JP2000338763A - Developing device, processing cartridge, and electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive developing device, a processing cartridge, and an electrophotographic image forming device making convenient property possible to be improved in the case of using the device by a user, equipped with developer quantity detecting means of a simple structure capable of correctly and accurately detecting the developer from a state of full tank to the state of the near end right before the occurrence of printing failure. SOLUTION: The developer detecting electrode 40 is arranged to face of the developer carrier 12 oppositely. The developer remaining quantity detectable area defined by the developer carrier 12 and the developer detecting electrode 40 is, beyond 50% of the initial developer capacity in the developer container 11, and moreover, detection differential of the developer remaining quantity with regard to the change of the developer quantity in association with developer consumption of the developer remaining quantity detectable area 41 is below ±10%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an electrophotographic system in which an electrostatic latent image is formed on an image carrier by an electrophotographic method, and the electrostatic latent image is visualized by a developer contained in a developing device. The present invention relates to a photographic image forming apparatus, and more particularly, to an electrophotographic image forming apparatus provided with a developer amount detecting unit capable of sequentially detecting the remaining amount of developer stored in a developer storing unit, and further relates to a process cartridge and a developing device. Things.

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.

A process cartridge is a cartridge in which at least one of a charging unit, a developing unit, and a cleaning unit and an electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is detachably mountable to an electrophotographic image forming apparatus main body. Or a cartridge in which at least the developing means and the electrophotographic photosensitive member are integrally formed, and this cartridge is detachable from the main body of the electrophotographic image forming apparatus.

[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 electrophotographic image forming apparatus. A process cartridge system detachable from the main body is employed. According to this process cartridge system, maintenance of the apparatus can be performed by the user himself without relying on a service person, so that operability can be remarkably improved. Therefore, this process cartridge system
It is widely used in electrophotographic image forming apparatuses.

In such an electrophotographic image forming apparatus of the process cartridge type, since the user has to replace the cartridge by himself / herself, a means for notifying the user when the developer is consumed, that is, a developer amount detecting device is used. Required.

More specifically, FIG. 20 shows an example of an image forming apparatus A in which a conventional process cartridge B is mounted. A developing unit 10 that constitutes a developing unit using the process cartridge B includes a developing unit 13 that supplies a developer T to a latent image formed on the photosensitive drum 1 as an image carrier to visualize the latent image.
And a hopper section 14 for storing and storing the developer T
And a hopper section 14.
The developer T inside is transported from the hopper section 14 to the developing section 13 by the gravity and stirring device 15A, 15B or other developer transporting means.

In the developing section 13, a developing roller 12, which is a cylindrical developer carrier for transporting the developer T to a developing position facing the photosensitive drum 1, is disposed close to the photosensitive drum 1. , The developer T on the surface of the developing roller 12
Is adhered and held, and the developer T
To the developing position facing the photosensitive drum 1.

While the developer T is being conveyed, the amount and height of the developer T are restricted by developer regulating means 17 such as a doctor blade, and the developer T is uniformly applied onto the developing roller 12. In the process of being transported to the developing roller 12, the developing roller 12, the developer regulating means 17, or the developer itself is rubbed and charged.

The developer T conveyed by the developing roller 12 to the opposing portion of the photosensitive drum 1, ie, the developing position, is supplied to a developing bias power supply 12A as a bias applying means between the photosensitive drum 1 and the developing roller 12. The photosensitive drum 1 is transferred to the photosensitive drum 1 by an appropriate developing bias voltage applied thereto, and the electrostatic latent image on the photosensitive drum 1 is developed into a toner image.

The developer T that has not been subjected to the development is conveyed while remaining on the developing roller 12, and is again stored in the developing section.

On the other hand, the recording medium P set in the paper feed cassette 20 in synchronization with the formation of the toner image is transferred to a transfer position by a conveying means 22 including a pickup roller 21, a pair of conveying rollers, and a registration roller (not shown). And convey. A transfer roller 4 as a transfer unit is disposed at the transfer position, and transfers a toner image on the photosensitive drum 1 to the recording medium P by applying a voltage.

The recording medium P to which the toner image has been transferred is conveyed to the fixing means 5 by the conveyance guide 23. Fixing means 5
Is provided with a fixing roller 5a including a driving roller 5c and a heater 5b, and applies heat and pressure to the recording medium P passing therethrough to fix the transferred toner image on the recording medium P. Thereafter, the recording medium P is discharged outside the apparatus.

After the transfer of the toner image onto the recording medium P by the transfer roller 4, the photosensitive drum 1
After the developer remaining on the photosensitive drum 1 is removed by the above process, the photosensitive drum 1 is subjected to the next image forming process. The cleaning means 6 scrapes off the residual developer on the photosensitive drum 1 by an elastic cleaning blade 7 provided in contact with the photosensitive drum 1 and collects it in a waste developer reservoir 8.

As described above, in the developing device 10,
Each time the developing operation is repeatedly performed, the developer T is consumed, and if the developer is insufficient, defects such as a decrease in image density and a missing image occur. For this reason, it is necessary to monitor the presence or absence of the developer T in the developing unit 13 at any time so that the developer shortage does not occur.

Therefore, the conventional developing device 10 has a developer amount detecting device as a means for detecting the remaining amount of the developer. The developing amount detecting device is used to detect the remaining amount of the developer T. And a rod-shaped developer remaining amount detecting antenna electrode 18 disposed in the developing unit 13 in a horizontal direction.

The developer amount detecting device further has a developer amount measuring circuit 50, and this developer amount measuring circuit 50
A capacitance detection circuit 52 is provided as a means for measuring the capacitance between the antenna electrode 18 and the developing roller 12. The antenna electrode 18 is connected to the capacitance detection circuit 52. Thus, the electrostatic capacitance between the antenna electrode 18 and the developing roller 12 is measured by detecting the developing bias voltage supplied to the developing roller 12 by the developing bias power supply 54 by the antenna electrode 18.

The developer amount measuring circuit 50 includes a reference capacitance 5 as a means for setting a capacitance as a reference for comparison.
3 and a capacitance detection circuit 51 as a means for measuring the reference capacitance 53. The reference capacitance 53 is connected to the developing bias power supply 12A. Is detected, thereby obtaining a capacitance that is a reference for measuring the unknown capacitance.

The developer amount detecting device includes a capacitance detecting circuit 5
1 and the output of the capacitance detection circuit 52 of the reference capacitance are compared by a comparison circuit 55 as comparison means to detect the difference, and when the difference is smaller than a predetermined value, the development is performed. The developer warning circuit 57 determines that the developer has run out, and notifies the user that the developer T is running low.

Since this method has a simple structure and is relatively inexpensive, it is often used in small image forming apparatuses having a process cartridge mounted thereon.

[0020]

However, as described above, in the conventional image forming apparatus, the developer remaining amount detecting antenna electrode 18 is disposed in the developing unit 13.
According to this detection method, it is possible to accurately detect (near-end detection) just before the developer runs out. However, when replenishment of the developer means replacement of the process cartridge B as in the case of the process cartridge B, the developer signal is detected by a detection signal. The user who was suddenly informed that the number of prints was small had to give up printing a large amount unless a spare process cartridge was prepared.

