JP3744700B2 - Cleaning unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cleaning unit.
[0002]
[Prior art]
Conventionally, a latent image is formed on a recording medium, the latent image is developed with toner to form a toner image, the toner image is transferred to a transfer paper, and then the toner remaining on the recording medium is removed by a cleaning blade. 2. Description of the Related Art A cleaning blade used for a magnetic photographic recording apparatus or an electrophotographic recording apparatus to be removed is known.
[0003]
[Problems to be solved by the invention]
However, there may be a case where foreign matter such as dust is attached to the surface of the transfer paper before the toner image is transferred. Further, during the transfer process of the transfer paper, foreign matter on the surface of the transfer paper may adhere to the surface of the recording medium. In this case, if the foreign matter is not removed from the surface of the recording medium in the cleaning process, the toner is adsorbed to the foreign matter in the next toner image forming step. As a result, the toner adsorbed on the foreign matter appears as black streaks on the surface of the next transfer paper, and the image quality deteriorates.
[0004]
Examples of the foreign matters include oily thin films such as dust and dirt, or dirt generated in a printing process and a cutting process, which is a problem when using a printing mount as a transfer paper. In addition, if the foreign matter adhering to the recording medium is not removed by the cleaning blade during the cleaning process, it is blocked by the cleaning blade or recorded while being thinned when passing through a slight gap between the cleaning blade and the recording medium. It is stretched on the medium and fixed on the recording medium. As a result, as described above, the toner is attracted to the foreign matter. As an experiment to support this idea, when the cleaning blade was intentionally removed, black spots occurred, but black streaks did not occur.
[0005]
Therefore, in order to prevent black streaks from occurring, it is necessary to prevent foreign matter from adhering to the recording medium. In order to prevent foreign matter from sticking to the recording medium, there is a method of using a rotating brush instead of the cleaning blade. However, if a rotating brush is used, there is a possibility that foreign matter will be firmly fixed on the recording medium. From the viewpoint of durability, it can be said that the cleaning blade is more suitable than the rotating brush.
[0006]
In view of the above problems, the present invention provides a cleaning unit capable of adsorbing an adhering matter on a recording medium to the toner before the adhering matter adheres to the recording medium and removing it from the recording medium together with the toner. Objective.
[0007]
[Means for Solving the Problems]
According to the present invention, a latent image is formed on a rotating drum type recording medium, the latent image is developed with toner to form a toner image, the toner image is transferred to a transfer material, and is left on the recording medium. In a cleaning unit used in a magnetic photographic recording apparatus or an electrophotographic recording apparatus that removes the removed toner with a cleaning unit and collects the removed toner with a suction fan , a counter contact type cleaning blade, and a cleaning blade It is attached to the surface opposite to the recording medium facing surface, extends substantially parallel to the cleaning blade and abuts against the recording medium, and from the cleaning blade toward the upstream side in the moving direction of the recording medium A protruding elastic member eaves, the cleaning blade, the eaves and the eaves A toner reservoir is formed in a space surrounded by the recording medium, and the toner that has flowed into the toner reservoir is effectively pressurized against the recording medium, whereby foreign matter including at least an oily thin film is retained in the toner reservoir. adsorbed to the toner to remove from the previous type recording medium, the toner adsorbs then the foreign substance cleaning unit, characterized in that is recovered extruded from the toner storing portion is provided.
[0008]
In the cleaning unit of the present invention , when the toner remaining on the recording medium after the transfer process is removed, the adhering matter adhering to the recording medium is adsorbed by the toner pressurized by the eaves and removed from the recording medium together with the toner. Is done. Therefore, the deposit can be removed from the recording medium before the deposit on the recording medium adheres to the recording medium. As a result, it is possible to reduce the occurrence of black streaks on the transfer material as the adhering matter adheres to the recording medium.
[0014]
The eaves may be formed by a planar brush .
[0015]
In the cleaning unit, since the eaves are formed by a planar brush, the cleaning effect of the brush alone can be expected.
[0016]
The surface of the eaves facing the recording medium may be I meshwork der.
[0017]
In the cleaning unit, since the surface of the eaves facing the recording medium has a mesh structure, the eaves improve the ability of holding the toner.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0019]
FIG. 1 shows a first embodiment in which the cleaning unit of the present invention is applied to an electrophotographic recording apparatus. As shown in FIG. 1, the electrophotographic recording apparatus of this embodiment using plain paper as a transfer material charges a recording medium 4 with a charger 7 and then responds to image information with a recording head 8 such as a laser scanner. Thus, the electrostatic charge image is changed to form an electrostatic latent image on the recording medium 4. The electrostatic latent image is developed with the toner 5 by the developing device 9. The toner image on the recording medium 4 is transferred onto the transfer material 12 by the transfer device 10. The toner image on the transfer material 12 is fixed to the transfer material 12 by heat or pressure by the fixing device 11. On the other hand, the residual toner on the recording medium 4 is removed by the cleaning blade 2 provided with the eaves 1.
