WO2000055693A1 - Appareil d'exposition blanche et dispositif de formation d'image - Google Patents

Appareil d'exposition blanche et dispositif de formation d'image Download PDF

Info

Publication number
WO2000055693A1
WO2000055693A1 PCT/JP2000/001566 JP0001566W WO0055693A1 WO 2000055693 A1 WO2000055693 A1 WO 2000055693A1 JP 0001566 W JP0001566 W JP 0001566W WO 0055693 A1 WO0055693 A1 WO 0055693A1
Authority
WO
WIPO (PCT)
Prior art keywords
blank exposure
exposure lamp
blank
photoreceptor
image
Prior art date
Application number
PCT/JP2000/001566
Other languages
English (en)
Japanese (ja)
Inventor
Hiroya Hirose
Original Assignee
Copyer Co., Ltd.
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 Copyer Co., Ltd. filed Critical Copyer Co., Ltd.
Priority to EP00909643A priority Critical patent/EP1170639A4/fr
Publication of WO2000055693A1 publication Critical patent/WO2000055693A1/fr

Links

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
    • G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
    • G03G15/045—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with means for charging or discharging distinct portions of the charge pattern on the recording material, e.g. for contrast enhancement or discharging non-image areas
    • G03G15/047—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with means for charging or discharging distinct portions of the charge pattern on the recording material, e.g. for contrast enhancement or discharging non-image areas for discharging non-image areas
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
    • G03G21/06—Eliminating residual charges from a reusable imaging member
    • G03G21/08—Eliminating residual charges from a reusable imaging member using optical radiation
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/04—Arrangements for exposing and producing an image
    • G03G2215/0429—Changing or enhancing the image
    • G03G2215/0431—Producing a clean non-image area, i.e. avoiding show-around effects
    • G03G2215/0448—Charge-erasing means for the non-image area
    • G03G2215/0451—Light-emitting array or panel
    • G03G2215/0453—Light-emitting diodes, i.e. LED-array

