JP2001350309A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the color mixture of developer in a developing device by easily preventing an electrifier cartridge detached from an image forming station from being erroneously attached to another station, in an image forming device where each image forming station is provided with a magnetic brush electrifier, toner left after transfer is removed by cleaning simultaneous with developing and the magnetic brush electrifier is formed as a cartridge. SOLUTION: The electrifier cartridge of each image forming station is provided with a storage means, and information on the arrangement of the electrifier cartridge is previously stored in the storage means. When the electrifier cartridge is attached to an image forming device main body, the information on the arrangement of the electrifier cartridge is read out from the storage means of the attached electrifier cartridge and collated with information on the arrangement of the electrifier cartridge stored in the storage means of the device main body so as to judge the propriety of the attachment of the electrifier cartridge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for developing an electrostatic latent image formed on an image carrier corresponding to an image to be recorded with a developer and recording the image on paper or the like.

[0002]

2. Description of the Related Art Conventionally, many image forming apparatuses using an electrophotographic system or an electrostatic recording system have been proposed. The schematic configuration and operation will be described with reference to FIG.

In the image forming apparatus shown in FIG. 5, when a copy start signal is input, the photosensitive drum 1 is charged to a predetermined potential by a charger 3 and is placed on a document table 10. An original illumination lamp, a short focus lens array, and a CCD sensor form an integrated unit 9 for scanning the original G while irradiating the original with the original G, and the reflected light of the illumination scanning light from the original surface becomes short focus. An image is formed by the lens array and input to the CCD sensor.

The CCD sensor comprises a light receiving section, a transfer section, and an output section. In the CCD light receiving section, an optical signal is converted to a charge signal, and the transfer section sequentially transfers the signal to an output section in synchronization with a clock pulse, and outputs the signal. The unit converts the charge signal into a voltage signal, amplifies the signal, reduces the impedance, and outputs the signal. The obtained analog signal is subjected to well-known image processing, converted into a digital signal, and sent to a printer unit. The printer unit receives the above image signal and turns ON / OF.
The light L of the solid-state laser element which emits F light is exposed by a laser exposing means 2 which scans with a rotating polygon mirror rotating at a high speed, and an electrostatic latent image corresponding to a document image is formed on the surface of the photosensitive drum 1. .

[0005] The electrostatic latent image formed on the photosensitive drum 1 is
The toner is developed by a developing unit 4 using a two-component developer having toner particles and a magnetic carrier, and is visualized as a toner image.
The toner image thus formed on the photosensitive drum 1 is electrostatically transferred onto a recording material by the transfer device 7. Thereafter, the recording material is electrostatically separated from the transfer device 7 and conveyed to the fixing device 6, where the toner image is thermally fixed on the recording material, and an image fixed on the recording material is output.

After the transfer, the transfer residual toner remaining on the surface of the photosensitive drum 1 is removed by a cleaning device (drum cleaner) 5, and the residual charge is removed by exposure by a pre-exposure device 8. Be prepared for.

In recent years, as shown in FIG. 6, a cleaner-less apparatus which eliminates a drum cleaner and performs simultaneous development and cleaning by a developing unit 4 has appeared. Simultaneous development cleaning is a method in which transfer residual toner remaining on the photosensitive drum 1 after transfer is collected in the developing device 4 by a fogging bias at the time of development in the next and subsequent steps. As a result, the transfer residual toner is collected and used after the next process.
Waste toner can be eliminated. Further, there is a great advantage in terms of space due to the elimination of the drum cleaner, and the size of the apparatus can be greatly reduced.

In recent years, because of the advantages such as low ozone and low power consumption, a voltage is applied to the contact charging device, that is, the photosensitive drum of the member to be charged, as the charger 3 of the photosensitive drum 1 described above. 2. Description of the Related Art Apparatuses of a type for charging a photosensitive drum by contacting a charging member have been put to practical use.

