JP2870668B2 - Stirrer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirrer used for stirring toner in, for example, an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art For example, in an electrophotographic image forming apparatus such as an electrophotographic copying machine and a laser printer, a stirrer is provided in a developing device in order to attach toner to a surface of a carrier which is repeatedly used. Generally, in this type of stirrer, for example, as shown in FIG.
A stirring paddle 1 rotatably arranged in the stirring chamber 101
02 and a flow regulating plate 1 for guiding the developer 130 flowing in the stirring chamber 101 to one location on the outer periphery of the stirring paddle 102.
04 and a toner supply device 105 for supplying a toner 131 as one component of the developer 130 to one location on the outer periphery of the stirring paddle 102.

[0003] As the above-mentioned stirring paddle, for example,
Of the agitator 98 shown in US Pat.
And one with a single paddle on the shaft.
Like the stirring roller 5 shown in JP-A-49949.
Equipped with two paddles provided at 180 ° intervals in the rotation direction.
Some have more paddles, others have more paddles.
You. That is, as shown in FIG. 4 or FIG. 5, a pair of end plates 102a arranged at appropriate intervals on the rotation center axis.
Are disposed at appropriate intervals in the rotation direction.
And a plurality of band-shaped paddles 102b for connecting the two paddles 02a.
In some cases, a stirring paddle 102 is provided. Further, in order to enhance the stirring effect, the rotation direction of the stirring paddle 102 is moved from one side to the lower side of the stirring paddle 102 toward the stirring paddle 102 from the one side to the lower side. And the rotation direction of the stirring paddle 102 is changed from the top to the side of the chamber wall 1 on one side.
11 (counterclockwise in the figure).

[0004] The toner 131 supplied from the toner supply device 105 falls above the stirring paddle 102 in the stirring chamber 101, and is mixed with the carrier 132 made of magnetic spheres and the surplus toner 131, thereby forming the developer 130. Constitute. The developer 130 is sent to the lower part of the stirring chamber 101 while being stirred by the rotation of the stirring paddle 102. The stirred developer is moved to the stirring chamber 101 by the paddle 107.
Of the developing mag roll 10
8 is electrostatically attracted. A part of the developer 130 attached to the surface of the developing mag roll 108 is removed from the developing mag
The developer 130 adhered with a constant thickness to the surface of the substrate 08 is carried out to the development area 110. In the developing area 110, the developer 130 is electrostatically attracted to the electrostatic latent image formed on the surface of the photoconductor 200 by the developing mag roll 108, and
A toner image corresponding to the electrostatic latent image is formed on the surface of the toner image.

[0005] The developing mag roll 1 is
The developer 130 removed from 08 is guided above the stirring paddle 102 by the flow control plate 104, falls on the stirring paddle 102, and is supplied with the toner 131 from the toner supply device 105 as needed, and is again returned to the stirring paddle 102. Will be stirred.

[0006]

