JP4057448B2

JP4057448B2 - Electrophotographic photoreceptor test equipment

Info

Publication number: JP4057448B2
Application number: JP2003057862A
Authority: JP
Inventors: 紀保齋藤; 潔増田
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2003-03-04
Filing date: 2003-03-04
Publication date: 2008-03-05
Anticipated expiration: 2023-03-04
Also published as: JP2004271550A

Description

【０００１】
【発明の属する技術分野】
本発明は、電位測定装置に関し、更に詳しくは、レーザープリンター・複写機等の画像形成装置に使用される電子写真用感光体の検査、さらに、誘電体薄膜の非接触・非破壊の電気特性測定にも応用可能な装置の改良に関する。
【０００２】
【従来の技術】
従来技術として、電子写真感光体の試料片をセットする開口部を持つターンテーブルと、該ターンテーブルを高速回転させるための手段と、ターンテーブルに対向して配置され該感光体試料片を徐々に帯電させるコロナ帯電器と、ターンテーブルの開口部に装着された感光体試験片表面の平均帯電電位と感光体試料片に流れ込む電流を同時に計測する為の手段とを有し、該電流は時間で積分され充電電荷として処理され、Ｑ＝Ｃ・Ｖの関係式より感光体試料片の静電容量を非破壊、非接触で測定する装置が知られている。
この装置は、感光体試料片の静電容量の測定時に高速回転するターンテーブルの感光体試料片に流れ込む電流に対する真の電流を算出し、静電容量の測定精度を向上した測定装置である（例えば、特許文献１参照）。
【特許文献１】
特開平１０−２８２０５７号公報
【０００３】
【発明が解決しようとする課題】
電子写真用感光体に要求される特性として、帯電能、電荷保持能、感度等があげられる。これらの各特性の評価には、電子写真プロセスと同様にコロナ帯電・露光を行うことによって上記各特性を評価する方法が用いられることが多い。
上記各特性を評価する装置の例として、概略構成図の図１に示す様な、電子写真用感光体試料片の特性評価装置が知られている。この特性評価装置の測定方法の具体例として、ターンテーブル１には感光体試料片を装着する開口部３が設けられており、開口部３の大きさは、例えば、中心から見て４４°の開口角度をもち、面積は１９．３６ｃｍ^２（開口部：４４×４４ｍｍ）である。また、ターンテーブル１に付属して導電性金属板からなる試料片押さえ板２が設けられている。
また、ターンテーブル１は、開口部３によって保持された感光体試料片をコロナ帯電器４に対向静止させるような位置で停止することができ、また、実機と同程度のスピードで回転させることができ、また、試料片を帯電させて帯電の立ちあがりの様子を観察する為、高速で回転させて試料片をコロナ帯電器４に何度も通過させることができるようになっている。
【０００４】
コロナ帯電器４から試料片に与えられ試料片を充電するパルス電流は、所定の検出間隔で電流計６に送られその中の平滑化回路で平滑化等がされた後、Ａ／Ｄ変換器８で変換されコントローラ９に送られ演算処理される。
また、試料片の表面電位は、コロナ帯電器４と別の位置に配置された表面電位計７のモニタ部である表面電位計電極５でモニタされ、モニタされた信号は所定の検出間隔で表面電位計７に送られ、その中の増幅器で増幅等がされた後、Ａ／Ｄ変換器８で変換され、コントローラ９に送られ演算処理される。
このような電子写真用感光体試料片特性評価装置の計測により算出される帯電能・電荷保持性能・感度等の特性評価において、正確な電位計測は必要条件であり正確な計測により精度の良い特性値が得られる。また、この測定装置では、帯電した感光体の電荷が漏洩しないようサンプル台に絶縁性の皮膜を覆わせ、測定を行なっている。
しかしながら、電子写真用感光体をコロナ放電により劣化させ、劣化後の特性を測定する場合、常湿環境下では問題無く測定できても、高湿環境下においては予測される以上の帯電特性の劣化が見られることが有る（電位測定結果は図２、電流測定結果は図３参照）。これはサンプルの環境に依存した特性ではなく、計測の問題であることが推測されていたが原因が不明であった。
本発明者はこの問題を鋭意検討し、斯かる現象は、コロナ放電により、オゾン・ＮＯｘ等の放電生成物が、高湿環境下において水分と吸着し、電子写真用感光体の表面抵抗を低下させ、電子写真用感光体の表面の電荷が横方向に動きやすくなり、サンプル台の絶縁性の膜に覆われていない窓枠部分に漏洩してしまうことが原因で発生することがわかった。このため、高湿環境下でも正確に測定できる電子写真用感光体試験装置が要望されていた。
ところで、上記従来技術である特開平１０−２８２０５７号公報には、図１のような電子写真感光体試料片の特性値評価装置を利用しての静電容量算出方法について述べられている。しかしながら、この従来技術では電位計測に関する詳細は述べられておらず、高湿環境下での使用時に電位計測を正確に行うことができないという問題があった。
そこで本発明は上記の問題点を解決するためになされたもので、高湿環境下でも正確に測定できる電子写真用感光体試験装置を提供することを目的とする。
【０００５】
【課題を解決するための手段】
前記の課題を解決するために、請求項１記載の発明では、電子写真用感光体試料片をセット可能な開口部を持つターンテーブルと、ターンテーブルを高速で回転させる回転駆動手段と、を備え、帯電及び露光手段により電子写真用感光体の特性を評価する電子写真用感光体試験装置において、ターンテーブルのサンプル設置面及び該設置面に対して垂直であるサンプル窓枠部分が絶縁性の皮膜により被覆されていることを特徴とする電子写真用感光体試験装置を最も主要な特徴とする。
請求項２記載の発明は、請求項１記載の電子写真用感光体試験装置において、ターンテーブルのサンプル窓枠部分のサイズより、被試験体の電位を計測する電位計による測定面積を小面積にし、ターンテーブル回転中に該面積がサンプル測定サイズ内に収まる面積にした電子写真用感光体試験装置を主要な特徴とする。
請求項３記載の発明は、請求項２記載の電子写真用感光体試験装置において、感光体試料片の電位計測を行うゲート時間は、電位計がサンプル測定サイズ内の位置に存在する時間内である電子写真用感光体試験装置を主要な特徴とする。
請求項４記載の発明は、電子写真用感光体試料片をセット可能な開口部を持つターンテーブルと、ターンテーブルを高速回転する手段と、帯電及び露光手段を有する電子写真用感光体の特性値評価試験装置において、ターンテーブルのサンプル台に、ターンテーブルのサンプル窓枠部分のサイズより小さな開口部を持った絶縁性の薄膜を設置し、その上に感光体試料片を設置して感光体特性値を測定する電子写真用感光体試験装置を主要な特徴とする。
請求項５記載の発明は、請求項４記載の電子写真用感光体試験装置において、絶縁性薄膜の開口部サイズより、被試験体の電位を計測する電位計による測定面積を小面積にし、ターンテーブル回転中に該面積が絶縁性薄膜の開口部サイズ内に収まる電子写真用感光体試験装置を主要な特徴とする。
請求項６記載の発明は、請求項５記載の電子写真用感光体試験装置において、感光体試料片の電位計測を行うゲート時間は、電位計が絶縁性薄膜の開口部サイズ内の位置に存在する時間内である電子写真用感光体試験装置を主要な特徴とする。
【０００６】
【発明の実施の形態】
