JPH01161372A - Multicolored image forming device - Google Patents

Abstract

PURPOSE:To improve operability and maintenability by integrally loading an image carrier and plural developing means groups onto a supporting member in which can be pulled out of a device main body. CONSTITUTION:Main configuring members including the image carrier 30 in an image recording system, the developing means 36, 37 and 38 and a cleaning means 39 are incorporated into the supporting member 3 independent of the device main body 2 in the form of unit. Therefore, the main configuring members can be detached from the device main body 2 by extremely simple operation. Owing to a sufficient space, developer replenishing means connected to respective developing means 36, 37 and 38 can be readily installed on the front of the device, which is very convenient to replenish developer outside the device, clean and check the device.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention has a built-in multi-color developer. The present invention relates to a multicolor image forming apparatus which obtains color copies by electrophotography.

[Background of the invention]

There are many ways to obtain color images using electrophotography.
A device has been proposed. For example, JP-A-61-10077
As disclosed in Publication No. 0, a latent image is formed and developed on a photoreceptor drum according to the number of separated colors of an original image, and each time the development is performed, the latent image is transferred onto a transfer drum to form a multicolor image on the transfer drum. There is a method of forming a color copy and then transferring it onto recording paper to obtain a color copy. A device using this method requires a transfer drum large enough to transfer one sheet of image onto its circumferential surface in addition to the photoreceptor drum, resulting in a large and complicated structure. is unavoidable.

For example, as disclosed in Japanese Patent Laid-Open No. 61-149972, a latent image is formed and developed on a photoreceptor drum according to the number of separated colors of the original image, and is transferred onto a transfer material each time it is developed. This is a method of obtaining multicolor copies. With this method, it is difficult to overlap multicolor images with high precision, and it is impossible to obtain high-quality color copies.

Another method is to repeatedly form a latent image on a photoreceptor drum in accordance with the number of separated colors of an original image and develop it with color toner, and then layer color powder on the photoreceptor drum and then transfer it to obtain a color image.

The basic process of forming a multicolor image is disclosed in Japanese Patent Application Laid-open No. 60-75850, No. 60-76766, and No. 60-60 by the present applicant.
-954゜56, Fl 60-95458, 60
It is disclosed by Publication No. 158475 Ia et al.

In a multicolor image forming apparatus that obtains a color image through such superimposition, a plurality of developing units containing different color toners are arranged around the periphery of the photoreceptor drum. The photoreceptor drum is rotated multiple times to develop the latent image on the photoreceptor drum to obtain a color image.

In this case, the length of the photoreceptor drum needs to be at least longer than the length of the original; for example, the maximum recording medium is 84 size (3
64 x 257), the drum needs to have a diameter of about 130++a-, taking into account the allowance that will occur in the image forming process. Further, according to research by the present applicant, as detailed in Japanese Patent Application No. 60-296340, a latent image is written on a photoreceptor drum by a writing means; Therefore, during image formation, the cleaning means must be separated from the circumferential surface of the photoreceptor drum, and the cleaning means only comes into sliding contact with the circumferential surface of the photoreceptor drum after the transfer process, but at that time, the cleaning means If the writing by the writing means continues, the images to be superimposed will shift and the image quality will deteriorate, so the diameter of the photoreceptor drum should be set with sufficient margin. It is requested that the size be increased.

The same thing applies to development, and when multiple developing means installed on the peripheral edge of the photoreceptor drum perform development while simultaneously applying a developing bias, there is a difference between the areas developed by a single developing means. This is not desirable. The size of the image carrier drum is determined based on these conditions, and as mentioned above, a large diameter drum is required.

Color images are superimposed on the photoreceptor drum.In a multicolor image forming apparatus, a conventional developing means is used in which a conventional magnetic brush is brought into contact with the image carrier to perform development. I can't. The applicant is Japanese Unexamined Patent Publication No. 5
It has become possible to implement a multicolor image forming apparatus in which toner images are superimposed on an image carrier using the non-contact developing method disclosed in Japanese Patent No. 7-147652.

For general copying machines, as disclosed in Japanese Patent Publication No. 58-54392, a photosensitive drum/developing device is used.

Proposals have been made to attach the cleaner integrally to the support member to facilitate replacement and repair of each unit. A device that was compatible with monochrome and made it easy to replace as a single unit with a disposable structure was published in Japanese Patent Application Laid-Open No. 57/1542.
These are disclosed in Japanese Patent Application No. 55, but all of these are aimed at improving image quality characteristics in a multicolor image forming apparatus characterized by being equipped with a plurality of developing devices such as multicolor and full color.
It has not yet reached the point where the purpose is to improve maintainability and workability.

[Problems to be Solved by the Invention] When a plurality of developing devices are arranged and operated around the periphery of the photoreceptor drum, toner scattering within the device increases compared to a general copying machine, and service is required.・Maintenance work such as maintenance will need to be performed frequently.

On the other hand, multicolor image forming apparatuses, which obtain color images by superimposing toner images on an image carrier as described above, are complex and large in size, and in particular require the use of a plurality of image bearing members. It is necessary to maintain highly accurate gap dimensions between the developing units and the surface of the photoreceptor drum, and it is not expected that complicated ft service and maintenance work will be facilitated when handling multiple developing units. It was close to possible.

