JPH01315780A - Dry developing device of image forming device - Google Patents

Abstract

PURPOSE:To always stably supply developer to the side of a developing device main body by preventing shortage of developer in the developer containing part of the side of the developing device main body, in the developing device having two developer containing parts. CONSTITUTION:From a first toner container 8, toner is replenished by a toner replenishing roller 10 to a developing tank 2. Here, the optical density of a toner image of a test pattern formed on a photosensitive body 6 is detected by a image density detecting element 12 consisting of a photosensor, etc. As a result, when the toner concentration is judged to be lower than a reference concentration, the toner replenishing roller 10 is driven by an outside driving device, whereby toner is replenished in the developing tank 2. These process are repeated until the toner concentration come to be a fixed concentration. Thus, toner concentration in developer is maintained within a fixed range.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry developing device used in an image forming apparatus such as a copying machine.

Director Josue1Recently, image forming devices such as copying machines are being made smaller, more multi-functional, and more color-oriented. There is a tendency for various process equipment to be arranged around the carrier in a very crowded manner.

In image forming devices such as color copying machines, multiple relatively bulky developing devices must be arranged around the photoreceptor, and the developing devices are required to be more compact. and add developer as needed.
! The developer storage section for replenishing the image device main body is also made to have a smaller capacity.

If the developer storage section is connected to the main body of the developing device and the developer is supplied from there to the main body of the development device, and if the developer storage section is of a small capacity, the developer in this storage section will quickly become empty. Therefore, the frequency of supplying the developer to the i-image side storage section increases, which is undesirable. Therefore, two such developer storage sections are provided, one of which is installed in a location with relatively sufficient space away from the main body of the developing device, and it has a large capacity, and the developer is transported from there. A configuration has been proposed in which the developer is transported to the other developer storage section by a developer transporting and replenishing means such as a screw, and from there the developer is sent toward the main body of the developing device. In this way, advantages such as being able to increase the total storage amount of developer can be obtained.

By the way, in such a developing device, for example, even if the amount of developer in the developer storage section on the developing device side becomes less than the set amount and the developer conveying and replenishing means is activated, the amount of developer does not reach the set amount. If it does not return, it is determined that there is no more developer in the developer storage section located away from the main body of the developing device, a developer end signal is generated, and this fact is displayed on the operation panel or the like.

Upon seeing this display, the operator of the image forming apparatus opens the panel door, etc., and replenishes developer into the large-capacity developer storage section located away from the main body of the developing apparatus. In other words, immediately after the developer end signal is generated, a copying machine may want to make an emergency copy.

Now, if such copying is performed for a predetermined number of sheets, the amount of developer in the developer storage portion on the developing device main body side will be reduced by the amount of developer corresponding to the number of copies. Since the developer storage section is made with a relatively small capacity, when the number of copies mentioned above increases, the amount of developer remaining becomes small, and the next time you make a regular copy, you will need to use the developer. If the developer is not transported in time from the developer storage section located away from the main body of the device to the developer storage section on the side of the main body of the development device, there will be insufficient supply of developer to the main body of the development device, resulting in a decrease in image density. As a result, image quality deteriorates.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dry developing device for an image forming apparatus that solves these problems.

In order to achieve the above object, the present invention relates to a dry developing device of an image forming apparatus according to the present invention, and includes a developer carrying member that carries a developer for developing a static latent image on its peripheral surface, and a developer carrying member. The first housing contains the developer to be supplied to the
a second developer storage section that stores developer for replenishment; and a developer that transports and replenishes developer from the second developer storage section to the first developer storage section. When it is detected that the amount of developer in the developer transporting and replenishing means and the first developer storage section is less than a set amount, the developer transporting and replenishing means is activated, and
A developer amount detecting means for generating a developer end signal when it is detected that the amount of developer does not reach a set amount regardless of the operation of the developer conveying and replenishing means; with the drug supplemented.

A means for canceling the output of the developer end signal; and means for energizing the developer conveyance and replenishment means so that the developer is conveyed from the second developer storage section to the first developer storage section before image formation. It is characterized by this.

