JPH04358179A - Residual toner detecting device - Google Patents

Abstract

PURPOSE:To precisely detect residual toner at low cost, even when a magnet does not have accurate fixed magnetic force. CONSTITUTION:A supporting member 10 supporting a rocking member 11 so as to freely rock it is attached to a shaft 7. A flat plate 11a on which toner is ridden and a magnet 12 are provided on the rocking member 11. On the other hand, a rocking member 14 provided with a supporting member 13 and a magnet 15 and a position detecting sensor 16 are disposed outside a toner tank. In the magnets 12 and 15, the sides of the same polarity are opposed each other. When the toner is ridden on the flat plate 11a by a fixed quantity or more, the rocking member 14 is rotated by the repulsive force of the magnet to detect the fact by a sensor 16, so that the quantity of the residual toner can be detected without requiring precision on the magnetic force of the magnet.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remaining toner amount detection device for detecting the amount of toner remaining in a toner tank of a developing device installed in an image forming apparatus such as a copying machine.

0002

2. Description of the Related Art As a conventional toner remaining amount detection device, there is one that uses a piezoelectric sensor 40, as shown in FIG. 12, for example. However, this type of toner has problems in that it is expensive and the pressure of the toner itself is low, making it easy to detect errors. Furthermore, it becomes necessary to provide a member for scraping off toner adhering to the sensor surface.

[0003] Furthermore, as shown in FIGS. 13 to 15, there is also a type that uses a magnet. In the one shown,
A supporting member 53 is fixed to a shaft 51 in the toner tank 50, and a hole 54a of a swinging member 54 is inserted into a protrusion 53a of the support member 53, so that the support member 53 is swingably mounted. A magnet 55 is fixed to the swinging member. When the shaft 51 is rotated in this state, the swinging member 54 rides on the toner 52 depending on the remaining amount of toner, and a gap is created between it and the case of the toner tank 50. A magnetic detection device 56 provided outside corresponding to this gap detects the magnetism of the magnet 55 and indirectly detects the remaining amount of toner. In this case, the relationship between the distance between the magnet and the magnetic detection device and the magnetic force is known in advance.

[0004] However, in such a device, it is necessary to accurately grasp the magnetic force of the magnet, and there is a problem in that the magnetic force changes over time, and the cost of the magnetic detection section is high.

[0005]

Problem to be Solved by the Invention The present invention solves the above-mentioned problems in the prior art, and uses the magnetic force of a magnet, but does not require an accurate constant magnetic force, and provides a low cost and accurate toner. An object of the present invention is to provide a toner remaining amount detection device that can detect the remaining amount of toner.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a toner tank containing toner, a shaft that rotates within the toner tank, and one end of which is connected to the toner tank. a support member fixed to a shaft and having a coupling portion on the other end; a loading surface that is swingably coupled to the coupling portion on the other end and rotates the bottom of the toner tank by rotation of the shaft and on which toner is placed; and a magnet. a rocking member having a first rotational moment that rotates in the direction of the bottom portion, an external rocking member, and a detection means, the external rocking member comprising:
An opposing magnet is provided at a position outside the bottom of the toner tank and faces the magnet when the magnet rotates around the bottom, and the opposing surface has the same polarity as the magnet, and the opposing magnet is attached to the toner tank. A second toner tank is supported by the toner tank so as to be able to swing toward or away from the bottom of the toner tank, and rotates in the approaching direction.
The detection means has a rotational moment and is restricted from swinging in that direction, and includes a detected part, and the detection means detects the detected part when the opposing magnet rotates in a direction away from the bottom part, and the detection means detects the detected part when the opposing magnet rotates in a direction away from the bottom part. The moment is smaller than the moment caused by the repulsive force between the magnet and the opposing magnet, and the force acting on the center of the opposing magnet generates a moment that balances the second rotational moment, and the amount of toner on the loading surface. The moment due to the weight of the toner and the force that generates a moment that balances the first rotational moment that acts on the swinging member when the toner is placed on the swinging member are opposite in direction and equal in magnitude;
In addition to the above, the invention according to claim 2 is characterized in that there are a plurality of sets of the rocking member and the external rocking member, and the predetermined amount or the height of the toner loaded on the loading surface is determined by the number of sets of the rocking member and the external rocking member. The invention according to claim 3 is characterized in that, in addition to the feature of the invention according to claim 2, the distance from the center of oscillation of the magnet and the distance from the center of oscillation of the opposing magnet are different from each other in the oscillation. The invention of claim 4 is characterized in that each set of the member and the external rocking member is different from each other.
In addition to the feature of the invention, a plurality of the rocking members are provided within the same rotating plane of the supporting member, and the predetermined amount of each rocking member or the height of the toner loaded on the loading surface is different. A fifth aspect of the invention is characterized in that, in addition to the features of the second to fourth aspects, a display means is provided for displaying the remaining amount of toner based on the detection signal of the detection means.

