JP2001255712A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device, making the dirt of transfer material originated from a soil of guide means possible to be prevented by restraining soil of guide means, while decreasing the restriction of a layout space. SOLUTION: In this image forming device provided with transfer material transporting belt 42 for transporting transfer paper P that the image is transferred thereon, and guide means guiding the above transfer paper P to the subsequent processing stage by coming into contact with a surface opposite to the surface that the image on the transfer paper P is formed, after parting the transfer paper P from the transfer material transporting belt 42, the device is let to compose the guide means adopting the belt member 61 making the surface shift along the passing route of the transfer paper P, and moreover to provide cleaning means 68 for cleaning the belt member surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, a printer, and the like. More specifically, the present invention relates to a transfer material transport member for electrostatically attracting and transporting a transfer material, and a transfer material transport device. The present invention relates to an image forming apparatus having guide means for contacting a surface of an unfixed image of a transfer material opposite to a surface on which an unfixed image is formed after the transfer material is separated from the member and guiding the transfer material to a next process. .

[0002]

2. Description of the Related Art In an image forming apparatus using an electrostatic transfer system such as a copying machine, a printer, and a facsimile machine, a visible image formed on a photoreceptor is transferred via an intermediate transfer member or directly onto a transfer material. The image is formed after the image is transferred to the fixing device. In such an image forming apparatus, for example, a transfer material transporting belt as a transfer material transporting member for transporting the transfer material, and a back surface of the transfer material separated from the transfer material transporting belt, contacting the transfer material And a guide unit for guiding the toner to a fixing device in the next step.
As such a guide means, a planar guide member (hereinafter referred to as a guide plate) is generally used.

In such an image forming apparatus, when transferring the developed image on the photoreceptor to a transfer material, a charge having a polarity opposite to the charged polarity of the toner as the visible image forming particles is applied to the transfer material transport belt. Granted. The transfer material is electrostatically attracted to the transfer material transport belt by the relationship between the true charge and the polarization charge generated on the transfer material side. Then, the toner is conveyed by suction in accordance with the rotation of the transfer material conveying belt, separated from the transfer material conveying belt, and passed over the guide plate while being in contact with the guide plate and guided to the fixing device.

However, since the transfer material separated from the transfer material transport belt still retains electric charges,
When the transfer material comes into contact with the guide plate, a discharge is easily generated between the transfer material and the guide plate. With this discharge, toner for forming a visible image or toner on the transfer material scatters, There is a problem that it is contaminated. For example, FIG.
As shown in (a), when the toner T near both ends of the transfer material P (for example, A4 length) scatters and adheres to the guide plate 160, the size of the transfer material P that passes next (for example, , A4 side), the back surface of the transfer material P and the edge surface of the transfer material P are contaminated. Also, as shown in FIG. 7A, when the rear end of the transfer material P lands on the guide plate 160, the toner T near the rear end of the transfer material P scatters and adheres to the guide plate 160. Similarly, when the landing position of the next passing transfer material P on the guide plate 160 changes to the upstream side due to a change in the size of the transfer material, temperature and humidity, and the like, the back surface of the transfer material P and the Will contaminate the surface. In particular, when the toner T adheres to the edge of the transfer material P, as shown in FIG. 6B and FIG. The dirt on K becomes noticeable.

[0005] In recent years, from the viewpoint of effective utilization of resources, apparatuses for recycling toner have increased, and there has been a tendency for toner having high fluidity to be required. Was more likely to cause the toner scattering as described above.

Here, in order to prevent discharge between the transfer material and the guide plate, conventionally, an image provided with a charge removing means for removing the charge of the transfer material after the transfer material is separated from the transfer material transport belt. A forming apparatus has been proposed (for example, see
No. 333704). However, since the static elimination function varies depending on the static elimination performance of the static elimination means and the moving speed of the transfer material, the stable static elimination action cannot always be exerted on the transfer material, and it is difficult to completely prevent the discharge. there were.

Further, in order to minimize the toner adhering to the guide plate from adhering to the transfer material, conventionally, a large number of ribs are formed on the surface of the guide plate as the above-mentioned guide plate, and the transfer material and the guide plate are connected to each other. Is known so as to minimize the contact area. However, when such a guide plate is used, the rib pitch is easily stained on the edge surface of the transfer material. Further, in the rib portion, stress is intensively applied to the transfer material, and the discharge is apt to concentrate. For example, toner dust on the streaks is easily generated on the visible image forming surface of the transfer material.

