JP2002006615A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out an accurate detection of residual toner quantity regardless of the color of the toner. SOLUTION: In the device, two types of electrostatic capacity detecting voltage Vs-residual toner quantity conversion tables in concern for black and other colors (magenta, cyan and yellow) are provided and the conversion tables are selectively utilized corresponding to the black or the other colors when the electrostatic capacity detection voltage Vs detected by an electrostatic capacity detecting means 152 is converted into the residual toner quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic or electrostatic recording type image forming apparatus such as a printer or a copying machine, and a multicolor image forming apparatus.

[0002]

2. Description of the Related Art FIG. 11 shows a conventional device for detecting the remaining amount of developer in a developing cartridge mounted on a rotary unit.
This will be described below.

As shown in FIG. 11, a rotary cartridge 17 of a multi-color image forming apparatus has a developing cartridge 13 as a developing means which stores developers (toners) of yellow Y, cyan C, magenta M, and black Bk, respectively. Is detachably mounted. Developing cartridge 13 for each color
Have the same configuration, and have a developing roller 1 which is a developer carrying member for conveying toner to a photosensitive drum 9 which is an image carrying member.
4. It has a stirring rod 15 for stirring the toner, a toner storage section 16 which is a developer storage section for storing the toner, and the like.

The rotary unit 17 has a rotating shaft 1.
An antenna electrode 18 as a detection electrode is provided in 7a.

The capacitance detecting means 52 includes a reference capacitor 53, diodes 54 and 55, a constant voltage power supply 56, a reference voltage detection resistor 57, a reference voltage detection capacitor 58, diodes 59 and 60, an antenna electrode output voltage detection resistor 61, an antenna Electrode output voltage detection capacitor 62, operational amplifier 6
3 and a clamp diode 64.

[0006] In a developing bias generator 67, which is a voltage generating means of the high voltage power supply 66, a developing bias in which an AC voltage is superimposed on a DC voltage is generated. This developing bias is applied to the reference capacitor 53 and the developing roller 14 as a voltage applying unit.

The reference capacitor 53 generates an alternating current according to the reference capacitor capacitance Cr. On the other hand, an alternating current is generated in the antenna electrode 18 according to the capacitance Ct between the developing roller 14 and the antenna electrode 18.

The AC current flowing through the reference capacitor 53 is
The voltage is rectified by a resistor 57 and a capacitor 58 via a diode 54 and converted into a DC voltage Vr1. Here, the positive input of the operational amplifier 63 has a DC voltage Vr
2 (4.5 V) is input with a voltage Vr obtained by superimposing a DC voltage Vr1.

On the other hand, an alternating current flowing through the antenna electrode 18 is supplied to a resistor 61 and a capacitor 6 via a diode 59.
2, is converted into a DC voltage, and is negatively input to the operational amplifier 63.

With the above circuit configuration, the operational amplifier 6
Reference numeral 3 outputs a voltage Vs according to the difference between the capacitance Cr of the reference capacitor 53 and the capacitance Ct between the developing roller 14 and the antenna electrode 18. Here, the output voltage Vs of the operational amplifier 63 has a characteristic represented by the following equation 1.

Vs = 4.5−A × (Ct−Cr) × f × Vpp (1) where A is a predetermined constant, Ct is a capacitance between the developing roller 114 and the antenna electrode 18, and Cr is a reference capacitor. 53
, F is the AC frequency of the developing bias, and Vpp is the peak-to-peak voltage of the developing bias.

The output voltage is suppressed to be equal to or lower than the input rated voltage of the CPU 65 in the controller 1 by the diode 64 connected to the output terminal of the operational amplifier 63.

Hereinafter, Vs is referred to as a capacitance detection voltage.

FIG. 12 shows the relationship between the capacitance Ct between the developing roller 14 and the antenna electrode 18 and the capacitance detection voltage Vs.

In FIG. 1, Ce indicates that the toner is empty (Emp).
ty), the capacitance between the developing roller 14 and the antenna electrode 18 when the toner is full (Full), and Cf is the capacitance between the developing roller and the antenna electrode 18 when the toner is full.
Ce.

Since toner, which is a developer, has a higher dielectric constant than air, the more the toner is distributed between the developing roller 14 and the antenna electrode 18, the more the electrostatic capacity between the developing roller 14 and the antenna electrode 18 becomes. Ct increases, and the capacitance detection voltage Vs decreases. Thus, the remaining amount of toner can be detected by detecting the capacitance detection voltage Vs.