Definitions

  • the present invention relates to a blank exposure apparatus for removing unnecessary charges on a photoreceptor, which is used in an image forming apparatus such as a copying machine, a printer, and a facsimile that forms image information on a recording medium by an electrophotographic method. . Background art
  • an electrophotographic image forming apparatus that forms an image on a recording medium using a developer (toner) is widely used.
  • the surface of the photoconductor is uniformly charged before exposing the photoconductor to an image.
  • the photoconductor is rotating at a constant speed. At this time, if the size of the image area on the photoconductor is smaller than the size of the charged area of the photoconductor, electric charges remain in the non-image area on the photoconductor. Then, toner adheres to this residual charge, and consumes an excessive amount of toner.
  • a blank exposure device is provided at a peripheral portion of a photoconductor to erase unnecessary charges on the photoconductor.
  • This blank exposure apparatus is composed of a light emitting diode array (blank exposure lamp) in which a large number of light emitting diodes are arranged.
  • a predetermined light emitting diode By turning on a predetermined light emitting diode before developing the electrostatic latent image formed on the photoreceptor, the area of the photoreceptor irradiated with light from the light emitting diode (non-image area) is removed.
  • non-image area the area of the photoreceptor irradiated with light from the light emitting diode
  • toner is adhered only to selected portions of a document, and toner is not adhered to peripheral portions, such as so-called frame erasing or trimming, or composite copying in which selected portions of a plurality of documents are combined.
  • FIG. 10 is a diagram for explaining the black stripes, and shows a timing chart when an image is formed on one sheet of paper.
  • (A) shows the change in the potential of the photoreceptor surface
  • (b) shows the change in the voltage applied to the blank exposure lamp
  • (c) shows the change in the light amount of the blank exposure lamp.
  • FIG. 4D shows an actual image on paper.
  • Each timing chart in (c) is drawn corresponding to the position on the paper in Fig. 10 (d).
  • the following are the blank image, the black image, the half] ⁇ 1 image, the black image, the half] ⁇ 1 image, the black image, the black image, A solid white image is to be formed.
  • the photoreceptor rotates at a constant speed.
  • the blank exposure lamp is turned on for the non-image area on the photoreceptor and turned off for the image area.
  • the image area is irradiated with light carrying image information, thereby forming a potential distribution as shown in FIG. 10A, that is, an electrostatic latent image.
  • the electrostatic latent image is developed, and the toner image is fixed on the paper.
  • the present invention has been made in view of such a technical background, and an object of the present invention is to provide a blank exposure apparatus and an image forming apparatus capable of preventing black streaks from being generated at the leading end of a sheet. Is what you do.
  • a blank exposure apparatus includes a blank exposure apparatus that exposes a surface of a photoconductor to remove a charge on the surface to form a non-image area on the photoconductor.
  • a control means for adjusting the light amount of the blank exposure lamp gradually changes when the blank exposure lamp is switched from on to off.
  • a blank exposure apparatus comprises: A blank exposure lamp for removing a charge on the surface by exposing the surface of the body to form a non-image area on the photoconductor, and a constant voltage power supply for applying a constant voltage to the blank exposure lamp A switching unit for performing an on / off operation of a voltage applied to the blank exposure lamp; and the switching unit such that when switching the blank exposure lamp from lighting to extinguishing, the light amount of the blank exposure lamp gradually changes. And control means for controlling the following.
  • the present invention provides an image forming apparatus for forming image information on a recording medium by an electrophotographic method, wherein an electrostatic latent image formed on a photoconductor based on the image information is formed as a single component.
  • a developing device for developing with a developer; and a blank exposure lamp for exposing the surface of the photoreceptor to remove a charge on the surface to form a non-image area on the photoreceptor before performing development by the developing device.
  • a blank exposure apparatus having light amount adjusting means for adjusting the amount of light of the blank exposure lamp; and And control means for controlling the light amount adjusting means.
  • an image forming apparatus for forming image information on a recording medium by an electrophotographic method, wherein an electrostatic latent image formed on a photosensitive member based on the image information is collected.
  • a developing device for developing with a component developer, and a blank exposure for removing a charge on the surface by exposing the surface of the photoconductor before developing by the developing device to form a non-image area on the photoconductor.
  • a blank exposure apparatus having a lamp, a constant voltage power supply circuit for applying a constant voltage to the blank exposure lamp, and a switching unit for performing an on / off operation of a voltage applied to the blank exposure lamp; Control for controlling the switching means so that the amount of light of the blank exposure lamp gradually changes when the lamp is switched from on to off. It is characterized in that it comprises a stage, a. BRIEF DESCRIPTION OF THE FIGURES
  • FIG. 1 is a schematic configuration diagram of a main part of an image forming apparatus according to an embodiment of the present invention.
  • FIG. 2 is a schematic configuration diagram of a main charger and a blank exposure device of the image forming apparatus shown in FIG.
  • FIG. 3 is a schematic perspective view of a main charger of the image forming apparatus shown in FIG.
  • FIG. 4 is a schematic perspective view of the blank exposure apparatus of the image forming apparatus shown in FIG.
  • FIG. 5 is a schematic circuit diagram for explaining lighting control of a light emitting diode in the blank exposure apparatus shown in FIG.
  • FIG. 6 is a diagram illustrating the development characteristics of the image forming apparatus of the present embodiment.
  • Fig. 7 (a) is a diagram for explaining the change in the potential on the photoconductor corresponding to the leading edge of the paper
  • Fig. 7 (b) is the potential on the photoconductor corresponding to the trailing edge of the paper. It is a figure for explaining change of.
  • FIG. 8 is a diagram for explaining lighting control of a blank exposure lamp in an area on a photoconductor corresponding to a leading end of a sheet in the image forming apparatus of the present embodiment.
  • FIG. 9 is a diagram for explaining another example of the pulse voltage applied to the blank exposure lamp.
