Toner Seal Method and Apparatus in Electrophotographic Recording Apparatus

1. (Field of the Invention)

This invention relates to a toner seal method and apparatus of a photosensitive member cleaning device disposed inside an electrophotographic recording apparatus.

2. (Description of the Prior Art)

The principal mechanism and the outline of the operation of an electrophotographic recording apparatus will be explained with reference to FIG. 6. As a general construction, a developing device 2 is disposed on the right of a photosensitive member 1 and a photosensitive member cleaning device 3 is disposed on the left. A transfer electrode 4 for a recording sheet of paper (hereinafter referred to as "paper") and a separating electrode 5 adjacent to the former are disposed below the photosensitive member 1, so that, paper 6 passes above the transfer electrode 4 and the separating electrode 5 while keeping contact tangentially with the photosensitive member 1.

The photosensitive member 1 is rotated continuously in a direction represented by arrow by a main motor, not shown in the drawing, and is provided with a predetermined potential by a charging electrode 1a. A latent image is first formed on the photosensitive member 1 by exposure 15 and when it reaches the position of the developing device 2, a toner 12 inside the developing device attaches to the portion of the 1a tent image due to the electrostatic action with the photosensitive member 1, forming thereby a toner image 16. On the other hand, paper 6 is transferred to the lower surface of the photosensitive member 1 by a pair of conveyor rollers 7a disposed on a front transfer table 7 and the toner image 16 is transferred to this paper 6 by the potential of the transfer electrode 4. After the potential applied at the time of transfer is removed by the separating electrode 5, paper 6 is subsequently transferred to a rear transfer table 7b and then to a fixing device 13, where fixing treatment is carried out. Thereafter, paper is discharged outside the electrophotographic recording apparatus and the image recording process is complete.

After the transfer to paper 6 is complete, the photosensitive member 1 is separated from paper 6 and reaches the cleaning device 3, where the residual toner 12a attaching to the surface and residual toner 12a attaching to the surface and other foreign matters such as paper dust are removed by a blade 3a fitted to the cleaning device 3. A recovery casing 9 of the cleaning device 3 is equipped with a toner guide plate 11 made of a PET material and is shaped in a sealed type. Particularly, its blade end portion surface and the portion of the photosensitive member surface of the photosensitive member 1 are provided with a toner seal member in order to prevent invasion and scatter of the residual toner 12a and the paper dust that have been removed, into the electrophotographic recording apparatus.

The inventions and devices related with the technique described above are well known in the art and are disclosed in the following references. As to the end portion seal of the photosensitive member blade, the following references are known:

Japanese Patent Laid-Open No. 155877/1984

Japanese Utility Model Laid-Open No. 122970/1985

As to the end portion seal of the blade, the following references are known:

Japanese Patent Laid-Open No. 72470/1984

Japanese Patent Laid-Open No. 15274/1984

Japanese Utility Model Laid-Open No. 30760/1982

Japanese Utility Model Laid-Open No. 115274/1985

As to the end portion seal of the toner guide plate, the following reference is known:

Japanese Patent Laid-Open No. 34580/1984

As to the end portion seal of the photosensitive member, the following references are known:

Japanese Utility Model Publication No. 12128/1985

Japanese Utility Model Laid-Open No. 16154/1985

Japanese Utility Model Laid-Open No. 159548/1983

As to the photosensitive member surface seal at the end portion of the photosensitive member, the following reference is known:

Japanese Utility Model Laid-Open No. 121474/1986

After cleaned in the manner described above, the photosensitive member 1 rotates again to the position of the exposure 15 with a predetermined potential and then the first step of image recording is started. In this way, the steps of exposure to the photosensitive member 1, development, transfer, separation, cleaning and fixing of the image to paper 6 are carried out repeatedly and continuously and image recording to paper 6 is effected.

The photosensitive member cleaning device 3 is one of the important functions of the electrophotographic recording apparatus with the developing device 2 and the fixing device 13. The residual toner 12a and the paper dust that attaches to the surface of the photosensitive member 1 are removed and cleaned by the cleaning device 3 after transfer and the exposure 15 is made to this cleaned photosensitive member surface. Accordingly, a clear toner image 16 can be always obtained. However, the residual toner 12a and the paper dust that have thus been removed enter and scatter from the side surface of the blade 3a and near the photosensitive member surface at the end portion of the photosensitive member 1 into the electrophotographic recording apparatus. They attach to the charging electrode 1a, the transfer electrode 4 and the separating electrode 5, contaminate the surfaces of a mirror and a lens, invite non-uniform transfer, the drop of density and non-uniform density that are detrimental to the recorded image and further cause troubles such as transfer jam of paper 6 due to incomplete separation. The frequency of the maintenance work must be increased in order to prevent these troubles and the economical loss is great.

