JPS63206777A - Image forming device - Google Patents

Abstract

PURPOSE:To uniformly stir a developer even if toner replenishment is interrupted to that an influence on image formation is eliminated by driving a developing device and executing the agitating operation of the developer for the prescribed time after the end of a copying operation. CONSTITUTION:The driving of the developing device which is either of the developing device 5 or 6 and is selected for the purpose of the copying operation or quick replenishment of the toner is driven and the agitating operation is executed for the prescribed time after the end of the copying operation when the copying operation is restarted under the control of a CPU after the above- mentioned developing device is changed over, by an operator's judgement, to the developing device different therefrom during the replenishment of the toner. The developer is thereby uniformly agitated even if the toner replenishment is interrupted. Hindrance of the ensuing image formation is thus obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus equipped with a plurality of developing devices loaded with black toner and color toner. It is involved in controlling the toner replenishment operation when commanded.

[Conventional technology]

When a large number of copies are made using a copying machine, the toner in the developer becomes insufficient and the image density becomes low.
2. Description of the Related Art Copying machines have been developed in which when an operator determines that toner needs to be replenished, the operator can rapidly replenish toner from a toner supply bottle to a developing device by operating a switch.

On the other hand, in response to the increasing demand for paper copies, copying machines equipped with multiple developing units that can make color copies in addition to black copies are being provided. However, there is no toner supply means as described above.

[Problems to be Solved by the Invention] When a plurality of developing devices are provided with toner replenishing means, the following problems occur, unlike when only one developing device is provided. That is, for example, when toner is being rapidly replenished to a color developing device, there is a particular problem when a command is given to start color copying. a command to start copying using a developing device different from that developing device;
In the above example, when the mode is switched to black copy mode and a copy start command is issued, the black developing device starts operating. At this time, in the color developing device where toner had been replenished earlier, the developer was being stirred at the same time as the toner was replenished, but the power transmission from the drive source was switched to the black developing device. As a result, stirring of the developer in the color developing device is interrupted. For this reason, the carrier and toner in the developer are not uniformly mixed, which may cause problems in image formation. However, in such a case, it is possible to solve the problem by transmitting power to both developing units, but in this case it would be necessary to provide a drive source for each developing unit or an arrow-shaped drive source. It cannot be used with other devices.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has the objective of stopping toner replenishment when a command to start an image forming operation is issued to a developing device different from the developing device currently being replenished with toner. In an image forming apparatus equipped with a plurality of developing devices, the agitation operation of the developing device that was previously replenished with toner is restarted after the completion of toner replenishment means. a developing device selecting means for selecting a desired developing device from the plurality of developing devices; a means for instructing toner replenishment; a means for instructing an image forming operation; and a toner replenishment instruction outputted from the toner replenishment instructing means. In response to the signal, the toner replenishing means provided in the developing device selected by the developing device selecting means is activated, and while the toner replenishing means is in operation, a selected developing device switching signal is output from the developing device selecting means, and an image forming operation command is issued. Control for stopping the operation of the toner replenishing means in response to an image forming command signal outputted from the means, and driving the developing device replenished with the toner for a predetermined period of time after the image forming operation is completed. It is characterized by having means.

[For production]

The control means is constituted by a microprocessor, and when a toner replenishment instruction signal is input, it operates the toner replenishment means of the developing device selected at that time. If a different developing device is selected during toner replenishment and a signal instructing image forming operation is input, the operation of the toner replenishing means is stopped, and after the image forming operation is completed, the toner replenished developing device is The developer is stirred by driving the device.

〔Example〕

Embodiments of the present invention will be described below.

In this embodiment, the invention of this application is applied to a copying machine equipped with two developing units.

FIG. 1 is a sectional view showing the main structure of a copying machine,
2 is a photosensitive drum, and the photosensitive drum 2 can be rotated counterclockwise by a main motor (not shown). Around the photosensitive drum 2, a charger 3, an inter-image eraser 4, and first and second developing devices 5, 6 are arranged in order at intervals in the rotation direction thereof.
, a transfer charger 7, a separation charger 8, a cleaner device 9, and a main motor 10, an optical system 0 is located above the photoreceptor drum 2 and its peripheral equipment, and a paper feed system P is located on the left side. , a fixing device 11 is provided on the right side. Note that three or more developing devices may be provided.

