JPH0361963A - Electrophotographic image forming device - Google Patents

Abstract

PURPOSE:To easily, surely, and efficiently carry out the maintenance and checking of a photosensitive body and a developing unit by separately providing a drum cartridge, a color development cartridge housing plural color developing units, and a black development cartridge housing a black developing unit. CONSTITUTION:The device is separately provided with the photosensitive drum cartridge 500 including a cleaner 100, an electrifier 20, a pre-electrifying electrode 90, a toner recovering part 130, etc., the color development cartridge housing the developing units 611A - 611C which contain the developers of yellow, magenta and cyan, and serve as a developing means, and a black development cartridge housing the black developing unit 611D. Thus, the units having almost the same using frequencies are collected, and constitute a unit incorporating a cartridge. Thus, the services such as checking, cleaning, replacing are correctly and easily carried out, and furthermore, the photosensitive body 10, the developing unit 600, and the cleaner 100 are used until their service lines are expired.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a cartridge for an electrophotographic image forming apparatus capable of forming a color image, in which a photoreceptor drum and a developing device are made removable and installed in the image forming apparatus. The present invention relates to an improvement to facilitate cleaning and inspection of a cartridge, and to ensure that it is easily replaced with a new cartridge upon expiration of a prescribed number of image formations.

[Conventional technology]

Conventionally, in electrophotographic image forming apparatuses, a photoreceptor drum and a developing device are included in one removable unit, or one unit including the photoreceptor drum and one unit including the developing device, respectively. Some were constructed into removable units. The electrophotographic image forming apparatus is configured so that internal inspection, parts replacement, and cleaning can be performed easily and reliably.

There is a limit to the number of times a photoreceptor can be used repeatedly for image formation, and it has become common to replace it with a new one at a usage limit of 10,000, 30,000, or 50,000 times. There is a limit to the number of times a product can be used, so it was often replaced with a new one.

[Problem to be solved by the invention]

The photoreceptor and the developing device have a durability limit for maintaining good image formation, and this limit is determined particularly by the number of times they are used for image formation. That is, since the photoreceptor suddenly loses its force when the limit number of times is reached, it is replaced with a new one before the force is reduced.

By the way, in the case of developing devices, even if the maximum number of times for each of the Y, M, C, and BL developing devices is the same, in a multicolor image forming apparatus, the frequency of use of each developing device is different, so that the limit cannot be achieved. It is normal for the timing to be different. In particular, there are cases where black is used most frequently and color is used less frequently, and in such cases, each color developer that uses each color developer may be integrated in accordance with the life limit of the black developer. If you judge that the lifespan has reached the limit and discard black and each color together, the developer for each color will be disposed of even though it still has sufficient usable capacity, and the color developer will become obsolete. This is very undesirable as it causes economic waste in terms of resources and developing devices for each color.

By the way, Y and M in multicolor image formation.

It appears that the frequency of use of each of the three color developers C, B, G, and R is almost the same.

The present invention solves these problems by combining frequently used functions into a cartridge-containing unit, allowing operations such as inspection, cleaning, and replacement to be performed accurately and easily. The object of the present invention is to provide an electrophotographic image forming apparatus that can be utilized for long periods of time and creases.

[Means to solve the problem]

The purpose of this is to provide an electrophotographic image forming apparatus capable of forming color images with a drum cartridge containing a photosensitive drum, a color developing cartridge containing a plurality of color developing devices, and a black developing device containing a thermal developing device. This is achieved by an electrophotographic image forming apparatus characterized in that a developing cartridge is provided separately.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 to 4.

1 and 2 are side sectional views showing the structure of the electrophotographic image forming apparatus of the present invention, and FIG. 1 is also a cross-sectional view taken along line xx' in FIG. It also represents a diagram.

In the figure, lO is a drum-shaped image carrier, ie, a photosensitive drum, which is driven and rotated clockwise in FIG. 2 and counterclockwise in FIG. Reference numeral 20 represents a charging electrode that applies an electric charge to the photoreceptor on the circumferential surface of the photoreceptor drum 10, and 30 represents a laser writing system unit that is an exposure optical system.

