JPH03269466A - Toner concentration controller - Google Patents

Abstract

PURPOSE:To shorten a stopping time for recovering a toner concentration when consecutive recording is carried out by providing each means of mode setting, pausing level setting, concentration discriminating, recording action pausing, control, detection level setting, and display. CONSTITUTION:A multi-consumption mode is set by an operating part 2. When a sensor 1 detects a pausing level that the toner concentration is set between a control level and an empty level, or below, a recording action pauses for a prescribed time, and the, is resumed. Pausing is carried out at every recording of the sheet. When a level is a level set between the pausing level and the empty level or below, an empty display is carried out. When the concentration is this detection level or below, the recording action is stopped. When the toner concentration does not exceed the pausing level during the pausing, it is released and normal recording is carried out. When toner consumption per one sheet is a set value or above, the switching is automatically carried out to the multi- consumption mode. A pausing time is varied according to the toner consumption. On the other hand, when the toner concentration is the detection lever or below, the display means displays 'empty'.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to electrostatic! The present invention relates to a toner density control device that controls the toner density of developing images for visualizing images.

[Conventional technology]

Conventionally, in an image forming apparatus such as a copying machine that develops an electrostatic latent image formed on a photoreceptor with toner, the toner concentration in the developing image tank is maintained at a constant level of 1 in order to maintain toner III at an appropriate level.
When the level falls below 111II, toner is replenished from the hopper 371 into the tank 373 (the third
See figure. In such image formation, for example, when a document is continuously copied, the amount of toner replenishment may not be able to keep up with the amount of toner consumption, and the developed area may become thin.

Therefore, there is a second level between the control level and the empty level.
When the toner concentration falls below the second control level, the copying operation is temporarily stopped, toner is replenished, and the toner concentration is restored to a certain level.
A toner density control device that restarts the copying operation has been proposed (Japanese Unexamined Patent Publication No. 105173/1983).
JP-A-1-156782).

[Problem to be solved by the invention]

However, in the toner density control device, it takes time to recover to the constant level after the copying operation is stopped, and the copying operation is stopped for a long time. In other words, when the amount of toner consumed is high, such as continuous copying of Harazuru with many black to black areas, if the continuous copying is being performed at intervals of several seconds, it will stop for several tens of seconds to several minutes. There is a captivation that makes the user feel uneasy. On the other hand, when the toner in the hopper 371 becomes low, the tank 37
The amount of toner supplied to 3 will be reduced.

In this case, it is necessary to notify the user of the need to replenish toner in the hopper 3/71 at an early stage to prevent continuous copying at low density for a long period of time.

The present invention solves the above-mentioned problems by shortening the stop time for recovering toner density when performing continuous recording, and also by using a toner flow rate system WI that prevents continuous recording at low density for a long period of time. The purpose is to provide ¥ik@.

(Means for Solving 11 Problems) In order to achieve the above object, the present invention provides an image forming apparatus that performs continuous recording while replenishing toner when the detected toner density is between the control level and the empty level. , mode setting means for switching settings to high consumption mode, rest level setting means for setting a rest level between the control level and the empty level, and determining whether the toner concentration is below the rest level. First thing to do
a density determination means, a recording operation suspension means for suspending the recording operation for a preset time every time one sheet of recording is completed, and when the toner density changes below the suspension level when the high consumption mode is set; a control means for driving the recording operation pause means; a detection level setting means for setting a detection level between the pause level and the empty level;
a second density determination means for determining whether the toner density is below the detection level; and displaying an empty display when the toner 8 degree changes to below the detection level when the high consumption mode is set; It is equipped with a display means.

Further, in a second aspect of the present invention, a stop means is provided for stopping the recording operation when the toner concentration changes below the detection level.

Further, in a third aspect of the present invention, there is provided a release means for canceling the driving of the recording operation halting means if the toner density does not change to a halting level or more during the driving of the recording operation halting means. a third density determination means for determining that the density is equal to or higher than the control level; and a second density determination means for canceling the driving of the recording operation suspension means when the toner density becomes equal to or higher than the control level while the recording operation suspension means is being driven. and release means.

Further, in claim 5, the mode setting means includes a consumption amount detection means for determining the toner consumption amount per sheet, and a consumption amount determination means for determining that the toner consumption amount is equal to or greater than a preset amount. and switching means for switching the setting to the high consumption mode when the toner consumption amount is set in advance.

Furthermore, in a sixth aspect of the present invention, the pause time of the recording operation is changed in order to match the toner consumption amount and the toner replenishment amount based on the determined toner consumption amount per sheet and the toner replenishment amount per hour. Equipped with means of change.

[Function] According to the toner density control device having the above configuration, the high consumption mode is set and the toner density is 1i1111! When the level changes to below the pause level set between the II level and the empty level, the recording operation is paused for a preset time.
After the above-mentioned time has elapsed, the recording operation is resumed. This pause in the recording operation is performed every time one sheet of recording is completed. Then, when the high consumption mode is set and the toner density changes below a detection level set between the rest level and the empty level, an empty display is performed.

