JP2001356600A - Process cartridge and image forming apparatus - Google Patents

Abstract

(57) [Summary] [Object] To provide a process cartridge capable of reliably preventing a developer from leaking or scattering from a developer accommodating container. A developer container having at least an opening facing an endlessly movable rotator and accommodating a developer therein, and a longitudinal end portion of the opening of the developer container having an opening in the developer container. In the process cartridge, which is provided and has a seal member 7e which comes into contact with the surface of the rotating body, the developing member remaining on the contact surface of the seal member 7e is contacted with the developing member. A groove (guide mechanism) 10 for moving and guiding the inside of the agent storage container 7d is provided. According to the present invention, the sealing member 7
Since the groove 10 is provided on the contact surface of the rotating member with the sealing member 7e, the developer remaining in the contact surface between the sealing member 7e and the rotating member can be guided by the groove 10 to the developer container 7d.
The developer container 7d.
Leakage or scattering of the developer from the developer can be reliably prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus employing an electrophotographic system, an electrostatic recording system, and the like, and a process cartridge detachably mountable to the image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, for example, in an image forming apparatus employing an electrophotographic method, an elastic blade is applied to the surface of a photosensitive drum as a cleaning device for removing toner remaining on the surface of the photosensitive drum as an image carrier. A so-called blade cleaning method of making contact is widely known. FIGS. 9 and 10 show a schematic configuration of a laser beam printer as an image forming apparatus having such a cleaning device. The photosensitive drum has an organic photosensitive layer and is driven to rotate at a predetermined process speed in a direction indicated by an arrow. 101 is
First, the surface is uniformly charged by a charging roller 102 as a contact charging device.

Next, scanning exposure is performed on the photosensitive drum 101 by a laser beam 103 that is ON / OFF controlled according to image information, and an electrostatic latent image is formed on the photosensitive drum 101. The electrostatic latent image is transferred to the photosensitive drum 10
The toner image is developed by the developing device 104 disposed opposite to the image forming device 1 and is visualized as a toner image.

Here, the developing device 104 has a developing sleeve 104a which is driven to rotate in the direction of the arrow shown in the drawing, and an elastic developing blade 104b which comes into contact with the surface of the developing sleeve 104a, and is charged to a negative polarity. The toner 104c is included. As a developing method, for example, a jumping developing method is used, and image exposure and reversal developing are used in combination.

[0007] The visualized toner image is transferred to a transfer portion 106 facing the transfer roller 105 which is pressed against the photosensitive drum 101 and is driven to rotate in the direction of the arrow shown in the figure.
The transfer material P transferred to the surface of the transfer material P conveyed at a predetermined timing and onto which the toner image has been transferred is transferred to the fixing device 10.
7 and is discharged outside the apparatus after the toner image is fixed as a permanent image.

Incidentally, the photosensitive drum 101 after the transfer step has been completed.
The transfer residual toner slightly remaining on the surface of the toner image is removed by the cleaning device 108.

The cleaning device 108 includes a cleaning blade 108a made of urethane rubber which abuts on the surface of the photosensitive drum 101 in a so-called counter direction, and the cleaning blade 108a
A squeeze sheet 108b for collecting toner scraped off from one surface, a storage container 108c for storing toner scraped from the surface of the photosensitive drum 101,
The storage container 1 is attached to the wall surface of the storage container 108c located at the longitudinal end of the cleaning blade 108a, and one surface of the cleaning blade 108a comes into contact with the surface of the photosensitive drum 101.
And a seal member 108d (see FIG. 10) for preventing leakage and scattering of the toner from the toner cartridge 08c. Here, for example, felt or pile made of polytetrafluoroethylene, high-density foamed polyurethane foam, or the like is generally used for the seal member 108d.

In this laser beam printer, the photosensitive drum 101, the charging roller 102, the developing device 104, and the cleaning device 108 are integrated to constitute a process cartridge 109. It is attached to and detached from the printer body.

[0009]

By the way, in the conventional cleaning device, the following problems may occur.

In recent years, for example, the number of printable sheets with one process cartridge has tended to increase (ie, the life of the process cartridge has been prolonged). The amount of toner also increases.

A seal member provided in the cleaning device has a function of suppressing leakage and scattering of the toner in the storage container to the outside by abutting on the surface of the photosensitive drum. Becomes longer, the amount of toner accumulated in the contact surface between the seal member and the photosensitive drum inevitably increases. When the amount exceeds the allowable amount, the toner overflows from the contact surface between the seal member and the photosensitive drum and overflows. Toner adheres to the end of the photosensitive drum,
The particles scatter and contaminate the inside of the image forming apparatus and the transfer material.