[0007]

[Operation] According to the present invention, in the invention of claim 1,
The moment due to the repulsive force between the magnets is larger than the second rotational moment, and when a predetermined amount of toner is placed on the loading surface, the same force generated between the magnet and the opposing magnet causes the rocking member and the external rocking member to move, respectively. Since the rotating moments are equal, neither of the swinging members moves. However, when more toner than a predetermined amount is loaded on the toner, the swinging members do not move and a larger force is generated between the magnets, causing the external swinging member to move away from the bottom of the toner tank. It rotates in the direction of separation, and the detected part is detected by the detection means. As a result, it is detected that there is more than a predetermined amount of toner in the toner tank.

In the invention of claim 2, since a plurality of sets of the swinging member and the external swinging member are provided, each set having a different predetermined amount of toner or a different height, the above-mentioned effect occurs for each set. A plurality of different amounts of toner remaining can be detected.

In the third aspect of the invention, the distance from the center of vibration of the magnet and the distance from the center of vibration of the opposing magnet are different for each set of the rocking member and the external rocking member, so that the same rocking member and The same effect as the second aspect of the invention can be obtained by using the same magnet.

In the invention of claim 4, a plurality of rocking members are provided within the same rotational plane of the support member, and each rocking member has a different predetermined amount or height on which toner is placed, so that the number of external rocking members can be reduced. It is possible to detect multiple different toner levels without increasing the amount of toner remaining.

In the fifth aspect of the invention, since the display means is provided for displaying the remaining amount of toner based on the plurality of detection signals from the detecting means, it is possible to notify the user of the remaining amount of toner in two or more values.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of a developing device and a remaining toner amount detecting device according to an embodiment. The toner tank is formed by cases 1 and 2 and a side plate (not shown), and a toner cartridge 3 for supplying toner is disposed above the toner tank. Inside the toner tank, a toner agitation and conveyance member 8 attached to a shaft 7 is provided, and when this is rotated in the direction of the arrow in the figure, toner is transferred from the agitation member 4 via the toner supply member 5 to the developing section 6. is being supplied to.

A supporting member 10 that swingably supports a swinging member 11 is further attached to the shaft 7, and these members similarly rotate in the direction of the arrow as the shaft 7 rotates. The rocking member 11 moves near the case 1 regardless of the amount of toner 9.

As shown in FIGS. 2 and 3, the rocking member 11 is swingably supported at a fulcrum P, and includes a flat plate 11a, which is a loading surface on which toner is placed by rotation, and a flat plate 11a with a surface side N on the lower surface side.
A magnet 12 serving as a pole is provided. The magnet 12 may have a magnetic force of 250 Gauss or more on its magnetized surface.

On the other hand, on the outside of the toner tank, a support member 13, a swinging member 14, and a position detection sensor 16 (a photointerrupter is used in this embodiment) as detection means are arranged. The rocking member 14 has a shaft 14 as shown in FIG.
The magnet 15 is supported in a freely swingable manner at a point a, and a magnet 15 whose surface side is the north pole is provided on the tip side thereof, as also shown in FIG. Like the magnet 12, the magnet 15 may have a magnetic force of 250 Gauss or more on its magnetized surface.

With this configuration, when the shaft 7 is rotated, the swinging member 11 reaches the bottom portion 1a of the toner tank and is brought to a position where the magnets 12 and 15 face each other, as shown in FIGS. 1 and 6. come. At this time, since the same poles of the magnets face each other, a repulsive force acts between the magnets, and the rocking member 11 is lifted or the rocking member 14
The tip side where the magnet 15 is located is pushed down. The remaining amount of toner is detected by which swinging member is rotating.