Further, in the present invention, in the above configuration, the amount of developer transported from the second developer storage section to the first developer storage section is adjusted after the developer end signal is output and before the output of the signal is canceled. We propose a configuration in which the amount of developer is equal to or greater than the amount of developer required for the image formation performed.

Furthermore, in the above configuration, the present invention provides a second developer storage section such that the amount of developer in the first developer storage section is equal to the set amount.
We propose a configuration in which the amount of developer to be conveyed from the first developer storage section to the first developer storage section is set.

The present invention will be explained below based on one embodiment.

FIG. 1 shows a dry developing device according to an embodiment of the present invention.

In the figure, a two-component developer (not shown) containing a carrier in addition to toner is contained in a developing tank 2 of a developing device main body 1. The contained developer is drawn up by the stirring roller 3 and supplied to the circumferential surface of the developing roller 5, which has a magnet 4 provided therein.

The developer is carried on the circumferential surface of the developing roller 5 that has been supplied with the developer, and a magnetic brush is formed by the developer. This magnetic brush rotates in the direction of the arrow by the rotation of the developing roller 5 or the magnet 4 or 5, and this rotating magnetic brush contacts the drum-shaped photoreceptor 6 and transfers toner in the developer onto the photoreceptor 6. An electrostatic latent image is developed. The developing roller 5 constitutes an example of a developer carrying member that carries a developer on its circumferential surface for developing such an electrostatic latent image.

Incidentally, when the magnetic brush passes through the doctor blade section 7, excess developer is scraped off by the doctor blade section 7, and the brush height is set to be suitable for development. The scraped developer passes through a horizontal stirring member 11 that stirs the developer in the axial direction of the developing roller 5, and is led to the stirring roller 3 again.

A first developer storage section 8 is connected to the developer tank 2 and stores a developer to be supplied to the development roller 5 therein. In this embodiment, as mentioned earlier, a two-component developer of carrier and toner is used, and the first
The developer storage section 8 stores toner therein. Further, the first developer storage section 8 is configured as a container in this embodiment. Therefore, in accordance with this embodiment, the first developer storage section will hereinafter be referred to as the first toner storage container.

From the first toner storage container 8, toner is delivered into the developing tank 2 by a toner supply roller 10.

Here, the reference numeral 12 denotes an image density detection element such as a photosensor, which detects the optical density of the toner image of the test pattern formed on the photoreceptor 6. This detection result is compared with a reference density level, and it is determined whether or not the current toner density in the developer is low.

When it is determined that the toner density is lower than the reference density, the toner replenishing roller 10 is moved by an external driving means, which will be described later.
will be replenished within. This is done until the toner 1 degree reaches a certain 1 degree level. In this way, the toner concentration in the developer is always maintained within a certain range.

A toner amount detection sensor '13 is provided in the wall of the eleventh toner storage container 8 by hollowing it out. As this 1-toner amount detection sensor 13, for example, a piezoelectric element sensor is used. This piezoelectric element sensor is made of a piezoelectric element such as crystal or ceramic, and when a voltage is applied to it, it vibrates at a specific frequency, and the amount of toner can be detected using this principle.

That is, when the pressure of powder such as toner is applied to the oscillating piezoelectric element sensor, the oscillation stops.

When the pressure is released, it begins to oscillate again, and this is used as an output signal to detect the presence or absence of toner.

Now, when such a sensor is used as the toner amount detection sensor 13, if the +-toner amount is at or above the level of the sensor 13, the oscillation will stop due to the pressure of that toner, and the amount will decrease below that level. If it does, the pressure will be released and it will oscillate again. Therefore, the amount of toner in the 1-toner storage container 8 can be detected using such a sensor.

Here, what is indicated by the reference numeral 9 is a second developer storage section that stores developer for replenishment. In this example, the second
Toner is stored in the developer storage section 9, which is also configured as a container.

Therefore, in accordance with this embodiment, the second developer storage section will be referred to as the 21st developer storage container.

