JP2001134064A - Image forming device, cartridge that is attachble to/ detachable from the image forming device and image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that image failure such as a void due to detection error of residue quantity of developer, and waste of the developer are eliminated so that residue quantity of developer inside a develop ing device is accurately detected and an appropriate exchange timing for a processing cartridge is given to a user and a cartridge and an image forming system that can be attached to/detached from the image forming device. SOLUTION: Relating to the image forming device A that the cartridge B provided with a developer containing part 4, a developer quantity detecting means 30 capable of sequentially outputting a signal correspondent to quantity of the developer inside the developer containing part 4 and a storage means 20 can be attached to/detached from the device, information corresponding to output when a maximum quantity of the developer is detected by the developer quantity detecting means 30 is stored in the storing means 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an image forming apparatus using an electrophotographic system, and a cartridge mountable on the main body of the image forming apparatus, that is, a process cartridge, a developing device formed into a cartridge, and the like. ,
The present invention relates to an image forming apparatus for detecting a remaining amount of a developer using a storage unit mounted on a cartridge, a cartridge detachable from the image forming apparatus, and an image forming system.

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.

The cartridge detachably mountable to the main body of the electrophotographic image forming apparatus includes an electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, developing means for supplying a developer to the electrophotographic photosensitive member, and electrophotographic photosensitive member. This means at least one of the cleaning means for cleaning the body. In particular, the process cartridge is
At least one of the charging unit, the developing unit, and the cleaning unit, and the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge is detachable from the main body of the electrophotographic image forming apparatus. The means and the electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is detachable from the main body of the electrophotographic image forming apparatus.

[0004]

2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus such as an electrophotographic copying machine or a laser beam printer forms a latent image by irradiating an electrophotographic photosensitive member with light corresponding to image information. The image is formed on the recording medium by supplying a developer (including toner) using a developing unit 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, an electrophotographic photosensitive member and a process means acting on the electrophotographic photosensitive member are used in order to facilitate replacement of consumables such as an electrophotographic photosensitive member and a developer and maintenance. There is a process cartridge system in which the developing means, the charging means, the cleaning means, the developer accommodating container and the waste developer container are integrated as a process cartridge and can be detachably attached to the image forming apparatus main body. 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 is widely used in electrophotographic image forming apparatuses.

For example, in a color image forming apparatus having a plurality of color developing means, when each developing means has a different degree of consumption, a developing cartridge of each color is formed as a cartridge with the developing means of each color and a developer accommodating container. There is a printer which is detachable from the image forming apparatus and can be replaced individually.

In such a cartridge type image forming apparatus, the user can form an image again by replacing the cartridge when the developer runs out, for example. Therefore, such an image forming apparatus may include a unit for detecting when the developer is consumed and notifying the user, that is, a developer amount detecting device.

[0008] The developer amount detecting device is capable of detecting the remaining amount of the developer in order to be able to know at any time how much developer remains in the cartridge for image formation. The detecting means is provided in the cartridge or the image forming apparatus main body.

[0009] In particular, there is an apparatus in which the convenience of the user is further improved by not only notifying the user that the developer has run out but also sequentially detecting and notifying the amount of the developer. In such an image forming apparatus, the percentage of the developer remaining when not in use is calculated and reported to the user one by one, or the developer is reduced to such an extent that a predetermined quality image cannot be formed. Is displayed to warn the user that the developer is running low before an image defect occurs.

As one type of the developer remaining amount detecting means,
There is a plate antenna system. This plate antenna system is, for example, a cartridge adopting a developing system in which an AC bias is applied to a developer carrying member provided in a developing unit to develop a latent image formed on an electrophotographic photosensitive member. Provided at a location facing the carrier or at a plurality of other locations, the electrostatic capacity between the sheet metal and the developer carrier and between the sheet metal and the sheet metal is set to a value such as an insulating toner. This is based on the fact that it changes according to the amount of the agent.

That is, if the space between the sheet metal and the developer carrier or the space between the sheet metal and the sheet metal is filled with the developer, the capacitance between them increases, and as the developer decreases, the capacitance between the two increases. The rate at which air occupies the intervening space increases, and the capacitance decreases. Therefore, if the capacitance between the sheet metal and the developer carrier or the relationship between the capacitance between the sheet metal and the developer amount is determined in advance, the developer amount level can be detected by measuring the capacitance. can do.

The capacitance is measured by measuring a current flowing through a sheet metal provided opposite to the developer carrier when an AC bias is applied to the developer carrier. Alternatively, when a plurality of sheet metals are provided, the capacitance between the sheet metals can be similarly measured by measuring the current flowing in the other sheet metal when an AC bias is applied to the sheet metal as an electrode. it can. In most cases, the plate antenna type developer amount detecting device detects the developer amount during image formation in which a developing bias is applied to the developer carrier.

[0013]

However, as described above, even if the developer remaining amount detecting means capable of detecting the developer remaining amount level is provided, the developer remaining amount detected by the developer remaining amount detecting means is detected. In some cases, the value does not match the amount of the developer actually remaining in the developing device, that is, the remaining amount of the developer cannot be accurately detected.

For example, in the case of the above-described plate antenna type developer amount detecting device, the capacitance between the developer carrier and the metal plate as the electrode or the capacitance between the metal plate as the electrode is respectively It depends on the positional relationship. That is, even when there is no developer in the developing device, the absolute value of the capacitance increases as the distance between the two increases, and decreases as the distance between the two increases. As a result, the developer amount detection value may vary among the cartridges due to a tolerance of a sheet metal as a developer remaining amount detecting unit. Further, the developer amount detection value varies due to the manufacturing lot of the developer accommodated in the developing device, the usage environment, the tolerance of the components of the cartridge, the electronic components of the image forming apparatus main body, and the like.

Therefore, when the remaining amount level of the developer is detected by using a predetermined relationship between the detected value of the capacitance and the amount of the developer, the detection result indicates that the developing result actually remains in the developing device. There may be a problem that the amount is far from the amount of the agent.

