JPS6084559A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To enable a toner concn. control operator to confirm whether toner concn. becomes controllable or not each time without measuring time by aging a developer for a prescribed time before controlling toner concn. in an electrophotographic machine. CONSTITUTION:A power supply is turned on, and when it is judged by operating steps B1 and B2, that the toner concn. control is necessary, display is turned into ''no copying'' by steps B4-B7, then, a motor is energized, and aging is executed for a time T1 set in a timer. After the lapse of T1, when a flag becomes 0, ''coyping OK'' is displayed by a step B9. The control is executed here. After the control is finished, and when a stop key is turned on, the motor is stopped. The control can be repeated by turning the start key on. The aging can be executed securely by providing such a flow, and a control executable state can be easily noticed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus such as an electronic copying machine.

[Technical Background of the Invention and Problems Therewith] Generally, for example, an electronic copying machine is provided with a toner concentration control means for always maintaining a constant concentration of toner (developer) in a developing device.

This toner concentration control means is normally in an unadjusted state when the product is shipped. Therefore, it is necessary to make adjustments when the product is installed on the user's side (or during maintenance and inspection). Before performing this adjustment, it is necessary to carry out an aging operation for a certain period of time to agitate the toner in the developing device so that a certain amount of toner adheres to the toner concentration detection sensor. However, conventionally, when performing an aging operation for this purpose, only the aging operation is performed, which requires the adjuster to measure the aging operation time each time, which is extremely inconvenient and troublesome. there were.

[Object of the Invention] The present invention has been made in view of the above circumstances, and its purpose is to not only execute an aging operation for adjusting a developer concentration control means, but also to perform an aging operation. An object of the present invention is to provide an image forming apparatus that allows an adjuster to easily confirm whether or not an adjustable state has been reached without measuring the time each time the image forming apparatus is adjusted.

[Summary of the Invention] The image forming apparatus of the present invention includes an input means for inputting an aging operation command, and a control means for performing the aging operation for a fixed time using a software timer when the aging operation command is input from the input means. By providing this, it is possible to automatically carry out the priming operation for a certain period of time.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an electronic copying machine as an example of an image forming apparatus according to the present invention. That is, 1 is a housing, and approximately in the center thereof is a photosensitive drum 2 that rotates in the direction of arrow a in the figure.
is provided. Further, in the upper part of the housing 1, a document table 3 for supporting a document is provided so as to be able to reciprocate in the direction indicated by the arrow in the figure. By moving the document table 3 in synchronization with the rotation of the photoreceptor drum 2, the exposure lamp 4
The light irradiated from the original is reflected by the original on the original table 3, and the reflected light forms an image on the photoreceptor drum 2 by the convergent light transmitter 5, and is reflected on the photoreceptor drum 2 as an inverted image of the original.

At this time, by charging the photoreceptor drum 2 with the charging device 6, an inverted image of the document is formed on the photoreceptor drum 2 as an electrostatic latent image, and this electrostatic latent image is transferred to the developing unit 7. The image is visualized by adhering toner.

On the other hand, a paper feed mechanism 8 is provided below the developing device 1 to supply the paper P to the lower part of the photoreceptor drum 2 (lit transfer section 12). This paper feeding mechanism 8 is detachably attached to the side of the housing 1 and can feed a plurality of sheets of paper P.

..., and a paper feed row 510 that feeds the paper P one by one from the paper feed cassette 9, and further positions the leading edge of the paper P fed by the paper feed roller 10. A pair of registration rows 511 and the like are provided for conveyance. Here, the paper feed row 510 is configured to store paper P in the paper feed cassette 9, for example.
A contact portion 10a that contacts and a non-contact portion 1 that does not contact
The drive force of the motor is transmitted by turning on a solenoid of a spring clutch for turning the paper feed roller (not shown).

Thus, the paper P conveyed by the registration rollers 11 is sent to the image transfer section 12. The paper P sent to the image transfer unit 12 comes into close contact with the surface of the photoreceptor drum 2 at the transfer charger 13, and at this time, the charger 13 charges the paper P, causing the paper P to be charged on the photoreceptor drum 2. The toner image is transferred. After the transfer, the photosensitive drum 2 is configured such that residual toner on the surface is removed by a cleaner 14, and afterimages are erased by a static elimination lamp 15, so that the photosensitive drum 2 returns to its initial state. On the other hand, the paper P after transfer is
After being electrostatically peeled off from the photoreceptor drum 2 by the action of the peeling charger 16, the transferred image is guided along the conveyance path 17 and passed through a pair of heat rollers 18 as a fixing device, whereby the transferred image is heated and fixed. be done. The sheet P after fixing is configured to be discharged to the tray 20 outside the housing 1 by a pair of paper discharge rows 519.

