JPH10186829A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the developer quantity in a developing vessel to specific amounts by maintaining the developer to the specific amounts, while move- controlling a movable shutter capable of moving between a close position for closing the developer discharging port and plural open positions with different open area corresponding to the developer quantity, and appropriately performing discharge of the developer. SOLUTION: In the case of performing the developing operation, the developer replenish device replenishes the developer to the developer replenish port. During this time, the developer amounts in the developer container 41 are detected by developer amounts detecting means (SNj+SNk). The developer in the developer container 41 is maintained to the specific amounts, by the shutter 59 disposed on the developer discharging port 49 while move-controlled between the close position for closing the developer discharging port 49 on the developer container 41 and plural open position with severally different area by the shutter controlling device corresponding to the detected developer amounts. The developer being discharged is recovered in the developer recovering container 58. In this way, the developer in the developer container 41 is maintained to the specific amounts and the stable image quality can be maintained.

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, when the charging performance of the developer gradually decreases, image quality defects such as fogging are generated, which causes the image quality to remarkably deteriorate.

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, in order to eliminate the need for replacement of the developer, the carrier and the toner are supplied to the developing container in the developing container, and the deteriorated developer having the reduced charging performance is discharged from the developing container, so that the reduction in the charging performance can be suppressed. Has been proposed. This type of technology includes
Conventionally, the following technique (J01) called "trickle developing method" is 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 discloses that a new carrier is placed in a developing container separately from replenishment of consumed toner. The replenished developer in the excess developer container overflows and is discharged from a developer discharge port provided on the developing container wall surface,
Collected in the developer collection container. By repeating such supply and discharge of the carrier and the deteriorated developer,
The developer that is contaminated and deteriorates in the developing container is replaced by 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 (J01)) In the developing device proposed in (J01), an impact is applied to the developing device when the image forming apparatus is moved or the like, and unnecessary developer is discharged unnecessarily. There is a problem that it is discharged from the.
As a countermeasure for this, the following technology (J02) is conventionally known. (J02) Technology described in JP-A-5-289506 In the technology described in this publication, a shutter member that can be opened and closed by shutter member driving means is provided at a developer discharge port.
Even if an impact is applied to the developing device when the image forming apparatus is moved or the like, necessary developer is not discharged from the developer discharge port.

(Problem of (J02)) In the developing device proposed in (J02), the shutter is opened and closed so that the amount of developer in the developing container becomes constant in accordance with the amount of developer in the developing container. Not controlling. For this reason, the optimal discharge method for discharging the developer from the inside of the developing container to maintain the charging performance and keep the image quality from deteriorating, maintaining the amount of developer in the developing container necessary for achieving the basic performance of the trickle system. Has not been proposed.

[0007]

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 developer discharge port for discharging 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. When the developer outlet is provided on the side of the developer container, the developer in the portion adjacent to the developer outlet is discharged, and the upper surface of the developer in the adjacent portion is leveled with the lower end of the developer outlet. However, the height of the upper surface of the developer at a portion away from the developer outlet is higher than that at a portion adjacent to the developer outlet. Therefore, in order for the upper surface of the developer to be totally smoothed, the developer outlet must be lower than the upper surface of the developer that requires the developer outlet. In this case, it is necessary to adjust the lower end position of the developer outlet so that the height of the entire developer becomes a predetermined value.

However, a technique for controlling the amount of the developer so that the height of the entire developer in the developing container has a predetermined value has not been proposed so far. As a result, the amount of the developer in the developing container fluctuates greatly, and stable charging performance cannot be obtained, so that stable image quality cannot be maintained. In addition, an increase in the amount of the developer causes an increase in load torque, which causes problems such as a step-out of a drive motor of a member for stirring and transporting the developer. When the amount of the developer is small, image quality defects such as auger marks and brush marks occur.

In view of the above circumstances, the present invention provides the following (O01)
Is the subject of the description. (O01) To properly discharge the developer to keep the amount of the developer in the developing container constant.

[0010]

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.

(Invention) In order to solve the above-mentioned problems, a development device of the invention has the following requirements. (A01) Two components comprising a toner and a carrier in a development area (Q2) A developing roll (R0) for transporting the developer,
Containing the two-component developer and a developer supply member (R1 + R2) for supplying a developer to the development roll (R0);
And a developer supply port (48) and a developer discharge port (49).
(A02) A developer replenishing device (H) for replenishing toner and carrier in the developer storage container (57) to the developer replenishing port (48) when performing the developing operation.
1; H2) (A03) Developer amount detecting means (SNj + SNk) for detecting the amount of developer in the developing container (41) (A04) Collection container for collecting the developer discharged from the developer discharging port (49) (58), (A05) a shutter (59) movable between a closed position for closing the developer discharge port (49) and two or more open positions having different opening areas, (A06) the developer amount detection The shutter (59) is controlled to move between the closed position and the open position in accordance with the amount of developer detected by the means (SNj + SNk) to reduce the amount of the developer in the developing container (41) to a predetermined amount. The shutter control driving device to be held (Sc1; Sc2).

(Operation) Next, the operation of the present invention having the above-described features will be described. In the developing device of the present invention having the above-described features, the developer supply member (R1 + R2) accommodated in the developing container (41) supplies a two-component developer composed of toner and carrier to the developing roll (R0). Developing roll (R
0) conveys the two-component developer to the development area (Q2). The two-component developer transported to the developing area (Q2) is consumed by the developing operation. When performing the developing operation, the developer replenishing device (H1; H2) replenishes the developer in the developer storage container (57) to the developer replenishing port (48). During this time, the developer amount in the developing container (41) is detected by the developer amount detecting means (SNj + SNk). According to the detected amount of the developer, the shutter (59) provided at the developer discharge port (49) by the shutter control driving device (Sc1; Sc2) is moved to the developer discharge port (49) of the developing container (41). The movement of the developer in the developing container (41) is maintained at a predetermined amount by controlling the movement between a closing position for closing the opening and two or more opening positions having different opening areas. The developer discharged from the developer discharge port (49) is collected in the developer collection container (58). In this manner, the amount of the developer in the developing container (41) is maintained at a predetermined amount, so that a stable charging performance can be obtained, and a stable image quality can be maintained. Further, problems such as an increase in load torque and a step-out of a drive motor for stirring and transporting the developer, which occur when the amount of the developer increases, do not occur.