That is, when the developing device is fully filled with the developer (when the developer is full), that is, when the use of the process cartridge is started, the capacitance detection value by the developer remaining amount detecting means is set. In the case of a process cartridge that is larger than the value (estimated value), the developer amount detection device always detects a value estimated more than the actual remaining amount of the developer through the use of the process cartridge. Before the user is warned, the developer becomes smaller than a predetermined value, and a so-called blank image is generated.

Conversely, in the case of a process cartridge in which the detected value of the capacitance when the developer is full is smaller than the set value, the developer amount detecting device always estimates the actual remaining amount of the developer to be smaller than the actual remaining amount through the use of the process cartridge. Since the value is detected, a warning of "no developer" may be issued even though a lot of developer remains in the developing device. If the user replaces the process cartridge in accordance with the warning, a large amount of toner is wasted, which leads to waste of resources. The present invention has been made in view of such a problem.

Accordingly, it is a primary object of the present invention to provide an image forming apparatus capable of accurately detecting the remaining amount of developer in a developing apparatus, a cartridge detachable from the image forming apparatus, and an image forming system. It is.

It is another object of the present invention to accurately detect the remaining amount of the developer in the developing device and notify the user of the remaining amount, thereby notifying the user of an appropriate process cartridge replacement time. Image forming apparatus capable of eliminating image defects such as white spots due to erroneous detection of the remaining amount of developer and waste of developer, a cartridge detachably mountable to this image forming apparatus, and image forming Is to provide a system.

[0020]

The above object is achieved by an image forming apparatus according to the present invention, a cartridge detachable from the image forming apparatus, and an image forming system. In summary, according to the first aspect of the present invention, a developer accommodating section, a developer amount detecting section capable of sequentially outputting a signal corresponding to an amount of the developer in the developer accommodating section, and a storage section are provided. An image forming apparatus in which a cartridge having a detachable cartridge is provided, wherein information corresponding to an output when the developer remaining amount detecting means detects the maximum amount of developer is stored in the storage means. Provided.

According to one embodiment of the present invention, the image forming apparatus further includes information corresponding to an output when the developer remaining amount detection means stored in the storage means detects the maximum amount of developer. An output of the developer remaining amount detecting means;
, The amount of developer in the developer accommodating section is sequentially detected.

According to another embodiment of the present invention, the image forming apparatus is configured to detect the maximum amount of the developer from the output when the developer remaining amount detection unit stored in the storage unit detects the maximum amount of the developer. The remaining amount of the developer is detected based on the amount of change in the output of the developer remaining amount detecting means. Further, according to a preferred embodiment, a change amount of an output of the developer remaining amount detecting unit from an output when the developer remaining amount detecting unit stored in the storage unit detects the maximum amount of the developer is , At least the amount of developer is detected using a table corresponding to the amount of developer. According to one embodiment, the table is stored in the storage unit.

According to another embodiment of the present invention, the image forming apparatus includes a weighting function based on an output when the developer remaining amount detection means stored in the storage means detects the maximum amount of developer. And the output of the developer remaining amount detecting means to detect the amount of developer.

According to the preferred embodiment of the present invention,
The developer remaining amount detecting means outputs a signal obtained by measuring a capacitance between at least two electrodes. According to a preferred embodiment, the image forming apparatus further includes a display unit, and a signal for displaying information on the detected remaining amount of the developer is transmitted to the display unit and displayed. According to another embodiment, the image forming apparatus can further communicate with a device having a display unit, and transmits a signal for displaying information on the detected remaining amount of the developer to the device having the display unit. I do.

According to the second aspect of the present invention, the developer accommodating portion, the developer amount detecting means capable of sequentially outputting a signal corresponding to the developer amount in the developer accommodating portion, the storage means,
Wherein the storage means stores information corresponding to an output when the developer remaining amount detecting means detects the maximum amount of the developer. Is provided. According to a preferred embodiment of the present invention, the storage means further includes: a developer remaining amount from an output when the developer remaining amount detection means stored in the storage means detects a maximum amount of the developer. A table is stored in which the amount of change in the output of the detecting means is associated with at least the amount of developer.

According to a third aspect of the present invention, there is provided an image forming system for forming an image on a recording medium by using a cartridge which is detachable from an image forming apparatus. A developer amount detecting means capable of sequentially outputting a signal corresponding to the amount of the developer, and a storage means for storing information corresponding to an output when the developer remaining amount detecting means detects the maximum amount of the developer. And a cartridge having
(B) based on the information corresponding to the output when the remaining amount of developer stored in the storage unit detects the maximum amount of the developer and the output of the remaining amount of developer, An image forming system comprising: a control unit configured to sequentially detect an amount of the developer in the developer storage unit. According to a preferred embodiment of the present invention, the image forming system further includes a display unit for displaying information on the detected amount of the developer.

In the present invention, preferably,
The storage means is a nonvolatile memory, a non-contact type nonvolatile memory, or a volatile memory provided with a power supply. In each of the present invention, the cartridge further includes an electrophotographic photosensitive member, a charging unit for charging the electrophotographic photosensitive member, a developing unit for supplying a developer to the electrophotographic photosensitive member, and a cleaning unit for cleaning the electrophotographic photosensitive member. At least one of the cleaning means.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus, a cartridge detachable from the image forming apparatus and an image forming system 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 A, receives image information from a host computer, and performs a recording medium, for example, a recording paper, an OHP sheet, by an electrophotographic image forming process. An image is formed on a cloth or the like.

The laser beam printer A has a drum-shaped electrophotographic photosensitive member, that is, a photosensitive drum 1. The photoconductor drum 1 is charged by a charging roller 2 serving as a charging unit, and then a laser beam L corresponding to the image information is emitted from a laser scanner 3 so that a latent image corresponding to the image information is formed on the photoconductor drum 1. It is formed. This latent image is developed by the developing device C by the developing unit 5 to form a visible image,
That is, the image is a toner image.

