JPS58108450A - Detector for concentration of developing agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer concentration detection device for detecting the density f of a developer, which is a mixed powder of magnetic carrier and toner used in an electronic copying machine.

Generally, in electronic copying machines that use this type of developer, the developer is used at a concentration such that the amount of toner is about 3 to 5 qb relative to the carrier at a weight ratio of ¥r%. Amount used as toner image during 1. It is a trap that automatically replenishes by detecting the concentration of the current health agent.

This basic concentration detection device is designed to detect changes in the magnetic resistance of the developer when detecting changes in developer concentration (weight ratio), and can easily be detected at concentrations of 5- or less. It is possible to replenish toner with high precision.

However, by increasing the developer concentration, e.g.
When it reaches approximately 'j, it is extremely difficult to detect a concentration change in the vicinity because the ratio of magnetic resistance to the ratio of concentration change is almost negligible.

By the way, in the case where a ferrite carrier with high electric resistance is used as the IAg # agent, the amount of charge of the toner is high, and therefore it is difficult to separate it from the carrier, so by increasing the at by that amount, By making it easier to separate the carrier from the electrostatic latent image on the photosensitive layer, it is possible to obtain a high-quality image, and furthermore, it is possible to prevent the carrier from adhering to the electrostatic latent image that occurs at low concentrations. This has the advantage that it can also be prevented. Therefore, there is a need for a density detection device that is capable of detecting developer density at high concentrations.

This invention was made in consideration of the above-mentioned circumstances.1. The purpose of this is to develop a developer concentration detection device fI1 with a simple configuration that is capable of detecting density changes even at particularly high concentrations of around 10%. T-provided.

Hereinafter, this invention will be specifically described based on embodiments shown in the drawings. First, a developing device of a dry type electronic copying machine will be schematically explained with reference to FIG. Case 1 of this developing device
Inside, a magnet roller 2 that rotates clockwise is disposed, and 4t-ml of the present inert agent is deposited on a non-magnetic sleeve 3 formed around the outer periphery of the roller 2. The hair is styled by section 6, and the magnetic brush section 6
form.

The surface of the magnetic brush portion 60 is brought into contact with the surface of the photosensitive layer of the photosensitive drum 7 which is rotating one clockwise direction to carry out the current gIt. The developer 4 used for development is transferred to the sleeve 3
By the clockwise rotation of the stirring roller 10 having the blades 9 scraped off by the scraping plate 8 whose tip is close to the scraping plate 8, the developer 4t is stirred and the magnetic brush section is newly placed on the sleeve 3. This results in the formation of 6 tubes.

In addition, the case 1 is formed with a delivery port 12 for detecting the concentration WIL of the developer and replenishing the developer tube to the actuator 11, and the am agent after detection is also discharged from the reactor 11. An introduction port 13 for returning the tube is formed, and a toner supply port 14 for replenishing the toner tube inside the case 2 is further formed.

Next, let's look at the configuration of reactor 11! l! This will be explained with reference to Figure 2 and Figure 3. The after-sale 11 includes a cylindrical body 1s having a rectangular cross section formed of an insulator such as a resin material, a coil 16 wound around the outer circumference of the cylindrical body 15 a predetermined number of times, and a coil 1s that straddles the coil 16. It is attached to the cylindrical body 18 as shown in FIG. The upper and lower sides of the magnetic sty are formed to have the same diameter as the outer diameter of the cylindrical body 15, and insertion openings 17&b17 for inserting the cylindrical body lit.
b are formed respectively. Then, the upper end of the cylinder 15 is inserted into the insertion rod 17 so as to slightly protrude from the upper surface of the magnetic path 17.
The aIC is inserted, and the lower end of the cylindrical body 1s is pushed through the insertion hole 17bK so that it slightly protrudes from the lower surface of the magnetic path 17.

By attaching the cylindrical 1sK magnet @17 like this, L
At the upper and lower ends of the cylinder IS, a part of the magnetic path 17 extends from the entire outer peripheral surface of the cylinder 15 in a brim shape. Note that the lead wires 18m and 18b drawn out from the coil 16
A predetermined alternating current voltage is applied to.