FIG. 2 is a sectional view taken along line X--X in FIG. 1.

The second toner storage container 9 is connected to the first toner storage container 8 via a pipe 14 and is separated from the developing device main body 1 side. This arrangement allows the second toner storage container 9 to have a relatively large capacity.

Across both the first and second toner storage containers 8 and 9,
A toner conveying and replenishing screw 15 is provided, which is an example of a developer conveying and replenishing means for conveying and replenishing toner from the latter container to the former container.

The toner transport replenishment screw 15 is driven by the motor 16 via gears 17, 18.

A stirring agitator 20 is provided within the container 9 and is driven via a gear 19 meshing with a gear 18 . on the other hand,
The l/ner replenishing roller 10 is driven by an external driving source via gears 21 and 22.

Here, in FIGS. 1 and 2, as the toner in the first toner storage container 8 is sent into the developing tank 2, the amount of toner in the container 8 gradually decreases. Now, the amount of I/toner that is up to the toner amount detection sensor 13 is
Assuming that the amount is a predetermined set amount, when the amount of toner becomes less than this set amount, if the sensor 13 is a piezoelectric sensor as described above, it will start to oscillate again.

Here, for convenience, such a case is hereinafter referred to as the sensor 13 being turned off. On the other hand,! - If the amount of toner is equal to or greater than the set amount, the sensor 13 has stopped oscillating. Hereinafter, such a case will be referred to as the sensor 13 being turned on.

When the sensor 13 turns off, the motor 16 starts rotating (hereinafter this will be referred to as the motor turning on).
Accordingly, the toner conveying and replenishing screw 15 rotates via the gears 17 and 18, and the toner in the second toner storage container 9 is fed into the first toner storage container 8 through the pipe 14.

In this embodiment, the amount of toner conveyed per unit time by the toner conveying and replenishing screw 15 is set to be larger than the amount of toner replenishing per unit time to the developing tank 2 by the toner replenishing roller 10. In other words, the amount of toner transported by the l/toner transport replenishment screw 15 is set to be greater than the maximum amount of toner consumed on the developing device main body 1 side. This means that if the document continues to consume the most toner due to the large number of character image areas, if the conveyance amount and the 1-toner replenishment amount are set to the same amount, the first toner storage container 8 This is because a predetermined amount of toner becomes irresistible.

As the toner conveying and replenishing screw 15 continues to rotate, the amount of toner in the eleventh toner storage containers 8 gradually increases. When the level of the sensor 13 reaches a set amount, the sensor 13 is turned on and the motor 16 is turned off. Therefore, the supply of toner to the first toner storage container 8 is interrupted.

As mentioned earlier, when the toner amount detection sensor 13 is turned off, that is, when it detects that the amount of toner is low, the five motors 16 start rotating. 13 does not detect an increase in toner, that is, !・Gner conveyance supply screw 15
If the amount of toner does not reach the set amount regardless of the rotational operation of It is displayed on etc.

For example, the toner end display may be blinked. This display allows the operator to
Fill with toner.

According to such a configuration, there is no need to take the trouble to provide a toner end detection means in the second toner storage container 9.
This type of detection cost can be reduced.

Incidentally, in image forming apparatuses such as copying machines, a panel door that is opened and closed during maintenance and inspection is provided on the outer surface of the apparatus main body. Store the toner in the second toner storage container 9.
When such a panel door is opened, toner is filled into the second toner storage container 9, and the panel door is closed, the output of the 1-num end signal is canceled and the toner end display flashes. It is supposed to disappear (
Figure 5).

By the way, in FIG. 4, the remaining amount of toner in the first toner storage capacity 8 at the time when the toner end signal is generated is indicated by diagonal lines, which is a certain amount less than the A level at which the sensor 13 is turned off. It is B level.

Here, in FIG. 5, the sensor 13 is turned off at, for example, T-work, and the motor 16 starts to be turned on.