That is, the developing device C has, as a developer accommodating section, a developing chamber 5A having a developing roller 5a as a developer carrier, and a developer accommodating container 4 formed adjacent to the developing chamber 5A. The developer T in the developer container 4 is supplied to the developing roller 5a of the developing chamber 5A. The stirring means 1 rotating in the direction of the arrow in FIG.
The stirring device 15 rotates, and the developer T is supplied to the developing roller 5a while being loosened. In this embodiment, as the developer T, an insulating magnetic one-component toner was used. The developing roller 5a includes a fixed magnet 5
b, the developer is transported by rotating the developing roller 5a, and is triboelectrically charged by a developing blade 5c, which is a developer layer thickness regulating member, to form a developer layer having a predetermined thickness. Is supplied to the developing area of the photosensitive drum 1. The developer supplied to the developing area is transferred to a latent image on the photosensitive drum 1 to form a toner image. The developing roller 5a is connected to a developing bias applying unit 34 (FIG. 2), and is usually applied with a developing bias voltage in which a DC voltage is superimposed on an AC voltage.

On the other hand, the recording medium P set in the sheet cassette 200 is conveyed to the transfer position via the pickup roller 8 and the conveying means 9A in synchronization with the formation of the toner image. At the transfer position, a transfer roller 6 as a transfer unit is disposed, and by applying a voltage, the photosensitive drum 1 is moved.
The upper toner image is transferred to the recording medium P.

The recording medium P to which the toner image has been transferred is conveyed to the fixing unit 10 by the conveying unit 9B. Fixing means 10
Is provided with a fixing roller 10b and a drive roller 10c each having a built-in heater 10a, and applies heat and pressure to the recording medium P passing therethrough to fix the transferred toner image on the recording medium P.

The recording medium P is discharged to the discharge tray 14 by the conveying means 9c. The discharge tray 14 is provided on the upper surface of the apparatus main body 100 of the laser beam printer A.

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

On the other hand, in the present embodiment, as shown in FIG. 2, the process cartridge B includes a developer accommodating container 4 for accommodating a developer and a developer frame 11 having a stirring means 15.
And a developing frame 12 for holding a developing means 5 such as a developing roller 5a and a developing blade 5c are welded together to form a developing unit (developing device) C. , Cleaning blade 7a
The cleaning unit 7 such as the waste developer container 7b and the charging roller 2 are integrally connected to form a cartridge.

The process cartridge B is removably mounted on a cartridge mounting means 101 (FIG. 1) provided on the image forming apparatus main body 100 by a user.

According to the present invention, the laser beam printer A is provided with a developer amount detecting device provided with a developer remaining amount detecting means capable of sequentially detecting the remaining amount of the developer T in the developing device C according to consumption. Have.

According to the present embodiment, the developer remaining amount detecting means 3
0 indicates a plate antenna. As shown in FIG. 2, in the present embodiment, an output plate 32 provided as a plate antenna at a position facing the developing roller 5 a over the entire area in the longitudinal direction of the developing device C;
And an input sheet metal 31 provided to be opposed to the output sheet metal 32.

The input sheet metal 31 and the output sheet metal 32 as the plate antenna can be basically used without any particular limitation as long as they can pass a current. In this embodiment, the sheet metals 31 and 32 are used. SUS is used as a material for rust.

In this embodiment, the developing roller 5a and the input metal plate 31 are connected to the developing bias as a voltage applying means provided in the image forming apparatus main body 100 in a state where the process cartridge B is mounted on the image forming apparatus main body 100. It is electrically connected to the application means 34.

Then, the normal developing bias of 2 KH
When an AC bias of about z and a DC bias of about -400 V are applied to the developing roller 5a and the input sheet metal 31, the developing roller 5a and the output sheet metal 32 opposed to the developing roller 5a.
, And between the input sheet metal 31 and the output sheet metal 32, and the current measuring device 33 measures the combined current value of the two. Thus, based on the current value measured by the current measuring device 33, the developing roller 5a and the output
And the combined capacitance based on the capacitance between the input sheet metal 31 and the output sheet metal 32.

As described above, the input sheet metal 31 and the output sheet metal 32, which are plate antennas, are disposed in the developing device C, and as the developer T in the developing device C decreases, the input sheet metal 31 and the output sheet metal 32 By observing the capacitance between the developing roller 5a and the output sheet metal 32 during this period, the developer amount in the developer accommodating container 4 can be known at any time.

Here, in the following description, the capacitance between the developing roller 5a and the output plate 31 and the input plate 3
A signal finally output via the output metal plate 32 in accordance with the capacitance between the output metal plate 1 and the output metal plate 32 is simply referred to as a “signal from the developer remaining amount detecting unit” or a “developer remaining amount detecting unit”. And the like.

According to the present embodiment, as shown in FIG. 3, the current from the developer remaining amount detecting means 30 is measured by the current measuring device 33 provided in the image forming apparatus main body 100, and the current is supplied to the image forming apparatus main body 100. It is sent to the disposed main body control unit 22. The main body control unit 22 includes a developer remaining amount detecting unit 30.
Is converted into a voltage signal by the main body-side developer amount detection unit 23, and as described later in detail, the calculation unit 2
4. The remaining amount level of the developer is determined using the control means 25 and the developer remaining amount correction table 26. Also, the main body control unit 22
Calculates the remaining percentage of the developer based on the detected remaining amount of the developer, and displays the information on the display means 40 of the apparatus main body 100 or the fact that the developer has decreased to such an extent that a predetermined quality image cannot be formed. A warning of "no developer" to be notified to the user is displayed.

Next, the principle of detecting the remaining amount of the developer by the developer amount detecting device of this embodiment will be described in more detail.

