JPH09190078A - Processing cartridge, developing device and electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly raise static charge of toner, in an initial step of developing means and at the time of the toner replenishment, and to always obtain an image of stable density. SOLUTION: This device main body is provided with counting means for integrating printing number of sheets, agitating bars 7a and 7b for agitating the toner in the developing device of a processing cartridge, and an antenna 8 for detecting the residual toner. A non-volatile recording medium 9 stores total printing sheet number and the presence or absence of the residual toner detecting signal, the agitating bars 7a and 7b are operated, based on these information. For instance, operation of the agitating bars 7a and 7b are stopped for a specific period at an initial stage of the device start up. Operating speed of the agitation bars 7a and 7b are made faster than the normal speed, during a period when residual quantity detecting signal is present. The operating speed of the agitation bars 7a and 7b are made faster than the normal speed, for the specific period after the residual quantity detecting signal is turned from ON to OFF.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, a process cartridge, a developing device, and an electrophotographic image forming apparatus to which the process cartridge or the developing device can be detachably attached.

Here, as an electrophotographic image forming apparatus, for example, an electrophotographic copying machine, an electrophotographic printer (for example, L
ED printers, laser beam printers, etc.), electrophotographic facsimile machines, and electrophotographic word processors.

Further, as the process cartridge, is the charging means, the developing means or the cleaning means and the electrophotographic photosensitive member integrally formed into a cartridge, and the cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus? Alternatively, at least one of the charging means, the developing means, and the cleaning means and the electrophotographic photosensitive member are integrally made into a cartridge so as to be attachable to and detachable from the main body of the electrophotographic image forming apparatus, or at least the developing means and the electrophotographic photosensitive member. It is a unit that can be attached to and detached from the main body of the electrophotographic image forming apparatus by integrally forming a cartridge with the body.

[0004]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is used as an image forming apparatus. A process cartridge system detachable from the main body is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a service person, so that the operability can be remarkably improved. Therefore, this process cartridge system
Widely used in image forming apparatuses.

In the electrophotographic image forming apparatus as described above, a charging means for uniformly charging the photoconductor drum around the photoconductor drum, which is an electrophotographic photoconductor, and a static charge on the photoconductor drum. An exposure device for forming an electrostatic latent image, a developing device for converting an electrostatic latent image into a visible image, a transfer device for transferring a visible image onto a transfer material that is a recording medium, and a photosensitive drum. It has a cleaning device for removing the residual toner, and also has a fixing device for fixing the visible image transferred to the recording medium.

As an example of the process cartridge, there is one in which the above-mentioned photosensitive drum, charging means, developing device, and cleaning device are unitized so that they can be replaced with respect to the main body of the device.

Further, the developing device is provided with a magnet roller therein, and the developing roller, which is a developer carrying member for conveying the toner, which is the developer, to the photosensitive drum by the magnetic force of the magnet roller, and the toner on the developing roller. Equipped with a developer control member to control the layer thickness, a hopper to store toner, a stirring mechanism to stir and convey the toner in the hopper, and a high pressure is generated to apply a bias to the developing roller. The circuit is connected.

In the schematic structure as described above, the electrostatic latent image formed on the photosensitive drum by the exposure device is visualized as a toner image by the developing device, transferred to the recording medium by the transfer device, and then fixed. Transported to the device. Then, after the toner image is fixed on the recording medium, the sheet is ejected out of the apparatus by the conveying means. The toner remaining on the photosensitive drum without being transferred is removed by a cleaning blade and stored in a waste toner container.

Further, in the above apparatus, when the toner in the hopper is consumed, the toner is replenished from the replenishing port,
Image formation can be continued.

[0010]

The present invention is a further development of the prior art.

Therefore, an object of the present invention is to provide a process cartridge, a developing device, which can quickly raise the charge amount of the toner at the beginning of use of the device or at the time of replenishing the toner, and which can always obtain an image having a stable density. And an electrophotographic image forming apparatus.

