JPH11231624A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent, even in the case a large quantity of fresh developer is added, the carrier of the fresh developer from being discharged in an unused state. SOLUTION: The device is composed of a first developer discharge-port opening/closing device having a first developer discharge port 57 made downstream in a container external-wall forming a first developer stir area P1, a second developer discharge port 58 made further downstream than the first developer discharge port 57, a partition wall 53 provided between the first developer discharge port 57 and the second developer discharge port 58, a shutter for opening/closing the first developer discharge port 57, and a shutter actuation device for opening/closing the shutter. The device is further composed of a shutter opening/closing control means, which outputs a shutter opening/ closing actuation signal according to the detection value of a developer quantitative increase/decrease parameter that exerts an influence on an increase/decrease in quantity of developer.

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 In the developing apparatus, the following technique (J01) called a "trickle developing method" is conventionally known. (J01) JP-B-2-21591 (JP-A-59-100)
No. 471) The technology described in this publication discloses a technology in which a new carrier is supplied into the developing container separately from the supply of the consumed toner, and the excess developer in the developing container is removed from the wall surface of the developing container. Is discharged from the developer outlet provided in the
Collected in the developer collection container. By repeating such supply and discharge of the carrier and the deteriorated developer,
The developer deteriorating in the developing container is replaced with newly supplied toner and carrier. This allows
The charging performance of the developer is maintained, and a decrease in image quality is suppressed.

[0003]

[Problem to be Solved by the Invention] (Problem of (J01)) In an image forming apparatus provided with the developing device of the trickle developing system as proposed in (J01), an environment around the image forming apparatus is considered. Fluctuations (fluctuations in temperature and humidity) change the chargeability of the developer (toner and carrier) and change the charge amounts of the toner and carrier. When the charge amount of the toner changes, the density of the developed toner image changes.
In order to keep the density of the developed toner image constant, it is necessary to keep the charge amount of the toner constant.

[0004] For example, in the case of high temperature and high humidity, the insulating properties of the toner and the carrier are reduced, so that the charging performance of the toner and the carrier is reduced as compared with the case of normal temperature and normal humidity. Therefore, the charge amount per unit weight of the toner and the carrier decreases. At this time, if the ratio of the toner to the carrier is reduced, the charge amount of the toner per unit weight of the toner increases. Therefore, it is necessary to reduce the ratio of the amount of toner to the amount of carrier in order to keep the amount of charge per unit weight of toner constant. Reduce. In addition, when the temperature and the humidity are low, the insulating properties of the toner and the carrier are increased, so that the charging performance of the toner and the carrier is increased as compared with the case of the normal temperature and the normal humidity. In this case, in order to make the charge amount per unit weight of the toner constant, it is necessary to increase the ratio of the toner amount to the carrier amount. In this case, the supply amount of the high-concentration developer is increased.

Therefore, when the environment changes to low temperature and low humidity and a large amount of the high-density developer is replenished in the container in order to keep the density of the formed image (toner image density) constant, the amount of the replenished developer becomes small. It is discharged from the inside of the developing container. However, immediately after replenishing a large amount of the high-concentration developer, when the developer corresponding to the replenished developer amount is discharged from the developing container,
The newly replenished carrier together with the toner is likely to be discharged without being used, and the carrier is wasted.

In view of the above circumstances, the present invention provides the following (O01)
Is the subject of the description. (O01) Even if a large amount of new developer is replenished due to an increase in the charging performance of the two-component developer, the carrier of the replenished new developer is not discharged in an unused state.

[0007]

Next, the present invention devised to solve the above-mentioned problems will be described. The elements of the present invention are used to facilitate correspondence with the 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 first invention of the present application has the following requirements: (A01) a developing roll (R0) for conveying a two-component developer composed of a toner and a carrier to a developing area (Q2); (A02) A developing roll accommodating section (46) accommodating the developing roll (R0), and a first developer stirring area extending in the axial direction of the developing roll (R0) adjacent to the developing roll accommodating section (46). (P1) and a portion except for the connection ports (43c, 43d, 44c) at both ends in the axial direction, which are disposed adjacent to and below the first developer stirring area (P1), are formed by the partition wall (52). A container which is partitioned from the first developer stirring area (P1) and has both ends in the axial direction connected to the first developer stirring area (P1) and extends along the partition wall (52) and the partition wall (52). The second developer stirring area (P2) formed between the outer wall and the second developer stirring area (P2) Developing container (4
1), (A03) a first developer main stirring area (47) formed at a position adjacent to the developing roll (R0) and a first developing agent extending outward in the axial direction from an end of the developing roll (R0). The first developer stirring area (P1) provided with a developer sub-stirring area (48, 48), and the first developer stirring area (P1).
The second developer main stirring area (49) and the second developer auxiliary stirring formed according to the first developer main stirring area (47) and the first developer auxiliary stirring area (48, 48) of 1), respectively. The developer container (41) having the second developer stirring area (P2) provided with the area (51, 51);
4) The upstream end of the second developer sub-stirring area (51, 51) in the developer transport direction or the first developer sub-stirring area (4).
8, 48) a developer replenishing device (61-62 + G4 + Cr2 + Cr2d +) for replenishing a new developer at the downstream end in the developer transport direction.
C), (A05) a first transport member (R1) disposed in the first developer stirring area (P1) and agitating while transporting the two-component developer in the axial direction of the developing roll (R0); A second transport member (R2) disposed in the second developer stirring area (P2) and agitating while transporting the two-component developer in a direction opposite to the first transport member (R1); (A07) the first developing device; A first developer outlet (57) provided at a downstream portion of the outer wall of the container forming the developer stirring area (P1), (A08)
A second developer outlet (58) formed on the outer wall of the container forming the developer sub-stirring area (48, 48) and downstream of the first developer outlet (57), (A09) the developing container (41) is provided between the first developer outlet (57) and the second developer outlet (58), and the amount of the developer on the first developer outlet (57) side is equal to or more than a predetermined amount. (A010) The partition (53) is formed so as to pass over the second developer discharge port (58) when it is stored in the first developer discharge port on the upstream side in the developer transport direction of the partition (53). A first connection port (43c) formed downstream of (57) for connecting the first developer stirring area (P1) to the second developer stirring area (P2); The first developer stirring area (P1) and the second developer stirring area (P2) are formed downstream of the outlet (58). The second connection port (4
3d) the connection ports (43c, 43d, 44c) having:
(A011) A shutter (74) for moving between an opening position for opening the first developer outlet (57) and a closing position for closing the first developer outlet (57) to open and close the first developer outlet (57).
A first developer outlet opening / closing device (73-76 + SLa + C + D2) having a shutter operating device (73 + 76 + SLa + C + D2) for opening and closing the shutter (74);
(A012) A shutter opening / closing control means (C5; C5;) which outputs an opening / closing operation signal of the shutter (74) in accordance with a detected value of a developer amount increasing / decreasing parameter which affects an increase / decrease of a developer amount.
C5 ').

In the case of low temperature and low humidity, if the mixing ratio of the toner and the carrier is the same, the charge amount of the toner increases. Therefore, if the mixing ratio of the toner is increased to keep the charge amount of the toner constant, the developing container ( The amount of the developer in 41) increases. When the developer in the developing container (41) is adjusted so as to increase or decrease in accordance with the charge amount of the developer, the parameters affecting the increase or decrease of the developer amount in the developing device of the first invention are as follows. For example, the following parameters (a) to (c) can be adopted. (A) Temperature and humidity around the image forming apparatus provided with the developing device of the first invention Reason: When the surroundings of the image forming apparatus are at high temperature and high humidity, the insulating properties of the toner and the carrier are reduced, so As compared with the case of wet, the charging performance of the toner and the carrier is reduced, and the charging amount per unit weight of the toner and the carrier is reduced. Further, when the surroundings of the image forming apparatus are at a low temperature and a low humidity, the insulating properties of the toner and the carrier are increased, so that the charging performance of the toner and the carrier is increased as compared with the case of the normal temperature and the normal humidity. Therefore, since the temperature and humidity around the image forming apparatus having the developing device of the first invention are related to the charge amount of the toner, the temperature and humidity around the image forming apparatus are adopted as the developer amount increase / decrease parameter. be able to.

(B) Density of Toner Image Formed as Density Test Pattern on Image Carrier Reason: When the charge amount of toner increases, the amount of toner moving onto image carrier (16) during the developing operation is reduced. As the density decreases, the density of the toner image on the image carrier (16) decreases, and when the charge amount of the toner decreases, the amount of toner moving onto the image carrier (16) during the developing operation increases. The density of the toner image on the image carrier (16) increases. Therefore, since the toner image density on the image carrier (16) is related to the toner charge amount, the toner image density on the image carrier (16) can be used as a developer amount increasing / decreasing parameter.