FIG. 6 is a diagram for explaining the principle of this operation. In the rocking member 11 inside the toner tank, the distance from the rotational fulcrum P to a position near the center of the flat plate 11a on which the toner weight mg is applied is l1, the distance to the center of the magnet 12 is l2, and the rocking member is the first rotational moment. Let M1 be the clockwise rotation moment around the center P caused by the weight of 11. In addition, in the swinging member 14 outside the toner tank, the magnet 1 is moved from the fulcrum (shaft 14a).
5 is L, and the counterclockwise rotation moment around the shaft 14a due to the own weight of the rocking member 14 as the second rotation moment is M2. Let F be the repulsive force acting on the center point between the magnets 12 and 15. Note that when no repulsive force acts on the rocking member 14, the rocking member 14
A left rotation moment M2 acts on the bottom portion 14b of the rocking member 14, as shown in FIGS. 1 and 4.
is regulated by being supported by the convex portion 1b of the case 1, and the swinging member 14 is kept substantially horizontal.

In such a state, when the magnets 12 and 15 come to a position where they face each other, if the rocking member 14 rotates clockwise, the protrusion 14c, which is the detected part, blocks the optical path of the position detection sensor 16. Sensor 16 detects this. The conditions for this rocking member 14 to rotate clockwise are as follows: M2 <
FL...................................(1).

Next, in order for this repulsive force F to be generated, when the repulsive force F acts on the rocking member 11, the rocking member 11 must not rotate counterclockwise and escape due to the principle of action/reaction. For this purpose, M1 +l1 mg > Fl2...
・It must be (2).

On the other hand, no matter how large the magnetic force of the magnet is, if FL becomes more than M2, the rocking member 14 will rotate, so FL will never become a larger value than M2. Therefore, the maximum value of F is F=M2
/L, so the formula (2) is: M1 +l1 mg > M2 /L・l2 m
>(l2 M2 −LM1 )/Ll1 g...(
3).

That is, as long as the repulsive force between the magnets is greater than a certain value (M2/L), the swinging member 14 uses the formula (3) as a predetermined amount of toner, regardless of its value.
If toner with a mass m or more shown in is placed on the flat plate 11a, 1
Once both magnets face each other during rotation, the position detection sensor 16 is turned on and the remaining amount of toner corresponding to the mass m is detected.

FIGS. 7 to 11 show other embodiments. Figure 7
2 shows a diagram in which the swinging member 11 is provided at two locations (there may be two or more locations) in the depth direction of the shaft 7 via the support member 10. On the other hand, on the outside of the toner tank,
Swing members 14 are provided at two locations. In this case, the predetermined amount of toner detected by each position detection sensor 16 or the height at which the toner is stacked is made different for each combination of the rocking members 11 and 14. To do this, the first or second rotational moment may be changed for each set of rocking members, or the area of the flat plate 11a on which the toner is loaded may be changed so that even if the amount of toner is the same, the height of the loaded toner is different. There are other methods.

FIG. 8 shows an example in which a hole 11a-1 is formed in the flat plate 11a to adjust the first rotational moment and change the toner loading amount (loading height).

Furthermore, when multiple sets of rocking members are provided as shown in FIG. 7, the positions of the magnets and opposing magnets can be changed for each set without changing the first or second rotation moment or the area of the flat plate 11a. By changing to , the repulsive force between the magnets that balances the second rotational moment differs for each set, and it is possible to detect different amounts of toner riding on the flat plate 11a as a predetermined amount.

FIG. 9 shows an embodiment in which two (or more than two) swinging members 11 are provided within the same rotational plane of the support member 10. In this case as well, by changing the first rotational moment of each swinging member 11 or changing the area of the flat plate 11a on which toner is loaded, the amount of toner detected by the position detection sensor 16 for each swinging member 11 can be changed. The predetermined amount or height should be different.

FIGS. 10 and 11 show an embodiment in which display means for displaying the remaining amount of toner based on the detection signal of the position detection sensor 16 is provided. FIG. 10 corresponds to the embodiment shown in FIG. One rotation time t1 of the shaft 7 is determined by the sensor 16.
When each set of rocking members 14 is detected in the interior and the sensor 16 is turned on, a large amount of toner remains is displayed, and the rocking continues even if the predetermined amount of toner is small or the height of loaded toner is low. When the member 14 rotates and only the set of rocking members detected is detected and turned on [(1) in the figure], a low amount of toner is displayed, and neither set of rocking members turns on. Sometimes, it will display that there is no toner remaining.

FIG. 11 corresponds to the embodiment of FIG. The contents of the display are the same as in the above case.

[0028]

As described above, according to the present invention, in the invention according to claim 1, a magnet is utilized by a simple configuration in which a rocking member satisfying a predetermined condition and an external rocking member are provided. However, the remaining amount of toner can be detected inexpensively and accurately without requiring much precision in the magnetic force of the magnet.

