JP2003300638A - Sheet processing member, and sheet transporting device and image forming device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remarkably improve the durability of a roller and the like for transporting a sheet. <P>SOLUTION: A rotatable roller member for transporting a sheet material has a plurality of elastically deformable first projections 8b, 8c, 8d projecting to the rotating radial direction of a roller surface, and adjacent to each other, and further has elastically deformable second projections 8f, 8g projecting to the rotating radial direction of the roller on connected tips of at least two or more first projections. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to contacting a sheet,
The present invention relates to a sheet acting member for conveying a sheet by the frictional force, a sheet conveying device using the same, and an image processing device such as an electrophotographic copying machine, a printer, a word processor, and a facsimile device.

[0002]

2. Description of the Related Art Conventionally, there are many types of image processing in an image forming apparatus, an image reading apparatus, and the like, and a sheet conveying apparatus used therefor also adopts various feeding system and separation system specifications. . Among them, the so-called retard separation method is known to be the most reliable means for separating sheets.

In the retard separation system, as shown in FIG. 8, a sheet is nipped and conveyed by a feeding roller 100 that rotates in the conveying direction and a separation roller 101 that has a torque limiter 102 and is applied with an opposite force. It is a thing. This separation roller 10
1 is the feeding roller 100 when there is no sheet or only one sheet
When the number of sheets is two or more, the sheet is rotated backward (in the direction of arrow B) and is pushed back to the feeding means by being driven by the rotation of the sheet (in the direction of arrow A). It is to separate.

Most of the materials of the surfaces of the feeding roller 100 and the separating roller 101 are made of synthetic rubber such as EPDM (ethylene / propylene rubber) and silicon, and the separating and conveying are performed by the frictional force.

[0005]

As described above, in the retard separation system, the separation performance largely depends on the friction of the roller, and the surface deteriorates due to abrasion or the like when the number of passing sheets is large, such as hundreds of thousands of sheets. The frictional force of the roller is reduced due to the adhesion of powder or the like, which causes a jam.

Here, the feeding roller 100 and the separating roller 101
The factors that determine the durability of the will be specifically described. The feed roller 100 is conventionally made of synthetic rubber such as EPDM or silicon, and the separating roller 101 is generally made of similar synthetic rubber or a sponge material such as urethane or silicon. As shown in FIG. 9, these rollers have a polishing grain 100 provided on the surface in a polishing process.
a and 101a are provided, and the polishing stitches 100a and 101a are important factors that determine the durability of the roller during actual feeding and conveying.

More specifically, paper dust is generated from the conveyed sheet during the actual feeding operation.
Since the paper powder escapes into the grooves (valleys) 100b and 101b of 01a, the roller surface and the sheet surface can surely come into contact with each other, and a desired frictional transfer force can be obtained (Fig. 9 (a)). ).

However, due to the durability, the polishing stitches 100a, 1
When 01a is worn and disappears, as shown in FIG. 9 (b), there is no escape area for the paper dust, and a layer of paper dust is formed between the roller and the sheet. The frictional conveyance force decreases and slip jams frequently occur. Normally, such a state is defined as the durability life of the roller.

That is, in order to improve the durable life of the roller, the abrasion resistance of the rubber material should be improved so that the abrasive grain 100
It is sufficient to take measures to prevent a and 101a from disappearing, but it is impossible to improve the performance epoch-making as long as it depends on the physical properties of the rubber material, and it remains a long-term problem. Is. From this, it can be said that the retard separation method has high reliability of sheet separation but short durability.

Therefore, the rollers need to be replaced in a relatively short period of time, which is inconvenient for a user who processes a large number of sheets, and also leads to an increase in operation and maintenance costs for maintaining quality. Further, rubber has an extremely low frictional force due to poor vulcanization, deterioration of ultraviolet rays, ozone, etc., so that there is a problem that it is very difficult to control production and quality of the rubber.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a sheet conveying apparatus and an image processing apparatus in which the durability of a sheet acting member such as a roller is remarkably improved and maintenance is easy. It is a thing.

