JP3830118B2 - Toner sealing structure, developing device, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner seal structure such as a developing device and a cleaning device, and more particularly to a toner seal structure and a developing device excellent in preventing leakage of a small particle size toner, and an image forming apparatus including the developing device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus using dry toner, a seal is disposed between a blade that contacts the surface of a rotating body of a developing device or a cleaning device and its mounting base, and the toner leaks into the image forming apparatus main body. Is to prevent. As a seal that seals between the blade and the mounting base, a seal formed of a single cell sponge or a continuous cell sponge is used. Here, the single-cell sponge refers to a sponge configured such that each cell is a single chamber and does not allow air flow, and the continuous-cell sponge has a network structure and air flow. This is a sponge that is composed of many.
[0003]
[Problems to be solved by the invention]
However, the single-cell sponge seal is able to satisfactorily seal small-diameter toner, but because it has a structure in which gas is contained inside, the pressure between the blade and the rotating body is changed by the pressure change of the internal gas. There is a problem that the contact pressure becomes unstable. Therefore, in the developing device using such a seal, there arises a problem that the thickness of the toner layer on the surface of the developing roller becomes non-uniform. In addition, the cleaning device using such a seal causes a problem that variation occurs in the operation of removing the residual toner on the surface of the photoreceptor.
[0004]
On the other hand, since the seal of the continuous sponge has a network structure, spherical polymer toner or toner having a small particle diameter may pass between the mesh partition walls and leak to the outside. Therefore, the seal of the continuous sponge has a problem that it is not suitable for sealing a polymer toner or a small particle size toner. Here, the gas repellent sponge seal does not contain gas inside, so that the contact pressure between the blade and the rotating body does not become unstable unlike the single cell sponge.
[0005]
A technique for sealing between the blade and the mounting base with a silicon sealing material or an adhesive is also known. However, this prior art has the disadvantages that it takes time to dry the silicon sealing material and the adhesive, and that it is difficult to separate the blade from the mounting base and to reassemble the blade and the mounting base. .
[0006]
Therefore, the present invention can reliably seal the polymerized toner and the small particle size toner without causing instability of the contact between the blade and the rotating body, and further, the blade and the mounting base side can be decomposed. An object of the present invention is to provide a toner seal structure that can be easily reassembled, and an image forming apparatus including a developing device and a cleaning device having such a seal structure.
[0007]
[Means for Solving the Problems]
The invention of claim 1 relates to a cleaning device used in a dry toner developing type image forming apparatus. The cleaning device includes (1) a cleaning blade that is pressed against the surface of the rotating photoconductor to scrape off toner remaining on the surface of the photoconductor, and (2) a toner storage chamber that stores toner scraped off by the cleaning blade. And (3) a plate that is made of an elastically deformable resin material and is pressed against the surface of the photoconductor to prevent the toner stored in the toner storage chamber from being scattered or leaked to the outside. A blade, (4) a cleaning blade mounting base to which the cleaning blade is fixed, and (5) a mounting base to which the lower blade is fixed via a seal. Further, in this cleaning device, the seal is formed of a semi-bullet sponge, is disposed between the mounting base and the lower blade, and is fixed to the lower blade by a mounting plate fixed to the mounting base with a screw. It is sandwiched between the mounting bases in a compressed state, and only the portions located at both ends of the photoconductor extend from the lower blade to the back side of the cleaning blade. Here, the semi-bullet sponge is not a single cell sponge that is closed as a single chamber, but the walls of several adjacent cells are partially opened, as if they were connected in a maze shape. In addition, it is a sponge that is not open like most sibling sponges.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
(Developer)
FIG. 1 is a schematic configuration diagram of a developing device 1 having a toner seal structure according to an embodiment of the present invention.
[0015]
As shown in FIG. 1, the developing device 1 is attached to the opening 2 a of the developing housing 2 so that the developing roller 3 (rotating body) and the supply roller 4 can rotate. Among these, the developing roller 3 conveys the toner to the developing area 6 of the photoconductor 5 and visualizes the electrostatic latent image on the photoconductor 5. The supply roller 4 is in rolling contact with the developing roller 3 to supply toner to the developing roller 3 side.
[0016]
Here, the tip of the blade 7 is in sliding contact with the developing roller 3. The blade 7 is formed of a stainless steel plate so that it can be elastically deformed, and is fixed to the lower mounting base 2 b of the opening 2 a of the developing housing 2 with a fastener 9 via a seal 8. The blade 7 is fixed to the lower mounting base 2b in a cantilever shape, and the tip of the blade 7 comes into contact with the outer surface of the developing roller 3 with a predetermined contact pressure, and the toner layer on the outer surface of the developing roller 3 The thickness of is controlled to be a desired thickness. The fastener 9 includes a plate-shaped fastening plate 9a having a flange a1 that engages with the tip of the lower mounting base 2b of the developing housing 2, and a screw 9b that is screwed to the fastening plate. The blade 7 is configured such that a portion 7a that contacts the developing roller 3 is formed of a hard member such as glass or an elastic member such as silicone rubber, and this portion 7a is provided on an elastically deformable member such as a stainless steel plate. May be.