When a laser writing signal is input to the laser writing system unit 30, in the laser writing system unit 30, a laser beam generated by a semiconductor laser (not shown) is applied to a polygon mirror 3 rotated by a drive motor 31.
2, the optical path is bent by three mirrors 34A, 34B, and 34G through an fθ lens 33, and the image is projected onto the peripheral surface of the photoreceptor drum IO to which a charge has been previously applied by the charging electrode 20. .

On the other hand, when scanning is started, the laser beam is detected by the index sensor, modulation of the laser beam by the first color signal is started, and the modulated laser beam scans the circumferential surface of the photoreceptor drum 10. Therefore, a latent image of the first color is formed on the circumferential surface of the photosensitive drum 10 by the main scanning by the laser beam and the sub-scanning by the rotation of the photosensitive drum 10. This latent image is developed by a developing means containing a developer of, for example, yellow as a first color, and a yellow toner image is formed on the circumferential surface of the photosensitive drum 10. The obtained toner image is held on the circumferential surface of the photosensitive drum 10, and then passes under a cleaning means that is separated from the circumferential surface of the photosensitive drum 10, and enters the next copy cycle.

That is, the photosensitive drum 10 is charged again by the charging electrode 20, and then the second
A color signal of
Writing is performed on the peripheral surface using the second color signal to form a latent image. The latent image is developed by a developing means containing developer of a second color, for example magenta.

This magenta toner image is formed over the previously formed yellow toner image.

The f-toner image thus obtained is placed on the photosensitive drum 10.
It passes under the cleaning means which is separated from the circumferential surface of the photosensitive drum IO while being held on the circumferential surface, and enters the next copy cycle.

Similarly, writing is performed on the photosensitive drum 10 using the third color signal to form a latent image. This latent image is developed by a developing means containing a developer of a third color, for example cyan. This cyan toner image is formed superimposed on the yellow magenta toner image described above.

As described above, a color toner image is formed on the photoreceptor drum IO using the three color toners, but a high-quality color image can be obtained by further overlapping a black toner image in the same manner.

Reference numerals 611A, 611B, 611C, and 611D are developing units that are developing means that contain yellow, magenta, cyan, and black developers, respectively, for performing the above-mentioned development.

As shown in the example of the developing device 611A, each of the developing devices includes a developing σ-ra (developing sleeve) 612 having a magnetic pole fixed on the inside facing the circumferential surface of the photoreceptor drum IO with a predetermined gap therebetween; It is equipped with a pair of stirring rollers 6) 4 and 615 having conveying forces in mutually opposite directions, and the stirring roller 614
The developer is supplied to the circumferential surface of the rotating developing roller (developing sleeve) 612 after the toner and carrier components are made uniform by the mixing action of and 615.

A direct current or even alternating current bias is applied to the developing roller (developing sleeve) of each developing device that carries developer.
Non-contact reversal development is performed using a two-component developer.

Charging by the charging electrode 20 provided on the photosensitive drum 10 and its periphery, exposure by the laser writing system unit 30 for each color, and developing units 611A, 611B, 6
The development processing by 11C and 611D is performed four times for each color, so that color toner images are formed on the circumferential surface of the photoreceptor drum 10 by overlapping.

Reference numerals 61 and 62 are a first paper feed roller and a second paper feed roller, respectively, which are in a constantly rotating state, and 71 and 72 are paper feed guides having an arcuate shape and a linear shape, respectively.

The recording paper is carried out one by one from the paper feed cassette, and is sent along the paper feed guide 71 by the first paper feed roller 61 to the U.
After turning, that is, turning upside down, the paper contacts the rising portion of the paper feed shutter S that quickly cuts the conveyance path of the paper feed guide 72 and temporarily stops. In this case, the second paper feed roller 62 continues to rotate by sliding the stopped recording paper over its surface.

When the paper feed shutter S retracts downward in synchronization with the rotation of the photoreceptor drum IO carrying the toner image, the recording paper is synchronized with the circumferential speed of the photoreceptor drum 10 by the frictional force of the second paper feed roller 62. and is fed to the transfer section t~.

