JPH11272062A - Developing device and image forming device - Google Patents

Abstract

(57) [Problem] To provide a developing device having a toner sensor capable of accurately and stably detecting a toner concentration in a developer with an output signal. SOLUTION: A storage section for storing a developer comprising a toner and a carrier, a first transfer means disposed in the storage section, and for transferring the developer in a first direction; Disposed below the first conveying means, for conveying the developer in a second direction opposite to the first direction,
A second transport unit for circulating and transporting the developer in the storage unit together with the first transport unit; and a detection unit for detecting a toner concentration of the developer stored in the storage unit; The detection means is arranged on the bottom surface of the storage part in the vicinity of a supply part which is lifted and supplied from the transportation means to the first transportation means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device and an image forming apparatus, and more particularly to a developing device having a toner sensor at a position where a stable signal can be output.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying machine, an electrostatic latent image formed on the surface of a photosensitive drum is developed by a developing machine using a developer to form a developer image. The developer image is transferred to transfer paper by a transfer device. As a developing method used for such an image forming apparatus, there is a two-component developing method using a toner and a carrier as a developer.

In this two-component developing system, only the toner in the developer is consumed by supplying the developer to the photosensitive drum by a developing machine and performing the development. As a result, the mixing ratio of the toner and the carrier changes, and it is necessary to supply the toner to the developing device.

However, when the toner concentration in the developer is reduced, the image density is reduced. On the other hand, when the toner concentration is increased, the toner is contaminated due to a decrease in the charge amount of the toner. Must be maintained.
For that purpose, it is necessary to accurately detect the toner concentration in the developer, and a toner sensor is attached to the developing machine,
2. Description of the Related Art Accurate detection of the toner concentration in a developer has been performed.

[0005]

As described above, the developing device is provided with the toner sensor for detecting the toner concentration in the developer, but it is difficult to select the mounting position, which is a serious problem. ing. For example, when a sensor is mounted on the side surface of the developing machine, the sensor output is small, the behavior of the developer is not stable, and the output value greatly changes with the inclination of the developing machine.

That is, the position where the toner concentration in the developer can be accurately detected, the position where the toner sensor can output a stable signal, and the position where the circulation of the developer is not hindered do not always coincide with each other, and are satisfied simultaneously. It is desired to appropriately select the mounting position of the toner sensor.

The present invention has been made under such circumstances, and includes a toner sensor capable of accurately detecting the toner concentration in a developer with a stable output signal without hindering the circulation of the developer. An object is to provide a developing device.

Another object of the present invention is to provide an image forming apparatus having a toner sensor capable of detecting the toner concentration in a developer accurately and with a stable output signal without hindering the circulation of the developer. Is to provide.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a storage portion for storing a developer including toner and a carrier, and a developer disposed in the storage portion, wherein the developer is moved in a first direction. A first transporting unit that transports the developer in the storage unit, and is disposed below the first transporting unit, and transports the developer in a second direction opposite to the first direction;
A second transport unit for circulating and transporting the developer in the storage unit together with the first transport unit; and a detection unit for detecting a toner concentration of the developer stored in the storage unit; A developing device is provided, wherein the detecting means is disposed on a bottom surface of the storage section in the vicinity of a supply section which is lifted and supplied from the transport means to the first transport means.

According to the present invention, there is provided an accommodating portion for accommodating a developer comprising a toner and a carrier, a first conveying means disposed in the accommodating portion for conveying the developer in a first direction, Wherein the developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates the developer in the storage unit together with the first transport unit. A second conveying means for conveying, and a developer disposed at an end of the second conveying means, wherein the developer conveyed in the second direction does not reach the side surface of the storage portion and is opposite to the second direction. A return unit for returning to the original direction, and a detection unit for detecting a toner concentration of the developer stored in the storage unit, wherein the detection unit is configured to transfer the toner concentration from the second transport unit to the first transport unit. In the vicinity of the supply unit for lifting and supplying, Between the said and the means to second conveying means, to provide a developing device, characterized in that arranged in the housing part bottom face.