In order to prevent the above-mentioned inconveniences, for example, it is conceivable to increase the width of the seal member or increase the contact pressure of the seal member against the surface of the photosensitive drum. The lengthwise direction becomes large, and the main body of the image forming apparatus also becomes large, which does not match the current situation where the personal use of the laser beam printer is increased and the miniaturization of the apparatus is desired.
In addition, the rotational torque of the photosensitive drum increases, and a more powerful driving motor is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to prevent leakage or scattering of the developer from the developer storage container without increasing the size or significantly increasing the cost. A process cartridge and an image forming apparatus that can reliably prevent the developer and collect the developer into the developer storage container even if the developer adheres to the surface of the rotating body outside the developer storage container opening; Is to provide.

[0014]

In order to achieve the above object, the present invention provides a developer container having at least an opening facing an endlessly movable rotating body and capable of housing a developer therein. A seal member disposed at a longitudinal end of the developer container opening and in contact with the surface of the rotating body. ,
A guide mechanism is provided for moving and guiding the developer remaining on the contact surface into the developer container.

According to the present invention, there is provided a developer container having at least an opening facing an endlessly movable rotator and accommodating a developer therein, and a longitudinal direction of the developer container opening. In an image forming apparatus having an end portion and a seal member abutting on the surface of the rotating body, the developer remaining on the abutting surface on the surface of the sealing member abutting on the surface of the rotating body. A guide mechanism for moving and guiding the developer into the developer container is provided.

Therefore, according to the present invention, since the guide mechanism is provided on the contact surface of the seal member with the surface of the rotary member, the developer remaining in the contact surface between the seal member and the rotary member can be removed. The developer can be sequentially moved into the developer storage container by the action, and the leakage or scattering of the developer from the developer storage container can be performed without increasing the size of the process cartridge or the image forming apparatus or significantly increasing the cost. This can be reliably prevented, and even if the developer adheres to the surface of the rotating body outside the opening of the developer container, it can be collected into the developer container.

[0017]

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

First Embodiment First, a schematic configuration of a laser beam printer as an image forming apparatus according to the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a photosensitive drum as an image carrier, and the photosensitive drum 1 is formed by applying a photosensitive material such as OPC to an outer peripheral surface of a cylindrical base made of aluminum or the like. The outer diameter is set to 24 [mm]. The photosensitive drum 1 has a length of about 40 [m]
m / sec] is driven at a peripheral speed rotation, the surface thereof is uniformly charged to about -600 [V] as a dark portion potential V _D by a charging roller 2 as a contact charging device. Here, to the charging roller 2, for example, an oscillating voltage obtained by superimposing an AC voltage having a frequency of 350 [Hz] and a peak-to-peak voltage of 2000 [V] on a DC voltage of -600 [V] is applied.

Next, the scanning exposure by the laser beam 3 whose ON / OFF is controlled according to the image information is performed on the photosensitive drum 1.
To form an electrostatic latent image of about -150 [V] as a light portion potential _VL on the photosensitive drum 1. The electrostatic latent image formed in this manner is developed by the developing device 4 arranged opposite to the photosensitive drum 1 and is visualized as a toner image. Here, the developing device 4 has a developing sleeve 4a that is driven to rotate and an elastic developing blade 4b that comes into contact with the surface of the developing sleeve 4a, and includes a one-component toner 4c that is negatively charged. Therefore, for the developing sleeve 4a, for example,-
An oscillating voltage in which an AC voltage having a frequency of 1800 [Hz] and a peak-to-peak voltage of 1600 [V] is superimposed on a DC voltage of 400 [V] is applied. As a developing method, for example, a jumping developing method is used, and image exposure and reversal developing are used in combination.

The visualized toner image on the photosensitive drum 1 is applied to the transfer roller 5 at a transfer portion 6 facing the transfer roller 5 which is pressed against the photosensitive drum 1 and driven to rotate. While a voltage (transfer bias) having a polarity opposite to the charging polarity is applied, the image is electrostatically transferred onto the surface of the transfer material P conveyed to the transfer portion 6 at a predetermined timing. The transfer residual toner slightly remaining on the surface of the photosensitive drum 1 after the transfer process is completed.
Removed by

Thereafter, the transfer material P on which the toner image has been transferred is conveyed to a fixing device 8, where the toner image is fixed on the transfer material P as a permanent image by the fixing device 8, and the transfer material on which the toner image has been fixed is fixed. P is discharged outside the machine.

In this laser beam printer, the photosensitive drum 1, the charging roller 2, the developing device 4 and the cleaning device 7 are integrated to constitute a process cartridge 9. This process cartridge 9 is a laser beam printer main body. It is attached to and detached from.