(C) The image density of the original set on the original platen and the set number of sheets to be copied Reason: The supply amount and consumption of the developer can be estimated from the image density of the original and the set number of sheets to be copied. The increase / decrease of the developer in the container (41) can be estimated. Therefore, since the image density of the original set on the platen and the set number of copies are related to the increase / decrease of the developer in the developing container (41), the image density of the original and the set number of copies are developed. It can be adopted as a dose increase / decrease parameter. (D) Replenishment amount of high-concentration developer Reason: When the charge amount of the toner increases, the image carrier (1
6) The density of the upper toner image decreases. In order to reduce the charge amount of the toner and keep the density of the toner image constant, it is necessary to increase the ratio of the toner in the developer. Therefore, as the density of the toner image on the image carrier (16) increases, the amount of the high-concentration developer supplied to the developing container (41) is increased so as to increase the amount of the developer supplied. Is performed. Further, when the charge amounts of the toner and the carrier decrease, the density of the toner image on the image carrier (16) increases.
The developer is replenished so as to reduce the replenishment amount of the high-concentration developer supplied into the developing container (41). Accordingly, since the replenishment amount of the high-concentration developer is related to the charge amount of the toner, the replenishment amount of the high-density developer can be used as the developer amount increase / decrease parameter.

Further, the shutter opening / closing control means (C5; C5 ') in the first aspect of the present invention causes the shutter (74) to close for a predetermined time only when the charge amount of the developer has exceeded a predetermined value. Can be configured to open, and when the temperature, humidity, and the supply amount of the high-concentration developer around the image forming apparatus having the developing device of the first invention are adopted as the charge amount parameter, The shutter opening / closing control means (C5; C5 ') determines that when the replenishment amount of the high-density developer becomes equal to or more than a predetermined value or when the temperature and humidity become equal to or less than a predetermined value, the charge amount of the developer becomes equal to or more than a predetermined value. It is possible to close the shutter (74) for a predetermined time only when the shutter is closed, and to open the shutter at other times. Further, a plurality of the first developer outlets (57) and a plurality of the second developer outlets (58) in the first invention can be provided.

(Operation of the First Invention) In the developing device of the first invention of the present application having the above configuration, the developing container (41) is adjacent to the developing roll accommodating portion (46) accommodating the developing roll (R0). Transport member (R1) disposed in a first developer stirring area (P1) extending in the axial direction of the developing roll (R0).
Agitates while transporting a two-component developer composed of a toner and a carrier in the axial direction of a developing roll (R0). A partition wall (52) which is disposed below the first developer stirring area (P1) and is connected at both ends in the axial direction, and a partition wall (52) thereof
A second transport member (R2) formed between the outer peripheral wall of the container and the second developer agitating region (P2) is formed between
The two-component developer is stirred while being transported in the opposite direction to the first transport member (R1). The two-component developer conveyed to the developing area (Q2) is consumed by the developing operation.

The deteriorated two-component developer is discharged from a first developer discharge port (57) provided on a downstream portion of the outer wall of the container forming the first developer stirring area (P1).
The developer not discharged from the first developer discharge port (57) is supplied between the first developer discharge port (57) and the second developer discharge port (58) in the developing container (41). The accumulated developer remains in the upstream portion of the provided partition wall (53), and the retained developer is located upstream of the partition wall (53) in the developer transport direction and downstream of the first developer discharge port (57). From the first connection port (43c) formed in the second developer stirring area (P2) below the first developer stirring area (P1).

When the environment around the image forming apparatus having the developing device of the first invention is at low temperature and low humidity, the insulating properties of the toner and the carrier are increased. Performance increases. Therefore, the charge amount per unit weight of the toner and the carrier increases. At this time, if the ratio of the toner to the carrier is increased, the charge amount of the toner per unit weight of the toner is reduced. Therefore, in order to always keep the charge amount per unit weight of the toner constant, it is necessary to increase the ratio of the toner to the carrier at low temperature and low humidity. In this case, the high density development by the developer supply device (61 to 62 + G4 + Cr2 + Cr2d + C) is required. In other words, the supply amount of the developer (a two-component developer having a high toner content) is increased. When the replenishment amount of the two-component developer (high-density developer) into the developer container (41) increases, the developer amount in the container increases.

On the other hand, shutter open / close control means (C5; C
5 ') outputs a shutter opening / closing operation signal according to the detected value of the developer amount increasing / decreasing parameter which affects the developer amount increasing / decreasing. In response to the shutter opening / closing operation signal, the shutter operating device (73 + 76 + SLa + C + D2) of the first developer outlet opening / closing device (73-76 + SLa + C + D2) moves the shutter (74) to the closed position, and the first developer outlet ( 57) is closed.

For this reason, the first developer outlet (57)
The developer is not discharged from the container, the amount of the developer increases, and is stored in the upstream portion of the partition wall (53), so that the replenished developer is not immediately discharged. Therefore, it is possible to prevent the replenished developer carrier from being wastefully discharged from the developing container (41). When the amount of the developer remaining in the upstream portion of the partition wall (53) becomes equal to or more than a predetermined amount, the developer moves beyond the partition wall (53). The developer that has passed through the partition (53) is stored downstream of the partition (53), and when the height of the stored developer exceeds the lower edge of the second developer discharge port (58), the lower end is removed. The developer exceeding the edge is discharged from the second developer discharge port (58). The developer not discharged from the second developer discharge port (58) is supplied to the developer supply device (61 to 62 + G4 + Cr2 +
With the developer supplied from (Cr2d + C), the developer falls from the second connection port (43d) to the second developer stirring area (P2), circulates, and is again conveyed to the first developer stirring area (P1). .

(Second Invention) A developing device according to a second invention of the present application has the following requirements.
01) a developing roll (R0) for transporting a two-component developer composed of a toner and a carrier to a developing area (Q2); (B02) a developing roll accommodating section (46) accommodating the developing roll (R0); A first developer stirring area (P1) extending in the axial direction of the developing roll (R0) adjacent to the roll accommodating portion (46); and the developing roll (R0) adjacent to the first developer stirring area (P1). ), And a portion excluding the connection ports (43c, 43d, 44c) at both ends in the axial direction is partitioned by the partition wall (52) into the first developer stirring area (P).
1), and both ends in the axial direction are connected between the first developer stirring area (P1) and are formed between the partition wall (52) and a container outer wall extending along the partition wall (52). A developing container (41) having a second developer stirring area (P2), and (B03) a first developer main stirring area (47) formed at a position adjacent to the developing roll (R0) and the developing roll ( A first developer stirring area (P1) provided with a first developer sub-stirring area (48, 48) extending axially outward from an end of the first developer stirring area (P0); P1) First developer main stirring area (47) and first developer
The second developer agitation provided with a second developer main agitation area (49) and a second developer auxiliary agitation area (51, 51) formed according to the developer auxiliary agitation area (48, 48). The developing container (41), (B04) having an area (P2).
A first transport member (R1) disposed in the first developer stirring area (P1) and agitating while transporting the two-component developer in the axial direction of the developing roll (R0); (B05) the second developer stirring area; A second transport member (R2) disposed in (P2) and agitating while transporting the two-component developer in a direction opposite to the first transport member (R1); (B06) the first developer agitating region (P1);
A first developer discharge port (57) provided at a downstream portion of the outer wall of the container that forms the first developer sub-stirring area (48, 48); A second developer outlet (58) formed downstream of the developer outlet (57), (B08) the second developer outlet (58)
The second developer sub-stirring area (5
1, 51) to supply a new developer.
1-62 + G4 + Cr2 + Cr2d + C), (B09) the first developer outlet provided between the first developer outlet (57) and the second developer outlet (58) in the developing container (41). When the developer on the (57) side is accumulated in a predetermined amount or more, the partition (53) is formed so as to pass over the second developer outlet (58), and (B010) the developer transport direction of the partition (53). A first connection port formed on the upstream side and downstream of the first developer discharge port (57) to connect the first developer stirring area (P1) and the second developer stirring area (P2). (43c) and a second connection formed downstream of the second developer discharge port (58) and connecting the first developer stirring area (P1) and the second developer stirring area (P2). Port (43c, 43d, 44) having a port (43d).
c), (B011) a shutter (7) that moves between an opening position for opening the first developer outlet (57) and a closing position for closing the first developer outlet (57) to open and close the first developer outlet (57).
4) and a shutter operating device (73 + 76 + SLa + C + D2) for opening and closing the shutter (74).
Developer outlet opening / closing device (73 to 76 + SLa + C + D
2), (B012) The shutter (7) according to the detected value of the developer amount increase / decrease parameter that affects the increase / decrease of the developer amount.
4) A shutter opening / closing control means (C5) for outputting a shutter opening / closing operation signal for opening / closing the shutter.

