JPH07199656A - Toner supplying device - Google Patents

Abstract

PURPOSE:To always supply the specified amount of toner regardless of toner amount housed in a bottle, that is, the residual amount of the toner and the flow property of the toner caused by the change of environmental condition by forming a magnetic field in a measuring chamber in a supplying condition and eliminating the magnetic field from the measuring chamber in a discharging condition. CONSTITUTION:When a measuring sleeve 11 rotates in a direction shown by an arrow (a), the bottle 3 rotates with the sleeve 11. Thus, the magnetic toner 2 housed in the bottle 3 is pressed by a helical guide projection so as to move toward a discharging port 6. The toner 2 is supplied to the measuring chamber 28 of the measuring cover 26 through the discharging ports 6 and 25 in a condition where the port 6 faces downward (toner supplying condition), so that the chamber 28 is filled with the toner 2. At this time, the magnetic field is formed by a permanent magnet 31 on the chamber 28, and the toner 2 with which the chamber 28 is filled forms a magnetic brush having specified density based on the intensity of the magnetic field. When the chamber 28 is out of the magnetic field of the magnet 31, the toner 2 restricted by the magnetic field freely falls into a falling path 18 so as to be supplied to a developing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for supplying powder magnetic toner to a developing device in an image forming apparatus such as a copying machine or a printer which uses a powder developer.

[0002]

2. Description of the Related Art Conventionally, as the toner supply device, a toner is contained in a bottle provided with a spiral guide protrusion along an inner peripheral surface of a cylindrical container, and the bottle is arranged in a substantially horizontal state and is arranged in a circumferential direction. It is known that toner is transferred to one end side by the spiral guide protrusion while rotating, and toner is intermittently dropped and supplied through a discharge port at the end.

[0003]

However, in the toner supply device described above, as is clear from FIG. 15 showing the relationship between the number of times toner is supplied (the number of rotations) and the amount of toner supplied per time, the number of rotations increases. That is, there is a problem that the toner supply amount decreases as the storage amount decreases, and stable toner supply cannot be achieved.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in a toner supply device for discharging and supplying magnetic toner through a discharge port provided in a toner storage bottle, Switching means for switching the measuring chamber to a supply state in which the toner is supplied so as to face the discharge port and a discharge state in which the supplied toner is discharged, and a magnetic field is formed in the measuring chamber in the supply state to perform measurement in the discharge state. And a magnetic field forming means for removing the magnetic field from the chamber.

[0005]

According to the above construction, in the toner supply state,
Magnetic toner is supplied from the toner storage bottle to the measuring chamber. At this time, the magnetic field forming means forms a magnetic field in the measuring chamber,
A certain amount of magnetic toner formed in this magnetic field is filled in the measuring chamber. Next, when switching to the toner discharge state,
The magnetic field disappears from the measuring chamber, and the magnetic toner is released from the binding force of the magnetic field and discharged from the measuring chamber.

[0006]

EXAMPLES A toner supply device according to the present invention will be described below. 1 to 3, in the toner supply apparatus indicated by reference numeral 1 as a whole, the bottle 3 containing the magnetic toner 2 is formed of a cylindrical body whose both ends are closed.
The guide protrusion 5 protruding inward is formed in a spiral shape. Further, a toner discharge port 6 is formed near the end of the guide protrusion 5, and the outer side thereof is surrounded by a seal member 7.

A measuring device 9 for measuring the magnetic toner discharged from the bottle 3 and supplying it to the developing device 8 is composed of a holder 10 and a measuring sleeve 11. The holder 10 is composed of a cylindrical body 12, one end side of which is covered with a wall 14 having a through hole 13 in the central portion, and the other end side thereof is covered with an annular cover 15. Two annular guides 16 and 17 are provided on the inner peripheral portion of the cylindrical body 12,
A drop path 18 communicating with the developing device 8 is formed on an oblique side portion of the cylindrical body 12 sandwiched between the guides 16 and 17. Further, an engaging projection 19 is formed above the drop path 18 and projects inward along the side portion of the one guide 16.

The measuring sleeve 11 is composed of a cylindrical body 20 whose one end side is open. The measuring sleeve 11 is concentrically arranged inside the holder 10, and a rotary shaft 22 provided at the center of a wall 21 closing the other end side penetrates the measuring sleeve 11. It is projected to the outside through the hole 13,
The drive of a motor (not shown) is transmitted to the rotary shaft 22 and rotated in the direction of arrow a. Further, two annular guides 23 and 24 are provided on the outer peripheral portion of the cylindrical body 20,
These annular guides 23, 24 are located close to the inside of the annular guides 15, 16 of the holder 10. further,
A toner discharge port 25 is formed on the outer peripheral portion of the cylindrical body 20 between the annular guides 23 and 24, and a measuring cover 26 and a magnet holder 27 are provided outside the discharge port 25.