Reference numeral 80 denotes a rotatable transfer roller, which is charged with a voltage applied thereto, and has a transfer section that transfers the toner image to the recording paper side via the conveyor belt 80B at the point of contact with the circumferential surface of the photoreceptor drum IO. Configure. Note that a conveyor belt 80B is stretched between the transfer roller 80 and a drive roller 80A that rotates counterclockwise. Transfer is performed while conveying the recording paper by -80B. Note that 80C is a cleaning means for cleaning the surface of the conveyor belt 80B.

Reference numeral 90 denotes a front charging electrode located upstream of the cleaning device #:, lOO, and the photosensitive drum 1 on which the toner image was transferred to the recording paper.
0 Charge to a state that makes it easy to remove residual toner on the peripheral surface.

100 is a cleaning device, 110 and 120 are a conductive bristle brush and a conductive collecting roller which are cleaning means of the cleaning device lOO, and 130 is a waste toner collecting section that stores the toner collected by the cleaning means.

The photosensitive drum 10 that has passed the front charging electrode 90 is brought into sliding contact by a signal from the control section, and the residual toner is removed by the conductive bristle brush 110, and the residual toner adhering to the conductive brush 110 is removed. is absorbed by the conductive collection roller 120 and then transferred to the waste toner collection section 1.
Sent to 30.

The waste toner collecting section 130 is provided with a waste toner sending rod 131 and a deformable toner collecting bag 132, and the residual toner, that is, waste toner sent by the collecting roller 120 is sent through the waste toner sending rod 131. Bag member 1
It is housed in 32.

The photosensitive drum lO whose circumferential surface has been cleaned in this way
is charged again by the charger 20 and starts forming a new image, and at the same time the conductive bristle brush 110 is released from the rubbing state.

On the other hand, the recording paper to which the toner image has been transferred in the transfer section is separated from the circumferential surface of the photoreceptor drum 10 and transferred to the fixing device 60.
will be sent to. Reference numeral 63 denotes a pair of heat rollers for fixing, and numeral 64 denotes a pair of paper ejecting rollers. The recording paper on which the toner is melted and fixed by the pair of heat rollers 63 is ejected from the fixing device by the pair of paper ejecting rollers 64.

Reference numerals 73 and 74 are paper ejection guides for guiding the recording paper ejected by the pair of paper ejection rollers 64 to the upper part of the main body of the apparatus. The sheets are discharged and stacked on the tray 75 with the surface facing downward.

Next, the configuration of the developing device 600 will be explained.

As described above, the device 600 includes a developing device 611A containing a Y (yellow) developer, a developing device 611A containing a M (magenta) developer, a developing device 611G containing a C (cyan) developer, and a developing device 611G containing a C (cyan) developer. It stands out from a developing device 6110 that accommodates a BL (black) developer. And the Y
, M, and C each have one cartridge frame 602.
is housed in the guide rail 71 to form a color developing device.
3A and 713B, and is set so as to be removable from an entrance/exit window 713 provided in a frame 701 of a clamshell opening/closing section 700 formed on the upper part of the base section 800 of the image forming apparatus 1. On the other hand, the black developer storage developing device 611D is installed along the guide rail 713G through the entrance/exit window 7.
13 and is set to be independently attachable and detachable to the opening/closing part 700.

Since the configuration of each of the four developing units is the same, the configuration of 611A will be explained. The aforementioned developing roller (developing sleeve) 612 and stirring rollers 614 and 615 are housed inside the container 603 of the developing device, and at both ends of the developing roller 612 there are outer diameter portions 6 that are a certain amount larger than the outer diameter of the roller 612.
13 are provided in the same manner. Also, on the right side of the container 603 is a gear train 630 for transmitting drive to each of the rollers.
A toner receiving port 62 is provided on the left side of the container 603.
1 is open.

Then, a spring 618 is applied along a rail 619 provided in the container 603 so as to close the receiving port 621.
A mouth opening/closing member 618 is provided which is biased by a guide bin 616.

