JPH03269463A - Toner concentration detector - Google Patents

Abstract

PURPOSE:To carry out toner concentration control with high-precision and high-sensitivity by sampling concentration data near the center of the ripple of a concentration detecting signal. CONSTITUTION:A two-component system developer is stirred with a constant period by a stirring means 22 provided inside a container 20. The toner concentration of the developer being stirred is detected by a toner concentration sensor 26. A signal corresponding to detected output is outputted from the sensor 26, and appears as the ripple corresponding to a stirring period by the stirring means 22. A certain point of a control part in the amplitude direction of the ripple is fetched as concentration detecting data. Or, a pulse plate 24 is provided on the stirring means 22, and a photointerruptor 25 is arranged by holding a notch 24a therebetween. Sampling timing is decided from the signal whose position is detected by this member, and the center of the amplitude of the ripple of the concentration detecting signal is decided. At this constitution, stable concentration data is always obtained, and the sampled point can be determined with the high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a toner density detection device used in a developing device of a multi-JF machine, and particularly to a two-component developer contained in a container. The present invention relates to a device equipped with an IWI↑ stage for stirring the developer at a constant cycle, and a toner:e4t*-senryor for detecting the toner concentration of the developer.

[Conventional technology]

In an image forming apparatus such as a copying machine, a developing device is provided to develop an electrostatic latent image on a photoreceptor. The developing device includes a developing container in which a developing sleeve and a 1NfT roller are housed, and a toner supply roller that supplies toner into the developing container. The toner density of this developing device is detected by a 1/1 density detection device, and when the I/toner density falls below a predetermined reference value,
Drives the toner replenishment roller until there is one toner in the ζ developer container.
, 1 (is to be paid.

Normally, a two-part developer consisting of a magnetic carrier and an abrasive developer is stored in the developer container, and this developer is stirred by the stirring +1-ra. 1↑11-ra has a spiral conveying blade member on its outer periphery, and each time the developer is conveyed in the width direction inside the container by the conveying blade member, , the developer becomes uniform in the width direction.

By the way, in the developing devices of recent copying machines, it is desirable to make the copying machines themselves smaller (1.2% more compact).This has created a great deal of restrictions on the structure of the developing devices. I am in a situation where I have to install a toner! boundary sensor near the stirring 1 cola. 1...)' - The concentration sensor is
In order to detect the concentration by detecting the magnetic material near the surface of the developer, if it is installed near the stirring 1↑I:I-ra as described in 11;I, the fluidity of the developer Q) is not constant. Variations in the detection signal! 1. Sign. That is, the detection signal of the toner concentration sensor is a pulsation (ripple) (No. 3) having a constant circumference 3U1 corresponding to a 1 JdT cycle.

In the conventional toner concentration detection device, the ripple (a) is removed by passing the detection signal from the toner concentration sensor through an integral 1ril path.

[Problem to be solved by the invention]

In conventional devices, ripples are removed by an integrating circuit, but it is difficult to completely remove them. Moreover, if the time constant of the integrating circuit is increased so that ripples can be removed, real-time control from detection No. 18 is not possible, and furthermore, the data becomes less accurate, resulting in CL7 error.

In order to eliminate the problem caused by passing through the integration path, it is conceivable to digitally sample the output signal of the I-ner concentration sensor (δ). Such a device is shown, for example, in Japanese Patent Application Laid-Open No. 62-2709112.
In the concentration detecting device disclosed in this publication, the detection signal is sampled at a time when the ripple peak value always exceeds i11, and the concentration is detected.

However, the peak odor of the ripple in the detection signal °C is due to the developer transport! It is greatly affected by the blade of 4, and furthermore, at the peak of the ripple, the influence of noise and redness is very large, making it difficult to obtain stable data. Can not.

An object of the present invention is to provide toner concentration detection H that can detect toner concentration with high precision and high sensitivity without being affected by ripples that occur every time the developer is stirred. There is one every four degrees.

[Means to solve the problem]

The concentration detection device according to the invention of claim (1) stirs the two-component developer contained in the container at a constant cycle. This device is used in a developing device equipped with a toner concentration sensor for detecting the toner concentration of the developer, and includes 13 output stages for concentration detection and 91 stages for nano 19 output.

The density detection signal output stage f outputs a density detection 1δ curve corresponding to the output of the toner density sensor. In addition, the front rudder and limp ring means are as follows: 11;
ripple of the signal output from the first output stage O) swinging force t
This is for limpling the central part of the developer in 11 cycles of agitation.

