JP3141335B2 - Toner replenishment method in development system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the toner concentration in a developer.
Toner concentration sensor to detect and control connected to the subsequent stage
Means for toner supply in a developing system having means for controlling toner concentration, when a developer is not attached or a connector for a developer is forgotten, and toner is supplied to the developer.
It relates to a toner supply method in developing <br/> stearyl beam that may sense that mechanism side of the toner empty detection, and the like.

[0002]

2. Description of the Related Art Conventionally, a developing device using a two-component developer composed of, for example, a carrier and a toner is known. In this type of developing device, a toner is stored in a developing container containing the developer at a predetermined mixing ratio. The toner container is connected via a replenishing mechanism, and a toner concentration sensor is disposed in the developing container. A mixing ratio of the toner and the carrier generated each time the toner is consumed from the developing container by a predetermined electrophotographic developing operation. Is detected by a toner density sensor, and toner is sequentially supplied from a toner container into a developing container while driving and controlling the toner supply mechanism based on the detection signal. As a sensor for detecting the toner density, a magnetic permeability sensor is generally used, paying attention to the fact that the magnetic permeability of the carrier is different from that of the toner. 2-9
In No. 3568, a vibration waveform component corresponding to the development density is output from the sensor while rubbing and agitating and mixing the surface of the detection sensor with a stirring blade, and the toner replenishing mechanism is driven while comparing the waveform component with a reference density level. It is configured to perform control.

That is, the above-described technique will be described in detail with reference to FIG. 3. When the detection surface of the sensor is periodically rubbed using a stirring means or the like in a developing container, a vibration component L 'corresponding to the density control width is used. And a pulse output corresponding to the toner density is obtained by comparing the output waveform having the vibration component with the reference level signal S ′. When the pulse output is at the level Hi, (A '), The toner supply operation is continuously performed, and if the output does not shift to the pulse state even after the lapse of a predetermined time, the toner container is determined to be empty and development is stopped (A'), while the pulse output is When output as ON / OFF pulse (B '
In ()), replenishment control is performed intermittently in response to the pulse output, and when the pulse output is at the level LOW (C '), the replenishment operation is completely stopped, so that accurate replenishment without overshoot is achieved. The operation can be performed and the empty state of the toner container can be detected.

[0004]

In a printer or other electrophotographic apparatus incorporating the developing device, the developing device is detachably attached to the main assembly of the apparatus in order to facilitate maintenance. However, in such an apparatus, in order to supply power and receive signals to the sensors and the like incorporated in the developing apparatus, a controller section of the main body and a sensor section in the developing unit are connected via a connector. It is configured to connect. However, since the development unit is generally replaced at the user stage, there is a case where only the unit is mounted and the connection of the connector is forgotten.

In such a case, since no detection signal is output from the unit side, an output operation similar to the case of the level Hi is performed and a malfunction such as continuous toner supply operation occurs. There is. For this reason, in the above-mentioned apparatus, it is necessary to provide a detection mechanism for detecting whether the developing unit is not mounted or the connector is not connected. However, such a configuration is not preferable because the configuration of the apparatus becomes complicated.

In the above-mentioned prior art, since a vibration waveform is generated by a mechanical stirring means, an accurate vibration waveform corresponding to a density control range is obtained depending on the environment inside the apparatus, the degree of charging of the developer, and the like. And the density control range may fluctuate due to the variation of the waveform.

In order to achieve the technical object, the present invention utilizes an existing toner density sensor to control toner density and to easily detect whether a developing unit is not mounted or a connector is not connected. toner in the system
The purpose is to provide a supply method . DOO in the development system that allows other objects also generates a vibration waveform of from the sensor by mechanical means, also accurately even if a variation occurs in the waveform toner concentration control of the present invention
It is to provide a method of replenishing nuts .

