JP2002268343A - Developing device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device and a process cartridge by which stable toner feeding can be carried out, even when small-sized particle toner is utilized. SOLUTION: In the device, one end side film member 40 is provided on one end part of an agitator 11 of a toner storing part 7, and the other end side film member 41 is provided on the other end part. In this case, the one-end film member 40 is longer than the other end film member 41, and an auxiliary film member 41a, which is shorter than the one end film member 40, is provided so as to be superpose on it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for use in an image forming apparatus such as a copying machine, a facsimile, a printer, etc., and more particularly, to a developing device formed on an image carrier using a two-component developer composed of toner and magnetic particles. And a developing device for developing the latent image.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 9-197833
Japanese Patent Application Laid-Open Publication No. H11-163873 discloses a developing device of a system in which a two-component developer composed of a mixture of a toner and a carrier is carried on a developer carrier and applied to the surface of the latent image carrier to develop a latent image on the surface of the latent image carrier. A developer accommodating section for accommodating the developer in the developing sleeve, a toner accommodating section connected to the developer accommodating section through a toner replenishing opening through a toner replenishing opening, and toner replenishing of the toner in the toner accommodating section. It has a toner conveying member that conveys the toner in the opening direction, and a developer stagnation portion provided in the vicinity of the developer replenishment portion side of the toner replenishment opening portion. When the developer is in a volume amount corresponding to the toner concentration, the developer sufficiently enters and stays there and the toner supply opening is closed by the staying developer, and the developer corresponds to a toner amount less than an appropriate range. When it decreases to the state There is no retention of residual amount decreases and or the developer of the image, toners containing portion is known a technique of in a relationship level position to contact via the toner supply port portion to the developer accommodating portion.

In the developing device described in Japanese Patent Application Laid-Open No. 9-197833, when the toner concentration of the developer is within an appropriate range, the developing device in which the toner replenishing opening for replenishing the toner with respect to the developer retaining portion is retained. Closed by the agent and no toner is replenished. On the other hand, when the toner is consumed by the developing operation, the developer remaining in the toner replenishing opening is lost, and the toner enters and attempts to return to a predetermined toner concentration. As a result, the toner concentration (defined by the weight ratio of the magnetic particles and the toner) of the developer including the toner and the magnetic particles (carrier) falls within a certain range.

[0004] Conventionally, the graininess of an image has been improved by reducing the particle size of the toner (normal toner particle size is about 9 to 10 µm, whereas small toner size is about 6 to 8 µm). It has been found that high image quality can be achieved by improving dot reproducibility. However, when the particle size of the toner is reduced, the fluidity is deteriorated, so that the toner is difficult to be conveyed, and a problem of uneven image density occurs.

FIG. 5 shows an agitator shape before the particle size is reduced. The agitator 111 has seal members 401 and 411.
Are attached, one seal member 401 is long and the other seal member 411 is short. In the new state, the developer and the toner are sealed at positions X and Y by pull-out seals 370 and 380, respectively. The agitator 111 is arranged as shown in FIG.

In use, the pull-out seal 380 on the developer side is used.
Is removed, and then the seal 370 on the toner storage unit side is removed. By doing so, the toner is supplied after the developer is supplied to the developing sleeve 120, so that the toner density is appropriately controlled. Even if the seal 370 on the toner storage section side is removed first, the long mylar 401 blocks the toner supply port outlet, thereby preventing toner from being supplied to the developing sleeve 120. In other words, the long seal member 401 serves to block the toner outlet when new, and the short seal member 411 supplies toner to the toner supply path.

[0007]

However, according to the above-mentioned technology, when the particle size of the toner is reduced, the toner supply amount is reduced due to deterioration of the fluidity of the toner. Suppose a short sealing member 411
Even if the thickness of the toner is increased, the supply amount increases, but when the remaining amount of toner becomes small, the stiffness of the short seal member 411 becomes too strong, so that the toner is supplied too much and the toner concentration becomes too high. Occurs.

Accordingly, an object of the present invention is to provide a developing device and a process cartridge capable of supplying a stable toner even when a small particle size toner is used.