以下、図面により本発明の実施の形態を詳細に説明する。以下に、本発明の実施の形態を図面に基づいて説明する。本発明に係る電子写真用感光体の特性評価装置は従来測定装置と同様、図１に示す装置を使用する。
まず測定に先立ち、開口部３に感光体試料片を装着せずに試料片押さえ板２にて開口部３を塞ぎ、この開口部３がコロナ帯電器４の真上にくるようにして静止させる。コロナ帯電器４の放電を開始し、試料片押さえ板２に流れる電流値を検出し、所定の値（ここでは−１８μＡ）に調整する。
次に、開口部３に感光体の試料片を感光面が下向きになるように装着して、試料片押さえ板２により固定し、ターンテーブル１をモータ等の回転駆動手段によって所定の回転数になるよう回転させる。回転が安定したところでコロナ帯電器４により放電を開始し、帯電能・電荷保持性能・感度等の特性値を計測する。
【０００７】
＜実施例１＞
図１と同様の特性評価装置を用いて、感光体試料片（リコーＳＰ２０００用感光体と同じ材料・処方構成の試料片）を高速で回転し（回転数：１０００ｒｐｍ）、コロナ帯電・露光を行い、感光体試料片を劣化させた（感光体表面電位：−８００Ｖ、感光体通過電流：−５．６μＡに維持した状態で感光体試料片を１時間劣化させた）。その後、高湿環境下（湿度８０％）で図１の特性評価装置を用いて、感光体試料片の電気特性（２０秒間帯電し２０秒暗減衰した時の電位推移）を測定した。
その際、ターンテーブルのサンプル窓枠部分まで絶縁性の皮膜（材質：テフロン（登録商標））で覆い（図４参照）、更に電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し測定した。
電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定するような構造とした場合を実施例１とする。また、劣化感光体を測定する際、高湿環境下（湿度８０％）でターンテーブルのサンプル窓枠部分に何もせず、金属部分が剥き出しの状態で、電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定するような構造とした場合を比較例１とする。暗減衰率（２０秒帯電後の電位と、その後２０秒間暗減衰させた後の電位の比率）の結果と、その時の電位と電流の推移についての状況結果を表１に示す。
【表１】
表１の結果から、高湿環境下でもターンテーブルのサンプル窓枠部分に絶縁性の皮膜を覆うことにより、サンプル窓枠部分への電位の漏洩を防ぐことができ、常湿環境下と同様の電気特性結果（帯電特性・暗減衰特性）を得ることができ、精度の高い特性値を算出することが可能となることが分かる。
【０００８】
＜実施例２＞
図１と同様の特性評価装置を用いて、感光体試料片（リコーＳＰ２０００用感光体と同じ材料・処方構成の試料片）を高速で回転し（回転数：１０００ｒｐｍ）、コロナ帯電・露光を行い、感光体試料片を劣化させた（感光体表面電位：−８００Ｖ、感光体通過電流：−５．６μＡに維持した状態で感光体試料片を１時間劣化）。その後、高湿環境下（湿度８０％）で図１の特性評価装置を用いて、感光体試料片の電気特性を測定した（２０秒間帯電し２０秒間暗減衰させ、３０秒間露光を行なった時の電位推移）。
その際、ターンテーブルのサンプル窓枠部分まで絶縁性の皮膜（材質：テフロン（登録商標））で覆い（図４参照）、更に電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは３５ｍｍ×３５ｍｍの物を使用し測定した。メッシュコーティング部はサンプル測定サイズ内に収まることが可能な位置に存在し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定する構造とした場合を実施例２とする。
【０００９】
また、劣化感光体を測定する際、常湿環境下（湿度５５％）でターンテーブルのサンプル窓枠部分に何もせず、金属部分が剥き出しの状態で電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定する構造とした場合を比較例２とする。３０秒間露光を行なった後の残留電位の結果を表２に示す。
【表２】
表２の結果から、サンプル窓枠部分に絶縁性の皮膜で覆うことにより、残留電位の上昇が確認されるが、電位計の測定する面積を、ターンテーブルのサンプル窓枠部分のサイズより小さくすることにより、残留電位の上昇を抑えることができることが分かる。
【００１０】
＜実施例３＞
図１と同様の特性評価装置を用いて、感光体試料片（リコーＳＰ２０００用感光体と同じ材料・処方構成の試料片）を高速で回転し（回転数：１０００ｒｐｍ）、コロナ帯電・露光を行い、感光体試料片を劣化させた。（感光体表面電位：−８００Ｖ、感光体通過電流：−５．６μＡに維持した状態で感光体試料片を１時間劣化）その後、高湿環境下（湿度８０％）で図１の特性評価装置を用いて、感光体試料片の電気特性を測定した。その際、ターンテーブルのサンプル窓枠部分まで絶縁性の皮膜（材質：テフロン（登録商標））で覆い（図４参照）、更に電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは３５ｍｍ×３５ｍｍの物を使用し測定した。メッシュコーティング部はサンプル測定サイズ内に収まることが可能な位置に存在し、電位を測定するゲート時間は、電位計が測定する面積がサンプル測定サイズ内の位置に存在する時間となる構造で測定した場合を実施例３とする。
また、劣化感光体を測定する際、常湿環境下（湿度５５％）でターンテーブルのサンプル窓枠部分に何もせず、金属部分が剥き出しの状態で電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定する構造とした場合を比較例３とする。残留電位の結果を表３に示す。
【表３】
表３の結果から、サンプル窓枠部分を絶縁性の皮膜で覆い、電位計の測定する面積を、ターンテーブルのサンプル窓枠部分のサイズより小さくし、更に電位を測定するゲート時間を、電位計が測定する面積がサンプル測定サイズ内の位置に存在する時間で測定することにより、残留電位の上昇を防ぎ正確な測定ができることが分かる。
【００１１】
＜実施例４＞
図１と同様の特性評価装置を用いて、感光体試料片（リコーＳＰ２０００用感光体と同じ材料・処方構成の試料片）を高速で回転し（回転数：１０００ｒｐｍ）、コロナ帯電・露光を行い、感光体試料片を劣化させた。（感光体表面電位：−８００Ｖ、感光体通過電流：−５．６μＡに維持した状態で感光体試料片を１時間劣化）その後、高湿環境下（湿度８０％）で図１の特性評価装置を用いて、感光体試料片の電気特性（２０秒間帯電し２０秒暗減衰した時の電位推移）を測定した。その際、ターンテーブルのサンプル台に開口部を持つ絶縁性の薄膜（厚さ：１０μｍ、材質：テフロン（登録商標）、大きさ：５５×５５ｍｍ、開口部大きさ：４３×４３ｍｍ）を置いた上にサンプルを置いた（図５参照）。更に電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し測定した。
【００１２】
電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定するような構造とした場合を実施例４とする。また、劣化感光体を測定する際、高湿環境下（湿度８０％）でターンテーブルのサンプル台に何も置かず、そのままサンプルを置き、電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定するような構造とした場合を比較例４とする。暗減衰率（２０秒帯電後の電位と、その後２０秒間暗減衰させた後の電位の比率）の結果と、その時の電位と電流の推移についての状況結果を表４に示す。