[0008]

In order to prevent the toner adhered to the guide plate by the discharge from adhering to the next transfer material, a cleaning means for cleaning the guide plate may be provided. Can be As such a cleaning means, for example, one configured to clean the guide plate by moving a cleaning member made of felt, sponge, or the like in a predetermined direction while being in contact with the guide plate. Conceivable. Specifically, for example, a cleaning member is engaged with a feed screw, which is conventionally used as a cleaning means for a corona discharger wire or the like, and the cleaning member is rotated to a predetermined direction by rotating the feed screw forward and backward. A configuration of reciprocating in the direction is conceivable.

When the above-described cleaning means is provided, it is necessary to secure a space on the guide plate for the cleaning member to reciprocate. However, since the passage path of the transfer material is formed on the guide plate and the space is limited, it is difficult to secure a layout space for the cleaning unit including a space for reciprocating the cleaning member. There is a problem. It should be noted that the present invention is not limited to the case where the cleaning means using the feed screw is used, and in the case where the cleaning means for the guide plate is provided, it is difficult to secure a layout space for the cleaning means. This is because, in the cleaning means for the guide plate, a moving mechanism for moving the cleaning member in a predetermined direction with the cleaning member in contact with the guide plate, or a transfer member on the guide plate for moving the cleaning member during passage of the transfer material. This is because it is necessary to provide a contact / separation mechanism for keeping the distance from the passage route, and the configuration becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and an object of the present invention is to prevent the guide means from being contaminated while reducing the restriction on the layout space, and to prevent the guide means from being contaminated. An object of the present invention is to provide an image forming apparatus capable of preventing transfer material from being contaminated.

[0011]

In order to achieve the above object, the present invention is directed to a transfer material conveying member for conveying a transfer material on which an image has been transferred, and a transfer material separated from the transfer material conveying member. After that, in the image forming apparatus having a guide unit that guides the transfer material to the next step by contacting the surface of the transfer material opposite to the image formed surface, the guide unit,
It is characterized by using a belt member movable on the surface along the passage of the transfer material, and providing a cleaning means for cleaning the surface of the belt member.

In the image forming apparatus according to the first aspect, the surface of the belt member constituting the guide means is cleaned by cleaning the surface of the belt member by the cleaning means. Accordingly, even if toner adheres to the belt member due to discharge between the transfer material and the belt member, the toner can be removed from the surface of the belt member, so that contamination of the transfer material can be prevented. Since the transfer member is configured such that the transfer member can move on the surface of the belt member, it is not necessary to secure the cleaning member on the transfer member passage path, and the cleaning member has a relatively large space around the belt member. It should just be provided in. Further, by providing the cleaning unit other than on the transfer material passage, it is not necessary to provide a contact / separation mechanism for keeping the cleaning unit away from the transfer material passage while the transfer material passes. Further, since the surface of the belt member is cleaned as the surface moves, there is no need to provide a moving mechanism for moving the cleaning member side, unlike the case of cleaning the flat guide plate.
As a result, restrictions on the layout space can be reduced.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the surface moving direction of the belt member is the same as the surface moving direction of the transfer material when passing through the belt member. The belt member is rotated.

In the image forming apparatus according to the present invention, since the surface movement direction of the belt member is a direction for promoting the movement of the transfer material when passing through the belt member, the guide means is provided on a flat surface on which the surface cannot move. The transfer property of the transfer material can be enhanced as compared with the case where the guide plate is formed in a shape. In addition, since the cleaning operation of the guide means can be performed even during the passage of the transfer material, unlike the case of using a planar guide plate, only the cleaning operation of the guide means does not require much time.

Here, when the transfer material is separated from the transfer material transporting member, a peeling discharge may be generated between the two, and the peeling discharge may cause a visible image forming toner or a background stain on the transfer material. The toner may be scattered and adhere to the transfer material conveying member. When the toner adheres to the transfer material conveying member, the toner may be transferred to the belt member at a position where the transfer material conveying member and the belt member are in close proximity to each other.

According to a third aspect of the present invention, in the image forming apparatus of the first aspect, the surface moving direction of the belt member is such that the transfer direction of the transfer material when passing through the belt member other than during the passage of the transfer material. The belt member is rotated so as to be in a direction opposite to the surface moving direction.