L-ner concentration detection kimono holder according to the invention of Todoroki Seiku Clause (2);
E, + 111 Similar developing device used in actual production" (
Yes, there is a concentration detection signal output means, a position detection phase section 44,
It is equipped with a rinsing means.

The density detection Lt'3 output stage detects toner density 1. t
It outputs a density detection ks number corresponding to the output of the 15-channel sensor. The position detection phase part +4 LL, 11 in the capacity 23
It is installed in the rRIT means installed at the +1st turn (11th turn), and is used to detect the rotation angle setting of the stirring stage. Further, the sampling means indicated as 0:1 is the position detection phase portion 1. (Depending on the position signal detected by the density detection unit 13, the central part of the ripple in the signal output from the output means is adjusted according to the fit↑cycle of the developer.)
It is for '4J sampling.

[Effect]

In the invention as claimed in claim (1), the two-component developer is subjected to HtfT at a constant period by means provided in the container. This stirring! The toner concentration of the developer indicated above is detected by a toner concentration sensor. A density detection signal corresponding to the detection output of the toner concentration sensor is output from the tenth density detection signal output stage, and this detection signal appears as a ripple corresponding to the stirring period of the stirring means. Soshi”ζ
, a point in the center of the ripple in the amplitude direction is taken in as concentration detection data.

Further, in the invention of claim (2), the stirring means is provided with a position detection portion (A is provided C) for detecting the rotational angular position of the stirring means.
Then, the sampling angle is determined from the signal whose position is detected by this member. 8; The position detection member 1 is installed so that the sampling timing determined by this member is, for example, the center of the ripple of concentration detection No. 15 in the amplitude direction. Therefore, each time the density data is simplified at the simplification timing determined by the position detection section (A), data of the ripple amplitude direction 1i+center portion is taken in.

In this way, in the inventions of claims 0) and (2), since data is sampled at the center of the ripple in the amplitude direction, it is less affected by the flow of the developer and the vibration of the stirring blade H. There were 11 l-J concentration data with good and stable concentration. Also, claim 1. In the invention of rj (2), the sampling timing is partially determined by the position detection member, so the accuracy is high.

Moreover, data sampling can be reliably performed at the center of the ripple in the amplitude direction.

〔Example〕

FIG. 1 shows a copying machine employing an lner concentration 1i detection device according to an embodiment of the present invention.

In FIG. 1, a document table 2 is fixed to the upper surface of the CI machine main body 1, and a document presser 3 is provided above the document 732 so as to be openable and closable.

On the right side of the main body of the copying machine 1 in the figure, a paper feed force center 4.5 is detachably attached. On the foreign side of the copying machine main body 1, there is installed an IJt♀ItI/Rey 6 that outputs 7 pages of duplicated paper.

Inside the main body of the reproducing machine, an exposure device 67 for reading originals is installed on the + side of C2.
This exposure device 7 is connected to the bottom of the tank from a light source, a mirror, an L lens 1, etc. Also,? J! 'j:a body■
At the center of the surface, an electrostatic fti (I) is formed on the surface.
Photoconductor 1'' person B is placed C. Photoconductor 1, 2nd, ) (between) i; 7i unit 7L9, developing unit 4F
'(1(1, rolling "jo" device 11, paper separating device?r1
2 and a cleaning station 1t5 are arranged in this order.

Paper feed force cera L4,5 and photoconductor driver l,8''!r8coJ,
,.

There is paper 4 and ii'j between the image forming section and the
A paper feed conveyance path 1d is provided for supplying paper. Also, between the image forming section and the 11 paper tray 6, there is a paper discharge conveyance path I5, and a fixing device for fixing the rolled image of the paper! 6
and JJF output IJ-ra 17 are arranged.

FIG. 2 is a diagram without showing details of the developing device 7Llo.

A developing container that constitutes the developing device 10! ii Within 20, there is absolutely no
A two-component developer consisting of a llner and a magnetic book developer is stored therein. Also, this current (!, 'h”2'+
A developing sleeve 21 facing the surface of the photosensitive drum H at a predetermined distance and a mj↑[T-ra 22 for stirring the developer in the container are provided in the developing sleeve 20. There is. On the side of the developing sleeve 21, there is provided a cutout 23 for regulating the height of the surface of the developing sleeve 21. As shown in FIG. And, a number of Fil' blades 4A 22 b are provided in a spiral shape on the outer periphery of the CI-Rasuke 22a.
and a pulse plate 2 fixed to the - end of the -1-ra shaft 22a.
It is composed of 4 and ζ. A notch 24a is formed in a part of the outer periphery of the pulse plate 24, and this notch 24a
sandwich, 1. The AIC printer adapter 25 is arranged in ). The output signal of the A1 interrupter 25 is
The amplitude of the ripple, which will be described later, is "11" at the center.

