JPH0473796B2 - - Google Patents
Info
- Publication number
- JPH0473796B2 JPH0473796B2 JP576884A JP576884A JPH0473796B2 JP H0473796 B2 JPH0473796 B2 JP H0473796B2 JP 576884 A JP576884 A JP 576884A JP 576884 A JP576884 A JP 576884A JP H0473796 B2 JPH0473796 B2 JP H0473796B2
- Authority
- JP
- Japan
- Prior art keywords
- copy paper
- power source
- humidity
- electrical resistance
- component
- 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.)
- Expired
Links
- 238000000926 separation method Methods 0.000 claims description 11
- 238000001514 detection method Methods 0.000 claims description 3
- 108091008695 photoreceptors Proteins 0.000 description 14
- 238000010586 diagram Methods 0.000 description 8
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000010355 oscillation Effects 0.000 description 3
- 230000003068 static effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000000700 radioactive tracer Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/65—Apparatus which relate to the handling of copy material
- G03G15/6532—Removing a copy sheet form a xerographic drum, band or plate
- G03G15/6535—Removing a copy sheet form a xerographic drum, band or plate using electrostatic means, e.g. a separating corona
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
Description
【発明の詳細な説明】
［技術分野］
本発明は、感光体上のトナー像が転写された転
写紙を分離チヤージヤによつて分離する画像形成
装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an image forming apparatus in which a separation charger separates a transfer sheet onto which a toner image on a photoreceptor has been transferred.
［従来技術］
一般に、静電写真式の画像形成装置では感光体
上にトナー像を形成したのち、感光体上のトナー
像を転写紙（以下、複写用紙という）に転写す
る。この転写時においては、複写用紙の背面から
転写チヤージヤによつてトナー像と逆極性の直流
コロナ放電を行なうことでトナー像を複写用紙に
電気的に吸着させており、その結果複写用紙が感
光体に密着する。[Prior Art] Generally, in an electrophotographic image forming apparatus, a toner image is formed on a photoreceptor, and then the toner image on the photoreceptor is transferred to a transfer paper (hereinafter referred to as copy paper). During this transfer, the toner image is electrically attracted to the copy paper by applying direct current corona discharge of opposite polarity to the toner image by a transfer charger from the back side of the copy paper, and as a result, the copy paper is attached to the photoreceptor. closely adhere to.
そこで、複写後の複写用紙を感光体より分離す
る必要があり、その一方法として、複写用紙の背
面から分離チヤージヤで交流コロナ放電を行なつ
て複写用紙を除電し、複写用紙がその自重と剛性
によつて感光体から分離するようにする方法が知
られている。 Therefore, it is necessary to separate the copy paper from the photoconductor after copying. One method for this is to perform alternating current corona discharge from the back of the copy paper using a separation charger to eliminate static electricity from the copy paper. A method is known in which the photoreceptor is separated from the photoreceptor by a method.
そして、分離された複写用紙は、定着器によつ
てトナー像がその表面に定着れ、その後排出トレ
イに排出される。 A toner image is fixed on the surface of the separated copy paper by a fixing device, and then the copy paper is discharged to a discharge tray.
ところが、複写用紙の電気抵抗が小さい場合、
交流コロナ放電によつて複写用紙に乗る電荷が少
なく、逆に電気抵抗が大きい場合には複写用紙に
乗る電荷が多い。 However, if the electrical resistance of copy paper is low,
There is little charge on the copy paper due to AC corona discharge, and conversely, when the electrical resistance is large, there is a lot of charge on the copy paper.
また、複写用紙はその相対湿度によつて電気抵
抗が大きく変化し、相対湿度が大きい場合は電気
抵抗が小さく、相対湿度が小さい場合は電気抵抗
が大きい。 Further, the electrical resistance of copy paper changes greatly depending on its relative humidity; when the relative humidity is high, the electrical resistance is low, and when the relative humidity is low, the electrical resistance is high.
一方、画像形成装置は環境が標準的な状態（例
えば気温26℃湿度60％RH）で各要素が正常に動
作するように調整されて出荷される。 On the other hand, image forming apparatuses are shipped under standard environmental conditions (for example, temperature 26 degrees Celsius humidity 60% RH) and each element is adjusted to operate normally.
