JP3221745B2 - Cleaning device in image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device in an image forming apparatus such as a laser beam printer and a facsimile.

[0002]

2. Description of the Related Art Conventionally, as a cleaning device in an image forming apparatus of this type, a photosensitive member carrying a latent image on a surface thereof,
A developing unit for developing the latent image into a toner image, a transfer unit for transferring the toner image to a transfer body, and a plurality of cleaning units each having a cleaning blade for removing toner remaining on the surface of the photoconductor. What is provided is known as seen in Japanese Patent Publication No. 3-65980.

[0003]

However, in such a toner, the residual toner removed from the surface of the photoreceptor by the cleaning blade contains foreign matter such as paper dust. Since there is no means for separating the residual toner, if such residual toner is reused as it is, the quality of an image deteriorates, and there is a problem that it is difficult to reuse the residual toner.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional image forming apparatus, and to reuse the residual toner removed from the surface of the photoreceptor by a cleaning blade as it is. An object of the present invention is to provide a cleaning device in an image forming apparatus that does not reduce the quality of an image.

[0005]

In order to achieve the above object, the present invention is directed to a photoconductor having a latent image on a surface thereof and a toner image formed on the surface of the photoconductor. A developing unit for developing the toner image onto a transfer member, and a plurality of cleaning units sequentially arranged on the outer periphery of the photosensitive member along a rotation direction of the photosensitive member. In an image forming apparatus having a cleaning blade for removing the toner on the outer peripheral surface of the photoreceptor by contacting the outer periphery of the photoreceptor when the body rotates, each of the cleaning blades contacts the outer periphery of the photoreceptor. An upstream end in the rotation direction of the body, a tip corner for pressing against the outer periphery of the photoconductor in a direction opposite to the rotation direction, a tangent line at a contact point between the tip corner and the outer periphery of the photoconductor, and a tip of each cleaning blade. With the plane The cleaning angle formed,
The cleaning angle of the first cleaning blade closest to the transfer unit is set smaller than the cleaning angles of the other cleaning blades, and further, a toner conveying member for conveying the toner removed by each of the cleaning blades is provided. It is characterized by having. According to a second aspect of the present invention, in the first aspect, the toner transporting member of the first cleaning blade among the toner transporting members transports the toner to the developing unit. .

[0006]

According to the present invention, when an image forming operation is started, a latent image is formed on a photosensitive member based on image data in the same manner as in a conventional image forming apparatus. Then, the toner image is developed in a developing unit, and the toner image is transferred in a transfer unit in a state where the photoconductor and the recording paper are in contact with each other. The recording paper on which the image is transferred in this manner is transported by a transport member (not shown). The image is conveyed to the fixing unit and the image is fixed. The toner remaining on the surface of the photoconductor on which the image has been transferred to the recording paper in this manner is removed by the cleaning blades of a plurality of cleaning means. However, since these cleaning blades have different installation conditions, The first cleaning blade removes toner having a small amount of fine powder such as paper dust, the subsequent cleaning blade removes other toner, and separates the removed toner by a corresponding transport member (not shown). The toner is conveyed to the waste toner tank, and the toner contained in the waste toner tank having a small amount of fine particles is collected and reused. In this case, the transporting member corresponding to the first cleaning blade transports the toner removed from the surface of the photoconductor to the developing unit without transporting the toner to the waste toner tank, and reuses the toner. According to the third aspect of the present invention, a plurality of developing units are provided, and toner development of different colors is obtained.
Since the electrical properties are different and the installation conditions of the respective cleaning blades are different correspondingly, the toner on the surface of the photoreceptor is removed by the color toner which is the first cleaning means, and then the second cleaning blade is replaced by the second cleaning means. The cleaning means after the second cleaning means removes toners of other colors or toners containing fine powder and collects them separately, and reuses them except toner containing fine powders. According to a fourth aspect of the present invention, the toner containing the fine powder removed in the above case is transported to a waste toner tank, and the toner is transported to a developing unit for developing a toner image of a corresponding color without transporting the toner to the waste toner tank. To reuse. According to a fifth aspect of the present invention, after the transfer operation is completed, the photoreceptor is once rotated in the opposite direction to remove the fine powder caught between the photoreceptor and the cleaning blade so that the fine powder adheres to the photoreceptor. To separate from the cleaning blade, and further rotate the photoconductor in the opposite direction to remove fine powder from the photoconductor by the cleaning blade.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first embodiment of the present invention shown in FIG.
1 is a photoreceptor carrying a latent image on its surface, 2 is a developing section for developing the latent image into a toner image, 3 is a transfer section for transferring the toner image to a transfer body, and 4-1 and 2 are photoreceptors 1 The first and second cleaning blades 5-1 and 5-2 for removing the toner remaining on the surface of the printer, and the first and second transport members 6-1 and 2-2 for transporting the toner removed by the cleaning blades 5-1 and 5-1. In this embodiment, two cleaning means, two cleaning means, 7 is a charger, and 8 is an eraser. The first and second cleaning blades 5-1 and 5-2 are in contact with the photoreceptor 1 under different conditions of the normal force N, the protrusion amount l, and the cleaning angle θ calculated by the Young's modulus E during the operation shown in FIG. . The installation conditions of the first and second cleaning blades 5-1 and 5-2 are different. FIG. 3 shows the amount of toner passing through the blade at different angles of the toners having the average particle diameters of 7.5 μm and 12 μm and the fine powder of the paper powder, respectively. The cleaning angle θ of the first cleaning blade 5-1 is set to about 83 °, and the second cleaning blade 5-
The cleaning angle θ of No. 2 was set to 88 °.

