JP3312815B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blocking member for contacting a photosensitive member between a charging charger and a cleaning unit in order to prevent a toner cloud generated in a cleaning unit from reaching the inside of the charging charger. Image forming apparatus.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, a situation occurs in which a toner cloud generated in a cleaning unit reaches the inside of a charger and adheres to a charging wire to cause a charging failure. On the other hand, in order to prevent the toner cloud from reaching the inside of the charged charger, a mylar was brought into contact with the photosensitive member and stuck to a photosensitive member case or the like between the cleaning unit and the charged charger. . In this case, there is a drawback that the mylar impedes the airflow at the same time, and the ozone generated by the charging charger stays in the charging charger.

[0003] The direction of the dust-containing airflow flowing from the cleaning section toward the charging charger with the rotation of the photosensitive drum is changed by a dust-proof sheet member that closes a gap between the charging charger and the photosensitive drum. It has already been proposed to prevent the inflow and prevent the inside of the charger from being stained by sending clean air into the charger by a fan or the like (Japanese Patent Laid-Open No. 61-200).
556).

In order to shorten the life of the charging wire and prevent pollution of the environment due to ozone generated at the time of charging, an ozone absorbent is disposed inside the shield plate of the charging charger or in the passage of airflow from the charging charger. It has also been proposed (Japanese Utility Model Application Laid-Open No. 58-135754, Japanese Patent Application Laid-Open No. 3-56980).

[0005]

In the first proposal,
As a result, the generated ozone flows out into the room, and the problem of environmental pollution has not been solved. In addition, the toner remaining on the dust-proof sheet member that has not been cleaned by the cleaning unit adheres and damages the photoreceptor, or the adhered toner enters the charging charger to cause a leak, or adheres to the charging wire to charge the charging wire. Caused a defect. Further, since a fan or the like for sending clean air into the charging charger is required, the configuration is inevitably complicated and expensive.

In the second proposal, the ozone absorbent is disposed at a position slightly away from the photoconductor, so that ozone on the surface of the photoconductor cannot be completely removed.

An object of the present invention is to eliminate the above-mentioned disadvantages of the conventional image forming apparatus and to improve the charging performance.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided an ozone decomposing agent provided on a charging charger side of a blocking member which is in contact with a photoreceptor to block between a charging charger and a cleaning section. The problem is solved by that the blocking member moves from the central portion located on the cleaning portion side to both end portions located on the charging charger side while contacting the photosensitive member.

Furthermore, the present invention proposes that the blocking member is detachably attached to advantageously solve the above-mentioned problem.

[0010]

According to the present invention, since a blocking member is provided between the charging charger and the cleaning section for contacting the photoreceptor and blocking the both, the toner wound up by the cleaning section is contained in the charging charger. Is prevented from entering, and since an ozone decomposing agent is mounted on the charging charger side of the blocking member, ozone generated by the charging charger is removed, and the ozone decomposing agent is disposed close to the photoconductor. Therefore, ozone on the surface of the photoreceptor can be completely removed.

Further, since the blocking member is arranged in contact with the photosensitive member in a shape that transitions from the central portion located on the cleaning portion side to both end portions located on the charging charger side while contacting the photosensitive member, the blocking member is arranged in contact with the photosensitive member. When the toner that has flowed along the photoconductor from the cleaning unit side reaches the blocking member, it gradually flows toward the end of the blocking member, thereby preventing the toner from sticking to the blocking member. As a result, the photoreceptor is prevented from being scratched and the stuck toner is prevented from entering the charging charger, thereby preventing occurrence of charging failure and deterioration of the photoreceptor, and extending the life of the charging charger and the photoreceptor. It becomes possible.

Since the blocking member is detachably mounted, it is easy to replace. Even if the effect of the ozonolysis agent is lost over time, other parts are used as they are and only the blocking member is replaced, thereby reducing the cost. It is possible to extend the life of the charger and the photoconductor at a low cost.

[0013]

FIG. 1 shows an image forming apparatus to which the present invention is applied.
This will be described below.

The image forming apparatus shown in FIG. 1 includes a main body 1, a double-sided unit 2 and a paper feed cassette 3 which are sequentially arranged below the main body 1. This duplex unit 2
The paper feed cassette 3 is compatible with the main body 1 and the paper feed cassette 3 when the duplex unit 2 is not provided. In this image forming apparatus, the transfer paper 4 fed from the paper feed device 3a of the paper feed cassette 3 in the direction of arrow A is timed by a pair of registration rollers 5 to form a latent image composed of a belt-shaped photosensitive member 6. It is transported to the carrier.