According to the present invention, there is provided an accommodating portion for accommodating a developer comprising a toner and a carrier, a first conveying means disposed in the accommodating portion, for conveying the developer in a first direction, Wherein the developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates the developer in the storage unit together with the first transport unit. A second conveying unit that conveys the toner, and a detecting unit that detects a toner concentration of the developer stored in the storage unit, wherein the detecting unit is configured to transfer the toner concentration from the second conveying unit to the first conveying unit. A developing device is provided which is provided at a discharge port for discharging the developer in the storage section in the vicinity of a supply section to be lifted and supplied.

According to the present invention, there is provided an accommodating portion for accommodating a developer comprising a toner and a carrier, a first conveying means arranged in the accommodating portion, for conveying the developer in a first direction, Wherein the developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates the developer in the storage unit together with the first transport unit. A second conveying unit that conveys the toner, and a detecting unit that detects a toner concentration of the developer stored in the storage unit, wherein the detecting unit is configured to transfer the toner concentration from the second conveying unit to the first conveying unit. A developing device is provided which is provided in a movable opening / closing means for opening and closing a discharge port for discharging the developer in the storage section, in the vicinity of a supply section to be lifted and supplied.

According to the present invention, there is provided an accommodating portion for accommodating a developer comprising a toner and a carrier, a first conveying means disposed in the accommodating portion for conveying the developer in a first direction, Wherein the developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates the developer in the storage unit together with the first transport unit. A second conveying means for conveying, and a developer disposed at an end of the second conveying means, wherein the developer conveyed in the second direction does not reach the side surface of the storage portion and is opposite to the second direction. Return means for returning to the direction, a discharge port provided below the return means for discharging the developer in the storage section, and detection for detecting the toner concentration of the developer stored in the storage section. Means, wherein the detecting means comprises: It is arranged near the supply unit which is lifted from the feeding means to the first transport means and is supplied, and is disposed on the bottom of the housing part between the return means and the second transport means. A developing device is provided.

According to the present invention, there is provided an image carrier, a developing means for developing an electrostatic latent image on the image carrier using a developer comprising toner and a carrier, and a method for developing the developed developer image on a transfer material. An image forming apparatus comprising:
The developing unit includes a storage unit that stores the developer, a first transport unit that is disposed in the storage unit, and that transports the developer in a first direction.
A second direction, which is disposed below the transporting means, transports the developer in a second direction opposite to the first direction, and circulates and transports the developer in the storage section together with the first transporting means. Transport means, and a detecting means for detecting the toner concentration of the developer stored in the storage section, in the vicinity of a supply section to lift and supply from the second transport means to the first transport means, An image forming apparatus is provided, wherein the detection unit is disposed on a bottom surface of the storage unit.

According to the present invention, there is provided an image carrier, developing means for developing an electrostatic latent image on the image carrier using a developer comprising a toner and a carrier, and a method for developing the developed developer image on a transfer material. An image forming apparatus comprising:
The developing unit includes a storage unit that stores a developer including a toner and a carrier, a first transport unit that is disposed in the storage unit, and that transports the developer in a first direction. Disposed below the first transport means,
A second transport unit that transports the developer in a second direction opposite to the first direction and circulates and transports the developer in the storage unit together with the first transport unit; and stores the developer in the storage unit. Detecting means for detecting the toner concentration of the developer, wherein the detecting means is provided in the housing section in the vicinity of a supply section which lifts and supplies the second developer from the second transporter to the first transporter. An image forming apparatus is provided at a discharge port for discharging a developer.

According to the present invention, there is provided an image carrier, a developing means for developing an electrostatic latent image on the image carrier using a developer comprising toner and a carrier, and a method for developing the developed developer image on a transfer material. An image forming apparatus comprising:
The developing unit includes a storage unit that stores a developer including a toner and a carrier, a first transport unit that is disposed in the storage unit, and that transports the developer in a first direction. Disposed below the first transport means,
A second transport unit that transports the developer in a second direction opposite to the first direction, and circulates and transports the developer in the storage section together with the first transport unit; and the second transport The developer conveyed in the second direction does not reach the side of the housing portion, and
Return means for returning the toner in the opposite direction to the direction of, a discharge port provided below the return means for discharging the developer in the storage section, and a toner concentration of the developer stored in the storage section. Detecting means for detecting the position of the second conveying means, wherein the detecting means is located near a supply unit which lifts and supplies the second conveying means from the second conveying means to the first conveying means. And an image forming apparatus, wherein the image forming apparatus is disposed on a bottom surface of the housing section between the image forming apparatus and the image forming apparatus.