Further, according to the toner concentration-IIllll device of the second aspect, when the toner concentration changes below the detection level, the recording operation is stopped.

Furthermore, according to the toner density control device according to the third aspect, if the toner density does not change beyond the pause level when the recording operation is paused every 15 sheets of recording, the pause in the recording operation is canceled; Normal recording takes place.

Further, according to the toner density i+lI III device of claim 4, when the toner density becomes equal to or higher than the control level while the recording operation is paused after each recording, the recording operation pause is canceled and the recording operation is stopped normally. will be recorded.

Furthermore, according to the toner density control device of claim 5, the amount of toner consumption per sheet is determined, and when this amount of toner consumption is equal to or greater than a preset amount, the setting is automatically switched to the high consumption mode. Ru.

Further, according to the toner density control device of claim 6, the pause time can be changed in order to match the toner consumption amount and the toner replenishment amount based on the toner consumption amount per sheet and the toner replenishment amount per hour. . That is, when the amount of toner consumption is large, the pause time is changed to be longer, and when the amount of toner consumption is small, the pause time is changed to be shortened.

〔Example〕

FIG. 2 is a configuration diagram of a digital copying device Va<image forming apparatus) to which toner density W snow making according to the present invention is applied.

copy! 1121 has a contact glass 22 and a document holder 23 on its upper surface, and is equipped with an optical mechanism and an image forming means P inside.

The optical mechanism is comprised of a light source consisting of a halogen lamp 24 and a reflector plate 25, a reflector 1126, 27, 28, a lens section 29, and a solid silver image element (hereinafter referred to as COD) 30. Then, when a recording (copy) operation is started, the light from the light source is reflected by the original placed on the contact glass 22, and the reflected light is reflected by [126, 27, 28].
After being guided to the lens section 29 through the lens, the light is read by the CCD 30.

The image forming means P includes a laser generator 31, a polygon mirror 32, an anti-@#1L 33, a photoreceptor 34, a charging bag [35, a blank lamp 36, a developing device 37, a transfer device 38, a separation bag M39, a cleaning IAW 40, etc. ing.

Then, a laser beam corresponding to the read document is emitted from the laser generator 31. On the other hand, the surface of the photoreceptor 34 is uniformly charged by the charging device 35, and the polygon mirror 34 is charged uniformly by the charging device 35.
2 and 1i FIIt 33, and an electrostatic latent image is formed. After this, the developing device 37
The electrostatic latent image developed with toner is transferred to the paper by the transfer snowmaking 38, and then transferred to the photoreceptor 3 by the separating device 39.
Separated from 4.

Further, as a paper feeding mechanism, a paper feeding cassette 41, a paper feeding roller 42, and a pair of registration rollers 43 are arranged in order from upstream in the feeding direction, whereby the paper is fed to the photoreceptor 34 and transferred. It will be done. A transport belt 44, a fixing device f45, a discharge roller 46, a paper discharge tray 47, and the like are provided as a mechanism for fixing and discharging the paper after transfer. In addition,
Equipped with an automatic document feeder (not shown), it automatically feeds multiple sheets of documents one after another through the contact glass 22 and the document presser 23m11.
You may also send it to

Next, an example of the configuration of the current II device 37 will be explained using FIG. 3.

The hopper 371 stores toner.

The replenishment roller 372 replenishes toner from the hopper 371 to the tank 373. Stirring roller 374.37
5 stirs and mixes the toner and carrier in the tank 373, and also triboelectrically charges the toner. The developing roller 376 supplies toner to the photoreceptor 34.

Then, the frictionally charged toner is supplied to the photoreceptor 34, and the electrostatic latent image on the photoreceptor 34 is developed with the toner. Further, the hopper 371 can be replenished with toner as appropriate.

Next, a block configuration showing an example of the IIJIl system will be described using FIG. 1.

The toner density sensor 1 is installed at a suitable location around the stirring roller 375 (see FIG. 3), detects the toner concentration, and applies a voltage corresponding to the toner concentration to the central illumination section 111 (hereinafter referred to as CP).
(referred to as U) 11. In addition, toner!
The voltage from the temperature sensor 1 (hereinafter referred to as sensor voltage) decreases as the toner concentration increases, and conversely increases as the toner concentration decreases. The operation unit 2 is used to start copying, set mode, set magnification, set the number of copies, etc. In addition, the operation unit 2 is
Part of the display area includes an empty display area in response to an empty signal from U11, which will be described later. The AD converter 3 converts the image signal from the CCD 30 into a digital signal and outputs it to the image memory 4. Image memory 4
stores the digital signal, and sends the stored contents to the CPU 11.
This is what is output to.