[0008]

SUMMARY OF THE INVENTION The present invention achieves the above object by effectively utilizing a toner density sensor for mainly detecting a toner density. The present invention has a toner concentration sensor for detecting the toner concentration in the developer and control means connected to the subsequent stage, and takes out the output from the toner concentration sensor as a vibration waveform, and obtains the upper and lower peaks of the vibration waveform. with value forms possible variation in the vertical direction according to the change of the toner concentration based on the constant voltage level, there on the peak value before Symbol vibration waveform to said constant voltage level from a higher position in the case of the required toner replenishing at If the toner density is low, continuous replenishment mode, the peak on the vibration waveform
Value is higher than the constant voltage level
When the toner concentration is higher than in the continuous supply mode, toner is supplied in the intermittent supply mode , and the upper peak value of the vibration waveform is lower than the constant voltage level.
The toner supply method in the developing system configured to stop the toner supply when it is at a lower position .
The vibration waveform is compared with the constant voltage level. When toner supply is not required, an L level analog output is sent out. When toner supply is required, the toner density is changed from a high toner density to a low toner density. In addition to obtaining a density detection output in which the pulse width becomes longer toward the state, when the developing device is not mounted or the developing device connector is not connected,
A calculation input detection step in which a Hi-level analog output is sent to the control means instead of the vibration waveform; and in the intermittent supply mode, when the density detection output is a pulse output パ ル ス, a subsequent adjacent pulse output A calculation step of obtaining a calculation value (Y) obtained by adding the correction width A to the pulse width of the pulse output 、 so as not to be integrated with the pulse width of the pulse output Χ, and a signal width of the calculation value (Y) in the calculation step. A toner replenishing step of replenishing toner in the developing device, and in the calculation input detecting step, the density detection output detects the necessity of toner supply by obtaining a pulse oscillation waveform,
By the analog output continuing at the Hi level,
It is characterized by detecting that the developing device is not mounted or the developing device connector is not connected.

As a result, similarly to the above-described prior art, in a case where the oscillation waveform is compared with a constant level reference level signal to obtain a pulse output for density detection, as will be described in detail later. Developing unit not installed or developing unit
If the connector is not connected, replace the vibration waveform
A Hi-level analog output is sent to the control means.
So that the toner density sensor can be detected only when the developing device is not mounted or the developing device connector is not connected.
The operation input coming into the control means connected to the subsequent stage of the sensor is continuously at the level Hi, so that the abnormality detection can be easily performed.

Further, the present invention relates to the vibration waveform and the one
Comparing with the constant voltage level, if toner supply is not necessary
Outputs an L level analog output and supplies toner
If necessary, change the toner density from high to low.
Concentration detection where the pulse width increases as going to a lower state
Is configured to obtain an output for the
In the detecting step, the output for detecting the concentration is a pulse vibration wave.
Detecting the need for toner supply by obtaining shape
Can be.

In the intermittent supply mode,
When the density detection output is pulse output Χ,
The pulse output so that it is not integrated with the pulse output
Calculated value (Y) obtained by adding the correction width A to the pulse width of Χ
And the operation value obtained by the operation step
Replenishing toner in the developing device based on the signal width of (Y)
Therefore, the normal toner density control is based on the density detection output.
Calculated value (Y) obtained by adding the correction width A to the pulse width of Χ
And the signal state of the pulse output Χ, the driving control of the replenishing mechanism for replenishing the toner in the developing device can be performed with higher accuracy than in the prior art.

At a predetermined time in the toner supply stage,
If the toner supply operation continues for more than
If the toner on the mechanism side that supplies toner is empty
It is also an effective means of the present invention to provide a toner empty detection means for detection .

[0013]

The operation of the present invention will be described with reference to FIG. (A) shows a state in which the toner density is low (high magnetic permeability). In this case, the pulse output and the pulse output obtained by comparing the oscillation waveform L output from the toner density sensor with the reference density level voltage S are shown. The digital output Χ corresponding to this is an ON / OFF pulse unlike the prior art,
The calculated value (Y) obtained by adding the width A becomes a Hi level signal, and continuous toner supply is performed. Therefore, in the case of (A), even if the vibration waveform L varies, the replenishment control signal of the Hi level signal can be obtained uniformly within the range of the correction width A, and the variation of the vibration waveform L can be compensated. If the calculated value of the calculated value (Y) remains at the Hi level for a time set by the timer, it is determined that the toner is empty as in the related art. (B) shows a state where the toner density is within the control range, correction width as calculated value obtained by adding the correction width A in this case the digital output chi (Y) is a digital pulse-like Since the set value of A is set, intermittent toner supply similar to the related art is performed, and overshoot is prevented. (C) shows a state in which the toner density is high. In this case, since the digital output と becomes a LOW level signal, the operation value (Y) also becomes a LOW level signal corresponding to this.
The toner supply is stopped. Therefore, in the above control, when the toner concentration is high , or when the toner concentration is within the control range.
That case, for all cases where the toner density is low, the digital output Χ that do not Hi continuously, the control means
When the high level analog output is continuously transmitted to the side , it can be easily determined that the developing device is not mounted or the developing device connector is not connected.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. Not just. FIG.
1 shows a main configuration around a developing device according to an embodiment of the present invention, and a mechanical configuration thereof will be briefly described. 1 is a developing container containing a carrier and a toner at a predetermined density ratio. A developing sleeve 3 containing a mag-roll (not shown) is rotatably supported on the opening side facing the above, and a toner container 12 is attached above the developing container 1 via a partition plate 5. A slit opening 6a is provided on the bottom side of the tapered guide concave portion 6 formed at an arbitrary position of the partition plate 5, and a toner replenishing roller 7 covered with a sponge is rotatably attached to the opening 6a. A supply motor 8 whose rotation can be controlled by a drive circuit 9 is connected to the roller 7.

