JPH02257182A - Recording device - Google Patents

Abstract

PURPOSE:To prevent magnetic latent image forming efficiency from lowering by providing a cleaning means for cleaning a 1st image fixed by a fixing means before a magnetic latent image is formed by a magnetic latent image forming means. CONSTITUTION:The device is provided with the cleaning means 60 for cleaning the 1st image fixed by the fixing means 9 before the magnetic latent image is formed by the magnetic latent image forming means 11. The cleaning device 60 is equipped with a main body 61 and a brush 62 and cleans the master image 52 with the rotation of the brush 62. Since the cleaning device 60 is provided on the upstream side of a master image magnetization device 11, the master image 52 is cleaned by the device 60. Thus, the contamination by unfixed developer and foreign matters such as dust, etc., is prevented and the magnetic latent image forming efficiency is prevented from lowering.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a recording device used as a copying machine or a printer.

(Prior art) Electronic copying machines or plate-making machines are used as devices for copying manuscripts.
The printing press is known.

Generally, when making fewer than 1000 copies of the same manuscript, an electronic copying machine is used due to the ease of setup, and when more copies are required, a plate-making/printing machine is used due to the cost. There are many cases.

However, with the passage of time, there is a growing trend to demand cheaper duplication costs, easier operation, and faster processing.

To address these problems, electronic copying machines have traditionally been able to copy at a speed that is closer to that of printing.
Moreover, devices that do not require skilled work or setup, such as plate-making and printing machines, are being put into practical use. However, in order to further increase the copying speed, the electric power required for exposing the original, fixing the developer, charging, etc. becomes extremely large, and there is a serious problem that a normal commercial power source (100 V, 15 A) cannot be used.

Therefore, the applicant of the present application has developed a completely new type of recording device that can be easily operated like an electronic copying machine, can make multiple copies at high speed like a printing machine, and has low power consumption. (Japanese Patent Application Laid-Open No. 63-29273)
.

This new recording device forms an electrostatic latent image on an image carrier, develops this electrostatic latent image with a magnetic developer, and then fixes this developer image on the image carrier to obtain a mask image. Then, this master image is magnetized and a magnetic developer is attached thereon to obtain a transferred image, which is then transferred to a transfer member.

In such a method, even after the transferred image on the master image is transferred to the transfer member, the master image remains on the image carrier with its magnetic force retained, so that the second and subsequent copies of the same In this case, the magnetic developer is deposited on the master image again using the magnetic force of the master image to form a transferred image, and this developer image is transferred to the transfer member. By repeating this process, copies can be made from the same original any number of times. That is, in this printing mode, after the master image is first formed, the above-mentioned charging process, the process of forming an electrostatic latent image, the process of developing the electrostatic latent image, and the process of depositing the developer image on the image carrier are performed. There is no need for any fixation process. Therefore, when a large number of copies are made using this printing mode, power consumption can be reduced and the copying speed can be significantly faster than that of conventional electronic copying machines.

(Problem to be Solved by the Invention) In such an apparatus, in order to obtain sufficient magnetic latent image forming efficiency, it is necessary for the magnetic latent image forming apparatus to come into contact with the fixed master image. Not established in
・There is a risk that such contact may be obstructed by adhesion of glue, dust, etc.

This invention was made in view of such circumstances,
It is an object of the present invention to provide a recording device that prevents deterioration of magnetic latent image forming efficiency due to foreign matter other than developer on an image carrier and that can obtain a uniform and stable magnetic latent image.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention includes a moving image carrier, and a first material containing a magnetic material having magnetic properties capable of permanent magnetization on the image carrier. a writing device for forming a first image using a developer; a fixing device for fixing the first image formed on the image carrier by the writing device on the image carrier; a magnetic latent image forming means for forming a magnetic latent image on the developer; a developing means for developing the magnetic latent image with a second magnetic developer to form a second image; In the recording apparatus comprising a transfer means for transferring the second image obtained on the second image onto the transfer target, the second image is further fixed by the fixing means before the magnetic latent image is formed by the magnetic latent image forming means. A cleaning means is provided for cleaning the first image.