[0009]

According to a first aspect of the present invention, there is provided a developer carrying member having a magnetic field generating means therein for carrying and transporting a two-component developer containing a toner and a magnetic carrier; A first regulating member for regulating the amount of the developer carried and conveyed by the developer carrier, a developer accommodating portion for accommodating the developer scraped by the first regulating member, and a first regulating member A second regulating member disposed on the upstream side of the developer carrying member in the transport direction of the developer, and a toner which is adjacent to the developer accommodating portion and which supplies toner to the developer carrying member by an agitator which is driven to rotate. And a container in which the developer blocked by the first regulating member forms a circulating portion of the developer upstream of the second regulating member in the developer conveying direction. At one end of the agitator, one end side film member is provided, The other end side film member is provided at the end, the one end side film member is longer than the other end side film member, and the auxiliary film member shorter than the one end side film member overlaps the one end side film member. It is characterized by being provided.

According to the first aspect of the present invention, an auxiliary seal shorter than the one-side film member is provided so as to overlap the one-end-side seal of the agitator.
Even when a small particle size toner is used, stable toner supply can be performed.

According to a second aspect of the present invention, in the first aspect, the auxiliary film member is the same part as the other end side film member.

According to the second aspect of the present invention, the first aspect is provided.
In addition to the same effects as the invention described in (1), the film member on the other end and the auxiliary seal are made the same part, and by sharing these parts, it is possible to prevent errors during assembly and simplify parts management. become.

[0013] The invention according to claim 3 is the invention according to claim 1 or 2.
In the invention described in (1), the auxiliary film member is provided on the one end side film member on the downstream side in the rotation direction of the agitator.

[0014] According to the third aspect of the present invention, the first aspect is provided.
In addition, the same operation and effect as those of the invention described in 2 can be obtained, and the toner can be more reliably supplied by providing the auxiliary seal downstream of the one end film member in the rotation direction of the agitator.

According to a fourth aspect of the present invention, at least one means selected from an image carrier, a charging means, and a cleaning means, and a developing device are integrally supported, and are detachable from the image forming apparatus main body. In the process cartridge, the developing device is a developing unit according to any one of claims 1 to 3.

[0016] According to the fourth aspect of the present invention, the first aspect is provided.
According to the third aspect of the invention, it is possible to provide the same operation and effect as the invention described in any one of the first to third aspects, and to provide high image quality without image density unevenness.

[0017]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view schematically showing a process cartridge of a copying machine according to the present invention. The developing device 2 disposed on the side of the photosensitive drum 1 serving as an image carrier includes a developing housing 3, a developing sleeve 4 as a developer carrier, and developer accommodating portions 5a and 5a.
b. It mainly comprises a first doctor blade 6 as a developer regulating member.

Inside the developing housing 3 having an opening on the photosensitive drum 1 side, a toner hopper 8 is formed as a toner container for accommodating the toner 7, and is adjacent to the toner hopper 8 and closer to the photosensitive drum 1 side. Is provided with a developer accommodating portion 5a for accommodating a two-component developer 9 composed of a toner 7 and a carrier that is a magnetic particle.

Inside the toner hopper 8, there is provided a toner agitator 11 as toner supply means which is rotated by a driving means (not shown). The toner agitator 11 rotates in the direction of the arrow to send out the toner 7 in the toner hopper 8 while stirring it toward the toner supply opening 10.

In the space between the photosensitive drum 1 and the toner hopper 8, a developing sleeve 4 is provided. The developing sleeve 4, which is rotationally driven by a driving unit (not shown) in the direction of the arrow in the drawing, has a magnet 4a as a magnetic field generating unit, which is disposed inside the developing sleeve 4 at a fixed position relative to the developing device 2. .

A first doctor blade (first regulating member) 6 is integrally attached to a side of the developer accommodating portion 5a opposite to the side attached to the developing housing 3. The first doctor blade 6 is arranged with a certain gap kept between its tip and the outer peripheral surface of the developing sleeve 4. A second developer regulating member 12 as a second regulating member is provided in a portion of the developer containing section 5a located near the toner supply port 10.

