ書込みデータ／処理済データ）
Ｅ２０５６ ＲＤＹＣ（データバッファ読み出しデータ／処理済データ）
Ｅ２０５７ ＷＤＹＣ（送出バッファ書込みデータ／圧縮データ）
Ｅ２０５８ ＲＤＵＳＢ（ＵＳＢ送信データ／圧縮データ）
Ｅ２０５９ ＲＤＰＩＦ（１２８４送信データ）
Ｈ１０００ 記録ヘッドカートリッジ
Ｈ１００１ 記録ヘッド
Ｈ１１００ 記録素子基板
Ｈ１１００Ｔ 吐出口
Ｈ１２００ 第１のプレート
Ｈ１２０１ インク供給口
Ｈ１３００ 電気配線基板
Ｈ１３０１ 外部信号入力端子
Ｈ１４００ 第２のプレート
Ｈ１５００ タンクホルダー
Ｈ１５０１ インク流路
Ｈ１６００ 流路形成部材
Ｈ１７００ フィルター
Ｈ１８００ シールゴム
Ｈ１９００ インクタンク
ｎ ノズル
Ｎ ノズル群[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording apparatus that performs recording by ejecting ink from nozzles, and more particularly, to a recording head in which a plurality of nozzle groups each having a plurality of nozzles are arranged, in the same main scanning recording area on a predetermined recording medium. In contrast, the present invention relates to a recording apparatus that employs a so-called multi-pass method in which main scanning is performed a plurality of times by different nozzle groups, and a thinned image is formed according to a thinning mask pattern by each main scanning to complete the image. The present invention relates to reduction of image degradation factors such as streaks.
[0002]
The present invention is applied to a general printing apparatus, a facsimile machine having a copying machine and a communication system, a word processor having a printing unit, and an industrial recording apparatus combined with various processing apparatuses. In addition, it can be applied to a printing apparatus and a processing apparatus such as etching.
[0003]
[Prior art]
A recording apparatus such as a printer, a copying machine, or a facsimile is configured to record an image formed of a dot pattern on a recording medium such as paper or a plastic thin plate based on image information. This recording apparatus can be classified according to the recording system into an ink jet system, a wire dot system, a thermal system, a laser beam system, etc. Among these, a recording apparatus (inkjet recording apparatus) using the ink jet system is a recording head. For example, ink (recording liquid) is ejected and ejected as droplets from the ejection port of the nozzle, and this is adhered to a recording medium for recording.
[0004]
In recent years when many recording devices are used, high-speed recording, high resolution, high image quality, low noise, and the like are required for the recording devices, and examples of the recording devices that meet such requirements include the inkjet recording device. be able to. In this ink jet recording apparatus, since recording is performed by ejecting ink from a recording head, stabilization of the ink ejection direction and stabilization of the ink ejection amount are required to satisfy the above requirements.
[0005]
For this reason, in the ink jet recording apparatus, various improvements on the apparatus main body side such as a recovery apparatus have been made, but stabilization of the ink discharge amount largely depends on the performance of the recording head alone. That is, the recording head manufacturing, such as the shape of the discharge port of the recording head and the variation of elements such as electrothermal transducers (ejection heaters) and electromechanical transducers (piezo elements) that generate energy used to eject ink A slight error that occurs during the process greatly affects the discharge amount and the direction of the discharge direction of each discharged ink, and causes deterioration in image quality as density unevenness of the finally formed image.
[0006]
Specific examples of this phenomenon are shown in FIGS. 36 (a), (b) and (c).
In FIG. 36 (a), reference numeral 1101 denotes a multi-nozzle head, and here, in order to simplify the description, eight nozzles (in this specification, unless otherwise stated, discharge ports or liquid passages and inks communicating therewith) Elements that generate energy used for ejection are collectively referred to as “nozzles.”) 1102. Reference numeral 1103 denotes ink droplets ejected by the multi-nozzles 1102, and it is ideal that the ink is ejected in the uniform direction with the uniform discharge amount as shown in the figure. That is, if ejection is performed in such a state, dots having the same size are landed on the paper surface as shown in FIG. 36B, and the density unevenness as shown in FIG. A uniform image with no image can be obtained.
[0007]
However, in reality, each nozzle has a variation, and when recording is performed in the same manner as described above, the ink ejected from each nozzle 1102 as shown in FIG. Variations in the size and orientation of the droplets 1103 occur as shown in FIG. According to this figure, there are periodically blank paper parts in the head main scanning direction, and conversely, dots overlap more than necessary, or white streaks appear in the center part of this figure. I do. The collection of dots recorded in such a state has the density distribution shown in FIG. 37C with respect to the nozzle arrangement direction, and as a result, these phenomena are usually observed when viewed with the human eye. Perceived as unevenness.
[0008]
Therefore, the following method has been proposed as a countermeasure against this density unevenness.
This method will be described with reference to FIGS. 38 (a), (b), (c) and FIGS. 39 (a), (b), (c).
In this method, in order to complete the recording area shown in FIG. 36, as shown in FIGS. 38 (a), (b), (c) and FIGS. 39 (a), (b), (c), Three scans (main recording scan) are performed by the recording head 2001. In the figure, the recording scanning area in units of four pixels, which is half of the eight pixels in the vertical direction, is completed by two recording scans (passes). Has been. In this case, the eight nozzles in the recording head 2001 are divided into groups of four upper nozzles (upper nozzle group) and four lower nozzles (lower nozzle group), and one nozzle performs recording in one scan. The dots are obtained by thinning out prescribed image data by about half according to a predetermined image data arrangement. In the second scan, the remaining half of the dots are embedded in the thinned image formed earlier, thereby completing the recording of the 4-pixel unit area.
[0009]
Such a recording method is referred to as a multi-pass recording method. If this recording method is carried out, even if a recording head having nozzles with variations in the ink discharge amount and the discharge direction is used as shown in FIG. Since it is halved, the recorded image is as shown in FIG. 38B, and the black and white stripes as shown in FIG. Accordingly, the density unevenness is considerably reduced as compared with the case shown in FIG. 37C as shown in FIG.
However, even when such a multi-pass printing method is performed, the density unevenness is not eliminated at all depending on the recording duty of each main scan, or the occurrence of new density unevenness is confirmed in the halftone. Therefore, in Japanese Patent Application Laid-Open No. 7-52465, the pitch of each recording area is made variable by setting the paper feed amount randomly in multi-pass recording. As a result, the period of the stripe unevenness is randomized, and the stripe unevenness becomes inconspicuous and high-quality image formation is realized.
[0010]
Further, Japanese Patent Application Laid-Open No. 8-25693 discloses an image that is recorded by partially overlapping an image recorded by the previous scan of the recording head and an image recorded by the next scan. Here, among the image data recorded by the previous one scan, the recording data to be recorded in the area overlapping with the next scan is masked with a random mask pattern. Further, among the image data to be recorded in the next scan, the recording data to be recorded in an area overlapping with the previous scan is masked with a reverse pattern of the random mask pattern. Then, recording is performed using the obtained image data.
[0011]
By the way, at present, the resolution and color of the image have been improved, the image quality has been improved remarkably, and the discharge amount per dot has been reduced to realize a further high resolution image, while at the same time approaching a silver-edge photo. In order to realize image quality, a technique for simultaneously recording light ink with a lighter density in addition to basic four color inks (cyan, magenta, yellow, and black) has been proposed and implemented. However, there are also concerns about adverse effects caused by reducing the discharge amount per dot (dot landing position deviation, discharge stability, etc.).
[0012]
For example, when an image is formed by a recording head having 256 nozzles at each color ejection amount of 4 pl and 1200 dpi, the landing positions of the nozzles at both ends of the recording head are significantly shifted (hereinafter, this phenomenon is referred to as the end portion). Inconvenience occurred). FIG. 40 shows a state where the landing position of the ink droplet greatly depends on the boundary of paper feeding. As shown in the figure, in a recording head with a 1200 dpi pitch and a discharge amount of 4 pl, the landing position of several dots at which recording starts is not changed, but starts to change as the carriage accelerates, and is about 50 μm.
[0013]
FIG. 41 schematically shows the ejection tendency of the recording head 1101 as seen from the carriage direction when the dots at both ends of the recording head 1101 have already started to crawl. As shown in the figure, it is clear that several nozzles 1102 at both ends of the recording head tend to be inclining. Such a tendency is particularly noticeable when an image is formed with a minimal dot such as 4p1. Then, the shading of the dots forms a portion that is recognized as a white stripe in terms of visual characteristics. For this reason, conventionally, it has been considered to increase the number of multipaths so that white lines are not visually noticeable.
[0014]
However, each of the above-described conventional techniques has the following points to be further improved.
[0015]
That is, in the technique described in Japanese Patent Laid-Open No. 7-52465, since the feed amount of the recording medium is set randomly, the occurrence frequency of white stripes is randomized although the frequency of occurrence of white stripes is randomized. Further improvement is desired for reduction.
[0016]
Further, in Japanese Patent Laid-Open No. 8-25693, the image area recorded by the previous one scan and the image area by the next scan are recorded on the recording medium in a partially overlapping manner, so that density streaks are generated. Is improved. However, when a phenomenon occurs in which the landing position accuracy of the nozzles at both ends of the recording head greatly deviates as shown in FIGS. 40 and 41, the deviation is perceived as a white stripe in terms of visual characteristics.
[0017]
In addition, in the techniques described in the above-mentioned publications, since the paper feed pitch is changed with respect to the normal paper feed pitch, control is concerned.
[0018]
Also, making the white stripe inconspicuous by increasing the number of multipaths as described above also reduces the throughput. Such a decrease in throughput has been a factor that hinders the realization of high-speed recording required for recent recording apparatuses.
[0019]
The present invention has been made paying attention to the above-mentioned problems of the prior art, and is capable of forming a high-resolution image at high speed while suppressing deterioration in image quality due to white streaks, density unevenness, and the like. The purpose is to provide a method.
[0020]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration.
[0021]
  That is, a recording head formed by arranging a plurality of nozzles is scanned a predetermined recording area on a recording medium a plurality of times, and thinned images are recorded using different nozzle groups of the recording head in each of the plurality of scannings. Thus, an inkjet recording apparatus that completes an image to be recorded in the predetermined recording area, wherein a plurality of nozzles that correspond to the nozzle groups that use the image data corresponding to the predetermined recording area in each of the plurality of scans. The means for generating image data to be recorded in each of the plurality of scans by thinning out using the thinning mask pattern, and the nozzle group facing the predetermined recording area in each of the plurality of scans, Recording control means for recording the thinned image based on the generated image data, and each of the plurality of thinning mask patterns is the nozzle array Recording pixels and non-recording pixels are arranged so that the ratio of the recording pixels is smaller in the portion corresponding to the nozzle closer to the end than the portion corresponding to the nozzle closer to the center, and the end of the recording head The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the nozzles is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group not including the end nozzle.
[0022]
  In another embodiment, a recording head formed by arranging a plurality of nozzles is scanned a predetermined recording area on a recording medium a plurality of times, and a thinned image is obtained using a different nozzle of the recording head in each of the plurality of scans. An inkjet recording apparatus that completes an image to be recorded in the predetermined recording area, and each of the plurality of nozzle groups obtained by dividing the plurality of nozzles by a predetermined number of units is scanned a plurality of times. In order to oppose the predetermined recording area in each, a conveying means for conveying the recording medium by an amount corresponding to a single nozzle group, and a plurality corresponding to each nozzle group used in each of the plurality of scans. By thinning out image data corresponding to the predetermined recording area using a thinning mask pattern, printing should be performed by each nozzle group in each of the plurality of scans. Means for generating image data, and recording control means for recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area in each of the plurality of scans. Each of the plurality of thinning-out mask patterns is arranged such that a recording pixel and a non-recording pixel are arranged so that the ratio of the recording pixels decreases along the nozzle array from the center side to the end side of the array. The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzle of the recording head is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group not including the end nozzle. It is characterized by.
  In yet another embodiment, a recording head formed by arranging a plurality of nozzles is scanned a predetermined number of times on a predetermined recording area of a recording medium, and thinning is performed using different nozzle groups of the recording head in each of the plurality of scans. An inkjet recording apparatus that completes an image to be recorded in the predetermined recording area by recording an image, wherein the different nozzle groups are opposed to the predetermined recording area in each of the plurality of scans. Corresponding to a conveying unit that conveys the recording medium by an amount corresponding to the width in the nozzle arrangement direction in the predetermined recording area, and a nozzle group that uses image data corresponding to the predetermined recording area in each of the plurality of scans. Means for generating image data to be recorded in each of the plurality of scans by thinning using a plurality of thinning mask patterns; and Each of the inspections includes a recording control means for recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area, and each of the plurality of thinning mask patterns includes the nozzle The recording rate decreases along the array from the center side to the end side of the array, and the recording rate of the thinning mask pattern corresponding to the nozzle group including the end nozzle of the recording head is the end nozzle. It is smaller than the recording rate of the thinning mask pattern corresponding to the nozzle group not including.
  In yet another embodiment, a recording head formed by arranging a plurality of nozzles is scanned a predetermined number of times on a predetermined recording area of a recording medium, and thinning is performed using different nozzle groups of the recording head in each of the plurality of scans. An inkjet recording apparatus that completes an image to be recorded in the predetermined recording area by recording an image, the thinning mask pattern in which recording pixels and non-recording pixels are arranged, and the plurality of scans The plurality of thinning mask patterns corresponding to each of the nozzle groups used in each of the plurality of thinning mask patterns, the image data corresponding to the predetermined recording area, and the plurality of thinning mask patterns read from the memory Means for generating image data to be recorded by different nozzle groups in each of the scans, and in each of the plurality of scans, And a recording control means for recording the thinned image based on the generated image data using a nozzle group facing the recording area, and each of the plurality of thinning mask patterns includes a single nozzle group. As a plurality of portions corresponding to each of the divided small nozzle groups, the first portion corresponding to the small nozzle group relatively far from the central nozzle of the recording head and the small nozzle relatively close to the central nozzle A nozzle including at least a second portion corresponding to a group, wherein a ratio of recording pixels in the first portion is smaller than a ratio of recording pixels in the second portion, and includes an end nozzle of the recording head The ratio of the recording pixels of the thinning mask pattern corresponding to the group is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the central nozzle. Wherein the Rukoto.
