JPH0387776A - Developing device - Google Patents

Abstract

PURPOSE:To eliminate developer leakage and the occurrence of picture quality deterioration even when the capacity of a developer container part is enlarged and developer quantity increases by partitioning the inside of the developer container part into closed spaces openable from outside. CONSTITUTION:As for a developing device provided with a developing part 30, which possess a developing sleeve 32, and the developer container part 40 storing a developer, the developer container part 40 is partitioned into the closed spaces 45 and 46 openable from outside. Therefore, the pressure of the developer applied to the periphery of the developing sleeve 32 of the developing part can be minimized. Thus, even when the developer quantity of the developing device increases, the developer can be prevented from leaking from the periphery of the developing sleeve 32, and a time for rubbing the developing sleeve with the developer can be shortened, whereby the deterioration of the developer can be effectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a developing device for an image forming apparatus such as a copying machine or Busonta that employs electrophotography.

(Prior art) For example, when forming an image using a copying machine, a photosensitive drum, which is a negative-like charged image carrier, is exposed to image light based on an original image, and an fnit latent image is formed on the photosensitive drum. Then, the electrostatic latent image is developed using a developer (toner), and a
Is it necessary to convert it into an i-image and turn it into a toner image?

As described above, the developing device has the function of supplying toner to the electrostatic latent image on the photosensitive tram and converting the electrostatic latent image into a toner image. An example of such a developing device will be described with reference to FIG. 12. The developing device 100 is disposed close to the photosensitive drum 200.

Developing unit ll that supplies toner t toward the photosensitive drum 200
The developer container 120 holds a certain amount of toner t and supplies the toner t to the developing section 110.

The developer fI1 section 110 has the developer sleeve 1 in the developer section main body 111.
12. Developing blade 113. )-ner blowout prevention member 1
14, etc., and the developing sleeve 112 has an immovable magnet roller inside.
Toner t is applied to the outer surface of the magnet roller by the magnetic force of the magnet roller.
By attracting the toner t and rotating in the direction of the arrow shown in the figure, the toner t is supplied to the opposing photosensitive drum 200. The developing blade 113 is disposed with a certain gap between it and the upper part of the developing sleeve 112, and the toner t on the developing sleeve 112 coming out from the developing section main body 111 is removed.
This is to adjust the thickness to a constant value. The toner blow-out prevention member 114 is for closing the gap between the lower part of the developing sleeve 112 and the developing section main body 111, and one end rubs against the developing sleeve 112 to prevent the toner t in the developing section main body 111 from flowing outside. Prevents leakage. Incidentally, the gap between the developing blade 113 and the developing sleeve 112 is sealed by a magnetic seal by accumulation of toner t.

The developer container silver 120 is located in the developing unit main body 111 of the developing unit 110.
extends upward as it is, and a guide section 121 is formed at the border with the developing section 110, and a sealing member 122 is disposed on the guide section 121. and developing device 10
The toner t in 0 is hermetically stored in this developer container silver 120 via this sealing member 122, and the toner t in the developing device l
When handling the OO, the internal toner t is released into the developing section 110.
This prevents leakage to the outside through the . When the developing device 100 is installed alone in the apparatus main body, or once installed in a process cartridge in consideration of ease of maintenance, and then installed in the apparatus main body via the process cartridge, the developing device The seal member 122 of 100 is removed to the outside.

On the other hand, there is a strong desire to retain as much toner t as possible in the developing device 100 in order to lengthen the time required to replace the developing device 59100 itself and the process cartridge and to reduce maintenance costs. Therefore, it is desirable to increase the size of the developer container 120 of the developing device 100.

(Problem B to be Solved by the Invention) However, in the developing device as shown in FIG.
In this case, as the developer container silver 120 becomes larger, the weight of the toner t applied to the developing sleeve 112 of the developing section 110 also increases, and the magnetic seal around the developing sleeve 112 increases. There was an inconvenience that the toner t leaked out from the part and the part of the toner blow-out prevention member 114.

In addition, in the case where the developing device 100 includes a stirring member and moves the toner t in the developer container silver 120 toward the developing section 110 via the stirring member, this stirring member and the photosensitive tram 200 are the same. Many of them are driven by a drive source, so if the developer container 120 becomes larger and the amount of toner t increases, the load acting on the stirring member increases, which impedes the rotation of the photosensitive drum 200. , the photosensitive drum 200
There was also the inconvenience that an image defect occurred in the upper image.

The present invention has been made in view of the above-mentioned problems, and its object is to solve the problem even when the capacity of the developer container increases and the amount of developer in the developer container increases.

