JPH0544832Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a developing device for a copying machine equipped with a stirring member for accurately detecting the remaining amount of developer.

[Conventional technology]

In a copying machine, the amount of developer decreases during development processing, so it is necessary to detect the remaining amount of developer and replenish the developer. As a means for detecting the remaining amount of developer, a method is known in which a remaining amount detecting element such as a piezoelectric element is disposed within the developing device.

In a developing device that uses such a remaining amount detection element, if developer adheres to the detection surface of the remaining amount detection element, the state of the remaining amount of developer cannot be accurately detected, and the remaining amount detection may not be performed properly. It disappears.

In order to prevent such malfunctions due to developer adhering to the detection surface of the remaining amount detection element, a detection method has been conventionally disclosed in Japanese Utility Model Application No. 57-190557 or No. 57-167362. It is known to provide a stirring member for cleaning the surface.

This is to remove developer adhering to the remaining amount detection element by rubbing the detection surface with a stirring member.

[Problem that the invention attempts to solve]

As the remaining amount detection element, for example, there is one that uses a piezoelectric element and detects the remaining amount using vibration of the detection surface. This is done by applying vibration to the piezoelectric element, and when there is a large amount of developer in the developing device, the vibration of the piezoelectric element is suppressed by the pressure of the developer, and when there is no more developer, the piezoelectric element can vibrate freely. The presence or absence of developer is detected by detecting the vibration state of the piezoelectric element.

When using such a remaining amount detection element that utilizes the vibration of the sensing surface, in the conventional example described above, the stirring member rubs and cleans the sensing surface, so the vibration state of the sensing surface is determined by the contact pressure of the stirring member. There was a problem in that the remaining amount detection element malfunctioned due to the change in the amount of fuel. In other words, there was a problem in that the presence of developer was detected due to the pressure of the stirring member even though there was no developer.

The present invention was devised to eliminate the above-mentioned drawbacks, and its purpose is to block the developer attached to the detection surface and the area around the detection surface without changing the pressure applied to the detection surface of the remaining amount detection element. The purpose of the present invention is to provide a developing device that does not malfunction by removing the residual developer and reliably detecting the pressure due to the remaining amount of the developer.

[Means for solving problems]

In order to achieve the above object, the developing device for a copying machine of the present invention is provided with a remaining amount detecting element for detecting the remaining amount of developer in the developer storage section, and is provided with a non-contact and close proximity to the remaining amount detecting element. In the developing device of a copying machine, the developing device is provided with a stirring member that moves at a fixed position to prevent blocking of the developer; A biasing means for pressing the stirring member against the spacing member is provided, and the stirring member moves while maintaining a constant distance between the stirring member and the detection surface to prevent blocking of the developer. do.

In order to reliably detect the pressure due to the remaining amount of developer and to prevent malfunction, the gap between the detection surface of the remaining amount detection element and the stirring member should be 0.1 mm or more and 1.0 mm or less. desirable.

Further, as the stirring member, a thin plate-like body or a thin rod-like body can be used.

[Effect]

In the present invention, the stirring member moves in a plane parallel to the sensing surface of the remaining amount sensing element at a position close to but not in contact with the sensing surface of the remaining amount sensing element. Therefore, although the agitating member prevents developer from blocking, since the agitating member does not directly contact the remaining amount detecting element, pressure due to movement of the agitating member is not applied to the remaining amount detecting element. Therefore,
The remaining amount detection element does not misidentify the pressure from the stirring member as the pressure of the developer and incorrectly detects the remaining amount.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 2 shows a side cross-sectional view of the developing device according to the embodiment of the present invention.
is located.

The developer 4 is stored in a developer supply member 5 in the form of a cartridge, and by attaching the developer supply member 5 to the developing machine main body 1, the developer 4 is supplied to the developer storage section 6. and the same storage section 6
contained within. The developer 4 is conveyed in the direction of the developing roll 3 within the developer storage section 6 by a conveying member 7 that rotates in the direction of the arrow. And developer 4
is formed in a thin layer on the developing roll 3 by the regulating member 8. The thinned developer 4 is conveyed to the developing section 9 by the developing roll 3, and visualizes the electrostatic latent image on the photoreceptor 2.

A pressure-sensitive remaining amount detecting element 10 is arranged at a predetermined position of the developing machine main body 1, and the developer 4 is
As the remaining amount is consumed, the pressure applied to the remaining amount detecting element 10 decreases, and the output voltage of the sensor including the remaining amount detecting element 10 increases as shown in FIG. By comparing this sensor voltage with a certain threshold voltage, the timing for supplying the developer 4 from the developer supply member 5 is notified by a display means (not shown) or by sound, voice, etc. ing.

The developer 4 tends to solidify if it is not used for a long time or in an environment of high temperature and high humidity, resulting in a phenomenon called blocking. For this reason,
As a means to break the blocking state of the developer 4,
The aforementioned transport member 7 is provided which serves as a stirring member.

In addition, the developer 4 also adheres to the detection surface of the remaining amount detection element 10, and blocking also occurs in the peripheral area, so the vibration of the detection surface is prevented, and even when the developer 4 is empty, an empty display is displayed. A malfunction may occur due to failure to do so. Therefore, in this embodiment, the first
As shown in the figure and FIG. 2, a conveyance member 7 as a stirring member is provided in close proximity to the remaining amount detection element 10, and this conveyance member 7 removes the developer 4 adhering to the detection surface and blocks the developer 4. I'm trying to break it down.