このようなことから、上述のように交流コロナ
放電によつて複写用紙を分離する場合、従来次の
ような問題を生じていた。 For this reason, when copy sheets are separated by alternating current corona discharge as described above, the following problems have conventionally occurred.
すなわち、標準的な状態よりも多湿な環境にお
いては、複写用紙の電気抵抗が小さくなるため充
分な除電がなされず、しかも、複写用紙の剛性も
低下することから複写用紙が感光体より分離され
にくくなり、その結果分離失敗してジヤムを生じ
ることがある。 In other words, in an environment that is more humid than standard conditions, the electric resistance of copy paper becomes smaller, so that sufficient static electricity is not removed.Furthermore, the stiffness of copy paper also decreases, making it more difficult for copy paper to separate than the photoreceptor. As a result, separation may fail and jam may occur.
また、標準的な状態よりも低湿度な環境におい
ては、複写用紙の電気抵抗が大きくなるため除電
過多状態になり、その結果トナーと同極性の電荷
が複写用紙に乗るためトナーが感光体に再吸着さ
れ、転写不良を生じることもあつた。 Additionally, in an environment with lower humidity than standard conditions, the electrical resistance of the copy paper increases, resulting in excessive charge removal, and as a result, charges of the same polarity as the toner are placed on the copy paper, causing the toner to re-enter the photoreceptor. In some cases, the particles were adsorbed, resulting in poor transfer.
［目的］
本発明は、上述した従来技術の欠点を解消する
ためになされたものであり、複写用紙の電気抵抗
に応じて分離チヤージヤ用電源の出力を制御する
ことで分離失敗や転写不良を防止できる画像形成
装置を提供することを目的とする。[Purpose] The present invention has been made in order to solve the above-mentioned drawbacks of the conventional technology, and prevents failures in separation and transfer by controlling the output of the power source for the separation charger according to the electrical resistance of the copy paper. The purpose is to provide an image forming apparatus that can.
［構成］
以下、添付図面を参照しながら、本発明の実施
例を詳細に説明する。[Configuration] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
第１図は、本発明に係る画像形成装置の一実施
例を示している。この実施例では、前述したよう
な複写用紙の電気抵抗と湿度（相対湿度）の関係
に基づき、複写用紙の湿度を測定し、その測定結
果から電気抵抗を判別している。 FIG. 1 shows an embodiment of an image forming apparatus according to the present invention. In this embodiment, the humidity of the copy paper is measured based on the relationship between the electrical resistance and humidity (relative humidity) of the copy paper as described above, and the electrical resistance is determined from the measurement result.
同図において、１は感光体、２は感光体１の表
面を一様に帯電する帯電チヤージヤ、３は余分な
電荷を除去するトレーサ、４はコンタクトガラス
５に載置された原稿（図示略）の画像をスキヤン
して感光体１を露光し、その表面に静電潜像を形
成する光学系、および、６は感光体１上の静電潜
像をトナーで現像する現像器である。 In the figure, 1 is a photoconductor, 2 is a charger that uniformly charges the surface of the photoconductor 1, 3 is a tracer that removes excess charge, and 4 is a document placed on a contact glass 5 (not shown). An optical system scans an image of the photoreceptor 1 to expose the photoreceptor 1 to form an electrostatic latent image on the surface of the photoreceptor 1, and a developing device 6 develops the electrostatic latent image on the photoreceptor 1 with toner.
７は複写用紙PPを給紙するためのカセツト、
８はカセツト７の上部に位置するように筺体内に
取り付けられた湿度センサ、９は複写用紙PPを
カセツト７から送り出す給紙コロ、１０は複写用
紙PPを１枚ずつ分離して搬送する搬送ローラ対、
１１はガイド板、１２は複写用紙PPの先端と感
光体１上のトナー像の先端とを一致させるタイミ
ングで複写用紙PPを送り出すレジストローラ対、
１３はガイド板である。 7 is a cassette for feeding copy paper PP;
8 is a humidity sensor installed in the housing so as to be located above the cassette 7, 9 is a paper feed roller that feeds the copy paper PP from the cassette 7, and 10 is a transport roller that separates and conveys the copy paper PP one by one. versus,
11 is a guide plate; 12 is a pair of registration rollers that sends out the copy paper PP at the timing to match the leading edge of the copy paper PP with the leading edge of the toner image on the photoreceptor 1;
13 is a guide plate.