Further, in the image forming apparatus using the above-described method for detecting the remaining amount of the developer, the detection level of the remaining amount of the developer is from 1 to 3 levels, and the conventional circuit has a low detection accuracy. Electrode arrangements with emphasis on detection were forced. Therefore, although the accuracy immediately before the developer is exhausted is high, it is impossible to accurately know the remaining amount of the developer before that.

Furthermore, in recent years, a technology has been developed which can load a large amount of transfer material as a recording medium in an image forming apparatus and print at a high speed, and these devices are used by being shared by a plurality of users via a computer network. Below, the remaining amount of the developer in the process cartridge B is
From now on, it is required to determine whether or not printing is possible for the number of prints to be printed in large quantities.

In other words, the conventional developer remaining amount detection is a fuel warning in a car. Although the minimum number of printed sheets after the warning can be estimated, in the state where the warning is not issued, how much the current developer remaining amount is. It was not in a state where the user could determine whether printing was possible. Therefore, it has been strongly desired to display the remaining amount of the developer with a gas gauge due to the change in the use environment.

That is, the conventional developer amount detecting device detects the presence or absence of the developer in the developing container.
It was only possible to detect that the amount of developer was low immediately before using up the developer in the developing container, and it was not possible to detect how much developer remained in the developing container.

On the other hand, if the remaining amount of the developer in the developing container can be sequentially detected, the user can know the use condition of the developer in the developing container, and a new process cartridge can be installed in time for replacement. It can be prepared and is very convenient for users.

In order to solve such a problem, there is also a method of counting the number of printed sheets or integrating the time of a light emission signal to a laser or the like for forming an electrostatic latent image to sequentially grasp the remaining amount of the developer. Although proposed, the conventional method has a large error due to fluctuations in the amount of toner used due to fluctuations in the use environment and fluctuations in the printing rate of the printed image.

Accordingly, an object of the present invention is to provide a developer amount detecting means having a simple structure capable of accurately and accurately detecting a state from a full state of a developer to a near-end state immediately before a printing failure. It is an object of the present invention to provide an inexpensive developing device, a process cartridge, and an electrophotographic image forming apparatus which can improve the convenience in using the apparatus.

[0028]

The above object is achieved by a developing device, a process cartridge and an electrophotographic image forming apparatus according to the present invention. In summary, according to a first aspect of the present invention, there is provided an electrophotographic image forming apparatus, comprising: a developing device for developing an electrostatic latent image formed on an electrophotographic photosensitive member; A developing container containing a developer for developing the electrostatic latent image formed on the photoreceptor and transporting the developer to the electrophotographic photoreceptor; A developer detection electrode disposed opposite to the developer carrier for detecting the amount in the electrophotographic image forming apparatus main body; and the developer carrier and the developer detection electrode. Is greater than or equal to 50% of the initial developer volume in the developer container, and the amount of developer associated with the consumption of the developer in the developer remaining amount detectable region is defined as The detection error of the remaining amount of developer is less than ± 10% Developing apparatus is provided, characterized in that.

According to a second aspect of the present invention, there is provided a process cartridge detachably mountable to an electrophotographic image forming apparatus main body, wherein (a) an electrophotographic photosensitive member and (b) a photosensitive member formed on the electrophotographic photosensitive member. A developing device having a developing container for storing the developer for transporting the developer to the electrophotographic photoreceptor for developing the electro-latent image; A developer detection electrode disposed opposite to the developer carrier for detecting the amount in the electrophotographic image forming apparatus main body; and the developer carrier and the developer detection electrode. Is greater than or equal to 50% of the initial developer volume in the developer container, and the amount of developer associated with the consumption of the developer in the developer remaining amount detectable region is defined as ± 10% of detection error of remaining amount of developer against change The process cartridge, which is a lower are provided.

According to a third aspect of the present invention, in an electrophotographic image forming apparatus for forming an image on a recording medium,
(A) an electrophotographic photosensitive member, (b) an electrostatic latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member, and (c)
In order to develop the electrostatic latent image formed on the electrophotographic photosensitive member, the developing device includes a developing container having a developer carrier for storing a developer and transporting the developer to the electrophotographic photosensitive member. A developing device; (d) a developer detection electrode disposed to face the developer carrier for detecting the remaining amount of the developer in the electrophotographic image forming apparatus main body; and (e) the developer Bias voltage applying means for applying an alternating bias voltage to the carrier; and (f) developer amount detecting means for measuring an electrostatic capacity between the developer carrier and the developer detecting electrode to grasp the amount of developer. A developer remaining amount detectable region defined by the developer carrier and the developer detection electrode is 50% or more of an initial developer volume in the developing container; and The amount of developer associated with the consumption of developer in the developer remaining amount detectable region; Detection error of the remaining developer is an electrophotographic image forming apparatus is provided, characterized in that at most 10% ± respect of.

According to the fourth aspect of the present invention, there is provided an electrophotographic image forming apparatus for detachably attaching a process cartridge and forming an image on a recording medium, comprising: (a) an electrophotographic photosensitive member; A developing device having a developer container having a developer carrier for storing a developer and transporting the developer to the electrophotographic photoconductor in order to develop an electrostatic latent image formed on the photoconductor; and Mounting means for removably mounting a process cartridge having:
(B) a developer detection electrode disposed opposite to the developer carrier for detecting the remaining amount of the developer in the electrophotographic image forming apparatus main body; and (c) static electricity on the electrophotographic photosensitive member. Electrostatic latent image forming means for forming an electrostatic latent image; (d) bias voltage applying means for applying an alternating bias voltage to the developer carrier; and (e) the developer carrier and the developer detection. And a developer amount detecting means for measuring a capacitance between the developing electrodes and grasping a developing agent amount, wherein a developer remaining amount defined by the developer carrier and the developer detecting electrode is provided. The available area is 50% or more of the initial developer volume in the developing container, and the remaining amount of the developer is detected in response to a change in the amount of the developer due to the consumption of the developer in the remaining amount of the developer. An electrophotographic image forming apparatus having an error of ± 10% or less is provided. That.

In one embodiment of the present invention,
At least two or more developer detection electrodes are provided, and a developer remaining amount detectable area defined by the developer carrier and each of the developer detection electrodes facing the developer carrier is provided. Is greater than or equal to 50% of the initial developer volume in the developer container, and the remaining amount of the developer is detected with respect to a change in the amount of the developer accompanying the consumption of the developer in the developer remaining amount detectable region. The error is ± 10% or less.

According to another embodiment, a conductive member can be provided near the developer carrier so as to face the developer detecting electrode. The conductive member may include a metal support member as a regulating unit that regulates the developer layer on the developer carrier.

According to another embodiment, the developer detecting electrode is provided with a capacitance between the developer detecting electrode and the developer carrier generated when a voltage is applied to the developer carrier. Is transmitted to a developer amount detecting means provided in the electrophotographic image forming apparatus main body for detecting the remaining amount of the developer. Further, the developer detecting electrode is configured such that the developer detecting electrode generated when a voltage is applied to the developer carrying member and the conductive member, and the electrostatic force between the developer carrying member and the conductive member. An electric signal corresponding to the capacity is transmitted to a developer amount detecting means provided in the electrophotographic image forming apparatus main body for detecting a remaining amount of the developer.