In the invention of claim 2, in addition to the above, since a plurality of sets of swinging members and external swinging members each having a different predetermined amount or height on which toner is placed are provided, some members may be added. By doing so, it is possible to detect a plurality of different amounts of remaining toner for each group.

In the third aspect of the invention, the distance from the rocking center of the magnet and the distance from the rocking center of the opposing magnet are different for each set of the rocking member and the external rocking member, so that the same rocking member and The same effect as the invention of claim 2 can be obtained using the same magnet.

In the invention of claim 4, a plurality of rocking members are provided within the same rotational plane of the support member, and each rocking member has a different predetermined amount or height on which toner is placed, so that the number of external rocking members can be reduced. It is possible to detect multiple different amounts of toner at a lower cost without increasing the amount of toner remaining.

[0032] In the invention of claim 5, since the display means is provided for displaying the remaining amount of toner based on the plurality of detection signals of the detecting means, by displaying the remaining amount of toner in two or more values, it is possible to determine when it is time to replenish the toner. It is possible to notify the user when it is time to replace the toner cartridge, thereby improving maintainability.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a remaining toner amount detection device according to an embodiment.

FIG. 2 is a perspective view of a swinging member of the remaining toner amount detection device.

FIG. 3 is a sectional view taken along line BB of the rocking member.

FIG. 4 is a perspective view of an external swinging member of the remaining toner amount detection device.

FIG. 5 is a sectional view taken along line CC of the external rocking member.

FIG. 6 is an explanatory diagram of the operation of the remaining toner amount detection device.

FIG. 7 is a perspective view of a rocking member according to another embodiment.

FIG. 8 is a perspective view of a rocking member of another embodiment.

FIG. 9 is a perspective view of a rocking member of still another embodiment.

10 is an explanatory diagram of display of remaining toner amount by the swinging member shown in FIG. 7; FIG.

11 is an explanatory diagram of display of remaining toner amount by the swinging member shown in FIG. 9; FIG.

FIG. 12 is an explanatory diagram of a toner remaining amount detection device using a conventional piezoelectric sensor.

FIG. 13 is a sectional view of a conventional toner remaining amount detection device using a magnet.

FIG. 14 is a perspective view of the swinging member of the remaining toner amount detection device.

FIG. 15 is a cross-sectional view taken along line AA of the rocking member.

[Explanation of symbols]

1 Case (toner tank) 1a Bottom 7 Shaft 10 Supporting member 11 Swinging member 11a Flat plate (loading surface) 12 Magnet 14 External swinging member 14c Projection (detected part) 15 Opposing magnet 16 Position detection sensor (detection means) M1
First rotation moment M2 Second rotation moment

Claims (5)

[Claims] [Claim 1] A toner tank containing toner;
a shaft that rotates within the toner tank; a support member having one end fixed to the shaft and provided with a coupling portion on the other end; an oscillating member having a first rotational moment that rotates in the direction of the bottom, an oscillating member having a magnet and a loading surface on which the toner is placed, an external oscillating member, and a detection means, the external oscillating member is provided with an opposing magnet whose opposing surface has the same polarity as the magnet at a position that is outside the bottom of the toner tank and faces the magnet when the magnet rotates on the bottom; The toner tank is supported by the toner tank so as to be able to swing toward or away from the bottom of the toner tank, has a second rotational moment that rotates in the approaching direction, and is restricted from swinging in that direction, and includes a detected portion. , the detection means detects the detected portion when the opposing magnet rotates in a direction away from the bottom, and the second rotational moment is smaller than a moment generated by a repulsive force between the magnet and the opposing magnet. , a force acting on the center of the opposing magnet that generates a moment that balances the second rotational moment, a moment due to the weight of the toner that acts on the rocking member when a predetermined amount of toner is placed on the loading surface, and the A toner remaining amount detection device characterized in that a force that generates a moment that balances the first rotational moment is opposite in direction and equal in magnitude. 2. A plurality of sets of the rocking member and the external rocking member, and the predetermined amount or the height of the toner stacked on the loading surface is different for each of the plurality of sets. The remaining toner amount detection device according to item 1. 3. The toner according to claim 2, wherein a distance from a rocking center of the magnet and a distance from a rocking center of the opposing magnet are different for each set of the rocking member and the external rocking member. Remaining amount detection device. 4. A plurality of the rocking members are provided within the same rotating plane of the support member, and the predetermined amount of each rocking member or the height of the toner loaded on the loading surface is different. The remaining toner amount detection device according to claim 1. 5. The remaining toner amount detecting device according to claim 2, further comprising a display means for displaying the remaining amount of toner based on the detection signal of the detecting means.