[0013]

Embodiment of the Invention

(Embodiment 1) Embodiment 1 of the developing device of the present invention
(A07) An in-container toner concentration sensor (SNv) for detecting the in-container toner concentration (Tb) which is the concentration of the toner in the developing container (41), wherein the present invention has the following requirements. (A08) The developer replenishing device (H1; H2) for replenishing toner to the developer replenishing port (48) in accordance with the in-container toner concentration (Tb) detected by the in-container toner concentration sensor (SNv). When toner is supplied to the developer supply port (48) in accordance with the toner concentration (Tb) in the container, it is possible to supply high-concentration developer mixed with toner and carrier, or to supply only toner. is there. When replenishing only toner, carrier replenishment is performed separately from toner replenishment.

(Operation of the First Embodiment) In the first embodiment of the developing device of the present invention, the toner density sensor (SNv) in the developing container measures the toner density in the container which is the density of the toner in the developing container (41). (Tb) is detected. The developer replenishing device (H1; H2) replenishes the toner to the developer replenishing port (48) in accordance with the toner concentration (Tb) in the container detected by the toner concentration sensor (SNv) in the developing container. The internal toner density (Tb) is kept constant.

(Embodiment 2) Embodiment 2 of the developing device according to the present invention is characterized in that the present invention satisfies the following requirements. (A09) The developing device is developed on an image carrier (16). (A010) A toner image density sensor (SNd) for detecting a toner image density (Ta), which is the density of the toner image, and (A010) toner is supplied in accordance with the toner image density (Ta) detected by the toner image density sensor (SNd). The developer replenishing device (H1; H2) for replenishing the developer replenishment port (48). When toner is supplied to the developer supply port (48) in accordance with the toner image density (Ta), it is possible to supply high-density developer in which toner and carrier are mixed, or to supply only toner. . When replenishing only toner, carrier replenishment is performed separately from toner replenishment.

(Operation of the Second Embodiment) In the second embodiment of the developing device of the present invention, the toner image density sensor (SNd)
Detects the toner image density (Ta), which is the density of the toner image developed on the image carrier (16). Toner image density (Ta) detected by the toner image density sensor (SNd)
In response to this, the developer replenishing device (H1; H2) replenishes the toner to the developer replenishing port (48), and the toner image density (T
a) is kept constant.

(Embodiment 3) Embodiment 3 of the developing device of the present invention is characterized in that the present invention has the following requirements. (A011) Amount of toner consumed by developing operation Consumption calculation means (74) for calculating
+ C3 '), (A012) The toner consumption calculating means (74)
+ C3 ') The developer replenishing device (H1; H2) for replenishing toner to the developer replenishment port (48) according to the toner consumption calculated by (C3'). The developer replenishment according to the toner consumption. Mouth (48)
When replenishing toner, it is possible to replenish a high-concentration developer in which toner and a carrier are mixed, or replenish only toner. When replenishing only toner, carrier replenishment is performed separately from toner replenishment.

(Operation of the Third Embodiment) In the third embodiment of the developing device of the present invention, the toner consumption calculating means (74)
+ C3 ') calculates the amount of toner consumed by the developing operation. The toner consumption calculating means (74 + C
3 ′) according to the toner consumption calculated by
The developer replenishing device (H1; H2) replenishes the toner to the developer replenishment port (48), and the developer container (4) containing the toner.
The amount of toner in 1) is kept constant.

[0019]

Next, examples (embodiments) of the embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In order to facilitate understanding of the following description, arrows X, Y,
The orthogonal coordinate axes X axis, Y axis, and Z axis are defined in the Z direction, and the arrow X direction is forward, the arrow Y direction is left, and the arrow Z direction is upward. In this case, the direction opposite to the X direction (front) (−X direction) is backward, the direction opposite to the Y direction (left) (−Y direction) is right, and the direction Z (upward) is opposite (−Z direction). Is below. 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). Good,
It is referred to as a vertical direction or a Z-axis direction including 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 a view showing the overall arrangement of an image processing apparatus provided with a developing apparatus according to Embodiment 1 of the present invention.
FIG. 2 is an enlarged explanatory view of FIG. FIG. 3 is III of FIG.
FIG. 3 is a sectional view taken along line III. FIG. 4 is a sectional view taken along line IV-IV in FIG. FIG. 5 is a perspective view of the developing container of the first embodiment.
FIG. 6 is a sectional view taken along line VI-VI of FIG. FIG. 7 is a perspective view of a developer discharging shutter and a shutter control driving device provided at a developer discharging port of the developing container. FIG.
FIG. 8A is an enlarged explanatory view of the shutter and the shutter control driving device. FIG. 8A is a sectional view taken along line VIIIA-VIIIA in FIG. 8B, and FIG. 8B is a sectional view taken along line VIIIB-VIIIB in FIG. FIG. 9 is a block diagram of the first embodiment. In FIG.
The image forming apparatus U includes a digital copying machine U1 as an image forming apparatus main body having a platen glass (transparent document table) A1 on an upper surface, and an automatic document feeder U2 detachably mounted on the platen glass A1. It has. The automatic document feeder U2 has a document feed tray TRk on which documents Gi (i = 1, 2,..., N,..., Not shown) of various sizes to be copied are stacked. I have. The original placed on the original feed tray TRk is a platen glass A1.
The document Gi that has been conveyed to the upper copy position and has been copied is discharged to the document discharge tray TRh.

The copying machine U1 has a UI (user interface), an image input terminal IIT (hereinafter, referred to as IIT) as an image reading unit, and an image as an image recording operating unit which are sequentially arranged below the platen glass A1. Output Terminal IOT (I
OT) and an IP provided between the IIT and the IOT.
S (image processing system).

The UI is a part where the user inputs an operation command signal such as copy start and the like, and has a display unit, a copy start button, a copy set number input key and the like. The display section displays information relating to the current setting state of the image forming apparatus U. An IIT as an original reading device disposed below the transparent platen glass A1 on the upper surface of the copying machine main body U1 includes an exposure system registration sensor (platen registration sensor) Sp and an exposure optical system 1 arranged at a platen registration position (OPT position). have. The exposure optical system 1 has a movable lamp unit 2, and the lamp unit 2 is configured by integrating a lamp 3 for illuminating a document and a first mirror 4. Further, the exposure optical system 1 has a movable mirror unit 5 that moves at half the speed of the lamp unit 2. This moving mirror unit 5
Is composed of a second mirror 6 and a third mirror 7.

Then, the lamp unit 2 moves in the horizontal direction in FIG. 1 in parallel with the original, and the moving mirror unit 5 moves at a speed of 1/2 of the moving speed of the lamp unit 2 and a distance of 1/2. , The distance between the document Gi and the lens 8 is kept constant. During this time, the reflected light of the document Gi illuminated by the lamp 3 passes through the exposure optical system 1 and passes through the CCD (solid-state imaging device). Element). The CCD has a function of converting the original reflected light converged on the imaging surface into an electric signal.

