JPH06186843A - Developing device and process cartridge provided therewith - Google Patents

Abstract

PURPOSE:To prevent the floccurated coarse powder of developer from being produced by arranging a 1st stirring member and a 2nd stirring member coupled with the 1st stirring member through a soft deforming member in a container storing the developer. CONSTITUTION:Magnetic toner T is stored in the container 18. The 1st stirring member 22 performing pendulum motion with a shaft 20 as center, and the 2nd stirring member 23 moving back and forth along the bottom part 24 of the container 18 are arranged in the container 18. The 1st and the 2nd stirring members 22 and 23 are coupled through the flexible soft member 21. The material of the 1st and the 2nd stirring members 22 and 23 is a hard synthetic resin such as acrylonitrile butadiene-styrene copolymer. A soft coupling part 21 is a soft synthetic resin such as polypropylene. The soft coupling part 21 is fixed in the respective ends of the 1st and the 2nd stirring members 22 and 23 in a fitting and press-injecting system. Since there is no sliding hinge part, the coarse powder of the toner is not produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying apparatus, an electrostatic recording apparatus and a laser beam printer, and more particularly to an improvement of a mechanism for stirring a developer in a developing apparatus.

[0002]

2. Description of the Related Art Generally, a toner accommodating container 18 of a developing device is provided with a stirring rod for preventing a toner cross-linking phenomenon or for conveying the toner to a developing sleeve. -To eliminate the space), a stirring bar as shown in Figs. 7 and 8 has been devised.

The photosensitive drum 16 is in the A direction and the sleeve 2 is in the B direction.
When rotated in the direction, the first stirring member 34 rotates in the direction C. Then, the second stirring member 36 reciprocates along the bottom surface of the container 18 as indicated by the arrow D by the rotation of the hinge portion 35, and as shown in FIG. 7, there is almost no dead space in which toner remains. Lost.

However, in the hinge portion 35, the first
By the sliding of the stirring member 34 and the second stirring member 36, the toner may be pressed and slid to agglomerate to become a large coarse powder.

The large-sized coarse particles are clogged between the blade 1 and the sleeve 2 which regulate the toner layer thickness on the sleeve 2 supplied to the drum 16, and the sleeve 2 at the clogged point.
Since the amount of toner coating on the upper part is reduced and the amount of toner to be developed is reduced, white lines are formed on the solid black image. In addition, many white streaks due to the clogging of coarse powder were generated at both ends of the image, which substantially coincide with the position of the hinge portion 25.

In particular, when a low melting point toner used for a film fixing device is used, the hinge portion 25 is heated due to the temperature rise in the device due to continuous printing especially in a high temperature environment of 35 ° C. or higher.
When the temperature is 50 ° C. or higher, the low-melting point toner is squeezed by the hinge portion 25 in a high temperature state, frequently agglomerating and binding to become a large coarse powder, and an accident frequently occurs.

The above-mentioned film fixing device is a heat-resistant fixing film that moves at the conveying speed of the recording material while being in contact with the toner image formed on the recording material such as paper, and heat is generated in pulses to generate heat. A fixed heating element that heats and melts an image through a fixing film, and a pressing mechanism that presses the heating film and a pressure roller with the fixing film sandwiched therebetween.

However, the above-mentioned fixing device has the advantages that heat loss is small and the warm-up time is extremely short, but in order to fully bring out this advantage, it depends largely on the characteristics of the toner. It is necessary to melt the toner instantly. That is, the toner for the conventional heat fixing roller system has a temperature required for fixing of 1
Although the temperature is 50 to 180 ° C., since the above-mentioned film fixing device has a small heat capacity, the fixing temperature which can be given at the time of start-up or during continuous printing is 120 to 150 at most.
Up to ℃. Therefore, the temperature is 120 to 1 which is lower than the conventional one.
A toner that fixes at 50 ° C. is required for this film fixing device, and this toner will be referred to as a low melting point toner.

However, such a low-melting point toner has a characteristic that even if the toner has a temperature lower than the fixing temperature, it is apt to aggregate when subjected to mechanical pressure.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a first stirring member and a second stirring member that reciprocates along the bottom surface of the container in cooperation with the first stirring member are arranged in a developer accommodating container. An object of the present invention is to provide a developing device capable of preventing the above-described aggregated coarse powder of the developer from being generated in the developing device, and a process cartridge including the developing device.