[0023]
  In still another embodiment, a recording head formed by arranging a plurality of nozzles is scanned twice with respect to a predetermined recording area of the recording medium, and thinning is performed using different nozzle groups of the recording head in each of the two scans. An inkjet recording apparatus that completes an image to be recorded in the predetermined recording area by recording an image, and is a thinning mask pattern in which recording pixels and non-recording pixels are arranged, wherein the two scannings Based on the memory storing the two thinning mask patterns corresponding to the nozzle groups used in each, the image data corresponding to the predetermined recording area, and the two thinning mask patterns read from the memory, Means for generating image data to be recorded by different nozzle groups in each of the two scans, and the predetermined recording in each of the two scans. Recording control means for recording the thinned image based on the generated image data using a nozzle group facing the region, and each of the two thinning mask patterns is arranged in the array along the nozzle array. The recording pixels and the non-recording pixels are arranged so that the ratio of the recording pixels gradually decreases in a plurality of steps from the central portion side toward the end portion side, and the plurality of steps has three or more steps. To do.
  In yet another embodiment, a recording head formed by arranging a plurality of nozzles is scanned twice with respect to a predetermined recording area on the recording medium, and different nozzle groups of the recording head are used for each of the two scans. An inkjet recording apparatus that completes an image to be recorded in the predetermined recording area by recording a thinned image, wherein each of the two nozzles is formed by dividing each of the plurality of nozzles into two. In order to oppose the predetermined recording area in FIG. 2, a conveying means for conveying the recording medium by an amount corresponding to a single nozzle group, and two nozzles corresponding to each of the nozzle groups used in each of the two scans. By thinning out image data corresponding to the predetermined recording area using a thinning mask pattern, image data to be recorded by each nozzle group in each of the two scans is obtained. And a recording control means for recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area in each of the two scans, In each of the two thinning mask patterns, the recording pixels and the non-recording pixels are arrayed so that the ratio of the recording pixels gradually decreases in a plurality of stages along the nozzle array from the center to the end of the array. Thus, the plurality of stages are characterized by three or more stages.
[0024]
  Further, a recording head formed by arranging a plurality of nozzles is scanned a predetermined recording area on a recording medium a plurality of times, and a thinned image is recorded using a different nozzle group of the recording head in each of the plurality of scannings. Thus, an inkjet recording method for completing an image to be recorded in the predetermined recording area, wherein a plurality of image data corresponding to the predetermined recording area corresponds to a plurality of nozzle groups used in each of the plurality of scans. The step of generating image data to be recorded in each of the plurality of scans by thinning out using the thinning mask pattern, and the group of nozzles facing the predetermined recording area in each of the plurality of scans. Recording the thinned image based on the generated image data, wherein each of the plurality of thinned mask patterns is closer to the center of the nozzle array. A recording pixel and a non-recording pixel are arranged so that the ratio of the recording pixel is smaller in the portion corresponding to the nozzle closer to the end than the portion corresponding to the nozzle, and the nozzle including the end nozzle of the recording head The ratio of the recording pixels of the thinning mask pattern corresponding to the group is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group not including the end nozzle.
  In another embodiment, a recording head formed by arranging a plurality of nozzles is scanned a predetermined recording area on a recording medium a plurality of times, and a thinned image is obtained using a different nozzle of the recording head in each of the plurality of scans. An inkjet recording method for completing an image to be recorded in the predetermined recording area by scanning a plurality of nozzle groups each obtained by dividing the plurality of nozzles by a predetermined number of units. In order to oppose the predetermined recording area in each, a transporting process for transporting the recording medium by an amount corresponding to a single nozzle group, and a plurality of nozzles corresponding to each of the nozzle groups used in each of the plurality of scans. By thinning out image data corresponding to the predetermined recording area using a thinning mask pattern, printing should be performed by each nozzle group in each of the plurality of scans. A step of generating image data, and a step of recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording region in each of the plurality of scans. In each of the plurality of thinning mask patterns, the recording pixels and the non-recording pixels are arranged so that the ratio of the recording pixels decreases along the nozzle array from the center to the end of the array. The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzle of the recording head is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group not including the end nozzle. Features.
  In yet another embodiment, a recording head formed by arranging a plurality of nozzles is scanned a predetermined number of times on a predetermined recording area of a recording medium, and thinning is performed using different nozzle groups of the recording head in each of the plurality of scans. An inkjet recording method for completing an image to be recorded in the predetermined recording area by recording an image, wherein the different nozzle groups are opposed to the predetermined recording area in each of the plurality of scans. Corresponding to a conveying step of conveying the recording medium by an amount corresponding to the width in the nozzle arrangement direction in the predetermined recording area, and a nozzle group using image data corresponding to the predetermined recording area in each of the plurality of scans. Generating the image data to be recorded in each of the plurality of scans by thinning using a plurality of thinning mask patterns; and Each of the inspections includes a step of recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area, and each of the plurality of thinning mask patterns is arranged in the nozzle array. Along the direction from the center to the end of the array, the recording rate decreases, and the recording rate of the thinning mask pattern corresponding to the nozzle group including the end nozzle of the recording head includes the end nozzle. It is smaller than the recording rate of the thinning mask pattern corresponding to no nozzle group.
[0025]
  In yet another embodiment, a recording head formed by arranging a plurality of nozzles is scanned a predetermined number of times on a predetermined recording area of a recording medium, and thinning is performed using different nozzle groups of the recording head in each of the plurality of scans. An inkjet recording method for completing an image to be recorded in the predetermined recording area by recording an image, wherein the method is a thinning mask pattern in which recording pixels and non-recording pixels are arranged, and the plurality of scans A step of reading the thinning mask pattern from a memory storing a plurality of the thinning mask patterns corresponding to each nozzle group used in each, a plurality of image data read from the memory and image data corresponding to the predetermined recording area; A process for generating image data to be recorded by different nozzle groups in each of the plurality of scans based on a thinning mask pattern. And recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area in each of the plurality of scans, and the plurality of thinning masks Each of the patterns includes a first portion corresponding to a small nozzle group relatively far from the central nozzle of the recording head as a plurality of portions corresponding to each of the small nozzle groups obtained by dividing the single nozzle group. It includes at least a second portion corresponding to a small nozzle group relatively close to the central nozzle, and the ratio of recording pixels in the first portion is smaller than the ratio of recording pixels in the second portion. The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzles of the recording head is equal to the thinning mask corresponding to the nozzle group including the central nozzle. Characterized in that than the ratio of the recording pixels of the pattern is small.
  In still another embodiment, a recording head formed by arranging a plurality of nozzles is scanned twice with respect to a predetermined recording area of the recording medium, and a thinned image is obtained using different nozzle groups of the recording head in the two scans. Is a thinning mask pattern in which recording pixels and non-recording pixels are arranged, and each of the two scans. Reading out the thinning mask pattern from the memory storing the two thinning mask patterns corresponding to each of the nozzle groups used in the image processing, image data corresponding to the predetermined recording area, and two thinnings read out from the memory Generating image data to be recorded by different nozzle groups in each of the two scans based on a mask pattern; Each of the scanning, using the nozzle group facing the predetermined recording area, and recording the thinned image based on the generated image data, each of the two thinning mask patterns, The recording pixels and the non-recording pixels are arranged so that the ratio of the recording pixels gradually decreases in a plurality of steps along the nozzle array from the center side to the end side of the array. It is the above.
  In still another embodiment, a recording head formed by arranging a plurality of nozzles is scanned twice with respect to a predetermined recording area on the recording medium, and thinning is performed using different nozzle groups of the recording head in the two scans. An inkjet recording method for completing an image to be recorded in the predetermined recording area by recording an image, wherein each of the two nozzle groups obtained by dividing the plurality of nozzles into two is performed in each of the two scans. A step of transporting the recording medium by an amount corresponding to a single nozzle group in order to face the predetermined recording area, and two thinning masks corresponding to the nozzle groups used in each of the two scans Image data to be recorded by each nozzle group is generated in each of the two scans by thinning out image data corresponding to the predetermined recording area using a pattern. And, in each of the two scans, using the nozzle group facing the predetermined recording area, recording the thinned image based on the generated image data. Each mask pattern is formed by arranging recording pixels and non-recording pixels so that the ratio of the recording pixels gradually decreases in a plurality of stages along the nozzle array from the center to the end of the array. The plurality of stages are characterized by three or more stages.
[0026]
In the present invention having the above-described configuration, the same scanning recording area is divided at a predetermined pitch, and the duty in each divided area is different. Therefore, even when a paper feeding operation is performed at a normal pitch, it is recognized. Since the banding is generated at a short pitch, the banding is not recognized as density unevenness in terms of visual characteristics, and good image quality can be obtained.
[0027]
Also, by setting the recording duty of the areas located at both ends of each divided area to a value smaller than the duty of the other areas, and suppressing the frequency of use of the end nozzles, the landing position shifts at the end nozzles The number can be reduced, and the generation of white stripes can be surely reduced.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a recording apparatus including a liquid discharge recording head according to the present invention will be described with reference to the drawings.
[0029]
In the embodiments described below, a printer is taken as an example of a recording apparatus using an inkjet recording method.
[0030]
In this specification, “print” (sometimes referred to as “recording”) is not only for forming significant information such as characters and figures, but also for human beings visually perceived regardless of significance. Regardless of whether or not it has been manifested, it also refers to a case where an image, a pattern, a pattern, or the like is widely formed on a print medium or the medium is processed.
[0031]
Here, “print medium” refers not only to paper used in general printing apparatuses, but also to materials that can accept ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, leather, etc. Shall also say.
[0032]
Further, “ink” (sometimes referred to as “liquid”) is to be interpreted widely as the definition of “print” above, and it is applied to a print medium so that an image, a pattern, a pattern, etc. It shall refer to a liquid that can be subjected to formation or processing of the print medium, or ink processing (eg, solidification or insolubilization of the colorant in the ink applied to the print medium).
[0033]
[Device main unit]
1 and 2 show a schematic configuration of a printer using the ink jet recording method. In FIG. 1, the outer shell of the printer main body M1000 of this embodiment includes an outer member including a lower case M1001, an upper case M1002, an access cover M1003, and a discharge tray M1004, and a chassis M3019 ( (See FIG. 2).
[0034]
The chassis M3019 is composed of a plurality of plate-shaped metal members having a predetermined rigidity, forms a skeleton of the recording apparatus, and holds each recording operation mechanism described later.
The lower case M1001 forms a substantially lower half part of the exterior of the apparatus main body M1000, and the upper case M1002 forms a substantially upper half part of the exterior of the apparatus main body M1000. The hollow body structure which has the storage space which stores the. An opening is formed in each of the upper surface portion and the front surface portion of the apparatus main body M1000.
[0035]
Further, one end of the discharge tray M1004 is rotatably held by the lower case M1001, and the opening formed on the front surface of the lower case M1001 can be opened and closed by the rotation. For this reason, when executing the recording operation, the discharge tray M1004 is rotated to the front side to open the opening so that the recording sheets can be discharged and the discharged recording sheets P are sequentially stacked. It has come to be able to do. The paper discharge tray M1004 stores two auxiliary trays M1004a and M1004b. By pulling out each tray as necessary, the paper support area can be expanded or reduced in three stages. It has become.
[0036]
One end of the access cover M1003 is rotatably held by the upper case M1002, and can open and close an opening formed on the upper surface. By opening the access cover M1003, the access cover M1003 is housed inside the main body. It is possible to replace the print head cartridge H1000 or the ink tank H1900. Although not specifically shown here, when the access cover M1003 is opened and closed, the protrusion formed on the back surface rotates the cover opening and closing lever, and the rotation position of the lever is detected by a micro switch or the like. Thus, the open / closed state of the access cover can be detected.
[0037]
On the upper surface of the rear part of the upper case M1002, a power key E0018 and a resume key E0019 are provided so that they can be pressed, and an LED E0020 is provided. When the power key E0018 is pressed, the LED E0020 lights up and recording is possible. This is to inform the operator. Further, the LED E0020 has various display functions such as blinking method and color change, and informing the operator of printer troubles. Further, the buzzer E0021 (FIG. 7) can be leveled. When the trouble is solved, the recording is resumed by pressing the resume key E0019.
[0038]
[Recording mechanism]
Next, the recording operation mechanism in the present embodiment that is housed and held in the printer apparatus main body M1000 will be described.
[0039]
As a recording operation mechanism in the present embodiment, an automatic feeding unit M3022 that automatically feeds the recording sheet P into the apparatus main body, and a recording sheet P that is sent one by one from the automatic feeding unit are recorded in a predetermined manner. A conveyance unit M3029 for guiding the recording sheet P from the recording position to the discharge unit M3030, a recording unit for performing desired recording on the recording sheet P conveyed to the recording position, and a recovery process for the recording unit And a recovery unit (M5000).
[0040]
(Recording part)
Here, the recording unit will be described. The recording unit includes a carriage M4001 that is movably supported by a carriage shaft M4021, and a recording head cartridge H1000 that is detachably mounted on the carriage M4001.
[0041]
Recording head cartridge
First, a recording head cartridge used in the recording unit will be described with reference to FIGS.
[0042]
The recording head cartridge H1000 in this embodiment includes an ink tank H1900 that stores ink and a recording head H1001 that ejects ink supplied from the ink tank H1900 from nozzles according to recording information, as shown in FIG. . The recording head H1001 adopts a so-called cartridge system that is detachably mounted on a carriage M4001 described later.
[0043]
In the recording head cartridge H1000 shown here, for example, black, light cyan, light magenta, cyan, magenta and yellow ink tanks H1900 are prepared as ink tanks in order to enable high-quality color recording with photographic tone. As shown in FIG. 4, each is detachable from the recording head H1001.
[0044]
As shown in the exploded perspective view of FIG. 5, the recording head H1001 includes a recording element substrate H1100, a first plate H1200, an electric wiring substrate H1300, a second plate H1400, a tank holder H1500, a flow path forming member H1600, It comprises a filter H1700 and a seal rubber H1800.
[0045]
In the recording element substrate H1100, a plurality of recording elements for ejecting ink to one side of the Si substrate and electric wiring such as Al for supplying power to each recording element are formed by a film forming technique. A plurality of corresponding ink channels and a plurality of ejection ports H1100T are formed by photolithography, and ink supply ports for supplying ink to the plurality of ink channels are formed to open on the back surface. . The recording element substrate H1100 is bonded and fixed to the first plate H1200, and an ink supply port H1201 for supplying ink to the recording element substrate H1100 is formed therein. Further, a second plate H1400 having an opening is bonded and fixed to the first plate H1200, and the electric wiring substrate H1300 is electrically connected to the recording element substrate H1100 via the second plate H1400. Is held to be connected. The electrical wiring substrate H1300 applies an electrical signal for ejecting ink to the recording element substrate H1100. The electrical wiring substrate H1300 is located at an end portion of the electrical wiring and corresponds to the electrical wiring from the main body. An external signal input terminal H1301 for receiving a signal is provided, and the external signal input terminal H1301 is positioned and fixed on the back side of a tank holder H1500 described later.