The optical system 0 includes a slit exposure type light source 12, a first mirror 13, second and third mirrors 16, 17, a lens 18, and a fourth mirror 19. Reference numeral 21 denotes a document glass, and the document registration mark is moved on the main body of the copying machine to a scanning start position by a scanning motor (not shown) that is driven in response to a scanning command signal.
Move in the direction of the arrow in the figure. During this scanning process, the document glass 2
The original image on 1 is imaged on the photosensitive drum by the optical system O to form an electrostatic latent image. The moving speed V of the document matching mark is
If o is the circumferential speed of the photosensitive drum 20 and m is the copying magnification, then V=Vo/m is set. In addition, when the document platen is always at the scanning start position, it touches the home position switch n to transmit a home position signal to the first CPU 2001c, which will be described later, and synchronizes the document table m and paper feed system P. Therefore, when the original document has moved a predetermined distance to the right after the start of scanning, touch and press the timing switch n, and press the timing switch n.
PU200. K is configured to transmit a timing signal for operating a timing roller A to be described later.

Negatively charged toner supplied from the selectively used first or second developer 5 or 6 is attached to the surface of the photosensitive drum 20, and this toner forms the electrostatic latent image described above. is visualized (developed) to form a toner image on the original image.

Subsequently, the toner image is transferred by the transfer charger 7 from the timing roller 24 located at the most downstream side of the paper feeding system P to a copy paper (not shown) that is supplied to the surface of the photosensitive drum 2 in synchronization with the above-mentioned timing signal. The transferred copy paper is further separated from the surface of the photosensitive drum 2 by a separation charger 8. The copy paper separated from the photosensitive drum l-2 is conveyed by the conveyor belt 5 to a fixing device 11, and after the toner image is heated and fixed by the fixing device 11, it is discharged onto a tray.

The residual toner on the surface of the photoreceptor drum 2 is removed by the cleaner device 9 and collected in the cleaner device 9, and the residual charge on the surface of the photoreceptor drum 2 is removed by the main motor, which is always lit while the main motor is driving. 10.

The paper feeding system P includes a first cassette paper feeding section 28 (hereinafter simply referred to as the first paper feeding section 4) and a second cassette paper feeding section 30.
(hereinafter simply referred to as the second paper feed section) 28a
, 30a are conveyed to the timing roller 24 via first and second paper feed rollers 34 and an intermediate roller 32, respectively.

Each of the rollers 24, 32, 33, 34 is detachably connected to a drive system by a main motor via a clutch (not shown), and by turning on the clutch of each roller, the roller is activated. It is connected to the drive system and rotated by the main motor.

In addition, in the vicinity of each cassette 28a, 30a, there is a size detection sensor 36 for detecting the size of the copy paper stored in each cassette 28a, 30a, and a size detection sensor 36 for detecting the size of copy paper stored in each cassette 28a, 30a, and a size detection sensor 36 for detecting the size of the copy paper stored in each cassette 28a, 30a. Cassette empty sensor g, 3 that detects when empty
8 has been installed.

Next, the configuration of the developing device will be explained. FIG. 2 is a perspective view showing the external appearance of the first developing device 5 loaded with color toner, and since the second developing device 6 is almost the same as this, the first developing device will be described. The numbers in parentheses in the figure are the codes for the second modern great vessel.

A bracket 40 is provided at one end of the first developing device 5 in the longitudinal direction.
A toner replenishing bottle 45 for replenishing toner into the first device 5 is detachably attached to the platen 40. The toner replenishment bottle 45 is rotated by a replenishment motor (not shown) to be supplied with toner, and is further connected to a main motor via a drive connection mechanism (not shown), including a screw for conveying the replenished toner, a developing sleeve, and a screw for stirring. Rotation of packets, etc. is performed. This drive coupling mechanism is configured to transmit the drive from the main motor to either the first developing device 5 or the second developing device 6.

Near the toner replenishment bottle 45 is a toner replenishment bottle sensor 4L that detects whether or not the toner replenishment bottle is attached.
-)'- A toner empty sensor 46 is attached to detect the presence or absence of toner in the supply bottle.

