JPH08106205A - Developer supplying device - Google Patents

Abstract

PURPOSE: To provide a developer supplying device in which the degradation of image density caused by the packing of developer is prevented and the problem such as soiling caused by residual developer at the time of exchanging a developer cartridge is eliminated by completely consuming all of the developer in the inside of the developer cartridge. CONSTITUTION: In this developer supplying device, the developer cartridge 4 housing the developer and a developer supplying member 11 in the inside and having an opening part (developer supply port) 9 in a developing chamber 3 is turnably attached to the developing device 2 and the developer in the inside of the developer cartridge 4 is supplied to the developing chamber 3 through the opening part 9 by the rotation of the developer supplying member 11. The device is provided with a mechanism for positioning the opening part 9 on an upper side than a horizontal surface L passing the center of the developer cartridge 4 when the developer cartridge 4 is completely filled with the developer (full state) and moving the aperture part 9 toward a lower side from the horizontal surface L as the developer in the inside of the developer cartridge 4 reduces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention supplies a developer to a developing device such as an electrophotographic copying machine which develops an electrostatic latent image formed on an electrostatic latent image carrier using an electrostatic charge developer. And a developer supply device for the same.

[0002]

2. Description of the Related Art Generally, in an electrostatic recording device such as an electrophotographic copying machine, an electrostatic latent image formed on a moving electrostatic latent image carrier is developed by a developing device to form a visible image. This visible image is transferred and fixed on the recording paper.

By the way, since the developer is consumed together with the development, it is necessary to replenish the developer to the developing device according to the consumption, and the replenishment development is performed before the developer in the developing device is completely consumed. The developer is replenished into the developing device from the developer replenishing container containing the developer.

As an example of a conventionally known developer supply container, a slot serving as a developer outlet is formed in a part of a peripheral wall of a cylindrical container main body for containing the supply developer, and the container main body is There is a device in which, after being attached to a developer replenishing portion of a developing device, the developer is rotated to drop and introduce the developer. Such a developer supply container secures a sufficient amount of developer and also supplies a developer by utilizing natural fall, so that a large capacity is secured and the shape thereof is vertically long.

Therefore, it is difficult to use the developing device equipped with the above-mentioned developer supply container in a small-sized, especially thin copying machine or the like. For this reason, the developer must be replenished frequently. There was an inconvenience that it took time and effort.

In order to solve the above-mentioned inconvenience, there has been proposed a developing device in which a developer storage unit for supplying the developer from the horizontal side of the developing unit is provided behind the developing unit accommodating the developer carrying member. (In Japanese Patent Application No. 61-2175). According to this developing device, the overall height can be significantly reduced, and the developing device can be easily installed in a small and thin copying machine.

[0007]

By the way, in the above-mentioned developing device for supplying the developer from the horizontal direction, a blade member is provided at the tip in order to move the developer horizontally from the developer storage section to the developing section. The developer supply member is used.

However, even when the above-mentioned developer supply member is used, a small amount of developer remains in the developer supply container, and the residual developer spills out when the developer supply container is exchanged, causing a loss of human body or clothes. And so on.

Further, in order to prevent the residual developer from remaining, if the developer outlet is tilted downward from the horizontal direction and the developer is supplied, the development is performed when an image having a low image ratio is copied. Since the amount of developer consumed in the device is small, the developer supply amount becomes excessive by the developer supply member, especially immediately after the developer supply container is replaced, and packing of the developer occurs, causing developer circulation flow. However, there is a problem in that the density of the copy deteriorates as a result.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent a decrease in image density due to packing of a developer and to consume all the developer in the developer cartridge for development. It is an object of the present invention to provide a developer supply device capable of solving problems such as contamination due to residual developer when the developer cartridge is replaced.

[0011]

In order to achieve the above object, the present invention is to provide a developer containing a developer and a developer supply member therein and having a developer supply port opening to a developing chamber. Attach the cartridge rotatably to the developing device,
In a developer supply device that supplies the developer in the developer cartridge to the developing chamber through the developer supply port by the rotation of the developer supply member, the developer is completely filled in the developer cartridge. The developer supply port is positioned above a horizontal plane passing through the center of the developer cartridge, and the developer supply port is moved below the horizontal plane as the developer in the developer cartridge decreases. The feature is that a mechanism is provided.

[0012]

According to the present invention, when the developer cartridge is completely filled with the developer, the developer supply port is located above the horizontal plane passing through the center of the developer cartridge. Packing due to excessive supply of developer to the developing chamber is prevented, and the problem of reduction in image density due to packing is solved.

Further, according to the present invention, as the amount of the developer in the developer cartridge decreases, the developer supply port is moved downward from the horizontal plane, so that no developer remains in the developer cartridge. It can be consumed, and problems such as contamination due to residual developer when replacing the developer cartridge can be solved.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1> FIG. 1 is a schematic side sectional view showing the basic structure of a developer supply apparatus according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 1 is an electrostatic latent image carrier provided in the main body of a copying machine or the like, which is rotationally driven at a constant speed in the arrow direction by a drive system (not shown). A developing device 2 equipped with the developer supply device according to the present invention is installed near the electrostatic latent image carrier 1.