A toner concentration sensor 26 is provided on the outer wall of the developer container 20 at a position close to the agitation 1↑l'l-ra 2i.

In addition, a cartridge 27 containing Urakugawa toner is replaceably attached to both of the developing container 20.
There is. Then, toner car 11J engine 27 and developer container 23
A toner supply 1J-ra 28 for replenishing toner into the developer container 20 is arranged between the developer container 20 and the developer container 20 . Toner Replenishment [1-Ra 20 is driven and controlled by a toner replenishment motor (not shown) during each rotation.

On the side of the toner replenishment II-ra 28, a drawing scraper 29 for scraping off the toner is arranged.

As shown in FIG. 4, this copying machine has CI' (J, R
AM, I? OvM': M'Ikl'J consisting of j
A control unit 30 is provided with a controller. The control unit 30 includes an operation panel 31 on which keys are arranged for each part, and an interrupter 2 shown in FIG.
5 and a toner concentration detection unit 2333 including a toner concentration sensor 26 are connected to the control unit 30. tltitTt'l consisting of etc.
- a driver drive unit 34 and a controller for driving the toner motor)
-The motor drive unit 35 and other input/output units are connected.

The li'Il path diagram of the 1..J-1 concentration detection circuit 33 is not shown in FIG. Toner concentration detection circuit 33 No. 1, base 1 ℃ output 1111 path 36, ■--density sensor 26, rectangular wave shaping circuit 37, (Q phase comparison circuit 38, integration circuit 39
``Isu11g output con1L1-ru101ro40,''
It consists of power supply open circuit/+1 °C.

The reference signal output circuit 36 is a circuit for oscillating a sine wave and further shaping the sine wave oscillation output into a pulse signal together with a rectangular wave shaping circuit 37, and includes resistors R1 and R2, a second capacitor C3, and a pulse signal. C4 and two lil N1
and lJttransitive disjunction':x(IR)+i''if path E l. Also ■'i@I=1
Senri 26 has Nido f N2 as ITL, and the inductance changes in proportion to the toner concentration of the developer. This is for outputting a 111 pulse signal.

The rectangular wave shaping circuit 37 has 11;yn3 and 2l>'
i'〉'C, l and C2, I': X OI? It is composed of a circuit 112. Phase ratio V: I'Q path 3B
is composed of an IE x OR circuit 1.3 to which the outputs of the F, x OR circuit 111 and the same 2 are input. Take out the value + rt and directly t!Electricity 1 [°4
It is composed of a resistor R5 and a capacitor C5. Analog output ml-) I/l
The Ii path 40 is for controlling the oscillation output from the control unit 3() by 2l/1rJ-, and is connected to the resistor 1? 6
, Condens 7, and Da C O 11). Also, is the power supply open circuit 41? 1 to IA R4
and :1nd4tC5and・n1cho-no・-dai-o-
IZI) is composed of "ζ".

The waveforms of each part of the 1jil path C) shown in Fig. 5 are
The basic tP signal is output from the File path 36 shown in Figures 8 to GE.
At the output of the oscillation circuit section, 1q of the sinusoidal wave signal S1 as shown in FIG. 68 is applied. Then, °ζ, the waveform of each part when the developer is t(
O31 times 11EI and outputs S2 and S34 of C2 become 411. Therefore, 'C5 phase comparison 111 path 3 (
1's output S4 is always Ov. Also, for example, “J.
- When the concentration is 4.5%, the output 53' of the F, The phase is slightly shifted from the output S2 of No. 2 by T. I wanted to-ζ, phase comparison pil
At the output of line 30, there is a pulse signal S as shown in the figure.
/l' is obtained7). Furthermore, the toner density is 3. ()%
In this case, as shown in factor 1), first Cr”
l' than lz, x output signal S3° of OR circuit section 2
゛0) (17 The phase is largely shifted, and the output number of the addition comparator circuit 38, 2, is a pulse i,', S'j S4 with a wider cap than the single pulse signal qS/l'' shown in Fig. 6C. ” is 11
It will be done. As shown in C, 1: I, sum, (1''!, If the output of the comparator circuit 3H is shifted by the integral 1ii 1 path 3, it becomes the toner concentration) ・1st DC Voltage can be extracted.

