JPH1063074A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the change of electrifying performance of carriers in a developing vessel by discharging the developer in the developing vessel from the developer discharging port into the recovering vessel thereby keeping the developer quantity in the developer vessel at a specific amount, and appropriately executing replenishment and discharge of the developer. SOLUTION: Toner replenishing devices (42+44 to 47+C+M+SN1+SN2) replenish the toner in the toner storage vessel 44 to the developer replenishing port 42 in accordance with consumption of the toner by the developing operation. The toner consumption detecting means (48+C; 48'+C) detect the toner consumption in the developing vessel 41. Then, in response to the detected toner consumption, carrier replenishing devices (51+54+C+M) replenish the carrier in the carrier storage vessel 51 to the developer replenishing port 42 of the developer vessel 41. The developer discharging devices (43+56 to 58+C) maintain the developer amount in the developer vessel 41 at the specific amount by letting the developer in the developing vessel 41 discharged from the developer discharging port 43 to the recovering vessel 59.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for developing an electrostatic latent image formed on an image carrier into a toner image in an image forming apparatus such as an electrophotographic copying machine or a laser printer. And a developing device using a two-component developer composed of a carrier.

[0002]

2. Description of the Related Art Conventionally, in a dry copying machine or the like, a developing device for visualizing, that is, developing an electrostatic latent image on the surface of a photoreceptor using a two-component developer including a toner and a carrier has been used. In such a developing device, while the toner is consumed by the developing operation, the carrier is not consumed and remains in the developing device. Therefore, as the frequency of stirring of the carrier stirred together with the toner in the developing device increases, the situation such as adhesion of the toner to the surface occurs, and the carrier is contaminated and deteriorated. For this reason, as the charging performance of the developer gradually decreases, fogging (when the charging of the developer decreases, toner charged to the opposite polarity is generated, and the toner is transferred to the non-image area on the photoconductor during development. (Phenomenon of adhering), which causes image quality to be remarkably deteriorated.

Heretofore, in order to prevent image quality defects such as fogging, it has been necessary to periodically replace the developer in the developing container. Then, a great deal of maintenance work is required to replace the developer. Therefore, for the purpose of non-replacement of the developer, a developer composed of a mixture of a carrier and a toner is supplied to the developing container in the developing container, and the deteriorated developer having reduced charging performance is discharged from the developing container, and the charging performance is reduced. There has been proposed a device capable of suppressing the reduction. As such an apparatus, the following technology (J01)
It has been known.

(J01) Technology described in Japanese Patent Publication No. Hei 2-21591 (Japanese Unexamined Patent Application Publication No. 59-100471) The technology described in this publication is to supply a new carrier separately from the replenishment of the consumed toner. The excess developer in the developer container overflows and is discharged from a developer outlet provided in the wall surface of the developer container, and is collected in the developer collection container. By successively replenishing and discharging the carrier and the deteriorated developer, the developer contaminated and deteriorating in the developing container is sequentially replaced by the newly supplied toner and carrier. Thereby, the charging performance of the developer is maintained, and the deterioration of the image quality is suppressed.

(Problem of the above (J01)) In the developing device proposed in the above (J01), there has been proposed a method of optimally replenishing a new carrier necessary for maintaining the charging performance and suppressing the deterioration of image quality. Not. Therefore, the above (J01)
When using the technique described above, the replenishment amount of a new carrier is not optimally performed. For this reason, if the carrier is replenished more than necessary, the developer in the developing container rises from a certain optimal charging performance, and does not meet the optimally set developing conditions, resulting in a decrease in image quality. I will. Also,
Conversely, if the amount of the carrier to be replenished is small, the charging performance cannot be maintained, and the charging performance is reduced.

[0006]

Conventionally, the following developing apparatus has been proposed in order to suppress deterioration of the developer and eliminate service costs such as maintenance time caused by replacement of the developer. (A) A new developer or carrier supply unit is provided separately from the toner supply unit consumed by the developing operation. Then, by providing a portion for collecting the deteriorated developer in the developing container that has become excessive due to replenishment, the deteriorated developer in the developing container is discharged in accordance with the deterioration of the developer. However, it has not been proposed to optimally control the amount of new developer or carrier supplied from the supply section. For this reason, the charging performance was not constant due to too much or too little new developer or carrier being replenished. For this reason, it has not been possible to keep the charging performance constant under optimum conditions and maintain the image quality.

In view of the above circumstances, the present invention provides the following (O01)
Is the subject of the description. (O01) In a developing apparatus using a two-component developer, the supply and discharge of the developer are appropriately performed to reduce the change in the charging performance of the carrier in the developing container.

[0008]

Next, the present invention devised to solve the above-mentioned problems will be described. Elements of the present invention are used to facilitate correspondence with elements of the embodiments described later. , The reference numerals of the elements of the embodiment are enclosed in parentheses. The reason why the present invention is described in correspondence with the reference numerals of the embodiments described below is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(1st invention) In order to solve the aforementioned problem,
The developing device of the present invention has the following requirements: (A01) a developing roll (6) for transporting a two-component developer composed of a toner and a carrier to a developing area (Q2);
4), the two-component developer, and the developing roll (6
Developer supply member (61-63) for supplying the developer to 4)
And (A02) a toner storage container (4) in accordance with consumption of the toner by the developing operation (A02), and having a developer supply port (42) and a developer discharge port (43).
4) A toner replenishing device (42 + 44 to 47 + C + M + SN1 + SN) for replenishing the toner to the developer replenishment port (42)
2), (A03) Toner consumption detecting means (48 + C; 48 '+) for detecting the toner consumption of the developing container (41).
C), (A04) the toner consumption detecting means (48 + C;
48 '+ C) a carrier replenishing device (51-54 + C + M) for replenishing the carrier in the carrier storage container (51) to the developer replenishing port (42) in accordance with the detected toner consumption.
(A05) A collection container (59) for collecting the developer discharged from the developer discharge port (43), (A06) The developer in the development container (41) is discharged from the developer discharge port (43) through the developer discharge port (43). A developer discharging device (43 + 5) that discharges the developer to the collection container (59) and maintains the developer amount in the developing container (41) at a predetermined value.
6-58 + C).

