JPH0954488A - Toner stirring device for electrophotographic recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect that the quantity of toner remaining in a toner hopper is 'small.' SOLUTION: The device is provided with a stirring bar 9 which is rotated around a supporting shaft 8 so as to stir the toner 3 stored in the toner hopper 2, a driving gear 12 for rotating the stirring bar 9, and a magnetic sensor 11 for making the stirring bar raised with rotation by the driving gear 12 fall by gravity with rotation and detecting the quantity of the toner remaining in the toner hopper 2 based on the position of the stirring bar 9 just after the stirring bar 9 falls down, and the device is provided with a projection part 9a having a round tip part facing to a rotational direction on the front side in the rotational direction of the stirring bar 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner agitating device having a mechanism for detecting that the amount of remaining toner in a toner hopper of an electrophotographic recording device is low.

[0002]

2. Description of the Related Art FIG. 12 is a perspective view schematically showing a part of a conventional toner stirring device, and FIGS. 13 (a) and 13 (b) show a state immediately after a stirring bar 20 drops while rotating by its own weight. FIG. As shown in these drawings, the toner stirring device includes a toner hopper 2, a stirring bar 20 that rotates around a support shaft 8, and a drive unit that pushes a protrusion 8 a formed at the end of the support shaft 8. 12c and. When the drive unit 12c rotates in the A direction, the stirring bar 20
Rotates in the direction A together with the support shaft 8 and faces upward, and then falls while rotating by its own weight. FIG. 13 (a)
When the toner 3 remains in a considerable amount, the stirring bar 20 stops on the toner 3, as shown in FIG. At this time, since the magnetic field of the magnet 10 detected by the magnetic sensor 11 is weak, the control circuit (not shown) indicates that the toner remaining amount is “low”.
Determine not. On the other hand, as shown in FIG. 13B, when the toner remaining amount is very small, the stirring bar 20
Turns straight down and stops. At this time, the magnetic sensor 11
Detects a strong magnetic field of the magnet 10, and a control circuit (not shown) determines that the toner remaining amount is "small".

[0003]

However, there are cases in which solidified toner is formed in the toner hopper 2 due to thermal factors or excessive agitation. In this case, the stirring bar 20
Has hit the solidified toner 3a, and although the toner remaining amount is "small", the stirring bar 20 does not face directly below, and it cannot be detected that the toner remaining amount is "small", resulting in faint printing. There was a problem of stains and dirt.
It should be noted that in FIG.
It is explanatory drawing which shows the state stopped by hitting a.

Therefore, an object of the present invention is to provide a toner stirring device for an electrophotographic recording apparatus equipped with a mechanism capable of surely detecting that the toner remaining amount in the toner hopper is "small".

[0005]

According to a first aspect of the present invention, there is provided a toner agitating device for agitating a toner contained in a toner hopper by rotating a supporting shaft as a center, and a drive for rotating the agitating bar. A mechanism and the stirring bar lifted while being rotated by the drive mechanism,
The stirring bar is dropped while rotating, and a detection unit that detects the remaining amount of toner in the toner hopper based on the position immediately after the stirring bar is dropped is provided. It is characterized in that it is provided with a protrusion whose tip is directed in the direction of rotation.

A toner stirring device according to a second aspect of the present invention is
It is characterized by further comprising a blade-like member provided behind the stirring bar in the rotational direction and rotating with the rotation of the stirring bar to draw the toner in the toner hopper.

Further, the toner stirring device according to the third aspect is
The self-weight includes a stirring bar that stirs the toner stored in the toner hopper by rotating around the support shaft, a drive mechanism that rotates the stirring bar, and the stirring bar that is lifted while being rotated by the driving mechanism. And a detection unit that detects the remaining amount of toner in the toner hopper based on the position immediately after the stirring bar is dropped, and is provided behind the stirring bar in the rotation direction. It is characterized in that it has a blade-shaped member that rotates with the rotation of to draw the toner in the toner hopper.

A toner stirring device according to a fourth aspect is
The angle formed by the stirring bar and the blade-shaped member is 90 °.

A toner stirring device according to a fifth aspect of the present invention is
The blade-shaped member is formed to be short in the radial direction about the support shaft so that the tip of the blade-shaped member does not contact the inner wall of the toner hopper.