Note that the photosensitive drum 2, document table 3, developing devices 7, 6-paper feed roller 10, registration roller 11, heat roller 1
8. The paper ejection roller 19 is operated using the motor 21 as a driving source.

Further, a switch (hereinafter referred to as a paper feed switch) 22 is provided near (front) the registration roller 11 as a detector for detecting the paper feeding state, and further near (front) the paper ejection roller 19 is provided. A switch (hereinafter referred to as a paper ejection switch) 23 is provided as a detector for detecting the paper ejection state. Each of these switches is provided primarily to detect paper jams (also referred to as jams).

The housing 1 is divided into two parts, an upper housing 1a and a lower housing 1b, with the transport path 17 as a border, as shown by the two-dot chain line, and both cylinders 1a and 1b are provided at one end. The upper casing 1a is pivoted at a fulcrum (not shown), and can be opened at a predetermined angle in the direction of arrow C in the drawing. Here, the upper housing 1a includes a photosensitive drum 2 and a document table 3.
, an exposure lamp 4, a focusing light transmitter 5, a charger 6, a developer 7, a paper feed roller 10, an upper roller of the registration roller 11, a cleaner 14, a static elimination lamp 15, etc. A paper feed cassette 9, a lower roller of the registration roller 11, a charger 13.1B, a transport path 17, a heat roller 18, a paper discharge roller 19, a tray 20, a motor 21, etc. are provided, respectively.

FIG. 2 shows the document table drive mechanism. That is,
The driving force of the gear 31 directly connected to the motor 21 is transmitted to the electromagnetic clutch 36 via gears 32, 33, 34, 35 for transmitting the driving force. This electromagnetic clutch 36 can be used in three cases according to the control signal: when it does not transmit the driving force to the pulley 37, when it transmits it in the forward direction, and when it transmits it in the reverse direction.
It is designed to perform two switchings. And pulley 3
The driving force transmitted to the document table 7 is transmitted to the document table 3 by a wire 38 whose both ends are fixed to the document table 3, and moves the document table 3. The pulley 39 is provided to ensure that the path of the wire 38 is approximately parallel to the document table 3 so that it does not come into contact with other parts.

3 to 6 show the document table position detection mechanism. That is, as shown in FIG. 3, -
Three magnets Ill at predetermined intervals on a straight line, 42
．． 43 is attached, and two magnets 44 and 45 are attached to both ends thereof with a phase shift. Further, as shown in FIG. 4, the housing 1 includes the magnet 41.
Reed switches 46 and 47 for detecting .about.45 are attached. This reed switch 46 has magnets 41 to 4.
Similarly to the magnets, the reed switch 47 is arranged out of phase so as to detect that the magnet 44, 45 is placed above it, and the reed switch 47 is arranged so as to detect that the magnet 44, 45 is placed above it.

In FIGS. 4 to 6, the position of the magnet 1 detected by the reed switch 46 is P41. P42゜P4
3, and the position of the magnet detected by the reed switch 47 is P44. It shall be P45. FIG. 4 is a diagram when the document table 3 is located at the home position. The home position is the position where the document table 3 is stopped at the end of the copying operation, and as shown in FIG. When the document platen is at the movement stop position (hereinafter referred to as the document platen limit position), which can be detected by turning on the reed switch 46, movement is started in the direction of the arrow in FIG. 4 (hereinafter referred to as backward). The reed switch 46 is turned on by the magnet 43 for the first time.
It is detected when the is turned on. Also, the fifth
The figure shows a state in which the document table 3 is located at the backward movement stop position (hereinafter referred to as the document table start position).

The original platen start position is detected by simultaneously turning on reed switches 46 and 47 by magnets 41 and 44. Furthermore, the reed switch 46 is turned on for the first time after the document table 3 starts moving forward from the document table start position and is no longer at the document table start position, that is, the reed switch 46 is turned on by the magnet 42.
The registration roller start position is detected by turning on. As mentioned above, since the photosensitive drum 2 and the document platen 3 are driven in synchronization, one
0- The timing to start rotating the registration rollers 11 can be determined not from the photosensitive drum 2 but also from the document table 3. The position at which the registration roller 11 starts rotating is the registration roller start position.