(Second Invention) A developing device according to a second invention of the present application has the following requirements.
01) A developing roll (64) for conveying a two-component developer composed of a toner and a carrier to the developing region (Q2), the two-component developer, and a developer supply member (supplied to supply the developer to the developing roll (64)) 61 to 63), and has a developer supply port (42) and a developer discharge port (43). (B02) A toner storage container (44) according to the consumption of the toner by the developing operation. ) Supplies toner to the developer supply port (42).
2 + 44 to 47 + C + M + SN1 + SN2), (B03) toner consumption detecting means (48 + C; 48 '+ C) for detecting the toner consumption of the developing container (41), (B04) toner consumption detecting means (48 + C; 48' + C) A developer replenishing device for replenishing the two-component developer in the developer storage container to the developer replenishing port (42) in accordance with the detected toner consumption amount;
(B05) a collection container (59) for collecting the developer discharged from the developer discharge port (43); (B06) the developer in the development container (41) is discharged from the developer discharge port (43) through the developer discharge port (43); A developer discharging device (43 + 5) that discharges the developer to the collection container (59) and maintains the developer amount in the developing container (41) at a predetermined value.
6-58 + C),

(Third Invention) A developing device according to a third invention of the present application has the following requirements.
01) A developing roll (64) for conveying a two-component developer composed of a toner and a carrier to the developing region (Q2), the two-component developer, and a developer supply member (supplied to supply the developer to the developing roll (64)) 61 to 63) and a developer container (41) having a developer supply port (42) and a developer discharge port (43); (C02) a toner consumption detecting means for detecting the toner consumption of the developer container (48 + C; 4
8 '+ C), (C03) The toner consumption detecting means (48)
+ C; a developer replenishing device for replenishing the two-component developer in the developer storage container to the developer replenishing port (42) in accordance with the detected toner consumption of (48 '+ C); (C04) the developer discharging port (43) Collection container (5) for collecting the developer discharged from
9), (C05) The developer in the developing container (41) is discharged from the developer discharging port (43) to the collection container (59), and the amount of the developer in the developing container (41) is set to a predetermined value. Developer discharging device to hold (43 + 56 to 58 + C),

[0012]

Next, the operation of the present invention having the above-mentioned features will be described. (Operation of the First Invention) In the developing device according to the first invention of the present application having the above-described features, the developing container (41) having the developer supply port (42) and the developer discharge port (43) is a developing roll. (64) Two-component developer, developer supply member (61 to 6)
3) is accommodated. The developer supply members (61 to 63) supply a two-component developer to the developing roll (64). The developing roll (64) transports a two-component developer composed of a toner and a carrier to a developing area (Q2). Development area (Q2)
The toner conveyed to is consumed by the developing operation. A toner replenishing device (42 + 44 to 47 + C + M + SN1 + SN2) replenishes the toner in the toner storage container (44) to the developer replenishing port (42) in accordance with the consumption of the toner by the developing operation. Toner consumption detecting means (48 + C; 48 '+
C) detects the toner consumption of the developing container (41). The toner consumption detecting means (48 + C; 48 '+
C) The carrier replenishing device (5) according to the detected toner consumption amount
1 to 54 + C + M) are used to transfer the carrier of the carrier storage container (51) to the developer supply port (42) of the developing container (41).
Replenish. Developer discharging device (43 + 56-58 + C)
Discharges the developer in the developing container (41) from the developer discharging port (43) to the collecting container (59) to maintain the amount of the developer in the developing container (41) at a predetermined value. The collection container (59) collects the developer discharged from the developer discharge port (43). As described above, the first of the present application
The invention detects a toner consumption amount that has a strong correlation with the developer charging performance, and according to the detection result, a carrier storage container (51).
By supplying the carrier into the developing container (41), the developer can be maintained at a constant charging performance.
Since the charging performance of the developer in the developing container (41) can be kept constant, it is possible to provide an image forming apparatus capable of maintaining stable image quality from the start of use to the end of use due to life.

(Operation of the Second Invention) In the developing device of the second invention of the present application having the above-mentioned features, the developer supply port (42)
And a developing container (41) having a developer outlet (43)
Contains a developing roll (64), a two-component developer, and a developer supply member (61 to 63). Developer supply member (61-
63) supplies a two-component developer to the developing roll (64). The developing roll (64) transports a two-component developer composed of a toner and a carrier to a developing area (Q2). The toner transported to the development area (Q2) is consumed by the development operation. The toner replenishing device (42 + 44 to 47 + C + M + SN1 + SN in accordance with the consumption of the toner by the developing operation)
2) replenish the toner in the toner storage container (44) to the developer supply port (42). Toner consumption detecting means (4
8 + C; 48 '+ C) detects the toner consumption of the developing container (41). The toner consumption detecting means (48)
+ C; 48 '+ C), the developer replenishing device replenishes the two-component developer in the developer storage container to the developer replenishment port (42) of the developer container (41) in accordance with the detected toner consumption amount. The developer discharging device (43 + 56 to 58 + C) discharges the developer in the developing container (41) from the developer discharging port (43) to the collecting container (59), and discharges the developer in the developing container (41). The amount is kept at a predetermined value. The collection container (59)
Collects the developer discharged from the developer discharge port (43). As described above, the second invention of the present application detects the amount of toner consumption that is deeply correlated with the developer charging performance, and changes the two-component developer in the developer storage container according to the detection result. By replenishing the developer, the developer can be maintained at a constant charging performance. Since the charging performance of the developer in the developing container (41) can be kept constant, it is possible to provide an image forming apparatus capable of maintaining stable image quality from the start of use to the end of use due to life.

(Operation of the Third Invention) In the developing device of the third invention of the present application having the above-mentioned features, the developer supply port (42)
And a developing container (41) having a developer outlet (43)
Contains a developing roll (64), a two-component developer, and a developer supply member (61 to 63). Developer supply member (61-
63) supplies a developer to the developing roll (64).
The developing roll (64) conveys a two-component developer composed of a toner and a carrier to the developing area (Q2). The toner transported to the development area (Q2) is consumed by the development operation. Toner consumption detecting means (48 + C; 48 '+ C)
Detects the toner consumption of the developing container (41).
The developer replenishing device includes the toner consumption detecting means (48+
(C; 48 '+ C) The two-component developer in the developer storage container is supplied to the developer supply port (42) of the developer container (41) in accordance with the detected toner consumption amount. Developer discharging device (43 + 5
6 to 58 + C) discharges the developer in the developer container (41) from the developer discharge port (43) to the collection container (59) to reduce the amount of the developer in the developer container (41) to a predetermined value. Hold. The collection container (59) collects the developer discharged from the developer discharge port (43). As described above, the third invention of the present application detects the amount of toner consumption that has a strong correlation with the developer charging performance, and places the developer in the developer storage container into the developing container (41) according to the detection result. By replenishing the developer, the developer can be maintained at a constant charging performance. Since the charging performance of the developer in the developing container (41) can be kept constant, it is possible to provide an image forming apparatus capable of maintaining stable image quality from the start of use to the end of use due to life.