A toner stirring device according to a sixth aspect of the present invention is
The vane-shaped member is formed of a flexible film-shaped member that comes into contact with the inner wall of the toner hopper.

A toner stirring device according to a seventh aspect of the present invention is
It is characterized in that the detection means has a magnet provided on the stirring bar and a magnetic sensor provided on the bottom of the toner hopper.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment FIG. 1 is a partially cutaway side view schematically showing an I / D unit (image drum unit) including a toner stirring device of an electrophotographic recording apparatus according to a first embodiment of the present invention. FIG.
As shown in FIG. 1, the I / D unit includes a unit main body 1, a toner hopper 2 provided in the main body 1,
A toner cartridge 4 for supplying toner 3 into the toner hopper 2, a photosensitive drum 5, a developing roller 6 for supplying the toner 3 to the photosensitive drum 5, and a sponge roller 7 for supplying the toner 3 to the developing roller 6. Have. Further, inside the toner hopper 2, there is provided a stirring bar 9 which is attached so as to be rotatable around the support shaft 8 in the A direction. The stirring bar 9 rotates in the direction A around the support shaft 8 to stir the toner 3 contained in the toner hopper 2. A magnet 10 is built in the stirring bar 9, and a magnetic sensor 11 for detecting a magnetic field is provided at a position facing the magnet 10 on the bottom of the toner hopper 2. still,
The position of the stirring bar 9 is detected by the magnet 10 and the magnetic sensor 1.
It may be performed by means other than 1. 2A to 2C are views showing an example of another means for detecting the position of the stirring bar 9, and FIGS. 2A and 2B show a magnet 22 at the tip.
2 is an operation explanatory view showing that the sensor lever 21 provided with is rotated about the support shaft 23. FIG.
FIG. As shown in FIG. 2A, when the stirring bar 9 does not face directly below, the sensor lever 21
2 (the magnet 22 side) is at a position lowered by its own weight, and as shown in FIG. 2B, when the stirring bar 9 faces downward, the tip of the sensor lever 21 contacts the magnet 10 of the stirring bar 9. It is attracted and rotates (clockwise in the figure). The presence or absence of toner is determined based on the position of the sensor lever 21 detected by the sensor 24.

FIG. 3 (a) is a schematic perspective view of the front surface (the surface on the right side in FIG. 1) of the stirring bar 9 shown in FIG. 1, viewed obliquely, and FIG. 3 (b) is the same figure. FIG. 3C is a schematic side view when viewed in the B direction, and FIG. 3C is an enlarged perspective view illustrating the case when viewed in the C direction in FIG. As shown in FIG. 3A, on the front surface of the stirring bar 9 in the rotation direction, a plurality of protrusions 9a having tip ends of the mountain shape oriented in the rotation direction are provided. In addition, as shown in FIG. 3C, the support shaft 8
A projecting portion 8a is provided at the end of the. FIG.
In (a), the protrusion 9a is formed of a triangular prism-shaped member, but if the shape is suitable for crushing the solidified toner in the toner hopper 2, another shape such as a pointed cone or the like is used. It may be one.

FIG. 4 shows a stirring gear 1 for rotating the stirring bar 9.
FIG. As shown in FIG. 4, the stirring gear 12 has a cylindrical portion 12a rotatably supported on the side wall of the toner hopper 2 and a gear portion 12b connected to the cylindrical portion 12a. The support shaft 8 is inserted inside the tubular portion 12a. Further, a protruding driving portion 12c (also shown in FIG. 3C) is provided inside the cylindrical portion 12a, and when the stirring gear 12 rotates, the driving portion 12c is attached to the protruding portion 8a of the support shaft 8. The agitating bar 9 is rotated together with the supporting shaft 8 while contacting. Incidentally, 9b is a shaft which functions as a weight built in the tip side of the stirring bar 9.

FIG. 5 is an explanatory view showing a mechanism for rotating the stirring gear 12. As shown in FIG. 5, when the photosensitive drum 5 is rotated in the arrow direction by the driving force of a motor (not shown), the gear 13 and the gear 1 are rotated along with the rotation of the photosensitive drum 5.
4 and gear 15 rotate in the directions of the arrows, respectively, and gear 1
The stirring gear 12 meshing with the gear 5 rotates in the A direction.