(Function) In this invention, since the cleaning means can remove foreign matter adhering to the first image before forming the magnetic latent image, the magnetic latent image forming means and the fixed first developer can be cleaned. contact can be prevented. Therefore, a uniform and stable magnetic latent image can be obtained without degrading the magnetic latent image forming efficiency.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing a recording apparatus according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a part of the apparatus shown in FIG. Reference numeral 1 in FIG. 1 is a main body of the apparatus, and a drum-shaped image forming member 2 is disposed approximately in the center of the main body 1 of the apparatus. As shown in FIG. 2, a charging device 3. Exposure section 4a of electrostatic latent image forming device 4, first developing device 5. Second developing device6. Pre-transfer charging device 7 Transfer device 8. Master image fixing device9. A static eliminator 10.degree. cleaning device 60 and a master image magnetization device 11 are arranged in this order. Of these, exposure device 3, exposure device 4
The first developing device 5 constitutes a master image writing device for writing a master image, which will be described later.

Further, in the apparatus main body 1, paper P as a transfer member fed from a paper feed cassette 12 mounted on the right side of the apparatus main body l via a paper feed means 13 is placed between the image forming member 2 and the transfer device 8. A paper transport path 16 is formed to transport the paper to a paper discharge tray 15 mounted on the left side of the apparatus main body 1 via an image transfer section 14 between the paper and the paper.

Further, a pair of aligning rollers 17 is arranged on the upstream side of the paper transport path 16, and a fixing device I8 and a pair of paper ejection rollers I9 are arranged on the downstream side. Furthermore, a cooling fan unit 20 is provided above the fixing device 18 .

Further, at the upper part of the apparatus main body 1, a document reading device 22 is provided which reads a document placed on a document table 21 and outputs an image signal. This document reading device 22 includes an exposure lamp 24 mounted on a carriage 23 that reciprocates in the horizontal direction (in the direction of the arrow) along the surface of the document, and that irradiates light onto the document.
．． Optical transmission body 25 that transmits reflected light from the original document. and a well-known scanner unit equipped with a photoelectric conversion element (CCD) 2G that converts the optical signal transmitted via the optical transmission body 25 into an electrical signal. Incidentally, reference numeral 27 denotes an openable and closable document presser that presses the document tray.

The image forming member 2 also includes a photoreceptor belt 31 as an image carrier, which has a photosensitive layer 31a of zinc oxide sensitized with a long-wavelength dye such as rose bengal on the outer periphery of a non-magnetic drum 30 as a support. It has a structure that is wrapped around
At least the first speed v is controlled by a drive mechanism (not shown).
1 and a second speed v2 that is several to several tens of times faster than this. Further, the photoreceptor belt 3
1 is wound such that both ends thereof are wound around a feeding core 32 and a winding core 33 disposed within the non-magnetic drum 30, and the middle portion thereof goes around the outer periphery of the non-magnetic drum 30 approximately once. is wrapped around. A photoreceptor belt 31 is wound around the feeding core 32 in the form of a roll, so that it can be fed out onto the non-magnetic drum 30 by a new predetermined size each time a printing mode to be described later is performed. The used portion is wound up on a winding core 33. A slit 34 is formed in the non-magnetic drum 30 for feeding out a new portion of the photoreceptor belt 31 or introducing a used portion. Also,
If necessary, the image of the part that has already been used can be rewound and used again.

The charging device 3 consists of a corotron type corona charger,
The photosensitive layer 31a as an image carrier is -300 to -150
It is designed to charge uniformly to 0 volts.

The electrostatic latent image forming device 4 is composed of a known laser exposure device, and exposes the photosensitive layer 31a with a laser beam β based on the image information read by the original reading device 22 to form the photosensitive layer 31.
An electrostatic latent image corresponding to image information is formed on a.

The first developing device 5 is a developing device that employs a magnetic component development method, and uses a first magnetic developer T1 that is a carrierless donor.

The magnetic material in the first magnetic developer T has a larger residual magnetization and a larger coercive force than conventionally used magnetic materials. These materials include γ-Fe203, Fe304
, Co-7-Fe202Cr02. Suitable materials include Fe (metal powder) and barium ferrite. Then, 20 to 80% by weight of these fine powders are mixed with the resin,
The particles having an average particle size of 1 to 30 μm are referred to as a first magnetic developer T1. The first developing device 5 is configured to transport the first magnetic developer T1 toward the image forming member 2 as the magnetic sleeve 40 rotates.

The second developing device 6 is a developing device that employs a magnetic component developing method, and is made of Fe, which has high resistance and low residual magnetization.
A second magnetic developer T2 using magnetic powder such as 2O4 is used, and this second magnetic developer T2 is inserted into the magnetic sleeve 4.
As the image forming member 1 rotates, it is carried toward the image forming member 2 side.

