JPH08220935A - Method for measuring film thickness of image carrier and image forming device - Google Patents
Method for measuring film thickness of image carrier and image forming deviceInfo
- Publication number
- JPH08220935A JPH08220935A JP7055006A JP5500695A JPH08220935A JP H08220935 A JPH08220935 A JP H08220935A JP 7055006 A JP7055006 A JP 7055006A JP 5500695 A JP5500695 A JP 5500695A JP H08220935 A JPH08220935 A JP H08220935A
- Authority
- JP
- Japan
- Prior art keywords
- image carrier
- image
- image forming
- forming apparatus
- film thickness
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Discharging, Photosensitive Material Shape In Electrophotography (AREA)
- Cleaning In Electrography (AREA)
- Electrophotography Configuration And Component (AREA)
- Control Or Security For Electrophotography (AREA)
- Length Measuring Devices With Unspecified Measuring Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電子写真感光体・静電
記録誘電体等の像担持体の膜厚測定方法、及び該像担持
体に作像プロセスを適用して画像形成を実行させ、像担
持体は繰り返して作像に供する、複写機・プリンター・
ファクシミリ・画像表示装置（ディスプレー装置）等の
画像形成装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the film thickness of an image carrier such as an electrophotographic photosensitive member and an electrostatic recording dielectric, and an image forming process applied to the image carrier to form an image. , The image carrier is repeatedly used for image formation, copiers, printers,
The present invention relates to an image forming apparatus such as a facsimile and an image display device (display device).
【０００２】[0002]
【従来の技術】例えば、電子写真方式（ｅｘ．カールソ
ンプロセス）のプリンタ・複写機等の画像形成装置は、
像担持体として回転ドラム型を一般的とする電子写真感
光体を用い、これに公知の帯電・露光・現像の作像プロ
セスを適用して目的の画像情報に対応したトナー画像を
形成担持させ、そのトナー画像を転写手段で転写材に転
写させ、その転写トナー画像を定着手段にて転写材に永
久固着像として定着させ、該転写材を画像形成物（プリ
ント・コピー）として出力させる。また転写材に対する
トナー画像転写後の感光体はクリーニング手段により表
面から転写残りトナー等が除去されて清掃され、繰り返
して作像に使用される。2. Description of the Related Art For example, an image forming apparatus such as an electrophotographic printer (ex. Carlson process) is used.
An electrophotographic photosensitive member, which is generally a rotating drum type, is used as an image carrier, and a known image forming process of charging, exposing, and developing is applied to form and carry a toner image corresponding to intended image information. The toner image is transferred onto the transfer material by the transfer means, the transferred toner image is fixed onto the transfer material as a permanently fixed image by the fixing means, and the transfer material is output as an image-formed product (print / copy). Further, after the transfer of the toner image to the transfer material, the photosensitive member is cleaned by removing the transfer residual toner and the like from the surface by the cleaning means, and is repeatedly used for image formation.
【０００３】近年、この種の画像形成装置は、パーソナ
ルユーザー向けの小型機種が広く普及している。このよ
うな機種においては、トナー、像担持体としての感光体
等の消耗品の交換や廃トナーの処理等がユーザーが行え
るように、取り扱いやメンテナンスが容易なプロセスカ
ートリッジを用いるものが広く実用化されている。In recent years, small-sized image forming apparatuses of this type have been widely used for personal users. In such models, those that use process cartridges that are easy to handle and maintain are widely put into practical use so that users can replace consumable items such as toner and photoconductors as image carriers, and process waste toner. Has been done.
【０００４】プロセスカートリッジとは、帯電手段、現
像手段またはクリーニング手段と像担持体とを一体的に
カートリッジ化し、このカートリッジを画像形成装置本
体に着脱可能とするものである。及び帯電手段、現像手
段、クリーニング手段の少なくとも一つと像担持体とを
一体的にカートリッジ化して画像形成装置本体に着脱可
能とするものである。更に、少なくとも現像手段と像担
持体とを一体的にカートリッジ化して画像形成装置本体
に着脱可能とするものである。The process cartridge is a cartridge in which the charging means, the developing means or the cleaning means and the image carrier are integrally formed, and the cartridge can be attached to and detached from the main body of the image forming apparatus. Also, at least one of the charging means, the developing means, and the cleaning means and the image carrier are integrally made into a cartridge so that it can be attached to and detached from the main body of the image forming apparatus. Further, at least the developing means and the image carrier are integrally made into a cartridge so that it can be attached to and detached from the main body of the image forming apparatus.
【０００５】より具体的には、プロセスカートリッジ内
には主に、トナー収容部を含む現像装置、像担持体であ
る感光ドラム、感光ドラムを帯電するための帯電器、廃
トナー収容部を含むクリーナー等が含まれており、ユー
ザーが定期的に新しいカートリッジに交換することによ
り、従来サービスマンが行っていたメンテナンスをユー
ザーが行うことが可能となった。More specifically, the process cartridge mainly includes a developing device including a toner accommodating portion, a photosensitive drum as an image carrier, a charger for charging the photosensitive drum, and a cleaner including a waste toner accommodating portion. Etc. are included, and it becomes possible for the user to perform the maintenance that the service person used to do, by periodically replacing the cartridge with a new cartridge.
【０００６】一方、プロセスカートリッジの使用に伴い
画像形成装置には幾つかの機能を設けなければならな
い。On the other hand, the use of the process cartridge requires the image forming apparatus to have some functions.
【０００７】第１に、プロセスカートリッジは装置本体
への収納時には外から見えないので、ユーザーはカート
リッジが装置本体に装着されているか否かを確認しずら
い。このため、カートリッジ未装着の状態ではプリント
が行えないように、カートリッジの有無を装置本体で検
知する手段が必要になる。その検知手段としては、機械
式、或は光学式センサーを用いるものが一般的である。First, since the process cartridge is not visible from the outside when it is stored in the apparatus body, it is difficult for the user to confirm whether or not the cartridge is mounted in the apparatus body. Therefore, a means for detecting the presence or absence of a cartridge in the apparatus body is required so that printing cannot be performed in the state where the cartridge is not mounted. As the detection means, a mechanical or optical sensor is generally used.
【０００８】第２に、プロセスカートリッジは消耗品で
あるため、何らかの手段でユーザーにカートリッジ寿命
を知らせる機能を設ける必要があり、多くの画像形成装
置に於いては、トナーの残量検知機能を設け、トナー残
量によりカートリッジ寿命をユーザーに知らせている。Secondly, since the process cartridge is a consumable item, it is necessary to provide a function of informing the user of the cartridge life by some means, and many image forming apparatuses are provided with a toner remaining amount detecting function. The cartridge life is informed to the user by the remaining amount of toner.
【０００９】上記のカートリッジ有無検知とトナー残量
検知の２つの検知手段を別々に設けることは装置の複雑
化につながり、装置の低価格化・小型化への妨げになる
ので、カートリッジ有無検知とトナー残量検知に同一の
光学式センサーを用いる事によって装置を簡素化する方
式が実用化されている。The provision of the two detecting means for detecting the presence / absence of the cartridge and the detection of the remaining toner amount separately leads to the complication of the apparatus and hinders the cost reduction and downsizing of the apparatus. A method of simplifying the apparatus by using the same optical sensor for detecting the remaining amount of toner has been put into practical use.
【００１０】しかし、プロセスカートリッジには前述の
一体型タイプのほかに、現像カートリッジ（トナー容器
を含む）と感光ドラムカートリッジが別体のタイプもあ
り、特に近年実用化されているカラー画像形成装置では
殆ど別体カートリッジが使用されている。この場合、各
々のカートリッジ毎に有無検知と、寿命検知を行なわな
ければならない。However, in addition to the above-mentioned integrated type, the process cartridge also includes a type in which a developing cartridge (including a toner container) and a photosensitive drum cartridge are separately provided, and particularly in a color image forming apparatus which has been put into practical use in recent years. Almost separate cartridges are used. In this case, presence / absence detection and life detection must be performed for each cartridge.
