JP5164303B2 - RECORDING DEVICE, IMAGE PROCESSING DEVICE, DATA GENERATION METHOD, COMPUTER PROGRAM, AND RECORDING SYSTEM - Google Patents

Description

【０１１４】
ｉ：Ｘ方向の画素位置
ｊ：Ｙ方向の画素位置
Ｎ：画像ＰのＸ方向およびＹ方向のサイズ
【０１１５】
次に、このようなGranularity評価値（Ｇ）と被験者テストとの相関関係を求 めた。測定に使用したプリンタは、Canon製BJF-850(6色濃淡インクジェットプリンタ、解像度1200dpi×1200dpi、ドット径40μｍ)、ドラムスキャナはHowtek製ScanMaster4500である。本測定では、プリンタによって、均一濃度パッチ(グレースケール５０％)をＫ（ブラック）インクを用いて出力し、解像度を１０００ｄｐｉとしたドラムスキャナによって、その出力画像を読み取った。そのドラムスキャナによる入力画像を1024×1024[pixels]に切り取り、それをGranularity評 価関数を用いて評価した。図２５は、その評価結果である。
【０１１６】
図２５のGranularity評価値（Ｇ）と被験者テストの結果から、図１６中の濃度領域Ａの評価値を0.6以下に抑える必要があることが分かった。より好ましくは、0.4以下に抑えることにより、全濃度領域に渡って粒状感を小さくすることが可能となる。
【０１１７】
また、インクの濃度を決定する際にも、 Granularity評価関数をそのまま使用することができる。例えば、淡インクの濃度を決定する場合、淡インクの濃度を１／３、１／４、１／５、１／６と希釈して、ハイライト部においてドットが見えるか否か、中濃度部において濃インクのドットが見えるか否か判断材料として、主観評価とGranularity値を併用する。これにより、ハイライト部と中濃度部の粒状感を総合的に考慮して、インクの濃度を決定することが可能となる。
【０１１８】
Granularity評価関数を使用して、全濃度領域に渡って粒状感が小さな値(Granularity値0.4以下)になるように、インクの濃度とドット径を検討した。その結果、本例のような6色濃淡インクジェットプリンタにおいては、ドット径30μm( 吐出量2pl；ただしにじみ率約2.0とした場合)、淡インクのインク希釈率を濃インクに対して3分の１にすることによって、淡インクの最大打ち込み量が100％でも、全濃度領域に渡って粒状感を小さくできることが分かった。
【０１１９】
また、本実施例では、シアンとマゼンタについてのみ濃度の異なる２種類のインクを用意したが、イエロやブラックについても濃度の異なるインクを組み合わせて用いることも差し支えない。インクは、CMYKの組み合わせに限定されるものではなく、他の組み合わせに適用しても差し支えないし、金や銀等の特色について濃度の異なる２種類のインクを用いることも可能である。
【０１２０】
以上の画像処理により、全濃度領域に渡って粒状感の小さい高精細な画像記録をすることができる。
【０１２１】
（他の実施形態）
本発明において用いる記録ヘッドは、インクを吐出するインクジェット記録ヘッドのみに特定されず、被記録媒体上にドットを形成可能な種々の記録素子を複数備えたものであればよい。
【０１２２】
上記実施形態では、６００ｄｐｉ×６００ｄｐｉの単位領域毎に階調表現を行うと説明したが、階調表現を行う単位領域（単位面積）としては６００ｄｐｉ×６００ｄｐｉの領域に限られるものではない。例えば、１２００ｄｐｉ×１２００ｄｐｉの領域毎に階調表現を行うこととしてもよく、階調表現を行う単位面積の大きさは。上記実施形態の数値に何ら限定されるものではない。
【０１２３】
なお、上記では、便宜上、『６００ｄｐｉ×６００ｄｐｉの解像度に相当する単位領域（単位面積）』という文言を使用したが、その６００ｄｐｉ×６００ｄｐｉの解像度に相当する単位領域（単位面積）とは、(１/６００)inch×(１/６００)inchに相当する面積のことである。同様に、１２００ｄｐｉ×１２００ｄｐｉの解像度に相当する単位領域（単位面積）とは、(１/１２００)inch×(１/１２００)inchに相当する面積のことであり、１２００ｄｐｉ×２４００ｄｐｉの解像度に相当する単位領域（単位面積）とは、(１/１２００)inch×(１/２４００)inchに相当する面積のことである。
【０１２４】
本発明の目的は、前述した実施形態の機能を実現するソフトウェアのプログラムコードを記録した記憶媒体を、システムあるいは装置に供給し、そのシステムあるいは装置のコンピュータ（またはＣＰＵやＭＰＵ）が記憶媒体に格納されたプログラムコードを読出し実行することによっても、達成されることは言うまでもない。
【０１２５】
この場合、記憶媒体から読出されたプログラムコード自体が前述した実施形態の機能を実現することになり、そのプログラムコードを記憶した記憶媒体は本発明を構成することになる。
【０１２６】
プログラムコードを供給するための記憶媒体としては、例えば、フロッピディスク，ハードディスク，光ディスク，光磁気ディスク，ＣＤ−ＲＯＭ，ＣＤ−Ｒ，磁気テープ，不揮発性のメモリカード，ＲＯＭなどを用いることができる。
【０１２７】
また、コンピュータが読出したプログラムコードを実行することにより、前述した実施形態の機能が実現されるだけでなく、そのプログラムコードの指示に基づき、コンピュータ上で稼働しているＯＳ（オペレーティングシステム）などが実際の処理の一部または全部を行い、その処理によって前述した実施形態の機能が実現される場合も含まれることは言うまでもない。
【０１２８】
さらに、記憶媒体から読出されたプログラムコードが、コンピュータに挿入された機能拡張ボードやコンピュータに接続された機能拡張ユニットに備わるメモリに書込まれた後、そのプログラムコードの指示に基づき、その機能拡張ボードや機能拡張ユニットに備わるＣＰＵなどが実際の処理の一部または全部を行い、その処理によって前述した実施形態の機能が実現される場合も含まれることは言うまでもない。
【０１２９】
（その他）
なお、本発明は、特にインクジェット記録方式の中でも、インク吐出を行わせるために利用されるエネルギとして熱エネルギを発生する手段（例えば電気熱変換体やレーザ光等）を備え、前記熱エネルギによりインクの状態変化を生起させる方式の記録ヘッド、記録装置において優れた効果をもたらすものである。かかる方式によれば記録の高密度化，高精細化が達成できるからである。
【０１３０】
その代表的な構成や原理については、例えば、米国特許第４７２３１２９号明細書，同第４７４０７９６号明細書に開示されている基本的な原理を用いて行うものが好ましい。この方式は所謂オンデマンド型，コンティニュアス型のいずれにも適用可能であるが、特に、オンデマンド型の場合には、液体（インク）が保持されているシートや液路に対応して配置されている電気熱変換体に、記録情報に対応していて核沸騰を越える急速な温度上昇を与える少なくとも１つの駆動信号を印加することによって、電気熱変換体に熱エネルギを発生せしめ、記録ヘッドの熱作用面に膜沸騰を生じさせて、結果的にこの駆動信号に一対一で対応した液体（インク）内の気泡を形成できるので有効である。この気泡の成長，収縮により吐出用開口を介して液体（インク）を吐出させて、少なくとも１つの滴を形成する。この駆動信号をパルス形状とすると、即時適切に気泡の成長収縮が行われるので、特に応答性に優れた液体（インク）の吐出が達成でき、より好ましい。このパルス形状の駆動信号としては、米国特許第４４６３３５９号明細書，同第４３４５２６２号明細書に記載されているようなものが適している。なお、上記熱作用面の温度上昇率に関する発明の米国特許第４３１３１２４号明細書に記載されている条件を採用すると、さらに優れた記録を行うことができる。
【０１３１】
記録ヘッドの構成としては、上述の各明細書に開示されているような吐出口，液路，電気熱変換体の組合せ構成（直線状液流路または直角液流路）の他に熱作用部が屈曲する領域に配置されている構成を開示する米国特許第４５５８３３３号明細書，米国特許第４４５９６００号明細書を用いた構成も本発明に含まれるものである。加えて、複数の電気熱変換体に対して、共通するスリットを電気熱変換体の吐出部とする構成を開示する特開昭５９−１２３６７０号公報や熱エネルギの圧力波を吸収する開孔を吐出部に対応させる構成を開示する特開昭５９−１３８４６１号公報に基いた構成としても本発明の効果は有効である。すなわち、記録ヘッドの形態がどのようなものであっても、本発明によれば記録を確実に効率よく行うことができるようになるからである。
【０１３２】
さらに、記録装置が記録できる記録媒体の最大幅に対応した長さを有するフルラインタイプの記録ヘッドに対しても本発明は有効に適用できる。そのような記録ヘッドとしては、複数記録ヘッドの組合せによってその長さを満たす構成や、一体的に形成された１個の記録ヘッドとしての構成のいずれでもよい。
【０１３３】
加えて、上例のようなシリアルタイプのものでも、装置本体に固定された記録ヘッド、あるいは装置本体に装着されることで装置本体との電気的な接続や装置本体からのインクの供給が可能になる交換自在のチップタイプの記録ヘッド、あるいは記録ヘッド自体に一体的にインクタンクが設けられたカートリッジタイプの記録ヘッドを用いた場合にも本発明は有効である。
【０１３４】
また、本発明の記録装置の構成として、記録ヘッドの吐出回復手段、予備的な補助手段等を付加することは本発明の効果を一層安定できるので、好ましいものである。これらを具体的に挙げれば、記録ヘッドに対してのキャッピング手段、クリーニング手段、加圧或は吸引手段、電気熱変換体或はこれとは別の加熱素子或はこれらの組み合わせを用いて加熱を行う予備加熱手段、記録とは別の吐出を行なう予備吐出手段を挙げることができる。
【０１３５】
また、搭載される記録ヘッドの種類ないし個数についても、例えば単色のインクに対応して１個のみが設けられたものの他、記録色や濃度を異にする複数のインクに対応して複数個数設けられるものであってもよい。すなわち、例えば記録装置の記録モードとしては黒色等の主流色のみの記録モードだけではなく、記録ヘッドを一体的に構成するか複数個の組み合わせによるかいずれでもよいが、異なる色の複色カラー、または混色によるフルカラーの各記録モードの少なくとも一つを備えた装置にも本発明は極めて有効である。
【０１３６】