FIG. 113 shows a longitudinal cross-sectional view of the reactor 11.

The cylindrical body 15 is filled with developer 19, which is a mixed powder of F:c% magnetic carrier and toner.

Incidentally, the reference numeral 20 is formed by the magnetic powder of the developer 19.
7 is a magnetic path.

Next, the operation of the reactor 11 constructed as described above will be explained. Coil 16 lead - 111m, 18
bK When a predetermined AC voltage is applied.

A magnetic field is generated by the electric current flowing through the fill 16, and a magnetic path 20 is formed by the magnetic powder of the developer 19.ns 1 m path 20
The flux Kmt'L flows through the magnetic powder of the developer 19 and the magnetic path 17, and a magnetic circuit is formed by the coil 16. That is, since the upper and lower ends of the cylinder 15 are attached to the external magnetic path 17, the magnetic flux flowing in the magnetic path 20 inside the cylinder 1B flows in the axial direction of the cylinder 15, and
'A part of the magnetic path 17 is attached to the upper and lower ends of the cylinder 1s so as to extend from the entire outer circumferential surface of the cylinder 1g in a brim shape. occurs uniformly throughout the interior of the cylindrical body 15, that is, on all sides. Furthermore, since the magnetic resistance of the electric iron plate forming the external magnetic path 17 is low and constant, the lines of magnetic force generated from the magnetic field of the magnetic path 20 pass through the magnetic path 17\r via the magnetic path 20, and as a result, the magnetic A circuit is formed. The magnetic lines of force interlink with the coil 16, generate a back electromotive force, and cause the generation and change of self-inductance in the coil 160, which limits the electric current flowing into the coil 16. And coil 1:
111: The change in reactance due to the change in inductance in #16 is larger when there is more magnetic flux generated by the magnetic field, and smaller when #1 has less magnetic flux. In other words, the number of lines of magnetic force generated varies depending on the amount of magnetic powder in the developer 19 contained in the cylinder IS. That is, the reactance changes depending on the toner concentration of the developer 19.

Therefore, if the concentration of the developer 19 decreases, the amount of magnetic powder inside the cylinder 15 increases and the reactance increases, and conversely, if 1IIf increases, the amount of magnetic powder inside the cylinder 15 decreases.

Reactance decreases. Therefore, by detecting the change in reactance, amplifying the detection signal, and activating the toner supply S* that replenishes the toner tube to the toner storage device,
The concentration of the developer can always be kept constant. t
In addition, the magnetic path 20 inside the cylinder 15 is generated uniformly throughout the interior of the cylinder 15, and the generated magnetic flux can be significantly increased, so that even minute changes in the concentration of the high am developer can be detected. That's what happens.

Other embodiments of the invention Figure 4 and Figure 5 1
See and explain right.

In addition, in FIG. 4 and W45, parts Fi having the same configuration as those shown in FIGS. 2 and 3 are indicated with the same reference numerals.
I will omit that explanation.

In this *m example, the magnetic path 17 is provided with
An opening 17m'*17b that is the same size as the inner circumference of the opening of the cylinder 15
' are formed respectively, and the magnetic path 17 has openings 17' and 17b' formed in the magnetic path 17 so as to sandwich the cylinder 15 at the upper and lower sides of the U-shape. The opening 1 of the magnetic path 17 is attached to the cylindrical body 15 such that the inner surface of the opening 1 of the magnetic path 17 is flush with the inner surface of the opening of the cylindrical body 15.
Attach the cylinder 15Q so as not to insert it into the opening of the cylinder 15 and the opening 17aζ17 of the magnetic path 17.
The configuration is such that b' and t are coupled. In this implementation configured in this way, the above-mentioned A2
Since the magnetic resistance due to the thickness of the cylindrical body 15 is reduced compared to the embodiment shown in the figure, it becomes easier to detect the amount of change in concentration.

