JPH08334956A - Image forming device - Google Patents

Image forming device

Info

Publication number
JPH08334956A
JPH08334956A JP7160011A JP16001195A JPH08334956A JP H08334956 A JPH08334956 A JP H08334956A JP 7160011 A JP7160011 A JP 7160011A JP 16001195 A JP16001195 A JP 16001195A JP H08334956 A JPH08334956 A JP H08334956A
Authority
JP
Japan
Prior art keywords
image
film thickness
image carrier
forming apparatus
image forming
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
Application number
JP7160011A
Other languages
Japanese (ja)
Inventor
Yoichiro Maehashi
洋一郎 前橋
Takaaki Tsuruya
鶴谷  貴明
Hiroshi Sasame
裕志 笹目
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to JP7160011A priority Critical patent/JPH08334956A/en
Publication of JPH08334956A publication Critical patent/JPH08334956A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To improve film-thickness detection accuracy, in an image forming device equipped with a film-thickness judge means which detects a current flowing in an image carrier when an electrifying member electrifies or discharges the image carrier, and which judges the film thickness of the image carrier based on the current signal. CONSTITUTION: The value of a voltage which is applied to the electrifying member 2 when the image carrier 1 is electrified, is different between at the time of image formation and at the time of film-thickness judgement. In the absolute value of the voltage which is applied to the electrifying member 2 at the time of electrifying the image carrier, a value at the film-thickness judgment is larger than a value at the image formation. The device is equipped with a temperature/humidity detection means 11 which detects the temperature or/and humidity in the main body of the device, and a means 9 which varies and controls the value of the voltage which is applied to the electrifying member 2 according to the output value of the means 11.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、レーザビームプリンタ
や電子写真装置等の画像形成装置に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a laser beam printer or an electrophotographic apparatus.

【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(被帯電体)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トナー等が除去され清掃され、繰
り返して作像に使用される。
2. Description of the Related Art For example, in an image forming apparatus such as an electrophotographic printer (ex. Carlson process) such as a printer or a copying machine, a rotary drum type electrophotographic photosensitive member is generally used as an image bearing member (charged member). A known image forming process of charging, exposing, and developing is applied to this to form and carry a toner image corresponding to target image information, and the toner image is transferred to a transfer material by a transfer means, and the transferred toner image is transferred. The fixing means fixes the transfer material as a permanently fixed image, and outputs the transfer material as an image-formed product (print / copy). 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 a cleaning unit, and is repeatedly used for image formation.

【0003】上記のような、画像形成装置に於いては、
像担持体としての感光体はクリーニング手段で転写残ト
ナー等が除去されて清掃されるといえども、繰り返し使
用されていくうちには転写材の成分や帯電時の放電生成
物などによって次第に汚染されていく。
In the image forming apparatus as described above,
Although the photoconductor serving as the image carrier is cleaned by removing the residual toner after transfer by the cleaning means, it is gradually contaminated by the components of the transfer material and the discharge products at the time of charging while being repeatedly used. To go.

【0004】このように、感光体が汚染されてくると表
面の抵抗が下がって静電潜像を乱してしまったり、トナ
ーやその成分が感光体表面に融着し、著しく画像を損ね
てしまう結果となる。近年、レーザープリンター等の画
像形成装置は、高画質化の要望が強く、解像度で言え
ば、600dpiや800dpi、またPWM(パルス幅変調)等の
画像処理を行なった多値画像化といった方向に進んでき
ており、僅かな感光体汚染でも画像上に現われてしま
う。
As described above, when the photoconductor is contaminated, the resistance of the surface is lowered and the electrostatic latent image is disturbed, or the toner and its components are fused to the photoconductor surface, and the image is remarkably damaged. Will result. In recent years, image forming apparatuses such as laser printers are strongly demanded to have high image quality, and in terms of resolution, they are moving toward multi-valued image processing with image processing such as 600 dpi or 800 dpi and PWM (pulse width modulation). However, even a slight contamination of the photoconductor appears on the image.

【0005】そこで、従来の画像形成装置ではクリーニ
ングブレードにより感光ドラム表面を積極的に研磨し表
面をリフレッシュすることによって良好な画像を維持し
ているが、その結果、感光層膜厚は耐久通紙と伴に次第
に減少する。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き、電荷を与えるとそれが保
持され、表面電位として現れる。
Therefore, in the conventional image forming apparatus, the surface of the photosensitive drum is positively polished by the cleaning blade to refresh the surface to maintain a good image. As a result, the thickness of the photosensitive layer is durable. It gradually decreases with. The photoconductor acts as a capacitor in a dark portion (a portion not exposed to light), and when an electric charge is applied, it is retained and appears as a surface potential.

【0006】しかし、感光体の膜厚があまり薄くなる
と、帯電器で与えられる電荷量には限界があるので、表
面電位の低下を招いたり、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帯電不良
につながりかねない。
However, when the film thickness of the photoconductor is too thin, the amount of electric charge given by the charger is limited, so that the surface potential is lowered, and the film of the photoconductor has some defects. Therefore, the charge may locally escape, which may lead to poor charging.

【0007】従って、良好な画像を維持するためには、
最低限必要な膜厚がある。例えばOPC感光体では、最
上層である電荷輸送層(CT層)の最低膜厚は10μm
であり、感光体はCT層の膜厚が10μmに達したとき
寿命となる。
Therefore, in order to maintain a good image,
There is a minimum required film thickness. For example, in an OPC photosensitive member, the minimum thickness of the uppermost charge transport layer (CT layer) is 10 μm.
Thus, the photoconductor reaches the end of its life when the thickness of the CT layer reaches 10 μm.

【0008】つまり、像担持体としての感光体は消耗品
であるため、その寿命によって交換が余儀なくされる。
そこで、感光体の膜厚を検知し、膜厚が限界まで減少し
たときに感光体寿命をユーザーに知らせる機能を設けて
ある。
That is, since the photosensitive member as the image bearing member is a consumable item, it must be replaced due to its life.
Therefore, a function is provided to detect the film thickness of the photoconductor and inform the user of the photoconductor life when the film thickness is reduced to the limit.

【0009】感光体の膜厚は、感光体の前述のコンデン
サーとしての特性を利用することにより、感光体を帯電
した状態から電荷を除去したとき、或は電荷を除去した
状態から帯電したときに感光体を流れる電流より算出で
きる(特開平5−53488号公報)。
The film thickness of the photoconductor is obtained by utilizing the above-mentioned characteristics of the photoconductor as a capacitor when the charge is removed from the charged state of the photoconductor or when the charge is removed from the charged state. It can be calculated from the current flowing through the photoconductor (Japanese Patent Laid-Open No. 5-53488).

【0010】簡単に説明すると、感光体表面電位を0→
Vdpt.に上昇、或はVdpt.→0下降させるとき
に感光体に流れるDC電流IDC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次ローラ
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。
Briefly, the surface potential of the photoconductor is set to 0 →
Vdpt. , Or Vdpt. → The DC current IDC flowing to the photoconductor when it is lowered by 0 is the film thickness of the photoconductor, the relative permittivity ε, the permittivity in vacuum ε0, the effective charging width of the primary roller charger L, the process When the speed is vp, it is expressed by the following relational expression.

