JP2517165Y2 - Image forming device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION This invention is applied to, for example, two colors.
It has two developing devices that can perform development.
The present invention relates to an image forming apparatus capable of forming an image of two colors on one original by selecting a color that is out of alignment.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as an electronic copying machine has two developing devices capable of developing two colors .
Some of these developing devices can be used individually to obtain an image of a single color but different colors.

In an image forming apparatus having such two developing devices, when a certain color is selected to form an image and then another color is selected to form an image, the developing devices are switched. There is a need. This developing device switching operation requires a predetermined time, but if the start of an image forming operation is instructed during this developing device switching operation, the developing device does not operate normally and the desired image is formed. There was a problem that I could not do it.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems , the present invention uses two current developing methods capable of developing two colors.
In those with an imager, the developer selection operation is not performed.
The image forming operation can be prohibited while the
An object of the present invention is to provide an image forming apparatus that can be reliably performed .

[0005]

SUMMARY OF THE INVENTION An image forming apparatus of the present invention contains a latent image on an image carrier which contains a developer of a first color.
Developing device for developing the first color with the first color
On the image carrier, which contains the developer of a different second color
Second developing device for developing the latent image of
And select one of the second developing devices
Selection means, to uniformly charge the surface of the image carrier, and then
The exposure scanning of the
An image is formed on the image carrier, and the selection procedure is performed for this latent image.
The first developing device or the second developing device selected by the stage.
The developer of the first color or the second color is supplied by an imager.
To develop the image, and to develop the image.
After the image on the holder is transferred onto paper, it is fixed at a specified temperature
Paper by performing a series of image forming operations
An image forming means for forming an image on the image forming means,
Show ready and not ready
Display means, and the first developing device or the second developing device.
When one of the developing units is selected
In the state, the other developing device is selected by the selecting means.
If selected, the motion to move the selected developing device.
While the work is being performed,
It is prohibited to execute a series of image forming operations and
The image forming means cannot operate with respect to the display means.
Is displayed to move the selected developing device.
When the work is completed, the fixing temperature of the image forming means is set to a predetermined value.
If the temperature is not higher than the temperature, the image is formed on the display means.
The operation is inoperable and the display continues and the above is selected.
Image formation when the operation of moving the developing device is completed
If the fixing temperature of the means is above a predetermined temperature,
In contrast, display that the above image forming operation is possible.
It is composed of control means .

[0006]

The present invention can be applied to one image forming device during one image forming operation.
For mono-color twin-color copiers that use only imagers
Select one of the two developing devices
Means for selecting the presently selected by this selecting means.
A developing device different from the image device is selected
Copying is disabled while the developing device is being moved
Is displayed and the fixing temperature after the selection operation is
If the temperature is above a certain temperature, it will be displayed as a copy ready state.
This is what is shown.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 illustrates an image forming apparatus of the present invention, for example, an electronic copying machine.

That is, in the figure, 1 is a copying machine body having a built-in copying mechanism, 2 is a paper feed cassette mounted on the right side surface of the copying machine body 1, and 3 is a paper discharge mounted on the left side surface of the copying machine body 1. It's a tray. Further, a document table 4 which is reciprocally movable in the left-right direction (direction of arrow a) is provided on the upper surface of the copying machine body 1, and an operation panel (not shown) is provided on the front end edge of the upper surface of the copying machine body 1. Has been.

The original table 4 has an original placing plate (glass plate) 12 on which an original is placed and an original cover 13 covering the upper surface thereof. The cassette cover 14 of the paper feed cassette 2 serves as a manual paper feed tray 15 for manually feeding the paper P1 as needed.

Reference numeral 20 in the figure denotes a drum-shaped photoconductor disposed substantially in the center of the copying machine main body 1. The photoconductor 20 is driven by a drive mechanism (not shown) in the direction of arrow b in synchronization with the document table 4. To be done. First, a document image uniformly charged by the charger 21 and uniformly irradiated by the exposure lamp 22 is focused on the light transmitting body (product name: SELFOC lens array) 2
3 forms an electrostatic latent image formed on the photoconductor 20.

The electrostatic latent image formed on the photoconductor 20 is selected by a developing mechanism (not shown).
1 or 242 to make a toner image Transfer charger 2
It is sent to the 5 side. The developing device 241 carries out black developing, and the developing device 242 carries out red developing.