In particular, in the case of a developing device using a two-component developer, unless it is disposable, indispensable mincing treatment such as replacing the developer and cleaning the scattered toner is required. In addition, various maintenance tasks are required, such as cleaning and replacing density detectors, cleaning bias contacts, and contact pieces.In particular, handling multiple developing devices in conjunction with single-color image formation makes these maintenance tasks even more complicated. However, no solutions have been provided to simplify these issues.

To summarize, the following problems can be raised.

(1) In the above-mentioned multicolor image forming apparatus for general color images, superimposed color images, etc., the arrangement and shape of individual developing devices are configured in various forms depending on the structure of the apparatus.
There are other problems such as scratching the photoreceptor when pulling out the developing device to replace the photoreceptor or developer. In addition, in order to solve the problem that the toner image on the photoconductor developed with toner of one color is scratched by a developing device containing toner of another color, disturbing the toner image or mixing colors, the contact/separation mechanism is used for individual development. It is extremely complicated to process multiple parts, such as mechanical and time problems such as bias switching, complicated structure, and poor operability. It has many points and is less reliable. There is a tendency.

(2) On the other hand, there are various methods known as rotary developing devices, in which development is performed at the same location while rotating a developing device placed at a predetermined position on a rotating body for each color by a predetermined angle. It is difficult to achieve precision during rotational movement. Particularly in non-contact development, mechanisms such as positioning the gap (Dsd) between the image carrier and the developer carrier are complicated and accuracy is compromised.

There are various problems such as difficulty in speeding up the rotation due to the time constraints required for rotation.

(3) In addition to the size of the photoreceptor drum, it is also caused by fluctuations in Dsd caused by changes in the drum diameter due to temperature changes inside and outside the machine, or by the influence of internal vibrations and external vibration shocks caused by machinery, rotating objects, etc. 34. ) Changes in development characteristics due to fluctuations are a major factor in deterioration of image quality. In practice, the fluctuation of Dsd is ±0
．． While an accuracy of 02 to 0.03 mmff1 Ml is required, the rotational eccentricity of the drum center axis is usually ±o, oos ~
The gap between the drum surface and the developing device is approximately 0.01ffiffl, and the gap between the drum surface and the developing device when assembled into the main body of the device is ±0.1 to 0.3.
It has a fluctuation of about vw. Also, the temperature when using the device (5~
Due to fluctuations in the internal temperature of the machine (at 35°C), current drums based on aluminum materials have a range of ±0.01 to 0.02 m.
It causes expansion and contraction of about m. This, in combination with the potential fluctuation during development described in (2) above, has an adverse effect on image quality such as color mixture and color balance.

Furthermore, the following are major problems that this application aims to solve. Each replenishment hopper for replenishing toner to each of the aforementioned developing devices is usually installed on the side of the group of developing devices in the main body of the device, so it is difficult to connect each developing device to its corresponding replenishment hopper. In addition, it is necessary to provide an opening door for inserting the developer cartridge on the top or side of the device main body for the purpose of replenishing toner to the replenishment hopper. The disadvantages of high manufacturing costs and complicated handling operations for users were unavoidable.

In particular, in an image forming apparatus configured such that the developing device group is integrally mounted together with the image carrier on a support member that can be pulled out from the device main body, the developing device group can be easily removed from the device main body by pulling out the support member for maintenance.・While inspection has been simplified, the problem remains that the replenishment hopper group must be individually removed from the apparatus body separately from the developer group, and therefore maintenance and inspection are not easy.
;.

The present invention solves this problem: As a result, the replenishment hopper group can be installed within a sufficient space, and the replenishment hopper group can also be removed from the main body of the device at the same time as the support member is pulled out. The object of the present invention is to provide a multicolor image forming apparatus.

[Structure of the invention]

The above object includes an image bearing member in the main body of the apparatus, a charging means for imparting an electric charge to the image bearing member, and an exposure means for performing image exposure on the charged image bearing member in accordance with multicolor image information. , a plurality of developing means for developing the electrostatic latent image formed on the image carrier by the exposure means, a transfer means for transferring the developed m-image onto a recording medium, and the image carrier after the transfer. In a multicolor image forming apparatus, the multicolor image forming apparatus includes process means such as a cleaning means for cleaning toner remaining on the plurality of developing devices, and a plurality of replenishing means for replenishing toner to the plurality of developing devices, at least the image carrier and the plurality of developing means group. The plurality of replenishing means corresponding to the plurality of developing means are attached to a rotatable opening/closing member integrally attached to a support member that can be drawn out to the apparatus main body and held in the apparatus main body at the front of the support member. This is achieved by a multicolor image forming device that is characterized by being integrally mounted.