Incidentally, the developing device 7 is provided with a sleeve 24 that attracts developer using magnetic poles disposed inside to form a magnetic brush. As the sleeve 24 rotates, the developer acts as a magnetic brush and rotates. The detection probe 25 is disposed so as to be buried in the magnetic brush by about several times, and is configured to rub the toner in the developer onto the surface of the probe while rotating. In this case, the amount of toner scraped off and attached to the surface of the detection probe 25 is proportional to the toner concentration of the developer.

Therefore, the amount of toner on the surface of the detection probe 250 is detected by the toner concentration detector 26, and the detection signal is sent to a toner concentration detection circuit described later. When the toner concentration decreases, the toner is developed by a toner replenishment mechanism (not shown). It is designed to be replenished into the drug. The detector 26 includes a detection probe 2, for example, as shown in FIG.
A light emitting element (for example, a light emitting diode) 26a that irradiates light onto the surface of the detection probe 25 and a light receiving element (for example, a photodiode) 26b that receives reflected light from the detection probe 25.

FIG. 8 schematically shows the overall control circuit.

That is, 51 is a microprocessor as a main control section, which controls the entire copying machine.

The microprocessor 51 is connected to the paper feed switch 22 and the paper ejection switch 23 via an interface circuit 52.
, reed switches 46 and 47 (hereinafter referred to as document table switches), a serviceman switch 53 that cannot be operated by general users, and a key switch 54 such as a numeric keypad provided on the device operation section (operation panel) not shown. , and signals from the toner concentration detection circuit 55 and the like are input. The microprocessor 51 judges and processes the input signals, and outputs various control signals to each control device via the interface circuit 56 according to a pre-stored program. Each control device includes the exposure lamp 4, the motor 21, an electromagnetic clutch (hereinafter referred to as document platen clutch) 36, a paper feed roller solenoid 57 for transmitting a drive horn to the paper feed roller 10, and a charger for charging. 6, a registration roller solenoid 59 for transmitting driving force to the registration roller 11, a high voltage power supply 60 for supplying power to the transfer charger 13 and the peeling charger 16, and the cleaner 1.
There are a blade solenoid 61 for pressing the blade No. 4 against the photosensitive drum 2, a toner replenishment solenoid 62 for driving a toner replenishment mechanism (not shown), a display device 63 for displaying information such as whether or not a copying operation is possible and a paper jam. Each operates according to a control signal.

The microprocessor 51 is configured as shown in FIG. 9, for example. That is, the microprocessor 51 is a one-chip microprocessor having an architecture as shown in FIG.

In the figure, 11 is an arithmetic unit (ALLI) having an arithmetic judgment function.
, 72 is a read-only memory (ROM) for storing processing programs, 73 is a random access memory (RAM) for storing data, and 74 is an input/output port for transmitting and receiving signals with external devices. and human output control unit (IOC), 75 is a program counter (PC), 7
6 is a flag (FLAG), 77 is an accumulator (AC
C), 78 is a stack register (STACK>), and 79 is an interrupt control unit (ING).

Here, to briefly explain the operation of the microprocessor 51, the address of the processing program stored in the ROM 72 is designated by the PC 75, and the address of the processing program stored in the ROM 72 is specified.
The instruction read from 2 is decoded and executed. FLAG 76 stores the state of carry, borrow, etc. of the result of arithmetic determination. The calculation result is
The data is stored in the RAM 73 via the ACC 77 or according to instructions.

5TACK 78 specifies the depth of the subroutine, stores the return address of the main routine, and is also used to save the contents of the PC 75 at the time of an interrupt. INTC7
When 9 requests an internal interrupt or an interrupt from the external terminal (INT>), at that point 14- ends the instruction being executed and enters interrupt processing.When interrupt processing begins, the contents of PC75 are transferred to 5TACK78. evacuate,
Jump to a specific address for interrupt processing.

Execute the interrupt processing program and then return to the main program.