In the developing device and the image forming apparatus of the present invention configured as described above, the toner sensor is provided at the bottom of the developer push-up unit, which is the optimum position for detecting the toner density. . This position is a position where there is a stable amount of developer and there is little effect even if the apparatus is inclined.

Therefore, the sensor output is large, the behavior of the developer is stable, and the change in the output value with respect to the inclination of the developing machine is small, so that the toner concentration can be accurately and stably detected. . Further, by providing the developer discharge port at the same position, the automatic discharge of the developer can be performed without any trouble.

[0019]

Embodiments of the present invention will be described below. 1 shows a developing machine according to an embodiment of the present invention and a flow of a developer in the developing machine. FIG. 2 is a sectional view taken along line AA of FIG. 1 and FIG. 3 is a sectional view taken along line BB of FIG. is there.

As shown in FIGS. 1 to 3, a developing machine includes a developing sleeve 1 which carries a two-component developer composed of a non-magnetic toner and a magnetic carrier and conveys it as a magnetic brush in a circumferential direction, and an arbitrary magnetic pole pattern. And a permanent magnet 2 fixedly arranged in the developing sleeve 1 and upper and lower developer conveying paths 6.
And upper and lower mixers 4 and 7 for stirring and transporting the developer, and upper and lower developer transport paths 6 and 7, respectively.
And a partition wall 5 for partitioning the partition wall.

In the developing device having such a configuration, the developer is supplied to the developing sleeve 1 in the upper transport path 6 while being transported by the upper mixer 3. The developer supplied to the developing sleeve 1 is separated from the developing sleeve 1 between the N3 and N2 poles, and is collected in the lower transport path 7. This flow of the developer is represented by Q1 in the figure.

In the vicinity of both ends of the upper and lower partition plates 5, holes 8 for dropping the developer conveyed by the upper mixer 3 to the front side of the upper conveying path 6 into the lower conveying path 7 (flow Q2 in the figure). And a hole 9 through which the developer conveyed to the rear side of the lower conveying path 7 by the lower mixer 4 is pushed up and moved to the upper conveying path 6 (flow Q3 in the drawing).

FIG. 3 shows a cross section (BB cross section) of the portion where the developer is pushed up. Note that, in the drawing, arrows indicate the rotation directions of the upper mixer 3 and the lower mixer 4, respectively. At the rear end of the lower mixer 4, a return mixer 10 is provided so that the developer conveyed to the rear side by the lower mixer 4 returns without hitting the developing case wall. Usually, the developer flows upward in the region between the lower mixer 4 and the return mixer 10.

Such a flow of the developer is represented by Q3 = Q1 +
It is circulating in the developing machine while maintaining the balance of Q2. After the replenishment toner is sufficiently stirred, the developing sleeve 1
So that the toner supply position 11 is
It is provided on the front side.

The inventor of the present invention has made various studies on the proper position for installing the toner sensor in the developing machine described above as follows. First, as for the flow of the developer in the developing machine, only the developer not consumed by the developing sleeve 1 flows on the front side (the right side in FIG. 1) of the developing machine. The developer supplied to the developing sleeve 1 and consumed is transferred to the lower transport path 7.
And is conveyed to the rear side by the lower mixer 4. Therefore, the toner sensor 12 for detecting the toner density
Is desirably attached to the rear side.

From the experience of the related art, in order to stably detect the sensor, it is necessary to attach the developing agent to a portion where the amount of the developer is more stably carried than the portion where the developer is conveyed by the mixer.

From these facts, it can be said that it is desirable to attach the developer to a location where the developer is brought up by the lower mixer 4 and the reverse mixer 9 and pushed upward. Next, among the three locations 13a, 13b, and 13c in FIG. 3, a location where the toner density can be detected most stably was examined. That is, the toner sensors 12 are sequentially installed at three locations 13a, 13b and 13c, the developer is circulated in the developing machine, and the toner density is detected by the toner sensors 12. 4
The output waveform shown in FIG. FIG. 4A shows a position 13a,
(B) shows the output waveform at the position 13b, and (c) shows the output waveform at the position 13c.