【００１１】ここで、像担持体としての感光体の寿命に
ついて説明する。像担持体としての感光体は繰り返し使
用で次第にすり減っていく。感光体は前述のように転写
工程後にクリーニング手段で転写残りトナー等が除去さ
れて清掃され繰り返して作像に使用されるけれども、繰
り返して使用されるうちには、その表面が、融着トナ
ー、転写材の成分、帯電時の放電生成物などの強固な汚
れで次第に汚染されていく。感光体表面が汚染されてく
ると、感光体の所定の表面抵抗が下がって静電潜像が乱
されたり、融着トナー等のために、出力画像が損なわれ
るようになる。そこで、現像剤に研磨剤を含ませたり、
クリーニング手段のクリーニングブレード等で感光体表
面を積極的に研磨する構成にして、感光体の繰り返し使
用過程で感光体表面を少しずつ削らせることで、感光体
表面を常に新しい表面状態に保たせるという方法が従来
より実施されている。これによれば、感光体表面は常に
リフレッシュされるので、初期と同等の表面状態が維持
され、従って良好な画像の出力が維持される。Here, the life of the photosensitive member as the image bearing member will be described. The photoconductor as an image carrier gradually wears out after repeated use. As described above, the photoconductor is used for image formation by repeatedly removing the transfer residual toner and the like by the cleaning means after the transfer step, and repeatedly used for image formation. It is gradually contaminated with strong stains such as components of the transfer material and discharge products at the time of charging. When the surface of the photoconductor is contaminated, the predetermined surface resistance of the photoconductor is lowered to disturb the electrostatic latent image, or the fused toner or the like causes the output image to be damaged. Therefore, if you include an abrasive in the developer,
It is said that the surface of the photoconductor is always kept in a new state by gradually abrading the surface of the photoconductor in the process of repeatedly using the photoconductor by positively polishing the surface of the photoconductor with a cleaning blade of a cleaning means. The method is conventionally practiced. According to this, since the surface of the photoconductor is constantly refreshed, the surface state equivalent to that at the initial stage is maintained, and therefore, good image output is maintained.
【００１２】しかしながら、感光体表面が繰り返し使用
に伴い少しずつ削られて感光体（感光層）膜厚が次第に
薄くなっていくことで、感光体としての寿命が生じてし
まうことになる。However, the surface of the photoconductor is gradually scraped as it is repeatedly used, and the film thickness of the photoconductor (photosensitive layer) is gradually reduced, so that the life of the photoconductor is extended.
【００１３】感光体は、暗部（光を当てない部分）で
は、コンデンサーとして働くので、暗所で感光体表面に
電荷を与えるとそれが保持され、表面電位として現れ
る。電子写真方式の場合、この表面電位を一定に保つた
めに、感光体の膜厚に応じて与える電荷量を変えてい
る。The photoconductor functions as a capacitor in a dark portion (a portion not exposed to light). Therefore, when a charge is applied to the surface of the photoconductor in a dark place, it is held and appears as a surface potential. In the case of the electrophotographic method, in order to keep the surface potential constant, the amount of electric charge applied is changed according to the film thickness of the photoconductor.
【００１４】つまり、感光体の膜厚が変わるとコンデン
サーとしての容量が変わる。すなわち、膜厚が厚いと容
量が減り、薄いと容量が増えるので、電位を一定にする
ために電荷量を変えるわけである。膜厚が薄くなっても
与える電荷量を増やせば一定の表面電位を保つことが出
来、良好な画像を維持することが出来る。That is, when the film thickness of the photosensitive member changes, the capacity of the capacitor changes. That is, since the capacitance decreases when the film thickness is thick and the capacitance increases when the film thickness is thin, the amount of charge is changed to keep the potential constant. Even if the film thickness becomes thin, a constant surface potential can be maintained by increasing the amount of electric charges applied, and a good image can be maintained.
【００１５】しかし、あまり薄くなると、帯電器で与え
られる電荷量には限度があるので、電位低下を招いた
り、また、感光体の膜にも多少の欠陥があるので、局所
的に電荷が逃げてしまい著しく画像品位を損ねてしまう
結果となる。However, if the thickness is too thin, the amount of charge provided by the charger is limited, which causes a decrease in potential, and the film of the photoconductor also has some defects, so that the charge locally escapes. As a result, the image quality is remarkably impaired.
【００１６】したがって、良好な画像を維持するために
は最低限必要な感光体膜厚がある。例えば後述する実施
例で用いたＯＰＣ感光体では感光層（最上層の電荷輸送
層；ＣＴ層、Carrier Transfer Layer）の初期厚さは約
２５μｍであるが、一般に良好な画像を得るためには感
光層の厚みが１５μｍ以上必要であり、これ以上の削れ
を生じた場合には安定した画像を保証することができ
ず、感光ドラムの寿命を越えたと考えることができる。Therefore, in order to maintain a good image, there is a minimum photosensitive member film thickness. For example, in the OPC photoreceptor used in the examples described below, the initial thickness of the photosensitive layer (the uppermost charge transport layer; CT layer, Carrier Transfer Layer) is about 25 μm. The thickness of the layer is required to be 15 μm or more, and when the abrasion is more than this, a stable image cannot be guaranteed, and it can be considered that the life of the photosensitive drum has been exceeded.
【００１７】そこで、感光体膜厚を検知することで像担
持体としての感光体あるいは該感光体を含むプロセスカ
ートリッジの寿命を判断させることができる。Therefore, by detecting the thickness of the photoconductor, it is possible to determine the life of the photoconductor as an image bearing member or the process cartridge including the photoconductor.
【００１８】感光体の膜厚を検知する方法は、感光体の
前述のコンデンサーとしての特性を利用した方法などが
提案されている（例えば特開平５−５３４８８号公
報）。これは、感光体を帯電した状態から、電荷を除去
したとき（あるいは、電荷を除去した状態から帯電した
とき）に流れる電流を検出し、そこからコンデンサーと
しての容量を計測して感光体の膜厚を算出する方法であ
る。As a method for detecting the film thickness of the photoconductor, a method utilizing the above-mentioned characteristics of the photoconductor as a capacitor has been proposed (for example, JP-A-5-53488). This is to detect the current that flows when the charge is removed from the charged state of the photoconductor (or when charged from the state where the charge is removed), and measure the capacity as a capacitor from there to measure the film of the photoconductor. This is a method of calculating the thickness.
【００１９】感光体表面電位を０→Ｖd に上昇、或はＶ
d →０に下降させるときに、感光体に流れるＤＣ電流Ｉ
DCは、感光体の膜厚をｄ、比誘電率をε、真空中の誘電
率をε0 、１次帯電器の有効帯電幅をＬ、プロセススピ
ードをvpとすると、以下の関係式で表される。The surface potential of the photoconductor is increased from 0 to Vd, or V
DC current I flowing through the photoconductor when d → 0
DC is expressed by the following relational expression, where d is the film thickness of the photoconductor, ε is the relative permittivity, ε0 is the permittivity in vacuum, L is the effective charging width of the primary charger, and vp is the process speed. It
【００２０】 ｜ＩDC｜＝ε・ε0 ・Ｌ・vp・Ｖd ／ｄ ・・・・・・ ε、ε0 、Ｌ、vp、Ｖd は定数とみなすことができるの
で、ＤＣ電流ＩDCは感光体の膜厚に反比例することがわ
かる。従って、ＤＣ電流ＩDCを測定することにより感光
体の膜厚を検知することができる（特開平５−２２３５
１３号公報）。| I DC | = ε · ε 0 · L · vp · Vd / d ··· ε, ε 0, L, vp, Vd can be regarded as constants, so the DC current I DC is It can be seen that it is inversely proportional to the film thickness of. Therefore, the film thickness of the photoconductor can be detected by measuring the DC current I DC (Japanese Patent Laid-Open No. 5-2235).
13 publication).
【００２１】[0021]
【発明が解決しようとする課題】上述の電流測定による
像担持体としての感光体の膜厚検知は、実際には非常に
微弱な電流を測定するため高精度の電流検知が必要であ
る。本発明はその検知精度の向上を図ることを目的とす
る。In order to detect the film thickness of the photoconductor as an image bearing member by the above current measurement, a very weak current is actually measured, so that highly accurate current detection is required. An object of the present invention is to improve the detection accuracy.
【００２２】また本発明は、画像形成装置本体に対する
像担持体あるいは像担持体を含むプロセスカートリッジ
の装着有無検知と、像担持体あるいは像担持体を含むプ
ロセスカートリッジの寿命検知の両検知を共通の手段構
成で行なわせて、装置の簡素化・低価格化・小型化を図
ることを目的とする。Further, the present invention has a common function of detecting whether or not the image carrier or the process cartridge including the image carrier is attached to the main body of the image forming apparatus and detecting the life of the image carrier or the process cartridge including the image carrier. The purpose is to achieve the simplification, cost reduction, and size reduction of the device by using the means configuration.