With the above configuration, the toner 7 sent out from the inside of the toner hopper 8 by the toner agitator 11 is carried on the developing sleeve 4 through the toner supply opening 10, and the toner 7 carried on the developing sleeve 4
Is supplied to the developer 9 and carried to the developer accommodating portion 5a. The developer 9 in the developer accommodating portion 5a is carried on the developing sleeve 4 and transported to a position facing the outer peripheral surface of the photosensitive drum 1, and only the toner 17 is transferred to the photosensitive drum 1.
The toner image is formed on the photosensitive drum 1 by electrostatically coupling with the electrostatic latent image formed thereon.

The developer 9 circling around the developing sleeve 4
When the developer passes through the developer accommodating portion 5a, a brake is applied by the developer remaining inside the developer storage portion 5a, so that the transport speed is reduced. As a result, the developer 9 on the developing sleeve 4 near the second developer regulating member 12 is caused. Layer thickness increases. When the toner concentration increases, the frictional force between the developers 9 decreases and the transport speed decreases, so that the layer thickness further increases and the second developer regulating member 12 prevents the developer from advancing.

When such a state is reached, the opening 14 is blocked by the stagnant developer stagnating in the circulating portion 13 halted from moving forward, and thus stops taking in the toner. Conversely, when the toner concentration decreases, the frictional force between the developers increases, and the stagnant developer in the circulation section 13 is taken into the developer accommodating section 5a. The toner comes in contact with the developer that is rotating with the toner. With the above operation, the toner concentration of the developer can be automatically controlled.

Around the photosensitive drum 1, in addition to the developing device 2, a charging device (charging means) 36, a cleaning device (cleaning means) 35, a waste toner storage case 3
1, a waste toner 32, a waste toner collecting roller 33 for feeding waste toner cleaned by the cleaning device 35 to a waste toner storage case, and a drum case 34 for holding the photosensitive drum 1, the charging device 36 and the cleaning device 35 are provided. ing. The process cartridge 43 is configured by integrating the drum cases and the developing device 2 described above. The process cartridge 43 is detachable from the copier main body.

The process cartridge 43 is configured to be roughly divided into three as shown in FIG. The photoreceptor unit, the developing unit, and the toner storage unit are shown from the left side of the figure. A pull-out seal 37 is provided at the toner supply opening of the toner hopper 8, and the pull-out seal 3 is provided at the opening of the developer accommodating portion 5a at the upper part of the developing unit.
8 are attached. This is to prevent toner scattering at the time of transport and storage of a new product.
3 is what the user removes when starting to use it.

As shown in FIG. 2, one end of the agitator 11 is attached with one end side film member 40 and an auxiliary film member 41a shorter than the one end side film member 40 by a double-sided tape. Film member 40
The other end-side film member 41, which is shorter than that, is attached by a double-sided tape. In the present embodiment, as the film members 40, 41 and 41a, a polyester film (P
ET film), but is not limited to this. When the product is new, the agitator 11 is arranged as shown in FIG. 2, and one end side film member 40 closes the toner supply port outlet.

FIG. 3 is a perspective view showing the agitator.
As shown in FIG. 3, the agitator 11 has one end side film member 40 serving to block the toner outlet when new.
Auxiliary film member 4 for supplying toner to toner supply path
1, and further on the one end side film member 40 (agitator 1
As shown in FIG. 4, an auxiliary film member 41 a is attached with a double-sided tape 45 on the downstream side in the direction of rotation of the motor 1. In the present embodiment, the other end side film member 41 is used.
The auxiliary film member 41a and the auxiliary film member 41a are made of the same component, and these components are used in common, thereby preventing errors during assembly and simplifying component management.

Each of the film members 40, 41 and 41a has a thickness of 0.05 mm, and if it is thicker, the one end side film member 40 is too strong to close the replenishment outlet and cannot be completely closed. Also, if the other end side film member 41 is too thick, the force for feeding the toner when the amount of toner is reduced becomes too strong, and the toner density increases.

FIG. 5 shows the measurement results obtained by dividing the amount of toner to be sent out for two rotations of the agitator with the developing sleeve removed from the developing device, divided into three parts in the longitudinal direction. This figure 5
In the two bar graphs on the left, the mylar stuck on the agitator 11 is the result of the conventional case, in which the auxiliary film member is not stuck on one end side film member. At this time, the particle size was 9.5 μm.
Has a feed amount of about 6 g and does not cause density unevenness due to defective toner replenishment.
In the case of (small particle size toner), the toner feed amount was reduced to 5 g due to poor fluidity, and density unevenness occurred due to insufficient toner replenishment.

