JPS58114061A - Concentration detector for developer - Google Patents

Abstract

PURPOSE:To detect toner concentration accurately by utilizing variation in the flowability of a developer with the toner concentration difference of the developer. CONSTITUTION:When the toner concentration of the developer 2 flowing in a flow passage 8 is low, there are many magnetic carriers, so the developer 2 is dry and has good flowability, so that the developer 2 never stays in the flow passage 8. Consequently, a buoyant plate 9 in the flow passage 8 is at a lower position as shown by a broken line and separated from a sensor 10. When, however, the toner concentration increases, the amount of toner increases, so the developer 2 deteriorates in flowability to stay gradually in the flow passage 8 and is restrained by a flow-rate restraint plate 11 to swell before it. The swell elevates the buoyant plate 9, which touches the sensor 10, thereby operating the sensor 10. Consequently, the toner concentration in the flow passage 8 is detected to know the toner concentration in a case 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cage for detecting the concentration of developer used in an electronic copying machine.

Conventionally, as a developer used in an electronic copying machine, a dry two-component developer, which is a mixture of a magnetic carrier and an F toner, has been used. As a method for detecting the toner concentration of such a developer, for example, 1! ! 2. A method of detecting using the aspect ratio of the inductance of the i-type carrier. 2. A method of developing a part of the photoreceptor and determining the reflection density on the surface. 3. A method of detecting the aspect ratio of the toner concentration of the developer. However, each of the above methods has the following drawbacks. That is, in method 1 above, the toner concentration can be detected well when the toner concentration is relatively low, such as 5% or less, but when the toner concentration is as high as about 10%, the inductance changes. Since the amount of voltage is exchanged using a resonant circuit, the amount of conversion is extremely small, making it difficult to accurately detect toner concentration. However, it has the disadvantage that it is greatly affected by changes in concentration and humidity, and is prone to errors.Furthermore, it has a disadvantage that the structure and electrical path are complicated and the cost is high.

In addition, in method 2 above, regardless of whether the filtered area on the photoreceptor is a solid black area or a halftone area, the influence of the 111% r characteristic of the developer, the edge effect, and the deterioration of the developer In addition, since it measures the anti-layer intensity, it is possible that the light-receiving area may be dirty due to toner scattering or that a shadow may be cast at a certain time. Therefore, it is necessary to clean the light receiving part, which makes the measurement work troublesome.Furthermore, the characteristics of the photoconductor affect Wl and power measurement, so it is difficult to detect the characteristics of the photoconductor. The downside was that it added an extra 7 actors that had to be added.

Historically, in method 3 above, the level of some or all of the developer is measured, but in reality, the container containing the developer is equipped with a developer stirring device and a conveying device. , the It toner flows within the container, making it unstable to accurately detect changes in toner density as changes in content, resulting in variations in toner concentration detection. This invention has solved all of the above-mentioned drawbacks, and its purpose is to reduce the flow of the developer due to the difference in toner concentration (change in toner concentration) of the developer. It is an object of the present invention to provide a developer concentration detection device which can detect excess toner concentration by utilizing the change in properties, has a simple structure, and can be manufactured at low cost.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below based on the drawings. FIG. 1 is a diagram showing a developing section of an electronic copying machine.
In this figure, reference numeral 1 indicates the case of the developing section. Inside this case 1, there is a magnetic rail 3 that adsorbs a developer 2 made of a mixture of magnetic carrier and toner on its surface, and a magnetic rail 3 that scrapes off the developer 2 from the surface of the magnetic rail 3 and removes the scraped developer. Concentration detection device 4 that detects the toner concentration of agent 2
A stirring plate 5 that stirs the developer 2 in the case 1 in the vertical direction, and an auger roll 6.6 that stirs the developer 2 in the horizontal direction are provided.

The magnetic seal 3 rotates in the direction of the arrow X, attracts the developer 2 to its surface by magnetic force, and applies the toner of the attracted developer 2 to a photoreceptor (not shown). . In this case, the developer 2 adsorbed to the magnetic roll 3 is
An adsorption amount regulation sla provided in the case 1 regulates that a certain amount is adsorbed onto the magnetic roll 3.

Further, the concentration detection device 4 detects the toner concentration by detecting the flow state of the developer 2 scraped off the surface of the magnetic roll 3. In other words, a guide member 7 is provided in the case 1 so as to be inclined diagonally downward from the top of the magnetic roll 3.