At this time, as mentioned above, the developer is collected 11' at a constant cycle by the collector I:l-ra 22, and this 1v1
Toner concentration sensor 4 is located near 11'11-ra 22.
2C; is assigned, so the integral pIIF/839
The output is 8; 61st according to the 1st stirring 1↑ cycle? , as shown in the figure.)1. (The signal S5 has ripples.

Next, the movement 1M' by the control unit 30 of n5I is according to
explain.

When the main switch (not shown) is turned on, the number of copies is set to 1 in Step S1, and the agitation r and I-ra 22 of the developing device 10 are driven.
, 1 setting is performed. Next, in step S2, is the stirring 1↑ is the rotation of the roller 22 stable? i. 1↑
After the rotational speed of the rI-ra 22 is stabilized, the process moves to step S3. In step S3, the G-J'-density control routine is executed.

FIG. 70 shows a blue routine for controlling the density of step S3 (1..)-1.

This function first turns on step S4 and sets both the count value C1 for averaging processing and the 1st empty detection count value (C2). Next, in the second pump S5,
) From the A1 interacitor 25, it is determined whether or not the 13 bow was manually operated.

As mentioned above, the AI incretor 25 receives the 61st ?, which is the 1/1 density detection data. , as shown in Figure 6E, is positioned so that 13 degrees Celsius is output at the center of the hat. Therefore, as shown in Figure 6E, the timing P1, P2, ,...smell ζ,
The signal indicating that it is sampling timing is
The t section 30 is manually powered every cycle.

When the signal zero indicating the sample timing is input, the process moves from step S5 to step S6 (4). In step S fi, the data of the concentration detection signal at the swam timing is read, and the count (acI) is incremented. Next, in step S
In step 7, it is determined whether the count value CI has reached Nl. The NlO value is generally set to about "8". If the count value C1 is not t('C) in N1, the process returns to step S5 and reading of the concentration data at each sampling timing is repeated.
When CI becomes N1, the process moves to step S8.

In step S8, the plurality of density data obtained in step S6 are averaged using the same sampling number N1 to calculate density data. In step S8, in addition to this process, the force 1 non-1 straight C1 is also reduced.

Next, in step S9, the 1st concentration ('I'/D) is calculated based on the 31 degree data obtained in step S8.
I'll It, Ii to determine whether or not is greater than or equal to the basic value. If the concentration is less than the Hiiragi value, the process returns to the main routine of FIG. 7A from step S1). on the other hand,
If the 1-no'-concentration is less than or equal to the base concentration, step Sl
(Do you want to move to 1?). In step SIO, it is determined whether or not count 1 direct C2 is N2. If N2 is 8, the process moves to step Sll, and 1-ner extraction n - Rotate the roller 28 to replenish toner.Also, in this step S
At step 11, the count value C2 is incremented. Then, the process returns to step S5.

From then on, the same operation as above is repeated until the C1-.)'-concentration is the base tP! The toner concentration detection operation and the toner concentration control operation are repeatedly executed until the toner concentration reaches the value. 1. If the concentration exceeds the base tIt value, Y is determined in step S9.
It is judged as IES, and the process returns to the main routine (not shown in FIG. 7A).

-, execute the same predetermined number of 1-concentration control processes (
1) - If the gourd does not reach 90 times after the fire, in step 51 (), the count C2 is set to N2 (t), and in step 540 (multiple lines are executed. In step °54 (), the count ,
An empty display is displayed on the operation panel and the process returns to the main routine shown in FIG. 7A.

After executing the toner density control subroutine as described above, the process moves to step SI2. In step S12, a second rbee preparation operation is completed. When the preparation is completed, the process moves to step S13, and it is determined whether the print key has been pressed. If the print key has not been pressed, the process moves to step S14, and it is determined whether any other key has been pressed. If another key is pressed, the process moves to step S15, where a process corresponding to the pressed key is executed, and step S! Return to 3.

When the print key is pressed, the process moves from step S13 to step 31G. In step 31G, 717'
The usual 1-bit operation processing is interrupted. Even during the second bee operation process, the toner concentration detection operation and toner concentration control operation as shown in FIG. 7B are executed.

In this embodiment, sampling is performed at the center position of the ripple in the toner concentration control operation in the i-phase direction, and the toner concentration is partially detected. However, it is possible to obtain limbling data that is less affected by noise and developer ff1f↑, and it is possible to always obtain stable density data. Since there is no need to do this, it is possible to detect and control the l-concentration in Realta (J).

Furthermore, in this embodiment, since the sampling timing is determined by the pulse plate 24 and the photo ink club 25 fixed to the rilt↑1:1-ra 22, the sampling timing can be easily and reliably controlled with high precision.・You can decide on India.