By the way, toner supply
When the toner 131 is supplied from the device 105, the stirring pad
Since the screw 102 is rotating counterclockwise in the figure,
-131 rides on the stirring paddle 102 and the flow control plate 104
And the stirring paddle 10 along the chamber wall 111.
2 while being fed down to
Are combined. However, for some reason, stir paddle 102 or
The developer in use is on the flow control plate 104
The toner 131 is supplied from the toner supply device 105 in the state.
Then, use on the stirring paddle 102 or the flow control plate 104
The toner rides on the developer inside, and this toner is
From the space between the nozzle 102 and the flow control plate 104
With the paddle 107
Developing mag roll on top of developer being scraped
108. The cause is the stirring paddle
Stirring pad between the outer peripheral surface of 102 and the flow control plate 104
Large in order to eliminate interference between the
Although a smaller gap is provided, the size of this gap is
The size increases or decreases with the rotation of the stirring paddle 102.
It is because it gets sick and changes. That is, for example, FIG.
As shown by the line, the paddle 102b is
This gap is small when it is located at the opposite position,
The gap between the paddle 102b and the flow control plate 104 is closed.
Gap between the stirring paddle 102 and the flow regulating plate 104
Stops flowing to the paddle 107 side through the
However, as shown by a virtual line in FIG.
Paddle 1 when moving away from the position facing regulation plate 104
02b and the flow regulating plate 104 increase the gap,
Pass this gap from above the paddle 102 and the flow control plate 104
As a result, the developer may flow to the scraping paddle 107 side.
You. The replenished toner rides on the escaping developer
The toner and the developer in use
And the paddle 102b from above the
It falls down through the gap with the flow control plate 104,
On the developer scraped by the scraping paddle 107
Ride and thoroughly agitate by the paddle 107
It may flow to the developing mag roll 108 immediately. this
Be sufficiently stirred by the stirring paddle 102
The toner 131 flowing toward the developing mag roll 108 adheres to the developing mag roll 108 as so-called raw toner, is carried out to the developing area 110, and is electrostatically attracted to the surface of the photoconductor 200, and the image quality or print quality is there because it may impair the. It is described in Japanese Utility Model Laid-Open No. 2-149949.
The stirring device corresponds to the toner supply device 105.
Hopper, stirring roller corresponding to stirring paddle 102, scraping
Pumping rotor and developing tuna corresponding to
Developing roller corresponding to the roller 108 and the blade 109
Corresponding doctor blade, flow control plate 104
A partition plate is provided.
Toner is dropped and supplied to the opposite side of the roller from the partition plate. This
The agitating roller of
Carry it to the board side and roll it down on the partition board side. And stirring
The roller is pumped up and has a smaller diameter than the rotor.
The pump rotor in the opposite direction to the stirring roller.
The agitating roller and the pumping low
Check the toner supplied between the printer and the developer in use.
, So that they can be mixed. And pumping
The developer whose components have been adjusted by stirring the
The lifting rotor feeds the developing roller that rotates in the same direction.
I am trying to start. Therefore, the actual actual value of the Japanese Utility Model 2-149
In the stirrer described in JP-A-949-949, a stirrer rotor and
The replenished toner develops when passing between the partition plate
And replenished toner even if they are not
The developer in use is between the stirring roller and the pumping rotor.
It is surely mixed by being caught in
May cause deterioration of image quality or printing quality
The agitating roller has a spiral plate around the outer periphery.
Develop the refilled toner while using it in the specified shape.
Irrespective of whether it is mixed with
It can be dropped down through the gap between the cutting board.
Also, a stirring device described in Japanese Utility Model Laid-Open No. 1-135454 is disclosed.
The toner tank corresponding to the toner supply device 105,
Agitator corresponding to stirring paddle 102, Raising paddle 1
07, the paddle corresponding to the developing mag roll 108
Magnet roller and developing sleeve, blade 109
Blades corresponding to the flow control plate 104
A lator is provided. The agitator side of this separator
The end face is the same as the partition plate of Japanese Utility Model Laid-Open No. 2-149949.
It is then vertically up to the vicinity of the agitator as is, and the lower end
The distance from the agitator increases with the rotation of the agitator
And getting smaller is still the same
Therefore, the same problem as the conventional example shown in FIG. 4 occurs.
The stirring device described in Japanese Utility Model Laid-Open Publication No. 1-135454.
Position the paddle above the paddle on the underside of the separator.
With the paddle at a position facing the dollar and farther from the developing sleeve.
The distance is large and close to the developing sleeve.
The separation is small, and the distance between them continuously decreases from large to small
An unusual paddle facing surface is provided, which
To a position close to the developing sleeve on the paddle facing surface
As it gets closer, so as to increase the dispersibility with the developer
doing. However, also in this case, the paddle facing surface and the paddle
Gap, especially between the paddle facing surface and the developing
Form between the paddle facing surface and the paddle at the end on the leave side.
The gap that is formed increases with the rotation of the paddle,
When the raw toner is on the paddle,
The developer is transported to the developing sleeve side
There is a problem that it cannot be reliably prevented.

