JPS63206775A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate the need for a switch for quick replenishment of a toner and to execute replenishment and agitation of the toner so that multiple functions are realized by making common use of a black/color copying selection switch with a selection switch for a developing device to be replenished with the toner. CONSTITUTION:A selection signal is inputted to a CPU 200 and the change-over operation of the developing device is executed when color copying or black copying is selected by operating the color selection switch 121 on a control panel 100. The CPU 200 replenishes the toner to one developing device selected at this point of the time when a numeric key '0' on the panel 100 and a drum dry switch on a copying machine side are turned on. The developer of the selected developing device is further agitated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image forming apparatus equipped with a plurality of developing devices loaded with black toner and color toner, and in particular, to control selection of a developing device for replenishing toner. Regarding.

[Conventional technology]

When a large number of copies are made using a copying machine, the toner in the developer becomes insufficient, resulting in a decrease in image density. For this reason,
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 color copies, copying machines equipped with multiple developing devices that can make color copies as well as black copies are being provided. There is no toner replenishment means as described above. [Problems to be Solved by the Invention] When a plurality of developing devices are provided with toner replenishing means, a means for selecting the developing device to which toner is to be replenished is required to determine which developing device should be replenished with toner. It is possible to temporarily solve this problem by providing a special switch, but if the device is small and is handled by someone inexperienced, using the above method, which requires a complicated operation panel, may cause erroneous operation. This also causes an increase in costs.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention is designed so that a switch for selecting black copy or color copy is also used as a switch for selecting a developing device to which toner is to be replenished, and a plurality of developing devices are installed. In the image forming apparatus, a plurality of developing devices each include a toner replenishing means, a developing device selecting means for selecting a desired developing device from the plurality of developing devices, a means for instructing toner replenishment, and the toner replenishing device. The present invention is characterized by comprising a control means for operating a toner replenishing means provided in a developing device selected by the developing device selecting means when toner replenishment is instructed by the replenishment instruction means.

[For production]

When it is necessary to replenish toner to the developing device manually, select color copy or black copy. Select the developing device to replenish toner from the copy mode selection switch. The developing device selection signal and another switch. A signal instructing toner replenishment is inputted from the controller to a control means comprised of a microprocessor. The control means operates a toner replenishing means provided in the selected developing device to replenish toner to the developing device.

〔Example〕

An embodiment 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 cross-sectional view showing the main structure of a copying machine.
2 is a copying machine, and 2 is a photoreceptor drum. The photoreceptor drum 2 can be rotated counterclockwise by a main motor (not shown). Around the photoreceptor drum 2, at intervals in the rotational direction, there is a sequential charger 3, an inter-image eraser 4, and first and second developing units 5, 6.
, 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 and 17, a lens 18, and a fourth mirror 19.

Reference numeral 21 denotes a movable document table, and 21 denotes a document glass. The document table 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. Then move in the direction of the arrow in the figure. During this scanning process, the original image on the original glass 21 is imaged onto the photosensitive drum by the optical system 0 to form an electrostatic latent image. The moving speed V of the document table is the circumferential speed V of the photosensitive drum 2. , if the copying magnification is m, then V=V (set to 17 m).Furthermore, when the original is always at the scanning start position, touch the home position switch n to send a home position signal to the first CPU 200, which will be described later. At the same time, in order to synchronize the document base and the paper feed system P, when the document base has moved a predetermined distance to the right after the start of scanning, the first CPU 200 It is configured to transmit a timing signal for operating a timing roller, which will be described later.

Negatively charged toner supplied from the selectively used first or second developer i5 or i6 is attached to the surface of the photosensitive drum 2, and this toner forms the electrostatic latent image. It is visualized (developed) to form a toner image corresponding to the image of the original.

Subsequently, the toner image is transferred by the transfer charger 7 from the timing roller located at the most downstream position of the paper feed 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 2 is conveyed to the fixing device 11 by a conveyor belt stone, and after the toner image is heated and fixed in the fixing device 11, it is transferred to the tray 26.
is discharged to the top.

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 feeding/paper section 28 (hereinafter referred to as
(simply referred to as the first paper feed section 4), and the second cassette paper feed section 3.
0 (hereinafter simply referred to as the second paper feeding section), the first and! X2 paper feed section (cassette attached to 30) 28a
, 30a are conveyed to the timing roller 24 via first and second paper feed rollers 33 and 34, and an intermediate roller 32, respectively.