Next, details of the cleaning device 7 will be described with reference to FIG. FIG. 2 shows the cleaning device 7.
FIG.

The cleaning device 7 is a cleaning blade 7b made of urethane rubber which is supported by a sheet metal 7a and abuts on the surface of the photosensitive drum 1 in a so-called counter direction.
And the photosensitive drum 1 by the cleaning blade 7b.
Squeeze sheet 7c for collecting toner scraped off from the surface, storage container 7d for storing toner scraped from the surface of photosensitive drum 1, and storage container located at the longitudinal end of cleaning blade 7b A sealing member 7e is attached to the wall surface of 7d, and one surface thereof contacts the surface of the photosensitive drum 1 to prevent leakage and scattering of toner from the storage container 7d.

In this embodiment, as shown in the perspective view of FIG. 3, a plurality of inclined surfaces are provided on the contact surface of the seal member 7e with the surface of the photosensitive drum 1 with respect to the rotation direction of the photosensitive drum 1. The groove 10 was formed. The L-shaped seal member 7e has a plurality of grooves 10 formed on the surface of the elastic member 11 made of, for example, urethane foam having a thickness of 5 [mm] and having a thickness of 0.4 [mm]. The sheet-like member 12 is attached by, for example, a double-sided tape. In addition, as a material of the sheet-like member 12, for example, polyacetal,
Polyphenylene sulfide, polyarylate, polybutylene terephthalate, and the like include resins and metals to which polytetrafluoroethylene is added at a ratio of 5 to 30%, but are not limited thereto, and are not limited to abrasion resistance. Those having excellent properties and slidability are more preferable. And as a manufacturing method, injection molding etc. are mentioned.

Alternatively, the groove 10 may be formed by providing convex portions of a different material at predetermined intervals on a base material such as a polyester film using a contact printing screen or the like.

The seal member 7e is attached to the end wall surface of the storage container 7d by, for example, a double-sided tape or the like, and abuts the surface of the photosensitive drum 1 by elasticity so as to follow the curvature of the photosensitive drum 1. This sealing member 7
The groove 10 formed on the photosensitive drum 1 is inclined with respect to the rotating direction of the photosensitive drum 1, and more specifically, in the contact surface of the sealing member 7 e with the photosensitive drum 1, on the upstream side in the rotating direction of the photosensitive drum 1. It has a slope from the outside to the inside of the storage container 7d with respect to the direction from the to the downstream side (the direction of arrow A in FIG. 4).

The toner 4c staying in the contact surface between the seal member 7e and the photosensitive drum 1 is conveyed by the rotation of the photosensitive drum 1 and guided by the inclined groove 10 in the direction of arrow B in FIG. (That is, in the direction toward the inside of the storage container 7d). The inclination angle θ of the groove 10 with respect to the rotation direction A of the photosensitive drum 1 may be less than 90 [°].
In the present embodiment, θ = 45 [°] in consideration of the length of the seal member 7 e in the rotation direction A of the photosensitive drum 1.
And

The depth of the groove 10 is preferably substantially equal to the particle size of the toner 4c.
Any value may be used as long as the toner 4c that has entered the groove 10 when deformed by contacting the surface can contact the surface of the photosensitive drum 1. In the present embodiment, the value is set to 0.2 [mm].
The interval between them was 0.5 [mm].

The results of experiments conducted by the present inventors to explain the function and effect of the guide mechanism constituted by the groove 10 formed in the seal member 7e will be described below.

An image forming apparatus using a process cartridge having a guide mechanism as a seal member provided in the cleaning device shown in this embodiment and a conventional process cartridge not having such a guide mechanism is used. A continuous durability test was performed in which the printer was attached to the main body and printed continuously.

As a result of the continuous durability test, in the process cartridge having the guide mechanism, no leakage, scattering, image stain, and the like of the toner from the storage container occurred even at 10,000 sheets, which was set as a life target in advance. Then, when the cleaning device and the photosensitive drum were separated and the surface of the seal member was observed, although there was some dirt,
The situation was such that the toner mass was fixed and deposited.

On the other hand, in the conventional process cartridge having no guide mechanism, the toner starts to adhere over the entire circumferential area of the surface of the photosensitive drum facing the seal member after the elapse of 7000 sheets. In the above, it was confirmed that the toner mass that could not be completely collected was dropped into the image forming apparatus main body, and the transfer material end was also stained. When the cleaning device and the photosensitive drum were separated from each other and the surface of the seal member was observed, a lump of toner was fixed and accumulated on the surface of the seal member.