[0046]
On the other hand, a flow path forming member H1600 is fixed to the tank holder H1500 that detachably holds the ink tank H1900 by, for example, ultrasonic welding to form an ink flow path H1501 extending from the ink tank H1900 to the first plate H1200. ing. In addition, a filter H1700 is provided at an end of the ink flow path H1501 that engages with the ink tank H1900 on the ink tank side so that entry of dust from the outside can be prevented. Further, a seal rubber H1800 is attached to the engaging portion with the ink tank H1900 so that ink can be prevented from evaporating from the engaging portion.
[0047]
Further, as described above, the tank holder portion composed of the tank holder H1500, the flow path forming member H1600, the filter H1700, and the seal rubber H1800, the recording element substrate H1100, the first plate H1200, the electric wiring substrate H1300, and the second A recording head H1001 is configured by bonding the recording element portion formed of the plate H1400 by bonding or the like.
[0048]
carriage
Next, the carriage M4001 on which the recording head cartridge H1000 is mounted will be described with reference to FIG.
[0049]
As shown in FIG. 2, the carriage M4001 is engaged with the carriage M4001 and engaged with the carriage cover M4002 for guiding the recording head H1001 to a predetermined mounting position on the carriage M4001, and the tank holder H1500 of the recording head H1001. And a head set lever M4007 that presses the recording head H1001 to set it at a predetermined mounting position.
That is, the head set lever M4007 is provided on the upper portion of the carriage M4001 so as to be rotatable with respect to the head set lever shaft, and a spring-set head set plate (not shown) is engaged with the recording head H1001. And is configured to be mounted on the carriage M4001 while pressing the recording head H1001 by this spring force.
[0050]
Further, a contact flexible printed cable (see FIG. 7, hereinafter referred to as a contact FPC) E0011 is provided at another engagement portion of the carriage M4001 with the recording head H1001, and the contact portion on the contact FPC E0011 and the recording head H1001 are provided. The provided contact portion (external signal input terminal) H1301 is in electrical contact so that various information for recording can be exchanged and power can be supplied to the recording head H1001.
[0051]
Here, an elastic member such as rubber (not shown) is provided between the contact portion of the contact FPC E0011 and the carriage M4001, and the contact portion and the carriage M4001 are connected by the elastic force of the elastic member and the pressing force by the headset lever spring. It is designed to enable reliable contact. Further, the contact FPC E0011 is connected to a carriage substrate E0013 mounted on the back surface of the carriage M4001 (see FIG. 7).
[0052]
[Scanner]
The printer in this embodiment can also be used as a reading device by mounting a scanner on the carriage M4001 instead of the recording head cartridge H1000 described above.
[0053]
This scanner moves in the main scanning direction together with the carriage M4001 on the printer side, and reads the original image fed instead of the recording medium in the course of movement in the main scanning direction. By alternately performing the reading operation and the document feeding operation in the sub-scanning direction, it is possible to read one document image information.
[0054]
FIGS. 6A and 6B are diagrams illustrating the scanner M6000 upside down in order to explain the schematic configuration of the scanner M6000.
[0055]
As shown in the figure, the scanner holder M6001 has a substantially box shape, and an optical system and a processing circuit necessary for reading are accommodated therein. Further, when the scanner M6000 is mounted on the carriage M4001, a reading unit lens M6006 is provided in a portion facing the document surface, and reflected light from the document surface is converged on the internal reading unit by the lens M6006. Therefore, the original image is read. On the other hand, the illumination unit lens M6005 has a light source (not shown) inside, and light emitted from the light source is irradiated onto the document through the lens M6005.
[0056]
A scanner cover M6003 fixed to the bottom of the scanner holder M6001 is fitted so as to shield the inside of the scanner holder M6001, and a louver-shaped grip portion provided on the side surface improves the detachable operability to the carriage M4001. Yes. The outer shape of the scanner holder M6001 is substantially the same as that of the recording head H1001, and it can be attached to and detached from the carriage M4001 by the same operation as that of the recording head cartridge H1000.
[0057]
The scanner holder M6001 accommodates a substrate having a reading processing circuit, and a scanner contact PCB connected to the substrate is exposed to the outside. When the scanner M6000 is mounted on the carriage M4001, The scanner contact PCB M6004 contacts the contact FPC E0011 on the carriage M4001 side, and the substrate is electrically connected to the control system on the main body side via the carriage M4001.
[0058]
[Configuration of printer electrical circuit]
Next, an electrical circuit configuration in the embodiment of the present invention will be described.
FIG. 7 is a diagram schematically showing an example of the overall configuration of the electrical circuit in this embodiment.
[0059]
The electrical circuit in this embodiment is mainly configured by a carriage substrate (CRPCB) E0013, a main PCB (Printed Circuit Board) E0014, a power supply unit E0015, and the like.
Here, the power supply unit E0015 is connected to the main PCB E0014 and supplies various driving powers.
The carriage substrate E0013 is a printed circuit board unit mounted on the carriage M4001 (FIG. 2). The carriage substrate E0013 functions as an interface for transmitting and receiving signals to and from the recording head through the contact FPC E0011, and an encoder according to the movement of the carriage M4001. Based on the pulse signal output from the sensor E0004, a change in the positional relationship between the encoder scale E0005 and the encoder sensor E0004 is detected, and the output signal is output to the main PCB E0014 through a flexible flat cable (CRFFC) E0012.
[0060]
Further, the main PCB E0014 is a printed circuit board unit that controls the drive of each part of the ink jet recording apparatus in this embodiment, and includes a paper edge detection sensor (PE sensor) E0007, an ASF (automatic paper feeder) sensor E0009, a cover sensor E0022, The board has I / O ports for a parallel interface (parallel I / F) E0016, a serial interface (serial I / F) E0017, a resume key E0019, an LED E0020, a power key E0018, a buzzer E0021, and the like. Still further, a motor (CR motor) E0001 that serves as a drive source for main-scanning the carriage M1400, a motor (LF motor) E0002 that serves as a drive source for transporting the recording medium, the rotation operation of the recording head, and the recording medium In addition to being connected to a motor (PG motor) E0003 that is also used for paper feeding operation to control these driving, it has a connection interface with ink empty sensor E0006, GAP sensor E0008, PG sensor E0010, CRFFC E0012, and power supply unit E0015. .
[0061]
8A and 8B are block diagrams showing the internal configuration of the main PCB E0014. In the figure, E1001 is a CPU, and this CPU E1001 has a clock generator (PCG) E1002 connected to an oscillation circuit E1005 inside, and generates a system clock by its output signal E1019. Further, it is connected to a ROM E1004 and an ASIC (Application Specific Integrated Circuit) E1006 through a control bus E1014, and controls the ASIC E1006, an input signal E1017 from a power key, and an input signal E1016 from a resume key according to a program stored in the ROM. Ink empty detection signal connected to the built-in A / D converter E1003 by detecting the state of the cover detection signal E1042 and the head detection signal (HSENS) E1013 and further driving the buzzer E0021 by the buzzer signal (BUZ) E1018. While detecting the state of the temperature detection signal (TH) E1012 by the (INKS) E1011 and the thermistor, it performs various other logical operations and condition determinations and controls the drive of the ink jet recording apparatus.
[0062]
Here, the head detection signal E1013 is a head mounting detection signal input from the recording head cartridge H1000 via the flexible flat cable E0012, the carriage substrate E0013, and the contact flexible print cable E0011, and the ink empty detection signal E1011 is an ink empty sensor. An analog signal output from E0006 and a temperature detection signal E1012 are analog signals from a thermistor (not shown) provided on the carriage substrate E0013.
[0063]
E1008 is a CR motor driver, which uses a motor power source (VM) E1040 as a drive source, generates a CR motor drive signal E1037 in accordance with a CR motor control signal E1036 from the ASIC E1006, and drives the CR motor E0001. E1009 is an LF / PG motor driver, which uses a motor power source E1040 as a drive source, generates an LF motor drive signal E1035 according to a pulse motor control signal (PM control signal) E1033 from the ASIC E1006, and drives the LF motor thereby At the same time, a PG motor drive signal E1034 is generated to drive the PG motor.
[0064]
E1010 is a power supply control circuit that controls power supply to each sensor having a light emitting element in accordance with a power supply control signal E1024 from the ASIC E1006. The parallel I / F E0016 transmits the parallel I / F signal E1030 from the ASIC E1006 to the parallel I / F cable E1031 connected to the outside, and transmits the signal of the parallel I / F cable E1031 to the ASIC E1006. The serial I / F E0017 transmits the serial I / F signal E1028 from the ASIC E1006 to the serial I / F cable E1029 connected to the outside, and transmits the signal from the cable E1029 to the ASIC E1006.
[0065]
On the other hand, a head power supply (VH) E1039, a motor power supply (VM) E1040, and a logic power supply (VDD) E1041 are supplied from the power supply unit E0015. Also, a head power ON signal (VHON) E1022 and a motor power ON signal (VMOM) E1023 from the ASIC E1006 are input to the power supply unit E0015, and control ON / OFF of the head power E1039 and the motor power E1040, respectively. The logic power supply (VDD) E1041 supplied from the power supply unit E0015 is voltage-converted as necessary, and then supplied to each part inside and outside the main PCB E0014.
[0066]
The head power signal E1039 is smoothed on the main PCB E0014 and then sent to the flexible flat cable E0011 to be used for driving the recording head cartridge H1000.
E1007 is a reset circuit that detects a decrease in the logic power supply voltage E1041, supplies a reset signal (RESET) E1015 to the CPU E1001 and the ASIC E1006, and performs initialization.
[0067]
The ASIC E1006 is a one-chip semiconductor integrated circuit and is controlled by the CPU E1001 through the control bus E1014. The above-described CR motor control signal E1036, PM control signal E1033, power supply control signal E1024, head power supply ON signal E1022, and motor power supply The ON signal E1023 and the like are output to exchange signals with the parallel I / F E0016 and the serial I / F E0017, as well as the PE detection signal (PES) E1025 from the PE sensor E0007, and the ASF detection signal from the ASF sensor E0009 ( ASFS) E1026, GAP detection signal (GAPS) E1027 from sensor (GAP) sensor E0008 for detecting the gap between the recording head and the recording medium, PG detection signal (PGS) E10 from PG sensor E0010 Detects the second state, and transmitted to the CPU E1001 through the control bus E1014 data representing the state, CPU E1001 based on the input data performs a flashing LEDE0020 controls the driving of an LED drive signal E1038.
[0068]
Further, the state of the encoder signal (ENC) E1020 is detected to generate a timing signal, and the head control signal E1021 is used to interface with the printhead cartridge H1000 to control the printing operation. Here, the encoder signal (ENC) E1020 is an output signal of the CR encoder sensor E0004 inputted through the flexible flat cable E0012. The head control signal E1021 is supplied to the recording head H1000 via the flexible flat cable E0012, the carriage substrate E0013, and the contact FPC E0011.
[0069]
FIGS. 9A and 9B are block diagrams showing an example of the internal configuration of the ASIC E1006.
[0070]
In the figure, the connection between each block shows only the flow of data related to the control of the head and each mechanism component, such as recording data and motor control data. Such control signals, clocks, and control signals related to DMA control are omitted in order to avoid complications described in the drawings.
[0071]
In FIG. 9, reference numeral E2002 denotes a PLL controller. As shown in FIG. 9, a clock (CLK) E2031 and a PLL control signal (PLLON) E2033 output from the CPU E1001 are supplied to most of the ASIC E1006. (Not shown).
[0072]
Reference numeral E2001 denotes a CPU interface (CPU I / F). The reset signal E1015, a soft reset signal (PDWN) E2032 output from the CPU E1001, a clock signal (CLK) E2031, and a control signal from the control bus E1014 Controls register read / write for each block as described, supplies clocks to some blocks, accepts interrupt signals (not shown), and outputs an interrupt signal (INT) E2034 to the CPU E1001 Then, the occurrence of an interrupt in the ASIC E1006 is notified.
[0073]
Reference numeral E2005 denotes a DRAM having areas such as a reception buffer E2010, a work buffer E2011, a print buffer E2014, and a development data buffer E2016 as recording data buffers, and a motor control buffer E2023 for motor control. Furthermore, the buffer used in the scanner operation mode has areas such as a scanner take-in buffer E2024, a scanner data buffer E2026, and a send buffer E2028 that are used in place of the recording data buffers.
[0074]
The DRAM E2005 is also used as a work area necessary for the operation of the CPU E1001. That is, E2004 is a DRAM control unit, which switches between access from the CPU E1001 to the DRAM E2005 by the control bus and access from the DMA control unit E2003 to the DRAM E2005, which will be described later, and performs a read / write operation to the DRAM E2005.
[0075]
The DMA control unit E2003 receives a request (not shown) from each block, and in the case of a write operation, an address signal or a control signal (not shown), and write data E2038, E2041, E2044, E2053, E2055, E2057. Etc. are output to the DRAM controller E20042 to access the DRAM. In the case of reading, read data E2040, E2043, E2045, E2051, E2054, E2056, E2058, and E2059 from the DRAM control unit E2004 are transferred to the request source block.
[0076]
E2006 is an IEEE 1284 I / F, which performs a bidirectional communication interface with an external host device (not shown) through a parallel I / F E0016 under the control of the CPU E1001 via the CPU I / F E2001. Data received from the I / F E0016 (PIF reception data E2036) is transferred to the reception control unit E2008 by DMA processing, and data stored in the transmission buffer E2028 in the DRAM E2005 when reading the scanner (1284 transmission data (RDPIF) E2059) Is transmitted to the parallel I / F by DMA processing.
[0077]
E2007 is a universal serial bus (USB) I / F, and performs a bidirectional communication interface with an external host device (not shown) through the serial I / F E0017 under the control of the CPU E1001 via the CPU I / F E2001. The received data (USB received data E2037) from the serial I / F E0017 is transferred to the reception control unit E2008 by DMA processing at the time of printing, and the data (USB transmitted data (RDUSB) stored in the transmission buffer E2028 in the DRAM E2005 at the time of reading the scanner. E2058) is transmitted to the serial I / F E0017 by DMA processing. The reception control unit E2008 writes the reception data (WDIF) E2038) from the I / F selected from the 1284 I / F E2006 or USB I / F E2007 to the reception buffer write address managed by the reception buffer control unit E2039. Include.
E2009 is a compression / decompression DMA controller, which receives received data (raster data) stored in the receiving buffer E2010 under the control of the CPU E1001 via the CPU I / F E2001, and receives the received buffer read address managed by the received buffer control unit E2039. The data (RDWK) E2040 is compressed / expanded in accordance with the designated mode, and written in the work buffer area as a recording code string (WDWK) E2041.
