JPH09197817A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a sealing effect, even if a developing device is used for a long period by rotating a sealing roller in a direction opposite to that of a developing roller and abutting a scraper on the sealing roller in a part nearer to the downstream side than the contact part, of the sealing roller and the developing roller. SOLUTION: A sealing member consists of a rubber roller made of silicone rubber, etc., or the sealing roller 9 with elasticity which is constituted in such a manner that the rubber roller is covered with fluororesin, etc. This sealing roller 9 is brought into contact with the developing roller 2 and rotated in the direction opposite to that of the developing roller 2. Further, the scraper 10 for which a urethane rubber blade, etc., are used is abutted on the sealing roller 9 in the part nearer to the downstream side in a rotational direction than the contact part, of the sealing roller 9 and the developing roller 2. The circumferential speed Vd of the sealing roller 9 is set higher than or equal to the circumferential speed Vs of the developing roller 2, so that residual toner can be easily recovered without spilling and the recovered toner is removed from the sealing roller 9 by the scraper 10, to be carried into a container 5 along the arrow D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention develops an electrostatic latent image formed on a photosensitive member into a visible image by using a non-magnetic one-component developer by an electrophotographic method and converts the visible image into a visible image. The present invention relates to a developing device such as a copying machine or a printer for transferring an image onto a transfer material to obtain an image.

[0002]

2. Description of the Related Art A developing device using a non-magnetic one-component developer is widely used in copying machines, printers and the like because of its simple structure and low cost.

As a construction of such a developing device, a non-magnetic toner which is a developer contained in a developing container is supplied onto a developing roller as a rotating developer carrier to form a thin toner layer. Then, the toner layer is conveyed to a developing area facing the photoconductor to develop the electrostatic latent image, and then the toner remaining on the developing roller is collected again in the developing container.

A seal member made of a soft material such as a sponge is attached to the recovery unit for recovering the residual toner in order to prevent the toner in the container from flowing out and to recover the residual toner without spilling out of the container. There is.

[0005]

However, when the conventional developing device as described above is used for a long period of time, the toner in the container penetrates into the bubbles of the sponge, which is the seal member, so that the elasticity of the seal member is reduced. Loss of the toner or thermal deformation of the seal member due to heat of rubbing makes it impossible to obtain a sufficient sealing effect, resulting in toner outflow from the container and poor recovery of residual toner.
There was a spill.

Therefore, an object of the present invention is to provide a developing device which can secure a sufficient sealing effect even when it is used for a long period of time.

[0007]

According to the first invention of the present application, the above object is to provide a developing container capable of accommodating a developer and having an opening, and exposing a part of the surface from the opening. Thus, the developer carrier which is rotatably disposed and carries and conveys the developer in the developing container, and the developer conveyed to the area where the surface of the developer carrier is exposed are collected again in the developing container. In a developing device having a seal member arranged to come into contact with the developer carrying member in the collecting section, the seal member is rotatably arranged in the opposite direction to the developer carrying member. The scraping member is arranged so that the scraping member comes into contact with the rotary member on the downstream side in the rotation direction of the rotary member with respect to the contact portion between the rotary member and the developer carrying member. To be achieved.

According to the second invention of the present application,
In the first aspect of the invention described above, the ratio of the peripheral velocity Vs of the developer carrying member and the peripheral velocity Vd of the rotating member is Vd / V.
This is achieved by setting s = 1.0 to 2.0.

Further, according to the third invention of the present application, the above-mentioned object is that, in the above-mentioned first invention or the second invention, the rotating member is an elastic roller having a rubber layer on a core metal. To be achieved.

According to the fourth invention of the present application,
The above object is achieved in any one of the first to third inventions, in which the scraping member is an elastic sheet.

Further, according to a fifth invention of the present application, the above-mentioned object is the contact portion between the rotating member and the scraping member in any one of the above-mentioned first to fourth inventions. Is also achieved by providing a cleaning member that comes into contact with the rotating member on the downstream side in the rotating direction of the rotating member.

According to the sixth invention of the present application,
The above object is any one of the first to fifth inventions, wherein the rotating member is made conductive or semiconductive, and the developer is transferred to the rotating member from the rotating member to the developer carrier. This is achieved by applying such a bias.

