JPS6086570A - Image forming device - Google Patents

Abstract

PURPOSE:To display exactly whether a developer of a developing device of a selected operating state exists or not, by a comparatively simple display, by detecting the presence of a contained developer of plural developing devices, and displaying a state that no developer exists. CONSTITUTION:When a color of a formed picture is selected by a color selecting switch of an operating panel, a black toner equal developing device or a red toner equal developing device becomes selectively an operating state, and a display is executed by a corresponding developing device display element 831 or 832 of a liquid crystal display panel 80 of the operating panel. Subsequently, whether a developer of a selected developing device exists or not is detected, and in case when no developer exists, a display is executed by toner non-existence state display elements 841, 842 corresponding to the elements 831, 832, respectively. In this way, whether the developer of the developing device of a selected operating state exists or not can be displayed and informed exactly by a comparatively simple display.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention has a plurality of developing devices capable of developing different colors, for example, and develops with developers of various colors contained in these developing devices. The present invention relates to an image forming apparatus that is capable of forming images of various colors on a document image.

[Technical background of the invention and its problems]

In an image forming apparatus having a plurality of developing devices, it has conventionally been difficult to clearly indicate that the developer in the developing device has run out. Furthermore, in order to know which developing device out of multiple developing devices has run out of developer, it is necessary to have the same number of display elements as there are developing devices, but it is only necessary to display the display element corresponding to the developing device that has run out of developer. However, there is a drawback that the correspondence relationship with the selected developing device that is in operation is unclear.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to clearly display the presence or absence of developer in the developing device, although it is a relatively simple display, and to enable the developer to be selected and activated. Without making a mistake with a certain developing device,
An object of the present invention is to provide an image forming apparatus that can detect when a developing device is out of developer.

[Summary of the invention]

This invention is a book in which the state of no developer is individually displayed for each of a plurality of developing units.

[Embodiments of the invention]

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

FIG. 1 illustrates an image forming apparatus, such as an electronic copying machine, according to the present invention. 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, a document table 4 is provided on the top surface of the copying machine main body 1 and is movable back and forth in the left-right direction (direction of arrow a). ) 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 . In addition, the cassette cover 14 of the top & The photoreceptor 20 is a drum-shaped photoreceptor disposed in the photoreceptor 20, 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, a document image uniformly charged by a charger 21 and uniformly irradiated by an exposure run f22 is imaged on a photoreceptor 20 by a focusing light transmitter (trade name SELFOC lens array) 23. It is a trap that causes the formation of an electric latent image. The formed electrostatic latent image is shown in FIG.
．． The toner image is then sent to the transfer charger 25 side. The developing device 24t performs black development;
2 is designed to perform red development.

Automatic is also ll, < means that manually fed paper P or P' is fed by the paper feed device flt26, and is placed in advance on the photoreceptor 20.
The toner @ formed on the paper is transferred onto the paper P or P' by the transfer chart 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 17, and is fused and fixed onto the paper P (P') by a fixing device fit 29, and is then moved to a tray that can be attached and detached by an ejection roller 30. It is discharged at 3.

m1, after the toner image is transferred onto the paper P (P'), the residual toner remaining on the photoconductor 20 is cleaned by the cleaning device M31, and the potential on the photoconductor 20 is lowered to below a certain level by the static eliminating land 32. It is ready for the next copy operation.

Further, a fan 33 serves as a cooling device, and exhausts heat generated from the heat generating section exposure land 22 and the fixing device fθ 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 is provided with a charger 21, a focusing light transmitter 23, an exposure lamp 22, a developing device 24, a cleaning device w31, around the photoreceptor 20,
Each device u 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, and the upper unit (JA) is attached to the frame. It consists of The father frame has various machines 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, etc.
l'? 'yz in motor (DC brushless motor) 35
, a power supply section 34, etc. are attached by appropriate means to constitute a lower unit (JB).

Then, rotate the front cover 1a of the copying machine main body 1 and remove it 1. After that, it can be opened and closed approximately along the transport path 28 of the paper P (P') via a housing opening/closing device (not shown). Therefore, the paper P (P') is stored on the conveyance path 28 in a paper jam (which can be easily ejected next time).

