JPS6138467B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid guide method and apparatus, and in particular, to a liquid guide method and apparatus, and in particular, to a liquid guide method and apparatus for recovering waste liquid generated when cleaning an image bearing member to be reused, such as an electrophotographic apparatus using a liquid phenomenon transfer method. The present invention relates to a method and device for guiding liquid to a certain area.

Conventionally, in an electrophotographic apparatus, when an electrostatic image carried on an image carrier is developed and transferred using a liquid developing agent, it has been necessary to clean and remove the liquid remaining on the image carrier.

Further, after developing and transferring the electrostatic image on the image bearing member, a cleaning liquid may be used to clean residual developer, and needless to say, liquid removal is necessary in this case as well.

In order to recover such cleaning removal liquid, for example, the removal liquid is guided downward along the side surface of the photoreceptor drum so that it can be stored in a developing device disposed below the photoreceptor drum, or, A liquid guide method has been used, such as collecting the liquid through a groove provided at the side end of the photoreceptor drum.

The method of guiding the liquid along the side surface of the photosensitive drum is as shown in FIG.

The photosensitive drum 1 has circular side plates 1 ₁ , 1 ₂ at both ends.
The disc-shaped side plates 1 ₁ , 1 ₂ are rotatably supported by a support shaft 2 that engages with the center hole.

3 ₁ and 3 ₂ are bearings provided in the center hole.

A cleaning means using an elastic cleaning blade 4 is provided by rotating the photosensitive drum 1 in the direction of arrow a and placing it at a position after the development and transfer.

4 ₁ and 4 ₂ are protrusions provided at both ends of the elastic cleaning blade 4 to prevent liquid from flowing around the surface of the cleaned photoreceptor.

By such a cleaning means, the developer remaining on the photoreceptor drum 1 or the cleaning liquid supplied by the cleaning section is removed laterally from the surface of the photoreceptor drum 1. The row of small arrows in the figure schematically shows the flow of the removed liquid.

As shown in the figure, the removal liquid flowing down from the surface of the photoreceptor drum along the wall surface of the side plate spreads along the wall surface of the rotating side plate, and a portion of it again enters the surface of the photoreceptor drum from the end of the side wall. When such intrusion of the removal liquid onto the photoreceptor drum occurred, it adversely affected the image to be subsequently formed on the photoreceptor.

Further, since the removal liquid that has fallen along the side plate wall surface is spread out, it falls from a wide area of the lower edge of the side plate wall surface.

Therefore, in order to collect the falling removal liquid, a receiving part 5 must be placed under the wide falling area on the lower edge of the side wall.
It is essential to prepare.

Since the receiving part arranged in this way has a wide receiving port, the evaporation of the liquid received is large. When the removal liquid is reused as a developer, the developing device is provided with an opening for receiving the falling liquid, which increases the amount of evaporation of the developer.

In addition, there was a risk that the flowing liquid that had spread inside the side wall would flow into the vicinity of the bearing of the support shaft, impeding smooth rotation and further impairing the durability of the bearing.

On the other hand, a method for collecting photosensitive drums by forming grooves on the side ends thereof has been implemented, for example, as shown in the second figure.

In the illustrated apparatus, the same means as in FIG. 1 are designated by the same numbers. Side grooves 6 ₁ and 6 ₂ are provided on the circumferential surfaces of thick circular side plates 1' ₁ and 1' ₂ that sandwich the photosensitive drum 1 from both sides.

In such a configuration, the liquid flow flows along the side groove 6 along the elastic cleaning blade 4, as shown by the row of small arrows.
₁ , 6, _{and 2} , the removal liquid scatters and falls over a wide range from the groove section approximately below the horizontal plane including the support shaft. This wide range of liquid scattering becomes more pronounced as the rotational speed of the photosensitive drum is increased, making it difficult to utilize it for high-speed image reproduction.

Since the removal liquid scatters and falls over a wide range, a wide receiving means is required to accommodate the falling area.

In addition, this method is different from the above-mentioned method in that there is no risk of the removal liquid spreading on the side plate wall surface, so there is no risk of hindering rotation, but the removal liquid is applied to the groove near the peripheral edge of the photoreceptor drum. In some cases, there is a risk that the liquid may flow out from within the groove onto the surface of the photoreceptor drum.

Therefore, in this case as well, similar to the method described above, the subsequent reproduced image was adversely affected.

The present invention has been made in view of the above-mentioned points, and the present invention has been made in view of the above-mentioned points.
It is an object of the present invention to provide a method and device for guiding a liquid to a recovery section without causing scattering to the surrounding area.