[Detailed description of the invention]

In the present invention, a plurality of developing devices are constructed with a separate compact and thin replenishing means that can obtain good image quality without affecting image quality, and the developing device housing is By making the main part so that it can be used in common for at least two or more developing devices, more specifically, each compact and thin developing device can be placed horizontally (parallel) to the photoreceptor drum axis. Laminated and arranged, preferably 82N
By keeping the height of the multiple developing devices within the drum outer diameter (diameter), and furthermore, by integrally mounting the image carrier and the multiple developing devices on a support member that can be pulled out from the main body of the apparatus, each The developing device and the image carrier are constructed so that they can be easily removed from the main body of the apparatus, thereby facilitating maintenance and inspection. Namely, (1) the complicated arrangement of individual developing units is eliminated, and the arrangement is horizontally stacked, and at least two or more developing units are commonly used, making it easier to operate and develop multiple It is also extremely convenient to handle.Furthermore, the stacked and horizontally arranged developing units can each be pulled out in parallel for maintenance, making it even easier to operate the W&groove. Become something.

By adopting a structure in which the support member is integrally attached to the support member, it is possible to pull out the support body integrally on the front surface and draw out the multiple developing devices horizontally (in parallel to the drum front drawing direction), making it simple to pull out the drum drawer. It is effective because both the developing unit drawer can be pulled out with one touch. Furthermore, not only does this result in complexity in the mechanical structure and ease of maintenance and operability, but also the simplification and simplification of parts through rationalization such as the commonization and compactness of these multiple structures (developers)
Cost reduction is achieved through similarity and commonality, which also leads to a reduction in the number of parts and, of course, improves reliability.

(2) With the above configuration, the gaps between adjacent developing devices can be made almost uniform and small in the rotational direction of the photosensitive drum, and the distance from the charging and exposure operation position to each developing device can also be reduced. Since it can be made short, the influence of the difference in potential attenuation depending on the position of each developing device can be suppressed. In addition, by suspending the structure integrated with the support member on the main body of the device, vibrations and
The aim is to improve image quality by reducing the influence of impact and preventing deterioration of DSD and applied bias, especially in non-contact development during multi-rotation superimposed image creation.

(3) Furthermore, in order to solve the above problems, the present invention provides a developing unit with a separate compact and thin replenishment hopper that can obtain good image quality without affecting the image quality of multiple developing unit groups. By constructing at least two or more main parts of the developing device housing in a structure that can be used in common, more specifically, compact and thin developing devices are stacked horizontally and parallel to the axis of the image carrier. The image carrier and the plurality of developing units are temporarily mounted on a support member that can be pulled out into the main body of the apparatus, and the image carrier and the plurality of developing units are temporarily mounted on a support member that can be pulled out into the main body of the apparatus. The above-mentioned replenishment hopper group is installed in a movable state, and the replenishment hopper group is retracted from the front of the support member when the support member is pulled out or inserted from the main body of the device, thereby simplifying the structure and simplifying the operation. It measures the

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 to 5.

Figure 1 shows the main configuration of a multicolor image forming apparatus.
1 is an image reading system, B is a laser writing system, C is an image forming section, and D is a paper feeding section, and a color image is formed by the following process.

In the reading system A, 11 is a document table;
The original contained in the original is mounted on a carriage 12 that slides in the horizontal direction, and is illuminated by a halogen lamp 13. The movable mirror unit 15 includes mirrors 16 and 1.
7 is installed and also slides horizontally,
In combination with the mirror 14 attached to the carriage 12, the optical image of the document is guided to the lens reading section 20.

The carrier 12 and the movable mirror unit 15 are connected to a stepping motor using wires (both not shown).
, and are slid in the same direction at speeds of v8 and 1/2V, respectively.

The lens reading section 20 includes a lens 21. prism 22,
First reading board 24, red channel (hereinafter R-ch)
CCD 25, second reading board 26, and cyan channel (hereinafter referred to as C-ch) CCD 27.

The optical image of the original transmitted by the mirrors 14, 168 and 17 is focused by the lens 21, and is focused by the prism 22.
The R-ch CCD 25 and the second reading substrate 26 are separated into an R-ah image and a C-ah image by a dichroic mirror provided therein, and are provided on the first reading substrate 24 and the second reading substrate 26.
The respective images are formed on the light receiving surface of the C-ch CCD 27 provided above.

The R-ch CCD25 and C-ah CCD27
The image signal output from the image signal processing section is subjected to signal geography. In the signal processing section, a color signal separated according to the color of the toner is output, and is input to the laser writing system unit B, which is an exposure means.

In the laser writing system unit B, the laser beam is generated by a semiconductor laser (not shown);
The image is rotated and scanned by a polygon mirror 32 rotated by a polygon mirror 32, passes through an Fθ lens 33, has an optical path bent by a mirror 34, and is projected onto the circumferential surface of an image carrier 30 to which a charge has been previously applied by a charger 35 serving as a charging means. Forms bright lines.

On the other hand, when scanning is started, the beam is detected by the index sensor, modulation of the beam by the first color signal is started, and the modulated beam scans the circumferential surface of the image carrier 30. Therefore, an Fl image corresponding to the first color is formed on the circumferential surface of the image carrier 30 by main scanning by the laser beam and sub-scanning by the rotation of the image carrier 30. This latent image is developed by, for example, a developing device 36 loaded with red toner (developing medium) among the developing means, and a toner image is formed on the drum surface. The obtained toner image, while being held on the drum surface, passes under a cleaning device fft39, which is a cleaning means, which is separated from the peripheral surface of the image carrier 30, and enters the next copy cycle.