The IPS has image read data output means 11 for adjusting the gain of an analog electric signal of a read image obtained by the CCD of the IIT, converting the analog signal into a digital signal, performing shading correction, and outputting the digital signal. ing. The IPS has a write image data output unit 12 to which the image read data output from the image read data output unit 11 is input, and the write image data output unit 12 temporarily stores the image data. It has an image memory 13 to be used. The write image data output means 12 has a function of performing data processing such as density correction and enlargement / reduction correction on the input image read data and outputting the image read data to the IOT as write image data (laser drive data). ing.

The IPS write image data output means 12
The laser drive signal output device 14 of the IOT to which the image write data (laser drive data) output by the IOT is input, outputs a laser drive signal corresponding to the input image data to an ROS (optical write scanning device, that is, a latent image). Forming device). The ROS scans an electrostatic latent image writing position Q1 on the surface of the rotating image carrier 16 with a laser beam modulated by the input laser drive signal. The image carrier 16
Around the peripheral image writing position Q1
A charging charger 17 is disposed upstream of the developing device D, a developing device D is disposed at a developing position Q2 sequentially, and a transfer device 19 is disposed at a transfer position Q3 downstream of the latent image writing position Q1. Further, a cleaner unit 20 is disposed downstream thereof. The developing position Q2 and the transfer position Q3
Between them, a toner image density sensor SNd for detecting the density of a small area toner image (that is, a patch) formed on the image carrier 16 is arranged.

In the copying machine body U1, a first sheet feeding tray T1 and a second sheet feeding tray T2 for sequentially storing sheets, an intermediate tray for temporary stock used for double-sided copying, etc. T0, a third paper supply tray T3, a fourth paper supply tray T4, and a fifth paper supply tray T5 for storing a large number of sheets are detachably stored. And the first paper feed tray T
1, a first delivery roll R11, a first separating roll device R12, and a first takeaway roll device R13 are provided, and a first feed sensor SN1 is provided in front of the first takeaway roll device R13. Are arranged. The same delivery rolls R21,... R51, discarding roll devices R22,.
Takeaway roll devices R23,... R53, feed sensors SN2,. Further, a delivery roll R01, a takeaway roll device R03, a feed sensor SN0, and the like are provided for the intermediate tray T0. The intermediate tray T0 is a tray used when circulating the recording sheet (hereinafter referred to as a sheet) S on which the first copy has been performed at the time of double-sided copying or multiple copying, and retransmitting the recording sheet S to the transfer position Q3.

At the upper right side of the first paper feed tray T1, a manual feed tray 21 is provided. The sheets conveyed from the manual feed tray 21 by the paper feed rollers R6 and R7 and the respective sheets sent out from the respective paper feed trays T1 to T5 pass through the first sheet conveyance path 22 and are transferred to the transfer position Q.
It is to be transported to 3. First sheet transport path 2
2 is the first feed sensor SN
1 and the sheet registration sensor SNy. At the end of the first sheet conveying path 22, the transfer position Q3
A registration gate 23 and a registration roll 24 for temporarily stopping the conveyed sheet S and then carrying the sheet S to the transfer position Q3 are disposed on the upstream side in the sheet conveyance direction. The transfer device 19 arranged at the transfer position Q3 transfers the toner image on the surface of the image carrier 16 to the sheet S passing through the transfer position Q3. After the toner remaining on the surface of the image carrier 16 having passed through the transfer position Q3 is collected by the cleaner unit 20, the surface of the image carrier 16 is recharged with the charger 17 again.
Is charged uniformly.

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 conveyance belt 26 of a second sheet conveyance path 25 connected to a sheet discharge tray TR. At the fixing position Q4, a pair of fixing rolls 27 and 2 including a heating roll 27 and a pressure roll 28 are provided.
A fixing device F having a fixing position Q4
Is configured to fix the unfixed toner image on the sheet S passing through the sheet S by heating and pressing. The fixing roll 27
A fixing heater 27h is built therein. In addition,
The surface temperature of the heating roll 27 is detected by a fixing temperature sensor SNt, and a fixing device discharge sensor SNf is disposed immediately after the fixing device F. A discharge roller 29 for discharging sheets to a sheet discharge tray TR is provided downstream of the fixing position Q4 in the second sheet transport path 25.
Is provided.

In the second sheet conveying path 25, a switching gate 31 is arranged upstream of the discharge roller 29.
The switching gate 31 is used when switching the transport direction of the sheet S on the second sheet transport path 25 to the direction of the sheet circulation path 32 or the sheet discharge tray TR. The sheet circulation path 32 is connected to a sheet reversing path 33 and the intermediate tray T0 via a switching gate. The switching gate 34 directs the sheet S of the sheet circulation path 32 to the sheet reversal path 33 when performing double-sided copying,
In the case of the multiple copy, the copy is made to go directly to the intermediate tray T0. The sheet-shaped and comb-shaped mylar gate 36 provided in the sheet reversing path 33 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 the switch 36 is switched back and conveyed upward, the sheet S is guided in the direction of the intermediate tray T0. Sheet S once stored in intermediate tray T0
Are transported again from the intermediate tray T0 to the transfer position Q3 by the first sheet transport path 22.

2 to 5, a developing device D disposed opposite to the image carrier 16 in the developing area Q2 contains a two-component developer composed of a negatively charged toner and a positively charged magnetic carrier. And a developing container 41 to be used. The developing container 41 includes a developing roll accommodating portion 42 for accommodating the developing roll R0, and a first developer reservoir 43 which is a first developer stirring area adjacent to the developing roll accommodating portion 42.
And a second developer pool 44 which is a second developer stirring area adjacent to the first developer pool 43. As shown in FIG. 6, between the first developer reservoir 43 and the second developer reservoir 44, partition walls 45 are provided at portions other than both ends thereof, and the first developer reservoir 43 is provided. The 43 and the second developer reservoir 44 are connected at connection portions E at both ends in the front-rear direction (X-axis direction). The first developer reservoir 43 contains a first transport member R1.
Is disposed, and a second transport member R2 is disposed in the second developer reservoir 44. The first transport member R1 is
The developer supply member is constituted by the transport member R2. The developing roll R0 is composed of a conventionally known fixed magnet roll R0a and a developing sleeve R0b rotating around its outer periphery.
As shown in FIG. 2, a layer thickness regulating member 47 for regulating the layer thickness of the developer on the developing roll R0 is disposed in the developing roll accommodating section 42. Further, a developer supply port 48 (see FIG. 4) is formed on the upper surface of the second developer reservoir 44.