In this embodiment, the detected capacitance value from the developer remaining amount detecting means 30 is determined by the current measuring device 33 as described above.
The main body side developer remaining amount detection unit 2 in the main body control unit 22 through the
3 and is converted into a voltage value (hereinafter, the voltage value detected by the main body control unit 22 of the image forming apparatus main body 100 based on the output of the remaining developer amount detecting means 30 is simply referred to as a “detected voltage value”. ").

In the developer amount detecting device of this embodiment, for example, a voltage value as shown in FIG. 4 is output according to the amount of the developer in the developing device C. In FIG. 4, the vertical axis represents a portion between the developing roller 5 a as the developer remaining amount detecting means 30 and the output sheet metal 32,
The detected voltage value corresponds to the sum of the capacitance values measured between the input sheet metal 31 and the output sheet metal 32, and the horizontal axis indicates the remaining amount of the developer in the developing device C. or,
FIG. 4 shows two actual measured values as an example of an ideal curve (− ○ −) of the detected voltage value by the developer amount detecting device and an example in which the detected voltage value due to the individual difference of the cartridge deviates from the ideal value as described later. , PA1 (-□-) and PA2 (-△
-). Here, in the present embodiment, (capacitance, detection voltage) = (13 pF, 1.0 V)
(18 pF, 0.8 V) As shown in the following expression, the decrease / increase relationship between the detection voltage and the combined capacitance of the capacitance between the developing roller 5 a and the output plate 32 and between the input plate 31 and the output plate 32 is as follows. , In the opposite relationship,
The detection voltage is set to be small when the capacitance detected by the developer remaining amount detection means 30 is large, and to be large when the capacitance is small.

That is, as shown in FIG.
a and the output metal plate 32 and between the input metal plate 31 and the output metal plate are fully filled with the developer, the detected capacitance value indicates the maximum value, and at this time, the detected voltage The value indicates the minimum value (hereinafter, the minimum value of the voltage value detected by the developer remaining amount detection device is referred to as “PAF value: (plate antenna full value)”).

In this embodiment, the developer remaining amount detecting means 3
0, the developing roller 5a, the output sheet metal 32 relatively close to the developing roller 5a, and the input sheet metal 31 relatively close to the output sheet metal 32 are used. As shown, the detection voltage starts to decrease after the developer in the developing and developing device C is consumed by about half or less, and thereafter, the remaining amount of the developer can be sequentially detected in a range until the developer runs out. However, the present invention is not limited to this, and as the developer remaining amount detecting means 30, for example, an input electrode and an output electrode formed of a plate antenna or the like as in the present embodiment may be provided at arbitrary positions in the developing device. By measuring the capacitance between the two electrodes and measuring the capacitance between the two electrodes, the range from the point when the remaining amount of the developer is larger until it disappears can be naturally detected.

As described above, in the plate antenna type developer remaining amount detecting means, the capacitance between the developer carrier and the metal plate as the electrode or the capacitance between the metal plate as the electrode is used. Is dependent on the positional relationship between them, and the difference between the individual cartridges may cause variations in the developer amount detection value using the developer remaining amount detecting means.
Variations in the developer amount detection result also occur due to the manufacturing lot of the contained developer, the use environment, the tolerance of the cartridge components, the electronic components of the image forming apparatus main body, and the like.

To further explain, such a difference between the individual cartridges may be caused, for example, by a deviation in the positional relationship between the plate antennas or the like, between the developing roller 5a and the output plate 32 and between the input plate and the output plate 32. The detection voltage value in the state where there is no agent will be different. As a result, the detected voltage values in a state where the developer is fully filled between the developing roller 5a and the output sheet metal 32 and between the input sheet metal and the output sheet metal 32 vary. Further, even when there is no deviation in the positional relationship of the plate antennas, as described above, the detection of the developer in a full state between the cartridges is also caused by the manufacturing lot of the developer and the tolerance of the electronic components of the image forming apparatus main body. The voltage value varies.

That is, the ideal value (− ○ −) and the actually measured values PA1 (− □ −) and PA2 (− △ −) are, for example, as shown in FIG. In the state, the minimum value (PAF value) of the detection voltage corresponding to the maximum value of the capacitance detected by the developer remaining amount detecting means 30 is different. Is 1.0 V for the actually measured value PA1 and 0.6 V for the actually measured value PA2.

As can be understood from FIG. 4, even if the detection voltage varies as described above, in any case, the curved shape of the relationship between the detection voltage and the remaining amount of the developer is accommodated in the developing device C. If the developer amount is the same, the detected voltage value is the same as the actual measured values PA1 (-□-) and PA2 (-△-) shown in FIG. The curve (-○-) is relatively displaced.

The ideal value (-○-) shown in FIG.
Table 1 shows data of the remaining amount of the developer and the detected voltage at A1 (-□-) and the actually measured value PA2 (-△-).

[0056]

[Table 1] As described above, since the detection voltage is shifted due to individual differences between the process cartridge B or the image forming apparatus due to various causes, a predetermined capacitance (detection voltage value) is set.
When the developer remaining amount level is detected using the relationship between the detected value and the amount of the developer, a problem occurs that the amount of the developer actually remaining in the developing device C and the detection result are far apart. There are cases.

That is, when the remaining amount of the developer is determined based only on the ideal curve of the relationship between the remaining amount of the developer and the detection voltage as shown in FIG. 4 and Table 1, for example, the following is obtained. Failure occurs. (A) When the developer amount detecting device has an output characteristic such as the actually measured value PA1 (-□-), that is, the PAF value is larger than the ideal value (0.8V) (1.0V), the detection voltage Is 1.0 V, there is actually 50 g or more of the developer in the developing device C. However, when the amount of the developer is determined from the ideal curve (− ○ −), the amount of the developer is 45 g. Underestimate the amount. Thereafter, for example, when the amount of the developer in the developing device C becomes 20 g, the user is set to warn the user that "there is no developer" because there is a risk of occurrence of white spots, and the ideal curve (-O In-), the detection voltage value is obtained by adding 1.2 V to the PAF value (0.8 V) .2.
When a warning display is set in advance when the voltage becomes 0 V, if a developer amount detecting device having a characteristic indicated by a curve (-□-) of the actually measured value PA1 is used, “no developer” is displayed. When the warning is displayed, 25 g of the developer remains in the developing device C. In other words, a warning of “no developer” is displayed on the display unit 40 of the image forming apparatus main body 100, although 5 g of the developer can still be used without white spots actually occurring. If the user replaces the cartridge according to the display as it is, the developer is wasted.

