JP2006011070A - Cleaning apparatus for wet image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning apparatus for a wet image forming apparatus, capable of efficiently supplying carrier liquid in liquid developer to an elastic roller by forming a storage part in the longitudinal direction of the elastic roller coming in contact with a photoreceptor drum, and also, capable of attaining the miniaturization of the cleaning apparatus. <P>SOLUTION: The cleaning apparatus 60 for the wet image forming apparatus is provided with the elastic roller 62 coming in contact with the photoreceptor drum 51, and a cleaning blade 61 arranged on the downstream side of the elastic roller 62 so as to abut with the photoreceptor drum 51. The cleaning apparatus is provided with a storage cavity S for storing the carrier liquid C of the liquid developer so that the carrier liquid C may come into contact with the longitudinal direction of the elastic roller 62. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cleaning device for a wet image forming apparatus employed in a copying machine, a facsimile machine, a printer, and the like.

  In the wet image forming apparatus, a cleaning blade is brought into contact with the surface of the latent image carrier in order to collect unused liquid developer (toner and carrier liquid) on the latent image carrier such as a photosensitive drum. The liquid developer is scraped off. As described above, a method of scraping unused liquid developer on the surface of the latent image carrier with a cleaning blade is generally performed. However, in the case of development using a liquid developer composed of a toner and a carrier liquid, in a process such as development transfer, the toner concentration of the liquid developer changes, the toner concentration increases, and the viscosity of the liquid developer increases. Arise.

  The liquid developer scraped off by the cleaning blade flows smoothly through the discharge path after being scraped off when the viscosity is low. However, when the viscosity increases, the liquid developer remains attached to the cleaning blade. Alternatively, when left for a long period of time, the scraped toner accumulates at the tip of the cleaning blade and remains attached (fixed). When toner collects at the tip of the cleaning blade in this manner, there is a problem that image formation is hindered and image abnormality occurs.

In order to deal with this problem, in Patent Document 1, a cleaning blade is brought into counter contact with the photosensitive drum, and an elastic roller that is in contact with the photosensitive drum is disposed on the downstream side of the cleaning blade. A diffusing plate for diffusing the carrier liquid of the liquid developer is disposed obliquely above the elastic roller, and the carrier liquid is supplied onto the diffusing plate from the lower edge of the diffusing plate. The carrier liquid is caused to flow in a region formed with the photoconductor. In this way, the carrier liquid dilutes and removes the toner attached to the tip of the cleaning blade.
JP-A-6-23070

  The diffusion plate having the above configuration is not described in detail in Patent Document 1, but is constituted by a rigid plate material, and the carrier liquid supplied to the upper portion of the diffusion plate is transmitted by its own weight on the diffusion plate. While spreading, it reaches the lower edge of the diffusion plate, and the carrier liquid is supplied from the lower edge to the elastic roller.

  In such a configuration, the diffusion plate is disposed over the entire length of the elastic roller. When the carrier liquid is diffused on the diffusion plate, in order to facilitate the diffusion of the carrier liquid supplied on the diffusion plate, the elastic roller is actually moved from the position where the carrier liquid is supplied on the diffusion plate. It is good to make it long to the position (lower edge of a diffuser plate) to supply, or to make the inclination angle with a horizontal line small. However, if it does in this way, it will arrange | position in the state which laid the diffuser plate large, and since a large attachment space is needed in order to attach a diffuser plate, there exists a problem that a cleaning apparatus will enlarge.

  An object of the present invention is to efficiently supply a carrier liquid of a liquid developer to an elastic roller in order to form a storage portion in the longitudinal direction of the elastic roller that contacts the photosensitive drum. It is another object of the present invention to provide a cleaning device for a wet-type image forming apparatus capable of reducing the size of the cleaning device.

  In order to solve the above problems, the invention according to claim 1 is a wet type including an elastic roller that contacts the photosensitive drum and a cleaning blade that is provided downstream of the elastic roller and contacts the photosensitive drum. In the cleaning device of the image forming apparatus, there is provided a storage portion that stores the carrier liquid of the liquid developer and can adhere the carrier liquid to the elastic roller along the longitudinal direction of the elastic roller. The gist of the cleaning device of the wet image forming apparatus is as follows.