[Other Examples]

(rl) In the embodiment described above, the pulse plate 24 was provided at one end of the agitation 1↑row 922 to determine the C sampling timing. The ripple period of the detection signal may be calculated from the second data, and the sampling timing may be determined according to the period obtained from this.

The control diagram in this case is shown in FIG.

Note that control steps other than the toner density control subroutine 11-
The chart is similar to that shown in FIG. 78.

In this embodiment, first step S20 is performed. Initial settings are made. In this initial setting, ζ is the callan I
- Set the values C1 and C2 to "()" and start the timer for calculating the sampling timing. Next, in step 521, the data of the concentration detection signal is sampled over a plurality of cycles at a period that is much longer than the sampling period of the above embodiment. Calculate circumference 1υ1. Zunawa t'), step 32
By obtaining the time data of the upper peak value and the time data of the lower peak value from the data obtained in step 1, and averaging these time data, the sampling timing can be determined at the center position of the ripple in the amplitude direction.

In step S23, it is determined whether or not the current time 1E is the sampling timing, based on the sampling timing and the timer color>*1 value set in step S22. When the sampling timing has come, the process moves from step S23 to step S24, and the subsequent operations are the same as those shown in FIG. 713 above. Zu2
(By step S25 and step 326 °ζ
IIi number of density data are obtained and averaged to calculate °ζ density data, and in step S27 it is determined whether the density is less than a certain basic value. Also step 3
In step S29 and step S29, the concentration control process is performed for a certain clear day, and if the base unit value is not reached even after performing the concentration control process for a certain period of time, the process proceeds to step S3 (1) to display an empty display. Then, the process moves to step S31 and the timer is turned off.After this process, the process returns to the main routine.

With this embodiment, the density data can be sampled at the center position of the ripple in the amplitude direction, and the same effect as in the previous embodiment can be obtained.

(1)) In the embodiment 01, the photo interrupter 2
The signal from 5 is at the center position of the ripple in the amplitude direction.
Although the position was set so that the output signal would be output at
It is also possible to determine the sampling timing by playing with the difference between the timing at which 1t) occurs and the timing at the center position of the ripple.

[Effects of the Invention] In Part 1, 1 of Claim 1), the concentration data is ``rimbling'' near the center of the ripple of concentration detection No. 15, so that it is not affected by the ripple. Stable concentration data can always be obtained without any problems, and control with high TA and high sensitivity is possible.

In addition, in the invention of claim (2), the H
Since the 1:゛ζζ non-ring timing is determined for the position detection member that has been placed, data at the center of the ripple can be sampled reliably and with high accuracy with a tight configuration.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional configuration diagram of a copying machine in which a 1-ner density detection device is adopted in an embodiment of the present invention, and FIG. !Kaizu, 703
The figure is a perspective view of the agitator 1↑[l-ra, Figure d is a control brick diagram of the above-mentioned copying machine on G, and Figure 5 is a 1-ner fFt, +, Y
Circuit diagram of the detection circuit, Figures 68 to 6 are 11; 1 Princess 1
Fig. 4 shows the signal waveforms of each part of Fδ in the same concentration detection.
Figures A and 70 show the control of the 111 aircraft) I+-CH, 1
Figure 8 is a control flowchart of a copying machine employing L+-/NOS=degree detection setting in another embodiment of the present invention. 10...Developing device, 22...I↑rl-ra, 24
...Pulse plate, 24a...J missing, 25...Metal interface, 26...Tono'-concentration sensor 4,
;(3...Toner concentration detection 1+l path.

Claims (2)

[Claims] (1) A toner concentration detection device for a developing device, which includes a stirring means for stirring a two-component developer contained in a container at a constant cycle, and a toner concentration sensor for detecting the toner concentration of the developer. a density detection signal output means for outputting a density detection signal according to the output of the toner density sensor; and a center part in the amplitude direction of the ripple of the signal output from the density detection signal output means is set to a stirring period of the developer. A toner concentration detection device comprising: a sampling means for sampling according to; and a toner concentration detection device. (2) A developing device that is rotatably provided in a container and includes a stirring means that stirs the two-component developer in the container at a constant cycle, and a toner concentration sensor that detects the toner concentration of the developer. The toner concentration detection device includes a position detection member provided on the stirring means and for detecting a rotational angular position of the stirring means, and a position signal detected by the position detection member to detect the concentration detection signal. A toner concentration detection device comprising: sampling means for sampling a center portion in the amplitude direction of a ripple of a signal output from the output means in accordance with a stirring cycle of the developer.