【００２３】[0023]
【課題を解決するための手段】本発明は下記を特徴とす
る、像担持体の膜厚測定方法、及び画像形成装置であ
る。The present invention provides a method for measuring the film thickness of an image carrier and an image forming apparatus characterized by the following.
【００２４】（１）像担持体に流れる電流の測定による
像担持体の膜厚測定時、像担持体に当接している部材の
少なくとも１つを像担持体から離間することを特徴とす
る像担持体の膜厚測定方法。(1) An image characterized by separating at least one of the members in contact with the image carrier from the image carrier when the film thickness of the image carrier is measured by measuring the current flowing through the image carrier. A method for measuring the thickness of a carrier.
【００２５】（２）像担持体に流れる電流の測定による
像担持体の膜厚測定時、像担持体に当接あるいは近接し
ている部材を像担持体表面と同電位の電位ないし０Ｖに
することを特徴とする像担持体の膜厚測定方法。(2) When the film thickness of the image carrier is measured by measuring the current flowing through the image carrier, the member which is in contact with or close to the image carrier is set to the same potential as the surface of the image carrier or 0V. A method for measuring a film thickness of an image carrier, comprising:
【００２６】（３）像担持体が電子写真感光体あるいは
静電記録誘電体であることを特徴とする（１）または
（２）に記載の像担持体の膜厚測定方法。(3) The method for measuring the film thickness of an image carrier according to (1) or (2), wherein the image carrier is an electrophotographic photosensitive member or an electrostatic recording dielectric.
【００２７】（４）像担持体に作像プロセスを適用して
画像形成を実行させ、像担持体は繰り返して作像に供す
る画像形成装置において、像担持体を流れる電流を測定
する手段と、その測定電流により像担持体あるいは像担
持体を含むプロセスカートリッジの装置本体に対する装
着の有無を判断する手段を有することを特徴とする画像
形成装置。(4) Means for measuring a current flowing through the image carrier in an image forming apparatus in which an image forming process is applied to the image carrier to perform image formation, and the image carrier is repeatedly subjected to image formation. An image forming apparatus comprising means for judging whether or not the image carrier or the process cartridge including the image carrier is mounted on the apparatus body by the measured current.
【００２８】（５）測定電流により像担持体の膜厚を測
定して像担持体あるいは像担持体を含むプロセスカート
リッジの寿命を判断する手段を有することを特徴とする
（４）に記載の画像形成装置。(5) The image according to (4), further comprising means for measuring the film thickness of the image bearing member with a measuring current to determine the life of the image bearing member or the process cartridge including the image bearing member. Forming equipment.
【００２９】（６）像担持体に流れる電流の測定時、像
担持体に当接している部材の少なくとも１つを像担持体
から離間することを特徴とする（４）に記載の画像形成
装置。(6) At the time of measuring the current flowing through the image carrier, at least one of the members in contact with the image carrier is separated from the image carrier, and the image forming apparatus according to (4). .
【００３０】（７）像担持体に流れる電流の測定時、像
担持体に当接あるいは近接している部材を像担持体表面
と同電位の電位ないし０Ｖにすることを特徴とする
（４）に記載の画像形成装置。(7) When measuring the current flowing through the image carrier, a member which is in contact with or close to the image carrier is set to the same potential as the surface of the image carrier or 0 V (4). The image forming apparatus according to item 1.
【００３１】（８）像担持体が電子写真感光体あるいは
静電記録誘電体であることを特徴とする（４）に記載の
画像形成装置。(8) The image forming apparatus according to (4), wherein the image carrier is an electrophotographic photosensitive member or an electrostatic recording dielectric.
【００３２】（９）プロセスカートリッジは、帯電手
段、現像手段またはクリーニング手段と像担持体とを一
体的にカートリッジ化し、このカートリッジを画像形成
装置本体に着脱可能とするものであることを特徴とする
（４）に記載の画像形成装置。(9) The process cartridge is characterized in that the charging means, the developing means or the cleaning means and the image carrier are integrated into a cartridge, and the cartridge can be attached to and detached from the main body of the image forming apparatus. The image forming apparatus according to (4).
【００３３】（１０）プロセスカートリッジは、帯電手
段、現像手段、クリーニング手段の少なくとも一つと像
担持体とを一体的にカートリッジ化して画像形成装置本
体に着脱可能とするものであることを特徴とする（４）
に記載の画像形成装置。(10) The process cartridge is characterized in that at least one of the charging means, the developing means, and the cleaning means and the image carrier are integrally made into a cartridge so as to be attachable to and detachable from the main body of the image forming apparatus. (4)
The image forming apparatus according to item 1.
【００３４】（１１）プロセスカートリッジは、少なく
とも現像手段と像担持体とを一体的にカートリッジ化し
て画像形成装置本体に着脱可能とするものであることを
特徴とする（４）に記載の画像形成装置。(11) The image forming apparatus according to (4), characterized in that at least the developing means and the image carrier are integrated into a cartridge so that the process cartridge can be attached to and detached from the main body of the image forming apparatus. apparatus.
【００３５】[0035]
ａ）像担持体に流れる電流の測定による像担持体の膜厚
測定は、非常に微弱な電流を測定するため、像担持体に
導電部材や他の電荷を帯びた部材、例えば現像部材・転
写部材などが当接しているとき、該部材と像担持体の間
に電流が生じてしまい、正確な電流検知・像担持体膜厚
測定が困難である。像担持体に流れる電流の測定による
像担持体の膜厚測定の際は、像担持体に当接している上
記のような部材を像担持体から離間させることで、もし
くは像担持体に当接あるいは近接している部材を像担持
体表面電位と同電位の電位ないし０Ｖにすることで、該
部材と像担持体の間に電流が生じることを防止できるの
で、正確な電流検知ができ、像担持体の膜厚検知精度が
向上する。a) Since the film thickness of the image carrier is measured by measuring the current flowing through the image carrier, a very weak current is measured. Therefore, a conductive member or other charged member such as a developing member or a transfer member is attached to the image carrier. When a member or the like is in contact, an electric current is generated between the member and the image carrier, which makes it difficult to accurately detect the current and measure the thickness of the image carrier. When measuring the film thickness of the image bearing member by measuring the current flowing through the image bearing member, the above-mentioned members that are in contact with the image bearing member are separated from the image bearing member or contact the image bearing member. Alternatively, by setting a potential close to the surface potential of the image bearing member or 0 V to a member in proximity to it, it is possible to prevent a current from being generated between the member and the image bearing member, so that accurate current detection can be performed. The accuracy of detecting the film thickness of the carrier is improved.
【００３６】ｂ）画像形成装置に、像担持体に流れる電
流を測定する手段を具備させることで、その測定電流に
基づいて、像担持体の膜厚を測定して像担持体あるいは
像担持体を含むプロセスカートリッジの寿命検知を行な
うことができ、また像担持体あるいは像担持体を含むプ
ロセスカートリッジが装着されていなければ検知電流が
０となることに着目してこれに基づいて装着なしの判断
を行なわせることができる。この際、像担持体に当接し
ている部材を像担持体から離間させることで、もしくは
像担持体に当接あるいは近接している部材を像担持体表
面電位と同電位の電位ないし０Ｖにすることで、該部材
と像担持体の間に電流が生じることを防止できるので、
正確な電流検知ができ、像担持体の膜厚検知精度が向上
する。B) The image forming apparatus is provided with means for measuring the current flowing through the image carrier, and the film thickness of the image carrier is measured based on the measured current to measure the thickness of the image carrier or the image carrier. Based on this, it is possible to detect the life of the process cartridge including the process cartridge, and if the image carrier or the process cartridge including the image carrier is not installed, the detection current will be 0. Can be done. At this time, the member in contact with the image carrier is separated from the image carrier, or the member in contact with or close to the image carrier is set to the same potential as the surface potential of the image carrier or 0 V. By doing so, it is possible to prevent an electric current from being generated between the member and the image carrier,
The current can be accurately detected, and the film thickness detection accuracy of the image carrier is improved.