さらに加えて、以上説明した本発明実施例においては、インクを液体として説明しているが、室温やそれ以下で固化するインクであって、室温で軟化もしくは液化するものを用いてもよく、あるいはインクジェット方式ではインク自体を３０℃以上７０℃以下の範囲内で温度調整を行ってインクの粘性を安定吐出範囲にあるように温度制御するものが一般的であるから、使用記録信号付与時にインクが液状をなすものを用いてもよい。加えて、熱エネルギによる昇温を、インクの固形状態から液体状態への状態変化のエネルギとして使用せしめることで積極的に防止するため、またはインクの蒸発を防止するため、放置状態で固化し加熱によって液化するインクを用いてもよい。いずれにしても熱エネルギの記録信号に応じた付与によってインクが液化し、液状インクが吐出されるものや、記録媒体に到達する時点ではすでに固化し始めるもの等のような、熱エネルギの付与によって初めて液化する性質のインクを使用する場合も本発明は適用可能である。このような場合のインクは、特開昭５４−５６８４７号公報あるいは特開昭６０−７１２６０号公報に記載されるような、多孔質シート凹部または貫通孔に液状又は固形物として保持された状態で、電気熱変換体に対して対向するような形態としてもよい。本発明においては、上述した各インクに対して最も有効なものは、上述した膜沸騰方式を実行するものである。
【０１３７】
さらに加えて、本発明インクジェット記録装置の形態としては、コンピュータ等の情報処理機器の画像出力端末として用いられるものの他、リーダ等と組合せた複写装置、さらには送受信機能を有するファクシミリ装置の形態を採るもの等であってもよい。
【０１３８】
【発明の効果】
以上説明したように本発明によれば、淡ドットの最大形成量を多くして、淡インクドットのみで形成される濃度領域が広がると共に、粒状感の目立ちやすい濃ドットが形成される濃度領域が狭まるように、低濃度のドットと高濃度のドットの形成量を最適に設定しているため、全濃度領域に渡ってドットの粒状感を小さくすることができる。
【図面の簡単な説明】
【図１】本発明の一実施例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】本発明の一実施例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）および（ｂ）は、図３の記録ヘッドカートリッジに代えて本発明の一実施例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】本発明の一実施例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】本発明の一実施例のプリンタの動作例を示すフローチャートである。
【図１１】本発明の特徴的な構成部分の第１の実施形態において用いた記録ヘッドを、ノズル側から見た概略構成図である。
【図１２】図１１の記録ヘッドを複数用いる場合の説明図である。
【図１３】図１１のＸＩＩＩ−ＸＩＩＩ線に沿う拡大断面図である。
【図１４】濃インクと淡インクの打ち込み量と反射濃度との関係の説明図である。
【図１５】従来における、各階調レベル（濃度レベル）と、濃インクおよび淡インクの打ち込み量との関係を示す図である。
【図１６】本発明の特徴的な構成部分の第１の実施形態における、各階調レベル（濃度レベル）と、濃インクおよび淡インクの打ち込み量との関係を示す図である。
【図１７】従来のＬＵＴと本発明にて用いるＬＵＴの具体的な比較例の説明図である。
【図１８】図１５と図１６における濃淡インクのコントラスト差の説明図である。
【図１９】画素とドットとの関係の説明図である。
【図２０】ドット面積と単位画素面積との関係の説明図である。
【図２１】解像度と（ドット面積／単位画素面積）との関係の説明図である。
【図２２】（ａ），（ｂ）は、異なる解像度における画素とドットとの関係の説明図である。
【図２３】本発明の特徴的な構成部分の第１の実施形態における画像データ処理部分のブロック構成図である。
【図２４】図２３の画像データ処理部分において用いられる、淡インク用インデックスパターンの説明図である。
【図２５】粒状感の評価関数の値と主観評価との相関関係の説明図である。
【図２６】各階調レベル（濃度レベル）と、濃淡ドットのインデックスパターンとの関係を示す図である。
【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
Ｈ１６００ｄ 連通路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording apparatus, an image processing apparatus, a data generation method, a computer program, and a computer program for determining the formation amount of high density dots and low density dots on a recording medium according to the density level of input image data. It relates to a recording system.
[0002]
[Prior art]
As a conventional ink jet recording apparatus, for example, three color inks of cyan (C), magenta (M), and yellow (Y), or four color inks of cyan, magenta, yellow, and black (K) are used. In some cases, dots are formed by ejecting the ink on a recording medium. In such a recording apparatus, there is a case where the dots are conspicuous in the highlight portion (low density region) of the image and the graininess is increased. As a method of reducing the graininess of such dots, there is a method of using light ink having a low density of about 1/3 to 1/6 of the normal ink density for inks with low brightness such as cyan and magenta. There are the following three recording methods using light ink.
(1) Light ink is applied to the highlight portion, and light ink is applied to the shadow (high density region).
(2) Light ink is applied to the highlight area and dark ink is applied to the shadow area.
(3) Light ink is shot into the highlight area, medium density ink is shot into the medium density area, and dark ink is shot into the shadow area.
[0003]
[Problems to be solved by the invention]
In the case of the above recording method (1), the density of the shadow portion is increased by overprinting the light ink, so that the amount of light ink consumed is higher than usual and the running cost is increased. Furthermore, in order to ensure the density, particularly when recording a secondary color or a tertiary color, the ink overflows due to an increase in the amount of ink applied, and the image quality deteriorates. In addition, the usable recording medium is limited by the relationship with the maximum ink ejection amount.
[0004]
In the case of the recording method of (2) above, by using different inks to be applied to the highlight part and the shadow part, it is possible to achieve both reduction in graininess in the highlight part and increase in density and reduction in ink consumption in the shadow part. I am trying. However, when the density of the light ink is reduced as much as possible, the graininess in the highlight portion is reduced, but the density difference between the light ink and the dark ink is increased, so that the dark ink is formed in the formation area of the light ink dots. In the middle density region where the dots start to enter, the dots become noticeable and the graininess increases. Also, if the density of the light ink is increased in order to reduce the graininess of the dots in the medium density area, the dots of the light ink will be visible, and the dots in the highlight area will be noticeable and the graininess will increase. End up.