Further, according to a seventh invention of the present application, in the above object, in any one of the first invention to the fifth invention, the rotating member has a triboelectrification characteristic of the same polarity as that of the developer. Achieved by having.

According to the eighth invention of the present application,
The above-mentioned object is achieved in any one of the above-mentioned first to seventh inventions in that the surface roughness of the rotating member is equal to or lower than the surface roughness of the developer carrying member.

Further, according to the ninth invention of the present application,
The above object can be achieved by, in any one of the first to eighth inventions, the rotating member being pressed against the developer carrying member by a predetermined pressure by a pressing means.

That is, in the first aspect of the present invention, the developer in the developer container carried and conveyed by the developer carrier is conveyed from the inside of the developer container to the region where the surface of the developer carrier is exposed. The developer that has been developed and remains on the developer carrier without being developed is further collected in the developing container by the rotation of the developer carrier. Then, in the collecting portion, the developer on the developer carrying member enters the contact portion between the developer carrying member and the seal member, but the seal member rotates in the direction opposite to the developer carrying member. Therefore, the developer that has entered the abutting portion is conveyed to the inside of the developing container without being blocked, and the developer on the sealing member is also removed by the scraping member and collected in the developing container.

According to the second aspect of the present invention,
Since the ratio of the peripheral speed Vs of the developer carrying member and the peripheral speed Vd of the rotating member is set to Vd / Vs = 1.0 to 2.0, the developer that has entered this section is dammed. It is reliably transported without being spilled, and is collected in the developing container without spilling from the opening of the developing container.

Further, according to the third invention of the present application, since the rotating member is the elastic roller having the rubber layer on the cored bar, the elastic roller comes into pressure contact with the developer carrier to flow out the developer in the developing container. The seal member is securely sealed without being used, and the developer does not enter the rotating member itself even after long-term use.

According to the fourth invention of the present application,
Since the scraping member is an elastic sheet, it scrapes off the developer on the rotating member without imposing an excessive load on the rotating member.

Further, according to the fifth invention of the present application, since the cleaning member that comes into contact with the rotary member is provided on the downstream side in the rotation direction of the rotary member with respect to the contact portion between the rotary member and the scraping member. , The developer not scraped by the scraping member is surely removed from the rotating member.

According to the sixth invention of the present application,
Since the rotating member is made conductive or semi-conductive, and a bias such that the developer is transferred from the rotating member to the developer carrying member is applied to the rotating member, it is difficult for the developer to adhere to the rotating member. The developer can be easily removed by the scraping member.

Further, according to the seventh invention of the present application, since the rotating member has the triboelectric charging characteristic of the same polarity as that of the developer, the rotating member and the developer are electrostatically repelled to each other on the rotating member. By making it difficult for the developer to adhere, the removal of the developer by the scraping member becomes easy.

According to the eighth invention of the present application,
Since the surface roughness of the rotating member is equal to or lower than the surface roughness of the developer carrying member, the developer is more likely to be bound to the developer carrying member side than the rotating member, and the developer is less likely to adhere to the rotating member. It becomes easy to remove the developer.

Further, according to the ninth invention of the present application,
Since the rotating member is pressed against the developer carrier with a predetermined pressure by the pressing means, the developer is stably collected.

[0025]

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

(First Embodiment) First, a first embodiment according to the present invention will be described with reference to FIGS. Further, for comparison with the present invention, a conventional example device will also be described with reference to FIG.

FIG. 2 shows the overall structure of the developing device according to the first embodiment of the present invention. In FIG. 2, 1
Is a photoconductor, and the photoconductor 1 is provided with a developing roller 2 as a developer carrier formed of a metal such as stainless steel or aluminum with a predetermined gap between the photoconductor 1 and the photoconductor 1. Reference numeral 2 is embedded in a developing container 5 containing a non-magnetic toner T as a developer.

The toner T is supplied onto the developing roller 2 by a supply roller 4 made of silicone sponge or the like which comes into contact with the developing roller 2 and rotates in the same direction as the developing roller 2, and has elasticity and comes into contact with the developing roller 2. The toner is regulated to a predetermined toner layer thickness by a blade 3 formed of silicone rubber or urethane rubber, and is applied onto the developing roller 2. The toner T is triboelectrically charged when it is rubbed by the blade 3 onto the developing roller 2,
The toner is held on the developing roller 2 by a mirroring force which is an electrostatic attraction between the toner T and the toner T.