【００３７】即ち、像担持体に流れる電流を測定する方
式により、像担持体やプロセスカートリッジの寿命検知
と有無検知との両方を兼用手段で行なうことができて、
従来のように像担持体やプロセスカートリッジの有無検
知は機械的センサーによって行なう場合のような装置の
複雑化を回避でき、装置の簡素化、・低価格化・小型化
が可能となる。That is, by the method of measuring the current flowing through the image carrier, both the life detection and the presence / absence detection of the image carrier or the process cartridge can be performed by the combined means.
The detection of the presence or absence of the image carrier or the process cartridge as in the conventional case can avoid the complication of the device as in the case where a mechanical sensor is used, and the device can be simplified, reduced in cost, and downsized.
【００３８】[0038]
（１）画像形成装置の概略構成 図１は本発明に従う画像形成装置の概略構成図である。
本例の画像形成装置は、転写式電子写真プロセス利用
の、プロセスカートリッジ着脱式（別体カートリッジ
式）、レーザービーム走査型のカラー画像形成装置（プ
リンター）である。(1) Schematic Configuration of Image Forming Apparatus FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the present invention.
The image forming apparatus of this example is a process cartridge detachable type (separate cartridge type) laser beam scanning type color image forming apparatus (printer) that uses a transfer type electrophotographic process.
【００３９】１は像担持体としての感光ドラムである。
不図示の駆動手段によって矢示の反時計方向に所定のプ
ロセススピード（周速度）をもって回転駆動される。本
例の感光ドラム１は、導電性基体としての直径４０ｍｍ
のアルミニウムドラム１ａ（図３）の外周面に負帯電の
ＯＰＣ感光体層（有機光導電体層）１ｂを塗工したもの
である。該感光体層１ｂは電荷発生層の上に最上層とし
て厚さｄ＝２５μｍの電荷輸送層（ＣＴ層）を配したも
のである。本実施例ではそのＣＴ層のバインダーとして
ポリカーボネート樹脂を用いている。Reference numeral 1 is a photosensitive drum as an image bearing member.
It is rotationally driven in the counterclockwise direction indicated by an arrow at a predetermined process speed (peripheral speed) by a driving means (not shown). The photosensitive drum 1 of this example has a diameter of 40 mm as a conductive substrate.
The aluminum drum 1a of FIG. 3 (FIG. 3) is coated with a negatively charged OPC photosensitive layer (organic photoconductive layer) 1b. The photoreceptor layer 1b has a charge transport layer (CT layer) having a thickness d = 25 μm as the uppermost layer on the charge generation layer. In this embodiment, a polycarbonate resin is used as the binder for the CT layer.
【００４０】２は帯電手段であり、本例はローラ帯電帯
電器（接触帯電ローラ）である。この帯電ローラ２は芯
金の両端部を回転自由に軸受させて所定の押圧力をもっ
て感光ドラム１の外面に圧接させてあり、本例では感光
ドラム１の回転に従動して回転する。帯電ローラ２には
バイアス電源２０（図５）より、−７００Ｖの直流電圧
に、交流周波数１０００Ｈｚでピーク間電圧ＶPP＝２０
００Ｖの交流電圧が重畳された振動電圧が印加されるこ
とで、回転感光ドラム１の感光体層１ｂの外面がほぼ−
７００Ｖに均一に一次帯電処理される。A charging means 2 is a roller charging charger (contact charging roller) in this example. The charging roller 2 has both ends of a core bar rotatably supported and is pressed against the outer surface of the photosensitive drum 1 with a predetermined pressing force. In this example, the charging roller 2 is rotated by the rotation of the photosensitive drum 1. For the charging roller 2, a bias power source 20 (FIG. 5) applies a DC voltage of −700 V, an AC frequency of 1000 Hz, and a peak-to-peak voltage V PP = 20.
By applying an oscillating voltage on which an AC voltage of 00 V is superposed, the outer surface of the photoconductor layer 1b of the rotary photosensitive drum 1 is almost −.
Primary charging treatment is uniformly performed to 700V.
【００４１】４は画像情報露光手段としてのレーザース
キャナである。このレーザースキャナ４は、不図示の画
像読取り装置・コンピュータ等のホスト装置から入力さ
れる目的の画像情報の時系列電気デジタル画素信号に対
応して変調されたレーザー光９を出力して、回転感光ド
ラム１の帯電処理面を走査露光し、感光ドラム１面の走
査露光部分の電位が略−１００Ｖに減衰することで、感
光体層１ｂ面に露光パターンに対応した静電潜像が形成
される。Reference numeral 4 is a laser scanner as an image information exposing means. The laser scanner 4 outputs a laser beam 9 modulated corresponding to a time-series electric digital pixel signal of target image information input from a host device such as an image reading device or a computer (not shown), and a rotary exposure light. The charged surface of the drum 1 is scanned and exposed, and the potential of the scan-exposed portion of the surface of the photosensitive drum 1 is attenuated to approximately −100 V, whereby an electrostatic latent image corresponding to the exposure pattern is formed on the surface of the photosensitive layer 1b. .
【００４２】カラー画像形成の場合は、目的のカラー画
像の例えばイエロー成分像に対応した走査露光・潜像形
成がなされ、その潜像が回転切換え式現像装置３のイエ
ロートナー現像器３ａによりイエロートナーで反転現像
される。そのイエロートナー像が回転転写ドラム５に巻
き付け保持させた転写材面に転写される。転写後の感光
ドラム１面はファーブラシ・ブレード手段等のクリーニ
ング装置７で清掃され、帯電ローラ２で再び帯電処理さ
れる。In the case of forming a color image, scanning exposure / latent image formation corresponding to, for example, a yellow component image of a target color image is performed, and the latent image is formed by the yellow toner developing device 3a of the rotation switching type developing device 3 into yellow toner. Reverse development is performed. The yellow toner image is transferred onto the surface of the transfer material which is wound around and held on the rotary transfer drum 5. The surface of the photosensitive drum 1 after the transfer is cleaned by a cleaning device 7 such as a fur brush / blade means, and charged again by the charging roller 2.
【００４３】このような作像サイクルが、引続いて目的
のカラー画像の例えばマゼンタ成分像・シアン成分像・
黒成分像について順次に実行され、そのサイクル毎に現
像装置３の現像器がマゼンタトナー現像器３ｂ・シアン
トナー現像器３ｃ・黒トナー現像器３ｄと順に切り換わ
り、転写ドラム５に巻き付け保持されている同一の転写
材面に対して最初の転写済みイエロートナー像に次い
で、マゼンタトナー像、シアントナー像、黒トナー像が
順次に位置合せされて転写されることで、転写材面に目
的のカラー画像に対応したカラートナー画像が重畳転写
で合成形成される。Such an image formation cycle is followed by the subsequent formation of the desired color image, for example, a magenta component image, a cyan component image,
The black component image is sequentially executed, and the developing device of the developing device 3 is sequentially switched to the magenta toner developing device 3b, the cyan toner developing device 3c, and the black toner developing device 3d for each cycle, and is wound around the transfer drum 5 and held. After the first transferred yellow toner image is transferred to the same transfer material surface, the magenta toner image, cyan toner image, and black toner image are sequentially aligned and transferred, so that the target color image is transferred to the transfer material surface. A color toner image corresponding to the image is synthetically formed by superimposing transfer.
【００４４】最終の黒トナー像の転写を受けた転写材は
転写ドラム５の面から分離爪１４によって分離され、加
熱・加圧定着装置６へ搬送導入されてトナー像の溶融固
着を受け、カラープリントとして出力される。The transfer material which has received the final transfer of the black toner image is separated from the surface of the transfer drum 5 by the separation claws 14 and is conveyed to the heating / pressurizing fixing device 6 where it is melted and fixed to the toner image to form a color image. It is output as a print.
【００４５】現像装置３は回転体８に対して上記４つの
トナー現像器３ａ〜３ｄを配置保持させてあり、回転体
８が９０°回転駆動される毎に感光ドラム１に対する作
用現像器の切り換えがなされる。各現像器３ａ〜３ｄは
現像用開口面（現像ローラ３ｃ部）が感光ドラム面の現
像部位に対向するように姿勢制御される。現像器３ａ〜
３ｄはカートリッジ形態をとっており、各々交換可能に
なっている。In the developing device 3, the four toner developing devices 3a to 3d are arranged and held with respect to the rotating body 8, and every time the rotating body 8 is driven to rotate 90 °, the action developing device for the photosensitive drum 1 is switched. Is done. The attitudes of the developing devices 3a to 3d are controlled so that the developing opening surface (developing roller 3c portion) faces the developing portion of the photosensitive drum surface. Developing device 3a-
3d is in the form of a cartridge and can be replaced.