Various inventions and devices have been developed conventionally as described already by disposing the toner seal member inside the cleaning device 3 in order to eliminate the problems described above. Though they provide a certain level of effects, none of them are entirely satisfactory. In other words, they divide, cut and patch up function-wise a flexible member such as a Moltopren, velvet or woolen cloth in such a manner as to come into contact with the photosensitive member surface, the blade end surface and the end surface of the toner guide plate, and the complicated and fine work relies exclusively on the skill of an assembling person. Accordingly, uniformity and reliability in mass-production are not yet complete.

In order to solve the problems described above, the present invention contemplates to provide a toner seal method and apparatus which can be adapted easily and reliably even to a narrow and complicated surface.

The object described above can be accomplished by either of the following method and apparatus.

In a photosensitive member cleaning device disposed inside an electrophotographic recording apparatus, a toner seal method which is characterized in that a toner seal member for preventing leakage of a residual toner on a photosensitive member surface, which is removed by a blade and stored in a recovery casing, is folded in such a manner as to come into contact with the photosensitive member surface, an end surface of the blade and an end surface of a toner guide plate for the casing which is in parallel with the end surface of the blade, and is bonded to the casing near a photosensitive member, said folding being made in a direction crossing the weaving direction of loops of a velvet woven fabric constituting the seal member.

In a photosensitive member cleaning device disposed inside an electrophotographic recording apparatus, a toner seal apparatus which is characterized in that a toner seal member for preventing leakage of a residual toner on a photosensitive member surface which is removed by a blade and stored in a recovery casing is bonded to the casing at its portion near a photosensitive member and an end portion of the blade, said seal member being bonded through a rigid member having a shape that models the casing to be bonded.

The above and other objects and novel features of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings.

FIGS. 1(a), 1(b) and 1(c) are top view, front sectional view and side sectional view of a velvet woven fabric used for a toner seal member in one embodiment of the present invention;

FIG. 2(a) is a sectional view of the velvet woven fabric folded in a direction parallel to a weaving direction of loops;

FIG. 2(b) is a sectional view of the velvet woven fabric folded in a direction crossing the weaving direction of loops, particularly at right angles;

FIG. 3 is a perspective view showing the bond position of the toner seal member to a recovery casing;

FIGS. 4(a) and 4(b) are front view and plan view showing the position relationship between the photosensitive member, the blade and the toner guide plate with respect to the toner seal member bonded to the casing:

FIGS. 5(a) and 5(b) are top sectional view and front view of the toner seal in accordance with the present invention.

FIG. 6 is a side view of a conventional electrophotographic recording apparatus.

As shown in FIGS. 3, 4(a) and 4(b), the casing 9 described above has a frame for supporting rotatably the photosensitive member 1 and for holding members such as a blade 3a, a toner transfer screw 10 and a toner guide plate 11, besides its function of storing the residual toner. Therefore, it has a complicated shape having an upper side surface portion, a bottom surface portion, a ridge line and a step portion and its space is extremely limited. Unlike the toner seal member of the prior art apparatuses, a toner seal member 8 in accordance with the present invention is made of a flexible fluff-like member such as a felt, a velvet or a woolen cloth and fixed to a rigid support member 8a such as a single metallic plate as shown in FIGS. 5 (a) and 5(b). This support member 8a is provided with a bent portion A in match with the shape of the casing 9 and a step portion D of a lower surface and is designed so that a surface C and the step portion D serve as bonding reference surfaces. A double-face adhesive tape 8b is bonded with an upper sheet 8c to the C surface side of the support member 8a. To fit the support member 8a to the casing 9, it can be bonded along the shape of the casing after peeling the upper sheet 8c as shown in FIG. 3. A surface portion B of the toner seal member 8 bonded in this manner covers an end surface of the photosensitive member 1 and the bent portion A simultaneously covers end surface portion of the blade 3a and toner guide plate 11 under the state where it comes into light pressure contact with them. Accordingly, it is sealed without applying any trouble to the operation of each of these members. Therefore, the residual toner 12a and paper dust recovered do not leak and scatter outside the casing 9 but are sequentially transferred to a predetermined position by the toner screw 10 through the toner guide plate 11 and are then recovered.