In Fig. 1, so and so are paper P automatically fed from the paper feed cassette 2 yen or manually fed 1 yen. Fed paper P'
In addition to correcting the inclination of the leading end surface of the paper P or
5) is a manual feed detection switch placed just before the pair of reno rollers 50. 52 is a paper ejection switch, 53 is a total counter, 54 551 and 553 are the paper two switch that detects the sound when the paper P in the paper feed cassette 2 is out, and the developing device 24@+
Doctor regulating the thickness of the developer layer of 242, 561
.

562 is a toner hopper, 5F, 5F is a detection means.
581 and 582 are toner concentration detectors; 59. ．． Reference numeral 592 is the lid of the hora-gu, which prevents the Harayudai 4 from moving unless this is closed.

Ota, 601d high voltage transformer, 61Jd static elimination brush, 6
2 is a handle formed for opening and closing the upper unit; 6;
3 is a reflector 64 surrounding the back of the exposure run fz2;
is an auxiliary reflector.

ifr:,,65 is the cleaner of cleaning device B31 = 7”
A weight is used to bring the blade 66 into contact with the photoreceptor 2o at a constant pressure, and a solenoid (not shown) causes the blade to move toward and away from the photoreceptor 2o.

The toner empty detector 57I is composed of a magnet 42I provided at the tip of a moving body 411 that rotates according to the amount of toner in the toner horn 561, and a reed switch 431 provided outside the toner hole 456M. has been done. Further, the toner-free detector 572 also includes a magnet 42□ and a toner hopper 56 provided at the tip of the moving body 12 in the same manner as described above. The reed switch 43 is provided on the outside of the reed switch 43.

Note that the reflector 63, the auxiliary reflector 64, and the convergent light transmitter 23 are assembled into one unit at 1°.

The paper feed unit w26 provided at the lower right side of the copying machine main body l includes a paper feed cassette 2 and a cassette that covers the top side of the paper feed cassette 2 leaving an opening for taking out paper provided with a separation claw. 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 71'ft, which has a copy key 72 for executing the copying operation, a numeric keypad 23 for setting the number of copies, etc., a function to clear the set number of copies, and a function to stop the copying operation. Clear/stop key (
C/S key) 24, a number display section 75 that displays the remaining number of copies subtracted from the set number of copies during the copying operation, a liquid crystal display section 76 that displays the operating status and the selection form of the four copies, and the plurality of copies. A color selection switch 27 for switching the developing device 241, t241&, and a polyurethane switch 78 for adjusting the exposure bud and setting the image density are provided.

FIG. 3(a) is a layout diagram of segments constituting a schematic diagram of the paper machine displayed on a liquid crystal display element in the liquid crystal display section f/6. Finally, 80 is a liquid crystal display panel, and 81.112 is a pictogram display segment that indicates whether copying is possible.Segment 81 alone indicates that copying is possible, and both segments 8 and 82 indicate that copying is not possible (during warm-up). show. 83@l'i This is a graphic representation of the hopper of the developing device 241. This is a pictograph display segment indicating the selected color and gold of this developing device 241, and the color of the image obtained by this developing device 242, for example, black, gold, and white. It is designed to be displayed.

Actually, the LCD display ZF panel pack is black, and the display is 83! This is displayed in white as shown in FIG. 3(b). 832 is a graphic representation of the developing device 24. This is a pictogram display segment indicating that the developer 242 has been selected.
The selected color is displayed by displaying the color of the image obtained by, for example, red. Also, 8
41 +842 are the developing devices 241.24!
85 is a segment for displaying a pictogram indicating that the toner hopper is empty of toner; 85 is a segment for displaying a pictogram indicating that the collected toner storage section is full of collected toner; 86 is a conveyance 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 conveyance status of the paper P, 94 is a segment for displaying pictograms indicating that the paper P in the paper feed cassette 2 is empty, and 95 is a segment for displaying a pictogram indicating that the paper P in the paper feed cassette 2 has been inserted. 96 segments for displaying the lower cover of the copier main body 1; 97 segments for displaying the upper cover in the closed state; 98 segments for displaying the upper cover in the open state; 99 is a display segment of the photosensitive drum 20. Although not shown, a common electrode is provided on the surface facing each of the segments.

