JPH10339982A - Electrostatic recorder provided with plural developing devices - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize the entire structure of the recorder by attachably/ detachably housing a belt mechanism and an electrostatic recording unit in a recorder main body and taking it out from the upside of the recorder main body at the time of opening/closing an opening/closing cover. SOLUTION: A carrying belt unit 10 is attachably/detachably attached in the main body 1 of an LED printer. The electrostatic recording units Y, M, C and B can be attached to/detached from a carrying belt unit 10 independently and individually each other. The belt unit 10 can be attached to/detached from the main body 1 as one unit in a state where four recording units Y, M, C and B are mounted on the unit 10. The belt unit 10 or the recording units Y, M, C and B are attached/detached after opening the upper cover 2 of the main body 1 upward. Thus, the electrostatic recorder whose entire structure is miniaturized and which is provided with plural developing devices 23 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic electrostatic recording apparatus in which a plurality of electrostatic recording units are arranged in series and mainly performs multicolor recording. In particular, the present invention provides a belt mechanism that electrostatically attracts and conveys a recording medium, and a belt mechanism that is arranged in series along a movement path of the recording medium that is adsorbed and conveyed by the belt mechanism, and transfers a toner image to the recording medium. The present invention relates to an electrostatic recording apparatus including a plurality of electrostatic recording units that sequentially transfer images.

[0002]

2. Description of the Related Art Conventionally, in an electrostatic recording apparatus, an electrostatic latent image is written on an electrostatic latent image carrier (photoconductor) such as a dielectric, and the electrostatic latent image is charged with a developer as a charged toner image. After being electrostatically developed, the charged toner image is electrostatically transferred to a recording medium such as recording paper, and then fixed onto the recording medium by heat, pressure, light, or the like.

An example of a conventional electrostatic recording apparatus will be described. In a high-speed printer employing an electrophotographic method, a photosensitive drum is used as an electrostatic latent image carrier. During the recording operation, the rotating photosensitive drum is uniformly charged by the pre-charger, and an electrostatic latent image is written in the charged area by the optical writing means. The pre-charger can be configured as, for example, a corona charger or a scorotron charger,
Other pre-chargers include a conductive roller charger and a conductive brush charger. As optical writing means, a laser beam scanner, an LED (light emitting diode) array, and the like are known.

The electrostatic latent image written on the photosensitive drum is electrostatically developed as a charged toner image by a developing device, and the charged toner image is electrostatically transferred to a recording medium such as recording paper by a transfer device. . A recording medium, that is, a recording sheet is fed from a sheet feeding unit, and the recording sheet is temporarily stopped at a pair of registration rollers and waits, and then the recording sheet is set to a predetermined position corresponding to writing of the electrostatic latent image on the photosensitive drum. At this timing, the toner is fed between the photosensitive drum and the transfer device by a pair of registration rollers, whereby the transfer of the charged toner image onto the recording paper is performed at a predetermined location. The transfer unit includes, for example, a transfer unit configured by a corona discharger or the like, and a charge removal unit configured by an AC charge remover or the like. The transfer unit applies a charge of a polarity opposite to that of the charged toner image to the recording paper to charge the charged toner. It has a function to transfer the image from the photosensitive drum to the recording paper side, and the charge eliminator has a function to remove the electric charge from the recording paper immediately after the transfer of the charged toner image to make it easy to separate the recording paper from the photosensitive drum . The recording paper that has undergone the transfer process is sent to a fixing device, where the transferred toner image is fixed on the recording paper.

On the other hand, residual toner that has not been transferred onto the recording paper and adheres to the surface of the photosensitive drum that has undergone the transfer process, and this residual toner is removed by a cleaning device.
In a high-speed printer, it is required to quickly and surely remove the residual toner from the surface of the photosensitive drum, and since the recording is performed on a huge amount of recording paper, the amount of the residual toner to be processed increases. Therefore, a cleaning device is generally used. More specifically, the cleaning device has a toner collecting container having an opening adapted to receive a part of the photosensitive drum, a fur brush provided in the toner collecting container close to the opening, and a toner collecting container. A toner scraping blade provided along the upper edge of the opening, and a transport screw provided at the bottom of the toner collection container. Of course, the fur brush functions to remove residual toner from the surface of the photosensitive drum, and the scraping blade functions to scrape residual toner that could not be removed by the fur brush. The residual toner removed by the fur brush and the scraping blade is once collected in a toner collecting container, and the collected toner is carried from the toner collecting container to a predetermined location by a transport screw.

As a developer used in the above-mentioned developing process, a two-component developer composed of a toner component (fine powder particles of a colored resin) and a magnetic component (fine magnetic carrier) is widely known. In recording, a two-component developer is often used. A developing device using a two-component developer has a developer holding container for holding the two-component developer, and stirs the two-component developer in the developer holding container to frictionally charge the toner component and the magnetic carrier component with each other. A stirrer, and a magnet roller or a developing roller that forms a magnetic brush by adsorbing a part of the magnetic material carrier with a magnetic force. A part of the developing roller is exposed from the developer holding container and exposed to light. Faced with the drum. The toner component electrostatically adheres to the magnetic brush formed around the developing roller, and the toner component is conveyed to the area facing the photosensitive drum, that is, the developing area along with the magnetic brush by the rotation of the developing roller, Then, the electrostatic latent image is developed. Since the developing density of the electrostatic latent image is also affected by the amount of toner conveyed to the developing area, the length of the magnetic brush ears is regulated by the regulating blade in order to homogenize the developing density. The developer that has passed through the developing area, that is, the developer having a reduced toner component, is scraped off from the developing roller by the scraper member and returned to the agitator side.

