JPH01211777A - Image forming device - Google Patents

Abstract

PURPOSE:To confirm which developing device has no developer by selecting a developing means, and detecting there is no developer in the selected developing means and displaying that there is no developer. CONSTITUTION:When a black tone developing device is selected, and when a no toner detector 571 detects that there is no toner in a hopper 561 of the black tone developing device 241 for the black tone, a main control part outputs alternatively a data signal B, and a data signal D, which is the data signal B plus a signal to light a segment 841, as the data signals to show this condition, synchronized to the frequency of the oscillation circuit. That is, a segment 831 is lit in white, and by blinking a segment 841 at a specified frequency, no toner in the black tone developing device is displayed. Thus the fact that there is no developer in developing device 241, 242 can be confirmed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention has a plurality of developing devices capable of developing different colors, for example, and the developing devices of various colors are The present invention relates to an image forming apparatus that is capable of forming images of various colors on one original document.

(Prior Art) Conventionally, in some image forming apparatuses such as electronic copying machines, monochromatic images with different colors can be obtained by replacing a developing device or a cartridge including the developing device. However, in such a device, it is very inconvenient to replace the cartridge. Recently, a device has been equipped with multiple developing devices capable of developing different colors, and by switching between these developing devices, various colors can be selected, and images of various colors can be formed on one document. An image forming apparatus that can perform the following has been considered. but,
This device has a drawback in that it is not possible to confirm which developing device has run out of developer.

(Problem to be solved by the invention) As mentioned above, this invention eliminates the drawback that it is not possible to check whether the developer is running out in the developing device.
``Objective 1'' is to provide an image forming apparatus that can check whether there is developer or a developing device that has run out.

[Structure of the Invention] (Means for Solving the Problems) The image forming apparatus of the present invention includes a first developer which stores a developer of a first color and develops an image on an image carrier into the first color. means, a second developing means that accommodates a developer of a second color and develops the image on the image carrier in the second color, and selecting a developing means from the first developing means and the second developing means. and a display means for detecting that there is no developer of the developing means selected by the color selecting means and displaying that there is no developer of the color selected by the color selecting means. It is something that

(Function) This invention selects the first developing means for developing the first color or the second developing means for developing the second color, and detects that there is no developer in the selected developing device. It detects this and displays a message indicating that there is no developer.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 illustrates an image forming apparatus of the present invention, such as an electronic copying machine. That is, in the figure, 1 is a copying machine body with a built-in copying mechanism, 2 is a paper feed cassette attached to the right side of the copying machine body 1, and 3 is a paper output tray attached to the left side of the copier body 1. .

Further, on two sides of the copying machine main body 1, there is provided a document table 4 that can freely move back and forth in the left-right direction (in the direction of arrow a), and on the front edge of the top surface of the copying machine main body 1 there is an operation panel (not shown). Or is provided. The document table 4 has a document placement plate (glass plate) 12 on which a document is placed, and a document cover 13 that covers the top surface of the document placement plate (glass plate) 12 . Further, the cassette cover 14 of the paper feed cassette 2 serves as a manual paper feed tray 15 for manually feeding paper P1 as appropriate.

Reference numeral 20 in the drawing denotes a drum-shaped photoreceptor disposed approximately at the center of the copying machine main body 1, and the photoreceptor 20 is driven in the direction of the arrow in synchronization with the document table 4 by a drive mechanism (not shown). First, an original image uniformly charged by a charger 21 and uniformly irradiated by an exposure lamp 22 is imaged on a photoreceptor 20 by a focusing light transmitter (trade name SELFOC lens array) 23. It is designed to form an electric latent image. The formed electrostatic latent image is sent to the transfer charger 25 side as a toner image by the developing device 24□ or 242 selected by a selection mechanism (not shown).

The developing device 24□ develops black color, and the developing device 242 develops red color.