That is, the image carrier 30 is charged again by the charger 35, and then the second color signal output from the signal processing section is input to the transmission system unit B, and the above-mentioned first color signal is Writing is performed on the drum surface in the same manner as in the case of the drum surface, and a latent image is formed. The latent image uses, for example, blue toner as the second color.

The image is developed by the loaded developing device 37.

This blue toner image is formed in the presence of the previously formed red toner image.

A developing device 38 has black toner, and forms a black toner image on the drum surface based on a control signal generated by a signal processing section. AC and DC biases are applied to the sleeves of each of these developers, and jumping development is performed using two-component developer.
; Development is performed without contacting the image carrier 3o.

The color image thus formed on the circumferential surface of the image carrier 30 is transferred from the paper feed section to the paper feed belt 41 at the transfer pole 40 provided as a transfer means. The image is transferred onto recording paper, which is a recording medium, fed by the feeding roller 42. The recording paper onto which the toner image has been transferred is separated from the drum surface by a separation pole 43 and conveyed to a fixing device 45 via a conveyor belt 44, where the image is fixed.

On the other hand, the blade 39A of the cleaning device 39 comes into contact with the image carrier 30 from which the recording paper has been separated from the drum circumferential surface to remove the remaining toner, and after that, the image carrier 30 is separated from the drum circumferential surface again. A new color image formation process begins.

Next, to explain the layout of each of the main components as described above, as shown in the diagram, the image reading system A is housed in an independent, dedicated body 1 and is mounted on the top of the main body 2, which will be described later. There is.

The main body 2 incorporates an image recording system consisting of the writing system B1, image forming section C1, paper feeding section, etc., and the color information from the image reading system A is connected to the national body I through a group of flexible cables. It is designed to receive signals.

In the main body 2, the image carrier 30 is located approximately at the center, and the developing devices 36, 37, and 38 are arranged horizontally facing the right peripheral surface, while the charger 30 is located on the left peripheral surface. 35 and the cleaning device [39] are arranged.

The image carrier 30. Each developing device 36, 37, 38 and cleaning device 39 are not directly attached to the front and rear pairs of substrates 100 fixed to the main body 2, but are supported by bearings on the support member 3 that is removably inserted into the main body 2. Or it is attached removably.

As shown in FIG. 3, the supporting member 3 is integrally fixed to each other via stays or the like; three panels 3A of similar shapes;
3B and 3C, and can be easily taken out and attached to the main body 2 by means of a pair of left and right guide members 4 each consisting of a plurality of balls and rails.

That is, on the left and right side edges of the support member 3, there are rails 4A,
On the other hand, the rail 4 is located at the position of the main body 2 corresponding to the rail 4A.
C are fixed, and each engages with the rail 4B via a plurality of balls, thereby forming a slidable pair.

Further, a pair of left and right reference bins Pl are attached near the upper side edges of the back surfaces of the panels 3A and 3B, respectively, and hanging portions Q derived from the front and rear boards 100 to which the main body 2 is fixed are attached.
The image carrier 30, each developing device 36, 37, 38, and the cleaning device 39 are suspended from each other by engaging with a hole provided in the hanging portion Ql, and are attached to the supporting member 3 in this state. The relative position with respect to the main body 2 is set. Therefore, when the support member 3 is pulled by the handle 5 on the front side of the three panels, it is pulled out to the front of the main body 2 by the rolling action of the ball, using the rail 4B as a relay member. The reference bottle PI is engaged with the hole of the hanging portion Ql, and the support member 3 is again put into a suspended state and stored in the main body 2.

By holding the support member 3 in a suspended state with respect to the substrate 100 of the main body 2 in this way, the transmission from the motor etc. attached to the main body 2 to the image carrier 30, each developing device or cleaning device is achieved. Even if the vibrations and shocks generated are greatly reduced and absorbed, and slightly transmitted, each piece of equipment will be subject to different vibrations and shocks, so for example, multiple developing units and photoreceptor drums will be relatively
Since it is held in a similar state, there is no major problem in image formation.

In particular, the support member 3 includes an image carrier 30 and a cleaning device 39.
Blade 39A, which must be carried out in the cleaning device for overlay development image formation by integrally holding the blade 39A.
1. Vibrations and vibrations due to delicate pressure contact method, pressure contact state, loading conditions, etc. when the second cleaning roller 39B etc. approaches and separates for disposing of residual toner after the cleaning blade is released, or during pressure contact.
Negative effects such as shock are significantly alleviated and absorbed. These effects are similar to those in which the reference bins P1 on the panels 3A, 3B and the holes in the hanging portions Ql that fit into the main body are replaced with each other and combined. Further, it is sufficient that the panel board is composed of two panels at the front and rear, and it is not necessarily necessary to construct the panel panel with three panels as in this embodiment.

When the above-mentioned superimposed image forming process is used, the image carrier 30 needs to have a circumferential length equal to one page of 84 size or A3 size, which is the maximum recording medium, plus a slight margin. and its outer diameter is at least 130 dma.
In this embodiment, a photosensitive drum of 150 dmm+m is used.