[0012]

The above objects can be achieved by an electrophotographic image forming apparatus, a process cartridge and a developing apparatus according to the present invention. In summary, the present invention relates to a process cartridge detachably mountable to the main body of an electrophotographic image forming apparatus, which contains an electrophotographic photosensitive member, a process unit including at least a developing unit that acts on the electrophotographic photosensitive member, and a developer. A developer accommodating portion, means for detecting the remaining amount of the developer in the developer accommodating portion, an agitation mechanism for agitating the developer in the developer accommodating portion, and a non-volatile memory capable of reading / writing information. Means, the electrophotographic image forming apparatus main body has counting means for accumulating the number of printed sheets, and the nonvolatile memory means stores the total number of printed sheets of the electrophotographic image forming apparatus and a residual amount detection signal of the developer. The presence / absence of the presence or absence is stored, and the operating condition of the stirring mechanism is changed according to the information of the nonvolatile storage means.

It is preferable to stop the operation of the stirring mechanism for a certain period from the initial use of the electrophotographic image forming apparatus. While the remaining amount detection signal is being output, it is preferable that the operating speed of the stirring mechanism be faster than usual. It is preferable that the operating speed of the stirring mechanism be higher than usual for a certain period after the remaining amount detection signal is turned off.

According to another aspect of the present invention, in an electrophotographic image forming apparatus in which a process cartridge can be attached and detached and which forms an image on a recording medium, (a) an electrophotographic photosensitive member and the electrophotographic photosensitive member Process means including at least a developing means, a developer accommodating portion for accommodating a developer, a means for detecting the remaining amount of the developer in the developer accommodating portion, and an agitation of the developer in the developer accommodating portion. The electrophotographic image forming apparatus main body has a stirring mechanism for carrying out the above, and a non-volatile storage means capable of reading / writing information.
The nonvolatile storage means stores the total number of printed sheets and the presence / absence of a developer remaining amount detection signal, and the operating condition of the stirring mechanism is determined by the information in the nonvolatile storage means. There is provided an electrophotographic image forming apparatus comprising: a mounting unit for removably mounting a process cartridge to be changed in a main body of the apparatus; and (b) a transporting unit for transporting the recording medium.

According to another aspect of the present invention, in a developing device having a developing means having a developer accommodating portion and detachable from the main body of the electrophotographic image forming apparatus, the developer in the developer accommodating portion is Of the remaining amount of the electrophotographic image forming apparatus, a stirring mechanism that stirs the developer in the developer accommodating portion, and a non-volatile storage unit that can read / write information. A total number of printed sheets of the electrophotographic image forming apparatus and the presence / absence of a developer remaining amount detection signal are stored in the non-volatile storage unit, and information of the non-volatile storage unit is provided. According to the present invention, there is provided a developing device characterized in that the operating condition of the stirring mechanism is changed.

Further, according to another aspect of the present invention, in an electrophotographic image forming apparatus equipped with a developing device of a type that replenishes the developer in a timely manner, counting means for accumulating the number of printed sheets and the developer of the developing device. The nonvolatile storage device includes a unit for detecting the remaining amount of the developer in the storage unit, a stirring mechanism for stirring the developer in the developer storage unit, and a nonvolatile storage unit capable of reading / writing information. The storage means stores the total number of printed sheets of the electrophotographic image forming apparatus and the presence / absence of a developer remaining amount detection signal, and the operating condition of the stirring mechanism is changed according to the information of the nonvolatile storage means. An electrophotographic image forming apparatus is provided.

[0017]

EXAMPLES Hereinafter, a process cartridge according to the present invention,
The developing device and the electrophotographic image forming apparatus will be described in more detail with reference to the drawings.

First Embodiment A first embodiment of an electrophotographic image forming apparatus having a developing device according to the present invention will be described with reference to FIGS.

In FIG. 1, the electrophotographic image forming apparatus as described above has a charging means 21 for uniformly charging the photosensitive drum 20 around the photosensitive drum 20 which is an electrophotographic photosensitive member. An exposure device 22 for forming an electrostatic latent image on the photosensitive drum 20, a developing device 1 for converting the electrostatic latent image into a visible image, and a transfer of the visible image onto a transfer material 25 which is a recording medium. And a cleaning device 29 for removing the residual toner on the photosensitive drum 30, and a fixing device 28 for fixing the visible image transferred to the recording medium 25. .