As described above, by providing the guide mechanism on the surface of the seal member for guiding the toner to the inside of the storage container, it is possible to increase the size of the apparatus and significantly increase the cost without inconvenience. It is possible to reliably prevent the toner from leaking and scattering, and even if the toner adheres to the surface of the photosensitive drum outside the opening of the storage container, the attached toner can be collected into the storage container. Become.

In this embodiment, the elastic member 1
Although the seal member 7e having a two-layer structure of the sheet member 1 and the sheet member 12 is used, a seal member obtained by integrally molding these members may be used. The same effect can be obtained as the above.

In the present embodiment, the photosensitive drum 1 and the cleaning device 7 have been described as being integrated as a process cartridge 9. However, the photosensitive drum unit and the cleaning unit are separately configured as a unit. Even if there is, the present invention is applicable.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a partial perspective view of the cleaning device according to the present embodiment. In this drawing, the same elements as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. .

In the first embodiment, the groove 10 is formed in the entire width direction of the contact surface of the seal member 7e with the photosensitive drum 1. However, in the present embodiment, the seal member 7e is formed further outside the groove 10. It is characterized in that an elastic member 12 serving as a base material is wrapped around.

According to the present embodiment, for example, even if the process cartridge 9 is subjected to an impact when the process cartridge 9 is attached to or detached from the image forming apparatus main body, or if the process cartridge 9 is held at an angle, it is stored. Leakage and scattering of toner from the container 7d can be reliably prevented.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIGS.

This embodiment shows a case where the present invention is applied to a developing device having a rotatable developing sleeve, and the same members as those described in the first embodiment are denoted by the same reference numerals. The description of them is omitted.

The developing device 4 shown in FIG.
c, a rotatable developing sleeve 4a as a toner carrier disposed in an opening of the storing container 4d, and a so-called counter direction supported by a sheet metal 4e with respect to the surface of the developing sleeve 4a. A developing blade 4b made of urethane rubber contacting the developing blade 4b, a blowing prevention sheet 4f for preventing toner from leaking from below the developing sleeve 4a, and a storage container 4d positioned at a longitudinal end of the developing blade 4b. It is provided with a sealing member 4g for preventing the toner from leaking and scattering from the storage container 4d by being attached and one surface of which is in contact with the surface of the developing sleeve 4a.

Thus, as shown in FIG.
As in the first embodiment, a groove 10 is formed on the contact surface of the developing sleeve 4a with respect to the rotation direction of the developing sleeve 4a. Note that the seal member 4g is provided at the end on the near side in the drawing of FIG.

FIG. 7 is an exploded view of the sealing member 4g. As shown in FIG. 7, the I-shaped sealing member 4g is formed on the surface of an elastic member 11 such as urethane foam having a thickness of 5 mm. A sheet-like member 12 having a thickness of 0.4 [mm] and having a plurality of grooves 10 on its surface is attached by, for example, a double-sided tape. Examples of the material of the sheet-like member 12 include polyacetal, polyphenylene sulfide, polyarylate, polybutylene terephthalate, and the like.
Examples thereof include resins and metals to which polytetrafluoroethylene is added at a ratio of 5 to 30%, but are not limited thereto, and those having excellent wear resistance and slidability are more preferable. preferable. And as a manufacturing method, injection molding etc. are mentioned.

Alternatively, the groove 10 may be formed by providing convex portions made of another material at predetermined intervals on a base material such as a polyester film using a contact printing screen or the like.

The sealing member 4g is attached to the end wall surface of the container 4d formed along the curvature of the developing sleeve 4a by, for example, a double-sided tape or the like, and its surface is elastically applied to the developing sleeve 4a. Contact the surface. Here, the groove 10 is provided in the developing sleeve 4a.
Specifically, a direction from the upstream side to the downstream side in the rotation direction of the developing sleeve 4a in the contact surface of the sealing member 4g with the developing sleeve 4a (arrow C in FIG. 8). Direction) from the outside of the storage container 4d toward the inside.

Then, the sealing member 4g and the developing sleeve 4
The toner 4c staying in the contact surface with the a moves in the direction of arrow D (that is, the direction toward the inside of the storage container 4d) due to the conveying force due to the rotation of the developing sleeve 4a and the guiding effect of the inclined groove 10. . The inclination angle ψ of the groove 10 with respect to the rotation direction C of the developing sleeve 4a may be less than 90 °, but in the present embodiment, the length of the seal member 4g in the rotation direction C of the developing sleeve 4a is considered. 20
[°].