As the developer amount increasing / decreasing parameter affecting the developer amount increasing / decreasing in the developing device of the second invention, the parameters exemplified as the developer amount increasing / decreasing parameter in the developing device of the first invention can be adopted. . Further, the shutter opening / closing control means (C5) in the second aspect of the invention is configured to close the shutter (74) for a predetermined time only when the charge amount of the developer becomes equal to or more than a predetermined value, and to open the shutter at other times. Temperature around the image forming apparatus including the developing device of the second invention,
When the humidity or the supply amount of the high-concentration developer is used as the charge amount parameter, the shutter opening / closing control means (C5)
A shutter (7
It can be configured to close 4) and close at other times. Further, a plurality of the first developer outlets (57) and a plurality of the second developer outlets (58) in the second invention can be provided.

(Operation of the Second Invention)
In the developing device of the present invention, the first developer stirring area (P1)
The second developing device is disposed between the partition wall (52) and the container outer wall extending along the partition wall (52), which is disposed adjacent to the developing roller (R0) on the side opposite to the developing roll (R0) and connected at both ends in the axial direction. The operation is the same as that of the developing device of the first aspect of the invention except that the agent stirring area (P2) is formed.

That is, when the environment around the image forming apparatus provided with the developing device of the second invention is at a low temperature and a low humidity, the charging performance of the toner and the carrier is improved as compared with the case of the normal temperature and the normal humidity. Therefore, in order to always keep the charge amount per unit weight of the toner constant, it is necessary to increase the ratio of the toner to the carrier at low temperature and low humidity. In this case, the high density by the developer replenishing device (61-62 + G4 + Cr2 + Cr2d + C) is required. The supply amount of the developer (a two-component developer having a high toner content) is increased, and the amount of the developer in the container is increased.

On the other hand, the shutter opening / closing control means (C5) outputs a shutter opening / closing operation signal in accordance with the detected value of the developer amount increasing / decreasing parameter which affects the developer amount increasing / decreasing. In response to the shutter opening / closing operation signal, the shutter operating device (73 + 76 + SLa + C + D2) of the first developer outlet opening / closing device (73-76 + SLa + C + D2) operates the shutter (74).
Is moved to the closed position, and the first developer outlet (57)
Is closed.

Therefore, the first developer outlet (57)
The developer is not discharged from the container, the amount of the developer increases, and is stored in the upstream portion of the partition wall (53), so that the replenished developer is not immediately discharged. Therefore, it is possible to prevent the replenished developer carrier from being wastefully discharged from the developing container (41). When the amount of the retained developer exceeds a predetermined amount, the developer gets over the partition (53) and accumulates on the downstream side of the partition (53). When the height of the upper surface of the stored developer exceeds the lower edge of the second developer outlet (58), the developer exceeding the lower edge is discharged from the second developer outlet (58). The developer not discharged from the second developer discharge port (58) is discharged from the second connection port (43d) together with the developer supplied from the developer supply device (61 to 62 + G4 + Cr2 + Cr2d + C). It moves to the stirring area (P2) and circulates,
It is transported again to the first developer stirring area (P1).

[0024]

(Embodiment 1 of the present invention) Embodiment 1 of the present invention is characterized in that the first invention satisfies the following requirement (A013) (A013) The developer transported between the developing roll (R0) and the second transport member (R2) is disposed between the developing roll (R0) and the second transport member (R2). A staying developer transport member (R3) that transports the toner while stirring it in the opposite direction to the member (R2). (Operation of the First Embodiment of the First Invention) In the first embodiment of the first invention of the present application having the above-described structure, the position between the developing roll (R0) and the second transport member (R2) is set. The staying developer conveying member (R3) arranged stirs the developer remaining between the developing roll (R0) and the second conveying member (R2) in a direction opposite to the second conveying member (R2). While transporting. For this reason, the developer can be prevented from staying between the developing roll (R0) and the second transport member (R2).

[0025]

Next, examples (embodiments) of the embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. To facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The directions indicated by Z, -Z or the sides indicated are forward, rearward, leftward, rightward, upward, downward,
Or, the front side, the rear side, the left side, the right side, the upper side, and the lower side.
Also, in the figure, those with “•” in “○” mean arrows pointing from the back of the paper to the front, and those with “x” in “○” indicate the arrow on the paper. From the back to the back.

(Embodiment 1) FIG. 1 is an explanatory view of an entire image forming apparatus provided with a developing device according to Embodiment 1 of the present invention. FIG.
FIG. 2 is an enlarged explanatory view of a main part of FIG. FIG. 3 is an explanatory view of a developing container of the developing device according to the first embodiment of the present invention, and FIG.
3B is a sectional view taken along the line IIIA-IIIA, and FIG. 3B is a sectional view taken along the line IIIB-IIIB in FIG.
3C is a sectional view taken along line IIIC-IIIC of FIG. FIG. 4 is an explanatory diagram of a gear of the developing container. FIG. 5 is a sectional view taken along line VV of FIG. 3C. FIG. 6 is a perspective view of the developing container. FIG. 7 is an enlarged explanatory view around the developer discharge port of the developing container, as viewed from the direction of the arrow VII in FIG.
FIG. 8 is a schematic explanatory view of the first developer outlet opening / closing device.
FIG. 9 is a block diagram of the developing device of the first embodiment. FIG.
The image forming apparatus U includes a digital copying machine U1 as a main body of the image forming apparatus having a platen glass (transparent document table) A1 on an upper surface, and an automatic document feeder detachably mounted on the platen glass A1. An apparatus U2 is provided. The automatic document feeder U2 has a document feed tray TRk on which documents Gi (i = 1, 2,...) Of various sizes to be copied are stacked. The document Gi placed on the document feed tray TRk is transported to a copy position on the platen glass A1, and the copied document Gi is discharged to the document discharge tray TRh.

The copying machine U1 has a UI (user interface), an IIT (image input terminal) as an image reading unit and an IOT as an image recording operating unit which are sequentially arranged below the platen glass A1.
(Image output terminal) and an IPS (image processing system) provided between the IIT and the IOT.

The UI is a part where the user inputs and operates an operation command signal such as a copy start signal.
Copy start button UIb, copy setting number input key U
Ic etc. The display unit UIa includes an image forming apparatus U.
The display of information relating to the current setting state is performed. The IIT disposed below the transparent platen glass A1 on the upper surface of the copying machine body U1 has an exposure system registration sensor (platen registration sensor) Sp and an exposure optical system 1 arranged at a platen registration position (OPT position). I 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 half 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, performing shading correction, etc., converting the signal into a digital signal, and outputting the digital signal. ing. The IPS also has a write image data output unit 12 to which image read data (digital signal) output from the image read data output unit 11 is input, and the write image data output unit 12 outputs the image data. It has an image memory 13 for temporarily storing. The write image data output means 12
It has a function of performing data processing such as density correction and enlargement / reduction correction on the input image read data and outputting the data as write image data (laser drive data) to the IOT.

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. A charging charger 17 is arranged around the image carrier 16 along the rotation direction and upstream of the latent image writing position Q1, and is sequentially arranged downstream of the latent image writing position Q1. The developing device D is disposed at the developing position Q2, the transfer device 19 is disposed at the transfer position Q3, and the cleaner unit 20 is further disposed downstream thereof. A toner image density sensor SNd for detecting the density of a density detection toner image (that is, a patch) having a small area formed on the image carrier 16 is disposed between the development position Q2 and the transfer position Q3. ing.

In the copying machine main body U1, a first sheet feeding tray T for storing recording sheets is sequentially arranged downward.
1, a second paper supply tray T2, an intermediate tray T0 for temporary stock used for duplex copying, a third paper supply tray T3, a fourth paper supply tray T4, a fifth paper supply tray T5 for storing a large number of recording sheets. Is detachably stored. The intermediate tray T0
Is a tray used when circulating the recording sheet S on which the first copy has been performed and re-sending the same to the transfer position Q3 during double-sided copying or the like.