That is, the present invention prevents the liquid removed from the surface of the image bearing member from scattering over a wide area around the image bearing member, prevents the liquid removed from entering the surface of the image bearing member, and furthermore prevents the liquid removed from the surface of the image bearing member from scattering over a wide area around the image bearing member. The present invention provides a liquid guide method and device that prevents liquid from flowing into the vicinity of a bearing portion of a movable support shaft and allows liquid to be guided to a recovery portion in a good manner.

In order to achieve the above object, the present invention has the following configuration. That is, a cylindrical image carrier that rotates around a rotation axis, a cleaning device that removes liquid adhering to the circumferential surface of the image carrier, and a cleaning device that removes the liquid removed by the above cleaning near the outer wall circumferential surface of the guide substrate described below. and a guide substrate that is provided at an end of the cylindrical image carrier and rotates about the rotation axis and guides the liquid guided by the guide member, and the guide substrate is provided at the end of the cylindrical image carrier and guides the liquid guided by the guide member. An annular groove formed on the circumferential surface of the shaft, an outer wall circumferential surface provided along the outer circumference of the groove and having an inclination such that the higher the part, the greater the distance from the rotating shaft, and the inner wall of the groove. A liquid guide device characterized by having an inner wall circumferential surface provided along the circumference.

Hereinafter, details of the present invention will be explained by way of specific examples with reference to the drawings.

FIG. 3 is a schematic view of the liquid guide device according to the present invention mounted on a photosensitive drum. FIG. 4 is a front view thereof, and FIG. 5 is a sectional view taken along line AB.

The liquid guide device has a circular substrate 7 which is a guide substrate having approximately the same diameter as the photoreceptor drum 1, and is engaged with a side end of the photoreceptor drum 1.

A center hole 8 is bored in the center of the substrate 7, through which the support shaft 2 of the photoreceptor drum 1 passes. In the illustrated apparatus, the substrate also serves as a side support plate for the photosensitive drum, and a bearing 9 is fitted into the center hole so as to engage with the support shaft. A projecting bank 10 is formed concentrically on the circular substrate 7 so as to surround the center hole 8 thereof. The protruding embankment 1
The outer circumferential surface 0 of 0 (same as the inner wall circumferential surface) forms a slope that slopes closer to the axial center as the distance from the substrate surface increases. In addition, the inner circumferential surface Q of the protruding bank 10 forms a conversely inclined slope, and reaches the bearing portion. Also, its top surface P
is substantially parallel to the surface of the circular substrate.

On the other hand, a groove 11 is provided concentrically around the protruding levee 10 on the substrate 7 between the protruding levee 10 and the outer peripheral edge thereof. Inner wall peripheral surface R near the central axis of the groove 11
is configured to form the same sloped surface that is an extension of the outer circumferential surface 0 of the protruding embankment, and can be regarded as a part of the outer circumferential surface 0R of the protruding embankment.

The outer wall circumferential surface T near the outer circumferential edge of the groove 11 is
It forms a slope that slopes away from the outer peripheral edge as it moves away from the substrate surface. In the illustrated example, the groove bottom surface S is configured to be substantially parallel to the surface of the circular substrate.

On the other hand, the elastic cleaning blade 12 that cleans the surface of the photoreceptor drum 1 has an end extending from the surface of the photoreceptor drum 1 to the periphery of the circumferential surface of the circular substrate. A protruding ear member 13, which is a guide member, is provided that protrudes along the U-plane up to the vicinity of the outer wall circumferential surface T of the groove.

FIG. 6 is a partially enlarged view showing the elastic cleaning blade set on the photoreceptor.

The protruding ear member 13 provided at the end of the elastic cleaning blade 12 has a tip ₁₃₁ shaped like a blade.

The blade-like end is disposed approximately along the outer wall edge where the outer wall circumferential surface T intersects with the substrate circumferential surface U surface.

The effects of the apparatus configured as described above will be explained below.

As the photoreceptor drum 1 rotates, an electrostatic latent image is formed on the photoreceptor, and the remaining liquid after liquid development and transfer reaches the cleaning blade position.

Further, in order to promote the cleaning action, liquid may be newly supplied at the cleaning position.

In either case, the remaining liquid on the photoreceptor is removed by the elastic cleaning blade 12 and flows out along the blade toward the end of the photoreceptor. The removed liquid flowing out to the side end flows down the u-plane between the outer peripheral edge on the circular substrate 7 and the outer wall peripheral surface T of the groove along the protruding ear member 13.

The liquid flowing down along the protruding ear member 13 reaches the tip ₁₃₁ of the protruding ear member 13 and flows into the outer wall circumferential surface T. In order to maintain a good flow of liquid from the circumferential surface U of the circular substrate to the circumferential surface T of the outer wall of the groove, the inclination of the circumferential surface of the outer wall is effective. That is, the inclination angle θ ₁ , (fifth
2), the droplet (or liquid flow) that reaches the edge of the outer wall can quickly contact the circumferential surface of the outer wall before falling from the edge of the outer wall. This is because the droplet (or liquid flow) that comes into contact with the outer wall circumferential surface moves along the outer wall surface due to its surface tension. In particular, since the tip ₁₃₁ is disposed close to the outer edge of the outer wall circumferential surface T and does not protrude onto the groove, the liquid that has once flowed into the outer wall circumferential surface T may be contaminated if it were to protrude. There is no risk of a wraparound flowing through the protrusion and flowing again to the u-plane. The liquid flowing from the tip ₁₃₁ of the protruding ear member to the outer wall circumferential surface T reaches the outer wall circumferential surface or the groove bottom surface S, and most of the liquid flows down along the bottom surface S. Then, some of the liquid that has reached the groove bottom surface S further reaches the inner wall circumferential surface R of the projecting embankment 10 and flows down.

Even if the flowing removed liquid reaches the inner wall circumferential surface 0R, it does not reach the top surface P of the projecting bank 10. Therefore, there is no risk of liquid entering the bearing 9 of the support shaft 2 surrounded by the projecting embankment 10.

The fact that there is no fear of liquid intrusion will be explained in more detail. The projecting bank 10 rotates together with the photoreceptor drum, and in an area above a horizontal plane that includes the rotational center axis of the inner wall circumferential surface R of the projecting bank 10, an object on the inner wall circumferential surface R has an upward direction that can resist gravity. Centrifugal force acts on it. Therefore, an upward centrifugal force acts on the liquid that has reached the inner wall circumferential surface R.

FIG. 7 schematically explains the behavior of the liquid L in a region where an upward centrifugal force acts.

That is, the liquid L guided to the peripheral surface R of the inner wall of the protruding embankment contains:
A downward gravitational force F ₁ and an upward centrifugal force F ₂ act. However, since the inner wall peripheral surface R forms a slope with an inclination of θ ₂ , the gravitational force F ₃ and the centrifugal force F ₄ parallel to the slope act on the liquid L in mutually opposite directions. I will do it. Therefore, the liquid L is subjected to a gravitational force that tends to move it down the slope, and a centrifugal force that tends to move it up the slope. by the way,
In addition to these forces, intermolecular force F′ that acts between the outer circumferential surface and the liquid, adhesive force F″ depending on the viscosity of the liquid, etc. act on the liquid. However, these forces act on the liquid due to the component of gravity. Even if it impedes the flow, it does not promote it in any way.

Therefore, by setting an appropriate degree of inclination θ ₂ according to the rotational speed, it is possible to rotate and convey the liquid L without dropping it from the inner wall circumferential surface R.

Further, the liquid L may move from the inner wall circumferential surface R to the groove bottom surface S. Even on this groove bottom surface S, the relationship between the forces acting on the liquid L remains the same. However, since the groove bottom surface S is parallel to the direction of gravity and also parallel to the direction of rotation, the liquid is affected by gravity _F1 and centrifugal force rather than each component force.
Each of F ₂ is all in effect.

In this way, the liquid L is applied to the inner wall circumferential surface R or
It is moved along the groove bottom surface S.

On the other hand, when the inner wall circumferential surface R of the projecting embankment 10 reaches the direction of the horizontal plane including the rotation center axis, a resultant force _F5 of centrifugal force and gravity acts on the liquid L, as shown in FIG. On the other hand, the liquid L is adhered and restrained to the inner wall circumferential surface R. A resultant force F ₆ of surface tension and adhesive force acts perpendicularly to the inner wall circumferential surface R. Therefore, the liquid L is eventually moved along the inner wall circumferential surface R to the groove bottom surface by the resultant force _F7 .

At this time, it is important that the inclination θ ₂ of the outer circumferential surface is a positive value when measured clockwise from a reference line parallel to the central axis shown in the figure.

That is, as long as the inclination θ ₂ is positive, the liquid is sent to the bottom side of the groove, and there is no risk of splashing. However, if it is zero, it will not be able to move from the inner wall circumferential surface R and will be rotated, and if the resultant force of gravity and monkey mind force overcomes the restraining force such as adhesive force, it will scatter. In addition, if the value is negative, the liquid will move toward the top surface of the protruding embankment, and there is a risk that the liquid will scatter from the top surface to the surrounding area.

When the inner wall circumferential surface R reaches the lowest point, the directions of gravity and centrifugal force coincide, so liquid scattering is most likely to occur. However, in the device configuration of this embodiment,
Since the liquid is moved outside the inner wall circumferential surface R as described above, there is almost no remaining liquid on the outer circumferential surface when passing the lowest point B, so there is almost no risk of liquid scattering.

On the other hand, the liquid L that has reached the groove bottom surface S from the inner wall circumferential surface R
crosses the groove bottom surface S and reaches the groove outer wall circumferential surface T. At the groove outer wall circumferential surface T, most of the resultant force of the gravity and centrifugal force applied to the liquid L is reduced by the normal force, and only the component force along the outer wall circumferential surface acts as a moving force of the liquid.

Then, the liquid whose speed is regulated in this way drips quietly downward near the bottom B of the outer periphery or near the bottom D on the rising side. Since this drip area is limited to an extremely narrow area, the collection opening of the collection receiver 14 can also be made extremely small. In addition to providing a dedicated device, the collection receiver can naturally utilize a liquid developing device since it is usually disposed below the photosensitive drum.

In addition, the liquid whose speed is regulated in this way has no risk of invading the surface of the photoreceptor from the peripheral surface of the circular substrate beyond the peripheral edge of the circular substrate, so there is no risk of deteriorating the image quality.

EXAMPLE The effects of a specific example apparatus based on the present invention were confirmed using a photosensitive drum with a drum diameter of 136 mm and a circumferential speed of 200 mm/sec.

As a specific example device of the present invention, the diameter of the circular substrate forming the guide portion is 136 mm, which is the same diameter as the drum, the width of the U surface is 5 mm, the width of the P surface is 5 mm, the depth l of the groove is 7 mm, and the substrate surface The height of the protruding embankment is 10 mm, the slope of the outer wall of the groove is tanθ ₁ = 2/7, and the slope of the outer peripheral face of the protruding embankment is tan
This is the case when θ ₂ =1/10.

An elastic cleaning blade is brought into contact with the surface of the photoreceptor drum rotating at the circumferential speed shown above, and
The cleaning waste liquid is guided to the end protruding ear member. When the tip of the protruding ear member is moved from a position that coincides with the outer wall edge to a position approximately 2 mm away from the peripheral surface u of the substrate, the removed liquid flowing down along the protruding ear member will not be guided to the groove. It was good and warm. The liquid guided into the groove flows downward along the groove without invading the bearing over the protruding embankment or scattering to the surrounding area, reaching approximately point B (shown in Figure 4), and reaching around the outer wall of the groove. The liquid flowed out of the groove from the surface and was able to be stored in the liquid storage tank of the developing device located below.

As described above in detail in the specific examples, the present invention guides the liquid removed from the surface of the image carrier by the cleaning means to the vicinity of the outer wall circumferential surface of the guide substrate using the guide member, and the slope of the outer wall circumferential surface is Let it be transmitted and guide it to the groove. Then, by guiding the liquid downward along the groove while preventing the liquid from entering the bearing part by the inner wall circumferential surface, the liquid is caused to travel along the slope of the outer wall circumferential surface and fall out of the guide board. This makes it possible to guide the liquid removed from the image carrier to the recovery section without causing any scattering.

Further, according to the present invention, since the liquid does not spread over a wide area when being led to the recovery section, it is possible to transfer the liquid in a limited area.

Further, in the present invention, when guiding the removed liquid, there is no fear of the liquid entering into movable parts such as the support shaft of the image carrier.
Enables liquid processing without causing surrounding contamination,
Moreover, it does not interfere with the long-life and stable operation of the applied equipment.

[Brief explanation of the drawing]

1 and 2 are perspective views illustrating a conventional liquid guiding method. FIG. 3 is a perspective view illustrating the liquid guide device according to the present invention, FIG. 4 is a front view, FIG. 5 is a cross-sectional view taken along FIG. 4 A-B, and FIG. FIG. 6A is a partially enlarged view of the abutted end of the photoreceptor, FIG. 6A is a front view thereof, and FIGS. 7 and 8 are schematic diagrams illustrating the force acting on the liquid on the outer peripheral surface of the protruding bank. In the figure, 1... photoreceptor drum, 2... spindle, 3
₁ , 3 ₂ ... Bearing, 4 ... Elastic cleaning blade, 5 ... Receiving portion, 6 ₁ , 6 ₂ ... Side groove.

Claims (1)

[Scope of Claims] 1. A cylindrical image carrier that rotates around a rotation axis, a cleaning device for removing liquid attached to the circumferential surface of the image carrier, and a guide for removing the liquid removed by the cleaning device. a guide member that guides the liquid to the vicinity of the outer wall circumferential surface of the substrate; and a guide substrate that is provided at an end of the cylindrical image carrier and rotates together with the image carrier about the rotation axis and guides the liquid guided by the guide member. The guide substrate has an annular groove formed around the rotation axis, and an inclination provided along the outer periphery of the groove such that the higher the part thereof, the greater the distance from the rotation axis. 1. A liquid guide device comprising: an outer wall circumferential surface having a groove, and an inner wall circumferential surface provided along an inner circumference of the groove. 2. The liquid guide device according to claim 1, wherein the cleaning means is a cleaning blade. 3. The liquid guide device according to claim 2, wherein the guide member is a protruding ear member provided at a side end of the cleaning blade.