According to one embodiment of the present invention, the developer carrier is a developing roller.

According to still another embodiment, the voltage applied to the developer carrier or the conductive member is an alternating bias voltage, and the alternating bias voltage is obtained by superimposing a DC voltage on an AC voltage. Developing bias voltage.

According to still another embodiment, the developer detecting electrode is a metal plate-like member arranged to extend along the longitudinal direction of the developing roller.

According to still another embodiment, the developer amount detecting means includes a reference static amount substantially equal to a minimum value of a capacitance formed between the developer carrier and the developing-seat detecting electrode. A capacitance detection circuit that has a capacitance and measures the reference capacitance, and a capacitance detection circuit that measures a capacitance between the developer carrier and the electrode for detecting the developing seat. A differential circuit for comparing the capacitance measured by the circuit.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a developing device, a process cartridge and an electrophotographic image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

Embodiment 1 First, an embodiment of an electrophotographic image forming apparatus to which a process cartridge constructed according to the present invention can be mounted will be described with reference to FIGS. In this embodiment, the electrophotographic image forming apparatus is an electrophotographic laser beam printer, which forms an image on a recording medium, for example, a recording paper, an OHP sheet, a cloth, or the like by an electrophotographic image forming process. .

The laser beam printer A has a drum-shaped electrophotographic photosensitive member, that is, a photosensitive drum 1. The photosensitive drum 1 is charged by a charging roller 2 serving as a charging unit constituting an electrostatic latent image forming unit, and then is transferred from an optical unit 3 having a laser diode, a polygon mirror, a lens, a reflection mirror (not shown), and the like. By irradiating a laser beam corresponding to the image information, a latent image corresponding to the image information is formed on the photosensitive drum 1. This latent image is developed by a developing device 10 as a developing unit of the process cartridge B, and is made a visible image, that is, a toner image.

The developing device 10 has a developing container 11, and the developing container 11 has a developing section 13 having a developing roller 12 as a developer carrier and a developer hopper section 14. When the developer T stored in the developing unit 13 and the hopper unit 14 is consumed, the developing device 10 can perform a new print by exchanging a new cartridge B by the user himself / herself.

In the developing device 10, a stirring device 15 (15A, 15B) is provided in the developer hopper portion 14 for the purpose of preventing the internal developer T from sticking, circulating and transporting. . The stirring device 15 may be formed of a resin film such as PET (polyethylene terephthalate) or a rubber material such as silicone rubber or urethane rubber, or may be formed of a metal plate such as SUS or phosphor bronze. Then, it is rotated in the direction of the arrow in the figure by a driving means (not shown).

The developing roller 12 as a developer carrier
In this embodiment, a fixed magnet (magnet) is placed inside a non-magnetic sleeve such as aluminum or stainless steel.
The developer is conveyed by rotating the developing roller 12, and triboelectrically charged by an elastic developing blade 17 made of urethane rubber, silicon rubber, or the like as a developer amount regulating member. And a developer layer having a predetermined thickness is supplied to the developing area of the photosensitive drum 1. The developer supplied to this developing area is
The toner image is transferred to a latent image on the photosensitive drum 1 to form a toner image. The developing roller 12 is connected to a developing bias power supply 12aA, and is usually applied with a developing bias voltage in which a DC voltage is superimposed on an AC voltage.

In the present embodiment, the developing device 10 uses a magnetic developer containing a magnetic material as the developer T and employs a jumping development method. A non-magnetic developer which does not contain a non-magnetic developer can be used. Therefore, the developing device 10 can be a magnetic one-component developing device in which the developer itself contains a magnetic carrier as in the present embodiment, but a two-component developing device having a magnetic carrier,
Alternatively, a non-magnetic one-component developing device that does not use a magnetic carrier may be employed. Also, the developing method is not limited to the jumping developing method, and various developing methods can be used.

The developer T contained and used in the developing device 10 is produced by a pulverizing method or a polymerization method. In the developing device 10 of the present embodiment, the average particle diameter is set so that a fine image can be reproduced. A small developer was used.

On the other hand, the recording medium P set in the paper feed cassette 20 in synchronization with the formation of the toner image is transferred to a transfer position by a conveying means 22 including a pickup roller 21, a pair of conveying rollers and a registration roller (not shown). And convey. A transfer roller 4 as a transfer unit is disposed at the transfer position, and transfers a toner image on the photosensitive drum 1 to the recording medium P by applying a voltage.

The recording medium P to which the toner image has been transferred is conveyed to the fixing means 5 by the conveyance guide 23. Fixing means 5
Is provided with a fixing roller 5a including a driving roller 5c and a heater 5b, and applies heat and pressure to the recording medium P passing therethrough to fix the transferred toner image on the recording medium P. Thereafter, the recording medium P is discharged outside the apparatus.

After the transfer of the toner image onto the recording medium P by the transfer roller 4, the photosensitive drum 1
After the developer remaining on the photosensitive drum 1 is removed by the above process, the photosensitive drum 1 is subjected to the next image forming process. The cleaning means 6 scrapes off the residual developer on the photosensitive drum 1 by an elastic cleaning blade 7 provided in contact with the photosensitive drum 1 and collects it in a waste developer reservoir 8.

On the other hand, in this embodiment, the process cartridge B includes a developing frame 31 for holding the developing container 11 and the like constituting the developing device 10, a cleaning means 6 such as the photosensitive drum 1 and the cleaning blade 7, and a charging device. Roller 2
The cartridge is formed by integrally connecting the cleaning frame 32 to which is attached.

The process cartridge B is removably mounted on a cartridge mounting means 33 provided on the main body of the electrophotographic image forming apparatus by a user.

According to the present invention, the process cartridge B
Is provided with a developer amount detecting device capable of sequentially detecting the remaining amount according to consumption of the developer in the developing unit 13 and the hopper unit 14.

According to the present invention, the developer amount detecting device includes a developer remaining amount detecting antenna 40 as a developer detecting electrode.
And a capacitance detecting circuit 50 as a developer amount detecting means. It is a conductive plate-shaped member, that is, a metal plate, which is disposed to face the developer remaining amount detecting antenna 40 and the developing roller 12. As the metal plate, any metal plate such as aluminum or stainless steel having a thickness of about 0.1 to 1 mm can be used. Also, the metal plate 40
Need not be a single member, but may be formed by a plurality of divided members.

The toner developer remaining amount detecting antenna 40 is
In the present embodiment, it is mounted so as to be located outside the developing frame 11, but the present invention is not limited to this, and it is also possible to arrange it inside the developing container 11, for example. Also, depending on the case, instead of the developing device, the developing frame 31 or
It can be attached to the image forming apparatus main body. In this case, there is no need to attach an electrode to the developing device 10, and there is an advantage that the developing device can be simplified and the cost of the developing device can be reduced.