The paper P or P'which is automatically or manually fed is fed by the paper feeding device 26, and the toner image previously formed on the photoconductor 20 is transferred onto the paper P or P'by the transfer charger 25. . Further, the toner is peeled off from the photoconductor 20 by the peeling charge 27 due to AC corona discharge, passes through the conveying path 28, and the toner image is fused and fixed on the paper P (P ′) by the fixing device 29, and detachable by the discharge roller 30. It is discharged to the tray 3.

On the other hand, the residual toner remaining on the photoconductor 20 after the toner image is transferred onto the paper P (P ') is cleaned by the cleaning device 31.
Then, the electric charge on the photoconductor 20 is lowered to a certain level or lower by the neutralization lamp 32, and the next copying operation is possible. Further, 33 is a fan as a cooling device, which exhausts heat generated by the heat generating portion exposure lamp 22 and the fixing device 29 in the machine.

An upper frame (not shown) and a lower frame (not shown) are pivotally supported in the copying machine main body 1 at one end via a support shaft 37 so that the other ends of both frames can be opened at a desired angle, for example, 30 °. Is configured.

Each device such as a charging charger 21, a converging optical transmission member 23, an exposure lamp 22, a developing device 24, a cleaning device 31, and a discharging lamp 32 is attached to the upper frame around the photoconductor 20 by appropriate means. In addition, the fan 33 as a cooling device, the paper feed roller 38 of the paper feed device 26, and the document table 4 are also mounted on the frame to form the upper unit 1A.

Further, the paper feed cassette 2,
Transfer charger 25, peeling charger 26, transport path 2
8, the forming guide plate 39, the fixing device 29, the discharge roller pair 30, each mechanism such as the tray 3, the main motor (DC brushless motor) 35, and the power supply unit 34 are attached by appropriate means to configure the lower unit 1B. are doing.

The front cover 1 of the copying machine main body 1
After a is rotated and removed, it can be opened and closed substantially along the conveyance path 28 of the paper P (P ') via a housing opening / closing device (not shown). Therefore, even when the paper P (P ') is jammed on the transport path 28, it can be easily taken out.

In FIG. 1, reference numerals 50 and 50 denote paper feed cassettes 2.
In addition to correcting the inclination of the front end surface of the paper P automatically fed from the inside or the paper P ′ manually fed,
Reference numeral 51 denotes a registration roller pair that supplies the sheet P or P ′ toward the transfer charger 25 in synchronism with the toner image forming operation for 0, and 51 denotes a pair of registration rollers 50 and 5.
It is a manual feed detection switch arranged immediately before 0.

Reference numeral 52 is a paper discharge switch, 53 is a total counter, 54 is a paper empty switch for detecting that the paper P in the paper feed cassette 2 has run out, 551, 5
52 is a doctor for controlling the thickness of the developer layer of the developing devices 241, 242, 561 and 562 are toner hoppers, 571,
Reference numeral 572 is a toner-free detector as detection means, 581,
Reference numeral 582 is a toner concentration detector, and 591 and 592 are lids of the hopper, and the original table 4 cannot be moved unless these are closed.

Reference numeral 60 is a high-voltage transformer, 61 is a static elimination brush, 62 is a handle formed for opening and closing the upper unit A, 63 is a reflector surrounding the back of the exposure lamp 22, and 64 is an auxiliary reflector.

Further, reference numeral 65 is a weight for bringing the cleaning blade 66 of the cleaning device 31 into contact with the photoconductor 20 at a constant pressure.

The no-toner detector 571 is a moving body 411 that rotates according to the amount of toner in the toner hopper 561.
Magnet 421 and toner hopper 5 provided at the tip of the
And a reed switch 431 provided outside 61. In addition, the toner-free detector 572 is also provided with the magnet 4 provided at the tip of the moving body 412 as in the above.
2 2 and a reed switch 43 2 provided outside the toner hopper 56 2. In addition, the reflector 63, the auxiliary reflector 64, and the converging optical transmission body 23.
Are assembled as one unit.

Further, the paper feeding device 26 provided on the lower right side of the copying machine main body 1 leaves the paper feeding cassette 2 and the paper take-out opening provided with the separating claw on the upper surface side of the paper feeding cassette 2. The paper feed roller 15 is formed on a cassette cover that covers the paper, and a paper feed roller 38 for taking out and feeding the paper P in the paper feed cassette 2.