As the contact charging member, a magnetic brush using conductive magnetic particles, a fur brush formed of conductive fibers in a brush shape, or a conductive rubber roller formed of conductive rubber in a roller shape is preferably used. Can be Among them, the magnetic brush charging method is particularly preferably used from the viewpoint of stability of charging contact.

In this magnetic brush charging device, the conductive magnetic particles are magnetically constrained directly on the magnet or on a support sleeve containing the magnet to form a magnetic brush on the magnetic particles and stop the magnetic brush. Alternatively, the photosensitive drum is charged through the magnetic particles by contacting the photosensitive drum while rotating and applying a voltage to the magnet or the support sleeve.

When such a contact charging member is combined with a photosensitive drum having a surface layer in which conductive fine particles are dispersed on an ordinary organic photosensitive member or an amorphous silicon photosensitive member, the charging bias applied to the contact charging member can be increased. It is possible to obtain on the surface of the photosensitive drum a charged potential substantially equal to the DC component of the above. Such a charging method is also called an injection charging method. If this injection charging method is used, the ozoneless and low power consumption type charging can be realized because the discharging phenomenon unlike when the charging of the photosensitive drum is performed using a corona charger is not used.

In recent years, as a configuration of a main body of a color electrophotographic apparatus, as shown in FIG. 1, photosensitive drums 1 (1a to 1a) are respectively provided for four colors of yellow, magenta, cyan, and black.
1d), charger 3 (3a-3d), developer 4 (4a-4
d) and the like, a tandem system has been developed in which four-color images are sequentially superimposed on paper in one pass. This method has an advantage that color recording can be performed at high speed.

In such an image forming apparatus, from the viewpoint of simplification of the structure, life of the consumable parts, and cost, a process cartridge having an integrated unit structure in which the consumable parts can be detached from the apparatus main body is used. Usually, the process cartridge includes a photoconductor, a charging unit, a developing unit, and the like, and is replaced with a proper life. According to the process cartridge system, the maintenance of the apparatus can be performed by the user himself without depending on a service person,
Operability can be remarkably improved.

Therefore, the process cartridge system is being widely used in image forming apparatuses. Since the process cartridge is frequently attached to and detached from the apparatus main body, a nonvolatile storage means such as an EEPROM is incorporated in the cartridge itself, for example, to improve the detection accuracy when a plurality of cartridges are used for one apparatus. It has also been proposed.

[0015]

By the way, in a cleaner-less tandem type image forming apparatus having a magnetic brush charger and simultaneous development and cleaning, the charger is configured as a single charger cartridge detachable from the apparatus main body. In this case, there is a problem that color mixing occurs.

That is, in the simultaneous development cleaning, the transfer residual toner on the photosensitive drum is once collected by a magnetic brush charger, the toner is charged and adjusted to the original charging polarity, then discharged to the photosensitive drum, and collected by the developing device. Therefore, if a charger cartridge removed from one station is mistakenly attached to another station, a different color from the attached charger cartridge is applied to the developing device via the photosensitive drum of the other station. The toner is mixed, and color mixture occurs in the toner in the developing device.

The problem of erroneous mounting of the removed charger cartridge to another station is likely to occur when a user who is not accustomed to exchanging process parts performs the operation without relying on a service person.

Conventionally, in order to avoid such a problem,
A method is adopted in which the shape of the charger cartridge is changed for each image forming station so that the charger cartridge cannot be mounted when the station is different. However, in this case, the shape of the charger cartridge must be changed for each station, and the advantage of making the charger into a cartridge is largely lost.

Accordingly, an object of the present invention is to provide an image forming apparatus in which each image forming station has a magnetic brush charger and performs simultaneous cleaning of transfer residual toner during development, and the magnetic brush charger is formed into a cartridge. It is another object of the present invention to provide an image forming apparatus capable of easily preventing a charger cartridge removed from a certain station from being erroneously mounted in another station, thereby preventing color mixture of a developer in a developing unit.