In FIGS. 3, 4 and 6, a developer discharge port 49 is formed on the outer surface of the developer container 41 of the second developer reservoir 44. The developer discharge port 49 is formed on the upstream side in the transport direction from the position of the developer supply port 48 in order to reduce the rate at which the supplied new developer is discharged immediately after the supply. The above reference numerals 42 to 49
From the elements indicated by, the developing container 41 in this embodiment is
(42 to 49) are configured.

In FIG. 6, the first and second conveying members R1 and R2 are constituted by conveying screws mounted around a rotation axis, and have a rear end (-X side end) of each shaft. ), Driven gears G1 and G2 that mesh with each other are fixed. Further, the first transport member R
The first gear G1 is provided at the rear end of the shaft of the developing roll R0 (-X
(Side end). When a rotational force is transmitted to the gear G0 by a developing device motor (see FIG. 2) M1 and the gear G0 rotates, the gears G1, G
2 are also configured to rotate in opposite directions.

The first and second conveying members R1 and R2, which rotate integrally with the gears G1 and G2, cause the first and second conveying members R1 and R2 to rotate as shown in FIG.
The developer circulates in the first and second developer reservoirs 43 and 44 as shown in FIG. FIG.
, Developer supply cylinder support walls 51 are provided before and after the developer supply port 48. A developer supply cylinder 52 is adhered to the developer supply cylinder support walls 51,51. In FIG. 2, an auger rotating shaft 53 and a developer conveying auger 54 mounted around the auger rotating shaft 53 are rotatably arranged in the developer supply cylinder 52. A gear G3 is fixed to one end of the auger rotation shaft 53. The gear G3 is connected to a motor M for the developing device via a clutch Cr1 (see FIG. 2) controlled by a supply clutch operating circuit Cr1d.
Connected to one. The supply clutch operation circuit Cr1d
Are controlled by the controller C. The developing device motor M1 is driven by a developing device motor drive circuit 56 which is controlled by a controller C which controls the operation of the copying machine U1.

As shown in FIG. 5, a developer storage container 57 is connected to one end of the developer supply cylinder 52. A replenishing cylinder 57a is provided on the upper surface of the developer storage container 57, and a two-component developer having a high toner concentration (hereinafter, referred to as "high-concentration developer") supplied from the supply cylinder 57a is provided. Stored in The high-concentration developer conveyed from the developer storage container 57 into the developer supply cylinder 52 is transported by the developer transport auger 54 that rotates when the clutch Cr1 is on while the developing device motor M1 is being driven. The developer is supplied from the developer supply port 48 into the second developer reservoir 44. The replenishment of the high-concentration developer is carried out by a toner concentration sensor SNv (a sensor for detecting the toner concentration Tb in the container, see FIG. 2, hereinafter referred to as a toner concentration sensor SNv in the container) disposed in the developing container 41 during normal use. Detection signal (symbol indicating the toner concentration Tb in the container)
Is also referred to as the in-container toner density signal Tb. ) Is performed when the toner concentration Tb in the container detected is equal to or less than the reference value Tbo. The high-density developer is supplied at a predetermined timing by the toner image density sensor SNd (toner image density Ta).
2, the detection signal (symbol representing the toner image density Ta) of the toner image density sensor SNd is also referred to as a toner image density signal Tb. The above operation is also performed when the toner image density detected in step (1) is equal to or lower than the reference value.
The rotation of the motor M1 for the developing device is controlled by a clutch operating circuit Cr2d for the developing device.
) Is transmitted to the gear G0. The clutch operating circuit Cr2d for the developing device is controlled by the controller C.

In FIG. 5 to FIG.
A collection container 58 is arranged on the outer wall of the developing container 41 so as to cover the developing container 9. The collecting container 58 includes a developer collecting portion 58a for collecting the discharged developer and a support member through groove 58b.
have. A frame-shaped shutter support member 61 that supports the developer discharge shutter 59 is provided in the support member through groove 58b.
Penetrate so that it can move up and down. A developer discharge shutter 59 whose both short sides are supported by a shutter support member 61.
Is a plate-shaped member, which is movably disposed between a position at which the developer discharge port 49 is closed and two or more open positions having different opening areas. Also, a developer discharging shutter 59 is provided.
A shutter guide member 62 for guiding the developer discharge shutter 59 so as not to separate from the outer surface of the developing container 41 is formed integrally with the wall of the collecting container 58 on both short side outer surfaces of the collecting container 58. A cam contact portion 61a is provided below the long side of the developer discharge shutter 59 of the shutter support member 61. An open / close compression spring 63 is fixed to the upper end of the long side of the developer discharge shutter 59, and the other end of the spring 63 is fixed to the inner wall of the collection container 58. The opening / closing compression spring 63 is configured to be compressed in a state where the developer discharging shutter 59 closes the developer discharging port 49.

Below the cam contact portion 61a, a cam 64 is provided.
Abuts. The cam 64 is connected to a gear G4, and the gear G4 is engaged with a gear G5. The gear G5 is rotatably connected by a shutter opening / closing motor M2. As shown in FIG. 2, the shutter opening / closing motor M
2 is operated by a shutter opening / closing motor drive circuit 66 controlled by the controller C. Therefore, when the shutter opening / closing motor M2 operates, the cam 64 rotates via the gears G4 and G5 to move the developer discharging shutter 59 up and down, and a predetermined amount of the developer is discharged from the developer discharging port 49, or the developer is discharged. Is stopped so that the amount of developer in the developing container 41 is kept within a certain range. Whether the amount of the developer in the developing container 41 is maintained in a certain range is determined by the upper limit developer sensor SNj and the lower sensor height sensor SNk provided in the developing container 41. This is realized by detecting the height and the lower limit height. Incidentally, the developer upper limit sensor SNj and the developer lower limit height sensor SNk constitute a developer amount detecting means.

In FIG. 9, the 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 includes a copy start signal and a set number of copies input from the UI, a toner density signal Tb in the container, a toner image density signal Ta, a developer upper height detection signal SNja, a developer lower height detection signal SNka, , And other input signals are input. The controller C
The control signals for the supply clutch operation circuit Cr1d, the development device motor drive circuit 56, the development device clutch operation circuit Cr2d, the shutter opening / closing motor drive circuit 66, and other operation circuits are provided according to the input signal. Is output.