The present invention has been made in view of the above circumstances, and does not allow unstirred components of an object to be processed to flow from between a flow regulating plate that guides the object to a stirring paddle and a stirring paddle. It is an object of the present invention to provide a stirring device as described above.

[0008]

According to the present invention, as shown, for example, in FIG. 1, a stirrer is provided above a scraping paddle 7 for supplying a developer 3 to a developing mag roll 8 to stir the supplied toner. paddle 2, developing from mag roll 8 be those leading to developer 3 removed by the blade 9 into the mixing paddle 2, the ends of that a plurality of the rotational direction paddles 2b
Flow control plate 4 extending toward stirring paddle 2 having
In order to achieve the above object, a stirrer having the following arrangement is provided with a flow prevention plate 6 at an end of the flow control plate 4, and the flow prevention plate 6 is provided along the outer periphery of the stirring paddle 2, and Pa
A measure is taken to extend the distance longer than the interval in the rotation direction of the dollar 2b .

[0009]

[Operation] In the present invention, the flow restricting plate 4 is provided at an end thereof.
When the girder escape prevention plate 6 extends along the outer periphery of the stirring paddle 2,
The paddle 2b is stretched longer than the interval in the rotation direction.
So that at least one paddle 2b is always
It is located at a position facing the stop plate 6, and
Stirring with at least one paddle 2b and escape plate 6
The gap between the paddle 2 and the escape prevention plate 6 is stirred.
Can be closed except for the small gaps required for
You. As a result, at least one paddle 2b and the flow regulator
Between the stirring paddle 2 and the flow control plate 4 by the control plate 4
Of toner and developer in use
And is stably damped,
Stir in surely. In other words, this stirring paddle 2
Of the developer 3 passing through the gap between the
Is reliably prevented from being supplied from the toner supply device 5.
Ensure that the toner 31 is in contact with the developer 3 being used by the stirring paddle 2
After stirring, it can be sent to the paddle 7 side
You.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A stirrer according to an embodiment of the present invention will be described below with reference to FIGS. The stirrer according to this embodiment is one in which the present invention is applied to a toner stirrer of a laser printer, and as shown in FIG.
Developing device 10 arranged on the lower left side of photosensitive drum 200
0 has a stirring chamber 1 formed therein.

At the bottom of the stirring chamber 1, a pick-up paddle 7 for picking up the developer 3 as an object to be processed is disposed, and the stirring paddle 2 is disposed at the upper left of the pick-up paddle 7. Further, a developing mag roll 8 for electrostatically adsorbing the developer 3 picked up by the scraping paddle 7 is disposed above a right portion of the scraping paddle 7, and adheres to the developing mag roll 8 above and to the left of the developing mag roll 8. A blade 9 for limiting the amount of the developer 3 carried out to the developing area 10 is disposed. A flow regulating plate 4 for guiding the developer 3 removed from the developing mag roll 8 by the blade 9 is provided from the left side of the blade 9 to the upper side of the stirring paddle 2, and a toner supply device 5 is provided at the upper left of the stirring paddle 2. Be placed.

The developer 3 is composed of a toner 31 and a carrier 32 made of magnetic spheres stored in the developing chamber 1.
When the toner density decreases due to consumption of the toner 31, the toner 31 is supplied from the toner supply device 5 to recover the density. As shown in FIG. 1, FIG. 2 or FIG. 3, the stirring paddle 2 is provided with a pair of end plates 2a arranged at appropriate intervals on the center axis of rotation and at an appropriate interval in the rotational direction. And a plurality of (eight in this case) band-shaped paddles 2b connecting the both end plates 2a. As shown in FIGS. 1 and 2, in order to enhance the stirring effect of the stirring paddle 2, the chamber wall 11 of the stirring chamber 1 is moved downward from one side of the stirring paddle 2 to approach the stirring paddle 2. The rotation direction of the stirring paddle 2 is rotated in the direction approaching the chamber wall 11 on one lateral side from above (counterclockwise direction in the figure).