FIG. 2 shows the operation panel 71, which has a copy key 72 for executing a copying operation, a ten key 73 for setting the number of copies, a function for clearing the set number and a function for stopping the copying operation. A clear / stop key (C / S key) 74 is provided, a number display section 75 for displaying the number of remaining copies subtracted from the set number during the copying operation, and a liquid crystal display section 7 for displaying an operating state and a selection state of copying conditions.
6. Switching between the plurality of developing devices 241 and 242, that is, switching between the first mode for forming an image in black (first color) or the second mode for forming an image in red (second color) A color selection switch 77 for performing, a volume 78 for adjusting the exposure amount and setting the image density, and the like are provided. FIG. 3A is a layout view of segments that form a schematic figure of the copying machine displayed on the liquid crystal display unit 76 by a liquid crystal display element.

That is, 80 is a liquid crystal display panel, 81,
Reference numeral 82 denotes a pictogram display segment indicating whether or not copying is possible. The segment 81 alone can be copied.
82 indicates that copying is not possible (during warm-up). 8
31 is a pictorial representation of the hopper of the developing device 241, which is a pictogram display segment indicating that the developing device 241 has been selected. The color of the image obtained by this developing device 242, for example, black, is displayed in white. Has become.

Actually, the back of the liquid crystal display panel is black, and the display 832 is displayed in white as shown in FIG. 3 (b). Reference numeral 832 is a graphic representation of the hopper of the developing device 242, which is a pictogram display segment indicating that the developing device 242 is selected, and is selected by displaying the color of the image obtained by the developing device 242, for example, red. It is designed to display colors.

Numerals 841 and 842 are pictogram display segments indicating that the toners in the toner hoppers of the developing units 241 and 242 are exhausted, and numeral 85 is a pictogram indicating that the collected toner is full in the collected toner storage portion. A display segment 86 is a pictogram display segment indicating that a paper jam has occurred in the fixing device 29 or a transport path in the vicinity thereof.

Reference numeral 87 is a pictogram display segment indicating that the paper P is wound around the photoconductor drum 20 or the cleaning device 31 or paper jam has occurred due to the paper P, and 88 is a pictogram display segment indicating an instruction to call a key operator,
Reference numeral 89 is a pictogram display segment indicating an instruction to call a service person, and 90 to 93 are pictogram display segments indicating a conveyance state of the paper P.

Reference numeral 94 is a pictogram display segment indicating that the paper P in the paper feed cassette 2 is exhausted, 95 is a pictogram display segment indicating that the paper feed cassette 2 is inserted, and 96 is the copying machine main body. 1 is a lower cover display segment, 97 is a closed upper cover display segment, and 98 is an open upper cover display segment 99 is a display segment of the photosensitive drum 20. Although not shown, a common electrode is provided on the surface facing the above segments.

FIG. 4 shows the overall construction of the copying machine. That is, 100 is a main control unit including a microcomputer or the like, which includes the operation panel 71.
Input unit (various keys 72 to 78) and various detector groups 101 (for example, toner empty detectors 571 and 572) are connected via an input interface 102.

The main control section 100 controls the operation of the entire copying machine. The static elimination lamp 32, the main motor 35, the blade solenoid 104 for driving the cleaning blade 66, and the document table 4 are controlled by the driver 103.
Table forward solenoid 105 for moving the
Table back solenoid 10 for moving the document table 4 back
6, sheet feeding roller solenoid 107, registration roller solenoid 108, toner supply solenoids 109 and 110,
And the developing device control circuits 111 and 112.

The paper feed roller solenoid 107 and the registration roller solenoid 108 are respectively the paper feed roller 38.
And to rotate or stop the registration rollers,
The spring clutch between the drive source and each roller is operated or stopped.

The toner supply solenoids 109 and 110 are
The toner concentration detectors 581 and 582 respectively detect that the toner concentration is less than the specified value, and the developing unit 24
The toner is replenished from the toner hoppers 561 and 562 in the first and second 242, respectively.