[0005]
In the case of the recording method (3), the use of medium-density ink reduces the graininess of dots in the medium-density area, but dark ink, medium-density ink, and light ink for one hue. It is necessary to provide three types of recording heads for ejection and three types of ink, which increases the cost. Furthermore, when performing image processing, since three color tables must be provided for one hue, the image processing becomes complicated.
[0006]
As a recording method that does not use light ink, in order to achieve the same image quality as in the above (1), (2), and (3) using light ink, for example, ink droplets that form dots are reduced to about 0. There is a method of reducing the graininess of the highlight portion by forming small droplets of .5 pl (picoliter) and forming dots smaller than usual. However, in this recording method, the recording resolution is increased and the recording speed is decreased, it is difficult to stably land the ink droplets on the target landing position, and it is difficult to manufacture the recording head. There is a risk of incurring a cost increase due to the deterioration of the yield.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a recording apparatus, an image processing apparatus, and data generation capable of reducing the granularity of dots over the entire density area by optimally setting the formation amounts of low density dots and high density dots. It is to provide a method, a computer program, and a recording system.
[0008]
[Means for Solving the Problems]
The recording apparatus of the present invention records an image on a recording medium using a first ink and a second ink having a color similar to the first ink and having a higher density than the first ink. The maximum amount of the first ink applied to the unit area of the recording medium according to the gradation level of the image is the maximum amount of the second ink applied to the unit area. 1.75 times or more, The application amount of the first ink decreases as the gradation level increases beyond the gradation level when the application amount of the first ink reaches the maximum amount, and the gradation level is maximum. When it is lower than the gradation level, the zero is maintained until the maximum gradation level from zero. Using the second ink start The gradation level is 1.75 times the maximum amount of the first ink applied by the first ink. More than the gradation level when Gradation level Because ,and, A gradation level including a range equal to or less than a gradation level when the application amount of the first ink reaches a maximum amount; The first ink By Expressed within the unit area Possible gradation levels The number is the second ink By Expressed within the unit area Possible gradation levels It is characterized by more than the number.
[0009]
The image processing apparatus of the present invention records an image on a recording medium using the first ink and the second ink having a color similar to the first ink and having a higher density than the first ink. An image processing apparatus for generating image data for applying the first ink to the unit area based on input image data indicating a gradation level of an image to be recorded in the unit area of the recording medium Generating means for generating image data corresponding to the amount and the amount of the second ink applied to the unit area, wherein the generating means determines the maximum amount of the first ink to be applied to the unit area. 1.75 times or more of the maximum amount of the second ink applied to the unit area, The application amount of the first ink is decreased as the gradation level increases beyond the gradation level when the application amount of the first ink reaches the maximum amount, and the gradation level is maximized. Maintaining zero until the maximum gradation level from zero when lower than the gradation level of The second ink First use The first ink application amount is 1.75 times the maximum amount of the second ink. More than the gradation level when Gradation level And a gradation level including a range equal to or lower than the gradation level when the application amount of the first ink reaches the maximum amount. And the first ink By Expressed within the unit area Possible gradation levels The number of the second ink By Expressed within the unit area Possible gradation levels The image data is generated so as to be larger than the number.
[0010]
The data generation method of the present invention records an image on a recording medium using a first ink and a second ink having a color similar to that of the first ink and having a higher density than the first ink. A data generation method for generating image data for providing the first ink to the unit area based on input image data indicating a gradation level of an image to be recorded in the unit area of the recording medium A generating step for generating image data corresponding to the amount and the amount of the second ink applied to the unit region, wherein the generating step determines the maximum amount of the first ink to be applied to the unit region, 1.75 times or more of the maximum amount of the second ink applied to the unit area, The application amount of the first ink is decreased as the gradation level increases beyond the gradation level when the application amount of the first ink reaches the maximum amount, and the gradation level is maximized. Maintaining zero until the maximum gradation level from zero when lower than the gradation level of The second ink First use The first ink application amount is 1.75 times the maximum amount of the second ink. More than the gradation level when Gradation level And a gradation level including a range equal to or lower than the gradation level when the application amount of the first ink reaches the maximum amount. And the first ink By Expressed within the unit area Possible gradation levels The number of the second ink By Expressed within the unit area Possible gradation levels The image data is generated so as to be larger than the number.
[0011]
A computer program according to the present invention causes the above-described data generation method to be executed by a computer.
The recording system of the present invention can record an image on a recording medium using a first ink and a second ink having a color similar to that of the first ink and having a higher density than the first ink. And a data supply device for supplying image data indicating a gradation level of an image to be recorded in the recording device, wherein the recording medium is based on the image data. The maximum amount of the first ink applied to the unit region is 1.75 times or more the maximum amount of the second ink applied to the unit region based on the image data. The application amount of the first ink decreases as the gradation level increases beyond the gradation level when the application amount of the first ink reaches the maximum amount, and the gradation level is maximum. When it is lower than the gradation level, the zero is maintained until the maximum gradation level from zero. Using the second ink start The gradation level is 1.75 times the maximum amount of the first ink applied by the first ink. More than the gradation level when Gradation level Because ,and, A gradation level including a range equal to or less than a gradation level when the application amount of the first ink reaches a maximum amount; The first ink based on the image data By Expressed within the unit area Possible gradation levels The number is calculated based on the image data. By Expressed within the unit area Possible gradation levels It is characterized by more than the number.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Prior to the description of the embodiments of the characteristic components of the present invention, first, the embodiments of the basic components of the present invention will be described with reference to FIGS.
[0013]
In the embodiments described below, a printer is taken as an example of a recording apparatus using an inkjet recording method.
[0014]
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.
[0015]
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.
[0016]
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).
[0017]
[Device main unit]
1 and 2 show a schematic configuration of a printer using the ink jet recording method. In FIG. 1, the printer main body M1000 in this embodiment includes an exterior 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. 1) housed in the exterior member. 2).
[0018]
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. A hollow body structure having a storage space for storing the mechanism is formed. An opening is formed in each of the upper surface portion and the front surface portion of the apparatus main body M1000.
[0019]
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. In addition, the discharge tray M1004 contains two auxiliary trays M1004a and M1004b. By pulling out each tray as needed, the sheet support area can be expanded or reduced in three stages. It has become.
[0020]
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.
[0021]
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. 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.
[0022]
[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.
[0023]
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).
[0024]
(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.
[0025]
Recording head cartridge
First, a recording head cartridge used in the recording unit will be described with reference to FIGS.
[0026]
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.
[0027]
The recording head cartridge H1000 shown here is provided with ink tanks H1900 that are independent of each color of black, light cyan, light magenta, cyan, magenta, and yellow, for example, in order to enable high-quality color recording with photographic tone. As shown in FIG. 4, each is detachable from the recording head H1001.
[0028]
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.
[0029]
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.
[0030]
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.
[0031]
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.
[0032]
(carriage)
Next, the carriage M4001 on which the recording head cartridge H1000 is mounted will be described with reference to FIG.
[0033]
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.
[0034]
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.
[0035]
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).
[0036]
[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.
[0037]
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.
[0038]
FIGS. 6A and 6B are diagrams illustrating the scanner M6000 upside down in order to explain the schematic configuration of the scanner M6000.
[0039]
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 at 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.
[0040]
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.
[0041]
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.
[0042]
[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.
[0043]
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.
[0044]
Further, the main PCBE0014 is a printed circuit board unit that controls driving 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, a parallel sensor. The board has I / O ports for an 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. .
[0045]
FIG. 8 is a block diagram showing an internal configuration of the main PCB E0014. In the figure, E1001 is a CPU, and this CPU E1001 has a clock generator (CG) 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 the power key, and an input signal E1016 from the 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.
[0046]
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.
[0047]
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.
[0048]
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.
[0049]
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.
[0050]
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.