A sheet P or P' that is automatically or manually fed is fed by a sheet feeding device 26, and a toner image previously formed on a photoreceptor 20 is transferred onto the sheet P or P' by a transfer charger 25. Furthermore, the toner image is peeled off from the photoreceptor 20 by a peeling charge 27 caused by AC corona discharge, passes through a conveyance path 28, and is fused and fixed onto the paper P (P') by a fixing device 29, and is then moved to a tray that can be attached or detached by an ejection roller 30. It is discharged at 3.

On the other hand, after the toner image is transferred onto the paper P (P'), the residual toner remaining on the photoconductor 20 is cleaned by a cleaning device 31, and the potential on the photoconductor 20 is lowered to a certain level or less by a static elimination lamp 32. The copy operation is enabled.

A fan 33 serves as a cooling device, and exhausts heat generated from the heat-generating exposure lamp 22 and the fixing device 29 inside the machine.

Inside the copying machine main body 1, an upper frame and a lower frame (not shown) are pivotally supported at one end via a support shaft 37, and the other ends of both frames are configured to be opened at a desired angle, for example, 30 degrees. ing. The upper frame includes a charger 21, a focusing light transmitter 23, an exposure lamp 22, a developing device 24, a cleaning device 31, around the photoreceptor 20,
Each device such as a static elimination lamp 32 is attached by appropriate means, and a fan 33 as a cooling device, a paper feed roller 38 of a paper feed device 26, and a document table 4 are also attached to the frame to constitute the upper unit IA. ing. In addition, the frame includes various mechanisms such as a paper feed cassette 2, a transfer charger 25, a peeling charger 26, a conveyance path 28, a forming guide plate 39, a fixing device 29, a pair of ejection rollers 30, a tray 3, and a main motor (DC planless motor) 35, power supply section 3
The lower unit IB is attached by 4 etc. or other appropriate means.
It consists of After the front cover 1a of the copying machine main body 1 is rotated and removed, it is configured so that it can be opened and closed almost along the transport path 28 of the paper P (P') via a housing opening/closing device (not shown). . Therefore paper p (p'
) Even if paper becomes jammed on the conveyance path 28, it can be easily taken out.

In addition, 50.50 in FIG. 1 corrects the inclination of the leading edge of the paper P that is mechanically fed from the paper feed cassette 2 or the paper P' that is manually fed, and also forms a toner image on the photoreceptor 20. This is a pair of registration rollers that feed the paper P or P' toward the transfer charger 25 in synchronization with the operation, and 51 is a manual feed detection switch that is disposed just before the pair of registration rollers 50 and 50.

52 is a paper discharge switch, 53 is a total counter, 54 is a paper empty switch that detects when the paper P in the paper feed cassette 2 is empty, and 55.55 is the thickness of the developer layer in the developing device 24, 242. 56,562 is a toner hopper, 57,572 is a toner-free detector as a detection means, 58,582 is a toner concentration detector, 59,592 is a hopper lid, and 57,572 is a detection means. Otherwise, the document table 4 will not move.

Further, 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, 65 is a cleaning blade 66 of the cleaning device 31.
This is a weight for bringing the blade into contact with the photoreceptor 20 at a constant pressure, and a solenoid (not shown) moves the blade toward and away from the photoreceptor 20.

The out-of-toner detector 571 is composed of the toner hopper 56, a magnet 42 provided at the tip of a moving body 41□ that rotates depending on the amount of toner in the toner hopper 56, and a reed switch 431 provided outside the toner hopper 561. has been done. Further, the toner-free detector 572 also includes a magnet 422 provided at the tip of the moving body 412 and a reed switch 43 provided outside the toner hopper 562 in the same manner as described above.
2.

Note that the reflector 63, the auxiliary reflector 64, and the convergent light transmission body 23 are assembled as one unit.