In the schematic structure as described above, the electrostatic latent image formed on the photosensitive drum 21 by the exposure device 22 is visualized as a toner image by the developing device 1, and transferred onto the transfer material 25 by the transfer device 27. Transferred, then fixing device 2
8. Then, after the toner image is fixed on the transfer material 25, the sheet is ejected out of the apparatus by the conveying means 50. The toner remaining on the photosensitive drum 20 without being transferred is removed by the cleaning blade 30 of the cleaning device 29 and stored in the waste toner container 31.

Further, in the above apparatus, when the toner in the hopper 3 which is the developer accommodating portion is consumed, the toner can be replenished from the replenishing port and the image formation can be continued.

Next, the developing device 1 will be described with reference to FIGS.
Will be further described with reference to the block diagram of FIG.

The developing device 1 comprises a developing chamber 2 and a hopper 3 for storing toner. The hopper 3 has a first stirring rod 7 for supplying the developer 6 in the hopper 3 to the developing chamber 2.
a, and a replenishment port (not shown) for replenishing the developer, which is provided on the upper part of the a, and the developing chamber 2 is a developing roller which is a developer carrying member disposed in the vicinity of the photoconductor drum 20. 4, an elastic blade 5 that is a developer regulating member that regulates the toner layer thickness on the developing roller 4, and a developer 6 in the developing chamber 2.
A second stirring rod 7b for stirring the toner, and an antenna 8 which is a conductive detection member for detecting the remaining amount of the developer 6 by the electrostatic capacitance detection method are provided. A high voltage generating circuit 24 for applying a bias is connected to the developing roller 23.

Of the two stirring rods for stirring and supplying the developer, the first stirring rod 7a is mainly from the hopper 3 to the developing chamber 2.
The second stirring rod 7b serves to feed the toner to the developing roller 2 by stirring the toner in the developing chamber 2.
It serves to prevent the toner in the vicinity from being stagnant. Also, the first
The stirring rod 7a always rotates at a constant speed in conjunction with the developing roller 4, and the second stirring rod 7b can rotate independently of the first stirring rod 7a by a motor.

Further, the developing device 9 is additionally provided with a non-volatile storage medium (hereinafter referred to as NVRAM) capable of reading / writing information.

As shown in the block diagram of FIG. 3, in the image forming apparatus of this embodiment, the NVRAM 9, the counting circuit 10 for accumulating the number of printed sheets of the image forming apparatus, and the antenna 8 are provided.
Circuit 11 for detecting the remaining amount of the developer by a signal from
A stirring drive motor 12 for driving the second stirring rod 7b,
And a CPU 13 which is an engine controller. The CPU 13 sequentially determines the number of prints of the image forming apparatus transmitted from the count circuit 10 and the presence / absence of the remaining amount detection signal transmitted from the remaining amount detection circuit 11 of the developer, NVRA.
The information stored in the NVRAM 9 and written in the M9 causes the stirring drive motor 12 to operate as described below.
Is controlled to operate the second stirring rod 7b.

The explanatory diagram of FIG. 4 shows the transition of the density of the image forming apparatus and the operating state of the stirring mechanism according to the present embodiment, the horizontal axis indicates the number of prints, A is the transition of the image density, and B is the image density.
Is the on / off state of the remaining amount detection signal, C is the second stirring rod 5b
The operating state of is shown.

Next, the specific control contents will be described with reference to FIG.

When the total number of printed sheets stored in the NVRAM 9 is, for example, 100 or less, the CPU 13 determines that the image forming apparatus is at the beginning of use and stops the rotation of the second stirring rod 7b (state 1).

By carrying out such control, the movement of the toner in the developing chamber 2 is temporarily stopped and the toner in the vicinity of the developing roller 4 is concentratedly charged, so that the toner on the developing roller 4 is charged. The charge amount of the toner can be quickly increased. Therefore, it is possible to accelerate the rise of the density in the initial use of the image forming apparatus.