【0011】 |IDC| = ε・ε0・L・vp・Vdpt/d ・・・・ ここで、ε、ε0、L、vp、Vdpt.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d
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できる(特開平
5−223513号公報)。
| IDC | = ε · ε0 · L · vp · Vdpt / d, where ε, ε0, L, vp, Vdpt. Can be regarded as a constant, the DC current IDC is the film thickness d of the photoconductor.
Is inversely proportional to. Therefore, the film thickness of the photoconductor can be detected by measuring the DC current IDC (JP-A-5-223513).

【0012】また、感光体電流IDCは感光体のグラン
ドに接続された電流検出抵抗の両端に生じる電圧から算
出する。
The photoconductor current IDC is calculated from the voltage generated across the current detection resistor connected to the ground of the photoconductor.

【0013】前述のような、感光体の膜厚を直接測定す
ることにより感光体の寿命を検出する方法には以下のよ
うなメリットがある。即ち、プリント枚数あたりの感光
体の削れ量は、装置の使用環境(温度、湿度等)により
大きく変化するが、感光体の膜厚を直接測定すれば、あ
らゆる使用条件下で感光体を限界まで使いきることが可
能になる。従って、プリント枚数により感光体の寿命を
判断するような方法に比べ、感光体の長寿命化を実現で
き、ランニングコストを最小限に抑えることができる。
The above-described method for detecting the life of the photoconductor by directly measuring the film thickness of the photoconductor has the following merits. That is, the amount of photoconductor scraping per number of prints varies greatly depending on the operating environment (temperature, humidity, etc.) of the device, but if the film thickness of the photoconductor is directly measured, the photoconductor will reach the limit under all use conditions. It can be used up. Therefore, the life of the photoconductor can be extended and the running cost can be minimized as compared with the method of determining the life of the photoconductor by the number of prints.

【0014】上述の膜厚検知手段は、感光体の寿命検出
のみならず、感光体の装着有無判断、感光体の交換有無
判断等にも利用されている。
The above-mentioned film thickness detecting means is used not only for detecting the life of the photosensitive member but also for determining whether or not the photosensitive member is mounted, determining whether or not the photosensitive member has been replaced.

【0015】特に、感光体を含むプロセスカートリッジ
の寿命判断、装着有無判断、交換有無判断には有効な手
段である。
In particular, it is an effective means for judging the life of the process cartridge including the photoconductor, the presence / absence of attachment, and the presence / absence of replacement.

【0016】[0016]

【発明が解決しようとする課題】しかしながら、本発明
者らが検討を重ねた結果、前述のような感光体膜厚検知
方法を用いる画像形成装置には、以下の不具合があっ
た。
However, as a result of repeated studies by the present inventors, the image forming apparatus using the above-described method for detecting the film thickness of the photoconductor has the following problems.

【0017】(a)従来の画像形成装置では、感光体の
膜厚検知時に感光体を帯電する電圧(Vdpt.)が、
画像形成時の帯電電圧(以下Vd)と等しく定められて
いたため、例えば濃度調整用ボリュームや環境制御等に
よりVdを変化させた場合、Vdpt.も連動して変化
してしまうので、前述式の検知電流IDCが変わって
しまい、結果、膜厚を正確に検知できなくなる。
(A) In the conventional image forming apparatus, the voltage (Vdpt.) For charging the photoconductor when the film thickness of the photoconductor is detected is
Since it is set to be equal to the charging voltage (hereinafter, Vd) at the time of image formation, when Vd is changed by, for example, the density adjusting volume or environmental control, Vdpt. Since it also changes in conjunction with the above, the detection current IDC in the above equation changes, and as a result, the film thickness cannot be accurately detected.

【0018】(b)膜厚検知時に、感光体を流れる電流
は非常に小さい為、電流検出抵抗で得られる電圧も小さ
く、従って検知精度を上げることが難しい。また、検出
電圧を大きくするために検出抵抗値を大きくすると、検
出抵抗に帯電時の印加電圧が多く分圧してしまうので好
ましくない。
(B) When the film thickness is detected, the current flowing through the photoconductor is very small, so the voltage obtained by the current detection resistor is also small, and therefore it is difficult to improve the detection accuracy. Further, if the detection resistance value is increased in order to increase the detection voltage, the voltage applied to the detection resistance during charging is largely divided, which is not preferable.

【0019】(c)画像形成装置の使用環境は高温高湿
から低温低湿まで様々であるが、電流検出抵抗で得られ
る検出電圧を、膜厚検出回路内の増幅回路で増幅したの
ち、膜厚に換算する場合、増幅回路の温度特性が大きい
と、環境の変化によって、検出膜厚が変化してしまう。
(C) The environment in which the image forming apparatus is used varies from high temperature and high humidity to low temperature and low humidity, but after the detection voltage obtained by the current detection resistor is amplified by the amplification circuit in the film thickness detection circuit, the film thickness is measured. If the temperature characteristic of the amplifier circuit is large, the detected film thickness will change due to changes in the environment.

【0020】本発明は、帯電部材で像担持体を帯電或は
除電する際に像担持体を流れる電流を検知し、その電流
信号より像担持体の膜厚を判断する膜厚判断手段を有す
る画像形成装置について、上述のような問題点を解消す
ること、即ち像担持体の膜厚を正確に検知すること、膜
厚検知の精度を向上することを目的とする。
The present invention has a film thickness judging means for detecting the current flowing through the image carrier when the image carrier is charged or discharged by the charging member and judging the film thickness of the image carrier from the current signal. An object of the image forming apparatus is to solve the above-mentioned problems, that is, to accurately detect the film thickness of the image carrier and to improve the accuracy of film thickness detection.

【0021】[0021]

【課題を解決するための手段】本発明は下記の構成を特
徴とする画像形成装置である。
The present invention is an image forming apparatus having the following configuration.

【0022】(1)帯電部材に電圧を印加し、被帯電体
としての像担持体を所定電位に帯電或は除電する手段
と、像担持体を帯電或は除電する際に像担持体を流れる
電流信号を検知する電流検知手段と、前記電流信号より
像担持体の膜厚を判断する膜厚判断手段を有する画像形
成装置において、像担持体に帯電を行う際に帯電部材に
印加する電圧値は、画像形成時と膜厚判断時とで異なる
ことを特徴とする画像形成装置。
(1) A means for applying a voltage to a charging member to charge or discharge an image carrier as a member to be charged to a predetermined potential, and a means for flowing through the image carrier when charging or discharging the image carrier. In an image forming apparatus having a current detection unit that detects a current signal and a film thickness determination unit that determines the film thickness of the image carrier from the current signal, the voltage value applied to the charging member when the image carrier is charged. The image forming apparatus is characterized in that it is different when the image is formed and when the film thickness is judged.