Further, in this embodiment, the developer remaining amount detecting antenna, that is, the metal plate 40 is arranged so as to extend approximately 300 mm in length equal to the length of the developing roller 12 in the longitudinal direction. In this embodiment, the diameter of the developing roller 12 was 20 mm, and the width of the metal plate 40 was 40 mm. Metal plate 40 of the present invention
Is not limited to the developing roller 12 and the metal plate 40 described above, as long as the following relationship is satisfied.

According to the present invention, as shown in FIG. 2, a hatched area connecting the upper and lower ends of the metal plate 40 and the outer periphery of the developing roller 12 is defined as a developer remaining amount detectable area 41. The remaining amount detectable area 41 is 50% of the initial developer amount.
As described above, the detection error of the remaining amount of the developer is set to ± 10% or less with respect to the change in the amount of the developer due to the consumption of the developer in the remaining amount of the developer detectable region 41.

By making 50% or more of the initial developer amount of the developing device a detectable area, 50% of the life of the cartridge can be obtained.
As described above, the remaining amount of the developer can be accurately detected.

Further, the detection error of the remaining amount of the developer is set to ± 10% or less with respect to the change in the amount of the developer due to the consumption of the developer in the developer remaining amount detectable area 41. We are improving.

Next, with reference to FIG. 3, a description will be given of the capacitance detecting circuit 50 as the developer remaining amount detecting means.

The capacitance detection circuit 50 is composed of a first capacitance detection circuit 51 and a developer remaining amount detection antenna, that is, a second capacitance detection circuit 52 connected to the metal plate 40. Have. An alternating bias power supply 1 is connected to a first capacitance detection circuit 51 via a reference capacitance (capacitor) Cref.
2A, the same bias voltage as the alternating bias voltage applied to the developing roller 12 is applied by being shunted from the alternating bias power supply 12A.

The capacitor Cref has the capacity of the developing roller 12 and the antenna for detecting the remaining amount of the developer, that is, the capacity of the metal plate 40 in the state of the amount of the toner determined to be small. The first capacitance detection circuit 51 has a rectifier circuit 51A and a voltage conversion circuit 51B, and generates a reference voltage Vref for detecting the remaining amount of the developer. This reference voltage Vr
ef is input to the differential circuit 55.

On the other hand, the developing roller 12 and the antenna for detecting the remaining amount of the developer, that is, the metal plate 40, respectively correspond to the pole plates of the capacitor, and the capacitance C0 between them is equal to the developing roller 12 and the metal plate. It varies depending on the amount of the developer existing between the developer.

The change in the capacitance is transmitted to a second capacitance detection circuit 52 connected to the metal plate 40. Second
Has a rectifier circuit 52A and a voltage conversion circuit 52B, and inputs the antenna output voltage Va to the differential circuit 55.

The differential circuit 55 compares the signal Vref measured via the capacitor Cref with the signal Va measured via the metal plate 40, and then controls the microcomputer (MPU) for sequentially controlling the laser beam printer. ) Convert to a DC voltage Vout that can be input to 56 and input.

The detection voltage Vout gradually increases as the amount of the developer in the developing device decreases, as shown in FIG. FIG. 4 shows that the decrease in the remaining amount of the developer and the decrease in the detection voltage are substantially proportional to each other. Therefore, it is possible to accurately detect the amount of the developer according to the detected voltage value.

In the microcomputer (MPU) 56, information on the remaining amount of developer is displayed on the remaining developer amount display means 100 such as a personal computer or an operation panel of an electrophotographic image forming apparatus through the general-purpose interface 101 in accordance with the value of the detection voltage Vout. , And the current toner amount can be sequentially displayed on the personal computer screen and the operation panel of the electrophotographic image forming apparatus.

For example, information detected by the above-described developer amount detecting device is displayed on a terminal screen of a user's personal computer or the like as the developer remaining amount display means 100 as shown in FIGS. 4 and 5. 4 and 5, the amount of the developer is notified to the user based on which part of the gauge 59 the needle 58 that moves according to the amount of the developer touches.

As shown in FIG. 6, a developer remaining amount display means 100 such as an LED 60 may be provided directly on the main body of the electrophotographic image forming apparatus, and the LED may be turned on and off in accordance with the amount of the developer.

As described above, according to the present invention, 50% or more of the initial developer amount of the developing device is set as the detectable region, and the developer amount accompanying the consumption of the developer in the developer remaining amount detectable region 41 is determined. The detection error of the remaining amount of developer is ± 1
By setting it to 0% or less, improvement in developer detection accuracy is achieved. The features of the present invention will be further specifically described below.

FIG. 8 shows a developing device having a developer remaining amount detectable region 40 according to the present invention, and FIG. 9 shows a developing device having a developer remaining amount detectable region 40 as a comparative example. Is shown.

In the developing device shown in FIG.
A developer remaining amount detectable area 40 defined by a metal plate 40 serving as a developer detecting electrode arranged opposite to the developing roller 12 covers the bottom developer in the developing container. In contrast, in the developing device of the comparative example shown in FIG. 9, the developer remaining amount detectable region 40 does not cover the developer contained in the A and B regions at the bottom of the developing container. The remaining amount of the developer in the areas A and B cannot be detected.

Accordingly, in the developing device of the comparative example shown in FIG.
Out is as shown by a solid line in FIG. That is, in FIG. 10, when the developer in the region A in FIG. 9 is consumed, the detection voltage Vout changes from Va1 to Va2 ′, and after the developer in the region A is consumed, the detection voltage Vout changes. Starts changing from Va2 '. At this time, the change from Va1 to Va2 ′ has a smaller slope than the detection voltage Vout (dotted line in FIG. 10) corresponding to the accurate developer amount, while the detection voltage corresponding to the accurate developer amount. Vou
At t (dotted line in FIG. 10), assuming that the detection voltage Va2 when the developer in the region A is consumed, Va1 is an error αa with respect to the detection voltage Va2 corresponding to the actual amount of the developer.
= 100 × (Va2−Va2 ′) / Va2.

Accordingly, the presence of the region A makes it impossible to measure the amount of the developer when the developer in the region A is consumed, and when the error αa is larger than 10%, the entire developer is not measured. It becomes impossible to accurately detect the amount and to transmit the amount of the developer accurately to the user.

The area B also produces an error in the detection voltage Vout by the same mechanism as the area A. In particular, when the error of the detection voltage in the region B is larger than 10%, the detection voltages VTlow and V at the time of issuing a warning of the developer running out Tout that causes an image defect such as a small amount of developer Tlow and a white spot are generated.
In some cases, the accuracy of Tout detection is reduced, and the user is inaccurate in transmitting the cartridge replacement time to the user, which may lead to a decrease in usability. That is, the error αa is ±
If it is larger than 10%, it is the same as not detecting the areas A and B in the present embodiment. In particular, the inability to detect the area B means that the toner Low and the toner End cannot be detected. Therefore, the error αa is ± 10%
In the following, even if the areas A and B exist at the bottom of the developer container, it is necessary to detect the toner in these areas to grasp the accurate amount of the developer and to detect the remaining amount of the developer.

