JPH0523436B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a cleaning device, and more particularly, to a cleaning blade that removes toner remaining on the surface of a rotationally driven toner image carrier by pressing its tip against the surface of the toner image carrier. The present invention relates to a cleaning device having a cleaning device.

Prior Art The cleaning device of the above type is often used, for example, in a powder image transfer type electrophotographic copying machine (PPC) to remove toner remaining on the surface of an electrophotographic photosensitive drum that functions as a toner image carrier. . Due to the structure of the copying machine itself, it is often necessary to install it almost above the photoreceptor drum, but a problem that can arise in this case is that the removed toner is affected by the force of gravity on the photoreceptor drum. Since the toner acts in a direction toward the surface of the toner, a simple toner collection mechanism using gravity cannot be used, and moreover, it is difficult to collect the toner.

Since toner always remains on the surface of the photoreceptor drum located at the tip edge of the blade, toner may solidify in that area, toner may become clogged between the blade and the surface of the photoreceptor drum, or it may leak onto the surface of the photoreceptor drum. Toner filming and the like are likely to occur, and as a result, there is a possibility that cleaning defects may occur.

Such problems have already been experienced.

Therefore, as a method to solve these problems, a method is proposed in which the toner present on the surface of the photoreceptor drum located at the tip edge of the blade is forcibly sucked and collected using a suction, as disclosed in Japanese Patent Application Laid-Open No. 53-122430. It has been proposed in By the way, according to this proposed method, although it is possible to solve the above problem in principle, from a practical point of view, a relatively large suction means is required.
Furthermore, when the cleaning device is continuously used, the suction force decreases due to toner clogging in the air suction port, etc., which ultimately leads to problems similar to those described above.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a cleaning device which solves the above-mentioned problems without causing the above-mentioned inconveniences, and which is excellent in practical use.

SUMMARY OF THE INVENTION The gist of the present invention is that the cleaning device according to the present invention includes the following members and means:
a cylindrical member that is provided along the tip of the blade and has a spiral air outlet on its circumferential surface; b. air is directed from inside the cylindrical member toward the tip of the blade through the air outlet; air blowing means for blowing; c cylindrical member rotating means for rotating the cylindrical member in order to displace the air blowing position by the air blowing means in a direction along the tip of the blade; d a circumferential surface of the cylindrical member. e) a toner removing mechanism that removes the toner adsorbed to the circumferential surface of the cylindrical member; The above objective can be achieved.

Embodiment Hereinafter, an embodiment of the cleaning device according to the present invention will be described with reference to FIGS. 1 to 4. Note that the cleaning device shown in the embodiments is shown as a device for cleaning the surface of the photoreceptor to which residual toner is attached.

In FIG. 1, a blade cleaning device 2 is provided facing the surface of an electrophotographic photosensitive drum 1 that is rotated in the direction of arrow a with residual toner attached to the surface. The surface of the body drum 1 is successively cleaned. Here, the state shown in FIG. 1 is the state when the cleaning device 2 is fixed at an operating position inside a powder image transfer type electrophotographic copying machine (not shown).

The cleaning device 2 has inside thereof a cleaning blade 3 made of polyurethane rubber material. This blade 3 is connected to the photoreceptor drum 1.
By pressing the tip against the surface of
It functions to remove residual toner from the surface of the photosensitive drum 1, and is supported so as to be able to swing toward and away from the surface of the photoreceptor drum 1 by a blade holding function 5 that is swingable around a blade swing shaft 4. On the other hand, there is a blade biasing mechanism stretched between a pin 7 fixed to a blade holding base 6 that constitutes a part of the blade holding mechanism 5 and a pin 8 fixed to the casing of the cleaning device 2. Due to the action of the spring 9, when the cleaning device 2 is in the operating position, it is urged in the direction of the arrow b about the shaft 4, that is, to the pressure contact position against the surface of the photoreceptor drum 1 shown in FIG. .

Further, the blade 3 is attached to a blade holding plate 10, and the blade holding plate 10 is rotatably attached to the upper surface of the blade holding base 6 by a screw 11 provided at the center in the longitudinal direction of the blade. It is being Therefore, the blade 3 is rotatable about the screw 11 on the upper surface of the blade holding base 6.

Incidentally, a toner collection roller 12 is provided near the tip of the blade 3 and on the upstream side in the direction of movement of the photosensitive drum 1, that is, on the side opposite to the direction of arrow a. As shown in detail in FIGS. 2 and 3, this roller 12 is composed of an inner cylinder 13 made of synthetic resin and an outer cylinder 15 made of conductive metal, and the longitudinal direction of the roller 12 is the same as that of the blade 3. It is provided along the tip. Here, the inner cylinder 13 and the outer cylinder 15 are relatively rotatable in the circumferential direction, and the inner cylinder 13 is fixed in a stationary state at the position shown in FIGS. 1 and 2, while the outer cylinder 15 is adapted to be rotated in the direction of arrow c by a drive mechanism (not shown) when the cleaning device 2 is operated.