FIG. 13 shows an example of a conversion table for converting the capacitance detection voltage Vs into the remaining amount of toner.

In this conversion table, the detection voltage Vs
When the detection voltage Vs = 4.5 V, it is detected that the remaining toner amount is 0%, ie, empty.

Next, the remaining amount detection sequence of the conventional example will be described with reference to the flowchart of FIG.

When printing is started (S501), first, the rotary unit 17 is rotated to place a predetermined developing cartridge, for example, a Bk developing cartridge 13 at a predetermined developing position, that is, the developing roller 1 as shown in FIG.
4 rotates to a position facing the photosensitive drum 9 (S50).
2). Next, a developing bias is generated by the developing bias generator 67 (S503). When the capacitance detection voltage Vs is CP
The analog / digital conversion is performed by the analog input unit of U65, and the CPU 65 detects the detection voltage Vs (S50).
4). Based on a conversion table stored in a storage device (not shown), the detection voltage Vs is converted into a remaining toner amount (S505), and the remaining toner amount is detected (S505).
506). Then, for example, the detection result is notified to a display unit (not shown) (S50). Next, it is determined whether or not the image formation has been completed (S508).
02 and the above steps are repeated.

[0021]

However, in the above-described conventional example, only one type of conversion table for converting the detection voltage Vs into the remaining amount of toner is used for detecting the remaining amount of toner. Therefore, when the relationship between the detection voltage Vs and the remaining amount of toner is different depending on the color of the toner to be detected, or when the relationship between the detection voltage Vs and the remaining amount of toner is different due to a change in the surrounding environment, an error occurs. The remaining amount could not be detected.

Accordingly, a main object of the present invention is to provide an image forming apparatus capable of accurately detecting the remaining amount of developer without being affected by the type of developer color.

Another object of the present invention is to provide an image forming apparatus capable of accurately detecting the remaining amount of the developer without being affected by fluctuations in the surrounding environment.

[0024]

The above object is achieved by an image forming apparatus according to the present invention. In summary, the present invention provides:
Developing means having a developer accommodating section for accommodating the developer, voltage generating means for generating a voltage including at least an AC voltage component, and at least one voltage applying section to which the voltage generated by the voltage generating means is applied At least one detection electrode, capacitance detection means for detecting a capacitance between the voltage application unit and the detection electrode, and a detection result obtained by the capacitance detection means for a developer remaining in the developer accommodating unit. A conversion table for converting as an amount, the image forming apparatus having at least two of the conversion tables.

According to another aspect of the present invention, a plurality of developing means having a developer accommodating portion for accommodating a developer, a voltage generating means for generating a voltage including at least an AC voltage component, At least one voltage application unit to which the generated voltage is applied, at least one detection electrode, capacitance detection unit for detecting a capacitance between the voltage application unit and the detection electrode, and the capacitance detection And a conversion table for converting a result of detection by the means as a remaining amount of developer in the developer accommodating section. A multicolor image forming apparatus for at least two colors, wherein at least two of the conversion tables are provided. A color image forming apparatus is provided.

According to one embodiment of the present invention, the conversion table is selected according to the color of the developer whose remaining amount is detected.

According to one embodiment of each of the above inventions,
The apparatus further includes an environment detection unit, and selects the conversion table based on a detection result of the environment detection unit. The detection result of the environment detecting means includes at least temperature information. The detection result of the environment detecting means includes at least humidity information.

According to another embodiment, the apparatus further comprises a transfer bias generating means and a transfer current detecting means, and selects the conversion table based on a detection result of the transfer current detecting means.

According to another embodiment of the invention, the voltage generating means is a developing bias generating means.

According to another embodiment of the present invention, the conversion table is selected according to the initial amount of the developer for detecting the remaining amount.

According to another embodiment of the invention, the voltage applying section is a developer carrier of the developing means.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

Embodiment 1 A first embodiment of the present invention will be described with reference to FIGS. First, a color laser printer that is an image forming apparatus of the present embodiment, that is, a multicolor image forming apparatus will be described with reference to FIG.