A magnet (47.48) for identifying the color of toner in the developing device can be attached to the upper part of the outer casing of the developing device, and a magnet (47.48) attached to the side of the copying machine opposite to this magnet (47.48) can be attached. The first step is to detect Second reed switch 4
9,5Q are provided. For example, in the case of red toner, if two magnets 47 and 48 are installed, the first and second reed switches that detect this will both be KO.
N, and an identification signal indicating that the toner is red toner is output. Since the magnets 47 and 48 can be attached in four different combinations, it is possible to identify the four colors of toner. Further, this magnet can also be used to detect the attachment state of the first developing device. That is, toners can be identified up to three colors, and the first... The second reed switch is the same! /c
When it is OFF, K may be used to determine that the first developing device has been removed.

Next, the internal structure of the developing device will be explained with reference to FIGS. 3 and 4, but for convenience of explanation, the explanation will start from the second developing device 6 into which black toner is loaded.

The first developing device VcQ is arranged on the downstream side in the rotational direction of the photosensitive drum.

In FIG. 3, reference numeral 71 denotes a toner replenishment gutter, through which the previously described toner, supplied from the replenishment bottle 58, is conveyed by a screw or the like (not shown) so that the toner is replenished uniformly in the width direction of the photosensitive drum. Ru. 72 is a packet for stirring the toner magnetic Kikiria, 73 is a shutter and a developing sleeve 76
It replenishes developer (a mixture of toner and carrier) and blocks it.

FIG. 5 is a perspective view showing the shutter portion of the developing device,
Normally, the shutter 73 is in the open position shown in FIG. 3 due to the action of the arm 790 being pulled up by the spring 78.

Further, when the second developing device 6 is in an inoperative state and the grain cutting operation is performed, the grain cutting solenoid 80 is energized and the arm 79 is pulled down until it hits the stopper 81, so that the shutter 73 is closed as shown in FIG. Take the closed position.

75 is a cylindrical magnet (with 7 magnetic poles formed around the IC).
(hereinafter referred to as magnet), 76 is fitted on the outer periphery of this magnet,
This is a developing sleeve that is rotationally driven by a developing motor (not shown).

When the second developing device 6 is in operation, the packet 72,
The developing sleeves 76 rotate in the directions of arrows a and l) in the figure, and the developer is transferred to the packet 72 in the direction of arrow P in the figure.
From there, it is supplied to the developing sleeve 76 via the upper surface of the shutter 73. The developer supplied onto the developing sleeve 76 is carried in the direction of the arrow as the developing sleeve 76 rotates.
When it comes to the top of the magnetic pole of the magnet 75, a raised ear 77 is formed. When this spike 77 touches the electrostatic latent image on the photosensitive drum 2, toner adheres to the electrostatic latent image and development is performed. After this, the developer is further conveyed as the sleeve 76 rotates,
The magnet π is peeled off from the sleeve 76 at the portion C where the magnetic pole is missing, moves in the direction of the arrow R in the figure, and is collected into the packet 72.

When the second developing device 6 is placed in the inoperative state, the shutter 73 assumes the closed position shown in FIG. ! , the developer that was being stored is also carried along with the rotation of the developing sleeve 76, and the portion C of the magnetic pole of the magnet 75 is missing.
It peels off from the developing sleeve 76, moves in the direction of the arrow R in the figure, and is collected in the bucket) 72, so that there is no developer on the developing sleeve 776.

If the rotation of the developing sleeve 76 is stopped in this state, no developer will remain on the developing sleeve 76 even if the ear cutting solenoid button is turned off and the shutter 73 is returned to the position shown in FIG. 3. .

Next, in order to restore the developing state again, when the developing sleeve 76 is rotated, spikes 77 of the developer are instantly formed on the sleeve 76.

The first developing device 5 is not equipped with the shutter 73 of the second developing device 6, and a fixed guide plate is provided at the position where the shutter 73 is in the open state (see FIG. 3). This is similar to the second developing device 6.