[0017]
The seal 8 is formed in a plate shape with a semi-continuous sponge, and is attached between the blade 7 and the lower attachment base portion 2b in a compressed state of 50% or more. This semi-continuous sponge has a labyrinth-like sponge structure and can effectively seal polymerized toner and small particle size toner. In addition, this semi-bullet sponge is different from the structure of a single-cell sponge (ie, it is not a structure that contains gas inside), and is held in an initial compressed state regardless of changes in the external environment. The contact pressure between the blade 7 and the developing roller 3 does not change. Therefore, in the developing device 1 using such a seal 8, the thickness of the toner layer on the outer surface of the developing roller 3 is always regulated uniformly by the blade 7, and good development can be performed by the developing roller 3. . In addition, as described above, when the seal 8 is used in a compressed state of 50% or more, the contact state between the blade 7 and the developing roller 3 is further stabilized, and the toner sealability is further improved.
[0018]
A plastic elastic seal plate 10 is fixed to the upper mounting base 2c of the opening 2a of the developing housing 2 in a state where it can be bent and deformed. The elastic seal plate 10 has a leading end extending toward the downstream side in the rotation direction of the developing roller 3, and the leading end uniformly contacts the developing roller 3, so that the toner inside the developing housing 2 is scattered outside. Is preventing.
[0019]
In the toner storage unit 11 on the left side of the supply roller 4 in FIG. 1, the toner stirring paddle 12 that stirs the toner to uniformly charge the toner and splashes the toner toward the supply roller 4 is stored so as to be rotatable. ing.
[0020]
According to the present embodiment configured as described above, the seal 8 disposed between the blade 7 and the lower mounting base 2b is formed of a semi-continuous sponge. Even when toner (average particle size of 9 μm or less) is used, leakage of the toner can be effectively prevented.
[0021]
In addition, as described above, according to the present embodiment, the seal 8 made of the semi-continuous sponge does not change in form regardless of changes in the external environment, and exhibits a desired sealing function. Therefore, the blade 7 can always be brought into sliding contact with the developing roller 3 with a desired contact pressure. Therefore, in this embodiment, the thickness of the toner layer on the outer peripheral surface of the developing roller 3 can be uniformly regulated by the blade 7, and good and stable image formation is possible.
[0022]
The lower mounting base 2b, the seal 8 and the blade 7 can be disassembled and reassembled with respect to the developing housing 2, and are particularly characterized in that the seal 8 can be reused. That is, the seal 8 formed of a semi-bullet sponge can be restored to its original state by blowing cleaning air when the developing device 1 is disassembled. Further, the seal 8 can be restored to its original state by being housed in the decompression chamber. Therefore, when the developing device 1 is recycled, the seal 8 is not peeled off from the lower mounting base 2b and discarded, and it is not necessary to replace the seal 8 with a new one.
[0023]
In addition, the present embodiment can simplify the assembling work of the developing device 1 by the amount that does not require time for drying or the like, as compared with the conventional example using a silicon sealing material or an adhesive.
[0024]
In addition, in this embodiment, since the gap between the developing roller and the developing housing is closed by the elastic seal plate, the effect of the seal 8 is combined with the toner from the inside of the developing housing 2 to the outside. Scattering and leakage can be effectively prevented.
[0025]
(Image forming device)
FIG. 2 is a schematic configuration diagram of the image forming apparatus 20 including the developing device 1 as described above.
[0026]
Around the photosensitive member 5, a paper dust removing brush 21, a charging device 29, a developing device 1, and a transfer roller 22 are arranged. An optical unit 23 is disposed below the photoreceptor 5, and an exposure optical path 24 is formed between the charging device 29 and the developing device 1.
[0027]
A sheet material (paper or plastic sheet or the like) 26 as a transfer member stacked on the paper feed tray 25 is fed out by a paper feed roller 27 and is connected to the photoconductor 5 via a registration roller pair 28 and a sheet material supply path 30. The toner image is conveyed between the transfer roller 22 and the toner image on the photosensitive member 5 is transferred by the transfer roller 22. The sheet material 26 to which the toner image has been transferred is discharged onto the paper discharge tray 33 by the paper discharge roller pair 32 after the toner image is fixed by the fixing device 31.
[0028]
As described above, the image forming apparatus 20 configured as described above includes the developing device 1 that can prevent scattering and leakage of the polymerized toner and the small particle size toner, and the toner enters the image forming apparatus main body 34. Leakage can be effectively prevented and the sheet material 26 is not soiled by the scattered and leaked toner, so that a high-quality image can be formed.