The developer volume of the developer T described in the present invention is the stationary volume of the developer T filled in the developing unit 13 and the hopper unit 14, and is the developing device 10, ie, the process. When the cartridge B is stopped in the same state as when the remaining amount of the developer is detected, the volume of the developer T is settled by its own weight, and is not the volume of the movable portion or the volumes of the developing portion 13 and the hopper portion 14.

Embodiment 2 A developer detecting device according to the present invention is applied to a laser beam printer of an integral cartridge type of 16 sheets per minute which has the same structure as the image forming apparatus shown in FIG. 1 described in Embodiment 1. Equipment was installed. The cartridge has a life of 10,000 sheets (A4, 4% printing) and an initial developer amount of about 500.
g.

FIG. 11 shows the developing device of the laser beam printer according to this embodiment. The developer remaining amount detection antenna 40 is a flat metal conductor, that is, a metal plate, and is disposed in the developer container 11. The developer remaining amount detectable area 41 is 50% of the initial developer volume.

The developer level is indicated by a developer remaining amount display means 10.
It can be displayed on the operation panel of the laser beam printer as 0 and on a personal computer, and the display is divided into three stages. At this time, the detection voltage Vout changes in the range of 0 to 5 V, and the relationship between the developer amounts at that time is shown in FIG. When the amount of the developer in the cartridge exceeds 250 g from the initial stage, the detection voltage Vout displays a constant value. However, below 250 g, the detection voltage Vout starts to change according to the remaining amount of toner. When the change of the detection voltage Vout starts, the display of the developer remaining amount display unit 100 is changed. After that, according to the detection voltage Vout,
A signal is output from the MPU 56 to change the display of the remaining amount of the developer on the operation panel of the laser beam printer and the personal computer. Further, since the remaining amount of the developer decreases in proportion to the detection voltage Vout, the developer amount can be estimated from the detection voltage Vout. It is also possible to estimate the number of printable sheets at 4% printing from the estimated amount of developer. It is desirable to transmit the remaining printable number to the user as well.

As a result, the remaining amount of the developer can be sequentially and accurately and accurately detected, and the remaining amount of the developer can be constantly transmitted to the user, and the timing of running out of the developer can be transmitted to the user. It has become possible.

In this embodiment, the display level of the developer is set to three levels, but the number of display level switching steps is not particularly limited.

Embodiment 3 A developer detecting device according to the present invention is applied to a laser beam printer of 24 cartridges per minute having the same structure as the image forming apparatus shown in FIG. Equipment was installed. The cartridge has a life of 15,000 sheets (A4, 4% printing), and the initial developer amount is about 800.
g.

FIG. 13 shows a developing device portion of the laser beam printer in this embodiment. In this embodiment, a conductive member is provided near the developing roller 12, and an alternating bias voltage can be applied to this member. As the conductive member, a support member of the elastic blade 17 formed of urethane rubber, that is, a support plate 17A, and further, a support plate 17A
A metal member 17B disposed adjacent to A.
In this embodiment, the same bias voltage as that of the developing roller 12 was applied to the conductive members 17A and 17B.

The developer remaining amount detecting antenna 40 is a flat metal conductor, that is, a metal plate, as in the previous embodiment, and is disposed in the developer container 11 in this embodiment. The counter electrode of the developer remaining amount detection antenna 40 is the developing roller 12,
The elastic blade supporting metal plate 17A and the metal member 17B are provided, and in this embodiment, the developer remaining amount detectable area 41 can be made large. Therefore, in the present embodiment, the developer remaining amount detectable region 41 is enlarged as compared with the case where only the developing roller 12 is used as the counter electrode, and 90% of the initial developer volume is increased.
Met.

The developer level is indicated by a developer remaining amount display means 10.
It can be displayed on the operation panel of the laser beam printer as 0 and on a personal computer, and the display is divided into 10 stages. At this time, the detection voltage Vout changes in the range of 0 to 5 V, and the relationship between the developer amounts at that time is shown in FIG. The amount of developer in the cartridge is 720 g from the beginning
Is outside the range, the detection voltage Vout displays a constant value. However, below 720 g, the detection voltage Vout starts to change according to the remaining amount of the developer. Detection voltage Vout
Is changed, the display of the developer remaining amount display means is changed. After that, according to the detection voltage Vout, MP
A signal is output from U56 to change the display of the toner remaining amount display means 100 on the operation panel of the laser beam printer and the personal computer. Also, in proportion to the detection voltage Vout,
Since the remaining amount of the developer decreases, the amount of the developer can be estimated from the detection voltage Vout. It is also possible to estimate the number of printable sheets at 4% printing from the estimated amount of developer. It is desirable to transmit the remaining printable number to the user as well.

As a result, it is possible to detect the remaining amount of the developer one after another accurately and accurately, so that the remaining amount of the developer is always transmitted to the user, and the time when the developer runs out is transmitted to the user. It has become possible.

In the present embodiment, the display level of the developer is set to ten levels, but the number of display level switching steps is not particularly limited.

Embodiment 4 A developer detecting device according to the present invention is applied to a laser beam printer of an integral cartridge type of 32 sheets per minute which has the same structure as the image forming apparatus shown in FIG. Equipment was installed. The cartridge has a life of 15,000 sheets (A4, 4% printing), and the initial developer amount is about 800.
g.

FIG. 15 shows the developing device of the laser beam printer according to this embodiment. In the present embodiment, similarly to the third embodiment, the elastic blade 1 made of urethane rubber is used.
7 and the developing roller 1 on the supporting metal plate 17A and the metal member 17B.
The same bias voltage as in Example 2 was applied.

In this embodiment, however, the developer remaining amount detecting antenna 40 is a flat metal conductor, that is, a metal plate.
It is attached to the outside of the developer container 11, for example, in close contact with the outside of the developer container itself, or to the cartridge frame, and further to the image forming apparatus main body. With such a configuration, it is possible to increase the area of the developer remaining amount detection antenna 40, and the shape of the developer remaining amount detection antenna 40 does not depend on the shape of the developing device or the cartridge. .

The opposite electrodes of the developer remaining amount detecting antenna 40 are the developing roller 12, the elastic blade supporting plate 17A and the metal member 17B.
Was 80% of the initial developer volume.

The developer level can be displayed on the operation panel of the laser beam printer or on a personal computer, and the display is divided into four stages. At this time, the detection voltage Vou
t changes in the range of 0 to 5 V, and the relationship between the developer amounts at that time is shown in FIG. When the amount of the developer in the cartridge exceeds 600 g from the initial stage, the detection voltage Vo
ut indicates a constant value. However, below 600 g, the detection voltage Vout starts to change according to the remaining amount of the developer. When the change of the detection voltage Vout starts, the display of the remaining amount of the developer is changed. Thereafter, a signal is output from the MPU 56 in accordance with the detection voltage Vout, and the display of the remaining amount of the developer on the personal computer on the operation panel of the laser beam printer is changed. Further, since the remaining amount of the developer decreases in proportion to the detection voltage Vout, the developer amount can be estimated from the detection voltage Vout. It is also possible to estimate the number of printable sheets at 4% printing from the estimated amount of developer. It is desirable to transmit the remaining printable number to the user as well.