Since the first developing device 5 is loaded with color toner, when color development is performed, when the first developing device is activated, the spikes formed on the developing sleeve cause the photosensitive drum 2
Developing the upper electrostatic latent image is the same as the operation of the second developing device 6 described above. At this time, the second developing device 6 is in an inactive state and no spikes of black developer are formed on the sleeve, so the image developed with the force 2 toner does not come out. Further, when developing the electrostatic latent image on the photosensitive drum 2 with the second developing device 6, the first developing device 5
is set to an inactive state, and rotation of the developing sleeve is stopped. Then, the developing bias of the first developing device 5 is changed,
To prevent toner from adhering to the electrostatic latent image. by this,
Even if spikes of color developer are formed on the developing sleeve, toner does not adhere to the electrostatic latent image, and the electrostatic latent image is then developed with the black developer in the second developing device, which poses no practical problem. There is no.

In FIGS. 3 and 4, AS2 is a sensor (hereinafter referred to as ATDC sensor) that detects the toner content ratio in the developer of the second developing device 6, and the same applies to the first developing device 5.
ATDC sensor As□ is installed.

Since it is difficult to directly detect the toner content ratio during development, the amount of magnetism of the magnetic carrier is detected and the toner content ratio is determined from this. For this reason, a developer containing toner at a specified content ratio is first loaded, and the detection level detected by the ATDC sensor is set as a reference value. From then on, toner power [When refilled, after thoroughly stirring the carrier and toner, ATDC
The toner content ratio is determined by detecting it with a sensor and comparing it with a reference value.

Next, the operation panel of the copying machine 1 will be explained.

At the top of the copying machine 1, there is an operation panel 1 as shown in FIG.
00, and the operation panel 100 includes a print key 102 for commanding the start of copying, and an interrupt key 103.
．． In addition to stopping copying immediately after starting copying or in the middle of multi-copying (successive copying of multiple sheets based on the same original),
Copy number display section 104 consisting of LED group Clear/K Clear the set number of copies and return to standard mode @l''
stop key 105, the number of copies display section 104, numeric keys 106 to 115 for setting the number of copies, and the light source 1.
an exposure variable resistor VR that manually increases or decreases the exposure amount from 2; and an automatic exposure mode switch 117 that automatically provides the optimum exposure amount for the original;
Paper feed selection switch 118 for selecting the paper feed section 28,30 of
, LED 11 to display the selected paper source; 120° cuff for selecting color copy or black copy;
Black copy selection switch (hereinafter referred to as color selection switch 5) 121, LED that displays the developing device 5 or 6 selected by the color selection switch 122° 123, toner supply bottle attached to the selected developing device 5 or 6 41 or LED to indicate when the edict is empty
124 are provided.

Next, a control circuit for controlling the copying machine, such as the copying operation of the copying machine and the selection control of the developing device when the first developing device or the second developing device is selected, will be described.

FIG. 7 is a block diagram of the control circuit, in which the first and second
microprocessor (CPU) 200 and 300
The inner cylinder 1 CPo 200K has various keys on the operation panel 100, the first . Second bottle presence sensor 41
, 53, 1st. 2nd bottle empty sensor 46°■,
The first step is to detect the toner color. Second reed switch 49.
A switch matrix S consisting of 50 etc. arranged vertically and horizontally is connected, and the above-mentioned main sweater, various roller clutches, etc.
Operated and controlled by CPo 200 K,
Various LEDs such as the copy number display section 104 are turned on and off via the decoder 133.

On the other hand, the 20th PU 300 is connected with a scanning motor control, a variable magnification lens control unit, a document table fixed position switch n, a timing switch n, etc.
The CPU 300 mainly controls the optical system 0 and scanning of the original. The first CPU 200 and the second CPU 30
0 are connected to each other for mutual synchronization.

Next, an outline of the main operations of the control circuit will be explained.

(1) Outline of copying operation In this embodiment, a color developing device and a black developing device are installed, and it is possible to select between color and black copying. When you select color copy or black copy by operating the color selection switch 121 on the operation panel,
A selection signal is input to the first CPU 200.

The first CPU turns on one of the lights selected according to this input signal. Note that the switching operation of the developing device is not started at this point.

Copy paper size, number of copies, etc. are also input using the keys on the operation panel using the first CPUK.