Even if the timer I detects that one hour has elapsed, if the toner does not reach the A level, a toner end signal is generated. That is, in one example, sensor 13
When timer I detects that the amount of developer in the first developer storage section has become less than the set amount, it operates the developer conveying and replenishing means, and also operates the developer conveying and replenishing means regardless of the operation of the developer conveying and replenishing means. A developer amount detection means is configured to generate a developer end signal when it is detected that the developer amount does not reach a set amount.

In Fig. 4, the remaining amount of 1 to ner at A level is Gf
ll (Durham), and the remaining amount of toner at B level as Gend (Durham), (Gfull-Gen
The amount of difference in step d) is calculated from the time when the above-mentioned timer ■ starts turning on, until the set time elapses, it is determined that the toner has run out, and a toner end signal is generated. This is the amount of toner that has been reduced by being sent within 2. On the other hand, at this point, naturally, the toner in the second toner storage container 9 is gone.

By the way, after the toner end signal occurs.

Before filling the second toner storage container 9 with toner, there may be cases where it is desired to urgently perform image formation, for example, in the case of a copying machine, copying.

Therefore, when such copying is executed, development is performed and toner is replenished to the tank 2, so that the toner in the first toner storage container 8 decreases to a level below the B level. Become.

Assume that the C level is a transitional level where when the top surface of the toner falls below this level, the amount of toner supplied to the developing tank 2 decreases and the image density tends to decrease to some extent, and the D level , if below this level,
It is assumed that the image density is extremely low and is at a critical level that makes it difficult to provide as a copy image.

When an emergency copy is executed and the number of copies increases, the toner level in the first toner storage container 8 after the execution becomes a level significantly lower than the B level.

In such a situation, after executing the emergency copy, open the panel door described above, fill the second toner storage container 9, which is empty of toner, with toner, close the panel door, and then start normal image formation (copying). ), if the toner level in the first toner storage container 8 in FIG. 4 is considerably lower than the B level, the supply amount of 1-toner will be insufficient and the image density will decrease. becomes. In particular, if the level falls further below the D level, the amount of toner replenishment will be extremely insufficient and the density of one image will drop significantly.

Furthermore, even if the level is around C, if toner is not replenished in time and regular copying is continued until the level drops below D, the image density will be significantly lower when the level is below D. This results in a decrease in the quality of the image, making it difficult to provide as a copy image.

In order to prevent this from happening, it would be sufficient to send the toner from the second toner storage container 9 to the first toner storage container 8 in time to make a regular copy, but conventionally, When a print button (not shown) is pressed to make a regular copy, even if the motor 16 rotates immediately, toner cannot be replenished into the first toner storage container 8 in time, resulting in the above-mentioned problem. It is.

Here, as shown in FIG. 5, if the sensor 13 does not turn on even though the motor 16 has been rotating for 70 hours, a toner end signal is output, but for convenience, this timing is referred to as the E timing. , at this point, the copy shall be made immediately and urgently.

To make the explanation easier to understand, let us assume that the maximum number of copies that can be made if an emergency copy is made after the 1-ner end signal is generated is 25, and the amount of toner replenishment required for this copy is shown in Figure 4. Let the amount be between B level and D level.

The number of such sheets is determined by the 8 ridges of the first toner storage container 8, etc., and is selected from various design considerations, but for the sake of easy explanation.

For convenience, the number was set at 25.

Now, suppose that a maximum of 25 copies are to be made in an emergency, and the timing at which this is completed is designated as timing F in FIG. After timing F, the panel door (not shown) is opened at time G, the second toner storage container 9 is filled with toner, and in this state, when the panel door is closed at time T2, the toner end signal is canceled. becomes.

A panel door switch is involved in the panel door, and this switching operation cancels the output of the toner end signal. In such a situation, with the developer refilled in the second developer storage section,
This constitutes an example of means for canceling the output of the developer end signal.

Here, the feature of the embodiment of the present invention is that, for example, when the output of the toner end signal is canceled.