[0015]

Embodiment of the Invention

(Embodiment 1) Embodiment 1 of the developing device of the present invention.
(D01) A toner storage container (4) characterized in that the developing device of the first to third inventions has the following requirements.
4) The toner consumption detecting means (48) comprising a weight sensor (48 ') for detecting the weight and a controller (C) for calculating the toner consumption from a detection signal of the weight sensor (48'). '+ C).

(Operation of the First Embodiment) In the first embodiment of the developing device of the present invention, the weight sensor (48 ') of the toner consumption detecting means (48' + C) is provided in the toner storage container (44). Detect the weight of Controller (C)
Calculates the toner consumption from the detection signal of the weight sensor (48 ').

(Embodiment 2) Embodiment 2 of the developing device of the present invention is characterized in that the developing device of the first or second invention has the following requirements: (D02)
Toner replenishing device (42 + 44 to 47 + C + M + SN1 + S
N2) a driving amount detector of the toner replenishing device for detecting the driving amount (48), and a driving amount detector of the toner replenishing device (48)
The toner consumption detecting means (48 + C) constituted by a controller (C) for calculating the toner consumption from the detection signal of (4).

(Operation of the Second Embodiment) In the second embodiment of the developing device of the present invention, the toner replenishing device driving amount detector (48) of the toner consumption detecting means (48 + C) is used.
Is a toner supply device (42 + 44 to 47 + C + M + SN1
+ SN2) is detected. The controller (C)
The toner consumption is calculated from a detection signal of the toner supply device drive amount detector (48).

(Example) Next, an example (embodiment) of an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to the following example. In order to facilitate understanding of the following description, orthogonal coordinate axes X axis, Y axis, and Z axis are defined in directions of arrows X, Y, and Z orthogonal to each other in the drawings, and the arrow X direction is forward, and the arrow Y direction is Leftward, arrow Z direction is upward. In this case, the direction opposite to the X direction (front) (−X direction) is backward, and the direction opposite to the Y direction (left) (−Y
Direction) is to the right, and the opposite direction (-Z direction) to the Z direction (upward) is downward. Also referred to as the front-rear direction or the X-axis direction including the front (X direction) and the rear (-X direction), and the left-right direction or the Y-axis direction including the left (Y direction) and the right (-Y direction). In other words, the vertical direction or the Z-axis direction includes the upper part (Z direction) and the lower part (-Z direction). Furthermore, in the figure, those with "•" in "○" mean arrows pointing from the back of the paper to the front, and those with "x" in "○" are from the table on the paper. It shall mean an arrow pointing to the back.

(Embodiment 1) FIG. 1 is an overall configuration diagram of an image processing apparatus U provided with a developing apparatus according to Embodiment 1 of the present invention. FIG. 2 is an enlarged explanatory view of a main part of the first embodiment. FIG. 3 is a block diagram of the first embodiment. In FIG. 1, an image forming apparatus U has a platen glass (transparent platen) on its upper surface.
A digital copier A as an image forming apparatus main body having A1 and an automatic document feeder B detachably mounted on the platen glass A1 are provided. The automatic document feeder B sequentially takes out the documents stored in the document feed tray B1, conveys them to a copy position on the platen glass A1, and discharges the copied documents to a document discharge tray B2. It is configured.

The copying machine A includes the platen glass A1
, An image input terminal IIT (hereinafter, IIT) as an image reading unit and an image output terminal IOT (hereinafter, IOT) as an image recording operation unit.

The IIT has an exposure scanning optical system 1 below the platen glass A1. The exposure scanning optical system 1 has an exposure lamp 2 for document illumination mounted on a full rate carriage and a first mirror 3. Further, the exposure scanning optical system 1 has a second mirror 4 and a third mirror 5 mounted on a half-rate carriage that moves at half the moving speed of the full-rate carriage. It has an imaging lens 6 supported. The imaging lens 6 reflects from the original on the platen glass A1 and further reflects the first, second,
It has a function of converging the original reflected light reflected by the three mirrors 3 to 5 on a CCD (solid-state imaging device). The CCD has a function of converting the original reflected light converged on the imaging surface into an electric signal. The IIT has an image data output unit 7 for outputting an electric signal obtained by the CCD as image data, and a user interface UI for a user to input an operation command signal such as a copy start signal. The user interface UI includes a display unit UIa shown in FIG. 3, a copy start button UIb,
The display unit UIa has a copy setting number input key UIc and the like, and displays information relating to the current setting state of the image forming apparatus U.

In FIG. 1, the IOT comprises a laser drive circuit 8 for converting image data output from the image data output unit 7 into a laser drive signal,
A laser writing device 9 that emits a laser beam L for writing an image in accordance with a laser drive signal output from the printer. Laser beam L emitted from laser writing device 9
1 is incident on the surface of the image carrier 11 at a latent image writing position Q1 set on the movement path of the surface of the image carrier 11 rotating in the direction of the arrow in FIG. A charger 12 is arranged along the surface of the image carrier 11 on the rotationally upstream side of the latent image writing position Q1.

An electrostatic latent image formed on the surface of the image carrier 11 is converted into a toner image in a developing area Q2 on the downstream side in the rotation direction of the latent image writing position Q1 along the surface of the image carrier 11. A developing device D for developing (details will be described later) is provided. The transfer position Q3 set on the downstream side of the developing device D includes:
A transfer device 14 is provided. Further, a cleaner unit 16 is disposed further downstream in the rotation direction of the transfer device 14. Below the transfer unit 14, paper feed trays 21 to 21 are provided.
25 are arranged in multiple stages. The paper feed tray 23 is an intermediate tray used when circulating the recording sheet (hereinafter, sheet) S on which the first copy has been performed at the time of double-sided copying, multiple copying, or the like, and re-transmitting it to the transfer position Q3.

The sheets S of the paper feed trays 21 to 25 are conveyed to the transfer position Q3 through the first sheet conveying path 26. The transfer device 14 is disposed at the transfer position Q3, and the transfer device 14 transfers the toner image I on the surface of the image carrier 11 to the sheet S passing through the transfer position Q3. The transfer position Q3 along the surface of the image carrier 11
The developing toner concentration sensor SN2 is arranged at a position on the upstream side of. The developed toner density sensor SN2 detects the density of the toner image I and outputs it to the controller C (see FIG. 3). Image carrier 1 that has passed the transfer position Q3
After the toner remaining on the surface is collected by the cleaner unit 16, the surface of the first surface is uniformly charged again by the charger 12.