[0078]
E2013 is a recording buffer transfer DMA controller, which reads the recording code (RDWP) E2043 on the work buffer E2011 under the control of the CPU E1007 via the CPU I / F E2001, and sets each recording code in the order of data transfer to the recording head cartridge H1000. The data are rearranged to an appropriate address on the print buffer E2014 and transferred (WDWP E2044). Reference numeral E2012 denotes a work clear DMA controller, which designates work fill data (WDWF) for an area on the work buffer that has been transferred by the recording buffer transfer DMA controller E2013 under the control of the CPU E1001 via the CPU I / F E2001. E2042 is repeatedly written.
[0079]
E2015 is a recording data expansion DMA controller, and the recording written and rearranged on the print buffer is triggered by the data expansion timing signal E2050 from the head controller E2018 under the control of the CPU E1001 via the CPU I / F E2001. The code and the development data written on the development data buffer E2016 are read out, and the development record data (RDHDG) E2045 is written into the column buffer E2017 as column buffer write data (WDHDG) E2047. Here, the column buffer E2017 is an SRAM that temporarily stores transfer data (development recording data) to the recording head cartridge H1000, and a handshake signal (not shown) between the recording data expansion DMA controller E2015 and the head control unit E2018. ) Is shared and managed by both blocks.
[0080]
E2018 is a head control unit that controls the CPU E1001 via the CPU I / F E2001 to interface with the printhead cartridge H1000 or the scanner via a head control signal, and also a head drive timing signal from the encoder signal processing unit E2019. Based on E2049, a data expansion timing signal E2050 is output to the recording data expansion DMA controller.
[0081]
At the time of printing, in accordance with the head drive timing signal E2049, the developed recording data (RDHD) E2048 is read from the column buffer, and the data is output to the recording head cartridge H1000 as the head control signal E1021.
In the scanner reading mode, the take-in data (WDHD) E2053 input as the head control signal E1021 is DMA-transferred to the scanner take-in buffer E2024 on the DRAM E2005. Reference numeral E2025 denotes a scanner data processing DMA controller, which is a process in which the acquisition buffer read data (RDAV) E2054 stored in the scanner acquisition buffer E2024 is read out and subjected to processing such as averaging under the control of the CPU E1001 via the CPU I / F E2001. The completed data (WDAV) E2055 is written into the scanner data buffer E2026 on the DRAM E2005.
E2027 is a scanner data compression DMA controller. Under the control of the CPU E1001 via the CPU I / F E2001, the processed data (RDYC) E2056 on the scanner data buffer E2026 is read and compressed, and compressed data (WDYC) E2057 is read. Write and transfer to the send buffer E2028.
[0082]
An encoder signal processing unit E2019 receives an encoder signal (ENC) and outputs a head drive timing signal E2049 according to a mode determined by the control of the CPU E1001, and also the position and speed of the carriage M4001 obtained from the encoder signal E1020. Is stored in a register and provided to the CPU E1001. Based on this information, the CPU E1001 determines various parameters in the control of the CR motor E0001. Reference numeral E2020 denotes a CR motor control unit which outputs a CR motor control signal E1036 under the control of the CPU E1001 via the CPU I / F E2001.
[0083]
E2022 is a sensor signal processing unit that receives detection signals E1033, E1025, E1026, and E1027 output from the PG sensor E0010, PE sensor E0007, ASF sensor E0009, and GAP sensor E0008, and is determined by the control of the CPU E1001. In addition to transmitting the sensor information to the CPU E1001 according to the mode, a sensor detection signal E2052 is output to the DMA controller E2021 for LF / PG motor control.
[0084]
The LF / PG motor control DMA controller E2021 reads a pulse motor drive table (RDPM) E2051 from the motor control buffer E2023 on the DRAM E2005 and outputs a pulse motor control signal E1033 under the control of the CPU E1001 via the CPU I / F E2001. In addition to outputting, depending on the operation mode, a pulse motor control signal E1033 is output using the sensor detection signal as a control trigger.
E2030 is an LED control unit that outputs an LED drive signal E1038 under the control of the CPU E1001 via the CPU I / F E2001. Further, E2029 is a port control unit that outputs a head power ON signal E1022, a motor power ON signal E1023, and a power control signal E1024 under the control of the CPU E1001 via the CPU I / F E2001.
[0085]
[Printer operation]
Next, the operation of the ink jet recording apparatus according to the embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG.
[0086]
When the apparatus main body 1000 is connected to the AC power source, first, in step S1, a first initialization process of the apparatus is performed. In this initialization process, an electrical circuit system check such as a ROM and RAM check of the apparatus is performed to confirm whether or not the apparatus can operate normally.
[0087]
Next, in step S2, it is determined whether the power key E0018 provided on the upper case M1002 of the apparatus body M1000 is turned on. If the power key E0018 is pressed, the process proceeds to the next step S3. Here, a second initialization process is performed.
[0088]
In this second initialization process, various drive mechanisms and recording heads of this apparatus are checked. That is, when initializing various motors and reading head information, it is confirmed whether the apparatus can operate normally.
[0089]
In step S4, an event is waited for. That is, the apparatus monitors a command event from the external I / F, a panel key event by a user operation, an internal control event, and the like, and executes processing corresponding to the event when these events occur.
[0090]
For example, if a print command event is received from the external I / F in step S4, the process proceeds to step S5. If a power key event is generated by a user operation in the same step, the process proceeds to step S10. If another event occurs in the same step, the process proceeds to step S11.
Here, in step S5, the print command from the external I / F is analyzed, the designated paper type, paper size, print quality, paper feed method, etc. are judged, and data representing the judgment result is stored in the apparatus. Store in RAM E2005 and proceed to step S6.
Next, in step S6, paper feeding is started by the paper feeding method specified in step S5, the paper is sent to the recording start position, and the process proceeds to step S7.
In step S7, a recording operation is performed. In this recording operation, the recording data sent from the external I / F is temporarily stored in the recording buffer, then the CR motor E0001 is driven to start the movement of the carriage M4001 in the main scanning direction, and the print buffer E2014. Is supplied to the recording head H1001 to record one line, and when the recording operation for one line of recording data is completed, the LF motor E0002 is driven and the LF roller M3001 is rotated to rotate the sheet. Are sent in the sub-scanning direction. Thereafter, the above operation is repeatedly executed, and when the recording of one page of recording data from the external I / F is completed, the process proceeds to step 8.
[0091]
In step S8, the LF motor E0002 is driven, the paper discharge roller M2003 is driven, and paper feeding is repeated until it is determined that the paper has been completely sent out from the apparatus. When the paper is finished, the paper is placed on the paper discharge tray M1004a. The paper is completely discharged.
[0092]
Next, in step S9, it is determined whether or not the recording operation for all the pages to be recorded has been completed. If pages to be recorded remain, the process returns to step S5. The above operations are repeated, and when the recording operation for all the pages to be recorded is completed, the recording operation ends, and then the process proceeds to step S4 to wait for the next event.
[0093]
On the other hand, in step S10, printer termination processing is performed to stop the operation of the apparatus. In other words, in order to turn off the power of various motors and heads, after shifting to a state where the power can be turned off, the power is turned off and the process proceeds to step S4 to wait for the next event.
[0094]
In step S11, event processing other than the above is performed. For example, processing corresponding to a recovery command from various panel keys of this apparatus, an external I / F, or a recovery event that occurs internally is performed. After the process is completed, the process proceeds to step S4 and waits for the next event.
[0095]
In addition, one form in which the present invention is effectively used is a form in which bubbles are formed by causing film boiling in a liquid using thermal energy generated by an electrothermal transducer.
[0096]
[Configuration of head]
Here, the arrangement of the ejection port group of the head H1001 used in the present embodiment will be described.
[0097]
FIG. 11 is a schematic front view of a head for realizing high-density recording used in this embodiment. In this example, two rows of ejection port arrays in which 128 ejection ports are arranged at a pitch of 600 dpi (dot / inch) per row (about 42 μm pitch) are arranged in the sub-scanning direction (paper feed direction) with respect to each other. A resolution of 1200 dpi is realized with a total of 256 ejection openings per color, provided in the main scanning direction (carriage scanning direction) with a shift of 21 μm. Furthermore, in the illustrated example, such ejection port arrays are juxtaposed in the main scanning direction corresponding to six colors, and the head structure has an integrated structure that performs recording at 1200 dpi with a total of six ejection nozzle arrays. . However, in manufacturing, two parallel colors are simultaneously created as one chip, and then three chips are bonded in parallel, so a set of two adjacent chips (black (Bk) and light cyan (LC)). , Light magenta (LM) and cyan (C), and magenta (M) and yellow (Y)) have similar driving conditions. In the case of 1200 dpi, the pixel area is about 21 μm square on the paper surface, but the drop (droplet) used in this embodiment is 4 pl, and on the paper surface, a circular dot having a diameter of about 45 μm is formed.
[0098]
(Characteristic configuration of the present invention)
Next, the characteristic configuration and operation of the embodiment of the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or equivalent part as the above-mentioned basic composition.
[0099]
(First embodiment)
Here, first, an ink jet recording apparatus and a recording method using the recording head will be described. The ink jet recording apparatus according to this embodiment employs a multi-pass recording method in which an image for one recording area is completed by executing four main recording scans (4 passes).
[0100]
FIG. 12 is a block diagram schematically showing an image processing unit in this embodiment.
[0101]
In the figure, 11 is an input terminal, 12 is a recording buffer, 13 is a density unevenness (straight spot) detection unit, 14 is a pass number setting unit, 15 is a mask processing unit, 16 is a mask pattern table, 17 is a head I / F unit, Reference numeral H1001 denotes a recording head.
[0102]
Here, the bitmap data input from the input terminal 11 is received by a recording buffer control unit (not shown) corresponding to an overall part including the print buffer E2014, the development data buffer E2016, and the data development DMAE2015 shown in FIG. The data is stored in a predetermined address of the recording buffer 12 (corresponding to the column buffer E2017 shown in FIG. 9). The recording buffer 12 has a capacity capable of storing bitmap data for one scan and the paper feed amount, and constitutes a ring buffer in units of paper feed such as a FIFO memory. The recording buffer control unit controls the recording buffer 12 and activates the printer engine when bitmap data for one scan is stored in the recording buffer 12, and the recording buffer 12 sets a bit according to the position of each nozzle of the recording head. The map data is read out and input to the pass number setting unit 14. When bitmap data for the next scan is input from the input terminal 11, the recording buffer 12 is controlled so as to be stored in an empty area of the recording buffer 12 (an area corresponding to the paper feed amount for which recording has been completed).
[0103]
On the other hand, the stripe unevenness detection unit 13 detects a stripe unevenness amount for each color of the recording head H1001, for example, a deflection amount, a discharge amount, a discharge speed, and the like. For example, the detection unit 13 records a test image such as a predetermined patch or pattern by a recording head, a reading unit that reads the test image using an optical sensor, and a recording based on the reading result. The head H1001 may have a calculation unit that estimates and evaluates the amount of stripe unevenness for each color, and an EEPROM that stores the calculation result.
[0104]
In this case, as the reading unit, for example, a scanner M6000 having a configuration as shown in FIGS. 6A and 6B may be used. The scanner M6000 is mounted on the carriage M4001 instead of the recording head cartridge H1000, and the test image can be read by moving the scanner M6000 along with the carriage M4001 in the main scanning direction.
Further, an optical scanner may be attached on the recording paper conveyance path in the recording apparatus, and the pattern immediately after recording may be read and analyzed by the scanner.
[0105]
Here, a more specific configuration example of the path number setting unit in the image processing unit will be described. The path number setting unit 14 determines the number of divided paths and outputs the number of paths to the mask processing unit 15. In the mask pattern table 16, a necessary mask pattern is selected according to the determined number of divided passes from a mask pattern table stored in advance, for example, a mask pattern for 2-pass printing, 4-pass printing, and 8-pass printing. Output to processing group 15. When the mask processing unit 15 masks the bitmap data imaginary in the recording buffer 12 for each pass recording using the mask pattern and outputs it to the head driver, the recording head 18 receives the masked bitmap data in the head driver. They are rearranged in the order of use and transferred to the recording head 18.
[0106]
FIG. 21 is a block diagram showing a detailed configuration of the path number determination unit 14.
[0107]
In FIG. 21, 141 is a pass number determining unit that determines the number of passes when recording using K component recording data, 142 is a pass number determining unit that determines the number of passes when recording using C component recording data, 143 is a pass number determining unit that determines the number of passes when recording using M component recording data, 144 is a pass number determining unit that determines the number of passes when recording using Y component recording data, and 145 is the number of passes This is a pass number determination unit that detects the maximum number of passes related to the recording of the respective color components determined by the determination units 141 to 144.
[0108]
Now, the non-uniformity information for each nozzle for ejecting each color ink detected by the non-uniformity detection unit 13, for example, the standard deviation of the deviation, the average value, the maximum deviation, the ink ejection amount, the ejection speed, and the like are determined as the pass number determination unit 141. To 144. In addition, bitmap data for each scan stored in the recording buffer 12 for each color component is transferred to the pass number determination units 141 to 144. Then, the number of division passes is determined for each color component recording data.
[0109]
This determination is made based on various factors that contribute to the stripe unevenness detected by the stripe unevenness detection unit 13. For example, when attention is paid to the deviation information for each nozzle group for ejecting each color ink among such factors, a certain threshold is set based on the deviation information. For example, two threshold values of 3.6 μm are set as the standard deviation of the deviation, and these threshold values are compared with the deviation amount (σ). In the range of σ ≦ 3 μm, the two-pass recording, and 3 <σ ≦ 6 μm are doubled. Then, the number of divided passes of the bitmap data is set in advance so that 4-pass printing and 8-pass printing can be performed in the range of σ> 6 μm.
[0110]
In addition, the optimum number of recording passes for each factor is determined in the same manner for each factor that causes the occurrence of uneven stripes. Each of these factors is weighted, and the pass number determination units 141 to 144 determine the number of passes for each color component and output the result to the pass number determination unit 145. The pass number determination unit 145 extracts the maximum number of passes from the number of passes for each color component determined by the path determination units 141 to 144 and outputs the extracted number to the mask unit 115. The mask processing unit 15 selects a mask pattern corresponding to the number of passes, and transfers the masked bit map data to the head driver. Needless to say, weighting is not necessary if the factor to be considered is only twist information.
[0111]
Next, processing for determining the number of passes by applying the above method to odorous image recording will be described.
