Patent Application
20050095031
The present invention relates to a seal member for effectively preventing leakage of developer, a developing apparatus including the seal member, a process cartridge including the developing apparatus, and an image forming apparatus.
Herein, an image forming apparatus refers to an apparatus in which an image is formed on a recording medium in an electrophotographic image forming scheme or an electrostatic recording scheme. Examples of the image forming apparatus may include an electrophotographic copying machine, an electrophotographic printer (such as laser beam printer or an LED printer), a facsimile apparatus, and a word processor.
A process cartridge means a cartridge in which at least a developing means (developing apparatus) as an image forming means (a processing means) and an electrophotographic photosensitive member (photosensitive drum) as an image bearing member are integrally disposed to make them removably mountable in a main assembly of an image forming apparatus as a cartridge.
In the electrophotographic image forming apparatus, an image bearing member electrically charged uniformly by a charging means is subjected to selective exposure to light, whereby an electrostatic latent image is formed on the surface of the image bearing member. The electrostatic latent image is developed into a visual image as a developer image (toner image) with developer (toner) supplied from a developing means (developing apparatus). Thereafter, the developer image is transferred onto a recording medium. Then, the developer image is fixed on the recording medium under application of heat or pressure, whereby image recording on the recording medium is performed. Further, developer remaining on the image bearing member after the transfer is removed by a cleaning means such as a cleaning blade, thus being recovered in a cleaning container as residual developer (removal toner). As a result, a subsequent developing operation can be performed in such a state that developer does not remain on the surface of the image bearing member.
Of these processing means for image formation, the image bearing member, the charging means, the developing means, the cleaning means, etc., are integrally disposed to provide a cartridge which is detachably mountable to the main assembly of the image forming apparatus. Such a cartridge has been put into practical use as a process cartridge. According to a scheme using the process cartridge, a user can effect replacement of cartridge by him/her self. In other words, the user can effect replacement of consumable parts, such as the image bearing member, developer and so on, without maintenance by service personnel.
In such a process cartridge, as a part thereof, a frame member constituting a developer container containing developer (toner) provided with an opening at an end thereof, is disposed. A developing roller as a developer carrying member, which is disposed rotatably to the opening, for conveying the toner to the image bearing member is also disposed. Further, a developing blade as a developer regulation member for regulating an amount of toner carried on the developing roller is disposed. Thus, the developing means, i.e., the developing apparatus is constituted. The opening of the frame member is opposed to the image bearing member. At both ends of the opening, an end portion seal member for preventing toner leakage in a longitudinal direction of the developing roller is disposed. Further, at one end of the opening, a flexible seat member for preventing leakage of toner from a spacing between the opening and the end portion seal member.
As the end portion seal member, a seal member formed at, e.g., an electrostatic flocking member or felt has been conventionally used. Particularly, in recent years, a seal member including a pile fabric has been used as the end portion seal member with a reduction in particle size of developer. The pile fabric includes a fabric base comprising warp and weft, and piles raised from the fabric base. The piles contact the developing roller as a seal portion to prevent leakage of toner.
In the conventional pile seal member, e.g., the fabric base is constituted by a layer of warp and weft, and a pitch of piles is determined by a pitch of weft constituting the fabric base.
More specifically,
In a weave (woven) structure of this pile seal member, the piles 27 are place in a woven state with respect to the single fabric base 200. In
As described above, formation of the pile seal member as the end portion seal member has been known (Japanese Utility Model Publication No. Hei 07-50760). Further, the use of a porous hollow fiber as a fiber for piles has also been known (Japanese Laid-Open Patent Application No. 2003-56709).
An object of the present invention is to provide a seal member, used in, e.g., an end portion seal means of a developing apparatus, which is further improved in sealing performance.
Another object of the present invention is to provide a seal member which maintains a stable sealing performance without lowering a degree of denseness of piles.
A further object of the present invention to provide a seal member which is less liable to cause damage of a developer carrying member, such as abrasion or wearing thereof.