In the image forming apparatus of the present invention, the belt member is driven to rotate in the reverse direction so that the surface of the belt member cleaned by the cleaning means does not approach the transfer material conveying member again, and is transferred. It is used as a material passage route. Therefore, the toner from the transfer material transporting member does not adhere to the surface of the belt member once cleaned, and the surface can always be brought into contact with the transfer material in a clean state.

The supporting member for supporting the belt member is a roller-shaped supporting member (hereinafter referred to as a supporting roller) which rotates in conjunction with the movement of the surface of the belt member.
It is conceivable to use. However, when such a supporting roller is used, it is necessary to provide a rotating shaft of the roller, a bearing for supporting the rotating shaft, and the like, which may lead to an increase in cost.

Therefore, the invention of claim 4 is based on claims 1 and 2
Alternatively, in the image forming apparatus according to the third aspect, as the support member for the belt member, a support member that slidably supports the belt member without moving its surface is used.

According to a fifth aspect of the present invention, in the image forming apparatus of the fourth aspect, the support is configured to support at least two or more portions of the belt member.

In the image forming apparatus according to the fourth or fifth aspect, the belt member is slidably supported by the support.
Accordingly, unlike the case where the support roller is used as the support member, a rotating shaft and a bearing are not required, so that the number of components can be reduced and the cost can be reduced as compared with the case where the support roller is used. Will be possible. In particular, in the image forming apparatus according to the fifth aspect, since two or more portions of the belt member are supported by the support, the number of components can be further reduced, and the cost can be further reduced.

Here, when the above-mentioned support is used, the belt member slides in a state where the surface of the support does not move, so that the distance between the belt member and the support depends on the surface movement condition of the belt member. The sliding friction may become too large. If the sliding friction is too large, mechanical stress is applied to the belt member, and the durability of the belt member may be deteriorated. The problem caused by the sliding friction is not limited to the case where the support is used, and the case where the support member such as the support roller which rotates in conjunction with the movement of the surface of the belt member is used. Depending on the relative speed with respect to the support member, it may occur similarly.

Therefore, the invention of claim 6 is based on claim 1,
In the image forming apparatus of any one of 2, 3, 4, and 5, the surface moving operation of the belt member is performed intermittently.

In the image forming apparatus according to the sixth aspect, by intermittently performing the surface movement operation of the belt member, the chance of sliding between the belt member and the support member is reduced, and the mechanical stress of the belt member is reduced. Reduce. In particular, if the invention is applied to the image forming apparatus of the fourth or fifth aspect using the above-mentioned support as the support member, it works more effectively for reducing the mechanical stress of the belt member.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electrophotographic image forming apparatus will be described below. FIG.
1 is a schematic configuration diagram of an image forming apparatus main body 1 according to the present embodiment as viewed from the front side. The illustrated image forming apparatus includes:
It has an electrophotographic copying function and a printer function, but can additionally have a facsimile function.

In FIG. 1, a scanner unit A as an image reading means includes a contact glass 2 on which a document (not shown) is placed, a light source 3 for illuminating the document, a first mirror 4, a second mirror 5, and a third mirror. 6 and a reading device 7. The reading device 7 includes an image sensor (not shown) formed of, for example, a CCD and an imaging lens (not shown).

A drum-shaped photosensitive member 14 as an image carrier is rotatably mounted. Around the exposure device 8, a charging device 15, a toner image for forming a toner image on the photosensitive member are provided. Developing device 16, photoreceptor cleaning device 33, static elimination device (static elimination lamp) 37 as forming means
And so on.

The exposure device 8 includes a laser light source (not shown) for generating a laser beam L, a rotating polygon mirror 9, a scanning imaging lens system 10 including an fθ lens, and the like, and reflecting mirrors 11 and 1.
2 and 13 and the like.

The developing device 16 includes a developer case 18 for storing the developer D, and a developing roller 17 rotatably supported inside the developer case.
The developer D is carried and transported on the outer peripheral surface of the developer D.
As a result, a toner image is formed on the photoconductor 14. Further, the developing device 16 includes a toner replenishing container 18A for storing the toner T.
When the toner concentration of the developer D in the developer case 18 decreases, the toner replenishing roller 19 rotates to remove the toner T in the toner replenishment container 18A from the developer D in the developer case 18. It is to be replenished inside. In the present embodiment, a powdery two-component developer having a toner and a carrier is used as the developer D, but a one-component developer not containing a carrier may be used.