The magnetic force of the magnetic sleeve 41 of the second developing device 6 is
This setting is made in consideration of the magnetic force of the developer image developed by the first developing device 5. That is, if the magnetic force of the magnetic sleeve 41 of the second developing device 6 is too large, the developing efficiency will be low and a clear image cannot be obtained, and if it is too small, the second developer T2 will not be conveyed effectively. Furthermore, if the magnetic sleeve 41 of the second developing device 6 forms an external magnetic field that is more effective in holding the developer image developed by the first developing device 5, the magnetic latent image will disappear. It is necessary to select the magnetic force of the magnetic sleeve 41 of the second developing device 6 in consideration of the above.

The pre-transfer charging device 7 consists of a corona charger, and the photosensitive layer 3
Negative polarity is used so that the charge remaining on 1a can be photo-eliminated.

The transfer device 8 has a surface of a belt body made of a conductive material.
It is equipped with an endless transfer belt 43 laminated with a dielectric film such as polyester having a thickness of about 20 to 40 μm, and a transfer belt 43 of about 1000 volts, which has a polarity opposite to that of the corona charger as the pre-transfer charging device 7 described above. A bias voltage is applied. Further, the transfer belt 43 forms a part of the paper transport path 16, and its transport end side extends to the entrance of the fixing device 18. Then, the transferred image is transferred to the paper P side, and the paper P is peeled off from the photoreceptor belt 31 and guided to the fixing device 18 . Note that instead of applying the bias voltage to the transfer belt 43, transfer and peeling may be performed by applying an electric charge to the paper p+, : by corona discharge.

The master image fixing device 9 fixes the developer image visualized by the first developing device 5 onto the photoreceptor belt 31 using a fixing flash using a xenon lamp or the like to form a magnetic master image 52. be.

The static eliminating device 10 includes a static eliminating lamp that removes residual charges by irradiating the image forming member 2 with static eliminating light.

The cleaning device 60 includes a main body 6 as shown in FIG.
1 and a brush 62, and the master image 52 is cleaned by rotation of the brush 62.

As shown in FIG. 4, the master image magnetization device 11 is equipped with a magnetic head 50 consisting of a core 51 and a coil 52 wound around a core, and a current is supplied to the coil 52 from a power source (not shown). By doing this, a magnetic field is generated.

Next, the operation of the recording apparatus configured as described above will be explained. This apparatus is capable of copying the original A in any arbitrary mode, including a print mode suitable for copying multiple copies of the same original, and a copying mode suitable for producing a small number of copies.

First, the print mode will be explained.

As the document reading device 22 starts reading the document, the image forming section +12 consisting of the non-magnetic drum 30 as a support and the photoreceptor bell l-31 as an image carrier moves at the first speed v1 as shown in the arrow. While rotating in the a direction, the fifth
As shown in Figure (a), the photosensitive layer 31a of the photosensitive belt 31 is uniformly negatively charged by the charging device 3. The image information read by the document reading device 22 is photoelectrically converted into a signal by a known means, and the electrostatic latent image forming device 4 irradiates the photosensitive layer 31a with a laser beam ρ corresponding to the image information. As a result, electrostatic island images are formed one after another as shown in FIG. 5(b).

The electrostatic latent image thus obtained is developed by the first magnetic developer T by passing through the first developing device 5. That is, in the developer image forming step by the first developing device 5, as shown in FIG. A developer image 51 corresponding to the image is obtained by electrostatically adhering to the negative charge.

This developer image 51 is generated when the image forming member 2 moves at a speed v1 of the second coat.
By rotating the second developing device 6. Pre-transfer charging device7. The image passes through the image transfer section 14, faces the master image fixing device 9, and is thermally fixed by a xenon lamp.

In this way, the photosensitive layer 31. Mask image 5 fixed on a
2 is opposed to the master image magnetization device 11, as shown in FIG. 5(e), and is permanently magnetized by the magnetic head 50 constituting the master image magnetization device 11. At this time, the photosensitive layer 31. Since a itself is a non-magnetic material, it is not magnetized, and only the master image 52 is magnetized.