Next, other embodiments of this invention are shown in Figures 6 to 6.
The reactor 21 in one embodiment described with reference to 191iNl has some coils 23, -24 on the outer periphery of the cylinder 22.
T-Wrap it extensively, and then install Kl so that it straddles the coil 28Yr.
The magnetic path 26 is attached to the cylinder body 22 so as to straddle the magnetic path 24. That is, a pair of coils 23.24 and a magnetic path 2s%2
The magnetic path 25% 26 is made by laminating a plurality of thin U-shaped iron plates T, and the magnetic path 2
5.26Fi, the cylinder 2 is placed on the upper and lower sides of the letter
Insertion port same size as outside diameter of 2 251% 25bb 26t%
A predetermined AC voltage is applied to the leads JI27m, 27b, 28m, and 28bK pulled out from the coils 23 and 24. .

FIG. 7 shows a cross-sectional view of the reactor 21, in which the cylinder body 21 is filled with #i% developer 29.

Inside the cylinder 21, magnetic paths 30 and $1 are formed by the magnetic powder of the developer 29, corresponding to the coils 25 and 211, respectively.

The aS diagram shows 11jl for detecting the concentration of the developer 29.
t indicates, person 11111 child 32.33fiJljKa,
An alternating pressure V was applied for 6t. The input terminal 32 is connected to the negative terminals of the coils ZaO-@ and Meio P34, respectively, and the input terminal 33 is connected to one of the coils 24.
1Th and the negative electrode side of diode P35 are connected.

A capacitor 36 is connected in series to the other end of the coil 2110. Further, a capacitor 37 is connected between the other end of the capacitor 36, the positive electrode side of the diode 34, and the O terminal, and a resistor 38 is connected in parallel to the 1-channel connector 37. First, there is a capacitor between the other end of the coil 24 and the positive electrode side of the diode 3s. 39 is connected, and a resistor pc4G is connected in parallel to the capacitor 39. Furthermore, Mayo P340j
The lE pole side is connected to the output terminal tlK, and the positive pole side of the diode 35 is connected to the output terminal 42.

Next, the operation of the eighth example of the vagina will be explained.

By applying a predetermined AC voltage between the coils 17a and 27b of the coil 23, a magnetic field 2BK is generated in the coil, and a magnetic path 30 is formed through the IAII agent 290a powder, and together with the magnetic path 2s, ; A dedicated magnetic circuit for the coil 23 is formed. In the case of jin, since the applied voltage is alternating current, the magnetic field is also an alternating magnetic field, and the magnetic field is alternating current 10 magnetic force ll.
When l0 flows, this change in magnetic force lIO causes fill 2
8, a back electromotive force is generated. The magnitude of this back electromotive force is related to the amount of developer 290 magnetic powder KWIj, for example, the amount of magnetic powder is large or small, and the back electromotive force also increases9.
The lowered concentration is inversely proportional to the concentration of the developer 29. In other words, the reactance of the coil 23 changes depending on the change in the concentration of the developer 29. Similarly, the lead of coil 24 @
28h, 2mbK AC pressure is applied;
A magnetic circuit is formed by the magnetic path 31.26 and k corresponding to the IC, and the change in actance of the coil 24 is ll1gII agent 2.
It changes depending on the dark fK of 9.

Therefore, by capturing changes in the reactance of both coils 23 and 24 and detecting the difference between the two, it becomes possible to detect even minute changes in the concentration of the developer 29.

That is, the me agent 29 at a predetermined concentration is housed in the cylinder 22 and the medicinal agent 29 is placed in a light state! If the capacitance of the capacitor 36 connected in series is larger than the reactance of the coil 23, the series circuit of the coil 2B and the capacitor 36 presents a capacitive circuit as a whole. After that, ;il2aO
The sum of the shared voltage and the shared voltage of the capacitor 36t)@phase is the applied voltage V. As a result, as the reactance of the coil 23 increases (due to a decrease in the concentration of the developer 29), the difference in capacitance of the capacitor 36 becomes small. The voltage v■ decreases. On the other hand, since the reactance of the coil 24 is inversely proportional to the change in the concentration of the developer 29,
The voltage V applied to the coil 24 is as shown in FIG. Hitoshi K.