At the upper right side of the first paper feed tray T1, a manual feed tray 21 is provided. The recording sheets conveyed from the manual feed tray 21 by the paper feeding rollers R6 and R7 and the recording sheets sent out from the paper feeding trays T1 to T5 pass through the first sheet conveying path 22 to the transfer position Q3. It is designed to be transported. The recording sheet conveyed through the first sheet conveyance path 22 is detected by the sheet registration sensor SNy. The first sheet conveying path 22
At the end of the registration gate 23 for temporarily stopping the recording sheet S conveyed to the upstream side of the transfer position Q3 in the sheet conveyance direction and then carrying the recording sheet S to the transfer position Q3.
And a registration roll 24. Transfer position Q3
The transfer device 19 arranged at the position transfers the toner image on the surface of the image carrier 16 to the recording sheet S passing through the transfer position Q3. The toner remaining on the surface of the image carrier 16 having passed the transfer position Q3 is
After being collected by the charging device 17, the charging device 17 uniformly charges again.

The recording sheet S on which the toner image has been transferred at the transfer position Q3 is connected to a second sheet discharge tray TR.
The fixing position Q passes through the conveying belt 26 of the sheet conveying path 25.
Conveyed to 4. At the fixing position Q4, a pair of fixing rolls 27 composed of a heating roll 27 and a pressure roll 28,
A fixing device F having a fixing position Q
The unfixed toner image on the recording sheet S passing through the sheet 4 is fixed by heating and pressing. A fixing heater 27h is built in the fixing roll 27.
The surface temperature of the heating roll 27 is determined by the fixing temperature sensor SNt.
, And a fixing device discharge sensor SNf is disposed immediately after the fixing device F. The second
The sheet transport path 25 is provided with a discharge roller 29 for discharging a recording sheet to the sheet discharge tray TR downstream of the fixing position Q4.

In the second sheet conveying path 25, a switching gate 31 is disposed upstream of the discharge roller 29.
The switching gate 31 is used when switching the transport direction of the recording sheet S on the second sheet transport path 25 to the sheet circulation path 32 or the sheet discharge tray TR.
The sheet circulation path 32 is connected to a sheet reversal path 33 and the intermediate tray T0 via a switching gate.
The switching gate 34 directs the recording sheet S of the sheet circulation path 32 to the sheet reversing path 33 when performing double-sided copying. The sheet-shaped and comb-shaped mylar gate 36 provided in the sheet reversing path 33 includes:
When the passing recording sheet S is conveyed downward, it is elastically deformed to allow the recording sheet S to move downward, and when the recording sheet S passing through the mylar gate 36 is switched back and conveyed upward. Are configured to be guided in the direction of the intermediate tray T0. The recording sheet S once stored in the intermediate tray T0 is configured to be re-transported from the intermediate tray T0 to the transfer position Q3 by the first sheet transport path 22.

In FIG. 2, FIG. 3, and FIG.
A developing device D disposed opposite to the image carrier 16
Has a developing container 41 containing a two-component developer composed of a negatively charged toner and a positively charged magnetic carrier. The developing container 41 has a developing container main body 42. At the front end (X-side end) of the developing container main body 42, a front connection member 43 having a configuration in which a cylindrical upper cylindrical portion 43a and a lower cylindrical portion 43b extending forward are integrally formed is provided. A rear connection member 44 is also provided at the rear end (-X side end) of the developing container main body 42. The rear connection member 44 is formed by integrally forming an upper cylindrical portion 44a and a lower cylindrical portion 44b extending rearward. .

In FIG. 5, a developing container main body 42 of the developing container 41 includes a developing roll accommodating portion 46 for accommodating the developing roll R0, and a first developer main stirring area adjacent to the developing roll accommodating portion 46. And the first main developer pool 47 is formed of the upper cylindrical portion 43 of the front connection member 43 and the rear connection member 44.
The first developer sub-reservoir (first developer sub-stirring area) 48, 48 provided in the first and second a, 44a is in communication with the first developer sub-reservoir (first developer sub-stirring area) 48, 48. Further, the developing container main body 42 is provided with the first developer main pool 47.
A second main developer pool 49 that is a second main developer stirring area below the second main developer pool 49.
Communicates with second developer sub-pools (second developer sub-stirring regions) 51, 51 provided in the lower cylindrical portions 43b, 44b of the front connection member 43 and the rear connection member 44, respectively. . The first developer main pool 47 and the first developer sub-pools 48 constitute a first developer pool P1, which is a first developer stirring area. The pool 49 and the first developer sub-pools 51, 51 form a second developer pool P2 which is a second developer stirring area.

Referring to FIGS. 3B, 3C and 5, the first
Developer main reservoir 47 and second developer main reservoir 49
A partition wall 52 is provided therebetween. Further, as shown in FIG. 5, a partition 53 is disposed in the first developer sub-pool 48 inside the upper cylindrical portion 43a of the front connection member 43. When the developer conveyed from behind the partition 53 (−X direction) accumulates a predetermined amount or more behind the partition 53, the partition 53 is located in front of the partition 53 (X direction).
It is formed to get over. As shown in FIG. 5, a first connection port 43 is provided in the front-rear direction (X-axis direction) of the partition wall 53 disposed in the first developer sub-pool 48.
c and a second connection port 43d are formed so that the first connection port 43c and the second connection port 43d connect the first developer sub-pool 48 to the second developer sub-pool 51 below. It has become. Also, the rear connection member 44
The upper cylindrical portion 44a and the lower cylindrical portion 44b are also connected by the third connection port 44c. Therefore, the first developer pool P1 is connected to each of the connection ports 43c, 43d, and 44c.
And the second developer reservoir P2 are connected.

Referring to FIGS. 3B, 3C and 5, the first
A first transport member R1 is disposed in the developer reservoir P1, and a second transport member R2 is disposed in the second developer reservoir P2. Further, the second transport member R2 and the developing roll R0
A stagnant developer conveying member R3 is disposed between the two.
The staying developer conveying member R3 is a member for stirring and conveying the developer staying between the second conveying member R2 and the developing roll R0. The first transport member R1, the second transport member R2, and the staying developer transport member R3 constitute a developer stirring transport member (R1 + R2 + R3). In FIG. 3C, the developing roll R0 is a conventionally known fixed magnet roll R0a.
And a developing sleeve R0b that rotates around its outer periphery. Further, as shown in FIG. 3C, a layer thickness regulating member 54 for regulating the layer thickness of the developer on the developing roll R0 is disposed in the developing roll accommodating portion 46. Further, a developer supply port 56 (see FIGS. 2, 5, and 6) is formed in the upper cylindrical member 43a of the front connection member 43.

3B and 5 to 7, a first developer outlet 57 is formed on the outer surface of the upper cylindrical portion 43a of the front connecting member 43, and the first developer outlet 5
A second developer discharge port 58 is formed in front of (in the X direction). The first developer outlet 57 and the second developer outlet 58 are formed on the front side (X side) and the rear side (−X side) of the partition wall 53 disposed in the upper cylindrical portion 43a. As described above, the developing containers 41 (42 to 58) in the present embodiment are constituted by the elements indicated by the reference numerals 42 to 58.

In FIG. 4, the first and second conveying members R1 and R2 are constituted by conveying screws mounted around a rotation axis, and the rear end portion (-X) of the shaft of the first conveying member R1. The driven gear G1 is fixed to the side end). The gear G1 is meshed with a driven gear Ga, the gear Ga is meshed with a driven gear Gb, and the gear Gb is at a rear end (-X side end) of the shaft of the second transport member R1. It is in mesh with the fixed driven gear G2. A gear G2 'coaxial with the gear G2 of the second conveying member R2 meshes with a gear G3 mounted on the rear end (-X side end) of the shaft of the staying developer conveying member R3. The gear G3 meshes with a driven gear Gc,
The gear Gc meshes with a gear G0 mounted on the rear end (-X side end) of the shaft of the developing roll R0. The shaft which rotates integrally with the gear G0 has a clutch (see FIG. 9).
Gear G0 'is mounted via Cr1.

The torque of the developing device motor M1 (see FIG. 9) is transmitted to the gear G0 via the gear G0 'and the clutch Cr1.
Is transmitted to When the gear G0 rotates, the gears Gc and G3 rotate, and the gears G2 'and G2 rotate in a direction opposite to the rotation direction of the gear G0. Further, the gear G2
Is rotated so that the gear G1 rotates in the opposite direction to the gear G2 via the gears Gb and Ga. The clutch operating circuit Cr1d for the developing device for controlling ON / OFF of the clutch Cr1 (see FIG. 9) is controlled by the controller C.