The color laser printer 10 according to the present embodiment
Is a controller 101, a laser unit 102 for emitting laser light L, a polygon mirror 103 for horizontally scanning the laser light L, a scanner motor 104 for rotating the polygon mirror 103 at a constant speed, and Fθ for forming an image of the laser light L.
A lens 105, a photodetector 106 for detecting a BD signal indicating a horizontal scanning start point, and a reflection mirror 107 are provided. The laser light L is modulated on and off by an image signal sent from the controller 101 to the laser unit 102. .

A photosensitive drum 109 serving as an image carrier, a charger 110 for uniformly charging the photosensitive drum 109, and a cleaning device 1 for cleaning residual toner on the photosensitive drum 109
11 and a waste toner accommodating portion 112 for accommodating the cleaned residual toner, and a drum cartridge 108 that is detachably mountable to the apparatus main body, and a developer of yellow Y, cyan C, magenta M, and black Bk ( , A toner cartridge) containing a developing cartridge 113 removably mounted therein, an intermediate transfer belt 119,
And a fixing device 130.

The developing cartridges 113 for the respective colors have the same configuration, and accommodate a developing roller 114 which is a developer carrying member for transporting the toner to the photosensitive drum 109, a stirring rod 115 for stirring the toner, and a toner. It has a toner storage section 116 which is a developer storage section.

Next, an image forming operation of the color laser printer having the above configuration will be described.

The controller 101 transmits an image signal to the laser unit 102 based on the BD signal detected by the light detector 106. The laser unit 102 generates a laser beam L based on an image signal. The laser beam L is guided to the photosensitive drum 109 charged to a predetermined voltage by the charger 110 via the polygon mirror 103, the fθ lens 105, and the reflection mirror 107, and is based on the image signal on the photosensitive drum 109. An electrostatic latent image is formed.

The electrostatic latent image formed on the photosensitive drum 109 is developed by the developing roller 114 into a toner image. The toner image on the photosensitive drum 109 is transferred to the primary transfer roller 120.
Transfer belt 11 by a predetermined bias applied to
9 is primarily transferred.

After the primary transfer, the toner remaining on the photosensitive drum 109 is removed by the cleaning device 111 and stored in the waste toner storage unit 112.

When a full-color image is formed, the above operation is repeated for each of black, magenta, cyan, and yellow by rotating the rotary unit 117.
A full-color toner image is formed on the intermediate transfer belt 119.

On the other hand, the recording paper P as a recording medium accommodated in the cassette 122 is picked up by a pickup roller 123 at a predetermined timing, and is supplied by paper feed rollers 124 and 125 to the registration roller 12.
Paper is fed up to just before 6, 127, and temporarily stops. Then, at a predetermined timing, the registration roller 12
6 and 127, the toner image on the intermediate transfer belt 119 is transferred onto the recording paper P by the secondary transfer roller 128. The toner image transferred onto the recording paper P is conveyed to the fixing device 130 by the conveyance belt 129, and is fused to the recording paper P by the fixing device 130 with pressure and heat to become a permanent image.

Thereafter, the recording paper P having the permanent image is discharged to the outside of the printer 100 by the discharge rollers 131 and 132. After the secondary transfer, the toner remaining on the intermediate transfer belt 119 is removed by the cleaning device 121.

Next, the developer remaining amount detecting device of this embodiment will be described with reference to FIG.

The rotary unit 117 has its rotating shaft 11
An antenna electrode 118 serving as a detection electrode is provided in 7a.

The capacitance detecting means 152 includes a reference capacitor 153, diodes 154 and 155,
6, a reference voltage detection resistor 157, a reference voltage detection capacitor 158, diodes 159 and 160, an antenna electrode output voltage detection resistor 161, an antenna electrode output voltage detection capacitor 162, an operational amplifier 163, and a clamp diode 164.

In a developing bias generator 167 which is a voltage generating means of the high voltage power supply 166, a developing bias in which an AC voltage is superimposed on a DC voltage is generated. This developing bias is applied to the reference capacitor 153 and the developing roller 114.

The reference capacitor 153 generates an alternating current corresponding to the reference capacitor capacitance Cr. On the other hand, an alternating current is generated in the antenna electrode 118 according to the capacitance Ct between the developing roller 114 and the antenna electrode 118.

The AC current flowing through the reference capacitor 153 is rectified by the resistor 157 and the capacitor 158 via the diode 154 and is converted into a DC voltage Vr1. Here, the positive input of the operational amplifier 163 is connected to a constant voltage source 156.
A voltage Vr obtained by superimposing the DC voltage Vr1 on the DC voltage Vr2 (4.5 V) is input.