  A second aspect of the present invention provides the scraper according to the first aspect, further comprising a scraper that is in pressure contact with the elastic roller, wherein the storage portion is provided on the downstream side in the rotation direction of the pressure contact portion between the scraper and the elastic roller, and the rotation at the pressure contact portion is provided. The deposit on the elastic roller is cleaned on the upstream side in the direction.

  According to a third aspect of the present invention, there is provided a cleaning device for a wet image forming apparatus, comprising: an elastic roller that contacts the photosensitive drum; and a cleaning blade that is provided downstream of the elastic roller and contacts the photosensitive drum. A storage part for storing the carrier liquid, and a liquid-absorbing supply member that transports the carrier liquid in the storage part and adheres the carrier liquid to the elastic roller along the longitudinal direction of the elastic roller. The gist of the present invention is a cleaning apparatus for a wet image forming apparatus.

According to a fourth aspect of the present invention, in the first or third aspect of the present invention, the storage section includes means for supplying a carrier liquid.
According to a fifth aspect of the present invention, in the third aspect, the storage section also serves as a discharge path for the carrier liquid scraped off from the photosensitive drum.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the rotational peripheral speed of the elastic roller is the same or faster than the rotational peripheral speed of the photosensitive drum. Features.

A seventh aspect of the invention is characterized in that, in the third aspect, the supply member is a sheet.
The invention of claim 8 is characterized in that, in claim 3, the supply member is a coating roller supported rotatably.

  According to the first aspect of the present invention, since the storage portion is formed in the longitudinal direction of the elastic roller that contacts the photosensitive drum, the carrier liquid of the liquid developer is efficiently supplied to the elastic roller. The cleaning device can be reduced in size.

  According to the second aspect of the present invention, the storage portion can be formed by using the scraper for cleaning the deposits on the elastic roller and the space region sandwiched between the elastic rollers. There is an effect that a separate member is not required.

According to invention of Claim 3, there exists an effect similar to Claim 1.
According to invention of Claim 4, the carrier liquid of the said storage part can be replenished by the means to supply a carrier liquid.

According to the fifth aspect of the present invention, since the discharge path and the storage portion can be used together, a separate space for forming the storage portion is not required, and it is not necessary to enlarge the cleaning device.
According to the sixth aspect of the present invention, there is an effect that it is possible to prevent the residual developer pool from occurring on the upstream side of the nip between the elastic roller and the photosensitive drum.

  According to the invention of claim 7, since the sheet is not large in thickness, for example, when the storage portion also serves as the discharge path, in a narrow space between the screw provided in the discharge path and the elastic roller However, a supply member can be arrange | positioned, the freedom degree of an arrangement | positioning space is good and an attachment space is not limited.

  According to the eighth aspect of the invention, the effect of the third aspect can also be obtained by the application roller having liquid absorbency.

(First embodiment)
A first embodiment of a wet image forming apparatus cleaning apparatus according to the present invention will be described below with reference to FIGS. FIG. 1 shows a wet image forming apparatus (hereinafter referred to as an image forming apparatus 50). As shown in the figure, an image forming apparatus 50 includes a photosensitive drum 51, a main charging device 52, an LPH (LED PRINT HEAD) 53, a cleaning device 60, a charge eliminating lamp 57, a liquid developing device, and a transfer roller (not shown). Etc.

  The photosensitive drum 51 is an amorphous silicon drum and is charged by the main charging device 52 at a developing position so as to have a predetermined dark potential. The LPH 53 irradiates the surface of the charged photoconductive drum 51 with light corresponding to image information, whereby an electrostatic latent image is formed on the surface of the photoconductive drum 51. The photosensitive drum 51 corresponds to a latent image carrier.

  The developing roller 54 of the liquid developing device 54 applies a liquid developer composed of toner and carrier liquid C to the electrostatic latent image of the portion of the photosensitive drum 51 irradiated with light, whereby a toner image is applied to the photosensitive drum 51. Form.