  • FIG. 10 is a diagram for explaining black streaks generated at the leading end of the sheet.
  • FIG. 1 is a schematic configuration diagram of a main part of an image forming apparatus according to an embodiment of the present invention
  • FIG. 2 is a schematic configuration diagram of a main charger and a blank exposure device of the image forming apparatus
  • FIG. FIG. 4 is a schematic perspective view of a main charger
  • FIG. 4 is a schematic perspective view of a blank exposure apparatus of the image forming apparatus
  • FIG. 5 is a schematic circuit diagram for explaining lighting control of a light emitting diode in the blank exposure apparatus.
  • the image forming apparatus includes a photoconductor 10, a main charger 20, a blank exposure device 30, a developing device 40, and a transfer charger 50. , A separation charger 60, a fixing device 70, a cleaner device 80, a pre-exposure device 90, and a controller 110 (see FIG. 5).
  • the photoconductor 10 is driven to rotate at a predetermined peripheral speed (process speed) in a clockwise direction as indicated by an arrow A.
  • the main charger 20 is exposed to the surface of the photoconductor 10 by corona discharge. As shown in FIG. 2 and FIG. 3, it has a wire 21, which is generally made of tungsten, a shield 22, a grid 23, and a power supply 24. A high voltage is applied to the wire 21 from the power supply 24.
  • the grid 23 has a large number of openings 23a formed by etching a member having a plate thickness of about 0.1 mm. Thereby, the photoconductor 10 can be uniformly charged.
  • the blank exposure device 30 removes the charge on the surface of the photoconductor 10 corresponding to the non-image area, and prevents extra developer (toner) from adhering to the photoconductor 10. .
  • a document illumination lamp (not shown) irradiates the document with scanning light and reads image information of the document. Then, the irradiation light L carrying the image information is guided to the photoreceptor 10 via an optical system (not shown), whereby an electrostatic latent image is formed on the photoreceptor 10.
  • the developing device 40 supplies the toner onto the photoreceptor 10 by rotating the sleeve 41 in the direction of arrow B. Thereby, the electrostatic latent image formed on the photoconductor 10 is visualized.
  • a one-component toner is used as the toner.
  • the transfer paper as the recording medium is moved in the direction of arrow C at the timing when the leading edge of the image on the photoreceptor 10 and the leading end of the transfer paper meet by the pair of registration rollers 12 1 and 12 2. Fed. Then, the toner on the surface of the photoconductor 10 is transferred to the transfer paper by the transfer charger 50.
  • the separation charger 60 removes static electricity from the back surface of the transfer paper on which the toner image has been transferred, and electrostatically separates the transfer paper from the photoconductor 10.
  • the transfer paper that has been electrostatically separated is conveyed in the direction of arrow D and sent to the fixing device 70.
  • the fixing device 70 fixes the toner image on the transfer paper by the heat pressure of the fixing roller pair 71, 72. As a result, the toner image is recorded semi-permanently. Thereafter, the transfer paper is discharged from the image forming apparatus main body to the outside.
  • the untransferred toner slightly remaining on the photoconductor 10 is collected from the photoconductor 10 by the cleaner 80. Then, the residual potential, which is a trace of the electrostatic latent image on the photoconductor 10, is erased by the pre-exposure device 90. Further, the control unit 110 controls the control of each unit of the image forming apparatus.
  • Blank exposure equipment 3 0 Plays two major roles: That is, by irradiating the entire area of the photoconductor 10 in the axial direction, the role of removing the electric charge in the non-image area on the photoconductor 10 corresponding to the margins at the leading edge and the trailing edge of the paper, and By irradiating a part of the body 10 in the axial direction, for example, the role of removing the electric charge in the non-image area on the photosensitive body 10 corresponding to the peripheral portion of the paper. As shown in FIGS.
  • the blank exposure apparatus 30 includes a light emitting diode array (blank exposure lamp) formed by arranging a large number of light emitting diodes 31 and a light emitting diode array.
  • a light emitting diode array (blank exposure lamp) formed by arranging a large number of light emitting diodes 31 and a light emitting diode array.
  • a switching element 36 such as a transistor that performs a switching operation.
  • the housing 33 is provided with an exposure width in order to perform exposure in which the boundary between the image area and the non-image area along the axial direction of the photoconductor 10, that is, the boundary between the non-static elimination part and the static elimination part is clear.
  • a partition wall 34 for regulation is provided.
  • a large number of openings 34 a are formed in the partition 34.
  • the exposure width of each light emitting diode 31 to the surface of the photoconductor 10 is regulated.
  • the control unit 110 By lighting a predetermined light emitting diode 31, the charge on the surface of the photoconductor 10 in the range of the exposure width is removed. The turning on / off timing of each light emitting diode 31 is controlled by the control unit 110.
  • the control unit 110 controls the switching element 36 so that the light amount of the light emitting diode 31 gradually changes. For example, the control unit 110 sends an ON / OFF signal to the switching element 36, converts the voltage output from the constant voltage power supply circuit 35 into a pulse voltage, and applies the pulse voltage to the light emitting diode 31.
  • the lighting control of the blank exposure lamp by the pulse voltage will be described later in detail.
  • Fig. 6 shows the development characteristics of the image forming apparatus.
  • the vertical axis represents the image density
  • the horizontal axis represents the potential on the surface of the photoconductor 10 (hereinafter also referred to as the photoconductor potential).
  • the image density is represented by Macbeth reflection density.
  • the image forming apparatus employs a developing method using one-component toner.
  • the photoreceptor potential when forming a normal image is between 150 V and 700 V.
  • the photoconductor potential is set to be about 700 V.
  • the photosensitive member potential is about 400 V.
  • the body potential is set to be about 150 V.
  • a so-called capri phenomenon occurs in an electrophotographic image forming apparatus.
  • This is a phenomenon caused by the fact that the photoconductor potential is in a positive Capri region of 150 V or more and 300 V or less as shown in FIG.
  • the photoreceptor potential falls below 150 V, it enters the region of the inverted capri as shown in FIG.
  • the toner of the opposite polarity existing in the developing device 40 that is, the so-called inverted toner, is developed, and the toner adheres to a region on the photoconductor 10 which is a non-image region in the image information. Will be.