In the above-described apparatus, when the image forming operation is started, the photosensitive member 1 is rotated clockwise as indicated by an arrow in the same manner as in the conventional image forming apparatus, and based on the image data. When the latent image formation is started, the toner image is developed in the developing unit 2 and the toner image is transferred in the transfer unit 3 in a state where the photosensitive member and the recording paper are in contact with each other. The image is fixed by being conveyed to a fixing unit by a conveying member (not shown). The toner remaining on the surface of the photoreceptor 1 on which the image has been transferred to the recording paper is removed by the first and second cleaning blades 5-1 and 5-1 of the first and second cleaning means 4-1 and 4-2. However, the first and second cleaning blades 5
Since the first and second cleaning angles are set at different cleaning angles as described above, the first cleaning blade 5-1 removes toner having a small particle size of about 9.5 μm, such as paper dust, and the second cleaning blade 5-1. The toner containing other fine powder is removed by 5-2, and these toners are respectively conveyed to separate waste toner tanks (not shown) by the first and second conveying members 6-1 and 2-2. The toner conveyed by the conveying member 6-1 and stored in the waste tank for the toner with a small amount of fine powder is collected and reused.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, the first conveying member 6-1 does not convey the toner removed from the surface of the photosensitive member 1 to the waste toner tank. The second embodiment is exactly the same as the first embodiment except that it is transported to the developing unit 2 and reused.

FIG. 5 shows a third embodiment of the present invention. This embodiment has a plurality of developing units (two in this embodiment).
And the first and second developing units 2-1 and 2-2 for developing toners of different colors. A second charging charger 9 is provided between the first and second developing units 2-1 and 2-1. First in that
This is different from the embodiment. In such a case, the first developing unit 2-1 uses black toner having a particle size of 7.5 μm,
The developing unit 2-2 uses a red toner having a particle diameter of 12 μm,
The cleaning angle θ of the first cleaning blade 5-1 of the first and second cleaning means 4-1 and 4-2 is set to 79 °, and the cleaning angle θ of the second cleaning blade 5-2 is set to 88.
After the transfer operation is performed in the same manner as in the first embodiment, the red toner is removed by the first cleaning unit 4-1 from the residue on the surface of the photoconductor 1, and the second cleaning unit 4-2 is removed. , The black toner and other fine powder are removed and collected separately, and the red toner is reused. In addition, although not shown, a third developing unit, a third cleaning means having a third cleaning blade and a third conveying member are further provided, and the cleaning angle θ of the first cleaning blade of the first, second and third cleaning means is set to 79. °
Then, the cleaning angle θ of the second cleaning blade is set to 83
And the cleaning angle θ of the third cleaning blade is set to 88 °, thereby performing the transfer operation in the same manner as described above. , And the black toner is removed by the second cleaning means, and the other fine powder is removed by the third cleaning means, and then separately collected, and the red toner and the black toner are reused.