Then, the first and second transport members R1 and R2, which rotate integrally with the gears G1 and G2, cause
As shown in the figure, the developer circulates in the first developer reservoir P1 and the second developer reservoir P2. In FIG. 2, a developer supply cylinder support member 61 is disposed above the developer supply port 56 of the upper cylindrical portion 43a constituting the front connection member 43 of the developer container 41.
A developer supply cylinder 62 is adhered to the developer supply cylinder support member 61. In FIG. 2, a replenishment developer conveying member 63 having an auger rotating shaft 63a and a blade 63b mounted around the auger rotating shaft 63 is rotatably arranged in the developer replenishing cylinder 62. A gear G4 (see FIG. 2) is fixed to one end of the auger rotating shaft 63a. The gear G4 is connected via a clutch Cr2 (see FIG. 9) controlled by a supply clutch operating circuit Cr2d (see FIG. 9). Motor M for developing device
Connected to one. The supply clutch operation circuit Cr2d
Is controlled by the controller C. The developing device motor M1 is driven by a developing device motor drive circuit D1 (see FIG. 9) controlled by the controller C.

In FIG. 2, a developer supply case 64 is disposed above the developing container 41. The developer supply case 64 is provided with a two-component developer having a high toner concentration (hereinafter, referred to as a two-component developer).
A developer storage container 66 in which a “high-concentration developer” is stored and a developer stirring container 67 provided below the developer storage container 66. The two-component developer (high-concentration developer) supplied from the developer storage container 66 to the developer stirring container 67 is supplied to the replenishing developer transport member 63 of the developer replenishing cylinder 62 in the developer stirring container 67. The developer is agitated while being circulated in synchronization with the rotation and supplied to the developer supply cylinder 62. The reference numerals 61 to 61
A developer replenishing device (61 to 62 + G4 + Cr2 + Cr2d + C) is constituted by the components indicated by 62, G4, Cr2, Cr2d, and C.

The high-concentration developer supplied from the developer storage container 66 into the developer replenishing cylinder 62 is supplied with the replenishing developer which is driven to rotate when the clutch Cr2 is ON while the developing device motor M1 is being driven. The developer is conveyed by the member 63 and is supplied from the developer supply port 56 to the second developer pool P2 below the developing container 41. 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. Note that the high-density developer is supplied by the toner image density sensor SNd.
(A sensor for detecting the toner image density Ta, see FIG. 1) This is also performed when the toner image density Ta detected is equal to or less than the reference value Tao. Further, when the high-concentration developer is supplied and the ratio of the toner increases, and the height of the developer in the developing container 41 becomes a predetermined value or more, a developer upper limit height sensor disposed in the developing container 41. (See FIGS. 3B and 9) SNj detects.

Referring to FIG. 3B and FIGS.
Outside the first developer outlet 57 and the second developer outlet 58 (see FIGS. 3B, 6, and 7), a first discharge tube connecting portion 68a and a second discharge tube connecting portion 68b. Is disposed. The front end portion (the end on the X side) of the discharge developer transfer tube 69 is connected to the discharge developer transfer tube connection portion 68, and the rear end portion of the discharge developer transfer tube 69 is connected to a developer collection container. 71 (see FIG. 6). Inside the discharge developer transport cylinder 69, a discharge developer transport member 72 having a rotatable rotating shaft 72a and a transport blade 72b mounted on the outer peripheral portion of the rotary shaft 72a is arranged. A gear G5 (FIG. 6) is provided at the rear end of the rotating shaft 72a of the discharging developer conveying member 72.
And the developing device motor M1
The rotational force (see FIG. 9) is transmitted to the discharge developer conveying member 72 via the gear G5.

3A, 3B, 6 to 8, an L-shaped shutter support member is provided on the front and rear side surfaces of a first discharge tube connecting portion 68a arranged outside the first developer discharge port 57. 73 is rotatably supported. A closed position (two-dot chain line in FIG. 3B) or an open position (solid line in FIG. 3B) for closing the first developer outlet 57 is provided inside the first discharge tube connecting portion 68a of the shutter support member 73. The upper part of the shutter 74 that moves to the position () is fixed. The L-shaped shutter support member 7 extending rightward (-Y direction) from the front side surface (X side surface) of the first discharge cylinder connecting portion 68a.
The bent portion 3 is urged upward (Z direction) by a torsion coil spring 76, and the shutter 74 is moved upward by the bent portion of the L-shaped shutter support member 73 to move the shutter 74 to the opening position. It is configured to be held.

At the end of the bent portion of the shutter support member 73, a shutter opening / closing solenoid SLa disposed between the first discharge cylinder connecting portion 68a and the second discharge cylinder connecting portion 68b (Z Direction). When the output shaft of the shutter opening / closing solenoid SLa contracts, the bent portion of the shutter support member 73 is pulled downward (-Z direction), and the shutter 74 fixed to the shutter support member 73 is moved from the opening position. It is configured to move to the closed position. The shutter opening / closing solenoid SLa is driven by a shutter opening / closing solenoid drive circuit D2 controlled by the controller C. Incidentally, the reference numerals 73, 76, SLa, C, D2
The shutter operation device (73 + 76)
+ SLa + C + D2), and the first developer outlet opening / closing device (73-76 + SLa + C + D) is composed of the shutter 74 and the shutter operating device (73 + 76 + SLa + C + D2).
2) is configured.

In FIG. 9, the controller C has U
I (user interface) is connected and the UI
Is provided with a display unit UIa, a copy start button UIb, a copy setting number input key UIc, and the like. In addition to the copy start signal and the set number of copies input from the UI (user interface), the controller C includes the developer upper limit height sensor SNj, the in-container toner density sensor SNv, the toner image density sensor SNd, and the like. And other detection signals are input.

In response to the input signal, the controller C operates the supply clutch operating circuit Cr2d, the developing device motor driving circuit D1, the developing device clutch operating circuit Cr1d,
It outputs control signals for a shutter opening / closing solenoid drive circuit D2 and other operation circuits (not shown). The controller C for executing processing according to the various input signals
An I / O (input / output interface) for inputting / outputting an external signal and adjusting an input / output signal level, a ROM (read only memory) storing programs and data for performing necessary processing, Computer having a RAM (random access memory) for temporarily storing necessary data, a CPU (central processing unit) for performing input / output control, arithmetic processing, and the like according to a program stored in the ROM By executing the program stored in the ROM, various functions can be realized. That is, the controller C has the following functions. C1: Developer Replenishing Means The developer replenishing means C1 is provided when the toner concentration Tb in the container is lower than the reference value Tbo and when the toner image density Ta is lower than the reference value Ta
When it is lower than o, the clutch Cr2 is operated to supply the high-concentration developer by the supply developer conveying member 63.

C2: Copy Number Counter The copy number counter C2 is a counter that counts the number of copies from when the copy start button UIb of the UI (user interface) is pressed until the copy operation ends. C3: 10-sheet counter The 10-sheet counter C3 is used for every 10 continuous copies.
This is a counter used to form the patch (toner image for density detection) on the image carrier 16. FLi (i = 0, 1, 2,..., 9): replenishment presence / absence determination flag The replenishment presence / absence determination flag FL0 indicates that high-density developer is currently being supplied (the clutch Cr2 is operating). Is set to FL0 = "1", and FL0 is set when high-concentration developer is not supplied (the clutch Cr2 is not operated).
= A flag that stands for "0" and is a flag that is rewritten each time one second elapses. Replenishment presence / absence determination flag FLi (i =
0, 1, 2,..., 9), FLi + 1 =
This flag is rewritten to FLi. The replenishment flag FLi (i = 0, 1, 2,..., 9) is constituted by a shift register having 1 bit × 10 storage areas. That is, the value of FL0 is sequentially shifted to FL9 every one second. Therefore, the value of FL9 is 9
This is a value indicating the presence or absence of the replenishment operation two seconds ago. The developing device D according to the first embodiment is configured such that the high-concentration developer newly supplied into the developing container 41 is conveyed to the position of the first developer outlet 57 after a lapse of 9 seconds. When FL9 is "1", it means that the developer newly supplied into the developing container 41 has reached the first developer outlet 57.

C4: Over-developer-height detecting means for increasing toner ratio C4: Over-developer-height detecting means for increasing toner ratio
When the high-concentration developer is supplied while the first developer outlet 57 is closed, the developer in the developing container 41 rapidly increases when the toner ratio increases, and the second developer outlet 58 If the discharge of the developer cannot keep up and the height of the developer in the developing container 41 becomes a predetermined value or more, the state is detected.