The ROM of the controller C stores a program operating according to each of the input signals and necessary data. The controller C operated by the program has functions of a developer replenishing amount determining means C1 for calculating the amount of the developer to be replenished, a copy number counter C2, a shutter controlling means C3, and a ten-sheet counter C4. (Developer replenishing amount determining means C1) The developer replenishing amount determining means C1 is a developer replenishing amount (operating time of the clutch Cr1) determined according to a difference between the in-container toner density signal Tb and a reference value Tbo. And the toner image density signal Ta
Has a function of determining the amount of developer supply (operating time of the clutch Cr1) determined according to the difference between the reference value Tao and the reference value Tao. The clutch Cr1 is operated for the determined operating time of the clutch Cr1.
Is operated, and the developer is supplied by the developer transport auger 54. Note that the symbols 52 to 57, G3, Cr1, M1, T
The elements indicated by a, Tb, and C1 constitute the developer supply device H1 in this embodiment.

(Shutter control means C3) When the shutter control means C3 detects that the upper surface height of the developer is higher than the developer upper limit height sensor SNj, the cam 64
To fully open the developer discharge shutter 59. When it is detected that the upper surface height of the developer is lower than the developer lower limit height sensor SNk, the cam 64 is rotated to fully close the developer discharge shutter 59. Also,
When the upper surface height of the developer in the developing container is equal to or less than the developer upper limit height and equal to or greater than the developer lower limit height, the developer discharging shutter 5 is set to the set shutter opening (for example, １ ／).
9 is moved to discharge the developer. The code 64,
66, G4, G5, M2, SNj, SNk and C3 constitute a shutter control driving device Sc1. (10-sheet counter C4) The 10-sheet counter C4 is a counter used for forming the patch (toner image for density detection) on the image carrier 16 every time 10 continuous copies are performed.

(Operation of the First Embodiment) In the first embodiment of the developing apparatus of the present invention having the above-described structure, the surface of the image carrier 16 is uniformly charged to a negative polarity by the charging device 17. . Next, exposure is performed by ROS, and an electrostatic latent image is formed on the surface of the image carrier 16. The first and second transport members R1 and R2 accommodated in the first and second developer reservoirs 43 and 44 in the developing container 41 of the developing device D rotate in directions opposite to each other, and a developer supply port is provided. The high-concentration developer supplied from 48 is stirred and conveyed, and is made into a homogeneous two-component developer triboelectrically charged by the mixing action of the toner and the carrier. The uniformly mixed two-component developer is attracted in a layer on the peripheral surface of the developing sleeve R0b by the magnetic force of the magnet roll R0a. The developer on the surface of the developing roll R0 is formed into a uniform layer by the layer thickness regulating member 47. The uniform developer layer formed on the surface of the developing roll R0 develops the electrostatic latent image on the image carrier 16 into a toner image in the developing area Q2. After the development process, the developer remaining on the developing roll R0 is separated from the surface of the developing roll R0 (that is, the developing sleeve R0b), and is stirred and transported again.

A sheet S such as a recording sheet or a transparent transfer material on which the toner image is transferred is taken out from the sheet feed trays T0 to T5, is conveyed, is temporarily stopped by a registration gate 23, and is then stopped by a registration roller 24. Is transferred to the transfer position Q3 between the image carrier 16 and the transfer device 19 at the timing shown in FIG. At the transfer position Q3, the toner image on the image carrier 16 is transferred onto the sheet S by the transfer device 19. Then, the sheet S on which the toner image has been transferred is fixed by the fixing device F.
The sheet is heated and fixed, and is discharged to the sheet discharge tray TR.
After the transfer of the toner image, the image carrier 16 is thereafter
The toner remaining on the surface is scraped off by the cleaner unit 20.

When the above-described 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 an in-container toner density sensor SNv provided in the developing container 41. When the toner concentration Tb in the container falls below an appropriate range necessary for development, the controller C turns on the clutch Cr1 to drive the developer transport auger 54 to remove the high-concentration developer in the developer storage container 57. The developer is supplied into the developing container 41 from the developer supply port 48.

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 or influenced by the magnetic force of the magnet roller of the developing roll R0. Also, due to the influence of the contact with the image carrier 16 and the toner, the toner adheres 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.
The developer circulating in the first and second developer reservoirs 43 and 44 is discharged from a developer discharge port 49 formed in a portion near the developer reservoir 44. The discharged developer is collected in the collecting section 58a of the collecting container 58. At this time, the amount of the developer in the developing container 41 is equal to the developer upper limit sensor SNj.
If it is higher, the developer discharge shutter 59 fully opens the developer discharge port 49, so that the developer in the developing container 41 is discharged. When the developer amount in the developing container 41 is lower than the developer lower limit height sensor SNk, the developer discharging shutter 59 completely closes the developer discharging port 49, so that the developer in the developing container 41 is discharged. Not done. When the upper surface height of the developer in the developing container is equal to or less than the developer upper limit height and equal to or greater than the developer lower limit height, the developer discharge shutter 59 is opened to a preset opening.

Next, a method of supplying and discharging the developer according to the first embodiment will be described with reference to FIG. FIG. 10 is an operation control flow of the copying machine when a copy start button of the UI (user interface) is input. In FIG. 10, when a copy start button is turned on, a toner image for density detection is developed on the image carrier 16 in ST1 (step 1), and the toner image density (density of the developed toner image) Ta is determined. It is detected by the toner image density sensor SNd (see FIG. 1). Next, in ST2, it is determined whether or not the detected value Ta of the toner image density is equal to or more than the set reference value Tao. If no (N) in ST2, S
The process moves to T3, where the developer (high-concentration developer) is replenished in an amount corresponding to the difference between Tao and Ta, and then returns to ST1.

In the case of YES (Y) in ST2, the operation proceeds to ST4. In ST4, the toner concentration Tb in the developing container 41 is detected by the in-container toner concentration sensor SNv. Since the detected value Tb at this time is the toner concentration in the container when the detected value Ta of the toner image density is equal to or more than the set reference value Tao, the detected value Tb is set to the toner concentration reference value Tbo in the container. Set. Next, in ST5, the count value of the ten-sheet counter n is set to “0”. That is, n = 0. In ST6, it is determined whether or not the upper surface height of the developer is higher than the upper limit position. The determination is made based on the detection signal of the developer upper limit sensor SNj.
If yes (Y), the operation moves on to ST7, and if no (N), the operation moves on to ST8. In ST7, the developer discharging shutter is fully opened. When the developer outlet 49 is fully opened, the developer in the developing container 41 can be discharged, and a predetermined amount of the developer is discharged according to the opening area.