On the other hand, as for each developing device 36, 37, and 38, as will be described in detail later, the outer diameter of the developing sleeve was reduced to 20 mm without deteriorating image performance, and the thickness (height) of each developing device was reduced. As a result, the outer diameter of the image carrier 30 can be sufficiently reduced to about 40 mm or less. It is now possible to further accumulate and arrange them horizontally within a space corresponding to a range of dimensions.

Therefore, the support member 3 is a member that is directly attached or fixed to the main body 2, especially the upper laser writing system B1 and the lower transfer pole 40.
Even if the vertical height is limited to a minimum dimension sufficient to cover the image carrier 30 so as not to affect the layout of each member of the transport system including the separation electrode 43, the cleaning device 39 Needless to say, it is fully possible to mount and accommodate all of the plurality of developing devices 36, 37, and 38, and as a result, the conveyance path of the recording paper can be constructed almost in a straight line, thereby preventing jams. It is effective in preventing jams, and even if jams occur, they can be easily disposed of.

It has become.

Each of the developing units 36, 37, and 38 has the following configuration.

In this embodiment, the developing devices 36, 37, and 38 all have the same structure. The explanation will be given with reference to a cross-sectional view of the developing device 37 shown in FIG.

370 is a housing, 371 is a developing sleeve, 372 is a magnetic roll, 373 is a developer layer forming plate, 374 is a supply roller, 375 is a developer layer stripping plate, 376A, 37
6B is the stirring screw, 377 is the stirring screw 376
This is a stirring partition plate provided between A and 376B.

A developing sleeve 371 disposed within a housing 370 having a thickness of approximately 40 am is a cylinder made of stainless steel with an outer diameter of 20 mm, and its surface is blasted to a depth of 3 μm. Then, it rotates clockwise at 200 to 300 rpm to convey the developer in the direction of the arrow to the developing area.

The magnetic roll 372 is a magnetic body in which SN poles are alternately provided and the 1' pole is removed from the 12 f knee poles, and the developing sleeve 371
Development is done in a fixed form inside the . However, although the magnetic roll 372 is fixed in this embodiment, it may be of a rotating type. A part of the fixed magnetic roll 372 other than the l-pole is a repulsive magnetic field, and a developer layer stripping plate 37 is attached to the developing sleeve 371 at that part.
5, which acts to strip off the developer that has passed through the development area and has been developed.

The supply roller 374 is a sponge roller that rotates clockwise without contacting the developing sleeve 371, and is stirred by the rotation of the stirring screws 376A and 376B, and new toner is supplied to quickly and evenly distribute the developer that was also stirred. It is supplied to the developing sleeve 371.

The new developer is adhered to and conveyed to the developing sleeve 371, and the thickness of the developer layer to be adhered and conveyed is regulated by the developer layer forming plate 373 located on the downstream side.

The developer layer forming plate 373 is an elastic thin plate with one end fixed, and is made of a 0.1 mm thick phosphor bronze plate and a 0.51 mm thick urethane rubber bonded together.
The developing sleeve 371 slides into contact with one circumferential surface with a light pressing force, and transports the regulated developer into a thin layer to the developing area. The amount of developer on the developing sleeve 371 is 6 to 8 my
/ cm”.

The development gap in the development area is maintained at 0.5a+m to provide non-contact development.

Here, the developing bias applied to the developing sleeve 371 is -500V DC bias and 700rmsV T4
This is a type in which a KHz alternating current bias is superimposed.

In the development region, when the above conditions are met, toner is effectively supplied from the thin development layer on the development sleeve 371 toward the latent image surface on the image carrier. As mentioned above, the developer layer is an extremely thin layer (10/Z m to 450 μm).
image bearing member and developing sleeve 37.
1, that is, the development gap, as described above, for example, 5.
By narrowing it down to 00 pm, non-contact development becomes fully possible. When the development gap is narrowed in this way, the electric field in the development area becomes larger, so that sufficient development can be achieved even if the development bias voltage applied to the development sleeve 371 is small, and the advantage of reducing development bias shear discharge, etc. There is. Furthermore, the resolution and other image quality of images obtained by development are generally improved. The allowable width of the development gap is 'Jh total 50 of this development method.
0 ±300 p ta te, preferably If 5
00±150'/J m. There are many practical limitations, and even narrower variations are desired. For example, in the color copying machine of this embodiment, it is very preferable to maintain the value of 500 μ days ±50 μ−. The integral structure of the present invention is also advantageous in this respect.

The developing method using an extremely thin developer layer as described above exhibits remarkable effects, for example, in a developing device with a small diameter sleeve. That is, conventionally, when non-contact development is performed using a small diameter sleeve of about 30 mm or less, a development gap of about Im- is required because it is difficult to regulate the thickness of the developer layer, and for this reason, a high-voltage AC bias is required. In addition, the resolution, gradation reproducibility, and overall image quality of the image obtained by development deteriorate, and in particular, details such as characters are not reproduced sufficiently.
Another drawback is that special consideration needs to be taken in terms of material and size settings, since the developing device is electrically insulated.