Each of the above rollers 24, 32, 33, 34 is ? It is detachably connected to the drive system by the main motor via a latch (not shown), and by turning on the clutch of each roller, the roller is connected to the drive system and rotationally driven 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 the copy paper stored in each cassette 28a, 30a. A cassette empty sensor 37 that detects when the cassette is empty.
38 are 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 also substantially the same, the first developing device will be described. Note that the reference numerals in the figure enclosed in parentheses are the reference numerals of the second developing device.

A bracket 40 is provided at one longitudinal end of the first developing device 5, and a toner supply bottle 45 for replenishing toner into the first developing device 5 is detachably attached to the bracket 40. The toner replenishment bottle 45 is rotated by a replenishment motor (not shown) and 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 an agitator. The packets and the like are rotated. 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, there is a toner replenishment bottle presence sensor 41 that detects whether or not a toner replenishment bottle is attached.
A toner empty sensor 46 is attached to detect the presence or absence of toner in the toner supply bottle.

A magnet (47.48) that can identify the color of the toner inside the developing device can be attached to the top 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
9.50 will be 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 turn off.
N, and an identification signal indicating that the toner is red toner is output. Since four types of combinations are possible for the attachment pattern of magnets) 47 and 48, it is possible to identify 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... Both reed switches are OFF.
When it is FF, K may be set so that it is determined 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. For convenience of explanation, the explanation will start from the second developing device 6 into which black toner is loaded.

The second developing device 6 is disposed on the downstream side in the rotational direction of the photosensitive drum with respect to the first developing device loaded with color toner.

In FIG. 3, reference numeral 71 denotes a toner replenishment gutter, and the toner supplied from the toner replenishment bottle described above is conveyed by a screw or the like (not shown) so that the toner is replenished uniformly in the width direction of the photoreceptor drum. 72 is a packet for stirring the toner magnetic Kikiria; 73 is a shutter for replenishing developer (a mixture of toner and carrier) to the developing sleeve 76;
It also blocks this.

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 under the action of an arm 79 pulled up by a spring 78.

Further, when the second developing device 6 is inactive and the ear cutting operation is performed, the ear cutting solenoid 80 is energized and the arm 79 is pulled down until it hits the stopper 81, so that the shutter 73 closes as shown in FIG. take a position.

75 is a cylindrical magnet (hereinafter referred to as magnet) having seven magnetic poles formed around its periphery, and 76 is a developing sleeve fitted around the outer periphery of this magnet and 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 b in the figure, respectively, and the developer is supplied from the packet 72 to the developing sleeve 76 through the upper surface of the shutter 73 in the direction of arrow P in the figure. The developer supplied onto the developing sleeve 76 is carried in the direction of the arrow as the developing sleeve 76 rotates, and when it comes over the magnetic pole of the magnet 75, a raised spike 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. Thereafter, the developer is further carried along with the rotation of the sleeve 76, peeled off from the sleeve 76 at the portion C where the magnetic pole of the magnet 75 is missing, moves in the direction of arrow R in the figure, and is collected in the packet 72.

When the second developing device 6 is placed in an inoperative state, the shutter 73 assumes the closed position shown in FIG. The developer is also carried along with the 60 rotations of the developing sleeve 76, peeled off from the developing sleeve 76 at the portion C where the magnetic pole of the magnet 75 is missing, moves in the direction of arrow R in the figure, is collected in the packet 72, and is not deposited on the developing sleeve 76. There will be no developer left.

If the rotation of the developing sleeve 76 is stopped in this state, the state where there is no developer on the developing sleeve 76 can be maintained even if the ear cutting solenoid is turned off and the shutter 73 is returned to the position shown in FIG. dripping

Next, when returning to the developing state again, the developing sleeve 76 is rotated, and 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, but is provided with an Ic fixed guide plate at the position where the shutter 73 is in the open state (see FIG. 3), but the other configuration is as follows. 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
The operation in which the upper electrostatic latent image is developed is the same as that of the second developer 6 described above. At this time, the second developing device 6 is in an inactive state, and black developer is on the sleeve.
Since no folding ears are formed, the image developed with color toner will not be exposed. Further, when the electrostatic latent image on the photosensitive drum 2 is to be developed by the second developer 6, the first developer 5 is set to an inactive state and the rotation of the developing sleeve is stopped. Then, the developing bias of the first developing device 5 is changed to make it difficult for toner to adhere to the electrostatic latent image. As a result, 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, making it practical. There is no problem at all.