Further, the paper feed device 26 provided at the lower right side of the copying machine main body 1 includes a paper feed cassette 2 and a cassette that covers the upper surface side of the paper feed cassette 2 with a separation claw or an opening for removing paper provided therein. A manual paper feed tray 15 formed on the cover, and a paper feed roller 3 that takes out and supplies paper P from the paper feed cassette 2.
8.

Figure 2 shows the operation panel 7, including a copy key 72 for executing copy operations, a numeric keypad 73 for setting the number of copies, and a function for clearing the set number of copies and stopping the copy operation. a clear/stop key (C/S key) 74 that has a function to change the number of copies, a number display section 75 that displays the remaining number of copies subtracted from the set number during copying, and a liquid crystal display that displays the operating status and copying condition selection status. Display section 76, switching of the plurality of developing devices 24, 24°, that is, a first mode in which an image is formed in black (first color), or a second mode in which an image is formed in red (second color). A color selection switch 77 for switching, a volume 78 for adjusting the exposure amount and setting the image density, and the like are provided.

FIG. 3(a) is a layout diagram of segments constituting a schematic diagram of the copying machine displayed on a liquid crystal display element in the liquid crystal display section 76. That is, 80 is a liquid crystal display panel, and 81 and 82 are segments for displaying pictograms that indicate whether copying is possible.Segment 81 alone can be copied, and both segments 81 and 82 cannot be copied (during warm-up).
shows. 83 is a graphic representation of the hopper of the developing device 24, and is a pictogram display segment indicating that this developing device 24 has been selected, and the color of the image obtained by this developing device 242, for example, black, is displayed in white. It looks like this. In reality, the back of the liquid crystal display panel is black, and the display 832 is displayed in white as shown in FIG. 3(b). 83 is a graphic representation of the hopper of the developing device 242, and is a pictograph display segment indicating that this developing device 242 has been selected.
The color to be selected is displayed by displaying the color of the image obtained by step 2, for example, red.

Further, 84 and 842 are the developing units 24 and 242, respectively.
85 is a pictorial display segment indicating that the toner hopper is empty of toner, 85 is a pictorial display segment indicating that the collected toner storage section is full of collected toner, and 86 is a transport path in or near the fixing device 29. A pictorial display segment 87 indicates that a paper jam has occurred in the photosensitive drum 20 or the cleaning device 3.
A pictorial display segment 88 indicates an instruction to call a key operator, a pictorial display segment 89 indicates an instruction to call a service person. , 90 to 93 are segments for displaying pictograms indicating the transport status of the paper P, 94 is a segment for displaying pictograms indicating that the paper P in the paper feed cassette 2 has run out, and 95 is a segment for displaying a pictogram indicating that the paper P in the paper feed cassette 2 has been inserted. 96 is a segment for displaying the lower cover of the copier main body 1, 97 is a segment for displaying the upper cover in the closed state, and 98 is the segment 99 for displaying the upper cover in the open state. This is a display segment of the body drum 20. Although not shown, a common electrode is provided on the surface facing each of the segments.

FIG. 4 shows the overall configuration of the copying machine.

That is, 100 is a main control section composed of a microcomputer, etc., and this includes an input section (various keys 72 to 78) of the operation panel 71 and (for example, toner empty detectors 57, 572, etc.). ) various detector groups 161 are connected via the input interface 102 . The main control unit 100 controls the operation of the entire copying machine, and the driver 03
A blade solenoid 1 that drives the static elimination lamp 32, the main motor 35, and the cleaning blade 66 via the
04, Table forward solenoid 105 that moves the document table 4 forward, Table back solenoid 106 that makes the document table 4 move backward, Paper feed roller solenoid 107, Registration roller solenoid 108, Toner replenishment solenoid 1
09, 110, and developer control circuits 111, 112.

The paper feed roller solenoid 107 and the registration roller solenoid 108 actuate or stop spring clutches between the drive source and each roller in order to rotate or stop the paper feed roller 38 and the registration roller, respectively. The toner supply solenoids 109 and 110 are
The toner concentration detectors 58 and 582 respectively detect that the toner concentration is below the specified value, and the developer 24.
Toner hub 56 at 242.