【００４６】転写ドラム５は、直径１６０ｍｍの金属シ
リンダー５ａに、厚さ２ｍｍの弾性層５ｂを巻き付け、
更に上層には厚さ１００μｍのＰＶＤＦ層５ｃを巻き付
けて構成されており、感光ドラム１に対して転写部位に
て接触もしくは近接しており、矢示の時計方向に感光ド
ラム１と略同じ周速度をもって回転駆動される。The transfer drum 5 comprises a metal cylinder 5a having a diameter of 160 mm and an elastic layer 5b having a thickness of 2 mm, which is wound around the metal cylinder 5a.
Further, a PVDF layer 5c having a thickness of 100 μm is wound around the upper layer, and the PVDF layer 5c is in contact with or close to the photosensitive drum 1 at a transfer portion, and the peripheral speed is substantially the same as that of the photosensitive drum 1 in a clockwise direction indicated by an arrow. Is driven to rotate.
【００４７】所定の給紙タイミングにて給紙カセット１
０内の転写材がピックアップローラ１１により給紙され
てその先端部が転写ドラム５のグリッパー１２によって
保持され、転写ドラム５の回転に伴い該ドラム５の周面
に巻き付くと共に、電圧を印加した吸着ローラ１３によ
って転写ドラム５に静電吸着状態となる。感光ドラム１
上の形成トナー像は、不図示の電源から転写ドラム５に
印加された電圧によって転写ドラム５上の転写材面に転
写部位において順次に転写される。Paper feed cassette 1 at a predetermined paper feed timing
The transfer material in 0 is fed by the pickup roller 11 and the tip thereof is held by the gripper 12 of the transfer drum 5. The transfer material is wound around the peripheral surface of the transfer drum 5 as the transfer drum 5 rotates and a voltage is applied. The attraction roller 13 brings the transfer drum 5 into an electrostatic attraction state. Photosensitive drum 1
The upper formed toner image is sequentially transferred to a transfer material surface on the transfer drum 5 at a transfer portion by a voltage applied to the transfer drum 5 from a power source (not shown).
【００４８】転写ドラム５上に付着したトナーも、必要
に応じて、ファーブラシ、ウェブなどの転写ドラムクリ
ーニング装置１５によって清掃することが好ましい。本
例のプリンターは、感光ドラム１・帯電ローラ２・クリ
ーニング装置７の３つのプロセス機器を一括してプリン
ター本体に対して着脱交換自在のプロセスカートリッジ
Ａとしてある。It is preferable that the toner attached to the transfer drum 5 is also cleaned by a transfer drum cleaning device 15 such as a fur brush or a web, if necessary. The printer of this example is a process cartridge A in which three process devices including a photosensitive drum 1, a charging roller 2, and a cleaning device 7 are collectively attachable to and detachable from the printer body.
【００４９】（２）制御系 本例プリンターにおいては、像担持体としての感光ドラ
ム１の感光体層１ｂに流れる電流を測定する手段を具備
させて、 イ）感光ドラム１の寿命、即ち該感光ドラム１を含むプ
ロセスカートリッジＡの寿命検知、 ロ）該感光ドラム１を含むプロセスカートリッジＡのプ
リンター本体に対する装着有無検知とを行なわせてい
る。(2) Control system In the printer of this example, a means for measuring the current flowing through the photoconductor layer 1b of the photoconductor drum 1 as an image carrier is provided, and a) the life of the photoconductor drum 1, that is, the photoconductor drum The life of the process cartridge A including the drum 1 is detected, and (b) whether the process cartridge A including the photosensitive drum 1 is attached to the printer main body is detected.
【００５０】イ）プロセスカートリッジＡの寿命検知 本例で用いている感光ドラム１のＯＰＣ感光体層１ｂの
最上層である電荷輸送層（ＣＴ層）の初期膜厚は２５μ
ｍであるが、前述したようにこの層はプリンターの繰り
返し使用に伴い少しずつ削られて厚さが薄くなる。良好
な画像を得るためにはＣＴ層の厚みは１５μｍ以上必要
であり、これ以上の削れが生じた場合には感光ドラム１
即ち該感光ドラム１を含むプロセスカートリッジＡは寿
命に達したものと判断させて、その旨を表示するランプ
等の警告手段を作動させ、ユーザーにカートリッジＡの
交換を促す。A) Life detection of process cartridge A The initial thickness of the charge transport layer (CT layer), which is the uppermost layer of the OPC photosensitive layer 1b of the photosensitive drum 1 used in this example, is 25 μm.
However, as described above, this layer is gradually scraped and becomes thin as the printer is repeatedly used. In order to obtain a good image, the thickness of the CT layer needs to be 15 μm or more, and when the abrasion is more than this, the photosensitive drum 1
That is, the process cartridge A including the photosensitive drum 1 is judged to have reached the end of its life, and warning means such as a lamp for indicating that fact is activated to prompt the user to replace the cartridge A.
【００５１】感光体の膜厚検知の基本的技術は、感光体
表面電位をＶd →０下降させるときに感光体に流れるＤ
Ｃ電流ＩDCを図３のように感光ドラム１の導電性基体と
してのアルミニウムドラム１ａと接地間に介在させた検
出回路２１で測定し、ＤＣ電流値ＩDCより膜厚ｄを算出
するものである。The basic technique for detecting the film thickness of the photoconductor is D flowing to the photoconductor when the surface potential of the photoconductor is lowered by Vd → 0.
The C current I DC is measured by the detection circuit 21 interposed between the aluminum drum 1a as the conductive substrate of the photosensitive drum 1 and the ground as shown in FIG. 3, and the film thickness d is calculated from the DC current value I DC. is there.
【００５２】上記のＤＣ電流ＩDCの測定は、プリンター
の前回転期間・紙間・後回転期間などにおいて、図２の
ように、感光ドラム１から該感光ドラム１に対応位置し
ている現像器３（ａ〜ｄ）及び転写ドラム５を離間動作
させて、感光ドラム１から現像器の現像ローラ３ｃ及び
転写ドラム５を非接触状態にして行なわせる。このよう
な離間は現像器及び転写ドラム５の揺動手段（不図示）
を駆動させて自動的に行なわせることができる。このよ
うな離間により感光体を流れる電流の測定、従って感光
体の膜厚検知の精度を向上させることができる。The above DC current I DC is measured by the developing device located from the photosensitive drum 1 to the photosensitive drum 1 as shown in FIG. 2 during the pre-rotation period, the paper interval, the post-rotation period, etc. of the printer. 3 (a to d) and the transfer drum 5 are moved away from each other so that the developing roller 3c of the developing device and the transfer drum 5 are not in contact with each other from the photosensitive drum 1. Such separation is performed by a swinging means (not shown) of the developing device and the transfer drum 5.
Can be automatically driven. By such separation, it is possible to improve the accuracy of measuring the current flowing through the photoconductor, and thus detecting the film thickness of the photoconductor.
【００５３】即ち、現像器の現像ローラ３ｓ及び転写ド
ラム５は不図示の高圧電源より電圧を印加し機能させる
もので、バイアスの非印加時に於いても帯電している可
能性がある。更に現像ローラ３ｓはその表面に電荷を帯
びたトナーＴを常に塗布してある。電流ＩDCの検知時、
これらの電荷を帯びた部材３ｓや５が感光ドラム１に接
していると、該部材３ｓや５と感光ドラム１の間に電流
Ｉs 及びＩt が生じてしまい、正確な電流検知が行なえ
なくなってしまう。本例装置では電流ＩDCを感光ドラム
１の下流側（感光ドラム下層アルミ部分と本体アースと
の間）にて測定するので、この電流ＩS 及びＩt の影響
を特に受けやすい。また、除電前の感光体表面に転写ド
ラム等の部材が当接するとニップ部で電荷の受け渡しが
生じ、感光体の表面電位Ｖd が変化してしまう可能性も
ある。That is, the developing roller 3s and the transfer drum 5 of the developing device are made to function by applying a voltage from a high voltage power source (not shown), and may be charged even when the bias is not applied. Further, the developing roller 3s is always coated with a charged toner T on its surface. When detecting the current I DC ,
When members 3s and 5 tinged these charges is in contact with the photosensitive drum 1, will occur a current I s and I t between the said member 3s and 5 of the photosensitive drum 1, becomes no longer possible accurate current sensing Will end up. In the apparatus of this example, the current IDC is measured on the downstream side of the photosensitive drum 1 (between the photosensitive drum lower layer aluminum portion and the main body ground), and thus the currents I S and I t are particularly susceptible. Further, when a member such as a transfer drum comes into contact with the surface of the photoconductor before the charge removal, charges may be transferred at the nip portion, and the surface potential Vd of the photoconductor may change.