[0051]
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) E1032 from PG sensor E0010 Is detected and transmitted to the CPU E1001 via the control bus E1014. Based on the input data, the CPU E1001 controls the driving of the LED drive signal E1038 to blink the LEDE0020.
[0052]
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.
[0053]
FIG. 9 is a block diagram showing an example of the internal configuration of ASIC E1006.
[0054]
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.
[0055]
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).
[0056]
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.
[0057]
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.
[0058]
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.
[0059]
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 E2004 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.
[0060]
E2006 is an IEEE 1284 I / F. Under the control of the CPU E1001 via the CPU I / F E2001, a parallel communication interface with an external host device (not shown) is performed through the parallel I / F E0016, and parallel is also used during recording. 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.
[0061]
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 is read by 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 read buffer address managed by the receive 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.
[0062]
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.
[0063]
E2015 is a recording data expansion DMA controller, which is recorded and written on the print buffer by using the data expansion timing signal E2050 from the head controller E2018 as a trigger 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.
[0064]
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.
[0065]
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. Under the control of the CPU E1001 via the CPU I / F E2001, the acquisition buffer read data (RDAV) E2054 stored in the scanner acquisition buffer E2024 is read and subjected to processing such as averaging. The processed 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.
[0066]
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.
[0067]
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 CPUE1001. 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.
[0068]
The LF / PG motor control DMA controller E2021 reads out 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.
[0069]
[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.
[0070]
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.
[0071]
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.
[0072]
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.
[0073]
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.
[0074]
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.
[0075]
In step S8, the LF motor E0002 is driven, the paper discharge roller M2003 is driven, and the paper feeding is repeated until it is determined that the paper is 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.
[0076]
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.
[0077]
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.
[0078]
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.
[0079]
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.
[0080]
(First embodiment)
Next, a first embodiment of the characteristic components of the present invention will be described.
[0081]
"Head configuration and recording method"
In the present embodiment, a recording head H configured as shown in FIGS. 11 to 13 is used as the recording head H1001 mounted on the carriage M4001. In the recording head H of this example, a plurality of ejection ports P capable of ejecting ink are formed in two rows (hereinafter also referred to as “nozzle rows”) L1 and L2. The nozzle rows L1 and L2 extend in the sub-scanning direction of the arrow B where the recording medium is conveyed. In each of the nozzle rows L1 and L2, the discharge ports P constituting the nozzles are formed 128 (128 nozzles) at intervals corresponding to 600 dpi as the pitch Py. Further, the discharge ports P of the nozzle row L1 and the discharge ports P of the nozzle row L2 are shifted by a half pitch (Py / 2) corresponding to 1200 dpi in the sub-scanning direction of the arrow Y. An arrow X is the main scanning direction in which the recording head H reciprocates. Then, by ejecting the same color ink from a total of 256 ejection openings P in these two rows, an image can be recorded with a dot density in the sub-scanning direction of 1200 dpi. Accordingly, the recording resolution in the sub-scanning direction is twice that when only one of the nozzle rows L1 and L2 is provided. In the case of this example, for the reason described later, the diameter of dots formed by the ink ejected from the nozzles is set to 45 μm.
The interval corresponding to 1200 dpi is 21.7 μm.
[0082]
In the case of this example, a multi-pass printing method is employed to record pixels on the same raster using a plurality of nozzles. For example, when the 8-pass unidirectional printing method or the 8-pass bidirectional printing method is adopted, the same raster is printed using eight different nozzles by eight passes (scanning) of the print head H. The influence of image disturbance due to variations in the ink ejection direction at the nozzles can be minimized. Further, in the case of the unidirectional recording method, the recording operation is performed only when the recording head H is scanned in one direction, and in the case of the bidirectional recording method, the recording operation is performed when the recording head H is scanned in both directions.
[0083]
Further, in the case of this example, as will be described later, the recording resolution in the main scanning direction is 2400 dpi, which is twice the basic recording density of 1200 dpi, and the recording resolution in the main scanning direction and the sub-scanning direction is (2400 dpi × 1200 dpi). A halftone (halftone level) is recorded using an error diffusion method (ED).
[0084]
In the case of this example, the resolution of the image data input from the host device to the recording device is (600 ppi × 600 ppi). As shown in FIG. 22B, the recording apparatus has a gradation for each 4 × 2 recording area in which the main scanning direction is 4 pixels and the sub-scanning direction is 2 pixels in order to correspond to the (2400 dpi × 1200 dpi) recording mode. Make an expression. In other words, gradation representation is performed for each unit region (unit area) corresponding to a resolution of 600 ppi × 600 ppi. It should be noted that the number of gradations expressed in each unit area is 9 gradations of gradation levels 0-8. In the case of this example, six recording heads H are provided as shown in FIG. 12, respectively cyan (C), magenta (M), yellow (Y), black (K) ink, light cyan (Lc), Light magenta (Lm) ink is ejected. Cyan (C), magenta (M), yellow (Y), and black (K) inks are dark inks having a relatively high dye density, and light cyan (Lc) and light magenta (Lm) inks are dark inks. It is a light ink having a relatively low dye concentration that is 1/6 the density of the ink. In this way, a color image can be recorded by ejecting different inks from each recording head H in which the two nozzle rows L1 and L2 are formed. If the recording mode is (1200 dpi × 1200 dpi), as shown in FIG. 22A, a 2 × 2 recording area (600 ppi × 600 ppi resolution) having two pixels in the main scanning direction and two pixels in the sub-scanning direction is used. The gradation expression is performed for each unit area corresponding to
[0085]
In FIG. 13, h is a heater (electrothermal converter), which generates thermal energy used as the ejection energy of the ink droplet I ′ in accordance with the drive signal. Film boiling occurs in the ink I in the nozzle by the thermal energy of the heater h, and the ink droplet I ′ is ejected from the ejection port P by the foaming energy at that time.
[0086]
“Relationship between implantation amount and concentration”
Next, the relationship between the recording density and the amount of ink applied to the recording medium to form dots will be described with reference to FIG.
[0087]
Here, when the unit area corresponding to the resolution of 1200 dpi × 1200 dpi as shown in FIG. 22 is defined as one pixel, the shot amount is a dot that is large enough to fill the one pixel. This is an index indicating how much (number) of pixels is formed, and the ink ejection amount when one dot is formed per pixel is 100%. Therefore, the amount of ink when two dots are formed per pixel is 200%, and the amount of ink applied when three dots are formed per pixel is 300%. As is apparent from FIG. 22A, since one dot is formed for each unit area of 1200 dpi × 1200 dpi, the driving amount is 100%, and in FIG. 22B, 1200 dpi × 1200 dpi. Since 2 dots are formed for each unit area, the driving amount is 200%.
[0088]
Further, the method of defining the driving amount is not limited to this, and it may be defined as follows. That is, as shown in FIG. 22, when the number of dots necessary to fill a unit area corresponding to a resolution of 600 dpi × 600 dpi is formed for the unit area, the shot amount is defined as 100%. Also good. Specifically, as shown in FIG. 22A, when four dots are formed in a unit area corresponding to a resolution of 600 dpi × 600 dpi, the shot amount is set to 100%, as shown in FIG. In addition, when 8 dots are formed in a unit area corresponding to a resolution of 600 dpi × 600 dpi, the shot amount is set to 200%. Therefore, when 5 dots are formed in a unit area corresponding to a resolution of 600 dpi × 600 dpi, the shot amount is 125%, and when 7 dots are formed in the unit area, the shot amount is 175%. It becomes.
[0089]
As described above, in this specification, the “driving amount” is a predetermined unit area (unit area) determined in advance, such as a unit area corresponding to a resolution of 1200 dpi × 1200 dpi, a unit area corresponding to a resolution of 600 dpi × 600 dpi, or the like. In the case where the number of dots (N) necessary to fill up the unit area is formed with respect to the unit area, it is defined that the shot amount is 100%. Accordingly, when 2N dots are formed in a predetermined unit area (unit area) determined in advance, the amount of shot is 200%, and 1.75N dots in a predetermined unit area (unit area) determined in advance. Is formed, the driving amount is 175%.