  The toner image obtained by developing the electrostatic latent image formed as described above is transferred to a transfer belt or a transfer paper located in a nip with the transfer roller (not shown). The toner that has not been transferred onto the photosensitive drum 51 is scraped off by the cleaning device 60 in the next process. The photosensitive drum 51 is neutralized by a neutralizing lamp 57 in order to lower the residual potential on the surface and make it uniform, and thereafter, it is prepared for the next series of processes.

Here, the configuration of the cleaning device 60 that is a feature of the present embodiment will be described in detail.
The cleaning device 60 includes a cleaning blade 61, an elastic roller 62, a scraper 63, a screw 64, and the like.

  The cleaning blade 61 is made of a plate material having elasticity such as synthetic resin or urethane rubber, and is formed in a plate shape whose overall shape is a planar rectangle. The cleaning blade 61 is attached and fixed to the lower side surface of the housing 70 of the cleaning device 60 via a bracket 67, and is in counter contact with the photosensitive drum 51 (see FIGS. 1 and 2). The length L3 of the cleaning blade 61 is shorter than the length L4 of the photosensitive drum 51 (see FIG. 4).

  The elastic roller 62 is rotatably supported with respect to the housing 70 in the upper space in the housing 70. In order to prevent the elastic roller 62 from swelling due to the carrier liquid C, urethane rubber or nitrile rubber is preferable. Note that the surface of the elastic roller 62 may be coated to prevent the carrier liquid C from swelling. In this case, the elastic roller 62 is formed of epichlorohydrin rubber or silicon rubber, and the surface thereof is subjected to fluorine coating or urethane coating to prevent swelling.

  As shown in FIG. 4, a spur gear 72 is fixed to one end I of the shaft 62 a of the elastic roller 62, and meshes with a spur gear 74 fixed to one end of the shaft of the photosensitive drum 51. By setting the gear ratio of both the spur gears 72 and 74, the rotational peripheral speed of the elastic roller 62 is made equal to or faster than the rotational peripheral speed of the photosensitive drum 51. The spur gear 74 is driven in conjunction with a gear mechanism of a drive system. In the present embodiment, the rotation direction of the elastic roller 62 is the clockwise direction in FIGS. 1 and 2, and the photosensitive drum 51 is the counterclockwise direction.

  In this way, by making the rotational peripheral speed of the elastic roller 62 the same or faster than the rotational peripheral speed of the photosensitive drum 51, the residual developer is upstream of the nip between the elastic roller 62 and the photosensitive drum 51. It is made so that there is no accumulation.

  As shown in FIG. 1, the housing 70 includes a lower member 80, an upper member 90, and a pair of side plates 100 (see FIG. 3). The lower member 80 includes a bottom portion 81 having a recess 82 extending in the longitudinal direction, and a back plate portion 83 extending upward from the bottom portion 81. The upper member 90 has a connecting plate 91 superimposed on the back plate portion 83 and an upper plate 92 that covers the elastic roller 62 from above. A pair of side plates 100 (only one of them is shown in FIG. 1) is fixed to both ends of the lower member 80 and the upper member 90, and supports the elastic roller 62 rotatably.

  A bracket 95 is fixed to the upper plate 92, and the tip of the bracket 94 projects into the housing 70 through an opening provided near the connecting plate 91 of the upper plate 92. A scraper 63 is attached and fixed to the tip of the bracket 94. The tip of the scraper 63 extends obliquely toward the cleaning blade 61 side, and as shown in FIG. 2, the elastic roller 62 comes into contact with the lower portion on the back plate portion 83 side as shown in FIG. On the other hand, counter contact, that is, pressure contact is made so as to deform. By this counter contact, a storage space S as a storage portion is formed between the elastic roller 62 and the scraper 63, and the storage space S is provided over the longitudinal direction of the elastic roller 62. The storage space S is provided on the downstream side in the rotational direction at the pressure contact portion between the scraper 63 and the elastic roller 62.

  Further, the scraper 63 cleans the deposits on the elastic roller 62 on the upstream side in the rotational direction at the pressure contact portion. The length L1 of the scraper 63 is formed to be slightly longer than the length L2 of the elastic roller 62 (see FIG. 4). By making the length L1 of the scraper 63 longer than the length of the elastic roller 62, a sufficient storage space S between the elastic roller 62 and the scraper 63 can be obtained.