When a two-component developer is used as a developer,
Since the toner component is constantly consumed in the developing process, it is necessary to appropriately supply the toner component in order to maintain the quality of the developed toner image, that is, the quality of the recording toner image. One of the factors that influence the quality of the recording toner image is that the toner component is not only sufficiently frictionally charged with the magnetic carrier, but also that the toner component is uniformly distributed in the magnetic carrier. Further, in a high-speed printer, the amount of developer used in the developing process naturally increases, and therefore, it is required to stir the developer quickly and efficiently. For this reason, a circulation type is generally employed as the stirrer. More specifically, the stirrer includes a pair of transport screws and a partition plate disposed therebetween, and the pair of transport screws are disposed in the development holding container in parallel with the developing roller. The pair of conveying screws extend between both side walls of the developer holding container, the length of the partition wall is shorter than the length of the conveying screw, and each of both ends is separated from the corresponding side wall of the developer holding container by a predetermined distance. It is. The transport screw is driven to transport the developer in opposite directions, thereby forming a developer circulation path. That is, when the developer is conveyed to the end by the conveying screw, for example, the developer is moved to the opposite conveying screw side around the corresponding end of the partition plate, and the developer is conveyed to the end by the conveying screw. Then, the partition plate is turned around the opposite end and moved again to the conveying screw side, and thus the developer is circulated along the pair of conveying screws.

[0008]

There is a multi-drum system as a system of a multi-color recording apparatus utilizing an electrostatic recording technique. When multi-color or full-color recording is performed at a high speed by the multi-drum system, the above-described method is employed. Four electrostatic recording units, each of which is a unit of the electrostatic recording apparatus, are provided, and these electrostatic recording units are arranged in series along the endless belt means for conveying the recording paper. The electrostatic recording units have the same structure. The conductive transfer roller is pressed against the photosensitive drum via an upper traveling portion of the endless belt means for conveying the recording paper. A developer having a yellow toner component, a developer having a magenta toner component, a developer having a cyan toner component, and a developer having a black toner component are used in each of the developing devices of the electrostatic recording unit. That is, each of the electrostatic recording units records a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image.

A pair of registration rollers is provided at one end of the endless belt means for conveying the recording paper, ie, at the side of the recording paper introduction end. During the recording operation, the recording paper from the paper feed unit is temporarily stopped at a pair of registration rollers and is on standby. In the electrostatic recording unit, an electrostatic latent image is sequentially written on the photosensitive drum of each unit based on image data of each color, and then the recording paper is sequentially passed through the electrostatic recording unit at a predetermined timing, whereby A yellow toner image, a magenta toner image, a cyan toner image, and a black toner image are sequentially transferred onto a recording paper to form a full-color image.
The recording paper having the full-color image obtained in this way passes through a fixing device provided on the other end of the endless belt means, and the full-color image is fixed on the recording paper. Thereafter, the recording paper passes through a discharge roller. The paper is discharged onto a paper discharge tray provided outside the multicolor recording apparatus.

The multi-drum type multi-color electrostatic recording apparatus as described above has an advantage that high-speed multi-color recording can be achieved.
However, a large problem has been pointed out as a large structure because a plurality of electrostatic recording units are arranged in series. In particular, when a high-speed printer is used, since the developing device and the cleaning device have a relatively bulky structure, there is a problem that the multicolor electrostatic recording apparatus is further increased in size.

Accordingly, an object of the present invention is to provide a multicolor electrostatic recording apparatus for performing multicolor recording by arranging a plurality of electrostatic recording units in series, and to reduce the overall structure of the apparatus. To provide an electrostatic recording device having a developing device.

[0012]

According to the present invention, a belt mechanism for transporting a recording medium, and a belt mechanism arranged in series along a movement path of the recording medium transported by the belt mechanism, and a toner image is formed on the recording medium. A plurality of electrostatic recording units for sequentially transferring the recording medium, and an apparatus main body having an accommodation chamber for accommodating the electrostatic recording unit and the belt mechanism, the upper part of which is covered with an opening / closing cover, the belt mechanism and the electrostatic recording unit. Wherein the belt mechanism and the electrostatic recording unit can be taken out from above the apparatus main body when the opening / closing cover is opened / closed. An electronic recording device is provided.

Each of the electrostatic recording units includes a photoreceptor, an exposure device for exposing the photoreceptor to form an electrostatic latent image on the photoreceptor, and a toner for supplying the photoreceptor to the electrostatic photoreceptor. The belt mechanism is configured as a unit including a developing device that develops a latent image, and the belt mechanism includes an endless belt, a roller that drives and conveys the endless belt, a charging mechanism that charges the endless belt, a cleaner, and a recording device. It is characterized in that it is configured as a unit in which a roller for separating a medium and a transfer roller for transferring a toner image developed on the photoconductor from the photoconductor to a recording medium are integrated.

The present invention also relates to a plurality of electrostatic recording devices arranged in series along the movement path of a recording medium conveyed by the belt mechanism and sequentially transferring toner images to the recording medium. The electrostatic recording unit, or the photosensitive member of the electrostatic recording unit or the process unit including the photosensitive member and the developing device is detachably mounted on the upper part of the belt mechanism. It is characterized by.

According to the present invention, a belt mechanism for electrostatically adsorbing and transporting a recording medium, and a belt mechanism arranged in series along the movement path of the recording medium attracted and transported by the belt mechanism, and A plurality of electrostatic recording units for sequentially transferring the toner image, and a fixing device for fixing the toner image on the recording medium after the recording medium passes through the belt mechanism,
Wherein the fixing device is detachably mounted on the apparatus main body.