A still further object of the present invention to provide a developing apparatus, a process cartridge, and an image forming apparatus which employ the above described seal member.
According to the present invention, there is provided a seal member, disposed at an opening of a developer container containing developer, for sealing the developer container at a boundary between the developer container and a developer carrying member, the sealing member including a warp pile fabric,
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
FIGS. 17(a), 17(b) and 17(c) are respectively an explanatory view showing a state of piles in a seal member extrusion step.
Hereinbelow, embodiments of a seal member, a developing apparatus, a process cartridge, and an image forming apparatus according to the present invention will be described with reference to the drawings.
The present invention relates to a seal member used as an end portion seal (means) for preventing scattering of toner from a side of a developing apparatus. The seal member is disposed in a developing apparatus, a process cartridge and an image forming apparatus.
An image forming apparatus according to an embodiment of the present invention will be described with reference to
First, referring to
The multi-color image forming apparatus 100 shown in
In this embodiment, the photosensitive drum 1, the charging apparatus 2, the developing apparatus 4, and the cleaning apparatus 6 are integrally disposed in a process cartridge 7 (7a, 7b, 7c, 7d).
The respective structural members of the image forming apparatus 100 will be described in detail.
The photosensitive drum 1 comprises an aluminum cylinder and a layer of organic photoconductor (OPC) coated on the peripheral surface of the aluminum cylinder, i.e., an OPC photosensitive member. The photosensitive drum 1 is rotatably supported by a supporting member at longitudinal end portions thereof. To one of the longitudinal end portions of the photosensitive drum 1, a driving force is transmitted from a driving motor (not shown), whereby the photosensitive drum 1 is rotationally driven in the counterclockwise direction of
The charging apparatus 2 may be of a type which employs a contact charging method. The charging apparatus 2 is an electrically conductive roller formed in a roller shape and is placed in contact with the surface of the photosensitive drum 1. The surface of the photosensitive drum 1 is uniformly charged by applying a charging bias voltage to the roller.
The scanner unit 3 is disposed in a direction substantially perpendicular to a line connecting centers of the photosensitive drums 1a, 1b, 1c and 1d, i.e., a horizontal direction substantially in parallel with an apparatus mounting surface in the figure. A polygon mirror 9 (9a, 9b, 9c, 9d) rotated at high speed by a scanner motor (not shown) is irradiated with image (information), corresponding to image (information) signals, emitted from a laser diode (not shown). The charged surface of the photosensitive drum 1 (1a, 1b, 1c, 1d) is selectively exposed to the image light reflected by the polygon mirror 9 through a focusing lens 10 (10a, 10b, 10c, 10d), whereby an electrostatic latent image is formed on the photosensitive drum 1.
The developing apparatuses 4a, 4b, 4c and 4d have developer containers 49 containing yellow, magenta, cyan, and black toners, respectively. The order of arrangement of these developing apparatuses may be appropriately changed.
An electrostatic transfer apparatus 5 is provided with an electrostatic transfer belt which is disposed opposite to all the photosensitive drum 1a, 1b, 1c and 1d and moved circularly in contact with the photosensitive drums. The transfer belt 11 comprises a film-like member and is vertically supported by four rollers 13, 14a, 14b and 15. The transfer belt 11 electrostatically adsorbs a recording medium S at its outer peripheral surface on the left-hand side thereof in the figure, and is moved circularly so that the recording medium S contacts the photosensitive drum 1 (1a, 1b, 1c, 1d). By doing so, the recording medium S is conveyed to a transfer position by the transfer belt 11. At the transfer position, the toner image on the photosensitive drum 1 (1a, 1b, 1c, 1d) is transferred onto the recording medium S.
Inside the transfer belt 11, a transfer roller 12 (12a, 12b, 12c, 12d) is disposed at a position at which it opposes the corresponding photosensitive drum 1 (1a, 1b, 1c, 1d) which contacts the transfer belt 11. As positive electric charge is applied to the recording medium S through the transfer belt 11, the toner image on the photosensitive drum 1, which is negative in polarity, is transferred by the electric field generated by the positive electric charge, onto the recording medium S in contact with the photosensitive drum 1.