FIGS. 6A to 6E are explanatory views showing the operation of the stirring bar 9 when a large amount of toner 3 is present in the toner hopper 2. The drive unit 12c of the stirring gear 12 rotates in the A direction at a constant speed in synchronization with the rotation of the photosensitive drum 5 by the mechanism shown in FIG. Drive unit 12 of stirring gear 12
When c comes into contact with the protruding portion 8a of the support shaft 8, the stirring bar 9 rotates in the A direction as shown in FIGS. 6 (a) and 6 (b), and is directly above as shown in FIG. 6 (c). When passing a little above, the stirring bar 9 rotates faster than the drive unit 12c by its own weight. At this time, the stirring bar 9 stops on the toner 3 accumulated in the toner hopper 2, as shown in FIG. Then, based on the output of the magnetic sensor 11 immediately after the drive unit 12c has moved directly above, a control circuit (not shown) determines whether or not the toner remaining amount in the toner hopper 2 is "small". In the case of FIG. 6D, the magnet 10 of the stirring bar 9 and the magnetic sensor 11 are separated, and the magnetic sensor 11 detects only a weak magnetic field.
It is determined that the remaining toner amount is not "low". After that, the drive portion 12c catches up with the protruding portion 8a of the support shaft 8,
As shown in (e), the stirring bar 9 is pushed into the toner 3, and then the operations shown in FIGS. 6 (a) to 6 (e) are repeated.

FIGS. 7A to 7E are explanatory views showing the operation of the stirring bar 9 when the solidified toner 3a remains in the toner hopper 2. As shown in FIG. Drive unit 12c of the stirring gear 12
However, when it comes into contact with the projecting portion 8a of the support shaft 8, the stirring bar 9 facing directly downward rotates in the direction A as shown in FIGS. 7 (a) and 7 (b), and as shown in FIG. 7 (c). As shown, the stirring bar 9 turns faster than the drive unit 12c by its own weight when it faces right above and slightly past right above, and collides with the solidified toner 3a. At this time, the tip of the protrusion 9a of the stirring bar 9 collides with the solidified toner 3a, so the solidified toner 3a is crushed and spreads to the bottom of the toner hopper 2 (becomes toner 3), and the stirring bar 9 is moved to the state shown in FIG. ) Face down and stop as shown in (). Therefore, the drive unit 12c
Immediately after is immediately above, as shown in FIG. 7 (d), the magnet 10 of the stirring bar 9 and the magnetic sensor 11 are close to each other, and the magnetic sensor 11 detects a strong magnetic field.
A control circuit (not shown) determines that the remaining amount of toner is "small". After that, as shown in FIG. 7E, the drive portion 12c catches up with the protruding portion 8a of the support shaft 8,
The operations (a) to (e) are repeated.

As described above, according to the toner agitating device of the first embodiment, even if the solidified toner 3a remains in the toner hopper 2, the solidified toner 3a is crushed by the protrusion 9a. Therefore, if the remaining toner amount is actually low, the remaining toner amount is surely "low".
Can be detected.

Second Embodiment FIG. 8 (a) is a perspective view schematically showing a case where the back surface of the stirring bar 16 of the toner stirring device according to the second embodiment of the present invention is obliquely looked down, FIG. 8 (b). FIG. 7A) is a side view schematically showing the case where FIG. As shown in FIG. 8A, a blade member 17 is provided at the rear of the stirring bar 16 in the rotation direction so as to form an angle of 90 ° with the stirring bar 16. The tip of the blade member 17 is formed slightly shorter than the stirring bar 16 in the radial direction around the support shaft 8 so as not to contact the inner wall of the toner hopper 2.

FIGS. 9A to 9E show the stirring bar 16 when the solidified toner 3a remains in the toner hopper 2.
It is an explanatory view showing the operation of. Drive unit 12 of stirring gear 12
c rotates in the direction A at a constant speed in synchronization with the rotation of the photosensitive drum 5. When the drive portion 12c of the stirring gear 12 comes into contact with the protruding portion 8a of the support shaft 8, the stirring bar 16 facing downward as shown in FIGS. 9A and 9B rotates in the A direction. At this time, the blade-shaped member 17, which rotates 90 ° later than the stirring bar 16, hits the solidified toner 3a and crushes it to leave the toner 3 on the bottom of the toner hopper 2. After that, the stirring bar 16 further rotates and faces upward as shown in FIG. When passing slightly above, the stirring bar 9 rotates faster than the drive unit 12c that rotates at a constant speed due to its own weight. At this time, the stirring bar 9 faces downward and stops as shown in FIG. In this case, the drive unit 12
Based on the output of the magnetic sensor 11 immediately after c comes directly above, it is determined whether or not the toner remaining amount is “small”. FIG.
In the case of (d), the magnet 10 of the stirring bar 9 and the magnetic sensor 11 are close to each other, and it is determined based on the signal of the magnetic sensor 11 that the toner remaining amount is “small”. After that, the drive unit 12c catches up with the protruding portion 8a, and the operation of FIGS. 9A to 9E is repeated. The toner stirring device according to the second embodiment is the same as the first embodiment except for the points described above.