Next, in ST8, it is determined whether or not the height of the upper surface of the developer is lower than the lower limit position. The determination is made based on the detection signal of the developer lower limit sensor SNk. If yes (Y), proceed to ST9, if no (N), ST1
Move to 0. In ST9, the developer discharging shutter is fully closed. The developer outlet 49 is completely closed, and the discharge of the developer from the developing container 41 is stopped. Next, in ST10, the developer discharge shutter opening is set to a set value. The opening area of the developer discharge port 49 has a predetermined size, and a predetermined amount of the developer is discharged from the developing container 41 according to the opening area. Next, in ST11, it is determined whether or not Tb ≧ Tbo. Since Tb = Tbo was set in ST4, the result is initially yes (Y). If yes (Y), copy is performed in ST12. If no (N), copying is performed in ST13, and at the same time, an amount of developer (high-density developer) corresponding to the difference between Tbo and Tb is supplied.

Next, in ST14, the count value of the ten-sheet counter n is incremented by "1". Then ST
At 15, it is determined whether or not copying has been completed. This judgment is UI
This is performed depending on whether or not the copying of the set number of copies input from is completed. If no (N), the process moves to ST16. Next, in ST16, it is determined whether or not n = “10”. If no (N), the process moves to ST17. After detecting the in-container toner concentration Tb in ST17, the process returns to ST6. Said S
If yes (T) at T16, it means that 10 copies have been made, and the process returns to ST1. In the case of YES (Y) in ST15, the process moves to ST18. In ST18, the developer discharge shutter is fully closed, and the developer replenishment and discharge processing ends.

As described above, the supply of the developer and the discharge of the developer are performed according to the detected toner image density and the toner density in the container. At this time, the developer discharging shutter 5
By opening and closing the developer outlet 49 entirely or with a predetermined opening area by 9, the optimum amount of developer in the developing container 41 is maintained. Therefore, when the amount of the developer in the developing container 41 is large, an excessive amount of the discharged developer increases in the developing container 41, and the charging performance of the developer in the developing container 41 is not reduced, and the charging performance is not reduced. Therefore, by increasing the amount of developer in the container by replenishing the developer more than necessary, it is possible to prevent problems such as step-out of the motor due to an increase in the load torque on the drive system such as the conveyance stirring member. Further, when the amount of the developer in the developing container 41 is small, it is possible to prevent image quality defects such as an auger mark or a brush mark, which are generated when the amount of the developer is small.

(Embodiment 2) FIG. 11 is a block diagram of Embodiment 2 of the present invention. FIG. 12 is a flowchart of the second embodiment. In the second embodiment, elements corresponding to the elements of the first embodiment are denoted by the same reference numerals, and redundant detailed description will be omitted. In the second embodiment, the ten-sheet counter C4 and the in-container toner concentration sensor SNv of the first embodiment are omitted. The operation of the above configuration will be described with reference to the flowchart of FIG. In FIG. 12, when a copy start button is turned on, a toner image for density detection is developed on the image carrier 16 in ST21 (step 21), and the toner image density (density of the developed toner image) Ta is determined. It is detected by the toner image density sensor SNd (see FIG. 1). Then ST
At 22, it is determined whether or not the detected value Ta of the toner image density is equal to or more than the set reference value Tao. In the case of No (N) in ST22, the process proceeds to ST23, in which the developer (high-concentration developer) is supplied in an amount corresponding to the difference between Tao and Ta, and then the process returns to ST21.

If the determination in ST22 is yes (Y), the process moves to ST24. In ST24, it is determined whether or not the height of the upper surface of the developer is higher than the upper limit position. The determination is made based on the detection signal of the developer upper limit sensor SNj. If yes (Y), proceed to ST25, if no (N), ST
Move to 26. In ST25, the developer discharging shutter is fully opened. When the developer outlet 49 is fully opened, the developer container 41 is opened.
The developer inside can be discharged, and a predetermined amount of the developer is discharged according to the opening area. Next, in ST26, it is determined whether or not the upper surface height of the developer is lower than the lower limit position. The determination is made based on the detection signal of the developer lower limit sensor SNk. If yes (Y), the operation moves on to ST27, and if no (N), the operation moves on to ST28. In ST27, the developer discharging shutter is fully closed. The developer outlet 49 is completely closed, and the discharge of the developer from the developing container 41 is stopped. Next, in ST28, the developer discharge shutter opening is set to a set value. The opening area of the developer outlet 49 becomes a predetermined size,
A predetermined amount of the developer is discharged from the developing container 41 according to the opening area. In ST29, copying is performed. Next, in ST15, it is determined whether or not copying is completed. This determination is made based on whether or not copying of the set number of copies input from the UI has been completed. ST1 if no (N)
Returns to ST31 if YES (Y). In ST31, the developer discharge shutter is fully closed, and the developer replenishment and discharge processing ends. Thus, the second embodiment also has the same operation as the first embodiment.

(Embodiment 3) FIG. 13 is a block diagram of Embodiment 3 of the present invention. FIG. 14 is a flowchart of the third embodiment. In the third embodiment, the same reference numerals are given to the elements corresponding to the elements of the second embodiment, and the overlapping detailed description will be omitted. In the third embodiment, an in-container toner density sensor SNv is provided in place of the toner image density sensor SNd of the second embodiment. The operation of the above configuration will be described with reference to the flowchart of FIG. In FIG. 14, when the copy start button is turned on, in ST41 (step 41),
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 ST42 ≧ the reference value Tbo. In the third embodiment, the reference value Tbo is a value set for normal temperature and normal humidity, but may be set to a different value depending on the temperature and humidity. If no (N), the process moves to ST43. In step ST43, the developer (high-concentration developer) is supplied in an amount corresponding to the value of Tb-Tbo, and the process returns to step ST41.

In ST42, if the answer is yes (Y), the process moves to ST44. In ST44, it is determined whether or not the upper surface height of the developer is higher than the upper limit position. The determination is made based on the detection signal of the developer upper limit sensor SNj. If yes (Y), proceed to ST45, if no (N), ST
Move to 46. In ST45, the developer discharging shutter is fully opened. When the developer outlet 49 is fully opened, the developer container 41 is opened.
The developer inside can be discharged, and a predetermined amount of the developer is discharged according to the opening area.