【表４】
表４の測定結果から、高湿環境下でターンテーブルのサンプル台に開口部を持つ絶縁性の薄膜を置き、その上にサンプルを乗せて測定することにより、サンプル窓枠部分への電荷の漏洩を防ぎ、常湿環境下と同様の電気特性結果（帯電特性・暗減衰特性）を得ることができ、精度の高い特性値を算出することが可能となることが分かる。
【００１３】
＜実施例５＞
図１と同様の特性評価装置を用いて、感光体試料片（リコーＳＰ２０００用感光体と同じ材料・処方構成の試料片）を高速で回転し（回転数：１０００ｒｐｍ）、コロナ帯電・露光を行い、感光体試料片を劣化させた。（感光体表面電位：−８００Ｖ、感光体通過電流：−５．６μＡに維持した状態で感光体試料片を１時間劣化）その後、高湿環境下（湿度８０％）で図１の特性評価装置を用いて、感光体試料片の電気特性を測定した（２０秒間帯電し２０秒間暗減衰させ、３０秒間露光を行なった時の電位推移）。
その際、ターンテーブルのサンプル台に開口部を持つ絶縁性の薄膜（厚さ：１０μｍ、材質：テフロン（登録商標）、大きさ：５５×５５ｍｍ、開口部大きさ：４３×４３ｍｍ）を置いた上にサンプルを置いた（図５参照）。
更に、電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは３５ｍｍ×３５ｍｍの物を使用し測定した。メッシュコーティング部は絶縁性薄膜開口部内に収まることが可能な位置に存在し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定する構造とした場合を実施例５とする。
【００１４】
また、劣化感光体を測定する際、高湿環境下（湿度８０％）でターンテーブルサンプル台に何も置かず、そのままサンプルを置き、電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定する構造とした場合を比較例５ａとする。
また、劣化感光体を測定する際、常湿環境下（湿度５５％）でターンテーブルサンプル台に何も置かず、そのままサンプルを置き、電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定する構造とした場合を比較例５ｂとする。３０秒間露光を行なった後の残留電位の結果を表５に示す。
【表５】
表５の結果から、ターンテーブルのサンプル台に開口部を持った絶縁性の薄膜を置くことにより、残留電位の上昇が確認されるが、絶縁性薄膜の開口部サイズより、被試験体の電位を計測する電位計の測定する面積の方を小さくすることにより、残留電位の上昇を抑えることができることが分かる。
【００１５】
＜実施例６＞
図１と同様の特性評価装置を用いて、感光体試料片（リコーＳＰ２０００用感光体と同じ材料・処方構成の試料片）を高速で回転し（回転数：１０００ｒｐｍ）、コロナ帯電・露光を行い、感光体試料片を劣化させた。（感光体表面電位：−８００Ｖ、感光体通過電流：−５．６μＡに維持した状態で感光体試料片を１時間劣化）その後、高湿環境下（湿度８０％）で図１の特性評価装置を用いて、感光体試料片の電気特性を測定した。
その際、ターンテーブルのサンプル台に開口部を持つ絶縁性の薄膜（厚さ：１０μｍ、材質：テフロン（登録商標）、大きさ：５５×５５ｍｍ、開口部大きさ：４３×４３ｍｍ）を置いた上にサンプルを置いた（図５参照）。更に電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは３５ｍｍ×３５ｍｍの物を使用し測定した。メッシュコーティング部は絶縁性薄膜開口部内に収まることが可能な位置に存在し、電位を測定するゲート時間は、電位計が測定する面積がサンプル測定サイズ内の位置に存在する時間となる構造で測定した場合を実施例６とする。
【００１６】
また、劣化感光体を測定する際、常湿環境下（湿度５５％）でターンテーブルのサンプル台に何も置かず、電位計測は石英ガラス片面をメッシュ状にネサコーティングされたＮＥＳＡ静電容量型電位計を利用し、メッシュコーティング部の大きさは５０ｍｍ×５０ｍｍの物を使用し、電位を測定するゲート時間は、電位計が測定する面積が感光体試料片の一部にかかった時点から、感光体試料片が測定可能な位置から抜けた時点まで測定する構造とした場合を比較例６とする。残留電位の結果を表６に示す。
【表６】
表６の結果から、ターンテーブルのサンプル台に開口部を持つ絶縁性の薄膜をのせ、その上にサンプルを置き、電位計の測定する面積を、絶縁性薄膜の開口部サイズより小さくし、更に電位を測定するゲート時間を、電位計が測定する面積が絶縁性薄膜の開口部サイズ内の位置に存在する時間で測定することにより、残留電位の上昇を防ぎ正確な測定ができることが分かる。
【００１７】
【発明の効果】
以上説明したように、請求項１によれば、電子写真用感光体試料片をセット可能な開口部を持つターンテーブルと、ターンテーブルを高速で回転させる手段と、帯電及び露光手段により電子写真用感光体の特性を評価する試験装置において、ターンテーブルのサンプル設置面及び／又は該設置面に対して垂直であるサンプル窓枠部分を絶縁性の皮膜により被覆することを特徴とする電子写真用感光体試験装置により、測定中に電子写真用感光体の電荷がサンプル窓枠部分へ漏洩するのを防ぐことができる。
請求項２の電子写真用感光体試験装置において、請求項１記載の電子写真用感光体試験装置において、ターンテーブルのサンプル窓枠部分のサイズより、被試験体の電位を計測する電位計による測定面積を小面積にし、ターンテーブル回転中に該面積がサンプル測定サイズ内に収まる面積にしたことを特徴とする電子写真用感光体試験装置により、被試験体以外の電位計測を抑えることができる。
請求項３の電子写真用感光体試験装置において、請求項２記載の電子写真用感光体試験装置において、感光体試料片の電位計測を行うゲート時間は、電位計がサンプル測定サイズ内の位置に存在する時間内であることを特徴とする電子写真用感光体試験装置により、必要無い部分の電位計測を行なわず、被試験体のみの電位計測を行うことができる。
請求項４の電子写真用感光体試験装置において、電子写真用感光体試料片をセット可能な開口部を持つターンテーブルと、ターンテーブルを高速回転する手段と、帯電及び露光手段を有する電子写真用感光体の特性値評価試験装置において、ターンテーブルのサンプル台に、ターンテーブルのサンプル窓枠部分のサイズより小さな開口部を持った絶縁性の薄膜を設置し、その上に感光体試料片を設置して感光体特性値を測定することを特徴とする電子写真用感光体試験装置により、測定中に電子写真用感光体の電荷がサンプル窓枠部分へ漏洩するのを防ぐことができる。
請求項５の電子写真用感光体試験装置において、請求項４記載の電子写真用感光体試験装置において、絶縁性薄膜の開口部サイズより、被試験体の電位を計測する電位計による測定面積を小面積にし、ターンテーブル回転中に該面積が絶縁性薄膜の開口部サイズ内に収まることを特徴とする電子写真用感光体試験装置により、被試験体以外の電位計測を抑えることができる。
請求項６の電子写真用感光体試験装置において、請求項５記載の電子写真用感光体試験装置において、感光体試料片の電位計測を行うゲート時間は、電位計が絶縁性薄膜の開口部サイズ内の位置に存在する時間内であることを特徴とする電子写真用感光体試験装置により、必要無い部分の電位計測を行なわず、被試験体のみの電位計測を行うことができる。
【図面の簡単な説明】
【図１】従来及び本発明に使用の電子写真感光体試料特性評価装置の概略構成図。
【図２】本発明の評価装置サンプル台被覆による表面電位測定結果を示す説明図。