The photoconductor cleaning device 33 includes a photoconductor cleaning blade 34 and a cleaning case 35.
And a toner discharge member 36 disposed at the bottom of the cleaning case. The photoconductor cleaning blade 34 is made of an elastic material such as rubber, and has a base end fixed to the cleaning case 35. The tip of the photoconductor blade 34 extends in parallel with the longitudinal direction of the photoconductor 14, and the length of the tip in the longitudinal direction of the photoconductor 14 is equal to the length of the image area in the longitudinal direction of the photoconductor 14. The length is such that the entirety, that is, the entire area to which the transfer residual toner adheres can be cleaned. The edge of the tip of the photoconductor cleaning blade 34 is
By pressing against the surface, the transfer residual toner attached to the surface is scraped off.

The photosensitive member 14 is provided below the photosensitive member 14.
A transfer device 40 for transferring the toner image formed on the transfer material is provided. FIG. 2 shows a schematic configuration diagram around the transfer device 40 and an endless belt unit 60 described later. In FIG. 2, the transfer device 40 includes a transfer belt 42 as a transfer material transport member that electrostatically attracts and transports a transfer paper P as a transfer material. A transfer belt 42 made of a material having an intermediate resistance is electrically driven by a driving roller 43.
And the driven roller 44 so as to be rotatable, and driven in the direction of the arrow in the figure. Further, the transfer belt 42
At the surface of the photoreceptor 14. Around the transfer belt 42, a transfer bias roller 45 for applying a transfer bias to the transfer belt 42, and a belt cleaning blade 51 as cleaning means for cleaning toner adhered to the surface of the transfer belt 42 are provided. Belt cleaning blade 5 in this embodiment
Reference numeral 1 is provided in the counter direction with respect to the moving direction of the transfer belt 42. The cleaning blade 51 removes background toner and the like transferred from the surface of the photoreceptor 14 to the surface of the transfer belt 42, thereby preventing the back surface of the transfer paper P from being contaminated. The toner scraped off by the cleaning blade 51 is discharged by the toner discharge screw 59.

The transfer bias roller 45 is connected to a high-voltage power supply 100 for applying a transfer bias having a polarity opposite to the charging polarity of the toner to the transfer belt 42. Part of the output current a of the high-voltage power supply 100 flows into the driving roller 43 and the driven roller 44 and is returned to the high-voltage power supply 100 as feedback currents b and c. The applied bias is controlled so as to obtain the following relationship represented by Equation 1 so that d becomes a predetermined constant current.

## EQU1 ## a- (b + c) = d

On the left side of the transfer device 40 in the figure, after the transfer paper P is separated from the transfer belt 42,
A belt unit 60 is provided as guide means for guiding the transfer paper P to the fixing device 70 in the next step in contact with the surface of the transfer paper P opposite to the surface on which the unfixed toner image is formed. The belt unit 60 will be described later in detail.

On the other hand, the transfer paper P is fed from the paper feed cassettes 20, 20A, 20B below the main body 1 of the image forming apparatus, and is stopped once by abutting its leading end against the nip portion of the registration roller pair 21. , The photoconductor 14 and the transfer belt 42 at a timing
Is transferred to the transfer position S between

In the above arrangement, when an original is placed on the contact glass 2 and an image reading operation is started,
A first carriage (not shown) on which the light source 3 and the first mirror 4 are mounted moves parallel to the contact glass 2 at a constant speed by a stepping motor (not shown). Also,
A second carriage (not shown) on which the second mirror 5 and the third mirror 6 are mounted moves following the movement of the first carriage at half the speed of the first carriage. Then, the document is illuminated by the light source 3 and the reflected light is
The mirror 4, the second mirror 5, and the third mirror 6 guide the light to the image forming lens, and the image forming lens forms an original image on the CCD. The original image formed on the CCD is optically modulated by the reading device 7 to become an electric signal corresponding to the original image, and sent to the exposure device 8.

On the other hand, the surface of the photoreceptor 14 is uniformly charged by the charging device 15, and the exposure device 8
Is exposed by the laser light L from the laser light source. The laser light L is reflected by the rotary polygon mirror 9 and is irradiated on the surface of the photosensitive drum 21 via the scanning image forming lens system 10 and the reflecting mirrors 11, 12, and 13. This laser light L
Accordingly, an electrostatic latent image corresponding to the document image is formed on the surface of the photoconductor 14. This electrostatic latent image is visualized as a toner image by the developing device 16. Then, the transfer paper P sent out by the registration roller pair 21 passes through a transfer position S, which is a contact portion between the transfer belt 42 and the photoconductor 14, while being carried and conveyed by the transfer belt 42. At this time, the toner image on the photoconductor 14 is electrostatically transferred onto the transfer paper P by the transfer bias roller 45 to which the transfer bias is applied.