C5: Shutter open / close control means The shutter open / close control means C5 reads the value of the replenishment presence / absence determination flag FL9,
If "1", an operation signal for moving the shutter 74 to the closing position is output, and if the replenishment flag FL9 = "0", an operation signal for moving the shutter 74 to the opening position is output. Output a signal. The reason why the opening / closing operation signal is output based on the replenishment presence / absence determination flag FL9 is that the high-concentration developer newly replenished in the developing container 41 reaches the first developer outlet 57 after 9 seconds. This is because the first developer outlet 57 is considered to be closed when passing through. In the first embodiment, the time required for the high-concentration developer to reach the first developer outlet 57 after the high-concentration developer is supplied into the developing container 41 is set to 9 seconds. It can be changed depending on the transport speed of the agent. The shutter opening / closing control means C5 outputs an operation signal for moving the shutter 74 to the opening position when FL9 is "1", and the developer height over state detecting means C4 when the toner ratio is increased. An operation signal for moving the shutter 74 to the opening position is output in response to the detection signal.

For example, if the replenishment of the developer lasts for about 10 seconds, FL0 becomes "1" about 10 times continuously. Nine seconds after this, FL9 becomes "1" continuously about ten times, and the shutter 74 is closed continuously for about ten seconds. Therefore, the shutter 74 is opened and closed according to the developer supply amount. Since the replenishing amount of the developer increases and decreases according to the increase and decrease of the charge amount of the developer, it is a developer amount increase / decrease parameter. Therefore, the shutter 74 that opens and closes according to the developer supply amount is opened and closed according to the developer amount increase / decrease parameter.

(Operation of Embodiment 1) In FIG. 1, 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. In FIG.
The first transport member R1 disposed in the first developer pool P1 of the developing container 41 stirs while transporting the developer in the axial direction of the developing roll R0. A second developer reservoir P2 provided below the first developer reservoir P1 and a second developer reservoir P2 disposed below the first developer reservoir P2.
The transport member R2 stirs while transporting the developer in a direction opposite to that of the first transport member R3. The developer transported to the developing area Q2 is consumed by the developing operation.

The deteriorated developer is supplied to a first developer outlet 57 provided on the outer wall of the upper cylindrical portion 43a of the front connection member 43.
Is discharged from The developer not discharged from the first developer discharge port 57 is provided between the first developer discharge port 57 and the second developer discharge port 58 in the upper cylindrical portion 43 a of the front connection member 43. The accumulated developer remains in the upstream portion of the partition wall 53, and the accumulated developer is provided on the first connection port formed on the upstream side of the partition wall 53 in the developer transport direction and on the downstream side of the first developer discharge port 57. From 43c, it falls into the second developer sub-pool 51 (second developer pool P2) below the first developer sub-pool 48.

The second developer pool P in the developing container 41
The second transport member R2 accommodated in the second connecting member 4
The high-concentration developer supplied from the developer supply port 56 provided in the upper cylindrical portion 43a of the third container 43 is stirred and transported to the lower cylindrical member 44b at the rear end of the developing container 41. The developer in the lower cylindrical member 44b of the rear connection member 44 is pushed upward by the pressure of the developer conveyed by the second conveyance member R2, and is connected through the third connection port 44c to the rear connection. The developer is conveyed to a first main developer pool 47 (first developer pool P1) in the upper cylindrical portion 44a of the member 44.

In FIG. 3C, in the first developer pool P1, the first transport member R1 agitates and transports the developer in a direction opposite to the transport direction of the second transport member R2.
At this time, a homogeneous two-component developer triboelectrically charged by the mixing action of the toner and the carrier is obtained. The uniformly mixed two-component developer is adsorbed in layers on the surface of the developing roll R0 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 54. 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 step, the developer remaining on the developing roll R0 is peeled off from the surface of the developing roll R0 (that is, the developing sleeve R0b),
It is stirred and transported again.

In FIG. 1, a recording sheet S on which a toner image is to be transferred is taken out from the paper feed trays T0 to T5, is conveyed, is temporarily stopped by a registration gate 23, and is temporarily stopped by a registration roller 24 at a predetermined timing. The sheet is conveyed to a transfer position Q3 between the carrier 16 and the transfer device 19. Transfer position Q3
In the above, the toner image on the image carrier 16 is transferred onto the recording sheet S by the transfer device 19. Then, the recording sheet S to which the toner image has been transferred is heated and fixed by the fixing device F, and is discharged to the sheet discharge tray TR. After the transfer of the toner image, the toner remaining on the surface of the image carrier 16 is scraped off by the cleaner unit 20.

As the temperature and humidity around the image forming apparatus U decrease, the charge amount of the toner increases, and the density of the toner decreases. (Developer Supply Operation Control Flow) FIG. 10 is a developer supply operation control flow of the developing device of the first embodiment. The process shown in FIG. 10 starts at the same time when the power of the image forming apparatus is turned on. In ST1 (step 1) of FIG. 10, it is determined whether the copy start switch has been turned on. If no (N), ST1 is repeatedly executed. If yes (Y) in ST1, the process moves to ST2.

In ST2, a toner image for density detection is developed on the image carrier 16, and the developed toner density (density of the developed toner image) Ta is used as the toner image density sensor SNd.
(See FIG. 1). Next, in ST3, 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 ST3, the process moves to ST4. After the high-density developer is supplied in ST4, the process returns to ST2.

If the answer is yes (Y) in ST3, the operation moves to ST5. In ST5, 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 developing container when the detected value Ta of the toner image density is equal to or larger than the set reference value Tao, the detected value Tb is used as the toner concentration reference value in the container. Set to Tbo. Next, in ST6, the count value of the ten-sheet counter n is set to “0”. That is, n = 0. Next, in ST7, Tb
It is determined whether or not ≧ Tbo. Since Tb = Tbo was set in ST5, the result is initially yes (Y). If yes (Y), copy is performed in ST8. If no (N), toner is supplied at the same time as copying is performed in ST9.

Next, in ST10, the count value of the ten-sheet counter n is incremented by "1". In ST11, it is determined whether or not copying has been completed. If no (N), the process moves to ST12. In ST12, it is determined whether or not n = “10”. If no (N), the process moves to ST13. After detecting the toner concentration Tb in the container in ST13, the process returns to ST7. In the case of YES (Y) in ST12, it means that 10 copies have been made, and the process returns to ST2. ST1
In 1, in the case of yes (Y), the process proceeds to ST1.

(Developer replenishment flag setting flow) FIG. 1
1 is a flowchart for setting a developer replenishment flag for the developing device of the first embodiment. The processing shown in FIG. 11 is executed by multitasking in parallel with the processing of FIG. 10 and other processing at the same time when the power of the image processing apparatus including the developing device of the first embodiment is turned on. In ST21 of FIG. 11, it is determined whether the copy start switch has been turned on. No (N)
In the case of, step ST21 is repeatedly executed. ST
If yes (Y) in 21, the process moves to ST22. ST
At 22, the detection of the presence or absence of supply is started. In ST23, the measurement time t of the elapsed time measurement timer is set to t = 0. ST
At 24, it is determined whether one second has elapsed. If no (N), ST24 is repeatedly executed, and if yes (Y), the process moves to ST25.

In ST25, the measurement time t of the elapsed time measurement timer is set to t = 0. In ST26, change the value of FLi to FLi
Move to +1. In ST27, it is determined whether or not the high-concentration developer is being supplied. If no (N), the process moves to ST28, and if yes (Y), the process moves to ST29. In ST28, the developer replenishment flag FL0 = 0 (when high-density developer is not being replenished). In ST29, the developer replenishment flag FL0
= 1 (when high-concentration developer is being supplied). In ST30, it is determined whether or not the job has been completed, that is, whether or not the copy operation has been completed. If no (N), the process returns to ST24; if yes (Y), the process returns to ST21.

(Shutter Open / Close Control Flow) FIG. 12 is a shutter open / close control flow of the developing device of the first embodiment. The processing shown in FIG. 12 is performed at the same time when the power of the image processing apparatus including the developing device of the first embodiment is turned on, and the processing shown in FIGS.
Is executed in multitasking in parallel with the processing of and other processing. In ST41 of FIG. 12, it is determined whether the copy start switch has been turned on. If no (N), step ST41 is repeatedly executed. If the answer is yes (Y) in ST41, the process moves to ST42. In ST42, the value of the developer supply presence / absence determination flag FL9 set in the flow shown in FIG. 11 is read. In ST43, it is determined whether or not the developer replenishment flag FL9 is "1", that is, whether or not the high-density developer has been replenished 9 seconds before. If yes (Y), the process moves to ST44.