At the end of the first sheet transport path 26, the transported sheet S is temporarily stopped upstream of the transfer position Q3 in the sheet transport direction, and then temporarily stopped at the transfer position Q3.
Roll 27 and register gate 28 for carrying in
Is arranged. The sheet S to which the toner image has been transferred at the transfer position Q3 is conveyed to a fixing position Q4 through a second sheet conveying path 29 connected to the sheet discharge tray TR. The heating roll 31 and the pressure roll 32 of the fixing device F are arranged at the fixing position Q4, and heat and fix the unfixed toner image on the sheet S passing through the fixing position Q4. A discharge roller 33 for discharging sheets to the sheet discharge tray TR is provided in the second sheet transport path 29 downstream of the fixing position Q4.

In the second sheet conveying path 29, a switching gate 34 is disposed upstream of the discharge roller 33.
The switching gate 34 is used when switching the sheet conveyance direction on the second sheet conveyance path 29 to the sheet circulation path 36 or the sheet discharge tray TR. The sheet circulation path 36 is connected to the sheet reversal path 3 through the switching gate 37.
8 and the intermediate tray 23. The switching gate 37 directs the sheet S of the sheet circulation path 36 to the sheet reversing path 38 when performing double-sided copying, and directly to the intermediate tray 23 when performing multiple copying. The sheet-shaped and comb-shaped mylar gate 39 provided in the sheet reversing path 38 allows the sheet S to move downward by elastic deformation when the sheet S passing therethrough is conveyed downward. When the sheet S that has passed through 39 is conveyed upward, the intermediate tray 23
Is configured to be moved in the direction of. The sheet S once stopped at a predetermined position on the intermediate tray 23
Are transported from the intermediate tray 23 to the transfer position Q3 by the first sheet transport path 26.

FIG. 2 is an explanatory view of a main part of the developing device according to the first embodiment of the present invention. 2, the developing device D has a developing container 41. The developing container 41 is provided with the developer supply port 4.
2, and a developer outlet 43. The toner stored in the toner storage container 44 is stored in the developer supply port 42.
It is configured to be replenished from the toner transport auger 45. In FIGS. 2 and 3, an auger rotating shaft 46 that supports the toner conveying auger 45 is rotated by a developing device motor M via a clutch 47. At the right end of the auger rotation shaft 46, an encoder 48 for detecting the rotation amount of the toner transport auger 45 is provided.

In FIG. 2, the motor M for the developing device is driven by a motor driving circuit 49 for the developing device controlled by a controller C for controlling the operation of the copying machine A. While the developing device motor M is being driven, when the clutch 47 is on, the auger rotating shaft 46 and the toner conveying auger 4
5 is driven to rotate. At this time, the toner transport auger 4
5, the toner for replenishment stored in the toner storage container 44 is replenished into the developing container 41 from the developer replenishing port 42. This toner replenishment is performed by a toner concentration sensor SN1 (see FIGS. 2 and 3) in the developing container disposed in the developing container 41.
This is performed when the toner concentration in the container detected by the above-mentioned method is lower than the reference value. The toner supply is also performed when the developing toner concentration detected by the developing toner concentration sensor SN2 (see FIG. 1) is equal to or lower than a reference value. Reference numerals 42, 44 to 4
7, C, M, SN1, and SN2, the toner supply device (42 + 44 to 47 + C + M + S
N1 + SN2). An encoder 48 for detecting the amount of rotation of the toner transport auger 45
Is a toner supply device (42 + 44 to 47 + C + M + SN1
+ SN2) as a drive amount detector 48 for detecting the drive amount.

The amount of rotation of the toner transport auger 45 detected by the encoder 48 is input to the controller C. The toner supply amount into the developing container 41 is proportional to the rotation amount of the toner transport auger 45, and the controller C calculates the toner supply amount determined according to the rotation amount of the toner transport auger 45 as the toner consumption amount. ing.
Therefore, the encoder 48 and the controller C
Thus, a toner consumption detecting means (48 + C) for detecting the toner consumption of the developing container is constituted.

Above the developer supply port 42, a carrier storage container 51 and a carrier supply shutter 52 are disposed. The carrier supply shutter 52 is opened and closed by a carrier supply solenoid 53. While the carrier supply shutter 52 is open, the supply carrier stored in the carrier storage container 51 is configured to drop toward the developer supply port 42. In FIG. 3, the carrier supply solenoid 53 is used.
Is operated by a carrier supply solenoid driving circuit 54 controlled by the controller C. The developer storage container (44 + 51) of the first embodiment is constituted by the toner storage container 44 and the carrier storage container 51. Further, the components indicated by the reference numerals 51 to 54, C and M are used for the carrier replenishing device (51 to 54) of the first embodiment.
+ C + M), that is, the toner consumption detecting means (4
8 + C), a carrier replenishing device (51-54 + C + M) for replenishing the carrier of the carrier storage container 51 to the developer replenishing port 42 in accordance with the detected toner consumption amount.

The developer discharge port 43 is provided with a developer discharge shutter 56. Developer discharge shutter 5
6 is opened and closed by a developer discharge solenoid 57. In FIG. 3, a developer discharge solenoid 57 is operated by a developer discharge solenoid drive circuit 58 controlled by the controller C. A collection container 59 for collecting the discharged developer is disposed below the developer discharge port 43.
By the elements indicated by the reference numerals 43, 56 to 58, and C, the developer in the developing container 41 is discharged from the developer discharging port 43 to the collection container 59 to reduce the amount of the developer in the developing container 41. A developer discharging device (43+
56 to 58 + C).

In FIG. 2, a stirring auger 6 for stirring the two-component developer in the developing container 41 is provided inside the developing container 41.
1, 62, developer supply paddle 63, and developing roll 6
4 is rotatably supported. The stirring auger 6
The developer supply members (61 to 63) are configured by the developer supply paddles 1 and 62 and the developer supply paddle 63. Developing roll 64
Is constituted by a conventionally known fixed magnet roller 65 and a sleeve 66 rotating around its outer periphery.

In FIGS. 2 and 3, the stirring auger 6 is used.
1, 62, developer supply paddle 63, and developing roll 6
4 is rotationally driven via the clutch 68 by the developing device motor M. The augers 61 and 62 for stirring are 2
The component developer is stirred while being transported in opposite directions, and the developer supply paddle 63 supplies the stirred two-component developer to the developing roll 64. In the developing container 41, there is provided a layer thickness regulating member 69 which regulates the layer thickness of the two-component developer which is adhered to the outer surface of the developing roll 64 and conveyed to the developing area Q2. The layer thickness regulating member 69 according to the present embodiment is formed in two layers by a non-magnetic member 69a and a magnetic member 69b in the form of a laminated plate. The use of components is possible. The layer thickness regulating member 69 is disposed at a position facing the magnetic pole of the magnet roller 65.