[0090]
As shown in FIG. 14, in the case of dark ink, when the amount of ink shot is 0% to 100%, the density is increased almost linearly. However, when the driving amount exceeds 125%, the concentration hardly increases. Further, when the shot amount is 200% or more, the density is lowered rather than the density is increased, and the image quality is deteriorated due to overflow of ink. Accordingly, it can be seen that there is not much merit in terms of image quality even if forcing the ink to be applied more than 125% for the total amount of ink applied during recording of the secondary color and the tertiary color or more.
[0091]
On the other hand, in the case of light ink, the density is increased almost linearly when the ink hit amount is from 0% to 200%. Further, when the driving amount is increased to 300%, the density itself hardly increases, and the ink may overflow from the recording medium and image quality may be deteriorated. Therefore, with respect to the light ink, as long as it is used in the range of the ink hitting amount from 0% to less than 300% exceeding 200%, the density is increased and the excellent gradation is obtained as compared with the normal use of 100%. It will be.
[0092]
In the present embodiment, the dark ink and light ink placement amounts for a predetermined unit area determined in advance are determined using a look-up table (LUT).
[0093]
FIG. 15 is an explanatory diagram of a conventional LUT. This LUT gradually increases the amount of light ink applied in accordance with the input gradation level (the density level of the input image data), and after the amount of ink is increased from 100% to 130%, the amount of ink applied Reduce gradually. Moreover, the dark ink starts to be printed at the input gradation level when the maximum amount of light ink is printed, and the dark ink is gradually increased according to the input gradation level. When the maximum value is reached, the amount of dark ink is maximized.
[0094]
FIG. 16 is an explanatory diagram of an LUT used in the present embodiment. In this LUT, the maximum amount of light ink applied is 200% (first maximum amount). Therefore, as compared with the case where the conventional LUT of FIG. 15 is used, the input gradation level when the maximum amount of light ink is printed increases and the dot density at that time also increases. For this reason, the input gradation level when starting to dark ink is increased. As a result, at the time when the dark ink is started to be ejected, when the maximum amount of light ink is 200%, as shown in the graph on the right side of FIG. The difference (contrast) from the density of C2 is relatively small. Accordingly, it is possible to reduce the graininess by making the dots inconspicuous in the middle density region where the dark ink starts to be ejected. On the other hand, when the conventional LUT of FIG. 15 is used, when the amount of light ink is set to 100% at the maximum when the dark ink starts to be applied, as shown in the graph on the left side of FIG. The difference (contrast) between the density of the light ink driven by 100% and the density of the dark ink is C1 (> C2). For this reason, in the middle density region where the dark ink starts to be printed, the dots are noticeable and the graininess is increased.
[0095]
Further, when the LUT shown in FIG. 16 is used, the input gradation level at the start of dark ink injection increases, so the change gradient of the dark ink injection amount with respect to the input gradation level is the conventional LUT shown in FIG. It becomes larger than the case where is used. Therefore, as shown in FIG. 16, the medium density area after the start of dark ink, that is, the density area (gradation level width) A that tends to give a grainy feeling is narrowed, and the density area (gradation) where dark ink is applied. The level width B) can also be reduced. As a result, it is possible to record a high-quality image with a small granularity in all density regions as compared with the case of using the conventional LUT of FIG. In FIG. 16, the maximum dark ink ejection amount is set to 100% (second maximum amount).
[0096]
As described above, in this embodiment, when determining the formation amount of light dots (low density dots) and dark dots (high density dots) for a predetermined unit area, an LUT as shown in FIG. 16 is used. In the LUT, for light ink that linearly increases in density up to at least 200%, the dark ink whose density increases linearly up to 100% is set to 200% (first maximum amount). In this case, the maximum driving amount is set to 100% (second maximum amount). As a result, the width of the gradation level (density level) formed with only light ink that is less noticeable in graininess can be increased, while the gradation level (density level) in which dark ink that is relatively noticeable in graininess is formed. Therefore, the graininess of the entire image can be reduced.
[0097]
In the present invention, as the predetermined gradation level at which dark ink is started, the gradation is lower than the gradation level corresponding to the case where the maximum amount of light ink is applied, as shown in FIG. The level is preferred. That is, it is preferable to start the dark ink before the amount of light ink has reached the first maximum amount (200%). However, when the gradation level at which dark ink is started is too low, that is, when dark ink is started when the amount of light ink is small, the graininess cannot be reduced. Therefore, it is preferable to set the gradation level at which the amount of light ink has reached at least 175% as the predetermined gradation level at which dark ink has been started. When the dark ink is started from the gradation level where the amount of light ink is 175% or more, the width of the density region formed only with the light ink is widened and the graininess is more conspicuous than in the past. Since the density region where the dark dots are formed is narrowed, the graininess is reduced as a whole. In this way, by setting the predetermined gradation level at which dark ink is started to be set to a gradation level lower than the gradation level corresponding to the case where the maximum amount of light ink is applied, recording from light dots can be performed. The color mixture at the joint to the recording due to the dark dots becomes extremely smooth, and the quality of the recorded image becomes extremely high.
[0098]
FIG. 17 is a diagram comparing a conventional LUT and an LUT used in the present invention. In particular, the density area A (the middle density area after the start of dark ink, that is, the density area where graininess is conspicuous), B (the density area where the dark ink is printed), and the density area A ′ in the conventional LUT corresponding thereto. , B ′. In this example, the gradation level widths corresponding to the regions A, A ′, B, and B ′ are A = 50, A ′ = 100, B = 95, and B ′ = 175, and A <A ′, B <B '. As is apparent from the above, in the present invention, the density area (tone level width) B into which dark ink is applied is smaller than in the prior art, and the density area (tone level width) A where graininess is conspicuous. By narrowing, the graininess of dots is reduced.
[0099]
As shown in FIG. 16, the LUT used in the present embodiment is a table that starts dark ink before the light ink has reached the first maximum amount (200%). Alternatively, as shown in FIG. 17, a table may be used in which the dark ink is started when the amount of the light ink has reached the first maximum amount (200%). As described above, in this embodiment, the predetermined gradation level (density level) at which dark ink is started is set to a density level equal to or lower than the density level corresponding to the first maximum amount that is the maximum amount of light ink. Alternatively, a density level exceeding the density level corresponding to the first maximum amount may be set. In other words, the predetermined gradation level (density level) at which dark ink ejection starts may be set to a density level higher than the predetermined density level when a predetermined amount of low density dots are formed.
[0100]
"Relationship between pixels and dots"
When the recording resolution is 1200 dpi × 1200 dpi, the area A per pixel is 448 μm as shown in FIG. ² It becomes. Therefore, the minimum dot diameter required to fill the one pixel is a diagonal distance of 30 μm per pixel, and the dot area S0 is 706.5 μm. ² It becomes. This value is about 1.5 times (158%) or more of the area per pixel. However, in practice, it is necessary to add about 10 μm as a mechanical error of the printer (ink landing accuracy of the recording head, paper feed error, etc.). Therefore, the optimum dot diameter is 40 μm. The area of the dots is 1257 μm ² This is about 2.8 times the area A per pixel. As described above, in a high resolution printer having a recording resolution of 1200 dpi × 1200 dpi or more, it is necessary to determine the dot diameter so that the dot area is 2.0 times or more per unit pixel area in order to ensure the necessary resolution. For dot diameters that do not meet these conditions, the area factor is not sufficient, so banding (density unevenness in the main scanning direction) may occur due to irregular dot landing accuracy, paper feed error, carriage movement error, etc. Is likely to occur.
[0101]
20 and 21 are diagrams illustrating the relationship between the unit pixel area corresponding to the resolution and the dot area corresponding to the dot diameter. In this embodiment, the dot diameter is 45 μm so that one pixel at a resolution of 1200 dpi × 1200 dpi shown in FIG. 22A can be sufficiently filled with one dot. From the area factor, the optimum resolution for a dot diameter of 45 μm is 1200 dpi × 1200 dpi. In that case, the ink ejection amount per pixel is 100%.