Next, when the print key 102 is operated to input a signal instructing the start of copying to the first CPUK, the first CPU checks the input developer selection signal. If the same developing device as the developing device used in the previous copying operation and already set is selected, the copying operation is started. The control of the copying operation is the same as that employed in known copying machines, so a description thereof will be omitted. When a developing device different from the already set developing device is selected, the switching operation to the selected developing device is performed, that is, the selected developing device is set to the operating state, and the other developing devices are set to the inactive state. Start the action to be set.

Then, the signal outputted when the switching operation of the developing device is completed is checked, and if the signal is outputted, the copying operation is started.

(2) Developing unit loading process In this embodiment, the first developing unit 5 loaded with color toner is configured to be detachable, and the second developing unit 6 loaded with black toner is fixed. It has been installed. If the first developing device is not installed or is removed during a copying operation, even if a latent image is formed on the photosensitive drum, it will be erased by external light and cannot be copied. For this reason, the mounting state of the developing device is detected before and during the copying operation.
When non-installation is detected, the copying operation is stopped by the same process as when the % key is pressed.

To detect the mounting state of the developing device, the first CPU detects that the reed switches 49 and 50 on the copying machine side, which detect the magnets 47 and 48 that identify the toner color loaded in the first developing device 5, are both OFF. When the first developing device 200 is detected, it is assumed that the first developing device has been removed.

(3) Rapid Toner Replenishment Process The copying machine of this embodiment uses a mixture of toner and magnetic carrier as the developer. When copying operations are performed continuously, particularly when copying an original document with a high image density, the ratio of toner in the developer decreases and the image density decreases. Therefore, it is necessary for the operator to consciously replenish the toner during the copying operation and to stir the toner so that it is sufficiently mixed with the magnetic carrier. In addition, if you accidentally replenish toner when the toner content ratio in the developer is sufficiently high, problems such as toner overflowing from the developer will occur, so the toner content ratio in the developer can be detected and unnecessary toner replenishment can be avoided. [I need to do it.]

Therefore, rapid toner replenishment is achieved by turning on "0" on the numeric keypad on the operation panel 100 and turning on the drum dry switch (not shown) attached to the side of the copying machine.
The CPU 200 judges these signals and drives the toner replenishment motor of the developing device 5 or 6 selected at that time to supply the toner pol b45 (5B).
) to supply the toner to the developing device 5 (6). Furthermore, the main motor drives the stirring packet 72 that rotates together with the developing sleeve 76 of the selected developing device 5 or 6 by determining whether the drum dry switch is ON, and stirring the developer. The toner content ratio of the developer in 5 or 6 is detected using the amount of magnetism of the magnetic carrier as a clue, and when the toner content ratio is above a predetermined ratio, toner replenishment is prohibited. Further, when the copy mode is switched from black copy to color copy during rapid toner replenishment, the rapid toner replenishment is interrupted and the stirring operation is restarted after the copying operation is completed. This is because if the stirring operation is performed on two developing units at the same time, the load on the main motor becomes excessive.
This is because there is a risk that copying operations will be hindered.

In the above description, it has been stated that the developer is stirred when the drum dry switch is turned on, but the drum dry process will now be briefly explained. .

This may occur when using a copying machine in a cold region, etc.
The photoreceptor of a copier that has been left in a cold room for a long time may have condensation. For this purpose, the front photoconductor drum used in the copying machine is rotated for a predetermined period of time, and the main motor is turned on to warm the photoconductor, and an agitation operation is also performed to generate air flow and dry it.

Next, the CPU 200. The control operation for the processing performed in step 300 will be explained.

In addition, in the flowchart explained below, the color developing device 5
It shall be removable only.

(1) Main routine Chart 70 in FIG. 8 shows an outline of the control operation of the image forming apparatus. When the power is turned on and the operation starts, the memory is initialized, initial values of flags and the like are set, the number of copies is set to 1, and the copy mode is initialized (step M1).