The apparatus body has a front cover, and the fixing device can be taken out of the apparatus body by opening the front cover. A plurality of the electrostatic recording units are attached to a common case and are grouped. Further, according to the present invention, a belt mechanism that electrostatically attracts and conveys a recording medium, and a belt mechanism that is arranged in series along a movement path of the recording medium that is attracted and conveyed by the belt mechanism, and A plurality of electrostatic recording units for sequentially transferring toner images, each of the electrostatic recording units includes a photoconductor and a developing device, and the belt mechanism is conveyed by being attracted to the belt mechanism. A transfer roller disposed opposite to the photoreceptor via a recording medium, wherein the transfer roller transfers a toner image on the photoreceptor onto the recording medium; A mechanism for making the conveyance speed of the plurality of electrostatic recording units variable, and controlling which of the plurality of electrostatic recording units is operated and which of the electrostatic recording units is not operated Characterized by being configured to cut, electrostatic recording apparatus having a plurality of developing devices is provided.

One of the operation modes of the electrostatic recording unit is monochrome printing, and the other operation mode is color printing. The conveyance speed of the recording medium during monochrome printing is determined by the conveyance speed of the recording medium during color printing. It is characterized by a higher speed. When the electrostatic recording unit is in operation, the transfer roller is set to a position where the transfer roller faces the photosensitive member of the electrostatic recording unit via the recording medium on the belt mechanism, and when the electrostatic recording unit is not in operation, the transfer roller is It is characterized in that it is configured to be retracted from the photoconductor.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a multicolor electrostatic recording apparatus according to the present invention will be described in detail with reference to the accompanying drawings. First, referring to FIG. 1, a full-color compatible LED printer is schematically shown as a multicolor electrostatic recording apparatus according to the present invention. The LED printer includes a transport belt unit 10 for transporting a recording medium, for example, recording paper.
The transport belt unit 10 includes an endless belt 11 formed of a flexible dielectric material such as a suitable transparent synthetic resin material. The endless belt 11 is stretched around four rollers 12a, 12b, 12c and 12d. The transport belt unit 10 is housed inside the apparatus main body 1 as described later, and can be taken out from the inside of the apparatus main body 1 upward.

As shown in FIGS. 4 and 5, the apparatus main body 1 has a storage chamber 2 having an open top, in which a transport belt unit 10 and four electrostatic recording units B, C, M,
Y is accommodated. Opening and closing covers 3 and 4 for covering the upper opening of the accommodation chamber 2 can be opened and closed in opposite directions of the arrows a and b around the rotating shafts 5 and 6, respectively. The roller 12a functions as a driving roller, and the driving roller 12a drives the endless belt 11 to travel in a direction indicated by an arrow in the drawing by an appropriate driving mechanism (not shown). The driving roller 12a also functions as an AC discharging roller for removing charges from the endless belt 11. On the other hand, the roller 12b functions as a driven roller, and the driven roller 12b
It also functions as a charging roller for giving an electric charge to 1. The rollers 12c and 12d both function as guide rollers, and are arranged close to the driving roller 12a and the driven roller 12b, respectively. Driven roller 12b and guide roller 12
c, a tension roller (not shown) is provided,
The tension roller applies an appropriate tension to the endless belt 11. Driving roller 12a and driven roller 12
b, the upper traveling portion of the endless belt 11 defined between
A moving path of the recording paper is formed.

The recording medium, that is, the recording paper is
The recording paper is fed out one by one from the uppermost recording paper in the hopper 13 by the pick roller 14, passes through the recording paper guide path 15, and is driven by the pair of recording paper feed rollers 16. From the driven roller 12b side to the recording paper moving path. The recording paper that has passed through the recording paper movement path is discharged from the drive roller 12a side.

Since the endless belt 11 is charged by the driven roller 12b, the recording paper is electrostatically attracted to the endless belt 11 when the recording paper is introduced into the recording paper moving path from the driven roller 12b side. The displacement of the recording paper is prevented. On the other hand, since the drive roller 12a functions as a charge eliminating roller as described above, the endless belt 11
The charge is removed at a portion in contact with the drive roller 12a. Therefore, when the recording paper passes through the driving roller 12a, the electric charge is removed, and when the recording paper is discharged from the driving roller 12a side, the recording paper does not get caught in the lower traveling path side of the endless belt 11, so that the recording paper can be easily removed from the endless belt 11. Can be separated.

The LED printer according to this embodiment has four
And four electrostatic recording units Y, M, C and B. These four electrostatic recording units are arranged along an upper running portion defined between the driven roller 12b and the driving roller 12a of the endless belt 11. The electrostatic recording units Y, M, C, and B are arranged in series from the upstream side to the downstream side within the range, and each of the electrostatic recording units Y, M, C, and B has a developer having a yellow toner component (Y) and a magenta toner component (M). , A developer having a cyan toner component (C), and a developer having a black toner component (B). The electrostatic recording units Y, M, C, and B have the same structure as each other, and form a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image on recording paper moving along the upper running portion of the endless belt 11. The only difference is that recording is performed, and such toner images are sequentially superimposed and recorded, and become a full-color toner image.

FIG. 2 shows each of the electrostatic recording units Y, M, C, and B.
Are shown. Each electrostatic recording unit Y, M, C, B
A photosensitive drum 20 is provided.
Is driven to rotate in the direction of the arrow shown in the figure. A pre-charger 21 configured as, for example, a corona charger or a scorotron charger is disposed above the photosensitive drum 20, and the rotating surface of the photosensitive drum 20 is charged by the pre-charger 21 with a uniform charge. . An electrostatic latent image is written in the charged area of the photosensitive drum 20 by an optical writing unit, for example, an LED beam emitted from an LED beam scanner 22. That is, the LED beam is made to blink based on binary image data obtained from a computer, a word processor, or the like, whereby the electrostatic latent image is written as a dot image.