  Above the elastic roller 62, the upper plate 92 is formed with a plurality of supply holes 92 a at predetermined intervals. A carrier liquid supply pipe 97 is attached to each supply hole 92a. The carrier liquid supply pipe 97 is disposed so as to be slightly closer to the scraper 63 side than the top of the elastic roller 62. The carrier liquid supply pipe 97 is supplied with a carrier liquid C from a container (not shown) that stores the carrier liquid C (not shown) via a pump (not shown) and supplies the carrier liquid C to the upper part of the elastic roller 62. Since the carrier liquid C supplied to the upper part of the elastic roller 62 is arranged so that the carrier liquid supply pipe 97 is slightly closer to the scraper 63 side than the upper vertex of the elastic roller 62, the scraper 63 and the elastic roller It is made to accumulate in the storage space S formed between 62.

  There is nothing that closes both ends of the storage space S (spaces formed at both ends of the elastic roller 62 and the scraper 63). For this reason, in order for the carrier liquid C to accumulate in the storage space S, the supply amount of the carrier liquid C from the carrier liquid supply pipe 97 is transferred from the storage space S to the photosensitive drum 51 by the elastic roller 62. It is set to be larger than the total amount of the amount and the amount leaking from both ends of the storage space S.

  A screw 64 is disposed in the recess 82 of the housing 70. The screw 64 is rotatably arranged on the side plate 100 of the housing 70, and is operatively connected to a drive system (not shown) so as to be driven to rotate. As the screw 64 rotates, the carrier liquid C, toner component, and paper powder in the recess 82 are transferred to a waste liquid tank (not shown) through the discharge path.

Now, the operation of the cleaning device 60 configured as described above will be described.
The cleaning device 60 performs a cleaning operation when the image forming device 50 forms an image. In this case, the photosensitive drum 51 is rotated counterclockwise, and the elastic roller 62 is rotated clockwise.

  Then, the carrier liquid C is supplied from the carrier liquid supply pipe 97. The supply amount of the carrier liquid C from the carrier liquid supply pipe 97 is based on the total amount of the amount transferred from the storage space S to the photosensitive drum 51 by the elastic roller 62 and the amount leaking from both ends of the storage space S. Therefore, the carrier liquid C accumulates in the storage space S. The carrier liquid C collected in the storage space S is attached to the peripheral surface of the rotating elastic roller 62 and transferred to the photosensitive drum 51 side (see FIG. 2). As shown in FIG. 2, the carrier liquid C transferred to the photosensitive drum 51 side adheres to the photosensitive drum 51 and is supplied to the tip (edge portion) of the cleaning blade 61. The supplied carrier liquid C is scraped off by the tip of the cleaning blade 61, but the tip (edge portion) of the cleaning blade 61 is washed by the scraped carrier liquid C. In addition, the carrier liquid C that has cleaned the tip of the cleaning blade 61 is dropped into the recess 82 of the housing 70.

  On the other hand, the elastic roller 62 scrapes off toner components and impurities such as paper dust from the circumferential surface of the photosensitive drum 51. At this time, the toner component adhering to the elastic roller 62 and impurities such as paper dust are scraped off in the region R upstream of the contact portion of the scraper 63 with the elastic roller 62.

  Thus, according to the present embodiment, since the storage space S is formed in the longitudinal direction with respect to the elastic roller 62 in contact with the photosensitive drum, the carrier liquid C of the liquid developer is supplied to the elastic roller. 62 can be supplied efficiently. Further, unlike the prior art, it is not necessary to provide a diffusion plate, and therefore it is not necessary to lay the diffusion plate large, so that a large installation space is unnecessary, and the cleaning device can be miniaturized.

  In addition, the storage space S can be formed by using the scraper 63 that cleans deposits adhering to the elastic roller 62 and the space region sandwiched between the elastic rollers 62, in order to form the storage space S. There is an effect that a separate member is not required. Furthermore, since the carrier liquid supply pipe 97 and the like are provided as means for supplying the carrier liquid C to the storage space S, the carrier liquid in the storage section can be replenished.