In FIG. 3, a controller C has a CPU
(Central processing unit), a microcomputer having a ROM (read only memory), a RAM (random access memory), an I / O (input / output interface) and the like. The controller C receives a copy start signal and a set copy number input from the UI, an encoder detection signal (toner replenishment amount detection signal) 48a, a toner density signal SN1a in the container, a development toner density signal SN2a, and other input signals. Has been entered. The controller C
In response to the input signal, a motor drive circuit 49 for the developing device, a solenoid drive circuit 54 for replenishing the carrier, a solenoid drive circuit 58 for discharging the developer, a clutch actuation circuit 71 for replenishment, a clutch actuation circuit 72 for development, It outputs control signals for other operating circuits.

The ROM of the controller C stores a program that operates according to each of the input signals and necessary data. The controller C operated by the program includes a toner replenishing amount calculating unit C1, a copy number counter C2, a carrier replenishing amount calculating unit C3, a developer discharging amount calculating unit C4, and a ten-sheet counter C5 for calculating the toner amount to be replenished. Function. The toner replenishment amount calculating means C1 calculates the amount of toner to be replenished in accordance with the toner concentration signal SN1a in the developing container and the developed toner concentration signal SN2a. In order to supply the calculated toner amount, the toner supply auger 45 needs to be driven for a predetermined time. Therefore, the amount of toner to be replenished depends on the driving time of the toner replenishing auger 45, that is, the clutch 4
7 is the operation time.

The carrier replenishment amount calculating means C3 calculates the amount of carrier to be replenished according to the encoder detection signal (toner replenishment amount detection signal) 48a. The amount of carrier to be replenished is the opening time of the carrier replenishing shutter 52, that is, the operating time of the carrier replenishing solenoid 53. The developer discharge amount calculating means C4 calculates a developer discharge amount to be discharged according to the encoder detection signal (toner replenishment amount detection signal) 48a. The developer discharge amount to be discharged is the opening time of the developer discharge shutter 56, that is, the operation time of the developer discharge solenoid 57. The ten sheet counter C5 is a counter used for forming a toner image for density detection on the image carrier 11 every time ten continuous copies are performed.

(Operation of Embodiment 1) The surface of the image carrier 11 is uniformly charged to a negative polarity by the charging device 12.
Next, image exposure is performed by the laser writing device 9, and an electrostatic latent image is formed on the surface of the image carrier 11. Developing device D
The agitating augers 61 and 62 in the developing container 41 rotate in directions opposite to each other, agitate and transport the toner and the carrier supplied from the developer supply port 42, and perform the mixing action of the toner and the carrier. It is a triboelectrically charged homogeneous two-component developer. The uniformly mixed two-component developer is deposited in a layer on the peripheral surface of the developing roll 64 by the developer supply paddle 63. The developer on the surface of the developing roll 64 is formed into a uniform layer by the layer thickness regulating member 69. The uniform developer layer formed on the surface of the developing roll 64 develops the electrostatic latent image on the image carrier 11 into a toner image in the developing area Q2.

A sheet S such as a recording sheet or a transparent transfer material on which the toner image is transferred is taken out of the sheet feed trays 21 to 25 and is conveyed. Is transferred to the transfer position Q3 between the image carrier 11 and the transfer device 14 at the timing shown in FIG. At the transfer position Q3, the toner image on the image carrier 11 is transferred onto the sheet S by the transfer device 14.
Then, the sheet S on which the toner image has been transferred is fixed to the fixing device F.
Is heated and fixed, and is conveyed to the sheet discharge tray TR. After the transfer of the toner image, the toner remaining on the surface of the image carrier 11 after the transfer of the toner image is scraped off by the cleaner unit 16, and further, the electric charge remaining on the surface is removed by the charge removing device 12.

When the above copying operation is repeated,
The toner in the developer accommodated in the developing container 41 of the developing device D in FIG. 2 is gradually consumed, and the ratio of the toner to the carrier, that is, the toner concentration decreases.
This change in toner density is detected by a toner density sensor SN1 provided in the developing container 41. When the toner concentration falls below the proper range required for development, the controller C turns on the clutch 47 to drive the toner transport auger 45 to supply toner in the toner storage container 44 from the developer supply port 42. Is supplied into the developing container 41.

On the other hand, the carrier in the developer in the developing container 41 is not consumed by the developing operation, but is agitated together with the toner in the developing container 41, the influence of the magnetic force of the magnet roller 65, and Due to the influence of contact with the image carrier 11 and the toner, the toner sticks to the carrier surface, and the surface is gradually contaminated and deteriorated. When the carrier deteriorates in this way, the charging performance of the developer is reduced, and a predetermined amount of charge cannot be given to the toner, and the image quality is reduced.

FIG. 4 is an explanatory diagram showing the relationship between the developer charging performance and the toner consumption amount. FIG. 4A shows that the developer charging performance increases as the toner consumption amount increases (as the developing operation time increases). FIG. 4B is a graph showing that the higher the supply ratio of the carrier into the developer, the lower the rate of decrease of the developer charging performance, which decreases with the consumption of toner. It is. In FIG. 4A, as the toner consumption increases, the carrier charging performance decreases due to the deterioration of the carrier. In order to maintain the charging performance of the developer in the optimum range, when the toner consumption falls within the predetermined range, development is performed while exchanging a new developer containing a new carrier and a developer containing a deteriorated carrier. There is a need. By appropriately controlling the replacement amount of the developer, it is possible to maintain the developer charging performance constant. In the case where development is performed while replacing the carrier in FIG. 4B, the developer charging performance is reduced to a steady value due to the toner consumption amount, and the steady value increases as the carrier replacement amount increases. It turns out that. As can be seen from FIGS. 4A and 4B, in order to maintain the developer charging performance in the optimum range, it is necessary to exchange the carrier in a corresponding amount or the developer containing the carrier.

Next, a method of replacing the developer according to the first embodiment will be described with reference to FIG. Figure 5 shows the UI (user interface)
Copier A when the copy start button is pressed
4 is an operation control flow of FIG. In FIG. 5, when a copy start button is turned on, a density detection toner image is developed on the image carrier 11 in step ST1, and the developed toner density (the density of the developed toner image) Ta is used as the developed toner density. It is detected by the sensor SN2 (see FIG. 1).
Next, in step ST2, the detection value Ta of the developing toner concentration is obtained.
Is greater than or equal to the set reference value Tao.
If the determination in step ST2 is NO (N), the process proceeds to step ST3, in which toner is supplied in an amount corresponding to the difference between Tao and Ta, and then the process returns to step ST1. The toner replenishment of the toner replenishing device (4
2 + 44 to 47 + C + M + SN1 + SN2).