The electrostatic latent image written on the photosensitive drum 20 is electrostatically charged as a charged toner image with a predetermined color toner by a developing unit 23 disposed on the upstream side of the recording movement path with respect to the photosensitive drum 20. Is developed. The charged toner image is electrostatically transferred to a recording medium such as recording paper by a conductive transfer roller 24 located below the photosensitive drum 20. As shown in FIG. 2, the conductive transfer roller 24 is disposed in contact with the photosensitive drum 20 via the upper traveling portion of the endless belt 11, and the recording paper conveyed by the endless belt 11 is opposite to the charged toner image. A polarity charge is applied, whereby the charged toner image on the photosensitive drum 20 is electrostatically transferred from the photosensitive drum 20 onto a recording sheet.

According to the above configuration, as shown in FIG. 1, the recording paper is introduced from the driven roller 12b of the endless belt conveying means 10 and sequentially passes through the electrostatic recording units Y, M, C and B. By doing so, a four-color toner image is superimposed on this recording paper to form a full-color image,
Next, the recording paper is transferred to the drive roller 1 of the endless belt conveying means 10.
From the side 2a, the sheet is fed to the heat roller type heat fixing device 25, where the full-color image is heat-fixed on the recording paper. The heat roller type heat fixing device 25 is a heat roller 25.
a and a backup roller 25b.
The heat roller 25a and the backup roller 25b are driven in the direction of the arrow shown in FIG. 1, and the recording paper discharged from the drive roller 12a side of the endless belt transport means 10 is introduced between the nips of the rollers 25a and 25b. The transfer toner image on the recording paper surface is
The transfer toner image is heated and melted by being pressed by 5b, whereby the transfer toner image is thermally fixed on the recording paper. The recording paper on which the transferred toner image has been fixed by passing through the heat roller type heat fixing device 25 passes through guide rollers 26 and is accumulated on a stacker 27 provided above these LED printers.

On the other hand, each of the electrostatic recording units Y, M, C, B
In the above, the residual toner which has not been transferred to the recording paper adheres to the surface of the photosensitive drum 20 which has undergone the transfer process, and this residual toner is provided downstream of the photosensitive drum 20 in the recording paper moving path. Toner cleaner 28 (FIG. 2)
Removed by The removed residual toner is returned to the developing device 23 by a toner recirculating device including a screw conveyor 29 and the like, and is used again as a developing toner.

As shown in FIG. 2, the developing device 23 includes a developer holding container 30 in which a toner component (fine powder particles of a colored resin) and a magnetic component (fine magnetic material) are contained. (Carrier). In the opening of the developer holding container 30, a magnet roller, that is, a developing roller 31, is disposed in such a manner that a part of its surface is exposed. The developing roller 31 includes a shaft core portion fixedly supported by both side wall portions of the developer holding container 30 and a sleeve rotatably disposed around the core portion and formed of a non-magnetic material such as aluminum. When the developing device 23 operates, the developing roller 31
Is rotationally driven in the direction indicated by the arrow in the figure.

When the illustrated developing unit 23 is installed in the electrostatic recording apparatus, the exposed surface of the developing roller 31, that is, the sleeve, is opposed to the surface of a carrier such as a photosensitive drum that carries an electrostatic latent image. The bottom wall portion of the developer holding container 30 serves as a developer pool, and a paddle roller 32 is provided in the developer pool. The paddle roller 32 is rotatably supported by both side wall portions of the developer holding container 30 and is driven to rotate in a direction indicated by an arrow in FIG. The paddle roller 32 supplies the developer in the developer pool toward the developing roller 31.

Conversely, a magnetic brush is formed around the developing roller 31 by a magnetic component of the developer, that is, a magnetic carrier, as is well known. The toner component electrostatically adheres to the magnetic brush, and is conveyed to a region facing the photosensitive drum 20, that is, a developing region by the rotation of the developing roller 31. In order to regulate the amount of the developer conveyed to the developing area by the developing roller 31 to a predetermined amount, a developer regulating blade 33 is attached opposite to the lower side of the developing roller 31.

Although not shown in detail, the toner cleaner 28 has a toner collecting container having an opening for receiving a part of the photosensitive drum 20, and a toner collecting container having an opening close to the opening inside the toner collecting container. A fur brush, a toner scraping blade provided along the upper edge of the opening of the toner collection container, and a transport screw 29 provided at the bottom of the toner collection container. Photosensitive drum 1
Residual toner is wiped off from the surface of the photosensitive drum 20 by the fur brush, and residual toner that cannot be wiped off by the fur brush is scraped off the photosensitive drum 20 by the scraping blade. The residual toner removed by the fur brush and the scraping blade is once collected in the toner collecting container, and the collected toner is returned to the developing device 23 by the conveying screw 29.

The developing unit 23 performs the following developing process. For example, when the toner component of the developer is charged with negative charge, a negative uniform charging area is formed on the rotating surface of the photosensitive drum 20 by the pre-charger 21. When the charged area of the photosensitive drum 20 is irradiated with the LED beam emitted from the LED beam scanner 22, a negative charge is released from the irradiated area to generate a potential difference. That is, an electrostatic latent image is written as a potential difference in the charged area of the photosensitive drum 20. For example, if the potential of the charged area of the photosensitive drum 20 is -600 volts, the potential of the electrostatic latent image is
Can be reduced to around -15 volts. On the other hand, a negative developing bias voltage, for example, −400 volts is applied to the developing roller 31, and an electric field is formed between the developing roller 31 and the photosensitive drum 20. The negatively charged toner component is caused to fly toward the photosensitive drum 20 due to an electric field between the developing roller 31 and the photosensitive drum 20, and
Attached on top and developed.

FIG. 3 shows a state in which the transport belt unit 10 is lifted from the apparatus main body 1 of the LED printer as a unit with four electrostatic recording units Y, M, C and B mounted thereon. FIG.
FIG. 4 is a schematic sectional view showing the same state as FIG. 3, and FIG. 5 is a perspective view showing a part of the unit mounting mechanism. The hopper 13, the pick roller 14, the recording paper feed roller 15, the recording paper guide path 15, the heat roller type fixing device 25, the guide roller 26, the stacker 27
Etc. are provided.