According to the structure described above, the fitting reference of the toner seal member 8 is clear and definite. Since it is equipped with the support member made of the stiff material, the toner seal member 8 can be fitted easily and reliably, its fitting does not require any specific skill and fitting variance during mass-production can be eliminated completely.

Since the present invention is constituted as described above, fitting of the toner seal member 8 is simple and reliable, the work done factor can be improved remarkably and leakage and scatter of the residual toner 12a and the paper dust into the electrophotogaphic recording apparatus do not occur. In consequence, contamination of important functional portions does not occur and a quality recorded image can be obtained for an extended period of time. Since the frequency of the cleaning maintenance work due to contamination inside the apparatus can be reduced remarkably, the economical effect is extremely great, too.

According to the embodiment described above, leakage of the toner from the toner storage portion of the casing 9 would not occur but the toner sometimes falls off from the folds of the woven fabric described already. Therefore, another embodiment of the present invention makes it possible to prevent the fall of the toner easily and reliably.

First of all, an example of fluffed woven fabrics 20 such as the velvet, the woolen cloth, etc (which will be sometimes referred to as the "velvet fabric") will be explained with reference to FIGS. 1(a), 1(b) and 1(c). Piles 24 of bundles of a large number of thin yarns are inserted and woven into wefts 22 or 23 in the same direction as warps 21 with a pitch of a predetermined number of warps 21 in the fabric woven by the warps 21 and the wefts 22, 23, and the loop-like piles between the adjacent wefts are finally cut at the intermediate portion. In this manner the fluffed woven fabric such as the velvet or the woolen cloth, to which the piles 24 are aligned in the same height and implanted, can be obtained as shown in the front sectional view of FIG. 1(b) or in the side sectional view of FIG. 1(c). The piles of this woven fabric are tightly bound by the warps 21 and the wefts 22 or 23 of the woven fabric and do not fall off, but a stitch fixing agent 25 is applied to the bottom portion of the fabric in order to prevent further strongly fall-off.

Incidentally, the structure of the warps and the wefts is not particularly limited to that of the embodiment described above. As the fluffed woven fabric, it is possible to use a moquette material consisting 100% of acrylic fibers and having the pile fluff length of 3 to 4 mm.

When such a woven fabric is used as the toner seal member by folding it, there are two folding methods, that is, the folding method which provides the folds in the direction in parallel with the warps 21 as shown in FIG. 2(a) and the folding method which provides the folds in the direction at right angles, or a certain angle, to the warps 21 as shown in FIG. 2(b). According to the former method, the pile density of the fold portions P is close to zero due to the properties of the woven fabric even when the expansion angle .theta. due to the turn-down of the pile yarns is taken into consideration, and the fold portion cannot at all play the role of the seal. Therefore, part of the residual toner 12a which has been scraped off falls down through this fold portion and contaminates the interior of the recording apparatus.

In contrast, in accordance with the latter, the pile yarn density of the folded portion Q does not much drop due to the expansion of the angle .theta. in the turn-down direction of the dense pile yarns, and the fall-off of the residual toner 12a does not occur. Though the intended object can be accomplished sufficiently even when this folding angle is not 90.degree., it is more preferably at right angles.

The bonding work of the toner seal member 8 to the limited position of the inner surface of the casing 9 having the complicated shape can be made easily and reliably without any specific skill by merely folding and bonding a single sheet of woven fabric in a predetermined direction but not cutting the woven fabric constituting the seal member into a plurality of pieces and bonding them. Moreover, the trouble of fall of the residual toner 12a into the recording apparatus can be eliminated completely.

Incidentally, bonding of the seal member 8 to the casing 9 is made by use of an adhesive. It can be made by coating the adhesive to the surface of the stitch fixing agent 25 or by bonding a double-face adhesive tape. Since the toner seal member 8 covers the photosensitive surface portion at the end of the photosensitive member 1 and the end surface portions of the blade 3a and the toner guide plate 11 under the lightly pressure-contact state, these members can be sealed without any trouble in their operations. Accordingly, the residual toner 12a and the paper dust recovered do not leak and scatter outside the casing but are transferred sequentially to the predetermined position by the toner screw 10 through the toner guide plate and recovered there.

Since this embodiment has the structure described above, fitting of the toner seal member can be made easily and reliably and the work done factor can be improved remarkably. Since leakage and scatter of the residual toner 12a and the paper dust into the electrophotographic recording apparatus do not occur, contamination of the important functional portions does not occur, either, a quality recorded image can be obtained for a long period and the economical effect is extremely great because the frequency of the cleaning maintenance work can be reduced remarkably.