FIG. 4 shows that the output waveform at the position 13c is the most stable, and the output waveform at the position 13a fluctuates greatly. Next, a tilt test of the developing machine was performed. That is, the toner sensors 12 were installed at three locations 13a, 13b, and 13c in FIG. 3, the developing machine was inclined, and sensor output values at various inclination angles were measured.
The result is shown in FIG.

From the results shown in FIG. 4 and FIG.
When a sensor is mounted on the side a (upper conveyance path side), the sensor output is small, and the behavior of the developer is not stable, so that a large ripple is caused. Further, the output value greatly changes with the inclination of the developing machine. You can see that.

On the other hand, in the case of the mounting positions 13b (the lower transport path side) and 13c (the lower transport path bottom), there is no large difference in the sensor output, and the output waveform when the developer is circulating, and The output value for the slope is stable. However, it can be seen from the sensor output waveform shown in FIG. 4 that the waveform at the sensor mounting position 13c is more stable than that at 13b.

From the above results, the optimum sensor mounting position in the developing machine according to the present embodiment is “the bottom of the portion where the developer is pushed up in the rear lower conveying path: position 13
c ".

When the developer is replaced due to the life of the developer, the developer is required to be disassembled and cleaned because the developer circulation of the developer and the structure of the developer are complicated. However, since it is generally difficult for a general user to disassemble the developing machine, it is desirable to automatically discharge the developer from the developing machine. The location of the developer outlet for this purpose is preferably a location where the developer gathers when the developer is circulating in the developing machine.

When the circulation of the developer in the developing machine according to this embodiment is examined, the developer always collects on the rear side (region A: in particular, where the developer is concentrated by the lower mixer 4 and the reverse mixer 10). I understood. However, the area A is also an optimal sensor mounting position where the toner sensor can output a stable signal. Therefore, in order to obtain a stable sensor output and to enable automatic discharge, the sensor mounting position and the automatic discharge position overlap.

Here, the structure of the developer push-up section on the rear side of the developing machine will be described with reference to two examples. In the first example, as shown in FIG. 6, the developer outlet is located in the rear area A.
(A location where the developer is concentrated between the lower mixer 4 and the return mixer 10: developer push-up section). Normally, the shutter 14 is closed, and the developer circulates normally.
Since the toner sensor 12 is attached to the shutter 14 and is located in the area A, a stable sensor output can be obtained while the developer circulates normally.

At the time of automatic discharge, the shutter 14 is opened by a mechanism (not shown), the developer is automatically discharged from the developer discharge port, and is collected in the discharged developer receiver 15. In the second example, as shown in FIG. 7, the toner sensor 12 is provided in the rear area A (where the developer concentrates between the lower mixer 4 and the return mixer 10: developer push-up section). ing.
The developer outlet is provided at the bottom of the apparatus below the return mixer 10 at a position shifted from the area A.

The shutter 14 is normally closed, and the developer circulates normally. In this example, the return mixer 10
The problem is whether or not the developer can be automatically and efficiently discharged from a developer discharge port provided at the bottom of the apparatus below.

FIG. 8 is a graph showing the discharge amount of the developer with respect to the discharge time when the developer is circulated in the developing machine after opening the shutter 14 of the developer discharge port in the example shown in FIG. . In the developing machine, 400 g of the developer is initially supplied. It can be seen from the graph of FIG. 8 that about 90% of the developer can be discharged after about 50 seconds. This is a result that hardly differs from the example shown in FIG.

The remaining 10% of the developer remains between the developing machine case and the mixer and in the vicinity of the peeling pole of the developing sleeve. After the automatic discharge is completed, the residual developer can be discharged by taking out the developing device and slightly tilting the developing device.

Incidentally, also in the second example, at the time of automatic discharge, the shutter 14 is opened by a mechanism (not shown), the developer is automatically discharged from the developer discharge port, and is collected in the discharged developer receiver 15.

Next, an example in which the developing device of the present invention is applied to a color PPC will be described with reference to FIG. In FIG. 9, a sheet feeding device 105 on which sheets P are stacked is provided on one side of the apparatus main body 101.
5 feeds the paper P one by one into the apparatus main body 101.

A sheet P sent from the sheet feeding device 105 into the apparatus main body 101 receives a pair of aligning rollers 105.
Are once stopped and aligned. Further, the rotation of the aligning roller 104 causes the roller to be inserted onto the transfer belt 121.