【0023】(2)帯電部材に電圧を印加し、被帯電体
としての像担持体を所定電位に帯電或は除電する手段
と、像担持体を帯電或は除電する際に像担持体を流れる
電流信号を検知する電流検知手段と、前記電流信号より
像担持体の膜厚を判断する膜厚判断手段を有する画像形
成装置において、像担持体に帯電を行う際に帯電部材に
印加する電圧の絶対値は、画像形成時の値よりも膜厚判
断時の値が大きいことを特徴とする画像形成装置。
(2) A means for applying a voltage to the charging member to charge or discharge the image carrier as a member to be charged to a predetermined potential, and a means for flowing the image carrier when charging or discharging the image carrier. In an image forming apparatus having a current detection unit that detects a current signal and a film thickness determination unit that determines the film thickness of the image carrier based on the current signal, the voltage applied to the charging member when the image carrier is charged. The image forming apparatus is characterized in that the absolute value is larger in the film thickness determination than in the image forming.

【0024】(3)画像形成時に像担持体に帯電を行う
際に帯電部材に印加される電圧値が可変制御されている
ことを特徴とする(1)または(2)に記載の画像形成
装置。
(3) The image forming apparatus according to (1) or (2), wherein the voltage value applied to the charging member when the image carrier is charged during image formation is variably controlled. .

【0025】(4)膜厚判断時に像担持体に帯電を行う
際に帯電部材に印加される電圧値が可変制御されている
ことを特徴とする(1)または(2)に記載の画像形成
装置。
(4) The image formation according to (1) or (2), wherein the voltage value applied to the charging member when the image carrier is charged when the film thickness is judged is variably controlled. apparatus.

【0026】(5)画像形成時に像担持体に帯電を行う
際に帯電部材に印加される電圧値と、膜厚判断時に像担
持体に帯電を行う際に帯電部材に印加される電圧値とが
各々独立で可変制御されていることを特徴とする(1)
または(2)に記載の画像形成装置。
(5) A voltage value applied to the charging member when the image carrier is charged during image formation, and a voltage value applied to the charging member when the image carrier is charged during the film thickness determination. Is independently and variably controlled (1)
Alternatively, the image forming apparatus according to (2).

【0027】(6)装置本体内の温度と湿度のどちらか
一方或は両方を検知する温度湿度検知手段と、前記温度
湿度検知手段の出力値に応じ帯電部材に印加される電圧
値を可変制御する手段とを有することを特徴とする
(3)乃至(5)の何れか1つに記載の画像形成装置。
(6) Temperature / humidity detecting means for detecting either or both of the temperature and humidity inside the apparatus main body, and the voltage value applied to the charging member is variably controlled according to the output value of the temperature / humidity detecting means. The image forming apparatus according to any one of (3) to (5), further comprising:

【0028】(7)帯電部材が像担持体に当接すること
を特徴とする(1)乃至(6)の何れか1つに記載の画
像形成装置。
(7) The image forming apparatus according to any one of (1) to (6), wherein the charging member is in contact with the image carrier.

【0029】(8)像担持体が電子写真感光体或は静電
記録誘電体であることを特徴とする(1)乃至(7)の
何れか1つに記載の画像形成装置。
(8) The image forming apparatus described in any one of (1) to (7), wherein the image bearing member is an electrophotographic photosensitive member or an electrostatic recording dielectric member.

【0030】(9)像担持体は画像形成装置本体に対し
て着脱されるプロセスカートリッジに包含されているこ
とを特徴とする(1)乃至(8)の何れか1つに記載の
画像形成装置。
(9) The image forming apparatus according to any one of (1) to (8), wherein the image carrier is included in a process cartridge that is attached to and detached from the main body of the image forming apparatus. .

【0031】[0031]

【作用】像担持体の膜厚検知時(膜厚判断時)に像担持
体を帯電する電圧Vdpt.を、画像形成時の帯電電圧
Vdと独立な固定値に定めることにより像担持体膜厚を
正確に検知できる。
When the film thickness of the image carrier is detected (when the film thickness is judged), the voltage Vdpt. Is determined to be a fixed value independent of the charging voltage Vd during image formation, the film thickness of the image carrier can be accurately detected.

【0032】更に、像担持体の膜厚検知時に像担持体を
帯電する電圧Vdpt.を、画像形成時の帯電電圧Vd
より大きな値に定めることにより像担持体膜厚検知の精
度を向上できる。
Further, when the film thickness of the image carrier is detected, the voltage Vdpt. Is the charging voltage Vd during image formation
By setting a larger value, it is possible to improve the accuracy of detecting the image carrier thickness.

【0033】更にまた、像担持体の膜厚検知時に感光体
を帯電する電圧Vdpt.画像形成装置本体内の温度湿
度に応じ制御することにより膜厚検知の精度を向上でき
る。
Furthermore, when the film thickness of the image carrier is detected, the voltage Vdpt. By controlling according to the temperature and humidity inside the main body of the image forming apparatus, the accuracy of film thickness detection can be improved.

【0034】[0034]

【実施例】【Example】

〈実施例1〉(図1・図2) (1)画像形成装置例 図1は本発明に従う画像形成装置の一例の概略構成図で
ある。本例の画像形成装置は、転写方式電子写真プロセ
ス利用の、プロセスカートリッジ着脱式のレーザービー
ムプリンタである。
<Embodiment 1> (FIGS. 1 and 2) (1) Example of image forming apparatus FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus according to the present invention. The image forming apparatus of this example is a laser beam printer using a transfer type electrophotographic process and having a process cartridge detachable type.

【0035】1は像担持体としての回転ドラム型の電子
写真感光体(以下、感光ドラムと記す)であり、不図示
の駆動手段により矢示の時計方向に所定の周速度をもっ
て回転駆動される。本実施例における感光ドラム1は、
ドラム基体としてのアルミシリンダーの外周面に有機感
光体(OPC)から成る光導電体を塗布して構成したO
PC感光体である。
Reference numeral 1 denotes a rotary drum type electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) as an image bearing member, which is rotationally driven in a clockwise direction indicated by an arrow at a predetermined peripheral speed by a driving means (not shown). . The photosensitive drum 1 in this embodiment is
O formed by coating a photoconductor made of an organic photoconductor (OPC) on the outer peripheral surface of an aluminum cylinder as a drum substrate.
It is a PC photoconductor.

【0036】この回転感光ドラム1は帯電装置2により
所定の極性・電位に均一に帯電処理される。本実施例に
おける帯電装置は、帯電部材としての帯電ローラ2を感
光ドラム1に当接させて、該帯電ローラに電源8から所
定の帯電電圧を芯金2aを介して印加して感光ドラム面
を帯電させる接触式のローラ帯電装置である。
The rotating photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by the charging device 2. In the charging device of this embodiment, a charging roller 2 as a charging member is brought into contact with the photosensitive drum 1, and a predetermined charging voltage is applied to the charging roller from a power source 8 via a cored bar 2a, so that the surface of the photosensitive drum is exposed. It is a contact type roller charging device for charging.