[0012]

A typical structure according to the present invention for achieving the above object is a sheet acting member for contacting a sheet, conveying the sheet by frictional force, or separating the sheet. , An elastically deformable second projection standing up on the working surface of the sheet and having a plurality of elastically deformable first projections adjacent to each other, and standing up at the joined tip of at least two or more first projections It is characterized by having.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a sheet conveying apparatus and an image processing apparatus according to the present invention will be described with reference to FIGS. 1 is an explanatory view of the feeding roller of the sheet conveying device, FIG. 2 is a detailed explanatory view of the surface of the feeding roller at the time of conveying the sheet, and FIG. 3 is a detailed explanatory view of the surface shape of the feeding roller in a state where durability is advanced. 4 is a detailed explanatory view of the feeding roller and the separation roller, FIG. 5 is an explanatory diagram of the overall configuration of the image processing apparatus, FIG. 6 is an explanatory view of the sheet conveying device, and FIG. 7 is an explanatory view of the feeding roller and the separation roller. .

[Overall Configuration] The image processing apparatus shown in FIG. 5 is an image forming apparatus adopting an electrophotographic system, and has an image forming apparatus 1 in the upper part of the apparatus body and a sheet conveying device 2 in the lower part.
have.

As shown in FIG. 5, the sheet conveying device 2 has a sheet storage cassette 3 on which the sheets S are stacked. Inside the sheet storage cassette 3, an intermediate plate 4 for directly mounting the sheets S, It has a spring 5 for supporting the plate 4. The intermediate plate 4 is biased by a spring 5 to press the stacked sheets against the pickup roller 7. A separation claw 6 is provided at the front end of the sheet storage cassette 3 and contacts the front end of the sheet S to restrict the rotation of the intermediate plate 4 and has a sheet separation function.

When an image forming signal is output from a controller unit (not shown), the pickup roller 7 rotates and the sheet S positioned at the top is sent out. Almost at the same time, the feeding roller 8 rotates in the sheet conveying direction, and the driving force in the opposite direction is transmitted to the separating roller 9 paired with the feeding roller 8 via the torque limiter. The separating roller 9 is supported by a rotatable arm 18 (see FIG. 6), and is biased by the spring 17 against the feeding roller 8 so that it can be pressed into contact therewith. Due to the action of the torque limiter, the separation roller 9 rotates the feed roller 8 (in the direction of arrow A) when there is no sheet or only one sheet.
Following this, the sheet is rotated in the conveying direction (direction of arrow C), and when there are two or more sheets, it is reversed (direction of arrow B) and the double-fed sheet is pushed back to the feeding means to prevent so-called double feeding. .

The feeding roller 8 is driven by a fixed amount to feed the sheet S to the image forming apparatus 1, and the driving is stopped at least when the sheet S reaches the pair of conveying rollers 10. The image forming apparatus 1 conveys the sheet fed from the sheet conveying apparatus 2 to the registration roller pair 11 by the conveyance roller pair 10, stops the operation once to correct the skew, and then rotates the photosensitive drum 12a of the process cartridge 12. The sheets are conveyed in synchronization. The process cartridge 12 has a charging unit, a developing unit, and a cleaning unit (not shown) around the photoconductor drum 12a. After being uniformly charged by the charging unit, the optical cartridge 12b scans a light beam in accordance with image information to stop it. Forming a latent image,
The toner image formed by the developing unit is transferred to the sheet conveyed by the transfer unit 12c. The sheet S to which the toner image has been transferred is fixed by applying heat and pressure in the fixing means 13, and is discharged and stacked by the conveying roller pair 14 and the discharging roller pair 15 onto the discharging tray 16 in the upper part of the apparatus.

As shown in FIG. 7, the feeding roller 8 includes a frame 20.
Driven by a drive motor (not shown), the drive shaft 21 is connected to the drive shaft 21 and is rotated in the transport direction (arrow A direction). The separation roller 9 is a drive shaft that is rotatably supported by the arm 18 via the drive shaft 22 and the coupling 23.
Drive is transmitted via the torque limiter 25 via 24. As a result, the separating roller 9 is transmitted with the driving force in the direction opposite to the conveying direction (the direction of arrow B). The arm 18 is supported by the sheet storage cassette 3 in this embodiment.