１４は複写用紙PPにトナー像を転写するため
の転写チヤージヤ、１５は転写後の複写用紙PP
を感光体１から分離させるための分離チヤージ
ヤ、１６は分離後の複写用紙PPを搬送する搬送
ベルト、１７は複写用紙PPを加熱圧着してトナ
ー像を定着したのち機外へ排出する定着器、１８
は複写用紙PPを蓄積しておく排出トレイ、およ
び、１９は感光体１上に残つているトナーを除去
するためのクリーナである。 14 is a transfer charger for transferring the toner image onto the copy paper PP, and 15 is the copy paper PP after transfer.
16 is a conveyor belt that conveys the separated copy paper PP, 17 is a fixing device that heats and presses the copy paper PP to fix the toner image and then discharges it from the machine. 18
1 is a discharge tray for storing copy paper PP, and 19 is a cleaner for removing toner remaining on the photoreceptor 1.
第２図は、分離チヤージヤ１５の電源を制御す
る制御系を例示している。 FIG. 2 illustrates a control system for controlling the power source of the separation charger 15. As shown in FIG.
同図において、湿度センサ８の検出信号SHは
増幅器２０を介して増幅されたのち制御部２１に
加えられる。制御部２１は受入した信号に基づい
て湿度に対応した制御信号SCを発生し、これを
高圧発生部２２に出力する。高圧発生部２２は、
加えられる制御信号SCに対応した交流電圧を発
生してこれを分離チヤージヤ１５に加える。な
お、高圧発生部２２の電源印加タイミングは、画
像形成装置の各部を所定のタイミングで制御する
本体制御部（図示略）から加えられるタイミング
信号STによつて制御される。 In the figure, a detection signal SH from a humidity sensor 8 is amplified via an amplifier 20 and then applied to a control section 21. The control section 21 generates a control signal SC corresponding to humidity based on the received signal, and outputs this to the high pressure generation section 22. The high pressure generation section 22 is
An alternating current voltage corresponding to the applied control signal SC is generated and applied to the separation charger 15. Note that the timing of power application to the high voltage generating section 22 is controlled by a timing signal ST applied from a main body control section (not shown) that controls each section of the image forming apparatus at a predetermined timing.
ところで、分離チヤージヤ１５による交流コロ
ナ放電で複写用紙PPを適正に除電するためには、
高圧発生部２２が発生する交流電源の＋成分と−
成分のエネルギーの比を一定にする必要がある。 By the way, in order to properly neutralize the copy paper PP with AC corona discharge by the separate charger 15,
The positive and negative components of the AC power source generated by the high voltage generator 22
It is necessary to keep the energy ratio of the components constant.
すなわち、第３図に示したように、＋成分の振
幅をAP、−成分の振幅をAMとして、周期ｔにお
いて＋成分が占める時間t1と−成分が占める時間
t2との比Ｋ（＝t1／t2）は一定にする必要がある。 That is, as shown in Figure 3, assuming that the amplitude of the + component is AP and the amplitude of the - component is AM, the time t 1 occupied by the + component and the time occupied by the - component in period t are
The ratio K (=t 1 /t 2 ) with t 2 needs to be constant.
このように＋成分と−成分のエネルギーの比を
一定に保ちつつ交流電源の交流成分のエネルギー
を変化させるためには、周期ｔを変化させればよ
い。 In this way, in order to change the energy of the alternating current component of the alternating current power supply while keeping the ratio of the energy of the positive component and negative component constant, it is sufficient to change the period t.
すなわち、周期ｔを小さくして交流電源の周波
数を高くすれば交流成分のエネルギーは小さくな
り、周期ｔを大きくして交流電源の周波数を低く
すれば交流成分のエネルギーは大きくなる。 That is, if the period t is decreased and the frequency of the AC power source is increased, the energy of the AC component will be decreased, and if the period t is increased and the frequency of the AC power source is decreased, the energy of the AC component will be increased.