To provide a developing device that does not leak developer and cause no deterioration in image quality.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a developing section that is installed in a process cartridge or is detachably attached to an image carrier by itself, and that has a developing sleeve inside. A developing device having a developer container for storing a developer is characterized in that the inside of the developer container is divided into a plurality of closed spaces that can be opened from the outside.

(Function) Even when the developer container of the developing device is enlarged to increase the amount of developer inside, the developer container is divided into multiple closed spaces that can be opened from the outside, so the development area can be easily The pressure of the developer applied around the developing sleeve can be kept low, and leakage of the developer from around the developing sleeve can be prevented.This also makes it possible to reduce the load torque for rotating the developing sleeve. In addition, the time during which the developer rubs against the developing sleeve can be shortened, and deterioration of the developer can be prevented. Even in the case where the agitating member is moved in the opposite direction and is driven by a common drive source with the image carrier, the amount of developer around the agitating member can be reduced, and the load on the agitating member can be reduced. This makes it possible to ensure proper image formation by the image carrier.

In addition, if the developer in the closed space inside the developer container is used up, 1
The developer in the next closed space may be supplied to the developing section.

(Example) An example of the present invention will be described below with reference to the accompanying drawings, taking a printer as an example.

First, a first embodiment of the present invention will be explained with reference to FIGS. 1 to 7.

First, the overall structure of the printer will be explained with reference to FIG. 1. In FIG. 1, 10 is a photosensitive drum which is an image bearing member that rotates in a fixed direction. - A secondary charger 13, a developing device 14, a transfer charger 15 are provided, and the photosensitive drum lO
A cassette 16, a paper feed roller 17, and a registration roller 18 are arranged on the paper feed side of the photosensitive drum IO, and a fixing device 19 is disposed on the paper discharge side of the photosensitive drum IO. A paper discharge tray 20 is also provided.

An optical scanning unit 212 and a reflective mirror 22 are disposed in the upper part of the apparatus main body l above the photosensitive drum lO, and image light emitted from the optical scanning unit 21 is exposed onto the photosensitive drum 10 via the reflective mirror 22.

That is, when the optical scanning unit 21 exposes the photosensitive drum 10, which has been uniformly charged by the negative charger 13, an electrostatic latent image is formed on the photosensitive drum 10. As the photosensitive drum IO rotates, the electrolytic latent image is directed toward the developing device 14, where it is developed and visualized and converted into a toner image. The toner image is directed toward the transfer charger 15 as the photosensitive tram 10 rotates, and is transferred onto the transfer paper P by the transfer charger 15. Further, the transfer paper P taken out one by one from the cassette 16 via the paper feed roller 17 is sent to the registration roller 18, and is conveyed toward the photosensitive drum 10 at the same timing by the registration roller 18. The transfer paper P onto which the toner image on the photosensitive tram 10 has been transferred by the transfer charger 15 is transferred to the fixing device 19.
After the toner image is fixed as a permanent image on the transfer paper P by the fixing device 19, the aJ!
be done. Incidentally, the photosensitive drum 10 after the transfer is cleaned of residual toner by a cleaning device 11.
Thereafter, the charge is extinguished by the pre-exposure lamp 12, and the image is placed on standby for primary image formation.

Here, the photosensitive tram 10. The cleaning device 11, secondary charger 13, and developing device 14 are integrally assembled within a cartridge container 23a, and are integrally removable from the apparatus main body l as a process cartridge 23.

This is to avoid the trouble of replacing the above-mentioned process equipment due to the lifespan of each individual equipment, and to facilitate maintenance by replacing a plurality of process equipment as one unit. Therefore, for example, if the developer (toner) in the developing device 14 is used up, the entire process cartridge 23 including the developing section 5114 will be replaced with a new process cartridge 23.

Next, as shown in FIGS. 2 to 5, the developing section 71 according to the present invention
4 will be explained in more detail.

Although FIG. 2 shows that the developing device i14 is installed in the cartridge container 23a of the process cartridge 23, the process cartridge 23 is not yet installed in the main body l of the apparatus and is in a freely portable state. It shows that there is.

Now, as is clear from FIG. 2, the developing device 14 is composed of a developing section 30 that performs a developing operation on the photosensitive tram IO, and a toner container section 40 that supplies toner t to the developing section 30. . The developing section 30 includes a developing section main body 31, a developing sleeve 32, a developing plate 33. Toner blowing member 34
etc., and the developing sleeve 32 is mounted on the stage section 31 of the developing section main body 31 near the photosensitive drum 10.
It is made up of a cylindrical member that is assembled above a to be rotatable in a certain direction, and has an immovable magnetic roller inside, and the toner t in the developing section main body 31 is magnetically attracted to the outer surface of the cylinder. Rotate.