【図３】本発明の評価装置サンプル台被覆による充電電流測定結果を示す説明図。
【図４】本発明の評価装置のサンプル台窓枠部分皮膜被覆を示す説明図。
【図５】本発明の評価装置のサンプル台開口部皮膜被覆を示す説明図。
【符号の説明】
１ターンテーブル、２試料片押え板、３開口部、４コロナ帯電器、５表面電位計電極部・露光装置、６電流計測・平滑化回路、他、７表面電位計：アンプ回路、他、８インターフェイス（Ａ／Ｄ変換）、９コントローラ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric potential measuring device, and more specifically, inspection of an electrophotographic photosensitive member used in an image forming apparatus such as a laser printer or a copying machine, and non-contact / non-destructive electrical property measurement of a dielectric thin film. The present invention also relates to improvements in devices that can also be applied.
[0002]
[Prior art]
As a conventional technique, a turntable having an opening for setting a sample piece of an electrophotographic photosensitive member, means for rotating the turntable at a high speed, and the photosensitive member sample piece arranged gradually facing the turntable are gradually removed. A corona charger for charging, and means for simultaneously measuring the average charged potential of the surface of the photoconductor test piece mounted on the opening of the turntable and the current flowing into the photoconductor sample piece. An apparatus is known that integrates and processes as a charged charge, and measures the electrostatic capacity of the photoconductor sample piece in a non-destructive and non-contact manner from the relational expression Q = C · V.
This device is a measuring device that calculates the true current with respect to the current flowing into the photoconductor sample piece of the turntable that rotates at high speed when measuring the capacitance of the photoconductor sample piece, thereby improving the measurement accuracy of the capacitance ( For example, see Patent Document 1).
[Patent Document 1]
Japanese Patent Laid-Open No. 10-282057
[Problems to be solved by the invention]
Characteristics required for the electrophotographic photoreceptor include charging ability, charge retention ability, sensitivity, and the like. In order to evaluate each of these characteristics, a method of evaluating each of the above characteristics by performing corona charging / exposure in the same manner as the electrophotographic process is often used.
As an example of an apparatus for evaluating the above characteristics, an apparatus for evaluating characteristics of an electrophotographic photosensitive member sample piece as shown in FIG. 1 of a schematic configuration diagram is known. As a specific example of the measuring method of this characteristic evaluation apparatus, the turntable 1 is provided with an opening 3 for mounting a photoconductor sample piece, and the size of the opening 3 is, for example, 44 ° when viewed from the center. It has an opening angle and the area is 19.36 cm ² (opening: 44 × 44 mm). Further, a sample piece pressing plate 2 made of a conductive metal plate is attached to the turntable 1.
Further, the turntable 1 can be stopped at a position where the photoconductor sample piece held by the opening 3 is opposed to the corona charger 4 and can be rotated at the same speed as the actual machine. In addition, since the sample piece is charged and the state of the rising of the charge is observed, the sample piece can be passed through the corona charger 4 many times by rotating at high speed.