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. Thereafter, when toner is replenished, the carrier and toner are sufficiently stirred and then detected by an ATDC sensor and compared with a reference value to determine the toner content ratio.

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.
, stop copying immediately after copying starts or in the middle of multi-copying (successive copying of multiple sheets based on the same original), and
Clear the number of copies set on the number of copies display section 104 consisting of a group of LEDs and return to standard mode 11#.
a stop key 105, numeric keys 106 to 115 for setting the number of copies on the copy number display section 104, and the light source 12.
an exposure variable resistor VR that manually increases or decreases the exposure amount from the document; an automatic exposure mode switch 117 that automatically provides the optimum exposure amount for the original; and a first or second paper feed section 28.30. a paper feed selection switch 118 to select;
LED to display selected paper source 119, 120° Color l to select copy or black copy
A black copy selection switch (hereinafter referred to as a color selection switch) 121, an LED 122° 123 that displays the developing device 5 or 6 selected by the color selection switch, and a toner supply bottle 41 attached to the selected developing device 5 or 6. or an LED to indicate when 53 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° mark,
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 motor, various roller clutches, etc.
It is operated and controlled by the CPU 200, and various L such as the copy number display section 104 are displayed via the decoder 133.
The ED is turned on and off.

On the other hand, the second CPU 300 is connected to a scanning motor control unit, a lens control unit for variable magnification, a fixed position switch for the original platen, a timing switch, etc., and this 20th PU 300 mainly controls the optical system 0 and the scanning of the original. Control. The first CPU 200 and the second CPU 3'
OO 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 copying 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 outputs a signal indicating the selected developer according to this input signal, and lights up either LED m or ÷. 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 to the first CPU using keys on the operation panel.

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 attachment detection processing In this embodiment, the first developing unit 5 loaded with color developing units 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 is performed continuously, especially when copying originals with high image density, the ratio of toner in the developer decreases and the image density decreases. It is necessary to consciously replenish the toner inside the developer and stir it so that it is sufficiently mixed with the magnetic carrier.Also, if you accidentally replenish the toner when the toner content ratio in the developer is high enough, the toner will be removed from the developer. Since troubles such as overflow may occur, it is necessary to detect the toner content ratio in the developer to avoid unnecessary toner replenishment.

Therefore, rapid toner replenishment is achieved by turning on "0" on the numeric keypad on the operation panel 100 and the drum dry switch (not shown) attached to the side of the copying machine.
The CPU 200 determines these signals and drives the toner replenishment motor of the currently selected developing device 5 or 6 to replenish toner from the toner bolt 45 (58) to the developing device 5 (6). Furthermore, turn on the drum dry switch.
The main motor drives the stirring packet 72, which rotates together with the developing sleeve 76 of the selected developing device 5 or 6, to stir the developer.

Further, the toner content ratio of the developer in the developing device 5 or 6 is detected using the amount of magnetism of the magnetic carrier as a clue, and when the toner content ratio is equal to or higher than a predetermined ratio, toner replenishment is prohibited. Furthermore, 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 resumed after the copying operation is completed. This is because if the stirring operation is performed on two developing devices at the same time, the load on the main motor becomes excessive, which may interfere with the copying operation.

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 reason, before using a copying machine, the photoreceptor drum is rotated for a predetermined period of time, and the main motor is turned on to warm the photoreceptor and create an air flow to dry it. It is called processing.

In drum dry processing, the photoreceptor drum is rotated, so
At the same time, the developer is stirred in the developing station 9-kl-.

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

In addition, in the 70-chart explained below, the color developing device 5
It shall be removable only.

(1) Main Routine The flowchart 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 IK, 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, the color copy selection switch processing and drum dry selection switch processing, which will be explained in detail later, are performed (steps M4 and M5), and further,
Signals input from switches on the operation panel etc. are processed (step M6). Subsequently, a series of processes such as toner rapid replenishment interruption process, color developer attachment detection process, display flick process, selected developer display process, drum drying process, spike cutting process, and function process are 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.