【００５４】以下、感光体に流れるＤＣ電流ＩDCの測定
について説明する。最初に帯電ローラ２に、周波数１０
００Ｈｚ、Ｖｐｐ＝２０００Ｖの交流電圧を印加し感光
ドラム１の表面電位を０Ｖにする。その後、感光体表面
を一定電位Ｖd に帯電する。この帯電は、帯電ローラ２
に 周波数１０００Ｈｚ、Ｖｐｐ２０００Ｖの交流電圧
に−７００Ｖの直流電圧を重畳した電圧を印加した状態
で感光ドラム１を２周以上回転させて行なう。この帯電
により感光ドラム表面はほぼ−７００Ｖに均一に帯電さ
れる。次に帯電ローラ２に周波数１０００Ｈｚ、Ｖｐｐ
＝２０００Ｖの交流電圧を印加した状態で感光ドラムを
１回転させて感光ドラム表面を除電する。この時に感光
ドラム１に流れる直流電流ＩDCと帯電ローラ２への印加
電圧を図４に示す。図中、０→Ｖd の帯電時と、Ｖd →
０の除電時に電流が流れており、両者の電流値は原理的
には等しいはずであるが、帯電時の電流を測定した場
合、感光体上にピンホール等の欠陥が生じていると、こ
の部分に実際に帯電に寄与しないリーク電流が過大に流
れ込み、誤測定を引き起こす。このため直流電流ＩDCの
測定は、除電時に測定する（図中Ｐ部）。The measurement of the DC current I DC flowing through the photosensitive member will be described below. First, charge the roller 2 with a frequency of 10
An AC voltage of 00 Hz and Vpp = 2000V is applied to set the surface potential of the photosensitive drum 1 to 0V. After that, the surface of the photoconductor is charged to a constant potential Vd. This charging is performed by the charging roller 2
Then, the photosensitive drum 1 is rotated two or more times while applying a voltage obtained by superimposing a DC voltage of -700 V on an AC voltage of VHz 2000 V with a frequency of 1000 Hz. By this charging, the surface of the photosensitive drum is uniformly charged to about -700V. Next, a frequency of 1000 Hz, Vpp is applied to the charging roller 2.
= 2000V AC voltage is applied, the photosensitive drum is rotated once to eliminate the charge on the surface of the photosensitive drum. Shows the voltage applied to the DC current I DC and the charging roller 2 that flows at this time the photosensitive drum 1 in FIG. In the figure, when 0 → Vd is charged and Vd →
The current is flowing at the time of static elimination of 0, and the current values of both should be the same in principle. A leak current that does not actually contribute to charging flows into the portion excessively, causing erroneous measurement. Therefore, the DC current I DC is measured at the time of static elimination (P part in the figure).
【００５５】感光体を流れる直流電流ＩDCは前記の関係
式で表され、ＤＣ電流ＩDCを測定することにより感光
体の膜厚を検知できる。本実施例では、ε＝３、ε0 ＝
８．８５×１０-12［Ｆ／ｍ］、Ｌ＝２３０ｍｍ、vp＝
１００［ｍｍ／ｓｅｃ］、Ｖd＝−７００Ｖであるた
め、ｄ＝１５μｍの時、ＩDC＝２７μＡとなる。The direct current I DC flowing through the photoconductor is represented by the above relational expression, and the film thickness of the photoconductor can be detected by measuring the DC current I DC . In this embodiment, ε = 3, ε0 =
8.85 × 10 −12 [F / m], L = 230 mm, vp =
Since 100 [mm / sec] and Vd = -700V, I DC = 27 μA when d = 15 μm.
【００５６】ここで電流ＩDCは図５に示す装置により測
定する。１５μｍの膜厚時の電流量ＩDCは２７μＡであ
るため、図５に示すように電流ＩDCによって１０ｋΩの
抵抗器Ｒ１の両端に発生する電圧が２７μＡに相当する
０．２７Ｖをこえた時に、これに連動した、装置本体面
に配設の不図示の警告灯を点灯する。具体的には、１０
ｋΩの抵抗器Ｒ１の両端の電圧Ｖを基準電圧源２２の基
準電圧Ｖｒｅｆ．＝０．２７Ｖと比較し、コンパレータ
Ｙの出力があった時にＤＣコントローラ２３に感光ドラ
ム寿命すなわちプロセスカートリッジ寿命の信号を送
る。The current I DC is measured by the device shown in FIG. Since the current amount I DC when the film thickness is 15 μm is 27 μA, when the voltage generated across the resistor R1 of 10 kΩ by the current I DC exceeds 0.27 V corresponding to 27 μA, as shown in FIG. In conjunction with this, a warning lamp (not shown) provided on the surface of the apparatus main body is turned on. Specifically, 10
The voltage V across the resistor R1 of kΩ is set to the reference voltage Vref. = 0.27 V, and when the output of the comparator Y is present, a signal of the photosensitive drum life, that is, the process cartridge life is sent to the DC controller 23.
【００５７】本実施例に於いて、感光体の膜厚検知時
に、感光ドラム１より当接部材を離間させて電流測定す
なわち膜厚検知の精度を向上させるために、現像ローラ
３ｓ及び転写ドラム５を離間させたけれども、ブレード
やローラ等を用いたクリーニング装置や中間転写方式に
用いる中間転写体など、感光体に当接するすべての部材
についても、感光体膜厚検知時に、感光ドラムより離間
することにより膜厚検知の精度を向上できることは言う
までもない。In this embodiment, when the film thickness of the photoconductor is detected, the abutting member is separated from the photosensitive drum 1 to improve the current measurement, that is, the film thickness detection accuracy, and the developing roller 3s and the transfer drum 5 are used. However, all members that come into contact with the photoconductor, such as cleaning devices that use blades and rollers, and intermediate transfer bodies that are used in the intermediate transfer system, must also be separated from the photoconductor drum when the photoconductor film thickness is detected. It goes without saying that the accuracy of film thickness detection can be improved by this.
【００５８】ロ）プロセスカートリッジＡの装着有無検
知 感光ドラム１に流れる直流電流ＩDCにより、感光ドラム
１を含むプロセスカートリッジＡの装着の有無を検知す
る手段について説明する。この検知はプリンター本体の
電源投入時及び、本体のドア開閉時毎に行なえば良い。(B) Detection of Presence / Absence of Installation of Process Cartridge A A means for detecting the presence / absence of installation of the process cartridge A including the photosensitive drum 1 by the direct current I DC flowing in the photosensitive drum 1 will be described. This detection may be performed when the power of the printer main body is turned on and each time the door of the main body is opened and closed.
【００５９】検知の基本的思想は上述イ）で説明した感
光体膜厚の検知方法と同じで、感光体表面電位をＶd →
０下降させるときに感光体に流れるＤＣ電流ＩDCを測定
する方式であり、電流ＩDCは感光ドラム１より現像ロー
ラ３ｓ及び転写ドラム５を離間し測定する。図６は感光
体（プロセスカートリッジ）の有無検知回路である。The basic idea of the detection is the same as the method of detecting the film thickness of the photoconductor described in (a) above.
0 is a method for measuring the DC current I DC flowing through the photoreceptor when lowering, the current I DC to separated the development roller 3s and the transfer drum 5 from the photosensitive drum 1 measured. FIG. 6 shows a presence / absence detection circuit for the photosensitive member (process cartridge).