前述したように、複写用紙PPが多湿な場合は
電気抵抗が小さくなつて交流コロナ放電特性が悪
くなり、低湿な場合は電気抵抗が大きくなつて除
電過多が起ることから、湿度（相対湿度）が低い
場合は交流電源の周波数を高くして交流成分のエ
ネルギーを小さくし、湿度が高い場合は交流電源
の周波数を低くして交流成分のエネルギーを大き
くするように、制御部２１で高圧発生部２２を制
御すればよい。 As mentioned above, when copy paper PP is humid, the electrical resistance decreases and the AC corona discharge characteristics deteriorate, and when the humidity is low, the electrical resistance increases and excessive static removal occurs, so humidity (relative humidity) When the humidity is low, the frequency of the AC power source is increased to reduce the energy of the AC component, and when the humidity is high, the frequency of the AC power source is lowered to increase the energy of the AC component. 22 may be controlled.
そこで、例えば湿度と交流電源の周波数との関
係を第４図に示したように設定すると、制御部２
１は簡単な関数発生器で実現できる。 Therefore, for example, if the relationship between humidity and the frequency of the AC power source is set as shown in FIG.
1 can be realized with a simple function generator.
第５図に高圧発生部２２の具体例を示す。 A specific example of the high pressure generating section 22 is shown in FIG.
同図において、モノマルチ発振器２２１はデユ
テイ比が一定（上述したＫ）のパルス信号SP（第
６図参照）を発生するものであり、その発振周波
数は制御信号SCによつて制御される。 In the figure, a monomulti oscillator 221 generates a pulse signal SP (see FIG. 6) with a constant duty ratio (K above), and its oscillation frequency is controlled by a control signal SC.
このモノマルチ発振器２２１の出力するパルス
信号SPは、インバータINV、トランジスタTr1，
Tr2およびトランスTFからなる電力増幅器２２
２によつて増幅され、この電力増幅器２２２の出
力信号が交流電源として分離チヤージヤ１５に印
加される。 The pulse signal SP output from the monomulti oscillator 221 is transmitted through the inverter INV, the transistor Tr 1 ,
Power amplifier 22 consisting of Tr 2 and transformer TF
2, and the output signal of this power amplifier 222 is applied to the separate charger 15 as an AC power source.
したがつて、制御信号SCによりパルス信号SP
の周波数が制御され、電力増幅器２２２の出力す
る交流電源の周波数が制御される。 Therefore, the control signal SC causes the pulse signal SP
The frequency of the AC power output from the power amplifier 222 is controlled.
なお、モノマルチ発振器２２１は第７図に示し
たようなタイマICで実現できる。この例はシグ
ネテイツクス社製のNE555を用いている。 Note that the monomulti oscillator 221 can be realized by a timer IC as shown in FIG. This example uses NE555 manufactured by Signetix.
このNE555は、上記した時間t1，t2を抵抗R1，
R2およびコンデンサC1で設定でき、その値は次
式のようになる。 This NE555 has resistance R 1 ,
It can be set by R 2 and capacitor C 1 , and its value is as follows.
t1＝ｋ（R1＋R2）C1 t2＝kR2C1 ただし、ｋは定数である。 t 1 =k(R 1 +R 2 )C 1 t 2 =kR 2 C 1 However, k is a constant.
また、その発振周波数は制御信号SCの電圧値
で制御でき、この制御電圧が大きい程発振周波数
が大きい。 Further, the oscillation frequency can be controlled by the voltage value of the control signal SC, and the larger the control voltage, the higher the oscillation frequency.
ところで、以上述べた実施例では特に分離不良
や転写不良の大きな原因となつている複写用紙
PPの湿度を測定し、湿度と電気抵抗の関係から
交流電源の周波数を制御しているが、複写用紙
PPの電気抵抗を変える要素以外にも温度や複写
用紙PPの放置時間（吸湿量の経時変化）があり、
これらの測定値に基づいて交流電源の周波数を制
御するようにもできる。また、これらの複数の要
素を組み合わせてもよい。 By the way, in the above-mentioned embodiments, copy paper is a major cause of poor separation and poor transfer.
The humidity of PP is measured and the frequency of the AC power source is controlled based on the relationship between humidity and electrical resistance, but copy paper
In addition to the factors that change the electrical resistance of PP, there are other factors such as temperature and the time the copy paper PP is left standing (changes in moisture absorption over time).
It is also possible to control the frequency of the AC power source based on these measured values. Further, a plurality of these elements may be combined.