(B) Conversely, the developer amount detector detects that the measured amount PA2 (-△-), that is, the PAF value is smaller than the ideal value (0.8 V) (0. 6V) In the case of having the output characteristic, the developer remaining amount is estimated to be larger than the actual amount. As a result, when the warning point of “no developer” is set in the same manner as described above, the detection voltage value of the blank image is actually 1.8 V (0.6 V (PAF value) +1.2
V = 1.8V), no warning is displayed until the detected voltage value reaches 2.0V. for that reason,
Before warning "no developer", a defective image such as a blank image is output, and in some cases, the user cannot immediately prepare for replacement of the cartridge and purchases a replacement cartridge. In the meantime, there arises a problem that the image forming apparatus becomes unusable.

Therefore, according to the present invention, as shown in FIGS. 1 to 3, the storage means 20 is disposed in the process cartridge B, and the developer remaining amount detecting means 30 is provided in the storage means 20. By storing information on the amount of the developer when the maximum amount of the developer in the image forming apparatus is detected, the output of the developer remaining amount detecting means 30 varies depending on the individual difference of the process cartridge B or the image forming apparatus main body 100. In such a case, this is corrected so that the developer remaining amount can be accurately detected.

More specifically, according to the present embodiment, (1) the storage means 20 is provided in the process cartridge B,
The detected voltage value when the capacitance detected by the developer remaining amount detecting means 30 is the maximum, that is, the minimum value (PAF value) of the detected voltage is stored in the memory 20. (2) Using the PAF value stored in the storage unit 20, the remaining voltage of the toner is calculated by using a correction table in accordance with the amount of change in the detected voltage value from the PAF value. (3) The result is displayed on the display means 40 as needed. Is performed. This makes it possible to absorb the individual differences between the cartridges and to perform more accurate residual toner detection.

First, the storage means 20 provided in the process cartridge B will be described. As shown in FIGS. 1 and 3, according to the present embodiment, the process cartridge B
Has a readable / writable memory 20 as a storage means 20 and a cartridge-side transmitting unit 21 for controlling reading / writing of information from / to this memory 20 on the upper side surface of the waste developer container 7b. When the process cartridge B is mounted on the image forming apparatus main body 100, the cartridge side transmitting section 21 and the main body control section 22 provided on the image forming apparatus main body 100 are arranged to face each other. Further, the main body control unit 22 also has a function as a transmission unit on the apparatus main body 100 side.

In this embodiment, the memory 20 stores the waste developer container 7.
b, the laser beam printer A of the present embodiment has the process cartridge B
Is inserted into the image forming apparatus main body 100 in the direction in which the waste developer container 7b side is at the top, so that the cartridge side transmitting section 21 provided adjacent to the memory 20 and the main body control on the image forming apparatus main body 100 side This is because consideration has been given to facilitate alignment of the communication means constituted by the section 22.

As the storage means 20 used in the present invention, an ordinary semiconductor electronic memory such as a combination of a nonvolatile memory, a volatile memory and a backup battery can be used without any particular limitation. In particular, in the case of a non-contact memory in which data communication between the memory 20 and the read / write IC is performed by an electromagnetic wave, the non-contact between the cartridge side transmission unit 21 and the main body control unit 22 may be performed. The possibility of contact failure due to the mounting state of the cartridge B is eliminated, and highly reliable control can be performed. In this embodiment, a non-contact type memory is used as the storage unit 20.

These two main body control units 22 and transmission units 2
1 constitutes a control means for reading and writing information in the memory 20. The capacity of the memory 20 is assumed to have a sufficient capacity to store the PAF value. When storing other information besides the PAF value, an optimum capacity can be selected as appropriate. For example, it is assumed that the memory 20 has a sufficient capacity to store a plurality of pieces of information such as a cartridge usage amount and a cartridge characteristic value. It is also possible to adopt a configuration in which

Next, the control configuration of the memory 20 in this embodiment will be described.

As shown in FIG. 3, a memory 20 and a transmission unit 21 are arranged on the process cartridge B side.
In the main body control unit 22 provided in the image forming apparatus main body 100, an arithmetic unit 24, a control unit 25, a developer remaining amount correction table 26, a main body side developer remaining amount detection unit 23, and the like are provided.

Then, as described above, the current from the developer remaining amount detecting means 30 is measured by the current measuring device 33 provided in the image forming apparatus main body 100, and the main body control unit disposed in the image forming apparatus main body 100 22.

In the main body control section 22, the output signal from the developer remaining amount detecting means 30 is converted into a voltage signal by the main body side developer amount detecting section 23, and the arithmetic section 24 operates in the memory 20 of the process cartridge B and the main body side. Based on a signal from the developer remaining amount detection unit 23, a predetermined calculation process described later is performed, and further, the control unit 25 performs collation of the data obtained by the calculation unit 24 using the developer remaining amount correction table 26. Then, the developer remaining amount detection value is appropriately corrected, and the developer remaining amount level is determined.

Further, the main body control section 22 obtains the remaining amount (%) of the developer based on the detected remaining amount of the developer, and displays the information on the display means 40 on the apparatus main body or a warning of "no developer". Is displayed.

Various information can be stored in the memory. In this embodiment, it is assumed that at least the minimum value (PAF value) of the detected voltage value is stored.