The developing device control circuits 111 and 112 select the developing devices 241 and 242, respectively, and drive-control them to bring the corresponding developing devices into contact with or separate from the photoconductor 20. The developing device control circuits 111 and 112 are selectively driven by switching the color changeover switch 77.

The main control unit 100 also includes a lamp regulator 113, a heater control circuit 114, and a high voltage transformer 1.
The number display circuit 117 is connected through the driver 15 and the driver 116. The lamp regulator 113 controls energization of the exposure lamp 22. The high-voltage transformer 115 applies a voltage to the charger 21, the transfer charger 25, the peeling charger 27, etc. according to the control signal.

The heater control circuit 114 includes the fixing device 2
The temperature of the fixing heater 119 is controlled to be a fixing possible temperature. The number display circuit 117 is adapted to perform a display operation by selectively turning on the LED segment of the number display unit 75.

Further, the main control section 100 converts each state of the copying machine into a binary code signal of [1, 2, 4, 8] and outputs it from the output terminal OD, and from the output terminals OL and OC. It outputs a latch signal and a clock signal, respectively. The data signal from the main control unit 100 is input to the input terminal ID of the liquid crystal drive circuit 120 in synchronization with the clock signal of the input terminal IC.

The oscillating circuit 121 oscillates at the optimum frequency for driving the liquid crystal, and the drive pulse A from the output of the oscillating circuit 121 and the drive pulse B which is inverted by the inverter circuit 122 are generated to produce the liquid crystal. It is input to the drive circuit 120.

The outputs of the output terminals O1 to O32 of the liquid crystal drive circuit 120 are supplied corresponding to the segments S1 to S32 of the liquid crystal display element provided in the liquid crystal display panel 80, respectively. To the common electrode 123 provided facing S32 to the inverter circuit 122.
Output, that is, the drive pulse B is supplied.

The segments S1 to S32 are shown in FIG.
The respective segments 81 to 99 of (a) are shown and correspond as shown in Table 1 below. In addition, segment 96,
99 is connected to the same segment S16.

[0041]

[Table 1]

FIG. 5 shows the liquid crystal drive circuit 120 in detail. That is, the shift registers 1311 to 1
The reference numeral 3132 is continuously connected, and the data signal from the input terminal ID is input to the shift register 1311 at the first stage, and the clock signal from the input terminal IC is input to each of the shift registers 1311 to 13132.

As a result, the data signal from the input terminal ID synchronizes with the clock signal from the input terminal IC 32.
The shift registers 1311 to 13132 are sequentially transferred. Each of the shift registers 1311
To 13132 are store registers 1321 to hold respective contents of the latch signals from the input terminal IL.
13232 are directly connected to each other. Each of the store registers 1321 to 13232 selectively outputs the drive pulse A or B to the output terminals O1 to O32 by controlling the opening / closing of the switches 1331 to 13332 according to the contents held therein. That is, for example, opening / closing control is performed so that the drive pulse A is output to the corresponding output terminal when the content of the store register is "1" and the drive pulse B is output when the content is "0".

Next, the operation of the above structure will be described with reference to FIGS. 6 to 20. Note that FIG.
FIGS. 9, 12, 15, and 18 are timing charts, and FIGS. 7, 10, 13, 16, and 19 are voltage waveforms applied to the liquid crystal display panel 80. FIGS. 14, FIG. 17, and FIG. 20 show display examples. First, a case where the power switch (not shown) is turned on and the copying is not possible (standby state) will be described with reference to FIGS. 6 to 8.

In FIG. 6, when a power switch (not shown) is turned on at time t0, the main controller 100 starts the operation according to a preprogrammed program and energizes the fixing heater 119 of the fixing device 29.

Further, at this time, the fixing device 29 has not reached the fixable temperature yet and is in a standby state. Further, when the power is turned on, the black developing device is automatically selected. A data signal indicating that the standby state and the black developing device are selected, for example, [0010000000
0001011011000000000000] is output to the output terminal OD.

In this case, the data signal A is output in synchronization with the clock signal output to the output terminal OC, and the last 3
Output terminal OL when the second bit data transfer is completed
To output a latch signal.

As a result, the data signals A are held in the store registers 1321 to 13233 in the liquid crystal drive circuit 120, and the contents of the store registers 1323, 1324, 13216, 13217, and 1321 are "1".
9, 13220 and corresponding output terminals O3, O14, O16, O1
A drive pulse A is output from 7, O19 and O20, which becomes a segment drive signal and is applied to each segment S3, S14, S16, S17, S19, S20 of the liquid crystal display panel 80.