[0112]
FIG. 22 is a diagram showing an example in which an image composed of a plurality of color areas is recorded on a single recording medium. In FIG. 22, 41 is an effective recording area of a recording medium (recording paper), 42 is a black recording area, 43 is a red recording area, 44 is a green recording area, 45 is a blue recording area, 46 is a black recording area, and 47 is a natural area. This is an image recording area.
[0113]
Here, the standard deviations of the deviations relating to the nozzle for ejecting K ink, the nozzle for ejecting C ink, the nozzle for ejecting M ink, and the nozzle for ejecting Y ink are 1, 2, 3, and 4 μm, respectively. A case where the number of passes is determined based on the threshold values (the above-described two threshold values) determined based on these standard deviations will be described with reference to the flowchart shown in FIG.
[0114]
First, in step S <b> 100, bitmap data used for band recording in the black recording area 42 or one scan of the recording head 1 is transferred to the recording buffer 113. The data in this case is K component recording data.
[0115]
Next, in step S110, the pass number determination units 141 to 144 determine the number of recording passes according to the determination method described above. As described above, since only the K component recording data is used for recording in the black recording area, only the pass number determining unit 141 is used, and the other pass number determining units 142 to 144 determine the number of passes. There is no bitmap data used for. As described above, since the standard deviation of the deviation regarding the nozzle for ejecting K ink is σ = 1 (μm), the number of passes when the black recording area 42 is recorded is determined to be “2”.
[0116]
Furthermore, in step S120, the number of paths determined by the number-of-paths determination units 141 to 144 is transferred to the number-of-paths determination unit 145, and the final number of paths is determined.
[0117]
In step S130, multi-pass printing is executed based on the determination result in the pass number determination unit 145. Note that only the determination result of the pass number determination unit 141 is reflected in the recording of the black recording area 42, and two-pass recording is started.
[0118]
Finally, in step S140, it is checked whether or not a series of recording operations is completed every time recording of one layer difference of the recording head 1 is completed. Here, if the recording operation continues, the process returns to step S100 and repeats the above process. If it is determined that the recording on the recording medium has been completed, the process ends.
[0119]
When the image shown in FIG. 5 is recorded, when the recording of the black recording area 42 is completed, the recording of the red recording castle 43 is started next.
[0120]
When recording the red recording area 43, the M component recording data and the Y component recording data are used. Therefore, in the process of step S110, the path determination units 143 and 144 store the M component recording data and the Y component recording data. The number of passes when recording using each is determined. As described above, the standard deviation of the deviation regarding the nozzle that ejects M ink is σ = 3 (μm), and the standard deviation of the deviation about the nozzle that ejects Y ink is σ≡4 (μm). It is determined that the number of passes of the biography using “2” is “2” and the number of passes of printing using the Y ink is “4”. In recording in this case, there is no bitmap data used to determine the number of passes for the pass number determination units 141 and 142.
[0121]
Therefore, the outputs from the pass number determination units 143 and 144 are transferred to the pass number determination unit 145, and as a result, the maximum number of passes, that is, “4” is extracted, and the red recording area 43 is recorded with four passes. Is started.
[0122]
Similar processing is performed in the recording in the green recording area 44 and the blue recording area 45.
[0123]
Next, when recording an area in which the black recording area 46 and the natural image recording area 47 are mixed in the main scanning direction, only the K component recording data is used for recording in the black recording area 46. Since the C, M, and Y component recording data is used for recording in the image recording area 47, the recording data composed of the K, C, M, and Y components stored in the recording buffer 113 is bitmapped for each color component. The data is input to the pass number determination units 121 to 124, and for each color recording, the pass number is “2”,
“2”, “4”, and “4” are determined.
[0124]
Thereafter, these values are transferred to the pass number determination unit 145, and “4” which is the maximum value of these values is extracted, and four-pass recording is started.
[0125]
Therefore, according to the embodiment described above, the number of passes for each scan is calculated based on the accuracy information (deviation information) of the nozzles of the recording head 18 that ejects each color ink and the print data for each scan of each color component. Since it is determined dynamically, it is possible to perform high-speed recording while reducing streak.
[0126]
In addition, a threshold value is similarly set for factors other than the twist information as a factor that causes uneven stripes, and a plurality of factors are comprehensively evaluated by weighting each factor, and the optimum number of paths is determined. Also good.
[0127]
FIG. 24 is a block diagram illustrating another functional configuration example of the image processing unit.
In FIG. 24, the same components as those deviated in the embodiment shown in FIGS. 21 to 23 are denoted by the same reference numerals, and the description thereof is omitted. In particular, FIG. 24 shows from the input terminal 11 to the previous stage of the path number determination unit 145.
[0128]
As shown in FIG. 24, a buffer determination unit 302 is provided between the recording buffer 12 and the input terminal 11, and the recording buffer 12 includes a recording buffer 303 for storing K component data for natural images, and a character recording unit. A silver distribution buffer 304 that stores K component data, a recording buffer 305 that stores C component data, a recording buffer 306 that stores M component data, and a recording buffer 307 that stores Y component data.
[0129]
In addition, in this embodiment, the pass number determination unit 141 described in the embodiment illustrated in FIGS. 21 to 23 includes a pass number determination unit 141a that determines the number of passes related to recording using natural-component K component data, and a character number. It is divided into a pass number determination unit 141b that determines the number of passes related to recording using the recording K component data.
Accordingly, when the buffer determination unit 302 stores the data input from the input terminal 301 in the recording buffer 12, the buffer determination unit 302 determines whether the data is data forming a natural image or data forming a character image. To do. Conventionally, there are various means for separating a character and a natural image, such as a method using a local property (histogram, frequency measurement) of an image. Therefore, as long as the separation is possible, any separation method may be used in the present invention.
[0130]
Usually, when a character image is recorded, the tolerance of variation of individual recording heads is wider than when a natural image is recorded. That is, the permissible range recognized as a streak becomes wider.
[0131]
FIG. 25 is a diagram showing an example in which black characters and natural images are mixed in an image recorded on one page of recording medium. In FIG. 25, 51 is an effective recording area of the recording medium, 52 is a black character recording area, and 53 is a natural image recording area.
[0132]
When an image as shown in FIG. 8 is recorded, only the black text area 52 is recorded first, so that all bitmap data is stored only in the recording buffer 304. . For this reason, when recording is performed using only the K component recording data for character recording, the pass number determination unit 141b relaxes the threshold used for determining the number of passes, that is, the recording head obtained from the stripe unevenness detection unit 13 The threshold value calculated based on the 18 characteristic information or the like is set to be small so that a smaller number of paths is selected.
[0133]
As described in the embodiment shown in FIGS. 21 to 23, when the standard deviation of the deviation of the recording with K ink is 1 μm, the data is a character according to the threshold set in the embodiment shown in FIGS. Regardless of whether it is used to form an image or a natural image, 2-pass printing is performed.
[0134]
However, in this embodiment, when the K component data is used to form a natural image according to the determination by the buffer determination unit 302, the bitmap data is transferred to the recording buffer 303 and the data is used. The number of passes when recording is determined by the pass number determination unit 141a, and when the K component data is used to form a character image, the bitmap data is transferred to the recording buffer 303, and the data The number of passes when recording using is determined by the pass number determination unit 141b.
[0135]
The pass number determination unit 141a determines the number of passes in the same manner as in the examples shown in FIGS. 21 to 23. However, the pass number determination unit 141b has a wide allowable range for the quality of the character image formation with respect to the unevenness of the stripes. Therefore, the number of passes is determined so that standard deviation (1 pass printing is performed in the range where σ is σ ≦ 3 μm, 2 pass printing is performed in the range of 3 <σ ≦ 6 μm, and 4 pass printing is performed in the range of σ> 6 μm.
[0136]
As a result, according to this embodiment, if the deviation standard deviation is small, the black character area 52 may be recorded in one pass, and high-speed recording is possible.
[0137]
Since the number of passes for other recording areas is determined by the same method as in the examples shown in FIGS.
[0138]
In the configuration shown in FIG. 24, only the K component recording data is distinguished for character recording and natural image recording. However, the recording buffer for character recording is similarly applied to other color component data. By providing the pass number determination unit, the same processing can be performed for color characters, and high-speed recording can be realized.
[0139]
FIG. 26 is a block diagram showing still another functional configuration example of the image processing unit.
[0140]
In FIG. 26, the same components as those described in the examples shown in FIGS. 21 to 24 are denoted by the same reference numerals, and the deblurring thereof is omitted. In particular, FIG. 26 shows from the input terminal 111 to the path number determination unit 140.
[0141]
In FIG. 26, 130 is a data total amount measurement part.
[0142]
Here, attention is paid to changes with time of each factor cited as a streak factor. It is a well-known fact that the characteristics of the recording head, such as the ink discharge amount and the ink discharge speed, change with the recording time.
[0143]
Therefore, in this example, the total data amount measurement unit 130 counts the total data amount of each recording medium page, and when the data amount corresponding to a certain page number is exceeded, this circuit is activated and the pass number determination unit 14 is controlled so as to relax the threshold value.
[0144]
For example, when the pass number determination unit 14 is about to determine “2” as the number of passes, this circuit is activated when an image recorded by recorded data exceeds three pages or more. For example, control is performed so as to increase the number of passes determined by comparing the standard deviation of the deviation and the question value obtained by 13.
[0145]
As a result, according to the example shown here, the number of determined passes increases because there are more stripes than in a normal case (for example, two-pass recording). In this way, since the total data amount measurement unit is provided and the measurement result is reflected in the determination of the number of passes, it is possible to reduce the influence of fluctuations due to changes in the characteristics of the recording head, such as ink discharge amount and ink discharge speed, over time. This contributes to higher quality image recording.
[0146]
Incidentally, the recording duty performed in each pass in the image processing unit is set as follows.
That is, when image recording is performed in four passes, the recording duty of each pass has been set at a recording duty of 100 / number of passes = 25%. This is a typical example of the multi-pass printing method, and image deterioration due to density unevenness such as uneven stripes is reduced by increasing the number of passes.
[0147]
However, in such a conventional multi-pass method, density unevenness (hereinafter referred to as banding) occurs due to the influence of the ejection accuracy of the recording head, the ink ejection order, and the like. Further, due to the influence of the edge deviation as described above, white streaks appear remarkably for each paper feed pitch, and this is recognized in the visual characteristics and determined as image deterioration. In particular, when an image is formed by reciprocal recording, a difference in color due to a difference in the order of printing occurs, and this appears as banding.
[0148]
Therefore, in this embodiment, the banding is made difficult to see visually by performing a specific mask process. That is, in this embodiment, the same scanning area E (pass area) is divided into two, and the recording duty in each of the divided areas e1 and e2 is made different (divided duty). It is difficult to see.
FIGS. 13 (a), 14 (a), 13 (b), and 13 (b) show examples of setting the recording duty of each of the divided areas e1 and e2.
[0149]
FIG. 15A shows a normal multipass recorded image in which the divided areas e1 and e2 are formed with a uniform duty, and FIG. 15B shows an image formed with the two divided duties. . In FIG. 16, H100T indicates a plurality of nozzle groups for recording each pass area E, and each nozzle group is constituted by a plurality (four in the figure) of nozzles n.
[0150]
Here, in the image formed with the uniform duty shown in FIG. 14A, for example, when a uniform solid pattern is recorded, banding occurs at the paper feed pitch. At a pitch about this paper feed pitch, the presence of banding is perceived in terms of visual characteristics, and the image quality is degraded. However, in this embodiment, banding occurs at half the paper feed pitch, so that the banding occurrence pitch falls within the perceived pitch in terms of visual characteristics and does not feel image quality degradation.
[0151]
According to the experiment by the present inventor, it has been confirmed that, with a pitch of 338 μm, density unevenness (banding) due to an implantation order difference or the like is hardly visually recognized. However, no significant effect was observed even if the pitch was further reduced. As for the number of divisions, for example, in the case of 4-pass printing, when each pass area is divided into 4 parts, the effect of reducing the image deterioration appears significantly.
[0152]
As described above, when a certain area E is recorded in multi-pass recording, it can be said that it is more preferable for reciprocal recording to subdivide the recording duty setting area with a smaller number of passes. The recording duty can be selected and set in accordance with various media characteristics (absorbance, blurring, etc.) as the optimum values for the number of multipasses and the number of divisions. This can be implemented by storing in advance in a mask table and reading it out appropriately according to the above conditions.
[0153]
(Second Embodiment)
Next, an ink jet recording apparatus and an ink jet recording method according to a second embodiment of the present invention will be described.
[0154]
In the second embodiment, among the same pass area E formed by each main scan, the divided areas e1 and e2 corresponding to both ends of the print head have divided recording areas e1 and e2 corresponding to the both ends. It is set to a value smaller than the recording duty of the divided area located inside e2.
[0155]
That is, as shown in FIG. 17A, in the case of normal four-pass printing (division number 1) conventionally performed, each nozzle row is divided into four pass areas E, and the recording duty of each printing area E is set. In this embodiment, as shown in FIG. 17B, each pass area E is divided into two to set divided areas e1 and e2 and nozzles n at both ends of the print head H1001. Is set to a value (6.25%) lower than that of the other divided areas e1 and e2, and the recording duty in each pass area is 18.75% to 31%. Distribution up to 25%. By setting the recording duty in each of the divided areas e1 and e2 in this way, the frequency of use of the nozzles n positioned at both ends of the recording head is reduced, and the number of occurrences of end deviation can be reliably suppressed. The occurrence of white stripes can be reduced. This white stripe suppression effect is apparent when comparing the image formed in the second embodiment (see FIG. 19) with the image formed by the conventional four-pass printing (see FIG. 18).
[0156]
The image shown in FIG. 18 is an image formed by setting the recording duty for each pass area E to a uniform value (25% duty). As shown in the figure, in this image, end deviation occurs in one dot (25%) out of four dots, and this occurrence of end deviation becomes more noticeable when the number of multipaths is further reduced. This will be clearly recognized as white streaks.
In contrast, in the second embodiment, in the case of four-pass printing, as shown in FIG. 17B, the recording duty of the divided areas e1 and e2 at the end is 6.25% (conventional). The uniform duty is set to ¼), and the recording duty is set to be higher in the region closer to the center of the recording head H1001.
[0157]
Thus, by setting the recording duty of the edge to a low value, the edge deviation in the image occurs at an extremely low frequency of 1 dot out of 16 dots, and the edge deviation is recognized as a white stripe. It will not be. Therefore, in addition to eliminating the bundle in the image in the same manner as in the first embodiment, it is also possible to eliminate the occurrence of white streaks due to the edge twist, and to obtain a higher quality image.