The transfer paper P on which the toner image has been transferred
Is successively suction-conveyed to the transfer belt 42 and is separated from the transfer conveyance belt 42 by the curvature of the drive roller 43 by a curvature.
Is passed over the endless belt 61 while contacting the belt 61, and is guided to the fixing device 70 via the fixing guide 70a. The transfer paper P on which the toner image has been fixed by the action of heat and pressure of the fixing roller pairs 71 and 72 of the fixing device 70 is sequentially discharged onto a discharge tray 90 by a discharge roller pair 80.

On the other hand, after the transfer of the toner image, the toner remaining on the surface of the photoconductor 14 is removed and cleaned by the photoconductor cleaning device 33. Further, the surface of the photoreceptor 14 after cleaning is neutralized by the neutralization device 37 to be initialized and used for the next image formation. After the transfer paper P is separated, the toner adhered on the transfer belt 42 is scraped off by the belt cleaning blade 51.

Next, the peripheral mechanism of the belt unit 60 as the guide means, which is a characteristic part of the present embodiment, will be described with reference to FIG. As shown in FIG. 2, the belt unit 60 includes an endless belt 61 that is a belt member configured to be able to move on the surface along a passage path of the transfer paper P;
A cleaning member 68 made of a sponge material is provided as cleaning means for cleaning the surface of the endless belt 61. The endless belt 61 according to the present embodiment is made of a polyester film. The endless belt 61 is supported by the drive roller 62 and the support rollers 63 and 64, and is configured so that the surface thereof can move endlessly in the direction of arrow e at the same linear speed as the linear speed of the transfer / transport belt 42. I have.

Here, when the above-mentioned conventional guide plate having a planar shape is used as the guide means, the layout space of the cleaning means including the space for cleaning is transferred to the transfer space formed on the guide plate. It will be difficult to secure them on the paper passage path. On the other hand, in the present embodiment, since the endless belt 61 whose surface moves endlessly is used, the cleaning unit can be provided at a location around the endless belt 61 where there is a relatively large space. In the illustrated example, the endless belt 61 is used.
The cleaning member 68 is provided on the downstream side in the surface movement direction of the endless belt 61 from a position where the transfer paper P and the transfer paper P are separated from each other.

As shown in FIG. 2, a thin film sealing member 69 is provided between the endless belt 61 and the transfer / conveying belt 42. This sealing member 69
At the position where the endless belt 61 and the transfer material conveyance belt 42 are in close proximity to each other, the toner attached to the transfer conveyance belt 42 is prevented from transferring to the endless belt 61 side. Here, as the toner adhering to the transfer / transport belt 42, there is a toner or the like scattered from the transfer paper P due to peeling discharge when the transfer sheet P is separated from the transfer / transport belt 42.

In the above configuration, when the endless belt 61 is driven to rotate, the belt surface is cleaned by the cleaning member 68 as the belt surface moves. Thus, even if toner adheres to the surface of the endless belt 61 due to the discharge between the transfer paper P and the endless belt 61, the toner can be removed, so that the toner does not accumulate on the surface of the endless belt 61. Therefore, it is possible to prevent the back surface and the edge surface of the transfer paper P passing next from being contaminated.

Further, in the present embodiment, as described above, it is not necessary to secure a layout space for the cleaning means including a space for cleaning on the transfer paper passage path, and it is possible to freely select an arrangement location. The degree improves. Further, by providing the cleaning member 68 at a position other than the transfer paper passage path, the transfer paper P can be passed while the cleaning member 68 is kept in contact with the endless belt 61. 68
There is no need to provide a contact / separation mechanism for keeping the distance.
Further, since the surface of the endless belt 61 is cleaned as the surface moves, there is no need to provide a moving mechanism for moving the cleaning member 68 side unlike the case of cleaning a flat guide plate. As a result, restrictions on the layout space are reduced.

As described above, according to the present embodiment, it is possible to prevent the guide unit from being contaminated while preventing the layout space from being restricted, thereby preventing the transfer paper P from being contaminated by the guide unit. Further, the endless belt 61 is rotated so that the surface movement direction of the endless belt 61 is in the direction of arrow e, that is, the direction that promotes the movement of the transfer paper P when passing through the endless belt 61. The transferability of the transfer paper P can be improved as compared with the case where a planar guide plate whose surface cannot be moved is used. In addition, by rotating the endless belt 61 in the direction of arrow e in this way, the cleaning operation of the endless belt 61 can be performed even during the passage of the transfer paper P. No time is required only for the cleaning operation of the guide means.