[0102]
However, in the case of the present embodiment, as described above, in order to reduce the graininess particularly in the middle density region, it is necessary to increase the maximum amount of light ink to 200%. Therefore, in this embodiment, as shown in FIG. 22B, by setting the resolution in the main scanning direction to 2400 dpi, which is twice 1200 dpi, the unit area in the main scanning direction (1200 dpi × 1200 dpi resolution) is consequently obtained. The dot shot amount per area of one pixel was doubled. Accordingly, when a dot is shot on each of 8 pixels of 4 × 2 at a recording resolution of 2400 dpi × 1200 dpi, the ink shot amount per pixel at a resolution of 1200 dpi × 1200 dpi is 200%. In this case, the dot area is 1590 μm with a dot diameter of 45 μm. ² Is an area per pixel at a resolution of 2400 dpi × 1200 dpi 224 μm ² Is about 7 times.
[0103]
"Processing method of input image data"
FIG. 23 is a functional block diagram for explaining the function of the image processing unit 230 that processes input image data. The image processing unit 230 includes a color processing unit 210 and a quantization unit 220. Input image data of 8 bits (256 gradations) for each of R, G, and B colors is input into C, M, Y, K, Lc, Lm is output as 4-bit data for each color. The color processing unit 210 includes a color space conversion processing unit 211, a color conversion processing unit 212, and an output Γ processing unit 213.
[0104]
In such an image processing unit 230, R, G, B color bit data input from an external host device is first converted into R ′, G ′, B ′ color by the three-dimensional LUT of the color space conversion processing unit 211. Converted to 8-bit data. This processing is also referred to as pre-stage color processing, and performs conversion processing for correcting the difference between the color space of the input image (color space) and the reproduction color space of the output device.
[0105]
Next, the 8-bit data of each color R ′, G ′, B ′ subjected to the preceding stage color processing is converted into 8-bit data of each color C, M, Y, K by the three-dimensional LUT of the color conversion processing unit 212. . This process is also referred to as a post-stage color process, and is a color conversion process for converting an input RGB color to an output CMYK color. Furthermore, C (cyan) and M (magenta) data are separated into dark ink data and light ink data, respectively. At this time, the data for C (dark cyan) and Lc (light cyan) are separated so that the dark ink injecting amounts have the relationship shown in FIG. 16 or FIG. Similarly, the data for M (dark magenta) and Lm (light magenta) are separated so that their dark and light ink ejection amounts have the relationship shown in FIG. 16 or FIG. Note that the LUTs in FIGS. 16 and 17 are provided for each predetermined unit area (unit area corresponding to a resolution of 600 ppi × 600 ppi) composed of 8 pixels (4 × 2) in FIG. The amount of dark and light ink is determined. Accordingly, the horizontal axis of the LUT in FIGS. 16 and 17 is a value obtained by averaging the input gradation levels for every 8 pixels (4 × 2) included in the predetermined unit area.
[0106]
The 8-bit data of each color of C, M, Y, K, Lc, and Lm subjected to the subsequent color processing is subjected to output Γ correction by the one-dimensional LUT of the output Γ processing unit 213, and then is performed by the quantization processing unit 221. Binarization processing is performed. In the case of the present embodiment, the relationship between the amount of light ink applied to the unit area and the light ink index pattern showing the light dot arrangement is as shown in FIG. That is, as the amount of light ink applied is increased from 0 to 200%, the number of dots formed in the unit area is also increased from 0 to 8. In FIG. 24, the index pattern indicated by 9 levels from 0 to 8 has 9 gradations when 0 to 8 dots are formed for 8 pixels (4 × 2) in FIG. Equivalent to.
[0107]
FIG. 26 is a diagram showing the relationship between each gradation level (density level) and the light and dark dot index pattern. Each gradation level shown in FIG. 26 corresponds to each gradation level in the LUT of the present invention shown in FIG. 17, and each gradation level is converted into the index pattern of FIG. 26 based on this LUT. . As is clear from FIG. 26, for light ink, in the range of (1) gradation level (density level) 0 to 160, the number of light dots formed in a predetermined unit area as the gradation level increases. Gradually increase from 0 to 8, and (2) a gradation level range (160 to 255) higher than the gradation level 160 where the formation amount per unit area is the first maximum amount (eight). In, as the gradation level increases, the number of light dots formed in a predetermined unit area is gradually reduced from 8 to 0. As for dark ink, the number of dark inks is increased from the gradation level 160 onward after the gradation level 160 corresponding to the first maximum amount where the amount of light ink is maximized. In 255), the number of dark dots formed in a predetermined unit area is gradually increased from 0 to 4. As described above, when each gradation level is converted into an index pattern based on the LUT of the present invention, the maximum number of light dots formed for a predetermined unit area (eight) is the same as the predetermined unit area. This is twice the maximum number (4) of dark dots to be formed. As apparent from the consideration of FIG. 17, in FIG. 26, when 4 dots are formed per unit area, the shot amount is 100%, and 8 dots are formed per unit area. In this case, the driving amount is 200%.
[0108]
Although the case where the amount of light ink applied is 200% has been described above, the amount of light ink applied is not limited to 200%. Even when 200% or more of light ink is applied, there is an increase in density. Accordingly, when the gradation level corresponding to the maximum amount of light ink is the same as the gradation level at which dark ink is started, and the maximum amount of light ink is set to 200% or more, FIG. Since the density region (tone level width) B into which the dark ink shown in FIG. 6 is applied becomes narrower, the graininess can be further reduced. Thus, when the shot amount is 200% or more, the first maximum amount that is the maximum formation amount of light dots per unit area is larger than the second maximum amount (100%) that is the maximum formation amount of dark dots per unit area. More than twice.
[0109]
Further, the amount of light ink applied may be 175% instead of 200%. That is, when the gradation level corresponding to the maximum amount of light ink is the same as the gradation level at which dark ink is started, and the maximum amount of light ink is set to 175%, 200% Compared to the case, the density region (tone level width) B into which the dark ink shown in FIG. 17 is applied becomes wide, but is narrower than the density region (tone level width) B in the conventional LUT. Since the graininess can be sufficiently reduced, it is sufficient that the maximum amount of light ink is at least 175%. Thus, when the shot amount is 175% or more, the first maximum amount that is the maximum formation amount of light dots per unit area is larger than the second maximum amount (100%) that is the maximum formation amount of dark dots per unit area. 1.75 times or more.
[0110]
As described above, according to the present embodiment, as shown in the LUTs of FIGS. 16 and 17, for the light ink, as the density level increases, the formation amount of the light dots is reduced to the first maximum amount. The amount of light dot formation is determined so as to gradually increase to (for example, 200%) and then gradually decrease. (2) For dark ink, the density level is high in a range of density levels higher than a predetermined density level (density level at which dark ink starts to be formed) equal to or less than the density level corresponding to the first maximum amount. Accordingly, the dark dot formation amount is determined so as to gradually increase the dark dot formation amount to the second maximum amount (100%) smaller than the first maximum amount (200%). Thus, by determining the formation amount of light and dark dots corresponding to each density level, the maximum formation amount of light dots is increased as compared with the conventional case, and the density region formed by only light ink dots is widened. As a result, the density region where dark dots that are prominent in graininess are formed is narrowed, and graininess is reduced as a whole.
[0111]
(Second Embodiment)
As described above, when the LUT shown in FIG. 16 is used, the input gradation level when the dark ink starts to be printed increases. As a result, the medium density region, that is, the graininess after the dark ink starts to be printed. Can be narrowed, and the density area B into which dark ink is applied can also be narrowed. On the other hand, the upper limit of the maximum ink ejection amount is determined by the type of recording medium. For this reason, it is necessary to determine the input gradation level at the start of dark ink injection so as to reduce the granularity of dots within the range of the maximum injection amount. However, when the maximum hit amount is increased to the upper limit value, there is a possibility that image deterioration due to ink bleeding may occur when a secondary color or a tertiary color is expressed by a color mixture with other color inks.