On the other hand, an alternating current flowing through the antenna electrode 118 is rectified by a resistor 161 and a capacitor 162 via a diode 159 and converted into a DC voltage, and is negatively input to an operational amplifier 163.

With the above circuit configuration, the operational amplifier 1
63 outputs a voltage Vs according to the difference between the capacitance Cr of the reference capacitor 153 and the capacitance Ct between the developing roller 114 and the antenna electrode 118. The output voltage Vs of the operational amplifier 163 has a characteristic represented by the above-described equation 1. Vs = 4.5−A × (Ct−Cr) × f × Vpp (1) where A is a predetermined constant, Ct is the capacitance between the developing roller 114 and the antenna electrode 18, and Cr is the reference capacitor 15.
3 is the capacitance, f is the AC frequency of the developing bias, Vpp
Is the peak-to-peak voltage of the developing bias. Since then
Vs is called a capacitance detection voltage.

The diode 164 connected to the output terminal of the operational amplifier 163 suppresses the output voltage below the input rated voltage of the CPU 165 in the controller 1.

The relationship between the capacitance Ct between the developing roller 114 and the antenna electrode 118 and the capacitance detection voltage Vs is as follows.
This is as shown in FIG.

As described above, in FIG. 11, Ce is the capacitance between the developing roller 114 and the antenna electrode 118 when the toner is empty (Empty), and Cf is the developing roller when the toner is full (Full). 114-antenna electrode 1
The capacitance is between 18 and Cr = Ce.

FIG. 3 shows (a) black and (b) capacitance detection voltages Vs-toner remaining amount conversion tables for magenta, cyan and yellow in this embodiment, respectively. As can be understood from FIG. 3, since the properties and the filling amount of the toner are different between black and other colors, that is, magenta, cyan, and yellow, the relationship between the electrostatic capacitance detection voltage Vs and the remaining amount of toner is different. Is different.

Here, the flow of the toner remaining amount detection operation in this embodiment will be described with reference to the flowchart of FIG.

When printing, that is, image formation is started (S
1) First, the rotary unit 117 is rotated to place a predetermined developing cartridge, for example, a Bk developing cartridge 113 in a predetermined developing position, that is, a position where the developing roller 114 is opposed to the photosensitive drum 109 as shown in FIG. (S2). Next, a developing bias is generated by the developing bias generator 167 (S3). Capacitance detection voltage V
s is converted from analog to digital by the analog input unit of the CPU 165, and the CPU 165 detects the detection voltage Vs (S4). Next, a conversion table of the corresponding color is selected from the two types of capacitance detection device-toner remaining amount conversion tables stored in the storage device (not shown) (S).
5). Based on the selected conversion table, the detection voltage Vs
Is converted to the remaining toner amount (S6), and the remaining toner amount is detected (S7). Then, for example, a detection result is notified to a display unit (not shown) (S8). Next, it is determined whether or not the image formation is completed (S9). If the image formation is to be continued, the process returns to step S2,
Repeat the above steps.

As described above, according to this embodiment, the conversion table is selected corresponding to black and other colors, and the detection voltage is converted into the remaining toner amount to detect the remaining toner amount. It is possible to accurately detect the remaining amount of toner without being affected by the color of the toner.

In the present embodiment, the description has been made using two types of conversion tables of black and other colors.
However, the number of conversion tables is not limited to two. For example, four types of conversion tables may be provided for each color.

Embodiment 2 Next, a second embodiment of the present invention will be described with reference to FIGS.

The image forming apparatus of this embodiment is similar to the image forming apparatus shown in FIGS.
5 is substantially the same as the first embodiment shown in FIG.
As shown in FIG. 7, the difference is that an environment detecting means 200 is provided.

The environment detecting means 200 detects temperature information and humidity information and converts them into electric signals. This electric signal is CP
The signal is input to the analog input unit of U165 and further converted to a digital signal. And, based on this digital signal,
Detect temperature and humidity.

The relative permittivity of the toner as a developer changes depending on the ambient temperature and humidity. Therefore, the relationship between the capacitance detection voltage Vs and the remaining amount of toner changes.

