JPH0667539A - Toner feeding device - Google Patents

Abstract

PURPOSE:To prevent toner which is not electrified from remaining in a developing device by disintegrating clots of toner included in the carrying toner. CONSTITUTION:The device is constituted so that the toner which is dropped in from a hopper part for toner reception 3 is carried toward the other end of a housing 1 by a spring spiral for carrying 5 which is rotated and driven in one direction and the toner is ejected from a toner supplying opening 4, the toner clots being carried whose particles are bound by weak binding force are disintegrated by the impact force of the extracting oscillation in the thrust direction when a leading part 5a of the rotating spiral 5 is passed by a projection provided on the wall surface on the other edge 13 of the housing 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for supplying toner to a developing device in an electrophotographic apparatus such as an electronic copying machine or a printer, and more particularly to a toner supplying device for preventing discharge of toner lumps caused by defective stirring. It is a thing.

[0002]

2. Description of the Related Art Conventionally, in an electronic copying machine, a toner supplying device for supplying the toner of the toner cartridge to the developing device is provided between a replenishing toner cartridge arranged in the upper part of the machine and a developing device arranged in the lower part. When the toner control sensor provided in the developing device detects that the toner amount in the developing device is insufficient, the toner supply device is driven and controlled by the detection signal, and the developing device is replenished with an appropriate amount of toner. Is configured to.

In the toner supply device used for the above purpose, a toner receiving hopper is provided on one end side of a horizontally long housing, and the hopper is made to face the replenishing port of the toner cartridge. is there. A transport spiral is loaded in the housing along the central axis direction. When a signal is output from the toner control sensor, the transport spiral is rotationally driven by the motor, and the toner replenished from the toner cartridge is simultaneously transported to the other end side of the housing while being agitated by the spiral that rotates in one direction. The toner is replenished to the developing device from the toner supply port having a long hole provided on the side surface of the housing along the axial direction in accordance with the carrying operation.

[0004]

By the way, the toner is originally provided with the fluidity necessary for transportation, and for example, under the condition of the temperature of 20 ° C. and the humidity of 45%, the toner particles never stick to each other. Instead, the toner is dropped and discharged from the toner supply port by an appropriate amount at the time of transportation, but under high humidity conditions, powder bonding due to adhesion occurs between the particles, and a toner lump is likely to be formed. This toner lump is hardly pulverized by the stirring operation by the rotation of the spiral, and falls from the toner supply port while maintaining the lump shape, so that the toner is not uniformly supplied to the developing device.

When the toner agglomerates with poor stirring are dropped into the developing device in this manner, they are not crushed by the agitating operation in the developing device and are conveyed to the surface of the photosensitive drum in the uncharged state as they are. Therefore, there is a problem that the toner mass adheres to the drum surface as uncharged toner and appears on the copy object. Further, when the toner lump falls on the toner control sensor in the developing device, the sensor detects the toner lump, and erroneously determines the detected value as a normal value and outputs a control signal, so that the toner amount is reduced. Toner replenishment is interrupted when the amount does not reach an appropriate amount, which may lead to inconvenience that uneven density occurs on an object to be copied.

The present invention has been made in order to solve such a problem. In the toner supplying device, the toner lump is crushed before it falls into the developing device, and the uncharged toner lump is generated in the developing device. The purpose is to reliably prevent the remaining.

[0007]

In order to achieve the above object, the present invention has a horizontally long housing which is installed substantially horizontally, and a toner receiving hopper portion is arranged on one end side of the housing. , While forming a long hole-shaped toner supply port along the housing center axis on the side surface of the housing,
A conveying spring spiral having elasticity in the thrust direction along the central axis direction is loaded in the housing with its tip always in contact with the side wall surface of the other end of the housing. By the rotational drive in the direction, the toner supplied from the hopper is conveyed toward the other end of the housing, and the toner is discharged from the toner supply port.
Further, a stepped portion for vibrating the transport spring spiral in the thrust direction is formed at a single or a plurality of positions on the revolving portion in contact with the tip end portion of the transport spring spiral on the other end side wall surface of the housing.

[0008]

With this structure, when the transfer spring spiral is driven to rotate in one direction, it expands and contracts in the thrust direction every time its tip passes through the step formed on the side wall of the other end of the housing. The impact force due to the vibration spreads over the entire conveying spring spiral, and the weak toner particles are crushed by the weak coupling force during the conveyance. As a result, even if toner particles are present in the toner put into the housing, the toner particles are pulverized by the impact in the thrust direction generated on the transport spring spiral, and air is generated between the toner particles due to vibration. Good flowability of the toner is imparted by being fed.

[0009]

1 to 3 show a toner supply device of an electrophotographic apparatus embodying the present invention. In these figures,
Reference numeral 1 denotes a cylindrical shaft-shaped housing made of synthetic resin. The housing 1 has a length in a horizontal direction perpendicular to the short shaft portion 1a from a short shaft portion 1a in the vertical direction through an arcuate bending shaft portion 1b. The shaft portion 1c has a horizontally long L-shape extending and these short shaft portions 1c
A series of toner transport paths 2 are formed in a, the bending shaft portion 1b, and the long shaft portion 1c.