FIG. 10 shows the toner concentration detection circuit 55. That is, the resistors 81 to 83 and the transistor 84
The circuit constituted by is a drive circuit for the light emitting diode 26a constituting the detector 26, and performs temperature compensation to keep the light emitting output of the light emitting diode 26a constant. That is, as the ambient temperature decreases, the light emitting output of the light emitting diode 26a increases, but since the voltage between the base and emitter of the transistor 84 increases, the light emitting diode 26a increases.
The current flowing through the light emitting diode 26a becomes smaller, and the light emitting output of the light emitting diode 26a becomes constant. Conversely, as the ambient temperature rises, the light emitting output of the light emitting diode 26a decreases, but the voltage between the base and emitter of the transistor 84 decreases.
The current flowing through the light emitting diode 26a increases, and the light emitting output of the light emitting diode 26a becomes constant.

Now, when light is irradiated onto the surface of the detection probe 25 from the light emitting diode 26a, the light is reflected according to the amount of 1-ner adhering to the surface of the detection probe 250, and the reflected light is directed to the photodiode 26b. The optical signal is converted into an electrical signal. This weak photocurrent is transferred to the capacitor 8
5. While being integrated by an integrating circuit consisting of a resistor 86, a capacitor 87, and a resistor 88, the signal is amplified by an operational amplifier 89, and is converted into a voltage to generate an output voltage (1) at its output terminal. This output voltage V1 is changed by adjusting the variable resistor 90. Therefore, the output voltage V1 of the operational amplifier 89 is sent to the comparator 91.
2, compared with V3. When the toner concentration of the developer decreases due to copying, the amount of toner adhering to the detection probe 25 decreases, and the amount of light reflected on the surface of the detection probe 25 increases, causing the photodiode 26
Since the amount of light received by b increases, the photocurrent flowing through the photodiode 26b increases, and the output voltage 1 of the operational amplifier 89 increases. Then, the output voltage v of the operational amplifier 89
When the relationship between V1 and the reference voltage V3 becomes Vl>V3, the output of the comparator 92 becomes low level, the light emitting diode 96 lights up, and a toner replenishment signal is outputted through the resistor 91.

Note that the light emitting diode 98 is used to adjust the variable resistor 90, and when the toner concentration is normal, the toner attached to the surface of the detection probe 25 remains connected to the sleeve 24 and the detection probe for a certain period of time until it becomes proportional to the toner concentration. probe 2
After rotating the light emitting diode 98, adjust the variable resistor 90 so that Vl > V3 and Vl < V2.
lights up. As a result, this toner density detection circuit can always output a toner replenishment signal when the toner density is lower than the normal toner density, thereby maintaining the toner density at the normal density.

FIG. 11 is a general flowchart of a general copying machine. The initial check is a routine that checks whether the state is ready for copying, and for example, the heat 0-
It is checked whether the temperature of the roller 18 is at a temperature that allows heat fixing. After this initial check is completed, if the state is ready for copying, the process moves to a copying standby routine 17-. Here, the routine sets the number of copies and continues until the copying switch is turned on and the copying operation is started. When the copying operation starts, the aforementioned electrostatic charge,
Copying is performed by sequentially executing a copying process consisting of exposure, transfer, static elimination, fixing, etc., and the copying operation is repeated until a set number of copies are completed. Also, during copying operations, checks are made for abnormalities such as paper jams.