On the other hand, the developing container 1 is provided with the slit opening 6
After the stirring blade 11 is attached to the developing sleeve 3 on the downstream side of the developing member 3 and a rotatable member 20 rotatable about the shaft 21 is attached thereto, and the toner supplied from the supply roller 7 is stirred and mixed by the stirring blade 11. As described later, a vibration component is applied to the toner sensor 10 while the rotating member 20 rubs the sensor detection surface 10a. On the bottom surface of the developing container 1 below the rotating member 20, a toner sensor 10 which detects the mixing ratio of the carrier and the toner as a change in magnetic permeability exposes the detection surface 10a on the bottom surface of the container and is flush with the bottom surface. And transmits the detection signal to an electric control circuit 50 having a built-in CPU. Then, the detection surface 10
A pair of bar-shaped permanent magnets 31 (for example, plastic magnets) are arranged on the bottom surface of the container 1 located on both sides of “a” in parallel with the opposite poles facing each other.

On the other hand, the rotating member 20 comprises a rotating shaft 21 and two kinds of different blade members 2 attached to the rotating shaft 21.
2, 23. That is, the first blade member 22 has a width smaller than the interval between the permanent magnets 31 and the sensor detection surface 1.
0a is formed of a flexible plate-like member having a length capable of rubbing, and the detecting surface 10a rubbing side has a two-layer structure of artificial leather 22a, and the back side thereof has a two-layer structure of silicon rubber 22b. The elastic force can be scraped off by the artificial leather 22a without affecting the detection accuracy.

The second blade 23 has a T-shaped cross section. The axial width of the second blade 23 is set to be larger than that of the permanent magnet 31 so that each blade does not contact the upper surface of the permanent magnet 31. It is formed of a hard non-magnetic plate-like member set to a short width, for example, and is formed of, for example, polycarbonate or ABS resin. Note that the axial length of the second blade 23 is set to the developing container 1.
The length may be set to be substantially equal to the width, and a stirring function may be provided. The developer used in this embodiment contains a large amount of magnetic powder.
Inorganic Yaria is constituted by a two Ingredient current image agent consisting of small toner having a relatively permeability compared to the carrier.

Therefore, according to this embodiment, after the developer to be detected on the detection surface magnetically held between the pair of parallel magnets 31 is forcibly scraped by the first blade 22, the second blade 23 As a result, since the other developer contained in the developing container 1 is forcibly supplied to the detection area, the vibration waveform L can be made large, and in particular, the first blade 22
As a result, the developer to be detected is forcibly scraped off every rotation of the rotating member 20, so that the peak value on the valley side, in other words, the toner concentration can take a large peak value on the Hi side,
As a result, the peak value on the valley side can be set larger than the toner density control range. In the above embodiment,
Since the waveform of the vibration component output from the toner sensor 10 is magnetically held in the fixed magnetic field by the pair of magnets 31, the developer entering the detection area is frictionally charged or holds air due to stirring or the like. Even in the case of the magnetic field, these magnetically contract due to the magnetic lines of force in the fixed magnetic field, so that sensor detection can always be performed with the magnetic field maintained at a predetermined density, and the magnetic field is substantially orthogonal to the magnetic field generated by the toner sensor. The direction of the magnetic field of the fixed magnetic field is set on a surface substantially orthogonal to the magnetic field generated by the toner sensor 10 by means such as disposing the pair of linear magnets in parallel on the Stable detection accuracy can be maintained without adversely affecting the accuracy.