The depth of the groove 10 is preferably substantially equal to the particle diameter of the toner. However, when the sealing member 4g is deformed by contacting the surface of the developing sleeve 4a, the toner that has entered the groove 10 is deposited on the surface of the developing sleeve 4a. Any value may be used as long as it can be contacted, and in this embodiment, it is 0.1 [mm], and the interval between the grooves 10 is 0.3 [mm].

Thus, in the present embodiment, the same effects as in the first embodiment can be obtained. In the present embodiment, the seal member 4g having a two-layer structure of the elastic member 11 and the sheet-like member 12 is used. However, a seal member formed by integrally molding these members may be used. The same effect can be obtained if the cross-sectional shape is not only rectangular but also triangular or semicircular.

[0051]

As is apparent from the above description, according to the present invention, since the guide mechanism is provided on the contact surface of the seal member with the surface of the rotating body, the contact surface between the seal member and the rotating body is provided. The developer remaining in the developer container can be sequentially moved into the developer storage container by the action of the guide mechanism, and can be removed from the developer storage container without increasing the size of the process cartridge or the image forming apparatus or significantly increasing the cost. Of the developer can be reliably prevented, and even if the developer adheres to the surface of the rotating body outside the opening of the developer storage container, the developer is collected in the developer storage container. The effect that it can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an image forming apparatus according to the present invention.

FIG. 2 is a perspective view of a main part of the cleaning device according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a seal member according to Embodiment 1 of the present invention.

FIG. 4 is an operation explanatory view of the seal member according to the first embodiment of the present invention.

FIG. 5 is a perspective view of a seal member according to Embodiment 2 of the present invention.

FIG. 6 is a sectional view of a process cartridge (developing device) according to Embodiment 3 of the present invention.

FIG. 7 is a perspective view of a seal member according to Embodiment 3 of the present invention.

FIG. 8 is an operation explanatory view of a seal member according to Embodiment 3 of the present invention.

FIG. 9 is a cross-sectional view of a main part of a conventional image forming apparatus.

FIG. 10 is a schematic configuration diagram of a conventional cleaning device.

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum (image carrier: rotating body) 4 developing device 4c toner (developer) 4d developer storage container 4e sealing member 7 cleaning device 7d developer storage container 7e sealing member 9 process cartridge 10 groove (guide mechanism)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Sunahara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Satoshi Motobashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term in reference (reference) 2H034 AA06 BF01 BF03 CA04 2H071 BA04 BA22 BA35 BA36 DA08 DA13 2H077 AA14 AD06 BA03 BA08 BA09 CA02 CA12

Claims (8)

[Claims] A developer container having at least an opening facing a rotatable endlessly movable body and accommodating a developer therein, and a developer container arranged at a longitudinal end of the opening of the developer container. A process cartridge having a seal member in contact with the surface of the rotating body, wherein the developer accommodating on the surface of the seal member in contact with the surface of the rotating body contains the developer remaining in the corresponding contact surface. A process cartridge provided with a guide mechanism for moving and guiding inside. 2. The image forming apparatus according to claim 1, wherein the rotating body is an image carrier, and the developer accommodating container forms a cleaning device that collects the developer remaining on the surface of the image carrier and accommodates the developer. Item 4. The process cartridge according to Item 1. 3. The developing device according to claim 1, wherein the rotating body is a developer carrier, and the developer accommodating container is a developing device that accommodates a developer for visualizing an electrostatic latent image formed on the surface of the image carrier. The process cartridge according to claim 1, wherein the process cartridge is configured. 4. The process cartridge according to claim 1, wherein said guide mechanism comprises a plurality of grooves inclined with respect to a moving direction of said rotating body. 5. A developer container having at least an opening facing an endlessly movable rotator and accommodating a developer therein, and a developer container disposed at a longitudinal end of the developer container opening. An image forming apparatus provided with a seal member that abuts on the surface of the rotating body, wherein a developer that stagnates on the contact surface of the seal member on the surface of the rotating body contains the developer. An image forming apparatus comprising a guide mechanism for moving and guiding the inside of a container. 6. The image forming apparatus according to claim 1, wherein the rotating body is an image carrier, and the developer container forms a cleaning device that collects and stores the developer remaining on the surface of the image carrier. Item 6. The image forming apparatus according to Item 5. 7. The developing device according to claim 1, wherein the rotating body is a developer carrier, and the developer accommodating container is a developing device that accommodates a developer for visualizing an electrostatic latent image formed on the surface of the image carrier. The image forming apparatus according to claim 5, wherein the image forming apparatus is configured. 8. The image forming apparatus according to claim 5, wherein the guide mechanism includes a plurality of grooves inclined with respect to a moving direction of the rotating body.