After the total number of printed sheets reaches 100 or more,
When it is determined that the developing device is in a stable state, the second stirring rod 7b is caused to rotate normally (state 2).

When the image forming apparatus is used and the remaining amount detection signal is turned on, the CPU 13 determines that the remaining toner in the developing device is small, and sets the rotation speed of the second stirring rod 7b to normal. Make it faster (state 3).

By carrying out such control, the toner supply capacity of the second stirring rod 7b is increased, and the toner which has decreased can be effectively conveyed to the developing roller 4.
Even when the toner remaining amount is low, it is possible to prevent the density from decreasing.

When the user newly supplies toner by the notification of the toner remaining amount signal, the remaining amount detection signal is turned off. The CPU 13 determines that the toner has been replenished by the fact that the remaining amount detection signal is changed from the ON state to the OFF state, and the second stirring rod 7 is operated during the subsequent 100 sheets of printing.
The rotation speed of b is set higher than usual (state 4).

By carrying out such control, the toner stirring ability of the second stirring rod 7b is increased, and the old toner whose charging performance is deteriorated due to mechanical friction or the like is quickly mixed with the replenished new toner. It is possible to output an image having a stable density even after toner replenishment, which tends to make the density unstable.

As described above, in the electrophotographic image forming apparatus of this embodiment, the total number of printed sheets of the image forming apparatus and the presence / absence of the developer remaining amount detection signal are stored in the NVRAM,
By changing the operating condition of the stirring mechanism of the developing device according to the information, it becomes possible to always perform an appropriate stirring operation, and the stability of the density is improved.

In the present embodiment, the period during which the rotation of the second stirring rod 7b is stopped in the initial state of use is 100 prints, but this period is appropriately determined according to the size and shape of the developing device. , The value used this time is not particularly limited.

In this embodiment, the developing device having two stirring bars controls only the second stirring bar 7b, but the present invention is not limited to this structure.
The stirring bar 7a may be controlled similarly. In addition, even in a developing device with a single stirring rod, the same effects are obtained by performing the same control.

In the description of this embodiment, the developing device is fixed to the main body of the device.
Needless to say, the cartridge may be a cartridge in which the developing device can be attached to and detached from the apparatus main body when the components such as the developing roller reach the end of their lives.

Second Embodiment Next, a second embodiment of the electrophotographic image forming apparatus and the process cartridge according to the present invention will be described with reference to FIGS. In this embodiment, a photosensitive drum which is an electrophotographic photosensitive member, a developing means, an NVRAM for storing the number of printed sheets of an image forming apparatus and an output state of a remaining amount detection signal of a developer, and a process which acts on the photosensitive drum. A charging device or a cleaning device as a means is detachably attached to the main body of the electrophotographic image forming apparatus as a process cartridge.

In the description of this embodiment, the same members as those described above are designated by the same reference numerals, and the portions overlapping with those of the first embodiment are incorporated.

As shown in FIGS. 5 and 6, the process cartridge C of this embodiment is the same as the developing device 1 of the first embodiment except that the photosensitive drum 20, the charging device 21, and the cleaning device 29 are used.
Is an example of an integrated process cartridge. The process cartridge is equipped with a non-volatile storage means (NVRAM) 9 for storing the total number of printed sheets of the process cartridge itself and the output state of the developer remaining amount detection signal.

By mounting the process cartridge in the image forming apparatus by the mounting means 40, the NVRAM 9 of the process cartridge C is connected to the CPU of the image forming apparatus, and the CPU can write / read information in the NVRAM. Then, similarly to the case described in the first embodiment, the second stirring rod 7b is controlled based on the information.

By adopting the above configuration, the first embodiment
In addition to obtaining the effect described in the above, it becomes possible to easily replace these constituent parts and treat the waste toner without polluting the surrounding area with the toner. Therefore, the maintainability of the image forming apparatus is significantly improved. Also,
By replacing the cartridge, important components of electrophotography are replaced with new ones, so that it is possible to always maintain high-quality images.