A measuring chamber 28 is formed in the measuring cover 26 so as to face the discharge port 25, the upstream end of the sleeve in the sleeve rotation direction is rotatably supported by the guides 23 and 24, and is opened by a spring 29 in the opening direction. Being energized. Further, as shown in FIG. 4, the free end portion of the weighing cover 26 is provided with an engaging claw 30 on the guide 23 side, and when the sleeve 11 rotates in the direction of the arrow a, the holder 10 is provided above the drop path 18.
The engaging projection 19 provided on the inner peripheral portion of the is engageable. On the other hand, the magnet holder 27 is provided with a permanent magnet 31 as shown in FIGS.
6 is arranged outside of the guide 6, and the upstream end in the sleeve rotation direction is guided by the guide 2 so that the permanent magnet 31 can advance and retreat to the measuring chamber 28.
It is rotatably supported by 3, 24 and is urged in the opening direction by a spring 32.

Therefore, the measuring sleeve 11 rotates in the direction of the arrow a, and the magnet holder 2 is placed above the drop path 18.
7 and the measuring cover 26 move, the magnet holder 27 and the measuring cover 26 respectively move the spring 3
It operates in the opening direction based on the biasing forces of 2,29. At this time, in the weighing cover 26, the engaging claw 30 of the measuring cover 26 is engaged.
And the rotation is regulated with the weighing chamber 28 facing the drop path 18. However, the magnet holder 27 is not engaged with the engaging protrusion 19 and is separated from the measuring cover 26, and the measuring chamber 2
8 is out of the magnetic field of the permanent magnet 31. When the measuring sleeve 11 is further rotated from this state, the measuring cover 26 is rotated in the closing direction while being in contact with the engagement protrusion, and the magnet holder 27 is rotated in the closing direction while being in contact with the inner peripheral surface of the holder 10. With the outlet 25 facing upward, the outlet 25 is completely covered by the measuring cover 26, and the magnet holder 27 is superposed on the outer side of the measuring cover 26.

In the above structure, the bottle 3 is loaded inside the measuring sleeve 11 and the discharge port 6 is connected to the measuring sleeve 1.
It is fixed in conformity with the discharge port 25 of No. 1. Therefore,
When the drive of a motor (not shown) is transmitted to the rotating shaft 22 and the measuring sleeve 11 rotates in the direction of arrow a, the bottle 3 rotates together with the measuring sleeve 11. This allows
The magnetic toner 2 contained in the bottle 3 is pushed by the spiral guide protrusion 5 and is transported toward the discharge port 6. Then, with the discharge port 6 facing downward (toner supply state),
The toner 2 is supplied and filled into the measuring chamber 28 of the measuring cover 26 through the discharge ports 6 and 25. At this time, the weighing room 2
A magnetic field is formed at 8 by a permanent magnet 31, and the filled toner 2 forms a magnetic brush having a constant density based on the strength of the magnetic field. Therefore, the amount of filled toner is constant.

Next, when the measuring cover 26 and the magnet holder 27 move above the drop path 18 and disengage from the inner peripheral surface of the holder, the measuring cover 26 and the magnet holder 27 are provided with springs 29 and 32. It rotates in the opening direction by the force. Further, the weighing cover 26 engages with the engaging projection 19, and the operation in the opening direction stops when the weighing chamber 28 faces the drop path 18. However, the magnet holder 27 is further rotated in the opening direction without engaging with the engagement protrusion 19,
Move away from the weighing cover 26. Then, when the measuring chamber 28 deviates from the magnetic field of the permanent magnet 31, the toner 2 restrained by this magnetic field freely falls into the dropping path 18 and is supplied to the developing device 8. After that, when the measuring sleeve 11 further rotates in the direction of arrow a, the measuring cover 26 and the magnet holder 2 are rotated.
7 slides in the closing direction while sliding on the engaging projection 19 and the inner peripheral surface of the holder 10, and the measuring cover 26 closes the discharging port 25 at a position where the discharging port 25 faces upward. A magnet holder 27 is superposed on the outside of 26. After that, the above-described operation is repeated, and a constant amount of toner is filled in the measuring chamber 28 regardless of the amount of toner contained in the bottle 3 and the toner is supplied to the developing device 8.

The relationship between the number of times the toner was supplied by the toner supply device 1 and the amount of toner discharged was determined by experiments. The condition during the experiment is that the temperature is 25 when the toner is supplied 0 to 50 times.
C, humidity 45% RH, temperature 30 up to 51 to 100 times
℃, humidity 85% RH (high temperature and high humidity conditions) 101-400
The temperature was set to 25 ° C. and the humidity was set to 45% RH again.
When the number of times of toner supply was 200, the toner supply was temporarily interrupted and the toner supply device 1 was left for a long time.