The AC voltage v1 applied to the input terminals 32 and 33 is distributed to voltages V, , V, respectively. Therefore, the 9th I
As shown in IK, if there is a decrease of 11 degrees with respect to the set concentration position 5, the voltage V applied to the series circuit of the coil 23 and the capacitor 36 decreases, and furthermore, the voltage V applied to the coil 24 decreases. Since the difference between the two increases as a large change, even a minute change in density in the high-density developer 29 can be detected. In this way, 1 cylinder 2
By winding a pair of coils 3 and 24 around the coil 2 and forming magnetic paths dedicated to each coil 28°240, the detection ability can be further improved.

However, the present invention is not limited to the above embodiments, and can be applied in various ways without departing from the scope of the present invention.

As described in detail above, the present invention provides a concentration detection device 1 for a developer, which is a mixed powder of magnetic carrier and toner used in an electronic copying machine, which includes a cylindrical body containing the developer, and a cylindrical body containing the developer. A coil wound around the outer 1I11 part of the body, and a magnetic path arranged so as to straddle this coil, and a part of which extends in a flange-like manner from the outside open area of the cylindrical body. Since the magnetic circuit formed by the coil is formed via the 3j1gII agent and the magnetic path in the cylinder, the magnetic path formed by the developer in the cylinder covers the entire interior of the cylinder. Since the magnetic flux is generated and the magnetic flux can be significantly increased, even minute changes in high-density developer can be detected. “

[Brief explanation of the drawing]

Figures 1 to Is3 show an embodiment of the present invention, and the irises I
Schematic configuration of developing device from 11 companies, ZWJa developer concentration detection sensor p-otH4 figure, Tuna 3 figure beam actor
Fig. 4 and Fig. 5 show other embodiments of Jin's invention, Fig. 4 is a perspective view of the actor, aSS is a longitudinal sectional view of the reactor, and Figs. 6 to 9 are Still another embodiment of the present invention is shown, and FIG. 6 is a perspective view of the reactor.
The figure is a vertical cross-sectional view of the actor, and the 1s8 figure is a configuration diagram of the detection circuit. #! FIG. 9 is a characteristic diagram showing the ability to detect the concentration of developer. 11.21...--Reactor, 15.22...
・・Cylinder body, insertion port, l 7 a', 17 b'---
--Opening. Patent applicant: Casio Computer Co., Ltd.
D Co., Ltd. Figure 1 Figure 2 Figure 1 Figure 3 Figure 4 Figure I Figure 5 Figure 6 Figure 7 Figure 8 Figure υ

Claims (4)

[Claims] (1) In an apparatus for detecting the concentration of a developer, which is a mixed powder of magnetic carrier and toner used in an electronic copying machine, there is a cylinder body containing the developer, and a winding vt'' on the outer part of the cylinder body.
: Arranged to straddle the 5th coil and the jin coil,
and a magnetic path installed so that a part thereof extends in a brim shape from the entire predetermined outer periphery of the cylindrical body, and the magnetic aCt by the coil is formed via the in-vivo image agent and the magnetic path. tFeatured developer concentration detection device. (2) Claim I! In the description of Article 1 of the IK image, an insertion port tube through which the cylindrical body is inserted is formed in a part of the magnetic path, and the magnetic path is attached to the cylindrical body through this insertion port. Agent concentration detection device. (3) In the statement of claim 11@paragraph 1, an opening having the same size as the inner periphery of the integral frontage is formed in a part of the magnetic path, and the inner surface of the cylindrical body opening and the magnetic A developer concentration detecting device characterized in that the passage is attached to the cylindrical body so that the passage is flush with the inner surface of the opening of the passage. (4) In the description of claim 1PJ paragraph 1 above. ias characterized in that a plurality of the coils are wound around the cylindrical body with a predetermined distance between them, and a dedicated magnetic circuit corresponding to each of the coils is formed through the developer and the magnetic path in the cylindrical body. Agent concentration detection device.