The toner coated on the developing roller 2 in this manner is conveyed to the developing area facing the photoconductor 1 as the developing roller 2 rotates, and the electrostatic latent image previously formed on the photoconductor 1 is transferred. Although the latent image becomes a visible image by adhering to the image, the toner remaining on the developing roller 2 without adhering to the latent image is conveyed as it is and collected in the developing container 5 in the collecting section R.

Therefore, the toner T in the developing container 5 is gradually consumed, but when the remaining amount becomes less than a predetermined amount, the toner T is removed from the toner storage portion (not shown) along the arrow F. The toner is replenished and conveyed to the supply roller 4 by the toner conveying members 7 and 8.

As described above, the developing device of this embodiment has substantially the same components as the conventional developing device, but the structure of the recovery section R is different from that of the conventional developing device. Hereinafter, the recovery unit R in the developing device of the present embodiment will be described. To clarify the difference from the conventional example, first, the configuration of the conventional device will be described with reference to FIG.

FIG. 3 shows the toner collecting section R of the above-mentioned developing device.
It shows a conventional configuration in the vicinity, and the same parts as those in FIG. 2 are denoted by the same reference numerals.

Also in the apparatus shown in FIG. 3, the toner T in the developing container 5 is supplied onto the developing roller 2 by the supply roller 4 along the arrow A, is applied onto the developing roller 2 by the blade 3, and is sent to the developing area. However, the toner T remaining on the developing roller 2 after the developing process is conveyed to the collecting unit.

On the developing container wall 22 near the collecting section,
A seal member 21 made of a flexible elastic material such as sponge having substantially the same length as the developing roller 2 is attached along the direction of the rotation axis of the developing roller 2. Similarly, a thin sheet member 23 made of PET or the like is attached to the lower portion of the container wall 22 over the same length as the developing roller 2, and its free end side is a contact portion between the developing roller 2 and the seal member 21. It is sandwiched. Further, the sheet member 23 is brought into contact with the developing roller 2 side with a very light pressure due to the elasticity of the seal member 21.

In this conventional structure, in the initial stage of use of the developing device, the seal member 21 prevents the toner in the container from leaking to the outside along the arrow C, and the residual toner on the developing roller 2 is prevented. The residual toner can be satisfactorily collected in the container 5 by passing the sheet in the direction of the arrow B while slipping between the sheet member 23 and the developing roller 2 that have been lightly contacted.

However, when this developing device is used for a long time, the toner in the container 5 enters the inside of the sealing member 21 and the sliding member 21 is thermally deformed and hardened by the heat of sliding friction with the developing roller 2 to seal the toner. Sheet member 23 by member 21
The sheet member 23 is strongly pressed against the developing roller 2 by virtue of the increased pressing force. Therefore, the residual toner is blocked by the sheet member 23, and a part of the residual toner T
₁ will not be collected and will spill in the direction of arrow D.
The spilled toner pollutes the inside of the machine and causes malfunction of other parts and adheres to the transfer material, which causes image contamination.

Therefore, in the present invention, as shown in FIG. 1, the seal member is constituted by a rotating member such as a seal roller 9 having elasticity, and the seal roller 9 is brought into contact with the developing roller 2. The developing roller 2 was rotated in the opposite direction, and a scraper 10 as a scraping member was brought into contact with the seal roller 9.

The peripheral speed Vd of the seal roller 9 is set to be equal to or higher than the peripheral speed Vs of the developing roller 2, and the residual toner can be easily collected in the collecting portion without spilling.
Then, the collected toner is removed from above the seal roller 9 by the scraper 10 that is in contact with the seal roller 9, and is conveyed into the container 5 along the arrow E.

According to this structure, the toner in the container 5 is not blocked by the scraper 10 and the seal roller 9 and leaks to the outside. Since the residual toner is rotated in the direction to convey the residual toner to the inside of the container 5, the residual toner can pass through the contact portion and be collected in the container without being blocked by the seal roller 9. Further, even if the developing device is used for a long time, the seal roller 9 is constantly rotated and the residual toner is taken into the container 5, so that the toner spill does not occur.