The photoreceptor belt 6 travels clockwise by driving means (not shown), and the surface thereof is charged by a charger 7 at that time. Then, a laser beam L from the laser unit 8 is irradiated to form an electrostatic latent image on the photoconductor. This latent image is visualized by toner when passing through the developing device 9, and a toner image is formed. This toner image is transferred to the transfer paper 4 conveyed to the photoreceptor belt 6 under the action of the transfer charger 10, and the transferred transfer paper 4
Are separated by the curvature of the photoconductor 6. After the toner image is fixed on the transfer paper 4 by the fixing device 11, the switching control of the branch claws 12a and 12b is performed to the discharge tray 13 in the B direction, to the discharge tray 14 in the C direction, or to the D direction.
Transported to the duplex unit 2 in the direction. Reference numeral 15 denotes a cleaning unit that removes residual toner on the photosensitive belt 6 after transfer.

In the conventional image forming section shown in FIG. 2, the photoreceptor belt 6 has four rollers 20a, 20b, 20 positioned by photoreceptor cases 16a, 16b.
c, 20d, of which the driving roller 2
By 0a, it is rotated in the direction of the arrow shown in the figure. A charging charger 7 is attached to the photoconductor case 16a so as to face the photoconductor belt 6. Photoconductor case 16a, 16
The cleaning unit 15 includes a cleaning blade 17 for cleaning the toner on the photosensitive belt 6 and the toner collecting roller 1.
8 is provided.

The above-mentioned collecting roller 18 winds up the toner when rotating, and the toner becomes a toner cloud, and rides on the air current indicated by the arrow W in the figure generated by the running of the photoreceptor belt 6 and the suction action of the fan 19, Along the direction of the charger 7. As described above, the toner cloud generated in the cleaning unit 15 reaches the inside of the charger 7 and adheres to the charging wire to cause charging failure, as described above.

As shown in FIGS. 3 and 4, a sheet-like blocking member 22 is provided via an auxiliary member 21 outside the case 7 a of the charging charger 7 on the upstream side in the rotation direction of the photosensitive belt 6. It is detachably attached to the photoconductor case 16a. The blocking member 22 is in contact with the photoreceptor belt 6 to prevent the toner flowing along with the airflow from flowing into the charging charger 5.

Further, as shown in FIG. 4, an ozone decomposing agent 23 is applied or affixed to the charging charger side of the blocking member 22 to decompose ozone generated by the charging charger 7. Further, the ozonolysis agent 2
Since 3 is close to the photoreceptor belt 6, ozone on the photoreceptor belt 6 can be completely decomposed.

As shown in FIG. 5, the auxiliary member 21 has a cross-sectional shape of an isosceles triangle whose central portion protrudes toward the cleaning portion 15 and recedes toward the charger 7 from both ends from the central portion. Have. The blocking member 22
Is attached to the cleaning member side of the auxiliary member 21, that is, the center of the blocking member 22 contacts the photoreceptor belt 6 at the cleaning portion side, and the end contacts the photoreceptor belt 6 at the charging charger side. Reference numeral 22 indicates a gradual transition from the center toward the end.

With the above configuration, the cleaning unit 15
Toner flowing along the photoreceptor belt 6 from the side of
When the toner reaches the blocking member 22, the toner gradually flows toward the end of the blocking member, thereby preventing the toner from sticking to the blocking member.

Further, since the unit including the blocking member 22 and the auxiliary member 21 is detachably attached to the photoreceptor case 16a, when the blocking member 22 no longer has the ozone decomposing action, other components are used as they are. , Only the unit can be easily replaced with a new unit.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an image forming apparatus to which the present invention is applied.

FIG. 2 is an explanatory diagram of a conventional image forming unit of the image forming apparatus.

FIG. 3 is an explanatory diagram of an image forming unit configured according to the present invention.

FIG. 4 is a longitudinal sectional view showing a blocking member according to the present invention.

FIG. 5 is a cross-sectional view showing the blocking member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 6 Photoreceptor belt 7 Charging charger 15 Cleaning part 21 Auxiliary member 22 Interception member

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 21/00 370-540 G03G 15/00 550 G03G 21/16-21/18 G03G 15/02-15/02 103 G03G 21/10

Claims (2)

(57) [Claims] In an image forming apparatus, a charging member and a cleaning unit are blocked by a blocking member that contacts a photosensitive member in order to prevent a toner cloud generated in a cleaning unit from reaching the inside of the charging charger. ,
An ozone decomposing agent is provided on the charging charger side of the blocking member, and the blocking member moves from a central portion located on the cleaning portion side to both ends located on the charging charger side while contacting the photoconductor. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein said blocking member is detachably attached.