[0011]

A developing device according to the present invention comprises a first stirring member and a second stirring member connected to the first stirring member by a flexible deformation member in a container containing a developer. In the developing device, the first stirring member is pendulum-moved, and the second stirring member is reciprocally moved along the bottom surface of the container.

In the process cartridge of the present invention, the first stirring member and the second stirring member connected to the first stirring member by the flexible deforming member are arranged in the container containing the developer, and the first stirring member is arranged. The developing device is provided with a stirring member that makes a pendulum motion, and in conjunction with this, a second stirring member that reciprocates along the bottom surface of the container, and an image carrier that carries an electrostatic latent image developed by this developing device. The process cartridge is detachable from the main body of the image forming apparatus.

That is, in the present invention, the first stirring member and the second stirring member are connected by the flexible deforming member, and the pendulum motion of the first stirring member is transmitted to the second stirring member via the flexible deforming member. Since this motion transmission part does not have a sliding link part as in the prior art, even if a low melting point toner for a film fixing device is used, coarse powder is not generated in a high temperature environment, and the toner coat amount on the sleeve is Since it is not disturbed, it is possible to prevent a white streak image.

[0014]

EXAMPLE In FIG. 1, a magnetic toner T is contained in a container 18. The toner in the container 18 is carried out of the container 18 by the non-magnetic developing sleeve 2 that rotates in the arrow direction, and is applied to the electrostatic latent image formed on the electrophotographic photosensitive drum 16 that rotates in the arrow direction.

In order to regulate the layer thickness of the toner layer conveyed by the sleeve 2 to the developing area for developing the latent image, in the example of FIG. 1, the magnetic blade 1 is opposed to the sleeve 2 with a minute gap. Has been. The magnet 3 is fixed in the sleeve, and a thin layer of toner is formed by the magnetic field formed between the blade 1 and the magnetic pole of the magnet 3.

The blade 1 may be a non-magnetic blade, or an elastic blade may be pressed against a sleeve to regulate the toner layer thickness.

In the container 1, the first stirring member which performs a pendulum motion between the solid line position and the broken line position about the shaft 20 as shown by the arrow, and by being guided by the bottom portion 24 of the container 18,
A second stirring member 23 that reciprocates between a solid line position and a broken line position as indicated by an arrow is arranged along the container bottom 24.

The above-mentioned first stirring member 22 and second stirring member 2
As shown in FIG. 2, the member 3 is a member 2 that deforms flexibly.
1. In other words, they are connected by a flexible member 21 having flexibility.

In FIG. 2, the material of the first stirring member 22 and the second stirring member 23 is a hard synthetic resin such as ABS material (acrylonitrile / butadiene / styrene copolymer).
The flexible connecting portion 21 is a flexible synthetic resin such as PP material (polypropylene). The flexible connecting portion 21 itself is the first stirring member 2
The end of No. 2 and the end of the second stirring member 23 are fixed by a press-fitting method.

FIG. 5 shows an example of a mechanism for oscillating the first stirring member 22 (reciprocating swing).

A lever 25 is fixed to the shaft 20 to which the first stirring member 22 is fixed. An eccentric cam 27 that rotates in the direction of the arrow is in contact with the lever 25, and the lever 25 is constantly pressed against the eccentric cam 27 by a spring 26. Thus, the eccentric cam 27 rotates in synchronism with the rotation of the sleeve 2, whereby the first stirring member 22 makes a pendulum motion in the container 18, prevents the toner from being cross-linked, and sends the toner toward the sleeve.

The flexible connecting portion 21 itself bends or opens due to the pendulum movement of the first stirring member 22, and transmits the motive force of the first stirring member 22 to the second stirring member 23, and the second stirring member 23. 23 is interlocked with the pendulum motion of the first stirring member 21 to reciprocate back and forth. The reciprocating motion of the second stirring member 23 on the bottom surface inside the developing device 18 prevents toner cross-linking, and the low melting point toner is conveyed toward the sleeve 2 in spite of the fact that the inclination angle of the bottom surface is gentle. It That is, there is almost no dead space.

The toner sent to the vicinity of the sleeve 2 by the movement of the first and second stirring members 22 and 23 is magnetically attracted onto the surface of the sleeve 2 by the magnetic force of the magnet 3 in the sleeve.