The optical system motor 5' operates the light source of the optical mechanism and the reflecting mirror 26, 27, 28 in response to the 111111 signal from the CPLll.
etc. The toner supply motor 6 is a CPU
The replenishment roller 372 is driven in accordance with the control signal from ii. The toner agitation motor 7 drives the agitation rollers 374 and 375 in response to a control signal from the CPU 11. The paper feed roller motor 8 operates the paper feed roller 42 and the registration roller pair 4 according to the control signal from the CPLJll.
This is what drives the 3rd class. In addition, each of the above motors 5 to
8, the driving force may be transmitted from the main motor using a clutch.

The RAM 9 and ROM 10 are for storing processing programs and processing contents of the CPU 11, as well as preset sensor voltages and the like. That is, the ROM 10 stores toner m111i at a control level that allows copying without toner replenishment.
The corresponding sensor voltage VC.

A sensor voltage v2 at an empty level that makes copying impossible, a sensor voltage v1 (vc<Vl<V2) at a pause level that is between the control level and the empty level and stops copying for a predetermined time tx each time, and paper. The predetermined time fil i x determined for each size is stored.

In addition, the ROM10 has V3 (Vl < V3 < v2
) and the sensor voltage V4 that causes the empty display to be displayed when the high consumption mode is not selected, that is, in the normal mode (note that V4 = V2 or V4 = V
3) is stored in advance.

The CPLll controls the motors 5 to 8 (on and off of the clutch when a clutch is provided in place of the motors 5 to 8), and also performs magnification processing on the image signal read by the CCD 30 as necessary. The laser generator 31 then irradiates laser light according to the image signal after the magnification processing. Further, the CPU 11 outputs a control signal to the toner stirring motor 7 (or the clutch when a clutch is provided in place of the motor 7) to drive the stirring rollers 374 and 375, and when the sensor voltage becomes higher than the voltage Vc. Then, a control signal is output to the toner replenishment motor 6 (or to the clutch if a clutch is provided in place of the motor 6) to drive the replenishment roller 372.

Furthermore, the CPU 11 has a function to determine whether the sensor voltage is voltage ■IVc or 93 or higher, a function to pause the copying operation during the tx waiting time every time each copying operation is completed during continuous copying, and a manual instruction from the operation unit 2. or when the high consumption mode is automatically set based on the pre-scan described later, the sensor voltage changes to voltage v.
1 or more, it has a function of giving a rest time as described above, a function of canceling the rest time when the sensor voltage becomes less than the voltage Vc, and a function of displaying an empty display when the sensor voltage becomes less than the voltage V3. ing. Also, C.P.
tJll has a function of detecting the paper size by a paper size detection sensor (not shown) provided around the paper feed cassette 41 and setting the above-mentioned tx waiting time.

Next, a first embodiment of toner density control with the above configuration will be described using the flowchart of FIG. 4.

In the first embodiment, the setting to switch to the high consumption mode is made by using the operation unit 2.
This is done manually.

First, when the number of copies is set using the operation unit 2 (or multiple originals are set on the automatic document feeder) and continuous recording (copying) is started, in step S1 it is determined whether the sensor voltage V is lower than the voltage Vc or not. That is, it is determined whether the toner concentration is higher than or equal to the optimum toner concentration.Then, if the sensor voltage ■ is lower than the voltage Vc (YES in step S1)
, optimal toner concentration! 1 or more, toner replenishment is not performed by driving the toner replenishment motor 6 (or the clutch if a clutch is provided in place of the motor 6), and the recording (copy) operation is performed in the normal mode in step S2. will be held. That is, after a document is read and an electrostatic latent image is formed on the photoreceptor 34, the electrostatic latent image is developed with toner by the developing device 137 and transferred to the paper.
The transfer paper is fixed and discharged. Next, it is determined in step S3 whether or not the set number of copies have been completed, and if the set number of copies has been completed (YES in step S3), the process of this flowchart ends.

On the other hand, if the number of copies to be copied remains in step S3 (NO in step S3), the process returns to step S1 and it is determined whether the sensor voltage V is equal to or lower than the voltage Vc. Then, in step S1, if the sensor voltage ■ is higher than the voltage Vc (No in step S1), it is lower than the optimum toner concentration, so in step S4 it is determined by the operation unit 2 whether the high consumption mode is set. . At this time, if the high consumption mode is not set (No in step S4).
), it is determined in step S5 whether the sensor voltage V is equal to or lower than the voltage v4.

Then, if the sensor voltage V is lower than the voltage v4 (YES in step S5), step S
While toner replenishment is performed by driving the toner replenishment motor 6 (or clutch) in step 6, the process moves to step S2 and a copying operation is performed.Subsequently, in step S3, it is determined whether or not copying for the set number of sheets has been completed. If the number of copies to be copied remains, the process returns to step S1.

On the other hand, if the sensor voltage V is equal to or higher than the voltage V4 in step S5 (NO in step S5), a toner empty display (hereinafter referred to as "empty table small") is performed in step S7, and continuous copying is prohibited in step S8 and single copying is performed. The mode is switched to the one-shot copying mode, and the copying operation as a one-shot copying operation continues to be possible (step S2). Thereafter, in step S3, it is determined whether copying for the set number of sheets has been completed, and if the number of sheets to be copied remains, the process returns to step S1.