  • FIG. 7A is a diagram for explaining a change in the potential potential in a region on the photoconductor 10 corresponding to the leading edge of the paper
  • FIG. 7B is a diagram on the photoconductor 10 corresponding to the trailing edge of the paper.
  • FIG. 7 is a diagram for explaining a change in potential in a region of FIG.
  • the vertical axis represents the potential potential (photoconductor potential) on the surface of the photoconductor 10, and the horizontal axis represents time (or the position along the rotation direction of the photoconductor 10). ). Further, this photoconductor potential is after exposure with the irradiation light L.
  • the blank exposure lamp is switched from on to off.
  • the area irradiated with the light from the blank exposure lamp becomes a blank area, and the area not irradiated becomes an image area.
  • a sharp change in the photoreceptor potential occurs at the boundary between the margin and the image area adjacent thereto, and at this time, a transient falling and rising phenomenon occurs, and potential edges E,, E, are formed. Is done.
  • the image area is irradiated with irradiation light L carrying image information.
  • this irradiation light L contains image information that is all white. Shall be
  • the photosensitive member potential V SL of the margin portion is Ri about 5 0 V
  • photoreceptor potential VL of the image area of the base evening white is about 1 5 0 V.
  • the photoconductor potential on the margin decreases from V SL (about 50 V) to about 0 V by the potential edge E
  • photoreceptor potential of the image area side of the base evening white you increase from V L (about 1 5 0 V) by the potential edge E 2 to about 2 0 0 V. Therefore, as shown in FIG. 6, the portion where the potential edge is formed has a potential at which the phenomenon of inverted Capri becomes remarkable.
  • the photoreceptor 10 starts moving immediately after passing through the charging area X of the main charger 20. Receive static electricity.
  • the photoconductor 10 has already obtained a sufficient amount of light by the blank exposure lamp in the exposure area Y of the blank exposure device 30, so the potential potential on the surface of the photoconductor 10 is There will be a sharp change at the boundary between region X and region Y.
  • the photoconductor 10 cannot obtain a sufficient amount of light by the blank exposure lamp downstream of the area Y, and the charge of the photoconductor 10 is reduced. Some parts are not completely removed.
  • FIG. 8 (a) shows the ideal photoconductor potential change
  • Fig. 8 (b) shows the ideal blank exposure lamp light intensity change
  • Fig. 8 (c) applies to the blank exposure lamp.
  • FIG. 8D is a diagram for explaining the pulse voltage
  • FIG. 8D is a diagram showing a specific example of the pulse voltage applied to the blank exposure lamp.
  • FIG. 8 (a) the formation of the potential edge may be suppressed by gradually changing the photoconductor potential.
  • the blank exposure apparatus 30 using the light emitting diode 31 employs an inexpensive constant voltage power supply circuit 35 which can easily obtain a required light quantity and is inexpensive. Therefore, it is easy to gradually change the light amount of the blank exposure lamp by providing a constant current circuit instead of the constant voltage power supply circuit 35, or by separately providing a dimmer.
  • these methods are costly.
  • a switching element 36 for turning on and off the voltage applied to the blank exposure lamp is provided, and the control unit 110 turns the blank exposure lamp on from off.
  • the switching element 36 is controlled to generate one or a plurality of pulse voltages, for example, as shown in FIG.
  • FIG. 8 (b) the light amount of the blank exposure lamp substantially falls gradually, and therefore, as shown in FIG. 8 (a), the photoconductor potential also changes gradually and becomes steep. The formation of the potential edge can be suppressed.
  • the pulse voltage shown in FIG. 8D is actually applied to the blank exposure lamp.
  • This pulse voltage is anomalous from ON to OFF for 6 ms, ON for 4 ms, OFF for 4 ms, ON for 2 ms, and then completely off.
  • the present inventors have determined that the pulse condition is such that when the blank exposure lamp is switched from on to off, the light amount of the blank exposure lamp is reduced by 10 to 90% in 80 to 100 milliseconds. Was set as a goal.
  • the light quantity of the conventional blank exposure lamp was reduced by 10 to 90% within 20 ms or less.
  • Fig. 9 shows another example of the pulse voltage applied to the blank exposure lamp.
  • pulse interval 1 ⁇ , ⁇ 2, ⁇ 3 can be used stepwise short Kushida pulse voltage.
  • a pulse voltage having a constant duty ratio Z (+ t 2 )
  • the off-state time t, and the on-state time t 2 «t,) are different.
  • This duty ratio may be changed stepwise.
  • the pulse voltage shown in FIG. 9 (c) is obtained by increasing the number of pulses from that shown in FIG. 9 (a).
  • a switching element for performing an on / off operation of the constant voltage power supply circuit is provided, and the control unit controls the switching element when switching the blank exposure lamp from on to off, and controls one or more
  • the control unit controls the switching element when switching the blank exposure lamp from on to off, and controls one or more
  • the photoconductor potential also changes slowly, The formation of steep potential edges can be suppressed, and the occurrence of black streaks at the leading edge of the paper can be suppressed.
  • the constant voltage power supply circuit is used as it is without using an expensive constant current power supply circuit, the advantage is that the cost is low and the control is relatively easy.
  • a constant current power supply circuit may be used instead of the constant voltage power supply circuit.
  • the light intensity of the blank exposure lamp may be changed by using a light control device.
  • the blank exposure apparatus of the present invention is provided with switching means for performing on / off operation of the constant voltage power supply circuit, and the control means controls the switching means when switching the blank exposure lamp from on to off, For example, by generating one or a plurality of pulse voltages and applying them to the blank exposure lamp, the light amount of the blank exposure lamp can be made to gradually fall. For this reason, the potential of the photoconductor changes gradually, so that the formation of a steep potential edge can be suppressed, and the occurrence of black streaks at the leading edge of the paper can be suppressed. Therefore, the blank exposure apparatus according to the present invention can be used in an image forming apparatus that forms image information on a recording medium by an electrophotographic method.
  • the image forming apparatus of the present invention includes the above-mentioned blank exposure device, it is also possible to suppress the occurrence of black streaks at the leading edge of the paper. Machine, pudding, fax, etc.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Fax Reproducing Arrangements (AREA)

