JP2003162139A - Developer sequential remaining quantity detection means and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent erroneous detection and accurately detect the quantity of remaining toner by removing toner sticking to an electrode, in a sequential remaining quantity detection means that detects the quantity of toner in a developing device by an electrostatic capacity change. <P>SOLUTION: The electrode is disposed inside the radius of the rotation of T stir in the developing device. A vibrating member is disposed in contact with or near to the electrode. <P>COPYRIGHT: (C)2003,JPO

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 such as a laser beam printer or a copying machine, and a process cartridge mounted on the image forming apparatus, and more particularly, to a toner amount in the process cartridge. The present invention relates to means for detecting and storage means mounted on the process cartridge.

Here, a process cartridge is a cartridge in which at least one of a charging means, a developing means, and a cleaning means and an electrophotographic photosensitive member are integrally formed into a cartridge.
This cartridge is made detachable from the main body of the electrophotographic image forming apparatus, or at least the developing means and the electrophotographic photosensitive member are integrally formed into a cartridge,
This cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus.

[0003]

2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus such as an electrophotographic copying machine or a laser beam printer irradiates an electrophotographic photosensitive member with light corresponding to image information to form a latent image. An image is formed on the recording medium by supplying a developer to the recording medium to visualize the image and then transferring the image from the photoconductor to the recording medium. A developer container is connected to the developing means, and the developer is consumed by forming an image.

In such an image forming apparatus, as an electrophotographic photosensitive member and a process means acting on the electrophotographic photosensitive member for the purpose of simplifying the replacement and maintenance of the consumable items such as the electrophotographic photosensitive member and the developer. There is a process cartridge system in which the developing means, the charging means, the cleaning means, the developer storage container, the waste developer container, and the like are integrated as a process cartridge and can be attached to and detached from the main body of the image forming apparatus. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without resorting to a serviceman, so that the operability can be markedly improved. Therefore, this process cartridge system is widely used in electrophotographic image forming apparatuses.

Further, for example, in a color image forming apparatus having developing means for a plurality of colors, the developing means for each color and the developer accommodating container are made into a cartridge when the consumption of each developing means is different. In some cases, the image forming apparatus can be detachably attached to the image forming apparatus and can be individually replaced.

In such a cartridge type image forming apparatus, the user can form an image again by, for example, replacing the cartridge when the developer is used up. Therefore, such an image forming apparatus may be provided with a means for detecting when the developer is consumed and notifying the user, that is, a developer amount detecting device.
The developer amount detecting device is provided with a developer remaining amount detecting means capable of detecting a developer remaining amount level in order to be able to know at any time how much developer remains that can be used for image formation in the cartridge. It is provided in the cartridge or the main body of the image forming apparatus.

[0007] In particular, not only the user is informed that the developer is exhausted, but also the amount of the developer is sequentially detected and notified, thereby further improving the convenience for the user. In such an image forming apparatus, it is necessary to calculate how much% of the developer remains when not in use and to notify the user one by one, or that the amount of developer has decreased to such an extent that a predetermined quality image cannot be formed. In some cases, a "no developer" indication is displayed to warn the user that the developer is running low before an image defect occurs.

As a means for detecting the amount of the developer, a sheet metal serving as an electrode is provided at a location facing the developer carrying body or at a plurality of other locations, and between the sheet metal and the developer carrying body, and between them. Some of them utilize that the electrostatic capacitance between the metal plates changes depending on the amount of the developer such as insulating toner.

That is, if the space between the sheet metal and the developer bearing member or the space between the sheet metal and the sheet metal is filled with the developer, the electrostatic capacitance between them becomes large, and as the developer decreases, both of them are filled. The ratio of air occupying the space between them increases, and the capacitance decreases. Therefore, if the electrostatic capacity between the sheet metal and the developer carrier or the relationship between the electrostatic capacity between the sheet metals and the developer amount is obtained in advance, the developer amount is detected by measuring the electrostatic capacitance. be able to.

[0010]

However, in the case of the developer amount detecting means as described above, when the developer is fed toward the electrode sheet metal by stirring, the developer easily adheres to or accumulates on the sheet metal. , There is an error in the measured capacitance, and as a result, the value of the developer remaining amount detected by the developer remaining amount detecting means does not match the amount of developer actually remaining in the developing device. May occur.