Atsu I;.

On the other hand, according to the developing method using the above-mentioned developing device, an extremely thin developer layer is formed and developed, so the development gap can be made small, and the electric field is sufficiently large, so that the image to be developed is The resolution, gradation reproducibility, and other image quality have been significantly improved. In addition, since a small-diameter sleeve is possible, the expensive developing device becomes smaller and costs are reduced, and in color electrophotography, etc., where many developing devices are required, it is easier to arrange image forming equipment, making the entire device more compact. There are advantages.

Further, as explained above, another effect of the developing method is that scattering can be suppressed to a minimum even when carriers and toners with small particle diameters (5 μ- to 100 μs+) are used. That is, when developing using a conventional developer consisting of carrier and toner having small particle diameters, the carrier and/or toner may scatter and contaminate the inside of the device, or toner of a different color may get mixed into the developing device that accommodates color toner. However, according to the developing method described above, the various amounts 1i
mosquito.

significantly reduced.

In addition, another effect is that the development method is non-contact development,
Only the toner selectively flies toward the latent image surface for development, which prevents toner from reaching the latent image surface, which tends to occur especially when reversal development is performed using an image forming body with an organic photosensitive layer. Fogging and carrier adhesion are prevented. In addition, since the latent image surface is not rubbed, there is no damage to the surface of the image forming body or the formation of brush marks, and the resolution and gradation reproducibility are good. can be attached to. Since the multicolor image forming apparatus of the present invention can be developed by overlapping the toner image on the image forming body on which the toner image is formed,
It is suitable for multicolor development.

Further, each of the developing units 36, 37, and 38 is incorporated into the support member 3 so that it can be easily attached and detached by a mounting mechanism as described below.

The case of the developing device 37 will be explained below.
A pair of upper and lower guide pins 51 each having a compression spring fitted thereon are suspended between the fixed handle 50A and the holding piece 52 on the back side.

The movable handle 50B, which is provided and slidably fitted to each of the guide pins 51, is urged rightward.

The handle 50 is fitted onto and supported by the guide pin 51 by a pair of upper and lower boss portions 50A.
A pressing lever 54 biased counterclockwise by a torsion spring 53 is attached to the lower boss portion 50A.

On the other hand, a guide plate 37A on which the developing unit 37 is mounted is fixed to the support member 3, and a "hook-shaped" notch 60 is provided at the side end thereof corresponding to the press lever 54.

When the developing device 37 is attached to the supporting member 3, the pressing lever 54 comes into contact with the linear portion 61 of the notch 60 and is pressed slightly clockwise, and the reaction force pushes the developing device 37. A configuration in which the distance (Dsd) between the image bearing surface and the developing sleeve is maintained at a specified value by pressing in the direction of the image bearing member 30 (for example, a roller provided concentrically with the developing sleeve is brought into contact with the photosensitive drum to close the gap). (not shown).

On the other hand, in order to remove the developing device 37 from the support member 3, the movable handle 50B is slid to the left against the action of the compression spring, and the suppressing lever 54 reaches the inclined portion 62 and returns counterclockwise, and in the process, the lever 54 protrudes. 54A as movable handle 50
It comes into contact with B and stops.

Therefore, when the fixed handle 50A and the movable handle 50B are grasped and pulled at the position where the boss portion 50A abuts the holding piece 52, the pressing lever 54 escapes from the opening of the notch 60 and the developing device 37 is removed. It can be taken out and separated from the support member 3.

Furthermore, when mounting the developing device 37 on the supporting member 3,
The front end of the panel 3A is placed on the guide plate 37A, and the pin 37B attached to the bottom of the developing device 37 is placed on the groove 3A provided in the panel 3A.
・When the movable handle 50B is pushed into engagement with the guide pin 51, the movable handle 50B, which was located at the right end of the guide pin 51, is moved by the action of the compression spring.
The upper suppressing piece 54 comes into contact with the slope part 63 and slides to the left on the guide pin 51 together with the movable handle 50B due to its slope angle.

The pressing lever 54 reaches the opening of the notch 60 and is exposed.

When the device 37 is further pushed in, the movable handle 50B slides to the right due to the action of the compression spring, and the suppression lever 54 slides into the slope portion 62 and rotates slightly clockwise until the straight portion is moved. 61 and the above-mentioned developing device 37
Obtain the energized state of . The developing units 36 and 38 are also attached to and detached from the support member 3 by a similar attachment mechanism.

Furthermore, each developing device 36.37°3 relative to the support member 3
When installing item 8, the dimensions of length, depth, radius, or relative position, and the number of mechanical elements determined by the combination of grooves, holes, notches, etc., and protrusions such as dowels, rails, etc. A fool-proof mechanism is employed, which is a fitting mechanism based on a combination of at least a plurality of elements and a selection of the above-mentioned specifications.

For example, the position in the horizontal direction where the pin 37B and the groove 3A-2 engage is changed depending on the type of developing device, so that it is possible to prevent a different type of developing device from being mistakenly installed.

On the other hand, each replenishment hopper 86, 87, 88, which is a replenishing means prepared for replenishing toner to each of the developing devices 36, 37, and 38, is rotatably supported via a hinge H to a base plate 100 on the front side of the apparatus main body. The hopper is mounted on a hopper mounting plate 85 as shown in FIG.