[0004]
The pulse current applied to the sample piece from the corona charger 4 and charged to the sample piece is sent to the ammeter 6 at a predetermined detection interval, smoothed by a smoothing circuit therein, and then A / D converter. 8 is converted and sent to the controller 9 for arithmetic processing.
Further, the surface potential of the sample piece is monitored by a surface potential meter electrode 5 which is a monitor unit of the surface potential meter 7 arranged at a position different from the corona charger 4, and the monitored signal is detected at a predetermined detection interval. After being sent to the electrometer 7 and amplified by an amplifier therein, it is converted by the A / D converter 8 and sent to the controller 9 for arithmetic processing.
In the evaluation of characteristics such as chargeability, charge retention performance, and sensitivity calculated by the measurement of the electrophotographic photosensitive member sample piece characteristic evaluation apparatus, accurate potential measurement is a necessary condition, and accurate characteristics are obtained through accurate measurement. A value is obtained. Further, in this measuring apparatus, measurement is performed by covering the sample table with an insulating film so that the charge of the charged photoreceptor is not leaked.
However, when electrophotographic photoconductors are deteriorated by corona discharge and the characteristics after deterioration are measured, the charging characteristics are deteriorated more than expected in a high humidity environment, even if it can be measured without problems in an ordinary humidity environment. (See FIG. 2 for potential measurement results and FIG. 3 for current measurement results). Although this was not a characteristic depending on the environment of the sample, it was presumed to be a measurement problem, but the cause was unknown.
The present inventor diligently studied this problem, and this phenomenon was caused by corona discharge, which caused discharge products such as ozone and NOx to be adsorbed with moisture in a high humidity environment, thereby reducing the surface resistance of the electrophotographic photoreceptor. It was found that the charge on the surface of the electrophotographic photosensitive member tends to move in the lateral direction and leaks to the window frame portion not covered with the insulating film of the sample table. For this reason, there has been a demand for an electrophotographic photoreceptor test apparatus that can accurately measure even in a high humidity environment.
Incidentally, Japanese Patent Laid-Open No. 10-282057, which is the above prior art, describes a capacitance calculation method using a characteristic value evaluation apparatus for an electrophotographic photosensitive member sample piece as shown in FIG. However, in this prior art, the details regarding the potential measurement are not described, and there is a problem in that the potential measurement cannot be accurately performed when used in a high humidity environment.
Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electrophotographic photoreceptor testing apparatus that can accurately measure even in a high humidity environment.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1, further comprising a turntable having a settable opening an electrophotographic photoreceptor sample piece, a rotary drive means for rotating the turntable at high speed, the In the electrophotographic photoreceptor testing apparatus for evaluating the characteristics of the electrophotographic photoreceptor by charging and exposing means, the sample installation surface of the turntable and the sample window frame portion perpendicular to the installation surface are insulative film The most important feature is an electrophotographic photosensitive member testing apparatus characterized in that it is coated with the above.
According to a second aspect of the present invention, in the electrophotographic photosensitive member testing apparatus according to the first aspect, the area measured by the electrometer for measuring the potential of the device under test is made smaller than the size of the sample window frame portion of the turntable. The main feature is an electrophotographic photosensitive member testing apparatus in which the area falls within the sample measurement size during rotation of the turntable.
According to a third aspect of the present invention, in the electrophotographic photoconductor testing device according to the second aspect, the gate time for measuring the potential of the photoconductor sample piece is within the time that the electrometer is present at a position within the sample measurement size. An electrophotographic photoreceptor testing device is a major feature.
According to a fourth aspect of the present invention, there is provided a characteristic value of a turntable having an opening capable of setting an electrophotographic photosensitive member sample piece, means for rotating the turntable at high speed, and charging and exposing means. In the evaluation test equipment, an insulating thin film with an opening smaller than the size of the sample window frame part of the turntable is installed on the sample table of the turntable, and a photoconductor sample piece is installed on the insulating thin film. The main feature is an electrophotographic photoreceptor test apparatus for measuring values.
According to a fifth aspect of the present invention, in the electrophotographic photosensitive member testing apparatus according to the fourth aspect, the measurement area by the electrometer for measuring the potential of the device under test is made smaller than the opening size of the insulating thin film. The main feature is an electrophotographic photoreceptor testing apparatus in which the area is within the opening size of the insulating thin film during table rotation.
According to a sixth aspect of the present invention, in the electrophotographic photosensitive member test apparatus according to the fifth aspect, the gate time for measuring the potential of the photosensitive member sample piece is located at a position within the opening size of the insulating thin film. The main feature is an electrophotographic photoconductor testing device that is within the time to perform.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Embodiments of the present invention will be described below with reference to the drawings. The apparatus for evaluating characteristics of an electrophotographic photoreceptor according to the present invention uses the apparatus shown in FIG. 1 as in the conventional measuring apparatus.
Prior to the measurement, the opening 3 is closed with the sample piece holding plate 2 without mounting the photosensitive member sample piece on the opening 3, and the opening 3 is stopped so as to be directly above the corona charger 4. . The discharge of the corona charger 4 is started, and the value of the current flowing through the sample piece pressing plate 2 is detected and adjusted to a predetermined value (here, −18 μA).
Next, the sample piece of the photosensitive member is mounted in the opening 3 so that the photosensitive surface faces downward, is fixed by the sample piece holding plate 2, and the turntable 1 is set to a predetermined number of rotations by a rotation driving means such as a motor. Rotate to When the rotation is stabilized, the corona charger 4 starts discharging and measures characteristic values such as charging ability, charge holding performance, and sensitivity.
[0007]
<Example 1>
Using the same characteristic evaluation apparatus as in FIG. 1, a photoconductor sample piece (a sample piece having the same material and composition as the Ricoh SP2000 photoconductor) is rotated at high speed (rotation speed: 1000 rpm), and corona charging and exposure are performed. The photoconductor sample piece was deteriorated (the photoconductor sample piece was deteriorated for 1 hour while maintaining the photoconductor surface potential: -800 V and the photoconductor passage current: -5.6 μA). Thereafter, using the characteristic evaluation apparatus shown in FIG. 1 in a high-humidity environment (humidity 80%), the electrical characteristics of the photoconductor sample pieces (the potential transition when charged for 20 seconds and dark decayed for 20 seconds) were measured.