On the other hand, if the high consumption mode is set in step S4 (YES in step S4), that is, in the high consumption mode, the amount of toner consumed per sheet of paper is, for example, on a preset placement. , In step S9, it is determined whether the sensor voltage V is below the voltage V1L1, and if the sensor voltage V is below the voltage ■1 (YES in step S9),
While toner replenishment is performed by driving the toner replenishment motor 6 (or clutch) in step Sv in order to maintain the toner concentration, a copying operation is performed in step S2.

Thereafter, in step S3, it is determined whether or not copying of the set number of sheets has been completed, and if the number of sheets to be copied remains, the process returns to step S1. On the other hand, in step S@, the sensor voltage V
changes to a voltage of 91 or more (NO in step S9),
In step St1, it is determined whether the sensor voltage V is equal to or lower than the voltage v3.

That is, if the sensor voltage V is equal to or higher than the voltage V3 (NO in step S11), although the toner concentration has not decreased to the empty level, if the toner concentration further decreases due to the repetition of the copy operation, normal copying will no longer be possible. , the carrier deteriorates. Therefore, the toner 11 degrees is the empty level, that is, the sensor voltage ■ is the voltage v2
When the sensor voltage ■ changes to voltage 93 or more in order to replenish the toner before the hopper 371
Wait until the toner is refilled. Then, when the toner is replenished (YES in step S17), step S1
Return to

On the other hand, as mentioned above, in the high consumption mode, the amount of toner consumed is large, so if copying operations are performed continuously in the high consumption mode, the toner supply cannot keep up and the toner IIr! I gradually decreases. Therefore, when the sensor voltage VSt pressure v1 or higher is reached, the copying operation is stopped for the tx waiting time every time one copy is completed while toner is being replenished, and the toner concentration is restored. That is, if the sensor voltage ■ is equal to or lower than the voltage ■3 in step Sn (YES in step Sn)
, In order to recover from the toner S degree shortage in a short time, step St
While replenishing toner by driving the toner replenishment motor 6 (or clutch), the copying operation is paused for a preset tx waiting time, for example, several seconds. And the above t
After x11m has elapsed, the copy operation is performed in step S13, and in step S14 it is determined whether or not the copying of the set number of sheets valve has been completed. If the copying of the set number of sheets valve has been completed (YES in step S14), the main copy Processing of the O-chart ends. It should be noted that toner replenishment during a pause in the copying operation is performed during tx waiting time replenishment from the time when voltage 91 or higher is detected until the time when voltage Vc is detected, and replenishment is stopped when the voltage is lower than Vc.

On the other hand, if the number of copies to be copied is PJ-) in step S14 (No in step Sw), it is determined in step Ss whether the sensor voltage V is less than the voltage Vc, and if the sensor voltage V is more than the voltage Vc ( No in step S15),
Returning to step S11 again, it is determined whether the sensor voltage V is equal to or lower than the voltage v3.

Then, as long as the sensor voltage V does not rise above the voltage V3JX, the tx waiting time copy operation continues to be suspended (step 512). On the other hand, in step Ss, the sensor voltage V is
c (YES in step sII), that is, when the toner concentration recovers to the ailJ m111 level by toner replenishment, the pause in the copy operation is canceled and the copy operation is performed in the normal mode (step S2).

Here, the operation when the sensor voltage (2) becomes equal to or higher than the voltage (1) in the high consumption mode according to the present invention will be described with reference to FIG.

First, when the continuous copy operation in the normal mode is started at time t1 when the sensor voltage V is the voltage Vc, the toner 11 degrees gradually decreases and the sensor voltage V increases from the voltage Vc. And t211i? At the point, the sensor voltage V becomes the voltage ■1
When the value exceeds 1, the copying operation is stopped for an amount of jxlR every time one copy is completed, and during this period, toner is replenished by driving the toner replenishment motor 6 (or clutch). Therefore,
This 1xBi@ and the sensor voltage ■ will decrease as shown in the figure.

Thereafter, the copying operation is restarted, and when the next copying operation is completed, toner replenishment at tx is performed again.

Then, when the toner concentration gradually increases and the sensor voltage V becomes equal to or lower than the voltage Vc at time t3 (YES in step S5), the pause in the copy operation is canceled, the mode returns to normal mode, and the copy operation is performed without pausing. (Step S2
).

After that, continuous copying is performed in the normal mode (loop from step 81 to step S3), and when the amount of toner remaining in the hopper 371 becomes low at time t4, the amount of toner supplied to the tank 373 decreases and the toner concentration gradually decreases. decreases,
The sensor voltage V gradually increases. When the voltage v1 is reached at time t5, the copying operation is stopped again for the tx waiting time every time one copy is completed, and during this time the toner supply motor 6 (
Toner replenishment is performed by driving a clutch (or a clutch).

Furthermore, when the toner concentration decreases and reaches the voltage ■3 at time t6, an empty display is performed, and the hopper 371
waits until toner is replenished (steps Ss, S
v).