Toner is replenished from 562. - The developer control circuit 11L 112 is connected to the developer 24,
24° is selected, and the corresponding developing device is brought into contact with and separated from the photoreceptor 20 by controlling the drive.

The developer 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 13.
, a heater control circuit 114 , a high voltage transformer 115 , and a sheet number display circuit 117 are connected via a driver 16 . The lamp regulator 13 is connected to the exposure lamp 22.
It controls the energization to. The high voltage transformer 115 operates the charger 21 and the transfer charger 2 according to the control signal.
5. A voltage is applied to the peel charger 27 and the like. The heater control circuit 114 controls power supply to the fixing heater 19 of the fixing device 29 to maintain the temperature at a fixable temperature. The sheet number display circuit 117 performs a display operation by selectively lighting up the LED segments of the sheet number display section 75.

The main control unit 100 also controls each state of the copying machine [1, 2].
, 4, 8] into a binary code signal and output from output terminal OD, and output terminal OL.

○C outputs a latch signal and a clock signal, respectively. The liquid crystal drive circuit 120 receives a data signal from the main control section 100 or a clock signal from the input terminal IC at its input terminal ID in synchronization with the clock signal from the input terminal IC. The oscillation circuit 121 oscillates at the optimum frequency for driving the liquid crystal.
Drive pulse A from the output of 21 and the inverter circuit 122
An inverted driving pulse B is generated and input to the liquid crystal driving circuit 120. Therefore, each output of the output terminal 0''-Os2 of the liquid crystal drive circuit 120 is connected to the segment S-O of the liquid crystal display element provided in the liquid crystal display panel 80.
The output of the inverter circuit 122, that is, the driving pulse B, is supplied to the common electrode 123, which is provided opposite to each segment S-832.

Note that the segments 81 to s3° indicate the segments 81 to 99 in FIG. 3(a), and correspond to each other as shown in the table below. Also, segments 96 and 99 are connected to the same segment 816.

FIG. 5 shows the liquid crystal drive circuit 120 in detail. That is, the shift registers 31 to 13132 are continuously connected, and the first stage shift register 31
1 receives a data signal from the input terminal ID, and each of the shift registers 131 to 13132 receives a gate lock signal from the input terminal IC. Thereby, the data signal from the input terminal D is sequentially transferred to each of the 32 shift registers 31 to 1313 degrees in synchronization with the clock signal from the input terminal IC. Each of the shift registers 311 to 13132 is directly connected to store registers 132 to 13232, which hold their respective contents in response to a latch signal from an input terminal IL.

Each of the store registers 39 to 13232 selectively outputs the drive pulse A or B to the output terminals O to 032 by controlling the opening and closing of the switches 1331 to 13332, respectively, according to the stored contents. That is,
For example, opening/closing control is performed so that when the content of the store register is "1", the drive pulse A is outputted to the corresponding output terminal, and when the content is "0", the drive pulse B is outputted to the corresponding output terminal.

Next, in the above configuration, FIGS. 6 to 20
The operation will be explained with reference to the figures. Note that FIGS. 6, 9, 12, 15, and 18 show timing charts, and FIGS. 7, 10, 13, 16, and 19 show the liquid crystal display panel 80. Figures 8 and 11 show the voltage waveforms applied to.

FIG. 14, FIG. 17, and FIG. 20 show display examples.