【００６０】感光体に流れるＤＣ電流ＩDCの測定方法は
前述と同様であり、最初に帯電ローラ２によって感光体
表面を一定電位ほぼ−７００Ｖに均一に帯電した後、感
光ドラム１を除電する。The method of measuring the DC current I DC flowing through the photosensitive member is the same as that described above. First, the surface of the photosensitive member is uniformly charged by the charging roller 2 to a constant potential of about −700 V, and then the photosensitive drum 1 is discharged.
【００６１】除電時、感光ドラム１に流れる直流電流Ｉ
DCは前述の関係式で表される。図７に、ε＝３、ε0
＝８．８５×１０-12［Ｆ／ｍ］、Ｌ＝２３０ｍｍ、vp
＝１００［ｍｍ／ｓｅｃ］、Ｖd ＝−７００Ｖのとき
の、ＩDCとｄの関係を示す。本実施例に用いる感光体の
ＣＴ層の初期膜厚は２５μｍであり、この膜厚に対する
電流量ＩDCは図７より１７μＡに相当する。感光体ＣＴ
層は通紙耐久によって削れ膜厚が減少するため電流値は
増加する。At the time of static elimination, a direct current I flowing through the photosensitive drum 1
DC is represented by the above-mentioned relational expression. In FIG. 7, ε = 3, ε0
= 8.85 × 10 -12 [F / m], L = 230 mm, vp
= 100 [mm / sec] and Vd = -700 V, the relationship between I DC and d is shown. The initial thickness of the CT layer of the photoconductor used in this example is 25 μm, and the current amount I DC with respect to this thickness is 17 μA from FIG. Photoconductor CT
The current value increases because the layer is scraped due to the paper passing durability and the film thickness is reduced.
【００６２】一方、この電流の検知時に感光ドラム１を
含むプロセスカートリッジＡが装置内に配置されていな
ければ検知電流ＩDCは０になる点に注目し、０と１７μ
Ａの間に閾値を定め、電流値が閾値以下の時、カートリ
ッジＡが装置内に配設されていないものと判断し、プリ
ントを行なわず、カートリッジ装着なしをユーザーに知
らせる。本実施例では電流の閾値を１０μＡに定めた。
具体的には、図６の回路に於いて１０ｋΩの抵抗器Ｒ１
の両端の電圧Ｖを基準電圧源２４の基準電圧Ｖｒｅｆ．
＝０．１０Ｖと比較し、コンパレータＸの出力によりＤ
Ｃコントローラ２３にてカートリッジＡの有無を判断す
る。[0062] On the other hand, focuses on a point process cartridge A including the photosensitive drum 1 during the detection of this current is to be detected current I DC is 0 if it is not located within the device, 0 and 17μ
A threshold value is set between A and when the current value is equal to or less than the threshold value, it is determined that the cartridge A is not installed in the apparatus, printing is not performed, and the user is informed that the cartridge is not installed. In this embodiment, the current threshold value is set to 10 μA.
Specifically, in the circuit of FIG. 6, a resistor R1 of 10 kΩ is used.
Of the reference voltage Vref. Of the reference voltage source 24.
= 0.10V, and output D from the comparator X
The C controller 23 determines the presence / absence of the cartridge A.
【００６３】このように、プロセスカートリッジＡの装
着有無検知に、感光体に流れる電流を測定する方式を用
いることにより、装置の低価格化、小型化を実現でき
た。As described above, by using the method of measuring the current flowing through the photosensitive member to detect whether or not the process cartridge A is mounted, the cost and size of the apparatus can be reduced.
【００６４】更に本実施例のように感光体膜厚検知手段
と併用する場合、膜厚検知回路にわずかな変更を加える
だけで行なえるので、装置の更なる低価格化、小型化が
実現できる。Further, when used in combination with the photosensitive member film thickness detecting means as in the present embodiment, it can be carried out by making a slight change to the film thickness detecting circuit, so that further cost reduction and downsizing of the device can be realized. .
【００６５】像担持体としての感光体に流れる電流の測
定時に、感光体に当接している部材を感光体から離間さ
せず、感光体に当接あるいは近接している部材を感光体
表面電位と同電位の電位ないし０Ｖにすることで、これ
によっても該部材と感光体の間に電流が生じることを防
止できるので、正確な電流検知ができ、感光体の膜厚検
知精度が向上する。At the time of measuring the current flowing through the photoconductor as the image bearing member, the member abutting on the photoconductor is not separated from the photoconductor, and the member abutting or approaching the photoconductor is set to the photoconductor surface potential. By setting the potential to the same potential or 0 V, it is possible to prevent current from being generated between the member and the photoconductor, so that the current can be accurately detected and the film thickness detection accuracy of the photoconductor is improved.
【００６６】像担持体としての電子写真感光体の層構
成、適用する作像プロセス等は実施例のものに限定され
るものではない。像担持体はドラム型に限らず、回動ベ
ルト型、走行ウエブ型などとすることもできる。像担持
体が静電記録誘電体等であってもよい。像担持体を単独
に交換する構成の装置についても本発明を適用できるこ
とは勿論である。The layer structure of the electrophotographic photosensitive member as the image bearing member, the image forming process to be applied and the like are not limited to those of the embodiment. The image carrier is not limited to the drum type, but may be a rotating belt type, a traveling web type, or the like. The image carrier may be an electrostatic recording dielectric or the like. It goes without saying that the present invention can be applied to an apparatus having a configuration in which the image carrier is independently replaced.
【００６７】[0067]
【発明の効果】以上のように本発明によれば、像担持体
の寿命判定等のための、電流測定による像担持体の膜厚
検知精度の向上を図ることができる。As described above, according to the present invention, it is possible to improve the accuracy of detecting the film thickness of the image carrier by measuring the current, for determining the life of the image carrier.
【００６８】またこの像担持体に流れる電流を測定する
方式を用いることにより、画像形成装置本体に対する像
担持体あるいは像担持体を含むプロセスカートリッジの
装着有無検知と、像担持体あるいは像担持体を含むプロ
セスカートリッジの寿命検知の両検知を共通の手段構成
で行なわせて、装置の簡素化・低価格化・小型化を図る
ことができる。By using the method of measuring the current flowing through the image carrier, it is possible to detect whether the image carrier or the process cartridge including the image carrier is attached to the main body of the image forming apparatus and detect the image carrier or the image carrier. It is possible to achieve simplification, cost reduction, and downsizing of the apparatus by making both the detection of the life of the process cartridge including the detection of the life with a common means configuration.
【図１】実施例の画像形成装置の概略構成図FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment.
【図２】現像器の現像ローラ及び転写ドラムを感光ドラ
ムから離間させた状態時の概略構成図FIG. 2 is a schematic configuration diagram when a developing roller and a transfer drum of a developing device are separated from a photosensitive drum.
【図３】感光体を流れる電流の説明図FIG. 3 is an explanatory diagram of a current flowing through a photoconductor.
【図４】感光体を流れる直流電流ＩDCと帯電ローラへの
印加電圧の図FIG. 4 is a diagram showing a DC current I DC flowing through a photoconductor and a voltage applied to a charging roller.
【図５】感光体膜厚検知回路図FIG. 5: Photosensitive film thickness detection circuit diagram
【図６】感光ドラムを含むプロセスカートリッジの装着
有無検知回路図FIG. 6 is a circuit diagram of presence / absence detection circuit of a process cartridge including a photosensitive drum.
【図７】直流電流ＩDCと感光体膜厚ｄの関係グラフFIG. 7 is a graph showing the relationship between the direct current I DC and the photoconductor film thickness d.
１ 像担持体としての感光ドラム ２ 帯電手段としての帯電ローラ ３ 回転切換え式の現像装置 ３ａ〜３ｄ 現像器 ３ｓ 現像ローラ ４ 露光手段としてのレーザースキャナ ５ 転写ドラム ６ 定着装置 ７ クリーニング装置 Ａ プロセスカートリッジ DESCRIPTION OF SYMBOLS 1 Photosensitive drum as an image bearing member 2 Charging roller as a charging means 3 Rotation-switching type developing device 3a to 3d Developing device 3s Developing roller 4 Laser scanner 5 as an exposing means 5 Transfer drum 6 Fixing device 7 Cleaning device A Process cartridge
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｇ０３Ｇ 21/18 Ｇ０３Ｇ 15/00 ５５６ (72)発明者 斎藤 益朗 東京都大田区下丸子３丁目30番２号 キヤ ノン株式会社内 (72)発明者 榎本 直樹 東京都大田区下丸子３丁目30番２号 キヤ ノン株式会社内 (72)発明者 小林 哲也 東京都大田区下丸子３丁目30番２号 キヤ ノン株式会社内 (72)発明者 笹目 裕志 東京都大田区下丸子３丁目30番２号 キヤ ノン株式会社内 (72)発明者 小林 達也 東京都大田区下丸子３丁目30番２号 キヤ ノン株式会社内 (72)発明者 藤井 春夫 東京都大田区下丸子３丁目30番２号 キヤ ノン株式会社内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Reference number within the agency FI Technical display location G03G 21/18 G03G 15/00 556 (72) Inventor Mashiro Saito 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 in Canon Inc. (72) Inventor Naoki Enomoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tetsuya Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Non-Incorporated (72) Inventor Hiroshi Sasame 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tatsuya Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Haruo Fujii 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.