When an emergency copy is made for 25 sheets, the amount of toner required for this copy and the amount of toner between levels A and B is transferred from the second toner storage container 9 to the point at which the regular copying operation starts. The purpose is to send toner to the first toner storage container D8. That is, the motor 16 is rotated for a predetermined time so that the amount of toner is sent into the first toner storage container 8. Now, assuming that this rotation time is t2 hours, after this elapse, the toner in the first toner storage container 8, which has been at the D level, will change to the A level. In this way, when a regular copy is made, the toner has returned to the A level, and then the toner level is controlled to drop one step lower, which can cause problems such as a decrease in image density. In addition, emergency copies can be made in advance with peace of mind.

Now, in Fig. 5, the timing to open the panel door is G timing as mentioned above, and the timing 2 hours after closing the panel door is L(), and as for the F timing mentioned earlier, the emergency copy If the number of sheets is less than the maximum of 25 sheets, it will tend to approach the E timing, and the G timing is also determined by when the panel door is opened after the F timing.Furthermore, the H timing also depends on those timings. They will fluctuate in a correlated manner.

In addition, in this example, at E timing.

The toner end display blinks, and at timing F when emergency copying of the maximum 25 sheets is performed, for example, a print button (not shown), which has been blue until now, is turned red to prohibit the formation of one image. Also, when toner end output is canceled, I-
The 'f-end display stops blinking and at the H timing, the image formation inhibited state is canceled and the print button is turned blue.

At the time of emergency copying, for example, the number of sheets of transfer paper sent from the paper feed section is counted as 1 to 2 hours, and based on this number of sheets, 2 hours is calculated and set.

Timer ① is a timer for such a two-hour setting. At least when image formation is performed after the developer end signal is output and before the output of the signal is canceled, such a timer is set to , constitutes an example of means for energizing the operation of the developer conveying and replenishing means so that the developer is conveyed from the second developer storage to the first developer storage.

Here, to explain more specifically the amount of toner transported from the second toner storage container 9 to the first toner storage container 8 when the output of the toner end signal is canceled, in this example, the amount of toner is as described above. This is the amount to bring the toner amount, which had decreased after the emergency copy, to level A from the current level.

Therefore, the amount of toner changes depending on the number of copies to be made during emergency copying.

Here, the average amount of 1-ner required per copy is α
(Durham), and assuming that the number of emergency copies after the toner end signal is output is n, the amount of toner G (Durham) obtained by the following equation is conveyed.

G=na+(Gfull-Gend) Here, Gfull is the amount of toner at the A level in FIG. 4, and Gend is the amount of toner at the B level.

The average amount of toner conveyed per unit time by the toner conveyance replenishment screw 15 (Fig. 2) is β, and the pipe 14 (second
(Fig.) Assuming that there is no toner inside the second toner storage container 9.
Assuming that the delay time from when the toner reaches the first toner storage container 8 is Tdly, the driving time t2 of the motor that starts driving when the output of the toner end signal is released is as follows.

t2=G/β+Tdly” ((na+G full-G end)/
β)+Tdly t2 is set using the number of copies as a basic parameter, but there are other parameters.

Development time (time during which the developing roller 5 is rotating)
The time during which the toner is replenished (the time during which the toner replenishment roller 10 is rotating) may be used as a parameter for setting L2.

FIG. 6 is a block diagram of the electrical equipment of this embodiment, and shows the control section 10.
0 is CPU, ROM, RAM, Ilo.

It is composed of a timer and the like, and the output of the toner amount detection sensor is input to the control section 100. The control unit 100 also receives a panel door switch signal for detecting opening/closing of the panel door. On the other hand, a signal for driving or not driving the motor is outputted from the control unit 1/OO via the driver.

A toner end signal for blinking a toner end indicator (LED) on the display panel is also output.

Next, a control method and the like for conveying a predetermined amount of toner when toner end signal output is canceled, including toner end detection control, will be described.

FIG. 7 is a flowchart regarding toner end detection control.

First, it is determined whether there is a previous toner end signal or not, and if there is no toner end signal, the toner amount detection sensor 13 is detected in the first step.
It is determined whether or not it is on.

If it is not on, that is, the toner is low, it is determined in the first step whether or not timer I is on.