Figure 4 shows the overall configuration of the copying machine. That is, 1oo is a main control section composed of a microcomputer, etc., which includes an input section (various keys 72 to 28) of the operation/IP channel 71 and (for example, a toner empty detector 57...572). ) Various detector groups 10
1 is connected via a large sword interface 102.

The main control section 100 controls the operation of the entire copying machine, and controls the static elimination lamp 32 via the driver 103f.
, main motor 35, cleaning 2L/-1' 6
6 T-driven platen lens 104, document table 4
A table forward solenoid 105 that moves the
Table pavkunlenoid 10 that moves the document table 4 backwards
6, paper feed roller solenoid 102, registration roller solenoid 108, toner supply solenoid 109°110,
and developer control circuits 111 and 112. The paper feed roller solenoid 107 and the registration roller solenoid 108 actuate or stop the sliding clutch between the drive source and each roller in order to rotate or stop the paper feed roller 38 and the registration roller, respectively. Toner replenishment solenoids 109 and 110 detect that the toner concentration is below a specified value by toner concentration detectors 5B and 5B, respectively, and then
Toner hopper 56 at 4t+242. ．． 56.
This is to replenish toner from. The developer control circuits 111 and 112 respectively correspond to the developer 241.

242 is selected and the corresponding developing device is brought into contact with and separated from the photoreceptor 20 by controlling the drive. The developing device 1hl control circuit III, 112 is 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, a high voltage transformer 115, and a sheet number display circuit 117 via a dry/'776. The lamp regulator 113 is connected to the exposure run f2.
This controls the energization to %ilJ. The high voltage transformer 115 is used to apply a voltage to the charger 21, transfer charger 25, peeling charger 27fz, etc. as a control signal. The heater control circuit 114 includes a fixing device m
The fixing heater 119 of No. 29 is controlled to be energized to maintain the temperature at a fixing temperature. The sheet number display circuit 117 performs a display operation by selectively lighting up the IJD segment 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 7 and output terminal o.
Output from n, and output terminal OL.

A latch signal, a black signal, and a signal are output from 0C. The liquid crystal drive circuit 120 receives a data signal from the main control section 100 at its input terminal ID in synchronization with the clock signal at 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 terminals 01 to 032 of the liquid crystal drive circuit 120 is connected to the segments 81 to 8 of the liquid crystal light display elements provided in the liquid crystal display/4' channel 80.
32, each of the above segments)
Common electrode 12 provided opposite to s, ""'83m
3 is supplied with the output knob drive signal B of the inverter circuit 122.

The segments 81-8st correspond to the segments 81-99t in FIG. 3(a) as shown in the table below. Furthermore, segments 96 and 99 are connected to the same segment 81.

FIG. 5 shows the liquid crystal drive circuit 120 in detail. That is, shift registers 1311 to JJJ3. are connected in cascade, and a data signal from the input terminal ID is input to the shift register 13c at the first stage, and a clock signal from the input terminal IC is input to each shift register 1311 to 131gg. be done. Thereby, the data signal from the input terminal ID is sequentially transferred to each of the 32 shift registers 1311 to 131st in synchronization with the clock signal from the input terminal IC. Store registers 1321-132g, which hold their respective contents in response to a latch signal from an input terminal IL, are directly connected to each of the shift registers 13c-131H. Each store register 132! ~13
23° is the switch 1331 depending on the content being held.
By controlling the opening and closing of ~133s*, the output terminals O1~03 are driven and 9rus A or B? Output in violation of contract. That is, the opening/closing control is performed so that, for example, when the content of the store register is 1, the drive cell A is output to the corresponding output terminal, and when the store register is 1, the drive cell B is output to the corresponding output terminal.