Next, a second embodiment of toner density control will be described using the flowchart of FIG. 6.

In the second embodiment, the sensor voltage ■ is the voltage ■ in the high consumption mode.
1 or more, and when the sensor voltage V changes to voltage v1 or more again while the tx waiting time copy operation is paused, the copy operation pause operation is canceled and normal copying is performed. This is what I did.

That is, when continuous copying starts and the sensor voltage V is lower than the voltage VC (YES in step 821), the copying operation is performed without toner replenishment (step 522), and the copying of the set number of sheets valve is completed. If the answer is YES in step Sza), the processing of this flowchart ends. On the other hand, if the number of sheets to be copied remains (NO in step S23), the process returns to step S21, and if the sensor voltage ■ is equal to or higher than the voltage Vc (NO in step S21), the process returns to step S21.
, it is determined whether the high consumption mode is set, and if the high consumption mode is not set (step S
24), it is determined whether the sensor voltage V is less than the voltage ■4 (step 525), and if the sensor voltage ■ is less than the voltage V4 (step S25 is YES).
), while replenishing toner by driving the toner replenishment motor 6 (or clutch), the process moves to step S22 and a copying operation is performed, and if the number of sheets to be copied remains (No in step S23), the process proceeds to step S22. Return to 21.

On the other hand, if the sensor voltage ■ is equal to or higher than voltage 94 in step S25 (No in step 825), an empty display is performed, continuous copying is prohibited, and the mode is switched to single-shot copying (steps 827 and 528), and single-shot copying is performed. copy operations are still enabled (step 522).
). If the number of sheets to be copied remains after this (No in step S23), the process returns to step S21.

On the other hand, if the high consumption mode is set (step S
24: YES), Step S29 determines whether the sensor voltage V is below the voltage v1, and if the sensor voltage V is below the voltage 1, then the toner supply motor 6 (or clutch) is driven. A copy operation is performed while replenishing toner (step 830.
522), if the number of sheets to be copied remains (No in step S23), the process returns to step 821. on the other hand,
When the sensor voltage V changes to voltage V1 or higher in step S29 (No in step S29), step S3t
In step S31, it is determined whether the sensor voltage V is equal to or less than voltage ■3, and if the sensor voltage V is equal to or higher than voltage 93.
(No), in order to replenish toner before the toner density reaches the empty level, an empty display is performed (step 5xa), and the system waits until the toner is replenished (step S37), and when the toner is replenished, step S3
7), the process returns to step 321.

On the other hand, if the sensor voltage V is lower than the voltage ■3 in step S31 (YES in step S31), the toner replenishing motor 6 (or clutch)
While replenishing toner by driving, the copying operation is paused for 1x time, after which the copying operation is performed, and it is determined whether or not the copying of the set number of sheets valve is completed (steps 832 to 534). Then, if the copying of the set number of valves is completed (YES in step S34)
, the processing of this flowchart ends. Note that toner replenishment during a pause in the copying operation is performed using the voltage
txl from the time of detection of 1 or more to the time of detection of voltage Vc
Ilil is replenished, and when the voltage is below ■cg, the supply is stopped.

On the other hand, if the number of sheets to be copied remains (step S
34: NO), and in step S35, it is determined whether the sensor voltage ■ is less than or equal to the voltage V1, and the sensor voltage
If it is below (YES in step S35), the process returns to step S32. That is, when the sensor voltage V is lower than the voltage V1, the toner concentration has not been recovered, so the copying operation is suspended for the time tx while continuing toner replenishment by driving the toner replenishment motor 6 (or clutch). Then, unless the sensor voltage V becomes higher than the voltage v1g in step S35, the copying operation is stopped every time one copy is completed until the copying of the set number of copies valve is completed (steps 832 to S35).

On the other hand, when the sensor voltage ■ becomes equal to or higher than the voltage ■1 in step S35 (No in step S35), step S
At step 18, it is determined whether the sensor voltage ■ is less than or equal to the voltage v2. If the sensor voltage V is equal to or higher than the If1 pressure v2 (NO in step S38), the toner concentration is at the empty level, so an empty display is performed so that the toner is replenished, and the toner is stored in the hopper 371. The process waits until the toner is replenished (steps S39, 540), and when the toner is replenished (YES in step 840), the process returns to step 821.

On the other hand, if the sensor voltage VS'l pressure is equal to or lower than v2 in step 83g (YES in step 838), toner replenishment is performed by driving the toner replenishment motor 6 (or clutch), and at the same time, a copying operation is performed (step S41).
．． 542). That is, even though the copy operation is stopped and toner is replenished (step S32.533), the toner density decreases because the toner in the hopper 371 is insufficient, so the empty display ( In order to perform step 539), normal copying is performed without pausing the copying operation so that the toner density reaches the empty level in a short period of time.