Further, the store registers 1321, 1322, 1324 to 13213, 13 whose contents are "0" are
215, 13218, 13221 to 13232 and the corresponding output terminals O1, O2, O4 to O13, O15, O18, O21 to O32 output a drive pulse B, which becomes a segment drive signal of the opposite polarity and becomes the liquid crystal display panel 80. Is applied to each segment S1, S2, S4 to S13, S15, S18, S21 to S32.

At this time, the common electrode 123 of the liquid crystal display panel 80 and each segment S3, S14, S16, S17, S19,
A voltage having an AC waveform as shown in FIG. 7F is applied between S20 and S20. As a result, the segments S3, S14, S16, S17,
S19 and S20, that is, the segments 831 and 9 of FIG.
5, 96, 97, 81, 82 and 99 are in a lighting state.

On the other hand, other segments S1, S2,
In S4 to S13, S15, S18, S21 to S32, FIG.
Since a voltage in phase with the common electrode 123 is applied as in (c) and (e), there is no potential difference between them as in FIG. 7 (g), and therefore the segments S1, S2, S4 to S1 are not present.
3, S15, S18, S21 to S32, that is, the respective segments 832, 842, 841, 85 to 94, 98 in FIG.

Therefore, the display in this case is as shown in FIG. 8, which indicates that the developing device for black is selected in the standby state. The black developing device is selected as the normal priority mode. In this case, the segment S3 (83
1) is displayed in reverse with respect to the black color of the back, as shown in FIG. Next, a case where copying is possible after the standby state and the black developing device is selected in this state will be described with reference to FIGS. 9 to 11.

In the state where the temperature of the fixing device 29 has reached a temperature at which fixing can be performed, the color selection switch 77 has been activated since the power was turned on.
Is not operated or the color selecting switch 77 is operated to complete the black developing device selecting operation (the copying operation is not performed from the time the color selecting switch 77 is operated until the developing device selecting operation is completed). When the copying operation is possible, a data signal indicating this state, for example, a data signal (00100000000001011010000000000000) from the main control unit 100 (hereinafter referred to as data signal B) is possible. Is output by the same operation as described above.

As a result, the store registers 1321 to 1321-13
The data signal B is held in 232 so that the contents of the store registers 1323 and 132 are "1".
The drive pulse A is output from the output terminals O3, O14, O16, O17 and O19 corresponding to 14, 13216, 13217 and 13219, and the corresponding segment S3, S14 and S1.
6, S17 and S19 are applied.

Further, the store registers 1321, 1322, 1324 to 13213, 13 whose contents are "0" are
215, 13218, 13220 to 13232 and the corresponding output terminals O1, O2, O4 to O13, O15, O18, O20 to O32 output drive pulses B, which correspond to the respective segments S1, S2, S4 to S13, S15. , S18, S20 ~ S32
Is applied to

At this time, since the drive pulse B is applied to the common electrode 123 as described above, the space between the common electrode 123 and the segments S3, S14, S16, S17 and S19 is as shown in FIG. A voltage with a different AC waveform is applied. As a result, the segments S3, S14, S16, S17, S19, that is, the respective segments 831, 95, 96, 97, 8 of FIG.
1 is turned on.

On the other hand, segments S1, S2,
In S4 to S13, S15, S18, S20 to S32, FIG.
Since a voltage in phase with the common electrode 123 is applied as in (c) and (e), the segments S1, S2, S4 to S13,
S15, S18, S20-S32, that is, each segment 82, 832, 842, 841, 85-94, 98 of FIG.
Turns off.

Therefore, the display graphic in this case is shown in FIG.
It becomes like this, and the segment S3 together with the schematic figure of the copier
By highlighting (831) in white with respect to the black color of the background, it is displayed that the black developing device is selected and the copying operation is ready.

Next, the case where the red developing device is selected and the copying operation is possible will be described with reference to FIGS.
This will be described with reference to FIG. By operating the color selection switch 77, the selection operation of the red color developing device is completed.