[0020]
FIG. 2 is an enlarged view of the cleaning unit of this embodiment. As shown in FIG. 2, the cleaning unit of this embodiment has a structure in which an eaves 1 for damming up toner is provided on the conventional counter contact blade 102 shown in FIG. The eaves 1 have elasticity and protrude from the cleaning blade 2 substantially parallel to the surface of the recording medium 4 toward the upstream side in the moving direction of the cleaning blade 2 with respect to the recording medium 4. Therefore, the toner 5 is easily accumulated in the toner reservoir 3 and the toner is effectively pressurized. The toner 5 that has not yet entered the toner reservoir 3 agitates the toner in the toner reservoir 3 when entering the toner reservoir 3, and enters the toner reservoir 3, thereby causing the toner 1 and the cleaning blade 2 to move. I can be dammed up. When the foreign matter 6 adhering to the recording medium 4 enters the toner reservoir 3, the adhering force to the pressurized toner becomes larger than the adhering force to the recording medium 4. It is adsorbed by the toner in the toner reservoir 3. As a result, it is possible to avoid the occurrence of black streaks on the transfer material 12 due to the toner adsorbed by the foreign matter fixed on the recording medium 4. Even when the adhesion force of the foreign matter 6 to the recording medium 4 is large, by increasing the force with which the toner in the toner reservoir 3 is pressed by the eaves 1, the adsorption force of the foreign matter 6 to the toner is increased. The foreign material 6 can be peeled off from the recording medium 4.
[0021]
In order to increase the pressure of the toner in the toner reservoir 3 and cause the foreign matter 6 on the recording medium 4 to be adsorbed to the toner, first, it is necessary that the eaves 1 can hold a large amount of toner. For this purpose, it is preferable that the friction coefficient of the surface of the eaves 1 on the recording medium 4 side is large. For example, when the surface of the eaves on the recording medium side is formed of a low friction material such as polyethylene terephthalate, the toner slides against the eaves, and therefore the eaves can hold only a small amount of toner. Therefore, the toner pressure in the toner reservoir cannot be increased sufficiently so that foreign matter on the recording medium cannot be adsorbed to the toner. On the other hand, for example, when the surface of the eaves on the side of the recording medium is formed of a high friction material such as fine paper, the eaves can hold a large amount of toner, and therefore the pressure of the toner in the toner reservoir is sufficiently reduced. The foreign matter on the recording medium can be adsorbed by the toner. As the high friction material, a material having a network structure such as a cloth material is suitable.
[0022]
In order to increase the pressure of the toner in the toner reservoir 3 and cause the foreign matter 6 on the recording medium 4 to be adsorbed to the toner, secondly, the eaves 1 always has a constant pressure against the toner in the toner reservoir 3. It is necessary to be able to give For this purpose, it is preferable that the gap between the eaves 1 and the recording medium 4 is sufficiently small, and that the eaves 1 is made of an elastic material so that the pressure fluctuation of the toner in the toner reservoir 3 can be absorbed. is there.
[0023]
Next, a second embodiment of the cleaning unit of the present invention will be described. The configuration of the cleaning unit of the second embodiment is substantially the same as that of the first embodiment shown in FIG. 1 except that the eaves are different from those of the first embodiment. FIG. 4 is an enlarged view of the eaves of this embodiment. As shown in FIG. 4, the eaves 51 of the present embodiment extends from the cleaning blade 2 substantially parallel to the cleaning blade 2 and abuts against the recording medium 4. That is, there is no bent portion like the eaves 1 of the first embodiment. Therefore, in the eaves 51 of the present embodiment, it is possible to avoid the difficulty of bending the eaves with high accuracy.
[0024]
On the other hand, in this embodiment, since the tip of the eaves is in contact with the recording medium 4, it is necessary to allow the toner to flow between the eaves 51 and the recording medium 4 by passing between the tip of the eaves and the recording medium 4. . Therefore, in this embodiment, the eaves 51 are formed of an elastic material. As a result, the eaves 51 are easily lifted with respect to the recording medium 4. Therefore, a toner reservoir is formed between the eaves 51 and the recording medium 4, and the toner in the toner reservoir is effectively pressurized. The Therefore, it is possible to achieve substantially the same effect as the eaves of the first embodiment.
[0025]
Next, a third embodiment of the cleaning unit of the present invention will be described. The configuration of the cleaning unit of the third embodiment is substantially the same as the configuration of the second embodiment shown in FIG. 4 except that the eaves are different from those of the second embodiment.