In the present embodiment, instead of providing the seal member 69 (see FIG. 2), the surface movement direction of the endless belt 61 is changed to the surface movement direction of the transfer paper P when passing through the endless belt 61. The endless belt 61 may be configured to rotate in the opposite direction, that is, in the direction indicated by the arrow f in FIG. In this case, the rotation driving operation of the endless belt 61 is performed except during the passage of the transfer paper P. According to this, the surface of the endless belt 61 cleaned by the cleaning member 68 is used as a passage path of the transfer paper P without approaching the transfer conveyance belt 42 again. Accordingly, the toner from the transfer conveyance belt 42 does not adhere to the surface of the endless belt 61 that has been once cleaned, and the transfer paper P can be contacted with the surface always being clean.

Next, a more specific configuration example of the image forming apparatus according to the present embodiment will be described. FIG. 3 is a perspective view illustrating a schematic configuration around the transfer device 40 and the belt unit 60 of the image forming apparatus according to the present embodiment. As illustrated, in the present embodiment, the transfer device 40 and the belt unit 60 including the endless belt 61 are housed in the same support case 47.

The driving roller 43, the driven roller 44, and the bias roller 45 of the transfer belt 42 (see FIG. 2)
Are supported by a belt frame 46 shown in FIG.
Fitting portions 46a and 46b provided on the belt frame 46 and fitting recesses 47a formed on the support case 47
And 47b, a part of the transfer device 40 including the transfer belt 42 is set in the support case 47.

As shown in FIG. 3, the transfer belt 42 obtains a rotational driving force from a high-voltage power supply 100 provided in a support case 47. Specifically, a drive gear 130 is attached to the rotation shaft of the drive roller 43 of the transfer belt 42, and the drive gear 130 is transmitted to the drive gear 130 from a motor (not shown) as a drive unit provided on the image forming apparatus main body side. The transfer belt 42 is rotationally driven by the driving force. Also, the high-voltage power supply 100 provided in the support case 47 is provided.
The transfer bias is applied to the bias roller 45 by connecting the electric wire 101 extending from the power supply 101 to the bias terminal 111 provided on the belt frame 46 so that the bias terminal 111 contacts the shaft end of the bias roller 45. Is done. Also, an electric wire 102 extending from the high-voltage power supply 100
And a bias terminal 11 provided on the belt frame 46.
2 and the bias terminal 112 and the driving roller 43 are connected.
As described above, a part of the output current a of the high-voltage power supply 100 is returned to the high-voltage power supply 100 as a return current via the drive roller 43 and the driven roller 44 by the contact between the shaft end of the driven roller and the shaft end of the driven roller. . Also, the transfer belt 42
Is a solenoid 120 provided in the support case 47,
The pressure mechanism 121 and the pressure receiving portion 117 provided on the belt frame 46 make contact with the photoconductor 14 as necessary. Further, the rotation shaft of the toner discharge screw 59 shown in FIG.
3 is mounted, and is driven to rotate via an idler gear 132 as the gear 131 mounted on the drive roller 43 is driven to rotate.

On the other hand, the driving roller 62 of the endless belt 61,
The support rollers 63 and 64 are provided with a bracket 65 shown in FIG.
a and 65b respectively. Then, fitting holes 6 formed in the brackets 65a and 65b are formed.
The endless belt unit 60 is set in the support case 47 by fitting the 6a and the fitting hole 66b with the fitting protrusions 48a and 48b provided in the support case 47.

As shown in FIG. 3, the endless belt 61 is a small motor 200 attached to the support case 47.
From the rotational driving force. Specifically, the endless belt 6
A drive gear 141 is attached to the rotation shaft of one drive roller 62, and the endless belt 61 is rotationally driven by the driving force transmitted from the small motor 200 to the drive gear 141 via the gears 142 and 143.

In place of the support rollers 63 and 64 as support members for the endless belt 61, a support member for slidably supporting the endless belt 61 in a state where the surface of the support member does not move is shown in FIG. Support frame 1 as shown
60 may be used. As the support frame 160, a frame made of a resin material having good slidability can be used. In the modification shown in FIG. 4, the support frame 160 supports two or more locations on the inner peripheral surface of the endless belt 61. The support frame 160 is fixed to the support case 47 so that the surface thereof does not move in conjunction with the rotation of the endless belt 61. According to such a configuration, as a support member of the endless belt 61,
Unlike the case where the support rollers 63 and 64 are used,
Since the rotating shaft and the bearing of the roller are not required, the number of components can be reduced, and the cost can be reduced.