The transfer belt 121 is made of a material that is stable in terms of both heat and abrasion resistance, for example, semiconductive polyimide, and is mounted between the driving roller 120 and the driven roller 122. The driven roller 122
The transfer belt 121 runs without slack.

Above the transfer belt 121, process units 102Y, 102M, 102C, and 102B are provided. Each process unit 102Y, 1
Reference numerals 02M, 102C, and 102B denote a yellow (yellow) process unit 102Y, a magenta (red-purple) process unit 102M, a cyan (blue-green) process unit 102C, and a black (black) process unit 102B according to the color of the toner. It has become.

Each of the process units 102Y, 102M,
102C and 102B are photosensitive drums 106Y and 106
M, 106C and 106B. Around each photoconductor drum 106Y, 106M, 106C, 106B,
Charging devices 109Y, 109M, 109C, 109 for uniformly charging the surface of the photosensitive drum sequentially along the rotation direction.
B, developing devices 107Y, 107M, 107C, and 107B for developing images formed on the respective photosensitive drums, and transfer devices 108Y, 108M, 108C, and 108B for transferring the developed images formed on the photosensitive drums to paper P Cleaning devices 110Y and 110 for removing residual toner
M, 110C, 110B, and a static eliminator (not shown) that uniformly irradiates the residual potential remaining on the photosensitive drum after the toner is removed by the cleaning device to eliminate static electricity are provided.

Each process unit 102
For Y, 102M, 102C, and 102B, laser beam optical devices 115Y, 115M, 115C, and 115B
Is arranged. Inside the transfer belt 121, the photosensitive drums 106Y, 106M,
107C, 106B, the transfer devices 108Y,
108M, 108C and 108B are provided.

A fixing device 150 is disposed on the transfer end side of the transfer belt 121. The fixing device 150 includes a fixing roller 151 having a built-in fixing roller lamp 152 and a pressure roller lamp 154.
1 and a pressure roller 152 which is in rolling contact.

On the paper transport side of the fixing device 150, a pair of paper discharge rollers 170 is disposed.
The paper is discharged to a discharge tray (not shown) attached to one side.

The paper P supplied from the paper supply device 105 is
While being sent by the aligning roller 104,
The process units 102Y, 102M, 102C,
At 102B, each image is formed.

At this time, the transfer devices 108Y, 108
M, 108C and 108B cause electric charge to be transferred to the transfer belt 121.
, The sheet P is stuck to the transfer belt 121 by the electric charge.

Hereinafter, a case will be described in which the process unit 102Y has a yellow (yellow) toner color. The surface of the photoreceptor drum 106Y is uniformly charged to about -700 V with a negative charge, for example, by the charging device 109Y. Next, a laser beam is emitted from the laser beam optical device 115Y to the photosensitive drum 106Y in accordance with the image signal.

Since the resistance of the photosensitive drum 106Y is reduced only at the portion irradiated with the light, the negative charge at the portion irradiated with the laser beam is erased, and an electrostatic latent image is formed. A semiconductor laser is usually used as a laser, and light modulated according to an image is scanned by a rotating polygon mirror (not shown).

The electrostatic latent image thus formed is developed by the developing device 107Y. That is, the toner, which is a colored fine particle negatively charged by the reversal development, is applied to the portion of the electrostatic latent image on the photosensitive drum 106Y where the negative charge has been erased by applying a developing bias of about -500 V, and the toner is statically charged. The latent image is visualized.

The sheet P is carried between the photosensitive drum 106Y and the transfer belt 121, and is transferred onto the sheet P by the transfer device 108Y. In the transfer device 108Y, for example, the plus one
An electric charge of about 000 V is applied, whereby the image developed by the negatively charged toner on the photosensitive drum 106Y is attracted to the paper P and transferred.

Similarly, magenta, cyan, and black images are sequentially processed in the process units 102M, 102C, and 10M.
2B and laser beam optical devices 115M, 115C, 11
5B and the transfer devices 108M, 108C, 108B are formed on the paper P in a multiplex manner.

The paper P is guided between the fixing roller 151 heated by the fixing roller lamp 152 and the pressure roller 152 heated by the pressure roller lamp 154, and heated between the fixing roller 151 and the pressure roller 153. The paper is fixed on the paper P by being pressed, and the printing is completed.