【0037】次いで、回転感光ドラム1の均一帯電処理
面に、不図示のレーザースキャナから出力される、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
調されたレーザービームによる走査露光Lがなされるこ
とにより、回転感光ドラム1の面に目的の画像情報に対
応した静電潜像が形成される。
Next, scanning exposure L by a laser beam, which is output from a laser scanner (not shown) and is modulated corresponding to the time-series electric digital pixel signals of the target image information, is applied to the surface of the rotary photosensitive drum 1 which is uniformly charged. As a result, the electrostatic latent image corresponding to the target image information is formed on the surface of the rotary photosensitive drum 1.

【0038】次いで、その回転感光ドラム1面の静電潜
像が現像装置3によってトナー画像として現像される。
Then, the electrostatic latent image on the surface of the rotating photosensitive drum 1 is developed as a toner image by the developing device 3.

【0039】その現像トナー画像が、感光ドラム1と転
写装置としての転写ローラ5との圧接ニップ部である転
写部に対して、不図示の給紙機構部から所定のタイミン
グにて搬送された被記録材としての転写紙7の面に転写
される。
The developed toner image is conveyed to a transfer portion, which is a pressure nip portion between the photosensitive drum 1 and a transfer roller 5 as a transfer device, at a predetermined timing from a paper feed mechanism portion (not shown). The image is transferred onto the surface of the transfer paper 7 as a recording material.

【0040】転写部にてトナー画像転写を受けた転写紙
7は転写部を出て感光ドラム1面から分離されて定着装
置6へ導入され、転写トナー画像の加熱・加圧による定
着処理を受けてプリントアウトされる。
The transfer paper 7 having undergone the toner image transfer at the transfer portion exits the transfer portion, is separated from the surface of the photosensitive drum 1 and is introduced into the fixing device 6, and undergoes a fixing process by heating and pressurizing the transferred toner image. Will be printed out.

【0041】また、転写紙7に対するトナー画像転写後
の感光ドラム1面は公知のブレード式クリーニング装置
4によって転写残トナー等の付着残留汚染物の除去がな
されて清掃され、繰り返して作像に供される。
Further, the surface of the photosensitive drum 1 after the toner image is transferred onto the transfer paper 7 is cleaned by removing adhered residual contaminants such as transfer residual toner by a known blade type cleaning device 4, and repeatedly used for image formation. To be done.

【0042】また感光ドラム1はクリーニングブレード
によりその表面を積極的に少しずつ研磨させてリフレッ
シュすることによって良好な画像を維持させるようにし
ている。
Further, the surface of the photosensitive drum 1 is positively and gradually polished by a cleaning blade to refresh and maintain a good image.

【0043】本例の画像形成装置は、感光ドラム1、帯
電ローラ2、現像装置3、クリーニング装置4の4つの
プロセス機器を一括して画像形成装置本体に対して着脱
交換自在なプロセスカートリッジPとしてある。
The image forming apparatus of the present embodiment is a process cartridge P in which four process devices including the photosensitive drum 1, the charging roller 2, the developing device 3, and the cleaning device 4 are collectively attached to and detachable from the image forming apparatus main body. is there.

【0044】(2)帯電ローラ2に対する印加電圧制御 A)画像形成時 画像形成時においては、感光ドラム帯電部材としての帯
電ローラ2に対して高圧電源(H.V.T)8からローラ芯金
2aを介して直流電圧と交流電圧の重畳電圧である振動
電圧(画像形成時帯電バイアス)を印加されることで、
感光ドラム1の感光層の表面が所定の極性・電位に帯電
される。
(2) Control of Applied Voltage to Charging Roller 2 A) At the time of image formation At the time of image formation, the charging roller 2 as the photosensitive drum charging member is supplied from the high voltage power source (HVT) 8 through the roller core metal 2a. By applying an oscillating voltage (charging bias during image formation), which is a superimposed voltage of a DC voltage and an AC voltage,
The surface of the photosensitive layer of the photosensitive drum 1 is charged with a predetermined polarity and potential.

【0045】本実施例における画像形成時帯電バイアス
は、 周波数1000Hz、Vpp(ピーク・ツー・ピーク)
=1800V の交流電圧に −600V〜−750V(可変) の直流成分を重畳した振動電圧である。
The charging bias during image formation in this embodiment has a frequency of 1000 Hz and Vpp (peak-to-peak).
This is an oscillating voltage obtained by superimposing a DC component of -600V to -750V (variable) on an AC voltage of 1800V.

【0046】11は画像形成装置本体内に具備させた温
度湿度センサーであり、このセンサー11の温度湿度検
知情報が制御回路(C.P.U )9に入力する。
Reference numeral 11 denotes a temperature / humidity sensor provided in the main body of the image forming apparatus, and temperature / humidity detection information of the sensor 11 is input to the control circuit (CPU) 9.

【0047】制御回路9は、センサー11からの入力温
度湿度検知情報に応じて、電源8から帯電ローラ2へ印
加する画像形成時帯電バイアス電圧の直流電圧のセンタ
ー値を−650V(低温低湿環境下)から−700V
(高温高湿環境下)まで環境制御する。更にユーザーが
調整可能な濃度調整ボリュームにより±50Vの調整が
行われている。
The control circuit 9 sets the center value of the DC voltage of the charging bias voltage at the time of image formation to be applied from the power source 8 to the charging roller 2 to -650 V (in a low temperature and low humidity environment) in accordance with the input temperature / humidity detection information from the sensor 11. ) To -700V
Environmental control up to (under high temperature and high humidity environment). Further, the density adjustment volume that can be adjusted by the user is used to adjust ± 50V.

【0048】B)感光体膜厚検知時 前述したように、良好な画像を維持させるために感光ド
ラム表面はクリーニングブレードにより積極的に少しず
つ研磨されてリフレッシュされることで感光層膜厚は耐
久通紙と伴に次第に減少するので、画像形成装置の前回
転行程時・後回転行程時等の所定時に感光体膜厚検知即
ち感光体寿命検知シーケンスが制御回路9で実行され
る。
B) When Photoreceptor Film Thickness is Detected As described above, in order to maintain a good image, the surface of the photosensitive drum is positively abraded by the cleaning blade little by little and refreshed, so that the photosensitive layer thickness is durable. Since the number of sheets gradually decreases with the passage of paper, the control circuit 9 executes the photosensitive member film thickness detection, that is, the photosensitive member life detection sequence at a predetermined time such as during the front rotation stroke and the rear rotation stroke of the image forming apparatus.

【0049】その感光体膜厚検知は、帯電ローラ2で感
光ドラム1を帯電或は除電する際に感光体を流れる電流
を検知し、その電流信号より感光体膜厚の検知がなされ
る。
The photoconductor film thickness is detected by detecting the current flowing through the photoconductor when the charging roller 2 charges or removes the photoconductor drum 1, and the photoconductor film thickness is detected from the current signal.