If timer I is not on, turn on timer I,
Turn on the motor 16 (Fig. 2) and use the toner transport replenishment screw 15! - Carry out fuel transportation and replenishment. Also,
If the timer I is on, in the next step it is determined whether or not the timer value has reached the set value (set time).
When the set value is reached, a toner end signal is generated. That is, when the sensor 13 does not detect an increase in toner even after a certain set time has passed after the motor 16 starts rotating.

It determines that the toner is at an end and generates a toner end signal.

In Figure 8, only the maximum 25 copies are available in case you want to make an emergency copy after the toner end signal is generated.

FIG. 7 is a diagram showing a control flow up to prohibition of image formation when copying is performed.

When the toner end signal is occurring, first.

The number of copies is checked, and when only 25 copies have been made, if the number is less than 625 copies, which prohibits image formation, the process returns directly.

FIG. 9 is a diagram showing a control flow when toner is transported from the second toner storage container 9 to the first toner storage container 8 after the output of the toner end signal is canceled. During this operation, as described above, the amount of toner conveyed to the first toner storage container 8 is changed depending on the number of copies made after the toner end signal is generated.

Therefore, regardless of the number of copies made after the toner end signal is generated, the
Sufficient toner supply can be performed.

First, in the first step, check whether the timer ■ is on or not. If not, check whether the door open flag is set. If not, check whether the panel door is open. Check whether or not. If it is open, return without doing anything, and if it is open, set the door open plug. Then, on -day, turn off the motor and timer ■.

Next, check whether the panel door is closed.

When the door open flag is set for the first time,
Check whether the panel door is closed without performing the above control. If it is not closed, do nothing and return; if it is closed, reset the door open flag, cancel the output of the toner end signal, clear the timer ■, turn it on, then turn on the motor and return. . After this, toner is sent once.

In the first step, when the timer ■ is on, it is determined whether the timer ■ has reached the set value L2, and if it has not reached t2 yet, it returns, and when it has reached t2, it turns off the motor. to stop the toner conveyance, turn off the timer ■, and cancel the image formation prohibition.

In addition, in FIG. 4, even if emergency copying is not performed after the toner end signal is generated, if the toner is conveyed from the B level to the A level when the output of the toner end signal is canceled, normal copying will be performed. In this case, it can be kept in an initial standby state.

In any case, even after the emergency copy, the toner level is
The level is always A, and there is no possibility that more toner than necessary will be packed into the first toner storage container 8.

Therefore, a slightly upper portion of the sensor 13 may be used as the ceiling of the first toner storage container 8, and the first toner storage container itself can be made as compact as possible.
This is particularly advantageous for color image forming apparatuses having a plurality of developing devices. In short, by performing such delicate level control, toner is not sent to the 11th toner storage container 8 in excess, and the 1st toner storage container itself can be made as compact as possible. Even if you make a copy, you can obtain one image quality that is not too bad, and subsequent regular copies can obtain normal image quality without any problems.

Conventionally, when the panel door is closed, the motor 16
Even if the toner starts rotating, if the toner level in Figure 4 is considerably lower than the B level after emergency copying, the toner will not be conveyed to the first toner storage container 8 in time during regular copying, and one image will be lost. Although there was a problem that the image quality deteriorated due to thinning, the present invention solves this problem.

In the above embodiment, when an emergency copy is performed.

Before performing regular copying, remove the toner from the second toner storage container 9 to the first toner storage container.
Toner storage capacity! The toner was conveyed to the container 8 so that the toner level in the container 8 became the set amount of the A level. That is, the amount of developer transported from the second developer storage section to the first developer storage section was set so that the amount of developer in the first developer storage section was equal to the set amount. Therefore, it is advantageous to be able to reliably prevent the image quality from deteriorating when a regular copy is made. By setting , you can prevent image quality deterioration during regular copying. In other words, the amount of developer transported from the second developer storage section to the first developer storage section is the amount required for image formation after the developer end signal is output and before the output of the signal is canceled. The amount of developer is equal to or greater than the amount of developer used.