Next, in the above configuration, FIGS. 6 to 20
The operation will be explained with reference to the figures. In addition, FIGS. 6, 9, 12, 15, and 18 are timing charts, and FIGS. 7, 10, 13, 16, and 19 are liquid crystal displays. Voltage waveform applied to channel 80, eighth
figure.

FIG. 11, 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 to, the main control section 100 starts operating according to the glodarum that has been programmed in advance, and energizes the constant 2n heater 119 of the fixing device #29. Also, at this time, the fixing device 29 has not yet reached the temperature at which it can be fixed, so it is in a standby state, and furthermore, when the power is turned on, the black developing device is automatically selected, so it is in a standby state. and a data signal indicating that the black developer is selected, for example (001000000000
01011011000000000000) (hereinafter referred to as data signal A) is output to output terminal 01). In this case, the above data signal Af is output in synchronization with the clock signal output to the output terminal OC, and the last 32
When the bit-th data transfer is completed, a latch signal is output from the output terminal OL. As a result, the liquid crystal drive circuit 72
(Data signal A is held in store registers 1321 to 13233 in l, and the contents are therefore l''. Store registers 1323.13241321@, 1
3211* 13219+ 1322o and corresponding output terminal Os # 014 * Ots e 017/01
Drive/f pulse A is output from 9/020, which becomes a segment drive signal and is displayed on the liquid crystal display) for each segment of f channel 80) S s * 5t4y 516s 8171
5tar 5tar (applied.

In addition, the store register 132 whose content is "O#"
1.1321 y1324~132@B+ 132L6
+1321s, J 32,1-1323. and the corresponding output terminal Of +01+04″'013 + 015
+ 01+1 * 021″'032 From drive/f
The pulse B is output, and this becomes a segment drive signal of the opposite polarity to drive the valley segment S+ r of the LCD display and channel 8o.
82*S4''-8Is, s151sts
l SH~83. K is applied. At this time, the common electrode 123 of the liquid crystal display panel 8Q and each segment) Ss
A voltage having an alternating current waveform as shown in FIG. 7(f) is applied between e81415III+817181918zo.

As a result, 1 segment S 3 + Sti+ SIs+
S1y+ Sll++ 826, that is, each segment 83□, 95,96°97.81.82 in Fig. 3(a)
．． 99 is in a lit state.

On the other hand, segments other than the above) Ss ass es4~
8B + 8+sy 8ts r S'1 to Ss2 have a common electrode 123 as shown in Figure 7 (c) and (e).
Since voltages in the same phase as S1. and S1 are applied, there is no potential difference between them as shown in FIG. S2
．． s4~8ts e S1s v SIs m 8tt
-8sz + that is, each segment 7 in Figure 3 (,))
832 e841 *841a85~94°98#i Unlit state. Therefore, the display in this case is 1 as shown in FIG. 8, indicating that the device is in a standby state and that the black developing device is selected. As normal priority mode,
The black developer is selected. In this case, segment)
8m (83I) is 1st, 4th as shown in 3rd N6)K. It is highlighted against the black background.

Next, a case where copying is enabled after one standby state and the black developing device is selected in this state will be described with reference to FIGS. 9 to 11. When the temperature of the fixing device f29 reaches a temperature at which fixing can be performed, the selection operation of the black developing device is completed by not operating the color selection switch 22 from the time the power is turned on, or by operating the color selection switch 77 ( Copying is not possible from the time the color selection switch 27 is operated until the selection operation of the developer is completed, and the display described in FIGS. 6 to 8 above is performed.)
When the copying operation becomes possible, the main control unit 100 sends a data signal indicating this state, for example (001000000000010110100000
00000000) (hereinafter referred to as data signal B)
) is output using the same operation as described above. As a result, store register 13J! ,~132sz holds the data signal B, and the store register 132s r13214a1321@* has a content of 1".
13211 #x32** and corresponding output terminal 03 e
014 * Otg e 017 to19 outputs drive/yarus A, which is used for each of the corresponding seven
ss #814 e 8111 #817 s s
, s is applied. In addition, store registers 1321, 1322 + 1324 to 13 whose contents are "0#"
213゜1321s+ 132x@r J 3226~
Output terminal 01 e Ox * 0 corresponding to 13212
4-01se 0110ts * o! A driving signal B is output from O-On-, and this is used to control each segment St l 82 + 84 to 813 r sts.
l 818 rS*o-8ssK applied. At this time, as described above, since the drive signal B is applied to the common electrode 123, the common electrode 123 and the segment) S3+8
A voltage having an AC waveform as shown in FIG. 10(f) is applied between 14*SIs #8tte and . As a result, segment Ss * Sla * Ja #
Each segment 831, 95w, 96e, 97, 81 in FIG. 3(a) is turned on.

