JPS61198025A - Toner remaining quantity detecting device - Google Patents

Abstract

PURPOSE:To detect quickly and exactly the remaining quantity of a toner by detecting a fact that an output of a piezoelectric vibrator is varied by whether the toner exists in a toner containing case or not. CONSTITUTION:In case when the inside of a toner containing case 1 is filled enough with a toner 5, pressure corresponding to the remaining quantity of the toner 5 is applied to a detecting surface 6 of a detecting part 3. Therefore, a mechanical vibration of the detecting surface is suppressed, an output of a piezoelectric porcelain vibrator based on a vibration suppression by the remaining quantity of the toner concerned is obtained in a detecting circuit which has been connected to the piezoelectric porcelain vibrator for vibrating the detecting surface 6, and not shown in the figure, and the remaining quantity of the toner can be detected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used to develop an electrostatic latent image in an electrophotographic copying machine such as a xerographic or electrofax type electrophotographic device and a facsimile device. The present invention relates to a developer toner replenishment device, and more particularly to a toner remaining amount detection device for detecting the presence or absence of a remaining amount of toner for replenishment.

L Prior Art] In general, in an electrophotographic copying machine that uses a so-called two-component developer consisting of toner and carrier, the concentration of toner in the developer is set to an optimal constant value in order to copy at a constant density. It is devised to keep it within, and usually,
The toner concentration control device controls toner replenishment from the toner replenishing device according to the toner concentration detection result, thereby keeping the toner degree a constant. In this case, if copying is performed while the toner in the toner replenishing device is empty, toner will not be replenished, making it impossible to maintain a constant toner density. For this reason, the toner replenishing device is configured to warn the operator when the remaining amount of toner in the toner storage box falls below a certain amount.

Conventionally, methods for detecting shallow depressions in toner in such toner replenishing devices include measuring the weight of the toner and detecting the change in weight as the toner is consumed, and using the dielectric constant of the toner to detect the amount of electricity that occurs as the toner is consumed. Detection was done by detecting changes. However, these methods had problems in terms of detection sensitivity, stability, and reliability, and in recent years a method for detecting the remaining amount of toner using a piezoelectric ceramic vibrator has been proposed (Japanese Patent Application Laid-Open No. 56-1991). -43513, etc.) has been put into practical use.

FIG. 4 shows a schematic configuration of an apparatus for detecting the remaining amount of toner using the piezoelectric ceramic vibrator. In the figure, 1 is a toner storage box, and a toner transport roller 2 is provided at the bottom of the toner storage box 1 to transport the toner stored inside to a developer tank (not shown) or the like. . Further, the detection section 3 of the remaining toner amount detection device is attached to the wall surface 4 of the toner storage box. In the toner remaining amount detection device having such a configuration, when there is a sufficient amount of toner 5 in the toner storage box 1, the detection unit 3
When the detection surface 6, which is a diaphragm driven by a piezoelectric vibrator, is in contact with toner, the toner limits the imaging of the diaphragm, or in other words, the vibration of the piezoelectric vibrator. On the other hand, when the toner in the toner storage box runs out and the toner no longer comes into contact with the detection surface 6, the pressure-N porcelain vibrator vibrates without being suppressed by the toner. Therefore, the presence or absence of toner in the toner storage box can be known by detecting a change in output due to a change in the amount of vibration of the piezoelectric ceramic vibrator. This system has the advantage of being able to detect changes in the amount of remaining toner with high sensitivity and promptly notify the operator by giving a warning and display, although it has a relatively simple configuration.

[Problems to be Solved by the Invention] For this reason, the inventors of the present application incorporated the remaining toner amount detection device with the above configuration into an electronic copying machine and conducted experimental studies, but found that images with a constant density were not always obtained. When we investigated the cause of the problem, we found that it was caused by a malfunction or operation of the remaining toner amount detection device configured as described above. That is, the toner has poor fluidity and stronger adhesion when the temperature is high and humid compared to when the toner is low temperature and low humidity. Therefore, as shown by curve A in FIG. 4, at normal temperature and humidity, the toner decreases without adhering to or depositing on the inner wall of the toner storage box 1 or the detection surface of the remaining toner amount detection unit 3, but at high temperature and humidity, the toner decreases. As shown by the broken line B in Figure 4, even though there is only a small amount of toner remaining in the toner storage box, toner adheres to and accumulates on the inner wall and detection surface, causing the detection surface to appear as if the toner is not toner. It was discovered that the device malfunctions because vibrations are suppressed as if it were inside a storage box.

Therefore, it is an object of the present invention to provide a residual toner detection device that can quickly and accurately detect the amount of remaining toner in environments ranging from low temperature and low humidity to high temperature and high humidity in which electrophotographic copying machines are normally used. purpose.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a toner storage box in which toner is stored, a support attached to the wall surface of the toner storage box, and a and a toner remaining amount detection section supported and disposed at a predetermined spatial position where toner is stored in the toner storage box, and a piezoelectric ceramic vibrator or The present invention is characterized in that the remaining amount of toner is detected by detecting a change in the output of the magnetostrictive vibrator.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a perspective view showing a schematic configuration of a remaining toner amount detecting device of the present invention, and FIG. 2 is a partially sectional view illustrating its operation. In the figure, 1 is a toner storage box, and a toner conveying roller 2 is provided at the bottom of the box. The support body 7 is fixed and attached to the wall surface of the toner storage box by known means such as screws.

This support body 7 is provided with an arm portion 8 that projects into the toner storage box.

A remaining toner amount detection section 3 is attached to approximately the tip of this arm portion, and is disposed at a predetermined spatial position within the toner storage box.