Then, in step S43, it is determined whether copying of the set number of sheets has been completed, and if the number of sheets to be copied remains (No in step S43), the process returns to step S38. That is, unless the copying of the set number of valves is completed (YES in step S43), the process in step 8 is continued until the sensor voltage V becomes equal to or higher than voltage v2 (NO in step S3a) and the empty display (step 539) is performed.
38. The loop from step 841 to step S43 is repeated, and when the copying of the set number of valves is completed, step S
43: YES), the processing of this flowchart ends.

Here, regarding the operation according to the present invention, in the second embodiment, when the high consumption mode is set and the sensor voltage ■ exceeds the voltage v1 and the copy operation is paused, the sensor voltage V increases again to the voltage 91 or above. The case of change will be explained using FIG. 7.

First, when the continuous copying operation is started at time t7 when the sensor voltage ■ is at the voltage Vc, the toner density gradually decreases and the sensor voltage ■ increases from the voltage Vc. Then, when the sensor voltage V becomes equal to or higher than the voltage v1 at time t8, the copying operation is stopped for the tx waiting time every time one copy is completed, and toner replenishment is performed by driving the toner replenishment motor 6 (or clutch). This stopping of the copying operation and toner replenishment are continued every time the copying operation is completed until the set number of copies are completed (loop of steps 832 to 835), and the toner concentration gradually increases.Then, the toner concentration exceeds the control level. When this happens, toner replenishment is stopped, and when the temperature drops below the control level, toner replenishment is restarted.

On the other hand, during the processing of the loop from step 832 to step S35, when the amount of toner remaining in the hopper 371 becomes low, for example at time ts, the toner auxiliary device to the tank 373 decreases and the toner concentration gradually decreases, so that the sensor voltage V gradually increases and reaches a voltage of 91 or higher again at time t10. At this time, the pause in the copy operation is canceled and normal copying resumes.

The toner density further decreases with subsequent copying, and t
When the voltage v2 is reached at time point 11, an empty display is performed (step 53a), and the copying operation is not performed until the hopper 371 is replenished with toner (step 837).

Next, a third embodiment of toner density control will be described using the flowchart of FIG. 8.

In the second embodiment, when the sensor voltage V is equal to or lower than the voltage v1 in step S35 (YES in step S35), the process moves to step 832, but in the third embodiment, the sensor voltage If the voltage ■ is less than or equal to the voltage V1 (YES in step 865), it is determined in step S74 whether the sensor voltage V is less than or equal to the voltage Vc. When the sensor voltage (2) is below the voltage Vc, the copying operation returns to normal, and when the sensor voltage (V) is above the voltage Vc, the copying operation is stopped and toner is replenished.

That is, when the high consumption mode is set (YES in step Ss*) and the ton+1-11 voltage V is equal to or higher than voltage 91 (No in step S5+1), the sensor voltage vIf
If the i voltage is 3 or less (YES in step Sa1),
The copy operation is paused for the tx waiting time, the toner is replenished, and the copy operation is performed after the txH time (step 51).
12.863). Then, when the copy operation is paused, if the sensor voltage V becomes equal to or less than the voltage v1 again (YES at step 865), it is determined in step S74 whether the sensor voltage V is equal to or less than the voltage Vc, that is, the toner density is 111II1. It is determined whether the level is higher than the level. Then, the copy operation is stopped and toner is replenished (step S62).
．． 563), if the toner 11 degrees has increased and recovered to the control level or higher (YES in step S74),
A normal copying operation is performed without pausing the copying operation (step 552). On the other hand, if the toner concentration is below the control level, the process returns to step 5111.

That is, the sensor voltage V is equal to or higher than voltage 93 (step S6
1: No) or voltage Vc or lower (Step 874: YE)
S), or the set number of copies has been completed (step S).
64 (YES) L, unless the sensor voltage V is voltage 91
Until the above changes (No in step S65), the tx waiting time copying operation is paused and toner replenishment continues for each copying operation (step Saz, 5a3).

Here, regarding the operation according to the present invention, in the third embodiment, when the high consumption mode is set and the sensor voltage V exceeds voltage 91 and the copy operation is paused, the sensor voltage V becomes equal to or higher than voltage V1 again. The case where this occurs will be explained using FIG.

When the continuous copying operation is started when the sensor voltage ■ is 112 of the voltage Vc, the toner concentration gradually decreases and the sensor voltage ■ increases from the voltage Vc, and the toner is replenished by driving the toner replenishment motor 6 (or clutch). The copy operation is then performed. Then, when the sensor voltage ■ exceeds the voltage v1 at the time of ttI, the copying operation is paused for t x Rm every time one copy is completed, and tx Rm after each copying operation is completed.
The toner concentration gradually increases due to toner replenishment during the waiting period, and the sensor voltage (2) decreases to the voltage Vc (at t% time).

After this, for example, when the amount of toner remaining in the hopper 371 becomes low at time t15, the amount of toner supplied to the tank 373 decreases and the toner concentration gradually decreases, and the sensor voltage V gradually increases until it reaches voltage 91 or higher at time t16. Become. At this time, the copy operation is again suspended for 1x time. However, due to the decrease in the toner supply amount, the toner density cannot be increased sufficiently, and at time t17, which is the next copy operation, the sensor voltage V becomes equal to or higher than the voltage ■1 again. Therefore, the pause in the copying operation is canceled and normal copying is resumed, and the toner density further decreases as the copying operation continues.