The transfer belt 11 is wound about the four rollers including a driver roller 13, two follower rollers 14a and 14b, and a tension roller 15, and is rotationally driven in a direction of an indicated arrow in
A conveying portion 16 is a portion for conveying the recording medium S to the image forming portion, and includes a cassette 17 which holds a plurality of recording mediums S. During an image forming operation, a conveying roller 18 and a registration roller pair 19 are rotationally driven in synchronism with the image forming operation, whereby the plurality of recording mediums S in the cassette 17 are sequentially conveyed one by one. The leading edge of each recording medium S comes into contact with the registration roller pair 19 and is tempolarity stopped. Then, the recording medium S is conveyed to the transfer belt 11 by the registration roller pair 19 in synchronism with timing of image formation.
A fixing portion 20 is for fixing a plurality of unfixed toner images, different in color, transferred onto the recording medium S, to the recording medium S. The fixing portion 20 comprises a rotational heat roller 21a and a pressure roller 21b kept pressed upon the heat roller 21a to apply heat and pressure to the recording medium S. More specifically, while the recording medium S, onto which the plurality of toner images different n color have been transferred from the respective photosensitive drums 1, one for one, is conveyed through the fixing portion 20, by the fixing roller pair 21, heat and pressure are applied by the fixing roller pair 21. As a result, the plurality of different color toner images are fixed to the surface of the recording medium S.
In the image forming operation, the process cartridges 7 (7a, 7b, 7c, 7d) are sequentially driven in synchronism with the recording (image formation) timing. As they are driven, the photosensitive drums 1 (1a, 1b, 1c, 1d) are rotationally driven in the counterclockwise direction, and the scanner units 3 (3a, 3b, 3c, 3d) opposing the respective process cartridges 7 (7a, 7b, 7c, 7d) one for one are sequentially driven. By the rotational drive of the process cartridges 7, the charge roller 2 uniformly charges the peripheral surface of the corresponding photosensitive drum 1, and the uniformly charged peripheral surface of the photosensitive drum 1 is exposed to the light projected by the scanner unit 3 while being modulated with image (information) signals. As a result, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 1. The developing roller 40 in the developing apparatus 4 transfers the toner onto a lower potential portion of the electrostatic latent image to form a developer image (toner image) on the peripheral surface of the photosensitive drum 1, i.e., develop the electrostatic latent image on the photosensitive drum 1.
Then, the leading edge of the toner image on the peripheral surface of the most upstream photosensitive drum 1 is conveyed to an opposing line (position) where the most upstream photosensitive drum 1 and the transfer belt 11 is opposed to each other. The rotation of the registration roller pair 19 is started to release the recording medium S onto the transfer belt 11 so that the arrival of the leading edge of the recording medium S at the opposing line synchronizes with the arrival of the recording starting line of the recording medium S at the opposing line, whereby the recording medium S is conveyed to the transfer belt 11.
The recording medium S is sandwiched between the electrostatic adsorption roller 22 and the transfer belt 11 and is pressed onto the outer peripheral surface of the transfer belt 11, and a voltage is applied between the transfer belt 11 and the electrostatic adsorption roller 22. By doing so, an electric charge is induced in the recording medium S as a dielectric material and a dielectric layer of the transfer belt 11, whereby the recording medium S is electrostatically adsorbed by the transfer belt 11 at its outer peripheral surface. As a result, the recording medium S is stably adsorbed by the transfer belt 11 and conveyed to the most downstream transfer portion.
As described above, while the recording medium S is conveyed, the respective color toner images on the corresponding photosensitive drums 1 are sequentially transferred onto the recording medium S by the electric fields generated between the respective photosensitive drums and the corresponding transfer rollers 12.