[0029]
(Cleaning device)
FIG. 3 is a schematic configuration diagram of a cleaning device 40 having a toner sealing structure according to the embodiment of the present invention.
[0030]
As shown in FIG. 3, the cleaning device 40 fixes a rubber cleaning blade 41 to the cleaning blade mounting base 42 and presses the tip of the cleaning blade 41 against the surface of the photoconductor 5. The residual toner on the surface is scraped off. The residual toner scraped off is stored in the toner storage chamber 43 of the cleaning device 40, and is then conveyed to a toner recovery tank (not shown).
[0031]
The cleaning device 40 is configured to hold a concave seal 44 formed of a semi-bullet sponge between the lower blade 45 and the mounting base 46 of the lower blade 45 in a compressed state of 50% or more. . FIG. 4 shows the relationship between the concave seal 44, the lower blade 45, and the cleaning blade 41 as viewed from the inside of the cleaning device. As shown in FIG. 4, the concave seal 44 extends from the lower blade 45 to the back side of the cleaning blade 41 only at the portions located at both ends of the photoconductor 5. Accordingly, the toner scraped off from the surface of the photoconductor 5 can be reliably accommodated in the cleaning device 40 without being scattered around the photoconductor 5. The lower blade 45 is formed in a plate shape with an elastically deformable resin material and is pressed against the surface of the photosensitive member 5 (rotating member) with a predetermined pressure and scraped off from the surface of the photosensitive member 5. Is prevented from splashing and leaking outside the cleaning device 40. Here, the lower blade 45 and the seal 44 are sandwiched between the mounting base 46 and the mounting plate 48 by a mounting plate 48 fixed to the mounting base 46 with screws 47.
[0032]
In this way, if the seal 44 formed of the semi-bullet sponge is used in the cleaning device 40, the polymerization toner and the small particle size toner do not leak to the outside from between the lower blade 45 and the mounting base 46, The same effect as in the case of the developing device 1 can be obtained.
[0033]
The cleaning device 40 is provided with a cleaning blade 41 at the top in FIG. 3 , and the half-bulb sponge seal may be disposed between the cleaning blade 41 and the cleaning blade mounting base 42. .
[0034]
【The invention's effect】
As described above, in the cleaning device of the present invention, since the seal disposed between the blade and the mounting base is formed of a semi-bullet sponge, it is effective even when polymerized toner or small particle size toner is used. Toner leakage can be prevented.
[0035]
Further, according to the cleaning device of the present invention, the seal made of the semi-bullet sponge is not changed in form regardless of the change of the external environment , as compared with the seal made of the single cell sponge , and the desired sealing function Therefore, the blade can be slid in contact with the rotating body at a desired contact pressure at all times, and the contact state between the blade and the rotating body is stabilized.
[0036]
Furthermore, according to the cleaning device of the present invention, since the seal is formed of a semi-bullet sponge, it can be restored by blowing air or placing it in a decompressed atmosphere, so that the seal can be reused. become.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a developing device having a toner seal structure according to an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.
FIG. 3 is a schematic configuration diagram of a cleaning device having a toner seal structure according to an embodiment of the present invention.
FIG. 4 is a partial perspective view of the cleaning device.
DESCRIPTION OF SYMBOLS 1 ... Developing apparatus, 2 ... Developing housing, 2a ... Opening part, 2b ... Lower mounting base (mounting base), 2c ... Upper mounting base (mounting base), 3 ... Developing roller (rotating body) 5... Photosensitive body (rotating body) 7... Blade, 8, 44... Seal, 20... Image forming apparatus, 21. ... Charging device, 41 ... Cleaning blade (blade), 42 ... Cleaning blade mounting base (mounting base), 45 ... Lower blade (blade), 46 ... Mounting base

Claims (1)

A cleaning blade that is pressed against the surface of the rotating photoreceptor and scrapes off the toner remaining on the surface of the photoreceptor;
  A toner storage chamber for storing toner scraped off by the cleaning blade;
  A lower blade that is formed in a plate shape with an elastically deformable resin material and prevents the toner stored in the toner storage chamber from being scattered and leaked to the outside by being pressed against the surface of the photoreceptor;
  A cleaning blade mounting base to which the cleaning blade is fixed;
  An attachment base to which the lower blade is fixed via a seal,
  A cleaning device used in an image forming apparatus of a dry toner development system,
  The seal is formed of a semi-bullet sponge, is disposed between the mounting base and the lower blade, and is compressed between the lower blade and the mounting base by a mounting plate fixed to the mounting base with a screw. In this state, only the portions located at both ends of the photoconductor are extended from the lower blade to the back side of the cleaning blade.
  A cleaning device.

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