And 1. When the voltage v2 is reached at this point, an empty display is displayed and the copying operation is not performed until the hopper 371 is refilled with toner (step S39.5).
40).

Next, toner concentration! 10th Example of J Control
This will be explained using the flowchart shown in the figure.

In the fourth embodiment, first, a pre-scan is performed to calculate the toner consumption amount T per sheet, and when the calculation result exceeds a preset lTx, the high consumption mode is automatically set. The processing shown in the flowchart of FIG. 4, FIG. 6, or FIG. 8 is performed. The black and white inversion mode and magnification are set using the operation unit 2.

Pre-scanning is started in step S81, and the CCD 30
The original is read while being scanned, converted into digital (image) signals, and sequentially stored in the image memory 4. Step SIL! Then, the document size is detected. This document size may be set by the operation unit 2 or automatically calculated. One possible method for automatically calculating the document size is to calculate the document size based on the fact that at least the four corners of the document are white. That is, the back side of the document presser 23 is painted in a neutral color such as gray, the four corners (white) of the document are identified by pre-scanning, and the document size is calculated from these four corners. It is also conceivable to scan a document with a detection unit in which photo sensors for double-bound books are arranged, and detect the size of the document based on the presence or absence of reflected light from the document.

Subsequently, in step S83, the number of black pixels is counted from the image signal stored in the image memory 4 according to the scan,
It is determined in step 864 whether or not the prescanning has been completed. If the prescanning has not been completed (No in step Sa4), the process returns to step Sa2 and the document size is detected. When the pre-scanning is completed (YES in step Sa4), it is determined in step Sa5 whether the black and white inversion mode is set.

If the black and white inversion mode is not set (step S8
5: NO>, in step Sas, the toner consumption amount T per sheet is calculated as shown in the following formula. Note that the amount of toner consumption per number of black pixels is omitted for the sake of explanation.

T - (Magnification) .

T-(Magnification>×((Total number of pixels of original)-(Number of black pixels)) In step Saa, it is determined whether the toner consumption amount T calculated in step Sa6 or step 8v is greater than the preset value Tx. If the toner consumption amount T is greater than the amount Tx (YES in step S&B), the high consumption mode is set in step S as, and then the process shown in FIG. 4, FIG. 6, or FIG. 8 described above is performed. On the other hand, in step S, the toner consumption amount T becomes the amount T.
If it is less than × (No in step Saa), the process shifts to the flowchart of FIG. 4, FIG. 6, or FIG. 8 without setting the high consumption mode.

That is, if the high consumption mode is set, step S4 in FIG. 4 (step S24 in FIG. 6, step S8 in FIG.
In the figure, the result is YES in the branch of step S54>, and the process moves to step S9 (step 829 in FIG. 6, step 559 in FIG. 8). On the other hand, if the high consumption mode is not set, step S4 in FIG. Step 824
, step S54> branch is No, and step S85
The process moves to step 825 in FIG. 6 and step 555 in FIG. 8.

Further, as a fifth example of the toner concentration all 'm, when the toner consumption amount is relatively small in the high consumption mode, t
x 1 m may be shortened to stabilize the toner concentration (see the broken line in FIG. 5), stabilize the toner concentration, and shorten the time until copying is completed. That is, based on the toner consumption per sheet of 11 calculated using the flowchart in FIG. 10 and the preset toner replenishment amount per time, the interval i x fI where the toner consumption amount and toner replenishment amount match is calculated. .

As a result, when the toner consumption amount T is large (the tx waiting time becomes longer), and conversely, when the toner consumption amount T becomes smaller, the tx waiting time becomes shorter.

Note that in this digital copying machine that uses the image memory 4, pre-scanning is not particularly necessary, and mode setting and image formation can be performed based on the image signal in the image memory 4 obtained by the main scanning. . Further, in the above description, the toner concentration ill l @ setting was applied to a digital copying machine, but it can also be applied to an image forming apparatus such as a printer.

Further, in the flowcharts of FIGS. 4, 6, and 8, when toner is replenished in step Sv (step 837 in FIG. 6, step 557 in FIG. 8) (step Sv, step S37, or step S57) DeYE
S), step S1 (step S21 in FIG. 6, step 551 in FIG. 8), but when the toner is replenished, step 511 (step S in FIG. 6)
31, the process may return to step 561) in FIG.

In the flowcharts of FIGS. 6 and 8, the sensor voltage V
It is now possible to select whether to perform an empty display by determining whether the voltage is below voltage v2, or to pause the copy operation and replenish toner. The above selection may be made by determining the following.

In this case, the empty display due to a decrease in toner ati occurs earlier (for example, in FIG. 7, ts
(time t20 in FIG. 9), the need for toner replenishment can be notified earlier.