(2) Color copy selection switch processing routine No. 8
Regarding the color copy selection switch process shown as step M4 in the flowchart shown in the figure, 70 in FIG.
The details will be explained below.

When a color copy is desired, the color copy selection switch 121 on the operation panel is turned on, but if a toner rapid replenishment operation is in progress at this time, this process is interrupted. First, confirm that no other key switch is pressed and that copying is not in progress (step S100,
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 FOL indicating selection of color copy mode is 1 (step S103). If it is 1, the color developing device has already been selected, so a rapid toner replenishment interruption process is performed (step S104), the flag FOL is reset to 0, and the process is ended in black copy mode.

If the 7-lag FCL is not 1 in step 5103, step 8106K checks whether the transfer color developing device 5 is installed, and if it is not installed, the process ends, but if it is installed, the flag FCL is is set to 1 to set the color copy mode, and perform toner rapid replenishment interruption processing (steps 5107 and 8108).
), the process ends. The toner rapid 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 the diagram 'M1Ω.

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 turned on (step 5ill), and if the trigger is output, it is checked whether 10# on the numeric keypad is turned on (step 5112). Pressing @0# on the numeric keypad is a command for rapid toner replenishment, so set 7 lag FTN to enter toner replenishment mode (5113) and change the set toner mode (black or color). In order to store it, the contents of the 7g F'cL are transferred as the contents of the flag FTOL (step 8114).
). Next, the drum driver and current mode are set (step 8115, and the L process ends. If the numeric keypad is not turned on in step 5112, rapid toner replenishment has not been commanded, and the process moves to step 8115. Step 5I
In II, when the drum dry switch is turned OFF (ON) If the trigger is not being output, the process moves to step 8116, and it is checked whether the OFF (OFF) trigger is output when the drum dry switch is turned OFF. OFF) When the trigger is being output, it is checked whether or not the toner replenishment mode is in effect (step 8117). This (i) If you turn off the drum dry switch while replenishing toner in toner replenishment mode,
This is because if the replenished toner is not sufficiently stirred with the carrier, this will cause a problem in development, so in this case, stirring 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 flowchart shown in FIG. 8 will be explained in detail with reference to chart 70 in FIG. 11.

To interrupt rapid toner replenishment, press Power 2 - Copy selection switch to O.
This is done when the state becomes N, and is shown in 70- in Figure 9.
Chart step 8104. This is the content of the processing performed in 5108.

First, it is checked with the 7-lag FTN indicating the toner replenishment mode whether or not rapid toner replenishment is being performed (step 512).
1), if FTN = I, that is, in the toner replenishment mode, it is checked whether replenishment has ended (step 5122).

If replenishment is not completed, check whether it is before replenishment, and if it is before replenishment, set the drum tristate to 6 in the drum dry processing routine that will be explained later, and if it is not before replenishment, set the drum tristate to 7. Set (step 8123
．． 5124.5125) End the process. Step 51
If the flag FTN "r;; is 1 in the determination of step 5121, and if the replenishment is completed in the determination of step 5122, 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 5131). 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 is turned OFF. When the developer is removed, the 7-lag FCL is reset to O in order to switch to the black toner developer mode. Then, to stop the copying operation if it is in progress,
A flag F's'r that checks whether the 7-lag FCL indicating that a copy operation is in progress is 1 and stops the copy operation if it is in progress.
is set to 1 (5133, 5134-) and the process ends. Step 5131. If the result of the determination in step 5133 is negative, the process y4 immediately ends. Note that the control for stopping the copying operation by determining the flag F's'r is the same as the stop control when the %° key on the operation panel is pressed.

(6) Drum drying process routine Regarding the drum drying process 31 shown as step Mll in the flowchart shown in FIG.
The details will be explained with reference to the flowchart Ic in FIG.

FIG. 13 shows the processing of the subroutines from state 0 to state 7 adopted in the drum drying process, in which the state number set in each subroutine is determined (steps D101 to D107), the corresponding subroutine (step D108), and the state number set in each subroutine is determined. ~D115) to perform processing.