After the transfer of the four color toner images onto the recording medium S, the recording medium S is separated from the transfer belt 11 with utilization of the curvature of the belt driving roller 13, and is conveyed into the fixing portion 20. In the fixing portion 20, the toner images are thermally fixed to the recording medium S. Thereafter, the recording medium S is discharged from the apparatus main assembly through an outlet portion 24 by a discharge roller pair 23.
Meanwhile, the photosensitive drum 1 after the transfer of the toner image onto the recording medium S is cleaned by the cleaning apparatus 6, whereby the residual developer is recovered from the peripheral surface of the photosensitive drum 1 before the charging step is performed again. The residual developer is recovered into a cleaning container 61.
As described above, the structure of the image forming apparatus usable in the present invention is not limited to that of the above described image forming apparatus. For example, it is possible to use a single photosensitive drum or a rotary developing apparatus in which developing apparatuses are mounted to a rotational member. It is also possible to employ an intermediary transfer member onto which a toner image is temporarily transferred from the photosensitive drum.
Further, the structure of the process cartridge is also not restricted to that of the process cartridge described above so long as it includes the photosensitive drum 1 and the developing apparatus 4. The process cartridge may be omitted from in the image forming apparatus.
Further, the developing apparatus may be modified into a developing unit so that only the developing apparatus is detachable from the process cartridge.
Next, the weave structure of the warp pile fabric, used as the end portion seal (member) 100, according to an embodiment of the present invention will be described with reference to
As shown in
The number of denier per one pile, the pile density, and the fiber density can be adjusted in the following manner.
First, in the present invention short fibers are spun into a single yarn, and a plurality of yarns are twisted to provide a single pile (one pile). By controlling an amount of the short fibers at the time of spinning the short fibers, it is possible to adjust the number of denier (per one pile) of a first prepared single pile. Further, it is possible to finally adjust the number of denier per one pile of the resultant piles depending on the number of yarns to be twisted. When the thus prepared piles are set to a weaving machine, a density of the piles to be set to the weaving machine is controlled to adjust a resultant pile density. The fiber density referred to herein is a value representing an amount of the short fibers per unit area. Accordingly, the fiber density is determined by conditions of the spinning and twisting with respect to the piles and a degree of pile density at the time of weaving the piles.
A process of producing a seal member using the warp pile fabric in this embodiment will be described in the order of production steps.
Referring to
A basic texture of the two-layer weave structure will be described more specifically with reference to
The fabric base 200 is constituted by the two layers comprising four warps 25a to 25d (or 25e to 25h) and two wefts 26a and 26b (or 26c and 26d). The piles 27 are respectively woven into the two layers. In
As shown in
In this embodiment, the piles 27 are woven in a V shape. In other words, the warp pile fabric is prepared through a V pile weave in which a fabric texture of the piles has a V shape.
An actual weave structure of the seal member 100 using the warp pile fabric 200 have the two layer weave structure will be described with reference to
The warps 25 and the wefts 26 of the seal member 100 constitute the two layers. As shown in
An example of dimensions with respect to the warps 25, the wefts 26, and the piles will be described below.
The warp 25 is two folded (ply) yarn which comprises polyester and rayon and has a fineness of 177 denier (D) (No. 30 count cotton yarn), and the weft 26 is a single yarn which comprises polyester and has a fineness of 333 D (No. 15 count cotton yarn).
One pile comprises two species of acrylic fibers having finenesses of 3 D and 1.5 D and a rayon having a fineness of 1.5 D. These fibers are pun into two folded yarn (529 D) including a single yarn (265 D). The two folded yarn and electroconductive fibers having a fineness of 20 D/fiber are twisted to provide a single pile (one pile) 27.
The acrylic fibers constituting the pile 27 are not an ordinary acrylic fiber but a porous hollow fiber, which will be described with reference to
In this embodiment, rayon which is not porous is used in spinning for preparing the piles 27. This is because the firmness of the piles 27 is excessively lowered when only the hollow fibers are used, so that the firmness is controlled by adding the non-porous rayon fiber during the spinning.