The container is connected to the developing unit 611 by a spring 625 (this may be a plate spring or a helical spring).
A is the outer diameter portion 613 at both ends of the developing roller 612 and the photoreceptor 10
It should be pressed against the drawing. This allows the gap between the developing roller 612 and the photoreceptor drum 10 to maintain an optimum gap for forming a magnetic brush.

Next, the toner replenishment tank 200 and toner replenishment device 250
I will explain about.

As shown in FIG. 2 and FIG.
, M, C, and BL containers 201A of the same shape.

201B, 201C, and 201D are arranged in one row. Then, the gears 205A, 2 are driven by the drive motor 205.
06, 207, and each of the toner containers 20 through 208A.
The stirring shafts 1A, 201B, 201C, and 201D and the spiral rotating shaft 208 are made rotatable. The spiral rotating shaft 208 is connected to the toner supply port 20 of the tank 200.
9, and the supply conveyance port 209 has 272A,
The l end of each hose represented by 272B, 272G, and 272D is connected, and a flexible spiral member 271 connected to the spiral rotation shaft 208 is provided in the hose, and the spiral rotation shaft 20
8, the rotation is freely transmitted to the member 271 in the rotational direction of the shaft, and the toner is conveyed.

The other end of each hose is connected to an introduction pipe 259 to a distribution container 251 for each color toner of the toner replenishing device 250. A toner supply port 257 is opened in the container 251 . The container 251 is provided with a rail 254 and an opening/closing member 258 that slides on the rail 254. The opening/closing member 2 is provided with a bottle 252 and a spring 253 provided on an extension 251A at the bottom of the container 251.
58 is always biased to the right. The supply port 257 is normally closed and blocked by the port opening/closing member 258.

The bottom extension portion 251A of each distribution container 251 of this toner replenishing device is fitted with bottles 266, 267, and 264 that fit into long holes 708 and 709 provided in the frame 701 of the Talam shell opening/closing portion 700, and It is fixed by being combined with a bent portion 262 of a plate 261 that is slidable in the direction of the elongated hole.

On the other hand, the seven frames 701 of the Taramsiel opening/closing part 700 can be opened/closed by a rotary support shaft 702 fitted in a bearing part 802 provided on the frame 801 of the base part 800.

In addition, bottle fitting grooves 703A, 703B, 703G, 70
The cam lever 703 with 3D is the cam lever 703
Bins 704 and 705 fixed to the frame 701 of 00, the bin 266 fixed to the plate 261, and the base part 80
It is fitted with a bin 805 fixed to a frame 801 of 0.

When the Talam shell opening/closing part 700 is opened from the side view shown in FIG. 1 to the perspective view shown in FIG. When the long holes 708 and 709 are moved and those bottles are planted, the plate 261 moves to the left.

In this way, the dispensing container 252 of the toner replenishing section, which is fixed to the bent portion 262 of the plate 261 by the bottom extension 252A, can also be moved to the left. As a result, the container 252 is separated from the container 603 of the developing device, and the opening/closing member 258 closes the replenishment hole 257 by the biasing force of the spring 255 to prevent toner from spilling from the distribution container 251. .

On the other hand, the toner receiving port 621 of the container 603 of the developing device 600
The mouth opening/closing member 618 slides on the rail 619 by the biasing force of the spring 617 and is closed. And developing device 6
The toner in the container 603 of 00 is also prevented from spilling.

In this way, when the taram shell opening/closing section 700 is open, the toner supply section 250 moves backward and closes the supply port 257, and the toner receiving port 621 of the container 603 of the developing device 600 is also closed, so that toner spillage is automatically prevented. Completely prevented.

When the Talamusiel opening/closing section 700 is open in this manner, the cartridges consisting of the three color developing devices of Y, M, and C are integrated into one cartridge and are moved from the entrance/exit window 713 of the Talamusiel to the guide rail 713.
It can be easily attached and detached by being guided by A and 713B.

In addition, the developing device 611D for black developer is also installed independently as one cartridge in the frame 701 of the clamshell opening/closing part.
It is guided by the guide rail 713C of the entrance/exit window 713 to enable easy attachment and detachment.