[0158]
In the second embodiment, the case where the path area E is divided into two has been described as an example. However, the number of divisions may be three or more. For example, as shown in FIGS. 20A and 20B, one pass area E can be divided into four divided areas e1, e2, e3, and e4. In this case, the recording duty of the divided areas e1 and e4 located at both ends is set to a relatively low value of 12.5%, and the other divided areas are also higher values toward the inside of the recording head here. Is set to
[0159]
In FIG. 20B, M1 is a random mask pattern for setting the recording duty, and M in FIG. 20A is a random mask pattern for performing 4-pass printing with a uniform duty. Is shown. As is clear from the figure, the mask pattern M has the concentrated dots d uniformly, but the mask pattern M1 is in a state where the concentrated dots d1 are more dispersed toward the end.
[0160]
(Third embodiment)
Next, an ink jet recording apparatus and an ink jet recording method according to a third embodiment of the present invention will be described.
[0161]
In the first and second embodiments, when the cycle of the random number is short, a repetitive pattern is generated in the output image, or when a uniform random number is used as the random number, the granularity deteriorates due to the low frequency component of the random number. Is also a concern. Therefore, in this embodiment, a moving unit that moves a recording head having a plurality of recording elements relative to the recording medium, and the recording head is divided into a plurality of areas, and the same area on the recording medium is divided. In a recording apparatus that scans a plurality of times using the same or different regions of the recording head and forms a thinned image according to a thinning pattern in each scan to complete the image, binarization at an arbitrary level A pseudo-periodic mask arrangement in which the arrangement of non-recording pixels and recording pixels is visually preferable, mask generation means for generating a plurality of mask patterns from the mask arrangement, and the mask patterns for each of the mask patterns. And a thinning means for thinning out the recording data as a thinning pattern for the recording area.
[0162]
In the above configuration, the quasi-periodic mask array (also referred to as a quasi-random mask array) has fewer low-frequency components than the uniform random number, and thus works to prevent the occurrence of repetitive patterns and the deterioration of graininess. FIG. 27 is a block diagram showing a configuration of an image recording apparatus as a third example of the present invention. 10 is an input terminal for image data, 11 is an image buffer for storing image data to be printed by one scan, 12 is an address counter for synchronizing image data and mask data, and 13 is mask data. 14 is a mask buffer for storing mask data, 15 is a mask processing unit for generating a head drive signal from the image data and the mask data, 16 is a printer for forming an image according to the head drive signal, 17 Is a mother mask memory (ROM) for storing mother mask data generated in advance by another apparatus.
[0163]
The printer 16 forms an image on the recording medium by moving the recording head 101 vertically and horizontally relative to the recording medium 104. The recording head 101 is composed of a plurality of recording elements, and each recording element forms an image by ejecting ink onto a recording medium by an ink jet method. Reference numeral 102 denotes a moving unit for moving the recording head, and reference numeral 103 denotes a conveying unit that conveys the recording medium. In such a printer, it is difficult to avoid the occurrence of band-like density unevenness on the image due to variations in the arrangement and characteristics of the recording elements constituting the recording head 101 or the mechanical accuracy of the moving device and the conveying device.
[0164]
FIG. 28 is a diagram illustrating a configuration example of the recording head 101. In FIG. 28, a recording head having a configuration in which recording elements are arranged in a line in the paper conveyance direction is shown for simplicity of explanation, but the number and arrangement of the recording elements are arbitrary. For example, a plurality of recording elements are provided. Even if there is a row, the recording elements may be arranged in a zigzag manner. In FIG. 28, reference numeral 120 denotes recording elements, which are arranged vertically at regular intervals.
[0165]
The recording head 101 drives each recording element at a constant driving interval while moving from the left to the right with respect to the recording medium 104 to record an image on the recording medium. When one scan is completed, the recording head is returned to the left end, and at the same time, the recording medium is conveyed by a certain amount. An image is recorded by repeating the above processing.
[0166]
Printing by the multi-pass recording method is performed by making the conveyance amount of the recording medium per scan smaller than the number of recording elements. In this embodiment, a case where the conveyance amount of the recording medium is set to ¼ of the number of recording elements will be described.
[0167]
FIGS. 29A to 29D are diagrams illustrating a procedure for generating a printhead control signal from the image buffer 11 and the mask buffer 14 by the mask processing unit 15. The image buffer 11 is a memory that can record the same number of horizontal pixels that can be printed in the horizontal direction and the same number of pixels as the recording elements in the vertical direction. For convenience, the number of horizontal pixels is set to 16 in FIGS. 29A to 29D, but the actual number of horizontal pixels in the image buffer is the same as the number of pixels that can be recorded in the horizontal direction of the recording medium. . For example, if the horizontal width of the area that can be recorded on the recording medium is 8 inches and the resolution of the printer is 600 DPI, the number of horizontal pixels that can be recorded is 4800 pixels, so the number of horizontal pixels in the image buffer is also 4800 pixels. It becomes. In FIGS. 29A to 29D, each square corresponds to a pixel, a white square 30 indicates that the pixel is not recorded, and a black square 31 indicates that the pixel is recorded. To express. The size of the mask buffer 14 is 16 pixels in the horizontal direction and 16 pixels in the vertical direction, which is the same number as the printing elements.
[0168]
FIG. 29A is a diagram illustrating mask processing for generating a printhead control signal in the first scan. First, in the first scan, the image data for four pixels from the upper end of the input image is stored in the area for the lower four pixels of the image buffer 11. Next, an AND operation is performed for each pixel in the image buffer 11 and the first mask pattern 32 generated from the mask generation unit 13 according to a procedure to be described later, thereby generating a head drive signal. That is, both the image buffer 11 and the mask pattern 32 drive only the recording elements corresponding to the pixels in the recording state.
[0169]
FIG. 29B is a diagram illustrating mask processing for generating a printhead control signal in the second scan. After the first scanning is performed, the conveyance unit 103 performs ¼ of the number of recording elements, that is, paper feeding for four pixels. Therefore, the contents of the image buffer are also moved up by 4 pixels, and the data for the additional 4 pixels are acquired from the image data input terminal and stored in the image buffer. In the figure, for convenience of explanation, the image data is represented as being moved. However, if the image buffer is configured as a ring buffer, the movement of the image data in the buffer can be processed only by changing the address counter. Because it is convenient. Next, an AND operation is performed for each pixel of the second mask pattern 34 generated from the mask generation unit 13 and the image buffer 11 according to a procedure described later to generate a head drive signal 35.
[0170]
FIG. 29C is a diagram illustrating mask processing for generating a print head control signal in the third scan. After the second scanning is performed, the transport unit 103 feeds the paper by 1/4 of the number of recording elements, that is, four pixels. Therefore, the contents of the image buffer are also moved up by 4 pixels, and the data for the additional 4 pixels are acquired from the image data input terminal and stored in the image buffer. Next, an AND operation is performed for each pixel of the third mask pattern 36 generated from the mask generation unit 13 and the image buffer 11 by means described later to generate a head drive signal.
[0171]
FIG. 29D is a diagram illustrating mask processing for generating a print head control signal in the fourth scan. After the third scan is performed, the transport unit 103 feeds the paper by 1/4 of the number of recording elements, that is, four pixels. Therefore, the contents of the image buffer are also moved up by 4 pixels, and the data for the additional 4 pixels are acquired from the image data input terminal and stored in the image buffer. Next, an AND operation is performed for each pixel of the image mask 11 and the fourth mask pattern 38 generated from the mask generation unit 13 by means to be described later to generate a head drive signal.
[0172]
With the above four scans, the image printing process for the four pixels at the upper end of the image is completed. Thereafter, the same processing is repeated to print the entire image. In the fifth scan, since printing for the upper four pixels of the image has already been completed, the data for the upper four pixels of the image buffer is discarded, and the data for the additional four pixels is newly created in the free space. Store.
[0173]
Next, a procedure for generating mother mask data will be described with reference to the flowchart of FIG.
In this embodiment, the size of the mother mask is 16 pixels vertically and horizontally. First, one dot arrangement at the first level is determined at random (step S40). Here, the first dot position is (x0, y0). Next, the mother mask data is initialized (step S41). That is, the mask value of the first dot position (x0, y0) is set to 254, and the other mask values are set to 255. Next, potential initialization is performed (step S42). The potential is given by the following function f (r) with respect to the distance r from the dot position.
[0174]
f (r) = − 0.41r + 1.21 (r <2)
f (r) = 2.76exp (−r) (2 ≦ r <10)
f (r) = 0 (r ≧ 10)
Accordingly, the potential P (x, y) with respect to the mask position (x, y) based on the dot position (x0, y0) is obtained by the following equation.
[0175]
[Expression 1]

[0176]
FIG. 32 shows the shape of the potential. By giving such a repulsive potential to the dot position, it is possible to prevent a new dot from being generated in the vicinity of the already generated dot. If the potential skirt exceeds the mask area, the calculation is performed by folding back to the opposite side of the mask area as shown in FIG. This is because the discontinuity of the dot arrangement does not occur at the mask boundary.
Next, a position having the smallest potential is searched and a dot is added at that position (step S43). When there are a plurality of positions having the minimum potential value, one position is selected at random. Next, the mask value corresponding to the positions of all the dots including the newly added dot is reduced by 1 (step S44). Next, the potential for the newly added dot is added (step S45). If the position of the added dot is (x1, y1), a new potential is obtained by the following equation.
[0177]
[Expression 2]

[0178]
Steps S43, S44, and S45 are repeated until dots are added to all pixel positions of the mother mask. The generation of the mother mask is performed as described above. By such a procedure, a visually preferable pseudo-periodic mask pattern in which mask values are uniformly distributed can be generated. The means for generating the mother mask does not need to be incorporated in the image recording apparatus, and the mother mask data is generated in advance by a separate mother mask generating apparatus, and only the resulting mother mask data is stored in the mother mask memory. It shall be.
In addition, if the numerical formula applied in this embodiment is a similar numerical formula, it does not need to be specifically limited.
[0179]
Next, a procedure for generating mask data 32, 34, 36, and 38 stored in the mask buffer 14 by the mask generation unit 13 will be described with reference to the flowchart of FIG. The mother mask has 16 pixels vertically and horizontally, and each mask value has a value from 0 to 255. First, the mask data is quantized into the number of multipass scans (step S50). That is, in the present embodiment, since multi-pass printing is performed by four scans, the mask values 0 to 63 are the first pass, the mask values 64 to 127 are the second pass, and the mask values 128 to 191 are the third pass. The mask values 192 to 255 are assigned to the fourth pass. Next, the pixel of the mask data corresponding to each pass is turned on (step S52). That is, the pixel position assigned to the first pass of the mask data 32 of the first pass is turned on, the pixel position assigned to the second pass of the mask data 34 of the second pass is turned on, and the mask data of the third pass is turned on. The pixel positions assigned to the third pass 36 are turned on, and the pixel positions assigned to the fourth pass of the mask data 38 of the fourth pass are turned on. Next, the mask data is rotated corresponding to the transport amount in each pass (step S52). That is, the mask data 34 is rotated up by 4 pixels, the mask data 36 is rotated up by 8 pixels, and the mask data 38 is rotated up by 12 pixels.
[0180]
With the configuration as described above, by using a mother mask of a pseudo-periodic array with high dispersibility of dots, a repetitive pattern that occurs when random numbers with a short period are used, or a granularity that occurs when a mask with uniform random numbers is used Sexual deterioration can be prevented. The mask pattern generated by the above means is hereinafter defined as a quasi-periodic array mask pattern.
[0181]
Here, a case will be described in which the same scanning area E (pass area) is divided into two parts and the recording duties in the divided areas e1 and e2 are different as shown in FIG. By using such a divided duty, the banding is difficult to see in terms of visual characteristics. FIGS. 13A, 13B, and 14C show examples of setting the recording duty of the divided areas e1 and e2. FIG. 15A shows an image in which the divided areas e1 and e2 are formed with a uniform duty, and FIG. 15B shows an image formed with the two divided duties. When any of the images is formed by reciprocating the carriage, the color unevenness due to the difference in the driving order is noticeable as shown in the above schematic diagram. In FIG. 34, H100T indicates a plurality of nozzle groups for recording each pass area E, and each nozzle group is constituted by (four in the figure) nozzles n.
[0182]
Here, in the image formed with the uniform duty shown in FIG. 14A described above, for example, when a uniform solid pattern is recorded, banding occurs at the paper feed pitch. At a pitch about this paper feed pitch, the presence of banding is perceived in terms of visual characteristics, and the image quality is degraded. However, in this third embodiment as well, as in the first and second embodiments, banding occurs at half the paper feed pitch. It fits within the perceived pitch and does not feel image quality degradation. According to the experiment by the present inventor, it has been confirmed that, with a pitch of 338 μm, color unevenness (banding) due to a driving order difference or the like is difficult to be recognized in terms of visual characteristics. However, no significant effect was observed even if the pitch was further reduced. As for the number of divisions, for example, in the case of four-pass recording, the effect of reducing image degradation appears significantly when each pass area is divided into four.
[0183]
Furthermore, it has been confirmed that the mask pattern generated by the conventional random function is drastically improved in terms of graininess and mask periodicity (texture).
[0184]
As described above, when a certain area E is recorded by multi-pass recording, it can be said that it is more preferable for reciprocal recording to subdivide the recording duty setting area as the number of passes decreases. Note that this recording duty can be selected and set in accordance with various media characteristics (absorbency, bleeding) as optimum values for the number of multipasses and the number of divisions. This can be realized by storing it in a mask table in advance and reading it out according to the above conditions.
[0185]
(Fourth embodiment)
Next, an ink jet recording apparatus and an ink jet recording method according to a fourth embodiment of the present invention will be described.
In the fourth embodiment, the recording duty of the divided areas e1 and e2 of the recording head in the same pass area E formed by the main scanning is the same as the generation means shown in the third embodiment. Is set to a value smaller than the recording duty of the divided areas located inside the divided areas e1 and e2 corresponding to both ends thereof.
[0186]
That is, as shown in FIG. 17 (a), in the case of normal four-pass printing (in-pass division number 1) conventionally performed, each nozzle row is divided into four pass areas E, and printing in each printing area E is performed. Although the duty is 25%, in this embodiment, as shown in FIG. 17B, each pass area E is divided into two to set divided areas e1 and e2 and nozzles at both ends of the print head H1001. The recording duty of the divided areas e1 and e2 corresponding to n is set to a lower value (6.25%) than the other divided areas e1 and e2, and the recording duty in each pass area is 18.75% to The distribution is up to 31.25%.