The toner t is provided to the photosensitive drum 10. The developing blade 33 is attached to the developing unit main body 31 above the developing sleeve 32, and has a certain gap K between it and the developing sleeve 32, and forms the toner t magnetically attracted around the developing sleeve 32 to a certain thickness. It has the function of moving toward the photosensitive drum 19 while regulating the movement.

Further, the toner blowout prevention member 34 is made of PET, Mylar,
It is made of a soft sheet-like member such as FEP, one end of which is attached to the stage section 31a of the developing section main body 31,
The other end is in sliding contact with the developing sleeve 32, and the developing sleeve 3
It has the function of preventing the toner t from leaking outside from the gap between the lower part of the developing section 2 and the stage section 31a of the developing section main body 31. Incidentally, since a specific magnetic pole is provided above the magnet roller in the developing sleeve 32, spikes of toner T are formed in the gap K between the developing sleeve 32 and the developing section 33, and a magnetic seal is placed in this gap. has been done.

The toner container section 40 is disposed on one side of the developing section 30 so that the end shape of the developing section main body 31 of the developing section 30 is extended with the same size. 1, this toner container section 40 is positioned above the developing section 30, so that the toner t in the toner container section 40 can move toward the developing section 30 by its own weight. The angle of inclination of the toner container 40 with respect to the horizontal must be larger than the angle of repose of the toner t when the toner t is moved by its own weight.
For example, in the case of a one-component magnetic toner t with a particle size of about 10 μm, the angle needs to be 45 degrees or more.

A first guide portion 41 that slightly protrudes inward in the same direction is provided at the boundary between the toner container portion 40 and the developing portion 30.
A first handle member 47 made of a sheet-like member such as polyester or polypropylene is adhered inside the guide portion 41 to partition the toner container portion 40 into a closed space from the developing portion 30 . Further, a second guide portion 43 similar to the first guide portion 41 is provided also in the longitudinally intermediate portion of the toner container portion 40, and the second guide portion 43 is made of a member similar to the first seal member 42. second seal member 4
4 is attached to the toner container section 40, and the toner container section 40 is attached to the two first toner containers 40 having substantially equal capacities. It is divided into 45 and 46 second closed spaces.

And that's the first part. The second closed spaces 45 and 48 are each filled with toner t, and the first and second closed spaces 4
The filling amount of each toner t in 5.46 is the amount of filling of each toner t in the developing device 14 of an image forming apparatus capable of printing on A4 size transfer paper P.
For example, if the width shielded by the developing sleeve 32 of the developing section 30 is about 23cm wide,
Approximately less than 0 grams is appropriate. Then, the first and second seal members 42,44 are inserted into the first and second closed spaces 45,48 from outside the developing device 14 so that the toner t in the first and second closed spaces 45,48 can move toward the developing section 30. They can be peeled off along the second guide portions 41 and 43, respectively. This state is shown in a perspective view in FIG. 3, in which the first . At one end of the second seal material 42 and 44, there is a first seal. The second handle members 47 and 48 are attached, but since the first handle member 47 is disposed so as to cover the second handle member 48, the first handle member 47 is pulled in the direction of the arrow shown in the figure, and the first handle member 47, 48 is attached. The second handle member of the second seal member 44 cannot be pulled out until after the seal member 42 has been peeled off. Therefore, the second seal member 44 cannot be peeled off until after the first seal member 42 has been peeled off.

Here, the first and second guide parts 41.43 and the first and second
Details of the sealing members 42 and 44 First guide part 41
13 and 14 taking the first seal member 42 as an example.
To explain with the drawing, the first guide part 41 is composed of two guide plates 41a and 41b having the same opening A, and the first guide part 41 is sandwiched between the guide plates 41a and 41b.
A handle member 47 is provided. The first sealing member 42 is attached around six openings of the guide plate 41a so that it can be easily peeled off (the area marked with diagonal lines B in Fig. 1.3), and one end thereof is attached at a 180 degree angle at the folded portion 42a. The first handle member 4 is folded back and protrudes outward from the guide plates 41a and 41b.
It is connected to 7. The guide plate 41b is attached close to the folded portion 42 of the first seal member 42 so that the first seal member 42 can be easily peeled off.