Next, an internal timer that controls the processing time of the main routine is set and counting starts (step M2). Processing such as external input and control output to the image forming apparatus is performed (step M3). After this, processing of the color copy selection switch and drum dry selection switch, which will be explained in detail later, is performed (step M4.MS), and furthermore, signal processing input from switches on the operation panel, etc. is performed (step M6). . In addition, toner rapid replenishment processing, color developer installation detection processing, display flick processing,
Selective developer display processing, drum dry processing, ear cutting processing,
A series of processing such as function processing is performed (steps M7 to M13). Next, known image forming processing, that is, charging the photoreceptor, exposure, development, feeding and transfer of copy paper, fixing, and other processing is performed (step M14), and furthermore, jam detection of the transfer paper and other abnormalities are performed. Other control processing such as detection is performed (step M15), and after waiting for the internal timer to finish counting (step M16), the process returns to step M2 to proceed to the next cycle of processing.

Routines directly related to this invention will be described in detail below.

r2) Color copy selection switch processing routine 8th
Regarding the color copy selection switch process shown as step M4 in the flowchart shown in the figure, 70 in FIG.
- Char) K will explain the details.

When a color copy is desired, the color copy selection switch 121 on the operation panel is turned on, but if a rapid toner replenishment operation is in progress at this time, this process is interrupted. First, make sure that no other key switches are pressed and that copying is not in progress (step S Zoo,
S101), then the state of the color copy selection switch is checked (step 5102), and if it is ON, it is checked whether the flag FcL indicating color copy mode selection is 1 (step 8103). If it is 1, the color developing device has already been selected, so the toner rapid replenishment interruption process is performed (step S104), 7-ygF'ct
is reset to O to set the black copy mode and terminate the process.

If the flag FCL is not 1 in step 5103, step S L06 K checks whether or not the transfer color developing device 5 is installed, and if it is not installed, the process ends; 1 FCL
to set the color copy mode, and perform toner rapid replenishment interruption processing (step 5lo7, 810).
8) End the process. The rapid toner supply interruption process will be explained in detail.

(3) Drum dry switch processing routine The drum dry switch processing shown as step M5 in the flowchart shown in FIG. 8 will be explained in detail with reference to the flowchart shown in FIG.

This switch is used to remove condensation from the photoreceptor drum and to start rapid toner replenishment.

First, it is checked whether the drum dry switch is pressed and the trigger is output (step 5ill), and if the trigger is output, it is checked whether "0" on the numeric keypad is turned on (step 5112). Pressing "0" on the numeric keypad is a command for rapid toner replenishment, so set the flag FTN to enter toner replenishment mode (5113) and memorize the set toner mode (black or color). In order to do so, the contents of the flag FOI are transferred as the contents of the flag FTOL (step 511).
4). Next, the drum dry mode is set (step 8115), and the process ends. If the numeric keypad is not ON in step 8112, the process moves to step 5115 because rapid toner replenishment has not been commanded. Step S
If the ON trigger of the drum dry switch is not output at step 11'l, the process moves to step 8116, and it is checked whether the OFF trigger was output when the drum dry switch was turned OFF. If the OFF trigger is being output, it is checked whether or not the toner replenishment mode is in effect (step 8117). This happens if you turn the drum dry switch to 0FFK while replenishing toner in toner replenishment mode.
This is because if the replenished toner is not sufficiently agitated with the carrier, this will cause a problem in development, so in this case, the agitation of the developer is continued. Therefore, as a result of the determination in step 5117, if the toner replenishment mode is selected, the process is immediately terminated, and if it is not the toner replenishment mode, the drum dry mode is canceled, the drum tristate is set to 4, and the process is terminated. The drum tri-state will be explained in the explanation of the root removal drum drying process.

(4) Rapid toner replenishment interruption process routine The rapid toner replenishment interruption process shown as step M7 in the chart 70 shown in FIG. 8 will be explained in detail with reference to the chart 70 in FIG. 11.

The rapid toner replenishment is interrupted when the color copy selection switch is turned on, and is indicated at 70 in FIG.
- chart step 5104. This is the content of the processing performed in 5108.

First, it is checked by the 7-lag FTN indicating the toner replenishment mode whether or not rapid toner replenishment is being performed (step 812).
1), if FTN = 1, that is, in the toner replenishment mode, it is checked whether replenishment has ended (step 5122).