The structure in which the transport belt unit 10 is detachably mounted to the apparatus main body 1 of the LED printer is as follows. That is, as shown in detail in FIG. 5, both side plates 41 forming the accommodation chamber 2 in which the upper part of the apparatus main body 1 is open.
a and 4b, frames 42a and 42b for attaching the conveyor belt unit are respectively symmetrically attached to the inside,
Pins 43a each having a tapered tip at two front and rear positions are provided at the horizontal portions of the frames 42a, 42a.
43b is fixed so as to face upward. On the other hand, the corresponding frames 45a and 45b are respectively attached to the outer sides of both side plates 44a and 44b of the conveyor belt unit 10, and the pins 43a and 43b are inserted into the horizontal portion of each frame at two front and rear positions. Holes 46a, 4
6b (FIG. 5). In addition, on the outer side of both side plates 44a and 44b of the conveyor belt unit 10, an inverted U extending substantially vertically upward in parallel with the both side plates 44a and 44b.
A pair of handles 47 (47a, 47b) in a letter shape are symmetrically attached.

Therefore, the transport belt unit 10 is
When the operator lifts and removes the ED printer from the apparatus main body 1, the operator lifts the transport belt unit 10 upward as indicated by arrows while holding the pair of handles 47 a and 47 b with both hands, and moves the frame 4 of the transport belt unit 10.
Holes 46a, 46b of 5a, 45b are pins 43a, 43b.
Just remove it from the conveyor belt unit 10
Can be easily removed from the apparatus main body 1 of the LED printer. On the other hand, when attaching the transport belt unit 10 to the apparatus body 1 of the LED printer,
While holding the pair of handles 47 (47a, 47b), the holes 46a of the frames 45a, 45b of the transport belt unit 10
By simply inserting the 46b into the pins 43a and 43b, the conveyor belt unit 10 can be positioned and mounted at a predetermined position on the apparatus main body 1 of the LED printer. As described above, in this embodiment, the handles 47 (47a, 47b) are simply used without using a special auxiliary means for moving the transport belt unit 10 with respect to the apparatus main body 1, for example, a drawer rail or the like. By simply moving the transport belt unit 10 in the vertical direction (that is, in the direction of gravity) while holding it, the transport belt unit 10 can be attached to and detached from the mounting body 1 very easily. When attaching and detaching the transport belt unit 10 to and from the mounting body 1 of the LED printer, although not shown in detail, the upper cover 2 of the mounting body 1 forming the stacker 27 of printed recording paper is not shown.
Of course must be performed after opening upward.

As is clear from the above, the transport belt unit 10 can have a unit structure integrated with the four electrostatic recording units Y, M, C and B mounted thereon. Positioning of the electrostatic recording units Y, M, C, and B with respect to the apparatus main body 1 when the transport belt unit 10 having such an integrated unit structure is mounted on the apparatus main body 1 is performed as follows. That is, as is apparent from FIG. 4, each of the electrostatic recording units Y,
A pair of pins 48 (48a, 48b) projecting from both sides are provided on both sides of the M, C, and B developing units 23, while the pair of pins 48 (48a, 48b) inside the side plates 41a, 4b of the apparatus main body 1 are provided. A pair of developing device mounting plates 49a and 49b are provided symmetrically above the frames 42a and 42b, and these developing device mounting plates 49a and 49b are provided at substantially equal intervals in a substantially horizontal direction.
A plurality of developing device mounting holes or grooves 50a, 50b are provided, and pins 48 (48a, 48b) of the developing device 23 of each of the electrostatic recording units Y, M, C, and B are connected to predetermined developing device mounting holes or grooves. By inserting the electrostatic recording units Y, M, C, and B with respect to the printer apparatus main body 1 by inserting the electrostatic recording units into the printer units 50a and 50b, the positioning is performed.

FIG. 6 shows four electrostatic recording units Y, M, C
And B can be independently attached to and detached from the transport belt unit 10, respectively, and the transport belt unit 10 is mounted thereon with four electrostatic recording units Y, M, and C.
An embodiment is shown in which the device B is mounted on the apparatus main body 1 and can be detachably attached to the apparatus body 1 as a unit. The structure in which the transport belt unit 10 is detachably attached to the apparatus main body 1 of the LED printer is exactly the same as that described with reference to FIGS.

The structure for attaching and detaching the individual electrostatic recording units Y, M, C and B to and from the conveyor belt unit 10 is as follows. That is, each of the electrostatic recording units Y, M,
The point that a pair of pins 48 (48a, 48b) projecting outward is provided on both sides of the C and B developing units 23 is the same as in the above-described embodiment, but is shown in FIG. As described above, in this embodiment, a pair of developing device mounting plates 51 (51a, 51b) provided symmetrically inside the both side plates 41a, 4b of the apparatus main body 1 of the LED printer are provided with the respective electrostatic recording units Y, M, Four portions are provided at substantially equal intervals in a substantially horizontal direction corresponding to the developing devices 23 of C and B, and the respective developing device mounting plates 51 are provided.
(51a, 51b) include developing device mounting grooves 52 (52a, 52a).
52b) are provided. This developing device mounting groove 52 (5
2a, 52b) are pins 48 (48a, 48) of the developing device 23.
In order to facilitate the insertion and positioning of b), the upper portion has a large groove width with respect to the diameter of the pin 48, and the upper portion has an open shape. So that it is positioned at an accurate position.