For example, when the developer adheres to or accumulates on the electrode sheet metal, a situation occurs in which the developer remains in the periphery of the electrode sheet metal but the developer is not supplied to the developer carrier, and as a result, In some cases, the amount of the developer is reduced, the entire image cannot be visualized, and a state in which an image defect occurs (hereinafter referred to as a blank area) occurs before the warning is issued.

Further, since the developer adheres to or accumulates on the electrode sheet metal, the amount of the developer remaining at the time of white void becomes large and the developer is wasted.

In particular, in a high temperature and high humidity environment, water is adsorbed on the surface of the sheet metal which is the electrode, and the developer itself also adsorbs the water. Larger amount or "no developer"
A problem that a blank image occurs before the warning is issued easily occurs.

Therefore, the main object of the present invention is to remove the developer adhering to the developer remaining amount detecting means in the developing device,
It is to detect the remaining amount of the developer more accurately.

[0015]

In order to achieve the above object, the electrostatic latent image formed on the electrophotographic photosensitive member used in the main body of the electrophotographic image forming apparatus as the first means according to the present invention. In a developing device for developing an image, a developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member, a developer stirring means for stirring the developer, and a rotation of the developer stirring means. Has a plurality of electrodes for detecting the remaining amount of the developer including at least one electrode arranged in the moving area of the developer, and at least one of the electrodes arranged in the moving area of the developer has an electrode surface. A developing device comprising means for removing the adhered developer.

With the above arrangement, the developer attached or accumulated on the developer remaining amount detecting means in the developing device can be removed, more accurate developer remaining amount can be detected, and the development at the time of white spot A developing device with a small amount of developer and no waste of developer is achieved.

Further, as a second means according to the present invention, in the developing device according to the first aspect, the means for removing the developer is a developer stirring means having a turning radius for contacting the electrodes. And developing device.

With the above-mentioned structure, the developer adhered to or accumulated on the developer remaining amount detecting means in the developing device can be removed, the more accurate developer remaining amount can be detected, and the development at the time of white spot A developing device with a small amount of developer and no waste of developer is achieved.

As a third means according to the present invention, in the developing device according to the first aspect, the means for removing the developer is a vibrating member arranged in contact with or close to the electrode. And developing device.

With the above structure, the developer attached or accumulated on the developer remaining amount detecting means in the developing device can be removed, the more accurate developer remaining amount can be detected, and the development at the time of white spot A developing device with a small amount of developer and no waste of developer is achieved.

As a fourth means according to the present invention, a process cartridge attachable to and detachable from an electrophotographic image forming apparatus includes at least the developing device according to claim 1.

With the above construction, the developer attached or accumulated on the developer remaining amount detecting means in the developing device can be removed, more accurate developer remaining amount can be detected, and the development at the time of white spot A process cartridge having a small amount of developer and no waste of developer is achieved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) An image forming apparatus of this embodiment is a laser beam printer which receives image information from a host computer and outputs an image.
This is an image forming apparatus in which consumable items such as a photosensitive drum and toner are detachable from the main body as a process cartridge and can be replaced.

The configuration of this embodiment will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the process cartridge C
Is the photoconductor 1. And charging means for uniformly charging the photoconductor. And the photoconductor 1. 1. A developing roller as a developing unit that is arranged so as to oppose to 2. Developing device including 4. And cleaning means 8. And cleaning means 8. To photoreceptor 1.
Waste toner container which is a cleaner for containing the residual toner removed from the container 9. And are configured integrally.

Further, as shown in FIG. 2, a laser printer 14 which is an image forming apparatus. The process cartridge C
Above the laser beam corresponding to the image information. Laser scanner for illuminating However, the photoconductor 1. Transfer means facing to Is provided. In the above configuration, the photosensitive member 1 is the charging unit 7. Are evenly charged by the laser scanner 11. Laser light emitted from 10. Scanning exposure is carried out, and an electrostatic latent image of desired image information is formed. The electrostatic latent image is transferred to the toner container 4. The toner T inside is attached and visualized as a toner image. In this embodiment, the insulating magnetic one-component toner is used. Photoconductor 1. The above image is the transfer means 12. Is transferred to recording paper. The recording paper is a fixing unit 13. The image is fixed on the recording paper through the sheet and discharged to the outside of the main body.