A toner receiving hopper portion 3 communicating with the toner conveying path 2 is provided on the upper surface of one end of the housing minor shaft portion 1a, and a side surface portion of the housing major shaft portion 1c has a length along the center axis of the housing. A hole-shaped toner supply port 4 is provided. The toner supply port 4 is gradually widened from one end side to the other end side in order to evenly distribute the discharge of the toner continuously fed from the hopper section 3 to the toner conveying path 2. Is formed in. The L-shape of the housing 1 is for the purpose of effectively utilizing the space inside the body, and the design can be changed to a linear shape or any other mode.

Reference numeral 5 denotes a conveying spring spiral. The spiral 5 is formed into a coil spring shape having elasticity in the thrust direction, and is bent in an L-shape along the central axis direction of the housing 1. It is rotatably loaded. In this loaded state, the spiral 5 has a drive unit 6 whose base end faces the side wall surface at one end in the housing 1.
When the drive unit 6 is driven in response to a control signal from a toner control sensor (not shown), the toner is conveyed in one direction, that is, the direction in which toner is conveyed from one end side to the other end side of the conveyance path 2. It is driven to rotate.

As shown in FIG. 4, the drive unit 6 includes a motor 8 and a gear reduction mechanism 9, and the final stage gear shaft of the reduction mechanism 9 is connected to the base end of the spiral 5 as the output shaft 7. It is something. As the deceleration mechanism 9, a well-known means such as one using a timing belt other than a gear type can be appropriately selected.

FIG. 5 shows the arrangement of the toner supply device 10 in the body of the electrophotographic apparatus.
0 is interposed between the detachable and replaceable toner cartridge 11 arranged in the upper part and the developing device 12 arranged in the lower part in the body of the electrophotographic apparatus, and the housing 1 is fixed to the upper surface of the developing device 12. It is installed by screws 13 (see FIG. 1) and detachably fixed so that it is installed almost horizontally. In this installed state, the toner supply device 10 has the hopper portion 3 at the discharge port 11a of the toner cartridge 11.
Of the toner supply port 4 is continuous, and the toner supply port 4 faces the toner supply port 12a of the developing device 12.

The toner control sensor described above is a magnetic permeability sensor for detecting the magnetic permeability of the developer to detect T / D of the developer (where T is the toner amount and D is the developer amount).
The T / D of the developer in the stirring path is detected by being arranged at an appropriate position on the bottom of the stirring path formed below the developing device supply port 12a.

Now, when it is necessary to replenish toner in the developing device 12, the toner control sensor causes the motor 8 to move.
A control signal is output to, and the spiral 5 is rotationally driven in one direction by the activation of the motor 8. In addition, spiral 5
Is formed in the shape of a coil spring, it is elastically deformed along the L-shaped bent toner conveying path 2 and smoothly rotates over its entire length while maintaining its shape. By the rotational driving of the spiral 5, the toner dropped and supplied from the toner cartridge 12 through the hopper portion 3 to the transport path 2 is transported from one end side to the other end side of the transport path 2. During this conveyance, the toner is discharged by a proper amount from the toner supply port 4 while being stirred by the spiral 5, and the developing device 12
It is dropped into the stirring path of. The toner charged into the stirring path of the developing device 12 is in an uncharged state, but while being stirred with the developer, it is mixed with a carrier to be charged with, for example, a negative polarity, and electrodeposited on the surface of a photosensitive drum (not shown). To be done.

The above construction is the same as the conventional one, but in the present embodiment, the conveying spring spiral 5 of the toner supply device is used.
It is largely different in that it is provided with a structure for vibrating in the thrust direction when it is rotationally driven. That is, as shown in FIG. 6, the spiral 5 rotatably loaded in the transport path 2 is
The tip portion 5a is configured so as to be constantly in contact with the other end side wall surface of the housing 1, that is, the wall surface 13 facing the spiral 5 at the end portion in the transport direction, and the contact portion of the wall surface 13 is in contact with the tip portion 5a of the spiral 5. The stepped portion 14b is formed at a plurality of portions, so that each time the tip 5a of the spiral 5 passes through the stepped portion 14b during rotational driving, it expands and contracts in the thrust direction.

7 to 9 show the other end side wall surface 1 of the housing 1.
3 shows an example of the stepped portion 14b formed in FIG. 3, and in the one shown in this figure, it has a narrow fan-shaped front view and an inclined surface 14a rising from the front side in the spiral rotation direction toward the same rotation direction, The ridges 14 each having a right-angled triangular cross section, which have upright surfaces 14b that stand substantially vertically from the end of the inclined surface 14a in the direction of rotation, are radially formed at substantially regular intervals, and the upright surfaces 14b of the respective ridges 14 are stepped. It is what The ridge 14 having the step portion 14b is integrally formed with the housing wall surface 13, but it is also possible to manufacture another component forming the ridge 14 and fix the ridge 14 to the wall surface 13.