As a result, the remaining amount of the developer can be sequentially and accurately detected with high accuracy, and the remaining amount of the developer can be constantly transmitted to the user, and the timing of running out of the developer can be transmitted to the user. It has become possible.

In the present embodiment, the display level of the developer is four levels, but the number of display level switching steps is not particularly limited.

Embodiment 5 According to the present invention, a plurality of developer remaining amount detecting antennas 40 in an image forming apparatus can be arranged. The developer remaining amount detectable area 41 at that time is formed by the individual developer remaining amount detecting antenna 40 and the developing roller 12 as a counter electrode, or by the individual developer remaining amount detecting antenna 40 and the counter electrode. This is the total sum of the remaining developing amount detectable area 41 defined by the developing roller 12, the supporting metal plate 17A of the elastic blade 17, and the metal member 17B. That is, in the present invention,
The total amount of the remaining developing amount detectable region 41 is equal to or greater than 50%, and the detection error of the remaining amount of the developing agent with respect to the change in the amount of the developer due to the consumption of the developer in the remaining developing amount detectable region 41 ± 10% or less.

According to the present embodiment, a laser beam printer of the integral cartridge type of 50 sheets per minute having the same structure as the image forming apparatus shown in FIG. Was installed. The cartridge had a life of 30,000 sheets (A4, 4% printing), and the initial developer amount was about 1500 g.

FIG. 17 shows the developing device of the laser beam printer in this embodiment. In the present embodiment, the developer remaining amount detection antenna 40 is disposed outside the developing container 11 in the same manner as in the fourth embodiment, and is further provided inside the developing container 11 and in the developing roller 12 in the present embodiment. One is disposed at the bottom of the adjacent developer container 11.

Further, in this embodiment, similar to the third embodiment,
The same bias voltage as that of the developing roller 12 was applied to the supporting plate 17A and the metal member 17B of the elastic blade 17 formed of urethane rubber.

Therefore, in this embodiment, the opposite electrodes of the developer remaining amount detecting antenna 40 are the developing roller 12, the elastic blade supporting metal plate 17A and the metal member 17B, and the developer remaining amount detectable area 41 is provided for each developing agent. The total amount of the developer remaining amount detectable areas 41A and 41B defined by the developer remaining amount detecting antennas 40A and 40B and the counter electrode is 75% of the initial developer volume in this embodiment.

The developer level can be displayed on the operation panel of the laser beam printer or on a personal computer, and the display is divided into ten levels. At this time, the detection voltage Vo
ut changes in the range of 0 to 5 V, and the relationship between the developer amounts at that time is shown in FIG. When the amount of the developer in the cartridge exceeds 1125 g from the initial stage, the detection voltage V
“out” indicates a constant value. However, when the voltage falls below 1125 g, the detection voltage Vout starts to change in accordance with the remaining amount of the developer. As shown by the solid line 110 in FIG. 18, when the change in the detection voltage Vout of the developer remaining amount detection antenna 40A starts, the display of the developer remaining amount display unit is changed. Thereafter, when the detection voltage Vout falls below a certain value, the developer remaining amount detection antenna 40A is switched to the developer remaining amount detection antenna 40B, the detection accuracy of the developer remaining amount is increased, and the detection voltage Vout is changed to the detection voltage Vout. In response, a signal is output from the MPU 56 to change the display of the developer remaining amount display means 100 on the operation panel of the laser beam printer or on the personal computer.

Here, as shown in FIG. 18, especially in a large-capacity developing device, that is, a cartridge, the initial developer volume becomes large, and one developer remaining amount detecting antenna 40A
The gradient of the detection voltage Vout detected only by the above becomes smaller as shown by a solid line 110 in FIG. 18, and an error range due to the attachment of the remaining amount detection antenna or the like becomes a dotted line 110a in the figure. At this time, the error near the developer amount T0 at which the developer runs out is T2-T0. on the other hand,
The detection voltage Vout at the developer remaining amount antenna 40B is a solid line 111 in FIG. 18, and the error range is a dotted line 111a in the figure. At this time, the error near the developer amount T0 at which the developer runs out is T1-T0. As is clear from FIG. 18, since the detection error is T2-T0> T1-T0, when the remaining amount of the developer decreases, it is preferable to detect the remaining amount of the developer by the developer remaining amount detection antenna 40B. Can improve the detection accuracy.

Since the remaining amount of the developer decreases in proportion to the detection voltage Vout, the amount of the developer can be estimated from Vout. It is also possible to estimate the number of printable sheets at 4% printing from the estimated amount of developer. It is desirable to transmit the remaining printable number to the user as well.

As a result, it is possible to detect the remaining amount of development sequentially and accurately, and it is possible to always inform the user of the remaining amount of developer and to inform the user of the time when the developer runs out. .

In the present embodiment, the display level of the developer is set to 10 levels, but the display level is not particularly limited. Further, although the number of the developer remaining amount detecting antennas is two, the number is not particularly limited to this, and when there are a plurality of antennas, it is the same as this embodiment.

In this embodiment, the developer remaining amount detecting antenna 40A is mounted outside the developing container and the developer remaining amount detecting antenna 40B is mounted inside the developing device. The same effect can be obtained by attaching the developing unit to the outer wall of the developing container, the cartridge frame, or the main body of the image forming apparatus. In particular, as long as 50% or more of the initial developer volume can be detected, the mounting location is not specified.

Embodiment 6 FIG. 19 shows an embodiment of a developing device in the form of a cartridge which is another embodiment of the present invention.

The developing device 10 of this embodiment includes a developer carrier 12 such as a developing roller, and a developing unit 1 having a toner therein for supplying a developer to the developer carrier 12.
It has a developing container 11 having a hopper portion 3 and a hopper portion 14 and is integrally made into a cartridge. That is, the developing device of the present embodiment is obtained by unitizing the developing device components of the process cartridge B described in the first embodiment, that is, from the process cartridge B to the photosensitive drum 1, charging means 2,
The cartridge can be considered as an integrated cartridge except for the cleaning means 6. Therefore, all the configurations of the developing device and the configuration of the developer amount detecting means described in the first embodiment are similarly applied to the developing device of the present embodiment. Therefore, for the description of these configurations and operations, the above description performed in Example 1 is cited.

Of course, also in the present embodiment, a developer remaining amount detecting means similar to that described in the first embodiment is provided, and the remaining amount of the developer can be sequentially detected with high accuracy.

In the present invention, when the amount of the developer stored in the container is initially set to 100%, the amount of the developer is sequentially detected over the entire region from 100% to 0%. However, the present invention is not limited to this. For example, the developer may be sequentially detected over a region where the remaining amount of the developer in the container is 50% to 0%. Here, the remaining amount of the developer is 0%
Does not mean that the developer has completely disappeared. For example, the remaining amount of the developer of 0% includes that the remaining amount of the developer is reduced to such an extent that a predetermined image quality (development quality) cannot be obtained even if the developer remains in the container. It is.