FIG. 14 is a flowchart of drum tristate 0, which starts the drum drying process. First, it is checked whether the drum dry mode graph FDD is 1 or not (step D121). If the flag is 1, that is, the drum dry mode, the main motor is turned on and the developing bias is turned on.
N (steps DI22 and DI23). It is checked whether or not a copying operation is in progress, and if the copying operation is not in progress, the scanner is returned to the scanning start position (step D124. D1
25). When a copy operation is in progress, step D125 processing is omitted. Set the auto shut state to 0 to prevent the automatic stop operation from starting, and set a delay timer to delay when the transfer charger is turned on.
Set the drum tri-state to work (step D1)
26 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 F'cp is 0 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, it is checked whether the transfer charger ON play timer set in state 0 has finished counting (step D141). If timing has not finished, the process ends, but if timing has finished, the transfer charger is turned ON (step D142). Select whether or not toner supply 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. Also, if it is not the toner supply mode, set a timer that defines 08 hours of transfer charge in drum dry processing, and set the drum state to 5 in step D146. D147), the process ends.

FIG. 16 is a flowchart of drum tri-state 2, in which the ATDC sensor detection start play timer set in state 1 checks the end of time measurement (step D151).
), if the timing has not finished, the process ends, but when the timing 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 counting, and the average value is calculated. , and set the drum tristate to 3 in step D152. D15
3), end the process.

FIG. 17 is a flowchart of drum tristate 3, in which toner replenishment processing is performed. First, check whether the timer that defines the detection time of the ATDC sensor set in state 2 has expired (step D161), and if the timer has not finished counting, the process ends. It is checked whether the content ratio is above a specified value (step D162), and if it is above the specified content ratio, the drum tri-state is set to 6 to end toner supply (step D163), and the process is terminated. In addition, when the toner content ratio is below the specified content ratio, the 7-lag FTcL is used to check whether the toner to be replenished is color or black, and according to the determination, the toner replenishment motor for the color developer 5 or the toner replenishment motor for the black developer 6 is activated. Turn it ON, set the toner replenishment time timer, and set the drum tri-state 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 tristate 4, it is checked whether the timer that defines the toner replenishment time set in drum tristate 3 has timed out (step 171), and if it has not finished, the process ends. , When the timing ends, the toner replenishment motor is stopped, a timer is set to stir the developer in the toner-supplied developer for a predetermined period of time, the developer is operated, and the drum tri-state is set to 5. (steps D172 to D174), and the process ends.

Further, when entering this routine in drum tristate 7, the process moves to step D172.

FIG. 19 is a flowchart of drum tristate 5 and sixth. When this routine is entered in drum tristate 5, toner is replenished to a developing device that is not used for copying during a copying operation.

Since the developer cannot be stirred in the developing device, 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 at drum tristate 5, first, 72. Check F'cp (step D181), and if Fcp 'xz O1, that is, copying is in progress, the agitation time continues to be counted when color toner is replenished in case of color copying, and when black toner is replenished in case of color copying. is replenished, or when color toner is replenished in the case of black copying, judgment is made to end the process without stirring (steps DI82 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 DI85, where the stirring timer is counted and whether the timer has finished counting is determined. If the timing has not finished, the process ends, but when the timing has finished, the drum dry flag FDD and toner flag FTN are turned off.
K is reset, the auto-shut state is set to 1 to start the termination process, the drum tri-state is reset to 0 (steps D186 to D189), and the process ends.

〔Effect of the invention〕

As explained above, this invention selects the developing device that requires rapid toner replenishment with the switch for selecting black copy or color copy, and uses this and the toner agitation function of the drum dry function to switch between the drum dry switch and the number. 0”
Since toner replenishment is instructed by combining switch operations for other purposes, such as by turning on the numeric keypad indicating , there is no need to provide a special switch for rapid toner replenishment.

In addition, it is possible to replenish and agitate toner, making it possible to provide an image forming apparatus with multiple functions at a low cost.

[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=Original table, Swamp, 30=Power set paper feed section. Patent applicant: Minolta Camera Co., Ltd. Figure 7 Figure 9 Figure 10 Figure 14 Figure 16

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;
The present invention is characterized by comprising a means for instructing toner replenishment, and a control means for operating a toner replenishing means provided in a developing device selected by the developing device selecting means when toner replenishment is instructed by the toner replenishing instructing means. image forming apparatus.