Further, control during copying operation will be explained using the flowchart shown in FIG. When the copying operation is started, the process proceeds to step A1, where the blade solenoid 61 and the motor 2 are activated.
1. Static elimination lamp 15, high voltage power supply 60 (charger 13.16
), and proceed to step A2. In step A2, it is determined whether or not the document table 3 is at its start position based on the signal from the document table switch 46, 41. If it is not at the start position, the process advances to step A31, in which a control signal is sent to the document table clutch 36. Then, the document table 3 is moved backward, and the process proceeds to step A4. In step A2, if the original platen 3 is at the start position, step 18--jumps A3 and proceeds to step A4. Step S
In step 4, the document table 3 is moved until it reaches the document table start position, and when the document table switches 46 and 47 are both turned on and the document table start position is detected, the process proceeds to step A5. In step A5, a control signal is sent to the paper feed roller solenoid 57 to rotate the paper feed roller 10, and at the same time, the exposure lamp 4 is turned on, and the process proceeds to step 86. Step 86
Now, send a control signal to the document platen clutch 36 to move the document platen 3.
is moved forward and the process proceeds to step A7. In step A7, the high voltage power supply 58 (charger 6) is turned on, and the process proceeds to step 88. In step 88, the aforementioned registration roller foot position is determined, and the process proceeds to step 80. In step A9, a control signal is sent to the registration roller solenoid 59 to rotate the registration roller 11, and in step A
Proceed to step 10. In step A10, it is determined whether the document table 3 has moved to the document table limit position detected when only the document table switch 47 is turned on, and if it has moved, the process proceeds to step A11. In step A11, the high voltage power supply 58 is turned off, and the process proceeds to step AI2. Step A1
In step 2, a control signal is sent to the document table clutch 36 to move the document table 3 backward, and the process proceeds to step A13. In step A13, the exposure lamp 4 is turned off, and in step A13, the exposure lamp 4 is turned off.
Proceed to step 14. In step A14, it is determined whether or not the document table 3 has moved to the home position detected by the document table switch 46, and if it has moved, the process advances to step A15. In step A15, it is determined whether or not copying of the set number of sheets has been completed. If not, the process returns to step A4 and the above-described copying operation is repeated; if it has been completed, step A16 is performed.
Proceed to. In step A16, a control signal is sent to the document table clutch 36 to stop the document table 3, and the process proceeds to step A17. In step A17, it is determined based on the signal from the paper ejection switch 23 whether or not the copied paper P has been completely ejected, and when the ejection has been completed, the process proceeds to step A18. In step A18, the high-voltage power supply 60, the static elimination lamp 15, the motor 21, and the blade solenoid 61 are turned off to complete the copying operation and enter the copying standby state shown in FIG. 11.

In addition, in controlling the copying machine of the present invention, the microprocessor 5
1 internal interrupt is used. This interrupt processing is set to be repeated at a constant period. To explain this using FIG. 13, when the power is turned on, the RO
The main program among the programs stored in M72 is being executed. However, for example, by setting the INTC79 so that an internal interrupt is generated every 12m5eC from the start of the copying operation, the main program will be temporarily interrupted and the interrupt program will be interrupted when 12msec has elapsed from the start of the copying operation. The main program will now be executed and the main program will be executed again after the interrupt program ends. Furthermore, when 1211 seconds have passed,
In other words, the program flow is such that the interrupt program is executed 24 m5 ec after the start of the copying operation.

FIG. 14 is a flowchart for adjusting the toner density control means. Step B1 when the power is turned on
Then, it is determined whether the serviceman switch 53, which cannot be operated by a general user, is turned on (21-). Here, if the serviceman switch 53 is off, it is assumed that a general user is using the machine, so the process proceeds to step B3, where a normal copying operation as shown in FIGS. 11 and 12 is performed. In addition, in case the adjuster forgets to turn off the serviceman switch 53 or does not perform the adjustment, even if the serviceman switch 53 is on, the key switch 54 of the operating section is set to [0], for example, in step B2. key and “
5" key is pressed at the same time, and if no operation is performed, proceed to step B.
3 to avoid confusing general users. By performing the above two operations correctly,
The adjustment program of steps 84 to B14 is executed.

First, in step B4, a message indicating that copying is not allowed is displayed, indicating that it is not the time for adjustment. Then, in step B5, the motor 21 is rotated to rotate the sleeve 24 of the developing device 7, the detection probe 25, etc., thereby causing aging. The probe 25 detects this aging operation.
22- Time considered necessary for the amount of toner adhering to the surface of the developer to become stable in proportion to the toner concentration of the developer 11
When this is done, a message indicating that copying is possible, which means that adjustment is possible, is displayed. That is, in step B6, the RAM
A value corresponding to time T1 is set in a timer set at a certain address of 73. Then, in step B7, a flag (FLAG) is set to "1", and a timer is started to count in an interrupt process to be described later. The flag is cleared to rOJ after approximately time T1 has elapsed since the timer started counting. This is determined in step B8, and the process proceeds to step B9, where a display indicating that copying is possible is performed. When copying is possible, that is, adjustment is possible, and the toner concentration in the developer is normal, the variable resistor 90 is adjusted as described above so that the light emitting diodes 96 and 98 are lit. In case this adjustment is completed, if it is determined in step B10 that the stop key on the operating section is turned on, the aging operation is stopped, and in step B11, a display indicating that adjustment is not possible and that copying is not possible is displayed. The motor 21 is stopped in step B12. In addition, in order to perform the adjustment again, if it is determined in step B13 that the start key on the operation unit has been turned on, the program shown in the flowchart of FIG. 15 will be executed during the interrupt processing. Therefore, it is possible to know the progress of a predetermined time (T1 here. In other words, when the flag is set to "1" in step B7 of FIG. Determine that and step C
Proceed to step 2. In step C2, a value obtained by subtracting "1" from the timer value set in the RAM 73 is set in the timer again. As mentioned above, interrupt processing is performed in a fixed time, so if that time is t, then T1/l+1
By setting the value in the timer, approximately time T1 has elapsed when the timer value reaches "O". It is determined in step C3 when the value of this timer becomes "0", and the flag is cleared to "0" in step c4. As a result, the determination at step B8 in FIG. 14 becomes a determination that T1 has elapsed.