Further, the first stirring member 22 and the second stirring member 2
Since there is no sliding hinge portion in the flexible connection portion 21 with the conventional three, coarse powder of toner is not generated, and the coarse powder is not clogged in the gap between the blade 1 and the sleeve 2. Since the toner coat amount of is also stable, white stripes do not occur in a solid black image.

Next, another embodiment of the present invention is shown in FIG.
In FIG. 3, the same elements as those shown in FIG. 2 are designated by the same reference numerals.

In the agitation of the embodiment shown in FIG. 3, in place of the thin plate-like flexible connecting member 21 of FIG.
Is used. Both ends of the thread 24 are fixed by binding to the members 22 and 23, respectively.

The thick thread 24 is also bent or opened by the pendulum movement of the first stirring member 22 to reciprocate the second stirring member 23 back and forth.

Further, the first stirring member 22 and the second stirring member 2
Since the thread 24, which is the connecting portion with the thread 3, has no sliding hinge portion as in the conventional case, coarse powder of the low melting point toner is not generated.

As the thick thread 24, the above-mentioned synthetic resin or a metal elastic wire material such as a piano wire can be used.

Still another embodiment is shown in FIG. still,
Also in FIG. 4, the same elements as those shown in FIG. 2 are designated by the same reference numerals.

In the stirring of the embodiment shown in FIG. 4, the material of the second stirring member 23 is AB instead of the flexible connecting member 21 of FIG.
The S material is changed to the PP material, and the connecting portion 29 is also integrally formed with the second stirring member 23.

The tip of the connecting portion 29 integrally extended from the second stirring member 23 is fixed to the first stirring member 22 by a fitting press-fitting method or by adhesion.

This flexible connecting portion 29 is also connected to the first stirring member 22.
The pendulum movement causes the second stirring member 23 to reciprocate back and forth by bending or opening.

Even in this example, since there is no sliding hinge portion, it is possible to prevent the generation of coarse powder toner.

Next, the process cartridge 101 provided with the developing device 102 will be described with reference to FIG.

By the way, the process cartridge 10
Reference numeral 1 denotes an electrophotographic photosensitive drum 16 that is an image bearing member that is rotationally driven in the direction of the arrow, a corona discharger 17 arranged around the photosensitive drum 16, a developing device 103, and a cleaning device 19.
Etc. are integrally incorporated into the support 20 to form a unit.

The process cartridge 101 is guided by a guide 30 provided on the main body 102 of the image forming apparatus 100, and is attachable to and detachable from the main body 102. Then, the process cartridge which has been consumed and consumed in the container 18 is replaced with a process cartridge in which the container 18 is filled with toner.

Next, the structure of the copying apparatus 100 shown in FIG. 6 will be outlined. The copying apparatus 100 is constructed by mounting the process cartridge 101 in the main body 102, and the optical system is provided above the process cartridge 101 in the main body 102. The short focus optical element array 4 and the platen illumination lamp 5 constituting the above are arranged, and a paper feed cassette 6, a paper feed roller 7, a paper guide member 8, a transfer corona discharger 9 and a paper A transport path 10 and a film fixing device 11 are sequentially arranged. A discharge tray 14 is provided outside the main body 102, and a document table 15 is provided on the upper surface.

Next, the operation of the copying apparatus 100 will be described.

The surface of the photosensitive drum 16 is a corona discharger 17.
Is uniformly charged, and the surface of the photosensitive drum 16 is irradiated with the original image on the original table 15 illuminated by the original table lamp 5 through the short focus optical element array 4, and the surface of the original image is illuminated. Is formed by the sleeve 2 of the developing device 103 and is visible as a developed image.

On the other hand, the transfer paper is taken out from the paper feed cassette 6 by the paper feed roller 7, and the taken out transfer paper is conveyed along the guide member 8 between the photosensitive drum 16 and the transfer corona discharger 9. Then, the developed image formed on the photosensitive drum 16 is transferred onto the transfer paper by the transfer corona discharger 9, and the transfer paper having the transferred developed image is sent to the film fixing device 11 via the transport path 10. Here, the development image is fixed. The paper on which the toner image is fixed is discharged to the tray 14.

In the film fixing device 11, reference numeral 12 denotes a low-heat-capacity linear heating element fixed to the apparatus. For example, an alumina substrate having a thickness of 1.0 mm, a width of 10 mm and a longitudinal length of 240 mm is provided with an electric resistance material. It is applied to 1.0 mm, and electricity is applied from both ends in the longitudinal direction. Direct current 10
A pulsed waveform having a cycle of 0 V and a period of 20 msec is applied by changing the pulse width according to a desired temperature and energy release amount controlled by a thermometer. The pulse width is approximately 0.5 to 5.0 msec.