  Further, since the rotational peripheral speed of the elastic roller 62 is the same or faster than the rotational peripheral speed of the photosensitive drum 51, a residual developer pool is generated in the elastic roller 62 and the photosensitive drum 51 on the upstream side of the nip. There is an effect that can be prevented.

(Second Embodiment)
Next, the cleaning device 60 of the second embodiment will be described with reference to FIG. In addition, about the same structure as 1st Embodiment or an equivalent structure, the same code | symbol is attached | subjected and description is abbreviate | omitted and a different structure is demonstrated.

In the second embodiment, the carrier liquid supply pipe 97 is omitted, and the scraper 63 that makes a counter contact with the lower part of the elastic roller 62 on the back plate portion 83 side is omitted.
In the housing 70, the portions where the members abut against each other so that the space surrounded by the cleaning blade 61, the bottom of the lower member 80 and the lower portion of the back plate 83, the side plate 100, and the cleaning blade 61 becomes the storage space S are liquid-tight. It is structured. In the storage space S, the liquid developer containing the carrier liquid C collected by the elastic roller 62 and the cleaning blade 61 can be stored, and a screw 64 is disposed. Thus, in 2nd Embodiment, the recessed part 82 in which the screw 64 is arrange | positioned is made into the discharge path, and this recessed part 82 is shared as the storage space S. FIG.

  Instead of the scraper 63 of the first embodiment, a coating sheet 110 as a sheet is attached to the tip of the bracket 95. The coating sheet 110 is formed in a substantially flat plate shape, and the lower part is disposed so as to be immersed in the carrier liquid C in the storage space S.

  The application sheet 110 is formed of a nonwoven fabric as a liquid-absorbing supply member made of polyester fiber, acrylic fiber, acrylic fiber, or vinylon fiber. It is preferable that the supply member has flexibility so as to correspond to the mounting space.

  A scraper 102 is supported on the shaft 62 a of the elastic roller 62 via a bracket 99. As shown in FIG. 5, the scraper 102 is pressed against the lower peripheral surface of the elastic roller 62 on the photosensitive drum 51 side in the counter direction.

  As in the first embodiment, the cleaning device 60 configured as described above performs a cleaning operation during image formation. In the application sheet 110, a capillary phenomenon occurs in the gap between the fibers constituting the nonwoven fabric, and the carrier liquid C is extracted from the recovered liquid developer E and raised, and the circumference of the elastic roller 62 is increased. Supplied to the surface. The carrier liquid C supplied and adhered to the peripheral surface of the elastic roller 62 wets the peripheral surface of the rotating elastic roller 62 and is transferred to the photosensitive drum 51 side. As shown in FIG. 5, the carrier liquid C transferred to the photosensitive drum 51 is attached to the photosensitive drum 51 and supplied to the tip (edge portion) of the cleaning blade 61. The supplied carrier liquid C is scraped off by the tip of the cleaning blade 61, but the tip (edge portion) of the cleaning blade 61 is washed by the scraped carrier liquid C. Further, the carrier liquid C that has cleaned the tip of the cleaning blade 61 is dropped into the storage space S.

  On the other hand, the elastic roller 62 scrapes off toner components and impurities such as paper dust from the circumferential surface of the photosensitive drum 51. At this time, the toner component adhering to the elastic roller 62 and impurities such as paper dust are scraped off in the region R upstream of the contact portion of the scraper 102 with the elastic roller 62.

  As described above, unlike the first embodiment, the second embodiment does not require the carrier liquid supply pipe 97 for supplying the carrier liquid C and the like, and can recycle only the carrier liquid C from the recovered liquid developer E. Can be configured as a system.

  In the second embodiment, the application sheet 110 capable of extracting only the carrier liquid C from the collected liquid developer is provided. In this case, since the thickness of the application sheet 110 is not large, the application sheet 110 can be disposed even in a narrow space between the screw 64 provided in the discharge path and the elastic roller 62. Since 110 has flexibility, even in a narrow space, the arrangement shape can be freely deformed according to the space. As a result, there is an effect that the degree of freedom of the arrangement space of the application sheet 110 is good and the installation space is not limited. In the second embodiment, since the storage space S can also be used as a discharge path, a separate space for forming the storage space S is not necessary, and the cleaning device does not need to be enlarged.