The seal roller 9 is composed of a rubber roller made of silicone rubber, urethane rubber, fluororubber or the like, or an elastic roller obtained by coating the rubber roller with fluororesin or the like. Absent. The scraper 10 is a urethane rubber blade or P
An elastic sheet of ET sheet is used.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the first embodiment, the seal roller 9 is used.
Although the scraper 10 scrapes off the toner adhered to the upper part, if a large amount of toner adheres to the seal roller 9, it may not be possible to scrape off all the adhered toner. The adhered toner that has not been scraped is conveyed to the contact portion between the developing roller 2 and the seal roller 9 again as the seal roller 9 rotates, and is scraped after passing through the contact portion. However, if the amount of toner that cannot be scraped increases, the toner may accumulate in the contact portion, and some of the toner may spill.

In the present embodiment, as shown in FIG. 4, this is to prevent this, and a cleaning member 11 that comes into contact with the seal roller 9 is provided downstream of the scraper 10 along the rotation direction of the seal roller 9. . The cleaning member 11 can clean and remove the toner that has not been scraped off by the scraper, and can prevent the toner from collecting on the contact portion. A brush, a flocked cloth, or the like is used as the cleaning member.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

It is also possible to make it difficult for toner to adhere to the seal roller 9. In this embodiment, as shown in FIG. 5, the seal roller 9 is provided between the seal roller 9 and the developing roller 2.
A bias is applied such that the toner adhered to the toner is transferred from the seal roller 9 to the developing roller 2.

The above-mentioned rubber roller is used as the seal roller 9,
Alternatively, an elastic roller in which carbon powder or the like is dispersed and which is made conductive or semiconductive is used. The toner on the developing roller 2 is applied to the developing roller 2 in the developing process.
AC (alternating) voltage 12 and DC voltage 13 in order to fly
Is applied, and a positive DC voltage 14 is further superimposed on the seal roller 9.

FIG. 5 shows the case where the charge polarity of the toner is positive. Since the seal roller 9 is biased toward the positive side of the developing roller 2, the positive toner is transferred from the seal roller 9 to the developing roller 2. . As a result, the amount of adhered toner on the seal roller 9 can be reduced, and the scraper 10 can completely remove the adhered toner.

The bias applied to the seal roller 9 is not limited to the DC voltage, but DC voltage and AC (alternating) voltage may be superimposed.

Further, by using a material having a charging characteristic of the same polarity as the toner as the material of the seal roller 9, the seal roller 9 and the toner are electrostatically repelled so that the toner does not adhere to the seal roller 9. Is also good.

Alternatively, the surface roughness Rz of the seal roller 9
By making d smaller than the surface roughness Rzs of the developing roller 2, the toner may be more easily bound to the developing roller 2 side than the seal roller 9 and may be less likely to adhere to the seal roller 9.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In order to stably collect the residual toner, it is desirable that the contact pressure between the seal roller 9 and the developing roller 2 be maintained constant. Contact pressure becomes too small and the seal roller 9
If a gap is formed between the contact portion between the developing roller 2 and the developing roller 2, the developing container 5
Part of the toner inside may slip through the contact portion and leak to the outside. Further, when the contact pressure becomes excessive, the toner is crushed at the contact portion, and the seal roller 9 or the developing roller 2
And it cannot be removed with the scraper 10,
The toner application unevenness on the developing roller 2 occurs.

Therefore, in this embodiment, as shown in FIG. 6, the contact pressure between the seal roller 9 and the developing roller 2 can be maintained constant. The developing roller 2 is rotatably supported at its both ends by a developing container 6 via bearings (not shown), and the sealing roller 9 is fixed at the both ends to the developing container 6 by pressing springs 15a and 15b as pressing means. Pressed to 2. The springs 15a, 15 are arranged so that the contact pressure between the seal roller 9 and the developing roller 2 becomes an appropriate value.
The spring constant b is an appropriate value. As a result, the contact pressure can always be kept constant.

[0054]

As described above, the first embodiment according to the present application is described.
According to the invention, since the seal member that abuts the developer carrying member is a member that rotates in the opposite direction to the developer carrying member, the developer that has entered the abutting portion is conveyed to the inside of the developing container without being damped, and further sealed. The developer on the member can also be removed by the scraping member and can be stably collected in the developing container, and the developer can be prevented from leaking out of the developing container even when the developing device is used for a long time. You can

According to the second invention of the present application,
Since the ratio of the peripheral velocity Vs of the developer carrying member and the peripheral velocity Vd of the rotating member is set to Vd / Vs = 1.0 to 2.0, the developer from the opening of the developing container is opened. Spills can be reliably prevented.