In step ST44, the shutter 74 is moved to the closed position and held in the closed position, and the first developer outlet 57 is closed. After this operation, the developer is not discharged from the first developer discharge port 57, and the amount of the developer is increased and stored in the upstream portion of the partition wall 52. Therefore, the replenished developer is not immediately discharged. Therefore, it is possible to prevent the developer carrier from being wastefully discharged from the developing container 41. When the amount of the developer remaining in the upstream portion of the partition wall 52 exceeds a predetermined amount, the developer passes over the partition wall 52. The image material having passed over the partition wall 52 is stored downstream of the partition wall 52, and when the height of the upper surface of the stored developer exceeds the lower edge of the second developer outlet 58, the developer exceeding the lower edge is removed. Is discharged from the second developer discharge port 58. The developer not discharged from the second developer discharge port 58 is supplied to the developer supply device (61).
-62 + G4 + Cr2 + Cr2d + C), along with the developer supplied to the first developer sub-pool 49, falls from the second connection port 43d to the second developer sub-pool 51, circulates, and circulates again. It is transported to the pool P1.

Next, in ST45, it is determined whether or not the developer height in the developing container 41 is equal to or more than a predetermined value. If no (N), the process moves to ST46. In ST46, it is determined whether or not the job has ended. If no (N), the process returns to ST42. If yes (Y), the process moves to ST47. In step ST47, the shutter 74 is moved to the open position and held at the open position, and the first developer outlet 57 is opened. That is, the developing container 4
The control is performed so that the developer height in 1 is not less than a predetermined value.
After the operation of ST47 is completed, the process returns to ST41.

When ST43 is NO (N), that is, when the developer supply presence / absence determination flag FL9 is "0" (when high-density developer was not supplied 9 seconds before),
If the answer is YES (Y) (when the height of the developer in the developing container 41 is equal to or less than a predetermined value), the process proceeds to ST48. In ST48, the shutter 74 is moved to the opening position and held at the opening position, and the process proceeds to ST49. In ST49, it is determined whether or not the job has ended. If no (N), the process returns to ST42. If yes (Y), the process returns to ST41.

(Embodiment 2) FIG. 13 is a block diagram showing Embodiment 2 of the present invention, and corresponds to FIG. 9 of Embodiment 1 described above. 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. Example 2
Is different from the first embodiment in the following points, but is configured similarly to the first embodiment in other points.

In FIG. 13, the controller C of the image forming apparatus U including the developing device D of the second embodiment includes a temperature sensor SNo and a humidity sensor SNw for detecting the temperature and humidity around the image forming apparatus U. A detection signal is input. The controller C of the second embodiment has the following functions and other functions. C4: Developer height over state detecting means when toner ratio is increased. Developer height over state detecting means C4 when toner ratio is increased.
When the high-concentration developer is supplied while the first developer outlet 57 is closed, the developer in the developing container 41 rapidly increases when the toner ratio increases, and the second developer outlet 58 If the discharge of the developer cannot keep up and the height of the developer in the developing container 41 becomes a predetermined value or more, the state is detected. C5 ': Shutter opening / closing control means The shutter opening / closing control means C5' detects a temperature / humidity set value or less state in which the temperature and humidity are below the set value by a temperature / humidity set value or less state detecting means C6 described later. Then, after outputting an operation signal for moving the shutter 74 to the closing position, an operation signal for moving the shutter 74 to the opening position is output at predetermined intervals. The shutter opening / closing control means C5 'outputs an operation signal for moving the shutter 74 to the opening position when a state below the temperature / humidity set value is detected, and the developer height over state detecting means when the toner ratio is increased. An operation signal for moving the shutter 74 to the opening position is output according to the detection signal of C4.

C6: Temperature and Humidity Set Value or Less State Detecting Means The temperature and humidity set value or less state detecting means C6 detects a temperature and humidity set value or less state where the temperature and humidity are below the set values. In the second embodiment, the temperature and humidity are used as charge amount increase / decrease parameters that change in relation to the charge amount of the toner.

FIG. 14 is a flowchart for controlling the opening and closing of the shutter according to the second embodiment. The processing shown in FIG. 14 is executed at the same time when the power of the image processing apparatus including the developing device of the second embodiment is turned on. In ST51 of FIG. 12, it is determined whether the copy start switch has been turned on. If no (N), step ST51 is repeatedly executed. In the case of YES (Y) in ST51, the process moves to ST52. In ST52, temperature and humidity are detected. In ST53, it is determined whether the temperature and humidity are equal to or less than a set value. If no (N), the process returns to ST51. If yes (Y), the process moves to ST54.

In ST54, the shutter 74 is moved to the open / close position to close the first developer outlet 57. After this operation, the developer is not discharged from the first developer discharge port 57, and the amount of the developer is increased and stored in the upstream portion of the partition wall 52. Therefore, the replenished developer is not immediately discharged. Therefore, it is possible to prevent the replenished carrier of the developer from being wastefully discharged from the developing container 41. When the height of the upper surface of the stored developer exceeds the lower edge of the second developer outlet 58, the developer exceeding the lower edge is discharged from the second developer outlet 58. In ST55, a closing timer for measuring the time during which the shutter 74 closes the first developer outlet 57 is set. In ST56, it is determined whether or not a predetermined time has elapsed in the closing timer. If no (N), the process moves to ST57. In ST57, it is determined whether the developer height is equal to or more than a predetermined value.
If no (N), the process moves to ST58. In ST58, it is determined whether or not the job has ended. If no (N), the above ST56
Returns to ST59 in the case of Yes (Y). In ST59, the shutter 74 is moved to the opening position, and the first
The developer outlet 57 is opened, and the process returns to ST51.

If the answer is YES (Y) in ST56 and ST56, the process moves to ST60. In ST60, the shutter 74 is moved to the opening position, and the first developer discharging port 5 is moved.
7 is opened. In ST61, the shutter 74 is set to the first
An open timer for measuring the time for which the developer outlet 57 opens is set. In ST62, it is determined whether the open timer has passed a predetermined time. If yes (Y), the process moves to ST63.

In ST63, it is determined whether the job has been completed. If no (N), that is, copying is in progress,
If the high-concentration developer is being supplied because the temperature and humidity are equal to or lower than the set values, the process returns to ST64 to move the shutter 74 to the closing position. If yes (Y), that is, if the copying is completed, the process returns to ST51. If the answer is NO (N) in ST62, that is, if the open timer has not passed the predetermined time, the process proceeds to ST64. In ST64, it is determined whether or not the job has been completed. If no (N), the process returns to ST62, and if yes (Y), the process returns to ST51.

(Embodiment 3) FIG. 15 is an enlarged explanatory view of a main part of a developing device according to Embodiment 3 of the present invention. FIG. 16 is an explanatory view of the developing container provided in the developing device of the third embodiment of the present invention. FIG. 16A is a perspective view of the developing container provided in the developing device of the third embodiment of the present invention. FIG. 12 is an enlarged explanatory view of a developer discharge port of a developing container provided in the developing device of Example 3; FIG. 17 is a plan sectional view of the developing container provided in the developing device of the third embodiment. FIG. 18 is a block diagram of a developing device according to the third embodiment. In the description of the third embodiment,
The same reference numerals are given to the components corresponding to the components of the first embodiment, and the detailed description thereof will be omitted.

The third embodiment is different from the first embodiment in the following points.
Although it is different from the first embodiment, the other points are the same as those of the first embodiment. In FIG. 15 to FIG.
The second developer pool P2, which is the second developer stirring area of the developing container 41, is disposed adjacent to the first developer pool P1, which is the first developer stirring area, on the side opposite to the developing roll R0. Have been. Further, the rear connection member 44 of the rear end portion (the end portion on the −X side) of the developing container 41 of the first embodiment is omitted, and the staying member disposed between the developing roll R0 and the second transport member R2 is omitted. The developer transport member R3 is also omitted.

In the third embodiment, as in the first embodiment, the shutter opening / closing control means C5, which is a function of the controller C, reads the value of the replenishment flag FL9.
When the replenishment flag FL9 is "1", an operation signal for moving the shutter 74 to the closed position is output. When the replenishment flag FL9 is "0", the shutter 74 is opened. An actuation signal for moving to the position is output. By outputting an operation signal for moving the shutter 74 to the closing position, the shutter 74 moves to the closing position, and the first developer outlet 57 is closed. Therefore, in order to keep the toner image density constant,
When a new developer is supplied into the printer, the supplied developer is not immediately discharged. Therefore, it is possible to prevent the developer carrier from being wastefully discharged from the developing container 41. After the first developer outlet 57 is closed, the developer in the developer container 41 passes over the partition 52 on the downstream side of the first developer outlet 57 in the developer conveying direction, and is located on the downstream side of the partition 52. Of the second developer outlet 58
Store on the side. The developer is discharged from the second developer outlet 58 after being stored until the developer rises to the height of the developer that can be discharged from the second developer outlet 58.