On the other hand, segments other than the above) Slys* e84~
813 r Sss r Sts r Szo~Ssg
In this case, the common electrode 123 is connected as shown in FIG.
Since a voltage in phase with is applied, the above segment S1+5z
eS4~sts # 5ill t8ts * 52o
−8s2, that is, each segment 8218 in FIG. 3 (&)
J2 tJ42 H, 841+ 85 to 94.98 is in a non-lighting state. Therefore, the displayed figure in this case is as shown in FIG. 11. By displaying the schematic figure of the copying machine and segment S3 (,831) in white against the black color of the black color, the black developing device is selected. is displayed and the copy operation is enabled.

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 developing unit is completed, so the display is displayed until the selection operation is completed. , the display is similar to the case of selecting the black developer, in addition to the display when the red developer, which will be described below, is selected and ready for copying operation, the segment) 81G (s
z) is simply turned on, so the explanation will be omitted.

When the copying operation becomes possible, the main controller 100 sends a data signal indicating this state, for example, (11)000.
0000000010110100000000000
00:] (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 segment 81 #814 + St
AC waveform voltage is applied only between a j Sty 1Sse, and that segment, that is, each segment 832.95.96, 97.81 in FIG. Each segment of (,) 8 Z # 831 m841 m842 m8
5 to 94°98 is a non-lighting state. Therefore, the display figure in this case becomes as shown in FIG. 14, and by displaying the segment 5l (83) in red together with the schematic figure of the copying machine, the red developing device power (selected and ready for copying operation) is displayed. This will be displayed.

Next, when the black developer is selected, the toner empty detector 57 detects that the toner power in the hole 4561 of the black developer 241 is gone. The case in which this is detected will be explained with reference to FIG. 9, FIG. 11, and FIG. 15 to FIG. 17. When the out-of-toner detector 521 detects out-of-toner (copying operation is still possible even if the toner is gone from the container 561), the nominative 1j control unit 100 outputs a data signal B as a data signal indicating this state. (0010000000000101101000
0000000000) and a signal that lights up the data signal BK segment 54 (841) (0011).
0000000001011010f)0(X)000
+1f)0+lO) data signals (hereinafter referred to as data signals) are alternately output in synchronization with the oscillation circuit 1210 frequency. As a result, when data signal B is output, segment) Ss + 8141'8 violet 111S1
71S seal 9 only, that is, segment 8 in Figure 3 (,)
j, , 95°96.97. When JJ is in the lighting state as shown in FIG. 11 and a data signal is output, the segment Ss e 84 e S14 e St
Only s + Slt + 819 is 1, that is, Fig. 3 (,)
Segment 831 + 841 + 95 + 96.97
．． 81 is in a lighting state as shown in FIG. That is, by lighting the segment 7) 83 (831) in white and flashing the segment 54 (84,) at a predetermined synchronization, it is indicated that there is no toner in the black developing device.