As shown in detail in FIG. 3, the inner cylinder 13 has a ventilation port 14 connected to an air blowing mechanism (not shown) at one end thereof, and a plurality of air blowers on its circumferential surface. An outlet 13a is bored along its longitudinal direction. And this air outlet 1
3a is positioned opposite the tip of the blade 3, as shown in FIG. Also,
As shown in detail in FIG. 3, the external cylinder 15 has a spiral air outlet 15a on its circumferential surface.
is filled with a porous material 16 made of hard sponge, and the peripheral surface of the toner collection roller 12 is finished into a uniformly curved surface with no irregularities.

Based on such a configuration, when the outer cylinder 15 of the toner collection roller 12 is rotationally driven during operation of the cleaning device 2, the inner cylinder 1 is rotated by the air blowing mechanism.
The air blown into the inside of the blade 3 passes through the matching portion of the air outlet 13a and the spiral air outlet 15a, and is blown from the inside of the toner collection roller 12 toward the tip of the blade 3. becomes. At this time, the air blowing portion is limited to a portion along the longitudinal direction of the toner collection roller 12, that is, the matching portion of the air blowing ports 13a and 15a.
The matching portion is displaced along the longitudinal direction of the toner collection roller 12 in the direction of arrow d.
Therefore, as the outer cylinder 15 is rotated, the air blowing position relative to the tip of the blade 3 is sequentially displaced in the direction along the tip, and each time the outer cylinder 15 is rotated once, the tip of the blade 3 is The air blowing is performed evenly over the entire length along. Such a configuration is very effective in preventing the blowing mechanism from increasing in size.

On the other hand, the outer cylinder 1 of the toner collection roller 12
5 is connected to a bias power supply 17. The bias power supply 17 has the function of applying a charge for toner adsorption to the external cylinder 15 forming the outer peripheral surface of the toner collection roller 12. Specifically, the charging polarity of the toner is determined by the bias power supply 17. A bias voltage of opposite polarity is applied to the outer cylinder 15.
Here, as shown in FIG. 1, since the toner collection roller 12 is disposed opposite to the surface of the photoreceptor drum 1 in an uncleaned state with a small gap maintained, the surface of the photoreceptor drum 1 is Prior to being subjected to the cleaning action by the blade 3, most of the residual toner To on the top is electrostatically attracted onto the circumferential surface of the toner collection roller 12 in the minute gap, thereby being removed from the surface of the photoreceptor drum 1. That will happen. Further, as shown in FIG. 2, the toner To removed from the surface of the photoreceptor drum 1 by the blade 3 is removed from the air outlet 13a,
The toner is transported in a floating state in the direction of the arrow in the figure on the air flow blown from inside the toner collection roller 12 via the toner collection roller 15a. The toner To is also electrostatically attracted onto the circumferential surface of the toner collection roller.

The toner electrostatically attracted onto the circumferential surface of the toner collection roller 12 is conveyed in the direction of arrow c as the external cylinder 15 is driven to rotate, and the toner collection roller 12 is provided with its tip in pressure contact with the circumferential surface of the external cylinder 15. scraper 1
8, the toner is removed from the circumferential surface of the toner collection roller 12, dropped into the toner collection casing 19, and collected into the casing 19. Then, by a toner transport mechanism (not shown) provided in the casing 19, the toner is discharged out of the cleaning device 2 and guided into a bottle for toner disposal. Incidentally, an airtight flexible sealing plate 20 is attached to the casing 19, which covers the upper part of the toner collection roller 12 and regulates the flow path of the air blown to the tip of the blade 3. The leading edge is pressed against the blade 3. In addition, casing 19
An air outlet 21 is bored at one end of the
The airflow from which the floating toner has been removed is discharged to the outside of the cleaning device 2. Here, in order to improve the flow of the air, it is desirable that the air outlet 21 be connected to an air suction mechanism (not shown). in this case,
The air suction mechanism may be any mechanism as long as it improves the air flow, and does not need to have a particularly large suction force.

The above is a description of one embodiment of the cleaning device according to the present invention, but the embodiment can be modified in various ways. For example, the toner collection roller 12 is brought into rolling contact with the surface of the photoreceptor drum 1, and the external cylinder 1 is rotated using the rotational drive of the photoreceptor drum 1 as a direct drive source.
5 can be rotationally driven. However, in this case, it is desirable that the outer cylinder 15 be formed of a conductive rubber material and that its peripheral surface be covered with an insulating thin film.

In addition, apart from this, a magnet may be provided inside the toner collection roller 12, or an internal cylinder 15 may be provided with a magnet.
A magnetic attraction force may be imparted to the toner collection roller 12 by molding itself from a magnetic material and magnetizing it. In this way, when magnetic carriers are mixed in the residual toner on the surface of the photosensitive drum 1, it is possible to collect the magnetic carriers by the toner collecting roller 12, which is desirable. Alternatively, if a magnetic toner is used as the toner, it is desirable because the collection can be performed even more effectively.