[0020]

The above object is achieved by an image forming apparatus according to the present invention. In summary, the present invention provides:
An image carrier, a contact charger for charging the image carrier, developing means for developing the electrostatic latent image formed on the image carrier to visualize it as a toner image, and a toner image on the image carrier A plurality of image forming stations having a transfer unit for transferring the toner image onto a recording medium. At each station, the transfer residual toner remaining on the image carrier due to the transfer of the toner image is transferred to the toner original by the contact charger. The image forming apparatus is configured to be charged to a polarity and to collect the charged toner by the developing unit, and the contact charger is configured in a charger cartridge detachably attached to an image forming apparatus main body at each station. In the apparatus, the charger cartridge has storage means for storing information on the arrangement of the charger cartridge, and the charger cartridge is mounted on the apparatus main body. Reading the information on the arrangement of the charger cartridge stored in the storage unit of the mounted charger cartridge, and reading the information on the arrangement of the charger cartridge stored in the storage unit of the apparatus body. The image forming apparatus is characterized in that collation is performed to determine whether or not the mounted charger cartridge is properly mounted.

According to the present invention, the information on the arrangement of the charger cartridges is information on the arrangement order of the stations to which the charger cartridges belong. Alternatively, the information on the arrangement of the charger cartridge is information on the color of the developer used in the developing unit of the station to which the charger cartridge belongs. The contact charger is a magnetic brush charger using conductive magnetic particles. The charging bias applied to the contact charger is a voltage obtained by superimposing an AC voltage on a DC voltage. The image carrier has a surface layer in which conductive fine particles are dispersed in a resin on a photosensitive layer. The recording medium is a recording material. Alternatively, the recording medium is an intermediate transfer member that is temporarily transferred before transferring the toner image on the image carrier to a recording material.

[0022]

Embodiments of the present invention will be described below in more detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the image forming apparatus of the present invention.

In the image forming apparatus shown in FIG. 1, the reader section 9 is the same as that of the conventional image forming apparatus shown in FIG.

As shown in FIG. 1, the present image forming apparatus forms first and second toner images of yellow (Y), magenta (M), cyan (C), and black (K) in the main body of the apparatus. , Third and fourth image forming stations (image forming units)
Pa, Pb, Pc, and Pd are arranged in tandem, and each station includes an electrophotographic photosensitive member on a drum as an image carrier, that is, photosensitive drums 1a, 1b, 1c, and 1d. Around each photosensitive drum 1a, 1b, 1c, 1d, a charger cartridge 30a, 3 of a magnetic brush charger is provided.
0b, 30c, 30d, exposure apparatuses 2a, 2b, 2c, 2
d, developing devices 4a, 4b, 4c, 4d, and transfer chargers (transfer blades) 74a, 74b, 74 constituting transfer device 7
c, 74d, etc. are arranged. In this example, the exposure devices 2a to 2d as the latent image forming means use an LED array writer head.

The charger cartridge 30 (30a-30)
d) shows that the components of the magnetic brush charger are
By being incorporated in (100a to 100c), each station is detachably attached to the image forming apparatus main body in each station.

As shown in FIG. 2, the magnetic brush charger 30 as a charger cartridge has a support sleeve 31 made of a non-magnetic member in a container 100, and a fixed magnet 33 is provided inside the support sleeve 31. The magnetic field supports the magnetic particles m as a contact charging member in the form of a brush on the surface of the sleeve 31 and adjusts the amount of the magnetic particles m by the regulating blade 32 provided at the upper end of the opening of the container 100. With the rotation of 32, the magnetic particles m are conveyed to the charging section facing the photosensitive drum 1.

The rotation of the supporting sleeve 31
The counter direction is a direction in which the opposing portion moves in the opposite direction to the rotation direction. By applying a charging voltage to the sleeve 31, electric charges are given from the magnetic particles to the surface of the photosensitive drum 1, and the photosensitive drum 1 is charged to a potential corresponding to the charging voltage. The higher the rotation speed, the better the uniformity of charging tends to be.