8 and 9 show the other end side wall surface 1 of the housing 1.
3 is an enlarged cross-sectional view of the main part of FIG. 3, and FIG.
FIG. 9 shows a state in which "a" rides on the ridge 14, and FIG. 9 shows a state in which the spiral tip portion 5a crosses the stepped portion 14b. As shown in FIG. 8, when the spiral 5 is rotationally driven in one direction at a constant speed, the tip end 5a of the spiral 5 interferes with the inclined surface 14a of the ridge 14 to force the spiral 5 to move in the thrust direction. Compresses and shrinks. Next, as shown in FIG. 9, the spiral tip portion 5a is inclined to the inclined surface 14a.
When it reaches the upright step 14b after passing through, the spiral 5 abruptly expands by the elastic restoring force and collides with the other end side wall surface 13. The vibration generated by the impact due to the collision with the wall surface 13 is propagated to the entire spiral 5, and if there is a toner lump in the conveyed toner, the toner lump that is interparticle-bonded with a weak binding force is It is surely crushed by the vibration impact force. Therefore, there is no fear that toner clumps will be replenished to the developing device 12 as they are, and the charging process of the toner by stirring the developing device 12 is performed without any trouble, and various inconveniences due to the remaining uncharged toner are eliminated. .

Returning to FIG. 8, the height of the upright surface 14b of the ridge 14, that is, the drop H of the stepped portion 14b is determined in consideration of the toner particle diameter, but normally 1 to 3 mm is appropriate. Conceivable. Further, it is appropriate that the number of the protrusions 14 forming the step portion 14b is about 10 to 20 as in the illustrated example, but in this case, when the spiral tip portion 5a passes through the step portion 14b, the adjacent protrusions are not formed. Spiral tip 5 on Article 14
Since the portion in the vicinity of "a" contacts and does not reach the wall surface 13, there is a restriction on the magnitude of the impact force. When it is necessary to increase the impact force in particular, the number of the ridges 14 is reduced to a single to four or so, and the extension of the spiral 5 after the spiral tip 5a passes through the step 14b ensures that the tip 5a is securely formed. It is good to reach the wall surface 13. Furthermore, the aspect of the wall surface 13 in which the step portion 14b is formed is the protrusion 1
The number of modifications is not limited to four, and various modifications such as sawtooth shapes arranged radially can be adopted.

[0020]

As described above, according to the present invention, a single portion of the revolving portion that comes into contact with the tip of the conveying spring spiral on the other end side wall surface of the housing, which is the terminal end of the toner conveying path starting from the toner receiving hopper portion. By forming a stepped portion for vibrating the spiral in the thrust direction at one or more places, expansion / contraction vibration in the thrust direction occurs each time the tip of the spiral that is rotationally driven in one direction passes through the stepped portion. The impact force due to the vibration spreads over the entire spiral, and the toner lumps that are bonded between the particles with a weak bonding force are crushed, and sufficient air is sent between the toner particles to form the toner lumps. Since it hinders and improves the fluidity, even if toner particles are present in the toner that has been put into the housing, the toner particles are generated by the vibration of the spiral. Securely be powdered by a thrust direction of the shock generated, it can be replenished good toner with excellent fluidity to the developing unit.

Therefore, for example, in an electrophotographic apparatus using a two-component developer, it is possible to eliminate the generation of uncharged toner due to the presence of toner lumps at the time of stirring and mixing with the developer in the developing device, and to change the toner concentration. Can be kept constant.

Further, the step portion can be formed on the end wall surface of the housing at the same time when the housing is manufactured.
Since its structure is simple, it has an excellent effect that it can be manufactured at a relatively low cost.

[Brief description of drawings]

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

FIG. 2 is a rear view in which a part thereof is cut away.

FIG. 3 is a bottom view thereof.

FIG. 4 is an end view taken along the section line AA in FIG.

FIG. 5 is a front view schematically showing the arrangement around the toner supply device.

FIG. 6 is a partially cutaway enlarged view showing the other end portion of the housing.

FIG. 7 is a front view showing an example of a step portion formed on the other side wall surface of the housing.

FIG. 8 is an enlarged cross-sectional view of an A ′ portion in FIG. 6, showing a state in which a spiral tip portion has climbed up on a ridge.

FIG. 9 is an enlarged cross-sectional view of an essential part showing a state in which a spiral tip portion has passed a step portion.

[Explanation of symbols]

 1 Housing 3 Toner Receiving Hopper 4 Toner Supply Port 5 Conveying Spring Spiral 5a Spiral Tip 13 Other Side Wall Side of Housing 14b Step

Claims (1)

[Claims] 1. A horizontally long housing that is installed substantially horizontally, a toner receiving hopper is disposed at one end of the housing, and a toner having a long hole along the center axis of the housing is provided on a side surface of the housing. While forming the supply port,
A conveying spring spiral having elasticity in the thrust direction along the central axis direction is loaded in the housing with its tip always in contact with the side wall surface of the other end of the housing. Is a toner supply device configured to discharge toner from the toner supply port while conveying the toner supplied from the hopper toward the other end side of the housing by rotational drive to the housing. Toner supply, characterized in that a step portion for vibrating the transport spring spiral in the thrust direction is formed at a single or at a plurality of circumferential portions in contact with the tip of the transport spring spiral on the other end side wall surface. apparatus.