The warp pile fabric woven in the two-layer structure is, after being woven, processed until it is finished a the seal member. Such processing steps are shown in a flow chart of
Referring to
Herein, the pile length, as show in
After the shearing step (step S1), in a step S2, the warp pile fabric 200 is subjected to a brushing step for unvaveling the piles 27. The brushing step will be described more specifically with reference to
This is further described in detail with reference to
In this state in the brushing step, the roller 33a is rotated in the opposite direction of the arrow B as described above, so that a direction of the unraveled piles is not stabilized. Accordingly, as shown in
In this embodiment, as shown in
In the case where the piles 27 are not obliquely raised from the fabric base 200, referring to
In the state that the brushing is effected, the piles are placed in the unraveled state, so that the pile length is still somewhat ununiform. For this reason, the warp pile fabric is again subjected to the shearing in a step S3, thus being further stabilized in its pile length.
Next, the warp pile fabric 200 is subjected to a polisher processing (polishing) in a step 4 in order to further stabilize the obliquely raised state of the piles 27 in the brushing step (step S2).
In the polisher (polishing) step S4, as shown in
Thereafter, in a step S5, the oblique raised state and the length of the piles 27 are still further stabilized through the shearing and the brushing. Then, in a step S6, a coating treatment is effected on the back surface of the warp pile fabric. This coating step will be described with reference to
Thereafter, in a step S7, the warp pile fabric 200 is further subjected to the brushing and the shearing to be further stabilized in obliquely raised state and pile length. As a result, the warp pile fabric 200 is placed in a finished state as the warp pile fabric. The piles 27 finally have a pile length of not less than 3.2 mm and provides the warp pile fabric 200 generally called “moquette”.
Then, in a step S8, a double-faced adhesive tape is applied onto the back surface of the warp pile fabric 200. More specifically, this tape is used for adhering the seal member 100 to the developer container 49 etc., at the time of using the warp pile fabric 200 as the seal member 100. However, in the coating state, the fabric base 200 is hardened by the adhesive 36. In other words, the back surface of the fabric base 200 becomes a firm uneven surface. As a result, when the double-faced adhesive tape is applied onto the fabric base 200, an adhesive surface area of the adhesive tape onto the fabric base 200 is liable to be decreased to lower an adhesive force. For this reason, frictioning is performed at the back surface of the fabric base 200.
As shown in
By performing all the above-described steps S1 to S8, the warp pile fabric 200 which has a smoothness and a reinforced adhesiveness to the developing apparatus 4, is completed. The thus-improved warp pile fabric 200 is finished in a state that it has a weight per unit area of not less than 810 g/cm2.
In the present invention, the order of the above described steps is not limited to that in the case of the above-described warp pile fabric 200 but may be appropriately changed depending on weaving conditions, such as a density, the number of denier, and a pile length.
The above-finished warp pile fabric 200 is extruded in a desired dimension in a step S9 and used as the seal member 100.
The extrusion of the seal member 100 from the warp pile fabric 200 is performed as follows.
The seal member 100 is extruded in a state that the direction of pile yarns 27 is inclined in a range of 40-50 degrees toward the rotation direction of the developing roller 40. By doing so, when the developing roller 40 is mounted on the seal member 100 and rotated, the direction of the piles (pile yarns) 27 is prevented from being unintendedly changed with the rotation of the developing roller 40.
As shown in
In another example, as shown in
Accordingly, in this embodiment, as shown in
As described above, the warp pile fabric 200 is subjected to the processing steps including S1: shearing, S2: brushing, S3: shearing, S4: polisher, S5: shearing and brushing, S6: coating, S7: brushing and shearing, S8: frictioning and seal adhesion, and S9: extrusion.
The thus finished seal member 100 (through the steps S1 to S9) is set to have a repulsive force of not more than 500 g. More specifically, a seal member 100 extruded to have a surface area of 178 mm2 is set to have a repulsive force of not more than 500 g when it is pressed by a circular metal measuring head having a diameter of 60 mm until it has a thickness of 2.5 mm.