In this embodiment, the black developing device is positioned higher than the red developing device, and when the power is turned on or after the red developing device is selected, nothing is operated for a fixed time (for example, 1 minute). If not, the black developing device is automatically selected, so that the color selecting switch 77 must be operated in order to select the red developing device.

By the way, as described above, the color selection switch 7
When 7 is operated, the copying operation cannot be performed until the developing device selecting operation is completed. Therefore, the display is performed until the selecting operation is completed. As in the case of No. 2, since the red developing device to be described below is selected and only the segment S20 (82) is turned on in addition to the display when the copying operation is possible, the description thereof will be omitted.

When the copying operation becomes possible, the main control unit 100 outputs a data signal indicating this state, for example, [10
000000000001011010000000000000] is output (hereinafter referred to as data signal C).

As a result, the same operation as described above is performed, and the common electrode 123 and the segments S1, S14, S16, S17, S19.
AC voltage is applied only between the segment and that segment, that is, each segment 832, 95, 96 of FIG.
97 and 81 are turned on, and the other segments, that is, the segments 82, 831, 841 and 841, in FIG.
842, 85-94, 98 are in a non-lighting state.

Therefore, the display figure in this case is shown in FIG.
And the segment S along with the schematic figure of the copier.
By displaying 1 (832) in red, it is indicated that the red developing device is selected and the copying operation is ready.

Next, a case where the black developing device is selected and the toner-free detector 571 detects that the toner in the hopper 561 of the black developing device 241 is exhausted will be described with reference to FIGS. 11, and FIG. 15 to FIG. 17 will be described.

When the toner-free detector 571 detects the toner-free state (the copying operation is still possible when the toner is simply removed from the hopper 561), the main control section 100
As a data signal indicating this state, the data signal B [001000
[00000001011010000000000000] and a signal for lighting the segment S4 (841) to the above data signal B [00
110000000001011010000000000000] and alternately outputs a data signal (hereinafter referred to as data signal D) in synchronization with the frequency of the oscillation circuit 121.

As a result, when the data signal B is output, only the segments S3, S14, S16, S17, S19,
That is, the segments 831, 95, 96, 9 of FIG.
When the data signals D are output, the segments S3, S4, and S7 are turned on as shown in FIG.
Only 14, 14, S16, S17 and S19, that is, the segments 831, 841, 95, 96, 97 and 81 of FIG.
The lighting state is as shown in.

That is, the segment S3 (831) is illuminated in white, and the segment S4 (841) is lit at a predetermined cycle.
) Blinks to indicate that there is no toner in the black developing device.

Next, a case in which the red toner developing device is selected and the toner in the hopper 562 of the red toner developing device 242 is exhausted is detected by the toner depletion detector 572, as shown in FIGS. This will be described with reference to FIGS. 18 to 20.

When the toner out detector 572 detects the toner out, the main control unit 100 determines the data signal C [1000000000000101101000000000] as a data signal indicating this state.
0000] and segment S2 (842) in the data signal C
The signal to turn on [110000000000010110100000
00000000] (hereinafter referred to as data signal E) are alternately output in synchronization with the frequency of the oscillation circuit 121.

As a result, when the data signal C is output, the segments S1, S14, S15, S16, S17, and S19.
Only, that is, the segments 832, 95, 9 of FIG.
6,97,81 are in the lighting state as shown in FIG. 14,
When the data signal E is output, the segments S1,
Only S2, S14, S16, S17 and S19, that is, FIG. 3 (a)
Of the segments 832, 842, 95, 96, 97, 81
Lights up as shown in FIG.

That is, the segment S2 is sent at a predetermined cycle.
Make (842) blink in yellow to display segment S1 (83
By turning on 2) in red, it indicates that there is no toner in the red developing device. Next, the color selection operation will be described with reference to the flowchart shown in FIG.

First, when a power switch (not shown) is turned on, the main controller 100 confirms that the black developing device is selected on the liquid crystal display panel 80 and is in the standby state, as shown in FIG. Display it (ST1).

Then, the main controller 100 uses the driver 103.
By driving the developing device control circuit 111 via
The developing device 241 for black color is moved and brought into contact with the photoconductor 20 (ST2). Next, when the main control unit 100 determines that the color selection switch 77 has been turned on (ST3), the main control unit 100 indicates on the liquid crystal display panel 80 that the red developing device has been selected and is in a standby state. Seise (ST
4).