Since the separating roller 9 has a conveying force in the direction opposite to the sheet conveying direction in the double feed preventing direction, the feeding roller 8 needs to generate a reliable gripping force for feeding the sheet. is there. Generally, the feeding roller 8 and the separating roller 9 are pressed at about 1.96 [N] to 4.9 [N], but if the pressing force is increased, the gripping force is increased, but the separating roller 9 is necessary for reverse conveyance. You also have to increase that torque. Therefore, the feeding roller 8 is required to have a high frictional force so that the feeding roller 8 can be reliably conveyed with the minimum necessary pressing force.

{Surface configuration of feeding roller and separating roller}
Next, the structure of the feeding roller 8 as a sheet acting member will be described with reference to FIG. Feeding roller 8 of this embodiment
As shown in the enlarged view of FIG. 1 (a), a plurality of elastically deformable protrusions adjacent to each other in the radial direction of the roller surface (thickness direction of the roller) are formed on the collar portion 8a by using the surface fine processing technique. It is formed by integrally winding a film which is a base material provided. As shown in FIG. 1 (b), the protrusion shape is a spherical shape-shaped portion 8c, 8e having a spherical shape at the tip of a cylindrical base portion 8b, 8d as an upright portion standing upright from a roller peripheral surface which is a sheet working surface. Are integrally formed,
The two protrusions are configured so that the spherical shaped portions 8c and 8e are connected to each other. This is the first tapered protrusion (first protrusion)
Has become.

1 from the connected spherical shape parts 8c and 8e.
The two cylindrical base portions 8f are arranged in the thickness direction of the roller surface, and the spherical shaped portion 8g is formed at the tip similarly to the first tapered protrusion, which becomes the second tapered protrusion (second protrusion). There is. The cylindrical base portion 8f of the second tapered projection, the cylindrical base portions 8b and 8d of the first tapered projection, the spherical shaped portion 8g of the second tapered projection and the spherical shaped portions 8c and 8e of the first tapered projection have the same size. Has been done.

The total height h of the first tapered protrusion and the second tapered protrusion is about 20 μm to 500 μm, and the first tapered protrusion and the second tapered protrusion have substantially the same height.

If it is less than 20 μm, the groove (valley) through which the paper powder escapes is small, so a layer of paper powder is formed early due to paper passing durability, and the frictional transfer force between the roller and the sheet material decreases, This is because slip jam occurs, and if it is higher than 500 μm, minute traces are left on the sheet material due to the pressing force of the roller, and unevenness occurs in the image.Therefore, the height of the minute protrusions 22 should be within the above range. desirable.

The pitch of the tips of the second tapered protrusions is as shown in FIG.
As shown in (c), they are arranged at approximately the same interval as about 1 × 1.

Similarly to the conveying roller 8, the separating roller 9 also uses a surface fine processing technique to wind a film which is a base material having a plurality of elastically deformable protrusions adjacent to each other in the thickness direction of the roller surface. Is formed.

When the sheet S is conveyed by the feeding roller 8 and the separating roller 9, as shown in FIG. 2, the elastically deformable first tapered protrusion and the second tapered protrusion are elastically deformed, so that a large conveying force is exerted. Occurs, and stable sheet conveyance becomes possible.

The life of the separation roller 9 is determined by the abrasion of the polishing grains provided on the outer peripheral surface and the clogging by the paper dust, as described in the conventional example. However, according to the present embodiment, as shown in FIG.
Since the second tapered projection is formed on the tapered projection, the groove (valley) through which the paper dust generated from the sheet S escapes is large, and the paper dust layer is formed between the sheet S and the feeding roller 8 or the separation roller 9. Is not formed.

Further, the projection shape is a cylindrical base portion 8
The cylindrical base portions 8b, 8 are attached to the tips of b, 8d, 8f.
Since the spherical-shaped portions 8c, 8e, and 8g larger than d and 8f are integrally formed, the paper powder is spherical-shaped portions 8c and 8g.
It is easy to escape to the bottom of e, 8g.