Next, referring to FIG. 12, we will explain the case where the red developing device 242 is selected and the toner empty detector 57□ detects that the toner in the hollow/base 562 of the red developing device 242 has run out. This will be explained with reference to FIGS. 14 and 18 to 20. When the out-of-toner detector 522 detects out-of-toner, the main control unit outputs a data signal C[10000000000001011 as a data signal indicating this state.
010000000000000) and the above data signal C
Added a signal to light segment Sz (#4x) k (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 data signal C is output, segment 81*81ae split mode 316 e 81
7 + S violet 9 only, segment 8 of Tsumashi Figure 3 (,)
32°95.96, 97.81 become lit as shown in Fig. 14, and when data signal E is input, 1
Segment SL# 82 e SI4# SI5# 5
Only taI81718111, that is, segment 832 v 84t + 95 s 96 g in Fig. 3(a)
9718Z enters the lighting state as shown in FIG. That is, segment) Ss (J14z) at a predetermined period.
(Segment)St(8J2)((By lighting up in red, it is displayed 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 the power switch (not shown) is turned on, the black developing device is selected on the main control unit 10θ liquid crystal display channel 80 as shown in FIG.
It displays that it is in a standby state (STI).

Then, the main control unit 100 drives the developer control circuit 111 via the dryer 9103 to move the black developer 241 and bring it into contact with the photoreceptor 201/C (
St2). Next, when the main control section 100 determines that the color selection switch 77 has been turned on (St3), the main control section 100 indicates on the liquid crystal display/channel 80 that the red developing device has been selected and is in a standby state. Display (St4
). Then, the developer control circuit 111 is stopped via the driver 103 of the main controller 100, and the developer control circuit 112 is stopped.
By driving , the iris of the developing device 24 for black color is moved toward and away from the photoreceptor 20, and the developing device 242 for red color is moved and brought into contact with the photoreceptor 20 (S'r5). Note that when the red developer is not selected, the color selection switch 77 is pressed.
When the power is turned on, the main control unit 100 performs an operation in which the red and black colors are reversed.

Next, if the process of step 5 is completed (St6) or it is determined that the color selection switch 77 is not turned on in Stella f3, and the temperature of the fixing device 29 is different from the fixable temperature (8T7), the main control unit 100 LCD display / Gunel 80
As shown in Figure 11 or Figure 14, it is displayed that the selected developing device is ready for copying (St8). Also, in step 7, the fixing device 29
If the temperature is not high enough for fixing, it will return to Stella f3 (^ru 0, and following Step 8,
The main control unit 100 operates a timer (not shown) at 5T.
9) Then, if it is determined that the color selection switch 720 has been turned on (STIO), the process returns to step 4. In addition, in the Stella f9, the main control unit 100 does not judge whether the color selection switch 770 is turned on (STIO) and does not judge that the color selection switch 770 is in the copyable state.
I) When it is determined that the copy key 72 has been input before the timer times out (ST12.13), the main control unit 100
(Segment indicating the possibility of copying of LCD display/Gunel 80)
s, C81) is turned off (ST14), and a normal copying operation consisting of charging, exposure, development, transfer, peeling, and fixing is performed (ST15).

In addition, if there is no paper P in the paper feed cassette 2 or the bottom cover is opened in Step 11, the main control unit 10
0 is a segment indicating that the LCD display/gunnel 80 can be copied)
Ble (8J)? Lights out (ST16),
Return to step 9. After this step 16 is performed, when proceeding to STELLA FXR, the main control unit 100 displays segment S+ of the liquid crystal display/e-channel 80 before proceeding to step 12.
5 (87) is turned on (ST17). Further, when a timeout of the timer is detected in step 12, the process returns to step 1. Due to this timeout, the main controller 1
Although 00 can be copied, no operation is performed for T seconds,
Since it is determined that the user has left the device and the device is returned to its initial state based on this determination, the next user does not have to perform unnecessary operations.

Next, the display when the )ner runs out will be explained using the flowchart shown in FIG. 22. This toner-out display interrupt processing is performed at predetermined timings.

First, the main control unit 100 determines which of the developing devices 241*242 for black and red is selected (ST21). If the black developing device is selected as a result of this determination, the main control unit 100 determines whether the toner out detector 573 detects toner out (ST
22). As a result, when the toner out detector 571 detects toner out, the main control unit 100 displays the liquid crystal display.
As shown in FIG. 17 described above in the main panel 80, the black developing device is selected and a message indicating that there is no toner is displayed (ST23).