The magnetic particles used as the contact charging member of the charger 3 have an average particle diameter of 10 to 100 μm, a saturation magnetization of 20 to 250 emu / cm ³ , and a resistance of 10 ² to 10 ¹⁰ Ωc.
m is preferable, and considering that there is an insulation defect such as a pinhole in the photosensitive drum 1, it is 10 ⁶ Ωcm
The above are preferred. In order to improve the charging performance, it is better to use one having as small a resistance as possible. In this embodiment, the average particle diameter is 25 μm and the saturation magnetization is 200 emu / c.
Magnetic particles having m ³ and a resistance of 5 × 10 ⁶ Ωcm were used. These magnetic particles were formed by adjusting the resistance by subjecting the surface of the ferrite to oxidation and reduction treatments.

In the present embodiment, the magnetic brush made of magnetic particles was brought into contact with the surface of the photosensitive drum 1 and the nip width formed with the photosensitive drum 1 was adjusted to be approximately 6 mm.
In this state, by applying an alternating voltage of a rectangular wave having an amplitude of 700 V and a frequency of 1000 Hz to the support sleeve 32 with respect to a DC voltage of -600 V, good charging properties could be obtained.

In the present invention, a commonly used organic photoreceptor or the like can be used for the photosensitive drum 1. The organic photoreceptor has a surface layer having a resistance of 10 ⁹ to 10 ¹⁴ Ωcm. It is preferable to use a photoreceptor or an amorphous silicon photoreceptor, and when these are used, charge injection charging can be realized, which is effective in preventing ozone generation and reducing power consumption. In addition, the chargeability can be improved.

In this embodiment, a negatively chargeable organic photoreceptor is used.
A photosensitive drum was used in which the following first to fifth layers were provided in order from the bottom on an aluminum drum base having a diameter of 30 mm.

The first layer is an undercoat layer and is formed of an aluminum-based layer.
Provided to smooth out defects in the body, etc.
Electric layer. The second layer is a positive charge injection preventing layer,
Positive charge injected from the minium substrate charges the photoconductor surface
Plays a role in preventing the cancellation of the negative charge
10 with Milan resin and methoxymethylated nylon ⁶
A medium resistance layer with a thickness of 1μm, the resistance of which is adjusted to about Ωcm
It is.

The third layer is a charge generation layer, which is a layer having a thickness of about 0.3 μm in which a disazo pigment is dispersed in a resin, and generates positive and negative charge pairs upon exposure. 4th
The layer is a charge transport layer, and is made of a P-type semiconductor in which hydrazone is dispersed in a polycarbonate resin. Therefore, negative charges charged on the surface of the photoreceptor cannot move through this layer, and only positive charges generated in the charge generation layer can be transported to the surface of the photoreceptor.

The fifth layer is a charge injection layer, which is a coating layer of a material in which ultrafine SnO ₂ particles are dispersed as conductive fine particles in a binder of an insulating resin. Specifically, a coating liquid in which 70% by weight of ultra-fine SnO ₂ fine particles having a particle size of 0.03 μm, which has been reduced in resistance (conducted) by doping antimony which is a light-transmitting conductive filler, is dispersed in an insulating resin is used. It was prepared and applied to a thickness of 3 μm by a suitable coating method such as dipping coating method, spray coating method, roll coating method, and beam coating method to form a charge injection layer.

The surface resistance of the photosensitive drum 1 is 10 ¹³ Ωcm. By controlling the surface resistance in this way, the direct charging property of the photosensitive drum is improved, and a high-quality image can be obtained. The photosensitive drum is not limited to OPC,
It can also be realized with a Si drum, and can achieve higher durability.

The electrostatic latent image formed on the photosensitive drum 1 is developed by a developing device 4 (4a to 4d) and visualized as a toner image.