As shown in FIG. 2, it is possible to obtain a stable frictional conveying force without being affected by paper dust. However, with the recent increase in the speed of image forming apparatuses and the diversification of sheets, the sheet conveys a high durability. Equipment has come to be required. However, according to the present embodiment, as shown in FIG. 1B, since the second tapered protrusion is formed on the first tapered protrusion, even if the second tapered protrusion is worn due to durability, the second tapered protrusion is worn. When the first tapered projections, which are larger in number than the projections, contact and carry the sheet S, a predetermined frictional carrying force can be obtained. (FIGS. 3 (a) and (b)) In this case, the groove portion (valley portion) through which the paper dust generated from the sheet S escapes becomes smaller than when the second tapered protrusion is formed at the tip of the first tapered protrusion. However, since the number of grooves (valleys) is increased, a layer of paper dust is not formed between the sheet and the feeding roller 8 or the separation roller 9 and the sheet.

Further, the first tapered protrusions are formed integrally with spherical shaped portions 8c and 8e larger than the cylindrical shaped base portions 8b and 8d at the tips of the cylindrical shaped base portions 8b and 8d, similarly to the second tapered protrusions. Therefore, the paper powder easily escapes to the lower portions of the spherical shaped portions 8c and 8e.

Further, since the contact portion with the sheet has a spherical shape, the contact area with the sheet is constant, and there is an effect that stable transportability can be maintained.

Further, since the projection is composed of the cylindrical base portion and the spherical spherical portion, it is not necessary to perform processing in consideration of the directionality with respect to the sheet conveying direction, and the surface fine processing property of the conveying roller is excellent. There is.

Further, since the first tapered protrusions are provided at substantially the same intervals, a uniform sheet conveying force is given to the entire roller surface.

Further, the driving force is applied to the separating roller 9 in the direction opposite to the conveying direction via the load system such as the torque limiter 25, so that the feeding roller 8 has a reliable grip for feeding the sheet. It is necessary to generate force. If the pressing force of the feeding roller 8 and the separation roller 9 is increased, the grip force is increased, but the torque required for the separation roller 9 to carry out reverse rotation must be increased accordingly. Then, the load on the roller drive increases, and the output of a drive motor (not shown) must be increased, resulting in an increase in cost.

According to the present embodiment, the feeding roller 8 and the separating roller 9 are made of a base material having a plurality of elastically deformable protrusions that are adjacent to each other in the thickness direction of the roller surface by using the surface micromachining technique. By forming a film by winding it, even if the pressing force between the feeding roller 8 and the separating roller 9 is set to be small, when the sheet S is conveyed, stable friction is achieved by the first tapered protrusion and the second tapered protrusion. When the sheet S can be conveyed and the sheet S is not conveyed, as shown in FIG. 4 (the portions 9b to 9g of FIG. 4A correspond to the portions 8b to 8g of the feeding roller 8), the sheet is fed. Sending roller 8
By coupling the first tapered protrusion and the second tapered protrusion of the separation roller 9 together like a fastener, the frictional force between the rollers using the conventional rubber material becomes larger, so that the output of the drive motor is reduced. It is possible to reduce the cost.

Furthermore, since this can be achieved only by replacing the feeding roller 8 and the separation roller 9 which are easily attached to and detached from the conventional sheet feeding apparatus, not only the apparatus having the new structure but also the existing market products It is easy to individually respond to
It is extremely versatile. Therefore, it is possible to provide a sheet feeding apparatus capable of promptly responding even to a user who uses a variety of sheets beyond expectations.

The separation roller 9 according to the present embodiment described above is used.
Although the retard separation method using is explained, the same effect can be obtained by a so-called separation pad method using a separation piece. Further, by providing the above-described first tapered protrusion and second tapered protrusion on the sheet working surface of the separation pad as well, the separation pad is less likely to be affected by paper dust or the like, and the sheet separation performance is long-term. Can be maintained over.

Further, the feeding roller 8 or the separating roller 9
Even if only one of the above is provided with the above-mentioned protrusion, the paper dust is less likely to adhere, and therefore the effect of improving the durability can be obtained.