【0050】而して本実施例では、感光体膜厚検知時
に、最初に周波数1000Hz、Vpp=1800Vの
交流電圧(除電バイアス)を感光ドラム1回転以上印加
し、感光ドラム1の表面電位を0Vに除電する。
Thus, in this embodiment, when the photosensitive member film thickness is detected, an AC voltage (static elimination bias) having a frequency of 1000 Hz and Vpp = 1800V is first applied for one rotation of the photosensitive drum or more to make the surface potential of the photosensitive drum 1 0V. To neutralize.

【0051】次に、周波数1000Hz、Vpp=18
00Vの交流電圧に−700Vの直流電圧を重畳した電
圧(感光体膜厚検知時帯電バイアス)を印加した状態で
感光ドラム1を3周以上回転させ、感光ドラム表面をV
dpt=−700V(帯電ローラ2に印加した電圧の直
流成分電圧に対応)に均一に帯電する。
Next, frequency 1000 Hz, Vpp = 18
The photosensitive drum 1 is rotated three times or more while applying a voltage (charging bias at the time of detecting the photoconductor film thickness) in which a DC voltage of -700V is superimposed on an AC voltage of 00V, and the surface of the photosensitive drum is V
It is uniformly charged to dpt = -700V (corresponding to the DC component voltage of the voltage applied to the charging roller 2).

【0052】更に、周波数1000Hz、Vpp=18
00Vの交流電圧を印加した状態で感光ドラム1を回転
させて感光ドラム表面を再び除電する。
Further, the frequency is 1000 Hz, Vpp = 18
The photosensitive drum 1 is rotated in the state where the AC voltage of 00V is applied, and the surface of the photosensitive drum is removed again.

【0053】この時に感光ドラム1に流れる直流電流I
DCが膜厚検出電流となる。具体的には、感光体電流I
DCは、感光体のグランドに接続された電流検出抵抗R
の両端に生じる電圧情報が増幅器10・A/D(アナロ
グ−デジタル)変換回路12を介して制御回路9へ入力
されて算出される。
At this time, the direct current I flowing through the photosensitive drum 1
DC becomes the film thickness detection current. Specifically, the photoconductor current I
DC is a current detection resistor R connected to the ground of the photoconductor
The voltage information generated at the both ends of is input to the control circuit 9 via the amplifier 10 · A / D (analog-digital) conversion circuit 12 and calculated.

【0054】制御回路9はその算出感光体電流IDCを
もとに感光体の現在膜厚を検知し感光体の寿命判断を行
う。
The control circuit 9 detects the current film thickness of the photoconductor based on the calculated photoconductor current IDC and determines the life of the photoconductor.

【0055】検知膜厚が許容下限以下となったときは感
光ドラム1の寿命が尽きたものとして、その旨の警告表
示手段の作動等の対処動作フローが制御回路9で実行さ
れる。
When the detected film thickness is below the permissible lower limit, it is considered that the photosensitive drum 1 has reached the end of its life, and the control circuit 9 executes a coping operation flow such as operation of the warning display means.

【0056】上述の膜厚検知手段は、感光体の寿命検出
のみならず、感光体の装着有無判断手段、感光体の交換
有無判断手段等にも利用できる。感光体を含むプロセス
カートリッジPを用いる画像形成装置にあっては、その
プロセスカートリッジの寿命判断、該カートリッジの画
像形成装置本体に対する装着有無判断・交換有無判断手
段にも利用できる。
The above-mentioned film thickness detecting means can be used not only for detecting the life of the photoconductor, but also for determining whether or not the photoconductor is mounted, for determining whether or not the photoconductor has been replaced. In the image forming apparatus using the process cartridge P including the photoconductor, it is also possible to use it for the life judgment of the process cartridge, the presence / absence judgment / replacement judgment means of the cartridge with respect to the image forming apparatus body.

【0057】C)従来例との比較 図2により本実施例と従来例との比較を説明する。C) Comparison with Conventional Example A comparison between this embodiment and the conventional example will be described with reference to FIG.

【0058】図2において、縦軸は膜厚検出電流ID
C、横軸は感光体膜厚dを表す。曲線A・B・Cは膜厚
検出時の帯電電位Vdptが−600V、−700V、
−750Vの時のものをそれぞれ表している。
In FIG. 2, the vertical axis indicates the film thickness detection current ID.
C, the horizontal axis represents the photoconductor film thickness d. Curves A, B, and C show that the charging potential Vdpt at the time of film thickness detection is -600V, -700V,
Each of those at -750V is shown.

【0059】従来例では、膜厚検出時の帯電電位Vdp
tは画像形成時の帯電電位Vdと連動しているため、検
出電流と膜厚の関係は曲線A〜Cまで変化していた。つ
まり、例えば感光体の膜厚が20μmの時の検出電流は
15.5μA〜19.3μAまで検知誤差を持ってい
た。
In the conventional example, the charging potential Vdp during film thickness detection
Since t is interlocked with the charging potential Vd at the time of image formation, the relationship between the detected current and the film thickness changes from the curves A to C. That is, for example, when the film thickness of the photoconductor is 20 μm, the detection current has a detection error of 15.5 μA to 19.3 μA.

【0060】一方、本実施例では、膜厚検知時の帯電電
位Vdptは固定値(−700V)であるため、例えば
感光体の膜厚が20μmの時の検出電流値は18.1μ
Aと正確な検知が可能となる。
On the other hand, in this embodiment, since the charging potential Vdpt at the time of detecting the film thickness is a fixed value (-700 V), for example, the detected current value when the film thickness of the photoconductor is 20 μm is 18.1 μ.
Accurate detection with A is possible.

【0061】つまり、感光体の膜厚dと検出電流IDC
の関係が曲線Bで示すごとく1対1で対応され、検知を
正確に行える。
That is, the film thickness d of the photoconductor and the detected current IDC
As shown by the curve B, there is a one-to-one correspondence, and detection can be performed accurately.

【0062】以上、感光体の膜厚検知時に感光体を帯電
する電圧Vdpt.を画像形成時の帯電電圧Vdと独立
な固定値に定めることにより感光体膜厚を正確に検知す
ることが可能となった。
As described above, the voltage Vdpt. It becomes possible to accurately detect the film thickness of the photoconductor by setting a fixed value that is independent of the charging voltage Vd during image formation.

【0063】〈実施例2〉(図3) 本実施例は上述した実施例1において、感光体膜厚検知
時における帯電ローラ2に対する印加電圧制御を次のよ
うにした。他は実施例1と同様である。
<Embodiment 2> (FIG. 3) In this embodiment, the voltage applied to the charging roller 2 at the time of detecting the photosensitive member film thickness is controlled as follows in Embodiment 1 described above. Others are the same as in the first embodiment.

【0064】A)感光体膜厚検知時 最初に周波数1000Hz、Vpp=1800Vの交流
電圧(除電バイアス)を感光ドラム1回転以上印加し、
感光ドラム表面電位を0Vに除電する。
A) At the time of detecting the photoconductor film thickness First, an AC voltage (static elimination bias) having a frequency of 1000 Hz and Vpp = 1800 V is applied for one rotation of the photosensitive drum or more,
The surface potential of the photosensitive drum is eliminated to 0V.