As described above, according to the toner stirring device of the second embodiment, the stirring bar 9 is pushed by the driving portion 12c of the stirring gear 12 to rotate, and the process proceeds from FIG. 9A to FIG. 9B. In the meantime, since the toner 3a that has solidified in the toner hopper 2 can be crushed by the blade-shaped member 17, if the toner remaining amount is actually small, the toner remaining amount "small" can be reliably detected.

The stirring bar 16 shown in FIG. 8 may be provided with the protrusion 9a shown in FIG. 3 (a). In this case, the toner solidified by both the protrusion 9a and the blade member 17 can be removed. Therefore, it is possible to detect the remaining toner amount "small" more reliably.

Third Embodiment FIG. 10A shows a stirring bar 16 according to a third embodiment of the present invention.
1 is a schematic perspective view of the back surface of the vehicle as seen down obliquely, FIG.
0 (b) is a side view schematically showing the case where FIG. As shown in FIG. 10A, a flexible film member 19 is provided behind the stirring bar 16 in the rotation direction so as to form an angle of 90 ° with the stirring bar 16. The film-shaped member 19 is longer than the stirring bar 16 in the radial direction around the support shaft 8 so that the tip of the film-shaped member 19 contacts the inner wall of the toner hopper 2 (FIG. 10B).
In the above, L ₁ <L ₂ ) is formed.

11A to 11E show the toner hopper 2.
Stir bar 1 when toner 3a that has solidified inside remains
It is explanatory drawing which shows the operation | movement of 6. Drive unit 1 of stirring gear 12
2c rotates in the A direction at a constant speed in synchronization with the rotation of the photosensitive drum. When the driving portion 12c comes into contact with the protruding portion 8a, the stirring bar 16 located right below the driving portion 12c as shown in FIGS.
Rotates in the A direction. At this time, the stirring bar 16 is about 9
The film-like member 19 which rotates with a delay of 0 ° crushes the solidified toner 3a in the toner hopper 2, and at the same time scrapes off the toner adhering to the inner wall of the toner hopper 2. afterwards,
The stirring bar 16 is further rotated to face directly upward as shown in FIG. 11C, and when passing slightly above the stirring bar 16, the stirring bar 1
6 rotates faster than the drive unit 12c due to its own weight. At this time, the stirring bar 16 faces downward and stops, as shown in FIG. In this case, the drive unit 12
Based on the output of the magnetic sensor 11 immediately after c comes directly above, it is determined whether or not the toner remaining amount is “small”. FIG.
In the case of 1 (d), the magnet 10 of the stirring bar 9 and the magnetic sensor 11 are close to each other, and it is determined based on the signal of the magnetic sensor 11 that the toner remaining amount is "small". After that, as shown in FIG. 11E, the drive portion 12c is moved to the protruding portion 8
After catching up with a, the operations shown in FIGS. 11A to 11E are repeated. The toner stirring device according to the third mode is the same as the first mode except for the points described above.

As described above, according to the toner agitation device of the third embodiment, even if the toner 3a that has been solidified remains in the toner hopper 2, the toner 3a that is solidified by the film-like member 19 can be removed. Since the toner remaining amount can be removed, if the toner remaining amount is actually small, the toner remaining amount “small” can be reliably detected.

The stirring bar 16 shown in FIG. 10 may be provided with the protruding portion 9a shown in FIG. 3A. In this case, the protruding portion 9a is provided.
Since the solidified toner can be removed by both the film-shaped member 19 and the film-shaped member 19, the remaining toner amount "small" can be detected more reliably.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view schematically showing an I / D unit including a toner stirring device of an electrophotographic recording apparatus according to a first embodiment of the present invention.