The thus prepared seal member 100 is used as an end portion seal 100 for the developing apparatus 4. This seal member 100 is flexibly deformed even at a portion having a difference in level, such as a mounting portion at an end portion of the developing blade 41. As a result, the seal member blocks a spacing with reliability to seal the toner.
Such a portion will be described with reference to
When the developing roller 40 is mounted, the developing blade 41 contacts the developing roller 40 at a developing roller abutting portion 41c under pressure. As a result, only the developing blade 41 abutting portion 41a of the (end portion) seal member 100 is pressed, whereby a spacing is created at a boundary portion 41b. However, the end portion seal 100 comprising the seal member 100 using the above described improved warp pile fabric 200 is flexibly deformed even at the timing of such pressing. For this reason, the spacing is not created at the boundary portion 41b. Accordingly, the toner is prevented from being leaked from the boundary portion 41b. Further, at that time, the seal 100 exhibits its sealing performance with respect to also the toner entering it from the back side of the developing blade 41.
As described above, the seal member using the warp pile fabric which has been subjected to the above described processing retains its good sealing performance with respect to toner having a smaller particle size.
The seal member 100 comprising the warp pile fabric of this embodiment as its material is mounted, as the end portion seal, in the image forming apparatus 110 shown in
In this embodiment, with respect to the warp pile fabric 200 which has been formed through the V pile weave providing a V shaped fabric texture of piles 27 and subjected to the processing as shown in the flow chart of
A continuous image formation test (durability test) was performed as Experiment 1 by using the various seal members 100 using warp pile fabrics 200 having various combinations of the number of deniers (per one pile 27), the fiber densities, and the pile densities. Evaluation was performed with respect to a sealing performance and a state of damage to the developing roller 40 by the seal member 100.
Experiment 1
Eight warp pile fabrics No. 1 to No. 8 shown below were prepared as samples for end portion seals 100.
(Warp Pile Fabric)
No. 1: a conventional warp pile fabric having a number of denier (per one pile 27) of 530 denier (D), a fiber density of 332,000 fibers/inch2, and a pile density of 1,050 piles/inch2.
No. 2: a warp pile fabric having a number of denier of 330 D, a fiber density of 690,000 fibers/inch2, and a pile density of 2,100 piles/inch2.
No. 3: a warp pile fabric having a number of denier of 350 D, a fiber density of 251,000 fibers/inch2, and a pile density of 1,260 piles/inch2.
No. 4: a warp pile fabric having a number of denier of 180 D, a fiber density of 672,000 fibers/inch2, and a pile density of 2,100 piles/inch2.
No. 5: a warp pile fabric having a number of denier of 400 D, a fiber density of 265,440 fibers/inch2, and a pile density of 1.050 piles/inch2.
No. 6: a warp pile fabric having a number of denier of 330 D, a fiber density of 672,000 fibers/inch2, and a pile density of 1,680 piles/inch2.
No. 7: a warp pile fabric having a number of denier of 330 D, a fiber density of 265,440 fibers/inch2, and a pile density of 840 piles/inch2.
No. 8: a warp pile fabric having a number of denier of 200 D, a fiber density of 265,440 fibers/inch2, and a pile density of 1,050 piles/inch2.
The durability test was performed in the following manner.
Each of the seal member 100 prepared by using the above described warp pile fabrics No. 1 to No. 8 was mounted, as the end portion seal 100 for the developing apparatus 4, in the image forming apparatus shown in
The results are shown in Table 1.
*1, *2: The sealing performance and the state of damage to the developing roller 40 were evaluated as follows.
A: Satisfactory performance (in terms of sealing performance or damage prevention).
B: There is a possibility that the performance is not satisfactory when various irregularities are taken into consideration.
C: Very unsatisfactory performance.
The conventional warp pile fabric No. 1 has the number of denier of 530 D and the fiber density of 332,000 fibers/inch2. However, the sealing performance and the damage to the developing roller 40 were both evaluated as “B”.