Further, the outer cylinder 15 of the toner collection roller 12 is made of an insulating material, and the scraper 18 is made of an insulating material.
By selecting a material that rubs the outer cylinder 15 in a polarity opposite to that of the toner due to frictional contact with the outer cylinder 15, the circumferential surface of the toner collection roller 12 is frictionally charged to the polarity. It's okay. In this way, the installation of the bias power supply 17 can be omitted. In this case, regardless of whether the scraper 18 is also used for frictional charging, a member for frictionally charging the peripheral surface of the toner collection roller 12 is installed separately from the scraper 18 so as to be in frictional contact with the peripheral surface. Also good.

Furthermore, as shown in FIG. 4, instead of the external cylinder 15, a mesh-shaped conductive metal cylinder 22 is used.
It is also possible to use a toner collection roller 12' comprising an outer cylinder 23 with a spiral airtight coating. Apart from this, when using the bias power supply 17, it is effective to treat the circumferential surface of the toner collection roller 12 with an insulating thin film in order to prevent the polarity of the toner electrostatically attracted to the circumferential surface from being reversed.

Effects of the Invention According to the toner collection mechanism of the cleaning device according to the present invention, the toner on the surface of the toner image carrier located at the tip edge of the blade is removed by the air flow blown from the air outlet of the cylindrical member to the tip of the blade. The toner image carrier is carried in a direction away from the surface of the toner image carrier, and at the same time, it is electrostatically attracted onto the circumferential surface of the cylindrical member. Therefore, not only is the toner collected effectively, but the toner itself does not accumulate on the surface of the toner image carrier. Note that since air blowing action is used when collecting toner by the toner collecting mechanism, no toner is transported toward the air blowing port, and therefore, there is no possibility of toner clogging of the air blowing port, etc. cannot occur,
Toner collection is performed stably despite long-term continuous use. Furthermore, a particularly large air blowing means is not required.

For these reasons, even when the cleaning device according to the present invention is installed substantially above the toner image carrier, it is possible to perform good toner cleaning.

[Brief explanation of drawings]

FIG. 1 is a drawing showing an embodiment of the cleaning device according to the present invention, FIG. 2 is an enlarged drawing showing the main parts thereof, FIG. 3 is an exploded drawing showing the structure of the toner collection roller, and FIG. The figure is an exploded view showing a deformed structure of the toner collection roller. To...Residual toner, 1...Electrophotographic photosensitive drum, 2...Cleaning device, 3...Cleaning blade, 12, 12'...Toner collection roller, 13...Inner cylinder, 13a...Air outlet,
15, 23...External cylinder, 15a, 23a...Spiral air outlet, 17...Bias power supply,
18...Scraper.

Claims (1)

[Scope of Claims] 1. A cleaning device having a cleaning blade that removes toner remaining on the surface of a rotationally driven toner image carrier by pressing its tip against the surface of the toner image carrier; a. a toner image carrier; on the upstream side in the direction of movement of the surface, at a position near the tip of the blade, and
a cylindrical member that is provided along the tip of the blade and has a spiral air outlet on its circumferential surface; b. air is directed from inside the cylindrical member toward the tip of the blade through the air outlet; air blowing means for blowing; c cylindrical member rotating means for rotating the cylindrical member in order to displace the air blowing position by the air blowing means in a direction along the tip of the blade; d toner adsorption to the cylindrical member. A cleaning device characterized by comprising: a charge applying means for applying a charge for use in the cylindrical member; and a toner removing means for removing toner adsorbed to the circumferential surface of the cylindrical member. 2. The cleaning device according to claim 1, wherein the circumferential surface of the cylindrical member is electrically conductive, and the charge applying means comprises a bias power source connected to the circumferential surface. 3. The cleaning device according to claim 1 or 2, wherein the air outlet of the cylindrical member is filled with a porous member. 4. The cleaning device according to claim 1, wherein the cylindrical member is formed by applying a spiral airtight coating to the circumferential surface of a cylinder made of a porous material. 5. The circumferential surface of the cylindrical member has an insulating property, and the charge applying means is in frictional contact with the circumferential surface,
5. The cleaning device according to claim 1, wherein the cleaning device comprises a triboelectric charging member that triboelectrically charges a peripheral surface of the cleaning device. 6. The cleaning device according to claim 5, wherein the toner removing means comprises a scraper whose tip is pressed against the surface of a cylindrical member, and the scraper also serves as the frictional charging member. 7. Claims 1 to 7, characterized in that the air blowing means has a cylindrical member which is provided in a stationary state inside the cylindrical member and has an air blowing port at a position opposite to the tip of the blade. The cleaning device according to any one of Item 6. 8. A patent characterized in that the cylindrical member is in rolling contact with the surface of the toner image carrier, and the cylindrical member rotating means rotates the cylindrical member using the rotational drive of the toner image carrier as a direct driving source. Claim 1
The cleaning device according to any one of items 7 to 7.