In this case, in the case where a piezoelectric element or the like is used as the remaining amount detection element 10 to detect changes in the vibration of the detection surface, it is possible to remove the developer 4 adhering to the detection surface or break up the blocked developer 4. Therefore, a problem arises in that a change in the pressure applied to the sensing surface causes malfunction.

Therefore, in this embodiment, as shown in FIG. 1, a thin plate-shaped stirring member 11 is provided at the tip of the conveyance member 7, not in contact with but very close to the detection surface of the remaining amount detection element 10. By rotating, the developer 4 adhering to the remaining amount detection element 10 is removed. Note that Figure 1 is from A-A in Figure 2.
A line cut sectional view is shown.

As shown in FIG. 4, the stirring member 11 has a hollow, thin disc shape, and its center portion is connected in the radial direction by a bridge portion 12. As shown in FIG.
It is attached to the tip of the transport member 7 and rotated in synchronization with the transport member 7. And this stirring member 11
When the developer rotates, the developer attached to the detection surface of the remaining amount detection element 10 is removed by the bridge portion 12.

Further, the detection surface of the remaining amount detection element 10 is retracted by a distance d from the inner wall surface of the developing machine main body 1, and the conveyance member 7 is rotated by being pressed in the direction of arrow C by means not shown. Therefore, stirring member 1
The gap d between the sensor 1 and the sensing surface is kept constant.

As a result, even if the conveying member 7 rotates,
No force is applied to the remaining amount detection element 10 in the vertical direction to the detection surface thereof. Further, the change in pressure caused by the developer 4 is transmitted to the remaining amount detection element 1 through the through hole of the stirring member 11.
Since it is added to 0, the remaining amount can be detected normally. Further, at this time, since the stirring member 11 is in the shape of a thin disk, even if the stirring member 11 rotates, the developer 4
is not pressed toward the detection surface of the remaining amount detection element 10, and the pressure applied to the detection surface of the remaining amount detection element 10 does not change.

As described above, according to the present embodiment, when breaking the blocked developer 4, no pressure other than the pressure due to the remaining amount of the developer 4 is applied to the detection surface, so that malfunctions due to the operation of the stirring member 11 can be prevented. .

Here, since the stirring member 11 according to this embodiment does not contact the sensing surface, the developer 4 may remain attached by the gap d (see FIG. 1) between the stirring member 11 and the sensing surface. be.

However, according to experiments, the characteristics of the remaining amount detection element 10 are such that if the gap d is 1 mm or less, the original developer remaining amount height and sensor output voltage characteristics do not change as shown in FIG. It has been confirmed. In other words, if the amount of developer 4 attached to the detection surface is suppressed to a thickness of 1 mm or less, vibrations will not be affected. On the other hand, when the developer 4 with a thickness of 1 mm or more adheres to the developer 4, the output of the remaining amount detection element 10 gradually decreases, causing malfunction.

FIG. 5 shows another embodiment of the present invention.
A coil spring is formed from a part of the conveying member 7, and the gap d is kept constant by the elasticity of the coil spring.

6 and 7 show a front sectional view and a side view of still another embodiment, in which a thin rod-shaped body 13 is formed by bending the tip of a conveying member 7 having a coil spring configuration in the direction of its central axis. is used as a stirring member. Also in this embodiment, since the rod-shaped body 13 does not directly contact the remaining amount detection element 10, malfunction will not occur.

[Effect of idea]

As described above, according to the present invention, the stirring member is operated in a non-contact and close proximity to the detection surface of the remaining amount detection element. Thereby, the developer attached to the detection surface and the developer blocked around the detection surface can be removed without changing the pressure applied to the detection surface of the remaining amount detection element. Therefore, it is possible to reliably detect the pressure due to the remaining amount of developer to accurately detect the remaining amount, and it is possible to supply the developer in just the right amount.

[Brief explanation of the drawing]

FIG. 1 is a partial front sectional view of the developing device according to the embodiment of the present invention, FIG. 2 is a side sectional view of the developing device according to the embodiment of the present invention, FIG. 3 is a graph showing the characteristics of the remaining amount detection element, and FIG. 1, FIG. 5 is a front sectional view of another embodiment of the present invention, FIG. 6 is a partial front sectional view of yet another embodiment of the invention, and FIG. 7 is a front sectional view of still another embodiment of the present invention. FIG. 7 is a side view of the stirring member shown in FIG. 6; 1...Developing machine main body, 2...Photoreceptor, 3...Developing roll, 4...Developer, 5...Developer supply member,
6... Developer storage section, 7... Conveying member, 8... Regulating member, 9... Developing section, 10... Remaining amount detection element,
11... Stirring member, 12... Bridge part, d...
gap.

Claims (1)

[Claims for Utility Model Registration] 1. A remaining amount detecting element for detecting the remaining amount of developer is provided in the developer accommodating section, and the developing agent is moved in a position close to and not in contact with the remaining amount detecting element. In a developing device of a copying machine provided with a stirring member for preventing blocking of the agent, a distance maintaining member keeps a constant distance between the sensing surface of the remaining amount detecting element and the stirring member; A developing device for a copying machine, comprising: a stirring member that moves while maintaining a constant distance between the stirring member and a detection surface to prevent blocking of the developer. 2. The developing device for a copying machine according to claim 1, wherein a gap between the detection surface of the remaining amount detection element and the stirring member is 0.1 mm or more and 1.0 mm or less. 3. The developing device for a copying machine according to claim 1 or 2, wherein the stirring member is a thin plate-like member. 4. The developing device for a copying machine according to claim 1 or 2, wherein the stirring member is a thin rod-shaped member.