In step ST2, yes (Y)
In the case of, the process moves to step ST4. In step ST4, the developing container 4 is detected by the toner concentration sensor SN1 in the developing container.
1 is detected. Since the detected value Tb at this time is the toner concentration in the developing container when the detected value Ta of the developed toner concentration is equal to or higher than the set reference value Tao, the detected value Tb is set to the toner concentration reference value Tb in the container.
Set to o. Next, in step ST5, the count value of the ten-sheet counter n is set to “0”. That is, n = 0
And Next, in step ST6, it is determined whether or not Tb ≧ Tbo. Since Tb = Tbo was set in the step ST4, the answer is initially yes (Y). If yes (Y), copy is performed in step ST7. If no (N), copying is performed in step ST8, and at the same time, an amount of toner corresponding to the difference between Tbo and Tb is supplied.

Next, in step ST9, the count value of the ten-sheet counter n is incremented by "1".
Next, in step ST10, it is determined whether or not copying has been completed. This determination is made based on whether or not copying of the set number of copies input from the UI has been completed. If no (N), the process moves to step ST11. Next, in step ST11, n
= 10 is determined. If no (N), the process moves to step ST12. After detecting the in-container toner concentration Tb in step ST12, the process returns to step ST6. If yes (Y) in step ST11, it means that 10 copies have been made, and the process returns to step ST1.

In step ST10, if the answer is yes (Y), the process proceeds to step ST13. Step ST13
, The toner consumption Vt is calculated. Next, in step ST14, a carrier supply amount and a developer discharge amount corresponding to the toner consumption amount Vt are calculated. These calculations are performed by the carrier replenishment amount calculation means C3 and the developer discharge amount calculation means C4. Next, in step ST15, carrier supply and developer discharge are performed. Carrier replenishment is performed by the carrier replenishment device (51 to 54 + C + M), and developer discharge is performed by the developer discharge device (43 + 56).
-58 + C).

As described above, the developing toner concentration Ta is detected by the developing toner concentration sensor SN2 at the start of copying and when 10 continuous copies are made. Then, when the developing toner concentration Ta is appropriate (when Ta ≧ Tao), the toner concentration Tb in the container is detected by the toner concentration sensor SN1 in the container, and the detected value Tb at that time is used as the reference value Tb of the toner concentration in the container.
determined to o. During the copying operation, the toner concentration Tb in the container is controlled such that the toner concentration Tb in the container is equal to or higher than the reference value Tbo. That is, when the toner in the developing container 41 is consumed by the developing operation, the developing container 41
The toner concentration Tb in the container detected by the toner concentration sensor SN1 inside the container decreases. When the toner concentration Tb falls below the reference value Tbo, toner is supplied. The toner supply amount Vt is detected as toner consumption by the toner consumption detecting means (48 + C). Then, at the end of copying, the supply of the carrier and the discharge of the developer are performed according to the detected toner consumption Vt. For this reason, the charging performance of the developer in the developing container 41 can be prevented from lowering, and the charging performance can be maintained in an appropriate range, so that high image quality can be maintained.

(Embodiment 2) Next, Embodiment 2 of the developing device of the present invention will be described with reference to FIGS. FIG. 6 is a block diagram showing a configuration of a developing device D according to a second embodiment of the present invention, and corresponds to FIG. 3 of the first embodiment. FIG. 7 shows the second embodiment.
It is a flowchart of FIG. FIG. 8 is a diagram showing that the speed of deterioration of the developer charging performance varies depending on the temperature and humidity around the developing device D, and is a diagram for explaining the operation of the second embodiment.
In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The second embodiment differs from the first embodiment in the following points, but has the same configuration as the first embodiment in other points. 6, the developing toner density sensor SN2 of FIG. 3 of the first embodiment is omitted, and a temperature sensor SN3 and a humidity sensor SN4 are provided instead.

The controller C has a carrier and developer replacement amount setting means C6 per unit toner consumption. During the operation of the developing device D, the controller C
As in the first embodiment, the operation is performed so as to maintain the toner concentration in the developing container 41 at the reference value Tbo. However, the carrier and developer replacement amount setting means C6 per unit toner consumption is controlled by the temperature sensor SN3. And a function of determining a carrier supply amount Vco and a developer discharge amount Vgo per unit toner consumption according to the detection value of the humidity sensor SN4. Carrier replenishment amount Vco per unit toner consumption
And the developer discharge amount Vgo is determined by the deterioration speed of the developer charging performance, so that the carrier replenishment amount Vco per unit toner consumption corresponding to the reference temperature and humidity of the toner concentration
And the developer discharge amount Vgo must be determined. Next, a method of setting the carrier supply amount Vco and the developer discharge amount Vgo per unit toner consumption will be described. As shown in FIG. 8, when the environmental conditions around the developing device D are high temperature and high humidity,
Deterioration speed of developer charging performance is faster than normal temperature and normal humidity.
For this reason, the carrier and developer replacement amount setting means C6 per unit toner consumption is determined by the carrier supply amount Vco and the carrier supply amount per unit toner consumption determined according to the detection values SN3a and SN4a of the temperature sensor SN3 and the humidity sensor SN4. It has a table for determining the developer discharge amount Vgo. The data stored in the table can be determined by experiments using the actual developing device D.

(Operation of Second Embodiment) Next, the operation of the second embodiment will be described with reference to FIG. In FIG. 7, when the start button is turned on, in step ST21, a carrier supply amount Vco and a developer discharge amount Vgo per unit toner consumption determined according to temperature and humidity are set. This setting
The data is read from the data (data obtained by experiments) stored in the table of the carrier and developer replacement amount setting means C6 per unit toner consumption and set. Next, in step ST22, the toner concentration Tb in the container is detected.
Next, it is determined whether or not the toner concentration Tb in the container detected in step ST23 ≧ the reference value Tbo. The reference value Tbo of the second embodiment is a value set corresponding to the case of normal temperature and normal humidity, but may be set to a different value according to the temperature and humidity. If no (N), the process moves to step ST24. In step ST24, toner replenishment of an amount corresponding to the value of Tb-Tbo is performed, and then the process proceeds to step ST21.