Also, Cleaner 100. Charger 20. Front charge electrode 90. As shown in the perspective view of FIG. 4, the photosensitive drum cartridge 500, including the toner collecting section 130, etc., is also inserted into the guide rail introduction section 712A and the guide rail 712 when the clam/well opening/closing section is opened. The guide parts 510A and 510B on both sides of the cartridge 500 are guided along the guide parts 510A and 510B to facilitate attachment and detachment.
It can be set so that it fits in a predetermined position along 1.

Further, the leg portions 503 and 504 of the cartridge are provided to facilitate inspection and cleaning when the cartridge 500 is pulled out from the clamshell opening/closing portion 700 and placed on an arbitrary table, making it easy to handle.

In this way, each cartridge can be easily installed and removed while the Talam shell opening/closing section is open for maintenance inspection, and it can also be easily replaced with a new one. Furthermore, by dividing the cartridge into three parts, it is no longer possible to load toner of each color in the wrong order. This is especially true not only for full-color images but also for multi-color images.In addition, by attaching and detaching the drum cartridge containing the photoreceptor drum and the developer cartridge orthogonally to each other, the loading and assembly operation is safer and more reliable than parallel loading. It became a thing. In particular, the structure is simpler if the photoreceptor cartridge is attached and detached before the developer cartridge is attached and detached than if it is done the other way around. This is because if the process is carried out in the reverse order, it is necessary to construct a configuration in which the developing roller and the like are removed so that the surface of the photoreceptor is not scratched during attachment and detachment of the developing device. Although this does not make the structure that complicated, it is preferable to have a method that does not require such measures.

In this embodiment, each toner replenishment tank 200 and each toner replenishment device 250 are attached to each developing device, but the toner replenishment tank 200 and toner replenishment device 250 are not provided separately. First, it is possible to store toner in the developing device for the life of the developing device, and when it is used up, discard the existing developing device along with the cartridge and replace it with a new developing device in a new cartridge.

Although each color developing device is placed in one cartridge and the black cartridge is placed in another cartridge, it is possible to consider the replacement period depending on the frequency of use. However, when used as a multicolor image forming apparatus, Depending on the user's usage, a certain color may be used more frequently,
In this case, it is also possible to configure a child cartridge among the cartridges so that the developer of that color can be replaced particularly quickly.

〔Effect of the invention〕

According to the present invention, it has become possible to easily, reliably and efficiently perform maintenance and inspection of photoreceptors and developing devices.

Further, after completing image formation on each of the functional means a certain number of times,
When the time comes to discard the cartridge, it is now possible to replace it with a new cartridge and restore functionality immediately. Moreover, since the operation was done through the simple and reliable method of replacing the cartridge, it was not necessary for a professional maintenance technician to do it.
It can now be easily handled by ordinary operators without requiring special skills. Furthermore, since cartridges can be replaced depending on the frequency of use, there is no wastage of expensive materials and there is an advantage that new replacements can be carried out in a reasonable manner.

[Brief explanation of drawings]

1 and 2 are perspective views of one embodiment of the present invention, and FIG. 4 is a perspective view of one embodiment of the present invention when the clamshell is opened. DESCRIPTION OF SYMBOLS 10... Photosensitive drum 11... Drum center pin 20... Charging device 30... Laser writing system unit 60... Fixing device 80... Transfer roller 90
. . . Pre-charger 100 . . Cleaning device 130 . . . Toner collection unit 200 .
04...Legs 510A, 510B...Guide portion 600...Developing device 602...Cartridge frame 611A...Y developer storage developing device 611B...M developer storage developing device 611C...・C developer containing developing device 611D...Black developer containing developing device 700...Taramusiel opening/closing part 701...Frame 702...Rotation shaft 71
2... Guide rail 713... Entrance/exit window 713A,
713B, 713G... Guide rail 800... Base Wf, 801... Frame 802...
・Bearing part

Claims (1)

[Claims] An electrophotographic image forming apparatus capable of forming a color image includes a drum cartridge containing a photosensitive drum, a color developer cartridge containing a plurality of color developing devices, and a black developing cartridge containing a black developing device. An electrophotographic image forming apparatus characterized in that it is provided separately.