In general, the developing method is such that a non-magnetic toner is coated on a developing sleeve with a blade or the like, a magnetic toner is coated on the developing sleeve by a magnetic force, and the developing sleeve conveys the toner to a developing unit facing the photosensitive drum. A method in which the developing unit develops the toner in a non-contact state with the photosensitive drum (one-component non-contact developing method); a method in which the developing unit develops the toner in a state in contact with the photosensitive drum (one-component contact developing method); A two-component developer in which a non-magnetic toner and a magnetic carrier are mixed is carried on a developing sleeve by magnetic force, the developer is transported to the developing unit by the developing sleeve, and the developer is developed in a non-contact state with the photosensitive drum. The method is broadly classified into a method (two-component non-contact development method) and a method of developing a developer in contact with a photosensitive drum (two-component contact development method). The two-component contact developing method is frequently used from the viewpoint of high image quality and high stability.

FIG. 3 is a sectional view showing a developing device installed in the present image forming apparatus. In this embodiment, the developing device 4 (4a
4d) employs a two-component contact development method, more specifically, a two-component magnetic brush contact development method.

As shown in FIG. 3, the developing device 4 is provided with a developing sleeve 41, a magnet roller 43, developer stirring screws 43 and 44, and a developer regulating blade 45 in a developing container 46. It contains a two-component developer in which a toner and a magnetic carrier are mixed. Above the stirring screw 44, a toner replenishing chamber 49 containing replenished toner is provided.

The developing sleeve 41 is rotatably provided at an opening of a portion of the developing container 46 facing the photosensitive drum 1. The developing sleeve 41 is arranged so that a region closest to the photosensitive drum 1 is at least about 500 μm at the time of development, and can be developed in a state where the developer carried on the developing sleeve 41 is in contact with the photosensitive drum 1. It has become.

In this embodiment, the developer has an average particle size of 6
μm negatively chargeable non-magnetic toner, average particle size 20
1% by weight of titanium oxide having a thickness of 2.5 nm and a magnetic carrier having an average particle diameter of 35 μm having a saturation magnetization of 205 emu / cm ³ . The mixing ratio of the developer is
The weight ratio of the toner to the carrier was 6:94.

The magnet roller 42 is connected to the developing sleeve 4
1 and has five magnetic poles S1, N2, N3, S2, and N1 in the rotation direction of the developing sleeve. The regulating blade 45 is disposed vertically above the developing sleeve 41 at a predetermined interval. The stirring screws 43 and 44 are provided below the developing container 46 and separated by a partition wall 48.

Here, a step of developing the electrostatic latent image on the photosensitive drum 1 by a two-component magnetic brush developing method in the developing unit 4;
The circulation of the developer at that time will be described.

First, the two-component developer in the developing container 46 is
With the rotation of the developing sleeve 41, the regulating blade 45, which is vertically arranged with respect to the developing sleeve 41, is drawn up to the surface of the developing sleeve 41 by the magnetic pole N3 of the magnet roller 42 and transported from the N3 pole to the S2 pole to the N1 pole. Thus, the layer thickness is regulated, and a thin layer of the developer is formed on the developing sleeve 41. The developer formed in the thin layer reaches the developing area opposed to the photosensitive drum 1 by being transported by the developing sleeve 41, and is sprinkled on the surface of the developing sleeve 41 by the magnetic force of the magnetic pole S1, which is the main developing pole disposed there. Standing and formed on the magnetic brush.

The developer formed on the spike-shaped magnetic brush comes into contact with the surface of the photosensitive drum 1 to develop an electrostatic latent image on the photosensitive drum 1. As the sleeve 41 rotates, it is returned into the developing container 46, is separated from the surface of the developing sleeve 41 by the repelling magnetic field formed by the magnetic poles N 2 and N 3, and the developer is collected in the developing container 46.