In the modification shown in FIG. 4, the use of the support frame 160 allows the support frame 1 to be used.
The curvature of the endless belt 61 at the support portion 60 can be made smaller than in the case where the support rollers 63 and 64 are used. Thereby, the arrangement interval between the endless belt 61 and the transfer belt 42, and the endless belt 61 and the fixing guide 70
a The interval between the transfer belt 42 and the transfer belt 42 can be further reduced. Therefore, the transfer paper P can be guided more stably.

Further, in the modification shown in FIG. 4, the use of the support frame 160 is advantageous for the layout space of the charge removing member 300 as the charge removing means for the transfer sheet P. That is, in the configuration of FIG. 2 using the support roller 63, the curvature of the support roller 63 is large, and the transfer paper P
However, it is difficult to dispose a static eliminator near the support roller 63 because the position of the static electricity elimination member varies from the endless belt 61. On the other hand, by using the support frame 160, the curvature of the endless belt 61 can be reduced, so that the separation position of the transfer paper P can be stabilized. Therefore, the charge removing member 300 can be arranged. In the configuration of FIG. 2, a roller having a small curvature, that is, a roller having a small diameter may be used as the support roller 63, but it is not preferable because the rigidity of the roller may be insufficient.

Here, when the endless belt 61 is supported by the support frame 160, the surface of the support frame 160 does not move in conjunction with the rotation of the belt as described above. The sliding friction between the support frame 160 and the belt 61 may be too large. If the sliding friction becomes too large, unnecessary mechanical stress is applied to the endless belt 61, and the durability of the belt may be deteriorated.
Therefore, it is desirable to reduce the mechanical stress of the endless belt 61 as much as possible.

As a method for reducing the mechanical stress of the endless belt 61, for example, a method of controlling the surface moving operation of the endless belt 61, that is, a method of controlling the endless belt 61 to rotate intermittently is adopted. be able to. Such a method involves turning on / off the small motor 200.
This can be handled by controlling OFF. According to this, the chance of sliding between the support frame 160 and the endless belt 61 can be reduced, so that the mechanical stress of the belt 61 can be reduced. Therefore, the durability of the endless belt 61 can be improved.

When the rotation driving operation of the endless belt 61 is performed intermittently, a small motor 20 as shown in FIG.
Instead of a drive mechanism using 0 or a gear train, a simplified drive mechanism can be used. For example, as shown in FIG. 5, a lever 410 containing a one-way clutch 400,
Using a drive mechanism composed of a spring 420 and a solenoid 430, the solenoid 430 is turned on intermittently to transmit intermittent rotational driving force in the direction of arrow e to the drive roller 62 via the one-way clutch 400. . Thereby, the endless belt 61 can be intermittently rotated in the direction of arrow E. It should be noted that it is practically efficient to perform the rotation driving operation of the endless belt 61 at the end of the image forming operation or at the time of star operation. Even with such an operation interval, the ability to prevent the transfer paper P from contamination is sufficient. Be demonstrated. Further, when the rotation driving operation of the endless belt 61 is performed intermittently, and when the transfer paper P passes while the rotation of the endless belt 61 is stopped, it is expected that the transportability of the transfer paper P by the rotation of the endless belt 61 is promoted. Absent. However, since the transfer of the transfer sheet P by the guide means is not an absolute condition, there is no problem in the function of guiding the transfer sheet P to the next process even in intermittent rotation.

As a method for reducing the mechanical stress of the endless belt 61, for example, the surface moving speed of the endless belt 61 may be reduced.
Similarly, mechanical stress of the endless belt 61 can be reduced.

In the present invention, the toner adhered to the guide means due to the discharge between the transfer material and the guide means is cleaned, thereby preventing the transfer material from being contaminated. Therefore, in the configuration of the embodiment according to the present invention, the transfer material discharging means for suppressing the occurrence of the discharge, which is the cause of the transfer material contamination, as proposed in the above-mentioned Japanese Patent Application Laid-Open No. 5-333704 is provided. It is also possible to add.
According to this, it can be said that the contamination of the transfer material can be more reliably prevented.