In the developing device 14 shown in FIG. 2, the toner t is stored in the first toner container 40. Since the second closed space 45 and 46 are in a sealed state, the developing device 14 is
The toner t inside will not leak outside.

When installing the process cartridge 23 incorporating one or more developing devices 14 into the main body of the apparatus, first, the first sealing member 42 of the developing device 14 is peeled off as shown in FIG. The toner t in the first closed space 45 can be moved toward the developing section 30 by its own weight. Then, this process cartridge 23 is attached to the apparatus main body 1.
If the toner t is installed inside the first closed space 45 of the toner container section 40, it will move toward the developing section 30 by its own weight, but the toner t that has moved toward the developing section 30 will be moved toward the developing section 30. It gathers around the developing sleeve 32 and presses the magnetic seal part and the toner blow-out prevention member 34 formed in the gap between the developing sleeve 32 and the developing blade 33, and together with the impact force applied when the process cartridge 23 is installed, the developing device 1
However, since the amount of toner t in the first closed space 45 is not so large,
The toner pressure applied around the developing device 14 is not so large, and the toner t does not leak out of the developing device 14.

The developing device 14 inside this process cartridge 23
When the toner t in the developing section 30 and the first closed space 45 of the toner container section 40 is consumed and disappears, the process cartridge 23 is pulled out into the apparatus main body 1 and the developing section! 1
As shown in FIG. When installed in the apparatus main body l, the toner t in the second closed space 46 of the toner container section 40 moves toward the developing section 30. In this case as well, the toner t does not leak outward from the developing device 14, as in the case where the toner t in the first closed space 45 is moved toward the developing section 30.

As is clear from the above explanation, even if the capacity of the toner container section 40 of the developer IJI 14 becomes large, the toner container section 40
By dividing the interior into a plurality of closed spaces via the seal blades 44, a large amount of toner t is prevented from moving around the developing sleeve 32 of the developing section 30, and an increase in toner pressure around the developing sleeve 32 is prevented. Therefore, leakage of the toner t from around the developing sleeve 32 can be prevented, and the rotational load torque of the developing sleeve 32 can also be reduced. In addition, since the amount of toner t around the developing section 30 can be limited, the toner t can be transferred to the developing sleeve 32.
It is possible to shorten the time of rubbing and toner t.
It can also prevent deterioration.

Further, in the above embodiment, the toner container section 40 is partitioned into two in the longitudinal direction by the second sealing member 44, but the toner container section 40 is partitioned into two in the longitudinal direction.
As shown in the figure, the toner container section 40 is secured to the first and second closed spaces 45 and 46 by a blocking member 47 in its longitudinal direction.
A first guide part 41 disposed around the opening facing the developing section 30 of the first and second closed spaces of the partition 5 has a first part,
Even when the second seal members 42, 43 are provided, the same effect as in the above embodiment can be obtained by sequentially peeling off the first and second seal members 42, 43 and using the developing section W14. . The advantage of this configuration is that the seal member to be peeled off first may be either the first seal member 42 or the second seal member 42, 43. Therefore, complicated means for regulating the order in which the seal members are peeled off is not required.

Further, as shown in FIG. 7, in the developing device 14 that uses a two-part developer consisting of toner t and carrier C, the carrier C is magnetically attracted around the developing sleeve 32, and only the toner t is directed towards the photosensitive drum IO. is supplied to the developing device 1.
4 may cause deterioration of the carrier C or decrease of the carrier C, resulting in a decrease in the density of the toner image C on the photosensitive drum 10 or thinning of the lines.

Therefore, by mixing some of the replenishing carrier C into the toner in the second closed space 46 of the toner container section 40 of the developing device 14, it is possible to supplement the carrier C that has deteriorated and been consumed as described above.

Next, a wS2 embodiment of the present invention will be explained with reference to FIGS. 8 to 11. Components having the same functions as those in the first embodiment are designated by the same reference numerals, and their explanations will be omitted.

In the developing device 14 according to the first embodiment, the process cartridge 23 is installed in the device main body l.

The developing section 30 faces downward with respect to the toner container section 40,
Although the toner t in the toner container section 40 is supplied to the developing section 30 by its own weight, the device 14 according to the present embodiment has a structure in which the toner t in the toner container section 40 is supplied to the developing section 30 and the toner container section within the apparatus main body l. 40 are arranged horizontally, and the movement of the toner t from the toner container section 40 to the developing section 30 is performed by a stirring rod 48.degree. 48 that rotates in a fixed direction. In such a developing device 14, the toner pressure applied around the developing sleeve 32 of the developing section 30 decreases regardless of the amount of toner t, but the volume of the toner container section 40 increases and the toner container section 4
If there is a large amount of toner t in 0, the stirring rod 4
The load of 8.48 becomes large, and a problem arises in that image formation by the photosensitive drum 10 is not performed sufficiently.