Further, in the configuration according to the present embodiment, since the data of the cartridge itself is stored in the NVRAM mounted on the cartridge, even if the cartridge is replaced with another cartridge during use of the image forming apparatus, for example. Optimum stirring control can always be performed for the cartridge mounted in the main body of the image forming apparatus.

[0046]

As is apparent from the above description, according to the present invention, the charge amount of toner can be quickly raised at the beginning of use of the apparatus and at the time of toner replenishment, and an image having a stable density can be obtained at a high level. It is possible to provide an electrophotographic image forming apparatus capable of obtaining a quality image, a process cartridge, a developing device, and an electrophotographic image forming apparatus including the process cartridge or the developing device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an electrophotographic image forming apparatus according to a first exemplary embodiment.

FIG. 2 is a schematic configuration diagram showing a developing device of the electrophotographic image forming apparatus of FIG.

3 is a block diagram of the electrophotographic image forming apparatus of FIG.

FIG. 4 is an explanatory diagram showing a density transition of the electrophotographic image forming apparatus of FIG. 1 and an operating state of a stirring mechanism.

FIG. 5 is a configuration diagram illustrating an electrophotographic image forming apparatus according to a second exemplary embodiment.

6 is a configuration diagram showing a process cartridge detachably mountable to the electrophotographic image forming apparatus of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 developing device 2 developing chamber 3 hopper (developer accommodating portion) 6 toner 7a first stirring rod (stirring mechanism) 7b second stirring rod (stirring mechanism) 8 antenna 9 NVRAM (nonvolatile storage means) 10 counting means 11 developer Remaining amount detection device 20 Photosensitive drum (electrophotographic photosensitive member) 21 Charging means 29 Cleaning means

Claims (22)