FIG. 6 shows a black capacitance detection voltage Vs-toner remaining amount conversion table in this embodiment. In this embodiment, (A) normal time, (B) high temperature / high humidity,
(C) Three conversion tables of low temperature / low humidity are provided. Table 1 below shows the temperature and humidity in each conversion table.
As shown in FIG.

[0065]

[Table 1]

Next, the operation of detecting the remaining amount of black toner in this embodiment will be described with reference to the flowchart of FIG.

When printing is started (S51), first,
By rotating the rotary unit 117, the Bk developing cartridge 113 is moved to a predetermined developing position, that is, the developing roller 1.
14 rotates to a position facing the photosensitive drum 109 (S
52). Next, the temperature and humidity are detected by the environment detecting means 200 and stored in a storage device (not shown) (S53).

Next, the developing bias is generated by the developing bias generating unit 167 (S54). Capacitance detection voltage Vs
Are converted from analog to digital by the analog input unit of the CPU 165, and the CPU 165 detects the detection voltage Vs (S
55). Based on the relationship between the detection results of the temperature and the humidity and Table 1 above, a corresponding one of three types of capacitance detection voltage Vs-toner remaining amount conversion tables stored in a storage device (not shown). A conversion table is selected (S56).
Based on the selected conversion table, the detection voltage Vs is converted into a remaining toner amount (S57), and the remaining toner amount is detected (S57).
58). Then, for example, a detection result is notified to a display unit (not shown) (S59). Next, it is determined whether or not the image formation is completed (S60). If the image formation is to be continued, the process returns to step S52, and the above steps are repeated. The detection of the remaining amount of the toner of the other colors is performed in the same manner.

As described above, according to this embodiment, a corresponding conversion table is selected from the three types of conversion tables based on the detection results of the temperature and the humidity by the environment detecting means.
Since the detection voltage Vs is converted to the remaining amount of toner, accurate detection of the remaining amount of toner can be performed without being affected by a change in the surrounding environment.

Although the present embodiment has been described using three types of conversion tables based on the detection results of temperature and humidity, the number of conversion tables is not limited to three.

Further, in the present embodiment, the case of the multi-color image forming apparatus has been described, but it goes without saying that the present embodiment can be applied to a single-color image forming apparatus.

Embodiment 3 Next, a third embodiment of the present invention will be described with reference to FIGS. The image forming apparatus of the present embodiment is substantially the same as the first embodiment described with reference to FIGS. 1 and 2, but based on the detection result of the secondary transfer current, the capacitance detection voltage Vs−the toner remaining amount The difference is that a conversion table is selected.

To further explain, the secondary transfer current detecting device (transfer current detecting means) 301 is provided from the secondary transfer bias generating device (transfer current detecting means) 300 to the secondary transfer roller 1.
The secondary transfer current flowing through the detector 28 is detected and converted into an analog voltage signal. The analog voltage signal is input to an analog input section of the CPU 165, and is further converted into a digital signal.
The CPU 165 detects a secondary transfer current based on the digital signal.

The secondary transfer current when the secondary transfer bias is constant is small when the surrounding environment is at a low temperature / low humidity.
At high temperature / high humidity, it tends to be large. Therefore,
From the detection result of the secondary transfer current, the situation of the surrounding environment can be determined.

As described in the second embodiment, the relationship between the capacitance detection voltage Vs and the remaining amount of toner differs depending on the surrounding environment. Therefore, based on the detection result of the secondary transfer current, a capacitance detection voltage Vs-toner remaining amount conversion table is selected.

FIG. 9 shows a black capacitance detection voltage Vs-toner remaining amount conversion table in this embodiment. As shown in Table 2 below, three types of conversion tables according to the secondary transfer current, namely, (D) a normal transfer current, (E) a large transfer current, and (F) an exchange table when the transfer current is small. It is.

[0077]

[Table 2]

The operation of detecting the remaining amount of black toner in this embodiment will be described with reference to the flowchart of FIG.