Further, in the above-described embodiment, the image forming apparatus which conveys the sheet and records the image on the sheet is exemplified as the image processing apparatus, but the sheet conveying apparatus 2 having the feeding roller 8 and the separating roller 9 described above is used. It can also be suitably used in an image reading apparatus that separates and conveys a document and reads the document by the image reading means.

[0040]

As described above, according to the present invention, since the projections having the predetermined structure are provided on the sheet working surface, the sheet working member is less affected by the paper dust and the like than the sheet working members such as the conventional rollers, and is suitable for the sheet conveying and the like. It becomes possible to have high durability.
Therefore, it becomes possible to configure a maintenance-free sheet conveying device or an image processing device by using the sheet acting member according to the present invention as a roller member or the like.

Further, even if the pressing force between the feeding roller and the separating roller is set to be small, the sheet can be reliably separated and conveyed. Further, when the sheet is not conveyed, the projections of the respective rollers are fasteners. By coupling as described above, the output of the drive motor of the main body can be reduced, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a feeding roller of a sheet conveying device.

FIG. 2 is a detailed view of the surface of a feeding roller during sheet conveyance.

FIG. 3 is a detailed surface shape diagram of a feeding roller in a state where durability is advanced.

FIG. 4 is a detailed explanatory view of the surfaces of a feeding roller and a separating roller.

FIG. 5 is an overall configuration diagram of an image processing apparatus.

FIG. 6 is a diagram illustrating a sheet conveying device.

FIG. 7 is a diagram illustrating a feeding roller and a separation roller.

FIG. 8 is a diagram illustrating a conventional feeding roller and separation roller.

FIG. 9 is an explanatory diagram of a conventional polishing roller.

[Explanation of symbols]

S ... sheet 1 ... Image forming apparatus 2 ... Sheet conveying device 3 ... Sheet storage cassette 4 ... Middle plate 5 ... Spring 6 ... Separation claw 7 ... Pickup roller 8 ... Feeding roller 8a ... Color part 8b ... Cylindrical base 8c ... Spherical shape part 8d ... Cylindrical base 8e ... Sphere shape part 8f ... Cylindrical base 8g ... Sphere shape part 9 ... Separation roller 9b ... Cylindrical base 9c ... Spherical shape part 9d ... Cylindrical base 9e ... Sphere shape part 9f ... Cylindrical base 9g ... Sphere shape part 10… Conveyor roller pair 11 ... Registration roller pair 12… Process cartridge 12a ... Photosensitive drum 12b ... Optical means 12c ... Transfer means 13… Fixing means 14… Conveyor roller pair 15… Ejection roller pair 16… Ejection tray 17… Spring 18 ... arm 20 ... frame 21… Drive shaft 22 ... Drive shaft 23… Coupling 24 ... Drive shaft 25… Torque limiter

Claims (7)

[Claims] 1. A sheet acting member for coming into contact with a sheet, conveying the sheet by frictional force, or separating the sheet, wherein a plurality of elastically deformable first members standing on an action surface with the sheet and adjacent to each other. A sheet action member having a protrusion and an elastically deformable second protrusion standing upright at the tip of at least two or more of the first protrusions connected to each other. 2. The seat action member according to claim 1, wherein each of the first protrusion and the second protrusion has a spherical spherical portion at a tip of an upright standing portion. 3. The total height h of the first protrusion and the second protrusion is 20 μm to 500 μm, and the height of the first tapered protrusion is approximately h / 2. Alternatively, the seat action member according to claim 2. 4. The seat action member according to claim 1, wherein the first protrusions are provided at substantially the same intervals. 5. The sheet acting member according to claim 1, wherein the sheet acting member is a roller member for rotating and applying a conveying force to the sheet. . 6. A feeding roller which is driven and rotated in a sheet feeding direction, and a separation roller which is provided so as to be in pressure contact with the feeding roller and transmits a rotational force in a direction opposite to the sheet feeding direction. A sheet conveying apparatus comprising: the roller member according to claim 5, wherein at least one of the feeding roller and the separating roller is formed of the roller member. 7. An image forming means for forming an image on a sheet or an image reading means for reading an image of a sheet original, wherein the sheet is separated and fed to the image forming means or the image reading means. An image processing apparatus having a sheet conveying device.