At the time of development, a developing bias in which a DC voltage is superimposed on an AC voltage is applied to the developing sleeve 41 by a developing power supply 47. In this embodiment, the DC voltage is Vdc = −48
0V, AC voltage peak-to-peak voltage Vpp = 15
00V and frequency Vf = 3000 Hz. Generally, in the two-component developing method, when an AC voltage is applied, the developing efficiency increases,
Although the image has high quality, there is a risk that fogging is likely to occur. Therefore, normally, by providing a potential difference (fogging potential Vback) between the DC voltage applied to the developing sleeve 41 and the surface potential of the photosensitive drum 1, the toner adheres to the non-image area of the photosensitive drum 1 during development. That is, fogging is prevented.

The developer collected in the developing container 46 is conveyed along the longitudinal direction of the partition 48 by the stirring screw 43 and received by the stirring screw 44 through an opening (not shown) provided at one end of the partition 48. In the course of being transferred and conveyed by the stirring screw 44, the toner supplied from the toner supply chamber 49 is stirred to recover the toner concentration. The developer whose concentration has been recovered is returned to the developing sleeve 41 side through the opening at the other end of the partition wall 48 by the conveyance by the stirring screw 44.

The toner images of the respective colors obtained on the respective photosensitive drums 1 in FIG. 1 by the above-described development are transferred to the recording material by the transfer device 7. The transfer device 7 has an endless belt (transfer belt) 71 suspended between a driven roller 72 and a drive roller 73. Inside the transfer belt 71, the transfer blade 74 (74a to 74d) is provided with a photosensitive drum. 1 are installed opposite to each other. The transfer belt 71 includes a drive roller 7
The paper feed cassette 75 is rotated in the direction of the arrow by the
And transports the recording material P sequentially to each transfer section where the photosensitive drum 1 and the transfer blade 74 are opposed, in synchronization with the image formation on each photosensitive drum 1.

For the transfer belt 71, a polyimide resin film having a thickness of 75 μm was used. The material of the transfer belt 71 is not limited to a polyimide resin, but may be a polycarbonate resin, a polyethylene terephthalate resin, a polyvinylidene fluoride resin, a polyethylene phthalate resin, a polyetheretherketone resin, a polyethersulfone resin, a polyurethane resin, or the like. Plastic or fluorine-based or silicon-based rubber can be suitably used. The thickness is not limited to 75 μm, but is 25 to 2000 μm, preferably 50 to 150 μm.
Is preferred.

The transfer blade 74 presses the transfer belt 71 in the direction of the photosensitive drum 1 from the back surface. In this state, a transfer bias having a polarity opposite to that of the toner is applied from a transfer power supply (not shown). The upper recording material is charged from the back surface with a polarity opposite to that of the toner, and each color toner image on each photosensitive drum 1 is sequentially superimposed and transferred onto the recording material.

The transfer blade 74 has a resistance of 10 ⁵ to 10 ^7.
Ω was used. In the present embodiment, the transfer was performed by applying a transfer bias of +15 μA to the transfer blade 74 under constant current control.

The recording material onto which the four color toner images have been transferred is then separated from the transfer belt 71 and sent to the fixing device 6.
Then, the four color toner images are thermally fixed to form a full-color fixed image, and then discharged outside the image forming apparatus.

The untransferred toner remains on each of the photosensitive drums 1 on which the transfer has been completed. In many cases, the transfer residual toner includes both a negative toner having an original polarity and a positive toner having a polarity inverted by peeling discharge or the like during transfer. The transfer residual toner having the mixed polarity on each photosensitive drum 1 is conveyed to each magnetic brush charger 3 and taken in and mixed with the magnetic particles m in the charger, where all the polarity is negatively charged. It is discharged onto the photosensitive drum 1.