The information stored in the memory 20 is always in a state where it can be transmitted / received to / from the calculation unit 24 in the main body control unit 22. The information is calculated based on the information and the control unit 23 checks the data. Is being done.

Next, a description will be given of a method of correcting the detected remaining amount of the developer using the memory 20 provided in the process cartridge B.

In the present embodiment, the detected voltage value (PAF) is written into the memory 20 as described above. The PAF value stored in the memory 20 is constantly compared with the detected voltage value. If the detected voltage value is smaller than the previous value, the PAF value in the memory 20 is sequentially rewritten. In this way, the maximum value of the detection voltage corresponding to the maximum value of the capacitance detected by the developer remaining amount detection means 30 is always reliably stored in the memory 20 as the PAF value.

According to the present invention, the amount of change (V) of the detected voltage value X from the PAF value and the developing device C are stored in the main body control section 22 as a table for correcting the detected voltage value.
The relationship with the remaining amount of developer (g) is stored in advance in the remaining amount of developer correction table 26. Table 2 shows the developer remaining amount correction table 26 used in this embodiment.

[0075]

[Table 2] As shown in Table 2, in the present embodiment, it is assumed that a blank image may occur when the remaining amount of the developer in the developing device C becomes 20 g or less.
When the amount of change from the F value becomes 1.4 V or more, a setting is made so that a warning display of "no developer" is displayed on the display means 40 of the apparatus main body 100. Also, the amount of change from the PAF value is divided into appropriate steps between 0 and 1.4 V to correspond to the remaining amount of the developer. Further, in the present embodiment, in the developer remaining amount correction table 26, the remaining amount (g) of the developer
The developer remaining amount% for indicating what percentage of the usable developer remains when not used is associated with the developer.

Here, in this embodiment, the amount of developer charged in the process cartridge B when it is not used is 200 g, and there is a possibility of white spots when the remaining amount of development in the developing device C becomes 20 g or less. Therefore, the amount of developer that can be actually used is 18
0 g. Therefore, the remaining amount (%) of the developer is displayed based on the percentage of the developer remaining with respect to the usable amount of the developer of 180 g. Further, in the present embodiment, due to the arrangement relationship of the developer remaining amount detecting means 30, the detection voltage value by the developer amount detecting device changes when the remaining amount of the developer is about 50 g (30 g of usable developer). For this reason, the developer remaining amount is 5
The developer remaining amount display (%) larger than 0 g, that is, before the rise of the detected voltage value (decrease in capacitance) starts, is, for example, “30% or more” or “100%”. Can be displayed to notify that a sufficient number is left.

As described above, in the main body control section 22, the operation section 2
Reference numeral 4 denotes a detection voltage from the PAF value of the detection voltage value based on the detection voltage of the developer amount detection device input through the main body side developer remaining amount detection unit 23 and the PAF value stored in the memory 20 of the process cartridge B. The control unit 25 calculates the amount of change, and compares the amount of change calculated by the calculation unit 24 with a table shown in Table 22 stored in the developer remaining amount correction table 26. Value P
If the amount of change from the AF value is 0.7 V, the remaining amount of the developer is 40 g, it is determined that 15% of the developer remains when not used, and the information is displayed on the display means 40.

Next, the operation of writing the PAF value and the operation of the sequential residual detection of this embodiment will be described with reference to the flowchart of FIG. The developer remaining amount correction table used halfway is shown in Table 2. S201: The power of the image forming apparatus main body 100 is turned on. S202: The main body side developer remaining amount detection unit 23
To check whether the PAF value is stored in the memory. Case 1: When “No” is determined in S202 S203: The main body side developer remaining amount detection unit 23 measures the detected voltage value. S204: Store measured value X of detected voltage in memory 20 as PA
The value is stored as the F value, and the process proceeds to S205. Case 2: When "YES" is determined in S202 S205: The main body side developer remaining amount detection unit 23 measures the detected voltage value. S206: The control means 25 compares the PAF value stored in the memory 20 with the measured value X of the detected voltage, and
Is smaller than the PAF value stored in the memory 20, and if “Yes” is determined, the process proceeds to step S207.
To update the PAF value in the memory 20, and then to S2
Return to 05. If “No” is determined in S206, the process proceeds to S208. S208: The operation unit 24 determines that the PA stored in the memory 20
From the relationship between the F value and the measured value X of the detected voltage, the amount of change in the measured value X of the detected voltage from the PAF value is calculated. S209: The control unit 25 compares the value calculated by the calculation unit 24 in S208 with the remaining developer amount correction table 26. S210: The control unit 23 transmits a signal indicating that the remaining amount of the developer is Y% to the display unit 40 of the image forming apparatus main body 100, and displays the information on the display unit 40. S211: The control unit 23 checks whether or not the remaining amount of developer Y (%) has reached 0%,
Proceeding to 205, the above sequence is repeated, and "Ye
If s "is determined, the sequence ends.

The control according to the above-described flowchart was performed to evaluate the display of the remaining amount of the developer according to the consumption of the developer for the two process cartridges B (E1, E2) having the developer amount detecting devices having different PAF values. As shown in FIG. 6, it was possible to sequentially measure the remaining amount of the developer by absorbing the individual difference of the process cartridge B. In FIG. 6, the vertical axis represents the P of the measured value X of the detected voltage by the developer amount detecting device.
The amount of change from the AF value is shown, and the horizontal axis shows the remaining amount display Y (%) of the developer in the developing device C.

As described above, according to the present invention, the capacitance detected by the developer remaining amount detecting means in a state where there is no developer differs among the cartridges depending on the positional relationship of the developer remaining amount detecting means and the like. Even in such a case, the relationship between the remaining amount of the developer and the capacitance (detected voltage value) can be corrected based on the capacitance value (detected voltage value) detected when the developer is full. Therefore, the remaining amount of the developer can be accurately detected.