In the toner remaining amount detecting device of the present invention having such a configuration, when the toner storage box 1 is sufficiently filled with toner 5, the detection surface 6 of the detecting section 3 displays a signal corresponding to the remaining amount of toner. Because the pressure is applied, the mechanical vibration of the sensing surface is suppressed, and the sensing circuit (not shown) connected to the piezoelectric ceramic vibrator that vibrates the sensing surface is activated by the toner remaining amount. The output of the piezoelectric ceramic vibrator based on the suppression can be obtained, and the presence of toner can be detected. On the other hand, toner 4
When the amount of toner decreases and there is no toner in the toner storage box, for example, at room temperature and humidity, the toner disappears as shown by the solid line A in Figure 2, and at high temperature and high humidity, due to poor fluidity, the toner remains on the wall of the toner storage box. The particles adhere to each other and disappear in a state as shown by the broken line B in FIG.

At this time, since the detection unit of the present invention is disposed at a predetermined spatial position within the toner storage box, the toner comes into contact with the detection surface in both normal temperature and humidity conditions and high temperature and high humidity. Since vibrations are not suppressed, the absence of toner can be detected without malfunction.

In the toner detecting device of the present invention having the above configuration, since the detecting section is disposed protrudingly inside the toner storage box, toner is likely to accumulate and adhere to the detecting section and the support. It is preferable to use an arcuate surface or the like to prevent toner from accumulating or adhering. Furthermore, the smaller the volume of these members as possible, the less influence they have on the flow of toner within the toner storage box. Therefore, the arm part of the support (the part that protrudes into the toner storage box and has a part for mounting the detection part) has an oval cross-sectional shape (including a rectangle with an arcuate upper and lower surface) or a perfect circle. It is preferable that the long axis direction thereof be arranged in a direction that substantially coincides with the direction in which the toner decreases.

Further, in the present invention, the detection surface of the detection section, that is, the vibration surface, is usually formed in a substantially flat shape, but the accumulation and adhesion of toner on this detection surface causes malfunction. For this reason, it is possible to install the detection surface facing downward, but in that case, due to the presence of the detection section and the support, toner remains on the detection surface even though the toner remains in the toner storage box. In order to prevent a situation in which the toner does not come into contact with the toner, the detection surface may be installed at an angle αS larger than the toner safety angle α, as shown in FIG. 3(a), for example. preferable. Further, when the sensing surface is disposed upward, there is no problem with the contact between the sensing surface and the toner, but there is a problem with toner accumulation and adhesion. However, even in this case, by setting the angle of installation of the detection surface larger than the angle of repose of the toner, as shown in FIG.
Problems caused by toner accumulation and adhesion are almost eliminated.

Furthermore, in the present invention, it is preferable that the sensing surface be installed as far from the wall surface as possible. Further, if the toner is installed as close as possible to the upper part of the toner conveying roller, the toner will flow and will not stagnate, so that a preferable result can be obtained.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

As shown in FIGS. 1 and 2, it has a toner delivery roll 2 with an outer diameter of 3 CIIl, a width of 30 cm, and a height of 15 cm.
A toner storage box 1 having an internal capacity of about 2000 cc was manufactured.

Approximately at the center of the wall width direction of this toner storage box, there is a
A support 7 having an arm portion with a circular cross section and a length of 5 mm was fixed with screws. At this time, the center position of the detection surface attached to the support was set at a height of about 2 cm from the top surface of the toner delivery roller. Incidentally, for the detecting section and the like, a known structure using a piezoelectric ceramic vibrator (see, for example, Japanese Patent Publication No. 1371/1983) was used.

Further, the detection surface was placed upward at an angle of approximately 80 degrees with respect to the horizontal surface. The detection device with the above configuration was installed in an electrophotographic copying machine, and an environmental test was conducted at a temperature of 10°C.

When copying tests were conducted under environmental conditions ranging from 20% humidity to 50° C. and 80% humidity, the remaining amount of toner could be detected without malfunction.

[Effects of the Invention] As described above, the present invention has an advantage in that the remaining amount of toner can be reliably detected even in high temperature and high humidity, although the structure is relatively simple.

In addition, there is no need to use expensive equipment such as moisture proofers,
There is an advantage that an electrophotographic copying machine having an inexpensive and simple configuration can be realized.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a toner residue detection device according to the present invention, Fig. 2 is a sectional view of the main part thereof, Fig. 3 is an explanatory diagram of the mounting angle of the detection surface in the present invention, and Fig. 4 is a conventional one. FIG. 2 is a sectional view of a main part of the toner remaining amount device of FIG. 1: Toner storage box, 2: Toner transport roller, 3: Detection unit, 4: Wall surface, 5: Toner, 6: Detection surface, 7: Support body,
8: Arm part. compilation/times

Claims (1)

[Scope of Claims] 1. A detection section using a piezoelectric ceramic vibrator or a magnetostrictive vibrator, a toner storage box in which toner is stored, and one end attached to the wall of the toner storage box and the detection section on the other end. is disposed and has a support for supporting the detection unit at a predetermined spatial position inside the toner storage box, and detects the amount of remaining toner by changing the output of the piezoelectric vibrator or magnetostrictive vibrator depending on the presence or absence of toner in the toner storage box. A toner remaining amount detection device for an electrophotographic copying machine, which is characterized by detecting. 2. The remaining toner amount detecting device for an electrophotographic copying machine according to claim 1, wherein the vibrating surface of the detecting section is arranged at an angle greater than the angle of repose of the toner. 3. An electrophotographic copying machine according to claim 1 or 2, wherein the arm portion of the support body protruding into the toner storage container has a circular or oval cross-sectional shape. Toner remaining amount detection device.