First, the case where the power switch (not shown) is turned on and the copying is disabled (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 10, the main control unit 10
0 starts operation according to a preprogrammed program, and the fixing heater 119 of the fixing device 29
energize. Also, at this time, the fixing device 29 has not yet reached the fixing temperature, so it is in a standby state, and
Furthermore, since the black developer is automatically selected when the power is turned on, a data signal indicating the standby state and the selection of the black developer, for example, [001000000000010110110000]
Data signal 000000001 (hereinafter referred to as data signal A)
) is output to the output terminal OD. In this case, the data signal A is outputted in synchronization with the clock signal outputted to the output terminal OC, and a latch signal is outputted from the output terminal OL when the last 32nd bit data transfer is completed. As a result, the store register 32 in the liquid crystal drive circuit 120
The data signal A is held in store registers 32. to 13233, and the contents thereof are set to "1". 1
32. 132□6゜132 132 1322o
A drive pulse A is output from the output terminals 17', 19', and 0.014"16"17"19"20 corresponding to the output terminals 17', 19', and 20, and this becomes a segment drive signal to be applied to each segment S, S14, . S16.
S17. S19. Applied to S2o. Also, if the content is “
Store register 32 .132 .
1324～132.3°132 132 132
~13232 and corresponding 15'18' 2
1 output terminal 0. 0. 0 ~ 00 1 2 4 13'15' O, ○ A driving pulse B is output from ~O, and this becomes a segment driving signal of the opposite polarity to the liquid crystal display panel 80.
Each segment S, S, S413, 15, 18
・S21~S32+C impression 1 is applied・~S
S S At this time, the common electrode 123 of the liquid crystal display panel 80 and each segment s, s, s s s3 14
There is a 7th
A voltage with an AC waveform as shown in Figure (f) is applied. As a result,
Segments S, S3 14°S S S S-) 1G'17'19' 20 Segments 8B, 95, 96, 97, 81° 82.
99 is in a lit state.

On the other hand, segments S , S , Sl other than the above
2 4 ~ 5sss-s, Fig. 7 13'15'18" 2132 (c), (e)
Since a voltage in phase with the common electrode 123 is applied as shown in FIG. 7(g), there is no potential difference between them as shown in FIG. '
21S, that is, each segment 832°84.21S in FIG. 3(a). 84. 85 to 94.98 is a non-lighting state. Therefore, the display in this case will be as shown in Figure 8,
It is displayed that it is in a standby state and that the developing device for black color is selected. The black developer is selected as the normal priority mode. In this case, the segment S3 (83,) is displayed in reverse against the black background, as shown in FIG. 3(b).

Next, a case will be described with reference to FIGS. 9 to 11 about a case where copying becomes possible after going through a standby state, and in this state, a black developing device is selected. When the temperature of the fixing device 29 has reached a temperature at which fixing can be performed, the color selection switch 77 is not operated after the power is turned on, or the black developer selection operation is completed by operating the color selection switch 77 ( Copying operation is not possible from the time the color selection switch 77 is operated until the selection operation of the developing unit is completed, and the copying operation is enabled (the display explained in FIGS. 6 to 8 above is displayed). When the main control unit 100 sends a data signal indicating this state, for example [00100000000
001011010000000000000] (hereinafter referred to as data signal B) is output by the same operation as described above.

As a result, the data signal B is held in the store registers 1321 to 13232, and the store registers 1323, 132, . 132
132 132.9 and corresponding 14
1B'17' output terminal o, o
o o o to 3 14= 113
'17' At 19, driving pulse A is output, and each corresponding segment s, s, s s s
Applied to 3 14 1B"17' 19
It will be done. In addition, the store register 132. whose content is "0". 132. 1324~132.3°132
132 132 ~ 13232 and corresponding 15'
18' 20 Output terminal ○, o, o-o.

Drive pulse B is output from 1 2 4 13'15' 00-0, and 18°
2032 This or each corresponding segment S , S , S ~
ss, 5s-s. At this time 13' 15 18'' 2032, the driving pulse B is applied to the common electrode 123 as described above, so the common electrode 123 and the segment s,
3 14' between s s s s
16', 17', and 19 are applied with voltages having an alternating current waveform as shown in FIG. 10(f). As a result, segment S,
SS 3 14'16' 8 S That is, each segment 17' in Fig. 3(a)
19 83. 95, 96, 97.81 are in a lighting state.