In step ST23, if the answer is yes (Y), the process proceeds to step ST25. Step ST25
Performs one copy operation. Next, step S
At T26, the toner consumption Vt is detected from the rotation amount of the encoder 48, and the detected toner consumption Vt is integrated. Next, in step ST27, it is determined whether or not Vt ≧ Vto.
Vto is the toner consumption for determining carrier replenishment and developer discharge. If (the integrated value Vt of the toner consumption amount ≧ the toner consumption amount Vto for the determination at the time of carrier replenishment and developer discharge), the process proceeds to step ST28. In step ST28, it is determined whether the copy has been completed. If no (N), the process returns to step ST21.

In step ST27, yes (Y)
In the case of, the process moves to step ST29. In step ST29, the carrier supply amount Vc is calculated based on the accumulated toner consumption amount Vt.
o × Vt and the developer discharge amount Vgo × Vt are calculated. Next, in step ST30, carrier supply and developer discharge are performed. Next, in step ST31, the accumulated toner consumption Vt is reset. Next, the process proceeds to step ST28. If yes (Y) in step ST28, the process ends.

In the second embodiment, the same as in the first embodiment,
The supply of the carrier and the discharge of the developer are performed according to the detected toner consumption. For this reason, the charging performance of the developer in the developing container 41 can be prevented from lowering, and the charging performance can be maintained in an appropriate range, so that high image quality can be maintained. Further, it can cope with changes in temperature and humidity.

Third Embodiment Next, a third embodiment of the developing device of the present invention will be described with reference to FIG. FIG. 9 is a flowchart of the third embodiment, and corresponds to FIG. 7 of the second embodiment. In the third embodiment, the flowchart of FIG. 9 is different from the flowchart of FIG. 7 of the second embodiment, and the other points are the same as those of the second embodiment. In FIG. 9, the same processes as those in FIG. 7 are denoted by the same step numbers, and detailed description thereof will be omitted.

In step ST21 of the second embodiment, the carrier replenishment amount Vco and the developer per unit toner consumption amount are set by the carrier and developer replacement amount setting means C6 per unit toner consumption amount according to the temperature and humidity. Although the discharge amount Vgo was set, in step ST21 'of the third embodiment shown in FIG.
The toner consumption Vto for determining when the developer is discharged, that is, the toner consumption Vto for determining the developer replacement timing is set.
Therefore, in the third embodiment, the toner consumption Vt is Vt
When a value o (a value determined according to temperature and humidity) is reached, a predetermined amount of developer replacement is performed. The value of Vto determined according to temperature and humidity is stored in the controller C as a table in the memory. In the third embodiment, step ST29 of the second embodiment is omitted, and instead of step ST30, a fixed amount of carrier replenishment and developer discharge set in step ST30 'are performed irrespective of temperature and humidity.

That is, in this embodiment, when the detected value of toner consumption Vt ≧ set value Vto, a fixed amount of carrier supply and developer discharge are performed. In the case of high temperature and high humidity, the deterioration speed of the carrier is fast. Therefore, the deterioration of the carrier is prevented by shortening the interval between the carrier replenishment and the discharge of the developer by setting Vto small.
In the third embodiment, as in the second embodiment, the supply of the carrier and the discharge of the developer are performed according to the detected toner consumption. For this reason, the charging performance of the developer in the developing container 41 can be prevented from lowering, and the charging performance can be maintained in an appropriate range, so that high image quality can be maintained.

(Embodiment 4) FIG. 10 is an explanatory view of Embodiment 4 of the developing apparatus according to the present invention, and corresponds to FIG. 2 of Embodiment 1 described above. The developing device motor drive circuit 49, the developing device motor M, and the clutches 47 and 68 shown in FIG.
10, a toner supply motor drive circuit 49a, a toner supply motor M1, a development motor drive circuit 49b, and a development motor M2 are used in the fourth embodiment shown in FIG. Therefore, in the fourth embodiment shown in FIG. 10, the toner is supplied by the toner supply motor driving circuit 49a and the toner supply motor M1.
In the fourth embodiment shown in FIG. 10, the developing roller 64 is controlled by the developing motor drive circuit 49b and the developing motor M2.
And so on. Other configurations of the fourth embodiment are the same as those of the first embodiment. This Example 4 also
As in the first embodiment, the supply of the carrier and the discharge of the developer are performed according to the detected toner consumption. For this reason, the charging performance of the developer in the developing container 41 can be prevented from lowering, and the charging performance can be maintained in an appropriate range, so that high image quality can be maintained.

(Embodiment 5) FIG. 11 is a block diagram of a developing device according to a fifth embodiment of the present invention, and corresponds to FIG. 3 of the first embodiment. FIG. 12 is a flowchart of the fifth embodiment and corresponds to FIG. 5 of the first embodiment. In FIG. 11, a controller C is provided with a laser writing device 8 instead of the detection signal 48a of the encoder 48 of FIG.
, The laser writing dot number 8a is input. The controller C has a toner consumption calculating means C7 instead of the toner replenishing amount calculating means C1 of FIG. The toner consumption calculating means C7 has a table in which the number of laser writing dots 8a is integrated and the toner consumption Vt corresponding to the integrated value is stored. Has the function of calculating the toner consumption Vt from Other configurations of the fifth embodiment are the same as those of the first embodiment.

(Operation of Embodiment 5) The flowchart shown in FIG. 12 is the same as FIG. 5 except that step ST13 'is provided instead of step ST13 in FIG. In step ST13 ', the laser writing dot number 8
The toner consumption Vt is calculated from the integrated value of a. Other operations of the fifth embodiment are the same as those of the first embodiment. In the fifth embodiment, as in the first embodiment, the supply of the carrier and the discharge of the developer are performed according to the detected toner consumption. For this reason, the charging performance of the developer in the developing container 41 can be prevented from lowering, and the charging performance can be maintained in an appropriate range, so that high image quality can be maintained.

(Embodiment 6) FIG. 13 is an explanatory view of Embodiment 6 of the developing device of the present invention, and corresponds to FIG. 2 of Embodiment 1. In the sixth embodiment shown in FIG. 13, the toner storage container 44 is used instead of the encoder 48 shown in FIG.
Is provided with a weight sensor 48 'for detecting the weight of.
The detected weight signal 48a 'of the weight sensor 48' is input to the controller C. The controller C has a toner replenishment amount calculating means C1 (see FIG. 3) for calculating the toner consumption amount from the decrease amount detected by the detected weight signal 48a '. The controller C having the toner replenishment amount calculating means C1 and the weight sensor 48 'constitute a toner consumption detecting means (48 + C). Other configurations of the sixth embodiment are the same as those of the first embodiment. Example 6
In the same manner as in the first embodiment, the supply of the carrier and the discharge of the developer are performed according to the detected toner consumption. For this reason, the charging performance of the developer in the developing container 41 can be prevented from lowering, and the charging performance can be maintained in an appropriate range, so that high image quality can be maintained.