Further, by delaying the copy start time by a predetermined time, the time tx may be given every time one copy is completed. Further, the toner concentration may be detected after the copying operation is stopped or after the copying operation is completed.

[Effects of the Invention] The present invention provides the toner 11 that is replenished when the high consumption mode is set.
When the temperature changes below the preset pause level, the recording operation is paused for a very short preset time after each recording, so toner can be replenished while recording at the same time, reducing toner consumption. Even in the worst case, recording is performed at equal intervals, preventing irregular operations such as long pauses during continuous recording as in the past, and providing a sense of security to the user. In addition, when the toner concentration changes below the detection level set between the rest level and the empty level when the high consumption mode is set, an empty display is displayed, so the user is notified of the need for toner replenishment at an early stage, and the toner concentration remains low for a long period of time. Therefore, it is possible to prevent continuous recording from being carried out, and it is possible to prevent deterioration of the carrier.

In addition, when the toner 11 degrees changes below the detection level, the recording operation is stopped, which prevents continuous recording at low density for a long time before replenishing the toner, and reliably prevents carrier deterioration. can.

Furthermore, if the toner concentration does not change above the pause level while the recording operation is paused, the pause in the recording operation is canceled, so that when the toner supply amount decreases, the toner 11 degrees will drop to the display level. This saves time and allows the user to be notified earlier of the need for toner replenishment.

Additionally, if the temperature exceeds the control level while the recording operation is being paused, normal recording will continue without the recording operation being paused, so the recording time will be shorter after the toner density has recovered due to the recording operation being paused. It is possible to shorten the time.

Roughly calculates the amount of toner consumption, and when the toner consumption amount is set in advance, it is automatically set to high consumption mode, so even if the amount of toner consumption is large, it is sure to record at equal intervals. This can prevent excessive reduction in toner concentration.

Further, since the downtime is changed based on the toner consumption amount per sheet and the toner replenishment amount per time, it is possible to obtain the minimum downtime and also to obtain stable toner density.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram of a control system of a toner density control device according to the present invention, FIG. 2 is a configuration diagram of an image forming apparatus to which the toner concentration control device according to the present invention is applied, and FIG. 3 is a block diagram of a control system of a toner concentration control device according to the present invention. The configuration diagram of such a developing device, FIG. 4, shows a toner density of 1111.
A flowchart showing a first embodiment of the operation of the 111I device, FIG. 5 is a timing chart for explaining the operation of the flowchart in FIG. 4, and FIG.
7 is a timing chart for explaining the operation of the flowchart in FIG. 6, and FIG. 8 is a flowchart showing a second embodiment of the operation of the 1ill device, and FIG. 8 is a third embodiment of the operation of the toner degree control device. FIG. 9 is a timing chart for explaining the operation of the flowchart of FIG. 8, and FIG. 10 is a flowchart showing a fourth embodiment of the operation of the toner 11 degree control device. 1... Toner water level sensor, 2... Operation unit, 11...
・Central control unit (CPU), 34... Photoreceptor, 37...
- Developing device, 371... hopper, 372... replenishment roller, 373... tank.

Claims (1)

[Claims] 1. Mode setting means for switching the setting to a high consumption mode in an image forming apparatus that performs continuous recording while replenishing toner when the detected toner density is between the control level and the empty level. a pause level setting means for setting a pause level between the control level and the empty level; a first density determination means for determining whether the toner density is below the pause level; recording operation suspension means for suspending the recording operation for a preset time; and control means for driving the recording operation suspension means when the toner density changes below the suspension level when the high consumption mode is set. , a detection level setting means for setting a detection level between the pause level and the empty level; a second density determination means for determining whether the toner density is below the detection level;
A toner concentration control device comprising: display means for displaying empty when the toner concentration changes below the detection level when the high consumption mode is set. 2. The toner density control device according to claim 1, further comprising a stop means for stopping the recording operation when the toner density changes below a detection level. 3. The toner concentration control device according to claim 1 or 2, further comprising a release means for canceling the driving of the recording operation halting means if the toner concentration does not change to a halt level or higher while the recording operation halting means is being driven. A toner density control device characterized by: 4. The toner density control device according to claim 1, 2 or 3, further comprising: a third density determination means for determining whether the toner density is equal to or higher than a control level; and a toner density control device while the recording operation stopping means is being driven. 1. A toner density control device comprising: a second release means for releasing the driving of the recording operation stop means when the level exceeds the level. 5. The mode setting means includes a consumption detection means for determining the toner consumption per sheet, a consumption determination means for determining that the toner consumption is greater than or equal to a preset amount, and a consumption determination means for determining the toner consumption per sheet. 5. The toner concentration control device according to claim 1, further comprising a switching means for switching the setting to the high consumption mode when the toner concentration is equal to or greater than a preset amount. 6. In the toner density control device according to claim 5, the recording operation is stopped in order to match the toner consumption amount and the toner replenishment amount based on the determined toner consumption amount per sheet and toner replenishment amount per time. A toner concentration control device comprising a pause time changing means for changing the time.