When removing each of the electrostatic recording units Y, M, C and B from the conveyor belt unit 10, the predetermined electrostatic recording units Y, M, C and B are moved upward from the conveyor belt unit 10 as shown by arrows. The pin 48 (48a, 48b) can be easily removed simply by lifting the pin 48 (48a, 48b) from the mounting groove 52 (52a, 52b). When attaching the electrostatic recording units Y, M, C, and B to the transport belt unit 10, the electrostatic recording units Y, M, C, and B are moved downward, and the pins 48 (48a, 48b) are moved. Can be easily mounted simply by fitting them into the mounting grooves 52 (52a, 52b). Thus, in the present embodiment, desired electrostatic recording units Y, M, C and B
It is extremely easy to independently remove the toner from the transport belt unit 10 to replenish the predetermined toner to the predetermined developing device 23 and to perform maintenance. In addition, one or a plurality of the toners can be detached from the transport belt unit 10 singly, so that toner of a desired color is not formed.
For example, only the electrostatic recording unit B is detached from the transport belt unit 10, and a black toner image is not formed. Can also be formed. In addition, the electrostatic recording units Y, M, and C of the color toner are removed from the transport belt unit 10 and the black (black)
It is also possible to print a monochrome image using only the toner image.

As shown in FIG. 6, attachment / detachment of each of the electrostatic recording units Y, M, C and B from the conveyor belt unit 10 may be performed after the conveyor belt unit 10 is detached from the apparatus main body 1 of the LED printer. Alternatively, the transfer may be performed while the transport belt unit 10 is attached to the apparatus main body 1 of the LED printer. The attachment / detachment of the transport belt unit 10 or each of the electrostatic recording units Y, M, C, and B is not shown in detail, but must be performed after the upper lid 2 of the mounting main body 1 is opened upward. Of course.

Although not shown in detail in the LED printer according to the embodiment shown in FIGS. 3 and 5, the printed recording paper after passing through the fixing unit 25 passes through the discharge paper 3 The pair of guide rollers 26 are attached to the front cover 3, and when the front cover 3 is opened forward around a pivot shaft (not shown) on the lower side of the front cover 3, the front cover 3 becomes three pairs of guides. The upper part of the fixing unit 25 is opened by moving forward together with the roller 26, and in this state, the fixing unit 25 can be pulled out from the apparatus main body 1 of the LED printer. Therefore, although not shown in detail, the attachment and detachment of the fixing device 25 to and from the mounting main body 1 can be performed very easily, and the convenience in exchanging the fixing device 25 and the like is achieved.

FIG. 7 shows another embodiment of the conveyor belt unit. The transport belt unit 10a includes an endless belt 11 formed of a flexible dielectric material, for example, a suitable synthetic resin material.
It is similar to the embodiment shown in FIG. 1 in that it is bridged around 2a, 12b, 12c and 12d. Further, the roller 12a functions as a driving roller, and the roller 12b functions as a driven roller, and the functional point is the same as that of the embodiment shown in FIG.

The roller 12e facing the driven roller 12b and immediately before the paper feeding position functions as a charging roller, and the roller 12f facing the driven roller 12b and located at the paper feeding position functions as a charging roller. . FIG.
In the figure, reference numeral 54 denotes a power supply, 55 denotes a protection circuit, and 56 denotes a power supply that is installed immediately before the drive roller 12a.
4B) is to be cleaned.
Reference numeral 7 is provided at a position facing the roller 12d, and cleans the surface of the endless belt 11 (the surface that contacts the photosensitive drums 20Y, 20M, 20C, and 20B).

The transport belt unit 11a according to this embodiment is configured such that one or more groups of transfer rollers 24Y, 24M, 24C and 24B
0Y, 20M, 20C, and 20B, by pulling down or pulling it down from a predetermined position,
The charged endless belt 11 and the photosensitive drums of any of the electrostatic recording units Y, M, C, and B can be switched to a non-operation state or an operation state. In the embodiment shown in FIG. 7, as shown, only the transfer roller 24B corresponding to the electrostatic recording unit B that performs transfer using black toner is pulled down, and only the electrostatic recording unit B is deactivated. It is in the state of.

FIGS. 8A to 8C show transfer rollers 24Y and 24Y.
24M, 24C and 24B are transferred to the photosensitive drums 20Y and 20Y.
FIG. 2 schematically illustrates a structure that is separated from and connected to M, 20C, and 20B. Each transfer roller 24Y, 24M, 24C
And 24B are rotatably attached to one end of a substantially L-shaped lever 61 as shown. In the illustrated embodiment, the shaft of each transfer roller is attached to a long hole of one end of a substantially L-shaped lever 61, so that the position of the transfer roller with respect to the photosensitive drum is automatically adjusted. The levers 61 are attached to a shaft 62 at the center of a substantially L-shaped bent portion, and these levers 61 can pivot about the shaft. One end of a spring 67 is connected to the other end of each lever 61, and the other end of these springs 67 is fixedly connected to a stationary portion, and the transfer rollers 24Y, 24M, 24C, and 24B respectively correspond to the corresponding photosensitive drums. 20Y, 20M,
20C and 20B. Pins 63 are provided in the vicinity of the center on the other end side of each lever 61, and these pins 63 are connected to the electrostatic recording units Y,
It is located in each groove 65Y, 65M, 65C and 65B of the guide bar 64 extending in the tandem direction in which M, C and B are arranged. A cam 68 is provided as a mechanism for moving the guide bar 64 in the horizontal direction. The cam 68 is always in contact with a part 64a of the guide bar 64, and the rotation of the cam 68 causes the guide bar 64 to move substantially horizontally. Move in the direction.

Each groove 65Y, 65M, 6 of the guide bar 64
The positional relationship between 5C and 65B and the pin 63 of each lever 61 is as follows. As shown in FIG. 8A, in the state where the transfer roller is in contact with the corresponding photosensitive drum in all of the electrostatic recording units Y, M, C and B, pins other than the black toner electrostatic recording unit B are pinned. 63 is at a position close to the left edge of the grooves 65Y, 65M, 65C. In this case, the pin 6 corresponding to the electrostatic recording unit B
Reference numeral 3 is located substantially at the center of the groove 65B.