As shown in FIGS. 1 and 2, a flow preventing plate 6 extending along the outer periphery of the stirring paddle 2 is connected to the end of the flow regulating plate 4 on the stirring paddle 2 side. The length of the escape prevention plate 6 in the circumferential direction of the stirring paddle 2 is
And the toner 31 from between the paddles 2b is prevented from being missed stream, thereby expanded longer than the distance between the rotational direction of the at least Pas <br/> dollars 2b along the outer circumference of the mixing paddle 2.

The material of the flow preventing plate 6 is not particularly limited. However, in consideration of non-magnetic properties, excellent workability, sufficient rigidity, etc., The same phosphor bronze plate is used. In this stirring device, the toner 31 supplied from the toner supply device 5
As shown by an arrow a in FIG. 1, the stirring paddle 2 is inserted between the flow regulating plate 4 and two paddles 2b located near the plate.
If it is attempted to escape in the direction of rotation, it is blocked by the escape prevention plate 6 and pushed back inside the stirring paddle 2 as shown by the arrow b. As a result, while the toner 31 flows between the paddles 2b in a vortex shape, the paddles 2b
After the developer 3 that has been scooped up and the developer 3 that has fallen from the flow control plate 4 are surely stirred, the stirring paddle 2
Of the stirring paddle 2 in the direction of the rotation axis of the
Then, it flows to the opposite side and is further stirred.

As a result, it is possible to reliably prevent the toner 31 supplied from the toner supply device 5 from escaping to the developing mag roll 8 without being stirred with the developer 3 in the stirring chamber 1. Generation can be prevented, and deterioration of image or print quality due to raw toner can be prevented.

[0016]

As described above, according to the present invention, the flow control
The control plate 4 is extended longer than the interval in the rotation direction of the paddle 2b.
Flow control at least one paddle 2b
By a plate 4, the mixing paddle and the flow regulating plate is stopped-out developer Gase toner and in use to be departing flow from between, is pushed back into the mixing paddle in reliably using the developer
And the added toner can be stirred with a stirring paddle. In particular, in the present invention, the stirring paddle is
Is rotated from bottom to top along the escape plate.
And the weight between the stirring paddle and the flow control plate
The toner that is about to escape and the developer in use are scraped up.
The raw toner from between the stirring paddle and the flow control plate
Can be prevented more reliably.

Further, when the present invention is applied to a toner stirring device of an electrophotographic image forming apparatus, toner supplied from a toner supply device can be reliably stirred with a developer in a stirring chamber. A decrease in image quality or print quality due to generation of toner can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a sectional view of the embodiment.

FIG. 3 is a perspective view of the stirring paddle.

FIG. 4 is a sectional view of a conventional example.

FIG. 5 is an explanatory diagram of an object of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Stirring chamber 2 Stirring paddle 2b paddle 3 Developer 4 Flow control plate 6 Escape prevention plate 7 Raising paddle 8 Developing mag roll 9 Blade

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yuzuru Sugiura 35th Saho, Kato-gun, Hyogo (No address) Inside Fujitsu Peripheral Machinery Co., Ltd. Fujitsu Limited (72) Inventor Etsuo Aoyama 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited (56) References JP-A 1-135454 (JP, U) JP 2-149949 (JP, U)

Claims (1)

(57) [Claims] 1. A stirring paddle which is located above a pick-up paddle for supplying a developer to a developing mag roll and agitates replenished toner, and guides the developer removed from the developing mag roll by a blade to the stirring paddle. there, the end of its direction of rotation
A flow control plate extending toward a stirring paddle having a plurality of paddles , wherein a flow prevention plate is provided at an end of the flow control plate, and the flow prevention plate is provided on the outer periphery of the stirring paddle. How to rotate the paddle along
A stirrer characterized in that it is stretched for longer than the distance between the two directions .