On the other hand, the segments s, ss 1 2'' 4 to 5sss-s other than the above include Fig. 10 13' 15° 18' 20 32 (C),
As shown in (e), since the voltage in phase with the common electrode 123 is applied, the segments S, S2゜■5-ssss-s, that is, the fourth 13''15'18' 2
0 323 Each segment in Figure (a) 82.83 .
842°84.85 to 94.98 is a non-lighting state.

■ Therefore, the displayed figure in this case is as shown in Fig. 11, and the segment S (831
) is displayed in white against the black color of the pack to indicate that the black developing device has been selected and is ready for copying operation.

Next, a case where the red developing device is selected and the copying operation is possible will be described with reference to FIGS. 12 to 14. By operating the color selection switch 77, the selection operation of the red developing device is completed. In this embodiment, the black developing device is placed above the red developing device, and if no operation is performed for a certain period of time (for example, 1 minute) after the power is turned on or after the red developing device is selected. Since the black developing device is automatically selected, the color selection switch 77 must be operated in order to select the red developing device. By the way, when the color selection switch 77 is operated as described above, the copying operation is not possible until the selection operation of the developer is completed, so the display is performed until the selection operation is completed. However, as in the case of selecting a black developer, the display includes segment 528 (82
) is simply turned on, so the explanation will be omitted.

When the copying operation becomes possible, the main control unit 100 sends a data signal indicating this state, for example, [1000000].
0000001011010000000000000
A data signal (hereinafter referred to as data signal C) is output.

As a result, the same operation as described above is performed, and the common electrode 123 and the segments s, s, s sl 14 16'
17' An alternating current waveform voltage is applied between S19 and the segments 8B and 9 in FIG. 3(a).
5, 96, 97.81 are lit, and the other segments 82.83 in FIG. 3(a)
．． 84. 842°85 to 94.98 is a non-lighting state. Therefore, the display figure in this case becomes as shown in FIG. 14, and the segment 5 (8
32) By displaying ■ in red, it is indicated that the red developing device has been selected and the copying operation is possible.

Next, regarding a case where a black developing device is selected and the toner out detector 57 detects that the toner in the Honpara 61 of the black developing device 24 has run out.
This will be explained with reference to FIGS. 9 to 11 and FIGS. 15 to 17. When the out-of-toner detector 57 detects out-of-toner (as long as the toner is gone from the hopper 561, copying operation is still possible), the main control unit 100 sends a data signal B[0010 as a data signal indicating this state.
0000000001011010000000000
000] and the segment S4 (84
00110000000001011010000
Data signals 0000000001 (hereinafter referred to as data signals) are alternately output in synchronization with the frequency of the oscillation circuit 121.

As a result, when data signal B is output, only segment s, s s s s , 3
14'1B'17' 19 That is, Fig. 3 (a
) segment 83,95°96.97.81 or 11th
When the lighting state shown in the figure is reached and the data signal is output, the segments s, s, s, s s
s da3 4 14 1B'17' 1
9, that is, segment 83□ in FIG. 3(a).

84. 95, 96, 97.81 are turned on as shown in FIG. That is, segment S3 (8
3□) lights up in white, and the segment S
4 (84,) blinks to indicate that there is no toner in the black developing device.

Next, the first case where the toner empty detector 572 detects that the red developing device 24 is running out of toner in the hopper 562 of the red developing device 24 is selected.
This will be explained with reference to FIGS. 2 to 14 and FIGS. 18 to 20. When the out-of-toner detector 572 detects out-of-toner, the main control unit 100 outputs a data signal C[1000000000000101 as a data signal indicating this state.
1010000000000000] and a signal that lights up segment S2 (842) is added to the data signal C [11000000000001011010000
A data signal 0000000001 (hereinafter referred to as data signal E) is alternately output in synchronization with the frequency of the oscillation circuit 121.