If replenishment has not yet been completed, check whether or not replenishment is yet to be completed. If replenishment is not yet complete, set the drum tristate to 6 in the drum dry processing routine that will be explained later; if not, set drum tristate to 7. (Step sB3.
8124.8125) End the process. Step 512
If the determination in step 5122 is 7 lag FTN % 1, and if the determination in step 5122 is that replenishment is complete, the process ends.

(5) Color developer attachment detection process The color developer attachment detection process shown as step M8 in the flowchart shown in FIG. 8 will be explained in detail with reference to the flowchart in FIG.

First, it is detected whether the color developing device has been removed from the copying machine main body (step 8131). As described above, this detection can be performed as if the developing device has been removed when the magnetic code signal for detecting the color of toner loaded in the color developing device becomes OFPK. When the developer is removed, reset the 7-lag FcL to OK in order to switch to the black toner developer mode. Then, to stop the copying operation if it is in progress,
Checks whether the flag FCjL indicating that copying is in progress is 1, and if copying is in progress, stops the copying with 7 lags F's'
Set r to lVC (8133, 5134-) and end the process. In step 5131, if the result of the determination by Stella 25133 is negative, the process is immediately terminated. In addition,
The control for stopping the copying operation by determining the flag F's'r is K, which is the same as the stop control when the %° key on the operation panel is pressed.

(6) Drum dry processing routine Regarding the drum dry processing shown as step Mll in the flowchart shown in FIG.
Flowchart in the figure) The details will be explained from K.

FIG. 13 shows the processing of subroutines from state 0 to state 7 adopted in the drum drying process. ~D115) to perform processing.

FIG. 14 is a 70-chart of drum tristate o, which starts the drum drying process. First, check whether the drum dry mode graph FDD is 1 or not (
Step D121), if the flag is 1, that is, drum dry mode, the main motor is turned on and the developing bias is turned on (steps D122 and D123). It is checked whether or not a copying operation is in progress, and if the copying operation is in progress, the scanner is returned to the scanning start position (step D124.D
125). When a copy operation is in progress, step D125 processing is omitted. Set the auto-shut state to OK to prevent the automatic stop operation from starting, set the delay timer to delay when the transfer charger is turned on, and set the drum tri-state to 1 (step D).
126 to D128), the process ends. The reason why the transfer charger is turned on later than the main motor is to prevent the transfer charger from operating before the main motor reaches normal rotation and causing an overcharge state.

As a result of the determination in step D121, if it is not the drum dry mode, it is checked whether the copy flag FcP is O or not, and if the copying operation is not in progress, the toner supply motor is turned off (steps D129 and D130), and the process ends. When a copy operation is in progress, the process of step D130 is omitted.

FIG. 15 is a flowchart of drum tristate 1, in which preparations are made for turning on the transfer charger and detecting the toner content ratio in the developer. First, check whether the transfer charger ON play timer set in state 0 has finished counting (step D141), and if timing has not finished, the process ends, but if timing has finished, turn on the transfer charger (step D142). , select whether or not toner replenishment mode is set to 7.
Check the lag FTN (step D143). In the toner replenishment mode, a play timer that delays the start of detection by the ATDC sensor is set, the drum state is set to 2 (steps D144 and D145), and the process ends. Further, when not in the toner replenishment mode, the transfer charger ON time in drum dry processing is defined. Set the timer and set the drum state to 5. Step D146. D147 End/end L processing.

FIG. 16 is a flowchart of drum tri-state 2, in which the end of the ATDC sensor detection start play timer set in step 1 is checked (step D151).
, if the time measurement has not finished, the process ends, but when the time measurement has finished, a timer that specifies the detection time of the ATDC sensor is set, and the detection signal of the ATDC sensor is read while this timer is measuring time, and the average value is calculated. and set the drum tri-state to 3 in step D152. D153
), the process ends.

FIG. 17 is a flowchart of drum tristate 3, in which toner replenishment processing is performed. First, it is checked whether the timer that defines the ATDC centimeter detection time set in step 2 has ended (step D161), and if the timer has not finished counting, the process ends, but if the timer has finished counting, it is detected by the ATDC sensor. It is checked whether the content ratio of the loaded toner is equal to or higher than the specified value (step D162), and if the content ratio is equal to or higher than the specified content ratio, the drum tri-state is set to 6 to terminate toner replenishment.
Step D163) and the process ends. When the toner content ratio is below the specified content ratio, the flag FTOL is used to check whether the toner to be replenished is color or black, and depending on the determination, the toner replenishment motor for the color developer 5 or the toner replenishment motor for the black developer 6 is turned ON. Then, the toner replenishment time timer is set, the drum tri-state is set to 4 (steps D164 to D167), and the process ends.