When the master image 52 is magnetized in this way, the magnetic head 5o needs to be in close contact with the master image 52 as described above, and unfixed developer and dust are removed between the master image 52 and the magnetic head 50. If such foreign matter is mixed in, the efficiency of forming a magnetic latent image will be reduced. Here, since the cleaning device 60 is provided upstream of the master image magnetization device 11, the master image 52 can be cleaned by this cleaning device 6°, and the contamination of such foreign matter can be prevented.

Therefore, the efficiency of forming a magnetic latent image is extremely high.

While the imaging member 2 thus makes one first rotation,
A magnetized master image 53 is formed, that is, a magnetization pattern as a magnetic latent image is formed.

The image forming member 2 is continuously rotated, but from the second rotation onwards, it is rotated at a high speed at a second speed v2.

Then, the magnetized master image 53 or the second developing device 6
When the second magnetic developer T2 moves to the position shown in FIG. 5(f), it is attracted by the magnetic force of the master image 53 (
=J is vignetted and adheres to the surface of the master image 53, forming a transferred image 54.

The second magnetic developer T2 is attracted to the magnetized master image 53 by magnetic force, and therefore does not necessarily need to be charged. Further, after the transferred image 54 is developed, the image shown in FIG.
As shown in g), a negative charge is given by receiving corona discharge from the pre-transfer charging device 7.

On the other hand, the paper P is fed into the image transfer section 14 via the aligning roller pair I7, and the paper P is sandwiched between the transfer belt 43 and the image forming member 2. Since a bias voltage having a polarity opposite to that of the corona of the pre-transfer charging device 7 is applied to the transfer belt 43, the transferred image 5 as shown in FIG.
4 are electrostatically transferred onto the paper P one after another.

The paper P after the transfer is peeled off from the image forming member 2 as the transfer belt 43 runs and is sent to the fixing device 18.
After the image is fixed by being heated and pressurized at the same time, it is discharged onto the paper discharge tray 15 via a pair of paper discharge rollers 19 .

Note that if the second magnetic developer T2 can be sufficiently charged during development by using a triboelectrically charged toner, it is possible to omit the pre-transfer corona discharge by the pre-transfer charging device 7. be. However, in order to ensure electrostatic transfer in a short time, such as when high-speed transfer is required, it is necessary to give sufficient charge to the second magnetic developer T2 by performing corona discharge before transfer. Good.

Continuing in this print mode, in order to make two copies of the same original from the LI onward, the transferred image forming step shown in FIG. 5(f), the pre-transfer corona discharge step shown in FIG. 5(g), and the fifth Transfer IIT shown in figure (h) at the second speed ■
By repeating the steps 2 and 2, you can make as many copies as you like with the same content. That is, - photosensitive layer 31 as a star image carrier. After forming the master image 53 magnetized in Al, a charging step shown in FIG. 5(a) and an exposure step shown in FIG. 5(b) are performed.

Developer image forming step (unfixed master image forming step) shown in FIG. 5(c), master shown in FIG. 5(d)]7 Image fixing step, and mask image magnetization step shown in FIG. 5(e) You don't have to do it at all. Then, the power required for charging, image exposure, etc. can be applied to the fixing device 1B. Therefore, not only power saving can be achieved, but also the magnetization master image 53
After formation, the printing mode can be performed at high rotational speed (2), thereby making it possible to significantly increase the copying speed. Furthermore, the greater the number of copies made from the same document, the lower the cost per copy.

In addition, in the above printing mode, the photosensitive layer 31. In order to prevent charging due to residual charges, it is better to keep the static elimination lamp of the static elimination device JO on. When the duplication of multiple sheets of a certain original document in print mode is completed, the photoreceptor belt 31 is replaced with a new one. That is, the winding core 33 rotates, and the size on which the master image 53 is fixed is wound onto the winding core 33, and a new unused length is rolled onto the non-magnetic drum 30. It is rolled out.

Next, we will explain the copy mode suitable for copying a small number of copies. I will explain.

The copy mode differs from the print mode described above in that a master image is not formed. In other words, as with Printing Moto,
As the document reading device 22 starts reading the document, the image forming member 2 rotates and the image forming member 2 rotates as shown in FIG.
), the photosensitive layer 31 .
a is uniformly charged.

Next, as shown in FIG. 5(a), a laser beam Ω is irradiated onto the photosensitive layer 31a, and electrostatic latent images corresponding to the original are successively formed. The electrostatic latent image thus obtained is visualized by facing the second developing device 6.