(Modifications) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, but falls within the scope of the present invention described in the appended claims. Thus, various changes can be made. Modified embodiments of the present invention will be exemplified below. (H01) In the first embodiment, the toner consumption can be calculated from the copy paper size and the number of copies. That is, once the copy paper size is determined, the average value of the amount of toner consumed by one copy paper of that size is conventionally known. Therefore, copy paper 1 having a fixed size
The toner consumption can be calculated by multiplying the average toner consumption per sheet by the number of copies. (H02) The present invention can be applied to analog copying machines, printers, facsimile machines, etc., in addition to digital copying machines. (H03) In each of the above embodiments, the developer storage container (44
+51) instead of the toner storage container 44 and the carrier storage container 51, it is possible to configure the toner storage container and the two-component developer storage container.
Further, the developer storage container can be constituted by only one two-component developer storage container storing a two-component developer having a high toner concentration. (H04) In the first embodiment, the supply of the toner and the carrier into the developing container 41 is performed by using one developer supply port 4.
2. Instead of replenishing from the above, the developing replenishment port is constituted by a separately provided toner replenishment port and carrier replenishment port, and the toner replenishment port and the carrier replenishment port are replenished with toner and carrier respectively. Is possible. Further, the developer supply port can be constituted by a separately provided toner supply port and a two-component developer supply port. In this case, the toner is supplied through the toner supply port and the two-component developer supply is started. It is possible to supply a two-component developer.

[0062]

According to the developing device of the present invention, the following effects can be obtained. (E01) In a developing device using a two-component developer, the supply and discharge of the developer can be appropriately performed, and the change in the charging performance of the carrier can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an image processing apparatus U including a developing device according to a first embodiment of the present invention.

FIG. 2 is an explanatory view of a main part of the developing device according to the first embodiment of the present invention.

FIG. 3 is a block diagram of the first embodiment.

FIG. 4 is an explanatory diagram of the relationship between developer charging performance and toner consumption. FIG. 4A shows that the charging performance of the developer increases as the toner consumption increases (to increase the time during which the developing operation is performed). FIG. 4B shows that as the supply ratio of the carrier into the developer increases, the rate of decrease of the developer charging performance decreases with the consumption of the toner. FIG.

FIG. 5 is a developer replacement flow of the copying machine A that operates when a copy start button of a UI (user interface) is input.

FIG. 6 is a block diagram showing a configuration of a developing device D according to a second embodiment of the present invention, and corresponds to FIG. 3 of the first embodiment.

FIG. 7 is a flowchart of the second embodiment.

FIG. 8 is a diagram illustrating that the speed of deterioration of the developer charging performance varies depending on the temperature and humidity around the developing device D, and is an explanatory diagram of the operation of the second embodiment.

FIG. 9 is a flowchart of a developing device according to a third embodiment of the present invention, and corresponds to FIG. 7 of the second embodiment.

FIG. 10 is an explanatory view of Embodiment 4 of the developing device of the present invention, and corresponds to FIG. 2 of Embodiment 1;

FIG. 11 is a block diagram of a developing device according to a fifth embodiment of the present invention, and corresponds to FIG. 3 of the first embodiment.

FIG. 12 is a flowchart of the fifth embodiment, and corresponds to FIG. 5 of the first embodiment.

FIG. 13 is an explanatory view of Embodiment 6 of the developing device of the present invention, and corresponds to FIG. 2 of Embodiment 1;

[Explanation of symbols]

Q2: Development area, 41: Development container, 42: Developer supply port, 43: Developer discharge port, 44: Toner storage container, 51
... Carrier storage container, 59 ... Recovery container, 64 ... Developing roll, (42 + 44-47 + C + M + SN1 + SN2) ... Toner supply device, (43 + 56-58 + C) ... Developer discharge device, (51-54 + C + M) ... Carrier supply device, (4)
8 + C): toner consumption detecting means, (61 to 63): developer supply member,

 ──────────────────────────────────────────────────の Continued from the front page (72) Inventor Tomio Onuki 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd.

Claims (3)

[Claims] 1. A developing device having the following requirements: (A01) a developing roll for transporting a two-component developer including a toner and a carrier to a developing area; the two-component developer; and the developing roll. (A02) a developing container having a developer supply member for supplying a developer therein and having a developer supply port and a developer discharge port, and (A02) developing the toner in the toner storage container in accordance with consumption of the toner by a developing operation. (A03) toner consumption detecting means for detecting the toner consumption of the developing container,
(A04) a carrier replenishing device for replenishing a carrier in a carrier storage container to the developer replenishing port in accordance with the toner consumption detected by the toner consumption detecting means; Collection container to collect, (A0
6) a developer discharging device that discharges the developer in the developing container from the developer discharging port to the collection container to maintain the amount of the developer in the developing container at a predetermined value; 2. A developing device having the following requirements: (B01) a developing roll for transporting a two-component developer including a toner and a carrier to a developing area; the two-component developer; and the developing roll. (B02) a developing container having a developer supply member for supplying a developer therein and having a developer supply port and a developer discharge port, and (B02) developing the toner in the toner storage container in accordance with consumption of the toner by a developing operation. (B03) a toner consumption detecting means for detecting a toner consumption amount of the developing container,
(B04) a developer replenishing device for replenishing the two-component developer in the developer storage container to the developer replenishing port in accordance with the toner consumption detected by the toner consumption detecting means; (B05) discharging from the developer discharging port Collection container for collecting the used developer, (B0
6) a developer discharging device that discharges the developer in the developing container from the developer discharging port to the collection container to maintain the amount of the developer in the developing container at a predetermined value; 3. A developing device having the following requirements: (C01) a developing roll for transporting a two-component developer including a toner and a carrier to a developing area; the two-component developer; and the developing roll. A developer container accommodating a developer supply member for supplying a developer to the developer container, and having a developer supply port and a developer discharge port; (C02) a toner consumption detecting means for detecting a toner consumption amount of the developer container; A) a developer replenishing device for replenishing the two-component developer in the developer storage container to the developer replenishing port in accordance with the toner consumption detected by the toner consumption detecting means; (C04) being discharged from the developer discharging port (C05) a collection container for collecting the developer, (C05) a developer discharge device for discharging the developer in the development container from the developer discharge port to the collection container, and maintaining the developer amount in the development container at a predetermined value;