【0065】次に、周波数1000Hz、Vpp=18
00Vの交流電圧に−1500Vの直流電圧を重畳した
電圧(感光体膜厚検知時帯電バイアス)を印加した状態
で感光ドラム1を3周以上回転させ、感光ドラム表面を
Vdpt=−1500Vに均一に帯電する。
Next, frequency 1000 Hz, Vpp = 18
The photosensitive drum 1 is rotated three or more times while applying a voltage (charging bias at the time of detecting the photoconductor film thickness) in which a DC voltage of -1500V is superimposed on an AC voltage of 00V, and the surface of the photosensitive drum is uniformly Vdpt = -1500V. Get charged.

【0066】更に、周波数1000Hz、Vpp=18
00Vの交流電圧を印加した状態で感光ドラム1を回転
させ感光ドラム表面を再び除電する。
Further, the frequency is 1000 Hz, Vpp = 18
The photosensitive drum 1 is rotated while the AC voltage of 00V is applied, and the surface of the photosensitive drum is again neutralized.

【0067】この時に感光ドラム1に流れる直流電流I
DCが膜厚検出電流となる。
At this time, the direct current I flowing through the photosensitive drum 1
DC becomes the film thickness detection current.

【0068】B)従来例との比較 図3により本実施例と従来例との比較を説明する。B) Comparison with Conventional Example A comparison between this embodiment and the conventional example will be described with reference to FIG.

【0069】図3において、縦軸は膜厚検出電流ID
C、横軸は感光体膜厚dを表す。曲線D・Eは膜厚検出
時の帯電電位Vdptが−700V、−1500Vの時
のものをそれぞれ表している。
In FIG. 3, the vertical axis represents the film thickness detection current ID.
C, the horizontal axis represents the photoconductor film thickness d. Curves D and E respectively represent those when the charging potential Vdpt during film thickness detection is -700V and -1500V.

【0070】ここで、感光体の膜厚が15μm〜25μ
mまで変化するときの検出電流値の差分は、 曲線D(Vdpt=−700V)の場合は 22.9μA−15.0μA=7.9μA となり、 曲線E(Vdpt=−1500V)の場合は 49.1μA−32.2μA=16.9μA となる。
Here, the film thickness of the photoconductor is 15 μm to 25 μm.
The difference in the detected current value when changing to m is: 22.9 μA-15.0 μA = 7.9 μA in the case of the curve D (Vdpt = −700 V), and 49.C in the case of the curve E (Vdpt = −1500 V). 1 μA-32.2 μA = 16.9 μA.

【0071】電流検出抵抗値が10kΩであれば、抵抗
により検出される電圧の差分は各々 790mV(Vdpt=−700V時)、 1690mV(Vdpt=−1500V時) となる。
If the current detection resistance value is 10 kΩ, the difference between the voltages detected by the resistors is 790 mV (when Vdpt = −700 V) and 1690 mV (when Vdpt = −1500 V).

【0072】例えば、この検出電圧をサンプリング間隔
50mVのA/D変換回路12で変換すると、膜厚10
μmあたりのステップ数は、 Vdpt=−700V時、 790mV÷50mV=15.8ステップ Vdpt=−1500V時、 1690mV÷50mV=33.8ステップ となる。
For example, when the detected voltage is converted by the A / D conversion circuit 12 having a sampling interval of 50 mV, the film thickness is 10
The number of steps per μm is: Vdpt = −700V, 790mV ÷ 50mV = 15.8 steps Vdpt = −1500V, 1690mV ÷ 50mV = 33.8 steps

【0073】つまり、膜厚検出時の帯電電圧を−150
0Vと大きく定めることによって、膜厚検出の精度を向
上させることが可能となる。
That is, the charging voltage when detecting the film thickness is set to -150.
By setting a large value of 0 V, it is possible to improve the accuracy of film thickness detection.

【0074】以上、感光体の膜厚検知時に感光体を帯電
する電圧Vdpt.を、画像形成時の帯電電圧Vdより
大きな値に定めることにより膜厚検知の精度を向上する
ことが可能となった。
As described above, the voltage Vdpt. It has become possible to improve the accuracy of film thickness detection by setting a value larger than the charging voltage Vd during image formation.

【0075】〈実施例3〉(図4・図5) 本実施例は前述した実施例1において、感光体膜厚検知
時における帯電ローラ2に対する印加電圧制御を次のよ
うにした。他は実施例1と同様である。
<Embodiment 3> (FIGS. 4 and 5) In this embodiment, the applied voltage control to the charging roller 2 at the time of detecting the photoconductor film thickness in the above-described Embodiment 1 is performed as follows. Others are the same as in the first embodiment.

【0076】A)感光体膜厚検知時 最初に周波数1000Hz、Vpp=1800Vの交流
電圧(除電バイアス)を感光ドラム1回転以上印加し、
感光ドラムの表面電位を0Vに除電する。
A) At the time of detecting the photoconductor film thickness: First, an alternating voltage (static elimination bias) having a frequency of 1000 Hz and Vpp = 1800 V is applied for one rotation of the photosensitive drum or more,
The surface potential of the photosensitive drum is eliminated to 0V.

【0077】次に、周波数1000Hz、Vpp=18
00Vの交流電圧に直流電圧を重畳した電圧(感光体膜
厚検知時帯電バイアス)を印加した状態で感光ドラム1
を3周以上回転させ、感光ドラム表面を均一に帯電す
る。
Next, frequency 1000 Hz, Vpp = 18
The photosensitive drum 1 is applied with a voltage (charging bias when the photoconductor film thickness is detected) in which a DC voltage is superimposed on an AC voltage of 00V.
Is rotated three times or more to uniformly charge the surface of the photosensitive drum.

【0078】ここで、交番電圧に重畳される直流電圧値
は、画像形成装置本体内の温度に応じ定まり、その関係
は図4に示す通りである。横軸は本体内温度、縦軸は帯
電電圧Vdpt(=印加する直流電圧値)を表す。画像
形成装置本体内の温度は温度センサー11により測定す
る。
Here, the DC voltage value superimposed on the alternating voltage is determined according to the temperature inside the image forming apparatus main body, and the relationship is as shown in FIG. The horizontal axis represents the temperature inside the main body, and the vertical axis represents the charging voltage Vdpt (= DC voltage value to be applied). The temperature inside the image forming apparatus main body is measured by the temperature sensor 11.

【0079】その後、周波数1000Hz、Vpp=1
800Vの交流電圧を印加した状態で感光ドラム1を回
転させ感光ドラム表面を再び除電する。
Thereafter, frequency 1000 Hz, Vpp = 1
The photosensitive drum 1 is rotated while the AC voltage of 800 V is applied, and the surface of the photosensitive drum is discharged again.

【0080】この時に感光ドラム1に流れる直流電流I
DCが膜厚検出電流となる。
At this time, the direct current I flowing through the photosensitive drum 1
DC becomes the film thickness detection current.