Next, in ST46, it is determined whether or not the height of the upper surface of the developer is lower than the lower limit position. The determination is made based on the detection signal of the developer lower limit sensor SNk. If yes (Y), proceed to ST47, if no (N), ST
Move to 48. In ST47, the developer discharging shutter is fully closed. The developer outlet 49 is completely closed, and the discharge of the developer from the developing container 41 is stopped. Next, in ST48, the developer discharge shutter opening is set to a set value. The opening area of the developer discharge port 49 has a predetermined size, and a predetermined amount of the developer is discharged from the developing container 41 according to the opening area. Next, a copy operation is performed in ST49.
In ST50, it is determined whether or not the copy has been completed. If no (N), the process returns to ST41, and if yes (Y), the process moves to ST51. In ST51, the developer discharge shutter is fully closed, and the developer replenishment and discharge processing ends. In this way, even if the developer is replenished in order to maintain the toner concentration in the developing container in accordance with the temperature and the humidity, the amount of the developer in the developing container is maintained at an optimum amount.

(Embodiment 4) FIG. 15 is an enlarged explanatory view of a main part of a developing container of Embodiment 4. FIG. 16 is a block diagram of the fourth embodiment. FIG. 17 is a flowchart of the fourth embodiment. In the fourth embodiment, elements corresponding to the elements of the third embodiment are denoted by the same reference numerals, and redundant detailed description is omitted. In the fourth embodiment shown in FIG. 15, the toner stored in the toner storage container 71 above the developer supply port 48 is replenished by rotating the toner conveying auger 72 and the auger rotating shaft 73 supporting the toner auger. . The auger rotating shaft 73 is rotated by a developing device motor M1 via a clutch Cr1. An encoder 74 for detecting the amount of rotation of the toner conveying auger 72 is provided at the right end of the auger rotating shaft 73.
Is provided. Above the developer supply port 48, a carrier storage container 76 and a carrier supply shutter 77 are arranged. The carrier supply shutter 77 is opened and closed by a carrier supply solenoid 78. While the carrier supply shutter 76 is open, the supply carrier stored in the carrier storage container 76 is configured to drop toward the developer supply port 48. The carrier supply solenoid 78 is provided with a carrier supply solenoid drive circuit 7 controlled by the controller C.
8 actuated.

In the fourth embodiment, the controller C
The toner replenishing amount determining means C1 'is a toner replenishing amount (operating time of the clutch Cr1) determined according to the difference (Tb-Tbo) between the detected value of the in-container toner density signal Tb and the reference value.
Has the function of determining The carrier replenishing amount determining means C5 of the controller C determines the carrier amount to be replenished (the operation time of the carrier replenishing solenoid 78) in accordance with the replenishing toner amount detected by the encoder detection signal (toner replenishing amount detection signal) 74a. Has a function to determine. The carrier replenishing solenoid 78 is operated for the determined operating time of the carrier replenishing solenoid 78, and the carrier replenishing shutter 76 is opened to replenish the carrier. The developer supply device H2 according to the present embodiment is obtained from the elements denoted by the reference numerals 71 to 74, Cr1, M1, SNv, and C1 '.
Is configured. Shutter control means C of controller C
3 'fully opens or closes the developer discharge shutter 59 in accordance with the developer upper limit height detection signal SNja and the developer lower limit height detection signal SNka of the developer composed of toner and carrier. Further, it has a function of opening the developer discharging shutter 59 to a shutter opening degree corresponding to the rotation amount of the auger rotating shaft 73. The encoder 74 and the shutter controller C3 'constitute a toner consumption calculator. The symbols 64, 66, G4, G5, M2, SNj, SNk,
The shutter control driving device Sc is driven by the element indicated by C3 '.
Make up 2.

In the replenishment and discharge processing of the toner and the carrier according to the fourth embodiment, the process at ST48 of the third embodiment is
Replaced by T61. That is, in ST61, the opening degree of the developer discharging shutter is set to the opening degree set in accordance with the rotation amount of the encoder. No (N) in ST50
In the case of, the process proceeds to ST62, and in ST62, the carrier is supplied according to the rotation amount of the encoder, and the process returns to ST41. In this way, the opening degree of the developer discharging shutter is determined according to the replenished toner amount, the developer is discharged, and the developer amount in the developing container does not become excessive or too small. Therefore, the amount of the developer in the developing container is maintained at an optimum amount in accordance with the amount of toner to be replenished, so that the same operation as in the third embodiment is achieved.

(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) The present invention can be applied to analog copying machines, printers, facsimile machines, and the like, in addition to digital copying machines. (H02) In the fourth embodiment, the toner replenishment amount (the operation time of the clutch Cr1) can be determined according to the difference (Ta−Tao) between the detected value of the toner image density signal Ta and the reference value. (H03) In the present invention, a paddle can be disposed between the developing roll and the first transport member. (H04) The developer outlet of the present invention may be provided on the bottom wall of the developing container.

[0058]

According to the developing device of the present invention, the following effects can be obtained. (E01) Since the developer is properly discharged, the amount of the developer in the developing container can be kept constant.

[Brief description of the drawings]

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

FIG. 2 is an enlarged explanatory view of FIG. 1;

FIG. 3 is a sectional view taken along line III-III of FIG.

FIG. 4 is a sectional view taken along the line IV-IV of FIG. 6;

FIG. 5 is a perspective view of the developing container of the first embodiment.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 2;

FIG. 7 is a perspective view of a developer discharging shutter and a shutter control driving device provided at a developer discharging port of the developing container.

FIG. 8 is an enlarged explanatory view of the developer discharging shutter and the shutter control driving device, and FIG.
FIG. 8B is a sectional view taken along the line IIIA-VIIIA, and FIG.
It is a VIIIB line sectional view.

FIG. 9 is a block diagram of the first embodiment.

FIG. 10 shows a UI (user interface).
5 is an operation control flow of the copying machine when the copy start button is input.

FIG. 11 is a block diagram of a second embodiment.

FIG. 12 is a flowchart of the second embodiment.

FIG. 13 is a block diagram of a third embodiment.

FIG. 14 is a flowchart of the third embodiment.

FIG. 15 is an enlarged explanatory view of a main part of the developing container of the fourth embodiment.

FIG. 16 is a block diagram of the fourth embodiment.

FIG. 17 is a flowchart of the fourth embodiment.