[0109]

As described above, the developing device, the process cartridge and the electrophotographic image forming apparatus of the present invention have a structure in which the amount of developer remaining in the developing device is detected by the main body of the electrophotographic image forming apparatus. A developer detecting electrode disposed opposite the body, and a developer remaining amount detectable area defined by the developer carrying member and the developer detecting electrode is the initial developer volume in the developing container. The configuration is such that the detection error of the remaining amount of the developer is ± 10% or less with respect to a change in the amount of the developer due to the consumption of the developer in the developer remaining amount detectable region. With such a structure, it is possible to accurately and accurately detect the state from the full state of the developer to the near-end state immediately before the printing failure, and to improve the convenience of the user when using the apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram of an embodiment of a developing device provided in the image forming apparatus according to the present invention.

FIG. 3 is a diagram showing an embodiment of a developer amount measuring circuit for a developer remaining amount detecting device according to the present invention.

FIG. 4 is a graph showing a relationship between an output from a developer remaining amount detecting device according to the present invention and a developer amount.

FIG. 5 is a diagram illustrating an embodiment of a developer amount display unit.

FIG. 6 is a view showing another embodiment of the developer amount display means.

FIG. 7 is a view showing another embodiment of the developer amount display means.

FIG. 8 is a schematic configuration diagram of a developing device for describing an operation of the developer remaining amount detecting device according to the present invention.

FIG. 9 is a schematic configuration diagram of a developing device for describing an operation of the developer remaining amount detecting device according to the present invention.

FIG. 10 is a graph showing the relationship between the output from the developer remaining amount detecting device and the amount of developer for explaining the operation of the developer remaining amount detecting device according to the present invention.

FIG. 11 is a schematic configuration diagram of another embodiment of the developing device according to the present invention.

12 is a graph showing a relationship between an output from a developer remaining amount detection device and a developer amount in the developing device of FIG. 11;

FIG. 13 is a schematic configuration diagram of another embodiment of the developing device according to the present invention.

14 is a graph showing a relationship between an output from a developer remaining amount detecting device and a developer amount in the developing device of FIG. 13;

FIG. 15 is a schematic configuration diagram of another embodiment of the developing device according to the present invention.

16 is a graph showing a relationship between an output from a developer remaining amount detecting device and a developer amount in the developing device of FIG.

FIG. 17 is a schematic configuration diagram of another embodiment of the developing device according to the present invention.

18 is a graph showing a relationship between an output from a developer remaining amount detecting device and a developer amount in the developing device of FIG. 17;

FIG. 19 is a schematic configuration diagram of an embodiment of a developing device according to the present invention.

FIG. 20 is a schematic configuration diagram of a conventional image forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor (photosensitive drum) 2 Charging means 3 Optical means 4 Transfer means 6 Cleaning means 10 Developing device 11 Developing container 12 Developer carrier (Developing roller) 12A Alternating bias power supply (Bias voltage applying means) 13 Developing section 14 Hopper part 15A, 15B Stirrer 17 Developer regulating means (elastic blade) 17A Elastic blade support sheet metal (conductive member) 17B Metal member (conductive member) 40 Electrode for developer detection (developer remaining amount detection antenna) 41 Development Agent remaining amount detectable area 50 Developer amount measuring circuit (developer amount detecting means) 51, 52 Capacitance detecting circuit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Seishi Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H077 AA12 AA20 AB03 AB13 AB15 AB18 AC03 AD02 AD06 AD13 AD17 AD23 AD32 AD36 BA02 BA03 BA08 DA15 DA36 DA58 DA59 DA80 DB08 FA26

Claims (36)