Further, according to the third invention of the present application, since the rotating member is the elastic roller having the rubber layer on the cored bar, the developer does not penetrate into the rotating member itself even if it is used for a long time. Even when used for a long time, the developer can be stably collected and the developer leakage can be reliably prevented.

According to the fourth invention of the present application,
Since the scraping member is an elastic sheet, the developer on the rotating member can be scraped off without giving an excessive load to the rotating member.

Further, according to the fifth invention of the present application, since the cleaning member which comes into contact with the rotary member is provided on the downstream side in the rotation direction of the rotary member with respect to the contact portion between the rotary member and the scraping member. The developer that has not been scraped by the scraping member can be reliably removed from the rotating member.

According to the sixth invention of the present application,
Since the rotating member is made conductive or semi-conductive, and a bias such that the developer is transferred from the rotating member to the developer carrying member is applied to the rotating member, it is difficult for the developer to adhere to the rotating member. The developer can be completely removed by the scraping member.

Further, according to the seventh invention of the present application, since the rotating member has the triboelectric charging characteristic of the same polarity as the developer, the rotating member and the developer are electrostatically repulsed and the rotating member is repelled. By making it difficult for the developer to adhere, the developer can be completely removed by the scraping member.

According to the eighth invention of the present application,
Since the surface roughness of the rotating member is equal to or lower than the surface roughness of the developer carrying member, the developer is more likely to be bound to the developer carrying member side than the rotating member, and the developer is less likely to adhere to the rotating member. By this, the developer can be completely removed.

Further, according to the ninth invention of the present application,
Since the rotating member is pressed against the developer carrier with a predetermined pressure by the pressing means, the developer can be stably collected.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a toner recovery unit of a developing device according to a first embodiment of the present invention.

FIG. 2 is an overall view of the developing device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a toner recovery unit of a conventional developing device used for comparison with the first embodiment of the present invention.

FIG. 4 is a diagram showing a toner recovery unit of a developing device according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a toner recovery unit of a developing device according to a third embodiment of the present invention.

FIG. 6 is a diagram for explaining a pressing method for a seal roller and a developing roller according to a fourth embodiment of the present invention.

[Explanation of symbols]

 2 developing roller (developer carrier) 5 developing container 9 seal roller (sealing member, rotating member) 10 scraper (scraping member) 11 cleaning members 15a, 15b pressure spring (pressing means) T toner (developer)

Claims (9)

[Claims] 1. A developer container capable of accommodating a developer and having an opening, and a developing device rotatably disposed so as to expose a part of the surface from the opening and carrying and carrying the developer in the developing container. A seal member disposed so as to abut on the developer carrying body and a collecting section for collecting again the developer carried to the area where the surface of the developer carrying body is exposed into the developing container. In the developing device including, the seal member is a rotating member that is rotatably arranged in a direction opposite to the developer carrying member, and the rotating member includes the rotating member and the developer carrying member. The developing device is arranged such that the scraping member abuts on the downstream side of the abutting portion in the rotation direction of the rotating member. 2. The ratio between the peripheral velocity Vs of the developer carrying member and the peripheral velocity Vd of the rotating member is set to Vd / Vs = 1.0 to 2.0. The developing device described. 3. The developing device according to claim 1, wherein the rotating member is an elastic roller having a rubber layer on a cored bar. 4. The developing device according to claim 1, wherein the scraping member is an elastic sheet. 5. The cleaning member, which comes into contact with the rotating member, is provided on the downstream side of the abutting portion between the rotating member and the scraping member in the rotation direction of the rotating member. The developing device according to one item. 6. The rotating member is made conductive or semi-conductive, and a bias is applied to the rotating member so that the developer is transferred from the rotating member to the developer carrying member. 5. The developing device according to any one of 5. 7. The developing device according to claim 1, wherein the rotating member has a triboelectrification characteristic having the same polarity as that of the developer. 8. The developing device according to claim 1, wherein the surface roughness of the rotating member is less than or equal to the surface roughness of the developer carrying member. 9. The rotating member is brought into pressure contact with the developer carrying member at a predetermined pressure by a pressing means.
The developing device according to claim 8.