Abstract

L'invention concerne un appareil d'exposition blanche ne provoquant pas l'apparition de raies noires sur la face avant d'une forme. Ledit appareil sert à former une zone de non-image sur un corps photosensible par exposition de la surface du corps photosensible à la lumière de manière à en éliminer la charge. L'appareil d'exposition blanche comprend une lampe d'exposition blanche constituée d'un ensemble de diodes électroluminescentes (31), d'un circuit (35) d'alimentation électrique à tension constante destiné à appliquer une tension constante aux bornes des diodes électroluminescentes (31), et d'un élément (36) de commutation permettant le passage/blocage de la tension constante. L'unité (110) de commande sert à commander les éléments (36) de commutation lors de la mise sous tension de la lampe d'exposition blanche, et à générer une ou plusieurs tensions d'impulsion destinées à être appliquées à la lampe d'exposition blanche, ce qui permet de réduire graduellement l'intensité de la lumière émise par la lampe d'exposition blanche lors de sa mise hors tension. L'invention concerne également un dispositif de formation d'image.
PCT/JP2000/001566 1999-03-15 2000-03-15 Appareil d'exposition blanche et dispositif de formation d'image WO2000055693A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP00909643A EP1170639A4 (fr) 1999-03-15 2000-03-15 Appareil d'exposition blanche et dispositif de formation d'image

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP11/69240 1999-03-15
JP06924099A JP3374906B2 (ja) 1999-03-15 1999-03-15 ブランク露光装置及び画像形成装置