At that time, the sample window frame part of the turntable is covered with an insulating film (material: Teflon (registered trademark)) (see FIG. 4), and further, the potential measurement is performed by NESA electrostatic coating with one side of quartz glass nesa-coated in a mesh shape. Using a capacitive electrometer, the size of the mesh coating portion was measured using a 50 mm × 50 mm object.
When measuring the potential, the gate time is measured from the time when the area measured by the electrometer is applied to a part of the photoconductor sample piece to the time when the photoconductor sample piece is removed from the measurable position. Is taken as Example 1. When measuring a deteriorated photoconductor, do not do anything on the sample window frame of the turntable in a high-humidity environment (humidity 80%). A NESA-coated NESA capacitance type electrometer is used, and a mesh coating portion having a size of 50 mm × 50 mm is used. The gate time for measuring the potential is the area measured by the electrometer is a photoconductor sample piece. Comparative Example 1 is a case where the structure is such that the measurement is performed from the time when a part of the photoconductor sample piece is removed from the position where the photoconductor sample piece can be measured. Table 1 shows the results of the dark decay rate (the ratio of the potential after charging for 20 seconds and the potential after the dark decay after 20 seconds) and the transition of the potential and current at that time.
[Table 1]
From the results in Table 1, it is possible to prevent potential leakage to the sample window frame part by covering the sample window frame part of the turntable with an insulating film even in a high humidity environment. It can be seen that electrical characteristics results (charging characteristics / dark decay characteristics) can be obtained, and it is possible to calculate highly accurate characteristic values.
[0008]
<Example 2>
Using the same characteristic evaluation apparatus as in FIG. 1, a photoconductor sample piece (a sample piece having the same material and composition as the Ricoh SP2000 photoconductor) is rotated at high speed (rotation speed: 1000 rpm), and corona charging and exposure are performed. The photoconductor sample piece was deteriorated (the photoconductor sample piece was deteriorated for 1 hour in a state where the photoconductor surface potential was maintained at −800 V and the photoconductor passage current was set at −5.6 μA). Thereafter, the electrical property of the photoconductor sample piece was measured using a characteristic evaluation apparatus shown in FIG. 1 in a high humidity environment (humidity 80%) (when charged for 20 seconds, dark attenuated for 20 seconds, and exposed for 30 seconds). Potential transition).
At that time, the sample window frame part of the turntable is covered with an insulating film (material: Teflon (registered trademark)) (see FIG. 4), and further, the potential measurement is performed by NESA electrostatic coating with one side of quartz glass nesa-coated in a mesh shape. Using a capacitive electrometer, the size of the mesh coating portion was measured using a 35 mm × 35 mm object. The mesh coating part is located at a position where it can fit within the sample measurement size, and the gate time for measuring the potential is from the point when the area measured by the electrometer reaches a part of the photoconductor sample piece. Example 2 is a case where the measurement is performed up to the point where the piece comes out of the measurable position .
[0009]
When measuring a deteriorated photoconductor, the sample window frame part of the turntable is not subjected to anything under normal humidity (humidity 55%), and the metal part is exposed. Using a coated NESA capacitance type electrometer, the mesh coating part has a size of 50 mm × 50 mm, and the gate time for measuring the potential is the area measured by the electrometer is the photoconductor sample piece. Comparative Example 2 is a case where the measurement is performed from the time when a part of the photoconductor sample piece is removed from the position where the photoconductor sample piece can be measured. Table 2 shows the results of residual potential after exposure for 30 seconds.
[Table 2]
From the results of Table 2, it is confirmed that the residual potential is increased by covering the sample window frame portion with an insulating film, but the area measured by the electrometer is made smaller than the size of the sample window frame portion of the turntable. Thus, it can be seen that an increase in the residual potential can be suppressed.
[0010]
<Example 3>
Using the same characteristic evaluation apparatus as in FIG. 1, a photoconductor sample piece (a sample piece having the same material and composition as the Ricoh SP2000 photoconductor) is rotated at high speed (rotation speed: 1000 rpm), and corona charging and exposure are performed. The photoconductor sample piece was deteriorated. (Photoconductor surface potential: -800 V, photoconductor passage current: -5.6 μA while maintaining the photoconductor sample piece for 1 hour) Thereafter, the characteristic evaluation apparatus of FIG. 1 in a high humidity environment (humidity 80%) Was used to measure the electrical characteristics of the photoreceptor sample pieces. At that time, the sample window frame part of the turntable is covered with an insulating film (material: Teflon (registered trademark)) (see FIG. 4), and further, the potential measurement is performed by NESA electrostatic coating with one side of quartz glass nesa-coated in a mesh shape. Using a capacitive electrometer, the size of the mesh coating portion was measured using a 35 mm × 35 mm object. The mesh coating part exists at a position where it can fit within the sample measurement size, and the gate time for measuring the potential was measured with a structure in which the area measured by the electrometer is the time at which the area within the sample measurement size exists The case is referred to as Example 3 .
When measuring a deteriorated photoconductor, the sample window frame part of the turntable is not subjected to anything under normal humidity (humidity 55%), and the metal part is exposed. Using a coated NESA capacitance type electrometer, the mesh coating part has a size of 50 mm × 50 mm, and the gate time for measuring the potential is the area measured by the electrometer is the photoconductor sample piece. Comparative Example 3 is a case where the measurement is performed from the time when a part of the photoconductor sample piece is taken to the time when the photoconductor sample piece is removed from the measurable position. The results of the residual potential are shown in Table 3.
[Table 3]
From the results in Table 3, the sample window frame part is covered with an insulating film, the area measured by the electrometer is made smaller than the size of the sample window frame part of the turntable, and the gate time for measuring the potential is determined by the electrometer. It can be seen that the measurement can be performed with the time required for the area to be measured at the position within the sample measurement size to prevent an increase in the residual potential and to perform an accurate measurement.
[0011]
<Example 4>
Using the same characteristic evaluation apparatus as in FIG. 1, a photoconductor sample piece (a sample piece having the same material and composition as the Ricoh SP2000 photoconductor) is rotated at high speed (rotation speed: 1000 rpm), and corona charging and exposure are performed. The photoconductor sample piece was deteriorated. (Photoconductor surface potential: -800 V, photoconductor passage current: -5.6 μA while maintaining the photoconductor sample piece for 1 hour) Thereafter, the characteristic evaluation apparatus of FIG. 1 in a high humidity environment (humidity 80%) Was used to measure the electrical characteristics of the photoconductor sample piece (potential transition when charged for 20 seconds and darkened for 20 seconds). At that time, an insulating thin film (thickness: 10 μm, material: Teflon (registered trademark), size: 55 × 55 mm, opening size: 43 × 43 mm) having an opening was placed on the sample table of the turntable. A sample was placed on top (see FIG. 5). Further, the potential measurement was performed using a NESA capacitance type electrometer in which one side of the quartz glass was nesa-coated in a mesh shape, and the size of the mesh coating portion was measured using a 50 mm × 50 mm object.