[Claims] 1. A process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, an electrophotographic photosensitive member, a process unit including at least a developing unit that acts on the electrophotographic photosensitive member, and a developer containing unit containing a developer. Section, means for detecting the remaining amount of the developer in the developer accommodating section, an agitation mechanism for agitating the developer in the developer accommodating section, and non-volatile storage means capable of reading / writing information. Having the electrophotographic image forming apparatus main body, has a counting means for accumulating the number of printed sheets, the nonvolatile storage means,
A process cartridge, wherein the total number of printed sheets of the electrophotographic image forming apparatus and the presence / absence of a developer remaining amount detection signal are stored, and the operating condition of the stirring mechanism is changed according to the information of the nonvolatile storage means. 2. The process cartridge according to claim 1, wherein the operation of the stirring mechanism is stopped for a certain period from the initial use of the electrophotographic image forming apparatus. 3. The process cartridge according to claim 1, wherein the operating speed of the stirring mechanism is set higher than usual while the remaining amount detection signal is being output. 4. The process cartridge according to claim 1, wherein the operating speed of the stirring mechanism is set to be higher than usual during a certain period after the remaining amount detection signal is turned from ON to OFF. 5. The process cartridge integrally includes a developing unit as the process unit, a charging unit or a cleaning unit as the process unit, and the electrophotographic photosensitive member, and the cartridge is image-formed. The process cartridge according to any one of claims 1 to 4, wherein the process cartridge is removable from the apparatus main body. 6. The process cartridge comprises a developing means, a charging means and a cleaning means as the process means, and the electrophotographic photosensitive member which are integrally formed into a cartridge, and the cartridge is attached to and detached from the main body of the image forming apparatus. The process cartridge according to any one of claims 1 to 4, which is possible. 7. The process cartridge is a cartridge in which a developing means as the process means and the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the main body of the image forming apparatus. The process cartridge according to any one of claims 1 to 4. 8. An electrophotographic image forming apparatus in which a process cartridge is detachably mountable and which forms an image on a recording medium, comprising: (a) an electrophotographic photosensitive member and at least a developing unit that acts on the electrophotographic photosensitive member. Process means,
A developer accommodating portion for accommodating the developer, a means for detecting the remaining amount of the developer in the developer accommodating portion, a stirring mechanism for stirring the developer in the developer accommodating portion, and an information reading / writing The main body of the electrophotographic image forming apparatus has a counting means for accumulating the number of printed sheets, and the nonvolatile memory means has the total number of printed sheets and the presence / absence of a developer remaining amount detection signal. And a mounting means for removably mounting the process cartridge that changes the operating condition of the stirring mechanism according to the information of the non-volatile storage means in the main body of the apparatus, and (b) a transport means for transporting the recording medium. An electrophotographic image forming apparatus comprising: 9. The electrophotographic image forming apparatus according to claim 8, wherein the operation of the stirring mechanism is stopped for a certain period from the beginning of use. 10. The electrophotographic image forming apparatus according to claim 8, wherein the operating speed of the stirring mechanism is set higher than usual while the remaining amount detection signal is being output. 11. The electrophotographic image forming apparatus according to claim 8, wherein the operating speed of the stirring mechanism is set to be higher than a normal speed for a certain period after the remaining amount detection signal is turned from ON to OFF. apparatus. 12. The process cartridge comprises a developing unit as the process unit, a charging unit or a cleaning unit as the process unit, and the electrophotographic photosensitive member, which are integrated into a cartridge, and the cartridge is an image forming apparatus. The electrophotographic image forming apparatus according to any one of claims 8 to 11, which is removable from the main body. 13. The process cartridge comprises a developing means, a charging means and a cleaning means as the process means, and the electrophotographic photosensitive member which are integrally formed into a cartridge, and the cartridge is attached to and detached from the main body of the image forming apparatus. The electrophotographic image forming apparatus according to any one of claims 8 to 11, which is possible. 14. The process cartridge is a cartridge in which a developing unit as the process unit and the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the main body of the image forming apparatus. An electrophotographic image forming apparatus according to any one of claims 8 to 11. 15. A developing device having a developing means having a developer accommodating portion and detachable from the main body of the electrophotographic image forming apparatus, and means for detecting the remaining amount of the developer in the developer accommodating portion, The electrophotographic image forming apparatus main body has a stirring mechanism for stirring the developer in the developer accommodating portion and a non-volatile storage means capable of reading / writing information, and the electrophotographic image forming apparatus main body has a counting means for accumulating the number of printed sheets. The non-volatile storage means stores the total number of printed sheets of the electrophotographic image forming apparatus and the presence / absence of the developer remaining amount detection signal, and the operating condition of the stirring mechanism is changed by the information of the non-volatile storage means. A developing device characterized by the above. 16. The developing apparatus according to claim 15, wherein the operation of the stirring mechanism is stopped for a certain period from the initial use of the electrophotographic image forming apparatus. 17. The developing device according to claim 15, wherein the operating speed of the stirring mechanism is set higher than usual while the remaining amount detection signal is being output. 18. The developing device according to claim 15, wherein the operating speed of the stirring mechanism is set to be higher than usual for a certain period after the remaining amount detection signal is turned off. 19. An electrophotographic image forming apparatus equipped with a developing device of a type that replenishes developer in a timely manner, and counting means for accumulating the number of printed sheets, and detecting the remaining amount of the developer in a developer accommodating portion of the developing device. Means, an agitation mechanism for agitating the developer in the developer accommodating portion, and a non-volatile storage unit capable of reading / writing information, and the non-volatile storage unit is provided in the electrophotographic image forming apparatus. An electrophotographic image forming apparatus characterized in that the total number of printed sheets and the presence / absence of a developer remaining amount detection signal are stored, and the operating condition of the stirring mechanism is changed according to the information of the nonvolatile storage means. 20. The electrophotographic image forming apparatus according to claim 19, wherein the operation of the stirring mechanism is stopped for a certain period from the beginning of use. 21. The electrophotographic image forming apparatus according to claim 19, wherein an operating speed of the stirring mechanism is set to be higher than a normal speed while the remaining amount detection signal is being output. 22. The electrophotographic image forming method according to claim 19, wherein the operation speed of the stirring mechanism is set to be higher than a normal speed for a certain period after the remaining amount detection signal is turned from ON to OFF. apparatus.