[Explanation of symbols]

(H1; H2): developer supply device, Q2: development area, R0:
Developing roll, R1 + R2 ... developer supply member, (Sc1; Sc
2) Shutter control driving device, SNd: toner image density sensor, SNj + SNk: developer amount detecting means, SNv: toner concentration sensor in the developing container, Ta: toner image density, Tb: toner concentration in the container 41: developing container, 48 ... developer supply port, 49 ... developer discharge port, 57 ... developer storage container, 51 ... carrier storage container, 58 ... collection container, 59 ... shutter, (74 + C
3 '): toner consumption calculating means,

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[Procedure amendment]

[Submission date] March 11, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

In the case where the developer outlet is provided on the side of the developing container, a portion of the developer adjacent to the developer outlet is discharged. Although it is leveled to the lower end side of the outlet, the height of the upper surface of the developer at a portion distant from the developer outlet is higher than the portion adjacent to the developer outlet. Therefore, in order for the upper surface of the developer to be totally smoothed, the developer outlet must be lower than the upper surface of the developer that requires the developer outlet. In this case, it is necessary to adjust the lower end position of the developer outlet so that the height of the entire developer becomes a predetermined value.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

As shown in FIG. 5, the developer supply cylinder 52
Is connected to a developer storage container 57. A replenishing cylinder 57a is provided on the upper surface of the developer storage container 57, and a two-component developer having a high toner concentration (hereinafter, referred to as "high-concentration developer") supplied from the supply cylinder 57a is provided. Stored in The high-concentration developer conveyed from the developer storage container 57 into the developer supply cylinder 52 is transported by the developer transport auger 54 that rotates when the clutch Cr1 is on while the developing device motor M1 is being driven. From the developer supply port 48 to the second developer reservoir 44.
Is to be replenished inside. The replenishment of the high-concentration developer is performed during normal use by a toner concentration sensor SNv (a sensor for detecting the toner concentration Tb in the container, see FIG. 2) disposed in the developing container 41. Is less than or equal to the reference value Tbo. The replenishment of the high-density developer is performed at a predetermined timing with the toner image density sensor SNd (sensor for detecting the toner image density Ta, FIG.
The toner image density Ta detected by the reference value Ta) is equal to the reference value Tao.
It is also performed in the following cases. The rotation of the motor M1 for the developing device is transmitted to the gear G0 via a clutch Cr2 (see FIG. 2) controlled by a clutch operating circuit Cr2d for the developing device. The clutch operating circuit Cr2d for the developing device is controlled by the controller C.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

In FIG. 5 to FIG. 8, a collecting container 58 is disposed on the outer wall of the developing container 41 so as to cover the developer outlet 49. The collecting container 58 includes a developer collecting portion 58a for collecting the discharged developer and a support member through groove 5.
8b. A frame-shaped shutter support member 6 for supporting a developer discharge shutter 59 is provided in the support member through groove 58b.
1 penetrates movably up and down. A developer discharging shutter 5 whose both short sides are supported by a shutter supporting member 61.
Reference numeral 9 denotes a plate-shaped member, which is movably disposed between a position (upper position) for closing the developer outlet 49 and two or more open positions (lower position, upper and lower intermediate positions) having different opening areas. Have been. The front and rear ends of the developer discharging shutter 59 are guided by a shutter guide member 62 formed integrally with the wall of the collecting container 58 so as not to be separated from the outer surface of the developing container 41. A cam contact portion 61a is provided below the long side of the developer discharge shutter 59 of the shutter support member 61. An open / close compression spring 63 is fixed to the upper end of the long side of the developer discharge shutter 59, and the other end of the spring 63 is fixed to the inner wall of the collection container 58. The opening / closing compression spring 63 is configured to be compressed in a state where the developer discharging shutter 59 closes the developer discharging port 49.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

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 has functions of a developer replenishing amount determining means C1 for calculating the amount of the developer to be replenished, a copy number counter C2, a shutter controlling means C3, and a ten-sheet counter C4. (Developer replenishing amount determining means C1) The developer replenishing amount determining means C1 is a developer replenishing amount (operating time of the clutch Cr1) determined according to a difference between the in-container toner density signal Tb and a reference value Tbo. And the toner image density signal Ta
Has a function of determining the amount of developer supply (operating time of the clutch Cr1) determined according to the difference between the reference value Tao and the reference value Tao. The clutch Cr1 is operated for the determined operating time of the clutch Cr1.
Is operated, and the developer is supplied by the developer transport auger 54. Note that the symbols 52 to 57, G3, Cr1, M1, T
The elements indicated by a, Tb, and C1 constitute the developer supply device H1 in this embodiment. (Copy number counter C2)
This is a counter for counting the number of copies from when the copy start button of the UI (user interface) is pressed until the copy operation is completed.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Change

[Correction contents]

In the case of YES (Y) in ST2, the process proceeds to ST4. In ST4, the toner concentration Tb in the developing container 41 is detected by the in-container toner concentration sensor SNv. Since the detected value Tb at this time is the toner concentration in the container when the detected value Ta of the toner image density is equal to or more than the set reference value Tao, the detected value Tb is set to the toner concentration reference value Tbo in the container. Set. Next, in ST5, the count value of the ten-sheet counter C4 is set to "0".
That is, n = 0. In ST6, it is determined whether or not the upper surface height of the developer is higher than the upper limit position. The determination is made based on the detection signal of the developer upper limit sensor SNj. If yes (Y), the operation moves on to ST7, and if no (N), the operation moves on to ST8. In ST7, the developer discharging shutter is fully opened. When the developer outlet 49 is fully opened, the developer in the developing container 41 can be discharged, and a predetermined amount of the developer is discharged according to the opening area.

Claims (4)

[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 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; A developer replenishing device that replenishes a replenishing port, (A03) a developer amount detecting unit that detects a developer amount of the developing container, (A04) a collecting container that collects the developer discharged from the developer discharging port,
(A05) a shutter movable between a closed position for closing the developer discharge port and two or more open positions having different opening areas; (A06) a shutter according to a developer amount detected by the developer amount detecting means; A shutter control driving device for controlling the movement of the shutter between the closed position and the open position to maintain the developer in the developing container at a predetermined amount. 2. The developing device according to claim 1, wherein: (A07) a toner concentration sensor in a container for detecting a toner concentration in the container, which is a concentration of the toner in the development container; A08) The developer replenishing device for replenishing toner to the developer replenishing port in accordance with the toner concentration in the container detected by the toner concentration sensor in the container. 3. The developing device according to claim 1, wherein the toner image density is a density of the toner image developed on the image carrier. (A010) The developer replenishing device for replenishing toner and carrier to the developer replenishment port in accordance with the toner image density detected by the toner image density sensor. 4. A developing device (A011) according to claim 1, further comprising the following requirements: a toner consumption calculating means for calculating a consumption of toner consumed by a developing operation;
(A012) The developer replenishing device for replenishing toner and carrier to the developer replenishing port according to the toner consumption calculated by the toner consumption calculating means.