Publications (1)

Publication Number Publication Date
WO2000055693A1 true WO2000055693A1 (fr) 2000-09-21

Family

ID=13397044

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2000/001566 WO2000055693A1 (fr) 1999-03-15 2000-03-15 Appareil d'exposition blanche et dispositif de formation d'image

Country Status (3)

Country Link
EP (1) EP1170639A4 (fr)
JP (1) JP3374906B2 (fr)
WO (1) WO2000055693A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7395956B2 (ja) 2019-10-25 2023-12-12 株式会社リコー 画像形成装置、画像形成方法及びプログラム

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5857870U (ja) * 1981-10-15 1983-04-19 株式会社リコー 感光体の非画像領域電位消去装置
JPS59171969A (ja) * 1983-03-18 1984-09-28 Fuji Photo Film Co Ltd 電子写真装置
JPS6157977A (ja) * 1984-08-29 1986-03-25 Canon Inc 像形成装置
JPS63125962A (ja) * 1986-11-14 1988-05-30 Mita Ind Co Ltd 複写機
JPH01177584A (ja) * 1988-01-06 1989-07-13 Sanyo Electric Co Ltd 静電記録装置の画像形成方法
JPH07152294A (ja) * 1993-11-30 1995-06-16 Mita Ind Co Ltd 画像形成装置における前帯電・除電方法

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55121452A (en) * 1979-03-12 1980-09-18 Olympus Optical Co Ltd Electrophotographic apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5857870U (ja) * 1981-10-15 1983-04-19 株式会社リコー 感光体の非画像領域電位消去装置
JPS59171969A (ja) * 1983-03-18 1984-09-28 Fuji Photo Film Co Ltd 電子写真装置
JPS6157977A (ja) * 1984-08-29 1986-03-25 Canon Inc 像形成装置
JPS63125962A (ja) * 1986-11-14 1988-05-30 Mita Ind Co Ltd 複写機
JPH01177584A (ja) * 1988-01-06 1989-07-13 Sanyo Electric Co Ltd 静電記録装置の画像形成方法
JPH07152294A (ja) * 1993-11-30 1995-06-16 Mita Ind Co Ltd 画像形成装置における前帯電・除電方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP1170639A4 *

Also Published As

Publication number Publication date
EP1170639A1 (fr) 2002-01-09
JP3374906B2 (ja) 2003-02-10
JP2000267403A (ja) 2000-09-29
EP1170639A4 (fr) 2007-12-12

Similar Documents

Publication Publication Date Title
US6845222B2 (en) Image forming method and image forming apparatus for suppressing movement of developer onto the electrostatic latent image carrier when the voltages applied to the charging and developing devices are raised or lowered
US4761672A (en) Ramped developer biases
US5845172A (en) Image forming apparatus having rotatable charging brush with varying charging voltage
US7194226B2 (en) Image forming apparatus featuring an image bearing member charged by a charging means and a developer charge providing means
KR0178835B1 (ko) 전자사진프로세스에 따라서 화상을 형성하는 화상형성장치
WO2000055693A1 (fr) Appareil d'exposition blanche et dispositif de formation d'image
JPH05346715A (ja) 電子写真装置
US5412212A (en) Corona-charging apparatus and method
JPH1063050A (ja) 電子写真現像方式を用いた画像形成装置の画像濃度調整方法及び手段
JP2001350385A (ja) 画像形成装置
JPH0312671A (ja) 電子写真装置
JPH11190959A (ja) 画像形成装置
JP3777816B2 (ja) 画像形成装置
JPH0667518A (ja) 現像バイアス制御装置
KR100517511B1 (ko) 전자사진 형성장치의 대전롤러의 저항 감지방법 및 장치
JP2023136503A (ja) 画像形成装置
JP2005084630A (ja) 画像形成装置
JPH09146429A (ja) 電子写真装置
JP2001075316A (ja) 画像調整方法
KR100319842B1 (ko) 화상형성장치의코로나대전장치
JP2002006638A (ja) 画像形成装置
JPH05281881A (ja) 画像形成装置
JPH09297476A (ja) 画像形成装置ならびにこの画像形成装置に組み込まれる転写装置の制御方法
JPH04110960A (ja) 電子写真装置の帯電装置
JPH1172986A (ja) カラー印刷装置

Legal Events

Date Code Title Description
AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2000909643

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2000909643

Country of ref document: EP