In an image forming apparatus having a disposable type developing device 14, the driving source for the stirring rod 48, 48 in the toner container section 40 of the developing device 14 and the driving source for rotating the photosensitive drum 10 are common. In many cases, stirring bar 48.4
If the load on 8 increases, it will also affect the rotation of the outer photosensitive drum 10, resulting in a problem that image formation by the photosensitive drum 5 will not be performed with high precision.

In order to solve the above problem, in the developing device 14 of this embodiment as well, the toner container section 40 is connected to the wS2 guide section 43.
The space is divided into two upper and lower closed spaces 45 and 46 by a second sealing member 44, and a large amount of toner is not stirred at once by stirring rods 48 and 48.

When installing the process cartridge 23 incorporating the developing device 14 into the main body l of the apparatus, as shown in FIG.
The toner t in the first closed space 45 of the toner container section 40 is partially moved toward the developing section 30 by its own weight. Next, this process cartridge 23 is attached to the main body l of the apparatus.

When image formation starts around the photosensitive drum 10, the two stirring rods 48, 48 rotate in the direction of the arrow shown in the figure to move the toner t in the first closed space 45 of the toner container section 40 toward the developing section 30. move it. Here, since the toner container section 40 is divided into two, there is no need to stir a large amount of toner t at once with this stirring rod 48.48, and the load on the stirring rod 48.48 does not increase. The rotation of the photosensitive drum IO is not adversely affected.

Subsequently, when the toner t in the first closed space 45 is consumed and reduced, the process cartridge 23 is removed from the apparatus main body 1, the second seal member 44 of the developing device 14 is peeled off, and the toner The toner t in the second closed space 46 of the container section 40 may be made movable toward the developing section 30.

Above 1st. In the second embodiment, the case where the developing device 14 is incorporated in the process cartridge 23 has been described, but the case is not limited to this, and the case where the developing device 14 can be attached and detached by itself around the photosensitive drum 10 of the apparatus main body 1 is also applicable. Of course, you can think of it in exactly the same way.

(Effects of the Invention) As is clear from the above description, according to the present invention, even if the amount of developer in the developing device increases, the developer container holding the developer is divided into a plurality of closed spaces. The pressure of the developer applied to the developing sleeve can be reduced, and leakage of the developer from around the developing sleeve can be prevented. In addition, the rotational load torque of the developing sleeve can be reduced, and the time during which the developer is rubbed against the developing sleeve can be shortened, and deterioration of the developer can be effectively prevented.

Furthermore, in the above case, even if the developer container includes an agitating member that moves the developer toward the developing section and is driven by a common drive source with the image carrier, the surroundings of the agitating member may be affected. Since the amount of developer can be reduced, an increase in the load on the stirring member can be suppressed, and proper image formation by the image carrier can be ensured.

4. Brief description of the drawings FIG. 1 is a longitudinal sectional view of an image forming apparatus (printer), FIG. 2 is a sectional view of a developing device according to the first embodiment, and FIG. 3 is a perspective sectional view of the developing device. 4 and 5 are diagrams for explaining the operation of the same developing device, FIG. 6 and 7 are sectional views of the developing device according to a modified embodiment of the first embodiment, and FIG. 8 is a diagram for explaining the operation of the developing device. FIG. 9 is a perspective sectional view of the developing device according to the embodiment, FIG. 10 and FIG. 11 are diagrams for explaining the action of the developing device 11M, and FIG. 12 is related to the prior art. FIG. 13 is a diagram for explaining the developing device, and FIG. 13 is a perspective view showing a state in which the first seal member is attached to the first guide portion.
The figure is a cross-sectional view of the first seal member attached to the first guide part.

DESCRIPTION OF SYMBOLS 10... Photosensitive drum (image carrier), 14... Developing device, 23... Process cartridge, 30... Developing section, 32 Developing sleeve, 40... Developer container silver, 45
．． 46...1st. Second closed space (closed space).

Claims (1)

[Claims] In a developing device that is installed in a process cartridge or is detachably attached to an image carrier, and has a developing section having a developing sleeve inside and a developer container storing developer, the inside of the developer container section is A developing device characterized by being divided into a plurality of closed spaces that can be opened from the outside.