2A and 2B are operation explanatory views showing that a sensor lever having a magnet at its tip rotates about a spindle, and FIG. 2C is a plan view of the sensor lever.

3 (a) is a schematic perspective view of the front side of the stirring bar in FIG. 1 when looking down diagonally, and FIG. 3 (b) is a schematic perspective view of FIG. 1 (a).
The side view which shows the case where it sees in a direction roughly, (c) is the perspective view which expands and shows the case where the figure (a) is seen in C direction.

FIG. 4 is a front view showing a stirring gear for rotating the stirring bar of FIG.

5 is an explanatory view showing a mechanism for rotating the stirring gear of FIG. 1. FIG.

6A to 6E are explanatory views showing the operation of the stirring bar when a large amount of toner is present in the toner hopper.

7A to 7E are explanatory views showing the operation of the stirring bar when the amount of toner in the toner hopper is small.

FIG. 8 (a) is a schematic perspective view when the back surface of the stirring bar according to the second embodiment is obliquely looked down, and FIG. 8 (b) is a schematic view when the same figure (a) is viewed in the B direction. FIG.

9A to 9E are explanatory views showing the operation of the stirring bar of FIG.

FIG. 10 (a) is a schematic perspective view when the back surface of the stirring bar according to the third embodiment is obliquely looked down, and FIG. 10 (b) is a schematic view when the same figure (a) is viewed in the B direction. FIG.

11A to 11E are explanatory views showing the operation of the stirring bar of FIG.

FIG. 12 is a perspective view schematically showing a toner hopper and a stirring bar of a conventional toner stirring device.

13 (a) and 13 (b) are explanatory views showing a state immediately after the stirring bar rotates and drops.

FIG. 14 is an explanatory diagram showing a state (conventional problem) in which the stirring bar is stopped by hitting the solidified toner.

[Explanation of symbols]

1 unit main body, 2 toner hopper, 3 toner, 3a solidified toner, 4 toner cartridge, 8 support shaft, 8a protruding part, 9,16 stirring bar, 9a protruding part, 10 magnet, 11 magnetic sensor, 12 stirring gear, 12a cylindrical Part, 12b
Gear part, 12c drive part, 13,14,15 gear, 17 vane-shaped member, 19 film-shaped member.

Claims (7)

[Claims] 1. A stirring bar that stirs toner contained in a toner hopper by rotating around a support shaft, a drive mechanism that rotates the stirring bar, and a lifted while rotating by the driving mechanism. A toner stirring device of an electrophotographic recording apparatus, comprising: a stirring bar that is rotated while being rotated by its own weight, and a detection unit that detects the amount of toner remaining in the toner hopper based on the position immediately after the stirring bar has dropped; A toner stirring device for an electrophotographic recording apparatus, comprising a protrusion having a mountain-shaped tip oriented in the rotation direction on the front surface of the stirring bar in the rotation direction. 2. The toner according to claim 1, further comprising a blade-shaped member provided behind the stirring bar in a rotation direction and rotating with the rotation of the stirring bar to draw the toner in the toner hopper. Stirrer. 3. A stirring bar that stirs toner contained in a toner hopper by rotating about a support shaft, a drive mechanism that rotates the stirring bar, and a lifted while rotating by the driving mechanism. A toner stirring device of an electrophotographic recording apparatus, comprising: a stirring bar that is rotated while being rotated by its own weight, and a detection unit that detects the amount of toner remaining in the toner hopper based on the position immediately after the stirring bar has dropped; 1. A toner stirring device, comprising a blade-shaped member provided behind a stirring bar in a rotational direction and rotating with the rotation of the stirring bar to scrape the toner in the toner hopper. 4. The toner stirring device according to claim 2, wherein an angle formed by the stirring bar and the blade-shaped member is 90 °. 5. The blade-shaped member is formed to be short in the radial direction around the support shaft so that the tip of the blade-shaped member does not contact the inner wall of the toner hopper. 5. The toner stirring device according to any one of 4 to 4. 6. The toner stirring device according to claim 2, wherein the blade-shaped member is formed of a flexible film-shaped member that comes into contact with the inner wall of the toner hopper. 7. The toner according to claim 1, wherein the detection unit has a magnet provided on the stirring bar and a magnetic sensor provided on the bottom of the toner hopper. Stirrer.