【0081】検出電流を10kΩの検出抵抗で電圧に変
換した後、10倍の増幅回路10で電圧値を増幅し、得
られた電圧値をAD変換回路でサンプリングし膜厚を判
断する。
After the detection current is converted into a voltage by the detection resistance of 10 kΩ, the voltage value is amplified by the 10 times amplification circuit 10, and the obtained voltage value is sampled by the AD conversion circuit to judge the film thickness.

【0082】B)従来例との比較 図5により本実施例と従来例との比較を説明する。B) Comparison with Conventional Example A comparison between this embodiment and the conventional example will be described with reference to FIG.

【0083】図5において、縦軸は増幅回路10で増幅
後の検出電圧、横軸は感光体膜厚を表す。
In FIG. 5, the vertical axis represents the detected voltage after being amplified by the amplifier circuit 10, and the horizontal axis represents the photoconductor film thickness.

【0084】帯電電位Vdptを−700Vに固定した
場合、画像形成装置本体内温度を10℃〜30℃まで変
化させると、膜厚と電流の関係は、曲線L〜曲線Hまで
変化してしまう。その主な理由は電圧の増幅回路10の
温度特性が大きいためである。
When the charging potential Vdpt is fixed at -700 V and the temperature inside the image forming apparatus main body is changed from 10 ° C. to 30 ° C., the relationship between the film thickness and the current changes from curve L to curve H. The main reason is that the temperature characteristic of the voltage amplifier circuit 10 is large.

【0085】この温度特性を相殺するために、上述のご
とく画像形成装置本体内温度に対して帯電電圧の制御を
行う。
In order to cancel this temperature characteristic, the charging voltage is controlled with respect to the internal temperature of the image forming apparatus main body as described above.

【0086】上述の制御後の膜厚と検出電圧の関係はあ
らゆる温度下で図中曲線Mに収束し、その結果、膜厚の
検出精度が向上する。
The relationship between the film thickness after the above control and the detection voltage converges to the curve M in the figure under all temperatures, and as a result, the film thickness detection accuracy is improved.

【0087】以上、感光体の膜厚検知時に感光体を帯電
する電圧Vdpt.を画像形成装置本体内の温度に応じ
制御することにより、感光体膜厚検知の精度を向上する
ことが可能となった。
As described above, the voltage Vdpt. It is possible to improve the accuracy of detecting the photoconductor film thickness by controlling the temperature of the photoconductor according to the temperature inside the main body of the image forming apparatus.

【0088】また、本実施例では検出電圧値が温度に依
存し変化した場合について説明したが、湿度或は温度・
湿度両方に依存し変化するような場合には、帯電電圧値
の制御は湿度或は温度・湿度に応じて行なう。
In this embodiment, the case where the detected voltage value changes depending on the temperature has been described.
When the charging voltage value changes depending on both humidity, the charging voltage value is controlled according to humidity or temperature / humidity.

【0089】以上の各実施例においては、像担持体の帯
電装置2(帯電部材)は接触帯電ローラであるが、ロー
ラ型以外のブレード型、ブラシ型、ロッド型等の他の形
態の接触帯電部材であってもよいし、コロナ帯電装置等
の非接触式の帯電手段であってもよい。
In each of the above embodiments, the charging device 2 (charging member) for the image bearing member is a contact charging roller, but other types of contact charging such as blade type, brush type, rod type other than roller type are used. It may be a member or a non-contact type charging means such as a corona charging device.

【0090】また画像形成装置は電子写真プロセセスの
ものに限らず、静電記録誘電体を像担持体とする静電記
録プロセスのもの等にも本発明は適用できる。
The image forming apparatus is not limited to the electrophotographic process type, but the present invention can be applied to an electrostatic recording process using an electrostatic recording dielectric as an image carrier.

【0091】プロセスカートリッジPは少なくとも像担
持体を含むもので、他に包含させるプロセス機器の種類
・組み合わせは任意である。
The process cartridge P contains at least an image bearing member, and the type and combination of other process devices to be included are arbitrary.

【0092】画像形成装置はプロセスカートリッジ着脱
式でなくともよいことは勿論である。
It goes without saying that the image forming apparatus does not have to be the process cartridge detachable type.

【0093】[0093]

【発明の効果】以上のように本発明によれば、帯電部材
で像担持体を帯電或は除電する際に像担持体を流れる電
流を検知し、その電流信号より像担持体の膜厚を判断す
る膜厚判断手段を有する画像形成装置について、前述の
従来装置の問題点を解消して、像担持体の膜厚を正確に
検知すること、膜厚検知の精度を向上することが可能で
あり、所期の目的がよく達成される。
As described above, according to the present invention, the current flowing through the image carrier is detected when the image carrier is charged or discharged by the charging member, and the film thickness of the image carrier is determined from the current signal. With respect to an image forming apparatus having a film thickness determination means for determining, it is possible to solve the above-mentioned problems of the conventional device, to accurately detect the film thickness of the image carrier, and to improve the accuracy of film thickness detection. Yes, the intended purpose is often achieved.

【図面の簡単な説明】[Brief description of drawings]

【図1】画像形成装置例の概略構成図FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus.

【図2】実施例1の装置における、膜厚検出電流と感光
体膜厚との関係図
FIG. 2 is a diagram showing a relationship between a film thickness detection current and a photoconductor film thickness in the apparatus of Example 1.

【図3】実施例2の装置における、膜厚検出電流と感光
体膜厚との関係図
FIG. 3 is a diagram showing the relationship between the film thickness detection current and the photoconductor film thickness in the apparatus of Example 2.

【図4】実施例3の装置における、装置本体内温度と帯
電電圧との関係図
FIG. 4 is a diagram showing the relationship between the temperature inside the apparatus body and the charging voltage in the apparatus of Example 3;

【図5】実施例3の装置における、膜厚検出電圧と感光
体膜厚との関係図
FIG. 5 is a diagram showing the relationship between the film thickness detection voltage and the photoconductor film thickness in the apparatus according to the third embodiment.

【符号の説明】[Explanation of symbols]

1 感光ドラム(像担持体) 2 ローラ帯電装置 3 現像装置 4 クリーニング装置 5 転写装置 6 定着装置 P プロセスカートリッジ R 電流検出抵抗 8 高圧電源 9 制御回路(CPU) 10 増幅回路 11 温度湿度センサー 12 A/D変換回路 1 Photosensitive Drum (Image Carrier) 2 Roller Charging Device 3 Developing Device 4 Cleaning Device 5 Transfer Device 6 Fixing Device P Process Cartridge R Current Detection Resistor 8 High Voltage Power Supply 9 Control Circuit (CPU) 10 Amplifying Circuit 11 Temperature / Humidity Sensor 12 A / D conversion circuit

Claims (9)