Thereafter, the paper P is transferred to a pair of discharge rollers 17.
0 causes the sheet to be discharged to a sheet discharge tray outside the apparatus main body 101. Each of the photosensitive drums 106Y, 106M, 106
The toner remaining on the paper P without being transferred onto the paper P exists on C and 106B. These residual toners are scraped off by the cleaning devices 110Y, 110M, 110C, and 110B, so that the photosensitive drums 106Y, 106M, and 10B.
6C and 106B are cleaned.

The color PPC developing machine 107 described above.
Y, 107M, 107C and 107B are all shown in FIGS.
It has a structure as shown in FIG. 3. For example, a developer discharge port is provided at a position as shown in FIG. 6, and a toner sensor is attached to a shutter disposed there.

Such a color PPC developing machine 107
In Y, 107M, 107C, and 107B, a stable sensor output was obtained while the developer circulated normally, and an accurate toner density could be detected.

[0059]

As described above, according to the present invention,
In a developing device in which mixing means are arranged vertically and in which complicated developer circulation is performed, a stable signal from the toner sensor can be obtained by attaching the toner sensor to a predetermined position. Further, by providing the developer discharge port at a predetermined position, automatic discharge of the developer can be performed without any trouble.

[Brief description of the drawings]

FIG. 1 is a diagram showing circulation of a developer in a developing machine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a characteristic diagram showing a comparison between sensor waveforms depending on a sensor mounting position.

FIG. 5 is a characteristic diagram showing a sensor output with respect to an inclination angle of the developing device.

FIG. 6 is a diagram illustrating a first example of a mounting position of a toner sensor.

FIG. 7 is a diagram illustrating a first example of a mounting position of a toner sensor.

FIG. 8 is a characteristic diagram illustrating a developer discharge amount with respect to a discharge time.

FIG. 9 is a view showing a color PPC provided with the developing device of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 developing sleeve 2 fixed permanent magnet 3 upper mixer 4 lower mixer 5 partition wall 6 upper transport path 7 lower transport path 8, 9 hole 10 return mixer 11 toner supply position 12 toner Sensors 13a, 13b, 13c Toner sensor mounting position 14 Shutter 15 Discharged developer receiver 101 Device main body 102Y, 102M, 102C, 102B Process unit 103 Feeding roller 104 Aligning roller 105 Feeding device 106Y , 106M, 106C, 106B: Photoconductor drums 107Y, 107M, 107C, 107B: Developing devices 108Y, 108M, 108C, 108B: Transfer devices 109Y, 109M, 109C, 109B: Charging devices 110Y, 110M, 110C, 110B: Cleaning devices 115Y, 115M, 15C, 115B ... laser beam optical system 120 ... driving roller 121 ... transfer belt 122 ... driven roller

Claims (8)