By storing information (detected voltage value in this embodiment) corresponding to the capacitance detected when the developer is full in the memory of the cartridge, the main assembly of the image forming apparatus can be used during the use of the cartridge. When the cartridge is removed from the cartridge and the cartridge is replaced, when the cartridge is used again, the information stored in the memory is read by the main body of the image forming apparatus so that the remaining amount of the developer according to the individual cartridge is obtained. And the capacitance (detection voltage value) can be corrected, and the remaining amount of the developer can always be accurately detected.

It should be noted that the relationship between the remaining amount of the developer and the detected voltage value is greatly different depending on the cartridge configuration, particularly the configuration and arrangement of the remaining developer amount detecting means. However, the present invention is not limited to those described above, and can be determined as appropriate according to the characteristics of the image forming apparatus and the cartridge that implement the present invention. In this embodiment,
The step width of the variation from the PAF value in the developer remaining amount correction table is set corresponding to about 5 g (5%) of the developer amount when the remaining amount of the developer is large. When the number became small, the step size was made finer. However, the present invention is not limited to the step widths shown in the table shown in Table 1, but is set individually in a form conforming to the embodiment. More detailed developer remaining amount display can be performed.
Further, in the above description, the difference between the detected voltage value and the PAF value is described as the difference between them, but the present invention is not limited to this.

In the above-described embodiment, the developer remaining amount correction table 26 has been described as being stored in the main body control unit 22. Alternatively, this table may be stored in the memory 20 of the process cartridge B. You may let it. By doing so, a table corresponding to the characteristics of each cartridge can be used while being held in the cartridge itself, and a more accurate sequential remaining amount measurement of the developer can be performed for various cartridges.

In the present embodiment, the remaining amount of the developer is calculated using the table. However, a configuration is used in which the measured value of the detected voltage is corrected using a predetermined weighting function using the PAF value. Is also good.

In the present embodiment, the relationship between the capacitance detected by the developer remaining amount detecting means and the detected voltage finally detected by the developer remaining amount detecting device is inversely increased. Although the case where it is set as described above, the relationship between the capacitance and the voltage varies depending on the detection circuit provided in the image forming apparatus, and even if the relationship between the capacitance and the voltage is the same decreasing function, It may be an increasing function.

The expression of the remaining amount of the developer is also represented by (g) or (%).
However, the present invention is not limited to this. For example, as another display method, various display methods may be used, such as how many remaining sheets can be output in a more advanced form. Also, the display on the display means is not limited to the method of displaying the remaining amount of the developer as a percentage as in the above embodiment. For example, a gas gauge, a bar graph, and a value display can be used. In addition, it is naturally possible to notify by a warning message or voice, or to record and output on a recording medium, and any display method may be used as long as the user can know the remaining amount of the developer. . Further, the display of the remaining amount of the developer is not limited to being performed by the display unit 40 provided in the image forming apparatus main body 100, but may be performed by the image forming apparatus main body 1
00 can also be performed by a display means such as a screen of a device such as a host computer communicably connected to the host computer.

Further, in this embodiment, the plate antenna system is used as the developer remaining amount detecting means. However, the present invention is limited to the application in a process cartridge having the developer remaining amount detecting means of this system. is not. That is,
Even when the developer in the developing device is fully filled,
Developer remaining amount detection means, developer lot, usage environment,
If there is a possibility that the detection value of the developer remaining amount detecting means may vary due to tolerances of parts of the cartridge or electronic parts of the main body of the image forming apparatus, the principle of the present invention is not particularly limited. Is applied, it is possible to accurately detect the remaining amount of the developer.

Embodiment 2 FIG. 7 shows an embodiment of a developing device C in the form of a cartridge according to another embodiment of the present invention.

The developing device C of the present embodiment includes a developing roller 5a
And a developing chamber 5A containing a developer therein for supplying the developer to the developer carrier.
And a cartridge is integrally formed by the developing frames 11 and 12 made of plastic. In other words, the developing device C of this embodiment is a unit in which the developing device components of the process cartridge B described in the first embodiment are unitized. 7 can be considered as an integrated cartridge. Therefore, all the configuration of the developing device and the configuration of the developer amount detecting device described in the first embodiment are similarly applied to the developing device C of the present embodiment. Therefore, for the description of these configurations and operations, the above description performed in Example 1 is cited.

However, in this embodiment, the memory 20 is attached to the developer container 4, and an output sheet metal 35 which is a plate antenna as a developer amount detecting means is located below the developing roller 5a in the figure. The only difference is that only one is provided on the bottom surface of the developer container 4. In the present embodiment, when the developing bias is applied to the developing roller 5a, the developing roller 5
This is configured to detect a change in capacitance between the output plate a and the output sheet metal 35 serving as a plate antenna, thereby reducing costs. Naturally, if the plate antenna (the input metal plate 31 and the output metal plate 32) described in the first embodiment is combined with the plate antenna 35 of the present embodiment, it can be used in many places according to the amount of the developer. The changing capacitance can be detected, and more accurate measurement can be performed.

As described above, according to the structure of this embodiment, the same operation and effect as those of the first embodiment can be achieved.

[0092]

As described above, according to the present invention,
The image forming apparatus, the cartridge, and the image forming system include:
A developer storage unit, a developer amount detection unit capable of sequentially outputting a signal corresponding to the developer amount in the developer storage unit, a storage unit,
(A) storing the information corresponding to the output when the remaining amount of the developer detects the maximum amount of the developer in the storage unit; b) Further, based on the information corresponding to the output when the remaining amount of the developer stored in the storage unit detects the maximum amount of the developer and the output of the remaining amount of the developer, the developer is stored. Since the amount of the developer in the unit is sequentially detected, the remaining amount of the developer in the developing device can be accurately detected, and it is possible to be notified of the amount. It is possible to eliminate image defects such as white spots due to erroneous detection of the image and waste of the developer. In addition, even when the cartridge is replaced, the information corresponding to the output when the developer remaining amount detecting unit detects the maximum amount of the developer is always stored in the storage unit of each cartridge. An accurate remaining amount of the developer can be detected and notified to the user.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a process cartridge and an image forming apparatus according to the present invention.