Furthermore, when the amount of toner conveyed per unit time by the toner conveyance replenishment screw 15 is large, t may be set so that the toner is conveyed to the first toner storage container 8 to a level lower than the B level. It is possible. For example, even if you set 2 so that toner can be conveyed to level C,
After that, a large amount of toner is stored in the first toner storage capacity H8 in a short period of time.
If the image can be conveyed in a proper manner, it is possible to prevent image quality deterioration during regular copying.

By the way, the developing devices of the embodiments described so far.

Although a two-component developer containing toner and a carrier is used as the developer, the present invention can also be applied to a developing device that uses a one-component developer that does not contain a carrier.

FIG. 3 shows a schematic configuration of such a developing device.

In this example, the first developer storage section 28 that accommodates the developer supplied to the developing roller 5 is also used as a developing tank (corresponding to the developing tank 2 in FIG. 1).

The one-component developer is sent from the second developer storage section 29 to the first developer storage section 28 via the toner transport and replenishment screw 15 . In this example as well, the amount of developer in the first developer storage section 28 is detected by the developer amount detection sensor 23 that constitutes the developer amount detection means. In addition, in the figure,
The reference numeral 24 is a developer supply roller made of an elastic material, and the reference numeral 25 is a blade that thins the developer on the developing roller 5.

Note that when a one-component non-magnetic toner developer is used as the developer, the magnet in the developing roller shown in FIG. 1 may be omitted.

As described above, according to the present invention, in a developing device having two developer storage sections, it is possible to prevent the developer storage section on the developing device main body side from running out of developer, and to prevent the developer from running out on the developing device main body side. Since the developer can be supplied stably at all times, images of good quality can always be obtained, and it is also possible to make the developing device itself more compact.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a dry developing device according to an embodiment of the present invention;
The figure is a sectional view taken along the line X-X in Figure 1, Figure 3 is a configuration diagram of another embodiment, and Figure 4 is a diagram for explaining that the toner level in the 11th hener storage container changes due to emergency copying. Fig. 5 is a timing diagram corresponding to the above embodiment, Fig. 6 is an electrical equipment block diagram corresponding to the above embodiment, and Fig. 7 is a timing diagram corresponding to the above embodiment.
Figure 8 shows the control flow for toner end detection, Figure 8 shows the control flow from execution of emergency copy to prohibition of image formation, and Figure 9 shows the main flow corresponding to the above embodiment. It is. 5...Developer carrying member 8.28...First developer storage section 9.29...Second developer storage section 13.23...Toner amount detection sensor 15...Toner conveyance Replenishment screw 4 Figure 5

Claims (3)

[Claims] (1) A developer carrying member that carries a developer for electrostatic latent image development on its peripheral surface, and a first housing that houses the developer to be supplied to the developer carrying member.
a second developer storage section that stores developer for replenishment; and a developer that transports and replenishes developer from the second developer storage section to the first developer storage section. When it is detected that the amount of developer in the developer transporting and replenishing means and the first developer storage section is less than a set amount, the developer transporting and replenishing means is activated, and
A developer amount detecting means for generating a developer end signal when it is detected that the amount of developer does not reach a set amount regardless of the operation of the developer conveying and replenishing means; means for canceling the output of the developer end signal in a state where the developer is replenished; and at least when image formation is performed after the developer end signal is output and before the output of the signal is canceled, the developer end signal is output. Along with the release, the operation of the developer conveying and replenishing means is activated so that the developer is conveyed from the second developer storage section to the first developer storage section before performing regular image formation. 1. A dry developing device for an image forming apparatus, characterized in that the dry developing device comprises means for: (2) The amount of developer transported from the second developer storage section to the first developer storage section is necessary for image formation performed after the developer end signal is output and before the output of the signal is canceled. Claim 1: The amount of the developer is equal to or greater than the amount of the developer.
The dry developing device described. (3) The amount of developer conveyed from the second developer storage section to the first developer storage section was set so that the amount of developer in the first developer storage section was equal to the set amount. The dry developing device according to claim 1.