Then, the main controller 100 uses the driver 103.
The developing device control circuit 111 is stopped through the drive and the developing device control circuit 112 is driven, thereby developing the black developing device 241.
Is moved toward and away from the photoconductor 20, and the red developing device 242 is moved to be brought into contact with the photoconductor 20 (ST5). In addition,
When the color selection switch 77 is turned on while the red color developing device 242 is selected, the main control unit 100 performs an operation in which red and black are reversed.

Next, although the processing of step 5 is completed (ST6), when it is determined that the color selection switch 77 is not turned on in step 3 and the temperature of the fixing device 29 reaches the fixable temperature (ST7), the main The control unit 100 causes the liquid crystal display panel 80 to display that the copying machine is in a copyable state with the selected developing device as shown in FIG. 11 or 14 (ST8). If the fixing device 29 does not reach the fixing possible temperature in step 7, the process returns to step 3.

Then, following step 8, the main controller 100 activates a timer (not shown) (ST9), and then judges that the color selection switch 77 is turned on (ST1).
0), return to step 4. Further, in step 9, the main control unit 100 does not determine whether the color selection switch 77 is turned on (ST1
0), the main controller 100 indicates that the liquid crystal display panel 80 can be copied when it is judged that the copying is possible (ST11) and when the copying key 72 is pressed before the timer times out (ST12, 13). The segment S19 (81) is turned off (ST14), and a copying operation including normal charging, exposure, development, transfer, peeling and fixing is performed (ST15).

If there is no paper in the paper feed cassette 2 or the lid of the hopper is opened in step 11, the main control unit 100 turns off the segment S19 (81) indicating that copying is possible on the liquid crystal display panel 80 (ST16). ), And returns to step 9. After step 16 is performed, when the process proceeds to step 11, before the process proceeds to step 12, the main control unit 100 causes the segment S19 (81) of the liquid crystal display panel 80 to be displayed.
Is turned on (ST17).

When the time-out of the timer is detected in step 12, the process returns to step 1. Due to this time-out, the main control unit 100 can copy even though the copy is possible.
The user determines that the user has left the device without any operation for a second, and returns to the initial state according to this determination, so that the next user does not need to perform an unnecessary operation.

Next, the display when the toner is used up will be described with reference to the flow chart shown in FIG. The interrupt processing for this toner-less display is performed at a predetermined timing. First, the main control unit 100 determines which of the black and red developing plates 241 and 242 is selected (ST21).

When the black developing device 241 is selected by this determination, the main control unit 100 determines whether the toner-free detector 571 detects the toner-free condition (ST.
22). As a result, when the toner-free detector 571 detects the absence of toner, the main control unit 100 selects the black developing device on the liquid crystal display panel 80 as shown in FIG. Is displayed (S
T23).

When it is determined in step 21 that the red color developing device is selected, the main control unit 100 determines whether the toner out detector 572 detects the toner out (ST24). As a result, the toner-free detector 572
If no toner is detected, the main control unit 100 causes the liquid crystal display panel 80 to select the red developing device as shown in FIG. 20, and displays that there is no toner (ST25).

When the toner-free detectors 571 and 572 have not detected the toner-free state in steps 22 and 24, respectively, and when the predetermined display is carried out in steps 23 and 25, the main controller 100 causes the internal memory to operate. It is determined whether the blinking flag (not shown) is "1" or "0" (ST
26) In the case of "1", the segment S2 (842) or S4 841) indicating that the liquid crystal display panel 80 is out of toner is turned off (ST27).

After the light is turned off or when the flag is determined to be "0" in step 26, the main control unit 100 determines whether or not the timer T1 (not shown) has timed out (ST2.
8) In the case of timeout, the content of the flag is changed to "0" when it is "1" and to "1" when it is "0" (ST2
9) The timer T1 is activated (ST30), and the interrupt process ends.

If the timer T1 does not time out in step 28, the interrupt processing is terminated. As a result, the interrupt processing is performed many times (integer times) within the time-out period of the timer T1, and the flag repeats "1" and "0" at each time-out of the timer T1. As a result, the segment S2 (842) Or S4 (841)
Blinks repeatedly. When the power is turned on, the flag is "0" and the timer T1 is activated.