When printing is started (S101), first, the rotary unit 117 is rotated to rotate the Bk developing cartridge 113 to a predetermined developing position, that is, a position where the developing roller 114 is opposed to the photosensitive drum 109 (S102). ). Next, a developing bias is generated by the developing bias generator 167 (S103). The capacitance detection voltage Vs is converted from analog to digital by the analog input unit of the CPU 165, and the CPU 165 detects the detection voltage Vs (S104). Next, the secondary transfer bias generator 3
At 00, a secondary transfer bias is generated to perform secondary transfer (S105). After the secondary transfer to the recording paper P is completed, the secondary transfer bias is set to a predetermined voltage, and the secondary transfer current at that time is detected by the secondary transfer current detecting device 301 (S106). 2
From the three types of capacitance detection voltage Vs-toner remaining amount conversion tables stored in the storage device (not shown) based on the relationship between the detection result of the next transfer current and Table 2, the corresponding conversion table Is selected (S107). Based on the selected conversion table, the detection voltage Vs is converted into a remaining toner amount (S108), and the remaining toner amount is detected (S109). Then, for example, a detection result is notified to a display unit (not shown) (S
110). Next, it is determined whether or not the image formation has been completed (S
111), if continuing, return to step S102,
Repeat the above steps.

As described above, according to the present embodiment, based on the detection result of the secondary transfer current, three types of capacitance detection voltages V
From the s-toner remaining amount conversion table, a corresponding conversion table is selected, the detection voltage Vs is converted into the remaining toner amount, and the remaining toner amount is detected, so that the detection voltage Vs can be accurately determined regardless of the surrounding environment. Detection of the remaining amount of toner can be performed.

Although the present embodiment has been described using three types of conversion tables, the number of conversion tables is not limited to three.

In this embodiment, the conversion table is selected based on the value of the secondary transfer current. However, the conversion table may be selected based on the value of the primary transfer current.

Further, in the present embodiment, the case of a multi-color image forming apparatus has been described, but the present embodiment can be applied to a single-color image forming apparatus.

It should be noted that a plurality of capacitance detection voltage Vs-toner remaining amount conversion tables are stored in accordance with the initial amount of the toner, ie, the amount of the developer, which is stored in the toner storing portion of the developing cartridge. It is also possible to prepare and convert the capacitance detection voltage into the remaining amount of toner based on the corresponding conversion table to detect the remaining amount of toner.

In the above embodiment, the description has been given of the configuration in which the remaining amount of toner of all colors is detected by one capacitance detecting means. However, the number of the capacitance detecting means is not limited to one, and for example, an independent capacitance detecting means may be provided for each color.

In the above embodiment, the description has been given of the configuration using the developing bias as the oscillation source. However, the oscillation source is not limited to the developing bias, and may be, for example, an independent dedicated oscillation source.

Further, in the above embodiment, the configuration in which the remaining amount of toner is detected by one antenna electrode has been described. However, a configuration in which the remaining amount of toner is detected by a plurality of antenna electrodes may be employed.

In the above embodiment, the configuration in which the antenna electrode is arranged outside the developing cartridge has been described.
However, the antenna electrode may be arranged inside the developing cartridge.

In this embodiment, the description has been given of the configuration of the developing cartridge system. However, the toner remaining amount detecting means in the present embodiment is not limited to the image forming apparatus of the developing cartridge type, but can be applied to the image forming apparatus of the toner replenishing type.

[0090]

As is apparent from the above description, according to the present invention, in an image forming apparatus for detecting and notifying the remaining amount of the developer from the detection result of the capacitance detecting means and the conversion table, at least the conversion table is provided. By having two, it is possible to accurately detect the remaining amount of the developer without being influenced by the color of the developer or a change in the surrounding environment.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a multicolor image forming apparatus according to the present invention.

FIG. 2 is a circuit diagram showing an embodiment of a capacitance detecting means according to the present invention.

FIG. 3 is a diagram showing an embodiment of a capacitance detection voltage-toner remaining amount conversion table (a: black, b: magenta, cyan, yellow) according to the present invention.

FIG. 4 is a flowchart showing one embodiment of a toner remaining amount detecting operation according to the present invention.

FIG. 5 is a circuit diagram showing another embodiment of the capacitance detecting means according to the present invention.

FIG. 6 is another table for converting a capacitance detection voltage-toner remaining amount according to the present invention (A: black, normal time, B: black, high temperature / high humidity, C: black, low temperature / low humidity) It is a figure showing an example.

FIG. 7 is a flowchart showing another embodiment of the toner remaining amount detecting operation according to the present invention.

FIG. 8 is a circuit diagram showing another embodiment of the capacitance detecting means according to the present invention.