[0112]
In the present embodiment, in order to determine the input gradation level at the time when the dark ink is started to be applied, an evaluation formula for quantifying the graininess is used. As evaluation formulas that quantify graininess, evaluation formulas using the granularity evaluation function, Dooly and Shaw evaluation formulas using Wiener spectrum and VTF, and the like are known. In the case of this example, an evaluation formula using the Granularity evaluation function was used. The evaluation formula evaluates the graininess by using a Granularity evaluation function that incorporates human visual characteristics into the RMS granularity used as a measure for measuring the graininess in silver halide photographic film. . Specifically, P ′ obtained by applying a visual filter to the image P, that is, a spatial frequency characteristic P ′ obtained by FFT (Fast Fourier Transform), is obtained, and the standard deviation of the pixel values in the P ′ is defined as the granularity G. The observation distance in VTF (V) is assumed to be 28.6 cm. VTF (V) is a measure of how many levels of light and dark can be discriminated by the human eye for each spatial frequency (Dooly approximation). The evaluation formula is shown below. The following formula is published in the document "High-quality inkjet printer and its evaluation" (Canon, Inc. Tsuyoshi Hamada, Keigo Gotta).
[0113]
[Equation 3]

[0114]
i: Pixel position in the X direction
j: Pixel position in the Y direction
N: Size of the image P in the X and Y directions
[0115]
Next, the correlation between the Granularity evaluation value (G) and the subject test was obtained. The printer used for the measurement was Canon BJF-850 (6-color dark and light inkjet printer, resolution 1200 dpi × 1200 dpi, dot diameter 40 μm), and the drum scanner was Scantek 4500 from Howtek. In this measurement, a uniform density patch (gray scale 50%) was output using a K (black) ink by a printer, and the output image was read by a drum scanner having a resolution of 1000 dpi. The input image from the drum scanner was cut into 1024 x 1024 [pixels] and evaluated using the Granularity evaluation function. FIG. 25 shows the evaluation results.
[0116]
From the Granularity evaluation value (G) in FIG. 25 and the results of the subject test, it was found that the evaluation value of the concentration region A in FIG. 16 needs to be suppressed to 0.6 or less. More preferably, the graininess can be reduced over the entire density range by limiting the value to 0.4 or less.
[0117]
Further, when determining the ink density, the Granularity evaluation function can be used as it is. For example, when determining the density of the light ink, the density of the light ink is diluted to 1/3, 1/4, 1/5, and 1/6, and whether or not dots can be seen in the highlight area is determined. Subjective evaluation and Granularity value are used in combination as materials for determining whether or not dark ink dots are visible. Accordingly, it is possible to determine the ink density in consideration of the granularity of the highlight area and the medium density area.
[0118]
Using the Granularity evaluation function, the ink density and the dot diameter were examined so that the granularity becomes a small value (Granularity value 0.4 or less) over the entire density region. As a result, in the six-color dark and light ink jet printer as in this example, the dot diameter is 30 μm (discharge amount 2 pl; when the bleeding rate is about 2.0), and the ink dilution rate of light ink is 1/3 of the dark ink. Thus, it was found that the graininess can be reduced over the entire density region even when the maximum amount of light ink is 100%.
[0119]
In this embodiment, two types of ink having different densities are prepared only for cyan and magenta, but it is also possible to use a combination of inks having different densities for yellow and black. The ink is not limited to the combination of CMYK, and may be applied to other combinations, and two types of inks having different densities with respect to special colors such as gold and silver can be used.
[0120]
Through the image processing described above, high-definition image recording with a small graininess can be performed over the entire density region.
[0121]
(Other embodiments)
The recording head used in the present invention is not limited to only an ink jet recording head that ejects ink, and may be any one that includes a plurality of various recording elements capable of forming dots on a recording medium.
[0122]
In the above embodiment, it has been described that gradation expression is performed for each unit area of 600 dpi × 600 dpi. However, the unit area (unit area) for gradation expression is not limited to the region of 600 dpi × 600 dpi. For example, gradation expression may be performed for each area of 1200 dpi × 1200 dpi, and the size of a unit area for gradation expression is. It is not limited to the numerical values of the above embodiment.
[0123]
In the above description, the term “unit region (unit area) corresponding to a resolution of 600 dpi × 600 dpi” is used for convenience. However, the unit region (unit area) corresponding to a resolution of 600 dpi × 600 dpi is (1) / 600) inch × (1/600) inch. Similarly, a unit region (unit area) corresponding to a resolution of 1200 dpi × 1200 dpi is an area corresponding to (1/1200) inch × (1/1200) inch, and corresponds to a resolution of 1200 dpi × 2400 dpi. The unit region (unit area) is an area corresponding to (1/1200) inch × (1/2400) inch.
[0124]
An object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and store the computer (or CPU or MPU) of the system or apparatus in the storage medium. Needless to say, this can also be achieved by reading and executing the programmed program code.
[0125]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.
[0126]
As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.
[0127]
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.
[0128]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.
[0129]
(Other)
The present invention includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for ejecting ink, particularly in the ink jet recording system, and the ink is generated by the thermal energy. In the recording head and the recording apparatus of the type that causes the state change, excellent effects are brought about. This is because such a system can achieve high recording density and high definition.
[0130]
As for the typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid and, as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve discharge of a liquid (ink) having particularly excellent responsiveness. As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0131]
As the configuration of the recording head, in addition to the combination configuration (straight liquid channel or right angle liquid channel) of the discharge port, the liquid channel, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting part The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose the configuration in which the lens is disposed in the bending region, are also included in the present invention. In addition, for a plurality of electrothermal transducers, Japanese Patent Application Laid-Open No. Sho 59-123670 that discloses a configuration in which a common slit is used as a discharge portion of the electrothermal transducer or an aperture that absorbs pressure waves of thermal energy is provided. The effect of the present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461 which discloses a configuration corresponding to the discharge unit. That is, whatever the form of the recording head is, according to the present invention, recording can be performed reliably and efficiently.
[0132]
Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by the recording apparatus. As such a recording head, either a configuration satisfying the length by a combination of a plurality of recording heads or a configuration as a single recording head formed integrally may be used.
[0133]
In addition, even the serial type as shown in the above example can be connected to the main body of the recording head or attached to the main body of the device so that electrical connection with the main body of the device and ink supply from the main body are possible. The present invention is also effective when a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself is used.
[0134]
In addition, it is preferable to add a recording head ejection recovery means, a preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention, since the effects of the present invention can be further stabilized. Specifically, heating is performed using a capping unit, a cleaning unit, a pressurizing or suction unit, an electrothermal transducer, a heating element different from this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.
[0135]
Also, regarding the type or number of recording heads to be mounted, for example, a plurality of recording heads are provided corresponding to a plurality of inks having different recording colors and densities, in addition to one provided corresponding to a single color ink. May be used. That is, for example, as a recording mode of the recording apparatus, not only a recording mode of only a mainstream color such as black, but also a recording head may be configured integrally or by a combination of a plurality of different colors, Alternatively, the present invention is extremely effective for an apparatus having at least one of full-color recording modes by color mixing.
[0136]
In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, ink that is solidified at room temperature or lower and that softens or liquefies at room temperature may be used. In the ink jet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that it is in the stable discharge range. A liquid material may be used. In addition, it is solidified and heated in an untreated state in order to actively prevent the temperature rise caused by thermal energy from being used as the energy for changing the state of the ink from the solid state to the liquid state, or to prevent the ink from evaporating. You may use the ink which liquefies by. In any case, by applying thermal energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case where ink having a property of being liquefied for the first time is used. The ink in such a case is in a state of being held as a liquid or a solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, the electrothermal converter may be opposed to the electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.
[0137]
In addition, the ink jet recording apparatus according to the present invention may be used as an image output terminal of an information processing device such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. The thing etc. may be sufficient.
[0138]
【Effect of the invention】
As described above, according to the present invention, the maximum density of light dots is increased, the density area formed only by the light ink dots is widened, and the density area where the dark dots that are easily noticeable are formed. Since the formation amount of the low density dot and the high density dot is optimally set so as to narrow, the granularity of the dot can be reduced over the entire density area.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external configuration of an ink jet 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 a printer according to an 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.
6 (a) and 6 (b) are diagrams illustrating a configuration of a scanner cartridge that can be mounted on a printer according to an embodiment of the present invention instead of the recording head cartridge of FIG. FIG.
FIG. 7 is a block diagram schematically showing an overall configuration of an electrical circuit in a printer according to an 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 exemplary operation of a printer according to an embodiment of the present invention.