As a result, when data signal C is output, segment s, s s s s sl
14'15'1G'17' Only 19,
In other words, the segment 832°95.96 in Fig. 3(a),
97.81 is in the lighting state as shown in FIG. 14, and when the data signal E is output, the segments s, s,
s s sl 2 14'16'
17'819, that is, segment 83 in FIG. 3(a). 84. 95, 96, 97, and 81 are turned on as shown in FIG. That is, by flashing the segment S2 (842) in yellow and lighting the segment S (832) in red at a predetermined period, it is indicated that there is no toner in the red developing device.

Next, the color selection operation will be explained using the flowchart shown in FIG. First, when a power switch (not shown) is turned on, the main control section 100 displays on the liquid crystal display panel 80 that the black developing device has been selected and is in a standby state, as shown in FIG. 8 described above. (STI). The main controller 100 then drives the developer control circuit 111 via the driver 03 to control the black developer 2.
4□ is moved so that it comes into contact with the photoreceptor 20 (Sr2).

Next, when the main control unit 100 determines that the color selection switch 77 has been turned on (Sr1), the main control unit 100 displays on the liquid crystal display panel 80 that the red developer has been selected and is in a standby state. Seduce (Sr4).

Then, the main control unit 100 stops the developer control circuit 111 via the driver 103 and drives the developer control circuit 112 to move the black developer 24□ onto the photoreceptor 20.
The developing device 242 for red color is moved to come into contact with the photoreceptor 20 (Sr1). Note that when the color selection switch 77 is turned on while the developing device 242 for red is selected, the main control section 100 performs an operation in which red and black are reversed.

Next, the process in step 5 ends (Sr6), but if it is determined in step 3 that the color selection switch 77 is not turned on and the temperature of the fixing device 29 has reached the fixable temperature (Sr1), the main control unit 100 is the liquid crystal display panel 80
As shown in FIG. 11 or FIG. 14, a message indicating that the selected developing device is ready for copying is displayed (Sr1). Also, in step 7, the fixing device 29
If the temperature has not reached a fixable temperature, the process returns to step 3.

-30= Continuing to step 8, the main control unit 100 activates a timer (not shown) (5T9), and then returns to step 4 if it is determined that the color selection switch 77 has been turned on (STIO). In addition, when the main control unit 100 does not determine that the color selection switch 77 is turned on in step 9 (STIO) and determines that the state is ready for copying (5T11), it determines that the copy key 72 is turned on before the timer times out. (S,
T12. 13) The main control unit 100 turns off the segment 519 (81) indicating that copying is possible on the liquid crystal display panel 80 (ST14), and performs normal charging.

A copying operation consisting of exposure, development, transfer, peeling, and fixing is performed (ST15).

Further, if there is no paper P in the paper feed cassette 2 or the hopper lid is opened in step 11, the main control unit 100
is a segment 51 indicating that the liquid crystal display panel 80 can be copied.
9 (81) is turned off (ST16), and the process returns to step 9. After step 16 is performed, when the process proceeds to step 11, the main control section 100 lights up the segment 519 (81) of the liquid crystal display panel 80 before proceeding to step 12 (ST17). Further, when the timeout of the timer is counted in step 12, the process returns to step 1.

This timeout causes the main ζI;! Even though copying is possible, the I control section 100 determines that the user has left the device without any operation for one second, and depending on this determination, it returns to the initial state so that the next user or No need to perform any necessary operations.

Next, the display when the toner runs out will be explained using the flowchart shown in FIG. 22.

This toner-out display interrupt processing is performed at predetermined timings. The main control unit 100 has a developing device 24□ for black color and red color.

24° is selected (ST2
1). If the black developer 24□ is selected based on this determination, the main control unit 100 detects the toner-free detector 57□.
Determine whether the toner is detected to be out of toner (ST22)
. As a result, when the toner out detector 57 detects that there is no toner, the main control unit 100 controls the liquid crystal display panel 8
As shown in FIG. 17 described above in 0, the black developing device is selected and a message indicating that there is no toner is displayed (S
T23).