FIG. 2A is a block diagram of a main part of an electric control circuit 50 having a built-in CPU mainly showing a circuit configuration of a toner supply control mechanism in the embodiment. FIG. 4 shows a toner sensor 10 when the central toner density is set by the rotating member 20 .
As shown, the vertical axis shows the toner density, and the upper part shows the toner density.
When the toner density is set to be low and the toner density is set to be high at the bottom, the peak value on the hill side substantially corresponds to the lower limit level of the toner density (not shown), and the peak value on the valley side becomes substantially lower than the upper limit level of the toner density (not shown). With the waveform component set and the amplitude maintained, the vibration waveform L from the sensor 10 is shifted up and down in response to the increase and decrease of the toner density. 52 is a reference voltage generating means corresponding to the reference toner density level;
A comparator 3 compares an analog signal corresponding to the vibration waveform with a reference voltage level and outputs an ON / OFF pulse signal. A counter 54 counts an ON pulse width of the pulse signal. A digital output Χ corresponding to the pulse width is output. 55 is a developing device connector detecting circuit for judging that the developing container 1 is not mounted or the developing device connector (not shown) is not connected when the digital output の is a continuous level Hi, and 56 is a digital output Χ Calculated value (Y) obtained by adding correction width A
Is a drive control circuit that outputs a control signal for controlling the drive of the toner replenishment motor based on the calculated value. 58 is a drive control circuit that outputs the control signal when the calculated value (Y) is at the level Hi. This is a toner empty detection circuit that determines that the toner on the toner container side is empty when Hi has continued for a predetermined time set by the timer 59.

Next, the state of each signal will be described with reference to the flow charts of FIGS. 3, 4 and 5. FIG. 3A shows a state where the toner concentration is low (the magnetic permeability is high).
In this case, since the valley-side peak value of the vibration component output from the toner sensor is set to be larger than the toner density control range, the vibration waveform L is compared with the reference level voltage S.
The width of the reference level voltage S at which the vibration waveform cuts off the peak side
Is the pulse width of the pulse waveform, and the reference level
The horizontal width of the voltage S is defined as an interval between adjacent pulse waveforms.
A digital output X can be obtained.

[0021] 該De digital output Χ is a ON / OFF pulse, the complement to Pasuru width of the digital output pulse X
The calculated value (Y) obtained by adding the positive width A becomes a Hi level signal, and continuous toner supply is performed. (Step 3) If the calculated value of the calculated value (Y) remains at the Hi level for the time set by the timer 59, the toner empty detection circuit 58 causes the toner container 12 (FIG. 1).
Is determined to be toner empty. (Step 5)

FIG. 3B shows a state in which the toner density is within the control range.
Since the set value of the correction width A is set so that the calculated value (Y) obtained by adding the width A becomes a digital pulse, intermittent toner supply similar to the related art is performed.
(Step 4)

(C) shows a state in which the toner density is high. In this case, since the digital output と is a LOW level signal, the calculated value (Y) is also a LOW level signal corresponding to this, and Supply is stopped. (Step 2)
Therefore, in the above control, the digital output Χ does not continuously become Hi in any case where the toner density is low to high. Therefore, when the digital output Χ is continuously Hi level, the developing device is not mounted or the developing device is not mounted. It can be easily determined by assuming that the dexterity connector is not connected. (Step 1)

Here, the transition of the toner density state of the developing device is described.
To explain, as shown in FIG. 4, the vertical axis represents the toner density.
The upper part has a lower toner density and the lower part has a higher toner density.
Then, control means connected to the subsequent stage of the toner density sensor
The vibration waveform L coming in the range (C)
Through the range (B) where the intermittent toner supply is performed
Changes to a lower range (A).

The oscillation waveform L and the constant voltage level S
Range where the toner concentration is high where toner supply is not required
(C) In the case, an L level analog output X is transmitted.
However, if toner supply is necessary (B), the toner density
From a high state to a low toner density state
To obtain a density detection output X having a longer pulse width. before this
In the intermittent supply mode, the output for density detection
When the pulse output Χ, the following adjacent pulse output X
The correction width A is set so as not to be affected.

Therefore, the pulse width of the pulse output Χ is complemented.
A pal having a width of the operation value (Y) obtained by adding the positive width A
The waveform gradually widens in the intermittent supply mode.
And the distance between adjacent pulse waveforms gradually decreases.
You. When the toner concentration falls within the low range (A),
A pulse waveform having a Y width is continuous with a subsequent pulse waveform.
Hi level analog output will be continuous,
Is supplied.