[Claims] 1. An electrophotographic image forming apparatus main body,
In a developing device used for developing an electrostatic latent image formed on an electrophotographic photosensitive member, a developer is stored for developing the electrostatic latent image formed on the electrophotographic photosensitive member. A developer container having a developer carrier for transporting the developer to the electrophotographic photoreceptor; and a developer container arranged to face the developer carrier so as to detect the remaining amount of the developer in the electrophotographic image forming apparatus main body. A developer detection electrode, wherein a developer remaining amount detectable area defined by the developer carrier and the developer detection electrode has an initial developer volume of 50% in the developer container. %, And a detection error of the remaining amount of the developer is ± 10% or less with respect to a change in the amount of the developer accompanying the consumption of the developer in the developer remaining amount detectable region. . 2. The method according to claim 1, wherein the developer detecting electrode has at least two electrodes.
Are provided, and the sum of the developer remaining amount detectable areas defined by the developer carrying member and each of the developer detecting electrodes opposed to the developer carrying member is an initial value in the developing container. The developer remaining amount is 50% or more, and a detection error of the remaining amount of the developer is ± 10% or less with respect to a change in the amount of the developer accompanying the consumption of the developer in the developer remaining amount detectable region. The developing device according to claim 1, wherein: 3. The developing device according to claim 1, wherein a conductive member is provided near the developer carrying member so as to face the developer detecting electrode. 4. The developing device according to claim 3, wherein said conductive member includes a metal support member of a regulating means for regulating a developer layer on said developer carrier. 5. The developer detection electrode outputs an electric signal according to a capacitance between the developer detection electrode and the developer carrier, which is generated when a voltage is applied to the developer carrier. The developing device according to claim 1, wherein the developer is transmitted to a developer amount detecting unit provided in the main body of the electrophotographic image forming apparatus for detecting a remaining amount of the developer. 6. The developer detection electrode, the developer detection electrode generated when a voltage is applied to the developer carrier and the conductive member, and the developer carrier and the conductive member. 4. An electric signal according to a capacitance between the developer and the developer is transmitted to a developer amount detecting means provided in the main body of the electrophotographic image forming apparatus for detecting a remaining amount of the developer.
Or the developing device of 4. 7. The developing device according to claim 1, wherein the developer carrier is a developing roller. 8. The developing device according to claim 1, wherein the voltage applied to the developer carrier is an alternating bias voltage. 9. The method according to claim 3, wherein the voltage applied to the conductive member is an alternating bias voltage.
Or 7, the developing device. 10. The developing device according to claim 8, wherein the alternating bias voltage is a developing bias voltage obtained by superimposing a DC voltage on an AC voltage. 11. The metal plate member according to claim 7, wherein the developer detecting electrode is a metal plate-like member arranged to extend along a longitudinal direction of the developing roller. The developing device according to the item. 12. A process cartridge detachably mountable to an electrophotographic image forming apparatus main body, wherein: (a) an electrophotographic photosensitive member; and (b) an electrostatic latent image formed on the electrophotographic photosensitive member, for developing the electrostatic latent image. A developing device having a developing container containing a developer and a developer carrier for transporting the developer to the electrophotographic photoreceptor; and (b) measuring the remaining amount of the developer in the electrophotographic image forming apparatus main body. And a developer detection electrode disposed opposite to the developer carrier for detecting the amount of developer remaining defined by the developer carrier and the developer detection electrode. The detectable area is equal to or more than 50% of the initial developer volume in the developing container, and the amount of the remaining developer is changed with respect to a change in the amount of the developer accompanying the consumption of the developer in the remaining amount of the developer. The detection error is less than ± 10% Russia Seth cartridge. 13. A developer provided with at least two or more developer detection electrodes, the developer being defined by the developer carrier and each of the developer detection electrodes facing the developer carrier. The sum of the remaining amount detectable area is equal to or more than 50% of the initial developer volume in the developing container, and the developing amount is changed with respect to a change in the amount of the developer accompanying the consumption of the developer in the remaining amount of the developer. 13. The process cartridge according to claim 12, wherein a detection error of the remaining amount of the agent is ± 10% or less. 14. The process cartridge according to claim 12, wherein a conductive member is provided near the developer carrying member so as to face the developer detecting electrode. 15. The process cartridge according to claim 14, wherein said conductive member includes a metal support member of a regulating means for regulating a developer layer on said developer carrier. 16. The developer detection electrode outputs an electric signal according to a capacitance between the developer detection electrode and the developer carrier, which is generated when a voltage is applied to the developer carrier. 14. The process cartridge according to claim 12, wherein the process cartridge transmits the amount of developer remaining in the main body of the electrophotographic image forming apparatus to detect a remaining amount of developer. 17. The developer detection electrode, wherein the developer detection electrode generated when a voltage is applied to the developer carrier and the conductive member, and the developer carrier and the conductive member 16. The process according to claim 14, wherein an electric signal corresponding to a capacitance between the two is transmitted to a developer amount detecting unit provided in the electrophotographic image forming apparatus main body for detecting a remaining amount of the developer. cartridge. 18. The process cartridge according to claim 12, wherein said developer carrier is a developing roller. 19. The voltage applied to the developer carrier is:
13. An alternating bias voltage.
Item 18. The process cartridge according to any one of Items 18. 20. The apparatus according to claim 14, wherein the voltage applied to the conductive member is an alternating bias voltage.
5, 17 or 18 process cartridges. 21. The process cartridge according to claim 19, wherein the alternating bias voltage is a developing bias voltage obtained by superimposing a DC voltage on an AC voltage. 22. The developer detecting electrode according to claim 18, wherein the developer detecting electrode is a metal plate-like member arranged to extend along a longitudinal direction of the developing roller. The process cartridge according to the item. 23. The apparatus according to claim 12, further comprising a charging member for charging the electrophotographic photosensitive member.
23. The process cartridge according to any one of Items 22 to 22. 24. The process cartridge according to claim 12, further comprising a cleaning member for removing a developer attached to the electrophotographic photosensitive member. 25. An electrophotographic image forming apparatus for forming an image on a recording medium, comprising: (a) an electrophotographic photosensitive member;
(B) an electrostatic latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member, and (c) a developer for developing the electrostatic latent image formed on the electrophotographic photosensitive member. And a developing device having a developing container provided with a developer carrier for transporting the developer to the electrophotographic photosensitive member, and (d) detecting the remaining amount of the developer by the electrophotographic image forming apparatus main body. (E) bias voltage applying means for applying an alternating bias voltage to the developer carrier, and (f) the developer Measuring a capacitance between the carrier and the developer detection electrode, and a developer amount detection unit for grasping a developer amount,
The developer remaining amount detectable area defined by the developer carrier and the developer detecting electrode is 50% or more of the initial developer volume in the developing container, and the developer remaining amount is An electrophotographic image forming apparatus, wherein a detection error of the remaining amount of the developer is ± 10% or less with respect to a change in the amount of the developer accompanying consumption of the developer in the detectable region. 26. An electrophotographic image forming apparatus for detachably attaching a process cartridge and forming an image on a recording medium, comprising: (a) an electrophotographic photosensitive member; and an electrostatic member formed on the electrophotographic photosensitive member. And a developing device having a developing container having a developer carrier for storing the developer and transporting the developer to the electrophotographic photosensitive member for developing the latent image. Mounting means for mounting on the electrophotographic image forming apparatus; and (b) detecting the remaining amount of developer by the electrophotographic image forming apparatus main body.
(C) an electrostatic latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member, and (d) the developing device. Bias voltage applying means for applying an alternating bias voltage to the agent carrier,
(E) a developer amount detecting means for measuring a capacitance between the developer carrying member and the developer detecting electrode and grasping a developer amount, wherein the developer carrying member and the developer The developer remaining amount detectable area defined by the detection electrode is 50% or more of the initial developer volume in the developing container, and the development accompanying the developer consumption in the developer remaining amount detectable area is performed. ± 10% detection error of remaining amount of developer with respect to change in amount of developer
An electrophotographic image forming apparatus characterized by the following. 27. A developer provided with at least two or more developer detecting electrodes, the developer being defined by the developer carrying member and each of the developer detecting electrodes facing the developer carrying member. The sum of the remaining amount detectable area is equal to or more than 50% of the initial developer volume in the developing container, and the developing amount is changed with respect to a change in the amount of the developer accompanying the consumption of the developer in the remaining amount of the developer. 27. The electrophotographic image forming apparatus according to claim 25, wherein a detection error of the remaining amount of the agent is ± 10% or less. 28. The electrophotographic image forming apparatus according to claim 25, wherein an electroconductive member is provided near said developer carrying member so as to face said developer detecting electrode. 29. An electrophotographic image forming apparatus according to claim 28, wherein said conductive member includes a metal support member of a regulating means for regulating a developer layer on said developer carrier. 30. The developer detection electrode outputs an electric signal corresponding to a capacitance between the developer detection electrode and the developer carrier generated when a voltage is applied to the developer carrier. 28. The electrophotographic image forming apparatus according to claim 25, wherein the information is transmitted to a developer amount detecting means provided in the electrophotographic image forming apparatus main body for detecting a remaining amount of the developer. 31. The developer detection electrode, wherein the developer detection electrode generated when a voltage is applied to the developer carrier and the conductive member; and the developer carrier and the conductive member. 30. The electronic device according to claim 28, wherein an electric signal corresponding to a capacitance between the two is transmitted to a developer amount detecting unit provided in the electrophotographic image forming apparatus main body for detecting a remaining amount of the developer. Photographic image forming device. 32. An electrophotographic image forming apparatus according to claim 25, wherein said developer carrier is a developing roller. 33. The electrophotographic image forming apparatus according to claim 28, wherein the voltage applied to the conductive member is an alternating bias voltage applied to the developer carrier. 34. An electrophotographic image forming apparatus according to claim 33, wherein said alternating bias voltage is a developing bias voltage obtained by superimposing a DC voltage on an AC voltage. 35. The developing agent detecting electrode according to claim 32, wherein the developing roller is a metal plate-like member arranged to extend along a longitudinal direction of the developing roller.
4. The electrophotographic image forming apparatus of item 4. 36. The developer amount detecting means has a reference capacitance substantially equal to a minimum value of a capacitance formed between the developer carrier and the developing-seat detecting electrode. A capacitance detection circuit for measuring a reference capacitance, a capacitance detection circuit for measuring a capacitance between the developer carrier and the electrode for detecting the developing seat, and a capacitance measured by both circuits. 36. The electrophotographic image forming apparatus according to claim 25, further comprising: a differential circuit for comparing.