Since development using magnetic force cannot be performed in this copying mode, the second magnetic developer T2, which is positively charged by frictional charging or the like, is electrostatically attached to the negatively charged portion of the photosensitive layer 31a. By doing so, a developer image corresponding to the image to be reproduced is obtained.

Subsequently, the image forming member 2 is rotated and charged by corona discharge by the pre-transfer charging device 7, so that the magnetic developer T2 of the subsequent section 2 is transferred onto the paper P one after another. The paper P after transfer is transferred to the fixing device I as in the print mode.
After being fixed by 8, the paper is discharged onto the paper discharge tray 5.

After the developer T2 remaining on the photosensitive layer 31a after transfer is neutralized by the static eliminating device 10, it is brushed off by the magnetic brush effect in the second developing device 6 while the image forming member 2 makes one more rotation. and collected into the second developing device 6. That is, the copying mode of this embodiment is a two-rotation/one-copy system using magnetic brush cleaning. In this copying mode, the same photosensitive surface of the photosensitive belt 31 is used repeatedly, and when it reaches the zero specified number of times, for example, about 1000 times, it is replaced with a new unused portion.

As described above, in this embodiment, by using the print mode, it is possible to save power when making copies of a large number of copies, and the copying speed is extremely high.

Furthermore, since the cleaning device 60 is provided, the mask image 5
It is possible to prevent foreign matter from entering between the magnetic head 2 and the magnetic head 50, and the efficiency of forming a magnetic latent image can be increased.

Note that this invention is not limited to this embodiment and can be modified in various ways. For example, although zinc oxide is used as the photosensitive layer, the present invention is not limited to this, and photosensitive materials such as amorphous Si may be used. In addition, the image carrier is not limited to a photosensitive layer, and various types of dielectric layer tubes for electrostatic recording can be used.

Furthermore, although the original was exposed with a laser beam, the document may be irradiated with illumination light, and the photosensitive layer may be exposed to the reflected or transmitted light through an optical member such as a mirror lens.

In this embodiment, the writing device includes a charging device, an exposure device,
Although the master image was developed with magnetic toner using a developing device, other methods may also be adopted, such as a method of forming a master image by thermal transfer using a heat-melting type developer. can.

Although a cleaning device using a brush has been shown, the cleaning device is not limited to this, and a type that cleans the master image with a blade made of urethane rubber or the like may also be used.

〔Effect of the invention〕

As explained above, according to the present invention, the first image formed on the magnetic latent image forming means and the image carrier by the cleaning means
Since it is possible to prevent foreign matter from entering between the image and the image, it is possible to make multiple copies from the same original at high speed, and not only does it consume less power, but it also does not reduce the efficiency of forming a magnetic latent image. It is possible to achieve extremely great effects such as being able to obtain high-performance images.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a recording device according to an embodiment of the present invention, FIG. 2 is a partially enlarged view of the device shown in FIG. 1, and FIG.
The figure shows a cleaning device installed in the device shown in FIG. 1, FIG. 4 shows a magnetic head installed in the device shown in FIG. 1, and FIG. 5 shows the recording of the device shown in FIG. 1. FIG. 3 is a diagram for explaining the operation. 1; Apparatus body, 2; Image forming member, 3: Charging device, 4; Exposure device, 5; First developing device, 6: Second developing device, 7
; Pre-transfer charging device, 8; Transfer device, 9. Fixing device, 10
; Static eliminator, 1]; Magnetizer, 30, drum, 31; Photosensitive belt (image carrier), 3, ], a, Photosensitive layer, 51; Developer image, 52; Master! One image, 53; Magnetized master image, 60; Cleaning device, T1; First magnetic developer, T2; Second magnetic developer.

Claims (1)

[Claims] a moving image bearing member; a writing means for forming a first image on the image bearing member with a first developer containing a magnetic material having magnetic properties capable of permanent magnetization; a fixing device for fixing a first image formed on a carrier onto the image carrier; a magnetic latent image forming device for forming a magnetic latent image on the first image fixed by the fixing device; a developing means for developing the magnetic latent image with a magnetic second developer to form a second image; and a developing means for transferring the second image obtained on the magnetic latent image by the developing means to a transfer material. A recording apparatus comprising a transfer means for transferring, further comprising a cleaning means for cleaning the first image fixed by the fixing means before the magnetic latent image is formed by the magnetic latent image forming means. recording device.