FIG. 9 shows another embodiment of a capacitance detection voltage-toner remaining amount conversion table (D: black, normal transfer current, E: black, large transfer current, F: black, small transfer current) according to the present invention. FIG.

FIG. 10 is a flowchart showing another embodiment of the toner remaining amount detecting operation according to the present invention.

FIG. 11 is a circuit diagram showing an example of a conventional capacitance detecting means.

FIG. 12 is a graph showing the relationship between the remaining amount of toner and the capacitance detection voltage Vs.

FIG. 13 is a diagram illustrating an example of a conventional capacitance detection voltage-toner remaining amount change table.

FIG. 14 is a flowchart illustrating an example of a conventional toner remaining amount detection operation.

[Explanation of symbols]

113 Developing cartridge (developing unit) 114 Developing roller (voltage applying unit) 116 Toner accommodating unit (developer accommodating unit) 118 Antenna electrode (detecting electrode) 152 Capacitance detecting unit 166 High voltage power supply 167 Developing bias generator (voltage generating unit) 200 environment detecting means 300 secondary transfer bias generator (transfer bias generating means) 301 secondary transfer current detecting apparatus (transfer current detecting means)

Claims (19)

[Claims] 1. A developing means having a developer accommodating portion for accommodating a developer, a voltage generating means for generating a voltage including at least an AC voltage component, and at least one voltage to which a voltage generated by the voltage generating means is applied. One voltage application unit, at least one detection electrode, capacitance detection means for detecting a capacitance between the voltage application unit and the detection electrode, and a developer accommodating the detection result by the capacitance detection means. And a conversion table for converting the remaining amount of the developer into the remaining amount of the developer, wherein at least two conversion tables are provided. 2. The image forming apparatus according to claim 1, further comprising an environment detection unit, wherein the conversion table is selected based on a detection result of the environment detection unit. 3. The image forming apparatus according to claim 2, wherein the detection result of said environment detecting means includes at least temperature information. 4. The image forming apparatus according to claim 2, wherein the detection result of said environment detecting means includes at least humidity information. 5. The apparatus according to claim 1, further comprising a transfer bias generating unit and a transfer current detecting unit, wherein the conversion table is selected based on a detection result of the transfer current detecting unit. Any one of the image forming apparatuses. 6. An image forming apparatus according to claim 1, wherein said voltage generating means is a developing bias generating means. 7. The image forming apparatus according to claim 1, wherein the conversion table is selected according to an initial filling amount of the developer whose remaining amount is detected. 8. The image forming apparatus according to claim 1, wherein the voltage applying unit is a developer carrier of the developing unit. 9. A plurality of developing means having a developer accommodating portion for accommodating a developer, a voltage generating means for generating a voltage including at least an AC voltage component, and a voltage generated by the voltage generating means is applied. At least one pressure applying means,
At least one detection electrode, a capacitance detection unit that detects a capacitance between the voltage application unit and the detection electrode,
A multi-color image forming apparatus for at least two colors, comprising: a conversion table for converting a result of detection by the capacitance detecting means as a remaining amount of developer in the developer accommodating section. And a multicolor image forming apparatus. 10. The developer of which remaining amount is detected,
10. The conversion table is selected.
Multicolor image forming apparatus. 11. The multicolor image forming apparatus according to claim 9, further comprising an environment detecting unit, wherein the conversion table is selected based on a detection result of the environment detecting unit. 12. The detection result of the environment detecting means includes at least temperature information.
1. A multicolor image forming apparatus. 13. The detection result of the environment detecting means includes at least humidity information.
1. A multicolor image forming apparatus. 14. The apparatus according to claim 9, further comprising a transfer bias generating unit and a transfer current detecting unit, wherein the conversion table is selected based on a detection result of the transfer current detecting unit. Any one of the multi-color image forming apparatuses. 15. The multicolor image forming apparatus according to claim 14, wherein the detection result of the transfer current detecting means includes at least current information of primary transfer. 16. The multicolor image forming apparatus according to claim 14, wherein the detection result of said current detecting means includes at least current information of secondary transfer. 17. The multicolor image forming apparatus according to claim 9, wherein said voltage generating means is a developing bias generating means. 18. The multi-color image forming apparatus according to claim 9, wherein said conversion table is selected according to an initial filling amount of the developer whose remaining amount is detected. 19. The multicolor image forming apparatus according to claim 9, wherein said voltage applying section is a developer carrier of said developing means.