Claims (11)
持体の膜厚測定時、像担持体に当接している部材の少な
くとも１つを像担持体から離間することを特徴とする像
担持体の膜厚測定方法。1. An image carrier, wherein at least one member in contact with the image carrier is separated from the image carrier when the film thickness of the image carrier is measured by measuring a current flowing through the image carrier. How to measure body thickness.
持体の膜厚測定時、像担持体に当接あるいは近接してい
る部材を像担持体表面と同電位の電位ないし０Ｖにする
ことを特徴とする像担持体の膜厚測定方法。2. When measuring the film thickness of an image bearing member by measuring the current flowing through the image bearing member, a member which is in contact with or close to the image bearing member is set to the same potential or 0 V as the surface of the image bearing member. A method for measuring the film thickness of an image carrier, which comprises:
記録誘電体であることを特徴とする請求項１または請求
項２に記載の像担持体の膜厚測定方法。3. The method for measuring the film thickness of an image carrier according to claim 1, wherein the image carrier is an electrophotographic photosensitive member or an electrostatic recording dielectric.
形成を実行させ、像担持体は繰り返して作像に供する画
像形成装置において、 像担持体を流れる電流を測定する手段と、その測定電流
により像担持体あるいは像担持体を含むプロセスカート
リッジの装置本体に対する装着の有無を判断する手段を
有することを特徴とする画像形成装置。4. An image forming apparatus in which an image forming process is applied to an image bearing member to perform image formation, and the image bearing member is repeatedly subjected to image forming, a means for measuring a current flowing through the image bearing member, and An image forming apparatus having means for determining whether or not an image carrier or a process cartridge including the image carrier is mounted on a main body of the apparatus according to a measurement current.
て像担持体あるいは像担持体を含むプロセスカートリッ
ジの寿命を判断する手段を有することを特徴とする請求
項４に記載の画像形成装置。5. An image forming apparatus according to claim 4, further comprising means for measuring the film thickness of the image bearing member with a measuring current to determine the life of the image bearing member or the process cartridge including the image bearing member. apparatus.
体に当接している部材の少なくとも１つを像担持体から
離間することを特徴とする請求項４に記載の画像形成装
置。6. The image forming apparatus according to claim 4, wherein at least one of the members in contact with the image carrier is separated from the image carrier when the current flowing through the image carrier is measured.
体に当接あるいは近接している部材を像担持体表面と同
電位の電位ないし０Ｖにすることを特徴とする請求項４
に記載の画像形成装置。7. The member, which is in contact with or close to the image carrier, is set to the same potential or 0 V as the surface of the image carrier when measuring the current flowing through the image carrier.
The image forming apparatus according to item 1.
記録誘電体であることを特徴とする請求項４に記載の画
像形成装置。8. The image forming apparatus according to claim 4, wherein the image carrier is an electrophotographic photosensitive member or an electrostatic recording dielectric.
像手段またはクリーニング手段と像担持体とを一体的に
カートリッジ化し、このカートリッジを画像形成装置本
体に着脱可能とするものであることを特徴とする請求項
４に記載の画像形成装置。9. The process cartridge is characterized in that the charging means, the developing means or the cleaning means and the image carrier are integrally formed into a cartridge, and the cartridge can be attached to and detached from the main body of the image forming apparatus. Item 4. The image forming apparatus according to item 4.
現像手段、クリーニング手段の少なくとも一つと像担持
体とを一体的にカートリッジ化して画像形成装置本体に
着脱可能とするものであることを特徴とする請求項４に
記載の画像形成装置。10. The process cartridge comprises a charging means,
5. The image forming apparatus according to claim 4, wherein at least one of the developing unit and the cleaning unit and the image carrier are integrally made into a cartridge so as to be attachable to and detachable from the main body of the image forming apparatus.
現像手段と像担持体とを一体的にカートリッジ化して画
像形成装置本体に着脱可能とするものであることを特徴
とする請求項４に記載の画像形成装置。11. The image forming apparatus according to claim 4, wherein at least the developing means and the image carrier are integrally formed into a cartridge so that the process cartridge can be attached to and detached from the main body of the image forming apparatus. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7055006A JPH08220935A (en) | 1995-02-20 | 1995-02-20 | Method for measuring film thickness of image carrier and image forming device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7055006A JPH08220935A (en) | 1995-02-20 | 1995-02-20 | Method for measuring film thickness of image carrier and image forming device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08220935A true JPH08220935A (en) | 1996-08-30 |
Family
ID=12986579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7055006A Pending JPH08220935A (en) | 1995-02-20 | 1995-02-20 | Method for measuring film thickness of image carrier and image forming device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08220935A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5907739A (en) * | 1996-03-05 | 1999-05-25 | Canon Kabushiki Kaisha | Image forming apparatus |
| US6591072B2 (en) | 2000-10-31 | 2003-07-08 | Canon Kabushiki Kaisha | Image forming apparatus with changeable toner returning electric field application period |
| JP2007187931A (en) * | 2006-01-13 | 2007-07-26 | Fuji Xerox Co Ltd | Device and method for measuring film thickness |
| JP2010139778A (en) * | 2008-12-11 | 2010-06-24 | Canon Inc | Image forming apparatus |
| JP2011138129A (en) * | 2009-12-28 | 2011-07-14 | Xerox Corp | Apparatus and method for determining photoreceptor charge transport layer thickness of apparatus using scorotron charge device |
| US9891561B2 (en) | 2016-02-04 | 2018-02-13 | Konica Minolta, Inc. | Image forming device and method of acquiring photoreceptor layer thickness |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05223513A (en) * | 1992-02-07 | 1993-08-31 | Canon Inc | Detecting apparatus for thickness of body to be electrified, electrifying apparatus and image forming apparatus |
| JPH063891A (en) * | 1992-06-19 | 1994-01-14 | Canon Inc | Image forming device |
| JPH06348083A (en) * | 1993-06-07 | 1994-12-22 | Stanley Electric Co Ltd | Method and device for detecting deterioration of photosensitive body for copying machine |
-
1995
- 1995-02-20 JP JP7055006A patent/JPH08220935A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05223513A (en) * | 1992-02-07 | 1993-08-31 | Canon Inc | Detecting apparatus for thickness of body to be electrified, electrifying apparatus and image forming apparatus |
| JPH063891A (en) * | 1992-06-19 | 1994-01-14 | Canon Inc | Image forming device |
| JPH06348083A (en) * | 1993-06-07 | 1994-12-22 | Stanley Electric Co Ltd | Method and device for detecting deterioration of photosensitive body for copying machine |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5907739A (en) * | 1996-03-05 | 1999-05-25 | Canon Kabushiki Kaisha | Image forming apparatus |
| US6591072B2 (en) | 2000-10-31 | 2003-07-08 | Canon Kabushiki Kaisha | Image forming apparatus with changeable toner returning electric field application period |
| JP2007187931A (en) * | 2006-01-13 | 2007-07-26 | Fuji Xerox Co Ltd | Device and method for measuring film thickness |
| JP2010139778A (en) * | 2008-12-11 | 2010-06-24 | Canon Inc | Image forming apparatus |
| JP2011138129A (en) * | 2009-12-28 | 2011-07-14 | Xerox Corp | Apparatus and method for determining photoreceptor charge transport layer thickness of apparatus using scorotron charge device |
| US9891561B2 (en) | 2016-02-04 | 2018-02-13 | Konica Minolta, Inc. | Image forming device and method of acquiring photoreceptor layer thickness |
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