FIG. 11 is a schematic configuration diagram of the recording head used in the first embodiment, which is a characteristic component of the present invention, as viewed from the nozzle side.
12 is an explanatory diagram when a plurality of recording heads of FIG. 11 are used.
13 is an enlarged sectional view taken along line XIII-XIII in FIG.
FIG. 14 is an explanatory diagram of a relationship between dark ink and light ink ejection amounts and reflection density;
FIG. 15 is a diagram illustrating a relationship between each gradation level (density level) and dark ink and light ink placement amounts in the related art.
FIG. 16 is a diagram showing a relationship between each gradation level (density level) and dark ink and light ink placement amounts in the first embodiment of the characteristic component of the present invention.
FIG. 17 is an explanatory diagram of a specific comparative example of a conventional LUT and an LUT used in the present invention.
18 is an explanatory diagram of a contrast difference between dark and light inks in FIGS. 15 and 16. FIG.
FIG. 19 is an explanatory diagram of a relationship between a pixel and a dot.
FIG. 20 is an explanatory diagram of a relationship between a dot area and a unit pixel area.
FIG. 21 is an explanatory diagram of a relationship between resolution and (dot area / unit pixel area);
FIGS. 22A and 22B are explanatory diagrams of the relationship between pixels and dots at different resolutions. FIGS.
FIG. 23 is a block diagram of an image data processing portion in the first embodiment of the characteristic components of the present invention.
24 is an explanatory diagram of a light ink index pattern used in the image data processing portion of FIG. 23. FIG.
FIG. 25 is an explanatory diagram of a correlation between a granularity evaluation function value and a subjective evaluation;
FIG. 26 is a diagram illustrating a relationship between each gradation level (density level) and a light and dark dot index pattern.
[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
H1600d communication path

Claims (12)

In a recording apparatus capable of recording an image on a recording medium using a first ink and a second ink having a color similar to the first ink and having a higher density than the first ink,
The maximum amount of the first ink applied to the unit area of the recording medium according to the gradation level of the image is 1.75 times or more the maximum amount of the second ink applied to the unit area. The application amount of the first ink decreases as the gradation level increases beyond the gradation level when the application amount of the first ink reaches the maximum amount, and the gradation level is reduced. Maintain zero until the maximum gradation level after becoming zero when lower than the maximum gradation level,
In the second ink gradation levels that began with the first ink gradation level or higher gradation level when the applying amount reaches 1.75 times the maximum amount of the second ink And a gradation level including a range equal to or lower than the gradation level when the application amount of the first ink reaches the maximum amount,
The number of gradation levels that can be expressed in the unit area by the first ink is larger than the number of gradation levels that can be expressed in the unit area by the second ink . . In the range from the low gradation level to the high gradation level of the color represented by the input image data indicating the image to be recorded in the unit area, the first ink application amount as the gradation level increases the reduced reaches the maximum application amount of the first maximum application amount ink the first increased to the ink, and the same or even more to as the first ink maximum application amount to the corresponding gradation level of in accordance with the gradation level rises from a small predetermined gradation level, to increase the application amount of the second ink to the maximum application amount of small second ink than the maximum application amount of the first ink As described above, based on the input image data, the first image data corresponding to the application amount of the first ink to the unit region and the second ink for the unit region. The recording apparatus according to claim 1, characterized in that Ru provided with generating means for generating a second image data corresponding to the given amount.   The recording apparatus according to claim 2, wherein the input image data is RGB data. Granularity G in the granularity evaluation function of an image recorded in the unit area corresponding to each gradation level within a range of gradation levels corresponding to the maximum application amount of the second ink from the predetermined gradation level. Is 0.6 or less,
3. The recording apparatus according to claim 2, wherein the granularity evaluation function is expressed by the following expression, with a standard deviation of pixel values in an image P ′ obtained by applying a visual filter to the image P as a granularity G: .

i: Pixel position in X direction j: Pixel position in Y direction N: Size of image P in X direction and Y direction An image for generating image data for recording an image on a recording medium using the first ink and a second ink having a color similar to the first ink and having a higher density than the first ink. A processing device comprising:
The amount of the first ink applied to the unit region and the amount of the second ink applied to the unit region based on the input image data indicating the gradation level of the image to be recorded in the unit region of the recording medium Comprising generating means for generating image data corresponding to
The generating means sets the maximum amount of the first ink applied to the unit region to 1.75 times or more the maximum amount of the second ink applied to the unit region, and applies the first ink. The amount is decreased as the gradation level increases beyond the gradation level when the application amount of the first ink reaches the maximum amount, and the gradation level is lower than the maximum gradation level. 1 after a zero when maintaining zero to the maximum gradation level, the gradation level that started with the second ink, application amount of the first ink is the maximum amount of the second ink A gradation level that is equal to or higher than the gradation level when it reaches .75 times and includes a range that is equal to or less than the gradation level when the application amount of the first ink reaches the maximum amount. , which can be expressed in the unit area by the first ink The number of stages of adjustment, said to more than step number representable gradation in the unit area by a second ink, the image processing apparatus and generates the image data. It said generating means, said input in a low gradation level of colors expressed by the image data within a range that leads to high tone levels, the following gradation level is high, the first grant of the first ink Is gradually increased to the maximum application amount of the first ink , and is decreased when the maximum application amount of the first ink is reached, and is equal to or smaller than the gradation level corresponding to the maximum application amount of the first ink. in accordance with the gray level from the gray level becomes high in so as to increase the application amount of the second ink to the maximum application amount of small second ink than the maximum application amount of the first ink The image processing apparatus according to claim 5, wherein the image data is generated. The maximum application amount of the first ink to be applied to a unit area, the image processing apparatus according to claim 5, wherein the grant to the unit area the is second maximum application amount of 2 times or more.   8. The generation unit according to claim 5, wherein the generation unit generates the image data corresponding to the number of dots of the first ink and the number of dots of the second ink to be formed for the unit region. An image processing apparatus according to any one of the above.   The image processing apparatus according to claim 5, wherein the input image data is RGB data. Data for generating image data for recording an image on a recording medium using the first ink and the second ink having the same color as the first ink and having a higher density than the first ink. A generation method,
The amount of the first ink applied to the unit region and the amount of the second ink applied to the unit region based on the input image data indicating the gradation level of the image to be recorded in the unit region of the recording medium Including a generation process for generating image data corresponding to
In the generating step, the maximum amount of the first ink applied to the unit region is set to 1.75 times or more the maximum amount of the second ink applied to the unit region, and the application of the first ink is performed. The amount is decreased as the gradation level increases beyond the gradation level when the application amount of the first ink reaches the maximum amount, and the gradation level is lower than the maximum gradation level. 1 after a zero when maintaining zero to the maximum gradation level, the gradation level that started with the second ink, application amount of the first ink is the maximum amount of the second ink A gradation level that is equal to or higher than the gradation level when it reaches .75 times and includes a range that is equal to or less than the gradation level when the application amount of the first ink reaches the maximum amount. , which can be expressed in the unit area by the first ink Data generating method step number of tone, to the to more than the number of stages of gradation representable by the unit area by a second ink, characterized in that to generate the image data.   A computer program for causing a computer to execute the data generation method according to claim 10. A recording apparatus capable of recording an image on a recording medium using a first ink and a second ink having a color similar to the first ink and having a higher density than the first ink; and the recording A data supply apparatus for supplying image data indicating a gradation level of an image to be recorded in the apparatus,
The maximum amount of the first ink applied to the unit area of the recording medium based on the image data is the maximum amount of the second ink applied to the unit area based on the image data. The amount of the first ink applied decreases as the gradation level increases beyond the gradation level when the first ink application amount reaches the maximum amount. In addition, when the gradation level is lower than the maximum gradation level, the zero is maintained until the maximum gradation level from zero.
In the second ink gradation levels that began with the first ink gradation level or higher gradation level when the applying amount reaches 1.75 times the maximum amount of the second ink And a gradation level including a range equal to or lower than the gradation level when the application amount of the first ink reaches the maximum amount,
The number of gradation levels that can be expressed in the unit area by the first ink based on the image data is the number of gradation levels that can be expressed in the unit area by the second ink based on the image data . Recording system characterized by more than the number of stages .

Images