Each of the supply hoppers 86, 87, 88 is red, blue,
They are fixed to the front hopper mounting plate 85 so as to accommodate each black toner and occupy specified positions in the left and right directions when viewed from the front of the main body of the apparatus, as shown in FIG.

The structure of connection and separation of the replenishment hopper 87 to the developing device 37 and the connection and disconnection of the replenishment port will be described below.

The replenishment hopper 87 is provided with a toner conveying section 87A at its bottom, which includes a conveying screw rotatably driven by a motor M through a gear train G.
provided at the end of the toner replenishing section 90 to the developing device 37;
The structure is such that blue toner is supplied to the printer.

FIG. 3 shows an expanded view of the hopper mounting plate 85 in a closed state with respect to the board 100, and the hopper mounting plate 85 has the replenishment hopper 87 and replenishment hoppers 86 and 88 (not shown) mounted thereon. While holding the hopper mounting plate 85, it is rotated counterclockwise using the hinge () as a fulcrum.
The pair of reference pins P2 provided on the panel 3A are inserted into the reference holes Q2 provided on the panel 3A, and the position relative to each developer is regulated by fitting them. Nl: Clamped by a tightening screw S.

On the other hand, the developing device 37 and further developing devices 36 and 3 (not shown)
Reference numeral 8 has already been attached to the support member 3 by the procedure described above prior to the closing and clamping of the hopper mounting plate 85, and the toner replenishing portion 9 of each replenishing hopper is attached by the closing and clamping operation of the hopper mounting plate 85 to the substrate 100.
0 and the toner replenishing portion 70 of each developing unit are engaged with each other, and the replenishing ports of both are automatically connected.

FIG. 4 shows a developed structure of the toner replenishing device 70 of each developing device and the toner replenishing section 90 of each replenishing hopper.

The toner replenishing section 70 has a rectangular counterbore 70A with the replenishing lower 1 opened on the top surface and a toner conveying screw 7 on the bottom surface.
2 is formed into a semi-cylindrical space 70B for accommodating the toner 3;
It has the function of conveying to 7.

A slit 73 is formed from both sides of the aforementioned counterbore to one outer side of the toner replenishing part 7°, and a thin shirt plate 74 is slidably housed in the slit 73.

The shirt shutter plate 74 is biased to the left by the action of a tension spring 76 stretched between a pin 75 fixed to the toner replenishing portion 7o, and a stopper (not shown) is applied to the shutter plate 74 at the illustrated position where the replenishment lower 1 is shielded. ) and stopped.

On the other hand, the toner replenishing section 90 is a frame-shaped member having a width that fits into the counterbore 70A of the toner replenishing section 7° and having a replenishing port 91 opened approximately at the center of the frame. It is fixed integrally to the end.

A slit 93 is formed in the lower surface of the toner supply section 90, and a thin shirt plate 94 is slidably housed in the slit 93.

The shutter 94 is fixed to the toner replenishing portion 90 and is biased rightward by the action of a tension spring 96 stretched between a pin 95 and a stopper (I; (not shown) and stopped.

Therefore, when the hopper mounting plate 85 rotates clockwise to open the front surface of the support member 3, the replenishment lowers 1 and 91 of each toner replenishment section are both shielded by the shutter plates, preventing toner leakage and dust. The structure completely prevents contamination.

When the hopper mounting plate 85 is rotated counterclockwise to be attached to the board 100 and closed against the board 100, the toner replenishing part 90 is attached to the counterbore part 70A of the toner replenishing part 70.
The taper portion 90B that performs positioning at the time of attachment comes into contact and fits, taking into account the loose play when the developer engages with the developing device corresponding to each of the plurality of replenishing sections.
Its front edge 90A abuts on A.

Therefore, when the hopper mounting plate 85 is attached, the feeder plate 74 idles 7 degrees to the right against the action of the tension spring 76 and opens the supply lower 1, but the counterbore is opened with a slight delay. Since the pin 97 of the shirt flap plate 94 through which the toner replenishing portion 90 is inserted comes into contact with the pin 77 on the side wall of g70A, the shirt flap plate 94 is slid to the left against the action of the tension spring 96 and the toner supply port 91 is slid. begins to open.

The openings of the replenishment lowers 1 and 91 are advanced together with the closing operation of the hopper mounting plate 85, and when the hopper mounting plate 85 is completely attached to the predetermined position of the support member 3, the replenishment lower 1 is completely opened to the replenishment port 91. The toner can fall and flow into the replenishment hopper 87 in accordance with the above conditions.

Each replenishment lower 1.91 is opened in response to the closing operation of the hopper mounting plate 85 as described above, but the replenishment lower 1 is opened somewhat larger than the replenishment port 91, and furthermore, as explained earlier, it is opened in response to the closing operation of the hopper mounting plate 85. Since the opening 91 is configured to open slightly later than the replenishment lower 1, it is possible to prevent toner from leaking, which is likely to occur during connection.