The developing device 2 includes the electrostatic latent image carrier 1
Surrounded by a housing 5 composed of a laterally elongated molded product of ABS resin material or the like, which is composed of a developing chamber 3 having an open side and a substantially cylindrical developer cartridge 4 which is integrally connected to the rear of the developing chamber 3. Has been.

In the developing chamber 3, a developing sleeve 6 which rotates in close proximity to the electrostatic latent image carrier 1 with a predetermined gap therebetween,
A developing blade 7 pressed against the developing sleeve 6 and a stirring member 10 for stirring and transporting the developer in the developing chamber 3 are housed.

The developing sleeve 6 is made of a stainless plate having a thickness of about 1 mm, and its surface is blasted. A magnet roller 8 is housed inside the developing sleeve 6, and the magnet roller 8 conveys the developer. The developing sleeve 6 is applied with a developing bias voltage in which a high frequency alternating voltage having a frequency of 2.2 KHz and a voltage of 1.4 KV is superimposed on a DC voltage of -300V.

The developing blade 7 pressed against the developing sleeve 6 is a blade made of an elastic material such as silicon rubber having a thickness of about 1 mm, which regulates the layer thickness of the developer on the developing sleeve 6. At the same time, charge is applied.

The agitating member 10 is made of stainless steel and is bent into a crank shape, and is rotated in the direction of the arrow to convey the developer to the developing sleeve 6.

On the other hand, the developing chamber 3 and the developer cartridge 4 are communicated with each other at an opening 9 having a width of 10 mm, and the developer cartridge 4 is formed into a cylindrical shape having a diameter of 5 cm. A developer supply member 11 is rotatably supported between the centers of the side frames.

The developer supply member 11 is composed of a rotary shaft made of stainless steel whose both ends are bent substantially in a crank shape and a blade member 12, and the blade member 12 moves along the inner wall of the developer cartridge 4. To do.

The developer is supplied to the developing chamber 3 by the rotation of the developer supplying member 11 provided in the developer cartridge 4, and is sent to the developing sleeve 6 by the agitating member 10. Then, the developer sent to the developing sleeve 6 is attracted to the developing sleeve 6, and the developing blade 7 forms a uniform thin layer of the developer on the developing sleeve 6.

The thin layer of the developer formed on the surface of the developing sleeve 6 flies to the electrostatic latent image carrier 1 on the surface of which the electrostatic latent image is formed by the exposure process, whereby the electrostatic latent image is formed. The electrostatic latent image on the carrier 1 is developed.

Next, the present invention will be described in detail with reference to FIGS.

FIG. 2 is a perspective view of the developer cartridge 4, in which G1 is the developer supply member 11.
The gear G1 is a gear for driving the developer supply member 11 by the driving force transmitted from a drive source (not shown).
Is rotated in the direction of arrow J. Further, G8 is a gear for rotating the developer cartridge 4, and this gear G8 is interlocked by mechanical means such as a combination of the gear G1 and a gear train G2 to G7 shown in FIG. When the number of rotations of the gear G1 increases as the number of copies increases, the gear G8 rotates to rotate the developer cartridge 4 in the direction of arrow I in the figure.

By the way, in an experiment conducted by the inventors, about 250 g of the developer was filled in the developer cartridge 4, and the gear G1 was rotated once for each copying operation.
As an example, the gear trains G2 to G7 are set as shown in FIG. 4 so that the gear G8 rotates 1.4 revolutions per 0000 revolutions.

That is, the rotation of the gear G1 is transmitted to the gear G8 via the gears G2 to G7 and the belt B1.
To G8 gear ratio G1: G2: G3: G4: G5: G6:
G7: G8 is set to 1: 10: 1: 20: 1: 10: 1: 7. Therefore, 20000 rotations of the gear G1 is reduced to 2000 rotations and transmitted to the gears G2 and G3.
The 2000 revolutions of the gears G2 and G3 are reduced to 100 revolutions and transmitted to the gears G4 and G5.
The rotation is reduced to 10 rotations and transmitted to the gears G6 and G7, and the 10 rotations of the gears G6 and G7 is reduced to 1.4 rotations and transmitted to the gear G8.

Then, when the copying operation was continuously carried out with the amount of developer consumed per copy being 0.05 g, as shown in FIG. 3A, the developer was initially (when full). A straight line connecting the center of the opening 9 of the cartridge 4 and the center of the developer cartridge 4 is θ = 3 with respect to the horizontal plane L.
0 ° upward (the remaining amount of developer at this time was about 250
On the other hand, in 5000 sheets, as shown in FIG. 3C, θ = 25 ° downward (the remaining amount of the developer at this time is about 10 g), and the density of the copy image does not decrease, and All the developer in the cartridge 4 was consumed (referred to as Experiment 1). It should be noted that FIG. 3B shows a state during intermediate use in which the opening 9 coincides with the horizontal plane L. At this time, the remaining amount of the developer was about 150 g.