As described above, the fixing film 13 moves together with the recording material at a substantially constant speed while contacting the heating body 12 whose temperature and energy are controlled. This fixing film 1
As an example of 3, a heat-resistant film having a thickness of 20 μm, such as polyimide, polyetherimide, PES, PFA
The endless film has a release layer of 10 μm coated with a conductive material added to a fluororesin such as PTFE or PFA on at least the image contact surface side. Generally, total thickness 100 μm
The following is more preferably less than 60 μm. The endless belt of the fixing film 13 is stretched around a driving roller 31 and a driven roller 32, and is smoothly moved by the rollers 31 and 32 and tensioned without endless wrinkles.

Reference numeral 33 denotes a pressure roller having a rubber elastic layer having a good releasability such as silicon rubber, which presses the heating body 12 through the fixing film 13 with a total pressure of 4 to 7 kg, and the fixing film 13 causes Hold the transfer paper and transport it.

The transfer paper moves substantially without sliding with the fixing film 13 and receives heat from the heating body 12 via the fixing film 13, whereby the toner is melted and fixed on the paper.

Since the toner image is fixed by the film fixing device 11 as described above, the toner container of the process cartridge 101 contains low melting point toner. As described above, the low melting point toner has a conventional toner fixing temperature of 150 when compared with the conventional heat roller type fixing device.
It can be fixed at 120 to 150 ° C. to ˜180 ° C. Therefore, it tends to be softer at lower temperatures than conventional toners. Therefore, when mechanically slid by a sliding hinge, aggregates (coarse particles) tend to be generated, but the stirring mechanism of the present invention can prevent this, and therefore the present invention is directed to development using toner for film fixing devices. It is especially useful for devices.

In the above embodiments, the magnetic toner (one-component magnetic developer) for the sheet fixing device is used as an example, but the present invention is also applicable to a developing device using a non-magnetic toner (one-component non-magnetic developer). Is available. The present invention is useful because the non-magnetic toner containing no magnetic fine powder has a lower melting point than the magnetic toner.

The present invention is also useful because the capsule toner for pressure fixing instead of heat fixing has a low melting point.

However, the present invention can also be applied to a developing device using a high melting point toner for fixing a heat roller. Coagulated coarse powder may be generated even in the high melting point toner, but according to the present invention, generation of the aggregated coarse powder in the stirring mechanism can be highly prevented.

[0050]

As described above, according to the present invention, in the developing device having the developer agitating means in the developer container, the flexible deforming member is used for the first agitating member which performs the pendulum motion.
By connecting the agitating member and driving the second agitating member so as to reciprocate along the bottom surface in the developer container, the coarse toner particles are removed at the connecting portion between the first agitating member and the second agitating member. Since no powder is generated and the toner coat amount on the sleeve is not disturbed, it is possible to prevent a white streak image.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a perspective view of a stirring mechanism according to an embodiment of the present invention.

FIG. 3 is a perspective view of another example of the stirring mechanism.

FIG. 4 is a perspective view of still another example of the stirring mechanism.

FIG. 5 is an explanatory diagram of an example of a drive mechanism.

FIG. 6 is an explanatory diagram of an example of an image forming apparatus that can utilize the present invention.

FIG. 7 is an explanatory diagram of a conventional example.

FIG. 8 is an explanatory view of a conventional stirring mechanism.

[Explanation of symbols]

 2 Development Sleeve 21 Flexible Deformation Member 22 First Stirring Member 23 Second Stirring Member

Claims (2)

[Claims] 1. A first agitation member and a second agitation member connected to the first agitation member by a flexible deformation member are arranged in a container containing a developer, and the first agitation member is pendulum-moved. , A developing device which reciprocally moves the second stirring member along the bottom surface of the container in conjunction therewith. 2. A first agitation member and a second agitation member connected to the first agitation member by a flexible deformation member are arranged in a container containing a developer, and the first agitation member is pendulum-moved. , A developing device that reciprocally moves the second stirring member along the bottom surface of the container in conjunction with it, and an image carrier that carries an electrostatic latent image developed by the developing device. Possible process cartridge.