(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 third embodiment, the temperature / humidity around the image forming apparatus U can be adopted as the developer amount increase / decrease parameter instead of the replenishment amount of the high density developer as the developer amount increase / decrease parameter.

[0081]

The above-described developing device of the present invention has the following effects. (E01) Even when a large amount of new developer is replenished due to an increase in the charging performance of the two-component developer, the carrier of the replenished new developer can be prevented from being discharged in an unused state.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an entire image forming apparatus including a developing device according to a first embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of a main part of FIG. 1;

3 is an explanatory view of a developing container of the developing device according to the first embodiment of the present invention. FIG. 3A is a cross-sectional view taken along line IIIA-IIIA of FIG.
3B is a sectional view taken along the line IIIB-IIIB of FIG. 7, and FIG. 3C is a sectional view of FIG.
It is a IIIC-IIIC sectional view.

FIG. 4 is an explanatory diagram of a gear of a developing container.

FIG. 5 is a sectional view taken along line VV of FIG. 3C.

FIG. 6 is a perspective view of a developing container.

FIG. 7 is an enlarged explanatory view around a developer discharge port of the developing container, and is a view as seen from a direction of an arrow VII in FIG. 2;

FIG. 8 is a schematic explanatory view of a first developer outlet opening / closing device.

FIG. 9 is a block diagram of a developing device according to the first embodiment.

FIG. 10 is a control flow of the developer supply operation of the developing device of the first embodiment.

FIG. 11 is a flowchart for setting a developer replenishment flag for the developing device of the first embodiment.

FIG. 12 is a shutter open / close control flow of the developing device of the first embodiment.

FIG. 13 is a block diagram showing a second embodiment of the present invention, and corresponds to FIG. 9 of the first embodiment.

FIG. 14 is a shutter opening / closing control flow according to the second embodiment.

FIG. 15 is an enlarged explanatory view of a main part of a developing device according to a third embodiment of the present invention.

FIG. 16 is an explanatory view of a developing container provided in a developing device according to a third embodiment of the present invention. FIG. 16A is a perspective view of the developing container provided in the developing device of the third embodiment of the present invention. 16
B is an enlarged explanatory view of a developer discharge port of a developing container provided in the developing device according to the third embodiment of the present invention.

FIG. 17 is a plan cross-sectional view of a developing container provided in the developing device according to the third embodiment.

FIG. 18 is a block diagram of a developing device according to a third embodiment.

[Explanation of symbols]

P1: first developer stirring area; P2: second developer stirring area;
Q2: developing area, R0: developing roll, R1: first conveying member, R2: second conveying member, R3: staying developer conveying member 41: developing container, 43c: first connection port, 43d: second connection port, 46: developing roll accommodating section, 47: first developer main stirring area, 48, 48: first developer sub stirring area, 51, 51
... Second developer sub-stirring area, 52 ... Partition wall, 53 ... Partition wall,
57: first developer outlet, 58: second developer outlet, 7
4 shutter, (C5; C5 ') shutter opening / closing control means, (43c, 43d, 44c) connection port, (52; 5)
2 ';64;64') ... developer outlet, (61 to 62+
G4 + Cr2 + Cr2d + C) ... developer supply device, (73 + 7)
6 + SLa + C + D2) ... Shutter actuator, (73-7)
6 + SLa + C + D2)... First developer outlet opening / closing device.

Claims (2)

[Claims] 1. A developing device having the following requirements, (A01) a developing roll for transporting a two-component developer composed of a toner and a carrier to a developing area, and (A02) containing the developing roll. A developing roll accommodating portion, a first developer agitating region extending in the axial direction of the developing roll adjacent to the developing roll accommodating portion, and both ends in the axial direction disposed adjacent to and below the first developer agitating region. A container excluding the connection port is partitioned by the partition wall from the first developer stirring region, and both ends in the axial direction are connected to the first developer stirring region and extend along the partition wall and the partition wall. A developing container having a second developer stirring area formed between the developing roller and an outer wall; (A03) a first developer main stirring area formed at a position adjacent to the developing roll and the shaft extending from an end of the developing roll; First extending outward in the direction A first developer stirring area provided with a developer sub-stirring area, and a first developer stirring area formed according to a first developer main stirring area and a first developer sub-stirring area of the first developer stirring area, respectively. (A04) an upstream side of the second developer sub-stirring area in the developer conveying direction, the developing container including: a second developer main stirring area and a second developer stirring area provided with a second developer sub-stirring area; A developer replenishing device for replenishing new developer at the end or at the downstream end of the first developer sub-stirring area in the developer transport direction; (A06) a second transport member disposed in the second developer agitating region and agitating while transporting the two-component developer in a direction opposite to the first transport member; , (A
07) a first developer outlet provided in a downstream portion of the outer wall of the container forming the first developer stirring area; (A08) an outer wall of the container forming the first developer sub-stirring area and the first developer outlet;
A second developer outlet formed downstream of the developer outlet, and (A09) a first developer outlet in the developing container and a second developer outlet.
(A010) a partition provided between the first developer outlet and the second developer outlet when the first developer outlet is stored in a predetermined amount or more; A first connection port formed on the upstream side of the partition in the developer transport direction and downstream of the first developer discharge port to connect the first developer stirring area and the second developer stirring area; (A011) the first connection port formed downstream of the second developer discharge port and having a second connection port connecting the first developer stirring area and the second developer stirring area; A first developer discharging device having a shutter that moves between an opening position that opens the developer discharging opening and a closing position that closes the developer opening and closing the first developer discharging opening, and a shutter operating device that opens and closes the shutter; Outlet opening / closing device, (A012) Shutter opening and closing control means for outputting a closing operation signal of the shutter in accordance with the detected value of the agent increase and decrease parameters. 2. A developing device characterized by the following requirements: (B01) a developing roll for transporting a two-component developer comprising a toner and a carrier to a developing area; and (B02) containing the developing roll. A developing roll accommodating portion, a first developer agitating region extending in the axial direction of the developing roll adjacent to the developing roll accommodating portion, and being disposed adjacent to the first developer agitating region on an opposite side to the developing roll. A portion excluding the connection ports at both ends in the axial direction is partitioned from the first developer stirring region by a partition wall, and both ends in the axial direction are connected to the first developer stirring region and the partition wall and the partition wall thereof (B03) a first developer main stirring area formed at a position adjacent to the developing roll and a second developer stirring area formed between the developing roll and the outer wall of the container extending along From the end A first developer sub-stirring region provided with a first developer sub-stirring region extending outward and a first developer main stirring region and a first developer sub-stirring region of the first developer stirring region; A second developer main stirring area and a second developer sub-stirring area formed in response to the second stirring.
(B04) a first transporting member disposed in the first developer agitating area and agitating while transporting the two-component developer in the axial direction of the developing roll;
05) a second transport member disposed in the second developer agitating region and agitating while transporting the two-component developer in a direction opposite to the first transport member; (B06) forming the first developer agitating region; A first developer discharge port provided at a downstream portion of the container outer wall, and (B07) a first developer discharge port formed at the container outer wall forming the first developer sub-stirring area and downstream of the first developer discharge port. (B08) a developer replenishing device for replenishing new developer to a second developer sub-stirring area downstream of the second developer outlet in the developer transport direction; (B09) inside the developing container Is provided between the first developer outlet and the second developer outlet, and when the developer on the first developer outlet side is stored in a predetermined amount or more, the developer gets over the second developer outlet side. (B010) The upstream side of the partition in the developer transport direction and the first partition A first connection port formed downstream of the developer discharge port to connect the first developer stirring area and the second developer stirring area; and a first connection port formed downstream of the second developer discharge port. The first developer stirring area and the second developer stirring area;
(B011) moving between an opening position for opening the first developer discharge port and a closing position for closing the first developing device, the connection port having a second connection port for connecting to the developer stirring area; A first developer outlet opening / closing device having a shutter for opening and closing the developer outlet and a shutter actuating device for opening and closing the shutter, and (B012) detecting a developer amount increasing / decreasing parameter affecting the developer amount increase / decrease parameter. Shutter opening / closing control means for outputting the shutter opening / closing operation signal for opening / closing the shutter in response to the signal