On the other hand, when the opening 9 is fixed on the horizontal plane L (see FIG. 3B) and the same number of sheets are continuously copied with the same developer consumption setting, a copy image is obtained after about 500 sheets. The density was reduced, and the developer remained in the developer cartridge 4 (Experiment 2). FIG. 5 shows the change in image density (reflection density) with respect to the number of copies in Experiment 1 and Experiment 2, and FIG. 6 shows the change in the remaining amount of developer with respect to the number of copies in Experiment 1 and Experiment 2, respectively.

In Experiments 1 and 2, the amount of developer discharged from the developer cartridge 4 into the developing chamber 3 per one rotation of the developer supply member 11 and the density of the developer in the developing chamber 3 (Developer chamber developer amount / Developer chamber volume [g / c
c]) was measured. The results are shown in FIGS. 7 and 8.

According to FIG. 7, when the present invention is adopted (Experiment 1), compared with the case where it is not adopted (Experiment 2), the discharge amount of the developer is small in the initial stage, and the discharge amount is increased as the number of copies increases. Changes slowly. This indicates that the developer is being stably supplied from the developer cartridge 4 to the developing chamber 3.

Further, according to FIG. 8, when the present invention is adopted (Experiment 1), the developer density in the developing chamber 3 is lower in the initial stage than when it is not adopted (Experiment 2), and the developer density is It is stable even when the number of copies increases.

As is clear from the above results, according to the present invention, the packing of the developer due to the excessive supply of the developer from the developer cartridge 4 to the developing chamber 3 is prevented, and the image density is lowered due to the packing. Is eliminated.

Further, according to the present invention, as the developer in the developer cartridge 4 decreases, the developer supply port 9 is moved downward from the horizontal plane L, so that the development in the developer cartridge 4 is performed. It is possible to consume the entire amount of the developer, and the problem such as contamination due to the residual developer when the developer cartridge 4 is replaced is solved.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 9 is a cross-sectional view for explaining the operation of the developer supply device according to the second embodiment. In this figure, the same elements as those shown in FIG. 3 are designated by the same reference numerals. The description is omitted.

In FIG. 9, reference numeral 40 denotes a remaining amount sensor using a piezo element, and the remaining amount sensor 40 detects the remaining amount of the developer in the developer cartridge 4. Further, the opening 9 of the developer cartridge 4 is provided with a shutter 41 which moves up and down by a solenoid switch (not shown).

Thus, when the developer in the developer cartridge 4 is initially full as shown in FIG. 9A, the solenoid switch is in the OFF state,
The shutter 41 is located below the opening 9 as shown.

When the developer is consumed and the amount of the developer in the developer cartridge 4 becomes less than a predetermined amount as shown in FIG. 9B, a signal is transmitted and a solenoid switch (not shown) is turned on. . Then, the shutter 41 moves to the upper portion of the opening 9 as shown in the figure, and the opening portion of the opening 9 that has been in the upper portion until now moves to the lower portion, so that packing occurs as in the first embodiment. It is possible to supply a stable developer.

[0041]

As is clear from the above description, according to the present invention, when the developer cartridge is completely filled with the developer, the developer supply port is located above the horizontal plane passing through the center of the developer cartridge. Since it is also positioned above,
There is an effect that packing due to excessive supply of developer from the developer cartridge to the developing chamber is prevented, and the problem of reduction in image density due to packing is solved.

Further, according to the present invention, as the amount of the developer in the developer cartridge decreases, the developer supply port is moved downward from the horizontal plane, so that no developer remains in the developer cartridge. It is possible to consume, and it is possible to solve the problem that the problem such as the contamination due to the residual developer when the developer cartridge is replaced is solved.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing a basic configuration of a developer supply device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a developer cartridge according to the first exemplary embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating the operation of the developer supply device according to the second embodiment of the invention.

FIG. 4 is a diagram showing a configuration example of a gear train.

FIG. 5 is a diagram showing a change in image density (reflection density) with respect to the number of copies.

FIG. 6 is a diagram showing changes in the remaining amount of developer with respect to the number of copies.

FIG. 7 is a diagram showing a change in developer discharge amount with respect to the number of copies.

FIG. 8 is a diagram showing a change in developer density with respect to the number of copies.

FIG. 9 is a sectional view illustrating the operation of the developer supply device according to the second embodiment of the present invention.

[Explanation of symbols]

 2 developing device 3 developing chamber 4 developer cartridge 8 magnet 9 opening (developer supply port) 11 developer supply member G1 to G8 gear B1 belt 40 remaining amount sensor 41 shutter L horizontal plane

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Matsumoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (1)

[Claims] 1. A developer cartridge containing a developer and a developer supply member inside and having a developer supply port opening to a developing chamber is rotatably mounted on a developing device,
In a developer supply device that supplies the developer in the developer cartridge to the developing chamber through the developer supply port by the rotation of the developer supply member, the developer is completely filled in the developer cartridge. The developer supply port is positioned above a horizontal plane passing through the center of the developer cartridge, and the developer supply port is moved below the horizontal plane as the developer in the developer cartridge decreases. A developer supply device having a mechanism.