FIG. 2 is an enlarged sectional view of the process cartridge of FIG.

FIG. 3 is a schematic diagram illustrating a relationship between a memory of a process cartridge according to the present invention and a main body control unit of an image forming apparatus main body.

FIG. 4 is a graph showing a relationship between a detected voltage value of a developer amount detecting device configured according to the present invention and a remaining amount of the developer.

FIG. 5 is a flowchart for explaining an embodiment of a developer amount detecting operation using the storage means of the cartridge according to the present invention.

FIG. 6 is a graph for explaining the remaining developer amount display after correcting the detection voltage value of the developer amount detection device according to the present invention.

FIG. 7 is a sectional view of an embodiment of the developing device formed into a cartridge according to the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 photosensitive drum 2 charging means 3 laser scanner 4 developer storage container 5 developing means 7 cleaning means 10 fixing means 20 storage means (memory) 21 transmission unit 22 main body control unit 40 display means of image forming apparatus main body 100 image forming apparatus main body 101 Attaching means A Laser beam printer B Process cartridge C Developing device (developing unit), developing cartridge

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideki Matsumoto 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H027 DA01 DD02 DD08 DE05 EC06 ED10 EE07 EE08 EF01 HB15 2H071 BA03 BA13 DA08 2H077 AD06 AD13 AD36 AE03 BA08 BA09 DA15 DA58 DA59 DA78 DB10 DB22

Claims (18)

[Claims] An image forming apparatus including a developer storage unit, a developer amount detection unit capable of sequentially outputting a signal corresponding to the developer amount in the developer storage unit, and a storage unit; 2. The image forming apparatus according to claim 1, wherein the storage means stores information corresponding to an output when the developer remaining amount detecting means detects the maximum amount of the developer. 2. The information corresponding to an output when the remaining amount of developer stored in the storage unit detects the maximum amount of developer, an output of the remaining amount of developer detection unit, 2. The image forming apparatus according to claim 1, wherein the amount of the developer in the developer accommodating portion is sequentially detected based on the image data. 3. The developing device according to claim 1, wherein the developing amount is detected based on a change in an output of the developer remaining amount detecting means from an output when the remaining amount of the developing agent detected in the storing means detects a maximum amount of the developing agent. 3. The image forming apparatus according to claim 2, wherein the remaining amount of the agent is detected. 4. An amount of change in the output of the developer remaining amount detecting means from an output when the developer remaining amount detecting means stored in the storage means detects the maximum amount of developer, and The image forming apparatus according to claim 3, wherein the amount of the developer is detected using a table that associates the amount of the developer with the amount of the developer. 5. The image forming apparatus according to claim 4, wherein the table is stored in the storage unit. 6. A weighting function based on an output when the remaining amount of developer stored in the storage unit detects the maximum amount of developer, and an output of the remaining amount of developer detection unit. 3. The method according to claim 2, wherein the amount of the developer is detected.
Image forming apparatus. 7. The apparatus according to claim 1, wherein said developer remaining amount detecting means outputs a signal obtained by measuring a capacitance between at least two electrodes. The image forming apparatus as described in the above. 8. The apparatus according to claim 1, further comprising a display unit, wherein a signal for displaying information on the detected remaining amount of the developer is transmitted to the display unit and displayed. 8. The image forming apparatus according to any one of items 7 to 7. 9. The apparatus according to claim 1, further comprising: a communication unit that communicates with a device having a display unit, and transmitting a signal for displaying information on the detected remaining amount of the developer to the device having the display unit. 8. The image forming apparatus according to any one of items 7 to 7. 10. The image forming apparatus according to claim 1, wherein said storage unit is a nonvolatile memory, a non-contact type nonvolatile memory, or a volatile memory provided with a power supply. apparatus. 11. The cartridge further includes an electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, developing means for supplying a developer to the electrophotographic photosensitive member, and cleaning means for cleaning the electrophotographic photosensitive member. The image forming apparatus according to claim 1, further comprising at least one of the following. 12. An image forming apparatus, comprising: a developer accommodating section; a developer amount detecting section capable of sequentially outputting a signal corresponding to a developer amount in the developer accommodating section; and a storage section. In the removable cartridge, the storage means stores information corresponding to an output when the developer remaining amount detecting means detects the maximum amount of the developer. 13. An output of the developer remaining amount detecting means from an output when the developer remaining amount detecting means stored in the storing means detects a maximum amount of the developer. 13. The cartridge according to claim 12, wherein a table is stored in which a change amount of the developer and at least a developer amount are associated. 14. The device according to claim 12, wherein the developer remaining amount detecting unit outputs a signal obtained by measuring a capacitance between at least two electrodes.
3 cartridge. 15. The cartridge according to claim 1, wherein the storage unit is a nonvolatile memory, a non-contact type nonvolatile memory, or a volatile memory provided with a power supply. 16. The cartridge further includes an electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, developing means for supplying a developer to the electrophotographic photosensitive member, and cleaning means for cleaning the electrophotographic photosensitive member. The cartridge according to any one of claims 12 to 15, wherein the cartridge has at least one of the following. 17. An image forming system for forming an image on a recording medium using a cartridge detachable from an image forming apparatus, comprising: A cartridge including: a developer amount detecting unit capable of sequentially outputting a signal; and a storage unit storing information corresponding to an output when the developer remaining amount detecting unit detects the maximum amount of the developer. b) based on the information corresponding to the output when the remaining amount of developer stored in the storage unit detects the maximum amount of developer and the output of the remaining amount of developer detection unit. Control means for sequentially detecting the amount of developer in the developer container. 18. The apparatus according to claim 1, further comprising display means for displaying information on the detected amount of developer.
7 is an image forming system.