Toner container 4. Inside the stirring means 3. Therefore, the stirring means 3. The toner T. If the developing roller 2. Is supplied to. In addition, the toner container 4. Figure 1. Electrode sheet metal 100 and 101. Are arranged over the entire region in the developing device 4 in the longitudinal direction.

Electrode sheet metal 100. And 101. The sheet metal as described above may basically be any material capable of passing an electric current, but in the present embodiment, rust resistant SUS is used as the material. For example, as shown in FIG. 1, an AC bias of about 2 KHz, which is a normal developing bias, and -400V.
A DC bias of a certain degree is applied to the developing roller 2 and the electrode sheet metal 10.
0. Is applied to the sheet metal. Then, the developing roller 2. And electrode sheet metal 101. , And electrode sheet metal 100. And 101. An alternating current flows between the two, and the current measuring device 6. The combined current value of the two is measured by the, and the capacitance is measured from this current value. This electrode sheet metal 100. And 101.
To the developing device 4. Inside the developing device 4. Inner toner T. Electrode sheet metal 100. And 101. Between the electrode sheet metal 101. And developing roller 2. 3. By observing the electrostatic capacity between the developing device and the developing device 4. Inner toner T. You can know the quantity. Storage means 20. Is a cleaner container 9. It is installed on the side of the cartridge C. Cleaner container 9. Image forming apparatus 14. Since it is the direction to insert inside, the storage device 2
0. And image forming apparatus 14. This is because consideration was given to facilitate alignment with the communication means on the side.

The memory control configuration in this embodiment will be described with reference to FIG.

In the case of the present embodiment, the cartridge C is provided on the upper side surface of the waste toner container 9 and has a memory 20 and a cartridge side controller 21 for controlling reading and writing of information from and to the memory.
have. When the cartridge is attached to the image forming apparatus, the memory 20 and the main body control unit 22 on the image forming apparatus side.
Are arranged to face each other.

As the memory used in the present invention, an ordinary electronic semiconductor memory can be used without particular limitation. Especially memory and read / write IC
In the case of a non-contact memory that performs data communication between the cartridges by electromagnetic waves, the cartridge side controller 21 and the main body controller 22
Since there may be no contact between them, there is no possibility of contact failure due to the mounting state of the cartridge, and highly reliable control can be performed.

These two control units constitute a control means for reading and writing information in the memory. Regarding the capacity of the memory 20, it is assumed that the memory 20 has a capacity sufficient to store a plurality of pieces of information such as a cartridge usage amount and a cartridge characteristic value. In the memory 20, the used amount of the cartridge is written and stored as needed.

FIG. 4 shows a circuit configuration for detecting the amount of toner in the process cartridge. As for the toner amount, when a predetermined AC bias is output from the developing bias circuit 104 as the developing bias applying unit, the applied bias is applied to the reference capacitor 105, the developing roller 106, and the electrode 107, respectively. As a result, a voltage V1 is generated across the reference capacitor 105,
A current corresponding to the capacitance C4 is generated between the electrodes 107 and 108. This current is converted into a voltage V2 by an arithmetic expression. In the present embodiment, the electrodes 107 and 108 correspond to the electrode sheet metal 100 and the electrode sheet metal 101.

The detection circuit 109 generates a voltage V3 from the voltage difference between the voltage V1 generated across the reference capacitor 105 and the voltage V2 between the electrode pairs, and outputs the voltage V3 to the AD converter 110. The AD converter 110 outputs the result of digital conversion of the analog voltage V3 to the main body controller 22. The main body control unit 22 recognizes the amount of toner in the process cartridge from the voltage value converted into this digital value.

As described above, in this embodiment, the image forming apparatus main body converts the electrostatic capacitance value detected by the toner remaining amount detecting means into a voltage and outputs the voltage value as shown in FIG. The relationship between the capacitance and the voltage varies depending on the circuit of the image forming apparatus, and the relationship between the capacitance and the voltage may be the same decreasing function or increasing function.

In the process cartridge for detecting the remaining amount of toner by the means as described above, in the first embodiment, as shown in FIG. 11, the stirring means 3 in the toner container 4 is provided with a Mylar sheet having a thickness of 100 μm. A member attached to the shaft was used, and at least one electrode was arranged inside the turning radius.