This guide tube, material 7, scrapes off the developer 2 deposited on the surface of the rjIi air roll 3 with a scraping portion 7a, and forms a flow path 8 through which the developer 2 that has been scraped off is guided and circulated. A buoyancy plate 9 is disposed within this flow path 8, which moves up and down depending on the fluidity of the developer 2. This buoyancy plate 9 has a plate shape with a light lid, and one end thereof extends diagonally above the flow path 8 and is attached to the upper part of the case 1 so as to be able to rotate once. A sensor 10 that is activated by the rise of this buoyancy plate 9 is arranged. As this sensor 10, an insulating piezo element, for example, is used. Furthermore, this seven-nin v-10
On the outflow side of the flow path 8, there is a groove that controls the wrinkles of the developer 2 in the flow path 8.
A current regulating plate 11 is arranged.

Note that the reference numeral 12 indicates toner replenishment [1] for replenishing toner into the case 1.

Next, a case will be described in which the toner concentration of the developer 2 in the developing section m is detected by the concentration detection device fli4 configured as described above. In this case, first, the developer 2 in the case 1 is stirred vertically and horizontally by the agitation plate 5 and the auger rule 6.6 provided at the lower part of the nurse 1, and the developer 2 is transferred to the magnetic roll. Adsorb it evenly onto the surface of 3.

The developer 2 adsorbed on the surface of the magnetic pole 3 in this way is
The toner of the developer 2 is conveyed in the direction of the arrow X as the magnetic roll 3 rotates, and after being regulated by the suction amount regulating part 1& such that a certain amount of the developer 2 is absorbed by the suction lid, the toner of the developer 2 is transferred to the photoreceptor (not shown). ) and sent to the concentration detection device 14 provided on the top of the magnetic roll 3. The ljt image agent 2 thus sent to the density detection device 4 is scraped off from the surface of the magnetic roll 3 by the scraping portion 7a of the guide S 7, and is passed through the flow path formed by the guide member 7. 8 and flows down to the lower part of the ladle case 1, but this flow path 8
Toner noodle skin of developer 2 is detected inside.

That is, when the toner concentration of the developer 2 flowing in the flow path 8 is low, there is a large amount of magnetic carrier, so the developer 2 becomes smooth, and the fluidity of the developer 2 is good, and the developer 2 flows in the flow path 8. Agent 2 does not accumulate. For this reason, the buoyancy plate 9 in the flow path 8 is located at a low level, as shown in broken lines in FIG. 2, and is spaced apart from the sensor 1°. On the other hand, when the toner concentration increases, the toner h increases, and the fluidity of the developer 2 deteriorates, gradually becoming thin particles in the flow path 8, and forming a flow cap as shown in FIG. It is regulated by the regulation plate 11 and rises in front of it. This swelling causes the buoyancy plate 9 to rise and contact the sensor 1o, thereby activating the sensor 1o. As a result, the toner concentration in the flow path 8 is detected, and in turn, the toner concentration in the case 1 can be known.

In this way the above # degree detection device! ! According to i4, the flow state of the developer 2 flowing in the flow path 8 is detected by the sensor 10 via the buoyancy plate 9, so the 111I
It is easy to construct and can be manufactured at low cost. In the above embodiment, a piezo element is used as the sensor 10, but the present invention is not limited to this.
For example, it may be a microswitch, a photosensor, or the like.

Further, in the above embodiment, a case has been described in which the density detection device 4 is provided in the developing section of the electronic copying machine, but the present invention is not limited to this, and it may be provided in the tallying section of the electronic copying machine. .

As explained above, the developer concentration detection device according to the present invention utilizes the vertical hole in the flow state of the developer due to the difference in toner concentration of the developer.
a channel for dropping the developer scraped off from the surface of the tile;
The toner concentration of the developer can be detected satisfactorily by simply incorporating a detection means for detecting the stagnation state of the developer flowing in this flow path, and the structure is simple and can be manufactured at low cost. There are some advantages to being able to do this.

[Brief explanation of the drawing]

FIG. 1 is a cutaway view showing a developing section of an electronic copying machine according to the present invention, and FIG. 2 is an enlarged sectional view of the main part thereof. 2...Developer, 3...Magnetic roll, 4
...Concentration product detection device, 7...Guiding member, 7a...Scraping portion, 8...Flow path,
10...-sensor. Patent applicant Casio Computer Co., Ltd. ID Co., Ltd. Figure 1 and Figure 2

Claims (1)

[Claims] The developer scraped off from the surface of the magnetic roll has a flow path through which it falls, and a detection means installed at a predetermined position in this flow path to detect the developer that has fallen into the flow path. Concentration detection device.