By setting the recording duty at e1 and e2 in this way, the frequency of use of the nozzles n positioned at both ends of the recording head is reduced, and the number of occurrences of end deviation can be reliably suppressed. Can be reduced. This white streak suppression effect becomes apparent when an image formed in the second embodiment (see FIG. 19) is compared with an image formed by conventional four-pass printing (see FIG. 18).
[0187]
The image shown in FIG. 18 is an image formed by setting the recording duty for each pass area E to a uniform value (25% duty). As shown in the figure, in this image, end deviation occurs in 1 out of 4 dots (25%), and the occurrence of this end deviation is more noticeable when the number of multipaths is further reduced. This is clearly recognized as a white streak.
On the other hand, the image shown in FIG. 19 is the same four-pass printing, and as shown in FIG. 17B, the recording duty of the divided areas e1 and e2 at the end is 6.25% (1 of the conventional uniform duty). / 4) and the recording duty is set to be higher in the region closer to the center of the recording head H1001.
In this way, by setting the recording duty of the edge to a low value, the edge deviation in the image occurs at an extremely low frequency of 1 dot out of 16 dots, and the edge deviation is recognized as a white stripe. It will not be. Therefore, in addition to eliminating the bundle in the image in the same manner as in the first embodiment, it is also possible to eliminate the occurrence of white streaks due to the edge twist, and to obtain a higher quality image.
[0188]
In the second embodiment, the case where the path area E is divided into two parts is described as an example. However, the number of divisions may be three or more. For example, FIG. 35A shows a uniform mask pattern with a recording duty of 25% in all the divided areas e1, e2, e3, and e4. On the other hand, as shown in FIG. 35 (b), the recording duty of the divided areas e1 and e4 located at both ends is set to a relatively low value of 6.25%, and the divided area is also the recording head here. It is set to a higher value as it goes inward. In FIG. 35A, since the recording duty is a uniform mask pattern of 25%, it is not always necessary to divide as described above.
[0189]
In FIG. 35 (b), M1 is a pseudo-periodic array mask pattern for setting the recording duty, and M in FIG. 35 (a) is a pseudo-periodic array mask for performing 4-pass recording at a uniform duty. Each pattern is shown schematically. As is apparent from the drawing, the mask pattern M1 is in a state in which the concentrated dots d1 are more dispersed as it moves toward the end.
[0190]
As described above, according to the third embodiment and the fourth embodiment, by generating a mask pattern having a visually preferable dot arrangement in a quasi-periodic arrangement, compared to a mask pattern using random numbers, Generation of repetitive patterns and graininess can be further reduced.
[0191]
In addition, one form in which the present invention is effectively used is a form in which bubbles are formed by causing film boiling in a liquid using thermal energy generated by an electrothermal transducer.
[0192]
【The invention's effect】
As described above, according to the present invention, the same recording area recorded in each recording scan is divided and the recording duty in the divided area is made different. The generation region can be shortened, and an excellent effect on the viewing angle characteristic can be obtained.
Further, among the same area formed by each main scanning, the recording duty for the divided areas located at both ends is set to a value smaller than the recording duty of the divided area located inside thereof, and is set at both ends of the recording head. Since the frequency of use of the nozzles at the position is suppressed, the number of occurrences of the landing position deviation of the droplets at the end nozzles can be reduced, and better image quality can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external configuration of an inkjet printer according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a state where an exterior member of the printer shown in FIG. 1 is removed.
FIG. 3 is a perspective view showing a state in which a recording head cartridge used in the printer according to the embodiment of the invention is assembled.
4 is an exploded perspective view showing the recording head cartridge shown in FIG. 3. FIG.
5 is an exploded perspective view of the recording head shown in FIG. 4 as viewed obliquely from below.
6A and 6B show the scanner cartridge upside down in order to show the configuration of the scanner cartridge that can be mounted on the printer according to the embodiment of the present invention instead of the recording head cartridge of FIG. It is a perspective view.
FIG. 7 is a block diagram schematically showing an overall configuration of an electric circuit in the printer according to the embodiment of the present invention.
8 is a block diagram showing an internal configuration example of a main PCB in the electric circuit shown in FIG.
9 is a block diagram showing an internal configuration example of an ASIC in the main PCB shown in FIG. 8. FIG.
FIG. 10 is a flowchart illustrating an operation example of a printer according to an embodiment of the present invention.
FIG. 11 is a plan view schematically showing a recording head in the first embodiment of the invention.
FIG. 12 is a block diagram illustrating an image processing unit according to the first embodiment of the present invention.
13A and 13B are diagrams showing recording duty in each pass in the 4-pass printing in the embodiment. FIG. 13A shows a case where printing is performed with a uniform duty (25%) in each scanning recording area, and FIG. A case where the recording duty of the scanning recording area is different is shown.
14A and 14B are diagrams showing the recording duty in each pass in the 4-pass printing in the embodiment, where FIG. 14A shows a case where a uniform duty is set, and FIG. 14B shows a recording duty in each divided area in each pass. The case where is set to a different value is shown.
15A is a schematic diagram showing a random master pattern used for normal four-pass printing in the embodiment, and FIG. 15B is a schematic diagram showing a random master pattern used for four-pass printing in the embodiment. is there.
FIG. 16 is a schematic diagram of an image formed by four-pass printing in the embodiment, and shows a case where each pass area is divided into two and the print duty in each area is set to a different value.
FIGS. 17A and 17B are diagrams showing recording duty in each pass in four-pass printing in the embodiment, where FIG. 17A shows a case where a uniform duty is set, and FIG. 17B shows a recording duty in each divided area in each pass; The case where is set to a different value is shown.
18A and 18B are schematic diagrams of an image formed by four-pass printing in the embodiment, in which FIG. 18A shows the case where each pass area is formed with a uniform recording duty, and FIG. 18B shows the inside of each pass area. Are divided into two, and the recording duty in each region is set to a different value.
FIG. 19 is a schematic diagram showing an image in which only the end of the recording area is formed with a recording duty of 6.25% in the 4-pass recording in the embodiment.
20A is a diagram schematically showing a random mask pattern when 4-pass printing is performed with a uniform duty, and FIG. 20B is a diagram schematically showing a random mask pattern for setting different printing duties.
FIG. 21 is a block diagram showing a detailed configuration of a path number determination unit in the embodiment;
FIG. 22 is a diagram showing an example in which an image composed of a plurality of color areas is recorded on a one-page recording medium in the embodiment.
FIG. 23 is a flowchart when the number of passes is determined based on a threshold value determined based on the standard deviation of the deviation in the embodiment.
FIG. 24 is a block diagram showing another functional configuration example of image processing in the embodiment.
FIG. 25 is a diagram illustrating an example in which black characters and natural images are mixed in an image recorded on a recording medium of one page in the embodiment.
FIG. 26 is a block diagram showing still another functional configuration example of image processing in the embodiment.
FIG. 27 is a block diagram illustrating a configuration of an image recording apparatus according to a third embodiment of the present invention.
FIG. 28 is a diagram illustrating a configuration example of a recording head according to a third embodiment of the invention.
FIG. 29 is a diagram illustrating a procedure for generating a printhead control signal from an image buffer and a mask buffer by a mask processing unit according to the embodiment; FIG. 29A is a view for generating a printhead control signal in a first scan. The figure which showed the mask process, (b) The figure which showed the mask process for producing | generating the recording head control signal in 2nd scanning, (c) The mask process for producing | generating the recording head control signal in 3rd scanning FIG. 8D is a diagram showing a mask process for generating a printhead control signal in the fourth scan.
FIG. 30 is a flowchart showing a generation procedure of mother mask data in the embodiment.
FIG. 31 is a flowchart showing a procedure for generating mask data stored in the mask buffer by the mask processing unit in the embodiment;
FIG. 32 is a diagram showing a potential with respect to a mask position in the embodiment.
FIG. 33 is an explanatory diagram showing a calculation method when the potential skirt exceeds the mask region in the embodiment;
FIG. 34 is a schematic diagram of an image formed by four-pass printing in the embodiment, in which each pass area is divided into two, and the recording duty in each area is set to a different value using a quasi-periodic array mask pattern. FIG.
FIG. 35A is a diagram schematically showing a quasi-periodic array mask pattern in the case where one pass area is divided into four and four pass printing is performed with the recording duty of each pass area being a uniform duty. FIG. 6 is a diagram schematically showing a state in which one pass area is divided into four and the recording duty of each pass area is set to a different value, and a quasi-periodic mask pattern in that state.
36A is a schematic diagram showing an appropriate ejection state of ink droplets ejected from a recording head, and FIG. 36B shows an image without droplet density unevenness obtained by ejection of ink droplets in FIG. Schematic (c) is a diagram showing the density distribution of the image shown in (b).
FIG. 37A is a schematic diagram showing a variation state of ink droplets ejected from a recording head, and FIG. 37B shows an image with droplet density unevenness obtained by ejecting ink droplets in FIG. Schematic (c) is a diagram showing the density distribution of the image shown in (b).
FIG. 38 is a diagram showing a case where multi-pass printing (two-pass printing) is performed in the embodiment, wherein (a) is a schematic diagram showing an ejection state of ink droplets ejected from a recording head, and (b). FIG. 4A is a schematic diagram showing an image in which droplet density unevenness is obtained by ejecting ink droplets in FIG. 4A, and FIG. 3C is a diagram showing the density distribution of the image shown in FIG.
FIG. 39 is a diagram showing an image formed by multi-pass printing (two-pass printing) in the embodiment, wherein (a) shows an image formed in the first pass, and (b) shows a second pass. (C) shows an image formed in the third pass.
FIG. 40 is a plan view schematically showing a recording head.
FIG. 41 is a schematic diagram showing a state in which a phenomenon of edge stagnation of a droplet viewed from the recording head side occurs.
[Explanation of symbols]
M1000 main unit
M1001 Lower case
M1002 Upper case
M1003 Access cover
M1004 discharge tray
M2015 Paper gap adjustment lever
M2003 Paper discharge roller
M3001 LF roller
M3019 chassis
M3022 Automatic feeding section
M3029 transport section
M3030 discharge section
M4000 recording unit
M4001 Carriage
M4002 Carriage cover
M4007 Headset lever
M4021 Carriage shaft
M5000 recovery unit
M6000 scanner
M6001 Scanner holder
M6003 Scanner cover
M6004 Scanner contact PCB
M6005 Scanner illumination lens
M6006 Scanner reading lens 1
M6100 storage box
M6101 storage box base
M6102 Storage box cover
M6103 Storage box cap
M6104 Storage box spring
E0001 Carriage motor
E0002 LF motor
E0003 PG motor
E0004 Encoder sensor
E0005 Encoder Scale
E0006 Ink end sensor
E0007 PE sensor
E0008 GAP sensor (Paper gap sensor)
E0009 ASF sensor
E0010 PG sensor
E0011 Contact FPC (Flexible Print Cable)
E0012 CRFFC (flexible flat cable)
E0013 Carriage board
E0014 main board
E0015 Power supply unit
E0016 Parallel I / F
E0017 Serial I / F
E0018 Power key
E0019 Resume key
E0020 LED
E0021 Buzzer
E0022 Cover sensor
E1001 CPU
E1002 OSC (CPU built-in oscillator)
E1003 A / D (A / D converter with built-in CPU)
E1004 ROM
E1005 Oscillator circuit
E1006 ASIC
E1007 Reset circuit
E1008 CR motor driver
E1009 LF / PG motor driver
E1010 Power supply control circuit
E1011 INKS (ink end detection signal)
E1012 TH (Thermistor temperature detection signal)
E1013 HSENS (Head detection signal)
E1014 Control bus
E1015 RESET (Reset signal)
E1016 RESUME (resume key input)
E1017 POWER (Power key input)
E1018 BUZ (Buzzer signal)
E1019 Oscillator circuit output signal
E1020 ENC (encoder signal)
E1021 Head control signal
E1022 VHON (Head power ON signal)
E1023 VMON (motor power ON signal)
E1024 Power control signal
E1025 PES (PE detection signal)
E1026 ASFS (ASF detection signal)
E1027 GAPS (GAP detection signal)
E0028 Serial I / F signal
E1029 Serial I / F cable
E1030 Parallel I / F signal
E1031 Parallel I / F cable
E1032 PGS (PG detection signal)
E1033 PM control signal (pulse motor control signal)
E1034 PG motor drive signal
E1035 LF motor drive signal
E1036 CR motor control signal
E1037 CR motor drive signal
E0038 LED drive signal
E1039 VH (head power supply)
E1040 VM (motor power supply)
E1041 VDD (logic power supply)
E1042 COVS (Cover detection signal)
E2001 CPU I / F
E2002 PLL
E2003 DMA controller
E2004 DRAM controller
E2005 DRAM
E2006 1284 I / F
E2007 USB I / F
E2008 Reception control unit
E2009 Compression / decompression DMA
E2010 Receive buffer
E2011 Work buffer
E2012 Work area DMA
E2013 Recording buffer transfer DMA
E2014 Print buffer
E2015 Recording data expansion DMA
E2016 Data buffer for decompression
E2017 Column buffer
E2018 Head control unit
E2019 Encoder signal processor
E2020 CR motor controller
E2021 LF / PG motor controller
E2022 Sensor signal processor
E2023 Motor control buffer
E2024 Scanner capture buffer
E2025 Scanner data processing DMA
E2026 Scanner data buffer
E2027 Scanner data compression DMA
E2028 Sending buffer
E2029 Port control unit
E2030 LED controller
E2031 CLK (clock signal)
E2032 PDWM (software control signal)
E2033 PLLON (PLL control signal)
E2034 INT (interrupt signal)
E2036 PIF received data
E2037 USB reception data
E2038 WDIF (received data / raster data)
E2039 Reception buffer control unit
E2040 RDWK (Reception buffer read data / raster data)
E2041 WDWK (work buffer write data / record code)
E2042 WDWF (Workfill data)
E2043 RDWP (work buffer read data / record code)
E2044 WDWP (Sort recording code)
E2045 RDHDG (data for recording development)
E2047 WDHDG (column buffer write data / development record data) E2048 RDHD (column buffer read data / development record data)
E2049 Head drive timing signal
E2050 Data development timing signal
E2051 RDPM (pulse motor drive table read data)
E2052 Sensor detection signal
E2053 WDHD (captured data)
E2054 RDAV (acquisition buffer read data)
E2055 WDAV (data buffer write data / processed data)
E2056 RDYC (data buffer read data / processed data)
E2057 WDYC (send buffer write data / compressed data)
E2058 RDUSB (USB transmission data / compressed data)
E2059 RDPIF (1284 transmission data)
H1000 recording head cartridge
H1001 Recording head
H1100 recording element substrate
H1100T Discharge port
H1200 first plate
H1201 Ink supply port
H1300 Electric wiring board
H1301 External signal input terminal
H1400 second plate
H1500 tank holder
H1501 ink flow path
H1600 flow path forming member
H1700 filter
H1800 seal rubber
H1900 ink tank
n Nozzle
N Nozzle group

Claims (20)

A recording head formed by arranging a plurality of nozzles is scanned a predetermined recording area on a recording medium a plurality of times, and a thinned image is recorded using different nozzle groups of the recording head in each of the plurality of scannings. An inkjet recording apparatus for completing an image to be recorded in the predetermined recording area,
Image data to be recorded in each of the plurality of scans is generated by thinning out the image data corresponding to the predetermined recording area using a plurality of thinning mask patterns corresponding to the nozzle groups used in each of the plurality of scans. Means to
A recording control unit configured to record the thinned image based on the generated image data using a nozzle group facing the predetermined recording area in each of the plurality of scans;
Each of the plurality of thinning mask patterns has a recording pixel and a non-recording state so that the ratio of the recording pixel is smaller in the portion corresponding to the nozzle closer to the end than in the portion corresponding to the nozzle closer to the center of the nozzle array. The pixels are arranged,
The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzle of the recording head is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group not including the end nozzle. An ink jet recording apparatus. By scanning a predetermined recording area on a recording medium a plurality of times with a recording head formed by arranging a plurality of nozzles, and recording a thinned image using different nozzles of the recording head in each of the plurality of scans An inkjet recording apparatus for completing an image to be recorded in the predetermined recording area,
In order to make each of a plurality of nozzle groups obtained by dividing the plurality of nozzles by a predetermined number of units face the predetermined recording area in each of the plurality of scans, the recording is performed by an amount corresponding to a single nozzle group. Conveying means for conveying the medium;
Recording is performed by each nozzle group in each of the plurality of scans by thinning out image data corresponding to the predetermined recording area using a plurality of thinning mask patterns corresponding to the nozzle groups used in each of the plurality of scans. Means for generating image data to be
In each of the plurality of scans, a recording control unit that records the thinned image based on the generated image data using a nozzle group facing the predetermined recording area,
Each of the plurality of thinning mask patterns is formed by arranging recording pixels and non-recording pixels so that the ratio of recording pixels decreases along the nozzle array from the center side to the end side of the array.