At this time, simply applying a DC voltage to the charger 3 does not sufficiently take in the toner into the charger, but applying an AC voltage facilitates taking in the toner into the charger. Will be The transfer residual toner discharged to the photosensitive drum 1 after being adjusted to the original negative polarity by the charger 3 is conveyed to the developing device 4 and collected in the developing device 4 by the fogging electric field during development. That is, simultaneous development and recovery are performed.

Simultaneous recovery of development includes charging, exposure, development, and image formation from the photosensitive drum 1 when the rotation direction length of the image formed on the photosensitive drum 1 is longer than the circumferential length of the photosensitive drum. Is performed simultaneously with the image forming process such as transfer of the image. As a result, the recovered transfer residual toner is used in the next and subsequent steps, so that waste toner can be eliminated. In addition, there is a great advantage in terms of space due to omitting the cleaning means for the photosensitive drum 1, and it is possible to greatly reduce the size of the image forming apparatus.

A major feature of the present invention is that the magnetic brush charger of each station is an independently replaceable charger cartridge 30, so that the charger cartridge mounted on the station is prevented from being erroneously mounted. As shown in FIG.
(101a to 101d) are provided, and information on the arrangement of the charger cartridge 30 is stored in advance in the storage means 101, so that when the charger cartridge is mounted on the apparatus main body, the mounting of the mounted charger cartridge is performed. Judgment of suitability was made.

The information on the arrangement of the charger cartridge includes information on the arrangement order of the stations to which the charger cartridge belongs, information on the color of the developer used in the developing means of the station to which the charger cartridge belongs, and the like.

The storage means 101 is not particularly limited as long as it can store and hold signal information in a rewritable manner. For example, an electrical storage means such as a RAM or a rewritable ROM, or a magnetic recording medium or a magnetic recording medium can be used. Magnetic storage means such as a bubble memory and a magneto-optical memory can be used. In the present embodiment, the storage unit 101 is a non-volatile storage unit, such as an NV, in terms of ease of handling and cost.
(Non Volatile) RAM was used.

A control method at the time of mounting the charger cartridge according to the present embodiment will be described with reference to the flowchart of FIG.

As shown in FIG. 4, first, when the user attaches the removed charging cartridge 30 to the main body of the image forming apparatus (step S1), the charging cartridge stored in the storage means 101 of the charging cartridge 30 is removed. The image forming apparatus main body reads the information (number) n of the arrangement order of the stations to which it belongs (S2), and then checks the information with the information N of the arrangement order of the stations stored in the storage medium in the apparatus main body (S3). If = N, the process proceeds to the image forming operation as it is (S4, S5), and if the charging cartridge mounting station is incorrect, a warning is issued to inform the user of the incorrect mounting (S4, S5). ).

For example, when the charger cartridge 30a, which is supposed to be mounted in the first station Pa, is mounted in the second station Pb, the image forming apparatus main body stores the storage means 101a of the mounted charger cartridge 100a.
The number n = 1 is read from the information on the arrangement order of the stations, and it is recognized that the number n = 2 in the arrangement order of the second station stored in the apparatus main body. Judge that it is mounted on the station.

If the user knows that the charger cartridge is erroneously mounted as described above, the user only has to mount the charger cartridge to a correct station again, thereby preventing color mixing of the toner in the developing device due to erroneous mounting. Can be prevented.

In the above, the present invention has been described with respect to an image forming apparatus for directly transferring toner images of a plurality of colors on a plurality of photosensitive drums to a recording material conveyed by a transfer belt, but the present invention is not limited to this. The present invention is also applied to an image forming apparatus in which a plurality of color toner images on a drum are temporarily transferred to an intermediate transfer member such as an intermediate transfer belt, and then collectively transferred to a recording material conveyed to the intermediate transfer member. And has a similar effect.