With the configuration as described above, general users can perform the 1-ging operation to adjust the toner density control means.
In other words, there is no risk of performing an aging operation to adjust the variable resistor 90 of the toner concentration detection circuit 55 shown in FIG. You can easily check whether it is possible.

[Effects of the Invention] As described in detail above, according to the present invention, for example, the adjuster not only executes the aging operation for adjusting the developer concentration control means, but also allows the adjuster to perform the aging operation each time the aging operation is performed. Therefore, it is possible to provide an image forming practice that allows you to easily check whether or not the adjustable state is reached without measuring the time.

25-

[Brief explanation of drawings]

The drawings are for explaining one embodiment of the present invention, and FIG. 1 is a schematic longitudinal sectional front view of an electronic copying machine, FIG. 2 is a side view showing the document table drive mechanism, and FIGS. The figure is a diagram for explaining the document table position detection mechanism, Figure 7 is a diagram showing the relationship between the sleeve of the developer, the detection probe, and the toner concentration detector, and Figure 8 is a diagram schematically showing the overall control circuit. Block diagram, Fig. 9 is a block diagram of the microprocessor, Fig. 10 is a block diagram of the toner concentration detection circuit, Fig. 11 is a general flowchart of a general copying machine, Fig. 12 is a flowchart of copying operation, Fig. 13 14 is a flowchart of a program including microprocessor interrupts, FIG. 14 is a flowchart for adjusting the toner density control means, and FIG. 15 is a flowchart of interrupt processing. 2... Photosensitive drum, 3... Document table, 4... Exposure lamp, 7... Developing device, 8... Paper feeding mechanism, P...
paper, 12... image transfer section, 21... motor, 24...
...Sleeve, 25...Detection probe, 26...Toner concentration detector, 51...Microprocessor (main control unit), 53...Serviceman switch 26- switch, 54...Key switch , 55... Toner concentration detection circuit, 63... Display device, 90... Variable resistor for adjustment. Applicant's agent Patent attorney Takehiko Suzue 27- Figure 11 Figure 12 (a) 了157I哩帖7'L-) ``Runoid Ding,〉 7-ta 7〉 ηstyle艷ヲ;Buin A1 娶''! l A Staple stack? NO Original table / :'-7ノ7''''l'' A34 No 2 ter. Ruin! 9 ES 卆子JNrollasoshinoidoni ≧shirayu7'f> AS original 16 unit million words ゛A5 'PtL7f"1vEiT>A7 8 NO: +°z Doloras, tart kusu 1"' ES JiZ) t7- Lanretoid t-A9 Fig. 15-qAζ-

Claims (6)

[Claims] (1) an image forming means for forming a latent image on an image support; a developing device for developing the latent image formed by the image forming means with a developer; and an input means for inputting an aging operation command;
An image forming apparatus comprising: a control means mainly composed of a microprocessor that causes the aging operation to be performed for a certain period of time using a software timer when an aging operation command is input from the input means. (2) The image forming apparatus according to claim 1, wherein the aging operation is an aging operation of a developing device. (3) At the end of the aging operation for a certain period of time, a display indicating that the developer concentration control means that automatically controls the concentration of the developer in the developing device is ready for adjustment is displayed, and the aging operation is further continued. An image forming apparatus according to claim 2, characterized in that: (4) The input means is comprised of a switch that cannot be operated by a general user and a key switch of the device operation section, and the aging operation command is input by a combined operation of these switches. range 1
The image forming apparatus described in Section 1. (5) The image forming apparatus according to claim 1, wherein the input means is a switch that cannot be operated by a general user. (6) The image forming apparatus according to claim 1, wherein the input means is a key switch of an apparatus operation section.