The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzle of the recording head is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group not including the end nozzle. An inkjet recording apparatus. The thinning mask pattern includes a first portion corresponding to the nozzle on the end portion side and a second portion corresponding to the nozzle on the center portion side,
The inkjet recording apparatus according to claim 2, wherein a ratio of recording pixels in the first portion is smaller than a ratio of recording pixels in the second portion.   The ratio of the recording pixels in the second portion in the thinning mask pattern corresponding to the nozzle group including the end nozzle is the first in the thinning mask pattern corresponding to the nozzle group not including the end nozzle. The inkjet recording apparatus according to claim 3, wherein the ratio is larger than a ratio of recording pixels in the portion.   3. The ink jet recording apparatus according to claim 1, wherein the thinning mask pattern is a quasi-periodic array in which the non-recording pixels and the recording pixels are uniformly distributed. The image recording apparatus further includes a stripe unevenness detection unit that detects a stripe unevenness amount of an image recorded using the recording head.
The amount of streak detection means includes a control unit that records a predetermined test image with a recording head, a reading unit that reads the recorded test image using an optical sensor, and a recording head based on the reading result. 6. The ink jet recording apparatus according to claim 1, further comprising: a calculation unit that obtains an amount of streaks and a register that stores a calculation result of the calculation unit.   7. The ink jet recording apparatus according to claim 1, wherein the recording head has an amount of ink ejected from each nozzle by one ejection operation of 4 pl or less.   8. The ink jet recording apparatus according to claim 1, wherein the recording head has an average dot diameter of 50 [mu] m or less by ink ejected from each nozzle by one ejection operation.   9. The ink jet recording apparatus according to claim 1, wherein the recording head has nozzles arranged at a density of 600 dpi or more. By scanning a predetermined recording area of a recording medium a plurality of times with a recording head formed by arranging a plurality of nozzles, and recording a thinned image using different nozzle groups of the recording head in each of the plurality of scannings An inkjet recording apparatus for completing an image to be recorded in the predetermined recording area,
Conveying means for conveying the recording medium by an amount corresponding to the width in the nozzle arrangement direction in the predetermined recording area in order to make the different nozzle groups face the predetermined recording area in each of the plurality of scans;
Image data to be recorded in each of the plurality of scans is generated by thinning out the image data corresponding to the predetermined recording area using a plurality of thinning mask patterns corresponding to the nozzle groups used in each of the plurality of scans. Means to
In each of the plurality of scans, a recording control unit that records the thinned image based on the generated image data using a nozzle group facing the predetermined recording area,
Each of the plurality of thinning mask patterns has a recording rate that decreases from the center side to the end side of the array along the nozzle array,
The recording rate of the thinning mask pattern corresponding to the nozzle group including the end nozzles of the recording head is smaller than the recording rate of the thinning mask pattern corresponding to the nozzle group not including the end nozzle. An inkjet recording apparatus.   The inkjet recording apparatus according to claim 10, wherein the recording rate of the thinning mask pattern is a ratio of recording pixels to recording pixels and non-recording pixels constituting the thinning mask pattern. By scanning a predetermined recording area of a recording medium a plurality of times with a recording head formed by arranging a plurality of nozzles, and recording a thinned image using different nozzle groups of the recording head in each of the plurality of scannings An inkjet recording apparatus for completing an image to be recorded in the predetermined recording area,
A thinning mask pattern in which recording pixels and non-recording pixels are arranged, and a memory storing a plurality of the thinning mask patterns corresponding to the nozzle groups used in each of the plurality of scans;
Means for generating image data to be recorded by different nozzle groups in each of the plurality of scans based on image data corresponding to the predetermined recording area and a plurality of thinning mask patterns read from the memory;
In each of the plurality of scans, a recording control unit that records the thinned image based on the generated image data using a nozzle group facing the predetermined recording area,
Each of the plurality of thinning mask patterns corresponds to a small nozzle group relatively far from the central nozzle of the recording head as a plurality of portions corresponding to each of the small nozzle groups obtained by dividing the single nozzle group. The first portion and at least a second portion corresponding to a small nozzle group that is relatively close to the central nozzle, and the ratio of recording pixels in the first portion is the ratio of recording pixels in the second portion. Less than,
The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzles of the recording head is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the central nozzle. An ink jet recording apparatus. A recording head formed by arranging a plurality of nozzles is scanned twice with respect to a predetermined recording area of the recording medium, and a thinned image is recorded by using different nozzle groups of the recording head in each of the two scans. An inkjet recording apparatus for completing an image to be recorded in the predetermined recording area,
A thinning mask pattern in which recording pixels and non-recording pixels are arranged, and a memory storing the two thinning mask patterns corresponding to the nozzle groups used in each of the two scans;
Means for generating image data to be recorded by different nozzle groups in each of the two scans based on the image data corresponding to the predetermined recording area and the two thinning mask patterns read from the memory;
A recording control means for recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area in each of the two scans;
Each of the two thinning mask patterns includes a recording pixel and a non-recording pixel so that the ratio of the recording pixel gradually decreases in a plurality of stages along the nozzle array from the center to the end of the array. Arranged,
The inkjet recording apparatus characterized in that the plurality of stages are three or more stages. A recording head formed by arranging a plurality of nozzles is scanned twice with respect to a predetermined recording area on the recording medium, and a thinned image is recorded using different nozzle groups of the recording head in each of the two scans. An inkjet recording apparatus for completing an image to be recorded in the predetermined recording area,
The recording medium is transported by an amount corresponding to a single nozzle group so that each of the two nozzle groups obtained by dividing the plurality of nozzles into two faces the predetermined recording area in each of the two scans. Conveying means for
Recording is performed by each nozzle group in each of the two scans by thinning out image data corresponding to the predetermined recording area using two thinning mask patterns corresponding to the nozzle groups used in each of the two scans. Means for generating image data to be
A recording control means for recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area in each of the two scans;
In each of the two thinning mask patterns, the recording pixels and the non-recording pixels are arrayed so that the ratio of the recording pixels gradually decreases in a plurality of stages along the nozzle array from the center to the end of the array. Being
The inkjet recording apparatus characterized in that the plurality of stages are three or more stages. A recording head formed by arranging a plurality of nozzles is scanned a predetermined recording area on a recording medium a plurality of times, and a thinned image is recorded using different nozzle groups of the recording head in each of the plurality of scannings. By the inkjet recording method of completing an image to be recorded in the predetermined recording area,
Image data to be recorded in each of the plurality of scans is generated by thinning out the image data corresponding to the predetermined recording area using a plurality of thinning mask patterns corresponding to the nozzle groups used in each of the plurality of scans. And a process of
Recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area in each of the plurality of scans,
Each of the plurality of thinning mask patterns has a recording pixel and a non-recording state so that the ratio of the recording pixel is smaller in the portion corresponding to the nozzle closer to the end than in the portion corresponding to the nozzle closer to the center of the nozzle array. The pixels are arranged,
The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzle of the recording head is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group not including the end nozzle. An inkjet recording method characterized by the above. By scanning a predetermined recording area on a recording medium a plurality of times with a recording head formed by arranging a plurality of nozzles, and recording a thinned image using different nozzles of the recording head in each of the plurality of scans An inkjet recording method for completing an image to be recorded in the predetermined recording area,
In order to make each of a plurality of nozzle groups obtained by dividing the plurality of nozzles by a predetermined number of units face the predetermined recording area in each of the plurality of scans, the recording is performed by an amount corresponding to a single nozzle group. A transporting process for transporting the medium;
Recording is performed by each nozzle group in each of the plurality of scans by thinning out image data corresponding to the predetermined recording area using a plurality of thinning mask patterns corresponding to the nozzle groups used in each of the plurality of scans. Generating image data to be processed;
Recording the thinned image based on the generated image data using a nozzle group facing the predetermined recording area in each of the plurality of scans,
Each of the plurality of thinning mask patterns is formed by arranging recording pixels and non-recording pixels so that the ratio of recording pixels decreases along the nozzle array from the center side to the end side of the array.
The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzle of the recording head is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group not including the end nozzle. An inkjet recording method. By scanning a predetermined recording area of a recording medium a plurality of times with a recording head formed by arranging a plurality of nozzles, and recording a thinned image using different nozzle groups of the recording head in each of the plurality of scannings An inkjet recording method for completing an image to be recorded in the predetermined recording area,
A transporting step of transporting the recording medium by an amount corresponding to the width in the nozzle arrangement direction in the predetermined recording area in order to make the different nozzle group face the predetermined recording area in each of the plurality of scans;
Image data to be recorded in each of the plurality of scans is generated by thinning out the image data corresponding to the predetermined recording area using a plurality of thinning mask patterns corresponding to the nozzle groups used in each of the plurality of scans. And a process of
In each of the plurality of scans, using a nozzle group facing the predetermined recording area, and recording the thinned image based on the generated image data,
Each of the plurality of thinning mask patterns has a recording rate that decreases from the center side to the end side along the nozzle array,
The recording rate of the thinning mask pattern corresponding to the nozzle group including the end nozzles of the recording head is smaller than the recording rate of the thinning mask pattern corresponding to the nozzle group not including the end nozzle. An inkjet recording method. By scanning a predetermined recording area of a recording medium a plurality of times with a recording head formed by arranging a plurality of nozzles, and recording a thinned image using different nozzle groups of the recording head in each of the plurality of scannings An inkjet recording method for completing an image to be recorded in the predetermined recording area,
A thinning mask pattern in which recording pixels and non-recording pixels are arranged, and the thinning mask pattern from a memory storing a plurality of the thinning mask patterns corresponding to the nozzle groups used in each of the plurality of scans A process of reading
Generating image data to be recorded by different nozzle groups in each of the plurality of scans based on image data corresponding to the predetermined recording area and a plurality of thinning mask patterns read from the memory;
In each of the plurality of scans, using the nozzle group facing the predetermined recording area, the step of recording the thinned image based on the generated image data,
Each of the plurality of thinning mask patterns corresponds to a small nozzle group relatively far from the central nozzle of the recording head as a plurality of portions corresponding to each of the small nozzle groups obtained by dividing the single nozzle group. The first portion and at least a second portion corresponding to a small nozzle group that is relatively close to the central nozzle, and the ratio of recording pixels in the first portion is the ratio of recording pixels in the second portion. Less than,
The ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the end nozzles of the recording head is smaller than the ratio of the recording pixels of the thinning mask pattern corresponding to the nozzle group including the central nozzle. An ink jet recording method. A recording head formed by arranging a plurality of nozzles is scanned twice with respect to a predetermined recording area of the recording medium, and a thinned image is recorded using different nozzle groups of the recording head in the two scans, An inkjet recording method for completing an image to be recorded in the predetermined recording area,
A thinning mask pattern in which recording pixels and non-recording pixels are arranged, and the thinning mask pattern from a memory storing two thinning mask patterns corresponding to the nozzle groups used in each of the two scans A process of reading
Generating image data to be recorded by different nozzle groups in each of the two scans based on image data corresponding to the predetermined recording area and two thinning mask patterns read from the memory;
In each of the two scans, using the nozzle group facing the predetermined recording area, the step of recording the thinned image based on the generated image data,
In each of the two thinning mask patterns, the recording pixels and the non-recording pixels are arrayed so that the ratio of the recording pixels gradually decreases in a plurality of stages along the nozzle array from the center side to the end side of the array. Being
The inkjet recording method, wherein the plurality of stages are three or more stages. By causing a recording head formed by arranging a plurality of nozzles to scan a predetermined recording area on a recording medium twice and recording a thinned image using different nozzle groups of the recording head in the two times of scanning. An inkjet recording method for completing an image to be recorded in the predetermined recording area,
The recording medium is transported by an amount corresponding to a single nozzle group so that each of the two nozzle groups obtained by dividing the plurality of nozzles into two faces the predetermined recording area in each of the two scans. And the process of
Recording is performed by each nozzle group in each of the two scans by thinning out image data corresponding to the predetermined recording area using two thinning mask patterns corresponding to the nozzle groups used in each of the two scans. Generating image data to be processed;
In each of the two scans, using the nozzle group facing the predetermined recording area, the step of recording the thinned image based on the generated image data,
In each of the two thinning mask patterns, the recording pixels and the non-recording pixels are arrayed so that the ratio of the recording pixels gradually decreases in a plurality of stages along the nozzle array from the center to the end of the array. Being
The inkjet recording method, wherein the plurality of stages are three or more stages.

Images