On the other hand, the rightmost bar graph shows the toner feed amount when the agitator 11 of the present embodiment is used while using the small particle size toner, and the toner feed amount is increased to 7.6 g. As a result, no defective replenishment occurred, and no density unevenness occurred.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, one end and the other end film members 40, 4
1 is attached with a double-sided tape, and the auxiliary film 41a is attached on one end side film member 40 with a double-sided tape 45. However, the present invention is not limited to this, and the auxiliary film 41a may be attached with an adhesive.

In this embodiment, the photosensitive drum 1, the charging device 36, the cleaning device 35, and the developing device 2
Although it is configured as one process cartridge 43, the invention is not limited to this, and at least one of the photosensitive drum 1, the charging device 36, the cleaning device 35 and the developing device 2
One process cartridge 43 may be configured.

Although the present invention has been applied to a copying machine, the present invention is not limited to this. For example, a similar effect can be obtained by applying the present invention to a printer, a facsimile, or a multifunction peripheral thereof.

[0035]

According to the first aspect of the present invention, since the auxiliary seal shorter than the film member on one end is provided so as to overlap the seal on one end of the agitator, the toner having a small particle size is used. However, stable toner supply can be achieved.

According to the second aspect of the invention, the same effect as that of the first aspect of the invention is obtained, and the other end film member and the auxiliary seal are made the same part, and these parts are shared. In addition, it is possible to prevent mistakes during assembly and simplify parts management.

According to the third aspect of the present invention, the same effects as those of the first or second aspect can be obtained, and the auxiliary seal is provided on the one end side film member at the downstream side in the rotation direction of the agitator. Can be supplied more reliably.

According to the fourth aspect of the invention, it is possible to provide the same operation and effect as those of the first to third aspects of the invention, and to provide high image quality without image density unevenness.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a process cartridge of a copying machine according to the present invention.

FIG. 2 is an exploded sectional view showing the process cartridge of FIG.

FIG. 3 is a perspective view showing a part of an agitator.

FIG. 4 is an enlarged side view showing one end of an agitator.

FIG. 5 is a graph showing a relationship between a toner particle size and a toner feed amount.

FIG. 6 is a cross-sectional view schematically showing a conventional developing device and its periphery.

[Explanation of symbols]

 Reference Signs List 1 photoconductor drum (image carrier) 2 developing device 4 developing sleeve (developer carrier) 4a magnet (magnetic force generating member) 5a, 5b developer accommodating section 6 first doctor blade (first regulating member) 11 agitator 12 Second developer regulating member (second regulating member) 35 Cleaning device (cleaning device) 36 Charging device (charging device) 40 One end side film member 41 Other end side film member 41a Auxiliary film member 43 Process cartridge

Claims (4)

[Claims] 1. A developer carrying member having a magnetic field generating means therein for carrying and transporting a two-component developer including a toner and a magnetic carrier, and a developer carrying and transporting the developer carried by the developer carrying member. A first regulating member for regulating the amount, a developer accommodating portion for accommodating the developer scraped off by the first regulating member,
A second regulating member disposed upstream of the first regulating member in the direction of transport of the developer on the developer carrying member; and a developer agitator which is adjacent to the developer accommodating portion and which is driven to rotate by an agitator. A toner container for supplying the toner to the body, wherein the developer blocked by the first regulating member forms a developer circulation portion upstream of the second regulating member in the developer conveying direction. One end of the agitator of the toner storage section is provided with one end film member, and the other end is provided with the other end film member. The one end film member is longer than the other end film member. A developing device, wherein an auxiliary film member shorter than the one end film member is provided on the one end film member. 2. The developing device according to claim 1, wherein the auxiliary film member is the same part as the other end side film member. 3. The developing device according to claim 1, wherein the auxiliary film member is provided downstream of the one end film member in the rotation direction of the agitator. 4. A process cartridge which integrally supports at least one means selected from an image carrier, a charging means and a cleaning means and a developing device and is detachable from an image forming apparatus main body. A process cartridge, wherein the apparatus is the developing apparatus according to claim 1.