As a result, as shown in FIG. 8, even if the amount of toner in the bottle 3 decreases as the number of times of toner supply increases, the amount of toner discharged at one time is stable at around 300 mg, and the temperature is high. The amount of discharged toner was stable even under the condition of humidity. Further, the toner discharge amount was stable even after the toner supply was temporarily interrupted and the toner supply device 1 was left for a long time. This indicates that a certain amount of toner is stably supplied even if moisture is absorbed by the toner by leaving the toner supply device 1 for a long time.

Next, a second embodiment of the present invention will be described. As shown in FIG. 9, the toner supply device 35 of the present embodiment.
Then, on the outer periphery of the cylindrical bottle 36 with both ends closed,
A slit-shaped outlet 37 is formed parallel to the central axis,
The outside of the discharge port 37 is surrounded by a seal member 38. The holder 39 is composed of a cylindrical body having an opening 40 at one end, and the toner drop path 4 is provided obliquely below the outer periphery.
1 is formed, and this drop path 41 is connected to the developing device 42. The measuring sleeve 43 is composed of a cylindrical body having one end opened, is housed in the holder 39, and is rotated in the direction of arrow b based on the drive of a motor (not shown).
Further, the measuring sleeve 43 has a slit-shaped discharge port 44 formed in parallel with the central axis thereof, and a measuring cover 45 and a magnet holder 46 are provided outside the discharge port 44.

The measuring cover 45 has a measuring chamber 47 facing the discharge port 44, is rotatably supported at the upstream end of the measuring sleeve 43 in the rotational direction, and is provided with the spring 4.
It is urged in the opening direction by 8. On the other hand, the magnet holder 46 is provided with a permanent magnet 49, is rotatably supported by the end of the measuring sleeve 43 on the upstream side in the rotational direction, and is brought into contact with and separated from the outer surface of the measuring cover 45. Is biased in the opening direction by. And
When the measuring sleeve 43 rotates in the direction of the arrow b and the discharge port 44 moves above the drop path 41, the measuring cover 45 and the magnet holder 46 rotate in the opening direction by the urging forces of the springs 48 and 50, respectively, and the measuring chamber. 47 is the fall path 41
And the magnet holder 46 is separated from the measuring sleeve 43, so that the measuring chamber 47 is separated from the magnetic field of the permanent magnet 49.

In the above structure, the bottle 36 is loaded into the measuring sleeve 43, and the discharge ports 37 and 44 of both are aligned and fixed. Therefore, when the measuring sleeve 43 rotates in the direction of the arrow b based on the driving of a motor (not shown), the bottle 36 rotates together with the measuring sleeve 43, and the magnetic toner 51 is transferred toward the discharge port 37.
The toner 5 is put in the measuring chamber 47 with the discharge port 37 facing downward.
1 (see FIG. 10). The amount of toner filled in the measuring chamber 47 is constant depending on the magnetic field strength of the permanent magnet 49. Next, the weighing cover 45 and the magnet holder 4
When 6 moves above the drop path 41, the engagement with the inner peripheral surface of the holder 39 is released, as shown in FIG.
It is opened by the urging force of 8,50. Further, the measuring cover 45 stops its operation in the opening direction at the position where the measuring chamber 47 faces the drop path 41. However, the magnet holder 46
Is further rotated by a predetermined angle from the stop position of the measuring cover 45 and separated from the measuring cover 45. As a result, the toner 51 in the measuring chamber 47 is removed from the magnetic field of the permanent magnet 49, and the filled toner 51 is dropped and supplied to the developing device 42 via the dropping path 41. After that, based on the rotation of the measuring sleeve 43, the measuring cover 45 and the magnet holder 46 rotate in the closing direction while being in contact with the inner peripheral surface of the holder 39, the measuring cover 45 closes the discharge port 44, and the magnet holder 46 moves. It is stacked on the outside of the weighing cover 45. After that, the above-mentioned operation is repeated, and a certain amount of toner 5 filled in the measuring chamber 47 is filled.
1 is supplied to the developing device 42.