[0012]
When measuring the potential, the gate time is measured from the time when the area measured by the electrometer is applied to a part of the photoconductor sample piece to the time when the photoconductor sample piece is removed from the measurable position. This is referred to as Example 4. When measuring a deteriorated photoconductor, nothing was placed on the sample table of the turntable in a high-humidity environment (humidity 80%), and the sample was placed as it was. Using a NESA capacitance type electrometer, use a mesh coating part with a size of 50 mm x 50 mm. The gate time for measuring the potential is such that the area measured by the electrometer is part of the photoconductor sample piece. A case where the structure is such that the measurement is performed from the time when the photoconductor sample piece is removed from the position where the photoconductor sample piece can be measured is referred to as Comparative Example 4. Table 4 shows the result of the dark decay rate (the ratio between the potential after charging for 20 seconds and the potential after the dark decay after 20 seconds), and the status results regarding the transition of the potential and current at that time.
[Table 4]
From the measurement results in Table 4, the leakage of electric charges to the sample window frame part is measured by placing an insulating thin film with an opening on the sample table of the turntable in a high humidity environment and placing the sample on it. It can be understood that the same electrical characteristic results (charging characteristics and dark decay characteristics) as in the normal humidity environment can be obtained, and it is possible to calculate a characteristic value with high accuracy.
[0013]
<Example 5>
Using the same characteristic evaluation apparatus as in FIG. 1, a photoconductor sample piece (a sample piece having the same material and composition as the Ricoh SP2000 photoconductor) is rotated at high speed (rotation speed: 1000 rpm), and corona charging and exposure are performed. The photoconductor sample piece was deteriorated. (Photoconductor surface potential: -800 V, photoconductor passage current: -5.6 μA while maintaining the photoconductor sample piece for 1 hour) Thereafter, the characteristic evaluation apparatus of FIG. 1 in a high humidity environment (humidity 80%) Was used to measure the electrical characteristics of the photoreceptor sample piece (electric potential transition when charged for 20 seconds, darkened for 20 seconds and exposed for 30 seconds).
At that time, an insulating thin film (thickness: 10 μm, material: Teflon (registered trademark), size: 55 × 55 mm, opening size: 43 × 43 mm) having an opening was placed on the sample table of the turntable. A sample was placed on top (see FIG. 5).
Further, the potential measurement was performed using a NESA capacitance type electrometer in which one side of the quartz glass was nesa-coated in a mesh shape, and the size of the mesh coating portion was measured using a 35 mm × 35 mm object. The mesh coating portion is located at a position where it can be accommodated in the opening of the insulating thin film, and the gate time for measuring the potential is determined from the time when the area measured by the electrometer is applied to a part of the photosensitive sample piece. Example 5 is a case where the structure is such that the sample piece is measured from the measurable position until the sample piece is removed.
[0014]
When measuring a deteriorated photoconductor, the sample is placed as it is without placing anything on the turntable sample base in a high humidity environment (humidity 80%), and the potential measurement is performed with NESA coated on one side of a silica glass mesh. Use a capacitance-type electrometer, and use a mesh coating part with a size of 50 mm x 50 mm. The gate time for measuring the potential depends on the area measured by the electrometer on a part of the photoconductor sample piece. A case in which the measurement is performed from the point in time until the point where the photoconductor sample piece comes out of the measurable position is referred to as Comparative Example 5a.
Also, when measuring a deteriorated photoconductor, place nothing on the turntable sample base in an ambient humidity environment (humidity 55%), place the sample as it is, and the potential measurement is NESA with one side of the silica glass nesa-coated in a mesh shape. Use a capacitance-type electrometer, and use a mesh coating part with a size of 50 mm x 50 mm. The gate time for measuring the potential depends on the area measured by the electrometer on a part of the photoconductor sample piece. A case in which the measurement is performed from the point in time until the point where the photoconductor sample piece is removed from the measurable position is referred to as Comparative Example 5b. Table 5 shows the results of residual potential after exposure for 30 seconds.
[Table 5]
From the results in Table 5, an increase in the residual potential is confirmed by placing an insulating thin film having an opening on the sample table of the turntable. From the size of the opening in the insulating thin film, the potential of the device under test is confirmed. It can be seen that an increase in the residual potential can be suppressed by reducing the area measured by the electrometer for measuring.
[0015]
<Example 6>
Using the same characteristic evaluation apparatus as in FIG. 1, a photoconductor sample piece (a sample piece having the same material and composition as the Ricoh SP2000 photoconductor) is rotated at high speed (rotation speed: 1000 rpm), and corona charging and exposure are performed. The photoconductor sample piece was deteriorated. (Photoconductor surface potential: -800 V, photoconductor passage current: -5.6 μA while maintaining the photoconductor sample piece for 1 hour) Thereafter, the characteristic evaluation apparatus of FIG. 1 in a high humidity environment (humidity 80%) Was used to measure the electrical characteristics of the photoreceptor sample pieces.
At that time, an insulating thin film (thickness: 10 μm, material: Teflon (registered trademark), size: 55 × 55 mm, opening size: 43 × 43 mm) having an opening was placed on the sample table of the turntable. A sample was placed on top (see FIG. 5). Further, the potential measurement was performed using a NESA capacitance type electrometer in which one side of quartz glass was nesa-coated in a mesh shape, and the size of the mesh coating portion was measured using a 35 mm × 35 mm object. The mesh coating part exists at a position where it can fit in the opening of the insulating thin film, and the gate time for measuring the potential is measured with a structure in which the area measured by the electrometer is at the position within the sample measurement size. This case is referred to as Example 6.