The firmness of the piles 27 is decreased by reducing the number of denier of the piles 27. The warp pile fabric No. 2 having the smaller number of denier but having the fiber density of 690,000 fibers/inch2 increased to compensate for a lowering in sealing performance by the narrowed piles 27 satisfies the sealing performance. However, the fiber density is excessively increased, so that the effect of the decrease in firmness by the narrowed piles 27 cannot be attained. Further, the damage to the developing roller 40 is being caused to occur. For this reason, the damage to the developing roller 40 is evaluated as “B”.
In order to suppress the damage to the developing roller 40 with respect to the warp pile fabric No. 2, its fiber density is decreased to 251,000 fibers/inch2, and the number of denier is increased to 350 D in order to compensate for the sealing performance. The thus prepared warp pile fabric No. 3 is, however, excessively lowered in the number of denier, so that the sealing performance cannot be satisfied.
With respect to the warp pile fabric No. 4 which has the number of denier (fineness of piles 27) decreased to 180 D for sufficiently decrease the firmness and has the fiber density of 672,000 fibers/inch2, the damage to the developing roller 40 is evaluated as “A”. However, the number of denier is excessively lowered, so that the sealing performance cannot be satisfied.
In order to improve the sealing performance, the fineness of piles 27 is increased to 400 D, and the fiber density is decreased to 265,440 fibers/inch2 in order to avoid the damage to the developing roller 40. The thus prepared warp pile fabric No. 5 satisfies the sealing performance. However, the damage to the developing roller 40 is being caused to occur. For this reason, the damage to the developing roller 40 is evaluated as “B”.
The warp pile fabric No. 6 (according to the present invention) having the fineness of piles 27 of 330 D and the fiber density of 672,000 fibers/inch2 satisfies both the sealing performance and the damage prevention performance to the developing roller 40.
The warp pile fabric No. 7 (according to the present invention) having the fineness of piles 27 of 330 D and the fiber density of 265,440 fibers/inch2 satisfies both the sealing performance and the damage prevention performance to the developing roller 40.
The warp pile fabric No. 8 (according to the present invention) having the fineness of piles 27 of 200 D and the fiber density of 265,440 fibers/inch2 satisfies both the sealing performance and the damage prevention performance to the developing roller 40.
As apparent from Table 1, in the seal member sharing the fiber density (representing the number of fibers per unit area) of not less than 260,000/inch2 and not more than 680,000/inch2, by providing the warp pile fabric with the number of denier (per one pile yarn) of not less than 200 D and not more than 350 D, the resultant seal members are improved in sealing performance compared with the conventional seal member. Further, the seal members are also causes less damage to the developing roller 40 than the conventional seal member. The lower limit of the number of denier is determined on the basis of a lower limit condition permitting actual weaving of piles by a weaving machine.
Other than Experiment 1 described above, warp pile fabrics having combinations of the fiber density in the range of not less than 260,000/inch2 and not more than 680,000/inch2 and the number of denier (per one pile yarn) of not less than 200 D and not more than 350 D were similarly prepared and evaluated. As a result, the resultant seal members sufficiently satisfy not only the sealing performance but also the damage prevention performance to the developing roller, even in the case of using the high speed image forming apparatus.
As described hereinabove, according to the present invention, there are provided a seal member, a developing apparatus, a process cartridge, and an image forming apparatus, wherein the seal member is formed of a warp pile fabric through a V pile weave providing a V-shaped pile fabric texture and has a fiber density, representing a number of fibers per unit area, of not less than 260,000/inch2 and not more than 680,000/inch2 and a number of denier per one pile of not less than 200 denier and not more than n350 denier. As a result, it is possible to suppress damage to the developer carrying member and provide a good sealing performance.
This application claims priority from Japanese Patent Application No. 373697/2003 filed Oct. 31, 2003, which is hereby incorporated by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 373697/2003(PAT.) | Oct 2003 | JP | national |