In addition, this invention is not limited to the said 1st Embodiment and 2nd Embodiment, You may change as follows.
In the configuration of the second embodiment, a coating roller 120 as a liquid-absorbing supply member may be provided in the housing 70 instead of the coating sheet 110. Specifically, as shown in FIG. 6, the application roller 120 is disposed between the elastic roller 62 and the storage space S. The application roller 120 is rotationally driven in conjunction with a drive system. The material of the application roller 120 is the same material as that of the application sheet 110 in the second embodiment. Then, as shown in FIG. 6, the application roller 120 extracts the carrier liquid C from the liquid developer E stored in the storage space S, and applies the extracted carrier liquid C to the elastic roller 62. Thereafter, the carrier liquid C applied to the elastic roller 62 is similarly attached to the photosensitive drum 51 and supplied to the tip of the cleaning blade 61 to clean the same part.

  Even in this configuration, unlike the first embodiment, the carrier liquid supply pipe 97 for supplying the carrier liquid C is not necessary, and the carrier liquid is recovered from the collected liquid developer E, as in the second embodiment. It can be configured as a recycling system that can extract only C.

1 is a schematic configuration diagram of a wet image forming apparatus according to a first embodiment embodying the present invention. Explanatory drawing of the outline | summary of a cleaning apparatus similarly. Similarly explanatory drawing of the supply hole 92a. FIG. 4 is an explanatory diagram of the relationship between the lengths of an elastic roller 62 and a scraper 63 and the relationship between the lengths of a cleaning blade 61 and a photosensitive drum 51. Explanatory drawing of the outline | summary of the cleaning apparatus of 2nd Example. Explanatory drawing of the outline | summary of the cleaning apparatus of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 51 ... Photosensitive drum 61 ... Cleaning blade 62 ... Elastic roller 63 ... Scraper 82 ... Recessed part (discharge path)
97 ... carrier liquid supply pipe (means for supplying carrier liquid C)
110 ... coating sheet (sheet, liquid-absorbing supply member)
120... Application roller (liquid absorbing supply member)
S: Storage space (storage part)
C ... Carrier liquid

Claims (8)

In a cleaning apparatus for a wet image forming apparatus, comprising: an elastic roller that contacts the photosensitive drum; and a cleaning blade that is provided on the downstream side of the elastic roller and contacts the photosensitive drum.
A cleaning device for a wet image forming apparatus, comprising: a reservoir for storing a carrier liquid of a liquid developer and capable of adhering the carrier liquid to the elastic roller along a longitudinal direction of the elastic roller. A scraper that presses against the elastic roller;
2. The storage portion is provided on the downstream side in the rotational direction at the pressure contact portion between the scraper and the elastic roller, and the deposit on the elastic roller is cleaned on the upstream side in the rotational direction at the pressure contact portion. A cleaning device for a wet-type image forming apparatus as described in 1. above. In a cleaning apparatus for a wet image forming apparatus, comprising: an elastic roller that contacts the photosensitive drum; and a cleaning blade that is provided on the downstream side of the elastic roller and contacts the photosensitive drum.
A reservoir for storing the carrier liquid of the liquid developer;
A wet-type image forming apparatus, comprising: a liquid-absorbing supply member that conveys the carrier liquid in the reservoir and can adhere the carrier liquid to the elastic roller along the longitudinal direction of the elastic roller. Cleaning device.   4. The cleaning apparatus for a wet image forming apparatus according to claim 1, further comprising means for supplying a carrier liquid to the storage section.   4. The cleaning device for a wet image forming apparatus according to claim 3, wherein the storage unit also serves as a discharge path for the carrier liquid scraped off from the photosensitive drum.   6. The wet image formation according to claim 1, wherein a rotational peripheral speed of the elastic roller is equal to or faster than a rotational peripheral speed of the photosensitive drum. Equipment cleaning device.   The cleaning apparatus for a wet image forming apparatus according to claim 3, wherein the supply member is a sheet.   4. The cleaning device of a wet image forming apparatus according to claim 3, wherein the supply member is a coating roller that is rotatably supported.

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