As a comparative example, in the conventional structure shown in FIG. 13, that is, in the structure in which all the electrodes are arranged outside the rotation radius of the stirring means, 200 (g) of toner is filled and the N / N environment ( The durability test was conducted until white spots occurred at 25 °, 30%), and the transition of the detected value from the toner remaining amount detecting means is shown in FIG. The measured detection value deviates from the ideal value and shows a low output value as the remaining toner amount decreases. That is, due to the toner adhering to the electrodes, the measured capacitance increases and the output voltage decreases. In this state, the main body control unit recognizes and displays a toner remaining amount different from the toner amount actually remaining in the developing device, and therefore, for example, a blank image occurs before the warning. Problems such as being lost will occur.

Table 1 also shows a high temperature and high humidity environment (32 °, 80 °
%) Indicates the residual toner amount at the time of white void. With the conventional configuration, 30 (g) of toner remains in the developing device when white spots occur.

[0039]

[Table 1]

On the other hand, the structure used in this embodiment, in which the electrodes are arranged inside the radius of rotation of the stirring means (FIG. 11)
Then, 200 (g) of toner is charged and the N / N environment (25
As a result of performing a durability test until white spots occur at 30 °, 30 °), as shown in FIG. 7, when the toner remaining amount becomes low, the agitating means adheres in a form of striking the electrode. Due to the effect of dropping the toner, the actually detected detection voltage showed a transition almost equal to the ideal value.

Table 1 also shows a high temperature and high humidity environment (32 °, 80 °
%) Indicates the residual toner amount at the time of white void. According to the configuration of the present embodiment, it is possible to reduce the amount of toner remaining at the time of white spots as compared with the conventional configuration, and it is possible to eliminate waste of toner.

When the configuration of this embodiment is used, in the first half of durability, that is, when the toner is sufficiently left, the stirring sheet is bent by the weight of the toner and does not come into contact with the electrode sheet metal. Alternatively, the noise does not occur, and in the latter half of durability, that is, just before the white spots, the stirring sheet comes into contact with the electrode plate metal and scrapes off the adhered or accumulated toner, so that the accurate remaining toner amount can be detected. Have

In the present embodiment, the electrode sheet metal method is used as the toner residual amount level detecting means, but the present invention is not limited to this type of toner residual amount detecting means, and if the toner residual amount can be detected, The method does not matter.

(Embodiment 2) Used in the second embodiment,
Regarding the image forming apparatus, the process cartridge detachable from the image forming apparatus, and the method for detecting the remaining amount of toner successively,
Since it is similar to the first embodiment, it is omitted here.

In this embodiment, as shown in FIG. 12, the vibrating member 200 and the vibrating member 2 are placed at the positions in contact with the electrode sheet metal.
A power source 201 for driving the 00 is provided. When the amount of remaining toner decreases, the vibrating member vibrates for several seconds when the drum stops after image formation, and shakes off the toner adhering to the electrode sheet metal.

Here, the circuit configuration of this embodiment will be described with reference to FIG.

As described with reference to FIG. 4 in the first embodiment, the output voltage from the electrode sheet metal in the developing device is used to detect the remaining amount detection unit 26.
Is detected, and the main body control unit 23 performs arithmetic processing based on the detected value to determine what percentage of the remaining toner amount is. The detection unit 300 determines whether the photoconductor is driving or stopped. Information from the main body control unit 23 and information from the detection unit 300 are input to the vibration member control unit 202,
When the remaining amount of toner in the developing device is 25% or less and the photoconductor is stopped, the power supply 201 is operated and the vibration member 200 is driven.

Next, the operation of the vibrating member of this embodiment will be described with reference to the flowchart of FIG. S301: Power switch ON S302: Printing is started according to the input signal. S303: The remaining toner amount is detected by measuring the electrostatic capacity. S304: The main body control unit 23 performs a calculation process based on the detection voltage V3 from the remaining amount detection detection unit 26, and confirms whether the remaining toner amount is 25% or more. 2 toner remaining
If it is determined to be 5% or less (Yes), the process proceeds to S305. S305: The photoconductor detection unit 300 confirms whether or not the photoconductor is stopped. S306: The vibration member control unit 202 turns on the power supply 201 for only a few seconds. S307: The vibration member 200 is driven. S308: The print ready state is set and the next print signal is prepared.

The same control as above is repeated until the remaining toner amount reaches 0%.

Thus, the remaining amount of toner in the developing device is 2
When it is 5% or less, control is performed such that the vibrating member vibrates for a few seconds when the photoconductor stops after each printing.