Although red and black toners are used for the developing device in the above embodiment, toners of other colors may be used. Furthermore, although a liquid crystal display element is used, the invention is not limited to this.
A light emitting diode, a lamp, or the like may be used, and the display of black or a color mainly used may not be displayed and may be selected.

[0087]

As described in detail above, according to the present invention,
In an apparatus having two developing devices capable of developing two colors, it is possible to provide an image forming apparatus in which the image forming operation can be prohibited while the developing device selecting operation is being performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a copying machine according to an embodiment of the present invention.

FIG. 2 is a plan view of an operation panel of the copying machine shown in FIG.

FIG. 3 is a view showing an arrangement example and a display example of segments constituting a schematic figure of a copying machine displayed on the liquid crystal display panel of FIG.

FIG. 4 is a block diagram schematically showing the overall configuration of the copying machine shown in FIG.

5 is a configuration diagram of the liquid crystal drive circuit of FIG.

FIG. 6 is a timing chart for explaining the operation of the copying machine shown in FIG.

FIG. 7 is a voltage waveform diagram applied to the liquid crystal display panel of FIG.

FIG. 8 is a diagram showing a display state of the liquid crystal display panel of FIG.

9 is a timing chart for explaining the operation of the copying machine of FIG.

10 is a voltage waveform diagram applied to the liquid crystal display panel of FIG.

11 is a diagram showing a display state of the liquid crystal display panel of FIG.

12 is a timing chart for explaining the operation of the copying machine shown in FIG.

13 is a voltage waveform diagram applied to the liquid crystal display panel of FIG.

14 is a diagram showing a display state of the liquid crystal display panel of FIG.

15 is a timing chart for explaining the operation of the copying machine shown in FIG.

16 is a voltage waveform diagram applied to the liquid crystal display panel of FIG.

17 is a diagram showing a display state of the liquid crystal display panel of FIG.

FIG. 18 is a timing chart for explaining the operation of the copying machine shown in FIG.

19 is a voltage waveform diagram applied to the liquid crystal display panel of FIG.

20 is a diagram showing a display state of the liquid crystal display panel of FIG.

FIG. 21 is a flowchart for explaining a main part of the operation of the copying machine of FIG.

22 is a flowchart for explaining a main part of an operation in the copying machine of FIG.

[Explanation of symbols]

241, 242 ... Developing device, 571, 572 ... Toner-less detector, 71 ... Operation panel, 76 ... Liquid crystal display section, 77 ...
Color selection switch, 80 ... Liquid crystal display panel, 831, 83
2 ... Segment (developer display element), 841, 842 ...
Segment (toner-free state display element), 100 ... Main control unit, 103 ... Driver, 111, 112 ... Developing device control circuit, 120 ... Liquid crystal drive circuit.

Claims (1)

(57) [Scope of utility model registration request] 1.Image bearing containing a first color developer
A first developing device for developing the latent image on the body with a first color; Do not store the developer of the second color different from the first color.
The second current for developing the latent image on the image carrier with the second color.
An imager, Either one of the first and second developing devices
Selection means for selecting the imager, After uniformly charging the surface of the image carrier, expose and scan the document.
By doing so, a latent image corresponding to the image of the above document is formed on the image carrier.
Formed on the latent image and selected by the selecting means for this latent image.
By the first developing device or the second developing device
To supply the developer of the first color or the second color
Further development, the developed image on the image carrier is
A series of images that are transferred onto paper and then fixed at a specified temperature.
Form an image on paper by performing an image forming operation
Image forming means for This image forming means is operable and inoperable
Display means to display that it is Noh, Either the first developing device or the second developing device
When one developing device is selected, select the above
If the other developer is selected by
While the operation to move the selected developing device of is being performed,
The above-described series of image forming operations are performed on the image forming means.
It is prohibited to go to the above display means
Display that the image forming means is inoperable and
When the operation to move the selected developer is completed,
If the fixing temperature of the image forming means is not higher than a predetermined temperature,
The image forming operation cannot be performed on the display means.
Is displayed and the movement of the selected developing device is moved.
When the work is completed, the fixing temperature of the image forming means is set to a predetermined value.
If the temperature is equal to or higher than the temperature, the image forming operation is performed on the display means.
Control means for making a display that the work is operable,  An image forming apparatus comprising: