KR100433540B1 - Metering roller for liquid image developing system and liquid image developing system using it - Google Patents

Abstract

The metering roller of the disclosed wet image development system includes means for preventing wraparound in which unnecessary developer is introduced and contaminates a uniformly formed toner layer by blocking the flow of the developer flowing to both sides of the development roller. It is done. By providing such a metering roller, it is possible to block unnecessary inflow paths of the developer and supply a uniformly formed toner layer to the developer, and to obtain a print image of a constant density at all times even if the toner concentration of the developer changes.

Description

Metering roller for wet image development system and wet image development system employing it {Metering roller for liquid image developing system and liquid image developing system using it}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metering roller for regulating the amount of toner adhered to a developing roller, and more particularly to a metering roller having a function of preventing wraparound.

In general, a wet imaging system scans light on a photoconductor to form an electrostatic latent image corresponding to a desired image, and colorizes the liquid carrier by a developing roller to access the photoconductor. A system for supplying and developing a developer dispersed therein, comprising: metering means for regulating a uniform amount of toner adhered to the developing roller for stable development.

Figure 1a schematically shows a wet image development system equipped with a conventional metering means.

As shown in the drawing, a wet image development system equipped with a conventional metering means includes a developing roller 102 which rotates to face the photosensitive member 106 while partially submerged in a developer in the developing container 101, and the developing roller. Deposition means 103 for adhering toner to 102 and metering means 104 provided in contact with the outer circumferential surface of the developing roller 102 are included.

Toner is attached to the outer circumferential surface of the developing roller 102 by the force of the electric field applied to the deposit means 103 and the developing roller 102, and the developing roller 102 rotates to the metering means. The uniform toner layer formed is supplied to the developing NIP facing the photosensitive member 106 and developed into the photosensitive member 106. Strictly speaking, the liquid carrier is attached together with the toner, but the liquid carrier is evaporated in the process of fixing on paper (not shown), and it is important to control the amount of the toner because it is the toner to form an actual image.

In general, in the case of using a developer having a constant toner concentration, a constant amount of toner can always be attached to the developing roller 102 if the electric field applied to the deposit means 103 is constant. However, in the case of using a developer in a wide concentration range of 2 to 40% solids, the amount of toner adhered depends on the toner concentration. In fact, recently, there is a need for a system that can use such a wide range of developer.

Therefore, the deposit means 103 attaches a sufficient amount of toner to the developing roller 102 irrespective of the toner concentration of the developer, and then removes the excessively attached toner so that only a certain amount of toner is developed. The supply process is required, which is called metering.

Figure 1b briefly shows an example of using a metering blade as the metering means.

As shown, the metering blade 104b is installed in contact with the outer circumferential surface of the developing roller 102. As the developing roller 102 rotates the developing roller 102 with a sufficient amount of toner by the deposit means 103, the metering blade 104b rubs against the developing roller 102 to scrape off the excessively attached toner. By collecting to 101, only a uniform amount of toner is supplied to the developer.

By the way, while the metering blade 104a has an advantage in that the structure is simple, the toner is torn due to excessive friction with the developing roller 102 and thus there is a problem in that a uniform toner layer is not formed.

In order to solve this problem, a metering roller as shown in Fig. 1C has been proposed as a metering means.

As shown, the metering roller 104c is provided in contact with the outer circumferential surface of the developing roller 102. As the metering roller 104c contacts the developing roller 102 and rotates in the same direction, it blocks the toner that is excessively attached by the contact pressure to recover the developing container 101, and develops only a uniform amount of toner. Will be supplied by As described above, when the metering roller 104c is used as the metering means, the metering roller 104c rotates together with the developing roller 102, and thus the toner is used as in the case of using the metering blade 104b. Tearing does not occur.

However, as shown in FIG. 2, the developer blocked by the metering roller 104c is pushed to both ends along the contact line between the developing roller 102 and the metering roller 104c and then the developing roller 102. A phenomenon occurs that flows into the already metered toner layer along the side of the cuff, which is called wraparound. In FIG. 2, the developing roller 102 and the metering roller 104c have the same length, but the length of the developing roller 102 is longer, as well as the length of the metering roller 104c. Wrap-around occurs even longer.

Such wrap-around damages the toner layer uniformly formed by the metering roller, thereby deteriorating the effect of the metering, and by supplying a non-uniform toner layer to the developer, the density of the printed image becomes uneven. Therefore, a countermeasure for preventing this is necessary.

SUMMARY OF THE INVENTION The present invention has been made in view of the above necessity, and an object thereof is to provide a metering roller having a means for preventing wraparound in a wet image development system.

Is a schematic illustration of a wet image development system equipped with a conventional metering means.

FIG. 1B shows an example of using a metering blade as the metering means in FIG. 1A; FIG.

FIG. 1C shows an example of using a metering roller as the metering means in FIG. 1A; FIG.

Figure 2 is a perspective view showing the wrap around phenomenon.

3 shows a metering roller according to a first embodiment of the present invention.

4 is a view showing a metering roller according to a second embodiment of the present invention.

5 is a view showing a metering roller according to a third embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

102 ...... Developer roller 103 ...... Deposit means

104b ..... meter ring blades 104c ..... meter ring rollers

301 ...... Protrusion formed integrally with the metering roller

401 ...... ring-shaped member

501 ... engagement groove of ring-shaped member

The metering roller of the present invention for achieving the above object is characterized in that it comprises means for preventing wraparound in which the developer flows along the left and right sides of the developing roller to contaminate the toner layer formed uniformly.

The wrap-around prevention means is formed integrally with the cylindrical portion of the metering roller and has a protrusion to be in close contact with the left and right sides of the development roller, and the ring-shaped member is in contact with the left and right sides of the development roller. There may be a variety of methods, such as coupled to the cylindrical portion of, in particular, when engaging the ring-shaped member it is also possible to form a coupling groove in the cylindrical portion of the metering roller.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 shows a metering roller according to a first embodiment of the invention with means for preventing wraparound.

As shown, the protrusion 301 integrally formed with the cylindrical portion 302 of the metering roller 300 is in close contact with the left and right sides of the developing roller 102. In general, the developing roller 102 uses a conductive rubber material, and the metering roller 300 uses a metal material. Therefore, in forming the protrusion 301, the gap D2 between the inner surface 301a of the protrusion 301 is slightly smaller than the gap D1 of the left and right side surfaces 102a of the developing roller 102. The side surface 102a of the roller 102 is elastically in close contact with the inner surface 301a of the protrusion 301 to maintain airtightness.

The metering roller 300 having the wrap-around prevention means rotates in contact with the developing roller 102 to which a sufficient amount of toner is attached by the deposit means 103 while By regulating and recovering to the developing container 101, a uniform toner layer is formed. At this time, even if the toner to be regulated by the metering roller 300 to be recovered to the developing container 101 flows toward the left and right sides 102a of the developing roller 102 together with the liquid carrier, the protruding portion 301 Since the toner blocks the flow, the toner layer uniformly formed by the metering can be supplied to the developer without being damaged.

4 shows a metering roller according to a second embodiment of the present invention.

As shown, a ring-shaped member 401 is coupled to the left and right of the cylindrical portion 402 of the metering roller 400. At this time, if the distance (D2) of the inner surface (401a) of the ring-shaped member 401 is slightly smaller than the distance (D1) of the left and right side portions (102a) of the developing roller 102, the rubber material is conductive The developing roller 102 is elastically in close contact with the left and right sides 102a to maintain airtightness.

The ring-shaped member 401 may use a variety of materials, it is preferable to use a rubber material. By using the elastic force of the rubber material can increase the adhesion to the left and right sides (102a) of the development roller 102, as well as coupling to the cylindrical portion 402 of the metering roller 400 without using a separate fastening member can do.

Figure 5 shows a metering roller according to a third embodiment of the present invention.

As shown, in joining the ring-shaped member 503 as a means for preventing wraparound, the inner surface 503a of the ring-shaped member 503 is left and right sides 102a of the developing roller 102. Coupling grooves 501 are formed on the left and right sides of the cylindrical portion 502 of the metering roller 500 in close contact with the position. This provides the advantage of not having to adjust the position after the combination. In this case, it is preferable that the ring-shaped member 503 is made of a material capable of elastic deformation, and in particular, a rubber material is used.

By providing a metering roller provided with such wraparound prevention means, a uniform toner layer can be formed and supplied to the developing wafer.

As described above, according to the metering roller according to the present invention, the following effects can be obtained.

First, it is possible to form a uniform toner layer by preventing unnecessary developer flowing through the left and right sides of the developing roller from flowing into the toner layer after the metering process.

Second, since a uniform toner layer is supplied to the developer, a printed image of a constant density can always be obtained even if the toner concentration of the developer changes.

It is to be understood that the invention is not limited to that described above and illustrated in the drawings, and that more modifications and variations are possible within the scope of the following claims.

Claims (8)

In a metering roller of a wet imaging system, which rotates in contact with a developing roller and uniformly limits the amount of toner excessively attached to the developing roller, Metering roller of the wet image development system, characterized in that it is in close contact with the both sides of the development roller and the means flowing to the left and right sides along the contact line with the developing roller to prevent wrap-around. The method of claim 1, The means for preventing the wrap-around, the metering roller of the wet image development system, characterized in that formed integrally with the cylindrical portion of the metering roller and provided with a protrusion to be in close contact with the left and right sides of the developing roller. The method of claim 1, The metering roller of the wet image development system, characterized in that the means for preventing the wrap-around includes a ring-shaped member coupled to the cylindrical portion of the metering roller to be in close contact with the left and right sides of the developing roller. The method of claim 3, wherein Metering roller of the wet image development system, characterized in that the engaging groove for engaging the ring-shaped member in the cylindrical portion of the metering roller. A photosensitive member, a developing roller for supplying toner to an electrostatic latent image formed on the photosensitive member while rotating facing the photosensitive member, and a metering roller for controlling the amount of toner attached to the developing roller while rotating in contact with the developing roller; In the wet imaging system, The metering roller is in close contact with both sides of the developing roller, the wet image development system characterized in that it comprises a means for preventing the wrap-around by blocking the developer flowing to the left and right sides along the contact line with the developing roller. The method of claim 5, wherein And a means for preventing the wrap-around is formed integrally with the cylindrical portion of the metering roller and has a protrusion to be in close contact with the left and right sides of the developing roller. The method of claim 5, wherein And said means for preventing wraparound comprises a ring-shaped member coupled to the cylindrical portion of the metering roller to be in close contact with the left and right sides of the developing roller. The method of claim 7, wherein And a coupling groove for coupling the ring-shaped member to the cylindrical portion of the metering roller.