【特許請求の範囲】[Claims] 【請求項1】 帯電部材に電圧を印加し、被帯電体とし
ての像担持体を所定電位に帯電或は除電する手段と、像
担持体を帯電或は除電する際に像担持体を流れる電流信
号を検知する電流検知手段と、前記電流信号より像担持
体の膜厚を判断する膜厚判断手段を有する画像形成装置
において、像担持体に帯電を行う際に帯電部材に印加す
る電圧値は、画像形成時と膜厚判断時とで異なることを
特徴とする画像形成装置。
1. A means for applying a voltage to a charging member to charge or neutralize an image carrier as a member to be charged to a predetermined potential, and a current flowing through the image carrier when the image carrier is charged or neutralized. In an image forming apparatus having a current detection unit that detects a signal and a film thickness determination unit that determines the film thickness of the image carrier based on the current signal, the voltage value applied to the charging member when charging the image carrier is An image forming apparatus, which is different between when forming an image and when determining a film thickness.
【請求項2】 帯電部材に電圧を印加し、被帯電体とし
ての像担持体を所定電位に帯電或は除電する手段と、像
担持体を帯電或は除電する際に像担持体を流れる電流信
号を検知する電流検知手段と、前記電流信号より像担持
体の膜厚を判断する膜厚判断手段を有する画像形成装置
において、像担持体に帯電を行う際に帯電部材に印加す
る電圧の絶対値は、画像形成時の値よりも膜厚判断時の
値が大きいことを特徴とする画像形成装置。
2. A means for applying a voltage to a charging member to charge or neutralize an image carrier as a member to be charged to a predetermined potential, and a current flowing through the image carrier when the image carrier is charged or neutralized. In an image forming apparatus having a current detection unit that detects a signal and a film thickness determination unit that determines the film thickness of the image carrier from the current signal, the absolute voltage applied to the charging member when the image carrier is charged. The image forming apparatus is characterized in that the value at the time of film thickness determination is larger than the value at the time of image formation.
【請求項3】 画像形成時に像担持体に帯電を行う際に
帯電部材に印加される電圧値が可変制御されていること
を特徴とする請求項1または請求項2に記載の画像形成
装置。
3. The image forming apparatus according to claim 1, wherein the voltage value applied to the charging member when the image carrier is charged during image formation is variably controlled.
【請求項4】 膜厚判断時に像担持体に帯電を行う際に
帯電部材に印加される電圧値が可変制御されていること
を特徴とする請求項1または請求項2に記載の画像形成
装置。
4. The image forming apparatus according to claim 1, wherein the voltage value applied to the charging member when the image carrier is charged at the time of determining the film thickness is variably controlled. .
【請求項5】 画像形成時に像担持体に帯電を行う際に
帯電部材に印加される電圧値と、膜厚判断時に像担持体
に帯電を行う際に帯電部材に印加される電圧値とが各々
独立で可変制御されていることを特徴とする請求項1ま
たは請求項2に記載の画像形成装置。
5. A voltage value applied to the charging member when charging the image carrier during image formation and a voltage value applied to the charging member when charging the image carrier during film thickness determination. The image forming apparatus according to claim 1, wherein the image forming apparatus is independently and variably controlled.
【請求項6】 装置本体内の温度と湿度のどちらか一方
或は両方を検知する温度湿度検知手段と、前記温度湿度
検知手段の出力値に応じ帯電部材に印加される電圧値を
可変制御する手段とを有することを特徴とする請求項3
乃至請求項5の何れか1つに記載の画像形成装置。
6. A temperature / humidity detecting means for detecting one or both of temperature and humidity inside the apparatus main body, and variably controlling a voltage value applied to the charging member according to an output value of the temperature / humidity detecting means. And means.
The image forming apparatus according to claim 5.
【請求項7】 帯電部材が像担持体に当接することを特
徴とする請求項1乃至請求項6の何れか1つに記載の画
像形成装置。
7. The image forming apparatus according to claim 1, wherein the charging member is in contact with the image carrier.
【請求項8】 像担持体が電子写真感光体或は静電記録
誘電体であることを特徴とする請求項1乃至請求項7の
何れか1つに記載の画像形成装置。
8. The image forming apparatus according to claim 1, wherein the image bearing member is an electrophotographic photosensitive member or an electrostatic recording dielectric member.
【請求項9】 像担持体は画像形成装置本体に対して着
脱されるプロセスカートリッジに包含されていることを
特徴とする請求項1乃至請求項8の何れか1つに記載の
画像形成装置。
9. The image forming apparatus according to claim 1, wherein the image carrier is included in a process cartridge that is attached to and detached from a main body of the image forming apparatus.
JP7160011A 1995-06-02 1995-06-02 Image forming device Pending JPH08334956A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7160011A JPH08334956A (en) 1995-06-02 1995-06-02 Image forming device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7160011A JPH08334956A (en) 1995-06-02 1995-06-02 Image forming device

Publications (1)

Publication Number Publication Date
JPH08334956A true JPH08334956A (en) 1996-12-17

Family

ID=15706052

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7160011A Pending JPH08334956A (en) 1995-06-02 1995-06-02 Image forming device

Country Status (1)

Country Link
JP (1) JPH08334956A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006195143A (en) * 2005-01-13 2006-07-27 Ricoh Co Ltd Image forming apparatus
JP2006243357A (en) * 2005-03-03 2006-09-14 Fuji Xerox Co Ltd Image forming apparatus
JP2007218978A (en) * 2006-02-14 2007-08-30 Fuji Xerox Co Ltd Image forming apparatus
US7826754B2 (en) * 2005-12-21 2010-11-02 Fuji Xerox Co., Ltd. Image forming apparatus with thickness detecting unit and parameter setting unit
JP2017044957A (en) * 2015-08-28 2017-03-02 キヤノン株式会社 Image forming apparatus
US10606202B2 (en) 2017-11-13 2020-03-31 Ricoh Company, Ltd. Image forming apparatus to calculate film thicknesses of a photoconductor film of a photoconductor, image forming method, and non-transitory recording medium storing image forming program

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006195143A (en) * 2005-01-13 2006-07-27 Ricoh Co Ltd Image forming apparatus
JP2006243357A (en) * 2005-03-03 2006-09-14 Fuji Xerox Co Ltd Image forming apparatus
JP4720215B2 (en) * 2005-03-03 2011-07-13 富士ゼロックス株式会社 Image forming apparatus
US7826754B2 (en) * 2005-12-21 2010-11-02 Fuji Xerox Co., Ltd. Image forming apparatus with thickness detecting unit and parameter setting unit
US8135327B2 (en) 2005-12-21 2012-03-13 Fuji Xerox Co., Ltd. Image forming apparatus with thickness detecting unit
JP2007218978A (en) * 2006-02-14 2007-08-30 Fuji Xerox Co Ltd Image forming apparatus
US7532832B2 (en) * 2006-02-14 2009-05-12 Fuji Xerox Co., Ltd. Image forming apparatus and charge control method
JP2017044957A (en) * 2015-08-28 2017-03-02 キヤノン株式会社 Image forming apparatus
US10606202B2 (en) 2017-11-13 2020-03-31 Ricoh Company, Ltd. Image forming apparatus to calculate film thicknesses of a photoconductor film of a photoconductor, image forming method, and non-transitory recording medium storing image forming program

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