By performing the operation according to the above-mentioned flow chart, it is possible to suppress the adhesion and deposition of the toner on the electrode sheet metal as much as possible.

With the configuration used in this embodiment, 200 (g)
Fig. 1 shows the results of a durability test in which the toner of No. 1 was filled and white spots occurred in an N / N environment (25 °, 30%).
It was shown at 0. When the remaining toner amount of 25% is detected, the vibrating member is activated by the above control method, and the toner adhering to the electrodes is shaken off, whereby the actually measured detected voltage shows a transition substantially equal to the ideal value.

Table 1 also shows a high temperature and high humidity environment (32 °, 80 °
%) Indicates the residual toner amount at the time of white void. According to the configuration of the present embodiment, it is possible to reduce the amount of toner remaining at the time of white spots as compared with the conventional configuration, and it is possible to eliminate waste of toner.

In the present embodiment, the electrode sheet metal method is used as the toner remaining amount level detecting means, but the present invention is not limited to this type of toner remaining amount level detecting means, and it is possible to detect the toner remaining amount level. The method does not matter.

[0055]

As described above, according to the present invention,
By a simple method, it is possible to effectively remove the developer adhered to or accumulated on the developer remaining amount detecting means in the developing device.
It is possible to always grasp the accurate remaining amount of the developer. Also,
Since the amount of developer remaining at the time of white voids can be minimized, a process cartridge that does not waste developer can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view of a process cartridge according to a first exemplary embodiment of the present invention.

FIG. 2 is a sectional view of the process cartridge image forming apparatus according to the first embodiment of the present invention.

FIG. 3 is a block diagram of main body control unit information and memory information according to the first embodiment of the present invention.

FIG. 4 is a circuit configuration diagram for detecting the amount of toner in the process cartridge according to the first exemplary embodiment of the present invention.

FIG. 5 is a relationship between the remaining toner amount and the detected voltage according to the first exemplary embodiment of the present invention.

FIG. 6 is a relationship between a remaining toner amount and a detected voltage in a comparative example of the first embodiment according to the present invention.

FIG. 7 is a relationship between the remaining toner amount and the detected voltage according to the first exemplary embodiment of the present invention.

FIG. 8 is a circuit configuration diagram for driving a vibrating member according to a second embodiment of the present invention.

FIG. 9 is a flowchart of the operation of the vibrating member according to the second embodiment of the present invention.

FIG. 10 is a relationship between the remaining toner amount and the detected voltage according to the second embodiment of the present invention.

FIG. 11 is a sectional view of the developing device according to the first embodiment of the present invention.

FIG. 12 is a sectional view of a developing device according to a second embodiment of the present invention.

FIG. 13 is a diagram showing a conventional configuration.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Developing sleeve 3 T stirring 4 Developing container 5 Developing blade 6 Applied bias power source for successive residual detection 7 Charging roller 8 Cleaning blade 9 Cleaning container 10 Laser light 11 Laser unit 12 Transfer roller 13 Fixing unit 14 Laser beam printer 20 Memory 21 Memory-side Transmission Section 22 Main Body Control Section 23 Control Section 26 Main Body Remaining Amount Detection Detection Sections 100, 101 Electrode Sheet Metal 104 as Toner Remaining Amount Level Detection Unit Development Bias Power Supply 105 Reference Capacitor 106 Developers 107, 108 Electrode 109 Detection Circuit 110 AD Converter C Process Cartridge T Toner

Claims (4)

[Claims] 1. A developing device for developing an electrostatic latent image formed on an electrophotographic photosensitive member, which is used in a main body of an electrophotographic image forming apparatus, wherein the electrostatic latent image formed on the electrophotographic photosensitive member is A developing member for developing, a developer stirring means for stirring the developer,
In the moving area of the developer generated by the rotation of the developer stirring means, there is provided a plurality of electrodes for detecting the remaining amount of the developer including at least one electrode, and the electrode arranged in the moving area of the developer. At least one of the developing devices is provided with a means for removing the developer adhering to the surface of the electrode. 2. The developing device according to claim 1, wherein the means for removing the developer is a developer stirring means having a radius of gyration that contacts the electrode. 3. The developing device according to claim 1, wherein the means for removing the developer is a vibrating member arranged in contact with or close to the electrode. 4. A process cartridge attachable to and detachable from an electrophotographic image forming apparatus, comprising at least the developing device according to claim 1.