Next, only the black toner electrostatic recording unit B is kept in contact with the transfer roller 24B in contact with the photosensitive drum 20B, and the other color toner electrostatic recording units B are deactivated to perform monochrome printing. In this case, as shown in FIG. 8B, the cam 68 is rotated by a predetermined angle in the direction of the arrow, and the guide bar 64 is moved to the right by a predetermined distance. As a result, the levers 61 corresponding to the color toner electrostatic recording units Y, M and C are
, The transfer rollers 24Y, 24M and 24C move away from the photosensitive drums 20Y, 20M and 20C. Therefore, only in the black toner electrostatic recording unit B, the transfer roller 24B is kept in contact with the photosensitive drum 20B, and the other color toner electrostatic recording units Y, M, and C are deactivated.

In the case where all the transfer rollers 24 are separated from the photosensitive drum 20B to be in a non-operation state, FIG.
As shown in FIG. 7, the cam 68 is further rotated by a predetermined angle in the direction of the arrow, and the guide bar 64 is moved rightward in the drawing again by a predetermined distance. Thereby, all the transfer rollers 24Y,
Photoconductor drum 2 corresponding to 24M, 24C and 24B
Apart from 0Y, 20M, 20C and 20B, all electrostatic recording units Y, M, C and B are deactivated.

As described above, the active and inactive states of the electrostatic recording units Y, M, C and B in any combination can be selectively switched. In this case, for example, in the operation mode of monochrome (black) printing in which only the electrostatic recording unit B is in the operating state, the transport speed of the recording medium by the transport belt unit 10 is switched to high speed, and the electrostatic recording unit Y , M, and C, or in addition to the above, in the color printing operation mode in which the electrostatic recording unit B is also in the operating state, the conveyance of the recording medium by the conveyance belt unit 10 is switched to a low speed. It is also possible to control the speed.

FIG. 9 is a schematic block diagram showing a case where the printing speed is changed by changing the operation mode. That is, the operation mode detection means detects whether the operation mode is monochrome (black) printing or color printing, and the controller sends a signal to the conveyance speed control means to drive the belt drive motor to high-speed drive or low-speed drive. Control. Thus, in the case of simple monochrome (black) printing, a high-speed printing mode is set, and a large amount of printing can be performed in a short time. On the other hand, in the case of color printing,
Although a certain period of time is required for printing, it is possible to obtain a printed matter of fine full-color tone.

As described above, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and various forms and modifications are possible within the spirit and scope of the present invention. It should be noted that variations, modifications, etc. are possible. For example, in the above embodiment, the electrostatic recording units Y, M, C and B are all the same size,
Although described as a form, the size and form of these consumable parts can be changed as appropriate. More specifically, for example, by increasing the size of the toner container of the frequently used developing device and decreasing the size of the toner container of the less frequently used developing device, for example, all the electrostatic recording units Y, The life of the consumable parts M, C, and B and the toner replacement time can be made substantially equal. Also, for example, the photosensitive drums 20Y, 20M, 20C and 20 of the electrostatic recording units Y, M, C and B
By changing the film thickness of the surface of B or the material of the surface, similarly, the life of each of the photosensitive drums 20Y, 20M, 20C and 20B and the toner replacement time can be made substantially equal.

FIG. 10 shows an embodiment of the present invention. The difference from FIG. 1 is that the electrostatic recording units Y, M, and C are assembled in a common case 70 separately from the electrostatic recording units B to form a group. The electrostatic recording units Y, M, C and B can be handled separately. Incidentally, reference numeral 71 denotes a common case for accommodating the electrostatic recording unit B, and reference numerals 72 and 73 denote handles attached to the respective common cases.

As described above, if the electrostatic recording units Y, M, C and B can be handled separately, for example, when replenishing the B toner in a case where there is a lot of monochrome printing, only the electrostatic recording unit B needs to be taken out. Work becomes easier.

[0053]

In the above-described multi-drum type multi-color electrostatic recording apparatus, a plurality of electrostatic recording units are arranged in series, but the overall structure of the apparatus is not so large. Instead, the developing device and the cleaning device are arranged effectively. Thus, it is possible to obtain an electrostatic recording apparatus having a plurality of developing units, which can reduce the size of the entire structure of the apparatus.

[Brief description of the drawings]

FIG. 1 is a multicolor electrostatic recording device (LED printer) of the present invention.
FIG. 2 is a schematic view showing one embodiment of the present invention.

FIG. 2 is a diagram illustrating a structure of an electrostatic recording unit.

FIG. 3 is a schematic diagram illustrating a state in which a transport belt unit is removed from a mounting body of the LED printer.

FIG. 4 is a schematic sectional view showing the state of FIG. 3;

FIG. 5 is a detailed perspective view showing a portion for positioning a transport belt unit on a mounting main body of the LED printer.

FIG. 6 is a schematic diagram illustrating a state in which a transport belt unit is removed from a mounting body of the LED printer, and an electrostatic recording unit is further removed from the transport belt unit.

FIG. 7 is a multicolor electrostatic recording device (LED printer) of the present invention.
FIG. 4 is a side view of a conveyor belt unit used in the embodiment.

FIGS. 8A, 8B, and 8C are schematic diagrams showing a mechanism for moving a transfer roller toward or away from a corresponding photosensitive drum alone or as a group.

FIG. 9 is a schematic block diagram when a printing speed is changed according to an operation mode.

FIG. 10 is a schematic diagram when a plurality of electrostatic recording units are grouped.