It has also become

In this way, the connection of the toner replenishment ports between each developing device and each replenishment hopper is achieved, and it becomes possible to replenish toner from each replenishment hopper, but on the other hand, toner leakage also occurs due to the opening operation of the hot spring mounting plate 85 from the base plate 100. The toner replenishing section 7o can be automatically separated from the toner replenishing section 90 without causing any trouble.

That is, by rotating the hopper mounting plate 85 clockwise and releasing it from the base plate 100, the pin 97 is attached to the pin 7.
7, the pressing action on the shirt flap plate 94 begins to be released, and after a slight delay, the shirt flap plate 74 begins to be released from the pressure applied by the front edge 90A of the toner replenishing portion 9o. The toner replenishing port 91 is always kept wide open and closed, and when the toner replenishing portion 7o is removed from the toner replenishing portion 90, the toner replenishing portion 7o automatically returns to the shielded state as shown in FIG. 4. In addition, in the above explanation, mutually opening/closing lids were used, but the arrangement and
Depending on the method of opening and closing, it may be possible to use an opening/closing lid only on one side.

Further, toner is supplied to the replenishment hopper 87 from outside the apparatus by attaching a developer cartridge containing toner of a specific color, that is, blue in this case, to the mounting portion 87 at the top of the replenishment hopper 87.
However, since the mounting portion 87B is configured such that a developer cartridge containing toner other than blue cannot be attached, it is possible to accidentally add red or black toner to the developer 37. There is no replenishment. This configuration is also applied to the replenishment hoppers 86 and 88.

Note that each replenishment hopper is connected to a toner conveying section 8 as shown in FIG.
The relay portion 7A is configured to be able to be tilted forward, that is, tilted toward the front at a predetermined angle, thereby facilitating attachment and detachment of the developer cartridge.

In this embodiment, a multi-color image forming apparatus using non-contact multi-rotation overlapping operation will be explained. However, the present invention is not necessarily limited to the multi-rotation overlapping image forming method, and contact type development using the above-mentioned compact developing device will be described. It has been confirmed that a good image can be obtained regardless of the method, and the spirit of the present invention is not limited to the form of the embodiment.

For example, a monocolor one-way type, a multi-color one-way type, which has a contact/separation structure in which multiple developers are separated from the image carrier during non-operation times and brought into contact with the image carrier during operation, or the above-mentioned non-contact developing type; - The purpose of the present invention is to insert the support member in various forms of multi-color image forming apparatuses equipped with a plurality of developing units, regardless of the developing method such as commonly used jump development using AC bias. Automatically connects and disconnects with multiple supply hoppers by disconnecting, or fool-proofing the support member! It is of course included in the gist of the present invention as long as it includes a structure in which a plurality of developing devices installed by a structure are necessarily connected to a plurality of replenishment hoppers in a fool-proof manner.

〔Effect of the invention〕

According to the present invention, the main constituent members of the image recording system, including the image bearing member, each developing means, and the cleaning means, are assembled into a unit in a supporting member independent from the apparatus main body, so that each of the above-mentioned main constituent members can be easily constructed. In addition to allowing the member to be removed from the apparatus main body, the developer replenishment means connected to each of the developing means has sufficient space and is easy to configure, and furthermore, it can be easily configured from outside the apparatus. This allows it to be installed at the front of the inside of the device, which is convenient for replenishing developer, cleaning, and inspection.

As a result, the multicolor image forming apparatus has a simple and compact structure, and has high operational advantages such as prevention of damage to the image carrier and prevention of color mixing that tends to occur when installing and removing the developer. It is to be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a multicolor image forming apparatus of the present invention, FIG. 2 is a sectional view of a developing device used in the apparatus, FIGS. 3 and 5 are perspective views of essential parts of the apparatus, and FIG. FIG. 2 is an exploded perspective view of each toner replenishing section of the developing device and its corresponding replenishing hopper.

Claims (3)

[Claims] (1) An image bearing member in the apparatus main body, a charging means for imparting an electric charge to the image bearing member, an exposure means for performing image exposure on the charged image bearing member according to multicolor image information; a plurality of developing means for developing the electrostatic latent image formed on the image carrier by the exposure means, a transfer means for transferring the developed image onto a recording medium, and a plurality of developing means for developing the electrostatic latent image formed on the image carrier by the exposure means; In the multicolor image forming apparatus, the multicolor image forming apparatus includes process means such as a cleaning means for cleaning toner, and a plurality of replenishing means for replenishing toner to the plurality of developing means, at least the image carrier and the plurality of developing means group. The plurality of replenishing means corresponding to the plurality of developing means are integrally attached to a support member that can be pulled out to the apparatus main body, and the plurality of replenishing means corresponding to the plurality of developing means are integrally attached to a rotatable opening/closing member held in the apparatus main body in front of the support member. A multicolor image forming device characterized by being attached. (2) The multicolor image forming apparatus according to claim 1, wherein each of the replenishing means replenishes the developer by tilting forward with respect to the mounting substrate. (3) The developer cartridge coupled to the plurality of replenishing means is configured such that only a developer cartridge of a specific color corresponding to the specific color of the plurality of replenishing means can be coupled. Or the multicolor image forming apparatus according to item 2.