FIG. 18 is a flowchart of drum tristates 4 and 7, which is a routine for finishing toner supply and stirring the developer. First, when this routine is entered in drum tri-state 4, it is checked whether the timer that defines the toner replenishment time set in drum tri-state 3 has finished counting (step D171), and if the timer has not finished counting, the process is terminated. When finished, stop the toner replenishment motor, set a timer to stir the developer in the toner-supplied developer for a predetermined time, operate the developer, and set the drum tri-state to 5 ( Steps DI72 to D174), the process ends.

Also, this routine with drum tri-state 7.

When entering, the process moves to step D172.

FIG. 19 is a flowchart of drum tri-states 5 and 6. When this routine is entered in drum tri-state 5, if toner is replenished to a developing device that is not used for copy washing during copying operation, that developing device Since the developer stirring operation cannot be performed, the stirring operation is restarted after copying is completed.

Further, when this routine is entered in drum tristate 6, the drum drying process is ended.

When this routine is entered in the drum tristate 5, first, it is checked with 7 lag F'ap whether or not a copy operation is in progress (step D181), and Fcp'xi: O1, that is, if a copy operation is in progress, the color When toner is replenished, the agitation time continues to be counted, and when black toner is replenished for color copying, or color toner is replenished for black copying, judgment is made to end the process without stirring. (Steps D182 to D18
4).

Then, if it is determined in step D181 that the copying operation is not in progress, and if it is determined in steps D182 to D184 that stirring can be continued, the process moves to step D185, where the stirring timer is counted and it is determined whether the timer has finished counting. If the timer has not finished, the process ends, but when the timer has finished, the drum drive flag FDD and )ner7rag FTN are reset to 0, the auto shut state is set to 1, and the end process is started. The tristate is reset to OK (steps D186 to D189), and the process ends.

〔Effect of the invention〕

As explained above, the present invention differs from this when replenishing toner at the operator's discretion for a developing device selected for a copy operation or for rapid toner replenishment among a plurality of developing devices. When the copying operation is started by switching to the developing device, the supplied toner is not sufficiently stirred with the carrier and the copying operation is interrupted, but after the copying operation is completed, the developing device is driven and the stirring operation is continued for a predetermined period of time. Since this is done, even if toner supply is interrupted, the developer is uniformly stirred and there is no problem in subsequent image formation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main structure of a copying machine to which the present invention is applied, FIG. 2 is a perspective view showing the external appearance of the developing device, and FIGS. 3 and 4 are sectional views showing the internal structure of the developing device. , FIG. 5 is a perspective view of the shutter portion of the developing device, FIG. 6 is a front view of the operation panel, FIG. 7 is a block diagram of the control circuit, and FIGS.
9 are flowcharts showing the control process of the copying machine processed by the microprocessor. 1: Copying machine, 2: Photosensitive drum, 5, 6: Developing device, 0:
Optical system, 20 = document table, oil, 30 = power set paper feed section. Patent applicant Minolta Camera Co., Ltd. Figure 9 Figure 10 Figure 12 Figure 14 Figure 16 Figure 18

Claims (1)

[Claims] In an image forming apparatus equipped with a plurality of developing devices, the plurality of developing devices include a toner replenishing device, a developing device selection device that selects a desired developing device from the plurality of developing devices;
a means for instructing toner replenishment, a means for instructing an image forming operation, and a toner replenishing means provided in a developing device selected by a developing device selecting means in response to a toner replenishment instruction signal output from the toner replenishment instructing means. is activated, and when the selected developing device switching signal is output from the developing device selection device while the toner replenishing device is in operation, and an image forming command signal is output from the image forming operation commanding device, the toner replenishing device is activated in response to this. 1. An image forming apparatus comprising: a control means for stopping the operation of the toner and driving the developing device replenished with the toner for a predetermined period of time after the end of the image forming operation.