[0016]
Also, when measuring a deteriorated photoconductor, nothing is placed on the sample table of the turntable in a normal humidity environment (humidity 55%), and the potential measurement is a NESA capacitance type in which one side of quartz glass is nesa-coated in a mesh shape. Using an electrometer, the mesh coating part has a size of 50 mm × 50 mm, and the gate time for measuring the potential is from the time when the area measured by the electrometer is part of the photoconductor sample piece. A case in which the structure is such that the measurement is performed until the photosensitive sample piece is removed from the measurable position is referred to as Comparative Example 6 . Table 6 shows the result of the residual potential.
[Table 6]
From the results in Table 6, place an insulating thin film with an opening on the sample table of the turntable, place the sample on it, make the area measured by the electrometer smaller than the opening size of the insulating thin film, It can be seen that by measuring the gate time for measuring the potential at such a time that the area measured by the electrometer is at a position within the opening size of the insulating thin film, an increase in the residual potential can be prevented and accurate measurement can be performed.
[0017]
【The invention's effect】
As described above, according to the first aspect, the turntable having an opening capable of setting the electrophotographic photosensitive member sample piece, the means for rotating the turntable at high speed, and the charging and exposing means for electrophotography. A test apparatus for evaluating characteristics of a photoconductor, wherein a sample installation surface of a turntable and / or a sample window frame portion perpendicular to the installation surface is covered with an insulating film. The body testing device can prevent the charge of the electrophotographic photoreceptor from leaking to the sample window frame during measurement.
3. The electrophotographic photoreceptor testing apparatus according to claim 2, wherein the electrophotographic photoreceptor testing apparatus according to claim 1 is measured by an electrometer that measures the potential of the test object from the size of the sample window frame portion of the turntable. Electrostatic photoconductor testing apparatus characterized in that the area is reduced to an area that fits within the sample measurement size during turntable rotation, and potential measurement other than the test object can be suppressed.
4. The electrophotographic photoreceptor testing device according to claim 3, wherein the electrometric photoconductor testing apparatus according to claim 2 has a gate time for measuring the potential of the photoreceptor sample piece at a position within the sample measurement size. With the electrophotographic photoreceptor testing device characterized in that it exists, it is possible to measure the potential of only the device under test without measuring the potential of unnecessary portions.
5. The electrophotographic photoreceptor testing apparatus according to claim 4, wherein the electrophotographic photoreceptor includes a turntable having an opening in which an electrophotographic photoreceptor sample piece can be set, means for rotating the turntable at high speed, and charging and exposure means. In the photoconductor characteristic value evaluation test equipment, an insulating thin film with an opening smaller than the size of the sample window frame part of the turntable is installed on the sample table of the turntable, and a photoconductor sample piece is installed thereon. Thus, the electrophotographic photoconductor testing apparatus characterized in that the photoconductor characteristic value is measured can prevent the charge of the electrophotographic photoconductor from leaking to the sample window frame portion during the measurement.
6. The electrophotographic photoconductor testing device according to claim 5, wherein the electrophotographic photoconductor testing device according to claim 4 has an area measured by an electrometer that measures the potential of the device under test from the opening size of the insulating thin film. Electrostatic photoconductor testing apparatus characterized by having a small area and the area within the size of the opening of the insulating thin film during turntable rotation can suppress potential measurement other than the test object.
7. The electrophotographic photosensitive member testing apparatus according to claim 6, wherein the electrometric photosensitive member testing apparatus according to claim 5 has a gate time for measuring a potential of the photosensitive member sample piece, the electrometer measuring the opening size of the insulating thin film. With the electrophotographic photoreceptor testing apparatus characterized in that it is within the time existing in the position, it is possible to measure the potential of only the test object without measuring the potential of the unnecessary portion.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a conventional electrophotographic photosensitive member sample characteristic evaluation apparatus used in the present invention.
FIG. 2 is an explanatory view showing the results of surface potential measurement by the evaluation apparatus sample table cover of the present invention.
FIG. 3 is an explanatory diagram showing a charging current measurement result by a sample table covering of the evaluation apparatus of the present invention.
FIG. 4 is an explanatory view showing sample base window frame partial coating coating of the evaluation apparatus of the present invention.
FIG. 5 is an explanatory view showing a sample base opening film coating of the evaluation apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Turntable, 2 sample piece holding plate, 3 opening part, 4 corona charger, 5 surface potential meter electrode part and exposure apparatus, 6 current measurement / smoothing circuit, etc., 7 surface potential meter: amplifier circuit, etc., 8 Interface (A / D conversion), 9 controller

Claims

An electron which comprises a turntable having an opening capable of setting an electrophotographic photosensitive member sample piece and a rotation driving means for rotating the turntable at a high speed, and which evaluates the characteristics of the electrophotographic photosensitive member by charging and exposing means. in photoconductor test apparatus, the turntable sample installation surface and the mounting surface sample window frame portion electrophotographic photoreceptor test apparatus characterized by being covered by an insulating film is perpendicular to the .

2. The electrophotographic photosensitive member testing apparatus according to claim 1, wherein a measurement area by an electrometer that measures the potential of a test object is made smaller than a size of a sample window frame portion of the turntable, and the measurement is performed during rotation of the turntable. An electrophotographic photoreceptor testing apparatus, characterized in that the area falls within the sample measurement size.

3. The electrophotographic photoconductor testing apparatus according to claim 2, wherein the gate time for measuring the potential of the photoconductor sample piece is within the time during which the electrometer is located within the sample measurement size. Photoconductor testing device.

In an apparatus for evaluating characteristic values of an electrophotographic photoreceptor having a turntable having an opening in which an electrophotographic photoreceptor sample piece can be set, a rotation driving means for rotating the turntable at high speed, and a charging and exposure means, Install an insulating thin film with an opening smaller than the size of the sample window frame of the turntable on the table sample table, and place a photoconductor sample piece on it to measure the photoconductor characteristics. An electrophotographic photoreceptor testing apparatus characterized by the above.

5. The electrophotographic photosensitive member testing apparatus according to claim 4, wherein the area measured by an electrometer for measuring the potential of the device under test is made smaller than the opening size of the insulating thin film, and the measurement area is reduced during rotation of the turntable. An electrophotographic photoreceptor testing apparatus, which fits within an opening size of an insulating thin film.

6. The electrophotographic photoconductor testing device according to claim 5, wherein the gate time for measuring the potential of the photoconductor sample piece is within the time in which the electrometer exists at a position within the opening size of the insulating thin film. An electrophotographic photoreceptor testing apparatus.