In addition, if it is determined in the step 21 that the red developing device is selected, the main control unit 100 detects the toner out detector 52.
2 detects that there is no toner (ST24).
). As a result, when the toner out detector 572 detects the out of toner state, the main control unit 100 selects the red developing device as shown in the liquid crystal display/main panel 80 as shown in FIG. Display that there is no (S
T25).

Then, when the out-of-toner detector "I+572" does not detect the out-of-toner state in steps 22 and 24, and when the Stellar fzs and zs display respective predetermined displays, the internal memory of the main control unit 100 (not shown) is activated. 5T26), 1111
Segment S2 (842) or 54 (842) indicating that the toner on the mother panel 80 has run out.
41) is turned off (ST27). After this light is turned off, when the flag is determined to be 0'' in the step 26, the main control unit 100 determines whether or not a timer TI (not shown) has timed out (5T28), and if it has timed out, sets the contents of the flag to 1''. 0” when .

When it is '0', change it to 1'' (8T29), timer TI
is activated (ST30), and the interrupt processing is terminated. Further, if the timer TI does not time out in step 28, the interrupt processing is ended.

As a result, the above interrupt processing is performed many times (an integer number of times) within the timeout period of timer T1, and each time the timer TI times out, the flag is set to 111#, M()#.
By repeating this, segment S2 (84*) or S4 (1141) is made to blink repeatedly. Note that when the power is turned on, the flag becomes 0'' and the timer TI is activated.

In the above embodiment, there are two developing devices, but a plurality of developing devices other than two may be used. In addition, if multiple developers are out of toner, the segment indicating the developer unit corresponding to the selected developer unit lights up, the segment indicating the developer unit corresponding to the unselected developer units blinks, and the toner [Effects of the Invention] As detailed above in 1-1, according to the present invention, a relatively simple display can be performed. However, it is possible to provide an image forming apparatus that can clearly display the presence or absence of developer in the developing device, and furthermore, can know whether the developing device is out of developer without making a mistake as to which developing device is selected and in operation. 0

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Figure 1 is a sectional view showing the general structure of a copying machine, Figure 2 is a plan view of the operation panel, and Figure 3 (, ) is a diagram of the liquid crystal display. Figure 4 shows an example of the arrangement of segments constituting a schematic diagram of a copying machine displayed on a 9-channel screen; Figure 4 (b) shows an example of a reverse display on a 9-channel LCD display; Figure 4 shows the overall configuration. FIG. 5 is a block diagram schematically showing the structure of the liquid crystal drive circuit, FIG. 6, FIG. 9, FIG. 12, FIG. 15, and FIG. 18 are timing charts for explaining the operation. Figure 7, Figure 10, Figure 1
Fig. 3, Fig. 6, and Fig. 19 are voltage waveform diagrams applied to the dedication display/gunnel, Fig. 8, Fig. 11, Fig. 14, and Fig. 17. and Fig. 20 are diagrams showing each display state, Fig. 21, and Fig. 2
FIG. 2 is a flowchart for explaining the main part of the operation. 241e24 Tomi...Developer, 571. +57t・
・・Toner-free detector, 21 ・・Operation・Yanel, 76
...Liquid crystal display section, 77...Color selection switch, 80.
・・LCD display・Yaneru, 831, 83. ... Segment (developer display candy), 841, 84 snow... Segment (no toner status display Mizuko), Ioo... main control unit, 103... driver, 111, 112... developer Control circuit, 120...Liquid crystal drive circuit.゛

Claims (3)

[Claims] (1) In an image forming apparatus having a plurality of developing devices that apply developer to a formed latent image, a detection means for detecting the presence or absence of developer contained in the developing device and a detection result of the detection means An image forming apparatus comprising: a display means for displaying a developer-free state for each of the developing devices according to the above. (2) Any one of the plurality of developing devices is selected and becomes operational, and in response to the detection result of the detection device, the display device displays the amount of developer for the selected developing device. An image forming apparatus according to claim 1, characterized in that only the absent state is fully displayed. (3) One of the plurality of developing devices is selected and becomes operational, and in response to the detection result of the detection device, the display device displays whether or not there is developer in the selected developing device. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus expresses the state and the developer presence/absence state of the other developing devices in different ways.