[Explanation of symbols]

 Y, M, C, A: Electrostatic recording unit 10: Conveying belt unit 11: Endless belt 12a to 12d: Roller 13: Hopper 14: Pick roller 15: Recording paper guide path 16: Recording paper feed roller 20: Photosensitive drum 21 ... Pre-charger 22 ... LED beam scanner 23 ... Developer 24 ... Conductive transfer roller 25 ... Heat roller type fixing device 25a ... Heat roller 25b ... Back-up flora 26 ... Guide roller 27 ... Stacker 28 ... Toner cleaner 29 ... Screw conveyor DESCRIPTION OF SYMBOLS 30 ... Developer holding container 31 ... Developing roller 32 ... Paddle roller 33 ... Developer regulating blade 41 ... Main body side plate 42 ... Frame 43 ... Pin 44 ... Unit side plate 45 ... Frame 46 ... Hole 47 ... Handle 48 ... Pin 49 ... Developing device Mounting plate 50: Hole or groove 51: Developing device mounting plate 52: Tsukemizo 54 ... power supply 55 ... protection circuit 56 ... cleaning blade 57 ... cleaning blade 61 ... lever 62 ... shaft 63 ... pin 64 ... guide bar 65 ... groove 67 ... spring 68 ... cam

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirofumi Nakayasu 4-1-1, Kamikodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Masakazu Kanehana 4 Kamikadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture 1-1-1, Fujitsu Limited (72) Inventor Shinichiro Yamamoto 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture In-house Fujitsu Limited (72) Inventor Yuzuru Sugiura, 4 Ueodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture 1-1 1-1 Fujitsu Co., Ltd. (72) Inventor Kanada ▲ Yu ▼ No. 4-1-1 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Fujitsu Co., Ltd. (72) Inventor Eiichi Ebihara Nakahara-ku, Kawasaki-shi, Kanagawa 4-1-1 Kamiodanaka Inside Fujitsu Limited (72) Inventor Kazuhiko Hamazoe 4-1-1 Kamiodanaka Nakahara-ku, Kawasaki City, Kanagawa Prefecture Issue Fujitsu within Co., Ltd. (72) inventor Wano Masahiro Kanagawa Prefecture, Nakahara-ku, Kawasaki, Kamikodanaka 4 chome No. 1 Fujitsu within Co., Ltd.

Claims (9)

[Claims] 1. A belt mechanism for transporting a recording medium, and a plurality of electrostatic recording devices arranged in series along a movement path of the recording medium transported by the belt mechanism, and sequentially transferring toner images to the recording medium. A unit, and an apparatus main body having an accommodation chamber for accommodating the electrostatic recording unit and the belt mechanism, the upper part of which is covered by an opening / closing cover, wherein the belt mechanism and the electrostatic recording unit are detachably accommodated in the apparatus main body. Wherein the belt mechanism and the electrostatic recording unit can be removed from above the apparatus main body when the cover is opened. 2. Each of the electrostatic recording units includes a photoconductor,
It is configured as a unit including an exposing device that exposes the photoconductor to form an electrostatic latent image on the photoconductor, and a developing device that supplies toner to the photoconductor and develops the electrostatic latent image. The belt mechanism includes an endless belt, a roller for driving and transporting the endless belt, a charging mechanism for charging the endless belt, a cleaner, a roller for separating a recording medium, and a developing device on the photoconductor. 2. The electrostatic recording apparatus according to claim 1, wherein a transfer roller for transferring a toner image from the photoconductor to a recording medium is configured as an integrated unit. 3. The belt mechanism, and a plurality of electrostatic recording units arranged in series along a movement path of a recording medium conveyed by the belt mechanism and sequentially transferring toner images to the recording medium. Wherein each of the electrostatic recording units, or a photoreceptor of the electrostatic recording unit or a process unit including the photoreceptor and the developing device is detachably mounted on the belt mechanism. An electrostatic recording apparatus comprising a plurality of developing devices according to claim 1. 4. A belt mechanism for electrostatically adsorbing and transporting a recording medium, and a belt mechanism arranged in series along a movement path of the recording medium attracted and transported by the belt mechanism, and for transferring a toner image to the recording medium. A plurality of electrostatic recording units for sequentially transferring,
A fixing device for fixing a toner image on the recording medium after the recording medium has passed through the belt mechanism, wherein the fixing device is detachably mounted to the apparatus main body. 2. The electrostatic recording device according to 1. 5. The electrostatic recording apparatus according to claim 1, wherein the apparatus main body has a front cover, and the fixing device can be removed from the apparatus main body by opening the front cover. 6. The electrostatic recording apparatus according to claim 1, wherein a plurality of the electrostatic recording units are attached to a common case and grouped. 7. A belt mechanism for electrostatically adsorbing and conveying a recording medium, and a belt mechanism arranged in series along a movement path of the recording medium adsorbed and conveyed by the belt mechanism, to transfer a toner image to the recording medium. A plurality of electrostatic recording units for sequentially transferring,
In addition, each of the electrostatic recording units includes a photoconductor and a developing device, and the belt mechanism is disposed to face the photoconductor via a recording medium that is attracted and conveyed by the belt mechanism. A transfer roller that transfers a toner image on the photoconductor onto a recording medium by the transfer roller, and a mechanism that varies a conveyance speed of the recording medium by the belt mechanism, and An electrostatic device having a plurality of developing units, characterized in that it is configured to be able to control which of the plurality of electrostatic recording units is activated and which of the electrostatic recording units is deactivated. Recording device. 8. An operation mode 1 of the electrostatic recording unit
28. The printing method according to claim 27, wherein one is monochrome printing, and the other operation mode is color printing, and the transport speed of the recording medium during monochrome printing is higher than the transport speed of the recording medium during color printing. The electrostatic recording device as described in the above. 9. When the electrostatic recording unit is in operation, the transfer roller is set at a position facing the photosensitive member of the electrostatic recording unit via a recording medium on the belt mechanism, and the non-operation of the electrostatic recording unit is stopped. The electrostatic recording apparatus according to claim 27, wherein the transfer roller is sometimes retracted from the photoconductor.