FIGS. 6 to 8 show a fourth embodiment of the present invention. In this embodiment, after the transfer operation is completed as described above, the clockwise rotation as shown by the arrow in FIG. 6 is performed. In order to remove the fine powder 11 caught between the photoconductor 1 and the cleaning blade 5, the photoconductor 1 is rotated counterclockwise as shown by an arrow in FIG. Then, the photoreceptor 1 is rotated clockwise as indicated by an arrow shown in FIG. 8 and the fine powder 11 is removed from the photoreceptor 1 by the cleaning blade 5.

[0012]

The present invention is as described above. According to the first aspect of the present invention, there is provided a photoconductor having a latent image on a surface thereof;
A developing unit that develops the latent image into a toner image, a transfer unit that transfers the toner image to a transfer body, and a plurality of cleaning units that are sequentially arranged on the outer periphery of the photoconductor along a rotation direction of the photoconductor, In an image forming apparatus, each cleaning unit has a cleaning blade that contacts the outer periphery of the photoconductor when the photoconductor rotates and removes toner on the outer peripheral surface of the photoconductor. At the time of contact with the photoconductor, on the upstream side in the rotation direction of the photoconductor, the photoconductor has a tip corner that presses against the outer periphery of the photoconductor in the opposite direction to the rotation direction, and a tangent line at a contact point between the tip corner and the outer periphery of the photoconductor. The cleaning angle of the first cleaning blade closest to the transfer section is determined by the cleaning angle of the other cleaning blade. It is set to be smaller than the ring angle,
Further, since a toner conveying member that conveys the toner removed by each of the cleaning blades is provided, it is possible to separate the toner from the reusable toner with little fine powder such as paper dust by the preceding first cleaning blade. Possible, as a result, as in the invention according to claim 2, a member for transporting the toner removed by the first cleaning blade is provided separately from a member for transporting the toner removed by another cleaning blade, The toner is directly conveyed to the developing unit by the separately provided conveying member, so that the toner can be reused immediately, thereby providing an effect of obtaining a stable quality image.

[Brief description of the drawings]

FIG. 1 is a front view showing an arrangement of each part according to a first embodiment of the present invention.

FIG. 2 is a partial view showing installation conditions of the cleaning blade according to the first embodiment.

FIG. 3 is a diagram showing a correlation between the cleaning angle and the amount of toner passing through the blade.

FIG. 4 is a front view showing an arrangement of each part according to a second embodiment of the present invention.

FIG. 5 is a front view showing an arrangement of each part according to a third embodiment of the present invention.

FIG. 6 is a partial view of a fourth embodiment of the present invention immediately after a transfer operation is completed.

FIG. 7 is a partial view showing the next state of the above.

FIG. 8 is a partial view showing the next state of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoreceptor 2 Developing part 3 Transfer part 4 Cleaning means 5 Cleaning blade 6 Transport member

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 21/10-21/12 G03G 15/01-15/01 117

Claims (2)

(57) [Claims] A photosensitive member for carrying a latent image on a surface thereof; a developing portion for developing the latent image into a toner image; a transfer portion for transferring the toner image to a transfer member; A plurality of cleaning means sequentially disposed on the outer periphery of the photoreceptor, wherein each cleaning means comes into contact with the outer periphery of the photoreceptor when the photoreceptor rotates, and removes toner on the outer peripheral surface of the photoreceptor. In the image forming apparatus having the above, each of the cleaning blades has a tip corner that is in pressure contact with the outer periphery of the photoconductor in a direction opposite to the rotation direction on the upstream side in the rotation direction of the photoconductor at the time of contact with the outer periphery of the photoconductor. The cleaning angle formed between the tangent at the contact point between the tip corner and the outer periphery of the photoreceptor and the tip surface of each cleaning blade is the cleaning angle of the first cleaning blade closest to the transfer portion. Wherein the cleaning angle is set smaller than the cleaning angles of the other cleaning blades, and further provided are toner conveying members for conveying the toner removed by the respective cleaning blades. apparatus. 2. The cleaning device according to claim 1, wherein the toner transport member of the first cleaning blade among the toner transport members transports the toner to the developing unit.