Further, if it is determined in step 21 that the red developing device is selected, the main control section 100 detects the toner out detector 57.
2 or no toner is detected (ST24)
). As a result, when the out-of-toner detector 57□ detects out of toner, the main control unit 100 selects the red developing device as shown in FIG. Display that there is no such thing (S
T25).

Then, when the out-of-toner detectors 57 and 57□ do not detect out-of-toner at step 22.24, and when the respective predetermined displays are performed at step 23.25, the main control unit 100 stores information in the internal memory (not shown). It is difficult to determine whether the flashing flag of 5T26) is “1” or “0”.
In this case, the segment S (842) or S4 (84) indicates that the toner on the liquid crystal display panel 80 has run out.
1) is turned off (ST27). After this light goes out, or when it is determined that the flag is "0" in step 26, the main control unit 100 sets a timer (not shown) to determine whether or not it is timed out (5T28), and in the case of a timeout, the content of the flag is set to "1". The time is “0”.

If it is "0", change it to "1" (5T29), activate timer T1 (ST30), and end the interrupt processing. Furthermore, if the timer T does not time out in step 28, the interrupt processing is terminated.

As a result, the above-mentioned interrupt processing is performed many times (an integer number of times) within the timeout period of the timer T1, and the flag is set to "1" each time the timer T1 times out.

By repeating “0”, segment 52 (842)
Alternatively, S4 (841) repeatedly blinks. Note that when the power is turned on, the flag is set to "0" and the timer T1 is activated.

In the above embodiment, there were two developing devices, but a plurality of developing devices other than two may be used. Also, if there is no toner in multiple developing devices, the segment indicating the developing device corresponding to the selected developing device lights up, and the segment indicating the developing device corresponding to the unselected developing device blinks, indicating that there is no toner. A segment for indicating the out-of-toner state corresponding to the developing device may be made to light up or blink.

Further, red and black toners may be used in the developing device, or toners of other colors may be used. Further, a liquid crystal display element may be used, but the display is not limited to this, and a light emitting diode, a lamp, etc. may also be used, and black or a color that is mainly used may be selected by not displaying it.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an image forming apparatus that can confirm whether a developing device is out of developer.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a cross-sectional view showing the schematic structure of a copying machine, Fig. 2 is a plan view of the operation panel, and Fig. 3(a) shows the display on the liquid crystal display panel. Figure 4 shows an example of the arrangement of segments constituting the schematic figure of a copying machine; FIG. Block Diagram,
Figure 5 is a configuration diagram of the liquid crystal drive circuit, Figures 6, 9, and 1.
2, FIG. 15, and FIG. 18 are timing charts for explaining the operation, and FIG. 7 and FIG. 10. FIGS. 13, 16, and 19 are voltage waveform diagrams applied to the liquid crystal display panel, and FIGS. 8 and 11. FIGS. 14, 17, and 20 are diagrams showing each display state, and FIGS. 21 and 22 are flowcharts for explaining the main parts of the operation. 24.24...Developer, 57,57°・Toner-free detector, 71 Operation panel, 76・Liquid crystal display, 77-
・Color selection switch, 80...Liquid crystal display panel, 83, 8
32...Segment (Developer surface hydrogen element), 84.842
Segment (toner ■ - absent status display element), 100... Main control unit, 103
...Driver, 111, 112...Developer control circuit,
120...Liquid crystal drive circuit. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Scope of Claims] A first developing means that contains a developer of a first color and develops the image on the image carrier into the first color; a second developing means for developing the body image into a second color; a color selection means for selecting a developing means from the first developing means and the second developing means; and a color selecting means for selecting a developing means from the first developing means and the second developing means; An image forming apparatus comprising: a display means that detects that there is no developer in the developing means and displays that there is no developer of the color selected by the color selection means.