[0059]

According to the first to sixth aspects of the present invention, the contamination of the guide means is prevented while the restriction of the layout space is reduced, and the contamination of the transfer material caused by the contamination of the guide means is prevented. There is an excellent effect that can be.

In particular, according to the invention of claim 2, since the movement of the transfer material can be promoted, there is an excellent effect that the transferability of the transfer material can be improved. Also,
Since the cleaning operation of the guide means can be performed during the passage of the transfer material, there is an excellent effect that the passage of the transfer material is not hindered.

In particular, according to the third aspect of the present invention, the toner from the transfer material transporting member does not adhere to the surface of the belt member once cleaned, and the surface of the belt member always comes into contact with the transfer material in a clean state. There is an excellent effect that it can be done.

In particular, according to the fourth and fifth aspects of the present invention, the number of components can be reduced as compared with the case where a supporting roller is used, so that there is an excellent effect that the cost can be reduced.

In particular, according to the invention of claim 5, since the number of components can be further reduced as compared with the structure of claim 5, there is an excellent effect that the cost can be further reduced.

In particular, according to the invention of claim 6, since the mechanical stress of the belt member can be reduced, there is an excellent effect that the durability of the belt member can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment.

FIG. 2 is a schematic configuration diagram around a transfer device and a belt unit.

FIG. 3 is a perspective view around a transfer device and a belt unit.

FIG. 4 is a schematic configuration diagram around a transfer device and a belt unit according to a modified example.

FIG. 5 is a schematic configuration diagram of a driving mechanism of a belt member.

FIGS. 6A and 6B are explanatory diagrams for explaining a defect of a conventional guide means.

FIGS. 7A and 7B are explanatory views for explaining another problem of the conventional guide means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Contact glass 3 Light source 4 First mirror 5 Second mirror 6 Third mirror 7 Reading device 8 Exposure device 14 Photoreceptor 15 Charging device 16 Developing device 17 Developing roller 18 Developer case 18A Toner supply container 19 Toner Supply roller 20 Paper feed cassette 21 Registration roller pair 33 Photoconductor cleaning device 34 Photoconductor cleaning blade 35 Cleaning case 36 Toner discharge member (for photoconductor) 37 Static eliminator (Static elimination lamp) 40 Transfer device 42 Transfer belt 43 Drive roller 44 Follower Roller 45 Transfer bias roller 47 Support case 51 Cleaning blade 59 Toner discharge screw 60 Belt unit (guide means) 61 Endless belt 62 Drive roller 63, 64 Support roller 69 Seal member 70 Fixing device 71a fixing guide 71, 72 a pair of fixing rollers 80 discharge rollers 90 discharge tray 100 high voltage power supply 200 miniature motor 300 discharging member 400 one-way clutch 410 lever 420 spring 430 Solenoid

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) 9A001 (72) Inventor Hiroshi Saito 1-3-6 Nakamagome, Ota-ku, Tokyo F-term (Ricoh Co., Ltd.) Reference) 2H027 ED16 ED24 ED27 EF12 2H032 BA18 BA30 2H034 AA02 2H072 CA07 CB07 CB08 HA03 JA03 3F101 AB01 AB09 9A001 BB06 HH34 JJ35 KK42

Claims (6)

[Claims] A transfer material transporting member for transporting a transfer material onto which an image has been transferred; and a surface opposite to the surface on which the image of the transfer material is formed after the transfer material is separated from the transfer material transport member. An image forming apparatus comprising: a guide member that contacts and guides the transfer material to a next process, wherein the guide member is configured by using a belt member that can move on a surface along a passage path of the transfer material, and the belt includes An image forming apparatus comprising a cleaning unit for cleaning a member surface. 2. The image forming apparatus according to claim 1, wherein the belt member is rotated such that the surface movement direction of the belt member is the same as the surface movement direction of the transfer material when passing through the belt member. An image forming apparatus comprising: 3. The image forming apparatus according to claim 1, wherein the surface movement direction of the belt member is opposite to the surface movement direction of the transfer material when passing through the belt member, other than during the passage of the transfer material. An image forming apparatus characterized by rotating the belt member. 4. The image forming apparatus according to claim 1, wherein a support for slidably supporting the belt member is used as a support member for the belt member without a surface thereof moving. Image forming apparatus. 5. The image forming apparatus according to claim 4, wherein said support member is configured to support at least two or more portions of said belt member. 6. The image forming apparatus according to claim 1, wherein the surface movement operation of the belt member is performed intermittently.