[Claims] An accommodating section for accommodating a developer comprising a toner and a carrier; a first conveying means arranged in the accommodating section for conveying the developer in a first direction; The developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates and transports the developer in the storage unit together with the first transport unit. A second conveyance unit; and a detection unit configured to detect a toner concentration of the developer stored in the storage unit, wherein the detection unit lifts the second conveyance unit to the first conveyance unit. In the vicinity of the supply unit that supplies
A developing device, wherein the developing device is disposed on a bottom surface of the housing portion. An accommodating section for accommodating a developer comprising a toner and a carrier; a first conveying means arranged in the accommodating section for conveying the developer in a first direction; The developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates and transports the developer in the storage unit together with the first transport unit. A second transporting means, a developer disposed at an end of the second transporting means, wherein the developer transported in the second direction does not reach the side surface of the storage unit, and is in a direction opposite to the second direction. Returning means for returning the toner, and detecting means for detecting the toner concentration of the developer contained in the containing section, wherein the detecting means lifts the second carrying means to the first carrying means. In the vicinity of the supply unit for supplying
The developing device according to claim 1, wherein the developing device is disposed on a bottom surface of the housing portion between the return unit and the second transport unit. 3. A storage section for storing a developer comprising a toner and a carrier, a first transporting means disposed in the storage section and transporting the developer in a first direction; The developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates and transports the developer in the storage unit together with the first transport unit. A second conveyance unit; and a detection unit configured to detect a toner concentration of the developer stored in the storage unit, wherein the detection unit lifts the second conveyance unit to the first conveyance unit. In the vicinity of the supply unit that supplies
A developing device is provided at a discharge port for discharging the developer in the storage section. An accommodating section for accommodating a developer comprising a toner and a carrier; a first conveying means arranged in the accommodating section for conveying the developer in a first direction; The developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates and transports the developer in the storage unit together with the first transport unit. A second conveyance unit; and a detection unit configured to detect a toner concentration of the developer stored in the storage unit, wherein the detection unit lifts the second conveyance unit to the first conveyance unit. In the vicinity of the supply unit that supplies
A developing device is provided in movable opening / closing means for opening / closing a discharge port for discharging the developer in the storage section. 5. An accommodation section for accommodating a developer comprising a toner and a carrier; a first conveyance means arranged in the accommodation section for conveying the developer in a first direction; The developer is disposed below the first transport unit, transports the developer in a second direction opposite to the first direction, and circulates and transports the developer in the storage unit together with the first transport unit. A second transporting means, a developer disposed at an end of the second transporting means, wherein the developer transported in the second direction does not reach the side surface of the storage unit, and is in a direction opposite to the second direction. Return means for returning, a discharge port provided below the return means for discharging the developer in the storage section, and a detection means for detecting the toner concentration of the developer stored in the storage section And the detection unit is configured to perform the second conveyance. A vicinity of the supply unit for supplying lifted from stage to said first conveying means,
The developing device according to claim 1, wherein the developing device is disposed on a bottom surface of the housing portion between the return unit and the second transport unit. 6. An image carrier, developing means for developing an electrostatic latent image on the image carrier using a developer comprising toner and a carrier, and transferring the developed developer image onto a transfer material An image forming apparatus comprising: a transfer unit configured to transfer the developer in a first direction; a storage unit configured to store the developer; and a developing unit configured to transport the developer in a first direction. Transport means, and the first
A second direction, which is disposed below the transporting means, transports the developer in a second direction opposite to the first direction, and circulates and transports the developer in the housing together with the first transporting means. Transport means, and a detecting means for detecting the toner concentration of the developer stored in the storage section, in the vicinity of a supply section to lift and supply from the second transport means to the first transport means, An image forming apparatus, wherein the detection unit is disposed on a bottom surface of the storage unit. 7. An image carrier, developing means for developing an electrostatic latent image on the image carrier using a developer comprising toner and a carrier, and transferring the developed developer image onto a transfer material An image forming apparatus comprising: a transfer unit that stores a developer including a toner and a carrier; and a developing unit that is disposed in the storage unit and moves the developer in a first direction. A first transporting means for transporting, and the first transporting means is disposed below the first transporting means in the storage section;
A second transport unit that transports the developer in a second direction opposite to the first direction and circulates and transports the developer in the storage unit together with the first transport unit; and stores the developer in the storage unit. Detecting means for detecting the toner concentration of the developer, wherein the detecting means is provided in the housing section in the vicinity of a supply section which lifts and supplies the second developer from the second transporter to the first transporter. An image forming apparatus provided at a discharge port for discharging a developer. 8. An image carrier, developing means for developing an electrostatic latent image on the image carrier using a developer comprising toner and a carrier, and transferring the developed developer image onto a transfer material An image forming apparatus comprising: a transfer unit that stores a developer including a toner and a carrier; and a developing unit that is disposed in the storage unit and moves the developer in a first direction. A first transporting means for transporting, and the first transporting means is disposed below the first transporting means in the storage section;
A second transport unit that transports the developer in a second direction opposite to the first direction and circulates and transports the developer in the storage unit together with the first transport unit; and the second transport The developer conveyed in the second direction does not reach the side of the housing portion, and
Return means for returning the toner in the opposite direction to the direction of, a discharge port provided below the return means for discharging the developer in the storage section, and a toner concentration of the developer stored in the storage section. Detecting means for detecting the position of the second conveying means, wherein the detecting means is located near a supply unit which lifts and supplies the second conveying means from the second conveying means to the first conveying means. An image forming apparatus, wherein the image forming apparatus is disposed on a bottom surface of the housing section between the image forming apparatus and the unit.