[0065]

As described above, according to the present invention,
Each image forming station has a contact charger such as a magnetic brush charger, and performs cleaning at the same time in each station, and the contact charger is a charger cartridge that is detachable from the apparatus main body. The charging device cartridge is provided with storage means for storing information relating to the arrangement of the charging device cartridge in advance, and when the charging device cartridge is mounted on the apparatus main body, the arrangement of the charging device cartridge is stored from the storage device of the mounted charging device cartridge. The information about the charger cartridge is read out and compared with the information on the arrangement of the charger cartridge stored in the storage means of the apparatus main body, and it is determined whether the charging cartridge is properly mounted. Can be easily prevented from being incorrectly mounted on another station, It is possible to prevent color mixing of the image device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a sectional view showing a charger cartridge of the magnetic brush charger installed in the image forming apparatus of FIG.

FIG. 3 is a sectional view showing a two-component magnetic brush developing device installed in the image forming apparatus of FIG. 1;

FIG. 4 is a flowchart showing a control method at the time of mounting the charger cartridge according to the embodiment of FIG. 1;

FIG. 5 is a cross-sectional view illustrating a conventional image forming apparatus.

FIG. 6 is a cross-sectional view illustrating another example of a conventional image forming apparatus.

[Explanation of symbols]

 1a to 1d Photosensitive drum 4a to 4d Developing device 30a to 30d Charger cartridge 31 Support sleeve 32 Regulator blade 33 Magnet roller 100 Container 101 Storage means m Magnetic particles

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 21/00 510 G03G 15/08 507B 2H077 F term (Reference) 2H003 AA11 BB11 CC04 DD03 EE16 2H027 DA27 DE07 ED03 EE08 EH10 FB04 GA30 GB01 HB16 HB17 2H030 AA04 AA07 AB02 AD02 AD16 BB34 BB44 2H068 AA05 CA37 FA02 2H071 BA03 BA13 BA32 DA06 DA32 2H077 AA37 AB02 AC02 AC16 AD06 AD13 EA03 EA14 EA15 EA16 FA19 GA00 GA12

Claims (8)

[Claims] An image bearing member; a contact charger for charging the image bearing member; developing means for developing an electrostatic latent image formed on the image bearing member to visualize the image as a toner image; A plurality of image forming stations having a transfer unit for transferring a toner image on a body to a recording medium are arranged, and at each station, the transfer residual toner remaining on the image carrier due to the transfer of the toner image is contact charged. The toner is charged to the original polarity by a charger, the charged toner is collected by the developing unit, and the contact charger is configured as a charger cartridge that can be attached to and detached from an image forming apparatus main body at each station. In the image forming apparatus described above, the charger cartridge has storage means for storing information relating to the arrangement of the charger cartridge, and the charger cartridge is provided in the device main body. When the charging device cartridge is mounted on the charging device cartridge, the device main body reads information on the arrangement of the charging device cartridge stored in the storing device of the mounted charging device cartridge, and stores the charging cartridge stored in the storage device of the device main body. An image forming apparatus that determines whether or not the mounted charger cartridge is suitable for mounting by comparing the information with information regarding the arrangement of the charger. 2. The image forming apparatus according to claim 1, wherein the information on the arrangement of the charger cartridge is information on an arrangement order of stations to which the charger cartridge belongs. 3. The information on the arrangement of the charger cartridge is information on a color of a developer used in a developing unit of a station to which the charger cartridge belongs.
Image forming apparatus. 4. The image forming apparatus according to claim 1, wherein the contact charger is a magnetic brush charger using conductive magnetic particles. 5. The charging bias applied to the contact charger is a voltage obtained by superimposing an AC voltage on a DC voltage.
The image forming apparatus according to any one of Items 1 to 4. 6. The image forming apparatus according to claim 1, wherein the image carrier has a surface layer in which conductive fine particles are dispersed in a resin on a photosensitive layer. 7. The recording medium according to claim 1, wherein the recording medium is a recording material.
The image forming apparatus according to any one of Items 1 to 6, 8. The image forming apparatus according to claim 1, wherein the recording medium is an intermediate transfer member that is temporarily transferred before transferring the toner image on the image carrier to a recording material. apparatus.