A third embodiment of the present invention will be described. As shown in FIG. 12, in the toner supply device 55, a cap accommodating portion 58 is formed on the upper portion of the measuring device main body 57 that is detachably connected to the developing device 56, and the cap 59 is fitted into the cap accommodating portion 58. Has been done. The cap 59 is provided with a cylindrical bottle mounting portion 60 that is open upward in the central portion, and a screw 61 is formed on the inner peripheral surface of the bottle mounting portion 60. Cap housing 5
7, a cylindrical measuring device accommodating chamber 62 is formed coaxially with the bottle mounting portion 60.
A disk-shaped weighing block 63 is arranged in the. A through hole 6 is formed in the center of the weighing block 63 and the cap 59.
4, 65 are formed, and the through hole 6 is formed in the main body 57 of the measuring instrument.
Through holes 66 that communicate with the rotary shaft 6 are formed in the through holes 64 to 66.
8 is inserted and the weighing block 63 is fixed to the rotary shaft 68. The measuring device main body 57 and the cap 59 are formed with discharge ports 69 and 70 communicating with the bottom of the bottle mounting portion 60, and the measuring block 63 is vertically penetrated through the discharge port 70.
A measuring chamber 71 that can face the A permanent magnet 72 is embedded in the measuring device body 57 below the discharge port 70. Further, the measuring device main body 57 is provided with a toner dropping path 73 which communicates with the measuring device accommodating chamber 62 from the bottom. Furthermore, a stirring rod 74 is attached to the upper end portion of the rotary shaft 68 protruding from the bottle mounting portion 60.

In the above structure, the bottle 76 containing the magnetic toner 75 is fixed by screwing the screw 77 provided on the outer periphery of the mouth thereof to the screw 61 of the bottle mounting portion 60, and the stirring rod 74 of the bottle 76. Inserted inside. This bottle mounting operation is performed in a state in which the measuring device main body 57 is removed from the developing device 56 and the illustrated state is reversed upside down. Bottle 7
As shown in the figure, the main body 57 of the measuring instrument equipped with 6 is fixed by connecting the toner dropping path 73 to the developing device 56. When the motor 67 is driven to rotate the rotating shaft 68 in this state, the stirring rod 74 stirs the toner 75 while moving inside the bottle 76. Also, the weighing block 63 rotates,
With the measuring chamber 71 facing the discharge ports 69 and 70,
The toner 75 in the bottle 76 drops into the measuring chamber 71 through the discharge ports 69 and 70 and is filled (see FIG. 13). At this time, the pressure of the toner in the measuring chamber 71 varies depending on the amount of toner stored in the bottle 76, but a magnetic field is formed in the measuring chamber 71 of the measuring block 63 by the permanent magnet 72. Only a certain amount of magnetic toner 75 is filled in the measuring chamber 71. Weighing block 6
When 3 further rotates, the discharge port 70 is closed by this measuring block 63. When the measuring chamber 71 faces the dropping port 73, the measuring chamber 71 is out of the constraint of the magnetic field of the permanent magnet 72 at this position, and all the toner 75 filled in the measuring chamber 71 is developed via the dropping port 73. It is dropped and supplied to the device 56 (see FIG. 14).

[0020]

As is apparent from the above description, in the toner supply device according to the present invention, the magnetic toner is supplied to the measuring chamber in the toner supply state by the magnetic field formed by the magnetic field forming means, and the toner is discharged. When switched, the magnetic field disappears from the metering chamber and the filled toner is discharged. Further, the amount of magnetic toner filled in the measuring chamber is determined by the strength of the magnetic field formed in the measuring chamber by the magnetic field forming means, and changes in the amount of toner contained in the bottle, that is, the remaining amount of toner and changes in environmental conditions. Regardless of the resulting fluidity of the toner, a constant amount of toner is always supplied.

[Brief description of drawings]

FIG. 1 is a perspective view of a toner supply device according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a perspective view of a weighing cover.

FIG. 5 is a perspective view of a magnet holder.

FIG. 6 is a sectional view of a magnet holder.

FIG. 7 is a partial cross-sectional view of a state in which toner is discharged from the measuring cover.

FIG. 8 is a graph showing the relationship between the toner supply count and the toner discharge amount in the first embodiment.

FIG. 9 is a perspective view of a toner supply device according to a second embodiment.

FIG. 10 is a partial cross-sectional view of a state where the toner according to the second exemplary embodiment is filled in the measuring chamber.

FIG. 11 is a partial cross-sectional view showing a state in which the toner according to the second exemplary embodiment is discharged from the measuring chamber.

FIG. 12 is a sectional view of a toner supply device according to a third embodiment.

FIG. 13 is a model diagram showing a state where toner is filled in a measuring chamber.

FIG. 14 is a model diagram showing a state in which toner is discharged from the measuring chamber.

FIG. 15 is a graph showing the relationship between the number of times toner is supplied and the amount of toner discharged in a conventional toner supply device.

[Explanation of symbols]

1 ... Toner supply device, 2 ... Magnetic toner, 3 ... Bottle, 6
... Toner discharge port, 26 ... Measuring cover, 27 ... Magnet holder, 28 ... Measuring chamber.

Claims (1)

[Claims] 1. A toner supply device for discharging and supplying magnetic toner through a discharge port provided in a toner storage bottle, and a measuring chamber and a supply state in which the measuring chamber faces the discharge port and is supplied with toner. And a magnetic field forming means for forming a magnetic field in the measuring chamber in the supplying state and for eliminating the magnetic field from the measuring chamber in the discharging state. .