[0026]
In this embodiment, in order to more positively control the inflow and outflow of the toner in the toner reservoir layer, the eaves 61 formed of an elastic material is formed by a flat dense brush. As a result, even if the eaves 61 are not easily lifted with respect to the recording medium 4, the toner can flow between the eaves 61 and the recording medium 4 through the gap of the brush. Therefore, a toner reservoir is formed between the eaves 61 and the recording medium 4, and the toner in the toner reservoir is effectively pressurized. Therefore, it is possible to achieve substantially the same effect as the eaves of the first embodiment. In addition, in the present embodiment, since the eaves 61 are formed by a flat dense brush, a cleaning effect of the brush alone can be expected. Furthermore, the frequency with which the toner in the toner reservoir is replaced can be adjusted by adjusting the density of the bristles of the brush.
[0027]
As described above, in the first to third embodiments, the detoxified foreign matter stays in the toner reservoir layer for a while, but is eventually pushed out of the reservoir layer by the force of the toner that enters later. The pushed toner is effectively collected by a suction fan that covers the cleaning unit. This structure can be realized by referring to Japanese Utility Model Publication No. 60-13563 previously proposed by the applicant of the present application.
[0028]
In order to verify the concept and effect of the present invention, particularly using a magnetic recording type printer characterized by high printing durability, recording on high-quality paper with artificially adhering contaminants and evaluating the occurrence of black streaks Went. As a pollutant, mulaba, which is widely used as a mechanical material, is rubbed against the first and second high-quality white papers and recorded in advance. The cleaning unit was evaluated based on the frequency of occurrence.
[0029]
The cleaning unit used for the evaluation has the conventional counter abutting blade 102 shown in FIG. 3, the conventional leading blade 202 shown in FIG. 5, and the first embodiment shown in FIG. A cloth is applied to the eaves 1 of the first embodiment, coated paper is applied to the eaves 51 of the second embodiment shown in FIG. 4, and the eaves 51 of the second embodiment shown in FIG. There are five types. FIG. 6 is a graph showing the evaluation results described above. As shown in FIG. 6, a better result was obtained when the cleaning unit of the present invention was used than when a conventional cleaning unit was used. In the case of the cleaning unit having the leading blade 202, a toner reservoir is formed, but a favorable result cannot be obtained because the toner pressure in the toner reservoir is not increased. On the other hand, in the case of the cleaning unit provided with the eaves to which the cloth material having the mesh structure is applied, the toner is sufficiently held in the toner reservoir and the toner pressure in the toner reservoir is sufficiently increased. Results were obtained.
[0030]
The cleaning unit of the present invention is particularly effective when applied to high-speed printers and duplicators that require high durability, and is particularly effective when applied to magnetic printers that have recently attracted attention in the field of digital printing.
[0031]
【The invention's effect】
According to the present invention , the deposit can be removed from the recording medium before the deposit on the recording medium adheres to the recording medium. As a result, it is possible to reduce the occurrence of black streaks on the transfer material as the adhering matter adheres to the recording medium.
[0032]
Further , according to the present invention, it is possible to pressurize the toner and to adsorb the deposit on the recording medium to the toner.
[0033]
If the eaves are formed by a flat brush, the cleaning effect of the brush alone can be expected.
[0034]
Further, if the surface of the eaves facing the recording medium is a mesh structure, the ability of the eaves to hold the toner is improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment in which a cleaning unit of the present invention is applied to an electrophotographic recording apparatus.
FIG. 2 is an enlarged view of the cleaning unit of the first embodiment.
FIG. 3 is a view showing a conventional counter contact blade.
FIG. 4 is an enlarged view of the eaves of the second embodiment.
FIG. 5 is a view showing a conventional leading blade.
FIG. 6 is a graph showing evaluation results.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Eaves 2 ... Cleaning blade 4 ... Recording medium 8 ... Recording head 9 ... Developing device 10 ... Transfer device 12 ... Transfer material

Claims (3)

A latent image is formed on a rotating drum type recording medium, the latent image is toner developed to form a toner image, the toner image is transferred to a transfer material, and the toner remaining on the recording medium is removed by a cleaning unit. In a cleaning unit used for a magnetic photographic recording apparatus or an electrophotographic recording apparatus that removes and collects the removed toner by a suction fan ,
A counter-contact cleaning blade;
The cleaning blade is attached to the surface opposite to the recording medium facing surface, extends substantially parallel to the cleaning blade and contacts the recording medium, and toward the upstream side in the moving direction of the recording medium Comprising an eaves of an elastic member protruding from the cleaning blade,
A toner reservoir is formed in a space surrounded by the cleaning blade, the eaves, and the recording medium, and includes at least an oily thin film by effectively pressurizing the toner flowing into the toner reservoir with respect to the recording medium. removed before type recording medium foreign matter adsorbed on the toner staying in the toner reservoir,
Thereafter, the toner adsorbing the foreign matter is pushed out of the toner reservoir and collected . The cleaning unit according to claim 1, wherein the eaves are formed by a planar brush . The cleaning unit according to claim 1 , wherein a surface of the eaves facing the recording medium has a mesh structure .

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