なお、当然のことながら、紙種が違うと電気抵
抗が違うため、複写用紙PPの紙種によつて交流
電源の周波数を制御してもよい。 Note that, as a matter of course, different types of paper have different electrical resistances, so the frequency of the AC power source may be controlled depending on the type of copy paper PP.
また、上述の実施例でも従来装置と同様に、高
圧発生部２２の出力する交流電源に直流オフセツ
ト電圧を加える。これにより、分離後の複写用紙
PP上にトナーを固定しておくことができる。 Also, in the above-described embodiment, a DC offset voltage is applied to the AC power output from the high voltage generator 22, as in the conventional device. This allows the copy paper to be separated after separation.
Toner can be fixed on PP.
［効果］
以上説明したように、本発明によれば複写用紙
の電気抵抗に基づいて分離チヤージヤ用電源の出
力（交流成分）を制御しているから、複写用紙を
確実に分離でき、また転写不良を防止できるとい
う利点を得る。[Effects] As explained above, according to the present invention, since the output (AC component) of the separation charger power source is controlled based on the electrical resistance of the copy paper, the copy paper can be reliably separated and transfer defects can be avoided. This has the advantage of being able to prevent
第１図は本発明に係る画像形成装置の一実施例
を示す構成図、第２図は分離チヤージヤ用電源系
を例示したブロツク図、第３図は交流電源を示す
波形図、第４図は湿度と交流電源の周波数との関
係を例示したグラフ図、第５図は高圧発生部の具
体的回路を例示したブロツク図、第６図はモノマ
ルチ発振器の出力信号を例示した波形図、第７図
はモノマルチ発振器の構成例を示したブロツク図
である。
８……湿度センサ、２０……増幅器、２１……
制御部、２２……発圧発生部、２２１……モノマ
ルチ発振器、２２２……電力増幅器、INV……
インバータ、Tr1，Tr2……トランジスタ、TF…
…トランス。
Fig. 1 is a block diagram showing an embodiment of an image forming apparatus according to the present invention, Fig. 2 is a block diagram illustrating a power supply system for a separate charger, Fig. 3 is a waveform diagram showing an AC power supply, and Fig. 4 is a waveform diagram showing an AC power supply system. A graph diagram illustrating the relationship between humidity and the frequency of an AC power source, Figure 5 is a block diagram illustrating a specific circuit of the high voltage generation section, Figure 6 is a waveform diagram illustrating the output signal of a monomulti oscillator, and Figure 7 The figure is a block diagram showing an example of the configuration of a monomulti oscillator. 8...Humidity sensor, 20...Amplifier, 21...
Control unit, 22... Voltage generation unit, 221... Mono multi oscillator, 222... Power amplifier, INV...
Inverter, Tr 1 , Tr 2 ...Transistor, TF...
…Trance.
Claims (1)
離チヤージヤによつて分離する画像形成装置にお
いて、転写紙の電気抵抗を検出する検出手段と、
＋成分と−成分のエネルギーの比が一定値に設定
された交流電源と、上記検出手段の出力に対応し
た周波数に、上記交流電源を制御する周波数制御
手段を備え、上記交流電源の出力を分離チヤージ
ヤに印加することを特徴とした画像形成装置。1. In an image forming apparatus in which a transfer paper on which a toner image on a photoconductor has been transferred is separated by a separation charger, a detection means for detecting electrical resistance of the transfer paper;
An AC power source in which the ratio of the energy of the + component to the - component is set to a constant value, and a frequency control means for controlling the AC power source at a frequency corresponding to the output of the detection means, and the output of the AC power source is separated. An image forming apparatus characterized by applying a charge to a charger.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP576884A JPS60150070A (en) | 1984-01-18 | 1984-01-18 | Copying machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP576884A JPS60150070A (en) | 1984-01-18 | 1984-01-18 | Copying machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60150070A JPS60150070A (en) | 1985-08-07 |
| JPH0473796B2 true JPH0473796B2 (en) | 1992-11-24 |
Family
ID=11620297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP576884A Granted JPS60150070A (en) | 1984-01-18 | 1984-01-18 | Copying machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60150070A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0283566A (en) * | 1988-09-20 | 1990-03-23 | Konica Corp | Image forming device |
-
1984
- 1984-01-18 JP JP576884A patent/JPS60150070A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60150070A (en) | 1985-08-07 |
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