That is, as shown in FIG.
Other main body side detection circuit 6 connected to CPU with
When a connector is disconnected by applying a circuit voltage to the 0 side, an ON level pulse can be transmitted to the detection circuit side.

Next, the operation of this embodiment will be described with reference to FIG. When the digital output Χ is continuously Hi level,
It is determined that the developing device is not mounted or the developing device connector is not connected. (Step 1) If the digital output Χ is not continuously at the Hi level and the digital output で な い is not a pulse, the supply of toner is stopped because Y is LOW, and if the digital output の is a pulse, Y = X + A, and if Y is continuously Hi, toner is continuously supplied (step 3).

On the other hand, when Y is not continuously Hi, intermittent toner supply is performed (step 4). Then, in a state where continuous toner replenishment is performed (step 3), if the calculated value of the calculated value (Y) remains at the Hi level for the time set by the timer 59, the toner empty detection circuit 58 detects that the toner is empty. When it is determined (step 5), the operation stops.

[0030]

As described above, according to the present invention, it is possible to easily detect whether the developing container is not attached or the connector is not connected, while controlling the toner concentration using the existing toner sensor.
Further, according to the present invention, the vibration waveform from the sensor is generated by mechanical means, and when the waveform is varied, especially when the toner density is low, the waveform is varied. It enables accurate control of toner density. And so on.

[Brief description of the drawings]

FIG. 1 shows a schematic configuration around a developing device according to an embodiment of the present invention.

FIG. 2 is a control block diagram incorporated in the device.

FIG. 3 is an operation diagram illustrating the present invention in comparison with the related art.

FIG. 4 is a distribution diagram showing a toner density change in the embodiment shown in FIG.

FIG. 5 is a flowchart showing a control procedure of the embodiment shown in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Developing container 20 Rotating member 10 Toner sensor ( toner density sensor) 31 Permanent magnet

Continuation of the front page (56) References JP-A-63-214766 (JP, A) JP-A-60-164776 (JP, A) JP-A-3-120562 (JP, A) JP-A-2-15322 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 15/08

Claims (2)

(57) [Claims] A toner concentration sensor for detecting a toner concentration in a developer; and a control means connected to a subsequent stage.
Wherein the output of the toner density sensor is taken out as the vibration waveform, with the upper and lower peak values of the vibration waveform forms possible variation in the vertical direction according to the change of the toner concentration based on the constant voltage level, on the peak value before Symbol vibration waveform Is higher than the certain voltage level and toner supply is required.
If the toner concentration is low and the toner concentration is low, in the continuous supply mode, the upper peak value of the vibration waveform is lower than the constant voltage level.
Above the upper position and toner supply is required.
If the toner density than the continuous replenishment mode is high, is the toner replenishment in the intermittent supply mode, the peak on the vibration waveform
If the value is below the certain voltage level,
In the toner supply method in the developing system configured to stop supply, the vibration waveform is compared with the constant voltage level, and when toner supply is not necessary, an L-level analog output is sent out, When the supply is necessary, a density detection output in which the pulse width becomes longer as the toner density is increased from the high toner density state to the low toner density state is obtained, and the developing device is not mounted or the developing device connector is not connected. If
A calculation input detection step in which an Hi-level analog output is sent to the control means instead of the vibration waveform; and in the intermittent replenishment mode, when the density detection output is a pulse output Χ, a subsequent adjacent pulse output A calculation step of obtaining a calculation value (Y) obtained by adding the correction width A to the pulse width of the pulse output Χ so as not to be integrated with the pulse width of the pulse output Χ, based on a signal width of the calculation value (Y) in the calculation step. A toner replenishing step of replenishing the toner in the developing device with the toner. In the calculation input detecting step, the density detection output obtains a pulse oscillation waveform to detect the necessity of toner supply, and the analog output is Hi. By continuing at the level,
A method for replenishing toner in a developing system, comprising detecting that a developing device is not mounted or a developing device connector is not connected. 2. A toner empty detecting means for detecting that the toner of the mechanism for replenishing the toner to the developing device is empty when the toner replenishing operation continues for a predetermined time or more in the toner replenishing step. 2. The toner supply method in the developing system according to claim 1, wherein: